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1

Implications of the Economic Interactions between Northern and Southern Tribes of Sudan  

Microsoft Academic Search

The present paper discusses issues of the tribal interactions living on the borders between North and South Sudan. Foresights are looked for, especially after secession. There are multiple ethnic relations and mutual resources collectively utilized. Different tribes live on those resources, in specifics those who depend on a livelihood of herding cattle, camels, sheep and goats. The conceptions of no-borders,

Issam A. W. Mohamed

2010-01-01

2

Integrated Mapping of Neglected Tropical Diseases: Epidemiological Findings and Control Implications for Northern Bahr-el-Ghazal State, Southern Sudan  

Microsoft Academic Search

Background: There are few detailed data on the geographic distribution of most neglected tropical diseases (NTDs) in post- conflict Southern Sudan. To guide intervention by the recently established national programme for integrated NTD control, we conducted an integrated prevalence survey for schistosomiasis, soil-transmitted helminth (STH) infection, lymphatic filariasis (LF), and loiasis in Northern Bahr-el-Ghazal State. Our aim was to establish

Hugh J. W. Sturrock; Diana Picon; Anthony Sabasio; David Oguttu; Emily Robinson; Mounir Lado; John Rumunu; Simon Brooker; Jan H. Kolaczinski

2009-01-01

3

Integrated Mapping of Neglected Tropical Diseases: Epidemiological Findings and Control Implications for Northern Bahr-el-Ghazal State, Southern Sudan  

PubMed Central

Background There are few detailed data on the geographic distribution of most neglected tropical diseases (NTDs) in post-conflict Southern Sudan. To guide intervention by the recently established national programme for integrated NTD control, we conducted an integrated prevalence survey for schistosomiasis, soil-transmitted helminth (STH) infection, lymphatic filariasis (LF), and loiasis in Northern Bahr-el-Ghazal State. Our aim was to establish which communities require mass drug administration (MDA) with preventive chemotherapy (PCT), rather than to provide precise estimates of infection prevalence. Methods and Findings The integrated survey design used anecdotal reports of LF and proximity to water bodies (for schistosomiasis) to guide selection of survey sites. In total, 86 communities were surveyed for schistosomiasis and STH; 43 of these were also surveyed for LF and loiasis. From these, 4834 urine samples were tested for blood in urine using Hemastix reagent strips, 4438 stool samples were analyzed using the Kato-Katz technique, and 5254 blood samples were tested for circulating Wuchereria bancrofti antigen using immunochromatographic card tests (ICT). 4461 individuals were interviewed regarding a history of ‘eye worm’ (a proxy measure for loiasis) and 31 village chiefs were interviewed regarding the presence of clinical manifestations of LF in their community. At the village level, prevalence of Schistosoma haematobium and S. mansoni ranged from 0 to 65.6% and from 0 to 9.3%, respectively. The main STH species was hookworm, ranging from 0 to 70% by village. Infection with LF and loiasis was extremely rare, with only four individuals testing positive or reporting symptoms, respectively. Questionnaire data on clinical signs of LF did not provide a reliable indication of endemicity. MDA intervention thresholds recommended by the World Health Organization were only exceeded for urinary schistosomiasis and hookworm in a few, yet distinct, communities. Conclusion This was the first attempt to use an integrated survey design for this group of infections and to generate detailed results to guide their control over a large area of Southern Sudan. The approach proved practical, but could be further simplified to reduce field work and costs. The results show that only a few areas need to be targeted with MDA of PCT, thus confirming the importance of detailed mapping for cost-effective control.

Sturrock, Hugh J. W.; Picon, Diana; Sabasio, Anthony; Oguttu, David; Robinson, Emily; Lado, Mounir; Rumunu, John; Brooker, Simon; Kolaczinski, Jan H.

2009-01-01

4

Blinding Trachoma in Postconflict Southern Sudan  

PubMed Central

Background Trachoma is a leading cause of preventable blindness. Reports from eye surgery camps and anecdotal data indicated that blinding trachoma is a serious cause of visual impairment in Mankien payam (district) of southern Sudan. We conducted this study to estimate the prevalence of trachoma, estimate targets for interventions, and establish a baseline for monitoring and evaluation. Methods and Findings A population-based cross-sectional survey was conducted in May 2005. A two-stage cluster random sampling with probability proportional to size was used to select the sample population. Participants were examined for trachoma by experienced graders using the World Health Organization simplified grading scheme. A total of 3,567 persons were examined (89.7% of those enumerated) of whom 2,017 were children aged less than 15 y and 1,550 were aged 15 y and above. Prevalence of signs of active trachoma in children aged 1–9 y was: trachomatous inflammation-follicular (TF) = 57.5% (95% confidence interval [CI], 54.5%–60.4%); trachomatous inflammation-intense (TI) = 39.8% (95% CI, 36.3%–43.5%); and TF and/or TI (active trachoma) = 63.3% (95% CI, 60.1%–66.4%). Prevalence of trachomatous trichiasis was 9.6% (95% CI, 8.4%–10.9%) in all ages, 2.3% (95% CI, 1.6%–3.2%) in children aged under 15 y, and 19.2% (95% CI, 17.0%–21.7%) in adults. Men were equally affected by trichiasis as women: odds ratio = 1.09 (95% CI, 0.81%–1.47%). It is estimated that there are up to 5,344 persons requiring trichiasis surgery in Mankien payam. Conclusions Trachoma is a serious public health problem in Mankien, and the high prevalence of trichiasis in children underscores the severity of blinding trachoma. There is an urgent need to implement the surgery, antibiotics, facial cleanliness, and environmental change (SAFE) strategy for trachoma control in Mankien payam, and the end of the 21-y civil war affords an opportunity to do this.

Ngondi, Jeremiah; Ole-Sempele, Francis; Onsarigo, Alice; Matende, Ibrahim; Baba, Samson; Reacher, Mark; Matthews, Fiona; Brayne, Carol; Emerson, Paul

2006-01-01

5

Viewing the Reconstruction of Primary Schooling in Southern Sudan through Education Data, 2006-2009  

ERIC Educational Resources Information Center

After one of the longest wars in the history of Africa, Southern Sudan accomplished one of the world's quickest education reconstruction programmes. Once the Comprehensive Peace Agreement (CPA) was signed in 2005, the international donor community and the government and people of Southern Sudan united under a common goal: to increase access to…

Kim, HyeJin; Moses, Kurt D.; Jang, Bosun; Wils, Annababette

2011-01-01

6

Prevalence and Causes of Blindness and Low Vision in Southern Sudan  

Microsoft Academic Search

Background Blindness and low vision are thought to be common in southern Sudan. However, the magnitude and geographical distribution are largely unknown. We aimed to estimate the prevalence of blindness and low vision, identify the main causes of blindness and low vision, and estimate targets for blindness prevention programs in Mankien payam (district), southern Sudan.

Jeremiah Ngondi; Francis Ole-Sempele; Alice Onsarigo; Ibrahim Matende; Samson Baba; Mark Reacher; Fiona Matthews; Carol Brayne; Paul M. Emerson

2006-01-01

7

Plight of a displaced woman in southern Sudan.  

PubMed

Southern Sudanese have been displaced due to tribal conflicts and civil war between the Islamic Khartoum government in the North and the predominantly Christian South. This article narrates the plight of displaced Southern Sudanese women, particularly that of a woman named Rebecca Akwach during her journey towards Nzara to escape air raids by the Khartoum government. The war that plagued Southern Sudan for the past 11 years has burdened numerous women with the responsibility of bringing up their children single-handedly. Most of the husbands have been killed in battle, separated through displacement, or have fled to other countries. Approximately 500 displaced people, including pregnant women, have walked some 300 km westward to a small town in western Ethiopia. During their ordeal, meals was reduced to once daily or none at all, while others barter whatever valuables they have for food. Malnutrition, malaria, diarrhea, respiratory tract infection and measles were prevalent. Pregnant women have an added burden of carrying valuables and small children who cannot walk 10 km a day. Akwach and other sojourners are now in Nzara and are waiting for the allocation of land where they can temporarily settle. PMID:12349363

Ogana, W

1993-01-01

8

Collaborative Evaluation and Market Research Converge: An Innovative Model Agricultural Development Program Evaluation in Southern Sudan  

ERIC Educational Resources Information Center

In June and July 2006 a team of outside experts arrived in Yei, Southern Sudan through an AID project to provide support to a local agricultural development project. The team brought evaluation, agricultural marketing and financial management expertise to the in-country partners looking at steps to rebuild the economy of the war ravaged region. A…

O'Sullivan, John M.; O'Sullivan, Rita

2012-01-01

9

Aquatic snails of the Jonglei region, southern Sudan, and transmission of trematode parasites  

Microsoft Academic Search

An account is given of the aquatic gastropod molluscs obtained in a survey made to assess future ecological effects of the Jonglei Canal now under construction in the Sudd region of southern Sudan. A total of about 23 species of aquatic snail lives in this region, of which a number are utilised as intermediate hosts by trematode parasites infecting man,

D. S. Brown; T. Fison; V. R. Southgate; C. A. Wright

1984-01-01

10

Collaborative evaluation and market research converge: an innovative model agricultural development program evaluation in Southern Sudan.  

PubMed

In June and July 2006 a team of outside experts arrived in Yei, Southern Sudan through an AID project to provide support to a local agricultural development project. The team brought evaluation, agricultural marketing and financial management expertise to the in-country partners looking at steps to rebuild the economy of the war ravaged region. A partnership of local officials, agricultural development staff, and students worked with the outside team to craft a survey of agricultural traders working between northern Uganda and Southern Sudan the steps approach of a collaborative model. The goal was to create a market directory of use to producers, government officials and others interested in stimulating agricultural trade. The directory of agricultural producers and distributors served as an agricultural development and promotion tool as did the collaborative process itself. PMID:22309968

O'Sullivan, John M; O'Sullivan, Rita

2012-11-01

11

Targeting Trachoma Control through Risk Mapping: The Example of Southern Sudan  

Microsoft Academic Search

BackgroundTrachoma is a major cause of blindness in Southern Sudan. Its distribution has only been partially established and many communities in need of intervention have therefore not been identified or targeted. The present study aimed to develop a tool to improve targeting of survey and control activities.Methods\\/Principal FindingsA national trachoma risk map was developed using Bayesian geostatistics models, incorporating trachoma

Archie C. A. Clements; Lucia W. Kur; Gideon Gatpan; Jeremiah M. Ngondi; Paul M. Emerson; Mounir Lado; Anthony Sabasio; Jan H. Kolaczinski

2010-01-01

12

Rehabilitating gum arabic systems in Sudan: Economic and environmental implications  

Microsoft Academic Search

The economic and environmental benefits of gum arabic production in the Sudano-Sahelian zone appear attractive. However, the farm-level economics of gum arabic production is complex, and much more needs to be understood about the economic-environmental interactions determining farmers' gum cropping. The following paper explores these issues in Sudan through a crop profitability analysis of gum and other crops combined with

Edward B. Barbier

1992-01-01

13

Targeting Trachoma Control through Risk Mapping: The Example of Southern Sudan  

PubMed Central

Background Trachoma is a major cause of blindness in Southern Sudan. Its distribution has only been partially established and many communities in need of intervention have therefore not been identified or targeted. The present study aimed to develop a tool to improve targeting of survey and control activities. Methods/Principal Findings A national trachoma risk map was developed using Bayesian geostatistics models, incorporating trachoma prevalence data from 112 geo-referenced communities surveyed between 2001 and 2009. Logistic regression models were developed using active trachoma (trachomatous inflammation follicular and/or trachomatous inflammation intense) in 6345 children aged 1–9 years as the outcome, and incorporating fixed effects for age, long-term average rainfall (interpolated from weather station data) and land cover (i.e. vegetation type, derived from satellite remote sensing), as well as geostatistical random effects describing spatial clustering of trachoma. The model predicted the west of the country to be at no or low trachoma risk. Trachoma clusters in the central, northern and eastern areas had a radius of 8 km after accounting for the fixed effects. Conclusion In Southern Sudan, large-scale spatial variation in the risk of active trachoma infection is associated with aridity. Spatial prediction has identified likely high-risk areas to be prioritized for more data collection, potentially to be followed by intervention.

Clements, Archie C. A.; Kur, Lucia W.; Gatpan, Gideon; Ngondi, Jeremiah M.; Emerson, Paul M.; Lado, Mounir; Sabasio, Anthony; Kolaczinski, Jan H.

2010-01-01

14

Prevalence and Causes of Blindness and Low Vision in Southern Sudan  

PubMed Central

Background Blindness and low vision are thought to be common in southern Sudan. However, the magnitude and geographical distribution are largely unknown. We aimed to estimate the prevalence of blindness and low vision, identify the main causes of blindness and low vision, and estimate targets for blindness prevention programs in Mankien payam (district), southern Sudan. Methods and Findings A cross-sectional survey of the population aged 5 y and above was conducted in May 2005 using a two-stage cluster random sampling with probability proportional to size. The Snellen E chart was used to test visual acuity, and participants also underwent basic eye examination. Vision status was defined using World Health Organization categories of visual impairment based on presenting visual acuity (VA). A total of 2,954 persons were enumerated and 2,499 (84.6%) examined. Prevalence of blindness (presenting VA of less than 3/60 in the better eye) was 4.1% (95% confidence interval [CI], 3.4–4.8); prevalence of low vision (presenting VA of at least 3/60 but less than 18/60 in the better eye) was 7.7% (95% CI, 6.7–8.7); whereas prevalence of monocular visual impairment (presenting VA of at least 18/60 in better eye and VA of less than 18/60 in other eye) was 4.4% (95% CI, 3.6–5.3). The main causes of blindness were considered to be cataract (41.2%) and trachoma (35.3%), whereas low vision was mainly caused by trachoma (58.1%) and cataract (29.3%). It is estimated that in Mankien payam 1,154 persons aged 5 y and above (lower and upper bounds = 782–1,799) are blind, and 2,291 persons (lower and upper bounds = 1,820–2,898) have low vision. Conclusions Blindness is a serious public health problem in Mankien, and there is urgent need to implement comprehensive blindness prevention programs. Further surveys are essential to confirm these tragic findings and estimate prevalence of blindness and low vision in the entire region of southern Sudan in order to facilitate planning of VISION 2020 objectives.

Ngondi, Jeremiah; Ole-Sempele, Francis; Onsarigo, Alice; Matende, Ibrahim; Baba, Samson; Reacher, Mark; Matthews, Fiona; Brayne, Carol; Emerson, Paul M

2006-01-01

15

Integrated Surveys of Neglected Tropical Diseases in Southern Sudan: How Much Do They Cost and Can They Be Refined?  

PubMed Central

Background Increasing emphasis on integrated control of neglected tropical diseases (NTDs) requires identification of co-endemic areas. Integrated surveys for lymphatic filariasis (LF), schistosomiasis and soil-transmitted helminth (STH) infection have been recommended for this purpose. Integrated survey designs inevitably involve balancing the costs of surveys against accuracy of classifying areas for treatment, so-called implementation units (IUs). This requires an understanding of the main cost drivers and of how operating procedures may affect both cost and accuracy of surveys. Here we report a detailed cost analysis of the first round of integrated NTD surveys in Southern Sudan. Methods and Findings Financial and economic costs were estimated from financial expenditure records and interviews with survey staff using an ingredients approach. The main outcome was cost per IU surveyed. Uncertain variables were subjected to univariate sensitivity analysis and the effects of modifying standard operating procedures were explored. The average economic cost per IU surveyed was USD 40,206 or USD 9,573, depending on the size of the IU. The major cost drivers were two key categories of recurrent costs: i) survey consumables, and ii) personnel. Conclusion The cost of integrated surveys in Southern Sudan could be reduced by surveying larger administrative areas for LF. If this approach was taken, the estimated economic cost of completing LF, schistosomiasis and STH mapping in Southern Sudan would amount to USD 1.6 million. The methodological detail and costing template provided here could be used to generate cost estimates in other settings and readily compare these to the present study, and may help budget for integrated and single NTDs surveys elsewhere.

Kolaczinski, Jan H.; Hanson, Kara; Robinson, Emily; Picon, Diana; Sabasio, Anthony; Mpakateni, Martin; Lado, Mounir; Moore, Stephen; Petty, Nora; Brooker, Simon

2010-01-01

16

Trachoma Rapid Assessments in Unity and Northern Bahr-el-Ghazal States, Southern Sudan  

PubMed Central

Background Trachoma is thought to be endemic over large parts of Southern Sudan, but empirical evidence is limited. While some areas east of the Nile have been identified as highly endemic, few trachoma surveys have been conducted in the remainder of the country. This study aimed to determine whether trachoma constitutes a problem to public health in Northern Bahr-el-Ghazal and Unity State, both located west of the Nile. Methods and Principal Findings Trachoma rapid assessments (TRA) were conducted between July and September 2009. Seven villages in Northern Bahr-el-Ghazal State and 13 villages in Unity State were surveyed; an average of 50 children (age 1–9 years) and 44 women (age 15 years and above) were examined per village. Samples for analysis using the APTIMA Combo-2 nucleic acid amplification test (NAAT) were collected from participants with active trachoma in eight villages in Unity State. In Northern Bahr-el-Ghazal State, only three children with active trachoma (trachomatous inflammation follicular (TF) and/or trachomatous inflammation intense (TI)) and two women with trichiasis (TT) were found, in two of the seven villages surveyed. In Unity State, trachoma was endemic in all thirteen villages surveyed; the proportion of children with active trachoma ranged from 33% to 75% between villages, while TF in children ranged from 16% to 44%. Between 4% to 51% of examined women showed signs of TT. Samples from active trachoma cases tested using the NAAT were positive for Chlamydia trachomatis infection for 46.6% of children and 19.0% of women. Conclusions Trachoma presents a major problem to public health Unity State, while the disease is of low priority in Northern-Bahr-el-Ghazal State. Implementation of a population-based prevalence survey is now required in Unity State to generate baseline prevalence data so that trachoma interventions can be initiated and monitored over time.

Robinson, Emily; Kur, Lucia W.; Ndyaba, Aggrey; Lado, Mounir; Shafi, Juma; Kabare, Emmanuel; McClelland, R. Scott; Kolaczinski, Jan H.

2010-01-01

17

They Own This: Mother Tongue Instruction for Indigenous Kuku Children in Southern Sudan  

ERIC Educational Resources Information Center

This article details a pilot program of mother tongue instruction in five primary schools for classes one through three, in Kajokeji County, Central Equatoria State, South Sudan. The program was launched by teachers and volunteers with the support of the Jesuit Refugee Service, an international non-governmental organization. The research examines…

Laguarda, Ana Isabel; Woodward, Walter Pierce

2013-01-01

18

Obstetric fistula in Southern Sudan: situational analysis and Key Informant Method to estimate prevalence  

PubMed Central

Background Obstetric fistula is a severe condition which can have devastating consequences for a woman’s life. Despite a considerable literature, very little is known about its prevalence. This project was conducted to carry out a situational analysis of fistula services in South Sudan and to pilot test the Key Informant Method (KIM) to estimate the prevalence of fistula in a region of South Sudan. Methods Key stakeholder interviews, document reviews and fistula surgery record reviews were undertaken. A KIM survey was conducted in a district of Western Bahr-el-Ghazal in January 2012. One hundred sixty-six community-based distributors, traditional birth attendants and village midwives were trained as key informants to identify women with fistula in the community. Women identified were subsequently examined by an obstetrician and nurse to verify whether they had a fistula. Results There were limited fistula repair services in South Sudan. Approximately 50–80 women per year attend periodic campaigns, with around half having a fistula and receiving a repair. On average a further 5 women a year received fistula repair from hospital services. Ten women with potential fistula were identified via KIM; all confirmed by the obstetrician. Of these, three were from the survey area, which had 8,865 women of reproductive age (15–49 years). This gives a minimal estimated prevalence of at least 30 fistulas per 100,000 women of reproductive age (95% CI 10–100). Conclusions Routine fistula repair services available do not meet the population’s needs. The pilot study suggests that KIM can be used to identify women with fistula in the community. Data on fistula are generally poor; the KIM methodology we used in South Sudan yielded a lower fistula prevalence than estimates reported previously in the region.

2013-01-01

19

Post-conflict mental health needs: a cross-sectional survey of trauma, depression and associated factors in Juba, Southern Sudan  

PubMed Central

Background The signing of the Comprehensive Peace Agreement in January 2005 marked the end of the civil conflict in Sudan lasting over 20 years. The conflict was characterised by widespread violence and large-scale forced migration. Mental health is recognised as a key public health issue for conflict-affected populations. Studies revealed high levels of post-traumatic stress disorder (PTSD) amongst populations from Southern Sudan during the conflict. However, no studies have been conducted on mental health in post-war Southern Sudan. The objective of this study was to measure PTSD and depression in the population in the town of Juba in Southern Sudan; and to investigate the association ofdemographic, displacement, and past and recent trauma exposure variables, on the outcomes of PTSD and depression. Methods A cross-sectional, random cluster survey with a sample of 1242 adults (aged over 18 years) was conducted in November 2007 in the town of Juba, the capital of Southern Sudan. Levels of exposure to traumatic events and PTSD were measured using the Harvard Trauma Questionnaire (original version), and levels of depression measured using the Hopkins Symptom Checklist-25. Multivariate logistic regression was used to analyse the association ofdemographic, displacement and trauma exposure variables on the outcomes of PTSD and depression. Multivariate logistic regression was also conducted to investigate which demographic and displacement variables were associated with exposure to traumatic events. Results Over one third (36%) of respondents met symptom criteria for PTSD and half (50%) of respondents met symptom criteria for depression. The multivariate logistic regression analysis showed strong associations of gender, marital status, forced displacement, and trauma exposure with outcomes of PTSD and depression. Men, IDPs, and refugees and persons displaced more than once were all significantly more likely to have experienced eight or more traumatic events. Conclusion This study provides evidence of high levels of mental distress in the population of Juba Town, and associated risk-factors. Comprehensive social and psychological assistance is urgently required in Juba.

Roberts, Bayard; Damundu, Eliaba Yona; Lomoro, Olivia; Sondorp, Egbert

2009-01-01

20

The influence of demographic characteristics, living conditions, and trauma exposure on the overall health of a conflict-affected population in Southern Sudan  

PubMed Central

Background There remains limited evidence on how armed conflict affects overall physical and mental well-being rather than specific physical or mental health conditions. The aim of this study was to investigate the influence of demographic characteristics, living conditions, and violent and traumatic events on general physical and mental health in Southern Sudan which is emerging from 20 years of armed conflict. Methods A cross-sectional survey of 1228 adults was conducted in November 2007 in the town of Juba, the capital of Southern Sudan. Multivariate linear regression analysis was used to investigate the associations and relative influence of variables in three models of demographic characteristics, living conditions, and trauma exposure, on general physical and mental health status. These models were run separately and also as a combined model. Data quality and the internal consistency of the health status instrument (SF-8) were assessed. Results The variables in the multivariate analysis (combined model) with negative coefficients of association with general physical health and mental health (i.e. worse health), respectively, were being female (coef. -2.47; -2.63), higher age (coef.-0.16; -0.17), absence of soap in the household (physical health coef. -2.24), and experiencing within the past 12 months a lack of food and/or water (coef. -1.46; -2.27) and lack of medical care (coef.-3.51; -3.17). A number of trauma variables and cumulative exposure to trauma showed an association with physical and mental health (see main text for data). There was limited variance in results when each of the three models were run separately and when they were combined, suggesting the pervasive influence of these variables. The SF-8 showed good data quality and internal consistency. Conclusions This study provides evidence on the pervasive influence of demographic characteristics, living conditions, and violent and traumatic events on the general physical and mental health of a conflict-affected population in Southern Sudan, and highlights the importance of addressing all these influences on overall health.

2010-01-01

21

TRIASSIC-JURASSIC BOUNDARY ON THE SOUTHERN MARGIN OF TETHYS: IMPLICATIONS OF FACIES, TECTONICS AND VOLCANISM  

Microsoft Academic Search

The facies changes, tectonics and magmatism across the Triassic-Jurassic boundary in the southern Tethyan margin have been studied in Egypt, Sudan, Jordan and Saudi Arabia. In Saudi Arabia and Jordan an unconformable contact is recognized between the Upper Triassic and Lower Jurassic rocks. This unconformity surface is marked by the truncation of the fluvial clastics of the uppermost Triassic before

MOHAMED A. KHALIFA

22

Seismotectonic implications of sand blows in the southern Mississippi Embayment  

Microsoft Academic Search

We explore seismically-induced sand blows from the southern Mississippi Embayment and their implications in resolving the question of near or distal epicentral source region. This was accomplished using aerial photography, field excavations, and cone penetration tests. Our analysis shows that three sand blow fields exhibit a distinct chronology of strong ground motion for the southern embayment: (1) The Ashley County,

R. T. Cox; A. A. Hill; D. Larsen; T. Holzer; S. L Forman; T. Noce; C. Gardner; J. Morat

2007-01-01

23

Flood pulsing in the Sudd wetland: analysis of seasonal variations in 2 inundation and evapotranspiration in Southern Sudan  

USGS Publications Warehouse

Located on the Bahr el Jebel in South Sudan, the Sudd is one of the largest floodplain wetlands in the world. Seasonal inundation drives the hydrologic, geomorphological, and ecological processes, and the annual flood pulse is essential to the functioning of the Sudd. Despite the importance of the flood pulse, various hydrological interventions are planned upstream of the Sudd to increase economic benefits and food security. These will not be without consequences, in particular for wetlands where the biological productivity, biodiversity, and human livelihoods are dependent on the flood pulse and both the costs and benefits need to be carefully evaluated. Many African countries still lack regional baseline information on the temporal extent, distribution, and characteristics of wetlands, making it hard to assess the consequences of development interventions. Because of political instability in Sudan and the inaccessible nature of the Sudd, recent measurements of flooding and seasonal dynamics are inadequate. Analyses of multitemporal and multisensor remote sensing datasets are presented in this paper, in order to investigate and characterize flood pulsing within the Sudd wetland over a 12-month period. Wetland area has been mapped along with dominant components of open water and flooded vegetation at five time periods over a single year. The total area of flooding (both rain and river fed) over the 12 months was 41 334 km2, with 9176 km2 of this constituting the permanent wetland. Mean annual total evaporation is shown to be higher and with narrower distribution of values from areas of open water (1718 mm) than from flooded vegetation (1641 mm). Although the exact figures require validation against ground-based measurements, the results highlight the relative differences in inundation patterns and evaporation across the Sudd.

Gabriel Senay; Rebelo, L-M.; McCartney, M. P.

2012-01-01

24

Spectral P-wave magnitudes, magnitude spectra and other source parameters for the 1990 southern Sudan and the 2005 Lake Tanganyika earthquakes  

NASA Astrophysics Data System (ADS)

Teleseismic Broadband seismograms of P-waves from the May 1990 southern Sudan and the December, 2005 Lake Tanganyika earthquakes; the western branch of the East African Rift System at different azimuths have been investigated on the basis of magnitude spectra. The two earthquakes are the largest shocks in the East African Rift System and its extension in southern Sudan. Focal mechanism solutions along with geological evidences suggest that the first event represents a complex style of the deformation at the intersection of the northern branch of the western branch of the East African Rift and Aswa Shear Zone while the second one represents the current tensional stress on the East African Rift. The maximum average spectral magnitude for the first event is determined to be 6.79 at 4 s period compared to 6.33 at 4 s period for the second event. The other source parameters for the two earthquakes were also estimated. The first event had a seismic moment over fourth that of the second one. The two events are radiated from patches of faults having radii of 13.05 and 7.85 km, respectively. The average displacement and stress drop are estimated to be 0.56 m and 1.65 MPa for the first event and 0.43 m and 2.20 MPa for the second one. The source parameters that describe inhomogeneity of the fault are also determined from the magnitude spectra. These additional parameters are complexity, asperity radius, displacements across the asperity and ambient stress drop. Both events produce moderate rupture complexity. Compared to the second event, the first event is characterized by relatively higher complexity, a low average stress drop and a high ambient stress. A reasonable explanation for the variations in these parameters may suggest variation in the strength of the seismogenic fault which provides the relations between the different source parameters. The values of stress drops and the ambient stresses estimated for both events indicate that these earthquakes are of interplate type.

Moussa, Hesham Hussein Mohamed

2008-10-01

25

DEM-optical-radar data integration for palaeohydrological mapping in the northern Darfur, Sudan: implication for groundwater exploration  

Microsoft Academic Search

North?western Sudan, as a part of the eastern Sahara, is among the driest places on earth. However, the region underwent drastic climatic changes through the alternation of dry and wet conditions in the past. During humid phases, when the rain was plentiful over a prolonged time period, the surface was veined by rivers and dotted by large lakes. The new

E. Ghoneim; F. El-Baz

2007-01-01

26

A climate trend analysis of Sudan  

USGS Publications Warehouse

Summer rains in western and southern Sudan have declined by 10-20 percent since the mid-1970s. Observed warming of more than 1 degree Celsius is equivalent to another 10-20 percent reduction in rainfall for crops. The warming and drying have impacted southern Darfur and areas around Juba. Rainfall declines west of Juba threaten southern Sudan's future food production prospects. In many cases, areas with changing climate are coincident with zones of substantial conflict, suggesting some degree of association; however, the contribution of climate change to these conflicts is not currently understood. Rapid population growth and the expansion of farming and pastoralism under a more variable climate regime could dramatically increase the number of at-risk people in Sudan over the next 20 years.

Funk, Chris; Eilerts, Gary; Verdin, Jim; Rowland, Jim; Marshall, Michael

2011-01-01

27

Al Jazirah, Sudan  

NASA Technical Reports Server (NTRS)

Al Jazirah (also Gezira) is one of the 26 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It is a well populated area suitable for agriculture. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. The region has benefited from the Gezira Scheme, a program to foster cotton farming begun in 1925. At that time the Sennar Dam and numerous irrigation canals were built. Al Jazirah became the Sudan's major agricultural region with more than 2.5 million acres (10,000 km) under cultivation. The initial development project was semi-private, but the government nationalized it in 1950. Cotton production increased in the 1970s but by the 1990s increased wheat production has supplanted a third of the land formerly seeded with cotton.

The image was acquired December 25, 2006, covers an area of 56 x 36.4 km, and is located near 14.5 degrees north latitude, 33.1 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.

2008-01-01

28

A case of African histoplasmosis from Sudan.  

PubMed

The first authentic case of African histoplasmosis from the Sudan is reported. The patient came from Dindir, along the southern part of the Blue Nile River. He had cutaneous and visceral leishmaniasis as well as the cutaneous form of African histoplasmosis. The latter was proved by culture and histopathology to be due to Histoplasma duboisii. The fungus was confined to the skin. H. duboisii may be more prevalent, and further studies in Dindir area are needed. PMID:3232196

Gumaa, S A; Ahmed, M A; Hassan, M E; Hassan, A M

1988-01-01

29

The origins and culture of blacksmiths in Kuku society of the Sudan, 1797–1955  

Microsoft Academic Search

The Kuku are a large ethnic group in the southern region of the Sudan. They belong to a cultural and linguistic group called the Eastern Nilotes. The Kuku are one of the last waves of the Eastern Nilotic group that occupied the territory now known as Kajo-Kaji. This land was originally inhabited by a Sudanic group of people called Moru-Madi.

Scopas Poggo

2006-01-01

30

Biogas energy technology in Sudan  

Microsoft Academic Search

Biogas from biomass appears to have potential as an alternative energy in Sudan, which is potentially rich in biomass resources. This is an overview of some salient points and perspectives of biogas technology in Sudan. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biogas technology. Sudan is blessed with abundant solar, wind, hydro, and

A. M. Omer; Y. Fadalla

2003-01-01

31

Sudan: The Crisis in Darfur and Status of the North-South Peace Agreement. (May 12, 2009).  

National Technical Information Service (NTIS)

Sudan, geographically the largest country in Africa, has been ravaged by civil war intermittently for four decades. More than 2 million people have died in Southern Sudan over the past two decades due to war-related causes and famine, and millions have be...

T. Dagne

2009-01-01

32

The Sudan Experience  

Microsoft Academic Search

This article featuring Sudan constitutes one of five articles in a collection of essays on local capacity-building in research\\u000a ethics by graduates from the University of Toronto’s Joint Centre for Bioethics MHSc in Bioethics, International Stream programme\\u000a funded by the Fogarty International Center for Advanced Study in the Health Sciences (FIC). Research ethics is a relatively\\u000a new area of practice

Ghaiaith Hussein

2008-01-01

33

Southern Africa Development Coordinating Conference and Its Security Implications.  

National Technical Information Service (NTIS)

Political independence to the nine black states in Southern Africa came in various forms. For countries like Botswana, Lesotho, Swaziland, Tanzania and Zambia the transition was fairly peaceful. In contrast, for Angola, Mozambique and Zimbabwe, independen...

L. M. Fisher

1989-01-01

34

Famine in Sudan  

NSDL National Science Digital Library

This week's In the News covers the famine in Sudan. The seven resources discussed offer news, analysis, and commentary. The largest country in Africa, Sudan has been wracked by civil strife and violence since becoming an independent republic in 1956. Years of civil war have devastated the Sudanese economy and society, killing over 1.2 million since 1983 alone. Despite this tortured history, Sudan may now be facing its worst crisis. After two years of drought, bad harvests and renewed fighting, over 2.5 million people require emergency food aid and malnutrition rates exceed 60% of the population in some areas. While international relief agencies have scrambled to assist, many estimate that only about half of what is needed in terms of money and material is arriving. While the weather has played a role in the current crisis, it is also a product of the long-running conflict between the Islamic government in the north and the mainly Christian south. An attempt to institute strict Islamic law in the south in 1983 touched off a conflict between the government and numerous rebel groups in the south, most importantly the Sudan's Peoples Liberation Army (SPLA), which became a full-scale civil war by the mid-1980s. Since then some concessions have been made to the South and several peace talks were held. The present situation was touched off in February, 1998 when local warlord Kerubino Kuanyin Bol, who had been fighting for the government, rejoined the rebellion, reigniting the conflict. Two weeks ago the government and the SPLA announced a one-month cease-fire to allow aid to get through, but many aid workers believe it may be too late. The rainy season has finally arrived, one moth late, hampering communication and the transportation of much-needed food and medicine. In the meantime, Sudan has rapidly become a destination of choice for documentary news photographers eager for startling and powerful photos. Whether or not sufficient aid will arrive in their wake remains to be seen.

De Nie, Michael W.

1998-01-01

35

Landscape – wildfire interactions in southern Europe: Implications for landscape management  

Microsoft Academic Search

Every year approximately half a million hectares of land are burned by wildfires in southern Europe, causing large ecological and socio-economic impacts. Climate and land use changes in the last decades have increased fire risk and danger. In this paper we review the available scientific knowledge on the relationships between landscape and wildfires in the Mediterranean region, with a focus

Francisco Moreira; Olga Viedma; Margarita Arianoutsou; Thomas Curt; Nikos Koutsias; Eric Rigolot; Anna Barbati; Piermaria Corona; Pedro Vaz; Gavriil Xanthopoulos; Florent Mouillot; Ertugrul Bilgili

2011-01-01

36

Structural and Sedimentological Development of Pahrump Basin, Southern Nevada with Implications for Seismic Hazards  

Microsoft Academic Search

The purpose of this study is to (1) document potentially active faults and estimate possible earthquake magnitudes, (2) document and analyze sedimentation in a basin controlled by strike-slip and oblique faults, and (3) consider implications on regional development using Pahrump Valley, southern Nevada as a case study. The 2.5 million people living within the region would be significantly impacted by

J. Carter; W. J. Taylor; B. Luke

2008-01-01

37

Seismic Hazard Implication of the Seismotectonics of southern Africa  

NASA Astrophysics Data System (ADS)

The work presented in this report / presentation was prepared as part of the requirements for the SIDA/IGCP Project 601 titled "Seismotectonics and Seismic Hazards in Africa" as well as part of the seismic source characterisation of the GEM-Africa Seismic hazard study. An effort was made to compile information necessary to prepare a seismotectonic map of Africa which can then be used in carrying out a seismic hazard assessment of the continent or locations within the continent. Information on major faults, fault plane solutions, geophysical data as well as stress data has so far been collected and included in a database for the southern Africa region. Reports published by several experts contributed much to the collected information. The seismicity data used are part of the earthquake catalogue being prepared for the GEM-Africa project, which includes historical and instrumental records as collected from various sources. An effort has been made to characterise the identified major faults and through further analysis investigate their possible impact on the seismic hazard of southern Africa.

Midzi, Vunganai; Mulabisana, Thifelimbilu; Manzunzu, Brassnavy

2014-05-01

38

Binding of Sudan II and Sudan IV to bovine serum albumin: comparison studies.  

PubMed

In this paper, we report the interaction of Sudan II and Sudan IV to bovine serum albumin (BSA). Structural analysis showed that both Sudan II and Sudan IV interact mainly with BSA at the hydrophobic pocket and via Van der Waals forces. The number of bound Sudan molecule for each protein molecule was approximately 1. The overall binding constants at 293 K (20°C) estimated for Sudan II and Sudan IV were 1.22 × 10(4)M(-1) and 1.48 × 10(4)M(-1), respectively. BSA backbone structure was damaged by the dyes with more severe phenomenon observed for Sudan IV. For two Sudan dyes with the same concentration, Sudan IV could cause more alterations on CD spectra of BSA with slight decrease of ?-helical content and increase of ?-sheet content, suggesting a partial protein unfolding. PMID:21951948

Lu, Dawei; Zhao, Xingchen; Zhao, Yingcan; Zhang, Bingcong; Zhang, Bin; Geng, Mengyang; Liu, Rutao

2011-12-01

39

Climate variability and El Niño Southern Oscillation: implications for natural coastal resources and management  

Microsoft Academic Search

The El Niño Southern Oscillation (ENSO) significantly influences marine ecosystems and the sustained exploitation of marine\\u000a resources in the coastal zone of the Humboldt Current upwelling system. Both its warm (El Niño: EN) and cold (La Niña: LN)\\u000a phase have drastic implications for the ecology, socio-economy and infrastructure along most of Pacific South America. Local\\u000a artisanal fisheries, which especially suffer

Sven Thatje; Olaf Heilmayer; Jürgen Laudien

2008-01-01

40

Leishmaniasis in Sudan. Visceral leishmaniasis.  

PubMed

From the early 1900s, visceral leishmaniasis (VL; kala-azar) has been among the most important health problems in Sudan, particularly in the main endemic area in the eastern and central regions. Several major epidemics have occurred, the most recent--in Western Upper Nile province in southern Sudan, detected in 1988--claiming over 100,000 lives. The disease spread to other areas that were previously not known to be endemic for VL. A major upsurge in the number of cases was noted in the endemic area. These events triggered renewed interest in the disease. Epidemiological and entomological studies confirmed Phlebotomus orientalis as the vector in several parts of the country, typically associated with Acacia seyal and Balanites aegyptiaca vegetation. Infection rates with Leishmania were high, but subject to seasonal variation, as were the numbers of sand flies. Parasites isolated from humans and sand flies belonged to three zymodemes (MON-18, MON-30 and MON-82), which all belong to the L. donovani sensu lato cluster. Transmission dynamics have not been elucidated fully; heavy transmission in relatively scarcely populated areas such as Dinder national park suggested zoonotic transmission whereas the large numbers of patients with post kala-azar dermal leishmaniasis (PKDL) in heavily affected villages may indicate a human reservoir and anthroponotic transmission. Clinical presentation in adults and in children did not differ significantly, except that children were more anaemic. Fever, weight loss, hepato-splenomegaly and lymphadenopathy were the most common findings. PKDL was much more common than expected (56% of patients with VL developed PKDL), but other post-VL manifestations were also found affecting the eyes (uveitis, conjunctivitis, blepharitis), nasal and/or oral mucosa. Evaluation of diagnostic methods showed that parasitological diagnosis should still be the mainstay in diagnosis, with sensitivities for lymph node, bone marrow and spleen aspirates of 58%, 70% and 96%, respectively. Simple, cheap serological tests are needed. The direct agglutination test (DAT) had a sensitivity of 72%, specificity of 94%, positive predictive value of 78% and negative predictive value of 92%. As with other serological tests, the DAT cannot distinguish between active disease, subclinical infection or past infection. The introduction of freeze-dried antigen and control sera greatly improved the practicality and accuracy of the DAT in the field. An enzyme-linked immunosorbent assay using recombinant K39 antigen had higher sensitivity than DAT (93%). The polymerase chain reaction using peripheral blood gave a sensitivity of 70-93% and was more sensitive than microscopy of lymph node or bone marrow aspirates in patients with suspected VL. The leishmanin skin test (LST) was typically negative during active VL and converted to positive in c. 80% of patients 6 months after treatment. Immunological studies showed that both Th1 and Th2 cell responses could be demonstrated in lymph nodes from VL patients as evidenced by the presence of messenger ribonucleic acid for interleukin (IL)-10, interferon gamma and IL-2. Treatment of peripheral blood mononuclear cells from VL patients with IL-12 was found to drive the immune response toward a Th1 type response with the production of interferon gamma, indicating a potential therapeutic role for IL-12. VL responded well to treatment with sodium stibogluconate, which is still the first line drug at a dose of 20 mg/kg intravenously or intramuscularly per day for 15-30 d. Side effects and resistance were rare. Liposomal amphotericin B was effective, with few side effects. Control measures have not been implemented. Based on observations that VL does not occur in individuals who have a positive LST, probably because of previous cutaneous leishmaniasis, a vaccine containing heat-killed L. major promastigotes is currently undergoing a phase III trial. PMID:11370250

Zijlstra, E E; el-Hassan, A M

2001-04-01

41

Continental ice sheet altering north-south atmospheric teleconnection and implication on southern ocean ventilation  

NASA Astrophysics Data System (ADS)

Newly acquired marine proxy records indicate intensification of wind-driven upwelling in the Southern Ocean during the late Pleistocene glacial terminations. The cause of this variation, which has been linked to the meridional shift of the southern hemisphere westerlies, is uncertain. In this study, we hypothesize that the growth of the northern hemisphere ice sheet might contribute to increase in southern ocean ventilation during deglaciation. Beyond a certain threshold, continental ice sheet growth lead to a marked (~30%) strengthening of the southern ocean winds in the Pacific sector. Northern hemisphere cooling, e.g. Heinrich events, aids this strengthening. Simulations using an atmospheric generally circulation model coupled to a reduced gravity ocean model where the Last Glacial Maximum ice sheet thickness were successively increased from zero thickness to 100% suggest that this threshold occurs around 70-80% full height. The ice sheet topography results in southward displacement of the Pacific Intertropical Convergence Zone and weakening of June-July-August southern hemisphere Hadley circulation. Reduced angular momentum transport by Hadley circulation drives a stronger subpolar jet in the Pacific sector of the southern ocean that potentially intensify wind-driven upwelling and CO2 ventilation from the deep ocean. The scenario investigate here emphasize the importance of tropical circulation mediating the intimate coupling between the northern and southern high-latitude climate through atmospheric circulation. In light of recent late Pleistocene upwelling record, the altered north-south atmospheric teleconnection described here has implications on Antarctic deep water ventilation and ocean-atmosphere CO2 exchange on glacial-interglacial climate dynamics. If correct, our scenario offers a consistent explanation for the lead of the tropics and Antarctic temperatures, as well as CO2, to northern hemisphere deglaciation.

Lee, S.; Chiang, J. C.

2009-12-01

42

Orbital Radar Response of Near Surface Materials in Southern Egypt and Implications for Cenozoic History  

NASA Astrophysics Data System (ADS)

Although the existence of "trunk" and tributary drainage channels beneath the sand in the northeast Sahara has been known for two decades, data from the SIR-C mission continues to be useful in solving geologic problems and understanding the radar response from specific types of near surface materials. In the Kiseiba Oasis region of southwest Egypt, SIR-C data revealed a complex tributary pattern of varying brightness that indicated the presence of paleodrainage not noted in the field. The orbital imaging radar uniquely specified key areas for detailed field studies that were not apparent in visible wavelengths. Twenty-two trenches up to 3 m deep, hundreds of shallow pits, several auger holes, and ground penetrating radar reveal that this area has had a history of fluctuating climatic conditions responsible for excavation and enlargement of the local depression by fluvial erosion and preservation of relict surfaces by aeolian blanketing of sand sheet deposits. The resulting near-surface stratigraphy is a complex mixture of fluvial pebble lags in the subsurface and on the surface, where aeolian mixing and local transport have modified the original geometry. In L-band (23 cm wavelength) SIR-C data, a hierarchy of returned signal strength and geometric patterns enables us to predict the type of surface and near-surface materials, sequentially from shallow bedrock to subsurface and surficial lags to sand sheet-veneered weathered anhydrite. Integrating the pattern of sedimentary deposits with relict channels and interfluves enables a better understanding of the origin of the Kiseiba-Dungul depression and its Cenozoic history. What was once thought to be a continuous deposit of Eocene limestone from southern Egypt into northern Sudan is cast in doubt as even the most optimistic estimates of scarp retreat don't permit hundred's of kms of retreat to the present position. Instead, the E-W pattern of the depression, the relict hills, and fracture zones all suggest structural control and erosion patterns that started with N-S compression in the latest Cretaceous. A humid climate during the Tertiary aided fluvial dissection of the broken surface, with drainage leading to the north into the present Kharga depression. The drainage patterns of the Quaternary seen now in orbital radar result from remnants of large-scale structural patterns and Tertiary drainage, confused by alternating hyperarid and semiarid climatic cycles that inverted topography, protected former erosion surfaces, and reversed drainage.

Maxwell, T. A.; Grant, J. A.; Johnston, A. K.

2004-05-01

43

Current situation of tropical theileriosis in the Sudan.  

PubMed

Tropical theileriosis has long been recognized as a hindrance to the development of sound dairy industry in the Sudan and is a cause of major economic losses. Serological surveys indicated that Theileria annulata infection is widespread in the country but the disease mostly affects exotic dairy breeds and their crosses with indigenous breeds. The disease has recently been identified in Darfur and southern parts of Blue Nile State in dairy farms around large urban areas where it has never been detected before. These new introductions were accompanied by the establishment of Hyalomma anatolicum tick which is the main vector of the parasite in the Sudan. The disease is routinely diagnosed using microscopic examination of stained blood and lymph node biopsy smears. More advanced techniques are mainly used for research purposes. Tropical theileriosis in the Sudan is mainly controlled by using anti-theilerial drugs and acaricide application. It is recommended that live attenuated schizont vaccines developed from locally isolated T. annulata strains be used to control the disease. In addition, every care should be taken to prevent introduction of the disease into new areas. PMID:22565402

El Hussein, Abdelrahim M; Hassan, Shawgi M; Salih, Diaeldin A

2012-08-01

44

A molecular survey of cystic echinococcosis in Sudan.  

PubMed

A survey of cystic echinococcosis in livestock was conducted from May 2001 to July 2003 in central, western and southern Sudan. Hydatid cysts were present in 59% (466/779) of camels, 6% (299/4893) of cattle, 11% (1180/10,422) of sheep and 2% (106/5565) of goats, with little variation among different geographical areas. 532 of these cysts were examined by PCR and could be overwhelmingly (98.7%) allocated to Echinococcus canadensis G6/7 (all of 215 cysts from camels, 112 of 114 cysts from cattle, 134 of 138 cysts from sheep, and all of 65 cysts from goats); the genotype G6 was identified by sequencing 13 of these isolates. Only 2 cysts from cattle belonged to Echinococcus ortleppi. The mean number of cysts per infected animal was much higher in camels (5.1) than in the other species (1.0-1.3), and cyst fertility was higher in camels and cattle (74% and 77%) than in goats and sheep (31% and 19%). Fertile cysts from five human patients from hospitals in Khartoum and Juba belonged to E. canadensis (G6). This study confirms the predominance of the 'camel strain' in Sudan and the infectivity of this strain for humans. This is the first genetic characterization of human CE in Sudan. PMID:20138433

Omer, R A; Dinkel, A; Romig, T; Mackenstedt, U; Elnahas, A A; Aradaib, I E; Ahmed, M E; Elmalik, K H; Adam, A

2010-05-11

45

Agricultural fields, Khartoum, Sudan, Africa  

NASA Technical Reports Server (NTRS)

This herringbone pattern of irrigated agricultural fields near Khartoum, Sudan (14.5N, 33.5E) is very distinctive in both size and shape. The region contains thousands of these rectangular fields bounded by canals which carry water from both the White and Blue Nile Rivers. A crop rotation system is used so that some fields are in cotton, millit, sorghum or fallow to conserve moisture and control weeds and insects. See also STS049-96-003.

1992-01-01

46

Nile River, Khartoum, Sudan, Africa  

NASA Technical Reports Server (NTRS)

This view shows the confluence of the White Nile and the Blue Nile rivers to form the Nile River at Khartoum, the capital city of Sudan (15.5N, 32.5E). The White Nile comes from the south and drains the Sudd swamp and African Rift Valley while the Blue Nile comes from the southeast draining the Ethiopian highlands. The herringbone field patterns to the south of the city are agricultural fields where cotton is the main crop.

1983-01-01

47

Inventory management support systems for emergency humanitarian relief operations in South Sudan  

Microsoft Academic Search

Purpose – To develop and test three different inventory management strategies as applied to the complex emergency in south Sudan. Design\\/methodology\\/approach – Quantitative modeling, simulation, and statistics. Findings – This research identified critical system factors that contributed most significantly to inventory system performance, and identified strengths and weaknesses of each inventory management strategy. Research limitations\\/implications – This research represents a

Benita M. Beamon; Stephen A. Kotleba

2006-01-01

48

Environmental justice and regional inequality in southern California: implications for future research.  

PubMed

Environmental justice offers researchers new insights into the juncture of social inequality and public health and provides a framework for policy discussions on the impact of discrimination on the environmental health of diverse communities in the United States. Yet, causally linking the presence of potentially hazardous facilities or environmental pollution with adverse health effects is difficult, particularly in situations in which diverse populations are exposed to complex chemical mixtures. A community-academic research collaborative in southern California sought to address some of these methodological challenges by conducting environmental justice research that makes use of recent advances in air emissions inventories and air exposure modeling data. Results from several of our studies indicate that communities of color bear a disproportionate burden in the location of treatment, storage, and disposal facilities and Toxic Release Inventory facilities. Longitudinal analysis further suggests that facility siting in communities of color, not market-based "minority move-in," accounts for these disparities. The collaborative also investigated the health risk implications of outdoor air toxics exposures from mobile and stationary sources and found that race plays an explanatory role in predicting cancer risk distributions among populations in the region, even after controlling for other socioeconomic and demographic indicators. Although it is unclear whether study results from southern California can be meaningfully generalized to other regions in the United States, they do have implications for approaching future research in the realm of environmental justice. The authors propose a political economy and social inequality framework to guide future research that could better elucidate the origins of environmental inequality and reasons for its persistence. PMID:11929723

Morello-Frosch, Rachel; Pastor, Manuel; Porras, Carlos; Sadd, James

2002-04-01

49

Peace impact on health: population access to iodized salt in south Sudan in post-conflict period  

PubMed Central

Aim To determine the population access to salt/iodized salt during and after the armed conflict in south Sudan and to illustrate geographical variations in population consumption of iodized salt in south Sudan after the armed conflict. Methods The sources of data for the conflict period were the 2004 Toward a Baseline: Best Estimates of Social Indicators for Southern Sudan study report and the 2000 Multiple Indicators Cluster Survey, and for the post-conflict period the 2005 Sudan Household Health Survey (SHHS) data set. Results After peace agreement, population access to salt increased by 6.8% (Z?=?5.488, P?Sudan. Public health authorities in south Sudan need to establish quality monitoring and surveillance systems to track progress toward Universal Salt Iodization goal defined by the World Health Organization, United Nations Children’s Fund, and the International Council for the Control of Iodine Deficiency Disorders.

Gaffar, Abdelrahim Mutwakel; Mahfouz, Mohamed Salih

2011-01-01

50

Efficacy of chloroquine, sulphadoxine-pyrimethamine and amodiaquine for treatment of uncomplicated Plasmodium falciparum malaria in Kajo Keji county, Sudan  

Microsoft Academic Search

Summary To provide advice on the rational use of antimalarial drugs, Medecins Sans Frontieres conducted a randomized, an open label efficacy study in Kajo Keji, an area of high transmission of malaria in southern Sudan. The efficacy of chloroquine (CQ), sulphadoxine-pyrimethamine (SP) and amodiaquine (AQ) were measured in a 28-day in vivo study, with results corrected by PCR genotyping. Of

Elisa Stivanello; Philippe Cavailler; Francesco Cassano; Sabah Ahmed Omar; Daniel Kariuki; Jonathan Mwangi; Patrice Piola; Jean-Paul Guthmann

2004-01-01

51

Rift Valley Fever, Sudan, 2007 and 2010  

PubMed Central

To elucidate whether Rift Valley fever virus (RVFV) diversity in Sudan resulted from multiple introductions or from acquired changes over time from 1 introduction event, we generated complete genome sequences from RVFV strains detected during the 2007 and 2010 outbreaks. Phylogenetic analyses of small, medium, and large RNA segment sequences indicated several genetic RVFV variants were circulating in Sudan, which all grouped into Kenya-1 or Kenya-2 sublineages from the 2006–2008 eastern Africa epizootic. Bayesian analysis of sequence differences estimated that diversity among the 2007 and 2010 Sudan RVFV variants shared a most recent common ancestor circa 1996. The data suggest multiple introductions of RVFV into Sudan as part of sweeping epizootics from eastern Africa. The sequences indicate recent movement of RVFV and support the need for surveillance to recognize when and where RVFV circulates between epidemics, which can make data from prediction tools easier to interpret and preventive measures easier to direct toward high-risk areas.

Aradaib, Imadeldin E.; Erickson, Bobbie R.; Elageb, Rehab M.; Khristova, Marina L.; Carroll, Serena A.; Elkhidir, Isam M.; Karsany, Mubarak E.; Karrar, AbdelRahim E.; Elbashir, Mustafa I.

2013-01-01

52

The Ecology of the Southern California Bight: Implications for Water Quality Management.  

National Technical Information Service (NTIS)

The ecology of the coastal waters off southern California and the effects of man's activities, especially municipal wastewater discharge, on the marine environment are surveyed. Chapters discuss a perspective for considering the Southern California Bight;...

1973-01-01

53

Francisella tularensis Bacteremia: A Case Report from Sudan  

PubMed Central

Francisella tularensis is a highly virulent intracellular gram-negative bacterium. The organism is usually isolated from wild and domestic animals and invertebrate. Man gets infection by direct contact with those animals or their products but the most common mode of transmission is via arthropod vectors. The disease is endemic in North America, parts of Europe, and Asia but has never been reported in Africa. A 29-year old male living in a rural area of Southern Sudan has been maintained on continuous ambulatory peritoneal dialysis for two years. He presented to our center in May 2010 complaining of fever, dry cough, shortness of breath, and abdominal discomfort for four days. He was very ill, pale, and dehydrated. There were enlarged tender submandibular lymph nodes, but no mouth ulcers or other palpable lymph nodes. Peritonitis was excluded by effluent white blood cell count and culture. Empiric antibiotic treatment with ceftriaxon, and ciprofloxacin was started. Gram-negative coccobacilli were isolated by blood culture. The organism was identified as Francisella tularensis. We started him on a ten-day course of gentamicin after which he improved. This is, to the best of our knowledge, the first reported case of bacteremia caused by Francisella tularensis in Sudan.

Mohamed, Salma E. R.; Mubarak, Aymun I.; Alfarooq, Lamia O.

2012-01-01

54

Structural and Sedimentological Development of Pahrump Basin, Southern Nevada with Implications for Seismic Hazards  

NASA Astrophysics Data System (ADS)

The purpose of this study is to (1) document potentially active faults and estimate possible earthquake magnitudes, (2) document and analyze sedimentation in a basin controlled by strike-slip and oblique faults, and (3) consider implications on regional development using Pahrump Valley, southern Nevada as a case study. The 2.5 million people living within the region would be significantly impacted by a major earthquake generated in the Valley. With an ever increasing population, the need for evaluation of seismic risk is becoming more important for land use planning in southern Nevada. Using data analysis of well logs, geophysical measurements, surface data from air photos, maps, and field observations, it is possible to document the 3D architecture of the basin-fill sediments and basin structure through abrupt changes in sedimentary facies. 3D modeling of the lithology and depositional environments of shallow basin fill improves the understanding of fault location, type, offset, and surface rupture length. Pahrump Valley is flanked by two documented Neogene (Quaternary) fault systems. The west side is dominated by the Stateline Fault zone, which is a continuous NW-striking right-lateral strike-slip fault zone extending 200 km from Mesquite Valley to Amargosa Valley, Nevada. In Pahrump Valley no fault scarp is present. The eastern side is bordered by the West Spring Mountains fault, which is a N-striking W-dipping normal fault with a right-lateral oblique component. The fault has a large scarp which is visible along the northeastern and east-central Valley border and smaller discontinuous scarps in the south. The 11-km-long central segment contains scarps up to 9.4 m high. On the basis of scarp profiles, the youngest event is estimated to be Pleistocene or early Holocene in age with a maximum fault displacement estimated at 1.8-2.0 m, which suggests an event of M 6.9. 3D basin models, derived from well log lithology, depict the locations of fault surfaces by showing abrupt changes in units and unit offsets among multiple wells. The lithologic data augmented with surface investigations and seismic data show a depositional environment dominated by alluvial deposits of coarse material (gravel and sand) and playa sediments (clay and soils) that interfinger. The playa sediments in the west valley exhibit right-lateral displacement of 10 km consistent with the Stateline fault zone.

Carter, J.; Taylor, W. J.; Luke, B.

2008-12-01

55

Paleoseismology of the southern Panamint Valley fault: Implications for regional earthquake occurrence and seismic hazard in southern California  

NASA Astrophysics Data System (ADS)

data from the southern Panamint Valley fault (PVF) reveal evidence of at least four surface ruptures during late Holocene time (0.33-0.48 ka, 0.9-3.0 ka, 3.3-3.6 ka, and >4.1 ka). These paleo-earthquake ages indicate that the southern PVF has ruptured at least once and possibly twice during the ongoing (?1.5 ka) seismic cluster in the Mojave section of the eastern California shear zone (ECSZ). The most recent event (MRE) on the PVF is also similar in age to the 1872 Owens Valley earthquake and the geomorphically youthful MRE on the Death Valley fault. The timing of the three oldest events at our site shows that the PVF ruptured at least once and possibly thrice during the well-defined 2-5 ka seismic lull in the Mojave section of the ECSZ. Interestingly, the 3.3-3.6 ka age of Event 3 overlaps with the 3.3-3.8 ka age of the penultimate (i.e., pre-1872) rupture on the central Owens Valley fault. These new PVF data support the notion that earthquake occurrence in the ECSZ may be spatially and temporally complex, with earthquake clusters occurring in different regions at different times. Coulomb failure function modeling of the Panamint Valley and Garlock faults reveals significant stress interactions between these two faults that may influence future earthquake occurrence. Specifically, our models suggest a possible rupture sequence whereby an event on the southern Panamint Valley fault can lead to the potential triggering of an event on the Garlock fault, which in turn could trigger the Mojave section of the San Andreas Fault.

McAuliffe, Lee J.; Dolan, James F.; Kirby, Eric; Rollins, Chris; Haravitch, Ben; Alm, Steve; Rittenour, Tammy M.

2013-09-01

56

Serosurvey of Prevalence of Human Immunodeficiency Virus amongst High Risk Groups in Port Sudan, Sudan. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

During October, 1987, 593 sera were collected from risk groups in Sudan's only major deepwater port, Port Sudan. The risk groups included prostitutes, lorry drivers and prisoners. A large proportion of the study participants practiced high risk behavior w...

J. P. Burans M. McCarthy S. M. El Tayeb A. EL Tigani J. George

1990-01-01

57

UPLC-ESI-MS\\/MS analysis of Sudan dyes and Para Red in food  

Microsoft Academic Search

An analytical method for the simultaneous determination of Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B and Sudan IV) and Para Red in food by ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS\\/MS) was developed. Samples were extracted with acetonitrile, and water added into the extract. The supernatant was analysed by UPLC-MS\\/MS after refrigeration and

C. Li; Y. L. Wu; J. Z. Shen

2010-01-01

58

Genesis of some calcretes in the southern Yilgarn Craton, Western Australia: Implications for mineral exploration  

Microsoft Academic Search

Calcrete is extensively distributed in the semi?arid and arid regions of the southern Yilgarn Craton of Western Australia. Two general types are recognised, groundwater and pedogenic calcretes; a model for the genesis of the latter is proposed, based on detailed studies in two regions (Mt Gibson and Kalgoorlie) in the southern Yilgarn Craton. At Mt Gibson, calcrete is largely restricted

R. R. Anand; C. Phang; J. E. Wildman; M. J. Lintern

1997-01-01

59

The relationship between Pacific Decadal and Southern Oscillations: Implications for the climate of northwestern Baja California  

Microsoft Academic Search

The relationship between the Southern Oscillation (SO) and the Pacific Decadal Oscillation (PDO) is stud - ied by means of forced and secondary forecast models of the PDO. These models are constructed with the same indices frequently associated to different aspects of the climate of northwestern Baja California, namely the Southern Oscillation Index and the Pacific Decadal Oscillation Index (SOI

E. G. Pavia

2009-01-01

60

An ultrasensitive and selective fluorescence assay for Sudan I and III against the influence of Sudan II and IV.  

PubMed

We report on an ultrasensitive and selective fluorescence assay for Sudan I and III against the influence of Sudan II and IV based on ligand exchange mechanism. Calcein as a fluorescence indicator and Sudan I-IV as model analytes were employed to investigate the analytical feature of this assay platform. Results show that the fluorescence of calcein can be efficiently quenched by Cu(II). When the ligand exchange reaction proceeds, calcein is deprived of Cu(II) by Sudan I and III, resulting in the fluorescence recovery of calcein. However, the ligand exchange reaction does not happen in the presence of Sudan II or IV due to the 2-methyl steric effects, which is favorable for selective determination of Sudan I and III against the influence of Sudan II and IV. It was found that the fluorescence enhancement efficiency (FEE) against the concentration of Sudan (c(Sudan), nmol L?¹) shows a linear relationship. The calibration equations are FEE(Sudan I)=0.0032 c(Sudan I)-0.02613, and FEE(Sudan III)=0.0033 c(Sudan III)-0.02467 over the corresponding linear range of 11.25-2078.29 and 9.44-1035.78 nmol L?¹ with the correlation coefficients (R(2)) of 0.9984 and 0.9955, respectively. And the detection limits (3?/slope) are calculated to be 211.3 and 208.5 pmol L?¹ for Sudan I and III, respectively, showing ultralow detection limit. The Sudan dye in a commercial chilli powder sample was assayed with satisfactory results. PMID:23202343

Huang, Sheng Tian; Yang, Ling Feng; Li, Nian Bing; Luo, Hong Qun

2013-04-15

61

Evidence for genetic differentiation at the microgeographic scale in Phlebotomus papatasi populations from Sudan  

PubMed Central

Background Cutaneous Leishmaniasis (CL) is endemic in Sudan. It is caused by Leishmania major parasites and transmitted by Phlebotomus papatasi sandflies. Recently, uncommon clinical manifestations of CL have been reported. Moreover, L. donovani parasites that cause Visceral Leishmaniasis (VL) have been isolated from CL lesions of some patients who contracted the disease in Khartoum State, Central Sudan with no history of travelling to VL endemic sites on south-eastern Sudan. Because different clinical manifestations and the parasite behaviour could be related to genetic differentiation, or even sub-structuring within sandfly vector populations, a population genetic study was conducted on P. papatasi populations collected from different localities in Khartoum State known for their uncommon CL cases and characterized by contrasting environmental conditions. Methods A set of seven microsatellite loci was used to investigate the population structure of P. papatasi samples collected from different localities in Khartoum State, Central Sudan. Populations from Kassala State, Eastern Sudan and Egypt were also included in the analyses as outgroups. The level of genetic diversity and genetic differentiation among natural populations of P. papatasi was determined using FST statistics and Bayesian assignments. Results Genetic analyses revealed significant genetic differentiation (FST) between the Sudanese and the Egyptian populations. Within the Sudanese P. papatasi populations, one population from Gerif West, Khartoum State, exhibited significant genetic differentiation from all other populations including those collected as near as 22 km. Conclusion The significant genetic differentiation of Gerif West P. papatasi population from other Sudanese populations may have important implication for the epidemiology of leishmaniasis in Khartoum State and needs to be further investigated. Primarily, it could be linked to the unique location of Gerif West which is confined by the River Nile and its tributaries that may act as a natural barrier for gene flow between this site and the other rural sites. The observed high migration rates and lack of genetic differentiation among the other P. papatasi populations could be attributed to the continuous human and cattle movement between these localities.

2012-01-01

62

Production of the polyclonal antibody against Sudan 3 and Immunoassay of Sudan dyes in food samples.  

PubMed

In this study, 4-aminophenylacetic acid was covalently coupled to aniline to synthesize an intermediate hapten and the intermediate hapten was coupled to ?-naphthol to synthesize a tentative hapten of Sudan 3. The hapten was coupled to bovine serum albumin as the immunogen to produce the polyclonal antibody. The obtained antibody was highly specific to Sudan 3, Sudan 1, and Para red, but showed relative low binding ability to Sudan 2, Sudan 4, and Sudan red G. After evaluation of different coating antigens, a heterologous indirect competitive immunoassay was developed to multidetermine the six red dyes in food samples. The cross reactivities to the six analytes were in a range of 21-105%, and the limits of detection were in a range of 0.1-0.8 ng/mL depending on the compound. Intra- and interassay recoveries from the standard fortified blank samples were in a range of 74.5-96.3% with coefficients of variation lower than 15.1%. PMID:22329681

Qi, Yong Hua; Shan, Wen Chong; Liu, Yan Zheng; Zhang, Yu Jie; Wang, Jian Ping

2012-03-01

63

Production of the monoclonal antibody against Sudan 2 for immunoassay of Sudan dyes in egg.  

PubMed

Many methods have been reported to determine the residues of Sudan dyes in food samples. Among the reported methods, enzyme-linked immunosorbent assay (ELISA) was a frequently used practical screen tool. In this study, a novel hapten of Sudan 2 was synthesized by coupling 4-amino-3-methylbenzoic acid to ?-naphthol, and the monoclonal antibody against Sudan 2 was produced. The obtained antibody can recognize Sudan 1, 2, 3, and 4, Sudan red G, and Para red simultaneously. After evaluation of different coating antigens, a heterologous indirect competitive ELISA was then developed to determine the six Sudan dyes in egg. The cross-reactivities for the six analytes were in a range of 63% to 100%, and the limits of detection were in a range of 0.2 to 0.5 ng/g, depending on the compound. Intra- and interassay recoveries from the standard fortified blank eggs were in a range of 71.7% to 97.6% with coefficients of variation lower than 17.1%. PMID:22327048

Liu, Jing; Zhang, Huicai; Zhang, Dongsheng; Gao, Feng; Wang, Jianping

2012-04-15

64

International Religious Freedom Report: Sudan, April 2002.  

National Technical Information Service (NTIS)

The U.S. Commission on International Religious Freedom, in its past two annual reports, found the government of Sudan to be the world's most violent abuser of the right to freedom of religion and belief. The Commission also found that religion is a major ...

2002-01-01

65

Aetiology of Oral Cancer in the Sudan  

PubMed Central

ABSTRACT Objectives To review the studied risk factors that linked to aetiology of oral cancer in the Sudan. There have been numerous reports in the increase in the incidence of oral cancer from various parts of the world. A recent trend for a rising incidence of oral cancer, with the absence of the well established risk factors, has raised concern. Although, there are inconsistent data on incidence and demographical factors, studies suggest that the physiologic response to risk factors by men and women vary in different populations. Material and Methods This review principally examines 33 publications devoted to aetiology of oral cancer in the Sudan, in addition to some risk factors that are commonly practiced in the Sudan. Results Several studies examining risk factors for oral cancer include tobacco use (Smoked and Smokeless), alcohol consumption, occupational risk, familial risk, immune deficits, virus infection and genetic factors. Conclusions Toombak use and infection with high risk Human Papilloma Virus (HPV) were extensively investigated and linked to the aetiology of oral cancer in Sudan.

2013-01-01

66

Sudan dyes: are they dangerous for human health?  

PubMed

Azo and diazo compounds include Sudan dyes, which were widely used in industry. Although they are not permitted in food, they had been found contaminating different food products and their presence is investigated regularly (since 2003) in these products. Sudan III, as well as Sudan Black B, was included in different laboratory techniques for tissue ceroid and lipofucsin analysis and blood-cell staining. Also, Sudan Black B has been recently included in in vivo evaluations in human beings (through oral intake), and Sudan III is still allowed in cosmetics. These azo dyes were metabolized to possible carcinogenic colorless amines, both in the liver of mammalians and by the micro flora present in human skin and the gastrointestinal tract. Both human and laboratory animal cytochrome P450s (CYPs) were able to oxidize Sudan I, whereas Sudan III modified CYP activities. In vitro genotoxic effects were reported for Sudan I, and some DNA adducts formed through exposure to its metabolites were identified. Sudan I was also found to be carcinogenic in the rat, but not in the mouse. The aim of the present review is to put together the most relevant information concerning Sudan dye uses and toxicity to provide some tools for the identification of the risk they represent for human health. PMID:22947042

Fonovich, Teresa M

2013-07-01

67

Tectonic implications of the microearthquake seismicity and fault plane solutions in southern Peru  

NASA Technical Reports Server (NTRS)

Because the contortion in the seismic zone in southern Peru is aligned approximately parallel to the direction of relative plate motion, rather than perpendicular to the coast of Peru, the position of the contortion need not migrate with respect to the overriding South American plate as the Nazca plate subducts beneath it, and the flow in the surrounding asthenosphere could be in a steady state. In addition, the position of the contortion defines the northern boundary of the volcanic arc in southern Peru. The inference that a wedge of asthenospheric material must overlie the downgoing slab for subduction-related volcanism to occur is thereby strengthened.

Grange, F.; Hatzfeld, D.; Cunningham, P.; Molnar, P.; Roecker, S. W.; Suarez, G.; Rodrigues, A.; Ocola, L.

1984-01-01

68

Late Cretaceous and Eocene volcanism in the southern Line Islands and implications for hotspot theory  

Microsoft Academic Search

Rocks dredged from a seamount 100 km northwest of Caroline Island, at the southern end of the Line Islands chain, contain Late Cretaceous fossils associated with volcanic debris. This association is evidence for the existence of a reef-bearing volcanic edifice with a minimum age of Late Cretaceous, 70 to 75 m.y., near Caroline Island. With the discovery of this seamount,

Janet A. Haggerty; Seymour O. Schlanger; Isabella Premoli Silva

1982-01-01

69

The Cotonou Agreement and its Implications for the Regional Trade Agenda in Eastern and Southern Africa  

Microsoft Academic Search

Subregional trade arrangements (RTAs) in Eastern and Southern Africa have proliferated in the past 10 to 15 years. The small size of most of the countries in the region, some of which are landlocked, and the security needs in the post independence period largely explain the rapid expansion. These arrangements are characterized by multiple and overlapping memberships, complex structures, and

Manuel de la Rocha

2003-01-01

70

Characteristics of the low energy seismicity of central Apulia (southern Italy) and hazard implications  

Microsoft Academic Search

The central part of the Apulia region, in southern Italy, has been generally considered practically free from significant level of seismicity, but historical documentation, geological indicators and recent instrumental observations suggest that the activity of local minor tectonic structures could have been “masked” (and partly also induced) by that of major seismogenic structures located in the neighbouring regions. A revision

V. Del Gaudio; P. Pierri; G. Calcagnile; N. Venisti

2005-01-01

71

Subsidence and thermal history of Southern Oklahoma aulacogen: implications for petroleum exploration  

Microsoft Academic Search

Reconstructed subsidence curves and the thermal history of the Southern Oklahoma aulacogen support the concept of thermally controlled isostatic subsidence for the formation of the basin and indicate the significance of this concept for petroleum exploration. Two mechanisms - initial elastic flexure, followed by detachment and differential subsidence of the aulacogen - are inferred from the subsidence curves. Two methods

Feinstein

1981-01-01

72

Late Cenozoic landscape development and its tectonic implications for the Guadalhorce valley near Álora (Southern Spain)  

Microsoft Academic Search

Landscape evolution is the result of a variety of geomorphological processes and their controls in time. In southern Spain tectonics, climate and sea-level fluctuations have been some of the main variables controlling long-term (Late Cenozoic) landscape evolution. In the Guadalhorce valley, Malaga, geomorphological reconstructions can be undertaken using sedimentary evidence from marine and fluvial deposits as well as erosional evidence

J. M. Schoorl; A. Veldkamp

2003-01-01

73

Lithospheric thickness beneath the southern Kenya Rift: implications from basalt geochemistry  

Microsoft Academic Search

Geochemical data are reported for samples from the flanks and floor of the southern Kenya Rift Valley in the Lake Magadi area, and from two central volcanoes located within the rift valley. Rift lavas include samples of Singaraini and Ol Tepesi basalts on the eastern flank, Kirikiti basalts from the western flank, and plateau trachytes from the rift valley floor.

Anton P. Roex; Andreas Späth; Robert E. Zartman

2001-01-01

74

The maxillary sinus of Paradolichopithecus sushkini (late Pliocene, southern Tajikistan) and its phyletic implications  

Microsoft Academic Search

Paradolichopithecus sushkini is a large fossil cercopithecine from the late Pliocene discovered at Kuruk-Say, southern Tajikistan. Despite its rather long face and large size, many authorities regard Paradolichopithecus not as a baboon, but as a large macaque, mainly based on the cranial morphology of European specimens. Among Old World monkeys, macaques are the only species that possess a maxillary sinus.

Takeshi D. Nishimura; Masanaru Takai; Evgeny N. Maschenko

2007-01-01

75

Late Neogene loess deposition in southern Tarim Basin: tectonic and palaeoenvironmental implications  

Microsoft Academic Search

Uplift of the Tibetan Plateau during the late Cainozoic resulted in a thick apron of molassic sediments along the northern piedmonts of the Kunlun and Altyn Mountains in the southern Tarim Basin. Early Neogene sediments are characterised by sandstone, siltstone and red mudstone, representing floodplain to distal alluvial fan environments. The Early Pliocene Artux Formation consists of medium-grained sandstone and

Hongbo Zheng; Chris McA Powell; Katherine Butcher; Junji Cao

2003-01-01

76

Phylogeography and Spatial Genetic Structure of the Southern Torrent Salamander: Implications for Conservation and Management  

Microsoft Academic Search

The Southern torrent salamander (Rhyacotriton variegatus) was recently found not warranted for listing under the US Endan- gered Species Act due to lack of information regarding population fragmentation and gene flow. Found in small-order streams associated with late-successional coniferous forests of the US Pacific Northwest, threats to their persistence include distur- bance related to timber harvest activities. We conducted a

MARK P. MILLER; S. M. Haig; R. STEVEN WAGNER

2006-01-01

77

Paleomagnetic Evidence For A 80 Ccw Rotation of The Apenninic Platform (southern Apennines): Geodynamic Implications  

NASA Astrophysics Data System (ADS)

The tectonic evolution of the Apennine belt / southern Tyrrhenian Sea system is addressed through a paleomagnetic study of Lias to Langhian sediments from the Apenninic carbonate platform (southern Apennines). Paleomagnetic data from 21 sites document a regional-scale 80 counterclockwise (CCW) rotation occurring after Langhian. Since previous studies of the Plio-Pleistocene clays spread over the oro- genic belt had previously documented a ~20 CCW rotation, we conclude that the southern Apennines rotated by 60 during Middle-Late Miocene. Our data prove that the southeastward drift of Calabrian block (and synchronous spreading of the south- ern Tyrrhenian Sea) induced saloon-door like deformation of the southern Apennines and Sicily which underwent similar-magnitude (although opposite in sign) orogenic rotations. Our paleogeographic reconstruction shows that at 15 Ma (Late Langhian) the Alpine-Apennine belt collided with a NNE-oriented carbonate platform corridor surrounded by oceanic basins. We speculate that both the end of the Corsica-Sardinia rotation and the eastward jump of the locus of back-arc extension (from the Liguro- Provençal to the Tyrrhenian Sea) may have been consequences of this event.

Gattacceca, J.; Speranza, F.

78

Faunal Characteristics of the Southern Rocky Mountains of New Mexico: Implications for Biodiversity Analysis and Assessment.  

National Technical Information Service (NTIS)

Our study focused on the Southern Rocky Mountains of New Mexico and included the San Juan the Sangre de Cristo, and the Jemez Mountains. Across this region, we quantified patterns of species richness and faunal diversity based on reported and predicted oc...

R. R. Cook C. H. Flather K. R. Wilson

2000-01-01

79

Invasion of tallow tree into southern US forests: influencing factors and implications for mitigation  

Microsoft Academic Search

We identify species-environment relationships to predict the occurrence of Chinese tallow (Triadica sebifera (L.) Small) on forestlands in the southern US, where it has emerged as the most pervading, stand-replacing, alien tree spe- cies. Tallow invasions are more likely to be observed on low and flat lands, areas adjacent to water and roadways, sites re- cently harvested or disturbed, younger

Jianbang Gan; James H. Miller; Hsiaohsuan Wang; John W. Taylor Jr

2009-01-01

80

The thermal responses of rock art pigments: Implications for rock art weathering in southern Africa  

Microsoft Academic Search

The San rock art of southern Africa is an international heritage subject to degradation and loss resulting from weathering. The paintings occur within rock shelters, where many are exposed to direct solar radiation for varying periods, rather than occurring in dark caves. As part of a study on the factors thought to be impacting weathering, data were collected pertaining to

Kevin Hall; Ian Meiklejohn; Joselito Arocena

2007-01-01

81

Safety and effectiveness of first line eflornithine for Trypanosoma brucei gambiense sleeping sickness in Sudan: cohort study  

Microsoft Academic Search

Objective To assess the safety and effectiveness of eflornithine as first line treatment for human African trypanosomiasis.Design Cohort study.Setting Control programme in Ibba, southern Sudan.Participants 1055 adults and children newly diagnosed with second stage disease in a 16 month period.Main outcome measures Deaths, severe drug reactions, and cure at 24 months.Results 1055 patients received eflornithine for 14 days (400 mg\\/kg\\/day

Gerardo Priotto; Loretxu Pinoges; Isaac Badi Fursa; Barbara Burke; Nathalie Nicolay; Guillaume Grillet; Cathy Hewison; Manica Balasegaram

2008-01-01

82

Antiretroviral adherence interventions in Southern Africa: implications for using HIV treatments for prevention.  

PubMed

There is concern that the expansion of ART (antiretroviral treatment) programmes to incorporate the use of treatment as prevention (TasP) may be associated with low levels of adherence and retention in care, resulting in the increased spread of drug-resistant HIV. We review research published over the past year that reports on interventions to improve adherence and retention in care in Southern Africa, and discuss these in terms of their potential to support the expansion of ART programmes for TasP. We found eight articles published since January 2012, seven of which were from South Africa. The papers describe innovative models for ART care and adherence support, some of which have the potential to facilitate the ongoing scale- up of treatment programmes for increased coverage and TasP. The extent to which interventions from South Africa can be effectively implemented in other, lower-resource Southern African countries is unclear. PMID:24390683

Dewing, Sarah; Mathews, Cathy; Fatti, Geoffrey; Grimwood, Ashraf; Boulle, Andrew

2014-03-01

83

Savanna burning and convective mixing in southern Africa - Implications for CO emissions and transport  

NASA Technical Reports Server (NTRS)

Atmospheric data from both remote and direct measurements were used to compute the carbon monoxide (CO) emissions and mass transport from Africa south of the equator. The Measurement of Air Pollution from Satellites (MAPS) experiment flew on the Space Shuttle during October 5-13, 1984; the highest CO mixing ratios from the entire mission were measured over southern Africa. In addition to the MAPS data, surface CO mixing ratios were measured in the boundary layer at Cape Point, South Africa. A calibration factor for the remote MAPS CO measurements was determined by computing the ratio of the surface measurements from Cape Point during unpolluted periods to coincident MAPS measurements. The adjusted MAPS CO data were then used to compute the mass flux of CO from biomass burning in southern Africa during the MAPS mission. The transport calculations were compared to the estimated CO emissions from biomass burning to examine the efficiency in which the continental tropical clouds redistribute CO in the troposphere.

Connors, Vickie S.; Cahoon, Donald R., Jr.; Reichle, Henry G.; Brunke, Ernst-Gunther; Garstang, Michael; Seiler, Wolfgang; Scheel, H. E.

1991-01-01

84

Morphometric variability in the diatom Fragilariopsis kerguelensis: Implications for Southern Ocean paleoceanography  

NASA Astrophysics Data System (ADS)

Diatoms play a central role in the ecosystem of the Southern Ocean, where they represent the main producers and carriers of organic carbon and dissolved silicon towards the deep ocean. Variability in space and time of the size of the most abundant species ( Fragilariopsis kerguelensis) may directly impact the way this ecosystem functions, and also affect the nutrient balance of the global ocean, as important water masses (e.g. the Antarctic Intermediate Water) get their nutrient signature in this area. We used a biometric approach and analyzed the size variability of F. kerguelensis valves in sixty-four surface sediment samples from the Southern Ocean, in sediment trap samples from a mooring (Site PF3) at the Antarctic Polar Front (APF), and along a nearby piston core (PS1654-2). The average length and valve area of F. kerguelensis displayed a distinct increase in the proximity of the APF, and lower values to the north and south of it, and also changed markedly over seasonal cycles, as diatom blooms and nutrient availability waxe and wane. The last glacial to interglacial transition also witnesses important changes in the general shape and valve size of F. kerguelensis, with specimens from glacial intervals being ca. 30% larger than their interglacial counterparts (195 versus 150 ?m 2 valve area). A sharp peak in average area and a very specific valve morphology correspond to the first signs of deglaciation and concurring SST (Sea Surface Temperature) increase and sea-ice retreat. The latter, together with melting icebergs, may have contributed dissolved iron to surface waters. The highest average sizes during glacial intervals are higher than what found anywhere in the Southern Ocean today. The newly proposed proxy (valve area and shape of F. kerguelensis) may thus prove useful for the reconstruction of the past position and nutrient characteristics of the APF and "opal belt", a region characterized by high production and export of biogenic silica, in a particularly sensitive and dynamic area such as the Southern Ocean.

Cortese, G.; Gersonde, R.

2007-05-01

85

Cordierite gneisses of southern Kerala, India: petrology, fluid inclusions and implications for crustal uplift history  

Microsoft Academic Search

The cordierite-bearing gneisses occurring as elongate patches in an 8- to 10-km-wide zone along the Achankovil fault-lineament at the northern margin of the southern Kerala crustal segment represent an important lithological unit in the Archaean granulite terrane of south India. The textural relationships in these rocks are consistent with the following main reactions: (1) garnet+quartz=cordierite+hypersthene; (2) garnet+sillimanite+quartz=cordierite; (3) hypersthene+sillimanite+quartz=cordierite; (4)

M. Santosh

1987-01-01

86

Age and origin of cold climate landforms from the Eastern Cape Drakensberg, southern Africa: palaeoclimatic implications  

NASA Astrophysics Data System (ADS)

Reliable dating is crucial for resolving the nature and timing of cold events in southern Africa and the associated cold climate landforms produced. Evidence for glaciation has been proposed for the Eastern Cape Drakensberg, based on the identification of moraines that were presumed to be of last glacial maximum age. Temperature depressions of 10-17°C have been proposed for this region, based on the presence of these moraines (Lewis and Illgner, 2001) and the identification of a relict rock glacier. Such large temperature depressions are, however, unsupported by other palaeoclimatic proxies in southern Africa. Debate regarding the occurrence of glaciation in southern Africa has been ongoing for several decades. There is good evidence for small-scale glaciation during the last glacial cycle in Lesotho, at elevations exceeding 3000 m a.s.l., but these sites are more than 1000 m higher in elevation than those identified in the Eastern Cape, and suggest a temperature depression of only ~6°C and a change to a winter dominated precipitation regime during the last glacial cycle. This paper presents preliminary cosmogenic nuclide exposure ages for the Eastern Cape 'moraines' and a periglacial blockstream in this region. We discuss potential alternative interpretations for the formation of the landforms and suggest that glaciers were absent in the Eastern Cape Drakensberg during the last glacial period. However, there is widespread evidence for periglacial activity down to an elevation of ~1700 m a.s.l., as illustrated by extensive blockstreams, stone garlands and solifluction deposits. These periglacial deposits suggest that the climate was much colder (~6ºC) during the last glacial cycle, in keeping with other proxy records, but not cold enough to initiate or sustain glaciers at low elevations. References Lewis C. A., Illgner, P. M., 2001. Late Quaternary glaciation in Southern Africa: moraine ridges and glacial deposits at Mount Enterprise in the Drakensberg of the Eastern Cape Province, South Africa. Journal of Quaternary Science 16, 365-374.

Mills, Stephanie C.; Barrows, Timothy T.; Fifield, L. Keith

2014-05-01

87

Predator abundance in relation to small game management in southern Portugal: conservation implications  

Microsoft Academic Search

The interaction between hunting interests and legally protected predators is often a contentious conservation problem, requiring\\u000a detailed understanding of predator responses to game management. This issue was addressed in southern Portugal in a treatment-control\\u000a natural experiment, whereby the abundances of small game, corvids, birds of prey and carnivores were compared in 12 game estates\\u000a (>500 ha) and 12 matching areas with

Pedro Beja; Luís Gordinho; Luís Reino; Filipa Loureiro; Margarida Santos-Reis; Rui Borralho

2009-01-01

88

Dynamics of Southern rice black-streaked dwarf virus in rice and implication for virus acquisition.  

PubMed

A novel viral disease of rice caused by Southern rice black-streaked dwarf virus (SRBSDV) has spread throughout East and Southeast Asia since the mid-2000s. Outbreaks of this viral disease occur yearly in southern parts of Japan concurrently with overseas migration of the planthopper vector Sogatella furcifera from southern China during the rainy season (from late June to early July). We examined the dynamics (changes in titer and localization) of SRBSDV on rice using reverse-transcription real-time polymerase chain reaction and determined the relationship between virus titer in plants and virus acquisition by S. furcifera. Under a constant temperature of 27°C, a substantial increase of SRBSDV titer in the leaf sheath together with typical symptoms (stunted growth and twisting of leaf tips) was observed at 20 days after the end of a 7-day exposure of viruliferous S. furcifera. Approximately 40% of S. furcifera acquired SRBSDV through feeding for 5 days on rice plants that were infected following exposure to viruliferous vectors for 10 to 15 days. These results suggest that rice infected by S. furcifera can be a source of SRBSDV before the next generation of S. furcifera emerges. PMID:23301813

Matsukura, Keiichiro; Towata, Tomomi; Sakai, Junichi; Onuki, Masatoshi; Okuda, Mitsuru; Matsumura, Masaya

2013-05-01

89

Forest to agriculture conversion in southern Belize: Implications for migrant land birds  

USGS Publications Warehouse

Central America offers a suite of neotropical habitats vital to overwintering migrant land birds. The recent decline of many forest dwelling avian migrants is believed to be related in part to neotropical deforestation and land use change. However, spatio-temporal trends in neotropical habitat availability and avian migrant habitat use are largely unknown. Such information is needed to assess the impact of agriculture conversion on migrant land birds. In response, the USDI Fish and Wildlife Service and the University of Maine began a cooperative study in 1988 which applies remote sensing and field surveys to determine current habitat availability and avian migrant habitat use. Study sites include areas in Belize, Costa Rica, Guatemala and southern Mexico. Visual assessment of Landsat TM imagery indicates southern Belize forests are fragmented by various agricultural systems. Shifting agriculture is predominant in some areas, while permanent agriculture (citrus and mixed animal crops) is the primary system in others. This poster focuses on efforts to monitor forest to agriculture conversion in southern Belize using remote sensing, field surveys and GIS techniques. Procedures and avian migrant use of habitat are summarized.

Spruce, J.P.; Dowell, B.A.; Robbins, C.S.; Sader, S.A.

1993-01-01

90

Estimating diaphyseal length from fragmentary subadult skeletal remains: implications for palaeodemographic reconstructions of a southern Ontario ossuary.  

PubMed

Fragmentary skeletal remains are a significant problem for osteologists attempting to reconstruct individuals or populations. This problem is further aggravated by sites yielding commingled remains, such as are recovered from the large protohistoric and historic ossuaries from southern Ontario, for which individual methods of age estimation and sex determination cannot be used concurrently. While some attention has been given to the estimation of long bone length from fragmentary, adult remains, little attention has been given to the equally important problem of fragmentary long bones in subadult assemblages. Analysis of data on diaphyseal length is a crucial aspect of reconstructing subadult palaeodemographic profiles, particularly for ossuary collections where dental remains are not associated with individuals and are often less represented than long bones. Such analysis also aids in the assessment of conditions of past population health. This study reports the results of several regression techniques used to estimate diaphyseal length from shaft-end breadths. Data collected from two southern Ontario ossuary samples were compiled to calculate the regression equations. Reliability of these equations and implications for palaeodemographic profiles are discussed. PMID:8798992

Hoppa, R D; Gruspier, K L

1996-07-01

91

Trends in the deep Southern Ocean (1958-2010): Implications for Antarctic Bottom Water properties and volume export  

NASA Astrophysics Data System (ADS)

Regional formation of deep and bottom water masses around the Antarctic continental shelf is one of the most important processes contributing to variability of the global meridional overturning circulation deep cell. Southern Ocean hydrographic data collected during the years 1958-2010 indicate that dense shelf waters cooled and freshened during that period. In the surrounding open ocean, Antarctic Bottom Water (AABW) warmed, with no evidence of salinity change. As a result of source-water property changes, AABW exported from the Southern Ocean to the deep world ocean became lighter over the period analyzed. The average rate of density change within the areas that experienced statistically significant change was -0.0019 kg m-3 yr-1. For the last 20 years of the analysis, a negative AABW volume anomaly (relative to the half-century average, 1958-2010) was indicated, possibly due to production of a lighter AABW variety or to changes in formation rates. Over the entire five decades, the upper isopycnal of the AABW layer deepened at a rate of -8.1 m yr-1. Changes in fundamental hydrographic properties such as these can have important implications for long-term global ocean circulation and climate.

Azaneu, Marina; Kerr, Rodrigo; Mata, Mauricio M.; Garcia, Carlos A. E.

2013-09-01

92

Three-dimensional lithospheric electrical structure of Southern Granulite Terrain, India and its tectonic implications  

NASA Astrophysics Data System (ADS)

crustal as well as the upper mantle lithospheric electrical structure of the Southern Granulite Terrain (SGT) is evaluated, using the magnetotelluric (MT) data from two parallel traverses: one is an ~ 500 km long N-S trending traverse across SGT and another a 200 km long traverse. Data space Occam 3-D inversion was used to invert the MT data. The electrical characterization of lithospheric structure in SGT shows basically a highly resistive (several thousands of Ohm meters) upper crustal layer overlying a moderately resistive (a few hundred Ohm meters) lower crustal layer which in turn is underlain by the upper mantle lithosphere whose resistivity shows significant changes along the traverse. The highly resistive upper crustal layer is interspersed with four major conductive features with three of them cutting across the crustal column, bringing out a well-defined crustal block structure in SGT with individual highly resistive blocks showing correspondence to the geologically demarcated Salem, Madurai, and Trivandrum blocks. The 3-D model also brought out a well-defined major crustal conductor located in the northern half of the Madurai block. The electrical characteristics of this south dipping conductor and its close spatial correlation with two of the major structural elements, viz., Karur-Oddanchatram-Kodaikanal Shear Zone and Karur-Kamban-Painavu-Trichur Shear Zone, suggest that this conductive feature is closely linked to the subduction-collision tectonic processes in the SGT, and it is inferred that the Archean Dharwar craton/neoproterozoic SGT terrain boundary lies south of the Palghat-Cauvery shear zone. The results also showed that the Achankovil shear zone is characterized by a well-defined north dipping conductive feature. The resistive block adjoining this conductor on the southern side, representing the Trivandrum block, is shown to be downthrown along this north dipping crustal conductor relative to the Madurai block, suggesting a northward movement of Trivandrum block colliding against the Madurai block. The lithospheric upper mantle electrical structure of the SGT up to a depth of 100 km may be broadly divided into two distinctly different segments, viz., northern and southern segments. The northern lithospheric segment, over a major part, is characterized by a thick resistive upper mantle, while the southern one is characterized by a dominantly conductive medium suggesting a relatively thinned lithosphere in the southern segment.

Patro, Prasanta K.; Sarma, S. V. S.; Naganjaneyulu, K.

2014-01-01

93

U-Pb Detrital Zircon Geochronology and Implications: the Mesozoic southern Ordos Basin, North Central China  

NASA Astrophysics Data System (ADS)

Two deformation belts -- the Qinling orogenic belt (QOB) to the south and the Western Liupanshan thrust belt (WLTB) to the west, including the Qilian-Qaidam terrane (QQT) -- control the evolution of the southern Ordos Basin during early Mesozoic time. U-Pb detrital zircon geochronology is used to identify provenance, reconstruct paleogeography, and document the relative timing of basin margin deformation. Two correlated strata same age samples of the Middle to Late Triassic Yanchang Fm. were collected from the southern and southwestern basin margin respectively. In total 258 zircon grains were analyzed using LA-ICP-MS. Three major age populations -- 240-490 Ma, 1.8-2.0 Ga, and 2.2-2.8 Ga -- characterize the detrital zircon grains of the Yanchang Fm. Regional geochronology studies show that the two oldest age groups match ages of basement rocks found in the underlying North China block. The younger age group can be subdivided into three distinctive groups: 240-300 Ma, 300-400, and 400-490 Ma. The youngest age group matches ages exposed to the west in the QQT, whereas the other two match grains from southern QOB source. In all samples detrital zircon from the WLTB source area overwhelms the QOB source, regardless of its proximity to either basin margin. This result suggests that either the source rock with the youngest zircon grains (e.g. 240- 490 Ma) from the QOB to the south have been eroded away and no longer existed, or simply the QOB, even during deformation, was never the dominant source of detrital zircon to the southern Ordos Basin. Probably some drainage systems far from the west combine with some local tributary systems from the south control the sedimentation in the south Ordos Basin during the middle to Late Triassic time. This is surprising in that most studies suggest that the QOB was a longer lived and more dominant tectonic feature in this part of China during early Mesozoic time. Furthermore, it also indicates that: 1) deformation in the QOB and WLTB began in Middle Triassic time in this area; and 2) the southern source area barely contributed sediment by Late Triassic time.

Xie, X.; Heller, P. L.; Chamberlain, K. R.

2007-12-01

94

Jebel Marra Volcano Caldera, Sudan, Africa  

NASA Technical Reports Server (NTRS)

This excellent view of Jebel Marra Volcano Caldera, Sudan, Africa (13.0N, 24.5E) shows the collapsed mouth of this ancient volcano withh two smaller calderas now acting as lakes. As one of the highest regions of the eastern Sahara Desert, the Jebel Marra receives more rainfall than the surrounding desert. The radial pattern of streams flowing away from the highest points of the calderas is accenuated by a large dark colored lava flow.

1990-01-01

95

Crustal Structure of the Khartoum Basin, Sudan  

NASA Astrophysics Data System (ADS)

The Khartoum basin is one of several Mesozoic rift basins in Sudan associated with the Central Africa Rift System. Little is known about the deep crustal structure of this basin, and this limited knowledge hampers the development of a more detailed understanding of its origin and evolution. Constraints on crustal structure in Sudan are only available through regional gravity studies and continental-scale tomography models, but these studies have poor resolution in the Khartoum basin. Here, we investigate the crustal structure of the northern part of the Khartoum basin beneath 3 permanent seismic stations in Khartoum, Sudan through the H-k stacking of receiver functions and the joint inversion of receiver functions and Rayleigh-wave group velocities. Our H-k-stacking results indicate that crustal thickness beneath the Khartoum basin ranges between 33 and 37 km, with an average of 35 km and that crustal Vp/Vs ratio ranges from 1.74 to 1.81, with an average of 1.78. These results are consistent with 1D velocity models developed from the joint inversion of receiver functions and Rayleigh-wave group velocities, which display similar estimates for crustal thickness and an average shear-wave velocity of 3.7 km/s for the basin's crust. Our results provide the first seismic estimate of Moho depth for a basin in Sudan and, when compared to average crustal thickness for the unrifted Proterozoic crust in eastern Africa, reveal that at most a few kilometers of crustal thinning has occurred beneath the Khartoum basin. Keywords: Teleseismic P-waveforms; Moho depth; Shear wave velocity; Khartoum Basin.

El Tahir, Nada; Nyblade, Andrew; Julia, Jordi; Durrheim, Raymond

2013-04-01

96

Identification of congenital rubella syndrome in Sudan  

PubMed Central

Background Epidemiological data about congenital rubella syndrome (CRS) are scarce and rubella vaccine is not yet included in the childhood immunization schedule in Sudan. This study aimed to identify and describe CRS cases among Sudanese infants with congenital eye or heart defects. Methods Between February and September 2010, paired oral fluid and dried blood spot samples were collected from 98 infants aged up to 12 months. These infants were enrolled during their visits to five hospitals in Khartoum, Sudan. Clinical samples were screened for rubella IgM and for???6 months old infants also for IgG antibodies by ELISA. The oral fluid of IgM and/or IgG positive patients was tested for rubella RNA by reverse transcriptase PCR. Results Our findings revealed that two children (2.0%) were IgM positive and another five children (5.1%) were positive for IgG antibodies. None of the five infants of which enough oral fluid was available for RNA investigation was PCR positive. Conclusions This study documented the presence of CRS in Sudan and highlighted the importance of rubella vaccine introduction for preventing future CRS cases in the country.

2014-01-01

97

Compositional heterogeneity of Asteroid 4 Vesta’s southern hemisphere: Implications for the Dawn mission  

NASA Astrophysics Data System (ADS)

High signal-to-noise, rotationally-resolved spectra of Asteroid 4 Vesta's southern hemisphere from the 2007 opposition were used to constrain its compositional and mineralogical variations. The spectra were rotationally-phased using closely timed HST observations of Vesta by Li et al. (Li, J.-Y., McFadden, L.A., Thomas, P.C., Mutchler, M.J., Parker, J.Wm., Young, E.F., Russell, C.T., Sykes, M.V., Schmidt, B.E. [2010]. Icarus 208, 238-251). The average surface of Vesta's southern hemisphere is analogous to a howardite or polymict eucrite assemblage similar to the northern hemisphere, although the band parameters are distinctly shifted towards the diogenite zone on the Band-Band plot. A few distinct compositional units were detected and they might be related to albedo features detected by Hubble Space Telescope (Li et al., 2010). We have identified two compositionally distinct regions overlaying the background surface. The first unit is a polymict eucrite and/or low-Ca eucrite compositional unit at 143° longitude that border the eucrite zone on the Band-Band plot and the second is a diogenite unit at 159°. While we did not detect any distinct olivine units as suggested by Gaffey (Gaffey, M.J. [1997]. Icarus 127, 130-157), we cannot rule out the possibility of smaller olivine-rich units that are below the detection limit of the instrumentation we used. Based on the analysis and the limitations of the data, we do not suggest that Vesta's surface is olivine-free. Mean pyroxene chemistry estimates for both hemispheres broadly agree with one another (to within one-sigma) with the northern hemisphere ferrosilite (Fs) and wollastonite (Wo) values being slightly higher than southern hemisphere.

Reddy, Vishnu; Gaffey, Michael J.; Kelley, Michael S.; Nathues, Andreas; Li, Jian-Yang; Yarbrough, Robert

2010-12-01

98

Three-dimensional resistivity structure of Southern Alberta, Canada: implications for Precambrian tectonics  

NASA Astrophysics Data System (ADS)

The Precambrian basement rocks in southern Alberta are hidden beneath the Western Canada Sedimentary Basin, making studies of these rocks dependent on geophysical measurements. Magnetotelluric (MT) data were used to study the structure of these basement rocks through measurements of electrical resistivity. Long-period MT data collected in Southern Alberta during the Lithoprobe project were combined with new data to produce a grid of data that permitted a 3-D approach to data analysis. Dimensionality analysis suggested that data at periods less than 1000 s were relatively 2-D. However, 2-D inversion models of MT data in Alberta resulted in low resistivity features in the crust which moved dependant on the data included in the inversion. These features were previously attributed to crustal anisotropy. 3-D inversion yielded a resistivity model that fit the measured MT data and was well correlated with both the Precambrian domain boundaries and interpretations of other geophysical data. This MT data set defines a major upper-mantle conductor coincident with the Archean Loverna Block of the Hearne Domain. This anomaly is called the Loverna Conductor, and its southern boundary is defined by a pronounced increase in upper-mantle resistivity along the Vulcan Structure, which is an approximately 300-km-long linear potential field anomaly completely buried beneath the western Canada Sedimentary Basin. Since the lithosphere in this region was assembled ca. 1.9-1.8 Ga, the low resistivity anomaly in the upper mantle is not associated with recent tectonic activity. The Loverna Conductor was likely formed by the enrichment of the lithospheric mantle through subduction along the Vulcan Structure during the Proterozoic assembly of Laurentia. In particular, this model is consistent with recent interpretations which attribute the origin of the Vulcan Structure to collision along a north dipping subduction zone.

Nieuwenhuis, Greg; Unsworth, Martyn J.; Pana, Dinu; Craven, Jim; Bertrand, Edward

2014-05-01

99

Hyperpycnal sediment discharge from semiarid southern California rivers: Implications for coastal sediment budgets  

USGS Publications Warehouse

Southern California rivers discharge hyperpycnal (river density greater than ocean density) concentrations of suspended sediment (>40 g/L, according to buoyancy theory) during flood events, mostly during El Nin??o-Southern Oscillation (ENSO) conditions. Because hyperpycnal river discharge commonly occurs during brief periods (hours to occasionally days), mean daily flow statistics often do not reveal the magnitude of these events. Hyperpycnal events are particularly important in rivers draining the Transverse Range and account for 75% of the cumulative sediment load discharged by the Santa Clara River over the past 50 yr. These events are highly pulsed, totaling only ??? 30 days (??? 0.15% of the total 50 yr period). Observations of the fate of sediment discharge, although rare, are consistent with hyperpycnal river dynamics and the high likelihood of turbidity currents during these events. We suggest that much of the sediment load initially bypasses the littoral circulation cells and is directly deposited on the adjacent continental shelf, thus potentially representing a loss of immediate beach sand supply. During particularly exceptional events (>100 yr recurrence intervals), flood underflows may extend past the shelf and escape to offshore basins.

Warrick, J. A.; Milliman, J. D.

2003-01-01

100

Malaria-related beliefs and behaviour in southern Ghana: implications for treatment, prevention and control.  

PubMed

A research infrastructure was established in two ecological zones in southern Ghana to study the variables of malaria transmission and provide information to support the country's Malaria Action Plan (MAP) launched in 1992. Residents' beliefs and practices about causes, recognition, treatment and prevention of malaria were explored in two ecological zones in southern Ghana using epidemiological and social research methods. In both communities females constituted more than 80% of caretakers of children 1-9 years and the illiteracy rate was high. Fever and malaria, which are locally called Asra or Atridi, were found to represent the same thing and are used interchangeably. Caretakers were well informed about the major symptoms of malaria, which correspond to the current clinical case definition of malaria. Knowledge about malaria transmission is, however, shrouded in many misconceptions. Though the human dwellings in the study communities conferred no real protection against mosquitoes, bednet usage was low while residents combatted the nuisance of mosquitoes with insecticide sprays, burning of coils and herbs, which they largely considered as temporary measures. Home treatment of malaria combining herbs and over-the-counter drugs and inadequate doses of chloroquine was widespread. There is a need for a strong educational component to be incorporated into the MAP to correct misconceptions about malaria transmission, appropriate treatment and protection of households. Malaria control policies should recognize the role of home treatment and drug shops in the management of malaria and incorporate them into existing control strategies. PMID:9217705

Ahorlu, C K; Dunyo, S K; Afari, E A; Koram, K A; Nkrumah, F K

1997-05-01

101

An increase of dry season length over southern Amazonia, its causes and implication to climate projection  

NASA Astrophysics Data System (ADS)

Observations from several independent sources suggest that the dry season length (DSL) has increased over southern Amazonia since 1979, primarily due to a delay of its ending dates (DSE). Whether such a change is entirely due to natural climate variability or a result of combine natural variability and anthropogenic forced change will be assessed through a process-based analysis. The observed changes appear to be greater than those simulated by the global climate models that participated in the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) forced by both historical and future anthropogenic and natural forcing. Such a discrepancy is unlikely due to under-representation of natural variability and more likely due to underestimate the sensitivity of the dry season length to external forcing. Consequently, the climate projections of these models may underestimate the future changes of the dry season length and its impact on rainforests. Our study suggests that it is imperative that monitoring, quantification, and understanding of changes of rainfall seasonality over southern Amazonia be improved.

Fu, R.; Yin, L.

2013-05-01

102

Spatial genetic structure and regional demography in the southern torrent salamander: Implications for conservation and management  

USGS Publications Warehouse

The Southern torrent salamander (Rhyacotriton variegatus) was recently found not warranted for listing under the US Endangered Species Act due to lack of information regarding population fragmentation and gene flow. Found in small-order streams associated with late-successional coniferous forests of the US Pacific Northwest, threats to their persistence include disturbance related to timber harvest activities. We conducted a study of genetic diversity throughout this species' range to 1) identify major phylogenetic lineages and phylogeographic barriers and 2) elucidate regional patterns of population genetic and spatial phylogeographic structure. Cytochrome b sequence variation was examined for 189 individuals from 72 localities. We identified 3 major lineages corresponding to nonoverlapping geographic regions: a northern California clade, a central Oregon clade, and a northern Oregon clade. The Yaquina River may be a phylogeographic barrier between the northern Oregon and central Oregon clades, whereas the Smith River in northern California appears to correspond to the discontinuity between the central Oregon and northern California clades. Spatial analyses of genetic variation within regions encompassing major clades indicated that the extent of genetic structure is comparable among regions. We discuss our results in the context of conservation efforts for Southern torrent salamanders.

Miller, Mark P.; Haig, Susan M.; Wagner, R. S.

2006-01-01

103

Phylogeography and spatial genetic structure of the Southern torrent salamander: Implications for conservation and management  

USGS Publications Warehouse

The Southern torrent salamander (Rhyacotriton variegatus) was recently found not warranted for listing under the US Endangered Species Act due to lack of information regarding population fragmentation and gene flow. Found in small-order streams associated with late-successional coniferous forests of the US Pacific Northwest, threats to their persistence include disturbance related to timber harvest activities. We conducted a study of genetic diversity throughout this species' range to 1) identify major phylogenetic lineages and phylogeographic barriers and 2) elucidate regional patterns of population genetic and spatial phylogeographic structure. Cytochrome b sequence variation was examined for 189 individuals from 72 localities. We identified 3 major lineages corresponding to nonoverlapping geographic regions: a northern California clade, a central Oregon clade, and a northern Oregon clade. The Yaquina River may be a phylogeographic barrier between the northern Oregon and central Oregon clades, whereas the Smith River in northern California appears to correspond to the discontinuity between the central Oregon and northern California clades. Spatial analyses of genetic variation within regions encompassing major clades indicated that the extent of genetic structure is comparable among regions. We discuss our results in the context of conservation efforts for Southern torrent salamanders. ?? The American Genetic Association. 2006. All rights reserved.

Miller, M. P.; Haig, S. M.; Wagner, R. S.

2006-01-01

104

Salp/krill interactions in the Southern Ocean: spatial segregation and implications for the carbon flux  

NASA Astrophysics Data System (ADS)

Available data on the spatial distribution and feeding ecophysiology of Antarctic krill, Euphausia superba, and the tunicate, Salpa thompsoni, in the Southern Ocean are summarized in this study. Antarctic krill and salps generally display pronounced spatial segregation at all spatial scales. This appears to be the result of a clear biotopical separation of these key species in the Antarctic pelagic food web. Krill and salps are found in different water masses or water mass modifications, which are separated by primary or secondary frontal features. On the small-scale (<100 km), Antarctic krill and salps are usually restricted to the specific water parcels, or are well segregated vertically. Krill and salp grazing rates estimated using the in situ gut fluorescence technique are among the highest recorded in the Antarctic pelagic food web. Although krill and salps at times may remove the entire daily primary production, generally their grazing impact is moderate (?50% of primary production). The regional ecological consequences of years of high salp densities may be dramatic. If the warming trend, which is observed around the Antarctic Peninsula and in the Southern Ocean, continues, salps may become a more prominent player in the trophic structure of the Antarctic marine ecosystem. This likely would be coupled with a dramatic decrease in krill productivity, because of a parallel decrease in the spatial extension of the krill biotope. The high Antarctic regions, particularly the Marginal Ice Zone, have, however, effective physiological mechanisms that may provide protection against the salp invasion.

Pakhomov, E. A.; Froneman, P. W.; Perissinotto, R.

105

Muscadine Grapes, Food Heritage and Consumer Images: Implications for the Development of a Tourism Product in Southern USA  

Microsoft Academic Search

The present study investigates consumer awareness as it relates to muscadine grapes, a southern US food, and the images that muscadines evoke among southern consumers. The written comments of 189 southern residents were gathered in a southern college town. Respondents' images only partly demonstrate their attachment to this traditional food. For example, while over a third of respondents' comments relate

Abel Duarte Alonso; Martin A. Oneill

2012-01-01

106

Tectonic implications of a paleomagnetic study of the Sarmiento Ophiolitic Complex, southern Chile  

NASA Astrophysics Data System (ADS)

A paleomagnetic study was carried out on the Late Jurassic Sarmiento Ophiolitic Complex (SOC) exposed in the Magallanes fold and thrust belt in the southern Patagonian Andes (southern Chile). This complex, mainly consisting of a thick succession of pillow-lavas, sheeted dikes and gabbros, is a seafloor remnant of the Late Jurassic to Early Cretaceous Rocas Verdes basin that developed along the south-western margin of South America. Stepwise thermal and alternating field demagnetization permitted the isolation of a post-folding characteristic remanence, apparently carried by fine grain (SD?) magnetite, both in the pillow-lavas and dikes. The mean "in situ" direction for the SOC is Dec: 286.9°, Inc: - 58.5°, ?95: 6.9°, N: 11 (sites). Rock magnetic properties, petrography and whole-rock K-Ar ages in the same rocks are interpreted as evidence of correlation between remanence acquisition and a greenschist facies metamorphic overprint that must have occurred during latest stages or after closure and tectonic inversion of the basin in the Late Cretaceous. The mean remanence direction is anomalous relative to the expected Late Cretaceous direction from stable South America. Particularly, a declination anomaly over 50° is suggestively similar to paleomagnetically interpreted counter clockwise rotations found in thrust slices of the Jurassic El Quemado Fm. located over 100 km north of the study area in Argentina. Nevertheless, a significant ccw rotation of the whole SOC is difficult to reconcile with geologic evidence and paleogeographic models that suggest a narrow back-arc basin sub-parallel to the continental margin. A rigid-body 30° westward tilting of the SOC block around a horizontal axis trending NNW, is considered a much simpler explanation, being consistent with geologic evidence. This may have occurred as a consequence of inverse reactivation of old normal faults, which limit both the SOC exposures and the Cordillera Sarmiento to the East. The age of tilting is unknown but it must postdate remanence acquisition in the Late Cretaceous. Two major orogenic events of the southern Patagonian Andes, in the Eocene (ca. 42 Ma) and Middle Miocene (ca. 12 Ma), respectively, could have caused the proposed tilting.

Rapalini, A. E.; Calderón, M.; Singer, S.; Hervé, F.; Cordani, U.

2008-06-01

107

Recurrence, Rates, and Paleogeodetic Implications: Southern Cascadia Subduction Zone, Northern California  

NASA Astrophysics Data System (ADS)

Earthquake and tsunami hazard for northern California and southern Oregon is dominated by estimates of recurrence for earthquakes on the Cascadia subduction zone (CSZ) and upper plate thrust faults. Recurrence interval (RI)estimates derived from site based terrestrial data (270-1,370 years) are inconsistent with the regional marine record of great earthquakes (RI = ~240 years). Reconciling these differences reveals information regarding different sources or magnitudes of coseismic or interseismic deformation in the southern CSZ. Early paleoseismic investigations utilized bulk peat for 14C age determinations and lack vertical elevation control. All terrestrial data sets are compiled, evaluated, ranked, and excluded according to their paleoseismic relevance. We construct an OxCal age model to evaluate the discriminated 14C based space-time relations graphically and statistically. We interpret a regional timing of tectonic deformation that is consistent with the timing of the marine record. Not all events are observed in each region and not all events have age control. Some regions lack cores representing the complete modern tidal elevation range (biasing the paleoseismic record). For example, when individual sites in the same region are combined, a more complete record of coseismic subsidence can be assumed, reducing the terrestrial RI to 360+-40, yet still longer than the marine RI. We consider relative sea-level (RSL), as the relation between land-level and sea-level and we find that chronologically distinct buried soils are found in settings segregated by elevation. Subsidence in southern Humboldt Bay occurred in positions of higher RSL at ~1,500, 2,200, and ~3,500 cal yrs BP. We pose that the RSL position does not relate to the time preceding the earthquake, but may relate to the accumulated strain at the time of the earthquake. RSL with a higher position would correspond with more accumulated strain in the upper plate. We evaluate the various factors that may confound this relation. We also compare the estimates of subsidence for cores in locations that share the sea-level / land-level relations as today as these may be a modern analogue to what subsidence we might expect if the CSZ earthquake were to occur tomorrow. Some unknowns that are priorities to complete this analysis include down-core diatom paleoecologic interpretations based upon correlations (transfer function) with modern biogeochemical transects, neither of which currently exist, developing a reliable vertical tidal elevation network tied to distal benchmarks, and there are also several buried soils that lack 14C age determinations. Lastly, additional cores collected in regions that are under sampled with respect to various elevation ranges.

Leroy, T. H.; Patton, J. R.

2010-12-01

108

The impact of war on women and children: case study of Sudan.  

PubMed

Civil war has raged in southern Sudan from 1955 to 1972 and again from 1983 to the present. This situation has been compounded by regional conflicts in other parts of Sudan and wars in neighboring countries. The consequences of war are taking their toll on the entire region and are intensified by environmental hazards, desertification, drought, and famine. The socioeconomic and educational infrastructure has been destroyed in southern Sudan, taking the family support system with it. The atmosphere of continued fighting has made it all but impossible for relief agencies to provide services. The innocent victims of the war are civilians who are forced to choose between disastrous alternatives: if they flee, they lose their homes, their livelihoods, and their communities; if they stay, they watch these things being destroyed around them. Women and children are suffering the most. Hunger and disease are widespread, and immunization programs have been curtailed. Very few school-age children are receiving an education, and children are subject to kidnapping and abuse from soldiers. There may be as many as 3 million people displaced, with 1.5 million living in settled areas and 707,000 in camps in the Khartoum area. Relief aid in the camps is unreliable, and the displace women arrive with no assets or skills. They survive through domestic work, begging, petty trading, or beer-brewing and prostitution (the latter 2 are illegal). Children are left to fend for themselves all day or to find work in situations where they are exploited. In addition to depriving the children of their health, education, and economic stability, the war has resulted in cultural deprivation as ethnic groups lose their sense of identity. Psychological problems are the natural consequence of this situation, and aggressive behavior is seen in the displaced children, while trauma and anxiety plague the children in the war zones. PMID:12318292

El-nagar, S E

1992-06-01

109

Heat flow anomaly in Lesotho - implications for the southern boundary of the Kaapvaal craton  

SciTech Connect

Heat flow studies in southern Africa reveal a pattern of low heat flow in Archean cratons compared with Proterozoic mobile belts that provides grounds for modeling in which cratons have lower mantle heat flux and greater lithospheric thickness. Measurements at nine locations in a 90-km-long north-south traverse show an increase of heat flow from typically cratonic values of about 45 mW/sq m in the north to about 80 mW/sq m where the craton abuts on the Natal belt in the south. The change occurs within 30 km, suggesting that the anomaly largely reflects an increase in radioactive heat from the upper crust in the orogenic front. The change in mantle heat flux across the boundary is probably considerably smaller. These and other results suggest that the surficial craton boundary is further north than usually depicted. 20 refs.

Jones, M.Q.W. (Witwatersrand Univ., Johannesburg (South Africa))

1992-10-01

110

Footprints of large theropod dinosaurs and implications on the age of Triassic biotas from Southern Brazil  

NASA Astrophysics Data System (ADS)

Dinosaur footprints found in an outcrop of the Caturrita Formation (Rio Grande do Sul State, Southern Brazil), associated with a diverse and well preserved record of fauna and flora, reopen the debate about its exclusive Triassic age. The studied footprints were identified as Eubrontes isp. and are interpreted as having been produced by large theropod dinosaurs. The morphological characteristics and dimensions of the footprints are more derived than those commonly found in the Carnian-Norian, and are more consistent with those found during the Rhaetian-Jurassic. The trackmaker does not correspond to any type of dinosaur yet known from Triassic rocks of Brazil. Recent studies with the paleofloristic content of this unit also support a more advanced Rhaetian or even Jurassic age for this unit.

da Silva, Rafael Costa; Barboni, Ronaldo; Dutra, Tânia; Godoy, Michel Marques; Binotto, Raquel Barros

2012-11-01

111

Paleozoic archipelagic tectonic evolution of Western Junggar, NW China: implications for continental growth of southern Altaids  

NASA Astrophysics Data System (ADS)

The Western Junggar, NW China, a dominant site for continental growth in Southern Altaids, bridges the Circum-Balkhash and Junggar belts and exposes ophiolite, igneous rocks and strata from Cambrian to Carboniferous. Recent updated data on structure, geochronology, geochemisty and paleomagnetism, integrated with previous data, present a newly Paleozoic spatial and temporal framework of Western Junggar. In Cambrian, the Western Junggar begins to birth at the Tangbale area to south, where occurs Ordovician blueschist and top-to-south vergence structures, indicating north-dipping subduction. This event triggers intra-arc extension to generate Ordovician island arc in the Hongguleleng-Xiemisitai area to north and seamount in the Mayile area, middle of Western Junggar. Until Silurian, a southeastward subduction begins in the extended back-arc basin to west of Mayile, occurring blueschist at the Barleik trench and the Nalunsuo magmatic arc, at the rear of which generates Devonian back-arc basin around the Durbut area. Meanwhile, a Silurian Xiemisitai magmatic arc has been developed at the northern part of Western Junggar, along which a northward subduction has emplaced the Tarbahatai ophiolite and generates the Carboniferous Sawur magmatic arc. At the middle part of Western Junggar, the coeval adakite and sanukitic dykes, charnockite, multiple properties of ophiolite and plutons, SSZ-like andesite, dacite and rhyolite and regional structures suggest that there develop double-subduction systems with ridge-trench interaction in Carboniferous. These features suggest that the Western Junggar experiences rollback, intra-oceanic extension and subduction polarity reversal/flip in back-arc basin settings. Furthermore, positive ?Nd(t) values and no huge movements of blocks suggest that the Western Junggar is amalgamated by juvenile elements with different orientations. Therefore, we conclude that the Western Junggar enlarges from an island arc to Paleozoic tectonic regime with island arcs and subduction-accretion complexes via continuous accretion presented as episodic events and it significantly contributes to continental growth in southern Altaids.

Zhang, Jien; Xiao, Wenjiao; Han, Chunming; Ma, Chong; Song, Dongfang

2013-04-01

112

Geochemical Characterization of Dust in the Southern Ocean, Provenance and Paleoclimatic implications  

NASA Astrophysics Data System (ADS)

Wind-blown dust can be used to trace past and present atmospheric circulation patterns, through the study of its geographical provenance, its spatial distribution and temporal variability. Antarctic and marine records indicate that Patagonia has been a principal source of dust for the southern latitudes, particularly during glacial times. To improve our understanding of dust provenance and transport mechanisms downstream from South America and part-way to Antarctica, we analyzed the fine (<5 ?m) fraction terrigenous input into the Southern Ocean by studying the 12.76-m piston core TNO57-6, from 3751 m water depth on the Agulhas Ridge in the Southeast Atlantic, north of the present-day position of the Subantarctic Front and South of the Subtropical Convergence Zone. Due to this core's location and depth, and the position of the winds and marine currents, we suggest that the major input of sediment comes from wind-blown dust material originating in South America. To fingerprint better the terrigenous detritus, we measured chemical compositions and Sr-Nd-Pb-He isotope ratios in samples ranging in age from present-day to MIS 6. Additionally we analyzed material from potential dust source areas in different locations in Patagonia to refine their geochemical signatures. Our first results suggest that the glacial and interglacial samples have different provenances, and that the purely Patagonian sources may represent only the glacial end-member of the dust reaching that location. Further analyses at higher time resolution in the marine record will improve understanding of the relationships between the dust arriving at the site with changing climate, and continued study of potential source area samples (including Patagonia and farther North in La Puna and Altiplano) will help define the other end-member in the dust composition, and thus the more active dust sources during interglacial intervals.

Recasens, C.; Goldstein, S. L.; Winckler, G.; Kaplan, M. R.; Gili, S.; Gaiero, D. M.; Anderson, R. F.

2013-12-01

113

Implications of magmatic records for Neotethyan subduction beneath the Eurasian margin (Lhasa terrane, southern Tibet)  

NASA Astrophysics Data System (ADS)

Evidence for magmatism is widely developed in the Lhasa terrane of southern Tibet. Much of this is related to northward subduction of the Neotethyan Ocean prior the India-Eurasia collision. To better understand the tectono-magmatism, we systematically studied the published data for Middle Jurassic-Eocene igneous rocks in southern Tibet. Many of these rocks formed during two important intervals from ca. 110-80 Ma and ca. 65-40 Ma. On the basis of the reported rocks in this area, we considered the possibility that a Neotethyan mid-ocean ridge was subducted during the early peak episode (ca. 110-80 Ma). With this ridge subduction system, hot asthenosphere rose up through a slab window causing both oceanic slab and mantle wedge melting that resulted in peak volcanism during the Late Cretaceous. As young and hot crust at a mid-ocean ridge has a relatively low density, and thus potentially positive buoyancy, the subduction of a buoyant mid-ocean ridge may have led to a reduction in the angle of subduction. Evidence for termination of arc magmatism by the flat subducted oceanic slab is recorded by a magmatic gap ca. 80-65 Ma. Around ca. 65 Ma, the magmatic record appears again accompanied by a southward migration that represents resumption of an oceanic slab subduction at a normal subduction angle. Subsequently, magmatism lasts to ca. 36 Ma before the India-Eurasia collision and reached a peak of activity associated with a magmatic flare-up at 50 Ma. In this subduction system, some magmatic processes triggered formation of porphyry ore deposits and affected the temporal and spatial distribution of ores.

Tan, Jieqing; Aitchison, Jonathan

2014-05-01

114

Evidence of much more intense land convection in the Southern than in the Northern tropics and implications for climate change  

NASA Astrophysics Data System (ADS)

Convective overshooting over tropical land areas is key contributor to the troposphere-to-stratosphere exchange, shown to inject in the lower stratosphere adiabatically cooled air (Pommereau and Held 2007, Khaykin et al., 2012), trace and chemically active gases (Ricaud et al 2007, 2010), ice crystals (Corti et al 2007, Nielsen et al. 2007, Khaykin et al. 2009) and tropospheric clean air diluting the aerosols (Vernier et al., 2011). However, the altitude reached by those events differs dramatically with the hemisphere. They are observed to reach 20-21 km on average in the Southern tropics during the southern summer in contrast to the Northern tropics where they are limited to the tropopause level., indicating that convective overshoots are far less intense in the North. This difference is consistent with the indirect aerosols effect due to the known larger anthropogenic aerosols and desert dust concentrations in the northern hemisphere troposphere, shown by Cloud Resolving Models (CRM) to increase the number and reducing the size of droplets or growlers, resulting in lighter rainfall and reduced convective vertical velocity, that is weaker overshooting. Asides from the reduced cross-tropopause transport reported by all above observations, the lighter rainfall due to the increase anthropogenic pollution and desertification in the industrial era in the North has strong implications for climate change differences between the two hemispheres. Shown in the presentation will be the evidence of the large difference of convective intensity between the two hemispheres from the various satellite observations, followed by an illustration of the difference in tropospheric aerosols loading, and a short discussion on the impact of such contrast between the two hemispheres on their respective past climate evolution.

Pommereau, J.; Khaykin, S.; Vernier, J.; Ricaud, P.

2012-12-01

115

Determination of Sudan Dyes and Para Red in Duck Muscle and Egg by UPLC  

Microsoft Academic Search

A simple, sensitive and reliable UPLC method was developed and validated for the simultaneous determination of six Sudan dyes\\u000a (Sudan Red G, Sudan I, II, III, Sudan Red 7B, Sudan IV) and Para Red in duck muscle and egg samples. Samples were extracted with acetonitrile, then the extract was dried under\\u000a rotary evaporation and dissolved in acetonitrile\\/0.1% formic acid (85:15,

Cun Li; Ting Yang; Yan Zhang; Yin-Liang Wu

2009-01-01

116

Complex Faulting in the Pacific-North America Transform Offshore Southern California And Implications on Plate Boundary Tectonics and Tsunamigenesis  

NASA Astrophysics Data System (ADS)

Complexity in the tectonic model for Pacific-North America transform motion in the offshore southern California region is demonstrated by earthquakes near San Clemente Island and Fortymile Bank. Observed focal mechanisms show movements opposite to those predicted by the plate tectonic theory for right-slip on NW- trending transform faults and observed in other parts of the California Continental Borderland. Also, there is evidence suggesting that moderate earthquakes in the Inner Borderland have greater magnitudes based on long-period seismic waves than the nominal Richter local magnitudes reported in earthquake catalogs. With better data showing the geologic structure of the area now available, we can try to derive a more complete understanding of this complex tectonic behavior and resulting consequences for local tsunamigenesis. The "backwards" earthquakes suggest the occurrence of plate boundary deformation and/or microplate tectonics with the western side of a block containing Fortymile Bank moving instantaneously faster to the northwest than the adjacent block to the west. Such motions may be consistent with clockwise rotation of blocks in the continental borderland due to the regional dextral shear couple as proposed by Crouch (1978) and Luyendyk and others (1980) based upon paleomagnetic and other geologic data. Alternatively, as initially observed for the 1986 Offshore Oceanside earthquake (MS=5.8) by Hauksson and Jones (1988), the anomalous focal mechanism may be due to an inaccurate model of crustal seismic velocity structure for the offshore region. Use of a refined velocity model may show these anomalous earthquakes to have oblique-reverse mechanisms like the 1986 mainshock. Furthermore, more recent seismicity, located with greater accuracy due to expansion of the Southern California Seismograph Network (SCSN), has apparent NE alignments suggestive of significant active secondary fault structure located off the major NW-trending right-slip faults. Such faulting was also inferred to be significant during the clockwise vertical-axis block rotations of the western Transverse Ranges. Interaction between faults within conjugate systems may enhance vertical movements including subsidence at basins where blocks diverge and uplift where blocks converge, thereby producing local tsunamis during large earthquakes. It was not until recently that local earthquake sources were identified offshore Southern California as potentially damaging tsunami sources. Erroneous magnitude estimate of offshore earthquakes can have serious implications for tsunamigenesis and tsunami warning. A half magnitude error can make the difference between a non-tsunamigenic and a tsunamigenic event especially when a marginal event is considered. Better magnitude estimates using long-period seismographs may be necessary for more accurate identification of potentially tsunamigenic local earthquakes.

Legg, M. R.; Barberopoulou, A.

2007-12-01

117

The crustal structure of southern Baffin Bay: implications from a seismic refraction experiment  

NASA Astrophysics Data System (ADS)

Baffin Bay represents the northern extension of the extinct rift system in the Labrador Sea. While the extent of oceanic crust and magnetic spreading anomalies are well constrained in the Labrador Sea, no magnetic spreading anomalies have yet been identified in Baffin Bay. Thus, the nature and evolution of the Baffin Bay crust remain uncertain. To clearly characterize the crust in southern Baffin Bay, 42 ocean bottom seismographs were deployed along a 710-km-long seismic refraction line, from Baffin Island to Greenland. Multichannel seismic reflection, gravity and magnetic anomaly data were recorded along the same transect. Using forward modelling and inversion of observed traveltimes from dense airgun shots, a P-wave velocity model was obtained. The detailed morphology of the basement was constrained using the seismic reflection data. A 2-D density model supports and complements the P-wave modelling. Sediments of up to 6 km in thickness with P-wave velocities of 1.8-4.0 km s-1 are imaged in the centre of Baffin Bay. Oceanic crust underlies at least 305 km of the profile. The oceanic crust is 7.5 km thick on average and is modelled as three layers. Oceanic layer 2 ranges in P-wave velocity from 4.8 to 6.4 km s-1 and is divided into basalts and dykes. Oceanic layer 3 displays P-wave velocities of 6.4-7.2 km s-1. The Greenland continental crust is up to 25 km thick along the line and divided into an upper, middle and lower crust with P-wave velocities from 5.3 to 7.0 km s-1. The upper and middle continental crust thin over a 120-km-wide continent-ocean transition zone. We classify this margin as a volcanic continental margin as seaward dipping reflectors are imaged from the seismic reflection data and mafic intrusions in the lower crust can be inferred from the seismic refraction data. The profile did not reach continental crust on the Baffin Island margin, which implies a transition zone of 150 km length at most. The new information on the extent of oceanic crust is used with published poles of rotation to develop a new kinematic model of the evolution of oceanic crust in southern Baffin Bay.

Suckro, Sonja K.; Gohl, Karsten; Funck, Thomas; Heyde, Ingo; Ehrhardt, Axel; Schreckenberger, Bernd; Gerlings, Joanna; Damm, Volkmar; Jokat, Wilfried

2012-07-01

118

Dracunculiasis Eradication: And Now, South Sudan  

PubMed Central

This report summarizes the status of the global Dracunculiasis Eradication Program as of the end of 2012. Dracunculiasis (Guinea worm disease) has been eliminated from 17 of 21 countries where it was endemic in 1986, when an estimated 3.5 million cases occurred worldwide. Only 542 cases were reported from four countries in 2012, and 103 villages still had indigenous transmission. Most remaining cases were reported from the new Republic of South Sudan, whereas Chad, Ethiopia, and Mali each reported 10 cases or less. Political instability and insecurity in Mali may become the main obstacles to interrupting dracunculiasis transmission forever.

Hopkins, Donald R.; Ruiz-Tiben, Ernesto; Weiss, Adam; Withers Jr., P. Craig; Eberhard, Mark L.; Roy, Sharon L.

2013-01-01

119

Geodynamic implications of Pleistocene ultrarapid vertical-axis rotations in the Southern Apennines, Italy  

NASA Astrophysics Data System (ADS)

Paleomagnetic analysis from lower Pleistocene (Sicilian) mudstones in the Sant'Arcangelo basin (Southern Apennines, Italy) shows no vertical-axis rotations. These results define the upper time constraint on the 23° counterclockwise rotations previously measured in the underlying lower Pleistocene (Santernian Emilian) units of the Sant'Arcangelo basin. These rotations occurred before the Jaramillo subchron in a time span of <0.5 m.y. Paleomagnetic rotations are coeval with the major phases of thrusting along the outer front of the Apennines, do not extend to the Adriatic foreland, and were limited to the hanging wall of the active thrust sheets along the outer front of the Apennines. Rapid counterclockwise rotations, coeval with thrusting and offset on left-lateral faults, represent the surface manifestation of the differential slab retreat and southwestward rollback of the trench in the Calabrian arc region. The unusually fast vertical-axis rotations indicate that the left-lateral component of deformation was particularly intense during the early Pleistocene in the Sant'Arcangelo region, located along the edge of the retreating subduction zone. These data suggest that the lateral breakoff of the African-Ionian-Adriatic subducting lithosphere, imaged by seismic tomography and deep seismicity, occurred in the Sant'Arcangelo region during the early Pleistocene.

Mattei, Massimo; Petrocelli, Vincenzo; Lacava, Donato; Schiattarella, Marcello

2004-09-01

120

Climate on the southern Black Sea coast during the Holocene: implications from the Sofular Cave record  

NASA Astrophysics Data System (ADS)

We present the updated Holocene section of the Sofular Cave record from the southern Black Sea coast (northern Turkey); an area with considerably different present-day climate compared to that of the neighboring Eastern Mediterranean region. Stalagmite ? 13C, growth rates and initial ( 234U/ 238U) ratios provide information about hydrological changes above the cave; and prove to be more useful than ? 18O for deciphering Holocene climatic variations. Between ˜9.6 and 5.4 ka BP (despite a pause from ˜8.4 to 7.8 ka BP), the Sofular record indicates a remarkable increase in rainfall amount and intensity, in line with other paleoclimate studies in the Eastern Mediterranean. During that period, enhanced summertime insolation either produced much stronger storms in the following fall and winter through high sea surface temperatures, or it invoked a regional summer monsoon circulation and rainfall. We suggest that one or both of these climatic mechanisms led to a coupling of the Black Sea and the Mediterranean rainfall regimes at that time, which can explain the observed proxy signals. However, there are discrepancies among the Eastern Mediterranean records in terms of the timing of this wet period; implying that changes were probably not always occurring through the same mechanism. Nevertheless, the Sofular Cave record does provide hints and bring about new questions about the connection between regional and large scale climates, highlighting the need for a more extensive network of high quality paleoclimate records to better understand Holocene climate.

Göktürk, O. M.; Fleitmann, D.; Badertscher, S.; Cheng, H.; Edwards, R. L.; Leuenberger, M.; Fankhauser, A.; Tüysüz, O.; Kramers, J.

2011-09-01

121

Short communication: new HIV infections at Southern New England academic institutions: implications for prevention.  

PubMed

New HIV infections among younger men who have sex with men (MSM) in the United States are escalating. Data on HIV infections in college students are limited. In 2010, three MSM college students presented to our clinic with primary HIV infection (PHI) in a single month. To determine the number of college students among new HIV diagnoses, we reviewed clinical characteristics and molecular epidemiology of HIV-diagnosed individuals from January to December 2010 at the largest HIV clinic in Southern New England. PHI was defined as acute HIV infection or seroconversion within the last 6 months. Of 66 individuals diagnosed with HIV in 2010, 62% were MSM and 17% were academic students (12% college or university, 5% other). Seventy-three percent of students were MSM. Compared to nonstudents, students were more likely to be younger (24 versus 39 years), born in the United States (91% versus 56%), have another sexually transmitted disease (45% versus 11%), and present with PHI (73% versus 16%, all p-values<0.05). Thirty percent of individuals formed eight transmission clusters including four students. MSM were more likely to be part of clusters. Department of Health contact tracing of cluster participants allowed further identification of epidemiological linkages. Given these high rates of PHI in recently diagnosed students, institutions of higher education should be aware of acute HIV presentation and the need for rapid diagnosis. Prevention strategies should focus on younger MSM, specifically college-age students who may be at increased risk of HIV infection. PMID:22724920

Chan, Philip A; Kazi, Shahzeb; Rana, Amaad; Blazar, Ilyse; Dejong, Colette C; Mayer, Kenneth H; Huard, Thomas K; Carleton, Kim; Gillani, Fizza; Alexander, Nicole; Parillo, Zoanne; Flanigan, Timothy P; Kantor, Rami

2013-01-01

122

Subsidence and thermal history of Southern Oklahoma aulacogen: implications for petroleum exploration  

SciTech Connect

Reconstructed subsidence curves and the thermal history of the Southern Oklahoma aulacogen support the concept of thermally controlled isostatic subsidence for the formation of the basin and indicate the significance of this concept for petroleum exploration. Two mechanisms - initial elastic flexure, followed by detachment and differential subsidence of the aulacogen - are inferred from the subsidence curves. Two methods have been used for reconstruction of the thermal history. A tectonophysics model in combination with a history of basin evolution demonstrates that geothermal gradient and depth-of-burial were dynamic variables during the subsidence stage; maximum paleotemperatures were attained during Sylvan (Late Ordovician) time near the close of subsidence; and most of the Arbuckle Group had been subjected to the temperature conditions of oil formation (the oil liquid window) prior to the possible phase of fluid migration in Sylvan time. The second method, involving reconstruction of the geothermal history on the basis of geothermometry (palynomorph carbonization), suggests: (1) paleotemperatures exerted a significant effect on the level of organic metamorphism in the sedimentary rocks; (2) the geothermal gradient varied during the subsidence stage; (3) paleotemperatures were higher than those predicted by the theoretical model and support the hypothesis of formation of the basin by thermally controlled subsidence, and the application of this concept for petroleum exploration.

Feinstein, S.

1981-12-01

123

Crustal tomographic imaging and geodynamic implications toward south of Southern Granulite Terrain (SGT), India  

NASA Astrophysics Data System (ADS)

The crustal structure toward southern part of SGT is poorly defined leaving an opportunity to understand the tectonic and geodynamic evolution of this high-grade granulite terrain surrounded by major shear and tectonically disturbed zones like Achankovil Shear Zone (AKSZ) and Palghat Cauvery Shear Zone (PCSZ). To develop a geologically plausible crustal tectonic model depicting major structural elements, a comprehensive tomographic image was derived using deep-seismic-sounding data corroborated by Bouguer gravity modeling, coincident-reflection-seismic, heat-flow and available geological/geochronological informations along the N-S trending Vattalkundu-Kanyakumari geotransect. The final tectonic model represents large compositional changes of subsurface rocks accompanied by velocity heterogeneities with crustal thinning (44-36 km) and Moho upwarping from north to south. This study also reveals and successfully imaged anomalous zone of exhumation near AKSZ having transpression of exhumed rocks at mid-to-lower crustal level (20-30 km) with significant underplating and mantle upwelling forming a complex metamorphic province. The presence of shear zones with high-grade charnockite massifs in the upper-crust exposed in several places reveal large scale exhumation of granulites during the Pan-African rifting (~ 550 Ma) and provide important insights of plume-continental lithosphere interaction with reconstruction of the Gondwanaland.

Behera, Laxmidhar

2011-09-01

124

Snow-avalanche impact landforms in Breheimen, southern Norway: Origin, age, and paleoclimatic implications  

SciTech Connect

Twelve snow-avalanche ramparts in Jostedalen and Sprongdalen (Breheimen, southern Norway) are investigated to elucidate processes of formation, the history of avalanche activity, and their potential for paleoclimatic reconstruction. Variation in the form of these riverbank boulder ramparts reflects local patterns of avalanche impact. Differences in clast roundness between ramparts, avalanche tracks, and river beds indicate that, on average, 50 to 60% of the clasts in the ramparts originate from river bedload as opposed to avalanche source areas or tracks. Rampart clasts increase in roundness downstream over a distance of 12 km, and the contribution from the river bed varies from 26 to 80% depending on local factors. Conventional lichenometric dating suggests ages for the initiation of rampart formation of 250 to 2000 yr, but they probably have a much longer history. Lichen-size frequency distributions, using the largest lichen from each of n boulders, reflect the age-frequency of surface boulders, providing a record of late Holocene avalanche activity. A simulation model suggests that maximum avalanche activity affected nine of the ramparts during the 19th century, after the peak of the Little Ice Age. The pattern of avalanche activity differs from the pattern of glacier variations but is in close agreement with that of debris-flow activity. The ramparts may yield a valuable proxy record of winter snowfall. 48 refs., 12 figs., 4 tabs.

Matthews, J.A.; McCarroll, D. (Univ. of Wales, Swansea (United Kingdom))

1994-05-01

125

Neoproterozoic rifting in the southern Georgina Basin, central Australia: Implications for reconstructing Australia in Rodinia  

NASA Astrophysics Data System (ADS)

A system of northwest striking Neoproterozoic rift basins underlies Paleozoic strata in the southern Georgina Basin of central Australia. Normal faults bounding these rift basins were selectively reactivated during the mid-Paleozoic Alice Springs Orogeny and are now expressed as high-angle reverse faults that invert the preexisting rift basins. Exhumed and eroded rift basin remnants are present in the hanging wall of the Oomoolmilla, Lucy Creek, Tarlton, and Toomba reverse faults, and rift basins may be preserved in the subsurface beneath the Toko Syncline and Burke River Structural Belt. Rift basin fill indicates two periods of extension: a major rift-forming episode between approximately 700 and 650 Ma (coeval with Sturtian glacial deposits) and a second episode of extension at approximately 600 Ma (coeval with Marinoan glacial deposits). This northwest striking rift system in central Australia supports results from other regions, indicating that the Neoproterozoic continental margin of Australia consisted of northwest striking rift segments offset by northeast striking transform faults. Such a configuration is geometrically incompatible with a Laurentian continental margin consisting of northeast striking rift segments and conflicts with reconstructions such as SWEAT and AUSWUS that match Australia with western Laurentia in the Rodinia supercontinent.

Greene, David C.

2010-10-01

126

A new oviraptorosaur (Dinosauria: Oviraptorosauria) from the late cretaceous of southern China and its paleoecological implications.  

PubMed

A new oviraptorosaur Nankangia jiangxiensis gen. et sp. nov. is described on the basis of a partial postcranial skeleton with a partial lower jaw collected from the Upper Cretaceous Nanxiong Formation of Ganzhou, in Jiangxi Province of southern China. The new taxon is diagnosed by: (1) a mandibular symphysis that is not turned down; (2) neural spines of the cranial caudal vertebrae that are wider transversely than anteroposteriorly, forming a large posterior fossa with rugose central areas; (3) a femoral neck extending at an angle of about 90 to the shaft; and (4) a ratio of femur to tibia length of 0.95. Phylogenetic analysis recovers Nankangia as basal to the oviraptorid Yulong, but more derived than Caenagnathus, which also has a mandibular symphysis that is not turned down. The coexistence of Nankangia jiangxiensis, Ganzhousaurus nankangensis, Jiangxisaurus ganzhouensis, an unnamed oviraptorid from Nanxiong Basin and Banji long suggests that they occupied distinct ecological niches. Nankangia may have been more herbivorous than carnivorous. PMID:24312233

Lü, Junchang; Yi, Laiping; Zhong, Hui; Wei, Xuefang

2013-01-01

127

Floristic Relationships Among Vegetation Types of New Zealand and the Southern Andes: Similarities and Biogeographic Implications  

PubMed Central

Background and Aims Similarities between the floras of geographically comparable regions of New Zealand (NZ) and the southern Andes (SA) have interested biologists for over 150 years. The present work selects vegetation types that are physiognomically similar between the two regions, compares their floristic composition, assesses the environmental factors that characterize these matching vegetation types, and determines whether phylogenetic groups of ancestral versus modern origin are represented in different proportions in their floras, in the context of their biogeographic history. Methods Floristic relationships based on 369 genera of ten vegetation types present in both regions were investigated with correspondence analysis (CA) and ascending hierarchical clustering (AHC). The resulting ordination and classification were related to the environmental characteristics of the different vegetation types. The proportions of different phylogenetic groups between the regions (NZ, SA) were also compared, and between forest and non-forest communities. Key Results Floristic similarities between NZ and SA tend to increase from forest to non-forest vegetation, and are highest in coastal vegetation and bog. The floras of NZ and SA also differ in their phylogenetic origin, NZ being characterized by an ‘excess’ of genera of basal origin, especially in forests. Conclusions The relatively low similarities between forests of SA and NZ are related to the former being largely of in situ South American and Gondwanan origin, whereas the latter have been mostly reconstituted though transoceanic dispersal of propagules since the Oligocene. The greater similarities among non-forest plant communities of the two regions result from varied dispersal routes, including relatively recent transoceanic dispersal for coastal vegetation, possible dispersal via a still-vegetated Antarctica especially for bog plants, and independent immigration from Northern Hemisphere sources for many genera of alpine vegetation and grassland.

Ezcurra, Cecilia; Baccala, Nora; Wardle, Peter

2008-01-01

128

Stratigraphy of the Younger Dryas Chronozone and paleoenvironmental implications: Central and Southern Great Plains  

USGS Publications Warehouse

The Great Plains of the United States was the setting for some of the earliest research in North America into patterns and changes in the character of late Pleistocene environments and their effects on contemporary human populations. Many localities in the region have well-stratified records of terminal Pleistocene and early Holocene human (Paleoindian) activity and past environments. These have proven important in debates over the character of the Younger Dryas Chronozone (YDC; 11,000-10,000 14C BP; 12,900-11,700 cal BP) in the continental interior. This paper reviews the lithostratigraphic record of the YDC on the Central and Southern Great Plains and summarizes paleobiological records (largely isotopic). The goal is to determine if there is any uniformity in the timing, character, direction and/or magnitude of changes in depositional environments or broader geomorphic systems before, during or after the YDC in order to address the question of the character of environments through this time. The stratigraphic records of the late Pleistocene to early Holocene transition, and in particular, the stratigraphic records of the YDC vary through time and space. The data clearly show that a host of geomorphic processes produced the terminal Pleistocene and early Holocene stratigraphic records of the Great Plains. Moreover, the YDC is not necessarily manifest as a distinct lithostratigraphic or biostratigraphic entity in these different types of deposits and soils. The various geomorphic systems of the Great Plains did not behave synchronously in response to any common climate driver. These stratigraphic records reflect local environmental conditions and probably a complex response to the reorganization of mid-latitude climates in the terminal Pleistocene and early Holocene. ?? 2011 Elsevier Ltd and INQUA.

Holliday, V. T.; Meltzer, D. J.; Mandel, R.

2011-01-01

129

Reconstructing Younger Dryas plateau icefields in the Tweedsmuir Hills, Southern Uplands, Scotland: Style, dynamics and palaeo-climatic implications  

NASA Astrophysics Data System (ADS)

In Britain, the glacial geomorphological record has been widely utilised to infer palaeo-glacier geometries and ice dynamics, with much of this work focusing on the Scottish Highlands during the Last Glacial Interglacial Transition (LGIT), in particular the Younger Dryas (YD; c. 12.9 - 11.7 ka BP). The Southern Uplands represents the largest upland area south of the Highlands but has received limited research attention over the last century. The Tweedsmuir Hills are located in the central Southern Uplands, which form an area of dissected plateau approximately 320 km2. Early research in the 1800s identified moraines thought to be associated with the YD. However, the majority of previous work has focussed on isolated valleys and ignored the potential for plateau icefield glaciation, which has significant implications for the understanding of ice dynamics and geometries. Recent numerical modelling experiments covering the period 38 - 10.4 ka BP (Hubbard et al., 2008 cf. E109B8 and E102b2) have predicted a significant body of ice for the Southern Uplands at the onset of and throughout the YD, which cannot be verified at present due to a lack of empirical data. This research aims to provide the first systematic geomorphological mapping and Lateglacial climate reconstruction for the Tweedsmuir Hills. The results of air-photo interpretation and field mapping, which utilised a morphostratigraphic approach, have demonstrated a more extensive glaciation than previously mapped, reflecting more closely the Hubbard et al. (2009) modelled extent than earlier research. This consists of two separate icefields over the southern and northern Tweedsmuir Hills covering an area c. 45 km2 and 25 km2 respectively with Equilibrium Line Altitudes (ELAs) calculated to have ranged from c.419 m to 634 m. For both icefields ELAs of individual outlets reflect topographic controls rather than steep precipitation gradients similar to those derived for other icefields in Scotland (e.g., the Monadhliath Mountains and Beinn Dearg). New radiocarbon dating of basal contact organics place the ice-mass within the context of the YD but new Cosmogenic Nuclide Analysis (CNA) of bedrock and in situ boulders are inconclusive, implying limited erosion and limited resetting during the YD. Landform evidence also indicates smaller independent glaciers occupied some of the south-easterly catchments until the end of the YD. All of these results differ significantly from the traditional paradigm which suggests that due to low accumulation rates, only restricted ice masses developed in the Tweedsmuir Hills during this time. References: Hubbard, A. et al., (2009). Dynamic cycles, ice streams and their impact on the extent, chronology and deglaciation of the British-Irish ice sheet. Quaternary Science Reviews, (28), 7-8, 758-776

Pearce, Danni; Rea, Brice; Bradwell, Tom; Barr, Iestyn; Small, David; McDougall, Des

2014-05-01

130

Structural Inversion of the Palos Verdes Fault, Southern California, and its Implications for Seismic Hazards Assessment  

NASA Astrophysics Data System (ADS)

The Palos Verdes Fault (PVF) defines the western margin of the Los Angeles basin, and is regarded as a likely source of moderate to large earthquakes that would affect the coastal metropolitan regions of southern California. In most hazard compilations, the PVF is generally considered to be a vertical, predominantly right-lateral, strike-slip fault system that extends continuously from the Santa Monica thrust southward across Santa Monica Bay, crossing the Palos Verdes Peninsula and continuing southeast across the Inner Borderlands to the area of Coronado Banks. A restraining bend where the fault dips steeply to the southwest generates uplift and folding of the Palos Verdes Peninsula. However, previous studies documenting the activity, slip rate, and slip sense of the PVF have used shallow subsurface excavations and high-frequency seismic data, which have generally limited observations to the upper kilometer of the crust. We use an extensive grid of petroleum industry seismic reflection data and well logs to define the three-dimensional subsurface geometry of the PVF in the region south of the Palos Verdes Peninsula. Our seismic data cover the complete offshore extent of the fault, from Santa Monica Bay to the Coronado Banks, and provide direct constraints on the fault geometry extending down to about 5km depth. We use the shapes of folded strata imaged in the seismic data and penetrated by wells to invert for permissible geometries of the fault as it extends to the base of the seismogenic crust. Our data and structural analyses indicate that the PVF developed by Pliocene inversion of a Miocene normal fault system. The fault has a significant component of reverse slip and southwesterly dip at depth along its extent. Oblique displacement on the fault appears to be partitioned at shallow levels into nearly pure right-lateral strike slip on near-vertical faults and contractional folding above gently to moderately dipping blind-thrust fault splays. These observations are used to define a realistic 3D geometry of the PVF, to define the sizes, shapes and spatial relationships of fault segments that may rupture in earthquakes, and to extend shallow slip and slip rate estimates from previous studies to depth along the fault. This fault model will provide improved forecasts of the possible size and frequency of large earthquakes on the PVF, and will provide more accurate geometric fault representations that can be used to predict strong ground motions resulting from these events.

Brankman, C. M.; Shaw, J. H.

2004-12-01

131

Different styles of deformation in the calabrian arc (Southern Italy): Implications for a seismotectonic zoning  

NASA Astrophysics Data System (ADS)

The most recent seismic profiles in southern Italy show the existence of a sudden thinning of the crust at the boundary between the chain and the Tyrrhenian margin. The abrupt change in thickness can be followed along a zone which has the same geometry in plan as the Calabrian arc. By considering these data and the gravimetric anomalies, it is possible to associate this crustal anomaly with a deep-seated shear zone which determines a crustal shortening of about 40-60 km which can only be a consequence of post-Tortonian tectonics. The surface equivalents of the deep-seated shear zone can be recognized, from north to south, in the alignment of the intra-Apenninic basins (Vallo di Diano, San Arcangelo, Potenza), in the Crati-Mesima graben and in the Mount Kumeta-Alcantara fault zone. The distribution of the seismicity and its connection with the surface structures shows that the largest earthquakes occur along the deep shear-zone. In particular, shocks with the highest magnitude and the longest recurrence intervals are located in those areas where the deep shear zone is at an angle of about 90° with the direction of maximum shortening (Crati-Mesima graben). The fault zones nearly parallel to the regional compression axis (e.g., Mount Kumeta-Alcantara fault zone) are characterized by earthquakes of lower magnitude. Taking into account the neotectonic evolution of the regional structures, as well as the orientation of the stress field and its connection with the deep-seated shear zone, it is possible to distinguish the following seismotectonic zones: Upper Crati-Mesima graben, transverse throughs, Mount Pollino-Mount Raparo fault zone, external Ionian area, San Arcangelo basin-zone of the external flysch, Sicani Mountains, Mount Kumeta-Alcantara fault zone, Caltanissetta basin, and Iblean plateau-Bradanic trough-Murge ridge. The definition of the geometry of the shear zone at depth is one of the most important, but still unresolved problems.

Ghisetti, F.; Vezzani, L.

1982-05-01

132

A sediment budget for the southern reach in San Francisco Bay, CA: implications for habitat restoration  

USGS Publications Warehouse

The South Bay Salt Pond Restoration Project is overseeing the restoration of about 6000 ha of former commercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m3 of sediment to raise the surface of the subsided areas to elevations appropriate for tidal marsh colonization and development. Therefore, a sufficient sediment supply to the far south SFB subembayment is a critical variable for achieving restoration goals. Although both major tributaries to far south SFB have been seasonally gaged for sediment since 2004, the sediment flux at the Dumbarton Narrows, the bayward boundary of far south SFB, has not been quantified until recently. Using daily suspended-sediment flux data from the gages on Guadalupe River and Coyote Creek, combined with continuous suspended-sediment flux data at Dumbarton Narrows, we computed a sediment budget for far south SFB during Water Years 2009–2011. A Monte Carlo approach was used to quantify the uncertainty of the flux estimates. The sediment flux past Dumbarton Narrows from the north dominates the input to the subembayment. However, environmental conditions in the spring can dramatically influence the direction of springtime flux, which appears to be a dominant influence on the net annual flux. It is estimated that up to several millennia may be required for natural tributary sediments to fill the accommodation space of the subsided former salt ponds, whereas supply from the rest of the bay could fill the space in several centuries. Uncertainty in the measurement of sediment flux is large, in part because small suspended-sediment concentration differences between flood and ebb tides can lead to large differences in total mass exchange. Using Monte Carlo simulations to estimate the random error associated with this uncertainty provides a more statistically rigorous method of quantifying this uncertainty than the more typical “sum of errors” approach. The results of this study reinforce the need for measurement of estuarine sediment fluxes over multiple years (multiple hydrologic conditions) to adequately detail the variability in flux. Additionally, the timing of breaching events for the restoration project could be tied to annual hydrologic conditions to capitalize on increased regional sediment supply.

Shellenbarger, Gregory G.; Wright, Scott A.; Schoellhamer, David H.

2013-01-01

133

Scale-up of a programme for malaria vector control using long-lasting insecticide-treated nets: lessons from South Sudan  

PubMed Central

Abstract Problem Long-lasting insecticidal nets (LLINs) are important tools in malaria control. South Sudan, like many other endemic countries, has struggled to improve LLIN coverage and utilization. Approach In 2006, Southern Sudan – known as South Sudan after independence in 2011 – initiated a strategic plan to increase LLIN coverage so that at least 60% of households had at least one LLIN each. By 2008, the target coverage was 80% of households and the Global Fund had financed a phased scale-up of LLIN distribution in the region. Local setting South Sudan’s entire population is considered to be at risk of malaria. Poor control of the vectors and the large-scale movements of returnees, internally displaced people and refugees have exacerbated the problem. Relevant changes By 2012, approximately 8.0 million LLINs had been distributed in South Sudan. Between 2006 and 2009, the percentage of households possessing at least one LLIN increased from about 12% to 53% and LLIN utilization rates increased from 5 to 25% among children younger than 5 years and from 5 to 36% among pregnant women. The number of recorded malaria cases increased from 71 948 in 2008 to 1 198 357 in 2012. Lessons learnt In post-conflict settings, a phased programme for the national scale-up of LLIN coverage may not have a substantial impact. A nationwide campaign that is centrally coordinated and based on sound guidelines may offer greater benefits. A strong partnership base and effective channels for the timely and supplementary deployment of LLINs may be essential for universal coverage.

Remijo, Constantino D; Pasquale, Harriet; Baba, Samson P; Lako, Richard L

2014-01-01

134

Cattle brucellosis in traditional livestock husbandry practice in Southern and Eastern Ethiopia, and its zoonotic implication  

PubMed Central

Background Cattle brucellosis has significant economic and zoonotic implication for the rural communities in Ethiopia in consequence of their traditional life styles, feeding habits and disease patterns. Hence, knowledge of brucellosis occurrence in traditional livestock husbandry practice has considerable importance in reducing the economic and public health impacts of the disease. Methods A total of 1623 cattle sera were serially tested using the rose Bengal test as screening and complement fixation test as confirmatory tests. The Stata survey command was used to establish prevalences for the overall and individual variables, while potential risk factors for seropositivity were analyzed using a multivariable logistic regression analysis. Results The results showed that 3.5% (95% CI = 2.4, 4.5%) of the animals and 26.1% (95% CI = 18.6, 33.7) of the herds tested had antibodies against Brucella species. Village level seroprevalence ranged from 0% to 100%. A higher seroprevalence was observed in pastoral system than mixed farming although this variable was not significant in the final model. The final logistic regression model identified herd size; with large (odd ratio (OR) = 8.0, 95% CI = 1.9, 33.6) and medium herds (OR = 8.1, 95% CI = 1.9, 34.2) showing higher risk of Brucella infection when compared to small herds. Similarly, the odds of Brucella infection was higher in cattle aged above 4 years when compared to age groups of 1-2 (OR = 5.4, 2.1, 12.9) and 3-4 years (OR = 3.1, 95% CI = 1.0, 9.6). Herd level analysis of the risk factors revealed that large and medium herds as well as herds kept with multiple livestock species were at higher risk of acquiring Brucella infection. Brucellosis in traditional livestock husbandry practices certainly poses a zoonotic risk to the public, in consequence of raw milk consumption, close contact with animals and provision of assistance during parturition. Due to lack of diagnostic facilities and information on its occurrence, human brucellosis is most likely misdiagnosed for other febrile diseases prevailing in the areas and treated empirically. Conclusions The results of this study demonstrated that bovine brucellosis is widely prevalent in the study areas particularly in pastoral production system. Hence, the study suggests the need for implementing control measures and raising public awareness on prevention methods of brucellosis.

2011-01-01

135

A population study in cotton ginnery workers in the Sudan  

Microsoft Academic Search

Khogali, M. (1969).Brit. J. industr. Med.,26, 308-313. A population study in cotton ginnery workers in the Sudan. An epidemiological study in cotton ginneries in the Sudan covered 323 permanently employed ginnery workers, a random sample of 35 seasonal farfara workers, and a control group of 24 members of a fire brigade. All the workers studied were men.The study showed a

Mustafa Khogali

1969-01-01

136

Kangaroo tooth enamel oxygen and carbon isotope variation on a latitudinal transect in southern Australia: implications for palaeoenvironmental reconstruction.  

PubMed

Tooth enamel apatite carbonate carbon and oxygen isotope ratios of modern kangaroos (Macropus spp.) collected on a 900-km latitudinal transect spanning a C(3)-C(4) transition zone were analysed to create a reference set for palaeoenvironmental reconstruction in southern Australia. The carbon isotope composition of enamel carbonate reflects the proportional intake of C(3) and C(4) vegetation, and its oxygen isotope composition reflects that of ingested water. Tooth enamel forms incrementally, recording dietary and environmental changes during mineralisation. Analyses show only weak correlations between climate records and latitudinal changes in ?(13)C and ?(18)O. No species achieved the ?(13)C values (~-1.0 ‰) expected for 100 % C(4) grazing diets; kangaroos at low latitudes that are classified as feeding primarily on C(4) grasses (grazers) have ?(13)C of up to -3.5 ‰. In these areas, ?(13)C below -12 ‰ suggests a 100 % C(3) grass and/or leafy plant (browse) diet while animals from higher latitude have lower ?(13)C. Animals from semi-arid areas have ?(18)O of 34-40 ‰, while grazers from temperate areas have lower values (~28-30 ‰). Three patterns with implications for palaeoenvironmental reconstruction emerge: (1) all species in semi-arid areas regularly browse to supplement limited grass resources; (2) all species within an environmental zone have similar carbon and oxygen isotope compositions, meaning data from different kangaroo species can be pooled for palaeoenvironmental investigations; (3) relatively small regional environmental differences can be distinguished when ?(13)C and ?(18)O data are used together. These data demonstrate that diet-isotope and climate-isotope relationships should be evaluated in modern ecosystems before application to the regional fossil record. PMID:22915330

Brookman, Tom H; Ambrose, Stanley H

2013-02-01

137

Structural evolution of the Laurentian margin revisited (southern Quebec Appalachians): Implications for the Salinian orogeny and successor basins  

NASA Astrophysics Data System (ADS)

The Laurentian margin of the Appalachians is divided into external and internal zones on the basis of metamorphic and structural contrasts. In the southern Quebec internal zone, Silurian to Early Devonian southeast-verging structures are superimposed on northwest-verging structures, whereas most of the external zone lacks such overprints. Regional backthrust faults define a major upper plate lower plate boundary; the external-zone rocks are in the hanging wall, and internal-zone rocks are in the footwall. Metamorphic rocks with Silurian Early Devonian 40Ar/39Ar ages (430 410 Ma) characterize the lower plate. To the east, the Saint-Joseph fault and the Baie Verte Brompton line are southeast- dipping normal faults that crosscut the upper plate lower plate boundary. Metamorphic rocks with Middle Ordovician 40Ar/39Ar ages (469 461 Ma) and rocks of the external zone both occur in the downthrown side of the Saint-Joseph fault and the Baie Verte Brompton line. U-Pb and 40Ar/39Ar ages suggest that the northwest-verging structures are related to ophiolite obduction and crustal thickening during the Taconian orogeny (ca. 480 445 Ma), whereas the southeast-verging structures formed during Silurian Early Devonian backthrusting and normal faulting. The revised structural interpretation has implications for the Salinian orogeny and involves (1) southeast-directed transport of the Taconian crustal wedge of the upper plate, followed by normal faulting and juxtaposition with the lower plate along the Saint-Joseph fault and the Baie Verte Brompton line, and (2) the formation of fault-bounded sedimentary basins, such as the Connecticut Valley Gaspé trough.

Tremblay, Alain; Castonguay, Sébastien

2002-01-01

138

Late Quaternary tectonics in the inner Northern Apennines (Siena Basin, southern Tuscany, Italy) and their seismotectonic implication  

NASA Astrophysics Data System (ADS)

Defining the most recent Quaternary tectonics represents a challenging task for neotectonic, palaeoseismological and seismotectonic studies. This paper focuses on an integrated approach to reconstructing the latest Quaternary deformation affecting the northern part of the Siena Basin (inner Northern Apennines, i.e., southern Tuscany, Italy) near the town of Siena, and to discuss the seismological implications. Field work and structural and stratigraphic analyses, coupled with the interpretation of reflection seismic lines, have been combined to define the geometry, kinematics and age of mesoscopic to map-scale faults which have affected the mainly Quaternary continental and Pliocene marine deposits. The resulting dataset describes a tectonic setting characterized by coeval SW- and NW-trending transtensional and normal faults, respectively, dissecting alluvial sediments younger than 23.9 ± 0.23 ka. Seismic interpretation sheds light on the geometrical setting of the faults at deeper levels, down to 1–2 km, and provides support for the presence of a wide brittle shear zone defined by conjugated fault segments, locally giving rise to an asymmetrical negative flower-like structure. Faults and their damage zones have controlled (and still control) the discharge of gas vents (mainly CO2 and H2S) and hydrothermal circulation (which deposits travertine) since at least 23.216 ± 0.124 ka. The resulting complete data set provides support for our description of the Neogene–Quaternary tectonics which were active until the late Quaternary, providing additional information about the seismotectonic framework of an area characterized by low seismicity and generally low-magnitude earthquakes (M < 4), but having experienced significant seismic events over the last few centuries.

Brogi, Andrea; Capezzuoli, Enrico; Martini, Ivan; Picozzi, Matteo; Sandrelli, Fabio

2014-05-01

139

Crustal structure of the Khartoum Basin, Sudan  

NASA Astrophysics Data System (ADS)

The crustal structure of the northern part of the Khartoum Basin has been investigated using data from 3 permanent seismic stations within 40 km of Khartoum and two modeling methods, H-k stacking of receiver functions and a joint inversion of receiver functions and Rayleigh wave group velocities. The Khartoum Basin is one of several Mesozoic rift basins in Sudan associated with the Central African Rift System. Results from the H-k-stacking indicate that crustal thickness beneath the Khartoum Basin ranges between 33 and 37 km, with an average of 35 km, and that the crustal Vp/Vs ratio ranges from 1.74 to 1.81, with an average of 1.78. From the joint inversion of receiver functions and Rayleigh wave group velocities, we obtained similar results for Moho depth, as well as an average shear wave velocity of 3.7 km/s for the crust. These results provide the first seismic estimates of Moho depth for a basin in Sudan. When compared to average crustal thickness for unrifted Proterozoic crust in eastern Africa, our results indicate that at most only a few km of crustal thinning may have occurred beneath the Khartoum Basin. This finding is consistent with estimates of effective elastic plate thickness, which indicate little modification of the Proterozoic lithosphere beneath the basin, and suggests that there may be insufficient topography on the lithosphere-asthenosphere boundary beneath the Sudanese basins to channel plume material westward from Ethiopia. We found the average crustal thickness beneath the Khartoum basin is 35 km. We found the average crustal Vp/Vs ratio is 1.78. We obtained the average shear wave velocities of 3.7 km/s for the crust. We found small amount of thinning beneath the Khartoum basin. Insufficient topography beneath the basin to channel plume material from Ethiopia.

El Tahir, Nada; Nyblade, Andrew; Julià, Jordi; Durrheim, Raymond

2013-05-01

140

The induction of cytochrome P450 1A1 by sudan dyes.  

PubMed

Azo dyes form a major class of chemically related compounds that are ubiquitous in foods, paints, printing inks, cosmetics, and also used as biological stains in histological and histopathological laboratories and clinics. Sudan I, sudan III, and sudan IV have been classified as category 3 carcinogens by International Agency for Research on Cancer. In this study, we investigated the difference between these three sudan dyes in induction of CYP1A1. We intraperitoneally treated Wistar rats with each of the three sudan dyes (I, III, and IV) for 3 days. Treatment of Wistar rats with sudan I produced the highest induction of CYP1A1 protein and mRNA whereas treatment of Wistar rats with sudan III produced about two third of CYP1A1 protein and mRNA than induced by sudan I. Furthermore, treatment of Wistar rats with sudan IV produced the lowest induction of CYP1A1 protein and mRNA which is about two third of that induced with sudan III treatment. We further investigated the effect of these sudan dyes on CYP1A1 transcription through investigating the xenobiotic response element (XRE) reporter activity in HepG2. The XRE reporter activity study showed the same trend of activity of sudan dyes comparable to the effects on CYP1A1 mRNA and protein. Immunohistochemical study revealed a differential pattern of distribution of CYP1A1 protein in rat liver among the three sudan dyes, apparent in the centrilobular and midzonal region with sudan III, progressing to panlobular with sudan I, whereas sudan IV showed a reversal of pattern of induction with the most intense staining in the periportal region. Our results suggest that there is an inverse relationship between the molecular size of the three sudan dyes and their ability to induce CYP1A1. PMID:18418879

Refat, Nahla A G Ahmed; Ibrahim, Zein Shaban; Moustafa, Gihan Gamal; Sakamoto, Kentaro Q; Ishizuka, Mayumi; Fujita, Shoichi

2008-01-01

141

Determining the effect of climate change and development on water resources management in the Sudan  

NASA Astrophysics Data System (ADS)

The effects of development and the uncertainty of climate change in East Africa provide a myriad of challenges for water managers along the Blue Nile. The construction of the Grand renaissance dam (GRD), as well as the unknown trajectory of precipitation trends in the Ethiopian highlands may greatly affect the countries that rely on the Nile. Sudan's huge irrigation potential and dams that feed multiple current irrigation schemes as well as its location within the basin means that Sudan's water management decisions may reverberate and have social, economic and political implications within the east African sub-region. Here, we apply a suite of state-of-the-art hydrology and climate analysis tools to evaluate the sensitivity of Sudan's optimal hydropower and irrigation development pathways to hydrologic variability and climate change. Present day hydrologic conditions are derived from a gridded implementation of the Noah Land Surface Model (LSM) that includes representation of typical irrigation practices in the region. Noah is implemented using the NASA Land Information System (LIS), and draws forcing data from a combination of reanalysis and satellite meteorological products. Additional satellite inputs are used to provide a constraint on Noah evapotranspiration estimates and to acquire parameters such as crop water requirements that are crucial in determining yield and agricultural production. Future climate conditions are projected using statistical downscaling techniques trained to historical meteorological records and projected forward using inputs from the 5th Coupled Model Intercomparison Project (CMIP5) simulation database. These climatic and hydrologic inputs are combined with agronomic and economic inputs to drive an optimization model developed within the General Algebraic Modeling System (GAMS). By using output and results from climate, hydrologic and optimization models this research aims to show how these models can be integrated to aid decision makers in the quest to better manage their water resources.

Satti, S.; Zaitchik, B.; Siddiqui, S.

2013-12-01

142

Fatty acid composition of lipid-rich myctophids and mackerel icefish ( Champsocephalus gunnari ) - Southern Ocean food-web implications  

Microsoft Academic Search

The lipid content, fatty acid composition and calorific value of seven species of mesopelagic deep-sea fish of the family Myctophidae and the mackerel icefish, Champsocephalus gunnari, important in the diet of Southern Ocean marine predators, are presented. Fish were sampled at the Kerguelen Plateau (KP) and Macquarie Ridge (MR) in the Indian and Pacific sectors of the Southern Ocean respectively,

Mary-Anne Lea; Peter D. Nichols; Gareth Wilson

2002-01-01

143

Reworked planktonic Foraminifera from the Late Rupelian of the southern Upper Rhine Graben and their palaeogeographic and biostratigraphic implications  

NASA Astrophysics Data System (ADS)

During the Late Rupelian the widespread second transgression (corresponding to international Ru2-3 transgressions; BERGER et al. 2005) affected the whole Upper Rhine Graben basin and led to the deposition of the several hundred meters thick marine "Série grise". An abrupt transition (erosion surface) between the uppermost "Série grise" and Niederroedern Formation indicates the change to fluviatile and lacustrine conditions throughout the basin close to the Late Rupelian / Early Chattian boundary. Abundant reworked Middle to Late Cretaceous (e.g., Marginotruncana pseudolinneiana) and Late Paleocene to Late Eocene (e.g., Acarinina bullbrooki, Morozovella subbotinae, Turborotalia cocoaensis) ranging planktonic Foraminifera occur in the "Série Grise" and equivalent lithological units of the Upper Rhine Graben and the Mainz Basin (e.g., FISCHER 1965, PIRKENSEER 2007, SCHÄFER & KUHN 2004). At least Late Cretaceous, Ypresian, Lutetian and Priabonian ages of source sediments are indicated by the overlapping biostratigraphic ranges of the reworked specimens. Abundant reworked material first appears in the lower "Couches à Mélettes" and reaches its acme in the increasingly "Marnes à Cyrènes" (terminal "Série grise"). Only sparse records are documented from the subsequent terrestrial Niederroedern Formation. These reworking events are linked to intervals of increased clastic input throughout the "Série grise". The planktonic Foraminifera are proposed to be reworked from related alpine deposits (later Helvetikum?) via a northwards trending fluviatile system, as no autochthonous Cretaceous and Early to Middle Eocene marine sediments were deposited within the graben basin. Furthermore other possible source areas (e.g., Paris Basin) were either not connected to the Upper Rhine Graben or were not subject to erosion in the Late Rupelian. This accords with the proposition (ROUSSÉ 2006) of a vast northwards prograding delta-system that was located close to the southern margin of the Upper Rhine Graben. Reworked Mesozoic and Paleogene calcareous nannoplankton from the Upper Rhine Graben and the Mainz Basin confirms the data derived from planktonic Foraminifera. The existence of reworked planktonic Foraminifera influences the biostratigraphic interpretation of the assemblage ranges attributed to "Série grise" samples. Facultatively reworked planktonic Foraminifera as Subbotina utilisindex and Pseudohastigerina micra ranging from the Lutetian to the Late Rupelian should not be included in the biostratigraphic analyses, as the occurrences of these facultatively reworked species are always linked to those of exclusively Cretaceous and Eocene age. Therefore the age of the "Série grise" deposits at Allschwil-2 is most likely to be placed within the "Chiloguembelina cubensis - Globigerinella obesa / Globorotaloides variabilis"-assemblage range of Mid P20 to Final P21a, lasting considerably longer than the very short Mid P20 range based on the presence of Pseudohastigerina micra as "last occurrence"-marker (PIRKENSEER 2007). This study was funded by the Swiss National Science Foundation projects 109457 and 118025. References: BERGER, J.-P., REICHENBACHER, B., BECKER, D., et al. (2005): Eocene-Pliocene time scale and stratigraphy of the Upper Rhine Graben (URG) and the Swiss Molasse Basin (SMB). - International Journal of Earth Sciences, 94, 4: 711-731. FISCHER, H. (1965): Geologie des Gebietes zwischen Blauen und Pfirter Jura. - Beiträge zur geologischen Karte der Schweiz, NF 122: 106p. PIRKENSEER, C. (2007): Foraminifera, Ostracoda and other microfossils of the Southern Upper Rhine Graben - Palaeoecology, biostratigraphy, palaeogeography and geodynamic implications. - PhD thesis: 340p, Fribourg. ROUSSÉ, S. (2006): Architecture et dynamique des séries marines et continentales de ?Oligocène Moyen et Supérieur du Sud du Fossé Rhénan: Evolution des milieux de dépôt en contexte de rift en marge de ?avant-pays alpin.

Pirkenseer, C.; Spezzaferri, S.; Berger, J.-P.

2009-04-01

144

Sudan azo dyes and Para Red degradation by prevalent bacteria of the human gastrointestinal tract  

Microsoft Academic Search

Sudan azo dyes have genotoxic effects and ingestion of food products contaminated with Sudan I, II, III, IV, and Para Red could lead to exposure in the human gastrointestinal tract. In this study, we examined thirty-five prevalent species of human intestinal bacteria to evaluate their capacity to degrade Sudan dyes and Para Red. Among these tested bacterial strains, 23, 13,

Haiyan Xu; Thomas M. Heinze; Donald D. Paine; Carl E. Cerniglia; Huizhong Chen

2010-01-01

145

Effect of phosphomolybdic acid on the binding of Sudan black B  

Microsoft Academic Search

Paraffin sections of tissues fixed in absolute alcohol or Carnoy's fluid were mordanted in a 1% aqueous solution of phosphomolybdic acid, stained in saturated solutions of Sudan black B, acetylated Sudan black, various solvent and basic dyes in 70% ethyl alcohol for 5 min at room temperature, dehydrated in alcohol and covered in Permount. Sudan black B and other dyes

Holde Puchtler; Faye Sweat

1964-01-01

146

Paleogeographic evolution and paleoenvironmental reconstruction of the Sudd area during the Early-Mid Holocene, Sudan  

NASA Astrophysics Data System (ADS)

Sixty-five diatom species were identified from five localities within the top Umm Ruwaba Formation (namely Bara A, Bara B, Binaya, Sayal and Kosti). The recovered diatoms have been used here to confirm the existence of the so-called Lake Sudd, which once covered parts of central and southern Sudan, and lasted from 5.253 to 11.300 Ka B.P. The diatom assemblage indicates deposition in fresh to slightly saline water. The distribution of large-sized diatoms, noted within the study material, is attributed to the presence of spots characterized by high nutrition which correspond to the beach of the ancient lake. Integration of the paleontological results and remote sensing data permits the delineation of the lake boundary.

El Shafie, Abdel Gadir A. I.; Elsayed Zeinelabdein, Khalid A.; Eisawi, Ali A. M.

2011-04-01

147

VOLATILE ORGANIC COMPOUNDS FROM VEGETATION IN SOUTHERN YUNNAN PROVINCE, CHINA: EMISSION RATES AND SOME POTENTIAL REGIONAL IMPLICATIONS  

EPA Science Inventory

Little information is currently available regarding emissions of biogenic volatile organic compounds (BVOCs) in southern Asia. To address the need for BVOC emission estimates in regional atmospheric chemistry simulations, 95 common plant species were screened for emissions of BVO...

148

An outbreak of hepatitis E and high maternal mortality at Port Sudan, Eastern Sudan  

PubMed Central

During 4 months (November 2010–March 2011) of an outbreak of hepatitis E virus (HEV), 39 pregnant women presented at Port Sudan Hospital, Sudan, with various symptoms of viral hepatitis. The diagnosis of viral hepatitis was confirmed by serology using ELISA anti-HEV IgG and IgM. The mean (SD) maternal age and gestational age were 24.0 (4.2) years and 33.6 (3.7) weeks, respectively. Eight (20.5%) women were primigravidae. There were 11 (28.2%) maternal deaths, 14 (36.0%) intrauterine fetal deaths, and eight (20.5%) cases of postpartum haemorrhage. There were nine (23.0%) cases of preterm (<37 weeks of gestation) deliveries. Fulminant hepatitis with hepatic encephalopathy was the most common cause of death among these patients. Nine of these women died before delivery and the other two died immediately following the delivery due to severe haemorrhage. There were no significant differences in clinical and biochemical data between the women who died (11) and those who survived.

Rayis, Duria A; Jumaa, Ammar M; Gasim, Gasim I; Karsany, Mubark S; Adam, Ishag

2013-01-01

149

[Determination of dyes sudans in of raw foods].  

PubMed

The number of cases using of forbidden dyes (such as Sudan-I and Para Red) in European foodstuff (including foodstuff from Russia) were increased last time. In this case it was required to adapt existing analytical methods for the control of dyes Sudan I-IV and Para Red. It was used for this purpose high performance liquid chromatography with detectings on diode-array and MS detector. Sudan I and Para Red were detected in 3 foodstuffs from examined 49 products. Concentration levels of these dyes were varied from 3 up to 500 mg/kg. Limits of determination of the methods is: HPLC-diode-array--0.1 mg/kg and HPLC-MS--0.5 mg/kg. PMID:18368858

Bessonov, V V; Perederiaev, O I; Khromchenkova, E P; Vedishcheva, Iu V; Kulikova, O S

2008-01-01

150

Geochemical Characteristics of Volcanic Rocks from the Southern Okinawa Trough and its Implications for Tectono-magmatic Evolution  

NASA Astrophysics Data System (ADS)

The Okinawa Trough is a site of ongoing backarc rifting behind the Ryukyu arc-trench system. Recent intensive surveys, including submersible dives, at the southern Okinawa Trough (SOT) have revealed details of bathymetric, geological, and geophysical features. Here, we present the petrological and geochemical characteristics of volcanic rocks collected during these cruises, and discuss its relation to the evolutionary stage of rifting. Based on bathymetirc and magmatic features, SOT can be divided into two (i.e., eastern and western) segments with non-transform offset at ˜ 123.5° E. The eastern segment represents a well-developed rift system with E-W-trending central graben and separated NE-SW-trending volcanic front; these two features merge at ˜ 125° E. In contrast, the western segment is in the incipient rifting stage; rift axis exists close to 100 km contour of the Wadati-Benioff zone. The most notable feature is the presence of 'abnormal' volcanic chain (Cross Backarc Volcanic Trail, CBVT), which trends NE-SW and is obviously oblique to the axial trend. All rocks are subalkaline, but range from basalt to rhyolite; dacite-rhyolite are dominant in the eastern volcanic front and CBVT. Basalts from both segments are low-K tholeiites; they have high abundance of LILEs relative to HFSEs, negative Nb anomalies on MORB-normalized diagrams, and range of 143Nd/144Nd (0.5128-0.5129) and 87Sr/86Sr (0.7034-0.7048). Pb isotope systematics indicate 206Pb/204Pb=18.398-18.582, 207Pb/204Pb=15.594-15.652 and 208Pb/204Pb=38.570-38.912, clearly above the Northern Hemisphere Reference Line. These elemental and isotopic variations are compatible with derivation from Indian Ocean MORB-like mantle with strong overprint of subduction components from the slab. There is clear difference among more felsic rocks between two segments. At similar silica contents, most of felsic rocks from the western segment, including CBVT rhyolites, have higher LILE contents, 87Sr/86Sr and 208Pb/204Pb and lower 143Nd/144Nd; these feature can be explained by significant crustal contamination of mantle-derived magmas. On the other hand, the eastern segment felsic rocks have a similar range of Sr-Nd-Pb isotopes for basalts. We suggest that the marked spatial differences in geochemical characteristics of felsic rocks reflects different stage of the backarc rifting. Geophysical surveys provided evidence that crustal thickness is relatively thin ( ˜ 20km) under the eastern segment, whereas thick continental crust ( ˜ 25-30km) without significant thinning have been proposed in the western segment. Sibuet et al. (1998) proposed the linkage of subducted Gagua Ridge for CBVT rhyolites, because of a sharp change in subduction angle (slab tear?) near 123° E. The CBVT rhyolites are, however, not adakitic. Instead, we suggest mantle flow originated from the magmatism at the Northern Taiwan Volcanic Zone, which commenced since ˜ 3 Ma and was resulted from post-collisional extensional collapse, have important implications for required heat source and comparatively depleted mantle source inferred from mafic inclusion in CBVT rhyolites.

Shinjo, R.; Hokakubo, S.; Haraguchi, S.; Matsumoto, T.; Woodhead, J.

2003-12-01

151

Southern Peru desert shattered by the great 2001 earthquake: Implications for paleoseismic and paleo-El Nin??o-Southern Oscillation records  

USGS Publications Warehouse

In the desert region around the coastal city of Ilo, the great southern Peru earthquake of June 23, 2001 (8.2-8.4 moment magnitude), produced intense and widespread ground-failure effects. These effects included abundant landslides, pervasive ground cracking, microfracturing of surficial hillslope materials, collapse of drainage banks over long stretches, widening of hillside rills, and lengthening of first-order tributary channels. We have coined the term "shattered landscape" to describe the severity of these effects. Long-term consequences of this landscape shattering are inferred to include increased runoff and sediment transport during postearthquake rainstorms. This inference was confirmed during the first minor postearthquake rainstorm there, which occurred in June and July of 2002. Greater amounts of rainfall in this desert region have historically been associated with El Nin??o events. Previous studies of an unusual paleoflood deposit in this region have concluded that it is the product of El Nin??o-generated precipitation falling on seismically disturbed landscapes. The effects of the 2001 earthquake and 2002 rainstorm support that conclusion.

Keefer, D. K.; Moseley, M. E.

2004-01-01

152

Southern Peru desert shattered by the great 2001 earthquake: Implications for paleoseismic and paleo-El Ni?o-Southern Oscillation records  

PubMed Central

In the desert region around the coastal city of Ilo, the great southern Peru earthquake of June 23, 2001 (8.2–8.4 moment magnitude), produced intense and widespread ground-failure effects. These effects included abundant landslides, pervasive ground cracking, microfracturing of surficial hillslope materials, collapse of drainage banks over long stretches, widening of hillside rills, and lengthening of first-order tributary channels. We have coined the term “shattered landscape” to describe the severity of these effects. Long-term consequences of this landscape shattering are inferred to include increased runoff and sediment transport during postearthquake rainstorms. This inference was confirmed during the first minor postearthquake rainstorm there, which occurred in June and July of 2002. Greater amounts of rainfall in this desert region have historically been associated with El Niño events. Previous studies of an unusual paleoflood deposit in this region have concluded that it is the product of El Niño-generated precipitation falling on seismically disturbed landscapes. The effects of the 2001 earthquake and 2002 rainstorm support that conclusion.

Keefer, David K.; Moseley, Michael E.

2004-01-01

153

Crustal structure beneath southern Africa and its implications for the formation and evolution of the Kaapvaal and Zimbabwe cratons  

Microsoft Academic Search

The formation of Archean crust appears to involve processes unique to early earth history. Initial results from receiver function analysis of crustal structure beneath 81 broadband stations deployed across southern Africa reveal significant differences in the nature of the crust and the crust-mantle boundary between Archean and post-Archean geologic terranes. With the notable exception of the collisional Limpopo belt, where

T. K. Nguuri; J. Gore; D. E. James; S. J. Webb; C. Wright; T. G. Zengeni; O. Gwavava; J. A. Snoke

2001-01-01

154

Estimate of the Potential Adoption of Genetically Modified Cotton by Farmers in Southern Spain and its Economic Implications  

Microsoft Academic Search

This paper analyses the potential adoption and economic on-farm impact of Bt cotton in the Andalusia region (southern Spain). Survey data have shown that, on average, 58% of the responding farmers know about genetically modified (GM) cotton. Another outcome of the survey is that 95% of the farmers declaring that they know about GM cotton would be willing to grow

Manuel Gomez-Barbero; Emilio Rodgriguez-Cerezo

2005-01-01

155

Late Holocene Marsh Expansion in Southern San Francisco Bay, California: Implications for the Use of Historic Baselines as Restoration Targets  

EPA Science Inventory

Currently, the largest tidal wetlands restoration project on the US Pacific Coast is being planned and implemented in southern San Francisco Bay; however, knowledge of baseline conditions of salt marsh extent in the region prior to European settlement is limited. Here, analysis o...

156

Paleomagnetic directional dispersion produced by plastic deformation in a thick Miocene welded tuff, southern Nevada: Implications for welding temperatures  

Microsoft Academic Search

Two voluminous rhyolitic to quartz-latitic ash flow sheets, the Tiva Canyon and Topopah Spring members of the Paintbrush Tuff, were erupted from the Miocene Claim Canyon cauldron in southern Nevada. Although lithologically similar, these units differ greatly in their recording of the ancient geomagnetic field. The reversely magnetized Tiva Canyon Member yields remanent directions that are well grouped both within

J. G. Rosenbaum

1986-01-01

157

Habitat Associations of Hypogeous Fungi in the Southern Appalachians: Implications for the Endangered Northern Flying Squirrel (Glaucomys sabrinus coloratus)  

Microsoft Academic Search

gporocarps of hypogeous mycorrhizal fungi (truffles) are the major food of northern flying squirrels (Gluucomys satinus). The two subspecies of northern flying squir- rels that occur in the southern Appalachians, G. s. colmatus and G. s. fuscus, are endangered species which are primarily found in the ecotone between high-elevation spruce-fir and northern hardwood forests. Our objective was to determine the

SUSAN C. LOEB; FRANK H. TAINTER; EFREN CÁZARES

2000-01-01

158

The dynamics of grape leafhopper Empoasca vitis Göthe populations in southern Switzerland and the implications for habitat management  

Microsoft Academic Search

The life cycle of Empoasca vitis and its most important parasitoid Anagrus atomus in southern Switzerland can be divided into three phases. In phase I the adults of E. vitis move from overwintering sites, i.e. primarily conifers, over deciduous plants into the vineyards. The parasitoid A. atomus on the other hand, appears to overwinter in leafhopper eggs, mainly on roses

F. Cerutti; J. Baumgärtner; V. Delucchi

1991-01-01

159

Paleoclimatic implications (Late Cretaceous–Paleogene) from micromorphology of calcretes, palustrine limestones and silcretes, southern Paraná Basin, Uruguay  

Microsoft Academic Search

Sedimentologic and petrographic analyses of outcroping and subsurface calcretes, palustrine carbonates, and silcretes were carried out in the southern Paraná Basin (Uruguay). The aim of this work is to describe the microfabric and interpret the genesis of these rocks through detailed analyses, since they contain significant paleoenvironmental and paleoclimatic evolution information.The main calcrete and silcrete host rock (Mercedes Formation) is

Ofelia R. Tófalo; Pablo J. Pazos

2010-01-01

160

Tectonic setting and regional implications ofca2.2 Ga mafic magmatism in the southern Hamersley Province, Western Australia  

Microsoft Academic Search

Although the presence of post-Hamersley Group mafic intrusive and extrusive rocks in the southern Hamersley province of Western Australia has been known since the area was first mapped in the early 1960s, details of the age, tectonic setting and significance of these rocks have only recently been determined, and are still controversial. These rocks are most commonly interpreted as the

D. Mcb. Martin; P. A. Morris

2010-01-01

161

Triggering of 1812 Santa Barbara earthquake by a great San Andreas shock: Implications for future seismic hazards in southern California  

Microsoft Academic Search

We study the evolution of the stress field over the last 200 years in southern California using the stress buildup associated with major faults and stress drops associated with great earthquakes. In this report we calculate the change in the Coulomb Failure Function (DeltaCFF) associated with the great Wrightwood earthquake of Dec. 8, 1812 on the San Andreas fault for

Jishu Deng; Lynn R. Sykes

1996-01-01

162

Evidence for and implications of sedimentary diapirism and mud volcanism in the southern Utopia highland–lowland boundary plain, Mars  

Microsoft Academic Search

Several types of spatially associated landforms in the southern Utopia Planitia highland–lowland boundary (HLB) plain appear to have resulted from localized geologic activity, including (1) fractured rises, (2) elliptical mounds, (3) pitted cones with emanating lobate materials, and (4) isolated and coalesced cavi (depressions). Stratigraphic analysis indicates these features are Hesperian or younger and may be associated with resurfacing that

James A. Skinner; Kenneth L. Tanaka

2007-01-01

163

Insecticide resistance in Anopheles arabiensis in Sudan: temporal trends and underlying mechanisms  

PubMed Central

Background Malaria vector control in Sudan relies mainly on indoor residual spraying (IRS) and the use of long lasting insecticide treated bed nets (LLINs). Monitoring insecticide resistance in the main Sudanese malaria vector, Anopheles arabiensis, is essential for planning and implementing an effective vector control program in this country. Methods WHO susceptibility tests were used to monitor resistance to insecticides from all four WHO-approved classes of insecticide at four sentinel sites in Gezira state over a three year period. Insecticide resistance mechanisms were studied using PCR and microarray analyses. Results WHO susceptibility tests showed that Anopheles arabiensis from all sites were fully susceptible to bendiocarb and fenitrothion for the duration of the study (2008–2011). However, resistance to DDT and pyrethroids was detected at three sites, with strong seasonal variations evident at all sites. The 1014 F kdr allele was significantly associated with resistance to pyrethroids and DDT (P??7 in allelic tests). The 1014S allele was not detected in any of the populations tested. Microarray analysis of the permethrin-resistant population of An. arabiensis from Wad Medani identified a number of metabolic genes that were significantly over-transcribed in the field-collected resistant samples when compared to the susceptible Sudanese An. arabiensis Dongola strain. These included CYP6M2 and CYP6P3, two genes previously implicated in pyrethroid resistance in Anopheles gambiae s.s, and the epsilon-class glutathione-S-transferase, GSTe4. Conclusions These data suggest that both target-site mechanisms and metabolic mechanisms play an important role in conferring pyrethroid resistance in An. arabiensis from Sudan. Identification in An. arabiensis of candidate loci that have been implicated in the resistance phenotype in An. gambiae requires further investigation to confirm the role of these genes.

2014-01-01

164

Crustal strain rates, upper mantle seismic wave speeds, and implications for lower crustal strength in southern California  

NASA Astrophysics Data System (ADS)

In southern California the dilatational strain rate field of the crust imaged using GPS geodesy is strongly correlated with upper mantle wave speeds imaged using Rayleigh wave tomography. This correlation suggests that small-scale upper mantle convection may be actively contributing to upper crustal deformation. Understanding this correlation is important for determining whether geodesy has a role to play in advancing our understanding of upper mantle dynamics, and for improving tectonic interpretations of crustal motion data, particularly with regard to hazards assessment. To study this issue further, we developed an analytical model in which a viscoelastic crust is driven by tractions induced by negatively buoyant cylinders sinking in a viscous mantle halfspace. This model may serve as a numerical analog for delaminated crustal roots or lithospheric mantle drips. For models in which the crust is composed of a single viscoelastic layer with viscosity that is higher than that of the upper mantle, we found that tractions on the base of the crust associated with Stokes-like flow may result in horizontal motions of the crustal surface of order 1 mm/yr or more over distances of as small as 50 km (strain rates of order 20 nanostrain/yr), depending on crustal thickness, cylinder size and density contrast, and crust and mantle viscosities. These strain rates are comparable to the dilatational strain rates observed in southern California. For models in which the lower crust behaves as a weak, low viscosity layer sandwiched between stronger upper crust and mantle, the horizontal components of upper crust are decoupled from mantle flow. Thus, the geodetic strain rate and seismic tomography data for southern California may suggest that the lower crust of southern California is relatively strong. This inference is consistent with long-time scale rheologic properties recently inferred by other researchers from short-time scale postseismic deformation data for the southern California region.

Bennett, R. A.; Venkataramani, S.; Mcelwaine, J. N.; Restrepo, J. M.

2012-12-01

165

Base- and precious-metal deposits in the Basin and Range of Southern California and Southern Nevada—Metallogenic implications of lead isotope studies  

NASA Astrophysics Data System (ADS)

Southern California and southern Nevada contain abundant lead-zinc deposits with strikingly different characteristics. On the west, the Darwin Terrane contains abundant Jurassic and Cretaceous intrusions surrounded by lead-zinc skarn and replacement deposits rich in pyrite and manganese minerals. The Tecopa Terrane is east of the Darwin Terrane and contains some lead deposits that are hosted by the Proterozoic Noonday Dolomite. These lead deposits have no consistent relation to igneous rocks; they contain mainly galena, and are devoid of pyrite and manganese minerals. Other skarn and vein deposits in the Ivanpah and Tecopa districts are more closely associated with igneous rocks. Mississippi Valley type lead-zinc deposits are present still farther to the east in the Goodsprings Terrane in Nevada. These deposits are hosted by breccias formed below the Mississippian-Pennsylvanian unconformity and are unrelated to igneous rocks. Deposits in the Darwin Terrane have lead isotopic signatures that lie along a mantle-sediment mixing line indicating that they formed in a continental arc setting analogous to that for the plutons in the Sierra Nevada batholith [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Encroachment of this continental arc on the North American continent in the eastern part of the Darwin Terrane resulted in a lead isotopic signature that is like that of the strongly contaminated plutons [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Many deposits from the Inyo Mountains on east side of the Owens Valley have lead isotopic signatures that reflect this encroachment. To the east in the Tecopa Terrane, encroachment of the continental arc on the Mojave crust resulted in partial melting of 1.7 Ga amphibolite and granulite facies rocks to produce the plutons and mineral deposits associated with plutons in this terrane. Lead from deposits in this terrane hosted in the Proterozoic Noonday Dolomite and associated rocks have a lead isotope signature that reflects hydrothermal circulation of fluids in the Mojave supracrustal rocks. The boundary between the Darwin Terrane and the Tecopa Terrane lies just west of the Ash Valley-Panamint Range Fault and is bounded by the Towne Fault on the north and the Garlock Fault on the south. Lead isotopic data from the Goodsprings district in southwestern Nevada, east of the Tecopa Terrane, form a 1.45 Ga linear array that is indicative of Mississippi Valley type mineralization. Although we have no independent evidence of the timing of the tectonic events that formed these deposits, it is likely that all formed as a result of the Mesozoic collision of the Panthalassen crust with the North American continent.

Church, Stanley E.; Cox, Dennis P.; Wooden, Joseph L.; Tingley, Joseph V.; Vaughn, Robert B.

2005-12-01

166

Base- and precious-metal deposits in the Basin and Range of Southern California and Southern Nevada - Metallogenic implications of lead isotope studies  

USGS Publications Warehouse

Southern California and southern Nevada contain abundant lead-zinc deposits with strikingly different characteristics. On the west, the Darwin Terrane contains abundant Jurassic and Cretaceous intrusions surrounded by lead-zinc skarn and replacement deposits rich in pyrite and manganese minerals. The Tecopa Terrane is east of the Darwin Terrane and contains some lead deposits that are hosted by the Proterozoic Noonday Dolomite. These lead deposits have no consistent relation to igneous rocks; they contain mainly galena, and are devoid of pyrite and manganese minerals. Other skarn and vein deposits in the Ivanpah and Tecopa districts are more closely associated with igneous rocks. Mississippi Valley type lead-zinc deposits are present still farther to the east in the Goodsprings Terrane in Nevada. These deposits are hosted by breccias formed below the Mississippian-Pennsylvanian unconformity and are unrelated to igneous rocks. Deposits in the Darwin Terrane have lead isotopic signatures that lie along a mantle-sediment mixing line indicating that they formed in a continental arc setting analogous to that for the plutons in the Sierra Nevada batholith [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Encroachment of this continental arc on the North American continent in the eastern part of the Darwin Terrane resulted in a lead isotopic signature that is like that of the strongly contaminated plutons [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Many deposits from the Inyo Mountains on east side of the Owens Valley have lead isotopic signatures that reflect this encroachment. To the east in the Tecopa Terrane, encroachment of the continental arc on the Mojave crust resulted in partial melting of 1.7 Ga amphibolite and granulite facies rocks to produce the plutons and mineral deposits associated with plutons in this terrane. Lead from deposits in this terrane hosted in the Proterozoic Noonday Dolomite and associated rocks have a lead isotope signature that reflects hydrothermal circulation of fluids in the Mojave supracrustal rocks. The boundary between the Darwin Terrane and the Tecopa Terrane lies just west of the Ash Valley-Panamint Range Fault and is bounded by the Towne Fault on the north and the Garlock Fault on the south. Lead isotopic data from the Goodsprings district in southwestern Nevada, east of the Tecopa Terrane, form a 1.45 Ga linear array that is indicative of Mississippi Valley type mineralization. Although we have no independent evidence of the timing of the tectonic events that formed these deposits, it is likely that all formed as a result of the Mesozoic collision of the Panthalassen crust with the North American continent. ?? 2005 Elsevier B.V. All rights reserved.

Church, S. E.; Cox, D. P.; Wooden, J. L.; Tingley, J. V.; Vaughn, R. B.

2005-01-01

167

Leishmaniasis in the Sudan Republic. 30. Epidemiologic Report.  

National Technical Information Service (NTIS)

Kala azar was first found in the Sudan in 1904 only a year after the disease was discovered and described in Algeria. This final report includes the following: Findings in the Paloich-Malakal Area; vector studies, man-biting sandflies, infections with Lei...

H. Hoogstraal D. Heyneman

1969-01-01

168

Desertification in the Sudan: causes, effects and policy options  

Microsoft Academic Search

Desertification is the spread of desert-like conditions in arid and semi-arid conditions. It is a result of pressure from both climatic and human factors. Desertification in the Sudan has been accelerating at a faster rate over the last two decades, leading to marginalization and the loss of arable land. The main factors contributing to desertification include drought, population growth, the

S. L. Laki

1994-01-01

169

Mineral Composition of Renal Stones from the Sudan  

Microsoft Academic Search

Urolithiasis is a very frequent finding in the Sudan, but stone analysis is not routinely performed in this country. It would, however, give important evidence for the metabolic basis of stone formation. We therefore set out to analyze urinary stones in 80 Sudanese patients (45 male, 35 female), 12 of whom where children. Fourier-transformed infrared spectroscopy was used for stone

A. A. Balla; A. M. Salah; A. H. H. Khattab; A. Kambal; D. Bongartz; B. Hoppe; A. Hesse

1998-01-01

170

Rainfed mechanized farming and deforestation in central Sudan  

Microsoft Academic Search

Sudan is threatened by a serious deforestation problem. Total forested area decreased by about 20 percent over the last two decades, largely as a result of the expansion of rainfed mechanized farming (RMF). To safeguard against the problems of deforestation, the government's Mechanized Farming Corporation requires each farmer to leave at least ten percent of the total farm area under

Abdelmoneim Hashim Elnagheeb; Daniel W. Bromley

1992-01-01

171

Tertiary age for upper Nubian sandstone formation, central Sudan  

SciTech Connect

In central and northern Sudan, oil exploration is now active in the basins containing sediments of the Nubian Sandstone Formation. On the evidence of planned pipeline construction, significant volumes of oil appear to have been discovered in southwestern Sudan. A newly discovered flora from the upper Nubian Sandstone Formation near Khartoum in central Sudan is Tertiary in age. The flora is well preserved, and comprises leaves, flowers, and fruits, many not yet described. At the generic level, they are comparable to forms that are known fro the Eocene to Miocene. Aquatic plants indicate a lacustrine paleoenvironment; humid tropical forests thrived on the lakeshores. The Nubian Sandstone Formation of Sudan had been considered to be entirely of Cretaceous age; this new flora shifts the upper boundary into the Tertiary. The Tertiary Hudi Chert, found in scattered outcrops in the region of Atbara, was considered to overlie the Nubian Sandstone Formation. The authors suggest that the Hudi Chert is partly age equivalent to the Tertiary upper Nubian Sandstone at Jebel Mudaha.

Prasad, G.; Lejal-Nicol, A.; Vaudois-Mieja, N.

1986-02-01

172

The Role of Education in Sudan's Civil War  

ERIC Educational Resources Information Center

This article addresses the role that education plays in conflict, with specific reference to the civil war in Sudan. It analyses the ideological basis of the Sudanese government (GoS) during the civil war, with special reference to the role of religion and ethnicity. It shows how the primary education system was based on the Islamist ideology of…

Breidlid, Anders

2013-01-01

173

UPLC-ESI-MS/MS analysis of Sudan dyes and Para Red in food.  

PubMed

An analytical method for the simultaneous determination of Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B and Sudan IV) and Para Red in food by ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. Samples were extracted with acetonitrile, and water added into the extract. The supernatant was analysed by UPLC-MS/MS after refrigeration and centrifugation. The sample was separated on an Acquity BEH C(18) column, and detected by MS/MS with the multiple reaction monitoring mode. Matrix calibration was used for quantitative testing of the method. The linear matrix calibrations of Sudan dyes and Para Red were 2-50 and 10-250 ng g(-1), respectively, and the regression coefficients were >0.9945. The recoveries were 83.4-112.3% with good coefficients of variation of 2.0-10.8%. The limits of detection were between 0.3 and 1.4 ng g(-1) for the six Sudan dyes, and between 3.7 and 6.0 ng g(-1) for Para Red. The limits of quantification were between 0.9 and 4.8 ng g(-1) for the six Sudan dyes, and between 12.2 and 19.8 ng g(-1) for Para Red. PMID:20582780

Li, C; Wu, Y L; Shen, J Z

2010-09-01

174

Development and in-house validation of a liquid chromatography-electrospray-tandem mass spectrometry method for the simultaneous determination of Sudan I, Sudan II, Sudan III and Sudan IV in hot chilli products.  

PubMed

An accurate method based on the use of reversed-phase (RP) liquid chromatography-tandem mass spectrometry interfaced with electrospray (LC-ESI-MS/MS) was devised for the determination of Sudan I, Sudan II, Sudan III and Sudan IV in hot chilli food samples. A simple sample treatment procedure entailing the use of an extraction step with acetone without clean-up was developed. A C18 column with an aqueous formic acid/methanol mixture as the mobile phase was used under isocratic conditions. Mass spectral acquisition was done in positive ion mode by applying selected reaction monitoring of three fragmentation transitions per compound to provide a high degree of selectivity. The method was in-house validated in terms of detection limits (LOD), quantitation limits (LOQ), linearity, sensitivity, accuracy, recovery, and selectivity on two kinds of hot chilli sauces. Good results in the low ng/g level were obtained for LOD and LOQ of all analytes in matrices. Under both intra-day repeatability (R.S.D. between 1 and 13%) and intermediate precision (about 5-15% R.S.D. for both chilli sauce matrices) conditions, precision proved to be typical of determinations based on electrospray LC-MS and acceptable for routine monitoring purposes. Extraction recoveries for all four azo-dyes in chilli tomato sauce ranged from 92 to 103% at a spiking level of 5 microg/kg, whereas values between 72 and 97% were calculated in chilli tomato and cheese sauce at the same concentration level. The applicability of the method to the determination of Sudan azo-dyes in hot chilli products was demonstrated. PMID:15296396

Calbiani, F; Careri, M; Elviri, L; Mangia, A; Pistarà, L; Zagnoni, I

2004-07-01

175

Paleomagnetism, rock magnetism and opaque mineralogy of iron ore deposits from southern Mexico and their implications for quantitative modelling of magnetometric data  

SciTech Connect

Paleomagnetism, Rock Magnetism and Opaque Mineralogy of Iron Ore Deposits from Southern Mexico and Their Implications for Quantitative Modelling of Magnetometric Data. The tectonic history of the Pacific continental margin is critical for understanding their mineral deposits. The margin presents intrusive and volcanic activity characteristic of magmatic arcs of subduction zones, which are genetically related with deposits of Cu, Fe, Mo, Au, and Ag. Although the tectonic history has been complex, involving oblique plate subduction, lateral movements, accretion of magmatic arcs and oceanic plateaux, and lateral displacements of major blocks, the mineral deposits are spatially distributed along elongated belts that roughly follow the margin. The authors have conducted paleomagnetic, rock magnetic, and petrological studies of the iron ore deposits to investigate genesis, magnetic mineralogy, stratigraphic relationships, metamorphism, and applications on quantitative modelling of magnetometric data. The remanent magnetization and susceptibility data are necessary for interpretation of magnetic anomalies. The results permit a comparison of the mineral deposits along the continental margin.

Alva-Valdivia, L.M.; Fucugauchi, Urrutia, J.; Bohnel, H.; Moran Zenteno, D.J. (Universidad Nacional Autonoma de Mexico, Mexico City (Mexico))

1990-06-01

176

Foot and mouth disease in the Borana pastoral system, southern Ethiopia and implications for livelihoods and international trade  

Microsoft Academic Search

Participatory epidemiology (PE) was used on the Borana plateau of southern Ethiopia to understand pastoralist’s perceptions\\u000a of the clinical and epidemiological features of foot and mouth disease (FMD) in cattle. Matrix scoring showed good agreement\\u000a between informant groups on the clinical signs of acute and chronic FMD, and findings were cross-checked by clinical examination\\u000a of cattle and assessment of previous

T. Rufael; A. Catley; A. Bogale; M. Sahle; Y. Shiferaw

2008-01-01

177

A geochemical survey of spring water from the main Ethiopian rift valley, southern Ethiopia: implications for well-head protection  

Microsoft Academic Search

The report discusses the stable isotope values and major solute compositions of 16 springs and river-water samples along a topographic gradient in the main rift valley of southern Ethiopia. Most of the springs used for drinking water supplies discharge from local flow systems at scales of only tens of meters. The delta18O and deltaD values of waters unaffected by shallow

Jeffrey M. McKenzie; Donald I. Siegel; D. Jonathan McKenzie

2001-01-01

178

Geometry, kinematics and deformation rates along the active normal fault system in the southern Apennines: Implications for fault growth  

NASA Astrophysics Data System (ADS)

Throw rates, throws and kinematic data have been collected from a localised system of active normal faults in the southern Apennines, Italy, to assess how its growth history differs from that for a distributed fault system in the central Apennines. Both show evidence for fault interaction in that (1) faults located centrally along strike have higher throws and throw rates than distal faults, and (2) cumulative throw and throw-rate profiles summed across strike show central maxima with values decreasing to zero at fault system tips. However, although throw rates increased through time in the central Apennines, we are unable to resolve such changes if they exist for the southern Apennines. Specifically, throw rates derived from offsets of 18 ka geomorphic surfaces are consistent with total throws in the southern Apennines when extrapolated back through time, but overestimate total throws in the central Apennines by a factor of 2.4, suggesting an increase in throw-rate through time for the latter. We discuss why some fault systems appear to have throw rates that are constant through time whilst others accelerate during growth/interaction.

Papanikolaou, Ioannis D.; Roberts, Gerald P.

2007-01-01

179

Evidence for a Nascent Rift in South Sudan: Westward Extension of the East African Rift System?  

NASA Astrophysics Data System (ADS)

Joint inversion of seismic and gravity data of eastern Africa reveals a low seismic wave velocity arm stretching from the southern Main Ethiopian rift westward in an east-west direction that has not been noticed in earlier work. The zone of low velocities is located in the upper mantle and is not overlain by a known structural rift expression. We analyzed the local pattern of seismicity and the stresses in the African plate to interpret this low velocity arm. The zone of low velocities is located within the Central African Fold Belt, which dissects the northern and southern portions of the African continent. It is seismically active with small to intermediate sized earthquakes occurring in the crust. Seven earthquake solutions indicate (oblique) normal faulting and low-angle normal faulting with a NS to NNW-SSE opening direction, as well as strike-slip faulting. This pattern of deformation is typically associated with rifting. The present day stress field in northeastern Africa reveals a tensional state of stress at the location of the low velocity arm with an opening direction that corresponds to the earthquake data. We propose that the South Sudan low velocity zone and seismic center are part of an undeveloped, nascent rift arm. The arm stretches from the East African Rift system westward.

Maceira, M.; Van Wijk, J. W.; Coblentz, D. D.; Modrak, R. T.

2013-12-01

180

Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes  

NASA Astrophysics Data System (ADS)

Absorption and fluorescence spectra of three Sudan dyes (SudanIII, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800 nm, at room temperature. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. Furthermore, analyze of solvent-solute interactions and value of ground and excited states dipole moments suggests different forms of resonance structures for Sudan dyes in polar and low-polar solvents.

Zakerhamidi, M. S.; Golghasemi Sorkhabi, Sh.; Shamkhali, A. N.

2014-06-01

181

Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes.  

PubMed

Absorption and fluorescence spectra of three Sudan dyes (SudanIII, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800nm, at room temperature. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. Furthermore, analyze of solvent-solute interactions and value of ground and excited states dipole moments suggests different forms of resonance structures for Sudan dyes in polar and low-polar solvents. PMID:24637272

Zakerhamidi, M S; Golghasemi Sorkhabi, Sh; Shamkhali, A N

2014-06-01

182

Towards a kala azar risk map for Sudan: mapping the potential distribution of Phlebotomus orientalis using digital data of environmental variables.  

PubMed

The need to define the geographical distribution of Phlebotomus orientalis results from its importance as the dominant vector of kala azar (visceral Iceishmaniasis) in Sudan. Recent epidermics of this disease in southern and eastern Sudan caused an estimated 100000 deaths and have renewed the impetus for defining the ecological boundaries of the vector. This information is an essential prerequisite to the production of a risk map for kala azar. This study uses data on the presence and absence of P. orientalis from 44 collecting sites across the central belt of Sudan. A logistic regression model was used to estimate the probability of the presence of P. orientalis at each collecting site as a function of climatic and environmental variables (rainfall; temperature; altitude; soil type and the satellite-derived environmental proxies - Normalized Difference Vegetation Index and Land Surface Temperature). The logistic regression model indicates mean annual maximum daily temperature and soil type as the most important ecological determinants of P. orientalis distribution. An initial risk map was created in a raster-based geographical information system which delineates the area where P. orientalis may occur. This map was then refined using a mask layer indicating the known rainfall-based boundaries of the distribution of Acacia-Balanites woodland - a woodland type known to be associated with the distribution of this vector. The predictive performance of the risk map is discussed. PMID:10206264

Thomson, M C; Elnaiem, D A; Ashford, R W; Connor, S J

1999-02-01

183

Paleomagnetism of an east-west transect across the Cascade arc in southern Washington: Implications for regional tectonism  

USGS Publications Warehouse

Paleomagnetic data from a transect across the Cascade arc in southern Washington were collected to test models of vertical axis rotations for this part of the Pacific Northwest and to provide information on the tectonic history of the St. Helens seismic zone. The 75 site-mean directions are divided into three groups based on isotopic, fission track, and stratigraphic ages. Group 1 consists of samples from rocks deposited between 39 and 30 Ma and shows a mean clockwise vertical axis rotation of 34?? ?? 13??, group 2 consists of samples from rocks deposited be-tween 30 and 24 Ma and shows a mean clockwise rotation of 17?? ?? 11??, and group 3 consists of samples from rocks between 24 and 16 Ma and shows a mean clockwise rotation of 20?? ?? 12??. Although these three values of rotation are statistically indistinguishable at the 95% confidence level, we interpret them in combination with other data to indicate differential rotation across the St. Helens seismic zone (SHZ). The available paleomagnetic data for Eocene-Oligocene rocks west of the seismic zone show clockwise vertical axis rotations of 30?? ?? 8?? and 35?? ?? 9?? consistent with the value for group 1. The rotational values for groups 2 and 3 and the intrusive suite of Kidd Creek (13 Ma), despite their different ages, have similar values east of the SHZ. Comparing these groups of data east and west of the seismic zone indicates a differential rotation of 10?? ?? 3?? across it. In addition, the rates of rotation in southern Washington are similar to those for rocks in the western Cascades of Oregon and indicate that rotational deformation of Miocene age extends northward into southern Washington and eastward into the axis of the arc.

Hagstrum, J. T.; Swanson, D. A.; Evarts, R. C.

1999-01-01

184

Paleomagnetic results from the Cambrian and Ordovician sediments of Bornholm (Denmark) and Southern Sweden and paleogeographical implications for Baltica  

NASA Astrophysics Data System (ADS)

If apparent polar wander paths (APWP) cross, the question arises how to prove the older magnetization to be primary and not just a younger overprint. This problem is typically met in areas affected by percolating mineralizing fluids and/or heating due to a younger regional igneous activity. The Permian magnetic overprint is the classical example. Earlier paleomagnetic studies over the Lowermost Cambrian Nekso Sandstone Fm (NSF) of Bornholm (Denmark) yielded a characteristic remanent magnetization (ChRM) similar to the Permian directions for Baltica. Since a possible reason could be a chemical overprint, we checked whether this phenomenon did take place on a regional scale. Some samples therefore were collected from other Lower Cambrian clastics of Bornholm and Southern Scandinavia. In result we show that the well-grouped and stable ChRM of the NSF contrasts with fairly chaotic, soft, and badly preserved magnetizations of the Balka, Hardeberga, Mickwitzia, and Lingulid sandstones of Bornholm and Southern Sweden, thus not indicating widespread paleomagnetic overprint. We demonstrate that the ChRM of the NSF is most probably of syndepositional/early diagenetic origin and its similarity to the Permian direction for Baltica is only casual. We propose a normal polarity and a near-equatorial position on the Southern Hemisphere for Baltica in the early Cambrian time, as well as a more complicated trend of the APWP for this paleocontinent than envisaged by other authors. Paleomagnetic results from the Arenigian limestones of the Laesaa Formation (Bornholm) that yield excellently defined but most probably only secondary components are also presented.

Lewandowski, Marek; Abrahamsen, Niels

2003-11-01

185

The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography  

PubMed Central

Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised.

Rogers, Alex D.; Tyler, Paul A.; Connelly, Douglas P.; Copley, Jon T.; James, Rachael; Larter, Robert D.; Linse, Katrin; Mills, Rachel A.; Garabato, Alfredo Naveira; Pancost, Richard D.; Pearce, David A.; Polunin, Nicholas V. C.; German, Christopher R.; Shank, Timothy; Boersch-Supan, Philipp H.; Alker, Belinda J.; Aquilina, Alfred; Bennett, Sarah A.; Clarke, Andrew; Dinley, Robert J. J.; Graham, Alastair G. C.; Green, Darryl R. H.; Hawkes, Jeffrey A.; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A. I.; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D. K.; Roterman, Christopher N.; Sweeting, Christopher J.; Thatje, Sven; Zwirglmaier, Katrin

2012-01-01

186

Molecularly imprinted solid phase extraction for detection of sudan I in food matrices  

Microsoft Academic Search

Sudan I is a synthetic azoic dye employed as an additive in foods, and in particularly in those containing chilli powders, because of his intense red–orange colour. Now European Community does not allow “Sudan I” as an additive in foods because of its demonstrated cancerogenity.Several methods were developed to detect the presence of this compound (HPLC, GC\\/MS). However when “Sudan

Francesco Puoci; Carmelo Garreffa; Francesca Iemma; Rita Muzzalupo; Umile Gianfranco Spizzirri; Nevio Picci

2005-01-01

187

Geochemistry of basalts from the Dumisseau Formation, southern Haiti: implications for the origin of the Caribbean Sea crust  

Microsoft Academic Search

Basalt and diabase from the Cretaceous Dumisseau Formation, southern Haiti have Mg-numbers of 43-63, TiO2 contents of 1.6-3.9% and La abundances of 3.6-15.3 ppm. La\\/Ta ratios average 10, and indicate that the basalts are oceanic in character, distinct from the arc associations forming the northern part of Haiti. Oldest lavas have low TiO2 (1.6%) and are LREE-depleted, similar to N-MORBs,

Gautam Sen; Rosemary Hickey-Vargas; David Guy Waggoner; Florentin Maurrasse

1988-01-01

188

Analysis of Para Red and Sudan Dyes in Egg Yolk by UPLC–MS–MS  

Microsoft Academic Search

Matrix solid-phase dispersion (MSPD) with alumina N as adsorbent has been used for extraction of para red, Sudan 1, Sudan\\u000a 2, Sudan 3, and Sudan 4 dyes from egg yolk. The extracts were analyzed by ultra-performance liquid chromatography–tandem mass\\u000a spectrometry (UPLC–MS–MS). Mean recovery for the five dyes ranged from 63.2 to 98.6%, with CV 0.55–10.00%. One sample was\\u000a confirmed to

Xiaolin Hou; Yonggang Li; Shoujun Cao; Zhongwen Zhang; Yongnin Wu

2010-01-01

189

Sudan azo dyes and Para Red degradation by prevalent bacteria of the human gastrointestinal tract.  

PubMed

Sudan azo dyes have genotoxic effects and ingestion of food products contaminated with Sudan I, II, III, IV, and Para Red could lead to exposure in the human gastrointestinal tract. In this study, we examined thirty-five prevalent species of human intestinal bacteria to evaluate their capacity to degrade Sudan dyes and Para Red. Among these tested bacterial strains, 23, 13, 33, 30, and 29 out of 35 species tested were able to reduce Sudan I, II, III, IV, and Para Red, respectively, to some extent. Bifidobacterium infantis, Clostridium indolis, Enterococcus faecalis, Lactobacillus rhamnosus, and Ruminococcus obeum were able to reduce completely all four tested Sudan dyes and Para Red. Escherichia coli and Peptostreptococcus magnus were the only two strains that were not able to reduce any of the tested Sudan dyes and Para Red to any significant extent. Metabolites of the reduction of the tested Sudan dyes and Para Red by E. faecalis were isolated and identified by HPLC and LC/ESI-MS analyses and compared with authentic standards. Thus it appears that the ability to reduce Sudan dyes and Para Red except Sudan II is common among bacteria in the human colon. PMID:19580882

Xu, Haiyan; Heinze, Thomas M; Paine, Donald D; Cerniglia, Carl E; Chen, Huizhong

2010-04-01

190

A comparison of observed and modeled surface waves in southern Lake Michigan and the implications for models of sediment resuspension.  

SciTech Connect

Subsurface pressure sensors were used to make measurements of surface waves during 18 deployments in southern Lake Michigan between 1998 and 2000. Most of the observations were made during the unstratified period (November--May) in water depths between 10 and 55 m. The observations (as well as those obtained from the National Data Buoy Center (NDBC) buoy 45007, which is located in the middle of the southern basin of the lake) were compared to the results obtained from the Great Lakes Environmental Research Laboratory (GLERL)-Donelan wave model implemented on a 2-km grid. The results show that the wave model does a good job of calculating the wave heights, but consistently underestimates the wave periods. In over 80% of the cases the bottom stresses calculated from both the observations and the wave model results agree as to whether or not resuspension occurs, but over 70% of this agreement is for cases when resuspension does not occur; both stresses predict resuspension about 6% of the time. Since the bottom stresses calculated from the model results are usually lower than those calculated from the observations, resuspension estimates based on the wave model parameters are also lower than those calculated from the observed waves.

Hawley, N.; Lesht, B. M.; Schwab, D. J.; Environmental Research; Great Lakes Environmental Research Lab

2004-06-25

191

Late Pleistocene and Holocene uplift history of Cyprus: implications for active tectonics along the southern margin of the Anatolian microplate  

USGS Publications Warehouse

The nature of the southern margin of the Anatolian microplate during the Neogene is complex, controversial and fundamental in understanding active plate-margin tectonics and natural hazards in the Eastern Mediterranean region. Our investigation provides new insights into the Late Pleistocene uplift history of Cyprus and the Troodos Ophiolite. We provide isotopic (14C) and radiogenic (luminescence) dates of outcropping marine sediments in eastern Cyprus that identify periods of deposition during marine isotope stages (MIS) 3, 4, 5 and 6. Past sea-levels indicated by these deposits are c. 95±25 m higher in elevation than estimates of worldwide eustatic sea-level. An uplift rate of c. 1.8 mm/year and possibly as much as c. 4.1 mm/year in the past c. 26–40 ka is indicated. Holocene marine deposits also occur at elevations higher than those expected for past SL and suggest uplift rates of c. 1.2–2.1 mm/year. MIS-3 marine deposits that crop out in southern and western Cyprus indicate uniform island-wide uplift. We propose a model of tectonic wedging at a plate-bounding restraining bend as a mechanism for Late Pleistocene to Holocene uplift of Cyprus; uplift is accommodated by deformation and seismicity along the margins of the Troodos Ophiolite and re-activation of its low-angle, basal shear zone.

Harrison, R. W.; Tsiolakis, E.; Stone, B. D.; Lord, A.; Mcgeehin, J. P.; Mahan, S. A.; Chirico, P.

2013-01-01

192

Talc-bearing serpentinized peridotites from the southern Mariana forearc: implications for aseismic character within subduction zones  

NASA Astrophysics Data System (ADS)

The serpentinized peridotites overlying the subducted zones in the Izu-Bonin-Mariana (IBM) arc system have been interpret as the cause of the low-velocity layer identified beneath the IBM froearc, in turn few earthquakes occurred along the plate boundary. Chrysotile, which is a low temperature and highly hydrated phase of serpentine with low frictional strength, has been suggested as the low velocity material in the serpentinized peridotites, besides, brucite is inferred to be likely conducive to stable sliding. However, such idea encounters challenging in our serpentinized peridotites from the southern Mariana forearc, which absent both the above minerals. The presence of talc, which characterized by its weak, low-friction and inherently stable sliding behavior, provides new clue. Here we report the occurrence of talc in serpentinized peridotites collected from the landward trench slope of the southern Mariana forearc. We infer that talc is mainly forming as a result of the reaction of serpentine minerals with silica-saturated fluids released from the subducting slab, and talc also occurs as talc veins sometimes. Due to its unique physical properties, talc may therefore play a significant role in aseismic slip in the IBM subduction zone.

Wang, Xiaomei; Zeng, Zhigang; Liu, Changhua; Chen, Junbing; Yin, Xuebo; Wang, Xiaoyuan; Chen, Daigeng; Zhang, Guoliang; Chen, Shuai; Li, Kang; Ouyang, Hegen

2009-09-01

193

Logistics of Guinea worm disease eradication in South Sudan.  

PubMed

From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical-logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries. PMID:24445199

Jones, Alexander H; Becknell, Steven; Withers, P Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R; Stobbelaar, David; Makoy, Samuel Yibi

2014-03-01

194

Tylenchida associated with different crops in Sennar State (Sudan).  

PubMed

A study was done on the taxonomy and morphology of plant parasitic nematodes (Tylenchida) found in Sennar State (Sudan). Sixty samples of different crops were collected in the sugarcane area. Thirty samples originated from soil around the roots of Saccharum officinarum (sugarcane) from different ratoons and thirty samples were collected from other crops (Mangifera indica; Citrus limon; Citrus aurantifolia; Citrus paradisi; Citrus sinensis, Phoenix dactylifera, Musa sapentium; Cassia italica, Capsicum annuum, Sorghum bicolor, Sorghum sudanensis, Gossypium barbadense, Ficus nitida, Khaya senegalensis, Eucalyptus microtheca, Acacia nilotica, Acacia seyal, Azardichta indica, Cajanus cajana, Caltropsis spp. and Liguster ovalifolium). Seven species belonging to seven different genera of Tylenchida were identified: Paratrophurus lobatus, Scutellonema clathricaudatum, Hoplolaimus aegypti and Filenchus cylindricus. Helicotylenchus plumariae, Pratylenchus thornei and Malenchus andrassyi are new records for Sudan. These seven species were compared with the descriptions given in the literature and differences and variations were discussed. Additional morphological data were described by means of SEM microscopy. PMID:12425088

Elbadri, G A; Bert, W; Geraert, E

2001-01-01

195

Evidence for and implications of sedimentary diapirism and mud volcanism in the southern Utopia highland lowland boundary plain, Mars  

NASA Astrophysics Data System (ADS)

Several types of spatially associated landforms in the southern Utopia Planitia highland-lowland boundary (HLB) plain appear to have resulted from localized geologic activity, including (1) fractured rises, (2) elliptical mounds, (3) pitted cones with emanating lobate materials, and (4) isolated and coalesced cavi (depressions). Stratigraphic analysis indicates these features are Hesperian or younger and may be associated with resurfacing that preferentially destroyed smaller ( <8 km diameter) impact craters. Based on landform geomorphologies and spatial distributions, the documented features do not appear to be specifically related to igneous or periglacial processes or the back-wasting and erosion of the HLB scarp. We propose that these features are genetically related to and formed by sedimentary (mud) diapirs that ascended from zones of regionally confined, poorly consolidated, and mechanically weak material. We note morphologic similarities between the mounds and pitted cones of the southern Utopia boundary plain and terrestrial mud volcanoes in the Absheron Peninsula, Azerbaijan. These analogs provide a context for understanding the geological environments and processes that supported mud diapir-related modification of the HLB. In southern Utopia, mud diapirs near the Elysium volcanic edifice may have resulted in laccolith-like intrusions that produced the fractured rises, while in the central boundary plain mud diapirs could have extruded to form pitted cones, mounds, and lobate flows, perhaps related to compressional stresses that account for wrinkle ridges. The removal of material a few kilometers deep by diapiric processes may have resulted in subsidence and deformation of surface materials to form widespread cavi. Collectively, these inferences suggest that sedimentary diapirism and mud volcanism as well as related surface deformations could have been the dominant Hesperian mechanisms that altered the regional boundary plain. We discuss a model in which detritus would have accumulated thickly in the annular spaces between impact-generated structural rings of Utopia basin. We envision that these materials, and perhaps buried ejecta of Utopia basin, contained volatile-rich, low-density material that could provide the source material for the postulated sedimentary diapirs. Thick, water-rich, low-density sediments buried elsewhere along the HLB and within the lowland plains may account for similar landforms and resurfacing histories.

Skinner, James A.; Tanaka, Kenneth L.

2007-01-01

196

Focal mechanisms in the southern Aegean from temporary seismic networks - implications for the regional stress field and ongoing deformation processes  

NASA Astrophysics Data System (ADS)

The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 well-constrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini-Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW-SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE-SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east-west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW-SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except in volcanic areas, where both appear to be unrelated, and in the forearc where compressional principal stresses are very well aligned with compressional principal strain rates. This finding indicates that, except for volcanic areas, microseismic activity in the southern Aegean is not controlled by small-scale local stresses but rather reflects the regional stress field. The lateral and depth variations of the stress field reflect the various agents that influence tectonics in the Aegean: subduction of the Hellenic slab, incipient collision with continental African lithosphere, roll back of the slab in the southeast, segmentation of the slab, arc volcanism and extension of the Aegean crust.

Friederich, W.; Brüstle, A.; Küperkoch, L.; Meier, T.; Lamara, S.; Egelados Working Group

2014-05-01

197

Glacial geomorphology of the Torres del Paine region (southern Patagonia): Implications for glaciation, deglaciation and paleolake history  

NASA Astrophysics Data System (ADS)

The processes affecting paleoclimate variability and Pleistocene glacial landscape development in the southern mid-latitudes remain poorly understood, in part because of the scarcity of comprehensive, well-studied records. Glacial landforms are invaluable for reconstructing past ice-sheet, climate, and associated environmental changes along the southern Andes, but there are significant spatial and temporal gaps in existing data. In this paper, we present new geomorphic and sedimentologic analyses, including surficial maps, for the Torres del Paine region (51°S, 73°W), southern South America. Our findings provide a new framework for understanding changes in the regional glacier history and Pleistocene landscape development. Glacial extent during the local last glacial maximum (LGM) remains unknown but new chronological data supported by geomorphic evidence afford evidence for a larger ice sheet at Torres del Paine than previously assumed. Deglaciation from the local LGM was underway by 17,400 ± 200 (1?) cal. yr. BP. As opposed to previous suggestions, we have found that most of the moraines fringing the lakes in the Torres del Paine national park were deposited during a late-glacial expansion that occurred between 14,100 and 12,500 cal. yr. BP. Late-glacial advances also have been documented recently for the Última Esperanza and Lago Argentino basins to the south and north of Torres del Paine, respectively, suggesting an overall regional ice response to a climate signal. The Tehuelche paleolake accompanied each of the ice-sheet fluctuations in Torres del Paine. New data document at least three main phases of this paleolake, which drained eastward to the Atlantic Ocean, while the Andes gaps were blocked with ice. During the late phase of glacial lake formation, when water levels reached 125-155 m a.s.l., the lake likely merged with paleolake Consuelo in the Última Esperanza area at the end of the last glaciation. Lake Tehuelche in Torres del Paine had drained into the Pacific Ocean by the late-glacial period, suggesting that ice southwest of Torres del Paine may have retreated back into the mountains by this time.

García, Juan-Luis; Hall, Brenda L.; Kaplan, Michael R.; Vega, Rodrigo M.; Strelin, Jorge A.

2014-01-01

198

31 CFR 538.506 - 30-day delayed effective date for pre-November 4, 1997 trade contracts involving Sudan.  

Code of Federal Regulations, 2013 CFR

...effective date for pre-November 4, 1997 trade contracts involving Sudan. 538.506...effective date for pre-November 4, 1997 trade contracts involving Sudan. (a) Pre-existing trade contracts. Trade transactions...

2013-07-01

199

Seroepidemiological survey of chlamydial genital infections in Khartoum, Sudan.  

PubMed

A total of 494 patients (90 men and 404 women) attending a sexually transmitted diseases (STDs) clinic in Khartoum, Sudan, were studied to assess the prevalence of chlamydial genital infections. Antibodies to Chlamydia trachomatis serotypes D to K were found in four (4.4%) men and 42 (10.4%) women, and 10 (2.5%) women had antibodies to serotypes A to C. PMID:4018806

Omer, E E; Forsey, T; Darougar, S; Ali, M H; el-Naeem, H A

1985-08-01

200

Fossil Occurrence of Murine Rodent (Nesokia indica) in the Sudan.  

PubMed

A specimen of the murid rodent Nesokia indica has been recovered from a late Paleolithic archeological site in the Sudan. This is a range 1200 km south of the site of any known occurrences, and it indicates a different environment near the Nile River than that which exists at the present time. The late Paleolithic water table is inferred to have been more stable, allowing for permanent moist soil. PMID:17810306

Robinson, P

1966-10-14

201

The 2007 Rift Valley Fever Outbreak in Sudan  

PubMed Central

Rift Valley fever (RVF) is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus (RVFV) affecting humans and a wide range of animals. The virus is transmitted through bites from mosquitoes and exposure to viremic blood, body fluids, or tissues of infected animals. During 2007 a large RVF outbreak occurred in Sudan with a total of 747 confirmed human cases including 230 deaths (case fatality 30.8%); although it has been estimated 75,000 were infected. It was most severe in White Nile, El Gezira, and Sennar states near to the White Nile and the Blue Nile Rivers. Notably, RVF was not demonstrated in livestock until after the human cases appeared and unfortunately, there are no records or reports of the number of affected animals or deaths. Ideally, animals should serve as sentinels to prevent loss of human life, but the situation here was reversed. Animal contact seemed to be the most dominant risk factor followed by animal products and mosquito bites. The Sudan outbreak followed an unusually heavy rainfall in the country with severe flooding and previous studies on RVF in Sudan suggest that RVFV is endemic in parts of Sudan. An RVF outbreak results in human disease, but also large economic loss with an impact beyond the immediate influence on the directly affected agricultural producers. The outbreak emphasizes the need for collaboration between veterinary and health authorities, entomologists, environmental specialists, and biologists, as the best strategy towards the prevention and control of RVF.

Hassan, Osama Ahmed; Ahlm, Clas; Sang, Rosemary; Evander, Magnus

2011-01-01

202

New approaches for estimating global solar radiation across Sudan  

Microsoft Academic Search

This study investigates the possibility of establishing monthly-specific equations for estimating global solar radiation across Sudan. Using data from 16 stations, stretching along sub-humid, semi-arid, arid and hyper-arid zones, the derived equations embrace the dependence of global solar radiation on a single or a group of parameters, namely latitude, altitude and ratio of actual-to-maximum possible bright sunshine hours. Five kinds

Nadir Ahmed Elagib; Martin G Mansell

2000-01-01

203

Paleomagnetism and geochronology of late Paleozoic granitic rocks from the Lake District of southern Chile: Implications for accretionary tectonics  

SciTech Connect

K/Ar and {sup 40}Ar/{sup 39}Ar dating shows that granite rocks in the central Lake District, southern Chile, are late Paleozoic. Granitic rocks of similar age extend far up the coast of Chile, perhaps as much as 1800 km. The authors have obtained paleomagnetic directions from seven sites near Lago Ranco; these give a paleomagnetic pole at lat 57.4{degree}S, long 323.5{degree}E, with a circle of 95% confidence of 18.8{degree}. This is not significantly different from the mean late Paleozoic reference pole for the South American craton. If these results are characteristic of the late Paleozoic belt as a whole, it follows that post-late Plaeozoic accretion and terrane displacement are absent throughout much of the central Andes.

Beck, M.E. Jr; Alfredo, G.R.; Burmester, R.F. (Western Washington Univ., Bellingham (USA)); Francisco, M.H.; Francisco, H.A. (Universidad de Chile, Santiago (Chile)); Drake, R.E. (Berkeley Geochonology Center, Berkeley, CA (USA))

1991-04-01

204

Documenting drainage evolution in Bir Kiseiba, southern Egypt: Constraints from ground-penetrating radar and implications for Mars  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) helps to constrain the origin of relict and largely buried fluvial channels in the Bir Kiseiba region of southern Egypt. Our results indicate that the trunk channel to a tributary system identified in Shuttle Imaging Radar data is incised 10-12 m into bedrock, was southwest draining in its final configuration and laterally migrating toward the northwest, and accentuated relief along the nearby Kiseiba escarpment. Alluvium partially filling the main channel likely reflects effects of increasing aridity and bed load combined with less frequent, flashier precipitation. In contrast to defining channel margins, radar data do not indicate subtle stratigraphic changes in bedding related to fluvial aggradation, but do highlight local reflections likely corresponding to relict alluvial bedforms. Our results support the contention that an impulse GPR system, currently under development, could be deployed on a future Mars rover and assist in defining the regional evolution of the landscape and specific targets for sampling.

Grant, John A.; Maxwell, Ted A.; Johnston, Andrew K.; Kilani, Ali; Williams, Kevin K.

2004-09-01

205

Paleomagnetism of the Cambrian Sediments in Bornholm (Denmark) and Southern Sweden and Implications for Paleogeography of Baltica  

NASA Astrophysics Data System (ADS)

In Bornholm the Phanerozoic sedimentary succession overlying Precambrian basement starts with the Lower Cambrian (ca. 545 Ma) Nekso Sandstone Fm (NSF) that, in the earlier paleomagnetic analyses, have yielded characteristic magnetization (ChRM) similar to the Permian direction for Baltica. Here, we present paleomagnetic results from other Lower Cambrian formations in Bornholm (Balka Sandstone, Broens Odde siltstone) and in southern Sweden (Hardebega, Mickwitzia and Lingula Sandstones). Lithologically, most of these formations are very similar to the NSF and they are all considered stratigraphically younger. The intention was to check, whether a Permian paleomagnetic overprint occured on a regional scale and could it be attributed to secondary magnetic phases originating from fluids, which possibly traveled laterally along the contact between the basement and the Lower Cambrian sediments. In this report we show results of this regional test, followed by a comprehensive re-analysis of our Nekso data, including new results obtained after supplementary sampling and new petrologic information, which appeared recently. We have found that the NSF possessed a unique ChRM. The well-grouped and stable characteristic magnetization of the Nekso Sandstone contrasts with fairly chaotic, soft and badly preserved magnetization of the Balka, the Hardeberga, the Mickwitzia and the Lingulid sandstones of Bornholm and southern Sweden. A regional geological context, including the inferred diagenetic evolution of Lower Cambrian sediments, points to a syndepositional/early diagenetic origin of the characteristic remanence of the Nekso Sandstone, revealing a stable remanence applicable for plate tectonic interpretations. Similarity of the characteristic remanence of the NSF to the Permian direction for Baltica has been confirmed, but it is supposed to be casual, because of lack of any sign of a regional Permian remagnetization within the other Cambrian deposits of Southern Scandinavia. This is in line with recent results from isotopic and mineralogical studies which point to a final cementation and pore closure due to the late Silurian - early Devonian burial and diagenesis, what made the sedimentary rocks in question impermeable for mineralized fluids later during the Permian time. Supportive evidence for early Cambrian age of ChRM of the NSF is detrital/early diagenetic nature of hematite, which is the main carrier of the NSF magnetization. Taking into account the relatively low (up to 150circC) temperature of the burial event, a total thermoviscous resetting of the Ti-poor hematite carriers residing in the NSF seems unrealistic in any time of its geological history. The sub-horizontal paleomagnetic inclinations obtained for the NSF indicate an equatorial position of Bornholm (and hence of Baltica ) during the time of the remanence acquisition ( paleolatitude about 8circ N or S). Possible inclination and compaction errors may only be roughly estimated (say 10circ-15circ), and this would increase the paleolatitude for the early Cambrian position of the Bornholm basin up to 15circ. Following a minimum plate velocity principle and the shortest distance between paleopoles for the APWP we propose normal polarity and the southern hemisphere for Baltica. Such a paleogeographic position and orientation of Baltica increase the drift rate for this paleocontinent in the early Cambrian-Lower Ordovician time span and makes the APWP trend more complicated than envisaged by other authors.

Lewandowski, M.; Abrahamsen, N.

2001-12-01

206

Pattern of Maternal Knowledge and Its Implications for Diarrhoea Control in Southern Malawi: Multilevel Thresholds of Change Analysis  

PubMed Central

A survey was conducted in Southern Malawi to examine the pattern of mothers’ knowledge on diarrhoea. Diarrhoea morbidity in the district is estimated at 24.4%, statistically higher than the national average at 17%. Using hierarchically built data from a survey, a multilevel threshold of change analysis was used to determine predictors of knowledge about diarrhoeal aetiology, clinical features, and prevention. The results show a strong hierarchical structured pattern in overall maternal knowledge revealing differences between communities. Responsible mothers with primary or secondary school education were more likely to give more correct answers on diarrhoea knowledge than those without any formal education. Responsible mothers from communities without a health surveillance assistant were less likely to give more correct answers. The results show that differences in diarrhoeal knowledge do exist between communities and demonstrate that basic formal education is important in responsible mother’s understanding of diseases. The results also reveal the positive impact health surveillance assistants have in rural communities.

Masangwi, Salule Joseph; Grimason, Anthony Martin; Morse, Tracy Dawn; Kazembe, Lawrence; Ferguson, Neil; Jabu, George Christopher

2012-01-01

207

Increased dry-season length over southern Amazonia in recent decades and its implication for future climate projection  

PubMed Central

We have observed that the dry-season length (DSL) has increased over southern Amazonia since 1979, primarily owing to a delay of its ending dates (dry-season end, DSE), and is accompanied by a prolonged fire season. A poleward shift of the subtropical jet over South America and an increase of local convective inhibition energy in austral winter (June–August) seem to cause the delay of the DSE in austral spring (September–November). These changes cannot be simply linked to the variability of the tropical Pacific and Atlantic Oceans. Although they show some resemblance to the effects of anthropogenic forcings reported in the literature, we cannot attribute them to this cause because of inadequate representation of these processes in the global climate models that were presented in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report. These models significantly underestimate the variability of the DSE and DSL and their controlling processes. Such biases imply that the future change of the DSE and DSL may be underestimated by the climate projections provided by the Intergovernmental Panel on Climate Change’s Fifth Assessment Report models. Although it is not clear whether the observed increase of the DSL will continue in the future, were it to continue at half the rate of that observed, the long DSL and fire season that contributed to the 2005 drought would become the new norm by the late 21st century. The large uncertainty shown in this study highlights the need for a focused effort to better understand and simulate these changes over southern Amazonia.

Fu, Rong; Yin, Lei; Li, Wenhong; Arias, Paola A.; Dickinson, Robert E.; Huang, Lei; Chakraborty, Sudip; Fernandes, Katia; Liebmann, Brant; Fisher, Rosie; Myneni, Ranga B.

2013-01-01

208

Provenance analysis of upper Cretaceous strata in the Tethys Himalaya, southern Tibet: Implications for timing of India-Asia collision  

NASA Astrophysics Data System (ADS)

The provenance of upper Cretaceous strata in the Tethys Himalaya provides critical constraints on the closure time of the Neo-Tethys Ocean and the initial India-Asia collision. This paper reports detailed petrographic studies, in-situ detrital zircon U-Pb ages and Lu-Hf isotopic analyses, whole rock Nd-isotopes, and Cr-spinel electronic microprobe data from upper Cretaceous clastic sedimentary rocks of the Tethys Himalaya near Gyangze, southern Tibet. The Berriasian-Coniacian Jiabula Formation consists of black mudstone, chert and minor quartz arenite, and is dominated by detrital zircons with Archean-Cambrian U-Pb ages which were most likely derived from the Indian continent. Overlying conformably is the Santonian-Maastrichtian Chuangde Formation, which consists of red shale, limestone and chert. The Chuangde Formation is in turn overlain by the late Maastrichtian-late Paleocene Zongzhuo Formation, which is composed of black mudstone and lithic sandstone enclosing various olistoliths of sandstone, limestone and chert. The Rilang conglomerate is a lens which is located within the upper part of the Zongzhuo Formation and consists of an upward-thinning and fining succession of volcanic conglomerate, sandstone and black mudstone. The Zongzhuo Formation and the Rilang conglomerate record an abrupt influx of Cretaceous zircon grains with juvenile Hf isotopic compositions, arc-related Cr-spinels and positive ?Nd (0) sediments, suggesting an arc and suture-zone provenance. The change in provenance of upper Cretaceous strata from the southern Indian continent to a northern arc and suture zone is attributed to either (1) initial collision between the Indian plate and Lhasa terrane, or (2) initial collision between the Indian plate and an intra-oceanic arc. We prefer option (1) that the initiation of India-Asia collision occurred during Maastrichtian (~ 70-65 Ma).

Cai, Fulong; Ding, Lin; Yue, Yahui

2011-05-01

209

Alkenones and alkenes in surface waters and sediments of the Southern Ocean: Implications for paleotemperature estimation in polar regions  

NASA Astrophysics Data System (ADS)

The concentration of C37-C39 long-chain alkenones and alkenes were determined in surface water and surface sediment samples from the subpolar waters of the Southern Ocean. Distributions of these compounds were similar in both sample sets indicating little differential degradation between or within compound classes. The relative amounts of the tri- to tetra-unsaturated C 37 alkenones increased with increasing temperature for temperatures below 6°C similar to the di- and tri-unsaturated C 37 alkenones. The C 37 di-, tri-, and tetra-unsaturated methyl alkenones are used in paleotemperature calculations via the U37K and the U37K ratios. In these datasets, the relative abundances of the C 37:2 and the C 37.3 alkenones as a proportion of the total C 37 alkenones were opposite and strongly related to temperature (the latter with more scatter), but the abundance of the C37:4 alkenone showed no relationship with temperature. The original definition of U37K includes the abundance of 37:4 in both the numerator and denominator, and thus it is perhaps not surprising that there is considerable scatter in the values obtained for U37K at low temperatures. Of the two, we suggest that U37K' is the better parameter for use in paleotemperature estimations, even in cold locations. U37K' values in the sediments fall on virtually the same regression line obtained for the water column samples of Sikes and Volkman (1993), indicating that their calibration is suitable for use in Southern Ocean sediments. The comparison of water column data with sedimentary temperature estimates suggests that the alkenone distributions are dominated by contributions from the summer when the biomass of Emiliania huxleyi and presumably flux to the sediment, is expected to be high.

Sikes, Elisabeth L.; Volkman, John K.; Robertson, Lisette G.; Pichon, Jean-Jacques

1997-04-01

210

Nasopharyngeal Cancer in Sudan: Epidemiology, Clinical and Histological Characteristics  

PubMed Central

Objectives: To study the epidemiology, clinical features, staging, etiology and pathology of nasopharyngeal cancer in Sudan. Study design: This is a retrospective study. Setting: Ear, Nose and Throat Department Khartoum Teaching Hospital, Khartoum City, Sudan. Subjects and methods: Patients suspected to have nasopharyngeal cancer were assessed during the period March 2004 to May 2010. Data from confirmed cases was obtained; it included clinical and epidemiological information. Results: Three hundred and eighty five cases were studied. Bimodal age distribution of the disease was noted with two peaks, one at 15–19 years and one at 50–54 years. The male to female ratio was 2.6:1 and a distinct geographical distribution of the disease was noted, with clustering of cases in the towns of Dilling, Kadogli and the surrounding rural area of the Nuba Mountains. These areas in the Western States were reported to be of high background radiation due to naturally produced radioactive uranium. The Nuba tribe headed the list among other tribes, demonstrating a clear ethnic predilection. Sixty-eight cases presented at stage IV. There was a predominance of Type II (15.58%) and Type III (65.97%). Patients were treated by neoadjuvant chemoradiotherapy. Conclusions: NPC is an important form of cancer in Sudan. Some tribes are significantly more affected than others. Patients present with advanced disease. Environmental and genetic factors need further studies. Screening at risk populations that aim at early diagnosis and management of patients is recommended.

Abdullah, Nazik E.; Adam, Ameera A.M.; Khalifa, Eman H.; EL Hassan, Lamyaa A.M.; Ibrahim, M.E.; Hamad, K.M.; El Hassan, A.M.

2011-01-01

211

Malaria Risk Mapping for Control in the Republic of Sudan  

PubMed Central

Evidence shows that malaria risk maps are rarely tailored to address national control program ambitions. Here, we generate a malaria risk map adapted for malaria control in Sudan. Community Plasmodium falciparum parasite rate (PfPR) data from 2000 to 2010 were assembled and were standardized to 2–10 years of age (PfPR2–10). Space-time Bayesian geostatistical methods were used to generate a map of malaria risk for 2010. Surfaces of aridity, urbanization, irrigation schemes, and refugee camps were combined with the PfPR2–10 map to tailor the epidemiological stratification for appropriate intervention design. In 2010, a majority of the geographical area of the Sudan had risk of < 1% PfPR2–10. Areas of meso- and hyperendemic risk were located in the south. About 80% of Sudan's population in 2011 was in the areas in the desert, urban centers, or where risk was < 1% PfPR2–10. Aggregated data suggest reducing risks in some high transmission areas since the 1960s.

Noor, Abdisalan M.; ElMardi, Khalid A.; Abdelgader, Tarig M.; Patil, Anand P.; Amine, Ahmed A. A.; Bakhiet, Sahar; Mukhtar, Maowia M.; Snow, Robert W.

2012-01-01

212

New GPS Constraints on Crustal Deformation Along the Fairweather Fault and Implications for Motion of the Yakutat Block, Southern Alaska.  

NASA Astrophysics Data System (ADS)

Global Positioning System (GPS) measurements were made at several locations inboard and outboard of the Fairweather fault (FWF) to investigate motion along the fault and the motion of the southern portion of the Yakutat block (YB) with respect to the North American Plate (NAP). The triangular shaped YB is bounded by the FWF on the NE and on the SW by the so-called "Transition Zone" which intersects the FWF south of Cross Sound. The NW boundary of the YB is a complex zone of thrust faults north of the town of Yakutat where the YB is being actively accreted to the NAP. Our GPS measurement network stretches from the southern end of the YB to the town of Yakutat, a distance of 275 km. Our southernmost site lies on Chugach terrane, 14 km inboard of the offshore FWF and has a GPS derived velocity of 20.4 +/- 5.7 mm/yr toward N40o +/- 19o W relative to stable North America. Two sites near Dry Bay (100 km SE of Yakutat) lie on Yakutat terrane and move at speeds of 37.9 +/- 3.9 mm/yr and 34.4 +/- 9.1 mm/yr toward N 27o +/- 12o W and N 50o +/- 28o W, respectively. These latter sites lie 28 and 15 km outboard of the FW fault and have horizontal vectors similar in magnitude and direction to Yakutat (Fletcher and Freymueller, 1999 and this study): 43.6 +/- 2.4 mm/yr and N 39o +/- 5o W. The magnitudes of velocities at sites on the Yakutat block are approximately equal to the FWF-parallel component of Pacific-North America relative motion, and the counterclockwise-rotated directions suggest that the FWF-normal component of motion is accommodated offshore at least as far south as Dry Bay. The GPS velocities are used to help constrain the slip rate and locking depth of the FFW. Two sites 55 km northeast of Yakutat near the Fairweather fault, have vertical velocities of 37.5 +/- 2.7 mm/yr and 36.0 +/- 2.3 mm/yr, respectively, the highest currently measured rates of uplift in the world. The motion of all these sites run parallel or nearly parallel to the FWF, suggesting that most deformation fault-ward of these sites is right-lateral strike slip on the FFW or faults parallel to it.

Larsen, C. F.; Motyka, R. J.; Motyka, R. J.; Freymueller, J.; Echelmeyer, K.

2001-12-01

213

Volatile organic compounds from vegetation in southern Yunnan Province, China: Emission rates and some potential regional implications  

NASA Astrophysics Data System (ADS)

Little information is currently available regarding emissions of biogenic volatile organic compounds (BVOCs) in southern Asia. To address the need for BVOC emission estimates in regional atmospheric chemistry simulations, 95 common plant species were screened for emissions of BVOC in and near the Xishuangbanna Tropical Biological Gardens in southern Yunnan Province, Peoples' Republic of China in February 2003. In situ measurements with leaf cuvettes and branch bag enclosures were used in combination with portable gas chromatography, flame ionization, photoionization, and mass spectral detection to identify and quantify BVOC emissions. Forty-four of the species examined emitted isoprene at rates exceeding 20 ?g C g -1 (leaf dry weight) h -1. An emphasis was placed on the genus Ficus, which is important in the region and occupies a wide range of ecological niches. Several species in the footprint of a nearby flux tower were also examined. Several palm species and an abundant fern ( Cyclosorus parasiticus) emitted substantial amounts of isoprene, and probably accounted for observed daytime mean isoprene fluxes from the understory of a Hevea brasiliensis plantation of 1.0 and 0.15 mg C m -2 h -1 during the wet and dry seasons, respectively. These measurements verify that both the forest floor and canopy in this region can be sources of isoprene. Monoterpene emissions exceeded 1.0 ?g-C g -1 (leaf dry weight) h -1 from only 4 of 38 species surveyed, including some Ficus species and H. brasiliensis. However most of the trees of the latter species were sparsely foliated due to dry season senescence, and emission factors are approximately an order of magnitude lower than those reported during the wet season. BVOC emission rates and physiology of many species are impacted by reduced moisture availability, especially Mangifera indica. South Asia is a region undergoing rapid landuse change and forest plantation establishment, with large increases in area of high BVOC-emitting species in the genera Bambusa, Elaeis, Eucalyptus, Hevea, Pinus, and Populus (among others). This could result in profound changes in atmospheric chemistry in these regions, for instance, terpene emissions from H. brasiliensis could increase wet season biogenic organic aerosol burdens by approximately a factor of 2 in the Xishuangbanna region. Increases in plantation area established with high isoprene emitting species, (e.g. Bambusa spp. and Eucalyptus spp.) are also projected for China and other parts of Southeast Asia in the near future. Thus, landcover change in South Asian landscapes is usually associated with large increases in BVOC flux with the potential to alter the atmospheric chemical composition and air quality over this rapidly developing region.

Geron, Chris; Owen, Sue; Guenther, Alex; Greenberg, Jim; Rasmussen, Rei; Hui Bai, Jian; Li, Qing-Jun; Baker, Brad

214

Regional variations in the lead isotopic composition of galena from southern Korea with implications for the discrimination of lead provenance  

NASA Astrophysics Data System (ADS)

This study presents a comprehensive database (n = 215) of lead isotopes in galena from the southern Korean peninsula using new and published data. Of the 69 metal mines examined, predominantly skarn- and hydrothermal-type Pb-Zn-Au-Ag-Cu deposits were observed and were associated with Mesozoic magmatic activities. Galena samples from each geotectonic unit showed discrete lead isotopic signatures. The Gyeongsang basin samples were characteristically unradiogenic and had restricted variations in lead isotopic composition (206Pb/204Pb = 18.16-18.59, 207Pb/204Pb = 15.48-15.64, 208Pb/204Pb = 37.87-38.77). Their 208Pb/204Pb range indicated an involvement of source materials less thorogenic than the associated granites. The galena samples from Cambro-Ordovician carbonate rocks of the northeastern Yeongnam massif and eastern Taebaeksan basin had the most radiogenic 206Pb/204Pb (19.28 ± 0.14) and 207Pb/204Pb (15.833 ± 0.027) ratios. Their lead isotopic trend indicated a combined contribution of ore lead from granitic magmas, Precambrian basements, and overlain host rocks. Less radiogenic galena samples from the middle to southwestern parts of the Yeongnam massif and Okcheon belt showed limited lead isotopic variations (206Pb/204Pb = 18.332 ± 0.065, 207Pb/204Pb = 15.693 ± 0.012, 208Pb/204Pb = 38.93 ± 0.07 on average), probably resulted from mixing with a common crustal basement. The differences in lead isotopes between the radiogenic and unradiogenic groups from the Yeongnam massif and Okcheon belt may reflect the spatial dissimilarity of involved crustal rocks. The old crust appears to have significantly contributed ore lead to galenas from the western Gyeonggi massif, but the geochronological meaning of their steep 207Pb/204Pb-206Pb/204Pb trend is not clear. The comprehensive database constructed by the present study suggests that lead province in the southern Korean peninsula may be subdivided into four discrete zones. Linear discriminant analysis showed that more than 90% of the compiled data were correctly reclassified within their a priori zones. Such discrimination may be useful for a wide range of applications, including mineral exploration, archaeological correlation, and environmental characterization.

Jeong, Youn-Joong; Cheong, Chang-sik; Shin, Dongbok; Lee, Kwang-Sik; Jo, Hui Je; Gautam, Mukesh Kumar; Lee, Insung

2012-11-01

215

The Extent and Nature of Fluidity in Typologies of Female Sex Work in Southern India: Implications for HIV Prevention Programs  

PubMed Central

These authors examine the nature and extent of fluidity in defining the typology of female sex work based on the place of solicitation or place of sex or both places together, and whether sex workers belonging to a particular typology are at increased risk of HIV in southern India. Data are drawn from a cross-sectional survey conducted during 2007–2008 among mobile female sex workers (N = 5301) in four Indian states. Findings from this study address an important policy issue: Should programmatic prevention interventions be spread to cover all places of sex work or be focused on a few places that cover a large majority of sex workers? Results indicate that most female sex workers, including those who are usually hard to reach such as those who are mobile or who use homes for soliciting clients or sex, can be reached programmatically multiple times by concentrating on a smaller number of categories, such as street-, lodge-, and brothel-based sex workers.

Saggurti, Niranjan

2012-01-01

216

Magnetotelluric constraints on the fluid content in the upper mantle beneath the southern Canadian Cordillera: Implications for rheology  

NASA Astrophysics Data System (ADS)

Long-period magnetotelluric data were collected on two parallel profiles extending across the southern Canadian Cordillera and used to derive models of the electrical resistivity of the crust and mantle from the Cascadia subduction zone to the Alberta Basin. In the fore arc, the resistivity models indicate an east dipping conductor and conductive mantle wedge, caused by the release of aqueous fluids from the Juan de Fuca plate. Low resistivities are also found beneath the volcanic arc, associated with water released from the subducting slab and mantle melts. Low resistivities in the back-arc upper mantle at depths less than 60 km suggest a shallow asthenosphere compared to the adjacent North American craton where the lithosphere-asthenosphere boundary is at ~200 km. The resistivity of the back-arc upper mantle was interpreted using geotherms, laboratory studies of mineral properties and melting points to determine the type and quantity of fluids present. The low resistivities in the back-arc upper mantle require aqueous fluids, with water content increasing from 0.005 wt % at 50 km to 0.03 wt % at 150 km depth. In addition, melt fractions of up to 1.5% are required at depths less than ~135 km to explain the observed resistivities. The presence of these quantities of aqueous fluids and partial melt will lower the viscosity of the upper mantle, as required by geodynamic models that include vigorous convection in the back arc to explain the observed heat flow.

Rippe, Dennis; Unsworth, Martyn J.; Currie, Claire A.

2013-10-01

217

Paleoecological and Taphonomic Implications of Insect-Damaged Pleistocene Vertebrate Remains from Rancho La Brea, Southern California  

PubMed Central

The La Brea Tar Pits, the world’s richest and most important Late Pleistocene fossil locality, offers unsurpassed insights into southern California’s past environments. Recent studies at Rancho La Brea document that insects serve as sensitive and valuable paleoecological and taphonomic indicators. Of the thousands of fossil bird and mammal bones recovered from the Tar Pits, insect trace damage is thus far almost exclusively confined to the foot bones of large herbivores, especially bison, camel, and horse species. Our laboratory experiments with dermestid and tenebrionid beetles establish that the larvae of both consume bone, producing different characteristic feeding traces and providing the first documentation that tenebrionids consume bone. The presence of carcass-exploiting insects in the Rancho La Brea biota provides insight into the taphonomy of the asphaltic bone masses and the environmental conditions under which they accumulated. The succession of dermestids, tenebrionids, and indeterminate traces on many of the foot elements, combined with the climate restrictions and life cycles of these insects, indicate that carcasses could remain unsubmerged for at least 17–20 weeks, thus providing the most reliable estimate to date. Attribution of these traces also suggests that the asphaltic fossils only accumulated during warmer intervals of the Late Pleistocene. Forensic studies need to reevaluate the role of tenebrionids in carcass decomposition and other additional insects that modify bone.

Holden, Anna R.; Harris, John M.; Timm, Robert M.

2013-01-01

218

Stable isotopes in cave drip waters from the semi-arid southern Portugal: implication for paleoenvironment reconstructions  

NASA Astrophysics Data System (ADS)

Paleo-environmental studies rely on proxies for which present day conditions need to be documented. Here, we present results from a nearly two years sampling program of waters in precipitation, aquifers and cave drip waters in the semi arid region of Southern Portugal where a Mediterranean type climate prevails. Isotopic compositions of precipitations at Faro, from 1978 until 2001, are available through the Global Network of Isotopes in Precipitation (GNIP) database of the International Atomic Energy Agency. In addition, we measured oxygen and hydrogen isotopic compositions of water samples collected in 2011 and 2012 at one meteorological station located 20 km apart from the cave. In the cave itself, four different dripping locations were surveyed. Finally, five wells from the aquifer flowing underneath the cave were also sampled. Whereas local meteoric water line obtained from GNIP data shows an important contribution of local evaporating waters, precipitation data from this project rather points out to a drier moisture source, exhibiting a deuterium excess of close to 16.5 oȦquifer isotopic compositions show very small variations during the 2 yr sampling period, with mean values of -4.53±0.06 o (VSMOW) and 23.39±0.81 o (VSMOW) for ?18O and ?2H, respectively. On the other hand, drip waters isotopic compositions are dependent of the sampling site, although varying linearly (?2H~13.3*?18O + 38.1, R2=0.74, p

Veiga-Pires, Cristina; Hélie, Jean-François; Hillaire-Marcel, Claude

2014-05-01

219

Last glacial-interglacial environments in the southern Rocky Mountains, USA and implications for Younger Dryas-age human occupation  

NASA Astrophysics Data System (ADS)

The last glacial-interglacial transition (LGIT; 19-9 ka) was characterized by rapid climate changes and significant ecosystem reorganizations worldwide. In western Colorado, one of the coldest locations in the continental US today, mountain environments during the late-glacial period are poorly known. Yet, archaeological evidence from the Mountaineer site (2625 m elev.) indicates that Folsom-age Paleoindians were over-wintering in the Gunnison Basin during the Younger Dryas Chronozone (YDC; 12.9-11.7 ka). To determine the vegetation and fire history during the LGIT, and possible explanations for occupation during a period thought to be harsher than today, a 17-ka-old sediment core from Lily Pond (3208 m elev.) was analyzed for pollen and charcoal and compared with other high-resolution records from the southern Rocky Mountains. Widespread tundra and Picea parkland and low fire activity in the cold wet late-glacial period transitioned to open subalpine forest and increased fire activity in the Bølling -Allerød period as conditions became warmer and drier. During the YDC, greater winter snowpack than today and prolonged wet springs likely expanded subalpine forest to lower elevations than today, providing construction material and fuel for the early inhabitants. In the early to middle Holocene, arid conditions resulted in xerophytic vegetation and frequent fire.

Briles, Christy E.; Whitlock, Cathy; Meltzer, David J.

2012-01-01

220

Possible detachment zone in Precambrian rocks of Kanjamalai Hills, Cauvery Suture Zone, Southern India: Implications to accretionary tectonics  

NASA Astrophysics Data System (ADS)

Existence of a possible detachment zone at Elampillai region, NW margin of Kanjamalai Hills, located in the northern part of Cauvery Suture Zone (CSZ), Southern India, is reported here for the first time. Detailed structural mapping provides anatomy of the zone, which are rarely preserved in Precambrian high grade terranes. The detachment surface separates two distinct rock units of contrasting lithological and structural characters: the upper and lower units. The detachment zone is characterized by a variety of fold styles with the predominance of tight isoclinal folds with varied plunge directions, limb rotations and the hinge line variations often leading to lift-off fold like geometries and deformed sheath folds. Presence of parasitic folding and associated penetrative strains seem to be controlled by differences in mechanical stratigraphy, relative thicknesses of the competent and incompetent units, and the structural relief of the underlying basement. Our present study in conjunction with other available geological, geochemical and geochronological data from the region indicates that the structures of the detachment zone are genetically related to thrust tectonics forming a part of subduction-accretion-collision tectonic history of the Neoproterozoic Gondwana suture.

Mohanty, D. P.; Chetty, T. R. K.

2014-07-01

221

A 130 year record of pollution in the Suances estuary (southern Bay of Biscay): implications for environmental management.  

PubMed

Geochemical composition (Al, Zn, Pb, Cd, Cu, Ni, Cr and As) and foraminiferal assemblages in surface and core sediments were determined to assess the current situation and the recent environmental transformation of the Suances estuary (southern Bay of Biscay, Spain). Dating of the historical record has been achieved using isotopic analysis ((210)Pb, (137)Cs) and two benchmark events such as the beginning of the mineral exploitation in the Reocín Pb-Zn deposits and the evolution of the chlor-alkali industry (inputs of Hg). Concentrations of Zn, Pb and Cd in both surface and core samples are remarkably higher than background values, reflecting the existence of significant amounts of polluted materials. The dramatic environmental impact of this pollution is clearly recorded by the change of the foraminiferal assemblages that even reach an afaunal stage during recent decades. Application of two different sets of Sediment Quality Guidelines confirm that they exert potential risk to the environment, and therefore if dredged they should need specific management measures. The results provide a reference database to monitor future environmental changes in the Suances estuary, particularly as regards the contaminated sediment storage and the re-colonization by autochtonous meiofauna. PMID:18760425

Irabien, M J; Cearreta, A; Leorri, E; Gómez, J; Viguri, J

2008-10-01

222

Variability of fecal indicator bacteria in flowing and ponded waters in southern California: implications for bacterial TMDL development and implementation.  

PubMed

Recreational water quality is assessed by using water quality objectives for fecal indicator bacteria (FIB) including total coliform, fecal coliform (or E. coli), and/or Enterococcus. It is required under the Clean Water Act that a TMDL be developed for a bacteria-impaired water body. The development and implementation of bacterial TMDLs has proven challenging and often difficult due to unknown source(s) of FIB. This study found that FIB levels varied significantly in flowing water, ponded water, and associated sediment. FIB levels in isolated ponded water in waterways were significantly higher than in flowing water. Sediment under ponded water contained a great amount of FIB. Furthermore, FIB concentrations in ponded water tended to increase with increasing water temperature and to decrease with increasing water salinity. The result provides the field evidence of survival/growth of FIB in water and sediment under ambient conditions in southern California. A holistic approach including natural sources (e.g., a reference system) should be considered for practical and applicable purposes while developing and implementing bacterial TMDLs for pathogen-impaired waterbodies. PMID:17543369

He, Li-Ming; Lu, Jun; Shi, Weiyong

2007-07-01

223

Geophysical interpretation of the gneiss terrane of northern Washington and southern British Columbia, and its implications for uranium exploration  

USGS Publications Warehouse

The Omineca crystalline belt of northeastern Washington and southern British Columbia has a regional Bouguer gravity high, and individual gneiss domes within the terrane are marked by local gravity highs. Models of crustal structure that satisfy the limited available seismic-refraction data and explain the gravity high over the gneiss terrane permit the hypothesis that the core metamorphic complexes are the surface expression of a zone of dense infrastructure that makes up the upper 20 km (kilometers) of the crust within the crystalline belt. The Omineca crystalline belt is characterized regionally by low aeromagnetic relief. The gneiss domes and biotite- and biotite-muscovite granites are generally marked by low magnetic relief, whereas hornblende-biotite granites often cause magnetic highs. Exceptional magnetic highs mark zones of magnetic rock within the biotite- and biotite-muscovite granites and the gneiss domes; these areas are worthy of study, both to determine the origin and disposition of the magnetite and to explore the possible existence of uraniferous magnetite deposits.

Cady, John W.; Fox, Kenneth F.

1984-01-01

224

Formation of cycloidal dust devil tracks by redeposition of coarse sands in southern Peru: Implications for Mars  

NASA Astrophysics Data System (ADS)

Aeolian processes are the most active processes modifying the surface of Mars under present day climatic conditions. Besides wind streak changes and dune and ripple migrations, active dust devils occur frequently leaving numerous tracks on the Martian surface. These dust devil tracks (DDTs) are characterized by albedo changes with respect to their surroundings and are suggested to be caused by erosion of dust exposing coarser grained material. Here we show that DDTs with a cycloidal pattern analyzed in situ in southern Peru are formed by erosion of very coarse sands at the outer margins and its subsequent annular deposition in the central parts of dust devils. Field observations are supported by large-eddy simulations using typical dust devil parameters resembling the cycloidal morphology of the DDTs. Cycloidal DDTs observed on Mars resembling the Peruvian DDTs suggest an equivalent formation mechanism. Our results imply that the formation of DDTs on Mars are not solely due to dust erosion but also depositional processes and dust devils are strong enough to redistribute coarser grained material such as sands; hence they might contribute to the modification of the present day Martian landscape.

Reiss, Dennis; Zimmerman, Michael I.; Lewellen, David C.

2013-12-01

225

Jurassic-Cretaceous history of Cuba: implications for the evolution of the southern margin of the North American plate  

SciTech Connect

The oldest Cuban sedimentary rocks, clastics of the Bajocian San Cayetano Fm. provide the earliest record of North American-Gondwana rifting as seen in Cuba. A similar clastic sequence is seen below the carbonates of the Bahamas platform. In the Pinar del Rio area, the San Cayetano is succeeded by Oxfordian limestones, the shallow water Jagua Fm. to the south and deeper water Francisco Fm. to the north. Both contain basaltic pillow lavas, related either to rifting or to leaky transform motion parallel to the margin. The Oxfordian units are overlain by Kimmeridgian to Tithonian pelagic limestones, the Guasasa and Artemisa Fms. The later interfingers with northerly derived calci-turbidites. North of the Escambray, silici-clastic fragments in late Jurassic pelagic limestones suggests that a basement high existed south of the platform until the Berriasian. The carbonate platform continues to shed debris along its southern edge throughout the Cretaceous. To the south an Aptian-Albian episode of turbidite deposition suggests that South America-Africa rifting caused tectonic disturbances in the Caribbean. Southerly derived volcanoclastics deposited during the Maastrichtian marks the start of the Cuban orogeny.

Barros, J.A.; Rosencrantz, E.

1985-01-01

226

Deposits of the most recent eruption in the Southern Mono Craters, California: Description, interpretation and implications for regional marker tephras  

NASA Astrophysics Data System (ADS)

The penultimate eruption in the Mono Craters, Mono County, CA, USA, occurred in the southern section of the volcanic chain, and is herein named the South Mono eruption. The South Mono eruption occurred in 594–648cal A.D., and its products consist of widespread Plinian and phreatomagmatic fall, surge and pyroclastic flow deposits. The explosive deposits can be broken into Basal, Orange–Brown (surge dominated) and Upper subunits. The eruptive phase represented by the Upper beds was the most intense and voluminous, dispersing tephra over a wide region of eastern CA and western NV. South Coulee was the only effusive product of the eruption, and comprises the vast majority of the c. 0.4 cu km dense-rock equivalent (DRE) volume. The tephra overlies the deposits of Wilson Butte to the south, and is correlated herein with Wood's Tephra 2, and Walker Lake and Turupah Flats regional marker tephra layers. Other dates for these regional tephras may be the result of dating ash redeposited in debris flow events following fire.

Bursik, Marcus; Sieh, Kerry; Meltzner, Aron

2014-04-01

227

Biological Implications of Internal Waves and Internal Tidal Bores in the Southern Part of the California Current System  

NASA Astrophysics Data System (ADS)

Internal waves and internal tidal bores have been shown to cause rapid changes in temperature associated with vertical and horizontal displacements of water masses in many settings. Their role in the cross-shore transport of matter and energy implies that internal motions have important biological ramifications, particularly in biogeographic transition zones, such as the Southern California Current. Benthic invertebrates and macroalgae depend greatly on the nearshore pelagic environment for the transport of larvae and nutrients. We present 2 examples of how internal motions may modulate benthic populations in this transition zone by enhancing the transport of larvae or the provision of nutrients from offshore sites to the coast. At two sites along the Baja California peninsula, high-frequency variability in thermal structure and horizontal flows were observed. Physical observations show episodes (lasting about 1 h) of rapid variations (every 1 to 5 min) in horizontal flows and temperature in the nearshore water column. We show that the timing and intensity of larval settlement, as well as the residence of cold nutrient - rich water on the shelf, is related with internal motions just offshore. Variability in the direction from which these perturbations propagate may determine small-scale spatial patterns in demography of benthic populations. We discuss the importance of these events in modulating benthic invertebrate and macroalgal populations and how climate change in this transition zone may have important biological consequences via changes in thermocline depth and its subsequent impact on the occurrence of internal motions.

Ladah, L. B.; Leichter, J. J.; Tapia, F. J.

2007-05-01

228

Interaction of ambient conditions and fecal coliform bacteria in southern Lake Michigan beach waters: Monitoring program implications  

USGS Publications Warehouse

Excessive fecal coliform bacteria in public swimming waters can potentially threaten visitor health. Fecal coliform bacteria (1984-1989) and Escherichia coli (1990-1995) density were monitored weekly at the Indiana Dunes National Lakeshore beaches for 12 summers, and park officials closed swimming areas when fecal coliform density exceeded the state water quality criteria (400 CFU fecal coliforms/ 100 ml; 235 CFU E. coli/100 ml water). Due to a 24-hour incubation in the fecal coliform and E. coli assays, beaches were closed the day after collection of high fecal coliform. Our analysis suggests that it is not possible to predict one day's fecal coliform count based on the previous day's results in waters taken from southern Lake Michigan beaches. Dispersal and deposition of bacteria were not uniform among sites or across time apparently due to interactions among environmental variables including rainfall, wind direction, water temperature, and bacteria source. Rainfall combined with northwest winds increased bacteria concentrations. Escherichia coli followed a seasonal trend with similar fluctuations in density among beaches. We suggest that the current beach monitoring protocol is inadequate for predicting fecal coliform density at the time of beach closure, and, subsequently, its use for ensuring visitor safety remains questionable.

Whitman, Richard L.; Nevers, Meredith Becker; Gerovac, Paul J.

1999-01-01

229

77 FR 3369 - Presidential Determination on the Eligibility of South Sudan To Receive Defense Articles and...  

Federal Register 2010, 2011, 2012, 2013

...Determination on the Eligibility of South Sudan To Receive Defense Articles and Defense Services Under the Foreign Assistance Act of 1961...as amended, I hereby find that the furnishing of defense articles and defense services to the Republic of South Sudan will...

2012-01-24

230

Outbreaks of babesiosis in domestic livestock in the eastern region of the Sudan  

Microsoft Academic Search

The first incidence of babesiosis in cattle in the Sudan was recorded as far back as 1905. The provinces involved at that time included Kassala, Blue Nile, Darfur and Kordofan (Osman, 1976). Records of the Ministry of Animal Resources, Sudan Government (1902-1980) showed that the infection of livestock with Babesia is widespread in the country and the disease has been

A. A. Mohamed; I. A. Yagoub

1990-01-01

231

Overcoming Structural Adjustment Policies in Africa: Strategies for Vocational Education and Training in the Sudan.  

ERIC Educational Resources Information Center

Most developing countries have been debt ridden since the mid-1970s. This continuing debt burden has resulted in increasing prices and inflation, growing unemployment, and daily life difficulties. This problem has been acute for the Sudan. Sudan received help from the International Monetary Fund (IMF) in 1978 and negotiated new credit terms. By…

Washi, Sidiga; Pitamber, Sunita

232

Games, Social Simulations, and Data--Integration for Policy Decisions: The "Sudan" Game  

ERIC Educational Resources Information Center

In this article, the authors discuss the development of the "Sudan Game," an interactive model of the country in the time period leading up to the Sudanese referendum on the secession of the South. While many simulations are designed to educate about their subjects, the "Sudan Game" is intended to be a prototype for policy making via gameplay. It…

Landwehr, Peter; Spraragen, Marc; Ranganathan, Balki; Carley, Kathleen M.; Zyda, Michael

2013-01-01

233

South Sudan: institutional legacy of colonialism and the making of a new state  

Microsoft Academic Search

The paper argues that the post-colonial crisis of citizenship demands a rethinking of the paradigm of viewing colonialism simply as a system of economic exploitation to viewing colonialism as a political project that is anchored in law. The paper provides a historical and post-referendum analysis of the political division between North and South Sudan. As South Sudan seeks to build

Christopher Zambakari

2012-01-01

234

Raman Spectra of Sudan Red Dyes and the Fluorescence Background Removal  

Microsoft Academic Search

Sudan red dyes, as illegal food additives, can induce carcinoma of bladder. It is important to find out a method to provide an easy, precise and sensitive detection. The aim of our study is to obtain the Raman feature frequency excursion of SudanI, IIand III, and draw clear Raman spectra. We used the Raman Systems R-3000 spectrometer to detect the

Chen Chen; Peng Fei; Cheng Qinghua; Xu Dahai

2010-01-01

235

Dot immunogold filtration assay for rapid detection of Sudan I residue in chili powder  

Microsoft Academic Search

A method of Dot immunogold filtration assay for rapid detection of Sudan I residue in food was developed. Sudan I derivate-gelatin immunogen has been synthesized using the mixed anhydride method. Polyclonal antibodies were raised against the immunogen in rabbits. The purified antibody was immobilised on the nitrocellulose membrane as the test reagent. When the sample was added into the test

Liu Zhiguo; Fu Yunjie; Li Qi; Li Kui; Chen Jiangyuan; Zhou Guoping; Li Rui; Liu Lieju

2011-01-01

236

A monoclonal antibody-based immunosensor for detection of Sudan I using electrochemical impedance spectroscopy.  

PubMed

Sudan I monoclonal antibodies (Mabs) were prepared by hybridoma technique and firstly used to develop a Sudan I immunosensor by immobilizing the Mabs on a gold electrode. o-Mercaptobenzoic acid (MBA) was covalently conjugated on the gold electrode to form a self-assembled monolayer (SAM). The immobilization of Sudan I Mabs to the SAM was carried out through a stable acyl amino ester intermediate generated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydrosuccinimide (NHS), which could condense antibodies reproducibly and densely on the SAM. The changes of the electrode behavior after each assembly step were investigated by cyclic voltammetric (CV) technique. The Sudan I concentration was measured through the increase of impedance values in the corresponding specific binding of Sudan I and Sudan I antibody. A linear relationship between the increased electron-transfer resistance (Ret) and the logarithmic value of Sudan I concentrations was found in the range of 0.05-50 ng mL(-1) with the detection limit of 0.03 ng mL(-1). Using hot chili as a model sample, acceptable recovery of 96.5-107.3% was obtained. The results were validated by conventional HPLC method with good correlation. The proposed method was proven to be a feasible quantitative method for Sudan I analysis with the properties of stability, highly sensitivity and selectivity. PMID:21315921

Xiao, Fei; Zhang, Ningdan; Gu, Hongjie; Qian, Min; Bai, Jing; Zhang, Wen; Jin, Litong

2011-03-15

237

Review of SISA Student Dissertations on Library and Information Systems and Services in Eastern and Southern Africa.  

ERIC Educational Resources Information Center

Analyzes student dissertations at the School of Information Studies for Africa (SISA) at Addis Ababa University (Ethiopia) in order to present an overview of the library and information systems and services available in seven eastern and southern African countries: Ethiopia, Kenya, Malawi, Sudan, Tanzania, Uganda, and Zambia. (Author/LRW)

Chowdhury, G. G.; Tadesse, Taye T.

1995-01-01

238

Mafic high inertia crater floors in the southern highlands: Implications for a widespread post-impact modification process on Mars  

NASA Astrophysics Data System (ADS)

Understanding the history of impact crater modification and alteration can provide insights into planet scale processes that have occurred throughout Martian history. We have identified a unique class of Martian craters with flat, high thermal inertia floors, mafic mineralogies, and degraded morphologies. By using physical material properties in combination with morphologic and mineralogical data, it is possible to constrain the formation and modification history of these craters and better understand the crater modification processes, including post-impact volcanism, chemical weathering and hydrothermal alteration. This class of crater is prevalent throughout the southern highlands of Mars. The craters studied have degraded walls and rims, no central peak, no clearly visible ejecta deposits, an average diameter of ~52km (ranging in size from 18.5km to 179km), and occur almost exclusively in the southern highlands indicating an old formation age. The thermal inertia values derived from Thermal Emission Imaging System (THEMIS) measurements of crater floors are consistent with competent rocky material, while the walls and surrounding plains are composed of a less cohesive material. We have used THEMIS, Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), and Thermal Emission Spectrometer (TES) data to constrain the compositional variability of ~60 sites with the highest thermal inertia values. In general, the crater floors have higher abundances of mafic minerals (e.g. pyroxenes and olivine), while the surrounding plains have lower abundances of mafic minerals but show an increase in high-Si phase abundance. The composition, morphology, and distribution suggest that old, flat floored craters were resurfaced by a post-impact process that resulted in material significantly more mafic than the surrounding terrain. A possible formation mechanism may be related to inflationary volcanism associated with the impact [Schultz, 1976]. In this model, during the impact event, the crust is fractured providing a conduit for magma to erupt onto the surface and infill the original crater floor. The source of this magma is not well constrained and may be related to the unloading of the early Martian mantle and crust, resulting in partial melting of the underlying material. The mineralogy of these materials is consistent with a picritic basalt and indicates a primitive magma source, such as the Martian mantle. We have identified and characterized a unique class of Martian craters that has gone previously unstudied. If the distribution of this crater type is considered and the proposed model is correct, it is likely that inflationary volcanism is an important widespread process on Mars that has gone previously undocumented. This process could be responsible for extended periods of hydrothermal activity, a source of energy for altering materials, and may indicate high crustal heat flow early in Mars history. Schultz, P. H. (1976), Floor-fractured lunar craters, Earth, Moon, and Planets, 15(3).

Edwards, C. S.; Bandfield, J. L.; Rogers, D.; Christensen, P. R.

2010-12-01

239

Modified gulf of California model for South Georgia, north Scotia Ridge, and implications for the Rocas Verdes back-arc basin, southern Andes  

SciTech Connect

New field mapping and an integrated trace element and Nd isotopic study have been undertaken on the Jurassic-Cretaceous Larsen Harbour Complex on the island of South Georgia, recognized as a displaced part of the southern Andes ensialic, autochthonous Rocas Verdes marginal basin. Five basalt groups (Groups I-V) are identified from trace element data; initial Nd isotopic compositions suggest that they are derived from only two sources. Magmas produced during early stages of continental lithospheric attenuation (Groups I-III) were derived by varying degrees of partial melting and fractional crystallization from a large ion lithophile element (LILE)-enriched, low-{epsilon}{sub Nd} mantle source relative to normal (N)-type mid-ocean ridge basalt (MORB). Magmas produced during later stages of rifting (Groups IV and V) were, however, derived from a high-{epsilon}{sub Nd} asthenospheric mantle source similar to N-type MORB, unaffected by earlier LILE enrichment. Our data do not occur with previous suggestions that the Larsen Harbour Complex and, by implication, the Rocas Verdes formed in a supra-subduction-zone setting. On the basis of geologic and geochemical evidence, we favor basin formation along an oblique-slip margin akin to that of the Gulf of California.

Alabaster, T.; Storey, B.C. (Natural Environment Research Council, Cambridge (England))

1990-06-01

240

Compositional diversity of Late Cenozoic basalts in a transect across the southern Washington Cascades: Implications for subduction zone magmatism  

SciTech Connect

Major volcanoes of the Southern Washington Cascades (SWC) include the large quaternary stratovolcanoes of Mount St. Helens (MSH) and Mount Adams (MA) and the Indian Heaven (IH) and Simcoe Mountain (SIM) volcanic fields. There are significant differences among these volcanic centers in terms of their composition and evolutionary history. The authors conclude that subducted fluids and sediments do not play an essential role in producing these magmas. Rather, they infer that they formed by variable degree melting of a mixed mantle source consisting mainly of heterogeneously distributed OIB and mid-ocean ridge basalt source domains. Relatively minor occurrences of high field strength element (HFSE) depleted arclike basalts may reflect the presence of a small proportion of slab-metasomatized subarc mantle. The juxtaposition of such different mantle domains within the lithospheric mantle is viewed as a consequence of (1) tectonic mixing associated with accretion of oceanic and island arc terranes along the Pacific margin of North America prior to Neogene time, and possibly (2) a seaward jump in the locus of subduction at about 40 Ma. The Cascades arc is unusual in that the subducting oceanic plate is very young and hot. They suggest that slab dehydration outboard of the volcanic front resulted in a diminished role of aqueous fluids in generating or subsequently modifying SWC magmas compared to the situation at most convergent margins. Furthermore, with low fluid flux conditions, basalt generation is presumably triggered by other processes that increase the temperature of the mantle wedge (e.g., convective mantle flow, shear heating, etc.).

Leeman, W.P. (Rice Univ., Houston, TX (USA)); Smith, D.R. (Trinity Univ., San Antonio, TX (USA)); Hildreth, W. (Geological Survey, Menlo Park, CA (USA)); Palacz, Z.; Rogers, N. (Open Univ., Milton Keynes (England))

1990-11-10

241

A noble gas study of a granulite sample from the Nilgiri Hills, southern India: Implications for granulite formation  

NASA Astrophysics Data System (ADS)

The He and Ar isotopic composition of several mineral separates from a 2.5 Ga old enderbite sample from the Nilgiri Hills, southern India were analyzed. The sample contains abundant high-density carbonic fluid inclusions, which have been well characterized in previous studies on this particular sample. Garnet contains synmetamorphic primary fluid inclusions, while quartz and plagioclase contain re-equilibrated secondary inclusions. The noble gases were extracted by crushing or heating of the minerals. All measured He-3/He-4 ratios are above the typical value of old crustal rocks, which is about 0.01 - 0.02 times the atmospheric ratio (R(sub a)). Fluid inclusions from the crushed garnet sample contain helium with the highest He-3/He-4 ratio of 2.34 +/- 0.36 R(sub a). The He-3 excess is mantle derived and cannot be explained by a cosmogenic or nucleogenic He-3-rich component. The elemental and isotopic ratios of He, Ne and Ar in all minerals can be explained by a combination of elemental fractionation during diffusional loss of noble gases, production of radiogenic/nucleogenic He-4, Ne-21, Ne-22, and Ar-40, and atmospheric contamination. These data suggest that the enderbite sample represents a former mantle-derived tonalitic magma, which exsolved its volatiles upon crystallization in the lower crust. Liberation of a hugh amount of CO2 by similar intrusions, together with the heat provided by them, might be responsible for the dehydration of the former amphibolite facies rocks to the north bordering the Nilgiri Hills.

Dunai, T. J.; Touret, J. L. R.

1993-09-01

242

Climatic Implications of the Observed Temperature Dependence of the Liquid Water Path of Low Clouds in the Southern Great Plains  

NASA Technical Reports Server (NTRS)

Satellite observations of low-level clouds have challenged the assumption that adiabatic liquid water content combined with constant physical thickness will lead to a negative cloud optics feedback in a decadal climate change. We explore the reasons for the satellite results using four years of surface remote sensing data from the Atmospheric Radiation Measurement Program Cloud and Radiation Testbed site in the Southern Great Plains of the United States. We find that low cloud liquid water path is approximately invariant with temperature in winter but decreases strongly with temperature in summer, consistent with the satellite inferences at this latitude. This behavior occurs because liquid water content shows no detectable temperature dependence while cloud physical thickness decreases with warming. Thinning of clouds with warming is observed on seasonal, synoptic, and diurnal time scales; it is most obvious in the warm sectors of baroclinic waves. Although cloud top is observed to slightly descend with warming, the primary cause of thinning is the ascent of cloud base due to the reduction in surface relative humidity and the concomitant increase in the lifting condensation level of surface air. Low cloud liquid water path is not observed to be a continuous function of temperature. Rather, the behavior we observe is best explained as a transition in the frequency of occurrence of different boundary layer types: At cold temperatures, a mixture of stratified and convective boundary layers is observed, leading to a broad distribution of liquid water path values, while at warm temperatures, only convective boundary layers with small liquid water paths, some of them decoupled, are observed. Our results, combined with the earlier satellite inferences, imply that the commonly quoted 1.50 C lower limit for the equilibrium global climate sensitivity to a doubling of CO2, which is based on models with near-adiabatic liquid water behavior and constant physical thickness, should be revised upward.

DelGenio, Anthony D.; Wolf, Audrey B.

1999-01-01

243

Geochemical studies of hotspot volcanism in the Southern Pacific and its implications for mantle structure and dynamics  

SciTech Connect

This dissertation dedicates to geochemical investigations of hotspot volcanism in the Southern Pacific, by means of detailed, combined major, trace element and isotope studies of individual islands and island/seamount chains. Chapter 2 describes Sr, Nd and Pb isotopic studies of the whole Louisville Seamount Chain (LSC), to investigate long term evolution of hotspot source. Leaching experiments were conducted to study seawater alteration effects on both Sr and Nd isotopic compositions. Chapter 3 studies the Easter Island-Seamount Chain (EISC). Results from this study are most consistent with a hotspot origin for the EISC. Chapter 4 involves detailed geochemical studies of Tahiti, including Teahitia and Mehetia, from Society Islands. Both major and trace element compositions change systematically with time, indicating a progressive decrease in both the extent of partial melting and the amount of plume component. Isotope data are well correlated on the {sup 87}Sr/{sup 86}Sr vs. {sup 143}Nd/{sup 144}Nd diagram, suggesting mixing between two distinct end-members. Secular isotopic variation pattern records volcanic activities on Tahiti, which links geochemical characteristics to mantle processes of hotspot volcanism. A mantle blob model is preferred for island formation. Most existing OIB isotopic data can be explained by mixing of a small amount of sediments with MORB-like sources. These findings provide further geochemical evidence for a subducted slab origin of OIB sources. Chapter 5 synthesizes the author's own data and those from the literature, to evaluate mantle heterogeneities, origin and evolution of hotspot sources, and mantle structure and dynamics.

Cheng, Q.C.

1989-01-01

244

Implications for Gondwana of new Ordovician paleomagnetic data from igneous rocks in southern Victoria Land, East Antarctica  

NASA Astrophysics Data System (ADS)

New paleomagnetic data presented here from the southern Victoria Land (SVL) region of East Antarctica further refine the Gondwana early Paleozoic apparent polar wander path. The results are based on paleomagnetic analyses of Early to Middle Ordovician granitoids and dike swarms from which a new SVL pole (23°E, 3.5°S, A95 = 5.9°) was calculated. The new SVL paleomagnetic pole agrees with less well-determined Ordovician poles from other parts of East Antarctica indicating little or no translation/rotation across the East Antarctic craton since the Middle Ordovician. A new Gondwana ˜475 Ma mean pole (11°E 36°N, A95 = 7°, N = 4 studies, in African coordinates) has been calculated from African, Australian, and Antarctic Early and early Middle Ordovician paleomagnetic poles. Age reassignment of the Antarctic Sør Rondane paleopole (Zijderveld, 1968) places it into the Cambrian period and when combined with other Gondwana Cambrian poles results in a new Gondwana ˜515 Ma pole (7°E, 22°N, A95 = 9.5°, N = 7 studies, in African coordinates). The new Gondwana ˜515 Ma and ˜475 Ma poles, when compared with poles of similar age from Laurentia, allow paleogeographic reconstructions to be made that are in keeping with models predicting that Iapetus Ocean basin opening and closure may have been related first to rifting and then collision of Laurentia with Gondwana. The paleomagnetic data also suggest that most of West Gondwana moved toward lower latitudes between the Middle/Late Cambrian and the late Early Ordovician which may be reflected in the fossil record.

Grunow, Anne M.

1995-07-01

245

Climatic Implications of the Observed Temperature Dependence of the Liquid Water Path of Low Clouds in the Southern Great Plains  

NASA Technical Reports Server (NTRS)

Satellite observations of low-level clouds have challenged the assumption that adiabatic liquid water content combined with constant physical thickness will lead to a negative cloud optics feedback in a decadal climate change. We explore the reasons for the satellite results using four years of surface remote sensing data from the Atmospheric Radiation Measurement Program Cloud and Radiation Testbed site in the Southern Great Plains of the United States. We find that low cloud liquid water path is approximately invariant with temperature in winter but decreases strongly with temperature in summer, consistent with the satellite inferences at this latitude. This behavior occurs because liquid water content shows no detectable temperature dependence while cloud physical thickness decreases with warming. Thinning of clouds with warming is observed on seasonal, synoptic, and diurnal time scales; it is most obvious in the warm sectors of baroclinic waves. Although cloud top is observed to slightly descend with warming, the primary cause of thinning, is the ascent of cloud base due to the reduction in surface relative humidity and the concomitant increase in the lifting condensation level of surface air. Low cloud liquid water path is not observed to be a continuous function of temperature. Rather, the behavior we observe is best explained as a transition in the frequency of occurrence of different boundary layer types. At cold temperatures, a mixture of stratified and convective boundary layers is observed, leading to a broad distribution of liquid water path values, while at warm temperatures, only convective boundary layers with small liquid water paths, some of them decoupled, are observed. Our results, combined with the earlier satellite inferences, imply that the commonly quoted 1.5C lower limit for the equilibrium global climate sensitivity to a doubling of CO2 which is based on models with near-adiabatic liquid water behavior and constant physical thickness, should be revised upward.

DelGenio, Anthony

1999-01-01

246

Data assimilative hindcast on the Southern Flank of Georges Bank during May 1999: frontal circulation and implications  

NASA Astrophysics Data System (ADS)

The circulation of the tidal front along the Southern Flank of the Georges Bank region during May 1999 is examined for the purpose of understanding the transport of larval fish for periods of days to a week. Assimilation of shipboard ADCP data from several Georges Bank cruises into 3-D models is used to produce the hindcast circulation. Adjustments to boundary nodal elevations are estimated to minimize the misfit between model and observations both in frequency and time domains as described in Lynch and Hannah (J. Atmos. Oceanic Technol 18 (2001) 962) and Lynch and Naimie (Cont. Shelf Res. 22 (2002) 2191). An intercomparison of different methods of applying the adjustments is completed using drifter records and dye patch trajectories to provide a measure of skill. The computed flow fields show a skill of 2.4kmday-1 when compared to (unassimilated) drifter trajectories. The tracking of a dye-patch recovers an observed near-bottom cross-bank flow component that is not present without assimilation. Using these flow fields we then investigate the importance of the front as a retention mechanism using passive particle simulations. Wind, heat flux, and tides control the circulation across and along the tidal mixing front. Three 3-day time periods, before, during and after a wind event during May 1999 were studied. Model simulations suggest a highly variable cell-like circulation in the frontal region (onshore near the bottom, upwelling shoalward of the front, offshore at mid-depth and downwelling seaward of the front) that controls the exchange and retention of particles. During the periods when the cell-like circulation is active the highest accumulation of particles occurs in the areas surrounding the front.

Aretxabaleta, Alfredo; Manning, James; Werner, Francisco E.; Smith, Keston; Blanton, Brian O.; Lynch, Daniel R.

2005-05-01

247

New biostratigraphic results from the Kolbano area, southern West Timor: Implications for the Mesozoic—Tertiary stratigraphy of Timor  

NASA Astrophysics Data System (ADS)

In the Kolbano area of southern West Timor (eastern Indonesia), strongly deformed Mesozoic and Tertiary rocks of Australian continental margin affinity are exposed within the Banda arc-continent collision complex. New biostratigraphic age determinations are presented for a suite of rocks from this area which modify the ages and stratigraphic relationships of several formations within this sequence. These results have significance for the evolution of the Australian northwest passive margin, and for the timing of arc-continental collision. A new, more restricted definition of the Jurassic Oe Baat Formation is proposed, with the lower part of the section exposed in the Pasi Inlier reassigned to the Wai Luli Formation. The Oe Baat Formation is dated as entirely Upper Jurassic (upper Oxfordian-Tithonian), and previously reported Lower Cretaceous ages were not confirmed. In the "mid" Cretaceous-Palaeogene sequence, it has been established previously that formations are strongly diachronous. The new data suggest even stronger diachroneity than has been recognised previously. The Wai Bua/Nakfunu Formation ranges locally as young as Lower Eocene, the Borolalo Formation as young as Lower Oligocene, and the Ofu Formation to Lower Oligocene or younger. The Neogene "Batuputih Formation" of the Kolbano area is shown not to be equivalent to the Batu Putih Limestone in the Central Basin. A new name, Siu Formation, is provisionally proposed for the Kolbano sequence. The syn-orogenic Sonalete Formation is found to be at least as old as planktonic foraminiferal zone N19, suggesting that major orogenesis was already underway in the Kolbano area by late Early Pliocene.

Charlton, T. R.; Wall, D.

248

Peraluminous sapphirine-cordierite pods in Mg-rich orthopyroxene granulite from southern India: Implications for lower crustal processes  

NASA Astrophysics Data System (ADS)

Sapphirine-cordierite intergrowths occur as pods within garnet-absent, high-Mg orthopyroxene-granulite xenoliths in the Kambam valley, Madurai Block, southern India. Whereas the cores of the pods are composed of sapphirine (XMg = 0.871-0.897) - cordierite (XMg = 0.892-0.931) intergrowth along with rutile, zircon and monazite, the rims are characterized by cordierite, apatite, plagioclase, K-feldspar, quartz and minor calcite. The surrounding matrix comprises orthopyroxene (maximum Al2O3 4.1 wt.%, XMg 0.848-0.850), plagioclase, biotite and quartz, similar to the assemblage in the surrounding charnockites. Sapphirine in the Kambam rocks is characterized by high Al contents with an end-member composition in the range of 7:9:3 and 3:5:1. The occurrence of peraluminous sapphirine in association with cordierite and in the absence of phases such as sillimanite and garnet is distinct from ultrahigh-temperature assemblages in other localities within the Madurai Block. The peraluminous composition of the pods suggests that these domains could represent cryptic pathways through which aluminous melts migrated. The reaction of such peraluminous melts with Mg-rich orthopyroxene in the host granulite at temperatures of 1025 °C and pressures around 8 kbar as computed from phase equilibria modeling followed by an isobaric cooling is inferred to have generated the sapphirine-cordierite pods. The unusual high-Mg orthopyroxene granulite suggests interaction of supracrustal rocks with mafic magmas, which probably acted as the heat source for the partial melting of lower crust and UHT metamorphism.

Shazia, J. R.; Santosh, M.; Sajeev, K.

2012-09-01

249

Hillslope response to knickpoint migration in the Southern Appalachians: Implications for the evolution of post-orogenic landscapes  

USGS Publications Warehouse

The southern Appalachians represent a landscape characterized by locally high topographic relief, steep slopes, and frequent mass movement in the absence of significant tectonic forcing for at least the last 200 Ma. The fundamental processes responsible for landscape evolution in a post-orogenic landscape remain enigmatic. The non-glaciated Cullasaja River basin of south-western North Carolina, with uniform lithology, frequent debris flows, and the availability of high-resolution airborne lidar DEMs, is an ideal natural setting to study landscape evolution in a post-orogenic landscape through the lens of hillslope-channel coupling. This investigation is limited to channels with upslope contributing areas >2.7 km2, a conservative estimate of the transition from fluvial to debris-flow dominated channel processes. Values of normalized hypsometry, hypsometric integral, and mean slope vs elevation are used for 14 tributary basins and the Cullasaja basin as a whole to characterize landscape evolution following upstream knickpoint migration. Results highlight the existence of a transient spatial relationship between knickpoints present along the fluvial network of the Cullasaja basin and adjacent hillslopes. Metrics of topography (relief, slope gradient) and hillslope activity (landslide frequency) exhibit significant downstream increases below the current position of major knickpoints. The transient effect of knickpoint-driven channel incision on basin hillslopes is captured by measuring the relief, mean slope steepness, and mass movement frequency of tributary basins and comparing these results with the distance from major knickpoints along the Cullasaja River. A conceptual model of area-elevation and slope distributions is presented that may be representative of post-orogenic landscape evolution in analogous geologic settings. Importantly, the model explains how knickpoint migration and channel- hillslope coupling is an important factor in tectonically-inactive (i.e. post-orogenic) orogens for the maintenance of significant relief, steep slopes, and weathering-limited hillslopes. ?? 2011 John Wiley & Sons, Ltd.

Wegmann, S. F. G.; Franke, K. L.; Hughes, S.; Lewis, R. Q.; Lyons, N.; Paris, P.; Ross, K.; Bauer, J. B.; Witt, A. C.

2011-01-01

250

Controls on large landslide distribution and implications for the geomorphic evolution of the southern interior Columbia River basin  

USGS Publications Warehouse

Large landslides (>0.1 km2) are important agents of geomorphic change. While most common in rugged mountain ranges, large landslides can also be widespread in relatively low-relief (several 100 m) terrain, where their distribution has been relatively little studied. A fuller understanding of the role of large landslides in landscape evolution requires addressing this gap, since the distribution of large landslides may affect broad regions through interactions with channel processes, and since the dominant controls on landslide distribution might be expected to vary with tectonic setting. We documented >400 landslides between 0.1 and ~40 km2 across ~140,000 km2 of eastern Oregon, in the semiarid, southern interior Columbia River basin. The mapped landslides cluster in a NW-SE-trending band that is 50-100 km wide. Landslides predominantly occur where even modest local relief (~100 m) exists near key contacts between weak sedimentary or volcaniclastic rock and coherent cap rock. Fault density exerts no control on landslide distribution, while ~10% of mapped landslides cluster within 3-10 km of mapped fold axes. Landslide occurrence is curtailed to the NE by thick packages of coherent basalt and to the SW by limited local relief. Our results suggest that future mass movements will localize in areas stratigraphically preconditioned for landsliding by a geologic history of fluviolacustrine and volcaniclastic sedimentation and episodic capping by coherent lava flows. In such areas, episodic landsliding may persist for hundreds of thousands of years or more, producing valley wall slopes of ~7??-13?? and impacting local channels with an evolving array of mass movement styles. ?? 2011 Geological Society of America.

Safran, E. B.; Anderson, S. W.; Mills-Novoa, M.; House, P. K.; Ely, L.

2011-01-01

251

Radiocarbon dating and paleoclimatic significance of subfossil Limicolaria in northwestern Sudan  

NASA Astrophysics Data System (ADS)

The discovery, identification, and radiocarbon dating of the large achatinid land snail Limicolaria kambeul chudeaui at six places in northwestern Sudan, north of the 100-mm isohyet, provide convincing evidence that at least 300 mm annual rainfall existed there 6000 yr ago. Since then the rainfall north of ca. 20°N lat in the eastern Sahara has certainly been <300 mm and probably <200 mm. Accelerator mass spectrometry has allowed the organic fraction, presumably conchiolin, to be accurately radiocarbon dated whereas carbonate fractions are ca. 600 yr too old. Comparative studies show the subfossil form, L. k. chudeaui, to be the most primitive in its species complex and to occupy a narrow east-west belt across Africa north of 15°N and west of 35°E. The northern limit of living forms lies within the southern part of the Sahelian zone in forest or forest-savanna. They cannot live in open grassland. Therefore, the distribution of L. k. chudeaui marks the former northern position of this zone during the middle Holocene, indicating a latitudinal shift of at least 5° (500 km).

Haynes, C. Vance; Mead, Albert R.

1987-07-01

252

Occurrence of tetrodotoxin and paralytic shellfish poisons in a gastropod implicated in food poisoning in southern Taiwan.  

PubMed

The toxicity of the gastropod Nassarius papillosus implicated in a food paralytic poisoning incident in Liuchiu Island, Taiwan, in October 2005 is reported. The symptoms of a victim (67 years old) were featured by general paresthesia, paralysis of phalanges and extremities, paralysis, coma, and aphasia. The remaining specimens of shell were assayed for toxicity. The range of specimen toxicity was found to be 63-474 mouse units (MU) per specimen for N. papillosus by a tetrodotoxin (TTX) bioassay. The mean (SD) toxicity of the digestive gland and other portions were 296 +/- 120 and 382 +/- 156 MU in N. papillosus. The toxin was partially purified from the acidic methanol extract of the gastropod by using a C18 solid-phase extraction column. The eluate was then filtered through a 3000 MW cut-off ultrafree microcentrifuge filter. It was shown that the toxin purified from gastropods analysed by high-performance liquid chromatography and liquid chromatography/mass spectrometry contained TTX 42-60 microg g(-1) (about 90%), whereas along with minor paralytic shellfish poisons (PSP) it was 3-6 microg g(-1) (about 10%). PMID:17613078

Jen, H-C; Lin, S-J; Lin, S-Y; Huang, Y-W; Liao, I-C; Arakawa, O; Hwang, D-F

2007-08-01

253

Nd-Sr isotopic and geochemical characteristics of the southern Adamello (northern Italy) intrusives: Implications for crustal versus mantle origin  

NASA Astrophysics Data System (ADS)

Among the Periadriatic Tertiary calc-alkaline intrusions in northern Italy, the Adamello batholith displays the most convincing evidence for a mafic parentage. This is particularly the case for the southern Adamello, where minor ultramafic to gabbroic bodies form the margins of several distinct and dominantly tonalitic plutons. Isotopic analyses are presented for the Val Fredda and Blumone ultramafic-gabbroic to tonalitic-leucoquartzdioritic suites, for the more felsic rock types of the spatially predominant Re di Castello group, as well as for a lamprophyre. This dike of picrobasaltic composition is thought to represent the parental magma. Field relations and a large body of petrographic, geochemical and mineral chemical data point to a cogenetic origin for all of these rocks and to magmatic differentiation with fractional crystallization and accumulation as the main evolutionary mechanism. This is compatible with the isotopic results for the Blumone series and the mafic rocks of Val Fredda with ?Nd = +3.8 to +1.5 and ?Sr = -9.1 to -4.6. A common parental magma similar to the lamprophyre (?Nd = +3.1, ?Sr = -4.4) also seems plausible. The isotopically homogeneous felsic lithologies of Val Fredda (?Nd = +0.1 to -0.3, ?Sr = +2.9 to +0.7), structurally intimately associated with their mafic counterpart, indicate crustal contamination incurred prior to their differentiation. For the Re di Castello group, progressing crustal affinity of isotopic compositions (?Nd of -1.9 to -4.9 and ?Sr of +16.5 to +40.9) with chemical differentiation implies large-scale interaction with a granitoid crustal component. Attempts at quantifying this process reveal individual characteristics and evolution for each pluton. The data indicate extraction of this component from a source in the lower crust with time-integrated low Rb/Sr, ?Sr approximating +50 and ?N close to -6 corresponding to a 1000 Ma crustal residence age. If a two-stage evolution is assumed, formation of a gabbroic reservoir from the above parental melt would require uptake of some 4-12 wt % of granitoid component by combined assimilation/fractional crystallization, whereas subsequent evolution to tonalitic compositions would necessitate admixing of 40-70 wt % of granitoid partial melt. Assimilation thus mainly occurs during evolution from gabbroic to tonalitic compositions, when the mafic magma is ponded near the mantle-crust boundary and where homogenization prior to resuming buoyant ascent is assured. Precise locations and more detailed petrography of the samples is available with entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, DC 20009. Document 91B-002; $2.50. Payment must accompany order.

Kagami, Hiroo; Ulmer, Peter; Hansmann, Werner; Dietrich, Volker; Steiger, Rudolf H.

1991-08-01

254

Geophysical exploration of an active pockmark field in the Bay of Concarneau, southern Brittany, and implications for resident suspension feeders  

NASA Astrophysics Data System (ADS)

About a decade ago, a large field of pockmarks (individual features up to 30 m in diameter and <2 m deep) was discovered in water depths of 15-40 m in the Bay of Concarneau in southern Brittany along the French Atlantic coast, covering an overall area of 36 km2 and characterised by unusually high pockmark densities in places reaching 2,500 per square kilometre. As revealed by geophysical swath and subbottom profile data ground-truthed by sediment cores collected during two campaigns in 2005 and 2009, the confines of the pockmark field show a spectacular spatial association with those of a vast expanse of tube mats formed by a benthic community of the suspension-feeding amphipod Haploops nirae. The present study complements those findings with subbottom chirp profiles, seabed sonar imagery and ultrasonic backscatter data from the water column acquired in April 2011. Results show that pockmark distribution is influenced by the thickness of Holocene deposits covering an Oligocene palaeo-valley system. Two groups of pockmarks were identified: (1) a group of large (>10 m diameter), more widely scattered pockmarks deeply rooted (up to 8 ms two-way travel time, TWTT) in the Holocene palaeo-valley infills, and (2) a group of smaller, more densely spaced pockmarks shallowly rooted (up to 2 ms TWTT) in interfluve deposits. Pockmark pore water analyses revealed high methane concentrations peaking at ca. 400 ?l/l at 22 and 30 cm core depth in silty sediments immediately above Haploops-bearing layers. Water column data indicate acoustic plumes above pockmarks, implying ongoing pockmark activity. Pockmark gas and/or fluid expulsion resulting in increased turbidity (resuspension of, amongst others, freshly settled phytoplankton) could at least partly account for the strong spatial association with the phytoplankton-feeding H. nirae in the Bay of Concarneau, exacerbating impacts of anthropogenically induced eutrophication and growing offshore trawling activities. Tidally driven hydraulic pumping in gas-charged pockmarks represents a good candidate as large-scale short-term triggering mechanism of pockmark activation, in addition to episodic regional seismic activity.

Baltzer, Agnès; Ehrhold, Axel; Rigolet, Carinne; Souron, Aurélie; Cordier, Céline; Clouet, Hélène; Dubois, Stanislas F.

2014-04-01

255

Geophysical exploration of an active pockmark field in the Bay of Concarneau, southern Brittany, and implications for resident suspension feeders  

NASA Astrophysics Data System (ADS)

About a decade ago, a large field of pockmarks (individual features up to 30 m in diameter and <2 m deep) was discovered in water depths of 15-40 m in the Bay of Concarneau in southern Brittany along the French Atlantic coast, covering an overall area of 36 km2 and characterised by unusually high pockmark densities in places reaching 2,500 per square kilometre. As revealed by geophysical swath and subbottom profile data ground-truthed by sediment cores collected during two campaigns in 2005 and 2009, the confines of the pockmark field show a spectacular spatial association with those of a vast expanse of tube mats formed by a benthic community of the suspension-feeding amphipod Haploops nirae. The present study complements those findings with subbottom chirp profiles, seabed sonar imagery and ultrasonic backscatter data from the water column acquired in April 2011. Results show that pockmark distribution is influenced by the thickness of Holocene deposits covering an Oligocene palaeo-valley system. Two groups of pockmarks were identified: (1) a group of large (>10 m diameter), more widely scattered pockmarks deeply rooted (up to 8 ms two-way travel time, TWTT) in the Holocene palaeo-valley infills, and (2) a group of smaller, more densely spaced pockmarks shallowly rooted (up to 2 ms TWTT) in interfluve deposits. Pockmark pore water analyses revealed high methane concentrations peaking at ca. 400 ?l/l at 22 and 30 cm core depth in silty sediments immediately above Haploops-bearing layers. Water column data indicate acoustic plumes above pockmarks, implying ongoing pockmark activity. Pockmark gas and/or fluid expulsion resulting in increased turbidity (resuspension of, amongst others, freshly settled phytoplankton) could at least partly account for the strong spatial association with the phytoplankton-feeding H. nirae in the Bay of Concarneau, exacerbating impacts of anthropogenically induced eutrophication and growing offshore trawling activities. Tidally driven hydraulic pumping in gas-charged pockmarks represents a good candidate as large-scale short-term triggering mechanism of pockmark activation, in addition to episodic regional seismic activity.

Baltzer, Agnès; Ehrhold, Axel; Rigolet, Carinne; Souron, Aurélie; Cordier, Céline; Clouet, Hélène; Dubois, Stanislas F.

2014-06-01

256

Foot and mouth disease in the Borana pastoral system, southern Ethiopia and implications for livelihoods and international trade.  

PubMed

Participatory epidemiology (PE) was used on the Borana plateau of southern Ethiopia to understand pastoralist's perceptions of the clinical and epidemiological features of foot and mouth disease (FMD) in cattle. Matrix scoring showed good agreement between informant groups on the clinical signs of acute and chronic FMD, and findings were cross-checked by clinical examination of cattle and assessment of previous clinical FMD at herd level by detection of antibody to non structural proteins of FMD virus. The positive predictive value of pastoralist's diagnosis of FMD at herd level was 93.1%. The annual age-specific incidence and mortality of acute FMD in 50 herds was estimated using proportional piling. The estimated mean incidence of acute FMD varied from in 18.5% in cattle less than two years of age to 14.0% in cattle three to four years of age. The estimated mean mortality due to acute FMD varied from 2.8% in cattle less than two years of age to 0.3% in cattle three of age or older. Pearson correlation coefficients for acute FMD by age group were -0.12 (p>0.05) for incidence and -0.59 (p<0.001) for mortality. Estimates of the annual incidence of chronic FMD varied from 0.2% in cattle less than two years of age to 1.8% in cattle three to four years of age. The Pearson correlation coefficient for the incidence of chronic FMD by age group was 0.47 (p<0.001). Outbreaks of FMD peaked in Borana cattle during the two dry seasons and were attributed to increased cattle movement to dry season grazing areas. The mean seroprevalence of FMD was estimated at 21% (n=920) and 55.2% of herds (n=116) tested seropositive. Serotyping of 120 seropositive samples indicated serotypes O (99.2%), A (95.8%), SAT 2 (80%) and C (67.5%). The endemic nature of FMD in Borana pastoral herds is discussed in terms of the direct household-level impact of the disease, and the increasing export of cattle and chilled beef from Ethiopia. PMID:18551776

Rufael, T; Catley, A; Bogale, A; Sahle, M; Shiferaw, Y

2008-01-01

257

Source process and tectonic implications of the 8 January 2006 ( Mw 6.7) Kythira earthquake, southern Greece  

NASA Astrophysics Data System (ADS)

On 8 January 2006 at 11:34 (GMT) a strong ( Mw 6.7) subcrustal earthquake occurred near Kythira island in southern Greece, causing damage to the surrounding area while the shock was also felt in most of the eastern Mediterranean. The event and its aftershocks were recorded by a regional network of 31 stations equipped with three-component broad-band seismometers that cover most parts of the Greek region. Initial locations of the earthquake sequence showed a diffuse pattern, therefore catalog and cross-correlation differential travel times were input to a shrinking grid-search relocation algorithm in order to obtain accurate relative locations. After this relocation most aftershocks form a tight cluster around the mainshock at depths between 44 and 53 km. Subsequently, waveforms from 12 stations giving the best possible azimuthal coverage around the Kythira event were inverted in order to investigate its source process. A parallel, non-negative least-squares inversion technique utilizing multiple time windows was used to derive the spatiotemporal slip distribution. The fault surface was parameterized by subfaults of 3 km × 3 km size covering a length and down-dip width of 91 and 100 km, respectively. Inversion results indicate that the fault plane is probably the one dipping towards SE. The slip distribution model showed that there are two areas of large slip (˜60 cm), the largest extending between 38 and 80 km depth and a smaller one at depths 65-82 km. The moment rate function consists of a large initial peak with a duration of about 11 s followed by a number of smaller peaks, probably due to coseismic slip on some of the subfaults. Furthermore, the hypocenters of the relocated aftershocks coincide with the areas of minimum slip (<10 cm) while the hypocenter of the mainshock is located near the edge of the larger slip patch. Sensitivity and resolution tests confirmed the adequacy of the inversion parameters used and the stability of the solution. The Kythira earthquake was probably caused by the contortion of the downgoing African slab that results in the development of along-strike compression forces in the Kythira strait.

Konstantinou, K. I.; Lee, S.-J.; Evangelidis, C. P.; Melis, N. S.

2009-07-01

258

3-D Mohr circle construction using vein orientation data from Gadag (southern India) - Implications to recognize fluid pressure fluctuation  

NASA Astrophysics Data System (ADS)

In this paper orientations of quartz veins from the Archaean age lode-gold bearing region of Gadag (southern India) are used to determine the relative stress and fluid pressure (Pf) conditions by constructing 3-D Mohr circle. Anisotropy of magnetic susceptibility (AMS) analysis of the host massive metabasalt reveals that the magnetic foliation is NW-SE striking, which is related to early NE-SW compression (D1/D2 deformation) that affected the region. The quartz veins have a wide range of orientations, with NW-SE striking veins (steep northeasterly dips) being the most prominent. Vein emplacement is inferred to have taken place under NW-SE compression that is known to have caused late deformation (D3) in the region. It is argued that the NW-SE fabric defined the pre-existing anisotropy and channelized fluid flow during D3. The permeability was initially low, which resulted in high Pf (>?2). 3-D Mohr circle analysis indicates that the driving pressure ratio (R?) was 0.94, a condition that favoured fracturing and reactivation of fabric elements (foliations and fractures) having a wide range of orientations. This led to an increase in permeability and fluid flowed (burped) into the fractures. Resulting vein emplacement and sealing of fractures led to a reduction of Pf (?2). Thus, it is concluded that the quartz veins in the Gadag region are a consequence of an interplay between conditions that fluctuated from Pf > ?2 to Pf < ?2.

Mondal, Tridib Kumar; Mamtani, Manish A.

2013-11-01

259

Using Ground Penetrating Radar to Constrain the Drainage Evolution in Southern Egypt and Implications for Future Deployment on Mars  

NASA Astrophysics Data System (ADS)

Ground penetrating radar (GPR) constrains the origin of relict and largely buried fluvial channels in the Bir Kiseiba region of southern Egypt. GPR results indicate that the trunk channel to a tributary system identified in Shuttle Imaging Radar (SIR) data is incised 10 to 12 meters into bedrock, was southwest-draining and laterally migrating toward the northwest, and accentuated relief along the nearby Kiseiba escarpment. Alluvium partially filling the main channel likely reflects effects of increasing aridity and bed load combined with less frequent, flashier precipitation. In contrast to defining channel margins, GPR data do not indicate subtle stratigraphic changes in bedding related to fluvial aggradation, but do highlight local reflections likely corresponding to relict alluvial bar forms. These GPR data complement the SIR and field data and permit a better understanding of the evolution of this enigmatic landscape. The Egyptian study area occurs in a region long considered to possess potential analogs for landforms on Mars. GPR results from Egypt and other analog terrain combined with consideration of factors influencing radar performance on Mars instill confidence that a rover-deployed GPR can achieve 10 to 20 m penetration and provide critical constraint on geologic setting and context for other rover instruments. To take advantage of this potential, a rover-deployable impulse GPR is under development for future Mars missions and possesses mass, volume, and power limits of 0.5 kg, 3400 cc, 3 W (peak), respectively. The GPR has no moving parts, includes a body conformal antenna capable of configuration at 150 MHz to more than 600 MHz, will collect 0.3 MB data per day (assuming a 50 meter traverse), and is being successfully tested in Mars analog environments. By analogy to the results from Egypt, a Mars GPR deployed in the vicinity of valley networks should be able to distinguish diagnostic signatures required for identifying the sources of water responsible for shaping the ancient Martian landscape. In addition, a Mars impulse GPR could assist in defining geologic setting and guide sample collection for in situ analyses or return to the Earth. GPR could also assist in detecting and avoiding rover hazards such dust-filled cracks or voids.

Grant, J. A.; Maxwell, T. A.; Johnston, A. K.; Leuschen, C. J.; Schutz, A. E.; Williams, K. K.

2004-05-01

260

A temporary pond in the Early Cretaceous of southern England: palaeoclimatic implications of nonmarine "Purbeck-Wealden" ostracod faunas  

NASA Astrophysics Data System (ADS)

Excavation of the partial skeleton of an Iguanodon from the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks near Ockley, Surrey, UK included detailed sampling for micropalaeontological and palynological and studies (Nye et al., 2008). Rich and well-preserved non-marine assemblages of pollen and spores include early angiosperms as well as freshwater green algae. Taphonomic analyses show the ostracod assemblages to be autochthonous thanatocoenoses, indicative of local environment at the time of deposition. Using a palaeobiological approach, the ostracods and palynomorphs demonstrate temporary / ephemeral freshwater conditions at the time when the Iguanodon died and the carcase was buried. Ostracod "faunicycles" in "Purbeck-Wealden" deposits may represent salinity variations in non-marine water-bodies, influenced by the balance between precipitation and evaporation, and/or the relative abundance of permanent and temporary waterbodies in the landscape; many assemblages resulted from post-mortem mixing, perhaps during flood events (Horne, 2002). Faunal alternations may therefore reflect shifts of the boundary between warm temperate and paratropical climate in the Early Cretaceous of NW Europe. The previously rejected suggestion that such assemblage variations record Milankovitch cyclicity deserves to be reconsidered, as does the possibility that they reflect changes on sub-Milankovitch timescales. Climate variability may have influenced the differential evolutionary success of sexual, mixed and parthenogenetic reproductive strategies in nonmarine ostracods. Latitudinally restricted distribution patterns and wind dispersal of resting eggs offer potential for inferring global climate patterns from ostracod palaeobiogeography, although dispersal by large animals (e.g., crocodiles, pterosaurs) is likely to have confused any aeolian transport patterns. References Horne, D. J. 2002. Ostracod biostratigraphy and palaeoecology of the Purbeck Limestone Group in southern England. Special Papers in Palaeontology, 68, 1-18, 2 pls. Nye, E., Feist-Burkhardt, S., Horne, D. J., Ross, A. J. & Whittaker, J. E. (2008) The palaeoenvironment associated with a partial Iguanodon skeleton from the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks (Ockley, Surrey, UK), based on palynomorphs and ostracods. Cretaceous Research, 29, 417-444.

Horne, D. J.

2009-04-01

261

Volcanic risk and tourism in southern Iceland: Implications for hazard, risk and emergency response education and training  

NASA Astrophysics Data System (ADS)

This paper examines the relationship between volcanic risk and the tourism sector in southern Iceland and the complex challenge emergency management officials face in developing effective volcanic risk mitigation strategies. An early warning system and emergency response procedures were developed for communities surrounding Katla, the volcano underlying the Mýrdalsjökull ice cap. However, prior to and during the 2007 tourist season these mitigation efforts were not effectively communicated to stakeholders located in the tourist destination of Þórsmörk despite its location within the hazard zone of Katla. The hazard zone represents the potential extent of a catastrophic jökulhlaup (glacial outburst flood). Furthermore, volcanic risk mitigation efforts in Þórsmörk were based solely on information derived from physical investigations of volcanic hazards. They did not consider the human dimension of risk. In order to address this gap and provide support to current risk mitigation efforts, questionnaire surveys were used to investigate tourists' and tourism employees' hazard knowledge, risk perception, adoption of personal preparedness measures, predicted behaviour if faced with a Katla eruption and views on education. Results indicate that tourists lack hazard knowledge and they do not adopt preparedness measures to deal with the consequences of an eruption. Despite a high level of risk perception, tourism employees lack knowledge about the early warning system and emergency response procedures. Results show that tourists are positive about receiving information concerning Katla and its hazards and therefore, the reticence of tourism employees with respect to disseminating hazard information is unjustified. In order to improve the tourism sector's collective capacity to positively respond during a future eruption, recommendations are made to ensure adequate dissemination of hazard, risk and emergency response information. Most importantly education campaigns should focus on: (a) increasing tourists' knowledge of Katla, jökulhlaup and other volcanic hazards and (b) increasing tourist and employee awareness of the early warning and information system and appropriate behavioural response if a warning is issued. Further, tourism employees should be required to participate in emergency training and evacuation exercises annually. These efforts are timely given that Katla is expected to erupt in the near future and international tourism is an expanding industry in Þórsmörk.

Bird, Deanne K.; Gisladottir, Gudrun; Dominey-Howes, Dale

2010-01-01

262

Simulated Damping of Periodic Fluctuations in Net Infiltration Within a Thick Unsaturated Zone in Southern Nevada: Implications For Radionuclide Transport  

NASA Astrophysics Data System (ADS)

Arid and semiarid regions are historically preferred sites for radionuclide generating activities and waste disposal, in part because their unsaturated zones, typically having large thickness and low water content, are expected to inhibit the transport of contaminants to groundwater supplies. Through portions of the unsaturated zone that are heavily fractured, however, there is concern that transport in preferential flow paths might be relatively rapid on an episodic basis. Even so, fractured zones are commonly interrupted by lithologic units without substantial fractures, through which unsaturated flow might always be diffuse so as to damp out episodic fluctuations. In unsaturated-zone fractured units below such damping units, the initiation of preferential flow theoretically hinges on reaching a threshold moisture state, which depends on the magnitude of pressure and flux signals resulting from natural periodic variations in net infiltration. In diffuse unsaturated flow, periodic oscillations are damped to a quasi-steady state at sufficient distance from the inflow boundary. The resulting matric potential may be insufficient to trigger or sustain fracture flow through unsaturated media lying beneath those that facilitate damping. In general, shorter-period oscillations, longer distances of diffuse flow, and drier matrix conditions are conducive to damping. In this work we examine the damping of periodic recharge signals to a quasi-steady value, using analytical solutions for diffuse unsaturated flow, at Rainier Mesa and Shoshone Mountain in southern Nevada. Underground nuclear tests in previous decades introduced radionuclides into the unsaturated subsurface at these sites. Both sites have possible damping units greater than 100 m thick that are believed to be dominated by diffuse flow. Below these damping units lie fractured rocks in which preferential flow could resume, especially if the damping units are not sufficiently thick or dry. Effective damping of periodic recharge variations has the potential to suppress preferential flow initiation. Our simulations suggest that annual to decadal variations in net infiltration at these semiarid locations are damped to quasi-steady fluxes if diffuse unsaturated flow dominates within the thickness of the selected damping units. Sensitivity analysis shows that the estimated period to achieve damping is most sensitive to the unsaturated hydraulic properties of the media.

Ebel, B. A.; Nimmo, J. R.

2009-12-01

263

Spinel + quartz assemblage in granulites from the Achankovil Shear Zone, southern India: Implications for ultrahigh-temperature metamorphism  

NASA Astrophysics Data System (ADS)

We report the finding of equilibrium spinel + quartz assemblage enclosed within garnet in garnet-orthopyroxene-cordierite granulites from Pakkandom within the Achankovil Shear Zone, a region which is considered as the trace of an accretionary suture in recent tectonic models on southern India. The spinel + quartz bearing granulites are composed of poikiloblastic garnet and subidioblastic orthopyroxene in the matrix of quartz, plagioclase, biotite, cordierite, and Fe-Ti oxides. Garnet contains numerous inclusions of sillimanite and biotite as well as spinel and quartz. The spinel in direct contact with quartz has moderate XMg (= Mg/(Fe 2+ + Mg) = 0.44-0.47), and is Zn and Fe 3+ poor ( XZn = Zn/(Fe 2+ + Mg + Zn) = 0.027-0.036, Fe 3+/(Fe 2+ + Fe 3+) = 0.12-0.17). Spinel is also present in the matrix surrounded by magnetite, but the matrix spinel contains more Zn( XZn = 0.067-0.072) and does not show any contact relationship with quartz. Such Zn- and Fe 3+-poor spinel in direct contact with quartz has been regarded as a diagnostic evidence of ultrahigh-temperature (UHT) metamorphism. The high-temperature stability of the spinel + quartz is also supported by the results of geothermobarometric calculation of garnet-orthopyroxene assemblages that provides robust evidence for peak UHT metamorphism at 920-980 °C and 8-10 kbar, which was further confirmed by Al-in-Opx and magnetite-ilmenite geothermometers (900-950 °C and ˜1000 °C, respectively). The peak UHT event was followed by decompression down to 4.0-4.2 kbar and 640-670 °C toward the stability of cordierite along a clockwise P-T path. Similar spinel + quartz assemblage enclosed in poikiloblastic garnet has also been reported from the Palghat-Cauvery Shear Zone system, the trace of a major suture zone within the Gondwana amalgam with evidence for prograde high-pressure ( P up to 20 kbar) metamorphism followed by UHT event. The fine-grained spinel + quartz may thus indicate decompression from higher pressure conditions, confirming the recent attributes of the Achankovil Shear Zone being a collisional suture with evidence for subduction-exhumation processes which accompanied the final collision and amalgamation of the Gondwana supercontinent during the latest Neoproterozoic.

Shimizu, Hisako; Tsunogae, Toshiaki; Santosh, M.

2009-09-01

264

Deglaciation Chronology of the Southern Laurentide Ice Sheet and Implications for Meltwater Routing bracketing the Younger Dryas Event  

NASA Astrophysics Data System (ADS)

During the last glacial hemicycle the intricate interplay of ice sheet margin geometry, isostatic rebound, and topography dictated the locations of meltwater storage and routing. Perhaps the least well understood of these is the ice margin chronology. Consequently, we have developed ice margin chronologies at three potential outlets of the large meltwater reservoir in the center of North America known as glacial Lake Agassiz. At the southern outlet of Lake Agassiz, several channels cut across the Big Stone Moraine. Radiocarbon dates from depressions and an intermediate level meltwater channels indicate initial lake formation after 13,680 cal yr. Coupled with regional data this implies a minimum ice margin retreat of ~270 m/yr at the beginning of Bölling/Alleröd warm interval. The chronology of subsequent events and the location of the ice margin at the beginning of the Younger Dryas is still being studied. However, in order for the ice margin to retreat sufficiently to produce a volume of Lake Agassiz suggested in prior reconstructions for the start of the Younger Dryas requires retreat rates comparable to those of present day catastrophic collapse of the Columbia Glacier (~570 m/yr). The northwest outlet is via the Clearwater spillway of northern Alberta. New geomorphic mapping confirmed fluvial activity within the spillway, but also revealed several unrecognized ice margin positions. According to our reconstructions retreat rates from 15,000 cal yr to 12,400 cal yr average some 25 m/yr then increase to ~200 to 300 m/yr as the ice margin calving into water. The ice margin position could not allow for northward drainage until about 11,000 cal yr, well after the start of the Younger Dryas. The eastern outlet is of interest as the suggested location of meltwater change (flood or simple diversion) from the Gulf of Mexico to the North Atlantic. However, the lack of a clear geomorphic meltwater route is problematic. About 14,000 cal yr the ice sheet retreat rate increased to ~63 m/yr and continued at that pace until 12,100 cal yr at which time the ice margin crossed the lowest topographic pathway out of the Lake Agassiz basin. In this reconstruction the lowest pathway would not be available for meltwater flow until after the start of the Younger Dryas.

Lowell, T. V.; Fisher, T. G.; Waterson, N.; Hajdas, I.

2007-05-01

265

Environmental determinants of the distribution of Phlebotomus orientalis in Sudan.  

PubMed

Despite its importance as a vector of visceral leishmaniasis in Sudan, the ecology of Phlebotomus orientalis is still poorly understood. The results of a ground-based survey and a geographical-information-system (GIS) study, carried out to investigate the environmental determinants of the distribution of P. orientalis in the wooded areas of the central savannah belt of Sudan, are described here. The survey, carried out in April-June 1996, consisted of a collection of sandflies over two consecutive nights at each of 44 study sites, using three CDC, miniature, light traps at each site. During the survey, the ecology of each site was described. Phlebotomus orientalis was caught at 17 of the sites. Environmental data on the collection sites (rainfall, minimum and maximum temperatures, soil class, vegetation and land-surface-temperature indices) were extracted from a range of sources of digital data collected by satellites in the National Ocean and Atmospheric Administration's series. These data were then analysed, to ascertain which variables were significantly associated with sites positive for P. orientalis. In line with the results of previous studies, P. orientalis was found to have a significant association with the presence of the tree species Acacia seyal and Balanites aegyptiaca and with the black cotton (vertisolic) soils of eastern Sudan. The positive sites were found to have significantly higher annual mean maximum and minimum daily temperatures than the negative sites and the annual mean maximum normalized-difference vegetation index (NDVI) value was also found to be significantly higher in these sites than in sites where no P. orientalis were found. PMID:10396348

Elnaiem, D A; Connor, S J; Thomson, M C; Hassan, M M; Hassan, H K; Aboud, M A; Ashford, R W

1998-12-01

266

Minerals and trace elements in silcretes of the Sado basin (Alentejo, southern Portugal) and implications for silcrete formation  

NASA Astrophysics Data System (ADS)

Soils in the eastern part of the Sado basin (southern Portugal) are often characterized by massive cementations caused by silica. The thickness and massive character of these silcretes led to the hypothesis that accumulation of silica took place not only vertically within a soil profile, but also by enrichment through lateral water and element flow into the Sado basin. The aims of the study reported here were: 1) to characterize the cementing agent with regard to its mineralogy; 2) to test the hypothesis that silification was enhanced through lateral silica transport from the adjacent Alto Alentejo into the Sado basin. Aim 1) was achieved by scratching silica coatings from ped surfaces of the silicified soil horizons and cleaning them manually in the lab under a binocular microscope. After careful smashing with a mortar, density separation by sodium polytungstate solution was applied to remove any remaining mineral grains from the silica samples. The cleaned silica samples were then subjected to XRD and SEM in combination with EDS. Aim 2) was attained by using trace element contents of predominant rock types of the Alto Alentejo and of the silcretes in the Sado basin for identifying lateral pathways of water and silica in the landscape. Ten rock samples from the assumed source area of silica were combusted by fusion melt, and their contents of Ba, Co, Cs, Nb, Pb, Rb, Sr, Y and Zr were analyzed by ICP-MS. The same elements were analyzed in NaOH extracts of the cemented soil horizons in the Sado basin. The X-ray diagrams of the silica coatings show the expected broad hump of amorphous silica. In addition, quartz, kaolinite, and surprisingly high amounts of halloysite are identified, the latter reflecting conditions of intensive weathering and pedogenesis during the formation of the silica coatings. This intensive soil formation and hence silification most likely took place during Pliocene. Greater age is impossible, because the silification took place in Pliocene sediments; later, on the other hand, the climate became cooler, hence intensity of pedogenesis should have decreased. It is assumed that halloysite was preserved over such long period of time, because it was occluded in the silica mass. The micromorphology of the coatings under the SEM includes laminar coverings, banded and alveolar structures. EDS analysis shows that the coatings consist mainly of silicon; in addition they contain aluminum and some also have minor amounts of iron. Trace element contents of the rock samples and silcretes enabled tracing lateral silica flows from the Alto Alentejo into the Sado basin. Some rock samples and silcretes contained considerable amounts of Barium. Even barite crystals were observed in the silica coatings under the SEM. Acknowledgement The authors thank Beate Podtschaske for her valuable help in the laboratory and the German Research Foundation DFG for financial support (project STA 146/45-3).

Sauer, Daniela; Kullmann, Sarah; Zarei, Mehdi; Stahr, Karl

2014-05-01

267

U Pb geochronology of the Acatlán Complex and implications for the Paleozoic paleogeography and tectonic evolution of southern Mexico  

NASA Astrophysics Data System (ADS)

Even though the Acatlán Complex in southern Mexico contains the largest exposure of Paleozoic rocks in Mexico, it is commonly ignored in reconstructions of Pangea because of poor geochronologic data. Presently, this complex is understood to be composed of metasedimentary units (Cosoltepec, Magdalena, Chazumba and Tecomate Formations), a major magmatic suite (Esperanza Granitoids), and a suite with eclogites and blueschists (Xayacatlán Fm). Sedimentary cover includes unmetamorphosed upper Paleozoic units. Here we provide single-crystal laser ablation U-Pb geochronology of the metasedimentary and magmatic suites of the Acatlán Complex and its upper Paleozoic sedimentary cover. The data reveal a complex geological evolution recording tectonic events from the assembly of Rodinia to the break-up of Pangea. Data for the Esperanza Granitoids record three major tectonothermal events: (1) a Grenvillian (1165 ± 30 to 1043 ± 50 Ma), (2) a Taconian (478 ± 5 to 471 ± 5 Ma), and (3) a Salinian (Acatecan; 461 ± 9 to 440 ± 14 Ma). Eclogitic rocks from the Xayacatlán Formation of Neoproterozoic-Early Ordovician age contain detrital zircons derived most probably from the southwestern North America Grenville province. Data for the blueschists are consistent with a Middle Ordovician depositional age and derivation from Laurentian sources. The Tecomate Formation is composed of two unrelated units of contrasting age and lithology: a Neoproterozoic-Early Ordovician, arc- and rift-related volcanosedimentary unit containing detrital zircons derived from the southwestern North America Grenville province; and an essentially sedimentary unit containing Early Permian fauna. The Cosoltepec Formation has a maximum Devonian depositional age and contains detrital zircons consistent with derivation from South American sources. The age of the Magdalena and Chazumba Formations is established to be Late Pennsylvanian-Early Permian. These units contain detrital zircons indicating ultimate derivation from both North and South America crustal sources. The Late Paleozoic sedimentary cover contains detrital zircons shed mainly from Grenvillian sources with a significant contribution of Pennsylvanian magmatic rocks. The new U-Pb geochronologic data indicate that the traditional stratigraphic scheme used for the Acatlán Complex needs complete revision. Data further indicate that the earliest stages of the tectonic evolution of the Acatlán Complex are tied to the evolution of Rodinia and that the actual configuration of the Acatlán Complex was ultimately achieved by amalgamation of the Magdalena-Chazumba suite during the final stages of Pangea assembly. The Early Jurassic tectonothermal event affecting only the Chazumba and Cosoltepec units to produce the Magdalena Migmatite is related to the break-up of Pangea and the opening of the Gulf of Mexico. The Acatlán Complex contains a section of the suture between Laurentia and Gondwana with some sediments arriving from Laurentia and others from Gondwana and mirrors the structure and evolution of the Appalachian-Caledonian chains of North America.

Talavera-Mendoza, Oscar; Ruiz, Joaquín; Gehrels, George E.; Meza-Figueroa, Diana M.; Vega-Granillo, Ricardo; Campa-Uranga, María Fernanda

2005-07-01

268

Preliminary field trials of acrolein in the Sudan*  

PubMed Central

Field trials of acrolein for the simultaneous control of aquatic weeds and snails were conducted in the Sudan. Phytotoxicity studies at 25 and 50 ppm showed minor or no damage to furrow-irrigated crops, but flood irrigation of vegetable seedlings at 15 ppm was toxic. Effective downstream carriage of acrolein was demonstrated for a distance of 1.6 km at a concentration of 25 ppm. Planorbid snails (Bulinus and Biomphalaria) were almost completely eliminated (98-99% kills). All submersed aquatic weeds were destroyed.

Ferguson, Frederick F.; Dawood, Ismail K.; Blondeau, Rene

1965-01-01

269

PRELIMINARY FIELD TRIALS OF ACROLEIN IN THE SUDAN.  

PubMed

Field trials of acrolein for the simultaneous control of aquatic weeds and snails were conducted in the Sudan.Phytotoxicity studies at 25 and 50 ppm showed minor or no damage to furrow-irrigated crops, but flood irrigation of vegetable seedlings at 15 ppm was toxic.Effective downstream carriage of acrolein was demonstrated for a distance of 1.6 km at a concentration of 25 ppm. Planorbid snails (Bulinus and Biomphalaria) were almost completely eliminated (98-99% kills). All submersed aquatic weeds were destroyed. PMID:14310912

FERGUSON, F F; DAWOOD, I K; BLONDEAU, R

1965-01-01

270

Paleomagnetism of the Ocotillo Badlands, southern California, and implications for slip transfer through an antidilational fault jog  

NASA Astrophysics Data System (ADS)

The right-lateral Coyote Creek fault is the southernmost segment of the San Jacinto fault zone in California. At the Ocotillo Badlands, an anticlinorium of locally updomed material is exposed at a step-over between echelon segments of the fault. Here, uplift and deformation most probably result from multiple slip increments transferred across the antidilational fault jog, under the assumption that material away from the jog region deforms by rigid body translation. Within the 2 km wide fault jog, contraction has occurred by folding of the Quaternary sedimentary strata about east-west trending hinge lines. Structural analysis of this deformation shows that folding has accommodated ˜ 800 m of fault slip transferred through the antidilational jog. By comparison, total right slip on the Coyote Creek fault is 2.5 km, measured 25 km to the northwest at Coyote Ridge. A magnetostratigraphic study of the deformed strata was undertaken to determine the longevity of this fault discontinuity at the Ocotillo Badlands. The eroded core of the updomed material at the Ocotillo Badlands exposes a 325 m thick sequence of sedimentary rock, made up by the lacustrine Borrego Formation (˜ 200 m) and the overlying conglomeratic Ocotillo Formation (˜ 125 m). Stepwise thermal demagnetization of samples from the exposed strata suggests that the formation boundary also marks a magnetic polarity reversal, of reversed field to normal field as one travels upwards through the composite section. The inferred primary magnetization is probably produced by a detrital remanent magnetization (DRM) and is often overprinted with a weak, viscous present field component. Comparison with magnetostratigraphy of the Borrego Badlands 10 km to the northwest indicates that the reversal sampled is the onset of the Jaramillo event (0.97 Ma). The presence of a 20° angular unconformity within the upper portion of the exposed stratigraphy shows that deformation within the Ocotillo Badlands began during deposition of the Ocotillo Formation, shortly after the time of the field reversal. If total slip on the Coyote Creek fault at the Ocotillo Badlands is greater than 800 m, it appears that the fault jog has been a transitory feature within the fault zone, with slip alternately bypassing it or being transferred across it. Such switchyard behavior of slip transfer through the fault jog has important implications for understanding structural controls on earthquake rupture.

Brown, Norman N.; Fuller, Michael D.; Sibson, Richard H.

1991-03-01

271

Guns, Southernness, and gun control  

Microsoft Academic Search

Southerners have been found to have higher levels of gun ownership than persons who reside elsewhere. This may be due to cultural factors peculiar to the Southern region. If so, this would have interesting implications for gun control initiatives. Although the differential in gun ownership has been linked to varying support or opposition to gun control, the relationship between this

Pauline Gasdow Brennan; Alan J. Lizotte; David McDowall

1993-01-01

272

Visual detection of Sudan dyes based on the plasmon resonance light scattering signals of silver nanoparticles.  

PubMed

A visual light scattering detection method of Sudan dyes is reported in food products based on the formation of silver nanoparticles (NPs) . Sudan dyes including I, II, III and IV have reducibility due to the nitrogen-nitrogen double bond and phenol group in their molecular structure, and a redox reaction could occur with AgNO3. Owing to the formation of silver NPs as a result of the redox reaction, color changes could be observed by eye from the red of Sudan to the brown of silver NPs, resulting in strong plasmon resonance light scattering (PRLS) signals characterized at 452 nm, which could be measured using a common spectrofluorometer. It was found that the PRLS intensities were proportional to the dye concentrations over the range of 0.2-2.4 microM Sudan I, 0.1-2.4 microM Sudan II, 0.1-2.4 microM Sudan III, and 0.2-3.0 microM Sudan IV, with the corresponding limits of determination (3 sigma) of 3.2, 3.0, 3.2, and 2.9 nM, respectively. Using hot chili as a model sample, detection could be made with the recovery of 90.8-103.3% and RSD of 4.0-4.9%, and the results are identical with that of a liquid chromatographic method approved by the European Commission. To make the PRLS method much more practical, we could visually detect the quantity of Sudan dyes based on the PRLS signals using simple devices such as a portable laser pointer (653 nm) and a light emitting diode (458 nm). Mechanism investigations show that the functional group of Sudan oxidized by AgNO3 is the phenol group, not the nitrogen-nitrogen double bond. PMID:16878897

Wu, Li Ping; Li, Yuan Fang; Huang, Cheng Zhi; Zhang, Qin

2006-08-01

273

Sahara Desert, Sudan, Northeast Africa as seen from STS-62  

NASA Technical Reports Server (NTRS)

This east-looking view shows most of the east-west extent of the country of Sudan. The foreground shows a vegetationless and almost uninhabited region of northwest Sudan. The rich earth colors are ancient soils (browner and redder tones), a concentrated mass of what may be volcanic cinder cones (dark brown dots - center) and dune and younger river sediments (yellows). The photo would have been difficult to locate had it not been for two recognizable features in the background: a visually well-know inselberg ('island mountain' - top center) on the large west-bank tributary of the White Nile; and the confluence of the Blue and White Nile Rivers, with the great cotton developments of the Gezira Scheme between them (top left). The Red Sea coast is almost obscured by a dust cloud but can be discerned running across the top of the picture. The clouds at top may be developing over the coastal ranges of Saudi Arabia beyond the Red Sea.

1994-01-01

274

Mineral composition of renal stones from the Sudan.  

PubMed

Urolithiasis is a very frequent finding in the Sudan, but stone analysis is not routinely performed in this country. It would, however, give important evidence for the metabolic basis of stone formation. We therefore set out to analyze urinary stones in 80 Sudanese patients (45 male, 35 female), 12 of whom where children. Fourier-transformed infrared spectroscopy was used for stone analysis. As is known from other countries, calcium oxalate (CaOx) stones were the most frequent, with 68.7% of all stones in adults and 43.7% of childhood stones. Uric acid and uric acid dihydrate stones were more often seen in adults (13.2%) than in children (4. 1%). Ammonium urate stones are common in the Sudan, especially in children (32.9%), which is typical for underdeveloped countries. Infectious stones (struvite and carbonate apatite) were more often found in women (7.0%) and in children (5.3%) than in men (1.4%). Brushite stones were seldom seen and cystine stones did not occur. PMID:9933835

Balla, A A; Salah, A M; Khattab, A H; Kambal, A; Bongartz, D; Hoppe, B; Hesse, A

1998-01-01

275

Electrochemical Determination of Trace Sudan I Contamination in Chili Powder at Carbon Nanotube Modified Electrodes  

PubMed Central

We have developed a simple, convenient and inexpensive voltammetric method for determining trace Sudan I contamination in chili powder, based on the catalyzed electrochemical reduction of Sudan I at the carbon nanotube modified electrode. Under optimized conditions, the method exhibited acceptable analytical performance in terms of linearity (over the concentration range 6.0×10?7 to 7.5×10?5 M, r = 0.9967), detection limit (2.0×10?7 M) and reproducibility (RSD = 4.6%, n=10, for 2.0×10?5 M Sudan I).

Ming, Liang; Xi, Xia; Chen, Tingting; Liu, Jie

2008-01-01

276

Onchocerciasis in Sudan: the distribution of the disease and its vectors.  

PubMed

The distribution of onchocerciasis and its vectors in Sudan has been reviewed with special emphasis on the hyperendemic foci where there is serious visual handicap caused by the disease. These blinding foci lie primarily in the south-west of the country, along the rivers flowing north and east from the borders with Central African Republic and Zaire, though at least one such focus is known from the eastern part of the country close to the Ethiopian border. In the blinding foci, often small villages localized to short stretches of the rivers, ocular onchocerciasis is as severe as that found in any other African foci. Only the S. damnosum s.l. species complex has been implicated in disease transmission and only the two dangerous, morphologically similar, savanna cytospecies, S. damnosum s.s. and S. sirbanum, have been identified from breeding sites close to known onchocerciasis foci. Near to the Uganda and Zaire borders it is very likely that other, less anthropophilic, cytospecies occur. Different Onchocerca-Simulium complexes (different strains of parasite with different pathogenicities transmitted by different vector species) may be responsible for the different severities of disease found in the 3 main areas of onchocerciasis in North, East and South-West Sudan. The localized, focal distribution of the communities seriously blinded by onchocerciasis, suggests that a strategy of tackling the disease on a focus basis may prove optimal. A control scheme, planned to treat all the vector breeding sites with insecticide, as in West Africa, would receive extensive invasion from the Zaire/Congo River Basin and the headwaters of the White and Blue Niles in neighbouring countries. While some foci are situated beside major river rapids, with vector breeding only controllable by regular insecticide treatments, several foci have been identified as lying close to removable man-made objects which provide excellent breeding sites at certain water levels e.g. causeways. The destruction of such breeding sites should be considered since localized vector control may produce substantial reductions in onchocerciasis transmission. PMID:3551025

Baker, R H; Abdelnur, O M

1986-12-01

277

[Simultaneous determination of canthaxanthin and Sudan Red in salted duck egg yolk by reversed-phase high performance liquid chromatography].  

PubMed

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of canthaxanthin, Sudan Red I , Sudan Red II , Sudan Red III and Sudan Red IV in salted duck egg yolk has been developed. These canthaxanthin and Sudan Red dyes were extracted with a mixture of acetonitrile, methanol, and chloroform (1 : 0.5 : 0.5, v/v). The extract was dried by a rotary evaporator. The residue was transferred to a graduated tube and diluted to 10 mL with acetonitrile. The canthaxanthin and Sudan Red dyes were separated on a XDB-C18 column (250 mm x 4.6 mm), with acetonitrile-water (95:5, v/v) as mobile phase. They were then detected at 478 nm - 520 nm - 471 nm at different retention times by UV/Vis spectrophotometer. The recoveries of sudan I , sudan II, sudan II, sudan IV, and canthaxanthin were 97.34%, 89.56%, 90.98%, 93.63% and 95.15% respectively. The relative standard deviations (RSDs) were 4.7%, 4.3%, 5.1%, 4.9% and 3.1%, respectively. The method is simple, rapid and accurate. PMID:18257306

Wang, Quanlin; Shi, Pingping; Zhang, Shufen; Shen, Jian; Fu, Xiao

2007-11-01

278

Mechanism of formation of (deoxy)guanosine adducts derived from peroxidase-catalyzed oxidation of the carcinogenic nonaminoazo dye 1-phenylazo-2-hydroxynaphthalene (Sudan I).  

PubMed

We investigated peroxidase-mediated oxidation of and the formation of the (deoxy)guanosine adduct by 1-phenylazo-2-hydroxynaphthalene (Solvent Yellow 14, Sudan I), a liver and urinary bladder carcinogen for rodents and a potent contact allergen and sensitizer for humans. Using thin layer chromatography (TLC) and/or high performance liquid chromatography (HPLC) combined with mass and/or nuclear magnetic resonance (NMR) spectrometry, we characterized the structures of two major peroxidase-mediated Sudan I metabolites and those of the adducts of (deoxy)guanosine that are formed during Sudan I oxidation. Peroxidase oxidizes Sudan I to radical species that react with another Sudan I radical to form the Sudan I dimer, or in the presence of (deoxy)guanosine, the oxidized Sudan I can attack the exocyclic amino group of guanine, forming the 4-[(deoxy)guanosin-N(2)-yl]Sudan I adduct. The reaction product with a second Sudan I radical results in a dimer where the oxygen 2 radical of Sudan I reacted with carbon 1 in the second Sudan I skeleton. The Sudan I dimer is unstable and decomposes spontaneously to the second oxidation product. This compound consists of the 4-oxo-Sudan I skeleton connected via the oxygen of its 2-hydroxyl group and nitrogen of its azo group with carbon 1 of 2-oxonaphthalene, having a unique spironaphthooxadiazine structure. If (deoxy)guanosine is present during the formation of this Sudan I metabolite, an adduct, in which this Sudan I metabolite is bound to the exocyclic amino group of guanine, is generated. This (deoxy)guanosine adduct is again unstable and decomposes spontaneously to the same adduct that is formed by the direct reaction of oxidized Sudan I, the 4-[(deoxy)guanosin-N(2)-yl]Sudan I adduct. The results presented here are the first structural characterization of Sudan I-(deoxy)guanosine adducts formed during the oxidation of this carcinogen by peroxidase. PMID:19813759

Dracínský, Martin; Cvacka, Josef; Semanská, Marcela; Martínek, Václav; Frei, Eva; Stiborová, Marie

2009-11-01

279

Famine Early Warning System Vulnerability Assessment. Contains Reports on Mauritania, Mali, Burkina, Niger, Chad, Sudan, Ethiopia.  

National Technical Information Service (NTIS)

The report assesses food security in seven countries in the Sahel region of Africa - Mauritania, Mali, Burkina Faso, Niger, Chad, Sudan, and Ethiopia - focusing on the socioeconomic factors that affect access to food. While the report's analysis is countr...

1990-01-01

280

3 CFR - Continuation of the National Emergency With Respect to Sudan  

Code of Federal Regulations, 2013 CFR

...d)), I am continuing for 1 year the national emergency with respect to Sudan. This notice shall be published in the Federal Register and transmitted to the Congress.BARACK OBAMATHE WHITE HOUSE, November 1,...

2013-01-01

281

Determination of para red, Sudan dyes, canthaxanthin, and astaxanthin in animal feeds using UPLC.  

PubMed

A simple high-performance liquid chromatography method was developed for quantitative determination of para red, Sudan I, Sudan II, Sudan III, Sudan IV, canthaxanthin, and astaxanthin in feedstuff. The sample was extracted using acetonitrile and cleaned up on a C(18) SPE column. The residues were analyzed using ultra-performance liquid chromatography coupled to a diode array detector at 500 nm. The mobile phase was acetonitrile-formic acid-water with a gradient elution condition. The external standard curves were calibrated. The mean recoveries of the seven colorants were 62.7-91.0% with relative standard deviation 2.6-10.4% (intra-day) and 4.0-13.2% (inter-day). The detection limits were in the range of 0.006-0.02 mg/kg. PMID:20056031

Hou, Xiaolin; Li, Yonggang; Wu, Guojuan; Wang, Lei; Hong, Miao; Wu, Yongnin

2010-01-01

282

[IR, Raman and DFT studies of Sudan red III and IV].  

PubMed

Infrared spectroscopy (IR) and normal Raman spectroscopy (NRS) of Sudan red(III) and Sudan red(IV), and surface -enhanced Raman spectroscopy(SERS) of them on Cu-Ag nanocomposite material were reported in the present paper. The density functional theory (DFT) calculation was applied to calculate IR and NRS on a B3LYP/6-311+G (d, p) level, and the theoretically calculated spectra were carefully compared with the obtained experimental spectra. The vibrational peaks were assigned by the software of Gauss view 5.0. Rapid identification of Sudan red was realized, which provided profitable basis for characteristics and quick test of Sudan dyes, and reliable detection method of food security. PMID:23427545

Dou, Wen-Hu; He, Qiang; Zhou, Guang-Ming; Kang, Qian-Qian; Yang, Yuan-Gao; Chen, Jun

2012-12-01

283

Steps Towards the Stabilization of Governance and Livelihoods in Darfur, Sudan.  

National Technical Information Service (NTIS)

This paper was commissioned in accordance with USAID Scope of Work for analytical services in support of USAID stabilization activities in the Sudan. The objective is to provide technical assistance to identify and develop program strategies to: (1) stabi...

A. DeWaal H. Young

2005-01-01

284

Primary investigation of 31 infants with suspected congenital rubella syndrome in Sudan.  

PubMed

Between 2005 and 2006, clinical specimens were collected from 31 infants with suspected congenital rubella syndrome (CRS) who presented at six hospitals in Khartoum, Sudan. Eleven (35.5%) were laboratory confirmed as CRS cases by testing for anti-rubella IgM, IgG and viral genome. For the first time in Sudan, the rubella virus genome was directly detected in clinical specimens of six CRS cases and two viruses were isolated in cell culture. Phylogenetic analysis suggested that three genotypes of rubella virus (RV; 1E, 2B and 1G) were co-circulating in Sudan. The study introduced the methodology for CRS confirmation and surveillance in Sudan and provides preliminary data. PMID:19732080

Omer, A; Abdel Rahim, E-H; Ali, E-E; Jin, L

2010-06-01

285

Humanitarian crisis continues to grow in the Sudan  

NSDL National Science Digital Library

This week the already grave situation in the western region of the Sudan (known as Darfur) continued to grow even worse, as the United Nations called for a larger international monitoring force to quell attacks on civilians by members of the Arab militia in the country. In a report made to the U.N. Security Council this week, Secretary-General Kofi Annan remarked that such a monitoring force was necessary in order to help "decrease the level of violence and enhance the protection of the civilian population". The origins of the crisis date back to February 2003 when two African rebel factions brought arms in order to protest alleged discrimination by the largely Arab-dominated government located in the nation's capital at Khartoum. The tension has complex roots, but some of the problems are centered around disputes dealing with land and grazing rights between the nomadic Arabs in the region and farmers from the Fur, Massaleet and Zagawa ethnic groups. Since the conflict started last year, close to one million people have fled their homes and approximately 50,000 people have been killed.The first link will take visitors to a news article from the Guardian that offers a report on the recent call from the United Nations to increase the international monitoring force in the Sudan. The second link leads to a news brief from the U.N. News Centre that talks about the precarious situation of those displaced residents of the Darfur region. The third link provided by the BBC answers a host of questions about the current situation in the Darfur region, including helpful background information about the various groups involved. The fourth link leads to the homepage of the Sudanese Media Centre, where visitors may find editorial pieces, browse through special reports, and read their various press releases. The fifth link leads to an informative report from June 2004 prepared for the House of Commons in the British Parliament on the conflict in Darfur. The final link will take visitors to the transcript of a recent interview conducted by the U.N. Office for the Coordination of Humanitarian Affairs with Al Zhawi Ibrahim, who serves as the Minister for Information and Communications for the Sudan. In the interview, he speaks about the postwar challenges that will face the country, and of course, the situation in Darfur.

286

Synsedimentary deformation of Pleistocene glaciolacustrine deposits in the Albese con Cassano Area (Southern Alps, Northern Italy), and possible implications for paleoseismicity  

NASA Astrophysics Data System (ADS)

We describe and interpret the well exposed soft-sediment deformations preserved in a Mid-Pleistocene proglacial sequence outcropping at Albese con Cassano, near Como (Southern Alps, N Italy). The observed deformations affect six distinct stratigraphic intervals within the same depositional sequence. The stratigraphy of this sequence, the geomorphic setting, and the careful geological mapping of the area clearly show that these deformations are not the result of glaciotectonics or cryoturbation, but are due to six separate events of synsedimentary liquefaction. In particular, the 3 basal deformed units include sand and gravel volcanoes that formed at the bottom of a proglacial lake. We examined several hypothesis of possible causative mechanism for the formation of these features. Taking into account all the information available on the local geology and sedimentary environment, it is possible to assess that the liquefaction features at Albese con Cassano had a coseismic origin. To our knowledge, this would be the first report of similar evidence of paleoseismicity in the Lombardia Southern Alps. Also, there is no record of historical liquefaction triggered by seismic events in an area of ca. 70 km of radius near Albese con Cassano, including the town of Como, the large metropolitan area of Milano and most of W Lombardia, that is one of the largest industrial districts in Europe. Therefore, the interpretation of the observed deformations can have critical impact for understanding the current seismicity level in the region, and mitigating the associated risk. In this paper we show that this interpretation is not a simple process. Liquefaction features must be treated with caution in order to derive suitable information for seismic hazard characterization, even if their coseismic origin has been definitely proved. It is necessary to understand the amount of seismic shaking (for instance, in terms of local macroseismic intensity) that can have produced that specific feature at that specific site, the location of the causative seismic event (epicenter and focal depth), and eventually its size (in terms of epicentral intensity and/or earthquake magnitude). In the case of Albese con Cassano, the implications in terms of seismic hazard of the observed possible earthquake paleoliquefactions can only be assessed through the definition of several scenarios, taking into account: a) different thresholds of shaking for triggering the described synsedimentary structures, and b) different seismotectonic frameworks related to the Mid-Pleistocene to Holocene evolution of the S Alps, including seismicity induced by isostatic glacial rebound. We conclude that it is worth checking these scenarios in the field with further paleoseismological research on other possible evidence of past earthquakes. There are no unequivocal sedimentological indicators of paleoseismicity, however, when carefully interpreted within the proper local seismotectonic context and compared with other earthquake-induced features, soft-sediment deformations can offer information of critical value for seismic hazard assessment.

Chunga, Kervin; Livio, Franz; Michetti, Alessandro M.; Serva, Leonello

2007-03-01

287

Comprehensive impurity profiling and quantification of Sudan III dyes by gas chromatography/mass spectrometry.  

PubMed

A novel analysis strategy was created for comprehensive qualitative and quantitative impurity profiling of the coloring agent Sudan III by gas chromatography/mass spectrometry (GC/MS). The identification of impurities in commercial Sudan III was performed by GC/MS combined with trimethylsilylation (TMS). A total of 24 impurities were identified or tentatively characterized in commercial Sudan III dyes by GC/MS and were mainly classified as phenylazo and naphtholazo analogs. Four new impurities with coplanar structures, suspected of being toxic compounds, were observed in commercial Sudan III dyes. For further identification and sensitive detection of polar impurities, an extract was trimethylsilyl-derivatized to improve the GC chromatographic properties and mass spectrometric detection sensitivity. On the basis of the impurities identified by GC/MS, pathways for the formation of the major impurities during the manufacture of Sudan III were suggested. Four impurities regulated by the EU commission and the US Code of Federal Regulations (CFR) in Sudan III were quantified by GC/MS-scan mode. Method validation was conducted to determine linearity, precision, accuracy, and limit of quantification (LOQ). The linear dynamic range extended from 0.001 to 4.0%, with a correlation coefficient (R(2)) greater than 0.997 for GC/MS. The LOQs of the impurities ranged from 2.73 to 4.39?g/g for GC/MS. Based on the established method, the levels of regulated impurities in five commercial Sudan III dyes manufactured by different chemical companies were successfully determined. This study provides very useful information for the quality control of Sudan III and evaluation of its manufacture. PMID:23726074

Hong, Ji Yeon; Park, Na Hyun; Yoo, Kyung Ho; Hong, Jongki

2013-07-01

288

Benzenediazonium ion derived from Sudan I forms an 8-(phenylazo)guanine adduct in DNA.  

PubMed

1-(Phenylazo)-2-hydroxynaphthalene (Sudan I, Solvent Yellow 14) is a liver and urinary bladder carcinogen in mammals. Sudan I forms benzenediazonium ion during cytochrome P-450 catalyzed metabolism. Calf thymus DNA was reacted with Sudan I activated by microsomal enzymes or with benzenediazonium ion in vitro, and the adducts formed were analyzed by the 32P-postlabeling technique. Both enrichment procedures (1-butanol extraction and nuclease P1 digestion) of this technique were employed for detection and quantitation of the DNA adducts formed. Cochromatographic analyses of adduct spots obtained by reaction with DNA or homopolydeoxyribonucleotides showed that the major Sudan I-DNA adduct was formed with deoxyguanosine. This adduct was also found in DNA directly reacted with benzenediazonium ion. The major Sudan I-DNA adduct was characterized by UV/vis absorbance spectroscopy as well as by the chromatographic properties of the adduct on cellulose or poly(ethylenimine)--cellulose TLC and HPLC. The characteristics are identical to those of the adduct synthesized from benzenediazonium ion and guanine, identified by mass, UV/vis, and 1H-NMR spectroscopy as 8-(phenylazo)guanine. The results suggest strongly that benzenediazonium ion derived from Sudan I reacts with DNA in vitro to form the stable 8-(phenylazo)guanine adduct. PMID:7548728

Stiborová, M; Asfaw, B; Frei, E; Schmeiser, H H; Wiessler, M

1995-06-01

289

Determination of Sudan dye residues in eggs by liquid chromatography and gas chromatography-mass spectrometry.  

PubMed

A sensitive and cheap high performance liquid chromatography (HPLC) with ultraviolet-visible (UV-VIS) was developed for the determination of Sudan dyes (I, II, III, and IV) residues in various types of eggs. The chromatographic separation was achieved on a reverse phase C18 column with gradient elution, using a mobile phase of 0.1% formic acid acetonitrile/0.1% formic acid aqueous solution; detector was set at 478 nm for Sudan I and 520 nm for Sudan II, III and IV. The suspected egg samples were derivatized with N,O-bis (trimethylsilyl) trifluoro-acetamide and confirmed by gas chromatography-mass spectrometry (GC-MS) in EI. Mass spectra of trimethylsilyl derivatives of the Sudan dyes were built up in EI mode. Recoveries of the Sudan dyes ranged between 79.8 and 95.7% in eggs by HPLC-UV, with all the relative standard deviations of less than 5%. Limit of detection (LOD), limit of quantification (LOQ) were in the range of 4.0-4.8 and 12.3-13.8 microg kg(-1) in eggs, respectively. Identification and confirmation could be validated in the range of 2.0-4.2 microg kg(-1) with the GC-MS method. This method is suitable for routine fast monitoring, screening and confirmation of Sudan dyes residues in eggs, as mandated by regulatory agencies. PMID:17560395

He, Limin; Su, Yijuan; Fang, Binghu; Shen, Xiangguang; Zeng, Zhenling; Liu, Yahong

2007-06-26

290

Population Genetics of Trypanosoma evansi from Camel in the Sudan  

PubMed Central

Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of microorganisms. We have investigated genetic variation at 15 microsatellite loci of T. evansi isolated from camels in Sudan and Kenya to evaluate the genetic information partitioned within and between individuals and between sites. We detected a strong signal of isolation by distance across the area sampled. The results also indicate that either, and as expected, T. evansi is purely clonal and structured in small units at very local scales and that there are numerous allelic dropouts in the data, or that this species often sexually recombines without the need of the “normal” definitive host, the tsetse fly or as the recurrent immigration from sexually recombined T. brucei brucei. Though the first hypothesis is the most likely, discriminating between these two incompatible hypotheses will require further studies at much localized scales.

Salim, Bashir; de Meeus, Thierry; Bakheit, Mohammed A.; Kamau, Joseph; Nakamura, Ichiro; Sugimoto, Chihiro

2011-01-01

291

Putting the capacity into capacity building in South Sudan.  

PubMed

This paper discusses the benefits of training local people to become community health workers in south Sudan. Joyce Kiden relates her experiences as a health worker and gives a detailed account on the benefits of the work as well as the fulfillment of helping others. Despite some challenges and difficulties, the training that was organized by WHO has made considerable impact on the improvement of primary health care services at the community level. Many agencies realize importance of community health workers training. These training enhances the basic skills of people and hopefully encourage international donors to support not just the international organizations that are vital, but also the local people who will make improving health a sustainable possibility. PMID:10968446

Bower, H

2000-08-19

292

Anaerobic metabolism of 1-amino-2-naphthol-based azo dyes (Sudan dyes) by human intestinal microflora.  

PubMed

The rates of metabolism of Sudan I and II and Para Red by human intestinal microflora were high compared to those of Sudan III and IV under anaerobic conditions. Metabolites of the dyes were identified as aniline, 2,4-dimethylaniline, o-toluidine, and 4-nitroaniline through high-performance liquid chromatography and liquid chromatography electrospray ionization tandem mass spectrometry analyses. These data indicate that human intestinal bacteria are able to reduce Sudan dyes to form potentially carcinogenic aromatic amines. PMID:17933925

Xu, Haiyan; Heinze, Thomas M; Chen, Siwei; Cerniglia, Carl E; Chen, Huizhong

2007-12-01

293

Regional Variations in Upper Mantle Compressional Velocities Beneath Southern California 1. Post-Shock Temperatures: Their Experimental Determination, Calculation, and Implications, 2..  

National Technical Information Service (NTIS)

The compressional velocity within the upper mantle beneath Southern California is investigated through observations of the dependence of teleseismic P-delays at all stations of the array on the distance and azimuth to the event. The variation of residuals...

S. A. Raikes

1978-01-01

294

This is a text only version for Open-File Report 03-200 Geophysical Identification and Geological Implications of the Southern Alaska Magnetic Trough  

Microsoft Academic Search

The southern Alaska magnetic trough (SAMT) is one of the fundamental, crustal-scale, magnetic features of Alaska. It is readily recognized on 10 km upward-continued aeromagnetic maps of the state. The arcuate SAMT ranges from 30 to 100 km wide and extends in two separate segments along the southern Alaska margin for about 1200 km onshore (from near the Alaska\\/Canada border

R. W. Saltus; T. L. Hudson; F. H. Wilson

295

Lithospheric extension northwest of the Central African Shear Zone in Sudan from potential field studies  

NASA Astrophysics Data System (ADS)

The Central African Shear Zone (CASZ) is a 4000-km-long, NE-striking wrench fault system, along which motion occurred during the break-up of Gondwanaland, but its location in central Sudan was poorly defined. Prior to this study, it was thought that Mesozoic extension was restricted to Sudan south of the mapped and proposed location of the CASZ. We use nearly all gravity data from Sudan, including 1894 unpublished gravity points in eastern Sudan to (1) clarify the position of the CASZ in central and eastern Sudan and to (2) interpret anomalies northwest of the CASZ with similar trends and amplitudes as those basins known to occur southeast of the CASZ. Considering the dimensions of these gravity minima and existing geological, aeromagnetic, magneto-telluric, seismic and well data, we suggest that fault-bounded sedimentary basins lie north of the CASZ in central and eastern Sudan. We construct geological models of the Bara, Bagbag, Humar, Gilif and Abu Dulu rift basins to investigate the subsurface geometry of these previously undetected basins, constraining models with existing geological and geophysical data. The detrended gravity profiles can be fit by 40-60-km-wide basins bounded on one or both sides by normal fault systems, and with depths of 1.5-3.5 km. These patterns suggest that the CASZ in central and eastern Sudan is a broader zone of deformation than had previously been considered. The < 10 km cumulative Mesozoic extension within the African plate north of the CASZ implied by these studies, however, will not change significantly current plate models for the break-up of Africa and South America.

Ibrahim, A. E.; Ebinger, C. J.; Fairhead, J. D.

1996-04-01

296

Sudan I induces genotoxic effects and oxidative DNA damage in HepG2 cells.  

PubMed

Sudan I, a synthetic lipid soluble azo pigment, is widely used in various industrial fields. However, Sudan I has not been approved at any level of food production, since there are many inconclusive reports relating to its genotoxicity and carcinogenicity in humans. The aim of this study was to assess the genotoxic effects of Sudan I and to identify and clarify the reaction mechanisms by use of human hepatoma HepG2 cells. To study the genotoxic effects of Sudan I, the comet assay and micronucleus test (MNT) were used. In the comet assay and MNT, we found increase of DNA migration and of the micronuclei frequencies at all tested concentrations (25-100 microM) of Sudan I in a dose-dependent manner. The data suggest that Sudan I caused DNA strand breaks and chromosome breaks. To elucidate the underlying mechanism of this difference, we monitored the level of reactive oxygen species (ROS) production with the 2,7-dichlorofluorescein diacetate assay. The level of the oxidative DNA damage and lipid peroxidation was evaluated using immunoperoxidase staining for 8-hydroxydeoxyguanosine (8-OHdG) and by measuring levels of thiobarbituric acid-reactive substances (TBARS). Significantly increased levels of ROS, 8-OHdG and TBARS were observed in HepG2 cells at higher concentrations, the doses being 100, 50-100 and 50-100 microM, respectively. We conclude that Sudan I causes genotoxic effects, probably via ROS-induced oxidative DNA damage at the higher doses. PMID:17188558

An, Yu; Jiang, Liping; Cao, Jun; Geng, Chengyan; Zhong, Laifu

2007-03-01

297

Evaluation of impact of exposure of Sudan azo dyes and their metabolites on human intestinal bacteria.  

PubMed

Sudan azo dyes are banned for food usage in most countries, but they are illegally used to maintain or enhance the color of food products due to low cost, bright staining, and wide availability of the dyes. In this report, we examined the toxic effects of these azo dyes and their potential reduction metabolites on 11 prevalent human intestinal bacterial strains. Among the tested bacteria, cell growth of 2, 3, 5, 5, and 1 strains was inhibited by Sudan I, II, III, IV, and Para Red, respectively. At the tested concentration of 100 ?M, Sudan I and II inhibited growth of Clostridium perfringens and Lactobacillus rhamnosus with decrease of growth rates from 14 to 47%. Sudan II also affected growth of Enterococcus faecalis. Growth of Bifidobacterium catenulatum, C. perfringens, E. faecalis, Escherichia coli, and Peptostreptococcus magnus was affected by Sudan III and IV with decrease in growth rates from 11 to 67%. C. perfringens was the only strain in which growth was affected by Para Red with 47 and 26% growth decreases at 6 and 10 h, respectively. 1-Amino-2-naphthol, a common metabolite of the dyes, was capable of inhibiting growth of most of the tested bacteria with inhibition rates from 8 to 46%. However, the other metabolites of the dyes had no effect on growth of the bacterial strains. The dyes and their metabolites had less effect on cell viability than on cell growth of the tested bacterial strains. Clostridium indolis and Clostridium ramosum were the only two strains with about a 10 % decrease in cell viability in the presence of Sudan azo dyes. The present results suggested that Sudan azo dyes and their metabolites potentially affect the human intestinal bacterial ecology by selectively inhibiting some bacterial species, which may have an adverse effect on human health. PMID:22634331

Pan, Hongmiao; Feng, Jinhui; He, Gui-Xin; Cerniglia, Carl E; Chen, Huizhong

2012-08-01

298

Preparation of anti-Sudan red monoclonal antibody and development of an indirect competitive enzyme-linked immunosorbent assay for detection of Sudan red in chilli jam and chilli oil.  

PubMed

Sudan dyes are banned to be used in food additives because of the carcinogenicity of their metabolites. A rapid and sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed to detect the residues of Sudan dyes. Novel immunogen and coating antigen were synthesized via glutaraldehyde linking. The hapten-bovine serum albumin (BSA) was applied as immunogen and the hapten-ovalbumin (OVA) was served as coating antigen. The monoclonal antibody obtained showed high sensitivity to Sudan I with an IC(50) value of 1.7 ?g L(-1) in buffer and was suitable to detect the residues of Sudan red in food products. The specificity of the assay was studied by measuring cross-reactivity of the antibody with the structurally related compounds of Sudan II (<1%), Sudan IV (<1%) and para red (120%). Chilli jam and chilli oil samples spiked with Sudan dyes were analyzed by the method. The detection limit (LOD) of the ELISA method applied in chilli jam and chilli oil was 9.0 ?g L(-1) and 19.6 ?g L(-1), respectively. The recovery rates of Sudan-I in chilli oil and chilli jam were in the range of 80%-110% with coefficients of variation <25%. The intra-assay variation and inter-assay variation in buffer were both <9%. PMID:20689866

Xu, Jing; Zhang, Yuanyang; Yi, Jian; Meng, Meng; Wan, Yuping; Feng, Caiwei; Wang, Shanliang; Lu, Xiao; Xi, Rimo

2010-10-01

299

15 CFR Supplement No. 2 to Part 742 - Anti-Terrorism Controls: Iran, North Korea, Syria and Sudan Contract Sanctity Dates and Related...  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Anti-Terrorism Controls: Iran, North Korea, Syria and Sudan Contract...Part 742âAnti-Terrorism Controls: Iran, North Korea, Syria and Sudan Contract...Secretary of State has designated Cuba, Iran, North Korea, Sudan and Syria as...

2009-01-01

300

Multi-determination of Para red and Sudan dyes in egg by a broad specific antibody based enzyme linked immunosorbent assay  

Microsoft Academic Search

Para red and Sudan dyes (Sudan 1, 2, 3, 4, and Sudan G) have been proven to show the potential carcinogenic effect to human. This study first reported an indirect competitive immunoassay (ELISA) for simultaneous detection of the six red dyes in egg. Two immunogens of Para red were prepared by coupling the deoxidized Para red to carrier protein by

Xiang Cai Chang; Xiu Zhi Hu; Yan Qin Li; Yan Jiao Shang; Yan Zheng Liu; Gao Feng; Jian Ping Wang

2011-01-01

301

Factors affecting unmet need for family planning in Eastern Sudan  

PubMed Central

Background In the developing countries millions of women in the reproductive age who don’t use contraceptives prefer to postpone or limit their birth. This indicates their failure to take necessary decision to prevent and avoid unwanted pregnancy. Methods A community-based cross sectional household survey was conducted to investigate unmet need for family planning and associated factors and total demand for family planning in Kassala, Eastern Sudan between 1st May and 31st July 2012. Results A total of 812 married women were enrolled in this study. Their mean age and parity was 31.8 (7.3) and 3.4 (1.8) respectively. Ever use of contraception was 25.4% (206/812) and 26.2% (213/812) were currently using contraception. Unmet need for spacing was 15.1% while unmet need for limiting was 0.7%. The pregnant and amenorrheic women whose the pregnancy or birth was unwanted and mistimed were 105 (13%) and 130 (16%) respectively. Using Westoff model the total unmet need was estimated as 44.8%. The total demand for family planning was 71%. In logistic regression model, while age, age at marriage, parity, residence and experience of child death were not associated with total unmet need for family planning, women education < secondary level (OR=7.8; CI=5.6-10.9; P=0.00), husband education < secondary level (OR=1.9; CI=1.3-2.6, P = 0.00) and woman’s occupation; housewife (OR=4.3; CI=2.5-7.2; P=0.00) were associated with the total unmet need. Conclusions Unmet need for family planning in Eastern Sudan was significantly higher among women with less than secondary education. Also; it is influenced by couple’s educational status and woman’s occupation. The results of this study necessitate the need for the programme managers to take into account the concept of reproductive health education.

2013-01-01

302

A review of analytical techniques for determination of Sudan I-IV dyes in food matrixes.  

PubMed

Sudan dyes are a family of lipophilic azo dyes, extensively used in industrial and scientific applications but banned for use as food colorants due to their carcinogenicity. Due to the continuing illicit use of Sudan dyes as food colorants their determination in different food matrices--especially in different chilli and tomato sauces and related products--has during the recent years received increasing attention all over the world. This paper critically reviews the published determination methods of Sudan I-IV dyes. LC-UV-vis and LC-MS are the dominating methods for analysis of Sudan I-IV dyes. Sudan dyes are usually found in food at mg kg(-1) levels at which it may be necessary to use a preconcentration step in order to attain the desired detection limits. Liquid-solid extraction is the dominating sample preparation procedure. In recent years it has been supplemented by ultrasonic-assisted extraction and pressurized liquid extraction. Various solid phase extraction types have been used for sample cleanup. The large majority of works use conventional C18 columns and conventional LC eluents. Traditionally the UV-vis absorbance detection has been the most frequently used. In the recent years MS detection is applied more and more often as it offers more reliable identification possibilities. PMID:20299022

Rebane, Riin; Leito, Ivo; Yurchenko, Sergei; Herodes, Koit

2010-04-23

303

Further studies on bluetongue and bluetongue-related orbiviruses in the Sudan.  

PubMed Central

The seasonal incidence of bluetongue virus (BTV) in Central Sudan is related primarily to fluctuations in the prevalence of the vector, Culicoides imicola. Population densities of this midge begin to rise with the onset of precipitation and peak during October, before falling sharply at the end of the rainy season in November. These are also the months of BTV transmission. Populations of C. schultzei, the commonest midge in Central Sudan, are also related to the rainy season but this species does not seem to be involved with BTV transmission. BTV serotype 2 was isolated from C. imicola confirming the status of this midge as a known vector but a second isolate of the same serotype was made from a mixed pool of Culicoides not including C. imicola. This suggests that BTV transmission in the Sudan may involve more than one species of Culicoides. Epizootic haemorrhagic disease virus (EHDV) serotype 4 and a palyam virus were isolated from C. schultzei which indicates that this species may be involved in the transmission of BT-related viruses. Seven further virus isolates from sentinel calves at Shambat (Khartoum) confirmed the presence of BTV serotypes 1, 4 and 16, and an untyped EHDV (designated 318) in the Sudan. All of the viruses isolated and identified during the course of this work are recorded from the Sudan for the first time. Images Fig. 3

Mohammed, M. E.; Mellor, P. S.

1990-01-01

304

Oral health status of 12-year-old school children in Khartoum state, the Sudan; a school-based survey  

Microsoft Academic Search

BACKGROUND: Few studies have investigated the prevalence of dental caries among school children in the past decades in Sudan rendering it difficult to understand the status and pattern of oral health. METHODS: A school-based survey was conducted using stratified random cluster sampling in Khartoum state, Sudan. Data was collected through interviews and clinical examination by a single examiner. DMFT was

Nazik Mostafa Nurelhuda; Tordis Agnete Trovik; Raouf Wahab Ali; Mutaz Faisal Ahmed

2009-01-01

305

76 FR 63635 - Extension of the Designation of Sudan for Temporary Protected Status and Automatic Extension of...  

Federal Register 2010, 2011, 2012, 2013

...demarcation of the border, the citizenship status of displaced persons, and the sharing of vital natural resources, such as Nile River water and oil reserves in South Sudan. The failure to formally demobilize the 180,000 soldiers from both Sudan...

2011-10-13

306

Development and validation of a confirmatory HPLC method for simultaneous determination of Sudan dyes in animal tissues and eggs.  

PubMed

A simple and sensitive high-performance liquid chromatography (HPLC) analytical method for the simultaneous determination of six Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B, Sudan IV) in animal tissues and eggs was developed. Samples were extracted with acetonitrile followed by a cleanup using a C(18) solid-phase extraction column. Chromatographic separation was achieved on a Zorbax SB-C(18) column under gradient conditions. The analytes were detected at 510 nm by HPLC with diode array detection. Specificity, decision limit (CCalpha), detection capacity (CCbeta), accuracy, and precision were determined during validation process. Recoveries for six Sudan dyes from three animal tissues and eggs were 77.2-98.0% with excellent relative standard deviations. CCalpha and CCbeta were in the range of 7.7-9.0 microg/kg and 9.1-10.3 microg/kg, respectively. The limits of quantitations were between 12.8 microg/kg and 15.0 microg/kg. PMID:20056039

Wu, Yin-Liang; Li, Cun; Xia, Xi; Liu, Yong-Jun; Shen, Jian-Zhong

2010-01-01

307

Magnetic solid-phase extraction and ultrafast liquid chromatographic detection of Sudan dyes in red wines, juices, and mature vinegars.  

PubMed

A nanocomposite of polystyrene-coated magnetic nanoparticles was successfully synthesized and employed as adsorbent for magnetic solid-phase extraction of four Sudan dyes (I, II III, and IV) in red wines, juices, and mature vinegars. The prepared magnetic nanoparticles with highly hydrophobic properties have excellent adsorption capacity for these lipophilic Sudan dyes. Extraction conditions were optimized. Experimental results showed that the recoveries of the four Sudan dyes were very satisfactory when 70 mg of polystyrene-coated magnetic nanoparticles were used and the extraction could be completed within 20 min. It was proved that these magnetic nanoparticles can be reused after an easy washing process. By coupling the magnetic solid-phase extraction with ultrafast liquid chromatography-ultraviolet spectrometry, a rapid, green, effective, and sensitive method for the determination of Sudan dyes was developed. The LOD for Sudan I, Sudan II, Sudan III, and Sudan IV were 0.0039, 0.0063, 0.0057, and 0.017 ng/mL, respectively. Recoveries obtained by analyzing spiked water samples at three concentration levels (0.1, 1.0, and 10.0 ng/mL) were between 76.3 and 96.6%. The intra- and interday RSDs for the analytes were lower than 9.6%. PMID:23184374

Yu, Xi; Sun, Ying; Jiang, Chun-Zhu; Gao, Yan; Wang, Yuan-Peng; Zhang, Han-Qi; Song, Da-Qian

2012-12-01

308

First record of the family Dromaeosauridae (Dinosauria: Theropoda) in the Cretaceous of Gondwana (Wadi Milk Formation, northern Sudan)  

Microsoft Academic Search

\\u000a Kurzfassung  Die cenomane Wadi Milk Formation des Sudan lieferte eine reiche kontinentale Wirbeltierfauna. Neben Fragmenten von großen\\u000a Theropoden verweisen disartikulierte Fußphalangen-Elemente und ein Zahn auf die Existenz von dromaeosauriden Theropoden in\\u000a der Oberkreide des Sudan; damit ist diese Theropodenfamilie zum ersten Mal auf den Gondwana-Kontinenten nachgewiesen.

Oliver W. M. Rauhut; Christa Werner

1995-01-01

309

'Little Ice Age' glacier variations in Jotunheimen, southern Norway: a study in regionallycontrolledlichenometricdatingof recessional moraines with implications for climate and lichen growth rates  

Microsoft Academic Search

A new approach to regional lichenometric dating is developed and applied to 'Little Ice Age' moraine-ridge sequences on 16 glacier forelands in Jotunheimen, southern Norway. Lichenometric-dating curves, based on the Rhizocarpon subgenus, are constructed independently for west, central and east Jotunheimen. Although there are differences between the subregions, a composite regional moraine chron- ology for Jotunheimen identifies 12 episodes of

John A. Matthews

310

Recent paleolimnology and paleoecology of a high-altitude lake in the Southern Central Andes (Lake Laja, Chile): Natural development versus anthropogenic impact, and implications for paleoclimate studies  

Microsoft Academic Search

High-altitude lakes in the Andes tend to be unaffected by anthropogenic influence. However, some of these lakes have been influenced by humans in the recent past. In this paper we explore the impact of a hydroelectrical power station on the limnology and the ecosystem in the high-altitude lake Laja in the southern central Andes of Chile over the last 50

A. Mueller; B. Scharf; S. Woelfl; R. Urrutia; H. Treutler; M. Pirrung; M. Grosjean; F. Cruces; A. Araneda; L. Torres; O. Parra; W. Geller

2004-01-01

311

Structure of Tendaho Graben and Manda Hararo Rift: Implications for the evolution of the southern Red Sea propagator in Central Afar  

Microsoft Academic Search

The Red Sea and Aden rifts (or propagators) meet in Afar. Here we use remote sensing and field analyses to define the geology and structure of the southern part of the Red Sea propagator in Central Afar. This consists of the NW-SE trending Tendaho Graben (TG) and the younger and active NW-SE trending Manda Hararo Rift (MHR), partly within TG.

V. Acocella; B. Abebe; T. Korme; F. Barberi

2008-01-01

312

Implications of bedform dimensions for the prediction of local scour in tidal inlets: a case study from the southern North Sea  

Microsoft Academic Search

The bedforms and the local scour at the base of a cylindrical pile were studied in a tidal inlet in the Wadden Sea, southern North Sea, using high-resolution multibeam bathymetry data from four surveys. The observed changes in scour and bedform dimensions were interpreted in terms of hydraulic forcings varying periodically at different time scales. It appears that bedform orientation

Riko Noormets; Verner B. Ernstsen; Alex Bartholomä; Burg W. Flemming; Dierk Hebbeln

2006-01-01

313

Correlates of condom use among males in North Sudan.  

PubMed

Objectives In sub-Saharan Africa countries, HIV infections are transmitted primary through heterosexual contact. Correct and consistent condom use has been promoted as a method to prevent sexually transmissible infections, including HIV. The aim of this study was to assess and determine the factors influencing condom use in Khartoum, Sudan. Materials and methods: Out of the 45 voluntary counselling and testing centres in Khartoum region, 10 centres were selected. A random sample of 804 respondents aged 20-40 years was selected. Stepwise multiple logistic regression analysis was used to investigate the predictors of condom use. Results: About 12% of respondents reported using condoms consistently, 41.5% used them sporadically and 46.3% were nonusers. Most of the participants had problems with condom use (81.9%) and friends were the main source of condoms (72%). Knowledge about AIDS transmission, knowing someone who is infected with or had died of AIDS, experiencing condom problems, type of sexual partners, purchase embarrassment and education were the main predictors of condom use. Conclusions: Condom use among the Sudanese is low. Strategies to promote condom use should focus on price support for condoms by the government, expanded private sector condom distribution and the integration of sex education in school curriculums or via frequent discussion on television. PMID:24560176

Mohamed, Badreldin A

2014-03-01

314

Estimation of malaria transmission intensity in Sennar state, central Sudan.  

PubMed

Understanding the behaviour of malaria vectors is crucial for planning mosquito control programmes. The aim of this study was to estimate the malaria transmission intensity in 2 different ecological zones in a highly endemic malaria area of Sennar state in central Sudan over the main transmission period. Species confirmation by PCR indicated that Anopheles arabiensis was the only malaria vector in the study area, with high anthropophilic behaviour (84.9% human-feeding). ELISA studies showed Plasmodium falciparum sporozoite rates rose from 1.8% to 4.5% and the average entomological inoculation rates rose from 2.4 to 4.2 infectious bites per person per night in September (the beginning) to November (the end) of the 3-month transmission season. The proportion of malaria-positive slides ranged from 50.1% to 57.0%. The proportion of human-blood positive mosquitoes was significantly higher in the irrigated area (El Booster) compared with the non-irrigated area (Rahal). PMID:23057388

Elmahdi, Z A; Nugud, A A; Elhassan, I M

2012-09-01

315

Aflatoxins in peanut butter in Khartoum State, Sudan.  

PubMed

Forty-three peanut butter samples from Khartoum State, Sudan, were analyzed for aflatoxins (AFs, AFB1?+?AFB2?+?AFG1?+?AFG2) using high performance liquid chromatography (HPLC) with fluorescence detection after extraction with methanol:water (8:1, v/v) and clean-up using chloroform. All samples were contaminated with AFs, with total AF levels ranging between 26.7 and 853 ?g/kg, and a mean total AF level of 287 ± 200.5 ?g/kg. The highest concentrations were found for AFB1, (28 positive samples, maximum 534 ?g/kg), while AFG1 was most frequently detected (43 positive samples, maximum 401 ?g/kg). AFB2 (42 positive samples, maximum 3.2 ?g/kg) and AFG2 (4 positive samples, maximum 30 ?g/kg) were also present in these samples. The mean AF contamination levels found in this study exceeded by far all international regulations concerning maximum levels for this group of toxins. From the data, it is concluded that the levels of AF contamination in peanut butter from the Kartoum area are quite alarming, and may pose serious health hazards to consumers. Therefore, an intervention strategy to manage AF in peanut butter is urgently needed. PMID:23605798

Elzupir, Amin Osman; Salih, Amar O A; Suliman, Suliman A; Adam, Ali A; Elhussein, Abdelrahim M

2011-08-01

316

Modelling of sedimentation processes inside Roseires Reservoir (Sudan)  

NASA Astrophysics Data System (ADS)

Roseires Reservoir, located on the Blue Nile River, in Sudan, is the first trap to the sediments coming from the upper catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir lost already more than one third of its storage capacity due to sedimentation in the last four decades. Appropriate management of the eroded area in the upper basin could mitigate this problem. In order to do that, the areas providing the highest sediment volumes to the river have to be identified, since they should have priority with respect to the application of erosion control practices. This requires studying the sedimentation record inside Roseires Reservoir, with the aim of identifying when and how much sediment from a certain area is deposited. The identification of deposition time is derived from soil stratification inside the reservoir. This requires expensive coring campaigns that need to be optimized. The most promising sampling coring areas were therefore selected beforehand by combining bathymetric data and the results of a depth-averaged morphodynamic model able to record vertical stratification in sediment deposits. The model allowed recognising the areas that are potentially neither subject to net erosion nor to bar migration during the life span of the reservoir. Verification of these results was carried out by analysing sediment stratification from the data collected in subsequent field campaign.

Omer, A. Y. A.; Ali, Y. S. A.; Roelvink, J. A.; Dastgheib, A.; Paron, P.; Crosato, A.

2014-03-01

317

Sources and composition of aerosol from Khartoum, Sudan  

NASA Astrophysics Data System (ADS)

Aerosol sampling was carried out during December 1989 in Khartoum, Sudan, using Nuclepore membrane filters. Twenty-four aerosol samples were collected and analysed by X-ray fluorescence (XRF) spectrometry and particle-induced X-ray emission (PIXE). In addition, individual particle analysis was also performed on 19 samples using electron probe X-ray microanalysis (EPXMA). Good agreement between XRF and PIXE results was obtained for most of the elements. Enrichment factor calculations indicated that soil dispersion is the dominant source for most elements in the aerosol. However, certain elements showed high enrichment factors indicating the presence of anthropogenic sources. From a comparison with available literature data it appeared that the enrichment factors for the enriched elements in the Khartoum aerosol are among the lowest recorded values for urban aerosol. Absolute principal components analysis (APCA) was performed on the data and confirmed the findings from the enrichment factor calculations, i.e. a dominant soil dispersion source and an anthropogenic source for some of the elements. Because of the very limited number of impotant aerosol sources, the data set was reporduced by the APCA model with a reasonable degree of success. Single particle analysis also showed that most of the particles were soil dust. These particles could further be differentiated into alumino-silicates, quartz and CaCO 3 particles. Some of the particles were found to originate from combustion sources. EPXMA gave clues to the process of formation for some of the particles from combustion sources.

Eltayeb, Mohamed A. H.; Xhoffer, Chris F.; Van Espen, Pierre J.; Van Grieken, RenéE.; Maenhaut, Willy

318

[Sudan and other illegal dyes--food adulteration].  

PubMed

As foodstuffs adulterated by illegal dyes, such as Sudan I, II, III IIV, para-Red, have appeared on the European Union market, the emergency measures to eliminate this problem have been taken. The illegal dyes are added to dried, ground chilli, curry, curcuma and to palm oil. These products are imported from countries outside the E.U. The adulteration concerns also ready to eat products which contain the ingredients mentioned above. Apart from the adulteration, the presence of illegal dyes in foodstuffs can be a threat to consumer's health. In 2003-2005 three Commission Decisions on emergency measures regarding some products which can contain illegal dyes were published. Since May 2003 to March 2006, 651 notifications on food adulteration by illegal dyes were sent to the RASFF system. As a result of the taken measures, the number of notifications have decreased. The possibility of food adulteration by illegal dyes different from the ones which are used now are considered. This is the reason why the continuation of food control and cooperation between official control authorities and food producers are necessary. PMID:17713194

Gajda, Joanna; Switka, Agnieszka; Ku?ma, Katarzyna; Jarecka, Jolanta

2006-01-01

319

Addressing malaria vector control challenges in South Sudan: proposed recommendations  

PubMed Central

Upon the signing of the Comprehensive Peace Agreement in 2005, the Republic of South Sudan (RSS) has faced a lot of challenges, such as a lack of infrastructure, human resources and an enormous burden of vector borne diseases including malaria. While a national malaria strategic plan 2006-2011 was developed, the vector control component has remained relatively weak. The strategy endorses the distribution of long-lasting insecticidal nets (LLINs) as the frontline intervention with other interventions recommended only when technical and institutional capacity is available. In 2006, a draft integrated vector management (IVM) strategic plan 2007–2012 was developed but never implemented, resulting in minimal coordination, implementation and coverage of malaria vector control tools including their inherent impact. To address this challenge, the vector control team of the National Malaria Control Programme (NMCP) is being strengthened. With the objective of building national capacity and technical collaboration for effective implementation of the IVM strategy, a national malaria vector control conference was held from 15-17th October 2012 in Juba. A range of NMCP partners, state ministries, acadaemia, private sector, national and international non-governmental organizations, including regional and global policymakers attended the meeting. The conference represented a major milestone and made recommendations revolving around the five key elements of the IVM approach. The meeting endorsed that vector control efforts in RSS be augmented with other interventions within the confines of the IVM strategy as a national approach, with strong adherence to its key elements.

2013-01-01

320

Cystic echinococcosis in Mundari tribe-members of South Sudan.  

PubMed

Many neglected tropical diseases, including the zoonotic disease cystic echinococcosis (hydatidosis), are endemic to East Africa. However, their geographical distribution is heterogenous and incompletely characterized. The aim of this study was to determine if Mundari pastoralists harbor endemic human hydatidosis. The survey was conducted in cattle camps randomly selected from accessible sites provided by officials in Terekeka, South Sudan. Following informed consent, a questionnaire collected demographic data and hydatid exposure risk. A systematic sonographic abdominal exam was performed using General Electric's LOGIQ Book XP with a 3C-RS 2-5 MHz curvilinear transducer. Six hundred and ten individuals were screened from 13 camps. Four infections were identified, all in women. The prevalence of abdominal hydatid disease in the Mundari tribe-members in cattle camps was 0·7% and all individuals reporting at least one high-risk exposure to hydatid disease. Cystic echinococcosis is endemic among Mundari pastoralists; however, it would appear to be less endemic than in neighboring tribes. PMID:24139620

Stewart, Barclay T; Jacob, Joseph; Finn, Timothy; Lado, Mounir; Napoleon, Robert; Brooker, Simon; Sidhu, Paul S; Kolaczinski, Jan

2013-09-01

321

Respiratory symptoms and occupational bronchitis in chromite ore miners, Sudan.  

PubMed

Prevalence of respiratory symptoms and chronic bronchitis was determined in a group of 122 subjects (77 exposed miners, 18 partially exposed, 27 controls) working at chromite ore mines in Sudan. The mean ages (+/- s.d.) of the three groups were 36.4 (+/- 7.8), 35.2 (+/- 6.8) and 34.6 (+/- 7.5) years respectively. Methods included a respiratory symptoms questionnaire based on the British Medical Research Council (MRC 1976) questionnaire on respiratory symptoms, determination of FEV1, FVC and FEV1/FVC%. The majority (66%) of the exposed subjects were non-smokers (NS) and 20 (77%) of the 'ever-smokers' (current and ex-smokers) were smokers of less than 15 cigarettes day-1. Respiratory symptoms (cough, phlegm, dyspnoea) were more frequent among the miners and so was chronic bronchitis. The prevalence of the latter was 26% among the miners compared to 11% and 7% among the partially exposed and the controls respectively. These differences could not be accounted for by cigarette smoking. Sixty-five per cent of the miners diagnosed as having asthma, chronic bronchitis or both were non-smokers. Although the values for the FEV1/FVC% remained normal or near the lower limits of the normal range, the mean value was significantly lower among the miners. It was concluded that the mine dust was the prime cause of the respiratory symptoms and chronic bronchitis among the miners. PMID:3795322

Ballal, S G

1986-10-01

322

Direct method for determination of Sudan I in FD&C Yellow No. 6 and D&C Orange No. 4 by reversed-phase liquid chromatography.  

PubMed

A reversed-phase liquid chromatographic method was developed to determine parts-per-million and higher levels of Sudan 1, 1-(phenylazo)-2-naphthalenol, in the disulfo monoazo color additive FD&C Yellow No. 6 and in a related monosulfo monoazo color additive, D&C Orange No. 4. Sudan I, the corresponding unsulfonated monoazo dye, is a known impurity in these color additives. The color additives are dissolved in water and methanol, and the filtered solutions are directly chromatographed, without extraction or concentration, by using gradient elution at 0.25 mL/min. Calibrations from peak areas at 485 nm were linear. At a 99% confidence level, the limits of determination were 0.008 microg Sudan I/mL (0.4 ppm) in FD&C Yellow No. 6 and 0.011 microg Sudan I/mL (0.00011%) in D&C Orange No. 4. The confidence intervals were 0.202 +/- 0.002 microg Sudan I/mL (10.1 +/- 0.1 ppm) near the specification level for Sudan I in FD&C Yellow No. 6 and 20.0 +/- 0.2 microg Sudan I/mL (0.200 +/- 0.002%) near the highest concentration of Sudan I found in D&C Orange No. 4. A survey was conducted to determine Sudan I in 28 samples of FD&C Yellow No. 6 from 17 international manufacturers over 3 years, and in a pharmacology-tested sample. These samples were found to contain undetected levels (16 samples), 0.5-9.7 ppm Sudan I (0.01-0.194 microg Sudan I/mL in analyzed solutions; 11 samples including the pharmacology sample), and > or =10 ppm Sudan I (> or = 0.2 microg Sudan I/mL; 2 samples). Analyses of 21 samples of D&C Orange No. 4 from 8 international manufacturers over 4 years found Sudan I at undetected levels (8 samples), 0.0005 to < 0.005% Sudan I (0.05 to < 0.5 microg Sudan I/mL in analyzed solutions; 3 samples, including a pharmacology batch), 0.005 to <0.05% Sudan I (0.5 to <5 microg Sudan I/mL; 9 samples), and 0.18% Sudan I (18 microg Sudan I/mL; 1 sample). PMID:17955981

Petigara, Bhakti R; Scher, Alan L

2007-01-01

323

A new genus for a rare African vespertilionid bat: insights from South Sudan  

PubMed Central

Abstract A new genus is proposed for the strikingly patterned African vespertilionid “Glauconycteris” superba Hayman, 1939 on the basis of cranial and external morphological comparisons. A review of the attributes of a newly collected specimen from South Sudan (a new country record) and other museum specimens of “Glauconycteris” superba suggests that “Glauconycteris” superba is markedly distinct ecomorphologically from other species classified in Glauconycteris and is likely the sister taxon to Glauconycteris sensu stricto. The recent capture of this rarely collected but widespread bat highlights the need for continued research in tropical sub-Saharan Africa and in particular, for more work in western South Sudan, which has received very little scientific attention. New country records for Glauconycteris cf. poensis (South Sudan) and Glauconycteris curryae (Gabon) are also reported.

Reeder, DeeAnn M.; Helgen, Kristofer M.; Vodzak, Megan E.; Lunde, Darrin P.; Ejotre, Imran

2013-01-01

324

Simultaneous determination of Sudan dyes and carotenoids in red pepper and tomato products by HPLC.  

PubMed

To simultaneously detect Sudan dyes and carotenoids in red pepper and tomato products, high-performance liquid chromatography (HPLC) methods with photodiode-array detection are developed and validated. The methods include the use of end-capped and nonend-capped adsorbents with a gradient elution system starting with water containing methanol. Water content of 9% in the starting mobile phase is found to be necessary to ensure sufficient separation of Sudan dyes and to avoid overlapping or interference with the carotenoids of considerable content. The data of the validation reveal the accuracy and precision of the developed methods. A limit of Sudan dyes detection of 1-5 microg/g in red pepper or tomato sauce could be approached. The methods provide excellent separation of the carotenoids from the unsaponified extracts of red pepper and the tomato products. PMID:16212791

Daood, Hussein G; Biacs, Péter A

2005-10-01

325

[Rapid determination of Sudan dyes adulterated in natural paprika red by FTIR].  

PubMed

How to rapidly determine synthesized pigments or dyes adulterated in natural pigments is a difficult problem for food analysts. Natural paprika red is widely used in foods because of its coloration and pharmaceutical effect, but it is sometimes adulterated with Sudan dyes for its poor stability under light or heat treatment. In the present paper, the macro-fingerprint characteristic of infrared spectroscopy was utilized to identify Sudan dyes adulterated in paprika red. The strong peaks at 1 621, 1 500 and 751 cm(-1) in FTIR spectra and at the fingerprint region of 753, 684 and 496 cm(-1) in the secondary deriative FTIR spectra were remarkable characteristics for Sudan dyes adulterated in paprika red, of which the limit of determination was about 1%. PMID:22715761

Zhang, Wei-wei; Liu, Ling-ling; Wu, Yan-wen; Ouyang, Jie; Sun, Su-qin

2012-04-01

326

Seasonal variation of carbon fluxes in a sparse savanna in semi arid Sudan  

PubMed Central

Background Large spatial, seasonal and annual variability of major drivers of the carbon cycle (precipitation, temperature, fire regime and nutrient availability) are common in the Sahel region. This causes large variability in net ecosystem exchange and in vegetation productivity, the subsistence basis for a major part of the rural population in Sahel. This study compares the 2005 dry and wet season fluxes of CO2 for a grass land/sparse savanna site in semi arid Sudan and relates these fluxes to water availability and incoming photosynthetic photon flux density (PPFD). Data from this site could complement the current sparse observation network in Africa, a continent where climatic change could significantly impact the future and which constitute a weak link in our understanding of the global carbon cycle. Results The dry season (represented by Julian day 35–46, February 2005) was characterized by low soil moisture availability, low evapotranspiration and a high vapor pressure deficit. The mean daily NEE (net ecosystem exchange, Eq. 1) was -14.7 mmol d-1 for the 12 day period (negative numbers denote sinks, i.e. flux from the atmosphere to the biosphere). The water use efficiency (WUE) was 1.6 mmol CO2 mol H2O-1 and the light use efficiency (LUE) was 0.95 mmol CO2 mol PPFD-1. Photosynthesis is a weak, but linear function of PPFD. The wet season (represented by Julian day 266–273, September 2005) was, compared to the dry season, characterized by slightly higher soil moisture availability, higher evapotranspiration and a slightly lower vapor pressure deficit. The mean daily NEE was -152 mmol d-1 for the 8 day period. The WUE was lower, 0.97 mmol CO2 mol H2O-1 and the LUE was higher, 7.2 ?mol CO2 mmol PPFD-1 during the wet season compared to the dry season. During the wet season photosynthesis increases with PPFD to about 1600 ?mol m-2s-1 and then levels off. Conclusion Based on data collected during two short periods, the studied ecosystem was a sink of carbon both during the dry and wet season 2005. The small sink during the dry season is surprising and similar dry season sinks have not to our knowledge been reported from other similar savanna ecosystems and could have potential management implications for agroforestry. A strong response of NEE versus small changes in plant available soil water content was found. Collection and analysis of flux data for several consecutive years including variations in precipitation, available soil moisture and labile soil carbon are needed for understanding the year to year variation of the carbon budget of this grass land/sparse savanna site in semi arid Sudan.

Ardo, Jonas; Molder, Meelis; El-Tahir, Bashir Awad; Elkhidir, Hatim Abdalla Mohammed

2008-01-01

327

Effects of Orange II and Sudan III azo dyes and their metabolites on Staphylococcus aureus.  

PubMed

Azo dyes are widely used in the plastic, paper, cosmetics, food, and pharmaceutical industries. Some metabolites of these dyes are potentially genotoxic. The toxic effects of azo dyes and their potential reduction metabolites on Staphylococcus aureus ATCC BAA 1556 were studied. When the cultures were incubated with 6, 18, and 36 ?g/ml of Orange II and Sudan III for 48 h, 76.3, 68.5, and 61.7% of Orange II and 97.8, 93.9, and 75.8% of Sudan III were reduced by the bacterium, respectively. In the presence of 36 ?g/ml Sudan III, the cell viability of the bacterium decreased to 61.9% after 48 h of incubation, whereas the cell viability of the control culture without the dye was 71.5%. Moreover, the optical density of the bacterial cultures at 10 h decreased from 0.74 to 0.55, indicating that Sudan III is able to inhibit growth of the bacterium. However, Orange II had no significant effects on either cell growth or cell viability of the bacterium at the tested concentrations. 1-Amino-2-naphthol, a metabolite common to Orange II and Sudan III, was capable of inhibiting cell growth of the bacterium at 1 ?g/ml and completely stopped bacterial cell growth at 24-48 ?g/ml. On the other hand, the other metabolites of Orange II and Sudan III, namely sulfanilic acid, p-phenylenediamine, and aniline, showed no significant effects on cell growth. p-Phenylenediamine exhibited a synergistic effect with 1-amino-2-naphthol on cell growth inhibition. All of the dye metabolites had no significant effects on cell viability of the bacterium. PMID:21451978

Pan, Hongmiao; Feng, Jinhui; Cerniglia, Carl E; Chen, Huizhong

2011-10-01

328

Using apatite (U-Th)/He thermochronometry to resolve regional unroofing patterns across the interior of the southern African Plateau and implications for mantle dynamics  

NASA Astrophysics Data System (ADS)

The southern African Plateau is a long wavelength physiographic feature characterized by elevated Archean and Proterozoic cratonic lithosphere surrounded by a horseshoe shaped "Great Escarpment" which drops to the coastal plane. The average elevation of the plateau interior is ~1 km, ~0.5 km higher than average cratons. Unlike other major continental plateaus, southern Africa is surrounded by divergent margins which formed during the Jurassic breakup of Gondwana. The mechanisms for plateau uplift are intensely debated and include mantle drivers such as shallow convection or dynamic topography related to the southern African superplume. Constraining the timing and patterns of uplift can help to differentiate these competing explanations for the high topography. Thermochronological studies can yield critical information regarding unroofing histories to help decipher the timing and causes of plateau elevation gain. Previous studies using apatite fission-track (AFT) thermochronology mostly focused on transects across southern portions of the Great Escarpment. However, despite its importance for resolving large-scale unroofing patterns, there is limited thermochronological information from the plateau interior. This is in part because the temperature sensitivity of the AFT system may be somewhat higher than that required to tightly resolve the lower magnitudes of unroofing in the plateau interior relative to the coastal plain. The (U-Th)/He system in apatite (AHe) is particularly well-suited to this problem because its sensitivity to temperatures as low as ~30°C allows unroofing events in the upper 1-2 km of crust to be detected. Here we present the first AHe dataset from a broad swath across the interior of the plateau from northern South Africa and Botswana. New AHe data for eight Proterozoic diabase samples yield Cretaceous dates that display an interesting bimodal distribution of data. These results suggest at least 1.5 km of unroofing across this portion of the plateau interior since Cretaceous time. The only published AHe data for southern Africa (Flowers and Schoene 2009) comes from across the Great Escarpment in the Barberton region of South Africa and Swaziland. Those results are also Cretaceous with dates clustering ~100 Ma. Our new data, when combined with the previously published results, complete a large scale, ~900 km long, transect of AHe data from the coastal plain across the Great Escarpment well into the interior of the plateau. This full dataset suggests an intriguing spatial variability in dates, and shows the promise of using AHe data to decipher unroofing patterns across the continent to help better understand the mantle processes responsible for the rise of the southern African Plateau.

Stanley, J. R.; Flowers, R. M.

2011-12-01

329

Geochemistry, Pb?Pb single zircon ages and Nd?Sr isotope composition of Precambrian rocks from southern and eastern Ethiopia: implications for crustal evolution in East Africa  

NASA Astrophysics Data System (ADS)

Geochemical and isotope data for granitoid rocks from southern and eastern Ethiopia delineate the presumed margin of the Pan-African juvenile terrain of the Arabian-Nubian Shield against an older crustal segment of unknown origin extending from eastern Ethiopia to northern Somalia. Granitoids from southern Ethiopia have higher Na 2O and {Na20 }/{K2O} and lower Cr and Ni than granitoids with comparable SiO 2 values from eastern Ethiopia. In southern Ethiopia three periods of magmatism are identified on the basis on single zircon {207Pb}/{206Pb} evaporation ages, namely at ˜850, ˜750-700 and ˜650-550 Ma, and these correlate well with events documented from other parts of Ethiopia and the Arabian-Nubian Shield. The initial ?Nd(700 Ma) and ?sr(700 Ma) values range from -1.2 to +3.2 and from -13.4 to + 3.7, respectively, which precludes any significant contribution from much older continental crust in the generation of these rocks. Neodymium mean crustal residence ages, based on a depleted mantle model, range from 0.96 to 1.26 Ga. These data support the interpretation that southern Ethiopia constitutes part of the Arabian-Nubian Shield. In contrast, granitoids from eastern Ethiopia show geochemical features of S-type granites. In eastern Ethiopia Pal aeo-Neoproterozoic zircon ages (781-2489 Ma) are found. Initial ?Nd(700 Ma) and ?sr(700 Ma) values range from-4.3 to -18.3 and + 33.3 to + 99.8, respectively. Neodymium mean crustal residence ages range from 1.62 to 2.88 Ga. These data, in comparison to the western and southern parts of Ethiopia, are indicative of considerable reworking of pre-Pan-African crust. Variations in age, Sr?Nd isotope ratios and chemistry of the granitoids on a regional scale also suggest the existence of two separate basement terrains between southern and eastern Ethiopia, which may be separated by a tectonic line now concealed by Phanerozoic rocks. This tectonic line may represent a major tectonic boundary between the juvenile Arabian-Nubian Shield in the west and a pre-Pan-African gneissic terrain to the east, thus delineating the eastern margin of the Arabian-Nubian Shield.

Teklay, M.; Kröner, A.; Mezger, K.; Oberhänsli, R.

1998-02-01

330

STS-56 freeflying SPARTAN-201 backdropped over the Red Sea coast of Sudan  

NASA Technical Reports Server (NTRS)

During STS-56, the Shuttle Pointed Autonomous Research Tool for Astronomy 201 (SPARTAN-201), a freeflying payload, was captured on 70mm film as it drifts over the Red Sea coast of Sudan. SPARTAN-201 was photographed by the crewmembers aboard Discovery, Orbiter Vehicle (OV) 103. On the mission's third day, crewmembers used the remote manipulator system (RMS) to lift the satellite from its support structure in OV-103's payload bay (PLB) and release it into space. SPARTAN-201 was later recaptured by OV-103's RMS and returned to Earth with the astronaut crew. The cape structure in the background is Ras abu Shagara, north of Port Sudan.

1993-01-01

331

Metabolic influences for mutation induction curves after exposure to Sudan-1 and para red.  

PubMed

Sudan-1 and para red are industrial dyes that have been illegally added to some foodstuffs, leading to withdrawal of the adulterated products throughout the UK since 2003. This resulted in international concern that arose because Sudan-1 is classified by International Agency for Research on Cancer as a Category 3 carcinogen. However, little is known about the dose response of this chemical at low, more biologically relevant, doses. The study therefore aimed to characterize the dose response for gene mutation and chromosomal damage induced by two azo dyes, namely Sudan-1 and para red. Gene mutations were analysed using the hypoxanthine phosphoribosyltransferase forward mutation assay and chromosomal damage was measured using the cytokinesis-blocked micronucleus assay. Two cell lines were used in these investigations. These were the AHH-1 cell line, which inducibly expresses CYP1A1, and the MCL-5 cell line derived from a subpopulation of AHH-1 cells that expresses a particularly high level of CYP1A1 activity. The MCL-5 cell line has also been transfected with two plasmids that stably express CYP1A2, CYP2A6 and CYP3A4 and all four of these CYP enzymes are known to metabolically activate Sudan-1. AHH-1 cells were used to investigate the dose response of the azo dyes, and MCL-5 cells were used to see if the dose response changed with increased metabolism. Sudan-1 induced a non-linear dose-response curve for gene mutation and chromosomal damage in AHH-1 cells. The genotoxic activity of Sudan-1 was greatly increased in MCL-5 cells. This indicated that the oxidation metabolites from Sudan-1 were both more mutagenic and more clastogenic than the parent compound. Para red also demonstrated a non-linear dose response for both gene mutation and chromosome damage in AHH-1 cells, and an increase in micronuclei induction was observed after increased oxidative metabolism in MCL-5 cells. Sudan-1 and para red are genotoxic chemicals with non-linear dose responses in AHH-1 but not in MCL-5 cells, and oxidative metabolism increases the genotoxic effect of both compounds. PMID:20197315

Johnson, George E; Quick, Emma L; Parry, Elizabeth M; Parry, James M

2010-07-01

332

Rates of Holocene chemical weathering, `Little Ice Age' glacial erosion and implications for Schmidt-hammer dating at a glacier—foreland boundary, Fåbergstølsbreen, southern Norway  

Microsoft Academic Search

Average rates of Holocene chemical weathering and `Little Ice Age' glacial erosion of bedrock are estimated across the glacier—foreland boundary of an outlet glacier of the Jostedalsbreen ice-cap, southern Norway. Estimates are derived from two types of evidence: (1) the heights of quartz veins above adjacent surfaces of granitic or granodioritic gneiss; and (2) Schmidt-hammer R-values of rock hardness. Average

Geraint Owen; John A. Matthews; Paul G. Albert

2007-01-01

333

Gravity anomalies, Quaternary vents, and Quaternary faults in the southern Cascade Range, Oregon and California: Implications for arc and backarc evolution  

USGS Publications Warehouse

Isostatic residual gravity anomalies in the southern Cascade Range of northern California and southern Oregon are spatially correlated with broad zones of Quaternary magmatism as reflected by the total volume of Quaternary volcanic products, the distribution of Quaternary vents, and the anomalously low teleseismic P wave velocities in the upper 30 km of crust. The orientation of Quaternary faults also appears to be related to gravity anomalies and volcanism in this area, trending generally north-south within the magmatic regions and northwest-southeast as they enter the neighboring amagmatic zones to the north and south. The relationship between gravity anomalies, vent density, and fault orientations may indicate in a broad sense the strength of the middle and upper crust. The southern Cascade Range occupies a transition zone where horizontal stress is transferred from the northwest-southeast dextral shear of the Walker Lane belt to the east-west extension characteristic of the Cascade arc in central Oregon. Faulting along north-south strikes in the volcanically active areas indicates the east-west extensional stresses in thermally weakened crust, whereas northwest faulting between the volcanically active areas reflects the northwest trending, right lateral shear strain of the Walker Lane belt. The segmentation of the arc reflected in Quaternary magmatism may be caused by differential extension behind crustal blocks of the forearc rotating clockwise with respect to North America. In this view the volcanic centers at Mount Shasta, Medicine Lake volcano, and Lassen Peak in northern California are situated along the southern parts of the trailing edges of two distinct segments of the forearc where additional extension is implied by their differential clockwise rotation. U.S. copyright. Published in 1997 by the American Geophysical Union.

Blakely, R. J.; Christiansen, R. L.; Guffanti, M.; Wells, R. E.; Donnelly-Nolan, J. M.; Patrick, Muffler, L. J.; Clynne, M. A.; Smith, J. G.

1997-01-01

334

Crustal thickness and affinity in the southern Beaufort Sea from old deep seismic reflection profiles and gravity modelling and implications for Canada Basin evolution  

NASA Astrophysics Data System (ADS)

The rifting and break-up of continental crust to form oceanic basins is a fundamental process in geodynamics that generates passive continental margins. While rifting itself is fairly extensively studied, the transition from continental extension through break-up into seafloor spreading is more poorly understood. In this study we focus on the southern Beaufort Sea where a propagating seafloor spreading centre ceased activity probably sometime in the Cretaceous. We have reinterpreteda series of deep seismic reflection profiles and modelled gravity data to elucidate the variations in crustal and mantle geometry in the marginal parts of the southern Beaufort Sea adjacent to that part of the Canada Basin considered to have formed as a result of seafloor spreading. We find that the sub-sedimentary crustal layer is very thin in parts of the Beaufort Sea margin and interpret this as representing hyperextended continental crust (overlying hyperextended continental lithosphere) rather than oceanic crust as has been proposed previously. We use this result in an extensional strain distribution analysis, which indicatesthat total crustal extension is evidently much higher than upper crustal extension alone.The subsidence analysis suggests that the lithospheric hyperextension occurred in front of the seafloor spreading domain at the same time that seafloor spreading was occurring and that the continental margin crust continued to extend even after the end of the seafloor spreading in the adjacent ocean basin, consistent with amodel of very weak lithosphere in the area of the southern Beaufort Sea shelf.

Li, L.; Stephenson, R.

2013-12-01

335

Petrogenesis of the Early Eocene adakitic rocks in the Napuri area, southern Lhasa: Partial melting of thickened lower crust during slab break-off and implications for crustal thickening in southern Tibet  

NASA Astrophysics Data System (ADS)

Cenozoic adakitic rocks in the Lhasa block (southern Tibet) have been widely used to trace the lateral extent of crustal thickening. However, their petrogenesis remains controversial. Here, we report geochronological and geochemical data for the Napuri intrusive rocks in the core area of the Quxu batholith, southern Lhasa. Zircon U–Pb dating suggests that they were generated at approximately 48 Ma. The studied samples show significant geochemical variations, manifested by the coexistence of three types of igneous rocks. Groups I and II rocks exhibit variable and high SiO2 (66.4–73.9 wt.%), high Al2O3 (14.0–17.4 wt.%), K2O (3.9–5.3 wt.%), Sr (273–718 ppm) and Sr/Y (18.3 to 81.3) values, and low Y (3.6 to 16 ppm), heavy rare earth element (REE) (e.g., Yb = 0.48 to 1.8 ppm), MgO (0.4–1.0 wt.%), Cr (2.9–7.4 ppm) and Ni (1.6–4.5 ppm) contents, which are similar to those of thickened lower crust-derived adakitic rocks. The Group I rocks show higher Sr/Y (77.5–81.3) ratios and lower total REE (55.5–63.2 ppm) contents with clearly positive Eu and Sr anomalies, whereas the Group II rocks have relatively lower Sr/Y (18.3–65.7) ratios and higher total REE (115–375 ppm) contents with negligible or slightly negative Eu and Sr anomalies. Group III rocks have the highest SiO2 (74.5–76.0 wt.%), Y (17.0–23.7 ppm) and Yb (2.91–3.30 ppm) contents, and the lowest Al2O3 (12.5–13.2 wt.%), Sr (81.3–141 ppm) and Sr/Y (4.8–5.9) values with distinctly negative Eu and Sr anomalies. Compared with the Jurassic–Cretaceous granitoids in southern Lhasa, the relative enrichment in Sr–Nd–Hf isotopic compositions ((87Sr/86Sr)i = 0.7049–0.7055, ?Nd(t) = ? 0.3 ± 0.7 and ?Hf(t)zircon = + 3.6 ± 11.4) for the Napuri intrusive rocks indicates that they likely contained Indian continental components. The Group I and Group II rocks most probably originated from thickened mafic lower crust (amphibolite eclogites or garnet amphibolites) with garnet + rutile ± plagioclase as residual minerals in the source at > 1.5 GPa, corresponding to depths of > 50 km, and Group III rocks were probably generated by fractional crystallization of plagioclase from the adakitic magmas. Taking into account the narrow linear nature of the Eocene magmatic belt and reported synchronous asthenosphere-derived basaltic rocks in southern Lhasa, we suggest that upwelling asthenosphere triggered by the break-off of subducted Neo-Tethyan slab probably provided the required thermal conditions for lower crustal melting. The identification of Indian continental components in the Napuri intrusive rocks probably indicates that the Asia–India collision had taken place prior to their emplacement. The dramatic changes in the (La/Yb)N ratios and ?Nd(t) and ?Hf(t) values of magmatic rocks in the Gangdese area at ca. 51–46 Ma indicate that the Cenozoic crustal thickening associated with the indentation of the Indian continent began in the Early Eocene (ca. 51–46 Ma) at the latest.

Ma, Lin; Wang, Bao-Di; Jiang, Zi-Qi; Wang, Qiang; Li, Zheng-Xiang; Wyman, Derek A.; Zhao, Shou-Ren; Yang, Jin-Hui; Gou, Guo-Ning; Guo, Hai-Feng

2014-05-01

336

Ebola haemorrhagic fever in Sudan, 1976. Report of a WHO/International Study Team.  

PubMed

A large outbreak of haemorrhagic fever (subsequently named Ebola haemorrhagic fever) occurred in southern Sudan between June and November 1976. There was a total of 284 cases; 67 in the source town of Nzara, 213 in Maridi, 3 in Tembura, and 1 in Juba. The outbreak in Nzara appears to have originated in the workers of a cotton factory. The disease in Maridi was amplified by transmission in a large, active hospital. Transmission of the disease required close contact with an acute case and was usually associated with the act of nursing a patient. The incubation period was between 7 and 14 days. Although the link was not well established, it appears that Nzara could have been the source of infection for a similar outbreak in the Bumba Zone of Zaire.In this outbreak Ebola haemorrhagic fever was a unique clinical disease with a high mortality rate (53% overall) and a prolonged recovery period in those who survived. Beginning with an influenza-like syndrome, including fever, headache, and joint and muscle pains, the disease soon caused diarrhoea (81%), vomiting (59%), chest pain (83%), pain and dryness of the throat (63%), and rash (52%). Haemorrhagic manifestations were common (71%), being present in half of the recovered cases and in almost all the fatal cases.Two post mortems were carried out on patients in November 1976. The histopathological findings resembled those of an acute viral infection and although the features were characteristic they were not exclusively diagnostic. They closely resembled the features described in Marburg virus infection, with focal eosinophilic necrosis in the liver and destruction of lymphocytes and their replacement by plasma cells. One case had evidence of renal tubular necrosis.Two strains of Ebola virus were isolated from acute phase sera collected from acutely ill patients in Maridi hospital during the investigation in November 1976. Antibodies to Ebola virus were detected by immunofluorescence in 42 of 48 patients in Maridi who had been diagnosed clinically, but in only 6 of 31 patients in Nzara. The possibility of the indirect immunofluorescent test not being sufficiently sensitive is discussed.Of Maridi case contacts, in hospital and in the local community, 19% had antibodies. Very few of them gave any history of illness, indicating that Ebola virus can cause mild or even subclinical infections. Of the cloth room workers in the Nzara cotton factory, 37% appeared to have been infected, suggesting that the factory may have been the prime source of infection. PMID:307455

1978-01-01

337

Prioritizing maternal and child health in independent South Sudan.  

PubMed

With its independence secured on 9th July 2011, the Republic of South Sudan faces a daunting task to improve public health and primary care in one of the poorest countries in the world. Very high maternal and child mortality rates must be a major concern for the new national government and for the many international agencies working in the country. Poor maternal health outcomes are primarily due to poor prenatal, delivery and post natal care services in health facilities, coupled with low literacy, widespread poverty, and poor nutrition among the general population. Child mortality is the result of widespread malnutrition, pneumonia, malaria, vaccine preventable diseases and diarrheal diseases. National responses to HIV and AIDS with international assistance have been encouraging with relatively low rates of infection. This paper explores barriers and identifies opportunities available to work toward achieving the targets for Millennium Development Goals (MDGs) 5 and 4 to reduce maternal mortality from its current rate of 2,054 deaths per 100,000 live births, and child mortality (currently 135 deaths per 1,000 live births) respectively in the new nation. National and international organizations have a social responsibility to mobilize efforts to focus on maternal, child health and nutrition issues targeting the worst affected regions for improving access to primary care and obstetrical services. Initiatives are needed to build up community access to primary care with a well supervised community health workers program, as well as training mid level management capacity with higher levels of funding from national and international sources to promote public health than current in the new republic. PMID:21959924

Rai, Rajesh Kumar; Ramadhan, Ally Ahmed; Tulchinsky, Theodore Herzl

2012-08-01

338

Diabetic heel ulcer in the Sudan: determinants of outcome.  

PubMed

Heel ulceration, on average, costs 1.5 times more than metatarsal ulceration. The aim of this study was to analyze the determinant factors of healing in diabetic patients with heel ulcers and the late outcomes at Jabir Abu Eliz Diabetic Centre Khartoum, Khartoum, Sudan. Data were collected prospectively for 96 of 100 diabetic patients presenting with heel ulcers at the Jabir Abu Eliz Diabetic Centre Khartoum from May 2003 to January 2005. Late outcome was assessed 3 years later (February 2008). Heeling was achieved in one half of the patients (n = 48). In the remaining 48 patients, 22 ended with major lower extremity amputation and 22 were still receiving wound care. A total of 8 patients died, 4 in each group, the healed and unhealed. The most significant determinants of healing using a logistic multivariate regression model, 95% confidence intervals, and odds ratios included a shorter duration of diabetes (p < .009), adequate lower limb perfusion (p < .043), and a superficial foot ulcer (p < .012). Three years later, of the 88 patients who could be traced, 78 were alive and 59 had healed ulcers (7 had died of unrelated causes and 3 of diabetic-related complications), and no additional lower extremity amputation was recorded. Mortality in the series was 18 patients, of whom 14 had undergone a previous lower extremity amputation. Superficial heel ulcers in diabetic patients with a short history of diabetes and with good limb circulation are more likely to heal within an average duration of 25 weeks. At 3 years of follow-up, 75% showed a favorable outcome for ulcer healing, and 22 patients underwent lower extremity amputation (25%), of whom 14 were dead within 3 years. PMID:22078157

Bakheit, Haseeb E; Mohamed, Mohamed F; Mahadi, Seif ElDin I; Widatalla, Abu Bakr H; Shawer, Mohamed A; Khamis, Amar H; Ahmed, Mohamed E

2012-01-01

339

Bacteriological quality of drinking water in Nyala, South Darfur, Sudan.  

PubMed

The objective of this study was to determine the bacterial contaminations in drinking water in Nyala city, South Darfur, Sudan with special reference to the internally displaced people camps (IDPs). Two hundred and forty water samples from different sites and sources including bore holes, hand pumps, dug wells, water points, water reservoir and household storage containers were collected in 2009. The most probable number method was used to detect and count the total coliform, faecal coliform and faecal enterococci. Results revealed that the three indicators bacteria were abundant in all sources except water points. Percentages of the three indicators bacteria count above the permissible limits for drinking water in all samples were 46.4% total coliform, 45.2% faecal coliform and 25.4% faecal enterococci whereas the highest count of the indicators bacteria observed was 1,600 U/100 ml water. Enteric bacteria isolated were Escherichia coli (22.5%), Enterococcus faecalis (20.42%), Klebsiella (15.00%), Citrobacter (2.1%) and Enterobacter (3.33%). The highest contamination of water sources was observed in household storage containers (20%) followed by boreholes (11.25%), reservoirs (6.24%), hand pumps (5.42%) and dug wells (2.49%). Contamination varied from season to season with the highest level in autumn (18.33%) followed by winter (13.75%) and summer (13.32%), respectively. All sources of water in IDP camps except water points were contaminated. Data suggested the importance of greater attention for household contamination, environmental sanitation control and the raise of awareness about water contamination. PMID:20480392

Abdelrahman, Amira Ahmed; Eltahir, Yassir Mohammed

2011-04-01

340

Oral health of visually impaired schoolchildren in Khartoum State, Sudan  

PubMed Central

Background Although oral health care is a vital component of overall health, it remains one of the greatest unattended needs among the disabled. The aim of this study was to assess the oral health status and oral health-related quality of life (Child-OIDP in 11-13-year-old) of the visually challenged school attendants in Khartoum State, the Sudan. Methods A school-based survey was conducted in Al-Nour institute [boys (66.3%), boarders (35.9%), and children with partial visual impairment (PVI) (44.6%)]. Two calibrated dentists examined the participants (n=79) using DMFT/dmft, Simplified Oral Hygiene Index (OHI-S), dental care index, and traumatic dental injuries (TDI) index. Oral health related quality of life (C-OIDP) was administered to 82 schoolchildren. Results Caries experience was 46.8%. Mean DMFT (age?12, n=33) was 0.4 ± 0.7 (SiC 1.6), mean dmft (age<12, n=46) was 1.9 ±2.8 (SiC 3.4), mean OHIS 1.3 ± 0.9. Care Index was zero. One fifth of the children suffered TDI (19%). Almost one third (29%) of the 11–13 year old children reported an oral impact on their daily performances. A quarter of the schoolchildren (25.3%) required an urgent treatment need. Analysis showed that children with partial visual impairment (PVI) were 6.3 times (adjusted) more likely to be diagnosed with caries compared to children with complete visual impairment (CVI), and children with caries experience were 1.3 times (unadjusted) more likely to report an oral health related impact on quality of life. Conclusions Visually impaired schoolchildren are burdened with oral health problems, especially caries. Furthermore, the 11-13 year olds' burden with caries showed a significant impact on their quality of life.

2013-01-01

341

Determination of banned Sudan dyes in food samples by molecularly imprinted solid phase extraction-high performance liquid chromatography.  

PubMed

A method for molecularly imprinted SPE of banned Sudan azo-dyes from food samples was investigated. The molecularly imprinted polymer was obtained by suspension polymerization using 1-(4-chlorophenyl)azonaphthalen-2-ol as the mimic template. The molecular recognition properties of imprinted beads were evaluated for use as a SPE sorbent, in order to develop a selective extraction protocol for the Sudan class of dyes. The optimized extraction protocol resulted in a reliable molecularly imprinted SPE (MISPE) method suitable for HPLC analysis. It was selective for the main analyte, Sudan I, and the related azo-dyes Sudan II, III, IV, Sudan Red B, and Sudan Red 7B, while the permitted azo-dyes Allura Red AC, Neococcin, and Sunset Yellow FCF were not extracted. The method was tested for Sudan I, II, III, and IV in five different food samples (hot chilli pepper, hot chilli tomato sauce, sausage, tomato sauce, and hard boiled egg yolk) at three concentration levels (15, 100, and 300 microg/g). It demonstrated itself to be insensitive to the presence of different complex matrices, precise, accurate, and with good recovery rates (85-101%). The LOD and LOQ were satisfactory for most analytical determinations. PMID:19722173

Baggiani, Claudio; Anfossi, Laura; Baravalle, Patrizia; Giovannoli, Cristina; Giraudi, Gianfranco; Barolo, Claudia; Viscardi, Guido

2009-10-01

342

Late Holocene Environmental Change at Amara West: A New Kingdom Town on the Desert Nile in Northern Sudan  

NASA Astrophysics Data System (ADS)

Amara West is a well-preserved town of the late New Kingdom downstream of Sai Island in Northern Sudan. The town has being identified as the seat of the pharaonic administration of Kush (Upper Nubia) in the Ramesside Period (c. 1306-1070 BC). This region fell under Egyptian control after about 1500 BC. The modern Nile (flowing eastwards in this reach) lies to the south of the town and a well preserved palaeochannel lies immediately to the north. Following the Egypt Exploration Society excavations of 1938-39 and 1947-48, it was argued that the ancient town was once located upon an island in the Nile. Renewed archaeological excavations allied to geomorphological work on the ancient river environment are attempting to establish the nature of the local and regional landscape before, during, and after the occupation of the town. This paper presents new OSL and radiocarbon dates on the sedimentary fill from the palaeochannel system to establish when the channel system ceased to flow on a permanent basis. Micromorphological work on the sedimentary records within the town provide additional insights into the nature of the local environment during the period of occupation. We discuss the implications of the new palaeoenvironmental data for our understanding of Amara West and we set out the wider significance of these new geoarchaeological data.

Spencer, Neal; Woodward, Jamie; Macklin, Mark; Dalton, Matthew

2014-05-01

343

Concomitant Infection with Leishmania donovani and L. major in Single Ulcers of Cutaneous Leishmaniasis Patients from Sudan.  

PubMed

In Sudan human leishmaniasis occurs in different clinical forms, that is, visceral (VL), cutaneous (CL), mucocutaneous (ML), and post-kala-azar dermal leishmaniasis (PKDL). Clinical samples from 69 Sudanese patients with different clinical manifestations were subjected to a PCR targeting the cytochrome oxidase II (COII) gene for Leishmania species identification. Mixed infections were suspected due to multiple overlapping peaks presented in some sequences of the COII amplicons. Cloning these amplicons and alignment of sequences from randomly selected clones confirmed the presence of two different Leishmania species, L. donovani and L. major, in three out of five CL patients. Findings were further confirmed by cloning the ITS gene. Regarding other samples no significant genetic variations were found in patients with VL (62 patients), PKDL (one patient), or ML (one patient). The sequences clustered in a single homogeneous group within L. donovani genetic group, with the exception of one sequence clustering with L. infantum genetic group. Findings of this study open discussion on the synergetic/antagonistic interaction between divergent Leishmania species both in mammalian and vector hosts, their clinical implications with respect to parasite fitness and response to treatment, and the route of transmission with respect to vector distribution and or adaptation. PMID:24744788

Babiker, A M; Ravagnan, S; Fusaro, A; Hassan, M M; Bakheit, S M; Mukhtar, M M; Cattoli, G; Capelli, G

2014-01-01

344

Disability associated with exposure to traumatic events: results from a cross-sectional community survey in South Sudan  

PubMed Central

Background There is a general lack of knowledge regarding disability and especially factors that are associated with disability in low-income countries. We aimed to study the overall and gender-specific prevalence of disability, and the association between exposure to traumatic events and disability in a post-conflict setting. Methods We conducted a cross-sectional community based study of four Greater Bahr el Ghazal States, South Sudan (n = 1200). The Harvard Trauma Questionnaire (HTQ) was applied to investigate exposure to trauma events. Disability was measured using the Washington Group Short Measurement Set on Disability, which is an activity-based scale derived from the WHO’s International Classification of Disability, Functioning and Health. Results The estimated prevalence of disability (with severe difficulty) was 3.6% and 13.4% for disability with moderate difficulties. No gender differences were found in disability prevalence. Almost all participants reported exposure to at least one war-related traumatic event. The result of a hierarchical regression analysis showed that, for both men and women, exposure to traumatic events, older age and living in a polygamous marriage increased the likelihood of having a disability. Conclusions The finding of association between traumatic experience and disability underlines the precariousness of the human rights situation for individuals with disability in low-income countries. It also has possible implications for the construction of disability services and for the provision of health services to individuals exposed to traumatic events.

2013-01-01

345

The 2007 M5.4 Alum Rock, California, earthquake: Implications for future earthquakes on the central and southern Calaveras Fault  

NASA Astrophysics Data System (ADS)

The similarity of seismograms recorded by two seismic stations demonstrate that the 31 October 2007 moment magnitude M5.4 Alum Rock earthquake is a repeat of a 1955 ML5.5 earthquake. Both occurred on Oppenheimer et al.'s (1990) Zone V "stuck patch" on the central Calaveras fault, providing new support for their model of Calaveras fault earthquake activity. We suggest that Zone V fails only in a family of recurring M ˜ 5.4-5.5 earthquakes. The 1955 and 2007 earthquakes are the penultimate and ultimate Zone V events. Earthquakes in 1891 and 1864 are possible earlier Zone V events. The next Zone V event is not expected in the next few decades, assuming a time-dependent recurrence model: the mean forecast date is 2064 (2035-2104, 95% confidence range). We further suggest that Zones I, II, III, and IV fail in recurring M ˜ 5.1-5.3, M ˜ 5.6-5.8, M ˜ 6.1-6.3, and M ˜ 4.9-5.0 earthquakes, respectively. If our earthquake recurrence model is correct, the next Zone I event is overdue and could occur anytime, and M5-6 earthquakes should not occur on Zones II, III, and IV before 2014, 2012, and 2026, respectively. We cannot rule out the possibility that Zone VI, which lies at the southern end of the Mission Seismic Trend, where the southern Hayward and central Calaveras faults appear to connect at depth, fails aseismically or in large events on the southern Hayward fault, such as last occurred in 1868, or in large events on the adjoining northern Calaveras fault segment.

Oppenheimer, David H.; Bakun, William H.; Parsons, Tom; Simpson, Robert W.; Boatwright, John; Uhrhammer, Robert A.

2010-08-01

346

Paleocene-Eocene foreland basin evolution in the Himalaya of southern Tibet and Nepal: Implications for the age of initial India-Asia collision  

NASA Astrophysics Data System (ADS)

sedimentary rocks derived from the southern Lhasa terrane, sitting depositionally upon rocks of the northern Indian passive continental margin, provide an estimate of the age of initial contact between the continental parts of the Indian and Asian plates. We report sedimentological, sedimentary petrological, and geochronological data from Upper Cretaceous-Paleocene strata in the Sangdanlin section, located along the southern flank of the Indus-Yarlung suture zone in southern Tibet. This is probably the most proximal, and therefore the oldest, record of the India-Asia collision. These strata were deposited by high-density turbidity currents (or concentrated density flows) and suspension settling of pelagic biogenic debris in a deep-marine setting. An abrupt change from quartz-arenitic to feldspatholithic sandstone compositions marks the transition from Indian to Asian sediment provenance. The abrupt compositional change is accompanied by changes in U-Pb ages of detrital zircons diagnostic of a sediment provenance reversal, from Indian to Asian sources. The timing of the transition is bracketed between ~60 Ma and 58.5 ± 0.6 Ma by detrital zircon U-Pb ages and zircon U-Pb ages from a tuffaceous bed in the upper part of the section. In the context of a palinspastically restored regional paleogeographic framework, data from the Sangdanlin section combined with previously published data from the northern Tethyan Himalaya and the frontal Nepalese Lesser Himalaya and Subhimalaya suggest that a flexural wave migrated ~1300 km southward across what is now the Himalayan thrust belt from Paleocene time to the present.

DeCelles, P. G.; Kapp, P.; Gehrels, G. E.; Ding, L.

2014-05-01

347

Inclination shallowing in Eocene Linzizong sedimentary rocks from Southern Tibet: correction, possible causes and implications for reconstructing the India-Asia collision  

NASA Astrophysics Data System (ADS)

A systematic bias towards low palaeomagnetic inclination recorded in clastic sediments, that is, inclination shallowing, has been recognized and studied for decades. Identification, understanding and correction of this inclination shallowing are critical for palaeogeographic reconstructions, particularly those used in climate models and to date collisional events in convergent orogenic systems, such as those surrounding the Neotethys. Here we report palaeomagnetic inclinations from the sedimentary Eocene upper Linzizong Group of Southern Tibet that are ˜20° lower than conformable underlying volcanic units. At face value, the palaeomagnetic results from these sedimentary rocks suggest the southern margin of Asia was located ˜10°N, which is inconsistent with recent reviews of the palaeolatitude of Southern Tibet. We apply two different correction methods to estimate the magnitude of inclination shallowing independently from the volcanics. The mean inclination is corrected from 20.5° to 40.0° within 95 per cent confidence limits between 33.1° and 49.5° by the elongation/inclination (E/I) correction method; an anisotropy-based inclination correction method steepens the mean inclination to 41.3 ± 3.3° after a curve fitting- determined particle anisotropy of 1.39 is applied. These corrected inclinations are statistically indistinguishable from the well-determined 40.3 ± 4.5º mean inclination of the underlying volcanic rocks that provides an independent check on the validity of these correction methods. Our results show that inclination shallowing in sedimentary rocks can be corrected. Careful inspection of stratigraphic variations of rock magnetic properties and remanence anisotropy suggests shallowing was caused mainly by a combination of syn- and post-depositional processes such as particle imbrication and sedimentary compaction that vary in importance throughout the section. Palaeolatitudes calculated from palaeomagnetic directions from Eocene sedimentary rocks of the upper Linzizong Group that have corrected for inclination shallowing are consistent with palaeolatitude history of the Lhasa terrane, and suggest that the India-Asia collision began at ˜20°N by 45-55 Ma.

Huang, Wentao; Dupont-Nivet, Guillaume; Lippert, Peter C.; van Hinsbergen, Douwe J. J.; Hallot, Erwan

2013-09-01

348

The impact of indoor residual spraying with malathion on malaria in refugee camps in eastern Sudan  

Microsoft Academic Search

An exploratory trial of the efficacy of indoor spraying with malathion on morbidity and mortality in refugee camps in eastern Sudan was conducted during the rainy season of 1997. The interior walls of houses from a randomly selected group of five camps were sprayed with malathion in mid-September and morbidity and mortality rates in the camps for the months October

J. D. Charlwood; M. Qassim; E. I. Elnsur; M. Donnelly; V. Petrarca; P. F. Billingsley; J. Pinto; T. Smith

2001-01-01

349

An analysis of mortality trends among refugee populations in Somalia, Sudan, and Thailand*  

PubMed Central

A review of mortality data from refugee camps in Thailand (1979-80), Somalia (1980-85), and Sudan (1984-85) indicates that crude mortality rates (CMRs) were up to 40 times higher than those for the non-refugee populations in the host countries. In eastern Sudan, approximately 5% of the population of eight camps died in the first 3 months of the emergency and daily CMRs as high as 14 per 10 000 were reported. These rates dropped to values comparable with those of the host country within 6 weeks in the Thai camps; however, in Somalia and Sudan this process took 12 months. Mortality rates among under-5-year olds in the early phases, which were as high as 32.6 per 10 000 per day, are six times greater than those in the world's least developed countries during non-emergency times. Among severely undernourished children in one camp in Sudan, the death rate reached 114 per 10 000 per day. Acute respiratory infections, diarrhoeal diseases, malaria, measles, and undernutrition were the causes of most reported deaths, the majority of which could have been prevented by adequate food rations, clean water, measles immunization, and an oral rehydration programme.

Toole, M. J.; Waldman, R. J.

1988-01-01

350

Molecularly imprinted microspheres as SPE sorbent for selective extraction of four Sudan dyes in catsup products.  

PubMed

A highly selective molecularly imprinted solid-phase extraction (MISPE) coupled with high performance liquid chromatography (HPLC) ultraviolet-visible detection was developed for the simultaneous isolation and determination of four Sudan dyes (I, II, III and IV) in catsup products. The novel molecularly imprinted microspheres (MIM) were synthesized by aqueous suspension polymerization using phenylamine and naphthol as template, which showed high affinity to Sudan dyes in aqueous solution. In order to develop a selective extraction protocol for simultaneous determination the four Sudan dyes from catsup products, the molecular recognition properties of MIM as a SPE sorbent were evaluated. Under the optimized condition, good linearity was obtained from 0.01 to 2.5 ?g g(-1) (r(2)? 0.9990) with the relative standard deviations of less than 3.4%. This proposed MISPE-HPLC procedure eliminated the effect of template leakage on quantitative analysis and could be applied to direct determination of four Sudan dyes in complicated food samples. PMID:21900053

Qiao, Fengxia; Geng, Yuru; He, Changqing; Wu, Yupei; Pan, Pengyu

2011-10-01

351

Famine Mitigation Bibliography: With Special Emphasis on Ethiopia, Sudan and Angola. First Edition.  

National Technical Information Service (NTIS)

The bibliography documents a specialized data base on famine mitigation. The database's strength lies in its coverage of Sudan, Angola, Ethiopia and its focus on nine short-term interventions with potential long-term benefits: (1) early warning; (2) rapid...

B. Hutchinson K. Johnsen M. Haseltine C. Casler

1992-01-01

352

A Basic Hybrid Library Support Model to Distance Learners in Sudan  

ERIC Educational Resources Information Center

Distance learning has flourished in Sudan during the last two decades; more and more higher education institutions offer distance learning programmes to off-campus students. Like on-campus students, distance learners should have access to appropriate library and information support services. They also have specific needs for library and…

Abdelrahman, Omer Hassan

2012-01-01

353

Nonmarine Cretaceous palynology of northern Kordofan, Sudan, with notes on fossil Salviniales (water ferns)  

Microsoft Academic Search

A palynological investigation of 164 samples from 18 water wells in northern Kordofan, Sudan, enabled the recognition of five informal zones based on pollen and spore assemblages ranging in age from Albian to Maastrichtian. The youngest (late Campanian-Maastrichtian) assemblages are restricted to the Bagbag Basin, whereas Albian-Cenomanian (to Turonian) sediments are widespread to the east and west of the Bagbag

E. Schrank

1994-01-01

354

Improved stoves in Sub-Saharan Africa: the case of the Sudan  

Microsoft Academic Search

The paper estimates charcoal demand and supply elasticities to determine rebound effects from improved stoves in the Sudan. These are increases in fuel consumption resulting from gains in real income upon the use of more efficient appliances, and from downward price adjustments associated with the reduction in fuel requirements. The findings are that: (1) charcoal markets are characterized by low

Eiman O. Zein-Elabdin

1997-01-01

355

Fluorescent nanomicelles for selective detection of Sudan dye in Pluronic F127 aqueous media.  

PubMed

Novel self-assembled water-soluble nanomicelles that contain fluorescent conjugated polymers (poly(9,9-dioctylfluorene) (PFO) or poly[2,7-(9,9-dihexylfluorene)-alt-4,4'-phenylether] (PF-PE)) have been obtained and used as the highly sensitive/selective platform for Sudan dye detection. The Fluorescent nanomicelles exhibited a highly selective fluorescence quenching by the prohibited food additive Sudan I, while not for the natural pigments: Capsanthin and Beta-carotene, due to the more suitable matching of the LUMOs (lowest unoccupied molecular orbital) of the conjugated polymers with that of Sudan I molecules. The Stern-Volmer constants (K(SV)) of PF-PE/F127 and PFO/F127 for Sudan I were 1,040,480 and 665,000 M(-1), respectively, which were more than 100 times higher than those of the same conjugated polymers in the orgainc solvents. The significantly enhanced sensitivity was due to the collective effect of the F127 micelles to both chromophore and analyte, through which the fluorophone-analyte binding interaction is significantly strengthened and efficient photoinduced charge transfer occurs. The as-proposed materials and approach may be potentially applied in the real-time food safety screening. PMID:24625370

Ye, Xinliang; Zhang, Jie; Chen, Hui; Wang, Xiaohui; Huang, Fei

2014-04-01

356

Geologic assessment of the fossil energy and geothermal potential of the Sudan  

SciTech Connect

This preliminary report provides geological input to the consideration of appropriate activities that can enhance the exploration and development of fossil-fuel and possible geothermal energy resources of the Sudan, and is based on study of available literature in early 1982. 59 references, 16 figures, 7 tables.

Setlow, L.W.

1983-01-01

357

3 CFR - Certification Concerning U.S. Participation in the United Nations Mission in South Sudan...  

Code of Federal Regulations, 2013 CFR

...Republic of South Sudan is not a party to the ICC and has not invoked the jurisdiction of the ICC pursuant to Article 12 of the Rome Statute. You are authorized and directed to publish this determination in the Federal Register .BARACK OBAMATHE WHITE...

2013-01-01

358

The Sociolinguistics of Nationalism in the Sudan: The Politicisation of Arabic and the Arabicisation of Politics  

ERIC Educational Resources Information Center

This monograph describes the historiography of language ideologies that led to the politicisation of Arabic and the Arabicisation of politics in the Sudan, starting from British colonial rule until the Comprehensive Peace Agreement that was a precursor to the separation of the South as an independent state. The monograph shows that the…

Abdelhay, Ashraf; Makoni, Busi; Makoni, Sinfree; Mugaddam, Abdel Rahim

2011-01-01

359

Rift Valley fever among febrile patients at New Halfa hospital, eastern Sudan  

Microsoft Academic Search

BACKGROUND: Since the first isolation of the Rift Valley Fever virus (RVFV) in 1930s, there have been several epizootics outbreaks in the tropic mainly in Africa including Sudan. Recognition of cases and diagnosis of RVF are critical for management and control of the disease. AIMS: To investigate the seroprevalence and risk factors for seropostive to RVFV IgG among febrile patients.

Ahmed M Hassanain; Waleed Noureldien; Mubarak S Karsany; El najeeb S Saeed; Imadeldin E Aradaib; Ishag Adam

2010-01-01

360

Relationship of the Sickle Cell Gene to the Ethnic and Geographic Groups Populating the Sudan  

Microsoft Academic Search

The presence of a geographical pattern in the distribution of the sickle cell gene (S gene) and its association with malaria is well documented. To study the distribution of the S gene among various ethnic and linguistic groups in the Sudan we analyzed a hospital-based sample of 189 sickle cell anemia (SCA) patients who reported to the Khartoum Teaching Hospital

Abdelrahim O. Mohammed; Bekhieta Attalla; Fathya M. K. Bashir; Fatima E. Ahmed; Ahmed M. El Hassan; Gafar Ibnauf; Weiying Jiang; Luigi L. Cavalli-Sforza; Zein Al Abdin Karrar; Muntaser E. Ibrahim

2006-01-01

361

Delineation of groundwater zones using lithology and electric tomography in the Khartoum basin, central Sudan  

Microsoft Academic Search

The three towns of Khartoum, Omdurman and Khartoum are located north of the capital of Sudan. This capital has agglomerated to reach more than 7 million inhabitants. The present situation is confronted with a dramatic shortage in freshwater supply. The treatment of surface water from the Nile became costly, particularly in flood season. Thus the authorities turned towards developing groundwater

Mohammed Tahir Hussein; Hussein Salim Awad

2006-01-01

362

Development of a new method for analysis of Sudan dyes by pressurized CEC with amperometric detection.  

PubMed

A new analytical method, pressurized CEC (pCEC) with amperometric detection (AD) using 1.5 microm RP nonporous silica packed columns has been developed for the rapid separation and determination of four Sudan dyes in hot chilli. The influence of several experimental parameters on the retention behavior has been investigated. The electrochemical oxidation of Sudans I-IV separated by pCEC can be reliably monitored with a carbon electrode at +0.95 V (vs. Ag/AgCl). Fast and efficient separation of the analytes was achieved within 7 min by pCEC under the optimum conditions with an ACN/water (95:5%) mobile phase containing formic acid (pH 4.3), 5% acetone and 0.002% triethylamine using a separation voltage of 12 kV. The detection limits for four Sudan dyes ranged from 8.0 x 10(-7) to 1.2 x 10(-6) mol/L. To evaluate the feasibility and reliability of this method, the proposed pCEC-AD method was further demonstrated with hot chilli samples spiked with Sudan dyes. PMID:17465422

Liu, Shaofeng; Zhang, Xue; Lin, Xucong; Wu, Xiaoping; Fu, Fengfu; Xie, Zenghong

2007-06-01

363

Spectrophotometric Studies of the Complexation of Sudan Red B with Co and Ni Ions  

Microsoft Academic Search

Sudan Red B, an azo dye, was used as a reagent for the complexation of Ni and Co ions. The studies were carried out spectrophotometrically. The absorption spectra were monitored and the conditions were optimized in terms of dye and metal concentration, pH, and cationic and anionic effects. The log ? (stability constants) of the metal–dye complex were calculated using

M. A. Rauf; Z. Akhter; S. Kanwal

2003-01-01

364

Photometric studies of the complexation of Sudan Red B with Mn +2 and Fe +3 ions  

Microsoft Academic Search

A representative azo dye by the name of Sudan Red B, was used as a complexing reagent for Ni and Co ions. Photometric method was used to monitor the metal to ligand formation. The absorption spectra were monitored and the conditions were optimized in terms of dye and metal concentration, pH, and cationic and anionic effects. The log ? (stability

M. A. Rauf; Z. Akhter; S. Kanwal

2004-01-01

365

Removal of sudan dyes from water with C18-functional ultrafine magnetic silica nanoparticles.  

PubMed

In this study, the new C(18)-functionalized ultrafine magnetic silica nanoparticles (C(18)-UMS NPs) were successfully synthesized and applied for extraction of sudan dyes in water samples based on the magnetic solid-phase extraction (MSPE). The extraction and concentration were carried out in one step by blending C(18)-UMS NPs and water samples. The sudan dyes adsorbed C(18)-UMS NPs were isolated from the matrix easily with an external magnetic field. After desorption the quantitation of sudan dyes was done by ultra fast liquid chromatography (UFLC). Satisfactory extraction recovery can be obtained with only 50 mg C(18)-UMS NPs. The effects of experimental parameters, including the amount of the nanoparticles, extraction time, pH value, desorption solvent, volume of desorption solvent and desorption time were investigated. The limits of detection for sudan I, II, III and IV were 0.066, 0.070, 0.12 and 0.12 ng mL(-1), respectively. Recoveries obtained by analyzing the six spiked water samples were between 68% and 103%. PMID:22284457

Jiang, Chunzhu; Sun, Ying; Yu, Xi; Zhang, Lei; Sun, Xiumin; Gao, Yan; Zhang, Hanqi; Song, Daqian

2012-01-30

366

Epidermal Hyperplasia Induced in Guinea Pig Flank Skin by Intradermal Injection of Sudan Red  

Microsoft Academic Search

Studies of dermal-epidermal interactions were conducted with guinea pig flank skin and intradermal injections of the irritant, Sudan IV dye in olive oil. These injections led to epidermal hyperplasia in areas overlying the irritant and the effect was most significant when the irritant was placed in the upper dermis. Basal cell mitotic activity and thymidine uptake reached a peak by

K. S. Stenn

1979-01-01

367

Sudan: Humanitarian Crisis, Peace Talks, Terrorism, and U.S. Policy.  

National Technical Information Service (NTIS)

Sudan has been ravaged by civil war intermittently for 4 decades. An estimated 2 million people have died over the past two decades due to war-related causes and famine, and millions have been displaced from their homes. The 21-year civil war continues to...

T. Dagne

2005-01-01

368

Sudan: Humanitarian Crisis, Peace Talks, Terrorism, and U.S. Policy.  

National Technical Information Service (NTIS)

Sudan has been ravaged by civil war intermittently for 4 decades. An estimated 2 million people have died over the past two decades due to war- related causes and famine, and millions have been displaced from their homes. The 21-year civil war continues t...

T. Dagne

2005-01-01

369

Sudan: Humanitarian Crisis, Peace Talks, Terrorism, and U.S. Policy.  

National Technical Information Service (NTIS)

Sudan, geographically the largest country in Africa, has been ravaged by civil war intermittently for four decades. An estimated 2 million people have died over the past two decades due to war-related causes and famine, and millions have been displaced fr...

T. Dagne

2006-01-01

370

Prevalence and risk factors for Plasmodium falciparum malaria in pregnant women of eastern Sudan  

Microsoft Academic Search

BACKGROUND: Pregnant women are more susceptible to malaria, which is associated with serious adverse effects on pregnancy. The presentation of malaria during pregnancy varies according to the level of transmission in the area. Our study aimed to demonstrate the prevalence and risk factors for malaria (age, parity and gestational age) among pregnant women of eastern Sudan, which is characterized by

Ishag Adam; Amar H Khamis; Mustafa I Elbashir

2005-01-01

371

In situ ionic-liquid-dispersive liquid-liquid microextraction of Sudan dyes from liquid samples.  

PubMed

In situ ionic-liquid-dispersive liquid-liquid microextraction was introduced for extracting Sudan dyes from different liquid samples followed by detection using ultrafast liquid chromatography. The extraction and metathesis reaction can be performed simultaneously, the extraction time was shortened notably and higher enrichment factors can be obtained compared with traditional dispersive liquid-liquid microextraction. When the extraction was coupled with ultrafast liquid chromatography, a green, convenient, cheap, and efficient method for the determination of Sudan dyes was developed. The effects of various experimental factors, including type of extraction solvent, amount of 1-hexyl-3-methylimidazolium chloride, ratio of ammonium hexafluorophosphate to 1-hexyl-3-methylimidazolium chloride, pH value, salt concentration in sample solution, extraction time and centrifugation time were investigated and optimized for the extraction of four kinds of Sudan dyes. The limits of detection for Sudan I, II, III, and IV were 0.324, 0.299, 0.390, and 0.655 ng/mL, respectively. Recoveries obtained by analyzing the seven spiked samples were between 65.95 and 112.82%. The consumption of organic solvent (120 ?L acetonitrile per sample) was very low, so it could be considered as a green analytical method. PMID:24840862

Xu, Bo; Song, Daqian; Wang, Yuanpeng; Gao, Yan; Cao, Bocheng; Zhang, Hanqi; Sun, Ying

2014-08-01

372

New c. 270 kyr strike-slip and uplift rates for the southern Alpine Fault and implications for the New Zealand plate boundary  

NASA Astrophysics Data System (ADS)

Along 100 km of the Alpine Fault, major valleys and glacial deposits can be matched across an 8000 m dextral offset. We use paleontologic and stratigraphic age constraints to date c. 270 ka marine sediments uplifted to 600 m elevation and overlying c. 270 ka glacial deposits related to the 8000 m dextral offset. These constraints yield a fault-proximal Australian plate uplift rate of 2.6 (-0.5/+0.4) mm/yr and an Alpine Fault dextral slip rate of 29.6 (-2.5/+4.5) mm/yr. Our rates resolve an apparent along-strike drop in strike-slip rate and instead support a relatively constant along-strike dextral slip rate of ?28 mm/yr (?80% of current Australian-Pacific plate boundary motion). We argue that the rate of dextral slip on the southern Alpine Fault has been relatively constant over the last ?3.5 myr, and that ductile fault processes may rate-limit the fault from accommodating a progressively higher percentage of plate boundary motion through time (i.e., the fault reached maturity long ago). The spatiotemporally constant strike-slip rate of the southern Alpine Fault and a previously published paleoseismic record of near-regular earthquake recurrence both characterize the Alpine Fault as a mature plate boundary fault zone that behaves in a constant way with behavior predictable over timescales of thousands and hundreds of thousands of years.

Barth, N. C.; Kulhanek, D. K.; Beu, A. G.; Murray-Wallace, C. V.; Hayward, B. W.; Mildenhall, D. C.; Lee, D. E.

2014-07-01

373

Anionic surfactant linear alkylbenzene sulfonates (LAS) in sediments from the Gulf of Gda?sk (southern Baltic Sea, Poland) and its environmental implications.  

PubMed

Linear alkylbenzene sulfonate (LAS) is a group of anionic surfactants employed in the formulation of laundry and cleaning products, with a global production rate of 4 million metric tons. Sediments from the Polish coast of the southern Baltic Sea were collected at ten stations. Total LAS concentrations, measured by high-performance liquid chromatography, were between 0.04 and 0.72 mg LAS·kg(-1) dry weight. Highest LAS concentrations were found in suspended matter collected from the Vistula River, sediment collected close to the Vistula River mouth and from the Gda?sk Deep, known as the depositional area. With the obtained environmental LAS concentrations, a risk assessment for this surfactant has been carried out, based on publicly available acute and chronic toxicity data in target organisms. The results indicated that LAS could pose a low risk for the existing benthic community applying worst case scenario assessment. This is the first time that levels of LAS have been measured in environmental samples of the southern Baltic Sea. PMID:22006264

Hampel, Miriam; Mauffret, Aourell; Pazdro, Ksenia; Blasco, Julian

2012-10-01

374

Construction of Late Devonian Dundunshan arc in the Beishan orogen and its implication for tectonics of southern Central Asian Orogenic Belt  

NASA Astrophysics Data System (ADS)

The Beishan orogen, located in the southern Central Asian Orogenic Belt, was formed by subduction-accretionary processes in the Paleozoic, and so provides key constraints on the current international controversy regarding the duration of the orogenesis and the time of its termination and formation of the final suture. This paper concerns the tectonic setting, in the Beishan, of Devonian volcanic and sedimentary rocks that belong to the Dundunshan subduction-generated volcanic arc. The Dundunshan arc comprises metaluminous to weakly peraluminous, calc-alkaline andesites, dacites, rhyolites, porphyries and tuffs, which have Late Devonian U-Pb zircon ages of 368.8 ± 3.1 Ma and 370.9 ± 1.3 Ma. The rhyolites have an arc geochemical signature. The Dundunshan sediments are predominantly clastic sandstones, the trace element geochemical data of which indicate derivation from a rhyolitic source with variable degrees of weathering, suggesting an active tectonic provenance. The Dundunshan arc is situated on the southern side of the Huaniushan arc, which, according to current published data, was generated by northward subduction in the Early Paleozoic, and this was followed by the Dundunshan arc in the Late Devonian. It is likely that the northward-dipping subduction zone retreated southwards, giving rise to southward younging of the arcs. Our data provide important constraints on a better understanding of the growth of arcs that dominate the Altaid accretionary orogen.

Guo, Qianqian; Xiao, Wenjiao; Hou, Quanlin; Windley, Brian F.; Han, Chunming; Tian, Zhonghua; Song, Dongfang

2014-01-01

375

Structure of Tendaho Graben and Manda Hararo Rift: Implications for the evolution of the southern Red Sea propagator in Central Afar  

NASA Astrophysics Data System (ADS)

The Red Sea and Aden rifts (or propagators) meet in Afar. Here we use remote sensing and field analyses to define the geology and structure of the southern part of the Red Sea propagator in Central Afar. This consists of the NW-SE trending Tendaho Graben (TG) and the younger and active NW-SE trending Manda Hararo Rift (MHR), partly within TG. Tectonic and volcanic activity within TG developed mostly between ˜1.8 and ˜0.6 Ma, with a stretching factor ? ˜ 1.1, an extension rate ˜3.6 mm/yr and the fissural eruption of part (˜7000 km3/Ma) of the Afar Stratoid sequence (mainly basaltic lava flows and ignimbrites). MHR, before terminating southward, has a ? ˜ 1.04 and an extension rate ˜1.2 mm/yr, and is associated with the emission of ˜600 km3/Ma of basalts in the last ˜0.2 Ma. These data suggest that after the exceptional amount of magma erupted between ˜1.8 and ˜0.6 Ma, magmatic and tectonic activity significantly decreased along the southern part of the Red Sea propagator in the last ˜0.2 Ma. This decrease coincides with the on-land development and migration of the more active (inferred extension rate in the order of ˜10 mm/yr, as proposed in previous studies) Aden propagator, suggesting that spreading in Central Afar mainly occurred along one active propagator at any one time.

Acocella, V.; Abebe, B.; Korme, T.; Barberi, F.

2008-08-01

376

Petroleum maturation modelling, Abu Gabra Sharaf area, Muglad Basin, Sudan  

NASA Astrophysics Data System (ADS)

Structural and maturation studies in the northwest of the Muglad Basin, Sudan showed a thick sedimentary section up to 9000 m in the deep sub-basins and an average of about 6000 m in the Sharaf-Abu Gabra Ridge. The isopach map of the Lower Cretaceous Abu Gabra-Sharaf formations, which contain source rocks, showed a thickness of sedimentary section between 2000 and 5000 m. The burial history showed high subsidence rates during the first rifting phase with relatively low subsidence rates during the following two phases in this part of the basin. Significant erosion of the sedimentary section occurred in the ridge area during Miocene and Cenomanian-Albian times. The geothermal gradients in the modelled wells range between 18 and 27.5 °C/km corresponding to the relatively wide range of present day heat flow of between 37 and 63 mW/m 2, averaging 50 mW/m 2. Heat flow history curves consistent with vitrinite reflectance data were adopted with elevated high heat flow (75 mW/m 2) during the first rifting phase followed by minor peaks (average 60 mW/m 2) during the second and the third rifting phases. Application of a kinetic vitrinite maturation model resulted in a present day oil window between 2000 and 4500 m. The source rock of the Abu Gabra (AG) and Sharaf (SH) formations, which has an average total organic carbon of 1.0% and hydrogen index (HI) of 280, was modelled for hydrocarbon generation. The section was divided into four layers; AG-1 (Albian), AG-2 (Aptian), SH-1 (Barremian) and SH-2 (Neocomian). Conditions for hydrocarbon generation are present throughout the Sharaf formation and in AG-2. The generation model suggests an average generation amount of 4 mgHC/g rock in the lower three modelled layers with a timing range between 120 Ma and the present. Total calculated oil volume is about 370 US billion bbls and the expected volume expelled and migrated (40%) is 150 US billion bbls. The total gas expelled and migrated (90%) is 1600 US trillion cu ft. Retention of hydrocarbons may be adversely affected by long-continued faulting and lack of good seals.

Mohamed, Abdalla Y.; Pearson, Michael J.; Ashcroft, William A.; Whiteman, A. J.

2002-08-01

377

Evidence for large-magnitude paleo-earthquakes on the Ventura fault: Implications for earthquake recurrence, fault slip rate, and seismic hazard assessment in southern California  

NASA Astrophysics Data System (ADS)

New borehole, high-resolution seismic reflection, and geochronologic data reveal the ages and displacements of the two most recent large-magnitude earthquakes on the Ventura fault, the central segment of a large, multi-fault reverse fault system that extends for >200 km along the southern edge of the central and western Transverse Ranges fault system. Based on geomorphology and analysis of high-resolution seismic data acquired in 2010, we drilled 17 hollow stem auger boreholes and cone penetrometer tests along two transects across the locus of most recent folding above the Ventura fault. At Day Road in downtown Ventura, our 23-m-deep boreholes revealed a well-bedded alluvial section with many units that are traceable continuously along the entire 375 m length of the transect. Stratigraphic relationships indicate that the prominent topographic scarp at this site records ~6 m of uplift during fold growth in the most-recent earthquake on the underlying Ventura blind thrust ramp. Similarly, sedimentary growth observed in the borehole cross section indicates ~4.5 m of growth during the penultimate event, with an event horizon located at the base of a growth interval between 4 and 8.5 m depth south of the scarp. Six 14C and 14 OSL ages collected from the four hollow-stem auger boreholes at this site constrain the timing of the two most recent events on the Ventura blind thrust fault to post-2900 B.P. and 4700 × 350 to 5460 × 330 years before present; dating of additional shallow luminescence samples should help narrow the age range of the MRE. The large amounts of uplift in the two folding events indicate that they formed in response to large-displacement, and therefore large-magnitude earthquakes, likely involving rupture of the Ventura fault together with thrust ramps to both the west (e.g., Pitas Point fault) and east (Southern San Cayetano and eastern San Cayetano faults). These thrust faults form the middle section of a >200-km-long, east-west belt of large, interconnected reverse faults that extends along the southern edge of the Transverse Ranges. Although each of these faults represents a major seismic source in its own right, we are exploring the possibility of even larger-magnitude, multi-segment ruptures that may link these faults to other major faults to the east and west. The proximity of this large reverse-fault system to several major population centers, including the metropolitan Los Angeles region, and the potential for tsunami generation during offshore ruptures of the western parts of the system, emphasize the importance of understanding the behavior of these faults for seismic hazard assessment.

Mcauliffe, L. J.; Dolan, J. F.; Hubbard, J.; Shaw, J. H.; Pratt, T. L.; Rhodes, E. J.

2013-12-01

378

Detoxication products of the carcinogenic azodye Sudan I (solvent yellow 14) bind to nucleic acids after activation by peroxidase.  

PubMed

The C-hydroxyderivatives of the carcinogenic dye Sudan I, 1-phenylazo-2,6-dihydroxynaphthalene and 1-(4-hydroxyphenylazo)-2-hydroxynaphthalene, which are considered to be detoxication products of this dye bind to DNA or tRNA after oxidation into active metabolites by peroxidase and H2O2 in vitro. The 32P-postlabeling analysis of DNA modified by active metabolites of both Sudan I derivatives provides evidence that the covalent binding to DNA is the principal type of DNA modification. Since the urinary bladder is rich in peroxidases, the participation of these enzymes in activation of detoxicating products of Sudan I may be involved in the initiation of Sudan I-carcinogenesis in this organ. PMID:8422648

Stiborová, M; Frei, E; Schmeiser, H H; Wiessler, M; Hradec, J

1993-01-15

379

Role of the Government in Perpetrating Genocide: A Comparative Analysis of 1994 Rwanda Genocide and 2003 Sudan Genocide.  

National Technical Information Service (NTIS)

Rwanda and Sudan present two of the most recent examples of governments responsible for perpetrating genocide. The extremist ethnic Hutu government planned and executed the 1994 Rwanda genocide against the Tutsi ethnic minority culminating in the death of...

R. Rwivanga

2013-01-01

380

Polymerase Chain Reaction Pool Screening Used To Compare Prevalence of Infective Black Flies in Two Onchocerciasis Foci in Northern Sudan  

PubMed Central

Onchocerciasis remains an important debilitating disease in many areas of Africa, including Sudan. The status of infection transmission in 2007 was assessed in the vectors of two disease foci in Sudan: Abu Hamed in northern Sudan, which has received at least 10 years of annual treatment and Galabat focus in eastern Sudan, where only minor, largely undocumented treatment activity has occurred. Assessment of more than 30,000 black flies for Onchocerca volvulus infectious stage L3 larvae by using an O-150 polymerase chain reaction protocol showed that black fly infectivity rates were 0.84 (95% confidence interval = 0.0497–1.88) per 10,000 flies for Abu Hamed and 6.9 (95% confidence interval = 1.1–16.4) infective flies per 10,000 for Galabat. These results provide entomologic evidence for suppressed Onchocerca volvulus transmission in the Abu Hamed focus and a moderate transmission rate of the parasite in the Galabat focus.

Higazi, Tarig B.; Zarroug, Isam M. A.; Mohamed, Hanan A.; Mohamed, Wigdan A.; Deran, Tong Chor M.; Aziz, Nabil; Katabarwa, Moses; Hassan, Hassan K.; Unnasch, Thomas R.; Mackenzie, Charles D.; Richards, Frank

2011-01-01

381

New paleomagnetic data from Late Neoproterozoic sedimentary successions in Southern Urals, Russia: implications for the Late Neoproterozoic paleogeography of the Iapetan realm  

NASA Astrophysics Data System (ADS)

We present the results of paleomagnetic study of Ediacaran sedimentary successions from the Southern Urals. The analysis of the sedimentary rocks of the Krivaya Luka, Kurgashlya and Bakeevo Formations reveal stable mid-temperature and high-temperature remanence components. Mid-temperature components were acquired during Devonian (Bakeevo Formation) and Late Carboniferous-Early Permian remagnetization events. The high-temperature components in Kurgashlya and Bakeevo Formations are interpreted to be primary, because they are supported by a positive conglomerate test (Bakeevo Formation) and magnetostratigraphic pattern (Kurgashlya Formation). The high-temperature component in the Krivaya Luka Formation is interpreted to be a Late Ediacaran overprint. Our new paleomagnetic poles together with some previously published Ediacaran poles from Baltica and Laurentia are used herein to produce a series of paleogeographic reconstructions of the opening of the Iapetus Ocean.

Lubnina, Natalia V.; Pisarevsky, Sergei A.; Puchkov, Victor N.; Kozlov, Vjacheslav I.; Sergeeva, Nina D.

2014-04-01

382

A New Estimate for Total Offset on the Southern San Andreas Fault: Implications for Cumulative Plate Boundary Shear in the Northern Gulf of California  

NASA Astrophysics Data System (ADS)

Development of a consistent and balanced tectonic reconstruction for the late Cenozoic San Andreas fault (SAF) in southern California has been hindered for decades by incompatible estimates of total dextral offset based on different geologic cross-fault markers. The older estimate of 240-270 km is based on offset fluvial conglomerates of the middle Miocene Mint Canyon and Caliente Formations west of the SAF from their presumed source area in the northern Chocolate Mountains NE of the SAF (Ehlig et al., 1975; Ehlert, 2003). The second widely cited offset marker is a distinctive Triassic megaporphyritic monzogranite that has been offset 160 ± 10 km between Liebre Mountain west of the SAF and the San Bernadino Mountains (Matti and Morton, 1993). In this analysis we use existing paleocurrent data and late Miocene clockwise rotation in the eastern Transverse Ranges (ETR) to re-assess the orientation of the piercing line used in the 240 km-correlation, and present a palinspastic reconstruction that satisfies all existing geologic constraints. Our reconstruction of the Mint Canyon piercing line reduces the original estimate of 240-270 km to 195 ± 15 km of cumulative right-lateral slip on the southern SAF (sensu stricto), which is consistent with other published estimates of 185 ± 20 km based on correlative basement terranes in the Salton Trough region. Our estimate of ~195 km is consistent with the lower estimate of ~160 km on the Mojave segment because transform-parallel extension along the southwestern boundary of the ETR during transrotation produces ~25-40 km of displacement that does not affect offset markers of the Liebre/San Bernadino correlation located northwest of the ETR rotating domain. Reconciliation of these disparate estimates places an important new constraint on the total plate boundary shear that is likely accommodated in the adjacent northern Gulf of California. Global plate circuit models require ~650 km of cumulative Pacific-North America (PAC-NAM) relative plate motion since ~12 Ma (Atwater and Stock, 1998). We propose that the continental component of PAC-NAM shear is accommodated by: (1) 195 ± 15 km on the southern SAF (this study); (2) 12 ± 2 km on the Whittier-Elsinore fault; (3) 75 ± 20 km of cumulative shear across the central Mojave in the eastern California shear zone; (4) 30 ± 4 km of post-13 Ma slip on the Stateline fault; and (5) 47 ± 18 km of NW-directed translation produced by north-south shortening. Together, these components sum to 359 ± 31 km of net dextral displacement on the SAF system (sensu lato) in southern California since ca. 12 Ma, or ~300 km less than what is required by the global plate circuit. This suggests that the continental component of post-12 Ma PAC-NAM transform motion can be no more than ~390 km in the adjacent northern Gulf of California, substantially less than the 450 km of shear proposed in some models. We suggest that the remaining ~270-300 km of NW-directed relative plate motion is accommodated by a small component of late Miocene extension and roughly 225 km of slip on the offshore borderland fault system west of Baja California.

Darin, M. H.; Dorsey, R. J.

2012-12-01

383

U-Cr-rich high Mg-Al granulites from Karimnagar Granulite Belt, India: implications for Neoarchean-Paleoproterozoic events in southern India  

NASA Astrophysics Data System (ADS)

High Mg-Al granulite occurs as enclave within granite gneisses at Karimnagar, southern India, and it contains coarse granoblastic aggregates of orthopyroxene and sapphirine with minor amount of cordierite, spinel and phlogopite. An important chemical characteristic of these minerals is their extremely high MgO content and the high Cr2O3 in sapphirine and spinel. Textural analysis shows sapphirine + orthopyroxene + cordierite as the peak-metamorphic assemblage that possibly evolved though the breakdown of a spinel-bearing assemblage. Cation exchange geothermometers involving orthopyroxene, sapphirine and spinel yield temperatures of 600-800 °C with a maximum of 860 °C implying an event of high temperature (HT) metamorphism. Pseudosection analysis in the FeO-MgO-Al2O3-SiO2 chemical system shows the stability of the peak- assemblage below 6.2 kbar. Subsequently, the rock underwent hydration and cooling with the appearance of phlogopite in the assemblage. Chromium enrichment is possibly inherited from the protolith and its presence presumably stabilized sapphirine and spinel below their high-temperature stability field. The recorded Rb-Sr age of ca. 2,500 Ma in host granite gneiss marks the upper age limit of HT metamorphism. Presence of patchy, lobate grains as well as veinlets of uraninite and brannerite is also a characteristic feature of the rock. Uranium mineralization took place during the post peak metamorphic stage, sulfide mineralization represented by tiny grains and veinlets of pyrite, millerite and pentlandite coincided with, and outlasted the uranium mineralization. The U-Th-Pb chemical ages of uraninite grains suggest ca. 2,200 ± 12 Ma for the age of uranium mineralization in the granulite. Based on the field relations, it is surmised that the granulite metamorphism in the study area is older than ca. 2,500 Ma and is comparable with an event in the other parts of Eastern Dharwar Craton. It can be conceived as a widespread event in southern India.

Sarbajna, Chanchal; Bose, Sankar; Rajagopalan, V.; Das, Kaushik; Som, Anjan; Paul, A. K.; Shivkumar, K.; Umamaheswar, K.; Chaki, Anjan

2013-08-01

384

A seismicity burst following the 2010 M6.4 Jiashian earthquake - implications for short-term seismic hazards in southern Taiwan  

NASA Astrophysics Data System (ADS)

Following the 4 March 2010 Mw 6.4 Jiashian earthquake the seismicity rate in southern Taiwan was determined to be significantly higher than before the quake and aroused seismic hazard awareness. In this work, seismic hazards were investigated in terms of earthquake activity, the Coulomb stress change, the rate-and-state friction model, and short-term seismic hazard assessments. The significantly higher seismicity rate that followed the 2010 Jiashian earthquake was found to mainly be attributed to aftershock decay, in terms of the modified Omori formula. The results suggest that aftershock duration may continue until the end of 2012. The spatial migration of seismicity was modeled using the Coulomb stress changes of large earthquakes. Most of the consequent events were distributed in the vicinity of large earthquakes. The observations corresponded to a remarkable stress increase within the same area. Additionally, large events were located within regions with stress increases promoted by previous earthquakes. The results confirm interactive relationships between large events. By considering time-dependency, the seismicity rate evolution was estimated using the rate-and-state friction model. The results indicated that a high seismic rate will persist at least until the end of 2012. Short-term probabilistic seismic hazard assessments were also applied in terms of the probability of strong ground motion. Using this application, a sudden jump in seismic hazards in southern Taiwan was accompanied by each large earthquake. At the end of 2012 it is expected that hazards will return to a background level. Our results may be valuable in the future to decision-makers and public officials engaged in seismic hazard mitigation.

Chan, C.; Wu, Y.

2012-12-01