STUDYING THE LOCAL DIVERSITY OF RURAL LIVELIHOODS SYSTEMS: AN APPLICATION OF TYPOLOGICAL TECHNIQUES FOR INTEGRATED RURAL DEVELOPMENT SUPPORT IN THE EASTERN CAPE (SOUTH AFRICA)

This paper presents briefly the principles and procedure of typology schemes, which aim at describing and representing the local diversity of rural households, through the analysis of their modes of operation, strategies and prospects, activities and livelihoods' systems. This approach departs from both strict economic analysis and social participatory approaches, which often overlook the diversity that exists among rural households at local level. It basically combines the respective principles and advantages of both approaches. Through a case study, which was carried out in a rural community of the Eastern Cape Province of South Africa, the paper highlights this local diversity, its representation through a typology scheme, and the issues related to livelihood systems: complementarity between on-farm and off-farm activities and sources of income, the key role of women, significance of subsistence farming activities, existence of productive and potentially profitable activities (wool). Some key questions for the close future are also raised: ageing process at household level (pensions are currently instrumental in livelihood build-up), transmission process to youngsters in a context of PTO land access system, sustainability of farming systems in a fragile and constraining natural environment, weaknesses in the agribusiness environment, basic needs in development support as expressed by people, the worrying situation of certain very poor households, problems and constraints as expressed by farmers. The paper finally discusses the significance of such tools for integrated rural development planning and management purposes. They may be responses to the increasing need for proper diagnosis, in a context of persistent poverty in South-Africa's rural areas and of public willingness to tackle it in an integrated manner.Community/Rural/Urban Development, Labor and Human Capital,

Poverty and livelihoods in rural South Africa: Investigating diversity and dynamics of livelihoods. Case studies in Limpopo

Food Security and Poverty,

Bosonic Quartic Couplings at LEP2

We list the set of C and P conserving anomalous quartic vector bosons self-couplings which can be tested at LEP2 through triple vector boson production. We show how this set can be embedded in manifestly SU(2)xU(1) gauge invariant operators exhibiting an SU(2)_c global symmetry. We derive bounds on these various couplings and show the most relevant distributions that can enhance their contribution. We also find that an e+e- collider running at 500 GeV can improve the LEP2 limits by as much as three orders of magnitude.Comment: 21 pages, 7 figure

Evolution of the mass, size, and star formation rate in high-redshift merging galaxies MIRAGE - A new sample of simulations with detailed stellar feedback

We aim at addressing the questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1<z<2. A consequent fraction of Milky Way like galaxies are thought to have undergone an unstable clumpy phase at this early stage. Using the adaptive mesh refinement code RAMSES, with a recent physically-motivated implementation of stellar feedback, we build the Merging and Isolated high-Redshift Adaptive mesh refinement Galaxies (MIRAGE) sample. It is composed of 20 mergers and 3 isolated idealized disks simulations with global physical properties in accordance with the 1<z<2 mass complete sample MASSIV. The numerical hydrodynamical resolution reaches 7 parsecs in the smallest Eulerian cells. Our simulations include: star formation, metal line cooling, metallicity advection, and a recent implementation of stellar feedback which encompasses OB-type stars radiative pressure, photo-ionization heating, and supernovae. The initial conditions are set to match the z~2 observations, thanks to a new public code DICE. The numerical resolution allows us to follow the formation and evolution of giant clumps formed in-situ from Jeans instabilities triggered by high initial gas fraction. The star formation history of isolated disks shows stochastic star formation rate, which proceeds from the complex behavior of the giant clumps. Our minor and major gas-rich merger simulations do not trigger starbursts, suggesting a saturation of the star formation in a turbulent and clumpy interstellar medium fed by substantial accretion from the circum-galactic medium. Our simulations are close to the normal regime of the disk-like star formation on a Schmidt-Kennicutt diagram. The mass-size relation and its rate of evolution matches observations, suggesting that the inside-out growth mechanisms of the stellar disk do not necessarily require to be achieved through a cold accretion.Comment: 18 pages, 12 figures. Accepted in A&

Long-term low-dose ketoconazole treatment in bilateral macronodular adrenal hyperplasia

Medical therapy for Cushing's syndrome due to bilateral macronodular adrenal hyperplasia (BMAH) is generally administered for a limited time before surgery. Aberrant receptors antagonists show inconsistent efficacy in the long run to prevent adrenalectomy. We present a patient with BMAH, treated for 10 years with low doses of ketoconazole to control cortisol secretion. A 48-year-old woman presented with headaches and hypertension. Investigations showed the following: no clinical signs of Cushing's syndrome; enlarged lobulated adrenals; normal creatinine, potassium, and aldosterone; normal urinary aldosterone and metanephrines; elevated urinary free cortisol and steroid metabolites; and suppressed plasma renin activity and ACTH. A screening protocol for aberrant adrenal receptors failed to show any illegitimate hormone dependence. Ketoconazole caused rapid normalisation of cortisol and ACTH that persists over 10 years on treatment, while adrenals show no change in shape or size. Ketoconazole decreases cortisol in patients with Cushing's syndrome, and may prevent adrenal overgrowth. Steroid secretion in BMAH is inefficient as compared with normal adrenals or secreting tumours and can be controlled with low, well-tolerated doses of ketoconazole, as an alternative to surgery. LEARNING POINTS: Enlarged, macronodular adrenals are often incidentally found during the investigation of hypertension in patients harboring BMAH. Although laboratory findings include low ACTH and elevated cortisol, the majority of patients do not display cushingoid features.Bilateral adrenalectomy, followed by life-long steroid replacement, is the usual treatment of this benign condition, and alternative medical therapy is sought. Therapy based on aberrant adrenal receptors gives disappointing results, and inhibitors of steroidogenesis are not always well tolerated.However, ketoconazole at low, well-tolerated doses appeared appropriate to control adrenal steroid secretion indefinitely, while preventing adrenal overgrowth. This treatment probably constitutes the most convenient long-term alternative to surgery

Simultaneous multi-band detection of Low Surface Brightness galaxies with Markovian modelling

We present an algorithm for the detection of Low Surface Brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. To assess the robustness of our method, the method was applied to a set of 18 B and I band images (covering 1.3 square degrees in total) of the Virgo cluster. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (i) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (ii) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered ~20% more mock LSB galaxies and ~40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is reached for sources with r_e > 3" at a mean surface brightness level of mu_g=27.7 mag/arcsec^2 and a central surface brightness of mu^0 g=26.7 mag/arcsec^2. About 10% of the false positives are artifacts, the rest being background galaxies. We have found our method to be complementary to the application of matched filters and an optimized use of SExtractor, and to have the following advantages: it is scale-free, can be applied simultaneously to several bands, and is well adapted for crowded regions on the sky.Comment: 39 pages, 18 figures, accepted for publication in A

Etude du comportement mécanique d'un liner de titane

National audienceIl s'agit dans ce travail d'étudier le comportement mécanique d'un liner constitué de titane T35, fourni sous la forme de feuillard de 300 μm d'épaisseur. Ce travail porte notamment sur la caractérisation du métal de base mais aussi sur celui des cordons de soudure.. Pour le matériau de base, les observations microstructurales ont révélé des grains équiaxes avec une texture classique de tôle laminée pour les matériaux hexagonaux. Les soudures montrent une microstructure moins régulière et une texture plus isotrope. D'un point de vue comportement mécanique, nous avons pu identifier au moyen d'essais de traction un comportement élastoviscoplastique anisotrope des tôles. Ces résultats expérimentaux ont permis l'identification de 3 modèles issus de la littérature, (Mises, Hill et Bron-Besson) donnant lieu à des comparaisons de simulation. Enfin une analyse tomographique réalisée à l'ESRF sur une éprouvette fissurée a révélée la présence de peu de cavités à proximité de la fissure

GHASP: an Hα\alpha kinematic survey of spiral galaxies - X. Surface photometry, decompositions and the Tully-Fisher relation in the Rc-band

We present Rc-band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution Fabry-Perot H{\alpha} maps have previously been obtained. Our data set is constructed by new Rc-band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include Rc-band surface brightness profiles for 170 galaxies and $ugriz$ profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -- magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminosities, sizes and maximum velocities. We determine the Rc-band Tully Fisher relation using maximum velocities derived solely from H$\alpha$ rotation curves for a sample of 80 galaxies, resulting in a slope of $-8.1 \pm 0.5$, zero point of $-3.0 \pm 1.0$ and an estimated intrinsic scatter of $0.28 \pm 0.07$. We note that, different from the TF-relation in the near-infrared derived for the same sample, no change in the slope of the relation is seen at the low-mass end (for galaxies with $V_{max} < 125$ km/s). We suggest that this different behaviour of the Tully Fisher relation (with the optical relation being described by a single power-law while the near-infrared by two) may be caused by differences in the stellar mass to light ratio for galaxies with $V_{max} < 125$ km/s.Comment: 17 pages, 11 figure

Détermination pratique de quelques espèces de convolvulacées, adventices de l'Afrique du Centre et de l'Ouest

Détermination pratique de quelques espèces de convolvulacées, adventices de l'Afrique du Centre et de l'Ouest. Les auteurs décrivent une clé d'identification utilisant uniquement des critères végétatifs pour 22 espèces de Convolvulaceae, adventices des cultures en Afrique du Contre et de l'Ouest. Elle est accompagnée d'une liste des synonymes usuels pour chaque espèce, d'un tableau des caractères végétatifs des espèces volubiles, d'un texte de description et de planches. Ces éléments permettent la détermination des adventices au stade végétatif à partir de caractères visibles et facilement repérables, ne nécessitant pus une formation de botaniste. (Résumé d'auteur