172 research outputs found
Obstetric medicine: Interlinking obstetrics and internal medicine
Medical problems account for almost 50% of all maternal deaths in South Africa. The most recent report of the National Committee on Confidential Enquiries into Maternal Deaths (NCCEMD) (2008 - 2010) stated that 40.5% of deaths were due to non-pregnancy-related infections, which are mostly HIV-related, and 8.8% were due to medical or surgical disorders. Obstetric physicians have a specific role in managing pregnant and postpartum women with medical problems and, in partnership with obstetricians, can contribute to reducing maternal morbidity and mortality. There are physiological changes in almost all systems in pregnancy. For example, changes in the cardiovascular, respiratory and haematological systems are particularly important when assessing the cause and management of medical problems in pregnant women. Such problems may be unique to pregnancy, exacerbated by pregnancy, or unrelated to pregnancy. They may be present prior to pregnancy, or present for the first time in pregnancy. Some medical problems are worsened by pregnancy. Pregnant women may improve or remain stable, or their disease may predictably or unpredictably deteriorate.This article discusses the role of obstetric physicians in managing medical problems in pregnant women. A case is described of a pregnant woman with common medical problems, resulting in a serious complication when treatment is interrupted.Â
Methods that matter in addressing cultural diversity with teacher candidates
Drawing
on a combination of prior experience, theoretical stance, and intuition, along
with pedagogical practices identified to be effective in addressing diversity
with teacher candidates, a model for teaching multicultural education to
teacher candidates was designed. This study examined how particular elements of
this model were effective in developing teacher candidate’s cultural competence.
The results indicate that teacher candidates gained substantial knowledge about and experiences with issues of
diversity by the end of the course. Participants pointed to the multiple
methods employed in the class; in particular the interactive strategies, group
work, diverse cultural experiences, and opportunities to critically reflect on
these experiences as accounting
for their gains. Their sense of ownership and understanding has given them the ability to
use these strategies in their own future work. Implications
for research and teacher education are discussed.</p
The Effect of Different Organic Fertilizers on Yield and Soil and Crop Nutrient Concentrations
At present, organic fertilizers are not widely used in intensive arable agriculture, and not much is known about their effects on crop nutrition. In a field experiment at Rothamsted, UK, anaerobic digestate (AD), compost, farmyard manure (FYM), straw, and mixes of amendment + straw, were applied at: 1, 1.75, 2.5 or 3.5 t carbon ha−1, with all plots receiving the same input of mineral fertilizer. After five seasons of application, plots receiving non-straw amendments had greater straw and grain yield of 28% and 18% respectively, and plots receiving the highest amendment rate had a 37% higher straw and 23% higher grain yield, compared to control plots. Whereas, the straw-only amendment did not increase yield compared to the control. The concentrations of secondary and micro nutrients in the crop, particularly P, Ca, and S in the straw, and P and Fe in the grain, were significantly greater in the crop receiving non-straw amendment compared to the control. Interestingly K, Fe, and Zn were greater in the crop straw treated with the straw-only amendment. Therefore ‘biomass dilution’ of secondary and micro nutrients did not occur in the higher-yielding amended plots after five seasons, and organic fertilizers would improve the quality of high-yielding, intensively produced crops. The study also demonstrates that portable x-ray fluorescence (pXRF) could be a reliable, cost-effective tool for screening potential organic fertilizers
Transactions Processing Subsystems for Databases Based On ARIES Write-Ahead Logging for The Client-Server Architecture Approach
This paper proposes a formal framework specification that applies an advanced recovery mechanism, functional in a client-server architecture while addressing atomicity and consistency issues. Another palpable issue in using such dominant architectures is recovery. This paper also addresses this issue in context with the client-server architecture using extensions of the original ARIES algorithm and concepts of Software Transaction Memory. This novelty has been successfully implemented and tested for propriety and applicability
A Flexible Framework For Implementing Multi-Nested Software Transaction Memory
Programming with locks is very difficult in multi-threaded programmes. Concurrency control of access to shared data limits scalable locking strategies otherwise provided for in software transaction memory. This work addresses the subject of creating dependable software in the face of eminent failures. In the past, programmers who used lock-based synchronization to implement concurrent access to shared data had to grapple with problems with conventional locking techniques such as deadlocks, convoying, and priority inversion. This paper proposes another advanced feature for Dynamic Software Transactional Memory intended to extend the concepts of transaction processing to provide a nesting mechanism and efficient lock-free synchronization, recoverability and restorability. In addition, the code for implementation has also been researched, coded, tested, and implemented to achieve the desired objectives
Polyurea-Functionalized Multiwalled Carbon Nanotubes
An in situ polycondensation approach was applied to functionalize multiwalled carbon nanotubes (MWNTs), resulting in various linear or hyperbranched polycondensed polymers [e.g., polyureas, polyurethanes, and poly(urea-urethane)-bonded carbon nanotubes]. The quantity of the grafted polymer can be easily controlled by the feed ratio of monomers. As a typical example, the polyurea-functionalized MWNTs were measured and characterized in detail. The oxidized MWNTs (MWNT-COOH) were converted into acyl chloride-functionalized MWNTs (MWNT-COCl) by reaction with neat thionyl chloride (SOCl2). MWNT-COCl was reacted with excess 1,6-diaminohexane, affording amino-functionalized MWNTs (MWNT-NH2). In the presence of MWNT-NH2, the polyurea was covalently coated onto the surfaces of the nanotube by in situ polycondensation of diisocyanate [e.g., 4,4‘-methylenebis(phenylisocyanate)] and 1,6-diaminohexane, followed by the removal of free polymer via repeated filtering and solvent washing. The coated polyurea content can be controlled to some extent by adjusting the feed ratio of the isocyanato and amino groups. The structure and morphology of the resulting nanocomposites were characterized by FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM measurements. The polyurea-coated MWNTs showed interesting self-assembled flat- or flowerlike morphologies in the solid state. The signals corresponding to that of the D and G bands of the carbon nanotubes were strongly attenuated after polyurea was chemically tethered to the MWNT surfaces. Comparative experiments showed that the grafted polymer species and structures have a strong effect on the Raman signals of polymer-functionalized MWNTs
Portable X-ray fluorescence (pXRF) calibration for analysis of nutrient concentrations and trace element contaminants in fertilisers
With the increasing popularity of local blending of fertilisers, the fertiliser industry faces issues regarding quality control and fertiliser adulteration. Another problem is the contamination of fertilisers with trace elements that have been shown to subsequently accumulate in the soil and be taken up by plants, posing a danger to the environment and human health. Conventional characterisation methods necessary to ensure the quality of fertilisers and to comply with local regulations are costly, time consuming and sometimes not even accessible. Alternatively, using a wide range of unamended and intentionally amended fertilisers this study developed empirical calibrations for a portable handheld X-ray fluorescence (pXRF) spectrometer, determined the reliability for estimating the macro and micro nutrients and evaluated the use of the pXRF for the high-throughput detection of trace element contaminants in fertilisers. The models developed using pXRF for Mg, P, S, K, Ca, Mn, Fe, Zn and Mo had R2 values greater or equal to 0.97. These models also performed well on validation, with R2 values greater or equal to 0.97 (except for Fe, R2val = 0.55) and slope values ranging from 0.81 to 1.44. A second set of models were developed with a focus on trace elements in amended fertilisers. The R2 values of calibration for Co, Ni, As, Se, Cd and Pb were greater than or equal to 0.80. At concentrations up to 1000 mg kg-1, good validation statistics were also obtained; R2 values ranged from 0.97–0.99, except in one instance. The regression coefficients of the validation also had good prediction in the range of 0–100 mg kg-1 (R2 values were from 0.78–0.99), but not as well at lower concentrations up to 20 mg kg-1 (R2 values ranged from 0.10–0.99), especially for Cd. This study has demonstrated that pXRF can measure several major (P, Ca) and micro (Mn, Fe, Cu) nutrients, as well as trace elements and potential contaminants (Cr, Ni, As) in fertilisers with high accuracy and precision. The results obtained in this study is good, especially considering that loose powders were scanned for a maximum of 90 seconds without the use of a vacuum pump
Suicide attempts and behavioral correlates among a nationally representative sample of school-attending adolescents in the Republic of Malawi
Background: Suicide is among the top causes of adolescent mortality worldwide. While correlates of suicidalbehavior are better understood and delineated in upper-income countries, epidemiologic knowledge of suicidal behavior in low-income countries remains scant, particularly in the African continent. The present study sought to add to the epidemiologic literature on suicidal behavior in Africa by examining the behavioral correlates of suicide attempts among Malawi adolescents.Methods: A cross-sectional study using a nationally-representative sample extracted from publically-available data was conducted. Bivariate and multivariate analyses were performed to discern associations between suicide attempts and a host of behavioral variables. 2225 records were included in the study.Results: At the multivariate level, suicide attempters had significantly higher odds of being anxious, beingphysically bullied, having sustained a serious injury and having a greater number of lifetime sexual partners.Alcohol use (at an early age and within the past 30 days) was also associated with suicide attempts.Conclusions: These findings have the potential to guide public health interventions geared toward suicideprevention in Africa and other, similar regions, as well as provide the impetus for future epidemiologic studies on suicidal behavior in low-income countries.</p
Behavior of the Surviving Population of Listeria monocytogenes and Salmonella Typhimurium Biofilms Following a Direct Helium-Based Cold Atmospheric Plasma Treatment
Although the Cold Atmospheric Plasma (CAP) technology proved promising for inactivation of biofilms present on abiotic food contact surfaces, more research is required to examine the behavior of the CAP surviving biofilm-associated cells. It was therefore examined whether (i) CAP treated (Listeria monocytogenes and Salmonella Typhimurium) biofilm-associated cells were able to further colonize the already established biofilms during a subsequent incubation period and (ii) isolates of the surviving population became less susceptible toward CAP when the number of biofilm development—CAP treatment cycles increased. For this purpose, a direct treatment was applied using a helium-based Dielectric Barrier Discharge electrode configuration. Results indicated that the surviving population was able to further colonize the already established biofilms, since the cell density of the CAP treated + incubated biofilms equaled the initial density of the untreated biofilms. For the L. monocytogenes biofilms, also the total biomass proved to further increase, which might result in an even further increased resistance. The susceptibility of the biofilm-associated cells proved to be influenced by the specific number of CAP treatment cycles, which might potentially result in an overestimation of the CAP treatment efficacy and, consequently, an increased risk of food contamination
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