History of Centralization and Kingship in Sub-Saharan-Africa

Rwanda, a small land-locked country, has a very long and complex history, dating back to the precolonial period. Unlike most Sub-Saharan countries, numerous anthropologists and scholars have dedicated their time to uncovering and preserving Rwanda’s history. They have provided solid research and new interpretations on a topic filled with controversy over its social structure. Given the richness of the historical literature, Rwanda will serve as a case study for an analysis of the history of centralization and kingship in Sub-Saharan-Africa. The focus on political centralization is paramount in this study. First, every constitutional government, to a variable extent, necessitates centralization to operate properly. Even the central/federal power needs to exert authority over its decentralized constituencies. Therefore, the history of centralization reinforces more knowledge on current governmental systems. More importantly, this study is even more significant in the light of understanding the formation and the consolidation of early civilizations and the political customs of the modern day. In this regard, the impetus for this research on the African Great Lakes region is in no way synonymous to regionalism. Rather, it emanates from the discovery of avenues of research that can nourish knowledge about interethnic processes and highlight the establishment of a particular centralized political structure endemic to precolonial Rwanda. The ability of the Nyiginya Kingdom to form a centralized monarchy and even its history of oppression are indicative of its ability to survive and prosper in a region where other kingdoms struggled and floundered. This study will to add to the literature of ancient civilizations by utilizing the Nyiginya Kingdom as a reference point for centralized kingdom-statehood in Sub-Saharan Africa. From the well-administered nobility to the local traditional institutions, this study will present a comparative argument proving the particular significance of this monarchy in the formation of early centralized governments. As such, this hypothesis will be developed further in a comprehensive essay starting with a brief contextual presentation of the situation. Next, the academic literature on the topic will be analyzed. Finally, a thorough exploration of historical events will present a favorable argument about the importance, past and present, of the political structure of the Nyiginya Kingdom

Characterization of the circadian clock in Hooded Seals (Cystophora Cristata) and its interaction with mitochondrial metabolism A multi-tissue comparison and cell culture approach

Circadian rhythms regulate living organisms over a 24h period. From daily activity to cellular function. The polar regions are subject to different photoperiods across the year, which impact the environmental conditions on a seasonal and daily basis. Evidence of crosstalk between circadian core clock genes and hypoxia with genes involved the mitochondrial dynamics, as well as oxygen sensing, provide a basis to study those mechanisms in a model which faces those 2 challenges. The hooded seal (Cystophora Cristata) is an expert diver, with excellent hypoxia tolerance, and an arctic mammal exposed to the special light environment. The primary aim of this study was to characterize the circadian clockwork in the hooded seal using in-vivo sampling and hooded seal skin fibroblasts. The secondary aim was to explore the clockwork and the variation mitochondrial metabolism in a circadian context with the culture of hooded seal skin fibroblasts. We show that the clock genes are expressed in different seal tissues without a marked difference between midday and midnight. Nevertheless, seal skin fibroblasts respond to treatments designed to entrain the circadian clockwork and showed a significant circadian oscillation in the key clock genes; PER-2, ARNTL, NR1D1. Finally, we showed that there is a time-of-day variation in the respiratory capacity of mitochondria in seal skin fibroblasts and in MFN1, a gene involved in mitochondrial dynamics. Overall, this thesis provides new knowledge on the circadian rhythm in seals and how mitochondrial metabolism may be influenced. These data encourage further research to depict mitochondrial dynamics and metabolism in a circadian and hypoxic conditions, as well as animal circadian behavior for an integrative perspective

Assessment of the Sasakawa Africa Fund for Extension Education's (SAFE) training program in Mali: Graduates' perceptions of the training's impact as well as opportunities and constraints related to Supervised Enterprise Projects (SEPs)

Scope and Method of Study: The sample for this descriptive study included 50 mid-career Extension professionals who had completed the Sasakawa Africa Fund for Extension Education (SAFE) training program in the Republic of Mali (West Africa). The study assessed perceptions of SAFE graduates regarding the training's impact on their professional performance and related behaviors of the graduates' clients. The study followed a triangulation mixed methods design (Creswell, 2005), which included using a survey instrument and conducting semi-structured focus group interviews to collect data.Findings and Conclusions: Most of the study participants were Muslim males who averaged nearly 47 years of age and 17 years of experience in Extension. Participants served in seven of the eight administrative regions of Mali and in the District of Bamako. Seven-in-ten participants had entered the SAFE training program with a Technician degree and specialization in Agriculture. Participants perceived the training had a significant impact on their overall professional competence, and that the knowledge they acquired increased their effectiveness and satisfied their training needs. All of the graduates were upgraded to an advanced job category after completing the training. Nearly two-thirds indicated they observed changes in their clients' practices attributed to the SAFE training. Significant associations and relationships (p < .05) between selected personal and professional characteristics of graduates, between their characteristics and selected perceptions, as well as between their selected perceptions were revealed. Male graduates were significantly more likely to still be Extension educators. In addition, graduates overall satisfaction with their SAFE training experience was significantly related to their willingness to encourage a colleague to participate in the training. Qualitative findings revealed that the graduates' experiences with Supervised Enterprise Projects (SEPs) overall was positive and useful. However, some issues and concerns regarding SEPs emerged, including cost, supervision, as well as standards regarding project reporting and thesis writing

Machine Learning For Beamline Steering

Beam steering is the process involving the calibration of the angle and position at which a particle accelerator's electron beam is incident upon the x-ray target with respect to the rotation axis of the collimator. Beam Steering is an essential task for light sources. In the case under study, the LINAC To Undulator (LTU) section of the beamline is difficult to aim. Each use of the accelerator requires re-calibration of the magnets in this section. This involves a substantial amount of time and effort from human operators, while reducing scientific throughput of the light source. We investigate the use of deep neural networks to assist in this task. The deep learning models are trained on archival data and then validated on simulation data. The performance of the deep learning model is contrasted against that of trained human operators

Stirring up sorghum hybrid breeding targeting West African smallholder farmers low input environments

Food supply and income in rural areas of West Africa (WA) depend strongly on the local production, and mostly on farmers field production of root and tuber crops, and cereals. To feed an ever-increasing population in a context of climate-change and low-input cultural conditions, breeding for resilient crops can guarantee smallholder farmers food security and cash income for a sustainable rural development. Sorghum hybrids for WA were first explored in the early 1970s and hybrid crosses of Malian landraces with introduced Caudatum-race seed parents were evaluated in the early 80s. Although those hybrids exhibited good heterosis for grain yield, their lack of grain quality made them commercially unsustainable. Efforts by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and its partners resulted in the first series of Guinea-race based hybrids. The short statured hybrids were evaluated in several on-farm farmer-managed yield trials, and showed satisfactory grain yield and quality under farmers cultivation conditions. Although taller- relative to shorter- height sorghum can help reduce risks of panicle loss by grazing transhumant cattle, no indication on the yield potential of the tall statured hybrids is available. The advances achieved by ICRISAT and its partners in hybrid development justified establishing a long-term hybrid breeding program to provide farmers with hybrids with sufficient grain yield and good grain quality under low input conditions. However, the lack of quantitative genetic information about the genetic value of new experimental hybrids and their parents (Guinea-Caudatum to complete Guinea background, from different WA origins), or about the efficiency of alternative selection methods for targeting yield performance in the predominantly low-input and phosphorous-deficient sorghum production conditions hinders sorghum hybrid development for this region. Sorghum hybrid breeding was commercially feasible only after the identification of a heritable and stable cytoplasmic male sterility (CMS) mechanism. Hybrid breeding in WA can benefit from molecular marker, especially for the fertility restoration/sterility maintenance of the predominant A1-type of CMS. The major outcomes of this thesis are presented as follow: Mean yields of tall hybrids were 3 to 17% (ranging from 6 to 28 g m&#8722;2) higher than that of the local check across all 37 on-farm farmer-managed environments and were highest (1447%) averaged across the seven trials with the lowest mean yields. The yields of the new set of experimental hybrids were substantially superior to farmers local Guinea-race varieties, with 20 to 80% higher means over all hybrids in both low phosphorus (LP) and high phosphorus (HP) environments. Average mid-parent and better-parent heterosis estimates were respectively 78 and 48% under HP, and 75 and 42% under LP. Direct selection under LP was predicted to be 20 to 60% more effective than indirect selection under HP conditions, for hybrid performance under LP. The combining ability estimates provide initial insights into the potential benefit of germplasm from further east in West and Central Africa for developing a male parental pool that is distinct and complimentary to the Malian female pool. On chromosome SBI-05, we found a major A1 CMS fertility restorer locus (Rf5) explaining 19 and 14% of the phenotypic variation in either population. Minor quantitative trait loci (QTL) were detected in these two populations on chromosomes SBI-02, SBI-03, SBI-04 and SBI-10. In the third population, we identified one major A1 CMS fertility restorer locus on chromosome SBI-02, Rf2, explaining 31% of the phenotypic variation in the F2 mapping population. Pentatricopeptide repeat genes in the Rf2 QTL region were sequenced, and we detected in Sobic.002G057050 a missense mutation in the first exon, explaining 81% of the phenotypic variation in an F2:3 validation population and clearly separating B- from R-lines. The Guinea-race hybrids substantial yield superiorities over well adapted local Guinea-race varieties suggests that a strategy of breeding hybrids based on Guinea-germplasm can contribute to improving the livelihood of many smallholder farmers in WA. Although the usefulness of direct selection under LP for hybrid performance in the predominantly P-limited target environments was proven, companion evaluations of hybrids under HP would be desirable to identify also new hybrids that can respond to improved fertility conditions for sustainable intensification. The developed KASP marker stands as a promising tool for routine use in WA breeding programs.Die Nahrungsmittelversorgung und das Einkommen in den ländlichen Gebieten Westafrikas (WA) hängen stark von der lokalen Produktion, vor allem von der Wurzel- und Knollenpflanzen sowie der Getreideproduktion der Landwirte ab. Um eine ständig wachsende Bevölkerung in Anbetracht des Klimawandels und unter Anbaubedingungen mit geringem Produktionsmitteleinsatz zu ernähren, kann die Züchtung widerstandsfähiger Nutzpflanzen den Kleinbauern Ernährungssicherheit und Einkommen für eine nachhaltige ländliche Entwicklung garantieren. Die kleinwüchsigen Hybriden wurden in mehreren, von Landwirten geführten Ertragsversuchen auf landwirtschaftlichen Betrieben evaluiert und zeigten unter den Anbaubedingungen der Landwirte zufriedenstellende Getreideerträge und -qualität. Obwohl größeres, im Vergleich zu kürzerem Sorghum - dazu beitragen kann, das Risiko eines Rispenverlustes durch die Beweidung in Wanderweidewirtschaft gehaltenem Vieh zu verringern, gibt es keine Hinweise auf das Ertragspotenzial der hochwüchsigen Hybriden. Die Fortschritte, die ICRISAT und seine Partner bei der Hybridentwicklung erzielt haben, rechtfertigten den Aufbau eines langfristigen Hybridzuchtprogramms, um den Landwirten Hybriden mit ausreichenden Getreideerträgen und guter Getreidequalität bei geringem Produktionsmitteleinsatz zur Verfügung zu stellen. Der Mangel an quantitativen genetischen Informationen über den genetischen Wert neuer experimenteller Hybriden und ihrer Eltern (Guinea-Caudatum bis vollständiger Guinea Hintergrund, aus unterschiedlicher WA Herkunft) oder über die Effizienz alternativer Selektionsmethoden zur Ausrichtung der Ertragsleistung unter den überwiegend phosphorarmen Bedingungen mit geringem Produktionsmitteleinsatz behindert jedoch die Hybridentwicklung von Sorghum für diese Region. Die Sorghum-Hybridzüchtung war erst nach der Identifizierung eines vererbbaren und stabilen zytoplasmatischen männlichen Sterilisationsmechanismus (CMS) kommerziell möglich. Die Hybridzüchtung in WA kann von molekularen Markern, vor allem für die Fruchtbarkeitswiederherstellung/Sterilitätserhaltung des vorherrschenden A1 CMS Typs, profitieren. Die wichtigsten Ergebnisse dieser Arbeit werden wie folgt dargestellt: Die mittleren Erträge hoher Hybriden waren 3 bis 17% (im Bereich von 6 bis 28 g m-2) höher als die der lokalen Kontrollsorte in allen 37 von Landwirten verwalteten Umwelten und waren am höchsten (14-47%), gemittelt über die sieben Versuche mit den niedrigsten Durchschnittserträgen. Die Erträge der neuen, experimentellen Hybriden waren mit 20 bis 80% höheren Mittelwerten über alle Hybriden, wesentlich höher als die der lokalen Guinea-Rasse Sorten der Bauern. Sowohl in Umwelten mit niedrigem Phosphorgehalt (LP) als auch mit hohem Phosphorgehalt (HP). Die durchschnittlichen Schätzungen der Heterosis über das Elternmittel sowie über den besseren Elter lagen bei 78 bzw. 48% unter HP und 75 bzw. 42% unter LP. Es wurde berechnet, dass die direkte Selektion unter LP 20 bis 60% effektiver ist als die indirekte Selektion unter HP-Bedingungen für die Hybridleistung unter LP. Die Schätzung der Kombinationsfähigkeit liefern erste Erkenntnisse über den potenziellen Nutzen von Genmaterial aus weiter östlich gelegenen Gegenden West- und Zentralafrikas für die Entwicklung eines männlichen Elternpools, der sich vom malischen weiblichen Pool unterscheidet und ihn ergänzt. Auf dem Chromosom SBI-05 fanden wir einen großen A1 CMS Fertilitätswiederherstellungs-Locus (Rf5), der 19 und 14% der phänotypischen Variation in beiden Populationen erklärt. Regionen eines quantitativen Merkmals (QTL) mit geringem Effekt wurden in diesen beiden Populationen auf den Chromosomen SBI-02, SBI-03, SBI-04 und SBI-10 nachgewiesen. In der dritten Population identifizierten wir einen großen A1 CMS Fertilitätswiederherstellungs-Locus auf dem Chromosom SBI-02, Rf2, der 31% der phänotypischen Variation in der F2-Kartierungspopulation erklärt. Pentatricopeptid repeat Gene in der Rf2-QTL-Region wurden sequenziert, und wir entdeckten in Sobic.002G057050 eine sinnverändernde Punktmutation im ersten Exon, die 81% der phänotypischen Variation in einer F2:3-Validierungspopulation erklärt und B- von R-Linien klar trennt. Die erheblichen Ertragsüberlegenheiten der Guinea-Rasse Hybriden gegenüber gut angepassten lokalen Guinea-Rasse Arten deuten darauf hin, dass eine strategische Hybridzüchtung auf der Grundlage von Guinea-Keimmaterial zur Verbesserung der Lebensgrundlage vieler Kleinbauern in WA beitragen kann. Obwohl die Nützlichkeit der direkten Selektion unter LP für die Hybridleistung in den überwiegend P-begrenzten Zielumwelten etabliert wurde, wären Begleitbewertungen von Hybriden unter HP wünschenswert, um auch neue Hybride zu identifizieren, die auf verbesserte Fertilitätsbedingungen für eine nachhaltige Intensivierung reagieren können. Der entwickelte KASP-Marker steht als vielversprechendes Werkzeug für den routinemäßigen Einsatz in WA-Zuchtprogrammen bereit

Interaction of N with White-solidified Cast Iron Model Alloys: The Effect of Mn and Cu on the Formation of Fe and Si Nitrides

Surface remelting and subsequent nitriding improves the surface properties of cast irons. Upon remelting, a white-solidified surface layer forms, which contains coarse Si-free eutectic cementite (θ) and Si-enriched ferrite, pearlite or martensite in the intercarbidic regions between the eutectic θ. Nitriding produces a compound layer at the surface, which is composed of ε and γ’-iron (carbo)nitrides and enhances the corrosion resistance. Nitriding of white-solidified Fe-C-Si alloys, being model materials for remelted low-alloy ferritic cast irons, has shown that Si dissolved in α-Fe notably affects the formation of ε and γ’ in intercarbidic regions while Si simultaneously precipitates as amorphous nitride, X. Under process conditions only allowing for the formation of γ’ in pure Fe, Si dissolved in α-Fe promotes the formation of ε over the formation γ’, whereas Si-free eutectic θ transforms into nitride following the sequence θ → ε → γ’. The present work studies the nitriding of white-solidified Fe-3.5wt.%C-3wt.%-M alloys with additions of M = 1 wt.% Mn, 1 wt.% Cu or 1 wt.% Mn + 1 wt.% Cu, serving as model materials for remelted pearlitic cast irons. The presence of Mn and/or Cu causes notable deviations from the nitriding behavior known from Fe-C-Si alloys. Mn accelerates the precipitation of X in intercarbidic regions and obstructs the transformation of ε formed from Si-free θ into γ’. Cu promotes the formation of γ’ in Si-rich intercarbidic regions, surpassing the ε-promoting effect of Si

Lutte contre le VIH SIDA : commentaires sur les travaux de Nianguiry Kante

Nianguiry Kanté était un sociologue et directeur de recherche, précédemment affecté à l’ex Institut National de la Recherche en Santé Publique devenu Institut National de la Santé Publique aujourd’hui. Il a ensuite&nbsp; pris sa retraite à la toute nouvelle Université de Ségou, comme premier doyen de la Faculté des Sciences Sociales (FASSO) en décembre 2016. Doyen, comme l’appelait affectueusement ses étudiants, quittera ce monde le 13 Septembre 2021. Mais il ne le quittait pas vraiment car à titre d’exemple la Revue Africaine des Sciences Sociales (ISSN 1987-071X e-ISSN 1987-1023) dont il est l’initiateur a publié plus de 276 articles entre janvier 2010 et juin 2021 provenant d’une vingtaine de pays. En effet, cette journée mondiale de lutte contre le Sida (01 décembre) offre une autre occasion de parler du Professeur Nianguiry Kanté. L’un des domaines de recherche du Pr Kanté est la sociologie et l’anthropologie de la santé. En 2012, il a été membre fondateur du Congrès Panafricain des Anthropologues dont il était trésorier adjoint. Pour l’anthropologue, la santé constitue d’une certaine manière la marque sur les corps de façonnements sociaux, économiques, environnementaux, géopolitiques