IFRS and Stock Returns: an Empirical Analysis in Brazil

In recent years, the convergence of accounting standards has been an issue that motivated new studies in the accounting field. It is expected that the convergence provides users, especially external users of accounting information, with comparable reports among different economies. Considering this scenario, this article was developed in order to compare the effect of accounting numbers on the stock market before and after the accounting convergence in Brazil. The sample of the study involved Brazilian listed companies at BM&FBOVESPA that had American Depository Receipts (levels II and III) at the New York Stock Exchange (NYSE). For data analysis, descriptive statistics and graphic analysis were employed in order to analyze the behavior of stock returns around the publication dates. The main results indicate that the stock market reacts to the accounting reports. Therefore, the accounting numbers contain relevant information for the decision making of investors in the stock market. Moreover, it is observed that after the accounting convergence, the stock returns of the companies seem to present lower volatility

Assessment of sediment contamination in an impacted estuary: differential effects and adaptations of sentinel organisms and implications for biomonitoring

Conferência realizada em Lisboa, de 6-9 November de 2013Estuarine pollution is reflected in the concentration of toxicants in sediments, depending on their geochemical properties, since sediments trap substances from the water column, either dissolved or bound to suspended matter. However, determining risk of sediment contaminants to biota has many constraints. For such reason, integrative approaches are keystone. Taking the Sado estuary (SW Portugal) as a case study, contrasted to a reference estuary (the Mira) within the same geographical location, the present study aimed at integrating sediment contamination with the effects and responses to pollutants in distinct benthic organisms with commercial and ecological value

The complexity of porphyrin-like pigments in a marine annelid sheds new light on haem metabolism in aquatic invertebrates

PTDC/MAR-BIO/0113/2014. UID/Multi/04378/2019. UID/QUI/50006/2019. SFRH/BD/120030/2016. SFRH/BD/109462/2015. IF/00265/2015.True green pigments in the animal kingdom are scarce and are almost invariably porphyrinoids. Endogenous porphyrins resulting from the breakdown of haem are usually known as “bile pigments”. The pigmentation of intertidal Polychaeta has long gained attention due to its variety and vivid patterning that often seems incompatible with camouflage, as it occurs with Eulalia viridis, one of the few truly green Polychaeta. The present study combined UV and bright-field microscopy with HPLC to address the presence and distribution of pigments in several organs. The results showed two major types of porphyrin-like pigments, yellowish and greenish in colour, that are chiefly stored as intraplasmatic granules. Whereas the proboscis holds yellow pigments, the skin harbours both types in highly specialised cells. In their turn, oocytes and intestine have mostly green pigments. Despite some inter-individual variation, the pigments tend to be stable after prolonged storage at −20 °C, which has important implications for future studies. The results show that, in a foraging predator of the intertidal where melanins are circumscribed to lining the nervous system, porphyrinoid pigments have a key role in protection against UV light, in sensing and even as chemical defence against foulants and predators, which represents a remarkable adaptive feature.publishersversionpublishe

A Soft Computing Approach to Acute Coronary Syndrome

Acute Coronary Syndrome (ACS) is transversal to a broad and heterogeneous set of human beings, and assumed as a serious diagnosis and risk stratification problem. Although one may be faced with or had at his disposition different tools as biomarkers for the diagnosis and prognosis of ACS, they have to be previously evaluated and validated in different scenarios and patient cohorts. Besides ensuring that a diagnosis is correct, attention should also be directed to ensure that therapies are either correctly or safely applied. Indeed, this work will focus on the development of a diagnosis decision support system in terms of its knowledge representation and reasoning mechanisms, given here in terms of a formal framework based on Logic Programming, complemented with a problem solving methodology to computing anchored on Artificial Neural Networks. On the one hand it caters for the evaluation of ACS predisposing risk and the respective Degree-of-Confidence that one has on such a happening. On the other hand it may be seen as a major development on the Multi-Value Logics to understand things and ones behavior. Undeniably, the proposed model allows for an improvement of the diagnosis process, classifying properly the patients that presented the pathology (sensitivity ranging from 89.7% to 90.9%) as well as classifying the absence of ACS (specificity ranging from 88.4% to 90.2%)

An Integrated Soft Computing Approach to Hughes Syndrome Risk Assessment

The AntiPhospholipid Syndrome (APS) is an acquired autoimmune disorder induced by high levels of antiphospholipid antibodies that cause arterial and veins thrombosis, as well as pregnancy-related complications and morbidity, as clinical manifestations. This autoimmune hypercoagulable state, usually known as Hughes syndrome, has severe consequences for the patients, being one of the main causes of thrombotic disorders and death. Therefore, it is required to be preventive; being aware of how probable is to have that kind of syndrome. Despite the updated of antiphospholipid syndrome classification, the diagnosis remains difficult to establish. Additional research on clinically relevant antibodies and standardization of their quantification are required in order to improve the antiphospholipid syndrome risk assessment. Thus, this work will focus on the development of a diagnosis decision support system in terms of a formal agenda built on a Logic Programming approach to knowledge representation and reasoning, complemented with a computational framework based on Artificial Neural Networks. The proposed model allows for improving the diagnosis, classifying properly the patients that really presented this pathology (sensitivity higher than 85%), as well as classifying the absence of APS (specificity close to 95%)

Composites based on PDMS and graphite flakes for thermoelectric sensing applications

[Excerpt] Thermoelectric (TE) devices are utilized for thermal energy harvesting, local cooling or heating, and temperature sensing. They have no mechanical structures, can be made flexible and present long operating lifetimes, making them useful for the Internet of Things (IoT) and wearable electronics.[...]This work was financed by national funds from FCT-Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication–i3N, and by projects PTDC/NAN-MAT/32558/2017 and PTDC/CTM-PAM/4241/2020. E.V. thanks the FCT Fundação para a Ciência e a Tecnologia, I.P., under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020. J.F. thanks the support from FCTFundação para a Ciência e a Tecnologia, I.P. through the PhD scholarship SFRH/BD/121679/2016 (Joana Figueira). This work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Grant Agreements Nos: 640598 (ERC-2014-STG NEW-FUN), 952169 (SYNERGY, H2020-WIDESPREAD-2020-5, CSA), and 101008701 (EMERGE, H2020-INFRAIA2020-1)

A case-based reasoning view of thrombophilia risk

Thrombophilia stands for a genetic or an acquired tendency to hypercoagulable states that increase the risk of venous and arterial thromboses. Indeed, venous thromboembolism is often a chronic illness, mainly in deep venous thrombosis and pulmonary embolism, requiring lifelong prevention strategies. Therefore, it is crucial to identify the cause of the disease, the most appropriate treatment, the length of treatment or prevent a thrombotic recurrence. Thus, this work will focus on the development of a diagnosis decision support system in terms of a formal agenda built on a logic programming approach to knowledge representation and reasoning, complemented with a case-based approach to computing. The proposed model has been quite accurate in the assessment of thrombophilia predisposition risk, since the overall accuracy is higher than 90% and sensitivity ranging in the interval [86.5%, 88.1%]. The main strength of the proposed solution is the ability to deal explicitly with incomplete, unknown, or even self-contradictory information

Paper-based platform with an in situ molecularly imprinted polymer for ß-amyloid

Alzheimers disease (AD) is one of the most common forms of dementia affecting millions of people worldwide. Currently, an easy and effective form of diagnosis is missing, which significantly hinders a possible improvement of the patients quality of life. In this context, biosensors emerge as a future solution, opening the doors for preventive medicine and allowing the premature diagnosis of numerous pathologies. This work presents a pioneering biosensor that combines a bottom-up design approach using paper as a platform for the electrochemical recognition of peptide amyloid -42 (A-42), a biomarker for AD present in blood, associated with visible differences in the brain tissue and responsible for the formation of senile plaques. The sensor layer relies on a molecularly imprinted polymer as a biorecognition element, created on the carbon ink electrodes surface by electropolymerizing a mixture of the target analyte (A-42) and a monomer (O-phenylenediamine) at neutral pH 7.2. Next, the template molecule was removed from the polymeric network by enzymatic and acidic treatments. The vacant sites so obtained preserved the shape of the imprinted protein and were able to rebind the target analyte. Morphological and chemical analyses were performed in order to control the surface modification of the materials. The analytical performance of the biosensor was evaluated by an electroanalytical technique, namely, square wave voltammetry. For this purpose, the analytical response of the biosensor was tested with standard solutions ranging from 0.1 ng/mL to 1 g/mL of A-42. The linear response of the biosensor went down to 0.1 ng/mL. Overall, the developed biosensor offered numerous benefits, such as simplicity, low cost, reproducibility, fast response, and repeatability less than 10%. All together, these features may have a strong impact in the early detection of AD.The authors acknowledge funding from project PTDC/AAGTEC/5400/2014, POCI-01-0145-FEDER-016637, POCI-01-0145-FEDER-007688, and UID/CTM/50025/2019 funded by European funds through FEDER (European Funding or Regional Development) via COMPETE2020 - POCI (operational program for internationalization and competitively) by national funding through the National Foundation for Science and Technology, I.P. (FCT-MCTES). Additionally, they are grateful to the project IBEROS, Instituto de Bioingenieria en Red para el Envejecimiento Saludable, POCTEP/0245-BEROS-1-E, PROGRAMA INTERREG 2014-2020 funded through FEDER within the cooperation region of Galiza/Spain and North of Portugal. A.C.M. and F.T.C.M. gratefully acknowledges FCT-MCTES for the financial support (PhD grant reference SFRH/BD/115173/2016 intituled “Nanobiosensing platform based on MIP-SERS for breast cancer exosome characterization and detection” and Post-Doc grant reference SFRH/BPD/97891/2013 intituled “Biomedical devices for easier and quicker screening procedures of the Alzheimer’s). This work is part of the Master Thesis in Micro and Nanotechnology Engineering defended by Marta V. Pereira. at FCT NOVA titled “Fabrication of 3D electrodes for biosensor applications” in December 2018.info:eu-repo/semantics/publishedVersio

Different patterns of evolution for duplicated DNA repair genes in bacteria of the Xanthomonadales group

BACKGROUND: DNA repair genes encode proteins that protect organisms against genetic damage generated by environmental agents and by-products of cell metabolism. The importance of these genes in life maintenance is supported by their high conservation, and the presence of duplications of such genes may be easily traced, especially in prokaryotic genomes. RESULTS: The genome sequences of two Xanthomonas species were used as the basis for phylogenetic analyses of genes related to DNA repair that were found duplicated. Although 16S rRNA phylogenetic analyses confirm their classification at the basis of the gamma proteobacteria subdivision, differences were found in the origin of the various genes investigated. Except for lexA, detected as a recent duplication, most of the genes in more than one copy are represented by two highly divergent orthologs. Basically, one of such duplications is frequently positioned close to other gamma proteobacteria, but the second is often positioned close to unrelated bacteria. These orthologs may have occurred from old duplication events, followed by extensive gene loss, or were originated from lateral gene transfer (LGT), as is the case of the uvrD homolog. CONCLUSIONS: Duplications of DNA repair related genes may result in redundancy and also improve the organisms' responses to environmental challenges. Most of such duplications, in Xanthomonas, seem to have arisen from old events and possibly enlarge both functional and evolutionary genome potentiality