10 resultados para State, The
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
The photophysics of 8-azaadenine (8-AA) has been studied with the CASPT2//CASSCF protocol and ANO-L double-zeta basis sets. Stationary equilibrium structures, surface crossings, minimum energy paths, and linear interpolations have been used to study possible mechanisms to populate the lowest triplet state, T-1 (3)(pi pi*), capable of sensitizing molecular oxygen. Our results show that two main mechanisms can occur after photoexcitation to the S-2 (1)(pi pi*) state. The first one is through the S-2/S-1 conical intersection (((1)pi pi*/(1)n pi*)(Cl)), leading to the S-1 ((1)n pi*) state minimum, (S-1 ((1)n pi*))(min), where a singlet-triplet crossing, ((1)n pi*/(3)pi pi*)(STC), is accessible. The second one starts with the ((1)pi pi*/(3)n pi*)(STC) at the (S-2((1)pi pi*))(min), from which the system can evolve to the (T-2 ((3)n pi*))(min), with subsequent population of the T-1 excited electronic state, due to the ((3)n pi*/(3)pi pi*)(Cl) conical intersection.
Resumo:
The ATLAS and CMS collaborations have recently shown data suggesting the presence of a Higgs boson in the vicinity of 125 GeV. We show that a two-Higgs-doublet model spectrum, with the pseudoscalar state being the lightest, could be responsible for the diphoton signal events. In this model, the other scalars are considerably heavier and are not excluded by the current LHC data. If this assumption is correct, future LHC data should show a strengthening of the gamma gamma signal, while the signals in the ZZ(()*()) -> 4l and WW(*()) -> 2l2 nu channels should diminish and eventually disappear, due to the absence of diboson tree-level couplings of the CP-odd state. The heavier CP-even neutral scalars can now decay into channels involving the CP-odd light scalar which, together with their larger masses, allow them to avoid the existing bounds on Higgs searches. We suggest additional signals to confirm this scenario at the LHC, in the decay channels of the heavier scalars into AA and AZ. Finally, this inverted two-Higgs-doublet spectrum is characteristic in models where fermion condensation leads to electroweak symmetry breaking. We show that in these theories it is possible to obtain the observed diphoton signal at or somewhat above the prediction for the standard model Higgs for the typical values of the parameters predicted.
Resumo:
This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondonia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An. gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon.
Resumo:
Aspects of phlebotomine behavior were investigated in the city of Campo Grande, Mato Grosso do Sul state. The insects were captured weekly during December 2003 to November 2005, with Centers for Disease Control light traps at seven different sites including forests and residential areas. In total, 11,024 specimens (7,805 males and 3,219 females) were collected, from which 9,963 (90.38%) were identified as Lutzomyia longipalpis, the proven vector of American visceral leishmaniasis agent. The remaining 9.62% comprised 21 species. L. longipalpis was the most frequent species in all sampled sites, and the first in the ranking of standardized species abundance index. In residential areas this species clearly predominated in the peridomicile (90.96%), in contrast to the intradomicile (9.04%); in animal shelters, it was more numerous in hen houses and prevailed at ground level, inside, and at forest edge around the residences; this aspect is worrying because this insect may remain sheltered in forested environments during the use of insecticides in homes. In the forest environment, other probable or proven vector of cutaneous leishmaniasis agents were also captured such as Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati), Lutzomyia antunesi (=Nyssomyia antunesi, sensu Galati), and Lutzomyia flaviscutellata (=Bichromomyia flaviscutellata, sensu Galati).
Resumo:
In this contribution, the multiconfigurational second-order perturbation theory method based on a complete active space reference wave function (CASSCF/CASPT2) is applied to study all possible single and double proton/hydrogen transfers between the nucleobases in the adenine-thymine (AT) base pair, analyzing the role of excited states with different nature [localized (LE) and charge transfer (CT)] and considering concerted as well as step-wise mechanisms. According to the findings, once the lowest excited states, localized in adenine, are populated during UV irradiation of the Watson-Crick base pair, the proton transfer in the N-O bridge does not require high energy in order to populate a CT state. The latter state will immediately relax toward a crossing with the ground state, which will funnel the system to either the canonical structure or the imino-enol tautomer. The base pair is also capable of repairing itself easily since the imino-enol species is unstable to thermal conversion.
Resumo:
Measurement-based quantum computation is an efficient model to perform universal computation. Nevertheless, theoretical questions have been raised, mainly with respect to realistic noise conditions. In order to shed some light on this issue, we evaluate the exact dynamics of some single-qubit-gate fidelities using the measurement-based quantum computation scheme when the qubits which are used as a resource interact with a common dephasing environment. We report a necessary condition for the fidelity dynamics of a general pure N-qubit state, interacting with this type of error channel, to present an oscillatory behavior, and we show that for the initial canonical cluster state, the fidelity oscillates as a function of time. This state fidelity oscillatory behavior brings significant variations to the values of the computational results of a generic gate acting on that state depending on the instants we choose to apply our set of projective measurements. As we shall see, considering some specific gates that are frequently found in the literature, the fast application of the set of projective measurements does not necessarily imply high gate fidelity, and likewise the slow application thereof does not necessarily imply low gate fidelity. Our condition for the occurrence of the fidelity oscillatory behavior shows that the oscillation presented by the cluster state is due exclusively to its initial geometry. Other states that can be used as resources for measurement-based quantum computation can present the same initial geometrical condition. Therefore, it is very important for the present scheme to know when the fidelity of a particular resource state will oscillate in time and, if this is the case, what are the best times to perform the measurements.
Resumo:
The Strategic Environmental Assessment (SEA) of the sugar and alcohol sector guides a territorial and sectoral planning that benefits most of the local society and supports this economic activity in all its stages. In this way, the present work aims to determine an index of aggregation of the indicators generated in the baseline of the SEA process, called Index of Sustainability of Expansion of the Sugar and Alcohol Sector (IScana). For this, it was used the normalization of the indicators of each city by the fuzzy logic and attribution of weights by the Analytic Hierarchy Process (AHP). Then, the IScana values had been spatialized in the region of 'Grande Dourados'-Mato Grosso do Sul State. The northern portion concentrated the highest values of IScana, 0.48 and 0.55, referring to the cities of Nova Alvorada do Sul and Rio Brilhante, while, in the central portion, the city of Dourados presented the lowest value, 0.10. The selection of the set of indicators forming the IScana, and their relative importance, was satisfactory for the application of fuzzy logic and AHP techniques. The IScana index supplies objective information regarding the diagnosis of the region for the application of SEA.
Resumo:
CHARACTERIZATION OF REGOSOLS IN THE SEMIARID REGION OF PERNAMBUCO, BRAZIL Studies on soil characterization in unexplored regions, besides the generation of data banks for the soil classes of the country, also produce scientific information about soil properties, important for the development of good management practices and sustainable land use. One of the main soil classes in the semiarid region of Pernambuco State, the Regosols, cover about 27 % of the state area, and are used mainly for family agriculture. Due to different geological and climatic aspects Regosols with different chemical, physical and mineralogical properties are found in Pernambuco, which were characterized for the semiarid region of the State. Five Regosol profiles were selected in different regions of the State (P1=Sao Caetano; P2=Lagoa do Ouro; P3=Caetes; P4=Sao Joao; P5=Parnamirim). The soils were morphologically characterized and samples collected from all horizons and the bedrock. Routine physical and chemical analyses were carried out for soil classification of all samples and mineralogical analyses of the coarse fractions (gravel and sand) by optical microscopy and of the silt and clay fractions by X ray diffraction (XRD), as well as petrographic analyses of the rock samples. The results showed similarities between the soils, with a low degree of pedogenetic development, varying from medium to very deep, with the horizon sequence A-AC-C-Cr and a sandy to sandy loam texture. In the deeper layers of two profiles (P1 and P5), a solodic character was observed. Organic matter and available phosphorus content were low in all studied soils. Despite the low levels of exchangeable cations, all soil profiles showed high base saturation. The mineralogical composition of gravel, sand and silt fractions consisted, essentially, of quartz, followed by feldspars and mica, supporting the results of the petrographic analysis of the bedrock. Kaolinite was the main clay mineral in all studied profiles and horizons, indicating an important monosialitization process in autochthonous soils of a typical semiarid region. In soil profile P2, at a lower landscape position, smectite minerals were observed, with mixing phases of montmorillonite, beidelite or nontronite, indentified by the Greene-Kelly test in the DRX analysis.
Resumo:
This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondônia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon.
Resumo:
The Brazilian eastern coast has one of the biggest coral reefs of the Atlantic Ocean, denominated Abrolhos Bank, situated in the southern region of the Bahia state. The Caravelas estuary, also located in the south of Bahia, is considered an important ecological balance zone, due to its proximity to Abrolhos Bank and occurrence of mangroves. Thus, any natural or anthropogenic impact may bring environmental transformation on this region, which is considered the most important marine biodiversity reserve in the Southwestern Atlantic Ocean (Travassos et al., 2004)