Parent Actions, Dualities and New Weyl-invariant Actions of Bosonic p-branes

By using the systematic approach of parent action method, we derive one Weyl-noninvariant and two Weyl-invariant actions of bosonic $p$-branes ($p\geq 2$) starting from the Nambu-Goto action, and establish the duality symmetries in this set of four actions. Moreover, we discover a new bosonic $p$-brane action (including the string theory) and deduce two corresponding Weyl-invariant formulations by proposing a new special parent action. We find that the same duality symmetries as those mentioned above exist in this new set of actions. The new $p$-brane actions are also briefly analyzed.Comment: 19 pages, 14 figures. The first section is modified slightly, and references are adde

Adaptation of International Accounting Standards: Case of Portugal

This chapter aims to present the results of a broad analysis about the process of accounting standardization in Portugal in order to frame the current situation and the different levels of standardization that characterize it. The methodology followed involves a broad revision of the literature and content analysis on various papers and texts as well on documents directly related with the study topic. It concludes with the identification and characterization of the current levels of accounting standardization and makes reference to the likely scenario of this regulatory framework in the short term. The objective is to understand how the evolution of accounting standards in Portugal has evolved, what the current situation is and its likely evolution in the near future. The chapter is also aimed at contributing to the understanding of the process of adaptation of international accounting standards to the Portuguese reality

DNA vaccines against dengue virus based on the ns1 gene: The influence of different signal sequences on the protein expression and its correlation to the immune response elicited in mice

AbstractWe analyzed four DNA vaccines based on DENV-2 NS1: pcENS1, encoding the C-terminal from E protein plus the NS1 region; pcENS1ANC, similar to pcENS1 plus the N-terminal sequence from NS2a (ANC); pcTPANS1, coding the t-PA signal sequence fused to NS1; and pcTPANS1ANC, similar to pcTPANS1 plus the ANC sequence. The NS1 was detected in lysates and culture supernatants from pcTPANS1-, pcENS1- and pcENS1ANC-transfected cells and not in cells with pcTPANS1ANC. Only the pcENS1ANC leads the expression of NS1 in plasma membrane, confirming the importance of ANC sequence for targeting NS1 to cell surface. High levels of antibodies recognizing conformational epitopes of NS1 were induced in mice immunized with pcTPANS1 and pcENS1, while only few pcENS1ANC-inoculated animals presented detectable anti-NS1 IgG. Protection against DENV-2 was verified in pcTPANS1- and pcENS1-immunized mice, although the plasmid pcTPANS1 induced slight higher protective immunity. These plasmids seem to activate distinct patterns of the immune system

Relationship between impairments of long-lived assets and earnings management: study for large portuguese companies

Objective: The aim of the present work is to analyze the relationship between the assets impairment and earnings management, since this has been a major discussion topic in literature over the years. Thus, this relationship is analyzed studying the large Portuguese companies. Methodology: Based on 464 observations from large Portuguese companies, between 2010 and 2018, we sought to identify which earnings management practices exist and what are the main characteristics of companies related to the level of impairments recorded. Originality: To the best of our knowledge this is the firstwork that relates the value of impairments of long-lived assets with earnings management for Portuguese companies. Results: The results indicate the existence of earnings management using income smoothing and big-bath practices among the sample companies. We also conclude that companies with income smoothing practices and with lower return on assets are those with a higher impairment value recorded, and the big-bath practices do not explain this value. Practical Implications: The results of this study contribute to a greater understanding of earnings management practices in large companies in countries with continental influence. This is consistent with the importance of banking and tax administration as the main users of financial information in this context.info:eu-repo/semantics/publishedVersio

Influence of ink rheology and post processing in the structural performance of silicon nitride-based ceramics fabricated by robocasting

The fabrication of complex shaped Si3N4 parts by conventional methods is challenging due to its high hardness and mechanical strength. Additive manufacturing (AM) appeared as a competitive way to attain three-dimensional complexity at lower costs. However, most of AM technologies still present limitations in producing high dense ceramics, mainly due to several difficulties in developing proper feedstock. This work presents the fabrication of dense silicon nitride-based ceramics by using an extrusion based additive manufacturing technique (direct ink writing, also known as robocasting) and cold isostatic pressing (CIP) as a post processing step. Silicon-nitride aqueous based inks containing different amounts of solids loading (36, 38 and 39 vol%) and proper rheological characteristics for the printing process were studied. The use of CIP (200 MPa) is suggested to reduce or even eliminate defects and porosity and consequently, to improve mechanical performance of the final parts. Relative density, microhardness and flexural strength increased as solids loading in the inks increased and were further improved when CIP pressing was used. Parts produced by robocasting with an ink containing 39 vol% and cold isostatic pressed at 200 MPa exhibited an average relative density around 99%, 1475 HV2 microhardness value and 650 MPa flexural strength, values similar to those of silicon nitride ceramics fabricated by conventional processing.publishe

Conformal p-branes as a Source of Structure in Spacetime

We discuss a model of a conformal p-brane interacting with the world volume metric and connection. The purpose of the model is to suggest a mechanism by which gravity coupled to p-branes leads to the formation of structure rather than homogeneity in spacetime. Furthermore, we show that the formation of structure is accompanied by the appearance of a multivalued cosmological constant, i.e., one which may take on different values in different domains, or cells, of spacetime. The above results apply to a broad class of non linear gravitational lagrangians as long as metric and connection on the p-brane manifold are treated as independent variables.Comment: 10 pages, ReVTeX, no figure

Palatini approach to 1/R gravity and its implications to the late Universe

By applying the Palatini approach to the 1/R-gravity model it is possible to explain the present accelerated expansion of the Universe. Investigation of the late Universe limiting case shows that: (i) due to the curvature effects the energy-momentum tensor of the matter field is not covariantly conserved; (ii) however, it is possible to reinterpret the curvature corrections as sources of the gravitational field, by defining a modified energy-momentum tensor; (iii) with the adoption of this modified energy-momentum tensor the Einstein's field equations are recovered with two main modifications: the first one is the weakening of the gravitational effects of matter whereas the second is the emergence of an effective varying "cosmological constant"; (iv) there is a transition in the evolution of the cosmic scale factor from a power-law scaling $a\propto t^{11/18}$ to an asymptotically exponential scaling $a\propto \exp(t)$; (v) the energy density of the matter field scales as $\rho_m\propto (1/a)^{36/11}$; (vi) the present age of the Universe and the decelerated-accelerated transition redshift are smaller than the corresponding ones in the $\Lambda$CDM model.Comment: 5 pages and 2 figures. Accepted in PR

Insulin therapy modulates mitochondrial dynamics and biogenesis, autophagy and tau protein phosphorylation in the brain of type 1 diabetic rats

AbstractThe main purpose of this study was to examine whether streptozotocin (STZ)-induced type 1 diabetes (T1D) and insulin (INS) treatment affect mitochondrial function, fission/fusion and biogenesis, autophagy and tau protein phosphorylation in cerebral cortex from diabetic rats treated or not with INS. No significant alterations were observed in mitochondrial function as well as pyruvate levels, despite the significant increase in glucose levels observed in INS-treated diabetic rats. A significant increase in DRP1 protein phosphorylated at Ser616 residue was observed in the brain cortex of STZ rats. Also an increase in NRF2 protein levels and in the number of copies of mtDNA were observed in STZ diabetic rats, these alterations being normalized by INS. A slight decrease in LC3-II levels was observed in INS-treated rats when compared to STZ diabetic animals. An increase in tau protein phosphorylation at Ser396 residue was observed in STZ diabetic rats while INS treatment partially reversed that effect. Accordingly, a modest reduction in the activation of GSK3β and a significant increase in the activity of phosphatase 2A were found in INS-treated rats when compared to STZ diabetic animals. No significant alterations were observed in caspases 9 and 3 activity and synaptophysin and PSD95 levels. Altogether our results show that mitochondrial alterations induced by T1D seem to involve compensation mechanisms since no significant changes in mitochondrial function and synaptic integrity were observed in diabetic animals. In addition, INS treatment is able to normalize the alterations induced by T1D supporting the importance of INS signaling in the brain

Have the cake and eat it: optimizing nondestructive DNA metabarcoding of macroinvertebrate samples for freshwater biomonitoring

Resource ArticleDNA metabarcoding can contribute to improving cost‐effectiveness and accuracy of biological assessments of aquatic ecosystems, but significant optimization and standardization efforts are still required to mainstream its application into biomonitoring programmes. In assessments based on freshwater macroinvertebrates, a key challenge is that DNA is often extracted from cleaned, sorted and homogenized bulk samples, which is time‐consuming and may be incompatible with sample preservation requirements of regulatory agencies. Here, we optimize and evaluate metabarcoding procedures based on DNA recovered from 96% ethanol used to preserve field samples and thus including potential PCR inhibitors and nontarget organisms. We sampled macroinvertebrates at five sites and subsampled the preservative ethanol at 1 to 14 days thereafter. DNA was extracted using column‐based enzymatic (TISSUE) or mechanic (SOIL) protocols, or with a new magnetic‐based enzymatic protocol (BEAD), and a 313‐bp COI fragment was amplified. Metabarcoding detected at least 200 macroinvertebrate taxa, including most taxa detected through morphology and for which there was a reference barcode. Better results were obtained with BEAD than SOIL or TISSUE, and with subsamples taken 7–14 than 1–7 days after sampling, in terms of DNA concentration and integrity, taxa diversity and matching between metabarcoding and morphology. Most variation in community composition was explained by differences among sites, with small but significant contributions of subsampling day and extraction method, and negligible contributions of extraction and PCR replication. Our methods enhance reliability of preservative ethanol as a potential source of DNA for macroinvertebrate metabarcoding, with a strong potential application in freshwater biomonitoringinfo:eu-repo/semantics/publishedVersio

Differential gene expression profiles of hepatocellular carcinomas associated or not with viral infection

Chronic hepatitis B (HBV) and C (HCV) virus infections are the most important factors associated with hepatocellular carcinoma (HCC), but tumor prognosis remains poor due to the lack of diagnostic biomarkers. In order to identify novel diagnostic markers and therapeutic targets, the gene expression profile associated with viral and non-viral HCC was assessed in 9 tumor samples by oligo-microarrays. The differentially expressed genes were examined using a z-score and KEGG pathway for the search of ontological biological processes. We selected a non-redundant set of 15 genes with the lowest P value for clustering samples into three groups using the non-supervised algorithm k-means. Fisher’s linear discriminant analysis was then applied in an exhaustive search of trios of genes that could be used to build classifiers for class distinction. Different transcriptional levels of genes were identified in HCC of different etiologies and from different HCC samples. When comparing HBV-HCC vs HCV-HCC, HBV-HCC/HCV-HCC vs non-viral (NV)-HCC, HBC-HCC vs NV-HCC, and HCV-HCC vs NV-HCC of the 58 non-redundant differentially expressed genes, only 6 genes (IKBKβ, CREBBP, WNT10B, PRDX6, ITGAV, and IFNAR1) were found to be associated with hepatic carcinogenesis. By combining trios, classifiers could be generated, which correctly classified 100% of the samples. This expression profiling may provide a useful tool for research into the pathophysiology of HCC. A detailed understanding of how these distinct genes are involved in molecular pathways is of fundamental importance to the development of effective HCC chemoprevention and treatment