EMBRAPA lança novas variedades de mandioca tolerantes ao mal da podridão mole.

bitstream/item/42278/1/Id39826.pdfFonte: Izabel Drulla Brandão, CPATU

Testing excitation models of rapidly oscillating Ap stars with interferometry

Rapidly oscillating Ap stars are unique objects in the potential they offer to study the interplay between a number of important physical phenomena, in particular, pulsations, magnetic fields, diffusion, and convection. Nevertheless, the simple understanding of how the observed pulsations are excited in these stars is still in progress. In this work we perform a test to what is possibly the most widely accepted excitation theory for this class of stellar pulsators. The test is based on the study of a subset of members of this class for which stringent data on the fundamental parameters are available thanks to interferometry. For three out of the four stars considered in this study, we find that linear, non-adiabatic models with envelope convection suppressed around the magnetic poles can reproduce well the frequency region where oscillations are observed. For the fourth star in our sample no agreement is found, indicating that a new excitation mechanism must be considered. For the three stars whose observed frequencies can be explained by the excitation models under discussion, we derive the minimum angular extent of the region where convection must be suppressed. Finally, we find that the frequency regions where modes are expected to be excited in these models is very sensitive to the stellar radius. This opens the interesting possibility of determining this quantity and related ones, such as the effective temperature or luminosity, from comparison between model predictions and observations, in other targets for which these parameters are not well determined.Comment: Accepted for publication in the MNRA

Measuring the extent of convective cores in low-mass stars using Kepler data: towards a calibration of core overshooting

Our poor understanding of the boundaries of convective cores generates large uncertainties on the extent of these cores and thus on stellar ages. Our aim is to use asteroseismology to consistently measure the extent of convective cores in a sample of main-sequence stars whose masses lie around the mass-limit for having a convective core. We first test and validate a seismic diagnostic that was proposed to probe in a model-dependent way the extent of convective cores using the so-called $r_{010}$ ratios, which are built with $l=0$ and $l=1$ modes. We apply this procedure to 24 low-mass stars chosen among Kepler targets to optimize the efficiency of this diagnostic. For this purpose, we compute grids of stellar models with both the CESAM2k and MESA evolution codes, where the extensions of convective cores are modeled either by an instantaneous mixing or as a diffusion process. Among the selected targets, we are able to unambiguously detect convective cores in eight stars and we obtain seismic measurements of the extent of the mixed core in these targets with a good agreement between the CESAM2k and MESA codes. By performing optimizations using the Levenberg-Marquardt algorithm, we then obtain estimates of the amount of extra-mixing beyond the core that is required in CESAM2k to reproduce seismic observations for these eight stars and we show that this can be used to propose a calibration of this quantity. This calibration depends on the prescription chosen for the extra-mixing, but we find that it should be valid also for the code MESA, provided the same prescription is used. This study constitutes a first step towards the calibration of the extension of convective cores in low-mass stars, which will help reduce the uncertainties on the ages of these stars.Comment: 27 pages, 15 figures, accepted in A&

Orofacial manifestations in outpatients with anorexia nervosa and bulimia nervosa focusing on the vomiting behavior

Objective: This case-control study aims to evaluate the oral health status and orofacial problems in a group of outpatients with eating disorders (ED)—either anorexia nervosa (AN) or bulimia nervosa (BN)—further focusing on the influence of vomit. Materials and methods: Fifty-five women outpatients with AN or BN diagnosis were invited to participate, of which 33 agreed. ED outpatients and matched controls were submitted to a questionnaire and clinical oral examination. Results: Multivariate analysis identified a significantly higher incidence of teeth-related complications (i.e., tooth decay, dental erosion, and self-reported dentin hypersensitivity), periodontal disease, salivary alterations (i.e., hyposalivation and xerostomia), and oral mucosa-related complications in ED outpatients. Dental erosion, self-reported dentin hypersensitivity, hyposalivation, xerostomia, and angular cheilitis were found to be highly correlated with the vomiting behavior. Conclusions: ED outpatients were found to present a higher incidence of oral-related complications and an inferior oral health status, compared to gender- and age-matched controls. Alterations verified within outpatients were acknowledged to be quite similar to those previously reported within inpatients, in both of nature and severity, thus sustaining that the cranio-maxillofacial region is significantly affected by ED, even in the early/milder forms of the condition, as expectedly verified within outpatients.The work was supported by the Faculty of Dental Medicine, U. Porto

Annular elastolytic giant cell granuloma: a "visible" diagnosis

Annular elastolytic giant cell granuloma (AEGCG) is a rare granulomatous skin disease of undetermined cause, characterized by annular plaques with raised erythematous borders in sun-exposed skin. The typical histologic features are dermal infiltration by multinucleated giant cells, elastin degeneration, and elastophagocytosis. The authors describe a clinical case of AEGCG, which exhibited an excellent response to hydroxycloroquine.info:eu-repo/semantics/publishedVersio

Efficient UC Commitment Extension with Homomorphism for Free (and Applications)

Homomorphic universally composable (UC) commitments allow for the sender to reveal the result of additions and multiplications of values contained in commitments without revealing the values themselves while assuring the receiver of the correctness of such computation on committed values. In this work, we construct essentially optimal additively homomorphic UC commitments from any (not necessarily UC or homomorphic) extractable commitment. We obtain amortized linear computational complexity in the length of the input messages and rate 1. Next, we show how to extend our scheme to also obtain multiplicative homomorphism at the cost of asymptotic optimality but retaining low concrete complexity for practical parameters. While the previously best constructions use UC oblivious transfer as the main building block, our constructions only require extractable commitments and PRGs, achieving better concrete efficiency and offering new insights into the sufficient conditions for obtaining homomorphic UC commitments. Moreover, our techniques yield public coin protocols, which are compatible with the Fiat-Shamir heuristic. These results come at the cost of realizing a restricted version of the homomorphic commitment functionality where the sender is allowed to perform any number of commitments and operations on committed messages but is only allowed to perform a single batch opening of a number of commitments. Although this functionality seems restrictive, we show that it can be used as a building block for more efficient instantiations of recent protocols for secure multiparty computation and zero knowledge non-interactive arguments of knowledge

Faithful Squashed Entanglement

Squashed entanglement is a measure for the entanglement of bipartite quantum states. In this paper we present a lower bound for squashed entanglement in terms of a distance to the set of separable states. This implies that squashed entanglement is faithful, that is, strictly positive if and only if the state is entangled. We derive the bound on squashed entanglement from a bound on quantum conditional mutual information, which is used to define squashed entanglement and corresponds to the amount by which strong subadditivity of von Neumann entropy fails to be saturated. Our result therefore sheds light on the structure of states that almost satisfy strong subadditivity with equality. The proof is based on two recent results from quantum information theory: the operational interpretation of the quantum mutual information as the optimal rate for state redistribution and the interpretation of the regularised relative entropy of entanglement as an error exponent in hypothesis testing. The distance to the set of separable states is measured by the one-way LOCC norm, an operationally-motivated norm giving the optimal probability of distinguishing two bipartite quantum states, each shared by two parties, using any protocol formed by local quantum operations and one-directional classical communication between the parties. A similar result for the Frobenius or Euclidean norm follows immediately. The result has two applications in complexity theory. The first is a quasipolynomial-time algorithm solving the weak membership problem for the set of separable states in one-way LOCC or Euclidean norm. The second concerns quantum Merlin-Arthur games. Here we show that multiple provers are not more powerful than a single prover when the verifier is restricted to one-way LOCC operations thereby providing a new characterisation of the complexity class QMA.Comment: 24 pages, 1 figure, 1 table. Due to an error in the published version, claims have been weakened from the LOCC norm to the one-way LOCC nor