989 resultados para Restrictions de signe
Resumo:
In 2005 the Swiss government implemented new work-hour limitations for all residency programs in Switzerland, including a 50-hour weekly limit. The reduction in the working hours of doctors in training implicate an increase in their rest time and suggest an amelioration of doctors' clinical performance and consequently in patients' outcomes and safety - which was not detectable in a preliminary study at a large referral center in Switzerland. It remains elusive why work-hour restrictions did not improve patient safety. We are well advised to thoroughly examine and eliminate the known adverse effects of reduced work-hours to improve our patients' safety.
Resumo:
This paper deals with scheduling batch (i.e., discontinuous), continuous, and semicontinuous production in process industries (e.g., chemical, pharmaceutical, or metal casting industries) where intermediate storage facilities and renewable resources (processing units and manpower) of limited capacity have to be observed. First, different storage configurations typical of process industries are discussed. Second, a basic scheduling problem covering the three above production modes is presented. Third, (exact and truncated) branch-and-bound methods for the basic scheduling problem and the special case of batch scheduling are proposed and subjected to an experimental performance analysis. The solution approach presented is flexible and in principle simple, and it can (approximately) solve relatively large problem instances with sufficient accuracy.
Resumo:
Conventional wisdom on the insufficiency of existing WTO disciplines on export restrictions has triggered momentum on the issue. In this book, Ilaria Espa offers a comprehensive analysis of the scope and coverage of WTO disciplines on export restrictions in light of emerging case law. She investigates whether such rules still provide a credible and effective framework capable of preventing abuses in the use of export restrictive measures on critical minerals and metals during a period of economic crisis and change in international trade patterns. Giving a broad overview of the export restrictions applied to these materials, Espa identifies distinctive features in the proliferation of export barriers and analyses the existing WTO rules to reveal their gaps and inconsistencies. She goes on to present solutions based upon her findings with the aim of bringing more coherence and equity to WTO rules on the export side.
Resumo:
This chapter aims at contributing to the trade and energy debate by focusing on the specific issue of export restrictions. It starts from the premise that a balanced and efficient regulation of export barriers in the energy sector would contribute to tackle emerging energy concerns such as energy security and the elimination of fossil fuel subsidies in light of the challenge of climate change mitigation. It assesses the adequacy of existing WTO rules on export restrictions and accordingly identifies the main gaps and inconsistencies inherent in the current disciplines from an energy-specific perspective. Finally, it discusses the merits of an energy-specific approach to advance existing disciplines in the most deficient area of export duties based on the systematisation of the Russian ‘model’. Such approach could raise the overall level of commitments in the energy sector while still allowing for the systemic applicability of GATT environmental exceptions in a manner consistent with the principle of sustainable development recognised in the Preamble of the WTO Agreement.
Resumo:
A new E15 Think Piece by Ilaria Espa produced under the E15Initiative (E15). Implemented jointly by the International Centre for Trade and Sustainable Development (ICTSD) and the World Economic Forum, the E15 convenes world-class experts and institutions to generate strategic analysis and recommendations for government, business and civil society geared towards strengthening the global trade system. This paper considers concrete policy options to better regulate the use of export restrictions in relation to extractive industries. It briefly describes recent trends in the use of export restrictions on mineral and energy resources. It gives an account of the main shortcomings in the WTO legal treatment of export restrictions. It accordingly discusses possible avenues for reforming existing WTO disciplines in the interest of secure access to supplies, while still taking into account the need to preserve some policy space for host countries to use such measures as legitimate development tools.
Resumo:
Salt accumulation in spinach (Spinacia oleracea L.) leaves first inhibits photosynthesis by decreasing stomatal and mesophyll conductances to CO2 diffusion and then impairs ribulose-1,5-bisphosphate carboxylase/oxygenase (S. Delfine, A. Alvino, M. Zacchini, F. Loreto [1998] Aust J Plant Physiol 25: 395–402). We measured gas exchange and fluorescence in spinach recovering from salt accumulation. When a 21-d salt accumulation was reversed by 2 weeks of salt-free irrigation (rewatering), stomatal and mesophyll conductances and photosynthesis partially recovered. For the first time, to our knowledge, it is shown that a reduction of mesophyll conductance can be reversed and that this may influence photosynthesis. Photosynthesis and conductances did not recover when salt drainage was restricted and Na content in the leaves was greater than 3% of the dry matter. Incomplete recovery of photosynthesis in rewatered and control leaves may be attributed to an age-related reduction of conductances. Biochemical properties were not affected by the 21-d salt accumulation. However, ribulose-1,5-bisphosphate carboxylase/oxygenase activity and content were reduced by a 36- to 50-d salt accumulation. Photochemical efficiency was reduced only in 50-d salt-stressed leaves because of a decrease in the fraction of open photosystem II centers. A reduction in chlorophyll content and an increase in the chlorophyll a/b ratio were observed in 43- and 50-d salt-stressed leaves. Low chlorophyll affects light absorptance but is unlikely to change light partitioning between photosystems.
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The host range of retroviral oncogenes is naturally limited by the host range of the retroviral vector. The question of whether the transforming host range of retroviral oncogenes is also restricted by the host species has not been directly addressed. Here we have tested in avian and murine host species the transforming host range of two retroviral onc genes, myc of avian carcinoma viruses MH2 and MC29 and mht/raf of avian carcinoma virus MH2 and murine sarcoma virus MSV 3611. Virus vector-mediated host restriction was bypassed by recombining viral oncogenes with retroviral vectors that can readily infect the host to be tested. It was found that, despite high expression, transforming function of retroviral myc genes is restricted to avian cells, and that of retroviral mht/raf genes is restricted to murine cells. Since retroviral oncogenes encode the same proteins as certain cellular genes, termed protooncogenes, our data must also be relevant to the oncogene hypothesis of cancer. According to this hypothesis, cancer is caused by mutation of protooncogenes. Because protooncogenes are conserved in evolution and are presumed to have conserved functions, the oncogene hypothesis assumes no host range restriction of transforming function. For example, mutated human proto-myc is postulated to cause Burkitt lymphoma, because avian retroviruses with myc genes cause cancer in birds. But there is no evidence that known mutated protooncogenes can transform human cells. The findings reported here indicate that host range restriction appears to be one of the reasons (in addition to insufficient transcriptional activation) why known, mutated protooncogenes lack transforming function in human cells.
Resumo:
As it is known, there is no rule satisfying additivity in the complete domain of bankruptcy problems. This paper proposes a notion of partial additivity in this context, to be called μ-additivity. We find out that this property, together with two quite compelling axioms, equal treatment of equals and continuity, identify the minimal overlap rule, introduced by O’Neill (Math. Soc. Sci. 2:345–371, 1982).
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At first glance the Aliens Restriction Act of 1914, which was introduced and passed on the first day of World War One, seems a hasty and ill-prepared piece of legislation. Actually, when examined in the light of Arthur Marwick's thesis that war is a forcing house for pre-existent social and governmental ideas, it becomes clear that the act was not after all the product of hastily formed notions. In point of fact it followed the precedent of detailed draft clauses produced in 1911 by a sub-committee of the Committee of Imperial Defence established to consider the treatment of aliens in the event of war. Indeed the draft clauses and the restrictions embodied in the 1914 act were strikingly similar to restrictions on aliens legislated in 1793. Hostility to aliens had been growing from 1905 to 1914 and this hostility blossomed into xeno-phobia on the outbreak of war, a crucial precondition for the specifically anti-enemy fears of the time. In 1919 the Aliens Restriction (Amendment) Bill was introduced into parliament to extend temporarily the provisions of the 1914 act thus permitting the Home Secretary to plan permanent, detailed legislation. Two minority groups of MPs with extreme views on the treatment of aliens were prominent in the debates on this bill. The extreme Liberal group which advocated leniency in the treatment of aliens had little effect on the final form of the bill, but the extreme Conservative group, which demanded severe restrictions on aliens, succeeded in persuading the government to include detailed restrictions. Despite its allegedly temporary nature, the Aliens Restriction (Amendment) Act of 1919 was renewed annually until 1971.