62 research outputs found
Ruggedness and child health outcomes : evidence from Burundi, Cameroon, Ethiopia and Nigeria
This paper examines the effect of terrain ruggedness on child stunting in Burundi, Cameroon, Ethiopia and Nigeria. Using a cross-section analysis with data from the Demographic and Health Surveys (DHS) and a measure that captures variation in the terrains of the countries, we find that the more difficult it is to traverse the terrain in Burundi, Cameroon and Nigeria, the higher the likelihood of child stunting. However, this association is not consistent for Ethiopia until we account for the Oromia region, which has the capital city Addis Ababa. These results remain robust with the inclusion of socio-economic factors related to child health (e.g. maternal health, maternal education and household income), demographic factors (e.g. gender of child), other geographical factors (e.g. rainfall patterns and malaria prevalence) and survey and region effects. The results suggest that there are complementary factors to geography that may contribute to poor child health outcomes, such as the quality of infrastructure and the ability to access healthcare services. Given that child health is a key development outcome, understanding such spatial variations associated with child health inequalities can assist in designing effective intervention programmes and allocating resources where they are most needed.http://wileyonlinelibrary.com/journal/sajehj2024EconomicsSDG-03:Good heatlh and well-bein
Comparing proportional compositions of geospatial technology-related programs at three universities
Today, graduates seek employment in a global marketplace, regardless of the country in which they studied.
Comparing academic programs helps students, academics and employers to make informed decisions about study
options, program offerings and the employment of recent graduates. In this study, we juxtapose geospatial technologyrelated
programs at three universities located in Europe, Africa and America. Initially, the authors contributed
information about these programs through a questionnaire comprising several open-ended questions about the origins
and development of the respective programs. Subsequently, the proportional thematic compositions of programs at the
three universities were compared. As expected, this study was not without challenges. From the outset, we struggled
with agreeing on terminology and semantics. Results of the study indicate that there is not a one-size-fits-all strategy for
establishing, shaping and sustaining such programs. Program composition is guided by many factors, including staff
expertise, university politics, legislation, attractiveness to students, technological developments, demands in the job
market and requirements set by a professional body. Some of these factors are strongly influenced by the local
(university) environment (e.g. staff expertise), others are of national relevance (e.g. legislation and a national
professional body), while some apply globally (e.g. technological developments). The study illustrated how a
comparison of proportional program composition can reveal significant differences and similarities that are not
obvious when only content is compared. The compositional differences naturally result in graduates with different
knowledge and skills that allow different career paths and meet different needs of the job market.http://www.sajg.org.za/index.php/sajgam2016Centre for Geoinformation ScienceGeography, Geoinformatics and Meteorolog
Effect of impervious surface area and vegetation changes on mean surface temperature over Tshwane metropolis, Gauteng Province, South Africa
The Tshwane Metropolis, Gauteng Province, South Africa, continues to experience rapid urbanization as a result of population growth. This has led to the conversion of natural lands into large man-made landscapes i.e., increase in impervious surfaces and a decrease in vegetative cover. This land use or land cover changes are also thought to affect the climate of the Tshwane metropolis as is evidenced by heat waves in 2013 and 2014. This paper describes how vegetation and impervious surface area (ISA) or built up areas were classified from Landsat 8 LCDM, 2013, and Landsat 7 ETM+, 2003 images using thematic spectral indices and mean surface temperatures derived from the thermal bands. The linear relationship between the two land cover types and surface temperature (LST) derived from the thermal bands was also examined. The results of this research reveal that the ISA increase has occurred due to urban sprawl and this has contributed to increase in surface temperature.The Applied Centre for Climate and Earth System Science (ACCESS) and University of Pretoria.http://www.sajg.org.za/index.php/sajgam2016Geography, Geoinformatics and Meteorolog
Effect of impervious surface area and vegetation changes on mean surface temperature over Tshwane metropolis, Gauteng Province, South Africa
The Tshwane Metropolis, Gauteng Province, South Africa, continues to experience rapid urbanization as a result of population growth. This has led to the conversion of natural lands into large man-made landscapes i.e., increase in impervious surfaces and a decrease in vegetative cover. This land use or land cover changes are also thought to affect the climate of the Tshwane metropolis as is evidenced by heat waves in 2013 and 2014. This paper describes how vegetation and impervious surface area (ISA) or built up areas were classified from Landsat 8 LCDM, 2013, and Landsat 7 ETM+, 2003 images using thematic spectral indices and mean surface temperatures derived from the thermal bands. The linear relationship between the two land cover types and surface temperature (LST) derived from the thermal bands was also examined. The results of this research reveal that the ISA increase has occurred due to urban sprawl and this has contributed to increase in surface temperature.The Applied Centre for Climate and Earth System Science (ACCESS) and University of Pretoria.http://www.sajg.org.za/index.php/sajgam2016Geography, Geoinformatics and Meteorolog
Differential segregation in a cell-cell contact interface: the dynamics of the immunological synapse
Receptor-ligand couples in the cell-cell contact interface between a T cell and an antigen-presenting cell form distinct geometric patterns and undergo spatial rearrangement within the contact interface. Spatial segregation of the antigen and adhesion receptors occurs within seconds of contact, central aggregation of the antigen receptor then occurring over 1-5 min. This structure, called the immunological synapse, is becoming a paradigm for localized signaling. However, the mechanisms driving its formation, in particular spatial segregation, are currently not understood. With a reaction diffusion model incorporating thermodynamics, elasticity, and reaction kinetics, we examine the hypothesis that differing bond lengths (extracellular domain size) is the driving force behind molecular segregation. We derive two key conditions necessary for segregation: a thermodynamic criterion on the effective bond elasticity and a requirement for the seeding/nucleation of domains. Domains have a minimum length scale and will only spontaneously coalesce/aggregate if the contact area is small or the membrane relaxation distance large. Otherwise, differential attachment of receptors to the cytoskeleton is required for central aggregation. Our analysis indicates that differential bond lengths have a significant effect on synapse dynamics, i.e., there is a significant contribution to the free energy of the interaction, suggesting that segregation by differential bond length is important in cell-cell contact interfaces and the immunological synapse
Polymerase chain reaction amplifying mycobacterial DNA from aspirates obtained by endoscopic ultrasound allows accurate diagnosis of mycobacterial disease in HIV-positive patients with abdominal lymphadenopathy
Abdominal lymphadopathy in Human Immunodeficiency Virus (HIV) infection
remains a diagnostic challenge. We performed a prospective cohort study
recruiting thirty-one symptomatic HIV+ patients with abdominal
lymphadenopathy assessing diagnostic yield of endoscopic ultrasound (EUS)
fine needle aspiration (FNA). Mean age was 38 years, 52% were female, mean
CD4 count and viral load were 124 cells/pl, and 4 log respectively. EUS
confirmed additional mediastinal nodes in 26 %. Porta- hepatis was the most
common abdominal site. EUS FNA was subjected to cytology, culture and
polymerase chain reaction (PCR) analysis. Mycobacterial infections were
confirmed in 67.7% and 31% had reactive lymphadenopathy. Cytology and
culture had low sensitivity whereas PCR identified 90% of mycobacterial
infections. Combining appearance of EUS FNA and cytology a diagnostic
algorithm was developed to indicate when analysis with PCR would be useful.
PCR performed on an EUS guided aspirate was highly accurate in confirming
mycobacterial disease and determining genotypic drug resistance.South African Gastroenterological Society (SAGES)/ Astra Zeneca Fellowship in Gastroenterology awarded to Schalk van der Merwehttp://www.journals.elsevier.com/ultrasound-in-medicine-and-biology/hb201
Mild Reductions in Mitochondrial NAD-Dependent Isocitrate Dehydrogenase Activity Result in Altered Nitrate Assimilation and Pigmentation But Do Not Impact Growth
Transgenic tomato (Solanum lycopersicum) plants were generated expressing a fragment of the mitochondrial NAD-dependent isocitrate dehydrogenase gene (SlIDH1) in the antisense orientation. The transgenic plants displayed a mild reduction in the activity of the target enzyme in the leaves but essentially no visible alteration in growth from the wild-type. Fruit size and yield were, however, reduced. These plants were characterized by relatively few changes in photosynthetic parameters, but they displayed a minor decrease in maximum photosynthetic efficiency (Fv/Fm). Furthermore, a clear reduction in flux through the tricarboxylic acid (TCA) cycle was observed in the transformants. Additionally, biochemical analyses revealed that the transgenic lines exhibited considerably altered metabolism, being characterized by slight decreases in the levels of amino acids, intermediates of the TCA cycle, photosynthetic pigments, starch, and NAD(P)H levels, but increased levels of nitrate and protein. Results from these studies show that even small changes in mitochondrial NAD-dependent isocitrate dehydrogenase activity lead to noticeable alterations in nitrate assimilation and suggest the presence of different strategies by which metabolism is reprogrammed to compensate for this deficiency
Agreement on endoscopic ultrasonography-guided tissue specimens: Comparing a 20-G fine-needle biopsy to a 25-G fine-needle aspiration needle among academic and non-academic pathologists
Background and Aim: A recently carried out randomized controlled trial showed the benefit of a novel 20-G fine-needle biopsy (FNB) over a 25-G fine-needle aspiration (FNA) needle. The current study evaluated the reproducibility of these findings among expert academic and non-academic pathologists. Methods: This study was a side-study of the ASPRO (ASpiration versus PROcore) study. Five centers retrieved 74 (59%) consecutive FNB and 51 (41%) FNA samples from the ASPRO study according to randomization; 64 (51%) pancreatic and 61 (49%) lymph node specimens. Samples were re-reviewed by five expert academic and five non-academic pathologists and rated in terms of sample quality and diagnosis. Ratings were compared between needles, expert academic and
Old stones' song: Use-wear experiments and analysis of the Oldowan quartz and quartzite assemblage from Kanjera South (Kenya)
Evidence of Oldowan tools by w2.6 million years ago (Ma) may signal a major adaptive shift in hominin
evolution. While tool-dependent butchery of large mammals was important by at least 2.0 Ma, the use of
artifacts for tasks other than faunal processing has been difficult to diagnose. Here we report on use-wear
analysis ofw2.0 Ma quartz and quartzite artifacts from Kanjera South, Kenya. A use-wear framework that
links processing of specific materials and tool motions to their resultant use-wear patterns was developed.
A blind test was then carried out to assess and improve the efficacy of this experimental use-wear
framework, which was then applied to the analysis of 62 Oldowan artifacts from Kanjera South. Usewear
on a total of 23 artifact edges was attributed to the processing of specific materials. Use-wear on
seven edges (30%) was attributed to animal tissue processing,corroborating zooarchaeological evidence
for butchery at the site. Use-wear on 16 edges (70%)was attributed to the processing of plant tissues,
including wood, grit-covered plant tissues that we interpret asunderground storage organs (USOs), and
stems of grass or sedges. These results expand our knowledge of the suite of behaviours carried out in the
vicinity of Kanjera South to include the processing of materials that would be ‘invisible’ using standard
archaeological methods. Wood cutting and scraping may represent the production and/or maintenance
of wooden tools. Use-wear related to USO processing extends the archaeological evidence for hominin acquisition and consumption of this resource by over 1.5 Ma. Cutting of grasses, sedges or reeds may be related to a subsistence task (e.g., grass seed harvesting, cutting out papyrus culm for consumption) and/or a non-subsistence related task (e.g., production of ‘twine,’ simple carrying devices, or bedding). These results highlight the adaptive significance of lithic technology for hominins at Kanjera
Horizontal versus familial transmission of Helicobacter pylori.
Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large population samples and to the extensive genetic diversity between isolates, the transmission and spread of H. pylori remain poorly understood. We studied the genetic relationships of H. pylori isolated from 52 individuals of two large families living in a rural community in South Africa and from 43 individuals of 11 families living in urban settings in the United Kingdom, the United States, Korea, and Colombia. A 3,406 bp multilocus sequence haplotype was determined for a total of 142 H. pylori isolates. Isolates were assigned to biogeographic populations, and recent transmission was measured as the occurrence of non-unique isolates, i.e., isolates whose sequences were identical to those of other isolates. Members of urban families were almost always infected with isolates from the biogeographic population that is common in their location. Non-unique isolates were frequent in urban families, consistent with familial transmission between parents and children or between siblings. In contrast, the diversity of H. pylori in the South African families was much more extensive, and four distinct biogeographic populations circulated in this area. Non-unique isolates were less frequent in South African families, and there was no significant correlation between kinship and similarity of H. pylori sequences. However, individuals who lived in the same household did have an increased probability of carrying the same non-unique isolates of H. pylori, independent of kinship. We conclude that patterns of spread of H. pylori under conditions of high prevalence, such as the rural South African families, differ from those in developed countries. Horizontal transmission occurs frequently between persons who do not belong to a core family, blurring the pattern of familial transmission that is typical of developed countries. Predominantly familial transmission in urban societies is likely a result of modern living conditions with good sanitation and where physical contact between persons outside the core family is limited and regulated by societal rules. The patterns observed in rural South African families may be representative of large parts of the developing world
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