Patologia de sementes de cereais de inverno.

bitstream/item/128960/1/ID-38429-1987-LV-patologiasementescereaisinverno.pd

An axiomatic characterization of ensconcement-based contraction

In this article, we propose an axiomatic characterization for ensconcement-based contraction functions, belief base functions proposed by Williams. We relate this function with other kinds of base contraction functions.info:eu-repo/semantics/publishedVersio

On the search for the chiral anomaly in Weyl semimetals: The negative longitudinal magnetoresistance

Recently, the existence of massless chiral (Weyl) fermions has been postulated in a class of semi-metals with a non-trivial energy dispersion.These materials are now commonly dubbed Weyl semi-metals (WSM).One predicted property of Weyl fermions is the chiral or Adler-Bell-Jackiw anomaly, a chirality imbalance in the presence of parallel magnetic and electric fields. In WSM, it is expected to induce a negative longitudinal magnetoresistance (NMR), the chiral magnetic effect.Here, we present experimental evidence that the observation of the chiral magnetic effect can be hindered by an effect called "current jetting". This effect also leads to a strong apparent NMR, but it is characterized by a highly non-uniform current distribution inside the sample. It appears in materials possessing a large field-induced anisotropy of the resistivity tensor, such as almost compensated high-mobility semimetals due to the orbital effect.In case of a non-homogeneous current injection, the potential distribution is strongly distorted in the sample.As a consequence, an experimentally measured potential difference is not proportional to the intrinsic resistance.Our results on the MR of the WSM candidate materials NbP, NbAs, TaAs, TaP exhibit distinct signatures of an inhomogeneous current distribution, such as a field-induced "zero resistance' and a strong dependence of the `measured resistance" on the position, shape, and type of the voltage and current contacts on the sample. A misalignment between the current and the magnetic-field directions can even induce a "negative resistance". Finite-element simulations of the potential distribution inside the sample, using typical resistance anisotropies, are in good agreement with the experimental findings. Our study demonstrates that great care must be taken before interpreting measurements of a NMR as evidence for the chiral anomaly in putative Weyl semimetals.Comment: 13 pages, 6 figure

The roles of culture, gender norms, and sexual orientation in intimate partner violence: Psychosocial variables associated with IPV in a Portuguese sample

Intimate partner violence (IPV) has been recognized as a threat to the well-being of women and men in different-sex and same-sex relationships worldwide. Research on this topic has been increasing, but more information on the variables associated with IPV may improve responses to IPV prevention and intervention. With this study, we aim to analyze the relationship between psychosocial variables and frequency of IPV, in potential male and female victims in different-sex and same-sex relationships. Three hundred four participants (232 women—76.3%; 72 men—23.7%) were recruited via an online survey, and inquired on sociodemographic data, suffered violence using the Conflict Tactics Scale-2 (CTS-2), and psychosocial variables (e.g., familiar isolation, self-esteem, selfblame, dependence). Overall, higher frequency of violence was associated with higher family and social isolation for both female and male participants. For female participants, a model that considers both sociodemographic variables and psychosocial ones (e.g., social isolation, submission, dependence) best predicted frequency of experienced violence (R2 = 33.1%). For males, only three psychosocial variables predicted experienced violence (e.g., social and familiar isolation, and submission), and retained more explicative power (R2 = 41.3%). No significant differences were found in the victimization between victims in different-sex and same-sex relationships, but family isolation was higher in same-sex relationships. Our findings shed light on relevant variables and their potential contribution to explain the frequency of violence among male and female participants, in different and same-sex relationships. Future prevention and treatment interventions could be improved by taking into consideration the relevance of these variables.info:eu-repo/semantics/acceptedVersio

Conflict between religious/spiritual and LGB identities in Portugal: How is it related to coming out experiences, LGB identity dimensions and well-being?

Even though Lesbian, Gay, and Bisexual (LGB) individuals are usually less religious than the general population, religion and/or spirituality are still a part of many LGB people’s lives. This article focused on investigating the relation between the conflict between religious/spiritual and LGB identities and subjective well-being, dimensions of LGB identity and outness, in a Portuguese sample. The participants were 126 LGB people, with 80 of them being female, from a mostly Catholic context in Southern Europe—Portugal. Conflict between religious and LGB identities was found to be significantly and negatively correlated with outness and positive affect; and positively correlated with negative affect and some LGB identity dimensions, Internalized Homonegativity, Difficult Process (DP), Acceptance Concerns (AC), and Concealment Motivation (CM). People who felt conflict between their religious/spiritual and LGB identities were found to have higher scores on DP, AC, CM, and Identity Centrality than those who did not experience it. Implications are discussed in terms of the diversity of strategies LGB people use to reconcile their dual identities.info:eu-repo/semantics/acceptedVersio

Testing the Equivalence of Regular Languages

The minimal deterministic finite automaton is generally used to determine regular languages equality. Antimirov and Mosses proposed a rewrite system for deciding regular expressions equivalence of which Almeida et al. presented an improved variant. Hopcroft and Karp proposed an almost linear algorithm for testing the equivalence of two deterministic finite automata that avoids minimisation. In this paper we improve the best-case running time, present an extension of this algorithm to non-deterministic finite automata, and establish a relationship between this algorithm and the one proposed in Almeida et al. We also present some experimental comparative results. All these algorithms are closely related with the recent coalgebraic approach to automata proposed by Rutten

Performance of robust estimators: Sampling, variables and dimensions

The use of data collected from market research and opinion surveys is common in social and business areas. Probability samples are usually the first option for data collection though they are quite often excluded due to the non existence of a suitable sampling frame. In addition to the lack of randomness of sample data, further problems are caused by inadequate sample representativeness for some population characteristics, limitations of the measuring instrument and occurrence of measurement errors. In these situations, robust statistical techniques can be a valid option for estimation purposes as they are not sensitive to sample biases. The main aim of this study is to evaluate the performance of robust estimators, particularly Huber M-estimator, Tukey's biweight and Least Trimmed Squares (LTS) estimators, when compared to the sample mean and median, and applied to different types of variables, diverse sampling methods and dimensions. Quantitative and qualitative ordinal Likert type variables with 4, 6 and 10 point were used. Samples were generated by stratified and quota methods, both with dimensions 50, 100 and 300. Results show the best behavior of the Huber and the Tukey's biweight estimators in most situations, particularly for quantitative variables, for both sample methods. The LTS estimator performed worse than any other estimator, being better solely in the case of ordinal variables with a 4 point scale, sharp skewness and high kurtosis.info:eu-repo/semantics/publishedVersio

Studies on brutal contraction and severe withdrawal

In this paper we present an axiomatic characterization for brutal contractions. Then we consider the particular case of the brutal contractions that are based on a bounded ensconcement and also the class of severe withdrawals which are based on bounded epis temic entrenchment relations that are defined by means of bounded ensconcements (using the procedure proposed by Mary-Anne Williams). We present axiomatic characterizations for each one of those classes of functions and investigate the interrelation among them.info:eu-repo/semantics/publishedVersio

Modified Bristow-Latarjet procedure for treatment of recurrent traumatic anterior glenohumeral dislocation

Retrospective case-control study of authors experience in the modified Bristow-Latarjet procedure for treatment of recurrent traumatic anterior glenohumeral dislocation with glenoid bone injury.info:eu-repo/semantics/publishedVersio