Will I send as much money home to Somalia as my Mum does?

LSE’s Adil Garane examines the culture of remittances among Somali migrants in London and how likely the practice is to continue with successive generations in the diaspora

Les CLE, institutions locales pertinentes mais peu fonctionnelles de gestion de l’eau

Un travail de recherche mené en 2017 avec l’accompagnement de l’International Water Management Institute par Letisia Somda, étudiante du Master Agrinovia à l’Université Joseph Ki-Zerbo à Ouagadougou, s’est intéressé au fonctionnement d’une institution locale de gestion de l’eau, le Comité Local de l’Eau (CLE). Les CLE sont conçus comme les maillons de base du cadre institutionnel de la Gestion Intégrée des Ressources en Eau au Burkina Faso. Le CLE Bougouriba 7 ou CLE BGB7, créé en 2010, a été relancé en 2015 mais connaissait toujours d’importantes difficultés de fonctionnement en 2017. L’étude a permis de faire le diagnostic de la gestion de l’eau dans cet espace. Elle a identifié les obstacles à la bonne gestion et proposé des solutions pour une meilleure gouvernance de l’ea

Influence des herbicides sur l'infestation par les adventices, la densité et la matière sèche des blés tendres (Triticum aestivum L.) et durs (Triticum durum Desf.).

Objectif: L’objectif de cette étude est d’évaluer les effets de la combinaison des herbicides 2,4-D®-sel d’amine + Lontrel® et du Quartz- super® (diflufénicanil-50 g/l+isoproturon-500 g/l) sur l’évolution de la flore adventice, sa densité et biomasse ainsi que la formation de matière sèche des variétés de blés tendres et durs d’écologies différentes dans la région de Moscou.Méthodologie et résultats : Le dispositif expérimental utilisé est un Split plot à quatre répétitions comprenant chacune un témoin (sans herbicide) et trois traitements herbicides : le Quartz- super (dose 1,0 l ha-1 m.a.) appliqué deux jours après semis et au tallage des blés, la combinaison 2,4-D (dose 1,8 kg ha-1 m.a.) + Lontrel (dose 0,3 kg ha-1 m a.) utilisée seulement au tallage. Les analyses de variance et de Hierarchical Column Prime Order (HCPO) ont été effectuées avec le logiciel Minitab 13.0 pour une comparaison des moyennes. Les résultats ont montré la présence de 18 espèces toutes dicotylédones appartenant à 10 familles botaniques qui sont regroupées en 03 groupes biologiques. Parmi celles–ci, 08 espèces (44,4%) sont annuelles de levée précoce et apparaissent très tôt au printemps, début du cycle végétatif des blés ; 09 (50%) sont des espèces facultatives de levée tardive en milieu du cycle de végétation des blés ou très souvent plus tardivement en fin été. Seule une espèce éphémère (5,6%) a été enregistrée au cours de l’étude. Les espèces facultatives tardives de l’été ont prédominé aussi bien par leur densité que par la matière sèche au cours de l’étude.Conclusion et application des résultats : L’herbicide Quartz-super en pré-levée s’est montré plus efficace avec une élimination de 81,7%-85,2% des adventices pour 29,6%-30,9% de matière sèche enregistrée à la récolte. Aucune différence significative n’a été observée entre les blés pour les densités enregistrées à maturité (81,7%- 84,5%). La matière sèche augmentait en moyenne de 8,7%-11% (Lyba), 14,8%-18,7% (Scham-2), 7,7%-8,5% (Bykhys-1) et Homari-9,6% -12%. L’étude recommande le 2,4-D + Lontrel ou le Quartz-super au tallage des blés lorsque des adventices de levée précoce sont prédominants. Au contraire, en présence d’adventices de levée tardive, de meilleurs résultats sont obtenus avec le Quartz super appliqué en pré-levée au deuxième jour des semis.Mots clés : blés, herbicides, densité, matière sèche.

Influence des facteurs agro-écologiques et des herbicides sur le rendement et les caractéristiques technologiques des grains et farines de blés tendres (Triticum aestivum L.) et durs (Triticum durum Desf.)

L’étude met en évidence les effets combinés des conditions écologiques, de la variété et des herbicides 2,4+Lontrel et Quartz super sur les rendements, les caractéristiques technologiques des grains et les propriétés boulangères des farines de blés d’origines écologiques différentes dans la région de Moscou. Pour ce faire, les rendements grains, leurs caractéristiques technologiques et la qualité boulangère des farines mesurés ont montrés que ces blés originaires de la Syrie et du Yémen peuvent avec succès s’adapter à la région de Moscou avec des rendements grains de 3,21-3,43 t/ha (Scham-2), 2,78-3,18 t/ha (Bykhys-1) et 2,64-2,95 t/ha (Homari). L’amélioration de l’état phytosanitaire des semis grâce aux herbicides a permis des gains de production grains en moyenne des blés tendres et durs Lyba, Scham-2, Bykhys-1 et Homari respectivement de 12,2-15,5%, 5,6- 6,8%, 9,0-11,1% et 9,8-11,7%. Indépendamment des herbicides appliqués, les différences observées dans la teneur des blés en protéine, gluten et amidon sont dues à la particularité de chaque variété. Aussi, les blés tendres Lyba et Scham-2 avec respectivement 13,4 et 13,8% (protéine) et 29,6 et 30,2% (gluten) sont panifiables tandis que les blés durs Bykhys-1 et Homari avec respectivement 15,7 et 15,5% (protéines) et 35,4% (gluten) sont pastifiables.Mots clés: Désherbants, protéine, gluten, qualité boulangère, panifiable

Etude de la dynamique de la macrofaune du sol sous culture de deux variétés de patate douce (Ipomea batatas) avec utilisation de différents modes de désherbage

Les communautés de la macrofaune du sol sous culture de deux variétés de patate douce (BF 11 et Ejumula 2) ont été inventoriées huit semaines après le repiquage des boutures. Les expérimentations ont été conduites en 2014 sur des parcelles du Centre de Formation et de Recherches Environnementales et Agricoles et de Formation de Kamboinsé de l’Institut de l’Environnement et de Recherches Agricoles (INERA). L’objectif de cette étude était d’identifier les différentes espèces de la faune du sol et de déterminer l’influence des différentes pratiques agricoles sur la faune du sol. Les termites ont été échantillonnés par la méthode des monolithes et par transect ; les vers de terre ont été échantillonnés uniquement par monolithes. Au total, quinze (15) espèces d’insectes et deux (02) espèces de vers de terre ont été enregistrées sous les traitements de la variété F0. Pour les insectes, les espèces identifiées sont : Microtermes pusillus, Feronia sp, Capsus sp, Amara sp, Amara auliae, Philontus marginatus, Dromius sp, Dromius quadrimaculatus, Xestobium sp, Pachycondyla analis, Paederus sp, Trinervitermes sp, Monyomorium abyssinicumi, Dyschirius globusus, Amitermes stephensoni. Les vers de terre identifiés sont Milsonia inermis et Dichogaster affininis. Les traitements sans désherbage ou désherbage tardif (après la huitième semaine) ont connu une meilleure installation de la macrofaune du sol. Les termites ont été les organismes favorisés dans les cas d’absence totale de désherbage. Le type de variété de patate douce n’a pas eu d’effet sur les communautés des la macrofaune du sol.© 2015 International Formulae Group. All rights reserved.Mots clés: Patate douce, macrofaune du sol, désherbage, traitementEnglish Title: Study of the dynamics of soil macrofauna under cultivation of two varieties of sweet potato (Ipomoea batatas) using different modes of weedingEnglish AbstractThe communities of soil macrofauna under cultivation of two varieties of sweet potato (BF 11 and Ejumula 2) were surveyed eight weeks after cuttings transplanting. The experiments were conducted in 2014 on plots of the Training Centre for Environmental Research and Agricultural of Kamboinsé, Training Institute for the Environment and Agricultural Research (INERA). The objective of this study was to identify the different species of soil fauna and determine the influence of different agricultural practices on soil fauna. The termites were sampled by the monoliths and transect method; earthworms were sampled only by monoliths. Fifteen (15) species of insects and two (02) species of earthworm have been registered in the treatment of F0 variety. For insects, the species identified are: Microtermes pusillus, Feronia sp Capsus sp sp Amara, Amara auliae, Philontus marginatus, Dromius sp Dromius quadrimaculatus Xestobium sp Pachycondyla analis, Paederus sp sp Trinervitermes, Monyomorium abyssinicumi, Dyschirius globosus , Amitermes stephensoni. Earthworms identified are Milsonia inermis and Dichogaster affininis. The treatment without weeding or late weeding (after the eighth week) had a better installation of the soil macrofauna. Termites were the favored organisms in the event of total absence of weeding. The type of variety of sweet potato hadn’t any effect on the communities of soil macrofauna.© 2015 International Formulae Group. All rights reserved.Keywords: Sweet potato, soil macrofauna, weeding, treatmen

Monitoring of UV spectral irradiance at Thessaloniki (1990?2005): data re-evaluation and quality control

International audienceWe present a re-evaluation and quality control of spectral ultraviolet irradiance measurements from two Brewer spectroradiometers operating regularly at Thessaloniki, Greece. The calibration history of the two instruments was re-examined and data flaws were identified by comparing quasi synchronous measurements. Analysis of the sensitivity of both instruments to variations of their internal temperature revealed that they have temperature coefficients of different sign. These coefficients exhibit small variability during the 15-year period. Using averaged temperature coefficients, we corrected both datasets. Corrections were applied for the angular response error using two different approaches depending on the availability of required ancillary data. The uncertainties associated with the measurements have been estimated and presented. Finally, the two datasets are compared using ratios of irradiance integrals at various bands in the UV, in order to assess any dependencies on the internal instrument temperature, solar zenith angle and wavelength

Evidence of heterosis in Okra (Abelmoschus esculentus) landraces from Burkina Faso

In our study, 24 hybrids obtained by diallel cross between ecotypes of okra were subjected to analysis of their combining ability effects and hybrid vigor for different important traits for producers and consumers. Parents and hybrids differed significantly for gca effect. UAE 3 and UAE 20 were found to be the best general combiners for 50% day of flowering and number of fruits per plant. While UAE 25, UAE 3 and UAE 5 were best for seeds weight per fruit and yield per plant; between tester lines, UAE 19 shown good gca effect of number of seeds per fruit and fruit yield per plant, when UAE 22 is good for number of seeds per fruit. The most heterotic combinations for number of fruits per plant were those including UAE 22 in their combination.The same hybrids have shown medium heterobeltiosis effect for fruit  length and in some of them (H22-20 and H22-5) was observed highest heterobeltiosis of yield per plant, varied from 59.90 to 77.57 respectively. The highest depression (non heterobeltiosis) was observed in hybrids with combination including H19 for number of seeds per fruit. Overall, the results discussed above indicated the fact that okra hybrid with UAE 22 hasgreat potentialities of maximizing fruit yield while hybrid H3-19 and H22-3 have the smallest days of flowering. Similarly, the heterosis effect  appeared in F1 in these hybrids with UAE22 as a mother form keeps up to the third generation. Key words: hybrid vigor, combining ability, okra, Burkina Faso

TROPOMI/S5P Total Column Water Vapor validation against AERONET ground-based measurements

Water vapor plays an important role in the greenhouse effect, rendering it an atmospheric constituent that requires continuous and global monitoring by different types of remote sensing instruments. The TROPOspheric Monitoring Instrument Sentinel-5 Precursor (TROPOMI/S5P) Total Column Water Vapor (TCWV) is a new product retrieved from the visible blue spectral range (435–455 nm), using an algorithm that was originally developed for the GOME-2/MetOp sensors. For the purposes of this work, 2.5 years of continuous satellite observations at high spatial resolution are validated against co-located (in space and in time) precipitable water Level 2.0 (quality-assured) ground-based measurements from the NASA AERONET (AErosol RObotic NETwork). The network uses Cimel Sun photometers located at approximately 1300 stations globally to monitor precipitable water among other products. Based on data availability, 369 of the stations were used in this study. The two datasets, satellite- and ground-based, were co-located, and the relative differences of the comparisons were calculated and statistically analyzed. The Pearson correlation coefficient of the two products is found to be 0.91, and the mean bias of the overall relative percentage differences is of the order of −2.7 %. For the Northern Hemisphere midlatitudes (30–60∘ N), where the density of the ground-based stations is high, the mean relative bias was found to be −1.8 %, while in the tropics (±15∘) the TROPOMI TCWV product has a relative dry bias of up to −10 %. The effect of various algorithm and geophysical parameters, such as air mass factor, solar zenith angle, clouds and albedo, is also presented and discussed. It was found that the cloud properties affect the validation results, leading the TCWV to a dry bias of −20 % for low cloud heights (cloud top pressure (CTP) >800 hPa). Moreover, cloud albedo introduces a wet bias of 15 % when it is below 0.3 and a dry bias up to −25 % when the clouds are more reflective. Overall, the TROPOMI/S5P TCWV product, on a global scale and for moderate albedo and cloudiness, agrees well at  % with the AERONET observations but probably within about −8 % to −13 % with respect to the “truth”

TROPOMI/S5P Total Column Water Vapor validation against AERONET ground-based measurements

Water vapor plays an important role in the greenhouse effect, rendering it an atmospheric constituent that requires continuous and global monitoring by different types of remote sensing instruments. The TROPOspheric Monitoring Instrument Sentinel-5 Precursor (TROPOMI/S5P) Total Column Water Vapor (TCWV) is a new product retrieved from the visible blue spectral range (435–455 nm), using an algorithm that was originally developed for the GOME-2/MetOp sensors. For the purposes of this work, 2.5 years of continuous satellite observations at high spatial resolution are validated against co-located (in space and in time) precipitable water Level 2.0 (quality-assured) ground-based measurements from the NASA AERONET (AErosol RObotic NETwork). The network uses Cimel Sun photometers located at approximately 1300 stations globally to monitor precipitable water among other products. Based on data availability, 369 of the stations were used in this study. The two datasets, satellite- and ground-based, were co-located, and the relative differences of the comparisons were calculated and statistically analyzed. The Pearson correlation coefficient of the two products is found to be 0.91, and the mean bias of the overall relative percentage differences is of the order of −2.7 %. For the Northern Hemisphere midlatitudes (30–60∘ N), where the density of the ground-based stations is high, the mean relative bias was found to be −1.8 %, while in the tropics (±15∘) the TROPOMI TCWV product has a relative dry bias of up to −10 %. The effect of various algorithm and geophysical parameters, such as air mass factor, solar zenith angle, clouds and albedo, is also presented and discussed. It was found that the cloud properties affect the validation results, leading the TCWV to a dry bias of −20 % for low cloud heights (cloud top pressure (CTP) &gt;800 hPa). Moreover, cloud albedo introduces a wet bias of 15 % when it is below 0.3 and a dry bias up to −25 % when the clouds are more reflective. Overall, the TROPOMI/S5P TCWV product, on a global scale and for moderate albedo and cloudiness, agrees well at -2.7±4.9 % with the AERONET observations but probably within about −8 % to −13 % with respect to the “truth”.</p

Temperature dependence of the Brewer global UV measurements

Spectral measurements of global UV irradiance recorded by Brewer spectrophotometers can be significantly affected by instrument-specific optical and mechanical features. Thus, proper corrections are needed in order to reduce the associated uncertainties to within acceptable levels. The present study aims to contribute to the reduction of uncertainties originating from changes in the Brewer internal temperature, which affect the performance of the optical and electronic parts, and subsequently the response of the instrument. Until now, measurements of the irradiance from various types of lamps at different temperatures have been used to characterize the instruments' temperature dependence. The use of 50 W lamps was found to induce errors in the characterization due to changes in the transmissivity of the Teflon diffuser as it warms up by the heat of the lamp. In contrast, the use of 200 or 1000 W lamps is considered more appropriate because they are positioned at longer distances from the diffuser so that warming is negligible. Temperature gradients inside the instrument can cause mechanical stresses which can affect the instrument's optical characteristics. Therefore, during the temperature-dependence characterization procedure warming or cooling must be slow enough to minimize these effects. In this study, results of the temperature characterization of eight different Brewer spectrophotometers operating in Greece, Finland, Germany and Spain are presented. It was found that the instruments' response changes differently in different temperature regions due to different responses of the diffusers' transmittance. The temperature correction factors derived for the Brewer spectrophotometers operating at Thessaloniki, Greece, and Sodankylä, Finland, were evaluated and were found to remove the temperature dependence of the instruments' sensitivity.This article is based upon work from COST Action ES1207 “A European Brewer Network (EUBREWNET)”, supported by COST (European Cooperation in Science and Technology) and from the ENV59-ATMOZ (“Traceability for atmospheric total column ozone”) Joint Research Programme (JRP)