Does export intensity affect corporate leverage? Evidence from Portuguese SMEs

This paper examines the effect of export intensity on a firm's capital structure using a sample of 7,676 Portuguese SMEs. Results obtained from a system GMM estimation method show that the leverage ratio is negatively affected by export intensity. We document that firms with more growth opportunities have a higher leverage, while firms that have more profits, higher asset tangibility and face higher business risk have lower debt ratios. Our results also show that the implementation of governmental mechanisms that support export firms’ borrowing activities are critical in economies facing a financial crisisinfo:eu-repo/semantics/acceptedVersio

Changes associated with Na,K-ATPase in brain, kidney, heart and liver of the spontaneously diabetic Goto-Kakizaki rat

Alterations in Na,K-ATPase activity, in isoenzyme expression and/or number of units of the pump present in the plasma membrane have been associated with diabetes. These changes were described in different organs and tissues such as brain, heart, kidney, among others, and may result from altered insulin levels. However, the vast majority of studies were conducted in animal models of chemically induced diabetes, which are not consensual models for type 2 diabetes (T2D). The major goal of this work was to investigate putative modifications in Na,K-ATPase enzymatic activity or expression in brain, kidney, heart and liver in T2D. The Goto-Kakizaky rat (GK) strain was used as a model of spontaneously developed T2D, and Wistar rats as controls. Na,K-ATPase activity was assessed by the hydrolysis of ATP (Pi formed in the presence/absence of ouabain was measured using a colorimetric assay) and the isoenzymatic expression by Westernblot. A decrease in Na,K-ATPase activity in renal and cardiac tissues from GK comparatively to controls (55.7% and 77.5%, respectively) was observed. The pump activity was similar in liver and brain tissues. In renal tissue, expression of α1-Na,K-ATPase was similar between GK and controls but α2- was 2.3x higher and α3- was detected only in GK. Contrastingly a decreased expression of α1- (49.5%) and α2-isoforms (67.6%) was found in cardiac tissue. Despite similar Na,K-ATPase activity in liver and brain tissues, α1-isoform expression was decreased (33.9%) in the liver from GK while in the brain an increase of α1-isoform (~2x) together with a decrease of α2-isoform (14.0%) expressions were observed. It is unclear, except maybe for cardiac tissue where lower expression is potentially underlying the diminished pump activity in GK, whether the changes in isoenzyme expression is a key factor for differential Na,K-ATPase activity. Being responsive to complex regulation, other regulatory mechanisms may contribute to the impaired activity observed in kidney and heart. These results have uncover changes in Na,K-ATPase activity and/or enzymatic expression in GK brain, kidney, heart and liver that may contribute to the undesirable conditions associated with T2D. This work highlight the relevance of further investigation about Na,K-ATPase regulation and role in physiopathology of T2D

Effects of long-term exposure to colloidal gold nanorods on freshwater microalgae

Gold nanorods have shown to pose adverse effects to biota. Whether these effects may be potentiated through prolonged exposure has been rarely studied. Therefore, this work aimed at evaluating the effects of long-term exposure to sublethal levels of cetyltrimethylammonium bromide (CTAB) coated gold nanorods (Au-NR) on two freshwater microalgae: Chlorella vulgaris and Raphidocelis subcapitata. These algae were exposed to several concentrations of Au-NR for 72 h and, afterwards, to the corresponding EC5,72h, for growth, during 16 days. The sensitivity of the two algae to Au-NR was assessed at days 0, 4, 8, 12 and 16 (D0, D4, D8, D12 and D16, respectively) after a 72-h exposure to several concentrations of Au-NR. At the end of the assays, effects on yield and population growth rate were evaluated. Raphidocelis subcapitata was slightly more sensitive to Au-NR than C. vulgaris: EC50,72h,D0 for yield were 48.1 (35.3-60.9) and 70.5 (52.4-88.6) μg/L Au-NR, respectively while for population growth rate were above the highest tested concentrations (53 and 90 μg/L, respectively). For R. subcapitata the long-term exposure to Au-NR increased its sensitivity to this type of nanostructures. For C. vulgaris, a decrease on the effects caused by Au-NR occurred over time, with no significant effects being observed for yield or population growth rate at D12 and D16. The capping agent CTAB caused reductions in yield above 30% (D0) for both algae at the concentration matching the one at the highest Au-NR tested concentration. When exposed to CTAB, the highest inhibition values were 69% (D4) and 21.3% (D8) for R. subcapitata, and 64% (D12) and 21% (D16) to C. vulgaris, for yield and population growth rate, respectively. These results suggested long-term exposures should be included in ecological risk assessments since short-term standard toxicity may either under- or overestimate the risk posed by Au-NR.publishe

An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments

Rating the participation in Demand Response events with a contextual approach to improve accuracy of aggregated schedule

The flexibility provided by the demand side will be crucial to take a step forward to increase the penetration of renewable energy resources in the system. The proposed methodology provides the aggregator with information about the most reliable consumers, attributing a trustworthy rate that characterizes their performance on Demand Response (DR) events. The innovation relies on applying rates and evaluating the context in which the event is triggered and the factors that influence such rates. The authors find that context is essential to understand which participants are available for the event and achieve the reduction target successfully. Also, the proposed methodology focuses on the performance and the proper motivation for continuous participation, reducing the uncertainty of the response in DR events by giving higher economic compensation to the active consumers with better results. Distributed generation is also optimally managed by the aggregator. Findings prove the feasibility of the proposed methodology supporting the Aggregator in communities and smart cities management.This article is a result of the project RETINA (NORTE-01- 0145-FEDER-000062), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Cátia Silva is supported by national funds through Fundação para a Ciência e a Tecnologia (FCT) with PhD grant reference SFRH/BD/144200/2019. Pedro Faria is supported by FCT with grant CEECIND/01423/2021. The authors acknowledge the work facilities and equipment provided by GECAD research center (UIDB/00760/2020) to the project team.info:eu-repo/semantics/publishedVersio

Unnatural benz-X-azolyl asparagine derivatives as novel fluorescent amino acids : synthesis and photophysical characterization

A family of new asparagine derivatives bearing benzothiazole and benzimidazole units, functionalised with electron donor or acceptor groups, were synthesized in good to excellent yields. The photophysical characterization of these new heterocyclic amino acids was performed by UV-visible absorption and fluorescence emission studies and revealed that the compounds displayed remarkably high fluorescence quantum yields and Stokes’ shifts, making them good candidates for application as fluorescent probes by incorporation into peptidic frameworks.Fundação para a Ciência e a Tecnologia (FCT

Prediction of SLS parts properties using reprocessing powder

Purpose: Owing to the operating principle of powder bed fusion processes, selective laser sintering (SLS) requires effective management of the mixture ratio of processed material previously exposed to the high temperatures of processing with new virgin material. Therefore, this paper aims to fully understand the effect that the successive reprocessing has in the powder material and to evaluate its influence on the properties of SLS parts produced at different building orientations. Design/methodology/approach: Polyamide 12 material with 0%, 30% and 50% of virgin powder and parts produced from them were studied through five consecutive building cycles and their mass, mechanical, thermal and microstructural properties were evaluated. Then, the experimental data was used to validate a theoretical algorithm of prediction capable to define the minimum amount of virgin powder to be added on the processed material to produce parts without significant loss of properties. Findings: Material degradation during SLS influences the mass and mechanical properties of the parts, exhibiting an exponential decay property loss until 50% of the initial values. The theoretical algorithms of reprocessing proved the appropriateness to use a mixture of 30% of virgin with 70% of processed material for the most common purposes. Practical implications: This paper validates a methodology to define the minimum amount of virgin material capable to fulfil the operational specifications of SLS parts as a function of the number of building cycles, depending on the requirements of the final application. Originality/value: The use of theoretical models of prediction allows to describe the degradation effects of SLS materials during the sintering, ensuring the sustainable management of the processed powder and the economic viability of the process.The authors acknowledge the financial support given by FCT – Portuguese Foundation for Science and Technology through the reference project UID/CTM/50025/2019 and the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project n0 037902; Funding Reference: POCI-01-0247-FEDER-037902]

Avaliação microbiológica de enchidos de ovino e caprino

Os produtos de salsicharia portuguesa são, pelas suas características nutricionais c organoléticas, produtos alimentares da mais alta qualidade que interessa preservar. Recentes mudanças sociais, nomeadamente alteração dos hábitos dos consumidores, diversificação da ofet1a, crescimento da concorrência, aumento das expectativas e do nível de exigência dos consumidores, obrigaram ao investimento cm novas tecnologias c novos produtos estratégicos de mercado

Interplay between the salience and the default mode network in a social-cognitive task toward a close other

Social cognition relies on two main subsystems to construct the understanding of others, which are sustained by different social brain networks. One of these social networks is the default mode network (DMN) associated with the socio-cognitive subsystem (i.e., mentalizing), and the other is the salience network (SN) associated with the socio-affective route (i.e., empathy). The DMN and the SN are well-known resting state networks that seem to constitute a baseline for the performance of social tasks. We aimed to investigate both networks' functional connectivity (FC) pattern in the transition from resting state to social task performance. A sample of 38 participants involved in a monogamous romantic relationship completed a questionnaire of dyadic empathy and underwent an fMRI protocol that included a resting state acquisition followed by a task in which subjects watched emotional videos of their romantic partner and elaborated on their partner's (Other condition) or on their own experience (Self condition). Independent component and ROI-to-ROI correlation analysis were used to assess alterations in task-independent (Rest condition) and task-dependent (Self and Other conditions) FC. We found that the spatial FC maps of the DMN and SN evidenced the traditional regions associated with these networks in the three conditions. Anterior and posterior DMN regions exhibited increased FC during the social task performance compared to resting state. The Other condition revealed a more limited SN's connectivity in comparison to the Self and Rest conditions. The results revealed an interplay between the main nodes of the DMN and the core regions of the SN, particularly evident in the Self and Other conditions.info:eu-repo/semantics/publishedVersio