938 research outputs found
Production Under Uncertainty: A Simulation Study
In this article we model production technology in a state-contingent framework. Our model analyzes production under uncertainty without regard to the nature of producer risk preferences. In our model producers? risk preferences are captured by the risk-neutral probabilities they assign to the different states of nature. Using a state-general state-contingent specification of technology we show that rational producers who encounter the same stochastic technology can make significantly different production choices. Further, we develop an econometric methodology to estimate the risk-neutral probabilities and the parameters of stochastic technology when there are two states of nature and only one of which is observed. Finally, we simulate data based on our state-general state-contingent specification of technology. Biased estimates of the technology parameters are obtained when we apply conventional ordinary least squares (OLS) estimator on the simulated data.
GLOBAL TRENDS IN EDDY KINETIC ENERGY FROM SATELLITE ALTIMETRY
The temporal changes in the oceanic eddy kinetic energy (EKE) including trends and
variability are presented and the dynamical mechanisms are investigated. The domain
is near-global with a focus on the North Atlantic, North Pacific and Southern Oceans.
Altimeter-derived geostrophic surface velocities are used to compute an 18 year time
series of EKE on a 1/3ïżœ grid. Linear trends are best-fit to the 18-year time series and
their statistical significance assessed using bootstrap techniques. Near-global mean
EKE trends are non-statistically significant. However, on a regional scale, statistically
significant trends are found in all of the major ocean basins. Widespread negative
trends occur primarily in the northern and southern subtropical Pacific as well as the
central North Atlantic, while positive trends occur primarily in the North Atlantic subtropical
gyre, much of the northeast North Atlantic, the southeast Indian Ocean and in
several regions in the Southern Ocean. Buoyancy forcing and non-local wind forcing
related to the PDO are significant in the North Pacific. In the North Atlantic, changes
in wind stress curl as well as changes in local wind speed are implicated, where a
di-polar pattern of correlations with the NAO is observed. In the Southern Ocean,
changes in local and/or remote winds appear as the dominant mechanism south of
30ïżœS. On a global scale, EKE trends are slightly positive (0.15% of the mean per
decade) but non-statistically significant. EKE has decreased in the northern hemisphere
and increased in the southern hemisphere despite an increase in hemispheric
mean wind speed in both northern and southern hemispheres. Changing wind speeds
are influential across all the ocean basins but other mechanisms are significant including
shifting wind stress curl fields, buoyancy forcing, indirect (non-local) winds and
intrinsic variability. Statistically significant correlations between annual mean EKE
and major modes of climate variability are evident in all the ocean basins
Trade Agreements in the Last 20 Years: Retrospect and Prospect for Agriculture / Les accords commerciaux au cours des 20 derniĂšres annĂ©es : rĂ©trospective et perspectives pour lâagriculture / Handelsabkommen in den letzten 20 Jahren: RĂŒckblick und Ausblick fĂŒr die Landwirtschaft
We provide an overview of major developments in multi-and plurilateral trade agreements over the last twenty years with a focus on the implications for agricultural and food markets. We take stock of what has been accomplished in market integration, remaining obstacles to trade, events that have changed the trade landscape, and emerging issues. Agricultural tariffs have fallen through commitments made in the Uruguay Round Agreement on Agriculture and through the proliferation of regional trade agreements (RTAs). Nevertheless, agricultural trade remains distorted with some extremely high tariffs. RTAs have achieved progress on nontariff measures and other beyond-the- border frictions. World Trade Organization (WTO) negotiations on agricultural trade distortions have stalled because of their complexity and divergent political interests among WTO members. In addition, the dispute settlement mechanism no longer functions. The WTO will have to adjust to a world of RTAs and use its tools and procedures to support the multilateral trading system by promoting increased transparency of RTAs and their conformity with existing WTO agreements. The WTO can also use existing tools to head off disputes using specific trade concern mechanisms, such as those implemented through the sanitary and phytosanitary (SPS) and Technical Barriers to Trade (TBT) committees.
dâensemble des principales Ă©volutions dans les accords commerciaux multilatĂ©raux et plurilatĂ©raux au cours des vingt derniĂšres annĂ©es, en mettant lâaccent sur les implications pour les marchĂ©s agricoles et alimentaires. Nous faisons le point sur ce qui a Ă©tĂ© accompli en matiĂšre dâintĂ©gration des marchĂ©s, les obstacles au commerce restant en place, les Ă©vĂ©nements qui ont modifiĂ© le paysage commercial et les problĂšmes Ă©mergents. Les tarifs agricoles ont baissĂ© du fait des engagements pris dans le cadre de lâAccord du Cycle dâUruguay sur lâagriculture et de la prolifĂ©ration des accords commerciaux rĂ©gionaux (ACR). NĂ©anmoins, le commerce agricole reste faussĂ©, certains droits de douane demeurant extrĂȘmement Ă©levĂ©s. Les ACR ont permis de rĂ©aliser des progrĂšs sur les mesures non tarifaires et dâautres frictions au-delĂ des frontiĂšres. Les nĂ©gociations Ă lâOrganisation mondiale du commerce (OMC) sur les distorsions des Ă©changes agricoles sont au point mort en raison de leur complexitĂ© et des intĂ©rĂȘts politiques divergents parmi les membres de lâOMC. De plus, le mĂ©canisme de rĂšglement des diffĂ©rends ne fonctionne plus. LâOMC devra sâadapter Ă un monde dâACR et utiliser ses outils et procĂ©dures pour soutenir le systĂšme commercial multilatĂ©ral en promouvant une transparence accrue des ACR et leur conformitĂ© avec les accords existants de lâOMC. LâOMC peut Ă©galement utiliser les outils existants pour Ă©viter les diffĂ©rends en utilisant les mĂ©canismes portant sur des questions commerciales spĂ©cifiques, tels que ceux mis en oeuvre par le biais des comitĂ©s pour les questions sanitaire et phytosanitaire (SPS) et les obstacles techniques au commerce (OTC).
Wir geben einen Ăberblick ĂŒber die wichtigsten Entwicklungen bei multi-und plurilateralen Handelsabkommen in den letzten zwanzig Jahren. Der Fokus liegt dabei auf den Agrar-und LebensmittelmĂ€rkten. Wir machen eine Bestandsaufnahme von dem, was bei der Marktintegration erreicht wurde, von den verbleibenden Handelshemmnissen, von Ereignissen, die die Handelslandschaft verĂ€ndert haben, und von neuen Problemen. Die Agrarzölle sind durch die BeschlĂŒsse der Uruguay-Runde und durch die zunehmende Anzahl an regionalen Handelsabkommen (RTAs) gesunken. Dennoch bleibt der Agrarhandel mit einigen extrem hohen Zöllen verzerrt. Im Rahmen der regionalen Handelsabkommen wurden Fortschritte bei nichttarifĂ€ren MaĂnahmen und anderen grenzĂŒberschreitenden Spannungen erzielt. Die Verhandlungen der Welthandelsorganisation (WTO) ĂŒber Handelsverzerrungen im Agrarbereich sind aufgrund ihrer KomplexitĂ€t und der unterschiedlichen politischen Interessen ihrer Mitglieder ins Stocken geraten. DarĂŒber hinaus funktioniert der WTO-Streitbeilegungsmechanismus nicht mehr. Die WTO muss sich auf eine Welt mit regionalen Handelsabkommen einstellen. Und sie muss ihre Instrumente und Verfahren einsetzen, um das multilaterale Handelssystem zu unterstĂŒtzen, indem sie eine gröĂere Transparenz der regionalen Handelsabkommen und deren Ăbereinstimmung mit den bestehenden WTO-Ăbereinkommen fördert. Die WTO kann hierbei auch auf bestehende Instrumente zurĂŒckgreifen, um Streitigkeiten mit Hilfe spezieller Mechanismen fĂŒr Handelsfragen abzuwenden. Als Beispiele können die AusschĂŒsse fĂŒr gesundheitliche und pflanzenschutzrechtliche MaĂnahmen (SPS) und technische Handelshemmnisse (TBT) genannt werden
Hip Arthroscopy Made Simple, Easy, and Elegant. A Novel Variant of the Outside-In Technique
Hip Arthroscopy (HA) is considered to be a demanding surgery with a steep and slow learning curve. Adequate HA instrumentation is required to perform a reproducible surgery. The technique most commonly used to access the hip is through the central compartment or from the âInside-Outâ with continuous distraction and specialized access equipment. Newer techniques start from the peripheral compartment called âOutside-Inâ techniques, these techniques have a safer access with a more controlled environment avoiding iatrogenic scuffing of the acetabulum, labrum or femoral head. The purpose of this surgical and novel variant technique from the âOutside-Inâ which we call simple, easy, and elegant is an excellent choice and can be part of the armament for young surgeons who are initiating in hip arthroscopy and preservation, our technique has been very reproducible and reliable with good to excellent results with very few complications
Integration, co-ordination and multidisciplinary care in Australia: Growth via optimal governance arrangements
ustralian governments, communities and health professionals are looking at new ways to deliver high quality health care services as traditional, fragmented models struggle to deliver appropriate, accessible care in the current environment.
The Council of Australian Governments and Commonwealth mental health initiatives will require interjurisdictional relationships that have not existed before. To sustain these reforms effective and integrated governance will be key.The research reported in this paper is a project of the Australian Primary Health Care Research Institute which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research Evaluation and Development Strategy
Integration, co-ordination and multidisciplinary care in Australia: growth via optimal governance arrangements
The research reported in this paper is a project of the Australian Primary Health Care Research Institute, which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research, Evaluation and Development Strategy
Design, fabrication and test of integrated micro-scale vibration based electromagnetic generator
This paper discusses the design, fabrication and testing of electromagnetic microgenerators. Three different designs of power generators are partially microfabricated and assembled. Prototype A having a wire-wound copper coil, Prototype B, an electrodeposited copper coil both on a Deep Reactive Ion etched (DRIE) silicon, beam and paddle. Prototype C uses moving NdFeB magnets in between two microfabricated coils. The integrated coil, paddle and beam were fabricated using standard micro-Electro-Mechanical Systems (MEMS) processing techniques. For Prototype A, the maximum measured power output was 148 nW at 8.08 kHz resonant frequency and 3.9 m/s2 acceleration. For prototype B, the microgenerator gave a maximum load power of 23 nW for an acceleration of 9.8 m/s2, at a resonant frequency of 9.83 kHz. This is a substantial improvement in power generated over other microfabricated silicon based generators reported in literature. This generator has a volume of 0.1 cm3 which is lowest of all the silicon based microfabricated electromagnetic power generators reported. To verify the potential of integrated coils in electromagnetic generators, Prototype C was assembled. This generated a maximum load power of 5
Bioprosthetic Aortic Valve Fracture During Valve-in-valve Transcatheter Aortic Valve Implantation
The limited durability of surgical bioprostheses, combined with an ageing population, has led to an increasing demand for replacing degenerated bioprosthetic surgical heart valves, which is projected to increase. Valve-in-valve transcatheter aortic valve implantation involves implanting a transcatheter heart valve within a degenerated bioprosthetic surgical heart valve. A significant minority of patients, however, are left with a suboptimal haemodynamic result with high residual gradients. This is more common with smaller surgical bioprostheses, and may be associated with a worse prognosis. The novel concept of fracturing the previously implanted bioprosthetic surgical heart valve during valve- in-valve transcatheter aortic valve implantation to create a more favourable haemodynamic profile has shown great promise, particularly in smaller valves. Herein, we describe the benefits, limitations and potential complications of this novel approach
Institutionalizing resilience in U.S. universities: Prospects, opportunities, and models
The United States is taking a largely region-specific approach to addressing challenges posed by climate change, in contrast with national and international approaches in most of the rest of the world. In locations such as Hampton Roads,New Orleans, and coastal Connecticut, the impacts of climate change tend to be addressed as they become locally evident rather than as part of a larger anticipatory national plan. Given that regional focus, universities can play a unique role in how the United States responds to the challenges of a changing climate
Vibration based electromagnetic micropower generator on silicon
This paper discusses the theory, design and simulation of electromagnetic micropower generators with electroplated micromagnets. The power generators are fabricated using standard microelectromechanical system processing techniques. Electromagnetic two-dimensional finite element anlysis simulations are used to determine voltage and power that can be generated from different designs. This paper reports a maximum voltage and power of 55 mV and 70 mu W for the first design, incorporating microfabricated two-layer Cu coils on a Si paddle vibrating between two sets of oppositely polarized electroplated Co50Pt50 face centered tetragonal phase hard magnets. A peak voltage and power of 950 mV and 85 mu W are obtained for the second design, which includes electroplated Ni45Fe55 as a soft magnetic layer underneath the hard magnets. The volume of the device is about 30 mm(3)
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