Collecting groundnut (Arachis hypogaea L.) germplasm in Mali

In October, 1986, a collecting mission organized jointly by ICRISAT and the Institut d'Economie Rurale, Bamako, in Mali obtained 146 samples representing erect, spreading bunch and runner types belonging to A. hypogaea vars. hypogaea, vulgaris and, possibly, fastigiata. Most of the samples were of old landraces and exhibited wide variation for pod type, seed size and seed colour. Evidence of genetic erosion was detected, particularly among late maturing runner types

Glucocorticoids modulate human brown adipose tissue thermogenesis in vivo

Introduction: Brown adipose tissue (BAT) is a thermogenic organ with substantial metabolic capacity and has important roles in the maintenance of body weight and metabolism. Regulation of BAT is primarily mediated through the ß-adrenoceptor (ß-AR) pathway. The in vivo endocrine regulation of this pathway in humans is unkown. The objective of our study was to assess the in vivo BAT temperature responses to acute glucocorticoid administration. Methods: We studied 8 healthy male volunteers, not pre-selected for BAT presence or activity and without prior BAT cold-activation, on two occasions, following an infusion with hydrocortisone (0.2 mg.kg-1.min-1 for 14 hours) and saline, respectively. Infusions were given in a randomized double-blind order. They underwent assessment of supraclavicular BAT temperature using infrared thermography following a mixed meal, and during ß-AR stimulation with isoprenaline (25 ng.kg fat-free mass-1.min-1 for 60 min) in the fasting state. Results: During hydrocortisone infusion, BAT temperature increased both under fasting basal conditions and during ß-AR stimulation. We observed a BAT temperature threshold, which was not exceeded despite maximal ß-AR activation. We conclude that BAT thermogenesis is present in humans under near-normal conditions. Glucocorticoids modulate BAT function, representing important physiological endocrine regulation of body temperature at times of acute stress

Adipocyte-specific glucocorticoid inactivation protects against diet-induced obesity

Local glucocorticoid (GC) action depends on intracellular GC metabolism by 11β-hydroxysteroid dehydrogenases (11βHSDs). 11βHSD1 activates GCs, while 11βHSD2 inactivates GCs. Adipocyte-specific amplification of GCs through transgenic overexpression of 11βHSD1 produces visceral obesity and the metabolic syndrome in mice. To determine whether adipocyte-specific inactivation of GCs protects against this phenotype, we created a transgenic model in which human 11βHSD2 is expressed under the control of the murine adipocyte fatty acid binding protein (aP2) promoter (aP2-h11βHSD2). Transgenic mice have increased 11βHSD2 expression and activity exclusively in adipose tissue, with the highest levels in subcutaneous adipose tissue, while systemic indexes of GC exposure are unchanged. Transgenic mice resist weight gain on high-fat diet due to reduced fat mass accumulation. This improved energy balance is associated with decreased food intake, increased energy expenditure, and improved glucose tolerance and insulin sensitivity. Adipose tissue gene expression in transgenic mice is characterized by decreased expression of leptin and resistin and increased expression of adiponectin, peroxisome proliferator–activated receptor γ, and uncoupling protein 2. These data suggest that reduction of active GCs exclusively in adipose tissue is an important determinant of a favorable metabolic phenotype with respect to energy homeostasis and the metabolic syndrome

11β-HSD1 modulates the set point of brown adipose tissue response to glucocorticoids in male mice

Glucocorticoids (GCs) are potent regulators of energy metabolism. Chronic GC exposure suppresses brown adipose tissue (BAT) thermogenic capacity in mice, with evidence for a similar effect in humans. Intracellular GC levels are regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity, which can amplify circulating GC concentrations. Therefore, 11β-HSD1 could modulate the impact of GCs on BAT function. This study investigated how 11β-HSD1 regulates the molecular architecture of BAT in the context of GC excess and aging. Circulating GC excess was induced in 11β-HSD1 knockout (KO) and wild-type mice by supplementing drinking water with 100 μg/mL corticosterone, and the effects on molecular markers of BAT function and mitochondrial activity were assessed. Brown adipocyte primary cultures were used to examine cell autonomous consequences of 11β-HSD1 deficiency. Molecular markers of BAT function were also examined in aged 11β-HSD1 KO mice to model lifetime GC exposure. BAT 11β-HSD1 expression and activity were elevated in response to GC excess and with aging. 11β-HSD1 KO BAT resisted the suppression of uncoupling protein 1 (UCP1) and mitochondrial respiratory chain subunit proteins normally imposed by GC excess. Furthermore, brown adipocytes from 11β-HSD1 KO mice had elevated basal mitochondrial function and were able to resist GC-mediated repression of activity. BAT from aged 11β-HSD1 KO mice showed elevated UCP1 protein and mitochondrial content, and a favorable profile of BAT function. These data reveal a novel mechanism in which increased 11β-HSD1 expression, in the context of GC excess and aging, impairs the molecular and metabolic function of BAT

Contribution of an innovation platform to change the management of collective irrigation: a case study from the Office du Niger (Mali)

In the Office du Niger large rice farming irrigation scheme in Mali, water management has been a permanent source of tension between the smallholder tenants and the administration. The transfer of tertiary canal maintenance to the tenant farmers was expected to improve water management but, in practice, that rather led to deterioration. An innovation platform, erected by the CoS-SIS (Convergence of Sciences – Strengthening Innovation Systems) Program, reached a consensual agreement to transfer the maintenance of tertiary canals to the tenant producers, and updated the Contrat Plan expropriation rules for failure to pay water fees as well as many other key dispositions ruling duties and responsibilities for all parties: farmers, Office du Niger agents and the State

Looking at agricultural innovation platforms through an innovation champion lens. An analysis of three cases in West Africa

The concept of an innovation platform is increasingly used in interventions inspired by agricultural innovation systems thinking, as a way of bringing stakeholders from a sector together to enable transformative change. An essential role on such innovation platforms is thought to be that of the ‘innovation champion’, but this role has so far not been unravelled. In this paper, by applying insights from management science to analyse three innovation platforms in West Africa from the Convergence of Sciences – Strengthening Innovation Systems programme (CoS–SIS), different types of innovation champions are mapped. The authors conclude that making a distinction among different types of innovation champions can be useful in identifying members for innovation platforms, but that the specifics of agricultural innovation appear not to be adequately captured by roles attributed to existing categories of innovation champions. Further research is needed to ascertain whether other categories exist, and how different innovation champions interact over time on agricultural innovation platforms

Choice-making in facilitation of agricultural innovation platforms in different contexts in West Africa: experiences from Benin, Ghana and Mali

Platforms provide an increased capacity for learning and coordinated innovation. The value of platforms for innovation is widely recognized, but more understanding is needed of the choices made in facilitation, to enable platforms to perform effectively within varying value chain contexts. This paper applies a comparative case study analysis of four innovation platforms in West Africa that aim to create institutional change for the benefit of smallholders. Each institutional context (emerging or developing value chain, a well-established value chain with more or less distortion by politics and rent-seeking behaviour) constituted a specific type of constraint and required different facilitation choices. Comparison showed that it is imperative for facilitators to have a clear platform purpose and design criteria, and good situation and actor analyses, and to interactively design small platforms, fit to create institutional change in a given context. Platforms need actors with capacities relating to the issue at stake, but also communicative qualities. Then there are situational facilitation choices: local level platforms need more structuring of deliberation, data-gathering, networking, and advocacy than higher level platforms. However, what emerged as essential for all was delicate mediation and dynamic agenda-setting. This created trust, relationships, and momentum for mutually supportive team action and institutional change