96 research outputs found
Negotiating Socially Optimal Allocations of Resources
A multiagent system may be thought of as an artificial society of autonomous
software agents and we can apply concepts borrowed from welfare economics and
social choice theory to assess the social welfare of such an agent society. In
this paper, we study an abstract negotiation framework where agents can agree
on multilateral deals to exchange bundles of indivisible resources. We then
analyse how these deals affect social welfare for different instances of the
basic framework and different interpretations of the concept of social welfare
itself. In particular, we show how certain classes of deals are both sufficient
and necessary to guarantee that a socially optimal allocation of resources will
be reached eventually
Negotiating socially optimal allocations of resources
Published versio
Amorphous GaOx based charge trap memory device for neuromorphic applications
In this work, we demonstrate a 3-terminal field-effect based charge trap memory device with an amorphous-GaOx (a-GaOx) layer fabricated at a low deposition temperature of 250°C. Utilizing the long life-time traps in the a-GaOx/Al2O3 stack, we study the charge trap memory effect in the field effect devices. We observe more than one order of magnitude in channel current difference for two memory states with a retention of more than 102 s and endurance of 100 cycles. Our work paves a way for embedded a-GaOx memories for neuromorphic applications
Texture in ITO films deposited at oblique incidence by ion beam sputtering
Texture of crystalline In2O3:Sn (ITO) thin films prepared by combining ion beam sputtering (IBS) at room temperature and oblique angle deposition (OAD) has been studied depending on the vapor incidence on Si substrates (alpha, ranging from 50 degrees to 85 degrees) and the ions used to sputter the target (argon or xenon accelerated at 1.2 keV). Films obtained using Xe ions show an unusual evolution depending on the deposition angle alpha, with the development of a dual biaxial (1 1 1) off-axis texture for alpha 70 degrees that leads to a biaxial (0 0 1) texture at highest deposition angles. These behaviors are well described by mechanisms involving a maximization of the direct capture of the adatoms on {1 1 1} planes, which can however be hindered when mobilities are exalted such as in the case of Ar deposition. The tuning of adatoms mobilities through the IBS process mixed with the control of the deposition angle offered by the OAD geometry appears as an efficient route to achieve an upgraded texture engineering in nanostructured ITO thin films
Application of advanced (S)TEM methods for the study of nanostructured porous functional surfaces: A few working examples
Nanostructured films offer the ability of modifying surface properties, even more, when they can generate layers with controlled porosity. The lower implicit integrity of these (multi)layers when compared to their compact counterparts, hinders the attainment of electron-transparent sections of submicron thicknesses (lamellae), which becomes one of the main reason for the scarcity of studies thorough (scanning-)transmission electron microscopy ((S)TEM). Aware of this opportunity, this report provides an overview of the possibilities offered by the application of a variety of (S)TEM techniques for the study of nanostructured and porous photonic surfaces. A few working examples are presented to illustrate the type of information that can be obtained in the case of mesoporous films prepared either by at oblique angles physical processes as well as nitride nanowire arrays prepared by epitaxy methods. It will be demonstrated that this approach enables the realization of several pioneering works, which are essential to complete the characterization of such porosity-controlled coatings. Topics as diverse as the preparation of electron-transparent specimens and the advanced characterization of their structures, morphologies, interfaces and compositions are addressed thanks to the implementation of new breakthroughs in (S)TEM, which allow to obtain high-resolution imaging, spectroscopies, or tomography, at both microscopic and nanoscopic levels. Finally, establishing (S)TEM as a reference tool for the advanced structural, chemical and morphological characterization of porous nanostructured skins, will open new horizons, providing better and new insights and thus allowing the optimization of the fabrication and design of such architectures
Molecular DNA identity of the mouflon of Cyprus (Ovis orientalis ophion, Bovidae): Near Eastern origin and divergence from Western Mediterranean conspecific populations
The mouflon population of Cyprus (Ovis orientalis ophion) comprises historically preserved feral descendants of sheep
domesticated during the Neolithic. We determined genetic identity of this taxon in order to elucidate its systematic
placement and enforce its protection. We used 12 loci of microsatellite DNA to infer genetic relationships between the
Cypriot mouflon and either long-time isolated (Corsica, Sardinia) or recently introduced (central Italy) European mouflons
(O. o. musimon). We also sequenced the mitochondrial DNA (mtDNA) Cytochrome-b gene to infer the origin of the
Cypriot mouflon including many National Centre for Biotechnology Information (NCBI) entries of European and Near
Eastern conspecifics. Microsatellites disclosed net divergence between Western Mediterranean and Cypriot mouflon. The
latter was included in the highly heterogeneous Near Eastern O. orientalis mtDNA group, Iran representing the most
credited region as the source for its ancient introduction to Cyprus. Both international and national legislation protect the
mouflon of Cyprus as a wild taxon (O. o. ophion). However, the IUCN Red List of Threatened Species and NCBI include
the Cypriot mouflon as subspecies of its respective domestic species, the sheep (O. aries). Unfortunately, people charged
with crime against protected mouflon may benefit from such taxonomic inconsistency between legislation and databases, as
the latter can frustrate molecular DNA forensic outcomes. Until a definitive light can be shed on Near Eastern O. orientalis
systematics, we suggest that the Cypriot mouflon should be unvaryingly referred to as O. o. ophion in order not to impair
conservation in the country where it resides
Effect of Anthropogenic Landscape Features on Population Genetic Differentiation of Przewalski's Gazelle: Main Role of Human Settlement
Anthropogenic landscapes influence evolutionary processes such as population genetic differentiation, however, not every type of landscape features exert the same effect on a species, hence it is necessary to estimate their relative effect for species management and conservation. Przewalski's gazelle (Procapra przewalskii), which inhabits a human-altered area on Qinghai-Tibet Plateau, is one of the most endangered antelope species in the world. Here, we report a landscape genetic study on Przewalski's gazelle. We used skin and fecal samples of 169 wild gazelles collected from nine populations and thirteen microsatellite markers to assess the genetic effect of anthropogenic landscape features on this species. For comparison, the genetic effect of geographical distance and topography were also evaluated. We found significant genetic differentiation, six genetic groups and restricted dispersal pattern in Przewalski's gazelle. Topography, human settlement and road appear to be responsible for observed genetic differentiation as they were significantly correlated with both genetic distance measures [FST/(1−FST) and F′ST/(1−F′ST)] in Mantel tests. IBD (isolation by distance) was also inferred as a significant factor in Mantel tests when genetic distance was measured as FST/(1−FST). However, using partial Mantel tests, AICc calculations, causal modeling and AMOVA analysis, we found that human settlement was the main factor shaping current genetic differentiation among those tested. Altogether, our results reveal the relative influence of geographical distance, topography and three anthropogenic landscape-type on population genetic differentiation of Przewalski's gazelle and provide useful information for conservation measures on this endangered species
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
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