3,893 research outputs found
Pandemic influenza control in Europe and the constraints resulting from incoherent public health laws
© 2010 Martin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: With the emergence of influenza H1N1v the world is facing its first 21st century global pandemic. Severe Acute Respiratory Syndrome (SARS) and avian influenza H5N1 prompted development of pandemic preparedness plans. National systems of public health law are essential for public health stewardship and for the implementation of public health policy[1]. International coherence will contribute to effective regional and global responses. However little research has been undertaken on how law works as a tool for disease control in Europe. With co-funding from the European Union, we investigated the extent to which laws across Europe support or constrain pandemic preparedness planning, and whether national differences are likely to constrain control efforts. Methods: We undertook a survey of national public health laws across 32 European states using a questionnaire designed around a disease scenario based on pandemic influenza. Questionnaire results were reviewed in workshops, analysing how differences between national laws might support or hinder regional responses to pandemic influenza. Respondents examined the impact of national laws on the movements of information, goods, services and people across borders in a time of pandemic, the capacity for surveillance, case detection, case management and community control, the deployment of strategies of prevention, containment, mitigation and recovery and the identification of commonalities and disconnects across states. Results: Results of this study show differences across Europe in the extent to which national pandemic policy and pandemic plans have been integrated with public health laws. We found significant differences in legislation and in the legitimacy of strategic plans. States differ in the range and the nature of intervention measures authorized by law, the extent to which borders could be closed to movement of persons and goods during a pandemic, and access to healthcare of non-resident persons. Some states propose use of emergency powers that might potentially override human rights protections while other states propose to limit interventions to those authorized by public health laws. Conclusion: These differences could create problems for European strategies if an evolving influenza pandemic results in more serious public health challenges or, indeed, if a novel disease other than influenza emerges with pandemic potential. There is insufficient understanding across Europe of the role and importance of law in pandemic planning. States need to build capacity in public health law to support disease prevention and control policies. Our research suggests that states would welcome further guidance from the EU on management of a pandemic, and guidance to assist in greater commonality of legal approaches across states.Peer reviewe
Decoherence-induced geometric phase in a multilevel atomic system
We consider the STIRAP process in a three-level atom. Viewed as a closed
system, no geometric phase is acquired. But in the presence of spontaneous
emission and/or collisional relaxation we show numerically that a
non-vanishing, purely real, geometric phase is acquired during STIRAP, whose
magnitude grows with the decay rates. Rather than viewing this
decoherence-induced geometric phase as a nuisance, it can be considered an
example of "beneficial decoherence": the environment provides a mechanism for
the generation of geometric phases which would otherwise require an extra
experimental control knob.Comment: 9 pages, 12 figure
Existence criteria for stabilization from the scaling behaviour of ionization probabilities
We provide a systematic derivation of the scaling behaviour of various
quantities and establish in particular the scale invariance of the ionization
probability. We discuss the gauge invariance of the scaling properties and the
manner in which they can be exploited as consistency check in explicit
analytical expressions, in perturbation theory, in the Kramers-Henneberger and
Floquet approximation, in upper and lower bound estimates and fully numerical
solutions of the time dependent Schroedinger equation. The scaling invariance
leads to a differential equation which has to be satisfied by the ionization
probability and which yields an alternative criterium for the existence of
atomic bound state stabilization.Comment: 12 pages of Latex, one figur
Efeitos da substituíção da gordura do leite por gordura de soja no crescimento de bezerros.
A gordura hidrogenada de soja possibilitou um desenvolvimento corporal dos bezerros semelhantes ao conseguido atraves da gordura do leite
Bulked segregant analysis of the pirarucu (Arapaima gigas) genome for identification of sex-specific molecular markers.
Arapaima gigas (Osteoglossidae) is one of the largest fish species in the Amazon Basin, attaining lengths of over 2.5 m and weights of over 100 kg. Its flesh is prized, and it has great potential for production in aquaculture systems. However, live pirarucu cannot be reliably sexed visually, even after sexual development, since this species does not have clear external sexual dimorphism. Simple and inexpensive methods for sexing immature pirarucu based on DNA markers would facilitate production of this species in commercial operations. We analyzed A. gigas male and female DNA pools with 566 RAPD primers, generating 2609 fragments, with an estimated 1341 segregating polymorphic markers, and an estimated average spacing of 714 kb, which corresponds to less than 0.1% of the species' genome. Two putative sex-specific fragments were initially identified in bulked samples; but they were not confirmed in a study of individual male and female samples. We suggest that A. gigas has developed a non-chromosomal system of sex determination or, alternatively, that the species has undergone a recent loss of the chromosome carrying the sex-determining locus
ON THE LOCALIZED PHYSICAL EXERGY DISAGGREGATION FOR DISSIPATIVE COMPONENT ISOLATION IN THERMOECONOMICS
Thermoeconomics is a discipline that connects Thermodynamics and Economics concepts, usually used for rational cost allocation to the final products of a thermal plant, by means of a model that describes the cost formation process of the overall system. Generally, exergy or monetary costs of the external resources are distributed to the final products. Exergy is the thermodynamic magnitude used in thermoeconomics and the physical exergy disaggregation has been introduced in thermoeconomics as alternatives for the isolation of the dissipative components and residues allocation. For plants with dissipative equipment, such as condenser or valve, the productive diagram, based on total exergy (E Model), need to merge this dissipative equipment with other productive components. In order to isolate the condenser, the productive diagram must use, at least, the H&S Model and to isolate the valve, the UFS Model has to be considered.Both disaggregation models greatly increase the thermoeconomic modeling complexity. Bearing this in mind, this work aims to evaluate the advantages of combining the E Model with these other models in order to adequately isolate the dissipative equipment. The plants studied herein are two different steam turbine cogeneration systems, with dissipative components (condenser or valve). The different monetary and exergy unit costs obtained for the two final products of each plant are compared and analyzed. The results show that localized physical exergy disaggregation for dissipative component isolation in thermoeconomics is feasible, since it reduces the complexity of the productive structure and is also consistent from the point of view of thermodynamics
Resonant enhancements of high-order harmonic generation
Solving the one-dimensional time-dependent Schr\"odinger equation for simple
model potentials, we investigate resonance-enhanced high-order harmonic
generation, with emphasis on the physical mechanism of the enhancement. By
truncating a long-range potential, we investigate the significance of the
long-range tail, the Rydberg series, and the existence of highly excited states
for the enhancements in question. We conclude that the channel closings typical
of a short-range or zero-range potential are capable of generating essentially
the same effects.Comment: 7 pages revtex, 4 figures (ps files
Alterações nas características fisiológicas de cultivares de cana-de-açúcar submetida à aplicação de herbicidas.
RESUMO - Avaliou-se neste trabalho a influência de herbicidas nas características fisiológicas de três cultivares de cana-de-açúcar. O experimento foi conduzido no delineamento em blocos ao acaso, com três repetições, no esquema fatorial 3 x 8. O fator A foi composto por três cultivares de cana-de-açúcar (RB867515, RB855156 e SP80-1816), e o B, pelos herbicidas (tembotrione, MSMA, diuron + hexazinone, sulfentrazone, trifloxysulfuron-sodium, tebuthiuron, clomazone) e uma testemunha sem uso de herbicidas. A taxa transpiratória das plantas do cultivar RB867515 foi afetada negativamente quando foram aplicados os herbicidas sulfentrazone, tebuthiuron e clomazone em comparação à testemunha. Com relação à eficiência do uso da água, não se observaram diferenças entre os cultivares e a aplicação de herbicidas. A condutância estomática dos cultivares RB867515 e SP80-1816 não foi alterada pelos herbicidas aplicados. Apenas o cultivar RB867515 apresentou taxa fotossintética menor quando se aplicou o sulfentrazone. Os herbicidas testados afetam de forma diferenciada as características fisiológicas nos três cultivares avaliados. O cultivar RB867515 foi o que apresentou menor variação na taxa fotossintética na presença dos produtos testados, em relação à testemunha. ABSTRACT - This work aimed to evaluate the influence of herbicides on the physiological characteristics of three sugarcane cultivars. The experiment was conducted in a randomized block design with three replications in a factorial design 3 x 8. Factor A was constituted of three sugarcane cultivars (RB867515, RB855156, and SP80-1816), and factor B of the herbicides tembotrione, MSMA, diuron + hexazinone, sulfentrazone, trifloxysulfuron-sodium, tebuthiuron, clomazone, and a treatment without herbicide (control). The transpiration rate of cultivar RB867515 plants was negatively affected when sulfentrazone, clomazone, and tebuthiuron were applied,compared to the control. Regarding water use efficiency, no differences were observed between the cultivars and the herbicides. Stomatal conductance of cultivars RB867515 and SP80-1816 was not affected by the herbicides. Only cultivar RB867515 presented lower photosynthetic rate when sulfentrazone was applied. The herbicides tested had distinct effects on the physiological characteristics of the three cultivars evaluated. Cultivar RB867515 showed the least variation in photosynthetic rate in the presence of the products tested, as compared to the control
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