Characterization and Cradiovascular Effects of (13S)-9α,13α-epoxylabda-6β(19),15(14)diol dilactone, a Diterpenoid Isolated from Leonotis leonurus

A new diterpenoid, (13S)-9 ,13 -epoxylabda-6 (19),15(14)diol dilactone (1), was isolated from Leonotis leonurus and the structure determined via NMR analysis. The compound causes significant changes in blood pressure of anaesthetized normotensive rats and exhibits a negative chronotropic effect.Web of Scienc

How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables

1. Demographic rates are shaped by the interaction of past and current environments that individuals in a population experience. Past environments shape individual states via selection and plasticity, and fitness-related traits (e.g., individual size) are commonly used in demographic analyses to represent the effect of past22 environments on demographic rates. 2. We quantified how well the size of individuals captures the effects of a population’s past and current environments on demographic rates in a well-studied experimental system of soil mites. We decomposed these interrelated sources of variation with a novel method of multiple regression that is useful for understanding nonlinear relationships between responses and multicollinear explanatory variables. We graphically present the results using area-proportional Venn diagrams. Our novel method was developed by combining existing methods and expanding upon them. 3. We showed that the strength of size as a proxy for the past environment varied widely among vital rates. For instance, in this organism with an income breeding life-history, the environment had more effect on reproduction than individual size, but with substantial overlap indicating that size encompassed some of the effects of the past environment on fecundity. 4. This demonstrates that the strength of size as a proxy for the past environment can vary widely among life-history processes within a species, and this variation should be taken into consideration in trait-based demographic or individual-based approaches that focus on phenotypic traits as state variables. Furthermore, the strength of a proxy will depend on what state variable(s) and what demographic rate is being examined; i.e., different measures of body size (e.g., length, volume, mass, fat stores) will be better or worse proxies for various life-history processes

Eco-evolutionary dynamics. Experiments in a model system

Understanding the consequences of environmental change on both long- and short-term ecological and evolutionary dynamics is a basic pre-requisite for any effective conservation or management programme but inherently problematic because of the complex interplay between ecological and evolutionary processes. Components of such complexity have been described in isolation or within conceptual models on numerous occasions. What remains lacking are studies that characterise effectively the coupled ecological and evolutionary dynamics, to demonstrate feedback mechanisms that influence both phenotypic change, and its effects on population demography, in organisms with complex life histories. We present a systems-based approach that brings together multiple effects that 'shape' an organism's life history (e.g. direct and delayed life-history consequences of environmental variation) and the resulting eco-evolutionary population dynamics. Using soil mites in microcosms, we characterise ecological, phenotypic and evolutionary dynamics in replicated populations in response to experimental manipulations of environment (e.g. the competitive environment, female age, male quality). Our results demonstrate that population dynamics are complex and are affected by both plastic and evolved responses to past and present environments, and that the emergent population dynamic itself shaped the landscape for natural selection to act on in subsequent generations. Evolutionary and ecological effects on dynamics can therefore be almost impossible to partition, which needs to be considered and appreciated in research, management and conservation. © 2014 Elsevier Ltd

Ontogenetic trajectories of body coloration reveal its function as a multicomponent nonsenescent signal

The understanding of developmental patterns of body coloration is challenging because of the multicomponent nature of color signals and the multiple selective pressures acting upon them, which further depend on the sex of the bearer and area of display. Pigmentary colors are thought to be strongly involved in sexual selection, while structural colors are thought to generally associate with conspecifics interactions and improve the discrimination of pigmentary colors. Yet, it remains unclear whether age dependency in each color component is consistent with their potential function. Here, we address lifelong ontogenetic variation in three color components (i.e. UV, pigmentary, and skin background colors) in a birth cohort of common lizards Zootoca vivipara across three ventral body regions (i.e. throat, chest, and belly). All three color components developed sexual dichromatism, with males displaying stronger pigmentary and UV colors but weaker skin background coloration than females. The development of color components led to a stronger sexual dichromatism on the concealed ventral region than on the throat. No consistent signs of late‐life decay in color components were found except for a deceleration of UV reflectance increase with age on the throat of males. These results suggest that body color components in common lizards are primarily nonsenescent sexual signals, but that the balance between natural and sexual selection may be altered by the conspicuousness of the area of display. These results further support the view that skin coloration is a composite trait constituted of multiple color components conveying multiple signals depending on age, sex, and body location

Determination of kanamycin plasma levels using LC-MS and its pharmacokinetics in patients with multidrug-resistant tuberculosis with and without HIV-infection

The objectives of the study were: (1) to determine kanamycin plasma concentrations using liquid chromatography coupled with mass spectrometry (LC-MS), (2) to investigate kanamycin pharmacokinetics (PK) in patients with multi-drug resistant tuberculosis (MDR-TB), (3) to find out whether HIV infection, kidney dysfunction and antiretroviral drugs influence kanamycin PK. The study was designed as a non-randomized study involving male and female HIV- positive and HIVnegative patients admitted for MDR-TB treatment. Blood samples were collected before (baseline) and ½, 1, 2, 4, 8 and 24 hours after intramuscular injection of kanamycin. LC-MS was used to quantify kanamycin plasma concentrations. Thirty one patients including 13 HIV (+) participated in the study. The lower limit of detection and lower limit of quantification of kanamycin were 0.06 μg/ml and 0.15 μg/ml respectively. Kanamycin PK parameters were described and there was no significant difference between HIV-positive and HIV-negative patients. A statistical significant difference (p=0.0126) was found in the renal function in HIV - positive and HIV - negative patients. However, this difference did not affect kanamycin elimination. No interactions have been identified between antiretroviral drugs and kanamycin. Conclusion: LC-MS analysis method is highly specific and highly sensitive in the detection and quantification of kanamycin plasma concentrations. Kanamycin PK in patients with MDR-TB was described. Due to a limited number of patients, we cannot rule out any influence of HIV - infection, renal impairment and antiretroviral drugs on kanamycin pharmacokinetics. The relationship between the area under the curve of kanamycin free plasma concentrations (fAUC) and its minimum inhibitory concentrations (MIC) on M.tuberculosis isolated from the sputum of each patient should be assessed. Therefore, kanamycin free plasma concentrations and MIC should be determined.Web of Scienc

Prevalence of Kidney Disease in HIV-Infected and Uninfected Rwandan Women

Background: In the United States, HIV-related kidney disease disproportionately affects individuals of African descent; however, there are few estimates of kidney disease prevalence in Africa. We evaluated the prevalence of kidney disease among HIV-infected and uninfected Rwandan women. Methods: The Rwandan Women's Interassociation Study and Assessment prospectively enrolled 936 women. Associations with estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m$^2$ and proteinuria were assessed in separate logistic regression models. Results: Among 891 non-pregnant women with available data, 2.4% had an eGFR<60 mL/min/1.73 m$^2$ (calculated by the Modification of Diet in Renal Disease equation, MDRD eGFR) and 8.7% had proteinuria $\ge$1+. The prevalence of decreased eGFR varied markedly depending on the estimating method used, with the highest prevalence by Cockcroft-Gault. Regardless of the method used to estimate GFR, the proportion with decreased eGFR or proteinuria did not differ significantly between HIV-infected and -uninfected women in unadjusted analysis. After adjusting for age and blood pressure, HIV infection was associated with significantly higher odds of decreased MDRD eGFR but not proteinuria. Conclusion: In a well-characterized cohort of Rwandan women, HIV infection was associated with decreased MDRD eGFR. The prevalence of decreased eGFR among HIV-infected women in our study was lower than that previously reported in African-Americans and in other Central and East African HIV populations, although there was substantial variability depending on the equation used to estimate GFR. Future studies are needed to optimize GFR estimates and to determine the impact of antiretroviral therapy on kidney disease in this population

PARTNERSHIPS IN HIGHLANDS OF RWANDA UNDER INTEGRATED AGRICULTURAL RESEARCH FOR DEVELOPMENT (IAR4D) ARRANGEMENTS

The Integrated Agricultural Research for Development (IAR4D) concept was proposed to respond to the failures of Agriculture Research and Development (ARD) systems in Sub-Saharan Africa. The key element of implementation and success of IAR4D was action sites called agricultural Innovation Platform (IPs) and their counterfactual sites. Social Network Analysis (SNA) is used to explain social relationships and partnerships. This study explored the patterns of agricultural partnerships among stakeholders in the highlands of Rwanda under IAR4D. Data were collected in action sites that included Mudende, Gataraga, Remera and Rwerere; and in their counterpart counterfactual sites that comprised of Bigogwe, Nyange and Gacaca. Results showed that in action sites, stakeholders were linked to different and diversified partners. Furthermore, many stakeholders were connected to several partners through agricultural partnerships, hence creating complex social networks with high density and degree of distribution. In the counterfactual sites, however, stakeholders were exclusively linked to the same kind of partners, and one stakeholder was connected to one partner through probably non-agricultural partnerships. These facts demonstrated that IAR4D created dense interfaces, significantly improved the networking system, and delivered technologies and innovations.Le concept de Recherche Agricole Int\ue9gr\ue9e pour le D\ue9veloppement (IAR4D) a \ue9t\ue9 propos\ue9 comme solution aux \ue9checs des syst\ue8mes Recherches Agricoles et D\ue9veloppement (ARD) en Afrique Sub-Saharienne. L\u2019\ue9l\ue9ment principal de la r\ue9ussite et du succ\ue8s d\u2019IAR4D \ue9tait l\u2019\ue9tablissement des sites d\u2019action appel\ue9s Plateformes Agricoles d\u2019innovation (IPs) ainsi que leurs sites t\ue9moins. L\u2019analyse du R\ue9seau Sociale (SNA) est utilis\ue9e pour expliquer les rapports et les relations sociaux des acteurs et des partenaires. La pr\ue9sente \ue9tude avait pour objectif d\u2019explorer les structures des relations socio-agricoles parmi les acteurs et les partenaires dans les hautes altitudes du Rwanda soumises \ue0 l\u2019IAR4D. Les donn\ue9es ont \ue9t\ue9 r\ue9colt\ue9es dans les sites d\u2019action comprenant\ua0: Mudende, Gataraga, Remera et Rwerere ainsi que dans leurs contreparties sites t\ue9moins incluant Bigogwe, Nyange et Gacaca. Les r\ue9sultats ont montr\ue9 que dans les sites d\u2019action, les acteurs \ue9taient associ\ue9s aux partenaires de natures diff\ue9rentes et un acteur \ue9tait li\ue9 \ue0 plusieurs partenaires a la fois. Dans les sites t\ue9moins par contre, les acteurs \ue9taient li\ue9s aux partenaires de m\ueames natures que ceux-ci et un acteur \ue9tait rarement li\ue9 \ue0 plus de deux partenaires. Ces faits ont montr\ue9 que l\u2019IAR4D a cr\ue9e un r\ue9seau socio-agricole tr\ue8s dense et sophistiqu\ue9 et ainsi a consid\ue9rablement am\ue9lior\ue9 le r\ue9seau socio-agricole. Par cons\ue9quent, l\u2019IAR4D peut \ueatre recommand\ue9 pour le transfert the technologies and des innovations agricoles

ADOPTION OF SOIL CONSERVATION THROUGH COLLECTIVE ACTIONS IN SOUTHWESTERN UGANDA

In developing countries, access to and use of renewable natural resources are essential for rural livelihoods to thrive. Hence, cooperation in the management of natural resources is increasingly an important strategy that can enhance long-term socio-ecological resilience. In most cases, collective actions have widely been recognised as an alternative institutional arrangement to centralised governance for the management of natural resources, but their success largely depends on factors that are specific to localities where they are implemented. In this study, factors that influence adoption and extent of adoption of natural resource conservation activities were identified using two case studies: Bubaare and Bufundi Innovation Platforms in Uganda. The drivers of adoption of community natural resource management strategies are analysed using an Ordered Logit Model while extent of adoption is analysed using a truncated regression model. The education level of a household head, membership in collective action group, and perception of plot slope and relevance of bye-laws were factors associated with likelihood of adoption. Value of livestock, membership in collective action group, access to credit and off-farm income were found to positively influence the level of investment. Thus, collective action increases opportunities for adoption; hence farmers should be supported to work collectively.Dans les pays en voie de d\ue9veloppement, l\u2019acc\ue8s et l\u2019utilisation des ressources naturelles sont essentiels pour la suivie en mileu rural et pour y prosp\ue9rer. Ainsi, la coop\ue9ration dans la gestion des ressources naturelles est de plus en plus une strat\ue9gie importante qui peut am\ue9liorer \ue0 long terme la coh\ue9sion socio-\ue9cologique. Dans beaucoup de cas; les actions collectives ont \ue9t\ue9 largement reconnues comme une alternative d\u2019organisation institutionnelle pour centraliser la gouvernance de la gestion des ressources naturelles, mais leur succ\ue8s d\ue9pend largement des facteurs qui sont sp\ue9cifiques aux milieux o\uf9 elles sont mise en oeuvre. Dans cette \ue9tude, les facteus qui influencent l\u2019adoption et le degr\ue9 d\u2019adoption des activit\ue9s de conservation des ressources naturelles \ue9taient identifi\ue9s en utilisant deux cas d\u2019\ue9tude: Les Plate-formes d\u2019Innovation de Bubaare et Bufundi en Ouganda. Les forces motrices d\u2019adoption des strategies de gestion des ressources naturelles communautaires sont analys\ue9es en utilsant un mod\ue8le Logit Ordonn\ue9 tandis que le degr\ue9 d\u2019adoption est analys\ue9 en utilisant un mod\ue8le de r\ue9gression tronqu\ue9. Le niveau d\u2019\ue9ducation du chef de m\ue9nage, l\u2019appartenance au groupe d\u2019action collective, et la perception de la pente de la parcelle et limportance des arr\ueat\ue9s \ue9taient les facteurs associ\ue9s au taux d\u2019adoption. La value du b\ue9tail, l\u2019appartenance au groupe d\u2019action collective, l\u2019acc\ue8s au cr\ue9dit et le revenu non- agricole \ue9taient les facteurs qui influencent positivement le niveau d\u2019investissement. Donc, les actions collectives augmentent les opportunit\ue9s pour l\u2019adoption; ainsi les producteurs devraient \ueatre encourag\ue9s \ue0 travailler de fa\ue7con collective