Gestational diabetes mellitus in Africa: a systematic review.

BACKGROUND: Gestational diabetes mellitus (GDM) is any degree of impaired glucose tolerance first recognised during pregnancy. Most women with GDM revert to normal glucose metabolism after delivery of their babies; however, they are at risk of developing type 2 diabetes later in life as are their offspring. Determining a country's GDM prevalence can assist with policy guidelines regarding GDM screening and management, and can highlight areas requiring research. This systematic review assesses GDM prevalence in Africa. METHODS AND FINDINGS: Three electronic databases were searched without language restrictions; PubMed, Scopus and the Cochrane Library. Thirty-one search terms were searched. Eligible articles defined GDM, stated what GDM screening approaches were employed and reported GDM prevalence. The reporting quality and risk of bias within each study was assessed. The PRISMA guidelines for systematic reviews were followed. The literature search identified 466 unique records. Sixty full text articles were reviewed of which 14 were included in the systematic review. One abstract, for which the full text article could not be obtained, was also included. Information regarding GDM classification, screening methods and prevalence was obtained for six African countries; Ethiopia (n = 1), Morocco (n = 1), Mozambique (n = 1), Nigeria (n = 6), South Africa (n= 4) and Tanzania (n = 1). Prevalence figures ranged from 0% (Tanzania) to 13.9% (Nigeria) with some studies focussing on women with GDM risk factors. Most studies utilised the two hour 75 g oral glucose tolerance test and applied the World Health Organization's diagnostic criteria. CONCLUSIONS: Six countries, equating to 11% of the African continent, were represented in this systematic review. This indicates how little is known about GDM in Africa and highlights the need for further research. Considering the increasing public health burden of obesity and type 2 diabetes, it is essential that the extent of GDM is understood in Africa to allow for effective intervention programmes.This is the final published version of the article. It was originally published here: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0097871

A simple technique for quantifying apoptosis in 96-well plates

BACKGROUND: Analyzing apoptosis has been an integral component of many biological studies. However, currently available methods for quantifying apoptosis have various limitations including multiple, sometimes cell-damaging steps, the inability to quantify live, necrotic and apoptotic cells at the same time, and non-specific detection (i.e. "false positive"). To overcome the shortcomings of current methods that quantify apoptosis in vitro and to take advantage of the 96-well plate format, we present here a modified ethidium bromide and acridine orange (EB/AO) staining assay, which may be performed entirely in a 96-well plate. Our method combines the advantages of the 96-well format and the conventional EB/AO method for apoptotic quantification. RESULTS: We compared our method and the conventional EB/AO method for quantifying apoptosis of suspension cells (Jurkat) and adherent cells (A375) under normal growth and apoptosis-inducing conditions. We found that our new EB/AO method achieved quantification results comparable to those produced using the conventional EB/AO method for both suspension and adherent cells. CONCLUSION: By eliminating the detaching and washing steps, our method drastically reduces the time needed to perform the test, minimizes damage to adherent cells, and decreases the possibility of losing floating cells. Overall, our method is an improvement over the currently available techniques especially for adherent cells

Abdominal fat depots associated with insulin resistance and metabolic syndrome risk factors in black African young adults

Abstract Background Individuals of black African ethnicity tend to have less visceral adipose tissue (VAT) but more subcutaneous-abdominal adipose tissue (SCAT) than white Caucasians. However, it is unclear whether such distribution of abdominal fat is beneficial for metabolic disease risk in black individuals. Here we compared the associations between these specific abdominal fat depots, insulin sensitivity and metabolic syndrome risk. Methods A cross-sectional analysis of 76 black South African young adults (36 men; 40 women) aged 18–19 years participating in the Birth to Twenty Cohort Study had VAT and SCAT measured by MRI. The metabolic syndrome traits (blood pressure, lipid profile, fasting glucose and insulin) were measured and the values were combined into a metabolic syndrome risk score. Fasting glucose and insulin were used to derive the HOMA-index of insulin resistance (HOMA-IR). Results Compared to men, women had greater VAT (mean: 16.6 vs. 12.5 cm2) and SCAT (median 164.0 vs. 59.9 cm2). In men, SCAT (r = 0.50) was more strongly correlated to the metabolic syndrome score (MetS) than was VAT (r = 0.23), and was associated with both MetS (P = 0.001) and HOMA-IR (P = 0.001) after adjustment for VAT and total fat mass. In women, both abdominal fat compartments showed comparable positive correlations with MetS (r = 0.26 to 0.31), although these trends were weaker than in men. Conclusions In young black South African adults, SCAT appears to be more relevant than VAT to metabolic syndrome traits

Investigating student approaches to scenario-based assessments of systems thinking

The development of systems thinking is considered a critical skill set for addressing interdisciplinary problems. This skill set is particularly important in the field of engineering, where engineers are often tasked with solving socio-technical problems that often require knowledge beyond their original discipline and practice in unfamiliar contexts. However, existing assessments often fail to accurately measure teachable knowledge or skills that constitute systems thinking. To investigate this issue, we compared students’ performance on two previously and independently peer-reviewed scenario-based assessments for systems thinking: The Village of Abeesee and the Lake Urmia Vignette. Twenty undergraduate engineering students participated in a multi-phase case study utilizing think aloud protocols and semi-structured interview methods to elicit the approaches students took thinking across the two instruments and past experiences that they felt prepared them to solve these ill-structured problems. We found that the way a scenario is presented to students impacts their subsequent problem-solving approach, which complicates assessment of systems thinking. Additionally, students identified only limited opportunities for the development of ill-structured problem-solving skills necessary for systems thinking. Our findings inform future work on improving systems thinking assessments and emphasize the importance of more intentionally supplying opportunities for students to practice solving ill-structured problems throughout the curriculum

SN1997cy/GRB970514 - A New Piece in the GRB Puzzle?

We present observations of SN1997cy, a supernova discovered as part of the Mount Stromlo Abell Cluster SN Search, which does not easily fit into the traditional classification scheme for supernovae. This object's extraordinary optical properties and coincidence with GRB970514, a short duration gamma ray burst, suggest a second case, after SN1998bw/GRB980425, for a SN-GRB association. SN1997cy is among the most luminous SNe yet discovered and has a peculiar spectrum. We present evidence that SN1997cy ejected approximately 2 solar masses of 56Ni, supported by its late-time light curve, and FeII/[FeIII] lines in its spectrum, although it is possible that both these observations can be explained via circumstellar interaction. While SN1998bw and SN1997cy appear to be very different objects with respect to both their gamma ray and optical properties, SN1997cy and the optical transient associated with GRB970508 have roughly similar late-time optical behavior. This similarity may indicate that the late-time optical output of these two intrinsically bright transient events have a common physical process. Although the connection between GRB970514 and SN1997cy is suggestive, it is not conclusive. However, if this association is real, followup of short duration GRBs detected with BATSE or HETE2 should reveal objects similar to SN1997cy.Comment: 26 pages including 6 postscript figures and 3 tables. Submitted to ApJ. Re-calibrated photometry - objects are about 0.3mags brighter than in original versio

Melanocyte Mitogens Induce Both Melanocyte Chemokinesis and Chemotaxis

It is believed that during repigmentation of vitiligo, inactive melanocytes in the outer root sheath of the hair follicle become activated, proliferate, and migrate into the depigmented skin. However, the mechanisms controlling melanocyte migration remain to be elucidated. In this study, we investigated the effects of well-described melanocyte growth factors on melanocyte migration. Using time-lapse photography, we demonstrated that melanocyte chemokinetic movement was induced by basic fibroblast growth factor, stem cell factor, and endothelin-1, with the greatest effect noted using 100 nM endothelin-1. Similar results were reported previously with leukotriene C4. When surrounded by these stimuli, melanocytes moved in a random, nonlinear fashion and showed no desensitization at the concentrations studied.In Boyden chamber checkerboard analysis, basic fibroblast growth factor, leukotriene C4 and endothelin-1 were chemotactic. They produced directional migration and showed desensitization at higher concentrations. The greatest effect again was seen with 100 nM endothelin-1. Stem cell factor showed no effect in this assay system at the concentrations tested.The four melanocyte mitogens-leukotriene C4, endothelin-1, basic fibroblast growth factor, and stem cell factor-stimulate melanocyte migration, and this migration may be either chemokinetic (activated random movement) or chemotactic (requiring a gradient, directional, and showing desensitization), depending on the conditions used. We believe that these factors may be effective in stimulating vitiligo repigmentation by inducing proliferation and migration of hair-follicle outer-root-sheath melanocytes into the depigmented epidermis

Design, Optimization, and Evaluation of A1-2139 Compression Panel with Integral T-Stiffeners

A T-stiffened panel was designed and optimized for minimum mass subjected to constraints on buckling load, yielding, and crippling or local stiffener failure using a new analysis and design tool named EBF3PanelOpt. The panel was designed for a compression loading configuration, a realistic load case for a typical aircraft skin-stiffened panel. The panel was integrally machined from 2139 aluminum alloy plate and was tested in compression. The panel was loaded beyond buckling and strains and out-of-plane displacements were extracted from 36 strain gages and one linear variable displacement transducer. A digital photogrammetric system was used to obtain full field displacements and strains on the smooth (unstiffened) side of the panel. The experimental data were compared with the strains and out-of-plane deflections from a high-fidelity nonlinear finite element analysis

Implications of adopting the WHO 2006 Child Growth Standards: case study from urban South Africa, the Birth to Twenty cohort

Background: The World Health Organization (WHO) recently developed growth standards to overcome the limitations of previous references. Aim: The aim of this study was to compare the growth patterns of a cohort of children using the National Centre for Health Statistics (NCHS), the Centre for Disease Control (CDC), and WHO 2006 references/standards, and to evaluate the implications of adopting WHO standards. Subjects and methods: Using growth data (0 5 years) from the 1990 South African Birth to Twenty cohort in Johannesburg-Soweto, Z-scores were derived for weight-for-age, length/height-for age, and weight-for-length/height from the NCHS and CDC references, and WHO 2006 standards. Results: The pattern of mean Z-score change observed when applying the NCHS and CDC references was similar to one another, but different to that obtained when using the WHO 2006 standard. WHO 2006 identified children as being generally more stunted and more overweight. Conclusion: Discourse on the implementation of WHO 2006 and the impact on the primary health care system and public health monitoring in South Africa is needed, and sufficient planning is critical around not only the implementation of WHO 2006 but also maintaining comparability with historical malnutrition data

SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity

We used the Submillimeter Array (SMA) to image 860 micron continuum and CO(3-2) line emission in the ultraluminous merging galaxy Arp 220, achieving a resolution of 0.23" (80 pc) for the continuum and 0.33" (120 pc) for the line. The CO emission peaks around the two merger nuclei with a velocity signature of gas rotation around each nucleus, and is also detected in a kpc-size disk encompassing the binary nucleus. The dust continuum, in contrast, is mostly from the two nuclei. The beam-averaged brightness temperature of both line and continuum emission exceeds 50 K at and around the nuclei, revealing the presence of warm molecular gas and dust. The dust emission morphologically agrees with the distribution of radio supernova features in the east nucleus, as expected when a starburst heats the nucleus. In the brighter west nucleus, however, the submillimeter dust emission is more compact than the supernova distribution. The 860 micron core, after deconvolution, has a size of 50-80 pc, consistent with recent 1.3 mm observations, and a peak brightness temperature of (0.9-1.6)x10^2 K. Its bolometric luminosity is at least 2x10^{11} Lsun and could be ~10^{12} Lsun depending on source structure and 860 micron opacity, which we estimate to be of the order of tau_{860} ~ 1 (i.e., N_{H_2} ~ 10^{25} cm^{-2}). The starbursting west nuclear disk must have in its center a dust enshrouded AGN or a very young starburst equivalent to hundreds of super star clusters. Further spatial mapping of bolometric luminosity through submillimeter imaging is a promising way to identify the heavily obscured heating sources in Arp 220 and other luminous infrared galaxies.Comment: ApJ. in press. 26 pages, 10 figure