448 research outputs found
“Have milk, maas or yoghurt every day”: a food-based dietary guideline for South Africa
A national working group recently reached consensus that a guideline message for milk consumption should form part of the set of revised food-based dietary guidelines (FBDGs) for South Africa. The message was formulated as: “Have milk, maas or yoghurt every day”. This paper provides scientific support for this FBDG, based on the nutrition and healthprofile of South Africans; addresses concerns about possible detrimental effects of milk consumption, such as lactose intolerance, saturated fat and trans-fat content, milk allergies and dental caries in children; and identifies barriers to increased consumption. The guideline refers to milk, maas and yoghurt, and not all dairy products. This is based on the nutrient contribution of these products to a healthy diet. Milk (and some dairy products) has a low sodium-to-potassium ratio, as well as bioactive peptides, which may protect against the development of noncommunicable diseases. There is some evidence that the calcium in milk and dairy plays an important role in the regulation of body weight and bone mineral content in children. Available data show that milk and calcium intake in South Africans is low. Identified barriers include perceptions about lactose intolerance, taste, price, lack of knowledge on the nutritive value of milk and milk products, and possibly cultural taboos. As a result, increasing the consumption of milk, maas and yoghurt of South Africans will require active, multifaceted and multilevel promotion
High-Temperature Performance of Actively Cooled Vapor Phase Strengthened Nickel-Based Thermostructural Panels
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90639/1/AIAA-53998-163.pd
An Overview of Mites on Grapevine and the Discovery of a new Phytoseiidae Species; Typhlodromus (Typhlodromus) spiceae
The common grapevine (Vitis vinifera L.) is the main species used for wine making, with South Africa being one of the top wine exporting countries. Grapevine is vulnerable to a range of pests, includingmites. We present an overview of phytophagous and predatory mites on grapevine in South Africa anddescribe a new phytoseiid species which was discovered in the winelands region of Wellington, SouthAfrica. Grapevine shoots with leaves were collected over two growing seasons at four farms in Wellington.A nursery, mother block and a commercial vineyard were selected on each farm. The mites were removedwith a mite brushing machine and slide mounted. The Phytoseiidae Database, as well the most recentrelevant literature were used in confirming the new species. Illustrations of the new species were madeusing photographs taken by Zeiss Axioskop TM Research that included a Zen Soft Imaging System. Thenew Typhlodromus species, Typhlodromus (Typhlodromus) spiceae sp.n., is set apart from closely relatedspecies by setae Z4 being 0.7 times the length of Z5 and by having a short, saccular and thick-walledspermathecal. This species was found together with one phytophagous mite species (Brevipalpus lewisi)and several predatory mite species (Typhlodromus praeacutus, Typhlodromus saevus, Eusieus addoensis). Akey to identify females of the South African species of Typhlodromus (Typhlodromus) is provided
Sensory neuropathy and metabolic risk factors in human immune deficiency virus infected South Africans receiving protease inhibitors
BackgroundProtease inhibitors (PI)s have been associated with distal sensory polyneuropathy (DSP) and metabolic complications in high-income countries. No data exist in Africans where second-line antiretroviral therapy (ART) often include PIs.MethodWe performed a cross-sectional study to assess the DSP frequency and metabolic risk factors in community-based South Africans taking ritonavir-boosted lopinavir as PI. Examination findings categorized subjects as having DSP (≥1 neuropathic sign) or symptomatic DSP [DSP with symptom(s)]. Fasting-state glucose and lipid profiles were assessed. We compared the ritonavir/lopinavir-group to a nested group on first-line ART [dideoxy-nucleoside reverse transcriptase inhibitors (d-drugs)] selected from a dataset collected at the same time and matched for d-drug exposure.ResultsThe ritonavir/lopinavir-group (n=86) consisted predominantly of women (84%) with a median age of 36years (IQR 32–41). The median current CD4+ count was 489cells/μL (IQR 291–665). The median exposure time to ritonavir/lopinavir was 18months (IQR 10–26) and to d-drugs, 24months (IQR 16–38). DSP was present in 78% and symptomatic DSP in 48%; symptoms were most frequently of moderate intensity. Only age independently associated with DSP and symptomatic DSP (p=0.08 and p=0.04, respectively). None of the metabolic syndrome components showed associations with DSP or symptomatic DSP despite a trend towards hypertriglyceridemia overall. The ritonavir/lopinavir-group had less DSP compared to the d-drug only group (p=0.002) but the frequency of symptomatic DSP was similar (p=0.49).ConclusionRitonavir-boosted lopinavir did not add additional risk to developing DSP in this community-based African cohort after a median of 18months on second-line ART.Electronic supplementary materialThe online version of this article (doi:10.1186/s12981-015-0073-8) contains supplementary material, which is available to authorized users
Sub-threshold resonances in few-neutron systems
Three- and four-neutron systems are studied within the framework of the
hyperspherical approach with a local S-wave nn-potential. Possible bound and
resonant states of these systems are sought as zeros of three- and four-body
Jost functions in the complex momentum plane. It is found that zeros closest to
the origin correspond to sub-threshold (nnn) (1/2-) and (nnnn) (0+) resonant
states. The positions of these zeros turned out to be sensitive to the choice
of the --potential. For the Malfliet- Tjon potential they are
E(nnn)=-4.9-i6.9 (MeV) and E(nnnn)=-2.6-i9.0 (MeV). Movement of the zeros with
an artificial increase of the potential strength also shows an extreme
sensitivity to the choice of potential. Thus, to generate ^3n and ^4n bound
states, the Yukawa potential needs to be multiplied by 2.67 and 2.32
respectively, while for the Malfliet-Tjon potential the required multiplicative
factors are 4.04 and 3.59.Comment: Latex, 22 pages, no PS-figures, submitted to J.Phys.
Limits on Stellar and Planetary Companions in Microlensing Event OGLE-1998-BUL-14
We present the PLANET photometric data set for \ob14, a high magnification
() event alerted by the OGLE collaboration toward the
Galactic bulge in 1998. The PLANET data set consists a total of 461 I-band and
139 band points, the majority of which was taken over a three month period.
The median sampling interval during this period is about 1 hour, and the
scatter over the peak of the event is 1.5%. The excellent data
quality and high maximum magnification of this event make it a prime candidate
to search for the short duration, low amplitude perturbations that are
signatures of a planetary companion orbiting the primary lens. The observed
light curve for \ob14 is consistent with a single lens (no companion) within
photometric uncertainties. We calculate the detection efficiency of the light
curve to lensing companions as a function of the mass ratio and angular
separation of the two components. We find that companions of mass ratio are ruled out at the 95% confidence level for projected separations
between 0.4-2.4 \re, where \re is the Einstein ring radius of the primary
lens. Assuming that the primary is a G-dwarf with \re\sim3 {\rm AU} our
detection efficiency for this event is for a companion with the mass
and separation of Jupiter and for a companion with the mass and
separation of Saturn. Our efficiencies for planets like those around Upsilon
And and 14 Her are > 75%.Comment: Data available at http://www.astro.rug.nl/~planet/planetpapers.html
20 pages, 10 figures. Minor changes. ApJ, accepte
Directed genetic modification of African horse sickness virus by reverse genetics
African horse sickness virus (AHSV), a member of the Orbivirus genus in the family Reoviridae, is an
arthropod-transmitted pathogen that causes a devastating disease in horses with a mortality rate greater
than 90%. Fundamental research on AHSV and the development of safe, efficacious vaccines could benefit
greatly from an uncomplicated genetic modification method to generate recombinant AHSV. We demonstrate
that infectious AHSV can be recovered by transfection of permissive mammalian cells with transcripts
derived in vitro from purified AHSV core particles. These findings were expanded to establish a genetic
modification system for AHSV that is based on transfection of the cells with a mixture of purified core
transcripts and a synthetic T7 transcript. This approach was applied successfully to recover a directed
cross-serotype reassortant AHSV and to introduce a marker sequence into the viral genome. The ability to
manipulate the AHSV genome and engineer specific mutants will increase understanding of AHSV replication
and pathogenicity, as well as provide a tool for generating designer vaccine strains.The University of Pretoria’s Institutional
Research Theme programme. The National Research Foundation (South
Africa) provided E.M., D.J.P. and A.C. with bursaries.http://www.sajs.co.zaam201
African horse sickness virus infects BSR cells through macropinocytosis
Cellular pathways involved in cell entry by African horse sickness virus (AHSV), a member
of the Orbivirus genus within the Reoviridae family, have not yet been determined. Here, we
show that acidic pH is required for productive infection of BSR cells by AHSV-4, suggesting
that the virus is likely internalized by an endocytic pathway. We subsequently analyzed the
major endocytic routes using specific inhibitors and determined the consequences for AHSV-
4 entry into BSR cells. The results indicated that virus entry is dynamin dependent, but
clathrin- and lipid raft/caveolae-mediated endocytic pathways were not used by AHSV-4 to
enter and infect BSR cells. Instead, binding of AHSV-4 to BSR cells stimulated uptake of a
macropinocytosis-specific cargo and inhibition of Na+/H+ exchangers, actin polymerization
and cellular GTPases and kinases involved in macropinocytosis significantly inhibited
AHSV-4 infection. Altogether, the data suggest that AHSV-4 infects BSR cells by utilizing
macropinocytosis as the primary entry pathway.http://www.elsevier.com/locate/yviro2017-10-31hb2016Microbiology and Plant Patholog
- …