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Sample records for african middle belt

  1. Addressing diarrhea prevalence in the West African Middle Belt: social and geographic dimensions in a case study for Benin

    Directory of Open Access Journals (Sweden)

    Arouna Aminou

    2008-04-01

    Full Text Available Abstract Background In West Africa, the Northern Sahelian zone and the coastal areas are densely populated but the Middle Belt in between is in general sparsely settled. Predictions of climate change foresee more frequent drought in the north and more frequent flooding in the coastal areas, while conditions in the Middle Belt will remain moderate. Consequently, the Middle Belt might become a major area for immigration but there may be constraining factors as well, particularly with respect to water availability. As a case study, the paper looks into the capacity of the Middle Belt zone of Benin, known as the Oueme River Basin (ORB, to reduce diarrhea prevalence. In Benin it links to the Millennium Development Goals on child mortality and environmental sustainability that are currently farthest from realization. However, diarrhea prevalence is only in part due to lack of availability of drinking water from a safe source. Social factors such as hygienic practices and poor sanitation are also at play. Furthermore, we consider these factors to possess the properties of a local public good that suffers from under provision and requires collective action, as individual actions to prevent illness are bound to fail as long as others free ride. Methods Combining data from the Demographic Health Survey with various spatial data sets for Benin, we apply mixed effect logit regression to arrive at a spatially explicit assessment of geographical and social determinants of diarrhea prevalence. Starting from an analysis of these factors separately at national level, we identify relevant proxies at household level, estimate a function with geo-referenced independent variables and apply it to evaluate the costs and impacts of improving access to good water in the basin. Results First, the study confirms the well established stylized fact on the causes of diarrhea that a household with access to clean water and with good hygienic practices will, irrespective of

  2. Meningococcal carriage in the African meningitis belt

    Science.gov (United States)

    2013-01-01

    A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVac#x2122;) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere. Un vaccin conjugué contenant un polysaccharide du sérogroupe A méningococcique et une anatoxine du tétanos (PsA-TT) (MenAfriVac™) est en cours de déploiement dans les pays de la ceinture africaine de la méningite. L’ expérience avec d’ autres vaccins conjugués polysaccharide/protéine a montré qu’ une partie importante de leur succès a été leur capacité à empêcher l’ acquisition du portage pharyngé et donc à arrêter la transmission et à induire une immunité de group. Si PsA-TT doit d’ atteindre l’ objectif de prévenir les épidémies, il devrait être en mesure d’ empêcher l’ acquisition du portage pharyngé ainsi que la méningococcie invasive et le fait que PsA-TT puisse emp

  3. Meningococcal carriage in the African meningitis belt

    Science.gov (United States)

    2013-01-01

    A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVac#x2122;) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere. Un vaccin conjugué contenant un polysaccharide du sérogroupe A méningococcique et une anatoxine du tétanos (PsA-TT) (MenAfriVac™) est en cours de déploiement dans les pays de la ceinture africaine de la méningite. L’ expérience avec d’ autres vaccins conjugués polysaccharide/protéine a montré qu’ une partie importante de leur succès a été leur capacité à empêcher l’ acquisition du portage pharyngé et donc à arrêter la transmission et à induire une immunité de group. Si PsA-TT doit d’ atteindre l’ objectif de prévenir les épidémies, il devrait être en mesure d’ empêcher l’ acquisition du portage pharyngé ainsi que la méningococcie invasive et le fait que PsA-TT puisse emp

  4. Middle East and North African Oil.

    Science.gov (United States)

    Al-Quazzaz, Ayad

    1981-01-01

    Traces the history of oil and natural gas in the Middle East and relates the importance of the Middle East's current stores of oil to economic development. Information is presented on the relationship of major oil companies and local governments, OPEC, rate of production, and the impact of oil on the societies of the Middle East and North Africa.…

  5. A Seroepidemiological Study of Serogroup A Meningococcal Infection in the African Meningitis Belt.

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    Olivier Manigart

    Full Text Available The pattern of epidemic meningococcal disease in the African meningitis belt may be influenced by the background level of population immunity but this has been measured infrequently. A standardised enzyme-linked immunosorbent assay (ELISA for measuring meningococcal serogroup A IgG antibodies was established at five centres within the meningitis belt. Antibody concentrations were then measured in 3930 individuals stratified by age and residence from six countries. Seroprevalence by age was used in a catalytic model to determine the force of infection. Meningococcal serogroup A IgG antibody concentrations were high in each country but showed heterogeneity across the meningitis belt. The geometric mean concentration (GMC was highest in Ghana (9.09 μg/mL [95% CI 8.29, 9.97] and lowest in Ethiopia (1.43 μg/mL [95% CI 1.31, 1.57] on the margins of the belt. The force of infection was lowest in Ethiopia (λ = 0.028. Variables associated with a concentration above the putative protective level of 2 μg/mL were age, urban residence and a history of recent vaccination with a meningococcal vaccine. Prior to vaccination with the serogroup A meningococcal conjugate vaccine, meningococcal serogroup A IgG antibody concentrations were high across the African meningitis belt and yet the region remained susceptible to epidemics.

  6. Meningococcal meningitis: vaccination outbreak response and epidemiological changes in the African meningitis belt.

    Science.gov (United States)

    Carod Artal, Francisco Javier

    2015-07-01

    The main approach to controlling epidemics of meningococcal meningitis in the African meningitis belt has been reactive vaccination campaigns with serogroup A polysaccharide vaccine once the outbreak reached an incidence threshold. Early reactive vaccination is effective in reducing morbidity and mortality. A recent paper in International Health has shown that earlier reactive vaccination campaigns may be even more effective than increasing the coverage area of vaccination. Monovalent serogroup A conjugate vaccine programs have recently been launched to prevent transmission in endemic areas in the African meningitis belt. Conjugate vaccines can induce immunological memory and have impact on pharyngeal carriage. However, reactive vaccination still has a role to play taking into account the dynamic changes in the epidemiology of meningitis in this area. PMID:25878213

  7. Household crowding, social mixing patterns and respiratory symptoms in seven countries of the African meningitis belt.

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    Claire F Ferraro

    Full Text Available OBJECTIVES: To describe the variation in household crowding and social mixing patterns in the African meningitis belt and to assess any association with self-reported recent respiratory symptoms. METHODS: In 2010, the African Meningococcal Carriage Consortium (MenAfriCar conducted cross-sectional surveys in urban and rural areas of seven countries. The number of household members, rooms per household, attendance at social gatherings and meeting places were recorded. Associations with self-reported recent respiratory symptoms were analysed by univariate and multivariate regression models. RESULTS: The geometric mean people per room ranged from 1.9 to 2.8 between Ghana and Ethiopia respectively. Attendance at different types of social gatherings was variable by country, ranging from 0.5 to 1.5 per week. Those who attended 3 or more different types of social gatherings a week (frequent mixers were more likely to be older, male (OR 1.27, p<0.001 and live in urban areas (OR 1.45, p<0.001. Frequent mixing and young age, but not increased household crowding, were associated with higher odds of self-reported respiratory symptoms (aOR 2.2, p<0.001 and OR 2.8, p<0.001 respectively. A limitation is that we did not measure school and workplace attendance. CONCLUSION: There are substantial variations in household crowding and social mixing patterns across the African meningitis belt. This study finds a clear association between age, increased social mixing and respiratory symptoms. It lays the foundation for designing and implementing more detailed studies of social contact patterns in this region.

  8. Identifying optimal vaccination strategies for serogroup A Neisseria meningitidis conjugate vaccine in the African meningitis belt.

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    Sara Tartof

    Full Text Available OBJECTIVE: The optimal long-term vaccination strategies to provide population-level protection against serogroup A Neisseria meningitidis (MenA are unknown. We developed an age-structured mathematical model of MenA transmission, colonization, and disease in the African meningitis belt, and used this model to explore the impact of various vaccination strategies. METHODS: The model stratifies the simulated population into groups based on age, infection status, and MenA antibody levels. We defined the model parameters (such as birth and death rates, age-specific incidence rates, and age-specific duration of protection using published data and maximum likelihood estimation. We assessed the validity of the model by comparing simulated incidence of invasive MenA and prevalence of MenA carriage to observed incidence and carriage data. RESULTS: The model fit well to observed age- and season-specific prevalence of carriage (mean pseudo-R2 0.84 and incidence of invasive disease (mean R2 0.89. The model is able to reproduce the observed dynamics of MenA epidemics in the African meningitis belt, including seasonal increases in incidence, with large epidemics occurring every eight to twelve years. Following a mass vaccination campaign of all persons 1-29 years of age, the most effective modeled vaccination strategy is to conduct mass vaccination campaigns every 5 years for children 1-5 years of age. Less frequent campaigns covering broader age groups would also be effective, although somewhat less so. Introducing conjugate MenA vaccine into the EPI vaccination schedule at 9 months of age results in higher predicted incidence than periodic mass campaigns. DISCUSSION: We have developed the first mathematical model of MenA in Africa to incorporate age structures and progressively waning protection over time. Our model accurately reproduces key features of MenA epidemiology in the African meningitis belt. This model can help policy makers consider vaccine

  9. Paleoproterozoic Greenstone-Granite Belts in Northern Brazil and the Former Guyana Shield - West African Craton Province

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    Ian McReath

    2006-03-01

    Full Text Available The mainly meta-volcano-sedimentary Vila Nova Group and associated granites constitute separate belts, which formpart of a large paleoproterozoic (mainly rhyacian province in the Guyana Shield of which northern Brazil forms a part, andthe West African Craton. In Brazil the southwestern Serra do Ipitinga and Serra Tumucumaque-Serra do Navio belts have noobvious geometrical extensions in the Guyanas or Venezuela, and may represent deposits formed at penecontemporaneouspassive continental margins and ocean floor spreading centres. To the Northeast the Serra Lombarda-Tartarugalzinho andOiapoque belts are continuations of Guianese belts. In the former the igneous rocks have geochemical characteristics ofsuprasubduction environments. Belts in the Guyana Shield and West African Craton have many similar features. Themegaprovince evolved in a number of stages, which may have started at about 2.3 Ga, and continued with diminished activityafter 2.11 Ga. Both major juvenile additions and (possibly minor reworking of earlier crust contributed to the growth of theprovince. The major transcurrent deformation, responsible for the present structure of the belts, probably occurred duringthe later stages of evolution of the province, but metamorphism and deformation are registered even in the oldest rocks.

  10. Northwest trending tectonic belt in the middle Yanshan Orogenic Belt of northeast Hebei Province, North China:Tectonic evolution and geochronology

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Changhou; WU; Ganguo; WANG; Genhou; ZHANG; Weijie

    2004-01-01

    The northwest trending tectonic belt in the middle part of the Mesozoic intraplate Yanshan Orogenic Belt, northeast Hebei Province, is composed of thrusts, extensional faults,strike-slip faults and syntectonic sedimentations as well. The northeastward basement-involved major thrusting deformation occurred between 174Ma and 168MaBP and was followed by an intrusion of the granitic plutonic rocks. As a part of the post-thrusting extensional deformations a northwest extending volcano-sedimentation system of Late Jurassic and Early Cretaceous formed in the southwest side of the belt. These volcano-sedimentary sequences are divided into Tuchengzi Formation, Zhangjiakou Formation, Yixian Formation and Jiufotang Formation respectively. They are characterized by southeastward migration as a result of the increasing down-dip slip displacement along the major extensional fault toward the southeast of the belt.The provenance area of the Jiufotang Formation north to it experienced southwestward thrusting during and after its later sedimentation. The thrusting in this stage resulted in the formation of an asymmetric footwall syncline with vergence to SW in the Jiufotang Formation in the NE side of the basin. Finally a dextral strike-slip deformation occurred along the NW tectonic belt. The striking tectono-geomorphological features and present seismic activities along this belt indicate that it has been being active since Cenozoic era and is still in the active state at present. This northwest extending tectonic belt was following the same direction and location as the existing fault systems within the basement as revealed by former geological and geophysical studies. So it is reasonable to infer the Mesozoic deformation along this belt to be a result of reactivation of the basement structures in a favorable tectonic stress field. The reactivation of basement structures might be taken as one of the mechanisms of intraplate deformation and orogeny.

  11. Structural and geochronological constraints on the Pan-African tectonic evolution of the northern Damara Belt, Namibia

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    Lehmann, Jérémie; Saalmann, Kerstin; Naydenov, Kalin V.; Milani, Lorenzo; Belyanin, George A.; Zwingmann, Horst; Charlesworth, Guy; Kinnaird, Judith A.

    2016-01-01

    The Pan-African Orogen formed by convergence of numerous continental blocks during the Neoproterozoic to early Cambrian. This convergence eventually led to amalgamation of Gondwana, a supercontinent crosscut by a network of highly oblique linear orogenic belts that locally intersect each other, as in NW Namibia, where the NNW trending Kaoko Belt joins the NE trending Damara Belt. The northern Damara Belt has preserved well three regional Pan-African tectonic events due to the dominance of weak Neoproterozoic marine sediments (Damara Supergroup) that have been affected by low-grade metamorphism. A newly discovered early N-S horizontal contraction, dated by 40Ar/39Ar at ~590 Ma, is tentatively linked to convergence between the Congo and Kalahari cratons. This was superseded by collision between the Congo and Rio de la Plata cratons between 580 and 530 Ma that thickened and exhumed the orogenic crust of the Kaoko Belt and produce upper crustal N-S oriented folds of earlier fold trains and associated axial planar schistosities in the northern Damara Belt. A switch from E-W to NW-SE horizontal shortening occurred at ~530 Ma as a result of collision with the Kalahari Craton, triggering extensive syn-orogenic magmatism in the entire Damara Belt. During this last event, southward indentation and underthrusting of the Congo Craton promontory below the Neoproterozoic cover sequences produced a deformation front in the northern Damara Belt. Our results show that highly oblique convergent processes competed over a period of ~120 Ma to build Gondwana in Namibia during the late Neoproterozoic to early Cambrian.

  12. Uranium cycle and tectono-metamorphic evolution of the Lufilian Pan-African orogenic belt (Zambia)

    International Nuclear Information System (INIS)

    Uranium is an incompatible and lithophile element, and thus more concentrated in silicate melt produced by the partial melting of the mantle related to continental crust formation. Uranium can be used as a geochemical tracer to discuss the generation and the evolution of continental crust. This thesis, focused on the Pan-African Lufilian belt in Zambia, combines structural geology, metamorphic petrology and thermos-barometry, fluid inclusions, geochemistry and geochronology in order to characterize the uranium cycle for this crustal segment. Silici-clastic and evaporitic sediments have been deposited within an intra-continental rift during the dislocation of the Rodinia super-continent during the early Neo-proterozoic. U-Pb ages on detrital zircon grains in these units indicate a dominant Paleo-proterozoic provenance. The same zircon grains show sub-chondritic εHf (between 0 and -15) and yield Hf model ages between ∼2.9 and 2.5 Ga. These data suggest that the continental crust was generated before the end of the Archean (< 2.5 Ga) associated with uranium extraction from the mantle. This old crust has been reworked by deformation and metamorphism during the Proterozoic. Uranium has been re-mobilized and reconcentrated during several orogenic cycles until the Pan-African orogeny. During this Pan-African cycle, U-Pb and REY (REE and Yttrium) signatures of uranium oxides indicate a first mineralizing event at ca. 650 Ma during the continental rifting. This event is related to late diagenesis hydrothermal processes at the basement/cover interface with the circulation of basinal brines linked to evaporites of the Roan. The second stage, dated at 530 Ma, is connected to metamorphic highly saline fluid circulations, synchronous to the metamorphic peak of the Lufilian orogeny (P=9±3 kbar; T=610±30 deg. C). These fluids are derived from the Roan evaporite dissolution. Some late uranium re-mobilizations are described during exhumation of metamorphic rocks and their

  13. A Case Study of Middle Class African American Males Taking Advanced Mathematics Classes in High School

    OpenAIRE

    Jones, Zella Higginbotham

    2011-01-01

    African American males in all socioeconomic levels are underperforming in school. Many researchers have conducted studies hoping to find reasons for the underperformance. This study focused on three middle class African American males in a suburban school district. These African American male students took upper level math courses that included Algebra III, Math Analysis, AP Calculus, and AP Statistics. This study modeled the study by E. Wayne Harris. He believed students were influenced...

  14. Understanding consumption patterns of the established and emerging South African black middle class

    OpenAIRE

    Ronelle Burger; Megan Louw; Brigitte Barbara Isabel de Oliveira Pegado; Servaas van der Berg

    2014-01-01

    Existing empirical research on consumption patterns of the South African black middle class leans either on the theory of conspicuous consumption or culture-specific utility functions. This paper departs from treatment of the black middle class as a homogenous group. By differentiating between a securely established group, with characteristics and consumption patterns similar to the white middle class, and an emerging group, often with weaker productive characteristics, it formally introduces...

  15. Radiation belt electron precipitation in the upper ionosphere at middle latitudes before strong earthquakes

    CERN Document Server

    Anagnostopoulos, G; Vassiliadis, E

    2010-01-01

    In this article we present examples of a wider study of space-time correlation of electron precipitation event of the Van Allen belts with the position and time of occurrence of strong (M>6.5) earthquakes. The study is based on the analysis of observations of electron bursts (EBs) with energies 70 - 2350 keV at middle geographic latitudes, which were detected by DEMETER satellite (at an altitude of ~700 km). The EBs show a relative peak-to-background increase usually < 100, they have a time duration ~0.5 - 3 min, energy spectrum with peaks moving in higher energies as the satellite moves towards the equator, and highest energy limit <~500 keV. The EBs are observed in the presence of VLF waves. The flux-time profile of the EBs varies in East Asia and Mediterranean Sea at the similar geographic latitudes, due to the differentiation of the magnitude of the earth's magnetic field. The most important result of our study is the characteristic temporal variation of electron precipitation variation which begins...

  16. Strong Lg-wave attenuation in the Middle East continental collision orogenic belt

    Science.gov (United States)

    Zhao, Lian-Feng; Xie, Xiao-Bi

    2016-04-01

    Using Lg-wave Q tomography, we construct a broadband crustal attenuation model for the Middle East. The QLg images reveal a relationship between attenuation and geological structures. Strong attenuation is found in the continental collision orogenic belt that extends from the Turkish and Iranian plateau to the Pamir plateau. We investigate the frequency dependence of QLg in different geologic formations. The results illustrate that QLg values generally increase with increasing frequency but exhibit complex relationships both with frequency and between regions. An average QLg value between 0.2 and 2.0 Hz, QLg (0.2-2.0 Hz), may be a critical index for crustal attenuation and is used to infer the regional geology. Low-QLg anomalies are present in the eastern Turkish plateau and correlate well with low Pn-velocities and Cenozoic volcanic activity, thus indicating possible partial melting within the crust in this region. Very strong attenuation is also observed in central Iran, the Afghanistan block, and the southern Caspian Sea. This in line with the previously observed high crustal temperature, high-conductivity layers, and thick marine sediments in these areas, suggests the high Lg attenuation is caused by abnormally high tectonic and thermal activities.

  17. Teachers' Perception of African American Middle School Girls' Interest in Mathematics and Science

    Science.gov (United States)

    Best, Bonnie M.

    Research into African American female underrepresentation in science, technology, engineering, and mathematics (STEM) fields has become an area of interest due to the fact that a majority of African American middle school females do not possess the high levels of mathematics and science knowledge because of social and cultural barriers both inside and outside school that challenge their academic success. The purpose of this qualitative interpretative phenomenological study was to explore teachers' shared, lived experiences of teaching mathematics and science to African American middle school girls. Delgado and Stefancic's critical race theory, Pratt-Clarke's critical race feminism, and Baker-Miller's relational-cultural theory were used to guide this study. Research questions focused on the perceptions and experiences of teachers' lived experiences teaching mathematics and science to African American middle school females. Criterion, purposive, and maximum variation sampling techniques were used to recruit 10 teachers who have 3 or more years' experience teaching African American middle school girls. Semistructured face-to-face interviews were the primary data collection source. First cycle and second cycle coding methods were used to support the analysis of this study. Findings suggest that there is a connection between a positive student-teacher relationship and academic success. The results of this study contribute to positive social change by providing empirical evidence policymakers and teachers can use to improve the mathematics and science instruction and practices that are needed to meet the needs of African American middle school females and reduce the underrepresentation and underachievement of African American females in mathematics and science.

  18. The Learning Environment and the Reading Achievement of Middle School African American Male Students in a Suburban School Setting

    Science.gov (United States)

    Frazier, Nicole Denise

    2012-01-01

    The reading achievement of African American males might be impacted by a host of variables. This study was undertaken to determine if there was a difference in the culturally responsive characteristics present in the learning environment of a middle school and the reading achievement of middle school African American males. The purpose of this…

  19. David Haynes: Chronicler of the African American Middle Class.

    Science.gov (United States)

    Barron, Ronald

    1997-01-01

    Profiles writer David Haynes, and discusses his four novels (an award-winning young adult book and three novels for the adult market). Concludes that Haynes' success as a novelist is due to his characters, a healthy dose of humor, and his realistic depiction of a wide range of African American characters without resorting to sensationalism or…

  20. Clonal waves of Neisseria colonisation and disease in the African meningitis belt: eight- year longitudinal study in northern Ghana.

    Directory of Open Access Journals (Sweden)

    Julia Leimkugel

    2007-03-01

    Full Text Available BACKGROUND: The Kassena-Nankana District of northern Ghana lies in the African "meningitis belt" where epidemics of meningococcal meningitis have been reoccurring every eight to 12 years for the last 100 years. The dynamics of meningococcal colonisation and disease are incompletely understood, and hence we embarked on a long-term study to determine how levels of colonisation with different bacterial serogroups change over time, and how the patterns of disease relate to such changes. METHODS AND FINDINGS: Between February 1998 and November 2005, pharyngeal carriage of Neisseria meningitidis in the Kassena-Nankana District was studied by twice-yearly colonisation surveys. Meningococcal disease was monitored throughout the eight-year study period, and patient isolates were compared to the colonisation isolates. The overall meningococcal colonisation rate of the study population was 6.0%. All culture-confirmed patient isolates and the majority of carriage isolates were associated with three sequential waves of colonisation with encapsulated (A ST5, X ST751, and A ST7 meningococci. Compared to industrialised countries, the colonising meningococcal population was less constant in genotype composition over time and was genetically less diverse during the peaks of the colonisation waves, and a smaller proportion of the isolates was nonserogroupable. We observed a broad age range in the healthy carriers, resembling that of meningitis patients during large disease epidemics. CONCLUSIONS: The observed lack of a temporally stable and genetically diverse resident pharyngeal flora of meningococci might contribute to the susceptibility to meningococcal disease epidemics of residents in the African meningitis belt. Because capsular conjugate vaccines are known to impact meningococcal carriage, effects on herd immunity and potential serogroup replacement should be monitored following the introduction of such vaccines.

  1. Van Allen Probes Mission Space Academy: Educating middle school students about Earth's mysterious radiation belts

    Science.gov (United States)

    Butler, L.; Turney, D.; Matiella Novak, A.; Smith, D.; Simon, M.

    2013-12-01

    How's the weather in space? Why on Earth did NASA send two satellites above Earth to study radiation belts and space weather? To learn the answer to questions about NASA's Van Allen Probes mission, 450 students and their teachers from Maryland middle schools attended Space Academy events highlighting the Van Allen Probes mission. Sponsored by the Applied Physics Laboratory (APL) and Discovery Education, the events are held at the APL campus in Laurel, MD. Space Academies take students and teachers on behind-the-scenes exploration of how spacecraft are built, what they are designed to study, and introduces them to the many professionals that work together to create some of NASA's most exciting projects. Moderated by a public relations representative in the format of an official NASA press conference, the daylong event includes a student press conference with students as reporters and mission experts as panelists. Lunch with mission team members gives students a chance to ask more questions. After lunch, students don souvenir clean room suits, enjoy interactive science demonstrations, and tour APL facilities where the Van Allen Probes were built and tested before launch. Students may even have an opportunity to peek inside a clean room to view spacecraft being assembled. Prior to the event, teachers are provided with classroom activities, lesson plans, and videos developed by APL and Discovery Education to help prepare students for the featured mission. The activities are aligned to National Science Education Standards and appropriate for use in the classroom. Following their visit, student journalists are encouraged to write a short article about their field trip; selections are posted on the Space Academy web site. Designed to engage, inspire, and influence attitudes about space science and STEM careers, Space Academies provide an opportunity to attract underserved populations and emphasize that space science is for everyone. Exposing students to a diverse group of

  2. Juxtaposition of Neoproterozoic units along the Baruda - Tulu Dimtu shear-belt in the East African Orogen of western Ethiopia

    Science.gov (United States)

    Braathen, A.; Grenne, Tor; Selassie, M.G.; Worku, T.

    2001-01-01

    Amalgamation of East and West Gondwanaland during the Neoproterozoic East African Orogen is recorded by several shear-belts or 'suture zones', some of which are associated with ultramafic and mafic complexes that have been interpreted as ophiolite fragments. The Baruda shear-belt is a major structure of this type that belongs to the N-S trending Barka - Tulu Dimtu zone. The significance of this zone has been studied within a transect in western Ethiopia which covers a variety of metasedimentary and metavolcanic sequences, ultramafic rocks and synkinematic intrusive complexes. All rocks participated in the regional D1 event as reflected in a penetrative steep foliation in supracrustal rocks and marginal parts of the intrusions. Highly strained rocks contain a stretching lineation that plunge to the east. The several-km thick Baruda shear-belt, comprising mylonitic supracrustal and plutonic rocks including mafic-ultramafic mega-lenses, is the most prominent expression of this event. Shear-sense indicators demonstrate top-to-the-west shear. Subsequent D2 deformation is recorded in 2-300 m wide, N-S striking, subvertical shear-zones with subhorizontal stretching lineation relatable to sinistral transcurrent movements. Our data indicate that rock units on either side of the Baruda shear-belt are related, rather than being exotic to each other as implied in suture zone models, since there is no major lithologic or metamorphic difference, geochemical data on metavolcanic rocks and pre-tectonic intrusions suggest a paleotectonic link, and style and extent of deformation is similar across the shear-belt. A tentative model for the transect suggests an arc and back-arc setting which experienced later continental collision and tectonic shortening. The initial setting was that of a shallow marine platform characterised by carbonates and sandstones, which covered extensive areas prior to break-up of a pre-existing supercontinent. Continental convergence is first recorded in high

  3. Hydrogeochemical characterization of stream waters with application of multivariate statistical method for the Middle Ogcheon Fold Belt

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin-Soo; Ko, Kyung-Seok [Korea Institute of Geoscience and Mineral Resources, Taejeon(Korea)

    2001-12-01

    Stream waters in the middle part of the Ogcheon Fold Belt were studied in terms of hydrogeochemistry. Geochemical characteristics of the steam water were analyzed by the application of multivariate statistical method, and therefrom natural background effects of geology and those of human activities of the water were interpreted by employing factorial kriging technique. According to the study results, hydrochemistry of the study area is highly correlatable with 1) the values or contents of electrical conductivity, HCO{sub 3}, Ca and Ba, which depend largely on the geology and human activities, and 2) the high concentration of Al, Mn and SO{sub 4} resulted from the given mineralogical constituents in the rocks mainly of the Ogcheon Group and subordinately of the Gyeongsang Supergroup. (author). 14 refs., 3 tabs., 9 figs.

  4. Characterizing the learning styles and testing the science-related attitudes of African American middle school students: Implications for the underrepresentation of African Americans in the sciences

    Science.gov (United States)

    Perine, Donald Ray

    African Americans, Hispanics, Native Americans and women are underrepresented among the population of scientists and science teachers in the United States. Specifically, the shortage of African Americans teaching math and science at all levels of the educational process and going into the many science-related fields is manifested throughout the entire educational and career structure of our society. This shortage exists when compared to the total population of African Americans in this country, the population of African American students, and to society's demand for more math and science teachers and professionals of all races. One suggestion to address this problem is to update curricular and instructional programs to accommodate the learning styles of African Americans from elementary to graduate school. There is little in the published literature to help us understand the learning styles of African American middle school students and how they compare to African American adults who pursue science careers. There is also little published data to help inform us about the relationship between learning styles of African American middle school students and their attitudes toward science. The author used a learning styles inventory instrument to identify the learning style preferences of the African American students and adults. The preferences identified describe how African American students and African American adult science professionals prefer to function, learn, concentrate, and perform in their educational and work activities in the areas of: (a) immediate environment, (b) emotionality, (c) sociological needs, and (d) physical needs. The learning style preferences for the students and adults were not significantly different in key areas of preference. A Test of Science-Related Attitudes (TOSRA) was used to measure seven distinct science-related attitudes of the middle school students. A comparison of the profile of the mean scores for the students in this study

  5. Examining science achievement of African American females in suburban middle schools: A mixed methods study

    Science.gov (United States)

    Topping, Kecia C.

    This dissertation examined factors that affected the science achievement of African American females in suburban middle schools. The research literature informed that African American females are facing the barriers of race, gender, socioeconomic status, and cultural learning style preferences. Nationally used measurements of science achievement such as the Standardized Achievement Test, Tenth edition (SAT-10), National Assessment for Educational Progress, and National Center for Educational Statistics showed that African American females are continuing to falter in the areas of science when compared to other ethnic groups. This study used a transformative sequential explanatory mixed methods design. In the first, quantitative, phase, the relationships among the dependent variables, science subscale SAT-10 NCE scores, yearly averages, and the independent variables, attitude toward science scores obtained from the Modified Fennema-Sherman Attitudes toward Science Scale, socioeconomics, and caregiver status were tested. The participants were 150 African American females in grades 6 through 8 in four suburban middle schools located in the Southeastern United States. The results showed a positive, significant linear relationship between the females' attitude and their science subscale SAT-10 NCE scores and a positive, significant linear relationship between the females' attitudes and their yearly averages in science. The results also confirmed that attitude was a significant predictor of science subscale SAT-10 NCE scores for these females and that attitude and socioeconomics were significant predictors of the females' yearly averages in science. In the second, qualitative, phase, nine females purposefully selected from those who had high and low attitude towards science scores on the scale in the quantitative phase were interviewed. The themes that emerged revealed seven additional factors that impacted the females' science achievement. They were usefulness of science

  6. The current assessment of foreign direct investment in the Middle East and North African region

    OpenAIRE

    Al-Khouri, Ritab

    2014-01-01

    This research aims to assess the growth and the current status of foreign direct investment (FDI) in a sample of 16 Middle East and North African (MENA) countries over the period 1984-2011. Our goal is to give some insight on the importance of the different factors affecting foreign direct investment (FDI). To reach our goals, we will examine the growth of FDI over time in the MENA region as compared to that of other regions. Second, we will determine the most important factors that promote F...

  7. Celiac disease in Middle Eastern and North African countries:A new burden?

    Institute of Scientific and Technical Information of China (English)

    Kassem; Barada; Abbas; Bitar; Mohamad; Abdul-Razak; Mokadem; Jana; Ghazi; Hashash; Peter; Green

    2010-01-01

    Celiac disease(CD) is now recognized as a common disorder among Middle Eastern(ME) and North African(NA) populations.The aim of this review is to assess the available data regarding CD in the ME and NA and to compare this information with that of Western countries.A literature review was performed using the electronic databases PubMed and Medline(1950-2008) as search engines,and "celiac disease" was used as a Mesh term.The search was limited to ME and NA countries.The prevalence of CD in ME and NA countries...

  8. The Nubian Complex of Dhofar, Oman: an African middle stone age industry in Southern Arabia.

    Directory of Open Access Journals (Sweden)

    Jeffrey I Rose

    Full Text Available Despite the numerous studies proposing early human population expansions from Africa into Arabia during the Late Pleistocene, no archaeological sites have yet been discovered in Arabia that resemble a specific African industry, which would indicate demographic exchange across the Red Sea. Here we report the discovery of a buried site and more than 100 new surface scatters in the Dhofar region of Oman belonging to a regionally-specific African lithic industry--the late Nubian Complex--known previously only from the northeast and Horn of Africa during Marine Isotope Stage 5, ∼128,000 to 74,000 years ago. Two optically stimulated luminescence age estimates from the open-air site of Aybut Al Auwal in Oman place the Arabian Nubian Complex at ∼106,000 years ago, providing archaeological evidence for the presence of a distinct northeast African Middle Stone Age technocomplex in southern Arabia sometime in the first half of Marine Isotope Stage 5.

  9. How African American, Middle Class Parents Learn and Enact a Racism Resistant Critical Race Achievement Ideology in Their Adolescents in Gifted and AP Classes

    Science.gov (United States)

    Fisher, Tracey Simmons

    2015-01-01

    The purpose of this qualitative study was to examine African American, middle class parents' facilitation of an academic achievement ideology that is racism-resistant in their adolescent offspring in AP and Gifted Education classrooms. Three research questions guided the study: (1) how do African American, middle class parents come to acquire or…

  10. Haematological and biochemical reference values for healthy adults in the middle belt of Ghana.

    Directory of Open Access Journals (Sweden)

    David K Dosoo

    Full Text Available BACKGROUND: Reference values are very important in clinical management of patients, screening participants for enrollment into clinical trials and for monitoring the onset of adverse events during these trials. The aim of this was to establish gender-specific haematological and biochemical reference values for healthy adults in the central part of Ghana. METHODS: A total of 691 adults between 18 and 59 years resident in the Kintampo North Municipality and South District in the central part of Ghana were randomly selected using the Kintampo Health and Demographic Surveillance System and enrolled in this cross-sectional survey. Out of these, 625 adults made up of 316 males and 309 females were assessed by a clinician to be healthy. Median values and nonparametric 95% reference values for 16 haematology and 22 biochemistry parameters were determined for this population based on the Clinical Laboratory and Standards Institute guidelines. Values established in this study were compared with the Caucasian values being used currently by our laboratory as reference values and also with data from other African and western countries. RESULTS: REFERENCE VALUES ESTABLISHED INCLUDE: haemoglobin 113-164 g/L for males and 88-144 g/L for females; total white blood cell count 3.4-9.2 × 10(9/L; platelet count 88-352 × 10(9/L for males and 89-403 × 10(9/L for females; alanine aminotransferase 8-54 U/L for males and 6-51 U/L for females; creatinine 56-119 µmol/L for males and 53-106 µmol/L for females. Using the haematological reference values based on the package inserts would have screened out up to 53% of potential trial participants and up to 25% of the population using the biochemical parameters. CONCLUSION: We have established a panel of locally relevant reference parameters for commonly used haematological and biochemical tests. This is important as it will help in the interpretation of laboratory results both for clinical management of patients and

  11. Incidence, carriage and case-carrier ratios for meningococcal meningitis in the African meningitis belt: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Thibaut Koutangni

    Full Text Available To facilitate the interpretation of meningococcal meningitis epidemiology in the "African meningitis belt", we aimed at obtaining serogroup-specific pooled estimates of incidence, carriage and case-carrier ratios for meningococcal meningitis in the African meningitis belt and describe their variations across the endemic, hyperendemic and epidemic context.We conducted a systematic review and meta-analysis of studies reporting serogroup-specific meningococcal meningitis monthly incidence and carriage in the same population and time period. Epidemiological contexts were defined as endemic (wet season, no epidemic, hyperendemic (dry season, no epidemic, and epidemic (dry season, epidemic.Eight studies reporting a total of eighty pairs of serogroup-specific meningococcal meningitis incidence and carriage estimates were included in this review. For serogroup A, changes associated with the transition from endemic to hyperendemic incidence and from hyperendemic to epidemic incidence were 15-fold and 120-fold respectively. Changes in carriage prevalence associated with both transitions were 1-fold and 30-fold respectively. 
For serogroup W and X, the transition from endemic to hyperendemic incidence involved a 4-fold and 1•1-fold increase respectively. Increases in carriage prevalence for the later transition were 7-fold and 1•7-fold respectively. No data were available for the hyperendemic-epidemic transition for these serogroups. Our findings suggested that the regular seasonal variation in serogroup A meningococcal meningitis incidence between the rainy and the dry season could be mainly driven by seasonal change in the ratio of clinical cases to subclinical infections. In contrast appearance of epidemic incidences is related to a substantial increase in transmission and colonisation and to lesser extent with changes in the case-carrier ratio.Seasonal change in the rate of progression to disease given carriage together with variations in

  12. The nature of culturally responsive pedagogy in two urban African American middle school science classrooms

    Science.gov (United States)

    Bondima, Michelle Harris

    This ethnographic in nature study explores how two middle school science teachers who have classes populated by urban African Americans teach their students and how their students perceive their teaching. Since urban African American students continue to perform lower than desired on measures of science achievement, there is an urgent need to understand what pedagogical methodologies assist and hinder urban African American students in achieving higher levels of success in science. A pedagogical methodology that theorists posit assists subordinated school populations is culturally responsive pedagogy. Culturally responsive pedagogy is defined as a teaching methodology concerned with preparing students to question inequality, racism, and injustice. Teachers who use culturally responsive pedagogy respect the culture students bring to the class, and require that the teachers willingly do whatever is necessary to educate students (Nieto, 2000). The teacher participants were two female African Americans who were identified by their school supervisors as being highly effective with urban African American students. The researcher presented the teachers in separate case studies conducted over a data collection period of nine months. Data were collected by participant observation, interviews, and artifact collection. Data were analyzed by application of grounded theory techniques. Findings of the teachers' (and the students') beliefs about pedagogy that both assisted and hindered the students' performance in science were reported in a rich and nuanced storytelling manner based on multiple perspectives (teachers', students', and the researcher's). Pedagogical methodologies that the teachers used that assisted their students were the use of cultural metaphors and images in science and applications of motivational techniques that encouraged a nurturing relationship between the teacher and her students. Pedagogical methodologies that hindered students varied by teacher

  13. Dating Violence and Sexual Assault Prevention with African American Middle Schoolers: Does Group Gender Composition Impact Dating Violence Attitudes?

    Science.gov (United States)

    Black, Beverly M.; Weisz, Arlene N.; Jayasundara, Dheeshana S.

    2012-01-01

    A dating violence and sexual assault prevention program was presented to 396, predominately African American, middle schoolers in two inner city schools in the United States. In one school the program was offered with a same-gender group composition; in the other school, the same program was offered with mixed-gender group composition. A…

  14. Middle-Class African American Adolescents' and Parents' Conceptions of Parental Authority and Parenting Practices: A Longitudinal Investigation.

    Science.gov (United States)

    Smetana, Judith G.

    2000-01-01

    Examined longitudinally conceptions of parental authority and ratings of parental rules and decision-making among middle- class African American adolescents and their parents. Found that nearly all subjects affirmed parents' legitimate authority to regulate and children's obligation to comply regarding oral, conventional, prudential, friendship,…

  15. Large scale prediction of soil properties in the West African yam belt based on mid-infrared soil spectroscopy

    Science.gov (United States)

    Baumann, Philipp; Lee, Juhwan; Paule Schönholzer, Laurie; Six, Johan; Frossard, Emmanuel

    2016-04-01

    Yam (Dioscorea sp.) is an important staple food in West Africa. Fertilizer applications have variable effects on yam tuber yields, and a management option solely based on application of mineral NPK fertilizers may bear the risk of increased organic matter mineralization. Therefore, innovative and sustainable nutrient management strategies need to be developed and evaluated for yam cultivation. The goal of this study was to establish a mid-infrared soil spectroscopic library and models to predict soil properties relevant to yam growth. Soils from yam fields at four different locations in Côte d'Ivoire and Burkina Faso that were representative of the West African yam belt were sampled. The project locations ranged from the humid forest zone (5.88 degrees N) to the northern Guinean savannah (11.07 degrees N). At each location, soils of 20 yam fields were sampled (0-30 cm). For the location in the humid forest zone additional 14 topsoil samples from positions that had been analyzed in the Land Degradation Surveillance Framework developed by ICRAF were included. In total, 94 soil samples were analyzed using established reference analysis protocols. Besides soils were milled and then scanned by fourier transform mid-infrared spectroscopy in the range between 400 and 4000 reciprocal cm. Using partial least squares (PLS) regression, PLS1 calibration models that included soils from the four locations were built using two thirds of the samples selected by Kennard-Stones sampling algorithm in the spectral principal component space. Models were independently validated with the remaining data set. Spectral models for total carbon, total nitrogen, total iron, total aluminum, total potassium, exchangeable calcium, and effective cation exchange capacity performed very well, which was indicated by R-squared values between 0.8 and 1.0 on both calibration and validation. For these soil properties, spectral models can be used for cost-effective, rapid, and accurate predictions

  16. Urban African-American middle school science students: Does standards-based teaching make a difference?

    Science.gov (United States)

    Butler Kahle, Jane; Meece, Judith; Scantlebury, Kathryn

    2000-11-01

    The current reform movement in science education promotes standards-based teaching, including the use of inquiry, problem solving, and open-ended questioning, to improve student achievement. This study examines the influence of standards-based teaching practices on the achievement of urban, African-American, middle school science students. Science classes of teachers who had participated in the professional development (n = 8) of Ohio's statewide systemic initiative (SSI) were matched with classes of teachers (n = 10) who had not participated. Data were gathered using group-administered questionnaires and achievement tests that were specifically designed for Ohio's SSI. Analyses indicate that teachers who frequently used standards-based teaching practices positively influenced urban, African-American students' science achievement and attitudes, especially for boys. Additionally, teachers' involvement in the SSI's professional development was positively related to the reported use of standards-based teaching practices in the classroom. The findings support the efficacy of high-quality professional development to change teaching practices and to enhance student learning.

  17. Basement Characteristics and Crustal Evolution of the Copper-Gold Metallogenic Belt in the Middle and Lower Reaches of the Yangtze River: Some Isotope Constraints

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Studies of the Pb, Sr and Nd isotopic composition of Mesozoic intrusive rocks indicate that the basement of the copper-gold metallogenic belt of the middle and lower reaches of the Yangtze River has "two-layer structure" and partly has "multi-layered structure", and is inhomogeneous and shows the distinct feature of E-W provincialism. The calculated model lead ages (t1) are mostly greater than 2600 Ma, and the model neodymium ages (TDM) vary from 953 to 2276 Ma and concentrate in two time intervals: 1800- 2000 Ma and 1200- 1600 Ma. It is concluded that the basement of the MBYR is composed of the Late Archaeozoic to Middle Proterozoic metamorphic series and that the crust was initiated in the Archaean and continued to grow in the Early and Middle Proterozoic, and the proportion of new crust formed by mantle differentiation during the Late Proterozoic is low.

  18. Tectono-metamorphic evolution of the internal zone of the Pan-African Lufilian orogenic belt (Zambia): Implications for crustal reworking and syn-orogenic uranium mineralizations

    Science.gov (United States)

    Eglinger, Aurélien; Vanderhaeghe, Olivier; André-Mayer, Anne-Sylvie; Goncalves, Philippe; Zeh, Armin; Durand, Cyril; Deloule, Etienne

    2016-01-01

    The internal zone of the Pan-African Lufilian orogenic belt (Zambia) hosts a dozen uranium occurrences mostly located within kyanite micaschists in a shear zone marking the contact between metasedimentary rocks attributed to the Katanga Neoproterozoic sedimentary sequence and migmatites coring domes developed dominantly at the expense of the pre-Neoproterozoic basement. The P-T-t-d paths reconstructed for these rocks combining field observations, microstructural analysis, metamorphic petrology and thermobarometry and geochronology indicate that they have recorded burial and exhumation during the Pan-African orogeny. Both units of the Katanga metasedimentary sequence and pre-Katanga migmatitic basement have underwent minimum peak P-T conditions of ~ 9-11 kbar and ~ 640-660 °C, dated at ca. 530 Ma by garnet-whole rock Lu-Hf isochrons. This suggests that this entire continental segment has been buried up to a depth of 40-50 km with geothermal gradients of 15-20 °C.km- 1 during the Pan-African orogeny and the formation of the West Gondwana supercontinent. Syn-orogenic exhumation of the partially molten root of the Lufilian belt is attested by isothermal decompression under P-T conditions of ~ 6-8 kbar at ca. 530-500 Ma, witnessing an increase of the geothermal gradients to 25-30 °C·km- 1. Uranium mineralizations that consist of uraninite and brannerite took place at temperatures ranging from ~ 600 to 700 °C, and have been dated at ca. 540-530 Ma by U-Pb ages on uraninite. The main uranium deposition thus occurred at the transition from the syn-orogenic burial to the syn-orogenic exhumation stages and has been then partially transposed and locally remobilized during the post-orogenic exhumation accommodated by activation of low-angle extensional detachment.

  19. Retired African American female urban middle school science teachers' beliefs and practices

    Science.gov (United States)

    Whitney, Frances M.

    The purpose of this paper is to give a voice to a dedicated group of professionals who unselfishly labored twenty-five plus years educating the children of America's poorest taxpaying citizens. These retired African American female urban middle school science teachers (RAAFUMSST) explain the experiences that gave them the fortitude to stay in the urban school system until their retirement. The goal is to give you a glimpse into the distractions, challenges, and victories the teachers encountered as they strove to teach science in an overcrowded, underserviced, and depressed urban school district of a major city. Most times sacrificing self for service, the participants of this study held fast to their beliefs that all of America's children, regardless of their parents' socioeconomic status, deserve a quality education. It is through individual interviews that the five retired science teachers of this project share their reflections on the events and circumstances that altered their labor of love. Critical Race Theory (CRT) serves as the theoretical frame for this study.

  20. Crustal structure and geodynamics of the Middle and Lower reaches of Yangtze metallogenic belt and neighboring areas: Insights from deep seismic reflection profiling

    Science.gov (United States)

    Lü, Qingtian; Shi, Danian; Liu, Zhendong; Zhang, Yongqian; Dong, Shuwen; Zhao, Jinhua

    2015-12-01

    A 300 km long seismic reflection profile was acquired across the Middle and Lower Reaches of the Yangtze River (MLY) metallogenic belt and its adjacent areas. The objective of the survey was to establish the deep architecture and geodynamic framework of the region. Results based on the interpretation of the deep seismic data include (1) Tan-Lu fault appears as a subvertical thrust fault or transpression fault with its deep portion dipping toward the southeast; (2) the Zhangbaling uplift is squeezed out along this fault; (3) complex upper crustal deformation structures beneath the Chuquan depression include both kink bands, thrusts, imbrication and fold structures reflecting contraction deformation, and detachment fault and normal-fault structures reflecting extensional deformation; (4) the "crocodile" reflection structure emerging beneath the Tan-Lu fault and Ningwu-Lishui volcanic basin, which represents the decoupled deformation process of the upper and lower crust associated with intra-continental subduction; (5) further to the southeast, the upper crust deformation shows a large-scale "wave-form" pattern, making crustal scale syncline and anticline; (6) the entire section of the reflection Moho is clearly discernible at depth of 30.0-34.5 km, and the Moho beneath the Middle and Lower Reaches of Yangtze River metallogenic belt is shallowest, while the Moho beneath the North China block is deeper than that beneath the Yangtze block. The Moho offsets could be seen beneath the Ningwu volcanic basin. The seismic reflection data suggest that lithosphere delamination and asthenosphere upwelling that may result from the Mesozoic intra-continental orogenesis is responsible for the formation of large scale magmatism and mineralization in the MLY metallogenic belt.

  1. Eicosanoid Production following One Bout of Exercise in Middle-Aged African American Pre- and Stage 1 Hypertensives

    Directory of Open Access Journals (Sweden)

    Sheara Williamson

    2011-01-01

    Full Text Available Endothelial dysfunction and a sedentary lifestyle may be involved in the development of hypertension which is proliferative among middle-aged African Americans (AA. Signaling molecules derived from the oxidation of 20-carbon fatty acid molecules known as eicosanoids influence vascular tone. The relationship between aerobic fitness and eicosanoid formation following exercise in middle-aged African American hypertensives is unknown. Purpose. To determine the relationship between aerobic capacity and eicosanoid formation after a bout of moderate-intensity exercise in middle-aged AA hypertensives. Methods. Ten sedentary hypertensive AA underwent 50 min of aerobic exercise at 65% VO2max. Urine was collected for 24 hr on two occasions, prior to testing and immediately following the bout of exercise. Urinary metabolites of prostacyclin (6-keto PGF1α and thromboxane (11-dTXB2 were measured during the day and night periods by high-performance liquid chromatography (HPLC. Results. 6-keto PGF1α levels significantly increased (=.04 following the bout of exercise compared to the control day. There was a significant relationship (=.49, <.05 between 6-keto PGF1α levels and VO2max during the exercise day. Conclusion. Based on this preliminary study, there appears to be a relationship between aerobic capacity and exercise-induced 6-keto PGF1α production in middle-aged hypertensive AAs. AAs with lower VO2max had lower 6-keto PGF1α formation.

  2. Oral Health Inequalities between Rural and Urban Populations of the African and Middle East Region.

    Science.gov (United States)

    Ogunbodede, E O; Kida, I A; Madjapa, H S; Amedari, M; Ehizele, A; Mutave, R; Sodipo, B; Temilola, S; Okoye, L

    2015-07-01

    Although there have been major improvements in oral health, with remarkable advances in the prevention and management of oral diseases, globally, inequalities persist between urban and rural communities. These inequalities exist in the distribution of oral health services, accessibility, utilization, treatment outcomes, oral health knowledge and practices, health insurance coverage, oral health-related quality of life, and prevalence of oral diseases, among others. People living in rural areas are likely to be poorer, be less health literate, have more caries, have fewer teeth, have no health insurance coverage, and have less money to spend on dental care than persons living in urban areas. Rural areas are often associated with lower education levels, which in turn have been found to be related to lower levels of health literacy and poor use of health care services. These factors have an impact on oral health care, service delivery, and research. Hence, unmet dental care remains one of the most urgent health care needs in these communities. We highlight some of the conceptual issues relating to urban-rural inequalities in oral health, especially in the African and Middle East Region (AMER). Actions to reduce oral health inequalities and ameliorate rural-urban disparity are necessary both within the health sector and the wider policy environment. Recommended actions include population-specific oral health promotion programs, measures aimed at increasing access to oral health services in rural areas, integration of oral health into existing primary health care services, and support for research aimed at informing policy on the social determinants of health. Concerted efforts must be made by all stakeholders (governments, health care workforce, organizations, and communities) to reduce disparities and improve oral health outcomes in underserved populations. PMID:26101336

  3. Sedimentary geochemistry of chert from the Middle-Upper Ordovician in Shihuigou area, North Qilian orogenic belt and its tectonic implication

    Institute of Scientific and Technical Information of China (English)

    DU Yuansheng; ZHU Jie; GU Songzhu

    2007-01-01

    The North Qilian orogenic belt is an elongate tectonic unit that lies between the North China plate to the north and the Middle Qilian microplate to the south, and is formed by a collision of the two plates in the Caledonian. The Shihuigou Section from Yongdeng County, Gansu Province,is in the eastern sector of the North Qilian Mountains, span-ning the Ordovician island-arc zones. The Zhongpu Group is distributed in the Shihuigou area and composed of medium-basic volcanic rocks and volcanic clastic rocks interspersed with cherts, limestones, slates, and metamorphic sandstones.The geochemistry of chert from the Zhongpu Group reveals that all cherts coexisting with island-arc volcanic rocks formed in a continental margin basin environment. Research results of the rare earth elements reveal that these cherts formed in a relatively deep-water basin with no significant terrestrial interference. Therefore, it is inferred that the North Qilian orogenic belt was previously an archipelagic ocean in the Ordovician.

  4. Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere

    Science.gov (United States)

    Wang, Chao; Ding, Lin; Zhang, Li-Yun; Kapp, Paul; Pullen, Alex; Yue, Ya-Hui

    2016-10-01

    The Gangdese belt is dominantly composed of igneous rocks that formed during the northward subduction of Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane and has played a crucial role in understanding the pre-collisional evolution of southern Tibet. This paper presents new geochronological and geochemical (whole-rock major and trace element and Sr-Nd and zircon Hf isotope) data for recently identified volcanic rocks exposed in Changguo area, southernmost part of the Lhasa terrane. Zircon U-Pb dating from six samples yields consistent ages of 237.1 ± 1.1 Ma to 211.7 ± 1.5 Ma for magma emplacement through volcanic eruption, showing the Middle-Late Triassic magmatic activity in the southernmost Gangdese Belt. The Changguo volcanic rocks are mainly composed of basaltic and andesitic rocks and exhibit LILE enrichment and HFSE depletion. They also exhibit relatively uniform Nd-Hf isotopic compositions (εNd(t) = + 5.20 to + 7.74 and εHf(t)zircon = + 10.2 to + 15.9). The basaltic magmas were likely sourced from partial melting of sub-arc mantle wedge that was metasomatized by not only the aqueous fluid derived from subducting altered oceanic crust but also hydrous melt derived from subducting seafloor sediments, and subsequently experienced fractional crystallization and juvenile crustal contamination during ascent. The andesitic magmas were generated by partial melting of mafic-ultramafic metasomes through melt/fluid-peridotite reaction at slab-mantle interface. Taking into account the temporal and spatial distribution of the Early Mesozoic magmatic rocks and regional detrital zircon data, we further propose that the northward subduction of Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane commenced by Middle Triassic.

  5. A Qualitative Study to Understand Nativity Differences in Breastfeeding Behaviors Among Middle-Class African American and African-Born Women.

    Science.gov (United States)

    Fabiyi, Camille; Peacock, Nadine; Hebert-Beirne, Jennifer; Handler, Arden

    2016-10-01

    Objective To explore nativity differences and the role of attitudes, social norms, and behavioral control perceptions surrounding breastfeeding initiation and duration among middle-class African-American (AA) and African-born (AB) mothers in the US. Methods Semi-structured individual interviews were conducted with 20 middle-class AA and AB mothers in central Ohio from December 2012 to February 2013. Interview questions were developed based on the Theory of Planned Behavior (TPB). Interviews were analyzed for salient themes by TPB constructs. Differences in themes were examined by nativity status. Results All study participants had initiated breastfeeding or bottle-feeding with expressed breast milk, noting the benefits it conferred as well as the persuasive encouragement they received from others. Persistent encouragement was often cited as a factor for sustaining breastfeeding. More AA mothers had discontinued breastfeeding by the time of the interview, which was often attributed to health, lactation, and work challenges. Inconsistent support from health providers, dissuasive remarks from others, ambivalent breastfeeding attitudes, and diminished family support led some mothers to begin formula supplementation. Analysis of maternal narratives revealed nativity differences across sources of encouragement. Specifically, important sources of encouragement were health providers for AA mothers and family, friends, partners and culture for AB mothers. Only AB mothers expressed concerns about difficulty they encountered with breastfeeding due to the lack of proximal family support. Conclusions Findings reveal that both groups of mothers may be susceptible to unsupportive breastfeeding norms in the US and also highlight the need for intervention in health care settings and workplaces to improve AA women's breastfeeding rates. PMID:27334637

  6. Zircon U-Pb ages, Hf isotope data, and tectonic implications of Early-Middle Triassic granitoids in the Ailaoshan high-grade metamorphic belt of Southeast Tibet

    Science.gov (United States)

    Wu, Wenbin; Liu, Junlai; Chen, Xiaoyu; Zhang, Lisheng

    2016-05-01

    The Ailaoshan tectonic belt, where the effects of the Paleo-Tethyan ocean evolution and Indian-Eurasian plate collision are superimposed, is one of the most significant geological discontinuities in western Yunnan province of southeast Tibet. An Ailaoshan micro-block within the belt is bounded by the Ailaoshan suture zone to the west and the Red River Fault to the east, and consists of low- and high-grade metamorphic belts. Late Permian-Middle Triassic granitoids that are widely distributed to the west of the Ailaoshan suture zone and within the Ailaoshan micro-block may yield significant information on the Tethyan tectonic evolution of the Ailaoshan tectonic belt. This study reports new LA-ICP-MS zircon U-Pb geochronology and Hf isotope data of four granitoids from the Ailaoshan high-grade metamorphic belt. Zircon grains from the Yinjie granitoid do not have inherited cores and yield a weighted mean U-Pb age of 247.1 ± 2.0 Ma. The zircon ɛ Hf(t) values range from 7.8 to 12.1, and Hf model ages from 775 to 546 Ma, indicating that the granitoid was derived from juvenile crust. The rims of zircons from the Majie and Yuanjiang granitoids yield weighted mean U-Pb ages of 239.5 ± 1.8 and 237.9 ± 2.6 Ma, respectively, whereas the cores yield ages of 1608-352 Ma. The ɛ Hf(t) values of zircon rims range from -20.4 to -5.3, yielding Hf model ages from 2557 to 1606 Ma and suggesting that the source magma of the Majie and Yuanjiang granitoids was derived from ancient crust. An additional granitoid located near the Majie Village yields a zircon U-Pb age of 241.2 ± 1.0 Ma. Based on our geochronological and geochemical data, combined with geological observations, we propose that the Ailaoshan micro-block was derived from the western margin of the Yangtze block, and is comparable to the Zhongzan and Nam Co micro-blocks. The presence of late Permian mafic rocks with rift-related geochemical characteristics within the Ailaoshan micro-block, together with granitoids derived

  7. Black Moms and “White Motherhood Society”: African-American Middle-Class Mothers’ Perspectives on Work, Family and Identity

    OpenAIRE

    Dow, Dawn

    2011-01-01

    African-American middle-class mothers have historically been structurally, culturally, and economically excluded from the practices related to hegemonic frameworks of mothering and parenting that have been described and critiqued by family and work life scholars. Collectively these frameworks make three theoretical assumptions: 1) mothers are principally responsible for raising children, 2) working outside of the home conflicts with being a mother and 3) middle-class mothers share beliefs ab...

  8. African Homo erectus: Old radiometric ages and young Oldowan assemblages in the middle Awash Valley, Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J.D.; White, T.D.; Selassie, Y.H. (Univ. of California, Berkeley, CA (United States)); Heinzelin, J. de (Institut Royal des Sciences Naturelles de Belgique, Brussels (Belgium)); Schick, K.D. (Indiana Univ., Bloomington, IN (United States)); Hart, W.K. (Miami Univ., Oxford, OH (United States)); WoldeGabriel, G. (Los Alamos National Lab., NM (United States)); Walter, R.C. (Institute of Human Origins, Berkeley, CA (United States)); Suwa, G. (Univ. of Tokyo (Japan)); Asfaw, B. (Addis Ababa (Ethiopia)) (and others)

    1994-06-24

    Fossils and artifacts recovered from the middle Awash Valley of Ethiopia's Afar depression sample the Middle Pleistocene transition from Homo erectus to Homo sapiens. Ar/Ar ages, biostratigraphy, and tephrachronology from this area indicate that the Pleistocene Bodo hominid cranium and newer specimens are approximately 0.6 million years old. Only Oldowan chopper and flake assemblages are present in the lower stratigraphic units but Acheulean bifacial artifacts are consistently prevalent and widespread in directly overlying deposits. This technological transition is related to a shift in sedimentary regime, supporting the hypothesis that Middle Pleistocene Oldowan assemblages represent a behavioral facies of the Acheulean industrial complex.

  9. Student Perceptions of Teacher Characteristics on Math Achievement for Middle School African American Students

    Science.gov (United States)

    Clayton, Otis, Jr.

    2013-01-01

    This causal-comparative research explored how African American students' perceptions of their math teachers affected their academic performance on the Math Tennessee Comprehensive Assessment Program (TCAP) Test during 2009-2010 academic year. When considering possible measures of teacher effectiveness in K-12 education, it can be argued that…

  10. Latent Patterns of Risk Behavior in Urban African-American Middle School Students in Baltimore City

    Science.gov (United States)

    Hedden, Sarra L.; Whitaker, Damiya E.; von Thomsen, Sarah; Severtson, S. Geoffrey; Latimer, William W.

    2011-01-01

    Students who engage in high-risk behaviors, including early initiation of sexual intercourse, alcohol use, marijuana use, tobacco use, and externalizing behavior are vulnerable to a broad range of adverse outcomes as adults. Latent class analysis was used to determine whether varying patterns of risk behavior existed for 212 urban African-American…

  11. Pre-collisional geodynamic context of the southern margin of the Pan-African fold belt in Cameroon

    Science.gov (United States)

    Nkoumbou, C.; Barbey, P.; Yonta-Ngouné, C.; Paquette, J. L.; Villiéras, F.

    2014-11-01

    We reassess the geodynamic context close to the Congo craton during the pre-collisional period of the Pan-African orogeny from whole-rock major and trace element compositions and isotopic data obtained in the westward extension of the Yaounde series (Boumnyebel area, Cameroon). The series consists of metasediments (micaschists, minor calc-silicate rocks and marbles) and meta-igneous rocks (hornblende gneisses, amphibolites, metagabbros, pyroxenites and talcschists) recrystallized under high-pressure conditions. Chemically, the micaschists correspond to shales and greywackes similar to the Yaounde high-grade gneisses. 87Sr/86Sr initial ratios (0.7084-0.7134), moderately negative εNd(620 Ma) values (-5.75 to -7.81), Nd model ages (1.66 chemical precipitation in relation with submarine magmatic activity. Talcschists (orthopyroxenitic to harzburgitic in composition) show primitive-mantle-normalized multi-element patterns with significant negative Nb-Ta anomalies, and slopes similar to that of average metasomatically altered lithospheric mantle. These rocks could be mantle slices involved in the collision tectonics. Amphibolites show the compositions of island-arc basalts with systematic negative Nb-Ta anomalies, 87Sr/86Sr initial ratios mostly meta-igneous rocks seem to be representative of distinct magmatic events that accompanied the evolution of the Yaounde sedimentary basin, from opening and oceanisation to convergence and closure in relation with the collisional process. These data suggest that the Yaounde basin should not be considered as a back-arc basin, but more likely represents the expression of extensional processes to the north of the Congo craton, which led to rifting, fragmentation and limited oceanisation. In this view, the Adamawa-Yade block may represent a micro-continent detached from the Congo craton during the early Neoproterozoic.

  12. Early-Middle Paleozoic subduction-collision history of the south-eastern Central Asian Orogenic Belt: Evidence from igneous and metasedimentary rocks of central Jilin Province, NE China

    Science.gov (United States)

    Pei, Fu-Ping; Zhang, Ying; Wang, Zhi-Wei; Cao, Hua-Hua; Xu, Wen-Liang; Wang, Zi-Jin; Wang, Feng; Yang, Chuan

    2016-09-01

    To constrain the Early-Middle Paleozoic tectonic evolution of the south-eastern segment of the Central Asian Orogenic Belt (CAOB), we undertook zircon U-Pb dating and analyzed major and trace elements and zircon Hf isotope compositions of Late Cambrian to Middle Devonian igneous and metasedimentary rocks in central Jilin Province, NE China. LA-ICP-MS zircon U-Pb dating indicates that the Early-Middle Paleozoic magmatism in central Jilin Province can be divided into four episodes: Late Cambrian (ca. 493 Ma), Middle Ordovician (ca. 467 Ma), Late Ordovician-Early Silurian (ca. 443 Ma), and Late Silurian-Middle Devonian (425-396 Ma). The progression from subduction initiation to maturity is recorded by Late Cambrian low-K tholeiitic meta-diabase, Middle Ordovician medium-K calc-alkaline pyroxene andesite, and Late Ordovician to Early Silurian low-K tonalite, which all have subduction-related characteristics and formed in an evolving supra-subduction zone setting. Late Silurian to Middle Devonian calc-alkaline igneous rocks, with the lithological association of granodiorite, monzogranite, rhyolite, dacite, and trachydacite, show progressively increasing K2O contents from medium K to shoshonite series. Furthermore, the Early-Middle Devonian monzogranites are characterized by high K2O, Sr/Y, and [La/Yb]N values, indicating they were generated by the melting of thickened lower crust. These results suggest a transition from subduction to post-orogenic setting during the Late Silurian-Middle Devonian. Our interpretation is supported by the maximum age of molasse deposition in the Zhangjiatun member of the Xibiehe Formation. Overall, we suggest that Late Cambrian tholeiitic meta-diabase, Middle Ordovician pyroxene andesite, and Late Ordovician-Early Silurian tonalite formed above the northward-subducting and simultaneously seaward-retreating of Paleo-Asian Ocean plate. Subsequently, the northern arc collided with the North China Craton and post-orogenic extension occurred

  13. Adakitic magmatism in post-collisional setting: An example from the Early-Middle Eocene Magmatic Belt in Southern Bulgaria and Northern Greece

    Science.gov (United States)

    Marchev, Peter; Georgiev, Stoyan; Raicheva, Raya; Peytcheva, Irena; von Quadt, Albrecht; Ovtcharova, Maria; Bonev, Nikolay

    2013-11-01

    Post-collisional (56.0-40.4 Ma) adakitic magmatism in the Rhodope Massif and the Kraishte region, including W. Srednogorie, in South Bulgaria followed the collision of the Rhodope and Pelagonian Massifs. It forms a 250 km NW trending belt which continues into the 1000 km long belt of Eocene magmatism in northern Turkey and Iran. The rocks are represented by felsic subvolcanic dykes and sills in the Kraishte and plutons in the Rhodopes. Here, we synthesize new chemical (whole-rock major and trace elements, and Sr and Nd isotopes) and LA-ICP/MS mineral and U-Pb zircon age data along with published similar data in order to constrain the genesis of this magmatism and the early Cenozoic geodynamic evolution of the central Balkan Peninsula. The rocks display typical subduction-related characteristics with enrichment in LILE and LREE and depletion in HFSE (Nb, Ta and Ti). In the Kraishte and western Srednogorie Zones these are calc-alkaline to high-K calc-alkaline rhyolites, displaying a typical adakitic signature, i.e. high La/Yb and Sr/Y ratios. The studied Rhodope Massif rocks are predominantly high-K calc-alkaline and subordinate calc-alkaline granites and granodiorites with a minor amount of tonalites. Petrographically, they are H2O- and accessory-rich (allanite, epidote, titanite, apatite) rocks, showing geochemical affinities from non-adakitic tonalites and mafic granodiorites to adakitic granodiorites and granites. Similarity of Sr and Nd isotopic compositions of the Kraishte subvolcanic and Rhodope intrusive adakitic rocks with the neighboring and coeval NW Anatolian basaltic to dacitic volcanics and plutons suggests that the most likely source for the South Bulgarian adakitic rocks is the subduction-enriched depleted lithospheric mantle. The nearby and contemporaneous East Serbian alkaline basalts are isotopically and compositionally different and, probably, originate from an OIB-like mantle source. Subsequent fractionation within an isotopically similar lower

  14. Virtual industrial water usage and wastewater generation in the Middle East/North African region

    OpenAIRE

    S. R. Sakhel; Geissen, S.-U.; A. Vogelpohl

    2013-01-01

    This study deals with the quantification of volumes of water usage, wastewater generation, virtual water export, and wastewater generation from export for eight export relevant industries present in the Middle East/North Africa (MENA). It shows that about 3400 million m3 of water is used per annum while around 793 million m3 of wastewater is generated from products that are meant for domestic consumption and export. The difference between volumes of water usage and ...

  15. Geochemistry and Nd Sr isotopic studies of Late Mesozoic granitoids in the southeastern Hubei Province, Middle Lower Yangtze River belt, Eastern China: Petrogenesis and tectonic setting

    Science.gov (United States)

    Xie, Guiqing; Mao, Jingwen; Li, Ruiling; Bierlein, Frank P.

    2008-08-01

    A geochemical and isotopic study was carried out for the Mesozoic Yangxin, Tieshan and Echeng granitoid batholiths in the southeastern Hubei Province, eastern China, in order to constrain their petrogenesis and tectonic setting. These granitoids dominantly consist of quartz diorite, monzonite and granite. They are characterized by SiO 2 and Na 2O compositions of between 54.6 and 76.6 wt.%, and 2.9 to 5.6 wt.%, respectively, enrichment in light rare earth elements (LREE) and large ion lithophile elements (LILE), and relative depletion in Y (concentrations ranging from 5.17 to 29.3 ppm) and Yb (0.34-2.83 ppm), with the majority of the granitoids being geochemically similar to high-SiO 2 adakites (HSA). Their initial Nd ( ɛNd = - 12.5 to - 6.1) and Sr (( 87Sr/ 86Sr) i = 0.7054-0.7085) isotopic compositions, however, distinguish them from adakites produced by partial melting of subducted slab and those produced by partial melting of the lower crust of the Yangtze Craton in the Late Mesozoic. The granitoid batholiths in the southeastern Hubei Province exhibit very low MgO ranging from 0.09 to 2.19 wt.% with an average of 0.96 wt.%, and large variations in negative to positive Eu anomalies (Eu/Eu * = 0.22-1.4), especially the Tieshan granites and Yangxin granite porphyry (Eu/Eu * = 0.22-0.73). Geochemical and Nd-Sr isotopic data demonstrate that these granitoids originated as partial melts of an enriched mantle source that experienced significant contamination of lower crust materials and fractional crystallization during magma ascent. Late Mesozoic granitoids in the southeastern Hubei Province of the Middle-Lower Yangtze River belt were dominantly emplaced in an extensional tectonic regime, in response to basaltic underplating, which was followed by lithospheric thinning during the early Cretaceous.

  16. Geological Fluid Mapping in the Tongling Area: Implications for the Paleozoic Submarine Hydrothermal System in the Middle-Lower Yangtze Metallogenic Belt, East China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Tongling area is one of the 7 ore-cluster areas in the Middle-Lower Yangtze metallogenic belt, East China, and has tectonically undergone a long-term geologic history from the late Paleozoic continental rifting, through the Middle Triassic continent-continent collision to the Jurassic-Cretaceous intracontinental tectono-magmatic activation. The Carboniferous sedimentary-exhalative processes in the area produced widespread massive sulfides with ages of 303-321 Ma, which partly formed massive pyrite-Cu deposits, but mostly provided significant sulfur and metals to the skarn Cu mineralization associated with the Yanshanian felsic intrusions.To understand the Carboniferous submarine hydrothermal system, an area of about 1046 km2 was chosen to carry out the geological fluid mapping. Associated with massive sulfide formation, footwall sequences 948 m to 1146 m thick, composed of the Lower Silurian-Upper Devonian sandstone, siltstone and thin-layered shale, were widely altered. This hydrothermal alteration is interpreted to reflect largescale hydrothermal fluid flow associated with the late Paleozoic crustal rifting and subsidence. Three hydrothermal alteration types, i.e., deep-level semiconformable silicification (S1), fracture-controlled quartz-sericite-pyrite alteration (S2-3), and upper-level sub-discordant quartz-sericite-chlorite alteration (D3), were developed to form distinct zones in the mapped area. About 50-m thick semiconformable siliclfication zones are located at ~1-km depth below massive sulfides and developed between an impermeable shale caprock (S1) and the underlying Ordovician unaltered limestone.Comparisons with modern geothermal systems suggest that the alteration zones record a sub-seafloor aquifer with the most productive hydrothermal fluid flow. Fracture-controlled quartz-sericite-pyrite alteration formed transgressive zones, which downward crosscut the semiconformable alteration zones,and upwards grade into sub-discordant alteration zones

  17. Geological, geochronological, and mineralogical constraints on the genesis of the Chengchao skarn Fe deposit, Edong ore district, Middle-Lower Yangtze River Valley metallogenic belt, eastern China

    Science.gov (United States)

    Yao, Lei; Xie, Guiqing; Mao, Jingwen; Lü, Zhicheng; Zhao, Caisheng; Zheng, Xianwei; Ding, Ning

    2015-04-01

    The Edong ore district is located within the westernmost Middle-Lower Yangtze River Valley metallogenic belt (MLYRB), and hosts the largest concentration of skarn Fe deposits in China, although the origin of these deposits remains controversial. The Chengchao deposit is the largest skarn Fe deposit so far discovered within the MLYRB, and provides a good opportunity to address the debate surrounding the origin of these skarn Fe deposits. Here, we present geological, geochronological, and mineralogical data from the Chengchao skarn deposit and associated intrusions, and discuss the relationships between granitoids and mineralization in the Chengchao deposit. The NW-SE-striking orebodies in the study area have porphyritic quartz monzonite and/or granite footwalls, and Triassic marble or diorite hangingwalls, indicating a spatial relationship between these intrusions and Fe mineralization. Zircon U-Pb data from the granite, porphyritic quartz monzonite, diorite, and porphyritic diabase dike within the deposit show ages of 129 ± 1, 128 ± 1, 140 ± 1, and 126 ± 1 Ma, respectively. These ages and the previously reported ages on the timing of mineralization suggest that the porphyritic quartz monzonite and granite are coeval with the formation of the skarn Fe deposit. Our data confirm that the granitic rocks are temporally associated with Fe mineralization. The prograde substage of skarn development is characterized by two stages of andradite (Adr98-38Grs61-2Prp2-0Sps1-0Alm1-0) and diopside (Di95-61Hd37-5Jo3-0), including an early stage of garnet and pyroxene formation that is genetically associated with the mineralization. The early stage garnets are more andradite-rich (Adr98-50Grs49-2Prp1-0Sps1-0Alm0) than the late veinlet garnets characterized by intermediate grandite compositions (Adr67-37Grs61-31Prp2-0Sps1-0Alm1-0). The early stage pyroxenes (Di95-74Hd26-5Jo1-0) are compositionally distinct from the late stage pyroxenes (Di84-61Hd37-16Jo3-0). Compositional

  18. Middle east and North African oil in international relations (from 1970 to these days)

    International Nuclear Information System (INIS)

    Petroleum is not purely an economical product, its main role in world economy and its concentration in Middle East and North Africa (two third of world reserves) made influence international politics. Knowing the nature of the region, petroleum and politics make one. The politicization of oil in the region starts, first of all, with the efforts of some powers, through their companies, to dominate oil countries, which by reaction incite these countries to eliminate foreign domination and establish their national control on oil matters. The situation is changing progressively. The position of productive states got stronger with the beginning of the 1970's which permitted the use of oil, in a way relatively efficient, as an instrument of power. Consequently, the balance of power shifted deeply in the favor of producers. On this basis, the argument consists of three parts: the first puts theoretic bases - theory of economical arm - and defines geographical and historical environment of the research. The second part studies the period of force of the oil countries, from the fourth Israel-Arab war and oil embargo that followed it, to the end of the second oil slump. The third part explains the shift of power on the international scene and the relative decline of oil power for the states of the region. The analysis of impact of the oil slump in 1986 and the mini impact of the second Persian Gulf war, quickly dominated, lead to clear the actual situation and outline the viewpoint of the future. (author)

  19. Virtual industrial water usage and wastewater generation in the Middle East/North African region

    Science.gov (United States)

    Sakhel, S. R.; Geissen, S.-U.; Vogelpohl, A.

    2013-01-01

    This study deals with the quantification of volumes of water usage, wastewater generation, virtual water export, and wastewater generation from export for eight export relevant industries present in the Middle East/North Africa (MENA). It shows that about 3400 million m3 of water is used per annum while around 793 million m3 of wastewater is generated from products that are meant for domestic consumption and export. The difference between volumes of water usage and wastewater generation is due to water evaporation or injecting underground (oil wells pressure maintenance). The wastewater volume generated from production represents a population equivalent of 15.5 million in terms of wastewater quantity and 30.4 million in terms of BOD. About 409 million m3 of virtual water flows from MENA to EU27 (resulting from export of eight commodities) which is equivalent to 12.1% of the water usage of those industries and Libya is the largest virtual water exporter (about 87 million m3). Crude oil and refined petroleum products represent about 89% of the total virtual water flow, fertilizers represent around 10% and 1% remaining industries. EU27 poses the greatest indirect pressure on the Kuwaiti hydrological system where the virtual water export represents about 96% of the actual renewable water resources in this country. The Kuwaiti crude oil water use in relation to domestic water withdrawal is about 89% which is highest among MENA countries. Pollution of water bodies, in terms of BOD, due to production is very relevant for crude oil, slaughterhouses, refineries, olive oil, and tanneries while pollution due to export to EU27 is most relevant for crude oil industry and olive oil mills.

  20. Virtual industrial water usage and wastewater generation in the Middle East/North African region

    Directory of Open Access Journals (Sweden)

    S. R. Sakhel

    2013-01-01

    Full Text Available This study deals with the quantification of volumes of water usage, wastewater generation, virtual water export, and wastewater generation from export for eight export relevant industries present in the Middle East/North Africa (MENA. It shows that about 3400 million m3 of water is used per annum while around 793 million m3 of wastewater is generated from products that are meant for domestic consumption and export. The difference between volumes of water usage and wastewater generation is due to water evaporation or injecting underground (oil wells pressure maintenance. The wastewater volume generated from production represents a population equivalent of 15.5 million in terms of wastewater quantity and 30.4 million in terms of BOD. About 409 million m3 of virtual water flows from MENA to EU27 (resulting from export of eight commodities which is equivalent to 12.1% of the water usage of those industries and Libya is the largest virtual water exporter (about 87 million m3. Crude oil and refined petroleum products represent about 89% of the total virtual water flow, fertilizers represent around 10% and 1% remaining industries. EU27 poses the greatest indirect pressure on the Kuwaiti hydrological system where the virtual water export represents about 96% of the actual renewable water resources in this country. The Kuwaiti crude oil water use in relation to domestic water withdrawal is about 89% which is highest among MENA countries. Pollution of water bodies, in terms of BOD, due to production is very relevant for crude oil, slaughterhouses, refineries, olive oil, and tanneries while pollution due to export to EU27 is most relevant for crude oil industry and olive oil mills.

  1. The karyotype of the middle-African hedgehog Atelerix albiventris Wagner, 1841 and its cytotaxonomical relationships to other Erinaceinae (Insectivora: Erinaceidae).

    Science.gov (United States)

    Hübner, R; Maddalena, T; Poduschka, W

    1991-01-01

    Like other hedgehog species investigated hitherto, also the Middle African species Atelerix albiventris has a diploid number of 48 chromosomes. However, Aethechinus and Atelerix display quite distinct cytogenetic characteristics compared to the hedgehog genera Erinaceus, Hemiechinus and Paraechinus. Individual chromosome structures and reactivities permit the recognition of similarities to the Algerian hedgehog Aethechinus algirus and indicate their close relationship. Nevertheless, the proposal by Corbet (1988) to merge the two taxa into one genus, which is contrary to Robbins and Setzer (1985) remains to be clarified by further investigations. PMID:1879689

  2. Structural setting of the Apennine-Maghrebian thrust belt

    Institute of Scientific and Technical Information of China (English)

    PieroElter; MarioGrasso; MaurizioParotto; LivioVezzani

    2003-01-01

    The Apennine-Maghrebian fold-and-thrust belt devel-oped from the latest Cretaceous to Early Pleistocene at the subduction-collisional boundary between the Euro-pean and the westward-subducted Ionian and Adria plates. Large parts of the Mesozoic oceanic lithosphere were subducted during an Alpine phase from the Late Cretaceous to Middle Eocene. The chain developed through the deformation of major paleogeographic internal domains (tectono-sedimentary sequences of the Ligurian-Piedmont Ocean) and external domains (sedi-mentary sequences derived from the deformation of the continental Adria-African passive mareinL The continu-ity of the Apennine chain is abruptly interrupted in the Calabrian Arc by the extensive klippe of Kabylo-Calabrian crystalline exotic terranes, derived from deformation of the European passive margin.Major complexities (sharp deflections in the arcuate configuration of the thrust belt, out-of-sequence propagation of the thrusts) are referred to contrasting rheology and differential buoyancy of the subducted lithosphere (transitional from conti-nental to oceanic) and consequent differential roll-back of the Adria plate margin, and to competence contrasts in the Mesozoic stratigraphic sequences,where multiple décollement horizons at different stratigraphic levels may have favored significant differential shortening.From the Late Miocene, the geometry of the thrust belt was strongly modified by extensional fault-ing, volcanic activity, crustal thinning and formation of oceanic crust correlated with the development of the Tyrrhenian Basin.

  3. Geology and geochemistry of the Middle Proterozoic Eastern Ghat mobile belt and its comparison with the lower crust of the Southern Peninsular shield

    Science.gov (United States)

    Rao, M. V. Subba

    1988-01-01

    Two prominent rock suites constitute the lithology of the Eastern Ghat mobile belt: (1) the khondalite suite - the metapelites, and (2) the charnockite suite. Later intrusives include ultramafic sequences, anorthosites and granitic gneisses. The chief structural element in the rocks of the Eastern Ghats is a planar fabric (gneissosity), defined by the alignment of platy minerals like flattened quartz, garnet, sillimanite, graphite, etc. The parallelism between the foliation and the lithological layering is related to isoclinal folding. The major structural trend (axial plane foliation trend) observed in the belt is NE-SW. Five major tectonic events have been delineated in the belt. A boundary fault along the western margin of the Eastern Ghats, bordering the low grade terrain has been substantiated by recent gravity and the deep seismic sounding studies. Field evidence shows that the pyroxene granulites (basic granulites) post-date the khondalite suite, but are older than the charnockites as well as the granitic gneisses. Polyphase metamorphism, probably correlatable with different periods of deformation is recorded. The field relations in the Eastern Ghats point to the intense deformation of the terrain, apparently both before, during and after metamorphism.

  4. Self-reported Experiences of Discrimination and Visceral Fat in Middle-aged African-American and Caucasian Women

    OpenAIRE

    Lewis, Tené T.; Kravitz, Howard M.; Janssen, Imke; Powell, Lynda H.

    2011-01-01

    The authors examined the association between self-reported experiences of discrimination and subtypes of abdominal fat (visceral, subcutaneous) in a population-based cohort of African-American and Caucasian women. Prior studies examining associations between discrimination and abdominal fat have yielded mixed results. A major limitation of this research has been the reliance on waist circumference, which may be a poor marker of visceral fat, particularly for African-American women. Participan...

  5. The Attitudes of African American Middle School Girls Toward Computer Science: Influences of Home, School, and Technology Use

    OpenAIRE

    Robinson, Ashley Renee

    2015-01-01

    The number of women in computing is significantly low compared to the number of men in the discipline, with African American women making up an even smaller segment of this population. Related literature accredits this phenomenon to multiple sources, including background, stereotypes, discrimination, self-confidence, and a lack of self-efficacy or belief in one's capabilities. However, a majority of the literature fails to represent African American females in research studies. This r...

  6. “一带一路”战略视域下的中非天然气合作%Sino-African Natural Gas Cooperation in the Context of One Belt and One Road Strategy

    Institute of Scientific and Technical Information of China (English)

    王涛; 曹峰毓

    2015-01-01

    当前,天然气合作已成为中非合作新的重要领域。通过梳理和分析中非间天然气贸易与投资情况、中国能源进口形势、国际油气市场态势等领域的数据和文献,笔者认为,通过加强非洲天然气供应地保障、促进中非天然气贸易、提升对非天然气投资水平、鼓励中非天然气领域的经验与智力交流等手段,可以极大地拓展我国“一带一路”战略实施的广度与深度。要实现这一目标,需要我国油气企业充分把握国际能源格局转型、中国能源企业国际化、中非能源合作升温以及“一带一路”战略配套政策等带来的机遇,进一步深化中非间天然气合作力度。当然,在这一过程中,我国油气企业必须妥善应对不利的投资环境、严峻的安全局势与外部竞争形势带来的各种挑战。%At present,natural gas cooperation between China and African countries has become an important part of Sino-African cooperation. Through extensive analysis of the data and literatures about Sino-African natural gas trade and investment, the situation of China’s energy import and the trend of the international oil and gas market,this article reveals that in order to largely broaden and deepen the practice of One Belt and One Road Strategy,China should guarantee natural gas supply in Africa,promote Sino-Africa natural gas trade and natural gas investment in Africa and encourage communication of experiences and technologies of natural gas development between China and Africa. Therefore,Chinese government should seize the opportunities brought by the transformation of world energy landscape,the internationalization of Chinese energy companies, the increasingly close Sino-African energy cooperation and the support of One Belt and One Road Strategy to further strengthen Sino-African natural gas cooperation. However,the unfavorable investment environment,the severe security situation in Africa and the

  7. The Identity Status of African Americans in Middle Adolescence: A Replication and Extension of Forbes and Ashton (1998).

    Science.gov (United States)

    Branch, Curtis W.; Boothe, Barrington

    2002-01-01

    This study is a replication and extension of the work of Forbes and Ashton (1998). Seventy-seven African American high school students completed the revised version of the Extended Objective Measure of Ego Identity Status. Most of the students were found to be in uncommitted identity statuses. Similar results were found in both ideological and…

  8. Longitudinal Effects of Family Factors on Alcohol Use among African American and White Non-Hispanic Males during Middle School

    Science.gov (United States)

    Horton, E. Gail; Gil, Andres

    2008-01-01

    This study examined the longitudinal effects of five family factors (familism, parent derogation, parent-child communication, family alcohol problems, and family drug problems) on intensity of alcohol use among a sample of 451 African American and White non-Hispanic males from early to mid-adolescence (sixth through eighth grades). Results…

  9. Perceptions of Parenting Practices as Predictors of Aggression in a Low-Income, Urban, Predominately African American Middle School Sample

    Science.gov (United States)

    Murray, Kantahyanee W.; Haynie, Denise L.; Howard, Donna E.; Cheng, Tina L.; Simons-Morton, Bruce

    2010-01-01

    This research examined the relation between early adolescent aggression and parenting practices in an urban, predominately African American sample. Sixth graders (N = 209) completed questionnaires about their overt and relational aggressive behaviors and perceptions of caregivers' parenting practices. Findings indicated that moderate levels of…

  10. The Relationship between Body Size and Depressed Mood: Findings from a Sample of African American Middle School Girls

    Science.gov (United States)

    Granberg, Ellen M.; Simons, Ronald L.; Gibbons, Frederick X.; Melby, Janet Nieuwsma

    2008-01-01

    The relationship between body weight and depression among adolescent females has been the subject of considerable attention from researchers. The risk of experiencing this distress, however, is not equally distributed across members of all racial groups. African American girls are generally more satisfied with their bodies and thus may be less…

  11. Media influence on pre-middle school African Americans' perceptions toward science, mathematics, and technology courses and careers

    Science.gov (United States)

    Waters, Sharon Campbell

    2005-07-01

    A variety of previous studies have suggested that inaccurate, stereotypical or missing media depictions of science, engineering, and technology (SET) workers and fields have contributed to a growing shortage of youth interested in pursuing careers within the scientific endeavor. However, studies on the perceptions of African American youth have not usually been the focus of such research. In this exploratory study, in-depth interviews were conducted with 34 fifth grade African American students to determine the relative influence television and film portrayals of SET workers had on these children's perceptions of roles in SET fields and careers and school coursework related to them. Framed within the theoretical perspectives of cultivation analysis and the construction of social reality, results indicated the majority of participants perceived scientists as ambiguous, possessing either mythic characteristics of the fantastic persona or they saw them as altruistically inclined figures that saved the world from disease, destruction, and decay. Television and film portrayals of SET workers were found in varying degrees and ways to shape these African American children's perceptions toward SET careers. While children exhibited self-concepts about SET workers that were sometimes idealistic, distorted, or unrealistic, most had favorable perceptions toward math and science courses in school. However, it was the absence of television and film portrayals of African Americans in SET roles that was problematic for the majority of students. Recommendations for media producers, educators, scientific research foundations, and parents were suggested to dispel some of these commonly found media stereotypes of SET workers and African Americans in these roles and their effects.

  12. Quantification of climate and vegetation from Southern African Middle Stone Age sites - an application using Late Pleistocene plant material from Sibudu, South Africa

    Science.gov (United States)

    Bruch, A. A.; Sievers, C.; Wadley, L.

    2012-04-01

    The isolated geographical situation of South Africa makes the unraveling of various parameters that influence its regional climate in time challenging. If the South African climate does not exhibit a linear correlation with global archives as suggested by some authors then the contribution of independent local data that provides direct information on the environment at a certain place and time is crucial. Fossil plant remains provide valuable information on past environmental conditions. Although few paleobotanical data are available from Southern Africa, some sites reveal rich and diverse fossil floras, most notably, Sibudu Cave, KwaZulu-Natal, South Africa, with its numerous fruits, seeds, pollen and charcoal flora. Such plant remains not only provide information on past vegetation, but also serve as a sound base for paleoclimate quantification with the Coexistence Approach (CA). Sibudu Cave has pulses of Middle Stone Age occupation separated by hiatuses that are as long as 10 ka. Pre-Still Bay, Still Bay, Howiesons Poort, post-Howiesons Poort and late and final Middle Stone Age industries are present. Variations in vegetation and the animals preyed on through time suggest that subtle environmental changes could have occurred during MIS4 and MIS3 in the Sibudu area. Whilst always semi-forested, the region may have comprised a mosaic of uneven and changeable patches of coastal forest and savanna. These in turn might have influenced the numbers of forest versus plains animals in the area. Cultural factors could also have played a part in the faunal variability observed in Sibudu. Preliminary analyses of Sibudu Cave material confirm the potential of the CA for its application on Late Pleistocene African floras. In the future, comparison with other contemporaneous sites will help quantify spatial differences in the climate of the Late Pleistocene in South Africa, and may answer if environmental changes effected the cultural development from Still Bay to late MSA

  13. Science self-efficacy of African American middle school students: Relationship to motivation self-beliefs, achievement, gender, and gender orientation

    Science.gov (United States)

    Britner, Shari Lynn

    Motivation researchers have established that students' self-efficacy beliefs, the confidence they have in their academic capabilities, are related to academic outcomes. Self-efficacy has been amply researched in mathematics and language arts and nearly exclusively with White students. African American students and the area of science have each received scant attention. Typically, gender differences favor boys in mathematics and girls in language arts. Researchers have also found that these differences may be a function of gender orientation beliefs. The purpose of this study was to extend findings in science self-efficacy and to African American middle school students. I sought to determine whether self-efficacy assessed at differing levels of specificity (lab skills versus science grades) would each predict science achievement assessed at corresponding levels, to discover whether mean scores in academic motivation and achievement would differ by gender, and to determine whether these differences are a function of gender orientation (N = 268). Science grade self-efficacy was positively associated with the grades obtained by boys and by girls. For girls, grades were also associated positively with science self-concept and negatively with value of science. For reasons resulting from problematic instructional practices, lab skills self-efficacy was not associated with lab grades. Girls reported stronger science self-efficacy and received higher grades in science class. Gender orientation beliefs did not account for these differences, but masculinity and femininity were each associated with science grade self-efficacy, suggesting that androgyny is an adaptive orientation for the science self-efficacy beliefs of African American students. Findings are interpreted within the framework of A. Bandura's (1986) social cognitive theory.

  14. Perceptions of Parenting Practices as Predictors of Aggression in a Low-Income, Urban, Predominately African American Middle School Sample

    OpenAIRE

    Murray, Kantahyanee W.; Haynie, Denise L.; Howard, Donna E.; Tina L. Cheng; SIMONS-MORTON, BRUCE

    2010-01-01

    This research examined the relation between early adolescent aggression and parenting practices in an urban, predominately African American sample. Sixth graders (N = 209) completed questionnaires about their overt and relational aggressive behaviors and perceptions of caregivers’ parenting practices. Findings indicated that moderate levels of parental expectations for peaceful solutions at Time 1 were associated with a lower likelihood of overt aggression at Time 2. Furthermore, findings sug...

  15. BRCA Genetic Screening in Middle Eastern and North African: Mutational Spectrum and Founder BRCA1 Mutation (c.798_799delTT in North African

    Directory of Open Access Journals (Sweden)

    Abdelilah Laraqui

    2015-01-01

    Full Text Available Background. The contribution of BRCA1 mutations to both hereditary and sporadic breast and ovarian cancer (HBOC has not yet been thoroughly investigated in MENA. Methods. To establish the knowledge about BRCA1 mutations and their correlation with the clinical aspect in diagnosed cases of HBOC in MENA populations. A systematic review of studies examining BRCA1 in BC women in Cyprus, Jordan, Egypt, Lebanon, Morocco, Algeria, and Tunisia was conducted. Results. Thirteen relevant references were identified, including ten studies which performed DNA sequencing of all BRCA1 exons. For the latter, 31 mutations were detected in 57 of the 547 patients ascertained. Familial history of BC was present in 388 (71% patients, of whom 50 were mutation carriers. c.798_799delTT was identified in 11 North African families, accounting for 22% of total identified BRCA1 mutations, suggesting a founder allele. A broad spectrum of other mutations including c.68_69delAG, c.181T>G, c.5095C>T, and c.5266dupC, as well as sequence of unclassified variants and polymorphisms, was also detected. Conclusion. The knowledge of genetic structure of BRCA1 in MENA should contribute to the assessment of the necessity of preventive programs for mutation carriers and clinical management. The high prevalence of BC and the presence of frequent mutations of the BRCA1 gene emphasize the need for improving screening programs and individual testing/counseling.

  16. 中国东北~500Ma泛非期孔兹岩带的确定及其意义%Confirming of the Heilongjiang-500Ma Pan-African khondalite belt and its tectonic implications

    Institute of Scientific and Technical Information of China (English)

    周建波; 张兴洲; Simon A WILDE; 郑常青

    2011-01-01

    东北地区的变质基底,如佳木斯地块的麻山群、兴安地块的兴华渡口群等岩石组合是以(含石墨)大理岩、夕线石榴片麻岩、斜长角闪岩等为主要标志的孔兹岩系.在额尔古纳、兴安和佳木斯-兴凯地块的夕线石榴片麻岩分别得到锆石U-Pb 年铃,证明这些高级变质岩的原岩年龄以新元古代(600~850Ma)为主,变质年龄为~500Ma,因此东北地区的变质基底记录了从Rodinia到Gondwana大陆的聚合与离散的过程.泛非期高级变质岩及其同期岩浆岩在额尔古纳、兴安、松辽、佳木斯和兴凯地块等断续分布,总体出露范围>1300km,并沿虎头、鸡西、萝北、兴华渡口和漠河一线总体北西向沿黑龙江断续分布,因此我们命名为"中国东北泛非期孔兹岩带"."中国东北泛非期孔兹岩带"的提出和进一步研究,对深入探讨东北地区各地块基底组成的异同性以及陆块聚合的过程,以及东北地区的构造演化历史及其在Gondwana大陆重建中的位!都具有重要的科学意义.%The basement rocks in NE China, including Mushan Croup in Jiamusi Block, Xinghuadukou Group in the Xing' an Block, constitute a khondalitic sequence of sillimanite- and garnet-bearing gneisses, homblende-plagioclase gneiss and felsic paragneisses. Zircon U-Pb dating of the garnet-sillimanite gneiss samples from Erguna, Xing' an and Khanka blocks indicates high-grade metamorphism occurred at ~500Ma, where several detrital zircon grains whose ages extend between 600Ma to 850Ma The Pan-African high-grade metamorphism with magmatism events were obtained from all the blocks in NE China, including the Erguna, Xing' an, Songliao and Jiamusi-Khanka blocks, establish a over 1300km Pan-African khondalite belt in NE China, named here the ' Northeast China Khondalite Belt'. The results from this study provide new idea for researching the tectonic affinity and plate evolution in the NE China.

  17. Physical activity among African American and Latino middle school girls: consistent beliefs, expectations, and experiences across two sites.

    Science.gov (United States)

    Taylor, W C; Yancey, A K; Leslie, J; Murray, N G; Cummings, S S; Sharkey, S A; Wert, C; James, J; Miles, O; McCarthy, W J

    1999-01-01

    Physical inactivity is a major public health concern. Low levels of physical activity are reported in many subgroups of women including adolescent girls. More data are needed to better understand factors related to physical activity participation in adolescent girls. Therefore, we explored adolescent girls' reasons for participating and not participating in physical activity. Two independent samples were taken in California and Texas; the total sample included thirty-four African American and Latino girls. Six focus groups were conducted by trained facilitators. Based on independent qualitative analyses, six replicated themes emerged from the focus groups. Fun, social support, and concern with body image facilitated participation in activity. In contrast, negative experiences in physical education classes, concerns about appearance after activity, and lack of opportunity impeded participation in activity. Overall, the girls showed an interest in physical activity and identified activity motivators and barriers. We discuss the implications of our findings for future research.

  18. Neighborhood conditions, diabetes, and risk of lower-body functional limitations among middle-aged African Americans: A cohort study

    Directory of Open Access Journals (Sweden)

    Yan Yan

    2010-05-01

    Full Text Available Abstract Background The relationship between presence of diabetes and adverse neighborhood and housing conditions and their effect on functional decline is unclear. We examined the association of adverse neighborhood (block face and housing conditions with incidence of lower-body functional limitations among persons with and those without diabetes using a prospective population-based cohort study of 563 African Americans 49-65 years of age at their 2000-2001 baseline interviews. Methods Participants were randomly sampled African Americans living in the St. Louis area (response rate: 76%. Physician-diagnosed diabetes was self reported at baseline interview. Lower-body functional limitations were self reported based on the Nagi physical performance scale at baseline and the three-year follow-up interviews. The external appearance of the block the respondent lived on and five housing conditions were rated by study interviewers. All analyses were done using propensity score methods to control for confounders. Results 109 (19.4% of subjects experienced incident lower-body functional limitations at three-year follow-up. In adjusted analysis, persons with diabetes who lived on block faces rated as fair-poor on each of the five conditions had higher odds (7.79 [95% confidence interval: 1.36-37.55] to 144.6 [95% confidence interval: 4.45-775.53] of developing lower-body functional limitations than the referent group of persons without diabetes who lived on block faces rated as good-excellent. At least 80 percent of incident lower-body functional limitations was attributable to the interaction between block face conditions and diabetes status. Conclusions Adverse neighborhood conditions appear to exacerbate the detrimental effects on lower-body functioning associated with diabetes.

  19. Mediterranean proto-sapropels in the Middle Miocene: implications for the strength of the African monsoon and link to Miocene glaciations

    Science.gov (United States)

    John, C. M.; Mutti, M.; Adatte, T.; Laskar, J.

    2003-04-01

    The strength of the African monsoon is known to have played a major role in determining sedimentation patterns in the Mediterranean during the Plio-Pleistocene. Increased meteoric water input by strong monsoons reduced surface water salinity, and the resulting slower water-mixing rate triggered the deposition of organic-rich layers called "sapropels". Here we present some proxy data coming from a mixed siliciclastic-carbonate section outcropping on the Maltese Islands that suggests that sapropels deposits already existed in the Middle Miocene. This implies that an enhanced monsoonal climate was likely active at that time. Our primary evidences for the existence of "proto-sapropels" are runoff proxies (clay mineral assemblages and abundance) coupled with oxygen isotopes. These indicate that a direct link existed between increased runoff regarded here as a proxy for the strength of the Monsoon- and Miocene global climate (Antarctic glaciation). Each Miocene phase of glaciation is reflected in the section as an increased flux of continental-derived material. Moreover, stable isotopes of carbon and Corg:Norg ratio analyses of organic matter revealed a higher mixing rate of terrigenous and marine organic matters during times of increased sedimentation. This is in good agreement with a monsoon model where increased sedimentation is linked to increased continental runoff. Spectral analysis of the section revealed the presence of Milankovitch-scaled cycles with a strong 100 k.y. frequency. Astronomically calibrated age model for the section shows that the African monsoon has probably initiated around 16.7 Ma and underwent a major strengthening around 13.8 Ma, a time corresponding to enhanced siliciclastic deposition on the Malta-Ragusa platform and to the global cooling phase of the Mi3 Antarctic ice-buildup phase. We argue that the strong coherence between Miocene glaciation phases and increased runoff into the Mediterranean is due to a link between Antarctic cooling

  20. Belt attachment and system

    Science.gov (United States)

    Schneider, Abraham D.; Davidson, Erick M.

    2016-02-02

    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  1. The middle Holocene climatic records from Arabia: Reassessing lacustrine environments, shift of ITCZ in Arabian Sea, and impacts of the southwest Indian and African monsoons

    Science.gov (United States)

    Enzel, Yehouda; Kushnir, Yochanan; Quade, Jay

    2015-06-01

    A dramatic increase in regional summer rainfall amount has been proposed for the Arabian Peninsula during the middle Holocene (ca. 9-5 ka BP) based on lacustrine sediments, inferred lake levels, speleothems, and pollen. This rainfall increase is considered primarily the result of an intensified Indian summer monsoon as part of the insolation-driven, northward shift of the boreal summer position of the Inter-Tropical Convergence Zone (ITCZ) to over the deserts of North Africa, Arabia, and northwest India. We examine the basis for the proposed drastic climate change in Arabia and the shifts in the summer monsoon rains, by reviewing paleohydrologic lacustrine records from Arabia. We evaluate and reinterpret individual lake-basin status regarding their lacustrine-like deposits, physiography, shorelines, fauna and flora, and conclude that these basins were not occupied by lakes, but by shallow marsh environments. Rainfall increase required to support such restricted wetlands is much smaller than needed to form and maintain highly evaporating lakes and we suggest that rainfall changes occurred primarily at the elevated edges of southwestern, southern, and southeastern Arabian Peninsula. These relatively small changes in rainfall amounts and local are also supported by pollen and speleothems from the region. The changes do not require a northward shift of the Northern Hemisphere summer ITCZ and intensification of the Indian monsoon rainfall. We propose that (a) latitudinal and slight inland expansion of the North African summer monsoon rains across the Red Sea, and (b) uplifted moist air of this monsoon to southwestern Arabia highlands, rather than rains associated with intensification of Indian summer monsoon, as proposed before, increased rains in that region; these African monsoon rains produced the modest paleo-wetlands in downstream hyperarid basins. Furthermore, we postulate that as in present-day, the ITCZ in the Indian Ocean remained at or near the equator all

  2. The Middle Neoproterozoic Sidi Flah Group (Anti-Atlas, Morocco): synrift deposition in a Pan-African continent/ocean transition zone

    Science.gov (United States)

    Fekkak, A.; Pouclet, A.; Benharref, M.

    2003-08-01

    The Middle Neoproterozoic (Cryogenian) Sidi Flah Group rocks are located in the Saghro inlier of the Eastern Anti-Atlas and consists of siliciclastic detrital sediment, interbedded basaltic lavas and small ultramafic bodies. Sediment deposition occurred in three turbiditic formations of a deep-sea fan environment and was controlled by synsedimentary collapses. The composition of sandstones and typological study of zircons indicate that detrital material came from the gneisses and granites of a proximal craton. The lavas are synsedimentary subaqueous flows. They show chemical signatures of initial rift tholeiites and of plume-related alkaline intraplate basalts. The ultramafic rocks are serpentinized peridotites that were emplaced along N160° synsedimentary faults as numerous bodies 20-50 m in size. Their petrographical (Cr-spinel signature) and chemical features correspond to intracontinental ultramafic cumulates. The emplacement of the ultramafic rocks was associated with hydrothermal activity that generated calcareous and siliceous rocks such as ophicalcites and jaspers. All the features of the sediments, the lavas and the ultramafic bodies strongly suggest a continent-ocean transition geotectonic context, in an advanced stage of continental rifting that we attribute to the pre-Pan-African ocean passive margin extension.

  3. Comparison of the reorganisations of BP and Shell and possible opportunities for Middle East and North African Oil companies

    International Nuclear Information System (INIS)

    A critical analysis is provided of the recent reorganisations of the downstream and petrochemical activities of BP and Shell. BP (or BP Amoco including Arco) and Shell are preparing for the next decade anticipating the environment and changing the companies to maximise their profitability in that environment. For the oil producing countries of the Middle East and North Africa (MENA), there are lessons to be learned both from the forecasts which BP Amoco and Shell are making and from the way these companies intend to operate. BP Amoco's view of oil refining is that the surplus capacity is endemic; Shell's view is that it is transient. BP Amoco will market oil products selectively across the world; Shell is still intent on a global approach. Both BP Amoco and Shell will minimise their wholesaling activities in the retail market and expand their merchandising with ever better quality sites. In the petrochemicals sector, the companies are taking similar actions, ie concentrating on positions of strength and selling business activities with low market shares or poor profitability. Petrochemical sites will be favoured when they have access to company produced hydrocarbon feedstocks. From the analysis, it is suggested that MENA oil companies will need to consider carefully the timing of any new refinery building. The reorganisation of the major OECD-based oil companies should offer opportunities for MENA companies to secure outlets for LPG and condensates, to form marketing alliances in OECD markets and to become involved in OECD-based petrochemical businesses

  4. Comparison of the reorganisations of BP and Shell and possible opportunities for Middle East and North African Oil companies

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Gilbert

    1999-07-01

    A critical analysis is provided of the recent reorganisations of the downstream and petrochemical activities of BP and Shell. BP (or BP Amoco including Arco) and Shell are preparing for the next decade anticipating the environment and changing the companies to maximise their profitability in that environment. For the oil producing countries of the Middle East and North Africa (MENA), there are lessons to be learned both from the forecasts which BP Amoco and Shell are making and from the way these companies intend to operate. BP Amoco's view of oil refining is that the surplus capacity is endemic; Shell's view is that it is transient. BP Amoco will market oil products selectively across the world; Shell is still intent on a global approach. Both BP Amoco and Shell will minimise their wholesaling activities in the retail market and expand their merchandising with ever better quality sites. In the petrochemicals sector, the companies are taking similar actions, ie concentrating on positions of strength and selling business activities with low market shares or poor profitability. Petrochemical sites will be favoured when they have access to company produced hydrocarbon feedstocks. From the analysis, it is suggested that MENA oil companies will need to consider carefully the timing of any new refinery building. The reorganisation of the major OECD-based oil companies should offer opportunities for MENA companies to secure outlets for LPG and condensates, to form marketing alliances in OECD markets and to become involved in OECD-based petrochemical businesses.

  5. Neoproterozoic-middle Paleozoic tectono-magmatic evolution of the Gorny Altai terrane, northwest of the Central Asian Orogenic Belt: Constraints from detrital zircon U-Pb and Hf-isotope studies

    Science.gov (United States)

    Chen, Ming; Sun, Min; Buslov, Mikhail M.; Cai, Keda; Zhao, Guochun; Zheng, Jianping; Rubanova, Elena S.; Voytishek, Elena E.

    2015-09-01

    The Gorny Altai terrane (GA) is a key area in understanding the crustal evolution of the Central Asian Orogenic Belt (CAOB). This paper reports U-Pb and Hf-isotope data for detrital zircons from Cambrian to early Devonian sedimentary sequences to constrain their provenance, as well as the tectono-magmatic events and crustal growth in this region. Nearly all the detrital zircons are characterized by euhedral to subhedral morphology, high Th/U ratios (ca. 0.1-1.6) and typical oscillatory zoning, indicating a magmatic origin. The three samples from the Gorny Altai Group (middle Cambrian to early Ordovician) yield detrital zircon populations that are composed predominantly of 530-464 Ma grains, followed by a subordinate group of 641-549 Ma old. The Silurian and Devonian samples exhibit similar major zircon populations (555-456 Ma and 525-463 Ma, respectively), but a significant amount of additional 2431-772 Ma zircons occur in the early Devonian sample. Our results suggest that detritus from the nearby Kuznetsk-Altai intra-oceanic island arc served as a unitary source for the Cambrian-Silurian sedimentary sequences, but older detritus from other sources added to the early Devonian sequence. The low abundance of ca. 640-540 Ma detrital zircons may testify that this island arc was under a primitive stage in this period, when mafic volcanic rocks probably dominated. In contrast, the dominant population of ca. 530-470 Ma zircons may indicate an increased amount of granitic rocks in the source area, suggesting that the Kuznetsk-Altai island arc possibly evolved into a mature one in the Cambrian to early Ordovician. The ca. 530-470 Ma detrital zircons are almost exclusively featured by positive εHf(t) values and have two-stage Hf model ages of ca. 1.40-0.45 Ga, indicating that the precursor magmas were sourced predominantly from heterogeneous juvenile materials. We conclude that the late Neoproterozoic to early Paleozoic magmatism in the Kuznetsk-Altai arc made a

  6. Geochemical characteristics of the Shujiadian Cu deposit related intrusion in Tongling: Petrogenesis and implications for the formation of porphyry Cu systems in the Middle-Lower Yangtze River Valley metallogenic belt, eastern China

    Science.gov (United States)

    Wang, Shiwei; Zhou, Taofa; Yuan, Feng; Fan, Yu; Cooke, David R.; Zhang, Lejun; Fu, Bin; White, Noel C.

    2016-05-01

    Porphyry Cu deposits can form in intracontinental or post-collision settings; however, both the genesis of fertile magmas and the mechanism of metal enrichment remain controversial. The Shujiadian porphyry Cu deposit is located in the Tongling area of the Middle-Lower Yangtze River Valley metallogenic belt. It is hosted by the Shujiadian complex, which mainly consists of quartz diorite porphyry (143.7 ± 1.7 Ma) and pyroxene diorite (139.8 ± 1.6 Ma). They both belong to the calc-alkaline series, with enrichment in large-ion lithophile elements (LILE) and light rare earth elements (LREE), depletion in high field-strength elements (HFSE) and heavy rare earth elements (HREE), and slightly negative Eu anomalies. Both quartz diorite porphyry and pyroxene diorite have geochemical affinities with adakite, and their low MgO (1.5-3.7 wt%), and Ni (3.7-6.9 ppm), Cr (2.0-44 ppm), and Th/Ce contents (0.06-0.11) indicate that the intrusive rocks have some characteristics of adakite-like rocks derived from thickened lower crust and melts from metabasaltic rocks and eclogites. Plagioclases from the quartz diorite porphyry are andesine (An value = 31.8-40.5) and from the pyroxene diorite are felsic albite and oligoclase with large-scale zones and variable An value (An value = 8.9-18.3), Fe and Sr contents, which indicate that mixing of mafic and felsic magma may have occurred in the shallow magma chamber. Compared to the barren quartz diorite porphyry, relatively lower SiO2 contents (49.5-55.2 wt.%), higher εNd(t) values (- 7.4 to - 6.9), εHf(t) values (- 11.0 to - 9.1) compositions, Ti-in-zircon temperatures (714-785 °C), and variations of HREE contents of the mineralization-related pyroxene diorite suggest mixing with high-temperature mafic magma. Calculated Ce4 +/Ce3 + values of pyroxene diorite plot between the Ni-NiO buffer (NNO) and magnetite-hematite buffer (MH), and barren quartz diorite porphyry samples plot below the Ni-NiO buffer (NNO). Geochemical features of

  7. 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

    The Sinassi Batholith in the Central African Fold Belt (CAFB) of northern Cameroon represents the largest volume of plutonic rocks or granitoids massif of the Western Cameroonian Domain. It is made up dominantly of tonalite-trondhjemite-granodiorite (TTG) suite and lesser granite which are locally more or less deformed, and composed of varying proportions of quartz, plagioclase, K-feldspar, biotite, hornblende, sphene, magnetite, apatite and zircon. Major and trace element compositions of fifteen rock samples of granitoids (Djourdé granodiorite, Sinassi quartz diorite and orthogneisses groups) indicate that investigated rocks from the Sinassi Batholith are characterized by medium- to high-K calc-alkaline affinity and metaluminous I-type signature. In addition, their chondrite- and primitive mantle-normalized trace element patterns are strongly fractionated ((La/Yb)N = 2.96-61.40) and show respectively enrichment in LREE relative to HREE and enrichment in LILE compared to HFSE with moderate to slight negative Nb-Ta, Ti and Eu anomalies consistent with a continental magmatic arc setting related to a subduction zone. Geothermobarometric calculations using hornblende-plagioclase thermometry and aluminum-in-hornblende barometry on eleven rock samples indicate that plutons from Sinassi Batholith were emplaced at average temperatures and pressures ranging between 698 and 720 °C and 4.06-5.82 kbar (Djourdé granitoids), 698-728 °C and 4.04-5.34 kbar (Sinassi granitoids) and 667-670 and 4.23-4.76 kbar (orthogneisses group) respectively. The average emplacement depths estimates for the investigated granitoids is constrained at ca 16-18 km, indicating that at least 16 km of crustal rocks of the Sinassi Batholith must have been eroded or uplifted at approximately exhumation rates of 0.08-0.10 mm/year. Regardless of their Th/U ratios, geochronological results highlight three main events characterizing the Neoproterozoic tectonomagmatic evolution within the Sinassi Batholith

  8. Compilation of the GSHAP regional seismic hazard for Europe, Africa and the Middle East

    Directory of Open Access Journals (Sweden)

    D. Mayer-Rosa

    1999-06-01

    Full Text Available The seismic hazard map of the larger Europe-Africa-Middle East region has been generated as part of the global GSHAP hazard map. The hazard, expressing Peak Ground Acceleration (PGA expected at 10% probability of exceedance in 50 years, is obtained by combining the results of 16 independent regional and national projects; among these is the hazard assessment for Libya and for the wide sub-Saharan Western African region, specifically produced for this regional compilation and here discussed to some length. Features of enhanced seismic hazard are observed along the African rift zone and in the Alpine-Himalayan belt, where there is a general eastward increase in hazard with peak levels in Greece, Turkey, Caucasus and Iran.

  9. 东南极格罗夫山:普里兹造山带中一个典型的泛非期变质地体%THE GROVE MOUNTAINS: A TYPICAL PAN-AFRICAN METAMORPHIC TERRANE IN THE PRYDZ BELT, EAST ANTARCTICA

    Institute of Scientific and Technical Information of China (English)

    刘晓春; 赵越; 胡健民; 刘小汉; 曲玮

    2013-01-01

    The Grove Mountains, 400 km south of the Chinese Zhongshan Station, are an inland continuation of the Prydz Belt, East Antarctica. The basement terrane of the Grove Mountains consists of voluminous mafic-felsic intrusives of ca. 920-910 Ma and a small amount of Mesoproterozoic sedimentary rock. This terrane only experienced a single Pan-African (ca. 570-500 Ma) tectonometamorphic cycle and is therefore a typical Pan-African metamorphic terrane in the Prydz Belt. The Pan-African high-grade metamorphism may have reached peak pressure-temperature (P-T) conditions of 1. 18-1.40 GPa and 770-840℃ , rather than low-to medium-pressure granulite facies as previously thought. This peak metamorphism was then followed by a near-isothermal decompression of about 0. 6 GPa. Numerous A-type charnockites and granites intruded in the metamorphic terrane during syn- to post-orogenic episodes, which resulted in a late near-isobaric cooling of the terrane. These granitoids were probably generated by partial melting of the underplating materials (alkaline basaltic rocks) derived from a long-term enriched subcontinental lithospheric mantle. Coupled with available data from other localities, we infer that the Prydz Belt developed on Archean-Grenvillian basement terranes. Subsequently, these basement terranes and Neoproterozoic cover sequences may have suffered from the same Pan-African orogenic event. The crust of the Prydz Belt was thickened to around 40-50 km, followed by about 20 km of exhumation during the Pan-African orogenesis. Accordingly, the Prydz Belt should represent a Pan-African collisional zone as a consequence of the East Gondwana assembly.%距中国中山站以南约400 km的格罗夫山是普里兹造山带向南极内陆的延伸部分,其基底地体由约在920-910 Ma期间侵入的镁铁质-长英质火成岩和少量中元古代的沉积岩构成,这些岩石仅在泛非期(约570-500 Ma)经历了单相变质—构造旋回,因此是一个典型的泛非期变质

  10. Dynamic characteristics of conveyor belts

    Institute of Scientific and Technical Information of China (English)

    HOU You-fu; MENG Qing-rui

    2008-01-01

    The dynamic characteristics of a belt conveyor are determined to a large extent by the properties of the belt. This paper describes experiments designed to establish the dynamic properties of belting material. The dynamic elastic modulus, viscous damping and theological constants of the belt were measured. Several properties were studied as a function of the tensile loading on the belt. These included longitudinal vibration, the natural vibration frequency in the transverse direction and the response to an impulse excitation. Vibration response was observed under several different excitation frequencies. Most of these properties have not been tested previously under conditions appropriate for the ISO/DP9856 standard. Two types of belt were tested, a steel reinforced belt and a fabric reinforced belt. The test equipment was built to provide data appropriate for designing belt conveyors. It was observed that the stress wave propagation speed increased with tensile load and that tensile load was the main factor influencing longitudinal vibrations.

  11. "Get up off that Thing": African American Middle School Students Respond to Literature to Develop a Framework for Understanding Social Action

    Science.gov (United States)

    Tyson, Cynthia A.

    2002-01-01

    The use of children's literature in urban social studies classrooms to facilitate students' engagement in literate behaviors and simultaneously develop a framework for understanding social action is an under-researched area. This paper discusses the use of literature for children and young adults in an urban middle school language arts and social…

  12. The Pattern and Evolution of the Permian Palaeobiogeography and Tectonic Palaeogeography in Jilin and Heilongjiang Orogenic Belt

    Institute of Scientific and Technical Information of China (English)

    Peng Xiangdong; Li Xiaomin; Liu Pengju

    2000-01-01

    The orogenic belt locates between the North China plate and Siberia plate. The Permian palaeobiogeography and tectonic palaeogeography changed quickly and clearly. The line from Changchun to Yanji is an important palaeobiogeographic provincing line, which may be the collission suture belt of the North China plate and north middle massifs. The orogenic belt has been divided into 2 regions: the North middle massif region and the North Margin of North China plate, the pattern and evolution of Permian palaeobiogeography in the present area were discussed and the Permian biota mixture and its significants were analysed. Then, Based on the above, the Permian tectonic palaeogeography of the orogenic belt is reconstructed.

  13. Learning to "see" sound: An investigation into the intellectual and linguistic resources that urban middle school African American boys utilize in the practice of representing sound transmission

    Science.gov (United States)

    Wright, Christopher G.

    2011-12-01

    This research examines the intellectual and linguistic resources that a group of African American boys brought to the study of the science of sound and the practice of representation. By taking a resource-rich view of the boys' linguistic and representational practices, my objective is to investigate children's abilities in producing, using, critiquing, and modifying representations. Specifically, this research looks to explore and identify the varieties of resources that African American boys utilize in developing scientific understanding. Using transcripts from group sessions, as well as the drawings produced during these sessions, I utilized a combination of discourse analysis to explore the boys' linguistic interactions during the critique of drawings with a focus on the boys' manipulation of line segments in order to explore their representational competencies. Analysis of the transcripts and the boys' drawings revealed several important findings. First, elements of Signifying were instrumental in the group's collective exploration of each other's drawings, and the ideas of sound transmission being represented in the drawings. Thus, I found that the boys' use of Signifying was key to their engagement win the practice of critique. Second, the boys' ideas regarding sound transmission were not fixed, stable misconceptions that could be "fixed" through instruction. Instead, I believe that their explanations and drawings were generated from a web of ideas regarding sound transmission. Lastly, the boys exhibited a form of meta-representational competency that included the production, modification, and manipulation of notations used to represent sound transmission. Despite this competency, the negotiation process necessary in constructing meaning of a drawing highlighted the complexities in developing a conventional understanding or meaning for representations. Additional research is necessary for exploring the intellectual and lingustic resources that children from

  14. Post-Variscan evolution of the Anti-Atlas belt of Morocco constrained from low-temperature geochronology

    Science.gov (United States)

    Gouiza, M.; Charton, R.; Bertotti, G.; Andriessen, P.; Storms, J. E. A.

    2016-04-01

    The Anti-Atlas belt of Morocco extends ENE-WSW, over more than 600 km, from the Atlantic margin in the west to the interior of the African plate in the east. It exhibits Precambrian rocks outcropping as basement inliers and surrounded by marine Ediacaran-Cambrian sequences around the axis of the mountain range. The belt, which has for a long time been interpreted as of Variscan age, is now revealed to have experienced major vertical movements through Mesozoic and Cenozoic times. Thereby, the Anti-Atlas domain appears to be affected by two episodes of exhumation separated by an episode of subsidence. The initial episode occurred in the Late Triassic and led to the exhumation of 7.5-10.5 km of crustal rocks by the end of the Middle Jurassic (ca. 160-150 Ma). The following phase resulted in 1-3 km of basement subsidence and occurred during the Late Jurassic and most of the Early Cretaceous. The basement rocks were then slowly brought to the surface after experiencing 2-3.5 km of exhumation throughout the Late Cretaceous and the Cenozoic. The timing of these episodes of exhumation and subsidence coincides with major tectonic and thermal events in relation with the evolution of the Atlantic and Tethys Oceans, indicating that the effects of their rifting and drifting extended beyond their presumed margins.

  15. Trace and rare-earth element geochemistry: A tool for petrogenetic and geotectonic modeling of ensi-matic ortho-amphibolites from Pan-African belt of Obudu Plateau, Southeastern Nigeria

    Institute of Scientific and Technical Information of China (English)

    Ukaegbu V.U.; Beka F.T.

    2009-01-01

    A model for the petrogenetic affinity and original geotectonic setting of ortho-amphibolites from the Obudu Plateau was tested using the distribution patterns of trace and rare-earth elements from the geochemical analyses of twelve representative amphibolite samples. Discrimination plots, normalized patterns of the incompatible trace elements against average MORB, low ratios of Ba/Nb (9-23) and Ba/Ta (130-327) and other geochemical characteristics suggest that the protoliths were dominantly of tholeiitic MORB composition. The values of the ratios of La/Ta (8.13-10.8), Rb/Sr (0.044).07), Th/U (mainly 4.43-5.43) and Hf/Ta (2.35-2.88) further indicate that the ortho-amphibolites demonstrate E-type MORB characteristics. These features are related to substantial ocean floor divergent tectonic boundary setting rather than marginal basin tectonic setting. This evolutionary pattern appears to be controlled by limited progressive partial melting and fractional crystallization of a single mantle source region, irrespective, however, of variations due to local source heterogeneities. The tholeiitic magmas were most probably generated by hotspot activities on the constructive plate margins and subsequently modified by subduction-related low-K tholeiitic chemistry due to narrowing of a proto oceanic basin between the West African craton and eastern Sahara plate. A likely model, therefore, is that the amphibolites of the Obudu Plateau represent ophiolitic suites with characteristics of enriched mid-ocean floor tholeiites, which were deformed and metamorphosed during a reversed plate motion involving subduction and collision within the Obudu Plateau in the Pan-African orogenic episode.

  16. Belt-up!

    Energy Technology Data Exchange (ETDEWEB)

    Woof, M.

    1999-07-01

    Advanced control systems, improved materials and new dust control systems have turned the humble conveyor belt into a sophisticated method for transporting materials. RJB Mining has improved productivity at the Price of Wales colliery in Yorkshire, UK, with the installation of Alstom`s VDM drive system; Qualter Hall`s upgraded conveyor system at the Rugely Power Station in the UK is proving its ability to minimise coal spillage. The article highlights advances by several manufacturers in conveyor technology. 5 photos.

  17. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September. This activity was launched by Hengyuanxiang,aleading Chinese wool manufacturer.

  18. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September.This activity was launched by Hengyuanxiang,a leading Chinese wool manufacturer.

  19. Lap belt injuries in children.

    LENUS (Irish Health Repository)

    McGrath, N

    2010-07-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children\\'s hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  20. Belt conveyor for recycle aggregate

    OpenAIRE

    Bezrodný, Roman

    2014-01-01

    This bachelor thesis deals with the belt conveyor for the transport of recycled aggregate in an oblique direction. The aim is to find constructional solutions to the belt conveyor for the assigned transport capacity of 95 000 kg per hour, and the assigned axial distance of 49 m and different height of 12 m. The thesis contains a brief description of the belt conveyor and a description of basic constructional components. It also contains a functional calculation of the capacity and forces acco...

  1. SLH Timing Belt Powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abe

    2014-04-09

    The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon- fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning

  2. Cenozoic intracontinental deformation of the Kopeh Dagh Belt, Northeastern Iran

    Science.gov (United States)

    Chu, Yang; Wan, Bo; Chen, Ling; Talebian, Morteza

    2016-04-01

    arc magmatism. During the Jurassic to Eocene rifting, this belt acted as the southern boundary of the Amu Darya Basin with normal faulting, which is also widespread in the South Caspian Sea and the Black Sea. Moreover, such an extended area became a relatively weak zone within the Eurasian Plate, and could be easily reworked. Because of the collision in the Zagros Belt, the intracontinental compression commenced as early as Late Eocene to Early Oligocene, which is interpreted as tectonic inversion along this weak zone. The western zone of the Kopeh Dagh Belt was also affected by southerly indentation/extrusion of the South Caspian block since middle Miocene, possibly resulting in the different deformation patterns between the western and eastern zones.

  3. Extensive Admixture and Selective Pressure Across the Sahel Belt.

    Science.gov (United States)

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-11-26

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).

  4. Geography of the asteroid belt

    Science.gov (United States)

    Zellner, B. H.

    1978-01-01

    The CSM classification serves as the starting point on the geography of the asteroid belt. Raw data on asteroid types are corrected for observational biases (against dark objects, for instance) to derive the distribution of types throughout the belt. Recent work on family members indicates that dynamical families have a true physical relationship, presumably indicating common origin in the breakup of a parent asteroid.

  5. A partial distal humerus from the Middle Pleistocene deposits at Bodo, Middle Awash, Ethiopia

    OpenAIRE

    Carretero, José Miguel; Haile Selassie, Yohannes; Rodríguez García, Laura; Arsuaga, Juan Luis

    2009-01-01

    The Bodo partial distal humerus with an approximate age of 0.6 million years is one of the very few postcranial remains from the African Middle Pleistocene. Despite its fragmentary status, comparisons of the Bodo humerus with other fossil hominid and modern human samples reveal some insights into African hominids of this time period. The Bodo partial humerus displays distal humeral features very common in the European Middle and Late Pleistocene hominids, such as a relatively w...

  6. 海拉尔塔木察格盆地中部断陷带油气形成条件及富集规律%Formation and Accumulation Rules of Oil and Gas in Middle Fault Depression Belt of Hailar Tamtsag Basin

    Institute of Scientific and Technical Information of China (English)

    蒙启安; 刘一丹; 吴海波; 李军辉; 刘赫

    2014-01-01

    The oil and gas reservoir in the middle fault depression belt of Hailar-Tamtsag basin shows great potential and with large scale.They distribute widespread in the Cretaceous sequences. Although it has been provided with favorable geology and accumulation conditions of oil and gas,and serves as the key field of oil and gas exploration in the future,the formation and accumulation rules are not clear.Based on integrated statistic analysis and geological data, we focus on the formation, distribution,and accumulation of oil and gas reservoir in the area.The controlling factors are as follows.First,multi-period structural movement controlled the basin framework and established the structural pattern of depression with rich oil accumulation.Second,different tectonic phase controlled the sedimentary infilling evolution.The fault slope break belt and structural transfer zone controlled the fan body distribution.All of them supply advantageous reservoir for oil and gas accumulation with great scale.Third,clastic rock with high content of volcanic substance was easy to dissolve,which resulted in the development of secondary pore,and it created beneficial condition for the formation of favorable reservoirs.We therefore that concluded that the concave uplift belt of composite half-graben fault depression and the great gentle slope fault terrace belt served as favorable oil and gas reservoir. Hydrocarbon kitchen controlled the distribution of oil and gas reservoir.The favorable facies belt was an important factor for oil and gas enrichment.The results may be useful for the consideration in similar petroleum system exploration.%海拉尔塔木察格盆地中部断陷带油气藏具有很大的资源潜力和储量规模,在白垩系均有广泛的分布,具备良好的油气地质背景和成藏条件,是未来油气勘探的重点领域,其形成条件及富集规律不明。笔者在大量统计分析和地质研究的基础上,探讨了中部断陷带油气藏的

  7. Multi-information-based metallogenic prediction of skarn-type copper polymetallic deposit in the middle segment of Nanjing-Zhenjiang Mesozoic magmatic belt%宁镇中段夕卡岩型铜多金属矿床多元信息成矿预测初步研究

    Institute of Scientific and Technical Information of China (English)

    张术根; 余旭辉; 徐莺

    2011-01-01

    宁镇中段铜多金属矿床主要为接触交代型矿床.文章以地质环境和成矿规律研究为基础,采用逻辑信息法综合提取地质、遥感、地球物理和地球化学多层次成矿预测信息,构建逻辑信息法成矿预测要素组合.并以此为指导,按照地质成矿条件有利程度、物化探异常强度与规模、环形构造发育程度、遥感解译蚀变显现强度与规模,进行综合判别确定成矿有利位置,圈定区内夕卡岩型矿床重点找矿靶区.%In the middle segment of Nanjing-Zhenjiang Mesozoic magmatic belt, the copper polymetallic deposits are dominated by contact metasomatic type. Based on the geological environment and metallogenic regularity the logical-information method is used to extract multi-metallogenic prediction (geological,remote-sensing, geophysical and geochemical) information of skarn-type cooper polymetallic ores. With this method and comprehensively analyzing the favorable degree of geological metallogenetic conditions,intensity and scale of geophysical-geochemical anomalies, development degree of circular structure, intensity and scale of RS-interpretation alteration, the favorable positions of mineralization are determined, and the key prospecting target area of skarn-type copper deposits in the study area are also delineated. Finally,the potential of the key prospecting target area is discussed in detail.

  8. Chaos on the conveyor belt

    CERN Document Server

    Sándor, Bulcsú; Tél, Tamás; Néda, Zoltán

    2013-01-01

    The dynamics of a spring-block train placed on a moving conveyor belt is investigated both by simple experiments and computer simulations. The first block is connected by spring to an external static point, and due to the dragging effect of the belt the blocks undergo complex stick-slip dynamics. A qualitative agreement with the experimental results can only be achieved by taking into account the spatial inhomogeneity of the friction force on the belt's surface, modeled as noise. As a function of the velocity of the conveyor belt and the noise strength, the system exhibits complex, self-organized critical, sometimes chaotic dynamics and phase transition-like behavior. Noise induced chaos and intermittency is also observed. Simulations suggest that the maximum complexity of the dynamical states is achieved for a relatively small number of blocks, around five.

  9. African Muslim Youth and the Middle East

    DEFF Research Database (Denmark)

    Ihle, Annette Haaber

      Streams of global information create a call for foreign places, same as new ideas of the world tend to enhance people's wish to move across borders to new continents. Such is also the case with young people in an Africa, which has over the last thirty years been going through a development......, marked by economic decline and political instability. In Africa a weak or even failed state often means that young people have in reality no access to political, educational or economic positions and resources. In some countries like Nigeria, Ghana and the Ivory Coast the marginalisation of the youth...

  10. Utility, Status and Languages in Competition in Middle Belt Nigeria

    OpenAIRE

    ARASANYIN, Olaoba F.

    1995-01-01

    The diglossic principle implanted into sociolinguistic discourse in the late 1950's afforded a conceptual frame where traditional paradigms and novel parameters for theorizing language within multilingual management coincide and interpenetrate. To Nigeria's multilingual situation, the principles of triglossia have been introduced on two conceptual levels: policy management and public response to policy. However, dimorphous symbiosis between policy guidelines and the attendant applicatory disp...

  11. Cancer and African Americans

    Science.gov (United States)

    ... Population Profiles > Black/African American > Cancer Cancer and African Americans African Americans have the highest mortality rate ... 65MB] At a glance – Top Cancer Sites for African Americans (2008-2012) Cancer Incidence Rates per 100, ...

  12. Kuiper Belts Around Nearby Stars

    CERN Document Server

    Nilsson, R; Brandeker, A; Olofsson, G; Pilbratt, G L; Risacher, C; Rodmann, J; Augereau, J -C; Bergman, P; Eiroa, C; Fridlund, M; Thébault, P; White, G J

    2010-01-01

    In order to detect and characterise cold extended circumstellar dust originating from collisions of planetesimal bodies in disks, belts, or rings at Kuiper-Belt distances (30--50\\,AU or beyond) sensitive submillimetre observations are essential. Measurements of the flux densities at these wavelengths will extend existing IR photometry and permit more detailed modelling of the Rayleigh-Jeans tail of the disks spectral energy distribution (SED), effectively constraining dust properties and disk extensions. By observing stars spanning from a few up to several hundred Myr, the evolution of debris disks during crucial phases of planet formation can be studied. // We have performed 870\\,$\\mu$m observations of 22 exo-Kuiper-Belt candidates, as part of a Large Programme with the LABOCA bolometer at the APEX telescope. Dust masses (or upper limits) were calculated from integrated 870\\,$\\mu$m fluxes, and fits to the SED of detected sources revealed the fractional dust luminosities $f_{\\mathrm{dust}}$, dust temperatures...

  13. Some problems of geologic relations between the Amazon craton and east margins fold belts

    International Nuclear Information System (INIS)

    This paper deals with some geologic problems related to the limits between the Amazon craton and the fold belts developed at its margins during the Precambrian. These limits are diversified but clearly recognized. To the north, the Araguaia-Tocantins fold belt, of presumed Middle Proterozoic age, is separated from the cratonic block by a deep marginal fracture zone permeated by mafic and ultramafic rocks. The geologic, magmatic and aeromagnetic characteristics of this zone point out the presence of deep faults, supposed to be of Middle Proterozoic age. The southern Paraguay fold belt constitutes and accurated zone of linear structures supposed to be of Late Proterozoic development. Despite the great increase of knowledge during the last ten years many tectonic, stratigraphic and geochronologic problems remain unsolved. The aim of this paper is to point out some of these problems and suggest specific studies to solve them. (author)

  14. 长江中下游成矿带抛刀岭大型斑岩型金矿特征及找矿前景%Characteristics and Prospects of Paodaoling Large Porphyry Gold Deposit in the Middle-lower Yangtze River Metallogenic Belt

    Institute of Scientific and Technical Information of China (English)

    段留安; 杨晓勇; 汪方跃

    2014-01-01

    抛刀岭金矿位于长江中下游成矿带安庆-池州矿集区,累计金金属量大于22 t ,为池州地区首例大型金矿床。该矿床金矿体主要产在英安玢岩中,基本不伴生其他有益金属元素,为独立金矿床。通过详细的矿床地质特征描述,结合已有斑岩型金矿的成矿模式,同时利用以往对该含矿岩体U-Pb锆石定年及相关地球化学研究,综合分析认为该矿为产在早白垩纪岛弧背景下的贫铜斑岩型金矿床,同时局部矿段在成矿过程中还经历了热液叠加作用。矿体产出严格受 NE向构造岩浆岩带控制,含矿岩体出露面积小于1.0 km2,属于典型的小岩体成大矿。运用“相似类比”、“矿床谱系”、“趋势外推”、“综合信息评价”等原则,指出该矿具有特大型金矿的潜质;同时,受同一 NE向构造控制的乌石、白虎山及自来山等同期岩浆岩发育地区,具有与抛刀岭金矿类似的成矿条件,是未来工作的重点靶区;发育于上述同期岩浆岩之间的志留纪地层中的破碎带蚀变岩、与斑岩型矿床配套产出的低温热液多金属硫化物型矿床等,都将是外围工作的重点研究地区。%Paodaoling gold deposit is located in Anqing-Chizhou ore concentrated area of the middle-lower Yangtze River metallogenic belt.It is the first large gold deposit discovered in Chizhou area with more than 22 t gold.Paodaoling gold deposit is independent with little other economic metal elements,and develop mainly in dacite-porphyrite.According to the detailed description of geological characteristics of gold deposit,combined with the metallogenic model of porphyry gold deposit and the characteristics of zircon U-Pb dating and geochemistry,it is proposed that Paodaoling gold deposit is a Cu-poor porphyry gold deposit formed in Early Cretaceous arc environment,and part of ore blocks experiences hydrothermal alteration.Ore bodies,which are

  15. Clay minerals assemblage in the Neogene fluvial succession of the Pishin Belt, Pakistan

    DEFF Research Database (Denmark)

    Kasi, Aimal Khan; Kassi, Akhtar Muhammad; Friis, Henrik;

    2014-01-01

    The Neogene siliciclastic succession of the Pishin Belt comprises the newly proposed Middle to Upper Miocene Dasht Murgha group, Miocene-Pliocene Malthanai formation and Pleistocene Bostan Formation. Sandstones of the succession have been classified as lithic arenites and their detrital modes ind...

  16. Support Needs of Overweight African American Women for Weight Loss

    Science.gov (United States)

    Thomas, Janet L.; Stewart, Diana W.; Lynam, Ian M.; Daley, Christine M.; Befort, Christie; Scherber, Robyn M.; Mercurio, Andrea E.; Okuyemi, Kolawole S.; Ahluwalia, Jasjit S.

    2009-01-01

    Objectives: To examine social support needs of obese and overweight African American women for weight loss. Methods: Focus groups were conducted with overweight and obese African American women. Data were analyzed using standard grounded theory text analysis. Results: Our middle-aged (45.7 years; SD = 12.6) women (N = 66) were interested in…

  17. French experience in seat belt use.

    NARCIS (Netherlands)

    Lassarre, S. & Page, Y.

    1992-01-01

    This paper concerns the French experience in seat belt use. As well as the seat belt regulations, the strategies employed to reinforce the wearing of seat belts by using information and encouragement campaigns and checks by the police and gendarmerie are described here along with their timetables an

  18. Study of thermal conditions at belt slippage

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, R.; Pampel, W.; Pfleger, P.

    1987-04-01

    Conveyor belt slippage experiments are carried out on the Chrudim (Czechoslovakia) industrial sized test stand for belt widths up to 1 m and driving drum forces up to 400 kW. The stand is operated jointly by TAKRAF (GDR) and VITKOVICE VUTZ, Prague. From 1972 to 1981, 7 belt conveyor fires occurred in GDR brown coal surface mines due to belt slippage. One of these cases led to a belt fire after only 15 s at 100% belt slippage. Aim of the study was to determine accurate permissible slippage values. Design of the test stand is explained as well as test procedures with belt slippage at the driving drum varying between 10 and 100%. Belt driving parameters were measured along with temperature of the drum surface. The heat penetration parameter b (in kJ/m/sup 2/) was calculated. Maximum temperatures up to 150 C were measured on the drum during partial slippage and 370 C at 100% belt slippage. The ignition temperature of rubber abrasion fines was also analyzed and found to vary between 40 and 318 C, i.e. substantially lower than belt and drum layer ignition temperatures. Graphs and diagram of slippage measurement results are calculated. Values for permissible maximum slippage time for operating belt slippage monitoring devices are shown. These devices are required to be installed in the GDR at heavy mine belt conveyors with driving forces exceeding 500 kW. 8 refs.

  19. African dance

    OpenAIRE

    Mumberson, Stephen

    2012-01-01

    The RE Open will be shown at the Mall Gallery London and the international section was judged by major practitioners and educators, print dealers and collectors, President of RE and Keeper of the Ashmolean Museum Dr Bren Unwin, John Purcell, Deborah Roslund, Colin Harrison, Dave Ferry, and Mark Hampson. Piece selected "African Dance" print.

  20. "African Connection."

    Science.gov (United States)

    Adelman, Cathy; And Others

    This interdisciplinary unit provides students in grades kindergarten through seventh grade an opportunity to understand diversity through a study of Africa as a diverse continent. The project is designed to provide all elementary students with cultural enrichment by exposing them to African music, art, storytelling, and movement. This project can…

  1. Partnerships in the Middle East: Interventionist Endeavors?

    DEFF Research Database (Denmark)

    Aarøe Jørgensen, Jakob

    2014-01-01

    This chapter aims to analyse NATO’s two Middle Eastern and North African (MENA)1 partnership programmes – the Mediterranean Dialogue (MD) and the Istanbul Cooperation Initiative (ICI). The chapter aims to answer the questions: (1) why does NATO engage with MENA partners; (2) what are the obstacles...... that MD and ICI face, and; (3) is the new flexible partnership policy a step towards more constructive Middle Eastern partnerships?...

  2. New investigations in southwestern Guinea: consequences for the Rokelide belt (West Africa)

    Science.gov (United States)

    Villeneuve, Michel; Bellon, Hervé; Corsini, Michel; Le Metour, Joël; Chatelee, Sébastien

    2015-07-01

    The southern Guinean terranes belong to the "Rokelide belt" that is located in the southwestern part of the West African craton (Senegal to Liberia). Field investigations and K-Ar and 40Ar-39Ar radiometric analysis performed on samples collected from southern Guinea provide a new interpretation for metamorphic terranes not yet dated. A K-Ar whole-rock age of a gneiss and 40Ar-39Ar plateau ages of amphiboles separated from a mylonitic gneiss of the Ouankifondi formation and a gneiss from the Kissi-Kissi formation yield several Pan-African metamorphic ages at circa 650, 560, and 530 Ma, respectively. Field investigations show that these formations are unconformably capped by the Kolente group. The previous structural framework and the geodynamic evolution of the Rokelide belt based on the coeval evolution of the Ouankifondi and Kissi-Kissi formations and the Kolente group are reassessed. The Rokelide belt is linked to the Bassaride belt. Correlations with adjacent Sierra Leonean terranes and with northern Guinea and Senegal are considered.

  3. Ideal Body Size as a Mediator for the Gender-Specific Association between Socioeconomic Status and Body Mass Index: Evidence from an Upper-Middle-Income Country in the African Region

    Science.gov (United States)

    Yepes, Maryam; Maurer, Jürgen; Stringhini, Silvia; Viswanathan, Barathi; Gedeon, Jude; Bovet, Pascal

    2016-01-01

    Background: While obesity continues to rise globally, the associations between body size, gender, and socioeconomic status (SES) seem to vary in different populations, and little is known on the contribution of perceived ideal body size in the social disparity of obesity in African countries. Purpose: We examined the gender and socioeconomic…

  4. 长江中下游成矿带贵池抛刀岭金矿含矿岩体年代学及地球化学研究%Geochemistry and zircon U-Pb age of ore-bearing porphyry in the Paodaoling gold deposit in Guichi, Middle-Lower Yangtze metallogenic belt

    Institute of Scientific and Technical Information of China (English)

    段留安; 杨晓勇; 汪方跃; 邓江洪; 孙卫东

    2012-01-01

    贵池抛刀岭金矿位于长江中下游成矿带安庆-贵池矿集区,是该地区首次发现的独立玢岩型金矿床,含矿岩体主要为蚀变矿化的英安玢岩.经过近两年的地质勘查,该矿床已接近大型金矿床规模.通过对抛刀岭金矿含矿岩体锆石LA-ICPMS U-Pb测定,其成岩年龄为146.8±2.4Ma和141.3±1.0Ma(2σ),与长江中下游地区中生代大规模铜金成矿事件时间一致.全岩地球化学研究表明,该岩石为过铝质,富集大离子亲石元素(K、Rb、Pb),亏损高场强元素(Nb、Ta、Ti)和轻稀土富集等地球化学特征.较高的锆石Ce4+/Ce3+和EuN/EuN*显示抛刀岭含矿岩体具有较高的氧逸度特征.构造判别图解显示这套含矿岩石属火山弧花岗岩(VAG),与长江中下游铜金矿床含矿岩体形成于同一构造背景下,即太平洋俯冲作用引起的洋壳和地幔楔熔融形成.%The Paodaoling gold deposit is the first discovered porphyry type gold deposit in Anqing-Guichi ore-cluster region in the Middle-Lower Yangtze metallogenic belt ( LYRB). The host rocks of the Paodaoling gold deposit are trachyte andesitic porphyries. Zircon LA-ICP-MS U-Pb dating of two ore-bearing porphyries are 146. 8 ±2. 4Ma and 141. 3 ± 1. OMa (2σ) , according with the main mineralization time of LYRB. Whole rock geochemistry indicates that the ore-bearing porphyries are peraluminous, enriched in K-Rb-Pb and light REE, depleted in Nb-Ta-Ti, similar to crustal origination. These porphyries show volcanic arc granite affinities. The higher ratios of Ce4+ VCe3+ and Eun/Eun, calculated from zircon data indicate that the Paodaling intrusion has higher oxygen fugacity with potentiality for Au formation. We conjecture that the Paodaoling gold deposit was probably related to melting of mantle wedge during subduction between Paleo-Pacific plate and Izanagi plate.

  5. The geology of the Matala Dome: an important piece of the Pan-African puzzle in Central Zambia

    Science.gov (United States)

    Naydenov, K. V.; Lehmann, J.; Saalmann, K.; Milani, L.; Poterai, J.; Kinnaird, J. A.; Charlesworth, G.; Kramers, J. D.

    2016-04-01

    The Matala Dome (MD), an ENE-trending structure located at the junction between the Pan-African Lufilian and Zambezi belts, is cored by a Gneiss-Schist Unit with uncertain age overlain by a metasedimentary section (Quartzite-Schist Unit, Marble Unit and Carbonate-Siliciclastic Unit) of the Neoproterozoic to Cambrian Katanga Supergroup. The top of the Katangan stratigraphy is represented by synorogenic sedimentary rocks—Upper Siliciclastic Unit. An early event D1 resulted in the development of shallow-dipping metamorphic foliation S1 and pre- to syntectonic growth of garnet and kyanite in the schists of the Quartzite-Schist Unit. Pseudosections and garnet isopleth modelling on schist from this unit defined the peak metamorphism at P = 7.5-9.3 kbar and T = 620-700 °C. U-Pb detrital zircon dating revealed ca. 2.7 Ga source and a high-grade metamorphism during Pan-African times. The S1 foliation was affected by upright folding F2 with ENE-trending axes and associated subvertical crenulation fabric S2 development. The syn-D2 retrogression in the schists is marked by post-S1 staurolite crystallisation and further by chloritisation followed by sericitisation. The D2 event is interpreted to have exhumed the orogenic middle crust and to be responsible for the domal structure of the MD. 40Ar/39Ar dating of muscovite at 529.3 ± 5.6 to 526.3 ± 6.2 is interpreted to date the exhumation event. D2 is correlated with regional N-S shortening event at ca. 530-520 Ma. Based on the lithology, structural record, and time and facies of the metamorphism, a correlation between the MD and the northern part of the Zambezi Belt is suggested.

  6. Tectonic Evolution of the Northern Continental Margin of North China Platform in Middle Proterozoic

    Institute of Scientific and Technical Information of China (English)

    Xu Zhongyuan; Liu Zhenghong

    2000-01-01

    An orogenic belt developed in late middle Proterozoic in the northern margin of North China Plate extends from Inner Mongolia to Western Liaoning Province and Eastern Jilin Province. It is over 2000km long. The orogenic belt was formed by collision between North China Platform and Siberia Platform during the Rodinian Super- Continent period. From sedimentary formation, magmatic activity and crustal tectonic deformation, it is suggested that along the tectonic belt the paleocontinental margin experienced four stages of tectonic evolution in middle Proterozoic, they are: continental margin rift,passive continental margin, active continental margin and collisional orogenic stages.

  7. Uplift of the South African Plateau: mantle-scale deformation, long wavelength relief growth and offshore sediment budget

    Science.gov (United States)

    Guillocheau, François; Dauteuil, Olivier; Baby, Guillaume; Robin, Cécile

    2013-04-01

    The South African Plateau is one of the largest very long wavelength relief (x1000 km) of the world that could be related to mantle dynamics and the effect of the African superplume. Unfortunately, the timing of the uplift and the different steps of the relief growth are still debated with a Late Cretaceous uplift scenario and an Oligocene one. Whatever model, few attentions were paid to the evolution of the overall geomorphic system, from the upstream erosional system to the downstream depositional system. This study is based, onshore, on the mapping and chronology of all the macroforms (weathering surfaces and associated alterites, pediments and pediplains, incised rivers, wave-cut platforms) dated by intersection with the few preserved sediments and the volcanics (mainly kimberlites pipes) and, offshore, on a more classical dataset of seismic lines and petroleum wells (characterization and dating of forced regression, sediment volume measurement, etc..). The main result of this study is that the South African Plateau is an old Late Cretaceous Plateau reactivated during Paleogene times and fossilized since the Middle Miocene. • During Late Cretaceous, in a semiarid climatic setting, the main uplift occurred from the east (around 95 Ma) to the west (around 75 Ma) and could result from the migration of the African plate over the African superplume: This is the paroxysm of the erosion with the growth of a large delta offshore present-day Orange River mouth (sedimentation rate around 100 000 km3/Ma). • During Paleocene - Mid Eocene times, in more humid conditions and in response to a more subtle long wavelength deformation, pedimentation occurred mainly localised along Cape Fold Belt feeding a large delta offshore western Cape Peninsula. During Mid Eocene times, all those landscapes are fossilized and weathered by laterites. • Late Eocene and Oligocene is the second period of uplift of the Plateau, localised along its Indian Ocean side (Drackensberg Moutains

  8. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  9. Predicting Early Adolescent Gang Involvement from Middle School Adaptation

    Science.gov (United States)

    Dishion, Thomas J.; Nelson, Sarah E.; Yasui, Miwa

    2005-01-01

    This study examined the role of adaptation in the first year of middle school (Grade 6, age 11) to affiliation with gangs by the last year of middle school (Grade 8, age 13). The sample consisted of 714 European American (EA) and African American (AA) boys and girls. Specifically, academic grades, reports of antisocial behavior, and peer relations…

  10. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  11. NONLINEAR DYNAMIC BEHAVIOR OF VISCOELATIC TRANSMISSION BELT

    Institute of Scientific and Technical Information of China (English)

    Li Yinghui; Gao Qing; Jian Kailin; Yin Xuegang

    2003-01-01

    The nonlinear dynamic responses of viscoelastic axially transmission belts are investigated and the Kelvin viscoelastic differential constitutive model is employed to characterize the material property of belts. The generalized equation of motion is obtained for a viscoelatic axially transmission belts with geometric nonlinearity first, and then is reduced to be a set of second-order nonlinear ordinary differential equations by applying Galerkin's method. Finally, the effects of viscosity parameter and elastic parameter and the moving velocity of the belts on the transient responses are investigated by the research of digital simulation.

  12. "It's Hard Answering Your Calling": Teacher Teams in a Restructuring Urban Middle School

    Science.gov (United States)

    Tonso, Karen L.; Jung, Maura Lobos; Colombo, Marie

    2006-01-01

    Considered a successful university-operated, urban middle school serving an overwhelmingly African American student body, "Charter" Middle School was dechartered suddenly, then merged a year later with students from a neighborhood school to become "Choice" Middle School, a school of choice in the urban district. Using a situated learning framework…

  13. Middle East

    International Nuclear Information System (INIS)

    This document summarizes in a series of tables and graphs the energy profile of Middle East: production, imports, exports, stock change and consumption of crude oil and LNG, oil products, natural gas, coal and lignite, electricity, global primary consumption and energy balance. (J.S.)

  14. Apparatus for heat treating plastic belts

    Science.gov (United States)

    Topits, A., Jr.

    1975-01-01

    Apparatus performs programed rotating, stretching/shrinking and heat treatment necessary to fabrication of high-performance plastic belts. Belts can be treated in lengths varying from 7 to 48 in., in widths up to 1 in., and in thicknesses up to approximately 0.003 in.

  15. Understanding Quaternions and the Dirac Belt Trick

    Science.gov (United States)

    Staley, Mark

    2010-01-01

    The Dirac belt trick is often employed in physics classrooms to show that a 2n rotation is not topologically equivalent to the absence of rotation whereas a 4n rotation is, mirroring a key property of quaternions and their isomorphic cousins, spinors. The belt trick can leave the student wondering if a real understanding of quaternions and spinors…

  16. Parameters affecting seat belt use in Greece.

    Science.gov (United States)

    Yannis, G; Laiou, A; Vardaki, S; Papadimitriou, E; Dragomanovits, A; Kanellaidis, G

    2011-09-01

    The objective of this research is the exploration of seat belt use in Greece and particularly the identification of the parameters affecting seat belt use in Greece. A national field survey was conducted for the analytical recording of seat belt use. A binary logistic regression model was developed, and the impact of each parameter on seat belt use in Greece was quantified. Parameters included in the model concern characteristics of car occupants (gender, age and position in the car), the type of the car and the type of the road network. The data collection revealed that in Greece, the non-use of seat belt on the urban road network was higher than on the national and rural road network and young and older men use seat belts the least. The developed model showed that travelling on a national road is negative for not wearing the seat belt. Finally, the variable with the highest impact on not wearing a seat belt is being a passenger on the back seats. PMID:21452095

  17. Radiation belt dynamics during solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G. (Geophysics Lab., Air Force Systems Command, Hanscom AFB, MA (US)); Holeman, E. (Physics Dept., Boston College, Chestnut Hill, MA (US))

    1989-12-01

    Two types of temporal variation in the radiation belts are studied using low altitude data taken onboard the DMSP F7 satellite: those associated with the solar cycle and those associated with large magnetic storm effects. Over a three-year period from 1984 to 1987 and encompassing solar minimum, the protons in the heart of the inner belt increased at a rate of approximately 6% per year. Over the same period, outer zone electron enhancements declined both in number and peak intensity. During the large magnetic storm of February 1986, following the period of peak ring current intensity, a second proton belt with energies up to 50 MeV was found at magnetic latitudes between 45{degrees} and 55{degrees}. The belt lasted for more than 100 days. The slot region between the inner and outer electron belts collapsed by the merging of the two populations and did not reform for 40 days.

  18. What controls the growth and shape of the Himalayan foreland fold-and-thrust belt?

    Science.gov (United States)

    Grujic, Djordje; Hirschmiller, John; Mallyon, Deirdre

    2014-05-01

    We provide empirical evidence for the impact of surface processes on the structure and geometry of the present-day foreland fold-and-thrust belt (FTB) of the Himalaya. We have reconstructed and analysed ten balanced cross sections distributed along the entire length of the Himalayan arc. Here, we focus on the Siwalik Group, which represents the deformed part of the foreland basin and consists of synorogenic middle Miocene to Pleistocene sediments that form the youngest and frontal part of the Himalayan orogen. Within the active foreland fold-and-thrust belt of the Himalaya, extension, strain rate, and belt morphology vary systematically from west to east. Strain rates correlate well with west-to east increases in convergence rates according to both long-term plate velocity data and GPS data, suggesting that Pliocene to Holocene shortening is externally imposed and related to plate convergence rates. Conversely, the eastward decrease in belt width corresponds to an eastward increase in rainfall rates and specific stream power. Although mass accretion rates have not been well constrained, we argue that they remain relatively constant along the FTB. We suggest that the morphology of the Himalayan FTB is controlled primarily by erosion, in accordance with the critical taper model. Surface material removal is mainly controlled through rainfall and runoff and can be expressed as specific stream power. Thus, we propose that climatically induced erosion is the principal control on Himalayan foreland fold-and-thrust belt morphology. We test this hypothesis through a series of 1D numerical models. Among the parameters controlling the form of a wedge, lithology, erodibility, and rock mechanical properties are relatively homogeneous throughout the belt. Hence, within the range of observed values in the Himalaya, we investigate the sensitivity of the shape of the Himalayan fold-and-thrust belt to the sole-out depth of the basal décollement, flux of tectonically added material

  19. Petrophysical and sedimentological characterization of the Zuata field in Orinoco Oil Belt. Venezuela

    International Nuclear Information System (INIS)

    The Zuata field is in the middle of the Jun in block in Orinoco Oil Belt and its production is handled by the district of Cabrutica which planning to develop a comprehensive reservoir model that allows leverage a correct management of hydrocarbon reserves. The purpose of this study is to generate a sedimentological and petrophysical model to know the architecture and quality of the rocks

  20. The Gould's Belt distance survey

    CERN Document Server

    Loinard, L; Torres, R M; Dzib, S; Rodriguez, L F; Boden, A F

    2011-01-01

    Very Long Baseline Interferometry (VLBI) observations can provide the position of compact radio sources with an accuracy of order 50 micro-arcseconds. This is sufficient to measure the trigonometric parallax and proper motions of any object within 500 pc of the Sun to better than a few percent. Because they are magnetically active, young stars are often associated with compact radio emission detectable using VLBI techniques. Here we will show how VLBI observations have already constrained the distance to the most often studied nearby regions of star-formation (Taurus, Ophiuchus, Orion, etc.) and have started to provide information on their internal structure and kinematics. We will then briefly describe a large project (called The Gould's Belt Distance Survey) designed to provide a detailed view of star-formation in the Solar neighborhood using VLBI observations.

  1. Binaries in the Kuiper Belt

    CERN Document Server

    Noll, K S; Chiang, E I; Margot, J L; Kern, S D; Noll, Keith S.; Grundy, William M.; Chiang, Eugene I.; Margot, Jean-Luc; Kern, Susan D.

    2007-01-01

    Binaries have played a crucial role many times in the history of modern astronomy and are doing so again in the rapidly evolving exploration of the Kuiper Belt. The large fraction of transneptunian objects that are binary or multiple, 48 such systems are now known, has been an unanticipated windfall. Separations and relative magnitudes measured in discovery images give important information on the statistical properties of the binary population that can be related to competing models of binary formation. Orbits, derived for 13 systems, provide a determination of the system mass. Masses can be used to derive densities and albedos when an independent size measurement is available. Angular momenta and relative sizes of the majority of binaries are consistent with formation by dynamical capture. The small satellites of the largest transneptunian objects, in contrast, are more likely formed from collisions. Correlations of the fraction of binaries with different dynamical populations or with other physical variabl...

  2. Strategy for replacing conveyor belts in complex haulage systems

    Energy Technology Data Exchange (ETDEWEB)

    Gladysiewicz, L.; Jurdziak, L.; Masella, J.

    1986-01-01

    Discusses service life and reliability of conveyor belts used for mine haulage in brown coal surface mining and a method for optimizing belt service life. Based on analysis of operation of 900-1,200 m long belt conveyors in the Konin surface mine, failure rates and factors that influence belt reliability were determined. Effects of joints, length of belt sections and service life of each belt section were analyzed. Formulae for determining the optimum time interval for replacing belt sections on a long belt conveyor were derived. The formulae consider cost of new belt sections, replacement cost and haulage losses associated with possible belt failure caused by excessive belt service life. The optimization procedure has been successfully tested at the Turow surface mine and power plant. 4 refs.

  3. Seat belt use law in developing countries

    Institute of Scientific and Technical Information of China (English)

    SangWanLee

    1999-01-01

    Objective:To highlight the way to successful implementation of mandantory seat belt use law in developing countries particulary where have significant increase in number or cars and subsequent increase in car occupant casualties.Methods:Literatures concerning seat belt use were reviewed and experiences of the world.Satisfactory or not,investigated.It summed up general aspects of seat belt use as well as benefits,attitude toward legislation and measures to enhance the usage.Results:Seat belt use has been proven and stood time tested as the most effective means to protect car occupants from road crash injuries.It appears to be arduous to achieve the golal of seat belt use law in developing countries. but possible via strategies appropriately leading to legislation and promotion of the belt usage.Conclusions:It is prime necessity for the government authorities to recognize the importance of seat belt use.There needs an organizational structure composed of relevant professional from both private and government sectors which is able to carry out every steps toward successful legislation and implementation:education,publicity,enforcement,evaluation and dissemination of the law's benefits.

  4. DYNAMIC RESPONSES OF VISCOELASTIC AXIALLY MOVING BELT

    Institute of Scientific and Technical Information of China (English)

    李映辉; 高庆; 蹇开林; 殷学纲

    2003-01-01

    Based on the Kelvin viscoelastic differential constitutive law and the motion equation of the axially moving belt, the nonlinear dynamic model of the viscoelastic axial moving belt was established. And then it was reduced to be a linear differential system which the analytical solutions with a constant transport velocity and with a harmonically varying transport velocity were obtained by applying Lie group transformations. According to the nonlinear dynamic model, the effects of material parameters and the steady-state velocity and the perturbed axial velocity of the belt on the dynamic responses of the belts were investigated by the research of digital simulation. The result shows: 1 ) The nonlinear vibration frequency of the belt will become small when the relocity of the belt increases. 2 ) Increasing the value of viscosity or decreasing the value of elasticity leads to a deceasing in vibration frequencies. 3 ) The most effects of the transverse amplitudes come from the frequency of the perturbed velocity when the belt moves with harmonic velocity.

  5. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  6. Computer-aided design of conveyor belts

    Energy Technology Data Exchange (ETDEWEB)

    Karolewski, B.; Pytel, J.

    1984-01-01

    Possibilities are discussed for using mathematical models of belt conveyors for development of computer-aided design of conveyors for coal mining. Examples of optimization tasks and methods for their solution using computerized simulation are analyzed. The analysis is illustrated by an algorithm used to design a starter for the drive system of a belt conveyor. Electromagnetic moment and starting current are used as optimization criteria. A simplified model of a belt conveyor is used. The model consists of an equation of motion with variable braking moment and variable moment of inertia. 3 references.

  7. Alice Walker: "The Diary of an African Nun" and Dubois Double Consciousness

    Science.gov (United States)

    Fontenot, Chester J.

    1977-01-01

    Analyzes Alice Walker's novel and notes that the plight of the African nun is that of the black intellectual or middle-class who find themselves caught between two worlds which are at once complementary and contradictory. (Author)

  8. From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives: influence of tensioner and belt characteristics

    OpenAIRE

    Manin, Lionel; Michon, Guilhem; Rémond, Didier; Dufour, Regis

    2007-01-01

    Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been u...

  9. The Stratigraphy and Lithofacies of the Paleoproterozoic Volcaniclastic Sequences in the Cape Three Points Area- Akodda section of the Southern in Ashanti Belt in the Birimian of southwest Ghana

    Science.gov (United States)

    Yoshimaru, S.; Kiyokawa, S.; Ito, T.; Ikehara, M.; Nyame, F. K.; Tetteh, G. M.

    2015-12-01

    volcaniclastic rocks in an oceanic island arc around the West African Craton. Preliminary δ13C analysis gave values of -23.7~ -36.5 ‰ for black shale occupying the middle to upper part of the whole section. The very light carbon isotope ratios suggest deposition of the black shale under highly euxinic conditions like today's Black sea.

  10. African Americans and Glaucoma

    Science.gov (United States)

    ... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't ...

  11. Age constraints of the Wassa and Benso mesothermal gold deposits, Ashanti Belt, Ghana, West Africa

    Science.gov (United States)

    Parra-Avila, Luis A.; Bourassa, Yan; Miller, John; Perrouty, Stéphane; Fiorentini, Marco L.; Campbell McCuaig, T.

    2015-12-01

    The Ashanti Belt in Ghana hosts numerous multi-million ounce gold deposits and is one of the most richly gold endowed Paleoproterozoic belts of the West African Craton. This work shows that the Wassa mineralized intrusion is part of the Sefwi Group. This unit at Wassa is strongly magnetic and show a distinctly high response in regional magnetic data sets compared to other units of equivalent age within the belt. The unit is inferred to be a lateral extension of an exposed fragment of what defines the substrate to the Tarkwa Basin sediments. The Wassa deposit, located in the eastern limb of the belt, is hosted within mafic to intermediate volcanic flows that are interbedded with minor horizons of volcaniclastics, clastic sediments. The clastic sediments include wackes and magnetite rich sedimentary layers, presumably derived from banded iron formations. The previously described sequence is intruded by syn-volcanic mafic intrusives and felsic porphyries rocks that are all part of the Birimian stratigraphy. Two new key SHRIMP II U-Pb ages were determined as part of this study: a new age of 2191 ± 6 Ma was determined on magmatic zircon grains of the Wassa porphyry host rock, which now represents the oldest known felsic intrusion hosting gold mineralization in the Ashanti Belt region. The Benso gold deposit system, which is located in the eastern limb of the Ashanti Belt approximately 38 km southwest of Wassa is hosted within a series of volcanic units intruded by mafic to intermediate units. A SHRIMP II U-Pb age of 2157 ± 5 Ma was determined from magmatic zircons obtained from a granodiorite of the G-Zone of the Benso deposit. This granodiorite is the main host rock for gold mineralization and thus the age provides an upper constraint for mineral emplacement. The newly determined ages provide an upper constraint for the gold mineralization within this region of the Ashanti Belt. They also support recent structural studies that have interpreted that the Wassa

  12. The Compositional Structure of the Asteroid Belt

    CERN Document Server

    DeMeo, Francesca E; Walsh, Kevin J; Chapman, Clark R; Binzel, Richard P

    2015-01-01

    The past decade has brought major improvements in large-scale asteroid discovery and characterization with over half a million known asteroids and over 100,000 with some measurement of physical characterization. This explosion of data has allowed us to create a new global picture of the Main Asteroid Belt. Put in context with meteorite measurements and dynamical models, a new and more complete picture of Solar System evolution has emerged. The question has changed from "What was the original compositional gradient of the Asteroid Belt?" to "What was the original compositional gradient of small bodies across the entire Solar System?" No longer is the leading theory that two belts of planetesimals are primordial, but instead those belts were formed and sculpted through evolutionary processes after Solar System formation. This article reviews the advancements on the fronts of asteroid compositional characterization, meteorite measurements, and dynamical theories in the context of the heliocentric distribution of...

  13. Handbook Timing Belts Principles, Calculations, Applications

    CERN Document Server

    Perneder, Raimund

    2012-01-01

    Timing belts offer a broad range of innovative drivetrain solutions; they allow low-backlash operation in robot systems, they are widely used in automated processes and industrial handling involving highly dynamic start-up loads, they are low-maintenance solutions for continuous operation applications, and they can guarantee exact positioning at high operating speeds. Based on his years of professional experience, the author has developed concise guidelines for the dimensioning of timing belt drives and presents proven examples from the fields of power transmission, transport and linear transfer technology. He offers definitive support for dealing with and compensating for adverse operating conditions and belt damage, as well as advice on drive optimization and guidelines for the design of drivetrain details and supporting systems. All market-standard timing belts are listed as brand neutral. Readers will discover an extensive bibliography with information on the various manufacturers and their websites. This...

  14. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  15. Two Discrete UHP and HP Metamorphic Belts in the Central Orogenic Belt, China

    Institute of Scientific and Technical Information of China (English)

    Suo Shutian; Zhong Zengqiu; Zhang Li; Zhou Hanwen; You Zhendong

    2006-01-01

    An attempt is made to confirm the existence of the two discrete UHP and HP metamorphic belts in the central orogenic belt in China. Detailed geological mapping and structural and petrological analyses of the Kanfenggou (看丰沟) and Xiangfanggou ( 香坊沟 ) slices exposed in the eastern Qinling (秦岭) orogen indicate that they experienced ultrahigh pressure and high pressure metamorphism, respectively. The former, situated in northern Qinling, contains a large volume of fine-grained coesite and quartz pseudomorphs after coesite- and microdiamond-bearing eclogite lenses, whereas the latter, located in southern Qinling, preserves the relicts of a high pressure metamorphic mineral assemblage. Based on extensive fieldwork together with compilations at the scale of the orogenic belt, and a comparison of Pb isotopic compositions between the UHP metamorphic rocks from Kanfenggou slice and the Dabie UHP metamorphic belt, we propose that there are at least two discrete ultrahigh pressure metamorphic belts with different ages and tectonic evolution within the central orogenic belt in China. The first is the South Altun-North Qaidam-North Qinling ultrahigh pressure metamorphic belt of Early Paleozoic age (~ 500-400 Ma). The Kanfenggou ultrahigh pressure slab is located at its eastern segment. The second is the well constrained Dabie ( 大别 )-Sulu ( 苏鲁 ) ultrahigh/ high pressure metamorphic belt of Triassic age (~250-220 Ma). The Xiangfanggou high pressure metamorphic slab is a westward extension of the Dabie-Sulu ultrahigh/high pressure metamorphic belt. The Pb isotopic compositions of the UHP metamorphic rocks from Kanfenggou UHP fragment in East Qinling are different from those of the UHP rocks in Dabie UHP metamorphic belt, but are consistent with those of the rocks from the Qinling rock group and Erlangping (二郎坪) rock group. The East Qinling UHP metamorphic belt does not appear to link with the Dabie-Sulu UHP metamorphic belt. These two ultrahigh

  16. African American Suicide

    Science.gov (United States)

    African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, ... 46 per 100,000. • The suicide rate for African Americans ages 10-19 was 2.98 per ...

  17. Linguistic Imperialism: African Perspectives.

    Science.gov (United States)

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  18. Seat belts, airbags and child protection devices. [previously: Seat belts and child restraint seats.

    NARCIS (Netherlands)

    2010-01-01

    In the Netherlands, the use of seat belts results in a yearly reduction of hundreds of fatalities. Seat belts reduce the risk of fatal injury by 37 to 48%, depending on the position in the car. At 50%, the effect of child protection devices is even slightly higher. When last measured (in 2010), 97%

  19. Analysis of stress distribution of timing belts by FEM; Yugen yosoho ni yoru timing belt oryoku kaiseki (belt code oryoku bunpu kaiseki hokoku)

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Y.; Tomono, K.; Takahashi, H.; Uchida, T. [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    A model of the belt analyzed by-ABAQUS (: a general nonlinear finite element program) successfully confirmed the mechanism that generates the belt cord stress. A quite good agreement between experimental and computed results for the stress distribution of the belt cord. It is found that maximum stress of the cords occurs near the root of the tooth by calculation, where the belt cords break off. 3 refs., 9 figs.

  20. Structural style of the Marathon thrust belt, West Texas

    Science.gov (United States)

    Hickman, Robert G.; Varga, Robert J.; Altany, Robert M.

    2009-09-01

    The Marathon portion of the Ouachita thrust belt consists of a highly deformed allochthonous wedge of Cambrian-Pennsylvanian slope strata (Marathon facies) that was transported to the northwest and emplaced over Pennsylvanian foredeep sediments. The foredeep strata in turn overlie early-middle Paleozoic shelfal sediments which are deformed by late Paleozoic basement-involved reverse faults. The Dugout Creek thrust is the basal thrust of the allochthon. Shortening in this sheet and overlying sheets is ˜80%. Steep imbricate faults link the Dugout Creek thrust to upper level detachments forming complex duplex zones. Progressive thrusting and shortening within the allochthon folded the upper level detachments and associated thrust sheets. The Caballos Novaculite is the most competent unit within the Marathon facies and controlled development of prominent detachment folds. Deeper imbricate sheets composed of the Late Pennsylvanian foredeep strata, and possibly early-middle Paleozoic shelfal sediments developed concurrently with emplacement of the Marathon allochthon and folded the overlying allochthon. Following termination of thrusting in the earliest Permian, subsidence and deposition shifted northward to the Delaware, Midland and Val Verde foreland basins.

  1. Discovery and Significance of Carbonate Mud Mounds from Cu-polymetallic Deposits in the Middle and Lower Yangtze Metallogenic Belt:Examples from the Wushan and Dongguashan Deposits%长江中下游成矿带铜多金属矿床中灰泥丘的发现及其意义——以武山和冬瓜山铜矿为例

    Institute of Scientific and Technical Information of China (English)

    蒋少涌; 丁清峰; 杨水源; 朱志勇; 孙明志; 孙岩; 边立曾

    2011-01-01

    Bedded sulfide orebodies occur in the Wushan and Dongguashan Cu deposits in the Middle and Lower Yangtze mineralization belt. In this study, we found a typical circular or laminated texture in the bedded sulfide ores. Based on microscopic observation of thin sections of the ore samples, carbon and oxygen isotopic analysis, and scanning electron microscope (SEM) observation, we suggested that this type of sulfide ores belongs to a mineralized kind of carbonate mud mound. The macroscopic structures of these sulfide ores are quite similar to those of cavities system of typical carbonate mud mounds, and there are also bacteria structures found in some of the ore samples with SEM analysis. Previous studies show that the carbonate mud mound generally develops in a slope setting with water depth deeper than platform. It is also shown that the occurrence of carbonate mud mound has a close relationship with sea-floor hydrothermal exhalative ore-forming processes. The conservation conditions of the carbonate mud mounds in the two copper deposits are different, in the Dongguashan Cu deposit a lot of primary exhalative sedimentary textures are preserved, bacteria structures are found, and the carbon-oxygen isotopic compositions show primary sedimentary characteristics, while those in the Wushan Cu deposit show hydrothermal altered/overprinted textures, and no bacteria structures have been found so far, the carbon-oxygen isotopic compositions also indicate a hydrothermal reworking. In summary, the discoveries of carbonate mud mounds structure sulfide ores in the Wushan and Dongguashan Cu deposits provide new evidence for the Hercynian sedimentary hydrothermal-exhalative mineralization in the Middle and Lower Yangtze metallogenic belt.%通过对长江中下游成矿带中武山铜矿和冬瓜山铜矿层状硫化物矿体的详细研究,发现了大量具有层圈状构造、层纹状构造或不规则同心环状构造的矿石.在前人研究基础

  2. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  3. Pan-African Paleostresses and Reactivation of the Eburnean Basement Complex in Southeast Ghana (West Africa

    Directory of Open Access Journals (Sweden)

    Mahaman Sani Tairou

    2012-01-01

    Full Text Available This faulting tectonics analysis concerns the southernmost segment of the Dahomeyide Orogen and the West-African craton eastern margin in southeast Ghana. The analysis of strike-slip faults in the frontal units of the Dahomeyide Belt indicates that four distinct compressive events (NE-SW, ENE-WSW to E-W, ESE-WNW to SE-NW and SE-NW to SSE-NNW originated the juxtaposition of the Pan-African Mobile Zone and the West-African craton. These paleostress systems define a clockwise rotation of the compressional axis during the structuring of the Dahomeyide Orogen (650–550 Ma. The SE-NW and SSE-NNW to N-S compressional axes in the cratonic domain and its cover (Volta Basin suggest that the reactivation of the eastern edge of the West African craton is coeval with the last stages of the Pan-African tectogenesis in southeast Ghana. An extensional episode expressed as late normal faulting is also recorded in this study. This E-W to SE-NW extension, which is particular to the southernmost part of the Dahomeyide Belt, appears to be post-Pan-African. This extension probably contributed to the formation of a major Jurassic rifting zone that originated the Central Atlantic and the Benue Trough.

  4. The Compositions of Kuiper Belt Objects

    CERN Document Server

    Brown, Michael E

    2011-01-01

    Objects in the Kuiper belt are small and far away thus difficult to study in detail even with the best telescopes available at earth. For much of the early history of the Kuiper belt, studies of the compositions of these objects were relegated to collections of moderate quality spectral and photometric data that remained difficult to interpret. Much early effort was put into simple correlations of surface colors and identifications of spectral features, but it was difficult to connect the observations to a larger understanding of the region. The last decade, however, has seen a blossoming in our understanding of the compositions of objects in the Kuiper belt. This blossoming is a product of the discoveries of larger -- and thus easier to study -- objects, continued dedication to the collection of a now quite large collection of high quality photometric and spectroscopic observations, and continued work at the laboratory and theoretical level. Today we now know of many processes which affect the surface compos...

  5. Perceptual findings on the broadway belt voice.

    Science.gov (United States)

    DeLeo LeBorgne, Wendy; Lee, Linda; Stemple, Joseph C; Bush, Heather

    2010-11-01

    The present study required raters (casting directors) to evaluate the belt voice quality of 20 musical theater majors who were proficient in the singing style referred to as belting. Two specified vocalizes and six short excerpts from the belting repertoire were used for rating purposes. The raters were asked to judge the belters on a set of seven perceptual parameters (loudness, vibrato, ring, timbre, focus, nasality, and registration breaks), and then report an overall score for these student belters. The four highest and lowest average scores were used to establish the elite and average student belters. A correlation analysis and linear regression analysis provided insight regarding which perceptual judgments correlated most highly with the elite and average scores. The present study found the perceptual ratings of vibrato and ring to be most highly correlated to the elite student belter. In addition, vibrato and ring were found to highly correlate with perceived loudness. PMID:19900789

  6. Paleostructural geomorphology of the Paleozoic central uplift belt and its constraint on the development of depositional facies in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    LIN ChangSong; YANG HaiJun; LIU JingYan; PENG Li; CAI ZhenZhong; YANG XiaoFa; YANG YongHeng

    2009-01-01

    Inclined eastward and consisting of the Hetianhe,Hetianhedong,Tazhong paleouplifts and Bachu pa-leoslope,the central paleouplift belt in the Tarim Basin was a large composite paleouplift and pa-leoslope belt with complicated palaeogeomorphic features during the Middle to early Late Ordovician.A number of paleostructural geomorphic elements have been identified in the paleouplift belt and sur-rounding areas,such as the high uplift belts,the faulted uplift platforms,the marginal slopes and slope break zones flanking the paleouplift belt,the surrounding shelf slopes or low relief ramps,the shelf slope break zones and deep basin plains.They exerted great influence on the development of paleo-geography of the basin.The marginal slopes and slope break zones flanking the uplift belt constrained the formation and deposition of the high-energy facies including reefal and shoal deposits during the Late Ordovician,which comprise the major reservoirs of the Lower Paleozoic in the basin.Toward the end of the Ordovician,the Tazhong paleouplift hinged westward and became a westward-dipped nose as the southeastern margin of the basin was strongly compressed and uplifted.The tec-tono-paleogeomorphic framework of the central northern basin during the Early Silurian and the Late Devonian to Early Carboniferous changed remarkably in topography from the initial low in east and high in west to high in northeast and low in southwest.The major paleogeomorphic elements devel-oped in these periods included the strong eroded uplift high,the uplift marginal slope,the gentle ramp of the depression margin and the depression belt.The sandstones of the Iowstand and the early transgressive systems tracts were deposited along the uplift marginal slopes and the gentle ramps of the depressions comprise the prolific reservoirs in the basin.The study indicates that the distribution patterns of the unconformities within the basin are closely related to the paleogeomorphic features and evolution of the

  7. Composite Microdiscs with a Magnetic Belt

    DEFF Research Database (Denmark)

    Knaapila, Matti; Høyer, Henrik; Helgesen, Geir

    2015-01-01

    We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 mu m) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 mu m) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles......, the spontaneous aggregation of composite particles is suppressed when dispersed into liquid, which is attributed to the increased particle size, reduced magnetic susceptibility, and the shape of the magnetic domain distribution within the particles (spherical versus a belt). When the composite particles...

  8. The Black Black Woman and the Black Middle Class.

    Science.gov (United States)

    Jeffers, Trellie

    1981-01-01

    Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

  9. Is There a Relationship between Family Structure and Substance Use among Public Middle School Students?

    Science.gov (United States)

    Paxton, Raheem J.; Valois, Robert F.; Drane, J. Wanzer

    2007-01-01

    We investigated the relationship between family structure and substance use in a sample of 2,138 public middle school students in a southern state. The CDC Middle School Youth Risk Behavior Survey was utilized and adjusted logistic regression models were created separately for four race/gender categories (African American females/males, and…

  10. Psychometric evaluations of the efficacy expectations and Outcome Expectations for Exercise Scales in African American women.

    Science.gov (United States)

    Murrock, Carolyn J; Gary, Faye

    2014-01-01

    This secondary analysis tested the reliability and validity of the Self-Efficacy for Exercise (SEE) and the Outcome Expectations for Exercise (OEE) scales in 126 community dwelling, middle aged African American women. Social Cognitive Theory postulates self-efficacy is behavior age, gender and culture specific. Therefore, it is important to determine ifself-efficacy scales developed and tested in older Caucasian female adults are reliable and valid in middle aged, minority women. Cronbach's alpha and construct validity using hypothesis testing and confirmatory factor analysis supported the reliability and validity of the SEE and OEE scales in community dwelling, middle aged African American women. PMID:25612395

  11. PALEOMAGNETISM OF SILURIAN AND DEVONIAN VOLCANICS FROM THE CHINGIZ ISLAND ARC, KAZAKHSTAN, AND ITS BEARING ON TECTONIC EVOLUTION OF THE URAL-MONGOL BELT

    Directory of Open Access Journals (Sweden)

    Natalia M. Levashova

    2015-09-01

    Full Text Available The tectonic and paleogeographic evolution of the Ural-Mongol belt between the cratons of Baltica, Siberia, and Tarim is the key to the formation of the Eurasian supercontinent during Paleozoic time, but the views on this complicated process remain very disparate and sometimes controversial. Three volcanic formations of the Middle Silurian, LowertoMiddle Devonian and Middle Devonian age from the southwestern boundary of the Chingiz Range (NE Kazakhstan yields what are interpreted as primary paleomagnetic directions that help clarify the evolution of the belt. A singlepolarity characteristic component in midSilurian andesites yields a positive intraformational conglomerate test, whereas dualpolarity prefolding components are isolated from the two Devonian collections. These new data were evaluated together with previously published paleomagnetic results from Paleozoic rocks in the Chingiz Range, and allow us to establish with confidence the hemisphere in which the area was located at a given time. We conclude that NE Kazakhstan was steadily moving northward crossing the equator in Silurian time. These new paleomagnetic data from the Chingiz range also agree with and reinforce the hypothesis that the strongly curved volcanic belts of Kazakhstan underwent oroclinal bending between Middle Devonian and Late Carboniferous time. A comparison of the Chingiz paleolatitudes with those of Siberia shows similarities between the northward motion and rotational history of the Chingiz unit and those of Siberia, which imposes important constraints on the evolving paleogeography of the Ural-Mongol belt.

  12. Two stages of deformation and fluid migration in the central Brooks Range fold-and-thrust belt

    Science.gov (United States)

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.; Shelton, Kevin L.; Underwood, Michael B.

    2004-01-01

    The Brooks Range is a north-directed fold and thrust belt that forms the southern boundary of the North Slope petroleum province in northern Alaska. Field-based studies have long recognized that large-magnitude, thin-skinned folding and thrusting in the Brooks Range occurred during arc-continent collision in the Middle Jurassic to Early Cretaceous (Neocomian). Folds and thrusts, however, also deform middle and Upper Cretaceous strata of the Colville foreland basin and thus record a younger phase of deformation that apatite fission-track data have shown to occur primarily during the early Tertiary (~60 and ~45 Ma). A structural and kinematic model that reconciles these observations is critical to understanding the petroleum system of the Brooks Range fold and thrust belt.

  13. Saturn Neutron Exosphere as Source for Inner and Innermost Radiation Belts

    Science.gov (United States)

    Cooper, John; Lipatov, Alexander; Sittler, Edward; Sturner, Steven

    2011-01-01

    Energetic proton and electron measurements by the ongoing Cassini orbiter mission are expanding our knowledge of the highest energy components of the Saturn magnetosphere in the inner radiation belt region after the initial discoveries of these belts by the Pioneer 11 and Voyager 2 missions. Saturn has a neutron exosphere that extends throughout the magnetosphere from the cosmic ray albedo neutron source at the planetary main rings and atmosphere. The neutrons emitted from these sources at energies respectively above 4 and 8 eV escape the Saturn system, while those at lower energies are gravitationally bound. The neutrons undergo beta decay in average times of about 1000 seconds to provide distributed sources of protons and electrons throughout Saturn's magnetosphere with highest injection rates close to the Saturn and ring sources. The competing radiation belt source for energetic electrons is rapid inward diffusion and acceleration of electrons from the middle magnetosphere and beyond. Minimal losses during diffusive transport across the moon orbits, e.g. of Mimas and Enceladus, and local time asymmetries in electron intensity, suggest that drift resonance effects preferentially boost the diffusion rates of electrons from both sources. Energy dependences of longitudinal gradient-curvature drift speeds relative to the icy moons are likely responsible for hemispheric differences (e.g., Mimas, Tethys) in composition and thermal properties as at least partly produced by radiolytic processes. A continuing mystery is the similar radial profiles of lower energy (neutron decay, but perhaps alternatively from atmospheric albedo, or else all protons from diverse distributed sources are similarly affected by losses at the moon' orbits, e.g. because the proton diffusion rates are extremely low. Enceladus cryovolcanism, and radiolytic processing elsewhere on the icy moon and ring surfaces, are additional sources of protons via ionization and charge exchange from breakup of

  14. Geochemical and zircon U-Pb dating analysis of metamagmatic rocks from the Yuli belt in Taiwan

    Science.gov (United States)

    Hung, Chia-Chia

    2016-04-01

    The Tananao Schist Complex of the oldest rocks in Taiwan is exposed at the eastern limb of Backbone Range. Based on the lithologic and metamorphic characteristics, the complex can be divided into the Tailuko and Yuli belts. The Tailuko belt consists of marble, gneiss, and subordinate scattered metabasite; the Yuli belt is composed of greenschist, serpentinite, meta-tuff, meta-gabbro, metabasite, and glaucophane-schist blocks which enclosed by spotted schist of the host rocks. The metamorphic belts were inferred as a Mesozoic mélange. It's still controversial due to the difficulty of analyzing metamorphic rocks. In this study, we focus on the zircon U-Pb dating, geochemistry, and petrographic analysis of spotted schist, metabasite, meta-gabbro, and meta-tuff in order to constrain the formation and crystallization ages and interpret its tectonic setting. Based on zircon U-Pb dating, the host rocks of spotted schist and the exotic blocks of meta-tuff, meta-gabbro (the peak age of 14.4, 15.8, and 16.7 Ma), and metabasite occurred at Miocene. Geochemical characteristics for metabasite and meta-gabbro blocks show Ta-Nd-Ti depletion and LREE depletion in spidergram occurring volcanic arc and N-MORB type affinities, respectively. Results as above mentioned, we suggest that the metamagmatic rocks in the Yuli belt occur within a mélange during the Eurasia continental margin subduction at the Middle-Late Miocene.

  15. Albedo Properties of Main Belt Asteroids Based on the Infrared All-Sky Survey of the Astronomical Satellite AKARI

    CERN Document Server

    Usui, Fumihiko; Hasegawa, Sunao; Ishiguro, Masateru; Kuroda, Daisuke; Mueller, Thomas G; Ootsubo, Takafumi; Matsuhara, Hideo

    2012-01-01

    We present an analysis of the albedo properties of main belt asteroids detected by the All-Sky Survey of the infrared satellite AKARI. The characteristics of 5120 asteroids detected by the survey, including their sizes and albedos, were cataloged in the Asteroid Catalog Using AKARI (AcuA). Size and albedo measurements were based on the Standard Thermal Model, using inputs of infrared fluxes and absolute magnitudes. Main belt asteroids, which account for 4722 of the 5120 AcuA asteroids, have semimajor axes of 2.06 to 3.27 AU. AcuA provides a complete data set of all main belt asteroids brighter than the absolute magnitude of H 20 km. We confirmed that the albedo distribution of the main belt asteroids is strongly bimodal as was already known from the past observations, and that the bimodal distribution occurs not only in the total population, but also within inner, middle, and outer regions of the main belt. We found that the small asteroids have much more variety in albedo than the large asteroids. In spite ...

  16. Archaean Crustal Growth, Proterozoic Terrane Amalgamation and the Pan-African Orogeny, as Recorded in the NE African Sedimentary Record.

    Science.gov (United States)

    Najman, Y.; Fielding, L.; Millar, I.; Butterworth, P.; Andò, S.; Padoan, M.; Barfod, D. N.; Kneller, B. C.

    2015-12-01

    The cratons of Central Africa are formed of various blocks of Archaean and Palaeoproterozoic crust, flanked or truncated by Palaeoproterozoic to Mesoproterozoic orogenic belts. The geology of east Africa has largely been shaped by the events of the Pan-African Orogeny when east and west Gondwana collided to form 'Greater Gondwana' at the end of the Neoproterozoic. The Pan-African orogeny in NE Africa involved the collision of Archaean cratons and the Saharan Metacraton with the Arabian Nubian Shield, a terrane comprising Neoproterozoic juvenile oceanic island arcs. Phanerozoic cover sedimentary rocks, eroded from the Pan-African orogenies, blanket much of NE Africa. Detrital data from these Phanerozoic cover sedimentary rocks, and modern rivers draining both the cover the basement, provide a wealth of information on basement evolution, of particular relevance for regions where the basement itself is poorly exposed due to ancient or modern sedimentary cover. From samples collected in Uganda, Ethiopia, Sudan and Egypt, we provide combined U-Pb and Hf-isotope zircon, U-Pb rutile and Ar-Ar mica datasets, heavy mineral analyses, and bulk trace element data, from Archaean basement, Phanerozoic cover and modern river sediment from the Nile and its tributaries to document the evolution of the North African crust. The data document early crust-forming events in the Congo Craton and Sahara Metacraton, phased development of the Arabian Nubian Shield culminating in the Neoproterozoic assembly of Gondwana during the Pan African Orogeny, and the orogen's subsequent erosion, with deposition of voluminous Phanerozoic cover.

  17. The thrust belts of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, F.C.

    1993-08-01

    Most of the Basin and Range physiographic province of western North America is now believed to be part of the overthrust. The more obvious overthrust belt along the eastern edge of the Basin and Range Province is named the Sevier orogenic belt, where older rocks are observed thrust onto younger rocks. More detailed surface geological mapping, plus deep multiple-fold geophysical work and many oil and gas wildcat wells, have confirmed an east-vergent shortened and stacked sequence is present in many places in the Basin and Range. This western compressive deformed area in east central Nevada is now named the Elko orogenic belt by the U.S. Geological Survey. This older compressed Elko orogenic belt started forming approximately 250 m.y. ago when the North American plate started to move west as the Pangaea supercontinent started to fragment. The North American plate moved west under the sediments of the Miogeocline that were also moving west. Surface-formed highlands and oceanic island arcs on the west edge of the North American plate restricted the westward movement of the sediments in the Miogeocline, causing east-vergent ramp thrusts to form above the westward-moving North American plate. The flat, eastward-up-cutting thrust assemblages moved on the detachment surfaces.

  18. Design aspects of multiple driven belt conveyors

    NARCIS (Netherlands)

    Nuttall, A.J.G.

    2007-01-01

    Worldwide belt conveyors are used to transport a great variety of bulk solid materials. The desire to carry higher tonnages over longer distances and more diverse routes, while keeping exploitation costs as low as possible, has fuelled many technological advances. An interesting development in the r

  19. Imaging Jupiter Radiation Belts At Low Frequencies

    Science.gov (United States)

    Girard, J. N.; de Pater, I.; Zarka, P.; Santos-Costa, D.; Sault, R.; Hess, S.; Cecconi, B.; Fender, R.; Pewg, Lofar

    2014-04-01

    The ultra-relativistic electrons, trapped in the inner radiation belts of Jupiter, generates a strong synchrotron radio emission (historically known as the jovian decimeter radiation (DIM)) which is beamed, polarized (~20% linear, ~1% circular) and broadband. It has been extensively observed by radio telescopes/ probes and imaged by radio interferometers over a wide frequency spectrum (from >300 MHz up to 22 GHz). This extended emission presents two main emission peaks constantly located on both sides of the planet close to the magnetic plane. High latitude emissions were also regularly observed at particular frequencies, times and in particular observational configurations. This region of the magnetosphere is "frozen" due to the strong magnetic field (~4.2 G as the equator) and therefore is forced to rotate at the planetary period (T≈9h55m). Due to the tilt (~ 10o) between the spin axis of the planet and the magnetic axis (which can be seen as dipolar in first approximation), the belts and the associated radio emission wobble around the planet center. The analysis of the flux at different frequencies highlighted spatial, temporal and spectral variabilities which origins are now partly understood. The emission varies at different time scales (short-time variations of hours to long-term variation over decades) due to the combination of visibility effect (wobbling, beaming, position of the observer in the magnetic rotating reference frame) [1], [2] and intrinsic local variations (interaction between relativistic electrons and satellites/dust, delayed effect of the solar wind ram pressure, impacts events) [3], [4], [5]. A complete framework is necessary to fully understand the source, loss and transport processes of the electrons originating from outside the belt, migrating by inward diffusion and populating the inner region of the magnetosphere. Only a few and unresolved measurements were made below 300 MHz and the nonsystematic observation of this radio emission

  20. Keeping African Masks Real

    Science.gov (United States)

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  1. African agricultural trade

    DEFF Research Database (Denmark)

    Jensen, Hans Grinsted; Sandrey, Ron

    2015-01-01

    This article starts with a profile of African agricultural trade. Using the pre-release version 9.2 of the GTAP database, we then show that the results for tariff elimination on intra-African trade are promising, but these tariff barriers are not as significant as the various trade-related barriers...

  2. African Literature as Celebration.

    Science.gov (United States)

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and dignity. (AF)

  3. Empowering African States

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China helps bring lasting peace and stability to Africa African think tanks expressed a high opinion of China’s role in helping build African peace and security at the first meeting of the China-Africa Think Tanks Forum. The

  4. African American men's perspectives on promoting physical activity: "We're not that difficult to figure out!".

    Science.gov (United States)

    Friedman, Daniela B; Hooker, Steven P; Wilcox, Sara; Burroughs, Ericka L; Rheaume, Carol E

    2012-01-01

    African American men report poorer health than do White men and have significantly greater odds for developing chronic diseases partly because of limited physical activity. Understanding how to encourage healthy behaviors among African American men will be critical in the development of effective physical activity messages and programs. Guided by principles of cultural sensitivity and social marketing, this research examined middle-aged and older African American men's recommended strategies for promoting physical activity to African American men of their age. The authors report results from 49 interviews conducted with middle-aged (45-64 years) and older (65-84 years) African American men in South Carolina. Four groups of African American men were recruited: middle-aged active men (n = 17), middle-aged inactive men (n = 12), older active men (n = 10), older inactive men (n = 10). Themes related to marketing and recruitment strategies, message content, and spokesperson characteristics emerged and differed by age and physical activity level. Recommended marketing strategies included word of mouth; use of mass media; partnering with churches, businesses, and fraternities; strategic placement of messages; culturally appropriate message framing; and careful attention to selection of program spokespersons. Findings will help in the marketing, design, implementation, and evaluation of culturally appropriate interventions to encourage physical activity among middle-aged and older African American men in the South. PMID:22808914

  5. Sedimentary features and exploration targets of Middle Permian reservoirs in the SW Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guoming Xu

    2015-11-01

    Full Text Available The exploration direction and targets for the large-scale Middle Permian gas reservoirs in the Sichuan Basin are hot spots and challenges in current exploration researches. The exploration successes of large gas field of Cambrian Longwangmiao Formation in Gaoshiti-Moxi region, Central Sichuan Basin, indicated that prospective sedimentary facies belt was the basis for the formation of large gas fields. In this paper, based on seismic data, outcrop data and drilling data, the tectonic framework and sedimentary features of the Middle Permian in the SW Sichuan Basin were comprehensively studied. The following conclusions were reached from the perspective of sedimentary facies control: (1 during the Middle Permian, this region was in shallow water gentle slope belts with high energy, where thick reef flat facies were deposited; (2 the basement was uplifted during Middle Permian, resulting in the unconformity weathering crust at the top of Maokou Formation due to erosion; the SW Sichuan Basin was located in the karst slope belt, where epigenic karstification was intense; and (3 reef flat deposits superimposed by karst weathering crust was favorable for the formation of large-scale reef flat karst reservoirs. Based on the combination of the resources conditions and hydrocarbon accumulation conditions in this region, it was pointed out that the Middle Permian has great potential of large-scale reef flat karst gas reservoir due to its advantageous geological conditions; the Middle Permian traps with good hydrocarbon accumulation conditions were developed in the Longmen Mountain front closed structural belt in the SW Sichuan Basin and Western Sichuan Basin depression slope belt, which are favorable targets for large-scale reef flat karst reservoirs.

  6. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    Science.gov (United States)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  7. Detecting Extrasolar Asteroid Belts Through Their Microlensing Signatures

    CERN Document Server

    Lake, Ethan; Dong, Subo

    2016-01-01

    We propose that extrasolar asteroid belts can be detected through their gravitational microlensing signatures. Asteroid belt + star lens systems create so-called "pseudo-caustics", regions in the source plane where the magnification exhibits a finite but discontinuous jump. These features allow such systems to generate distinctive microlensing light curves across a wide region of belt parameter space and possess remarkably large lensing cross-sections. Sample light curves for a range of asteroid belt parameters are presented. In the near future, space-based microlensing surveys (e.g., WFIRST) may be able to discover extrasolar asteroid belts with masses of the order of $0.1 M_{\\oplus}$.

  8. Seat Belt Use Among Adult Workers - 21 States, 2013.

    Science.gov (United States)

    Boal, Winifred L; Li, Jia; Rodriguez-Acosta, Rosa L

    2016-01-01

    Roadway incidents involving motorized vehicles accounted for 24% of fatal occupational injuries in the United States during 2013 and were the leading cause of fatal injuries among workers.* In 2013, workers' compensation costs for serious, nonfatal injuries among work-related roadway incidents involving motorized land vehicles were estimated at $2.96 billion.(†) Seat belt use is a proven method to reduce injuries to motor vehicle occupants (1). Use of lap/shoulder seat belts reduces the risk for fatal injuries to front seat occupants of cars by 45% and the risk to light truck occupants by 60%.(§) To characterize seat belt use among adult workers by occupational group, CDC analyzed data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS) and found that not always using a seat belt was significantly associated with occupational group after controlling for factors known to influence seat belt use. Occupational groups with the highest prevalences of not always using a seat belt included construction and extraction; farming, fishing, and forestry; and installation, maintenance, and repair. To increase seat belt use among persons currently employed, states can enact and enforce primary seat belt laws, employers can set and enforce safety policies requiring seat belt use by all vehicle occupants, and seat belt safety advocates can target interventions to workers in occupational groups with lower reported seat belt use. PMID:27309488

  9. LOAD DISTRIBUTION ON DRUMS OF DOUBLE DRIVE BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    薛河; 苏清祖; 马胜利

    1999-01-01

    The double drum drive is widely used on the mine belt conveyor, which are divided the rigid connected double drums and separately driving double drums according to connected method of two drums. Because of the change of real work condition, the load distribution is changed on the two drive drums, which may produce a slippage between a drum and belt. Slippage may intensify the wear of the drum, and sometimes causing the fire of the belt. This restricts the development toward narrow belt, high velocity and large power of belt conveyor. In this paper, the factors affecting the load distribution of two drums of double drum belt conveyor are'systematically analyzed and some computing formulas derived, by these formulas, the actual load distribution onthe two drums of rigid connected or separately driving belt conveyor can be separately calculated. These formulas also can be as the theory base for adjusting the driving force of two drums.

  10. African American Diaspora

    Directory of Open Access Journals (Sweden)

    Angela Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. With regard to all historic migrations (forced and voluntary, the African Union defined the African diaspora as "[consisting] of people of African origin living outside the continent, irrespective of their citizenship and nationality and who are willing to contribute to the development of the continent and the building of the African Union." Its constitutive act declares that it shall "invite and encourage the full participation of the African diaspora as an important part of our continent, in the building of the African Union." Keywords: literature concepts, African American abstracts

  11. Geology and Genesis of Peraluminous Granites in East Tianshan Upper Paleozoic Island Arc Belt

    Institute of Scientific and Technical Information of China (English)

    顾连兴; 严正富; 等

    1996-01-01

    A peraluminous granite belt occurs along the connecting zone between the Turpan Hami Precambrian block and the Upper Paleozoic island arc belt.Muscovite granite and twomica granite are the essential lithological components of that belt.All the potassium feldspars in these granites are microcline.Heavy minerals are dominated by magnetite,SiO2 contents of these granites are greater than 73% with most of the A/NKC values greater than 1,1,norma tive corundum values greater than 1 Plots of CIPW norms in the (Al-K-Na) Ca(Fe2++Mg) diagran are mostly situated in the plagioclase cordierite-muscovite region.The rocks are characterized by very low contents of minor elements and ∑REE with strong Eu depletion δ18 O values between 6.6‰and 7.0‰,Rb-Sr isochron age of 260.2±6.2Ma and an initial 87Sr/86 Sr ration of 0.7052,These granites might have been produced by partial melting of moderately acidic volcanites and low-maturity sediments in the basement sequences and could be genetically connected with the southware A-type subduction of the Turpan-Hami block following the closure of the Middle Carboniferous back-arc basin.

  12. Morpho-structure and sedimentology of the Holocene Ebro prodelta mud belt (northwestern Mediterranean Sea)

    Science.gov (United States)

    Diaz, J.I.; Palanques, A.; Nelson, C.H.; Guillen, J.

    1996-01-01

    The Ebro "mud belt" is a Holocene prodeltaic deposit which has developed around, and southwestward from, the present Ebro Delta plain, covering most of the inner and middle Ebro continental shelf. Seismic-reflection profiles of this mud belt exhibit a complex sigmoid-oblique configuration. Top-set strata dip gently seaward to the 20 m isobath, and overly the fore-set beds which are exposed in up to 40-60 m water depth. Top-set and fore-set beds have mostly parallel and high continuity reflectors. Thin, acoustically transparent bottom-set beds are present at the base of the fore-set beds and extend to the distal edge of the prodelta (60-80 m water depth), where they overly relict transgressive sand deposits. There is no evidence of mass movement. The suspended load discharged by the river is mainly transported alongshelf by advective processes. This dynamics produces thin clinoform deposits that extend alongshelf for tens of kilometres. Mud belt deposition began about 10,000-11,000 years BP. Accumulation rate ranges from less than 0.5 mm y-1 on the seaward and southern edges of the deposit to about 2.5 mm y-1 near the present river mouth. Copyright ?? 1995 Elsevier Science Ltd. All rights reserved.

  13. African Peacekeepers in Africa

    DEFF Research Database (Denmark)

    Emmanuel, Nikolas G.

    2015-01-01

    peacekeeping operations in the region. It is important to add that the international community has frequently tried to facilitate the deployment of African armed forces with aid and training. From this reality, the following study goes beyond the current literature by focusing on the international factors...... behind African participation in United Nations (UN) peacekeeping operations in Africa. In doing so, this research focuses on US military aid and foreign troop training from 2002 to 2012, and its impact on African deployments into UN peacekeeping missions in Africa. As can be expected, such third...

  14. Reading the African context

    OpenAIRE

    Musonda Bwalya

    2012-01-01

    There is so much alienation, pain and suffering in our today�s world. In this vein, African Christianity, a voice amongst many voices, should seek to be a transformational religion for the whole of life, affecting all facets of human life towards a fuller life of all in Africa. This article sought to highlight and point to some of the major societal challenges in the African context which African Christianity, as a life-affirming religion, should continue to embrace, re-embrace and engag...

  15. Geometry and Kinematics of the Lamu Basin Deep-Water Fold-and-Thrust Belt (East Africa)

    Science.gov (United States)

    Barchi, Massimiliano R.; Cruciani, Francesco; Porreca, Massimiliano

    2016-04-01

    Even if most thin-skinned fold-and-thrust belt are generated at convergent plate boundaries, in the last decades advances in seismic exploration and acquisition of large datasets have shown that they are also notably widespread along continental passive margins, driven by gravity processes in deep-water areas. In this study a composite set of modern and vintage reprocessed seismic reflection profiles is used to investigate the internal structure and kinematic evolution of the Lamu Basin Deep-Water Fold-and-Trust Belt (DW-FTB). The Lamu Basin is an example of giant-scale, gravity driven compressional belt developed in Late Cretaceous-Early Tertiary along a still poorly explored sector of the East-African continental margin, at the Kenya-Somalia border. The compressional domain extends longitudinally for more than 450 km, is up to 180 km wide and shows remarkable structural complexity both along strike and along dip. The external part is dominated by ocean-verging imbricate thrusts, above a gently landward-dipping basal detachment. The internal part is characterised by almost symmetrical detachment folds and double verging structures, sustaining bowl-shaped syn-tectonic basins. Here the basal detachment surface is almost flat. The mean fold wavelength displays a progressive landward increase, from 2.5 km, at the toe of the belt, to about 10 km. This structural variability is thought to be related to the lateral variation of the section under shortening and particularly to the different thickness of the Early Cretaceous shaly unit involved in the deformations, increasing landward from about 400 m to more than 1 km. Through the sequential restoration of regional cross-sections, we evaluated that the northern portion of the thrust belt experienced a shortening of almost 50 km (corresponding to 20%), with a shortening rate (during the Late Cretaceous-Paleocene main event) of about 3.5 mm/yr. Under many respects, the dimensions and internal structure of this thrust belt

  16. Capitalism and African business cultures

    OpenAIRE

    Taylor, Scott D.

    2014-01-01

    Scholars and practitioners once commonly linked 'African culture' to a distinctive 'African capitalism', at odds with genuine capitalism and the demands of modern business. Yet contemporary African business cultures reveal that a capitalist ethos has taken hold within both state and society. The success and visibility of an emergent, and celebrated, class of African big business reveals that business and profit are culturally acceptable. Existing theories of African capitalism are ill-equippe...

  17. Alien Asteroid Belt Compared to our Own

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: Band of Light Comparison This artist's concept illustrates what the night sky might look like from a hypothetical alien planet in a star system with an asteroid belt 25 times as massive as the one in our own solar system (alien system above, ours below; see Figure 1). NASA's Spitzer Space Telescope found evidence for such a belt around the nearby star called HD 69830, when its infrared eyes spotted dust, presumably from asteroids banging together. The telescope did not find any evidence for a planet in the system, but astronomers speculate one or more may be present. The movie begins at dusk on the imaginary world, when HD 69830, like our Sun, has begun to set over the horizon. Time is sped up to show the onset of night and the appearance of a brilliant band of light. This light comes from dust in a massive asteroid belt, which scatters sunlight. In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the 'false dawn,' this light appears as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light in both pictures.) In contrast, the zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the Milky Way.

  18. Middle Ear Infections

    Science.gov (United States)

    ... Issues Listen Español Text Size Email Print Share Middle Ear Infections Page Content Article Body What are ... serious illness. What if a child with a middle ear infection is in great pain and discomfort? ...

  19. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  20. Araguaia fold belt, new geochronological data

    International Nuclear Information System (INIS)

    The northern part of the Araguaia Fold Belt (AFB) outcrops in a N-S direction for about 400 km in the state of Tocantins. Dome-like structures occur in this fold belt also in a N-S direction. Both deformation and metamorphism increase from the West to the East. The basement of the AFB consist of Colmeia complex and Cantao gneiss, which crop out mainly in the core of the dome-like structures. The supracrustals rocks of the fold belt belongs to the Baixo Araguaia supergroup which is divided into the lower Estrondo group and the upper Tocantins group. Preliminary Sm-Nd data from the Colmeia complex (Grota Rica dome) gave Archean model ages of 2.8 Ga (TNd sub(DM)) while Rb-Sr data in the same rocks give an age of 2530 ± 200 Ma. In the others dome-like structures, the Rb-Sr systematics gave ages for the Colmeia a complex of 2239 ± 47 Ma (Colmeia structure) and 1972 ± 46 Ma (Lontra structure). These younger ages are believed to represent partial to total isotopic resetting of the Rb-Sr system during the Transamazonian Event. The Rb-Sr studies of the Cantao gneiss gave an age of 1774 ± 31 Ma. (author)

  1. Seat belt use during pregnancy in Iran: attitudes and practices

    Institute of Scientific and Technical Information of China (English)

    Mojgan Karbakhsh; Zahra Ershadi; Ali Khaji; Fatemeh Rahimi-Sharbaf

    2010-01-01

    Objective: Seat belt use during pregnancy reduces injury to the mother and her fetus. During recent years, the use of seat belts has been mandated by law in Iran. The purpose of this study was to determine the attitudes and practices of pregnant women regarding seat belt use.Methods: In this cross-sectional study, we asked 335 pregnant women at a hospital-based prenatal care clinic on the use of safety belt before and during pregnancy. SPSS version 13.0 was used for data analysis.Results: The mean age of study subjects was 27.3 years±5.3 years with the median of 27 years. Compared with the seat belt use before pregnancy, no change was detected in 48.7% of the women; seat belt use had increased in 17.5 %of them and decreased in 33.8 %. Eighty-one percent of women knew the correct placing of both lap belt and shoulder belt. Only 4% of women had received education on proper restraint use during pregnancy.Conclusions: The prevalence of seat belt use during pregnancy is lower than reports which are mostly from developed nations. The fact that about one-third of women have decreased their seat belt usage during pregnancy highlights the importance of education of mothers on this topic.

  2. Middle Ear Infections (For Parents)

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Middle Ear Infections KidsHealth > For Parents > Middle Ear Infections ... eventually leading to an ear infection. continue About Middle Ear Infections Inflammation in the middle ear area ...

  3. The scramble for Africans: demography, globalisation and Africa’s informal labour markets

    OpenAIRE

    Meagher, Kate

    2016-01-01

    Images of an 'African Boom' have presented us with labour markets full of dynamic potential: a declining dependency ratio, low levels of unemployment, and a vibrant middle class. This buoyant view of African labour markets conceals a less encouraging reality of catastrophic youth unemployment and expanding informality, creating a 'youth bulge' that is more of a threat than an opportunity. How does the continent with the largest share of informal labour in the world become a beacon of prosperi...

  4. Suspended particulate layers and internal waves over the southern Monterey Bay continental shelf: an important control on shelf mud belts?

    Science.gov (United States)

    Cheriton, Olivia M.; McPhee-Shaw, Erika E.; Shaw, William J.; Stanton, Timothy P.; Bellingham, James G.; Storlazzi, Curt D.

    2014-01-01

    Physical and optical measurements taken over the mud belt on the southern continental shelf of Monterey Bay, California documented the frequent occurrence of suspended particulate matter features, the majority of which were detached from the seafloor, centered 9–33 m above the bed. In fall 2011, an automated profiling mooring and fixed instrumentation, including a thermistor chain and upward-looking acoustic Doppler current profiler, were deployed at 70 m depth for 5 weeks, and from 12 to 16 October a long-range autonomous underwater vehicle performed across-shelf transects. Individual SPM events were uncorrelated with local bed shear stress caused by surface waves and bottom currents. Nearly half of all observed SPM layers occurred during 1 week of the study, 9–16 October 2011, and were advected past the fixed profiling mooring by the onshore phase of semidiurnal internal tide bottom currents. At the start of the 9–16 October period, we observed intense near-bed vertical velocities capable of lifting particulates into the middle of the water column. This “updraft” event appears to have been associated with nonlinear adjustment of high-amplitude internal tides over the mid and outer shelf. These findings suggest that nonlinear internal tidal motions can erode material over the outer shelf and that, once suspended, this SPM can then be transported shoreward to the middle and shallow sections of the mud belt. This represents a fundamental broadening of our understanding of how shelf mud belts may be built up and sustained.

  5. Health Monitoring for Coated Steel Belts in an Elevator System

    OpenAIRE

    Yimei Mao; Zuoying Huang; Guiyun Tian; Hui Zhao; Huaming Lei

    2012-01-01

    This paper presents a method of health monitoring for coated steel belts in an elevator system by measuring the electrical resistance of the ropes embedded in the belt. A model on resistance change caused by fretting wear and stress fatigue has been established. Temperature and reciprocating cycles are also taken into consideration when determining the potential strength degradation of the belts. It is proved by experiments that the method could effectively estimate the health degradation of ...

  6. Modal analysis of coupled vibration of belt drive systems

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-jun; CHEN Li-qun

    2008-01-01

    The modal method is applied to analyze coupled vibration of belt drive systems. A belt drive system is a hybrid system consisting of continuous belts modeled as strings as well as discrete pulleys and a tensioner arm. The characteristic equation of the system is derived from the governing equation. Numerical results demenstrate the effects of the transport speed and the initial tension on natural frequencies.

  7. Health Monitoring for Coated Steel Belts in an Elevator System

    Directory of Open Access Journals (Sweden)

    Huaming Lei

    2012-01-01

    Full Text Available This paper presents a method of health monitoring for coated steel belts in an elevator system by measuring the electrical resistance of the ropes embedded in the belt. A model on resistance change caused by fretting wear and stress fatigue has been established. Temperature and reciprocating cycles are also taken into consideration when determining the potential strength degradation of the belts. It is proved by experiments that the method could effectively estimate the health degradation of the most dangerous section as well as other ones along the whole belts.

  8. Mental illness and lost income among adult South Africans

    OpenAIRE

    Lund, Crick; Myer, Landon; Dan J Stein; Williams, David R.; Flisher, Alan J

    2012-01-01

    Purpose Little is known regarding the links between mental disorder and lost income in low- and middle-income countries. The purpose of this study was to investigate the association between mental disorder and lost income in the first nationally representative psychiatric epidemiology survey in South Africa. Methods A probability sample of South African adults was administered the World Health Organization Composite International Diagnostic Interview schedule to assess the presence of mental ...

  9. CHAOTIC BELT PHENOMENA IN NONLINEAR ELASTIC BEAM

    Institute of Scientific and Technical Information of China (English)

    张年梅; 杨桂通

    2003-01-01

    The chaotic motions of axial compressed nonlinear elastic beam subjected totransverse load were studied. The damping force in the system is nonlinear. Consideringmaterial and geometric nonlinearity, nonlinear governing equation of the system wasderived. By use of nonlinear Galerkin method, differential dynamic system was set up.Melnikov method was used to analyze the characters of the system. The results showed thatchaos may occur in the system when the load parameters P0 and f satisfy some conditions.The zone of chaotic motion was belted. The route from subharmonic bifurcation to chaoswas analyzed. The critical conditions that chaos occurs were determined.

  10. Dust bands in the asteroid belt

    Science.gov (United States)

    Sykes, Mark V.; Greenberg, Richard; Dermott, Stanley F.; Nicholson, Philip D.; Burns, Joseph A.

    1989-01-01

    This paper describes the original IRAS observations leading to the discovery of the three dust bands in the asteroid belt and the analysis of data. Special attention is given to an analytical model of the dust band torus and to theories concerning the origin of the dust bands, with special attention given to the collisional equilibrium (asteroid family), the nonequilibrium (random collision), and the comet hypotheses of dust-band origin. It is noted that neither the equilibrium nor nonequilibrium models, as currently formulated, present a complete picture of the IRAS dust-band observations.

  11. Parametric resonances of convection belt system

    Institute of Scientific and Technical Information of China (English)

    Zhi-an YANG; Gao-feng LI

    2009-01-01

    Based on the Coriolis acceleration and the Lagrangian strain formula,a generalized equation for the transverse vibration system of convection belts is derived using Newton's second law.The method of multiple scales is directly applied to the governing equations,and an approximate solution of the primary parameter resonance of the system is obtained.The detuning parameter,cross-section area,elastic and viscoelastic parameters,and axial moving speed have a significant influences on the amplitudes of steady-state response and their existence boundaries.Some new dynamical phenomena are revealed.

  12. Polyphase Neoproterozoic orogenesis within the east Africa- Antarctica orogenic belt in central and northern Madagascar

    Science.gov (United States)

    Key, R.M.; Pitfield, P.E.J.; Thomas, Ronald J.; Goodenough, K.M.; Waele, D.; Schofield, D.I.; Bauer, W.; Horstwood, M.S.A.; Styles, M.T.; Conrad, J.; Encarnacion, J.; Lidke, D.J.; O'connor, E. A.; Potter, C.; Smith, R.A.; Walsh, G.J.; Ralison, A.V.; Randriamananjara, T.; Rafahatelo, J.-M.; Rabarimanana, M.

    2011-01-01

    Our recent geological survey of the basement of central and northern Madagascar allowed us to re-evaluate the evolution of this part of the East Africa-Antarctica Orogen (EAAO). Five crustal domains are recognized, characterized by distinctive lithologies and histories of sedimentation, magmatism, deformation and metamorphism, and separated by tectonic and/or unconformable contacts. Four consist largely of Archaean metamorphic rocks (Antongil, Masora and Antananarivo Cratons, Tsaratanana Complex). The fifth (Bemarivo Belt) comprises Proterozoic meta-igneous rocks. The older rocks were intruded by plutonic suites at c. 1000 Ma, 820-760 Ma, 630-595 Ma and 560-520 Ma. The evolution of the four Archaean domains and their boundaries remains contentious, with two end-member interpretations evaluated: (1) all five crustal domains are separate tectonic elements, juxtaposed along Neoproterozoic sutures and (2) the four Archaean domains are segments of an older Archaean craton, which was sutured against the Bemarivo Belt in the Neoproterozoic. Rodinia fragmented during the early Neoproterozoic with intracratonic rifts that sometimes developed into oceanic basins. Subsequent Mid- Neoproterozoic collision of smaller cratonic blocks was followed by renewed extension and magmatism. The global 'Terminal Pan-African' event (560-490 Ma) finally stitched together the Mid-Neoproterozoic cratons to form Gondwana. ?? The Geological Society of London 2011.

  13. A remarkable illaenid trilobite from the Middle Ordovician of Morocco

    OpenAIRE

    Rábano, I.; Gutiérrez-Marco, J. C.; García-Bellido, D.C.

    2014-01-01

    Illaenid trilobites were relatively scarce in south-polar peri-Gondwanan areas during the Ordovician, with all their African occurrences restricted to the Middle and Upper Ordovician of Morocco. At a specific level, only the Bohemian form Ectillaenus benignensis (Novák) has been positively identified from the Middle Ordovician of that region. In the present work we add the discovery of the new form Caudillaenus nicolasi gen. et sp. nov., occurring in a single bed of late Darriwilian 2 age wit...

  14. African-Americans and Alzheimer's

    Science.gov (United States)

    ... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

  15. North African Jewish and non-Jewish populations form distinctive, orthogonal clusters.

    Science.gov (United States)

    Campbell, Christopher L; Palamara, Pier F; Dubrovsky, Maya; Botigué, Laura R; Fellous, Marc; Atzmon, Gil; Oddoux, Carole; Pearlman, Alexander; Hao, Li; Henn, Brenna M; Burns, Edward; Bustamante, Carlos D; Comas, David; Friedman, Eitan; Pe'er, Itsik; Ostrer, Harry

    2012-08-21

    North African Jews constitute the second largest Jewish Diaspora group. However, their relatedness to each other; to European, Middle Eastern, and other Jewish Diaspora groups; and to their former North African non-Jewish neighbors has not been well defined. Here, genome-wide analysis of five North African Jewish groups (Moroccan, Algerian, Tunisian, Djerban, and Libyan) and comparison with other Jewish and non-Jewish groups demonstrated distinctive North African Jewish population clusters with proximity to other Jewish populations and variable degrees of Middle Eastern, European, and North African admixture. Two major subgroups were identified by principal component, neighbor joining tree, and identity-by-descent analysis-Moroccan/Algerian and Djerban/Libyan-that varied in their degree of European admixture. These populations showed a high degree of endogamy and were part of a larger Ashkenazi and Sephardic Jewish group. By principal component analysis, these North African groups were orthogonal to contemporary populations from North and South Morocco, Western Sahara, Tunisia, Libya, and Egypt. Thus, this study is compatible with the history of North African Jews-founding during Classical Antiquity with proselytism of local populations, followed by genetic isolation with the rise of Christianity and then Islam, and admixture following the emigration of Sephardic Jews during the Inquisition. PMID:22869716

  16. Fostering a Middle Class

    Institute of Scientific and Technical Information of China (English)

    YAO BIN

    2011-01-01

    Though there is no official definition of "middle class" in China,the tag has become one few Chinese people believe they deserve anyway.In early August,the Chinese Academy of Social Sciences released a report on China's urban development,saying China had a middle-class population of 230 million in 2009,or 37 percent of its urban residents.It also forecast half of city dwellers in China would be part of the middle class by 2023.

  17. African American Men’s Perspectives on Promoting Physical Activity: “We’re Not That Difficult to Figure out!”

    OpenAIRE

    Friedman, Daniela B.; Hooker, Steven P.; Wilcox, Sara; Burroughs, Ericka L.; Rheaume, Carol E.

    2012-01-01

    African American men report poorer health than do White men and have significantly greater odds for developing chronic diseases partly because of limited physical activity. Understanding how to encourage healthy behaviors among African American men will be critical in the development of effective physical activity messages and programs. Guided by principles of cultural sensitivity and social marketing, this research examined middle-aged and older African American men’s recommended strategies ...

  18. African Cultural Astronomy

    CERN Document Server

    Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa

    2008-01-01

    Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

  19. Stabilization of electrostatic accelerator charging belt current

    International Nuclear Information System (INIS)

    For the purpose of improving reliability and quality of electrostatic accelerator basic parameters the stabilizer of charging belt current is developed. The stabilizer consists of two units: high-voltage unit and control unit. The charging rectifier assures voltage up to 60 kV at total current load of 750 μA. For the EG- 2.5 and the EGP-10 M accelerators supply circuits of charging device with an earth screen and posAitive voltage supply the needles. t the EGP-10-1 accelerator negative charging voltage is supplied to the screens of the charging device. ''Plus'' of the rectifier is earthed. Charging and recharging are performed by means of brushes slipping over the internal belt side. At all accelerators the stability of charging current mean value is not worse 0.1%. The highest response of the system are obtained at the EG-2.5 accelerator for account of rectifier load by charging current and instrument resistor from 140 to 400 MOhm

  20. Fading of Jupiter's South Equatorial Belt

    Science.gov (United States)

    Sola, Michael A.; Orton, Glenn; Baines, Kevin; Yanamandra-Fisher, Padma

    2011-01-01

    One of Jupiter's most dominant features, the South Equatorial Belt, has historically gone through a "fading" cycle. The usual dark, brownish clouds turn white, and after a period of time, the region returns to its normal color. Understanding this phenomenon, the latest occurring in 2010, will increase our knowledge of planetary atmospheres. Using the near infrared camera, NSFCAM2, at NASA's Infrared Telescope Facility in Hawaii, images were taken of Jupiter accompanied by data describing the circumstances of each observation. These images are then processed and reduced through an IDL program. By scanning the central meridian of the planet, graphs were produced plotting the average values across the central meridian, which are used to find variations in the region of interest. Calculations using Albert4, a FORTRAN program that calculates the upwelling reflected sunlight from a designated cloud model, can be used to determine the effects of a model atmosphere due to various absorption, scattering, and emission processes. Spectra that were produced show ammonia bands in the South Equatorial Belt. So far, we can deduce from this information that an upwelling of ammonia particles caused a cloud layer to cover up the region. Further investigations using Albert4 and other models will help us to constrain better the chemical make up of the cloud and its location in the atmosphere.

  1. Young Stellar Objects in the Gould Belt

    CERN Document Server

    Dunham, Michael M; Evans, Neal J; Broekhoven-Fiene, Hannah; Cieza, Lucas; Di Francesco, James; Gutermuth, Robert A; Harvey, Paul M; Hatchell, Jennifer; Heiderman, Amanda; Huard, Tracy; Johnstone, Doug; Kirk, Jason M; Matthews, Brenda C; Miller, Jennifer F; Peterson, Dawn E; Young, Kaisa E

    2015-01-01

    We present the full catalog of Young Stellar Objects (YSOs) identified in the 18 molecular clouds surveyed by the Spitzer Space Telescope "cores to disks" (c2d) and "Gould Belt" (GB) Legacy surveys. Using standard techniques developed by the c2d project, we identify 3239 candidate YSOs in the 18 clouds, 2966 of which survive visual inspection and form our final catalog of YSOs in the Gould Belt. We compile extinction corrected SEDs for all 2966 YSOs and calculate and tabulate the infrared spectral index, bolometric luminosity, and bolometric temperature for each object. We find that 326 (11%), 210 (7%), 1248 (42%), and 1182 (40%) are classified as Class 0+I, Flat-spectrum, Class II, and Class III, respectively, and show that the Class III sample suffers from an overall contamination rate by background AGB stars between 25% and 90%. Adopting standard assumptions, we derive durations of 0.40-0.78 Myr for Class 0+I YSOs and 0.26-0.50 Myr for Flat-spectrum YSOs, where the ranges encompass uncertainties in the ado...

  2. African names for American plants

    NARCIS (Netherlands)

    Andel, van T.R.

    2015-01-01

    African slaves brought plant knowledge to the New World, sometimes applying it to related plants they found there and sometimes bringing Old World plants with them. By tracing the linguistic parallels between names for plants in African languages and in communities descended from African slaves, pie

  3. The Struggles over African Languages

    Science.gov (United States)

    Maseko, Pam; Vale, Peter

    2016-01-01

    In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

  4. Economic Research on the Arab world and the Middle East

    DEFF Research Database (Denmark)

    Wippel, Steffen

    2015-01-01

    The article gives an overview of the Development of contemporary research on Middle Eastern and North African economies in Germany. It includes the most important institutions and central research topics and approaches, underlining that this field is, in fact, multidisciplinary. The article also...... points out some of its most salient structural, conceptual, and methodological problems. Referring to research on regionalization processes, the author advocates an open, transregional and transdisciplinary approach closely based on empirical findings....

  5. High osteoporosis risk among East Africans linked to lactase persistence genotype.

    Science.gov (United States)

    Hilliard, Constance B

    2016-01-01

    This ecological correlation study explores the marked differential in osteoporosis susceptibility between East and West Africans. African tsetse belt populations are lactase non-persistent (lactose intolerant) and possess none of the genetic polymorphisms carried by lactase persistent (lactose tolerant) ethnic populations. What appears paradoxical, however, is the fact that Niger-Kordofanian (NK) West African ethnicities are also at minimal risk of osteoporosis. Although East Africans share a genetic affinity with NK West Africans, they display susceptibility rates of the bone disorder closer to those found in Europe. Similar to Europeans, they also carry alleles conferring the lactase persistence genetic traits. Hip fracture rates of African populations are juxtaposed with a global model to determine whether it is the unique ecology of the tsetse-infested zone or other variables that may be at work. This project uses MINITAB 17 software for regression analyses. The research data are found on AJOL (African Journals Online), PUBMED and JSTOR (Scholarly Journal Archive). Data showing the risk of osteoporosis to be 80 times higher among East Africans with higher levels of lactase persistence than lactase non-persistence West Africans are compared with global statistics. Hip fracture rates in 40 countries exhibit a high Pearson's correlation of r=0.851, with P-value=0.000 in relation to dairy consumption. Lower correlations are seen for hip fracture incidence vis-à-vis lactase persistence, per capita income and animal protein consumption. Ethnic populations who lack lactase persistence single-nucleotide polymorphisms may be at low risk of developing osteoporosis.

  6. 30 CFR 57.4263 - Underground belt conveyors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground belt conveyors. 57.4263 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Equipment § 57.4263 Underground belt conveyors. Fire protection shall...

  7. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

    Brincker, Rune; Frandsen, J. B.; Andersen, P.

    2000-01-01

    In this paper an ambient response analysis of the Great Belt Bridge is presented. The Great Belt Bridge is one of the largest suspension bridges in the world, and the analysis was carried out in order to investigate the possibilities of estimating reliable damping values from the ambient response...

  8. Teaching Taekwondo in Physical Education: Incorporating the Color Belt System

    Science.gov (United States)

    Oh, Hyun-Ju; Hannon, James C.; Banks, Aaron

    2006-01-01

    Taekwondo is an excellent lifetime physical activity that provides both physical and mental benefits to its participants. The color belt system may be creatively used in physical education to encourage improvement in all learning domains. This article provides information on incorporating the color belt system into physical education, and provides…

  9. Safety belt usage in Finland and in other Nordic countries.

    NARCIS (Netherlands)

    Valtonen, J.

    1992-01-01

    Legislation has played a significant role in increasing safety belt usage in Finland and in the other Nordic countries. Publicity and enforcement have, however, been required to support the legislation. The development of safety belt regulations has been nearly similar in all these countries, both i

  10. Canadian seat belt wearing rates, promotion programs, and future directions.

    NARCIS (Netherlands)

    Grant, B.A.

    1992-01-01

    On the basis of a national driver seat belt survey conducted in Canada each year, the most important results are presented. A number of programmes for increasing seat belt use has been evaluated in Canada. Finally, a description is given of some of the current and planned activities within Canada wh

  11. Geophysical profiling across the Sulu ultra-high-pressure metamorphic belt, eastern China

    Science.gov (United States)

    Yang, Wencai

    2002-09-01

    The largest ultra-high pressure metamorphic (UHPM) belt in the world is located along the Dabie-Sulu region, which tectonically belongs to the east part of the central orogenic belt of China. Integrated geophysical investigations of using deep seismic reflection, MT, and geothermal observations have been carried out in the Sulu area since 1997. The results of integrated interpretation suggest the existence of three features: (1) a rift beneath the Lianshui basin by the Jiashan-Xionshui fault; (2) a special crustal pattern, called the magmatic multi-arch structure occurs beneath the northern Sulu UHPM zone; and (3) a northwest-dipping regional thrust crosses the Sulu crust, representing the intracontinental subduction of the Yangtze craton beneath the Sulu metamorphic belts after collision between the Yangtze and Sino-Korean cratons. A magmatic multi-arch structure consists of some arched reflectors that occur in both the lower and the upper crust where arched reflectors coincide with granitoid plutons. The multi-arch structures are common in eastern China where many Mesozoic granitoid plutons of different scales occur. The crustal structures in the Sulu metamorphic belts resulted from intensive dynamic processes following the Triassic collision between the Yangtze and Sino-Korean cratons. The formation and exhumation of UHPM rocks followed the collision, and then intracontinental subduction of the Yangtze craton beneath the Dabie-Sulu terranes took place in the early and middle Jurassic. In the late Jurassic, the Sulu lithosphere turned to an extensional regime, large-scale granitic intrusions occurred in eastern China; these likely resulted from lithospheric thinning and asthenospheric uplifting. The granitic intrusions came to a climax during the Cretaceous and were followed by rifting along existing faults in the early Eogene, resulting in many petroleum basins. The granitoid emplacement that generated the magmatic multi-arch structure and the rift were

  12. Growth of the Zagros Fold-Thrust Belt and Foreland Basin, Northern Iraq, Kurdistan

    Science.gov (United States)

    Koshnaw, Renas; Horton, Brian; Stockli, Daniel; Barber, Douglas; Ghalib, Hafidh; Dara, Rebwar

    2016-04-01

    The Zagros orogenic belt in the Middle Eastern segment of the Alpine-Himalayan system is among the youngest seismically active continental collision zones on Earth. However, due to diachronous and incremental collision, the precise ages and kinematics of shortening and deposition remain poorly understood. The Kurdistan region of the Zagros fold-thrust belt and foreland basin contains well-preserved Neogene wedge-top and foredeep deposits that include clastic nonmarine fill of the Upper Fars, Lower Bakhtiari, and Upper Bakhtiari Formations. These deposits record significant information about orogenic growth, fold-thrust dynamics, and advance of the deformation front. Thermochronologic and geochronologic data from thrust sheets and stratigraphic archives combined with local earthquake data provide a unique opportunity to address the linkages between surface and subsurface geologic relationships. This research seeks to constrain the timing and geometry of exhumation and deformation by addressing two key questions: (1) Did the northwestern Zagros fold-thrust belt evolve from initial thin-skinned shortening to later thick-skinned deformation or vice-versa? (2) Did the fold-thrust belt advance steadily under critical/supercritical wedge conditions involving in-sequence thrusting or propagate intermittently under subcritical conditions with out-of-sequence deformation? From north to south, apatite (U-Th)/He ages from the Main Zagros Thrust, the Mountain Front Flexure (MFF), and additional frontal thrusts suggest rapid exhumation by ~10 Ma, ~5 Ma, and ~8 Ma respectively. Field observations and seismic sections indicate progressive tilting and development of growth strata within the Lower Bakhtiari Formation adjacent to the frontal thrusts and within the Upper Bakhtiari Formation near the MFF. In the Kurdistan region of Iraq, a regional balanced cross section constrained by new thermochronometric results, proprietary seismic reflection profiles, and earthquake hypocenters

  13. Early Cenozoic Shortening and Foreland Basin Sedimentation in the Marañon Fold-thrust Belt, Central Peruvian Andes

    Science.gov (United States)

    Jackson, L. J.; Carlotto, V.; Horton, B. K.; Rosell, L. N.

    2015-12-01

    The Marañon fold-thrust belt in the westernmost Andes of Peru has long been considered a robust signature of early Cenozoic shortening in the Andean orogenic belt. However, the structural details and potential records of coeval synorogenic sedimentation remain elusive. We report results from new geologic mapping (1:50,000), cross-section construction, and U-Pb geochronology for the Matucana-Ticlio region at 11-12°S along the Lima-La Oroya highway. Zircon U-Pb age data from volcanic rocks and clastic basin fill provide a maximum depositional age of ~43 Ma for a middle Eocene syndeformational unit that we identify as the Anta Formation, which overlies the Paleocene Casapalca Formation. Sedimentary lithofacies and unconformable relationships within the volcaniclastic Anta Formation reveal mixed fluvial, alluvial-fan, and volcanic depositional conditions during shortening accommodated by a NE-verging thrust/reverse fault and corresponding backthrust (here named the Chonta fault system). Our cross-section reconstruction and geochronological data indicate that the region is a critical, possibly unique, zone of the broader NE-directed Marañon fold-thrust belt where pre-Neogene synorogenic sediments and their associated structures are preserved. We interpret this combined structural and basin system as an Eocene-age (Incaic) frontal thrust belt and corresponding foredeep to wedge-top depozone in central Peru. As one of the better-constrained segments of the Marañon fold-thrust belt, this zone provides insight into potential linkages with elusive early Cenozoic (Incaic) structures and foreland basin fill of the Western Cordillera and Altiplano farther south in the central Andean plateau.

  14. Landscape distribution characteristics of northern foothill belts of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The foothill belts of Tianshan Mountains are about 280 km long and 60 km wide, and the study area extends from Kuitun city to Fukang city. They are transitional belts between mountains and plains, appearing in three rows of folds with different morphologies and their age becoming younger from south to north. Based on GIS and RS methods, and materials of the previous researchers, this paper deals with the genetics of the foothill belts and their landscape features resulting from folding by neotectonic movements, and also describes their length, width and slope by remote sensing image interpretation. The characteristics of the foothill belts are found to be very important for the surrounding environment by preventing groundwater from flowing into plains, changing groundwater, increasing flow of surface runoff, in addition to their roles in protecting the surrounding environment. The purpose of this paper is to provide an in-depth understanding of the foothill belts and influence on its surrounding environment.

  15. a Wave Model for a Pneumatic Tyre Belt

    Science.gov (United States)

    PINNINGTON, R. J.; BRISCOE, A. R.

    2002-06-01

    A one-dimensional wave equation of an infinite flattened tyre belt is generated. The belt vibration is controlled by bending, tension, shear and the sidewall stiffness. The dispersion relations for two waves in the belt are calculated and used to find both the input impedance and attenuation on a tyre belt of infinite extent. Tension and the sidewall controls the deformation and stiffness below 100Hz. Waves propagate around the belt above this frequency. The wave speeds due to bending and shear were predicted and measured. The model presented here should be valid for the prediction of tyre response above about 400 Hz when for a car tyre the modal behaviour is observed to cease. In this high-frequency region, the tyre at the input appears to be of infinite extent.

  16. Radiation-belt dynamics during solar minimum. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G.; Holeman, E.

    1989-12-01

    Two types of temporal variation in the radiation belts are studied using low altitude data taken onboard the DMSP F7 satellite: those associated with the solar cycle and those associated with large magnetic storm effects. Over a three-year period from 1984 to 1987 and encompassing solar minimum, the protons in the heart of the inner belt increased at a rate of approximately 6% per year. Over the same period, outer zone electron enhancements declined both in number and peak intensity. During the large magnetic storm of February 1986, following the period of peak ring current intensity, a second proton belt with energies up to 50 MeV was found at magnetic latitudes between 45 deg. and 55 deg. The belt lasted for more than 100 days. The slot region between the inner and outer electron belts collapsed by the merging of the two populations and did not reform for 40 days.

  17. Experimental Measurements of Belt Gears in Newly Developed Device

    Directory of Open Access Journals (Sweden)

    Jozef Mascenik

    2016-05-01

    Full Text Available The paper deals with the alternative of determination of state of the belt gear. To realize themeasurements a newly developed device was designed for measurement and diagnostics of the belt gears. The main task is to detect the V-belt slip expressed by the coefficient of elastic creep and of specific slip with a measuring device. The measurements regarding can be performed if input revolutions of the electric motor and torque of the belt gear are constant whereas the tensioning force of the belt gear changes. It is also possible to perform the measurement if the input revolutions of the electric motor and the tensioning forces are constant and the torque changes.

  18. Methods for identifying Neisseria meningitidis carriers: a multi-center study in the African meningitis belt.

    Directory of Open Access Journals (Sweden)

    Nicole E Basta

    Full Text Available Detection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers.We conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U to swabbing the posterior pharynx behind the uvula plus one tonsil (T. Swabs were cultured immediately and analyzed using molecular methods.One thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6% based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7% versus 4.9% (95% CI: 3.6-6.4% respectively (p=0.6. The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73, indicating good agreement.These two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence.

  19. Middle East Respiratory Syndrome

    Centers for Disease Control (CDC) Podcasts

    2014-07-07

    This podcast discusses Middle East Respiratory Syndrome, or MERS, a viral respiratory illness caused by Middle East Respiratory Syndrome Coronavirus—MERS-CoV.  Created: 7/7/2014 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 7/7/2014.

  20. DEFINING THE MIDDLE CLASS

    Institute of Scientific and Technical Information of China (English)

    WANG HAIRONG

    2011-01-01

    China's cities housed more than 230 million middle-class residents in 2009ot 37 percent of the urban population,according to the 2011 Blue Book of Cities in China released on August 3.In China's main urban centers,Beijing and Shanghai,the middle class accounted for 46 percent and 38 percent,respectively,of the local population.

  1. DEFINING THE MIDDLE CLASS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Classifying the middle class remains controversial despite its alleged growth China’s cities housed more than 230 million middle-class residents in 2009 or 37 percent of the urban population,according to the 2011 Blue Book of Cities in China released on August 3.

  2. A Study on the Vibration of the Charging Belt in an Electrostatic Accelerator

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The vibration of the charging belt in an electrostatic accelerator has intense influences on the accelerator operation. A calculating model was set up in this paper to study the belt vibration. The results show that the belt tension, belt velocity and belt current all contribute to the belt vibration. There is an optimal relationship among the three factors by which the belt would run most smoothly. There exists a minimum value of optimal tension for various belt velocities. The vibrating frequency of the is generally around several Hz.

  3. African Women Writing Resistance

    Institute of Scientific and Technical Information of China (English)

    Jennifer Browdy de Hernandez; Pauline Dongala; Omotayo; Jolaosho; Anne Serafin

    2011-01-01

    AFRICAN Women Writing Resistance is the first transnational anthology to focus on women's strategies of resistance to the challenges they face in Africa today.The anthology brings together personal narratives,testimony,interviews,short stories,poetry,performance scripts,folktales and lyrics.

  4. African Women Writing Resistance

    Institute of Scientific and Technical Information of China (English)

    Jennifer; Browdy; de; Hernandez; Pauline; Dongala; Omotayo; Jolaosho; Anne; Serafin

    2011-01-01

    An Anthology of Contemporary Voices AFRICAN Women Writing Resistance is the first transnational anthology to focus on women’s strategies of resistance to the challenges they face in Africa today.The anthology brings together personal narratives,testimony,interviews, short stories,po-

  5. Deepening African Ties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chinese President Hu Jintao has just embarked on his state visits to eight African countries that will take him to both the northern and southern tips of the continent. This is his first trip abroad this year, and also his third visit to Africa

  6. East African institutions

    DEFF Research Database (Denmark)

    Nordby, Johannes Riber; Jacobsen, Katja

    For the past decade security in East Africa has gained focus internationally. However there is a growing ambition among African states to handle such issues by themselves, sometimes through regional institutions. This has been supported by many Western states but potential risks are often forgotten....

  7. African tick bite fever

    DEFF Research Database (Denmark)

    Johansen, Jakob Aaquist; Thybo, Søren

    2011-01-01

    The incident of spotted fever imported to Denmark is unknown. We present a classic case of African Tick Bite Fever (ATBF) to highlight a disease, which frequently infects wildlife enthusiasts and hunters on vacation in South Africa. ATBF has a good prognosis and is easily treated with doxycyclin...

  8. West African Antislavery Movements

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi; Pelckmans, Lotte

    2011-01-01

    In the context of liberalization of West African political regimes, the upsurge of audacious political entrepreneurs who want to end chattel slavery in their nation-state, resulted in the legal criminalisation of slavery in both Mauritania (2007) and Niger (2003) and in a proposal to revise the...... cultures (or ‘mentalities’) go hand in hand....

  9. Immunizations and African Americans

    Science.gov (United States)

    ... Program Grants Other Grants Planning and Evaluation Grantee Best Practices Black/African American Asthma Cancer Chronic Liver Disease ... 13 to 17 years who ever received the human papillomavirus (HPV) vaccination, 2014 - Males # doses ... 240-453-2882 Office of Minority Health Resource Center Toll Free: 1-800-444-6472 / Fax: ...

  10. Equilibria and Free Vibration of a Two-Pulley Belt-Driven System with Belt Bending Stiffness

    Directory of Open Access Journals (Sweden)

    Jieyu Ding

    2014-01-01

    Full Text Available Nonlinear equilibrium curvatures and free vibration characteristics of a two-pulley belt-driven system with belt bending stiffness and a one-way clutch are investigated. With nonlinear dynamical tension, the transverse vibrations of the translating belt spans and the rotation motions of the pulleys and the accessory shaft are coupled. Therefore, nonlinear piecewise discrete-continuous governing equations are established. Considering the bending stiffness of the translating belt spans, the belt spans are modeled as axially moving beams. The pattern of equilibria is a nontrivial solution. Furthermore, the nontrivial equilibriums of the dynamical system are numerically determined by using two different approaches. The governing equations of the vibration near the equilibrium solutions are derived by introducing a coordinate transform. The natural frequencies of the dynamical systems are studied by using the Galerkin method with various truncations and the differential and integral quadrature methods. Moreover, the convergence of the Galerkin truncation is investigated. Numerical results reveal that the study needs 16 terms after truncation in order to determine the free vibration characteristics of the pulley-belt system with the belt bending stiffness. Furthermore, the first five natural frequencies are very sensitive to the bending stiffness of the translating belt.

  11. Africa's new middle class: fact and fiction of its transformative power

    OpenAIRE

    Giesbert, Lena; Schotte, Simone

    2016-01-01

    Africa's middle class has become a central protagonist in the development discourse. Beyond providing hope of economic growth, some analysts see it as a bastion of political stability, progress, and democratic consolidation. Many recent protests and (partly successful) attempts to overthrow ageing statesmen who tried to overstay in power have been connected by the media to the rise of an African middle class. After a decade of strong but largely jobless economic growth, the bulk of sub-Sahara...

  12. Creativity in the late middle childhood : development and gender differences / Ester Corné Brink

    OpenAIRE

    Brink, Ester Corné

    2003-01-01

    Many studies have been performed on creativity and the measurement of creativity. However, little is known about the relationship between gender differences and creativity, particularly in South Afnca. The current study aimed to investigate the difference in creativity between boys and girls, as well as the development of creativity in late middle childhood, in the South African context. From the random sample of 1000 primary school children in late middle childhood (grade 4 to...

  13. East Central Uplift Belt of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Mosuowandong ( Z3 ) and Dongdaohaizi (Z4) are two bidding blocks located in the east part of central uplift Belt, the hinterland of Junggar Basin. Xinjiang Uygur Autonomous Region. It totally covers an area of 8 100km2. Topographically, the two blocks are quite gentle with elevation of 380-400 m on average. The north part is desert and the south area is good for farming. There are three ephemeral streams flowing across the desert from south to north. The ground water is buried at the depth ranging from 6 to 8 m. It belongs to continental climate with the annually averaged precipitation of 80 mm. The traffic is rather convenient in the south part of both blocks. There are several sand-paved roads and two asphalt roads connected with the highway from Karamay to Urumqi City.

  14. The Foundations of Radiation Belt Research

    Science.gov (United States)

    Ludwig, G. H.

    2008-12-01

    phenomenon. It also provided the first hint that there were two distinct radiation belts, although that conclusion was not reached until later. Although that new information was quickly announced, the results of the high altitude nuclear detonations were kept secret until well into 1959. They clearly revealed the charged particle shells created by the Argos nuclear detonations. The next major step in mapping and understanding the high-intensity radiation involved the launch of deep space probes Pioneers III and IV in December 1958 and March 1959. Although both launches fell short in their primary objective, to reach the moon, they traveled far enough from the Earth to fully meet the needs of the scientific experiment. They very clearly showed the two-radiation belt structure, and mapped its extent. They also showed the probable effect of a magnetic storm on 25 February, thus indicating the direct influence of solar activity on the outer belt. By the end of 1959, the existence of the Van Allen Radiation Belts and their general structure were solidly established, early information about the composition of the radiation was appearing in print, and energetic work was under way to understand the physics of the processes involved.

  15. Middle proterozoic supra crustal and brazilian orogeny in the southeast Ceara state: a mono cyclic evolution

    International Nuclear Information System (INIS)

    The Oros belt is situated in the southeastern part of Ceara state, Brazil, and geologically pertains to the Borborema province. This belt comprises a volcano-sedimentary sequence of middle proterozoic age resting unconformably upon basement of Archean/low proterozoic age. In the geological map of Ceara state, this belt displays an elongate shape towards N-S, turning to ENE-WSW in the south, and reaches 12 km wide in the central park. This paper describes the relationships between the country rocks and the supra crustal sequence, as well as the plutonic intrusions and their tectonic metamorphic evolution. New Rb-Sr whole-rock dates are presented which are very important to separate anorogenic and syn-orogenic granites. (author)

  16. Female genital mutilation in African and African American women's literature

    Directory of Open Access Journals (Sweden)

    Darja Marinšek

    2007-12-01

    Full Text Available The article builds on the existing dispute between African and African American women writers on the competence of writing about female genital mutilation (FGM, and tries to determine the existence and nature of the differences between the writings of these two groups. The author uses comparative analysis of two popular African and African American novels, comparing their ways of describing FGM, its causes and consequences, the level ob objectivity and the style of the narrations.This is followed by a discussion on the reasons for such differences, incorporating a larger circle of both African and African American women authors, at the same time analysing the deviance within the two groups. While the differences between African American writers are not that great, as they mostly fail to present the issue from different points of view, which is often the result of their lack of direct knowledge of the topic, African authors' writing is in itself discovered to be ambivalent and not at all invariable. The reasons for such ambivalence are then discussed in greater context, focusing on the effect of the authors' personal contact with circumcision as well as their knowledge and acceptance of Western values. The author concludes by establishing the African ambivalent attitude towards FGM, which includes different aspects of the issue, as the most significant difference between their and African American writers' description of this practice.

  17. Language Endangerment and the Violent Ethnic Conflict Link in Middle Belt Nigeria

    Science.gov (United States)

    Ioratim-Uba, Godwin Aondona

    2009-01-01

    This paper highlights the fact that language endangerment in some multilingual developing societies is causal to the violent ethnic conflicts in those societies. Endangered language identity groups shift to the dominant language groups. But, over time, a concatenation of factors and nuanced realisation of perceived marginalisation (showing overtly…

  18. Assessing the Key Attributes of Low Utilization of Mammography Screening and Breast-self Exam among African-American Women

    OpenAIRE

    Chowdhury, Rupak; David, Nganwa; Bogale, Asseged; Nandy, Shami; Habtemariam, T.; Tameru, Berhanu

    2016-01-01

    PURPOSE: African-American (AA) women living in four Black Belt Counties (BBC) of Alabama; consisting of Barbour, Macon, Green and Wilcox are known to have lower mammogram utilization and breast self-exam rates when compared to their white female counterparts. The influence of socioeconomic and demographic factors on these disparities has not been clearly defined so far. Our study was designed to determine whether these observed disparities can be predicted with the socioeconomic and other dem...

  19. Abundance and structure of African baobab (Adansonia digitata) across different soil types in Gonarezhou National Park, Zimbabwe

    OpenAIRE

    Clayton Mashapa; Patience Zisadza-Gandiwa; Edson Gandiwa; Shakkie Kativu

    2013-01-01

    This study investigated the abundance and structure of African baobab (Adansonia digitata) across soil group strata in Gonarezhou National Park, Zimbabwe. The study was based on a stratified random sampling design composed of the following soil group substrates: (i) granophyres, (ii) malvernia, and (iii) rhyolite. Belt transects of 0.3 x 0.1 ¿km were randomly laid across soil group. Baobab abundance and population structure were determined from the density and size class distribution, respect...

  20. Exhalative Lead-Zinc Deposits in Shallow Sea, Southern Xicheng Belt, Gansu Province

    Institute of Scientific and Technical Information of China (English)

    ZHU Xinyou; WANG Dongbo; WEI Zhiguo; QIU Xiaoping; WANG Ruiting

    2008-01-01

    SEDEX-type lead-zinc deposits in the southern belt of the Xicheng Devonian basin, GansuProvince has been already identified. However, the sedimentary environment of the limestone andphilite of the Xihanshui Group within which the lead-zinc deposits occur is littoral and shallow sea.This is different from those in the northern belt such as the Changba-Lijiagou lead-zinc deposits, whichwere formed in deep sea. The reef and bioclastic limestone are widespread in the southern belt.Particularly they are associated with lead-zinc ores and there are no striae and banding but massive ordisseminated structures. It is discovered that the black chimney consists of sphalerite, ankerite, pyriteand galena, in which black, coarse and radial sphalerite occurs as irregularly veins or cylindricafitywith a width of 10-40 cm in the center, and it is surround by fine ankerite and minor celestite withribbon structure. The immediate wall rock of the chimney, reef limestone, was unaltered and theoutside reef and bioclastic limestone were intensively silicified. Those silicified reef and bioclasticlimestone host disseminated lead-zinc ores of the Lnoba and Bijiashan type. It is concluded that theexhalative system occurred in a shallow sea in the Givetian of the middle Devonian. Brine is boiled dueto low pressure, and a great deal of lead and zinc was dispersed in the interface between the limestoneand phyllite and formed a source bed. In the Triassic period, meta-hydrothermai fluids leached andextracted metals from the source bed, and then moved and mineralized in open space such as archesand inverse limbs of anticlines, and formed massive and vein ores such as the Jianyagou andDengjiashan type deposits.

  1. Geometry, kinematics and evolution of the Tongbai orogenic belt

    Institute of Scientific and Technical Information of China (English)

    HUANG Shaoying; XU Bei; WANG Changqiu; ZHAN Sheng; DENG Rongjing

    2006-01-01

    The Tongbai orogenic belt (TOB) is composed of six tectonic units. From south to north these units are: Tongbai gneiss rise (TGR); Hongyihe-Luozhuang eclogite belt (HLE); Maopo-Hujiazhai igneous rock belt (MHI); Zhoujiawan flysch belt (ZFB); Yangzhuang greenschist belt (YGB); and Dongjiazhuang marble belt (DMB).The geometry and kinematic images of the TOB include: the antiformal structures caused by a later uplift process, the top-to-north ductile shear structure that related to a process that the ultrahigh pressure rocks are brought to surface, the top-to-south ductile shear thrust and the sinistrial shear structures related to a south-north direction compression, and the east-west direction fold structures in the upper crust. In the view of the multistage subduction-collision orogenic belt, according to the characters of petrology and its distribution, geometry, kinematics and structural chronology in these tectonic units, tectonic evolution of the TOB can be divided into four stages: oceanic crust subduction during 400-300 Ma, continental collision during 270-250 Ma, continental deep subduction and uplift during 250-205 Ma and doming deformation during 200-185 Ma.

  2. Leadership in the African context

    Directory of Open Access Journals (Sweden)

    M. Masango

    2002-08-01

    Full Text Available The Western world has always viewed the African continent as plagued by corruption; dictatorship; military coups; rebellious leaders; greediness; misuse of power; and incompetent, politically unstable leaders - in effect, suspicious leaders who undermine their own democracies. This paper analyzes African leadership and its impact by concentrating on three historical eras, namely; the African Religious era; the Christian era, and the era of Globalization. These affected African leadership. In addition, many brilliant minds left the continent in search of greener pastures. A review of these three eras will help us understand how leadership shifted from African values into Western concepts. The role of missionaries lead African people to live with both an African and a Western concept of life. In spite of the above problems, our past leaders did their best in addressing the difficulties they faced during the three eras. African concepts of leadership were often regarded as barbaric and uncultured. Structures were evaluated by Western standards. Due to globalisation, African leaders, through programmes like NEPAD, are going back to basics, drawing on African concepts of unity among its leadership. Effectiveness or life-giving leadership is emerging and empowering villagers/communities in the continent. This type of leadership is innovative and has brought new hope for the continent.

  3. IEA studies Middle East

    International Nuclear Information System (INIS)

    Oil production policy in most of the major producing countries of the Middle East looks likely to change as a result of financial constraints and pressures on demand. This -implicitly rather than explicitly - is perhaps the main conclusion to be drawn from the International Energy Agency's (IEA) magisterial study on Middle East oil and gas, in which the production capacities, energy development policies and the structural economic problems of six major oil and gas producers in the region are examined. ''Middle East Oil and Gas'' is available from the IEA/OECD Publications Service. (author)

  4. On middle cube graphs

    Directory of Open Access Journals (Sweden)

    C. Dalfo

    2015-10-01

    Full Text Available We study a family of graphs related to the $n$-cube. The middle cube graph of parameter k is the subgraph of $Q_{2k-1}$ induced by the set of vertices whose binary representation has either $k-1$ or $k$ number of ones. The middle cube graphs can be obtained from the well-known odd graphs by doubling their vertex set. Here we study some of the properties of the middle cube graphs in the light of the theory of distance-regular graphs. In particular, we completely determine their spectra (eigenvalues and their multiplicities, and associated eigenvectors.

  5. On middle cube graphs

    OpenAIRE

    Dalfo, C.; Fiol, M.A.; Mitjana, M.

    2015-01-01

    We study a family of graphs related to the $n$-cube. The middle cube graph of parameter k is the subgraph of $Q_{2k-1}$ induced by the set of vertices whose binary representation has either $k-1$ or $k$ number of ones. The middle cube graphs can be obtained from the well-known odd graphs by doubling their vertex set. Here we study some of the properties of the middle cube graphs in the light of the theory of distance-regular graphs. In particular, we completely determine their spectra (eigenv...

  6. The Relation among Parental Factors and Achievement of African American Urban Youth

    Science.gov (United States)

    Wilson, Clancie Mavello

    2009-01-01

    Research has suggested that low socioeconomic status is a major factor in diminishing academic achievement of African American urban youth; however, there are other factors influencing students' achievement. To examine the other factors that contribute to academic achievement, this study investigated a sample of 60 low-resource middle school…

  7. Critical Multimodal Hip Hop Production: A Social Justice Approach to African American Language and Literacy Practices

    Science.gov (United States)

    Turner, K. C. Nat; Hayes, Nini, Visaya; Way, Kate

    2013-01-01

    This article features key findings from a study that highlights the transformative impact of a pedagogical approach that employs Critical Multimodal Hip Hop Production (CMHHP). The study took place in an extended day program in a northern California public middle school among a group of 30, urban, African American, Chicano/a/Latino/a, and Asian…

  8. You Better Recognize!: The Arts as Social Justice for African American Students

    Science.gov (United States)

    Hanley, Mary Stone

    2011-01-01

    Social justice is a complex theory and practice that includes the equitable redistribution of resources and the recognition of culture. This is a report about the Tubman Theater Project, a culturally relevant drama program in which African American middle and high school students confronted racism and classism, as well as their unexamined…

  9. Towards an Integrated Learning Strategies Approach to Promoting Scientific Literacy in the South African Context

    Science.gov (United States)

    Webb, Paul

    2009-01-01

    The focus of this paper is on selected recent South African research studies that have explored efforts to promote the discussion, writing, and arguing aspects of scientific literacy in primary and middle schools, particularly amongst second-language learners. These studies reveal improvements in the participants' abilities to both use the…

  10. Australian Palaeozoic palaeomagnetism and tectonics—I. Tectonostratigraphic terrane constraints from the Tasman Fold Belt

    Science.gov (United States)

    Powell, C. McA.; Li, Z. X.; Thrupp, G. A.; Schmidt, P. W.

    The Tasman Fold Belt (TFB) of Eastern Australia can be divided into three meridional orogenic realms: the Kanmantoo, Lachlan-Thomson and New England Orogens. The geological histories of the orogens overlap, but each is distinctive. The Kanmantoo Orogen was provenance-linked to the Australian craton in the Early Cambrian, and accreted to Australia by Late Cambrian. There are many possible tectonostratigraphic terranes in the Lachlan Fold Belt (LFB) but these can be simplified to two major amalgamated terranes by the Middle Silurian. All the LFB terranes appear provenance-linked in the Ordovician, and were progressively covered, from the west, during the Late Silurian to Late Devonian, by a quartzose overlap assemblage. The New England Orogen has a fragmentary Early Palaeozoic history, but from the Devonian onwards its geology is related to a series of volcanic island and continental margin magmatic arcs. There is some evidence of provenance-linking between the Lachlan and New England Orogens in the Devono-Carboniferous but docking is not demonstrated until the mid-Carboniferous. The few reliable pre-Late Carboniferous palaeomagnetic poles available from the TFB come from the eastern LFB. The poles post-date accretion of the LFB to the Australian craton. Thus, the possibility that parts of the Lachlan-Thomson and New England Orogens contain exotic elements is yet to be tested palaeomagnetically.

  11. Agricultural Change in the Russian grain belt: a case study of Samara Oblast

    Science.gov (United States)

    de Beurs, K. M.; Ioffe, G.

    2011-12-01

    Agricultural reform has been one of the most important anthropogenic change processes in European Russia that has been unfolding since the collapse of the Soviet Union at the end of 1991. Besides the ongoing land abandonment as a result of agricultural reform and rural depopulation, Russia's grain belt is predicted to experience significant climate change. In this paper, we describe the ongoing demographic changes and projected regional climate changes based on downscaled climate models for a region in the middle of the Russian grain belt. We visited this region in the summer of 2010 and engaged the local population, including district administrators, farm managers and local residents in extensive interviews. We will describe the agricultural development over the past ten years and explain which climate adaptations we have found that are currently occurring. We observed that some districts have experienced a steeper population decline than any other country in the world. In addition, the elderly dependency ratio is higher than in most of the "older" countries in the world. Downscaled climate models reveal that a minimum temperature increase is more significant than a maximum temperature increase, which has implications important for crop development. In addition, we show that climate models vary highly with respect to the amount of precipitation they project for the region with some models revealing major precipitation declines.

  12. The crust role at Paramillos Altos intrusive belt: Sr and Pb isotope evidence

    International Nuclear Information System (INIS)

    Paramillos Altos Intrusive Belt (PAIB) (Ostera, 1996) is located in the thick skinned folded-thrust belt of Malargue, southwestern Mendoza, Argentina. Geochemical, geochronologic and isotopic studies were carried out in it (Ostera 1996, 1997, Ostera et al. 1999; Ostera et al. 2000) and these previous papers suggested a minor involvement of the crust in the genesis of the PAIB. According with Ostera et al. (2000) it is composed by stocks, laccoliths, dykes and sills which range in composition from diorites to granodiorites, and from andesites to rhyolites, and divided in five Members, which range in age from Middle Miocene to Early Miocene: a- Calle del Yeso Dyke Complex (CYDC), with sills and dykes of andesitic composition (age: 20±2 Ma). b- Puchenque-Atravesadas Intrusive Complex (PAIC), composed by dykes and stocks ranging from diorites to granodiorites (age: 12.5±1 Ma). c- Arroyo Serrucho Stock (SAS), an epizonal and zoned stock, with four facies, with K/Ar and Ar/Ar dates of 10±1 and 9.5±0.5 Ma. d- Portezuelo de los Cerros Bayos (PCB), that includes porphyritic rocks of rhyolitic composition, of 7.5±0.5 Ma. e- Cerro Bayo Vitrophyres (CBV), with andesitic sills and dykes (age: 4.8±0.2 Ma). We present in this paper new Sr and Pb isotopes data that constrain the evolution of the PAIB (au)

  13. Seeking the Middle Way

    Institute of Scientific and Technical Information of China (English)

    Trevor Maisiri

    2011-01-01

    @@ THE involvement of the African Union (AU) in Cote d'Ivoire has indeed further exposed the already entrenched perception of the complexity of conflict mediation processes across the continent.These processes require capacity for contextualization as well as the need for instilled urgency and the AU has thus been faced with such challenges.

  14. A preliminary study of NW Zhejiang foreland fold and thrust belt in Southeast China

    Institute of Scientific and Technical Information of China (English)

    肖文交; 李继亮; 何海清; 陈海泓

    1997-01-01

    The Upper Permian Dalong Formation (P2d) and Changxing Formation (P2c), and the Lower Tri-assic Zhengtang Formation (Tiz) are of deep-water turbidites. The sedimentary features of the NW Zhejiang are of SE-dipping passive continental margin from the Paleozoic to the early Triassic. Together with the foreland molasse basin during the late Triassic (T3w), the tectonics of the NW Zhejiang is characterised by a tectogenesis which took place in the middle Triassic. From SE to NW, the structural style varies from multi-duplex, antiformal stack to imbricate fans, and then to Jura Mountain-type fold zone with fold-style varying gradually from large-scale tight fold to mid-scale chevron fold, then to cylindrical fold, reviewing a preliminary scenario of foreland fold and thrust belt. The space-distributed structures and the tectonic vergence indicate the significance of deformation in (T1-T3).

  15. Late-Neoproterozoic hydrothermal fluid activity in the Tandilia belt, Argentina

    Directory of Open Access Journals (Sweden)

    Juan C Martínez

    2013-09-01

    Full Text Available In the Barker - Villa Cacique area, Tandilia belt, alteration mineral assemblages were studied by petrography, XRD and EMPA at three different stratigraphic levels: (1 a phyllic alteration at the unconformity palaeoproterozoic basement-neoproterozoic sedimentary succession (TLPU; (2 an advanced argillic alteration in the Las Águilas Formation (middle level; and (3 a phyllic alteration on pyroclastic rocks of the Olavarría Formation (upper level. Special emphasize was placed on the chemical characterization of K-white micas and chlorites. Secondary K-white micas of altered migmatites, from the Las Aguilas and Olavarría Formations have a low paragonite content (Na* 9.5 km for the entire sedimentary pile. Hot fluids would rise from deep-seated realms, metamorphic and/or hidden igneous sources. A correlation with a Brasiliano thermo-tectonic event is hypothesized.

  16. Power Transmission Through Timing Belt In Two Wheeler Motors

    Directory of Open Access Journals (Sweden)

    Gurumurthy Veerapathiran

    2015-03-01

    Full Text Available This paper studies the effect of noise and friction on performance of the chain drive system for motor bikes. Experiment shows that chain transmission in chain drive system leads to poor overall performance, due to its noise and chain gets loose due to aging and sprockets wear due to chain friction etc., the proposed system consists of drive and driven pulley with timing belt transmission. Compared to conventional method, proposed method give improved tension in pulleys and belt by the additional arrangement called belt tensioner. This gives good overall performance of the system, and reduces noise, vibration and gives high transmission speed.

  17. Detection of Small Kuiper Belt Objects by Stellar Occultations

    OpenAIRE

    Stevenson, R

    2007-01-01

    Knowledge of the Kuiper Belt is currently limited to those objects that can be detected directly. Objects with diameters less than $\\sim$10km reflect too little light to be detected. These smaller bodies could contain most of the mass in the Kuiper Belt while the abundance of these bodies may constrain the distribution of mass. The overall size distribution of bodies within the Kuiper Belt can also be inferred from the relative abundances of sub-km and larger bodies. Stellar occultations are ...

  18. Middle atmospheric electrodynamics

    Science.gov (United States)

    Kelley, M. C.

    1983-01-01

    A review is presented of the advances made during the last few years with respect to the study of the electrodynamics in the earth's middle atmosphere. In a report of the experimental work conducted, attention is given to large middle atmospheric electric fields, the downward coupling of high altitude processes into the middle atmosphere, and upward coupling of tropospheric processes into the middle atmosphere. It is pointed out that new developments in tethered balloons and superpressure balloons should greatly increase the measurement duration of earth-ionospheric potential measurements and of stratospheric electric field measurements in the next few years. Theoretical work considered provides an excellent starting point for study of upward coupling of transient and dc electric fields. Hays and Roble (1979) were the first to construct a model which included orographic features as well as the classical thunderstorm generator.

  19. Steps to African Development

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The development of Africa is vital to the world’s sustainable development.However,African countries still face key challenges in achieving the meaningful expansion of their economies.At the High-Level Symposium on China-Africa Investment Cooperation in Xiamen,southeast China’s Fujian Province,held from September 8 to 10,Chen Deming,Minister of Commerce of China,elaborates on these challenges and sees

  20. Geomorphic signature of active tectonics in the southern Abruzzi Periadriatic hilly belt (Central Italy)

    Science.gov (United States)

    Racano, Simone; Fubelli, Giandomenico; Centamore, Ernesto; Dramis, Francesco

    2016-04-01

    The geo-structural setting of the southern Abruzzi hilly belt that stretches from the northeastern front of the Maiella Massif to the Adriatic coast is characterized by deep-seated northeast verging thrusts masked by a thick cover of Late Pliocene-Middle Pleistocene marine deposits. Most authors consider this area tectonically inactive while only few of them support the hypothesis of its recent activity from the analysis of the river network pattern. Geological and geomorphological investigations carried out in the area have clearly shown the occurrence of surface deformations resulting from the continued activity of compressive tectonics up to recent times. The analysis of the study area by of a 10 m resolution DTM (using the open-source QGIS software) confirmed and supplemented field observations. Particularly significant in this context is the topographic setting of the alluvial strath terraces in the river valleys that develop transversally to the buried thrusts. In correspondence of these structures, topographic highs have grown up displacing the middle-Pleistocene planation surface developed on top of the hilly belt, from the Maiella piedmont to the coastal zone, and diverting laterally the river courses uphill. In the same places, as along the Alento and Foro rivers that cross by antecedence the grown up topographic highs, the long profiles of terraces bend eastward and the height difference between the terrace orders, essentially related all around the area to the Quaternary regional uplift, strongly increases. In some cases, surficial faults have lowered the terraces into graben troughs or have displaced them until assuming an uphill trend. This recent tectonic activity should be taken in account in assessing the seismic hazard of the study area.

  1. Quiet time enhancements over African latitudes

    Science.gov (United States)

    Orford, Nicola; Katamzi, Zama; Buresova, Dalia

    2016-07-01

    F2 layer disturbances not related to geomagnetic activity are known as quiet time enhancements (QTEs). The phenomenon of QTEs has not yet been studied over African latitudes. We therefore explore the occurrence of QTEs over Africa in order to expand our knowledge on the behaviour of the ionosphere over this region. Several GPS stations in the middle to equatorial latitudes, during the solar minimum (2009) and near solar maximum (2013), are used. This data was examined for possible trends in variation with solar cycle, season and latitude as well as time of commencement of enhancements. Over the southern mid-latitude region of Africa we have observed that the QTEs are more likely to commence during the night in both solar minimum and maximum, however a slightly larger portion of daytime commencements during solar minimum than during solar maximum were observed. The total number of enhancements for the solar minimum period appears greater than during solar maximum. A seasonal trend is seen with the maximum number of enhancements occurring in summer during solar minimum and in winter during solar maximum. We explore further whether these trends are mirrored or different at low latitude/equatorial African regions.

  2. Diversity among African pygmies.

    Science.gov (United States)

    Ramírez Rozzi, Fernando V; Sardi, Marina L

    2010-01-01

    Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D) landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies) were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression) and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies.

  3. Diversity among African pygmies.

    Directory of Open Access Journals (Sweden)

    Fernando V Ramírez Rozzi

    Full Text Available Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies.

  4. Biofuels: The African experience

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo, L.A.; Nkolo, M. [German Agency for Technical Cooperation GTZ, Delegation Regionale des Eaux et Forets, Bertoua (Cameroon)

    2009-07-01

    In July 2006, the African Non-Petroleum Producers Association was formed in Senegal, Africa to develop alternative energy sources. It involved 13 of Africa's poorest nations, who joined forces to become global suppliers of biofuels, and some have set mandatory mixing of ethanol into gasoline. Although several biofuel production projects have been launched in western Africa, many of the new projects and plantations have not yet reached maturity due to the time lag between plantation and full-scale production, which is about 6 years. Major projects that could be producing significant quantities of biofuels in the next few years are not yet reflected in production statistics. Although ethanol is not yet being produced in large quantities in Africa, short-term opportunities exist. Countries in the South African Development Community are using molasses from the sugar can industry to produce ethanol. Biodiesel is also not currently produced on a significant scale in western Africa, but several other countries are gaining experience with cotton and palm oil resources, and Jatropha. Biomass residue also represents a large potential for all African countries involved in timber production. Unlike biodiesel production, land use conflicts are not an issue with biomass residue production.

  5. The Impact of Managerialism on the Strategy Work of University Middle Managers

    Science.gov (United States)

    Davis, Annemarie; Jansen van Rensburg, Mari; Venter, Peet

    2016-01-01

    In an attempt to understand the effects of managerialism on university managers in a developing country, we set out to gather rich data on the strategy work of middle managers through a single case study at a South African university. Managerialism has the potential to solve inefficiencies in university systems and processes, as it could help to…

  6. Parental Choice and the Decision to Decharter an Urban, Black, Middle School

    Science.gov (United States)

    Tonso, Karen L.; Colombo, Marie

    2006-01-01

    This article unpacks the decision to decharter a successful urban middle school serving African American students, especially focusing on parental choice in a school caught between two urban reform initiatives: charter schooling and state takeovers of urban districts. Originally chartered by a university, DeCharter became a "school of choice" in…

  7. Dating Violence & Sexual Harassment across the Bully-Victim Continuum among Middle and High School Students

    Science.gov (United States)

    Espelage, Dorothy L.; Holt, Melissa K.

    2007-01-01

    Associations among bullying, peer victimization, sexual harassment, and dating violence were examined among 684 middle and high school students. Cluster analysis of self-report measures revealed four distinct bully-victim subtypes: uninvolved, victims, bully-victims, and bullies. African-American students comprised the bully cluster more than…

  8. Self-Esteem Changes in the Middle School Years: A Study of Ethnic and Gender Groups

    Science.gov (United States)

    Adams, Sue K.; Kuhn, Jennifer; Rhodes, Jean

    2006-01-01

    The current study investigated how ethnicity and gender affect changes in the self-esteem of early adolescents during the middle school years. Self-report data were collected from more than 4,000 early adolescents from three ethnic groups: European American, African American, and Hispanic and analyzed using a consecutive three-year cross-sectional…

  9. Rescuing Middle School Astronomy

    Science.gov (United States)

    Mayo, L. A.; Janney, D.

    2010-12-01

    There is a crisis in education at the middle school level (Spellings, 2006). Recent studies point to large disparities in middle school performance in schools with high minority populations. The largest disparities exist in areas of math and science. Astronomy has a universal appeal for K-12 students but is rarely taught at the middle school level. When it is taught at all it is usually taught in isolation with few references in other classes such as other sciences (e.g. physics, biology, and chemistry), math, history, geography, music, art, or English. The problem is greatest in our most challenged school districts. With scores in reading and math below national averages in these schools and with most state achievement tests ignoring subjects like astronomy, there is little room in the school day to teach about the world outside our atmosphere. Add to this the exceedingly minimal training and education in astronomy that most middle school teachers have and it is a rare school that includes any astronomy teaching at all. In this presentation, we show how to develop and offer an astronomy education training program for middle school teachers encompassing a wide range of educational disciplines that are frequently taught at the middle school level. The prototype for this program was developed and launched in two of the most challenged and diverse school systems in the country; D.C. Public Schools, and Montgomery County (MD) Public Schools.

  10. Institution Building for African Regionalism

    OpenAIRE

    Khadiagala, Gilbert M.

    2011-01-01

    Since the 1960s, African states have embraced regional integration as a vital mechanism for political cooperation and for pooling resources to overcome problems of small and fragmented economies. In building meaningful institutions for regionalism, however, Africans have faced the challenges of reconciling the diversities of culture, geography, and politics. As a result, African regional institutions are characterized by multiple and competing mandates and weak institutionalization. This stud...

  11. MACRO MODEL OF SEAT BELT USE BY CAR DRIVERS AND PASSENGERS

    Directory of Open Access Journals (Sweden)

    Kazimierz JAMROZ

    2013-12-01

    Full Text Available The article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.

  12. African-Americans and Heart Disease, Stroke

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More African-Americans and Heart Disease, Stroke Updated:Apr 18, ... of getting those diseases are even higher for African-Americans. The good news is, African-Americans can ...

  13. 4 National Standards for Rubber Belt Products Issued

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    On May 20, National General Administration of Quality Supervision, Inspection and Quarantine and National Standardization Administration approved to issue 4 national standards for rubber belt products, which come into effect from October 1.

  14. Face-Saving Devices: Seat Belts and Air Bags

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160032.html Face-Saving Devices: Seat Belts and Air Bags Using ... 11 percent) suffered facial fractures -- nasal and mid-face fractures most often. Those most likely to suffer ...

  15. Periumbilical allergic contact dermatitis: blue jeans or belt buckles?

    Science.gov (United States)

    Byer, Tara T; Morrell, Dean S

    2004-01-01

    Nickel is the most ubiquitous contact allergen among children and adolescents. Metal blue jeans buttons and belts have been noted to cause nickel dermatitis around the umbilicus. For these children, traditional teaching is strict avoidance of all pants with metal snaps/buttons, particularly blue jeans. In this study we tested 90 pairs of blue jeans and 47 belts for nickel using the dimethylglyoxime spot test. Only 10% of blue jeans tested positive, while 53% of belts tested positive. Furthermore, 10 pairs of nickel-negative blue jeans remained negative after 10 washings. Overall we found no resistance to testing in clothing stores. From these results, we recommend that patients with allergic contact dermatitis secondary to nickel need not strictly avoid blue jeans and metal belt buckles. Rather, families should be encouraged to use the dimethylglyoxime spot test to test these items for nickel prior to purchase.

  16. "Abomination"--life as a Bible belt gay.

    Science.gov (United States)

    Barton, Bernadette

    2010-01-01

    Drawing on observation, autoethnography, and audio-taped interviews, this article explores the religious backgrounds and experiences of Bible Belt gays. In the Bible Belt, Christianity is not confined to Sunday worship. Christian crosses, messages, paraphernalia, music, news, and attitudes permeate everyday settings. Consequently, Christian fundamentalist dogma about homosexuality-that homosexuals are bad, diseased, perverse, sinful, other, and inferior-is cumulatively bolstered within a variety of other social institutions and environments in the Bible Belt. Of the 46 lesbians and gay men interviewed for this study (age 18-74 years), most describe living through spirit-crushing experiences of isolation, abuse, and self-loathing. This article argues that the geographic region of the Bible Belt intersects with religious-based homophobia. Informants explained that negative social attitudes about homosexuality caused a range of harmful consequences in their lives including the fear of going to hell, depression, low self-esteem, and feelings of worthlessness.

  17. "Abomination"--life as a Bible belt gay.

    Science.gov (United States)

    Barton, Bernadette

    2010-01-01

    Drawing on observation, autoethnography, and audio-taped interviews, this article explores the religious backgrounds and experiences of Bible Belt gays. In the Bible Belt, Christianity is not confined to Sunday worship. Christian crosses, messages, paraphernalia, music, news, and attitudes permeate everyday settings. Consequently, Christian fundamentalist dogma about homosexuality-that homosexuals are bad, diseased, perverse, sinful, other, and inferior-is cumulatively bolstered within a variety of other social institutions and environments in the Bible Belt. Of the 46 lesbians and gay men interviewed for this study (age 18-74 years), most describe living through spirit-crushing experiences of isolation, abuse, and self-loathing. This article argues that the geographic region of the Bible Belt intersects with religious-based homophobia. Informants explained that negative social attitudes about homosexuality caused a range of harmful consequences in their lives including the fear of going to hell, depression, low self-esteem, and feelings of worthlessness. PMID:20391006

  18. 5m Main Belt Asteroid Population Estimation Using Vesta Imagery

    Science.gov (United States)

    Rynders, Michael; Trilling, David E.

    2016-10-01

    The Main Belt is the largest source of Near-Earth asteroids, but objects 2 pixels in diameter that were counted in a 33km 2 region to give a crater density. By knowing the crater density and making some reasonable assumptions about the orbital distribution of asteroids and the age of Vesta's surface, an estimate of the population of small asteroids in the inner main belt was made. It was found that the inner region of the main asteroid belt contains approximately 20 billion asteroids larger than 5 m. These results agree well with the measured inner Main Belt Size distribution derived by the Wide-field Infrared Survey Explorer, WISE (Masiero et al. 2011).

  19. FORMATION AND EVOLUTION OF THE CENOZOIC THRUST FOLD BELT IN JINPING, SICHUAN

    Institute of Scientific and Technical Information of China (English)

    LIAO Zhongli; DENG Yongfu; LIAO Guangyu

    2003-01-01

    The Jinping orogenic belt in Sichuan, China consists mainly of the Jinpingshan intracontinental thrust-nappe belt, foreland thrust-nappe belt and foreland uplift belt. Based on analyses about the characteristics of the structural units in this area, the authors propose in this paper that Chapuzi-Bazhe revival fault belt is the regional boundary fault, and points out that after the formation of the Pre-Sinian basement, the western edge of the Yangtze paraplatform was turned into the passive continental margin in Sinian to Triassic, then into the Mesozoic collision orogenic belt, and finally into the Cenozoic orogenic belt through intracontinental orogeny.

  20. SPECIFIC RESISTANCE AND SPECIFIC INTENSITY OF BELT SANDING OF WOOD

    Directory of Open Access Journals (Sweden)

    Boleslaw Porankiewicz

    2010-06-01

    Full Text Available This paper examines and discusses the specific belt sanding resistance K (N·cm-2 and specific belt sanding intensity SI (g·cm-2·min-1, for wood of Pinus sylvestris L., Picea abies L., Quercus robra L., Acer pseudoplatanus L., Alnus glutinosa Gaertn., and Populus Nigra L., by different sanding pressure pS, different sanding grit NG number, and different wood grain angles Phi(v.

  1. Tribological Properties of Metal V-Belt Type CVT Lubricant

    OpenAIRE

    Keiichi Narita

    2012-01-01

    The priority for lubricant performance for metal V-belt-type CVT (B-CVTFs) should be the improvement of transmittable torque capacity between the belt and pulley plus excellent antishudder properties for lockup clutch used in B-CVTs. This study intends to investigate the effect of lubricant additives for improving these performances of B-CVTs. In addition, surface analysis techniques were utilized to gain a novel insight into the chemical composites and morphology of the tribofilms. As a resu...

  2. Promoting automobile safety belt use by young children.

    OpenAIRE

    Sowers-Hoag, K M; Thyer, B A; Bailey, J S

    1987-01-01

    A program using behavioral practice, assertiveness training, and social and contrived reinforcers was developed to establish and maintain automobile safety belt use by young children. Sixteen children (ages 4.8 to 7 years) who never used their safety belts during a 5-day preexperimental observation period were randomly assigned to two groups of eight each. A multiple baseline design across groups was used to evaluate the effectiveness of the training program. During the 8-day baseline period ...

  3. Design of MGA trajectories for main belt asteroid

    Institute of Scientific and Technical Information of China (English)

    崔祜涛; 乔栋; 崔平远; 栾恩杰

    2003-01-01

    Asteroid exploration is one of the most sophisticated missions currently being investigated. Gravityassist trajectories have proven valuable in interplanetary missions such as the Pioneer, Voyager and Galileo. In this paper, we design interplanetary trajectory for main belt asteroid exploration mission with the Mars gravityassist (MGA) using "pork chop" plots and patched-conic theory and give some initial valuable trajectory parameters on main belt asteroid exploration mission with MGA.

  4. Evidence of 1.7- to 1.8-Ga Collisional Arc in the Kaoko Belt, NW Namibia

    Science.gov (United States)

    Luft, João Luiz; Chemale, Farid; Armstrong, Richard

    2011-04-01

    Detailed structural and isotopic analyses in the Hoanib and Ugab River Valleys indicate the existence of an exotic 1.7- to 1.8-Ga terrane in the Pan-African Kaoko Belt. This crustal block, called as Mudorib Complex, is imbricated between autochthonous and para-autochthonous rocks of Congo Craton, Kaoko Basin, and Western Kaoko Batholith units during the main tectono-thermal phase of Kaoko Belt collision around 580 Ma, involving the Rio de La Plata, Congo and Kahalari paleoplates. This terrain is positioned between the 1.9-Ga Pruwes Complex units of SW edge of the Congo Craton and the 0.58- to 0.55-Ga Amspoort Suite granitoids of the Western Kaoko Batholith. It is coincident with a regional positive aeromagnetic anomaly trending from NNW in the Ugab region to the Namibia-Angola border. Internally, Mudorib Complex consists in 1.73- to 1.81-Ga tonalitic-trondhjemitic-dioritic-granodioritic sequence of gneisses associated with cogenetic gabbroic and anothositic-gneisses in the core zone of this Pan-African structure. Field relationship and U-Pb zircon and Sm-Nd whole-rock isotope data combined with geochemical information suggest the existence of two rock associations in the Mudorib Complex, namely late Paleoproterozoic tonalitic-trondhjemitic-dioritic-gneisses with island-arc affinity and tholeiitic metabasites of juvenile origin, showing Nd model age of 1.73-2.17 Ga and ɛNd( t) of -2.05-+4.3. This 1.8- to 1.7-Ga complex is also intruded by granitic dykes formed at 1.49-1.50 Ga with Nd model age of 1.75-2.34 Ga during stable tectonic conditions. In addition to widespread Pan-African tectono-metamorphic events, a secondary metamorphic event of ~1.3 Ga is also recognized in the Mudorib rocks, which may be associated with accretion process of the complex to the Paleoproterozoic to Archean nucleus of the Kaoko Belt in the Hoanib River Valley.

  5. Occultation Searches for Kuiper Belt Objects

    CERN Document Server

    Cooray, A R; Cooray, Asantha; Farmer, Alison J.

    2003-01-01

    The occultation of background stellar sources by foreground Kuiper Belt Objects (KBOs) can be used to survey physical properties of the KBO population. We discuss statistics related to a KBO occultation survey, such as the event duration distribution, and suggest that occultation searches can be effectively used to probe the KBO size distribution below 10 km. In particular, we suggest that occultation surveys may be best suited to search for a turnover radius in the KBO size distribution due to collisions between small-size objects. For occultation surveys that monitor stellar sources near the ecliptic over a few square degrees, with time sampling intervals of order 0.1 sec and sensitivity to flux variations of a few percent or more, a turnover radius between 0.1 and 1.0 km can be probed. While occultation surveys will probe the low-radius limit and imaging surveys will detect KBOs of size 100 km or more, statistics of objects with sizes in the intermediate range of around 1 km to 100 km will likely remain un...

  6. Orion revisited III. The Orion Belt population

    CERN Document Server

    Kubiak, K; Bouy, H; Sarro, L M; Ascenso, J; Burkert, A; Forbrich, J; Großschedl, J; Hacar, A; Hasenberger, B; Lombardi, M; Meingast, S; Köhler, R; Teixeira, P S

    2016-01-01

    This paper continues our study of the foreground population to the Orion molecular clouds. The goal is to characterize the foreground population north of NGC 1981 and to investigate the star formation history in the large Orion star-forming region. We focus on a region covering about 25 square degrees, centered on the $\\epsilon$ Orionis supergiant (HD 37128, B0\\,Ia) and covering the Orion Belt asterism. We used a combination of optical (SDSS) and near-infrared (2MASS) data, informed by X-ray (\\textit{XMM-Newton}) and mid-infrared (WISE) data, to construct a suite of color-color and color-magnitude diagrams for all available sources. We then applied a new statistical multiband technique to isolate a previously unknown stellar population in this region. We identify a rich and well-defined stellar population in the surveyed region that has about 2\\,000 objects that are mostly M stars. We infer the age for this new population to be at least 5\\, Myr and likely $\\sim10$\\,Myr and estimate a total of about 2\\,500 mem...

  7. Detecting Mass Loss in Main Belt Asteroids

    Science.gov (United States)

    Sandberg, Erik; Rajagopal, Jayadev; Ridgway, Susan E.; Kotulla, Ralf C.; Valdes, Francisco; Allen, Lori

    2016-01-01

    Sandberg, E., Rajagopal, J., Ridgway, S.E, Kotulla, R., Valdes, F., Allen, L.The Dark Energy Camera (DECam) on the 4m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) is being used for a survey of Near Earth Objects (NEOs). Here we attempt to identify mass loss in main belt asteroids (MBAs) from these data. A primary motivation is to understand the role that asteroids may play in supplying dust and gas for debris disks. This work focuses on finding methods to automatically pick out asteroids that have qualities indicating possible mass loss. Two methods were chosen: looking for flux above a certain threshold in the asteroid's radial profile, and comparing its PSF to that of a point source. After sifting through 490 asteroids, several have passed these tests and should be followed up with a more rigorous analysis.Sandberg was supported by the NOAO/KPNO Research Experience for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829)

  8. Dark nebulae, dark lanes, and dust belts

    CERN Document Server

    Cooke, Antony

    2012-01-01

    As probably the only book of its type, this work is aimed at the observer who wants to spend time with something less conventional than the usual fare. Because we usually see objects in space by means of illumination of one kind or another, it has become routine to see them only in these terms. However, part of almost everything that we see is the defining dimension of dark shading, or even the complete obscuration of entire regions in space. Thus this book is focused on everything dark in space: those dark voids in the stellar fabric that mystified astronomers of old; the dark lanes reported in many star clusters; the magical dust belts or dusty regions that have given so many galaxies their identities; the great swirling 'folds' that we associate with bright nebulae; the small dark feature detectable even in some planetary nebulae; and more. Many observers pay scant attention to dark objects and details. Perhaps they are insufficiently aware of them or of the viewing potential they hold, but also it may be...

  9. Depositional environment and provenance of Middle Siwalik sediments in Tista valley, Darjiling District, Eastern Himalaya, India

    Indian Academy of Sciences (India)

    Abhik Kundu; Abdul Matin; Malay Mukul

    2012-02-01

    The frontal part of the active, wedge-shaped Indo-Eurasian collision boundary is defined by the Himalayan fold-and-thrust belt whose foreland basin accumulated sediments that eventually became part of the thrust belt and is presently exposed as the sedimentary rocks of the Siwalik Group. The rocks of the Siwalik Group have been extensively studied in the western and Nepal Himalaya and have been divided into the Lower, Middle and Upper Subgroups. In the Darjiling–Sikkim Himalaya, the Upper Siwalik sequence is not exposed and the Middle Siwalik Subgroup exposed in the Tista river valley of Darjiling Himalaya preserves a ∼325 m thick sequence of sandstone, conglomerate and shale. The Middle Siwalik section has been repeated by a number of north dipping thrusts. The sedimentary facies and facies associations within the lithostratigraphic column of the Middle Siwalik rocks show temporal repetition of sedimentary facies associations suggesting oscillation between proximal-, mid- and distal fan setups within a palaeo-alluvial fan depositional environment similar to the depositional setup of the Siwalik sediments in other parts of the Himalaya. These oscillations are probably due to a combination of foreland-ward movement of Himalayan thrusts, climatic variations and mountain-ward shift of fanapex due to erosion. The Middle Siwalik sediments were derived from Higher- and Lesser Himalayan rocks. Mineral characteristics and modal analysis suggest that sedimentation occurred in humid climatic conditions similar to the moist humid climate of the present day Eastern Himalaya.

  10. Forming the Cold Classical Kuiper Belt in a light Disk

    CERN Document Server

    Shannon, Andrew; Lithwick, Yoram

    2015-01-01

    Large Kuiper Belt Objects are conventionally thought to have formed out of a massive planetesimal belt that is a few thousand times its current mass. Such a picture, however, is incompatible with multiple lines of evidence. Here, we present a new model for the conglomeration of Cold Classical Kuiper belt objects, out of a solid belt only a few times its current mass, or a few percent of the solid density in a Minimum Mass Solar Nebula. This is made possible by depositing most of the primordial mass in grains of size centimetre or smaller. These grains collide frequently and maintain a dynamically cold belt out of which large bodies grow efficiently: an order-unity fraction of the solid mass can be converted into large bodies, in contrast to the ~0.1% efficiency in conventional models. Such a light belt may represent the true outer edge of the Solar system, and it may have effectively halted the outward migration of Neptune. In addition to the high efficiency, our model can also produce a mass spectrum that pe...

  11. Lithospheric seismic fabrics of Sulu ultrahigh-pressure metamorphic belt

    Institute of Scientific and Technical Information of China (English)

    YANG; Wencai; YANG; Wuyang; JIN; Zhenmin; CHENG; Zhenyan

    2005-01-01

    Calibration of seismic reflectors appearing in the crust of the Chinese continent scientific drilling site can be completed through the correlation studies between direct evidences, such as the drill cores, and geophysical signatures; therefore the interpretation of geophysical data could produce reliable results of crustal structure and composition. On the other hand, there are two Cenozoic volcanoes close to the scientific drilling site; analyzing composition of xenoliths existent in the volcanoes and evaluating their seismic velocities can also offer information about the mantle and lower crust. After the calibration via cores and well-logging data, the seismic reflectors appearing in the UHP belt can be caused by lithological changes within the UHP rock slice, ductile shearing rock-suites, and later fracture zones. Among these sources, ductile shearing resulted in displacement and detachment of original rock-sheets, producing some rock-interbeds of several hundred meters thick that are named the ductile shearing rock-suites. A suite consists of mylonized gneiss and eclogite slices that underwent shearing, becoming the major mechanism responsible to generate regional strong reflections. The UHP rock-slice is characterized by complicated structures and high density, high seismic velocity and high electrical resistivity, its thickness is usually less than 11 km. Velocity and density of the gneiss-layer beneath gradually tend to normal with increasing depth. Based on the xenoliths we can infer that the middle crust contains a lot of gneisses, and the lower crust consists of different granulites. The lithospheric mantle has multi-layer structures and consists mainly of spinal lherzolite and harzburgite, implying late Mesozoic lithospheric thinning. The seismic fabrics with different origins were possible products of different geodynamic processes. For instance, the UHP rock-slice was produced by the UHP metamorphic process and the exhumation of subducted

  12. The African Diaspora, Civil Society and African Integration

    DEFF Research Database (Denmark)

    Opoku-Mensah, Paul Yaw

    This paper, a work-in-progress, makes a contribution to the discussions on the appropriate modalities for incorporating the African diaspora in the African integration project.  It argues that the most appropriate entry points for incorporating the African diaspora into the integration project...... might not, necessarily, be in the formal political structures, although this is important. To the contrary, the most effective and sustainable might be within civil society---that is the links between the peoples and organizations of Africa and the diaspora. Using the case of the African academy-- as an...... institution of civil society--- the paper outlines a conceptual framework for incorporating the diaspora into the African integration project....

  13. Middle managers service leadership

    Directory of Open Access Journals (Sweden)

    Lucio Roberto Lescano Duncan

    2011-12-01

    Full Text Available A big challenge in modern service organization is to focus on customers and to forge their satisfaction and loyalty. Innovation, information technology and value added are decisive factors, however the main aspect to consider is the human factor. It is necessary to focus on people in order to improve the service capability within the organization.Middle manager is the link between the strategy designed by top management and the execution to deliver services, that is realized by employees guided by leaders of middle level. Our study is focused on middle manager service orientation as the pillar to get a customer focus and to forge the service employees' performance.We consider that middle managers have to asume a service leadership in order to foster the productivity and employees' commitment. In that sense we focus especially on middle managers' main roles. Those are the key aspect to deploy a service culture, and at the same time to promote employees' satisfaction that drives their performance and development.

  14. Deformation geometry and timing of theWupoer thrust belt in the NE Pamir and its tectonic implications

    Science.gov (United States)

    Cheng, Xiaogan; Chen, Hanlin; Lin, Xiubin; Yang, Shufeng; Chen, Shenqiang; Zhang, Fenfen; Li, Kang; Liu, Zelin

    2016-09-01

    The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau's tectonic evolution. Here we present new findings on the deformation geometry and timing of the Wupoer thrust belt at the northeastern margin of Pamir. Field investigations and interpretations of seismic profiles indicate that the eastern portion of the Wupoer thrust belt is dominated by an underlying foreland basin and an overlying piggy-back basin. A regional unconformity occurs between the Pliocene (N2) and the underlying Miocene (N1) or Paleogene (Pg) strata associated with two other local unconformities between Lower Pleistocene (Q1) and N2 and between Middle Pleistocene (Q2-4) and Q1 strata. Results of structural restorations suggest that compressional deformation was initiated during the latest Miocene to earliest Pliocene, contributing a total shortening magnitude of 48.6 km with a total shortening rate of 48.12%, most of which occurred in the period from the latest Miocene to earliest Pliocene. These results, combined with previous studies on the Kongur and Tarshkorgan extensional system, suggest an interesting picture of strong piedmont compressional thrusting activity concurrent with interorogen extensional rifting. Combining these results with previously published work on the lithospheric architecture of the Pamir, we propose that gravitational collapse drove the formation of simultaneous extensional and compressional structures with a weak, ductile middle crustal layer acting as a décollement along which both the extensional and compressional faults merged.

  15. Structural inversion of the Tamworth Belt: Insights into the development of orogenic curvature in the southern New England Orogen, Australia

    Science.gov (United States)

    Phillips, G.; Robinson, J.; Glen, R.; Roberts, J.

    2016-05-01

    The middle to late Permian Hunter Bowen Event is credited with the development of orogenic curvature in the southern New England Orogen, yet contention surrounds the structural dynamics responsible for the development of this curvature. Debate is largely centred on the roles of orogen parallel strike-slip and orogen normal extension and contraction to explain the development of curvature. To evaluate the dynamic history of the Hunter Bowen Event, we present new kinematic reconstructions of the Tamworth Belt. The Tamworth Belt formed as a Carboniferous forearc basin and was subsequently inverted during the Hunter Bowen Event. Kinematic reconstructions of the Tamworth Belt are based on new maps and cross-sections built from a synthesis of best-available mapping, chronostratigraphic data and new interpretations of depth-converted seismic data. The following conclusions are made from our study: (i) the Hunter Bowen Event was dominantly driven by margin normal contraction (east-west shortening; present-day coordinates), and; (ii) variations in structural style along the strike of the Tamworth Belt can be explained by orthogonal vs. oblique inversion, which reflects the angular relationship between the principal shortening vector and continental-arc margin. Given these conclusions, we suggest that curvature around the controversial Manning Bend was influenced by the presence of primary curvature in the continental margin, and that the Hastings Block was translated along a sinistral strike-slip fault system that formed along this oblique (with respect to the regional east-west extension and convergence direction) part of the margin. Given the available temporal data, the translation of the Hastings Block took place in the Early Permian (Asselian) and therefore preceded the Hunter Bowen Event. Accordingly, we suggest that the Hunter Bowen Event was dominantly associated with enhancing curvature that was either primary in origin, or associated with fault block translation

  16. African Conservation Tillage Network Website

    OpenAIRE

    African Conservation Tillage Network (ACT)

    2009-01-01

    Metadata only record Maintained by the African Conservation Tillage Network (ACT), this website provides information on Conservation Agriculture in an African context and gathered by stakeholders (NGOs) native to the continent. Resources on projects, practices, reports, and training courses are provided.

  17. African Diaspora Associations in Denmark

    DEFF Research Database (Denmark)

    Vammen, Ida Marie; Trans, Lars Ove

    2011-01-01

    Since the early 1990s, an increasing number of African migrants have come to Denmark, where they have formed a large number of migrant associations. This chapter presents selected findings from a comprehensive survey of African diaspora associations in Denmark and focuses specifically on their...

  18. Factors that influence rural African American males' aspirations to attend college

    Science.gov (United States)

    Stuart, Alesia K.

    This study was conducted to research factors which influence rural African American males in their college attendance decision. The study was an attempt to discover specific influences in the higher education pursuit from aspiration to enrollment. As African American males and low income students represent lower enrollment figures in higher education, this study attempts to provide research which may improve these numbers. The literature which provides the theoretical frame is related to Hossler (et al., 1999) and his research entitled Going to College. Hossler's study recommended additional research to study African American males. Hossler concluded this participant segment was influenced by different factors than the majority of study participants. This qualitative study includes student interviews. Three high schools in three counties in the Black Belt of rural Alabama were the sites selected for participants. Thirty African American male seniors' responses were transcribed and coded to identify themes related to influences stated by the participants. The students' voices provided insight into their college enrollment pursuit. The findings indicate rural students lack the resources and academic preparation significant for higher education admission. African American males in rural Alabama tend to be first generation students and lack information important to college enrollment. The rural high schools lack the personnel, college and career guidance to ensure participants are aware and prepared to traverse the process of college enrollment. This study identifies policy development needs to address inadequacies that African American males attending rural schools encounter during secondary enrollment. Research participants state college aspirations. Problems arise as participants move from the aspiration stage toward enrollment. Several factors will limit higher education opportunities for the participants. Inadequate knowledge on ACT scores, college cost financial

  19. Booster for African Economy

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China’s investment is fueling African growth SINCE 2000,driven by the Forum on China-Africa Cooperation,China’s foreign direct investment(FDI) in Africa has been growing rapidly.In the face of the global financial crisis,which led to global FDI flows falling,China’s investment in Africa has been on a steady, upbeat rise without any interruption.In 2009,China’s direct investment in Africa reached $1.44 billion,of which nonfinancial direct investment soared by 55.4 percent from the previous year.Africa

  20. Understanding the Rise of African Business

    DEFF Research Database (Denmark)

    Jorem, Kaja Tvedten; Jeppesen, Søren; Hansen, Michael W.

    In light of recent enthusiasm over the African private sector, this paper reviews the existing empirical literature on successful African enterprises and proposes an analytical framework for understanding African firm success. Overall, it is argued that we need to develop an understanding...... of African firm strategy and performance that takes into account the specificities of the African business environment and African firm capabilities. The paper starts by juxtaposing the widespread pessimistic view of African business with more recent, optimistic studies on African firms’ performance....... The latter suggests that profound improvements in African business performance are indeed under way: with the private sector playing a more important role as an engine of growth, with the rise of a capable African entrepreneurial class, and with the emergence of dynamic and competitive African enterprises...

  1. Delivery of meteorites from the asteroid belt

    Science.gov (United States)

    Nolan, Michael Craig

    The process of the delivery of meteorites to the surface of the Earth from plausible source regions such as the asteroid belt is currently understood in general terms, but important uncertainties and conflicts remain to be resolved. Stochastic effects of the rare disruptions of large asteroids on the population of meteorite-sized Earth-crossing asteroids can change the flux and the proportions of compositional types in the infalling meteorite population. These changes can be significant in magnitude over timescales of 108 years. Changes of the order of 1 percent can be expected on timescales of 105-106 y, consistent with small differences between the Antarctic meteorites and modern falls. The magnitude of changes depends strongly on poorly-understood details of collisions. Asteroids 961 Gaspra and 243 Ida were recently imaged by the Galileo spacecraft. I use a numerical hydrocode model to examine the outcomes of various sire impacts into targets the sizes of these asteroids. A shock wave fractures the asteroid in advance of crater excavation flow; thus, for impactors larger than 100 m, impacting at 5.3 km s-1, tensile strength is unimportant in these bodies, whether they are initially intact or are 'rubble piles'. Because of the shock-induced fracture, impact results are controlled by gravity. Therefore these asteroids are much more resistant to catastrophic disruption than predicted by previous estimates, which had assumed that strength was controlling these processes for rock targets. Fracture of km-size asteroids is different from fracture in terrestrial experiments using few-cm targets. The composition distribution of delivered meteorites depends on the outcomes of such asteroid impacts.

  2. Activating main belt comets by collisions

    Science.gov (United States)

    Maindl, T. I.; Haghighipour, N.; Schäfer, C.; Speith, R.

    2016-02-01

    Since their identification as a new class of bodies by Hsieh and Jewitt in 2006 active asteroids (or Main Belt Comets, MBCs) have attracted a great deal of interest. Given that sublimation of volatile material (presumably water-ice) drives MBC activity, these bodies are probable candidates for delivering a significant amount of Earth's water. Dynamical studies suggest in-situ formation of MBCs as the remnants of the break-up of large icy asteroids. Also, collisions between MBCs and small objects might have exposed sub-surface water-ice triggering the cometary activity of these bodies. In order to advance the effort of understanding the nature of MBC activation, we have investigated these collision processes by simulating the impacts in detail using a smooth particle hydrodynamics (SPH) approach that includes material strength and fracture models. Our simulations cover a range of impact velocities (between 0.5 km/s and 5.3 km/s) and angles, allowing m-sized impactors to erode enough of an MBC's surface to expose volatiles and trigger its activation. We also varied the material strength of the active asteroid's surface to study its influence on crater depths and shapes. As expected, depending on the impact energy, impact angle, and MBC's material strength we observe different crater depths. Across all scenarios however, our results show that the crater depths do not exceed a few meters. This implies that if the activity of MBCs is due to sublimating water-ice, ice has to exist in no deeper than a few meters from the surface.

  3. World review: Middle East

    International Nuclear Information System (INIS)

    The article gives information on contracts announced (and to whom) and recently completed in some parts of the Middle East in the petroleum, natural gas and petrochemicals industries. Areas specifically mentioned are Bahrain, Egypt, Iran, Libya, Oman, Qatar, Saudi Arabia, Syria and the United Arab Emirates. The prospects for the petrochemical industry in particular are good and continued growth is expected. Gas is likely to make an increasingly important contribution to the prosperity of the Middle East and is expected to carry a higher priority than expansion of crude oil production

  4. Bioenergy and African transformation.

    Science.gov (United States)

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.

  5. Digital Spectra and Analysis of Altitudinal Belts in Tianshan Mountains,China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Baiping; MO Shenguo; WU Hongzhi; XIAO Fei

    2004-01-01

    Based on the framework of the geo-info spectra of montane altitudinal belts, this paper firstly reviews six classification systems for the spectra of mountain altitudinal belts in China and considers that detailed regional study of altitudinal belts is the key for reaching standardization and systemization of mountain altitudinal belts. Only can this furtheridentify and resolve problems with the study of altitudinal belts. The factors forming the spectra of altitudinal belts are analyzed in the Tianshan Mountains of China, and a digital altitudinal belt system is constructed for the northern flank, Southern flank, the heartland, and Ilivalley in the west. The characteristics of each belt are revealed with a summarization of the pattern of areal differentiation of altitudinal belts.

  6. Evidences for multiple remagnetization of Proterozoic dykes from Iguerda inlier (Anti-Atlas Belt, Southern Morocco)

    Science.gov (United States)

    Neres, Marta; Silva, Pedro F.; Ikene, Moha; Martins, Sofia; Hafid, Ahmid; Mata, João; Almeida, Francisco; Youbi, Nasrrddine; Boumehdi, Ahmed

    2016-04-01

    Paleomagnetic data able to constrain the paleoposition of the West African Craton (WAC) during Paleo-Mesoproterozoic are absent, mainly due to gaps on the sedimentary record and intense remagnetizations. Dykes that intrude several Proterozoic inliers of WAC in the Anti-Atlas Belt (southern Morocco) have recently been subjected to geochronological studies, which revealed ages between Paleoproterozoic and early Neoproterozoic. Therefore, these dykes represent a window of opportunity for paleomagnetic studies aiming to infer about the paleoposition of WAC during Proterozoic. On this scope we conducted a paleomagnetic study on seven Proterozoic dykes of the Iguerda inlier. We determined the paleomagnetic directions and evaluated their meaning by rock magnetic and mineral analyses, complemented by petrographic observations. Results revealed that these rocks record the presence of a complex history of remagnetization events, mostly assigned to several Phanerozoic thermal/chemical events. In particular, we found components assigned to the late stages of Pan African orogeny (s.l.), to the Late Carboniferous Variscan orogeny, and to more recent events. The recognized remagnetization processes are related to widespread metamorphic events under greenschist facies followed by low-temperature oxidation, both responsible for the formation of new magnetic phases (magnetite and hematite). The primary (magmatic) thermo-remanent magnetization of the dykes was obliterated during these events through multiple thermal and chemical remagnetizations. For only one dyke the presence of primary magnetization is possible to infer, though not to confirm, and would place WAC at an equatorial position around 1750 Ma. The authors wish to acknowledge FCT (Portugal) - CNRST (Morocco) bilateral agreement for its major contribution without which this work wouldn't be possible. Publication supported by project FCT UID/GEO/50019/2013 - Instituto Dom Luiz.

  7. The Lord’s Resistance Army: an African Terrorist Group?

    OpenAIRE

    Emma Leonard

    2011-01-01

    The years since 9/11 have been characterised by the increasing threat of terrorist action in the  Middle East and South Asia. Yet Sub-Saharan Africa was has also become a region of concern. In 1998, it had been the scene of two Al-Qaeda attacks against US embassies; besides Africa is home to large Muslim populations. Since 9/11 African violent non-state groups unrelated to Al- Qaeda or to the wider Islamist movement have been recast as terrorist organisations. These groups primarily oper...

  8. Seismicity of the Earth 1900-2013 East African Rift

    Science.gov (United States)

    Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio

    2014-01-01

    The East African Rift system (EARS) is a 3,000-km-long Cenozoic age continental rift extending from the Afar triple junction, between the horn of Africa and the Middle East, to western Mozambique. Sectors of active extension occur from the Indian Ocean, west to Botswana and the Democratic Republic of the Congo (DRC). It is the only rift system in the world that is active on a continent-wide scale, providing geologists with a view of how continental rifts develop over time into oceanic spreading centers like the Mid-Atlantic Ridge.

  9. Middle East Reform Halts

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The chaos in Iraq poses a great threat to the U.S. plan in the Middle East While the fighting between Israel and Lebanon-based Hezbollah becomes fiercer, security in Iraq also keeps deteriorating, making the region a petrol can that may blow up anytime.

  10. Fostering a Middle Class

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Though there is no official definition of "middle class" in China, the tag has become one few Chinese people believe they deserve anyway.In early August, the Chinese Academy of Social Sciences released a report on China’s urban development,

  11. Utopia Middle School

    Science.gov (United States)

    Cloud, Michelle

    2006-01-01

    The following excerpt allows the reader to briefly peer into an ideal school setting: For the purposes of this paper, the fictitious school will be named Utopia Middle School or U.M.S. U.M.S embodies and exemplifies the perfect school. At U.M.S., the campus administrators perform at a level of excellence that motivates, empowers and supports all…

  12. Model Middle Schools

    Science.gov (United States)

    Shapiro, Arthur; And Others

    1973-01-01

    Provides three models as approaches to organizing the middle school in a variety of exciting ways: (1) an oscillating system, where students in communities move between basic studies and related arts and physical education, (2) an immersion system, where students in communities spend full time moving between interdisciplinary areas, and (3) a…

  13. A Physical Model of Electron Radiation Belts of Saturn

    Science.gov (United States)

    Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.

    2012-04-01

    Radiation belts causes irreversible damages on on-board instruments materials. That's why for two decades, ONERA proposes studies about radiation belts of magnetized planets. First, in the 90's, the development of a physical model, named Salammbô, carried out a model of the radiation belts of the Earth. Then, for few years, analysis of the magnetosphere of Jupiter and in-situ data (Pioneer, Voyager, Galileo) allow to build a physical model of the radiation belts of Jupiter. Enrolling on the Cassini age and thanks to all information collected, this study permits to adapt Salammbô jovian radiation belts model to the case of Saturn environment. Indeed, some physical processes present in the kronian magnetosphere are similar to those present in the magnetosphere of Jupiter (radial diffusion; interaction of energetic electrons with rings, moons, atmosphere; synchrotron emission). However, some physical processes have to be added to the kronian model (compared to the jovian model) because of the particularity of the magnetosphere of Saturn: interaction of energetic electrons with neutral particles from Enceladus, and wave-particle interaction. This last physical process has been studied in details with the analysis of CASSINI/RPWS (Radio and Plasma Waves Science) data. The major importance of the wave particles interaction is now well known in the case of the radiation belts of the Earth but it is important to investigate on its role in the case of Saturn. So, importance of each physical process has been studied and analysis of Cassini MIMI-LEMMS and CAPS data allows to build a model boundary condition (at L = 6). Finally, results of this study lead to a kronian electrons radiation belts model including radial diffusion, interactions of energetic electrons with rings, moons and neutrals particles and wave-particle interaction (interactions of electrons with atmosphere particles and synchrotron emission are too weak to be taken into account in this model). Then, to

  14. Evolution of the Bhandara-Balaghat granulite belt along the southern margin of the Sausar Mobile Belt of central India

    Indian Academy of Sciences (India)

    H M Ramachandra; Abhinaba Roy

    2001-12-01

    The Bhandara-Balaghat granulite (BBG) belt occurs as a 190 km long, detached narrow, linear, NE-SW to ENE-WSW trending belt that is in tectonic contact on its northern margin with the Sausar Group of rocks and is bordered by the Sakoli fold belt in the south. The Bhandara part of the BBG belt is quite restricted, comprising a medium to coarse grained two-pyroxene granulite body that is of gabbroic composition and preserves relic igneous fabric. The main part of the belt in Arjuni-Balaghat section includes metasedimentary (quartzite, BIF, Al- and Mg-Al metapelites) and metaigneous (metaultramafic, amphibolite and two-pyroxene granulite) protoliths interbanded with charnockite and charnockitic gneiss. These rocks, occurring as small bands and enclaves within migmatitic and granitic gneisses, show polyphase deformation and metamorphism. Geochemically, basic compositions show tholeiitic trend without Fe-enrichment, non-komatitic nature, continental affinity and show evolved nature. Mineral parageneses and reaction textures in different rock compositions indicate early prograde, dehydration melt forming reactions followed by orthopyroxene stability with or without melt. Coronitic and symplectitic garnets have formed over earlier minerals indicating onset of retrograde IBC path. Evidences for high temperature ductile shearing are preserved at places. Retrogressive hydration events clearly post-date the above paths. The present study has shown that the BBG belt may form a part of the Bastar Craton and does not represent exhumed oceanic crust of the Bundelkhand Craton. It is further shown that rocks of the BBG belt have undergone an earlier high-grade granulite metamorphism at 2672 ± 54 Ma (Sm-Nd age) and a post-peak granulite metamorphism at 1416 ± 59 Ma (Sm-Nd age, 1380 ± 28 Ma Rb-Sr age). These events were followed by deposition of the Sausar supracrustals and Neoproterozoic Sausar orogeny between 973 ± 63 Ma and 800 ± 16 Ma (Rb-Sr ages).

  15. Court stories in selected African short narratives

    OpenAIRE

    E. Yewah

    1994-01-01

    This article attempts to cross-examine African Literature and African costumary, Islamic and inherited colonial laws. It opens a new topic in the study of African literature by showing how legal discourses are inscribed in certain African narratives and how these discourses link the narratives to the overall context of their production.

  16. 2002 Sino-African SHP Training Workshop

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The 2002 Sino-African SHP Training Workshop was held from 10 May to 18 June 2002 at Hangzhou Regional Center for Small Hydro Power(HRC). Attended altogether 9 participants from 5 African countries, i.e. Burundi, Nigeria, South African, Tanzania and Tunisia. This is the second training workshop on SHP that HRC conducted for African countries.

  17. Assimilation Differences among Africans in America.

    Science.gov (United States)

    Dodoo, F. Nii-Amoo

    1997-01-01

    Census data (1990) indicate that male African immigrants earn more than their Caribbean-born counterparts or native-born African Americans, but controlling for relevant earnings-related endowments erases the African advantage and elevates Caribbean earnings above those of the other groups. Also, African (but not Caribbean) university degree…

  18. Mantle Response to Collision, Slab Breakoff & Lithospheric Tearing in Anatolian Orogenic Belts, and Cenozoic Geodynamics of the Aegean-Eastern Mediterranean Region

    Science.gov (United States)

    Dilek, Yildirim; Altunkaynak, Safak

    2010-05-01

    The geochemical and temporal evolution of the Cenozoic magmatism in the Aegean, Western Anatolian and peri-Arabian regions shows that plate tectonic events, mantle dynamics, and magmatism were closely linked in space and time. The mantle responded to collision-driven crustal thickening, slab breakoff, delamination, and lithospheric tearing swiftly, within geologically short time scales (few million years). This geodynamic continuum resulted in lateral mantle flow, whole-sale extension and accompanying magmatism that in turn caused the collapse of tectonically and magmatically weakened orogenic crust. Initial stages of post-collisional magmatism (~45 Ma) thermally weakened the orogenic crust in Tethyan continental collision zones, giving way into large-scale extension and lower crustal exhumation via core complex formation starting around 25-23 Ma. Slab breakoff was the most common driving force for the early stages of post-collisional magmatism in the Tethyan mountain belts in the eastern Mediterranean region. Magmatic rocks produced at this stage are represented by calc-alkaline-shoshonitic to transitional (in composition) igneous suites. Subsequent lithospheric delamination or partial convective removal of the sub-continental lithospheric mantle in collision-induced, overthickened orogenic lithosphere caused decompressional melting of the upwelling asthenosphere that in turn resulted in alkaline basaltic magmatism (punctuated by the collisional accretion of several ribbon continents (i.e. Pelagonia, Sakarya, Tauride-South Armenian) to the southern margin of Eurasia, and by related slab breakoff events. Exhumation of middle to lower crustal rocks and the formation of extensional metamorphic domes occurred in the backarc region of this progressively southward-migrated trench and the Tethyan (Afro-Arabian) slab throughout the Cenozoic. Thus, slab retreat played a major role in the Cenozoic geodynamic evolution of the Aegean and Western Anatolian regions. However

  19. Rotationally driven 'zebra stripes' in Earth's inner radiation belt.

    Science.gov (United States)

    Ukhorskiy, A Y; Sitnov, M I; Mitchell, D G; Takahashi, K; Lanzerotti, L J; Mauk, B H

    2014-03-20

    Structured features on top of nominally smooth distributions of radiation-belt particles at Earth have been previously associated with particle acceleration and transport mechanisms powered exclusively by enhanced solar-wind activity. Although planetary rotation is considered to be important for particle acceleration at Jupiter and Saturn, the electric field produced in the inner magnetosphere by Earth's rotation can change the velocity of trapped particles by only about 1-2 kilometres per second, so rotation has been thought inconsequential for radiation-belt electrons with velocities of about 100,000 kilometres per second. Here we report that the distributions of energetic electrons across the entire spatial extent of Earth's inner radiation belt are organized in regular, highly structured and unexpected 'zebra stripes', even when the solar-wind activity is low. Modelling reveals that the patterns are produced by Earth's rotation. Radiation-belt electrons are trapped in Earth's dipole-like magnetic field, where they undergo slow longitudinal drift motion around the planet because of the gradient and curvature of the magnetic field. Earth's rotation induces global diurnal variations of magnetic and electric fields that resonantly interact with electrons whose drift period is close to 24 hours, modifying electron fluxes over a broad energy range into regular patterns composed of multiple stripes extending over the entire span of the inner radiation belt. PMID:24646996

  20. JOVIAN EARLY BOMBARDMENT: PLANETESIMAL EROSION IN THE INNER ASTEROID BELT

    Energy Technology Data Exchange (ETDEWEB)

    Turrini, D.; Coradini, A.; Magni, G., E-mail: diego.turrini@ifsi-roma.inaf.it [Istituto di Astrofisica e Planetologia Spaziali, INAF-IAPS, Via Fosso del Cavaliere 100, 00133, Rome (Italy)

    2012-05-01

    The asteroid belt is an open window on the history of the solar system, as it preserves records of both its formation process and its secular evolution. The progenitors of the present-day asteroids formed in the Solar Nebula almost contemporary to the giant planets. The actual process producing the first generation of asteroids is uncertain, strongly depending on the physical characteristics of the Solar Nebula, and the different scenarios produce very diverse initial size-frequency distributions (SFDs). In this work, we investigate the implications of the formation of Jupiter, plausibly the first giant planet to form, on the evolution of the primordial asteroid belt. The formation of Jupiter triggered a short but intense period of primordial bombardment, previously unaccounted for, which caused an early phase of enhanced collisional evolution in the asteroid belt. Our results indicate that this Jovian Early Bombardment caused the erosion or the disruption of bodies smaller than a threshold size, which strongly depends on the SFD of the primordial planetesimals. If the asteroid belt was dominated by planetesimals less than 100 km in diameter, the primordial bombardment would have caused the erosion of bodies smaller than 200 km in diameter. If the asteroid belt was instead dominated by larger planetesimals, the bombardment would have resulted in the destruction of bodies as big as 500 km.

  1. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  2. Firm Productivity and Investment Climate in Developing Countries: How Does Middle East and North Africa Manufacturing Perform?

    OpenAIRE

    Plane, Patrick; Veganzones, Marie-Ange; Kinda, Tidiane

    2011-01-01

    Firm productive performances in five Middle East and North African (MENA) economies and eight manufacturing industries are compared to those in 17 other developing countries. Although the broad picture hides some heterogeneity, enterprises in MENA often performed inadequately compared to MENA status of middle-income economies, with the exception of Morocco and, to some extent, Saudi Arabia. Firm competitiveness is a more constant constraint, with a unit labor cost higher than in most competit...

  3. Policy co-ordination and growth traps in a middle-income country setting: The case of South Africa

    OpenAIRE

    Bhorat, Haroon; Cassim, Aalia; Hirsch, Alan

    2014-01-01

    South Africa has exhibited tepid economic growth over the past twenty years as well as high levels of income inequality characteristic of a middle income country growth trap. This paper compares and contrasts South Africa's growth trap relative to middle-income peer economies. In addition, we study the policies and structures of the South African economy that have indeed perpetuated the persistently low levels of growth observed. In particular we consider the capital-intensive nature of manuf...

  4. Research on Dynamic Tension for Belt Conveyor with Constant Force Automatic Take-Up Assembly

    Institute of Scientific and Technical Information of China (English)

    MENG Guo-ying; CHEN Jing-li; LI Yu-jin

    2003-01-01

    The article Provides a dynamic model for belt conveyor. Based on the drive-force of conveyor, take-up tension of take-up assembly, gravity of conveyor belt and material, and friction between belt and idlers, it gives a viscoelastic dynamic equation for conveyor belt. It presents a calculation method of analytic solution to both viscoelastic dynamic equation and geometric dynamic equation when automatic take-up assembly is applied to belt conveyor. The article also makes a study of design method of limiting and eliminating the conveyor belt's elastic vibration.

  5. Aqueous alteration on main-belt asteroids

    Science.gov (United States)

    Fornasier, S.; Lantz, C.; Barucci, M.; Lazzarin, M.

    2014-07-01

    The study of aqueous alteration is particularly important for unraveling the processes occurring during the earliest times in Solar System history, as it can give information both on the thermal processes and on the localization of water sources in the asteroid belt, and for the associated astrobiological implications. The aqueous alteration process produces the low temperature (< 320 K) chemical alteration of materials by liquid water which acts as a solvent and produces materials like phyllosilicates, sulphates, oxides, carbonates, and hydroxides. This means that liquid water was present in the primordial asteroids, produced by the melting of water ice by heating sources, very probably by ^{26}Al decay. Hydrated minerals have been found mainly on Mars surface, on primitive main-belt asteroids (C, G, B, F, and P-type, following the classification scheme by Tholen, 1984) and possibly also on few transneptunian objects. Reflectance spectroscopy of aqueous altered asteroids shows absorption features in the 0.6-0.9 and 2.5-3.5-micron regions, which are diagnostic of, or associated with, hydrated minerals. In this work, we investigate the aqueous alteration process on a large sample of 600 visible spectra of C-complex asteroids available in the literature. We analyzed all these spectra in a similar way to characterize the absorption-band parameters (band center, depth, and width) and spectral slope, and to look for possible correlations between the aqueous alteration process and the asteroids taxonomic classes, orbital elements, heliocentric distances, albedo, and sizes. We find that 4.6 % of P, 7.7 % of F, 9.8 % of B, 50.5 % of C, and 100 % of the G-type asteroids have absorption bands in the visible region due to hydrated silicates. Our analysis shows that the aqueous alteration sequence starts from the P-type objects, practically unaltered, and increases through the P → F → B → C → G asteroids, these last being widely aqueously altered, strengthening thus

  6. A Call to African Unity

    DEFF Research Database (Denmark)

    Muchie, Mammo

    This month's paper, written by Professor Mammo Muchie, examines the necessity for a pan-African monetary union.  Professor Muchie argues for the "the creation of a unified African strategy and unified approach to dealing with the outside donor world by neutralising the poison of money as honey...... that donor aid has come to be in Africa." He provides a historic and contemporary context for the unification of monetary and customs systems across Africa and argues for a dual currency system for the self-financing of African development and for sustained self-determination....

  7. Middle East Respiratory Syndrome (MERS)

    Science.gov (United States)

    Middle East Respiratory Syndrome Coronavirus; MERS-CoV; Novel coronavirus; nCoV ... Centers for Disease Control and Prevention. Middle East ... 2, 2015. www.cdc.gov/coronavirus/mers/faq.html . Accessed April ...

  8. How student teachers understand African philosophy

    OpenAIRE

    Matsephe M. Letseka; Elza Venter

    2012-01-01

    The question ‘What constitutes African philosophy?’ was first raised with the publication of Placide Tempels’s seminal work Bantu philosophy in 1959. Tempels’s book inevitably elicited considerable critical response from African philosophers, which culminated in a wide range of publications such as Wiredu’s (1980) Philosophy and an African culture, Hountondji’s (1983) African philosophy: Myth and reality, Oruka’s (1990) Sage philosophy: Indigenous thinkers and modern debate on African philoso...

  9. Two new basaltic asteroids in the Outer Main Belt

    CERN Document Server

    Duffard, R

    2007-01-01

    The identification of other basaltic objects in the asteroid belt is mandatory to explain the diversity in the collection of basaltic meteorites. This diversity requires more than one differentiated parent body, a fact that is consistent with the diversity of differentiated parent bodies implied by the iron meteorites. Based on a list of previously identified candidate basaltic (V-type) asteroids, two asteroids in the outer main belt, (7472) Kumakiri and (10537) 1991 RY16, were spectroscopically observed during an observational run in Calar Alto Observatory, Spain. We confirm the V-type character of these two asteroids that, together with (1459) Magnya, become the only known traces of basaltic found in the outer main belt up to now. We also demonstrate that the searching for candidate V-type asteroids using a photometric survey, like the Sloan Digital Sky Survey, produces reliable results.

  10. Gravity inferred subsurface structure of Gadwal Schist belt, Andhra Pradesh

    Indian Academy of Sciences (India)

    G Ramadass; I B Ramaprasada Rao; N Srinivasulu

    2001-03-01

    Detailed gravity data collected across the Gadwal schist belt in the state of Andhra Pradesh show an 8.4 mgal residual gravity anomaly associated with meta-sediments/volcanics of the linear NNW-SSE trending schist belt that shows metamorphism from green schist to amphibolite facies. This schist belt is flanked on either side by the peninsular gneissic complex. The elevation and slab Bouguer corrected residual gravity profile data were interpreted using 2-D prism models. The results indicate a synformal structure having a width of 1.8 km at the surface, tapering at a depth of about 2.6 km with a positive density contrast of 0.15 gm/cc with respect to the surrounding peninsular gneissic complex.

  11. Regional Fault Systems of Qaidam Basin and Adjacent Orogenic Belts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The purpose of this paper is to analyze the regional fault systems of Qaidam basin and adjacent orogenic belts. Field investigation and seismic interpretation indicate that five regional fault systems occurred in the Qaidam and adjacent mountain belts, controlling the development and evolution of the Qaidam basin. These fault systems are: (1)north Qaidam-Qilian Mountain fault system; (2) south Qaidam-East Kunlun Mountain fault system; (3)Altun strike-slip fault system; (4)Elashan strike-slip fault system, and (5) Gansen-Xiaochaidan fault system. It is indicated that the fault systems controlled the orientation of the Qaidam basin, the formation and distribution of secondary faults within the basin,the migration of depocenters and the distribution of hydrocarbon accumulation belt.

  12. Relativistic surfatron process for Landau resonant electrons in radiation belts

    CERN Document Server

    Osmane, A

    2014-01-01

    Recent theoretical studies of the nonlinear wave-particle interactions for relativistic particles have shown that Landau resonant orbits could be efficiently accelerated along the mean background magnetic field for propagation angles $\\theta$ in close proximity to a critical propagation $\\theta_\\textrm{c}$ associated with a Hopf--Hopf bifurcation condition. In this report, we extend previous studies to reach greater modeling capacities for the study of electrons in radiation belts by including longitudinal wave effects and inhomogeneous magnetic fields. We find that even though both effects can limit the surfatron acceleration of electrons in radiation belts, gains in energy of the order of 100 keV, taking place on the order of ten milliseconds, are sufficiently strong for the mechanism to be relevant to radiation belt dynamics.

  13. TAKRAF belt conveyors - effective means of transport for bulk materials

    Energy Technology Data Exchange (ETDEWEB)

    Peterman, L.

    1988-11-01

    Presents belt conveyor types produced by TAKRAF, especially those intended for use at surface mines. The FAM works (Transport Equipment) produces belt conveyors 800-1,400 mm wide, with 2.09-5.24 m/s belt velocity, 460-3,750 m/sup 3//h capacity, max. feed distance 2,500 m and (1-5)x55 kW drive power. The drive stations are based on pontoons or caterpillar vehicles while the end-stations are based on pontoons. Charging hoppers have autonomic drives and are mobile on rail. The described conveyors can also be used in power plants. The FAM works produces 650-800 mm wide conveyors for thermal electric power stations. The conveyors are equipped with metal detectors and metal separators.

  14. Surfaces on African sculpture

    Directory of Open Access Journals (Sweden)

    John Mack

    2011-12-01

    Full Text Available Review of: Leonard Kahan, Donna Page, and Pascal James Imperato (eds in collaboration with Charles Bordogna and Bolaji Campbell with an introduction by Patrick McNaughton, Surfaces: Color, Substances, and Ritual Applications on African Sculpture, Indiana University Press, 2009.The book reviewed here has potential interest to a wide range of readers, whether researchers and academics, museum, curators, conservators or connoisseurs. It examines the perception of surface as an aspect of the indigenous understanding of sculpted objects in sub-Saharan Africa, treating of questions of materials, patination, colouration and use. It includes both survey essays and case studies (on the Bamana of Mali and the Yoriuba of Nigeria in a compendium which has suggestive implications beyond the immediate field of the Africanists to whom it is principally addressed.

  15. West African Antislavery Movements

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi; Pelckmans, Lotte

    2011-01-01

    to unite, mobilize and struggle. Members of anti-slavery movements with slave origins accessed power positions through peaceful electoral processes in Benin, mali, Niger and Mauritania. People of slave origins gained ground in local politics of a number of municipalities. In localities where anti-slavery......In the context of liberalization of West African political regimes, the upsurge of audacious political entrepreneurs who want to end chattel slavery in their nation-state, resulted in the legal criminalisation of slavery in both Mauritania (2007) and Niger (2003) and in a proposal to revise...... the penal code of Mali. Anti-slavery activists not only address their claims to their national governments but also intend to initiate change at local level. In that respect the democratic decentralization reforms were significant because they allowed educated anti-slavery activists to appeal their brethren...

  16. 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)

  17. The Belt voice: Acoustical measurements and esthetic correlates

    Science.gov (United States)

    Bounous, Barry Urban

    This dissertation explores the esthetic attributes of the Belt voice through spectral acoustical analysis. The process of understanding the nature and safe practice of Belt is just beginning, whereas the understanding of classical singing is well established. The unique nature of the Belt sound provides difficulties for voice teachers attempting to evaluate the quality and appropriateness of a particular sound or performance. This study attempts to provide answers to the question "does Belt conform to a set of measurable esthetic standards?" In answering this question, this paper expands on a previous study of the esthetic attributes of the classical baritone voice (see "Vocal Beauty", NATS Journal 51,1) which also drew some tentative conclusions about the Belt voice but which had an inadequate sample pool of subjects from which to draw. Further, this study demonstrates that it is possible to scientifically investigate the realm of musical esthetics in the singing voice. It is possible to go beyond the "a trained voice compared to an untrained voice" paradigm when evaluating quantitative vocal parameters and actually investigate what truly beautiful voices do. There are functions of sound energy (measured in dB) transference which may affect the nervous system in predictable ways and which can be measured and associated with esthetics. This study does not show consistency in measurements for absolute beauty (taste) even among belt teachers and researchers but does show some markers with varying degrees of importance which may point to a difference between our cognitive learned response to singing and our emotional, more visceral response to sounds. The markers which are significant in determining vocal beauty are: (1) Vibrancy-Characteristics of vibrato including speed, width, and consistency (low variability). (2) Spectral makeup-Ratio of partial strength above the fundamental to the fundamental. (3) Activity of the voice-The quantity of energy being produced. (4

  18. Mafic dykes at the southwestern margin of Eastern Ghats belt: Evidence of rifting and collision

    Indian Academy of Sciences (India)

    S Bhattacharya; A K Chaudhary; W Teixeira

    2010-12-01

    The southwestern margin of the Eastern Ghats Belt characteristically exposes ma fic dykes intruding massif-type charnockites. Dykes of olivine basalt of alkaline composition have characteristic trace element signatures comparable with Ocean Island Basalt (OIB). Most importantly strong positive Nb anomaly and low values of Zr/Nb ratio are consistent with OIB source of the mafic dykes. K –Ar isotopic data indicate two cooling ages at 740 and 530 Ma. The Pan-African thermal event could be related to reactivation of major shear zones and represented by leuco-granite vein along minor shear bands. And 740 Ma cooling age may indicate the low grade metamorphic imprints, noted in some of the dykes. Although no intrusion age could be determined from the present dataset, it could be constrained by some age data of the host charnockite gneiss and Alkaline rocks of the adjacent Prakasam Province. Assuming an intrusion age of ∼1 .3 Ga, Sr –Nd isotopic composition of the dykes indicate that they preserved time-integrated LREE enrichment. In view of the chemical signatures of OIB source, the ma fic dykes could as well be related to continental rifting, around 1.3 Ga, which may have been initiated by intra-plate volcanism.

  19. Evaluation of an Extended School Day Program for African American Males in the Context of Single Gender Schooling and Schoolwide Reform: A Case for Extending the School Day for African American Males

    Science.gov (United States)

    Fashola, Olatokunbo S.

    2013-01-01

    This article presents the results of the 2nd-year evaluation of an after-school program designed for an extended school day program serving African American middle school students in the city of Baltimore, Maryland (ACCESS-West). This study describes the effects of schoolwide reform especially as it relates to single-gender schools, educating…

  20. Traffic restrictions due to wind on the Fehmarn Belt bridge

    DEFF Research Database (Denmark)

    Dellwik, E.; Mann, Jakob; Rosenhagen, G.

    2006-01-01

    This report documents the calculations carried out in order to estimate the wind climate at the site where the Fehmarn Belt bridge is planned. Further, an estimate of how often and for how long traffic restrictions will be enforced according to statedcriteria (sec. 3.2) is given. This estimate...... are the same as used in this report and here the comparison is satisfactory. We estimate that the prospective Fehmarn Belt bridge will be closed roughly 2% of the timefor light roadway vehicles (unloaded trucks and caravans), corresponding to 7 days per year. This is slightly less than for the Fehmarnsund...

  1. Bifurcation for Dynamical Systems of Planet-Belt Interaction

    OpenAIRE

    Jiang, Ing-Guey; Yeh, Li-Chin

    2002-01-01

    The dynamical systems of planet-belt interaction are studied by the fixed-point analysis and the bifurcation of solutions on the parameter space is discussed. For most cases, our analytical and numerical results show that the locations of fixed points are determined by the parameters and these fixed points are either structurally stable or unstable. In addition to that, there are two special fixed points: the one on the inner edge of the belt is asymptotically stable and the one on the outer ...

  2. Middle Eastern solutions

    International Nuclear Information System (INIS)

    The need to consider the Middle East as a group of distinct countries and not as one single market and to tailor the services offered by companies is stressed. The cultures, political and social conditions, forms of the oil and gas industry in the countries making up the Middle East and their technology requirements are different and vary widely. The approach taken by Shell Global Solutions to these differences is described and illustrated with Shell's experiences in Oman and Saudi Arabia. Shell has found that Omanis are keen to work in their oil and gas industry, and to protect their country's natural environment. Saudi also have intense pride in their oil industry and here Shell supports refinery operators reduce costs while maintaining strict quality control. Shell has been selected to help Saudi Arabia develop its natural gas reserves; as part of the Core Venture 3 project, Shell will build a power desalination plant

  3. My Middle School Life

    Institute of Scientific and Technical Information of China (English)

    高懿; 吕静

    2004-01-01

    It is generally believed that the best time of one's hfe is their youth, and we spend most of it in our schools. So school is like a cradle which supports us from our childhood through adulthood. It also serves as a bridge between family and society. As a teenager, I have already studied more than 6 years in middle school, during which period I have gained notonly a great deal of knowledge but some valuable experience as well. The most important of all are the many unforgettable activities of school, which make my hfe more colorful.Looking back on my nearly 7 years' middle school hfe, I'd hke to divide it into two parts,that is, help and enjoyment.

  4. Mantle insulation beneath the West African craton during the Precambrian-Cambrian transition

    Science.gov (United States)

    Doblas, Miguel; López-Ruiz, José; Cebriá, José-María; Youbi, Nasrrddine; Degroote, Eugenio

    2002-09-01

    At the time of the Precambrian-Cambrian transition, the West African craton underwent widespread magmatism, hydrothermal activity, and thermal rejuvenation. This tectonothermal event gave rise to an anorogenic “ring of fire” along the rim of this craton, following the Pan-African Brasiliano belt that was reactivated by extension and transtension. The thermal phenomena were due to the progressive peripheral release of mantle heat that had built up beneath this craton because of strong insulating conditions. The West African craton at the Precambrian-Cambrian transition can thus be envisioned in terms of a gigantic pressure-cooker with a thick blanketing lithospheric lid. These insulation processes triggered an unusually hot mantle that was channeled by edge-driven convection toward the peri West African craton extensional corridors and released through magmatic pressure-relief valves. Massive ice melting and outgassing of volcanic CO2 gave rise to a planet-scale sea-level rise, a greenhouse effect, and the end of the icehouse snowball Earth. These processes played an important role in the Phanerozoic explosion of life on Earth.

  5. Possible influence of Arctic oscillation on precipitation along the East Asian rain belt during boreal spring

    Science.gov (United States)

    Qu, Jingxuan; Gong, Daoyi; Mao, Rui; Yang, Jing; Li, Sang

    2016-08-01

    In this study, the possible influence of the springtime Arctic oscillation (AO) on precipitation along the East Asian rain belt has been studied for the period of 1979 to 2014. To capture the features of the large-scale variability of the atmospheric circulation and precipitation, singular value decomposition (SVD) analysis was performed. The domain for precipitation is from 21.25 to 33.75° N and 111.25 to 133.25° E, and the 1000 hPa heights are from 20° N northward. Prior to analysis, the El Niño-Southern Oscillation (ENSO) signals were linearly fitted and subtracted from the variables of interest. The first paired modes explain 51.1 % of the total squared covariance. The spatial feature of the pressure mode is almost identical to that of the positive AO pattern, while the precipitation mode displays an overall less-than-normal anomaly along the rain belt. The AO indices are highly correlated with the time coefficients of the pressure mode at a value of 0.91, and for the time coefficients of the precipitation mode, the correlation is -0.44, both of which are significant at the 99 % level. The regional atmospheric circulation anomalies in association with the negative phase AO mode display consistent changes, including the anomalous southerly winds and vapor flux convergence in the lower troposphere over East Asia, the stronger East Asian westerly jet stream, and the enhanced ascending air motion between 20 and 30° N. There are two possible mechanisms linking the AO and East Asian circulation and precipitation, i.e., the wave-trains along the westerly jet stream from North Africa to the Middle East and East Asia and the dipole of an anti-cyclone and a cyclone over the North Pacific.

  6. Devonian to Triassic Successions of the Changning-Menglian Belt,Western Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    JIN Xiaochi; WANG Yizhao; XIE Guanglian

    2003-01-01

    Phanerozoic strata are distributed in several north-south trending zones in the central part of the Changning-Menglian Belt. Four types of Devonian to Triassic stratigraphic successions can be identified: (1) clastics with limestonelenses in the mid-section, changing up-section into alternations of fine clastics and cherts; (2) clastics with chertintercalations and limestone lenses, and topped by Permian basic volcanics; (3) clastics-basicvolcanics-carbonates-clastics; and (4) limestones, dolomitic limestones-dark gray thin-bedded limestones, argillaceouslimestones, mudstones and siliceous mudstones. Devonian to Triassic cherts occur in different horizons and differentzones from east to west. These cherts are usually transitional to their neighboring clastics. There is no continuousDevonian to Middle Triassic chert sequence in the central zone of the Changning-Menglian Belt as Liu et al. (1991, 1993)reported. Volcanics and the overlying carbonates described by some workers as "seamount" sequences are more likely tohave formed in a marine environment on continental crust. Succession (4) is newly recognized in the area from Menglai toYong'an in Cangyuan County and further north to Padi of Gengma County. Basalts, cherts and clastics also appear in thisarea. Mid-Triassic (very probably Ladinian) radiolarians extracted from bedded cherts in the Ganzhejidi section indicatethat they are in higher stratigraphic positions. The change from bedded cherts via siltstones to thick-bedded sandstoneswith thin-bedded fine intercalations in the Ganzhejidi section and (some other outcrops along the road from Cangyuan toGengma) suggests a fundamental change of sedimentary environment caused by a rapid increase of a large quantity ofdetritus supply. These siliciclastic sediments are possibly syn-orogenic deposits.

  7. African Ethnobotany in the Americas

    Directory of Open Access Journals (Sweden)

    Egleé L. Zent

    2013-10-01

    Full Text Available Review of African Ethnobotany in the Americas. Edited by Robert Voeks and John Rashford. 2013. Springer. Pp. 429, 105 illustrations, 69 color illustrations. $49.95 (paperback. ISBN 978‐1461408352.

  8. African Ethnobotany in the Americas

    OpenAIRE

    Zent, Egleé L

    2013-01-01

    Review of African Ethnobotany in the Americas. Edited by Robert Voeks and John Rashford. 2013. Springer. Pp. 429, 105 illustrations, 69 color illustrations. $49.95 (paperback). ISBN 978‐1461408352.

  9. Stuck in the Middle

    Institute of Scientific and Technical Information of China (English)

    YIN PUMIN

    2011-01-01

    Sun Lijun works as a software engineer at a Beijing-based IT company and earns around 8,000 yuan ($1254)a month.His relative y high income means his friends and colleagues,as well as China's statistical agencies,regard him as middle class.Sun,however,does not think he is worthy of being included in a category that is traditionally associated with security and comfort.

  10. Educating At-Risk Urban African American Children: The Effects of School Climate on Motivation and Academic Achievement

    Science.gov (United States)

    Fenzel, L. Mickey; O'Brennan, Lindsey M.

    2007-01-01

    The present study examines the mediating effects of student intrinsic motivation and teacher ratings of student academic engagement on the relation between school climate perceptions and student academic performance among 282 urban African American middle school students. Results provided support for the hypothesized model and suggest the…

  11. Sociocultural Factors and School Engagement among African American Youth: The Roles of Racial Discrimination, Racial Socialization, and Ethnic Identity

    Science.gov (United States)

    Dotterer, Aryn M.; McHale, Susan M.; Crouter, Ann C.

    2009-01-01

    This study investigated the links between racial discrimination and school engagement and the roles of racial socialization and ethnic identity as protective factors in those linkages in a sample of 148, sixth through twelfth grade African American adolescents from working and middle-class two-parent families. In home interviews, youth described…

  12. Racism, Parent Support, and Math-Based Career Interests, Efficacy, and Outcome Expectations among African American Adolescents

    Science.gov (United States)

    Alliman-Brissett, Annette E.; Turner, Sherri L.

    2010-01-01

    Using an extended model of social cognitive career theory, this study investigated ways in which African American middle school adolescents perceive racism and the associations among various aspects of perceptions of racism, other background factors, and math-based career interests, efficacy, and outcome expectations. Results indicated that…

  13. The Good African Society Index

    OpenAIRE

    Ferdi Botha

    2014-01-01

    This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (i) economic sustainability, (ii) democracy and freedom, (iii) child well-being, (iv) environment and infrastructure, (v) safety and security, (vi) health and health systems, (vii) integrity and justice, (viii) education, and (xi) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 i...

  14. Twin Sessions Through African Eyes

    Institute of Scientific and Technical Information of China (English)

    Ni Yanshuo

    2012-01-01

    Every year journalists from around China and the world flock to Beijing in March to cover the sessions of the National People's Congress (NPC) and the Chinese People's Political Consultative Conference (CPPCC), known as the lianghui, or twin sessions. With the deepening of Sino-African relations in the past decades, an increasing number of African journalists are involved in reporting China's lianghui to their audiences in Africa.

  15. Training in African aquaculture development

    OpenAIRE

    Brummett, R. E.

    1994-01-01

    The article focuses on the types of training needed in African aquaculture development. The author suggested that rather than needing less training, extension agents and others who operate in the idiosyncratic world of the poor African farmer, need a far deeper understanding of fish culture (particularly the basics of pond dynamics and ecology) than do those who can take advantage of industrialized-country infrastructure.

  16. Zār Spirit Possession in Iran and African Countries: Group Distress, Culture-Bound Syndrome or Cultural Concept of Distress?

    Directory of Open Access Journals (Sweden)

    Fahimeh Mianji

    2015-12-01

    Full Text Available Zār is the term used to describe a form of spirit possession common in northern African, eastern African, and some Middle-Eastern societies. Although these regions share some cultural similarities arising from their history of slavery, in these places, zār varies in prevalence, clinical characteristics, and social context. Based on a selective review of the literature, this paper looks at the place of zār spirit possession in both DSM-IV and DSM-V; it also examines how zār is manifested in Iran and in African countries including Sudan, Ethiopia, and Egypt; and it aims to provide practical information to mental health clinicians so that they can better understand how this cultural concept is practiced by Iranians and Middle Eastern and African immigrants living near the Persian Gulf coast.

  17. Eclogite-High-Pressure Granulite Belt in Northern Edge of the Archean North China Craton

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The discovery of retrograded eclogites and high-pressure basic granulites in the joining region of Hebei-Shanxi-Inner Mongolia (HSIM) abandon the old thoughts that Archean granulites in the North China craton are of middle or low pressure facies and promote the reconsideration of Early Precambrian cratonization tectonic process, and reveal the geological fact that the scale, rigid behavior and geological structure of Archean cratonic blocks have strong similarities to the present fundamental plate tectonics, which suggest new tectonic mechanism to understand the early continental evolution of the North China craton. (1) The retrograded eclogites and high-pressure granulites constitute a ENE-NE-striking structure-rock zone termed as the Sanggan structural belt. (2) The retrograded eclogites are closely associated with high-pressure granulites. We can call this belt a transitional eclogite-granulite facies metamorphic belt. Petrographically three metamorphic stages, at least, in the retrograded eclogite can be distinguished. ① The main mineral assemblage is composed of garnet+clinopyroxene+quartz+rutile. The mineral inclusions in garnet are fine-grained quartz, rutile and small inclusions of fine-grained second stage mineral aggregate. This aggregate consists of hypersthene+albite, and has the typical texture of small hypersthene core surrounded by albite micro-grained grains. ② The second mineral assemblage is represented by corona of garnet and symplectite of clinopyroxene. The corona of garnet is composed of hypersthene+plagioclase+clinopyroxene+a minor amount of quartz and magnetite. The symplectite of clinopyroxene is composed of hypersthene + albite+clinopyroxene. The secondary mineral assemblage along boundaries between quartz and garnet (or clinopyroxene) is fine-grained aggregate of hypersthene and clinopyroxene. ③ The third retrograded metamorphic minerals are mainly amphiboles replacing pyroxenes and plagioclases replacing garnets. The estimated

  18. Modelling middle pliocene warm climates of the USA

    Science.gov (United States)

    Haywood, A.M.; Valdes, P.J.; Sellwood, B.W.; Kaplan, J.O.; Dowsett, H.J.

    2001-01-01

    The middle Pliocene warm period represents a unique time slice in which to model and understand climatic processes operating under a warm climatic regime. Palaeoclimatic model simulations, focussed on the United States of America (USA), for the middle Pliocene (ca 3 Ma) were generated using the USGS PRISM2 2?? ?? 2?? data set of boundary conditions and the UK Meteorological Office's HadAMS General Circulation Model (GCM). Model results suggest that conditions in the USA during the middle Pliocene can be characterised as annually warmer (by 2?? to 4??C), less seasonal, wetter (by a maximum of 4 to 8 mm/day) and with an absence of freezing winters over the central and southern Great Plains. A sensitivity experiment suggests that the main forcing mechanisms for surface temperature changes in near coastal areas are the imposed Pliocene sea surface temperatures (SST's). In interior regions, reduced Northern Hemisphere terrestrial ice, combined with less snow cover and a reduction in the elevation of the western cordillera of North America, generate atmospheric circulation changes and positive albedo feedbacks that raise surface temperatures. A complex set of climatic feedback mechanisms cause an enhancement of the hydrological cycle magnifying the moisture bearing westerly wind belt during the winter season (Dec., Jan., Feb.). Predictions produced by the model are in broad agreement with available geological evidence. However, the GCM appears to underestimate precipitation levels in the interior and central regions of the southern USA. Copyright: Palaeontological Association, 22 June 2001.

  19. Influences of Relative Sea-Level Rise and Mississippi River Delta Plain Evolution on the Holocene Middle Amite River, Southeastern Louisiana

    Science.gov (United States)

    Autin, Whitney J.

    1993-01-01

    The Holocene geomorphic history of southeastern Louisiana's middle Amite River is recorded in the stratigraphy of three alloformations, identified in decreasing age as the Watson (WAT), Denham Springs (DS), and Magnolia Bridge (MAG). The WAT meander belt formed by at least 9000 yr B.P., when sea level was lower and the Amite River was tributary to a larger ancestral drainage basin. The DS became an active meander belt by at least 3000 yr B.P., in response to relative sea-level rise and eastward progradation of the Mississippi River delta plain. The MAG developed its meander belt, in part, during the European settlement of the drainage basin, and is now attempting to adjust to modern anthropogenic influences. Geomorphic influences on the middle Amite River floodplain have temporal and spatial components that induce regional- and local-scale effects. Regional extrinsic influences caused meander belt avulsion that produced alloformations. However, local influences produced intrinsic geomorphic thresholds that modified channel morphology within a meander belt but did not induce alloformation development. Base-level influences of the relative sea-level rise and the Mississippi River delta plain were so dominant that the effects of possible climate change were not recognized in the Holocene Amite River system.

  20. Aggression, academic behaviors, and popularity perceptions among boys of color during the transition to middle school.

    Science.gov (United States)

    Xie, Hongling; Dawes, Molly; Wurster, Tabitha J; Shi, Bing

    2013-01-01

    The transition to middle school often presents behavioral and academic challenges to youths. Boys of color (i.e., African American and Hispanic in this study) may be especially vulnerable. In this study, peer nominations of aggressive and academic behaviors as well as youths' perceptions of how these behaviors were related to popularity in peer networks were obtained from the spring semester of fifth grade through the spring semester of seventh grade, with the transition occurring as the students entered the sixth grade. The sample included 188 boys (71 Caucasian, 90 African American, and 27 Hispanic) from an urban school district in the northeastern United States. Trajectory analyses showed that African American boys scored lower in studentship and higher in rule-breaking and aggressive (both physical and social) behaviors prior to the transition, and such differences among ethnic groups were largely maintained during the transition. Hispanic boys displayed decreases in their studentship during the transition. African American boys' perception of how studentship affects popularity was more positive than other boys prior to the transition, but it decreased during the transition. African American boys also endorsed rule breaking and physical and social aggression more positively for popularity prior to the transition, whereas Caucasian and Hispanic boys' endorsement increased during the transition and eventually caught up with those of African American boys in seventh grade. A positive within-individual association was found between youths' popularity perception and their behavior for studentship, rule breaking, and physical aggression, which did not differ by ethnicity.

  1. Design study of flat belt CVT for electric vehicles

    Science.gov (United States)

    Kumm, E. L.

    1980-01-01

    A continuously variable transmission (CVT) was studied, using a novel flat belt pulley arrangement which couples the high speed output shaft of an energy storage flywheel to the drive train of an electric vehicle. A specific CVT arrangement was recommended and its components were selected and sized, based on the design requirements of a 1700 KG vehicle. A design layout was prepared and engineering calculations made of component efficiencies and operating life. The transmission efficiency was calculated to be significantly over 90% with the expected vehicle operation. A design consistent with automotive practice for low future production costs was considered, together with maintainability. The technology advancements required to develop the flat belt CVT were identified and an estimate was made of how the size of the flat belt CVT scales to larger and smaller design output torques. The suitability of the flat belt CVT for alternate application to an electric vehicle powered by an electric motor without flywheel and to a hybrid electric vehicle powered by an electric motor with an internal combustion engine was studied.

  2. Resolving the Planetesimal Belt of HR 8799 with ALMA

    CERN Document Server

    Booth, Mark; Casassus, Simon; Hales, Antonio S; Dent, William R F; Faramaz, Virginie; Matrà, Luca; Barkats, Denis; Brahm, Rafael; Cuadra, Jorge

    2016-01-01

    The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fit by a broad ring between $145^{+12}_{-12}$ AU and $429^{+37}_{-32}$ AU at an inclination of $40^{+5}_{-6}${\\deg} and a position angle of $51^{+8}_{-8}${\\deg}. A disc edge at ~145 AU is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orb...

  3. Nature of the Kirkwood gaps in the asteroid belt

    Energy Technology Data Exchange (ETDEWEB)

    Dermott, S.F.; Murray, C.D. (Cornell Univ., Ithaca, NY (USA). Lab. for Planetary Studies)

    1983-01-20

    The distributions of orbital eccentricities and inclinations near the Jovian resonances in the asteroid belt show that the observed Kirkwood gaps in the distribution of the semimajor axes were formed after the asteroids had dispersed from the near-coplanar disk in which they accreted.

  4. Uranium deposits of the Grants, New Mexico mineral belt (II)

    International Nuclear Information System (INIS)

    This is part of a study of the genesis of the U deposits of the Grants mineral belt. Enrichment of Mg in ore zones is frequently observed, with chlorite being a common product. Clay mineralogic studies argue for chlorite-illite-montmorillonite associations with ores. The methods include scanning electron microscopy, Eh-pH diagrams, activation analysis, and rare earth element studies

  5. Resolving the planetesimal belt of HR 8799 with ALMA

    Science.gov (United States)

    Booth, Mark; Jordán, Andrés; Casassus, Simon; Hales, Antonio S.; Dent, William R. F.; Faramaz, Virginie; Matrà, Luca; Barkats, Denis; Brahm, Rafael; Cuadra, Jorge

    2016-07-01

    The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fitted by a broad ring between 145^{+12}_{-12} au and 429^{+37}_{-32} au at an inclination of 40^{+5}_{-6}° and a position angle of 51^{+8}_{-8}°. A disc edge at ˜145 au is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orbit of planet b.

  6. Collisional and dynamic evolution of dust from the asteroid belt

    Science.gov (United States)

    Gustafson, Bo A. S.; Gruen, Eberhard; Dermott, Stanley F.; Durda, Daniel D.

    1992-01-01

    The size and spatial distribution of collisional debris from main belt asteroids is modeled over a 10 million year period. The model dust and meteoroid particles spiral toward the Sun under the action of Poynting-Robertson drag and grind down as they collide with a static background of field particles.

  7. Influence of the Gould Belt on Interstellar Extinction

    CERN Document Server

    Gontcharov, George

    2016-01-01

    A new analytical 3D model of interstellar extinction within 500 pc of the Sun as a function of the Galactic spherical coordinates is suggested. This model is physically more justified than the widely used Arenou model, since it takes into account the presence of absorbing matter both in the layer along the equatorial Galactic plane and in the Gould Belt. The extinction in the equatorial layer varies as the sine of the Galactic longitude and in the Gould Belt as the sine of twice the longitude in the Belt plane. The extinction across the layers varies according to a barometric law. It has been found that the absorbing layers intersect at an angle of 17 deg and that the Sun is located near the axial plane of the absorbing layer of the Gould Belt and is probably several parsecs below the axial plane of the equatorial absorbing layer but above the Galactic plane. The model has been tested using the extinction of real stars from three catalogs.

  8. Structural appraisal of the Gadag schist belt from gravity investigations

    Indian Academy of Sciences (India)

    G Ramadass; D Himabindu; N Srinivasulu

    2003-12-01

    Semi-detailed gravity investigations were carried out over an area of approximately 2750 sq km with maximum N-S and E-W extents of 55 and 50km respectively in the Gadag region in the Dharwar craton with a view to obtain a clearer perception of the structural configuration of the region. From qualitative analysis of the gravity data, several tectonic features are inferred: the high density Gadag schist belt is characterized by a gravity high and occurs in two discontinuous segments — the main N-S trending segment, and its thinner NW-SE trending extension, the two separated by a NE-SW trending deep seated fault. While the N-S trend of the Gadag schist belt is bounded on its east by the NW-SE trending Chitradurga thrust fault and on its west by another major NNW-SSE trending fault, the NW-SE extension is likewise bounded by two other NW-SE major faults. Quantitative evaluation from forward modeling/inversion of five profiles in the region, assuming a density contrast of 0.29 gm/cc of the anomalous schistose body with the gneissic host rocks indicated a synclinal structure plunging to the southeast along its axis for the Gadag schist belt. The maximum width and depth from surface of the schist belt are 22km and 5.6km respectively.

  9. 1991 National campaign to increase safety belt usage.

    NARCIS (Netherlands)

    National Highway Traffic Safety Administration NHTSA

    1992-01-01

    The central theme of this paper is the national campaign of the USA to be conducted in 1991 and 1992, in order to reach the goal of 70 percent safety belt usage by 1992. Among other things, it is shown that visible enforcement of existing laws offers the greatest potential for achieving this goal. F

  10. WISE Albedos for Tens of Thousands of Main Belt Asteroids

    NARCIS (Netherlands)

    Masiero, Joseph R.; Mainzer, A. K.; Bauer, J.; Cutri, R.; Dailey, J.; Delbo, M.; Grav, T.; McMillan, R. S.; Mueller, M.; Walker, R.; Wright, E.; WISE Science Team, [No Value

    2010-01-01

    Using thermal IR data from the Wide-field Infrared Survey Explorer (WISE) mission we have calculated diameters for tens of thousands of previously known Main Belt asteroids. Using archival optical observations we have also determined albedos for each object. We present our results from this investig

  11. Shaping mobile belts by small-scale convection.

    Science.gov (United States)

    Faccenna, Claudio; Becker, Thorsten W

    2010-06-01

    Mobile belts are long-lived deformation zones composed of an ensemble of crustal fragments, distributed over hundreds of kilometres inside continental convergent margins. The Mediterranean represents a remarkable example of this tectonic setting: the region hosts a diffuse boundary between the Nubia and Eurasia plates comprised of a mosaic of microplates that move and deform independently from the overall plate convergence. Surface expressions of Mediterranean tectonics include deep, subsiding backarc basins, intraplate plateaux and uplifting orogenic belts. Although the kinematics of the area are now fairly well defined, the dynamical origins of many of these active features are controversial and usually attributed to crustal and lithospheric interactions. However, the effects of mantle convection, well established for continental interiors, should be particularly relevant in a mobile belt, and modelling may constrain important parameters such as slab coherence and lithospheric strength. Here we compute global mantle flow on the basis of recent, high-resolution seismic tomography to investigate the role of buoyancy-driven and plate-motion-induced mantle circulation for the Mediterranean. We show that mantle flow provides an explanation for much of the observed dynamic topography and microplate motion in the region. More generally, vigorous small-scale convection in the uppermost mantle may also underpin other complex mobile belts such as the North American Cordillera or the Himalayan-Tibetan collision zone. PMID:20520711

  12. A reappraisal of polymetamorphism in the Eastern Ghats belt - A view from north of the Godavari rift

    Indian Academy of Sciences (India)

    A Bhattacharya; S Gupta

    2001-12-01

    Evidence collated from different parts of the Eastern Ghats belt north of the Godavari rift (barring the ``Western Charnockite Zone") indicates that this sector evolved through a series of compressive structures (1 to 3), with prolific migmatization in quartzofeldspathic and metapelitic gneisses synchronous with 1 shortening, as was the syn- 1 emplacement of profuse megacrystic K-feldspar-bearing granitoid bodies. Thereafter, melt productivity of the rocks (synchronous with 2 - 3 folding) sharply decreased. Mineral parageneses stable in the 1, 2 and 3 fabrics indicate persistence of granulite facies conditions. P-T estimates on orthopyroxene + garnet + plagioclase + quartz assemblages anchored to recrystallized mosaic that overgrow all penetrative fabric elements in mafic granulites, granitoids and quartzofeldspathic gneisses are in the range of 900°-950°C and P ≅ 8-9 kbar. This estimate is comparable to those retrieved from sapphirine-bearing paragenesis in Mg-Al metapelites that appear to be diachronous in relation to the fabric elements, and arguably disrupt the granoblastic mosaic. These facets in the northern sector of the orogenic belt are compatible with either a single cycle of tectonic events (i.e., 1, 2 and 3 in continuum), or temporally-separate thermo-tectonic events, with the peak of earlier metamorphism (pre- to syn-1) at lower temperature (in the granulite facies) in comparison to the record of high post-3-max values. It is suggested on the basis of the above evidence that the late Proterozoic/Pan-African granulites in the Eastern Ghats belt north of the Godavari rift, are unlikely to be reworked equivalents of any older granulitic crust, such as the ∼1.6 Ga granulites south of the rift. Instead, the temporally disparate sectors may represent different crustal segments with unconnected pre-amalgamation tectonic history. However, if the ∼1.6 Ga granulites of the Western Charnockite Zone continue northwards across the rift, as suggested by

  13. PROPOSALS ON IMPROVING THE EXCAVATION, TRANSPORT AND COAL DEPOSIT, USING THE RUBBER CONVEYOR BELT

    Directory of Open Access Journals (Sweden)

    Nicoleta-Maria MIHUT

    2016-05-01

    Full Text Available In this work we make a study of the improvement methods of quantity of material transported by conveyor belt. Determination of discharge of solids entail establish of the parameters of the conveyor belt. As a result, we determine the belt speed who provide maximum discharge of solids materials.

  14. The New African Civil-Military Relations

    DEFF Research Database (Denmark)

    on the African continent to embark upon the New African Civil Military Relations (ACMR). In the last decade and half, the implosion of African states exposed to forces of democratization has escalated, manifest in Algeria, Egypt, Mali, Madagascar, Somalia, South Sudan, Central African Republic and Lesotho...... accorded the responsibility of organizing a Session on ACMR. From amongst some of the exciting Abstracts presented, authors submitted these as full chapters for this book which captures International African Studies Perspectives, managed by the African Public Policy & Research Institute (APPRI...

  15. Paired Magmatic-Metallogenic Belts in Myanmar - an Andean Analogue?

    Science.gov (United States)

    Gardiner, Nicholas; Robb, Laurence; Searle, Michael; Morley, Christopher

    2015-04-01

    Myanmar (Burma) is richly endowed in precious and base metals, having one of the most diverse collections of natural resources in SE Asia. Its geological history is dominated by the staged closing of Tethys and the suturing of Gondwana-derived continental fragments onto the South China craton during the Mesozoic-Cenozoic. The country is located at a crucial geologic juncture where the main convergent Tethyan collision zone swings south around the Namche Barwa Eastern Himalayan syntaxis. However, despite recent work, the geological and geodynamic history of Myanmar remains enigmatic. Plate margin processes, magmatism, metasomatism and the genesis of mineral deposits are intricately linked, and there has long been recognized a relationship between the distribution of certain mineral deposit types, and the tectonic settings which favour their genesis. A better knowledge of the regional tectonic evolution of a potential exploration jurisdiction is therefore crucial to understanding its minerals prospectivity. This strong association between tectonics and mineralization can equally be applied in reverse. By mapping out the spatial, and temporal, distribution of presumed co-genetic mineral deposits, coupled with an understanding of their collective metallogenetic origin, a better appreciation of the tectonic evolution of a terrane may be elucidated. Identification and categorization of metallotects within a geodynamically-evolving terrane thus provides a complimentary tool to other methodologies (e.g. geochemical, geochronological, structural, geophysical, stratigraphical), for determining the tectonic history and inferred geodynamic setting of that terrane through time. Myanmar is one such study area where this approach can be undertaken. Here are found two near-parallel magmatic belts, which together contain a significant proportion of that country's mineral wealth of tin, tungsten, copper, gold and silver. Although only a few 100 km's apart, these belts exhibit a

  16. Belt(s) of debris resolved around the Sco-Cen star HIP 67497

    CERN Document Server

    Bonnefoy, M; Ménard, F; Vigan, A; Lagrange, A -M; Delorme, P; Boccaletti, A; Lazzoni, C; Galicher, R; Desidera, S; Chauvin, G; Augereau, J C; Mouillet, D; Pinte, C; van der Plas, G; Gratton, R; Beust, H; Beuzit, J L

    2016-01-01

    In 2015, we initiated a survey of Scorpius-Centaurus A-F stars that are predicted to host warm-inner and cold-outer belts of debris similar to the case of the system HR~8799. The survey aims to resolve the disks and detect planets responsible for the disk morphology. In this paper, we study the F-type star HIP~67497 and present a first-order modelisation of the disk in order to derive its main properties. We used the near-infrared integral field spectrograph (IFS) and dual-band imager IRDIS of VLT/SPHERE to obtain angular-differential imaging observations of the circumstellar environnement of HIP~67497. We removed the stellar halo with PCA and TLOCI algorithms. We modeled the disk emission with the GRaTeR code. We resolve a ring-like structure that extends up to $\\sim$450 mas ($\\sim$50 au) from the star in the IRDIS and IFS data. It is best reproduced by models of a non-eccentric ring with an inclination of $80\\pm1^{\\circ}$, a position angle of $-93\\pm1^{\\circ}$, and a semi-major axis of $59\\pm3$ au. We also ...

  17. East African Rift

    Science.gov (United States)

    2008-01-01

    Places where the earth's crust has formed deep fissures and the plates have begun to move apart develop rift structures in which elongate blocks have subsided relative to the blocks on either side. The East African Rift is a world-famous example of such rifting. It is characterized by 1) topographic deep valleys in the rift zone, 2) sheer escarpments along the faulted walls of the rift zone, 3) a chain of lakes within the rift, most of the lakes highly saline due to evaporation in the hot temperatures characteristic of climates near the equator, 4) voluminous amounts of volcanic rocks that have flowed from faults along the sides of the rift, and 5) volcanic cones where magma flow was most intense. This example in Kenya displays most of these features near Lake Begoria. The image was acquired December 18, 2002, covers an area of 40.5 x 32 km, and is located at 0.1 degrees north latitude, 36.1 degrees east longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  18. Disarmament: the African perspective

    International Nuclear Information System (INIS)

    Disarmament is now generally accepted as the process of reduction in the size of, and expenditures on, armed forces, the destruction or dismantling of weapons, whether deployed or stockpiled, the progressive elimination of the capacity to produce new weapons and the release and integration into civilian life of military personnel. To realize this objective, the nations of the world have been advocating such measures as the establishment of nuclear weapon-free zones, non-proliferation, limitation of the arms trade, reduction of military budgets, and confidence-building measures. To ensure general and complete elimination of arms, there has been widespread recognition of the need to link the disarmament process with other political as well as socio-economic problems of the world such as the need for security, good relations between states and development of a system of peaceful settlement of disputes. Other measures that have been considered to be relevant in boosting the disarmament process include the role of the general public in putting pressure on their respective governments with a view to accelerating and realizing disarmament objectives. Africans have presented to the world a strong case for global disarmament

  19. Young Adult South African Daughters’ Perceptions of Paternal Involvement and Nurturance

    Directory of Open Access Journals (Sweden)

    Sonja Wessels

    2014-12-01

    Full Text Available This study aimed to assess current and retrospective levels of reported and desired paternal involvement experienced by young adult daughters, as well as current and retrospective levels of paternal nurturance. A sample of 89, female, third year South African Psychology students completed self-administered questionnaires, consisting of a biographical questionnaire, four Father Involvement Scales and two Nurturant Father Scales. Daughters reported their fathers as having been involved and nurturing while growing up. Although they indicated that they perceived fathers as somewhat less involved in young adulthood; they reported being satisfied with the level of father involvement. Daughters also reported high current paternal nurturance. The findings therefore indicate that a group of middle to upper middle-class South African daughters perceived their fathers as relatively involved in their lives and suggest that their fathers’ involvement extends beyond traditional father roles.

  20. TECTONICS OF THE DABIE OROGENIC BELT, CENTRAL CHINA

    Institute of Scientific and Technical Information of China (English)

    GUO Fu-sheng; XIA Fei; PENG Hua-ming; DU Yang-song

    2002-01-01

    Tectonically the Dabie orogenic belt consists mainly of the Dabieshan Yanshanian uplifted zone and the Beihuaiyang Variscan-Indosinian folding zone. In the north boundary adjoining the North China Block, there are an Early Palaeozoic ophiolitic mixtite belt and the Hefei Mesozoic-Cenozoic faulted basin which overlaps on the suture belt. In the south of Dabie orogen, there is a secondary tectonic unit called Foreland thrust-faulted structural zone which was mainly formed by the intracontinental subductions during Mesozoic era. The study shows that the Dabie Block is a part of mid-late Proterozoic palaeo-island arc at the north margin of Yangtze Block. During Caledonian period, as a submerged uplift at the northen continental margin of Yangtze Block, the Dabie Block collided with the early Palaeozoic palaeo-island arc at the south margin of North China Block, resulting in the convergence of the North and South China Blocks and the disappearance of oceanic crust. Since then,large-scale intracontinental subductions were followed. Dabie Orogenic Belt is the product of overlapping of Yangtze Block, Dabie Block and North China Block under the mechanism of intracontinental subduction. Indosinian period is the period of chief deformation and high pressure dynamic metamorphism for Dabie Block, and Yanshan period is the main orogenic period in which the remelting of crust caused by basement shearing resulted in large scale thermometamorphism. The present tectonic framework of the orogen was finally formed by the rapid uplifting of the Dabieshan mountains and gliding southwards, which result in the developing of thrust belt on south side and the extensional tectonic movement on north side.

  1. Flexible electrode belt for EIT using nanofiber web dry electrodes

    International Nuclear Information System (INIS)

    Efficient connection of multiple electrodes to the body for impedance measurement and voltage monitoring applications is of critical importance to measurement quality and practicality. Electrical impedance tomography (EIT) experiments have generally required a cumbersome procedure to attach the multiple electrodes needed in EIT. Once placed, these electrodes must then maintain good contact with the skin during measurements that may last several hours. There is usually also the need to manage the wires that run between the electrodes and the EIT system. These problems become more severe as the number of electrodes increases, and may limit the practicality and portability of this imaging method. There have been several trials describing human–electrode interfaces using configurations such as electrode belts, helmets or rings. In this paper, we describe an electrode belt we developed for long-term EIT monitoring of human lung ventilation. The belt included 16 embossed electrodes that were designed to make good contact with the skin. The electrodes were fabricated using an Ag-plated PVDF nanofiber web and metallic threads. A large contact area and padding were used behind each electrode to improve subject comfort and reduce contact impedances. The electrodes were incorporated, equally spaced, into an elasticated fabric belt. We tested the electrode belt in conjunction with the KHU Mark1 multi-frequency EIT system, and demonstrate time-difference images of phantoms and human subjects during normal breathing and running. We found that the Ag-plated PVDF nanofiber web electrodes were suitable for long-term measurement because of their flexibility and durability. Moreover, the contact impedance and stability of the Ag-plated PVDF nanofiber web electrodes were found to be comparable to similarly tested Ag/AgCl electrodes. (paper)

  2. An African ethic for nursing?

    Science.gov (United States)

    Haegert, S

    2000-11-01

    This article derives from a doctoral thesis in which a particular discourse was used as a 'paradigm case'. From this discourse an ethic set within a South African culture arose. Using many cultural 'voices' to aid the understanding of this narrative, the ethic shows that one can build on both a 'justice' and a 'care' ethic. With further development based on African culture one can take the ethic of care deeper and reveal 'layers of understanding'. Care, together with compassion, forms the foundation of morality. Nursing ethics has followed particular western moral philosophers. Often nursing ethics has been taught along the lines of Kohlberg's theory of morality, with its emphasis on rules, rights, duties and general obligations. These principles were universalistic, masculine and noncontextual. However, there is a new ethical movement among Thomist philosophers along the lines to be expounded in this article. Nurses such as Benner, Bevis, Dunlop, Fry and Gadow--to name but a few--have welcomed the concept of an 'ethic of care'. Gilligan's work gave a feminist view and situated ethics in the everyday aspects of responsiveness, responsibility, context and concern. Shutte's search for a 'philosophy for Africa' has resulted in finding similarities in Setiloane and in Senghor with those of Thomist philosophers. Using this African philosophy and a research participant's narrative, an African ethic evolves out of the African proverb: 'A person is a person through other persons', or its alternative rendering: 'I am because we are: we are because I am.' This hermeneutic narrative reveals 'the way affect imbues activity with ethical meaning' within the context of a black nursing sister in a rural South African hospital. It expands upon the above proverb and incorporates the South African constitutional idea of 'Ubuntu' (compassion and justice or humanness).

  3. Designing as middle ground

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt; Binder, Thomas

    2010-01-01

    The theoretical background in this chapter is science and technology studies and actor network theory, enabling investigation of heterogeneity, agency and perfor-mative effects through ‘symmetric’ analysis. The concept of design is defined as being imaginative and mindful to a number of actors...... research is an articulation of design activity taking place as a middle ground and as an intermixture between a ‘scientific’ regime of knowledge transfer and a capital ‘D’ ‘Designerly’ regime of authoring....

  4. MIDDLE CLASS MOVEMENTS

    OpenAIRE

    Dr. K. Sravana Kumar

    2016-01-01

                The middle class is placed between labour and capital. It neither directly awns the means of production that pumps out the surplus generated by wage labour power, nor does it, by its own labour, produce the surplus which has use and exchange value. Broadly speaking, this class consists of the petty bourgeoisie and the white-collar workers. The former are either self-employed or involved in the distribution of commodities and t...

  5. Structural and geochemical mapping of a Fe-mineralized quartz-mica rich unit in the Ringvassøya Greenstone Belt, West Troms Basement Complex

    OpenAIRE

    Elvenes, Hallgeir

    2015-01-01

    Ringvassøy is one of a chain of large coastal islands representing the Archaean to Paleoproterozoic West Troms Basement Complex (WTBC), west of the Caledonides. On Ringvassøy, a basement of mainly tonalitic gneiss is overlain by the Ringvassøy Greenstone Belt (RGB), which is metamorphosed up to middle amphibolite facies. Tonalitic gneiss in the west and southeast of the island has U–Pb zircon ages of 2.84–2.82 Ga, similar to U–Pb zircon ages of 2.85–2.83 Ga for metavolcanics in the RGB. Mafic...

  6. Revisions to the original extent of the Devonian Shale-Middle and Upper Paleozoic Total Petroleum System

    Science.gov (United States)

    Enomoto, Catherine B.; Rouse, William A.; Trippi, Michael H.; Higley, Debra K.

    2016-04-11

    Technically recoverable undiscovered hydrocarbon resources in continuous accumulations are present in Upper Devonian and Lower Mississippian strata in the Appalachian Basin Petroleum Province. The province includes parts of New York, Pennsylvania, Ohio, Maryland, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. The Upper Devonian and Lower Mississippian strata are part of the previously defined Devonian Shale-Middle and Upper Paleozoic Total Petroleum System (TPS) that extends from New York to Tennessee. This publication presents a revision to the extent of the Devonian Shale-Middle and Upper Paleozoic TPS. The most significant modification to the maximum extent of the Devonian Shale-Middle and Upper Paleozoic TPS is to the south and southwest, adding areas in Tennessee, Georgia, Alabama, and Mississippi where Devonian strata, including potential petroleum source rocks, are present in the subsurface up to the outcrop. The Middle to Upper Devonian Chattanooga Shale extends from southeastern Kentucky to Alabama and eastern Mississippi. Production from Devonian shale has been established in the Appalachian fold and thrust belt of northeastern Alabama. Exploratory drilling has encountered Middle to Upper Devonian strata containing organic-rich shale in west-central Alabama. The areas added to the TPS are located in the Valley and Ridge, Interior Low Plateaus, and Appalachian Plateaus physiographic provinces, including the portion of the Appalachian fold and thrust belt buried beneath Cretaceous and younger sediments that were deposited on the U.S. Gulf Coastal Plain.

  7. ASSESSMENT OF HOMEOWNERSHIP AND ASSET POVERTY IN THE ALABAMA BLACK BELT AND NON-BLACK BELT COUNTIES

    OpenAIRE

    Kanyi, Peter M.; Baharanyi, Ntam; Ngandu, Mudiayi Sylvain; Zabawa, Robert

    2008-01-01

    This study assessed homeownership and how it is affected by race, residency in or out of Alabama Black Belt, family status, poverty and other variables. All variables showed significant relationship to Alabama homeownership with single-parenthood showing a negative impact on White homeownership but insignificant to Black homeownership in the region.

  8. Early Mesozoic granites in the Nanling Belt, South China: Implications for intracontinental tectonics associated with stress regime transformation

    Science.gov (United States)

    Song, Meijia; Shu, Liangshu; Santosh, M.

    2016-04-01

    The link between two tectono-magmatic events during Early and Late Mesozoic periods in the Nanling Belt of South China remains debated. Here we present zircon U-Pb geochronology, Hf isotopes and whole-rock geochemistry of granitic intrusions from Zhuguangshan in the Nanling Belt. The zircon data exhibit two magmatic episodes with 206Pb/238U ages of ca. 230 Ma and 150 Ma, representing the Indosinian (Early-Middle Triassic period) and Early Yanshanian (Jurassic-Cretaceous period) events, respectively. The Indosinian granites are characterized by strongly peraluminous nature with high A/CNK values (> 1.1), whereas the Early Yanshanian granites are weakly peraluminous (average A/CNK value of 1.06). Although the Early Yanshanian granites bear higher HREE contents and lower LREE/HREE ratios, the two-phase granites show enrichment in LREE, Rb, Th, U and Pb, depletion in Eu and negative Ba, Sr, Nb and Ti anomalies. All samples show variably negative εHf(t) values (- 5 to - 16) with two-stage Hf model ages clustered around 1.8-2.1 Ga. Our data indicate that the two-phase granitic magmas were generated from the partial melting of early Paleoproterozoic basement rocks with no input of mantle material. Combined with other geological evidence, we infer that the Indosinian tectono-magmatic event was closely related to intracontinental orogeny triggered by collisions along the boundaries of South China Craton, in relation to processes associated with the E-W trending Tethys tectonic domain. We envisage that the Early Yanshanian event might be a response to the back-arc extension of NW-directed paleo-Pacific plate subduction. The Nanling Belt is a critical zone that records the transformation from Tethys to paleo-Pacific tectonic regimes.

  9. Break the Green Belt? The differences between green belt and its alternative green wedge : A comparative study of London and Stockholm

    OpenAIRE

    Kong, Luyao

    2012-01-01

    The paper sets out to compare two widely applied planning strategies--- green belt and green wedge--- to understand if as an alternative, the green wedge has more strengths than green belt. Green belt has long been the planning policy with a steady position in UK, and also accepted by other countries, Australia, Japan, Korea for example. But during recent years, this policy has been under accusation for fostering un-sustainability, housing shortage and value degradation of the green space. A ...

  10. Organisational conflict: Reflections on managing conflict, identities and values in a selected South African organisation

    OpenAIRE

    Claude-Hélène Mayer; Lynette Louw

    2009-01-01

    This article presents a case study on organisational conflict in a selected international organisation in the South African automotive industry to increase the contextual understanding of the topic. Data was gathered through in-depth interviews with 45 senior and middle managers in the selected international organisation at the head off ce and two branches in Gauteng and at one branch in KwaZulu-Natal. The data analysis was conducted through content analysis as well as triangulation of dat...

  11. South African black generation Y students' perceptions of local black celebrity endorsers' credibility / Boitumelo Vincent Molelekeng

    OpenAIRE

    Molelekeng, Boitumelo Vincent

    2012-01-01

    The use of celebrity endorsers is a popular marketing strategy in many countries. Typically, many marketers believe that using celebrities is a viable marketing strategy for attracting customers, increasing market share and improving sales for their market offerings. The celebrity endorsement strategy using local celebrities is increasing in South Africa. Many South African marketers are now using popular local black celebrities in an attempt to attract the prosperous black emerging middle cl...

  12. Remains of Homo erectus from Bouri, Middle Awash, Ethiopia.

    Science.gov (United States)

    Asfaw, Berhane; Gilbert, W Henry; Beyene, Yonas; Hart, William K; Renne, Paul R; WoldeGabriel, Giday; Vrba, Elisabeth S; White, Tim D

    2002-03-21

    The genesis, evolution and fate of Homo erectus have been explored palaeontologically since the taxon's recognition in the late nineteenth century. Current debate is focused on whether early representatives from Kenya and Georgia should be classified as a separate ancestral species ('H. ergaster'), and whether H. erectus was an exclusively Asian species lineage that went extinct. Lack of resolution of these issues has obscured the place of H. erectus in human evolution. A hominid calvaria and postcranial remains recently recovered from the Dakanihylo Member of the Bouri Formation, Middle Awash, Ethiopia, bear directly on these issues. These approximately 1.0-million-year (Myr)-old Pleistocene sediments contain abundant early Acheulean stone tools and a diverse vertebrate fauna that indicates a predominantly savannah environment. Here we report that the 'Daka' calvaria's metric and morphological attributes centre it firmly within H. erectus. Daka's resemblance to Asian counterparts indicates that the early African and Eurasian fossil hominids represent demes of a widespread palaeospecies. Daka's anatomical intermediacy between earlier and later African fossils provides evidence of evolutionary change. Its temporal and geographic position indicates that African H. erectus was the ancestor of Homo sapiens. PMID:11907576

  13. Prices of second-line antiretroviral treatment for middle-income countries inside versus outside sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Bryony Simmons

    2014-11-01

    Full Text Available Introduction: Antiretrovirals are available at low prices in sub-Saharan Africa, but these prices may not be consistently available for middle-income countries in other regions with large HIV epidemics. Over 30% of HIV infected people live in countries outside sub-Saharan Africa. Several key antiretrovirals are still on patent, with generic production restricted. We assessed price variations for key antiretroviral drugs inside versus outside sub-Saharan Africa. Methods: HIV drug prices used in national programmes (2010–2014 were extracted from the WHO Global Price Reporting Mechanism database for all reporting middle-income countries as classified by the World Bank. Treatment costs (branded and generic were compared for countries inside sub-Saharan Africa versus those outside. Five key second-line antiretrovirals were analysed: abacavir, atazanavir, darunavir, lopinavir/ritonavir, raltegravir. Results: Prices of branded antiretrovirals were significantly higher outside sub-Saharan Africa (p<0.001, adjusted for year of purchase (see Table 1. For example, the median (interquartile range price of darunavir from Janssen was $732 (IQR $732-806 per person-year in sub-Saharan Africa versus $4689 (IQR $4075-5717 in non-African middle-income countries, an increase of 541%. However, when supplied by generic companies, most antiretrovirals were similarly priced between countries in sub-Saharan Africa and other regions. Conclusions: Pharmaceutical companies are selling antiretrovirals to non-African middle-income countries at prices 74–541% higher than African countries with similar gross national incomes. However, generic companies are selling most of these drugs at similar prices across regions. Mechanisms to ensure fair pricing for patented antiretrovirals across both African and non-African middle-income countries need to be improved, to ensure sustainable treatment access.

  14. Large-scale Migration of Fluids toward Foreland Basins during Collisional Orogeny:Evidence from Triassic Anhydrock Sequences and Regional Alteration in the Middle-Lower Yangtze Area

    Institute of Scientific and Technical Information of China (English)

    HOU Zengqian; YANG Zhusen; LI Yinqing; ZENG Pusheng; MENG Yifeng

    2004-01-01

    The middle-lower Yangtze area underwent a series of complex tectonic evolution, such as Hercynian extensional rifting, Indosinian foreland basining, and Yanshanian transpression-transtension, resulting in a large distinctive Cu-Fe-Au metallogenic belt. In the tectonic evolution, large-scale migration and convergence of fluids toward foreland basins induced during the collisional orogeny of the Yangtze and North China continental blocks were of vital importance for the formation of the metallogenic belt. Through geological surveys of the middle-lower Yangtze area,three lines of evidence of large-scale fluid migration are proposed: (1) The extensive dolomitic and silicic alteration penetrating Cambrian-Triassic strata generally occurs in a region sandwiched between the metallogenic belt along the Yangtze River and the Dabie orogenic belt, and in the alteration domain alternately strong and weak alteration zones extend in a NW direction and are controlled by the fault system of the Dabie orogenic belt; it might record the locus of the activities of long-distance migrating fluids. (2) The textures and structures of very thick Middle-Lower Triassic anhydrock sequences in restricted basins along the river reveal the important contribution of the convergence of regional hot brine in restricted basins and the chemical deposition or their formation. (3) Early-Middle Triassic syndepositional iron carbonate sequences and Fe-Cu-Pb-Zn massive sulfide deposits alternate with anhydrock sequences or are separated from the latter, but all of them occur in the same stratigraphic horizon and are intimately associated with each other,being the product of syndeposition of high-salinity hot brine. According to the geological surveys, combined with previous data, the authors propose a conceptual model of fluid migration-convergence and mineralization during the Dabie collisional orogeny.

  15. Mushrooms and Truffles: Historical Biofactories for Complementary Medicine in Africa and in the Middle East

    Directory of Open Access Journals (Sweden)

    Hesham El Enshasy

    2013-01-01

    Full Text Available The ethnopharmaceutical approach is important for the discovery and development of natural product research and requires a deep understanding not only of biometabolites discovery and profiling but also of cultural and social science. For millennia, epigeous macrofungi (mushrooms and hypogeous macrofungi (truffles were considered as precious food in many cultures based on their high nutritional value and characterized pleasant aroma. In African and Middle Eastern cultures, macrofungi have long history as high nutritional food and were widely applied in folk medicine. The purpose of this review is to summarize the available information related to the nutritional and medicinal value of African and Middle Eastern macrofungi and to highlight their application in complementary folk medicine in this part of the world.

  16. Promoting positive youth development by examining the career and educational aspirations of African American males: implications for designing educational programs.

    Science.gov (United States)

    Lee, Felecia A; Lewis, Rhonda K; Sly, Jamilia R; Carmack, Chakema; Roberts, Shani R; Basore, Polly

    2011-01-01

    African American males experience poor academic performance, high absenteeism at school, and are at increased risk of being involved in violence than other racial groups. Given that the educational outlook for African American males appears bleak, it is important to assess the aspirations of these adolescent males in order to find the gap between aspirations and educational attainment. In order to promote positive development within this population, it is essential that factors that affect African American males be identified. A survey was administered to male students attending elementary, middle, and high schools in a local school district. A cross-sectional study was conducted to examine the career and educational aspirations of African American males. A total of 473 males were surveyed: 45% African American, 22% Caucasian, 13% biracial, and 19% Other (including Asian American, Hispanic, Native American). The results revealed that African American males aspired to attend college at the same rate as other ethnic groups. Also, African American males were more likely to aspire to be professional athletes than males from other ethnic groups. Important factors to consider when designing a program are discussed as well as future research and limitations. PMID:21992020

  17. African N Assessment

    Science.gov (United States)

    Bekunda, M.; Galford, G. L.; Hickman, J. E.; Palm, C.

    2011-12-01

    Africa's smallholder agricultural systems face unique challenges in planning for reducing poverty, concurrent with adaptation and mitigation to climate change. At continental level, policy seeks to promote a uniquely African Green Revolution to increase crop yields and food production, and improve local livelihoods. However, the consequences on the environment and climate are not clear; these pro-economic development measures should be linked to climate change adaptation and mitigation measures, and research is required to help achieve these policy proposals by identifying options, and testing impacts. In particular, increased nitrogen (N) inputs are essential for increasing food production in Africa, but are accompanied by inevitable increases in losses to the environment. These losses appear to be low at input levels promoted in agricultural development programs, while the increased N inputs both increase current food production and appear to reduce the vulnerability of food production to changes in climate. We present field and remote sensing evidence from Malawi that subsidizing improved seed and fertilizers increases resilience to drought without adding excess N to the environment. In Kenya, field research identified thresholds in N2O losses, where emissions are very low at fertilization rates of less than 200 kg ha-1. Village-scale models have identified potential inefficiencies in the food production process where the largest losses of reactive N occur, and which could be targeted to reduce the amount of N released to the environment. We further review some on-going research activities and progress in Africa that compare different methods of managing resources that target resilience in food production and adaptation to climate change, using nutrient N as an indicator, while evaluating the effects of these resource management practices on ecosystems and the environment.

  18. African horse sickness.

    Science.gov (United States)

    Mellor, Philip Scott; Hamblin, Christopher

    2004-01-01

    African horse sickness virus (AHSV) causes a non-contagious, infectious insect-borne disease of equids and is endemic in many areas of sub-Saharan Africa and possibly Yemen in the Arabian Peninsula. However, periodically the virus makes excursions beyond its endemic areas and has at times extended as far as India and Pakistan in the east and Spain and Portugal in the west. The vectors are certain species of Culicoides biting midge the most important of which is the Afro-Asiatic species C. imicola. This paper describes the effects that AHSV has on its equid hosts, aspects of its epidemiology, and present and future prospects for control. The distribution of AHSV seems to be governed by a number of factors including the efficiency of control measures, the presence or absence of a long term vertebrate reservoir and, most importantly, the prevalence and seasonal incidence of the major vector which is controlled by climate. However, with the advent of climate-change the major vector, C. imicola, has now significantly extended its range northwards to include much of Portugal, Spain, Italy and Greece and has even been recorded from southern Switzerland. Furthermore, in many of these new locations the insect is present and active throughout the entire year. With the related bluetongue virus, which utilises the same vector species of Culicoides this has, since 1998, precipitated the worst outbreaks of bluetongue disease ever recorded with the virus extending further north in Europe than ever before and apparently becoming endemic in that continent. The prospects for similar changes in the epidemiology and distribution of AHSV are discussed.

  19. The transmission of African culture to children

    OpenAIRE

    Michele Tanon Lora

    2014-01-01

    African ancient traditions suffered a major historical change as a result of colonization. Several decades after decolonization and access to independence, what is the situation and place of the African culture in Africa and outside Africa? Does African culture perpetuate effectively today? What are the obstacles to the transmission of African culture to our children? What are the beliefs or elements that have influenced the transmission of our culture after the period of independence? Roughl...

  20. Translating Culture: Contemporary African American Poetry

    OpenAIRE

    Kristina Kočan Šalamon

    2015-01-01

    The paper interrogates cultural specifics of contemporary African American poetry and exhibits translation problems when translating this poetic work. African American writers have always included much of their cultural heritage in their writing and this is immediately noticed by a translator. The cultural elements, such as African American cuisine, attire and style in general, as well as spiritual and religious practices, often play a significant role for African American poets who are procl...

  1. Dynamics of the earth's radiation belts and inner magnetosphere (geophysical monograph series)

    CERN Document Server

    2013-01-01

    Dynamics of the Earth's Radiation Belts and Inner Magnetosphere draws together current knowledge of the radiation belts prior to the launch of Radiation Belt Storm Probes (RPSP) and other imminent space missions, making this volume timely and unique. The volume will serve as a useful benchmark at this exciting and pivotal period in radiation belt research in advance of the new discoveries that the RPSP mission will surely bring. Highlights include the following: a review of the current state of the art of radiation belt science; a complete and up-to-date account of the wave-particle interactions that control the dynamical acceleration and loss processes of particles in the Earth's radiation belts and inner magnetosphere; a discussion emphasizing the importance of the cross-energy coupling of the particle populations of the radiation belts, ring current, and plasmasphere in controlling the dynamics of the inner magnetosphe...

  2. DEVELOPMENT OF THE TEST METHODS OF THE CONVEYOR BELTS USED IN ENVIRONMENTS ENDANGERED BY EXPLOSION HAZARDS

    Directory of Open Access Journals (Sweden)

    Florin Adrian PĂUN

    2012-05-01

    Full Text Available Conveyor belts are used for a long period of time in the industry branches where potentially explosive atmospheres could occur. Dangerous phenomena which can be in direct connection with the use of conveyor belts are the ones regarding: - sparks influence over the coating layer and/or resistance internal structure of the stopped conveyor belt; - propagation of a flame along the length of a conveyor belt that was exposed to a energy source relative high like a fire or due to blockage of a conveyor belt as a result of the driving mechanism still operating, that generate a local heating of the conveyor belt in contact with the driving drum, rollers or any other heating source generated by friction. Determining the safety parameters characteristic of the conveyor belts by employing test methods allows assessment of the safety level as well as certification of their explosion protection quality when used in environments with explosion danger.

  3. Transverse myelitis due to trypanosomiasis in a middle aged Tanzanian man

    OpenAIRE

    Kibiki, G S; Murphy, D K

    2006-01-01

    We report the case of a middle aged Tanzanian man who developed a spinal cord syndrome over 6 weeks, along with a mild encephalopathy. Investigations ruled out the usual major causes of such a syndrome in our setting in northern Tanzania. Examination of his cerebrospinal fluid revealed trypanosomes, and he made a slow but dramatic improvement after a full course of suramine and melarsoprol. We postulate that he had a transverse myelitis due to African trypanosomiasis, a rare and barely recogn...

  4. Islamic Banking in the Middle-East and North-Africa (MENA) Region

    OpenAIRE

    Syed Ali, Salman

    2012-01-01

    Islamic finance has now become an important element in the development agenda of the Middle East and North African (MENA) countries. It is also gaining significance in the financial landscape of the region as well as of the individual countries. As a growing business it caters to the financial needs of the people without conflicting with their social and religious values. Despite this reality, little systematic and consistent analysis exists in the literature on the asset and liability struct...

  5. Long-term landscape evolution of the South Atlantic passive continental margin along the Kaoko- and Damara Belts, NW-Namibia

    Science.gov (United States)

    Menges, Daniel; Glasmacher, Ulrich Anton; Hackspacher, Peter; Schneider, Gabriele; Salomon, Eric

    2015-04-01

    The Kaoko Belt in northwestern Namibia originates in the collision of the Rio de la Plata and Kongo Craton during the Pan-African Orogeny in the Neoproterozoic (1) and represents the northern arm of the Damara Orogen. NW-Namibias continental crust mainly consists of the NE-SW striking intracontinental branch of the Pan-African Damara mobile belt, which separates the Congo from the Kalahari craton. The Damara Orogen is divided into several tectonostratigraphic zones that are bounded by steeply dipping, ductile shear zones. These regional lineaments can be traced at least 150 km offshore (2). The lithostratigraphic units consist of Proterozoic and Cambrian metamorphosed rocks (534 (7) Ma - 481 (25) Ma (3) as well as Mesozoic sedimentary and igneous rocks. From Permo-Carboniferous to Mid Jurassic northern Namibia was affected by deep erosion of the Damara Orogen, Permo-Triassic collisional processes along the southern margin of Gondwana and eastern margin of Africa (4), and the deposition of the Nama Group sediments and the Karoo megasequence (5). Between the Otjihorongo and the Omaruru Lineament-Waterberg Thrust early Mesozoic tectonic activity is recorded by coarse clastic sediments deposited within NE trending half-graben structures. The Early Jurassic Karoo flood basalt lavas erupted rapidly at 183±1 Ma (6). The Early Cretaceous Paraná-Etendeka flood basalts (132±1 Ma) and mafic dike swarms mark the rift stage of the opening of the South Atlantic (7). Early Cretaceous alkaline intrusions (137-124 Ma) occur preferentially along Mesozoic half-graben structures and are called the Damaraland Igneous Province (8). Late Cretaceous alkaline intrusions and kimberlite pipes occur in northern Namibia. Post Early Paleocene siliciclastic sedimentation in Namibia was largely restricted to a 150 km wide zone (9) and is represented by the Tsondab Sandstone Formation (~ 300 m thickness). The oldest part has an age of early Paleocene and the upper part span from middle Miocene

  6. African American Teaching and the Matriarchal Performance.

    Science.gov (United States)

    Jeffries, Rhonda Baynes

    This paper discusses the role of matriarchs in African-American culture, explaining that traditionally, African-American matriarchs arise from a combination of African norms and American social positions that naturally forces them to assume leadership conditions. The roles these women assume are a response to the desire to survive in a society…

  7. African pastoralist systems: An integrated approach

    OpenAIRE

    Fratkin, E.; Galvin, K.A.; Roth, E.A.

    1994-01-01

    Metadata only record The chapters in this book cover the following topics: Archaeological Perspectives on East African Pastoralism; Pastoralism in Historic Perspective; Mobility and Land Use Among African Pastoralists: Old Conceptual Problems and New Interpretations; Labor, Livestock, and Land: The Organization of Pastoral Production; Diet, Nutrition, and Pastoral Strategy; Demographic Systems: Two East African Examples; Child Fostering Among Nomadic Turkana Pastoralists: Demographic and H...

  8. The African American Image in American Cinema.

    Science.gov (United States)

    Bourne, St. Clair

    1990-01-01

    Political conditions have influenced the screen images of U.S. cinema, and the images of African Americans have reflected prevailing social stereotypes. The history of African-American representation in films is traced, and it is noted that the tendency to portray African Americans stereotypically has not changed. (SLD)

  9. MORE CHINESE CARS ON AFRICAN ROADS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China drives into the African vehicle market and meets the challenges head on with some advantages of its own High-quality but inexpensive Chinese automobiles have gradually won the confidence of the African market and are becoming a bright new link in Sino-African economic ties. On September 4, a total of 400 Polarsun minibuses, made in Shenyang, capital of northeast

  10. African Centered Knowledge: A British Perspective.

    Science.gov (United States)

    Christian, Mark

    2001-01-01

    Considers the impact of African centered knowledge within the United Kingdom. Recent development of African Diaspora studies has forged links between various black Atlantic communities. The United Kingdom has experienced positive grassroots community response to the work of noted African centered scholars, yet within the British academy,…

  11. Late Middle Eocene primate from Myanmar and the initial anthropoid colonization of Africa.

    Science.gov (United States)

    Chaimanee, Yaowalak; Chavasseau, Olivier; Beard, K Christopher; Kyaw, Aung Aung; Soe, Aung Naing; Sein, Chit; Lazzari, Vincent; Marivaux, Laurent; Marandat, Bernard; Swe, Myat; Rugbumrung, Mana; Lwin, Thit; Valentin, Xavier; Zin-Maung-Maung-Thein; Jaeger, Jean-Jacques

    2012-06-26

    Reconstructing the origin and early evolutionary history of anthropoid primates (monkeys, apes, and humans) is a current focus of paleoprimatology. Although earlier hypotheses frequently supported an African origin for anthropoids, recent discoveries of older and phylogenetically more basal fossils in China and Myanmar indicate that the group originated in Asia. Given the Oligocene-Recent history of African anthropoids, the colonization of Africa by early anthropoids hailing from Asia was a decisive event in primate evolution. However, the fossil record has so far failed to constrain the nature and timing of this pivotal event. Here we describe a fossil primate from the late middle Eocene Pondaung Formation of Myanmar, Afrasia djijidae gen. et sp. nov., that is remarkably similar to, yet dentally more primitive than, the roughly contemporaneous North African anthropoid Afrotarsius. Phylogenetic analysis suggests that Afrasia and Afrotarsius are sister taxa within a basal anthropoid clade designated as the infraorder Eosimiiformes. Current knowledge of eosimiiform relationships and their distribution through space and time suggests that members of this clade dispersed from Asia to Africa sometime during the middle Eocene, shortly before their first appearance in the African fossil record. Crown anthropoids and their nearest fossil relatives do not appear to be specially related to Afrotarsius, suggesting one or more additional episodes of dispersal from Asia to Africa. Hystricognathous rodents, anthracotheres, and possibly other Asian mammal groups seem to have colonized Africa at roughly the same time or shortly after anthropoids gained their first toehold there.

  12. Thermal Field Analysis and Simulation of an Infrared Belt Furnace Used for Solar Cells

    Directory of Open Access Journals (Sweden)

    Bai Lu

    2014-01-01

    Full Text Available During solar cell firing, volatile organic compounds (VOC and a small number of metal particles were removed using the gas flow. When the gas flow was disturbed by the thermal field of infrared belt furnace and structure, the metal particles in the discharging gas flow randomly adhered to the surface of solar cell, possibly causing contamination. Meanwhile, the gas flow also affected the thermal uniformity of the solar cell. In this paper, the heating mechanism of the solar cell caused by radiation, convection, and conduction during firing was analyzed. Afterward, four 2-dimensional (2D models of the furnace were proposed. The transient thermal fields with different gas inlets, outlets, and internal structures were simulated. The thermal fields and the temperature of the solar cell could remain stable and uniform when the gas outlets were installed at the ends and in the middle of the furnace, with the gas inlets being distributed evenly. To verify the results, we produced four types of furnaces according to the four simulated results. The experimental results indicated that the thermal distribution of the furnace and the characteristics of the solar cells were consistent with the simulation. These experiments improved the efficiency of the solar cells while optimizing the solar cell manufacturing equipment.

  13. A comprehensive phylogeography of the Hyles euphorbiae complex (Lepidoptera: Sphingidae) indicates a 'glacial refuge belt'.

    Science.gov (United States)

    Mende, Michael B; Bartel, Manuela; Hundsdoerfer, Anna K

    2016-01-01

    We test the morphology based hypothesis that the Western Palaearctic spurge hawkmoths represent two species, the Eurasian H. euphorbiae and Afro-Macaronesian H. tithymali. It has been suggested that these species merged into several hybrid swarm populations, although a mitochondrial phylogeography revealed substructure with local differentiation. We analysed a three-gene mt-dataset (889 individuals) and 12 microsatellite loci (892 individuals). Microsatellite analyses revealed an overall weak differentiation and corroborated the superordinate division into two clusters. The data indicate that the populations studied belong to only one species according to the biological species concept, refuting the opening hypothesis. A future taxonomic revision appears necessary to reflect the division into two subgroups. Ancestral mitochondrial polymorphisms are retained in H. euphorbiae, indicating gene flow within a broad 'glacial refuge belt' and ongoing postglacial gene flow. Diverse patterns of extensive mito-nuclear discordance in the Mediterranean and the Middle East presumably evolved by more recent processes. This discordance indicates introgression of H. tithymali-related mitochondrial haplogroups, accompanied (to a lesser degree) by nuclear alleles, into Italian and Aegean H. euphorbiae populations as recently as the late Holocene. The complex mosaic of divergence and reintegration is assumed to have been influenced by locally differing environmental barriers to gene flow. PMID:27439775

  14. Middle East gas

    International Nuclear Information System (INIS)

    Despite the significant contribution of the Middle East countries of Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia and the United Arab Emirates in the Arabia Gulf to the world's oil output, they are placing increasing emphasis on natural gas as a source of exports and to fuel domestic economic growth. The region accounts for 35% of the world's proven gas resource base, with Iran and Qatar holding major reserves. The region is becoming increasingly important in global liquefied natural gas (LNG) trade and details of key LNG projects and the major players in this area are given; a key advantage is the region's position between the two main markets - the Asia Pacific and the Atlantic Basin. Brief details are also given of gas pipeline projects and gas-to-liquid (GTL) projects in the region

  15. Tribological Properties of Metal V-Belt Type CVT Lubricant

    Directory of Open Access Journals (Sweden)

    Keiichi Narita

    2012-01-01

    Full Text Available The priority for lubricant performance for metal V-belt-type CVT (B-CVTFs should be the improvement of transmittable torque capacity between the belt and pulley plus excellent antishudder properties for lockup clutch used in B-CVTs. This study intends to investigate the effect of lubricant additives for improving these performances of B-CVTs. In addition, surface analysis techniques were utilized to gain a novel insight into the chemical composites and morphology of the tribofilms. As a result, it is vital for greater torque capacity to give higher boundary friction coefficient between the metal contacting interfaces, and the process of boundary lubricant film formation derived from antiwear additives used in B-CVTFs strongly impacts on the torque capacity. Moreover, it is found that a sort of lubricant formulation gave an excellent antishudder performance for wet clutch with keeping higher friction coefficient between the metals, which would result in improving the performance of B-CVTs.

  16. MINIMIZATION OF CORD WASTAGES IN BELT INDUSTRY USING DMAIC

    Directory of Open Access Journals (Sweden)

    SHAILESH N. KHEKALE,

    2010-08-01

    Full Text Available Manufacturing processes tend to produce operational wastages due to various reasons, which can be reduced by identifying and eliminating those using Six Sigma methodologies. In the presented work, DMAIC (Define, Measure, Analyze, Improve and Control has been used to reduce cord wastages in belt manufacturing. Core issues, pain areas or processes related to cord wastages are identified to formulate the problem. Later the concerned data is collected to examine the current performance and process capability; also the root causes are identified. Solutions are found out from improvement point of view, and various tools are properly implemented for tracking the processes. This study reports reduction in cord wastages in belt manufacturing through reduction in DPMO (Defects per Million Opportunities from 549531 to 17240, also the Sigma Level isimproved from 1.37 to 3.6.

  17. Statistical properties of the radiation belt seed population

    Science.gov (United States)

    Boyd, A. J.; Spence, H. E.; Huang, C.-L.; Reeves, G. D.; Baker, D. N.; Turner, D. L.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.; Shprits, Y. Y.

    2016-08-01

    We present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular, we investigate the relationship between the tens and hundreds of keV seed electrons and >1 MeV core radiation belt electron population. Using a cross-correlation analysis, we find that the seed and core populations are well correlated with a coefficient of ≈0.73 with a time lag of 10-15 h. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of penetration of the seed population determines the inner boundary of the acceleration process. However, we show that an enhanced seed population alone is not enough to produce acceleration in the higher energies, implying that the seed population of hundreds of keV electrons is only one of several conditions required for MeV electron radiation belt acceleration.

  18. Operational experiences with belt rollers for bulk conveying

    Energy Technology Data Exchange (ETDEWEB)

    Dietl, W.

    1982-05-01

    Explains the design of belt rollers produced by TAKRAF for conveyor belts 0.3 m to 3.0 m wide. Light, medium and heavy-duty rollers are manufactured according to a common basic design; the roller diameters range from 63 mm to 245 mm. Major parameters of rollers are discussed, the theoretical roller service life is calculated. Operational conditions which must be observed in order to obtain the theoretical service life in operation are listed. The principle design of the roller is demonstrated in a scheme, focusing on the axial labyrinth seal. Impact forces on rollers at conveyor feeding stations are analyzed. Tests have been carried out using rollers provided with shock absorbing rubber elements compensating the impact load of the bulk, which, however, did not prove to be advantageous. Conclusions on the design of heavy duty rollers to be used at feeding stations are further outlined. (3 refs.) (In German)

  19. The Analysis of Insects Population on Fields in Forest Belts

    OpenAIRE

    Gribust Irina Romuvaldovna

    2014-01-01

    The introduction into the agricultural and ecological system of multifunctional forest belts contributes to the formation of a qualitatively new environment, and, as a consequence, to the transformation of insects populations. Change of the faunal diversity in transformed agro-ecosystems and identification of entomofauna characteristics by a number of biotic indices, which undergo cumulative impact of organized farm ecosystem components, have not been sufficiently studied. This question is th...

  20. Discovery of the candidate Kuiper belt object 1992 QB1

    Science.gov (United States)

    Jewitt, David; Luu, Jane

    1993-01-01

    The discovery of a new faint object in the outer solar system, 1992 QB1, moving beyond the orbit of Neptune is reported. It is suggested that the 1992 QB1 may represent the first detection of a member of the Kuiper belt (Edgworth, 1949; Kuiper, 1951), the hypothesized population of objects beyond Neptune and a possible source of the short-period comets, as suggested by Whipple (1964), Fernandez (1980), and Duncan et al. (1988).

  1. Radiation Belt Electron Dynamics Driven by Large-Amplitude Whistlers

    Science.gov (United States)

    Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.

    2013-01-01

    Acceleration of radiation belt electrons driven by oblique large-amplitude whistler waves is studied. We show analytically and numerically that this is a stochastic process; the intensity of which depends on the wave power modified by Bessel functions. The type of this dependence is determined by the character of the nonlinear interaction due to coupling between action and phase. The results show that physically significant quantities have a relatively weak dependence on the wave power.

  2. Future aerosol reductions and widening of the northern tropical belt

    Science.gov (United States)

    Allen, Robert J.; Ajoku, Osinachi

    2016-06-01

    Observations show that the tropical belt has widened over the past few decades, a phenomenon associated with poleward migration of subtropical dry zones and large-scale atmospheric circulation. Although part of this signal is related to natural climate variability, studies have identified an externally forced contribution primarily associated with greenhouse gases (GHGs) and stratospheric ozone loss. Here we show that the increase in aerosols over the twentieth century has led to contraction of the northern tropical belt, thereby offsetting part of the widening associated with the increase in GHGs. Over the 21st century, however, when aerosol emissions are projected to decrease, the effects of aerosols and GHGs reinforce one another, both contributing to widening of the northern tropical belt. Models that have larger aerosol forcing, by including aerosol indirect effects on cloud albedo and lifetime, yield significantly larger Northern Hemisphere (NH) tropical widening than models with direct aerosol effects only. More targeted simulations show that future reductions in aerosols can drive NH tropical widening as large as greenhouse gases, and idealized simulations show the importance of NH midlatitude aerosol forcing. Mechanistically, the 21st century reduction in aerosols peaks near 40°N, which results in a corresponding maximum increase in surface solar radiation, NH midlatitude tropospheric warming amplification, and a poleward shift in the latitude of maximum baroclinicity, implying a corresponding shift in atmospheric circulation. If models with aerosol indirect effects better represent the real world, then future aerosol changes are likely to be an important -- if not dominant -- driver of NH tropical belt widening.

  3. Development of a new Global RAdiation Belt model: GRAB

    Science.gov (United States)

    Sicard-Piet, Angelica; Lazaro, Didier; Maget, Vincent; Rolland, Guy; Ecoffet, Robert; Bourdarie, Sébastien; Boscher, Daniel; Standarovski, Denis

    2016-07-01

    The well known AP8 and AE8 NASA models are commonly used in the industry to specify the radiation belt environment. Unfortunately, there are some limitations in the use of these models, first due to the covered energy range, but also because in some regions of space, there are discrepancies between the predicted average values and the measurements. Therefore, our aim is to develop a radiation belt model, covering a large region of space and energy, from LEO altitudes to GEO and above, and from plasma to relativistic particles. The aim for the first version is to correct the AP8 and AE8 models where they are deficient or not defined. At geostationary, we developed ten years ago for electrons the IGE-2006 model which was proven to be more accurate than AE8, and used commonly in the industry, covering a broad energy range, from 1keV to 5MeV. From then, a proton model for geostationary orbit was also developed for material applications, followed by the OZONE model covering a narrower energy range but the whole outer electron belt, a SLOT model to asses average electron values for 2file system to switch between models, in order to obtain at each location in space and energy point the most reliable value. Of course, the way the model is developed is well suited to add new local developments or to include international partnership. This model will be called the GRAB model, as Global Radiation Belt model. We will present first beta version during this conference.

  4. The benefit of seat belt legislation in the United Kingdom.

    OpenAIRE

    M. McCarthy

    1989-01-01

    Legislation for compulsory wearing of seat belts by car drivers and front seat passengers has been acclaimed as a major public health advance. Reports from other countries, and two recent evaluative studies in the United Kingdom, have suggested that legislation reduces both deaths and injuries. To assess the effect of the UK law 5 years after its implementation, trends in routine data for 1976-1987 have been reviewed. There were two sources of data: mortality statistics, published by the Offi...

  5. Coralling a distant planet with extreme resonant Kuiper belt objects

    CERN Document Server

    Malhotra, Renu; Wang, Xianyu

    2016-01-01

    The four longest period Kuiper belt objects have orbital periods close to small integer ratios with each other. A hypothetical planet with orbital period $\\sim$17,117 years, semimajor axis $\\sim$665 AU, would have N/1 and N/2 period ratios with these four objects. The orbital geometries and dynamics of resonant orbits constrain the orbital plane, the orbital eccentricity and the mass of such a planet, as well as its current location in its orbital path.

  6. Rotation Period Determination of Four Main-belt Asteroids

    Science.gov (United States)

    Ferrero, Andrea

    2016-10-01

    Observations of four main-belt asteroids (MBA) revealed the following rotation periods and lightcurve amplitudes: 3861 Lorenz, P = 11.91 ± 0.01 h, A = 0.28 mag; 6173 Jimwestphal P = 2.908 ± 0.001 h, A = 0.41 mag; 10259 Osipovyurij, P = 6.356 ± 0.001 h, A = 0.30 mag; 29470 Higgs, P = 36.31 ± 0.01 h, A = 0.48 mag.

  7. How student teachers understand African philosophy

    Directory of Open Access Journals (Sweden)

    Matsephe M. Letseka

    2012-10-01

    Full Text Available The question ‘What constitutes African philosophy?’ was first raised with the publication of Placide Tempels’s seminal work Bantu philosophy in 1959. Tempels’s book inevitably elicited considerable critical response from African philosophers, which culminated in a wide range of publications such as Wiredu’s (1980 Philosophy and an African culture, Hountondji’s (1983 African philosophy: Myth and reality, Oruka’s (1990 Sage philosophy: Indigenous thinkers and modern debate on African philosophy, Shutte’s (1993 Philosophy for Africa, Masolo’s (1994 African philosophy in search of identity and Gyekye’s (1995 An essay of African philosophical thought: The Akan conceptual scheme. It has been over 60 years since the publication of Temples’s book and there continues to be serious debate about African philosophy. This article sought to contribute to the debate on the various conceptions of African philosophy, but with a focus on the challenges of teaching African philosophy to Philosophy of Education students at an open distance learning institution in South Africa. This article discussed the tendency amongst undergraduate Philosophy of Education students to conflate and reduce African philosophy to African cultures and traditions, and to the notion of ubuntu, and sought to understand the reasons for students’ inclination to treat African philosophy in this way. It examined students’ background knowledge of African philosophy, their critical thinking skills and whether their official study materials are selected and packaged in a manner that, in fact, adds to the challenges they face. Finally, the article explored the ways in which Philosophy of Education lecturers can adapt their pedagogy to provide students with a better understanding of African philosophy.

  8. Vestiges of an Ordovician west-vergent thin-skinned Ocloyic thrust belt in the Argentine Precordillera, southern Central Andes

    Science.gov (United States)

    Thomas, William A.; Astini, Ricardo A.

    2007-08-01

    Collision of the down-going, Laurentia-derived Argentine Precordillera terrane with the Gondwanan margin drove the Ordovician Ocloyic orogeny, including subduction volcanism, metamorphism, and top-to-west shearing east of the Precordillera. In the Precordillera, above passive-margin carbonates (Lower Ordovician San Juan Limestone and older carbonates), a Middle to Upper Ordovician westward-prograding synorogenic clastic wedge of black shale (Gualcamayo Shale) and coarser clastic sediment (Las Vacas Conglomerate and Trapiche Formation) fills a peripheral foreland basin. New research has identified vestiges of a west-directed thin-skinned Ocloyic foreland thrust belt that has been fragmented by east-directed Andean thrusting. The El Corral thrust sheet, with hanging-wall detachment in the San Juan Limestone, extends over a west-directed footwall frontal ramp and extensive flat to low-angle footwall cutoff in the Gualcamayo and Las Vacas formations. Las Vacas conglomerates in the footwall include olistoliths (10-m scale) exclusively of San Juan Limestone and Gualcamayo Shale; the beds in some olistoliths are folded. The advancing El Corral thrust sheet successively supplied and overrode the stratigraphically restricted olistoliths. In the El Corral footwall, tight west-vergent folds and faults within an anticlinorium in the San Juan Limestone and Gualcamayo Shale suggest a deeper (unexposed) thrust fault, the Los Celestitos fault. West of the anticlinorium, easterly dip (restored to remove Andean deformation) beneath an angular unconformity between Las Vacas and Trapiche beds is consistent geometrically with the trailing limb of a west-vergent fault-propagation anticline in the hanging wall of the subsurface Los Celestitos fault. The same angular unconformity truncates the El Corral fault and hanging-wall strata. In the Trapiche Formation, contrasting sedimentary facies from sandy turbidites westward to limestone-clast megabeds and olistoliths suggest another frontal

  9. Calculus in the Middle School?

    Science.gov (United States)

    Barger, Rita H.; McCoy, Ann C.

    2010-01-01

    This article presents an example of how middle school teachers can lay a foundation for calculus. Although many middle school activities connect directly to calculus concepts, the authors have decided to look in depth at only one: the concept of change. They will show how teachers can lead their students to see and appreciate the calculus…

  10. Inner radiation belt source of helium and heavy hydrogen isotopes

    Science.gov (United States)

    Leonov, A. A.; Galper, A. M.; Koldashov, S. V.; Mikhailov, V. V.; Casolino, M.; Picozza, P.; Sparvoli, R.

    Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the main source of energetic H and He isotopes nuclei in the radiation belt. This paper reports on the specified calculations of these isotope intensities using various inner zone proton intensity models (AP-8 and SAMPEX/PET PSB97), the atmosphere drift-averaged composition and density model MSIS-90, and cross-sections of the interaction processes from the GNASH nuclear model code. To calculate drift-averaged densities and energy losses of secondaries, the particles were tracked in the geomagnetic field (modelled through IGRF-95) by integrating numerically the equation of the motion. The calculations take into account the kinematics of nuclear interactions along the whole trajectory of trapped proton. The comparison with new data obtained from the experiments on board RESURS-04 and MITA satellites and with data from SAMPEX and CRRES satellites taken during different phases of solar activity shows that the upper atmosphere is a sufficient source for inner zone helium and heavy hydrogen isotopes. The calculation results are energy spectra and angular distributions of light nuclear isotopes in the inner radiation belt that may be used to develop helium inner radiation belt model and to evaluate their contribution to SEU (single event upset) rates.

  11. Investigating radiation belt losses though numerical modelling of precipitating fluxes

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2004-11-01

    Full Text Available It has been suggested that whistler-induced electron precipitation (WEP may be the most significant inner radiation belt loss process for some electron energy ranges. One area of uncertainty lies in identifying a typical estimate of the precipitating fluxes from the examples given in the literature to date. Here we aim to solve this difficulty through modelling satellite and ground-based observations of onset and decay of the precipitation and its effects in the ionosphere by examining WEP-produced Trimpi perturbations in subionospheric VLF transmissions. In this study we find that typical Trimpi are well described by the effects of WEP spectra derived from the AE-5 inner radiation belt model for typical precipitating energy fluxes. This confirms the validity of the radiation belt lifetimes determined in previous studies using these flux parameters. We find that the large variation in observed Trimpi perturbation size occurring over time scales of minutes to hours is primarily due to differing precipitation flux levels rather than changing WEP spectra. Finally, we show that high-time resolution measurements during the onset of Trimpi perturbations should provide a useful signature for discriminating WEP Trimpi from non-WEP Trimpi, due to the pulsed nature of the WEP arrival.

  12. An Experimental Concept for Probing Nonlinear Radiation Belt Physics

    Science.gov (United States)

    Amatucci, Bill; Ganguli, Guru; Crabtree, Chris; Mithaiwala, Manish; Siefring, Carl; Tejero, Erik

    2014-10-01

    The SMART sounding rocket is designed to probe the nonlinear response of a known ionospheric stimulus. High-speed neutral barium atoms generated by a shaped charge explosion perpendicular to the magnetic field in the ionosphere form a ring velocity distribution of photo-ionized Ba+ that will generate lower hybrid waves. Induced nonlinear scattering of lower hybrid waves into whistler/magnetosonic waves has been theoretically predicted, confirmed by simulations, and observed in the lab. The effects of nonlinear scattering on wave evolution and whistler escape to the radiation belts have been studied and observable signatures quantified. The fraction of the neutral atom kinetic energy converted into waves is estimated at 10-12%. SMART will carry a Ba release module and an instrumented daughter section with vector wave magnetic and electric field sensors, Langmuir probes and energetic particle detectors to determine wave spectra in the source region and detect precipitated particles. The Van Allen Probes can detect the propagation of the scattered whistlers and their effects in the radiation belts. By measuring the radiation belt whistler energy density, SMART will confirm the nonlinear scattering process and the connection to weak turbulence. Supported by the Naval Research Laboratory Base Funds.

  13. Periodicity in tree rings from the corn belt.

    Science.gov (United States)

    Meko, D M; Stockton, C W; Blasing, T J

    1985-07-26

    Previous tree-ring studies indicated that the total area affected by drought in the western United States has rhythmically expanded and contracted over the past 300 years, with a period near the 18.6-year lunar nodal and 22-year double-sunspot cycles. Recently collected tree-ring data from the U.S. Corn Belt for the years 1680 to 1980 were examined for evidence of either of these cycles on a regional scale. Spectral analysis indicated no periodicity in the eastern part of the Corn Belt, but a significant 18.33-year period in the western part. The period length changed from 17.60 to 20.95 years between the first 150 years and the last 151. High-resolution frequency analysis showed that the structure of the 18.33-year spectral peak was complex, with contributions from several frequencies near both the lunar nodal and double-sunspot periods. A t-test of difference of means in reconstructed annual precipitation weakly corroborated a previous finding of an association between drought area and the phase of the double-sunspot cycle. Both the high-resolution frequency analysis and the t-test results indicate that the periodic component of drought near 20 years is too weak and irregular to be of use in drought forecasting for the Corn Belt.

  14. Detection of Small Kuiper Belt Objects by Stellar Occultations

    CERN Document Server

    Stevenson, R

    2007-01-01

    Knowledge of the Kuiper Belt is currently limited to those objects that can be detected directly. Objects with diameters less than $\\sim$10km reflect too little light to be detected. These smaller bodies could contain most of the mass in the Kuiper Belt while the abundance of these bodies may constrain the distribution of mass. The overall size distribution of bodies within the Kuiper Belt can also be inferred from the relative abundances of sub-km and larger bodies. Stellar occultations are already used to study dark objects in the Solar System, such as asteroids or planetary rings. Occultation by a KBO of a size comparable to, or larger than, that of the Fresnel Scale will result in Fresnel diffraction. Detection of diffraction effects requires fast multiple-star photometry, which will be conducted in July 2007 using the Orthogonal Parallel Transfer Imaging Camera (OPTIC) mounted on the University of Hawaii 2.2m telescope on Mauna Kea. This paper details how knowledge of the mass and structure of the outer ...

  15. Non-Vestoid candidates in the inner Main Belt

    Science.gov (United States)

    Moskovitz, Nicholas; Oszkiewicz, Dagmara; Skiff, Brian; Kankiewicz, Pawel; Licandro, Javier; Galiazzo, Mattia; Zeilinger, Werner

    2016-10-01

    Most Howardite-Eucrite-Diogenite (HED) meteorites (analogues to V-type asteroids) are thought to originate from asteroid (4) Vesta. However some HEDs show distinct oxygen isotope ratios and therefore are thought to originate from other asteroids. In this study we try to identify asteroids that may represent parent bodies of those mismatching HEDs. In particular the origin of the anomalous Bunburra Rockhole meteorite was traced back to the inner main asteroid belt, showing that there might be asteroids that are not genetically linked to the asteroid (4) Vesta (the main source of V-type asteroids and HED meteorites) in the inner main belt. In this work we identify V-type asteroids outside the dynamical Vesta family whose rotational properties (retrograde vs prograde rotation) suggest the direction of Yarkovsky drift that sets them apart from typical Vestoids and Vesta fugitives. Specificly Nesvorny et al. 2008 simulated escapes paths from the Vesta family and showed that typical Vesta fugitives in the inner main asteroid belt at semi-major axis a drift or showing Yarkovsky drift direction towards (4) Vesta are the best candidates for non-Vestoidal V-type asteroids and therefore parent bodies of anomalous HED. In this study we have performed accurate photometric observations and determined sense of rotation for several asteroids testing their links to Vesta and anomalous HED. We have found several potential non-Vestoid candidates. Those objects have to be studied in more detail to fully confirm their link to anomalous HEDs.

  16. Collisional Grooming Models of the Kuiper Belt Dust Cloud

    CERN Document Server

    Kuchner, Marc J

    2010-01-01

    We modeled the 3-D structure of the Kuiper Belt dust cloud at four different dust production rates, incorporating both planet-dust interactions and grain-grain collisions using the collisional grooming algorithm. Simulated images of a model with a face-on optical depth of ~10^-4 primarily show an azimuthally-symmetric ring at 40-47 AU in submillimeter and infrared wavelengths; this ring is associated with the cold classical Kuiper Belt. For models with lower optical depths (10^-6 and 10^-7), synthetic infrared images show that the ring widens and a gap opens in the ring at the location of of Neptune; this feature is caused by trapping of dust grains in Neptune's mean motion resonances. At low optical depths, a secondary ring also appears associated with the hole cleared in the center of the disk by Saturn. Our simulations, which incorporate 25 different grain sizes, illustrate that grain-grain collisions are important in sculpting today's Kuiper Belt dust, and probably other aspects of the Solar System dust c...

  17. Tectonic evolution of the Irtysh collision belt: New zircon U-Pb ages of deformed and collisional granitoids in the Kalaxiangar area, NW China

    Science.gov (United States)

    Tao, Hong; Jun, Gao; Xingwang, Xu; Klemd, Reiner

    2016-04-01

    The CAOB is thought to have formed by multiple accretion and collision of various microcontinents, island arcs, oceanic plateaus and accretionary wedges due to the closure of the Paleo-Asia Ocean [1, 2, 3]. The Irtysh collision belt is located at the middle-western part of the CAOB and generally thought to be the result of the collision of the Sawuer Island arc and the Altay Terrane, subsequent to the consumption of the Early Paleozoic Junggar Ocean, a branch of Paleo-Asia Ocean. Therefore, the exact timing of the Irtysh collision belt is crucial for a better understanding of the tectonic evolution of this collision belt and will provide constraints on the evolution of the CAOB. Recently, we discovered various collisional granitoids in the Kalaxiangar tectonic belt (KTB), which is located in the eastern part of the Irtysh collision belt. In this contribution, we report new geochemical whole-rock, zircon U-Pb and Hf isotopic data of the arc-related and collisional granitoids. Our new results reveal that 1) the arc-related granodioritic porphyries formed at ca. 374 Ma. Furthermore, recrystallized zircons from the granodioritic mylonite and ultramylonite of the Laoshankou ductile deformation zone have a similar U-Pb age of ca. 360 Ma; 2) the syn-collisional granodioritic porphyries, which distribute along cleavege, were emplaced at ca. 355 Ma; 3) the post-collisional A-type granodioritic porphyry, which cuts the NW-NNW trending schistosity at a low angle, has an age of ca. 323 Ma, ɛHf(t) values from + 7.5 to + 14.4, and young Hf model ages between 387 and 658 Ma; 4) the post-collisional A-type granite dykes, which are exposed along strike-slip faults, have ages between 282.5 and 279.2Ma, ɛHf(t) values from + 4.8 to + 12.6, and Hf model ages between 436 and 729 Ma; 5) the A-type biotite granite dykes that intruded along conjugate tension joints have ages between 273.9 and 271.4 Ma, ɛHf(t) values from + 1.1 to + 12.8, and Hf model ages between 393 and 979 Ma. In

  18. African women, literature, language and culture

    OpenAIRE

    Rosamond S. King

    2014-01-01

    This essay will link African women’s writing to culture, including literary culture and the politics of literature. It describes how African women’s literature can act as a mirror, reflecting African cultures to Africans, and how it can serve as a window and a door, revealing African cultures to those outside of them in whole or in part. It ends with a description of “communal agency,” an example of how scholarly writing can act as a door for both those who are and are not a part of a literat...

  19. Origins, consolidation and challenges of African Hispanism

    Directory of Open Access Journals (Sweden)

    Vital Tama Bena

    2014-08-01

    Full Text Available The African continent today takes into consideration a cultural movement which can be called African Hispanism. Born with the beginning of the post-colonial era, this African Hispanism has witnessed a progressive setting up in African countries thanks to the impetus of teachers of the Spanish language. Today that action benefits from a notorious cultural life as observed trough Spanish users of that language on the one hand; on the other hand the birth of a very promising African Spanish literature. Yet some future challenges are to come for a real fruitful future of that cultural movement. Key words: Spanish language; Africa intercultural exchanges.

  20. Tool Belts: Latitudinal-Belt Predictions for the Persistence of Landscapes

    Science.gov (United States)

    Willenbring, Jane; Brocard, Gilles

    2016-04-01

    The ability of rivers to cut through rock and re-establish equilibrium sets the pace of landscape response to uplift. Because of associations between tectonics, erosion, and weathering, high rates of rock uplift may initiate a cascade of processes that are linked to high rates of weathering and eventually sequestration of CO2 over geologic timescales. How long does it take to completely change the topographic form after uplift and where on Earth do relict landscapes persist despite uplift? Large expanses of subdued landscapes are common at high elevation in mountain ranges. Preservation of subdued fragments amongst steeply dissected regions can therefore be a simple matter of chance, reflecting the time it takes for dissection to remove any remaining parcel of the pre-existing topography after a tectonic perturbation. Some of these relicts may, however, possess characteristics - often a product of the climate - that make them intrinsically resistant to dissection. One common mode of conversion of a subdued landscape into a deeply dissected one is the propagation of upstream-migrating erosion waves that transmit the signal of uplift and base level lowering across entire landscapes. Following a shift in tectonic forcing, the Earth's surface progressively adjusts its topographic form over millions of years, seeking to re-establish equilibrium with the new forcing. Here, we show that a high degree of weathering leading to smaller average soil grains at the surface hinders the capacity of rivers to incise. We show that globally, rates of cosmogenic nuclide-derived denudation rates fall into latitudinal belts with (1) low rates of denudation in areas with high temperatures and high precipitation where rock fragments do not persist at the soil surface, (2) high rates of denudation at mid-latitudes where rock fragments exist and are carried efficiently by the river flow, and (3) low rates of denudation at high latitudes where large grains at the surface inhibit channelized

  1. Evolution of an intra-oceanic island arc during the late Silurian to late Devonian, New England fold belt

    International Nuclear Information System (INIS)

    Geochemical studies of volcanic rocks in the Gamilaroi terrane and Calliope Volcanic Assemblage, New England Fold Belt, eastern Australia, indicate that the setting in which these rocks formed changed in both space and time. The Upper Silurian to Middle Devonian basalts of the Gamilaroi terrane show flat to slightly light rare-earth element (LREE) depleted chondrite normalised patterns, depletion of high field strength elements (HFSE) relative to N-MORB, low Ti/V and high Ti/Zr ratios, high Ni, Cr and large-ion lithophile element (LILE) contents, features characteristic of intra-oceanic island arc basaltic magmas. They are associated with low-K, less mafic volcanics, showing moderate LREE enrichment, low Nb and Y contents and Rb/Zr ratios. The depletion of HFSE in the basalts indicates that the magmas were derived from a refractory source in a supra-subduction zone setting. The presence of such a zone implies that the arc was associated with a backarc basin, the location of which was to the west where a wide backarc region existed from the Middle Silurian. This polarity of arc and backarc basin suggests that the subduction zone dipped to the west. In contrast to their older counterparts, Middle to Upper Devonian basalts of the Gamilaroi terrane have MORB-like chondrite normalised patterns and higher Ti and lower LILE contents. Moreover, they have low Ti/Zr ratios and MORB-like Ti/V ratios and HFSE contents, features typical of backarc basins. Dolerites of the Gamilaroi terrane also have predominantly backarc basin signatures. These features suggest that both the basalts and dolerites have been emplaced in an extensional environment produced during the rifting of the intra-oceanic island arc lithosphere. A progressive increase in Ti/V ratios, and TiO2 and Fe2O3 contents at constant MgO, of stratigraphically equivalent basalts, towards the north-northwest part of the belt, is consistent with either greater extension to the north or melting of a more fertile magma

  2. Improvisation in West African Musics.

    Science.gov (United States)

    Locke, David

    1980-01-01

    Discussed is music of the sub-Sahara. Vocal, instrumental, and dance drumming from the Sudan Desert, the North Coast, East Horn, Central and West Africa, and contrapuntal yodeling of Pygmies is described. For African musicians, the ability to improvise, and creativity, are gifts from God. Includes selected readings and recordings. (KC)

  3. Vitamin D and African Americans

    Science.gov (United States)

    Vitamin D insufficiency is more prevalent among African Americans than other Americans and, in North America, most young, healthy blacks do not achieve optimal 25-hydroxyvitamin D [25(OH)D] concentrations at any time of the year. This is primarily due to the fact that pigmentation reduces vitamin D...

  4. Classic African American Children's Literature

    Science.gov (United States)

    McNair, Jonda C.

    2010-01-01

    The purpose of this article is to assert that there are classic African American children's books and to identify a sampling of them. The author presents multiple definitions of the term classic based on the responses of children's literature experts and relevant scholarship. Next, the manner in which data were collected and analyzed in regard to…

  5. Quo vadis South African universities?

    OpenAIRE

    Johann RE lutjeharms

    2007-01-01

    The Economist has recently identified some specific factors that explain why European universities are not competing adequately with their American counterparts. These factors are used here to evaluate South African government policy for universities. It is demonstrated that this current policy is directly contrary to what is now internationally considered best for universities in a knowledge economy.

  6. Crustal shortening in the Palmyride Fold Belt, Syria, and implications for movement along the Dead Sea Fault System

    Science.gov (United States)

    Chaimov, Thomas A.; Barazangi, Muawia; Al-Saad, Damen; Sawaf, Tarif; Gebran, Ali

    1990-12-01

    The Palmyride fold belt is a northeast-trending, 400 by 100 km transpressive belt in central Syria embedded in the northern Arabian platform, bounded to the north by the Aleppo plateau and to the south by the Rutbah uplift. Palinspastically restored cross sections from three transects across the Palmyride fold belt demonstrate a minimum NW-SE shortening of about 20% or 20 km across the southwestern segment of the belt, diminishing to 1-2 km in the northeast, close to the Euphrates graben system. The cross sections are based on the 1∶200,000 scale geologic map of Syria and previously unavailable seismic reflection and well data, all provided by the Syrian Petroleum Company. These results differ significantly from those predicted by kinematic models of Middle East plate motions. In western Syria and eastern Lebanon the Palmyrides obliquely intersect (at about 45°) the roughly north-trending Dead Sea transform fault system. The Dead Sea fault system shows well-documented evidence of 105 km of left-lateral displacement since mid-Tertiary time south of its intersection with the Palmyrides, yet only about 25 km of motion has been documented north of that juncture in Lebanon and western Syria. Thus, kinematic models of Middle East plate motions predict 80 km of shortening in Syria, most of which should be accommodated in the Palmyride fold belt. Several possibilities exist to explain the discrepancy between the 80 km of predicted shortening and the only 20 km of shortening measured from restored cross sections. Restored cross sections offer only minimum shortening estimates, so the calculated 20 km may underestimate shortening. Second, evidence of strike-slip displacement recognized in minimum shortening estimates, so the calculated 20 km may underestimate shortening. Second, evidence of strike-slip displacement recognized in the field and reported in the literature, and indicated by new focal mechanism solutions of two recent earthquakes in the Palmyrides, indicates

  7. Structure of the Asteroid Belt from the Gas Giants' Growth and Chaotic Dynamics

    Science.gov (United States)

    Izidoro, André; Raymond, Sean N.; Pierens, Arnaud; Morbidelli, Alessandro; Winter, Othon; Nesvorny, David

    2016-05-01

    The structure of the asteroid belt holds a record of the Solar System's dynamical history. The current belt only contains 10-3 Earth masses yet the asteroids' orbits are dynamically excited, with a large spread in eccentricity and inclination. The belt is also chemically segregated: the inner belt is dominated by dry S-types and the outer belt by hydrated C-types. Here we propose a new model in which the asteroid belt was always low-mass and was partially populated and sculpted by the giant planets on chaotic, resonant orbits. We first show that the compositional dichotomy of the asteroid belt is a simple consequence of Jupiter's growth in the gaseous protoplanetary disk. As Jupiter's core rapidly grew by accreting gas, orbits of nearby planetesimals were perturbed onto Jupiter-crossing trajectories. A significant fraction (~10%) of objects in the neighborhood exterior of Jupiter's orbit were implanted by gas drag into the outer parts of the asteroid belt as C-types. While the gas giants were likely in mean motion resonance at the end of the gaseous disk phase, we show that small perturbations may have driven them into a chaotic but stable state. After the dissipation of the gaseous disk, stochastic variations in the gas giants orbits caused resonances to chaotically jump across the main belt and excite the asteroids' orbits. Our results suggest that the early Solar System was chaotic and introduce a simple framework to understand the origins of the asteroid belt.

  8. Origin of hominids: European or African origin, neither or both?

    Directory of Open Access Journals (Sweden)

    Senut, B.

    2011-12-01

    Full Text Available For the last twenty years, some scientists have suggested that the African ape and humans lineages emerged in Europe, a scenario known as the “Back to Africa Hypothesis”. Even though hominoids were widespread in Eurasia during the Middle and Upper Miocene due to the tropical conditions which prevailed in this region, we cannot dismiss the fact that they were present in Africa (contra some authors. Actually, they were highly diverse at that same time (at least 10 lineages represented even if the fossil record is less complete than in Eurasia. Postcranial elements from African species suggest that some features of modern hominoids were already present in the Lower and Middle Miocene of Africa and were not restricted to European ones. Considering the available evidence, it is not possible at this stage to favour a European origin over an African one. Hominoids were living in the tropical areas of Northern Africa and Southern Eurasia and faunal exchanges between the two continents occurred throughout the Middle and Upper Miocene, as the Tethys did not act as an effective barrier to interchanges between Europe and Asia.

    Durante los últimos veinte años, algunos científicos han sugerido que los grandes monos africanos y los linajes humanos surgieron en Europa, un escenario conocido como la “ Hipótesis de la vuelta a Africa”. A pesar de que los homínidos se extendieron en Eurasia durante el Mioceno Medio y Superior debido a las condiciones tropicales que prevalecian en esta region, no podemos descartar el hecho de que ellos estuvieron presentes en Africa (contra algunos autores. En realidad, ellos tuvieron una alta diversidad al mismo tiempo (al menos 10 líneas representadas, incluso si el registro fosil es menos completo que el de Eurasia. Elementos postcraneales de especies africanas sugieren que en algunos carácteres los homínidos modernos estaban ya presentes en el Mioceno Inferior y Medio de Africa, no sólo restringidos a

  9. The constraints of strain partitioning and geochronology in Luonan-Luanchuan tectonic belts on Qinling orogenic belt

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Luonan-Luanchuan tectonic belt lies between the North China Block and Qinling Mountains, in- cluding the Luonan-Luanchuan fault zone and the strong deformation zone to the north of the fault. The ductile shear zone, imbricate brittle fault and duplex structure in the fault zone now are the expression of the same tectonic event in different depth. Such lineation structure exists in the tectonic belts as mineral lineation, elongation lineation, crenulation lineation, sheath folds and so on, indicating NE-directed plate motion. Fold axes and thrusts in the strong deformation zone are inclined to the Luonan-Luanchuan fault zone at small angles. The structures with different natures show a regular pattern, produced during oblique convergence of plates. The convergence factors are as follows:The direction of plate convergence is 22°, 31° and the angle between the plate convergence direction and plate boundary is 73°, 82° respectively in the west and east segment. The Luonan-Luanchuan tectonic belt was deformed strongly in 372 Ma, resulted from Erlangping back-arc ocean basin subduction sin- istrally and obliquely to North China Block during the collision of North China Block and South China Block.

  10. The constraints of strain partitioning and geochronology in Luonan-Luanchuan tectonic belts on Qinling orogenic belt

    Institute of Scientific and Technical Information of China (English)

    SONG ChuanZhong; ZHANG GuoWei; WANG YongSheng; LI JiaHao; CHEN ZeChao; CAI ZhiChuan

    2009-01-01

    The Luonan-Luanchuan tectonic belt lies between the North China Block and Qinling Mountains,including the Luonan-Luanchuan fault zone and the strong deformation zone to the north of the fault.The ductile shear zone,imbricate brittle fault and duplex structure in the fault zone now are the expression of the same tectonic event in different depth.Such lineation structure exists in the tectonic belts as mineral lineation,elongation lineation,crenulation lineation,sheath folds and so on,indicating NE-directed plate motion.Fold axes and thrusts in the strong deformation zone are inclined to the Luonan-Luanchuan fault zone at small angles.The structures with different natures show a regular pattern,produced during oblique convergence of plates.The convergence factors are as follows:The direction of plate convergence is 22°,31° and the angle between the plate convergence direction and plate boundary is 73°,82° respectively in the west and east segment.The Luonan-Luanchuan tectonic belt was deformed strongly in 372 Ma,resulted from Erlangping back-arc ocean basin subduction sinistrally and obliquely to North China Block during the collision of North China Block and South China Block.

  11. Contact and hybrid zone hotspots and evolution of birds in the Middle East

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Middle East is an important contact zone for a considerable number of bird taxa from the western and eastern Palearctic and from the great Saharo-Sindian jesert belt. Using WORLDMAP software, we analyzed the geographical distribution of secondary contact zones for parapatric species pairs of birds in the Middle East. We identified 56 species (29 species pairs) that make contact in the Middle East. The species pairs belong to three orders, i.e. Falconiformes, Piciformes, and Passeriformes. Almost half (46%) of these species pairs hybridize in their contact zones. Although contact zones occur over a large part of northern Middle East, spatially they were not evenly distributed. Contact zone richness was highest in the mountain ranges south of the Caspian Sea and the Caucasus. The hottest hotspots, where up to nine bird species pairs occur sympatrically, are situated in north-eastern Iran and Azerbaijan. We discuss the relevance of these hotspots for improving our understanding of the biogeography and evolution of the avifauna in the Middle East.

  12. Appropriateness of no-fault compensation for research-related injuries from an African perspective: an appeal for action by African countries.

    Science.gov (United States)

    Kamalo, Patrick Dongosolo; Manda-Taylor, Lucinda; Rennie, Stuart

    2016-08-01

    Compensation for research-related injuries (RRIs) remains a challenge in the current environment of global collaborative biomedical research as exemplified by the continued reluctance of the US government, a major player in international biomedical research, to enact regulation for mandatory compensation for RRIs. This stance is in stark contrast to the mandatory compensation policies adopted by other democracies like the European Union (EU) countries. These positions taken by the USA and the EU create a nexus of confusion when research is exported to low-income and middle-income countries which have no laws guiding compensation for RRIs. In this paper, we begin by exploring the background to policies concerning RRIs, how they reflect on the traditional dispute resolution mechanisms in African societies, and how this compares with the no-fault compensation model. We then explore the underlying African ethical framework of Ubuntu in the sub-Saharan region, guiding traditional practices of dispute resolution and compensation, and how this framework can help to form the moral justification for no-fault compensation as the preferred compensation model for RRIs for African countries. Finally, we call upon countries in the African Union (AU), to adopt a no-fault policy for compensation of RRIs, and enact it into a regulatory requirement for insurance-based no-fault compensation for biomedical research, which will then be enforced by member states of the AU. PMID:27259545

  13. Sm/Nd data of metasedimentary rocks from the central segment of Ribeira Belt, southeastern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ragatky, Diana; Tupinamba, Miguel; Duarte, Beatriz Paschoal [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Faculdade de Geologia. Grupo de Pesquisa Geotectonica - Tektos

    2000-03-01

    The central segment of Ribeira Belt, southeastern brazil, comprises several tectonic domains where, during the Proterozoic, extensive detritic material was deposited over pre-1.8 Ga basement rocks. This paper presents Sm-Nd isotopic data on the high-grade metasedimentary rocks of this belt and discusses some possible implications on their sedimentary provenance. The pre-1.8 Ga basement rocks display different Nd isotopic evolution and thus can be promptly discriminated as sources of different Nd model ages (T{sub DM}) and isotopic characteristics such as: Mantiqueira such as: Mantiqueira Complex, 3.0 and 2.6 Ga T{sub DM} isochrons ages; Juiz de Fora Complex, 2.2 Ga T{sub DM} isochron age and Quirino Complex, 2.0 Ga and 3.2 Ga T{sub DM} ages. At the Juiz de Fora Domain, metapelites from the Andrelandia Depositional Cycle display a very narrow range of Sm/Nd values (0.15 to 0.17) and T{sub DM} ages between 1.8 and 2.0 Ga. The corresponding measured {epsilon}{sub Nd} values [{epsilon}{sub Nd} (0)] vary between -20.8 and -29.1. The metapsammopelites of the Jardim Gloria Unit, in the same geologic domain, display very different isotopic characteristics: higher Sm/Nd ratios (0.22 and 0.24), lower {epsilon}{sub Nd} (0) values (-15.3 and -18.3) and Neoarchean T{sub DM} ages (2.5 and 2.6 Ga). At the Paraiba do Sul Klippe, the analyzed metapelites from the middle unit of Paraiba do Sul group show T{sub DM} ages close to 1.7 Ga with e{sub ND} (0) values of -14.10 and -17.34. The metapsammopelites from the basal and uppermost units plot the 2.0 Ga T{sub DM} isochron and display {epsilon}{sub Nd} (0) values vary between-21 and -32. An isolated T{sub DM} of an amphibolitic body, probably intrusive in the metasedimentary rocks of Paraiba do Sul Group, yields 1.0 Ga T{sub DM} age, with a {sup 147} Sm/{sup 144} Nd value of 0.1428. (author)

  14. Sm/Nd data of metasedimentary rocks from the central segment of Ribeira Belt, southeastern Brazil

    International Nuclear Information System (INIS)

    The central segment of Ribeira Belt, southeastern brazil, comprises several tectonic domains where, during the Proterozoic, extensive detritic material was deposited over pre-1.8 Ga basement rocks. This paper presents Sm-Nd isotopic data on the high-grade metasedimentary rocks of this belt and discusses some possible implications on their sedimentary provenance. The pre-1.8 Ga basement rocks display different Nd isotopic evolution and thus can be promptly discriminated as sources of different Nd model ages (TDM) and isotopic characteristics such as: Mantiqueira such as: Mantiqueira Complex, 3.0 and 2.6 Ga TDM isochrons ages; Juiz de Fora Complex, 2.2 Ga TDM isochron age and Quirino Complex, 2.0 Ga and 3.2 Ga TDM ages. At the Juiz de Fora Domain, metapelites from the Andrelandia Depositional Cycle display a very narrow range of Sm/Nd values (0.15 to 0.17) and TDM ages between 1.8 and 2.0 Ga. The corresponding measured εNd values [εNd (0)] vary between -20.8 and -29.1. The metapsammopelites of the Jardim Gloria Unit, in the same geologic domain, display very different isotopic characteristics: higher Sm/Nd ratios (0.22 and 0.24), lower εNd (0) values (-15.3 and -18.3) and Neoarchean TDM ages (2.5 and 2.6 Ga). At the Paraiba do Sul Klippe, the analyzed metapelites from the middle unit of Paraiba do Sul group show TDM ages close to 1.7 Ga with eND (0) values of -14.10 and -17.34. The metapsammopelites from the basal and uppermost units plot the 2.0 Ga TDM isochron and display εNd (0) values vary between-21 and -32. An isolated TDM of an amphibolitic body, probably intrusive in the metasedimentary rocks of Paraiba do Sul Group, yields 1.0 Ga TDM age, with a 147 Sm/144 Nd value of 0.1428. (author)

  15. Tectonomorphic evolution of the Eastern Cordillera fold-thrust belt, Colombia: New insights based on apatite and zircon (U-Th)/He thermochronometers

    Science.gov (United States)

    Ghorbal, B.; Stockli, D. F.; Mora, A.; Horton, B. K.; Blanco, V.; Sanchez, N.

    2010-12-01

    The Eastern Cordillera (EC) of Colombia marks the eastern boundary of Cenozoic fold-thrust deformation in the northern Andes. It is a classic example of an inversion belt formed in the retro-arc region, in this case superimposed on a Triassic/Jurassic to Cretaceous intracontinental rift system of northern South America. Ongoing thrust reactivation (inversion) in this contractional orogen provides an excellent opportunity to study the patterns of deformation and influence of preexisting anisotropies (Mora et al., 2006). The objective of this detailed (U-Th)/He study is to unravel the tectonic and thermal evolution of the EC from the Magdalena Valley basin in the west to the Llanos foreland basin in the east and reconstruct the temporal and spatial progression of deformation in the EC fold-thrust belt. Furthermore, the Subandean or foothills zone of Colombia is key for understanding the petroleum systems in the complex frontal zone of the inverted fold-thrust belt. We present detailed apatite and zircon (U-Th)/He thermochronometric data from surface samples along a ~220 km WNW-ESE transect across the EC from the frontal fold-thrust belt at the edge of the Llanos basin to the western edge of the EC, the Magdalena basin. Surface and borehole zircon and apatite (U-Th)/He data, integrated with structural data, show that the EC fold-thrust belt propagated foreland-ward from the axial zone to the modern edges of the fold-thrust belt from at least the early Oligocene to the early Miocene. Detailed apatite and zircon (U-Th)/He data from surface samples and borehole samples in the foothills-Llanos transition zone and the Middle Magdalena Valley basin, between the large-displacement Guaicaramo and Pajarito-Chámeza thrusts in the east and the La Salina fault system in the west show a temporally complex evolution. The frontal fold-thrust belt was characterized by continued progressive foreland-ward migration of deformation and an apparent phase of major out-of-sequence motion

  16. The prevalence of seat belt use in Jamaica. An observational study.

    Science.gov (United States)

    Crandon, I W; Branday, J M; Simeon, D T; Rhoden, A; Thompson, H; Carpenter, R

    1996-03-01

    An observational cross-sectional survey showed that 21.1% of private motor vehicle drivers and 13.5% of front seat passengers voluntarily wore seat belts in Kingston, Jamaica, where there is no law requiring this. Rear passenger utilisation was not examined. Compared to males, females were significantly more likely to wear seat belts when driving but not as front seat passengers. Of all motor vehicles examined, 10.1% were not equipped with seat belts. The oldest group of vehicles were mostly not fitted with seat belts. Drivers of older vehicles were significantly less likely to use seat belts even when the vehicles were equipped with belts. Implementation of legislation can reduce mortality, morbidity and costs from road traffic accidents which are relatively frequent in Jamaica. Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign should legislation, which is highly desirable, be implemented.

  17. African-American males in computer science---Examining the pipeline for clogs

    Science.gov (United States)

    Stone, Daryl Bryant

    " self-efficacy between lower-level computer science majors and upper-level computer science majors. (5) There is no significant difference in "Computer Science Degree" self-efficacy between each of the five groups of students. Finally, the researcher selected African-American male students attending six primary schools, including the predominately African-American elementary, middle and high school that the researcher attended during his own academic career. Additionally, a racially mixed elementary, middle and high school was selected from the same county in Maryland. Bowie State University provided both the underclass and upperclass computer science majors surveyed in this study. Of the five hypotheses, the sample provided enough evidence to support the claim that there are significant differences in the "Computer Science Degree" self-efficacy between each of the five groups of students. ANOVA analysis by question and total self-efficacy scores provided more results of statistical significance. Additionally, factor analysis and review of the qualitative data provide more insightful results. Overall, the data suggest 'a clog' may exist in the middle school level and students attending racially mixed schools were more confident in their computer, math and science skills. African-American males admit to spending lots of time on social networking websites and emailing, but are 'dis-aware' of the skills and knowledge needed to study in the computing disciplines. The majority of the subjects knew little, if any, AAMs in the 'computing discipline pipeline'. The collegian African-American males, in this study, agree that computer programming is a difficult area and serves as a 'major clog in the pipeline'.

  18. Frozen subduction in the Yangtze block: insights from the deep seismic profiling and gravity anomaly in east Sichuan fold belt

    Science.gov (United States)

    Xiong, Xiaosong; Gao, Rui; Wang, Haiyan; Zhang, Jisheng; Guo, Lianghui

    2016-04-01

    The Sichuan basin is the main part of the middle-upper Yangtze block, which has been experienced a long-term tectonic evolution since Archean. The Yangtze block was regarded as a stable block until the collision with the Cathaysia block in late Neoproterozoic. A new deep seismic reflection profile conducted in the eastern Sichuan fold belt (ESFB) discovered a serials of south-dipping reflectors shown from lower crust to the mantle imply a frozen subduction zone within the Yangtze block. In order to prove the speculation, we also obtain the middle-lower crustal gravity anomalies by removing the gravity anomalies induced by the sedimentary rocks and the mantle beneath the Moho, which shows the mid-lower crustal structure of the Sichuan basin can be divided into eastern and western parts. Combined with the geochronology and Aeromagnetic anomalies, we speculated the Yangtze block was amalgamated by the West Sichuan and East Sichuan blocks separated by the Huayin-Chongqing line. The frozen subduction zone subsequently shifted to a shear zone accommodated the lower crustal shortening when the decollement at the base of the Nanhua system functioned in the upper plate.

  19. Distribution and Numbers of Pygmies in Central African Forests.

    Directory of Open Access Journals (Sweden)

    Jesús Olivero

    Full Text Available Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654 in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples' culture and lifestyles.

  20. [Human African trypanosomiasis in an urban area: an emerging problem?].

    Science.gov (United States)

    Louis, F J; Bilenge, C M; Simarro, P P; Meso, V Kande; Lucas, P; Jannin, J

    2003-08-01

    The human African trypanosomiasis is essentially a rural disease. The notification of cases in urban area has always been incidental; either a diagnosis made in town revealed a disease contracted in rural environment or it meant the preservation of a complete epidemiological cycle in a remaining urban micro-focus. In Kinshasa, in Democratic Republic of Congo, about forty cases have been notified each year. All of them came from the nearby foci of Bandundu, Lower Congo and Kasaï. In 1996 the number of cases reached suddenly 254 and today the average annual number comes up to 500 in spite of all the efforts undertaken to fight the disease. A study of cases in 1998 and 1999 shows that patients are essentially distributed in suburbs and that the most affected by the disease are the 15-49 year old ones whose job is related with agricultural or fishing activities. Two phenomena seem to explain this sudden increase: the massive inflow of refugees in outskirts of town coming from provinces where trypanosomiasis is endemic and a major economic crisis throwing out urban population in suburbs living on a subsistence micro-agriculture. These concomitant factors have contributed to the setting up of a trypanosomiasis belt around the capital. Today a strategy has to be reconsidered in order to fight against the disease in the capital itself and to make the medical staff aware of the diagnosis of a disease still unknown in their sanitary district.

  1. Distribution and Numbers of Pygmies in Central African Forests.

    Science.gov (United States)

    Olivero, Jesús; Fa, John E; Farfán, Miguel A; Lewis, Jerome; Hewlett, Barry; Breuer, Thomas; Carpaneto, Giuseppe M; Fernández, María; Germi, Francesco; Hattori, Shiho; Head, Josephine; Ichikawa, Mitsuo; Kitanaishi, Koichi; Knights, Jessica; Matsuura, Naoki; Migliano, Andrea; Nese, Barbara; Noss, Andrew; Ekoumou, Dieudonné Ongbwa; Paulin, Pascale; Real, Raimundo; Riddell, Mike; Stevenson, Edward G J; Toda, Mikako; Vargas, J Mario; Yasuoka, Hirokazu; Nasi, Robert

    2016-01-01

    Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples' culture and lifestyles.

  2. A Middle Permian-Middle Triassic accretionary complex and a Late Triassic foredeep basin: Forerunners of an Indosinian (Late Triassic) thrust complex in the Thailand-Malaysia border area

    Science.gov (United States)

    Ridd, Michael F.

    2013-10-01

    The Semanggol Formation of NW Peninsular Malaysia is a Middle Permian-Late Triassic sequence of predominantly radiolarian chert, sandstone and mudstone (including turbidites), and conglomerate. The belt of country occupied by this unit extends into Thailand where various names including Na Thawi formation have been applied to its correlatives. Fossil evidence, particularly radiolarian, has established its age but also revealed that it is tectonically complex, with numerous out-of-sequence slices interpreted here to be caused by thrusting. The model proposed here involves, initially, in the Middle Permian, accumulation in the oceanward part of an accretionary complex as Palaeotethys began subducting beneath Indochina/East Malaya. This regime, it is proposed, continued until about the end of the Middle Triassic when Sibumasu collided with Indochina/East Malaya bringing an end to subduction. But as crustal shortening continued into the Late Triassic a foredeep basin formed in front of the now-inactive subduction zone and accretionary complex, and the youngest part of the Semanggol Formation was deposited. During this final stage the whole package of rocks comprising those in the accretionary complex and those deposited in the foredeep basin underwent lateral compression resulting in a thrust complex. The Semanggol Formation and its Thailand correlatives occupy part of a N-S belt of imbricately-thrust, deeper-water, sediments which include slope-deposited Carboniferous and Lower Permian beds. That belt is interpreted as a series of thrust slices juxtaposing rocks of different ages, referred to here as the Songkhla-Semanggol terrane. Its western boundary is a N-S line of inferred thrusting which coincides with a major westward facies change to platform carbonates of Middle Permian to Late Triassic age, called here the Rattaphum-Kodiang tectonic line.

  3. LATOZOIC-SOILS GEOARCHAEOLOGICAL BELT AND EARLY MAN EVOLUTION%红土地质考古带和早期人类进化

    Institute of Scientific and Technical Information of China (English)

    黄慰文

    2000-01-01

    分布在旧大陆热带、亚热带的红土是一条巨型纬向地质体、它汇集了迄今已知年代 最古老的人类化石和旧石器遗址,是研究人类起源、人类最初扩散以及同时期全球环境变迁的信息载体。近年亚洲红土地质考古带的重大发现表明,亚洲、非洲最早出现的人类在年代上、体质特征上和文化面貌上都十分接近。这个事实将对人类演化理论产生重大影响。%Corresponding to the loessic geoarchaeological belt which covers the global surfaceof the temperate zone, the latozoic-soils geoarchaeological belt is also a tremendousgeological object which covers the global surface of tropics and subtropics. Theevidence of the known earliest human occupations in the Old World is veryconcentrated on this belt. Therefore, much more attention should be given to it tounderstand the most basic questions for the human evolution such as follows: whendid humankind emerge on the earth? where is the homeland of humankind? who was the first species of the Genus Homo? and why did they leave their homeland andbegan the first dispersals to other regions? People thought usually these questions based themselves upon African origin, a kindof the unilineal hypothesis. However, the recent advances in the research of Paleolithicarchaeology and paleoanthropology from the Asian latozoic-soils geoarchaeological beltgive a strong challenge to these traditional sences. The important advances include: (1) the new dating of Peming skull(H. erectus) from Java, 1.81MaB. P. based onAr-Ar dating, and Yuanmou teeth (H. erectus) from southwestern China, 1.60~1.10MaB. P. based on ESR dating; (2) the mandible and incisor from Longgupo cave site of southem China, whichmay be compared with H. habilis or H. ergaster from Africa, and the stone industrywhich is similar to the characteristics of the earliest African stone industries, 2.0MaB. P.based on ESR dating; (3) the stone and bone artifacts associated with

  4. Experimental Study of Kinetic Properties of Pyrolysis for Conveyor Belt in Coal Mine

    Institute of Scientific and Technical Information of China (English)

    SONG Zheng-chang

    2005-01-01

    The combustion of conveyor belt is a leading factor of mine fire. In this paper, the pyrolysis properties of ordinary conveyor belt and fire-resistant belt were studied experimentally with thermo-gravimetric analysis and derivative thermo-gravimetric analysis, and the curves of pyrolysis properties were achieved. On this basis, the activation energy and reaction order of pyrolysis were obtained in combination with theoretical analysis, aiming to provide data for further numerical simulation and simulating experiment of mine fire.

  5. Data From HANE-Generated Radiation Belts and the Origin of Diffusion Theory

    Energy Technology Data Exchange (ETDEWEB)

    Winske, Dan [Los Alamos National Laboratory

    2012-07-16

    In this presentation we briefly review some of the published data regarding the artificial radiation belts produced by the Starfish and R2 high altitude nuclear explosions in 1962. The data showed slow temporal variations of the belts in altitude (L) and pitch angle ({alpha}) that could be modeled as a diffusion process. That early work formed the basis for more complex radiation belt diffusion models that are in use at present.

  6. The "One Belt and One Road" is an Important Mutually Beneficial and Win-win Strategy

    Institute of Scientific and Technical Information of China (English)

    Long; Kaifeng

    2015-01-01

    The"One Belt and One Road"strategic conception carries the dream of development and prosperity of countries concerned,and gives the ancient Silk Road a brand new content of the time.In September and October 2013,President Xi Jinping proposed building the"New Silk Road Economic Belt"(One Belt)and the"Twenty-first Century Maritime Silk Road"(One Road)strategic conception respectively,emphasizing a mutual-beneficial and win-win

  7. Progress in porphyry copper exploration from the Gangdise belt, Tibet, China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Youye; DUO Ji; CHENG Shunbo; GAO Shunbao; DAI Fanghua

    2007-01-01

    Recent mineral exploration in the Gangdise porphyry copper deposit belt, an important component of the Himalaya-Tethyan metallogenic belt, has led to the discovery of a number of deposits, as exemplified by the world-class Miocene Qulong porphyry Cu deposit. This paper reviews major advances in the studies of ore genesis and metallogenic regularity and progresses in mineral exploration of porphyry Cu deposits in the belt. Existing problems and suggestion for future exploration also are given.

  8. PROSPECTS OF TRANSPORT INFRASTRUCTURE DEVELOPMENT BETWEEN THE MIDDLE EAST COUNTRIES AND CHINA

    Directory of Open Access Journals (Sweden)

    Ms. Zanna V. Petrunina

    2016-09-01

    Full Text Available Policy management of modern China aims to achieve a high level of welfare state. One of the important components that contributes to the achievement of this goal is the expansion of China's cooperation with the Middle East countries in all fields. At present, China is interested in obtaining energy from the Middle East oil fields. Of great importance is the transport infrastructure expansion between the regions. Construction and operation of oil pipelines, gas pipelines and land transport routes will reduce the risks of transporting raw materials and other goods from one region to another. The paper discusses the features of the development of rail and sea links as part of the strategy of «economic belt of the Silk Road» and «Marine Silk Road of XXI century».

  9. «Granulite» zircons of the Lapland granulite belt

    Science.gov (United States)

    Kaulina, T.

    2003-04-01

    An age of the main stage of granulite metamorphism, which followed the overthrusting of the Lapland granulite belt (LGB) is estimated at about 1.91-1.95 Ga (Tugarinov, Bibikova, 1980; Bernard-Griffiths et al., 1984; Bibikova et al., 1993; Mitrofanov et al., 1993). This high-grade metamorphism is dated by U-Pb method on short prismatic gem-quality zircons that are typical for granulites and are interpreted as formed under stress and space-shortage conditions of the high pressure. And the common belief is that these zircon ages are dating the peak conditions of a metamorphic P-T path, since zircon has a high closure temperature of its U-Pb system. We studied rocks with different degree of metamorphism from Yavr and Pados rivers district (Kola Peninsula, Russia) located in the connection zone of the Tanaelv belt and LGB. Samples from the Tanaelv belt were taken from: 1) leucocratic garnet-clinopyroxene-amphibole plagiogneiss, chemically corresponds to andesite and formed under amphibolite facies 2) leucocratic biotite-pyroxene plagiogneiss with mineral association of granulite facies. Lapland granulites are represented by sillimanite-garnet-biotite gneiss from khondalite complex and leuco-mesocratic amphibole-pyroxene-plagioschist, belonging to the charnockite complex. Metamorphic zircons in all studied samples are represented practically by crystals of the same image. These are round or isometric (rarely subidiomorphic-prismatic in mafic granulites) large crystals with bright luster and high transparency. They are colorless or weakly colored into yellowish-pinkish tones. Crystals are zoneless but may contain cores, especially zircons from khondalite, 60% of which contain zoned cores. Thus typically “granulitic” zircon, described in many works, is the dominant type both in granulites of the Lapland belt and in amphiboles gneisses of the Tanaelv belt. Zircons are distinguished by low U contents (up to 100 ppm) and high Th/U and Zr/Hf ratios (0.6-0.7 and 42

  10. The Migration Characteristics of Strong Earthquakes on the North-South Seismic Belt and Its Relation with the South Asia Seismic Belt

    Institute of Scientific and Technical Information of China (English)

    Wang Yipeng; Ma Jin; Li Chuanyou

    2008-01-01

    Migration of strong earthquakes (M≥7.0) along the North-South Seismic Belt of China since 1500 AD shows three patterns: Approximately equal time and distance interval migration from N to S, varied patterns of migration from S to N and grouped strong earthquake activity in a certain period over the entire seismic belt. Analysis of strong earthquakes in the past hundred years shows that the seismicity on the North-South Seismic Belt is also associated with strong earthquake activities on the South Asia Seismic Belt which extends from Myanmar to Sumatra, Indonesia. Strong earthquakes on the former belt often lag several months or years behind the quakes occurring on the later belt. So, after the occurrence of the December 26, 2004 M8.7 great earthquake off the western coast of Sumatra, Indonesia, the possibility of occurrence of strong earthquakes on the North-South Seismic Belt of China cannot be ignored. The above-mentioned migration characteristics of strong earthquakes are related to the northeastward collision and subduction of the India Plate as well as the interaction between the Qinghai-Xizang (Tibet) Plateau and the stable and hard Ordos and Alashan Massifs at its northeastern margin.

  11. Geological characteristics and metallogenic prognosis of main gold deposit in Altai gold ore belt, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    SHEN Yuan-chao; SHEN Ping; ZHENG Qing-dong; LIU Tie-bing; LI Guang-ming

    2004-01-01

    Altai polymetallic mineralization belt is famous copper-polymetallic mineralization belt in the world. There are a lot of gold deposits in the Altai ore belt in Xinjiang, China. These gold deposits belong to two genetic types: volcanogene late-stage hydrothermal type and fractured altered rock type. The authors discuss mainly the geological and mineralized features of fractured altered rock type of gold deposits in Altai gold ore belt. Base on this study, the metallogenic law is summarized and the deep metallogenic prognosis has been done in Duolanasayi and Tuokuzibayi gold deposits, and some mineralized anomalys have been discovered.

  12. Crafts in the Middle Years

    Science.gov (United States)

    Porter, D. I. R.

    1972-01-01

    In the middle years of schooling, size, measurement, shape and form build up a child's mathematical and visual concepts. A restless drive to create, to see what happens in making something, can provide the driving force in crafts. (Editor)

  13. The UCAR Africa Initiative: Enabling African Solutions to African Needs

    Science.gov (United States)

    Pandya, R.; Bruintjes, R.; Foote, B.; Heck, S.; Hermann, S.; Hoswell, L.; Konate, M.; Kucera, P.; Laing, A.; Lamptey, B.; Moncrieff, M.; Ramamurthy, M.; Roberts, R.; Spangler, T.; Traoré, A.; Yoksas, T.; Warner, T.

    2007-12-01

    The University Corporation for Atmospheric Research (UCAR) Africa Initiative (AI) is a coordinated effort aimed at building sustainable partnerships between UCAR and African institutions in order to pursue research and applications for the benefit of the African people. The initiative is based on four fundamental operating principles, concisely summarized by the overall philosophy of enabling African solutions to African needs. The four principles are: • Collaborate with African institutions • Focus on institutional capacity building and research support • Explore science research themes critical to Africa and important for the world • Leverage the research infrastructure in UCAR to add value These principles are realized in a set of pilot activities, chosen for their high probability of short-term results and ability to set the stage for longer-term collaboration. The three pilot activities are listed below. 1. A modest radar network and data-distribution system in Mali and Burkina Faso, including a data-sharing MOU between the Mail and Burkina Faso Weather Services. 2. A partnership among UCAR, the Ghana Meteorological Agency, and the Ghana university community to develop an operational Weather Research and Forecasting (WRF) model for West Africa. The output is used by researchers and operational forecasters in Africa. Model output is also part of a demonstration project that aims to allow humanitarian agencies to share geo-referenced information in Africa via a web portal. 3. A workshop in Ouagadougou, Burkina Faso from April 2-6, 2007, with the theme Improving Lives by Understanding Weather. The workshop, co-organized with Programme SAAGA and the Commité Permanent Inter-Etats de Lutte Contre la Sécheresse dans le Sahel (CILSS), included over 80 participants from 18 countries, and produced a set of recommendations for continued collaboration. Our presentation will provide an update of these pilot activities and point to future directions. Recognizing

  14. Triggering Sublimation-driven Activity of Main Belt Comets

    Science.gov (United States)

    Haghighipour, N.; Maindl, T. I.; Schäfer, C.; Speith, R.; Dvorak, R.

    2016-10-01

    It has been suggested that the comet-like activity of main belt comets (MBCs) is due to the sublimation of sub-surface water–ice that has been exposed as a result of their surfaces being impacted by meter-sized bodies. We have examined the viability of this scenario by simulating impacts between meter-sized and kilometer-sized objects using a smooth particle hydrodynamics approach. Simulations have been carried out for different values of the impact velocity and impact angle, as well as different target material and water-mass fractions. Results indicate that for the range of impact velocities corresponding to those in the asteroid belt, the depth of an impact crater is slightly larger than 10 m, suggesting that if the activation of MBCs is due to the sublimation of sub-surface water–ice, this ice has to exist no deeper than a few meters from the surface. Results also show that ice exposure occurs in the bottom and on the interior surface of impact craters, as well as on the surface of the target where some of the ejected icy inclusions are re-accreted. While our results demonstrate that the impact scenario is indeed a viable mechanism to expose ice and trigger the activity of MBCs, they also indicate that the activity of the current MBCs is likely due to ice sublimation from multiple impact sites and/or the water contents of these objects (and other asteroids in the outer asteroid belt) is larger than the 5% that is traditionally considered in models of terrestrial planet formation, providing more ice for sublimation. We present the details of our simulations and discuss their results and implications.

  15. DREAM3D simulations of inner-belt dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Gregory Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-26

    A 1973 paper by Lyons and Thorne explains the two-belt structure for electrons in the inner magnetosphere as a balance between inward radial diffusion and loss to the atmosphere, where the loss to the atmosphere is enabled by pitch-angle scattering from Coulomb and wave-particle interactions. In the 1973 paper, equilibrium solutions to a decoupled set of 1D radial diffusion equations, one for each value of the first invariant of motion, μ, were computed to produce the equilibrium two-belt structure. Each 1D radial diffusion equation incorporated an L-and μ-dependent `lifetime' due to the Coulomb and wave-particle interactions. This decoupling of the problem is appropriate under the assumption that radial diffusion is slow in comparison to pitch-angle scattering. However, for some values of μ and L the lifetime associated with pitch-angle scattering is comparable to the timescale associated with radial diffusion, suggesting that the true equilibrium solutions might reflect `coupled modes' involving pitch-angle scattering and radial diffusion and thus requiring a 3D diffusion model. In the work we show here, we have computed the equilibrium solutions using our 3D diffusion model, DREAM3D, that allows for such coupling. We find that the 3D equilibrium solutions are quite similar to the solutions shown in the 1973 paper when we use the same physical models for radial diffusion and pitch-angle scattering from hiss. However, we show that the equilibrium solutions are quite sensitive to various aspects of the physics model employed in the 1973 paper that can be improved, suggesting that additional work needs to be done to understand the two-belt structure.

  16. Archaean greenstone belts and associated granitic rocks - A review

    Science.gov (United States)

    Anhaeusser, Carl R.

    2014-12-01

    Archaean greenstone belts and associated granitic rocks comprise some of the most diverse rock types on the Earth's surface and were formed during the early stages of the development of the planet from Eoarchaean to Neoarchaean times - a period extending back from about 4000 to 2500 million years ago. Because of their great age, these rocks have received unprecedented attention from a wide spectrum of Earth scientists striving to learn more about the evolution of the Earth, including its crust, hydrosphere, atmosphere, the commencement of life, and the nature and distribution of mineral deposits. The knowledge gained thus far has accumulated incrementally, beginning with solid field-based studies, the latter being supplemented with increasingly advanced technological developments that have enabled scientists to probe fundamental questions of Earth history. Archaean granite-greenstone terranes display considerable variability of lithologies and geotectonic events, yet there are unifying characteristics that distinguish them from other geological environments. Most greenstone belts consist of a wide variety of volcanic and sedimentary rocks that reflect different evolutionary conditions of formation and all have invariably been influenced by subsequent geotectonic factors, including the intrusion of ultramafic, mafic and granitic complexes, resulting in widespread deformation, metamorphism, metasomatism, as well as mineralization. Geochemical and isotopic age determinations have shown how complex these ancient rocks are and efforts at understanding the nature and evolution of the hydrosphere, atmosphere and primitive life have made Archaean terranes exciting environments in which to study. Conflicting views as to the nature, history and origin of many of the rock types and events in Archaean terranes has been ongoing and stimulating. This review attempts to describe the main lithotypes and other characteristics of granite-greenstone belt geology and points to some

  17. On the oldest asteroid families in the main belt

    Science.gov (United States)

    Carruba, V.; Nesvorný, D.; Aljbaae, S.; Domingos, R. C.; Huaman, M.

    2016-06-01

    Asteroid families are groups of minor bodies produced by high-velocity collisions. After the initial dispersions of the parent bodies fragments, their orbits evolve because of several gravitational and non-gravitational effects, such as diffusion in mean-motion resonances, Yarkovsky and Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effects, close encounters of collisions, etc. The subsequent dynamical evolution of asteroid family members may cause some of the original fragments to travel beyond the conventional limits of the asteroid family. Eventually, the whole family will dynamically disperse and no longer be recognizable. A natural question that may arise concerns the time-scales for dispersion of large families. In particular, what is the oldest still recognizable family in the main belt? Are there any families that may date from the late stages of the late heavy bombardment and that could provide clues on our understanding of the primitive Solar system? In this work, we investigate the dynamical stability of seven of the allegedly oldest families in the asteroid main belt. Our results show that none of the seven studied families has a nominally mean estimated age older than 2.7 Gyr, assuming standard values for the parameters describing the strength of the Yarkovsky force. Most `paleo-families' that formed between 2.7 and 3.8 Gyr would be characterized by a very shallow size-frequency distribution, and could be recognizable only if located in a dynamically less active region (such as that of the Koronis family). V-type asteroids in the central main belt could be compatible with a formation from a paleo-Eunomia family.

  18. Schistosomes in South African penguins.

    Science.gov (United States)

    Aldhoun, Jitka A; Horne, Elizabeth C

    2015-01-01

    During the years 2009-2012, faeces of African penguins (Spheniscus demersus L.) from South African rehabilitation centres were examined for helminths. In total, 46 out 555 samples (8.29 %), mostly belonging to adult birds, were found to contain oval schistosome eggs with a spine on one pole. Their dimensions were 153.21 ± 9.07 × 87.14 ± 8.67 μm. Selected DNA fragments (18S, 28S and ITS rDNA) were sequenced and compared to other schistosome isolates deposited in GenBank. The shape of the eggs suggests that they belong to the genus Gigantobilharzia; however, due to the insufficient stage of knowledge of the genus and limited number of species available for comparison, we were not able to assign the isolate unambiguously to this genus based on either the egg morphology or the results of molecular analysis.

  19. African palm ethno-medicine

    DEFF Research Database (Denmark)

    Gruca, Marta; Blach-Overgaard, Anne; Balslev, Henrik

    2015-01-01

    Ethnopharmacological relevance This study is the first to demonstrate the breadth and patterns of the medicinal applications of African palms. It sheds light on species with the potential to provide new therapeutic agents for use in biomedicine; and links the gap between traditional use of palms...... and pharmacological evaluation for the beneficial effects of palm products on human health. Last but not least, the study provides recommendations for the areas that should be targeted in future ethno-botanical surveys. Aim of the study The primary objective of this survey was to assemble all available ethno-medicinal...... data on African palms, and investigate patterns of palm uses in traditional medicine; and highlight possible under-investigated areas. Materials and methods References were found through bibliographic searches using several sources including PubMed, Embase, and Google Scholar and search engines...

  20. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans......-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration. This thesis summarizes my research on the autumn migration...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...