86 research outputs found
Bambara nut: A review of utlisation, market potential and crop improvement
Bambara groundnut ( Vigna subterranea (L.) Verdc.) originated in West
Africa but has become widely distributed throughout the semi-arid zone
of sub-Saharan Africa (SSA). Sharing a high nutritive value with other
widely consumed legumes, bambara has an appealing flavour which is
reflected in demand from small local and niche markets. Despite its
high and balanced protein content, bambara remains under-utilised
because it takes a long time to cook, contains anti-nutritional factors
and does not dehull easily. Bambara yields well under conditions which
are too arid for groundnut ( Arachis hypogea ), maize ( Zea mays L.)
and even sorghum ( Sorghum bicolar ). Its drought tolerance makes
bambara a useful legume to include in climate change adaptation
strategies. Existing bambara products are not well promoted in the
local or international markets and new products are needed that
highlight its inherent nutritional and culinary advantages. A number of
projects on bambara, involving several countries in SSA since the
1980s, have failed to stimulate a sustainable increase in the
production of the crop. The absence of functioning value chains has
been a factor in this failure, as accessible market outlets might
provide the required incentive for smallholder households to obtain
improved seed and invest more of their land and labour in the crop.
There is little documented evidence of trade in bambara but
circumstantial evidence indicates considerable international demand.
More attention should be given, therefore, to market research and
development, with crop improvement programmes being more market-led, if
bambara is to make a greater contribution to household income and rural
development in SSA.Les arachides Bambara ( Vigna subterranea (L.) Verdc.)
d\u2019origine Ouest Africaine ont \ue9t\ue9 largement
r\ue9pandues dans la zone semi aride sub saharienne. Avec sa valeur
nutritive \ue9lev\ue9e \ue0 c\uf4t\ue9 d\u2019autres
l\ue9gumes largement consomm\ue9es, bambara a une saveur attractive
qui se refl\ue8te dans sa demande sur des petits march\ue9s locaux.
Malgr\ue9 sa teneur \ue9quilibr\ue9e en prot\ue9ines, bambara
reste sous utilis\ue9 par suite du long moment de cuisson, contient
des facteurs antinutritionnels et sa coque ne s\u2019enl\ue8ve pas
facilement. Bambara produit de bons redements dans des conditions qui
sont trop arides pour les arachides ( Arachis hypogea ), le ma\ubfs
( Zea mays ) et m\ueame le sorgho ( Sorghum bicolar ). Sa
tol\ue9lance en s\ue9cheresse fait du bambara une l\ue9gume utile
surtout lorsqu\u2019il s\u2019agit des strat\ue9gies
d\u2019adaptation au changement climatique. Les produits existants de
bambara ne sont pas bien promus sur des march\ue9s locaux ou
internationaux et de nouveaux produits montrant tous les avantages
nutritionnels et culinaires sont d\ue9sir\ue9s. Un nombre de
projets sur bambara impliquant plusieurs pays d\u2019Afrique Sub
Saharienne depuis 1980, ont \ue9chou\ue9 de stimuler une
augmentation durable de la production de cette culture. L\u2019absence
de cha\ueenes des valeurs fonctionnelles a \ue9t\ue9 un facteur
de cet \ue9chec, \ue9tant donn\ue9 que des points de vente sur
les march\ue9s accessibles devraient motiver les petits m\ue9nages
pour obtenir des semences am\ue9lior\ue9es et plus investir dans
leurs terres et la main d\u2019oeuvre. Il ya tr\ue8s peu
d\u2019\ue9vidence document\ue9e sur le commerce du bambara mais
des \ue9vidences circonstancielles font montrent d\u2019une demande
internationale consid\ue9rable. Si bambara doit consid\ue9rablement
contribuer \ue0 la g\ue9n\ue9ration des revenus des m\ue9nages
et le d\ue9veloppement rural en Afrique Sub Saharienne, un effort
doit \ueatre mis dans la recherche et d\ue9veloppement, avec des
programmes soutenus d\u2019am\ue9lioration de la culture
orient\ue9s vers le march\ue9
Adenylate effects on protein phosphorylation in the interenvelope lumen of pea chloroplasts
A 64-kilodalton (kDa) protein, situated in the lumen between the inner and outer envelopes of pea (Pisum sativum L.) chloroplasts (Soll and Bennett 1988, Eur. J. Biochem., 175, 301–307) is shown to undergo reversible phosphorylation in isolated mixed envelope vesicles. It is the most conspicuously labelled protein after incubation of envelopes with 33 nmol·1-1 [-32P]ATP whereas incubation with 50 mol·1-1 [-32P]ATP labels most prominently two outer envelope proteins (86 and 23 kDa). Half-maximum velocity for phosphorylation of the 64-kDa protein occurs with 200 nmol·1-1 ATP, and around 40 mol·1-1 ATP for phosphorylation of the 86- and 23-kDa proteins, indicating the operation of two distinct kinases. GGuanosine-, uridine-, cytidine 5-triphosphate and AMP are poor inhibitors of the labelling of the 64-kDa protein with [-32P]ATP. On the other hand, ADP has a potent influence on the extent of labelling (half-maximal inhibition at 1–5 mol·1-1). The ADP-dependent appearance of 32P in ATP indicates that ADP acts by reversal of kinase activity and not as a competitive inhibitor. However, the most rapid loss of 32P from pre-labelled 64-kDa protein occurs when envelope vesicles are incubated with ATP t1/2=15 s at 20 molsd1-1 ATP). This induced turnover of phosphate appears to be responsible for the rapid phosphoryl turnover seen in situ
Decoherence as Decay of the Loschmidt Echo in a Lorentz Gas
Classical chaotic dynamics is characterized by the exponential sensitivity to
initial conditions. Quantum mechanics, however, does not show this feature. We
consider instead the sensitivity of quantum evolution to perturbations in the
Hamiltonian. This is observed as an atenuation of the Loschmidt Echo, ,
i.e. the amount of the original state (wave packet of width ) which is
recovered after a time reversed evolution, in presence of a classically weak
perturbation. By considering a Lorentz gas of size , which for large is
a model for an {\it unbounded} classically chaotic system, we find numerical
evidence that, if the perturbation is within a certain range, decays
exponentially with a rate determined by the Lyapunov exponent
of the corresponding classical dynamics. This exponential decay
extends much beyond the Eherenfest time and saturates at a time
, where is the effective dimensionality of the Hilbert space. Since quantifies the increasing uncontrollability of the quantum phase
(decoherence) its characterization and control has fundamental interest.Comment: 3 ps figures, uses Revtex and epsfig. Major revision to the text, now
including discussion and references on averaging and Ehrenfest time. Figures
2 and 3 content and order change
Mapping disparities in education across low- and middle-income countries
Educational attainment is an important social determinant of maternal, newborn, and child health1–3. As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting4–6. The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness7,8; however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health9–11. Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but—to our knowledge—no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries12–14. By geolocating subnational data for more than 184Â million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations
SARS-CoV-2 mRNA vaccine design enabled by prototype pathogen preparedness
A vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed to control the coronavirus disease 2019 (COVID-19) global pandemic. Structural studies have led to the development of mutations that stabilize Betacoronavirus spike proteins in the prefusion state, improving their expression and increasing immunogenicity1. This principle has been applied to design mRNA-1273, an mRNA vaccine that encodes a SARS-CoV-2 spike protein that is stabilized in the prefusion conformation. Here we show that mRNA-1273 induces potent neutralizing antibody responses to both wild-type (D614) and D614G mutant2 SARS-CoV-2 as well as CD8+ T cell responses, and protects against SARS-CoV-2 infection in the lungs and noses of mice without evidence of immunopathology. mRNA-1273 is currently in a phase III trial to evaluate its efficacy
Parental origin of sequence variants associated with complex diseases
To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldEffects of susceptibility variants may depend on from which parent they are inherited. Although many associations between sequence variants and human traits have been discovered through genome-wide associations, the impact of parental origin has largely been ignored. Here we show that for 38,167 Icelanders genotyped using single nucleotide polymorphism (SNP) chips, the parental origin of most alleles can be determined. For this we used a combination of genealogy and long-range phasing. We then focused on SNPs that associate with diseases and are within 500 kilobases of known imprinted genes. Seven independent SNP associations were examined. Five-one with breast cancer, one with basal-cell carcinoma and three with type 2 diabetes-have parental-origin-specific associations. These variants are located in two genomic regions, 11p15 and 7q32, each harbouring a cluster of imprinted genes. Furthermore, we observed a novel association between the SNP rs2334499 at 11p15 and type 2 diabetes. Here the allele that confers risk when paternally inherited is protective when maternally transmitted. We identified a differentially methylated CTCF-binding site at 11p15 and demonstrated correlation of rs2334499 with decreased methylation of that site.info:eu-repo/grantAgreement/EC/FP7/21807
Mapping disparities in education across low- and middle-income countries
Analyses of the proportions of individuals who have completed key levels of schooling across all low- and middle-income countries from 2000 to 2017 reveal inequalities across countries as well as within populations. Educational attainment is an important social determinant of maternal, newborn, and child health(1-3). As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting(4-6). The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness(7,8); however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health(9-11). Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but-to our knowledge-no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries(12-14). By geolocating subnational data for more than 184 million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations.Peer reviewe
Meta-analysis of type 2 Diabetes in African Americans Consortium
Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR) = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe
Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017
Background
Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea.
Methods
We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates.
Findings
The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage.
Interpretation
By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health
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