2,391 research outputs found
The proximal point method for locally lipschitz functions in multiobjective optimization with application to the compromise problem
This paper studies the constrained multiobjective optimization problem of finding Pareto critical points of vector-valued functions. The proximal point method considered by Bonnel, Iusem, and Svaiter [SIAM J. Optim., 15 (2005), pp. 953–970] is extended to locally Lipschitz functions in the finite dimensional multiobjective setting. To this end, a new (scalarization-free) approach for convergence analysis of the method is proposed where the first-order optimality condition of the scalarized problem is replaced by a necessary condition for weak Pareto points of a multiobjective problem. As a consequence, this has allowed us to consider the method without any assumption of convexity over the constraint sets that determine the vectorial improvement steps. This is very important for applications; for example, to extend to a dynamic setting the famous compromise problem in management sciences and game theory.Fundação de Amparo à Pesquisa do Estado de GoiásConselho Nacional de Desenvolvimento Científico e TecnológicoCoordenação de Aperfeiçoamento de Pessoal de Nivel SuperiorMinisterio de Economía y CompetitividadAgence nationale de la recherch
Relação entre nível de atividade f/ísica em lazer, antropometria, composição corporal e aptidão física de mulheres submetidas à cirurgia bariátrica e um grupo equivalente não operado
Background: Bariatric surgery is an alternative to the obesity treatment. Aim: To compare anthropometric variables such as body composition and physical fitness of those who performed Roux-en-Y gastric bypass. Methods: Were evaluated 108 women. They were subdivided in three groups: those who performed the bariatric surgery by private health insurance (SAS, n=36)by the public health care (SUS, n=36), and an equivalent group which did not perform the surgery (NO, n=36). Were performed physical fitness, anthropometric and body composition tests. Was evaluated the level of physical activity during the leisure period. Results: Statistically significant differences were observed between the groups sedentary operated (n=28) and sedentary non-operated (n=13) on anthropometry and fat percentage, being the highest indexes in the group operated. Conclusion: The level of physical activity showed a positive influence related to anthropometric variables, body composition of the individuals who performed the bariatric surgery when compared to the ones non-operated.Racional: Observa-se o aumento da realização da cirurgia bariátrica como alternativa de tratamento para obesidade. Objetivo: Comparar a antropometria, composição corporal e aptidão física de pacientes submetidos ao bypass gástrico em Y-de-Roux. Métodos: Foram avaliadas 108 mulheres subdivididas em: operadas por convênios de saúde particulares (SAS, n=36), Sistema Único de Saúde (SUS, n=36) e um grupo equivalente não operado (NO, n=36). Foram realizados testes de aptidão física, antropometria e composição corporal, e avaliado nível de atividade física no lazer. Resultados: Não houve diferença estatisticamente significativa nas variáveis estudadas entre os grupos SAS, SUS e NO. Observaram-se diferenças estatisticamente significativas entre os grupos operados sedentários (n=28) e não operados sedentários (n=13) na antropometria e percentual de gordura, sendo ao grupo operado os índices mais altos. Conclusões: O nível de atividade física apresentou influência positiva sobre as variáveis antropométricas, de composição corporal de pacientes submetidos à cirurgia bariátrica quando comparados aos não operados.CNPqUniv Estadual Maringa, Phys Educ Dept, Maringa, Parana, BrazilUniv Estadual Maringa, Postgrad Program UEM UEL, Maringa, Parana, BrazilFed Tocantins Inst, Araguatins, TO, BrazilEduc Bur, Malatya City Hall, Marialva, PR, BrazilUniv Fed Sao Paulo, Interdisciplinary Hlth Sci Postgrad Program, Santos, SP, BrazilUniv Estadual Maringa, Multidisciplinary Ctr Obes Studies, Maringa, Parana, BrazilUniv Fed Sao Paulo, Interdisciplinary Hlth Sci Postgrad Program, Santos, SP, BrazilWeb of Scienc
Brain zinc chelation by diethyldithiocarbamate increased the behavioral and mitochondrial damages in zebrafish subjected to hypoxia
The increase in brain levels of chelatable zinc (Zn) in dysfunctions involving oxygen deprivation has stimulated the treatment with Zn chelators, such as diethyldithiocarbamate (DEDTC). However, DEDTC is a redox-active compound and it should be better evaluated during hypoxia. We use the hypoxia model in zebrafish to evaluate DEDTC effects. The exploratory behavior, chelatable Zn content, activities of mitochondrial dehydrogenases, reactive species levels (nitric oxide, superoxide anion, hydroxyl radical scavenger capacity) and cellular antioxidants (sulfhydryl, superoxide dismutase) of zebrafish brain were assessed after recovery, with or without 0.2mM DEDTC. The increased brain levels of chelatable Zn induced by hypoxia were mitigated by DEDTC. However, the novel tank task indicated that DEDTC did further enhance the exploratory deficit caused by hypoxia. Furthermore, these behavioral impairments caused by DEDTC were more associated with a negative action on mitochondrial activity and brain oxidative balance. Thus, due to apparent pro-oxidant action of DEDTC, our data do not support its use for neuroprotection in neuropathologies involving oxygen deprivation
Early Holocene ritual complexity in South America: the archaeological record of Lapa do Santo (east-central Brazil)
Early Archaic human skeletal remains found in a burial context in Lapa do Santo in eastcentral Brazil provide a rare glimpse into the lives of hunter-gatherer communities in South America, including their rituals for dealing with the dead. These included the reduction of the body by means of mutilation, defleshing, tooth removal, exposure to fire and possibly cannibalism, followed by the secondary burial of the remains according to strict rules. In a later period, pits were filled with disarticulated bones of a single individual without signs of body manipulation, demonstrating that the region was inhabited by dynamic groups in constant transformation over a period of centuries
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory
In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data
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