Simplicity of Partial Crossed Products

In this article, we consider a twisted partial action $\alpha$ of a group $G$ on a ring $R$ and it is associated partial crossed product $R*_{\alpha}^wG$. We study necessary and sufficient conditions for the commutativity and simplicity of $R*_{\alpha}^wG$. Let $R=C(X)$ the algebra of continuous functions of a topological space $X$ on the complex numbers and $C(X)*_{\alpha}G$ the partial skew group ring, where $\alpha$ is a partial action of a topological group $G$ on $C(X)$. We study some topological properties to obtain results on the algebra $C(X)$. Also, we study the simplicity of $C(X)*_{\alpha}G$ using topological properties and the results about the simplicity of partial crossed product obtained for $R*_{\alpha}^wG$.Comment: Submitted for publication in 06/0

Global Hypoellipticity for Strongly Invariant Operators

In this note, by analyzing the behavior at infinity of the matrix symbol of an invariant operator $P$ with respect to a fixed elliptic operator, we obtain a necessary and sufficient condition to guarantee that $P$ is globally hypoelliptic. We also investigate relations between the global hypoellipticity of $P$ and global subelliptic estimates.Comment: 20 page

Improved estimators for dispersion models with dispersion covariates

In this paper we discuss improved estimators for the regression and the dispersion parameters in an extended class of dispersion models (J{\o}rgensen, 1996). This class extends the regular dispersion models by letting the dispersion parameter vary throughout the observations, and contains the dispersion models as particular case. General formulae for the second-order bias are obtained explicitly in dispersion models with dispersion covariates, which generalize previous results by Botter and Cordeiro (1998), Cordeiro and McCullagh (1991), Cordeiro and Vasconcellos (1999), and Paula (1992). The practical use of the formulae is that we can derive closed-form expressions for the second-order biases of the maximum likelihood estimators of the regression and dispersion parameters when the information matrix has a closed-form. Various expressions for the second-order biases are given for special models. The formulae have advantages for numerical purposes because they require only a supplementary weighted linear regression. We also compare these bias-corrected estimators with two different estimators which are also bias-free to the second-order that are based on bootstrap methods. These estimators are compared by simulation

Autoantibodies in systemic vasculitis

Systemic vas culitis is a heterogeneous group of disorders characterized by inflammation and necrosis in the vessel wall. the diagnosis of a systemic vasculitis is challenging, because patients usually present a broad spectrum of manifestations that vary according to the predominant size of vessels affected, organs and systems involved, and the extent of the inflammatory process (I). in systemic vasculitis, disease manifestations usually cluster into clinical phenotypes and definite diagnosis rely on confirmation by tissue biopsy, angiography, or by serologic tests. However, when a systemic vasculitis is under investigation, it is of paramount importance to keep in mind vasculitis mimics (e.g., genetic vascular disorders and atheroembolic diseases) and secondary causes (i.e., infections, malignancy, connective tissue disorders, or drugs) (2).The main serologic tests for the diagnosis of primary systemic vasculitides are antineutrophil cytoplasmic antibodies (ANCA), cryoglobulins, anti-glomerular basement membrane (anti-GBM) antibodies, and anti-Clq antibodies (3). Although, several other autoantibodies have been investigated in systemic vasculitis, the clinical usefulness of these antibodies still needs further investigation (Table 1). Herein, the main autoantibodies and their clinical associations in systemic vasculitis are reviewed.Universidade Federal de São Paulo, Escola Paulista Med, Dept Internal Med, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Internal Med, Div Rheumatol, São Paulo, BrazilWeb of Scienc

Epistemic beliefs of Norwegian history student teachers: Testing and assessing two measurement instruments

Since teachers’ and students’ epistemic beliefs about history are believed to significantly impact teachers’ practices, students’ performance and the ability to think historically of both, investigating such beliefs is important. Following the seminal works of Maggioni and colleagues (Maggioni, 2010; Maggioni et al., 2004; Maggioni et al., 2009), a number of studies have adapted versions of her Beliefs About Learning and Teaching History Questionnaire (BLTHQ) and Beliefs about History Questionnaire (BHQ) to quantitatively evaluate epistemic beliefs in different national contexts (Mierwald et al., 2016; Miguel-Revilla et al., 2017; Namamba & Rao, 2016; Nitsche, 2019; Stoel, Logtenberg, et al., 2017). However, the validity and reliability of these instruments have mostly been found to be problematic (Mierwald & Junius, 2022; Stoel et al., 2022). We have tested two different questionnaires – Maggioni’s BLTHQ and our own adaptation of the BHQ ¬– in separate surveys, on respectively 176 and 324 Norwegian history student teachers. For both questionnaires, our exploratory analysis showed a three-factor solution, supporting King and Kitchener’s (1994) model, and undermining the two-factor solutions found in many former studies. However, despite both questionnaires showing acceptable consistency and fitness, these levels were not optimal, and confirmed the problem of epistemic inconsistency (or ‘wobbling’) revealed by previous studies. These results encourage further qualitative studies to better understand the problem of wobbling, to design better questionnaires to be tested in the future.publishedVersio

Polycyclic aromatic hydrocarbons (PAHS) in cachaça, rum, whiskey and alcohol fuel

The concentration of 15 polycyclic aromatic hydrocarbons (PAHs) in 57 samples of distillates (cachaça, rum, whiskey, and alcohol fuel) has been determined by HPLC-Fluorescence detection. The quantitative analytical profile of PAHs treated by Partial Least Square - Discriminant Analysis (PLS-DA) provided a good classification of the studied spirits based on their PAHs content. Additionally, the classification of the sugar cane derivatives according to the harvest practice was obtained treating the analytical data by Linear Discriminant Analysis (LDA), using naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benz[b]fluoranthene, and benz[g,h,i]perylene, as a chemical descriptors.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPES