4,954 research outputs found
A Methodology for Classifying Search Operators as Intensification or Diversification Heuristics
Selection hyper-heuristics are generic search tools that dynamically choose, from a given pool, the most promising operator (low-level heuristic) to apply at each iteration of the search process. The performance of these methods depends on the quality of the heuristic pool. Two types of heuristics can be part of the pool: diversification heuristics, which help to escape from local optima, and intensification heuristics, which effectively exploit promising regions in the vicinity of good solutions. An effective search strategy needs a balance between these two strategies. However, it is not straightforward to categorize an operator as intensification or diversification heuristic on complex domains. Therefore, we propose an automated methodology to do this classification. This brings methodological rigor to the configuration of an iterated local search hyper-heuristic featuring diversification and intensification stages. The methodology considers the empirical ranking of the heuristics based on an estimation of their capacity to either diversify or intensify the search. We incorporate the proposed approach into a state-of-the-art hyper-heuristic solving two domains: course timetabling and vehicle routing. Our results indicate improved performance, including new best-known solutions for the course timetabling problem
Burden of smoking in Brazil and potential benefit of increasing taxes on cigarettes for the economy and for reducing morbidity and mortality
The prevalence of smoking in Brazil has decreased considerably in recent decades, but the country still has a high burden of disease associated with this risk factor. The study aimed to estimate the burden of mortality, morbidity, and costs for society associated with smoking in 2015 and the potential impact on health outcomes and the economy based on price increases for cigarettes through taxes. Two models were developed: the first is a mathematical model based on a probabilistic microsimulation of thousands of individuals using hypothetical cohorts that considered the natural history, costs, and quality of life of these individuals. The second is a tax model applied to estimate the economic benefit and health outcomes in different price increase scenarios in 10 years. Smoking was responsible for 156,337 deaths, 4.2 million years of potential life lost, 229,071 acute myocardial infarctions, 59,509 strokes, and 77,500 cancer diagnoses. The total cost was BRL 56.9 billion (USD 14.7 billion), with 70% corresponding to the direct cost associated with healthcare and the rest to indirect cost due to lost productivity from premature death and disability. A 50% increase in cigarette prices would avoid 136,482 deaths, 507,451 cases of cardiovascular diseases, 64,382 cases of cancer, and 100,365 cases of stroke. The estimated economic benefit would be BRL 97.9 billion (USD 25.5 billion). In conclusion, the burden of disease and economic losses associated with smoking is high in Brazil, and tax increases are capable of averting deaths, illness, and costs to society
Baterias para una movilidad sostenible: avances, retos y perspectiva
La aplicación de baterías acopladas a sistemas de conversión de energía renovable en las ciudades ayudará en gran medida a superar algunos de los retos tecnológicos para la electrificación de la red y el transporte, como la difícil accesibilidad a puntos de carga, y de coste, mejorando sus capacidades técnicas y haciendo que el sistema energético a nivel global sea más sostenible. Además, su aplicación tendrá un efecto inmediato en la salud de los ciudadanos debido a la disminución de las emisiones de gases de efecto invernadero a la atmósfera, así como otros contaminantes. A continuación, presentamos una revisión de los esfuerzos recientes para desarrollar nuevas tecnologías avanzados para las futuras baterías sostenibles. También destacaremos las estrategias actuales de reciclado de baterías que se aplican hacia un futuro con cero emisiones de carbono y basado en el concepto de economía circular.
The application of batteries coupled to renewable energy conversion systems in cities will greatly help to overcome some of the technological challenges for grid electrification and transport, such as difficult accessibility to charging points, and cost, by improving their technical capabilities and making the energy system globally more sustainable. Furthermore, its implementation will have an immediate effect on citizens'' health due to the reduction of greenhouse gas emissions into the atmosphere, as well as other pollutants. Below is a review of recent efforts to develop new advanced technologies for future sustainable batteries. We will also highlight current battery recycling strategies that are being implemented towards a zero-carbon future based on the concept of the circular economy
8-hydroxy-2'-deoxyguanosine, a major mutagenic oxidative DNA lesion, and DNA strand breaks in nasal respiratory epithelium of children exposed to urban pollution.
Southwest metropolitan Mexico City children are repeatedly exposed to high levels of a complex mixture of air pollutants, including ozone, particulate matter, aldehydes, metals, and nitrogen oxides. We explored nasal cell 8-hydroxy-2'-deoxyguanosine (8-OHdG), a major mutagenic lesion producing G-->T transversion mutations, using an immunohistochemical method, and DNA single strand breaks (ssb) using the single cell gel electrophoresis assay as biomarkers of oxidant exposure. Nasal biopsies from the posterior inferior turbinate were examined in children in grades one through five, including 12 controls from a low-polluted coastal town and 87 Mexico City children. Each biopsy was divided for the 8-OHdG and DNA ssb assays. There was an age-dependent increase in the percentage of nasal cells with DNA tails > 10 microm in Mexico City children: 19 +/- 9% for control cells, and 43 +/- 4, 50 +/- 16, 56 +/- 17, 60 +/- 17 and 73 +/- 14%, respectively, for first through fifth graders (p < 0.05). Nasal ssb were significantly higher in fifth graders than in first graders (p < 0.05). Higher levels (2.3- to 3-fold) of specific nuclear staining for 8-OHdG were observed in exposed children as compared to controls (p < 0.05). These results suggest that DNA damage is present in nasal epithelial cells in Mexico City children. Persistent oxidative DNA damage may ultimately result in a selective growth of pr eneoplastic nasal initiated cells in this population and the potential for nasal neoplasms may increase with age. The combination of 8-OHdG and DNA ssb should be useful for monitoring oxidative damage in people exposed to polluted atmospheres
Measurement of single charged pion production in the charged-current interactions of neutrinos in a 1.3GeV wide band beam
Single charged pion production in charged-current muon neutrino interactions with carbon is studied using data collected in the K2K long-baseline neutrino experiment. The mean energy of the incident muon neutrinos is 1.3 GeV. The data used in this analysis are mainly from a fully active scintillator detector, SciBar. The cross section for single π+ production in the resonance region (W\u3c2GeV/c2) relative to the charged-current quasielastic cross section is found to be 0.734-0.153+0.140. The energy-dependent cross section ratio is also measured. The results are consistent with a previous experiment and the prediction of our model. © 2008 The American Physical Society
Reuse of oak chips for modification of the volatile fraction of alcoholic beverages
New or used barrels can be applied in ageing of alcoholic beverages. Compounds adsorbed in wood migrate between beverages along with wood extractives. As barrel ageing is costly and time-consuming, processes using wood fragments have been gaining interest. These generate wood residues for which the reuse is still not well established. This work aims at the reuse of oak fragments for the additive ageing of alcoholic beverages. Oak chips, previously immersed in fortified wine, were applied to beer, wine and grape marc spirit. Wood compounds and adsorbed wine volatiles were extracted, with more impact and satisfactory yields on beer composition. Also, wood adsorbed beverages compounds in a subtractive ageing phenomena. Beer formulations using different binomial wood concentration/temperature combinations were generated and presented to trained tasters. Higher temperatures and wood concentrations led to prominence of wood descriptors and lower perception of fruity and floral aromas, reflecting the changes in chemical composition.Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Fermentum – Engenharia das Fermentações Lda. also participated in co-funding and provided beer samples used in this work, which authors would like to acknowledge. Lastly, authors would like to thank Mr. Benoît Verdier and Seguin Moreau for supplying the woods and Mr. Paulo Coutinho and Quinta do Portal for supplying the fortified wineinfo:eu-repo/semantics/publishedVersio
Experimental study of the atmospheric neutrino backgrounds for proton decay to positron and neutral pion searches in water Cherenkov detectors
The atmospheric neutrino background for proton decay to positron and neutral
pion in ring imaging water Cherenkov detectors is studied with an artificial
accelerator neutrino beam for the first time. In total, about 314,000 neutrino
events corresponding to about 10 megaton-years of atmospheric neutrino
interactions were collected by a 1,000 ton water Cherenkov detector (KT). The
KT charged-current single neutral pion production data are well reproduced by
simulation programs of neutrino and secondary hadronic interactions used in the
Super-Kamiokande (SK) proton decay search. The obtained proton to positron and
neutral pion background rate by the KT data for SK from the atmospheric
neutrinos whose energies are below 3 GeV is about two per megaton-year. This
result is also relevant to possible future, megaton-scale water Cherenkov
detectors.Comment: 13 pages, 16 figure
Measurement of single charged pion production in the charged-current interactions of neutrinos in a 1.3 GeV wide band beam
Single charged pion production in charged-current muon neutrino interactions
with carbon is studied using data collected in the K2K long-baseline neutrino
experiment. The mean energy of the incident muon neutrinos is 1.3 GeV. The data
used in this analysis are mainly from a fully active scintillator detector,
SciBar. The cross section for single production in the resonance
region ( GeV/) relative to the charged-current quasi-elastic cross
section is found to be 0.734 . The energy-dependent cross
section ratio is also measured. The results are consistent with a previous
experiment and the prediction of our model.Comment: 15 pages, 12 figures, 7 tables. Uses revtex4. Minor revisions to
match version accepted for publication in Physical Review
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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