Clay mineralogy of South Atlantic surface sediments

Surface samples, mostly from abyssal sediments of the South Atlantic, from parts of the equatorial Atlantic, and of the Antarctic Ocean, were investigated for clay content and clay mineral composition. Maps of relative clay mineral content were compiled, which improve previous maps by showing more details, especially at high latitudes. Large-scale relations regarding the origin and transport paths of detrital clay are revealed. High smectite concentrations are observed in abyssal regions, primarily derived from southernmost South America and from minor sources in Southwest Africa. Near submarine volcanoes of the Antarctic Ocean (South Sandwich, Bouvet Island) smectite contents exhibit distinct maxima, which is ascribed to the weathering of altered basalts and volcanic glasses. The illite distribution can be subdivided into five major zones including two maxima revealing both South African and Antarctic sources. A particularly high amount of Mg- and Fe-rich illites are observed close to East Antarctica. They are derived from biotite-bearing crystalline rocks and transported to the west by the East Antarctic Coastal Current. Chiorite and well-crystallized dioctaedral illite are typical minerals enriched within the Subantarctic and Polarfrontal-Zone but of minor importance off East Antarctica. Kaolinite dominates the clay mineral assemblage at low latitudes, where the continental source rocks (West Africa, Brazil) are mainly affected by intensive chemical weathering. Surprisingly, a slight increase of kaolinite is observed in the Enderby Basin and near the Filchner-Ronne Ice shelf. The investigated area can be subdivided into ten, large-scale clay facies zones with characteristic possible source regions and transport paths. Clay mineral assemblages of the largest part of the South Atlantic, especially of the western basins are dominated by chlorite and illite derived from the Antarctic Peninsula and southernmost South America and supported by advection within the Circumantarctic Deep Water flow. In contrast, the East Antarctic provinces are relatively small. Assemblages of the eastern basins north of 30°S are strongly influenced by African sources, controlled by weathering regimes on land and by a complex interaction of wind, river and deep ocean transport. The strong gradient in clay mineral composition at the Brazilian slope indicate a relatively low contribution of tropically derived assemblages to the western basins.

Revisiting the Late Jurassic-Early Cretaceous of the NW South Iberian Basin: new ages and sedimentary environments

The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is also interpreted here as rapid. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valangian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.

Upper-Pleistocene terrace deposits in Mediterranean climate: geomorphological and source-rock control on mineral and geochemical signatures (Betic Cordillera, SE Spain)

Mineral and chemical composition of alluvial Upper-Pleistocene deposits from the Alto Guadalquivir Basin (SE Spain) were studied as a tool to identify sedimentary and geomorphological processes controlling its formation. Sediments located upstream, in the north-eastern sector of the basin, are rich in dolomite, illite, MgO and KB2BO. Downstream, sediments at the sequence base are enriched in calcite, smectite and CaO, whereas the upper sediments have similar features to those from upstream. Elevated rare-earth elements (REE) values can be related to low carbonate content in the sediments and the increase of silicate material produced and concentrated during soil formation processes in the neighbouring source areas. Two mineralogical and geochemical signatures related to different sediment source areas were identified. Basal levels were deposited during a predominantly erosive initial stage, and are mainly composed of calcite and smectite materials enriched in REE coming from Neogene marls and limestones. Then the deposition of the upper levels of the alluvial sequences, made of dolomite and illitic materials depleted in REE coming from the surrounding Sierra de Cazorla area took place during a less erosive later stage of the fluvial system. Such modification was responsible of the change in the mineralogical and geochemical composition of the alluvial sediments.

Genomic and archaeological evidence suggest a dual origin of domestic dogs

The geographic and temporal origins of dogs remain controversial. We generated genetic sequences from 59 ancient dogs and a complete (28x) genome of a late Neolithic dog (dated to ~4800 calendar years before the present) from Ireland. Our analyses revealed a deep split separating modern East Asian and Western Eurasian dogs. Surprisingly, the date of this divergence (~14,000 to 6400 years ago) occurs commensurate with, or several millennia after, the first appearance of dogs in Europe and East Asia. Additional analyses of ancient and modern mitochondrial DNA revealed a sharp discontinuity in haplotype frequencies in Europe. Combined, these results suggest that dogs may have been domesticated independently in Eastern and Western Eurasia from distinct wolf populations. East Eurasian dogs were then possibly transported to Europe with people, where they partially replaced European Paleolithic dogs.

Digitally Mediated Political Participation: Understanding the Democratic Impact of Internet Diffusion in the Asian Media Systems

Thesis (Ph.D.)--University of Washington, 2016-08

Household language, residential segregation and social mobility: continuity and change in eThekwini, South Africa

This article uses South African census data for 1996, 2001 and 2011 to explore the relationship between language and social mobility in the metropolitan region of eThekwini (including what was previously known as Durban). We focus particular attention on variables selected to shed light on residential segregation and social mobility, such as education level, income, race and in-migration. Data on adults at ward level (using 2011 ward boundaries) in eThekwini is used to develop a comparative spatial context for this analysis. Our main finding is that English appears in eThekwini to be the household language of the social elite as well as the language of upward mobility and empowerment.

The impact of household size on poverty: An analysis of various low-income townships in the Northern Free State region, South Africa

Poverty is a multi-dimensional socio-economic problem in most sub-Saharan African countries. The purpose of this study is to analyse the relationship between household size and poverty in low-income communities. The Northern Free State region in South Africa was selected as the study region. A sample of approximately 2 900 households was randomly selected within 12 poor communities in the region. A poverty line was calculated and 74% of all households were found to live below the poverty line. The Pearson’s chi-square test indicated a positive relationship between household size and poverty in eleven of the twelve low-income communities. Households below the poverty line presented larger households than those households above the poverty line. This finding is in contradiction with some findings in other African countries due to the fact that South Africa has higher levels of modernisation with less access to land for subsistence farming. Effective provision of basic needs, community facilities and access to assets such as land could assist poor households with better quality of life. Poor households also need to be granted access to economic opportunities, while also receiving adult education regarding financial management and reproductive health.

The young, educated, minorities and the poor move out from south central Ethiopia

High population growth fragmented rural landholdings leading to low harvests and crop yields per acre per annum creating surplus labour that may resort to migration as a coping mechanism in least developing countries including Ethiopia. The main aim of the study is to assess trends and differentials of out-migration in south central Ethiopia. The Butajira demographic surveillance system database from 1987 to 2008 was used to conduct event history analysis. There were 3.97 out-migrations per 100 person years. Probability of out-migration was higher among males, teenagers, the youth, completed primary and secondary plus education; not in marital union; Christians, urbanites; lived in rented and owed house compared to their respective counterparts. The higher chances of out-migration among these groups may have social and economic significance.

Seasonal abundance and molecular identification of West Nile virus vectors, Culex pipens and Culex quinquefasciatus (diptera: culicidae) in Abeokuta, South-West, Nigeria.

Background: West Nile virus (WNV) infection, is an arbovirus infection with high morbidity and mortality, the vector responsible for both human and animal transmission is Culex pipens complex. Objective: To determine the species distribution and seasonal abundance of Culex pipens and Culex quinquefasciatus mosquitoes in Abeokuta, Nigeria. Methods: Mosquitoes belonging to the Culex pipens complex were captured in three different locations located within Abeokuta Metropolis between March 2012 and January 2013. Individual species were identified using morphometric methods. Amplification of the Ace2 gene by PCR confirmed morphormetric identification of the mosquitoes. Results: A total of 751 mosquitoes were captured. Culex quinquefaciatus recorded the highest distribution of vectors with 56.6% and Culex pipens 43.4% (P > 0.05). Idi aba community recorded the highest distribution of mosquito vectors with 42.9% (n=322) and Culex quinqueaciatus was more abundantly distributed with 183 mosquitoes. Aro community recorded 32% (n=240) of captured mosquitoes with Culex quinquefaciatus having a higher level of abundance and lastly Kemta with a distribution of 25.1% (n=189). Conclusion: Results from this study show that potential vectors of WNV abound within Abeokuta, putting residents at high risk of West Nile infection. We advocate for introduction of routine testing of WNV in Abeokuta and Nigeria. Keywords:

Prevalence, severity and risk factors of allergic disorders among people in south India.

Background: Allergic disorders are not usually life-threatening conditions but they impair the person’s ability to function. It thus adversely affects the psychological wellbeing and quality of life. These implications of allergic disorders can be minimized if strategies are planned for its early identification followed by appropriate interventions. Objectives: To find out the prevalence and risk factors of allergic disorders. Methods: Data was collected by house to house survey among participants aged 18 years and above using a standardized allergy assessment questionnaire. Results: Mean age of the 400 participants was 42.8±14.7 years. Majority 105(26.2%) were in the age group 36 to 45 years. Majority were females 287(71.7%) and were house wives 217(54.2%). Majority of participants were of upper socio economic class 98(44.7%) out of 219 and majority were from urban areas 326(81.5%). The prevalence of allergy among participants was found to be 115(28.7%). Out of these 115, 37(32.2%) had possibility of allergy, 60(52.2%) had probability of allergy and the rest 18(15.6%) had very high likelihood for allergy. People residing in semi urban areas had increased risk of allergy (p=0.024) than those from urban areas. The prevalence of asthma was 30(7.5%) and skin allergy was 23(5.8%). Most common precipitating factors for allergy were dust exposure 103(25.8%) followed by seasonal changes 71(17.8%). Family history of allergy was associated with allergy among participants (p<0.001). Usage of firewood was associated with symptoms of respiratory allergy among participants (p=0.01). Conclusion: The study revealed some important determinants of allergic disorders which have important implications to frame appropriate prevention and health educational strategies.

Factors influencing the recommendation of the Human Papillomavirus vaccine by South African doctors working in a tertiary hospital.

Background: In South Africa, HPV vaccination programme has been incorporated recently in the school health system. Since doctors are the most trusted people regarding health issues in general, their knowledge and attitudes regarding HPV infections and vaccination are very important for HPV vaccine program nationally. Objective: The objective of this study was to investigate factors contributing to recommendation of HPV vaccines to the patients. Methods: This was a quantitative cross-sectional study conducted among 320 doctors, using a self-administered anonymous questionnaire. Results: All the doctors were aware of HPV and knew that HPV is transmitted sexually. Their overall level of knowledge regarding HPV infections and HPV vaccine was poor. But the majority intended to prescribe the vaccine to their patients. It was found that doctors who knew that HPV 6 and 11 are responsible for >90% of anogenital warts, their patients would comply with the counselling regarding HPV vaccination, and received sufficient information about HPV vaccination were 5.68, 4.91 and 4.46 times respectively more likely to recommend HPV vaccination to their patients, compared to their counterparts (p<0.05). Conclusion: There was a knowledge gap regarding HPV infection and HPV vaccine among the doctors.

The quality of rapid HIV testing in South Africa: an assessment of testers’ compliance.

Background: The aim of this study was to assess the quality of rapid HIV testing in South Africa. Method: A two-stage sampling procedure was used to select HCT sites in eight provinces of South Africa. The study employed both semi-structured interviews with HIV testers and observation of testing sessions as a means of data collection. In total, 63 HCT sites (one HIV tester per site) were included in the survey assessing qualification, training, testing practices and attitudes towards rapid tests. Quantitative data was analysed using descriptive statistics and qualitative data was content analysed. Results: Of the 63 HIV testers, 20.6% had a nursing qualification, 14.3% were professional counsellors, 58.7% were lay HIV counsellors and testers and 6.4% were from other professions. Most HIV testers (87.3%) had had a formal training in testing, which ranged between 10-14 days, while 6 (9.5%) had none. Findings revealed sub-standard practices in relation to testing. These were mainly related to non-adherence to testing algorithms, poor external quality control practices, poor handling and communication of discordant results. Conclusion: Quality of HIV rapid testing may be highly compromised through poor adherence to guidelines as observed in our study.

Five years retrospective cohort analysis of treatment outcomes of TB-HIV patients at a PEPFAR/DOTS Centre in South Eastern Nigeria.

Background: Human immunodeficiency virus (HIV) associated tuberculosis (TB) remains a major global public health challenge, with an estimated 1.4 million patients worldwide. Co-infection with HIV leads to challenges in the diagnosis and treatment of patients. Objectives: The aim of this study was to assess treatment outcomes of a cohort of smear positive TB-HIV co-infected patients over a five-year study period. Methods: A retrospective cohort study of 600 smear-positive tuberculosis patients registered at the chest unit of the University of Nigeria Teaching Hospital, Enugu from January 2008 to December 2012 was done. The data was analyzed using SPSS Version 17. Results: One hundred and three (17.2%) of the patients were co-infected with TB/HIV, while 398 (66.3%) and 99 (16.5%) were HIV negative and unknown respectively. Among the co-infected patients, 45(43.7%) were cured as against 222(55.8%) in the TBHIV negatives (Z=4.53, p=0.000, 95%CI= 0.12-0.34). Respectively in the TB-HIV co-infected and TB-HIV negative patients, treatment completed were 21(20.4%) and 71(17.8%) (Z=9.15, p=0.000, 95%= 0.4035-0.60); defaulted 19(18.5%) vs 70 (17.6%) (Z=9.29, p=0.000, 95%CI=0.42-0.60), died 10(9.7%) vs. 6(1.5%) (Z=1.22, p=0.224, 95%CI= -0.0286-0.1086), and failures were 1(0.9%) vs. 7(1.8%) (Z=2.48, p=0.013, 95%CI=0.04-0.10). Treatment success rate was lower in TB-HIV co-infected patients, 64.1% compared to TB-HIV negative patients with 73.6%. Also those that defaulted among the TB-HIV co-infected patients (18.5%) were higher than 17.6% among TB-HIV negative patients, a difference of 0.9%. Conclusion: Findings demonstrate that HIV co-infection affects TB treatment outcomes adversely. Treatment adherence, timely and sustained access to antiretroviral therapy for TB/HIV co-infected patients are important.

The revolving door of mental, neurological, and substance use disorders re-hospitalization in rural KwaZulu-Natal Province, South Africa.

Objective: Little is known about the extent of mental, neurological and substance-use (MNS) disorders re-hospitalization in South Africa. We examined the extent of one-year MNS re-hospitalization (MNS-R) in a rural South African primary health care facility (PHCF). Methods: We conducted a retrospective analysis of hospital administrative data from 10,525 adults discharged from a rural PHCF in KwaZulu-Natal Province, South Africa. Chi-squared tests were utilized to describe MNS-R within one year of an index hospital admission in individuals with MNS, with a sub-analysis also being conducted to describe schizophrenia re-hospitalization (S-R). Results: The prevalence of MNS and schizophrenia recorded at an index hospitalization was 5% and 1%, respectively. A total of 44/67 (66%) individuals with a diagnosis of MNS at the index hospitalization were classified as having MNS-R during oneyear follow-up period. Half of those diagnosed with schizophrenia at the index hospitalization (6/12 patients) were classified as having S-R during one-year follow-up period. There was a significant association between re-hospitalization outcomes (MNS-R and S-R) and MNS (p<0.01) or schizophrenia diagnosis (p<0.01) at index baseline hospitalization. Conclusion: The extent of MNS-R and S-R remains relatively high in rural South Africa, and needs further health systems strengthening to prevent revolving door occurrences.

Select toxic metals status of pregnant women with history of pregnancy complications in Benin City, South-South Nigeria.

Toxic metals are part of the most important groups of environmental pollutants that can bind to vital cellular components and interfere with their functions via inhalation, foods, water etc. The serum levels of toxic metals (lead, mercury, cadmium and arsenic) in pregnant women with history of pregnancy complications, pregnant women without history of pregnancy complication and non-pregnant women in Benin City, South – South Nigeria was investigated in this paper, with total of 135 healthy women comprising of 45 pregnant women with history of previous pregnancy complications, 45 pregnant women without history of pregnancy complications and 45 non-pregnant women without history of pregnancy complications (controls). Some demographic characteristics and 4ml of blood samples were obtained from each subject for the analysis of lead, mercury, cadmium and arsenic by standard methods. Pregnant women with history of pregnancy complications recorded a highly significant increase in the toxic metal (lead) mean value of 25.81μg/dl as against 23.70μg/dl for pregnant women without history of pregnancy complications and 11.23μg/dl for non-pregnant (control) women without history of pregnancy complications as well as significant increases in the mean values of other toxic metals (mercury, cadmium and arsenic) compared with controls (p<0.001). The selected toxic metals (Pb, Hg, Cd and As) may be involved in the development of pregnancy complications among pregnant women in Benin City, South– South Nigeria. Lead in particular may pose threat to mothers and fetuses as its mean values in the two groups of pregnant women were well above normal.