95 research outputs found
Importance, impacts de lâutilisation et gestion rationnelle du satrana ou Hyphaene coriacea Gaertn. (Arecaceae) prĂšs de la baie de Rigny, Antsiranana (Madagascar)
Hyphaene coriacea is a useful palm in tropical Africa which also grows in the grasslands of western Madagascar. A study was conducted on the importance of this species in handcrafts and the ecological impacts in three Fokontany around the Baie de Rigny. Ethnobotanical surveys were conducted with women aged between 14 and 70 years old who commonly created baskets, from the collection of leaves until the sale of the finished products. The evaluation of human activities on the production of H. coriacea leaves was conducted by counting leaves produced by 175 palm trees subjected to different sampling conditions during one year. On average, one person collects 120 to 160 leaves, produces 60 to 80 baskets and earns 43,200 Ariary per month. The collection of the leaves contributes to sustainable management by using special tools and practices during collection such as not completely cutting down palms. However, collection of leaves  negatively impacts production of leaves by reducing their number. Rotating leaf collection, restricting the number of leaves collected on each individual per year, and protection of the vegetation against brush fires are strongly advised while respecting the management techniques already in use. Hyphaene coriacea, un palmier dâAfrique tropicale, pousse dans les formations herbeuses de la partie occidentale de Madagascar. Une Ă©tude sur lâimportance de cette espĂšce pour la vannerie ainsi que lâimpact de son utilisation a Ă©tĂ© effectuĂ©e dans trois Fokontany Ă la pĂ©riphĂ©rie de la baie de Rigny. Des enquĂȘtes ethnobotaniques ont Ă©tĂ© menĂ©es auprĂšs de femmes ĂągĂ©es de 14 Ă 70 ans sur la pratique de la vannerie, de la collecte des feuilles Ă la vente des produits finis. Les impacts de lâactivitĂ© humaine sur la production de feuilles de H. coriacea ont Ă©tĂ© mesurĂ©s Ă partir du nombre de feuilles produites par 175 palmiers soumis Ă des niveaux de prĂ©lĂšvement diffĂ©rents pendant une annĂ©e. En moyenne, une personne collecte mensuellement de 120 Ă 160 feuilles, fabrique 60 Ă 80 paniers et gĂ©nĂšre un revenu de 43.200 Ariary. La collecte de ces feuilles de palmier est menĂ©e dans le cadre dâune gestion rationnelle car elle est rĂ©alisĂ©e avec un outil adaptĂ© et elle profite de lâinterdiction dâabattre les palmiers. Le mode de collecte a cependant un impact nĂ©gatif sur la production de feuilles en diminuant leur nombre. La rotation de la collecte de feuilles, la limitation du nombre de feuilles prĂ©levĂ©es sur chaque individu pendant une annĂ©e (28,4%) et la protection de la vĂ©gĂ©tation contre les feux de brousses sont vivement recommandĂ©es, tout en respectant les techniques positives qui sont dĂ©jĂ pratiquĂ©es
SHRIMP U-Pb zircon geochronology of southern Madagascar: New evidence of Mesoarchaean crust and its implications on Madagascar tectonothermal history
珏3ćæ„”ćç§ćŠă·ăłăăžăŠă /珏32ćæ„”ćć°ćŠă·ăłăăžăŠă 11æ30æ„ïŒéïŒ ç”±èšæ°çç 究æ ïŒéă»ăăăŒ
Dog ecology and demography in Antananarivo, 2007
<p>Abstract</p> <p>Background</p> <p>Rabies is a widespread disease in African domestic dogs and a serious public health problem in developing countries. Canine rabies became established in Africa during the 20th century, coinciding with ecologic changes that favored its emergence in canids.</p> <p>This paper reports the results of a cross-sectional study of dog ecology in the Antananarivo urban community in Madagascar.</p> <p>A questionnaire survey of 1541 households was conducted in Antananarivo from October 2007 to January 2008. The study addressed both owned and unowned dogs. Various aspects of dog ecology were determined, including size of dog population, relationship between dogs and humans, rabies vaccination.</p> <p>Results</p> <p>Dog ownership was common, with 79.6 to 94.1% (mean 88.9%) of households in the six arrondissements owning dogs. The mean owned dog to person ratio was 1 dog per 4.5 persons and differed between arrondissements (administrative districts), with ratios of 1:6.0 in the first arrondissement, 1:3.2 persons in the 2<sup>nd</sup>, 1:4.8 in the 3<sup>rd</sup>, 1:5.2 in the 4<sup>th</sup>, 1:5.6 in the 5<sup>th </sup>and 1:4.4 in the 6<sup>th </sup>arrondissement. Overall, there were more male dogs (61.3%) and the male/female sex ratio was estimated to be 1.52; however, mature females were more likely than males to be unowned (OR: 1.93, CI 95%; 1.39<OR<2.69). Most (79.1%) owned dogs were never restricted and roamed freely to forage for food and mix with other dogs. Only a small proportion of dogs (11.7%) were fed with commercial dog food. Only 7.2% of owned dogs had certificates confirming vaccination against rabies. The proportion of vaccinated dogs varied widely between arrondissements (3.3% to 17.5%).</p> <p>Conclusion</p> <p>Antananarivo has a higher density of dogs than many other urban areas in Africa. The dog population is unrestricted and inadequately vaccinated against rabies. This analysis of the dog population will enable targeted planning of rabies control efforts.</p
Igneous sapphirine in Ambatomena, southern Madagascar
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Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment
The Deep Underground Neutrino Experiment (DUNE) will produce world-leading
neutrino oscillation measurements over the lifetime of the experiment. In this
work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in
the neutrino sector, and to resolve the mass ordering, for exposures of up to
100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed
uncertainties on the flux prediction, the neutrino interaction model, and
detector effects. We demonstrate that DUNE will be able to unambiguously
resolve the neutrino mass ordering at a 3 (5) level, with a 66
(100) kt-MW-yr far detector exposure, and has the ability to make strong
statements at significantly shorter exposures depending on the true value of
other oscillation parameters. We also show that DUNE has the potential to make
a robust measurement of CPV at a 3 level with a 100 kt-MW-yr exposure
for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2.
Additionally, the dependence of DUNE's sensitivity on the exposure taken in
neutrino-enhanced and antineutrino-enhanced running is discussed. An equal
fraction of exposure taken in each beam mode is found to be close to optimal
when considered over the entire space of interest
A Gaseous Argon-Based Near Detector to Enhance the Physics Capabilities of DUNE
This document presents the concept and physics case for a magnetized gaseous argon-based detector system (ND-GAr) for the Deep Underground Neutrino Experiment (DUNE) Near Detector. This detector system is required in order for DUNE to reach its full physics potential in the measurement of CP violation and in delivering precision measurements of oscillation parameters. In addition to its critical role in the long-baseline oscillation program, ND-GAr will extend the overall physics program of DUNE. The LBNF high-intensity proton beam will provide a large flux of neutrinos that is sampled by ND-GAr, enabling DUNE to discover new particles and search for new interactions and symmetries beyond those predicted in the Standard Model
Snowmass Neutrino Frontier: DUNE Physics Summary
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment with a primary physics goal of observing neutrino and antineutrino oscillation patterns to precisely measure the parameters governing long-baseline neutrino oscillation in a single experiment, and to test the three-flavor paradigm. DUNE's design has been developed by a large, international collaboration of scientists and engineers to have unique capability to measure neutrino oscillation as a function of energy in a broadband beam, to resolve degeneracy among oscillation parameters, and to control systematic uncertainty using the exquisite imaging capability of massive LArTPC far detector modules and an argon-based near detector. DUNE's neutrino oscillation measurements will unambiguously resolve the neutrino mass ordering and provide the sensitivity to discover CP violation in neutrinos for a wide range of possible values of ÎŽCP. DUNE is also uniquely sensitive to electron neutrinos from a galactic supernova burst, and to a broad range of physics beyond the Standard Model (BSM), including nucleon decays. DUNE is anticipated to begin collecting physics data with Phase I, an initial experiment configuration consisting of two far detector modules and a minimal suite of near detector components, with a 1.2 MW proton beam. To realize its extensive, world-leading physics potential requires the full scope of DUNE be completed in Phase II. The three Phase II upgrades are all necessary to achieve DUNE's physics goals: (1) addition of far detector modules three and four for a total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary muon spectrometer with a magnetized, high-pressure gaseous argon TPC and calorimeter
Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector
Measurements of electrons from interactions are crucial for the Deep
Underground Neutrino Experiment (DUNE) neutrino oscillation program, as well as
searches for physics beyond the standard model, supernova neutrino detection,
and solar neutrino measurements. This article describes the selection and
reconstruction of low-energy (Michel) electrons in the ProtoDUNE-SP detector.
ProtoDUNE-SP is one of the prototypes for the DUNE far detector, built and
operated at CERN as a charged particle test beam experiment. A sample of
low-energy electrons produced by the decay of cosmic muons is selected with a
purity of 95%. This sample is used to calibrate the low-energy electron energy
scale with two techniques. An electron energy calibration based on a cosmic ray
muon sample uses calibration constants derived from measured and simulated
cosmic ray muon events. Another calibration technique makes use of the
theoretically well-understood Michel electron energy spectrum to convert
reconstructed charge to electron energy. In addition, the effects of detector
response to low-energy electron energy scale and its resolution including
readout electronics threshold effects are quantified. Finally, the relation
between the theoretical and reconstructed low-energy electron energy spectrum
is derived and the energy resolution is characterized. The low-energy electron
selection presented here accounts for about 75% of the total electron deposited
energy. After the addition of lost energy using a Monte Carlo simulation, the
energy resolution improves from about 40% to 25% at 50~MeV. These results are
used to validate the expected capabilities of the DUNE far detector to
reconstruct low-energy electrons.Comment: 19 pages, 10 figure
Snowmass Neutrino Frontier: DUNE Physics Summary
The Deep Underground Neutrino Experiment (DUNE) is a next-generation
long-baseline neutrino oscillation experiment with a primary physics goal of
observing neutrino and antineutrino oscillation patterns to precisely measure
the parameters governing long-baseline neutrino oscillation in a single
experiment, and to test the three-flavor paradigm. DUNE's design has been
developed by a large, international collaboration of scientists and engineers
to have unique capability to measure neutrino oscillation as a function of
energy in a broadband beam, to resolve degeneracy among oscillation parameters,
and to control systematic uncertainty using the exquisite imaging capability of
massive LArTPC far detector modules and an argon-based near detector. DUNE's
neutrino oscillation measurements will unambiguously resolve the neutrino mass
ordering and provide the sensitivity to discover CP violation in neutrinos for
a wide range of possible values of . DUNE is also uniquely
sensitive to electron neutrinos from a galactic supernova burst, and to a broad
range of physics beyond the Standard Model (BSM), including nucleon decays.
DUNE is anticipated to begin collecting physics data with Phase I, an initial
experiment configuration consisting of two far detector modules and a minimal
suite of near detector components, with a 1.2 MW proton beam. To realize its
extensive, world-leading physics potential requires the full scope of DUNE be
completed in Phase II. The three Phase II upgrades are all necessary to achieve
DUNE's physics goals: (1) addition of far detector modules three and four for a
total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power
from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary
muon spectrometer with a magnetized, high-pressure gaseous argon TPC and
calorimeter.Comment: Contribution to Snowmass 202
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