52 research outputs found
Hamiltonian analysis of Poincar\'e gauge theory scalar modes
The Hamiltonian constraint formalism is used to obtain the first explicit
complete analysis of non-trivial viable dynamic modes for the Poincar\'e gauge
theory of gravity. Two modes with propagating spin-zero torsion are analyzed.
The explicit form of the Hamiltonian is presented. All constraints are obtained
and classified. The Lagrange multipliers are derived. It is shown that a
massive spin- mode has normal dynamical propagation but the associated
massless is pure gauge. The spin- mode investigated here is also
viable in general. Both modes exhibit a simple type of ``constraint
bifurcation'' for certain special field/parameter values.Comment: 28 pages, LaTex, submitted to International Journal of Modern Physics
A Medical Support in Offshore Racing — Workshop on Medical Support for Offshore Yacht Races, Telemedical Advice Service (TMAS), 1–2 December 2018, London, United Kingdom
The safety and health of sailors offshore is of major concern. World Sailing (WS) and International Maritime Health Association (IMHA) are taking seriously the potential dangers to the safety and health at sea. By the nature of their sport, the sailors racing in offshore racing environment can be exposed to injuries and other health problems that can endanger their lives. Being aware of the potential dangers caused by the distance from onshore health facilities and lack of professional help on board, IMHA and WS decided to support the activities that are leading to the enhancement of safety and health protection on board. With common initiative, joint Workgroup on Medical Support in Offshore Racing has been formed and the series of workshop organised. The WS/IMHA Workgroup on Medical Support for Offshore Yacht Races previously reached consensus on the common competences and learning outcomes for medical training for offshore racing. In addition, the Workgroup has also set standards for required medical kit inventory for yachts par- ticipating in the various categories of offshore yacht races. Documents were both approved by WS Medical Commission and the IMHA Board. Fourth workshop on Medical Support for Offshore Yacht Races was held in London, United Kingdom, 1–2 December 2018 and workgroup reached consensus on the standards for availability of Telemedical Advice Services (TMAS) for the various categories of offshore yacht races held under the authority of WS. This position paper sets out how the TMAS should be integrated with the practical usage of medicines and medical equipment on board offshore racing yachts. In addition, this position paper also sets out how the level of medical training integrates with appropriate use of the TMAS. Overall, the three WS/IMHA position papers on the triad of medical inventories, medical training and TMAS, are aimed at providing the best possible medical care on offshore racing yachts, by fully integrating each part of the triad of medical support.
The impact of changes in psoriasis area and severity index by body regions on quality of life in patients with psoriasis
Psoriasis severity varies by body region, with each affected region having a different impact on patient quality of life (QoL). The aim of this study was to assess the impact of changes in the Psoriasis Area and Severity Index (PASI) scores by body region on QoL in patients with psoriasis after treatment. A total of 100 patients with psoriasis were recruited to the study. All patients completed the generic EuroQol-5D instrument and two specific QoL measures, Dermatology Life Quality Index (DLQI) and Psoriasis Disability Index (PDI) at the beginning of the study, and 50 patients successfully completed the same questionnaires four weeks after the end of the treatment. Clinical severity was assessed using PASI total score and PASI body region (head, trunk, arms, and legs) scores. QoL improved after treatment, and PASI improvements on visible body regions (head, legs, and arms) showed significant correlation with the most sub-areas of the Visual Analog Scale (EQ VAS), DLQI, and PDI. Multiple linear regression analysis revealed that PASI improvement (particularly on the head), sex, age, and disease duration were predictors of QoL score changes for most domains of the three instruments. Improvement of psoriasis in visible body regions has an appreciable influence on QoL improvement, and may positively affect treatment success in patients with psoriasis. riadPro-Regular;color:black;mso-ansi-language:EN-US; mso-fareast-language:HR;mso-bidi-language:TA\u27>The proportion of ADHD in patients with AD was 7.1% as compared to 4.1% in controls. ADHD was more frequent in boys with AD (9.6% vs. 5.2%, odds ratio (OR) 1.9, 95% confidence interval (CI) 1.1-3.2) but not in girls with AD (4.6% vs. 2.9% OR 1.5). In multivariate analyses, AD was associated with ADHD (OR 2.1, 95% CI 1.3-3.4). The current study demonstrated an association between AD and ADHD. This report and earlier observations emphasize the need for detection and treatment of ADHD in atopic patients. </p
The status and role of genetic diversity of trees for the conservation and management of riparian ecosystems: a European experts' perspective
Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts. We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems. We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species. The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required. Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framewor
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Beyond punitiveness? Governance of crime and authoritarian heritage in Serbia
This article sets out to examine the degree to which democratic transition in Serbia after 2000 has brought about a democratic mode of crime governance in the country. It is shown that while penal norms and policies have undergone a significant degree of democratization in that their outlook has tended not to be punitive, the judiciary (and, to some degree, other actors in the penal field) has been increasingly inclined towards punitive practices. Taking an institutional approach to explain this discrepancy, the article argues that pockets of authoritarianism in the executive have survived the transition to democracy and have continued to exert pressure on the judiciary in ways that have influenced judicial decision-making towards greater punitiveness
Drought Impact Is Alleviated in Sugar Beets (Beta vulgaris L.) by Foliar Application of Fullerenol Nanoparticles
Over the past few years, significant efforts have been made to decrease the effects of drought stress on plant productivity and quality. We propose that fullerenol nanoparticles (FNPs, molecular formula C-60(OH)(24)) may help alleviate drought stress by serving as an additional intercellular water supply. Specifically, FNPs are able to penetrate plant leaf and root tissues, where they bind water in various cell compartments. This hydroscopic activity suggests that FNPs could be beneficial in plants. The aim of the present study was to analyse the influence of FNPs on sugar beet plants exposed to drought stress. Our results indicate that intracellular water metabolism can be modified by foliar application of FNPs in drought exposed plants. Drought stress induced a significant increase in the compatible osmolyte proline in both the leaves and roots of control plants, but not in FNP treated plants. These results indicate that FNPs could act as intracellular binders of water, creating an additional water reserve, and enabling adaptation to drought stress. Moreover, analysis of plant antioxidant enzyme activities (CAT, APx and GPx), MDA and GSH content indicate that fullerenol foliar application could have some beneficial effect on alleviating oxidative effects of drought stress, depending on the concentration of nanoparticles applied. Although further studies are necessary to elucidate the biochemical impact of FNPs on plants; the present results could directly impact agricultural practice, where available water supplies are often a limiting factor in plant bioproductivity
Quantum Algorithms for the k-xor Problem
International audienceThe k-xor (or generalized birthday) problem is a widely studied question with many applications in cryptography. It aims at finding k elements of n bits, drawn at random, such that the xor of all of them is 0. The algorithms proposed by Wagner more than fifteen years ago remain the best known classical algorithms for solving them, when disregarding logarithmic factors. In this paper we study these problems in the quantum setting, when considering that the elements are created by querying a random function (or k random functions) H : {0, 1} n → {0, 1} n. We consider two scenarios: in one we are able to use a limited amount of quantum memory (i.e. a number O(n) of qubits, the same as the one needed by Grover's search algorithm), and in the other we consider that the algorithm can use an exponential amount of qubits. Our newly proposed algorithms are of general interest. In both settings, they provide the best known quantum time complexities. In particular, we are able to considerately improve the 3-xor algorithm: with limited qubits, we reach a complexity considerably better than what is currently possible for quantum collision search. Furthermore, when having access to exponential amounts of quantum memory, we can take this complexity below O(2 n/3), the well-known lower bound of quantum collision search, clearly improving the best known quantum time complexity also in this setting. We illustrate the importance of these results with some cryptographic applications
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