5,644 research outputs found
ANALYSING THE LOW ADOPTION OF WATER CONSERVATION TECHNOLOGIES BY SMALLHOLDER FARMERS IN SOUTHERN AFRICA
Natural resource degradation and water scarcity are a global concern, which typically threatens the sustainability of smallholder farmers' livelihoods in semi-arid developing areas. As part of research efforts, a number of water-conservation technologies (WCT) have been developed, yet with low adoption rates in smallholder farming environments. This paper discusses the concepts of adoption and innovation, comparing the perspectives of research operators to the ones of smallholder farmers. Discrepancies are highlighted and ultimately explain low uptake of technologies by farmer. Then it addresses socio-economic factors affecting such adoption. It is argued that WCT show specific traits: (1) diversity and applicability to different time and spatial scales; (2) hence, the dependency upon a context. These traits influence dissemination and adoption of WCT, and should not be ignored, from the early stage of technology development. It is shown that adoption does not only depend on individual farmers willingness, but also upon the role of property rights on resources, and collective action at community level. Other specific issues and factors like the demand for WCT, the role of public sector and research, and related biases are also discusses. It finally draws some recommendations towards rural livelihoods that are more sustainable. Farmers' participation in technology development, taking account of local indigenous knowledge and sound institutional arrangements are among other the pathways that are suggested towards a better integration of technology development and innovation processes.adoption, innovation, water conservation, technologies, collective action, property rights, sustainability, livelihoods, Resource /Energy Economics and Policy,
Free-floating molecular clumps and gas mixing: hydrodynamic aftermaths of the intraclusterinterstellar medium interaction
The interaction of gas-rich galaxies with the intra-cluster medium (ICM) of
galaxy clusters has a remarkable impact on their evolution, mainly due to the
gas loss associated with this process. In this work, we use an idealised,
high-resolution simulation of a Virgo-like cluster, run with RAMSES and with
dynamics reproducing that of a zoom cosmological simulation, to investigate the
interaction of infalling galaxies with the ICM. We find that the tails of ram
pressure stripped galaxies give rise to a population of up to more than a
hundred clumps of molecular gas lurking in the cluster. The number count of
those clumps varies a lot over time -- they are preferably generated when a
large galaxy crosses the cluster (M M), and their
lifetime ( Myr) is small compared to the age of the cluster. We
compute the intracluster luminosity associated with the star formation which
takes place within those clumps, finding that the stars formed in all of the
galaxy tails combined amount to an irrelevant contribution to the intracluster
light. Surprisingly, we also find in our simulation that the ICM gas
significantly changes the composition of the gaseous disks of the galaxies:
after crossing the cluster once, typically 20% of the cold gas still in those
disks comes from the ICM.Comment: 9 pages, 6 figures. Accepted for publication in MNRA
I Still Believe In You
https://digitalcommons.library.umaine.edu/mmb-vp/6022/thumbnail.jp
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&
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
Oh, Baby (Don\u27t Say No—Say Maybe)
Sheet music contains misogynistic language and/or imagry promoting rape culture. Contains advertisements and/or short musical examples of pieces being sold by publisher.https://digitalcommons.library.umaine.edu/mmb-vp/6873/thumbnail.jp
壁型ディスプレイとの対話手法に関する研究
電気通信大学200
New Orleans, Nodal Point of the French Atlantic
This article argues for the importance of New Orleans within French and Francophone Studies, with a particular emphasis on a French Atlantic perspective. A historical overview discusses the role of New France, slavery, native Americans, Spain, immigration from Saint-Domingue, the Louisiana Purchase and the American Civil War in the formation of the city, and the rich and under-researched field of the city’s nineteenth-century literary output in French is surveyed. Among the unique aspects of this history are the coherent African cultures exported to Louisiana due to the trafficking of slaves of mostly Bambara ethnicity, their crucial role in the material survival of the colony, and the large presence – from intermarriage, manumission under Spanish rule, and an influx following the Haitian revolution - of free people of colour who contributed to the formation of a Caribbean-type racial hierarchy that did not exist elsewhere in the United States. The article ends with an overview of French representations of the city, in particular A Cotton Office in New Orleans by Edgar Degas, and the city’s place in world tourism, generating questions about the mobile and hybrid meanings attaching to ‘Frenchness’ in this context
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