97 research outputs found
Multiple Satellite Observations of Cloud Cover in Extratropical Cyclones
Using cloud observations from NASA Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, and CloudSat-CALIPSO, composites of cloud fraction in southern and northern hemisphere extratropical cyclones are obtained for cold and warm seasons between 2006 and 2010, to assess differences between these three data sets, and between summer and winter cyclones. In both hemispheres and seasons, over the open ocean, the cyclone-centered cloud fraction composites agree within 5% across the three data sets, but behind the cold fronts, or over sea ice and land, the differences are much larger. To supplement the data set comparison and learn more about the cyclones, we also examine the differences in cloud fraction between cold and warm season for each data set. The difference in cloud fraction between cold and warm season southern hemisphere cyclones is small for all three data sets, but of the same order of magnitude as the differences between the data sets. The cold-warm season contrast in northern hemisphere cyclone cloud fractions is similar for all three data sets: in the warm sector, the cold season cloud fractions are lower close to the low, but larger on the equator edge than their warm season counterparts. This seasonal contrast in cloud fraction within the cyclones warm sector seems to be related to the seasonal differences in moisture flux within the cyclones. Our analysis suggests that the three different data sets can all be used confidently when studying the warm sector and warm frontal zone of extratropical cyclones but caution should be exerted when studying clouds in the cold sector
The scope of maxillofacial prosthodontics
Oral cancer may affect up to 275 000 new patients per year
worldwide. Many of these will be disfigured by the destruction
of tissue within the face and head area. Maxillofacial prosthodontics
can play a vital role in restoring such patients to a semblance of normality in appearance and function. This article will describe the role of maxillofacial prosthodontics in the treatment of these oral cancer patients.http://www.sada.co.z
COVID-19 vaccines – less obfuscation, more transparency and action
Letter by Venter et al. on editorial by Schoub (Dial down the rhetoric over COVID-19 vaccines. S Afr Med J 2021;111(6):522-523. https://doi.org/10.7196/SAMJ.2021.v111i6.15740)
The effect of dicyclohexylamine and fumagillin on Nosema ceranae-infected honey bee (Apis mellifera) mortality in cage trial assays
International audienceAbstractBoth commercially available fumagillin-based treatments for honey bees (Apis mellifera), Fumagilin-B® as well as Fumidil-B®, contain the reportedly genotoxic and tumorigenic compound dicyclohexylamine (DCH) as the counter ion in the fumagillin-DCH salt. The effect of DCH, purified fumagillin (containing no DCH), and the commercial formulation Fumagilin-B® (containing both fumagillin as well as DCH) on the mortality of caged Nosema ceranae-infected honey bees was investigated. A statistically significant risk of bee mortality associated with oral exposure to DCH was observed. DCH is also known to be significantly more stable than fumagillin in honey under a variety of temperature conditions, both in the presence and absence of light. The presence of DCH in the hive is therefore a potential concern for bee health and also for food safety
Evaluation of Fumagilin-B® and other potential alternative chemotherapies against Nosema ceranae-infected honeybees (Apis mellifera) in cage trial assays
International audienceAbstractFumagilin-B® is the only currently registered chemical treatment available to combat nosema disease in apiculture. Fumagillol, the basic hydrolysis product of fumagillin, two semisynthetic fumagillin analogues, and four in-house purely synthetic compounds which were designed to mimic the mode of action of fumagillin against the methionine aminopeptidase type 2 (MetAP-2) enzyme, was observed to exhibit statistically significant biological activity against Nosema ceranae-infected caged bees. None of these compounds were, however, as effective as Fumagilin-B®. The commercially available thymol and enilconazole also exhibited activity against N. ceranae, with thymol being the most promising chemical treatment other than Fumagilin-B®. High cumulative bee mortality was associated with the therapeutic dosage of Fumagilin-B® during our study, suggesting the need for continued investigation
Modelling of the multi-transition periodic flaring in G9.62+0.20E
We present detailed modeling of periodic flaring events in the 6.7 GHz and
12.2 GHz methanol lines as well as the OH 1665 MHz and 1667 MHz transitions
observed in the G9.62+0.20E star-forming region. Our analysis is performed
within the framework of the one-dimensional Maxwell-Bloch equations, which
intrinsically cover the complementary quasi-steady state maser and transient
superradiance regimes. We find that the variations in flaring time-scales
measured for the different species/transitions, and sometimes even for a single
spectral line, are manifestations of and are best modeled with Dicke's
superradiance, which naturally accounts for a modulation in the duration of
flares through corresponding changes in the inversion pump. In particular, it
can explain the peculiar behaviour observed for some features, such as the
previously published result for the OH 1667 MHz transition at
km s as well as the methanol 6.7 GHz line at
km s, through a partial quenching of the
population inversion during flaring events.Comment: 13 pages, 13 figures, accepted MNRA
Safeguarding maternal and child health in South Africa by starting the Child Support Grant before birth: Design lessons from pregnancy support programmes in 27 countries
Background: Deprivation during pregnancy and the neonatal period increases maternal morbidity, reduces birth weight and impairs child development, with lifelong consequences. Many poor countries provide grants to mitigate the impact of poverty during pregnancy. South Africa (SA) offers a post-delivery Child Support Grant (CSG), which could encompass support during pregnancy, informed by lessons learnt from similar grants.
Objectives: To review design and operational features of pregnancy support programmes, highlighting features that promote their effectiveness and efficiency, and implications thereof for SA.
Methods: Systematic review of programmes providing cash or other support during pregnancy in low- and middle-income countries.
Results: Thirty-two programmes were identified, across 27 countries. Programmes aimed to influence health service utilisation, but also longer-term health and social outcomes. Half included conditionalities around service utilisation. Multifaceted support, such as cash and vouchers, necessitated complex parallel administrative procedures. Five included design features to diminish perverse incentives. These and other complex features were often abandoned over time. Operational barriers and administrative costs were lowest in programmes with simplified procedures and that were integrated within child support.
Conclusions: Pregnancy support in SA would be feasible and effective if integrated within existing social support programmes and operationally simple. This requires uncomplicated enrolment procedures (e.g. an antenatal card), cash-only support, and few or no conditionalities. To overcome political barriers to implementation, the design might initially need to include features that discourage pregnancy incentives. Support could incentivise service utilisation, without difficult-to-measure conditionalities. Beginning the CSG in pregnancy would be operationally simple and could substantially transform maternal and child health
A-Train Based Observational Metrics for Model Evaluation in Extratropical Cyclones
Extratropical cyclones contribute most of the precipitation in the midlatitudes, i.e. up to 70 during winter in the northern hemisphere, and can generate flooding, extreme winds, blizzards and have large socio-economic impacts. As such, it is important that general circulation models (GCMs) accurately represent these systems so their evolution in a warming climate can be understood. However, there are still uncertainties on whether warming will increase their frequency of occurrence, their intensity and how much rain or snow they bring. Part of the issue is that models have trouble representing their strength, but models also have biases in the amount of clouds and precipitation they produce. This is caused by potential issues in various aspects of the models: convection, boundary layer, and cloud scheme to only mention a few. In order to pinpoint which aspects of the models need improvement for a better representation of extratropical cyclone precipitation and cloudiness, we will present A-train based observational metrics: cyclone-centered, warm and cold frontal composites of cloud amount and type, precipitation rate and frequency of occurrence. Using the same method to extract similar fields from the model, we will present an evaluation of the GISS-ModelE2 and the IPSL-LMDZ-5B models, based on their AR5 and more recent versions. The AR5 version of the GISS model underestimates cloud cover in extratropical cyclones while the IPSL AR5 version overestimates it. In addition, we will show how the observed CloudSat-CALIPSO cloud vertical distribution across cold fronts changes with moisture amount and cyclone strength, and test if the two models successfully represent these changes. We will also show how CloudSat-CALIPSO derived cloud type (i.e. convective vs. stratiform) evolves across warm fronts as cyclones age, and again how this is represented in the models. Our third process-based analysis concerns cumulus clouds in the post-cold frontal region and how their amount relates to the stability of the boundary layer. This test uses Aqua cloud and vertical atmospheric profiles and when applied to the model output can help assess the accuracy of the convection, boundary layer and cloud scheme
Safeguarding maternal and child health in South Africa by starting the Child Support Grant before birth: Design lessons from pregnancy support programmes in 27 countries
Background. Deprivation during pregnancy and the neonatal period increases maternal morbidity, reduces birth weight and impairs child development, with lifelong consequences. Many poor countries provide grants to mitigate the impact of poverty during pregnancy. South Africa (SA) offers a post-delivery Child Support Grant (CSG), which could encompass support during pregnancy, informed by lessons learnt from similar grants.Objectives. To review design and operational features of pregnancy support programmes, highlighting features that promote their effectiveness and efficiency, and implications thereof for SA.Methods. Systematic review of programmes providing cash or other support during pregnancy in low- and middle-income countries.Results. Thirty-two programmes were identified, across 27 countries. Programmes aimed to influence health service utilisation, but also longer-term health and social outcomes. Half included conditionalities around service utilisation. Multifaceted support, such as cash and vouchers, necessitated complex parallel administrative procedures. Five included design features to diminish perverse incentives. These and other complex features were often abandoned over time. Operational barriers and administrative costs were lowest in programmes with simplified procedures and that were integrated within child support.Conclusions. Pregnancy support in SA would be feasible and effective if integrated within existing social support programmes and operationally simple. This requires uncomplicated enrolment procedures (e.g. an antenatal card), cash-only support, and few or no conditionalities. To overcome political barriers to implementation, the design might initially need to include features that discourage pregnancy incentives. Support could incentivise service utilisation, without difficult-to-measure conditionalities. Beginning the CSG in pregnancy would be operationally simple and could substantially transform maternal and child health
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