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1.
Afr. j. health prof. educ ; 14(4): 2-12, 2023. tables, figures
Article in English | AIM (Africa) | ID: biblio-1425583

ABSTRACT

Background. University-based research capacity development (RCD) mechanisms tend to focus on staff and postgraduate students, with few structures targeted at undergraduate students. Support for undergraduate research must be tailored to the unique requirements of research at this level, while maintaining links with relevant structures in both the RCD and teaching and learning domains. Objective. To conduct a process evaluation of the Undergraduate Research Office (URO) in the Faculty of Medicine and Health Sciences at Stellenbosch University, South Africa, using RCD and characteristics of excellence in undergraduate research criteria as benchmarks. Methods. A process evaluation of URO's first 6 years was conducted using a logic model of URO's inputs, activities, and outputs. Through a retrospective document review, a descriptive analysis of URO's inputs and activities (narrative) and URO's outputs (statistical) was conducted. Results. Following a description of inputs and activities, results present URO's outputs as a measure of the uptake of these activities. From 2015 to 2020, 259 undergraduate research projects were completed. Research consultations, workshops and undergraduate presentations at the faculty's Annual Academic Day have more than doubled since URO's inception. The Undergraduate Research Ethics Committee has reviewed 243 ethics applications since 2015, with a 1 - 2-week turnaround time. A total of 134 funding applications worth ZAR705 986 have been awarded for research project, conference presentation and publication costs. Conclusion. Results show the potential impact of a formal undergraduate research support entity on the undergraduate research outputs of a Faculty of Medicine and Health Sciences. This article highlights elements for success for formal undergraduate research support, and identifies gaps going forward.


Subject(s)
Education, Medical, Undergraduate , Health Sciences , National Academies of Science, Engineering, and Medicine, U.S., Health and Medicine Division , Delivery of Health Care
2.
Science ; 373(6551): 198-204, 2021 07 09.
Article in English | MEDLINE | ID: mdl-34244410

ABSTRACT

Mars' sedimentary rock record preserves information on geological (and potential astrobiological) processes that occurred on the planet billions of years ago. The Curiosity rover is exploring the lower reaches of Mount Sharp, in Gale crater on Mars. A traverse from Vera Rubin ridge to Glen Torridon has allowed Curiosity to examine a lateral transect of rock strata laid down in a martian lake ~3.5 billion years ago. We report spatial differences in the mineralogy of time-equivalent sedimentary rocks <400 meters apart. These differences indicate localized infiltration of silica-poor brines, generated during deposition of overlying magnesium sulfate-bearing strata. We propose that destabilization of silicate minerals driven by silica-poor brines (rarely observed on Earth) was widespread on ancient Mars, because sulfate deposits are globally distributed.

3.
J Geophys Res Planets ; 125(8): e2019JE006295, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32999799

ABSTRACT

The Curiosity rover's exploration of rocks and soils in Gale crater has provided diverse geochemical and mineralogical data sets, underscoring the complex geological history of the region. We report the crystalline, clay mineral, and amorphous phase distributions of four Gale crater rocks from an 80-m stratigraphic interval. The mineralogy of the four samples is strongly influenced by aqueous alteration processes, including variations in water chemistries, redox, pH, and temperature. Localized hydrothermal events are evidenced by gray hematite and maturation of amorphous SiO2 to opal-CT. Low-temperature diagenetic events are associated with fluctuating lake levels, evaporative events, and groundwater infiltration. Among all mudstones analyzed in Gale crater, the diversity in diagenetic processes is primarily captured by the mineralogy and X-ray amorphous chemistry of the drilled rocks. Variations indicate a transition from magnetite to hematite and an increase in matrix-associated sulfates suggesting intensifying influence from oxic, diagenetic fluids upsection. Furthermore, diagenetic fluid pathways are shown to be strongly affected by unconformities and sedimentary transitions, as evidenced by the intensity of alteration inferred from the mineralogy of sediments sampled adjacent to stratigraphic contacts.

4.
BMC Public Health ; 20(1): 1383, 2020 Sep 10.
Article in English | MEDLINE | ID: mdl-32912223

ABSTRACT

BACKGROUND: Very little has been researched about the efficacy, effectiveness, feasibility, sustainability and impact of food-based approaches on the diets and nutritional status of populations at risk of hunger and food insecurity. This study contributes knowledge about the impact of food-based approaches on the diets of populations at risk of hunger and food insecurity in four of the poorest rural communities in South Africa. The study investigated the consumption and production patterns of rural households (278 in summer and 280 in winter) in four sites in the poorest municipalities in South Africa. METHODS: A multistage stratified random sampling technique was applied to identify the communities and sample households for the quantitative survey and qualitative assessments. Qualitative and quantitative data were collected between 2013 and 2015 through focus group discussions (FGDs), key informant interviews and the two-round panel survey to cover both the summer and winter seasons at each site. RESULTS: Home gardening led to a significant positive increase in the consumption of white roots and tubers, dark green leafy vegetables, orange-coloured fruit and other fruit in the 24 h prior to the survey. Participation in a community garden led to significant increases in the consumption of dark green leafy vegetables and other vegetables. School gardening did not demonstrate any statistical relationships with the consumption of foods from the crop-related food groups. Crop production improved dietary diversity. Selling produce and irrigation showed a stronger improvement in dietary diversity. Seasonality affected the availability of fresh fruit and vegetables for home consumption in winter. CONCLUSIONS: Producing beyond that solely for home consumption has greater benefits for dietary diversity and a consumption-smoothing effect during the post-harvest period. Politicians and the scientific community should recognise the role that household and small-scale crop production plays in supporting household consumption and the provision of essential micronutrients despite constraints and disincentives. Production and education programmes should focus on strengthening existing good consumption patterns and promoting the consumption of foods that can improve dietary diversity.


Subject(s)
Nutritional Status , Rural Population , Diet , Food Supply , Humans , South Africa , Vegetables
5.
Astrobiology ; 20(6): 785-814, 2020 06.
Article in English | MEDLINE | ID: mdl-32466662

ABSTRACT

On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.


Subject(s)
Exobiology , Extraterrestrial Environment , Mars , Caves , Computer Simulation , Ice , Space Flight
6.
G3 (Bethesda) ; 7(7): 2185-2193, 2017 07 05.
Article in English | MEDLINE | ID: mdl-28546386

ABSTRACT

In the framework of a gene flow assessment, we investigated the natural hybridization rate between Gossypium hirsutum (AADD genome) and G. herbaceum (AA genome). The latter species, a diploid progenitor of G. hirsutum, is spontaneously present in South Africa. Reciprocal crosses were performed without emasculation between G. herbaceum and G. hirsutum Neither examination of the morphological characteristics nor flow cytometry analysis of the 335 plants resulting from the G. hirsutum × G. herbaceum cross showed any hybrid features. Of the 148 plants produced from the G. herbaceum × G. hirsutum cross, three showed a hybrid phenotype, and their hybrid status was confirmed by SSR markers. Analysis of DNA content by flow cytometry and morphological traits clearly showed that two of these plants were triploid (AAD). The third plant had a flow cytometry DNA content slightly higher than G. hirsutum In addition, its morphological characteristics (plant architecture, presence and size of petal spots, leaf shape) led us to conclude that this plant was AAAD thus resulting from fertilization with an unreduced AA gamete of the female G. herbaceum parent. Fluorescent In Situ Hybridization (FISH) and meiotic behavior confirmed this hypothesis. To the best of our knowledge, this is the first description of such gametes in G. herbaceum, and it opens new avenues in breeding programs. Furthermore, this plant material could provide a useful tool for studying the expression of genes duplicated in the A and D cotton genome.


Subject(s)
Chimera/genetics , Diploidy , Gene Flow , Genome, Plant , Germ Cells, Plant , Gossypium/genetics , DNA, Plant/genetics , South Africa
7.
Science ; 353(6294): 55-8, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27365444

ABSTRACT

Wind blowing over sand on Earth produces decimeter-wavelength ripples and hundred-meter- to kilometer-wavelength dunes: bedforms of two distinct size modes. Observations from the Mars Science Laboratory Curiosity rover and the Mars Reconnaissance Orbiter reveal that Mars hosts a third stable wind-driven bedform, with meter-scale wavelengths. These bedforms are spatially uniform in size and typically have asymmetric profiles with angle-of-repose lee slopes and sinuous crest lines, making them unlike terrestrial wind ripples. Rather, these structures resemble fluid-drag ripples, which on Earth include water-worked current ripples, but on Mars instead form by wind because of the higher kinematic viscosity of the low-density atmosphere. A reevaluation of the wind-deposited strata in the Burns formation (about 3.7 billion years old or younger) identifies potential wind-drag ripple stratification formed under a thin atmosphere.

8.
S. Afr. med. j. (Online) ; 106(7): 724-729, 2016.
Article in English | AIM (Africa) | ID: biblio-1271119

ABSTRACT

BACKGROUND:The prevalence of cardiovascular disease is projected to be 38.7% for the USA in 2020; including coronary heart disease at 8.6% and stroke at 3.6%. In South Africa (SA); premature deaths due to heart and blood vessel diseases in people of working age (35 - 64 years) have been predicted to increase by 41% between 2007 and 2030; with enormous negative economic impact. Atherosclerosis underlies much of the pathogenesis; which involves risk factors including dyslipidaemia. Secondary dyslipidaemia associated with diabetes mellitus; hypothyroidism; chronic renal disease; cholestasis; nephrotic syndrome; alcohol excess; drugs such as thiazide diuretics and antiretroviral agents may respond to treatment of underlying causes; but residual dyslipidaemia may in such cases be due to primary disorders of metabolism. Primary dyslipidaemias are uncommon and to a large extent underdiagnosed; especially in the black population of SA; reflecting a lack of clinical and laboratory awareness or expertise. Specific diagnoses enable effective intervention in the patients as well as the families.OBJECTIVE:To assess the burden and prevalence of dyslipidaemia in the SA black population at Dr George Mukhari Hospital in the north region of Gauteng.METHOD:A retrospective data analysis of 12-month lipid profiles comprising triglyceride (TG); total cholesterol (TC); high-density lipoprotein cholesterol and directly measured low-density lipoprotein (LDL) cholesterol (LDLC).RESULTS:There were 24 656 requests for 6 348 patients. The lipid cut-off levels were somewhat arbitrary but were based on the commonly used decision-making levels in the treatment guidelines. Severe hypercholesterolaemia (etgt;7 mmol/L) was seen in 299 (4.7%) patients and extreme hypercholesterolaemia (etgt;12 mmol/L) was seen in 30 (0.5%) patients. LDLC (etgt;5 mmol/L) occurred in 80 (1.3%) patients and etgt;10 mmol/L in 19 (0.3%) patients. A predominant triglyceride problem was seen in 578 (9.1%) patients with TG (etgt;2 mmol/L) and TC (etlt;5 mmol/L); whereas moderate hypertriglyceridaemia (etgt;5 mmol/L) was present in 113 (1.8%) patients; and more severe hypertriglyceridaemia (etgt;10 mmol/L) in 10 (0.2%). TC (etgt;5 mmol/L) with LDL (etgt;3 mmol/L) but TG in the normal range was seen in 369 (5.8%) patients; indicating a cholesterol-predominant problem. In contrast; LDLC (etgt;3 mmol/L) and TG (etgt;1.7 mmol/L) was seen in 249 (3.87%) representing mixed hyperlipidaemia. Paediatric patients with severe dyslipidaemia mostly suffered from nephrotic syndrome.CONCLUSION:A significant burden and a high prevalence of dyslipidaemias were present in adults in whom a monogenic disorder should be considered. The extent and severity of dyslipidaemia justify a special clinic and laboratory to ensure accurate diagnosis with effective intervention for patients and their families


Subject(s)
Black People , Dyslipidemias/diagnosis , Dyslipidemias/epidemiology , Dyslipidemias/etiology , Tertiary Care Centers
9.
J Geophys Res Planets ; 120(3): 495-514, 2015 Mar.
Article in English | MEDLINE | ID: mdl-26690960

ABSTRACT

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles. KEY POINTS: First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

10.
Scott Med J ; 60(4): 164-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26403572

ABSTRACT

BACKGROUND: A key skill for a practising clinician is being able to do research, understand the statistical analyses and interpret results in the medical literature. Basic statistics has become essential within medical education, but when, what and in which format is uncertain. METHODS: To inform curriculum design/development we undertook a quantitative survey of fifth year medical students and followed them up with a series of focus groups to obtain their opinions as to what statistics teaching they want, when and how. RESULTS: A total of 145 students undertook the survey and five focus groups were held with between 3 and 9 participants each. Previous statistical training varied and students recognised their knowledge was inadequate and keen to see additional training implemented. Students were aware of the importance of statistics to their future careers, but apprehensive about learning. Face-to-face teaching supported by online resources was popular. Focus groups indicated the need for statistical training early in their degree and highlighted their lack of confidence and inconsistencies in support. CONCLUSION: The study found that the students see the importance of statistics training in the medical curriculum but that timing and mode of delivery are key. The findings have informed the design of a new course to be implemented in the third undergraduate year. Teaching will be based around published studies aiming to equip students with the basics required with additional resources available through a virtual learning environment.


Subject(s)
Curriculum , Education, Medical, Undergraduate/standards , Research/education , Statistics as Topic/education , Students, Medical , Attitude of Health Personnel , Faculty, Medical , Focus Groups , Humans , Scotland , Students, Medical/psychology , Surveys and Questionnaires , Teaching
11.
Geobiology ; 12(6): 557-74, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25312537

ABSTRACT

Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate observed isotopic signatures in ancient sedimentary strata to conditions in the overlying water column at the time of deposition and associated inferences about carbon cycling.


Subject(s)
Carbon Isotopes/analysis , Carbonates/chemistry , Cyanobacteria/metabolism , Photosynthesis , Chemical Precipitation , Salinity , Sulfates/chemistry
12.
Science ; 343(6169): 1243480, 2014 Jan 24.
Article in English | MEDLINE | ID: mdl-24324271

ABSTRACT

Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, iron sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 angstroms, indicating little interlayer hydration. The Cumberland smectite has basal spacing at both ~13.2 and ~10 angstroms. The larger spacing suggests a partially chloritized interlayer or interlayer magnesium or calcium facilitating H2O retention. Basaltic minerals in the mudstone are similar to those in nearby eolian deposits. However, the mudstone has far less Fe-forsterite, possibly lost with formation of smectite plus magnetite. Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time.


Subject(s)
Extraterrestrial Environment/chemistry , Geologic Sediments/chemistry , Mars , Minerals/chemistry , Ferrosoferric Oxide/analysis , Ferrosoferric Oxide/chemistry , Geologic Sediments/analysis , Minerals/analysis , Silicates/analysis , Silicates/chemistry , Silicon Compounds/analysis , Silicon Compounds/chemistry
13.
Science ; 343(6169): 1244734, 2014 Jan 24.
Article in English | MEDLINE | ID: mdl-24324274

ABSTRACT

Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.


Subject(s)
Exobiology , Extraterrestrial Environment/chemistry , Geologic Sediments/chemistry , Mars , Bays , Calcium Sulfate/analysis , Calcium Sulfate/chemistry , Chlorine/analysis , Chlorine/chemistry , Ferrosoferric Oxide/analysis , Ferrosoferric Oxide/chemistry , Halogens/analysis , Halogens/chemistry , Hydrogen-Ion Concentration , Iron/analysis , Iron/chemistry , Magnesium/analysis , Magnesium/chemistry , Silicates/analysis , Silicates/chemistry , Water/chemistry
14.
Science ; 343(6169): 1245267, 2014 Jan 24.
Article in English | MEDLINE | ID: mdl-24324276

ABSTRACT

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.


Subject(s)
Exobiology , Extraterrestrial Environment/chemistry , Hydrocarbons, Chlorinated/analysis , Mars , Volatile Organic Compounds/analysis , Bays , Carbon Dioxide/analysis , Carbon Dioxide/chemistry , Geologic Sediments/analysis , Geologic Sediments/chemistry , Oxygen/analysis , Oxygen/chemistry , Sulfides/analysis , Sulfides/chemistry , Water/analysis , Water/chemistry
15.
Geobiology ; 12(1): 62-82, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24325308

ABSTRACT

Modern evaporitic microbial ecosystems are important analogs for understanding the record of earliest life on Earth. Although mineral-depositing shallow-marine environments were prevalent during the Precambrian, few such environments are now available today for study. We investigated the molecular and lipid biomarker composition of an endoevaporitic gypsarenite microbial mat community in Guerrero Negro, Mexico. The 16S ribosomal RNA gene-based phylogenetic analyses of this mat corroborate prior observations indicating that characteristic layered microbial communities colonize gypsum deposits world-wide despite considerable textural and morphological variability. Membrane fatty acid analysis of the surface tan/orange and lower green mat crust layers indicated cell densities of 1.6 × 10(9) and 4.2 × 10(9)  cells cm(-3) , respectively. Several biomarker fatty acids, ∆7,10-hexadecadienoic, iso-heptadecenoic, 10-methylhexadecanoic, and a ∆12-methyloctadecenoic, correlated well with distributions of Euhalothece, Stenotrophomonas, Desulfohalobium, and Rhodobacterales, respectively, revealed by the phylogenetic analyses. Chlorophyll (Chl) a and cyanobacterial phylotypes were present at all depths in the mat. Bacteriochlorophyl (Bchl) a and Bchl c were first detected in the oxic-anoxic transition zone and increased with depth. A series of monomethylalkanes (MMA), 8-methylhexadecane, 8-methylheptadecane, and 9-methyloctadecane were present in the surface crust but increased in abundance in the lower anoxic layers. The MMA structures are similar to those identified previously in cultures of the marine Chloroflexus-like organism 'Candidatus Chlorothrix halophila' gen. nov., sp. nov., and may represent the Bchl c community. Novel 3-methylhopanoids were identified in cultures of marine purple non-sulfur bacteria and serve as a probable biomarker for this group in the lower anoxic purple and olive-black layers. Together microbial culture and environmental analyses support novel sources for lipid biomarkers in gypsum crust mats.


Subject(s)
Bacteria/classification , Biomarkers/analysis , Calcium Sulfate/chemistry , DNA/analysis , Geologic Sediments/microbiology , Lipids/analysis , Bacteria/chemistry , Bacteria/genetics , DNA/genetics , Mexico , Molecular Sequence Data , Sequence Analysis, DNA
16.
Science ; 341(6153): 1239505, 2013 Sep 27.
Article in English | MEDLINE | ID: mdl-24072928

ABSTRACT

The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.

17.
S Afr Med J ; 102(4): 228-33, 2012 Mar 07.
Article in English | MEDLINE | ID: mdl-22464504

ABSTRACT

Building the skills for doing, managing and delivering health research is essential for every country's development. Yet, human resources for health research (HRHR) are seldom considered in Africa and elsewhere. Africa's health research capacity has grown considerably, with potential to increase this growth. However, a systemic way of defining, co-ordinating and growing the HRHR needed to support health systems development is missing. Reviewing the status of HRHR in Africa, we assert that it consists of uncoordinated, small-scale activities, primarily driven from outside Africa. We present examples of ongoing HRHR capacity building initiatives in Africa. There is no overarching framework, strategy or body for African countries to optimise research support and capacity in HRHR. A simple model is presented to help countries plan and strategise for a comprehensive approach to research capacity strengthening. Everyone engaged with global, regional and national research for health enterprises must proactively address human resource planning for health research in Africa. Unless this is made explicit in global and national agendas, Africa will remain only an interested spectator in the decisions, prioritisation, funding allocations, conduct and interpretation, and in the institutional, economic and social benefits of health research, rather than owning and driving its own health research agendas.


Subject(s)
Capacity Building/organization & administration , Health Services Research , Personnel Management , Program Development , Africa , Health Resources , Health Services Needs and Demand , Health Services Research/economics , Health Services Research/organization & administration , Humans , Needs Assessment , Personnel Management/methods , Workforce
18.
S. Afr. j. clin. nutr. (Online) ; 23(1): 40-45, 2010.
Article in English | AIM (Africa) | ID: biblio-1270501

ABSTRACT

The Baby-Friendly Hospital Initiative (BFHI) is a global effort to improve the role of maternity services and to enable mothers to breastfeed their infants; thus ensuring the best start in life for their infants. The foundation for the BFHI is the Ten Steps to Successful Breastfeeding (BF). It has been shown; however; that the selective implementation of only some of the steps may be ineffective and discouraging to successful BF practices. An initial study was therefore conducted to assess the extent of the implementation of the Ten Steps in both public and private maternity facilities. Poor performance for some steps led to a follow-up study to investigate the knowledge and attitudes of health care workers (HCWs) and mothers alike and to evaluate the exclusive BF (EBF) practices of mothers attending private BF clinics. Both studies followed descriptive; cross-sectional designs and were set in the Cape Metropole in the Western Cape. Twenty-six maternity facilities participated in the initial study; for which observation lists were completed and verified by interviewer-administered questionnaires to both HCWs and mothers. Eighteen private BF clinics participated in the follow-up study; which included observations and interviewer-administered questionnaires to 25 HCWs and 64 mothers. During the initial study; lower mean scores were noted for Steps 1; 2; 6 and 10. The overall implementation of the Ten Steps was average. The findings highlighted the importance of the establishment and implementation of BF policies; of appropriate and continuous BF training and better referral systems to ensure initiation and establishment of early BF; EBF practices and support on an ongoing basis to ensure the best start in life for infants


Subject(s)
Breast Feeding , Health Facilities , Infant
19.
Mult Scler ; 15(6): 759-62, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19435752

ABSTRACT

BACKGROUND: Reports on fatty acids levels in multiple sclerosis remain inconclusive. OBJECTIVE: To determine the erythrocyte membrane fatty acid levels in multiple sclerosis patients and correlate with Kurtzke Expanded Disability Status Scale. METHODS: Fatty acid composition of 31 multiple sclerosis and 30 control individuals were measured by gas chromatography. RESULTS: The membrane phosphatidylcholine C20:4n - 6 concentration was lower in the multiple sclerosis patients when compared to that of the control group, P = 0.04 and it correlated inversely with the EDSS and FSS. CONCLUSION: Decrease in C20:4n - 6 in the erythrocyte membrane could be an indication of depleted plasma stores, and a reflection of disease severity.


Subject(s)
Disability Evaluation , Erythrocyte Membrane/metabolism , Fatty Acids/metabolism , Multiple Sclerosis, Chronic Progressive/metabolism , Multiple Sclerosis, Relapsing-Remitting/metabolism , Chromatography, Gas , Female , Humans , Phosphatidylcholines/metabolism , Severity of Illness Index
20.
Nature ; 454(7202): 305-9, 2008 Jul 17.
Article in English | MEDLINE | ID: mdl-18633411

ABSTRACT

Phyllosilicates, a class of hydrous mineral first definitively identified on Mars by the OMEGA (Observatoire pour la Mineralogie, L'Eau, les Glaces et l'Activitié) instrument, preserve a record of the interaction of water with rocks on Mars. Global mapping showed that phyllosilicates are widespread but are apparently restricted to ancient terrains and a relatively narrow range of mineralogy (Fe/Mg and Al smectite clays). This was interpreted to indicate that phyllosilicate formation occurred during the Noachian (the earliest geological era of Mars), and that the conditions necessary for phyllosilicate formation (moderate to high pH and high water activity) were specific to surface environments during the earliest era of Mars's history. Here we report results from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of phyllosilicate-rich regions. We expand the diversity of phyllosilicate mineralogy with the identification of kaolinite, chlorite and illite or muscovite, and a new class of hydrated silicate (hydrated silica). We observe diverse Fe/Mg-OH phyllosilicates and find that smectites such as nontronite and saponite are the most common, but chlorites are also present in some locations. Stratigraphic relationships in the Nili Fossae region show olivine-rich materials overlying phyllosilicate-bearing units, indicating the cessation of aqueous alteration before emplacement of the olivine-bearing unit. Hundreds of detections of Fe/Mg phyllosilicate in rims, ejecta and central peaks of craters in the southern highland Noachian cratered terrain indicate excavation of altered crust from depth. We also find phyllosilicate in sedimentary deposits clearly laid by water. These results point to a rich diversity of Noachian environments conducive to habitability.

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