WorldWideScience

Sample records for chad

  1. 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...

  2. CHAD USER’S GUIDE: Extracting Human Activity Information from CHAD on the PC

    Science.gov (United States)

    The Consolidated Human Activity Database (CHAD) User Guide offers a short tutorial about CHAD Access; background on the CHAD Databases; background on individual studies in CHAD; and information about using CHAD data, caveats, known problems, notes, and database design and develop...

  3. Chad; Financial Sector Stability Assessment

    OpenAIRE

    International Monetary Fund

    2011-01-01

    The financial stability of Chad is analyzed in this study. Chad's financial system is one of the least developed in the CEMAC region. Chad’s financial system is highly dependent on oil and agriculture, since it is a low-income country. In structuring the financial sector, the soundness and performance, short-term vulnerabilities, and supervision and crisis management of the Chadian banking system have been discussed with an emphasis on insurance and pension plans. In this study, the importa...

  4. A climate trend analysis of Chad

    Science.gov (United States)

    Funk, Christopher C.; Rowland, Jim; Adoum, Alkhalil; Eilerts, Gary; White, Libby

    2012-01-01

    This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), identifies significant decreases in rainfall and increases in air temperature across Chad, especially in the eastern part of the country. These analyses are based on quality-controlled station observations. Conclusions:* Summer rains have decreased in eastern Chad during the past 20 years. * Temperatures have increased by 0.8 °Celsius since 1975, amplifying the effect of droughts. * Crop yields are very low and stagnant. * The amount of farmland per person is low, and decliningrapidly.* Population growth combined with stagnating yieldscould lead to a 30 percent reduction in per capita cereal production by 2025.* In many cases, areas with changing climate are coincident with zones of substantial conflict, indicating some degree of association; however, the contribution of climate change to these conflicts is not currently understood.

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

    OpenAIRE

    Favet, Jocelyne; Lapanje, Ales; Giongo, Adriana; Kennedy, Suzanne; Aung, Yin-Yin; Cattaneo, Arlette; Austin G Davis-Richardson; Brown, Christopher T; 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...

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

    OpenAIRE

    Ahmed Fawzi Ismael; Abdel-Hady El-Gilany

    2015-01-01

    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 fur...

  7. The precipitation response to the desiccation of Lake Chad

    Energy Technology Data Exchange (ETDEWEB)

    Lauwaet D.; VanWeverberg K.; vanLipzig, N. P. M., Weverberg, K. V., Ridderb, K. D., and Goyens, C.

    2012-04-01

    Located in the semi-arid African Sahel, Lake Chad has shrunk from a surface area of 25000 km2 in 1960 to about 1350 km2 due to a series of droughts and anthropogenic influences. The disappearance of such a large open-water body can be expected to have a noticeable effect on the meteorology in the surroundings of the lake. The impact could extend even further to the west as westward propagating convective systems pass Lake Chad in the rainfall season. This study examines the sensitivity of the regional hydrology and convective processes to the desiccation of the lake using a regional atmospheric model. Three Lake Chad scenarios are applied reflecting the situation in 1960, the current situation and a potential future scenario in which the lake and the surrounding wetlands have disappeared. The model simulations span the months July-September in 2006, which includes the rainfall season in the Lake Chad area. Total precipitation amounts and the components of the hydrological cycle are found to be hardly affected by the existence of the lake. A filled Lake Chad does, however, increase the precipitation at the east side of the lake. The model results indicate that the boundary layer moisture and temperature are significantly altered downwind of the lake. By investigating a mesoscale convective system (MCS) case, this is found to affect the development and progress of the system. At first, the MCS is intensified by the more unstable boundary layer air but the persistence of the system is altered as the cold pool propagation becomes less effective. The proposed mechanism is able to explain the differences in the rainfall patterns nearby Lake Chad between the scenarios. This highlights the local sensitivity to the desiccation of Lake Chad whereas the large-scale atmospheric processes are not affected.

  8. 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.

  9. Survey of ICT and Education in Africa : Chad Country Report

    OpenAIRE

    Fall, Babacar

    2007-01-01

    This short country report, a result of larger Information for Development Program (infoDev)-supported survey of Information and Communication Technologies (ICT) in education in Africa, provides a general overview of current activities and issues related to ICT use in education in the country. Chad and its partners in development have adopted a 10-year strategy called Education and Training...

  10. 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. PMID:23876051

  11. Interview: An interview with Chad Mirkin: nanomedicine expert

    OpenAIRE

    Mirkin, Chad

    2012-01-01

    Professor Chad Mirkin received his Bachelor of Science Degree in Chemistry from Dickinson College (PA, USA) in 1986. He holds a PhD in Chemistry from Pennsylvania State University (PA, USA) and was a Postdoctoral Fellow at the Massachusetts Institute of Technology (MA, USA). He subsequently moved to Northwestern University (IL, USA) as a Professor of Chemistry in 1991. In 2004, Professor Mirkin became Director of the International Institute for Nanotechnology and holds that post currently. He...

  12. Public investment to reverse Dutch disease: the case of Chad

    OpenAIRE

    Levy, Stephanie

    2006-01-01

    "This paper studies the relevance of agricultural policies for avoiding Dutch Disease, which affects many less developed countries experiencing a resource boom. Using a computable general equilibrium model calibrated for Chad, we study the impact of using this country's annual oil revenue for public investment, particularly in the development of road and irrigation infrastructure. Our model takes into account the integration of markets and migration processes. We find that improving water acc...

  13. Is Chad Affected by Dutch or Nigerian Disease?

    OpenAIRE

    Kablan, Sandrine; Loening, Josef

    2014-01-01

    We examine the effects of the ‘natural resource curse’ on Chad and find little evidence for Dutch disease. Structural vector auto-regression suggests that changes in domestic output and prices are overwhelmingly determined by aggregate demand and supply shocks, and while oil production and high international prices negatively affect agricultural output, the effects are small. Consistent with empirical evidence for neighbouring Cameroon, we observe minimal impact on Chad’s manufacturing sector...

  14. Use of isotope hydrology in the Lake Chad basin

    International Nuclear Information System (INIS)

    This study relates to precipitations, surface waters (Chari and Logone, secondary tributaries and Lake Chad), isolated evaporation basins and underground waters in the area north-east of Lake Chad. The method is based on isotope trace measurements after evaporation. The oxygen-18 content of rain storms is generally within the range +4% to -12% vs SMOW. The weighted annual means from four stations distributed from the north to the south of the country vary from -7.84 to -5.29%- The mean contribution to the lake is estimated at approximately -5.3%. The variation in the isotopic composition of the Chari and the Logone is specified in relation to the hydrograph reading. The mean contribution of these two rivers to Lake Chad is estimated at δ18O = -3.3% vs SMOW and that of all the tributaries and the rainwaters at -3 4%.; The evaporative nature of Lake Chad is brought out by the variations in the oxygen-18 and deuterium contents of the waters. The enrichment which begins from the Chari delta is mainly a function of the relative humidity and may reach 20% oxygen-18 and 100% deuterium at the extreme end of certain river branches.; The isotopic composition of the aquifers (δ18O = -5% vs SMOW) is evidence of meteoric feeding.. Participation of the lake in the feeding of the aquifers cannot be detected beyond a limited littoral zone. Enrichment due to upward capillary movement of the aquifers in the clay beds of the Kanem evaporation basins reaches +20% oxygen-18 and +54% deuterium at the moment of salt precipitation. These salts are carried by the infiltrating rainwater which has not undergone appreciable evaporation. (author)

  15. Adaptation of the C.H.A.D. computer library to nuclear simulations

    Science.gov (United States)

    Rock, Daniel Thomas

    The Computational Hydrodynamics for Automotive Design computer program, CHAD, is a modern, three-dimensional computational fluid dynamics code that holds promise for fulfilling a need in the nuclear industry and academia. Because CHAD may be freely distributed to non export controlled countries, it offers a cheap and customizable CFD capability. Several modifications were made to CHAD to make it more usable to those in industry and academia. A first order up-winding scheme for momentum and enthalpy and a reformulated continuity equation were migrated from a historical version of CHAD developed at Argonne National Laboratory. The Portable, Extensible Toolkit for Scientific Computing, PETSc, was also added as an optional solver package for the original and reformulated continuity equations. PETSc's highly optimized parallel solvers can be activated from either CHAD's input file or the command line. Solution times for PETSc based calculations depend in large part on convergence criteria provided, however improvements in CPU time of approximately one-third have been observed. CHAD was further extended by adding a capability to monitor solution progress by specifying a coordinate in space, as well as monitoring the residuals in the problem. The ability to model incompressible fluids was also added to the code. Incompressible fluid comparisons were made using several test cases against the commercial CFD code Fluent and found to agree well. A major limitation of CHAD in the academic environment is a limited mesh generation capability. A tool for CHAD was developed that translates Gambit based neutral mesh files into a CHAD usable format. This tool was used to translate a large mesh representing a simplified cooling jacket of a BWR control rod drive. This model serves as a practical, demonstration application of a nuclear application for CHAD and PETSc. Both CHAD with PETSc and Fluent were used to obtain solutions to this problem. The overall agreement between the two

  16. Masakwa dry season cropping in the Chad Basin

    OpenAIRE

    Zach, Barbara; Kirscht, Holger; Löhr, Doris; Neumann, Katharina; Platte, Editha

    2006-01-01

    In the inundation area - the basin of the former larger Lake Chad - a special type of sorghum is grown on the clay soils (firgi). This dry-season guinea corn is also called dwarf sorghum or masakwa. In Kanuri, the dominant language in the region, sorghum is called ngawuli. The dry-season types are called ngawuli firgibe (lit. translated: sorghum of the firgi). During the dry season when the natural vegetation becomes dry and yellow, masakwa fields appear in prominent green covering large area...

  17. 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

    2013-04-01

    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

  18. 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

  19. The petroleum of the Chad: dream or nightmare for the populations

    International Nuclear Information System (INIS)

    Since 1994, the Group ESSO realized drilling in the south of the Chad and implemented the exploitation of the petroleum, with the construction of more than 300 wells and an pipeline. Even taking into account the economical interest of the petroleum exploitation, these installations cause a big modification of the life modes of the concerned inhabitants. This book aims to present the history of the fights realized by the Chad people associated to the NGO, in particular in the Petroleum Chad-Cameroon network, to defend their rights and ask for a better repartition of the new wealth. (A.L.B.)

  20. Chad: Request for a Three-Year Arrangement Under the Extended Credit Facility

    OpenAIRE

    International Monetary Fund. African Dept.

    2014-01-01

    KEY ISSUES Context: Chad is a fragile country with weak institutional capacity that needs to manage volatile and exhaustible oil revenues prudently to tackle its large development needs. Chad is enjoying a period of domestic political stability, but major regional security issues are imposing significant fiscal costs in both the short and medium term. Macroeconomic policy over the last few years has achieved a gradual tightening of the underlying fiscal policy stance together with a sizable i...

  1. Balance and dynamics of lake(s)/aquifers interactions in the hydrological basin of Lake Chad

    OpenAIRE

    Bouchez, Camille

    2015-01-01

    Lake Chad Basin (LCB) is a 2.5 billion km2 closed drainage basin, located in the center of Africa. Surface waters (rivers and lake) are unequally distributed and highly variable. The lake Chad, which shows strong surface variations, enhances the climatic variations over the LCB. The multi-layer aquifer system of the LCB is composed of two geologic units (the quaternary (Q) and the Continental Terminal (CT)) containing large water resources. They could imbalance the increasing freshwater scarc...

  2. The past history and present trends in the fisheries of Lake Chad

    OpenAIRE

    A. RAJI

    1993-01-01

    Lake Chad is a very large, shallow eutrophic lake shared by Chad, Nigeria, Niger and Cameroun. It supplies approximately 13% of Nigeria's inland fish. It however lies in an unstable ecological environment characterised by intermittent period of rainfall and drought. This creates a very large draw down area. Consequently, the fisheries are affected by the oscillation in the size of lake due to the drought. Other factors affecting the volume of water are the numerous dams on the inflow rivers. ...

  3. Chad Public Expenditure Review in the Agricultural, Rural Development, and Food Security Sector

    OpenAIRE

    World Bank

    2014-01-01

    Over the review period covered by this report (2003-2012), the budget allocated to agriculture increased noticeably more than the sector’s contribution to GDP. This reflects a notable effort by the Chad authorities to increase the budget to boost this sector’s development in recent years. In this proactive context, Chad signed its CAADP compact in December 2013 to continue supporting agric...

  4. Preliminary interpretation of environmental isotope data in the Chad Basin aquifers, NE Nigeria

    International Nuclear Information System (INIS)

    The Chad Formation is the youngest stratigraphic unit of the hydrographic Chad Basin which occupies the North Eastern part of Nigeria and stretches into neighbouring countries like Chad, Niger, Cameroun and even as far as Sudan. It is a Plio-Pleistocene mainly argillaceous sequence with three well defined arenaceous horizons referred to as Phreatic (Upper), early Plaocene (Middle) and Continental Terminal (Lower) aquifers. Most of the area of Chad Basin is Sahelian with mean annual rainfall below 500mm and characterized by high evaporation of more than 2000mm per annum and virtual absence of perennial rivers/streams except the surface water of the Lake Chad which has drastically reduced in volume due to recurrent droughts over the years. Competing demand for water in the Basin range from domestic through irrigation to industrial uses and there is increasing reliance on groundwater to meet these water requirements. Consequently, some of the aquifers of the Basin are subjected to tremendous stress and irrigation practices are characterized by heavy reliance on agrochemicals. This is against the backdrop of lack of adequate information on recharge of the aquifers and agricultural impact on groundwater resources in the basin which are crucial issues in sustainable development and environmentally sound management of the scarce water resources of the fragile ecosystem of the Chad Basin. This paper undertakes a preliminary interpretation of isotope data acquired so far under the IAEA sponsored TC Project No NIR/8/006: Isotope-based Investigations in Chad Basin Aquifers in an attempt to address some of these problems. The presence of pseudo fossil to completely fossil waters in the Middle and Lower aquifers has been inferred while Upper aquifer water shows evidence of meteoric recharge. Data assemblage is continuing and other issues like estimation of recharge (infiltration) rates, age correlation of the aquifers, water dynamics and modeling of flow regime and contaminant

  5. On the causes of the shrinking of Lake Chad

    International Nuclear Information System (INIS)

    Over the last 40 years, Lake Chad, once the sixth largest lake in the world, has decreased by more than 90% in area. In this study, we use a hydrological model coupled with a lake/wetland algorithm to simulate the effects of lake bathymetry, human water use, and decadal climate variability on the lake's level, surface area, and water storage. In addition to the effects of persistent droughts and increasing irrigation withdrawals on the shrinking, we find that the lake's unique bathymetry-which allows its division into two smaller lakes-has made it more vulnerable to water loss. Unfortunately the lake's split is favored by the 1952-2006 climatology. Failure of the lake to remerge with renewed rainfall in the 1990s following the drought years of the 1970s and 1980s is a consequence of irrigation withdrawals. Under current climate and water use, a full recovery of the lake is unlikely without an inter-basin water transfer. Breaching the barrier separating the north and south lakes would reduce the amount of supplemental water needed for recovery.

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

    OpenAIRE

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

    2008-01-01

    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°00′N, 18°53′E) was the site of discovery of Australopithecus bahrelghazali (Abel) and in the Toros-Menalla fossiliferous area, TM 266 locality (16°15′N, 17°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 biochronologic...

  7. High risk in atrial fibrillation following an ablation procedure: the wide usefulness of the CHADS(2) score.

    Science.gov (United States)

    Fauchier, Laurent; Taillandier, Sophie; Clementy, Nicolas

    2012-09-01

    Evaluation of: Chao TF, Ambrose K, Tsao HM et al. Relationship between the CHADS(2) score and risk of very late recurrences after catheter ablation of paroxysmal atrial fibrillation. Heart Rhythm 9(8), 1185-1191 (2012). Limited data are available on the predictors of adverse events and recurrences in patients with atrial fibrillation (AF) after catheter ablation. In a retrospective analysis of 238 patients with paroxysmal AF treated with catheter ablation, it was found that the congestive heart failure, hypertension, age >75 years, diabetes and previous stroke/transient ischemic attack (CHADS(2)) score was an independent predictor of AF recurrences. Moreover, among patients without recurrences at 2 years post-ablation, future recurrence rate during the subsequent follow-up was 64% in those with a CHADS(2) score of less than three, while it was only 3% in patients with a CHADS(2) score of zero. Patients with a higher CHADS(2) score have a different substrate, a more marked disease in the atrium and this may explain the higher rate of recurrence observed after AF ablation. Several more complex scores are available to separately identify the risk of different events in AF: stroke and embolic events, bleeding events, AF recurrences and progression to more sustained forms of AF. Whether it is a better strategy to use the simple CHADS(2) score to rapidly identify a global risk of all future events in AF more widely remains to be determined. PMID:23013122

  8. Groundwater vulnerability and recharge or palaeorecharge in the Southeastern Chad Basin, Chari Baguirmi aquifer

    International Nuclear Information System (INIS)

    Stable isotopes and major chemical elements have been used to investigate present or ancient groundwater renewal in the multilayered aquifer of the Chari-Baguirmi plain, South of Lake Chad. On the Western side, recharge mainly occurs from the Chari River during the flood period. Within the Ndjamena area, the rise of the piezometric level in the contaminated subsurface zone provokes an increase in nitrate concentrations. Rainfall recharge is mainly located close to the outcropping basement, i.e. on the Eastern side of the area and does not occurs in the central part of the plain where groundwater also presents a stronger evaporative signature. This supports the hypothesis attributing a major role to evaporation processes in the formation of piezometric depressions in the Sahel zone. There is no evidence of present day or ancient water recharge from Lake Chad. (author)

  9. Petrology of peraluminous and peralkaline rhyolites from the SE Lake Chad (northernmost Cameroon Line)

    Science.gov (United States)

    Mbowou, Gbambié Isaac Bertrand; Botelho, Nilson Francisquini; Lagmet, Claudial Amane; Ngounouno, Ismaïla

    2015-12-01

    Peraluminous (P.I. 1) rhyolites from SE Lake Chad consisted of quartz, alkali feldspar and oxides-hydroxides phenocrysts, display negative Eu anomaly. F-arfvedsonite, augite-hedenbergite, aegirine and aegirine-augite are present in peralkaline rhyolites. The peralkaline and peraluminous rhyolitic magmas of the SE Lake Chad derive likely from the same source, according to their coexistence on the same volcano (Hadjer Bigli); their similar Zr/Nb, Zr/Hf ratios and their linear trends established in Zr vs Nb, Zr vs Ta and Zr vs Y diagrams, which linked to removal of successive batches of magma from a mantle source or to different degrees of partial melting. These magmas generated from the partial melting model of the underplated mantle, which would have induced the intrusion of crustal materials, triggering the hydrothermal reactions. Although, the high Zr amounts are not related to bulk assimilation of partially melted crustal materials.

  10. The natural hydrous sodium silicates from the northern bank of Lake Chad : occurrence, petrology and genesis

    OpenAIRE

    Sebag, D.; Verrecchia, Eric P.; Lee, Seong-Joo; Durand, A

    2005-01-01

    Hydrous sodium silicates sometimes associated with zeolites, form in an alkaline environment, in which there is a high concentration of dissolved silica. Such an environment existed during the Holocene in N'Guigmi interdunal depressions (Lake Chad), which led to the precipitation of various types of hydrous sodium silicates, including magadiite, kenyaite, and zeolites. Scanning electron and optical microscope observations allow several microstructures to be distinguished. These microstructure...

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

    OpenAIRE

    Azétsop, Jacquineau; Ochieng, Michael

    2015-01-01

    Background 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 inc...

  12. The first australopithecine 2,500 kilometres west of the Rift Valley (Chad)

    Science.gov (United States)

    Brunet, M; Beauvilain, A; Coppens, Y; Heintz, E; Moutaye, A H; Pilbeam, D

    1995-11-16

    The first sites with Pliocene and Pleistocene mammals west of the Rift Valley in Central Africa in northern Chad were reported in 1959 (ref. 1), and documented the presence of mixed savannah and woodland habitats. Further sites and a probable Homo erectus cranio-facial fragment were subsequently discovered. In 1993 a survey of Pliocene and Pleistocene formations in the Borkou-Ennedi-Tibesti Province of Chad (B.E.T.) led to the discovery of 17 new sites in the region of Bahr el Ghazal (classical Arabic for River of the Gazelles) near Koro Toro. One site, KT 12 (15 degrees 58'10"N, 18 degrees 52'46"E) yielded an australopithecine mandible associated with a fauna biochronologically estimated to be 3.0-3.5 Myr old. Australopithecine species described since 1925 are known from southern Africa and from sites spread along the eastern Rift Valley from Tanzania to Ethiopia (Fig. 1). This new find from Chad, which is most similar in morphology to Australopithecus afarensis, documents the presence of an early hominid a considerable distance, 2,500 km, west of the Rift Valley. PMID:7477344

  13. A field-based investigation of hydrogeologic impacts on the Lake Chad basin

    Science.gov (United States)

    Lee, J.; Goni, I. B.; Grindley, J.; Bura, B.; Mulugeta, V.; Banks, M. L.; Ndunguru, G. G.; Adisa, S. J.; Adegoke, J. O.

    2009-12-01

    Lake Chad was once one of the largest freshwater lakes in the world but has been shrinking dramatically in the last three decades due to poor water resources management and global climate change. The Lake Chad basin has various scientific issues including extending wetlands with invasive species, shortage of water resources, flooding and drought, geomorphologic alteration from desertification, and chemical and biological transition of soil and vegetation. During the summer of 2009, US-Nigeria research team consisting of five professors and eight students from three universities implemented extensive field research along the Hadejia, Jama'are and Komadugu river systems in the Kumadugu-Yobe basin. This basin is a part of Lake Chad basin located in the Sudano-Sahelian zone of northeastern Nigeria. The downstream of the river system discharges water into the lake. Among many issues mentioned above, we focused on groundwater and surface water interactions, recharge potential of soil cover, water quality, and ground temperature. We collected more than a hundred water samples and over seventy soil samples from upstream of the Hadejia-Jama’are river to downstream terminating at the lake. The preliminary analysis shows that the effluent stream pattern at upstream near the Kano river changes at the midstream of Hadejia-Jama’are wetland where the boundary between the impermeable granite basement rock and the permeable Chad formation exists. As the groundwater in the upstream is mostly stored in the fractured aquifer in the basement rock, water table is relatively shallow compared to the one in the mid- and downstream of the river system where Chad formation is dominant. It is observed that the stage of surface water at Hadejia-Jama’are wetland is higher than groundwater and even surrounding ground elevation. This observation may support the expansion of wetland and frequent flooding events during wet season around the midstream area. The amount of discharge at

  14. Detection of groundwater from space-based IR data: application to the Lake Chad basin.

    Science.gov (United States)

    Lopez, Teodolina; Antoine, Raphaël; Rabinowicz, Michel; Darrozes, José; Kerr, Yann; Cazenave, Anny

    2015-04-01

    In Lake Chad basin, the Quaternary phreatic Aquifer (named hereafter QPA) presents large piezometric anomalies referred as domes and depressions. The depth of these piezometric anomalies are ~15 m and ~60 m, respectively [1]. Three others aquifers have been described in the Lake Chad basin and they are separated from the QPA by a thick layer of Pliocene clay. Leblanc et al. (2003) discovered that brightness temperatures from METEOSAT infrared images of the Lake Chad basin show a correlation with the QPA piezometry. Indeed, during wet seasons, domes are associated with warm brightness temperatures, at the contrary of the depressions, which appear cold in METEOSAT images. Through this observation, these authors [2] proposed that this thermal behaviour results from an excess of evapotranspiration that can also explain the formation of the piezometric anomalies. However, data provided by temperature logs in oil wells QPA measurements lead us to propose another hypothesis. Temperature logs obtained in oil wells [3] illustrate that in the ancient Lake Chad and in the Bornu depression, at the SW of the Lake, heat transport is made by convection in the ~3 km deep confined aquifers. Moreover, we have estimated that the heat fluxes at the surface of the ancient Lake Chad can reach 138 mW m-2 and in the Bornu depression, ~63 mW m-2. Others oil wells show that, at the exterior of the depression, the heat transport is conductive and the heat fluxes at the surface are ~50 mW m-2. These new observations and our convective model permit us to propose that beneath the depressions, a cold descending convective current suck the QPA. Beneath the dome, a warm ascending current creates an overpressure in the QPA. Now, to explain the link observed with the thermal behaviour, we propose that over the domes, as the QPA is warm, heat is transported by capillarity. The piezometric depressions regions are associated with a presence of clay-rich soils at the surface, which makes difficult the

  15. 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

  16. 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.

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

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    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.

  18. Treating cattle to protect people? Impact of footbath insecticide treatment on tsetse density in Chad.

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    Noël Ndeledje

    Full Text Available BACKGROUND: In Chad, several species of tsetse flies (Genus: Glossina transmit African animal trypanosomoses (AAT, which represents a major obstacle to cattle rearing, and sleeping sickness, which impacts public health. After the failure of past interventions to eradicate tsetse, the government of Chad is now looking for other approaches that integrate cost-effective intervention techniques, which can be applied by the stake holders to control tsetse-transmitted trypanosomoses in a sustainable manner. The present study thus attempted to assess the efficacy of restricted application of insecticides to cattle leg extremities using footbaths for controlling Glossina m. submorsitans, G. tachinoides and G. f. fuscipes in southern Chad. METHODOLOGY/PRINCIPAL FINDINGS: Two sites were included, one close to the historical human African trypanosomiasis (HAT focus of Moundou and the other to the active foci of Bodo and Moissala. At both sites, a treated and an untreated herd were compared. In the treatment sites, cattle were treated on a regular basis using a formulation of deltamethrin 0.005% (67 to 98 cattle were treated in one of the sites and 88 to 102 in the other one. For each herd, tsetse densities were monthly monitored using 7 biconical traps set along the river and beside the cattle pen from February to December 2009. The impact of footbath treatment on tsetse populations was strong (p < 10(-3 with a reduction of 80% in total tsetse catches by the end of the 6-month footbath treatment. CONCLUSIONS/SIGNIFICANCE: The impact of footbath treatment as a vector control tool within an integrated strategy to manage AAT and HAT is discussed in the framework of the "One Health" concept. Like other techniques based on the treatment of cattle, this technology should be used under controlled conditions, in order to avoid the development of insecticide and acaricide resistance in tsetse and tick populations, respectively.

  19. An appraisal of the efficiency of fish marketing system in Lake Chad basin

    OpenAIRE

    Bolorunduro, P.; Sule, O.D.

    2003-01-01

    Fish products from the Chad Basin Lake play important role in meeting fish protein needs of Nigeria: they contribute not less than 25% of the total domestic fish supply and are significant in determining the availability of processed products and reduction of post-harvest losses. Processors, marketers and consumers are the major actors in appraising a marketing system. The results show that most sellers (4-7.5%) are within the age range of 30-39 years. Desires for more earnings led the market...

  20. Petroleum and natural gas economy in Arab countries and in Iran, Angola, Gabon, Nigeria and Chad

    International Nuclear Information System (INIS)

    This paper describes briefly main informations on petroleum prices and market trends, trade and contracts, petroleum exploration in Algeria, Chad, Gabon, Libya, Saudi Arabia and Tunisia, new crude oil discoveries in Nigeria. In Iran, a joint venture will be constituted with Gaz de France for natural gas export in Europe. In Egypt, National Bank has financed for the first time a Liquefied Petroleum Gas plant. Statistics on petroleum and natural gas reserves, production, seismic surveys, drilling operations and refining units are also given. 9 tabs

  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. Evolution of Lake Chad Basin hydrology during the mid-Holocene: A preliminary approach from lake to climate modelling

    Science.gov (United States)

    Sepulchre, Pierre; Schuster, Mathieu; Ramstein, Gilles; Krinnezr, Gerhard; Girard, Jean-Francois; Vignaud, Patrick; Brunet, Michel

    2008-03-01

    During the mid-Holocene (6000 yr Before Present, hereafter yr BP) the Chad Basin was occupied by a large endoreic lake, called Lake Mega-Chad. The existence of this lake at that time seems linked to increased monsoonal moisture supply to the Sahel and the Sahara, which in turn was probably ultimately caused by variations in the orbital forcing and higher temperature gradients between ocean and continent. This study provides a synthesis of several works carried out on the Lake Chad Basin and analyses the results of a simulation of the mid-Holocene climate with an Atmosphere General Circulation Model (LMDZ for Laboratoire de Météorologie Dynamique, IPSL Paris), with emphasis on the possible conditions leading to the existence of Lake Mega-Chad. The aim is to define the best diagnostics to understand which mechanisms lead to the existence of the large lake. This paper is the first step of an ongoing work that intends to understand the environmental conditions that this part of Africa experienced during the Upper Miocene (ca. 7 Ma BP), an epoch that was contemporaneous with the first known hominids. Indeed, early hominids of Lake Chad Basin, Australopithecus bahrelghazali [ Brunet, M., et al., 1995. The first australopithecine 2500 kilometers west of the Rift-Valley (Chad). Nature, 378(6554): 273-275] and Sahelanthropus tchadensis [Brunet, M., et al., 2002. A new hominid from the Upper Miocene of Chad, central Africa. Nature, 418(6894): 145-151; Brunet, M., et al., 2005. New material of the earliest hominid from the Upper Miocene of Chad. Nature, 434(7034): 752-755] are systematically associated with wet episodes that are documented for 7 Ma BP [Vignaud, P., et al., 2002. Geology and palaeontology of the Upper Miocene Toros-Menalla hominid locality, Chad. Nature, 418(6894): 152-155] and testified by extended lacustrine deposits (diatomites, pelites, various aquatic fauna). Because the mid-Holocene was the last such mega-lake episode, our aim here is to assess the

  3. [Newcastle disease in southern Chad: peak epidemic periods and the impact of vaccination].

    Science.gov (United States)

    Maho, A; Ndeledje Gondje, N; Mopate, L Y; Ganda Kana, S

    2004-12-01

    In spite of its universally acknowledged importance, backyard chicken production is still being hampered by Newcastle disease in some parts of the world. In Chad, the disease has been reported almost everywhere in the country and confirmed in several regions, but there are no control measures in place. A survey was conducted at three sites in south-eastern Chad in July and August 2001, based on face-to-face interviews with 20% of the peasant farmers keeping chickens at these sites. The aim was to collect information on peak epidemic periods and on ways in which the infection spreads. The survey revealed that the peak epidemic periods for Newcastle disease are April, during the mango harvesting and selling period, and December, when trade increases for the seasonal festivities. The survey also showed that peasant farmers attach great importance to chicken farming. The survey was followed by a vaccination trial in November 2001 and February 2002, using the La Sota strain administered ocularly. All of the birds vaccinated during the trial were successfully protected from the disease and both chicken production and the income of the villagers increased. The authors conclude that in order to sustain poultry farming and maximise production in the southern zone, vaccination programmes must be urgently introduced, campaigns to raise awareness of Newcastle disease should be carried out and financial support to pay for vaccines should be provided. Efforts to combat other causes of poultry mortality must also be undertaken. PMID:15861872

  4. A fossil aardvark (Mammalia, Tubulidentata) from the lower Pliocene of Chad

    Science.gov (United States)

    Lehmann, Thomas; Vignaud, Patrick; Mackaye, Hassane Taïsso; Brunet, Michel

    2004-12-01

    The Mission Paléoanthropologique Franco-Tchadienne (MPFT) found a new species of Orycteropodidae (Mammalia, Tubulidentata) in the Kollé fossiliferous sector, northern Chad. After Orycteropus abundulafus [Journal of Vertebrate Paleontology 20 (1) (2000) 205-209; Lehmann, T., Vignaud, P., Likius A., Brunet M., in press. A new Orycteropodidae (Mammalia, Tubulidentata) in the Mio-Pliocene of Northern Chad. Zool. J. Linnean Soc.], this specimen is the second complete skeleton of fossil aardvark found in the Djurab desert. It is the first complete representative of an Orycteropus species found in the Pliocene of Africa. In regard to the Miocene fossil aardvarks, this new taxon, Orycteropus djourabensis nov. sp., shows more affinities with the extant O. afer. The main differences are the larger teeth and the shorter hand in the fossil form. Kossom Bougoudi and Kollé represent a chronological series that gives a unique opportunity for studying the evolution of the African Tubulidentata around the Mio-Pliocene boundary (5.5-4 My). The new species is distinct from the older Chadian Orycteropodid from KB and it embodies the taxonomic turnover that took place within the order Tubulidentata around this boundary in Africa. Moreover, this new species is the oldest known Orycteropus species that clearly belongs to the modern forms including the extant aardvark.

  5. 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

    2008-03-01

    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. PMID:18305174

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

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    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

  7. 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. PMID:27009217

  8. [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. PMID:24736219

  9. 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.

  10. Subsurface Hydrology of the Lake Chad Basin from Convection Modelling and Observations

    Science.gov (United States)

    Lopez, T.; Antoine, R.; Kerr, Y.; Darrozes, J.; Rabinowicz, M.; Ramillien, G.; Cazenave, A.; Genthon, P.

    2016-03-01

    In the Lake Chad basin, the quaternary phreatic aquifer (named hereafter QPA) presents large piezometric anomalies referred to as domes and depressions whose depths are ~15 and ~60 m, respectively. A previous study (Leblanc et al. in Geophys Res Lett, 2003, doi: 10.1029/2003GL018094) noticed that brightness temperatures from METEOSAT infrared images of the Lake Chad basin are correlated with the QPA piezometry. Indeed, at the same latitude, domes are ~4-5 K warmer than the depressions. Leblanc et al. (Geophys Res Lett, 2003, doi: 10.1029/2003GL018094) suggested that such a thermal behaviour results from an evapotranspiration excess above the piezometric depressions, an interpretation implicitly assuming that the QPA is separated from the other aquifers by the clay-rich Pliocene formation. Based on satellite visible images, here we find evidence of giant polygons, an observation that suggests instead a local vertical connectivity between the different aquifers. We developed a numerical water convective model giving an alternative explanation for the development of QPA depressions and domes. Beneath the depressions, a cold descending water convective current sucks down the overlying QPA, while, beneath the dome, a warm ascending current produces overpressure. Such a basin-wide circulation is consistent with the water geochemistry. We further propose that the thermal diurnal and evaporation/condensation cycles specific to the water ascending current explain why domes are warmer. We finally discuss the possible influence of the inferred convective circulation on the transient variations of the QPA reported from observations of piezometric levels and GRACE-based water mass change over the region.

  11. 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.

  12. Can the woodfuel supply in sub-Saharan Africa be sustainable? The case of N'Djamena, Chad

    International Nuclear Information System (INIS)

    Chad, like many other sub-Saharan African countries, depends for most of its energy demand on woodfuels; 90% or more of the country's energy balance comes from biomass energy. Obvious environmental problems appear around cities because of their highly concentrated demand, and this threatens the sustainability of supply. But, this does not need to be a problem, and woodfuel can also be an engine of economic growth, particularly in rural areas. A few policy conditions will need to be satisfied and in Chad this appears to be the case. As a result, the woodfuel supply of the capital N'Djamena could become sustainable, thereby continuing to provide low-cost energy to the urban population for the foreseeable future while giving income generation opportunities in rural areas. A win-win situation?!

  13. Hb Chad or alpha 223(B4)Glu----Lys beta 2 observed in members of a Surinam family in association with alpha-thalassemia-2 and with Hb S.

    Science.gov (United States)

    Codrington, J F; Codrington, F A; Wisse, J H; Wilson, J B; Webber, B B; Wong, S C; Huisman, T H

    1989-01-01

    Three different hemoglobinopathies, i.e. Hb S, Hb Chad [alpha 23 (B4)Glu----Lys], and alpha-thalassemia-2 (-3.7) have been observed in eight members of a family from Surinam. The proposita had all three abnormalities, while her mother and four of her half-brothers had Hb Chad together with an alpha-thalassemia-2 heterozygosity or homozygosity. Gene mapping and dot-blot analysis of amplified DNA identified a G----A mutation in codon 23 of the alpha 2 alpha 1 hybrid gene resulting in the Glu----Lys substitution. The quantity of the alpha-Chad chain averaged 31.5% in its carriers with an additional alpha-thalassemia-2 heterozygosity [-alpha Chad(-3.7 kb)/alpha alpha], and 43% in the two carriers with an additional alpha-thalassemia-2 homozygosity [-alpha Chad (-3.7 kb)/-alpha (3.7 kb)]. These quantities are considerably higher than those reported for families from Chad, China, and Japan; the low levels of 14.5-24% Hb Chad in members of previously reported cases suggest a mutation on a chromosome with two alpha-globin genes [alpha alpha Chad/alpha alpha or alpha Chad alpha/alpha alpha]. PMID:2606723

  14. Compromize and Controversy Over Global Intercountry Adoption: A Comparative Analysis of Adoption in Haiti, Chad, Southeast Asian Countries, and Cambodia

    OpenAIRE

    Uchehara, Kieran E.

    2011-01-01

    Abstract Authorities in belligerent countries are now faced with a new problem:  modern warfare and natural disasters. Between 2001 and 2010, four relatively publicized adoption related cases have caused some Third World countries to revitalize their concerns over the rights of children in such cases of adoption, mainly the New Life Children's Refuge (NLCR) in Haiti, the Zoe's Ark in Chad, the Katherine Hart case in Southeast Asian countries, and the twelve United States adoptive parents' c...

  15. Studies on the biology of Gymnarchus niloticus in Lake Chad: Age determination and growth; meristic and morphometric characters

    OpenAIRE

    Sagua, V.O.

    1985-01-01

    The meristic and morphometric characteristics of Gymnarchus niloticus are described and linear equations relating various parts of the body to the head length or total length are given. The age of G. niloticus in Lake Chad (Nigeria) was determined from growth marks on the opercular bones. The mean lengths for age, and mean weights for age obtained for the first five years of life are given. The assymptotic length and the von Betarlanffy growth parameters for the males and females combined are...

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

    OpenAIRE

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

    2015-01-01

    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 prese...

  17. 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.

  18. Advanced Land Use Classification for Nigeriasat-1 Image of Lake Chad Basin

    Science.gov (United States)

    Babamaaji, R.; Park, C.; Lee, J.

    2009-12-01

    Lake Chad is a shrinking freshwater lake that has been significantly reduced to about 1/20 of its original size in the 1960’s. The severe draughts in 1970’s and 1980’s and following overexploitations of water resulted in the shortage of surface water in the lake and the surrounding rivers. Ground water resources are in scarcity too as ground water recharge is mostly made by soil infiltration through soil and land cover, but this surface cover is now experiencing siltation and expansion of wetland with invasive species. Large changes in land use and water management practices have taken place in the last 50 years including: removal of water from river systems for irrigation and consumption, degradation of forage land by overgrazing, deforestation, replacing natural ecosystems with mono-cultures, and construction of dams. Therefore, understanding the change of land use and its characteristics must be a first step to find how such changes disturb the water cycle around the lake and affect the shrinkage of the lake. Before any useful thematic information can be extracted from remote sensing data, a land cover classification system has to be developed to obtain the classes of interest. A combination of classification systems used by Global land cover, Water Resources eAtlass and Lake Chad Basin Commission gave rise to 7 land cover classes comprising of - Cropland, vegetation, grassland, water body, shrub-land, farmland ( mostly irrigated) and bareland (i.e. clear land). Supervised Maximum likelihood classification method was used with 15 reference points per class chosen. At the end of the classification, the overall accuracy is 93.33%. Producer’s accuracy for vegetation is 40% compare to the user’s accuracy that is 66.67 %. The reason is that the vegetation is similar to shrub land, it is very hard to differentiate between the vegetation and other plants, and therefore, most of the vegetation is classified as shrub land. Most of the waterbodies are occupied

  19. Unacceptably high mortality related to measles epidemics in Niger, Nigeria, and Chad.

    Directory of Open Access Journals (Sweden)

    R F Grais

    2007-01-01

    Full Text Available BACKGROUND: Despite the comprehensive World Health Organization (WHO/United Nations Children's Fund (UNICEF measles mortality-reduction strategy and the Measles Initiative, a partnership of international organizations supporting measles mortality reduction in Africa, certain high-burden countries continue to face recurrent epidemics. To our knowledge, few recent studies have documented measles mortality in sub-Saharan Africa. The objective of our study was to investigate measles mortality in three recent epidemics in Niamey (Niger, N'Djamena (Chad, and Adamawa State (Nigeria. METHODS AND FINDINGS: We conducted three exhaustive household retrospective mortality surveys in one neighbourhood of each of the three affected areas: Boukoki, Niamey, Niger (April 2004, n = 26,795; Moursal, N'Djamena, Chad (June 2005, n = 21,812; and Dong District, Adamawa State, Nigeria (April 2005, n = 16,249, where n is the total surveyed population in each of the respective areas. Study populations included all persons resident for at least 2 wk prior to the study, a duration encompassing the measles incubation period. Heads of households provided information on measles cases, clinical outcomes up to 30 d after rash onset, and health-seeking behaviour during the epidemic. Measles cases and deaths were ascertained using standard WHO surveillance-case definitions. Our main outcome measures were measles attack rates (ARs and case fatality ratios (CFRs by age group, and descriptions of measles complications and health-seeking behaviour. Measles ARs were the highest in children under 5 y old (under 5 y: 17.1% in Boukoki, 17.2% in Moursal, and 24.3% in Dong District. CFRs in under 5-y-olds were 4.6%, 4.0%, and 10.8% in Boukoki, Moursal, and Dong District, respectively. In all sites, more than half of measles cases in children aged under 5 y experienced acute respiratory infection and/or diarrhoea in the 30 d following rash onset. Of measles cases, it was reported that 85

  20. 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)). PMID:27010208

  1. Factors determining water treatment behavior for the prevention of cholera in Chad.

    Science.gov (United States)

    Lilje, Jonathan; Kessely, Hamit; Mosler, Hans-Joachim

    2015-07-01

    Cholera is a well-known and feared disease in developing countries, and is linked to high rates of morbidity and mortality. Contaminated drinking water and the lack of sufficient treatment are two of the key causes of high transmission rates. This article presents a representative health survey performed in Chad to inform future intervention strategies in the prevention and control of cholera. To identify critical psychological factors for behavior change, structured household interviews were administered to N = 1,017 primary caregivers, assessing their thoughts and attitudes toward household water treatment according to the Risk, Attitude, Norm, Ability, and Self-regulation model. The intervention potential for each factor was estimated by analyzing differences in means between groups of current performers and nonperformers of water treatment. Personal risk evaluation for diarrheal diseases and particularly for cholera was very low among the study population. Likewise, the perception of social norms was found to be rather unfavorable for water treatment behaviors. In addition, self-reported ability estimates (self-efficacy) revealed some potential for intervention. A mass radio campaign is proposed, using information and normative behavior change techniques, in combination with community meetings focused on targeting abilities and personal commitment to water treatment. PMID:25918206

  2. Malnutrition and Mortality Patterns among Internally Displaced and Non-Displaced Population Living in a Camp, a Village or a Town in Eastern Chad

    OpenAIRE

    Gilles Guerrier; Malaïka Zounoun; Olimpia Delarosa; Isabelle Defourny; Michelo Lacharite; Vincent Brown; Biagio Pedalino

    2009-01-01

    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 ho...

  3. 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

  4. The cow emerges from the water : myths relating to the origin of cattle in the Chad basin

    OpenAIRE

    Braukämper, U.

    1997-01-01

    The region of Lake Chad is one of the earliest and most important focusses of cattle-breeding in the Sudanic savanna zone. Today, the area is inhabited by three pastoral groups, the Buduma (Yedina), the Fulbe (Fulani) and the Shuwa Arabs, who possess different breeds of cattle. The Buduma are the old-established population, and their animals have extremely well been adapted to their aquatic habitat. Fulbe nomads infiltrated the region from the west from the 13th century onwards, and Shuwa Ara...

  5. 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.

  6. Pulmonary tuberculosis diagnostic delays in Chad: a multicenter, hospital-based survey in Ndjamena and Moundou

    Directory of Open Access Journals (Sweden)

    Ngangro Ndeindo

    2012-07-01

    Full Text Available Abstract Background Tuberculosis remains one of the leading causes of morbidity and mortality in low-resource countries. One contagious patient can infect 10 to 20 contacts in these settings. Delays in diagnosing TB therefore contribute to the spread of the disease and sustain the epidemic. Objectives The aim of this study was to assess delays in diagnosing tuberculosis and the factors associated with these delays in the public hospitals in Moundou and Ndjamena, Chad. Methods A structured questionnaire was administered to 286 new tuberculosis patients to evaluate patient delay (time from the onset of symptoms to the first formal or informal care, health-care system delay (time from the first health care to tuberculosis treatment and total delay (sum of the patient and system delays. Logistic regression was used to identify risk factors associated with long diagnostic delays (defined as greater than the median. Results and discussion The median [interquartile range] patient delay, system delay and total delay were 15 [7–30], 36 [19–65] and 57.5 [33–95] days, respectively. Low economic status (aOR [adjusted odds ratio] =2.38 [1.08-5.25], not being referred to a health service (aOR = 1.75 [1.02- 3.02] and a secondary level education (aOR = 0.33 [0.12-0.92] were associated with a long patient delay. Risk factors for a long system delay were a low level of education (aOR = 4.71 [1.34-16.51] and the belief that traditional medicine and informal care can cure TB (aOR = 5.46 [2.37-12.60]. Conclusion Targeted strengthening of the health-care system, including improving patient access, addressing deficiencies in health-related human resources, and improving laboratory networks and linkages as well as community mobilization will make for better outcomes in tuberculosis diagnosis.

  7. The Cenozoic volcanic province of Tibesti (Sahara of Chad): major units, chronology, and structural features

    Science.gov (United States)

    Deniel, C.; Vincent, P. M.; Beauvilain, A.; Gourgaud, A.

    2015-09-01

    Using both field relationships and some absolute ages, the sequence of volcanic units in the Cenozoic Tibesti Volcanic Province (TVP) (Chad) is established as follows: (1) plateau volcanism, between at least 17 and 8 Ma, consisting of flood basalts and silicic lava plugs, with intercalated ignimbritic sheets in the upper basalt succession increasing in amount upwards. Ages decrease from NE to SW, following the migration of the small NW-SE flexures concentrating the feeding dike swarms; (2) Late Miocene large central composite volcanoes exhibiting diverse and original structures. Some of them (Tarso Toon, Ehi Oyé, and Tarso Yéga) are located along a major NNE fault, representing the main tectonic direction in Tibesti since Precambrian times; (3) construction of three large ignimbritic volcanoes, associated with significant updoming of the basement, ending with the collapse of large calderas: Voon (about 5-7 Ma), Emi Koussi (2.4-1.33 Ma), and Yirrigué (0.43 Ma); (4) basaltic activity, starting at about 5-7 Ma, and essentially consisting of cinder cones and associated lava flows (Tarso Tôh, Tarso Ahon, and Tarso Emi Chi); and (5) final volcanic activity represented by post-Yirrigué caldera activity in the Tarso Toussidé Volcanic Complex, and especially Ehi Toussidé (the only active volcano in Tibesti), plus Ehi Timi and Ehi Mousgou volcanoes, similar to Ehi Toussidé. The two tectonic directions controlling some volcanic features of the province correspond to the major old lithospheric structures delimiting the volcanic province, namely, the great NW-SE Tassilian flexure to the SW and a major NE-NNE fault zone to the E. Unusual conditions of uplift and erosion in the TVP enable exceptional exposure of the internal structure of its volcanoes.

  8. Geochemical evidence for a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria

    Science.gov (United States)

    Bata, Timothy; Parnell, John; Samaila, Nuhu K.; Abubakar, M. B.; Maigari, A. S.

    2015-11-01

    Paleogeographic studies have shown that Earth was covered with more water during the Cretaceous than it is today, as the global sea level was significantly higher. The Cretaceous witnessed one of the greatest marine transgressions in Earth's history, represented by widespread deposition of sands directly on underlying basement. These sand bodies hold much of the world's heavy oil. Here, we present for the first time, geochemical evidence of a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria. Bima oil sand is similar to other Cretaceous oil sands, predominantly occurring at shallow depths on basin flanks and generally lacking a seal cover, making the oil susceptible to biodegradation. The bulk properties and distribution of molecular features in oils from the Bima oil sand suggest that they are biodegraded. Sterane maturity parameters and the trisnorhopane thermal indicator for the oils suggest thermal maturities consistent with oils generated as conventional light oils, which later degraded into heavy oils. These oils also show no evidence of 25-norhopane, strongly suggesting that biodegradation occurred at shallow depths, consistent with the shallow depth of occurrence of the Bima Formation at the study locality. Low diasterane/sterane ratios and C29H/C30H ratios greater than 1 suggest a carbonate source rock for the studied oil. The Sterane distribution further suggests that the oils were sourced from marine carbonate rocks. The C32 homohopane isomerization ratios for the Bima oil sand are 0.59-0.60, implying that the source rock has surpassed the main oil generation phase, consistent with burial depths of the Fika and Gongila Formations, which are both possible petroleum source rocks in the basin.

  9. 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.

  10. 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...

  11. 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

  12. 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

  13. Late Cretaceous intraplate silicic volcanism in the Lake Chad region: incipient continental rift volcanism vs. Cameroon Line volcanism

    Science.gov (United States)

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

    2015-12-01

    The crustal evolution of west-central Africa during the Cretaceous was directly related to plate motion associated with the opening of the central Atlantic Ocean. Late Cretaceous (~66 Ma) to recent magmatism related to the Cameroon Line stretches from Northern Cameroon (i.e. Golda Zuelva) to the Gulf of Guinea (i.e. Pagalu) and is considered to be due to mantle-crust interaction. The volcanic rocks at Hadjer el Khamis, west-central Chad, are considered to be amongst the oldest volcanic rocks of the Cameroon Line but their relationship is uncertain because they erupted during a period of a regional extension associated with the opening of the Late Cretaceous (~75 Ma) Termit basin. The silicic volcanic rocks can be divided into a peraluminous group and a peralkaline group with both rock types having similar chemical characteristics as within-plate granitoids. In situ U/Pb zircon dating yielded a mean 206Pb/238U age of 74.4 ± 1.3 Ma and indicates the rocks erupted ~10 million years before the next oldest eruption attributed to the Cameroon Line. The Sr isotopes (i.e. ISr = 0.7050 to 0.7143) show a wide range but the Nd isotopes (i.e. 143Nd/144Ndi = 0.51268 to 0.51271) are more uniform and indicate that the rocks were derived from a moderately depleted mantle source. Major and trace elemental modeling show that the silicic rocks likely formed by shallow fractionation of a mafic parental magma where the peraluminous rocks experienced crustal contamination and the peralkaline rocks did not. The silicic rocks are more isotopically similar to Late Cretaceous basalts in the Doba and Bongor basins (i.e. ISr = 0.7040 to 0.7060; 143Nd/144Ndi = 0.51267 to 0.51277) of southern Chad than to rocks of the Cameroon Line (i.e. ISr = 0.7026 to 0.7038; 143Nd/144Ndi = 0.51270 to 0.51300). Given the age and isotopic compositions, it is likely that the silicic volcanic rocks of the Lake Chad area are related to Late Cretaceous extensional tectonics rather than to Cameroon Line magmatism.

  14. Effects of climate variability on the land cover change and groundwater flow in the Lake Chad Basin

    Science.gov (United States)

    Lee, J.; Babamaaji, R. A.; Odor, R.; Park, C.

    2011-12-01

    Lake Chad is an endorheic lake located along the international borders of four countries Niger, Nigeria, Cameroon, and Chad. Over the past four decades, Lake Chad has shrunk from about 25,000 sq km in the 1960s to only ~3,000 sq km today. The Lake is shallow with an average water depth less than 8 m and has seasonally flooded wetlands extending along its shoreline. The climate is semi-arid with a long dry season and a short rainy season. The mean annual evaporation rate is about 1600 mm, which is more than double the mean annual rainfall rate of about 625 mm. Boronina and Ramillien (2008) shows that the northern part of the Lake Chad Basin has even less than 15mm of annual rainfall. These climate conditions of evaporation exceeding rainfall have caused a shortage of water recharge for both groundwater and surface water resources in the Basin. A distinctive feature of groundwater is the existence of piezometric depression in the southwest region of the Lake. The depression has been observed since the groundwater monitoring was performed in the 1960's, and the depression is still observed in the present day. The present study investigates how the climate variation in the last four decades affected the land cover change and the piezometric depression around the Lake. Landsat Multi-Spectral Scanner (MSS) images between 1975 and 1979, Landsat Thematic Mapper (TM) image for 1991, and Nigeriasat-1 for 2006 were classified for the production of land cover maps around the Lake. A maximum likelihood method was adopted for supervised classification of seven land types including: crop land, vegetation, grassland, water body, shrub land, farm, and bare soil, which were compared with unsupervised classification for 15 reference points per class. The overall accuracy from supervised classification is 93.33% for Nigeriasat-1 while the accuracy for Landsat is 95.24%. The producer's accuracy for vegetation in the 2006 Nigeriasat-1 image is 40% in comparison to the user's accuracy

  15. 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.

  16. Estimating population and livestock density of mobile pastoralists and sedentary settlements in the south-eastern Lake Chad area.

    Science.gov (United States)

    Jean-Richard, Vreni; Crump, Lisa; Abicho, Abbani Alhadj; Abakar, Ali Abba; Mahamat, Abdraman; Bechir, Mahamat; Eckert, Sandra; Engesser, Matthias; Schelling, Esther; Zinsstag, Jakob

    2015-01-01

    Mobile pastoralists provide major contributions to the gross domestic product in Chad, but little information is available regarding their demography. The Lake Chad area population is increasing, resulting in competition for scarce land and water resources. For the first time, the density of people and animals from mobile and sedentary populations was assessed using randomly defined sampling areas. Four sampling rounds were conducted over two years in the same areas to show population density dynamics. We identified 42 villages of sedentary communities in the sampling zones; 11 (in 2010) and 16 (in 2011) mobile pastoralist camps at the beginning of the dry season and 34 (in 2011) and 30 (in 2012) camps at the end of the dry season. A mean of 64.0 people per km2 (95% confidence interval, 20.3-107.8) were estimated to live in sedentary villages. In the mobile communities, we found 5.9 people per km2 at the beginning and 17.5 people per km2 at the end of the dry season. We recorded per km2 on average 21.0 cattle and 31.6 small ruminants in the sedentary villages and 66.1 cattle and 102.5 small ruminants in the mobile communities, which amounts to a mean of 86.6 tropical livestock units during the dry season. These numbers exceed, by up to five times, the published carrying capacities for similar Sahelian zones. Our results underline the need for a new institutional framework. Improved land use management must equally consider the needs of mobile communities and sedentary populations. PMID:26054513

  17. Estimating population and livestock density of mobile pastoralists and sedentary settlements in the south-eastern Lake Chad area

    Directory of Open Access Journals (Sweden)

    Vreni Jean-Richard

    2015-05-01

    Full Text Available Mobile pastoralists provide major contributions to the gross domestic product in Chad, but little information is available regarding their demography. The Lake Chad area population is increasing, resulting in competition for scarce land and water resources. For the first time, the density of people and animals from mobile and sedentary populations was assessed using randomly defined sampling areas. Four sampling rounds were conducted over two years in the same areas to show population density dynamics. We identified 42 villages of sedentary communities in the sampling zones; 11 (in 2010 and 16 (in 2011 mobile pastoralist camps at the beginning of the dry season and 34 (in 2011 and 30 (in 2012 camps at the end of the dry season. A mean of 64.0 people per km2 (95% confidence interval, 20.3-107.8 were estimated to live in sedentary villages. In the mobile communities, we found 5.9 people per km2 at the beginning and 17.5 people per km2 at the end of the dry season. We recorded per km2 on average 21.0 cattle and 31.6 small ruminants in the sedentary villages and 66.1 cattle and 102.5 small ruminants in the mobile communities, which amounts to a mean of 86.6 tropical livestock units during the dry season. These numbers exceed, by up to five times, the published carrying capacities for similar Sahelian zones. Our results underline the need for a new institutional framework. Improved land use management must equally consider the needs of mobile communities and sedentary populations.

  18. The Review of the Rate and the Hydrological Significance of the Fast Drying Up of Lake Chad

    Directory of Open Access Journals (Sweden)

    M.S. Kolawole

    2012-12-01

    Full Text Available Lake Chad is a tectonic lake formed as a result of earth movement. The lake is shared by five countries of Cameroon, Chad, Nigeria, Niger and the Central Africa Republic. Over thirty million people depend solely on the renewable natural resources of the basin for agriculture, animal husbandry, fisheries, recreation and other socio-economic activities. The Lake is in a hot and arid climate, where the rate of evaporation exceeds precipitation. The essence of this study is to access the causes of the decline in volume of the Lake and to proffer solutions. Satellite imageries of 1963 to 2000 were observed and they reveal that the lake has been environmentally reduced to cover only about 3% of its 1963 area size. The hydrostratigraphy and hydrodynamics play a role in the recharge of the lake. The upper aquifer of the southwest portion of the basin consists of a Quaternary phreatic aquifer made up of fine-grained sediments approximately 30 m thick and is hydrologically connected to the Lake. Anthropogenic influence on the Lake is worrisome. The excessive use of lake waters for irrigation and construction of dams are causing a massive reduction in the water volume. A similar environmental disaster occurred in Lake Aral in the Former Soviet Union. Unsustainable water management is complicated by lack of proper irrigation systems and resulting in salt accumulation in the soil. The countries of the LCBC have drawn out modalities for saving the lake which includes channeling the Bangui River from the Central Africa Republic to the lake. Anthropogenic activities need to monitored and planned in such a way that runoffs are redirected into the lake. A proper articulated hydrogeosystematics is required to solve the ecological mayhem and to safe the riparian countries from hydrogeonthropocide.

  19. Safety and Immunogenicity of Heterologous Prime-Boost Immunisation with Plasmodium falciparum Malaria Candidate Vaccines, ChAd63 ME-TRAP and MVA ME-TRAP, in Healthy Gambian and Kenyan Adults

    OpenAIRE

    2013-01-01

    Background Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified vaccinia Virus Ankara (MVA) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. ChAd63-MVA expressing the Plasmodium falciparum pre-erythrocytic antigen ME-TRAP (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing ...

  20. 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

  1. 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

  2. Access to antiretroviral treatment, issues of well-being and public health governance in Chad: what justifies the limited success of the universal access policy?

    OpenAIRE

    Azétsop, Jacquineau; Diop, Blondin A

    2013-01-01

    Universal access to antiretroviral treatment (ART) in Chad was officially declared in December 2006. This presidential initiative was and is still funded 100% by the country’s budget and external donors’ financial support. Many factors have triggered the spread of AIDS. Some of these factors include the existence of norms and beliefs that create or increase exposure, the low-level education that precludes access to health information, social unrest, and population migration to areas of high e...

  3. Lake Chad sedimentation and environments during the late Miocene and Pliocene: New evidence from mineralogy and chemistry of the Bol core sediments

    Science.gov (United States)

    Moussa, Abderamane; Novello, Alice; Lebatard, Anne-Elisabeth; Decarreau, Alain; Fontaine, Claude; Barboni, Doris; Sylvestre, Florence; Bourlès, Didier L.; Paillès, Christine; Buchet, Guillaume; Duringer, Philippe; Ghienne, Jean-François; Maley, Jean; Mazur, Jean-Charles; Roquin, Claude; Schuster, Mathieu; Vignaud, Patrick; Brunet, Michel

    2016-06-01

    This study presents mineralogical and geochemical data from a borehole drilled near the locality of Bol (13°27‧N, 14°44‧E), in the eastern archipelago of the modern Lake Chad (Chad). Samples were taken from a ∼200 m long core section forming a unique sub-continuous record for Central Africa. Among these samples, 25 are dated between 6.4 and 2.4 Ma. Dominant minerals are clays (66% average) mixed with varying amounts of silt and diatomite. The clay fraction consists of Fe-beidellite (87% average), kaolinite, and traces of illite. Clay minerals originate from the erosion of the vertisols that surrounded the paleolake Chad. Sedimentological data indicate that a permanent lake (or recurrent lakes) existed from 6.7 until 2.4 Ma in the vicinity of Bol. By comparison with modern latitudinal distribution of vertisols in Africa the climate was Sudanian-like. Changes in the sedimentation rate suggest a succession of wetter and dryer periods during at least six million years in the region during the critical time period covering the Miocene-Pliocene transition.

  4. 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

    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......DS2-VASc score significantly improved the predictive value of the CHADS2 score alone and a CHA2DS2-VASc score=0 could clearly identify 'truly low risk' subjects. Use of the CHA2DS2-VASc score would significantly improve classification of AF patients at low and intermediate risk of stroke, compared...

  5. 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

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

    Science.gov (United States)

    Bouchez, C.; Goncalves, J.; Deschamps, P.; Vallet-Coulomb, C.; Hamelin, B.; Doumnang, J.-C.; Sylvestre, F.

    2015-10-01

    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 center 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 behavior 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 J. C. Bader, J. Lemoalle, and M. Leblanc (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 (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 kilometers 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

  7. 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.

  8. 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

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

    Directory of Open Access Journals (Sweden)

    Alessandro Leone

    2015-08-01

    Full Text Available 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.

  10. 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

    2015-01-01

    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. PMID:26274956

  11. 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

    2015-01-01

    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. PMID:26274956

  12. Structure and dynamics of myxosporean parasites component communities in two freshwater Cichlids in the Chari River (Republic of Chad).

    Science.gov (United States)

    Ousman, Abakar; Félix, Bilong Bilong Charles; Thomas, Njiné; Abraham, Fomena

    2007-03-01

    Myxosporean parasites of two freshwater Tilapia species from the Chari River, Chad Republic, Oreochromis niloticus and Sarotherodon galilaeus, were investigated from November 2001 to October 2002. A total of 360 specimens per Cichlid species were examined. Eleven parasite species were found in both cases with different prevalences. Myxobolus agolus, M. brachysporus, M. clarii, M. cichlidarum, M. heterosporus, M. tilapiae and M. camerounensis in O. niloticus) appeared common while M. equatorialis, M. nyongana (and M. camerounensis in S. galilaeus) were secondary; lastly M. israelensis (and M. kainjiae in O. niloticus) were rare. The gills, fins, eyes and teguments were preferential locations of cysts building pathogens while the kidneys then the gall bladder were most commonly infected by myxosporean spores. In the Chari ecosystem, no significant host sex and size effects were found for the parasite cystic load. A clear seasonal occurrence was observed for most of these pathogens. In the view of pathogenic control, this study raised the necessity in a farm fish station to identify the most important myxosporean species and the period of their potential demographic explosion. PMID:19069850

  13. 非瓣膜性心房纤颤CHADS2评分低中危患者脑卒中危险因素分析%Risk Factors for Stroke in Non-valvular Atrial Fibrillation Patients With Low-intermediate CHADS2 Risk Score

    Institute of Scientific and Technical Information of China (English)

    刘燕; 龚辉

    2015-01-01

    Objective To investigate the risk factors for stroke in non-valvular atrial fibrillation( NVAF)patients with low-intermediate CHADS2 risk score. Methods We enrolled 98 NVAF patients complicated with stroke who were admitted into the Neurology Department of Jinshan Hospital Affiliated to Fudan University from January 2009 to December 2012. CHADS2 scores and CHA2DS2-VASc scores were calculated. The subjects who had low-intermediate CHADS2 risk scores(0~2)were assigned into case group(n=58),and another 53 NVAF patients without stroke who were admitted into the same department during the same period were enrolled as control group. Comparison was made between the two groups in clinical features,cardiac ultrasound results and laboratory examination results. Multivariate non-conditional logistic regression analysis was conducted to determine the influencing factors. Results Of the 98 NVAF patients complicated with stroke,58 patients(59. 2%)had low-intermediate CHADS2 risk score,and 95 patients(96. 9%)had high CHA2DS2-VASc score(≥2). The case group was lower(P 5. 72 mmol/L ) are independent risk factors for stroke in NVAF patients with low-intermediate CHADS2 score. CHA2DS2-VASc score system is advantageous than CHADS2 score system in the risk classification of NVAF patients with low -intermediate risk of stroke. The application of CHA2DS2-VASc score system in China needs further verification and adjustment.%目的:探讨非瓣膜性心房纤颤( NVAF) CHADS2评分低中危患者发生脑卒中的危险因素。方法选取2009年1月—2012年12月在复旦大学附属金山医院神经内科住院的 NVAF 合并脑卒中患者( n =98),计算CHADS2评分及CHA2DS2-VASc评分,筛选CHADS2评分低中危(0~2分)患者为病例组( n=58),选取同期在该院心内科住院的NVAF不合并脑卒中患者为对照组( n=53)。比较两组的临床特征、心脏超声及实验室检查结果等,脑卒中发生的影响因素分析采用多

  14. 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

    Introduction 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. Methods 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. Results 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. Conclusion 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. PMID:24106572

  15. "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

  16. 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

  17. 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...... 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...

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

    Science.gov (United States)

    Svendsen, Jesper Hastrup; Nielsen, Jens Cosedis; Darkner, Stine; Jensen, Gunnar Vagn Hagemann; Mortensen, Leif Spange; Andersen, Henning Rud

    2013-01-01

    Objective 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 stroke and death. Design Prospective cohort study. Settings All Danish pacemaker centres and selected centres in the UK and Canada. Patients Risk factors were recorded prior to pacemaker implantation in 1415 patients with SSS participating in the Danish Multicenter Randomized Trial on Single Lead Atrial Pacing versus Dual Chamber Pacing in Sick Sinus Syndrome (Danpace) trial. Development of stroke was assessed at follow-up visits and by evaluation of patient charts. Mortality was assessed from the civil registration system. Interventions Patients were randomised to AAIR (N=707) or DDDR pacing (N=708). Main outcome measures Stroke and death during follow-up. Results Mean follow-up was 4.3±2.5 years. In the AAIR group 6.9% patients developed stroke versus 6.1% in the DDDR group (NS). There was a significant association between CHADS2 score and the development of stroke (HR 1.41; 95% CI 1.22 to 1.64, p<0.001). CHA2DS2-VASc score was also significantly associated with stroke (HR 1.25; CI 1.12 to 1.40, p<0.001). CHADS2 score (HR 1.46; CI 1.36 to 1.56, p<0.001) and CHA2DS2-VASc score (HR 1.39; CI 1.31 to 1.46, p<0.001) were associated with mortality. Results were still significant after adjusting for AF and anticoagulation therapy. Conclusions CHADS2 and CHA2DS2-VASc score are associated with increased risk of stroke and death in patients paced for SSS irrespective of the presence of AF. PMID:23539553

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

    OpenAIRE

    Svendsen, Jesper Hastrup; Nielsen, Jens Cosedis; Darkner, Stine; Jensen, Gunnar Vagn Hagemann; Mortensen, Leif Spange; Andersen, Henning Rud; . .

    2013-01-01

    Objective 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 stroke and death. Design Prospective cohort study. Settings All Danish pacemaker centres and selected centres in the UK and Canada. Patients Risk factors were recorded prior to pacemaker implan...

  20. 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. PMID:22160444

  1. Assessing health impacts of the Chad-Cameroon petroleum development and pipeline project: challenges and a way forward

    International Nuclear Information System (INIS)

    Health impact assessment (HIA) of projects, programmes and policies is increasingly recognized as a powerful methodology for mitigating negative health impacts and enhancing equitable and sustainable development, yet applications in the developing world are sparse. Here, we focus on a large infrastructure development in sub-Saharan Africa, namely the Chad-Cameroon petroleum development and pipeline project. We adapted a five-step process for HIA, consisting of (1) screening of project documents, (2) profiling of affected communities, (3) identifying priority health areas, predicting potential impacts, and proposing mitigation measures, (4) implementing interventions, and (5) monitoring and evaluation of health impacts. We found that project scoping was broad, including extensive environmental and social assessments. Innovative features of the project include the high degree of public-private partnerships, and the management of oil revenues for purposes of poverty reduction. The project also addressed occupational and public health issues, and developed and implemented measures to prevent or mitigate potential health impacts. However, there was a disproportionate emphasis on workers' health, particularly on the prevention/mitigation of construction-related injuries, sexually transmitted infections (STIs; mainly HIV/AIDS), and malaria. Health impacts among surrounding communities, and cumulative health impacts in the larger region were not considered in a comprehensive way. Concluding, there is a need for a more systemic approach to HIA and its incorporation within 'Equator Principles', which are increasingly adopted by the international financial community. This process would include clarification of corporate social responsibility beyond the project fence line in the mitigation of health problems at regional levels. Finally, we propose the establishment and running of a longitudinal demographic surveillance system, which--coupled with regular household surveys

  2. 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.

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

    Science.gov (United States)

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

    2014-01-01

    Abstract Objective 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. Methods 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. Findings 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. Conclusion 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. PMID:24623901

  4. 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

  5. Investigation of groundwater resources in the Komadugu Yobe Valley (Lake Chad Basin, Niger) using MRS and TDEM methods

    Science.gov (United States)

    Descloitres, M.; Chalikakis, K.; Legchenko, A.; Moussa, A. M.; Genthon, P.; Favreau, G.; Le Coz, M.; Boucher, M.; Oï, M.

    2013-11-01

    Groundwater resources quantification and management is a key issue for agricultural development in the Komadugu Yobe (KY) River valley region in the semiarid part of the Lake Chad Basin. To improve the knowledge of available groundwater resources in this poorly-documented area, a geophysical survey across the river valley was conducted near the town of Diffa, southeast Niger. The goal was to estimate the hydrogeological properties of Quaternary formations to a depth of ˜100 m. Numerical modeling showed that sedimentary deposits composed of thin clayey, loamy, and sandy layers could not be accurately resolved in detail by non-invasive geophysical methods due to the limited spatial resolution of the methods. The use of the Time Domain Electromagnetic (TDEM) method alone was not sufficient to estimate aquifer parameters and the Magnetic Resonance Sounding method (MRS) was used to supplement the geophysical dataset. A twelve kilometer long profile (117 TDEM and 11 MR soundings) was surveyed across the valley to evaluate changes in hydrogeological properties of the Quaternary aquifer from the middle of the river valley to the surrounding sandy plain area. Our results show that the Quaternary aquifer below the KY valley differs from its surroundings and it can be described as follows: (a) the thickness of the KY aquifer ranges from 30 to ˜60 m and is limited at depth by electrically conductive clay layer, (b) at a depth of ˜70-80 m, TDEM soundings show a continuous conductive substratum (resistivity is ˜2 Ω m), attributed to Pliocene clayey formations, (c) the KY valley aquifer may have a larger volume of unconfined groundwater than the surrounding plain aquifer area (MRS water contents of 20-25% and ˜15% respectively), (d) the KY aquifer transmissivity estimated from MRS data is higher than values derived from pumping tests conducted outside the river valley. This study confirms that the Komadugu Yobe valley aquifer represents a significant resource for future

  6. 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.

  7. Understanding and Managing Natural and Human-Induced Pressures on Ecosystem Health and Environmental Sustainability in the Lake Chad Basin (LCB)

    Science.gov (United States)

    Adegoke, J. O.; Lee, J.; Goni, I. B.; Iliya, A.; Muhammad, S.; Bassi, S.

    2009-12-01

    Several countries in Africa face multiple challenges arising from rapid degradation of critical natural resources, and a long list of other environmental constraints. These pressures include a cycle of inadequate rainfall in several regions, and an unsustainable increase in the pressures on available resources due to a rapidly growing population, urbanization and mineral resource extraction. The complex interplay of these pressures is, perhaps, nowhere more evident on the African continent than in the Lake Chad Basin (LCB). Lake Chad, once one of Africa’s largest freshwater lakes, is now only a shadow of what it used to be. Recent estimates of changes in the surface water of the lake indicate that the surface area of lake decreased by more than 80 percent within the last 35 years. The political and socio-economic context within which these changes are taking place is complex and reflects the intense competition for a dwindling resource by multiple stakeholders. Scientists at the University of Missouri Kansas City working with colleagues at the University of Maiduguri, Nigeria, agencies of the Nigerian government and water resource management authorities within the LCB have developed a multidisciplinary partnership to advance scientific understanding of the nature of these pressures; the driving forces behind them; and the complex interactions between these drivers and the socio-economic fabric of the communities that depend on these resources for their livelihood. In this paper, we discuss some of the early results of the research collaboration and highlight some of the unique aspects of the institutional framework within which this international collaboration is being carried out.

  8. Changes in growth and yield attributes of two selected maize varieties as influenced by application of chemical (npk) and organic (bat's manure) fertilizers in pala (chad) grown field

    International Nuclear Information System (INIS)

    The present experiment was conducted in Pala, region of the Mayo-Kebi West division, in a contribution to improve maize production in Chad. The work was oriented towards the evaluation of the interactions between chemical (NPK) and organic (bat's manure) fertilizers on growth and yield attributes of TZEE-W and IB selected maize varieties. The experimental design was a (5x2)x4 factorial design in which the main factor was the proportion of organic/chemical fertilizer (%), and the maize variety as the secondary factor, comprising the following six treatments repeated four times: control (T0) with 0 % NPK and 0 % bat's manure; T1 with 100% NPK; T2 with 100% bat's manure; T3 with 75% NPK and 25% bat's manure; T4 with 75% bat's manure and 25% NPK; T5 with 50% bat's manure and 50% NPK. Results show a variation in experimental soils pH of treatments from 5.91 to 7.92, depending on the proportion of the fertilizers applied. There were significant yield differences among treatments, as well as maize varieties. The 50% NPK+50% bat's manure was found as the best treatment to significantly (p<0.0001) enhance the yield of IB (51.2 t/ha) and TZEE-W (37.9 t/ha) maize varieties compared to their respective controls (7.25 t/ha and 6.76 t/ha). These results suggest that the combination at equal proportion of NPK and bat's manure could be recommended to sustainably improve maize production in Pala-Chad, thus with a considerable alleviation of the pollution risks that have been attributed to chemical fertilizer. (author)

  9. 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

  10. Access to antiretroviral treatment, issues of well-being and public health governance in Chad: what justifies the limited success of the universal access policy?

    Science.gov (United States)

    Azétsop, Jacquineau; Diop, Blondin A

    2013-01-01

    Universal access to antiretroviral treatment (ART) in Chad was officially declared in December 2006. This presidential initiative was and is still funded 100% by the country's budget and external donors' financial support. Many factors have triggered the spread of AIDS. Some of these factors include the existence of norms and beliefs that create or increase exposure, the low-level education that precludes access to health information, social unrest, and population migration to areas of high economic opportunities and gender-based discrimination. Social forces that influence the distribution of dimensions of well-being and shape risks for infection also determine the persistence of access barriers to ART. The universal access policy is quite revolutionary but should be informed by the systemic barriers to access so as to promote equity. It is not enough to distribute ARVs and provide health services when health systems are poorly organized and managed. Comprehensive access to ART raises many organizational, ethical and policy problems that need to be solved to achieve equity in access. This paper argues that the persistence of access barriers is due to weak health systems and a poor public health leadership. AIDS has challenged health systems in a manner that is essentially different from other health problems. PMID:23902732

  11. Isotopic and hydrodynamic approaches in the quaternary aquifer of Lake Chad basin in Niger as indicators of present and past hydrological processes

    International Nuclear Information System (INIS)

    The studied area is the Niger part of the Quaternary aquifer in the large endoreic Lake Chad basin. In a semi-arid to arid environment, it covers almost 200 000 km2 between latitudes 13 deg and 14,5 deg N, in the south-eastern part of Niger and is the upper layer of a Plio-Quaternary continental reservoir. Because of the scarcity of surface water in the region, groundwater is the only permanent resource for the population. We linked the environmental isotope and hydrodynamic approaches to understand the present state of the phreatic aquifer and its evolution with time. Groundwater samples were collected only from wells for chemical, stable isotope (δ18O, δ2H) and radioisotope (A14C, δ13C) analyses during several field trips between 1997 and 2002. At the same time, depths to the water table were systematically measured to complete older information. Groundwater flows slowly from the north and the west to Lake Chad, in the centre of the basin. All isotopic data are below the meteoric water line in a δ2H vs δ18O diagram, sign of evaporation. The results vary from -5,8 per mille to +8,5 per mille vs SMOW for δ18O and -55 per mille to +38 per mille for δ2H. This important range and the heterogeneity of isotope distribution show that the recharge is not diffuse but mainly occurs in several areas and is highly variable. Four regions were identified as getting a present significant recharge: (i) On the south west, the Manga grassland forms a late Pleistocene erg reworked by more recent aeolian processes with radiocarbon activity of groundwater between 80 pmc and 98 pmc. The hydrodynamic confirmation is the seasonal presence of small lakes in some interdune depressions in hydraulic continuity with the aquifer. (ii) The flooding of the Komadugu Yobe, a non perennial river, is a large source of recharge as shown by the seasonal piezometric variation and isotopic results (∼ -1 per mille vs SMOW for δ18O in the aquifer 15 km away from the river bed, very similar to

  12. Chemical composition and distribution of Trona samples (A case study of Yunusari/Yusufari Local Government Areas of Yobe State and, Chad and Niger Republic)

    International Nuclear Information System (INIS)

    Trona (NO2CO3.NaHCO3.2H2O), is one of the complex salts that occur naturally as white crystalline hydrated salt which originate from the weathering activity of igneous rock. Eight major elements make up about 98% by weight of magmas which constitute the igneous rocks. These elements are O, Si, AI, Fe, Ca, Na, K and Mg, which is an indication that trona is a chemical combination of these elements. In Nigeria and some other parts of the world, trona is commonly consumed in both raw form and along with some cooked food irrespective of the potential risk effects. In addition, it is primarily utilized in various forms such as food additive, medicine etc. The current study investigated the composition and distribution of chemical elements in trona samples collected from three different locations - Yunusari and Yusufari local government areas of Yobe State, Nigeria and products transported into the country from Chad and Niger Republic, using X-ray fluorescence analysis. A total of 21 elements were detected in varying ppm, with K, Cu, As and Pb mean and range as 88371±12887 (43700-33000), 586±30 (404-882), 272±11 (184-389) and 396±16 (274-561) respectively.

  13. Mejora del acceso y la calidad de las infraestructuras educativas en la escuela de primaria de Baiwangué en la región de Guerá, Chad

    OpenAIRE

    Andrés Sancho, Lorena; Sánchez García, Gonzalo; Sánchez Carrera, Verónica

    2009-01-01

    El presente proyecto busca mejorar el acceso y las infraestructuras educativas de 19 escuelas de primaria identificadas por la contraparte con el fin de crear un modelo educativo de calidad en la región de Guéra en el Chad. Para ello, se va a basar en una de las 3 escuelas piloto identificadas por la contraparte, la escuela primaria de Baiwangué que cuenta con 261 alumnos y alumnas y un cuerpo docente de 5 personas. Se pretende conseguir una mejora de las infraestructuras así como favor...

  14. 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.

  15. 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

  16. 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.

  17. Radiological analysis of some Trona samples found in Yobe State: A case study of Yunusari/Yusufari local government areas of Yobe State and, Chad and Niger Republics

    International Nuclear Information System (INIS)

    Trona is one of the complex salts that occur naturally as white crystalline hydrated salt which originated from the weathering activity of igneous rock and igneous rock has been classified active. This becomes an issue of concern since trona is consumed both raw and in cooked food and this formed a drive in the assessment of radiological effects of trona to consumers. The study investigated radiological problems of trona via gamma spectrometry analysis of samples collected from Yunusari and Yusufari Local Government Areas of Yobe State, Nigeria and products imported into the country from Chad and Niger Republics. The samples were assayed for NORMs using 7.62cm x 7.62cm NaI(Tl) detector and each gamma spectrum collected for 29,000 seconds. Spectral interpretation was conducted via ORTEC pulser system coupled to computerised MEASTRO card. The mean activity concentration levels of the natural radionuclides 40K, 226Ra and 232Th obtained from Yunusari are 380.02± 5.17, 23.17±1.51, and 77.50±1.44 Bq/Kg and that of Yusufari are 236.51±3.41, 276.94±2.48 and 35.44±1.14 Bq/Kg, respectively. The imported samples measured 595.55±3.55, 24.49±1.98 and 71.52±0.81 for 40K, 226Ra and 232Th respectIvely. 226Ra content is an issue of serious concern.

  18. 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

  19. 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

  20. 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

  1. 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

    2016-01-01

    ABSTRACT 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

  2. 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

  3. 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

  4. 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.

  5. Uso de imágenes de satélite para el análisis y seguimiento de los recursos hídricos disponibles en países en vías de desarrollo: aplicación al lago Chad-África

    OpenAIRE

    Romero Hernández, Claudia Patricia; Carmona Moreno, César; Pedregal Mateos, Belén; Bernal Márquez, Manuel

    2010-01-01

    El principal objetivo del estudio piloto sobre el lago Chad realizado por el JRC-IES era determinar la viabilidad de los datos de observación de la Tierra para la caracterización y seguimiento de superficies acuáticas y vegetación colindante. En este trabajo se plantea el desarrollo de una metodología que permita la validación de los primeros resultados. En el caso analizado se procesó una serie temporal de imágenes (1998-2009) de la que se trataron, para cada año y para cada estación (per...

  6. Gold and uranium metallogenesis in the framework of Neo-proterozoic crust growth and differentiation: example of the Mayo-Kebbi Massif (Chad) in the Central Africa Orogenic belt

    International Nuclear Information System (INIS)

    The Mayo Kebbi massif located in southwestern Chad between the Congo craton in the South, the West African craton in the west and the Sahara meta-craton to the east exposes a segment of Neo-proterozoic juvenile crust accreted in the Central African orogenic belt during the Pan African orogeny. It consists of two greenstone belts (Zalbi and Goueygoudoum) separated by the May Kebbi calc-alkaline batholith complexes and intruded by calc-alkaline high-K granitic plutons. The whole is covered by Phanerozoic sedimentary formations. The greenstone belts contain sulphide zones hosted mainly by meta-plutonic rocks (granodiorites) and meta-basalts and meta-volcaniclastics. The mineralization comprises pyrite, pyrrhotite, arsenopyrite, chalcopyrite, pentlandite, pentlandite silver, pentlandite cobaltiferous, sphalerite, cobaltite. These sulphides are disseminated, aggregated in form of layers or are filling veins and cracks. The greenstones also contain quartz veins with calcite and chlorite comprising a mineralization made of pyrite, chalcopyrite, galena and gold. Gold is present both as native crystals and as electrum. The high-K calc-alkaline Zabili granitic pluton hosts uranium mineralization related to a superposition of: (1) ductile deformation and metasomatic alteration implying the interaction between magmatic minerals with a Na-rich fluid, of potential magmatic origin, coeval to the main deposition of uranium oxides, followed by (2) brittle deformation and deposition of secondary hydrated uranium silicates involving a Na-Ca-rich fluid. We propose that these uranium mineralizations represent the extreme expression of crustal differentiation as a result of Pan-African reworking of a Neo-proterozoic juvenile crustal segment. (author)

  7. 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 marine and terrestrial ecosystems.

  8. 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

  9. Enamel hypoplasia in a pliocene hominid from Chad.

    Science.gov (United States)

    Brunet, Michel; Fronty, Pierre; Sapanet, Michel; de Bonis, Louis; Viriot, Laurent

    2002-01-01

    Abel is the first Australopithecine known west of the East African Rift Valley. The fossil finds include a perisymphyseal fragment of an adult mandible with well-preserved crowns of the right I2-P4 and the left C-P4. Abel's dentition displays many enamel defects, which are described in detail for each tooth. Pitting affected every tooth, while larger, shallow depressions were observed on the canines alone. From two to four pit bands occurred on the different teeth, each resulting from a separate hypoplastic episode. In modern humans, a large number of causes, both environmental and genetic, have been suggested for such enamel defects. It seems probable that Abel's pathology was systemic. However, the occurrence of a number of bands and the variable intensity of the attacks make it difficult to say whether there was a single, repetitive cause or different etiologies. Possible causes discussed here include recurrent fevers and seasonal nutritional deficiencies. PMID:12489142

  10. Mineralogical controls on dust emissions in the Bodele Depression, Chad

    Science.gov (United States)

    Surface mineralogy is critical in the understanding of aeolian processes, however its role in dust production is currently underestimated. Recent research indicates that discrepancies between predicted and observed dust loads by dust models may be attributed to inadequacies within their associated d...

  11. Petroleum and natural gas economy in Arab Countries and in Benin, Chad Cameroon, Namibia, Nigeria

    International Nuclear Information System (INIS)

    This paper gives informations on petroleum and natural gas industry, petroleum market and prices, trade and contracts, prospection and production. In Saudi Arabia, Saudi Aramco has begun the works to increase the production capacity of the petroleum refinery of Ras Tanura. In Kuwait, the cost of the retrofitting and development programs for the petroleum field is evaluated to 4 milliards $. Several contracts have been signed in Tunisia and in Nigeria for the attribution of exploration permits. A cooperation agreement has been signed, in Taiwan, between Total and Chinese Petroleum Corporation, which allows the establishment of joint ventures for the development of petroleum exploration in Far East. Petroleum exploration has begun in Namibia where Norsk Hydro has achieved the interpretation of seismic studies and will drill a first exploration well. In Egypt, petroleum production is stabilized at a level of 870000 barrels per day and the transport capacity of Sumed pipeline will increase from 80 to 117 millions tons per year in 1994

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

    NARCIS (Netherlands)

    Bouwknegt, Thijs

    2015-01-01

    From July 20th 2015, the former Chadian dictator, Hissène Habré, will stand 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 o

  13. 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

  14. 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…

  15. Possibilities of a concerted management of the areas of natural vegetation around Zakouma national park (Chad)

    OpenAIRE

    Hanon, Laurence

    2008-01-01

    R É S U M ÉI. Actuellement, en Afrique sub-saharienne, les acteurs de la conservation considèrent que lasurvie à long terme de la faune sauvage ne peut être assurée que par le maintien de son habitaten dehors des aires de conservation intégrale. Dans cette optique, les projets de conservationtentent de préserver des étendues de végétation naturelle au sein de « zones tampons » ou de« corridors de migration » dans la périphérie des aires protégées. Cette thèse s’est intéressée aux possibilités...

  16. Operational performance and analysis of two rabies vaccination campaigns in N'Djamena, Chad.

    Science.gov (United States)

    Léchenne, Monique; Oussiguere, Assandi; Naissengar, Kemdongarti; Mindekem, Rolande; Mosimann, Laura; Rives, Germain; Hattendorf, Jan; Moto, Daugla Doumagoum; Alfaroukh, Idriss Oumar; Zinsstag, Jakob

    2016-01-20

    Transmission of rabies from animals to people continues despite availability of good vaccines for both human and animal use. The only effective strategy to achieve elimination of dog rabies and the related human exposure is to immunize dogs at high coverage levels. We present the analysis of two consecutive parenteral dog mass vaccination campaigns conducted in N'Djamena in 2012 and 2013 to advocate the feasibility and effectiveness for rabies control through proof of concept. The overall coverage reached by the intervention was >70% in both years. Monthly reported rabies cases in dogs decreased by more than 90% within one year. Key points were a cooperative collaboration between the three partner institutions involved in the control program, sufficient information and communication strategy to access local leaders and the public, careful planning of the practical implementation phase and the effective motivation of staff. The dynamic and semi to non-restricted nature of dog populations in most rabies endemic areas is often considered to be a major obstacle to achieve sufficient vaccination coverage. However, we show that feasibility of dog mass vaccination is highly dependent on human determinants of dog population accessibility and the disease awareness of dog owners. Consequently, prior evaluation of the human cultural and socio-economic context is an important prerequisite for planning dog rabies vaccination campaigns. PMID:26631415

  17. 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.

  18. 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.

  19. 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.

  20. WIESE, Martin, 2004, Health-vulnerability in a complex crisis situation. Implications for providing health care to a nomadic people in Chad

    OpenAIRE

    Baroin, Catherine

    2007-01-01

    Le titre un peu rébarbatif de ce livre reflète mal son contenu. Il ne s’agit pas uniquement de santé en effet, mais d’un bilan global, et tout à fait remarquable, de la situation socio-économique actuelle de deux groupes de pasteurs nomades du Tchad. Ceux-ci se côtoient sans se mêler sur des circuits de transhumance différents, entre le Kanem et le Bahr-el-Ghazal au nord, et le Chari-Baguirmi au sud. Les deux groupes en question sont d’une part des Arabes Juhayna, éleveurs de dromadaires réfu...

  1. 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

  2. Raptor habitat use in the lake Chad basin: insights into the effect of flood-plain transformation on afrotropical and paleartic raptors

    NARCIS (Netherlands)

    Buij, R.; Croes, B.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

  3. Lise GARON, Azzedine MANSOUR et El-Mostapha CHADLI (dir.) (2008), L’Islam et l’Occident. Biopsies d’un dialogue

    OpenAIRE

    Riondet, Odile

    2013-01-01

    Voici un ouvrage curieux, dès le départ, par son titre et sa typographie. Car il annonce le dialogue entre deux termes hétérogènes (une religion et un ensemble géopolitique pas forcément religieux), et il le fait en utilisant les majuscules au rebours des conventions habituelles, traitant l’islam comme une zone géographique, ce qu’il n’est pas, et considérant que l’Occident a une unité religieuse, ce qui mérite discussion. Il nous semble que l’intérêt et les limites de cet ouvrage sont précis...

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

    OpenAIRE

    Xing YL; Ma Q; Ma XY; Wang CY; Zhang D; Sun Y

    2016-01-01

    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&...

  5. Using self-organizing maps to infill missing data in hydro-meteorological time series from the Logone catchment, Lake Chad basin.

    Science.gov (United States)

    Nkiaka, E; Nawaz, N R; Lovett, J C

    2016-07-01

    Hydro-meteorological data is an important asset that can enhance management of water resources. But existing data often contains gaps, leading to uncertainties and so compromising their use. Although many methods exist for infilling data gaps in hydro-meteorological time series, many of these methods require inputs from neighbouring stations, which are often not available, while other methods are computationally demanding. Computing techniques such as artificial intelligence can be used to address this challenge. Self-organizing maps (SOMs), which are a type of artificial neural network, were used for infilling gaps in a hydro-meteorological time series in a Sudano-Sahel catchment. The coefficients of determination obtained were all above 0.75 and 0.65 while the average topographic error was 0.008 and 0.02 for rainfall and river discharge time series, respectively. These results further indicate that SOMs are a robust and efficient method for infilling missing gaps in hydro-meteorological time series. PMID:27282595

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

    Czech Academy of Sciences Publication Activity Database

    Černý, Viktor; Fernandes, V.; Costa, M. D.; Hájek, Martin; Mulligan, C. J.; Pereira, L.

    2009-01-01

    Roč. 9, č. 63 (2009), s. 1-9. ISSN 1471-2148 R&D Projects: GA ČR GA206/08/1587 Institutional research plan: CEZ:AV0Z80020508 Keywords : migration * Chadic * phylogeography Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 4.294, year: 2009 http://www.biomedcentral.com/1471-2148/9/63

  7. Economía política de la reforma de las políticas del Banco Mundial y el Fondo Monetario Internacional en África subsahariana. El caso del Chad.

    OpenAIRE

    Colom Jaén, Artur

    2009-01-01

    A mediados de los 90 emerge un cuestionamiento del enfoque del ajuste estructural promovido por el Banco Mundial y el FMI en los países en desarrollo, especialmente en África, que lleva a estas instituciones a cambiar su discurso. Las preguntas que guían la investigación son (1) si estos cambios suponen un cuestionamiento real del enfoque del ajuste estructural, y (2) si estos cambios pueden modificar la inserción periférica de África en la economía mundial. El marco teórico del que se parte ...

  8. 2009年乍得尼日尔和尼日利亚脑膜炎流行情况%Meningitis in Chad, Niger and Nigeria: 2009 epidemic season

    Institute of Scientific and Technical Information of China (English)

    WHO; 宁桂军

    2010-01-01

    @@ 1 背景脑膜炎奈瑟菌(Neisseria meningitidis,Nm)是非洲脑膜炎地带脑膜炎流行的主要病原,所引起的脑膜炎球菌疾病占医疗机构中细菌性脑膜炎住院病例的80%~95%.其他大部分细菌性脑膜炎病例由肺炎链球菌和b型流行性感冒嗜血杆菌(Haemophilus Influenzae Type b,Hib)引起.非洲脑膜炎地带位于非洲撒哈拉沙漠以南,西起寒内加尔,东至埃塞俄比亚,覆盖21个国家,总人口约4亿.该地带脑膜炎球菌疾病特点是高度地方流行、季节件复发和周期性大爆发,年发病率可岛达1000/10万.2003~2009年,该地带脑膜炎流行导致了近27万病例,死亡2.5万人.

  9. Analysis of T cell responses to chimpanzee adenovirus vectors encoding HIV gag-pol-nef antigen.

    Science.gov (United States)

    Herath, S; Le Heron, A; Colloca, S; Bergin, P; Patterson, S; Weber, J; Tatoud, R; Dickson, G

    2015-12-16

    Adenoviruses have been shown to be both immunogenic and efficient at presenting HIV proteins but recent trials have suggested that they may play a role in increasing the risk of HIV acquisition. This risk may be associated with the presence of pre-existing immunity to the viral vectors. Chimpanzee adenoviruses (chAd) have low seroprevalence in human populations and so reduce this risk. ChAd3 and chAd63 were used to deliver an HIV gag, pol and nef transgene. ELISpot analysis of T cell responses in mice showed that both chAd vectors were able to induce an immune response to Gag and Pol peptides but that only the chAd3 vector induced responses to Nef peptides. Although the route of injection did not influence the magnitude of immune responses to either chAd vector, the dose of vector did. Taken together these results demonstrate that chimpanzee adenoviruses are suitable vector candidates for the delivery of HIV proteins and could be used for an HIV vaccine and furthermore the chAd3 vector produces a broader response to the HIV transgene. PMID:26546736

  10. Analysis of T cell responses to chimpanzee adenovirus vectors encoding HIV gag–pol–nef antigen

    Science.gov (United States)

    Herath, S.; Le Heron, A.; Colloca, S.; Bergin, P.; Patterson, S.; Weber, J.; Tatoud, R.; Dickson, G.

    2015-01-01

    Adenoviruses have been shown to be both immunogenic and efficient at presenting HIV proteins but recent trials have suggested that they may play a role in increasing the risk of HIV acquisition. This risk may be associated with the presence of pre-existing immunity to the viral vectors. Chimpanzee adenoviruses (chAd) have low seroprevalence in human populations and so reduce this risk. ChAd3 and chAd63 were used to deliver an HIV gag, pol and nef transgene. ELISpot analysis of T cell responses in mice showed that both chAd vectors were able to induce an immune response to Gag and Pol peptides but that only the chAd3 vector induced responses to Nef peptides. Although the route of injection did not influence the magnitude of immune responses to either chAd vector, the dose of vector did. Taken together these results demonstrate that chimpanzee adenoviruses are suitable vector candidates for the delivery of HIV proteins and could be used for an HIV vaccine and furthermore the chAd3 vector produces a broader response to the HIV transgene. PMID:26546736

  11. Nanomechanical phenotype of chondroadherin-null murine articular cartilage.

    Science.gov (United States)

    Batista, Michael A; Nia, Hadi T; Önnerfjord, Patrik; Cox, Karen A; Ortiz, Christine; Grodzinsky, Alan J; Heinegård, Dick; Han, Lin

    2014-09-01

    Chondroadherin (CHAD), a class IV small leucine rich proteoglycan/protein (SLRP), was hypothesized to play important roles in regulating chondrocyte signaling and cartilage homeostasis. However, its roles in cartilage development and function are not well understood, and no major osteoarthritis-like phenotype was found in the murine model with CHAD genetically deleted (CHAD(-/-)). In this study, we used atomic force microscopy (AFM)-based nanoindentation to quantify the effects of CHAD deletion on changes in the biomechanical function of murine cartilage. In comparison to wild-type (WT) mice, CHAD-deletion resulted in a significant ≈70-80% reduction in the indentation modulus, Eind, of the superficial zone knee cartilage of 11 weeks, 4 months and 1 year old animals. This mechanical phenotype correlates well with observed increases in the heterogeneity collagen fibril diameters in the surface zone. The results suggest that CHAD mainly plays a major role in regulating the formation of the collagen fibrillar network during the early skeletal development. In contrast, CHAD-deletion had no appreciable effects on the indentation mechanics of middle/deep zone cartilage, likely due to the dominating role of aggrecan in the middle/deep zone. The presence of significant rate dependence of the indentation stiffness in both WT and CHAD(-/-) knee cartilage suggested the importance of both fluid flow induced poroelasticity and intrinsic viscoelasticity in murine cartilage biomechanical properties. Furthermore, the marked differences in the nanomechanical behavior of WT versus CHAD(-/-) cartilage contrasted sharply with the relative absence of overt differences in histological appearance. These observations highlight the sensitivity of nanomechanical tools in evaluating structural and mechanical phenotypes in transgenic mice. PMID:24892719

  12. 76 FR 62407 - Ocean Transportation Intermediary License; Applicants

    Science.gov (United States)

    2011-10-07

    ... 30326, Officers: Chad Rosenberg, President/CEO (Qualifying Individual), Michael Shea, Secretary..., Officers: Alexandre Ayanou, Manager/President/CEO (Qualifying Individual), Faty Ayanou, Member, Application... Brodecki, Chairman, Application Type: QI Change. Crowley Logistics, Inc. (NVO & OFF), 9487 Regency...

  13. 48 CFR 52.225-23 - Required Use of American Iron, Steel, and Manufactured Goods-Buy American Act-Construction...

    Science.gov (United States)

    2010-10-01

    ..., Denmark, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary, Iceland, Ireland, Israel, Italy..., Cambodia, Central African Republic, Chad, Comoros, Democratic Republic of Congo, Djibouti, East Timor..., Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary,...

  14. 76 FR 62134 - Bureau of Consular Affairs; Registration for the Diversity Immigrant (DV-2013) Visa Program

    Science.gov (United States)

    2011-10-06

    ... written agreement recognized by a court or a court order). If you are legally separated or divorced, you... African Republic Chad Comoros Congo Congo, Democratic Republic of the Cote D'Ivoire (Ivory Coast)...

  15. Analyzing Naval Counter-Piracy Effectiveness using Simkit Discrete Event Simulation (DES) and the MMOWGLI Platform

    OpenAIRE

    Hutchins, Chad R.

    2012-01-01

    MOVES Research & Education Systems Seminar: Presentation; Session 11: Simulation Modeling for Analysis; Moderator: Arnie Buss; Evaluating Naval Counter-Piracy Effectiveness using Simkit Discrete Event Simulation and the MMOWGLI Platform; speaker: LT Chad Hutchins, USN

  16. 3 CFR - Presidential Determination With Respect to Foreign Governments' Efforts Regarding Trafficking in...

    Science.gov (United States)

    2010-01-01

    ...) of the Act, with respect to Chad, Kuwait, Malaysia, Mauritania, Niger, Papua New Guinea, Saudi Arabia... addressing of basic human needs, as defined by the Department of the Treasury with respect to other,...

  17. Using New Maps to Navigate Cancer Treatment - TCGA

    Science.gov (United States)

    Drs.Scott Hwang and Chad Holder of Emory University discuss the development of VARSARI and The Cancer Imaging Program's TCGA Radiology Initiative. Learn more about their and Dr. Carl Jaffe's work in this TCGA In Action Case Study.

  18. Effect of Polysaccharide from Spirulina (Arthrospira) platensis of Chad Lake on Immunity and Anti-tumor Activity of S180 Ascites Sarcoma Mice%非洲乍得湖钝顶螺旋藻多糖对S180腹水瘤小鼠免疫抗肿瘤作用的实验研究

    Institute of Scientific and Technical Information of China (English)

    杜玲; 扈瑞平; 穆文静; 赵飞艳; 敖长金

    2014-01-01

    采用小鼠S180腹水瘤模型,观察非洲乍得湖钝顶螺旋藻多糖不同剂量组小鼠的生存状况、瘤体外观,测定非洲乍得湖钝顶螺旋藻多糖对小鼠免疫器官指数及血清IL-2和TNF-α水平的影响,以探讨非洲乍得湖钝顶螺旋藻多糖对肿瘤的抑制作用及其对S180腹水瘤小鼠的免疫调节作用.结果表明:高、中、低三个剂量的非洲乍得湖钝顶螺旋藻多糖均能改善腹水瘤小鼠的生存状况,缩小肿瘤在体内扩散的范围;不同浓度的非洲乍得湖钝顶螺旋藻多糖组小鼠胸腺和脾脏指数均高于模型组,肝体/比均低于模型组,以中剂量组作用效果最为显著(P<0.05);不同剂量的非洲乍得湖钝顶螺旋藻多糖均显著提高小鼠血清TNF-α的水平(P<0.05),对IL-2含量的影响表现为三个剂量组的均高于模型组,且高、中剂量组的与模型组相比差异显著(P<0.05);三种剂量组之间相比,中剂量组对IL-2和TNF-α的诱生作用最明显,与高、低剂量组相比差异均显著(P<0.05).研究结果提示,非洲乍得湖钝顶螺旋藻多糖能够促进小鼠免疫器官的生长发育从而增强免疫功能,也可通过促进小鼠免疫细胞分泌TNF-α和IL-2而发挥免疫调节作用.

  19. Health and equity impacts of a large oil project in Africa

    OpenAIRE

    Jobin William

    2003-01-01

    A system of external reviewers was established by the World Bank Group to promote a thorough environmental and health impact assessment for the 3.5 billion US dollars Chad Oil Export Project, based on a loan request from Chad, Cameroon and a consortium of oil companies. The environmental and health assessment process showed evidence of its ability to minimize the number of deaths from malaria, traffic accidents and construction accidents and the occurrence of minor sexually transmitted diseas...

  20. Way that Student Party Members and Party Branch Play the Role in Good School Spirit and Study Style Construction: Based on Hector—Brent Chad's Situational Leadership Theory%学生党员、党支部在优良校风、学风建设中发挥作用的途径研究——基于赫赛—布兰查德的情境领导理论

    Institute of Scientific and Technical Information of China (English)

    李颖

    2012-01-01

    School spirit and style of study is a school's atmosphere; it is a kind of stable, distinct, and recognized behavior trend that all teaching and administrative staff and students forms for a long time in teaching and study. The paper studies the role of student party members and party branch in construction of good school spirit and study style, and discusses that student party members and party branch should take the different styles of leadership when forming good school spirit and study style according to different student group.%校风、学风,就是一所学校的风气,是指一所学校的全体教职工和学生在教学和学习过程中经过长期积累所形成的稳定的、鲜明的、被社会公众所公认的行为倾向.本文通过将组织行为学、管理学引入学生党员、党支部在优良校风、学风建设发挥作用的途径研究中,论证高校学生党员、党支部在形成和维系优良校风、学风等优秀组织文化中,应根据学生群体的不同类型采取不同的领导方式.

  1. From Afghanistan to Abeche : The Norwegian contribution to MINURCAT: applying a framework of interests and values

    OpenAIRE

    2011-01-01

    This thesis aims to shed light on the various motivational factors that affected the political decision-making processes of Norway’s contribution to the UN-led operation in Chad 2009/10 (MINURCAT). By applying a theoretical framework of interests and values, this thesis discovered a set of variables that contributed to the understanding of the two political decisions of entering and exiting Chad. The study traces the shifting discourse from the outspoken ambitions in Soria Moria to ‘increase ...

  2. 75 FR 61239 - Request for Public Comments on Annual Review of Country Eligibility for Benefits Under the...

    Science.gov (United States)

    2010-10-04

    ..., Republic of Chad, Federal Islamic Republic of Comoros, Republic of Congo, Democratic Republic of Congo..., Republic of Kenya, Kingdom of Lesotho, Republic of Liberia, Republic of Malawi, Republic of Mali, Islamic..., Republic of Cote d'Ivoire, ] Republic of Guinea, Republic of Equatorial Guinea, State of Eritrea,...

  3. Paysage Médiatique Tchadien

    Directory of Open Access Journals (Sweden)

    Moussa Djibrine Absoulaye

    2015-01-01

    Full Text Available The media gestation in Chad has been very laborious, mainly during the prior democracy period that only existed public media doing the Government politic propaganda. But since 21st century, the media plurality has been faced like the proliferation of private media forming the voice of voiceless-people. Nowadays, the media industry become a struggle way of democratic opposition party.

  4. 77 FR 33216 - Agency Information Collection Activities

    Science.gov (United States)

    2012-06-05

    ... 10235, New Executive Office Building, Washington, DC 20503 or electronically mailed to Chad_A._Lallemand... over many selections within a given occupational or organization area. No information from the form is... federal agencies only for evaluating whether an agency's recruitment activities are effectively...

  5. TTIP in the Bigger Picture

    OpenAIRE

    DAMRO, Chad

    2015-01-01

    The proposed EU-US trade agreement (TTIP) is the product of the dynamics of the global trade regime and the evolution of the transatlantic relationship, argues Chad Damro. He suggests that a successful deal would both increase EU-US interdependence and encourage competition between them, with significant implications for the global political economy.

  6. Without Speaking, Youth Enters Adult Work Scene, Copes with Autism a Day at a Time

    Science.gov (United States)

    Murphy, Patti

    2010-01-01

    This article presents the story of Chad Roberts of Canton, Georgia, who is proving himself a promising employee day by day. He works several jobs in increments of up to 90 minutes. Some days, he completes bulk mailings at a law firm. On others, he's at local restaurants stocking the wait staff stations with supplies. The community-based vocational…

  7. Who's Who and What's What? Special Education Services for Foster Care Students

    Science.gov (United States)

    Palladino, John M.

    2011-01-01

    This case describes the educational experiences of a foster care student named Chad. His foster parents and teacher notice educational deficits and express concern about gaps in the student's cumulative educational record. The principal and special education director must guide all constituents to adhere to special education mandates and at the…

  8. Recurrence plots from altimetry data of some lakes in Africa

    CERN Document Server

    Sparavigna, Amelia Carolina

    2014-01-01

    The paper shows recurrence plots obtained from time series of the level variations of four lakes in Africa (Nasser, Tana, Chad and Kainji). The data, coming from remote sensing, are provided by the United States Department of Agriculture. The recurrence plots allow a good visual comparison of the behaviours of local drainage basins.

  9. Recurrence Plots from Altimetry Data of Some Lakes in Africa

    OpenAIRE

    Sparavigna, Amelia Carolina

    2014-01-01

    The paper shows recurrence plots obtained from time series of the level variations of four lakes in Africa (Nasser, Tana, Chad and Kainji). The data, coming from remote sensing, are provided by the United States Department of Agriculture. The recurrence plots allow a good visual comparison of the behaviours of local drainage basins.

  10. The Niger River Basin : A Vision for Sustainable Management

    OpenAIRE

    Andersen, Inger; Dione, Ousmane; Jarosewich-Holder, Martha; Olivry, Jean-Claude; Golitzen, Katherin George

    2008-01-01

    The Niger River Basin Authority (NBA) brings together nine countries to promote integrated water resources management across political borders. The nine - Benin, Burkina Faso, Cameroon, Chad, Cote d'Ivoire, Guinea, Mali, Niger, and Nigeria have embraced a shared vision to build institutional capacity, political agreement, and public support for cooperation. The countries agree that sustain...

  11. The Effect of Adding Ready-to-Use Supplementary Food to a General Food Distribution on Anemia, Length, and Morbidity: A Cluster Randomized Controlled Trial

    OpenAIRE

    Dewey, Kathryn G.; Mary Arimond

    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.

  12. Phonology and Morphology of Mambay (Niger-Congo, Adamawa)

    NARCIS (Netherlands)

    Anonby, Erik John

    2008-01-01

    Mambay is an Adamawa (Niger-Congo) language spoken by 15,000 people in Chad and Cameroon. The study opens with historical and linguistic background. A phonological inventory of the language is then presented and distribution patterns are examined. Some striking phenomena include a profoundly phon

  13. Volunteer Notes on Reforestation. A Handbook for Volunteers. Appropriate Technologies for Development. Reprint R-45.

    Science.gov (United States)

    Seefeldt, Steve, Comp.

    Provided in this document are descriptions of reforestation projects and techniques presented by Peace Corps volunteers from Chad, Ivory Coast, Upper Volta, and Niger. The purpose of the document is to aid individuals in trying to find solutions to the problems facing forestry in the Sahel. These projects include: (1) reforestation of Ronier palm…

  14. 78 FR 4878 - Agency Information Collection Activities: Submission for the Office of Management and Budget (OMB...

    Science.gov (United States)

    2013-01-23

    ... collection on September 24, 2012 (77 FR 58871). 1. Type of submission, new, revision, or extension: New. 2... number: 3150-XXXX. 4. The form number if applicable: N/A. 5. How often the collection is required.... Chad Whiteman, Desk Officer, Office of Information and Regulatory Affairs (3150-XXXX),...

  15. Aspects of a Grammar of Makary Kotoko (Chadic, Cameroon)

    Science.gov (United States)

    Allison, Sean David

    2012-01-01

    Makary Kotoko (MK), a Central Chadic B language, is spoken in the north of Cameroon just south of Lake Chad. Published works on MK to date include about a dozen articles on different aspects of the grammar of the language, primarily by H. Tourneux. The present work, which is based on a substantial corpus of recorded texts, is a systematic…

  16. Comparative Assessment of Transmission-Blocking Vaccine Candidates against Plasmodium falciparum

    DEFF Research Database (Denmark)

    Kapulu, M C; Da, D F; Miura, K; Li, Y; Blagborough, A M; Churcher, T S; Nikolaeva, D; Williams, Andrew Richard; Goodman, A L; Sangare, I; Turner, A V; Cottingham, M G; Nicosia, A; Straschil, U; Tsuboi, T; Gilbert, S C; Long, Carole A; Sinden, R E; Draper, S J; Hill, A V S; Cohuet, A; Biswas, S

    2015-01-01

    candidate antigens, have been developed independently and have reported varied transmission-blocking activities (TBA). Here, recombinant chimpanzee adenovirus 63, ChAd63, and modified vaccinia virus Ankara, MVA, expressing AgAPN1, Pfs230-C, Pfs25, and Pfs48/45 were generated. Antibody responses primed...

  17. NCBI nr-aa BLAST: CBRC-OLAT-26-0164 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0164 ref|NP_776444.1| chondroadherin [Bos taurus] sp|Q27972|CHAD_BOVIN Chondroad...herin precursor (Cartilage leucine-rich protein) (38 kDa bone protein) [Contains: Chondroadherin m

  18. NCBI nr-aa BLAST: CBRC-OLAT-26-0164 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0164 ref|NP_062037.1| chondroadherin [Rattus norvegicus] sp|O70210|CHAD_RAT Chondroad...herin precursor (Cartilage leucine-rich protein) gb|AAC40060.1| chondroadherin [Rattus norveg...icus] gb|EDM05713.1| chondroadherin [Rattus norvegicus] NP_062037.1 9e-85 57% ...

  19. The Members of the Agency

    International Nuclear Information System (INIS)

    The new Member since the last list of Member States was issued (INFCIRC/2/Rev.60) is Chad, which deposited the instrument of acceptance of the Statute on 2 November 2005. The Attachment hereto shows the dates on which the present 139 Member States became Members

  20. The moral challenge of green technology / Aarne P Vesilind, Lauren Heine, Jamie Hendry

    Index Scriptorium Estoniae

    Vesilind, Aarne P

    2006-01-01

    Autorid leiavad, et rohelise tehnoloogia kasutuselevõtu ja ettevõtete kasumi teenimise vastuseisu korral võidab kasumlikkus ning reguleerimata vaba turu süsteem ei toeta jätkusuutlikku arengut. Käsitletakse ettevõtte DuPont tegevdirektori Chad Holliday otsust jätkata tulutoova toote Teflon tootmist

  1. Natural Resources Management

    OpenAIRE

    Prasad C. Mohan

    1996-01-01

    Participatory community-based Natural Resources Management (NRM) Projects have been implemented over the last 5-6 years in Benin, Burkina Faso, Mali, and Niger with the support of France, Germany, Norway, the United States, and the World Bank's International Development Association facility. Furthermore, pilot operation concentrating on specific NRM issues are underway in Chad (pastoral pe...

  2. Net clinical benefit of new oral anticoagulants (dabigatran, rivaroxaban, apixaban) versus no treatment in a 'real world' atrial fibrillation population

    DEFF Research Database (Denmark)

    Banerjee, A; Lane, D A; Torp-Pedersen, C;

    2012-01-01

    patients with non-valvular AF between 1997-2008, for dabigatran, rivaroxaban and apixaban on the basis of recent clinical trial outcome data for these new OACs. In patients with CHADS2=0 but at high bleeding risk, apixaban and dabigatran 110 mg bid had a positive net clinical benefit. At CHA2DS2-VASc=1......, apixaban and both doses of dabigatran (110 mg and 150 mg bid) had a positive net clinical benefit. In patients with CHADS2 score=1 or CHA2DS2-VASc=2, the three new OACs (dabigatran, rivaroxaban and apixaban) appear superior to warfarin for net clinical benefit, regardless of risk of bleeding. When risk of...... in AF. Using 'real world' data, our modelling analysis has shown that when the risk of bleeding and stroke are both high, all three new drugs appear to have a greater net clinical benefit compared to warfarin....

  3. Clinical significance of serum hypersensitive C-reactive protein (CRP) and macrophage colony-stimulating factor (M-CSF) levels in patients with coronary heart disease

    International Nuclear Information System (INIS)

    Objective: To investigate the significance of determination of serum contents, of hs-CRP and M-CSF in patients with coronary heart disease (Chad). Methods: Serum hs-CRP contents were determined with immuno-turbidity and M-CSF contents were determined with RIA in 71 patients with Chad (35 Sap, 21 Up, 15 Amid) and 35 controls. Results: Serum levels of hs -CRP and M-CSF in CAD patients were significantly higher than those in controls (P0.05). Conclusion: The serum levels of hs-CRP and M-CSF were related to development of CAD, but no relationship existed between the levels and coronary artery calibers. (authors)

  4. Detection of antibodies specific to Campylobacter fetus subsp. venerealis in the vaginal mucus of Nigerian breeding cows

    Directory of Open Access Journals (Sweden)

    Zerai Woldehiwet

    2010-09-01

    Full Text Available The presence of bovine venereal campylobacteriosis in the Lake Chad Basin of Nigeria was investigated using an enzyme-linked immunosorbent assay (ELISA for the detection of IgA antibodies specific to Campylobacter fetus subsp. venerealis in vaginal mucus (n = 66. IgA antibodies specific to C. fetus subsp. venerealis were detected in 7 (11% vaginal mucus samples. All but one of the IgA-positive samples originated from cows belonging to herds with a history of abortion and infertility which suggested an association between antibody detection and poor herd fertility. It was concluded that bovine venereal campylobacteriosis is prevalent in the Lake Chad Basin of Nigeria and its contribution to reduced reproductive performance in cattle herds may be grossly underestimated in this part of the world.

  5. Petroleum

    International Nuclear Information System (INIS)

    Here are gathered the results of the year 1999 concerning the petroleum industry in France ('UFIP' data), the market quotations of crude oil, the prices of fuels in France and in Portugal and some news about the petroleum industry in Algeria (privatization, exploration-offshore, repurchase), in Iraq (exports, contracts with foreign companies), in Russian Federation (petroleum pipelines and oil ports constructions) and in Chad (production sharing, offshore sites discoveries). (O.M.)

  6. Ressources alimentaires non conventionnelles

    OpenAIRE

    Malaisse, F.

    2004-01-01

    Unconventional Food Resources. Concepts of ethnobotany, ethnozoology and ethnoecology are defined and their respective development recounted. The geographic frame is afterwards specified: Tropical Africa. Diversity of wild edible vegetable products is illustrated by some examples: cyanobacteria from Chad, mushroom consumption in the Zambezian region and pteridophagy. Upper plants are approached according to six ensembles, namely starchy fruits and seeds, oilseeds and nuts, fleshy fruits, rese...

  7. EVALUATION OF SCORPION STING INCIDENCE IN ALKUFRA CITY DURING 1993 AND 1994

    OpenAIRE

    2013-01-01

    Libya is almost desert or semi-desert. Scorpion fauna is widely diversity in the country. However, scorpion in many places are not medical important especially around the coastal area. Meanwhile, scorpion species in desert are almost accounted as a first health problem related to animal toxin. Scorpion stings are ancient hazards. Alkufra is small city in east south of Libya in boarders with Egypt, Sudan and Chad. The most common scorpion genuses in Alkufra city are Leiurus sp, Androctonus sp....

  8. Lakes, groundwater and palaeohydrology in the Sahel of NE Nigeria : evidence from hydrogeochemistry

    OpenAIRE

    W. M. Edmunds; Fellman, E.; Goni, I.B.

    1999-01-01

    The geochemistry of natural waters from rain, soil, the unsaturated zone, shallow aquifers, lakes and the stratified aquifer system of the Chad Basin sediments has been investigated to interpret modern hydrological processes and to reconstruct the palaeohydrology of NE Nigeria, a type region of the southern Sahel. Recharge to the confined Middle and Lower aquifers, recorded in NE Nigeria, occurred between 24 and 18.6 ka BP, prior to the last glacial maximum. The mean annual temperature at thi...

  9. mtDNA of Fulani Nomads and Their Genetic Relationships to Neighboring Sedentary Populations

    Czech Academy of Sciences Publication Activity Database

    Černý, Viktor; Hájek, Martin; Bromová, Markéta; Čmejla, R.; Diallo, I.; Brdička, R.

    2006-01-01

    Roč. 78, č. 1 (2006), s. 9-27. ISSN 0018-7143 R&D Projects: GA ČR(CZ) GA404/03/0318 Institutional research plan: CEZ:AV0Z80020508 Keywords : mtDNA variation * HVS-I * Fulani nomads * sub-Saharan populations * Chad * Cameroon * Burkina Faso Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 1.132, year: 2006

  10. Screening for atrial fibrillation with baseline and intermittent ECG recording in an out-of-hospital population

    OpenAIRE

    Hendrikx, Tijn; Hörnsten, Rolf; Rosenqvist, Mårten; Sandström, Herbert

    2013-01-01

    BACKGROUND: the objective of this study is to investigate the detection rate of undiagnosed atrial fibrillation (AF) with short intermittent ECG recordings during four weeks among out-of-hospital patients, having at least one additional risk factor (CHADS2) for stroke. METHOD: Design: Cross-sectional study. Setting: Eight family practice centres and two hospital-based out-patient clinics in Sweden. Subjects: 989 out-of-hospital patients, without known AF, having one or more risk factors assoc...

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

    OpenAIRE

    Sulaiman S Ibrahim; 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 couple...

  12. L'expérience tchadienne des personnes déplacées, réinstallées dans les ouadis de la région du Ouaddaï Géographique (Nord-Est du Tchad

    Directory of Open Access Journals (Sweden)

    Sondjo, M.

    1985-01-01

    Full Text Available The Chadian experience of displaced people, resettled in the wadis of the geographical Ouaddai region (North-East Chad. Though climatic and other factors have reduced wildlife's role in the life of Sereer villagers, hunting for food is still practised, especially by younger peuple. Thanks to a field study, this activity is examined and its future envisaged in the context of rural development.

  13. RESTAURATION DES TERRES DEGRADEES DE LA LISIERE DU PARC DE MANDA (TCHAD) ET DEVELOPPEMENT LOCAL DES PRATIQUES ET DES REALITES SOCIO-SPATIALES CONTRASTEES

    OpenAIRE

    Ouya, Bondoro

    2010-01-01

    This paper will discuss the important issues concerning natural resource conservation and the socio-economic development of the periphery of the Manda park, in southwest Chad. In the face of climactic irregularities, the problem of conservation and use and natural resources is confronted with several issues. During the past two decades, several production models have been tested, including: the application of successive levels of chemical fertilizer, compost, and oil cakes following each cult...

  14. Stroke and Death Prediction with the Impact of Vascular Disease in Patients with Atrial Fibrillation

    OpenAIRE

    Abhishek Maan, MD; Amir Y. Shaikh, MD; Moussa Mansour, MD; Jeremy N. Ruskin, MD; E. Kevin Heist, MD, PhD

    2012-01-01

    Atrial fibrillation (AF) is the most common arrhythmia encountered in the U.S. and the growing burden of AF has profound health implications due to the association of AF with an increased risk of stroke, heart failure, and mortality. AF is a significant risk factor for thromboembolic stroke; and also independently increases total mortality in patients with and without cardiovascular disease. Various risk stratification schemes such as CHADS2 and CHA2DS2-VASc have been implemented in clinical ...

  15. Crocodiles in the Sahara Desert: An Update of Distribution, Habitats and Population Status for Conservation Planning in Mauritania

    OpenAIRE

    Brito, José C.; Martínez-Freiría, Fernando; Sierra, Pablo; Sillero, Neftalí; Tarroso, Pedro

    2011-01-01

    Background Relict populations of Crocodylus niloticus persist in Chad, Egypt and Mauritania. Although crocodiles were widespread throughout the Sahara until the early 20th century, increased aridity combined with human persecution led to local extinction. Knowledge on distribution, occupied habitats, population size and prey availability is scarce in most populations. This study evaluates the status of Saharan crocodiles and provides new data for Mauritania to assist conservation planning. Me...

  16. A Viral Vectored Prime-Boost Immunization Regime Targeting the Malaria Pfs25 Antigen Induces Transmission-Blocking Activity

    OpenAIRE

    Goodman, Anna L.; Blagborough, Andrew M.; Sumi Biswas; Yimin Wu; Hill, Adrian V.; Sinden, Robert E.; Draper, Simon J

    2011-01-01

    The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63), human adenovirus serotype 5 (AdHu5) and modified vaccinia virus Ankara (MVA) viral vectored vaccines. Two immunizations were administered to mice in a ...

  17. Eating Anxiety: The Perils of Food Politics

    OpenAIRE

    Lavin, Chad

    2015-01-01

    In Eating Anxiety, Chad Lavin argues that our culture's obsession with diet, obesity, meat, and local foods enacts ideological and biopolitical responses to perceived threats to both individual and national sovereignty. Using the occasion of eating to examine assumptions about identity, objectivity, and sovereignty that underwrite so much political order, Lavin explains how food functions to help structure popular and philosophical understandings of the world and the place of humans within it...

  18. Predicting Stress Related to Basic Needs and Safety in Darfur Refugee Camps: A Structural and Social Ecological Analysis

    OpenAIRE

    Rasmussen, Andrew; Annan, Jeannie

    2009-01-01

    The research on the determinants of mental health among refugees has been largely limited to traumatic events, but recent work has indicated that the daily hassles of living in refugee camps also play a large role. Using hierarchical linear modelling to account for refugees nested within camp blocks, this exploratory study attempted to model stress surrounding safety and acquiring basic needs and functional impairment among refugees from Darfur living in Chad, using individual-level demograph...

  19. Simulation of Daily Snapshot Rhythm Monitoring to Identify Atrial Fibrillation in Continuously Monitored Patients with Stroke Risk Factors.

    Directory of Open Access Journals (Sweden)

    Yuichiro Yano

    Full Text Available New technologies are diffusing into medical practice swiftly. Hand-held devices such as smartphones can record short-duration (e.g., 1-minute ECGs, but their effectiveness in identifying patients with paroxysmal atrial fibrillation (AF is unknown.We used data from the TRENDS study, which included 370 patients (mean age 71 years, 71% men, CHADS2 score≥1 point: mean 2.3 points who had no documentation of atrial tachycardia (AT/AF or antiarrhythmic or anticoagulant drug use at baseline. All were subsequently newly diagnosed with AT/AF by a cardiac implantable electronic device (CIED over one year of follow-up. Using a computer simulation approach (5,000 repetitions, we estimated the detection rate for paroxysmal AT/AF via daily snapshot ECG monitoring over various periods, with the probability of detection equal to the percent AT/AF burden on each day.The estimated AT/AF detection rates with snapshot monitoring periods of 14, 28, 56, 112, and 365 days were 10%, 15%, 21%, 28%, and 50% respectively. The detection rate over 365 days of monitoring was higher in those with CHADS2 scores ≥2 than in those with CHADS2 scores of 1 (53% vs. 38%, and was higher in those with AT/AF burden ≥0.044 hours/day compared to those with AT/AF burden <0.044 hours/day (91% vs. 14%; both P<0.05.Daily snapshot ECG monitoring over 365 days detects half of patients who developed AT/AF as detected by CIED, and shorter intervals of monitoring detected fewer AT/AF patients. The detection rate was associated with individual CHADS2 score and AT/AF burden.ClinicalTrials.gov NCT00279981.

  20. Do physiological measures predict selected CrossFit® benchmark performance?

    OpenAIRE

    Butcher, Scotty

    2015-01-01

    Scotty J Butcher,1,2 Tyler J Neyedly,3 Karla J Horvey,1 Chad R Benko2,41Physical Therapy, University of Saskatchewan, 2BOSS Strength Institute, 3Physiology, University of Saskatchewan, 4Synergy Strength and Conditioning, Saskatoon, SK, CanadaPurpose: CrossFit® is a new but extremely popular method of exercise training and competition that involves constantly varied functional movements performed at high intensity. Despite the popularity of this training method, the physiological deter...

  1. Do physiological measures predict selected CrossFit® benchmark performance?

    OpenAIRE

    Butcher SJ; Neyedly TJ; Horvey KJ; Benko CR

    2015-01-01

    Scotty J Butcher,1,2 Tyler J Neyedly,3 Karla J Horvey,1 Chad R Benko2,41Physical Therapy, University of Saskatchewan, 2BOSS Strength Institute, 3Physiology, University of Saskatchewan, 4Synergy Strength and Conditioning, Saskatoon, SK, CanadaPurpose: CrossFit® is a new but extremely popular method of exercise training and competition that involves constantly varied functional movements performed at high intensity. Despite the popularity of this training method, the physiological determina...

  2. Transmission dynamics and economics of rabies control in dogs and humans in an African city

    OpenAIRE

    Zinsstag, J.; Dürr, S.; Penny, M.A.; Mindekem, R.; Roth, F.; Gonzalez, S. Menendez; Naissengar, S.; Hattendorf, J.

    2009-01-01

    Human rabies in developing countries can be prevented through interventions directed at dogs. Potential cost-savings for the public health sector of interventions aimed at animal-host reservoirs should be assessed. Available deterministic models of rabies transmission between dogs were extended to include dog-to-human rabies transmission. Model parameters were fitted to routine weekly rabid-dog and exposed-human cases reported in N′Djaména, the capital of Chad. The estimated transmission rate...

  3. Success?: ESDP military conflict management operations: 2003-2009

    OpenAIRE

    Rodt, Annemarie Peen

    2009-01-01

    From 2003 to 2009, the EU launched five military conflict management operations within the framework of the European Security and Defence Policy. This thesis examines their success. To this end, the thesis develops a definition and a set of criteria for success. It applies this theoretical framework in an empirical case study of success in the five EU operations, which were undertaken in Macedonia, Bosnia and Herzegovina, the Democratic Republic of Congo, Chad and the Central African Republic...

  4. COOPERATION OR CONFLICT? IDENTITY AND SCARCE RESOURCES OF PREHISTORIC SAHARAN PASTORALISTS

    OpenAIRE

    Lenssen-Erz, Tilman

    2015-01-01

    Nomadic or transhumant pastoralists in the Ennedi Highlands in north easternChad have always had to cope with scarce resources. When the region was first made use of bypastoralists circa 3000 BC, aridification had already started. Despite progressing aridification, the landscape was used for herding cattle and goats, and later also for keeping horses and camelsin the following millennia. Hundreds of rock art sites are witness to this appropriation.While demographic data are still missing, it ...

  5. Essays on food security in sub-Saharan Africa : The role of food prices and climate shocks

    OpenAIRE

    Brunelin, Stéphanie

    2014-01-01

    This doctoral thesis is in line with the renewed interest in research on agriculture and food security, following the 2008 global food crisis. The aim of this thesis is to contribute to a better understanding of the complex issues surrounding food security. The first chapter investigates whether the changes in the international price of rice are transmitted to the domestic prices of rice in Senegal, Mali and Chad. Results indicate that the domestic prices of imported rice in Dakar and of loca...

  6. Essais sur la sécurité alimentaire en Afrique sub-saharienne : le rôle des prix des denrées alimentaires et des chocs climatiques

    OpenAIRE

    Brunelin, Stéphanie

    2014-01-01

    This doctoral thesis is in line with the renewed interest in research on agriculture and food security, following the 2008 global food crisis. The aim of this thesis is to contribute to a better understanding of the complex issues surrounding food security. The first chapter investigates whether the changes in the international price of rice are transmitted to the domestic prices of rice in Senegal, Mali and Chad. Results indicate that the domestic prices of imported rice in Dakar and of loca...

  7. NCBI nr-aa BLAST: CBRC-OLAT-26-0164 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0164 ref|NP_001258.2| chondroadherin precursor [Homo sapiens] sp|O15335|CHAD_HUMAN Chondroad...herin precursor (Cartilage leucine-rich protein) gb|AAK51556.1|AF371328_1 chondroadher...in [Homo sapiens] gb|AAH36360.1| Chondroadherin [Homo sapiens] gb|AAH73974.1| Chondroadherin [Homo sapiens] gb|EAW94613.1| chondroad

  8. Milnacipran for the management of fibromyalgia syndrome

    OpenAIRE

    Boomershine, Chad

    2010-01-01

    Michelle J Ormseth, Anne E Eyler, Cara L Hammonds, Chad S BoomershineDivision of Rheumatology and Immunology, Vanderbilt University, Nashville, TN, USAAbstract: Fibromyalgia syndrome (FMS) is a widespread pain condition associated with fatigue, cognitive dysfunction, sleep disturbance, depression, anxiety, and stiffness. Milnacipran is one of three medications currently approved by the Food and Drug Administration in the United States for the management of adult FMS patients. This review is t...

  9. Pregabalin for the management of fibromyalgia syndrome

    OpenAIRE

    Boomershine, Chad

    2010-01-01

    Chad S BoomershineDepartment of Medicine, Vanderbilt University, Nashville, TN, USAAbstract: This last article in a three-part series on approved medications for managing fibromyalgia syndrome (FMS) reviews pregabalin (Lyrica®). Pregabalin was the first drug approved for FMS management and, as an anticonvulsant, differs from the other approved agents that are antidepressants. Pregabalin inhibits presynaptic excitatory neurotransmitter release by blocking a2d calcium channels....

  10. Duloxetine in the management of diabetic peripheral neuropathic pain

    OpenAIRE

    Boomershine, Chad

    2011-01-01

    Michelle J Ormseth, Beth A Sholz, Chad S BoomershineDivision of Rheumatology and Immunology, Vanderbilt University, Nashville, TN, USAAbstract: Diabetic neuropathy affects up to 70% of diabetics, and diabetic peripheral neuropathic pain (DPNP) is the most common and debilitating of the diabetic neuropathies. DPNP significantly reduces quality of life and increases management costs in affected patients. Despite the impact of DPNP, management is poor with one-quarter of patients receiving no tr...

  11. Duloxetine for the management of fibromyalgia syndrome

    OpenAIRE

    Boomershine, Chad

    2009-01-01

    Beth A Scholz, Cara L Hammonds, Chad S BoomershineDepartment of Medicine, Vanderbilt University, Nashville, TN, USAAbstract: Fibromyalgia syndrome (FMS) is a widespread pain condition associated with a wide range of additional symptoms including fatigue, insomnia, depression, anxiety and stiffness. Duloxetine is one of three medications currently FDA approved for use in FMS management. Duloxetine is a mixed serotonin and norepinephrine reuptake inhibitor (SNRI) that functions by increasing ce...

  12. Regional view of a Trans-African Drainage System

    OpenAIRE

    Mohamed Abdelkareem; Farouk El-Baz

    2014-01-01

    Despite the arid to hyperarid climate of the Great Sahara of North Africa, pluvial climates dominated the region. Radar data shed some light on the postulated Trans-African Drainage System and its relationship to active and inactive tributaries of the Nile basin. Interpretations of recent elevation data confirm a source of the river water from the Red Sea highlands did not connect the Atlantic Ocean across Tushka basin, highlands of Uwinate and Darfur, and Chad basin, but northward to the anc...

  13. The role of THRIVE score in prediction of outcomes of acute ischemic stroke patients with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    尤寿江

    2014-01-01

    Objective To study whether the total health risks in vascular events(THRIVE)score could predict the prognosis in the acute ischemic stroke patients with atrial fibrillation.Methods A total of 169 patients were enrolled in the study,with NIH Stroke Scale(NIHSS)score,THRIVE score and CHADS2score given to each patients at admission and modified Rankin Scale(mRS)given at3 months follow up.All patients were divided into the

  14. An evidence-based review of edoxaban and its role in stroke prevention in patients with nonvalvular atrial fibrillation

    OpenAIRE

    Acharya T; Deedwania P

    2015-01-01

    Tushar Acharya, Prakash Deedwania Division of Cardiology, Department of Internal Medicine, University of California, San Francisco, Fresno, CA, USA Abstract: Atrial fibrillation is the most common arrhythmia in the elderly. It is responsible for significant morbidity and mortality from cardioembolic complications like stroke. As a result, atrial fibrillation patients are risk-stratified using the CHADS2 or CHA2DS2-VASc scoring systems. Those at intermediate-to-high risk have traditionally be...

  15. Community Influences on Married Men's Uptake of HIV Testing in Eight African Countries

    OpenAIRE

    Stephenson, Rob; Elfstrom, K. Miriam; Winter, Amy

    2013-01-01

    Despite efforts to increase HIV testing in the African region, the proportion of men who report ever having been tested for HIV remains low. Research has focused on individual level determinants of women's testing however little is known about factors associated with men's testing behavior. This analysis investigates community influences on HIV testing among men ages 15–54, using Demographic and Health Survey (DHS) data from Chad, Ghana, Malawi, Nigeria, Tanzania, Uganda, Zambia, and Zimbabwe...

  16. Earth observations during Space Shuttle flight STS-41 - Discovery's mission to planet earth

    Science.gov (United States)

    Lulla, Kamlesh P.; Helfert, Michael R.; Amsbury, David L.; Whitehead, Victor S.; Richards, Richard N.; Cabana, Robert D.; Shepherd, William M.; Akers, Thomas D.; Melnick, Bruce E.

    1991-01-01

    An overview of space flight STS-41 is presented, including personal observations and comments by the mission astronauts. The crew deployed the Ulysses spacecraft to study the polar regions of the sun and the interplanetary space above the poles. Environmental observations, including those of Lake Turkana, Lake Chad, biomass burning in Madagascar and Argentina, and circular features in Yucatan are described. Observations that include landforms and geology, continental sedimentation, desert landscapes, and river morphology are discussed.

  17. Photovoltaic power in less developed countries

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.V.

    1977-03-24

    The potential of solar photovoltaic power in the third world (less developed countries) is analyzed. Application of irrigation systems powered by photovoltaics in Bangladesh, Chad, India, and Pakistan, plus an economic analysis of a photovoltaic-powered village in northern India indicate solar energy is competitive with the least-cost fossil-fuel alternatives. The most cost-effective method for specific geographical locations can be determined by field testing based on the case history data reported.

  18. Radiative heating rates profiles associated with a springtime case of Bodélé and Sudan dust transport over West Africa

    OpenAIRE

    C. Lema^itre; C. Flamant; Cuesta, J.; J.-C. Raut; Chazette, P.; P. Formenti; Pelon, J

    2010-01-01

    The radiative heating rate due to mineral dust over West Africa is investigated using the radiative code STREAMER, as well as remote sensing and in situ observations gathered during the African Monsoon Multidisciplinary Analysis Special Observing Period (AMMA SOP). We focus on two days (13 and 14 June 2006) of an intense and long lasting episode of dust being lifted in remote sources in Chad and Sudan and transported across West Africa in the African easterly jet region, during which airborne...

  19. Radiative forcing associated with a springtime case of Bodélé and Sudan dust transport over West Africa

    OpenAIRE

    Lemaître, C; C. Flamant; Cuesta, J.; J.-C. Raut; Chazette, P.; P. Formenti; Pelon, J

    2010-01-01

    The radiative forcing due to mineral dust over West Africa is investigated using the radiative code STREAMER, as well as remote sensing and in situ observations gathered during the African Monsoon Multidisciplinary Analysis Special Observing Period (AMMA SOP). We focus on two days (13 and 14 June 2006) of an intense and long-lasting episode of dust being lifted in remote sources in Chad and Sudan and transported across West Africa in the African easterly jet region, during which airborne oper...

  20. Stroke Risk Predictor Scoring Systems in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Tze-Fan Chao, M.D; Shih-Ann Chen, M.D.

    2014-02-01

    Full Text Available An effective risk stratification which could help us identify high-risk patients who should take oral anticoagulants (OACs is the key step for stroke prevention in atrial fibrillation (AF. Several scoring systems were available to estimate the risk of stroke in AF, including CHADS2, CHA2DS2-VASc, R2CHADS2 and ATRIA scores, which were constituted of different clinical risk factors. Recently, several new OACs (NOACs were demonstrated to be at least as effective as warfarin in stroke prevention and were much safer regarding the risk of intra-cranial hemorrhage. In the era of NOACs, the roles of scoring schemes have shifted to identify patinets with a truly low-risk of thromboembolic events, in whom OACs were not recommended. The CHA2DS2-VASc score is powerful in selecting “truly low-risk” patients who are not necessary to receive anticoagulation therapies. Whether the new-emerging scoring systems, R2CHADS2 and ATRIA scores, could further improve the stroke prediction in AF deserves a further study.

  1. Combining viral vectored and protein-in-adjuvant vaccines against the blood-stage malaria antigen AMA1: report on a phase 1a clinical trial.

    Science.gov (United States)

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel Gw; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-12-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines--chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising "mixed-modality" regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible. PMID:25156127

  2. : Emergency Physician Patterns Related to Anticoagulation of Patients with Recent-Onset Atrial Fibrillation and Flutter

    Directory of Open Access Journals (Sweden)

    Paraish Misra, MD

    2013-04-01

    Full Text Available Guidelines strongly recommend long-term anticoagulation with warfarin for patients with newly recognized AF who have high embolic risk by virtue of a CHADS2 (Congestive Heart Failure, Hypertension, Age >65, Diabetes, History of Stroke score ≥ 2. The goal of this study was to determine patterns of emergency department-initiated anticoagulation among eligible patients discharged from Canadian centers with an episode of recent-onset atrial fibrillation and flutter (RAFF and determine if decision-making is driven by the CHADS2 score or other factors. This was accomplished by examining health records using uniform case identification and data abstraction as well as centralized quality control; it was conducted in 8 Canadian university emergency departments over a 12-month period. Eligible patients for this analysis demonstrated RAFF requiring emergency management, were not already taking warfarin and were not admitted to hospital. Univariate analyses were conducted using T-test or Chi-square to select factors associated with anticoagulation initiation at a significance level of p < 0.15 and multiple logistic regression was employed to evaluate independent predictors after adjustment for confounders. Among 633 eligible patients, only 21 out of 120 patients (18% with a CHADS2 score ≥ 2 received anticoagulation and among 70 patients who were given anticoagulation only 21 (30% had a CHADS2 score ≥ 2. Independent predictors of anticoagulation included age by 10-year strata: (OR = 1.7; 95% CI 1.3 – 2.1, heparin use in the anticoagulation (OR = 9.6; 95% CI 4.9 – 18.9, a new prescription for metoprolol (OR = 9.6; 95% CI 4.9 – 18.9 and being referred to cardiology for follow-up (OR = 5.6; 95% CI 2.6 – 12.0. CHADS2 ≥ 2 doubled the likelihood of being prescribed anticoagulation (OR= 2.0; 95% CI 1.5 – 3.5 but was not an independent predictor. It was thus determined that patients discharged from the emergency department in this study were not

  3. Composite risk scores and composite endpoints in the risk prediction of outcomes in anticoagulated patients with atrial fibrillation. The Loire Valley Atrial Fibrillation Project.

    Science.gov (United States)

    Banerjee, A; Fauchier, L; Bernard-Brunet, A; Clementy, N; Lip, G Y H

    2014-03-01

    Several validated risk stratification schemes for prediction of ischaemic stroke (IS)/thromboembolism (TE) and major bleeding are available for patients with non-valvular atrial fibrillation (NVAF). On the basis for multiple common risk factors for IS/TE and bleeding, it has been suggested that composite risk prediction scores may be more practical and user-friendly than separate scores for bleeding and IS/TE. In a long-term prospective hospital registry of anticoagulated patients with newly diagnosed AF, we compared the predictive value of existing risk prediction scores as well as composite risk scores, and also compared these risk scoring systems using composite endpoints. Endpoint 1 was the simple composite of IS and major bleeds. Endpoint 2 was based on a composite of IS plus intracerebral haemorrhage (ICH). Endpoint 3 was based on weighted coefficients for IS/TE and ICH. Endpoint 4 was a composite of stroke, cardiovascular death, TE and major bleeding. The incremental predictive value of these scores over CHADS2 (as reference) for composite endpoints was assessed using c-statistic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Of 8,962 eligible individuals, 3,607 (40.2%) had NVAF and were on OAC at baseline. There were no statistically significant differences between the c-statistics of the various risk scores, compared with the CHADS2 score, regardless of the endpoint. For the various risk scores and various endpoints, NRI and IDI did not show significant improvement (≥1%), compared with the CHADS2 score. In conclusion, composite risk scores did not significantly improve risk prediction of endpoints in patients with NVAF, regardless of how endpoints were defined. This would support individualised prediction of IS/TE and bleeding separately using different separate risk prediction tools, and not the use of composite scores or endpoints for everyday 'real world' clinical practice, to guide decisions on

  4. Underutilization of Warfarin Therapy in Elderly Patients with Atrial Fibrillation – Fear or False Sense of Security!

    Directory of Open Access Journals (Sweden)

    Mazda Biria MD

    2008-09-01

    Full Text Available Background: Under utilization of warfarin in elderly patients with atrial fibrillation (AF has been recognized as a significant health care issue. This study examines the rate and reasons for warfarin underutilization in elderly patients with AF at the Kansas City Veterans Affairs Medical Center. Methods: Retrospective study reviewing electronic medical records of all patients aged 65 and older with the diagnosis of atrial fibrillation. Patients on warfarin were excluded. Reasons for not using warfarin were extracted by reviewing the electronic medical record. Anticoagulation indications for these patients were determined based on the ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation. Results: Warfarin was not used by 407 patients (25% with known AF. Average age was 79+6.2 years. 60% of patients had persistent or permanent AF. Prevalence of risk factors for thromboembolism included hypertension (74%, heart failure or ejection fraction of <40% (21%, diabetes (27% and coronary artery disease (48%. CHADS (2 scores were documented in the charts less than 1% of the times. Only 11 patients had CHADS (2 score of 0 and 70 had a score of 1. A class I or IIa indication for warfarin therapy was present in 298 (73% of patients. Return to sinus rhythm (37% was the most common reason for not using warfarin. In 30% of cases the reason not to use warfarin was not addressed. Other reasons not to use warfarin included fear of falls (7%, prior head or GI bleed (14%, patient refusal & noncompliance (12%. History of CVA or TIA was documented in 12% of patients. Conclusions: Underutilization of warfarin in elderly patients with atrial fibrillation remains a common problem despite their high risk for thromboembolic events. A false sense of security about the paroxysmal nature of AF, lack of proper insight about stroke risk (CHADS (2, and fear of bleeding are the most common reasons for non use of warfarin.

  5. Pteridophyta collected in Northern Nigeria and Northern Cameroon

    Directory of Open Access Journals (Sweden)

    Jan kornaś

    2014-02-01

    Full Text Available 25 species of Pteridophyta were collected in Northern Nigeria (mainly the Lake Chad Basin and the Mandara Mts. and in the neighbouring parts of Cameroon. 11 of them have not been recorded previously from this area: Isoetes schweinfurthii A. Br. in Bak., Selaginella tenerrima A. Br. ex Kuhn, Ophioglossum gomenzianum Welw. ex A. Br., Marsilea coromandeliana Willd., M. distorta A. Br., M. nubica A. Br., M. subterranea Lepr. ex A. Br., Azolla africana Desv., Ceratopteris richardii Brogn., Adiantum capillus-veneris Linn., and Actiniopleris semiflabellata Pic. Ser.

  6. Characterizing the Manga Aquifer to Ensure Safe Drinking Water in South-east Niger

    International Nuclear Information System (INIS)

    Niger is the largest nation in West Africa (with 1.26 million km2), located between the Sahara and sub- Saharan regions without coast line. The majority of the country is covered by desert. Low precipitation (151 mm per year in 2009, World Bank 2010) and recurring droughts have made groundwater an essential water source. In the Diffa region (ca. 150 000 km2), located in south-eastern Niger and in the north-west of Lake Chad, groundwater is an important water source for the local population, together with surface water from Lake Chad and less importantly from the Komadougou Yobe River. A decreasing trend in rainfall, and hence shrinking of the area around Lake Chad, and irrigation development proposed by Nigerian authorities to meet growing food demand have led to actual and potential increases in groundwater exploitation. Moreover, water from Lake Chad has high salt content, limiting its usage. Groundwater resources in the region are found in several aquifer systems: (a) the Manga Quaternary aquifer covering nearly the entire Diffa region at 20 m to more than 50 m depth, except in a central part of the region (less than 10 m depth); (b) the alluvial aquifer located in the Komadougou valley and in topographic depressions of the region at a shallow depth (less than 10 m); (c) the Pliocene aquifer in the Pliocene sands and silts, covering the entire region at about 300 m depth in most of the region or at about 200 m in the central part; (d) the Continental Intercalary/Hamadien aquifer, covering the entire region at 40 to 60 m depth with a very low or zero recharge rate. To improve groundwater resource use and management of the potable water supply in the Diffa region, Technical Cooperation project NER8011 was conducted from 2009- 2012 to characterize the Manga Quaternary aquifer system. The project was entitled Studying the Recharge Process and the Status of Mineral Deposits Within the Manga Aquifer (Diffa region). The project was implemented by le Ministere de L

  7. App Empire Make Money, Have a Life, and Let Technology Work for You

    CERN Document Server

    Mureta, Chad

    2012-01-01

    A guide to building wealth by designing, creating, and marketing a successful app across any platform Chad Mureta has made millions starting and running his own successful app business, and now he explains how you can do it, too, in this non-technical, easy-to-follow guide. App Empire provides the confidence and the tools necessary for taking the next step towards financial success and freedom. The book caters to many platforms including iPhone, iPad, Android, and BlackBerry. This book includes real-world examples to inspire those who are looking to cash in on the App gold rush. Learn how to s

  8. Relating Optical Properties of Dusts to their Mineralogical and Physical Interrelationships

    Science.gov (United States)

    Engelbrecht, J. P.; Moosmuller, H.; Jayanty, R. K. M.; Casuccio, G.; Pincock, S. L.

    2015-12-01

    The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The 38 μm, health (medical geology), ocean fertilization, and damage to equipment.

  9. Mapping and deterring violent extremist networks in North-West Africa

    DEFF Research Database (Denmark)

    Walther, Olivier; Leuprecht, Christian

    in the Islamic Maghreb (AQIM) is unquestionably the most connected VEO, which in purely network terms can be seen as a liability. Spatial analysis shows that, while violence was almost exclusively concentrated within Algeria between 1997 and 2004, cross-border movements intensified in the mid-2000s following...... the establishment of military bases by AQIM in Mali. As of late, VEOs have primarily concentrated their operations in Northern Mali as well as Southern Algeria, whereas Mauritania, Niger and Chad have been relatively unaffected. It follows that deterrence and containment strategies should be devised for regions...

  10. THE ESTIMATION OF THE HERBACEOUS BIOMASS IN THE SAHELIANS PASTORAL ZONES USING A GIS

    OpenAIRE

    TIZIANA, DE FILIPPIS; Djaby, Bakary; BRAHIMA, KONE; Patrizio, Vignaroli; ANDREA, DI VECCHIA

    2001-01-01

    In the Sahel region the pastorals resources are strongly linked to the fluctuation of the biomass production and as well as the breeding systems, which are based on the transhumance and the nomadism as well. In the present study, an integrated approach of multi-source, multi-type and multi-scales data analysis in the pastoral zone in Senegal, Mali, Burkina Faso, Mauritania, Niger and Chad has been developed using PC-Arc/Info and Arc/View potentialities for the purpose of Sahelian rangela...

  11. Dietary algae and HIV/AIDS: proof of concept clinical data

    OpenAIRE

    Teas, J.; Irhimeh, M R

    2011-01-01

    Dietary algae have been reported to decrease HIV viral fusion/entry and replication and increase immune response, suggesting that regular consumption of algae by people in Japan, Korea, and Chad could be an important factor in their relatively low HIV/AIDS rates. Five antiretroviral-naïve people with HIV (three females, two males; five African Americans) living in Columbia SC participated in the phase I study of acute toxicity. Subjects were randomly assigned to 5 g day-1 brown seaweed (Undar...

  12. TESTING NONLINEAR INFLATION CONVERGENCE FOR THE CENTRAL AFRICAN ECONOMIC AND MONETARY COMMUNITY

    Directory of Open Access Journals (Sweden)

    Emmanuel Anoruo

    2014-01-01

    Full Text Available This paper uses nonlinear unit root testing procedures to examine the issue of inflation convergence for the Central African Economic and Monetary Community (CEMAC member states including Cameron, Central African Republic, Chad, Equatorial Guinea, Gabon and the Republic of Congo. The results from nonlinear STAR unit root tests suggest that inflation differentials for the sample countries are nonlinear and mean reverting processes. These results provide evidence of inflation convergence among countries within CEMAC. The finding of inflation convergence indicates the feasibility of a common monetary policy and/or inflation targeting regime within CEMAC.

  13. Acidente Vascular Cerebral Cardioembólico : fibrilhação auricular e terapêutica antitrombótica

    OpenAIRE

    Reis, Lígia Silva

    2011-01-01

    Introdução: O Acidente Vascular Cerebral constitui a primeira causa de morte em Portugal. A fibrilhação auricular apresenta-se como um factor de alto risco cardioembólico, aumentando 5 vezes o risco de AVC. O CHADS2 score estima o risco de ocorrência de AVC em pacientes com fibrilhação auricular, assim como permite decidir sobre a aplicabilidade de terapêutica anticoagulante ou antiagregante. O HAS-BLED score avalia o risco de sangramento nos pacientes com fibrilhação auricular que estão sob ...

  14. Enhancing immunogenicity and transmission-blocking activity of malaria vaccines by fusing Pfs25 to IMX313 multimerization technology.

    OpenAIRE

    Yuanyuan Li; Leneghan, Darren B.; Kazutoyo Miura; Daria Nikolaeva; Iona J. Brian; Dicks, Matthew D. J.; Fyfe, Alex J.; Zakutansky, Sarah E.; Simone de Cassan; Long, Carole A.; Draper, Simon J; Hill, Adrian V. S.; Fergal Hill; Sumi Biswas

    2016-01-01

    Transmission-blocking vaccines (TBV) target the sexual-stages of the malaria parasite in the mosquito midgut and are widely considered to be an essential tool for malaria elimination. High-titer functional antibodies are required against target antigens to achieve effective transmission-blocking activity. We have fused Pfs25, the leading malaria TBV candidate antigen to IMX313, a molecular adjuvant and expressed it both in ChAd63 and MVA viral vectors and as a secreted protein-nanoparticle. P...

  15. 'Real-world' management and outcomes of patients with paroxysmal vs. non-paroxysmal atrial fibrillation in Europe

    DEFF Research Database (Denmark)

    Boriani, Giuseppe; Laroche, Cecile; Diemberger, Igor;

    2016-01-01

    -morbidities, as well as lower CHADS2, CHA2DS2-VASc, and HAS-BLED scores. Patients with first-detected AF (29.9%) had characteristics similar to persistent AF patients (25.9%), but lower use of oral anticoagulants. Patients with permanent AF represented 17.4% of the cohort. At 1 year, the rate of stroke...... during follow-up. Independent predictors of death were age, chronic heart failure, chronic kidney disease, diabetes, restrictive cardiomyopathy, and physical activity. CONCLUSION: In this 'real-world' contemporary observational registry, patients with non-paroxysmal AF had a worse outcome, in terms of...

  16. Easy Travel

    Institute of Scientific and Technical Information of China (English)

    Francois; Essomba

    2011-01-01

    A common visa for six Central African countries boosts tourism FOR a region that is made up of six countries, the Economic and Monetary Community of Central Africa(CEMAC) has less than 2 million annual cross border arrivals according to official statistics. Cameroon,the Republic of the Congo, Gabon,Equatorial Guinea,Central African Republic(CAR) and Chad make up this group,whose regional travel statistics are extremely low by international standards.Cameroon received only 580,000 visitors in 2010.

  17. Earth observations during Space Shuttle flight STS-26: Discovery's mission to earth - September 29-October 3, 1988

    Science.gov (United States)

    Wood, C. A.; Helfert, M. R.; Lulla, K. P.; Covey, R. O.

    1989-01-01

    During the late September-early October, 1988 flight of the Space Shuttle Discovery, astronauts took 1505 photographs of earth using handheld cameras. The resulting pictures provide an overview, not available from any other source, of dynamic environmental phenomena on five continents. The Discovery photographs show that: (1) atmospheric clarity has improved in the Northern Hemisphere, (2) widespread burning of natural vegetation throughout the Southern Hemisphere continues to generate immense smoke palls and extensive sedimentation in rivers and estuaries, and (3) although the drought in Africa was partially relieved by heavy rains in autumn, 1988, Lakes Chad and Nasser are at the lowest levels ever seen from space.

  18. Contribution to the analytical study of the pollutants (particularly heavy metals) in waters of the Chari river crossing the town of N’Djamena

    OpenAIRE

    Ngaram, Nambatingar

    2011-01-01

    No physicochemical major study of water of the Chari river was carried out in spite of the fact that since the independence of Chad (1960), some food agro factories, hospitals, textile factories, slaughter-houses… were installed on its banks. Also, this work aims to the “contribution to the analytical study of the pollutants (particularly heavy metals) in waters of the Chari river crossing the town of N’Djamena” using the suitable chemical techniques. The results of the analyses obtains after...

  19. Manuscript Cultures

    DEFF Research Database (Denmark)

    the University of Copenhagen for a workshop on manuscripts to compare notes. This event led to the publication of this volume, which brings together16 articles on philological, cultural, and material aspects of manuscripts in search for a common ground across disciplines and cultures.......What do Mesoamerica, Greece, Byzantium, Island, Chad, Ethiopia, India, Tibet, China and Japan have in common? Like many other cultures of the world, they share a particular form of cultural heritage: ancient handwritten documents. In 2007, scholars from some20 countries around the world gathered at...

  20. Uso tradicional y actual de spirulina sp. (Arthrospira sp.)

    OpenAIRE

    Liliana Ramírez- Moreno; Roxana Olvera-Ramírez

    2006-01-01

    Spirulina sp. (Arthrospira sp.) es una cianobacteria filamentosa no diferenciada, habitante de lagos alcalinos, que se cultiva para consumo humano debido a su contenido nutricional. En México, el consumo de esta cianobacteria se remonta a tiempos prehispánicos, cuando era conocida como tecuitlatl, siendo conocida como dihé por las tribus nativas de la región del lago de Chad, en África. En los últimos años se le han atribuido diversos efectos positivos en el tratamiento de algunos tipos de al...

  1. Simulation of Daily Snapshot Rhythm Monitoring to Identify Atrial Fibrillation in Continuously Monitored Patients with Stroke Risk Factors

    OpenAIRE

    Yano, Yuichiro; Greenland, Philip; Lloyd-Jones, Donald M.; Daoud, Emile G.; Koehler, Jodi L.; Ziegler, Paul D.

    2016-01-01

    Background New technologies are diffusing into medical practice swiftly. Hand-held devices such as smartphones can record short-duration (e.g., 1-minute) ECGs, but their effectiveness in identifying patients with paroxysmal atrial fibrillation (AF) is unknown. Methods We used data from the TRENDS study, which included 370 patients (mean age 71 years, 71% men, CHADS2 score≥1 point: mean 2.3 points) who had no documentation of atrial tachycardia (AT)/AF or antiarrhythmic or anticoagulant drug u...

  2. How to cheat in After Effects

    CERN Document Server

    Perkins, Chad

    2013-01-01

    Get the most from the most widely used application in the postproduction field! Gain the insider tips you need to compose eye-catching, imaginative Adobe After Effects projects quickly and effectively. In How to Cheat in After Effects, Second Edition seasoned AE expert Chad Perkins provides dozens of concise, step-by-step tutorials and lavish 4-color illustrations to get you on the fast track to producing amazing motion graphics and visual effects. Updated for CS6, this new edition has been revised to include:A brand new chapter on the most popular

  3. Marginalia no. 36

    OpenAIRE

    Merrill-Cazier Library, Utah State University

    2015-01-01

    That Voila Moment …wonders of digital access in the library…… Brad Cole, Interim Dean New & Notable Acquisitions: Newton’s Opticks and four plays from Shakespeare’s second folio… Brad Cole You are an alchemist: Sir Isaac Newton’s obsession with the ancient art ….. K.schockmel Chad Nielsen wins 2014 Arrington Lecture Award ….. Patrick Williams Friends Lecture 2015: The Curious Case of the Connection between Sherlock Holmes & the Mormons … Patrick Williams 2014 Arrington Lecture Dre...

  4. NCBI nr-aa BLAST: CBRC-OLAT-26-0164 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0164 ref|NP_031715.1| chondroadherin [Mus musculus] sp|O55226|CHAD_MOUSE Chondroad...herin precursor (Cartilage leucine-rich protein) gb|AAC39963.1| chondroadherin [Mus musculus] gb|AAH12672.1| Chondroad...herin [Mus musculus] emb|CAI25589.1| chondroadherin [Mus musculus] dbj|BAE34451.1| unn...amed protein product [Mus musculus] gb|EDL15934.1| chondroadherin [Mus musculus] NP_031715.1 5e-85 57% ...

  5. Validation of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Jonas Bjerring; Lip, Gregory Y H; Hansen, Morten Lock;

    2011-01-01

    Objectives To evaluate the individual risk factors composing the CHADS2 (Congestive heart failure, Hypertension, Age=75 years, Diabetes, previous Stroke) score and the CHA2DS2-VASc (CHA2DS2-Vascular disease, Age 65-74 years, Sex category) score and to calculate the capability of the schemes to...... predict thromboembolism. Design Registry based cohort study. Setting Nationwide data on patients admitted to hospital with atrial fibrillation. Population All patients with atrial fibrillation not treated with vitamin K antagonists in Denmark in the period 1997- 2006. Main outcome measures Stroke and...

  6. Could Some Geriatric Characteristics Hinder the Prescription of Anticoagulants in Atrial Fibrillation in the Elderly?

    Directory of Open Access Journals (Sweden)

    Paule Denoël

    2014-01-01

    Full Text Available Several studies have reported underprescription of anticoagulants in atrial fibrillation (AF. We conducted an observational study on 142 out of a total of 995 consecutive ≥75 years old patients presenting AF (14% when admitted in an emergency unit of a general hospital, in search of geriatric characteristics that might be associated with the underprescription of anticoagulation therapy (mostly antivitamin K at the time of the study. The following data was collected from patients presenting AF: medical history including treatment and comorbidities, CHADS2 score, ISAR scale (frailty, Lawton’s scale (ADL, GDS scale (mood status, MUST (nutrition, and blood analysis (INR, kidney function, and albumin. Among those patients for who anticoagulation treatment was recommended (73%, only 61% were treated with it. In the group with anticoagulation therapy, the following characteristics were observed more often than in the group without such therapy: a recent (≤6 months hospitalization and medical treatment including digoxin or based on >3 different drugs. Neither the value of the CHADS2 score, nor the geriatric characteristics could be correlated with the presence or the absence of an anticoagulation therapy. More research is thus required to identify and clarify the relative importance of patient-, physician-, and health care system-related hurdles for the prescription of oral anticoagulation therapy in older patients with AF.

  7. Isoenzymes and soluble protein in Arthrospira from alkaline lakes in Erdos Plateau, China and in exotic species

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The authors compared isoenzymes of five enzymes and soluble protein in Arthrospira platensis (A3) and A. erdosensis (A4) from alkaline lakes in Erdos Plateau, Nei Monggo (Inner Mongalia),China and exotic species ofA. platensis (A1) from Chad and A. maxima (A2) from Mexico by means of polyacrylamide gel electrophoresis. The results showed that the isoenzymes of EST, POD and soluble protein were polymorphic. Monomorphism and polymorphism were found in isoenzymes of AMY, CAT and SOD, and monomorphism was found only in the introduced species. The isoenzymes and soluble protein of the local species are all polymorphic. The number of bands in these species were in the order of A3>A4>A1 >A2. A2 is the most primary, A1 from Chad Lake is relatively primary, A3 and A4 are advanced species in evolution. Cluster analysis showed that the relation between the two introduced species are the closest to each other, and so too are the two local ones.

  8. Enhanced vaccine-induced CD8+ T cell responses to malaria antigen ME-TRAP by fusion to MHC class ii invariant chain.

    Directory of Open Access Journals (Sweden)

    Alexandra J Spencer

    Full Text Available The orthodox role of the invariant chain (CD74; Ii is in antigen presentation to CD4+ T cells, but enhanced CD8+ T cells responses have been reported after vaccination with vectored viral vaccines encoding a fusion of Ii to the antigen of interest. In this study we assessed whether fusion of the malarial antigen, ME-TRAP, to Ii could increase the vaccine-induced CD8+ T cell response. Following single or heterologous prime-boost vaccination of mice with a recombinant chimpanzee adenovirus vector, ChAd63, or recombinant modified vaccinia virus Ankara (MVA, higher frequencies of antigen-specific CD4+ and CD8+ T cells were observed, with the largest increases observed following a ChAd63-MVA heterologous prime-boost regimen. Studies in non-human primates confirmed the ability of Ii-fusion to augment the T cell response, where a 4-fold increase was maintained up to 11 weeks after the MVA boost. Of the numerous different approaches explored to increase vectored vaccine induced immunogenicity over the years, fusion to the invariant chain showed a consistent enhancement in CD8+ T cell responses across different animal species and may therefore find application in the development of vaccines against human malaria and other diseases where high levels of cell-mediated immunity are required.

  9. Association of Left Atrial Fibrosis Detected by Delayed Enhancement Magnetic Resonance Imaging and Risk of Stroke in Patients with Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Dana C. Peters

    2011-07-01

    Full Text Available This is a review of a recent paper by Daccarett et al1 investigating LA remodeling, as assessed by magnetic resonance imaging (MRI, as a risk factor for stroke. A major motivation for treatment of atrial fibrillation (AF is to reduce the risk of stroke, which often arises from emboli formed in the static left atrium (LA. Risk stratification for stroke in AF patients, important because it determines the use of anti-coagulants in patients, is clinically performed using the validated CHADS2 score (based on prior stroke, diabetes, hypertension, advanced age, and congestive heart-failure. However, because of its limited predictive power, patients with low, moderate and high risk CHADS2 scores are often prescribed anti-coagulants in equal frequencies.2 There is growing evidence that the burden of AF (i.e. the amount of time that patient remains in AF rhythm may be a predictor of stroke,3 since during this time emboli can form in the LA appendage.

  10. Dimerization interface of 3-hydroxyacyl-CoA dehydrogenase tunes the formation of its catalytic intermediate.

    Directory of Open Access Journals (Sweden)

    Yingzhi Xu

    Full Text Available 3-Hydroxyacyl-CoA dehydrogenase (HAD, EC 1.1.1.35 is a homodimeric enzyme localized in the mitochondrial matrix, which catalyzes the third step in fatty acid β-oxidation. The crystal structures of human HAD and subsequent complexes with cofactor/substrate enabled better understanding of HAD catalytic mechanism. However, numerous human diseases were found related to mutations at HAD dimerization interface that is away from the catalytic pocket. The role of HAD dimerization in its catalytic activity needs to be elucidated. Here, we solved the crystal structure of Caenorhabditis elegans HAD (cHAD that is highly conserved to human HAD. Even though the cHAD mutants (R204A, Y209A and R204A/Y209A with attenuated interactions on the dimerization interface still maintain a dimerization form, their enzymatic activities significantly decrease compared to that of the wild type. Such reduced activities are in consistency with the reduced ratios of the catalytic intermediate formation. Further molecular dynamics simulations results reveal that the alteration of the dimerization interface will increase the fluctuation of a distal region (a.a. 60-80 that plays an important role in the substrate binding. The increased fluctuation decreases the stability of the catalytic intermediate formation, and therefore the enzymatic activity is attenuated. Our study reveals the molecular mechanism about the essential role of the HAD dimerization interface in its catalytic activity via allosteric effects.

  11. Risk of Ischemic Stroke and Stroke Prevention in Patients with Atrial Fibrillation and Renal Dysfunction

    Directory of Open Access Journals (Sweden)

    Tze-Fan Chao; Shih-Ann Chen

    2015-06-01

    Full Text Available Atrial fibrillation (AF is the most common sustained cardiac arrhythmia and its prevalence is projected to continuously increase over the next few decades.1 AF patients usually have several important comorbidities, such as hypertension, diabetes and heart failure, and “lone AF” is becoming uncommon.2 The incidence of AF significantly increased when patients have more systemic diseases. In the previous study from Taiwan, the risk of new-onset AF increased from 0.77 per 1000 person-years for patients with a CHADS2 (congestive heart failure, hypertension, age ≥75, diabetes mellitus, and prior stroke or transient ischemic attack score of 0 to 34.6 per 1000 person-years for those with a score of 6.3 AF is an important risk factor of ischemic stroke with a worse prognosis and higher recurrence rate compared to that of non-AF related stroke.4 The risk of AF-related stroke is not homogenous and mainly depends on the presence or absence of clinical risk factors. Several scoring systems, including CHADS2 and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65–74, female schemes,5-6 which incorporated clinical important factors have been developed to estimate the risk of stroke and guide anti-thrombotic therapies for AF patients.

  12. Geochemical variations in aeolian mineral particles from the Sahara-Sahel Dust Corridor.

    Science.gov (United States)

    Moreno, Teresa; Querol, Xavier; Castillo, Sonia; Alastuey, Andrés; Cuevas, Emilio; Herrmann, Ludger; Mounkaila, Mohammed; Elvira, Josep; Gibbons, Wes

    2006-10-01

    The Sahara-Sahel Dust Corridor runs from Chad to Mauritania and expels huge amounts of mineral aerosols into the Atlantic Ocean. Data on samples collected from Algeria, Chad, Niger, and Western Sahara illustrate how corridor dust mineralogy and chemistry relate to geological source and weathering/transport history. Dusts sourced directly from igneous and metamorphic massifs are geochemically immature, retaining soluble cations (e.g., K, Na, Rb, Sr) and accessory minerals containing HFSE (e.g., Zr, Hf, U, Th) and REE. In contrast, silicate dust chemistry in desert basins (e.g., Bodélé Depression) is influenced by a longer history of transport, physical winnowing (e.g., loss of Zr, Hf, Th), chemical leaching (e.g., loss of Na, K, Rb), and mixing with intrabasinal materials such as diatoms and evaporitic salts. Mineral aerosols blown along the corridor by the winter Harmattan winds mix these basinal and basement materials. Dusts blown into the corridor from sub-Saharan Africa during the summer monsoon source from deeply chemically weathered terrains and are therefore likely to be more kaolinitic and stripped of mobile elements (e.g., Na, K, Mg, Ca, LILE), but retain immobile and resistant elements (e.g., Zr, Hf, REE). Finally, dusts blown southwestwards into the corridor from along the Atlantic Coastal Basin will be enriched in carbonate from Mesozoic-Cenozoic marine limestones, depleted in Th, Nb, and Ta, and locally contaminated by uranium-bearing phosphate deposits. PMID:16600327

  13. Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pannala, S; D' Azevedo, E; Zacharia, T

    2002-02-26

    The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of

  14. Quantifying Modern Recharge to the Nubian Sandstone Aquifer System: Inferences from GRACE and Land Surface Models

    Science.gov (United States)

    Mohamed, A.; Sultan, M.; Ahmed, M.; Yan, E.

    2014-12-01

    The Nubian Sandstone Aquifer System (NSAS) is shared by Egypt, Libya, Chad and Sudanand is one of the largest (area: ~ 2 × 106 km2) groundwater systems in the world. Despite its importance to the population of these countries, major hydrological parameters such as modern recharge and extraction rates remain poorly investigated given: (1) the large extent of the NSAS, (2) the absence of comprehensive monitoring networks, (3) the general inaccessibility of many of the NSAS regions, (4) difficulties in collecting background information, largely included in unpublished governmental reports, and (5) limited local funding to support the construction of monitoring networks and/or collection of field and background datasets. Data from monthly Gravity Recovery and Climate Experiment (GRACE) gravity solutions were processed (Gaussian smoothed: 100 km; rescaled) and used to quantify the modern recharge to the NSAS during the period from January 2003 to December 2012. To isolate the groundwater component in GRACE data, the soil moisture and river channel storages were removed using the outputs from the most recent Community Land Model version 4.5 (CLM4.5). GRACE-derived recharge calculations were performed over the southern NSAS outcrops (area: 835 × 103 km2) in Sudan and Chad that receive average annual precipitation of 65 km3 (77.5 mm). GRACE-derived recharge rates were estimated at 2.79 ± 0.98 km3/yr (3.34 ± 1.17 mm/yr). If we take into account the total annual extraction rates (~ 0.4 km3; CEDARE, 2002) from Chad and Sudan the average annual recharge rate for the NSAS could reach up to ~ 3.20 ± 1.18 km3/yr (3.84 ± 1.42 mm/yr). Our recharge rates estimates are similar to those calculated using (1) groundwater flow modelling in the Central Sudan Rift Basins (4-8 mm/yr; Abdalla, 2008), (2) WaterGAP global scale groundwater recharge model (< 5 mm/yr, Döll and Fiedler, 2008), and (3) chloride tracer in Sudan (3.05 mm/yr; Edmunds et al. 1988). Given the available global

  15. Consistency of safety and efficacy of new oral anticoagulants across subgroups of patients with atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Lega

    Full Text Available AIMS: The well-known limitations of vitamin K antagonists (VKA led to development of new oral anticoagulants (NOAC in non-valvular atrial fibrillation (NVAF. The aim of this meta-analysis was to determine the consistency of treatment effects of NOAC irrespective of age, comorbidities, or prior VKA exposure. METHODS AND RESULTS: All randomized, controlled phase III trials comparing NOAC to VKA up to October 2012 were eligible provided their results (stroke/systemic embolism (SSE and major bleeding (MB were reported according to age (≤ or >75 years, renal function, CHADS2 score, presence of diabetes mellitus or heart failure, prior VKA use or previous cerebrovascular events. Interactions were considered significant at p <0.05. Three studies (50,578 patients were included, respectively evaluating apixaban, rivaroxaban, and dabigatran versus warfarin. A trend towards interaction with heart failure (p = 0.08 was observed with respect to SSE reduction, this being greater in patients not presenting heart failure (RR = 0.76 [0.67-0.86] than in those with heart failure (RR = 0.90 [0.78-1.04]; Significant interaction (p = 0.01 with CHADS2 score was observed, NOAC achieving a greater reduction in bleeding risk in patients with a score of 0-1 (RR 0.67 CI 0.57-0.79 than in those with a score ≥2 (RR 0.85 CI 0.74-0.98. Comparison of MB in patients with (RR 0.97 CI 0.79-1.18 and without (RR 0.76 CI 0.65-0.88 diabetes mellitus showed a similar trend (p = 0.06. No other interactions were found. All subgroups derived benefit from NOA in terms of SSE or MB reduction. CONCLUSIONS: NOAC appeared to be more effective and safer than VKA in reducing SSE or MB irrespective of patient comorbidities. Thromboembolism risk, evaluated by CHADS2 score and, to a lesser extent, diabetes mellitus modified the treatment effects of NOAC without complete loss of benefit with respect to MB reduction.

  16. An overview of the geology and major ore deposits of Central Africa: Explanatory note for the 1:4,000,000 map “Geology and major ore deposits of Central Africa”

    Science.gov (United States)

    Milesi, J. P.; Toteu, S. F.; Deschamps, Y.; Feybesse, J. L.; Lerouge, C.; Cocherie, A.; Penaye, J.; Tchameni, R.; Moloto-A-Kenguemba, G.; Kampunzu, H. A. B.; Nicol, N.; Duguey, E.; Leistel, J. M.; Saint-Martin, M.; Ralay, F.; Heinry, C.; Bouchot, V.; Doumnang Mbaigane, J. C.; Kanda Kula, V.; Chene, F.; Monthel, J.; Boutin, P.; Cailteux, J.

    2006-04-01

    This paper is prepared within the frameworks of IGCP Project 470 and the associated BRGM scientific project "Africa 1999-2004" to accompany the 1:4,000,000 scale map "Geology and major ore deposits of Central Africa, presented at the 20th Colloquium of African Geology in Orleans in June 2004. It incorporates geological and metallogenic data from eight countries in Central Africa (Angola, Cameroon, Chad, Central African Republic, Congo Brazzaville, Democratic Republic of Congo (DRC), Equatorial Guinea and Zambia). The map is a harmonised and geo-referenced preliminary map, based on a GIS at 1:2,000,000 scale, and focusses on the spatial and temporal distribution of selected major deposits.

  17. Bilateral occipital lobe infarction with altitudinal field loss following radiofrequency cardiac catheter ablation

    Directory of Open Access Journals (Sweden)

    Chen Celia S

    2010-03-01

    Full Text Available Abstract Background Bilateral stroke following radiofrequency catheter ablation is an unusual complication and may result in bilateral altitudinal visual field defects. Bilateral altitudinal visual field defects usually result from prechiasmal pathology causing damage to both retinas or optic nerves and rarely from bilateral symmetric damage to the post chiasmal visual pathways. Case presentation A 48-year-old man complained of visual disturbance on wakening following radiofrequency catheter ablation. The patient had a CHADS score of 1 pre-operatively and no complications were noted intra-operatively. Examination revealed a bilateral superior altitudinal defect and MRI of the brain showed multifocal areas of infarction predominantly involving the occipital lobes which correlated to with the visual deficits. Conclusion While the risk of thromboembolism and perioperative stroke during radiofrequency catheter ablation is small, it is not insignificant.

  18. Evolution of rainfall in the Sahel

    International Nuclear Information System (INIS)

    In this note, a number of main meteorological stations has been chosen to analyse the rainfall during the last 30 years in the Sahel (1961 to 1990). Reliable climatological data have been used for this study. The concerned area is limited by the 200 mm isohyet in the north and 600 mm isohyet in the south in the Sahel countries (Senegal, Mauritania, Mali, Burkina Faso, Niger and Chad). The evolution of rainfall has pointed out some similar and significant aspects for all stations studied. Established criteria have been used to characterize the annual rainfall and to determine the years with good rainfall and years of drought in the Sahel. (author). 6 refs, 3 figs

  19. The first true deserticolous species of Buthus Leach, 1815 from Algeria (Scorpiones: Buthidae); Ecological and biogeographic considerations.

    Science.gov (United States)

    Sadine, Salah Eddine; Bissati, Samia; Lourenço, Wilson R

    2016-01-01

    Since the early 2000s, the genus Buthus Leach, 1815 (family Buthidae) has been the subject of an important number of studies. These concerned particularly the species belonging to the 'Buthus occitanus' complex. A number of populations previously considered as subspecies or varieties of B. occitanus Leach were raised to the rank of species, but also many new species have been described. Most of the species considered in these studies come from North Africa, in particular from Morocco, Mauritania, Chad, Sudan and Egypt, but only two new species were recorded from Algeria. At present, one more new species of Buthus is described from the Algerian Saharan Desert, raising the number of confirmed Buthus in Algeria to five. Since most Buthus species from North Africa, and in particular those from Algeria, inhabit more mesic environments than the Saharan Central compartment, the new species appears as the first true deserticolous species found in this country. PMID:26632450

  20. Creating games mechanics, content, and technology

    CERN Document Server

    McGuire , Morgan

    2008-01-01

    Williams College Professor Morgan McGuire takes his games very seriously. So seriously, in fact, that he has written a book about it. ... While teaching his game design class, McGuire couldn't find a book that covered this, so he called up his colleague Professor Chad Jenkins at Brown, and they co-wrote the book to help other people design games. It combines scientific theories about rule systems with more practical advice about the process of designing a game.       -- L452The Berkshire Eagle , November 2008Apply Game Design as a Science for Public Policy to Rescue Economy, Planet: They are a

  1. Ressources alimentaires non conventionnelles

    Directory of Open Access Journals (Sweden)

    Malaisse, F.

    2004-01-01

    Full Text Available Unconventional Food Resources. Concepts of ethnobotany, ethnozoology and ethnoecology are defined and their respective development recounted. The geographic frame is afterwards specified: Tropical Africa. Diversity of wild edible vegetable products is illustrated by some examples: cyanobacteria from Chad, mushroom consumption in the Zambezian region and pteridophagy. Upper plants are approached according to six ensembles, namely starchy fruits and seeds, oilseeds and nuts, fleshy fruits, reserve organs, flowers and vegetable species. After recalling the diversity of insects eating at world scale, four orders are briefly presented: coleoptera, isoptera (termites, lepidoptera (mainly caterpillars or campeophagy and orthoptera. Finally the nutritional input of unconventional foods is underlined as well as the urgent need of their further studies.

  2. 低温对钝顶螺旋藻质膜H+-ATP酶活性的影响%EFFECT OF LOW TEMPERATURE STRESS ON THE ACTIVITIES OF PM H+-ATPASE IN SPIRULINA(ARTHROSPIRA) PLATENSIS

    Institute of Scientific and Technical Information of China (English)

    张三润; 杨茜

    2015-01-01

    Objective:To explore the variation of PM H+-ATPase of the Spirulina platensis ( S1 ) from alkaline lake in Erdos Plateau and its relationship with low temperature resistance under low tem-peratures stress,and comparing them with that of S. platensis( S2 ) from Chad Lake in Africa at the same time. Methods:After the purification of the plasma membranes of both Spirulina platensis ( S1 ) from alkaline lake in Erdos Plateau and S. platensis( S2 ) from Chad Lake in Africa with aqueous polymer two-phase partitioning system, the activities of PM H+-ATPase are determined by Mo-Blue-color method. Results:It is discovered that they being exposed right to low temperature or after exercised under low temperature,as temperature dropping and days lasting,the activities of PM H+-ATPase of both S1 and S2 rise first,and drop afterward. The stability of PM H+-ATPase activity of S1 is better than that of S2 at the same conditions above. The activity of PM H+-ATPase can be improved through low temperature exercise. The altering range of PM H+-ATPase activities is S1Chad 湖钝顶螺旋藻( S2)进行比较。方法:以鄂尔多斯钝顶螺旋藻( S1)和非洲Chad 湖钝顶螺旋藻( S2)为材料,采用两相法提纯质膜( plasms membrae PM),钼蓝法测定PM H+-ATPase活性。结果:结果显示:低温直接处理和锻炼后低温处理,S1和S2 PM H+-ATPase活性都是先升后降。 S1 PM H+-ATPase活性比S2 PM H+-ATPase活性稳定。低温锻炼可提高PM H+-ATPase活性。 PM H+-ATPase活性变化范围S1

  3. Origin of Harmattan dust settled in Northern Ghana – Long transported or local dust?

    DEFF Research Database (Denmark)

    Lyngsie, Gry; Awadzi, Theodore W; Breuning-Madsen, Henrik

    The Harmattan is a dry, dust-laden continental wind which has its origin in the Bodélé Depression in the Chad basin. In Ghana the Harmattan can be experienced from November to March, when the Harmattan replaces the dominant south westerly maritime Monsoon wind. The hypothesis of this study is that...... the majority of dust deposited in northern Ghana may not be from the original Harmattan source in the Bodélé Depression. The aim of this study is therefore to investigate the origin of deposited dust in Tamale, Ghana. This is examined by comparing wind data, grain size distribution, mineralogical and...... geochemical data from dust samples deposited during the Harmattan and Monsoon seasons, and topsoil. This study shows that despite a clear difference between the wind directions in the Harmattan and Monsoon seasons in Tamale, northern Ghana, no distinct differences are observed between the mineral or elemental...

  4. 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.

  5. Elasticity of Substitution and Antidumping Measures

    DEFF Research Database (Denmark)

    Drud Hansen, Jørgen; Meinen, Philipp; Nielsen, Jørgen Ulff-Møller

    Abstract This paper analyzes the role of the elasticity of substitution for anti-dumping decisions across countries. In monopolistic competition models with cost heterogeneous firms across countries, price differences vary inversely with the elasticity of substitution. Anti-dumping duties should...... therefore also vary inversely with the elasticity of substitution at least for countries which have a strong focus on prices in the determination of their anti-dumping measures. We test this for ten countries from 1990 to 2009 using data on anti-dumping from Chad Bown (2010) and US-data at 8-digit level...... in our empirical investigation support the predicted role of the elasticity of substitution as we find a significant negative relation between the elasticity of substitution and the final anti-dumping duties for the ‘lesser duty rule’ group of countries. The countries which do not follow the ‘lesser duty...

  6. Stratospheric water vapour budget and convection overshooting the tropopause: modelling study from SCOUT-AMMA

    Directory of Open Access Journals (Sweden)

    X. M. Liu

    2010-09-01

    Full Text Available The aim of this paper is to study the impacts of overshooting convection at a local scale on the water distribution in the tropical UTLS. Overshooting convection is assumed to be one of the processes controlling the entry of water vapour mixing ratio in the stratosphere by injecting ice crystals above the tropopause which later sublimate and hydrate the lower stratosphere. For this purpose, we quantify the individual impact of two cases of overshooting convection in Africa observed during SCOUT-AMMA: the case of 4 August 2006 over Southern Chad which is likely to have influenced the water vapour measurements by micro-SDLA and FLASH-B from Niamey on 5 August, and the case of a mesoscale convective system over Aïr on 5 August 2006. We make use of high resolution (down to 1 km horizontally nested grid simulations with the three-dimensional regional atmospheric model BRAMS (Brazilian Regional Atmospheric Modelling System. In both cases, BRAMS succeeds in simulating the main features of the convective activity, as well as overshooting convection, though the exact position and time of the overshoots indicated by MSG brightness temperature difference is not fully reproduced (typically 1° displacement in latitude compared with the overshoots indicated by brightness temperature difference from satellite observations for both cases, and several hours shift for the Aïr case on 5 August 2006. Total water budgets associated with these two events show a significant injection of ice particles above the tropopause with maximum values of about 3.7 ton s−1 for the Chad case (4 August and 1.4 ton s−1 for the Aïr case (5 August, and a total upward cross tropopause transport of about 3300 ton h−1 for the Chad case and 2400 ton h−1 for the Aïr case in the third domain of simulation. The order of magnitude of these modelled fluxes is lower but comparable with similar studies in other tropical areas based on

  7. Africa's contribution to putting an end to nuclear explosions

    International Nuclear Information System (INIS)

    African States play an important role in worldwide efforts towards nuclear non-proliferation and disarmament. All 53 African States are parties to the Nuclear Non-Proliferation Treaty (NPT), which aims at preventing the spread of nuclear weapons and weapons technology, advancing nuclear disarmament, and facilitating the peaceful uses of nuclear energy. Of Africa's 53 States, 51 have signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and 38 have also ratified it as of September 2010. Mauritius and Somalia are the only two States still to sign the Treaty. The States that have signed but not yet ratified are: Angola, Chad, Comoros, Congo, Egypt, Equatorial Guinea, Gambia, Ghana, Guinea, Guinea-Bissau, Sao Tome and Principe, Swaziland and Zimbabwe. Egypt's ratification is of particular importance as it is one of those States whose ratification is required for the Treaty's entry into force.

  8. Modeling Combinations of Pre-erythrocytic Plasmodium falciparum Malaria Vaccines.

    Science.gov (United States)

    Walker, Andrew S; Lourenço, José; Hill, Adrian V S; Gupta, Sunetra

    2015-12-01

    Despite substantial progress in the control of Plasmodium falciparum infection due to the widespread deployment of insecticide-treated bed nets and artemisinin combination therapies, malaria remains a prolific killer, with over half a million deaths estimated to have occurred in 2013 alone. Recent evidence of the development of resistance to treatments in both parasites and their mosquito vectors has underscored the need for a vaccine. Here, we use a mathematical model of the within-host dynamics of P. falciparum infection, fit to data from controlled human malaria infection clinical trials, to predict the efficacy of co-administering the two most promising subunit vaccines, RTS,S/AS01 and ChAd63-MVA ME-TRAP. We conclude that currently available technologies could be combined to induce very high levels of sterile efficacy, even in immune-naive individuals. PMID:26503278

  9. Norms, self-interest and effectiveness: explaining double standards in EU reactions to violations of democratic principles in Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Del Biondo, Karen

    2012-12-01

    Full Text Available We found historical and security interests play a role in explaining double standards, while commercial interests do not. The influence of historical interests is surprising, given that many African countries broke away from their former colonizers, while the interest of the latter in ex-colonies has diminished. However, historical interests still seem to play strongly in some former French colonies, including Chad and Ivory Coast. Historical interests can lead to a stronger or weaker preference for sanctions: in Ivory Coast, France was the main driver behind the sanctions imposed on President Gbagbo after he refused to cede power to Raila Odinga following the November 2010 elections. This should be seen in the light of the deterioration of relations between Gbagbo and France in the preceding years. A similar pattern can be observed in Zimbabwe, where tense relations over land reform resulted in the UK’s insistence on strong sanctions in 2002. By way of contrast, earlier intentions by the EU to impose sanctions on Ivory Coast as a reaction to violations of democratic principles were blocked by the French, who hoped to improve relations with President Gbagbo during the first years of his rule. Equally, in Chad, sanctions were `off the table´ because of the close relations between President Déby and France. Commercial interests, on the other hand, were not a good predictor for EU’s preference for positive or negative measures. This could be due to the fact that commercial interests were of limited importance in most cases. Furthermore, when commercial interests were important, for example in Nigeria and Niger, they did not conflict with democracy promotion. In Nigeria, EU’s preference for positive measures even ran counter to its commercial interests as Presidents Obasanjo and Jonathan were increasingly displaying nationalistic policies. In Niger, a new exploitation contract had been granted to France, but this did not prevent the EU from

  10. YouTube称盈利将近

    Institute of Scientific and Technical Information of China (English)

    刘佳

    2009-01-01

    近日,YouTube CEO查德·赫利(Chad Hurley)发表博客文章称,该网站目前每天视频浏览量超10亿次,并将很快实现盈利。今年4月份曾有美国博客分析指出,YouTube每天给谷歌带来亏损150万美元。赫利表示,随着带宽的改善,YouTube的视频质量也随之提高,而用户对更长、甚至是完整内容的需求,意味着YouTube网站需要提供更为丰富的电影和电视剧内容,

  11. Nigeria to step up tar sands activity

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    The Nigerian government has directed its Ministry of Mines, Power and Steel to assume responsibility for the exploration and exploitation of tar sands deposits in Bendel, Ondo and Oyo States. The directive resulted from a survey report by the University of Ife's geological consultancy unit on bituminous sand deposits in the area. The statement said the government was satisfied that there were large commercial quantities of the sands in the three states. The survey had reported that Nigeria could recover between 31 and 40 billion barrels of heavy crude from the tar sand deposits. Exploration for hydrocarbons is currently going on in Anambra and Lake Chad basins as well as the Benue Trough. Apart from the Nigerian National Petroleum Corporation, Shell Petroleum and Gulf Oil have begun exploration activities in the Ondo area. Meanwhile, Nigeria has had to import heavy crude from Venezuela, for processing at the Kaduna refinery.

  12. A Reappraisal of the Expulsion of Illegal Immigrants from Nigeria in 1983

    Directory of Open Access Journals (Sweden)

    Daouda Gary-Tounkara

    2016-04-01

    Full Text Available In recent years, Nigeria has been quietly expelling more and more immigrants from Niger, Mali, Chad and Cameroon. These foreigners – migrant workers or small traders – face the reinforcement of migration control and the blind fight of the government against Boko Haram. Despite its political instability, Nigeria remains a major immigration destination in West Africa. In this article, I analyze the “undocumented” expulsion of aliens in 1983, officially three million people. I argue that the expulsion was due to the economic crisis but also to a nationalist revenge against Ghana and a political calculation of President Shagari. This implies the exclusion of foreigners from the national labour market and the weakening of the supposed electoral base of his opponents.

  13. Une description philologique de quelques mots du français régional haïtien

    Directory of Open Access Journals (Sweden)

    Roberson Pierre

    2012-11-01

    Full Text Available Cet article décrit quelques exemples de mots relevant du français régional haïtien, autrement dit du français contemporain tel qu'il est représenté en Haïti. Dans une approche philologique, les auteurs sollicitent la méthodologie de la lexicographie différentielle francophone de manière à soulever, plus indirectement, quelques unes des questions d'ordre sociolinguistique qui ont toujours préoccupé Pierre Vernet. Sont traités à titre d'illustration les mots bérégène, bouillon, calalou*, camionette, carnet, chadèque, pistache, rigoise et suret(te.

  14. CERT TST December 2015 Visit Summary

    Energy Technology Data Exchange (ETDEWEB)

    Little, Robert Currier [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bailey, Teresa S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gamblin, G. Todd [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Olinger, Chad Tracy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pautz, Shawn D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Williams, Alan B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-25

    The annual PSAAP II TST visit to Texas A&M’s CERT Center was held on December 1-3, 2015. The agenda for the visit is attached. Non-TAMU attendees were: TST Members – Teresa Bailey (LLNL), Todd Gamblin (LLNL), Bob Little (LANL) – Chair, Chad Olinger (LANL), Shawn Pautz (SNL), Alan Williams (SNL);Other Lab staff – Skip Kahler (LANL), Ana Kupresanin (LLNL), and Rob Lowrie (LANL); AST Members – Nelson Hoffman (LANL) and Bob Voigt (Leidos) The TST wishes to express our appreciation to all involved with CERT for the high-quality posters and presentations and for the attention to logistics that enabled a successful visit. We have broken our comments into four sections: (1) Kudos, (2) Recommendations, (3) Feedback on Priorities for April Review, and (4) Follow-Up Activities with Labs.

  15. Impact on Outcomes of Changing Treatment Guideline Recommendations for Stroke Prevention in Atrial Fibrillation

    DEFF Research Database (Denmark)

    Chao, Tze-Fan; Liu, Chia-Jen; Tuan, Ta-Chuan; Wang, Kang-Ling; Lin, Yenn-Jiang; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chen, Tzeng-Ji; Chiang, Chern-En; Hsieh, Ming-Hsiung; Lip, Gregory Y H; Chen, Shih-Ann

    2016-01-01

    OBJECTIVE: To investigate the impact on outcomes of changing treatment guideline recommendations by comparing the proportion of patients with atrial fibrillation (AF) recommended oral anticoagulants (OACs) under the 2011 and 2014 American College of Cardiology/American Heart Association (ACC....../AHA) guidelines. PATIENTS AND METHODS: We used the "National Health Insurance Research Database" in Taiwan, which included 354,649 patients with AF from January 1, 1996 through December 31, 2011. Patients with a CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or...... transient ischemic attack) score of 2 or more and a CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female sex category) score of 2 or more were considered to have a definitive indication...

  16. EU Aid Conditionality in ACP Countries: Explaining Inconsistency in EU Sanctions Practice

    Directory of Open Access Journals (Sweden)

    Karen Del Biondo

    2011-09-01

    Full Text Available The EU is often criticised for using negative conditionality only in poor, strategically less important countries in the ACP region. However, whether and why there is inconsistency within the group of ACP countries has not been properly investigated. Therefore, this article investigates the reasons for the EU’s non-application of Article 96 of the Cotonou Agreement in five countries that can be considered typical cases where negative conditionality is generally imposed, namely countries that experienced flawed elections over the last ten years: Ethiopia, Rwanda, Nigeria, Kenya and Chad. On the one hand, the study confirms previous findings that security interests tend to trump the EU’s efforts to promote democratisation. On the other hand, the article adds that democratisation might not only conflict with the EU’s interests, but also with its objective to promote development and poverty reduction.

  17. Boko Haram’s International Reach

    Directory of Open Access Journals (Sweden)

    Ely Karmon

    2014-02-01

    Full Text Available Although most of Boko Haram’s terrorist activity is focused, for the moment, on Nigerian territory, this Research Note argues that it is already an important international jihadist organisation. The watershed that marks Boko Haram’s passage from a purely Nigerian phenomenon to an international jihadist actor is its attack on the United Nations Headquarters in Abuja, Nigeria’s capital, on August 26, 2011. The bulk of BH’s membership, the indiscriminate and cruel characteristic of its attacks, the complexity of the Nigerian religious and ethnic context, the sheer weight of the Nigerian state in an instable neighborhood - Cameroun, Niger, Chad, Mali - and its proximity to the jihadist battle front in the Sahel convert it into an immediate and infectious regional threat.

  18. Africa's Megafans and Their Tectonic Setting

    Science.gov (United States)

    Wilkinson, M. J.; Burke, K.

    2016-01-01

    Megafans are a really extensive continental sediment bodies, fluvially derived, and fan-shaped in planform. Only those >80 km long were included in this study. Africa's megafans were mapped for purposes of both comprehensive geomorphic description and as a method of mapping by remote sensing large probable fluvial sediment bodies (we exclude sediment bodies deposited in well defined, modern floodplains and coastal deltas). Our criteria included a length dimension of >80 km and maximum width >40 km, partial cone morphology, and a radial drainage pattern. Visible and especially IR imagery were used to identify the features, combined with topographic SRTM data. We identified 99 megafans most of which are unstudied thus far. Their feeder rivers responsible for depositing megafan sediments rise on, and are consequent drainages oriented down the slopes of the swells that have dominated African landscapes since approximately 34 Ma (the high points in Africa's so-called basin-and-swell topography [1]). Most megafans (66%) have developed along these consequent rivers relatively near the swell cores, oriented radially away from the swells. The vast basins between the swells provide accommodation for megafan sediment wedges. Although clearly visible remotely, most megafans are inactive as a result of incision by the feeder river (which then no longer operates on the fan surface). Two tectonic settings control the location of Africa's megafans, 66% on swell flanks, and 33% related to rifts. (i) Swell flanks Most megafans are apexed relatively near the core of the parent swell, and are often clustered in groups: e.g., six on the west and north flanks of the Hoggar Swell (Algeria), seven on the north and south flanks of the Tibesti Swell (Libya-Chad borderlands), twelve on the west flank of the Ethiopian Swell, four on the east flank of the East African Swell (Kenya), Africa's largest, and eight around Angola's Bié Swell (western Zambia, northern Namibia). A cluster of possible

  19. The Anticoagulated Atrial Fibrillation Patient Who Requires “Curative” Therapy for Prostate Carcinoma: a Bleeding Conundrum

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    James A. Reiffel, M.D

    2008-12-01

    Full Text Available With the aging of the population, the incidence of both prostate carcinoma (PCa and atrial fibrillation (AF has increased. Options for “curative therapy” PCa now include surgery, external beam radiation (EBT, and radioactive seed implantation (RSI. The latter two approaches, especially EBT, can produce radiation proctitis (RP with rectal bleeding (RB. This poses an issue for anticoagulating the elderly AF patient who develops PCa. The attached case report of a 77 year old male who was treated with a combination of RSI and “low dose” EBT followed by recurrent severe rectal bleeding demonstrates the significance of this problem. In the AF patient with a CHADS2 score of 2 or more, and hence an indication for chronic warfarin therapy, the therapy of subsequently detected PCa requires careful consideration of the risks associated with its therapeutic options.

  20. The Anticoagulated Atrial Fibrillation Patient Who Requires Curative Therapy for Prostate Carcinoma: a Bleeding Conundrum.

    Directory of Open Access Journals (Sweden)

    James A. Reiffel

    2008-12-01

    Full Text Available With the aging of the population, the incidence of both prostate carcinoma (PCa and atrial fibrillation (AF has increased.  Options for "curative therapy" PCa now include surgery, external beam radiation (EBT, and radioactive seed implantation (RSI.  The latter two approaches, especially EBT, can produce radiation proctitis (RP with rectal bleeding (RB.  This poses an issue for anticoagulating the elderly AF patient who develops PCa.  The attached case report of a 77 year old male who was treated with a combination of RSI and "low dose" EBT followed by recurrent severe rectal bleeding demonstrates the significance of this problem.  In the AF patient with a CHADS2 score of 2 or more, and hence an indication for chronic warfarin therapy, the therapy of subsequently detected PCa requires careful consideration of the risks associated with its therapeutic options.

  1. Joint Soviet--French investigations of the solar corona. 2. Photometry of solar corona of June 30, 1973

    International Nuclear Information System (INIS)

    The results are presented on a study of eclipse negative obtained on June 30, 1973, in Africa in the program of the Soviet--French experiment ''Dynamics of the White Corona'' by expeditions of Kiev University (Atar, Mauritania) and the Paris Astropysical Institute (Moussoro, Chad). The distributions of the total brightness of the corona out to rapprox. =4.5 R/sub sun/ and of its K and F components for the E and N directions are found with high accuracy on the basis of a new method of photometry and colorimetry using the images of stars down to 8.5/sup m/ as photometric standards. Neither reddening nor flattening of the dusty F component were detected at r-6 E/sub sun/

  2. Women Sex Importance in Stroke Patients with Atrial Fibrillation

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    Cemile Handan Mısırlı

    2014-08-01

    Full Text Available OBJECTIVE: It was shown the differences in age, risk factors and treatment between women and men in stroke patients with atrial fibrillation METHODS: The stroke patients with atrial fibrillation who were hospitalized in our department at the last 2 years were seperated into 2 groups of aged above 75 and below 75, investigated with CHADS2 and CHA2DS2VASc scores and looked at the sex differences of women and men. RESULTS: Stroke ratio according to sex was statistically meaningful especially in women above the age of 75. Risc factors also were founded in elderly women and CHA2DS2VASc scores were higher in women than men so more anticoagulan treatment were begun. No differences were shown between sexes at lone atrial fibrillation and no treatment were begun. CONCLUSION: Women with atrial fibrillation had more risk factors, higher stroke rate and higher anticoagulation treatment.

  3. Implantation of watchman left atrial appendage closure device at the ostium of the left atrial appendage to prevent thrombosis embolism%经导管左心耳封堵术预防房颤血栓栓塞

    Institute of Scientific and Technical Information of China (English)

    樊友启; 杨倩; 蒋峻; 何伟; 胡颖红; 严敏; 蒲朝霞; 李长岭; 刘先宝

    2014-01-01

    目的 评价中国房颤患者植入watchman左心耳封堵系统预防血栓栓塞的可行性和安全性.方法 入选年龄18至85岁之间的非瓣膜性心房颤动患者,CHADS2-VAS评分≥2分和HAS-BLED评分≥3分,且不愿意长期口服抗凝药物或口服抗凝药物有禁忌证.经股静脉途径,穿刺房间隔,将watchman左心耳封堵器输送系统置入左心房,植入watchman左心耳封堵装置至左心耳颈部.结果 入选4例心房颤动患者,年龄(74.75±8.69)岁,CHADS2-VAS评分(5.5±1.29)分,(4~7分)及HAS-BLED评分(3.75±0.5)分,(3~4分),均成功植入watchman左心耳封堵系统,手术时间(100.00±17.79) min.围手术期及术后2个月随访无出血及栓塞等并发症发生.结论 在中国房颤患者中植入watchman左心耳封堵器预防血栓栓塞是安全可行的.%Objective To evaluate the safety and feasibility of implanting the watchman left atrial appendage closure device at the ostium of the left atrial appendage to prevent thrombosis embolism in atrial fibrillation patients in China.Methods We selected non valvular atrial fibrillation patients with the age between 18 to 85,CHADS2-VAS score ≥2 and HAS-BLED score≥3,who do not want to take long-term oral anticoagulant drugs or have contraindications of use oral anticoagulant drugs.Via the femoral vein approach,after atrial septal puncture,we put the watchman left atrial appendage closure device delivery system into the left atrial appendage and implanted the watchman left atrial appendage closure device at the ostium of the left atial appendage.Results Four atrial fibrillation patients were enrolled,with average age (74.75 ±8.69) years old,average CHADS2-VAS score (5.5 ± 1.29) and HAS-BLED score (3.75 ± 0.5),average procedure time is (100.00 ± 17.79) min.All the patients were successfully implanted with the watchman left atrial appendage closure device.Peri procedures and after 2 months follow-up,no complications such as bleeding and thrombosis

  4. Analysis of seasonal characteristics of Sambhar Salt Lake, India, from digitized Space Shuttle photography

    Science.gov (United States)

    Lulla, Kamlesh P.; Helfert, Michael R.

    1989-01-01

    Sambhar Salt Lake is the largest salt lake (230 sq km) in India, situated in the northwest near Jaipur. Analysis of Space Shuttle photographs of this ephemeral lake reveals that water levels and lake basin land-use information can be extracted by both the digital and manual analysis techniques. Seasonal characteristics captured by the two Shuttle photos used in this study show that additional land use/cover categories can be mapped from the dry season photos. This additional information is essential for precise cartographic updates, and provides seasonal hydrologic profiles and inputs for potential mesoscale climate modeling. This paper extends the digitization and mensuration techniques originally developed for space photography and applied to other regions (e.g., Lake Chad, Africa, and Great Salt Lake, USA).

  5. Earth observations during Space Shuttle flight STS 50 - Columbia's mission to planet earth (June 25-July 9, 1992)

    Science.gov (United States)

    Lulla, Kamlesh P.; Helfert, Michael; Amsbury, David; Pitts, David; Evans, Cynthia; Wilkinson, Justin; Helms, David; Chambers, Mark; Brumbaugh, Fred; Richards, Richard N.

    1993-01-01

    A review of the imagery acquired during the STS 50 mission of the Space Shuttle is presented. The earth viewing photography from this flight includes photos of dust plumes over several portions of the Red Sea, Arabian Sea, Persian Gulf, the Mediterranean Sea, and the Atlantic Ocean. Over land, prominent dust plumes were seen over Iraq, North Africa, Sudan, and West Africa. The color infrared photography includes images of the tropical rain forests of South America and South and Southeast Asia. Other examples include photographs of floods in Argentina, photos of Lake Chad in Africa, Coastal Madagascar, the Aswan dam and the Nile, geologic features of North Africa, the center pivot irrigation land areas of Saudi Arabia, flooding in Asian rivers, and sediment plumes of South American and South and Southeast Asian coasts.

  6. A Human Vaccine Strategy Based On Chimpanzee Adenoviral and MVA Vectors That Primes, Boosts and Sustains Functional HCV Specific T-Cell Memory*

    Science.gov (United States)

    Swadling, Leo; Capone, Stefania; Antrobus, Richard D.; Brown, Anthony; Richardson, Rachel; Newell, Evan W.; Halliday, John; Kelly, Christabel; Bowen, Dan; Fergusson, Joannah; Kurioka, Ayako; Ammendola, Virginia; Sorbo, Mariarosaria Del; Grazioli, Fabiana; Esposito, Maria Luisa; Siani, Loredana; Traboni, Cinzia; Hill, Adrian; Colloca, Stefano; Davis, Mark; Nicosia, Alfredo; Cortese, Riccardo; Folgori, Antonella; Klenerman, Paul; Barnes, Eleanor

    2015-01-01

    A protective vaccine against hepatitis C virus (HCV) remains an unmet clinical need. HCV infects millions of people worldwide and is a leading cause of liver cirrhosis and hepatocellular cancer. Animal challenge experiments, immunogenetics studies and assessment of host immunity during acute infection highlight the critical role that effective T-cell immunity plays in viral control. In this first-in-man study we have induced antiviral immunity with functional characteristics analogous to those associated with viral control in natural infection, and improved upon a vaccine based on adenoviral vectors alone. We assessed a heterologous prime-boost vaccination strategy based on a replicative defective simian adenoviral vector (ChAd3) and modified vaccinia Ankara (MVA) vector encoding the NS3, NS4, NS5A and NS5B proteins of HCV genotype-1b. Analysis employed single cell mass cytometry (CyTOF), and HLA class-I peptide tetramer technology in healthy human volunteers. We show that HCV specific T-cells induced by ChAd3 are optimally boosted with MVA, and generate very high levels of both CD8+ and CD4+ HCV specific T-cells targeting multiple HCV antigens. Sustained memory and effector T-cell populations are generated and T-cell memory evolved over time with improvement of quality (proliferation and polyfunctionality) following heterologous MVA boost. We have developed a HCV vaccine strategy, with durable, broad, sustained and balanced T-cell responses, characteristic of those associated with viral control, paving the way for the first efficacy studies of a prophylactic HCV vaccine. PMID:25378645

  7. The CIRAD Contribution to Rinderpest Eradication

    International Nuclear Information System (INIS)

    Rinderpest, which was a major incentive for establishment of the first veterinary school at Lyon in 1764 and later of OIE, also motivated the implementation of an international training course in Maisons-Alfort (France) in 1921, which aimed to improve the control of rinderpest. This postgraduate teaching in exotic medicine was soon organized into an institute, Institut de medecine veterinaire exotique, then, the Institut d'Elevage et de Medecine Veterinaire Tropicale (IEMVT), which was created in 1948 and merged with other French agronomic institutes in 1984, to create CIRAD. For simplicity, this chapter uses the name CIRAD. All the scientists mentioned work at CIRAD unless otherwise stated. The history of CIRAD's contribution to rinderpest eradication is also the history of strong collaboration with national, regional and international veterinary services (OIE, FAO, AU-IBAR) and animal health research centres. A large and significant body of field and laboratory work was carried out during the period. A few years ago, it was still possible to meet pastoralists in remote areas of Chad or the Central African Republic who remembered seeing French vets use their goats to vaccinate cattle with the 'caprinized' rinderpest vaccine. Pan-African vaccination campaigns and the pledge for eradication. CIRAD was involved in all aspects of rinderpest research and control activities since the early 1950s. Most of this work was conducted in the national laboratories of Chad (Farcha; Provost, 1966), Senegal (Dakar) and Ethiopia (Debre Zeit; Lefevre and Domenech, 1974), which are now important components of their respective national animal disease control and research systems. Dakar and Debre Zeit laboratories are major international stakeholders in disease control, through the networks and reference centres of the West and Central Africa Veterinary Laboratory Network for Avian Influenza and other Transboundary Disease (RESOLAB, coordinated by FAO, OIE and AU-IBAR) and PANVAC

  8. Long-term efficacy of surgical ablation of atrial fibrillation in a low-volume centre

    Science.gov (United States)

    Zyśko, Dorota; Bielicki, Grzegorz; Obremska, Marta; Goździk, Anna; Kustrzycki, Wojciech

    2015-01-01

    Surgical ablation is a recommended procedure for patients with atrial fibrillation (AF) undergoing a cardiac surgery operation. However, the procedure is associated with significant risk of late recurrence of AF. The aim of the study was to assess the long-term efficacy of the procedure with respect to the comorbidities. The study group consisted of 22 patients: 9 women and 13 men, who underwent surgical AF ablation in the 2008-2013 period. The patients were interviewed by telephone and were asked to send their recently performed 12-lead electrocardiography (ECG). The semi-structured interview consisted of 25 items regarding the history of AF, concomitant comorbidities, lifelong syncopal history, smoking, family history of premature cardiovascular diseases, and current medical treatment. Furthermore, the Epworth test was performed to measure the daytime sleepiness, which in turn is related to the presence of obstructive sleep apnoea. On the basis of the obtained data, the CHADS2, and Epworth scale scores were calculated for each patient. As a result of the study six patients (27%) had sinus rhythm or paced dual chamber rhythm, and 16 patients had atrial fibrillation. The multivariate analysis revealed that Epworth scale scoring > 9, CHADS2 score > 0, and persistent type of AF were related to poor outcome of surgical ablation procedure. In conclusion, patients with AF treated with surgical ablation have similar prognosis of sinus rhythm maintenance to those treated with radiofrequency ablation. Moreover, the same predisposing factors play a significant role in AF recurrence both in surgical patients and in patients treated with radiofrequency ablation. PMID:26855645

  9. Transmission dynamics and economics of rabies control in dogs and humans in an African city.

    Science.gov (United States)

    Zinsstag, J; Dürr, S; Penny, M A; Mindekem, R; Roth, F; Menendez Gonzalez, S; Naissengar, S; Hattendorf, J

    2009-09-01

    Human rabies in developing countries can be prevented through interventions directed at dogs. Potential cost-savings for the public health sector of interventions aimed at animal-host reservoirs should be assessed. Available deterministic models of rabies transmission between dogs were extended to include dog-to-human rabies transmission. Model parameters were fitted to routine weekly rabid-dog and exposed-human cases reported in N'Djaména, the capital of Chad. The estimated transmission rates between dogs (beta(d)) were 0.0807 km2/(dogs x week) and between dogs and humans (beta(dh)) 0.0002 km2/(dogs x week). The effective reproductive ratio (R(e)) at the onset of our observations was estimated at 1.01, indicating low-level endemic stability of rabies transmission. Human rabies incidence depended critically on dog-related transmission parameters. We simulated the effects of mass dog vaccination and the culling of a percentage of the dog population on human rabies incidence. A single parenteral dog rabies-mass vaccination campaign achieving a coverage of least 70% appears to be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to postexposure prophylaxis (PEP), which is the current practice in Chad. PEP does not reduce future human exposure. Its cost-effectiveness is estimated at US $46 per disability adjusted life-years averted. Cost-effectiveness for PEP, together with a dog-vaccination campaign, breaks even with cost-effectiveness of PEP alone after almost 5 years. Beyond a time-frame of 7 years, it appears to be more cost-effective to combine parenteral dog-vaccination campaigns with human PEP compared to human PEP alone. PMID:19706492

  10. Crocodiles in the Sahara desert: an update of distribution, habitats and population status for conservation planning in Mauritania.

    Directory of Open Access Journals (Sweden)

    José C Brito

    Full Text Available BACKGROUND: Relict populations of Crocodylus niloticus persist in Chad, Egypt and Mauritania. Although crocodiles were widespread throughout the Sahara until the early 20(th century, increased aridity combined with human persecution led to local extinction. Knowledge on distribution, occupied habitats, population size and prey availability is scarce in most populations. This study evaluates the status of Saharan crocodiles and provides new data for Mauritania to assist conservation planning. METHODOLOGY/PRINCIPAL FINDINGS: A series of surveys in Mauritania detected crocodile presence in 78 localities dispersed across 10 river basins and most tended to be isolated within river basins. Permanent gueltas and seasonal tâmoûrts were the most common occupied habitats. Crocodile encounters ranged from one to more than 20 individuals, but in most localities less than five crocodiles were observed. Larger numbers were observed after the rainy season and during night sampling. Crocodiles were found dead in between water points along dry river-beds suggesting the occurrence of dispersal. CONCLUSION/SIGNIFICANCE: Research priorities in Chad and Egypt should focus on quantifying population size and pressures exerted on habitats. The present study increased in by 35% the number of known crocodile localities in Mauritania. Gueltas are crucial for the persistence of mountain populations. Oscillations in water availability throughout the year and the small dimensions of gueltas affect biological traits, including activity and body size. Studies are needed to understand adaptation traits of desert populations. Molecular analyses are needed to quantify genetic variability, population sub-structuring and effective population size, and detect the occurrence of gene flow. Monitoring is needed to detect demographical and genetical trends in completely isolated populations. Crocodiles are apparently vulnerable during dispersal events. Awareness campaigns focusing on

  11. Atrial fibrillation and stroke: epidemiology.

    Science.gov (United States)

    Reiffel, James A

    2014-04-01

    The statistics for AFib are impressive. (online video available at: http://education.amjmed.com/video.php?event_id=445&stage_id=5&vcs=1). The principal risk with AFib, stroke or thrombotic embolism, is increased 5-fold in some series; AFib accounts for ≥15% of all strokes in the United States, 36% of strokes for individuals aged >80, and up to 20% of cryptogenic strokes, which means >100,000-125,000 embolic strokes per year, of which >20% are fatal. Patients with ischemic stroke and AFib are significantly (PPrevention of these thromboembolic outcomes requires prophylactic anticoagulation therapy. The "gold standard" for anticoagulation has been warfarin, despite its well-known side effects and adherence challenges for patients. The recent approvals of several new, novel oral anticoagulation (NOAC) agents, however, presents physicians with a benefit/risk profile that represents an important advance over warfarin prophylaxis. The principal risk with all oral anticoagulants is bleeding. An important misconception about warfarin is that if anticoagulated patients bleed, the risk can be quickly reversed, but most trial experience has found that warfarin reversal requires 24 hours to halve the INR value. Reversal of anticoagulation with the NOACs is unproven at present; possible approaches are presented in this review, but since the NOACs have both rapid onsets of action and short biologic half-lives, they do not present the same reversal challenges as warfarin. Finally, physicians must be aware of thromboembolic risk assessment. The principal risk assessment scores are CHADS2, updated with the more recent CHA2DS2-VASc to provide more accurate assessment of low-risk patients; this review concludes with a novel flow-chart showing physicians how the CHADS2/CHA2DS2-VASc scoring systems can be used. PMID:24655742

  12. Post-procedural Dabigatran Versus Interrupted Warfarin Therapy Following Catheter Ablation for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Jeffrey Lin, MD; Sharon Shen, MD; Prashant Bhave, MD; Bradley Knight, MD; Martha Bohn, RN, BSN; Evaldas Giedrimas, MD; Taral K. Patel, MD; Alexandru Chicos, MD; Jeffrey Goldberger, MD; Leonard Ilkhanoff, MD, MS; Susan Kim, MD; Albert Lin, MD; Rod Passman, MD, MSCE.

    2014-02-01

    Full Text Available Purpose: Patients undergoing catheter ablation for atrial fibrillation (AF are at a higher risk of thromboembolic events post-procedure and therefore require therapeutic anticoagulation after ablation. Anticoagulation strategies include performing the procedure on or off therapeutic warfarin, though the latter approach requires post-procedure bridging therapy with low molecular-weight heparin (LMWH until a therapeutic INR is achieved. The purpose of this study is to compare the safety and efficacy of post-ablation dabigatran as compared to warfarin with LMWH bridging. Methods: We performed a single-center retrospective analysis of consecutive patients who underwent catheter ablation for AF between January 2010 and December 2012 and received either post-procedure warfarin with a LMWH bridge or dabigatran. Warfarin was started the night of ablation; LMWH was started the next morning and continued until the INR was ≥ 2.0. Dabigatran was started the morning post-ablation. Results: The analysis included 324 patients. Of these, mean age was 60 ± 9 years, 78% were male, 81% had CHADS2 scores of 0 or 1, and 181 (56% received dabigatran post-ablation. Patients who received dabigatran had lower CHADS2 scores and were more likely to be in NYHA Class I. At 30-days post-procedure, there were 0 thromboembolic or bleeding complications in the dabigatran group versus 4 (2.8% in the warfarin group (p=0.037. There were no deaths in either group at 30 days post-ablation. Conclusions: Post-ablation dabigatran appears safe and efficacious compared to an interrupted warfarin strategy with LMWH bridging.

  13. Water vapor budget associated to overshoots in the tropical stratosphere: mesoscale modelling study of 4–5 August 2006 during SCOUT-AMMA

    Directory of Open Access Journals (Sweden)

    X. M. Liu

    2010-02-01

    Full Text Available The aim of this paper is to study the impacts of overshooting convection at a local scale on the water distribution in the tropical UTLS. Overshooting convection is likely to be one of the key processes controlling the entry of water vapour amount in the stratosphere by injecting ice crystals above the tropopause which later sublimate and hydrate the lower stratosphere. For this purpose, we quantify the individual impact of two overshooting cases in Africa observed during SCOUT-AMMA: the case of 4 August 2006 over Southern Chad which is likely to have influenced the water vapour measurements by micro-SDLA and FLASH-B from Niamey on 5 August, and the case of a mesoscale convective system over Aϊr on 5 August 2006. We make use of high resolution (down to 1 km horizontally three nested grid simulations with the three-dimensional regional atmospheric model BRAMS (Brazilian Regional Atmospheric Modelling System. In both cases, BRAMS succeeds in simulating the main features of the convective activity, as well as overshooting convection, thought the exact position and time of the overshoots indicated by MSG brightness temperature difference is not fully reproduced (typically 1° in latitude compared with the overshoots indicated by brightness temperature difference from satellite observations for both cases, and several hours shift the Aϊr case on 5 August 2006. Total water budgets associated with these two events show a significant injection of ice particles above the tropopause with maximum values of about 3.7 ton s−1 for the Chad case (4 August and 1.4 ton s−1 for the Aϊr case (5 August, and a total cross tropopause transport of about 3300 ton h−1 for the Chad case and 2400 ton h−1 for the Aϊr case in the third domain of simulation. The order of magnitude of these modelled fluxes is lower but comparable with similar studies in other tropical areas based on models. These two estimations exhibit

  14. Four African Nations Agree to Water Management Programme

    International Nuclear Information System (INIS)

    Full text: Seeking to improve their management of water resources, four northeast African nations today agreed at the International Atomic Energy Agency (IAEA) to establish a long-term framework for utlizing a key underground water system. Chad, Egypt, Libya and Sudan signed a Strategic Action Programme (SAP) that aims to optimize the equitable use of the Nubian Sandstone Aquifer System, a huge water resource that lies beneath the four nations. The SAP also commits the countries to strengthen and build upon a previously existing regional coordination mechanism, in part by establishing a new Joint Authority for the Nubian Aquifer System. The Programme lays the groundwork for improving cooperation among the four arid nations and for strengthening their capacity to monitor and manage the aquifer effectively. With growing populations and decreasing water availability from other sources in the region, the aquifer is under mounting pressure. Removing water without a clear understanding of transboundary and other implications threatens water quality and has the potential to harm biodiversity and accelerate land degradation. The agreement resulted from a joint Technical Cooperation project of the United Nations Development Programme (UNDP) and the Global Environment Facility (GEF), the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the IAEA. ''I congratulate all involved on this significant achievement,'' said IAEA Director General Yukiya Amano. ''Water is a key resource, and effective management and use of such water resources is essential for the future. The agreement of the Strategic Action Programme is the result of real cooperation between the four States, the Agency and UNDP-GEF. I am confident that this Programme will be a success and will benefit the people of the region. This positive project experience benefits strengthened and expanded cooperation between the IAEA and the UNDP-GEF.'' ''UNDP would like to congratulate the

  15. 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

  16. 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

  17. A viral vectored prime-boost immunization regime targeting the malaria Pfs25 antigen induces transmission-blocking activity.

    Directory of Open Access Journals (Sweden)

    Anna L Goodman

    Full Text Available The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63, human adenovirus serotype 5 (AdHu5 and modified vaccinia virus Ankara (MVA viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25 resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera. In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit

  18. Coal in sub-Saharan-African countries undergoing desertification

    Science.gov (United States)

    Weaver, J. N.; Brownfield, M. E.; Bergin, M. J.

    Coal has been reported in 11 of the 16 sub-Saharan countries discussed in this appraisal: Mauritania, Senegal, Mali, Niger, Benin, Nigeria, Cameroon, Central African Republic, Sudan, Ethiopia, and Somalia. No coal occurrences have been reported in Gambia, Togo, Burkina, Chad, and Djibouti but coal may be present within these countries because neighboring countries do contain coal-bearing rocks. Most of these countries are undergoing desertification or will in the near future. Wood, directly or in the form of charcoal, constitutes two-thirds of the fuel used in Africa. Destruction of forest and shrub lands for fuel is occurring at an increasing rate because of desertification and increasing energy demands. The decline in biological productivity, coupled with concentration of population in areas where water is available and crops may be grown, leads to increasing shortages of wood for fuel. Part of the present and future energy needs of the sub-Saharan region could be met by use of indigenous coal and peat. Nine sedimentary basins, completely or partially within the sub-Saharan region, have the potential of either coal and/or peat deposits of economic value: 1- Senegal Basin, 2- Taoudeni Basin and Gao Trough, 3- Niger Basin, 4- Chad Basin, 5- Chari Basin, 6- Benue Trough (Depression), 7- Sudan Trough, 8- Plateau and Rift Belt, and 9- Somali Basin. Niger and Nigeria are the only countries in sub-Saharan Africa in which coal is presently being mined as a fuel source for powerplants and domestic use. Peat occurs in the deltas, lower river, and interdunal basin areas of Senegal, Mauritania, and Sudan. Peat can be used as an alternate fuel source and is currently being tested as a soil amendment in the agricultural sector. Coal and peat exploration and development studies are urgently required and should be initiated so the coal and peat utilization potential of each country can be determined. The overall objective of these studies is to establish, within the sub

  19. Environment of paleowater in Sudan

    International Nuclear Information System (INIS)

    Many natural and environmental developments created the conditions for paleowater occurrence in Sudan and possibly other areas. The major developments include: geological, structural and climatic. The geological environment includes the formation of Basement Complex (BC), which are the oldest rocks emplaced during Pre-Cambrian to the early Jurassic followed by the severe erosion, magmatism and deformation during the Jurassic. The uncomfortable deposition of the sedimentary rocks started in the Paleozoic and continued in association with the tectonic activities. Structural features resulted from the frequent tectonic activities controlled the configuration and geographical distribution of the sedimentary basins. The NW Central African Shear Zone CASZ, slip fault Wrench Strike to the West of the CASZ and the Garaf Strike Slip fault led to the establishment of depressions and deposition of the Paleozoic and Mesozoic sediments forming the sedimentary basins in Northwest (Sahara), in Southwest (Bagara) and in the east central (R Atbra)of Sudan respectively. The paleoclimatic investigations in the region covering: Lake Chad, the Nile system, Ethiopian Plata, Libya and Egypt suggested humid conditions between 40,000 and 3,000 Bp. The wet period was interrupted by dry periods. The early wet periods were recorded in Lake Chad. The estimated age of Paleowater cluster between 30,000-20,000 and 10,000 and 3000 BP and few ages between 10,000 and 20,000 PB in agreement with the defined dry period between 20,000 and 13,000 BP. The recharge of the Nubian aquifer remains a debatable topic. The so far conducted studies using environmental isotopes and hydrochemistry on the basis of conventional approaches suggest. The infiltration rate of water from the rainfall is estimated at 0.4 and 1.0 mm/y in the arid zones in the north (R Atbra Basin) and increases up to 10.0mm/y in the relatively wet areas in the south (Bagara Basin). The lateral recharge from the Nile system is evident up to

  20. Comparison among five hydrodynamic codes with a diverging-converging nozzle experiment

    International Nuclear Information System (INIS)

    A realistic open-cycle gas-core nuclear rocket simulation model must be capable of a self-consistent nozzle calculation in conjunction with coupled radiation and neutron transport in three spatial dimensions. As part of the development effort for such a model, five hydrodynamic codes were used to compare with a converging-diverging nozzle experiment. The codes used in the comparison are CHAD, FLUENT, KIVA2, RAMPANT, and VNAP2. Solution accuracy as a function of mesh size is important because, in the near term, a practical three-dimensional simulation model will require rather coarse zoning across the nozzle throat. In the study, four different grids were considered. (1) coarse, radially uniform grid, (2) coarse, radially nonuniform grid, (3) fine, radially uniform grid, and (4) fine, radially nonuniform grid. The study involves code verification, not prediction. In other words, the authors know the solution they want to match, so they can change methods and/or modify an algorithm to best match this class of problem. In this context, it was necessary to use the higher-order methods in both FLUENT and RAMPANT. In addition, KIVA2 required a modification that allows significantly more accurate solutions for a converging-diverging nozzle. From a predictive point of view, code accuracy with no tuning is an important result. The most accurate codes on a coarse grid, CHAD and VNAP2, did not require any tuning. Their main comparison among the codes was the radial dependence of the Mach number across the nozzle throat. All five codes yielded a very similar solution with fine, radially uniform and radially nonuniform grids. However, the codes yielded significantly different solutions with coarse, radially uniform and radially nonuniform grids. For all the codes, radially nonuniform zoning across the throat significantly increased solution accuracy with a coarse mesh. None of the codes agrees in detail with the weak shock located downstream of the nozzle throat, but all the

  1. Hydrocarbon Prospectivity of Nigeria's Inland Basins: From the View Point of Organic Geochemistry and Organic Petrology

    International Nuclear Information System (INIS)

    The inland basins of Nigeria comprise the Anambra basin, the lower, middle and upper Benue trough, the southeastern sector of the Chad basin, the Mid-Niger (Bida) basin, and the Sokoto basin. Organic geochemical and organic petrologic studies indicate that coal beds constitute major potential source rocks in the whole of the Benue trough (Anambra basin inclusive). The generation and production of liquid and i gaseous hydrocarbons from coal beds presently is world-wide indisputable. In the Anambra basin, the coal beds in the Mamu Formation have TOC contents of up to 60.8wt%, mean Hydrogen Index (HI) of 364mgHC/gTOC, vitrinite reflectivity (Ro) of 0.54 to 0.56% and Tmax 430 to 433degrees C. Biomarker data indicate a dominance of high molecular weight : n-alkanes, very high pristane/phytane ratios, pronounced odd-over-even predominance (OEP), preponderance of C29 regular steranes but with also relatively high contents of C28. In the middle Benue trough, the coal beds of the Awgu Formation have TOC contents of up to 79.1 Owt%, Ro of 0.83 to 1.07%, and mean HI of 281 mgHC/gTOC; unimodal distributions of both low and high molecular weight n-alkanes with no obvious OEP, and a predominance of C29 steranes but also with relatively high contents of C27 and C28. Coal beds from the Lamja Formation in the upper Benue trough yielded TOC contents of up to 50.7wt% with HI of 184mgHC/gTOC, Ro of 0.70 to 0.73%, low and high molecular weights n- alkane dominance with an unpronounced OEP, high pristane/phytane ratios, and very high contents of C29 regular steranes. On a basinal evaluation level, incorporating source rock data from the other formations in the respective sectors, plots on the modified Van Krevelen diagram alongside biomarker and maceral data indicate good i to fair source rock qualities (oil and gas) in the Anambra basin and middle Benue trough; and fair to poor (gaseous to dry) in the upper Benue trough and the Chad basin, with sporadic good to fair source rock

  2. Geochemical and isotopic characterization of the Bodélé Depression dust source and implications for transatlantic dust transport to the Amazon Basin

    Science.gov (United States)

    Abouchami, Wafa; Näthe, Kerstin; Kumar, Ashwini; Galer, Stephen J. G.; Jochum, Klaus Peter; Williams, Earle; Horbe, Adriana M. C.; Rosa, João W. C.; Balsam, William; Adams, David; Mezger, Klaus; Andreae, Meinrat O.

    2013-10-01

    The Bodélé Depression (Chad) in the central Sahara/Sahel region of Northern Africa is the most important source of mineral dust to the atmosphere globally. The Bodélé Depression is purportedly the largest source of Saharan dust reaching the Amazon Basin by transatlantic transport. Here, we have undertaken a comprehensive study of surface sediments from the Bodélé Depression and dust deposits (Chad, Niger) in order to characterize geochemically and isotopically (Sr, Nd and Pb isotopes) this dust source, and evaluate its importance in present and past African dust records. We similarly analyzed sedimentary deposits from the Amazonian lowlands in order to assess postulated accumulation of African mineral dust in the Amazon Basin, as well as its possible impact in fertilizing the Amazon rainforest. Our results identify distinct sources of different ages and provenance in the Bodélé Depression versus the Amazon Basin, effectively ruling out an origin for the Amazonian deposits, such as the Belterra Clay Layer, by long-term deposition of Bodélé Depression material. Similarly, no evidence for contributions from other potential source areas is provided by existing isotope data (Sr, Nd) on Saharan dusts. Instead, the composition of these Amazonian deposits is entirely consistent with derivation from in-situ weathering and erosion of the Precambrian Amazonian craton, with little, if any, Andean contribution. In the Amazon Basin, the mass accumulation rate of eolian dust is only around one-third of the vertical erosion rate in shield areas, suggesting that Saharan dust is "consumed" by tropical weathering, contributing nutrients and stimulating plant growth, but never accumulates as such in the Amazon Basin. The chemical and isotope compositions found in the Bodélé Depression are varied at the local scale, and have contrasting signatures in the "silica-rich" dry lake-bed sediments and in the "calcium-rich" mixed diatomites and surrounding sand material. This

  3. Surface water - groundwater relationship in the downstream part of the Komadougou Yobe River (Eastern Sahelian Niger)

    Science.gov (United States)

    Hector, B.; Genthon, P.; Luxereau, A.; Descloîtres, M.; Moumouni Moussa, A.; Abdou, H.

    2012-04-01

    The Komadougou Yobe (KY) is a temporary river meandering on nearly 100 km along the Niger/Nigeria border in its lower part, before reaching the endoreic Lake Chad. There, seasonal flow from July to January is related to rainfall amount on the upstream Jos Plateau, Nigeria. In the semi-arid downstream area (350 mm annual rainfall in Diffa, Niger) the KY is the main source of recharge for the sandy quaternary aquifer which is used both for irrigation and for drinking water supply. The borders of the KY in Niger are subjected to an agricultural development involving intensive irrigated cropping of sweet pepper mainly produced for sale in Nigeria. Irrigation waters are mainly extracted from the KY, and therefore irrigation must stop when the River runs dry, but irrigation from wells is now developing with an increased risk of soil salinization. The flow rate of the KY has been impacted both by the 80s and 90s droughts, also underwent by the entire Sahel, and by the building up of a series of dams starting from the 70s in Nigeria. Therefore the KY and its relations with the underlying groundwaters should be carefully monitored to provide guidelines for policy makers in charge of the development of this area. However, in this remote area, data are scarce and often discontinuous : there are for example no continuous groundwater level data from before the drought. As part of the Lake Chad French IRD project, series of campaigns involving water level, exploration geophysics, gravity, soil sampling and social studies have been carried out between 2008 and 2011. They allowed to build a numerical model for groundwater-river interactions which in some instances has been compared with previously recorded data. This model is then forced with theoretical climatic senarii based on humid 60s data and data from the drought period. This allows discussing the relationships between the river and groundwaters in a changing climate. Our results militate for the setting up of a limited

  4. Increasing Use of Postpartum Family Planning and the Postpartum IUD: Early Experiences in West and Central Africa.

    Science.gov (United States)

    Pleah, Tsigue; Hyjazi, Yolande; Austin, Suzanne; Diallo, Abdoulaye; Dao, Blami; Waxman, Rachel; Karna, Priya

    2016-08-11

    A global resurgence of interest in the intrauterine device (IUD) as an effective long-acting reversible contraceptive and in improving access to a wide range of contraceptive methods, as well as an emphasis on encouraging women to give birth in health care facilities, has led programs to introduce postpartum IUD (PPIUD) services into postpartum family planning (PPFP) programs. We describe strategic, organizational, and technical elements that contributed to early successes of a regional initiative in West and Central Africa to train antenatal, maternity, and postnatal care providers in PPFP counseling for the full range of available methods and in PPIUD service delivery. In November 2013, the initiative provided competency-based training in Guinea for providers from the main public teaching hospital in 5 selected countries (Benin, Chad, Côte d'Ivoire, Niger, and Senegal) with no prior PPFP counseling or PPIUD capacity. The training was followed by a transfer-of-learning visit and monitoring to support the trained providers. One additional country, Togo, replicated the initiative's model in 2014. Although nascent, this initiative has introduced high-quality PPFP and PPIUD services to the region, where less than 1% of married women of reproductive age use the IUD. In total, 21 providers were trained in PPFP counseling, 18 of whom were also trained in PPIUD insertion. From 2014 to 2015, more than 15,000 women were counseled about PPFP, and 2,269 women chose and received the PPIUD in Benin, Côte d'Ivoire, Niger, Senegal, and Togo. (Introduction of PPIUD services in Chad has been delayed.) South-South collaboration has been central to the initiative's accomplishments: Guinea's clinical centers of excellence and qualified trainers provided a culturally resonant example of a PPFP/PPIUD program, and trainings are creating a network of regional trainers to facilitate expansion. Two of the selected countries (Benin and Niger) have expanded their PPFP/PPUID training

  5. Radar scattering of linear dunes and mega-yardangs: Application to Titan

    Science.gov (United States)

    Paillou, Philippe; Seignovert, Benoît; Radebaugh, Jani; Wall, Stephen

    2016-05-01

    The Ku-band (13.8 GHz - 2.2 cm) RADAR instrument onboard the Cassini-Huygens spacecraft has revealed the richness of the surface of Titan, as numerous seas, lakes, rivers, cryo-volcanic flows and vast dune fields have been discovered. Linear dunes are a major geomorphological feature present on Titan, covering up to 17% of its surface, mainly in equatorial regions. However, the resolution of the RADAR instrument is not good enough to allow a detailed study of the morphology of these features. In addition, other linear wind-related landforms, such as mega-yardangs (linear wind-abraded ridges formed in cohesive rocks), are likely to present a comparable radar signature that could be confused with the one of dunes. We conducted a comparative study of the radar radiometry of both linear dunes and mega-yardangs, based on representative terrestrial analogues: the linear dunes located in the Great Sand Sea in western Egypt and in the Namib Desert in Namibia, and the mega-yardangs observed in the Lut Desert in eastern Iran and in the Borkou Desert in northern Chad. We analysed the radar scattering of both terrestrial linear dunes and mega-yardangs, using high-resolution radar images acquired by the X-band (9.6 GHz - 3.1 cm) sensor of the TerraSAR-X satellite. Variations seen in the radar response of dunes are the result of a contrast between the dune and interdune scattering, while for mega-yardangs these variations are the result of a contrast between ridges and erosion valleys. We tested a simple surface scattering model, with parameters derived from the local topography and surface roughness estimates, to accurately reproduce the radar signal variations for both landforms. It appears that we can discriminate between two types of dunes - bare interdunes as in Egypt and sand-covered interdunes as in Namibia, and between two types of mega-yardangs - young yardangs as in Iran and older ones as in Chad. We applied our understanding of the radar scattering to the analysis of

  6. A revision of the Pheroliodidae, fam. n. (Acari: Oribatei

    Directory of Open Access Journals (Sweden)

    Adilson D. Paschoal

    1986-01-01

    Full Text Available The new family Pheroliodidae, herei nproposed, includes the following genera and species Pheroliodes Grandjean (in whose synonymy Pedrocortesia Hammer is placed, with the species: casa-branquensis, sp. n. (Brazil, São Paulo, Casa Branca, pellitus, sp. n. (Brazil, São Paulo, Piracicaba, nemoricultricis, sp. n. (Brazil, São Paulo, Piracicaba, wehnekei (Willmann (Guatemala, Venezuela, roblensis Covarrubias (Chile, mirabilis (Hammer, n. comb. (Argentina: Pedrocortesia elegans Hammer, P. intermedia Hammer, both from Peru, P. fissurata Balogh & Mahunka and P. inaequalis Balogh & Mahunka, both from Mongolia, P. franzi Balogh (Chad, P. africana Balogh (Kenya, P. vermicularis Balogh (New Guinea and P. sculptrata Aoki (Corea are considered incertae sedis; Lopholiodes, gen. n., includes the species micropunctinatum, sp. n., the type-species (Brazil, São Paulo, Anhumas and macropunctinatum, sp. n. (Brazil, São Paulo, Piracicaba: Octoliodes, gen n., includes the species leuteomarginatus (Hammer, n. comb., the type-species (New ealand and rotoruensis (Hammer, n. comb. (New Zealand: and Licnoliodes Grandjean, with the species: andrei Grandjean, type-species (Spain and Algeria, adminensis Grandjean, type-species (Spain and Algeria, adminensis Grandjean (Maroc, Algeria, Spain and apunctatus Mahunka (Greece.A nova família aqui descrita, Pheroliodidae, inclui os seguintes gêneros e espécies: Pheroliodes Grandjean (em cuja sinonímia vai incluído Pedrocortesia Hammer, com as seguintes espécies: casa-branquensis, sp. n. (Brasil, São Paulo, Casa Branca, pellitus, sp. n. (Brasil, São Paulo, Piracicaba, nemoricultricis, sp. n. (Brasil, São Paulo, Piracicaba, wehnekei (Willmann (Guatemala, Venezuela, roblensis Covarrubias (Chile, mirabilis (Hammer, n. comb. (Argentina: Pedrocortesia elegans Hammer, P. intermedia Hammer, ambas do Peru, P. fissurata Balogh & Mahunka (Mongólia, inaequalis Balogh & Mahunka (Mongólia, franzi Balogh (Chad, P. africana Balogh

  7. Cost-effectiveness of edoxaban versus rivaroxaban for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in the US

    Science.gov (United States)

    Miller, Jeffrey D; Ye, Xin; Lenhart, Gregory M; Farr, Amanda M; Tran, Oth V; Kwong, W Jackie; Magnuson, Elizabeth A; Weintraub, William S

    2016-01-01

    Background Understanding the value of new anticoagulation therapies compared with existing therapies is of paramount importance in today’s cost-conscious and efficiency-driven health care environment. Edoxaban and rivaroxaban for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients with CHADS2 scores ≥2 have been evaluated in pivotal trials versus warfarin. The relative value of edoxaban versus rivaroxaban would be of interest to health care stakeholders and patients who prefer a once-daily treatment option for long-term stroke prevention in NVAF. Objective To evaluate the relative cost-effectiveness of two once-daily regimens of novel oral anticoagulation therapy – edoxaban (60 mg/30 mg dose-reduced) versus rivaroxaban (20 mg/15 mg dose-reduced) – for stroke prevention in NVAF patients from a US health-plan perspective. Materials and methods A Markov model simulated lifetime risk and treatment of stroke, systemic embolism, major bleeding, clinically relevant nonmajor bleeding, myocardial infarction, and death in NVAF patients treated with edoxaban or rivaroxaban. Efficacy and safety data were derived from a network meta-analysis that utilized data from patients enrolled in ENGAGE AF-TIMI 48 and ROCKET-AF. Health care cost and utility data were obtained from published sources. Incremental cost-effectiveness ratios of $150,000 per quality-adjusted life year (QALY) gained were used as thresholds for “highly cost-effective”, “cost-effective”, and “not cost-effective” treatment options, respectively, as per American Heart Association/American College of Cardiology guidelines. Results Edoxaban was dominant relative to rivaroxaban, such that it was associated with lower total health care costs and better effectiveness in terms of QALYs in the base-case analysis. Results were supported by probabilistic sensitivity analyses that showed edoxaban as either dominant or a highly cost-effective alternative (incremental cost

  8. How tall is an elephant? Two methods for estimating elephant height

    Directory of Open Access Journals (Sweden)

    F. Della Rocca

    2007-02-01

    Full Text Available Shoulder height is a reliable indicator of age for African elephants (Loxodonta africana, and is therefore an important parameter to be recorded in field studies of population ecology of these pachyderms. However, it can be somewhat difficult to estimate with precision the shoulder height of free-ranging elephants because of several reasons, including the presence of drops and vegetation cover and the potential dangerousness of approaching them in the wild. Here I test two alternative models for estimating shoulder height of elephants. In both models, the equipment needed to generate the height estimates is minimal, and include a telemeter and a digital photo-camera furnished with an ×16 zoom. The models are based respectively on a linear regression approach and on a geometric formula approach, and put into a relationship the linear distance between the observer and the animal, the number of pixels of an elephant silhouette as taken from digital photos, and the absolute height of the animal. Both methods proved to have a very small measurement error, and were thus reliable for field estimates of elephant shoulder heights. The model based on a geometric formula was used to estimate the shoulder height distribution of an elephant population in a savannah region of West Africa (Zakouma National Park, Chad. I demonstrated that Zakouma elephants were among the tallest populations in Africa, with growth rates being highest throughout the first five years of life.

  9. Dabigatran in Secondary Stroke Prevention: Clinical Experience with 106 Patients

    Directory of Open Access Journals (Sweden)

    Alicia DeFelipe-Mimbrera

    2014-01-01

    Full Text Available Introduction. Our aim was to analyze our clinical experience with dabigatran etexilate in secondary stroke prevention. Methods. We retrospectively included patients starting dabigatran etexilate for secondary stroke prevention from March 2010 to December 2012. Efficacy and safety variables were registered. Results. 106 patients were included, median follow-up of 12 months (range 1–31. Fifty-six females (52.8%, mean age 76.4 (range 50–95, SD 9.8, median CHADS2 4 (range 2–6, CHA2DS2-VASc 5 (range 2–9, and HAS-BLED 2 (range 1–5. Indication for dabigatran etexilate was ischemic stroke in 101 patients and acute cerebral hemorrhage (CH due to warfarin in 5 (4.7%. Dabigatran etexilate 110 mg bid was prescribed in 71 cases (67% and 150 mg bid was prescribed in the remaining. Seventeen patients (16% suffered 20 complications during follow-up. Ischemic complications (10 were 6 transient ischemic attacks (TIA, 3 ischemic strokes, and 1 acute coronary syndrome. Hemorrhagic complications (10 were CH (1, gastrointestinal bleeding (6, mild hematuria (2, and mild metrorrhagia (1, leading to dabigatran etexilate discontinuation in 3 patients. Patients with previous CH remained uneventful. Three patients died (pneumonia, congestive heart failure, and acute cholecystitis and 9 were lost during follow-up. Conclusions. Dabigatran etexilate was safe and effective in secondary stroke prevention in clinical practice, including a small number of patients with previous history of CH.

  10. The state, refugees and migration in sub-Saharan Africa.

    Science.gov (United States)

    Akokpari, J K

    1998-01-01

    Migration and refugee movements could significantly decline in sub-Saharan African countries. However, countries must redistribute meager resources equitably and engage in environmental protection. Refugee and migrant populations have increased in sub-Saharan Africa during 1969-95, from 700,000 to 6.8 million. This study examined the causes of migration and the implications for host countries. Doornbos (1990) identifies the root problem as the partisan nature of African politics and the incapacity to manage ecological degradation. The African state is wholly or partially responsible for the creation of conflicts. Examples abound in Zaire, South Africa, Sudan, Rwanda, Burundi, Somalia, Ethiopia, Liberia, Congo, and Chad. State partisanship is also evident in Angola, Mozambique, Uganda, and Sierra Leone. An estimated 10 million Africans, in 1985, left their homes due to wars, government repression, or the inability of land to support them. In 1994, USAID estimated that 11.6 million Africans in 10 countries were threatened by famine from drought. Environmental degradation has generated conflicts. Africa's marginalized economy results in recession, unemployment, inflation, and distributional conflicts. Democratization has brought conflicts between the state, civil society, and exiles. Refugees face homelessness, poverty, emotional distress, inadequate food, and disease. Host countries face security threats, pressure on limited resources, rebellions from refugees and their involvement with foreign mercenaries, local conflicts between native and refugee populations, and environmental degradation from refugees. PMID:12293796

  11. The benefits of 'One Health' for pastoralists in Africa.

    Science.gov (United States)

    Greter, Helena; Jean-Richard, Vreni; Crump, Lisa; Béchir, Mahamat; Alfaroukh, Idriss O; Schelling, Esther; Bonfoh, Bassirou; Zinsstag, Jakob

    2014-01-01

    'One health' is particularly suited to serve mobile pastoralists. Dinka pastoralists in Sudan inspired Calvin Schwabe to coin the term 'one medicine', indicating that there is no difference in paradigm between human and veterinary medicine. Our contemporary definition of 'one health' is any added value in terms of improved health of humans and animals or financial savings or environmental services resulting from a closer cooperation of human and animal health sectors. Here we present a summary of 'one health' studies with mobile pastoralists in Africa which were done in research partnership, demonstrating such an added value. Initial joint human and animal health studies revealed higher livestock vaccination coverage than in the pastoralist community, leading to joint animal and human vaccination intervention studies which demonstrated a better access to primary health care services for pastoralists in Chad. Further simultaneous animal and human serological studies showed that camel breeding was associated with human Q-fever seropositivity. In Borana communities in Ethiopia, human cases of Mycobacterium bovis infection could be related to strains isolated from cattle. A challenge remained with regard to how to assess vaccination coverage in mobile populations. With the advent of mobile phones, health and demographic surveillance could be established for mobile pastoralists and their animals. This presents vast possibilities for surveillance and control of human and animal diseases. Pastoralists prefer a 'one health' approach and therefore contribute toward the validation of this concept by showing real added value of the cooperation between human and animal health services. PMID:25005234

  12. Y-chromosome E haplogroups: their distribution and implication to the origin of Afro-Asiatic languages and pastoralism.

    Science.gov (United States)

    Gebremeskel, Eyoab I; Ibrahim, Muntaser E

    2014-12-01

    Archeological and paleontological evidences point to East Africa as the likely area of early evolution of modern humans. Genetic studies also indicate that populations from the region often contain, but not exclusively, representatives of the more basal clades of mitochondrial and Y-chromosome phylogenies. Most Y-chromosome haplogroup diversity in Africa, however, is present within macrohaplogroup E that seem to have appeared 21 000-32 000 YBP somewhere between the Red Sea and Lake Chad. The combined analysis of 17 bi-allelic markers in 1214 Y chromosomes together with cultural background of 49 populations displayed in various metrics: network, multidimensional scaling, principal component analysis and neighbor-joining plots, indicate a major contribution of East African populations to the foundation of the macrohaplogroup, suggesting a diversification that predates the appearance of some cultural traits and the subsequent expansion that is more associated with the cultural and linguistic diversity witnessed today. The proto-Afro-Asiatic group carrying the E-P2 mutation may have appeared at this point in time and subsequently gave rise to the different major population groups including current speakers of the Afro-Asiatic languages and pastoralist populations. PMID:24667790

  13. Retinol assessment among women and children in sahelian mobile pastoralists.

    Science.gov (United States)

    Bechir, M; Schelling, E; Kraemer, K; Schweigert, F; Bonfoh, B; Crump, L; Tanner, M; Zinsstag, J

    2012-06-01

    Micronutrient deficiencies are widespread in developing countries, particularly in remote communities such as mobile pastoralists. The nutritional and vitamin A status of this population is not well-documented in Chad. This study assessed serum retinol levels among women and children under five-year-old in nomadic and semi-nomadic pastoralist and rural-settled communities, who are similarly exposed to risk factors such as gastrointestinal parasitic infection, anaemia and emaciation. The novel method of portable fluorometry was used for the first time to measure β-carotene and retinol levels in a pastoral nomadic area. Moderate level blood retinol deficiency (<0.7 μmol/L) was observed in 5% (CI 1-11) of nomadic, 29% (CI 13-45) of semi-nomadic and 22% (CI 8-35) of sedentary women. In children, 1% (CI 0.1-4), 17% (CI 9-25) and 28% (CI 18-39), respectively, had moderate level blood retinol deficiency. In nomadic communities, women and children had blood retinol levels close to normal. Deficiency of retinol was strongly linked with lifestyle (nomadic, semi-nomadic and settled) among women and lifestyle and age among children. The results support an ecological linkage between human retinol levels and livestock milk retinol. This study shows the feasibility of portable retinol and β-carotene measurement in human blood as well as human and animal milk under remote field conditions, but the approach requires further validation. PMID:22825749

  14. First early hominin from central Africa (Ishango, Democratic Republic of Congo.

    Directory of Open Access Journals (Sweden)

    Isabelle Crevecoeur

    Full Text Available Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma, and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25 from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma.

  15. Climate change and climate systems influence and control the atmospheric dispersion of desert dust: implications for human health

    Science.gov (United States)

    Griffin, Dale W.

    2010-01-01

    The global dispersion of desert dust through Earth’s atmosphere is greatly influenced by temperature. Temporal analyses of ice core data have demonstrated that enhanced dust dispersion occurs during glacial events. This is due to an increase in ice cover, which results in an increase in drier terrestrial cover. A shorter temporal analysis of dust dispersion data over the last 40 years has demonstrated an increase in dust transport. Climate systems or events such as the North Atlantic Oscillation, the Indian Ocean subtropical High, Pacific Decadal Oscillation, and El Nino-Sothern Oscillation are known to influence global short-term dust dispersion occurrence and transport routes. Anthropogenic influences on dust transport include deforestation, harmful use of topsoil for agriculture as observed during the American Dust Bowl period, and the creation of dry seas (Aral Sea) and lakes (Lake Owens in California and Lake Chad in North Africa) through the diversion of source waters (for irrigation and drinking water supplies). Constituents of desert dust both from source regions (pathogenic microorganisms, organic and inorganic toxins) and those scavenged through atmospheric transport (i.e., industrial and agricultural emissions) are known to directly impact human and ecosystem health. This presentation will present a review of global scale dust storms and how these events can be both a detriment and benefit to various organisms in downwind environments.

  16. Morbidity and treatment in patients with atrial fibrillation and chronic kidney disease.

    Science.gov (United States)

    Reinecke, Holger; Nabauer, Michael; Gerth, Andrea; Limbourg, Tobias; Treszl, Andras; Engelbertz, Christiane; Eckardt, Lars; Kirchhof, Paulus; Wegscheider, Karl; Ravens, Ursula; Meinertz, Thomas; Steinbeck, Gerhard; Breithardt, Günter

    2015-01-01

    Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality but there are few studies available about atrial fibrillation, the most frequent arrhythmia in CKD, and the applied treatment. Based on the prospective German Competence NETwork on Atrial Fibrillation, data of 3138 patients with atrial fibrillation were analyzed and categorized by their estimated glomerular filtration rate (stages 1-3 and 4 plus 5). With advanced CKD, significantly more patients suffered from a more severe form of atrial fibrillation. Despite significantly higher CHADS2 scores in advanced CKD, oral anticoagulation was not prescribed more frequently while antiarrhythmic drugs and catheter ablations were used significantly less often, in contrast to more pacemaker implantations. However, in multivariate hierarchical logistic regression analyses of in-hospital treatments and complications, only hemorrhages and pacemaker implantations turned out to be independently and significantly associated with higher CKD stages. This nationwide study shows that patients with CKD and atrial fibrillation suffer from a markedly higher comorbidity. Thus, while CKD patients have received cardioversions, ablations, antiarrhythmic, or anticoagulation drugs significantly less often in their history, current treatments were not different if adjusted for multiple comorbidities. This might indicate an improvement in the often reported therapeutic nihilism in CKD. PMID:24897032

  17. Space shuttle observations of terrestrial impact structures using SIR-C and X-SAR radars

    Science.gov (United States)

    McHone, John F.; Greeley, Ronald; Williams, Kevin K.; Blumberg, Dan G.; Kuzmin, Ruslan O.

    2002-03-01

    Ten terrestrial impact structures were imaged during two flights of the 1994 Space Radar Laboratory (SRL) experiment. These craters include Wolf Creek, Australia; Roter Kamm, Namibia; Zhamanshin, Kazakhstan; B.P. and Oasis, Libya; Aorounga, Chad; Amguid, Algeria; and Spider, Connolly Basin and Henbury, Australia. SRL contained two co-registered instruments; the United States SIR-C polarimetric radar system operating in L-band (?=24 cm) and C-band (?=5.6 cm), and the joint German/Italian X-SAR vertically-polarized radar operating in X-band (?=3 cm). Comparisons show SRL images to be complementary to, or in some cases superior to, corresponding optical images for evaluating size, location, and relative age of impact features. Regardless of wavelength or polarization, craters with significant relief appear prominently on radar as a result of slope and roughness effects. In desert regions, longer wavelengths penetrate dry sand mantles to reveal hidden crater dimensions or associated buried landforms. Radar polarities and wavelengths are particularly sensitive to vegetation, surface roughness, and soil moisture or electrical properties. In the more temperate environments of Kazakhstan and Australia, SRL images show detailed stream patterns that reveal the location and structure of otherwise obscured impact features.

  18. Radar observation of Venus' terrestrial analogues using TecSAR X-band SAR

    Science.gov (United States)

    Blumberg, D. G.

    2012-04-01

    Venus is shrouded in a dense CO2 atmosphere that prevents us from viewing the surface in visible light or with optronic sensors. Long wavelengths are required to 'see' through the dense atmosphere. In the early 1990s, the S-band synthetic aperture radar of the Magellan spacecraft acquired images of a variety of surface features on Venus, including morphologies attributed to wind processes. These include sand dunes, wind-sculpted hills (yardangs), and almost 6000 wind streaks. These aeolian landscapes were formed and shaped by near surface atmospheric circulation and local winds. These can serve as local markers, each providing an integrated wind direction. Since the Magellan mission, there were no missions to Venus until the Venus Express Mission of 2005 to examine the upper atmosphere. The future will probably include high-resolution SAR images of Venus. This poster will demonstrate high resolution SAR images in X-band from the TecSAR sensor launched by Israel in 2008. Observations of wind streaks, dunes and impact craters in desert areas will show the wealth of information that is extracted from high-res X-band data. Detailed images of Aurounga impact crater in Chad, Kelso dunes, California and Pisgah lava flow show immense detail of the morphologies associated with these features. These are compared with Magellan images of sites on Venus and SRL data in C and L-bands. The X-band provides extremely high resolution and resembles optical data much more than the longer wavelengths.

  19. Wounds and weapons

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, H. [Asklepios Klinik St. Georg, Roentgenabteilung, Lohmuehlenstrasse 5, 20099 Hamburg (Germany)], E-mail: Hermann.vogel@ak-stgeorg.lbk-hh.de; Dootz, B. [Asklepios Klinik St. Georg, Roentgenabteilung, Lohmuehlenstrasse 5, 20099 Hamburg (Germany)

    2007-08-15

    Purpose: X-ray findings are described, which are typical for injuries due to conventional weapons. It is intended to demonstrate that radiographs can show findings characteristic for weapons. Material and method: The radiograms have been collected in Vietnam, Croatia, Serbia, Bosnia, Chad, Iran, Afghanistan, USA, Great Britain, France, Israel, Palestine, and Germany. Results: Radiograms of injuries due to hand grenades show their content (globes) and cover fragments. The globes are localized regionally in the victim's body. Survivors of cluster bombs show singular or few globes; having been hit by many globes would have been lethal. Shotguns produce characteristic distributions of the pallets and depth of penetration different from those of hand grenades and cluster bombs; cover fragments are lacking. Gunshot wounds (GSW) can be differentiated in those to low velocity bullets, high velocity projectiles, and projectiles, which disintegrate on impact. The radiogram furnishes the information about a dangerous shock and helps to recognize the weapon. Radiograms of victims of explosion show fragments and injuries due to the blast, information valid for therapy planning and prognosis. The radiogram shows details which can be used in therapy, forensic medicine and in war propaganda - examples could be findings typical for cluster bombs and for dumdum bullets; it shows the cruelty of the employment of weapons against humans and the conflict between the goal of medical care and those of military actions. Conclusion: Radiographs may show, which weapon has been employed; they can be read as war reports.

  20. A linear geospatial streamflow modeling system for data sparse environments

    Science.gov (United States)

    Asante, Kwabena O.; Arlan, Guleid A.; Pervez, Md Shahriar; Rowland, James

    2008-01-01

    In many river basins around the world, inaccessibility of flow data is a major obstacle to water resource studies and operational monitoring. This paper describes a geospatial streamflow modeling system which is parameterized with global terrain, soils and land cover data and run operationally with satellite‐derived precipitation and evapotranspiration datasets. Simple linear methods transfer water through the subsurface, overland and river flow phases, and the resulting flows are expressed in terms of standard deviations from mean annual flow. In sample applications, the modeling system was used to simulate flow variations in the Congo, Niger, Nile, Zambezi, Orange and Lake Chad basins between 1998 and 2005, and the resulting flows were compared with mean monthly values from the open‐access Global River Discharge Database. While the uncalibrated model cannot predict the absolute magnitude of flow, it can quantify flow anomalies in terms of relative departures from mean flow. Most of the severe flood events identified in the flow anomalies were independently verified by the Dartmouth Flood Observatory (DFO) and the Emergency Disaster Database (EM‐DAT). Despite its limitations, the modeling system is valuable for rapid characterization of the relative magnitude of flood hazards and seasonal flow changes in data sparse settings.

  1. Mineralogical, Chemical, and Optical Interrelationships of Airborne Mineral Dusts

    Science.gov (United States)

    Engelbrecht, J. P.; Moosmuller, H.; Pincock, S. L.; Jayanty, R. K. M.; Casuccio, G.

    2014-12-01

    The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The 38 μm, characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will be discussed. Differences between the clay minerals in samples from Mali and those from other localities are demonstrated. We intend establishing a data base for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and damage to equipment.

  2. Optimal Stroke Prevention in the Geriatric Patient with Atrial Fibrillation: Position Paper of an Interdisciplinary Expert Panel.

    Science.gov (United States)

    Bahrmann, P; Wehling, M; Ropers, D; Flohr, J; Leischker, A; Röther, J

    2015-10-01

    The present position paper summarises the outcomes of an expert panel discussion held by hospital-based and office-based physicians with ample experience in the treatment of geriatric patients. The optimal approach to stroke prevention in geriatric patients with atrial fibrillation (AF) has not been adequately clarified. Despite their high risk of stroke and clear indication for anticoagulation according to established risk scores, in practice geriatric AF patients often are withheld treatment because of comorbidities and comedications, concerns about low treatment adherence or fear of bleeding events, in particular due to falls. The panel agreed that geriatric patients should receive oral anticoagulation as a rule, unless a comprehensive neurological and geriatric assessment (including clinical examination, gait tests and validated instruments such as Modified Rankin Scale, Mini-mental state examination or Timed Test of Money Counting) provides sound reasons for refraining from treatment. All patients with a history of falls should be thoroughly evaluated for further evaluation of the causes. Patients with CHADS2 score ≥ 2 should receive anticoagulation even if at high risk for falls. The novel oral anticoagulants (NOAC) facilitate management in the geriatric population with AF (no INR monitoring needed, easier bridging during interventions) and have, based on available data, an improved benefit-risk ratio compared to vitamin K antagonists. Drugs with predominantly non-renal elimination are safer in geriatric patients and should be preferred. PMID:25285794

  3. Flood Inundation Mapping in the Logone Floodplain from Multi Temporal Landsat ETM+Imagery

    Science.gov (United States)

    Jung, Hahn Chul; Alsdorf, Douglas E.; Moritz, Mark; Lee, Hyongki; Vassolo, Sara

    2011-01-01

    Yearly flooding in the Logone floodplain makes an impact on agricultural, pastoral, and fishery systems in the Lake Chad Basin. Since the flooding extent and depth are highly variable, flood inundation mapping helps us make better use of water resources and prevent flood hazards in the Logone floodplain. The flood maps are generated from 33 multi temporal Landsat Enhanced Thematic Mapper Plus (ETM+) during three years 2006 to 2008. Flooded area is classified using a short-wave infrared band whereas open water is classified by Iterative Self-organizing Data Analysis (ISODATA) clustering. The maximum flooding extent in the study area increases up to approximately 5.8K km2 in late October 2008. The study also provides strong correlation of the flooding extents with water height variations in both the floodplain and the river based on a second polynomial regression model. The water heights are from ENIVSAT altimetry in the floodplain and gauge measurements in the river. Coefficients of determination between flooding extents and water height variations are greater than 0.91 with 4 to 36 days in phase lag. Floodwater drains back to the river and to the northeast during the recession period in December and January. The study supports understanding of the Logone floodplain dynamics in detail of spatial pattern and size of the flooding extent and assists the flood monitoring and prediction systems in the catchment.

  4. Safety of atrial fibrillation ablation with novel multi-electrode array catheters on uninterrupted anticoagulation-a single-center experience.

    LENUS (Irish Health Repository)

    Hayes, Christopher Ruslan

    2012-02-01

    INTRODUCTION: A recent single-center report indicated that the performance of atrial fibrillation ablation in patients on uninterrupted warfarin using a conventional deflectable tip electrode ablation catheter may be as safe as periprocedural discontinuation of warfarin and bridging with heparin. Novel multi-electrode array catheters for atrial fibrillation ablation are currently undergoing clinical evaluation. While offering the possibility of more rapid atrial fibrillation ablation, they are stiffer and necessitate the deployment of larger deflectable transseptal sheaths, and it remains to be determined if they increase the risk of cardiac perforation and vascular injury. Such potential risks would have implications for a strategy of uninterrupted periprocedural anticoagulation. METHOD AND RESULTS: We audited the safety outcomes of our atrial fibrillation ablation procedures using multi-electrode array ablation catheters in patients on uninterrupted warfarin (CHADS2 score>or=2) and in patients not on warfarin (uninterrupted aspirin). Two bleeding complications occurred in 49 patients on uninterrupted warfarin, both of which were managed successfully without longterm sequelae, and no bleeding complication occurred in 32 patients not on warfarin (uninterrupted aspirin). There were no thromboembolic events or other complication with either anticoagulant regimen. CONCLUSION: Despite the larger diameter and increased stiffness of multi-electrode array catheters and their deflectable transseptal sheaths, their use for catheter ablation in patients with atrial fibrillation on uninterrupted warfarin in this single-center experience does not appear to be unsafe, and thus, an adequately powered multicenter prospective randomized controlled trial should be considered.

  5. Diagnostic sérologique des isolats soudano-sahéliens du virus de la panachure jaune du riz (Rice Yellow Mottle Virus, RYMV

    Directory of Open Access Journals (Sweden)

    Konaté, G.

    2008-01-01

    Full Text Available Serological Diagnosis of Sudano-Sahelian Isolates of Rice Yellow Mottle Virus (RYMV. Rice Yellow Mottle Virus (RYMV is the most damaging virus infecting rice in Africa. Serology is a suitable detection method for RYMV but most available anti-RYMV polyclonal antibodies react poorly with some isolates of the virus, which undermine the reliability of the method. A broad-spectrum polyclonal antibody was raised against Rice Yellow Mottle Virus (RYMV in order to improve the serological detection of the virus. This antibody was used to diagnose the virus in field samples collected from both irrigated and upland rice and wild host plants in five West and Central African countries (Burkina Faso, Cameroon, Chad, Mali and Togo. RYMV was readily detected in about 500 samples whereas a new natural host species (Eragrostis atrovirens collected from Mali was identified. The viral isolates gathered in this study constitute the starting point for a reference collection of plant viruses in the Sudano-Sahelian region. This collection will be particularly useful for the assessment of RYMV variability which is a key factor in developing rice varieties with stable resistance to the virus.

  6. Enhancing immunogenicity and transmission-blocking activity of malaria vaccines by fusing Pfs25 to IMX313 multimerization technology.

    Science.gov (United States)

    Li, Yuanyuan; Leneghan, Darren B; Miura, Kazutoyo; Nikolaeva, Daria; Brian, Iona J; Dicks, Matthew D J; Fyfe, Alex J; Zakutansky, Sarah E; de Cassan, Simone; Long, Carole A; Draper, Simon J; Hill, Adrian V S; Hill, Fergal; Biswas, Sumi

    2016-01-01

    Transmission-blocking vaccines (TBV) target the sexual-stages of the malaria parasite in the mosquito midgut and are widely considered to be an essential tool for malaria elimination. High-titer functional antibodies are required against target antigens to achieve effective transmission-blocking activity. We have fused Pfs25, the leading malaria TBV candidate antigen to IMX313, a molecular adjuvant and expressed it both in ChAd63 and MVA viral vectors and as a secreted protein-nanoparticle. Pfs25-IMX313 expressed from viral vectors or as a protein-nanoparticle is significantly more immunogenic and gives significantly better transmission-reducing activity than monomeric Pfs25. In addition, we demonstrate that the Pfs25-IMX313 protein-nanoparticle leads to a qualitatively improved antibody response in comparison to soluble Pfs25, as well as to significantly higher germinal centre (GC) responses. These results demonstrate that antigen multimerization using IMX313 is a very promising strategy to enhance antibody responses against Pfs25, and that Pfs25-IMX313 is a highly promising TBV candidate vaccine. PMID:26743316

  7. Riparian ecosystem resilience and livelihood strategies under test: lessons from Lake Chilwa in Malawi and other lakes in Africa.

    Science.gov (United States)

    Kafumbata, Dalitso; Jamu, Daniel; Chiotha, Sosten

    2014-04-01

    This paper reviews the importance of African lakes and their management challenges. African inland lakes contribute significantly to food security, livelihoods and national economies through direct exploitation of fisheries, water resources for irrigation and hydropower generation. Because of these key contributions, the ecosystem services provided are under significant stress mainly owing to high demand by increasing populations, negative anthropogenic impacts on lake catchments and high levels of poverty which result in unsustainable use. Climate variability exacerbates the stress on these ecosystems. Current research findings show that the lakes cannot sustain further development activities on the scale seen over the past few decades. Millions of people are at risk of losing livelihoods through impacts on livestock and wildlife. The review further shows that the problems facing these lakes are beyond the purview of current management practices. A much better understanding of the interactions and feedbacks between different components of the lake socio-ecological systems is needed to address the complex challenges of managing these ecosystem services. This review suggests that the three small wetlands of Chad, Chilwa and Naivasha provide an opportunity for testing novel ideas that integrate sustainability of natural resource management with livelihoods in order to inform policy on how future land use and climatic variability will affect both food security and the ecosystem services associated with it. PMID:24535395

  8. The Weight of Health Expenditures on Household Income in Cameroon

    Directory of Open Access Journals (Sweden)

    Joseph Parfait OWOUNDI

    2014-02-01

    Full Text Available  African leaders pledged at the Abuja conference in 2001, to mobilize more financial resources to allocate at least 15% of their national budgets to the health sector to achieve the Millennium Development Goals (MDGs, seem to have difficulty meeting this commitment because of weakness and fragmentation of health systems. These commitments were renewed in Gaborone, Botswana in 2005 and in Ouagadougou, Burkina Faso in 2006. Indeed, donor funding is still a large part of public health spending on the continent. In some countries, 50% or more of their budgets come from foreign or private assistance. In about half the countries, the private health financing is equal to or exceeds largely public funding, up to 70% in some states like Sudan, Côte d'Ivoire, Cameroon, Chad, Liberia and Uganda. Only five countries (Rwanda, Malawi, Zambia, Burkina Faso, and Togo have so far respected the promise made to the Abuja conference. In Cameroon, where 51% of the population lives on less than two dollars per day, the average propensity of the total medical consumption is very high. Indeed, 32% of households spend less than half of income on health, while 16% of households spend more than half of the income and 52% spend more than the total income. This corresponds to a weight of 68% in health care spending.  

  9. Utilization and Predictors of Electrical Cardioversion in Patients Hospitalized for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Yogita M. Rochlani

    2016-01-01

    Full Text Available Atrial fibrillation (AF is a common arrhythmia in adults associated with thromboembolic complications. External electrical cardioversion (DCCV is a safe procedure used to convert AF to normal sinus rhythm. We sought to study factors that affect utilization of DCCV in hospitalized patients with AF. The study sample was drawn from the Nationwide Inpatient Sample (NIS of the Healthcare Cost and Utilization Project in the United States. Patients with a primary discharge diagnosis of AF that received DCCV during hospitalization in the years 2000–2010 were included. An estimated 2,810,530 patients with a primary diagnosis of AF were hospitalized between 2001 and 2010, of which 1,19,840 (4.26% received DCCV. The likelihood of receiving DCCV was higher in patients who were males, whites, privately insured, and aged < 40 years and those with fewer comorbid conditions. Higher CHADS2 score was found to have an inverse association with DCCV use. In-hospital stroke, in-hospital mortality, length of stay, and cost for hospitalization were significantly lower for patients undergoing DCCV during AF related hospitalization. Further research is required to study the contribution of other disease and patient related factors affecting the use of this procedure as well as postprocedure outcomes.

  10. Interactions and Feedbacks Between Biomass Burning and Water Cycle Dynamics Across the Northern Sub-Saharan African Region

    Science.gov (United States)

    Ichoku, Charles

    2012-01-01

    The northern sub-Saharan African (NSSA) region, bounded on the north and south by the Sahara and the Equator, respectively, and stretching from the West to the East African coastlines, has one of the highest biomass-burning rates per unit land area among all regions of the world. Because of the high concentration and frequency of fires in this region, with the associated abundance of heat release and gaseous and particulate smoke emissions, biomass-burning activity is believed to be one of the drivers of the regional carbon and energy cycles, with serious implications for the water cycle. A new interdisciplinary research effort sponsored by NASA is presently being focused on the NSSA region, to better understand the possible connection between the intense biomass burning observed from satellite year after year across the region and the rapid depletion of the regional water resources, as exemplified by the dramatic drying of Lake Chad. A combination of remote sensing and modeling approaches is being utilized in investigating multiple regional surface, atmospheric, and water-cycle processes, and inferring possible links between them. In this presentation, we will discuss preliminary results as well as the path toward improved understanding of the interrelationships and feedbacks between the biomass burning and the environmental change dynamics in the NSSA region.

  11. Regional view of a Trans-African Drainage System

    Directory of Open Access Journals (Sweden)

    Mohamed Abdelkareem

    2015-05-01

    Full Text Available Despite the arid to hyperarid climate of the Great Sahara of North Africa, pluvial climates dominated the region. Radar data shed some light on the postulated Trans-African Drainage System and its relationship to active and inactive tributaries of the Nile basin. Interpretations of recent elevation data confirm a source of the river water from the Red Sea highlands did not connect the Atlantic Ocean across Tushka basin, highlands of Uwinate and Darfur, and Chad basin, but northward to the ancestral Nile Delta. Elements of topography and climate were considered. They show that the former segments of the Nile closely mirror present-day tributaries of the Nile basin in drainage geometry, landscape, and climate. A rainfall data interpolation scenario revealed that this basin received concurrent runoff from both flanks such as Gabgaba-Allaqi to the east and Tushka basin to the west, similar to present-day Sobat and White Nile tributaries, respectively. Overall the western tributaries such as those of Tushka basin and Howar lead to the Nile, which was (and still is the biggest river system in Africa.

  12. 两大巨头的“握手”

    Institute of Scientific and Technical Information of China (English)

    赵丽娜(编译)

    2006-01-01

    2006年10月9日,Google的创始人Larry Page和Sergey Brin宣布耗资16.5亿美元购买YouTube的计划。You Tube是由Chad Hurley和Steve Chen创办的,Page和Brin先生凭借其搜索引擎巨头的实力制造了一种网络现象——Google用实际行动证明搜寻服务可以通过附加广告挣钱.从而对传统的网络智慧和盈利方式提出了挑战。在过去的几年内Hurley和Chert也开创了一个新的网络模式:一个简单的娱乐网址,任何人都可以下载视频片断,并分享它。

  13. Exporting expertise : Pajak Engineering sends its oilfield consultants to the farthest corners of the global patch

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, M.

    2010-06-15

    This article discussed the activities of Pajak Engineering Ltd., a Canadian company that supplies wellsite supervisors, engineers, and engineering technologists to an international client base. The company has expertise in all phases of the oil and gas production cycle, and was recently involved in evacuating Chinese and Canadian oilfield personnel from a site in Chad that was in danger of being attacked by rebel forces. A Pajak consultant persuaded officials in Cameroon to allow the 115 Chinese oilfield workers to enter the country without conventional documents. The firm was founded in 1966, and was responsible for initiating Canada's first well control training course. The firm is now concentrating on deploying more personnel internationally in order to counter the cyclical nature of the Canadian oil industry. International producers acknowledge that Canada's harsh operating environment has resulted in significant advances in drilling management technology. Pajak consultants are instructed to avoid potentially dangerous operational shortcuts, and the firm has developed a reputation for having high professional standards. 3 figs.

  14. Duloxetine in the treatment of generalized anxiety disorder

    Directory of Open Access Journals (Sweden)

    Alan Wright

    2009-08-01

    Full Text Available Alan Wright, Chad VanDenBergCenter for Clinical Research, Mercer University, Atlanta, GA, USAAbstract: Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI which is FDA approved for the treatment of generalized anxiety disorder (GAD in doses of 30 mg to 120 mg daily. Duloxetine has been shown to significantly improve symptoms of GAD as measured through the Hamilton Anxiety Rating Scale (HAMA, the Clinical Global Impressions Scale (CGI-I, and other various outcome measures in several placebo-controlled, randomized, double blind, multi-center studies. Symptom improvement began within the first few weeks, and continued for the duration of the studies. In addition, duloxetine has also been shown to improve outcomes in elderly patients with GAD, and in GAD patients with clinically significant pain symptoms. Duloxetine was noninferior compared with venlafaxine XR. Duloxetine was found to have a good tolerability profile which was predictable and similar to another SNRI, venlafaxine. Adverse events (AEs such as nausea, constipation, dry mouth, and insomnia were mild and transient, and occurred at relatively low rates. It was found to have a low frequency of drug interactions. In conclusion, duloxetine, a selective inhibitor for the serotonin and norepinephrine transporters, is efficacious in the treatment of GAD, and has a predictable tolerability profile, with AEs generally being mild to moderate.Keywords: duloxetine, generalized anxiety disorder, anxiety, GAD

  15. Duloxetine in the treatment of chronic pain due to fibromyalgia and diabetic neuropathy

    Directory of Open Access Journals (Sweden)

    Alan Wright

    2010-12-01

    Full Text Available Alan Wright, Kyle E Luedtke, Chad VanDenBergCenter for Clinical Research, Mercer University, Atlanta, Georgia, USAAbstract: Duloxetine is a serotonin-norepinephrine reuptake inhibitor approved by the US Food and Drug Administration for the treatment of fibromyalgia and painful diabetic neuropathy at doses of 60 mg daily. Duloxetine has been shown to significantly improve the symptoms of chronic pain associated with these disorders, as measured by the Fibromyalgia Impact Questionnaire, Brief Pain Inventory scores, the Clinical Global Impressions Scale, and other various outcome measures in several placebo-controlled, randomized, double-blind, multicenter studies. Symptom improvement generally began within the first few weeks, and continued for the duration of the study. In addition, the efficacy of duloxetine was found to be due to direct effects on pain symptoms rather than secondary to improvements in depression or anxiety. Adverse events including nausea, constipation, dry mouth, and insomnia, were mild and transient and occurred at relatively low rates. In conclusion, duloxetine, a selective inhibitor for the serotonin and norepinephrine transporters, is efficacious in the treatment of chronic pain associated with fibromyalgia or diabetic neuropathy, and has a predictable tolerability profile, with adverse events generally being mild to moderate.Keywords: duloxetine, chronic pain, neuropathic pain, fibromyalgia, efficacy, safety

  16. Wounds and weapons

    International Nuclear Information System (INIS)

    Purpose: X-ray findings are described, which are typical for injuries due to conventional weapons. It is intended to demonstrate that radiographs can show findings characteristic for weapons. Material and method: The radiograms have been collected in Vietnam, Croatia, Serbia, Bosnia, Chad, Iran, Afghanistan, USA, Great Britain, France, Israel, Palestine, and Germany. Results: Radiograms of injuries due to hand grenades show their content (globes) and cover fragments. The globes are localized regionally in the victim's body. Survivors of cluster bombs show singular or few globes; having been hit by many globes would have been lethal. Shotguns produce characteristic distributions of the pallets and depth of penetration different from those of hand grenades and cluster bombs; cover fragments are lacking. Gunshot wounds (GSW) can be differentiated in those to low velocity bullets, high velocity projectiles, and projectiles, which disintegrate on impact. The radiogram furnishes the information about a dangerous shock and helps to recognize the weapon. Radiograms of victims of explosion show fragments and injuries due to the blast, information valid for therapy planning and prognosis. The radiogram shows details which can be used in therapy, forensic medicine and in war propaganda - examples could be findings typical for cluster bombs and for dumdum bullets; it shows the cruelty of the employment of weapons against humans and the conflict between the goal of medical care and those of military actions. Conclusion: Radiographs may show, which weapon has been employed; they can be read as war reports

  17. Nanotechnology Research Directions for Societal Needs in 2020 Retrospective and Outlook

    CERN Document Server

    Roco, Mihail C; Mirkin, Chad A

    2011-01-01

    This volume presents a comprehensive perspective on the global scientific, technological, and societal impact of nanotechnology since 2000, and explores the opportunities and research directions in the next decade to 2020.  The vision for the future of nanotechnology presented here draws on scientific insights from U.S. experts in the field, examinations of lessons learned, and international perspectives shared by participants from 35 countries in a series of high-level workshops organized by Mike Roco of the National Science Foundation (NSF), along with a team of American co-hosts that includes Chad Mirkin, Mark Hersam, Evelyn Hu, and several other eminent U.S. scientists.  The study performed in support of the U.S. National Nanotechnology Initiative (NNI) aims to redefine the R&D goals for nanoscale science and engineering integration and to establish nanotechnology as a general-purpose technology in the next decade. It intends to provide decision makers in academia, industry, and government with a n...

  18. Electricity privatizations in Sahel: A U-turn?

    International Nuclear Information System (INIS)

    This paper examines the process of privatization of electrical utilities for the country members of CILLS (Burkina Faso, Cape Verde, The Gambia, Guinea-Bissau, Mali, Mauritania, Niger, Chad and Senegal). These Sahelian countries, the majority of whom rank at the bottom positions of the HDI and present extremely low access rates to modern energy services, together started a process of energy sector reform and energy utility privatization in the 1990s. The reforms, endorsed by the International Financial Institutions, focused on the privatization of the electrical utilities, and encountered many difficulties. The objective of this article is to analyze what happened in each of these nine countries and to understand the reasons that led to a general halt or reversal of the process. The analysis is first introduced by a brief examination of regional energy situations and of the international context in which the reforms took place; this includes the policy guidelines introduced by the IFIs and the investment decisions of energy corporations. We analyze management processes and ownership changes for each country. Finally, the article identifies the problems encountered as a result of reform design and the interaction of behaviors between the governments, the International Corporations and the IFIs; lastly, we draw conclusions.

  19. Duloxetine for the management of fibromyalgia syndrome

    Directory of Open Access Journals (Sweden)

    Beth A Scholz

    2009-07-01

    Full Text Available Beth A Scholz, Cara L Hammonds, Chad S BoomershineDepartment of Medicine, Vanderbilt University, Nashville, TN, USAAbstract: Fibromyalgia syndrome (FMS is a widespread pain condition associated with a wide range of additional symptoms including fatigue, insomnia, depression, anxiety and stiffness. Duloxetine is one of three medications currently FDA approved for use in FMS management. Duloxetine is a mixed serotonin and norepinephrine reuptake inhibitor (SNRI that functions by increasing central nervous system levels of serotonin and norepinephrine. This review is a primer on use of duloxetine in FMS management and includes information on pharmacology and pharmacokinetics, a review of the three duloxetine FMS treatment trials currently in publication, a discussion of the safety and tolerability of duloxetine, and patient-focused perspectives on duloxetine use in FMS management. Duloxetine has proven efficacy in managing pain and mood symptoms in adult FMS patients with and without major depressive disorder. However, due to side effects, duloxetine must be used with caution in patients with fatigue, insomnia, gastrointestinal complaints, headache, cardiovascular disease, bleeding-risk, and in those 24 years of age and younger due to risk of suicidality. Duloxetine use should be avoided in patients with liver disease or alcoholics. As with all medications, duloxetine is best used as part of an individualized regimen that includes nonpharmacologic modalities of exercise, education and behavioral therapies.Keywords: fibromyalgia, duloxetine, SNRI, safety

  20. Tropical Africa: Land Use, Biomass, and Carbon Estimates for 1980 (NDP-055)

    Energy Technology Data Exchange (ETDEWEB)

    Brown, S.

    2002-04-16

    This document describes the contents of a digital database containing maximum potential aboveground biomass, land use, and estimated biomass and carbon data for 1980. The biomass data and carbon estimates are associated with woody vegetation in Tropical Africa. These data were collected to reduce the uncertainty associated with estimating historical releases of carbon from land use change. Tropical Africa is defined here as encompassing 22.7 x 10{sup 6} km{sup 2} of the earth's land surface and is comprised of countries that are located in tropical Africa (Angola, Botswana, Burundi, Cameroon, Cape Verde, Central African Republic, Chad, Congo, Benin, Equatorial Guinea, Ethiopia, Djibouti, Gabon, Gambia, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Madagascar, Malawi, Mali, Mauritania, Mozambique, Namibia, Niger, Nigeria, Guinea-Bissau, Zimbabwe (Rhodesia), Rwanda, Senegal, Sierra Leone, Somalia, Sudan, Tanzania, Togo, Uganda, Burkina Faso (Upper Volta), Zaire, and Zambia). The database was developed using the GRID module in the ARC/INFO{trademark} geographic information system. Source data were obtained from the Food and Agriculture Organization (FAO), the U.S. National Geophysical Data Center, and a limited number of biomass-carbon density case studies. These data were used to derive the maximum potential and actual (ca. 1980) aboveground biomass values at regional and country levels. The land-use data provided were derived from a vegetation map originally produced for the FAO by the International Institute of Vegetation Mapping, Toulouse, France.

  1. Desertification, refugees and regional conflict in west Africa.

    Science.gov (United States)

    Nnoli, O

    1990-06-01

    This article documents the potential for inter-state conflict in the migration of hundreds of thousands of famine refugees across international borders in West Africa. Nigeria and Ghana, for example, have to deal not only with the effects of land degradation in their northern territories but also with the influx of famine victims from Mali, Niger, Chad and Burkino Faso. These migrations put an enormous extra burden on the fragile and already overstretched social and economic infrastructures of the host countries. The construction of dams for irrigation and electricity generation in international river basins, is another cause of inter-state conflict related to land degradation. The capacity of West African states to find peaceful solutions to these problems is being undermined by the increasing impoverishment and marginalisation of their populations. A self-serving neo-colonialist governing elite is caught in the economic stranglehold of the advanced capitalist nations. While there is thus no short term solution to the problem of land degradation, immediate steps should at least be taken to give legal protection to those who are forced to cross international borders because of drought and famine. PMID:20958699

  2. Enquête sérologique sur quelques maladies aviaires dans la région du Nord Guéra (Tchad

    Directory of Open Access Journals (Sweden)

    Maho, A.

    1999-01-01

    Full Text Available Serological Investigation on Five Fowl Diseases in the North Region of Guera (CHAD. A serological survey concerning five fowl diseases are carried out from three subprefectures (Mangalme, Bitkine, Mongo of the North Guera, localites situated at 550 km in the North of N'Djamena. A total of 270 chickens of approximatly 12 months old are bought which 103 around Mangalme, 93 around Mongo and 82 around Bitkine. The results show low rate of infection for Newcastle disease (7.33 %, Gumgoro disease (8.66 % and Salmmonella pullorum infection (8.73 %. Higher rates are found for infectious bronchitis (32 % and Mycoplasma synoviae infection (36.66 %. Different type (2, 3 or 5 of anti-bodies are found sometimes in the same chicken showing that several infections circulate in the same hen house. As far as the are concerned, infectious bronchitis (83 % and Mycoplasma synoviae infection (72 % have very high rate followed by pullorosis (55 %. These results prove that these diseases sometimes unkown by field veterinary agents are widespread. Any improvement fowl production need a best control of the diseases by training field veterinary agents and poultryman on prevention poultry disease.

  3. [Transmission dynamics and cost-effectiveness of rabies control in dogs and humans in an African city].

    Science.gov (United States)

    Zinsstag, J; Dürr, S; Penny, M A; Mindekem, R; Roth, F; Menendez Gonzalez, S; Naissengar, S; Hattendorf, J

    2011-12-01

    Control of human rabies in developing countries depends on prevention in dogs. The purpose of this study was to evaluate the cost-saving potential for the public health sector of intervention to control rabies in animal-host reservoirs. An existing deterministic model was adapted to allow study of dog-to-human rabies transmission. Model parameters were fitted to data from routine weekly reports on the number of rabid dogs and human rabies exposures in N'Djamena, Chad. At the onset of study, the estimated effective reproductive ratio (Re) was 1.01 indicating stable low-level endemic rabies transmission. Simulations were performed to determine what effects mass vaccination and culling of dogs would have on the incidence of human rabies. Findings showed that a mass campaign allowing single parenteral vaccination of at least 70% of the canine population would be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to that of "postexposure prophylaxis" (PEP) which would not reduce future human exposure. Results showed that a sustained 5-year PEP program together with a dog-vaccination campaign would be as cost-effective as PEP alone. Beyond a time-frame of 7 years, combining parenteral dog vaccination campaigns with human PEP appeared to be more cost-effective than human PEP alone. PMID:22393628

  4. Comparison of the Microbial Diversity and Abundance Between the Freshwater Land-Locked Lakes of Schirmacher Oasis and the Perennially Ice-Covered Lake Untersee in East Antarctica

    Science.gov (United States)

    Huang, Jonathan; Hoover, Richard B.; Swain, Ashit; Murdock, Chris; Bej, Asim K.

    2010-01-01

    Extreme conditions such as low temperature, dryness, and constant UV-radiation in terrestrial Antarctica are limiting factors of the survival of microbial populations. The objective of this study was to investigate the microbial diversity and enumeration between the open water lakes of Schirmacher Oasis and the permanently ice-covered Lake Untersee. The lakes in Schirmacher Oasis possessed abundant and diverse group of microorganisms compared to the Lake Untersee. Furthermore, the microbial diversity between two lakes in Schirmacher Oasis (Lake L27C and L47) was compared by culture-based molecular approach. It was determined that L27Chad a richer microbial diversity representing 5 different phyla and 7 different genera. In contrast L47 consisted of 4 different phyla and 6 different genera. The difference in microbial community could be due to the wide range of pH between L27C (pH 9.1) and L47 (pH 5.7). Most of the microbes isolated from these lakes consisted of adaptive biological pigmentation. Characterization of the microbial community found in the freshwater lakes of East Antarctica is important because it gives a further glimpse into the adaptation and survival strategies found in extreme conditions.

  5. Radio as the Voice of God: Peace and Tolerance Radio Programming’s Impact on Norms

    Directory of Open Access Journals (Sweden)

    Daniel P. Aldrich

    2012-12-01

    Full Text Available Observers have argued that radio programming can alter norms, especially through hate radio designed to increase animosity between groups. This article tests whether or not radio programming under the Countering Violent Extremism (CVE policy framework can reduce potential conflict and increase civic engagement and positive views of foreign nations. Data from surveys of more than 1,000 respondents in Mali, Chad, and Niger illuminate the ways in which peace and tolerance programming changed perspectives and altered behavior in statistically significant ways. Results show that individuals exposed to multi-level U.S. government programming were more likely to listen to peace and tolerance radio. Further, bivariate, multivariate regression, and propensity score matching techniques show that individuals who listened more regularly to such programs participated more frequently in civic activities and supported working with the West to combat terrorism (holding constant a number of potential confounding economic, demographic, and attitudinal factors. However, higher levels of radio listening had no measurable impact on opposition to the use of violence in the name of Islam or opposition to the imposition of Islamic law. Further, data indicate that women and men have responded to programming in measurably different ways. These mixed results have important implications for current and future “soft-side” programs for countering violent extremism.

  6. Law, Water and Sustainable Development: Framework of Nigerian Law - Country Legislation

    Directory of Open Access Journals (Sweden)

    Olawale Ajai

    2012-06-01

    Full Text Available The central issues of economic development and environmental protection in the current social, political and economic environment relate to water – an overlooked or less glamorous natural resource. For example, topical and sometimes controversial issues such as crude oil and minerals extraction, pollution control, biodiversity protection, energy and power, resource control, revenue allocation and political participation, etc., relate directly or indirectly to water resources management. This paper seeks to identify and present in a schematic and conceptual manner and to highlight the usefulness of folklore for sustainable development and evaluate the usefulness of recruiting traditional institutions into the institutional framework for modern sustainable water resources management in Nigeria It also discusses the emergent law on water resources as well as the issues concerning the domestic and international riparian law, in particular the River Niger and Lake Chad basins and explores how folklore, comparative law and international law may be adopted and adapted to aid the development and application of water law, and by direct implication sustainable development in Nigeria.

  7. Nations of the earth report

    International Nuclear Information System (INIS)

    These books contain summaries of the national reports prepared for the UN Conference on Environment and Development held in Rio de Janeiro, June 1992. Summary reports of the following countries are included: V. 1) Algeria, Argentina, Barbados, Belize, Benin, Burkina Faso, Burundi, Canada, Chad, China, Costa Rica, Cote d'Ivoire, Cyprus, Djibouti, Egypt, Fiji, Finland, France, Guinea, Jordan, Maldives, Mali, Mauritania, Mozambique, Netherlands, Niger, Nigeria, Niue, Paraguay, Romania, Senegal, Singapore, Solomon Islands, South Africa, Sri Lanka, Swaziland, Sweden, Tokelau, Turkey, Uganda, Ukraine, United Kingdom, United Republic of Tanzania, Vanuatu, Western Samoa, Yemen Arab Republic, Yugoslavia. V. 2) Afghanistan, Antigua and Barbuda, Bangladesh, Bhutan, Brazil, British Virgin Islands, Bulgaria, Central African Republic, Colombia, Czech and Slovak Federal Republic, Denmark, Dominican Republic, Equatorial Guinea, Ethiopia, Gambia, Germany, Ghana, Guinea-Bissau, Guyana, Honduras, Japan, Kenya, Republic of Korea, Lao People's Democratic Republic, Lebanon, Lesotho, Marshall Islands, Mauritius, Morocco, New Zealand, Nicaragua, Oman, Organization of Eastern Caribbean States, Pacific Islands Developing Countries, Pakistan, Philippines, Poland, Portugal, Qatar, Rwanda, Saudi Arabia, Seychelles, Sierra Leone, Spain, Sudan, Thailand, Tonga, Trinidad and Tobago, Uruguay, Zimbabwe

  8. Activities of Protection against Ionizing Radiation in Niger

    International Nuclear Information System (INIS)

    Niger, sahelian country of Western Africa, is limited to North by Libya and Algeria, to the South by Nigeria and the Benin, to the East by Chad and the West by Mali and Burkina Faso. It covers a surface of 1 267 000 km2 and has a population of approximately 12 000 000 inhabitants. Niger is a large uranium producer with two extraction and treatment development companies of uranium ore which are the company of the mines of Air (SOMAIR) created in 1971 and the mining company of Akouta (COMINAK) created in 1978. Beyond the mining sector, ionizing radiation sources are used in the fields of industry, health, teaching and research. The first lawful text of protection against ionizing radiation was signed on December 5, 1979 and specifically related to the mining activities of uranium. With the multiform assistance of International Atomic Energy Agency (IAEA) protection against radiation knew a significant evolution. A national centre of protection against radiation was created in 1998, two laws relating to the field were adopted in June 2006 and three lawful texts of application of these laws are in the process of finalization

  9. Les réfugiés dans le monde entre protection et illégalité

    Directory of Open Access Journals (Sweden)

    Olivier Clochard

    2008-02-01

    Full Text Available Les distributions spatiales des personnes en quête d’une protection dans le Monde soulignent que les pays développés reçoivent un faible nombre de demandeurs d’asile et de réfugiés. Il existe un fort déséquilibre démographique entre des États tels aujourd’hui la Syrie, le Tchad ou le Soudan et des pays développés où les requérants sont relativement peu nombreux. Par ailleurs, les réfugiés théoriquement protégés par la convention de Genève de 1951, sont de plus en plus considérés par les États européens, comme des migrants illégaux et traités comme tels.Spatial distributions of interns’ displacement people (IDP and refugees in the World underline that the developed countries receive a low number of this people. There is a strong demographic imbalance between States such today Syria, Chad or Sudan and countries developed where the applicants are relatively very few. In addition, the refugees theoretically protected by the convention of Geneva from 1951, are considered more and more by the European States, like migrants illegal and treated like such.

  10. Atrial Fibrillation and Non-cardiovascular Diseases: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Cátia Ferreira

    2015-11-01

    Full Text Available Atrial fibrillation (AF is the most common cardiac arrhythmia and is associated with an unfavorable prognosis, increasing the risk of stroke and death. Although traditionally associated with cardiovascular diseases, there is increasing evidence of high incidence of AF in patients with highly prevalent noncardiovascular diseases, such as cancer, sepsis, chronic obstructive pulmonary disease, obstructive sleep apnea and chronic kidney disease. Therefore, considerable number of patients has been affected by these comorbidities, leading to an increased risk of adverse outcomes.The authors performed a systematic review of the literature aiming to better elucidate the interaction between these conditions.Several mechanisms seem to contribute to the concomitant presence of AF and noncardiovascular diseases. Comorbidities, advanced age, autonomic dysfunction, electrolyte disturbance and inflammation are common to these conditions and may predispose to AF.The treatment of AF in these patients represents a clinical challenge, especially in terms of antithrombotic therapy, since the scores for stratification of thromboembolic risk, such as the CHADS2 and CHA2DS2VASc scores, and the scores for hemorrhagic risk, like the HAS-BLED score have limitations when applied in these conditions.The evidence in this area is still scarce and further investigations to elucidate aspects like epidemiology, pathogenesis, prevention and treatment of AF in noncardiovascular diseases are still needed.

  11. Pregabalin for the management of fibromyalgia syndrome

    Directory of Open Access Journals (Sweden)

    Chad S Boomershine

    2010-06-01

    Full Text Available Chad S BoomershineDepartment of Medicine, Vanderbilt University, Nashville, TN, USAAbstract: This last article in a three-part series on approved medications for managing fibromyalgia syndrome (FMS reviews pregabalin (Lyrica®. Pregabalin was the first drug approved for FMS management and, as an anticonvulsant, differs from the other approved agents that are antidepressants. Pregabalin inhibits presynaptic excitatory neurotransmitter release by blocking a2d calcium channels. Five randomized, placebo-controlled trials have demonstrated pregabalin reduces pain and improves sleep and health-related quality of life in FMS patients. While indicated dosing is 300–450 mg divided twice daily, initial dosing of 25–50 mg at night is recommended owing to side effects including somnolence, dizziness, and cognitive dysfunction. Since side effects such as weight gain and peripheral edema are dose-related, uptitration in weekly increments based on tolerability and therapeutic response is recommended. Due to its lack of protein binding and negligible hepatic metabolism, pregabalin can be safely combined with other medications and used in patients with renal failure when the dose is appropriate. Pregabalin may worsen sedation when combined with central nervous system depressants. Pregabalin should be discontinued gradually. Pregabalin-treated patients should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior. Pregabalin in combination with the other approved medications may be synergistic in treating FMS.Keywords: review, Lyrica®, treatment, depression

  12. Regional view of a Trans-African Drainage System.

    Science.gov (United States)

    Abdelkareem, Mohamed; El-Baz, Farouk

    2015-05-01

    Despite the arid to hyperarid climate of the Great Sahara of North Africa, pluvial climates dominated the region. Radar data shed some light on the postulated Trans-African Drainage System and its relationship to active and inactive tributaries of the Nile basin. Interpretations of recent elevation data confirm a source of the river water from the Red Sea highlands did not connect the Atlantic Ocean across Tushka basin, highlands of Uwinate and Darfur, and Chad basin, but northward to the ancestral Nile Delta. Elements of topography and climate were considered. They show that the former segments of the Nile closely mirror present-day tributaries of the Nile basin in drainage geometry, landscape, and climate. A rainfall data interpolation scenario revealed that this basin received concurrent runoff from both flanks such as Gabgaba-Allaqi to the east and Tushka basin to the west, similar to present-day Sobat and White Nile tributaries, respectively. Overall the western tributaries such as those of Tushka basin and Howar lead to the Nile, which was (and still is) the biggest river system in Africa. PMID:26257941

  13. 冥王星的抗争

    Institute of Scientific and Technical Information of China (English)

    J. Kelly Beatty; 吴之月(译)

    2008-01-01

    还记得当年天文学家认为他们已经摆平了行星资格问题吗?其实,他们错得不能再错了。都是阋神星惹的祸这颗游荡在太阳系偏远地带的天体一经发现,立即把“什么才是行星”这个争议不断的话题炒到了火烧眉毛的地步,闹得不可开交。刚被发现时,阅神星获得的临时编号为2003 UB313,很快科学家就证实这个家伙比冥王星还要大一点。是它的发现者Michael Brown、Chad Trujillo和David Rabinowitz发现了太阳系的第十颗行星?

  14. Left Atrial Appendage: Physiology, Pathology, and Role as a Therapeutic Target

    Directory of Open Access Journals (Sweden)

    Damiano Regazzoli

    2015-01-01

    Full Text Available Atrial fibrillation (AF is the most common clinically relevant cardiac arrhythmia. AF poses patients at increased risk of thromboembolism, in particular ischemic stroke. The CHADS2 and CHA2DS2-VASc scores are useful in the assessment of thromboembolic risk in nonvalvular AF and are utilized in decision-making about treatment with oral anticoagulation (OAC. However, OAC is underutilized due to poor patient compliance and contraindications, especially major bleedings. The Virchow triad synthesizes the pathogenesis of thrombogenesis in AF: endocardial dysfunction, abnormal blood stasis, and altered hemostasis. This is especially prominent in the left atrial appendage (LAA, where the low flow reaches its minimum. The LAA is the remnant of the embryonic left atrium, with a complex and variable morphology predisposing to stasis, especially during AF. In patients with nonvalvular AF, 90% of thrombi are located in the LAA. So, left atrial appendage occlusion could be an interesting and effective procedure in thromboembolism prevention in AF. After exclusion of LAA as an embolic source, the remaining risk of thromboembolism does not longer justify the use of oral anticoagulants. Various surgical and catheter-based methods have been developed to exclude the LAA. This paper reviews the physiological and pathophysiological role of the LAA and catheter-based methods of LAA exclusion.

  15. The Safety of Dabigatran Versus Warfarin in Patients Undergoing Atrial Fibrillation Ablation

    Directory of Open Access Journals (Sweden)

    Luis I. Garcia, MD; Kartikya Ahuja, MD; Mark A. Mascarenhas, MD; Anthony Aizer, MD; Neil Bernstein, MD; Scott A. Bernstein, MD; Steve J. Fowler, MD; Douglas S. Holmes, MD; David S. Park, MD; Larry Chinitz, MD

    2014-02-01

    Full Text Available The safety and optimal strategy of the use of dabigatran versus uninterrupted warfarin in atrial fibrillation ablation is currently unclear. We performed a retrospective analysis between July 2011-October 2012 of all patients undergoing an AF ablation who received uninterrupted warfarin therapy (199 and the routine cessation of Dabigatran therapy (126 4 days pre-ablation. Major safety endpoints included: pericardial effusion (requiring pericardiocentesis, peripheral thromboembolism, CVA, and groin hematoma requiring blood transfusion. Minor endpoints included pericardial effusion and groin hematoma. Dabigatran was restarted the following day after ablation. The warfarin group was older, had a higher CHADS2, CHA2DS2VASc and HASBLED scores and greater prevalence of aortic plaque. The major complication rate was 2.0% in the warfarin group and 2.4% in the dabigatran group (P= 0.83. The minor complication rate was 2.5% in the warfarin group and <1% in the dabigatran group (P= 0.27. In the dabigatran group, there was one renal thromboembolic event 4 days post-ablation. All patients in the warfarin group who suffered a major complication required a blood transfusion. Cessation of dabigatran therapy 4 days pre AF ablation has a comparable safety profile to uninterrupted warfarin therapy.

  16. A case-based approach to implementing guidelines for stroke prevention in patients with atrial fibrillation: balancing the risks and benefits.

    Science.gov (United States)

    Amin, Alpesh; Deitelzweig, Steven

    2015-01-01

    Atrial fibrillation (AF) puts patients at risk of complications, including stroke. Warfarin therapy has been the mainstay of antithrombotic treatment for reducing the risk of stroke in AF. However, warfarin has limitations that have motivated development of several novel oral anticoagulants (NOACs), including dabigatran, rivaroxaban, apixaban, and edoxaban. Clinical trials demonstrate that the NOACs offer efficacy and safety that are equivalent to, or better than, those of warfarin for reducing the risk of stroke in patients with nonvalvular AF. This review examines stroke risk reduction in patients with AF from the perspective of the clinician balancing the risks and benefits of treatment options, evaluates the most recent guidelines, and discusses 2 hypothetical patient cases to better illustrate how clinicians may apply available data in the clinical setting. We reviewed guidelines for the reduction of stroke risk in AF and data from clinical trials on the NOACs. Choosing antithrombotic treatment involves assessing the benefits of therapy versus its risks. Risk indexes, including CHADS2, CHA2DS2-VASc, and HAS-BLED can help determine how to treat patients with AF. Current guidelines suggest using these risk indexes to customize treatment to individual patients. Many current treatment guidelines also incorporate recommendations for the use of NOACs as an alternative to warfarin. As additional data emerge and guidelines are updated, these recommendations will likely evolve. In the interim, clinicians may consider published guidelines and clinical trial results on NOACs. Real-world experience will provide clinicians with additional insight into their treatment decisions. PMID:26300695

  17. New anticoagulant drugs versus warfarin in atrial fibrillation: economic evaluation and cost-effectiveness analysis

    Directory of Open Access Journals (Sweden)

    Mauro Silingardi

    2013-12-01

    Full Text Available Health care resources available for medical procedures, including pharmaceuticals, are limited worldwide. Health economic evidence is now accepted as an essential component of health technology appraisal, realizing the importance of value for money considerations for a more efficient (cost-effective prescribing. Regulatory agencies in more and more countries perform economic evaluation and cost-effectiveness analysis in order to decide about reimbursement of a new and almost always more expensive drug. Pharmacoeconomy is now acknowledged as a science. Cost-effective analysis is just one of its approaches, measuring cost in money and benefit in terms of Quality Adjusted Life Year, a new outcome measure which combines quantity/quality of additional life-years gained with the new drug/technology. A growing body of pharmacoeconomic evidence about new anticoagulant drugs (dabigatran, rivaroxaban, apixaban for stroke prevention in atrial fibrillation is now available. Most of this evidence comes from the National Institute of Health and Clinical Excellence (NICE in the United Kingdom, the most referenced regulatory agency in the world. Compared to current standard therapies (warfarin, dabigatran, rivaroxaban and apixaban are cost-effective treatments for the whole population of patients with atrial fibrillation, independently of poor/good international normalized ratio control (time in therapeutic range and risk stratification for stroke (CHADS2 score. Significant innovation and the lower rate of intracranial hemorrhage/hemorrhagic stroke coupled with the new drugs are the key drivers of these results.

  18. Astronomy in Hawai'i is Where the Ocean Meets the Mountain

    Science.gov (United States)

    Babayan, Kalepa

    2012-01-01

    For generations the starry heavens have been a constant companion to oceanic wayfinders as they navigated from island to island. As mariner explorers sailed in search of new landfalls the stars served as signposts along oceanic seaways, recording the direction to new discoveries and return pathways to the distant islands they had sailed from. Given this historical background, and a Hawaiian worldview that sees astronomy as interconnected with the ocean and the land, educators at `Imiloa Astronomy Center have created a series of educational experiences that allow learners to integrate indigenous and western paradigms. Culture and Science Integration Hawai'i (CSI Hawai'i), is an example of a uniquely Hawaiian approach to learning, that focuses on a specific cultural practice and explores common intersections with science. This paper describes CSI Hawai'i and other culturally relevant examples of education and public outreach that are successfully engaging learners in astronomy, in addition to language, culture, and sustainable environmental practices. Presented by master navigator Kalepa Chad Baybayan, this session will include demonstrations and video footage of how navigators use derive clues about position, direction, and distance come from the stars, sun, and moon; from currents, ocean swells, and localized wave characteristics.

  19. Farm Organization, Ownership and Food Productivity in Nigeria

    Directory of Open Access Journals (Sweden)

    Nkasiobi Silas Oguzor

    2012-06-01

    Full Text Available African food production is in crisis. Today, despite Africa’s vast physical and climatic potentials to produce food, most African States depend on food importation. Africa’s capacity to deal with its food battles is severely constrained by its political instability, its early stage of scientific and institutional development, and a rapidly changing and complex global environment. In Nigeria and in most developing economies, there is a fundamental lack of political commitment to come grips with poverty, malnutrition and access to food. Because of these barriers, traditional economics is a rather limited tool to understand food production and other related variables. Poverty, hunger, malnutrition, famine and starvation in developing economies are just as much a function of political, macroeconomic, and institutional barriers as lack of technology. Illustrations from the agrarian chaos in Sudan, Ethiopia, Somalia, Chad and others are too numerous to conclude otherwise. The aim of this paper is to determine and analyze economics incentives and strategies, which could stimulate commercial agriculture in Nigeria. The analysis is based on the premise that the form of production organization in Nigerian agriculture is the major constraint to commercialization. The paper concludes that output price subsidy is the over-riding factor in the commercialization of agriculture in Nigeria.

  20. A Case—Contrl Study of Dietary Factors in Patients with Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    HUANGCHENGYU; ZHANGXIUQUAN; 等

    1992-01-01

    A case-control study was designed to investigate association of dietary factors with the risk of lung cancer in Sichuan,China.The cases consisted of 135 patients with preinvasive lung cancer which had been confirmed with histopathology,fiber bronchoscope,CT and X-ray film in three provincial hospitals in the recent one year.Controls were healthy subjects who went to one of these hospitals for health check-up;patients with pulmonary diseases was exluded.Controls were matched to cases for sex and age with a ratio of 1:1.Nutrient intakes, the eating habit and other relevant factors were investigated.The data analyzed with the conditional logistic regression model indicated,that dietary beta-carotene intakes had a significantly inverse association with the risk of lung cancer.Vitamin Chad a less significantly inverse association with the risk.Association of protein,fat,energy,retinol intakes of dietbalance index with the risk was not significant.Association of tea,alcohol,garlic or mushroom,respectively,with the risk was also not observed.Consumption of more processed foods and deep-fried foods were found to be risk factors.Smoking and air pollution from coal burning stoves were also observed as independent risk factors of lung cancer in the present study.The mental stress incidence in the case was significantly higher than that in the control.

  1. Sur Sudán: dinámicas, incertidumbres y amenazas en la actual posguerra | Southern Sudan: dynamics, uncertainties and threats in the ongoing post-war era

    Directory of Open Access Journals (Sweden)

    Óscar MATEOS

    2007-10-01

    Full Text Available Los conflictos al sur de Sudán, desde 1956, han sido tan cruentos como malinterpretados desde el exterior. El actual proceso posbélico, después de los acuerdos de 2005 (Comprehensive Peace Agreement, está estancado entre la política inmovilista de Jartum y las divisiones entre los diversos grupos étnicos y religiosos que están detrás de los movimientos opositores. Paradigma de los conflictos africanos postcoloniales (y de las contradicciones del Estado-nación heredado de la colonización occidental, las “guerras sudanesas” parecen hallarse en un momento de impasse cuyas consecuencias son imprevisibles. Las dudas sobre el DDR en el sur (Desarme, Desmovilización y Reinserción pasan por la propia inestabilidad interna en el este (Darfur y regional (Chad, R.D. Congo, R. Centroafricana. El artículo profundiza en las dinámicas políticas, económicas, sociológicas e históricas (dinámicas políticas “norte-sur” y “sur-sur” del Sudán precolonial y colonial que configuran un escenario tan complejo.   Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:12.0pt; mso-para-margin-left:0cm; text-align:justify; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Conflicts in southern Sudan, since 1956, have been as bloody as misinterpreted by international actors. The current post-war process, after the agreements reached in 2005 (Comprehensive Peace

  2. Fish as a proxy for African paleogeography: results from both extant and fossil taxa and prospects to constrain faunal exchange pathway through time

    Science.gov (United States)

    Otero, Olga; Joordens, Josephine; Dettai, Agnès; Christ, Leemans; Pinton, Aurélie

    2016-04-01

    reveal ancient distributions. The further we are going back in time the more they will constitute most of or the whole relevant sample. Our results also suggest that information on the (paleo)ecology of the fish provides useful data notably to qualify the aquatic systems that have prevailed at the time of connection between basins. So, changes in basin geomorphology constrain fish evolution, and thus we are able to reconstruct and date these changes thanks to fish evolution studies. Since it is widely agreed that the identification of corridors and barriers is critical to understand faunal exchange, we are convinced that for each case study, we can identify the fish (either fossil or extant) that will provide a relevant "geomorphological model". To validate this approach, our current project aims to identify the exchange corridor that may have intermittently existed between the Chad and Turkana basins during the last 3 million years [6]. These corridors may have constituted possible pathways for interbasinal exchange of large mammals at a key time period of Australopithecine evolution. We will end our presentation with preliminary results concerning phylogeography of the extant catfish Synodontis schall, one of our three model species. [1] Pinton A., Otero O. in progress - How much do fish distribution depend on drainage system history? the case study of continental Africa. [2] Pinton A., Agnèse J.F., Paugy D., Otero O. 2013 - A large-scale phylogeny of Synodontis (Mochokidae, Siluriformes) reveals the influence of geological events on continental diversity during the Cenozoic. Molecular Phylogenetics and Evolution, 66 (2013): 1027-1040. [3] Otero O. 2011 - Current knowledge and new assumptions on the evolutionary history of the African lungfish, Protopterus, based on a review of its fossil record. Fish & Fisheries, 2011(12): 235-255. [4] Otero O., Pinton A., Mackaye H.T., Likius A., Vignaud P., Brunet M. 2009 - Fishes and palaeogeography of the African drainage basins

  3. Cost-effectiveness of edoxaban versus rivaroxaban for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF in the US

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    Miller JD

    2016-05-01

    Full Text Available Jeffrey D Miller,1 Xin Ye,2 Gregory M Lenhart,1 Amanda M Farr,1 Oth V Tran,1 W Jackie Kwong,2 Elizabeth A Magnuson,3 William S Weintraub41Truven Health Analytics Inc, Cambridge, MA, 2Daiichi Sankyo Inc, Parsippany, NJ, 3St Luke Mid-America Heart Institute, Kansas City, MO, 4Center for Heart and Vascular Health, Christiana Care Health System, Newark, DE, USABackground: Understanding the value of new anticoagulation therapies compared with existing therapies is of paramount importance in today’s cost-conscious and efficiency-driven health care environment. Edoxaban and rivaroxaban for stroke prevention in nonvalvular atrial fibrillation (NVAF patients with CHADS2 scores ≥2 have been evaluated in pivotal trials versus warfarin. The relative value of edoxaban versus rivaroxaban would be of interest to health care stakeholders and patients who prefer a once-daily treatment option for long-term stroke prevention in NVAF.Objective: To evaluate the relative cost-effectiveness of two once-daily regimens of novel oral anticoagulation therapy – edoxaban (60 mg/30 mg dose-reduced versus rivaroxaban (20 mg/15 mg dose-reduced – for stroke prevention in NVAF patients from a US health-plan perspective.Materials and methods: A Markov model simulated lifetime risk and treatment of stroke, systemic embolism, major bleeding, clinically relevant nonmajor bleeding, myocardial infarction, and death in NVAF patients treated with edoxaban or rivaroxaban. Efficacy and safety data were derived from a network meta-analysis that utilized data from patients enrolled in ENGAGE AF-TIMI 48 and ROCKET-AF. Health care cost and utility data were obtained from published sources. Incremental cost-effectiveness ratios of $150,000 per quality-adjusted life year (QALY gained were used as thresholds for “highly cost-effective”, “cost-effective”, and “not cost-effective” treatment options, respectively, as per American Heart Association/American College of Cardiology

  4. Quality of life, activity impairment, and healthcare resource utilization associated with atrial fibrillation in the US National Health and Wellness Survey.

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    Amir Goren

    Full Text Available OBJECTIVES: This study builds upon current studies of atrial fibrillation (AF and health outcomes by examining more comprehensively the humanistic burden of illness (quality of life, activity impairment, and healthcare resource utilization among adult patients with AF, using a large, nationally representative sample and matched controls. METHODS: Data were analyzed from the Internet-based 2009 US National Health and Wellness Survey. Outcomes were Mental and Physical Component Summary (MCS and PCS and health utility scores from the SF-12, activity impairment, hospitalizations, and healthcare provider and emergency room (ER visits. Patients with self-reported diagnosis of AF were matched randomly on age and gender with an equal number of respondents without AF. Generalized linear models examined outcomes as a function of AF vs. non-AF status, controlling for CHADS2 score, comorbidity counts, demographics, and clinical variables. Exploratory structural equation modeling assessed the above in an integrated model of humanistic burden. RESULTS: Mean age of AF patients (1,296 from a total sample of 75,000 was 64.9 years and 65.1% were male. Adjusting for covariates, compared with non-AF patients, AF patients had lower MCS, PCS, and utility scores, greater activity impairment (rate ratio = 1.26, more traditional provider visits (rate ratio = 1.43, and increased odds of ER visits (OR = 2.53 and hospitalizations (OR = 2.71. Exploratory structural equation modeling analyses revealed that persons with AF experienced a significantly higher overall humanistic burden. CONCLUSIONS: This study highlights and clarifies the substantial burden of AF and its implications for preparing efficacious AF management plans to address the imminent rise in prevalence.

  5. Editorial.

    Science.gov (United States)

    O'connell, H

    1993-06-01

    Human rights groups have traditionally monitored and publicized human rights abuses suffered mainly by men (e.g., torture, killings, and imprisonment) and have ignored abuses of women. Gender-sensitive research and women's groups have uncovered this oversight. Rape in the former Yugoslavia is now considered a war crime, requiring full investigation and punishment. Conflict and violence affect women in several ways related specifically to the gender division of rights, responsibilities, and roles. Class and ethnic differences conceal this gender related experience, however. Even in countries sympathetic to women's equality, women still are second class citizens. Women are always conscious of the ever-present threat or experience of physical and sexual violence, almost always inflicted by men. Perpetrators use violence to keep women down; to restrict opportunities for them to live, learn, work, and care a full human beings; to impede their potential to organize and demand their rights. Domestic violence against women occurs across all social groups, races, age groups, and religious and political persuasions. Violence against females begins before birth. Forced prostitution violates women's human rights. Patriarchy supports discriminatory treatment and backs violence as a legitimate means to preserve the status quo. Was has had a gender-related effect on women in Afghanistan, Chad, and Cambodia. The psychological and social impact of conflict (e.g., state-sponsored terrorism) on women is also examined. Physical ailments are often manifestations of psychological disorders. Common themes are women's increased vulnerability to rape and sexual abuse during conflict, rapid rise in the numbers of households dependent on women's labor, placing on them an excessive burden, and complete disruption of economic and social life. Further, this disruption provides opportunities for women to overcome some aspects of their traditional roles. More than 80% of the world's refugees are

  6. The benefits of ‘One Health’ for pastoralists in Africa

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    Helena Greter

    2014-04-01

    Full Text Available ‘One health’ is particularly suited to serve mobile pastoralists. Dinka pastoralists in Sudan inspired Calvin Schwabe to coin the term ‘one medicine’, indicating that there is no difference in paradigm between human and veterinary medicine. Our contemporary definition of ‘one health’ is any added value in terms of improved health of humans and animals or financial savings or environmental services resulting from a closer cooperation of human and animal health sectors. Here we present a summary of ‘one health’ studies with mobile pastoralists in Africa which were done in research partnership, demonstrating such an added value. Initial joint human and animal health studies revealed higher livestock vaccination coverage than in the pastoralist community, leading to joint animal and human vaccination intervention studies which demonstrated a better access to primary health care services for pastoralists in Chad. Further simultaneous animal and human serological studies showed that camel breeding was associated with human Q-fever seropositivity. In Borana communities in Ethiopia, human cases of  Mycobacterium bovis infection could be related to strains isolated from cattle. A challenge remained with regard to how to assess vaccination coverage in mobile populations. With the advent of mobile phones, health and demographic surveillance could be established for mobile pastoralists and their animals. This presents vast possibilities for surveillance and control of human and animal diseases. Pastoralists prefer a ‘one health’ approach and therefore contribute toward the validation of this concept by showing real added value of the cooperation between human and animal health services.

  7. Illegals and expulsion in Africa: the Nigerian experience.

    Science.gov (United States)

    Adepoju, A

    1984-01-01

    The persistence and widespread nature of undocumented migration in Africa is due to 1) the absence of barriers or the arbitrariness of national frontiers, 2) the large stretch of unpoliced borders, 3) ignorance about the existence of borders, and 4) the absence or inadequacy of migration laws and regulations in both the countries of origin and destination. The free movement of persons in Africa has a long tradition. Over a large part of Africa, international migration is regarded as an extension of internal migration. The free movement of persons across frontiers in Africa historically has been facilitated by the cultural affinity of communities divided by international boundaries and the colonial policies of both the French and British. The "migration" of nomads pays little regard to international borders and is largely undocumented, even in national censuses. The frontier workers along the borders of Uganda and Kenya where members of the same extended family live on both sides of the borders and commute daily are statistically regarded as international migrants, without regard for the sociocultural realities of the African situation. Political independence substantially altered the erstwhile free movement of persons across African countries as national governments enacted immigration laws and regulations. The newly independent countries wanted to reserve employment for nationals. The Sahelian drought, internal strife in Chad, the deteriorating economic situation in Ghana, the oil-lead economic boom in Nigeria, and the treaty on the free movement of people in the community accelerate the tempo of undocumented migration in West Africa. Also, migration laws and regulations are not always rigorously enforced. Expulsion and deportation are common policy measures directed at illegal migrants resident in African countries. In Nigeria, the events leading to the expulsion of aliens were gradual, but in all cases, the actual expulsion--or decisions to expel--are usually

  8. Potential impacts of afforestation on climate change and extreme events in Nigeria

    Science.gov (United States)

    Abiodun, Babatunde J.; Salami, Ayobami T.; Matthew, Olaniran J.; Odedokun, Sola

    2013-07-01

    Afforestation is usually thought as a good approach to mitigate impacts of warming over a region. This study presents an argument that afforestation may have bigger impacts than originally thought by previous studies. The study investigates the impacts of afforestation on future climate and extreme events in Nigeria, using a regional climate model (RegCM3), forced with global climate model simulations. The impacts of seven afforestation options on the near future (2031-2050, under A1B scenario) climate and the extreme events are investigated. RegCM3 replicates essential features in the present-day (1981-2000) climate and the associated extreme events, and adequately simulates the seasonal variations over the ecological zones in the country. However, the model simulates the seasonal climate better over the northern ecological zones than over the southern ecological zones. The simulated spatial distribution of the extreme events agrees well with the observation, though the magnitude of the simulated events is smaller than the observed. The study shows that afforestation in Nigeria could have both positive and negative future impacts on the climate change and extreme events in the country. While afforestation reduces the projected global warming and enhances rainfall over the afforested area (and over coastal zones), it enhances the warming and reduces the rainfall over the north-eastern part of the country. In addition, the afforestation induces more frequent occurrence of extreme rainfall events (flooding) over the coastal region and more frequent occurrence of heat waves and droughts over the semi-arid region. The positive and negative impacts of the afforestation are not limited to Nigeria; they extend to the neighboring countries. While afforestation lowers the warming and enhances rainfall over Benin Republic, it increases the warming and lowers the rainfall over Niger, Chad and Cameroon. The result of the study has important implication for the ongoing climate

  9. Reverse phase protein arrays in signaling pathways: a data integration perspective

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    Creighton CJ

    2015-07-01

    Full Text Available Chad J Creighton,1,3 Shixia Huang2,3 1Department of Medicine, 2Department of Molecular and Cellular Biology, 3Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA Abstract: The reverse phase protein array (RPPA data platform provides expression data for a prespecified set of proteins, across a set of tissue or cell line samples. Being able to measure either total proteins or posttranslationally modified proteins, even ones present at lower abundances, RPPA represents an excellent way to capture the state of key signaling transduction pathways in normal or diseased cells. RPPA data can be combined with those of other molecular profiling platforms, in order to obtain a more complete molecular picture of the cell. This review offers perspective on the use of RPPA as a component of integrative molecular analysis, using recent case examples from The Cancer Genome Altas consortium, showing how RPPA may provide additional insight into cancer besides what other data platforms may provide. There also exists a clear need for effective visualization approaches to RPPA-based proteomic results; this was highlighted by the recent challenge, put forth by the HPN-DREAM consortium, to develop visualization methods for a highly complex RPPA dataset involving many cancer cell lines, stimuli, and inhibitors applied over time course. In this review, we put forth a number of general guidelines for effective visualization of complex molecular datasets, namely, showing the data, ordering data elements deliberately, enabling generalization, focusing on relevant specifics, and putting things into context. We give examples of how these principles can be utilized in visualizing the intrinsic subtypes of breast cancer and in meaningfully displaying the entire HPN-DREAM RPPA dataset within a single page. Keywords: RPPA, proteomics, molecular profiling, integrative analysis, breast cancer, TCGA 

  10. Dietary algae and HIV/AIDS: proof of concept clinical data.

    Science.gov (United States)

    Teas, J; Irhimeh, M R

    2012-06-01

    Dietary algae have been reported to decrease HIV viral fusion/entry and replication and increase immune response, suggesting that regular consumption of algae by people in Japan, Korea, and Chad could be an important factor in their relatively low HIV/AIDS rates. Five antiretroviral-naïve people with HIV (three females, two males; five African Americans) living in Columbia SC participated in the phase I study of acute toxicity. Subjects were randomly assigned to 5 g day(-1) brown seaweed (Undaria pinnatifida), Spirulina (Arthrospira platensis), or a combination of both. Endpoints included HIV viral load, complete blood count (CBC), metabolic and lipid panel, and quality of life questionnaire data. When no short-term toxicities were observed, six additional subjects (four females, two males; five African Americans, one Latina) were recruited to further evaluate short- and long-term toxicities (phase II). No adverse effects were observed for the 11 subjects in the phase I trial, and quality of life indicators improved at 3 weeks. No significant changes were observed in CBC, metabolic or lipid panel analyses. CD4 cells (milliliters) and HIV-1 viral load remained stable over the first 3-month phase II study period. One subject continued in the study for 13 months and had clinically significant improvement in CD4 (>100 cells mL(-1)) and decreased HIV viral load of 0.5 log(10). Our pilot data suggest that Undaria, Spirulina, and a combination of both were nontoxic and over time may improve clinical endpoints of HIV/AIDS. PMID:22661829

  11. Image Fusion-Based Change Detection for Flood Extent Extraction Using Bi-Temporal Very High-Resolution Satellite Images

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    Younggi Byun

    2015-08-01

    Full Text Available Change detection based on satellite images acquired from an area at different dates is of widespread interest, according to the increasing number of flood-related disasters. The images help to generate products that support emergency response and flood management at a global scale. In this paper, a novel unsupervised change detection approach based on image fusion is introduced. The approach aims to extract the reliable flood extent from very high-resolution (VHR bi-temporal images. The method takes an advantage of the spectral distortion that occurs during image fusion process to detect the change areas by flood. To this end, a change candidate image is extracted from the fused image generated with bi-temporal images by considering a local spectral distortion. This can be done by employing a universal image quality index (UIQI, which is a measure for local evaluation of spectral distortion. The decision threshold for the determination of changed pixels is set by applying a probability mixture model to the change candidate image based on expectation maximization (EM algorithm. We used bi-temporal KOMPSAT-2 satellite images to detect the flooded area in the city of N′djamena in Chad. The performance of the proposed method was visually and quantitatively compared with existing change detection methods. The results showed that the proposed method achieved an overall accuracy (OA = 75.04 close to that of the support vector machine (SVM-based supervised change detection method. Moreover, the proposed method showed a better performance in differentiating the flooded area and the permanent water body compared to the existing change detection methods.

  12. Duloxetine in the management of diabetic peripheral neuropathic pain

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    Boomershine CS

    2011-07-01

    Full Text Available Michelle J Ormseth, Beth A Sholz, Chad S BoomershineDivision of Rheumatology and Immunology, Vanderbilt University, Nashville, TN, USAAbstract: Diabetic neuropathy affects up to 70% of diabetics, and diabetic peripheral neuropathic pain (DPNP is the most common and debilitating of the diabetic neuropathies. DPNP significantly reduces quality of life and increases management costs in affected patients. Despite the impact of DPNP, management is poor with one-quarter of patients receiving no treatment and many treated with medications having little or no efficacy in managing DPNP. Duloxetine is one of two drugs approved by the United States Food and Drug Administration for DPNP management. Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI proven safe, effective, and cost-saving in reducing DPNP symptoms at a dose of 60 mg/day. Duloxetine doses greater than 60 mg/day for DPNP management are not recommended since they are no more efficacious and associated with more side effects; addition of pregabalin or gabapentin for these patients may be beneficial. Side effects of duloxetine are generally mild and typical for the SNRI class including nausea, dizziness, somnolence, fatigue, sweating, dry mouth, constipation, and diarrhea. Given its other indications, duloxetine is a particularly good choice for DPNP treatment in patients with coexisting depression, anxiety, fibromyalgia, or chronic musculoskeletal pain. Duloxetine treatment had no clinically significant effect on glycemic control and did not increase the risk of cardiovascular events in diabetes patients. However, duloxetine use should be avoided in patients with hepatic disease or severe renal impairment. Given its safety, efficacy, and tolerability, duloxetine is an excellent choice for DPNP treatment in many patients.Keywords: duloxetine, diabetic peripheral neuropathic pain, review, treatment

  13. Disentangling Migratory Routes and Wintering Grounds of Iberian Near-Threatened European Rollers Coracias garrulus

    Science.gov (United States)

    Rodríguez-Ruiz, Juan; de la Puente, Javier; Parejo, Deseada; Valera, Francisco; Calero-Torralbo, Miguel A.; Reyes-González, José M.; Zajková, Zuzana; Bermejo, Ana; Avilés, Jesús M.

    2014-01-01

    Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1) a mainly nocturnal flying activity, 2) that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3) that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller. PMID:25551212

  14. Hydrocarbon prospectivity of Nigeria's inland basins: From the viewpoint of organic geochemistry and organic petrology

    Energy Technology Data Exchange (ETDEWEB)

    Obaje, N.G.; Wehner, H.; Scheeder, G.; Abubakar, M.B.; Jauro, A. [Nasarawa State University, Keffi (Nigeria). Dept. of Geology & Mining

    2004-03-01

    The inland basins of Nigeria comprise the Anambra basin, the lower, middle, and upper Benue trough, the southeastern sector of the Chad basin, the Mid-Niger (Bida) basin, and the Sokoto basin. Organic geochemical and organic petrologic studies indicate that coal beds constitute major potential source rocks in the whole of the Benue trough (Anambra basin inclusive). The generation and production of liquid and gaseous hydrocarbons from coal beds is presently indisputable worldwide. In the Anambra basin, the coal beds in the Mamu Formation (Campanian-Maastrichtian) have total organic carbon (TOC) contents of as much as 60.8 wt.%, mean hydrogen index (HI) of 3 64 mg HC/g TOC, vitrinite reflectance (R-o) of 0.54-0.56%, and T-max 430-433{sup o}C. Biomarker data indicate a dominance of high-molecular-weight n-alkanes, very high pristane/phytane ratios, pronounced odd-over-even predominance (OEP), a preponderance of C-29 regular steranes, and relatively high contents of C-28. In the middle Benue trough, the coal beds of the Turonian-Coniacian Awgu Formation have TOC contents of as much as 79.1 wt.%, R-o of 0.83-1.07%, and mean HI of 281 mg HC/g TOC, unimodal distributions of both low- and high-molecular-weight n-alkanes with no obvious OEP, a predominance of C-29 steranes, and relatively high contents of C-27 and C-28. Coal beds from the Coniacian-lower Santonian Lamja Formation in the upper Benue trough yielded TOC contents of as much as 50.7 wt.%, with HI of 184 mg HC/g TOC, R-o of 0.70-0.73%, low- and high-molecular-weight n-alkane dominance with an unpronounced OEP, high pristane/phytane ratios, and very high contents of C29 regular steranes.

  15. Transport of Saharan dust from the Bodélé Depression to the Amazon Basin: a case study

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ami

    2010-02-01

    Full Text Available Through long-range transport of dust, the Sahara desert supplies essential minerals to the Amazon rain forest. Since Saharan dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in Southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon.

    Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the Central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08 in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest.

    This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa, the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the marine boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.

  16. Disinsectization of African dried and smoked fish by means of irradiation

    International Nuclear Information System (INIS)

    The problem of conserving dried and smoked fish. Fresh water fisheries are one of the major sources of protein in Africa. More than 100,000 t of fish are believed to be caught commercially in the Niger basin and 150,000 t in that of the Chad. These dried or smoked fish are then exported throughout Black Africa. Through attack by parasitic insects more than 30 wt.% of the fish are destroyed. None of the conventional methods of combating these insects has so far produced any practical results. There have been several radiation experiments carried out to date. A series of irradiation experiments has been carried out in France with doses of 20,000, 100,000, 500,000 rad. The order of magnitude of lethal and sterilizing doses has been determined without any organoleptic change being observed at 500,000 rad. There are studies which are still necessary. These comprise eontomological studies, determination of practical dose, studies on nutritional value, research into packaging techniques, and economic analysis. These studies are not extensive if one leaves aside the problems of wholesomeness and edibility (for which, incidentally, very favourable results have already been obtained with fish subjected to doses well above the 15,000 to 40,000 rad which would probably be necessary in this case). The proposals for organizing research include preliminary studies which might be carried out either in Africa or Europe and technical development which would certainly necessitate the construction of a pilot plant in Africa. An economic study shows that for an increase of the order of 1% in the price of the product one can expect to eliminate losses amounting to several tens of per cent. (author). 1 tab

  17. Gene expression profile of the cartilage tissue spontaneously regenerated in vivo by using a novel double-network gel: Comparisons with the normal articular cartilage

    Directory of Open Access Journals (Sweden)

    Kurokawa Takayuki

    2011-09-01

    Full Text Available Abstract Background We have recently found a phenomenon that spontaneous regeneration of a hyaline cartilage-like tissue can be induced in a large osteochondral defect by implanting a double-network (DN hydrogel plug, which was composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid and poly-(N, N'-Dimetyl acrylamide, at the bottom of the defect. The purpose of this study was to clarify gene expression profile of the regenerated tissue in comparison with that of the normal articular cartilage. Methods We created a cylindrical osteochondral defect in the rabbit femoral grooves. Then, we implanted the DN gel plug at the bottom of the defect. At 2 and 4 weeks after surgery, the regenerated tissue was analyzed using DNA microarray and immunohistochemical examinations. Results The gene expression profiles of the regenerated tissues were macroscopically similar to the normal cartilage, but showed some minor differences. The expression degree of COL2A1, COL1A2, COL10A1, DCN, FMOD, SPARC, FLOD2, CHAD, CTGF, and COMP genes was greater in the regenerated tissue than in the normal cartilage. The top 30 genes that expressed 5 times or more in the regenerated tissue as compared with the normal cartilage included type-2 collagen, type-10 collagen, FN, vimentin, COMP, EF1alpha, TFCP2, and GAPDH genes. Conclusions The tissue regenerated by using the DN gel was genetically similar but not completely identical to articular cartilage. The genetic data shown in this study are useful for future studies to identify specific genes involved in spontaneous cartilage regeneration.

  18. The role of North African rivers in driving Mediterranean-Atlantic exchange

    Science.gov (United States)

    Flecker, Rachel; Marzocchi, Alice; van der Schee, Marlies; Meijer, Paul; Lofi, Johanna; Lunt, Dan

    2014-05-01

    The main driver for exchange through the Gibraltar Strait today is the density contrast between Mediterranean and Atlantic water. Mediterranean water is more saline than Atlantic water because the amount of water the Mediterranean loses through evaporation exceeds both precipitation and freshwater input from rivers. This means it has a negative hydrologic budget. In the Late Miocene however, a very large river known as the Esohabi River drained across North Africa and had its mouth in the Gulf of Sirt. This river was sourced in palaeo-Lake Chad and was strongly influenced by precession-driven monsoonal rainfall. Multiple General Circulation Model simulations through a single precessional cycle indicate that river water may only have reached the Mediterranean in significant quantities in summer during particular orbital configurations e.g. precession minima combined with eccentricity maxima. However, during high amplitude eccentricity maxima, the volume of water supplied through the Esohabi and Nile rivers may have been sufficient to switch the hydrologic budget from negative to positive. In doing so, the fresh water supply should have reduced the salinity of the Mediterranean and consequently the density contrast with adjacent Atlantic water leading to a reduction in exchange. In this presentation we explore the evidence for the timing and nature of freshwater input to the Mediterranean from North Africa. We also consider how relevant this freshwater flux may be in determining some of the major environmental and sedimentological changes in the Late Miocene to early Pliocene including some of the salinity changes that occurred during the Messinian Salinity Crisis.

  19. Electromagnetic Reciprocity.

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories

  20. Anti-Ebola vaccines and nucleoside drugs:research advances%抗埃博拉病毒疫苗和核酸类药物研究进展

    Institute of Scientific and Technical Information of China (English)

    李康; 周喆

    2015-01-01

    埃博拉病毒(EBOV)致病性和传染性强,死亡率高,常在西非热带地区暴发流行。目前相应的抗病毒药物和疫苗正加紧研发。 EBOV疫苗依据抗原递送方式主要可分为3类,包括基于非复制性病毒载体的疫苗、基于复制性病毒载体的疫苗和基于病毒蛋白抗原的疫苗。ChAd3-ZEBOV和VSV-EBOV是最具潜力的抗埃博拉疫苗。随着埃博拉病毒感染分子基础研究的深入,抗埃博拉病毒的核酸和核苷类似物药物也成为研究热点。%Anti-Ebola vaccines and nucleoside drugs:research advances Ebola virus was extremely virulent and highly transmissible and caused outbreak of severe hemorrhagic fevers with high mortality in the Africa tropical regions. Currently, Ebola epidemic raging in West Africa, antiviral vaccines and drugs have also accelerated the development process. Basing on antigen delivery methods, EBOV vaccines can be divided into three categories of technology platform, including nonreplicative viral vector-based vaccines, replicative viral vector-based vaccines and viral protein antigen-based vaccines. ChAd3-ZEBOV and VSV-EBOV are the most promising vaccines against Ebola. With the basic molecular research of Ebola virus infection deepening, polynucleotides drugs and nucleoside analogue drugs against Ebola virus are hot research topics.

  1. Combination of medial patellofemoral ligament reconstruction with vastus medialis advancement for chronic patellar dislocation

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; KANG Hui-jun; CHEN Bai-cheng; CHEN Wei; SU Yan-ling; ZHANG Ying-ze

    2010-01-01

    Background The medial patellofemoral ligament (MPFL) reconstruction is popular in clinical practice for chronic patellar dislocation; however, the combination with vastus medialis advancement is rare. The aim of this study was to evaluate the clinical outcome of the combination of MPFL reconstruction with vastus medialis advancement.Methods We retrospectively analyzed 69 patients with chronic patellar dislocation between July 2004 and October 2008: twenty eight cases with isolated MPFL reconstruction (group Ⅰ), forty one cases with the combination of MPFL reconstruction with vastus medialis advancement (group C). All patients had CT scans available for review with knee flexion at 30 degree, on which the congruence angle, patellar tilt angle and patellar lateral shift were measured. Physical apprehension tests were examined and the redislocation was recorded. In addition, knee function was evaluated using the Kujala score and subjective questionnaires.Results Patients were followed up for a mean of 42 months (12-65 months) without a recurrent dislocation reported.Postoperatively, all indexes on CT scan were within the normal range without a statistical difference between the two groups. Results from the apprehension test showed eight patients in group Ⅰ and three in group Chad patellar lateral shift exceeding 1.5 cm with a hard end point (P <0.05). The Kujala score improved significantly from 51.3±4.5 to 79.9±6.2 in group Ⅰ and from 53.7±5.2 to 83.9±6.5 in group C (P >0.05). However, the subjective questionnaire revealed a significant difference (P <0.05), including 12 excellent, seven good and nine fair in group Ⅰ and 30 excellent, six good and five fair in group C.Conclusion The combination of MPFL reconstruction with vastus medialis advancement is better than isolated reconstruction to improve the subjective effects and decrease the patellar instability rate for chronic patellar dislocation.

  2. Nigeria National Petroleum Reserves Asset: Looking Beyond the Niger Delta

    International Nuclear Information System (INIS)

    Nigeria's current national petroleum reserves asset (proven) put at 28 billion barrels of oil and 150 trillion standard cubic feet of gas derives mainly from the Niger Delta onshore and offshore.However, there are opportunities to tremendously add to this asset from the inland basins. These inland basins have continued to frustrate the efforts of many explorers, principally because of their virginity and far distance from existing infrastructure, and for these reasons, many international companies have turned their focus away from frontier onshore to frontier deep-water and ultra deep-water offshore.Petroleum exploration, particularly in the Sudan and Chad Republics has shown that commercial success can be achieved in our own sector, even if it may take some time to put all the elements together. Some pointers have been found from the successes in the other rifted inland basins and the strategies adopted there have been examined in this paper. Congnizance has also been taken of the relative success of Shell's Kolmani River-1 well (33 billion cubit feet of gas) in the Gongola Basin. The paper went ahead to highlight potential petroleum systems in the different sectors of Nigeria's inland basins.Recommendations have also been put forward, which include amongst others (i) the introduction of a JV arrangement that allows State Governments on the inland basins to participate in the exploration for hydrocarbons in their domains (ii) tie future allocation of offshore blocks to acquisition of at least a block in any of the inland basins (iii) initiate a programme of deep drilling and coring of at least one research well to penetrate the entire sedimentary rock successions in each of the inland basins to facilitate a better understanding of their petroleum geology and benefit future exploration campaigns; to be funded and supervised by the Petroleum Technology Development Fund (PTDF)

  3. Current perspectives on antibody-mediated rejection after lung transplantation

    Directory of Open Access Journals (Sweden)

    Witt CA

    2014-10-01

    Full Text Available Chad A Witt, Ramsey R Hachem Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, Saint Louis, MO, USA Abstract: The role of donor-specific antibodies (DSA to human leukocyte antigens and the burden of antibody-mediated rejection (AMR in lung transplantation remain enigmatic. Over the past several years, evidence has been emerging that humoral immunity plays an important role in the development of both acute and chronic lung allograft dysfunction (CLAD. Multiple case reports and case series have identified lung allograft recipients with clinical findings consistent with acute AMR. However, there is currently no widely accepted definition for AMR in lung transplantation, and this has been a significant barrier to furthering our understanding of this form of rejection. Nonetheless, the development of DSA after transplantation has consistently been identified as an independent risk factor for persistent and high-grade acute cellular rejection and CLAD. This has raised the possibility that chronic AMR may be a distinct phenotype of CLAD although evidence supporting this paradigm is still lacking. Additionally, antibodies to lung-restricted self-antigens (collagen V and K-α 1 tubulin have been associated with primary graft dysfunction early and the development of CLAD late after transplantation, and emerging evidence underscores significant interactions between autoimmunity and alloimmunity after transplantation. There is currently an active International Society for Heart and Lung Transplantation working group that is developing an operational definition for AMR in lung transplantation. This will be critical to improve our understanding of this form of rejection and conduct clinical trials to identify optimal treatment strategies. This review will summarize the literature on DSA and AMR in lung transplantation and discuss the impact of antibodies to self-antigens on lung

  4. The use of unsaturated zone solutes and deuterium profiles in the study of groundwater recharge in the semi-arid zone of Nigeria

    International Nuclear Information System (INIS)

    Two unsaturated zone profiles (MF and MG) in NE Nigeria have been sampled for inert tracers (Cl, Br, NO3 and δ2H to investigate recharge rates and processes. The upper MF and MG profiles have sandy lithology, lower moisture content (2H around -30 per mille. All these indicate that present day recharge is taking place. The lower section of the MF profile shows a distinct contrast with high moisture content (up to 27%), very high chloride (average 2892 mg/L) and relatively enriched deuterium (-12 per mille), indicating the effect of evaporative enrichment. This lower section corresponds to low permeability lacustrine deposits probably representing the former bed of Lake Chad where little or no infiltration has been occurring since the mid-Holocene when the lake extended over this area. The sand-covered areas of the Sahel of the NE Nigeria provide an important phreatic aquifer. An estimation of the amount of recharge using the unsaturated zone chloride mass balance gives significant rates of 14 mm/a and 22 mm/a for the upper MF and MG profiles respectively. These rates mainly span the period of the recent Sahel drought and even higher recharge rates may occur during wetter periods. These rates fall within the 14 mm/a to 53 mm/a range estimated for the Manga Grasslands area in the NE Nigeria obtained in an earlier study. From the water resource point of view, the region has potential for perennially-recharged groundwater resources that can sustain the present abstraction level which is mainly via dug wells. (author)

  5. Quality of Life, Activity Impairment, and Healthcare Resource Utilization Associated with Atrial Fibrillation in the US National Health and Wellness Survey

    Science.gov (United States)

    Goren, Amir; Liu, Xianchen; Gupta, Shaloo; Simon, Teresa A.; Phatak, Hemant

    2013-01-01

    Objectives This study builds upon current studies of atrial fibrillation (AF) and health outcomes by examining more comprehensively the humanistic burden of illness (quality of life, activity impairment, and healthcare resource utilization) among adult patients with AF, using a large, nationally representative sample and matched controls. Methods Data were analyzed from the Internet-based 2009 US National Health and Wellness Survey. Outcomes were Mental and Physical Component Summary (MCS and PCS) and health utility scores from the SF-12, activity impairment, hospitalizations, and healthcare provider and emergency room (ER) visits. Patients with self-reported diagnosis of AF were matched randomly on age and gender with an equal number of respondents without AF. Generalized linear models examined outcomes as a function of AF vs. non-AF status, controlling for CHADS2 score, comorbidity counts, demographics, and clinical variables. Exploratory structural equation modeling assessed the above in an integrated model of humanistic burden. Results Mean age of AF patients (1,296 from a total sample of 75,000) was 64.9 years and 65.1% were male. Adjusting for covariates, compared with non-AF patients, AF patients had lower MCS, PCS, and utility scores, greater activity impairment (rate ratio = 1.26), more traditional provider visits (rate ratio = 1.43), and increased odds of ER visits (OR = 2.53) and hospitalizations (OR = 2.71). Exploratory structural equation modeling analyses revealed that persons with AF experienced a significantly higher overall humanistic burden. Conclusions This study highlights and clarifies the substantial burden of AF and its implications for preparing efficacious AF management plans to address the imminent rise in prevalence. PMID:23951122

  6. Oil for health in sub-Saharan Africa: health systems in a 'resource curse' environment

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    Calain Philippe

    2008-10-01

    Full Text Available Abstract Background In a restricted sense, the resource curse is a theory that explains the inverse relationship classically seen between dependence on natural resources and economic growth. It defines a peculiar economic and political environment, epitomised by oil extraction in sub-Saharan Africa. Methods Based on secondary research and illustrations from four oil-rich geographical areas (the Niger Delta region of Nigeria, Angola, southern Chad, Southern Sudan, I propose a framework for analysing the effects of the resource curse on the structure of health systems at sub-national levels. Qualitative attributes are emphasised. The role of the corporate sector, the influence of conflicts, and the value of classical mitigation measures (such as health impact assessments are further examined. Results Health systems in a resource curse environment are classically fractured into tripartite components, including governmental health agencies, non-profit non-governmental organisations, and the corporate extractive sector. The three components entertain a range of contractual relationships generally based on operational considerations which are withdrawn from social or community values. Characterisation of agencies in this system should also include: values, operating principles, legitimacy and operational spaces. From this approach, it appears that community health is at the same time marginalised and instrumentalised toward economic and corporate interests in resource curse settings. Conclusion From a public health point of view, the resource curse represents a fundamental failure of dominant development theories, rather than a delay in creating the proper economy and governance environment for social progress. The scope of research on the resource curse should be broadened to include more accurate or comprehensive indicators of destitution (including health components and more open perspectives on causal mechanisms.

  7. Milnacipran for the management of fibromyalgia syndrome

    Directory of Open Access Journals (Sweden)

    Michelle J Ormseth

    2010-03-01

    Full Text Available Michelle J Ormseth, Anne E Eyler, Cara L Hammonds, Chad S BoomershineDivision of Rheumatology and Immunology, Vanderbilt University, Nashville, TN, USAAbstract: Fibromyalgia syndrome (FMS is a widespread pain condition associated with fatigue, cognitive dysfunction, sleep disturbance, depression, anxiety, and stiffness. Milnacipran is one of three medications currently approved by the Food and Drug Administration in the United States for the management of adult FMS patients. This review is the second in a three-part series reviewing each of the approved FMS drugs and serves as a primer on the use of milnacipran in FMS treatment including information on pharmacology, pharmacokinetics, safety and tolerability. Milnacipran is a mixed serotonin and norepinephrine reuptake inhibitor thought to improve FMS symptoms by increasing neurotransmitter levels in descending central nervous system inhibitory pathways. Milnacipran has proven efficacy in managing global FMS symptoms and pain as well as improving symptoms of fatigue and cognitive dysfunction without affecting sleep. Due to its antidepressant activity, milnacipran can also be beneficial to FMS patients with coexisting depression. However, side effects can limit milnacipran tolerability in FMS patients due to its association with headache, nausea, tachycardia, hyper- and hypotension, and increased risk for bleeding and suicidality in at-risk patients. Tolerability can be maximized by starting at low dose and slowly up-titrating if needed. As with all medications used in FMS management, milnacipran works best when used as part of an individualized treatment regimen that includes resistance and aerobic exercise, patient education and behavioral therapies.Keywords: fibromyalgia, milnacipran, treatment

  8. Modeling annual flooding in the Logone floodplain in Cameroon

    Science.gov (United States)

    Fernandez, A.; Najafi, M. R.; Durand, M. T.; Mark, B. G.; Moritz, M.; Shastry, A.; Laborde, S.; Phang, S. C.; Hamilton, I.; Ningchuan, X.; Neal, J. C.

    2015-12-01

    The Logone floodplain (LFP), part of the Lake Chad Basin, is flooded annually by water from the Logone River and its branches during September and October. The inundated LFP is highly productive, providing support for fishing, pastoralism, and agriculture. In the last few decades, droughts, dam construction, manmade fishing canals (MFCs), and irrigation development have caused significant shifts in the LFP's flooding regime. Recently, MFCs have proliferated as consequence of ecological and manmade changes in the LFP. Future impacts of these modifications may parallel projected, although still uncertain, regional hydroclimatic changes derived from global warming. In order to understand feedbacks between human actions and hydroclimate, we are developing an integrated model that links hydroclimate, hydraulics, and human dynamics such as fishermen and pastoralist behavior. Here we present one component of this research focused on simulating the annual flooding dynamics of the LFP using LISFLOOD-FP, a raster-based numerical model that includes sub-grid parameterization of MFCs. Our goal is to evaluate the model's skill to simulate spatiotemporal features of the inundated LFP using a minimum amount of input data, such as discontinuous time series of river discharge and satellite-derived rainfall. Our simulations using three different spatial resolutions (1, 0.5, and 0.25-km grid-cell) suggest that the model is insensitive to pixel size, showing no significant differences between simulated volume, discharge, flooded area, and flood seasonality. Despite the model is able to simulate flow, with a Nash Sutcliff efficiency of 0.81, we find some significant spatial mismatch between observed and simulated inundation areas. In addition, results indicate that overbank flow provides more annual flood volume than rainfall. We discuss the impact of topographic and climatic input data on these results, as well as the potential to simulate the effects of MFCs on the local hydrology.

  9. Modelling soil dust aerosol in the Bodélé depression during the BoDEx campaign

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    R. Washington

    2006-05-01

    Full Text Available We present regional model simulations of the dust emission events during the Bodélé Dust Experiment (BoDEx that was carried out in February and March 2005 in Chad. A box model version of the dust emission model is used to test different input parameters for the emission model, and to compare the dust emissions computed with observed wind speeds to those calculated with wind speeds from the regional model simulation. While field observations indicate that dust production occurs via self-abrasion of saltating diatomite flakes in the Bodélé, the emission model based on the assumption of dust production by saltation and using observed surface wind speeds as input parameters reproduces observed dust optical thicknesses well. Although the peak wind speeds in the regional model underestimate the highest wind speeds occurring on 10–12 March 2005, the spatio-temporal evolution of the dust cloud can be reasonably well reproduced by this model. Dust aerosol interacts with solar and thermal radiation in the regional model; it is responsible for a decrease in maximum daytime temperatures by about 5 K at the beginning the dust storm on 10 March 2005. This direct radiative effect of dust aerosol accounts for about half of the measured temperature decrease compared to conditions on 8 March. Results from a global dust model suggest that the dust from the Bodélé is an important contributor to dust crossing the African Savannah region towards the Gulf of Guinea and the equatorial Atlantic, where it can contribute up to 40% to the dust optical thickness.

  10. Clinical Differences between Subtypes of Atrial Fibrillation and Flutter: Cross-Sectional Registry of 407 Patients

    Directory of Open Access Journals (Sweden)

    Eduardo Dytz Almeida

    2015-01-01

    Full Text Available Introduction: Atrial fibrillation and atrial flutter account for one third of hospitalizations due to arrhythmias, determining great social and economic impacts. In Brazil, data on hospital care of these patients is scarce. Objective: To investigate the arrhythmia subtype of atrial fibrillation and flutter patients in the emergency setting and compare the clinical profile, thromboembolic risk and anticoagulants use. Methods: Cross-sectional retrospective study, with data collection from medical records of every patient treated for atrial fibrillation and flutter in the emergency department of Instituto de Cardiologia do Rio Grande do Sul during the first trimester of 2012. Results: We included 407 patients (356 had atrial fibrillation and 51 had flutter. Patients with paroxysmal atrial fibrillation were in average 5 years younger than those with persistent atrial fibrillation. Compared to paroxysmal atrial fibrillation patients, those with persistent atrial fibrillation and flutter had larger atrial diameter (48.6 ± 7.2 vs. 47.2 ± 6.2 vs. 42.3 ± 6.4; p < 0.01 and lower left ventricular ejection fraction (66.8 ± 11 vs. 53.9 ± 17 vs. 57.4 ± 16; p < 0.01. The prevalence of stroke and heart failure was higher in persistent atrial fibrillation and flutter patients. Those with paroxysmal atrial fibrillation and flutter had higher prevalence of CHADS2 score of zero when compared to those with persistent atrial fibrillation (27.8% vs. 18% vs. 4.9%; p < 0.01. The prevalence of anticoagulation in patients with CHA2DS2-Vasc ≤ 2 was 40%. Conclusions: The population in our registry was similar in its comorbidities and demographic profile to those of North American and European registries. Despite the high thromboembolic risk, the use of anticoagulants was low, revealing difficulties for incorporating guideline recommendations. Public health strategies should be adopted in order to improve these rates.

  11. Exploring barriers to optimal anticoagulation for atrial fibrillation: interviews with clinicians

    Directory of Open Access Journals (Sweden)

    Decker C

    2012-06-01

    Full Text Available Carole Decker,1 Linda Garavalia,2 Brian Garavalia,1 Teresa Simon,3 Matthew Loeb,4 John Spertus6, William Daniel51Mid America Heart Institute at Saint Luke's Hospital in Kansas City Missouri, University of Missouri-Kansas City School of Nursing, 2University of Missouri-Kansas City School of Pharmacy, Kansas City, MO, 3Bristol-Myers Squibb, Princeton, NJ, 4Plaza Primary Care and Geriatrics, 5Saint Luke's Cardiovascular Consultants, Kansas City, MO, 6Mid America Heart Institute at Saint Luke's Hospital in Kansas City Missouri, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USABackground: Warfarin, the most commonly used antithrombotic agent for stroke prophylaxis in atrial fibrillation (AF, requires regular monitoring, frequent dosage adjustments, and dietary restrictions. Clinicians' perceptions of barriers to optimal AF management are an important factor in treatment. Anticoagulation management for AF is overseen by both cardiology and internal medicine (IM practices. Thus, gaining the perspective of specialists and generalists is essential in understanding barriers to treatment. We used qualitative research methods to define key issues in the prescription of warfarin therapy for AF by cardiology specialists and IM physicians.Methods and results: Clinicians were interviewed to identify barriers to warfarin treatment in a large Midwestern city. Interviews were conducted until thematic saturation occurred. Content analysis yielded several themes. The most salient theme that emerged from clinician interviews was use of characteristics other than the patient's CHADS2 score to enact a treatment plan, such as the patient's social situation and past medication-taking behavior. Other themes included patient knowledge, real-world problems, breakdown in communication, and clinician reluctance.Conclusion: Warfarin treatment is associated with many challenges. The barriers identified by clinicians highlight the unmet need associated

  12. Stroke prevention in atrial fibrillation: findings from Tuscan FADOI Stroke Registry

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    Luca Masotti

    2014-06-01

    Full Text Available Despite vitamin K antagonists (VKAs are considered the first choice treatment for stroke prevention in atrial fibrillation (AF, literature shows their underuse in this context. Since data about VKAs use prior and after acute stroke lack, the aim of this study was to focus on management of anticoagulation with VKAs in this context. Data were retrieved from Tuscan FADOI Stroke Registry, an online data bank aimed to report on characteristics of stroke patients consecutively admitted in Internal Medicine wards in 2010 and 2011. In this period 819 patients with mean age 76.5±12.3 years were enrolled. Data on etiology were available for 715 of them (88.1%, 87% being ischemic and 13% hemorrhagic strokes. AF was present in 238 patients (33%, 165 (69.3% having a known AF before hospitalization, whereas 73 patients (31.7% received a new diagnosis of AF. A percentage of 89% of strokes in patients with known AF were ischemic and 11% hemorrhagic. A percentage of 86.7% of patients with known AF had a CHADS2 ≥2, but only 28.3% were on VKAs before hospitalization. A percentage of 78.8% of patients treated with VKAs before stroke had an international normalized ratio (INR ≤2.0; 68.7% of patients with VKAs-related hemorrhagic strokes had INR ≤3.0. Combined endpoint mortality or severe disability in patients with ischemic stroke associated with AF was present in 47%, while it was present in 19.30% and 19.20% of atherothrombotic and lacunar strokes, respectively. At hospital discharge, VKAs were prescribed in 25.9% of AF related ischemic stroke patients. AF related strokes are burdened by severe outcome but VKAs are dramatically underused in patients with AF, even in higher risk patients. Efforts to improve anticoagulation in this stroke subtype are warranted.

  13. Disentangling migratory routes and wintering grounds of Iberian near-threatened European Rollers Coracias garrulus.

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    Juan Rodríguez-Ruiz

    Full Text Available Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1 a mainly nocturnal flying activity, 2 that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3 that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller.

  14. The Cost of Thromboembolic Events and their Prevention among Patients with Atrial Fibrillation

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    Thomas Davidson, PhD

    2011-02-01

    Full Text Available Aim: Atrial fibrillation (AF is the most common type of cardiac arrhythmia. People with AF have a significantly increased risk of thromboembolic events, including stroke, and the main treatment is therefore aimed at preventing thromboembolic events via anticoagulation with warfarin or acetylsalicylic acid. However, the development of new anticoagulation treatments has prompted a need to know the current cost of AF-related thromboembolic events, for future cost-effectiveness comparisons with the existing treatments. In this study, we estimated the cost of thromboembolic events and their prevention among Swedish AF patients in 2010. Methods: The relevant costs were identified, quantified, and valued. The complications included were ischaemic and haemorrhagic stroke, gastrointestinal bleeding, and other types of major bleeding caused by AF. Treatments intended to lower the risk of ischaemic stroke were also included. A societal perspective was used, including productivity loss due to morbidity. Patients with a CHADS2 score of 1 or higher were included. Results: Among the 9 340 682 inhabitants of Sweden, there are 118 000 patients with AF and at least one more risk factor for stroke, comprising 1.26% of the population. Of these patients, 43.3% are treated with warfarin, 28.3% use acetylsalicylic acid, and 28.3% are assumed to have no anticoagulation treatment. The cost of AF-related complications and its prevention in Sweden was estimated at €437 million for 2010, corresponding to €3 712 per AF patient per year. The highest cost was caused by stroke, and the second highest by the cost of monitoring the warfarin treatment. As the prevalence of AF is expected to increase in the future, AF-related costs are also expected to rise. Conclusion: Thromboembolic events cause high costs. New, easily-administered treatments that could reduce the risk of stroke have the potential to be cost-effective.

  15. Cost-effectiveness of apixaban compared with warfarin for stroke prevention in atrial fibrillation.

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    Soyon Lee

    Full Text Available BACKGROUND: Apixaban was shown to be superior to adjusted-dose warfarin in preventing stroke or systemic embolism in patients with atrial fibrillation (AF and at least one additional risk factor for stroke, and associated with reduced rates of hemorrhage. We sought to determine the cost-effectiveness of using apixaban for stroke prevention. METHODS: Based on the results from the Apixaban Versus Warfarin in Patients with Atrial Fibrillation (ARISTOTLE trial and other published studies, we constructed a Markov model to evaluate the cost-effectiveness of apixaban versus warfarin from the Medicare perspective. The base-case analysis assumed a cohort of 65-year-old patients with a CHADS(2 score of 2.1 and no contraindication to oral anticoagulation. We utilized a 2-week cycle length and a lifetime time horizon. Outcome measures included costs in 2012 US$, quality-adjusted life-years (QALYs, life years saved and incremental cost-effectiveness ratios. RESULTS: Under base case conditions, quality adjusted life expectancy was 10.69 and 11.16 years for warfarin and apixaban, respectively. Total costs were $94,941 for warfarin and $86,007 for apixaban, demonstrating apixaban to be a dominant economic strategy. Upon one-way sensitivity analysis, these results were sensitive to variability in the drug cost of apixaban and various intracranial hemorrhage related variables. In Monte Carlo simulation, apixaban was a dominant strategy in 57% of 10,000 simulations and cost-effective in 98% at a willingness-to-pay threshold of $50,000 per QALY. CONCLUSIONS: In patients with AF and at least one additional risk factor for stroke and a baseline risk of ICH risk of about 0.8%, treatment with apixaban may be a cost-effective alternative to warfarin.

  16. Intracerebral Hematoma Occurring During Warfarin Versus Non-Vitamin K Antagonist Oral Anticoagulant Therapy.

    Science.gov (United States)

    Takahashi, Haruhiko; Jimbo, Yasushi; Takano, Hiroki; Abe, Hiroshi; Sato, Masahito; Fujii, Yukihiko; Aizawa, Yoshifusa

    2016-07-15

    The neuroradiological findings and its outcomes of intracerebral hemorrhage (ICH) were compared between the non-vitamin K antagonist oral anticoagulant (NOAC) therapy and warfarin therapy. In the latest 3 years, 13 cases of nonvalvular atrial fibrillation on NOAC therapy were admitted for ICH. For comparison, 65 age- and gender-comparable patients with ICH on warfarin therapy were recruited. Three NOACs had been prescribed: dabigatran (n = 4), rivaroxaban (n = 2), and apixaban (n = 7). The average ages were 76 ± 9 and 78 ± 8 years in the warfarin (n = 65) and NOAC groups (n = 13), respectively. There was no difference in the clinical features, including the CHADS2 score or HAS-BLED score: 2.62 ± 1.31 versus 2.62 ± 1.33, or 1.09 ± 0.43 versus 1.00 ± 0.41, for the warfarin and NOAC groups, respectively. The volume of ICH warfarin (p = 0.0106). The expansion of hematoma was limited to 7 patients (10.8%) of the warfarin group. A lower hospital mortality and better modified Rankin Scale were observed in the NOAC group than in the warfarin group: 1 (7.7%) versus 27 (41.5%; p = 0.0105) and 3.2 ± 1.4 versus 4.5 ± 1.6 (p = 0.0057), respectively. In conclusion, ICH on NOAC therapy had smaller volume of hematoma with reduced rate of expansion and decreased mortality compared with its occurrence on warfarin. PMID:27289294

  17. Synergistic Use of Remote Sensing and Modeling for Tracing Dust Storms in the Mediterranean

    Directory of Open Access Journals (Sweden)

    D. G. Kaskaoutis

    2012-01-01

    Full Text Available This study focuses on the detection of the dust source region and monitoring of the transport of the dust plume from its primary outflow to final deposition. The application area is the Sahara desert and the eastern Mediterranean, where two dust events occurred during the period 4–6 February 2009, an unusual event for a winter period. The Aqua-MODIS and OMI observations clearly define the spatial distribution of the dust plumes, while the CALIPSO observations of total attenuated backscatter (TAB at 532 nm, depolarization ratio (DR, and attenuated color ratio (1064/532 nm on 5 February 2009 provide a clear view and vertical structure of the dust-laden layer. The dust source region is defined to be near the Chad-Niger-Libyan borders, using satellite observations and model (DREAM output. This dust plume is vertically extended up to 2.5 km and is observed as a mass plume of dust from surface level to that altitude, where the vertical variation of TAB (0.002 to 0.2 and DR (0.2–0.5 implies dust-laden layer with non-spherical particles. CALIPSO profiles show that after the dust plume reached at its highest level, the dust particles start to be deposited over the Mediterranean and the initial dust plume was strongly attenuated, while features of dust were limited below about 1–1.5 km for latitudes northern of ~36° (Greek territory.

  18. Transport of North African dust from the Bodélé depression to the Amazon Basin: a case study

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    Y. Ben-Ami

    2010-08-01

    Full Text Available Through long-range transport of dust, the North-African desert supplies essential minerals to the Amazon rain forest. Since North African dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon.

    Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08 in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest.

    This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa (most likely with contribution from other dust sources in the region the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust, mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.

  19. Estudo transversal das estratégias de tratamento clínico na fibrilação atrial Estudio transversal de las estrategias de tratamiento clínico en la fibrilación atrial Cross-sectional study of treatment strategies on atrial fibrillation

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    Lucas Hollanda Oliveira

    2012-03-01

    Full Text Available FUNDAMENTO: A despeito de elevada prevalência e importância clínica da Fibrilação Atrial (FA, não existem até o momento publicações brasileiras informando o perfil clínico e a estratégia de tratamento (controle de ritmo vs. controle de frequência cardíaca mais utilizada nesse universo de pacientes. OBJETIVO: Avaliar a estratégia de tratamento mais empregada na FA em ambulatório especializado no manejo dessa doença. Secundariamente, procurou-se descrever o perfil clínico dessa população. MÉTODOS: Estudo transversal que avaliou sequencialmente, em 167 portadores de FA, a estratégia de tratamento mais empregada, bem como o perfil clínico desses pacientes. Utilizou-se questionário padronizado para coleta de dados. A análise estatística foi realizada por meio do software SPSS® versão 13.0. RESULTADOS: Nessa população de alto risco para eventos tromboembólicos (61% com score CHADS2 > 2, em que 54% dos indivíduos apresentavam fibrilação atrial paroxística ou persistente, 96,6% utilizavam antagonistas da vitamina K ou AAS, e 76,6% faziam uso de betabloqueador (81,2% frequência x 58,8% ritmo, p 2 (60,5% x 39,5%; p = 0,07 e valvopatias (25,8% x 11,8%; p = 0,08 no segmento de controle da frequência. CONCLUSÃO: Nessa população de alto risco para eventos tromboembólicos, a estratégia de controle de frequência cardíaca foi a mais empregada.FUNDAMENTO: A despecho de la elevada prevalencia y importancia clínica de la Fibrilación Atrial (FA, no existen hasta el momento publicaciones brasileñas informando el perfil clínico y la estrategia de tratamiento (control de ritmo vs. control de frecuencia cardíaca más utilizada en ese universo de pacientes. OBJETIVO: Evaluar la estrategia de tratamiento más empleada en la FA en ambulatorio especializado en el manejo de esa enfermedad. Secundariamente, se buscó describir el perfil clínico de esa población. MÉTODOS: Estudio transversal que evaluó secuencialmente, en 167

  20. Oclusão do apêndice atrial esquerdo com o Amplatzer Cardiac Plug em pacientes com fibrilação atrial

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    Ênio Eduardo Guérios

    2012-06-01

    Full Text Available FUNDAMENTO: A oclusão percutânea do apêndice atrial esquerdo (OAAE surgiu como alternativa à anticoagulação oral (AO para prevenção do acidente vascular cerebral (AVC em pacientes com fibrilação atrial não-valvular (FANV. OBJETIVO: Relatar os resultados imediatos e o seguimento clínico de pacientes submetidos a OAAE com o Amplatzer Cardiac Plug (ACP em um único centro de referência. MÉTODOS: Oitenta e seis pacientes consecutivos com FANV, contra-indicação à AO e escore CHADS2= 2,6±1,2 foram submetidos a OAAE com implante de ACP. Realizou-se seguimento clínico e ecocardiográfico no mínimo 4 meses após o implante. RESULTADOS: Todos os implantes foram guiados apenas por angiografia. O sucesso do procedimento foi de 99% (1 insucesso por tamponamento cardíaco e consequente suspensão da OAAE. Houve 4 complicações maiores (o tamponamento já referido, 2 AVCs transitórios e uma embolização com retirada percutânea da prótese e duas menores (um derrame pericárdico sem tamponamento e uma pequena comunicação interatrial evidenciada no seguimento. Houve 1 óbito hospitalar após 6 dias, não relacionado à intervenção. Todos os outros pacientes receberam alta sem AO. Após seguimento de 25,9 pacientes-ano (69 pacientes não houve AVCs nem embolizações tardias de próteses. O AAE estava completamente ocluído em 97% dos casos. Seis pacientes apresentaram evidência de trombo sobre a prótese, que desapareceram após reinstituição de AO por 3 meses. CONCLUSÃO: OAAE se associa a um alto índice de sucesso, um índice aceitável de complicações e resultados promissores a médio prazo, podendo ser considerada uma alternativa válida à OA na prevenção do AVC em pacientes com FANV.

  1. Dust emission and transport over Iraq associated with the summer Shamal winds

    Science.gov (United States)

    Karam Francis, Diana Bou; Flamant, Cyrille; Chaboureau, Jean-Pierre; Banks, Jamie

    2016-04-01

    In this study, we investigate the diurnal evolution of the summer Shamal wind (a quasi-permanent low-level northwesterly wind feature) and its role in dust emission and transport over Iraq, using ground-based and space-borne observations together with a numerical simulation performed with the mesoscale model Meso-NH. A 6-year dataset from the synoptic stations over Iraq allows establishing the prominence of the link between strong near surface winds and reduced visibility in the summer. The detailed processes at play during Shamal events are explored on the basis of a Meso-NH simulation for a given, representative case study (25 June-3 July 2010). The Shamal exhibits an out-of-phase relationship between the surface wind and winds in the lower troposphere (typically 500 m above ground level), the maximum surface wind speeds being observed during the day while in altitude the maximum wind speeds are observed at night. The daytime near surface winds, at the origin of dust emission, are associated with the downward transfer of momentum from the nocturnal low-level jet to the surface due to turbulent mixing after solar heating commences each day. For the first time, an estimate of the dust load associated with summer Shamal events over Iraq has been made using aerosol optical depths derived from the Spinning Enhanced Visible and Infrared Imager, the Moderate Resolution Imaging Spectroradiometer, and the simulation. The dust load exhibits a large diurnal variability, with a daily minimum value of 1 Tg around 0600 UTC and a daily peak of 2.5 Tg or more around 1500 UTC, and is driven by the diurnal cycle of the near surface wind speed. The daily dust load peak associated with the summer Shamal over Iraq is in the same order of magnitude as those derived from simulations downstream of the Bodélé depression in Chad, known to be the world's largest dust source. Keywords: Dust, Low Level Jet, Shamal winds, Middle East, dust sources.

  2. Prediction of rates of thromboembolic and major bleeding outcomes with dabigatran or warfarin among patients with atrial fibrillation: new initiator cohort study

    Science.gov (United States)

    Franklin, Jessica M; Glynn, Robert J; Schneeweiss, Sebastian; Eddings, Wesley; Gagne, Joshua J

    2016-01-01

    Objectives To compare stratified event rates from randomized controlled trials with predicted event rates from models developed in observational data, and assess their ability to accurately capture observed rates of thromboembolism and major bleeding for patients treated with dabigatran or warfarin as part of routine care. Design New initiator cohort study. Setting Data from United Health (October 2009 to June 2013), a commercial healthcare claims database in the United States. Participants 21 934 adults with atrial fibrillation initiating dabigatran (150 mg dose only) or warfarin treatment as part of routine care. Main outcome measures Predicted annual rates of thromboembolism or major bleeding, based on estimates from randomized controlled trials, models developed in routine care patients, and baseline risk scores (CHADS2, CHA2DS2-VASc, and HAS-BLED). Thromboembolism was a composite outcome, including primary inpatient diagnosis codes for ischemic or ill defined stroke, transient ischemic attack, pulmonary embolism, deep vein thrombosis, and systemic embolism. Major bleeding was a composite outcome including codes occurring in an inpatient setting for hemorrhagic stroke; major upper, lower, or unspecified gastrointestinal bleed; and major urogenital or other bleed. Results 6516 (30%) and 15 418 (70%) of patients initiated dabigatran and warfarin, respectively. Annual event rates per 100 patients were 1.7 for thromboembolism and 4.6 for major bleeding. For thromboembolism, calibration of estimates from randomized controlled trials was similar to calibration for model based predictions; however, trial estimates for major bleeding consistently underestimated the rate of bleeding among patients in routine care. Underestimation of bleeding rates was particularly pronounced in warfarin initiators with high HAS-BLED scores, where event rates were underestimated by up to 4.0 per 100 patient years. Harrell’s c indices for discrimination for thromboembolism or

  3. Outcome of catheter ablation of atrial fibrillation in patients with prior ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    LI Song-nan; KANG Jun-ping; DU Xin; HE Xiao-nan; LONG De-yong; YU Rong-hui; FANG Ri-bo

    2013-01-01

    Background Catheter ablation for atrial fibrillation (AF) has been demonstrated to be effective in a subsets of patients with AF.However,very few data are available in regard to patients with prior history of stroke undergoing catheter ablation.This study aimed to investigate the outcome of catheter ablation in AF patients with prior ischemic stroke.Methods Between January 2008 and December 2011,of 1897 consecutive patients who presented at Beijing An Zhen Hospital for treatment of drug-refractory AF,172 (9.1%) patients in the study population had a history of ischemic stroke.All patients underwent catheter ablation and were followed up to assess maintenance of sinus rhythm and recurrence of symptomatic stroke.Results Among these 1897 patients,1768 (93.2%) who had complete follow-up information for a minimum of six months were included in the final analysis.Patients in the stroke group (group Ⅰ) and the no-stroke group (group Ⅱ) were similar in regards to gender,body mass index (BMI),history of diabetes,type of AF,and left atrial size.The patients in group Ⅰ were older than those in group Ⅱ,and had a higher incidence of hypertension,chronic heart failure,lower left ventricular ejection fraction (LVEF),and higher CHADS2 scores.Six months after ablation,107 (68.6%) patients in group Ⅰ and 1403 (87.1%) in group Ⅱ had discontinued warfarin treatment (P <0.001).During a median follow-up of (633±415)days,65 patients in the group Ⅰ and 638 in group Ⅱ experienced AF recurrence,and five patients in group Ⅰ and 28 in group Ⅱ developed symptomatic stroke.The rates of AF recurrence and recurrent stroke were similar between group Ⅰ and group Ⅱ (41.7% vs.39.6%,P=-0.611; 3.2% vs.1.7%,P=0.219; respectively).Conclusion Catheter ablation of AF in patients with prior stroke is feasible and efficient.

  4. Nigeria.

    Science.gov (United States)

    1987-08-01

    Nigeria, located on the western coast of Africa, is bordered by Cameroon and Chad on the east, by the Gulf of Guinea on the south, by Niger on the north, and by Benin on the west. It is the most populous country in Africa, accounting for 1 in 4 of sub-Saharan Africa's people. While only 25% of Nigerians are urban dwellers, there are 24 cities with populations that exceed 100,000. There is wonderful diversity because of the 250 ethnic groups which comprise Nigeria. The country gained full independence on October 1, 1960 as a federation of 3 regions under a constitution that provided for a parliamentary form of government. This constitution provided a substantial measure of self-government for each of the 3 regions. In 1963, Nigeria proclaimed itself a federal republic and rewrote its constitution; a 4th region was established that same year. In an effort to resolve some of the increased tensions among the ethnic groups, the 4 regions became 12 states; civil war ensued in response to the establishment of the Republic of Biafra. Biafra was defeated and then reconciliation was rapid and effective. Economic development became the focus for Nigeria. Many changes in the government occurred in the years following, and in 1983, there was a military takeover. There are currently 19 states which receive most of their revenue from the federal government according to a formula based on population and other factors. Since 1986, the country has been involved in a public discussion of its political future which will serve as a prelude to the proposed return to civilian rule in 1990. It will hopefully result in the creation of a stable political system. Since the oil boom of the 1970s, the economy of Nigeria has shifted from an agriculturally-based to an oil-based economy. They now rely on oil for more than 95% of export earnings and 70% of federal budget resources. With changes in that market, Nigeria has had to reevaluate their development plans and transportation and

  5. Revisiting sub-Saharan African countries' drug problems: health, social, economic costs, and drug control policy.

    Science.gov (United States)

    Affinnih, Yahya H

    2002-02-01

    This article takes an international perspective on the drug problem in sub-Saharan Africa. This analysis borrows ideas from physical and economic geography as a heuristic device to conceptualize the global narcoscapes in which drug trafficking occurs. Both the legitimate and the illegal drug trade operate within the same global capitalist system and draw on the same technological innovations and business processes. Central to the paper's argument is evidence that sub-Saharan African countries are now integrated into the political economy of drug consumption due to the spill-over effect. These countries are now minor markets for "hard drugs" as the result of the activities of organizations and individual traffickers that use Africa as a staging point in their trade with Europe and the United States. As a result, sub-Saharan African countries have drug consumption problems that were essentially absent prior to 1980, along with associated health, social, and economic costs. The emerging drug problem has forced African countries to develop their own drug control policy. The sub-Saharan African countries mentioned below vary to some extent in the level of drug use and misuse problems: Burundi, Comoros, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Malawi, Mauritius, Mozambique, Reunion, Rwanda, Seychelles, Somalia, Tanzania, Uganda, Zambia, Angola, Cameroon, Central African Republic, Chad, Congo, Congo (Zaire), Equatorial Guinea, Gabon, Sao Tome and Principe, Botswana, Lesotho, Namibia, South Africa, Swaziland, Benin, Burkina Faso, Cape Verde, Cote d'Ivoire, Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo. As part of this effort, African countries are assessing the health, social, and economic costs of drug-use-related problems to pinpoint methods which are both effective and inexpensive, since their budgets for social programs are severely constrained. Many have progressed to the point of adopting anti

  6. The food crisis and environmental conservation in Africa.

    Science.gov (United States)

    Stiles, D; Brennan, R

    1986-11-01

    In spite of good rains in Africa in 1985, 30-35 million people suffered the effects of famine. Much of Africa is still dependent on food aid. The main causes of insufficient food production are land degradation--desertification--and high population growth. Distribution of the US $2.9 billion in food and non-food aid has been hampered by transport and logistical problems. The major challenge for 1986 is non-food support. Only US $460 million (15.3%) of non-food aid had been received as of March. Country profiles of Angola, Chad, Ethiopia, Mozambique, Somalia, Sudan, Lesotho, Mali, Mauritania, Niger, Rwanda, Tanzania, and Zambia show a pattern of high food assistance needs and displaced refugee populations. The 1st 6 of the group suffer from civil strife. There is some good news; e.g. Niger, which is embarking on agressive agricultural development, and Tanzania, which has enjoyed bumper crops, but the crisis is clearly far from over. Few African Governments have been willing to face the population problem; population in the area will probably continue to increase at 3% yearly. It is shown that desertification: reducing the biological potential of the land through over-exploitation, animal husbandry, and deforestation, is a wordwide problem particularly acute in Africa. Lost production totals $26 billion annually. Straightforward cost-benefit analysis of projects to halt or reverse the problem does not adequately take factors such as human attachment to the land into account. Unfortunately halting desertification does not receive the attention it should receive from donor agencies. Investment goes towards high-return projects, e.g. power dams; sugar factories, when a more careful study reveals that returns from afforestations are much more long-term. There has been increased consciousness of the long-term benefits of dryland rehabilitation, which will hopefully impact policy in the future. But since desertification is a self-accelerating process, there is a need for

  7. Cost-effectiveness of dronedarone and standard of care compared with standard of care alone: US results of an ATHENA lifetime model

    Directory of Open Access Journals (Sweden)

    Reynolds MR

    2013-01-01

    Full Text Available Matthew R Reynolds,1 Jonas Nilsson,2 Örjan Åkerborg,2 Mehul Jhaveri,3 Peter Lindgren2,41Beth Israel Deaconess Medical Center, VA Boston Healthcare System, Boston, MA, USA; 2OptumInsight, Stockholm, Sweden; 3sanofi-aventis Inc, Bridgewater, NJ, USA; 4Institute of Environmental Medicine, Karolinska Institute, Stockholm, SwedenBackground: The first antiarrhythmic drug to demonstrate a reduced rate of cardiovascular hospitalization in atrial fibrillation/flutter (AF/AFL patients was dronedarone in a placebo-controlled, double-blind, parallel arm Trial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter (ATHENA trial. The potential cost-effectiveness of dronedarone in this patient population has not been reported in a US context. This study assesses the cost-effectiveness of dronedarone from a US health care payers’ perspective.Methods and results: ATHENA patient data were applied to a patient-level health state transition model. Probabilities of health state transitions were derived from ATHENA and published data. Associated costs used in the model (2010 values were obtained from published sources when trial data were not available. The base-case model assumed that patients were treated with dronedarone for the duration of ATHENA (mean 21 months and were followed over a lifetime. Cost-effectiveness, from the payers' perspective, was determined using a Monte Carlo microsimulation (1 million fictitious patients. Dronedarone plus standard care provided 0.13 life years gained (LYG, and 0.11 quality-adjusted life years (QALYs, over standard care alone; cost/QALY was $19,520 and cost/LYG was $16,930. Compared to lower risk patients, patients at higher risk of stroke (Congestive heart failure, history of Hypertension, Age ≥ 75 years, Diabetes mellitus, and past history of Stroke or transient ischemic attack (CHADS2 scores 3

  8. The burden of malaria in post-emergency refugee sites: A retrospective study

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    Spiegel Paul

    2011-09-01

    Full Text Available Abstract Background Almost two-thirds of refugees, internally displaced persons, returnees and other persons affected by humanitarian emergencies live in malaria endemic regions. Malaria remains a significant threat to the health of these populations. Methods Data on malaria incidence and mortality were analyzed from January 2006 to December 2009 from the United Nations High Commissioner for Refugees Health Information System database collected at sites in Burundi, Chad, Cameroon, Ethiopia, Kenya, Sudan, Tanzania, Thailand, and Uganda. Data from three countries during 2006 and 2007, and all nine countries from 2008 to 2009, were used to describe trends in malaria incidence and mortality. Monthly counts of malaria morbidity and mortality were aggregated into an annual country rate averaged over the study period. Results An average of 1.18 million refugees resided in 60 refugee sites within nine countries with at least 50 cases of malaria per 1000 refugees during the study period 2008-2009. The highest incidence of malaria was in refugee sites in Tanzania, where the annual incidence of malaria was 399 confirmed cases per 1,000 refugees and 728 confirmed cases per 1,000 refugee children younger than five years. Malaria incidence in children younger than five years of age, based on the sum of confirmed and suspected cases, declined substantially at sites in two countries between 2006 and 2009, but a slight increase was reported at sites within four of seven countries between 2008 and 2009. Annual malaria mortality rates were highest in sites in Sudan (0.9 deaths per 1,000 refugees, Uganda and Tanzania (0.7 deaths per 1000 refugees each. Malaria was the cause of 16% of deaths in refugee children younger than five years of age in all study sites. Conclusions These findings represent one of the most extensive reports on malaria among refugees in post-emergency sites. Despite declines in malaria incidence among refugees in several countries, malaria

  9. Klinische Ergebnisse mit Dronedaron (Multaq® bei nicht-permanentem Vorhofflimmern - Resultate des DEMETER-Registers

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    Pürerfellner H

    2015-01-01

    Full Text Available iEinleitung:/i Dronedaron (Multaq®, Sanofi wird als Mehrkanalblocker bei nicht-permanentem Vorhofflimmern (VHF eingesetzt und ist in Österreich seit 02/2010 verfügbar. Wir berichten über die klinischen Resultate aus dem prospektiven DEMETER Register (02/2010– 12/2011.iMethoden:/i Sechs österreichische Kliniken schlossen 94 ambulante oder stationäre Patienten in die Studie ein. Einschlusskriterien waren Erstmanifestation von VHF (2,2 %, paroxysmales VHF (72,3 %, persistierendes VHF (24,4 % und lang anhaltend persistierendes VHF (1,1 %. Zur Baseline (BL wurden EKG-Parameter (Rhythmus, Herzfrequenz, PQ, QTC, Nieren- und Leberwerte, NYHA-Stadien, CHADS2- Scores und echokardiographische Parameter (LVEF, linksatrialer Diameter erfasst und nach 3 sowie 6 Monaten zusammen mit einer Einschätzung der Lebensqualität (QoL hinsichtlich VHF re-evaluiert. iResultate:/i 55 % der Patienten konnten die Studie protokollkonform abschließen, 20 % waren nicht auswertbar („Lost-to- Follow-up“ und bei 15 % wurde ein Abbruch dokumentiert. Der Hauptgrund für einen Studienabbruch war rezidivierendes VHF (75 %; proarrhythmogene Effekte oder Todesfälle traten nicht auf. Die Rate an Rehospitalisierungen war gering (8,3 % und auf VHF-Rezidive beschränkt; über einen Zeitraum von 6 Monaten konnte keine relevante Progression von Sinusrhythmus (SR in persistierendes VHF beobachtet werden. Die Leberwerte und Nierenwerte blieben im Verlauf stabil, Serumkreatinin stieg pharmakodynamisch erwartungsgemäß signifikant an. Relevante EKG-Veränderungen kamen nicht vor, die NYHA-Stadien nahmen von Visite zu Visite signifikant ab, und bereits ab dem ersten Follow-up (FU1 wurde eine signifikant gebesserte QoL angegeben. iSchlussfolgerungen:/i Unter Beobachtung von Klinik, EKG, Serumkreatinin und Leberwerten zeigte sich Dronedaron bei Patienten mit nicht-permanentem VHF ohne rezente kardiale Dekompensation sicher und nebenwirkungsarm in der Anwendung. Zudem kam es zu einer

  10. Exploring drought vulnerability in Africa: an indicator based analysis to be used in early warning systems

    Science.gov (United States)

    Naumann, G.; Barbosa, P.; Garrote, L.; Iglesias, A.; Vogt, J.

    2014-05-01

    We propose a composite drought vulnerability indicator (DVI) that reflects different aspects of drought vulnerability evaluated at Pan-African level for four components: the renewable natural capital, the economic capacity, the human and civic resources, and the infrastructure and technology. The selection of variables and weights reflects the assumption that a society with institutional capacity and coordination, as well as with mechanisms for public participation, is less vulnerable to drought; furthermore, we consider that agriculture is only one of the many sectors affected by drought. The quality and accuracy of a composite indicator depends on the theoretical framework, on the data collection and quality, and on how the different components are aggregated. This kind of approach can lead to some degree of scepticism; to overcome this problem a sensitivity analysis was done in order to measure the degree of uncertainty associated with the construction of the composite indicator. Although the proposed drought vulnerability indicator relies on a number of theoretical assumptions and some degree of subjectivity, the sensitivity analysis showed that it is a robust indicator and hence able of representing the complex processes that lead to drought vulnerability. According to the DVI computed at country level, the African countries classified with higher relative vulnerability are Somalia, Burundi, Niger, Ethiopia, Mali and Chad. The analysis of the renewable natural capital component at sub-basin level shows that the basins with high to moderate drought vulnerability can be subdivided into the following geographical regions: the Mediterranean coast of Africa; the Sahel region and the Horn of Africa; the Serengeti and the Eastern Miombo woodlands in eastern Africa; the western part of the Zambezi Basin, the southeastern border of the Congo Basin, and the belt of Fynbos in the Western Cape province of South Africa. The results of the DVI at the country level were

  11. Exploring drought vulnerability in Africa: an indicator based analysis to inform early warning systems

    Science.gov (United States)

    Naumann, G.; Barbosa, P.; Garrote, L.; Iglesias, A.; Vogt, J.

    2013-10-01

    Drought vulnerability is a complex concept that includes both biophysical and socio-economic drivers of drought impact that determine capacity to cope with drought. In order to develop an efficient drought early warning system and to be prepared to mitigate upcoming drought events it is important to understand the drought vulnerability of the affected regions. We propose a composite Drought Vulnerability Indicator (DVI) that reflects different aspects of drought vulnerability evaluated at Pan-African level in four components: the renewable natural capital, the economic capacity, the human and civic resources, and the infrastructure and technology. The selection of variables and weights reflects the assumption that a society with institutional capacity and coordination, as well as with mechanisms for public participation is less vulnerable to drought; furthermore we consider that agriculture is only one of the many sectors affected by drought. The quality and accuracy of a composite indicator depends on the theoretical framework, on the data collection and quality, and on how the different components are aggregated. This kind of approach can lead to some degree of scepticism; to overcome this problem a sensitivity analysis was done in order to measure the degree of uncertainty associated with the construction of the composite indicator. Although the proposed drought vulnerability indicator relies on a number of theoretical assumptions and some degree of subjectivity, the sensitivity analysis showed that it is a robust indicator and hence able of representing the complex processes that lead to drought vulnerability. According to the DVI computed at country level, the African countries classified with higher relative vulnerability are Somalia, Burundi, Niger, Ethiopia, Mali and Chad. The analysis of the renewable natural capital component at sub-basin level shows that the basins with high to moderate drought vulnerability can be subdivided in three main different

  12. The role of epithelial–mesenchymal transition programming in invasion and metastasis: a clinical perspective

    Directory of Open Access Journals (Sweden)

    Creighton CJ

    2013-07-01

    Full Text Available Chad J Creighton,1–3 Don L Gibbons,4,5 Jonathan M Kurie4 1The Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA; 2Department of Medicine, Baylor College of Medicine, Houston, TX, USA; 3Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; 4Department of Thoracic/Head and Neck Medical Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; 5Department of Molecular and Cellular Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA Abstract: Epithelial–mesenchymal transition (EMT is involved in normal developmental cellular processes, but it may also be co-opted by a subset of cancer cells, to enable them to invade and form metastases at distant sites. Several gene transcription factors regulate EMT, including Snail1, Snail2, Zeb1, Zeb2, and Twist; ongoing studies continue to identify and elucidate other drivers. Specific micro ribonucleic acids (RNAs have also been found to regulate EMT, including the microRNA-200 (miR-200 family, which targets Zeb1/Zeb2. Cancer “stem cells” – with the ability to self-renew and to regenerate all the cell types within the tumor – have been found to express EMT markers, further implicating both cancer stem cells and EMT with metastasis. Microenvironmental cues, including transforming growth factor-β, can direct EMT tumor metastasis, such as by regulating miR-200 expression. In human tumors, EMT markers and regulators may be expressed in a subset of tumor cells, such as in cells at the invasive front or tumor–microenvironment interface, though certain subtypes of cancer can show widespread mesenchymal-like features. In terms of therapeutic targeting of EMT in patients, potential areas of exploration could include targeting the cancer stem cell subpopulation, as well as microRNA-based therapeutics that reintroduce miR-200. This review will examine evidence for a

  13. Forecasting the Depletion of Transboundary Groundwater Resources in Hyper-Arid Environments

    Science.gov (United States)

    Mazzoni, A.; Heggy, E.

    2014-12-01

    The increase in awareness about the overexploitation of transboundary groundwater resources in hyper-arid environments that occurred in the last decades has highlighted the need to better map, monitor and manage these resources. Climate change, economic and population growth are driving forces that put more pressure on these fragile but fundamental resources. The aim of our approach is to address the question of whether or not groundwater resources, especially non-renewable, could serve as "backstop" water resource during water shortage periods that would probably affect the drylands in the upcoming 100 years. The high dependence of arid regions on these resources requires prudent management to be able to preserve their fossil aquifers and exploit them in a more sustainable way. We use the NetLogo environment with the FAO Aquastat Database to evaluate if the actual trends of extraction, consumption and use of non-renewable groundwater resources would remain feasible with the future climate change impacts and the population growth scenarios. The case studies selected are three: the Nubian Sandstone Aquifer System, shared between Egypt, Libya, Sudan and Chad; the North Western Sahara Aquifer System, with Algeria, Tunisia and Libya and the Umm Radhuma Dammam Aquifer, in its central part, shared between Saudi Arabia, Qatar and Bahrain. The reason these three fossil aquifers were selected are manifold. First, they represent properly transboundary non-renewable groundwater resources, with all the implications that derive from this, i.e. the necessity of scientific and socio-political cooperation among riparians, the importance of monitoring the status of shared resources and the need to elaborate a shared management policy. Furthermore, each country is characterized by hyper-arid climatic conditions, which will be exacerbated in the next century by climate change and lead to probable severe water shortage periods. Together with climate change, the rate of population

  14. Discernible rhythm in the spatio/temporal distributions of transatlantic dust

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ami

    2011-08-01

    −1, and 1300 km in total. These rates of northward advance and southern retreat of the dust transport route are in accordance with the simultaneous shift of the Inter Tropical Front.

    Based on cross-correlation analyses, we attribute the observed rhythm to the contrast between the northwestern and southern Saharan dust source spatial distributions. Despite the vast difference in areas, the Bodélé Depression, located in Chad, appears to modulate transatlantic dust patterns about half the time. The proposed partition captures the essence of transatlantic dust climatology and may, therefore, supply a natural temporal framework for dust analysis via models and observations.

  15. Stable isotope analyses of tooth enamel carbonate of large herbivores from the Tugen Hills deposits: Palaeoenvironmental context of the earliest Kenyan hominids

    Science.gov (United States)

    Roche, Damien; Ségalen, Loïc; Senut, Brigitte; Pickford, Martin

    2013-11-01

    Understanding shifts in past climatic and environmental conditions are crucial for throwing light on human evolution. Available reconstructions of the palaeoecology of faunal and floral assemblages indicate that the earliest Kenyan hominids, including Orrorin tugenensis, are associated with forest landscapes. In this study, we present stable isotope data of tooth enamel carbonate of large herbivores associated with these hominids in order further to evaluate their environmental context. Fossil teeth were sampled in the Lukeino Formation (6.1-5.7 Ma, Late Miocene) and the Mabaget Formation (5.3-4.5 Ma, Early Pliocene) at the foot of the Tugen Hills (Great Rift Valley). Despite chemical changes in fossil enamel, preservation of the palaeoenvironmental signals is supported by the difference in δ18O between hippos and terrestrial fauna. Moreover, the giraffid specimen from the Mabaget Formation exhibits one of the highest δ18O values, as expected for a drought-tolerant animal. The δ13C of large herbivores indicates that the earliest Kenyan hominids inhabited a mixed C3-C4 environment as did Ardipithecus (Ethiopia) and Sahelanthropus (Chad), two early putative hominids. The Tugen Hills might have been a wooded grassland with patches of woodland. There is no record of closed-canopy forest at the time of deposition. We emphasize differences in food habits among herbivore groups. Deinotheres, nearly all elephantids and the giraffid individual had a C3 diet which reflected browsing behaviour. The intake of C4 plants prevailed for equids and gomphotheres and was consistent with grazing habits. Most hippos and suids were mixed C3-C4 feeders and consequently were generalist herbivores. Bovids and rhinos had a diet ranging from C3 to C4 plants. Variations in δ13C and δ18O among faunal assemblages suggest changes in local climate and vegetation. Moister conditions likely occurred in the Early Pliocene and the latest Miocene (ca. 5.7 Ma) than before. The C3 plant biomass

  16. Effects of vitamin D and quercetin, alone and in combination, on cardiorespiratory fitness and muscle function in physically active male adults

    Directory of Open Access Journals (Sweden)

    Scholten SD

    2015-07-01

    Full Text Available Shane D Scholten,1 Igor N Sergeev,2 Qingming Song,3 Chad B Birger41Exercise and Sport Sciences, Augustana College, Sioux Falls, 2Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 3Gold Green Farm Corporation, Hammonton, NJ, 4Center for Health Outcomes and Prevention Research, Sanford Research, Sioux Falls, SD, USAIntroduction: Vitamin D and the antioxidant quercetin, are promising agents for improving physical performance because of their possible beneficial effects on muscular strength and cardiorespiratory fitness.Purpose: The purpose of this study was to determine the effects of increased intakes of vitamin D, quercetin, and their combination on antioxidant status, the steroid hormone regulators of muscle function, and measures of physical performance in apparently healthy male adults engaged in moderate-to-vigorous-intensity exercise training.Methods: A total of 40 adult male participants were randomized to either 4,000 IU vitamin D/d, 1,000 mg/d quercetin, vitamin D plus quercetin, or placebo for 8 weeks. Measures of cardiorespiratory fitness and muscle function, blood markers for antioxidant and vitamin D status, and hormones 1,25-dihydroxyvitamin D3 (1,25(OH2D3 and testosterone were measured pre- and postsupplementation.Results: At enrollment, 88.6% of participants were vitamin D sufficient (serum 25-hydroxyvitamin D >50 nmol/L and had normal serum testosterone levels. Supplementation with vitamin D significantly increased serum 25(OHD concentration (by 87.3% in the vitamin D group, P<0.001 and was associated with an increasing trend of testosterone concentration. There were no changes in concentration of 1,25(OH2D3 and markers of antioxidant status associated with vitamin D or quercetin supplementation. No improvements in physical performance measures associated with vitamin D and quercetin supplementation were found.Conclusion: The findings obtained demonstrate that long-term vitamin D and

  17. 2009-2013年脊髓灰质炎疫情分析%Analysis of the world polio cases from 2009 to 2013

    Institute of Scientific and Technical Information of China (English)

    韩辉; 谭克为; 宋亚京; 徐宝梁; 左锋

    2015-01-01

    目的:探讨目前脊髓灰质炎在世界范围内的影响及我国口岸防控脊髓灰质炎疫情的措施。方法收集整理世界卫生组织(WHO)网站内的脊髓灰质炎的相关信息,并对2009-2013年之间脊髓灰质炎疫情进行流行病学统计与分析。结果根据 WHO 所统计的脊髓灰质炎的发病数据,该病的发病情况在近几年得到了有效的控制,但是目前还在尼日利亚、巴基斯坦、阿富汗、索马里和乍得等国持续流行。结论由于我国与持续流行脊灰的国家接壤,并且海外劳务输出和进口贸易的规模逐年增大,导致脊髓灰质炎病毒传入我国的风险较高,加强相关的检疫和监测工作至关重要。%Objective This article observes the world epidemic situation from 2009 to 2013 of poliomyelitis,and explores the present influence of it and the relevant prevention and control measures at frontier ports.Methods This article collects the data and the related situation of the outbreak of poliomyelitis from WHO website,and then carries out the epidemiological statistics and analysis.Results According to the data from WHO,although the on-set of poliomyelitis has been effectively controlled in recent years,there has been sustained prevalence in Nigeria, Pakistan,Afghanistan,Somalia and Chad.Conclusion Because of the contiguity between China and some coun-tries which have sustained prevalence of poliomyelitis and the increasing scale of overseas labor service export and import trade,the risk of the import of polio virus is comparatively high.In order to maintain the “polio -free sta-tus”,the prevention and monitoring of the polio virus still needs to be strengthen at frontier ports.

  18. Imaging and treating tumor vasculature with targeted radiolabeled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Alessandro Ruggiero

    2010-09-01

    Full Text Available Alessandro Ruggiero1*, Carlos H Villa1*, Jason P Holland1, Shanna R Sprinkle1, Chad May2, Jason S Lewis1, David A Scheinberg1, Michael R McDevitt11Departments of Medicine and Radiology, Pharmacology and Molecular Therapeutics, Memorial Sloan-Kettering Cancer Center, New York, USA; 2ImClone Systems, New York, USA; *Ruggiero and Villa contributed equally to this workAbstract: Single wall carbon nanotube (SWCNT constructs were covalently appended with radiometal-ion chelates (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid [DOTA] or desferrioxamine B [DFO] and the tumor neovascular-targeting antibody E4G10. The E4G10 antibody specifically targeted the monomeric vascular endothelial-cadherin (VE-cad epitope expressed in the tumor angiogenic vessels. The construct specific activity and blood compartment clearance kinetics were significantly improved relative to corresponding antibody-alone constructs. We performed targeted radioimmunotherapy with a SWCNT-([225Ac]DOTA(E4G10 construct directed at the tumor vasculature in a murine xenograft model of human colon adenocarcinoma (LS174T. The specific construct reduced tumor volume and improved median survival relative to controls. We also performed positron emission tomographic (PET radioimmunoimaging of the tumor vessels with a SWCNT-([89Zr]DFO(E4G10 construct in the same murine LS174T xenograft model and compared the results to appropriate controls. Dynamic and longitudinal PET imaging of LS174T tumor-bearing mice demonstrated rapid blood clearance (<1 hour and specific tumor accumulation of the specific construct. Incorporation of the SWCNT scaffold into the construct design permitted us to amplify the specific activity to improve the signal-to-noise ratio without detrimentally impacting the immunoreactivity of the targeting antibody moiety. Furthermore, we were able to exploit the SWCNT pharmacokinetic (PK profile to favorably alter the blood clearance and provide an advantage for rapid

  19. Preliminary Note on the Use of Radioisotopes to Study Some Cotton-Plant Pests in Africa

    International Nuclear Information System (INIS)

    The larva of Diparopsis watersi Roth is harmful to the cotton-plant, destroying the flower and the boll. This noctuid, which is practically monophagous, passes the quiescent season either in the ground in the chrysalid-at-diapause form (from 10 November onwards) or in continuing generation (polyvoltine) on plants left standing. Laboratory studies have served to elucidate the main mechanisms initiating and terminating diapause. In the field, the rapid multiplication of the pest during the crop period is due both to univoltine individuals hatching out towards April-May and to non-diapause generations. The respective roles played by these two different sources need to be determined fairly accurately in order to decide which methods of control are appropriate: uprooting of the cotton-plant, destruction of the pupae at diapause in the ground, bringing the crop forward, etc. Radioisotope labelling of larvae coming to maturity at critical periods should make it possible to tackle this problem at the practical level. Preliminary experiments for determining simple labelling techniques have been carried out at Tikem (Republic of Chad). In a first trial, P32 in atomized solution was applied direct to the foliage of young cottonplants. Despite the effects of rain, absorption by the plant reached about 10% in a few hours. Radioactivity is not retained by various phyllophagous larvae (Sylepta derogata, Prodenia litura), but those feeding on the fruit-bearing parts of the plant (Heliothis armigera, Earias insulana, Diparopsis watersi, etc.) are easily detectable three months after the application. In a second trial, P32 and S35 were applied to old cotton-plants immediately before the natural time for Diparopsis to enter diapause. The overall findings give hope of being able to distinguish without too much difficulty, among chrysalid populations taken from the ground, those which fed on the cotton-plant before labelling, and hence which underwent a diapause. A control experiment

  20. Agricultural waste as household fuel: techno-economic assessment of a new rice-husk cookstove for developing countries.

    Science.gov (United States)

    Vitali, Francesco; Parmigiani, Simone; Vaccari, Mentore; Collivignarelli, Carlo

    2013-12-01

    In many rural contexts of the developing world, agricultural residues and the organic fraction of waste are often burned in open-air to clear the lands or just to dispose them. This is a common practice which generates uncontrolled emissions, while wasting a potential energy resource. This is the case of rice husk in the Logone Valley (Chad/Cameroon). In such a context household energy supply is a further critical issue. Modern liquid fuel use is limited and traditional solid fuels (mainly wood) are used for daily cooking in rudimentary devices like 3-stone fires, resulting in low efficiency fuel use, huge health impacts, increasing exploitation stress for the local natural resources. Rice husk may be an alternative fuel to wood for household energy supply. In order to recover such a biomass, the authors are testing a proper stove with an original design. Its lay-out (featuring a metal-net basket to contain the fuel and a chimney to force a natural air draft) allows a mix of combustion/gasification of the biomass occurring in a completely burning fire, appropriate for cooking tasks. According to results obtained with rigorous test protocols (Water Boiling Test), different lay-outs have been designed to improve the performance of the stove. Technical and economic issues have been addressed in the development of such a model; building materials have been chosen in order to guarantee a cost as low as possible, using locally available items. The feasibility of the introduction of the stove in the studied context was assessed through an economic model that keeps into account not only the technology and fuel costs, but also the energy performance. According to the model, the threshold for the trade-off of the stove is the use of rice husk to cover 10-15% of the household energy needs both with traditional fireplaces or with improved efficiency cookstoves. The use of the technology proposed in combination with improved woodstove would provide householders with an

  1. Emigration dynamics in West Africa.

    Science.gov (United States)

    Makinwa-adebusoye, P K

    1995-01-01

    Community. The tolerance level of receiving countries is also linked to their economic situation. Section 9 discusses ethnic upheaval and the flow of refugees generated by Liberia, Chad, Sierra Leone, Togo, and Mauritania. The report ends with a projection of increased migration due to population growth, economic adversity, and political instability. Greater migration may also be generated if ECOWAS is successful in meeting its economic goals for the region. PMID:12347008

  2. Do physiological measures predict selected CrossFit® benchmark performance?

    Directory of Open Access Journals (Sweden)

    Butcher SJ

    2015-07-01

    Full Text Available Scotty J Butcher,1,2 Tyler J Neyedly,3 Karla J Horvey,1 Chad R Benko2,41Physical Therapy, University of Saskatchewan, 2BOSS Strength Institute, 3Physiology, University of Saskatchewan, 4Synergy Strength and Conditioning, Saskatoon, SK, CanadaPurpose: CrossFit® is a new but extremely popular method of exercise training and competition that involves constantly varied functional movements performed at high intensity. Despite the popularity of this training method, the physiological determinants of CrossFit performance have not yet been reported. The purpose of this study was to determine whether physiological and/or muscle strength measures could predict performance on three common CrossFit "Workouts of the Day" (WODs.Materials and methods: Fourteen CrossFit Open or Regional athletes completed, on separate days, the WODs "Grace" (30 clean and jerks for time, "Fran" (three rounds of thrusters and pull-ups for 21, 15, and nine repetitions, and "Cindy" (20 minutes of rounds of five pull-ups, ten push-ups, and 15 bodyweight squats, as well as the "CrossFit Total" (1 repetition max [1RM] back squat, overhead press, and deadlift, maximal oxygen consumption (VO2max, and Wingate anaerobic power/capacity testing.Results: Performance of Grace and Fran was related to whole-body strength (CrossFit Total (r=-0.88 and -0.65, respectively and anaerobic threshold (r=-0.61 and -0.53, respectively; however, whole-body strength was the only variable to survive the prediction regression for both of these WODs (R2=0.77 and 0.42, respectively. There were no significant associations or predictors for Cindy.Conclusion: CrossFit benchmark WOD performance cannot be predicted by VO2max, Wingate power/capacity, or either respiratory compensation or anaerobic thresholds. Of the data measured, only whole-body strength can partially explain performance on Grace and Fran, although anaerobic threshold also exhibited association with performance. Along with their typical training

  3. Implant success and safety of left atrial appendage closure with the WATCHMAN device: peri-procedural outcomes from the EWOLUTION registry

    Science.gov (United States)

    Boersma, Lucas V.A.; Schmidt, Boris; Betts, Timothy R.; Sievert, Horst; Tamburino, Corrado; Teiger, Emmanuel; Pokushalov, Evgeny; Kische, Stephan; Schmitz, Thomas; Stein, Kenneth M.; Bergmann, Martin W.

    2016-01-01

    Aims Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk patients with non-valvular atrial fibrillation. The objective of the multicentre EWOLUTION registry was to obtain clinical data on procedural success and complications, and long-term patient outcomes, including bleeding and incidence of stroke/transient ischaemic attack (TIA). Here, we report on the peri-procedural outcomes of up to 30 days. Methods and results Baseline/implant data are available for 1021 subjects. Subjects in the study were at high risk of stroke (average CHADS2 score: 2.8 ± 1.3, CHA2DS2-VASc: 4.5 ± 1.6) and moderate-to-high risk of bleeding (average HAS-BLED score: 2.3 ± 1.2). Almost half of the subjects (45.4%) had a history of TIA, ischaemic stroke, or haemorrhagic stroke; 62% of patients were deemed unsuitable for novel oral anticoagulant by their physician. The device was successfully deployed in 98.5% of patients with no flow or minimal residual flow achieved in 99.3% of implanted patients. Twenty-eight subjects experienced 31 serious adverse events (SAEs) within 1 day of the procedure. The overall 30-day mortality rate was 0.7%. The most common SAE occurring within 30 days of the procedure was major bleeding requiring transfusion. Incidence of SAEs within 30 days was significantly lower for subjects deemed to be ineligible for oral anticoagulation therapy (OAT) compared with those eligible for OAT (6.5 vs. 10.2%, P = 0.042). Conclusion Left atrial appendage closure with the WATCHMAN device has a high success rate in complete LAAC with low peri-procedural risk, even in a population with a higher risk of stroke and bleeding, and multiple co-morbidities. Improvement in implantation techniques has led to a reduction of peri-procedural complications previously limiting the net clinical benefit of the procedure. PMID:26822918

  4. Monitoring of Oil Exploitation Infrastructure by Combining Unsupervised Pixel-Based Classification of Polarimetric SAR and Object-Based Image Analysis

    Directory of Open Access Journals (Sweden)

    Simon Plank

    2014-12-01

    Full Text Available In developing countries, there is a high correlation between the dependence of oil exports and violent conflicts. Furthermore, even in countries which experienced a peaceful development of their oil industry, land use and environmental issues occur. Therefore, independent monitoring of oil field infrastructure may support problem solving. Earth observation data enables fast monitoring of large areas which allows comparing the real amount of land used by the oil exploitation and the companies’ contractual obligations. The target feature of this monitoring is the infrastructure of the oil exploitation, oil well pads—rectangular features of bare land covering an area of approximately 50–60 m × 100 m. This article presents 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. The method is developed and tested using dual-polarimetric TerraSAR-X imagery acquired over the Doba basin in south Chad. The advantages of PolSAR are independence of the cloud coverage (vs. optical imagery and the possibility of detailed land use classification (vs. single-pol SAR. The PolSAR classification uses the polarimetric Wishart probability density function based on the anisotropy/entropy/alpha decomposition. The object-based post-classification refinement, based on properties of the feature targets such as shape and area, increases the user’s accuracy of the methodology by an order of a magnitude. The final achieved user’s and producer’s accuracy is 59%–71% in each case (area based accuracy assessment. Considering only the numbers of correctly/falsely detected oil well pads, the user’s and producer’s accuracies increase to even 74%–89%. In an iterative training procedure the best suited polarimetric speckle filter and processing parameters of the developed feature extraction procedure are

  5. Projected Zika Virus Importation and Subsequent Ongoing Transmission after Travel to the 2016 Olympic and Paralympic Games - Country-Specific Assessment, July 2016.

    Science.gov (United States)

    Grills, Ardath; Morrison, Stephanie; Nelson, Bradley; Miniota, Jennifer; Watts, Alexander; Cetron, Martin S

    2016-01-01

    Zika virus belongs to the genus Flavivirus of the family Flaviviridae; it is transmitted to humans primarily through the bite of an infected Aedes species mosquito (e.g., Ae. aegypti and Ae. albopictus) (1). Zika virus has been identified as a cause of congenital microcephaly and other serious brain defects (2). As of June 30, 2016, CDC had issued travel notices for 49 countries and U.S. territories across much of the Western hemisphere (3), including Brazil, where the 2016 Olympic and Paralympic Games (Games of the XXXI Olympiad, also known as Rio 2016; Games) will be hosted in Rio de Janeiro in August and September 2016. During the Games, mosquito-borne Zika virus transmission is expected to be low because August and September are winter months in Brazil, when cooler and drier weather typically reduces mosquito populations (4). CDC conducted a risk assessment to predict those countries susceptible to ongoing Zika virus transmission resulting from introduction by a single traveler to the Games. Whereas all countries are at risk for travel-associated importation of Zika virus, CDC estimated that 19 countries currently not reporting Zika outbreaks have the environmental conditions and population susceptibility to sustain mosquito-borne transmission of Zika virus if a case were imported from infection at the Games. For 15 of these 19 countries, travel to Rio de Janeiro during the Games is not estimated to increase substantially the level of risk above that incurred by the usual aviation travel baseline for these countries. The remaining four countries, Chad, Djibouti, Eritrea, and Yemen, are unique in that they do not have a substantial number of travelers to any country with local Zika virus transmission, except for anticipated travel to the Games. These four countries will be represented by a projected, combined total of 19 athletes (plus a projected delegation of about 60 persons), a tiny fraction of the 350,000-500,000 visitors expected at the Games.* Overall

  6. Assessment of human resources for health using cross-national comparison of facility surveys in six countries

    Directory of Open Access Journals (Sweden)

    Dal Poz Mario R

    2009-03-01

    Full Text Available Abstract Background Health facility assessments are being increasingly used to measure and monitor indicators of health workforce performance, but the global evidence base remains weak. Partly this is due to the wide variability in assessment methods and tools, hampering comparability across and within countries and over time. The World Health Organization coordinated a series of facility-based surveys using a common approach in six countries: Chad, Côte d'Ivoire, Jamaica, Mozambique, Sri Lanka and Zimbabwe. The objectives were twofold: to inform the development and monitoring of human resources for health (HRH policy within the countries; and to test and validate the use of standardized facility-based human resources assessment tools across different contexts. Methods The survey methodology drew on harmonized questionnaires and guidelines for data collection and processing. In accordance with the survey's dual objectives, this paper presents both descriptive statistics on a number of policy-relevant indicators for monitoring and evaluation of HRH as well as a qualitative assessment of the usefulness of the data collection tool for comparative analyses. Results The findings revealed a large diversity in both the organization of health services delivery and, in particular, the distribution and activities of facility-based health workers across the sampled countries. At the same time, some commonalities were observed, including the importance of nursing and midwifery personnel in the skill mix and the greater tendency of physicians to engage in dual practice. While the use of standardized questionnaires offered the advantage of enhancing cross-national comparability of the results, some limitations were noted, especially in relation to the categories used for occupations and qualifications that did not necessarily conform to the country situation. Conclusion With increasing experience in health facility assessments for HRH monitoring comes

  7. The effect of adding ready-to-use supplementary food to a general food distribution on child nutritional status and morbidity: a cluster-randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Lieven Huybregts

    Full Text Available BACKGROUND: Recently, operational organizations active in child nutrition in developing countries have suggested that blanket feeding strategies be adopted to enable the prevention of child wasting. A new range of nutritional supplements is now available, with claims that they can prevent wasting in populations at risk of periodic food shortages. Evidence is lacking as to the effectiveness of such preventive interventions. This study examined the effect of a ready-to-use supplementary food (RUSF on the prevention of wasting in 6- to 36-mo-old children within the framework of a general food distribution program. METHODS AND FINDINGS: We conducted a two-arm cluster-randomized controlled pragmatic intervention study in a sample of 1,038 children aged 6 to 36 mo in the city of Abeche, Chad. Both arms were included in a general food distribution program providing staple foods. The intervention group was given a daily 46 g of RUSF for 4 mo. Anthropometric measurements and morbidity were recorded monthly. Adding RUSF to a package of monthly household food rations for households containing a child assigned to the intervention group did not result in a reduction in cumulative incidence of wasting (incidence risk ratio: 0.86; 95% CI: 0.67, 1.11; p = 0.25. However, the intervention group had a modestly higher gain in height-for-age (+0.03 Z-score/mo; 95% CI: 0.01, 0.04; p<0.001. In addition, children in the intervention group had a significantly higher hemoglobin concentration at the end of the study than children in the control group (+3.8 g/l; 95% CI: 0.6, 7.0; p = 0.02, thereby reducing the odds of anemia (odds ratio: 0.52; 95% CI: 0.34, 0.82; p = 0.004. Adding RUSF also resulted in a significantly lower risk of self-reported diarrhea (-29.3%; 95% CI: 20.5, 37.2; p<0.001 and fever episodes (-22.5%; 95% CI: 14.0, 30.2; p<0.001. Limitations of this study include that the projected sample size was not fully attained and that significantly fewer

  8. The role of electrophilic species in the Fischer-Tropsch reaction.

    Science.gov (United States)

    Maitlis, Peter M; Zanotti, Valerio

    2009-04-01

    The heterogeneously catalysed Fischer-Tropsch (FT) synthesis converts syngas (CO+H2) into long chain hydrocarbons and is a key step in the economically important transformation of natural gas, coal, or biomass into liquid fuels, such as diesel. Catalyst surface studies indicate that the FT reaction starts when CO is activated at imperfections on the surfaces of late transition metals (Fe, Ru, Co, or Rh) and at interfaces with "islands" of promoters (Lewis acid oxides such as alumina or titania). Activation involves CO cleavage to generate a surface carbide, C(ad), which is sequentially hydrogenated to CHx(ad) species (x=1-4). An overview of practical aspects of the FT synthesis is followed by a discussion of the chief mechanisms that have been proposed for the formation of 1-alkenes by polymerisation of surface C1 species. These mechanisms have traditionally postulated rather non-polar intermediates, such as CH2(ad) and CH3(ad). However, electrophiles and nucleophiles are well-known to play key roles in the reactions of organic and organometallic compounds, and also in many reactions homogeneously catalysed by soluble metal complexes, including olefin polymerisation. We have now extended these concepts to the Fischer-Tropsch reaction, and show that the polymerisation reactions at polarising surfaces, such as oxide-metal interfaces, can be understood if the reactive chain carrier is an electrophilic species, such as the cationic methylidyne, CH(delta+)(ad). It is proposed that the key coupling step in C-C bond formation involves the interaction of the electrophilic methylidyne with an alkylidene (RCH(ad), R=H, alkyl), followed by an H-transfer to generate the homologous alkylidene: CHdelta+(ad)+RCH(ad)-->RCHCH(ad) and RCHCH(ad)+H(ad)-->RCH2CH(ad). If the reactions occur on non-polarising surfaces, an alternative C-C bond forming reaction such as the alkenyl+methylene, RCH=CH(ad)+CH2(ad)-->RCH=CHCH2(ad), can take place. This approach explains important aspects of the

  9. The project RUSSADE: geoethic education to face environmental problems in the Sahel

    Science.gov (United States)

    Ferrero, Elena; Semita, Carlo

    2016-04-01

    management and bio and geo-preservation represented by the functions of the protected areas. The theoretical approach of these issues is enhanced by practical experiences and visits to emblematic situations and structures in Niger territory, taking care to contextualize them with the local needs and integrating the experience and skills of partner teachers of Niger, Chad, Burkina Faso and Italy). The students work through individual internships (for example internships on bio-digesters) that give rise to a report to be presented at the end of the Master. It is expected to publish the various reports on the appropriate magazines as well as on the websites of CISAO and of the involved universities, to give the best diffusion to the achieved results and to develop the potential applications in the Sahelian countries.

  10. Exploring drought vulnerability in Africa: an indicator based analysis to inform early warning systems

    Directory of Open Access Journals (Sweden)

    G. Naumann

    2013-10-01

    Full Text Available Drought vulnerability is a complex concept that includes both biophysical and socio-economic drivers of drought impact that determine capacity to cope with drought. In order to develop an efficient drought early warning system and to be prepared to mitigate upcoming drought events it is important to understand the drought vulnerability of the affected regions. We propose a composite Drought Vulnerability Indicator (DVI that reflects different aspects of drought vulnerability evaluated at Pan-African level in four components: the renewable natural capital, the economic capacity, the human and civic resources, and the infrastructure and technology. The selection of variables and weights reflects the assumption that a society with institutional capacity and coordination, as well as with mechanisms for public participation is less vulnerable to drought; furthermore we consider that agriculture is only one of the many sectors affected by drought. The quality and accuracy of a composite indicator depends on the theoretical framework, on the data collection and quality, and on how the different components are aggregated. This kind of approach can lead to some degree of scepticism; to overcome this problem a sensitivity analysis was done in order to measure the degree of uncertainty associated with the construction of the composite indicator. Although the proposed drought vulnerability indicator relies on a number of theoretical assumptions and some degree of subjectivity, the sensitivity analysis showed that it is a robust indicator and hence able of representing the complex processes that lead to drought vulnerability. According to the DVI computed at country level, the African countries classified with higher relative vulnerability are Somalia, Burundi, Niger, Ethiopia, Mali and Chad. The analysis of the renewable natural capital component at sub-basin level shows that the basins with high to moderate drought vulnerability can be subdivided in three

  11. A REVISION OF THE PACHNEPHORUS FROM THE AFROTROPICAL REGION (COLEOPTERA, CHRYSOMELIDAE

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    Stefano Zoia

    2007-04-01

    Full Text Available A revision of the genus Pachnephorus Chevrolat, 1837 from the Afrotropical Region is given and a key to the species is provided. Types of all the previously known taxa have been studied and redescribed; 40 new taxa are described and illustrated: P. achardi n. sp. (Mali, P. aequatorianus n. sp. (Rep. Pop. Congo, P. aethiopicus n. sp. (Etiopia, P. baehri n. sp. (Namibia, P. balyi n. sp. (Angola, P. beharui n. sp. (Etiopia, P. bertiae n. sp. (Madagascar, P. bezdeki n. sp. (Rep. Pop. Congo, P. bracarumvestitus n. sp. (Rep. Pop. Congo, P. bryanti n. sp. (Mali, P. burgeoni n. sp. (Natal, P. camerun­ensis n. sp. (Camerun, P. cristiani n. sp. (Namibia, P. crocodilinus n. sp. (Zambia, P. daccordii n. sp. (Yemen, P. danielssoni n. sp. (Sierra Leone, P. danielssoni congoanus n. ssp. (Rep. Pop. Congo, P. demeyeri n. sp. (Rep. Pop. Congo, P. episternalis n. sp. (Madagascar, P. fabianae n. sp. (Congo, P. fasciatus occidentalis n. ssp. (Nigeria, P. gardinii n. sp. (Etiopia, P. gerstaeckeri n. sp. (Namibia, P. grobbelaarae n. sp. (South Africa, P. hajeki n. sp. (Madagascar, P. lopatini n. sp. (Senegal, P. malicus n. sp. (Mali, P. maroantsetranus n. sp. (Madagascar, P. medvedevi n. sp. (Zambia, P. mo­seykoi n. sp. (Chad, P. pacificus n. sp. (Central Afr. Rep., P. parentorum n. sp. (Ghana, P. poggii n. sp. (Somalia, P. regalini n. sp. (Zambia, P. rigatoi n. sp. (Kenya, P. sas­sii n. sp. (Guinea Bissau, P. shuteae n. sp. (Rep. South Africa, P. sprecherae n. sp. (Madagascar, P. uhligi n. sp. (Namibia, P. willersi n. sp. (Namibia. The lectoypes of P. conspersus Gerstaecker, 1871, P. senegalensis Achard, 1914, P. latior Pic, 1921 and P. testaceipes Fairmaire, 1880 are designated. A new synonymy (P. costatus Achard, 1914 n. syn. of P. torridus Baly, 1878 and a nomenclatural change (Mecistes lineatus (Pic, 1921 n. comb. for Pachnephorus lineatus Pic, 1921 are proposed; the Lectotypes of M. lineatus and of M. flavipes (Gerstaecker, 1855 are designated.

  12. Determinants of compliance with anti-vectorial protective measures among non-immune travellers during missions to tropical Africa

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    Briolant Sébastien

    2011-08-01

    Full Text Available Abstract Background The effectiveness of anti-vectorial malaria protective measures in travellers and expatriates is hampered by incorrect compliance. The objective of the present study was to identify the determinants of compliance with anti-vectorial protective measures (AVPMs in this population that is particularly at risk because of their lack of immunity. Methods Compliance with wearing long clothing, sleeping under insecticide-impregnated bed nets (IIBNs and using insect repellent was estimated and analysed by questionnaires administered to 2,205 French military travellers from 20 groups before and after short-term missions (approximately four months in six tropical African countries (Senegal, Ivory Coast, Chad, Central African Republic, Gabon and Djibouti. For each AVPM, the association of "correct compliance" with individual and collective variables was investigated using random-effect mixed logistic regression models to take into account the clustered design of the study. Results The correct compliance rates were 48.6%, 50.6% and 18.5% for wearing long clothing, sleeping under bed nets and using repellents, respectively. Depending on the AVPM, correct compliance was significantly associated with the following factors: country, older than 24 years of age, management responsibilities, the perception of a personal malaria risk greater than that of other travellers, the occurrence of life events, early bedtime (i.e., before midnight, the type of stay (field operation compared to training, the absence of medical history of malaria, the absence of previous travel in malaria-endemic areas and the absence of tobacco consumption. There was no competition between compliance with the different AVPMs or between compliance with any AVPM and malaria chemoprophylaxis. Conclusion Interventions aimed at improving compliance with AVPMs should target young people without management responsibilities who are scheduled for non-operational activities in

  13. Predicting the impacts of fishing canals on Floodplain Dynamics in Northern Cameroon using a small-scale sub-grid hydraulic model

    Science.gov (United States)

    Shastry, A. R.; Durand, M. T.; Fernandez, A.; Hamilton, I.; Kari, S.; Labara, B.; Laborde, S.; Mark, B. G.; Moritz, M.; Neal, J. C.; Phang, S. C.

    2015-12-01

    Modeling Regime Shifts in the Logone floodplain (MORSL) is an ongoing interdisciplinary project at The Ohio State University studying the ecological, social and hydrological system of the region. This floodplain, located in Northern Cameroon, is part of the Lake Chad basin. Between September and October the floodplain is inundated by the overbank flow from the Logone River, which is important for agriculture and fishing. Fishermen build canals to catch fish during the flood's recession to the river by installing fishnets at the intersection of the canals and the river. Fishing canals thus connect the river to natural depressions of the terrain, which act as seasonal ponds during this part of the year. Annual increase in the number of canals affect hydraulics and hence fishing in the region. In this study, the Bara region (1 km2) of the Logone floodplain, through which Lorome Mazra flows, is modeled using LISFLOOD-FP, a raster-based model with sub-grid parameterizations of canals. The aim of the study is to find out how the small-scale, local features like canals and fishnets govern the flow, so that it can be incorporated in a large-scale model of the floodplain at a coarser spatial resolution. We will also study the effect of increasing number of canals on the flooding pattern. We use a simplified version of the hydraulic system at a grid-cell size of 30-m, using synthetic topography, parameterized fishing canals, and representing fishnets as trash screens. The inflow at Bara is obtained from a separate, lower resolution (1-km grid-cell) model run, which is forced by daily discharge records obtained from Katoa, located about 25-km to the south of Bara. The model appropriately captures the rise and recession of the annual flood, supporting use of the LISFLOOD-FP approach. Predicted water levels at specific points in the river, the canals, the depression and the floodplain will be compared to field measured heights of flood recession in Bara, November 2014.

  14. Flood monitoring for ungauged rivers: the power of combining space-based monitoring and global forecasting models

    Science.gov (United States)

    Revilla-Romero, Beatriz; Netgeka, Victor; Raynaud, Damien; Thielen, Jutta

    2013-04-01

    Flood warning systems typically rely on forecasts from national meteorological services and in-situ observations from hydrological gauging stations. This capacity is not equally developed in flood-prone developing countries. Low-cost satellite monitoring systems and global flood forecasting systems can be an alternative source of information for national flood authorities. The Global Flood Awareness System (GloFAS) has been develop jointly with the European Centre for Medium-Range Weather Forecast (ECMWF) and the Joint Research Centre, and it is running quasi operational now since June 2011. The system couples state-of-the art weather forecasts with a hydrological model driven at a continental scale. The system provides downstream countries with information on upstream river conditions as well as continental and global overviews. In its test phase, this global forecast system provides probabilities for large transnational river flooding at the global scale up to 30 days in advance. It has shown its real-life potential for the first time during the flood in Southeast Asia in 2011, and more recently during the floods in Australia in March 2012, India (Assam, September-October 2012) and Chad Floods (August-October 2012).The Joint Research Centre is working on further research and development, rigorous testing and adaptations of the system to create an operational tool for decision makers, including national and regional water authorities, water resource managers, hydropower companies, civil protection and first line responders, and international humanitarian aid organizations. Currently efforts are being made to link GloFAS to the Global Flood Detection System (GFDS). GFDS is a Space-based river gauging and flood monitoring system using passive microwave remote sensing which was developed by a collaboration between the JRC and Dartmouth Flood Observatory. GFDS provides flood alerts based on daily water surface change measurements from space. Alerts are shown on a

  15. Partitioned Waveform Inversion Applied to Eurasia and Northern Africa

    Energy Technology Data Exchange (ETDEWEB)

    bedle, H; Matzel, E; Flanagan, M

    2006-07-27

    model. The model now extends as far east in Africa to cover Chad and Niger, and reaches south to cover Zambia. The model is also stretched eastward to cover the eastern half of India, and northward to cover the southern portion of Scandinavia.

  16. Radiative heating rates profiles associated with a springtime case of Bodélé and Sudan dust transport over West Africa

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    C. Lema^itre

    2010-09-01

    Full Text Available The radiative heating rate due to mineral dust over West Africa is investigated using the radiative code STREAMER, as well as remote sensing and in situ observations gathered during the African Monsoon Multidisciplinary Analysis Special Observing Period (AMMA SOP. We focus on two days (13 and 14 June 2006 of an intense and long lasting episode of dust being lifted in remote sources in Chad and Sudan and transported across West Africa in the African easterly jet region, during which airborne operations were conducted at the regional scale, from the southern fringes of the Sahara to the Gulf of Guinea. Profiles of heating rates are computed from airborne LEANDRE 2 (Lidar Embarqué pour l'étude de l'Atmosphère: Nuages Dynamique, Rayonnement et cycle de l'Eau and space-borne CALIOP (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations lidar observations using two mineral dust model constrained by airborne in situ data and ground-based sunphotometer obtained during the campaign. Complementary spaceborne observations (from the Moderate-resolution Imaging Spectroradiometer-MODIS and in-situ observations such as dropsondes are also used to take into account the infrared contribution of the water vapour. We investigate the variability of the heating rate on the vertical within a dust plume, as well as the contribution of both shortwave and longwave radiation to the heating rate and the radiative heating rate profiles of dust during daytime and nighttime. The sensitivity of the so-derived heating rate is also analyzed for some key variables for which the associated uncertainties may be large. During daytime, the warming associated with the presence of dust was found to be between 1.5 K day−1 and 4 K day−1, on average, depending on altitude and latitude. Strong warming (i.e. heating rates as high as 8 K day−1 was also observed locally in some limited part of the dust plumes. The uncertainty on the

  17. Production zones and systems, markets, benefits and constraints of shea (Vitellaria paradoxa Gaertn butter processing

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    Bup Divine Nde

    2014-03-01

    Full Text Available The shea tree is a multipurpose tree crop indigenous to Sub Saharan African. The tree is highly cherished for the oil that is extracted from its kernels and used nationally and internationally in cosmetics, pharmaceutics and in chocolate formulations. The processing and sales represent significant income earning opportunities for rural women who are the main stakeholders in the production chain. Shea nuts and its products are listed among the top ten Non-Traditional Exports of Ghana. In Burkina Faso it is the fourth most important export crop after gold, cotton and livestock and makes a contribution of about 6 million USD to the national economy. Today the shea tree is the second most important oil crop in Africa after the palm nut tree. About 500 million shea trees grow in Africa which has the potential of producing shea nuts worth about 150 million USD yearly. This represents substantial earnings for the Sub-Saharan African economies when fully exploited. Shea trees grow in 21 Sub-Saharan African countries that can be grouped into 3 zones following their potentials for shea nut production per year: high production zone comprising of Benin, Burkina Faso, Cote D’Ivoire Ghana, Mali, Nigeria, Sudan and Uganda that have potentials of producing 70 000–300 000 tons per year; average production zone comprising of Cameroon, Chad, Central African Republic, Guinea Conakry, Senegal and Togo with potentials of 10 000–70 000 tons per year and low production zones made up of the Democratic Republic of Congo, Ethiopia, Gambia, Guinea Bissau, Niger and Sierra Leone with yearly production potentials less than 10 000 metric tons. Though semi mechanized and some few fully mechanized productions methods are employed in the major shea producing countries of West Africa, most of the rural women still used traditional processing procedures. Major importers of shea are European Union, Japan and the USA. The sector is still constrained by lack of

  18. Novel nonpharmacologic approaches for stroke prevention in atrial fibrillation: results from clinical trials

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    Proietti R

    2015-01-01

    available technologies for percutaneous LAA closure, as well as a summary of the published trials concerning their safety and efficacy in reducing stroke risk in AF. Keywords: left atrial appendage closure, atrial fibrillation, CHADS

  19. Sensitivity of desert dust emission modelling to horizontal resolution: the example of the Bodélé Depression

    Science.gov (United States)

    Bouet, Christel; Cautenet, Guy; Marticorena, Béatrice; Bergametti, Gilles; Minvielle, Fanny; Schmechtig, Catherine; Laurent, Benoit

    2010-05-01

    Atmospheric aerosols are known to play an important role in the Earth's climate system. However, the quantification of aerosol radiative impact on the Earth's radiative budget is very complex because of the high variability in space and time of aerosol mass and particle number concentrations, and optical properties as well. In many regions, like in desert regions, dust is the largest contribution to aerosol optical thickness [Tegen et al., 1997]. Consequently, it appears fundamental to well represent mineral dust emissions to reduce uncertainties concerning aerosol radiative impact on the Earth's radiative budget. Recently, several studies (e.g. Prospero et al. [2002]) underlined that the Bodélé depression, in northern Chad, is probably the most important source of mineral dust in the world. However many models fail in simulating these large dust emissions. Indeed, dust emission is a threshold phenomenon mainly driven by the intensity of surface wind velocity. Realistic estimates of dust emissions then rely on the quality and accuracy of the surface wind fields. Koren and Kaufman [2004] showed that the reanalysis data (NCEP), which can be used as input data in numerical models, underestimates surface wind velocity in the Bodélé Depression by up to 50%. Such an uncertainty on surface wind velocity cannot allow an accurate simulation of the dust emission. In mesoscale meteorological models, global reanalysis datasets are used to initialize and laterally nudge the models that compute meteorological parameters (like wind velocity) with a finer spatial and temporal resolutions. The question arises concerning the precision of the wind speeds calculated by these models. Using the Regional Atmospheric Modeling System (RAMS, Cotton et al. [2003]) coupled online with the dust production model developed by Marticorena and Bergametti [1995] and recently improved by Laurent et al. [2008] for Africa, the influence of the horizontal resolution of the mesoscale meteorological

  20. AFib treatment: general population.

    Science.gov (United States)

    Rothman, Steven A

    2014-04-01

    bleeding. This is discussed in the context of the new NOACs (discussed in the next review), including addressing what physicians should do if patients move from warfarin to one of the NOACs or vice versa. A final challenge for physicians treating patients with AFib has been the often mistaken belief that patients are at a low-risk status, and this review concludes with an overview of the use of the CHADS2 versus the CHA2DS2-VASc risk scoring systems, including why CHA2DS2-VASc provides a better assessment of which patients are or are not at low risk. PMID:24655743

  1. Comparison of Characteristics and Outcomes of Dabigatran Versus Warfarin in Hypertensive Patients With Atrial Fibrillation (from the RE-LY Trial).

    Science.gov (United States)

    Nagarakanti, Rangadham; Wallentin, Lars; Noack, Herbert; Brueckmann, Martina; Reilly, Paul; Clemens, Andreas; Connolly, Stuart J; Yusuf, Salim; Ezekowitz, Michael D

    2015-10-15

    Hypertension is frequent in patients with atrial fibrillation (AF) and is an independent risk factor for stroke. The Randomized Evaluation of Long Term Anticoagulant TherapY (RE-LY) trial found dabigatran 110 mg (D110) and 150 mg twice daily (D150) noninferior or superior to warfarin for stroke reduction in patients with AF, with either a reduction (D110) or similar rates (D150) of major bleeding. Baseline characteristics and outcomes were compared in patients with and without hypertension. The quality of blood pressure control was also assessed. In RE-LY, 14,283 patients (78.9%) had hypertension. The mean blood pressure at baseline was 132.6 ± 17.6/77.7 ± 10.6 and 124.8 ± 16.7/74.6 ± 10.0 mm Hg for patients with and without hypertension, respectively. More patients with hypertension were diabetic (25.6% vs 14.8%, p warfarin were similar (p = nonsignificant) in hypertensive (stroke/systemic embolism rate of 1.47%, 1.20%, and 1.81% and major bleed rate of 2.89%, 3.70%, and 3.69% in the D110, D150, and W, respectively) and normotensive patients (stroke/systemic embolism rate of 1.79%, 0.78%, and 1.36% and major bleed rate of 2.84%, 2.37%, and 3.03% per year in the D110, D150, and W, respectively). Hypertensive patients had more major bleeds (3.39% vs 2.76%; p = 0.007). Intracranial bleeds were similar (0.47% vs 0.31%; p = 0.12). In conclusion, patients with hypertension in RE-LY were more likely female, diabetic, with a greater CHADS2 and CHA2DS2-VASc scores. Blood pressure control in RE-LY was excellent. The benefits of dabigatran over warfarin, including a substantial reduction of intracranial hemorrhage, were similar in both hypertensive and non-hypertensive patients. PMID:26282726

  2. Non-Vitamin K Antagonist Oral Anticoagulants and Antiplatelet Therapy for Stroke Prevention in Patients With Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Kumar, Shashi; Danik, Stephan B; Altman, Robert K; Barrett, Conor D; Lip, Gregory Y H; Chatterjee, Saurav; Roubin, Gary S; Natale, Andrea; Danik, Jacqueline S

    2016-01-01

    Non-vitamin K antagonist oral anticoagulants (NOACs) are frequently used to prevent stroke in patients with atrial fibrillation. These patients are often also on aspirin or other antiplatelet agents. It is possible that treatment with both NOACs and aspirin or other antiplatelet drug may be effective in decreasing stroke, but data are sparse regarding the efficacy and safety of using both agents for stroke prevention. To address these issues, data were pooled from the 4 recent randomized, controlled trials of NOACs: apixaban, rivaroxaban, dabigatran, and edoxaban, which included 42,411 patients; 14,148 (33.4%) were also on aspirin or other antiplatelet drug. The number of thromboembolic events among participants on NOAC and aspirin/antiplatelet was compared with the number of events in patients on NOAC alone. Bleeding rates were also compared between those on NOAC + aspirin/antiplatelet and on NOAC alone. These results were compared with thromboembolic and bleeding events in the warfarin + aspirin/antiplatelet versus warfarin alone. No greater risk for thromboembolism was seen in patients on NOACs compared with patients on both NOACs and aspirin/antiplatelet drug. In this nonrandomized comparison, there was initially a signal toward higher thromboembolic rates among NOAC users also on aspirin/antiplatelet drugs (relative risk, 1.16; 95% confidence intervals, 1.05, 1.29) when compared with NOAC alone. This likely reflected the higher CHADS2 scores of those on aspirin/antiplatelet drugs. When the analysis was limited to studies that included aspirin rather than other antiplatelet drugs, no difference was seen for thromboembolic rates comparing dual therapy to NOAC alone (relative risk, 1.02; 95% confidence intervals, 0.90, 1.15). Higher rates of bleeding were seen with aspirin/antiplatelet drug in conjunction with NOAC. In this meta-analysis and nonrandomized comparison of aspirin/antiplatelet users and nonusers also on anticoagulation, there was no additional

  3. Cost-effectiveness of dabigatran versus genotype-guided management of warfarin therapy for stroke prevention in patients with atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Joyce H S You

    Full Text Available BACKGROUND: Dabigatran is associated with lower rate of stroke comparing to warfarin when anticoagulation control is sub-optimal. Genotype-guided warfarin dosing and management may improve patient-time in target range (TTR and therefore affect the cost-effectiveness of dabigatran compared with warfain. We examined the cost-effectiveness of dabigatran versus warfarin therapy with genotype-guided management in patients with atrial fibrillation (AF. METHODOLOGY/PRINCIPAL FINDINGS: A Markov model was designed to compare life-long economic and treatment outcomes of dabigatran (110 mg and 150 mg twice daily, warfarin usual anticoagulation care (usual AC with mean TTR 64%, and genotype-guided anticoagulation care (genotype-guided AC in a hypothetical cohort of AF patients aged 65 years old with CHADS(2 score 2. Model inputs were derived from literature. The genotype-guided AC was assumed to achieve TTR = 78.9%, adopting the reported TTR achieved by warfarin service with good anticoagulation control in literature. Outcome measure was incremental cost per quality-adjusted life-year (QALY gained (ICER from perspective of healthcare payers. In base-case analysis, dabigatran 150 mg gained higher QALYs than genotype-guided AC (10.065QALYs versus 9.554QALYs at higher cost (USD92,684 versus USD85,627 with ICER = USD13,810. Dabigatran 110 mg and usual AC gained less QALYs but cost more than dabigatran 150 mg and genotype-guided AC, respectively. ICER of dabigatran 150 mg versus genotype-guided AC would be >USD50,000 (and genotype-guided AC would be most cost-effective when TTR in genotype-guided AC was >77% and utility value of warfarin was the same or higher than that of dabigatran. CONCLUSIONS/SIGNIFICANCE: The likelihood of genotype-guided anticoagulation service to be accepted as cost-effective would increase if the quality of life on warfarin and dabigatran therapy are compatible and genotype-guided service achieves high TTR (>77%.

  4. Delivering High-Quality Family Planning Services in Crisis-Affected Settings I: Program Implementation

    Science.gov (United States)

    Curry, Dora Ward; Rattan, Jesse; Nzau, Jean Jose; Giri, Kamlesh

    2015-01-01

    ABSTRACT In 2012, about 43 million women of reproductive age experienced the effects of conflict. Provision of basic sexual and reproductive health services, including family planning, is a recognized right and need of refugees and internally displaced people, but funding and services for family planning have been inadequate. This article describes lessons learned during the first 2.5 years of implementing the ongoing Supporting Access to Family Planning and Post-Abortion Care in Emergencies (SAFPAC) initiative, led by CARE, which supports government health systems to deliver family planning services in 5 crisis-affected settings (Chad, Democratic Republic of the Congo, Djibouti, Mali, and Pakistan). SAFPAC's strategy focuses on 4 broad interventions drawn from public health best practices in more stable settings: competency-based training for providers, improved supply chain management, regular supervision, and community mobilization to influence attitudes and norms related to family planning. Between July 2011 and December 2013, the initiative reached 52,616 new users of modern contraceptive methods across the 5 countries (catchment population of 698,053 women of reproductive age), 61% of whom chose long-acting methods of implants or intrauterine devices. Prudent use of data to inform decision making has been an underpinning to the project's approach. A key approach to ensuring sustained ability to train and supervise new providers has been to build capacity in clinical skills training and supervision by establishing in-country training centers. In addition, monthly supervision using simple checklists has improved program and service quality, particularly with infection prevention procedures and stock management. We have generally instituted a “pull” system to manage commodities and other supplies, whereby health facilities place resupply orders as needed based on actual consumption patterns and stock-alert thresholds. Finally, reaching the community with

  5. Radiative forcing associated with a springtime case of Bodélé and Sudan dust transport over West Africa

    Directory of Open Access Journals (Sweden)

    C. Lemaître

    2010-04-01

    Full Text Available The radiative forcing due to mineral dust over West Africa is investigated using the radiative code STREAMER, as well as remote sensing and in situ observations gathered during the African Monsoon Multidisciplinary Analysis Special Observing Period (AMMA SOP. We focus on two days (13 and 14 June 2006 of an intense and long-lasting episode of dust being lifted in remote sources in Chad and Sudan and transported across West Africa in the African easterly jet region, during which airborne operations were conducted at the regional scale, from the southern fringes of the Sahara to the Gulf of Guinea. Profiles of heating rates are computed from airborne LEANDRE 2 and space-borne CALIOP lidar observations using two mineral dust model constrained by airborne in situ data and ground-based sunphotometer obtained during the campaign. Complementary space-borne observations (from MODIS and in-situ observations such as dropsondes are also used to take into account a realistic infrared contribution of the water vapour. We investigate the variability of the heating rate on the vertical within a dust plume, as well as the contribution of longwave radiation to the heating rate and the radiative forcing of dust during the nighttime. The sensitivity of the so-derived heating rate is also analyzed for some key variables for which the associated uncertainties are quite large. During daytime, the warming associated with the presence of dust was found to be between 1.5 K day−1 and 4 K day−1, on average, depending on altitude and latitude. Strong warming (i.e. heating rates as high as 8 K day−1 was also observed locally in some limited part of the dust plumes. Obviously, during nighttime much smaller values of heating/cooling are retrieved (less than ±1 K day−1 but large enough to modify the low tropospheric equilibrium. Furthermore, cooling is observed as the result of the longwave forcing in the dust layer, while

  6. Oclusão do apêndice atrial esquerdo com o Amplatzer Cardiac Plug em pacientes com fibrilação atrial Left atrial appendage closure with the Amplatzer Cardiac Plug in patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Ênio Eduardo Guérios

    2012-06-01

    Full Text Available FUNDAMENTO: A oclusão percutânea do apêndice atrial esquerdo (OAAE surgiu como alternativa à anticoagulação oral (AO para prevenção do acidente vascular cerebral (AVC em pacientes com fibrilação atrial não-valvular (FANV. OBJETIVO: Relatar os resultados imediatos e o seguimento clínico de pacientes submetidos a OAAE com o Amplatzer Cardiac Plug (ACP em um único centro de referência. MÉTODOS: Oitenta e seis pacientes consecutivos com FANV, contra-indicação à AO e escore CHADS2= 2,6±1,2 foram submetidos a OAAE com implante de ACP. Realizou-se seguimento clínico e ecocardiográfico no mínimo 4 meses após o implante. RESULTADOS: Todos os implantes foram guiados apenas por angiografia. O sucesso do procedimento foi de 99% (1 insucesso por tamponamento cardíaco e consequente suspensão da OAAE. Houve 4 complicações maiores (o tamponamento já referido, 2 AVCs transitórios e uma embolização com retirada percutânea da prótese e duas menores (um derrame pericárdico sem tamponamento e uma pequena comunicação interatrial evidenciada no seguimento. Houve 1 óbito hospitalar após 6 dias, não relacionado à intervenção. Todos os outros pacientes receberam alta sem AO. Após seguimento de 25,9 pacientes-ano (69 pacientes não houve AVCs nem embolizações tardias de próteses. O AAE estava completamente ocluído em 97% dos casos. Seis pacientes apresentaram evidência de trombo sobre a prótese, que desapareceram após reinstituição de AO por 3 meses. CONCLUSÃO: OAAE se associa a um alto índice de sucesso, um índice aceitável de complicações e resultados promissores a médio prazo, podendo ser considerada uma alternativa válida à OA na prevenção do AVC em pacientes com FANV.BACKGROUND: Percutaneous left atrial appendage closure (LAAC has emerged as an alternative to oral anticoagulation (OA for prevention of thromboembolic stroke in patients with non-valvular atrial fibrillation (NVAF. OBJECTIVE: To describe the

  7. Comparison of the clinical features and outcomes in two age-groups of elderly patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Shao XH

    2014-08-01

    Full Text Available Xing-Hui Shao,1 Yan-Min Yang,1 Jun Zhu,1 Han Zhang,1 Yao Liu,1 Xin Gao,1 Li-Tian Yu,1 Li-Sheng Liu,1 Li Zhao,2 Peng-Fei Yu,3 Hua Zhang,4 Qing He,5 Xiao-Dan Gu6 1Emergency and Intensive Care Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 2Department of Emergency, Fu Xing Hospital, Capital Medical University, Beijing, 3Department of Cardiology, Pingdu People’s Hospital, Pingdu, 4Department of Emergency, Qingdao Municipal Hospital, Qingdao, 5Department of Emergency, West China Hospital, Sichuan University, Chengdu, 6Department of Emergency, Sixth People’s Hospital of Chengdu, Chengdu, People’s Republic of China Background: Atrial fibrillation (AF disproportionately affects older adults. However, direct comparison of clinical features, medical therapy, and outcomes in AF patients aged 65–74 and ≥75 years is rare. The objective of the present study was to evaluate the differences in clinical characteristics and prognosis in these two age-groups of geriatric patients with AF.Materials and methods: A total of 1,336 individuals aged ≥65 years from a Chinese AF registry were assessed in the present study: 570 were in the 65- to 74-year group, and 766 were in the ≥75-year group. Multivariable Cox hazards regression was performed to analyze the major adverse cardiac events (MACEs between groups.Results: In our population, the older group were more likely to have coronary artery disease, hypertension, previous stroke, cognitive disorder, or chronic obstructive pulmonary disease, and the 65- to 74-year group were more likely to have valvular heart disease, left ventricular systolic dysfunction, or sleep apnea. The older patients had 1.2-fold higher mean CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes, stroke scores, but less ­probability of being prescribed drugs. Compared with those aged 65–74 years, the older group had a higher risk of death (hazard ratio 2

  8. Intercomparison of MODIS-Aqua C051 and C006 Level 3 Deep Blue AOD and Ångström exponent retrievals over the Sahara desert and the Arabian Peninsula during the period 2002-2014

    Science.gov (United States)

    Gkikas, Antonis; Basart, Sara; Korras-Carraca, Marios; Papadimas, Christos; Hatzianastassiou, Nikos; Sayer, Andrew; Hsu, Christina; Baldasano, Jose Maria

    2015-04-01

    Dust loads emitted from the arid regions of Northern Africa and the Arabian Peninsula account for the major portion of the global dust aerosol burden. Depending on prevailing atmospheric circulation they can be transported far away from their source areas. Considering the key role of dust aerosols to weather and climate a better description of their spatial and temporal variability it is an issue of great importance. The main target of the present study is to describe aerosols' regime over Northern Africa and Arabian Peninsula using Deep Blue aerosol optical depth (AOD550nm) and Ångström exponent (α412-470nm) measurements. Given the applied changes to the retrieval algorithm, emphasis is also given to the inter-comparison between the data from Collections 051 and 006. The analysis is performed using MODIS-Aqua daily Level 3 data at 1°x1° spatial resolution over the period 2002-2014. The study region extends from 20°W to 60°E and from 0° to 40°N. The obtained long-term geographical distributions reveal many similarities between C051 and C006 AOD retrievals. They both indicate a zone of high AODs along the parallel of 15°N, extending from the western coasts of Africa to Chad where the maximum values (~1.3) are recorded. In the Arabian Peninsula, the maximum AODs (up to 0.6) are found in Iraq. On the contrary, more apparent differences between the two collections are found for α412-470nm. It is evident a reduction of C006 retrievals, which is more pronounced across the Sahara desert. In C006, the α412-470nm values over the deserts of Northern Africa and Middle East mostly vary from 0 to 0.6 while higher values (up to 1.5) are observed in sub-sahel regions, west coasts of Saudi Arabia and Iran. During the study period, in both collections, AOD has decreased by up to 93% in N. Africa (northern parts of Algeria) while it has increased by up to 70% in the Middle East (northern parts of Iraq). Reversed tendencies are found for the α412-470nm retrievals. For

  9. Isotope hydrology of the shallow groundwaters of the western desert

    International Nuclear Information System (INIS)

    The Nubian aquifer of Egypt and the northern Sudan is part of one of the largest sandstone aquifer systems in the world. The origin and direction of flow of its waters has been disputed for more than half a century. Early models suggested that vast amounts of water in this system fell as rain and infiltrated thousands of years ago under a much more pluvial climatic regime, and that they have remained essentially stagnant and unrecharged ever since. Another early model maintains that the system is actually being recharged in the tropical and sub-Sahelian regions of Chad and the Sudan, and that water slowly flows northeastward toward the Egyptian oases and the lower Nile. In the 1920s, Ball proposed that the piezometric surface of the aquifer followed the regional slope of the land surface, and that the minor oases or 'birs' in the desert, as well as the major oases such as Kharga and Dahkla, occur in topographic depressions where the surfaces intersect. Radiocarbon analyses of deep waters in the major oases have shown that they have been in the subsurface for times of the order of 10 000 to 20 000 years. Although most of this area lies between the zero-isohyets, some more recent models propose that there is currently enough recharge during occasional rains in the desert to maintain the hydraulic gradient observed. During the field seasons of 1979 and 1982, our study involved sampling 17 sources of shallow groundwater for isotopic analyses, in an attempt to determine their origin. Deuterium and oxygen-18 results for these sites showed that most of the waters have not been subject to an appreciable heavy-isotope enrichment by evaporation from compositions expected in local meteoric waters. After modelling corrections for isotopic dilution by the dissolution of mineral carbonates, the majority of samples were shown to have radiocarbon contents which can be reconciled only with the presence of 14C from nuclear weapons tests. One of the sites where anthropogenic

  10. Fossil Chironomidae (Insecta: Diptera) as quantitative indicators of past salinity in African lakes

    Science.gov (United States)

    Eggermont, Hilde; Heiri, Oliver; Verschuren, Dirk

    2006-08-01

    set with 8 fresh (15-168 μS/cm) lakes in Cameroon, West Africa, and one hypersaline desert lake in Chad. This experiment yielded poorer error statistics, primarily because the need to amalgamate East and West African sister taxa reduced overall taxonomic resolution and increased the mean tolerance range of retained taxa. However, the merged data set constrained better the salinity optimum of several freshwater taxa, and further increased the probability of finding good modern analogues. We then used chironomid stratigraphic data and independent proxy reconstructions from two fluctuating lakes in Kenya to compare the performance of new and previous African salinity-inference models. This analysis revealed significant differences between the various numerical techniques in reconstructed salinity trends through time, due to their different sensitivity to the presence or relative abundance of certain key taxa, combined with the above-mentioned threshold faunal response to salinity change. Simple WA and WMAT produced ecologically sensible reconstructions because their step-like change in inferred conductivity near 3000 μS/cm mirrors the relatively rapid transitions between fresh and saline lake phases associated with climate-driven lake-level change in shallow tropical closed-basin lakes. Statistical camouflaging of this threshold faunal response in WA-PLS and ML models resulted in less trustworthy reconstructions of past salinity in lakes crossing the freshwater-saline boundary. We conclude that selection of a particular inference model should not only be based on statistical performance measures, but consider chironomid community ecology in the study region, and the amplitude of reconstructed environmental change relative to the modern environmental gradient represented in the calibration data set.

  11. Health and sanitary status in 1970 of Tubu nomads dwelling in Northeastern Niger

    Institute of Scientific and Technical Information of China (English)

    Jean-Franois Magnaval; Christian Oosterbosch; Michel Mandl; MABN group

    2014-01-01

    Background: The Tubu are nomadic people who live in remote parts of the central Sahara, primarily in the Tibesti massif (Chad), and in both Northeastern Niger and Southern Libya. All of these areas are close to become conflict zones. However, no data about the Tubu’s health and sanitary status are currently available, which would be of major concern if humanitarian interventions would become required. Methods: In 1970, the “Mission Anthropologique Belge au Niger” (MABN) investigated a Tubu tribe named Broaya that lived at Seguedine and Djado on the northeastern rim of the Tenere desert. One hundred fifty-one adult volunteers answered an oral questionnaire and underwent a medical examination, followed by the collection of blood thin films and samples of urine and stool. The environmental fauna of medical importance was also studied. Results: Albeit 43 year-old, these results have not been previously published. The estimated age of death for fathers was approximately 56 years, and that for mothers was 60 years. On average, each married woman had had 4.7 children. The overall perinatal mortality rate was 232 ‰, the overall infant mortality rate was 153 ‰, and the overall child mortality rate was 99 ‰. The mean height was 164.1 cm and 157.4 cm, the mean weight was 50.1 kg and 47.9kg, and the mean blood pressure was 131/78 mmHg and 127/75 mmHg for males and females, respectively. The physical examination found 6 cases of blindness (4.0%). Five subjects presented with an elevated blood pressure (3.3%), and 5 (3.3%) displayed an abnormal thoracic auscultation evocative of tuberculosis or of an acute lung infection. The abdominal examination and renal palpation found 5 large masses (3.3%), and 2 subjects had a palpable enlarged spleen (1.3%). The blood thin films were fixed in methanol and subsequently examined in Toulouse. The search for blood parasites was negative. The urine samples were centrifuged and then microscopically examined in the field. No blood

  12. INIS Progress and Activity Report 2011

    International Nuclear Information System (INIS)

    Annual Highlights 2011: The International Nuclear Information System (INIS) was established by the IAEA, in collaboration with interested Member States and international organizations, in 1969. The main objective of INIS was to provide access to information on scientific literature on the peaceful uses of nuclear energy published worldwide. INIS operates under special membership arrangements that set specific duties and privileges. Chad, Mauritania, and Gabon joined INIS in 2011, bringing the total number of INIS members to 151 (127 countries and 24 international organizations). In 2011, 109 914 bibliographic records were added to the INIS Collection, making a total of 3 367 451 records available to the public. An additional 13 586 full-text documents were prepared and uploaded, bringing the total of full-text documents available in the Collection to 439 314, of which 309 627 are available to the public. This collection of documents on the peaceful uses of nuclear science and technology is now fully indexed and searchable online using Google-based technology. Over 50 000 searches and 4000 downloads were performed monthly. The 13th INIS/ETDE Joint Technical Committee Meeting (JTCM) was held from 20 to 21 October 2011 in Vienna, Austria and 12 countries participated. 27 Actions and Recommendations were adopted as guidelines for cooperation and direction for the next two years. The joint INIS/ETDE Thesaurus, Revision 2.4, was issued in April and contains 21 881 valid descriptors and 8675 forbidden terms. INIS production and release processes were redesigned to be based on XML format, removing one barrier for Unicode compliance. IT infrastructure used to support INIS business was consolidated and upgraded. Training, assistance and feedback was provided to a number of INIS centres, improving all aspects of their INIS operation capabilities. In 2011, INIS also organized a well-attended regional (AFRA) training course in Morocco, and a training seminar in Vienna. Overall

  13. Forecast-based Integrated Flood Detection System for Emergency Response and Disaster Risk Reduction (Flood-FINDER)

    Science.gov (United States)

    Arcorace, Mauro; Silvestro, Francesco; Rudari, Roberto; Boni, Giorgio; Dell'Oro, Luca; Bjorgo, Einar

    2016-04-01

    image processing. Flood-FINDER aims to pre-empt this process and to provide preliminary analyses where no field data is available. In the early 2015, the Flood-FINDER's forecast along the Shire River has been used to guide the rapid mapping activities in Southern Malawi and Northern Mozambique. It proved efficient support providing timely information about the evolution of the flood event over an area lacking of field data. Regarding in-country capacity building, Flood-FINDER allowed UNOSAT to set up in middle 2015 a flood early warning system in Chad along the Chari River basin with the collaboration of Chadian Ministry of hydraulics and livestock. Weekly flood bulletins have been shared with local authorities and UN agencies over the entire rainy season. Finally, an experimental version of the global web alerting platform has been recently developed for supporting the El Nino flood preparedness in the Horn of Africa. Flood-FINDEŔs mission is to support decision makers throughout all the disaster management cycle with flood alerts, modelled scenarios, EO-based impact assessments and with direct support at country level to implement disaster mitigation strategies. The aim for the future is to seek funding for having the global system fully operational using CERN's supercomputing facilities and to establish new in-country projects with local authorities.

  14. Covering Post-Conflict Elections: Challenges for the Media in Central Africa Wahlberichterstattung in Post-Konflikt-Phasen: Herausforderungen für die Medien in Zentralafrika

    Directory of Open Access Journals (Sweden)

    Marie-Soleil Frère

    2011-01-01

    Full Text Available In the past ten years, elections were held in six countries of Central Africa experiencing “post-conflict” situations. The polls that took place in Burundi (2005, the Central African Republic (2005, the Democratic Republic of the Congo (2006, Congo-Brazzaville (2002, 2007, Chad (1996, 2001, 2006 and Rwanda (2003 were crucial for peace-building. In some cases, they were widely supported and supervised by the international community, being considered the last step of a peace process and the first step toward establishing a truly representative “post-conflict” regime. The media were expected to play a large part in supporting these elections, both to inform the citizens, so they could make an educated choice, and to supervise the way the electoral administration was organizing the polls. This paper attempts to show the many challenges faced by the media while covering these post-conflict electoral processes. In a context of great political tension, in which candidates are often former belligerents who have just put down their guns to go to the polls, the media operate in an unsafe and economically damaged environment, suffering from a lack of infrastructure, inadequate equipment and untrained staff. Given those constraints, one might wonder if the media should be considered actual democratic tools in Central Africa or just gimmicks in a “peace-building kit” (including “free and fair” elections, multipartism and freedom of the press with no real impact on the democratic commitment of the elite or the political participation of the population.In den letzten zehn Jahren wurden in sechs zentralafrikanischen Ländern, die sich in einer Post-Konflikt-Phase befanden, Wahlen abgehalten. Die Wahlgänge in Burundi (2005, der Zentralafrikanischen Republik (2005, der Demokratischen Republik Kongo (2006, Kongo-Brazzaville (2002, 2007, dem Tschad (1996, 2001, 2006 und Ruanda (2003 waren entscheidend für die Friedenskonsolidierung. Einige dieser

  15. La constitution algérienne de 1989: une passerelle entre le socialisme et l'islamisme

    Directory of Open Access Journals (Sweden)

    D. Beke

    1991-01-01

    Full Text Available The riots of October 1988, the most violent uprising since independence against FLN-rule, forced president Chadli Bendjedid to accelerate and to extend the constitutional reforms announced earlier. An adaption of the constitutional law to the ongoing economic liberalization-process had become a necessity, but the popular pressure now not only asked economic changes, but also profound political reform.The new constitutional text was rapidly elaborated by a small circle of persons around the President and then submitted directly to a popular referendum. In contradiction with the procedure fixed by the previous constitution, the National Assembly was not involved nor even consulted. The constitution of 1989 generates an entirely new political regime. The word "socialism", basis of the official doctrine since independence and largely confirmed by the provisions of the constitution of 1976, is banned completely. The new constitution also provides for the political responsibility of the Head of the Government and the members of the Government to the National People's Assembly, and not any more to the Presidentonly. In the chapter on fundamental freedoms and the rights of man, it is explicitly provided that the State guarantees the right to form political associations. This new timorous formulation entails the end of the one-party system and the FLN's exclusive hold on power.Some basic principles remain: Algeria is still considered a popular democratic state. Islam is the state religion and the official language is Arabic. No reference is made to the Berber language or culture. New is that the exercise of the guaranteed fundamental freedoms and rights can not be submitted any more to the imperatives of a socialist revolution. It is also stated that judges only obey to the law, they are not submitted any more to the revolutionary legality. A Constitutional Council is created to ensure that the constitution is respected but citizens have no right to

  16. Rewriting the Landform History of One of Africa's Three Largest Basins

    Science.gov (United States)

    Wilkinson, Justin

    2014-01-01

    The Kalahari Basin in southern Africa - one of the largest basins in Africa, along with the Congo and Chad basins - has attracted attention since David Livingstone traveled through the area in the 1840s. It is a semiarid desert with a large freshwater swampland known as the Okavango Swamp (150 km radius). This prominent megafan (a fan with radii >100 km), with its fingers of dark green forests projecting into the dun colors of the dunes of the Kalahari semi-desert, has been well photographed by astronauts over the years. The study area in the northern Kalahari basin is centered on the Okavango megafan of northwest Botswana, whose swampland has become well known as an African wildlife preserve of importance to biology and tourism alike. The Okavango River is unusual because it has deposited not one but two megafans along its course: the Okavango megafan and the Cubango megafan. The Okavango megafan is one of only three well-known megafans in Africa. Megafans on Earth were once thought to be rare, but recent research has documented 68 in Africa alone. Eleven megafans, plus three more candidates, have been documented in the area immediately surrounding the Okavango feature. These 11 megafans occupy the flattest and smoothest terrains adjacent to the neighboring upland and stand out as the darkest areas in the roughness map of the area. Megafan terrains occupy at least 200,000 sq km of the study area. The roughness map shown is based on an algorithm used first on Mars to quantify topographic roughness. Research of Earth's flattest terrains is just beginning with the aid of such maps, and it appears that these terrains are analogous to the flattest regions of Mars. Implications: 1. The variability in depositional style in each subbasin may apply Africa-wide: rift megafan length is dominated by rift width, whereas Owambo subbasin megafans are probably controlled by upland basin size; Zambezi subbasin megafans appear more like foreland basin types, with the position of

  17. Characterization of the seasonal transatlantic mineral dust route to improve the understanding of the possible impact on climate

    Science.gov (United States)

    Ben Ami, Yuval

    Mineral dust aerosol is the second aerosol constituent (by mass), after marine sea-salt aerosol, in the Earth's atmosphere. Suspended dust participates in a range of processes, related to the energy, hydrological and nutrients cycles. Although it is important, there are still many basic open questions in this field related to the processes of emission, transport, and deposition. Focusing on the largest source of mineral dust, North Africa, and on the main transport route over the tropical and sub-tropical North Atlantic Ocean, this study aims to investigate the properties of dust plumes and how they change in space and time. In this work we reveal a new annual partition for characterization of the oceanic dust, composed of two heavy loading periods, called hereafter, the northern-route and southern-route period, and one clean, light-loading period, characterized by unusually low average optical depth of dust. The newly proposed dusty seasons differ in their statistical characteristics: the southern route period lasts from the end of November until the end of March. It is characterized by a steady southern position, low frequency of dust events, low background values and high variance in dust loading. The northern-route period lasts from the end of March to mid October, and is associated with a steady drift of the route northward, reaching a location which is ˜1,500 km north of the southern route. During the northern-route period, there is a higher frequency of dust events, higher background and smaller variance in dust loading. The annual periodicity in Atlantic dust transport is tightly linked to the spatial distribution and patterns of activity of North African dust sources. Our results emphasize the dominance of one key dust source, the Bodele depression in Chad, which has the potential to modulate the Atlantic dust loading. In addition we show that the dust plumes average height, over the ocean, is characterized by a bi-modal distribution, which is more

  18. A geoethical approach in higher education: the project RUSSADE in cooperation with Sahelian Universities

    Science.gov (United States)

    Semita, Carlo; Ferrero, Elena; Calvo, Angela; Trucchi, Gabriella

    2014-05-01

    Sahel has been plagued by a continuous process of environment degradation since the droughts of the 70s and 80s. The desertification process has a significant impact also on the natural and artificial water bodies, on the rivers flow and the river ecosystems, damaging human activities. Environmental damage exacerbates inequality by exerting a negative impact on the population, in the meantime, the inequalities of human development amplify also environmental damage. The project "RUSSADE" (Réseau des Universités Sahéliennes pour la Sécurité Alimentaire et la Durabilité Environnement), included in the EuropeAid-ACP-EU Cooperation Programme in higher education (EDULINK II), has the specific objective to enhance higher education systems through the implementation of an interdisciplinary Master. The courses are designed with a geoethical approach in order to integrate Earth and Life Sciences to give the Sahelian students technical, scientific and methodological bases and to develop the skills of managing natural resources and to improve agriculture and food security. The systemic and multidisciplinary approach will involve several fields of knowledge. The programs of the different areas are linked to each other and Italian and Sahelian teachers cooperate together both in the courses planning and in the teaching activities. The partners, three African Higher Education Institutions (HEIs) of Niger (CRESA - Abdou Moumouni University), Burkina Faso (LERNSE - Polytechnic University of Bobo-Dioulasso) and Chad (University Institute of Sciences and Techniques of Abeché), will develop an education project with the main objective to use scientific knowledge to fight hunger and poverty and to promote environmental protection in a sustainable development perspective. The quality of higher education in the management of natural resources in agriculture will improve living conditions of Sahelian people. The Master, planned with innovative connections, includes a field training

  19. International assistance to intervention policies and implementation of area-wide tsetse and animal trypanosomiasis programmes

    International Nuclear Information System (INIS)

    agricultural development. The Programme Against African Trypanosomiasis (PAAT) and the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) of the African Union jointly developed a set of criteria and guiding principles to assist tsetse-affected countries in the selection of priority areas for intervention against the AAT problem. The concept of area-wide integrated pest management (AW-IPM) has been designed to address geographically and ecologically well demarcated tsetse fly populations impacting seriously on SARD and to ensure efficiency of the intervention and sustainability of results. AW-IPM exploits favourable trends (entomological, agro-ecological, climatic, anthropogenic and epidemiological), which may assist in redressing the impact of the disease. Thus, substantial benefits from interventions are believed to result, particularly for the development of mixed-crop-livestock systems in the 'cotton-belt', a transfrontier area of Burkina Faso and Mali, and in the southern part of the Rift Valley in Ethiopia. With regards to HAT, priority countries for intervention, as far as WHO is concerned, include Angola, Chad, Congo, Cote d'Ivoire, Democratic Republic of Congo, Guinea and Sudan. For HAT the next challenge is the development of tools, supporting the strategies for the elimination of the disease. Sets of measures against the HAT and the AAT problem, as part of overall efforts directed at improved public health and SARD, respectively, will necessitate an integration of technical, institutional, socio-economic, public health and agricultural development considerations. This integrated approach will, in turn, provide the supportive environment for emergency interventions in HAT foci, balanced investments in AAT programmes, amalgamated with the AW-IPM concept, as preliminary essential steps for technical success, anticipated SARD impact and sustainability. In the context of the described overall agricultural development and public health framework the

  20. Light adaptability of tow strains of Spirulina (Arthrospra) platensis%两族群钝顶螺旋藻Spirulina (Arthrospra) platensis光强适应性

    Institute of Scientific and Technical Information of China (English)

    高凌岩; 高锦; 王林和

    2011-01-01

    螺旋藻光强适应性与其族群、培养时间等条件相关。为了探明分布在鄂尔多斯高原沙区碱湖的钝顶螺旋藻Spirulina(Arthrospra)platensis的光强适应性,采用比色法、生物量法实地、长期观测了其光强适应性,并与乍得湖引进的钝顶螺旋藻进行了比较。结果表明:24℃、连续7天荧光灯的照射下,国内族群的光补偿点约为0.58μmol·m^-2·s^-1;光饱和点约为82.1μmol·m^-2·s^-1;光抑制点约为129.6μmol·m^-2·s^-1;光分解点为230μmol·m^-2·s^-1。129.6μmol·m^-2·s^-1的连续光能够使两族群的很多藻丝体完全压紧。超过230μmol·m^-2·s^-1使国内族群以多个藻丝体纠结成团的方式避免高光强;而引进族群的藻丝体则不能。无论是液相或是固相螺旋藻都能够被光分解。两族群的藻丝体都需要暗的修复期。藻丝体有趋光性。%Light adaptability of Spirulina has relationship with its strains,cultural time and etc..The Spirulina that came from Erdos Plateau sand area's alkaline lakes was tested by the methods of color comparison,production,observation at the lake and lab for long time to study it's light adaptability,and the Spirulina came from Chad lake was use to compare with the strain.The results indicated that the native strain of Spirulina 's compensation point of light is 0.58μmol·m^-2s^-1,sturation of light is 82.1 μmol·m^-2s^-1,stress point of light is 129.6μmol·m-2s-1,decomposing point of light is 230μmol·m^-2s^-1 for the single alga.The native strain can make a ball in several algae to escape from strong light.But the intruduced strain can't do in this way and it can be decomposed on 230μmol·m^-2s^-1 continuous light when OD560 is 0.06.The continuous 129.6μmol·m^-2s^-1 light make many algae no helix space for both strains.Spirulina can be decomposed by light wathever in liquid or on soild.The both strains are much more healthy under the rhythm with light and dark than the

  1. Geochronological, geochemical and mineralogical constraints of emplacement depth of TTG suite from the Sinassi Batholith in the Central African Fold Belt (CAFB) of northern Cameroon: Implications for tectonomagmatic evolution

    Science.gov (United States)

    Houketchang Bouyo, M.; Penaye, J.; Njel, U. O.; Moussango, A. P. I.; Sep, J. P. N.; Nyama, B. A.; Wassouo, W. J.; Abaté, J. M. E.; Yaya, F.; Mahamat, A.; Ye, Hao; Wu, Fei

    2016-04-01

    at the northern margin of CAFB of northern Cameroon: (1) inherited magmatic sources ranging from one group to another at ca 692, 713, 722, 746 and 772 Ma; (2) successive emplacement ages at ca 670-686 Ma (orthogneisses group), ca 661-666 Ma (synchronous emplacement of the Djourdé and Sinassi groups) and ca 644 Ma (emplacement age of eyespots quartz diorite in the Sinassi group); and (3) post-magmatic alteration or metamorphism at ca 600 Ma. Correlations with the neighboring Mayo Kebbi Batholith in southwestern Chad show geochemical and geochronological similarities, demonstrating that the Sinassi and Mayo Kebbi granitoids beyond political boundaries are parts of a unique Sinassi-Mayo Kebbi Batholith witnessing a Neoproterozoic subduction-related continental magmatic arc setting of Andean-type.

  2. Multi-satellite sensor study on precipitation-induced emission pulses of NOx from soils in semi-arid ecosystems

    Science.gov (United States)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Veres, Patrick; Williams, Jonathan; Wagner, Thomas

    2016-04-01

    to develop several days before the actual first rainfall. After the initial large pulse, soil emissions diminish rapidly the subsequent day, but stay still enhanced over the following two weeks with 1.6 ng N m‑2s‑1 averaged over the Sahel region. We also present a case study in the surroundings of Lake Chad which is based on daily orbits of OMI and does not rely on averaging over multiple time series. A characteristic enhancement in NO2 VCDs, in response to the first rain of the wet season, is found which agrees well with our general findings for the Sahel region.

  3. Quantum Field Theory in Curved Spacetime

    Science.gov (United States)

    Reynolds, Sally C.; Gallagher, Andrew

    2012-03-01

    List of contributors; Foreword J. T. Francis Thackeray; 1. African genesis: an evolving paradigm Sally C. Reynolds; 2. Academic genealogy Peter Ungar and Phillip V. Tobias; Part I. In Search of Origins: Evolutionary Theory, New Species, and Paths into the Past: 3. Speciation in hominin evolution Colin Groves; 4. Searching for a new paradigm for hominid origins in Chad (Central Africa) Michel Brunet; 5. From hominoid arboreality to hominid bipedalism Brigitte Senut; 6. Orrorin and the African ape/hominid dichotomy Martin Pickford; 7. A brief history and results of 40 years of Sterkfontein excavations Ronald J. Clarke; Part II. Hominin Morphology Through Time: Brains, Bodies and Teeth: 8. Hominin brain evolution, 1925-2011: an emerging overview Dean Falk; 9. The issue of brain reorganisation in Australopithecus and early hominids: Dart had it right Ralph L. Holloway; 10. The mass of the human brain: is it a spandrel? Paul R. Manger, Jason Hemingway, Muhammad Spocter and Andrew Gallagher; 11. Origin and diversity of early hominin bipedalism Henry M. McHenry; 12. Forelimb adaptations in Australopithecus afarensis Michelle S. M. Drapeau; 13. Hominin proximal femur morphology from the Tugen Hills to Flores Brian G. Richmond and William L. Jungers; 14. Daily rates of dentine formation and root extension rates in Paranthropus boisei, KNM-ER 1817, from Koobi Fora, Kenya M. Christopher Dean; 15. On the evolutionary development of early hominid molar teeth and the Gondolin Paranthropus molar Kevin L. Kuykendall; 16. Digital South African fossils: morphological studies using reference-based reconstruction and electronic preparation Gerhard W. Weber, Philipp Gunz, Simon Neubauer, Philipp Mitteroecker and Fred L. Bookstein; Part III. Modern Human Origins: Patterns, and Processes: 17. Body size in African Middle Pleistocene Homo Steven E. Churchill, Lee R. Berger, Adam Hartstone-Rose and Headman Zondo; 18. The African origin of recent humanity Milford H. Wolpoff and Sang-Hee Lee

  4. African easterly wave energetics on intraseasonal timescales

    Science.gov (United States)

    Alaka, Ghassan J., Jr.

    African easterly waves (AEWs) are synoptic-scale eddies that dominate North African weather in boreal summer. AEWs propagate westward with a maximum amplitude near 700 hPa and a period of 2.5-6-days. AEWs and associated perturbation kinetic energy (PKE) exhibit significant intraseasonal variability in tropical North Africa during boreal summer, which directly impacts local agriculture and tropical cyclogenesis. This study performs a comprehensive analysis of the 30-90-day variability of AEWs and associated energetics using both reanalysis data and model output. Specifically, the PKE and perturbation available potential energy (PAPE) budgets are used to understand the factors that contribute to PKE maxima in West Africa and the extent to which these surges of AEW activity are modulated by the Madden-Julian oscillation (MJO). The role of the MJO in the intraseasonal variability of AEWs is assessed by comparing PKE sources as a function of an MJO index and a local 30-90-day West African PKE index. Since East Africa is an initiation zone for AEW activity and is modulated by the MJO, the relationship between this region and West Africa is a primary focus in this study. The intraseasonal variability of AEW energetics is first investigated in reanalysis products. While reanalysis data depicts a similar evolution of 30-90-day PKE anomalies in both the MJO and a local PKE index, the MJO index describes only a small (yet still significant) fraction of the local 30-90-day variance. In boreal summers with more significant MJO days, the correlation between the two indices is higher. Baroclinic energy conversions are important for the initiation of 30-90-day West African PKE events east of Lake Chad. In West Africa, both barotropic and baroclinic energy conversions maintain positive PKE anomalies before they propagate into the Atlantic. The primary role of diabatic heating is to destroy PAPE in a negative feedback to baroclinic energy conversions in West Africa. More frequent

  5. Technical Cooperation Report for 2007. Report by the Director General

    International Nuclear Information System (INIS)

    achievements in technical cooperation in each of the regions in 2007, describing regional emphases and responses to national priorities. As the Millennium Development Goals remain a key area of focus, the report demonstrates how the IAEA is making a contribution to global efforts to fight poverty, hunger and disease, as well as to support environmental sustainability and the health of mothers and children. Health in Asia was addressed in 2007, for example, through regional projects to train new medical staff, while in Europe, radiotherapy services were being upgraded in the Balkans. In Africa, projects on better animal health and improved crop productivity contributed to the fight against hunger, and in Latin America, activities in food fortification and the determination of vitamin deficiency helped to improve the health of mothers and children. Ensuring sustainable socioeconomic development in the future will depend on a reliable energy supply. Among the energy-related technical cooperation projects in Africa in 2007, support to energy planning helped to train national energy planning teams in Burkina Faso, Chad, Cote d'Ivoire, Mauritania and Niger. Assistance was also being provided to several African countries to help with the different stages of planning a nuclear power programme. In Asia and the Pacific, RCA Member States received support in the application of Agency-developed analytical tools for energy planning. In Latin America, energy security is seen as a priority issue. In 2007, the Agency provided assistance to the conversion of Europe's older research reactors from high to low enriched uranium. In Asia and the Pacific, the Agency provided advice on the development of nuclear power, based on the latest Agency guidelines and the document 'Milestones in the Development of a National Infrastructure for Nuclear Power'. (author)

  6. Ancient glaciations and hydrocarbon accumulations in North Africa and the Middle East

    Science.gov (United States)

    Le Heron, Daniel Paul; Craig, Jonathan; Etienne, James L.

    2009-04-01

    at the ice front. Production of linear accumulations of sediment, parallel to the ice front, also occurred between tunnel valleys at the grounding line. In Arabia, the geometry of these features may have been influenced by local tectonic uplift. As glaciogenic reservoirs, Hirnantian deposits are already of great economic significance across central North Africa. Therefore, an appreciation of the processes of ice sheet growth and decay provides significant insights into the controls on large-scale heterogeneities within these sediments, and in analogue deposits produced by glaciations of different ages. Deglacial, Early Silurian black shale represents the most important Palaeozoic source rock across the region. Existing models do not adequately explain the temporal and spatial development of anoxia, and hence of black shale/deglacial source rocks. The origins of a palaeotopography previously invoked as the primary driver for this anoxia is allied to a complex configuration of palaeo-ice stream pathways, "underfilled" tunnel valley incisions, glaciotectonic deformation structures and re-activation of older crustal structures during rebound. A putative link with the development of Silurian glaciation in northern Chad is suggested. Silurian glaciation appears to have been restricted to the southern Al Kufrah Basin in the eastern part of North Africa, and was associated with the deposition of boulder beds. Equivalent deposits are lacking in shallow marine deposits in neighbouring outcrop belts. Evidence for Carboniferous-Permian glaciation is tentative in the eastern Sahara (SW Egypt) but well established on the Arabian Peninsula in Oman and more recently in Saudi Arabia. Pennsylvanian-Sakmarian times saw repeated glaciation-deglaciation cycles affecting the region, over a timeframe of about 20 Myr. Repeated phases of deglaciation produced a complex stratigraphy consisting, in part, of structureless sandstone intervals up to 50 m thick. Some of these sandstone intervals

  7. Satellite Remote Sensing Signatures of Impact Structures

    Science.gov (United States)

    Garvin, J. B.; Grieve, R. A. F.; Schnetzler, C. C.

    1995-09-01

    interior basin with inner rim wall terraces [3,4]. There are suggestions that geobotanical anomalies revealed by the multispectral data may be associated with surficial ejecta deposits. It is our opinion that quantitative remote sensing of the most recent complex cratering events in Earth history will help define "pathfinder algorithms" which could then be used as search criteria for as yet undiscovered impact landforms in such regions as Africa, South America, and even parts of Siberia. For instance, the recently proven Aorounga multiringed impact feature (13 km diameter, located in Chad, with a potential Cenozoic age [2]) was observed in TM data by several investigators (including us) and considered as a possible impact feature in spite of its close proximity to a major volcanic province (Tibesti) and its appearance similar to an eroded ring dyke. Table I highlights the datasets available, with future opportunities for exhaustive remote sensing analyses of additional features possible from RADARSAT SAR, EOS (MODIS, Aster, etc.), Landsat 7, and SPOT 4,5. The most significant lesson learned from our investigation is that terrestrial impact craters require more precise and comprehensive remote sensing analyses than those of nearby planets due to the efficacy of erosion on Earth, which serves to rapidly obscure or degrade "thin-skinned" landforms such as impact features. It is our observation that the combination of orbital SAR with multispectral imaging best defines impact-related deposits and structures. Furthermore, topographic data generated by means of orbital SAR interferometry (SRL, ERS-1, and Radarsat) and perhaps from orbital laser altimetry (e.g., Shuttle Laser Altimeter on STS-72 in 1995) will be of great value when attempting to reconstruct pre-erosional crater dimensions [3]. {We acknowledge the NASA Goddard Director's Discretionary Fund for initial support of this work, and Drs. G. Soffen and Klineberg}. References: [1] Grieve R. A. F. (1991) Meteoritics, 26

  8. Space Shuttle Radar Images of Terrestrial Impact Structures: SIR-C/X-SAR

    Science.gov (United States)

    McHone, J. F.; Blumberg, D. G.; Greeley, R.; Underwood, J. R., Jr.

    1995-09-01

    The Spaceborne Radar Laboratory (SRL) orbited Earth in April and October of 1994 operating two imaging radars: X-SAR, an X-band (3 cm lambda) instrument, and the polarimetric SIR-C, a combination L-band/C-band (24 cm and 5.6 cm lambda). More than 150 terrestrial meteorite craters and astroblemes are presently known. Three of these, Wolfe Creek in Australia; Roter Kamm in Namibia; and Zhamanshin in Kazakhstan, were planned targets and were imaged successfully with multiple passes and look directions. Several other impact sites were fortuitously imaged while radar data were being collected for other purposes. These sites include B.P. and Oasis structures in Libya, Aourounga multi-ring feature in Chad, Amguid crater in Algeria, and the Spider astrobleme and Henbury crater field in Australia. Wolfe Creek (19 degrees 10'S; 127 degrees 47'E; 875 m dia) Both the elevated rim and the inner floor of this crater appear as radar bright features. Strong radar returns are due to blocky rubble textures in the rim and desert vegetation within the central bowl. Associated linear sand dunes show differential penetration properties in the various radar wavelengths and polarization. Roter Kamm (27 degrees 46'S; 016 degrees 18'E; 2.5 km dia) This bowl-shaped crater is mostly buried by wind-blown sands. Comparison of differential radar penetration patterns due to changes in wavelength and look direction reveal concealed target rocks and a buried possible ejecta unit. Zhamanshin (48 degrees 24'N; 060 degrees 48'E; 14 km dia) This unusual impact structure, first detected by the presence of glassy impact melt products [1], has very little topographic relief and is nearly invisible on survey-quality radar imagery. Fully processed images, however, enhance subtle vegetation patterns which highlight regional streams. These drainage patterns are now being analyzed in detail to better delineate boundaries and internal structure of this feature. B.P. Structure (25 degrees 19'N; 024 degrees 20'E

  9. 剖宫产瘢痕部位妊娠不同治疗方式及其疗效分析%Cesarean scar pregnancy different treatment and curative effect analysis

    Institute of Scientific and Technical Information of China (English)

    习红丽; 洪莉

    2015-01-01

    Objective The aim of this study is to investigate the clinical treatment and therapeutic effect of cesarean scar pregnancy. Methods Between December 2008 to March 2015,the records of 90 cases of gynecologic clinical diagnosis of cesarean scar pregnancy patients were included into this study. The curative effect of different treatments and the influence on ovarian function were retrospectively analyzed. All these patients were be randomly assigned according to the different treatment,24 patients with group A undergoing line medicine conservative treat-ment(mifepristone combined methotrexate),group B 28 patients undergoing laparoscopic resection of the lesions of pregnancy + uterine defect re-pair;C group of 38 cases of patients with uterine artery embolization. The clinical therapeutic effect and safety of three groups of patients were com-pared. Results ①The three groups of patients with blood βHCG levels were significantly reduced compared with before treatment( P ﹤ 0. 05), the comparison between groups(group A ﹥ group B ﹥ group C)had statistically significant( P ﹤ 0. 05). ②The hormone levels between groups was no significant difference( P ﹥ 0. 05). ③The recovery time in the menstrual cycle and blood β HCG normal time - consuming,vaginal bleed-ing time,bleeding volume,length of hospital stay on indicators,time consuming group C ﹤ group B ﹤ group A,statistically F test,there were significant difference( P ﹤ 0. 05). Conclusion Three kinds of treatment are to preserve the uterus and ovarian function,conform to the require-ments of the have fertility patients,uterine artery embolization in patients with short cure time,little trauma,quick recovery. Therefore,this treat-ment was recommended the uterine artery embolization to treatment uterine scar pregnancy.%目的:研究剖宫产瘢痕部位妊娠的临床治疗方式及疗效。方法选取2008年12月至2015年3月妇科收治的90例临床确诊剖宫产瘢痕部位妊娠患者作为研

  10. A field site for SIT control of Anopheles arabiensis in Northern State, Sudan: Analysis of historical data

    International Nuclear Information System (INIS)

    of Wadi Halfa) until 1950. This was attributed to passive transport by rail from Abu Hamed during a uniquely wet year. Records exist of its presence on trains on route across the desert. The railway, built in 1898, may have facilitated the invasion or re-invasion of this species into Northern State and Upper Egypt via Wadi Halfa, or at least allowed some gene flow between Wadi Halfa and Nile State populations. Since the late 1950s, apart from a few isolated records again attributed to passive transport, but by boat, An. arabiensis has not been found north of Ferka due to control activities, sparse human population and the unsuitable terrain. Most probably, the species was present in Northern State before the railway, since fever with malaria-like symptoms has been known in the Dongola area for more than a century before. In neighbouring Nile State, a post meroitic and medieval archaeological site at Gabati near Atbara, shows evidence of malaria. Similar studies are in progress within Northern State. An. arabiensis would be unlikely to survive a desert crossing before the advent of cars or aeroplanes, therefore within the last 4,000 years the primary route into Northern State would be along the Abu Hamed Reach and through the Fourth Cataract. The terrain here is inhospitable and sparsely populated. The river is only navigable for a short period of the year and then with difficulty. Archaeological records are limited, but this will soon be rectified. As part of the major route connecting Sudan to Egypt it has been well travelled and at times may have sustained military or farming settlements. The latter are possible because the rocky terrain forces the river into many smaller channels, when these dry up, the river beds rather than the rocky banks can be ideal for cultivation. Alternative routes into the area for the vector existed before 2,500 BC, in particular Wadi Howar, also known as the Yellow Nile, which once flowed from present day Chad to join the Nile just

  11. Cenozoic vegetation, climate changes and hominid evolution in tropical Africa

    Science.gov (United States)

    Bonnefille, Raymonde

    2010-07-01

    Ma in East Africa, 3 Ma earlier than in West Africa where it is documented at 7 Ma. At large geographical scale, this first increase in grass pollen simultaneously to forest increase in the marine records is interpreting as reflecting wetter conditions over the continent. Indeed, under global humid conditions, savanna could spread over the desert areas in the Northern and Eastern directions. A forest phase is well documented in West Africa between 7.5 and 7 Ma, but has not been shown in East Africa, mainly because of low resolution analysis of the DSDP East African record which needs further investigation for that period. A strong vegetation change took place between 6.3 and 6 Ma. It was marked by a trend of important decrease tree cover of the vegetation, simultaneous in West and East Africa. At that time, very arid conditions shown by scarce tree cover occurred over the whole tropical region. This happened before (or at) the early beginning of the Messinian crisis. Generally arid conditions coincide with the accepted timing for the Chimpanzee/hominid split, and record of Sahelanthropus tchadensis in Chad and Orrorin tugenensis in Kenya, although these fossils were found under locally wooded environment. The period from 6 to 4 Ma saw the appearance of Ardipithecus and diversification of Australopithecines occurring during a progressive increased tree cover in the broad-scale vegetation that culminated at 3.9 Ma, during A. anamensis time and before the first appearance of Australopithecus afarensis. Important variations in the vegetation occurred between 4 and 3 Ma, and many plant ecosystems were available to A.afarensis, a hominid which had a wide geographical distribution and persisted at Hadar under temporal climatic and environmental variability. The strongest and abrupt decline of forest pollen accompanied by an increase in the grass pollen was found at 2.7 Ma, more pronounced in the West than in East Africa. It was accompanied by a significant increase in C 4

  12. International Uranium Resources Evaluation Project (IUREP) orientation phase mission report: Cameroon. Draft

    International Nuclear Information System (INIS)

    Geology Branch with mapping and exploration services. Most of CAMEROON is underlain by Precambrian granites , anatexites, migmatites, gneisses, and schists. The NTEM complex in the south is Archean age. Most other areas are probably Lower Proterozoic, with some Middle Proterozoic inliers of the LOM, POLI, and MBALMAYO-BENGBIS, and the DJA series in the southeast. The DJA tillite is probably Upper Proterozoic. There are small remnant basins of Paleozoic volcanics, and larger basins and grabens of Middle-Upper Cretaceous. Tertiary rocks are present in the Coastal basins and the southeast. The Lake Chad depression is covered with Quaternary sands. All of the older rocks except the NTEM complex and the DJA series are within the Panafrican Mobile Belt. The border faults of the Cretaceous BENOUE graben are throughgoing crustal features. Tertiary intrusives and plateau basalts are found along the 'LINE OF CAMEROON', and volcanism has continued to present. Uranium exploration from 1950 to present has produced mostly negative results. Only one important prospect has been found at GOBLE-KITONGO, and has been the subject of repeated exploration from 195 8 to present. An enriched zone in syenite at LOLODORF is also under investigation. Anomalies on an airborne survey of the DJA series are being checked for mineralization similar to the FRANCEVILLIAN of GABON. Total expenditures that may be assigned to uranium are on the order of $10 million (U.S.). There are no uranium ore reserves or reasonably assured resources in CAMEROON. Speculative resources of 10,000 tonnes have been assigned to the LOLODORT syenite, and 5000 tonnes to the GOBLE-KITONGO prospect and Paleozoic volcanics at $130/kg. (U.S.). Favorable areas are the DJA series, syenites of the Panafrican granite and 'granites ultimes', Mesozoic-Cenozoic basins (especially DOUALA), LOM and MBALMAYO-BENGBIS series, POLI-MAROUA, and Lower Proterozoic/Archean gneiss and granite. Recommendations have been made for topical studies of

  13. Obituary: John W. Firor (1927-2007)

    Science.gov (United States)

    Gilman, Peter A.

    2009-12-01

    scientific division of NCAR (Roberts made it a requirement if he was to be NCAR Director). He chose John to be the new HAO Director. John was 33 then; his leadership potential was recognized very early. While Director of HAO, John presided over a very active scientific program that focused on non-equilibrium thermodynamics, radiative transfer, plasma physics, coronal spectroscopy, geomagnetism, physics of the Earth's upper atmosphere, and solar activity. Prominent scientists such as Jack Evans, Sydney Chapman, Gene Parker, Leo Goldberg and Donald Menzel visited to share their insights and enthusiasm with the HAO staff. John was also an active participant in HAO's well-known solar eclipse expeditions, traveling to New Guinea and to Lake Chad in Africa. Late in his tenure as HAO Director, he took the lead in helping to improve the involvement of the AAS in solar physics, and solar physicists in the AAS. Having led the AAS committee that planned its birth, he was the founding chair of the new Solar Physics Division. Much less importantly, he gave me a summer position in 1966 when I was joining the faculty at CU--that is when I first met John. In 1968, John became the Director of NCAR when Walter Roberts decided to split the directorship from the Presidency of UCAR. As NCAR Director, John had responsibility for a vastly broadened program compared to his HAO days. NCAR, the largest NSF supported research center, conducted research covering all of atmospheric sciences, as well as oceanography and solar-terrestrial physics. It also provided major observational and computational facilities to the atmospheric sciences community. John showed very quickly he understood and could guide all of it. I came to know John best during this period, because in 1971 he chose me to head the Advanced Study Program, which supported (and still supports) postdoctoral and graduate education. In that time, budgets were good, and NCAR was a relatively collegial, informal place. But in December 1973, that

  14. PERSPECTIVE: Dust, fertilization and sources

    Science.gov (United States)

    Remer, Lorraine A.

    2006-11-01

    fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the

  15. Limits to the availability of groundwater in Africa

    Science.gov (United States)

    Edmunds, W. Mike

    2012-06-01

    over much of Africa, therefore, is favourable to rural rather than urban development. One of the real opportunities presented in the paper is that groundwater should be more widely used for a revolution in rural development. To this end, the use of managed aquifer recharge (MAR), coupled with other forms of rainwater harvesting, can also locally conserve and augment groundwater resources and offer obvious advantages over building surface water storage. The large sedimentary aquifers of Africa contain some 0.66 million km3 in storage (MacDonald et al 2012); but most of this water (0.44 M km3) is contained beneath eight Saharan countries (see table 1, MacDonald et al 2012). This includes the Nubian Sandstone aquifer system, underlying Egypt, Libya, Sudan and Chad. In Libya this immense high yielding aquifer may be over 2.5 km thick (Pallas 1980) but considerable depths to the water table make for costly development. Water in Libya is currently being extracted (mined) from remote inland areas for transmission to the coast, from wells typically 300-500 m deep with estimated well-field lifetimes unlikely to exceed 50 years (Pallas and Salem 2001). This and the other Saharan aquifers are accessible only to a very small fraction of the African population. Groundwater extraction and transmission is possible only with the energy provided from the proximity of fossil fuels; large water transfer schemes are energy intensive and for most areas of Africa not an economic option, having also social and ecological consequences (Matete and Hassan 2005). Moreover a steady decline in water tables (typically from 0.5 to 2 m yr) has been taking place widely in semi-arid areas globally, mostly due to abstraction exceeding recharge, with consequences for both human requirements and ecosystems. Thus a major limiting factor is the need to identify whether the stored groundwater is a renewable or a non-renewable resource. In the case of deep basins such as the Saharan aquifers this water can be

  16. Descriptive Metaphysics, Natural Language Metaphysics, Sapir-Whorf, and All That Stuff: Evidence from the Mass-Count Distinction

    Directory of Open Access Journals (Sweden)

    Francis Jeffry Pelletier

    2010-12-01

    Institute of Generative Linguistics. Chapter 2: “Mass and Count Properties of Nouns and Verbs”.Dölling, Johannes. 1993. ‘Commonsense Ontology and Semantics of Natural Language’. Sprachtypologie und Universalienforschung 46: 133–141.Durst, Uwe. 2003. ‘The Natural Semantic Metalanguage Approach to Linguistic Meaning’. Theoretical Linguistics 29: 157–200.http://dx.doi.org/10.1515/thli.29.3.157Goddard, Cliff. 1994. ‘Semantic Theory and Semantic Universals’. In ‘Semantic and Lexical Universals’, 7–29. Philadelphia: J. Benjamins.Goddard, Cliff. 1998. Semantic Analysis: A Practical Introduction. Oxford: Oxford UP.Goddard, Cliff. 2002. ‘The Search for the Shared Semantic Core of All Languages’. In Goddard & Wierzbicka (2002, volume 1, pp. 5–40.Goddard, Cliff. 2009. ‘A Piece of Cheese, A Grain of Sand: The Semantics of Mass Nouns and Unitizers’. In Francis Jeffry Pelletier (ed. ‘Kinds, Things and Stuff’, 132–165. New York: Oxford UP.Goddard, Cliff & Wierzbicka, Anna. 2002. Meaning and Universal Grammar: Theory and Empirical Findings, Vols 1 & 2. Philadelphia: John Benjamins.Hansen, Chad. 1976. ‘Mass Nouns and ‘A White Horse Is Not a Horse”. Philosophy East and West 26: 189–209.http://dx.doi.org/10.2307/1398188Huddleston, Rodney & Pullum, Geoffrey. 2002. The Cambridge Grammar of the English Language. Cambridge: Cambridge UP.Iwasaki, Noriko, Vinson, David & Vigliocco, Gabriella. 2010. ‘Does the Grammatical Count/Mass Distiinction Affect Semantic Representations? Evidence from Experiments in English and Japanese’. Language and Cognitive Processes 25: 189–223.http://dx.doi.org/10.1080/01690960902978517Katz, Jerrold. 1981. Language and other Abstract Objects. Oxford: Blackwell.Krifka, Manfred. 1995. ‘Common Nouns: A Contrastive Analysis of English and Chinese’. In Gregory Carlson & Francis Jeffry Pelletier (eds. ‘The Generic Book’, 398–411. Chicago: University of Chicago Press.Latour. 1987. Science in Action: How to