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Sample records for high aggression-disruption chad

  1. Double Jeopardy: Child and School Characteristics That Predict Aggressive-Disruptive Behavior in First Grade.

    Science.gov (United States)

    Thomas, Duane E; Bierman, Karen L; Thompson, Celine; Powers, C J

    2008-01-01

    High rates of aggressive-disruptive behavior exhibited by children during their initial years of elementary school increase their risk for significant behavioral adjustment problems with teachers and peers. The purpose of the present study was to examine the unique and combined contributions of child vulnerabilities and school context to the development of aggressive-disruptive student behavior during first grade. Parent ratings and child interviews assessed three child characteristics associated with risk for the development of aggressive behavior problems in elementary school (aggressive-disruptive behaviors at home, attention problems, and social cognitions) in a sample of 755 first-grade children in four demographically diverse American communities. Two school characteristics associated with student aggressive-disruptive behavior problems (low-quality classroom context, school poverty levels) were also assessed. Linear and multilevel analyses showed that both child and school characteristics made independent and cumulative contributions to the development of student aggressive-disruptive behavior at school. Although rates of student aggressive-disruptive behavior varied by gender and race, the predictive model generalized across all groups of children in the study.

  2. Double Jeopardy: Child and School Characteristics that Predict Aggressive-Disruptive Behavior in First Grade

    Science.gov (United States)

    Thomas, Duane E.; Bierman, Karen L.; Thompson, Celine; Powers, C. J.

    2008-01-01

    High rates of aggressive-disruptive behavior exhibited by children during their initial years of elementary school increase their risk for significant behavioral adjustment problems with teachers and peers. The purpose of the present study was to examine the unique and combined contributions of child vulnerabilities and school context to the…

  3. Youth Aggressive/Disruptive Behavior Trajectories and subsequent Gambling among Urban Male Youth

    Science.gov (United States)

    Martins, Silvia S.; Liu, Weiwei; Hedden, Sarra L.; Goldweber, Asha; Storr, Carla L.; Derevensky, Jeffrey L.; Stinchfield, Randy; Ialongo, Nicholas S.; Petras, Hanno

    2013-01-01

    Objective This study examines the association between aggressive/disruptive behavior development in two distinct developmental periods, childhood (i.e., grades 1–3) and early adolescence (i.e., grades 6–10) and subsequent gambling behavior in late adolescence up to age 20. Method The sample consists of 310 urban males of predominately minority and low socioeconomic status followed from first grade to late adolescence. Separate general growth mixture models (GGMM) were estimated to explore the heterogeneity in aggressive/disruptive behavior development in the above-mentioned two time periods. Results Three distinct behavior trajectories were identified for each time period: a chronic high, a moderate increasing and a low increasing class for childhood, and a chronic high, a moderate increasing followed by decreasing and a low stable class for early adolescence. There was no association between childhood behavior trajectories and gambling involvement. Males with a moderate behavior trajectory in adolescence where two times more likely to gamble compared to those in the low stable class (OR=1.89, 95% CI=1.11, 3.24). Those with chronic high trajectories during either childhood or early adolescence (OR=2.60, 95% CI=1.06, 6.38; OR=3.19, 95% CI=1.18, 8.64, respectively) were more likely to be at-risk/problem gamblers than those in the low class. Conclusions Aggressive/disruptive behavior development in childhood and early adolescence is associated with gambling and gambling problems in late adolescence among urban male youth. Preventing childhood and youth aggressive/disruptive behavior may be effective to prevent youth problem gambling. PMID:23410188

  4. Novel Dielectric Coagulometer Identifies Hypercoagulability in Patients with a High CHADS2 Score without Atrial Fibrillation.

    Directory of Open Access Journals (Sweden)

    Yuki Hasegawa

    Full Text Available Recent reports showed that the CHADS2 score predicted the risk of strokes in patients without atrial fibrillation (AF. Although the hypercoagulability may contribute to the thrombogenesis, it has not been fully investigated due to a lack of a sensitive evaluation modality. Recently a novel dielectric blood coagulometry (DBCM was invented for evaluating the coagulability by measuring the temporal change in whole blood dielectric permittivity.We evaluated the utility of the DBCM for identifying the coagulability.For fundamental experiments, 133 citrated blood samples were drawn from subjects with or without heparin administration. A DBCM analysis was performed to find the adequate coagulation index, and to delineate its measurement range by adding recombinant human tissue factor (TF or heparin. Then the coagulability was assessed by DBCM and conventional coagulation assays in 84 subjects without AF, who were divided into 3 groups by their CHADS2 score. Another 17 patients who received warfarin were also assessed by DBCM to evaluate the effect of anticoagulants.We calculated the derivative of the dielectric permittivity change after recalcification, and extracted the end of acceleration time (EAT as a novel index. The EAT showed a dose-dependent shortening with the addition of serial dilutions of TF (×10-2 to ×10-4, and a dose-dependent prolongation with the addition of heparin (0.05 to 0.15 U/ml. The EAT was significantly shorter in the higher CHADS2 score group (19.8 ± 4.8, 18.6 ± 3.1, and 16.3 ± 2.7 min in the CHADS2 = 0, 1, and ≥2 groups, respectively, p = 0.0065 by ANOVA. Patients receiving warfarin had a significantly more prolonged EAT than those without warfarin (18.6±4.2 vs. 25.8±7.3 min, p <0.001. DBCM detected the whole blood coagulability with a high sensitivity. Subjects with higher CHADS2 scores exhibited hypercoagulability without AF.

  5. The Multifaceted Impact of Peer Relations on Aggressive-Disruptive Behavior in Early Elementary School

    OpenAIRE

    Powers, Christopher J.; Bierman, Karen L.

    2012-01-01

    Following a large, diverse sample of 4096 children in 27 schools, this study evaluated the impact of three aspects of peer relations, measured concurrently, on subsequent child aggressive-disruptive behavior during early elementary school – peer-dislike, reciprocated friends' aggressiveness, and classroom levels of aggressive-disruptive behavior. Teachers rated child aggressive-disruptive behavior in first and third grade, and peer relations were assessed during second grade. Results indicate...

  6. The Multifaceted Impact of Peer Relations on Aggressive-Disruptive Behavior in Early Elementary School

    Science.gov (United States)

    Powers, Christopher J.; Bierman, Karen L.

    2013-01-01

    Following a large, diverse sample of 4,096 children in 27 schools, this study evaluated the impact of 3 aspects of peer relations, measured concurrently, on subsequent child aggressive-disruptive behavior during early elementary school: peer dislike, reciprocated friends' aggressiveness, and classroom levels of aggressive-disruptive behavior.…

  7. School outcomes of aggressive-disruptive children: prediction from kindergarten risk factors and impact of the fast track prevention program.

    Science.gov (United States)

    Bierman, Karen L; Coie, John; Dodge, Kenneth; Greenberg, Mark; Lochman, John; McMohan, Robert; Pinderhughes, Ellen

    2013-01-01

    A multi-gate screening process identified 891 children with aggressive-disruptive behavior problems at school entry. Fast Track provided a multi-component preventive intervention in the context of a randomized-controlled design. In addition to psychosocial support and skill training for parents and children, the intervention included intensive reading tutoring in first grade, behavioral management consultation with teachers, and the provision of homework support (as needed) through tenth grade. This study examined the impact of the intervention, as well as the impact of the child's initial aggressive-disruptive behaviors and associated school readiness skills (cognitive ability, reading readiness, attention problems) on academic progress and educational placements during elementary school (Grades 1-4) and during the secondary school years (Grades 7-10), as well as high school graduation. Child behavior problems and skills at school entry predicted school difficulties (low grades, grade retention, placement in a self-contained classroom, behavior disorder classification, and failure to graduate). Disappointingly, intervention did not significantly improve these long-term school outcomes.

  8. Consolidated Human Activities Database (CHAD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Consolidated Human Activity Database (CHAD) contains data obtained from human activity studies that were collected at city, state, and national levels. CHAD is...

  9. Microbial hitchhikers on intercontinental dust: catching a lift in Chad

    OpenAIRE

    Favet, Jocelyne; Lapanje, Ales; Giongo, Adriana; Kennedy, Suzanne; Aung, Yin-Yin; Cattaneo, Arlette; Davis-Richardson, Austin G; Christopher T. Brown; Kort, Renate; Brumsack, Hans-Jürgen; Schnetger, Bernhard; Chappell, Adrian; Kroijenga, Jaap; Beck, Andreas; Schwibbert, Karin

    2012-01-01

    Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Satellite remote sensing revealed major dust sources across the Sahara. Indeed, the Bodélé Depression in the Republic of Chad has been called the dustiest place on earth. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that t...

  10. The developmental impact of two first grade preventive interventions on aggressive/disruptive behavior in childhood and adolescence: an application of latent transition growth mixture modeling.

    Science.gov (United States)

    Petras, Hanno; Masyn, Katherine; Ialongo, Nick

    2011-09-01

    We examine the impact of two universal preventive interventions in first grade on the growth of aggressive/disruptive behavior in grades 1-3 and 6-12 through the application of a latent transition growth mixture model (LT-GMM). Both the classroom-centered and family-centered interventions were designed to reduce the risk for later conduct problems by enhancing the child behavior management practices of teachers and parents, respectively. We first modeled growth trajectories in each of the two time periods with separate GMMs. We then associated latent trajectory classes of aggressive/disruptive behavior across the two time periods using a transition model for the corresponding latent class variables. Subsequently, we tested whether the interventions had direct effects on trajectory class membership in grades 1-3 and 6-12. For males, both the classroom-centered and family-centered interventions had significant direct effects on trajectory class membership in grades 6-12, whereas only the classroom-centered intervention had a significant effect on class membership in grades 1-3. Significant direct effects for females were confined to grades 1-3 for the classroom-centered intervention. Further analyses revealed that both the classroom-centered and family-centered intervention males were significantly more likely than control males to transition from the high trajectory class in grades 1-3 to a low class in grades 6-12. Effects for females in classroom-centered interventions went in the hypothesized direction but did not reach significance. © Society for Prevention Research 2011

  11. The CHADS2 and CHA2DS2-VASc scores predict adverse vascular function, ischemic stroke and cardiovascular death in high-risk patients without atrial fibrillation: role of incorporating PR prolongation.

    Science.gov (United States)

    Chan, Yap-Hang; Yiu, Kai-Hang; Lau, Kui-Kai; Yiu, Yuen-Fung; Li, Sheung-Wai; Lam, Tai-Hing; Lau, Chu-Pak; Siu, Chung-Wah; Tse, Hung-Fat

    2014-12-01

    To investigate whether the CHADS2 and CHA2DS2-VASc scores have clinical utility for prediction of adverse vascular function and vascular dysfunction-mediated incident cardiovascular (CV) events among high-risk patients without atrial fibrillation (AF), and the additional value of incorporating PR prolongation to the scores. We analyzed 579 high-risk CV outpatients without clinical AF in a prospective cohort for new-onset ischemic stroke, myocardial infarction (MI), congestive heart failure (CHF), and CV death. Brachial flow-mediated dilation (FMD) and nitroglycerin-mediated dilatation (NMD), carotid intima-media thickness (IMT) and pulse wave velocity (PWV) were determined. Baseline CHADS2 score was associated with lower FMD (Pearson r = -0.16, P PR prolongation, the CHA2DS2-VASc-PR score achieved the highest C-Statistic for CV death prediction (0.70, P PR prolongation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Basic Chad Arabic: Comprehension Texts.

    Science.gov (United States)

    Absi, Samir Abu; Sinaud, Andre

    This text, principally designed for use in a three-volume course on Chad Arabic, complements the pre-speech and active phases of the course in that it provides the answers to comprehension exercises students are required to complete during the course. The comprehension exercises require that students listen to an instructor or tape and write…

  13. Application of CHAD hydrodynamics to shock-wave problems

    Energy Technology Data Exchange (ETDEWEB)

    Trease, H.E.; O`Rourke, P.J.; Sahota, M.S. [Los Alamos National Lab., NM (United States)

    1997-12-31

    CHAD is the latest in a sequence of continually evolving computer codes written to effectively utilize massively parallel computer architectures and the latest grid generators for unstructured meshes. Its applications range from automotive design issues such as in-cylinder and manifold flows of internal combustion engines, vehicle aerodynamics, underhood cooling and passenger compartment heating, ventilation, and air conditioning to shock hydrodynamics and materials modeling. CHAD solves the full unsteady Navier-Stoke equations with the k-epsilon turbulence model in three space dimensions. The code has four major features that distinguish it from the earlier KIVA code, also developed at Los Alamos. First, it is based on a node-centered, finite-volume method in which, like finite element methods, all fluid variables are located at computational nodes. The computational mesh efficiently and accurately handles all element shapes ranging from tetrahedra to hexahedra. Second, it is written in standard Fortran 90 and relies on automatic domain decomposition and a universal communication library written in standard C and MPI for unstructured grids to effectively exploit distributed-memory parallel architectures. Thus the code is fully portable to a variety of computing platforms such as uniprocessor workstations, symmetric multiprocessors, clusters of workstations, and massively parallel platforms. Third, CHAD utilizes a variable explicit/implicit upwind method for convection that improves computational efficiency in flows that have large velocity Courant number variations due to velocity of mesh size variations. Fourth, CHAD is designed to also simulate shock hydrodynamics involving multimaterial anisotropic behavior under high shear. The authors will discuss CHAD capabilities and show several sample calculations showing the strengths and weaknesses of CHAD.

  14. The Conspicuous Opening Date of CHAD

    Institute of Scientific and Technical Information of China (English)

    Guo Yan

    2010-01-01

    @@ "The Opening Date of Chad"-an event organized by the Chadian Embassy to China will be held In Beijing on the 28th and 29th of June.It will take up such forms as meeting for discussions and site touring ect.,with the purpose of facilitating the mutual undestanding between Chad and China as well as boosting the international exchanges between the two countries in the area of culture,economy and trade.

  15. Rapid Contraceptive Uptake and Changing Method Mix With High Use of Long-Acting Reversible Contraceptives in Crisis-Affected Populations in Chad and the Democratic Republic of the Congo.

    Science.gov (United States)

    Rattan, Jesse; Noznesky, Elizabeth; Curry, Dora Ward; Galavotti, Christine; Hwang, Shuyuan; Rodriguez, Mariela

    2016-08-11

    The global health community has recognized that expanding the contraceptive method mix is a programmatic imperative since (1) one-third of unintended pregnancies are due to method failure or discontinuation, and (2) the addition of a new method to the existing mix tends to increase total contraceptive use. Since July 2011, CARE has been implementing the Supporting Access to Family Planning and Post-Abortion Care (SAFPAC) initiative to increase the availability, quality, and use of contraception, with a particular focus on highly effective and long-acting reversible methods-intrauterine devices (IUDs) and implants-in crisis-affected settings in Chad and the Democratic Republic of the Congo (DRC). This initiative supports government health systems at primary and referral levels to provide a wide range of contraceptive services to people affected by conflict and/or displacement. Before the initiative, long-acting reversible methods were either unknown or unavailable in the intervention areas. However, as soon as trained providers were in place, we noted a dramatic and sustained increase in new users of all contraceptive methods, especially implants, with total new clients reaching 82,855, or 32% of the estimated number of women of reproductive age in the respective catchment areas in both countries, at the end of the fourth year. Demand for implants was very strong in the first 6 months after provider training. During this time, implants consistently accounted for more than 50% of the method mix, reaching as high as 89% in Chad and 74% in DRC. To ensure that all clients were getting the contraceptive method of their choice, we conducted a series of discussions and sought feedback from different stakeholders in order to modify program strategies. Key program modifications included more focused communication in mass media, community, and interpersonal channels about the benefits of IUDs while reinforcing the wide range of methods available and refresher training for

  16. Water resources of the Chad Basin Region

    Directory of Open Access Journals (Sweden)

    Franklyn R. Kaloko

    2013-07-01

    Full Text Available River basin development is seen as a very effective means of improving agricultural productivity. In the Chad Basin area of the Sahelian Zone of the West African Sub-Region, the water resources have been harnessed to ensure viable agricultural programmes for Nigeria. However,the resultant successes have met by many problems that range from physical to socio-economic and of which water losses have been the most threatening. The study has called for the use of Hexa.deconal (C1-OH film on the water surface of the Chad as a means of reducing evaporation.

  17. the Kuri cattle of Lake Chad Basin

    African Journals Online (AJOL)

    1997-06-18

    Jun 18, 1997 ... A close look at a rare African breed —— the Kuri cattle of Lake Chad ..... tropical around the Lake and semi-arid and tropical away ... milked once daily in the dry season (December—May) and ...... Forest (Nigeria), 11, 19.

  18. Area Handbook Series: Chad, A Country Study

    Science.gov (United States)

    1988-12-01

    Government, 1975-78 ......... 24 Civil War and Multilateral Mediation , 1979-82 ..... 27 Chapter 2. The S4ciety and Its Environment _ 33 Dennis D. Cordell...PPT with a new party, the National Movement for the Cultural and Social Revolution (Mouvement National pour la Revolution Culturelle et Sociale-MNRCS...Multilateral Mediation , 1979-82 From 1979 to 1982, Chad experienced unprecedented change and spiraling violence. Southerners finally lost control of what

  19. Microbial hitchhikers on intercontinental dust: catching a lift in Chad

    Science.gov (United States)

    Favet, Jocelyne; Lapanje, Ales; Giongo, Adriana; Kennedy, Suzanne; Aung, Yin-Yin; Cattaneo, Arlette; Davis-Richardson, Austin G; Brown, Christopher T; Kort, Renate; Brumsack, Hans-Jürgen; Schnetger, Bernhard; Chappell, Adrian; Kroijenga, Jaap; Beck, Andreas; Schwibbert, Karin; Mohamed, Ahmed H; Kirchner, Timothy; de Quadros, Patricia Dorr; Triplett, Eric W; Broughton, William J; Gorbushina, Anna A

    2013-01-01

    Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Satellite remote sensing revealed major dust sources across the Sahara. Indeed, the Bodélé Depression in the Republic of Chad has been called the dustiest place on earth. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that the samples contained a large variety of microbes well adapted to the harsh desert conditions. The most abundant bacterial groupings in four different phyla included: (a) Firmicutes—Bacillaceae, (b) Actinobacteria—Geodermatophilaceae, Nocardiodaceae and Solirubrobacteraceae, (c) Proteobacteria—Oxalobacteraceae, Rhizobiales and Sphingomonadaceae, and (d) Bacteroidetes—Cytophagaceae. Ascomycota was the overwhelmingly dominant fungal group followed by Basidiomycota and traces of Chytridiomycota, Microsporidia and Glomeromycota. Two freshwater algae (Trebouxiophyceae) were isolated. Most predominant taxa are widely distributed land inhabitants that are common in soil and on the surfaces of plants. Examples include Bradyrhizobium spp. that nodulate and fix nitrogen in Acacia species, the predominant trees of the Sahara as well as Herbaspirillum (Oxalobacteraceae), a group of chemoorganotrophic free-living soil inhabitants that fix nitrogen in association with Gramineae roots. Few pathogenic strains were found, suggesting that African dust is not a large threat to public health. PMID:23254516

  20. Human and animal vaccination delivery to remote nomadic families, Chad.

    Science.gov (United States)

    Schelling, Esther; Bechir, Mahamat; Ahmed, Mahamat Abdoulaye; Wyss, Kaspar; Randolph, Thomas F; Zinsstag, Jakob

    2007-03-01

    Vaccination services for people and livestock often fail to achieve sufficient coverages in Africa's remote rural settings because of financial, logistic, and service delivery constraints. In Chad from 2000 through 2005, we demonstrated the feasibility of combining vaccination programs for nomadic pastoralists and their livestock. Sharing of transport logistics and equipment between physicians and veterinarians reduced total costs. Joint delivery of human and animal health services is adapted to and highly valued by hard-to-reach pastoralists. In intervention zones, for the first time approximately 10% of nomadic children (> 1-11 months of age) were fully immunized annually and more children and women were vaccinated per day during joint vaccination rounds than during vaccination of persons only and not their livestock (130 vs. 100, p < 0.001). By optimizing use of limited logistical and human resources, public health and veterinary services both become more effective, especially at the district level.

  1. Chad Basin: Paleoenvironments of the Sahara since the Late Miocene

    Science.gov (United States)

    Schuster, Mathieu; Duringer, Philippe; Ghienne, Jean-François; Roquin, Claude; Sepulchre, Pierre; Moussa, Abderamane; Lebatard, Anne-Elisabeth; Mackaye, Hassan Taisso; Likius, Andossa; Vignaud, Patrick; Brunet, Michel

    2009-08-01

    Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly paleontological field investigations of the Miocene-Pliocene of the Chad Basin. This article synthesizes some of the results of the MPFT, with focus on the Chad Basin development during the Neogene. We propose an overview of the depositional paleoenvironments of this part of Africa at different scales of time and space, based on a multidisciplinary approach (sedimentary geology, geomorphology, geophysic, numerical simulations and geochronology). The Miocene-Pliocene paleoenvironments are examined through the sedimentary archives of the early hominids levels and the Holocene Lake Mega-Chad episode illustrates the last major paleoenvironmental change in this area. The sedimentary record of the Chad Basin since the Late Miocene can be schematized as the result of recurrent interactions from lake to desert environments.

  2. Hepatitis B among young people in Lere health department (Chad ...

    African Journals Online (AJOL)

    Hepatitis B among young people in Lere health department (Chad) ... South Sudan Medical Journal ... Agespecific prevalence varies by geographical region with highest endemicity levels in sub-Saharan Africa and prevalence below 2% in ...

  3. Conflict and the women of Chad.

    Science.gov (United States)

    Sy, A D

    1993-06-01

    Chad was used as an example of how women and children were the most affected during national and international conflicts. The conditions of women before and during the conflict were described. Chad has been a country involved in a war provoked by psychological differences between the way of life, economic activity, and culture of Arab Muslims who are nomadic pastoralists, and Animist and Christian farmers. The important year was 1979, when the country was torn apart by civil war. Women before the conflict were part of a patriarchal society of men heading households and sole producers for the family. One decision maker controlled family matters: the man. Men also possessed all household goods. Women were biological and social producers, and value was placed on having large numbers of children. Muslim women lived in seclusion. Married women, who engaged in commercial activity, were mocked and exposed their husbands to the humiliation of not being able to provide sufficiently for the family. Between 1979 and 1982, many men were exiled to other countries nearby, which sometimes meant the abandonment of women and children. The remaining men were limited in their ability to earn money, and reverted to fishing, farming, and hunting. Gender relations changed. Survival strategies were developed, such as women working as domestics or selling products. Petty trading and agricultural and market gardening enterprises were flourishing. Women learned skills in dressmaking, embroidery, or knitting. Sometimes long distances were traveled in order to secure income. Women set up their own banking system with a system of "tontines" or savings cooperatives. The war's impact was to disrupt social and private life, which allowed women to enter the public domain and contribute to economic security. The downside of the conflict was the toll in human life and poverty for vast numbers of women and children. The physical, financial, and psychological exhaustion helped to create an awareness

  4. Climate Change in Africa: Impacts and Effects on the Inhabitants of the Lake Chad Region.

    Science.gov (United States)

    Abubakar, B.; Tahir, S. M.; Olisa, O.

    2009-05-01

    The Department of Energy and Climate Change defined climate as the average weather experienced over a long period. This includes temperature, wind and rainfall patterns. The climate of the Earth is not static, and has changed many times in response to a variety of natural causes. Due to human activities in emmiting green house gases has resulted the Earth to get warmed by 0.74°C over the last hundred years. Around 0.4°C of this warming has occurred since the 1970s. Climate is now one of the major phenomenon threatening lives and humanity in general since the beginning of industrial revolution. Climate exerts a profound influence on the lives of poor populations in the Lake Chad region of Africa who depend on fishing and crop cultivation for livelihood and sustenance, who are unprotected against climate-related diseases, who lacked secure access to water and food and who are vulnerable to hydro meteorological hazard. The effects of climate change on the study area are many and include diminishing resources and conflicts over the available limited water resources. The Lake Chad region is a fragile area with high climate variability and extremes of weather. As this inland water is used for domestic and agricultural purposes, salt mining, as well as transportation by Nigerians, Nigeriens, Chadian and Cameroonians, it is an area of trans-boundary water conflicts. This paper examines the part played by climate change in the decline of fishery resources and livelihood activities in the Lake Chad region. Data from field studies, structured interview and secondary sources show that fish catches and livelihood activities have declined tremendously in recent times due to several factors including overexploitation and increasing demands on the aquatic resources. Findings from the study show that droughty periods have resulted in the reduction of open lake water surface from about 25,000 km2 in 1973 to less than 2,000 km2 in the 1990s. This has led to the diminishing aquatic

  5. Predictive value of CHADS2 and CHA2DS2-VASc scores for acute myocardial infarction in patients with atrial fibrillation.

    Science.gov (United States)

    Pang, Hui; Han, Bing; Fu, Qiang; Zong, Zhenkun

    2017-07-05

    The presence of acute myocardial infarction (AMI) confers a poor prognosis in atrial fibrillation (AF), associated with increased mortality dramatically. This study aimed to evaluate the predictive value of CHADS2 and CHA2DS2-VASc scores for AMI in patients with AF. This retrospective study enrolled 5140 consecutive nonvalvular AF patients, 300 patients with AMI and 4840 patients without AMI. We identified the optimal cut-off values of the CHADS2 and CHA2DS2-VASc scores each based on receiver operating characteristic curves to predict the risk of AMI. Both CHADS2 score and CHA2DS2-VASc score were associated with an increased odds ratio of the prevalence of AMI in patients with AF, after adjustment for hyperlipidaemia, hyperuricemia, hyperthyroidism, hypothyroidism and obstructive sleep apnea. The present results showed that the area under the curve (AUC) for CHADS2 score was 0.787 with a similar accuracy of the CHA2DS2-VASc score (AUC 0.750) in predicting "high-risk" AF patients who developed AMI. However, the predictive accuracy of the two clinical-based risk scores was fair. The CHA2DS2-VASc score has fair predictive value for identifying high-risk patients with AF and is not significantly superior to CHADS2 in predicting patients who develop AMI.

  6. CHADS2 and CHA2DS2-VASc scores as bleeding risk indices for patients with atrial fibrillation: the Bleeding with Antithrombotic Therapy Study.

    Science.gov (United States)

    Toyoda, Kazunori; Yasaka, Masahiro; Uchiyama, Shinichiro; Iwade, Kazunori; Koretsune, Yukihiro; Nagata, Ken; Sakamoto, Tomohiro; Nagao, Takehiko; Yamamoto, Masahiro; Gotoh, Jun; Takahashi, Jun C; Minematsu, Kazuo

    2014-05-01

    The CHADS2 and CHA2DS2-VASc scores, that is, ischemic stroke risk indices for patients having atrial fibrillation (AF), may also be useful as bleeding risk indices. Japanese patients with AF, who routinely took oral antithrombotic agents were enrolled from a prospective, multicenter study. The CHADS2 and CHA2DS2-VASc scores were assessed based on information at entry. Scores of 0, 1 and ⩾2 were defined as the low, intermediate and high ischemic risk categories, respectively, for each index. Of 1221 patients, 873 took warfarin, 114 took antiplatelet agents and 234 took both. The annual incidence of ischemic stroke was 0.76% in the low-risk category, 1.46% in the intermediate-risk category and 2.90% in the high-risk category by CHADS2 scores, and 1.44, 0.42 and 2.50%, respectively, by CHA2DS2-VASc scores. The annual incidence of major bleeding in each category was 1.52, 2.19 and 2.25% by CHADS2, and 1.44, 1.69 and 2.24% by CHA2DS2-VASc. After multivariate adjustment, the CHADS2 was associated with ischemia (odds ratio 1.76, 95% confidence interval 1.03-3.38 per 1-category increase) and the CHA2DS2-VASc tended to be associated with ischemia (2.18, 0.89-8.43). On the other hand, associations of the indices with bleeding were weak. In conclusion, bleeding risk increased gradually as the CHADS2 and CHA2DS2-VASc scores increased in Japanese antithrombotic users, although the statistical impact was rather weak compared with their predictive power for ischemic stroke.

  7. CHADS2 score has a better predictive value than CHA2DS2-VASc score in elderly patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Xing YL

    2016-07-01

    Full Text Available Yunli Xing, Qing Ma, Xiaoying Ma, Cuiying Wang, Dai Zhang, Ying Sun Department of Geriatrics and Gerontology, Beijing Friendship Hospital, Capital Medical University, Beijing, People’s Republic of China Aim: The study aims to compare the ability of CHA2DS2-VASc (defined as congestive heart failure, hypertension, age ≥75 years [two scores], type 2 diabetes mellitus, previous stroke, transient ischemic attack, or thromboembolism [TE] [doubled], vascular disease, age 65–74 years, and sex category and CHADS2 (defined as congestive heart failure, hypertension, age ≥75 years, type 2 diabetes mellitus, previous stroke [doubled] scores to predict the risk of ischemic stroke (IS or TE among patients with nonvalvular atrial fibrillation (NVAF.Methods: A total of 413 patients with NVAF aged ≥65 years, and not on oral anticoagulants for the previous 6 months, were enrolled in the study. The predictive value of the CHA2DS2-VASc and CHADS2 scores for IS/TE events was evaluated by the Kaplan–Meier method.Results: During a follow-up period of 1.99±1.29 years, 104 (25.2% patients died and 59 (14.3% patients developed IS/TE. The CHADS2 score performed better than the CHA2DS2-VASc score in predicting IS/TE as assessed by c-indexes (0.647 vs 0.615, respectively; P<0.05. Non-CHADS2 risk factors, such as vascular disease and female sex, were not found to be predictive of IS/TE (hazard ratio 1.518, 95% CI: 0.832–2.771; hazard ratio 1.067, 95% CI: 0.599–1.899, respectively. No differences in event rates were found in patients with the CHADS2 scores of 1 and 2 (7.1% vs 7.8%. It was observed that patients with a CHADS2 score of ≥3 were most in need of anticoagulation therapy.Conclusion: In patients with NVAF aged ≥65 years, the CHADS2 score was found to be significantly better in predicting IS/TE events when compared to the CHA2DS2-VASc score. Patients with a CHADS2 score of ≥3 were associated with high risk of IS/TE events. Keywords: NVAF

  8. Invitation withdrawn: humanitarian action, United Nations peacekeeping, and state sovereignty in Chad.

    Science.gov (United States)

    Karlsrud, John; Felix da Costa, Diana

    2013-10-01

    This paper looks at the three-way relationship between the Government of Chad, humanitarians, and the United Nations Mission in the Central African Republic and Chad (MINURCAT) from 2004 until June 2011. Chad was never comfortable with the international presence of either humanitarians or peacekeepers and asserted its sovereignty increasingly during this period. MINURCAT was deployed in 2008 to protect humanitarian workers and to facilitate the provision of humanitarian assistance in eastern Chad. This association between the UN mission and humanitarian agencies contributed to making the latter the target of repressive practices by the government, such as the imposition of armed escorts. Facing a steep learning curve, Chad and its state officials gradually appropriated the discourse of the humanitarian and international community and ultimately, in 2010, requested the departure of MINURCAT, claiming that they could meet the protection needs of vulnerable populations in eastern Chad on their own.

  9. The frequency of cerebral microbleeds increases with CHADS(2) scores in stroke patients with non-valvular atrial fibrillation.

    Science.gov (United States)

    Song, T-J; Kim, J; Lee, H S; Nam, C M; Nam, H S; Heo, J H; Kim, Y D

    2013-03-01

    Cerebral microbleeds (CMBs) are extravasations of blood from lipohyalinized or amyloid angiopathic cerebral arterioles, and the presence and numbers of CMBs are significantly associated with the development of oral anticoagulation (OA)-related intracranial haemorrhage (ICH). The aim of this study was to investigate whether there is a difference in CMBs burden according to CHADS(2) scores or CHA(2) DS(2) -VASc scores in non-valvular atrial fibrillation (NVAF) patients. We included 550 ischaemic stroke patients who had NVAF and who had undergone brain magnetic resonance imaging (MRI) with gradient-recalled echo (GRE) T2 sequences from our prospective stroke registry between January 2005 and November 2011. We calculated CHADS(2) scores and CHA(2) DS(2) -VASc scores for all patients based on their underlying cardiovascular diseases. The presence, location and number of CMBs were assessed in each patient. We also investigated whether the CMBs were actually associated with the development of ICH during follow-up. The mean patient age was 70.4 ± 10.5 years, and 324 (58.9%) patients were men. One-hundred and seventy-three patients (31.5%) had CMBs detected on GRE MRI. Higher CHADS(2) scores or CHA(2) DS(2) -VASc scores were strongly associated with the presence and number of CMBs. During follow-up of median 3.1 ± 1.6 years, the presence of CMBs was independently associated with the development of ICH, whilst the CHADS(2) scores or CHA(2) DS(2) -VASc scores were not. Considering the positive association between the presence of CMBs and OA-related ICH, our results suggest that the increase in ICH in high-risk groups during OA may be related to an increased burden of CMBs. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  10. Conflict for Resources: Water in the Lake Chad Basin

    Science.gov (United States)

    2009-01-01

    saline and unfit for human use.77 Of the remaining three percent of fresh water, eighty seven percent is located in polar ice. The thirteen percent of...correspondently moved the Sahel south. The change of the ecosystem affected the long term rainfalls which the Lake Chad system depends upon. As a result of the...desertification of the Sahel region causing population migration to the region, competition for water will grow. The competition for water increases

  11. Terrorism Financing. The Socio-Economic and Political Implications of Boko Haram Insurgency in Lake Chad Basin

    Directory of Open Access Journals (Sweden)

    Akepe Linus Enobi

    2016-03-01

    Full Text Available Various Scholars account for the actual date of the evolution of Boko Haram terrorist group. However, the sect came to prominence in 2009 following the death of its leader, Mohammed Yusuf in police custody. Aside from the police act and Mohammed Yusuf’s death, poverty, unemployment, lack of development, high level of illiterates, unkept electoral promises are identified as other reasons for the rise of Boko Haram insurgency. This study involves determination of socio-political and economic impact of Boko Haram insurgency on Lake Chad basin. To achieve this, mixed research method was employed in the study because both primary and secondary data are used. Many factors can be adduced as driving force that motivates Boko Haram activities in the region such as poverty, unemployment, illiteracy, under-development/education defiance region and neglects by government. Finding in the study shows that lack of government support for armed forces and low moral; lack of government political will to fight the insurgency; political interest all contribute in recent time to the rise of terrorist activities in Lake Chad.Finding revealed that the increase in Boko Haram activities in recent time in the region have negatively impact on the socio political/economic activities and these is due partly to increase in terrorist financing. The study suggests therefore that government ability in Lake Chad basin to cut the sources of terrorist finance will significantly affect Boko Haram activities and attacks.

  12. Can mima-like mounds be Vertisol relics (Far North Region of Cameroon, Chad Basin)?

    Science.gov (United States)

    Diaz, Nathalie; Dietrich, Fabienne; Cailleau, Guillaume; Sebag, David; Ngounou Ngatcha, Benjamin; Verrecchia, Eric P.

    2016-05-01

    Non-anthropogenic earth mounds, defined as mima-like mounds in this study, have recently been observed in non-carbonate watersheds along the Sudano-Sahelian belt in the Chad Basin. In the Diamare piedmont (northern Cameroon) they are particularly well developed within stream networks. In less eroded areas, they occur as whaleback, flattened morphologies, or even as buried features. All these shapes are composed of clay-rich sediment associated with high proportions of secondary carbonate nodules and Fesbnd Mn micro-nodules. Their soil structure is prismatic to massive and vertical cracks are observed locally. Grain-size distributions emphasize the clay-rich nature of the sediment, with average clay contents of 32% ± 12.8% (n = 186), which is significantly higher than the clay content in the adjacent sediments in the landscape (mean = 10% ± 4%, n = 21). Moreover, high proportions of smectite characterize the soil, with average contents of 34 ± 7% (n = 25). At the micro-scale, the groundmass has a cross-striated b-fabric, with embedded smooth subangular quartz and feldspar grains of the silt-size fraction. All the characteristics point to altered vertic properties in the clay-rich sediment composing the mima-like mounds. Mima-like mounds are thus interpreted as degraded Vertisols. Compared to present-day Vertisols occurring in the piedmont, mima-like mounds are located upstream. It is thus proposed that the Vertisol areas were more extensive during a former and wetter period than the present-day. Subsequent changing climatic conditions increased erosion, revealing the gilgai micro-relief by preferential erosion in micro-lows rather than in micro-highs. Mima-like mounds of the Chad Basin might thus result from pedogenesis combined with later erosion. These local processes can be inherited from regional climatic variations during the Late Pleistocene-Holocene and likely be related to the African Humid Period.

  13. [Noma in a 4 year-old girl: a case report from Chad].

    Science.gov (United States)

    Cocquempot, K; Javaudin, O; Lerasle, P; Aigle, L

    2014-01-01

    This case report describes a 4-year-old girl in Chad with noma, also called cancrum oris. This acute gangrenous stomatitis has a combined morbidity-mortality rate that can reach 70%. It occurs worldwide but is most common in sub-Saharan Africa in children aged 2 to 16 years. Its pathogenesis is uncertain, but several bacteria including Fusobacterium necrophorum, Prevotella intermedia and Pseudomonas aeruginosa may be responsible for the development of noma, which develops over the oral lesions these bacteria cause. Poverty is its most important risk factor. Due to its rapid course and high lethality, it requires emergency treatment with antibiotics, daily dressing of the lesion, and nutritional rehabilitation. Surgical removal of the remaining necrotic tissue can be followed by reconstructive procedures. Physical and speech therapy should be initiated to prevent functional complications.

  14. Pattern of skin diseases among Central African refugees in Chad

    Directory of Open Access Journals (Sweden)

    Ahmed Fawzi Ismael

    2015-08-01

    Full Text Available Aim: to describe the pattern of skin diseases among refugees attending the dermatology clinic in refugee camps in southern Chad. Methods: A descriptive clinic-based cross-sectional study was done in two refugee camps of people from Republic of Central Africa in Southern Chad. Diagnosis of skin diseases was done through clinical examination by a single dermatologist along with the help of hand lens provided with illumination. Lack of investigations and other skin diagnostic tools prevented further confirmation of diagnosis. Data was manually analyzed and diagnosis was presented as number and percent using the ICD -10 of the World Health Organization. Results: A total of 366 dermatologic diseases were diagnosed in 361 patients. Certain infectious and parasitic diseases and dermatitis/ eczema were the commonest diagnostic categories (39.9% and 22.45; respectively followed by disorders of skin appendices (15% and infections of skin and subcutaneous tissues (13.1%. Tinea barbae /capitis, ringworm and impetigo are the commonest recorded infections (11.5%, 10.1% and 7.9%; respectively. Miliaria and acne vulgaris were the most frequent disorders of skin appendages. Conclusions: Infectious skin diseases are common among refugees. There are urgent needs for health education and promotion of personal hygiene with adequate sanitation as well as availability of diagnostic tests [TAF Prev Med Bull 2015; 14(4.000: 324-328

  15. The interacting role of media violence exposure and aggressive-disruptive behavior in adolescent brain activation during an emotional Stroop task.

    Science.gov (United States)

    Kalnin, Andrew J; Edwards, Chad R; Wang, Yang; Kronenberger, William G; Hummer, Tom A; Mosier, Kristine M; Dunn, David W; Mathews, Vincent P

    2011-04-30

    Only recently have investigations of the relationship between media violence exposure (MVE) and aggressive behavior focused on brain functioning. In this study, we examined the relationship between brain activation and history of media violence exposure in adolescents, using functional magnetic resonance imaging (fMRI). Samples of adolescents with no psychiatric diagnosis or with disruptive behavior disorder (DBD) with aggression were compared to investigate whether the association of MVE history and brain activation is moderated by aggressive behavior/personality. Twenty-two adolescents with a history of aggressive behavior and diagnosis of either conduct disorder or oppositional-defiant disorder (DBD sample) and 22 controls completed an emotional Stroop task during fMRI. Primary imaging results indicated that controls with a history of low MVE demonstrated greater activity in the right inferior frontal gyrus and rostral anterior cingulate during the violent word condition. In contrast, in adolescents with DBD, those with high MVE exhibited decreased activation in the right amygdala, compared with those with low MVE. These findings are consistent with research demonstrating the importance of fronto-limbic structures for processing emotional stimuli, and with research suggesting that media violence may affect individuals in different ways depending on the presence of aggressive traits. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  16. CHA(2)DS(2)-VASc versus CHADS(2) for stroke risk assessment in low-risk patients with atrial fibrillation: a pilot study from a single center of the NCDR-PINNACLE registry.

    Science.gov (United States)

    Piyaskulkaew, Chatchawan; Singh, Tejwant; Szpunar, Susan; Saravolatz, Louis; Rosman, Howard

    2014-05-01

    The CHADS(2) score is widely used to assess the risk of stroke in patients with atrial fibrillation (AF). Patients with score of 0 and 1 are considered 'low risk' and are often treated with aspirin. In a Danish Study, the CHA(2)DS(2)--VASc score was shown to identify low and high-risk subgroups among patients with CHADS(2) score of 0 and 1, with annual risk ranging from 0.84 to 8.18%. This study seeks to assess whether using CHA(2)DS(2)--VASc score will identify high-risk subset of patients with low CHADS(2) scores in an American population. This pilot study examined data from our cardiology fellowship ambulatory clinics from January 2009 to May 2012 using the NCDR-PINNACLE registry. Each cardiology fellow entered patients' data using on-line software developed by the American College of Cardiology. Among 2,048 patients followed at our clinics, 478 had AF. Of those, 161 patients had CHADS(2) score of 0 (44 patients) or 1 (117 patients). Calculating the CHA(2)DS(2)--VASc score in these patients, 12 (7.4%) had score of 0, 50 (31.1%) had score of 1, 66(41%) had score of 2, 31 (19.3%) had score of 3 and 2 (1.2%) had score of 4. Using original CHADS(2) recommendation, warfarin would not be strongly recommended in any of these patients. Utilizing the CHA(2)DS(2)--VASc score, 61.5% of the 161 patients would have a score of 2 or more signifying increased risk where anticoagulation may be indicated. Compared to CHADS(2), CHA(2)DS(2)--VASc may more precisely predict the risk of stroke and anticoagulation strategy in low-risk patients with non-valvular AF.

  17. Hydrological budget of Lake Chad: assessment of lake-groundwater interaction by coupling Bayesian approach and chemical budget

    Science.gov (United States)

    Bouchez, Camille; Goncalves, Julio; Deschamps, Pierre; Seidel, Jean-Luc; Doumnang, Jean-Claude; Sylvestre, Florence

    2014-05-01

    Estimation of lake-groundwater interactions is a crucial step to constrain water balance of lacustrine and aquifer systems. Located in the Sahel, the Lake Chad is at the center of an endorheic basin of 2,5.106 km2. One of the most remarkable features of this terminal lake is that, despite the semi-arid context and high evaporation rates of the area, its waters are fresh. It is proposed in the literature that the solutes are evacuated in the underlying quaternary aquifer bearing witness to the importance of surface water and groundwater exchanges for the chemical regulation of the lake. The water balance of this system is still not fully understood. The respective roles of evaporation versus infiltration into the quaternary aquifer are particularly under constrained. To assess lake-groundwater flows, we used the previous conceptual hydrological model of the lake Chad proposed by Bader et al. (Hydrological Sciences Journal, 2011). This model involves six parameters including infiltration rate. A probabilistic inversion of parameters, based on an exploration of the parameters space through a Metropolis algorithm (a Monte Carlo Markov Chain method), allows the construction of an a posteriori Probability Density Function of each parameter yielding to the best fits between observed lake levels and simulated. Then, a chemical budget of a conservative element, such as chloride, is introduced in the water balance model using the optimal parameters resulting from the Bayesian inverse approach. The model simulates lake level and chloride concentration variations of lake Chad from 1956 up to 2008. Simulated lake levels are in overall agreement with the observations, with a Nash-Sutcliffe efficiency coefficient above 0.94 for all sets of parameters retained. The infiltration value, obtained by such probabilistic inversion approach, accounts for 120±20 mm/yr, representing 5% of the total outputs of the lake. However, simulated chloride concentrations are overestimated in

  18. Spatio-temporal variability of droughts and terrestrial water storage over Lake Chad Basin using independent component analysis

    Science.gov (United States)

    Ndehedehe, Christopher E.; Agutu, Nathan O.; Okwuashi, Onuwa; Ferreira, Vagner G.

    2016-09-01

    Lake Chad has recently been perceived to be completely desiccated and almost extinct due to insufficient published ground observations. Given the high spatial variability of rainfall in the region, and the fact that extreme climatic conditions (for example, droughts) could be intensifying in the Lake Chad basin (LCB) due to human activities, a spatio-temporal approach to drought analysis becomes essential. This study employed independent component analysis (ICA), a fourth-order cumulant statistics, to decompose standardised precipitation index (SPI), standardised soil moisture index (SSI), and terrestrial water storage (TWS) derived from Gravity Recovery and Climate Experiment (GRACE) into spatial and temporal patterns over the LCB. In addition, this study uses satellite altimetry data to estimate variations in the Lake Chad water levels, and further employs relevant climate teleconnection indices (El-Niño Southern Oscillation-ENSO, Atlantic Multi-decadal Oscillation-AMO, and Atlantic Meridional Mode-AMM) to examine their links to the observed drought temporal patterns over the basin. From the spatio-temporal drought analysis, temporal evolutions of SPI at 12 month aggregation show relatively wet conditions in the last two decades (although with marked alterations) with the 2012-2014 period being the wettest. In addition to the improved rainfall conditions during this period, there was a statistically significant increase of 0.04 m/yr in altimetry water levels observed over Lake Chad between 2008 and 2014, which confirms a shift in the hydrological conditions of the basin. Observed trend in TWS changes during the 2002-2014 period shows a statistically insignificant increase of 3.0 mm/yr at the centre of the basin, coinciding with soil moisture deficit indicated by the temporal evolutions of SSI at all monthly accumulations during the 2002-2003 and 2009-2012 periods. Further, SPI at 3 and 6 month scales indicated fluctuating drought conditions at the extreme south

  19. CHADS2 versus CHA2DS2-VASc score in assessing the stroke and throm-boembolism risk stratification in patients with atrial fibrillation:a systematic review and meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Jia-Yuan Chen; Ai-Dong Zhang; Hong-Yan Lu; Jun Guo; Fei-Fei Wang; Zi-Cheng Li

    2013-01-01

    Objective To perform a systematic review and meta-analysis of the predictive abilities of CHADS2 and CHA2DS2-VASc in stroke and thromboembolism risk stratification of atrial fibrillation (AF) patients. Methods We searched PubMed and EMBASE for Eng-lish-language literature on comparisons of the diagnostic performance between CHADS2 and CHA2DS2-VASc in predicting stroke, or sys-temic embolism, in AF. We then assessed the quality of the included studies and pooled the C-statistics and 95%confidence intervals (95%CI). Results Eight studies were included. It was unsuitable to perform a direct meta-analysis because of high heterogeneity. When analyzed as a continuous variable, the C-statistic ranged from 0.60 to 0.80 (median 0.683) for CHADS2 and 0.64-0.79 (median 0.673) for CHA2DS2-VASc. When analyzed as a continuous variable in anticoagulation patients, the subgroup analysis showed that the pooled C-statistic (95%CI) was 0.660 (0.655-0.665) for CHADS2 and 0.667 (0.651-0.683) for CHA2DS2-VASc (no significant difference). For non-anticoagulation patients, the pooled C-statistic (95%CI) was 0.685 (0.666-0.705) for CHADS2 and 0.675 (0.656-0.694) for CHA2DS2-VASc (no significant differ-ence). The average ratio of endpoint events in the low-risk group of CHA2DS2-VASc was less than CHADS2 (0.41%vs. 0.94%, P<0.05). The average proportion of the moderate-risk group of CHA2DS2-VASc was lower than CHADS2 (11.12%vs. 30.75%, P<0.05). Conclu-sions The C-statistic suggests a similar clinical utility of the CHADS2 and CHA2DS2-VASc scores in predicting stroke and thromboem-bolism, but CHA2DS2-VASc has the important advantage of identifying extremely low-risk patients with atrial fibrillation, as well as classi-fying a lower proportion of patients as moderate risk.

  20. Bacillus anthracis Diversity and Geographic Potential across Nigeria, Cameroon and Chad: Further Support of a Novel West African Lineage.

    Science.gov (United States)

    Blackburn, Jason K; Odugbo, Moses Ode; Van Ert, Matthew; O'Shea, Bob; Mullins, Jocelyn; Perreten, Vincent; Perrenten, Vincent; Maho, Angaya; Hugh-Jones, Martin; Hadfield, Ted

    2015-01-01

    Zoonoses, diseases affecting both humans and animals, can exert tremendous pressures on human and veterinary health systems, particularly in resource limited countries. Anthrax is one such zoonosis of concern and is a disease requiring greater public health attention in Nigeria. Here we describe the genetic diversity of Bacillus anthracis in Nigeria and compare it to Chad, Cameroon and a broader global dataset based on the multiple locus variable number tandem repeat (MLVA-25) genetic typing system. Nigerian B. anthracis isolates had identical MLVA genotypes and could only be resolved by measuring highly mutable single nucleotide repeats (SNRs). The Nigerian MLVA genotype was identical or highly genetically similar to those in the neighboring countries, confirming the strains belong to this unique West African lineage. Interestingly, sequence data from a Nigerian isolate shares the anthrose deficient genotypes previously described for strains in this region, which may be associated with vaccine evasion. Strains in this study were isolated over six decades, indicating a high level of temporal strain stability regionally. Ecological niche models were used to predict the geographic distribution of the pathogen for all three countries. We describe a west-east habitat corridor through northern Nigeria extending into Chad and Cameroon. Ecological niche models and genetic results show B. anthracis to be ecologically established in Nigeria. These findings expand our understanding of the global B. anthracis population structure and can guide regional anthrax surveillance and control planning.

  1. Bacillus anthracis Diversity and Geographic Potential across Nigeria, Cameroon and Chad: Further Support of a Novel West African Lineage.

    Directory of Open Access Journals (Sweden)

    Jason K Blackburn

    Full Text Available Zoonoses, diseases affecting both humans and animals, can exert tremendous pressures on human and veterinary health systems, particularly in resource limited countries. Anthrax is one such zoonosis of concern and is a disease requiring greater public health attention in Nigeria. Here we describe the genetic diversity of Bacillus anthracis in Nigeria and compare it to Chad, Cameroon and a broader global dataset based on the multiple locus variable number tandem repeat (MLVA-25 genetic typing system. Nigerian B. anthracis isolates had identical MLVA genotypes and could only be resolved by measuring highly mutable single nucleotide repeats (SNRs. The Nigerian MLVA genotype was identical or highly genetically similar to those in the neighboring countries, confirming the strains belong to this unique West African lineage. Interestingly, sequence data from a Nigerian isolate shares the anthrose deficient genotypes previously described for strains in this region, which may be associated with vaccine evasion. Strains in this study were isolated over six decades, indicating a high level of temporal strain stability regionally. Ecological niche models were used to predict the geographic distribution of the pathogen for all three countries. We describe a west-east habitat corridor through northern Nigeria extending into Chad and Cameroon. Ecological niche models and genetic results show B. anthracis to be ecologically established in Nigeria. These findings expand our understanding of the global B. anthracis population structure and can guide regional anthrax surveillance and control planning.

  2. Safer roads in Chad : recommendations for low-cost road safety measures in Chad. On behalf of The World Bank, International Bank for Reconstruction and Development.

    NARCIS (Netherlands)

    Sluis, J. van der

    2002-01-01

    In the framework of the National Transport Support Project, SWOV provided local experts in Chad with technical assistance on road safety. The assistance focused on the development of a comprehensive road safety strategy and physical road safety improvements on urban and inter-urban roads. The proble

  3. Relationship of CHA2DS2-VASc and CHADS2 score to left atrial remodeling detected by velocity vector imaging in patients with atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Yihui Li

    Full Text Available BACKGROUND: The CHADS2/CHA2DS2-VASc scores are used to predict thrombo-embolic/stroke in patients with nonvalvular atrial fibrillation (AF. Nevertheless, limited data are available regarding the association between these risk stratification for stroke and left atrial (LA remodeling status of AF patients. The purpose of this study was to explore the association between these scores and LA remodeling status assessed quantificationally by echocardiography in AF patients. METHODS: One hundred AF patients were divided into 3 groups based on the CHA2DS2-VASc/CHADS2 score: the score of 0 (low stroke risk, the score of 1 (moderate stroke risk and the score of ≥2 (high stroke risk. All patients were performed through conventional and velocity vector imaging echocardiography. Echocardiographic parameters: maximum LA volume index (LAVImax, LA total emptying fraction (LAEFt and LA mean strain were obtained to assess quantificationally LA remodeling status. RESULTS: On categorizing with CHA2DS2-VASc, the score of 1 group showed augment in LAVImax and attenuation in LA mean strain derived from VVI, compared with the score of 0 group (LAVImax: 40.27±21.91 vs. 26.79±7.87, p=0.002; LA mean strain: 15.18±6.36 vs. 22±8.54, p=0.001. On categorizing with the CHADS2 score, similar trends were seen between the score of ≥2 and 1 groups (LAVImax: 43.72±13.77 vs. 31.41±9.50, p<0.001; LA mean strain: 11.01±5.31 vs. 18.63±7.00, p<0.001. With multivariate logistic regression, LAVImax (odds ratio: 0.92 , 95% C=I: 0.85 to 0.98, p= 0.01 and LA mean strain reflecting LA remodeling (odds ratio: 1.10, 95% CI: 1.02 to 1.19, p=0.01 were strongly predictive of the CHA2DS2-VASc score of 0. CONCLUSIONS: The superiority of the CHADS2 score may lay in identifying LA remodeling of AF patients with high stroke risk. Whereas, the CHA2DS2-VASc score was better than the CHADS2 score at identifying LA remodeling of AF patients presenting low stroke risk.

  4. CHADS2 Scores in the Prediction of Major Adverse Cardiovascular Events in Patients with Cushing's Syndrome

    Science.gov (United States)

    Chuang, Mei-Hua; Chuang, Tzyy-Ling; Huang, Kung-Yung; Lyu, Shaw-Ruey; Huang, Chih-Yuan; Lee, Ching-Chih

    2014-01-01

    Vascular events are one of the major causes of death in case of Cushing's syndrome (CS). However, due to the relative low frequency of CS, it is hard to perform a risk assessment for these events. As represented congestive heart failure (C), hypertension (H), age (A), diabetes (D), and stroke (S), the CHADS2 score is now accepted to classify the risk of major adverse cardiovascular events (MACEs) in patients with atrial fibrillation. In this study, participants were enrolled from the National Health Research Institute Database (NHIRD) of Taiwan, and we reviewed 551 patients with their sequential clinically diagnosed CS data between 2002 and 2009 in relation to MACEs risk using CHADS2 score. Good correlation could be identified between the CS and CHADS2 score (AUC = 0.795). Our results show that patients with CS show significantly higher risk of vascular events and the CHADS2 score could be applied for MACEs evaluation. Adequate lifestyle modifications and aggressive cardiovascular risks treatment are suggested for CS patients with higher CHADS2 score. PMID:25101124

  5. Palynological evidence for gradual vegetation and climate changes during the "African Humid Period" termination at 13° N from a Mega-Lake Chad sedimentary sequence

    Directory of Open Access Journals (Sweden)

    P. G. C. Amaral

    2012-06-01

    Full Text Available Located at the transition between the Saharian and Sahelian zones, at the center of one of the largest endoreic basins, the Lake Chad is ideally located to record regional environmental changes that occurred in the past. However, until now, no continuous archive from Lake Chad covering the Holocene has been studied. In this paper, we present pollen data from the first Holocene sedimentary sequence collected in Lake Chad (13° N; 14° E; Sahel region. Dated between ca. 6700 and ca. 5000 cal yr BP, this record encompasses the termination of the African Humid Period (AHP. Vegetational reconstructions are based on standard analyses of the pollen diagrams and are strengthened by quantitative approaches. Potential biomes that occurred at that time around Mega-Lake Chad are reconstructed using the biomization method and mean annual precipitation is estimated using the modern analogues technique.

    Results show that between ca. 6700 and ca. 6050 cal yr BP, a vegetation close to humid woodland or humid savanna, including elements currently found much further southward, thrived in the vicinity and/or the extra-local environment of the Mega-Lake Chad in place of the modern steppe, dry woodland and desert vegetation observed today. At the same time, montane forest populations extended further southward on the Adamawa plateau. This vegetation distribution is supported by biome reconstructions as well as by mean annual precipitation estimates of ca. 800 (−400/+700 mm for the period. The high abundance of lowland humid pollen taxa is interpreted as the result of a northward migration of the corresponding plants during the AHP driven by more favorable climatic conditions. Our interpretation in favor of a regional vegetation response to climatic changes is supported by other pollen data from several Northwestern African records. However, we cannot rule out that an increase of Chari-Logone inputs into the Mega-Lake Chad due to variations in hydrological

  6. Streptomyces gamaensis sp. nov., a novel actinomycete with antifungal activity isolated from soil in Gama, Chad.

    Science.gov (United States)

    Zhao, Shanshan; Ye, Lan; Liu, Chongxi; Abagana, Adam Yacoub; Zheng, Weiwei; Sun, Pengyu; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2017-04-01

    During an investigation exploring potential sources of novel species and natural products, a novel actinomycete with antifungal activity, designated strain NEAU-Gz11(T), was isolated from a soil sample, which was collected from Gama, Chad. The isolate was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain NEAU-Gz11(T) belongs to the genus Streptomyces with high sequence similarity to Streptomyces hiroshimensis JCM 4098(T) (98.0 %). Similarities to other type strains of the genus Streptomyces were lower than 98.0 %. However, the physiological and biochemical characteristics and low levels of DNA-DNA relatedness could differentiate the isolate genotypically and phenotypically from S. hiroshimensis JCM 4098(T). Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces gamaensis sp. nov. is proposed. The type strain is NEAU-Gz11(T) (=CGMCC 4.7304(T)=DSM 101531(T)).

  7. Coming Hard: The Primacy of Embodied Stress Responses in High Poverty Schools

    NARCIS (Netherlands)

    Paulle, B.

    2014-01-01

    Informed by nearly six years of teaching experiences in high poverty schools of New York and Amsterdam, this ethnographic comparison examines the following question: Even though they often say they "know better", why do so many teens from low income neighborhoods behave in aggressively disruptive wa

  8. Coming Hard: The Primacy of Embodied Stress Responses in High Poverty Schools

    NARCIS (Netherlands)

    Paulle, B.

    2014-01-01

    Informed by nearly six years of teaching experiences in high poverty schools of New York and Amsterdam, this ethnographic comparison examines the following question: Even though they often say they "know better", why do so many teens from low income neighborhoods behave in aggressively disruptive

  9. Efforts to Unravel the Cause of Shrinkage of Lake Chad: Development of Hydrologic Real-time Observatory Network in the Lake Chad Basin

    Science.gov (United States)

    Lee, J.; Ichoku, C. M.; Bolten, J. D.; Policelli, F. S.; Djimadoumngar, K. N.; Abdullahi, S. I.; Bila, M. D.; Djoret, D.; Ibrahim, G.; Selker, J. S.; Hochreutener, R.; Annor, F. O.

    2015-12-01

    Lake Chad, the fourth largest lake in Africa, is well known as a shrinking lake due to adverse impact of climate change and increased population during drought periods in the 1980s and 1990s. While the shrinkage of the Lake has been studied broadly using remote sensing data, the main cause of shrinkage is still uncertain due to limited availability of ground-truth data. Lack of infrastructure, insecure site conditions, vandalism, and limited site accessibility make it difficult to establish a real-time monitoring network in many parts of Africa including the Lake Chad Basin. For a better understanding of how the Lake responds to the change of weather patterns and other hydrologic processes such as runoff, groundwater flow, and evapotranspiration, a real-time monitoring network is essential in the region. In early 2015, a team from NASA, the Lake Chad Basin Commission, and the University of Missouri - Kansas City set up a hydrologic real-time observatory network in the Chari-Logone catchment, the main feeder of water to the Lake, to monitor meteorological conditions, soil moisture, and groundwater. The TAHMO (Trans-African Hydro-Meteorological Observatory) weather stations were adopted to monitor rainfall, relative humidity, solar radiation, wind speed, and temperature. The present study shows preliminary analysis of the correlations between meteorological and hydrological parameters from real-time monitoring data in the Chari-Logone catchment. We also discuss the importance of partnership with local government and community involvement for data collection and share for sustainable hydrological research in the Lake Chad Basin.

  10. R2(GFRCHADS2 and R2(GFRCHA2DS2VASc schemes improved the performance of CHADS2 and CHA2DS2VASc scores in death risk stratification of Chinese older patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Fu S

    2017-08-01

    lower levels of GFR and GFR <60 mL/min/1.73 m2 had a significantly high death risk, and those with lower levels of CrCl or CrCl <60 mL/min had a significantly or modestly high death risk. There was significantly better performance of GFR-based schemes and moderately better performance of CrCl-based schemes in death risk stratification compared with CHADS2 and CHA2DS2VASc scores. Keywords: atrial fibrillation, CHADS2, CHA2DS2VASc, older patients, creatinine clearance, glomerular filtration rate

  11. PHYSICAL ACTIVITY INDEX FOR CHILDREN: A COMPARISON OF LITERATURE VALUES AND EPA'S CHAD

    Science.gov (United States)

    The physical activity index (PAI) is a measure of an individual's energy expenditure level (and thus oxygen consumption) calculated as a time-weighted average of metabolic equivalents (METS) over the individual's activities. Many exposure models rely upon EPA's CHAD data base to ...

  12. Chad: An Overview of a Country Plagued with Internal Strife and Regional Conflict

    Science.gov (United States)

    2012-04-09

    2010, 2. 13 Abubakar, Dauda. "SELECT LIBRARY." Credo Reference Home. http://www.credoreference.com/entry.do?ta=berkgpusnbn&uh=chad (accessed February...32 BIBLIOGRAPHY Abubakar, Dauda. "SELECT LIBRARY." Credo Reference Home. http://www.credoreference.com/entry.do

  13. Crater palaeolakes in the Tibesti mountains (Central Sahara, North Chad) - New insights into past Saharan climates

    Science.gov (United States)

    Kröpelin, Stefan; Dinies, Michèle; Sylvestre, Florence; Hoelzmann, Philipp

    2016-04-01

    For the first time continuous lacustrine sections were sampled from the volcanic Tibesti Mountains (Chad): In the 900 m deep crater of Trou au Natron at Pic Toussidé (3,315 m a.s.l.) and from the 800 m deep Era Kohor, the major sub-caldera of Emi Koussi (3,445 m a.s.l.). The remnant diatomites on their slopes are located 360 m (Trou au Natron) and 125 m (Era Kohor) above the present day bottom of the calderas. These sediments from highly continental positions in the central Sahara are keys for the reconstruction of the last climatic cycles (Kröpelin et al. 2015). We report first results from sedimentary-geochemical (total organic and total inorganic carbon contents; total nitrogen; major elements; mineralogy) and palynological analyses for palaeo-environmental interpretations. The diatomites from the Trou au Natron comprise 330 cm of mostly calcitic sediments with relatively low organic carbon (fern stands. Regional pollen rain-e.g. grasses and wormwood-is scarcely represented. Golden algae dominate in the lower section. The results of the first palynological samples suggest a small sedimentation basin. Two 14C-dated charcoals out of the upper part of the section indicate mid-Holocene ages and a linear extrapolation based on a sediment accumulation rate of 1.4mma-1 would lead to tentative dates of ~8650 cal a BP for basal lacustrine sediments and ~4450 cal a BP for the cessation of this lacustrine sequence. The diatomites from the Era Kohor reflect a suite of sections that in total sum up to 145 cm of mostly silica-based sediments with very low carbon contents (< 2% TC). Calcite dominated sediments are only present in the topmost 15 cm. Grasses and wormword are dominating throughout the sequence, probably reflecting the main constituents of the regional vegetation. Cattail (Typha/Sparganium) and especially milfoil (Myriophyllum) are recorded abundantly and continuously throughout the sequence. In combination with green algae like Pediastrum the first pollen

  14. Incidence, etiology, and determinants associated with acute diarrhea among French forces deployed to Chad.

    Science.gov (United States)

    Pommier de Santi, Vincent; Nicand, Elisabeth; Lagathu, Gisèle; Michel, Rémy; Rosenmayr, Georg; Raingeval, Jean-Baptiste; Samy, Julien; Boutin, Jean-Paul; Marimoutou, Catherine

    2011-01-01

    This study assesses, for the first time, the incidence, etiology, and determinants associated with traveler's diarrhea (TD) among French forces deployed to N'Djamena, Chad. A prospective study was conducted based on physician consultation for diarrhea during a 5-month French forces mandate. Diarrhea was defined as ≥3 loose stools in a 24-hour period or ≥2 loose stools within the last 8 hours. For each diarrheic episode, an anonymous physician-administered questionnaire was completed and a stool sample collected. Samples were tested for parasites, bacteria, and enteric viruses. Global incidence rate was calculated using the mean number of soldiers based in N'Djamena (n = 1,024) over the 5-month period, as denominator. Incidence rates were also estimated for each of the eleven 2-week periods of stay. A case-crossover analysis estimated determinants associated with diarrhea. A total of 240 cases of diarrhea were notified by military physicians, resulting in a global incidence rate of 49 cases per 1,000 person-months (PM). The cumulative individual risk of developing diarrhea during the study period was 0.23. The incidence per 2-week stay began at 8.8/1,000 PM, rose to 54.4/1,000 PM after 1 month, and decreased after 2 months. Of the 240 cases reported, stool samples were obtained for 196 cases. Pathogens were identified in 40% of samples; enteric viruses were predominant (28.1%). Three determinants were associated with diarrhea by multivariate analysis: diarrhea in the close circle [OR: 3.8 (2.0-7.0)]; always eating at the military mess [OR: 0.2 (0.1-0.5)]; or staying in a temporary encampment [OR: 0.3 (0.1-0.8)]. This study found a high frequency of enteric viruses and a high risk of person-to-person transmission associated with diarrhea. Eating at the military mess or staying in a temporary encampment conferred a protective effect. In addition to food-borne disease prevention, stringent hygiene measures are required to break transmission of diarrhea during

  15. CHADS2 Scores in the Prediction of Major Adverse Cardiovascular Events in Patients with Cushing’s Syndrome

    Directory of Open Access Journals (Sweden)

    Yuh-Feng Wang

    2014-01-01

    Full Text Available Vascular events are one of the major causes of death in case of Cushing’s syndrome (CS. However, due to the relative low frequency of CS, it is hard to perform a risk assessment for these events. As represented congestive heart failure (C, hypertension (H, age (A, diabetes (D, and stroke (S, the CHADS2 score is now accepted to classify the risk of major adverse cardiovascular events (MACEs in patients with atrial fibrillation. In this study, participants were enrolled from the National Health Research Institute Database (NHIRD of Taiwan, and we reviewed 551 patients with their sequential clinically diagnosed CS data between 2002 and 2009 in relation to MACEs risk using CHADS2 score. Good correlation could be identified between the CS and CHADS2 score (AUC=0.795. Our results show that patients with CS show significantly higher risk of vascular events and the CHADS2 score could be applied for MACEs evaluation. Adequate lifestyle modifications and aggressive cardiovascular risks treatment are suggested for CS patients with higher CHADS2 score.

  16. Sediment composition, varve formation and paleolimnology of Lake Yoa, NE Chad

    Science.gov (United States)

    Karls, Jens; Kröpelin, Stefan; Just, Janna; Kuper, Jan; Rethemeyer, Janet; Viehberg, Finn; Wennrich, Volker; Melles, Martin

    2014-05-01

    Lake Yoa (19.03° N / 20.31° E, NE Chad, 380 m a.s.l.) is a groundwater-fed lake in the central Sahara situated in a deflation hollow below an escarpment close to the Chadian-Libyan border. The lake persists since the onset of the Holocene "Green Sahara" 11,000 years ago. It has survived the end of the early to mid-Holocene wet phase until today due to extensive groundwater supply from the so-called Nubian Sandstone Aquifer System. Continuous lake sedimentation has generated an unparalleled depositional archive of Holocene climatic and environmental changes in the presently hyper-arid central Sahara, which is characterized by less than 10 mm of annual precipitation against an annual evaporation of more than 6,000 mm. An earlier 7.5 m long sediment core from Lake Yoa (OUNIK03/04) has provided unprecedented insight into the past 6,000 years cal BP (Kröpelin et al. 2008). Within the framework of the Collaborative Research Centre 806 "Our Way to Europe - Culture-Environment Interaction and Human Mobility in the Late Quaternary", the record was extended to the base of the lake sediments at a depth of 16.25 m below the lake floor in 2010 (core Co1240). Most of the sedimentary column is annually to sub-annually laminated. Varve counting resulted in a highly resolved robust chronology that is supported by AMS radiocarbon dating of various components (bulk sediment, bulk carbonate, humic acids, semi-aquatic plants and charcoal). The core material was examined in a multiproxy approach, including non-destructive geophysical (e.g. magnetic susceptibility) and elemental (XRF scanning) measurements as well as sedimentological, geochemical and paleontological analyses. The data not only give detailed information on changes in the lake body and catchment of Lake Yoa but also on the regional climate and environmental history during the past 11,000 years cal BP. Kröpelin et al. (2008). Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years. Science 320: 765

  17. Is drinking water from 'improved sources' really safe? A case study in the Logone valley (Chad-Cameroon).

    Science.gov (United States)

    Sorlini, S; Palazzini, D; Mbawala, A; Ngassoum, M B; Collivignarelli, M C

    2013-12-01

    Within a cooperation project coordinated by the Association for Rural Cooperation in Africa and Latin America (ACRA) Foundation, water supplies were sampled across the villages of the Logone valley (Chad-Cameroon) mostly from boreholes, open wells, rivers and lakes as well as from some piped water. Microbiological analyses and sanitary inspections were carried out at each source. The microbiological quality was determined by analysis of indicators of faecal contamination, Escherichia coli, Enterococci and Salmonellae, using the membrane filtration method. Sanitary inspections were done using WHO query forms. The assessment confirmed that there are several parameters of health concern in the studied area; bacteria of faecal origins are the most significant. Furthermore, this study demonstrated that Joint Monitoring Programme (JMP) classification and E. coli measurement are not sufficient to state water safety. In fact, in the studied area, JMP defined 'improved sources' may provide unsafe water depending on their structure and sources without E. coli may have Enterococci and Salmonellae. Sanitary inspections also revealed high health risks for some boreholes. In other cases, sources with low sanitary risk and no E. coli were contaminated by Enterococci and Salmonellae. Better management and protection of the sources, hygiene improvement and domestic water treatment before consumption are possible solutions to reduce health risks in the Logone valley.

  18. Situational analysis of infant and young child nutrition policies and programmatic activities in Chad.

    Science.gov (United States)

    Wuehler, Sara E; Nadjilem, Djasndibye

    2011-04-01

    Progress towards reducing mortality and malnutrition among children nutrition in the Sahel', starting with an analysis of current activities related to infant and young child nutrition (IYCN). The main objectives of the situational analysis are to compile, analyse, and interpret available information on infant and child feeding, and the nutrition situation of children nutrition policy was yet ratified in Chad, so the target of many documents reviewed was the malnourished child. Researchers have identified some barriers to optimal feeding practices. However, the majority of these surveys were small scale, so they do not necessarily provide information relevant to the general population. Expanded surveys would be needed for developing evidence-based educational messages targeted to local needs. Reviewed training materials and related programmes being implemented in Chad provide specific guidance for nearly all of the key IYCN topics, except for appropriate feeding choices for the prevention of mother-to-child transmission of HIV. Some of the programmes were intended for national coverage, but we could not confirm whether these programmes were actually implemented nationally. Monitoring and evaluation reports were available for some small-scale programmes, but few of these evaluated whether IYCN-specific programme components were implemented as designed and none evaluated whether participants adopted the promoted feeding practices. Establishment of the policy and programme framework has commenced for improving IYCN practices. Formative research is needed to guide the development of evidence-based training materials and programmes to address the nutritional needs of infants and children. Once more directed programmes are established, there is a further need for rigorous monitoring and evaluation to ensure that training is adequate, programmes are implemented as designed, and effective programmes are identified for expansion nationally. Evaluations are also needed to

  19. Megalake Chad impact on climate and vegetation during the late Pliocene and the mid-Holocene

    Directory of Open Access Journals (Sweden)

    C. Contoux

    2013-07-01

    Full Text Available Given the growing evidence for megalakes in the geological record, assessing their impact on climate and vegetation is important for the validation of palaeoclimate simulations and therefore the accuracy of model–data comparison in lacustrine environments. Megalake Chad (MLC occurrences are documented not only for the mid-Holocene but also for the Mio-Pliocene (Schuster et al., 2009. At this time, the surface covered by water would have reached up to ~350 000 km2 (Ghienne et al., 2002; Schuster et al., 2005; Leblanc et al., 2006, making it an important evaporation source, possibly modifying climate and vegetation in the Chad Basin. We investigated the impact of such a giant continental water area in two different climatic backgrounds within the Paleoclimate Model Intercomparison Project phase 3 (PMIP3: the late Pliocene (3.3 to 3 Ma, i.e. the mid-Piacenzian warm period and the mid-Holocene (6 kyr BP. In all simulations including MLC, precipitation is drastically reduced above the lake surface because deep convection is inhibited by overlying colder air. Meanwhile, convective activity is enhanced around MLC because of the wind increase generated by the flat surface of the megalake, transporting colder and moister air towards the eastern shore of the lake. The effect of MLC on precipitation and temperature is not sufficient to widely impact vegetation patterns. Nevertheless, tropical savanna is present in the Chad Basin in all climatic configurations, even without MLC presence, showing that the climate itself is the driver of favourable environments for sustainable hominid habitats.

  20. Community health outreach program of the Chad-Cameroon petroleum development and pipeline project.

    Science.gov (United States)

    Utzinger, Jürg; Wyss, Kaspar; Moto, Daugla D; Tanner, Marcel; Singer, Burton H

    2004-02-01

    applying a systemic approach. Other innovations of the project in general, and the CHOP in particular, are the strong emphases on institutional-capacity building, integration, and sustainability. In countries like Chad and Cameroon, there are serious shortages of well-qualified health personnel. The CHOP described in this article provides leverage for initiating better healthcare that will reduce the high burden of disease in the developing world. Reducing mortality rates for infants and children younger than 5 years in sub-Saharan Africa requires massive scaling-up of malaria-control interventions (eg, large-scale distribution of ITNs to protect millions of African children), thereby approaching the Abuja targets (see Armstrong Schellenberg et al). The local NGOs that took a lead within the framework of the CHOP in the distribution of ITNs and accompanying health education messages can extend these activities to communities living outside the vicinity of the project area. Serious shortcomings of the current CHOP, consistently identified by the external monitoring groups, include the lack of a regional health plan, cumulative impact assessment, and provision of clean water and sanitation outside the narrowly defined project area. This point is of central importance, particularly for Chad, where access to clean water and improved sanitation facilities is low. Another limitation of the current CHOP is the insufficient amount of significance addressed to tuberculosis and the apparent lack of concerted control efforts against HIV infection, AIDS, and tuberculosis. These criticisms, however, must be balanced against the lack of clarity in international discourse about the proper extent of responsibility of the corporate sector for dealing with the health problems of countries in which they do business. In an elegant analysis, the environmental risk factor "unsafe water, sanitation and hygiene" was shown to be one of the major contributors to loss of healthy life, particularly

  1. Association between CHADS2 score and long-term atrial fibrillation recurrence rate after catheter ablation

    Institute of Scientific and Technical Information of China (English)

    胡晓锋

    2014-01-01

    Objective To investigate the association between CHADS2score and long-term(≥3 years)outcomes post catheter ablation in patients with atrial fibrillation(AF).Methods AF patients who received single catheter ablation in our hospital from January 2004 to March 2009 in our department were included and patients received regular follow-up.AF recurrence was defined as the occurrence of atrial arrhythmias(AF,atrial flutter and atrial tachycardia)recorded by electrocardiogram monitor(≥30 seconds)after ablation during follow-up period(after

  2. Sahara and Sahel vulnerability to climate changes, lessons from the past - Focus on the Ounianga lake region (NE Chad)

    Science.gov (United States)

    Grenier, Christophe; Zheng, Weipeng; Lezine, Anne-Marie; Braconnot, Pascale; Krinner, Gerhard; Harel, Marie-Alice; Anglade, Juliette; Paillou, Philippe

    2010-05-01

    Reconstructions from sedimentary records and climate modelling results show an overall drying in the African Sahara and Sahel during the Holocene. Was this change abrupt or gradual, and amplified or not through vegetation change and feedbacks to the atmosphere is still the subject of debate. For instance, while [deMenocal et al. 2000] show from oceanic sediments off the Mauritanian coast, that the end of the African Humid Period (AHP), recorded 5500 years ago, was abrupt. [Kroepelin et al., 2008] studied recently sediments from lake Yoa (Ounianga region, NE Chad) and derived a gradual climate change. The present paper focusses on the Ounianga lake region (NE Chad) where the Kropelin et al. study was carried on. We investigate hydrological reconstructions based on climate scenarios and modelling of water dynamics of the catchment area of the lakes. Under modern conditions, Ounianga lakes are maintained in a hyper arid environment due to groundwater inputs from the Nubian Sandstone Aquifer System (NSAS), a very large aquifer covering parts of Chad, Libya, Egypt and Sudan. Moreover, these lakes are situated within 200 km of the Tibesti Mountains ranging over 3000 meters where rainfall is larger than in the plains. So the issue arises as to what extent distant water inputs from the Tibesti and local groundwater recharge could have maintained high lake levels during the climatic transition phase and/or could explain some features analysed from the sediments regarding the abruptness of the salinisation of lake Yoa roughly by 3900 BP. The topography of the region is analyzed from SRTM data to obtain paleo river networks and compared with satellite radar pictures (PALSAR) to identify key features in the Yoa catchement area [refer to Grenier et al. 2009]. A hydrological model is constructed including the river network and depressions interpreted as lakes and modeled dynamically as reservoirs. The groundwater input from the aquifer is modeled within the Cast3m finite element

  3. Characteristics of Lake Chad Level Variability and Links to ENSO, Precipitation, and River Discharge

    Directory of Open Access Journals (Sweden)

    Churchill Okonkwo

    2014-01-01

    Full Text Available This study used trend, correlation, and wavelet analysis to characterize Lake Chad (LC level fluctuations, river discharge, El Niño Southern Oscillation (ENSO, and precipitation regimes and their interrelationships. Linear correlation results indicate a negative association between ENSO and LC level, river discharge and precipitation. Trend analysis shows increasing precipitation in the Lake Chad Basin (LCB but decreasing LC level. The mode of interannual variability in LC level, rainfall, and ENSO analyzed using wavelet analysis is dominated by 3-4-year periods. Results show that variability in ENSO could explain only 31% and 13% of variations in LC level at Kindjeria and precipitation in the northern LCB, respectively. The wavelet transform coherency (WTC between LC level of the southern pool at Kalom and ENSO is statistically significant at the 95% confidence level and phase-locked, implying a cause-and-effect association. These strong coherencies coincide with the La Niña years with the exception of 1997-1998 El Niño events. The WTC shows strong covariance between increasing precipitation and LC level in the northern pool at a 2- to 4-year band and 3- to 4-year band localized from 1996 to 2010. Implications for water resource planning and management are discussed.

  4. [Morbidity patterns in three nomadic communities in Chari-Baguirmi and Kanem, Chad].

    Science.gov (United States)

    Daugla, D M; Daoud, S; Tanner, M; Zinsstag, J; Schelling, E

    2004-01-01

    Within the framework of an multidisciplinary research and action program, morbidity patterns were assessed in three nomadic communities, i.e., Fulani, Arab cattle breeders and Arab camel breeders, living in Chari-Baguirmi and Kanem, Chad. This is the first data about the health of Chadian nomadic pastoralists who account for approximately 6% of the total population. A total of 1092 women, men and children were interviewed and examined in the course of three surveys carried out by a physician during the dry and rainy season. Nomads reporting no health problems were rare. Tuberculosis was suspected in 4.6% of adults after clinical examination and bronchopulmonary disorders in children less than five years of age. Febrile diarrhea was more prevalent during the wet season when access to clean drinking water was more difficult. Simple malaria was rarely diagnosed in Arabs during the dry season. In contrast simple malaria was frequent in Fulani who stay in the vicinity of Lake Chad during the dry period. Protein-energy malnutrition was observed in only 3 of 328 children younger than 15 years of age.

  5. Characteristics of Lake Chad level variability and links to ENSO, precipitation, and river discharge.

    Science.gov (United States)

    Okonkwo, Churchill; Demoz, Belay; Gebremariam, Sium

    2014-01-01

    This study used trend, correlation, and wavelet analysis to characterize Lake Chad (LC) level fluctuations, river discharge, El Niño Southern Oscillation (ENSO), and precipitation regimes and their interrelationships. Linear correlation results indicate a negative association between ENSO and LC level, river discharge and precipitation. Trend analysis shows increasing precipitation in the Lake Chad Basin (LCB) but decreasing LC level. The mode of interannual variability in LC level, rainfall, and ENSO analyzed using wavelet analysis is dominated by 3-4-year periods. Results show that variability in ENSO could explain only 31% and 13% of variations in LC level at Kindjeria and precipitation in the northern LCB, respectively. The wavelet transform coherency (WTC) between LC level of the southern pool at Kalom and ENSO is statistically significant at the 95% confidence level and phase-locked, implying a cause-and-effect association. These strong coherencies coincide with the La Niña years with the exception of 1997-1998 El Niño events. The WTC shows strong covariance between increasing precipitation and LC level in the northern pool at a 2- to 4-year band and 3- to 4-year band localized from 1996 to 2010. Implications for water resource planning and management are discussed.

  6. Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus bahrelghazali: Mio-Pliocene hominids from Chad.

    Science.gov (United States)

    Lebatard, Anne-Elisabeth; Bourlès, Didier L; Duringer, Philippe; Jolivet, Marc; Braucher, Régis; Carcaillet, Julien; Schuster, Mathieu; Arnaud, Nicolas; Monié, Patrick; Lihoreau, Fabrice; Likius, Andossa; Mackaye, Hassan Taisso; Vignaud, Patrick; Brunet, Michel

    2008-03-04

    Ages were determined at two hominid localities from the Chad Basin in the Djurab Desert (Northern Chad). In the Koro Toro fossiliferous area, KT 12 locality (16 degrees 00'N, 18 degrees 53'E) was the site of discovery of Australopithecus bahrelghazali (Abel) and in the Toros-Menalla fossiliferous area, TM 266 locality (16 degrees 15'N, 17 degrees 29'E) was the site of discovery of Sahelanthropus tchadensis (Toumaï). At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3-3.5 Ma) at KT 12 and late Miocene ( approximately 7 Ma) at TM 266. Atmospheric (10)Be, a cosmogenic nuclide, was used to quasicontinuously date these sedimentary units. The authigenic (10)Be/(9)Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 +/- 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 (10)Be/(9)Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock.

  7. African 1, an epidemiologically important clonal complex of Mycobacterium bovis dominant in Mali, Nigeria, Cameroon, and Chad.

    Science.gov (United States)

    Müller, Borna; Hilty, Markus; Berg, Stefan; Garcia-Pelayo, M Carmen; Dale, James; Boschiroli, M Laura; Cadmus, Simeon; Ngandolo, Bongo Naré Richard; Godreuil, Sylvain; Diguimbaye-Djaibé, Colette; Kazwala, Rudovick; Bonfoh, Bassirou; Njanpop-Lafourcade, Betty M; Sahraoui, Naima; Guetarni, Djamel; Aseffa, Abraham; Mekonnen, Meseret H; Razanamparany, Voahangy Rasolofo; Ramarokoto, Herimanana; Djønne, Berit; Oloya, James; Machado, Adelina; Mucavele, Custodia; Skjerve, Eystein; Portaels, Francoise; Rigouts, Leen; Michel, Anita; Müller, Annélle; Källenius, Gunilla; van Helden, Paul D; Hewinson, R Glyn; Zinsstag, Jakob; Gordon, Stephen V; Smith, Noel H

    2009-03-01

    We have identified a clonal complex of Mycobacterium bovis present at high frequency in cattle in population samples from several sub-Saharan west-central African countries. This closely related group of bacteria is defined by a specific chromosomal deletion (RDAf1) and can be identified by the absence of spacer 30 in the standard spoligotype typing scheme. We have named this group of strains the African 1 (Af1) clonal complex and have defined the spoligotype signature of this clonal complex as being the same as the M. bovis BCG vaccine strain but with the deletion of spacer 30. Strains of the Af1 clonal complex were found at high frequency in population samples of M. bovis from cattle in Mali, Cameroon, Nigeria, and Chad, and using a combination of variable-number tandem repeat typing and spoligotyping, we show that the population of M. bovis in each of these countries is distinct, suggesting that the recent mixing of strains between countries is not common in this area of Africa. Strains with the Af1-specific deletion (RDAf1) were not identified in M. bovis isolates from Algeria, Burundi, Ethiopia, Madagascar, Mozambique, South Africa, Tanzania, and Uganda. Furthermore, the spoligotype signature of the Af1 clonal complex has not been identified in population samples of bovine tuberculosis from Europe, Iran, and South America. These observations suggest that the Af1 clonal complex is geographically localized, albeit to several African countries, and we suggest that the dominance of the clonal complex in this region is the result of an original introduction into cows naïve to bovine tuberculosis.

  8. Insecticide resistance in Anopheles gambiae from south-western Chad, Central Africa

    Directory of Open Access Journals (Sweden)

    Etang Josiane

    2008-09-01

    Full Text Available Abstract Background Indoor residual spraying and insecticide-treated nets (ITN are essential components of malaria vector control in Africa. Pyrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. However, there is growing concern that pyrethroid resistance may threaten the sustainability of ITN scaling-up programmes. Here, insecticide susceptibility was investigated in Anopheles gambiae sensu lato from an area of large scale ITN distribution programme in south-western Chad. Methods Susceptibility to 4% DDT, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb and 5% malathion was assessed using the WHO standard procedures for adult mosquitoes. Tests were carried out with two to four days-old, non-engorged female mosquitoes. The An. gambiae Kisumu strain was used as a reference. Knockdown effect was recorded every 5 min and mortality scored 24 h after exposure. Mosquitoes were identified to species and molecular form by PCR-RFLP and genotypes at the kdr locus were determined in surviving specimens by Hot Oligonucleotide Ligation Assay (HOLA. Results During this survey, full susceptibility to malathion was recorded in all samples. Reduced susceptibility to bendiocarb (mortality rate of 96.1% was found in one sample out of nine assayed. Increased tolerance to pyrethroids was detected in most samples (8/9 with mortality rates ranging from 70.2 to 96.6% for deltamethrin and from 26.7 to 96.3% for permethrin. Pyrethroid tolerance was not associated with a significant increase of knock-down times. Anopheles arabiensis was the predominant species of the An. gambiae complex in the study area, representing 75 to 100% of the samples. Screening for kdr mutations detected the L1014F mutation in 88.6% (N = 35 of surviving An. gambiae sensu stricto S form mosquitoes. All surviving An. arabiensis (N = 49 and M form An. gambiae s.s. (N = 1 carried the susceptible allele

  9. "Groundwater ages" of the Lake Chad multi-layer aquifers system inferred from 14C and 36Cl data

    Science.gov (United States)

    Bouchez, Camille; Deschamps, Pierre; Goncalves, Julio; Hamelin, Bruno; Seidel, Jean-Luc; Doumnang, Jean-Claude

    2014-05-01

    Assessment of recharge, paleo-recharge and groundwater residence time of aquifer systems of the Sahel is pivotal for a sustainable management of this vulnerable resource. Due to its stratified aquifer system, the Lake Chad Basin (LCB) offers the opportunity to assess recharge processes over time and to link climate and hydrology in the Sahel. Located in north-central Africa at the fringe between the Sahel and the Sahara, the lake Chad basin (LCB) is an endorheic basin of 2,5.106 km2. With a monsoon climate, the majority of the rainfall occurs in the southern one third of the basin, the Chari/Logone River system transporting about 90% of the runoff generated within the drainage basin. A complex multi-layer aquifer system is located in the central part of the LCB. The Quaternary unconfined aquifer, covering 500 000 km2, is characterized by the occurrence of poorly understood piezometric depressions. Artesian groundwaters are found in the Plio-Pleistocene lacustrine and deltaic sedimentary aquifers (early Pliocene and Continental Terminal). The present-day lake is in hydraulic contact with the Quaternary Aquifer, but during past megalake phases, most of the Quaternary aquifer was submerged and may experience major recharge events. To identify active recharge area and assess groundwater dynamics, one hundred surface and groundwater samples of all layers have been collected over the southern part of the LCB. Major and trace elements have been analyzed. Measurements of 36Cl have been carried out at CEREGE, on the French 5 MV AMS National Facility ASTER and 14C activities have been analyzed for 17 samples on the French AMS ARTEMIS. Additionally, the stable isotopic composition was measured on the artesian aquifer samples. In the Quaternary aquifer, results show a large scatter with waters having very different isotopic and geochemical signature. In its southern part and in the vicinity of the surface waters, groundwaters are predominantly Ca-Mg-HCO3 type waters with very

  10. Possible Role of Fish and Frogs as Paratenic Hosts of Dracunculus medinensis, Chad

    Science.gov (United States)

    Yabsley, Michael J.; Zirimwabagabo, Hubert; Bishop, Henry; Cleveland, Christopher A.; Maerz, John C.; Bringolf, Robert; Ruiz-Tiben, Ernesto

    2016-01-01

    Copepods infected with Dracunculus medinensis larvae collected from infected dogs in Chad were fed to 2 species of fish and tadpoles. Although they readily ingested copepods, neither species of fish, Nile tilapia (Oreochromis niloticus) nor fathead minnow (Pimephalis promelas), were found to harbor Dracunculus larvae when examined 2–3 weeks later. Tadpoles ingested copepods much more slowly; however, upon examination at the same time interval, tadpoles of green frogs (Lithobates [Rana] clamitans) were found to harbor small numbers of Dracunculus larvae. Two ferrets (Mustela putorius furo) were fed fish or tadpoles that had been exposed to infected copepods. Only the ferret fed tadpoles harbored developing Dracunculus larvae at necropsy 70–80 days postexposure. These observations confirm that D. medinensis, like other species in the genus Dracunculus, can readily survive and remain infective in potential paratenic hosts, especially tadpoles. PMID:27434418

  11. Mixture model of pottery decorations from Lake Chad Basin archaeological sites reveals ancient segregation patterns.

    Science.gov (United States)

    O'Brien, John D; Lin, Kathryn; MacEachern, Scott

    2016-03-30

    We present a new statistical approach to analysing an extremely common archaeological data type--potsherds--that infers the structure of cultural relationships across a set of excavation units (EUs). This method, applied to data from a set of complex, culturally heterogeneous sites around the Mandara mountains in the Lake Chad Basin, helps elucidate cultural succession through the Neolithic and Iron Age. We show how the approach can be integrated with radiocarbon dates to provide detailed portraits of cultural dynamics and deposition patterns within single EUs. In this context, the analysis supports ancient cultural segregation analogous to historical ethnolinguistic patterning in the region. We conclude with a discussion of the many possible model extensions using other archaeological data types.

  12. Predictive value of CHADS2 score and modified CHADS score for reoccurrence of atrial fibrillation after radiofrequency catheter ablation%CHADS2评分及改良CHADS评分对心房颤动消融术后复发的预测价值

    Institute of Scientific and Technical Information of China (English)

    王松云; 江洪; 鲁志兵; 余锂镭; 黄兵; 王卓; 何文博; 廖凯; 萨仁高娃; 阳康

    2014-01-01

    目的:探讨心力衰竭高血压、年龄、糖尿病和脑卒中(包括一过性脑缺血)(CHADS2)评分及改良CHADS评分对心房颤动(房颤)射频消融术后复发的预测价值。方法对2010年7月至2012年3月在我院行射频消融术的93例房颤患者追踪随访12个月,术后1,3,6,9,12个月行12导联心电图或长程心电图检查,结合临床症状及心电图检查结果将其分为复发组(n=40)和未复发组(n=53),采用单因素和多因素分析消融术后房颤复发的危险因素。结果93例房颤患者中持续性房颤35例(37.63%),随访12个月时复发40例(43.01%)。房颤复发组与未复发组在平均年龄(P<0.01)、年龄>70岁(P<0.05)、病史(P<0.05)、房颤类型(P<0.01)、左房内径(P<0.001)、左室射血分数(P<0.05)、血细胞比容(P<0.05)、是否伴心力衰竭(P<0.05)、是否伴高血压(P<0.01)、是否伴糖尿病(P<0.05)、是否有一过性脑缺血或脑卒中史(P<0.05)、术后是否服用血管紧张素转换酶抑制剂和血管紧张素Ⅱ受体拮抗剂(ACEI/ARB,P<0.01)、术后是否服用Ⅲ类抗心律失常药(P<0.05)、CHADS2评分≥1(P<0.001)等方面差异有统计学意义。logistic回归分析发现,病史、房颤类型、左房内径、CHADS2评分≥1为房颤术后复发的独立危险因素(病史长短:OR=1.16,P=0.020;左房内径:OR=1.17,P=0.025;房颤类型:OR=3.34,P=0.050;CHADS2评分≥1:OR=5.93,P=0.019)。进一步分析发现,CHADS2评分≥2、改良CHADS评分≥1、改良CHADS评分≥2亦为房颤术后复发的独立危险因素(CHADS2≥2:OR=5.42,P=0.028;改良CHADS评分≥1:OR=6.64,P=0.015;改良CHADS评分≥2:OR=7.32,P=0.002)。截断点分析显示,CHADS2与改良CHADS均≥1时对房颤消融预后的预测价值最高,对CHADS2

  13. Morbidity and nutrition patterns of three nomadic pastoralist communities of Chad.

    Science.gov (United States)

    Schelling, E; Daoud, S; Daugla, D M; Diallo, P; Tanner, M; Zinsstag, J

    2005-07-01

    As a part of an interdisciplinary research and action programme, morbidity and nutritional patterns were assessed in three nomadic communities: Fulani and Arab cattle breeders and Arab camel breeders, of two prefectures in Chad. The predominant morbidity pattern of Chadian nomadic pastoralists (representing approximately 10% of the total population of the country) had not been documented so far. A total of 1092 women, men and children was examined by a physician and interviewed during two surveys in the dry season and one in the wet season (1999--2000). Participants with no complaint were rare. Pulmonary disorders (e.g. bronchitis) were most often diagnosed for children under 5 years of age. Of the adult participants, 4.6% were suspected of tuberculosis. Febrile diarrhoea occurred more often during the wet season when access to clean drinking water was precarious. Malaria was only rarely clinically diagnosed among Arabs during the dry season, whereas Fulani, who stayed in the vicinity of Lake Chad, were also affected during this period. A 24-h dietary recall showed that less Arab women than men consumed milk during the dry season (66% versus 92%). Malnutrition was only documented for 3 out of 328 children (0--14 years). Arab women in childbearing age had a higher proportion of children not surviving when compared to Fulani women (0.2 versus 0.07). This study identified several implications for reseach and interventions in nomadic settings. Innovative and integrated health services for nomads can possibly be extended to many settings as nomadic pastoralists have in common a similar way of life driven by the needs of their animals.

  14. O escore de CHADS2 na predição de eventos cerebrovasculares: uma metanálise

    Directory of Open Access Journals (Sweden)

    Cristina Santos

    2013-03-01

    Full Text Available O escore de CHADS2 é um método de estratificação do risco de eventos cardiovasculares, sendo útil na decisão terapêutica em doentes de moderado/alto risco. Esta metanálise tem como objectivo averiguar se o escore de CHADS2 é eficaz na predição de eventos cerebrovasculares em doentes com Fibrilação Auricular (FA. Realizou-se uma pesquisa bibliográfica informatizada nos motores de busca PubMed, EMBASE e SciELO, durante o período de março de 2011 a abril de 2012. Os estudos foram seleccionados de acordo com critérios predeterminados. A metanálise incidiu em seis estudos de coorte, observacionais e prospectivos, que avaliaram a capacidade preditiva do escore de CHADS2 para eventos cerebrovasculares e morte. Os endpoints definidos (mortalidade e/ou Acidente Vascular Cerebral [AVC] não fatal foram comparados entre doentes com CHADS2 2, e também em função da presença/ausência de FA. No que diz respeito à ocorrência de eventos cardiovasculares combinados, morte e AVC, observou-se um maior risco no grupo com escore de CHADS2 > 2 e com FA crônica, com Odds Ratio (OR respectivamente de 2.92 (IC:2.08-4.10; p 2, independentemente da presença de FA: OR = 2.93 (IC:2.81-3.06; p < 0,00001 nos doentes com FA; OR = 2.94; (IC:2.87-3.01; p < 0,00001 nos doentes sem FA. Os estudos indicam claramente a capacidade discriminativa do escorede CHADS2 para o risco de eventos cerebrovasculares, independentemente da presença ou não de FA, permitindo desta forma identificar doentes de moderado/alto risco e seleccionar estratégias terapêuticas adequadas.

  15. Assessing narcolepsy with cataplexy in children and adolescents: development of a cataplexy diary and the ESS-CHAD

    Science.gov (United States)

    Wang, Y Grace; Benmedjahed, Khadra; Lambert, Jérémy; Evans, Christopher J; Hwang, Steve; Black, Jed; Johns, Murray W

    2017-01-01

    Objective The aim of this study was to qualitatively evaluate concepts for incorporation into a daily diary to capture cataplexy frequency and to assess the content validity of the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) in pediatric patients with narcolepsy. Patients and methods Face-to-face concept elicitation and cognitive interviews were conducted with children (7–9 years; n=13) and adolescents (10–17 years; n=16) who have narcolepsy with cataplexy, and their parents/caregivers. Results Similarities and differences were noted between narcolepsy concepts described by children and their parents/caregivers, suggesting some different but complementary perspectives; parents may not recognize cataplexy symptoms/triggers as well as children, but parents have greater recognition of the circumstances of falling asleep. Cataplexy diary modifications included changes in definitions and examples of cataplexy, using child-friendly terminology, adding a quantitative question to determine daily frequency, and standardizing the questionnaire for evening administration with self-completion by the child. Modifications were made to ESS-CHAD for child-friendly wording and to ensure that items reflect activities (eating, watching TV/video) and environments (school, bus/car transport) in which children are likely to participate. Two ESS-CHAD versions were proposed: one with a 1-month recall period, for general use, and the other with a recall period of “since your last study visit,” for research, which could be shorter or longer than 1 month (as short as 1 week). Conclusion The cataplexy diary and ESS-CHAD were modified for the assessment of children and adolescents. Further psychometric validation is recommended. These measures are being used in a Phase III, placebo-controlled clinical trial of sodium oxybate in children and adolescents with narcolepsy. PMID:28860883

  16. Bacillus anthracis Diversity and Geographic Potential across Nigeria, Cameroon and Chad: Further Support of a Novel West African Lineage

    OpenAIRE

    2015-01-01

    Zoonoses, diseases affecting both humans and animals, can exert tremendous pressures on human and veterinary health systems, particularly in resource limited countries. Anthrax is one such zoonosis of concern and is a disease requiring greater public health attention in Nigeria. Here we describe the genetic diversity of Bacillus anthracis in Nigeria and compare it to Chad, Cameroon and a broader global dataset based on the multiple locus variable number tandem repeat (MLVA-25) genetic typing ...

  17. [Cost estimation of an epidemiological surveillance network for animal diseases in Central Africa: a case study of the Chad network].

    Science.gov (United States)

    Ouagal, M; Berkvens, D; Hendrikx, P; Fecher-Bourgeois, F; Saegerman, C

    2012-12-01

    In sub-Saharan Africa, most epidemiological surveillance networks for animal diseases were temporarily funded by foreign aid. It should be possible for national public funds to ensure the sustainability of such decision support tools. Taking the epidemiological surveillance network for animal diseases in Chad (REPIMAT) as an example, this study aims to estimate the network's cost by identifying the various costs and expenditures for each level of intervention. The network cost was estimated on the basis of an analysis of the operational organisation of REPIMAT, additional data collected in surveys and interviews with network field workers and a market price listing for Chad. These costs were then compared with those of other epidemiological surveillance networks in West Africa. The study results indicate that REPIMAT costs account for 3% of the State budget allocated to the Ministry of Livestock. In Chad in general, as in other West African countries, fixed costs outweigh variable costs at every level of intervention. The cost of surveillance principally depends on what is needed for surveillance at the local level (monitoring stations) and at the intermediate level (official livestock sectors and regional livestock delegations) and on the cost of the necessary equipment. In African countries, the cost of surveillance per square kilometre depends on livestock density.

  18. Anticoagulation Stability Depends on CHADS2 Score and Hepatorenal Function in Warfarin-treated Patients, Including Those with Atrial Fibrillation

    Science.gov (United States)

    Odashiro, Keita; Fukata, Mitsuhiro; Arita, Takeshi; Maruyama, Toru; Akashi, Koichi

    2017-01-01

    Aim: Although warfarin remains important despite the widespread use of nonvitamin K antagonist oral anticoagulants (NOACs), to date, the reality of warfarin use in the “NOACs era” is unclear. This multicenter observational study aimed to clarify the key factors contributing to warfarin treatment stability. Methods: The practical use of warfarin, stability of warfarin therapy, and factors contributing to this stability were investigated in community-based hospitals through a real-world study. Clinical data were retrospectively extracted from the medical records of warfarin-treated Japanese patients (age, 71.3 ± 5.5 years) with atrial fibrillation (AF), prosthetic heart valve, or other concerns requiring anticoagulation. Treatment stability was considered as time in therapeutic range of international normalized ratio of prothrombin time (TTR: %). The factors contributing to TTR were investigated, including CHADS2 score components. Results: Mean CHADS2 score was highest (1.38 ± 0.88, p antiplatelet agents did not correlate with the low TTR. Conclusions: This retrospective study demonstrated that the CHADS2 score component accumulation and hepatorenal dysfunction are factors significantly contributing to the low TTR, which is indicative of poor warfarin treatment stability, in patients such as those with AF. PMID:27319745

  19. ["Democracy is a universal value". Interview with S.E.M. Nassour Ouaidou Guelengdouksia, Prime Minister of Chad].

    Science.gov (United States)

    Ngata, S

    1999-12-01

    Democracy and development are fashionable concepts currently being cited by politicians and organizations involved in promoting development. However, Chad¿s Prime Minister believes that it was necessary for his country to have a one-party government during 1962-75 to better facilitate the nation-building process. He also believes that the concept of democracy refers to the power of the people. Being free to express themselves, the people can censure the actions of their elected government. Far from being reserved for only a selected group of people or countries, democracy has universal vale and appeal. While African populations retain their traditional values, it does not mean that democracy is a luxury phenomenon for the continent. It simply means that prevailing values must be adapted over time. As for democracy in Chad, a multiparty state was created Order 15, enacted at the end of 1991. The first parties then began to form in 1992, and Chad now boasts almost 70 political parties and about 600 civic organizations. The population freely expresses itself and the mass media maintain a free hand to communicate regardless of what they say. Development can be defined as the occurrence of qualitative and quantitative changes in a society¿s path of economic progress. However, overall development must also include the human element in order to successfully effect sustainable human development. One must be optimistic about Africa¿s political, democratic, and development future. The processes of economic development and democratic reform can evolve together.

  20. The right to health, health systems development and public health policy challenges in Chad.

    Science.gov (United States)

    Azétsop, Jacquineau; Ochieng, Michael

    2015-02-15

    There is increasing consensus that the right to health can provide ethical, policy and practical groundings for health systems development. The goals of the right to health are congruent with those of health systems development, which are about strengthening health promotion organizations and actions so as to improve public health. The poor shape and performance of health systems in Chad question the extent of realization of the right to health. Due to its comprehensiveness and inclusiveness, the right to health has the potential of being an organizational and a normative backbone for public health policy and practice. It can then be understood and studied as an integral component of health systems development. This paper uses a secondary data analysis of existing documents by the Ministry of Public Health, Institut National de la Statistique, des Etudes Economiques et Démographiques (INSEED), the Ministry of Economy and Agence Française de Cooperation to analyze critically the shape and performance of health systems in Chad based on key concepts and components of the right to health contained in article 12 of the International Covenant on Economic, Social and Cultural Rights, and on General Comment 14. The non-realization of the right to health, even in a consistently progressive manner, raises concerns about the political commitment of state officials to public health, about the justice of social institutions in ensuring social well-being and about individual and public values that shape decision-making processes. Social justice, democratic rule, transparency, accountability and subsidiarity are important groundings for ensuring community participation in public affairs and for monitoring the performance of public institutions. The normative ideals of health systems development are essentially democratic in nature and are rooted in human rights and in ethical principles of human dignity, equality, non-discrimination and social justice. These ideals are grounded

  1. 基于多源遥感数据的非洲乍得湖水面变化监测%Remote sensing analysis on lake area variation of Lake Chad

    Institute of Scientific and Technical Information of China (English)

    刘甜甜; 刘荣高; 葛全胜

    2013-01-01

    Lake Chad,on the border of the Sahara desert in central Africa,is well known for its high sensitivity to hydroclimatic events.Over the last 40 years,Lake Chad,once the sixth largest lake in the world,has shrunk by more than 90% in area.In this paper,variations of the open water areas,extracted from multi-source remote sensing data during 1973-2012,are analyzed.The results showed that in general Lake Chad was getting smaller and smaller during 1973-2012.Between 1973 and 1975 its area sharply reduced by about 71%.From then on its area ranges from 2000 km2 to 5000 km2.In order to validate the reliability of the trends,this paper first compares it with Birkett's results to analyze area accuracy,and next compares the results of MODIS with Landsat and AVHRR to validate the comparability of multi-source data,and last monitors monthly variation of Lake Chad area to validate the feasibility of multi-temporal data.Meteorological data analysis showed that the area of Lake Chad and the fluctuation of annual precipitation were in good correlation.Secondly,a large number of reservoirs built are another important cause of area reduction.Lastly,the Great Barrier that divided the lake into two smaller lakes has made it more vulnerable to water loss.%乍得湖位于中非撒哈拉沙漠边界,是非洲重要的淡水湖,湖面大小对气候变化高度敏感.近40年,由于干旱等自然灾害和大规模灌溉等人为因素的影响,乍得湖面积急剧减少,受到广泛关注.本文利用多种光学遥感数据提取1973-2012年乍得湖面积,分析其变化趋势和驱动机制.结果表明,1973-2012年间乍得湖面积总体上在变小,1973-1975年间乍得湖面积急剧减少了约71%,1975-2012年面积在2000~5000km2范围内波动.为验证变化趋势的可靠性,本文利用MODIS影像与同期Landsat和AVHRR影像的提取结果进行比较,来检验多源数据的可比性;通过MODIS影像监测乍得湖面积的月变化,来检验所选数

  2. Actinomadura gamaensis sp. nov., a novel actinomycete isolated from soil in Gama, Chad.

    Science.gov (United States)

    Abagana, Adam Yacoub; Sun, Pengyu; Liu, Chongxi; Cao, Tingting; Zheng, Weiwei; Zhao, Shanshan; Xiang, Wensheng; Wang, Xiangjing

    2016-06-01

    A novel single spore-producing actinomycete, designated strain NEAU-Gz5(T), was isolated from a soil sample from Gama, Chad. A polyphasic taxonomic study was carried out to establish the status of this strain. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, mannose and madurose occur in whole cell hydrolysates. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified glycolipid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6). The predominant cellular fatty acids were found to be C16:0, iso-C15:0, iso-C16:0 and C18:0 10-methyl. Phylogenetic analysis based on the 16S rRNA gene showed that strain NEAU-Gz5(T) belongs to the genus Actinomadura and is closely related to Actinomadura oligospora JCM 10648(T) (ATCC 43269(T); 98.3 % similarity). However, the low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain NEAU-Gz5(T) represents a novel species of the genus of Actinomadura, for which the name Actinomadura gamaensis sp. nov. is proposed. The type strain is NEAU-Gz5(T) (= CGMCC 4.7301(T) = DSM 100815(T)).

  3. Continuation of Health Behaviors: Psychosocial Factors Sustaining Drinking Water Chlorination in a Longitudinal Study from Chad

    Directory of Open Access Journals (Sweden)

    Jonathan Lilje

    2016-11-01

    Full Text Available Behavior that has changed following promotion campaigns is usually not maintained at its initial level. Psychosocial factors for initiating behavior are often not the same as for the continuation of health behaviors such as water treatment and are much less understood. Better knowledge of factors for behavioral continuation would help to improve programs, both in the design of strategies for sustainable behavior change and by defining stronger criteria for the evaluation of sustainability. This study compared the mindsets of caregivers who continuously performed household drinking water treatment over time with individuals that stopped doing so in a population sample from Chad. Several factors from health psychology based on the Risks, Attitudes, Norms, Abilities, and Self-Regulation (RANAS model were used to compare the two groups and examine their differing development. Normative factors such as others’ behavior, personal obligation, social support and discourse, perceived self-efficacy convictions, action control, and intention best discriminated between the two groups and developed significantly more positively over time for continuers of water treatment. These factors should be considered when designing future interventions intended to lead to sustainable behavior change.

  4. Assessment of Physical-Chemical Drinking Water Quality in the Logone Valley (Chad-Cameroon

    Directory of Open Access Journals (Sweden)

    Martin B. Ngassoum

    2013-07-01

    Full Text Available Unsafe drinking water is one of the main concerns in developing countries. In order to deal with this problem, a cooperation project was set up by the ACRA Foundation in the Logone valley (Chad-Cameroon. Water supplies were sampled throughout the villages of this area mostly from boreholes, open wells, rivers and lakes as well as some piped waters. The samples were analysed for their physical-chemical and microbiological quality in order to identify the contamination problems and suggest appropriate solutions. Results of the assessment confirmed that in the studied area there are several parameters of health and aesthetic concern. Elevated lead levels were detected both in aquifers and in surface waters, confirming that further investigations of the occurrence of lead contamination in the Logone valley are warranted. In addition, many groundwater sources are negatively impacted by parameters of aesthetic concern, such as turbidity, iron and manganese. Even though they do not affect human health, elevated levels of these parameters cause consumers to abandon improved water supplies, often in favour of surface water sources that are microbiologically contaminated. The use of alternative sources, improvement of water supply structures and water treatment are possible solutions to improve the quality of drinking water in the Logone valley.

  5. Downscaling precipitation in the Sahara-Sahelian region during the Holocene in order to decipher the paleo-variations of Lake Chad

    Science.gov (United States)

    Contoux, Camille; Bondeau, Alberte; Barrier, Nicolas; Sylvestre, Florence

    2016-04-01

    In order to understand the paleo-variability of Saharo-Sahelian paleoprecipitation, which is recorded in the sediments of Lake Chad situated in central Sahel, we use a modelling chain going from global climate to basin-scale hydrological model. Namely, climate model outputs for the Holocene, starting with the mid-Holocene (6ka) available from the IPSL-CM5 global climate model are statistically downscaled with the General Additive Model approach (Levavasseur et al., 2011), then used to feed the LPJmL model (Bondeau et al., 2007) which calculates the equilibrium vegetation and runoff. Climate and runoff are then given to the dynamic routing scheme HYDRA (Coe et al., 2000) in order to calculate the paleo river network and paleo extent of Lake Chad. The results at each step are compared with reconstructions derived from continental proxies on the regional scale in order to assess the robustness of the results. For the mid-Holocene, the downscaled precipitation matches very well precipitation estimations derived from lacustrine pollen data. For the historical period, the LPJmL simulated runoff averaged over the Chad basin depicts the same trend than observations of Lake Chad water level, but the absolute water level is overestimated in HYDRA, which can be attributed to humid biases both in LPJmL and HYDRA. Finally, we will investigate the relative changes in river network and Lake Chad extent between the present and the mid-Holocene.

  6. Effects of Land Cover / Land Use, Soil Texture, and Vegetation on the Water Balance of Lake Chad Basin

    Science.gov (United States)

    Babamaaji, R. A.; Lee, J.

    2013-12-01

    Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the effects of land use / land cover must be a first step to find how they disturb cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and disuse recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires reliable forecasting of changes in the major climatic variables and other spatial variations including the land use/land cover, soil texture, topographic slope, and vegetation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal and spatial distribution of surface runoff, interception, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB. The study shows that major role in the water balance of LCB. The mean yearly actual evapotranspiration (ET) from the basin range from 60mm - 400 mm, which is 90 % (69mm - 430) of the annual precipitation from 2003 - 2010. It is striking that about 50 - 60 % of the total runoff is produced on build-up (impervious surfaces), while much smaller contributions are obtained from vegetated

  7. Malnutrition and mortality patterns among internally displaced and non-displaced population living in a camp, a village or a town in Eastern Chad.

    Directory of Open Access Journals (Sweden)

    Gilles Guerrier

    Full Text Available BACKGROUND: Certain population groups have been rendered vulnerable in Chad because of displacement of more than 200,000 people over the last three years as a result of mass violence against civilians in the east of the country. The objective of the study was to assess mortality and nutritional patterns among displaced and non-displaced population living in camps, villages and a town in the Ouddaï and Salamat regions of Chad. METHODOLOGY: Between May and October 2007, two stage, 30-cluster household surveys were conducted among 43,900 internally displaced persons (IDPs living in camps in Ouaddai region (n = 898 households, among 19,400 non-displaced persons (NDPs living in 42 villages in Ouaddai region (n = 900 households and among 17,000 NDPs living in a small town in Salamat region (n = 901 households. Data collection included anthropometric measurements, measles vaccination rates and retrospective mortality. Crude mortality rate (CMR, mortality rate among children younger than 5 years (U5MR, causes of death and the prevalence of wasting (weight-for-height z score <-2 among children aged 6 to 59 months were the main outcome measures. CONCLUSIONS: The CMR among the 4902 IDPs in Gozbeida camps, 4477 NDPs living in a village and 4073 NDPs living in a town surveyed was 1.8 (95% CI, 1.2-2.8, 0.3 (95% CI, 0.2-0.4, 0.3 (95% CI, 0.2-0.5 per 10,000 per day, respectively. The U5MR in a camp (n = 904, a village (n = 956 and a town (n = 901 was 4.1 (95% CI, 2.1-7.7, 0.5 (95% CI, 0.3-0.9 and 0.7 (95% CI, 0.4-1.4 per 10,000 per day, respectively. Diarrhoea was reported to be the main cause of death. Acute malnutrition rates (according to the WHO definition among 904 IDP children, 956 NDPs children living in a village, 901 NDP children living in a town aged 6 to 59 months were 20.6% (95% CI, 17.9%-23.3%, 16.4% (95% CI, 14.0%-18.8% and 10.1% (95% CI, 8.1%-12.2% respectively. The study found a high mortality rate among IDPs and an elevated prevalence of

  8. Who Benefits from Public Social Spending in Chad? A Benefit Incidence Analysis (A qui profitent les dépenses sociales au Tchad? Une analyse d'incidence à partir des données d'enquête

    NARCIS (Netherlands)

    Djindil, N.S.; Tabo Symphorien, N.; Mogota Anatole, T.

    2007-01-01

    This study examines the impact of public expenditures in the sector of education and maternal and child health in household level in Chad. The results show that there exist a very strong social selectivity in the utilisation and transfer of health and education in Chad. The analysis reveals that an

  9. The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modelin

    Science.gov (United States)

    Voss, Clifford I.; Soliman, Safaa M.

    2014-01-01

    Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world’s largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.

  10. The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling

    Science.gov (United States)

    Voss, Clifford I.; Soliman, Safaa M.

    2014-03-01

    Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world's largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.

  11. Biomass burning and its relationship with water cycle dynamics of the Chari-Logone catchment of Lake Chad Basin

    Science.gov (United States)

    Black, F. W.; Lee, J.; Ellison, L.; Gupta, M.; Bolten, J. D.; Gatebe, C. K.; Ichoku, C. M.

    2016-12-01

    The cause of shrinkage of Lake Chad has been of great interest for issues of global warming and climate change. The present study investigates the effect of biomass burning on the water cycle dynamics of Lake Chad Basin in the Northern Sub-Saharan Africa. Burning activities increase from November to April when monsoonal precipitation is at its lowest and decreases dramatically from May to October when precipitation peaks. To circumvent weather station scarcity in the region, a variety of satellite products were used as input into a water balance model. The datasets include TRMM 3B31 for precipitation, SRTM for elevation, and MODIS: MOD11C3 for temperature, MOD12Q1 for land cover, and MOD14A for fire count. Non-satellite based data sources include soil maps from the Harmonized World Soil Database and wind speed from NOAA NCDC stations. The Chari-Logone catchment of the Lake Chad Basin was selected since it supplies over 90% of the water input to the Lake. Fire count data from MOD14A were integrated with land cover albedo changes to determine monthly potential evapotranspiration (PET) using a Penman equation. The resolution of the model is 2 km x 2 km which allows for delineation of physical features such as lakes and other water bodies. Fire counts, also at a resolution of 2 km x 2 km, vary dramatically depending on the season. A separate land cover dataset was created to account for the effect of burning of different vegetative land types, which affects vegetative area, bare area, leaf area index, vegetation height, Manning coefficient, and aerodynamic resistance. Two water balance simulations, one considering burning and one without, were compared from the years 2005 to 2010. Results indicate biomass burning contribute to an increase in average monthly runoff and a decrease in groundwater recharge. Actual evapotranspiration shows variation depending on the month.

  12. Late Cretaceous intraplate silicic volcanic rocks from the Lake Chad region: An extension of the Cameroon volcanic line?

    Science.gov (United States)

    Shellnutt, J. G.; Lee, T.-Y.; Torng, P.-K.; Yang, C.-C.; Lee, Y.-H.

    2016-07-01

    Silicic volcanic rocks at Hadjer el Khamis, near Lake Chad, are considered to be an extension of the Cameroon volcanic line (CVL) but their petrogenetic association is uncertain. The silicic rocks are divided into peraluminous and peralkaline groups with both rock types chemically similar to within-plate granitoids. In situ U/Pb zircon dating yielded a mean 206Pb/238U age of 74.4 ± 1.3 Ma indicating the magmas erupted ˜10 million years before the next oldest CVL rocks (i.e., ˜66 Ma). The Sr isotopes (i.e., ISr = 0.7021-0.7037) show a relatively wide range but the Nd isotopes (i.e., 143Nd/144Ndi = 0.51268-0.51271) are uniform and indicate that the rocks were derived from a moderately depleted mantle source. Thermodynamic modeling shows that the silicic rocks likely formed by fractional crystallization of a mafic parental magma but that the peraluminous rocks were affected by low temperature alteration processes. The silicic rocks are more isotopically similar to Late Cretaceous basalts identified within the Late Cretaceous basins (i.e., 143Nd/144Ndi = 0.51245-0.51285) of Chad than the uncontaminated CVL rocks (i.e., 143Nd/144Ndi = 0.51270-0.51300). The age and isotopic compositions suggest the silicic volcanic rocks of the Lake Chad region are related to Late Cretaceous extensional volcanism in the Termit basin. It is unlikely that the silicic volcanic rocks are petrogenetically related to the CVL but it is possible that magmatism was structurally controlled by suture zones that formed during the opening of the Central Atlantic Ocean and/or the Pan-African Orogeny.

  13. Phytoliths indicate significant arboreal cover at Sahelanthropus type locality TM266 in northern Chad and a decrease in later sites.

    Science.gov (United States)

    Novello, Alice; Barboni, Doris; Sylvestre, Florence; Lebatard, Anne-Elisabeth; Paillès, Christine; Bourlès, Didier L; Likius, Andossa; Mackaye, Hassane Taisso; Vignaud, Patrick; Brunet, Michel

    2017-05-01

    We analyzed phytolith and diatom remains preserved at 45 Miocene and Pliocene localities dated between 8 and 1 Ma in northern Chad (16-17°N). Some of these localities yielded cranial remains, lower jaws, and teeth of the hominin species Australopithecus bahrelghazali (∼3.6 Ma) and Sahelanthropus tchadensis (∼7 Ma). Of the 111 sediment samples analyzed, 41 yielded phytoliths, 20 yielded diatoms, and seven yielded both phytoliths and diatoms. Freshwater planktonic and tychoplanktonic diatom species, indicative of lacustrine conditions, are dominant (>91%) in the samples. The phytolith assemblages indicate an opening of the vegetation and a general trend toward an expansion of grass-dominated environments during the time spanning the two hominin occurrences in Chad. The phytoliths suggest the presence of a mosaic environment, including closed forest patches, palm groves, and mixed/grassland formations, between 7.5 and 7 Ma, the replacement by palm grove-like vegetation at approximately 6.5-5 Ma, and the presence of exclusive grass-dominated formations after 4.5 Ma. The type-locality of S. tchadensis (TM266) was likely similar to modern palm grove formations with an arboreal cover percentage ≥40%. The type locality of A. bahrelghazali (KT12) was a grass-dominated ecosystem (likely savanna) with an unrated percentage of arboreal cover. Furthermore, the grass phytolith data support the existence of a (recurrent) Sahelian-like dry climate in northern Chad since at least 8 Ma. Therefore the local closed vegetation formations in the Djurab region at 7.5-7 Ma were sustained by aquatic systems (such as lakes or related rivers, marshes) rather than by extensive annual precipitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Impact of the Megalake Chad on climate and vegetation during the late Pliocene and the mid-Holocene

    Directory of Open Access Journals (Sweden)

    C. Contoux

    2013-03-01

    Full Text Available Given the growing evidence for megalakes in the geological record, assessing their impact on climate and vegetation is important for the validation of paleoclimate simulations and therefore the accuracy of model/data comparison in lacustrine environments. Megalake Chad (MLC occurrences are documented for the mid-Holocene but also for the Mio-Pliocene (Schuster et al., 2009. The surface covered by water would have reached up to ~350 000 km2 (Ghienne et al., 2002; Schuster et al., 2005; Leblanc et al., 2006 making it an important evaporation source, possibly modifying the climate and vegetation in the Chad basin. We investigated the impact of such a giant continental water area in two different climatic backgrounds within the Paleoclimate Model Intercomparison Project phase 3 (PMIP3: the late Pliocene (3.3 to 3 Ma, i.e. the mid-Piacenzian warm period and the mid-Holocene (6 kyr BP. In all simulations including a MLC, precipitation is drastically reduced above the lake surface because deep convection is inhibited by colder air above the lake surface. Meanwhile, convective activity is enhanced around the MLC, because of the wind increase generated by the flat surface of the megalake, transporting colder and moister air towards the eastern shore of the lake. Effect of the MLC on precipitation and temperature is not sufficient to widely impact vegetation patterns. Nevertheless, tropical savanna is present in the Chad Basin in all climatic configurations, even without the MLC presence, showing that the climate itself is the driver of favourable environments for sustainable hominid habitats.

  15. Assessing narcolepsy with cataplexy in children and adolescents: development of a cataplexy diary and the ESS-CHAD

    Directory of Open Access Journals (Sweden)

    Wang YG

    2017-08-01

    Full Text Available Y Grace Wang,1 Khadra Benmedjahed,2 Jérémy Lambert,2 Christopher J Evans,3 Steve Hwang,3 Jed Black,1,4 Murray W Johns5 1Clinical Development, Jazz Pharmaceuticals, Palo Alto, CA, USA; 2Patient-Centered Outcomes, Mapi, Lyon, France; 3Endpoint Outcomes, Boston, MA, USA; 4Sleep Medicine, Stanford Sleep Medicine Center, Redwood City, CA, USA; 5Epworth Sleep Centre, East Melbourne, VIC, Australia Objective: The aim of this study was to qualitatively evaluate concepts for incorporation into a daily diary to capture cataplexy frequency and to assess the content validity of the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD in pediatric patients with narcolepsy.Patients and methods: Face-to-face concept elicitation and cognitive interviews were conducted with children (7–9 years; n=13 and adolescents (10–17 years; n=16 who have narcolepsy with cataplexy, and their parents/caregivers.Results: Similarities and differences were noted between narcolepsy concepts described by children and their parents/caregivers, suggesting some different but complementary perspectives; parents may not recognize cataplexy symptoms/triggers as well as children, but parents have greater recognition of the circumstances of falling asleep. Cataplexy diary modifications included changes in definitions and examples of cataplexy, using child-friendly terminology, adding a quantitative question to determine daily frequency, and standardizing the questionnaire for evening administration with self-completion by the child. Modifications were made to ESS-CHAD for child-friendly wording and to ensure that items reflect activities (eating, watching TV/video and environments (school, bus/car transport in which children are likely to participate. Two ESS-CHAD versions were proposed: one with a 1-month recall period, for general use, and the other with a recall period of “since your last study visit,” for research, which could be shorter or longer than 1 month

  16. CHADS(2) and CHA(2)DS (2)-VASc score of patients with atrial fibrillation or flutter and newly detected left atrial thrombus.

    Science.gov (United States)

    Wasmer, Kristina; Köbe, Julia; Dechering, Dirk; Milberg, Peter; Pott, Christian; Vogler, Julia; Stypmann, Jörg; Waltenberger, Johannes; Mönnig, Gerold; Breithardt, Günter; Eckardt, Lars

    2013-02-01

    The risk of developing a stroke or systemic embolus due to a left atrial (LA) thrombus in patients with atrial fibrillation (AF) and/or atrial flutter (AFL) is estimated by the CHADS(2) score and more recently the CHA(2)DS(2)-VASc score. We aimed to further characterize AF/AFL patients who were found to have a LA thrombus on a transesophageal echocardiogram (TEE). Of 3,165 TEE between 2005 and 2011 for a broad spectrum of indications, we detected 65 AF patients with LA thrombus (2 %). There were 40 men and 25 women, mean age was 65 ± 13 years (range 36-88 years). Mean CHADS(2) score was 1.8 ± 1.1 and mean CHA(2)DS(2)-VASc score was 3.0 ± 1.6. 11 patients (17 %) had a CHADS(2) score of 0, 12 patients (18 %) of 1, 28 patients (43 %) of 2 and 12 patients (18 %) of 3. Hypertension was the most frequent risk factor (72 %), followed by congestive heart failure (32 %), diabetes (23 %) and age ≥75 years (23 %). Mean difference between CHADS(2) and CHA(2)DS(2)-VASc was 1.25 ± 0.91. Of the 11 patients (17 %) with a LA thrombus despite a CHADS(2) score of 0, five had a CHA(2)DS(2)-VASc score of 0, four a CHA(2)DS(2)-VASc score of 1 and two a CHA(2)DS(2)-VASc score of 2. In an unselected TEE population with newly detected LA thrombus about one-third of patients fell into the low-risk group when classified based on the CHADS(2) score, while a much lower population fell in the same low-risk group when classified according to the CHA(2)DS(2)-VASc score. However, this does not prove clinical superiority of the CHA(2)DS(2)-VASc score over the established CHADS(2) score. Whether our observation has clinical implications (e.g. TEE prior to LA ablation irrespective of CHADS(2) score), or argues for use of the CHA(2)DS(2)-VASc score needs to be evaluated in prospective studies.

  17. Water balance-based estimation of groundwater recharge in the Lake Chad Basin

    Science.gov (United States)

    Babamaaji, R. A.; Lee, J.

    2012-12-01

    Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought and shortage of water has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the change of land use and its characteristics must be a first step to find how such changes disturb the water cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and vertical recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires not only reliable forecasting of changes in the major climatic variables, but also accurate estimation of groundwater recharge. Spatial variations in the land use/land cover, soil texture, topographic slope, and meteorological conditions should be accounted for in the recharge estimation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal average spatial distribution of surface runoff, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB.

  18. The impact of the Good Behavior Game, a universal classroom-based preventive intervention in first and second grades, on high-risk sexual behaviors and drug abuse and dependence disorders into young adulthood.

    Science.gov (United States)

    Kellam, Sheppard G; Wang, Wei; Mackenzie, Amelia C L; Brown, C Hendricks; Ompad, Danielle C; Or, Flora; Ialongo, Nicholas S; Poduska, Jeanne M; Windham, Amy

    2014-02-01

    The Good Behavior Game (GBG), a method of teacher classroom behavior management, was tested in first- and second-grade classrooms in 19 Baltimore City Public Schools beginning in the 1985-1986 school year. The intervention was directed at the classroom as a whole to socialize children to the student role and reduce aggressive, disruptive behaviors, confirmed antecedents of a profile of externalizing problem outcomes. This article reports on the GBG impact on the courses and interrelationships among aggressive, disruptive behavior through middle school, risky sexual behaviors, and drug abuse and dependence disorders through ages 19-21. In five poor to lower-middle class, mainly African American urban areas, classrooms within matched schools were assigned randomly to either the GBG intervention or the control condition. Balanced assignment of children to classrooms was made, and teachers were randomly assigned to intervention or control. Analyses involved multilevel growth mixture modeling. By young adulthood, significant GBG impact was found in terms of reduced high-risk sexual behaviors and drug abuse and dependence disorders among males who in first grade and through middle school were more aggressive, disruptive. A replication with the next cohort of first-grade children with the same teachers occurred during the following school year, but with minimal teacher mentoring and monitoring. Findings were not significant but generally in the predicted direction. A universal classroom-based prevention intervention in first- and second-grade classrooms can reduce drug abuse and dependence disorders and risky sexual behaviors.

  19. Study of Standardized Anticoagulant Therapy in Elderly Patient with Atrial Fibrillation%CHADS2评分法规范老年非瓣膜性房颤治疗研究

    Institute of Scientific and Technical Information of China (English)

    孙荣艳; 范正俊; 冯云萍; 浩一竹

    2015-01-01

    Objective:To understand current the state of standardized anticoagulant therapy.In elderly patient with atrial fibrillation and analyze the factors that affect standard anticoagulant therapy,and at the same time,to make progress by the foundation of corresponding countermeasures.Method:Diagnosed nonvalvular atrial fibrillation elderly patients were history inspected for a period of 12 months(from January 2013 to December 2013)in 1st Hospital Cardiovascular Department,CHADS2 scheme method was used to stratify atrial fibrillation elderly patient and assess their risk of bleeding,the standardized anticoagulant therapy conditions were evaluated according to atrial fibrillation treatment guidelines.Result:A total of 161 patients were enrolled.According to the CHADS2 scheme,106 patients were divided into the high risk group,in which only 21 were on warfarin anticoagulant treatment.Among which 11(42.3%) had international normalized ratio(INR)in therapeutic range(2.0-3.0).Conclusion:The percentage of standard anticoagulant treatment in elderly patients with atrial fibrillation is very low(38.4%),still more,the percentage of high risk patients using warfarin standard anticoagulant treatment is even low 19.8%.Further investigation and understanding of the causes of this phenomenon will help intervene effectively and improve the standard of anticoagulant therapy in patient with atrial fibrillation.%目的:了解老年非瓣膜性心房颤动患者规范化抗凝治疗现状,分析影响规范化抗凝治疗的因素。方法:调取2013年1-12月份曲靖市第一人民医院住院诊断为非瓣膜性心房颤动的老年患者病历,采用CHADS2评分法评价其规范化抗凝情况。结果:共入选患者161例。按照CHADS2评分法将入组患者分组,其中评分≥1患者151例中,进行规范华法林抗凝治疗的仅26例,抗凝结果11例INR在目标范围内,达到华法林抗凝目标INR值的为42.3%。结论:老年非瓣膜性心房颤

  20. The value of the CHA2DS2-VASc score for refining stroke risk stratification in patients with atrial fibrillation with a CHADS2 score 0-1

    DEFF Research Database (Denmark)

    Olesen, Jonas Bjerring; Torp-Pedersen, Christian; Hansen, Morten Lock

    2012-01-01

    -level-linkage of nationwide Danish registries 1997-2008, we identified patients discharged with AF having a CHADS2 score of 0-1 and not treated with vitamin K antagonist or heparin. In patients with a CHADS2 score of 0, 1, and 0-1, rates of stroke/ thromboembolism were determined according to CHA2DS2-VASc score, and the risk...... associated with increasing CHA2DS2-VASc score was estimated in Cox regression models adjusted for year of inclusion and antiplatelet therapy. The value of adding the extra CHA2DS2-VASc risk factors to the CHADS2 score was evaluated by c-statistics, Net Reclassification Improvement (NRI) and Integrated....... Of the cohort with a CHADS2 score of 0-1, the stroke/thromboembolism rate per 100 person-years increased with increasing CHA2DS2-VASc score (95% confidence interval): 0.84 (0.65-1.08), 1.79 (1.53-2.09), 3.67 (3.34-4.03), 5.75 (5.33-6.21), and 8.18 (6.68-10.02) at one year follow-up with CHA2DS2-VASc scores of 0...

  1. Response of sorghum accessions from Chad and Uganda to natural infection by the downy mildew pathogen, Peronosclerospora sorghi in Mexico and the USA

    Science.gov (United States)

    In this study, 78 accessions from Chad, West Africa and 20 photoperiod insensitive accessions from Uganda, East Africa were evaluated for downy mildew resistance in Ocotlan, Mexico in 2004 and 2005. Ninety-four of these accessions were also evaluated at two locations in Wharton County, Texas, USA, ...

  2. Motion of left atrial appendage as a determinant of thrombus formation in patients with a low CHADS2 score receiving warfarin for persistent nonvalvular atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Ono Koji

    2012-12-01

    Full Text Available Abstract Background The aim of this study was to define the independent determinants of left atrial appendage (LAA thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI in patients with nonvalvular atrial fibrillation (AF receiving warfarin, particularly in patients with a low CHADS2 score. Methods LAA emptying fraction (EF and LAA peak longitudinal strain were measured by VVI using transesophageal echocardiography in 260 consecutive patients with nonvalvular persistent AF receiving warfarin. The patients were divided into two groups according to the presence (n=43 or absence (n=217 of LAA thrombus. Moreover, the patients within each group were further divided into subgroups according to a CHADS2 score ≤1. Results Multivariate logistic regression analysis showed that LAAEF was an independent determinant of LAA thrombus in the subgroup of 140 with a low CHADS2 score. Receiver operating characteristics curve analysis showed that an LAAEF of 21% was the optimal cutoff value for predicting LAA thrombus. Conclusions LAA thrombus formation depended on LAA contractility. AF patients with reduced LAA contractile fraction (LAAEF ≤21% require strong anticoagulant therapy to avoid thromboembolic events regardless of a low CHADS2 score (≤1.

  3. CHADS2 and CHA2DS2-VASc score to assess risk of stroke and death in patients paced for sick sinus syndrome

    DEFF Research Database (Denmark)

    Svendsen, Jesper Hastrup; Nielsen, Jens Cosedis; Darkner, Stine

    2013-01-01

    The risk of stroke in patients with atrial fibrillation (AF) can be assessed by use of the CHADS2 and the CHA2DS2-VASc score system. We hypothesised that these risk scores and their individual components could also be applied to patients paced for sick sinus syndrome (SSS) to evaluate risk of str...

  4. Technical Education and Vocational Training in Central Africa. Feasibility Survey of the Regional Development of Rapid Vocational Training: Cameroon, Central African Republic, Chad, and Gabon.

    Science.gov (United States)

    Organization for Rehabilitation through Training, Geneva (Switzerland).

    This final report is the result of a survey requested by the United States Agency for International Development (USAID) and undertaken by the Organization for Rehabilitation through Training (ORT) of four countries (Cameroon, Chad, Central African Republic, and Gabon) and a conference on vocational training sponsored by the Economic and Customs…

  5. The genetic impact of the lake chad basin population in North Africa as documented by mitochondrial diversity and internal variation of the L3e5 haplogroup.

    Science.gov (United States)

    Podgorná, Eliška; Soares, Pedro; Pereira, Luísa; Cerný, Viktor

    2013-11-01

    The presence of sub-Saharan L-type mtDNA sequences in North Africa has traditionally been explained by the recent slave trade. However, gene flow between sub-Saharan and northern African populations would also have been made possible earlier through the greening of the Sahara resulting from Early Holocene climatic improvement. In this article, we examine human dispersals across the Sahara through the analysis of the sub-Saharan mtDNA haplogroup L3e5, which is not only commonly found in the Lake Chad Basin (∼17%), but which also attains nonnegligible frequencies (∼10%) in some Northwestern African populations. Age estimates point to its origin ∼10 ka, probably directly in the Lake Chad Basin, where the clade occurs across linguistic boundaries. The virtual absence of this specific haplogroup in Daza from Northern Chad and all West African populations suggests that its migration took place elsewhere, perhaps through Northern Niger. Interestingly, independent confirmation of Early Holocene contacts between North Africa and the Lake Chad Basin have been provided by craniofacial data from Central Niger, supporting our suggestion that the Early Holocene offered a suitable climatic window for genetic exchanges between North and sub-Saharan Africa. In view of its younger founder age in North Africa, the discontinuous distribution of L3e5 was probably caused by the Middle Holocene re-expansion of the Sahara desert, disrupting the clade's original continuous spread.

  6. An Arabic-English-French Lexicon of the Dialects Spoken in the Chad-Sudan Area, 1. [Lexique des parlers arabes tchado-soudanais, 1.

    Science.gov (United States)

    Roth-Laly, Arlette, Comp.

    This lexicon, a preliminary publication of a project dealing with Arabic dialects in the Chad-Sudan area, has been compiled from four earlier lexicons: G. Trenga, "Le bura-maband du Ouadai"; H. Carbou, "Methode pratique pour l'etude de l'arabe parle au Ouaday et a l'Est du Tchad"; G.L. Lethem, "Colloquial Arabic, Shua…

  7. Implementation and utilisation of community-based mortality surveillance: a case study from Chad

    Directory of Open Access Journals (Sweden)

    Bowden Sarah

    2012-11-01

    Full Text Available Abstract Background Prospective surveillance is a recognised approach for measuring death rates in humanitarian emergencies. However, there is limited evidence on how such surveillance should optimally be implemented and on how data are actually used by agencies. This case study investigates the implementation and utilisation of mortality surveillance data by Médecins Sans Frontières (MSF in eastern Chad. We aimed to describe and analyse the community-based mortality surveillance system, trends in mortality data and the utilisation of these data to guide MSF’s operational response. Methods The case study included 5 MSF sites including 2 refugee camps and 3 camps for internally displaced persons (IDPs. Data were obtained through key informant interviews and systematic review of MSF operational reports from 2004–2008. Results Mortality data were collected using community health workers (CHWs. Mortality generally decreased progressively. In Farchana and Breidjing refugee camps, crude death rates (CDR decreased from 0.9 deaths per 10,000 person-days in 2004 to 0.2 in 2008 and from 0.7 to 0.1, respectively. In Gassire, Ade and Kerfi IDP camps, CDR decreased from 0.4 to 0.04, 0.3 to 0.04 and 1.0 to 0.3. Death rates among children under 5 years (U5DR followed similar trends. CDR and U5DR crossed emergency thresholds in one site, Kerfi, where CDR rapidly rose to 2.1 and U5DR to 7.9 in July 2008 before rapidly decreasing to below emergency levels by September 2008. Discussion Mortality data were used regularly to monitor population health status and on two occasions as a tool for advocacy. Lessons learned included the need for improved population estimates and standardized reporting procedures for improved data quality and dissemination; the importance of a simple and flexible model for data collection; and greater investment in supervising CHWs. Conclusions This model of community based mortality surveillance can be adapted and used by

  8. The occurrence and transformation of lacustrine sediment gravity flow related to depositional variation and paleoclimate in the Lower Cretaceous Prosopis Formation of the Bongor Basin, Chad

    Science.gov (United States)

    Tan, Mingxuan; Zhu, Xiaomin; Geng, Mingyang; Zhu, Shifa; Liu, Wei

    2017-10-01

    Bed variability of sediment-gravity-flow deposits is quite prevalent in deep-marine settings, but it has not been well investigated in lacustrine settings. The depositional characteristics of various event beds are characterized in the North Slope Belt of the Bongor Basin (Chad), using detailed sedimentological, petrographic, geochemical as well as palynological analysis. Four bed types including classical turbidite bed, debrite bed, hybrid event bed, and hyperpycnite bed were distinguished based on their interpreted depositional processes. Variable mud contents of debrite beds and classic turbidite beds show distinct genetic characteristics in four core wells, whilst the high mud content of cohesive debrite interval and the low mud content of turbidite interval in hybrid event bed demonstrate the existence of flow transformation. Generally, several trace element and rare earth element proxy parameters show that these gravity-flow deposits of BS1-1 and D-3 cores are formed in more distal depositional settings than them of BN8 and BNE3 cores, which is also well consistent with sedimentological understandings achieved by seismic facies analysis. Although palynological results show a general hot arid climate during the deposition of the Prosopis Formation, but the climate-sensitive Sr/Cu ratio demonstrates that most sampled turbidite beds are postulated to be formed within a short humid pulse. The multi-approach analysis has illustrated that two potential forming mechanisms (delta-front-failure and flood-related origin) can be derived in different cored wells of such a small lacustrine rift basin. Differentiated flow transformation plays a significant role in the depositional characteristics and heterogenetic distribution of these event deposits.

  9. Shallow groundwater from the far north of Cameroon (southern Lake Chad): revisiting a 20 years old survey of hydrochemistry and stable isotopes

    Science.gov (United States)

    Ketchemen-Tandia, Beatrice; Mohammad, Bello; Fouepe, Alain; Ngo Boum, Suzanne; Nlend, Bertil; Garel, Emilie; Celle-Jeanton, Helene; Huneau, Frederic

    2016-04-01

    Two field hydrogeological investigation surveys were conducted in 1992 and 2013 using hydrochemistry and isotope techniques in the far north part of Cameroon which corresponds to the southern part of Lake Chad basin. All of these data relate to groundwater and surface water which were collected at the same places to potentially reveal any temporal variation in the chemical and isotopic characteristics of the water resources. Groundwater show mainly a Ca-HCO3 water type but CaMg-Cl and Na-HCO3 water types can also be found. The groundwater chemistry is resulting from many processes including pure silicate weathering and cation exchange. It is found that the nitrate content after 20 years has increased by an average factor of 6. These high concentrations in nitrate (up to 400 mg/l) are related to local anthropogenic activities and to the very bad conditions of maintaining of wells and boreholes. This pollution is also correlated to the population growth over the past two decades in the region. The isotopic content of groundwater is ranging from -6.87‰ to -0.32‰ for δ18O in 2013 and from -6.03‰ to +0.25‰ in 1992 without noticeable evolution through time. The conventional δD-δ18O diagram indicates that the groundwater has a meteoric origin more or less influenced by evaporation processes. Different processes involving different water sources were highlighted: (i) groundwater which has been affected by evaporation or in communication with evaporated surface waters; (ii) groundwater which is very close to the Global Meteoric Water Line and corresponding to a recent and direct recharge from precipitation; (iii) groundwater which is more depleted corresponding to a mixing between shallow and deep groundwater. This research is partly supported by the RAF7012and RAF7011 project from IAEA.

  10. [Nutritional status and dietary diversity in nomadic and sedentary rural women on the southeast bank of Lake Chad].

    Science.gov (United States)

    Bechir, M; Schelling, E; Moto, D D; Tanner, M; Zinsstag, J

    2011-12-01

    Malnutrition and undernourishment are widespread in the Sahelian region of Africa. The purpose of this study was to assess nutritional status and associated risk factors among nomadic and sedentary rural women on the southeast bank of Lake Chad. It was a repeated cross-sectional study based on semi-structured interviews and anthropometric measurements. A total of 734 women including 398 nomads and 336 sedentaries were randomly selected. Only non-pregnant women were included for calculation of the body mass index. Results showed a higher prevalence of malnutrition among nomadic women than sedentary women during the dry season: 48% (95% CI: 42-53) versus 16.2% (95% CI: 12-20). Obesity was observed in 4% (95% CI: 2.4-7) of sedentary women versus 0% of nomadic women. These rates were similar during the wet season. Malnutrition rates differed significantly (pMalnutrition was significantly correlated with HDDS, number of children and ethnic group.

  11. [Seroprevalence of HBs Ag and of anti-HCV antibodies among HIV infected people in N'Djamena, Chad].

    Science.gov (United States)

    Bessimbaye, N; Moussa, A M; Mbanga, D; Tidjani, A; Mahamat, S O; Ngawara, M Nahor; Ngarnayal, G; Fissou, H Y; Sangare, L; Ndoutamia, G; Barro, N

    2014-12-01

    This is a prospective study conducted as part of a voluntary testing for HBV, HCV and HIV. The aim of the study is to determine the seroprevalence of HBs Ag and anti-HCV antibodies among HIV infected people and a control group of HIV negative people. HIV prevalence among newly diagnosed volunteers is 9.1%. The overall seroprevalence of HBs Ag and anti-HCV antibodies is respectively 13.5% and 2.0%. The seroprevalence of HBs Ag and anti-HCVantibodies in the control group (HIV-negative) is respectively 12.2% and 2%. The seroprevalence of HBs Ag and anti-HCV antibodies among HIV infected people (old and new) is respectively 16.1% and 1%.This study, the first one conducted in Chad, has allowed us to know the seroprevalence of HBs Ag and anti-HCV antibodies among HIV infected people.

  12. An Economic Analysis of Boko Haram’s Activities in the Chad-Cameroon-Nigeria Border Area

    Directory of Open Access Journals (Sweden)

    TAMBA Isaac

    2015-02-01

    Full Text Available Terrorism is fast becoming a worldwide phenomenon with about 25% of attacks committed in developing countries. These attacks devastate societies causing huge economic loss with negative growth effects. Recent attacks suspectively conducted by Boko Haram in the north of Nigeria and along its border with Cameroon and Chad are already inflicting damage to local economies with a general drop in savings, investment, trade and a strain on domestic budgets. Poverty and exclusion generate dissidents and reactionary groups activities such as Boko Haram. But, the historical background permits to understand the emergency and the development of some of them. Tackling the Boko Haram threat requires a concerted multinational approach with a key socioeconomic component that incorporates the fact that conflict thrives better in circumstances of poverty and inequality.

  13. Higher CHADS2 score is associated with impaired coronary flow reserve: A study using phase contrast cine magnetic resonance imaging.

    Science.gov (United States)

    Kirigaya, Hidekuni; Kato, Shingo; Gyotoku, Daiki; Yamada, Nao; Iinuma, Naoki; Kusakawa, Yuka; Iguchi, Kohei; Miki, Yuko; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Kimura, Kazuo

    2016-10-15

    The presence of coronary microvascular dysfunction (CMD) is an important prognostic marker for coronary artery disease (CAD) patients. The purpose of this study was to investigate whether the CHADS2 score is associated with CMD evaluated by magnetic resonance imaging (MRI). One hundred forty three patients with known or suspected CAD (mean age 70.3±9.5years) were enrolled. All patients did not have any significant coronary stenosis on X-ray coronary angiography (CAG) at the time of MRI acquisition. By using a 1.5T MRI scanner, breath-hold phase contrast cine MRI images of coronary sinus (CS) were obtained to assess the blood flow of CS both at rest and during adenosine triphosphate (ATP) infusion. Coronary flow reserve (CFR) was calculated as CS blood flow during ATP infusion divided by CS blood flow at rest. CMD was defined as CFRcine MRI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. A new cichlid fish in the Sahara: The Ounianga Serir lakes (Chad), a biodiversity hotspot in the desert.

    Science.gov (United States)

    Trape, Sébastien

    In the rare perennial bodies of water of the Sahara desert, only a few fish species have survived to increasing aridification since the end of the last humid period at the Holocene, approximately 5000 years BP. Here, I report the occurrence of an undescribed haplochomine cichlid fish in Lake Boukou, one of the seven Ounianga Serir lakes (Chad). These lakes are located in one of the most arid areas of the Sahara desert, but they persist by virtue of subsurface inflow of fresh groundwater from a large fossil aquifer. Astatotilapia tchadensis sp. nov. is characterized by a black bar between eye and corner of mouth, rounded orange spots on anal fin, scales ctenoid, lower limb of first gill arch with 7-8 gill rackers, dorsal fin with 13-14 spines and 9-11 soft rays, anal fin with 3 spines and 8-9 soft rays, 29 or 30 lateral line scales, and lower pharyngeal dentition with enlarged molariform teeth. The new species is easily distinguished from A. desfontainii and A. flaviijosephii, the northernmost haplochromine species currently isolated from its other group members, and appears close to an unnamed species of Lake Chad basin. Ounianga Serir lakes and especially Lake Boukou present a remarkable diversity of fish, the highest known in the Sahara desert with a total of at least six fish species belonging to six genera and three families. They also constitute an exceptional natural landscape inscribed on the UNESCO world heritage list in 2012 and a biodiversity hotspot for desert vertebrate species.

  15. Occurrence of 1,1'-dimethyl-4,4'-bipyridinium (Paraquat) in irrigated soil of the Lake Chad Basin, Niger.

    Science.gov (United States)

    Crampon, Marc; Copard, Yoann; Favreau, Guillaume; Raux, Julie; Merlet-Machour, Nadine; Le Coz, Mathieu; Ibrahim, Maïmouna; Peulon-Agasse, Valérie; Portet-Koltalo, Florence

    2014-09-01

    Increased use of agrochemical products to improve yields for irrigated crops in sub-Saharan Africa has been accompanied by a significant increase in the risk of environmental contamination. Detailed examples of the fate of pesticides after initial spreading on crop fields are scarce in tropical regions, where safe practices and related health risks are poorly understood by smallholder farmers. In the semi-arid environment of the Lake Chad Basin, SE Niger, both intrinsic properties of pesticides and extrinsic factors such as soil and climate helped to characterize processes leading to an accumulation of pesticides in soils. Analysis by HPLC-UV of a 6 m deep soil profile showed the presence of Paraquat at concentrations from 953 ± 102 μg kg(-1) to 3083 ± 175 μg kg(-1) at depths between 0.80 and 2.75 m below the land surface. Soil analysis revealed that up to approximately 15 % of the total soil matrix consists of smectites, a clay mineral capable of retaining cationic pesticides such as Paraquat, and a very low content of organic matter (Paraquat could be stored and not bioavailable in a clayey barrier at approximately 2-m depth and therefore does not represent an immediate risk for populations or environment in this form. However, if the Paraquat application rate remains constant, the clayey barrier could reach a saturation limit within 150-200 years and 180-220 years if we consider a DT50 in soil of ~1,000 days (FAO). Consequently, it could lead to a deeper infiltration and so a pollution of groundwater. Such a scenario can represent a health risk for drinking water and for the Lake Chad, which is a major resource for this densely populated region of semi-arid Africa. Further analyses should focus on deeper layers and groundwater Paraquat contents to validate or invalidate the hypothesis of storage in this clay-rich layer.

  16. Development of Multivariate Regression Model for the Hydrologic System of Chari-Logone Catchment of the Lake Chad Basin.

    Science.gov (United States)

    Djimadoumngar, K. N.; Lee, J.; Bila, M. D.; Djoret, D.; Ichoku, C. M.

    2016-12-01

    Food security and water shortage from frequent droughts have been major issues in the northern sub-Saharan Africa (NSSA). The shrinking Lake Chad is one of the examples experiencing severe droughts and insecure food production. One of major challenges in the NSSA is the lack of data collection and monitoring systems to support a decision-making process in the agriculture and water resources management. The present study aims to help better understand a hydrologic system of the Lake Chad using multivariate regression models and enhance the models to forecast the river discharge along the Chari-Logone river system, which contributes over 90% of water into the Lake. As regressands, the river discharge data from two monitoring stations at Bongor and Logone-Gana were collected from 2001-2007. The regressors include precipitation, soil moisture, soil and air temperature, specific humidity, evapotranspiration and surface runoff. The Tropical Rainfall Measuring Mission (TRMM) data were used for the precipitation, and all other regressor parameters were obtained from the Global Land Data Assimilation System (GLDAS). We performed cross-correlation analysis between the river discharge and each regressor parameter to quantify the time lag to have the best correlation, which implies the responding time of the river discharge to the change of other hydrological parameters. The estimated time lags were integrated into the multivariate regression model. The results show that, for the river discharge data, precipitation, soil moisture, and surface runoff have linear relationships while evapotranspiration, soil and air temperature, and specific humidity have non-linear relationships. The observed river discharge and the predicted one, which is a function of precipitation and soil moisture, shows a good match with 93% of correlation.

  17. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010.

    Directory of Open Access Journals (Sweden)

    Rolf S Kaas

    Full Text Available The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE elements were identified and annotated. A global phylogeny (378 genomes was inferred using a single nucleotide polymorphism (SNP analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

  18. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010.

    Science.gov (United States)

    Kaas, Rolf S; Ngandjio, Antoinette; Nzouankeu, Ariane; Siriphap, Achiraya; Fonkoua, Marie-Christine; Aarestrup, Frank M; Hendriksen, Rene S

    2016-01-01

    The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE) elements were identified and annotated. A global phylogeny (378 genomes) was inferred using a single nucleotide polymorphism (SNP) analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

  19. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

    Science.gov (United States)

    Kaas, Rolf S.; Ngandjio, Antoinette; Nzouankeu, Ariane; Siriphap, Achiraya; Fonkoua, Marie-Christine; Aarestrup, Frank M.; Hendriksen, Rene S.

    2016-01-01

    The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE) elements were identified and annotated. A global phylogeny (378 genomes) was inferred using a single nucleotide polymorphism (SNP) analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains. PMID:27191718

  20. The Impact of the Colonial Legacy on Civil-Military Relations in Africa: Chad and the Sudan as Comparative Case Studies

    Science.gov (United States)

    1997-12-01

    European firms with cheaply produced raw materials and cheap labor; to find markets for the products of their factories; and to establish routes across...Weak States Persist: The Empirical and the Juridical in Statehood," in Atul Kohli , ed., The State and Development in the Third World. Princeton...excluding the first, were characterized by their religious orientation .61 Similar to Chad, all these kingdoms were in the northern part of the country

  1. Composition and cytotoxic activity of essential oils from Xylopia aethiopica (Dunal) A. Rich, Xylopia parviflora (A. Rich) Benth.) and Monodora myristica (Gaertn) growing in Chad and Cameroon

    Science.gov (United States)

    2014-01-01

    Background Cancer has become a global public health problem and the search for new control measures is urgent. Investigation of plant products such as essential oils from Monodora myristica, Xylopia aethiopica and Xylopia parviflora might lead to new anticancer therapy. In this study, we have investigated the antineoplastic activity of essential oils from fruits of these plants growing in Chad and Cameroon. Methods The essential oils obtained by hydrodistillation of fruits of Monodora myristica, Xylopia aethiopica and Xylopia parviflora collected in Chad and Cameroon were analyzed by GC-FID and GC-MS and investigated for their antiproliferative activity against the breast cancer cell line (MCF7). Results Overall, monoterpenes were mostly found in the six essential oils. Oils from X. aethiopica and X. parviflora from Chad and Cameroon mainly contain β-pinene at 24.6%, 28.2%, 35.7% and 32.9% respectively. Monodora myristica oils from both origins contain mainly α-phellandrene at 52.7% and 67.1% respectively. The plant origin did not significantly influence the chemical composition of oils. The six essential oils exerted cytotoxic activity against cancer (MCF-7) and normal cell lines (ARPE-19), with more pronounced effect on neoplastic cells in the majority of cases. The highest selectivity was obtained with the essential oils of X. parviflora from Chad and Cameroon (5.87 and 5.54) which were more cytotoxic against MCF-7 than against normal cell line (ARPE-19) with IC50 values of 0.155 μL/mL and 0.166 μL/mL respectively. Conclusions Essential oils from fruits of Monodora myristica, Xylopia aethiopica and Xylopia parviflora have shown acceptable antineoplastic potency, and might be investigated further in this regard. PMID:24708588

  2. CHADS2评分对心房颤动患者二尖瓣置换术围手术期脑卒中风险的预测作用%Predictive role of CHADS2 score for perioperative stroke risk in atrial fibrillation patients undergoing mitral valve replacement surgery

    Institute of Scientific and Technical Information of China (English)

    龚志云; 任崇雷; 姜胜利; 王明岩; 肖苍松; 高长青

    2016-01-01

    目的:缺血性脑卒中是心脏手术后严重并发症,但其危险因素尚待进一步研究。本研究旨在探讨CHADS2评分对二尖瓣置换术围手术期脑卒中风险的预测作用。方法选择2005年1月至2014年12月解放军总医院心血管外科行二尖瓣置换且术前合并房颤的患者共805例,年龄(53.7±10.5)岁,女性422例(52.4%)。观察不同CHADS2评分患者二尖瓣置换术后住院期间缺血性脑卒中发生情况;比较CHADS2评分≥2组和评分<2组脑卒中发生率;采用多因素logistic回归分析方法对围手术期常见脑卒中危险因素进行分析,研究CHADS2评分与术后脑卒中的关系。结果全组患者CHADS2评分为0分者493例(61.2%),1分者185例(23.0%),2分者92例(11.4%),3分者26例(3.2%),4分者9例(1.1%)。术后住院期间发生缺血性脑卒中共14例,发生率为1.7%。住院期间死亡16例,死亡率2.0%。脑卒中发生于CHADS2评分为0分者6例(发生率1.2%),1分者2例(发生率1.1%),2分者3例(发生率3.3%),3分者2例(发生率7.7%),4分者1例(发生率11.1%)。与CHADS2评分<2组比较, CHADS2评分≥2组脑卒中发生率显著升高(4.7% vs 1.2%;P =0.005)。与低CHADS2评分组比较,高CHADS2评分组患者术前合并颈动脉狭窄、术中同期行CABG和植入机械瓣比例较高,术后机械通气时间更长(P<0.05)。两组患者术后ICU停留时间以及住院期间病死率差异均无统计学意义(P>0.05)。多因素logistic回归分析结果显示, CHADS2评分≥2( OR =4.164,95%CI:1.388~12.495; P =0.011)和术后应用重组人凝血因子Ⅶa (OR=11.757,95%CI:2.909~47.520;P=0.001)是术后住院期间脑卒中的独立危险因素。结论 CHADS2评分高的房颤患者二尖瓣置换术后住院期间脑卒中发生率更高,CHADS2评分≥2是术

  3. Hydrological, chemical, and isotopic budgets of Lake Chad: a quantitative assessment of evaporation, transpiration and infiltration fluxes

    Science.gov (United States)

    Bouchez, Camille; Goncalves, Julio; Deschamps, Pierre; Vallet-Coulomb, Christine; Hamelin, Bruno; Doumnang, Jean-Claude; Sylvestre, Florence

    2016-04-01

    In the Sahelian belt, Lake Chad is a key water body for 13 million people, who live on its resources. It experiences, however, substantial and frequent surface changes. Located at the centre of one of the largest endorheic basins in the world, its waters remain surprisingly fresh. Its low salinity has been attributed to a low infiltration flow whose value remains poorly constrained. Understanding the lake's hydrological behaviour in response to climate variability requires a better constraint of the factors that control its water and chemical balance. Based on the three-pool conceptualization of Lake Chad proposed by Bader et al. (2011), this study aims to quantify the total water outflow from the lake, the respective proportions of evaporation (E), transpiration (T), and infiltration (I), and the associated uncertainties. A Bayesian inversion method based on lake-level data was used, leading to total water loss estimates in each pool (E + T + I = ETI). Sodium and stable isotope mass balances were then used to separate total water losses into E, T, and I components. Despite the scarcity of representative data available on the lake, the combination of these two geochemical tracers is relevant to assess the relative contribution of these three outflows involved in the control of the hydrological budget. Mean evapotranspiration rates were estimated at 2070 ± 100 and 2270 ± 100 mm yr-1 for the southern and northern pools, respectively. Infiltration represents between 100 and 300 mm yr-1 but most of the water is evapotranspirated in the first few kilometres from the shorelines and does not efficiently recharge the Quaternary aquifer. Transpiration is shown to be significant, around 300 mm yr-1 and reaches 500 mm yr-1 in the vegetated zone of the archipelagos. Hydrological and chemical simulations reproduce the marked hydrological change between the normal lake state that occurred before 1972 and the small lake state after 1972 when the lake surface shrunk to a one

  4. Coherent monsoonal changes in the northern tropics revealed by Chadian lakes (L. Chad and Yoa) sedimentary archives during the African Humid Period

    Science.gov (United States)

    Sylvestre, Florence; Kroepelin, Stefan; Pierre, Deschamps; Christine, Cocquyt; Nicolas, Waldmann; Kazuyo, Tachikawa; Amaral Paula, Do; Doriane, Delanghe; Guillaume, Jouve; Edouard, Bard; Camille, Bouchez; Jean-Claude, Doumnang; Jean-Charles, Mazur; Martin, Melles; Guillemette, Menot; Frauke, Rostek; Nicolas, Thouveny; Volkner, Wennrich

    2016-04-01

    In northern African tropics, it is now well established that the Last Glacial Maximum (LGM) was extremely dry followed by a wetter Holocene. Numerous palaeolake records reveal a fairly consistent pattern of a moister early Holocene resulting in a green Sahara followed by the onset of aridification about 4000 years ago. These palaeoenvironmental conditions are deciphered from several continental records distributed over the sub-Saharan zone and including diverse environments. However, pronounced differences in the timing and amplitude of these moisture changes inferred from sedimentary records point to both regional climatic variability change and site-specific influences of local topographic-hydrogeological factors which biased the evolution of water balance reconstructed from individual lacustrine archives. Here we present hydrological reconstructions from Chadian lakes, i.e. Lake Chad (c. 13°N) and Lake Yoa (19°N). Because of their location, both records allow to reconstruct lake level fluctuations and environmental changes according to a gradient from Sahelian to Saharan latitudes. Whereas Lake Chad is considered as a good sensor of climatic changes because of its large drainage basin covering 610,000 km2 in the Sudanian belt, Lake Yoa logs the northern precipitation changes in the Sahara. Combining sedimentological (laser diffraction grain size) and geochemical (XRF analysis) data associated with bio-indicators proxies (diatoms, pollen), we compare lake-level fluctuations and environmental changes during the last 12,000 years. After the hyperarid Last Glacial Maximum period during which dunes covered the Lake Chad basin, both lake records indicate an onset of more humid conditions between 12.5-11 ka cal BP. These resulted in lacustrine transgressions approaching their maximum extension at c. 10.5 ka cal BP. The lacustrine phase was probably interrupted by a relatively short drying event occurring around 8.2 ka cal BP which is well-defined in Lake Yoa by

  5. Application of CHADS2 score in prediction of left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation%应用CHADS2评分预测非瓣膜性心房颤动患者左心房/左心耳血栓

    Institute of Scientific and Technical Information of China (English)

    毕文静; 李颖; 任卫东; 杨军; 孙菲菲

    2013-01-01

    Objective To explore the correlation between CHADS2 score and prevalence of left atrial/left atrial appendage (LA/LAA) thrombus in patients with nonvalvular atrial fibrillation (NVAF). Methods Clinical data of 187 NVAF patients were analyzed, and CHADS2 score were derived. The patients were divided into thrombus group and non-thrombus group based on the results of TEE. The association between CHADS2 score and prevalence of LA/LAA thrombus, and frequency differences of CHADS2 factors between thrombus group and non-thrombus groups were analyzed. Results The prevalence of LA/LAA thrombus was 14. 44% (27/187) , and the detection rate of thrombus was 2. 13% (1/47), 13. 41% (11/82), 24.24% (8/33), 29.41% (5/17), 16.67% (1/6), 50.00% (1/2) in patients with CHADS2 score of 0, 1, 2, 3, 4 and 5, respectively. The prevalence of LA/LAA thrombus showed a trend of increase with the raising of CHADS2 score, and both of them had significant correlation (P = 0. 001). In thrombus group, 37. 04% (10/27) patients had history of congestive heart failure, higher than those in non-thrombus group (x2 =5. 92, P=0. 02). Of other factors of CHADS2 score, there was no significant difference between thrombus group and non-thrombus groups (all P>0. 05). Conclusion In NVAF patients, the prevalence of LA/LAA thrombus increases significantly with higher CHADS2 scores. Congestive heart failure is the only independent associated risk factor of LA/LAA thrombus.%目的 探讨非瓣膜性心房颤动(简称房颤)患者CHADS2评分与其左心房/左心耳(LA/LAA)血栓患病率间的关系.方法 回顾性分析187例非瓣膜性房颤患者资料,对其进行CHADS2评分,根据TEE检查结果分为血栓组及非血栓组,分析CHADS2评分与LA/LAA血栓患病率间的关系及各因子在两组中的差异.结果 187例中,27例(27/187,14.44%)确诊为LA/LAA血栓,其中0分者1例(1/47,2.13%),1分者11例(11/82,13.41%),2分者8例(8/33,24.24%),3分者5例(5/17,29.41%),4分者1例(1

  6. Are Salmonella-Induced Gastroenteritis Neglected in Developing Countries? Feedback from Microbiological Investigations in N'Djamena Hospitals, Chad.

    Science.gov (United States)

    Tabo, Djim-Adjim; Granier, Sophie A; Diguimbaye, Colette D; Marault, Muriel; Brisabois, Anne; Mama, Baïzina; Millemann, Yves

    2015-01-01

    Salmonella is considered to be one of the main pathogens causing human gastroenteritis worldwide. Looking for Salmonella in Africa in patients suffering from gastroenteritis is rather unusual, and the use of antibiotics is not subject to any regulation. This study intends for stressing the possible prominent importance of Salmonella in digestive diseases in Africa as well as identifying antimicrobial resistance of Salmonella isolates from faeces samples of human origin. All samples were collected from five N'Djamena hospitals, from patients suffering from diarrhoea. The collecting was undertaken over two periods of six months each: from August 2010 to January 2011 and from September 2011 to February 2012. Salmonella isolates were obtained by standard cultivation and serotyping methods. A total of 43 Salmonella isolates were identified, belonging to 21 different serovars. The most prevalent serovar was Salmonella Stanleyville (n = 7), followed by S. Anatum (n = 4) and S. Kottbus (n = 3). The other serovars were under-represented. The majority of these isolates were susceptible to all antibiotics tested (CLSI Standards), except two S. Enteritidis isolates that exhibited resistance to fluoroquinolones. The different serovars and antibiotic resistance profiles that were observed highlight the substantial diversity of Salmonella in N'Djamena, Chad. Roughly, one out of ten patients who consulted for gastroenteritis was shedding Salmonella spp. and none of them would have been diagnosed outside the context of this research program. This study may encourage local clinicians to explore more often salmonellosis suspicion in their daily practice.

  7. Nutritional Characterization and Phenolic Profiling of Moringa oleifera Leaves Grown in Chad, Sahrawi Refugee Camps, and Haiti.

    Science.gov (United States)

    Leone, Alessandro; Fiorillo, Giovanni; Criscuoli, Franca; Ravasenghi, Stefano; Santagostini, Laura; Fico, Gelsomina; Spadafranca, Angela; Battezzati, Alberto; Schiraldi, Alberto; Pozzi, Federica; di Lello, Sara; Filippini, Sandro; Bertoli, Simona

    2015-08-12

    Moringa oleifera is a plant that grows in tropical and subtropical areas of the world. Its leaves are rich of nutrients and bioactive compounds. However, several differences are reported in the literature. In this article we performed a nutritional characterization and a phenolic profiling of M. oleifera leaves grown in Chad, Sahrawi refugee camps, and Haiti. In addition, we investigated the presence of salicylic and ferulic acids, two phenolic acids with pharmacological activity, whose presence in M. oleifera leaves has been scarcely investigated so far. Several differences were observed among the samples. Nevertheless, the leaves were rich in protein, minerals, and β-carotene. Quercetin and kaempferol glycosides were the main phenolic compounds identified in the methanolic extracts. Finally, salicylic and ferulic acids were found in a concentration range of 0.14-0.33 and 6.61-9.69 mg/100 g, respectively. In conclusion, we observed some differences in terms of nutrients and phenolic compounds in M. oleifera leaves grown in different countries. Nevertheless, these leaves are a good and economical source of nutrients for tropical and sub-tropical countries. Furthermore, M. oleifera leaves are a source of flavonoids and phenolic acids, among which salicylic and ferulic acids, and therefore they could be used as nutraceutical and functional ingredients.

  8. Perceptions of the usefulness of external support to immunization coverage in Chad: an analysis of the GAVI-Alliance cash-based support.

    Science.gov (United States)

    Ferrinho, Paulo; Dramé, Mohammed; Tumusiime, Prosper

    2013-01-01

    Chad is one of the countries supported by the GAVI-Alliance that remains with unsatisfactory vaccination coverage. This paper tries to understand the main barriers to better coverage. These barriers were categorised as up or downstream against the health system building blocks as proposed by WHO and compared with barriers and activities identified by the country in its health system's strengthening grant proposal as approved by the GAVI Alliance in 2007. Data were collected using a modified Delphi system and by analysis of grant and annual report documents. Most of the activities anticipated under the GAVI health system's strengthening proposal are activities targeting downstream barriers (the neglect of upstream issues is of major importance in a decentralised state like Chad) and aligned with, not complementary to, immunization services strengthening activities. Further, both set of cash grants are blind to important recommendations such as the need to address barriers at the level of leadership and governance and at the level of the financing system and also about initiatives to promote community demand of vaccination services. IN CHAD SLOW VACCINATION PROGRESS IS AGGRAVATED BY SEVERAL CONTEXTUAL BARRIERS: the size of the country, the low population density, the nomadic nature of a significant part of its peoples, the recent civil war, associated with civil unrest and political instability and its geographical localization. In this situation it would be important to sustain downstream operations (the major focus of the ISS grant) while taking a long term view of the needs of the health system. The GAVI effectively supports downstream operations, but neglects the long term view.

  9. Migration of Chadic speaking pastoralists within Africa based on population structure of Chad Basin and phylogeography of mitochondrial L3f haplogroup

    Directory of Open Access Journals (Sweden)

    Mulligan Connie J

    2009-03-01

    Full Text Available Abstract Background Chad Basin, lying within the bidirectional corridor of African Sahel, is one of the most populated places in Sub-Saharan Africa today. The origin of its settlement appears connected with Holocene climatic ameliorations (aquatic resources that started ~10,000 years before present (YBP. Although both Nilo-Saharan and Niger-Congo language families are encountered here, the most diversified group is the Chadic branch belonging to the Afro-Asiatic language phylum. In this article, we investigate the proposed ancient migration of Chadic pastoralists from Eastern Africa based on linguistic data and test for genetic traces of this migration in extant Chadic speaking populations. Results We performed whole mitochondrial genome sequencing of 16 L3f haplotypes, focused on clade L3f3 that occurs almost exclusively in Chadic speaking people living in the Chad Basin. These data supported the reconstruction of a L3f phylogenetic tree and calculation of times to the most recent common ancestor for all internal clades. A date ~8,000 YBP was estimated for the L3f3 sub-haplogroup, which is in good agreement with the supposed migration of Chadic speaking pastoralists and their linguistic differentiation from other Afro-Asiatic groups of East Africa. As a whole, the Afro-Asiatic language family presents low population structure, as 92.4% of mtDNA variation is found within populations and only 3.4% of variation can be attributed to diversity among language branches. The Chadic speaking populations form a relatively homogenous cluster, exhibiting lower diversification than the other Afro-Asiatic branches (Berber, Semitic and Cushitic. Conclusion The results of our study support an East African origin of mitochondrial L3f3 clade that is present almost exclusively within Chadic speaking people living in Chad Basin. Whole genome sequence-based dates show that the ancestral haplogroup L3f must have emerged soon after the Out-of-Africa migration (around

  10. Parasitic infections, anemia and malnutrition among rural settled and mobile pastoralist mothers and their children in Chad.

    Science.gov (United States)

    Bechir, M; Schelling, E; Hamit, M A; Tanner, M; Zinsstag, J

    2012-06-01

    Malnutrition, resulting from various etiologies, is common in rural Chadian women and children. This cross-sectional study assessed the spectrum of parasitic infection and level of anemia and their effect on nutritional status in settled and mobile pastoral mothers and children near Lake Chad. Intestinal parasites were evaluated using direct fecal smears and the Kato-Katz technique. Malaria status was determined using Paracheck-Pf(®) rapid diagnostic test, and anemia was assessed with the Hemocue photometer. Nutritional status was evaluated using anthropometric parameters. At the end of the 2008 wet season, the prevalence of malnutrition was 36% [confidence interval (CI) 30-42] among women and 15% (CI 11-18) among children. The prevalence of intestinal parasitic infection was 75% (CI 68-83) among women and 60% (CI 53-66) among children. The predominant helminth species was Ascaris lumbricoides while Entamoeba histolytica/dispar was the most common protozoan. The hookworm prevalence was 14% (CI 8-20) in women and 18% (CI 13-23) in children. Malaria prevalence was low among women (1%, CI 0.5-2) and children (3% CI 2-5). No significant difference was observed in the prevalence of parasitic infection between the mobile pastoralist and rural sedentary populations. Thirty-four percent (CI 27-40) of nonpregnant women, 53% (CI 34-72) of pregnant women, and 27% (CI 23-32) of children were anemic. In subjects infected with Plasmodium, all women and 54% (CI 22-85) of children were anemic. Malnutrition was significantly associated with anemia in mothers and with selected intestinal parasites, anemia and age in their children.

  11. A new species of Nyanzachoerus (Cetartiodactyla: Suidae from the late Miocene Toros-Menalla, Chad, central Africa.

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    Jean-Renaud Boisserie

    Full Text Available During the latest Miocene and the early Pliocene, tetraconodontine suids were the most predominant large omnivorous mammals in Africa. Yet, new species were often identified on the grounds of limited evidence, a situation impacting their value for biochronological correlations as well as for environmental and biogeographical reconstructions. The description of the most abundant known collection of craniodental remains attributed to the tetraconodontine Nyanzachoerus helps to improve this situation. These specimens were collected in the upper Miocene deposits at Toros-Ménalla, northern Chad, central Africa, by the Mission Paléoanthropologique Franco-Tchadienne. We compared them with Nyanzachoerus from eastern and southern Africa, using extant species as a reference for patterns of morphological variation. Thanks to a large sample of observations, our work focused as much on craniomandibular morphology as on dental morphology and metrics (improved by an index scoring for the complexity of distal third molars and a detailed investigation of premolar-molar ratios. We recognized two taxa at Toros-Ménalla: Nyanzachoerus khinzir nov. sp. and Ny. cf. australis. We also revised the taxonomic status for other species, including: the restriction of Ny. syrticus to its holotype specimen from Sahabi (Libya, the resurrection of the nomen Ny. tulotos, and the synonymy of Ny. kuseralensis with Ny. waylandi. At Toros-Ménalla, Ny. khinzir was the only suid coexisting with the anthracotheriid Libycosaurus and the hominid Sahelanthropus, whereas Ny. cf. australis was associated with a different, probably younger faunal context. Nyanzachoerus. khinzir, which probably had a diversified diet, supports a latest Miocene biogeographical distinction between central Africa and eastern Africa.

  12. Seroprevalence of Rift Valley fever, Q fever, and brucellosis in ruminants on the southeastern shore of Lake Chad.

    Science.gov (United States)

    Abakar, Mahamat Fayiz; Naré, Ngandolo B; Schelling, Esther; Hattendorf, Jan; Alfaroukh, Idriss O; Zinsstag, Jakob

    2014-10-01

    The seroprevalence of Rift Valley fever (RVF), brucellosis, and Q fever among domestic ruminants on the southeastern shore of Lake Chad was studied. The study area consisted of two parts, including mainland and islands. On the mainland, the study was conducted in nine randomly selected villages and camps. On the islands, samples were collected from all four available sites. A total of 985 serum samples were collected and 924 were analyzed using enzyme-linked immunosorbent assay (ELISA) for RVF. A total of 561 samples collected from islands were analyzed using ELISA for Q fever and both ELISA and Rose Bengal tests (RBT) for brucellosis. The apparent RVF seroprevalence by species was 37.8% (95% confidence interval [CI] 34.2-41.3) in cattle, 18.8% (95% CI 12.3-25.2) in goats, and 10.8% (95% CI 3.0-18.5) in sheep. For brucellosis and Q fever, only cattle samples from islands were analyzed. For Q fever, the apparent seroprevalence was 7.8% (95% CI 5.6-10.1). For brucellosis, the RBT showed a prevalence of 5.7% (95% CI 3.8-7.6), and ELISA showed 11.9% (95% CI 9.3-14.6) with a kappa value of 0.53 showing a moderate agreement between the two tests. This study confirms the presence of the three diseases in the study area. More research is required to assess the importance for public health and conservation of the Kouri cattle breed.

  13. Combined Effect of El Nino Southern Oscillation and Atlantic Multidecadal Oscillation on Lake Chad Level Variability Region

    Science.gov (United States)

    Okonkwo, Churchill; Demoz, Belay; Sakai, Ricardo; Ichoku, Charles; Anarado, Chigozie; Adegoke, Jimmy; Amadou, Angelina; Abdullahi, Sanusu Imran

    2015-01-01

    In this study, the combined effect of the Atlantic Multidecadal Oscillation (AMO) and El Niño Southern Oscillation (ENSO) on the Lake Chad (LC) level variability is explored. Our results show that the lake level at the Bol monitoring station has a statistically significant correlation with precipitation (R2 = 0.6, at the 99.5% confidence level). The period between the late 1960s and early 1970s marked a turning point in the response of the regional rainfall to climatic drivers, thereby severely affecting the LC level. Our results also suggest that the negative impact of the cold phase of AMO on Sahel precipitation masks and supersedes the positive effect of La Niña in the early the 1970s. The drop in the size of LC level from 282.5 m in the early 1960s to about 278.1 m in 1983/1984 was the largest to occur within the period of study (1900-2010) and coincides with the combined cold phase of AMO and strong El Niño phase of ENSO. Further analyses show that the current warm phase of AMO and increasing La Niña episodes appear to be playing a major role in the increased precipitation in the Sahel region. The LC level is responding to this increase in precipitation by a gradual recovery, though it is still below the levels of the 1960s. This understanding of the AMO-ENSO-rainfall-LC level association will help in forecasting the impacts of similar combined episodes in the future. These findings also have implications for long-term water resources management in the LC region.

  14. Toros-Menalla (Chad, 7 Ma), the earliest hominin-bearing area: How many mammal paleocommunities?

    Science.gov (United States)

    Le Fur, Soizic; Fara, Emmanuel; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2014-04-01

    The fossiliferous area of Toros-Menalla (TM) (Djurab Desert, northern Chad) has yielded one of the richest African mammal faunas of the late Miocene. It is also the place where the earliest known hominin, Sahelanthropus tchadensis, was found. Although more than 300 localities are recorded in that area, previous paleoecological studies focused only on the largest and richest one. The integration of the material from other TM localities, and thus of a significant number of mammal taxa, is crucial to improve the corresponding paleoenvironmental reconstructions. Before such inferences can be drawn, it is necessary to test for the ecological integrity of these mammal assemblages: how many paleocommunities do they represent? The faunal structures of several assemblages selected for their apparent resilience to sampling biases are compared here. The criteria used in the inter-assemblage comparison are ecological diversity, taxonomic structure (taxonomic rank of abundance) and taxonomic composition. Based on multivariate analyses, two groups of TM assemblages can be distinguished. One of them contains the hominin-bearing assemblages. It is taxonomically richer and shows a wider ecological spectrum than its counterpart. The degree of taphonomic alteration undergone by the TM assemblages, as well as the distribution of amphibious mammals among them, suggest different depositional settings for these two groups of assemblages, the richest of which was probably associated with lower hydraulic energy. Overall, it seems that the TM assemblages recorded the same mammal paleocommunity preserved in two contrasted depositional settings. Moreover, the spatial overlap of these assemblages provides further evidence for the mosaic character of the landscape associated with S. tchadensis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Prevalence and antimicrobial resistance of non-typhoidal Salmonella serotypes isolated from laying hens and broiler chicken farms in N'Djamena, Chad.

    Science.gov (United States)

    Tabo, Djim-adjim; Diguimbaye, Colette D; Granier, Sophie A; Moury, Frédérique; Brisabois, Anne; Elgroud, Rachid; Millemann, Yves

    2013-09-27

    This study aimed at updating knowledge on the prevalence and antimicrobial resistance characteristics of Salmonella isolated from poultry in the province of N'Djamena, Chad. The results collected during this study provide the first baseline data on the prevalence of contamination by Salmonella in laying hens and broiler chicken farms in N'Djamena. All samples were collected from sixteen poultry farms over two periods of six months each: from August 2010 to January 2011 and from September 2011 to February 2012. Diagnostic methods used during this study allowed to isolate eighty four Salmonella strains, belonging to twenty seven different serotypes. The most frequent serotypes were Salmonella Colindale (19%) followed by S. Minnesota (18%) S. Havana and S. Riggil (each 6%), S. Kottbus and S. Amager (4.7%), S. Idikan, Mississipi, and Muenchen (3.6%). Other serotypes were poorly represented. The majority of these serotypes were susceptible to all antibiotics tested (CLSI Standards), except some S. Colindale isolates that exhibited a decreased susceptibility to fluoroquinolones, S. Limete resistant to three antibiotics and S. Minnesota isolates resistant to five different antimicrobial classes. The different serotypes and antibiotic resistance profiles that were observed highlight the substantial diversity of Salmonella in Chad, the contribution of avian isolates to human salmonellosis and Salmonella's capacity to colonize all types of environment worldwide.

  16. Economic benefits of keeping vaccines at ambient temperature during mass vaccination: the case of meningitis A vaccine in Chad.

    Science.gov (United States)

    Lydon, Patrick; Zipursky, Simona; Tevi-Benissan, Carole; Djingarey, Mamoudou Harouna; Gbedonou, Placide; Youssouf, Brahim Oumar; Zaffran, Michel

    2014-02-01

    To evaluate the potential economic benefits of keeping a meningitis A vaccine at or near ambient temperature for up to 4 days during a mass vaccination campaign. During a 10-day mass vaccination campaign against meningitis A in three regions of Chad in 2011, the costs associated with storage and transport of the vaccine in a traditional cold chain system were evaluated. A mathematical model was used to estimate the savings that could have been achieved if the vaccine had been stored at or near ambient temperature--in a "controlled temperature" chain--at the peripheral levels of the supply chain system. The cost of the cold chain and associated logistics used in the campaign in Chad was 0.24 United States dollars (US$) per person vaccinated. In the modelled scenario for a controlled temperature chain, however, these costs dropped by 50% and were estimated to be only US$ 0.12 per person vaccinated. The implementation of a "controlled temperature" chain at the most peripheral levels of the supply chain system--assuming no associated loss of vaccine potency, efficacy or safety--could result in major economic benefits and allow vaccine coverage to be extended in low-resource settings.

  17. Physical Abuse, Cognitive and Emotional Processes, and Aggressive/Disruptive Behavior Problems

    Science.gov (United States)

    Teisl, Michael; Cicchetti, Dante

    2008-01-01

    Cognitive and emotional processes were examined in maltreated children with a history of physical abuse (n = 76), children with a history of maltreatment other than physical abuse (i.e., sexual abuse, physical neglect, and emotional maltreatment; n = 91), and a group of non-maltreated comparison children (N = 100). Physical abuse was associated…

  18. Why the Prevention of Aggressive Disruptive Behaviors in Middle School Must Begin in Elementary School.

    Science.gov (United States)

    Greer-Chase, Marlene; Rhodes, Warren A.; Kellam, Sheppard G.

    2002-01-01

    Suggests that the course and malleability of maladaptive behaviors are partly rooted in early aggressive behaviors occurring in poorly managed classrooms. Encourages teacher education training programs incorporate classroom management training. Concludes that the nature and severity of aggressive behaviors in middle school depend on effective…

  19. The influence of classroom aggression and classroom climate on aggressive-disruptive behavior.

    Science.gov (United States)

    Thomas, Duane E; Bierman, Karen L; Powers, C J

    2011-01-01

    Research suggests that early classroom experiences influence the socialization of aggression. Tracking changes in the aggressive behavior of 4,179 children from kindergarten to second-grade (ages 5-8), this study examined the impact of 2 important features of the classroom context--aggregate peer aggression and climates characterized by supportive teacher-student interactions. The aggregate aggression scores of children assigned to first-grade classrooms predicted the level of classroom aggression (assessed by teacher ratings) and quality of classroom climate (assessed by observers) that emerged by the end of Grade 1. Hierarchical linear model analyses revealed that first-grade classroom aggression and quality of classroom climate made independent contributions to changes in student aggression, as students moved from kindergarten to second grade. Implications for policy and practice are discussed.

  20. A study of the relict fish fauna of northern Chad, with the first records of a polypterid and a poeciliid in the Sahara desert.

    Science.gov (United States)

    Trape, Sébastien

    2013-01-01

    Seventeen species and sub-species of fishes belonging to four families (Cyprinidae, Clariidae, Aplocheilidae, Cichlidae) were known to occur in perennial bodies of water in the Sahara desert. The study of fishes collected in Lake Boukou near Ounianga Serir (Borkou, northern Chad) shows, for the first time, the occurrence in the Sahara desert of relict populations of Polypterus senegalus (Polypteridae) and Poropanchax normani (Poeciliidae). The Cichlidae Tilapia zilli was also collected in this lake. With these new records, the relict fish fauna currently known in lakes and gueltas of the Borkou plateaus comprises six species. In the Ennedi Mountains, where the specific status of Barbus populations was unclear, B. macrops was collected in Bachikere guelta. The toad Amietophrynus regularis was collected in Ounianga Kebir.

  1. Assessment of hospital morbidity, mortality, and cost-effectiveness of a nutritional program for children under 5 years of age in Pala, Chad.

    Science.gov (United States)

    Parent, F; Coppieters, Y

    2000-08-01

    This paper analyses the effectiveness of case management at referral level for malnourished sick children in a rural district health system in the south of Chad (Pala district). The methodology followed was based on a cohort study of malnourished children as well as a cost-effective analysis of alternative options for nutritional rehabilitation strategies. Results show that effective case management at hospital level is possible with few resources as long as the nutritional rehabilitation programme is implemented on an integrated basis including early diagnosis of malnutrition for all children admitted to hospital and not to wait for a normal weight-for-height but discharge when the hospital is no longer the best place to avoid further mortality.

  2. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer; Ngandjio, Antoinette; Nzouankeu, Ariane

    2016-01-01

    The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic...... make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE) elements were identified and annotated. A global phylogeny (378 genomes) was inferred using...... a single nucleotide polymorphism (SNP) analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae...

  3. Hydrocarbon Potentials, Thermal and Burial History in Herwa-1 Well from the Nigerian Sector of the Chad Basin: An Implication of 1-D Basin Modeling Study

    Directory of Open Access Journals (Sweden)

    Abubakar Mijinyawa

    2013-06-01

    Full Text Available This research study attempt to evaluate the hydrocarbon potentials, thermal and burial history and the timing of hydrocarbon generation in Herwa-1 well within the Nigerian Sector of the Chad basin. Organic geochemical study of some ditch cuttings samples from Herwa-1 well and a One-dimensional basin modeling study was carried out. The result of the geochemical analysis revealed a moderate to good TOC greater than 0.5wt% in Fika and Gongila formation, the Hydrogen Index (HI ranges from 150-300 (mgHC/g and the Tmax values falls within the range of greater than or equal to 430°C. The hydrocarbon potentials in Herwa-1 well was further supported with the values of S1+S2 which is greater than or equal to 2 mg/g of rock in almost all the samples, suggesting a good hydrocarbon potentials. The 1-D basin model was constructed for Herwa-1 well in order to assess the burial history and thermal maturity of the potential source rocks in the Nigerian sector of the Chad basin. The modeling results indicate that maximum burial occurred in the late Miocene and suggesting erosion might have been the cause of the thinning of the Tertiary sediments in the present time. The calibration of Vitrinite reflectance against Temperature revealed the present day heat flow to be at 60 mW/m2 and Paleo heat flow falls within the range of 68 mW/m2. However, it is also revealed that Oil Window begins at (0.60-1.30% VRr at the depth of (2000-3000 m in the middle Cretaceous and the Gas Window start during the late Cretaceous to Tertiary with a value of (1.3-2.5% VRr at a depth greater than (3500 m.

  4. [Evaluation of the nutritional status of children less than 5 years of age in Moundou, Chad: correlations with morbidity and hospital mortality].

    Science.gov (United States)

    Renaudin, P

    1997-01-01

    The purpose of this study carried out in the pediatric ward of the regional hospital in Moundou, Chad, between June 1992 and May 1993 was to assess the prevalence of protein-energy malnutrition in children under 5 years of age and its relationship with various diseases and in-hospital mortality. A total of 1050 children ranging in age from 1 to 59 months were hospitalized in the ward during the study period and included in the study. Nutritional status was assessed using weight-for-height (W/H) and height-for-age (H/A) charts. Diarrhea, dehydratation, malaria, anemia, acute respiratory infection, and meningitis accounted for 85.5% of the underlying diseases and for 76% of deaths. At entry into study the prevalence of malnutrition was 63.1% (W/H malnutrition (W/H Malnutrition was more prevalent in children under than over 2 years of age (80% vs. 42.7% respectively). The same trend was observed with regard to severe malnutrition. The prevalence of malnutrition was highest in children with acute respiratory infections or diarrhea (61.3% and 89.8% respectively). Mortality was significantly higher in severely malnourished children and malnourished children with respiratory infection especially at ages under 1 year. Death was attributed to malnutrition in 30% of cases. Better low cost nutritional care is currently feasible. The most cost efficient methods of fighting against this problem are prevention and education especially concerning breast feeding.

  5. [Seasonal variations in the nutritional status of nomad and sedentary children less than 5 years of age living in the Sahel in Chad].

    Science.gov (United States)

    Bechir, M; Schelling, E; Bonfoh, B; Seydi, M; Wade, S; Moto, D D; Tanner, M; Zinsstag, J

    2010-08-01

    Malnutrition is widespread among rural and nomad populations in the Sahel. It is linked to socio-economic factors and exhibits significant seasonal variations. The aim of this study was to assess the prevalence of malnutrition and associated risk factors among children less than 5 years of age. A repeated cross-sectional study design based on interviews and anthropometric measurements was used. A total of 653 nomad children and 579 sedentary children ranging in age from 0 to 59 months were randomly selected in households/camps on the south-eastern shore of Lake Chad. Data were collected from the same number of children at the end of the dry season (May/June, 2007) and at the end of rainy season (October 2007). Findings showed significant interseasonal variation in the prevalence of global acute malnutrition (GAM) between the end of the dry season and end of the rainy season. The respective variations were 17.9% to 13.7% (p = 0.03) in nomad children and 16.5% to 10.6% (p = 0.004) in sedentary children. Backward stepwise multivariate analysis by logistic regression showed that GAM among children under 5 years of age was significantly correlated with the following risk factors: seasonal variation, child's age, mother's nutritional status, ethnic group, and place of residence (LRT=172 and p < 0.001 for the logistic regression model). These findings demonstrate the critical state of the nutritional situation in the Sahel and rural areas.

  6. Iron oxide minerals in dust-source sediments from the Bodélé Depression, Chad: Implications for radiative properties and Fe bioavailability of dust plumes from the Sahara

    Science.gov (United States)

    Moskowitz, Bruce M; Reynolds, Richard; Goldstein, Harland; Beroquo, Thelma; Kokaly, Raymond; Bristow, Charlie S

    2016-01-01

    Atmospheric mineral dust can influence climate and biogeochemical cycles. An important component of mineral dust is ferric oxide minerals (hematite and goethite) which have been shown to influence strongly the optical properties of dust plumes and thus affect the radiative forcing of global dust. Here we report on the iron mineralogy of dust-source samples from the Bodélé Depression (Chad, north-central Africa), which is estimated to be Earth’s most prolific dust producer and may be a key contributor to the global radiative budget of the atmosphere as well as to long-range nutrient transport to the Amazon Basin. By using a combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy, we document the abundance and relative amounts of goethite, hematite, and magnetite in dust-source samples from the Bodélé Depression. The partition between hematite and goethite is important to know to improve models for the radiative effects of ferric oxide minerals in mineral dust aerosols. The combination of methods shows (1) the dominance of goethite over hematite in the source sediments, (2) the abundance and occurrences of their nanosize components, and (3) the ubiquity of magnetite, albeit in small amounts. Dominant goethite and subordinate hematite together compose about 2% of yellow-reddish dust-source sediments from the Bodélé Depression and contribute strongly to diminution of reflectance in bulk samples. These observations imply that dust plumes from the Bodélé Depression that are derived from goethite-dominated sediments strongly absorb solar radiation. The presence of ubiquitous magnetite (0.002–0.57 wt%) is also noteworthy for its potentially higher solubility relative to ferric oxide and for its small sizes, including PM < 0.1 μm. For all examined samples, the average iron apportionment is estimated at about 33% in ferric oxide minerals, 1.4% in magnetite, and 65

  7. Characterizing 13 Years of Surface Water Variability from MODIS-based Near Real-Time Flood Mapping Products in the Indus River, Tonle Sap Lake, and Lake Chad.

    Science.gov (United States)

    Slayback, D. A.; Brakenridge, G. R.; Policelli, F. S.

    2015-12-01

    Driven by an increase in extreme weather events in a warming world, flooding appears to be increasing in many regions. Since 2012, we have been using the twice-daily near-global observations of the two MODIS instruments to operate a near real-time flood mapping capability. Primarily intended to support disaster response efforts, our system generates daily near-global maps of flood water extent, at 250 m resolution. Although cloud cover is a challenge, the twice-daily coverage from the Terra and Aqua satellites helps to capture most major events. We use the MOD44W product (the "MODIS 250-m land-water mask") to differentiate "normal" water from flood water. Products from the system are freely available, and used by disaster response agencies and academic and industry researchers. An open question, however, is: how "normal" are recently observed floods? Destructive and — as reported by the press — record floods seem to be occurring more and more frequently. With the MODIS archive going back to 1999 (Terra satellite) and 2002 (Aqua satellite), we now have more than a decade of twice-daily near-global observations to begin answering this question. Although the 13 years of available twice-daily data (2002-2015) are not sufficient to fully characterize surface water normals (e.g., 100-year floods), we can start examining recent trends in surface water extent and flood frequency. To do so, we have back-processed our surface water product through mid-2002 (Aqua launch) for a few regions, and have used this to evaluate the variability in surface water extent and flood frequency. These results will eventually feed back into an improved characterization of flood water in our near real-time flood product. Here we will present results on trends in surface water extent and flood frequency for a few regions, including the Indus in Pakistan, the Tonle Sap lake in Cambodia, and lake Chad in Africa.

  8. Integrated well log and 2-D seismic data interpretation to image the subsurface stratigraphy and structure in north-eastern Bornu (Chad) basin

    Science.gov (United States)

    Isyaku, Aminu A.; Rust, Derek; Teeuw, Richard; Whitworth, Malcolm

    2016-09-01

    Structural and stratigraphic mapping within the Bornu Basin in north east Nigeria was commonly carried out using traditional field geological methods. However, such traditional approaches remain inadequate in the semi-arid region characterised by topographically flat areas and lack of continuous bedrock outcrops that are mostly concealed beneath sand cover. Previous studies in the north-eastern part of the basin carried out using ditch cuttings from few wells and disconnected seismic data were largely inadequate and the resulting stratigraphic analyses were more often generalised. This paper presents an integrated structural and stratigraphic study of the basin using combined subsurface geophysical datasets. A Combined Log Pattern (CLP) method is a well log analysis, which utilises various well log data including gamma ray, resistivity, bulk density and sonic logs to identify lithology and stratigraphic boundaries of subsurface formations. This method is applied to constrain the subsurface stratigraphy of the north-eastern part of the Bornu Basin bordering the Lake Chad. In addition to qualitative combined well log analysis, the time-depth relationship of the sonic log and seismic data was quantitatively determined by tying a well with an intersecting seismic section to validate the stratigraphic facies horizons identified. Four well log facies and their environments of deposition were characterised from the combined well log analysis of the different log types. It is discovered that the Cretaceous basement structural features controlled the deposition of overlying formations in the basin. Without intact core data, the shallower wells were discovered to have bottomed over subsurface horst features while deeper wells penetrated into the basal facies contained mainly within the grabens. Main subsurface structural lineaments in the area include NW-SE, NE-SW and NNW-SSE trending faults, which mainly formed the horst and graben features. Some stratigraphic formations

  9. 89. Estudio multicéntrico español de la capacidad predictiva de las escalas de riesgo CHADS2 y CHA2DS2vasc en el accidente cerebrovascular tras cirugía coronaria aislada

    Directory of Open Access Journals (Sweden)

    E. Martín

    2012-04-01

    Resultados: Veinte mil novecientos ochenta pacientes incluidos, 282 desarrollaron ACV postoperatorio (1,34%. La incidencia de ACV fue superior en pacientes con insuficiencia cardíaca congestiva (ICC y/o fracción de eyección inferior al 40% (4,10 vs 0,83%, diabéticos (1,70 vs 1,11%, hipertensos (1,60 vs 0,98%, ACV previo (2,72 vs 1,26% y a enfermedad arterial periférica (EAP (3,04 vs 1,04%; p < 0,05. En el análisis multivariante, ICCC (odds ratio [OR]: 4,06, ACV previo (OR: 1,48, EAP (OR: 1,49 constituyeron factores de riesgo independientes para el desarrollo de ACV postoperatorio (p < 0,05. El AUC para CHADS2 fue 0,666, y para CHA2DS2VASc 0,655 (p < 0,0001. La distribución de las tasas de ACV postoperatorio según las puntuaciones de las anteriores escalas se recoge en la figura 1 (p < 0,0001. Conclusiones: Las escalas de riesgo CHADS2 y CHA2DS-2VASC pueden resultar útiles en la práctica clínica para estratificar el riesgo de desarrollo de ACV postoperatorio en pacientes sometidos a CCA.

  10. 14 February 2012 - Ambassadors from Algeria, Brunei Darussalam, Canada, Chad, Tunisia, Permanent Representatives to the United Nations Office at Geneva in the LHC tunnel at Point 1, ATLAS visitor centre, and ATLAS underground experimental area, throughout accompanied by Advisers P. Fassnacht, E. Tsesmelis and R. Voss

    CERN Multimedia

    Jean-Claude Gadmer

    2012-01-01

    14 February 2012 - Ambassadors from Algeria, Brunei Darussalam, Canada, Chad, Tunisia, Permanent Representatives to the United Nations Office at Geneva in the LHC tunnel at Point 1, ATLAS visitor centre, and ATLAS underground experimental area, throughout accompanied by Advisers P. Fassnacht, E. Tsesmelis and R. Voss

  11. Re-evaluation of the petroleum potential of the Kufra Basin (SE Libya, NE Chad): does the source rock barrier fall?

    Energy Technology Data Exchange (ETDEWEB)

    Luening, Sebastian [Wales Univ., Inst. of Geography and Earth Sciences, Aberystwyth (United Kingdom); LASMO plc, London (United Kingdom); Craig, Jonathan [LASMO plc, London (United Kingdom); Fitches, Bill [Robertson Research International, Llandudno (United Kingdom); Mayouf, Juma; Busrewil, Ahmed; El Dieb, Mufta; Gammudi, Amar [Petroleum Research Centre, Tripoli (Libya); Loydell, David [Portsmouth Univ., School of Earth, Environmental and Physical Sciences, Portsmouth (United Kingdom); McIlroy, Duncan [Liverpool Univ., STRAT Group, Liverpool (United Kingdom)

    1999-11-01

    The Kufra Basin is a large, underexplored, Palaeozoic intracratonic sag basin in SE Libya and NE Chad with extensions into NW Sudan and SW Egypt. The basin fill consists of shallow marine to fluvial deposits ranging in age from infracambrian to Cretaceous. Geologically, the basin is very similar to the Murzuq Basin in SW Libya which recently presented Libya with its largest oil discovery for over a decade. Most of the hydrocarbon play elements known from the Murzuq Basin also occur in the Kufra Basin: thick, porous Cambro-Ordovician sandstones are present and would form good reservoirs, lower Silurian shales may act as effective seals, and there are potential structural traps in seismically defined fault blocks. However, the source rock availability in the Kufra Basin is currently unclear. One of the two main source rock candidates in the basin is a lower Silurian shale unit (Tanezzuft Formation). The Tanezzuft shales have been described as being up to 130 m thick in outcrops at the basin margins, but the shales were found to be replaced by siltstones and sandstones in two dry exploration wells drilled in the northern part of the basin by AGIP between 1978 and 1981. Hot shales developed at the base of this widespread Silurian shale unit form important source rocks in many areas of North Africa and Arabia. These hot shales are interpreted to have been deposited in palaeodepressions, such as incised valleys of the preceding lowstand, or intrashelf basins, during the initial transgression after the melting of the late Ordovician ice cap. The areal distribution of the organic-rich unit is, therefore, discontinuous. Fieldwork in the Kufra Basin has shown that the basal Tanezzuft horizon is not exposed on the northern and eastern margins of the basin. Deep infracambrian rift grabens have been interpreted on seismic lines from the Kufra Basin and, in analogy to Oman and Algeria, could contain organic-rich infracambrian deposits. The infracambrian succession in the Kufra

  12. Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure.

    Directory of Open Access Journals (Sweden)

    Sumi Biswas

    Full Text Available The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i ChAd63-MVA immunization, ii immunization and CHMI, and iii primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i total IgG responses before and after CHMI, ii responses to allelic variants of MSP1 and AMA1, iii functional growth inhibitory activity (GIA, iv IgG avidity, and v isotype responses (IgG1-4, IgA and IgM. These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other

  13. Effective groundwater modeling of the data-poor Nubian Aquifer System (Chad, Egypt, Libya, Sudan) - use of parsimony and 81Kr-based groundwater ages (Invited)

    Science.gov (United States)

    Voss, C. I.; Soliman, S. M.; Aggarwal, P. K.

    2013-12-01

    Important information for management of large aquifer systems can be obtained via a parsimonious approach to groundwater modeling, in part, employing isotope-interpreted groundwater ages. ';Parsimonious' modeling implies active avoidance of overly-complex representations when constructing models. This approach is essential for evaluation of aquifer systems that lack informative hydrogeologic databases. Even in the most remote aquifers, despite lack of typical data, groundwater ages can be interpreted from isotope samples at only a few downstream locations. These samples incorporate hydrogeologic information from the entire upstream groundwater flowpath; thus, interpreted ages are among the most-effective information sources for groundwater model development. This approach is applied to the world's largest non-renewable aquifer, the transboundary Nubian Aquifer System (NAS) of Chad, Egypt, Libya and Sudan. In the NAS countries, water availability is a critical problem and NAS can reliably serve as a water supply for an extended future period. However, there are national concerns about transboundary impacts of water use by neighbors. These concerns include excessive depletion of shared groundwater by individual countries and the spread of water-table drawdown across borders, where neighboring country near-border shallow wells and oases may dry. Development of a parsimonious groundwater flow model, based on limited available NAS hydrogeologic data and on 81Kr groundwater ages below oases in Egypt, is a key step in providing a technical basis for international discussion concerning management of this non-renewable water resource. Simply-structured model analyses, undertaken as part of an IAEA/UNDP/GEF project, show that although the main transboundary issue is indeed drawdown crossing national boundaries, given the large scale of NAS and its plausible ranges of aquifer parameter values, the magnitude of transboundary drawdown will likely be small and may not be a

  14. Demographic and health surveillance of mobile pastoralists in Chad: integration of biometric fingerprint identification into a geographical information system

    Directory of Open Access Journals (Sweden)

    Daniel Weibel

    2008-11-01

    Full Text Available There is a pressing need for baseline demographic and health-related data to plan, implement and evaluate health interventions in developing countries, and to monitor progress towards international development goals. However, mobile pastoralists, i.e. people who depend on a livestock production system and follow their herds as they move, remain marginalized from rural development plans and interventions. The fact that mobile people are hard to reach and stay in contact with is a plausible reason why they are underrepresented in national censuses and/or alternative sequential sample survey systems. We present a proof-of-concept of monitoring highly mobile, pastoral people by recording demographic and health-related data from 933 women and 2020 children and establishing a biometric identification system (BIS based on the registration and identification of digital fingerprints. Although only 22 women, representing 2.4% of the total registered women, were encountered twice in the four survey rounds, the approach implemented is shown to be feasible. The BIS described here is linked to a geographical information system to facilitate the creation of the first health and demographic surveillance system in a mobile, pastoralist setting. Our ultimate goal is to implement and monitor interventions with the “one health” concept, thus integrating and improving human, animal and ecosystem health.

  15. Effects of host demography, season and rainfall on the prevalence and parasitic load of gastrointestinal parasites of free-living elephants (Loxodonta africana) of the Chad Basin National Park, Nigeria.

    Science.gov (United States)

    Mbaya, A W; Ogwiji, M; Kumshe, H A

    2013-10-15

    The effects of host demography, rainfall and season on the prevalence and parasitic load of gastrointestinal parasites of African elephants (Loxodonta africana) of the Chad Basin National Park were determined for the first time. Out of the 274 elephants examined, 36.86% were infected. Of the 178 males examined, 35.96% harboured Strongyloides, Coccidia and Strongyles with worm burdens of 75.6 +/- 0.3, 125.2 +/- 1.4 and 420.2 +/- 0.1, respectively. Among the males, the larvae of Strongyloides papillosus were recovered from those infected with Strongyloides while Haemonchus contortus, Trichostrongylus colubriformis, Murshidia species and Oesophagostomum columbianum were recovered from those infected with Strongyles. Those infected with Coccidia yielded Eimeria bovis. Of the 96 females examined, 38.54% were infected with Coccidia and Strongyles with 102.2 +/- 0.7 Oocysts per Gram of faeces (OPG) and 360.2 +/- 0.1 Eggs per Gram of faeces (EPG), respectively. The helminth larvae recovered from the females infected with Strongyles were; H. contortus, O. columbianum and Murshidia species, while those infected with Coccidia yielded E. bovis. Out of the 213 adults examined, 27.23% were infected with Strongyloides and Strongyles with 187.3 +/- 0.4 and 208.4 +/- 0.1 EPG, respectively. The larvae of S. papillosus were recovered from those infected with Strongyloides, while the larvae of H. contortus, O. columbianum, T. colubriformis and Murshidia were recovered from those infected with Strongyles. Of the 61 young examined, 70.49% were infected with Coccidia and Strongyloides with OPG of 88.4 +/- 0.2 and EPG of 624.4 +/- 0.2. The elephants were mostly infected in the rainy season. The worm burden and prevalence according to sex and age were highest in August. The males and young were more infected than their counterparts. In conclusion, intrinsic and extrinsic factors played a role on the prevalence and worm burden of gastrointestinal parasites of elephants of the Chad Basin

  16. Free treatment, rapid malaria diagnostic tests and malaria village workers can hasten progress toward achieving the malaria related millennium development goals: the Médecins Sans Frontières experience from Chad, Sierra-Leone and Mali

    Directory of Open Access Journals (Sweden)

    Katie Tayler-Smith

    2011-02-01

    Full Text Available Halving the burden of malaria by 2015 and ensuring that 80% of people with malaria receive treatment is among the health related targets of the Millennium Development Goals (MDGs. Despite political momentum toward achieving this target, progress is slow and many with malaria (particularly in poor and rural communities in Africa are still without access to effective treatment. Finding ways to improve access to anti-malarial treatment in Africa is essential to achieve the malaria related and other MDG targets. During its work in Chad, Sierra Leone and Mali in the period 2004 to 2008, Médecins Sans Frontières showed that it was possible to significantly improve access to effective malaria treatment through: i the removal of health centre level user fees for essential healthcare for vulnerable population groups, ii the introduction of free community based treatment for children using malaria village workers to diagnose and treat simple malaria in communities where geographical and financial barriers limited access to effective malaria care, iii the improved diagnosis and treatment of malaria using rapid diagnosis tests and artemisinin based combination therapy, at both health facilities and in the community. This paper describes and discusses these strategies and their related impact.

  17. Iron oxide minerals in dust-source sediments from the Bodélé Depression, Chad: Implications for radiative properties and Fe bioavailability of dust plumes from the Sahara

    Science.gov (United States)

    Moskowitz, Bruce M.; Reynolds, Richard L.; Goldstein, Harland L.; Berquó, Thelma S.; Kokaly, Raymond F.; Bristow, Charlie S.

    2016-09-01

    Atmospheric mineral dust can influence climate and biogeochemical cycles. An important component of mineral dust is ferric oxide minerals (hematite and goethite) which have been shown to influence strongly the optical properties of dust plumes and thus affect the radiative forcing of global dust. Here we report on the iron mineralogy of dust-source samples from the Bodélé Depression (Chad, north-central Africa), which is estimated to be Earth's most prolific dust producer and may be a key contributor to the global radiative budget of the atmosphere as well as to long-range nutrient transport to the Amazon Basin. By using a combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy, we document the abundance and relative amounts of goethite, hematite, and magnetite in dust-source samples from the Bodélé Depression. The partition between hematite and goethite is important to know to improve models for the radiative effects of ferric oxide minerals in mineral dust aerosols. The combination of methods shows (1) the dominance of goethite over hematite in the source sediments, (2) the abundance and occurrences of their nanosize components, and (3) the ubiquity of magnetite, albeit in small amounts. Dominant goethite and subordinate hematite together compose about 2% of yellow-reddish dust-source sediments from the Bodélé Depression and contribute strongly to diminution of reflectance in bulk samples. These observations imply that dust plumes from the Bodélé Depression that are derived from goethite-dominated sediments strongly absorb solar radiation. The presence of ubiquitous magnetite (0.002-0.57 wt%) is also noteworthy for its potentially higher solubility relative to ferric oxide and for its small sizes, including PM bioavailability to marine and terrestrial ecosystems.

  18. High field superconductor development and understanding project, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Larbalestier, David C.; Lee, Peter J.

    2009-07-15

    Over 25 years the Applied Superconductivity Center at the University of Wisconsin-Madison provided a vital technical resource to the High Energy Physics community covering development in superconducting strand for HEP accelerator magnet development. In particular the work of the group has been to develop the next generation of high field superconductors for high field application. Grad students Mike Naus, Chad Fischer, Arno Godeke and Matt Jewell improved our understanding of the microstructure and microchemistry of Nb3Sn and their impact on the physical and mechanical properties. The success of this work has led to the continued funding of this work at the ASC after it moved to the NHMFL and also to direct funding from BNL for some aspects of Nb3Sn cable evaluation.

  19. Häda taustauuringutega / Chad Terhune

    Index Scriptorium Estoniae

    Terhune, Chad

    2008-01-01

    Üha enam firmasid Ameerikas on hakanud tegema taustauuringuid peamiselt keskmise ja madalama tasandi töökohadele tulnud avalduste andjate kohta. Selleks kasutatakse mitmeid tööandjatele taustauuringuid pakkuvaid firmasid, millest üks on ChoicePoint. Ettevõte koostab töösoovija kohta digitaalse toimiku, mis sisaldab haridusdiplomeid, krediidiajalugu ning ka intervjuusid sõprade, endiste ülemuste ja kolleegidega. Vt. samas: Taustakontroll

  20. NEW INSIGHT INTO THE GEOLOGY OF THE CHAD BASIN

    African Journals Online (AJOL)

    exponent wfiicli is .usua[[_"y used in tlie cliaracterization qffractafls is used Here for geo[ogica[ mapping. 'Tliis was first done ... for qualitative description of the heterogeneity .... study lies between geographic latitudes 12° 001. N and 13° 30' N ...

  1. Recharging the Lake Chad: the Hydropolitics of National Security ...

    African Journals Online (AJOL)

    First Lady

    religious radicalism, has giving rise to terrorism. Recent estimate puts .... crisis suggests that the issue at stake is that of environmental deprivation projected by the ... Nigeria is in relative poverty, this translates to 17% in 6 years. Furthermore,.

  2. Template-Directed Crystallization of High Energy Materials

    Science.gov (United States)

    2014-04-01

    LONGER EMPLOYED BY YOUR ORGANIZATION. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of...using joint beam time awarded to Chad Stoltz (Indian Head), Kyle Ramos and Dan Hooks ( LANL ). This was a good learning opportunity, however, the

  3. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection.

    Science.gov (United States)

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V S; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-08-02

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  4. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    Directory of Open Access Journals (Sweden)

    Leo Swadling

    2016-08-01

    Full Text Available An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV infection, as an adjunct to newly developed directly-acting antivirals (DAA, or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3 vector and a modified vaccinia Ankara (MVA, encoding the non-structural proteins of HCV (NSmut, used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy, determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T

  5. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    Science.gov (United States)

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M. Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V. S.; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-01-01

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  6. High Resolution Simulations of Future Climate in West Africa Using a Variable-Resolution Atmospheric Model

    Science.gov (United States)

    Adegoke, J. O.; Engelbrecht, F.; Vezhapparambu, S.

    2013-12-01

    In previous work demonstrated the application of a var¬iable-resolution global atmospheric model, the conformal-cubic atmospheric model (CCAM), across a wide range of spatial and time scales to investigate the ability of the model to provide realistic simulations of present-day climate and plausible projections of future climate change over sub-Saharan Africa. By applying the model in stretched-grid mode the versatility of the model dynamics, numerical formulation and physical parameterizations to function across a range of length scales over the region of interest, was also explored. We primarily used CCAM to illustrate the capability of the model to function as a flexible downscaling tool at the climate-change time scale. Here we report on additional long term climate projection studies performed by downscaling at much higher resolutions (8 Km) over an area that stretches from just south of Sahara desert to the southern coast of the Niger Delta and into the Gulf of Guinea. To perform these simulations, CCAM was provided with synoptic-scale forcing of atmospheric circulation from 2.5 deg resolution NCEP reanalysis at 6-hourly interval and SSTs from NCEP reanalysis data uses as lower boundary forcing. CCAM 60 Km resolution downscaled to 8 Km (Schmidt factor 24.75) then 8 Km resolution simulation downscaled to 1 Km (Schmidt factor 200) over an area approximately 50 Km x 50 Km in the southern Lake Chad Basin (LCB). Our intent in conducting these high resolution model runs was to obtain a deeper understanding of linkages between the projected future climate and the hydrological processes that control the surface water regime in this part of sub-Saharan Africa.

  7. Atrial fibrillation

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    patients with atrial fibrillation managed in a referral hospital in Port Harcourt, southern Nigeria. ... treatment despite all the patients having moderate to high risk of stroke ... Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, ...

  8. High arch

    Science.gov (United States)

    Pes cavus; High foot arch ... High foot arches are much less common than flat feet. They are more likely to be caused ... difficult to fit into shoes. People who have high arches most often need foot support. A high ...

  9. The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis

    Science.gov (United States)

    Ibrahim, Sulaiman S.; Riveron, Jacob M.; Stott, Robert; Irving, Helen; Wondji, Charles S.

    2016-01-01

    Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control. Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre. The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools. PMID:26548743

  10. The cytochrome P450 CYP6P4 is responsible for the high pyrethroid resistance in knockdown resistance-free Anopheles arabiensis.

    Science.gov (United States)

    Ibrahim, Sulaiman S; Riveron, Jacob M; Stott, Robert; Irving, Helen; Wondji, Charles S

    2016-01-01

    Pyrethroid insecticides are the front line vector control tools used in bed nets to reduce malaria transmission and its burden. However, resistance in major vectors such as Anopheles arabiensis is posing a serious challenge to the success of malaria control. Herein, we elucidated the molecular and biochemical basis of pyrethroid resistance in a knockdown resistance-free Anopheles arabiensis population from Chad, Central Africa. Using heterologous expression of P450s in Escherichia coli coupled with metabolism assays we established that the over-expressed P450 CYP6P4, located in the major pyrethroid resistance (rp1) quantitative trait locus (QTL), is responsible for resistance to Type I and Type II pyrethroid insecticides, with the exception of deltamethrin, in correlation with field resistance profile. However, CYP6P4 exhibited no metabolic activity towards non-pyrethroid insecticides, including DDT, bendiocarb, propoxur and malathion. Combining fluorescent probes inhibition assays with molecular docking simulation, we established that CYP6P4 can bind deltamethrin but cannot metabolise it. This is possibly due to steric hindrance because of the large vdW radius of bromine atoms of the dihalovinyl group of deltamethrin which docks into the heme catalytic centre. The establishment of CYP6P4 as a partial pyrethroid resistance gene explained the observed field resistance to permethrin, and its inability to metabolise deltamethrin probably explained the high mortality from deltamethrin exposure in the field populations of this Sudano-Sahelian An. arabiensis. These findings describe the heterogeneity in resistance towards insecticides, even from the same class, highlighting the need to thoroughly understand the molecular basis of resistance before implementing resistance management/control tools.

  11. Rural Schools in Developing Countries: A Case of Donon Manga in Eastern Tandjile in Chad

    Science.gov (United States)

    Ndoutorlengar, Médard; Djangrang, Man-na; Mamgue, Bassinang; Yongsi, H. B. Nguendo; Groza, Octavian

    2014-01-01

    The schools in rural areas in developing countries are often confronted with difficulties which are, in general, related to poverty, the quantitative and qualitative insufficiency of the professionals and the organization. Consequently, every year, the examinations results are unsatisfactory playing on the curriculum and excellence in the…

  12. Chad – Dakar: Extraordinary Habré trial is litmus test for Pan-African justice

    NARCIS (Netherlands)

    Bouwknegt, Thijs

    2015-01-01

    From 20 July onwards, Chad’s previous despot, Hissène Habré, will be in the dock on charges of crimes against humanity, torture and war crimes before the Extraordinary African Chambers (EAC) in the Senegalese court system. His trial will be Africa’s first to proceed to trial under the guise of unive

  13. Connecting to the Umma through Islamic Relief: transnational Islamic NGOs in Chad

    NARCIS (Netherlands)

    Kaag, M.M.A.

    2011-01-01

    This paper argues that if the activities of Islamic NGOs from the Arab world in Africa are evaluated merely in terms of their local economic development impact, there is a risk of missing an important point. While it is true that the scope of these interventions and the amount of money involved are

  14. The socio-economic impact of the Lake Chad resettlement scheme ...

    African Journals Online (AJOL)

    AJL

    Full Length Research Paper ... environment is a reflection of the low level of awareness of the people about environmental impacts ... thisstudy being carried out about 5 years after the completion of ... First, an exhaustive checklist of impacts that such project. (resettlement scheme) can have on land and water resources as.

  15. Rural Schools in Developing Countries: A Case of Donon Manga in Eastern Tandjile in Chad

    Science.gov (United States)

    Ndoutorlengar, Médard; Djangrang, Man-na; Mamgue, Bassinang; Yongsi, H. B. Nguendo; Groza, Octavian

    2014-01-01

    The schools in rural areas in developing countries are often confronted with difficulties which are, in general, related to poverty, the quantitative and qualitative insufficiency of the professionals and the organization. Consequently, every year, the examinations results are unsatisfactory playing on the curriculum and excellence in the…

  16. Communications Channels in the Sahel Using Mauritania, Mali, Niger, and Chad as a Case Study

    Science.gov (United States)

    2007-05-01

    Page 60 of 107 Appendix B - Phone Card Distribution Chain Phone Card Provider Internet Cafes ...92 Malaysia 22,25 93 Comoros 22,50 - Zambia 22,50 95 Niger 24,50 - Seychelles 24,50 97 Morocco 24,83 98 Bhutan 25,00 - Côte d’Ivoire 25,00

  17. Prevalence of filariasis in symptomatic patients in Moyen Chari district, south of Chad.

    Science.gov (United States)

    Bregani, Enrico Rino; Balzarini, Laura; Mbaïdoum, Narassem; Rovellini, Angelo

    2007-07-01

    Filarial parasites infect an estimated 140 million people worldwide. Wuchereria bancrofti, Onchocerca volvulus, Loa loa and Mansonella perstans are responsible for most filarial infections in sub-Saharan Africa. We describe the prevalence and the clinical characteristics of filariasis in symptomatic patients in Goundi Sanitary district:167 patients were enrolled (99 men, 68 women). M. perstans microfilariae were isolated in peripheral blood in 164 cases, while Loa loa and Wuchereria bancrofti filariasis were diagnosed in only six and three cases, respectively. The most frequent filariasis observed in our study were due to M. perstans and L. loa, while the few cases of W. bancrofti filariasis seem to have been acquired abroad. No cases of O. volvulus were observed. Microfilarial burden was not related to symptoms, but a correlation between eosinophilia and pruritus was evident. No relationship was observed between eosinophils and symptoms. The prevalence observed in symptomatic patients could reflect the real prevalence of filariasis.

  18. High PRF high current switch

    Science.gov (United States)

    Moran, Stuart L.; Hutcherson, R. Kenneth

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  19. Delivering high-quality family planning services in crisis-affected settings II: results.

    Science.gov (United States)

    Curry, Dora Ward; Rattan, Jesse; Huang, Shuyuan; Noznesky, Elizabeth

    2015-02-04

    An estimated 43 million women of reproductive age experienced the effects of conflict in 2012. Already vulnerable from the insecurity of the emergency, women must also face the continuing risk of unwanted pregnancy but often are unable to obtain family planning services. The ongoing Supporting Access to Family Planning and Post-Abortion Care (SAFPAC) initiative, led by CARE, has provided contraceptives, including long-acting reversible contraceptives (LARCs), to refugees, internally displaced persons, and conflict-affected resident populations in Chad, the Democratic Republic of the Congo (DRC), Djibouti, Mali, and Pakistan. The project works through the Ministry of Health in 4 key areas: (1) competency-based training, (2) supply chain management, (3) systematic supervision, and (4) community mobilization to raise awareness and shift norms related to family planning. This article presents data on program results from July 2011 to December 2013 from the 5 countries. Project staff summarized monthly data from client registers using hard-copy forms and recorded the data electronically in Microsoft Excel for compilation and analysis. The initiative reached 52,616 new users of modern contraceptive methods across the 5 countries, ranging from 575 in Djibouti to 21,191 in Chad. LARCs have predominated overall, representing 61% of new modern method users. The percentage of new users choosing LARCs varied by country: 78% in the DRC, 72% in Chad, and 51% in Mali, but only 29% in Pakistan. In Djibouti, those methods were not offered in the country through SAFPAC during the period discussed here. In Chad, the DRC, and Mali, implants have been the most popular LARC method, while in Pakistan the IUD has been more popular. Use of IUDs, however, has comprised a larger share of the method mix over time in all 4 of these countries. These results to date suggest that it is feasible to work with the public sector in fragile, crisis-affected states to deliver a wide range of quality

  20. High Surplus Means High Profits?

    Institute of Scientific and Technical Information of China (English)

    Guo Yan

    2007-01-01

    @@ In recent years,China has been in the limelight worldwide due to its constant high trade surplus.Its trade surplus hit US$ 24.974 billion in August, a record high and an increase of US$ 624 million versus the previous month, according to the latest data from China Customs.

  1. High Tech

    OpenAIRE

    Manterola, Javier; Fernández Casado, S.A., Carlos

    1987-01-01

    "High Tech" is an architectural movement that emphasizes the technological dimension of the building as expression means. Its research includes the diverse structures composing the building: resistance, closing, services, distribution and communications. Its results are unequal since not all the buildings rising from this movement are high technology and already are other buildings not enrolled in this movement. Renzo Piano, Richard Rogers and Norman Foster are its main representatives.

  2. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard;

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...

  3. High Line

    DEFF Research Database (Denmark)

    Kiib, Hans

    2015-01-01

    At just over 10 meters above street level, the High Line extends three kilometers through three districts of Southwestern Manhattan in New York. It consists of simple steel construction, and previously served as an elevated rail line connection between Penn Station on 34th Street and the many....... The High Line project has been carried out as part of an open conversion strategy. The result is a remarkable urban architectural project, which works as a catalyst for the urban development of Western Manhattan. The greater project includes the restoration and reuse of many old industrial buildings...... in close proximity to the park bridge and new projects being added to fit the context. The outcome is a conglomeration of non-contemporary urban activities along the High Line, where mechanical workshops, small wholesale stores. etc. mix with new exclusive residential buildings, eminent cafés...

  4. High Line

    DEFF Research Database (Denmark)

    Kiib, Hans

    2015-01-01

    in close proximity to the park bridge and new projects being added to fit the context. The outcome is a conglomeration of non-contemporary urban activities along the High Line, where mechanical workshops, small wholesale stores. etc. mix with new exclusive residential buildings, eminent cafés......At just over 10 meters above street level, the High Line extends three kilometers through three districts of Southwestern Manhattan in New York. It consists of simple steel construction, and previously served as an elevated rail line connection between Penn Station on 34th Street and the many...... factories and warehouses on Gansevoort Street. Today the High Line is a beautiful park covered with new tiles, viewing platforms and smaller recreational areas. The park bridge has simple, uniform, urban fittings and features a variety of flowering plants, grasses, shrubs and trees from around the world...

  5. High Turbulence

    CERN Multimedia

    EuHIT, Collaboration

    2015-01-01

    As a member of the EuHIT (European High-Performance Infrastructures in Turbulence - see here) consortium, CERN is participating in fundamental research on turbulence phenomena. To this end, the Laboratory provides European researchers with a cryogenic research infrastructure (see here), where the first tests have just been performed.

  6. Effect of Metabolic Syndrome on Risk Stratification for Left Atrial or Left Atrial Appendage Thrombus Formation in Patients with Nonvalvular Atrial Fibrillation

    Science.gov (United States)

    Chen, Yu-Yang; Liu, Qi; Liu, Li; Shu, Xiao-Rong; Su, Zi-Zhuo; Zhang, Hai-Feng; Nie, Ru-Qiong; Wang, Jing-Feng; Xie, Shuang-Lun

    2016-01-01

    Background: Metabolic syndrome (MS) is a risk factor for stroke and thromboembolism event. Left atrial or LA appendage (LA/LAA) thrombus is a surrogate of potential stroke. The relationship between MS and atrial thrombus remains unclear. In this study, we sought to investigate the effect of MS on risk stratification of LA/LAA thrombus formation in patients with nonvalvular atrial fibrillation (NVAF). Methods: This cross-sectional study enrolled 294 consecutive NVAF patients without prior anticoagulant and lipid-lowering therapies. LA/LAA thrombus was determined by transesophageal echocardiography. Risk assessment of LA/LAA thrombus was performed using the CHADS2, CHA2DS2-VASc, MS, CHADS2-MS, and CHA2DS2-VASc-MS scores. Logistic regression analyses were performed to determine which factors were significantly related to LA/LAA thrombus. Odds ratio (OR) including 95% confidence interval was also calculated. The predictive powers of different scores for the risk of LA/LAA thrombus were represented by C-statistics and compared by receiver operating characteristic (ROC) analysis. Results: LA/LAA thrombi were identified in 56 patients (19.0%). Logistic analysis showed that MS was the strongest risk factor for LA/LAA thrombus in NVAF patients (OR = 14.698, P < 0.001). ROC curve analyses revealed that the C-statistics of CHADS2-MS and CHA2DS2-VASc-MS was significantly higher than those of CHADS2 and CHA2DS2-VASc scores (CHADS2-MS vs. CHADS2, 0.807 vs. 0.726, P = 0.0019). Furthermore, MS was helpful for identifying individuals with a high risk of LA/LAA thrombus in the population with a low risk of stroke (CHADS2 or CHA2DS2-VASc score = 0). Conclusions: MS is associated with LA/LAA thrombus risk in patients with NVAF. In addition to the CHADS2 and CHA2DS2-VASc scores, the CHADS2-MS and CHA2DS2-VASc-MS scores provide additional information on stroke risk assessment. PMID:27748329

  7. High efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, G.

    1984-05-18

    The surgeon wants to have phlebograms with good contrast, which should show only the deep venous system and leaks to the superficial system, that means, the insufficient communicating veins and the inflow of the big and small saphenous vein into the deep vein must be visible. The most frequent causes for X-ray-prints of bad quality are: a too high position of the stowing, too high puncture at the back of the foot, bad focussing without showing the ankle joint or the popliteal region and too narrow sections of the X-ray-films as well as too late exposures with fullfilling of the total superficial venous system and extreme superposition on the film.

  8. High Energy $\

    CERN Multimedia

    2002-01-01

    This experiment is a high statistics exposure of BEBC filled with hydrogen to both @n and &bar.@n beams. The principal physics aims are : \\item a) The study of the production of charmed mesons and baryons using fully constrained events. \\end{enumerate} b) The study of neutral current interactions on the free proton. \\item c) Measurement of the cross-sections for production of exclusive final state N* and @D resonances. \\item d) Studies of hadronic final states in charged and neutral current reactions. \\item e) Measurement of inclusive charged current cross-sections and structure functions. \\end{enumerate}\\\\ \\\\ The neutrino flux is determined by monitoring the flux of muons in the neutrino shield. The Internal Picket Fence and External Muon Identifier of BEBC are essential parts of the experiment. High resolution cameras are used to search for visible decays of short-lived particles.

  9. High Tech

    Directory of Open Access Journals (Sweden)

    Manterola, Javier

    1987-02-01

    Full Text Available "High Tech" is an architectural movement that emphasizes the technological dimension of the building as expression means. Its research includes the diverse structures composing the building: resistance, closing, services, distribution and communications. Its results are unequal since not all the buildings rising from this movement are high technology and already are other buildings not enrolled in this movement. Renzo Piano, Richard Rogers and Norman Foster are its main representatives.

    "High Tech" es un movimiento arquitectónico que enfatiza la dimensión tecnológica del edificio como medio de expresión. Su investigación se fija en las diversas estructuras que configuran el edificio, la resistente, la de cerramiento, la de servicios, la de distribución y comunicaciones. Sus resultados son desiguales pues no todos los edificios que surgen de este movimiento son alta tecnología y muchos otros no inscritos en dicho movimiento sí lo son. Renzo Piano, Richard Rogers y Norman Foster son sus representantes más destacados.

  10. The use of mobile phones for demographic surveillance of mobile pastoralists and their animals in Chad: proof of principle

    Directory of Open Access Journals (Sweden)

    Vreni Jean-Richard

    2014-02-01

    Full Text Available Background: Demographic information is foundational for the planning and management of social programmes, in particular health services. The existing INDEPTH network surveillance sites are limited to coverage of sedentary populations. Including mobile populations in this approach would be expensive, time consuming and possibly low in accuracy. Very little is known about the demography of mobile pastoralists and their animals, so innovative approaches are urgently needed. Objective: To test and evaluate a mobile demographic surveillance system for mobile pastoralist households, including livestock herds, using mobile phones. Design: Mobile pastoralist camps were monitored (10 for 12 months and 10 for 18 months using biweekly mobile phone calls with camp leaders and their wives to conduct interviews about the households and livestock. The collected information was validated through personal visits, GPS data and a livestock demographic model. Results: The study showed the feasibility of mobile phone surveillance for mobile pastoralist camps, providing usable, valid information on human and livestock population structures, pregnancy outcomes and herd dynamics, as well as migration patterns. The approach was low-cost and applicable with the existing local resources. Conclusion: Demographic surveillance in mobile populations is feasible using mobile phones. Expansion of the small-scale system into a full mobile demographic surveillance system is warranted and would likely lead to improved planning and provision of human and animal health care.

  11. Physico-Chemical Evaluation of Wastewater from Abattoir, Brewery, Soap and Oil Factories, at Moundou City in Southern Chad

    Directory of Open Access Journals (Sweden)

    Ahmatal Tidjanihisseine

    2016-01-01

    Full Text Available The discharge of industrial wastewater in the city of Moundou deteriorates the quality of surface and underground water and soils. In this study the physicochemical quality of industrial effluents was investigated in different seasons (summer, winter and rainy. Three sampling sites were used (Central Abattoir discharge, Cotontchad (soap and oil factory discharge, and Brewery discharge, for sampling from July 2013 to December 2014. The following physico-chemical parameters were determined: pH, Temperature, EC, dissolved oxygen, COD, BOD5, NO3,PO4,SO4. Also, the heavy metals: Cu, Cd, Mn, Ni, Pb, As, Zn, Cr, Fe, Al, was analyzed on spectrophotometers and results were compared with World Health Organization (WHO permissible limits. This study revealed that most parameters were much higher than the permissible limit for wastewater discharges:some parameters were to higher: pH (12,6, Temperature (37,8 °C, C.E (4270 µS/cm, organic matters: COD (1200 mg/l, SO4 (1280 mg/l, PO4(4460 mg/l, NO3 (63,6 mg/l, (Fe (63,34 mg/l, Zn (13,27 mg/l, Pb (4,0 mg/l, Cu (25,34 mg/l, Cd (31,78 mg/l, Cr (5,9 mg/l, Ni (39,5 mg/l. The study concludes that discharge of effluents by the companies; factory and materials from other anthropogenic sources severely pollute the Logone River with heavy metals and other pollutants. We recommended that each industry recycle its wastewater and put in place specific treatment plants, because pollutants to eliminate vary depending on the industry.

  12. Lipid-based nutrient supplements: how can they combat child malnutrition?

    Science.gov (United States)

    Dewey, Kathryn G; Arimond, Mary

    2012-01-01

    Kathryn Dewey and Mary Arimond discuss new research in PLOS Medicine that assesses the effect of blanket provision of ready-to-use supplementary food to children at high risk of malnutrition in Chad, and highlight some of the challenges of investigating the efficacy of supplementary foods for malnourished children.

  13. Atrial fibrillation: An analysis of etiology and management pattern in ...

    African Journals Online (AJOL)

    None of the patients had evidence of stroke risk evaluation in their notes and less than ... treatment despite all the patients having moderate to high risk of stroke from our ... Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, ...

  14. Lipid-based nutrient supplements: how can they combat child malnutrition?

    Directory of Open Access Journals (Sweden)

    Kathryn G Dewey

    Full Text Available Kathryn Dewey and Mary Arimond discuss new research in PLOS Medicine that assesses the effect of blanket provision of ready-to-use supplementary food to children at high risk of malnutrition in Chad, and highlight some of the challenges of investigating the efficacy of supplementary foods for malnourished children.

  15. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  16. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Hypertension (High Blood Pressure) KidsHealth > For Teens > Hypertension (High Blood Pressure) Print ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  17. High Blood Pressure

    Science.gov (United States)

    ... normal blood pressure 140/90 or higher is high blood pressure Between 120 and 139 for the top number, ... prehypertension. Prehypertension means you may end up with high blood pressure, unless you take steps to prevent it. High ...

  18. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  19. High Blood Cholesterol

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Cholesterol? To understand high blood cholesterol (ko-LES-ter- ... cholesterol from your body. What Is High Blood Cholesterol? High blood cholesterol is a condition in which ...

  20. High potassium level

    Science.gov (United States)

    Hyperkalemia; Potassium - high; High blood potassium ... There are often no symptoms with a high level of potassium. When symptoms do occur, they may include: Nausea Slow, weak, or irregular pulse Sudden collapse, when the heartbeat gets too ...

  1. High Blood Cholesterol Prevention

    Science.gov (United States)

    ... Million Hearts® WISEWOMAN Program Prevention and Management of High LDL Cholesterol: What You Can Do Recommend on ... like eating a healthy diet, can help prevent high cholesterol. High low-density lipoprotein (LDL) cholesterol increases ...

  2. High Blood Cholesterol

    Science.gov (United States)

    ... version of this page please turn Javascript on. High Blood Cholesterol What is High Blood Cholesterol? What is Cholesterol? Cholesterol is a ... heart disease. If Your Blood Cholesterol Is Too High Too much cholesterol in your blood is called ...

  3. High Performance Networks for High Impact Science

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  4. High speed, high current pulsed driver circuit

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, Christopher R.

    2017-03-21

    Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.

  5. High-Flying High-Poverty Schools

    Science.gov (United States)

    American Educator, 2013

    2013-01-01

    In discussing socioeconomic integration before audiences, the author is frequently asked: What about high-poverty schools that do work? Don't they suggest that economic segregation isn't much of a problem after all? High-poverty public schools that beat the odds paint a heartening story that often attracts considerable media attention. In 2000,…

  6. High Throughput Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Argonne?s high throughput facility provides highly automated and parallel approaches to material and materials chemistry development. The facility allows scientists...

  7. High Temperature Materials Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The High Temperature Materials Lab provides the Navy and industry with affordable high temperature materials for advanced propulsion systems. Asset List: Arc Melter...

  8. High pressure, high current, low inductance, high reliability sealed terminals

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

    2010-03-23

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  9. The effect of the level of aggression in the first grade classroom on the course and malleability of aggressive behavior into middle school.

    Science.gov (United States)

    Kellam, S G; Ling, X; Merisca, R; Brown, C H; Ialongo, N

    1998-01-01

    This paper is on the influences of the classroom context on the course and malleability of aggressive behavior from entrance into first grade through the transition into middle school. Nineteen public elementary schools participated in developmental epidemiologically based preventive trials in first and second grades, one of which was directed at reducing aggressive, disruptive behavior. At the start of first grade, schools and teachers were randomly assigned to intervention or control conditions. Children within each school were assigned sequentially to classrooms from alphabetized lists, followed by checking to insure balanced assignment based on kindergarten behavior. Despite these procedures, by the end of first quarter, classrooms within schools differed markedly in levels of aggressive behavior. Children were followed through sixth grade, where their aggressive behavior was rated by middle school teachers. Strong interactive effects were found on the risk of being highly aggressive in middle school between the level of aggressive behavior in the first grade classrooms and each boy's own level of aggressive, disruptive behavior in first grade. The more aggressive first grade boys who were in higher aggressive first grade classrooms were at markedly increased risk, compared both to the median first grade boys, and compared to aggressive males in lower aggressive first grade classrooms. Boys were already behaving more aggressively than girls in first grade; and no similar classroom aggression effect was found among girls, although girls' own aggressive behavior did place them at increased risk. The preventive intervention effect, already reported elsewhere to reduce aggressive behavior among the more aggressive males, appeared to do so by reducing high levels of classroom aggression. First grade males' own poverty level was associated with higher risk of being more aggressive, disruptive in first grade, and thereby increased their vulnerability to classroom

  10. High speed high dynamic range high accuracy measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  11. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Hypertension (High Blood Pressure) KidsHealth > For Teens > Hypertension (High Blood Pressure) A ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  12. High pressure technology 1994

    Energy Technology Data Exchange (ETDEWEB)

    Kapp, J.A.; Picqueuer, L.M. (eds.)

    1994-01-01

    This volume is divided into four sessions: fracture mechanics applications to high pressure vessels; high pressure code issues; high pressure design, analysis, and safety concerns; and military and other high pressure applications. Separate abstracts were prepared for eleven papers of this conference.

  13. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  14. High-current, high-frequency capacitors

    Science.gov (United States)

    Renz, D. D.

    1983-06-01

    The NASA Lewis high-current, high-frequency capacitor development program was conducted under a contract with Maxwell Laboratories, Inc., San Diego, California. The program was started to develop power components for space power systems. One of the components lacking was a high-power, high-frequency capacitor. Some of the technology developed in this program may be directly usable in an all-electric airplane. The materials used in the capacitor included the following: the film is polypropylene, the impregnant is monoisopropyl biphenyl, the conductive epoxy is Emerson and Cuming Stycast 2850 KT, the foil is aluminum, the case is stainless steel (304), and the electrode is a modified copper-ceramic.

  15. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  16. High Temperature, High Power Piezoelectric Composite Transducers

    Directory of Open Access Journals (Sweden)

    Hyeong Jae Lee

    2014-08-01

    Full Text Available Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  17. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor ... Islanders American Indian/Alaska Native Programs Older Adults Family Link Diabetes EXPO Upcoming Diabetes EXPOs EXPO Volunteer ...

  18. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day Diabetes Basics Home Symptoms Diagnosis America's Diabetes Challenge Type ...

  19. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor ... Index Low-Calorie Sweeteners Sugar and Desserts Fitness Exercise & Type 1 Diabetes Get Started Safely Get And ...

  20. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... 2 Diabetes Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High ... What Can I Drink? Fruit Dairy Food Tips Eating Out Quick Meal Ideas Snacks Nutrient Content Claims ...

  1. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & ...

  2. High blood pressure medications

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  3. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor ... Options for the Uninsured Medicare Medicaid & CHIP For Parents & Kids Safe at School Everyday Life Children and ...

  4. Causes of High Cholesterol

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Causes of High Cholesterol Updated:Jul 5,2017 If you have high ... and procedures related to heart disease and stroke. Cholesterol • Home • About Cholesterol • HDL, LDL, and Triglycerides • Causes ...

  5. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose ... Clinical Practice Guidelines Patient Education Materials Scientific Sessions Journals for Professionals Professional Books Patient Access to Research ...

  6. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To ... Index Low-Calorie Sweeteners Sugar and Desserts Fitness Exercise & Type 1 Diabetes Get Started Safely Get And ...

  7. High-Risk Pregnancy

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications High-Risk Pregnancy: Condition Information Skip sharing on social media links Share this: Page Content A high-risk pregnancy refers to anything that puts the ...

  8. High blood cholesterol levels

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000403.htm High blood cholesterol levels To use the sharing features ... stroke, and other problems. The medical term for high blood cholesterol is lipid disorder, hyperlipidemia, or hypercholesterolemia. ...

  9. High power, high beam quality regenerative amplifier

    Science.gov (United States)

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  10. Highly Ionized Envelopes of High Velocity Clouds

    CERN Document Server

    Zekis, Erin E

    2009-01-01

    We present recent results on highly ionized gas in Galactic High-Velocity Clouds (HVCs), originally surveyed in OVI (Sembach et al. 2003). In a new FUSE/HST survey of SiII/III/IV (Shull et al. 2009) toward 37 AGN, we detected SiIII (lambda 1206.500 A) absorption with a sky coverage fraction 81 +/- 5% (61 HVCs along 30 of 37 high-latitude sight lines). The SiIII (lambda 1206.500 A) line is typically 4-5 times stronger than OVI (lambda 1031.926 A). The mean HVC column density of perhaps 10^19 cm^-2 of low-metallicity (0.1 - 0.2 Z_sun) ionized gas in the low halo. Recent determinations of HVC distances allow us to estimate a total reservoir of ~10^8 M_sun. Estimates of infall velocities indicate an infall rate of around 1 M_sun yr^-1, comparable to the replenishment rate for star formation in the disk. HVCs appear to be sheathed by intermediate-temperature gas (10^4.0 - 10^4.5 K) detectable in SiIII and SiIV, as well as hotter gas seen in OVI and other high ions. To prepare for HST observations of 10 HVC-selecte...

  11. Treating High Blood Pressure

    Science.gov (United States)

    About High Blood Pressure Many people in the United States die from high blood pressure. This condition usually does not cause symptoms. Most ... until it is too late. A person has high blood pressure when the blood pushes against Visit your doctor ...

  12. High-temperature superconductors

    CERN Document Server

    Saxena, Ajay Kumar

    2010-01-01

    The present book aims at describing the phenomenon of superconductivity and high-temperature superconductors discovered by Bednorz and Muller in 1986. The book covers the superconductivity phenomenon, structure of high-Tc superconductors, critical currents, synthesis routes for high Tc materials, superconductivity in cuprates, the proximity effect and SQUIDs, theories of superconductivity and applications of superconductors.

  13. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical term for high blood glucose (blood sugar). High blood glucose happens when the body has too little insulin or when the body can't use insulin properly. What Causes Hyperglycemia? A number of things can cause hyperglycemia: ...

  14. Early College High Schools

    Science.gov (United States)

    Dessoff, Alan

    2011-01-01

    For at-risk students who stand little chance of going to college, or even finishing high school, a growing number of districts have found a solution: Give them an early start in college while they still are in high school. The early college high school (ECHS) movement that began with funding from the Bill and Melinda Gates Foundation 10 years ago…

  15. High performance systems

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, M.B. [comp.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  16. High Sensitivity, High Frequency and High Time Resolution Decimetric Spectroscope

    Science.gov (United States)

    Sawant, H. S.; Rosa, R. R.

    1990-11-01

    RESUMEN. Se ha desarrollado el primer espectroscopio decimetrico latino americano operando en una banda de 100 MHz con alta resoluci6n de fre- cuencia (100 KHz) y tiempo (10 ms), alrededor de cualquier centro de frecuencia en el intervalo de 2000-200 MHz. El prop6sito de esta nota es describir investigaciones solares y no solares que se planean, progra ma de investigaci6n y la situaci6n actual de desarrollo de este espectroscopio. ABSTRACT. First Latin American Decimetric Spectroscope operating over a band of 100 MHz with high resolution in frequency (100 KHz) and time (10 ms), around any center frequency in the range of 2000-200 MHz is being developed. The purpose of this note is to describe planned solar, and non-solar, research programmes and present status of development of this spectroscope. Keq wo : INSTRUMENTS - SPECTROSCOPY

  17. Photoproduction at High Energy and High Intensity

    CERN Multimedia

    2002-01-01

    The photon beam used for this programme is tagged and provides a large flux up to very high energies (150-200 GeV). It is also hadron-free, since it is obtained by a two-step conversion method. A spectrometer is designed to exploit this beam and to perform a programme of photoproduction with a high level of sensitivity (5-50 events/picobarn).\\\\ \\\\ Priority will be given to the study of processes exhibiting the point-like behaviour of the photon, especially deep inelastic Compton scattering. The spectrometer has two magnets. Charged tracks are measured by MWPC's located only in field-free regions. Three calorimeters provide a large coverage for identifying and measuring electrons and photons. An iron filter downstream identifies muons. Most of the equipment is existing and recuperated from previous experiments.

  18. High Precision Measurements Using High Frequency Signals

    CERN Document Server

    Jin, Aohan; Sakurai, Atsunori; Liu, Liang; Edman, Fredrik; Öwall, Viktor; Pullerits, Tonu; Karki, Khadga J

    2014-01-01

    Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5X10^8. In this letter, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example length, resistance, etc. Real time implementation of the technique can open up new methodologies of in-situ virtual metrology in material design.

  19. Space Based Infrared System High (SBIRS High)

    Science.gov (United States)

    2015-12-01

    Aviation Blvd Bldg 271 Los Angeles Air Force Base (LAAFB) El Segundo, CA 90245-2808 michael.guetlein@us.af.mil Phone: 310-653-3018 Fax: 310-653-4414 DSN...mission areas: Missile Warning , Missile Defense, Technical Intelligence and Battlespace Awareness. The constellation architecture for SBIRS High...Integrated Tactical Warning /Attack Assessment (ITW/AA) mission in November 2008 and technical intelligence mission in August 2009. The SBIRS GEO 1

  20. Technological Aspects: High Voltage

    CERN Document Server

    Faircloth, D C

    2013-01-01

    This paper covers the theory and technological aspects of high-voltage design for ion sources. Electric field strengths are critical to understanding high-voltage breakdown. The equations governing electric fields and the techniques to solve them are discussed. The fundamental physics of high-voltage breakdown and electrical discharges are outlined. Different types of electrical discharges are catalogued and their behaviour in environments ranging from air to vacuum are detailed. The importance of surfaces is discussed. The principles of designing electrodes and insulators are introduced. The use of high-voltage platforms and their relation to system design are discussed. The use of commercially available high-voltage technology such as connectors, feedthroughs and cables are considered. Different power supply technologies and their procurement are briefly outlined. High-voltage safety, electric shocks and system design rules are covered.

  1. High performance homes

    DEFF Research Database (Denmark)

    Beim, Anne; Vibæk, Kasper Sánchez

    2014-01-01

    Can prefabrication contribute to the development of high performance homes? To answer this question, this chapter defines high performance in more broadly inclusive terms, acknowledging the technical, architectural, social and economic conditions under which energy consumption and production occur....... Consideration of all these factors is a precondition for a truly integrated practice and as this chapter demonstrates, innovative project delivery methods founded on the manufacturing of prefabricated buildings contribute to the production of high performance homes that are cost effective to construct, energy...

  2. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  3. High performance homes

    DEFF Research Database (Denmark)

    Beim, Anne; Vibæk, Kasper Sánchez

    2014-01-01

    Can prefabrication contribute to the development of high performance homes? To answer this question, this chapter defines high performance in more broadly inclusive terms, acknowledging the technical, architectural, social and economic conditions under which energy consumption and production occur....... Consideration of all these factors is a precondition for a truly integrated practice and as this chapter demonstrates, innovative project delivery methods founded on the manufacturing of prefabricated buildings contribute to the production of high performance homes that are cost effective to construct, energy...

  4. High enthalpy gas dynamics

    CERN Document Server

    Rathakrishnan, Ethirajan

    2014-01-01

    This is an introductory level textbook which explains the elements of high temperature and high-speed gas dynamics. written in a clear and easy to follow style, the author covers all the latest developments in the field including basic thermodynamic principles, compressible flow regimes and waves propagation in one volume covers theoretical modeling of High Enthalpy Flows, with particular focus on problems in internal and external gas-dynamic flows, of interest in the fields of rockets propulsion and hypersonic aerodynamics High enthalpy gas dynamics is a compulsory course for aerospace engine

  5. High voltage engineering

    CERN Document Server

    Rizk, Farouk AM

    2014-01-01

    Inspired by a new revival of worldwide interest in extra-high-voltage (EHV) and ultra-high-voltage (UHV) transmission, High Voltage Engineering merges the latest research with the extensive experience of the best in the field to deliver a comprehensive treatment of electrical insulation systems for the next generation of utility engineers and electric power professionals. The book offers extensive coverage of the physical basis of high-voltage engineering, from insulation stress and strength to lightning attachment and protection and beyond. Presenting information critical to the design, selec

  6. High assurance services computing

    CERN Document Server

    2009-01-01

    Covers service-oriented technologies in different domains including high assurance systemsAssists software engineers from industry and government laboratories who develop mission-critical software, and simultaneously provides academia with a practitioner's outlook on the problems of high-assurance software development

  7. High Nitrogen Stainless Steel

    Science.gov (United States)

    2011-07-19

    Kiev, 1993. 7. High Nitrogen Steels, edited by M. Kikuchi and Y. Mishima , Vol. 36, No. 7, Iron and Steel Institute of Japan Inernational, Tokyo...the Corrosion of Iron and Steels,” High Nitrogen Steels, edited by M. Kikuchi and Y. Mishima , Vol. 36, No. 7, Iron and Steel Institute of Japan

  8. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day Diabetes Basics Home Symptoms Diagnosis America's Diabetes Challenge Type 1 Type 2 Facts About Type 2 Enroll in ...

  9. High coking value pitch

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Douglas J.; Chang, Ching-Feng; Lewis, Irwin C.; Lewis, Richard T.

    2014-06-10

    A high coking value pitch prepared from coal tar distillate and has a low softening point and a high carbon value while containing substantially no quinoline insolubles is disclosed. The pitch can be used as an impregnant or binder for producing carbon and graphite articles.

  10. High-pressure apparatus

    NARCIS (Netherlands)

    Schepdael, van L.J.M.; Bartels, P.V.; Berg, van den R.W.

    1999-01-01

    The invention relates to a high-pressure device (1) having a cylindrical high-pressure vessel (3) and prestressing means in order to exert an axial pressure on the vessel. The vessel (3) can have been formed from a number of layers of composite material, such as glass, carbon or aramide fibers which

  11. Highly interactive distributed visualization

    NARCIS (Netherlands)

    Scarpa, M.; Belleman, R.G.; Sloot, P.M.A.; de Laat, C.T.A.M.

    2006-01-01

    We report on our iGrid2005 demonstration, called the "Dead Cat Demo"; an example of a highly interactive augmented reality application consisting of software services distributed over a wide-area, high-speed network. We describe our design decisions, analyse the implications of the design on applica

  12. High-Conflict Divorce.

    Science.gov (United States)

    Johnston, Janet R.

    1994-01-01

    Reviews available research studies of high-conflict divorce and its effects on children. Factors believed to contribute to high-conflict divorce are explored, and a model of their interrelationships is proposed. Dispute resolution, intervention, and prevention programs are discussed, and implications for social policy are outlined. (SLD)

  13. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Type 2 Diabetes Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High ... Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes ... Tips Eating Out Quick Meal Ideas Snacks Nutrient Content Claims ...

  14. High and Dry

    Science.gov (United States)

    Johnson, Robert L.

    2005-01-01

    High-performance schools are facilities that improve the learning environment while saving energy, resources and money. Creating a high-performance school requires an integrated design approach. Key systems--including lighting, HVAC, electrical and plumbing--must be considered from the beginning of the design process. According to William H.…

  15. High density photovoltaic

    Energy Technology Data Exchange (ETDEWEB)

    Haigh, R.E.; Jacobson, G.F.; Wojtczuk, S. [Spire Corp., Bedford, MA (United States)

    1997-10-14

    Photovoltaic technology can directly generate high voltages in a solid state material through the series interconnect of many photovoltaic diodes. We are investigating the feasibility of developing an electrically isolated, high-voltage power supply using miniature photovoltaic devices that convert optical energy to electrical energy.

  16. High School Oceanography.

    Science.gov (United States)

    Falmouth Public Schools, MA.

    This book is a compilation of a series of papers designed to aid high school teachers in organizing a course in oceanography for high school students. It consists of twelve papers, with references, covering each of the following: (1) Introduction to Oceanography, (2) Geology of the Ocean, (3) The Continental Shelves, (4) Physical Properties of Sea…

  17. Proxmox high availability

    CERN Document Server

    Cheng, Simon MC

    2014-01-01

    If you want to know the secrets of virtualization and how to implement high availability on your services, this is the book for you. For those of you who are already using Proxmox, this book offers you the chance to build a high availability cluster with a distributed filesystem to further protect your system from failure.

  18. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  19. Phononic High Harmonic Generation

    CERN Document Server

    Ganesan, Adarsh; Seshia, Ashwin A

    2016-01-01

    This paper reports the first experimental evidence for phononic low-order to high-order harmonic conversion leading to high harmonic generation. Similar to parametric resonance, phononic high harmonic generation is also mediated by a threshold dependent instability of a driven phonon mode. Once the threshold for instability is met, a cascade of harmonic generation processes is triggered. Firstly, the up-conversion of first harmonic phonons into second harmonic phonons is established. Subsequently, the down-conversion of second harmonic phonons into first harmonic phonons and conversion of first and second harmonic phonons into third harmonic phonons occur. On the similar lines, an eventual conversion of third harmonic phonons to high orders is also observed to commence. This surprising physical pathway for phononic low-order to high-order harmonic conversion may find general relevance to other physical systems.

  20. High performance germanium MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Saraswat, Krishna [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)]. E-mail: saraswat@stanford.edu; Chui, Chi On [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Krishnamohan, Tejas [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Kim, Donghyun [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Nayfeh, Ammar [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Pethe, Abhijit [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2006-12-15

    Ge is a very promising material as future channel materials for nanoscale MOSFETs due to its high mobility and thus a higher source injection velocity, which translates into higher drive current and smaller gate delay. However, for Ge to become main-stream, surface passivation and heterogeneous integration of crystalline Ge layers on Si must be achieved. We have demonstrated growth of fully relaxed smooth single crystal Ge layers on Si using a novel multi-step growth and hydrogen anneal process without any graded buffer SiGe layer. Surface passivation of Ge has been achieved with its native oxynitride (GeO {sub x}N {sub y} ) and high-permittivity (high-k) metal oxides of Al, Zr and Hf. High mobility MOSFETs have been demonstrated in bulk Ge with high-k gate dielectrics and metal gates. However, due to their smaller bandgap and higher dielectric constant, most high mobility materials suffer from large band-to-band tunneling (BTBT) leakage currents and worse short channel effects. We present novel, Si and Ge based heterostructure MOSFETs, which can significantly reduce the BTBT leakage currents while retaining high channel mobility, making them suitable for scaling into the sub-15 nm regime. Through full band Monte-Carlo, Poisson-Schrodinger and detailed BTBT simulations we show a dramatic reduction in BTBT and excellent electrostatic control of the channel, while maintaining very high drive currents in these highly scaled heterostructure DGFETs. Heterostructure MOSFETs with varying strained-Ge or SiGe thickness, Si cap thickness and Ge percentage were fabricated on bulk Si and SOI substrates. The ultra-thin ({approx}2 nm) strained-Ge channel heterostructure MOSFETs exhibited >4x mobility enhancements over bulk Si devices and >10x BTBT reduction over surface channel strained SiGe devices.

  1. High Antibiotic Consumption

    DEFF Research Database (Denmark)

    Malo, Sara; José Rabanaque, María; Feja, Cristina;

    2014-01-01

    with highest consumption) were responsible for 21% of the total DDD consumed and received ≥6 packages per year. Elderly adults (≥60 years) and small children (0-9 years) were those exposed to the highest volume of antibiotics and with the most frequent exposure, respectively. Heavy users received a high...... proportion of antibiotics not recommended as first choice in primary health care. In conclusion, heavy antibiotic users consisted mainly of children and old adults. Inappropriate overuse of antibiotics (high quantity, high frequency, and inappropriate antibiotic choice) leads to a substantial risk...

  2. High voltage test techniques

    CERN Document Server

    Kind, Dieter

    2001-01-01

    The second edition of High Voltage Test Techniques has been completely revised. The present revision takes into account the latest international developments in High Voltage and Measurement technology, making it an essential reference for engineers in the testing field.High Voltage Technology belongs to the traditional area of Electrical Engineering. However, this is not to say that the area has stood still. New insulating materials, computing methods and voltage levels repeatedly pose new problems or open up methods of solution; electromagnetic compatibility (EMC) or components and systems al

  3. High Efficiency, High Performance Clothes Dryer

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pescatore; Phil Carbone

    2005-03-31

    This program covered the development of two separate products; an electric heat pump clothes dryer and a modulating gas dryer. These development efforts were independent of one another and are presented in this report in two separate volumes. Volume 1 details the Heat Pump Dryer Development while Volume 2 details the Modulating Gas Dryer Development. In both product development efforts, the intent was to develop high efficiency, high performance designs that would be attractive to US consumers. Working with Whirlpool Corporation as our commercial partner, TIAX applied this approach of satisfying consumer needs throughout the Product Development Process for both dryer designs. Heat pump clothes dryers have been in existence for years, especially in Europe, but have not been able to penetrate the market. This has been especially true in the US market where no volume production heat pump dryers are available. The issue has typically been around two key areas: cost and performance. Cost is a given in that a heat pump clothes dryer has numerous additional components associated with it. While heat pump dryers have been able to achieve significant energy savings compared to standard electric resistance dryers (over 50% in some cases), designs to date have been hampered by excessively long dry times, a major market driver in the US. The development work done on the heat pump dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) 40-50% energy savings on large loads with 35 F lower fabric temperatures and similar dry times; (2) 10-30 F reduction in fabric temperature for delicate loads with up to 50% energy savings and 30-40% time savings; (3) Improved fabric temperature uniformity; and (4) Robust performance across a range of vent restrictions. For the gas dryer development, the concept developed was one of modulating the gas flow to the dryer throughout the dry cycle. Through heat modulation in a

  4. High Efficiency, High Performance Clothes Dryer

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pescatore; Phil Carbone

    2005-03-31

    This program covered the development of two separate products; an electric heat pump clothes dryer and a modulating gas dryer. These development efforts were independent of one another and are presented in this report in two separate volumes. Volume 1 details the Heat Pump Dryer Development while Volume 2 details the Modulating Gas Dryer Development. In both product development efforts, the intent was to develop high efficiency, high performance designs that would be attractive to US consumers. Working with Whirlpool Corporation as our commercial partner, TIAX applied this approach of satisfying consumer needs throughout the Product Development Process for both dryer designs. Heat pump clothes dryers have been in existence for years, especially in Europe, but have not been able to penetrate the market. This has been especially true in the US market where no volume production heat pump dryers are available. The issue has typically been around two key areas: cost and performance. Cost is a given in that a heat pump clothes dryer has numerous additional components associated with it. While heat pump dryers have been able to achieve significant energy savings compared to standard electric resistance dryers (over 50% in some cases), designs to date have been hampered by excessively long dry times, a major market driver in the US. The development work done on the heat pump dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) 40-50% energy savings on large loads with 35 F lower fabric temperatures and similar dry times; (2) 10-30 F reduction in fabric temperature for delicate loads with up to 50% energy savings and 30-40% time savings; (3) Improved fabric temperature uniformity; and (4) Robust performance across a range of vent restrictions. For the gas dryer development, the concept developed was one of modulating the gas flow to the dryer throughout the dry cycle. Through heat modulation in a

  5. High-Definition Medicine.

    Science.gov (United States)

    Torkamani, Ali; Andersen, Kristian G; Steinhubl, Steven R; Topol, Eric J

    2017-08-24

    The foundation for a new era of data-driven medicine has been set by recent technological advances that enable the assessment and management of human health at an unprecedented level of resolution-what we refer to as high-definition medicine. Our ability to assess human health in high definition is enabled, in part, by advances in DNA sequencing, physiological and environmental monitoring, advanced imaging, and behavioral tracking. Our ability to understand and act upon these observations at equally high precision is driven by advances in genome editing, cellular reprogramming, tissue engineering, and information technologies, especially artificial intelligence. In this review, we will examine the core disciplines that enable high-definition medicine and project how these technologies will alter the future of medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... to Give Close Are You at Risk? Home Prevention Diagnosing Diabetes and Learning About Prediabetes Type 2 Diabetes Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity ...

  7. High cholesterol - children

    Science.gov (United States)

    ... and dressings Avoid foods that are high in saturated fat and added sugar Use skim milk or low- ... with other risk factors. Have family history of cardiovascular disease. Have one or more risk factors for ...

  8. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing ...

  9. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... an Employer Options for the Uninsured Medicare Medicaid & CHIP For Parents & Kids Safe at School Everyday Life ... blood sugar). High blood glucose happens when the body has too little insulin or when the body ...

  10. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing ...

  11. High-Tech Architecture

    Directory of Open Access Journals (Sweden)

    Özlem Eşsiz

    1999-05-01

    Full Text Available The technological development in building and construction area, bring with the new construction systems and the new products. The aim of this study is to define the High Tech concept, and set the common and basic characteristics of High Tech applications. During 1970’s High Tech was born and developed in Britain. Especially British Architects Richard Rogers, Michael Hopkins, Norman Foster, Nicholas Grimshaw and Ian Ritchie are the leaders of this style. Their architecture show the machine aesthetic and use of industrial revoluation materials such as glass and steel. The reasons for wide usage of this technology in building constructions are; the ease of renewing the structural and installation systems by the changing technology and giving monumentality to the prestige buildings. High Tech building which we have many examples of give their occupants a lot of opportunities and also they can adapt itself to the time.

  12. Landforms of High Mountains

    Directory of Open Access Journals (Sweden)

    Derek A. McDougall

    2016-05-01

    Full Text Available Reviewed: Landforms of High Mountains. By Alexander Stahr and Ewald Langenscheidt. Heidelberg, Germany: Springer, 2015. viii + 158 pp. US$ 129.99. Also available as an e-book. ISBN 978-3-642-53714-1.

  13. Poole High Street study

    OpenAIRE

    Kilburn, David

    2007-01-01

    A presentation given to key decision makers within Poole to improve the retail offer in Poole High Street and leverage the benefit of improved town planning and the introduction of quality retail companies.

  14. High temperature battery. Hochtemperaturbatterie

    Energy Technology Data Exchange (ETDEWEB)

    Bulling, M.

    1992-06-04

    To prevent heat losses of a high temperature battery, it is proposed to make the incoming current leads in the area of their penetration through the double-walled insulating housing as thermal throttle, particularly spiral ones.

  15. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... already been diagnosed with high blood pressure. Try yoga and meditation. Yoga and meditation not only can strengthen your body ... Accessed Sept. 21, 2015. Hu B, et al. Effects of psychological stress on hypertension in middle-aged ...

  16. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... and Learning About Prediabetes Type 2 Diabetes Risk Test Lower Your Risk Healthy Eating Overweight Smoking High ... excused. 86 million Americans have prediabetes. Take the test. Know where you stand. sticky en -- Chef Ronaldo's ...

  17. High Plains Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base, the extent, and the 1991 potentiometric surface (i.e. altitude of the water table) of the High...

  18. High-mix insulins

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2015-01-01

    Full Text Available Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use.

  19. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  20. Microwave Radiometer - high frequency

    Data.gov (United States)

    Oak Ridge National Laboratory — The Microwave Radiometer-High Frequency (MWRHF) provides time-series measurements of brightness temperatures from two channels centered at 90 and 150 GHz. These two...

  1. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... and Learning About Prediabetes Type 2 Diabetes Risk Test Lower Your Risk Healthy Eating Overweight Smoking High ... You at Risk? Diagnosis Lower Your Risk Risk Test Alert Day Prediabetes My Health Advisor Tools to ...

  2. Responsive design high performance

    CERN Document Server

    Els, Dewald

    2015-01-01

    This book is ideal for developers who have experience in developing websites or possess minor knowledge of how responsive websites work. No experience of high-level website development or performance tweaking is required.

  3. HIGH-ALTITUDE ILLNESS

    Directory of Open Access Journals (Sweden)

    Dwitya Elvira

    2015-05-01

    Full Text Available AbstrakHigh-altitude illness (HAI merupakan sekumpulan gejala paru dan otak yang terjadi pada orang yang baru pertama kali mendaki ke ketinggian. HAI terdiri dari acute mountain sickness (AMS, high-altitude cerebral edema (HACE dan high-altitude pulmonary edema (HAPE. Tujuan tinjauan pustaka ini adalah agar dokter dan wisatawan memahami risiko, tanda, gejala, dan pengobatan high-altitude illness. Perhatian banyak diberikan terhadap penyakit ini seiring dengan meningkatnya popularitas olahraga ekstrim (mendaki gunung tinggi, ski dan snowboarding dan adanya kemudahan serta ketersediaan perjalanan sehingga jutaan orang dapat terpapar bahaya HAI. Di Pherice, Nepal (ketinggian 4343 m, 43% pendaki mengalami gejala AMS. Pada studi yang dilakukan pada tempat wisata di resort ski Colorado, Honigman menggambarkan kejadian AMS 22% pada ketinggian 1850 m sampai 2750 m, sementara Dean menunjukkan 42% memiliki gejala pada ketinggian 3000 m. Aklimatisasi merupakan salah satu tindakan pencegahan yang dapat dilakukan sebelum pendakian, selain beberapa pengobatan seperti asetazolamid, dexamethasone, phosopodiestrase inhibitor, dan ginko biloba.Kata kunci: high-altitude illness, acute mountain sickness, edema cerebral, pulmonary edema AbstractHigh-altitude illness (HAI is symptoms of lung and brain that occurs in people who first climb to altitude. HAI includes acute mountain sickness (AMS, high-altitude cerebral edema (HACE and high altitude pulmonary edema (HAPE. The objective of this review was to understand the risks, signs, symptoms, and treatment of high-altitude illness. The attention was given to this disease due to the rising popularity of extreme sports (high mountain climbing, skiing and snowboarding and the ease and availability of the current travelling, almost each year, millions of people could be exposed to the danger of HAI. In Pherice, Nepal (altitude 4343 m, 43% of climbers have symptoms of AMS. Furthermore, in a study conducted at sites in

  4. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  5. High surface area, high permeability carbon monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  6. High voltage engineering fundamentals

    CERN Document Server

    Kuffel, E; Hammond, P

    1984-01-01

    Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

  7. Adaptation to High Altitude

    OpenAIRE

    1984-01-01

    Hypoxia is inconsequential for physiologically fit persons below an effective altitude of 2640 metres. At higher altitudes, the adaptation is brought about by four main factors, viz., hyperventilation, increased diffusion of oxygen across alveolar membrane, erythrocythemia and maintenance of body hydration. Carbon dioxide sensitivity is markedly elevated at high altitude, both in sojourners and acclimatized low-landers. The greater pulmonary diffusing capacity observed in high altitude native...

  8. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  9. High efficiency incandescent lighting

    Science.gov (United States)

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  10. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

    1994-01-01

    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  11. High energy astrophysical neutrinos

    OpenAIRE

    Athar, H.

    2002-01-01

    High energy neutrinos with energy typically greater than tens of thousands of GeV may originate from several astrophysical sources. The sources may include, for instance, our galaxy, the active centers of nearby galaxies, as well as possibly the distant sites of gamma ray bursts. I briefly review some aspects of production and propagation as well as prospects for observations of these high energy astrophysical neutrinos.

  12. High Altitude Cerebral Edema

    Science.gov (United States)

    1986-03-01

    such enzyme inhibition would favor the creation of a metabolic acidosis to offset the hypoxic respiratory alkalosis of high altitude hyperventilation...that some of their symptoms might be due to the early respiratory alkalosis seen upon arrival at high altitude. Unfortunately 23 out of the 30 subjects...i I Hamilton-16 was negative in all cases and normal respiratory excursions were seen. CSF chemistries and cell counts were normal. Houston and

  13. High Performance Concrete

    OpenAIRE

    Traian Oneţ

    2009-01-01

    The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  14. High throughput drug profiling

    OpenAIRE

    Entzeroth, Michael; Chapelain, Béatrice; Guilbert, Jacques; Hamon, Valérie

    2000-01-01

    High throughput screening has significantly contributed to advances in drug discovery. The great increase in the number of samples screened has been accompanied by increases in costs and in the data required for the investigated compounds. High throughput profiling addresses the issues of compound selectivity and specificity. It combines conventional screening with data mining technologies to give a full set of data, enabling development candidates to be more fully compared.

  15. High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Traian Oneţ

    2009-01-01

    Full Text Available The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  16. High Gradient Accelerator Research

    Energy Technology Data Exchange (ETDEWEB)

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  17. Kilburn High Road Revisited

    Directory of Open Access Journals (Sweden)

    Cristina Capineri

    2016-07-01

    Full Text Available Drawing on John Agnew’s (1987 theoretical framework for the analysis of place (location, locale and sense of place and on Doreen Massey’s (1991 interpretation of Kilburn High Road (London, the contribution develops an analysis of the notion of place in the case study of Kilburn High Road by comparing the semantics emerging from Doreen Massey’s interpretation of Kilburn High Road in the late Nineties with those from a selection of noisy and unstructured volunteered geographic information collected from Flickr photos and Tweets harvested in 2014–2015. The comparison shows how sense of place is dynamic and changing over time and explores Kilburn High Road through the categories of location, locale and sense of place derived from the qualitative analysis of VGI content and annotations. The contribution shows how VGI can contribute to discovering the unique relationship between people and place which takes the form given by Doreen Massey to Kilburn High Road and then moves on to the many forms given by people experiencing Kilburn High Road through a photo, a Tweet or a simple narrative. Finally, the paper suggests that the analysis of VGI content can contribute to detect the relevant features of street life, from infrastructure to citizens’ perceptions, which should be taken into account for a more human-centered approach in planning or service management.

  18. Adaptation to High Altitude

    Directory of Open Access Journals (Sweden)

    H. S. Nayar

    1984-10-01

    Full Text Available Hypoxia is inconsequential for physiologically fit persons below an effective altitude of 2640 metres. At higher altitudes, the adaptation is brought about by four main factors, viz., hyperventilation, increased diffusion of oxygen across alveolar membrane, erythrocythemia and maintenance of body hydration. Carbon dioxide sensitivity is markedly elevated at high altitude, both in sojourners and acclimatized low-landers. The greater pulmonary diffusing capacity observed in high altitude natives is well documented. RBC count, haemoglobin and haematocrit increase whereas arterial oxyhaemoglobin saturation percentage decreases at high altitude. Diuretics (Furosemide have no role in adaptation to high altitude and adequate body hydration must be maintained.The ultimate adaptive mechanisms occur at tissue level which facilitate the diffusion of oxygen from blood to tissue and its utilization. The work capacity decreases at high altitude and a relationship between load carried and speed of marching has been determined at various altitudes. Although altitude has an adverse effect on process of cold acclimatization, yet it is possible to induce cold acclimatization by exposing subjects to a temperature of 0° to -5°C for a period of three hours daily for three weeks. The caloric requirements increase at high altitudes and are 4,286 K Cal and 4,380 K Cal at 13000 feet (3950 m and 17000 feet (5170 m, respectively.

  19. Higher Childhood Peer Reports of Social Preference Mediates the Impact of the Good Behavior Game on Suicide Attempt.

    Science.gov (United States)

    Newcomer, Alison R; Roth, Kimberly B; Kellam, Sheppard G; Wang, Wei; Ialongo, Nicholas S; Hart, Shelley R; Wagner, Barry M; Wilcox, Holly C

    2016-02-01

    The Good Behavior Game (GBG) is a universal classroom-based preventive intervention directed at reducing early aggressive, disruptive behavior and improving children's social adaptation into the classroom. The GBG is one of the few universal preventive interventions delivered in early elementary school that has been shown to reduce the risk for future suicide attempts. This paper addresses one potential mechanism by which the GBG lowers the risk of later suicide attempt. In this study, we tested whether the GBG, by facilitating social adaptation into the classroom early on, including the level of social preference by classmates, thereby lowers future risk of suicide attempts. The measure of social adaptation is based on first and second grade peer reports of social preference ("which children do you like best?"; "which children don't you like?"). As part of the hypothesized meditational model, we examined the longitudinal association between childhood peer social preference and the risk of future suicide attempt, which has not previously been examined. Data were from an epidemiologically based randomized prevention trial, which tested the GBG among two consecutive cohorts of first grade children in 19 public schools and 41 classrooms. Results indicated that peer social preference partially mediated the relationship between the GBG and the associated reduction of risk for later suicide attempts by adulthood, specifically among children characterized by their first grade teacher as highly aggressive, disruptive. These results suggest that positive childhood peer relations may partially explain the GBG-associated reduction of risk for suicide attempts and may be an important and malleable protective factor for future suicide attempt.

  20. High Caloric Diet for ALS Patients: High Fat, High Carbohydrate or High Protein

    Directory of Open Access Journals (Sweden)

    Sarvin Sanaie

    2015-01-01

    Full Text Available ALS is a fatal motor neurodegenerative disease characterized by muscle atrophy and weakness, dysarthria, and dysphagia. The mean survival of ALS patients is three to five years, with 50% of those diagnosed dying within three years of onset (1. A multidisciplinary approach is crucial to set an appropriate plan for metabolic and nutritional support in ALS. Nutritional management incorporates a continuous assessment and implementation of dietary modifications throughout the duration of the disease. The nutritional and metabolic approaches to ALS should start when the diagnosis of ALS is made and should become an integral part of the continuous care to the patient, including nutritional surveillance, dietary counseling, management of dysphagia, and enteral nutrition when needed. Malnutrition and lean body mass loss are frequent findings in ALS patients necessitating comprehensive energy requirement assessment for these patients. Malnutrition is an independent prognostic factor for survival in ALS with a 7.7 fold increase in risk of death. Malnutrition is estimated to develop in one quarter to half of people with ALS (2. Adequate calorie and protein provision would diminish muscle loss in this vulnerable group of patients. Although appropriate amount of energy to be administered is yet to be established, high calorie diet is expected to be effective for potential improvement of survival; ALS patients do not normally receive adequate  intake of energy. A growing number of clinicians suspect that a high calorie diet implemented early in their disease may help people with ALS meet their increased energy needs and extend their survival. Certain high calorie supplements appear to be safe and well tolerated by people with ALS according to studies led by Universitäts klinikum Ulm's and, appear to stabilize body weight within 3 months. In a recent study by Wills et al., intake of high-carbohydrate low-fat supplements has been recommended in ALS patients (3

  1. High Temperature Capacitor Development

    Energy Technology Data Exchange (ETDEWEB)

    John Kosek

    2009-06-30

    The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. Commercial off-the-shelf electronics are not specified to meet these operating conditions. This is due to problems associated with all aspects of the electronics including the resistors and capacitors. With respect to capacitors, increasing temperature often significantly changes capacitance because of the strong temperature dependence of the dielectric constant. Higher temperatures also affect the equivalent series resistance (ESR). High-temperature capacitors usually have low capacitance values because of these dielectric effects and because packages are kept small to prevent mechanical breakage caused by thermal stresses. Electrolytic capacitors do not operate at temperatures above 150oC due to dielectric breakdown. The development of high-temperature capacitors to be used in a high-pressure high-temperature (HPHT) drilling environment was investigated. These capacitors were based on a previously developed high-voltage hybridized capacitor developed at Giner, Inc. in conjunction with a

  2. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  3. High Altitude and Heart

    Directory of Open Access Journals (Sweden)

    Murat Yalcin

    2011-04-01

    Full Text Available Nowadays, situations associated with high altitude such as mountaineering, aviation increasingly draw the attention of people. Gas pressure decreases and hypoxia is encountered when climbing higher. Physiological and pathological responses of human body to different heights are different. Therefore, physiological and pathological changes that may occur together with height and to know the clinical outcomes of these are important . Acute mountain sickness caused by high altitude and high altitude cerebral edema are preventable diseases with appropriate precautions. Atmospheric oxygen decreasing with height, initiates many adaptive mechanisms. These adaptation mechanisms and acclimatization vary widely among individuals because of reasons such as environmental factors, exercise and cold. High altitude causes different changes in the cardiovascular system with various mechanisms. Although normal individuals easily adapt to these changes, this situation can lead to undesirable results in people with heart disease. For this reason, it should be known the effective evaluation of the people with known heart disease before traveling to high altitude and the complications due to the changes with height and the recommendations can be made to these patients. [TAF Prev Med Bull 2011; 10(2.000: 211-222

  4. HIGH TEMPERATURE DISPLACEMENT SENSOR

    Institute of Scientific and Technical Information of China (English)

    Xu Longxiang; Zhang Jinyu; Schweitzer Gerhard

    2005-01-01

    A high temperature displacement sensor based on the principle of eddy-current is investigated. A new temperature compensation technique by using eddy-current effect is presented to satisfy the special requirement at high temperature up to 550℃. The experiment shows that the temperature compensation technique leads to good temperature stability for the sensors. The variation of the sensitivity as well as the temperature drift of the sensor with temperature compensation technique is only about 7.4% and 90~350 mV at 550℃ compared with that at room temperature, and that of the sensor without temperature compensation technique is about 31.2% and 2~3 V at 550℃ compared with that at room temperature. A new dynamic calibration method for the eddy-current displacement sensor is presented, which is very easy to be realized especially in high frequency and at high temperatures. The high temperature displacement sensors developed are successfully used at temperature up to 550℃ in a magnetic bearing system for more than 100 h.

  5. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  6. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  7. Highly Thermal Conductive Nanocomposites

    Science.gov (United States)

    Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)

    2015-01-01

    Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.

  8. High Resolution Laboratory Spectroscopy

    CERN Document Server

    Brünken, Sandra

    2016-01-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limita...

  9. High-tech entrepreneurship

    DEFF Research Database (Denmark)

    Bernasconi, Michel; Harris, Simon; Mønsted, Mette

    ; entrepreneurial finance; marketing technological innovations; and high-tech incubation management. Including case studies to give practical insights into genuine business examples, this comprehensive book has a distinctly 'real-world' focus throughout.Edited by a multi-national team, this comprehensive book......High-tech businesses form a crucial part of entrepreneurial activity - in some ways representing very typical examples of entrepreneurship, yet in some ways representing quite different challenges. The uncertainty in innovation and advanced technology makes it difficult to use conventional economic...... planning models, and also means that the management skills used in this area must be more responsive to issues of risk, uncertainty and evaluation than in conventional business opportunities. Whilst entrepreneurial courses do reflect the importance of high-tech businesses, they often lack the resources...

  10. High-conflict divorce.

    Science.gov (United States)

    Johnston, J R

    1994-01-01

    This article reviews available research studies of high-conflict divorce and its effects on children. Interparental conflict after divorce (defined as verbal and physical aggression, overt hostility, and distrust) and the primary parent's emotional distress are jointly predictive of more problematic parent-child relationships and greater child emotional and behavioral maladjustment. As a group, children of high-conflict divorce as defined above, especially boys, are two to four times more likely to be clinically disturbed in emotions and behavior compared with national norms. Court-ordered joint physical custody and frequent visitation arrangements in high-conflict divorce tend to be associated with poorer child outcomes, especially for girls. Types of intervention programs and social policy appropriate for these kinds of families are presented.

  11. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

    Following in the footsteps of its popular predecessors, High Power Microwaves, Third Edition continues to provide a wide-angle, integrated view of the field of high power microwaves (HPMs). This third edition includes significant updates in every chapter as well as a new chapter on beamless systems that covers nonlinear transmission lines. Written by an experimentalist, a theorist, and an applied theorist, respectively, the book offers complementary perspectives on different source types. The authors address: * How HPM relates historically and technically to the conventional microwave field * The possible applications for HPM and the key criteria that HPM devices have to meet in order to be applied * How high power sources work, including their performance capabilities and limitations * The broad fundamental issues to be addressed in the future for a wide variety of source types The book is accessible to several audiences. Researchers currently in the field can widen their understanding of HPM. Present or pot...

  12. Citing for High Impact

    CERN Document Server

    Shi, Xiaolin; McFarland, Daniel A

    2010-01-01

    The question of citation behavior has always intrigued scientists from various disciplines. While general citation patterns have been widely studied in the literature we develop the notion of citation projection graphs by investigating the citations among the publications that a given paper cites. We investigate how patterns of citations vary between various scientific disciplines and how such patterns reflect the scientific impact of the paper. We find that idiosyncratic citation patterns are characteristic for low impact papers; while narrow, discipline-focused citation patterns are common for medium impact papers. Our results show that crossing-community, or bridging citation patters are high risk and high reward since such patterns are characteristic for both low and high impact papers. Last, we observe that recently citation networks are trending toward more bridging and interdisciplinary forms.

  13. High availability IT services

    CERN Document Server

    Critchley, Terry

    2014-01-01

    This book starts with the basic premise that a service is comprised of the 3Ps-products, processes, and people. Moreover, these entities and their sub-entities interlink to support the services that end users require to run and support a business. This widens the scope of any availability design far beyond hardware and software. It also increases the potential for service failure for reasons beyond just hardware and software; the concept of logical outages. High Availability IT Services details the considerations for designing and running highly available ""services"" and not just the systems

  14. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  15. High strength alloys

    Science.gov (United States)

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  16. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  17. High-level verification

    CERN Document Server

    Lerner, Sorin; Kundu, Sudipta

    2011-01-01

    Given the growing size and heterogeneity of Systems on Chip (SOC), the design process from initial specification to chip fabrication has become increasingly complex. This growing complexity provides incentive for designers to use high-level languages such as C, SystemC, and SystemVerilog for system-level design. While a major goal of these high-level languages is to enable verification at a higher level of abstraction, allowing early exploration of system-level designs, the focus so far for validation purposes has been on traditional testing techniques such as random testing and scenario-based

  18. JUNOS High Availability

    CERN Document Server

    Sonderegger, James; Milne, Kieran; Palislamovic, Senad

    2009-01-01

    Whether your network is a complex carrier or just a few machines supporting a small enterprise, JUNOS High Availability will help you build reliable and resilient networks that include Juniper Networks devices. With this book's valuable advice on software upgrades, scalability, remote network monitoring and management, high-availability protocols such as VRRP, and more, you'll have your network uptime at the five, six, or even seven nines -- or 99.99999% of the time. Rather than focus on "greenfield" designs, the authors explain how to intelligently modify multi-vendor networks. You'll learn

  19. Clustering high dimensional data

    DEFF Research Database (Denmark)

    Assent, Ira

    2012-01-01

    High-dimensional data, i.e., data described by a large number of attributes, pose specific challenges to clustering. The so-called ‘curse of dimensionality’, coined originally to describe the general increase in complexity of various computational problems as dimensionality increases, is known...... to render traditional clustering algorithms ineffective. The curse of dimensionality, among other effects, means that with increasing number of dimensions, a loss of meaningful differentiation between similar and dissimilar objects is observed. As high-dimensional objects appear almost alike, new approaches...

  20. High Availability Electronics Standards

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, R.S.; /SLAC

    2006-12-13

    Availability modeling of the proposed International Linear Collider (ILC) predicts unacceptably low uptime with current electronics systems designs. High Availability (HA) analysis is being used as a guideline for all major machine systems including sources, utilities, cryogenics, magnets, power supplies, instrumentation and controls. R&D teams are seeking to achieve total machine high availability with nominal impact on system cost. The focus of this paper is the investigation of commercial standard HA architectures and packaging for Accelerator Controls and Instrumentation. Application of HA design principles to power systems and detector instrumentation are also discussed.

  1. High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also...... input to the cell then hydrogen is produced giving syngas. This syngas can then be further reacted to form hydrocarbon fuels and chemicals. Operating at high temperature gives much higher efficiencies than can be achieved with low temperature electrolysis. Current state of the art SOECs utilise a dense...

  2. Danish High Performance Concretes

    DEFF Research Database (Denmark)

    Nielsen, M. P.; Christoffersen, J.; Frederiksen, J.

    1994-01-01

    In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University...

  3. High School Press Freedom.

    Science.gov (United States)

    Maurer, Diana J.

    This report focuses on controversial articles written by the high school press, decisions made by the courts regarding students' press freedoms, and reactions to the articles and rulings. Particular attention is given to two rulings concerning censorship of articles about students' sexual atttiudes and activities, the issue of prior restraint of…

  4. High Performance Magnets

    Science.gov (United States)

    2000-03-29

    Our efforts in this project were focused on three different materials, namely; interstitial Sm-Fe carbides and nitrides, high energy product Nd2Fe14B ...magnets with MgO addition, and nanocomposite Nd2Fe14B /alpha-Fe consisting of a fine mixture of hard and soft phases. In the Sm-Fe carbides and

  5. High blood pressure - infants

    Science.gov (United States)

    ... Certain tumors Inherited conditions (problems that run in families) Thyroid problems Blood pressure rises as the baby grows. The average blood ... vomiting constantly Prevention Some causes of high blood pressure run in families. Talk to your provider before you get pregnant ...

  6. High-velocity clouds

    NARCIS (Netherlands)

    Wakker, BP; vanWoerden, H

    1997-01-01

    High-velocity clouds (HVCs) consist of neutral hydrogen (HI) at velocities incompatible with a simple model of differential galactic rotation; in practice one uses \\v(LSR)\\ greater than or equal to 90 km/s to define HVCs. This review describes the main features of the sky and velocity distributions,

  7. Energy at high altitude.

    Science.gov (United States)

    Hill, N E; Stacey, M J; Woods, D R

    2011-03-01

    For the military doctor, an understanding of the metabolic effects of high altitude (HA) exposure is highly relevant. This review examines the acute metabolic challenge and subsequent changes in nutritional homeostasis that occur when troops deploy rapidly to HA. Key factors that impact on metabolism include the hypoxic-hypobaric environment, physical exercise and diet. Expected metabolic changes include augmentation of basal metabolic rate (BMR), decreased availability of oxygen in peripheral metabolic tissues, reduction in VO2 max, increased glucose dependency and lactate accumulation during exercise. The metabolic demands of exercise at HA are crucial. Equivalent activity requires greater effort and more energy than it does at sea level. Soldiers working at HA show high energy expenditure and this may exceed energy intake significantly. Energy intake at HA is affected adversely by reduced availability, reduced appetite and changes in endocrine parameters. Energy imbalance and loss of body water result in weight loss, which is extremely common at HA. Loss of fat predominates over loss of fat-free mass. This state resembles starvation and the preferential primary fuel source shifts from carbohydrate towards fat, reducing performance efficiency. However, these adverse effects can be mitigated by increasing energy intake in association with a high carbohydrate ration. Commanders must ensure that individuals are motivated, educated, strongly encouraged and empowered to meet their energy needs in order to maximise mission-effectiveness.

  8. Preventing High Blood Pressure

    Science.gov (United States)

    ... Web Sites Division for Heart Disease and Stroke Prevention Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share Compartir By living a healthy lifestyle, you can help keep your blood pressure in ...

  9. High Blood Pressure Facts

    Science.gov (United States)

    ... More black women than men have high blood pressure. 2 Race of Ethnic Group Men (%) Women (%) African Americans 43.0 45.7 Mexican Americans 27.8 28.9 Whites 33.9 31.3 All 34.1 32.7 Top of Page Why Blood Pressure Matters View this graphic snapshot of blood pressure ...

  10. Nongrading the High School.

    Science.gov (United States)

    Jenkins, John M.

    1998-01-01

    Reviews the history of nongraded high schools, from Preston Search's pioneering efforts in Pueblo, Colorado, to early 1900s Dalton and Winnetka Plans and midcentury continuous-progress plans. Competency, not age, already determines participation in band, orchestra, choir, and athletics. Curricula should be based on the structure, methodology, and…

  11. High availability using virtualization

    CERN Document Server

    Calzolari, Federico

    2009-01-01

    High availability has always been one of the main problems for a data center. Till now high availability was achieved by host per host redundancy, a highly expensive method in terms of hardware and human costs. A new approach to the problem can be offered by virtualization. Using virtualization, it is possible to achieve a redundancy system for all the services running on a data center. This new approach to high availability allows to share the running virtual machines over the servers up and running, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The system (3RC) is based on a finite state machine with hysteresis, providing the possibility to restart each virtual machine over any physical host, or reinstall it from scratch. A complete infrastructure has been developed to install operating system and middleware in a few minutes. To virtualize the main servers of a data center, a new procedure has been developed to migrate physical to virtu...

  12. Highly oxidized superconductors

    Science.gov (United States)

    Morris, Donald E.

    1994-01-01

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

  13. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical ...

  14. Carthage High School Baseball.

    Science.gov (United States)

    Woodfin, Samantha, Ed.

    1995-01-01

    This is the third issue of the magazine to focus on baseball in Panola County (Texas). The issue salutes the Carthage High School baseball program during two periods of its history. The first period was the early 1940's under Coach E. B. Morrison, whose teams were State Finalists in 1941 and 1942. The second period covered is the era of Coach…

  15. High Blood Pressure Prevention

    Science.gov (United States)

    ... or "no added salt." Look for the sodium content in milligrams and the Percent Daily Value. Aim for foods that are less than 5 percent of the Daily Value of sodium. Foods with 20 percent or more Daily Value of sodium are considered high. To learn more about reading nutrition labels, see ...

  16. High Power Cryogenic Targets

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Smith

    2011-08-01

    The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

  17. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  18. High Density Matter

    Directory of Open Access Journals (Sweden)

    Stone J.R.

    2013-12-01

    Full Text Available The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has led to the necessary reliance on theoretical models. There remains great uncertainty in these models which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this contribution latest developments in construction of the Equation of State (EoS of high-density matter at zero and finite temperature assuming different composition of matter will be discussed. Critical comparison of model EoS with available experimental data from heavy ion collisions and observations on neutron stars, including gravitational mass, radii and cooling patterns and data on X-ray burst sources and low mass X-ray binaries are made. Fundamental differences between the EoS of low-density, high temperature matter, such as is created in heavy ion collisions and of high-density, low temperature compact objects is discussed.

  19. Highly Expressive Hakka Art

    Institute of Scientific and Technical Information of China (English)

    JENNIFER LIM

    1996-01-01

    SOUTHERN Jiangxi Province was the birthplace of the Hakka ethnic group and has since been the native home and main transfer hub for the spread of the nationality. The highly expressive art of the Hakkas, including folk songs in Xingguo, colored lantern performances in Shicheng, ancient

  20. High-Energy Physics.

    Science.gov (United States)

    Creutz, Michael

    1983-01-01

    Experimentalists in particle physics have long regarded computers as essential components of their apparatus. Theorists are now finding that significant advances in some areas can be accomplished only in partnership with a machine. Needs of experimentalists, interests of theorists, and specialized computers for high-energy experiments are…

  1. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... over the years led to verification of the important role of high blood pressure—especially in concert with ... is specific for that person will be an important key to improving prevention, ... an international team of investigators, funded in part by the NIH, ...

  2. Maintaining High Expectations

    Science.gov (United States)

    Williams, Roger; Williams, Sherry

    2014-01-01

    Author and husband, Roger Williams, is hearing and signs fluently, and author and wife, Sherry Williams, is deaf and uses both speech and signs, although she is most comfortable signing. As parents of six children--deaf and hearing--they are determined to encourage their children to do their best, and they always set their expectations high. They…

  3. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Scott, James; Boudreau, Kate; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom; Zhang, Shujun

    2009-01-01

    The current NASA Decadal mission planning effort has identified Venus as a significant scientific target for a surface in-situ sampling/analyzing mission. The Venus environment represents several extremes including high temperature (460 deg C), high pressure (9 MPa), and potentially corrosive (condensed sulfuric acid droplets that adhere to surfaces during entry) environments. This technology challenge requires new rock sampling tools for these extreme conditions. Piezoelectric materials can potentially operate over a wide temperature range. Single crystals, like LiNbO3, have a Curie temperature that is higher than 1000 deg C and the piezoelectric ceramics Bismuth Titanate higher than 600 deg C. A study of the feasibility of producing piezoelectric drills that can operate in the temperature range up to 500 deg C was conducted. The study includes the high temperature properties investigations of engineering materials and piezoelectric ceramics with different formulas and doping. The drilling performances of a prototype Ultrasonic/Sonic Drill/Corer (USDC) using high temperate piezoelectric ceramics and single crystal were tested at temperature up to 500 deg C. The detailed results of our study and a discussion of the future work on performance improvements are presented in this paper.

  4. High energy battery. Hochenergiebatterie

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, H.; Beyermann, G.; Bulling, M.

    1992-03-26

    In a high energy battery with a large number of individual cells in a housing with a cooling medium flowing through it, it is proposed that the cooling medium should be guided so that it only affects one or both sides of the cells thermally.

  5. Ghana's high forests

    NARCIS (Netherlands)

    Oduro, K.A.

    2016-01-01

    Deforestation and forest degradation in the tropics have been receiving both scientific and political attention in recent decades due to its impacts on the environment and on human livelihoods. In Ghana, the continuous decline of forest resources and the high demand for timber have raised stakeholde

  6. High temperature superconducting compounds

    Science.gov (United States)

    Goldman, Allen M.

    1992-11-01

    The major accomplishment of this grant has been to develop techniques for the in situ preparation of high-Tc superconducting films involving the use of ozone-assisted molecular beam epitaxy. The techniques are generalizable to the growth of trilayer and multilayer structures. Films of both the DyBa2Cu3O(7-x) and YBa2Cu3O(7-x) compounds as well as the La(2-x)Sr(x)CuO4 compound have been grown on the usual substrates, SrTiO3, YSZ, MgO, and LaAlO3, as well as on Si substrates without any buffer layer. A bolometer has been fabricated on a thermally isolated SiN substrate coated with YSZ, an effort carried out in collaboration with Honeywell Inc. The deposition process facilitates the fabrication of very thin and transparent films creating new opportunities for the study of superconductor-insulator transitions and the investigation of photo-doping with carriers of high temperature superconductors. In addition to a thin film technology, a patterning technology has been developed. Trilayer structures have been developed for FET devices and tunneling junctions. Other work includes the measurement of the magnetic properties of bulk single crystal high temperature superconductors, and in collaboration with Argonne National Laboratory, measurement of electric transport properties of T1-based high-Tc films.

  7. High blood pressure - children

    Science.gov (United States)

    ... number is the diastolic pressure. This measures the pressure in the arteries when the heart is at rest. Blood pressure ... Medical Professional Call your child's provider if home monitoring shows that your child's blood pressure is still high. Prevention Your child's provider will ...

  8. High-Sensitivity Spectrophotometry.

    Science.gov (United States)

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  9. High Brightness OLED Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, Jeffrey [OLEDWorks LLC; Kondakova, Marina [OLEDWorks LLC; Boroson, Michael [OLEDWorks LLC; Hamer, John [OLEDWorks LLC

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  10. High-resolution headlamp

    Science.gov (United States)

    Gut, Carsten; Cristea, Iulia; Neumann, Cornelius

    2016-04-01

    The following article shall describe how human vision by night can be influenced. At first, front lighting systems that are already available on the market will be described, followed by their analysis with respect to the positive effects on traffic safety. Furthermore, how traffic safety by night can be increased since the introduction of high resolution headlamps shall be discussed.

  11. High reliability organizations

    NARCIS (Netherlands)

    Gallis, R.; Zwetsloot, G.I.J.M.

    2014-01-01

    High Reliability Organizations (HRO’s) are organizations that constantly face serious and complex (safety) risks yet succeed in realising an excellent safety performance. In such situations acceptable levels of safety cannot be achieved by traditional safety management only. HRO’s manage safety

  12. High temperature interface superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gozar, A., E-mail: adrian.gozar@yale.edu [Yale University, New Haven, CT 06511 (United States); Bozovic, I. [Yale University, New Haven, CT 06511 (United States); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-02-15

    Highlight: • This review article covers the topic of high temperature interface superconductivity. • New materials and techniques used for achieving interface superconductivity are discussed. • We emphasize the role played by the differences in structure and electronic properties at the interface with respect to the bulk of the constituents. - Abstract: High-T{sub c} superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-T{sub c} Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  13. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Arthur J. Ragauskas

    2005-09-30

    The overall objective of this program was to develop improved extended oxygen delignification (EOD) technologies for current U.S. pulp mill operations. This was accomplished by: (1) Identifying pulping conditions that optimize O and OO performance; (2) Identifying structural features of lignin that enhance reactivity towards EOD of high kappa pulps; (3) Identifying factors minimizing carbohydrate degradation and improve pulp strength of EOD high kappa pulps; (4) Developing a simple, reproducible method of quantifying yield gains from EOD; and (5) Developing process conditions that significantly reduce the capital requirements of EOD while optimizing the yield benefits. Key research outcomes included, demonstrating the use of a mini-O sequence such as (E+O)Dkf:0.05(E+O) or Dkf:0.05(E+O)(E+O) without interstage washing could capture approximately 60% of the delignification efficiency of a conventional O-stage without the major capital requirements associated with an O-stage for conventional SW kraft pulps. The rate of formation and loss of fiber charge during an O-stage stage can be employed to maximize net fiber charge. Optimal fiber charge development and delignification are two independent parameters and do not parallel each other. It is possible to utilize an O-stage to enhance overall cellulosic fiber charge of low and high kappa SW kraft pulps which is beneficial for physical strength properties. The application of NIR and multi-variant analysis was developed into a rapid and simple method of determining the yield of pulp from an oxygen delignification stage that has real-world mill applications. A focus point of this program was the demonstration that Kraft pulping conditions and oxygen delignification of high and low-kappa SW and HW pulps are intimately related. Improved physical pulp properties and yield can be delivered by controlling the H-factor and active alkali charge. Low AA softwood kraft pulp with a kappa number 30 has an average improvement of 2% in

  14. High voltage pulse generator

    Science.gov (United States)

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  15. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  16. Prevention of High Blood Pressure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Prevention of High Blood Pressure Healthy lifestyle habits, proper use of medicines, and ... prevent high blood pressure or its complications. Preventing High Blood Pressure Onset Healthy lifestyle habits can help prevent high ...

  17. Effectiveness of the United States Marine Corps Tiered Evaluation System

    Science.gov (United States)

    2015-03-01

    effectiveness. 14. SUBJECT TERl’\\IS Tiered Evaluation System, First Tenn Alignment Program, Quality, Retention 15. NUMBER OF PAGES 17. SECURITY...Crider Approved by: Jeremy A. Arkes Thesis Advisor Chad W. Seagren Co-Advisor William Gates Dean, Graduate School of Business...Lastly, first- tenn Marine re-enlistees must possess a high school diploma or altemate credential (Headquatiers, United States Marine C01ps, 2010

  18. Automated feature extraction by combining polarimetric SAR and object-based image analysis for monitoring of natural resource exploitation

    OpenAIRE

    Plank, Simon; Mager, Alexander; Schöpfer, Elisabeth

    2015-01-01

    An automated feature extraction procedure based on the combination of a pixel-based unsupervised classification of polarimetric synthetic aperture radar data (PolSAR) and an object-based post-classification is presented. High resolution SpotLight dual-polarimetric (HH/VV) TerraSAR-X imagery acquired over the Doba basin, Chad, is used for method development and validation. In an iterative training procedure the best suited polarimetric speckle filter, processing parameters for the following en...

  19. Conflict, mobility and language : the case of migrant Hadjaraye of Guéra to neighboring regions of Chari-Baguirmi and Salamat (Chad)

    NARCIS (Netherlands)

    Alio, K.

    2008-01-01

    The people of Guéra known as Hadjaraye (from Arabic: the mountain dwellers) have experienced all the atrocities of war and the sufferings of drought that caused them to emigrate. In the early 1970, the ecological conditions worsened and changed for ever, giving way to cyclic droughts which resulted

  20. Raptor habitat use in the Lake Chad Basin : insights into the effect of flood-plain transformation on Afrotropical and Palearctic raptors

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.

    2013-01-01

    West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted mon

  1. The implications for dust emission modeling of spatial and vertical variations in horizontal dust flux and particle size in the Bodélé Depression, Northern Chad

    Science.gov (United States)

    Chappell, Adrian; Warren, Andrew; O'Donoghue, Alice; Robinson, Andrea; Thomas, Andrew; Bristow, Charlie

    2008-02-01

    The Bodélé Depression has been confirmed as the single largest source of atmospheric mineral dust on Earth. It is a distinctive source because of its large exposure of diatomite and the presence of mega-barchan dunes. Direct measurements of horizontal dust flux and particle size were made to investigate dust emission processes and for comparison with mechanisms of emission assumed in current dust models. More than 50 masts, with traps mounted on each, were located across and downwind of three barchans in 56 km2 study area of the eastern Bodélé. The size-distribution of surface material is bi-modal; there are many fine dust modes and a mixed mineralogy with a particle density three times smaller than quartz. Horizontal fluxes (up to 70 m above the playa) of particles, up to 1000 μm in diameter, are produced frequently from the accelerated flow over and around the barchans, even in below-threshold shear conditions on the diatomite playa. Our data on dust sizes do not conform to retrievals of dust size distributions from radiance measurements made in the same area. Dust emission models for the region may need to be revised to account for: saltators in the Bodélé, which are a mixture of quartz sand and diatomite flakes; the great spatial and vertical variation in the abundance, mass and density of dust and abraders; and the patterns of surface erodibility. All of these have important local effects on the vertical dust flux and its particle sizes.

  2. New material of Anancus kenyensis (proboscidea, mammalia) from Toros-Menalla (Late Miocene, Chad): Contribution to the systematics of African anancines

    Science.gov (United States)

    Hautier, Lionel; Mackaye, Hassane Taisso; Lihoreau, Fabrice; Tassy, Pascal; Vignaud, Patrick; Brunet, Michel

    2009-03-01

    New fossil remains of the proboscidean genus Anancus are described. Among them, a complete skull allows us to revisit for the first time the entire Chadian Anancus fossil record. This genus occurred in the Old World from the late Miocene up to the early Pleistocene. The analysis of dental and cranial characters was allowed individual variations from specific characters to be distinguished. In this study we show that Anancus kenyensis and Anancus osiris are very likely synonym taxa which leads us to emend the diagnosis of A. kenyensis. In addition, this study shows that dental characters in anancines lineage are of little significance for biostratigraphical inference, by contrast to previous works. This study brings new data about the phylogenetical and palaeobiogeographical history of the African anancines.

  3. Melt Cast High Explosives

    Directory of Open Access Journals (Sweden)

    Stanisław Cudziło

    2014-12-01

    Full Text Available [b]Abstract[/b]. This paper reviews the current state and future developments of melt-cast high explosives. First the compositions, properties and methods of preparation of trinitrotoluene based (TNT conventional mixtures with aluminum, hexogen (RDX or octogen (HMX are described. In the newer, less sensitive explosive formulations, TNT is replaced with dinitroanisole (DNANDNANDNAN and nitrotriazolone (NTONTONTO, nitroguanidine (NG or ammonium perchlorate (AP are the replacement for RDRDX and HMX. Plasticized wax or polymer-based binder systems for melt castable explosives are also included. Hydroxyl terminated polybutadiene (HPTB is the binder of choice, but polyethylene glycol, and polycaprolactone with energetic plasticizers are also used. The most advanced melt-cast explosives are compositions containing energetic thermoplastic elastomers and novel highly energetic compounds (including nitrogen rich molecules in whose particles are nanosized and practically defect-less.[b]Keywords[/b]: melt-cast explosives, detonation parameters

  4. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  5. High Speed Video Insertion

    Science.gov (United States)

    Janess, Don C.

    1984-11-01

    This paper describes a means of inserting alphanumeric characters and graphics into a high speed video signal and locking that signal to an IRIG B time code. A model V-91 IRIG processor, developed by Instrumentation Technology Systems under contract to Instrumentation Marketing Corporation has been designed to operate in conjunction with the NAC model FHS-200 High Speed Video Camera which operates at 200 fields per second. The system provides for synchronizing the vertical and horizontal drive signals such that the vertical sync precisely coincides with five millisecond transitions in the IRIG time code. Additionally, the unit allows for the insertion of an IRIG time message as well as other data and symbols.

  6. Dual Campus High School

    Directory of Open Access Journals (Sweden)

    Carmen P. Mombourquette

    2013-04-01

    Full Text Available September 2010 witnessed the opening of the first complete dual campus high school in Alberta. Catholic Central High School, which had been in existence since 1967 in one building, now offered courses to students on two campuses. The “dual campus” philosophy was adopted so as to ensure maximum program flexibility for students. The philosophy, however, was destined to affect student engagement and staff efficacy as the change in organizational structure, campus locations, and course availability was dramatic. Changing school organizational structure also had the potential of affecting student achievement. A mixed-methods study utilizing engagement surveys, efficacy scales, and interviews with students and teachers was used to ascertain the degree of impact. The results of the study showed that minimal impact occurred to levels of student engagement, minor negative impact to staff efficacy, and a slight increase to student achievement results.

  7. Desulfurization at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Panula-Nikkilae, E.; Kurkela, E.; Mojtahedi, W.

    1987-01-01

    Two high-temperature desulfurization methods, furnace injection and gasification-desulfurization are presented. In furnace injection, the efficiency of desulfurization is 50-60%, but this method is applied in energy production plants, where flue gas desulfurization cannot be used. Ca-based sorbents are used as desulfurization material. Factors affecting desulfurization and the effect of injection on the boiler and ash handling are discussed. In energy production based on gasification, very low sulfur emissions can be achieved by conventional low-temperature cleanup. However, high-temperature gas cleaning leads to higher efficiency and can be applied to smaller size classes. Ca-, Fe-, or Zn-based sorbents or mixed metals can be used for desulfurization. Most of the methods under development are based on the use of regenerative sorbents in a cleanup reactor located outside the gasifier. So far, only calcium compounds have been used for desulfurization inside the gasifier.

  8. High Temperature ESP Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jack Booker; Brindesh Dhruva

    2011-06-20

    The objective of the High Temperature ESP Monitoring project was to develop a downhole monitoring system to be used in wells with bottom hole well temperatures up to 300°C for measuring motor temperature, formation pressure, and formation temperature. These measurements are used to monitor the health of the ESP motor, to track the downhole operating conditions, and to optimize the pump operation. A 220 ºC based High Temperature ESP Monitoring system was commercially released for sale with Schlumberger ESP motors April of 2011 and a 250 ºC system with will be commercially released at the end of Q2 2011. The measurement system is now fully qualified, except for the sensor, at 300 °C.

  9. High energy beam lines

    Science.gov (United States)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  10. High integrity automotive castings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)

    2007-07-01

    This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.

  11. Ultra high resolution tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  12. High Performance Biocomputation

    Science.gov (United States)

    2005-03-01

    ab initio calculation of a small protein has been reported (1PNH, a scorpion toxin with 31 residues and 500 atoms; [3]). Hybrid classical and first...challenge can be characterized as highly computationally-savvy and fully capable of effectively exploiting state-of-the-art capability. However, there...enilarrassingly parallel comlrltations, where little or no comnmiinication is required), capacity computing is an effective approac-h. A recent extension of

  13. High Power Switching Transistor

    Science.gov (United States)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  14. High Performance RAIT

    Institute of Scientific and Technical Information of China (English)

    JamesHughes; CharlesMilligan; 等

    2001-01-01

    The ability to move 10s of TeraBytes in reasonable amounts of time are critical to many of the High Energy Physics applications.This paper examines the issues of high performance,high reliability tape storage systems,and presents the results of a 2-year ASCI Path Forward program to be able to reliably move 1GB/s to an archive that can last 20 years.This paper will cover the requirements.approach,hardware,application software,interface descriptions,performance,measured reliability and predicted reliability.This paper will also touch on future directions for this research.The current research allows systems to sustain 80MB/s of uncompressable data per Fibre Channel interface which is striped out to 8 or more drives.This looks to the application as a single tape drive from both mout and data transfer perspectives .Striping 12 RAIT systems together will provide nearly 1GB/s to tape.The reliability is provided by a method of adding parity tapes to the data stripes.For example,adding 2 parity tapes to an 8-stripe group will allow any 2 of the 10 tapes to be lost or damaged without loss of information.The reliability of RAIT with 8 stripes and 2 parities exceeds that of mirrored tapes while RAIT uses 10 tapes instead of the 16 tapes that a mirror would require.The results of this paper is to be abloe to understand the applicability of RAIT and to be able to understand when it may be useful in High Energy Physics applications.

  15. High Speed Compressor Study

    Science.gov (United States)

    2011-12-21

    are listed below, and some of these are discussed at length later. o Heat capacity issues in low temperature regenerators o Pressure drop losses...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...2003), pp 247-253. 3 Wang, X, Dai, W., et al, “Performance of a Stirling -Type Pulse Tube Cooler for High Efficiency Operation at 100Hz

  16. High Resolution Acoustical Imaging

    Science.gov (United States)

    1989-05-01

    1028 (September 1982). 26 G. Arfken , Mathematical Methods for Physicists (Academic Press, New York, 1971), 2nd printing, pp.662-666. 27 W. R. Hahn...difference in the approach used by the two methods , as noted in the previous paragraph, forming a direct mathematical com- parison may be impossible...examines high resolution methods which use a linear array to locate stationary objects which have scattered the fressure waves. Several;- new methods

  17. High resolution differential thermometer

    Directory of Open Access Journals (Sweden)

    Gotra Z. Yu.

    2009-11-01

    Full Text Available Main schematic solutions of differential thermometers with measurement resolution about 0.001°C are considered. Differential temperature primary transducer realized on a transistor differential circuit in microampere mode. Analytic calculation and schematic mathematic simulation of primary transducer are fulfilled. Signal transducer is realized on a high precision Zero-Drift Single-Supply Rail-to-Rail operation amplifier AD8552 and 24-Bit S-D microconverter ADuC834.

  18. Highly efficient sorghum transformation

    OpenAIRE

    Liu, Guoquan; Godwin, Ian D.

    2012-01-01

    A highly efficient microprojectile transformation system for sorghum (Sorghum bicolor L.) has been developed by using immature embryos (IEs) of inbred line Tx430. Co-bombardment was performed with the neomycin phosphotransferase II (nptII) gene and the green fluorescent protein (gfp) gene, both under the control of the maize ubiquitin1 (ubi1) promoter. After optimization of both tissue culture media and parameters of microprojectile transformation, 25 independent transgenic events were obtain...

  19. Highly Concurrent Scalar Processing.

    Science.gov (United States)

    1986-01-01

    rearrangement arise from data dependencies between instructions, hence it is critical that artificial - dependencies are eliminated whenever possible...An important class of artificial depen- *. dencies arise due to register reuse. In the following example, no parallelism can be • . exploited in the...specific procedure call site. The use of inteligent procedure expansion techniques is expected to be crucial to the achievement of high performance

  20. Strangeness at high temperatures

    CERN Document Server

    Schmidt, Christian

    2013-01-01

    We use up to fourth order cumulants of net strangeness fluctuations and their correlations with net baryon number fluctuations to extract information on the strange meson and baryon contribution to the low temperature hadron resonance gas, the dissolution of strange hadronic states in the crossover region of the QCD transition and the quasi-particle nature of strange quark contributions to the high temperature quark-gluon plasma phase.

  1. High Thermal Conductivity Materials

    CERN Document Server

    Shinde, Subhash L

    2006-01-01

    Thermal management has become a ‘hot’ field in recent years due to a need to obtain high performance levels in many devices used in such diverse areas as space science, mainframe and desktop computers, optoelectronics and even Formula One racing cars! Thermal solutions require not just taking care of very high thermal flux, but also ‘hot spots’, where the flux densities can exceed 200 W/cm2. High thermal conductivity materials play an important role in addressing thermal management issues. This volume provides readers a basic understanding of the thermal conduction mechanisms in these materials and discusses how the thermal conductivity may be related to their crystal structures as well as microstructures developed as a result of their processing history. The techniques for accurate measurement of these properties on large as well as small scales have been reviewed. Detailed information on the thermal conductivity of diverse materials including aluminum nitride (AlN), silicon carbide (SiC), diamond, a...

  2. High pressure ceramic joint

    Science.gov (United States)

    Ward, Michael E.; Harkins, Bruce D.

    1993-01-01

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  3. High power beam analysis

    Science.gov (United States)

    Aharon, Oren

    2014-02-01

    In various modern scientific and industrial laser applications, beam-shaping optics manipulates the laser spot size and its intensity distribution. However the designed laser spot frequently deviates from the design goal due to real life imperfections and effects, such as: input laser distortions, optical distortion, heating, overall instabilities, and non-linear effects. Lasers provide the ability to accurately deliver large amounts of energy to a target area with very high accuracy. Thus monitoring beam size power and beam location is of high importance for high quality results and repeatability. Depending on the combination of wavelength, beam size and pulse duration , laser energy is absorbed by the material surface, yielding into processes such as cutting, welding, surface treatment, brazing and many other applications. This article will cover the aspect of laser beam measurements, especially at the focal point where it matters the most. A brief introduction to the material processing interactions will be covered, followed by fundamentals of laser beam propagation, novel measurement techniques, actual measurement and brief conclusions.

  4. High energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-07-01

    This proposal is for the continuation of the High Energy Physics program at the University of California at Riverside. In hadron collider physics the authors will complete their transition from experiment UA1 at CERN to the DZERO experiment at Fermilab. On experiment UA1 their effort will concentrate on data analysis at Riverside. At Fermilab they will coordinate the high voltage system for all detector elements. They will also carry out hardware/software development for the D0 muon detector. The TPC/Two-Gamma experiment has completed its present phase of data-taking after accumulating 160 pb{sup {minus}}1 of luminosity. The UC Riverside group will continue data and physics analysis and make minor hardware improvement for the high luminosity run. The UC Riverside group is participating in design and implementation of the data acquisition system for the OPAL experiment at LEP. Mechanical and electronics construction of the OPAL hadron calorimeter strip readout system is proceeding on schedule. Data analysis and Monte Carlo detector simulation efforts are proceeding in preparation for the first physics run when IEP operation comenses in fall 1989.

  5. High redshift blazars

    CERN Document Server

    Ghisellini, G

    2013-01-01

    Blazars are sources whose jet is pointing to us. Since their jets are relativistic, the flux is greatly amplified in the direction of motion, making blazars the most powerful persistent objects in the Universe. This is true at all frequencies, but especially where their spectrum peaks. Although the spectrum of moderate powerful sources peaks in the ~GeV range, extremely powerful sources at high redshifts peak in the ~MeV band. This implies that the hard X-ray band is the optimal one to find powerful blazars beyond a redshift of ~4. First indications strongly suggest that powerful high-z blazars harbor the most massive and active early black holes, exceeding a billion solar masses. Since for each detected blazars there must exist hundreds of similar, but misaligned, sources, the search for high-z blazars is becoming competitive with the search of early massive black holes using radio-quiet quasars. Finding how the two populations of black holes (one in jetted sources, the other in radio-quiet objects) evolve i...

  6. High-voltage picoamperemeter

    Energy Technology Data Exchange (ETDEWEB)

    Bugl, Andrea; Ball, Markus; Boehmer, Michael; Doerheim, Sverre; Hoenle, Andreas; Konorov, Igor [Technische Universitaet Muenchen, Garching (Germany); Ketzer, Bernhard [Technische Universitaet Muenchen, Garching (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany)

    2014-07-01

    Current measurements in the nano- and picoampere region on high voltage are an important tool to understand charge transfer processes in micropattern gas detectors like the Gas Electron Multiplier (GEM). They are currently used to e.g. optimize the field configuration in a multi-GEM stack to be used in the ALICE TPC after the upgrade of the experiment during the 2nd long shutdown of the LHC. Devices which allow measurements down to 1pA at high voltage up to 6 kV have been developed at TU Muenchen. They are based on analog current measurements via the voltage drop over a switchable shunt. A microcontroller collects 128 digital ADC values and calculates their mean and standard deviation. This information is sent with a wireless transmitting unit to a computer and stored in a root file. A nearly unlimited number of devices can be operated simultaneously and read out by a single receiver. The results can also be displayed on a LCD directly at the device. Battery operation and the wireless readout are important to protect the user from any contact to high voltage. The principle of the device is explained, and systematic studies of their properties are shown.

  7. High Altitude Dermatology

    Science.gov (United States)

    Singh, Lt. Col. G K

    2017-01-01

    Approximately, 140 million people worldwide live permanently at high altitudes (HAs) and approximately another 40 million people travel to HA area (HAA) every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV) light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc.), cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc.) nail changes (koilonychias), airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma) are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place. PMID:28216727

  8. High altitude dermatology

    Directory of Open Access Journals (Sweden)

    G K Singh

    2017-01-01

    Full Text Available Approximately, 140 million people worldwide live permanently at high altitudes (HAs and approximately another 40 million people travel to HA area (HAA every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc., cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc. nail changes (koilonychias, airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place.

  9. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan [Mount Sinai, NY; Logvenov, Gennady [Port Jefferson Station, NY; Gozar, Adrian Mihai [Port Jefferson, NY

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  10. High speed preprocessing system

    Indian Academy of Sciences (India)

    M Sankar Kishore

    2000-10-01

    In systems employing tracking, the area of interest is recognized using a high resolution camera and is handed overto the low resolution receiver. The images seen by the low resolution receiver and by the operator through the high resolution camera are different in spatial resolution. In order to establish the correlation between these two images, the high-resolution camera image needsto be preprocessed and made similar to the low-resolution receiver image. This paper discusses the implementation of a suitable preprocessing technique, emphasis being given to develop a system both in hardware and software to reduce processing time. By applying different software/hardware techniques, the execution time has been brought down from a few seconds to a few milliseconds for a typical set of conditions. The hardware is designed around i486 processors and software is developed in PL/M. The system is tested to match the images obtained by two different sensors of the same scene. The hardware and software have been evaluated with different sets of images.

  11. High power coaxial ubitron

    Science.gov (United States)

    Balkcum, Adam J.

    In the ubitron, also known as the free electron laser, high power coherent radiation is generated from the interaction of an undulating electron beam with an electromagnetic signal and a static periodic magnetic wiggler field. These devices have experimentally produced high power spanning the microwave to x-ray regimes. Potential applications range from microwave radar to the study of solid state material properties. In this dissertation, the efficient production of high power microwaves (HPM) is investigated for a ubitron employing a coaxial circuit and wiggler. Designs for the particular applications of an advanced high gradient linear accelerator driver and a directed energy source are presented. The coaxial ubitron is inherently suited for the production of HPM. It utilizes an annular electron beam to drive the low loss, RF breakdown resistant TE01 mode of a large coaxial circuit. The device's large cross-sectional area greatly reduces RF wall heat loading and the current density loading at the cathode required to produce the moderate energy (500 keV) but high current (1-10 kA) annular electron beam. Focusing and wiggling of the beam is achieved using coaxial annular periodic permanent magnet (PPM) stacks without a solenoidal guide magnetic field. This wiggler configuration is compact, efficient and can propagate the multi-kiloampere electron beams required for many HPM applications. The coaxial PPM ubitron in a traveling wave amplifier, cavity oscillator and klystron configuration is investigated using linear theory and simulation codes. A condition for the dc electron beam stability in the coaxial wiggler is derived and verified using the 2-1/2 dimensional particle-in-cell code, MAGIC. New linear theories for the cavity start-oscillation current and gain in a klystron are derived. A self-consistent nonlinear theory for the ubitron-TWT and a new nonlinear theory for the ubitron oscillator are presented. These form the basis for simulation codes which, along

  12. High-frequency ECG

    Science.gov (United States)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    The standard ECG is by convention limited to 0.05-150 Hz, but higher frequencies are also present in the ECG signal. With high-resolution technology, it is possible to record and analyze these higher frequencies. The highest amplitudes of the high-frequency components are found within the QRS complex. In past years, the term "high frequency", "high fidelity", and "wideband electrocardiography" have been used by several investigators to refer to the process of recording ECGs with an extended bandwidth of up to 1000 Hz. Several investigators have tried to analyze HF-QRS with the hope that additional features seen in the QRS complex would provide information enhancing the diagnostic value of the ECG. The development of computerized ECG-recording devices that made it possible to record ECG signals with high resolution in both time and amplitude, as well as better possibilities to store and process the signals digitally, offered new methods for analysis. Different techniques to extract the HF-QRS have been described. Several bandwidths and filter types have been applied for the extraction as well as different signal-averaging techniques for noise reduction. There is no standard method for acquiring and quantifying HF-QRS. The physiological mechanisms underlying HF-QRS are still not fully understood. One theory is that HF-QRS are related to the conduction velocity and the fragmentation of the depolarization wave in the myocardium. In a three-dimensional model of the ventricles with a fractal conduction system it was shown that high numbers of splitting branches are associated with HF-QRS. In this experiment, it was also shown that the changes seen in HF-QRS in patients with myocardial ischemia might be due to the slowing of the conduction velocity in the region of ischemia. This mechanism has been tested by Watanabe et al by infusing sodium channel blockers into the left anterior descending artery in dogs. In their study, 60 unipolar ECGs were recorded from the entire

  13. [Detecting high risk pregnancy].

    Science.gov (United States)

    Doret, Muriel; Gaucherand, Pascal

    2009-12-20

    Antenatal care is aiming to reduce maternal land foetal mortality and morbidity. Maternal and foetal mortality can be due to different causes. Their knowledge allows identifying pregnancy (high risk pregnancy) with factors associated with an increased risk for maternal and/or foetal mortality and serious morbidity. Identification of high risk pregnancies and initiation of appropriate treatment and/or surveillance should improve maternal and/or foetal outcome. New risk factors are continuously described thanks to improvement in antenatal care and development in biology and cytopathology, increasing complexity in identifying high risk pregnancies. Level of risk can change all over the pregnancy. Ideally, it should be evaluated prior to the pregnancy and at each antenatal visit. Clinical examination is able to screen for intra-uterin growth restriction, pre-eclampsia, threatened for preterm labour; ultrasounds help in the diagnosis of foetal morphological anomalies, foetal chromosomal anomalies, placenta praevia and abnormal foetal growth; biological exams are used to screen for pre-eclampsia, gestational diabetes, trisomy 21 (for which screening method just changed), rhesus immunisation, seroconversion for toxoplasmosis or rubeola, unknown infectious disease (syphilis, hepatitis B, VIH). During pregnancy, most of the preventive strategies have to be initiated during the first trimester or even before conception. Prevention for neural-tube defects, neonatal hypocalcemia and listeriosis should be performed for all women. On the opposite, some measures are concerning only women with risk factors such as prevention for toxoplasmosis, rhesus immunization (which recently changed), tobacco complications and pre-eclampsia and intra-uterine growth factor restriction.

  14. High-fluoride groundwater.

    Science.gov (United States)

    Rao, N Subba

    2011-05-01

    Fluoride (F(-)) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F(-) in the groundwater, after understanding the chemical behavior of F(-) in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F(-)-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F(-); the concentration of TH is more than the concentration of TA at low F(-) groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F(-) groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F(-) has CH. As a result, the F(-) has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F(-) is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO(3) and a reduction of TH, and thereby a dissolution of F(-). Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F(-). Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F(-) in the groundwater.

  15. High Test Peroxide High Sealing Conical Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High Test Peroxide (HTP) Highly Compatible High Sealing Conical Seals are necessary for ground test operations and space based applications. Current conical seals...

  16. High Performance Liquid Chromatography

    Science.gov (United States)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  17. High performance steam development

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, T.; Schneider, P. [Solar Turbines Inc., San Diego, CA (United States)

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  18. High temperature superconductors

    CERN Document Server

    Paranthaman, Parans

    2010-01-01

    This essential reference provides the most comprehensive presentation of the state of the art in the field of high temperature superconductors. This growing field of research and applications is currently being supported by numerous governmental and industrial initiatives in the United States, Asia and Europe to overcome grid energy distribution issues. The technology is particularly intended for densely populated areas. It is now being commercialized for power-delivery devices, such as power transmission lines and cables, motors and generators. Applications in electric utilities include current limiters, long transmission lines and energy-storage devices that will help industries avoid dips in electric power.

  19. High speed flywheel

    Science.gov (United States)

    McGrath, Stephen V.

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.

  20. High energy cosmic rays

    CERN Document Server

    Stanev, Todor

    2010-01-01

    Offers an accessible text and reference (a cosmic-ray manual) for graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. Presents the acceleration scenario in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Compares experimental data in the atmosphere as well as underground are compared with theoretical models

  1. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  2. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  3. High Power Dye Lasers

    Science.gov (United States)

    1975-09-30

    art capabilities for developmental models of hydrogen thyratrons and solid state thyristors. Table II-l is a list of switches that have been... thyratron Table II-l Switch Ignitron GE, GL - 37207 Hydrogen Thyratron High Power Switches Peak Cur. (kA) RMS Cm. (A) 300 120 Max. Rep Rate...for 2 usec Pulse Cli„) 8 1. EG&G HY-5 2. EW. GHT9 3. EG&G Develop- mental model Thyristors 5 7.5 15 125 335 350 300 1000 300 RCA

  4. High energy electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Parkhomchuk, V. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  5. Highly Sensitive Optical Receivers

    CERN Document Server

    Schneider, Kerstin

    2006-01-01

    Highly Sensitive Optical Receivers primarily treats the circuit design of optical receivers with external photodiodes. Continuous-mode and burst-mode receivers are compared. The monograph first summarizes the basics of III/V photodetectors, transistor and noise models, bit-error rate, sensitivity and analog circuit design, thus enabling readers to understand the circuits described in the main part of the book. In order to cover the topic comprehensively, detailed descriptions of receivers for optical data communication in general and, in particular, optical burst-mode receivers in deep-sub-µm CMOS are presented. Numerous detailed and elaborate illustrations facilitate better understanding.

  6. High risk pregnancy

    Directory of Open Access Journals (Sweden)

    Bernardita Donoso Bernales

    2012-06-01

    Full Text Available It is estimated that roughly 20% of pregnancies fall into the high risk category, which in turn are responsible for over 80% of perinatal adverse outcome. Modern obstetrics has been very successful in reducing maternal morbidity and mortality. It has focused mainly on fetal and neonatal aspects, and on identifying the subgroup of pregnant women that need greater surveillance and care because of clearly identifiable risk factors. The article describes the preconceptional advice, its components and recommendations for its implementation, as well as its role in maternal and perinatal risk assessment. These interventions attempt to reduce the rates of maternal and perinatal mortality.

  7. High frequency electromagnetic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.; Ramirez, A.; Ueng, T.; Latorre, R.

    1989-09-01

    An experiment was conducted in G Tunnel at the Nevada Test Site to evaluate high frequency electromagnetic tomography as a candidate for in situ monitoring of hydrology in the near field of a heater placed in densely welded tuff. Tomographs of 200 MHz electromagnetic permittivity were made for several planes between boreholes. Data were taken before the heater was turned on, during heating and during cooldown of the rockmass. This data is interpreted to yield maps of changes in water content of the rockmass as a function of time. This interpretation is based on laboratory measurement of electromagnetic permittivity as a function of water content for densely welded tuff. 8 refs., 6 figs.

  8. High Contrast CRT.

    Science.gov (United States)

    1979-08-01

    r AD’ A076 235 WATKINS—JOHNSON Co SCOTYS VAL LEY CA F/S 9/5 N HIGH CONTRAST CRT.CU) AUG 79 6 A HOLNQUIST DAABO7—77—C—263 9 UNCLASSIFIED DEL.ET—TR—77...Air Force Systems Command A t t n : l) l . CA 2w) U I f iee ’ of \\ iva l Re ’~.ea r ch Andr ews AFI4 ( • ~~ii 4.~7 001 Washington , l ) .C. 20331

  9. ALICE High Level Trigger

    CERN Multimedia

    Alt, T

    2013-01-01

    The ALICE High Level Trigger (HLT) is a computing farm designed and build for the real-time, online processing of the raw data produced by the ALICE detectors. Events are fully reconstructed from the raw data, analyzed and compressed. The analysis summary together with the compressed data and a trigger decision is sent to the DAQ. In addition the reconstruction of the events allows for on-line monitoring of physical observables and this information is provided to the Data Quality Monitor (DQM). The HLT can process event rates of up to 2 kHz for proton-proton and 200 Hz for Pb-Pb central collisions.

  10. Clojure high performance programming

    CERN Document Server

    Kumar, Shantanu

    2013-01-01

    This is a short, practical guide that will teach you everything you need to know to start writing high performance Clojure code.This book is ideal for intermediate Clojure developers who are looking to get a good grip on how to achieve optimum performance. You should already have some experience with Clojure and it would help if you already know a little bit of Java. Knowledge of performance analysis and engineering is not required. For hands-on practice, you should have access to Clojure REPL with Leiningen.

  11. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  12. [High Pressure Gas Tanks

    Science.gov (United States)

    Quintana, Rolando

    2002-01-01

    Four high-pressure gas tanks, the basis of this study, were especially made by a private contractor and tested before being delivered to NASA Kennedy Space Center. In order to insure 100% reliability of each individual tank the staff at KSC decided to again submit the four tanks under more rigorous tests. These tests were conducted during a period from April 10 through May 8 at KSC. This application further validates the predictive safety model for accident prevention and system failure in the testing of four high-pressure gas tanks at Kennedy Space Center, called Continuous Hazard Tracking and Failure Prediction Methodology (CHTFPM). It is apparent from the variety of barriers available for a hazard control that some barriers will be more successful than others in providing protection. In order to complete the Barrier Analysis of the system, a Task Analysis and a Biomechanical Study were performed to establish the relationship between the degree of biomechanical non-conformities and the anomalies found within the system on particular joints of the body. This relationship was possible to obtain by conducting a Regression Analysis to the previously generated data. From the information derived the body segment with the lowest percentage of non-conformities was the neck flexion with 46.7%. Intense analysis of the system was conducted including Preliminary Hazard Analysis (PHA), Failure Mode and Effect Analysis (FMEA), and Barrier Analysis. These analyses resulted in the identification of occurrences of conditions, which may be becoming hazardous in the given system. These conditions, known as dendritics, may become hazards and could result in an accident, system malfunction, or unacceptable risk conditions. A total of 56 possible dendritics were identified. Work sampling was performed to observe the occurrence each dendritic. The out of control points generated from a Weighted c control chart along with a Pareto analysis indicate that the dendritics "Personnel not

  13. Saturn's rings - high resolution

    Science.gov (United States)

    1981-01-01

    Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  14. Theoretical High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Norman H.; Weinberg, Erick J.

    2014-07-14

    we provide reports from each of the six faculty supported by the Department of Energy High Energy Physics Theory grant at Columbia University. Each is followed by a bibliography of the references cited. A complete list of all of the publications in the 12/1/2010-04/30/2014 period resulting from research supported by this grant is provided in the following section. The final section lists the Ph.D. dissertations based on research supported by the grant that were submitted during this period.

  15. High-nitrogen explosives

    Energy Technology Data Exchange (ETDEWEB)

    Naud, D. (Darren); Hiskey, M. A. (Michael A.); Kramer, J. F. (John F.); Bishop, R. L. (Robert L.); Harry, H. H. (Herbert H.); Son, S. F. (Steven F.); Sullivan, G. K. (Gregg K.)

    2002-01-01

    The syntheses and characterization of various tetrazine and furazan compounds offer a different approach to explosives development. Traditional explosives - such as TNT or RDX - rely on the oxidation of the carbon and hydrogen atoms by the oxygen carrying nitro group to produce the explosive energy. High-nitrogen compounds rely instead on large positive heats of formation for that energy. Some of these high-nitrogen compounds have been shown to be less sensitive to initiation (e.g. by impact) when compared to traditional nitro-containing explosives of similar performances. Using the precursor, 3,6-bis-(3,5-dimethylpyrazol-1-yl)-s-tetrazine (BDT), several useful energetic compounds based on the s-tetrazine system have been synthesized and studied. The compound, 3,3{prime}-azobis(6-amino-s-tetrazine) or DAAT, detonates as a half inch rate stick despite having no oxygen in the molecule. Using perfluoroacetic acid, DAAT can be oxidized to give mixtures of N-oxide isomers (DAAT03.5) with an average oxygen content of about 3.5. This energetic mixture burns at extremely high rates and with low dependency on pressure. Another tetrazine compound of interest is 3,6-diguanidino-s-tetrazine(DGT) and its dinitrate and diperchlorate salts. DGT is easily synthesized by reacting BDT with guanidine in methanol. Using Caro's acid, DGT can be further oxidized to give 3,6-diguanidino-s-tetrazine-1,4-di-N-oxide (DGT-DO). Like DGT, the di-N-oxide can react with nitric acid or perchloric acid to give the dinitrate and the diperchlorate salts. The compounds, 4,4{prime}-diamino-3,3{prime}-azoxyfurazan (DAAF) and 4,4{prime}-diamino-3,3{prime}-azofurazan (DAAzF), may have important future roles in insensitive explosive applications. Neither DAAF nor DAAzF can be initiated by laboratory impact drop tests, yet both have in some aspects better explosive performances than 1,3,5-triamino-2,4,6-trinitrobenzene TATB - the standard of insensitive high explosives. The thermal stability of DAAz

  16. Shielding high energy accelerators

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    After introducing the subject of shielding high energy accelerators, point source, line-of-sight models, and in particular the Moyer model. are discussed. Their use in the shielding of proton and electron accelerators is demonstrated and their limitations noted. especially in relation to shielding in the forward direction provided by large, flat walls. The limitations of reducing problems to those using it cylindrical geometry description are stressed. Finally the use of different estimators for predicting dose is discussed. It is suggested that dose calculated from track-length estimators will generally give the most satisfactory estimate. (9 refs).

  17. High Blood Pressure Fact Sheet

    Science.gov (United States)

    ... High Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN High Blood Pressure Fact Sheet Language: English Español (Spanish) Recommend on ... time. High blood pressure is also called hypertension. High Blood Pressure in the United States Having high blood pressure ...

  18. Giant high occipital encephalocele

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2016-03-01

    Full Text Available Encephaloceles are rare embryological mesenchymal developmental anomalies resulting from inappropriate ossification in skull through with herniation of intracranial contents of the sac. Encephaloceles are classified based on location of the osseous defect and contents of sac. Convexity encephalocele with osseous defect in occipital bone is called occipital encephalocele. Giant occipital encephaloceles can be sometimes larger than the size of baby skull itself and they pose a great surgical challenge. Occipital encephaloceles (OE are further classified as high OE when defect is only in occipital bone above the foramen magnum, low OE when involving occipital bone and foramen magnum and occipito-cervical when there involvement of occipital bone, foramen magnum and posterior upper neural arches. Chiari III malformation can be associated with high or low occipital encephaloceles. Pre-operatively, it is essential to know the size of the sac, contents of the sac, relation to the adjacent structures, presence or absence of venous sinuses/vascular structures and osseous defect size. Sometimes it becomes imperative to perform both CT and MRI for the necessary information. Volume rendered CT images can depict the relation of osseous defect to foramen magnum and provide information about upper neural arches which is necessary in classifying these lesions.

  19. Highly curved microchannel plates

    Science.gov (United States)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  20. High speed multiphoton imaging

    Science.gov (United States)

    Li, Yongxiao; Brustle, Anne; Gautam, Vini; Cockburn, Ian; Gillespie, Cathy; Gaus, Katharina; Lee, Woei Ming

    2016-12-01

    Intravital multiphoton microscopy has emerged as a powerful technique to visualize cellular processes in-vivo. Real time processes revealed through live imaging provided many opportunities to capture cellular activities in living animals. The typical parameters that determine the performance of multiphoton microscopy are speed, field of view, 3D imaging and imaging depth; many of these are important to achieving data from in-vivo. Here, we provide a full exposition of the flexible polygon mirror based high speed laser scanning multiphoton imaging system, PCI-6110 card (National Instruments) and high speed analog frame grabber card (Matrox Solios eA/XA), which allows for rapid adjustments between frame rates i.e. 5 Hz to 50 Hz with 512 × 512 pixels. Furthermore, a motion correction algorithm is also used to mitigate motion artifacts. A customized control software called Pscan 1.0 is developed for the system. This is then followed by calibration of the imaging performance of the system and a series of quantitative in-vitro and in-vivo imaging in neuronal tissues and mice.

  1. High speed optical networks

    Science.gov (United States)

    Frankel, Michael Y.; Livas, Jeff

    2005-02-01

    This overview will discuss core network technology and cost trade-offs inherent in choosing between "analog" architectures with high optical transparency, and ones heavily dependent on frequent "digital" signal regeneration. The exact balance will be related to the specific technology choices in each area outlined above, as well as the network needs such as node geographic spread, physical connectivity patterns, and demand loading. Over the course of a decade, optical networks have evolved from simple single-channel SONET regenerator-based links to multi-span multi-channel optically amplified ultra-long haul systems, fueled by high demand for bandwidth at reduced cost. In general, the cost of a well-designed high capacity system is dominated by the number of optical to electrical (OE) and electrical to optical (EO) conversions required. As the reach and channel capacity of the transport systems continued to increase, it became necessary to improve the granularity of the demand connections by introducing (optical add/drop multiplexers) OADMs. Thus, if a node requires only small demand connectivity, most of the optical channels are expressed through without regeneration (OEO). The network costs are correspondingly reduced, partially balanced by the increased cost of the OADM nodes. Lately, the industry has been aggressively pursuing a natural extension of this philosophy towards all-optical "analog" core networks, with each demand touching electrical digital circuitry only at the in/egress nodes. This is expected to produce a substantial elimination of OEO costs, increase in network capacity, and a notionally simpler operation and service turn-up. At the same time, such optical "analog" network requires a large amount of complicated hardware and software for monitoring and manipulating high bit rate optical signals. New and more complex modulation formats that provide resiliency to both optical noise and nonlinear propagation effects are important for extended

  2. MANAGING HIGH-END, HIGH-VOLUME INNOVATIVE PRODUCTS

    Directory of Open Access Journals (Sweden)

    Gembong Baskoro

    2008-01-01

    Full Text Available This paper discuses the concept of managing high-end, high-volume innovative products. High-end, high-volume consumer products are products that have considerable influence to the way of life. Characteristic of High-end, high-volume consumer products are (1 short cycle time, (2 quick obsolete time, and (3 rapid price erosion. Beside the disadvantages that they are high risk for manufacturers, if manufacturers are able to understand precisely the consumer needs then they have the potential benefit or success to be the market leader. High innovation implies to high utilization of the user, therefore these products can influence indirectly to the way of people life. The objective of managing them is to achieve sustainability of the products development and innovation. This paper observes the behavior of these products in companies operated in high-end, high-volume consumer product.

  3. The use status of anticoagulation drugs for inpatients with nonvalvular atrial fibrillation in Southwest China

    Science.gov (United States)

    Zheng, Huan Jie; Ouyang, Shu Kun; Zhao, Yue; Lu, Kai; Luo, Su Xin; Xiao, Hua

    2017-01-01

    Background Oral anticoagulants (OACs) are effective for the prophylaxis of stroke in patients with atrial fibrillation (AF). This cross-sectional study aimed to investigate the status of anticoagulation treatment for hospitalized AF patients in Southwest China. Methods A total of 4760 hospitalized patients with AF were enrolled from 21 hospitals in Chongqing city from January 1 to December 31, 2013. Results Among the enrolled patients, 3785 were diagnosed with nonvalvular AF. These patients had a mean age of 74.4±10.1 years. The mean CHADS2 score of all subjects was 2.60±1.34, and 80.7% of the patients had CHADS2 ≥2. The use rate of OACs was only 11.5% for patients with a high risk for stroke (CHADS2 ≥2) and was much lower in patients from the second-level hospitals than in patients from the third-level hospitals (5.8% vs. 16.9%, P<0.001). The leading reason for the underuse of OACs in high-risk patients was physician’s nonfeasance. Conclusion This study demonstrated that the underuse of anticoagulation therapy in hospitalized patients with nonvalvular AF was particularly serious in Southwest China, especially in the second-level hospitals. Urgent and effective measures are desperately needed to improve this alarming situation in China. PMID:28293117

  4. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  5. High energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-07-01

    Hadron collider studies will focus on: (i) the search for the top quark with the newly installed D0 detector at the Fermilab Tevatron collider, (ii) the upgrade of the D0 detector to match the new main injector luminosity and (iii) R&D on silicon microstrip tracking devices for the SSC. High statistics studies of Z{sup 0} decay will continue with the OPAL detector at LEP. These studies will include a direct measurement of Z decay to neutrinos, the search for Higgs and heavy quark decays of Z. Preparations for the Large Scintillation Neutrino Detector (LSND) to measure neutrino oscillations at LAMPF will focus on data acquisition and testing of photomultiplier tubes. In the theoretical area E. Ma will concentrate on mass-generating radiative mechanisms for light quarks and leptons in renormalizable gauge field theories. J. Wudka`s program includes a detailed investigation of the magnetic-flip approach to the solar neutrino.

  6. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  7. Very high energy neutrinos

    Science.gov (United States)

    Moscoso, Luciano; Spiering, Christian

    2000-03-01

    A sky survey with neutrinos may considerably extend our understanding of cosmic phenomena. Due to the low interaction cross section of neutrinos with matter and due to the high cosmic ray background the detector must be very large (of the order of 1 km 3) and must be shielded. These new devices consist of a network of photo-tubes which are deployed in the depth of the ocean, of a lake or of the ice of South Pole. The detection of the Cherenkov light emitted by muons produced in muon neutrino interactions with the matter surrounding the detector will allow the reconstruction of the neutrino direction with an angular resolution of the order or lower than one degree. Several projects are underway. Their status will be reviewed in this paper.

  8. High Temperature Aquifer Storage

    Science.gov (United States)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  9. High energy astrophysical techniques

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents ultraviolet and X-ray astronomy, gamma-ray astronomy, cosmic ray astronomy, neutrino astronomy, and gravitational wave astronomy as distinct research areas, focusing on the astrophysics targets and the requirements with respect to instrumentation and observation methods. The purpose of the book is to bridge the gap between the reference books and the specialized literature. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities. The physical principles of photon and particle detectors are then addressed, and the specific telescopes and combinations of detectors, presented. Finally the instruments and their limits are discussed with a view to assisting readers in the planning and execution of observations. Astronomical observations with high-energy photons and particles represent the newest additions to multimessenger astronomy and this book will be of value to all with an interest in the field.

  10. High Density QCD

    CERN Document Server

    Ducati, M B G

    2001-01-01

    The dynamics of high partonic density QCD is presented considering, in the double logarithm approximation, the parton recombination mechanism built in the AGL formalism, developed including unitarity corrections for the nucleon as well for nucleus. It is shown that these corrections are under theoretical control. The resulting non linear evolution equation is solved in the asymptotic regime, and a comprehensive phenomenology concerning Deep Inelastic Scattering like $F_2$, $F_L$, $F_2^c$. $\\partial F_2/ \\partial \\ln Q^2$, $\\partial F^A_2/ \\partial \\ln Q^2$, etc, is presented. The connection of our formalism with the DGLAP and BFKL dynamics, and with other perturbative (K) and non-perturbative (MV-JKLW) approaches is analised in detail. The phenomena of saturation due to shadowing corrections and the relevance of this effect in ion physics and heavy quark production is emphasized. The implications to e-RHIC, HERA-A, and LHC physics and some open questions are mentioned.

  11. Streamflows at record highs

    Science.gov (United States)

    Streamflow was reported well above average in more than half the country during May, with flows at or near record levels for the month in 22 states, according to the U.S. Geological Survey (USGS), Department of the Interior.USGS hydrologists said that above average flow was reported at 98 of the 173 USGS key index gauging stations used in their monthly check on surface- and ground-water conditions. High flows were most prevalent in the Mississippi River basin states and in the east, with the exception of Maine, South Carolina, and Georgia. Below-average streamflow occurred in the Pacific northwest and in small scattered areas in Colorado, Kansas, Texas, and Minnesota.

  12. High Time Resolution Astrophysics

    CERN Document Server

    Phelan, Don; Shearer, Andrew

    2008-01-01

    High Time Resolution Astrophysics (HTRA) is an important new window to the universe and a vital tool in understanding a range of phenomena from diverse objects and radiative processes. This importance is demonstrated in this volume with the description of a number of topics in astrophysics, including quantum optics, cataclysmic variables, pulsars, X-ray binaries and stellar pulsations to name a few. Underlining this science foundation, technological developments in both instrumentation and detectors are described. These instruments and detectors combined cover a wide range of timescales and can measure fluxes, spectra and polarisation. These advances make it possible for HTRA to make a big contribution to our understanding of the Universe in the next decade.

  13. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  14. High Voltage Charge Pump

    KAUST Repository

    Emira, Ahmed A.

    2014-10-09

    Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.

  15. Fabrication of High T

    Science.gov (United States)

    Apperley, Miles Hyam

    1992-01-01

    Metal-clad high-T_{rm c} superconductor wires have been fabricated by conventional hot extrusion and wire drawing techniques. The fabrication processes which were used influenced the microstructure which, in turn, governed the superconducting properties of metal-clad Y-Ba-Cu-O (YBCO) and Bi-Pb-Sr-Ca-Cu-O (BPSCCO) superconductors. The ability to form these materials into long thin wires and the electrical properties of the wires were assessed. Extruded metal-clad wire was fabricated by coextruding a Cu billet containing a Ag-clad superconductor core at 920^circC and 800 ^circC for YBCO and BPSCCO materials, respectively. The deformation behaviour of the composite billets was investigated by extruding through dies with semicone angle alpha = 30 ^circ and using a range of core diameters and reduction ratios. For combinations of initial core diameter and reduction ratio, domains of deformation behaviour were established including sound flow, nonuniform flow, core fracture and sleeve fracture. Hot extruded YBCO and BPSCCO superconductor had densities estimated to be between 95% and 98% of the theoretical values. The material contained transverse cracks except for a sample of YBCO which had an addition of 10 wt% Ag. The microstructure of the YBCO material consisted of YBa _2Cu_3O{_{7-x}}, while the BPSCCO material contained an intimate mixture of the high-T _{rm c} (Bi,Pb)_2 Sr_2Ca_2Cu _3O{_ {10-x}} (110 K) and low-T _{rm c} (Bi,Pb)_2 Sr_2Ca_1Cu _2O{_ {8-x}} (80 K) phases with Ca _2CuO_3 and Sr-Ca -Cu-O impurity particles. X-ray polefigure goniometry of extruded BPSCCO superconductor revealed that the material was relatively untextured. As-extruded YBCO and BPSCCO were semiconducting. Oxygen treated YBCO had a lower normal-state resistivity than the as-extruded material, and a superconducting transition above 77 K was not achieved. Heat treatment of extruded BPSCCO regenerated superconductivity above 77 K, with the transition behaviour dependent on the proportion of high

  16. High tech cheating.

    Science.gov (United States)

    Harper, Mary G

    2006-12-01

    The use of technology has enhanced the convenience, flexibility, and efficiency of both preparatory and continuing education. Unfortunately, academic dishonesty, including plagiarism, has shown a positive correlation with the increased use of technology in education. A review of the literature related to unintended outcomes of the use of technology in nursing education and continuing education was conducted to determine the ethical implications for the nursing profession. Although nursing research dealing with academic and professional misconduct is sparse, evidence suggests that academic dishonesty is a predictor of workplace dishonesty. Given this correlation between unethical classroom behavior and unethical clinical behavior, efforts to staunch academic dishonesty may help allay professional misconduct. A combination of high tech and low tech methods may be used to minimize unethical behaviors among students and practicing professional nurses in order to maintain the integrity of the profession.

  17. Resonant High Power Combiners

    CERN Document Server

    Langlois, Michel; Peillex-Delphe, Guy

    2005-01-01

    Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.

  18. HIGH SPEED CAMERA

    Science.gov (United States)

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  19. Chromium at High Pressure

    Science.gov (United States)

    Jaramillo, Rafael

    2012-02-01

    Chromium has long served as the archetype of spin density wave magnetism. Recently, Jaramillo and collaborators have shown that Cr also serves as an archetype of magnetic quantum criticality. Using a combination of x-ray diffraction and electrical transport measurements at high pressures and cryogenic temperatures in a diamond anvil cell, they have demonstrated that the N'eel transition (TN) can be continuously suppressed to zero, with no sign of a concurrent structural transition. The order parameter undergoes a broad regime of exponential suppression, consistent with the weak coupling paradigm, before deviating from a BCS-like ground state within a narrow but accessible quantum critical regime. The quantum criticality is characterized by mean field scaling of TN and non mean field scaling of the transport coefficients, which points to a fluctuation-induced reconstruction of the critical Fermi surface. A comparison between pressure and chemical doping as means to suppress TN sheds light on different routes to the quantum critical point and the relevance of Fermi surface nesting and disorder at this quantum phase transition. The work by Jaramillo et al. is broadly relevant to the study of magnetic quantum criticality in a physically pure and theoretically tractable system that balances elements of weak and strong coupling. [4pt] [1] R. Jaramillo, Y. Feng, J. Wang & T. F. Rosenbaum. Signatures of quantum criticality in pure Cr at high pressure. Proc. Natl. Acad. Sci. USA 107, 13631 (2010). [0pt] [2] R. Jaramillo, Y. Feng, J. C. Lang, Z. Islam, G. Srajer, P. B. Littlewood, D. B. McWhan & T. F. Rosenbaum. Breakdown of the Bardeen-Cooper-Schrieffer ground state at a quantum phase transition. Nature 459, 405 (2009).

  20. Highly trifluoromethylated platinum compounds.

    Science.gov (United States)

    Martínez-Salvador, Sonia; Forniés, Juan; Martín, Antonio; Menjón, Babil

    2011-07-11

    The homoleptic, square-planar organoplatinum(II) compound [NBu(4)](2) [Pt(CF(3))(4)] (1) undergoes oxidative addition of CF(3) I under mild conditions to give rise to the octahedral organoplatinum(IV) complex [NBu(4)](2) [Pt(CF(3))(5)I] (2). This highly trifluoromethylated species reacts with Ag(+) salts of weakly coordinating anions in Me(2)CO under a wet-air stream to afford the aquo derivative [NBu(4)][Pt(CF(3))(5) (OH(2))] (4) in around 75% yield. When the reaction of 2 with the same Ag(+) salts is carried out in MeCN, the solvento compound [NBu(4) ][Pt(CF(3))(5)(NCMe)] (5) is obtained in around 80% yield. The aquo ligand in 4 as well as the MeCN ligand in 5 are labile and can be cleanly replaced by neutral and anionic ligands to furnish a series of pentakis(trifluoromethyl)platinate(IV) compounds with formulae [NBu(4)][Pt(CF(3))(5) (L)] (L=CO (6), pyridine (py; 7), tetrahydrothiophene (tht; 8)) and [NBu(4)](2) [Pt(CF(3))(5)X] (X=Cl (9), Br (10)). The unusual carbonyl-platinum(IV) derivative [NBu(4)][Pt(CF(3))(5) (CO)] (6) is thermally stable and has a ν(CO) of 2194 cm(-1). The crystal structures of 2⋅CH(2)Cl(2), 5, [PPh(4) ][Pt(CF(3))(5)(CO)] (6'), and 7 have been established by X-ray diffraction methods. Compound 2 has shown itself to be a convenient entry to the chemistry of highly trifluoromethylated platinum compounds. To the best of our knowledge, compounds 2 and 4-10 are the organoelement compounds with the highest CF(3) content to have been isolated and adequately characterized to date.

  1. FSU High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Prosper, Harrison B. [Florida State Univ., Tallahassee, FL (United States); Adams, Todd [Florida State Univ., Tallahassee, FL (United States); Askew, Andrew [Florida State Univ., Tallahassee, FL (United States); Berg, Bernd [Florida State Univ., Tallahassee, FL (United States); Blessing, Susan K. [Florida State Univ., Tallahassee, FL (United States); Okui, Takemichi [Florida State Univ., Tallahassee, FL (United States); Owens, Joseph F. [Florida State Univ., Tallahassee, FL (United States); Reina, Laura [Florida State Univ., Tallahassee, FL (United States); Wahl, Horst D. [Florida State Univ., Tallahassee, FL (United States)

    2014-12-01

    The High Energy Physics group at Florida State University (FSU), which was established in 1958, is engaged in the study of the fundamental constituents of matter and the laws by which they interact. The group comprises theoretical and experimental physicists, who sometimes collaborate on projects of mutual interest. The report highlights the main recent achievements of the group. Significant, recent, achievements of the group’s theoretical physicists include progress in making precise predictions in the theory of the Higgs boson and its associated processes, and in the theoretical understanding of mathematical quantities called parton distribution functions that are related to the structure of composite particles such as the proton. These functions are needed to compare data from particle collisions, such as the proton-proton collisions at the CERN Large Hadron Collider (LHC), with theoretical predictions. The report also describes the progress in providing analogous functions for heavy nuclei, which find application in neutrino physics. The report highlights progress in understanding quantum field theory on a lattice of points in space and time (an area of study called lattice field theory), the progress in constructing several theories of potential new physics that can be tested at the LHC, and interesting new ideas in the theory of the inflationary expansion of the very early universe. The focus of the experimental physicists is the Compact Muon Solenoid (CMS) experiment at CERN. The report, however, also includes results from the D0 experiment at Fermilab to which the group made numerous contributions over a period of many years. The experimental group is particularly interested in looking for new physics at the LHC that may provide the necessary insight to extend the standard model (SM) of particle physics. Indeed, the search for new physics is the primary task of contemporary particle physics, one motivated by the need to explain certain facts, such as the

  2. Plasma B-type Natriuretic Peptide as a Predictor of Cardiovascular Events in Subjects with Atrial Fibrillation: A Community-Based Study

    Science.gov (United States)

    Nakamura, Motoyuki; Koeda, Yorihiko; Tanaka, Fumitaka; Onoda, Toshiyuki; Itai, Kazuyoshi; Ohsawa, Masaki; Tanno, Kozo; Sakata, Kiyomi; Omama, Shinich; Ishibashi, Yasuhiro; Makita, Shinji; Ohta, Mutsuko; Ogasawara, Kuniaki; Komatsu, Takashi; Okayama, Akira

    2013-01-01

    Objectives Atrial fibrillation (AF) is a significant public health issue due to its high prevalence in the general population, and is associated with an increased risk of cardiovascular (CV) events including systemic thrombo-embolism, heart failure, and coronary artery disease. The relationship between plasma B-type natriuretic peptide (BNP) and CV risk in real world AF subjects remains unknown. Methods The subject of the study (n = 228; mean age = 69 years) was unselected individuals with AF in a community-based population (n = 15,394; AF prevalence rate = 1.5%). The CV event free rate within each BNP tertile was estimated, and Cox regression analysis was performed to examine the relative risk of the onset of CV events among the tertiles. The prognostic ability of BNP was compared to an established risk score for embolic events (CHADS2 score). In addition, to determine the usefulness of BNP as a predictor in addition to CHADS2 score, we calculated Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) indices. Results During the follow-up period 58 subjects experienced CV events (52 per 1,000 person-years). The event-free ratio was significantly lower in the highest tertile (p < 0.02). After adjustment for established CV risk factors, the hazard ratio (HR) of the highest tertile was significantly higher than that of the lowest tertile (HR = 2.38; p < 0.02). The predictive abilities of plasma BNP in terms of sensitivity and specificity for general CV events were comparable to those of CHADS2 score. Adding BNP to the CHADS2 score only model improved the NRI (0.319; p < 0.05) and the IDI (0.046; p < 0.05). Conclusion Plasma BNP is a valuable biomarker both singly or in combination with an established scoring system for assessing general CV risk including stroke, heart failure and acute coronary syndrome in real-world AF subjects. PMID:24312541

  3. Plasma B-type natriuretic peptide as a predictor of cardiovascular events in subjects with atrial fibrillation: a community-based study.

    Directory of Open Access Journals (Sweden)

    Motoyuki Nakamura

    Full Text Available OBJECTIVES: Atrial fibrillation (AF is a significant public health issue due to its high prevalence in the general population, and is associated with an increased risk of cardiovascular (CV events including systemic thrombo-embolism, heart failure, and coronary artery disease. The relationship between plasma B-type natriuretic peptide (BNP and CV risk in real world AF subjects remains unknown. METHODS: The subject of the study (n = 228; mean age = 69 years was unselected individuals with AF in a community-based population (n = 15,394; AF prevalence rate = 1.5%. The CV event free rate within each BNP tertile was estimated, and Cox regression analysis was performed to examine the relative risk of the onset of CV events among the tertiles. The prognostic ability of BNP was compared to an established risk score for embolic events (CHADS2 score. In addition, to determine the usefulness of BNP as a predictor in addition to CHADS2 score, we calculated Net Reclassification Improvement (NRI and Integrated Discrimination Improvement (IDI indices. RESULTS: During the follow-up period 58 subjects experienced CV events (52 per 1,000 person-years. The event-free ratio was significantly lower in the highest tertile (p < 0.02. After adjustment for established CV risk factors, the hazard ratio (HR of the highest tertile was significantly higher than that of the lowest tertile (HR = 2.38; p < 0.02. The predictive abilities of plasma BNP in terms of sensitivity and specificity for general CV events were comparable to those of CHADS2 score. Adding BNP to the CHADS2 score only model improved the NRI (0.319; p < 0.05 and the IDI (0.046; p < 0.05. CONCLUSION: Plasma BNP is a valuable biomarker both singly or in combination with an established scoring system for assessing general CV risk including stroke, heart failure and acute coronary syndrome in real-world AF subjects.

  4. Utilization Pattern of Antiplatelet and Anticoagulant Medicines Among the Patients Suffering From Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Sandip Jadav

    2016-07-01

    Full Text Available Background: Antithrombotic therapy is recommended in atrial fibrillation (AF patients due to high risk of stroke. However, antithrombotic therapy is often underutilized due to adverse effects and limited data available in Indian population. Aims: Primary objective was to study usage pattern of antiplatelet and anticoagulant drugs in AF patients. Secondary objective was to assess the risk of stroke and compare usage pattern of antithrombotic drugs in non-valvular atrial fibrillation (NVAF patients with application of CHADS2 and CHA2DS2-VASc score. Materials and Methods: A prospective and observational study was conducted in outpatient department for period of one year in patients > 35 years of either gender diagnosed with AF due to any established cause. CHADS2 and CHA2DS2-VASc score were used to assess risk of stroke among NVAF patients. Results: 111 patients diagnosed with AF (mean age 54 years; 54.96% female were analyzed and out of these, 78 patients were valvular AF patients and 33 were NVAF patients. Anticoagulants were predominantly prescribed in 60 valvular AF patients. Out of 33 NVAF patients, 19 (57.57% patients had CHADS2 score 1 while as per CHA2DS2-VASc score 28 (84.84% patients had score ≥ 2. Out of 33 NVAF patients, 15 (45.45% patients were prescribed warfarin, aspirin in 12 (36.36% patients and no antithrombotic therapy in 6 (18.18% patients. Conclusion: Oral anticoagulant drugs are most commonly prescribed antithrombotic drugs in valvular AF and NVAF patients for stroke prevention. CHADS2 and CHA2DS2-VASc score are easy, simple schemes to assess stroke risk in NVAF patients and helps physicians and patients to choose most suitable antithrombotic therapy.

  5. EURISOL High Power Targets

    CERN Document Server

    Kadi, Y; Lindroos, M; Ridikas, D; Stora, T; Tecchio, L; CERN. Geneva. BE Department

    2009-01-01

    Modern Nuclear Physics requires access to higher yields of rare isotopes, that relies on further development of the In-flight and Isotope Separation On-Line (ISOL) production methods. The limits of the In-Flight method will be applied via the next generation facilities FAIR in Germany, RIKEN in Japan and RIBF in the USA. The ISOL method will be explored at facilities including ISAC-TRIUMF in Canada, SPIRAL-2 in France, SPES in Italy, ISOLDE at CERN and eventually at the very ambitious multi-MW EURISOL facility. ISOL and in-flight facilities are complementary entities. While in-flight facilities excel in the production of very short lived radioisotopes independently of their chemical nature, ISOL facilities provide high Radioisotope Beam (RIB) intensities and excellent beam quality for 70 elements. Both production schemes are opening vast and rich fields of nuclear physics research. In this article we will introduce the targets planned for the EURISOL facility and highlight some of the technical and safety cha...

  6. HIGH TEMPERATURE VACUUM MIXER

    Directory of Open Access Journals (Sweden)

    E. D. Chertov

    2015-01-01

    Full Text Available The work is devoted to the creation of a new type of mixer to produce homogeneous mixtures of dissimilar materials applied to recycling of housing and communal services waste. The article describes the design of a dual-chamber device of the original high-temperature vacuum mixer, there investigated the processes occurring in the chambers of such devices. The results of theoretical and experimental research of the process of mixing recycled polyethylene with a mixture of "grinded food waste – Eco wool” are presented. The problem of the optimum choice of bending the curvilinear blades in the working volume of the seal, which is achieved by setting their profile in the form of involute arc of several circles of different radii, is examined . The dependences, allowing to define the limits of the changes of the main mode parameters the angular velocity of rotation of the working body of the mixer using two ways of setting the profile of the curvilinear blade mixer are obtained. Represented design of the mixer is proposed to use for a wide range of tasks associated with the mixing of the components with a strongly pronounced difference of physic al chemical properties and, in particular, in the production of composites out of housing and communal services waste.

  7. High-redshift cosmography

    Energy Technology Data Exchange (ETDEWEB)

    Vitagliano, Vincenzo; Xia, Jun-Qing; Liberati, Stefano [SISSA, Via Beirut 2-4, 34151 Trieste (Italy); Viel, Matteo, E-mail: vitaglia@sissa.it, E-mail: xia@sissa.it, E-mail: liberati@sissa.it, E-mail: viel@oats.inaf.it [INFN sez. Trieste, Via Valerio 2, 34127 Trieste (Italy)

    2010-03-01

    We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the dynamical equations for gravity. On the data side, we consider the most recent compilations of Supernovae and Gamma Ray Bursts catalogues. This allows to further extend the cosmographic fit up to z = 6.6, i.e. up to redshift for which one could start to resolve the low z degeneracy among competing cosmological models. In order to reliably control the cosmographic approach at high redshifts, we adopt the expansion in the improved parameter y = z/(1+z). This series has the great advantage to hold also for z > 1 and hence it is the appropriate tool for handling data including non-nearby distance indicators. We find that Gamma Ray Bursts, probing higher redshifts than Supernovae, have constraining power and do require (and statistically allow) a cosmographic expansion at higher order than Supernovae alone. Exploiting the set of data from Union and GRBs catalogues, we show (for the first time in a purely cosmographic approach parametrized by deceleration q{sub 0}, jerk j{sub 0}, snap s{sub 0}) a definitively negative deceleration parameter q{sub 0} up to the 3σ confidence level. We present also forecasts for realistic data sets that are likely to be obtained in the next few years.

  8. High-Redshift Cosmography

    CERN Document Server

    Vitagliano, Vincenzo; Liberati, Stefano; Viel, Matteo

    2009-01-01

    We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the dynamical equations for gravity. On the data side, we consider the most recent compilations of Supernovae and Gamma Ray Bursts catalogs. This allows to further extend the cosmographic fit up to $z=6.6$, i.e. up to redshift for which one could start to resolve the low $z$ degeneracy among competing cosmological models. In order to reliably control the cosmographic approach at high redshifts, we adopt the expansion in the improved parameter $y=z/(1+z)$ (as proposed in Class. Quant. Grav., 24 (2007) 5985). This series has the great advantage to hold also for $z>1$ and hence it is the appropriate tool for handling data including non-nearby distance indicators. We find that Gamma Ray Bursts, probing higher redshifts than Supernovae, have constraining power and do require (and stati...

  9. Living with High Blood Pressure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Living With High Blood Pressure If you have high blood pressure, the best thing to do is to talk ... help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother and baby. High ...

  10. High temperature materials and mechanisms

    CERN Document Server

    2014-01-01

    The use of high-temperature materials in current and future applications, including silicone materials for handling hot foods and metal alloys for developing high-speed aircraft and spacecraft systems, has generated a growing interest in high-temperature technologies. High Temperature Materials and Mechanisms explores a broad range of issues related to high-temperature materials and mechanisms that operate in harsh conditions. While some applications involve the use of materials at high temperatures, others require materials processed at high temperatures for use at room temperature. High-temperature materials must also be resistant to related causes of damage, such as oxidation and corrosion, which are accelerated with increased temperatures. This book examines high-temperature materials and mechanisms from many angles. It covers the topics of processes, materials characterization methods, and the nondestructive evaluation and health monitoring of high-temperature materials and structures. It describes the ...

  11. Early Paleozoic paleogeography of the northern Gondwana margin: new evidence for Ordovician-Silurian glaciation

    Science.gov (United States)

    Semtner, A.-K.; Klitzsch, E.

    1994-12-01

    During the Early Paleozoic, transgressions and the distribution of sedimentary facies on the northern Gondwana margin were controlled by a regional NNW-SSE to almost north-south striking structural relief. In Early Silurian times, a eustatic highstand enabled the sea to reach its maximum southward extent. The counterclockwise rotation of Gondwana during the Cambrian and Early Ordovician caused the northern Gondwana margin to shift from intertropical to southern polar latitudes in Ordovician times. Glacial and periglacial deposits are reported from many localities in Morocco, Algeria, Niger, Libya, Chad, Sudan, Jordan and Saudi Arabia. The Late Ordovician glaciation phase was followed by a period of a major glacioeustatic sea-level rise in the Early Silurian due to the retreat of the ice-cap. As a consequence of the decreasing water circulation in the basin centers (Central Arabia, Murzuk- and Ghadames basins), highly bituminous euxinic shales were deposited. These shales are considered to be the main source rock of Paleozoic oil and gas deposits in parts of Saudi Arabia, Libya and Algeria. The following regression in the southern parts of the Early Silurian sea was probably caused by a second glacial advance, which was mainly restricted to areas in Chad, Sudan and Niger. Evidence for glacial activity and fluvioglacial sedimentation is available from rocks overlying the basal Silurian shale in north-east Chad and north-west Sudan. The Early Silurian ice advance is considered to be responsible for the termination of euxinic shale deposition in the basin centers.

  12. High-intensityfocusedultrasoundtreatmentfor patientswithunresectablepancreaticcancer

    Institute of Scientific and Technical Information of China (English)

    Peng-Zhou Li; Shai-Hong Zhu; Wei He; Li-Yong Zhu; Sheng-Ping Liu; Yan Liu; Guo-Hui Wang; Fei Ye

    2012-01-01

    BACKGROUND: High-intensity focused ultrasound (HIFU) is a non-invasive method of solid tissue ablation therapy. However, only a few studies have reported the effect of HIFU for unresectable pancreatic cancer. This study aimed to evaluate the clinical beneifts, survival time and complications associated with the use of HIFU ablation in patients with unresectable pancreatic cancer. METHODS: Twenty-ifve patients with unresectable pancreatic cancer were enrolled in our study. All patients received HIFU therapy for tumors at least once. The therapeutic effects of HIFU was evaluated in terms of Karnofsky performance status (KPS) scores, pain relief, serum CA19-9, and imaging by B-US and CT before and after the therapy. We also recorded median overall survival time and complications caused by the treatment. RESULTS: In the 25 patients, KPS scores were above 60, and increased KPS was observed in 23 patients after treatment. Pain relief occurred in 23 patients. Serum CA19-9 levels were signiifcantly reduced one month after HIFU treatment and became negative in 5 patients. B-US revealed enhanced tumor echogenicity in 13 patients and decreased tumor blood supply in 9. Tumor necrosis was conifrmed by CT in 8 patients one month after HIFU treatment. The median overall survival time was 10 months, and the 1-year survival rate was 42%. No severe complications were observed after HIFU treatment. CONCLUSION: HIFU can effectively relieve pain, increase KPS, decrease tumor growth and prolong the survival time of patients with unresectable pancreatic cancer.

  13. High-efficiency CARM

    Energy Technology Data Exchange (ETDEWEB)

    Bratman, V.L.; Kol`chugin, B.D.; Samsonov, S.V.; Volkov, A.B. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)

    1995-12-31

    The Cyclotron Autoresonance Maser (CARM) is a well-known variety of FEMs. Unlike the ubitron in which electrons move in a periodical undulator field, in the CARM the particles move along helical trajectories in a uniform magnetic field. Since it is much simpler to generate strong homogeneous magnetic fields than periodical ones for a relatively low electron energy ({Brit_pounds}{le}1-3 MeV) the period of particles` trajectories in the CARM can be sufficiently smaller than in the undulator in which, moreover, the field decreases rapidly in the transverse direction. In spite of this evident advantage, the number of papers on CARM is an order less than on ubitron, which is apparently caused by the low (not more than 10 %) CARM efficiency in experiments. At the same time, ubitrons operating in two rather complicated regimes-trapping and adiabatic deceleration of particles and combined undulator and reversed guiding fields - yielded efficiencies of 34 % and 27 %, respectively. The aim of this work is to demonstrate that high efficiency can be reached even for a simplest version of the CARM. In order to reduce sensitivity to an axial velocity spread of particles, a short interaction length where electrons underwent only 4-5 cyclotron oscillations was used in this work. Like experiments, a narrow anode outlet of a field-emission electron gun cut out the {open_quotes}most rectilinear{close_quotes} near-axis part of the electron beam. Additionally, magnetic field of a small correcting coil compensated spurious electron oscillations pumped by the anode aperture. A kicker in the form of a sloping to the axis frame with current provided a control value of rotary velocity at a small additional velocity spread. A simple cavity consisting of a cylindrical waveguide section restricted by a cut-off waveguide on the cathode side and by a Bragg reflector on the collector side was used as the CARM-oscillator microwave system.

  14. High Resolution Formaldehyde Photochemistry

    Science.gov (United States)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv → HCO + H (R2) HCHO + hv → H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 → HO2 + CO (R4) H + O2 → HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure

  15. Highly Accurate Sensor for High-Purity Oxygen Determination Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this STTR effort, Los Gatos Research (LGR) and the University of Wisconsin (UW) propose to develop a highly-accurate sensor for high-purity oxygen determination....

  16. High regression rate, high density hybrid fuels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  17. Allina Health System's approach to high tech and high touch.

    Science.gov (United States)

    Tam, T A

    1997-01-01

    All health care providers, regardless of their integration status, must meet customer expectations to maintain market share and viability. The balance between high tech and high touch customer interactions is not a fad or trend. For integrated health systems with the full continuum of medical care, additional challenges are presented by the organization's competing health care delivery and financing components. Allina Health System describes its integrated health system approach to satisfying customer high tech and high touch needs.

  18. Planning High-Risk High-Reward Activities.

    NARCIS (Netherlands)

    Casault, Sébastien

    2014-01-01

    This body of work addresses a gap in financial and economic theories related to assets that are typically associated with high uncertainty. Specifically, this thesis provides some foundational work towards a new way to quantify and explain how high-risk high-reward activities, such as exploration,

  19. High Expectations, High Support: Essential Elements of Engagement. 2008 Findings

    Science.gov (United States)

    Community College Survey of Student Engagement, 2008

    2008-01-01

    This paper presents the findings of the 2008 Community College Survey of Student Engagement (CCSSE). This year, CCSSE zeroes in on high expectations and high support as it presents the results of its 2008 survey. Both are critical to student success: Students do best when expectations are high "and" they receive support that helps them…

  20. RISK OF THROMBOEMBOLIC COMPLICATIONS AND ANTITHROMBOTIC THERAPY IN IN-PATIENTS WITH PERMANENT AND RECURRENT ATRIAL FIBRILLATION IN REAL CLINICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    I. V. Grajfer

    2012-01-01

    Full Text Available Aim. Тo evaluate compliance of ongoing antithrombotic therapy (ATT in various forms of atrial fibrillation (AF with the risk level of thromboembolic complications (TEC, calculated with the СHADS2 and CHA2DS2–VASc scales in real clinical practice. Material and methods. A retrospective study of hospital records of 308 in-patients admitted to the cardiology departments of two multidisciplinary hospitals during the year because of nonvalvular AF . Risk of thromboembolic complications was estimated with the CHADS2 and CHA2DS2–VASc scales and appointed ATT was analyzed. Results. Patients with high risk of TEC were predominated in the study population: 77.6% and 91.9% according to CHADS2 and CHA2DS2–VASc scales, respectively. Moderate risk was found in  17.6%  and  6.1%  of  patients  according  to  CHADS2 and  CHA2DS2–VASc  scales,  respectively.  Only  32.2%  and  28.6%  28.6%  of  patients  at  high  risk  according  to  CHADS2 and  CHA2DS2–VASc scales, respectively received warfarin in hospital. All patients with permanent AF in this sample had a high risk of TEC according to the both scales. In the group of paroxysmal/persistent AF the high, moderate and low risk of TEC was identified in 87%, 9.9%, and 3.1% of patients, respectively , according to CHA2DS2–VASc scale and in 64.25%, 28.5% and 7.5% of patients, respectively , according to CHADS2 scale. Difference in high-risk patient rate was not significant among patients with permanent AF . In high risk group contraindications for receiving indirect anticoagulants were more frequent in the group with permanent AF (OR 3.1; 95% CI 0.88–10.7; p>0,05. The probability of warfarin prescription in patients with permanent AF was higher than in patients with paroxysmal or persistent AF (OR 1.98, 95% CI 1,18-3,31, and probability of aspirin prescription was lower (OR 0.82; 95% CI 0,51-1,32; p>0,05.  Conclusion. In real clinical practice oral anticoagulants are

  1. High Temperature Electrostrictive Ceramics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS Technologies proposes to develop high temperature electrostrictors from bismuth-based ferroelectrics. These materials will exhibit high strain and low loss in...

  2. Stroke and High Blood Pressure

    Science.gov (United States)

    ... More How High Blood Pressure Can Lead to Stroke Updated:Dec 2,2016 Stroke and high blood ... Changes That Matter • Find Tools & Resources Show Your Stroke Support! Show your stroke support with our new ...

  3. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA?s future space science missions cannot be realized without the state of the art energy storage devices which require high energy density, high reliability, and...

  4. High Performance Space Pump Project

    Data.gov (United States)

    National Aeronautics and Space Administration — PDT is proposing a High Performance Space Pump based upon an innovative design using several technologies. The design will use a two-stage impeller, high temperature...

  5. High Blood Pressure Increasing Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162977.html High Blood Pressure Increasing Worldwide And health risks may appear even ... of people around the world with elevated or high blood pressure increases, so do the number of deaths linked ...

  6. Medications for High Blood Pressure

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Medications for High Blood Pressure Share Tweet Linkedin Pin it More sharing options ... age and you cannot tell if you have high blood pressure by the way you feel, so have your ...

  7. What Causes High Blood Pressure?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Causes of High Blood Pressure Changes, either from genes or the environment, in ... and blood vessel structure and function. Biology and High Blood Pressure Researchers continue to study how various changes in ...

  8. Ear - blocked at high altitudes

    Science.gov (United States)

    High altitudes and blocked ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... eustachian tube is a connection between the middle ear (the space deep to the eardrum) and the ...

  9. High Red Blood Cell Count

    Science.gov (United States)

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  10. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Blood Pressure » Diagnosis of High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical ...

  11. High Efficency Lightweight Radiators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — XC Associates proposes to build on prior work to develop and characterize a very high efficiency, lightweight radiator constructed from high thermal conductivity...

  12. Isolating highly connected induced subgraphs

    DEFF Research Database (Denmark)

    Penev, Irena; Thomasse, Stephan; Trotignon, Nicolas

    2016-01-01

    the existence of a highly connected subgraph. We give several variants of our result, and for each of these variants, we give asymptotics for the bounds. We also compute optimal values for the case when k = 2. Alon, Kleitman, Saks, Seymour, and Thomassen proved that in a graph of high chromatic number......, there exists an induced subgraph of high connectivity and high chromatic number. We give a new proof of this theorem with a better bound....

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... page from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... are consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living ... Confirming High Blood Pressure A blood pressure test is easy and painless and can be done in ...

  15. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... page from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... are consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  16. Controlling your high blood pressure

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000101.htm Controlling your high blood pressure To use the sharing features on this page, ... JavaScript. Hypertension is another term used to describe high blood pressure. High blood pressure can lead to: Stroke Heart ...

  17. Diagnosis of High Blood Pressure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... are consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  18. What Is High Blood Pressure?

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More What is High Blood Pressure? Updated:Oct 31,2016 First, let’s define high ... resources . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  19. Advances in high temperature chemistry

    CERN Document Server

    Eyring, Leroy

    1969-01-01

    Advances in High Temperature Chemistry, Volume 2 covers the advances in the knowledge of the high temperature behavior of materials and the complex and unfamiliar characteristics of matter at high temperature. The book discusses the dissociation energies and free energy functions of gaseous monoxides; the matrix-isolation technique applied to high temperature molecules; and the main features, the techniques for the production, detection, and diagnosis, and the applications of molecular beams in high temperatures. The text also describes the chemical research in streaming thermal plasmas, as w

  20. Extremely High Current, High-Brightness Energy Recovery Linac

    CERN Document Server

    Ben-Zvi, Ilan; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Burger, Al; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Favale, Anthony; Gassner, David M; Grimes, Jacob T; Hahn, Harald; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Lambiase, Robert; Litvinenko, Vladimir N; McIntyre, Gary; Meng, Wuzheng; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Segalov, Zvi; Smith, Kevin T; Todd, Alan M M; Warren-Funk, L; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Yip, Kin; Zaltsman, Alex; Zhao, Yongxiang

    2005-01-01

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  1. Entanglement between low- and high-lying atomic spin waves

    Science.gov (United States)

    Ding, D. S.; Wang, K.; Zhang, W.; Shi, S.; Dong, M. X.; Yu, Y. C.; Zhou, Z. Y.; Shi, B. S.; Guo, G. C.

    2016-11-01

    Establishing a quantum interface between different physical systems is of special importance for developing the practical versatile quantum networks. Entanglement between low- and high-lying atomic spin waves is essential for building up Rydberg-based quantum information engineering, which is also helpful to study the dynamics behavior of entanglement under external perturbations. Here, we report on the successful storage of a single photon as a high-lying atomic spin wave in a quantum regime. By storing a K-vector entanglement between a single photon and low-lying spin wave, we experimentally realize the entanglement between low- and high-lying atomic spin waves in two separated atomic systems. This makes our experiment a primary demonstration of Rydberg quantum memory of entanglement, representing a primary step toward the construction of a hybrid quantum interface.

  2. High Cycle-life Shape Memory Polymer at High Temperature

    Science.gov (United States)

    Kong, Deyan; Xiao, Xinli

    2016-09-01

    High cycle-life is important for shape memory materials exposed to numerous cycles, and here we report shape memory polyimide that maintained both high shape fixity (Rf) and shape recovery (Rr) during the more than 1000 bending cycles tested. Its critical stress is 2.78 MPa at 250 °C, and the shape recovery process can produce stored energy of 0.218 J g-1 at the efficiency of 31.3%. Its high Rf is determined by the large difference in storage modulus at rubbery and glassy states, while the high Rr mainly originates from its permanent phase composed of strong π-π interactions and massive chain entanglements. Both difference in storage modulus and overall permanent phase were preserved during the bending deformation cycles, and thus high Rf and Rr were observed in every cycle and the high cycle-life will expand application areas of SMPs enormously.

  3. Development of a high resolution and high dispersion Thomson parabola.

    Science.gov (United States)

    Jung, D; Hörlein, R; Kiefer, D; Letzring, S; Gautier, D C; Schramm, U; Hübsch, C; Öhm, R; Albright, B J; Fernandez, J C; Habs, D; Hegelich, B M

    2011-01-01

    Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE∕E parabola for ion energies of more than 30 MeV/nucleon.

  4. Concept for a new high resolution high intensity diffractometer

    Energy Technology Data Exchange (ETDEWEB)

    Stuhr, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    A concept of a new time-of-flight powder-diffractometer for a thermal neutral beam tube at SINQ is presented. The design of the instrument optimises the contradictory conditions of high intensity and high resolution. The high intensity is achieved by using many neutron pulses simultaneously. By analysing the time-angle-pattern of the detected neutrons an assignment of the neutrons to a single pulse is possible. (author) 3 figs., tab., refs.

  5. High rate, high reliability Li/SO2 cells

    Science.gov (United States)

    Chireau, R.

    1982-03-01

    The use of the lithium/sulfur dioxide system for aerospace applications is discussed. The high rate density in the system is compared to some primary systems: mercury zinc, silver zinc, and magnesium oxide. Estimates are provided of the storage life and shelf life of typical lithium sulfur batteries. The design of lithium cells is presented and criteria are given for improving the output of cells in order to achieve high rate and high reliability.

  6. Recrystallization of High Carbon Steel during High Strain Rate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The recrystallization of high carbon steel during high temperature and high speed rolling has been studied by analyzing the stress-strain curves and the austenite grain size.Isothermal multi-pass hot compression at high strain rate was carried out by Gleeble-2000. The austenite grain size was measured by IBAS image analysis system. The results show that static recrystallization occurred at interpass time under pre-finish rolling, and at the finish rolling stage, due to the brief interpass time, static recrystallization can not be found.

  7. High power evaluation of X-band high power loads

    CERN Document Server

    Matsumoto, Shuji; Syratchev, Igor; Riddone, Germana; Wuensch, Walter

    2010-01-01

    Several types of X-band high power loads developed for several tens of MW range were designed, fabricated and used for high power tests at X-band facility of KEK. Some of them have been used for many years and few units showed possible deterioration of RF performance. Recently revised-design loads were made by CERN and the high power evaluation was performed at KEK. In this paper, the main requirements are recalled, together with the design features. The high power test results are analysed and presented

  8. Highly-efficient high-power pumps for fiber lasers

    Science.gov (United States)

    Gapontsev, V.; Moshegov, N.; Berezin, I.; Komissarov, A.; Trubenko, P.; Miftakhutdinov, D.; Berishev, I.; Chuyanov, V.; Raisky, O.; Ovtchinnikov, A.

    2017-02-01

    We report on high efficiency multimode pumps that enable ultra-high efficiency high power ECO Fiber Lasers. We discuss chip and packaged pump design and performance. Peak out-of-fiber power efficiency of ECO Fiber Laser pumps was reported to be as high as 68% and was achieved with passive cooling. For applications that do not require Fiber Lasers with ultimate power efficiency, we have developed passively cooled pumps with out-of-fiber power efficiency greater than 50%, maintained at operating current up to 22A. We report on approaches to diode chip and packaged pump design that possess such performance.

  9. High permittivity gate dielectric materials

    CERN Document Server

    2013-01-01

    "The book comprehensively covers all the current and the emerging areas of the physics and the technology of high permittivity gate dielectric materials, including, topics such as MOSFET basics and characteristics, hafnium-based gate dielectric materials, Hf-based gate dielectric processing, metal gate electrodes, flat-band and threshold voltage tuning, channel mobility, high-k gate stack degradation and reliability, lanthanide-based high-k gate stack materials, ternary hafnia and lanthania based high-k gate stack films, crystalline high-k oxides, high mobility substrates, and parameter extraction. Each chapter begins with the basics necessary for understanding the topic, followed by a comprehensive review of the literature, and ultimately graduating to the current status of the technology and our scientific understanding and the future prospects."

  10. High-Temperature Piezoelectric Sensing

    Directory of Open Access Journals (Sweden)

    Xiaoning Jiang

    2013-12-01

    Full Text Available Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.

  11. Different Demotivators for Japanese Junior High and High School Learners

    Science.gov (United States)

    Hamada, Yo

    2011-01-01

    Motivation has been studied throughout the field of language acquisition for the past 20 years. Demotivation has also been researched in Japan at primarily the university and high school level. To provide a deeper understanding of demotivation for Japanese junior and senior high school learners, this study explores the following three questions.…

  12. Early Identification of Educationally High Potential and High Risk Children.

    Science.gov (United States)

    Keogh, Barbara K.; Smith, Carol E.

    Early identification of educationally high potential and high risk children was investigated by following the same 49 children from kindergarten entrance through grade five of a regular school program. Kindergarten predictive measures were the Bender Gestalt Test and teachers' evaluations; follow-up measures were yearly standard achievement test…

  13. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    , and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. In chapter 2, a review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning...

  14. Operating mode of high pressure straws with high spatial resolution

    CERN Document Server

    Davkov, K I; Peshekhonov, V D; Cholakov, V D

    2013-01-01

    The article presents results of studying the operating mode of thin-walled drift tubes (straws) at flushing it with a high-pressure gas mixture, which allowed obtaining extremely high spatial resolution for straw detectors. The results of studying the radiation ageing of straws operating in this mode are also described.

  15. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    DEFF Research Database (Denmark)

    Varzandeh, Farhad

    to 250 °C and 2400 bar, in the deep petroleum reservoirs. Furthermore, many of these deep reservoirs are found offshore, including the North Sea and the Gulf of Mexico, making the development even more risky. On the other hand, development of these high pressure high temperature (HPHT) fields can...

  16. Pulse Radiolysis at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Christensen, H.; Sehested, Knud

    1981-01-01

    A set-up enabling pulse radiolysis measurements at high temperatures (up to 320°C) and high pressures (up to 140 bar) has been constructed in collaboration between Risö National Laboratory and Studsvik Energiteknik. The cell has been used for experiments with aqueous solutions with the purpose...

  17. Another Innovation from High Tech High--Embedded Teacher Training

    Science.gov (United States)

    Griswold, Janie; Riordan, Rob

    2016-01-01

    High Tech High School's teaching internship program blends on-the-job work with classroom theory. Interns spend two years working as full teachers as they take courses. The program serves three large purposes: Train new teachers and build capacity in the HTH organization; train teachers in and beyond HTH for success in a wide range of contexts;…

  18. High SNR Consistent Compressive Sensing

    OpenAIRE

    Kallummil, Sreejith; Kalyani, Sheetal

    2017-01-01

    High signal to noise ratio (SNR) consistency of model selection criteria in linear regression models has attracted a lot of attention recently. However, most of the existing literature on high SNR consistency deals with model order selection. Further, the limited literature available on the high SNR consistency of subset selection procedures (SSPs) is applicable to linear regression with full rank measurement matrices only. Hence, the performance of SSPs used in underdetermined linear models ...

  19. Ultra-High Temperature Gratings

    Institute of Scientific and Technical Information of China (English)

    John Canning; Somnath Bandyopadhyay; Michael Stevenson; Kevin Cook

    2008-01-01

    Regenerated gratings seeded by type-Ⅰ gratings are shown to withstand temperatures beyond 1000 ℃. The method of regeneration offers a new approach to increasing temperature resistance of stable fibre Bragg and other gratings. These ultra-high temperature (UHT) gratings extend the applicability of silicate based components to high temperature applications such as monitoring of smelters and vehicle and aircraft engines to high power fibre lasers.

  20. High-entropy alloys as high-temperature thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Shafeie, Samrand [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Guo, Sheng, E-mail: sheng.guo@chalmers.se [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Hu, Qiang [Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330029 (China); Fahlquist, Henrik [Bruker AXS Nordic AB, 17067 Solna (Sweden); Erhart, Paul [Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Palmqvist, Anders, E-mail: anders.palmqvist@chalmers.se [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden)

    2015-11-14

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.