Nutritional Composition of Stevia rebaudiana Bertoni Leaf: Effect of Drying Method

Purpose: To determine the effect of three methods of drying, viz, sun, oven and microwave, on Steviarebaudiana Bertoni leaf’s nutritional composition.Methods: Fresh Stevia rebaudian bertoni leaves were dried separately by sun, oven and microwave.The chemical composition was determined by Association of Official Agricultural Chemists (AOAC)method. Tannin content was measured by titrimetric method while heavy metals were analyzed byatomic absorption spectrometry.Results: The following data were obtained for the plant when the three drying methods were employed:moisture content, 4.45 – 10.73 %; ash, 4.65 – 12.06 %; protein, 12.44 – 13.68 %; fat, 4.18 – 6.13 %;total dietary fiber, 4.35 – 5.26 % and total carbohydrates, 63.10 – 73.99 %. The pH value was 5.96, 5.95and 6.24 for sun, oven and microwave drying, respectively. Total energy of the plant material was in therange 362.3 – 384.2 kcal/100 g while tannin content was in the range 5.43 – 5.91 %. Moreover,reducing sugar was 4.5, 4.8 and 5.3 %, respectively, for sun, oven and microwave drying. Heavy metalscontent varied in stevia leaves, with lead was detected in high concentration in sun-, oven- andmicrowave–dried materials with values of 4.77, 0.14 and 2.16 ìg/g, respectively, while thecorresponding values for cadmium were 0.49, 0.44 and 0.33 ìg/g, Arsenic level was 0.30, 0.09 and 0.10ìg/g for sun, oven and microwave drying, respectively. Mercury level was the same (0.1 ìg/g)irrespective of the drying method.Conclusion: The results obtained indicate that Stevia leaves is a good source of carbohydrate andother nutrients and hence a substitute for sugar in processed drinks. Furthermore, drying reducesnutritional values with the exception to fiber content.Keywords: Stevia rebaudiana Bertoni , Nutritional composition, Protein, Heavy metals, Drying, Totalenerg

Effort-reward imbalance and self-rated health among Gambian healthcare professionals

Questionnaire for the Investigation of Effort-reward Imbalance and Self-rated Health among Gambian Healthcare Professionals. (DOC 616 kb

A North American Arctic Aerosol Climatology using Ground-based Sunphotometry

The Arctic is known as a key area for the detection of climate changes and atmospheric pollution on a global scale. In this paper we describe a new Canadian sunphotometer network called AEROCAN, whose primary mandate is to establish a climatology of atmospheric aerosols. This network is part of AERONET, the worldwide federated sunphotometer network managed by the NASA Goddard Space Flight Center. The potential of sunphotometer data from the AERONET/AEROCAN network for monitoring of Arctic aerosols is illustrated, using examples of the multiyear variation of aerosol optical properties and atmospheric precipitable water vapour content at some stations, and in particular at Bonanza Creek, Alaska since 1994. Despite its sparse spatial density, the network represents an important tool for monitoring the spatio-temporal variation of Arctic aerosols. It also represents an important source of independent aerosol data, which we feel should be further developed in northern areas to improve our understanding of how atmospheric aerosols influence global climate.L'Arctique est reconnu comme une région clé pour la détection des changements climatiques et de la pollution atmosphérique à l'échelle planétaire. Cet article présente un nouveau réseau canadien de photomètres solaires (AEROCAN) dont le mandat principal est d'établir une climatologie des aérosols atmosphériques. Ce réseau est intégré au réseau fédéré mondial de photomètres solaires AERONET géré par le Centre des vols spatiaux Goddard de la NASA. Le potentiel des données héliophotométriques générées par le réseau AERONET/AEROCAN pour la surveillance des aérosols dans l'Arctique est illustré à l'aide d'exemples de la variation pluriannuelle des paramètres optiques des aérosols et du contenu en vapeur d'eau atmosphérique précipitable à diverses stations, en particulier à Bonanza Creek (Alaska) depuis 1994. Malgré sa faible densité spatiale, le réseau représente un outil important pour la surveillance de la variation spatio-temporelle des aérosols arctiques. Il représente en outre une source majeure de données indépendantes sur les aérosols, données dont la provenance devrait, selon nous, englober les régions boréales afin que nous ayons une meilleure compréhension de l'influence des aérosols atmosphériques sur le climat de la planète

Perception des paysans sur la contrainte de la mineuse de l'épi Heliocheilus albipunctella De Joannis, ravageur important du mil en zone sahélienne

Heliocheilus albipunctella De Joannis est un important ravageur des épis du mil en zone sahélienne. Pour documenter la perception des paysans par rapport à ce ravageur, une enquête a été réalisée en avril 2016 avec un échantillon de 732 producteurs dans cinq principales régions agricoles du Niger. Les résultats obtenus ont montré que: 1) 17 % des répondants ont pu décrire le cycle biologique de H. albipunctella; 2) le ravageur cause en moyenne 43 à 82 % de perte de production, une moyenne obtenue depuis 28 ans selon les régions; 3) 37 à 78 % des producteurs savent que les infestations des épis du mil sont favorisées par les semis précoces, les sécheresses et la nature sableuse du sol; 4) d'après la moitié des répondants le plus de dégâts sont observés au stade grenaison du mil; 5) plus de 80 % des producteurs ne connaissent aucune méthode de lutte contre ce ravageur. Ces informations interpellent sur l'incidence négative de H. albipunctella sur le rendement du mil dans ces zones précaires. La nécessité de développer un programme participatif de gestion intégrée de ce ravageur est recommandée

Perceptions de la variabilité climati que et stratégies d’adaptation dans le système oasien de Gouré (Sud-est Niger)

Les savoirs liés au temps et à l’espace, et l’identification des stratégies paysannes pour affronter les problèmes climatiques sont indispensables pour toute compréhension des questions climatiques. Pour mieux apprécier les perceptions de la variabilité climatique et les stratégies d’adaptation utilisées, une enquête semi structuré qui a concerné 60 personnes repartie dans 4 villages du département de Gouré, situé dans l’Est du Niger est conduite selon une approche qualitative et quantitative. Les effets de la variabilité climatique ressentis par les agriculteurs sont l’aridité du climat, l’augmentation de la température et le caractère aléatoire des pluies. Les éleveurs la perçoivent de façon indirecte à travers la réduction du fourrage et de la disponibilité d’eau. Ces effets ont poussé ces populations à adopter des stratégies d’adaptation comme la recherche de nouvelles variétés à cycle court et supportant les poches de sécheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacé, l’utilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le déstockage des animaux pendant la soudure, les prières collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets négatifs de la variabilité climatiques au Niger.Mots clés: Variabilité climatique, perception, stratégies d’adaptation, Gouré, NigerEnglish Title: Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)English AbstractKnowledge related to the perception of time and space, and identification of farmers’ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmers’ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of Gouré, located in eastern Niger. Results showed that farmers directly experience changes in  climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger.Keywords: climate variability, perception, strategies of adaptation, Goure, Nige

Effect of Pyrodextrinization, Crosslinking and Heat- Moisture Treatment on In vitro Formation and Digestibility of Resistant Starch from African Locust Bean (Parkia biglobosa)

Purpose: This investigation was carried out to determine the impact of Parkia biglobosa starch modification on the fractions, namely rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS).Methods: Aqueous solution of sodium hypochlorite and potassium hydroxide was used to extract starch prior to modification by pyrodextrinization, cross-linking and heat-moisture treatment. Solubility,swelling power, x-ray diffraction, scanning electron microscopy (SEM) and thermal properties of the native and modified starches were also studied.Results: Pyrodextrinization (PD), cross-linking (CL), and heat-moisture treatment (HMT) reduced the swelling power to 6.73, 4.17 and 5.57 g/g, respectively but increased solubility by 59.0, 41, 41.5 and 39.5 %, respectively, and tended to decrease gelatinization enthalpy (ÄH). Starch yield was 25.7 % on a whole seed basis. RS content significantly (p < 0.05) increased to 46.3, 49.2 and 45.3 %, respectively following PD, CL and HMT. X-ray diffraction resulrs indicate the presence of V-type crystallinity in the modified parkia starch while SEM showed PD and CL starch structures were more compact and dense than HMT starch which was irregularly-shaped formed.Conclusion: Native parkia starch modified by pyrodextrinization, cross-linking and heat-moisture treatment showed appreciably higher thermal stability which makes it suitable for incorporation in foods that are subject to high temperature processing and high shear.Keywords: Pyrodextrinization, Crosslinking, Heat-moisture treatment, Gelatinization, Resistant starch, Parkia biglobos

Effects of Phytosterol in Feed on Growth and Related Gene Expression in Muscles of Broiler Chickens

Purpose: To investigate the effect of phytosterol in a feed on growth and gene expression of broiler chickens.Methods: Seven isonitrogenous diets with graded levels of polyhydroxy phytosterol(Castastesrone) (15, 20, and 25 g/kg diet) and hydroxyphytosterol (â-sitosterol) (25, 50, and 75 g/kg diet) were used to feed broiler chickens for 45 d.Results: The dietary phytosterol significantly improved (p < 0.05) the body weight and feed intake of broiler chickens, especially with the 75 g/kg diet. In contrast, phytosterol supplementation was associated with significant (p < 0.05) hypotriglyceridemic effects with concurrent modifications ofdepressed antioxidant defence systems in the broiler chickens. Myogen, eIF4E, and S6k1 gene expression levels in tissues were significantly (p < 0.05) improved by dietary phytosterol. mTOR gene expression levels in muscle tissues were increased significantly (p < 0.05), but myostatin  (GDF-8) and ubiquitin levels were significantly decreased (p < 0.05).Conclusion: These results suggest that giving immediate phytosterol feeding regimen to chicks is a good feeding program for appropriate morphological development of the pectoralis major muscle and the  expression of genes necessary for muscle cell proliferation and   differentiation. Furthermore, the data suggest that developmental decline in skeletal muscle protein synthesis, may be partly attributed to developmental regulation of the activation of growth factor and nutrient components.Keywords: Broiler chicken, Polyhydroxy phytosterol; Hydroxyphytosterol, Feed, Antioxidant status, Gene expression

Measuring Morbidity Associated with Urinary Schistosomiasis: Assessing Levels of Excreted Urine Albumin and Urinary Tract Pathologies

Urinary schistosomiasis is a debilitating disease caused by a parasitic worm that dwells in the blood vessels, particularly those surrounding the human bladder wall. Although not directly associated with high patient mortality, this disease is linked to both short-term morbidity, e.g. visible blood in urine (acute), as well as long-term sequelae, e.g. urinary tract pathologies (chronic). Numerous control programmes based upon chemotherapy have been implemented in sub-Saharan Africa in an attempt to reduce the burden of disease inflicted, particularly in children. Although there are rapid tests to assess the prevalence of acute manifestations of disease (i.e. blood in urine), namely urine-reagent strips, monitoring of chronic manifestations (i.e. urinary tract pathologies) is still rather laborious, time-consuming and requires specialised equipment, e.g. portable ultrasonography, as well as highly trained staff. This study has attempted to evaluate associations between albuminuria (albumin in urine, a new application for the HemoCue photometer) and urinary tract pathologies, and consequently assess this new biochemical marker as a potential rapid proxy of chronic disease sequelae typical in children in areas where urinary schistosomiasis is of public health importance