Linking appraisal to behavioral flexibility in animals: implications for stress research

In fluctuating environments, organisms require mechanisms enabling the rapid expression of context-dependent behaviors. Here, we approach behavioral flexibility from a perspective rooted in appraisal theory, aiming to provide a better understanding on how animals adjust their internal state to environmental context. Appraisal has been defined as a multi-component and interactive process between the individual and the environment, in which the individual must evaluate the significance of a stimulus to generate an adaptive response. Within this framework, we review and reframe the existing evidence for the appraisal components in animal literature, in an attempt to reveal the common ground of appraisal mechanisms between species. Furthermore, cognitive biases may occur in the appraisal of ambiguous stimuli. These biases may be interpreted either as states open to environmental modulation or as long-lasting phenotypic traits. Finally, we discuss the implications of cognitive bias for stress research.FCT Ph.D. fellowships: (SFRH/BD/79087/2011, SFRH/BD/68528/2010), FCT strategic grant: (PEst-OE/MAR/UI0331/2011)

Adverse reactions and dietary supplements

Over the last years, the use of dietary supplements has increased substantially. Although these products are considered as safe and can be beneficial, there are risks associated with some. Manufacturers are not required to demonstrate their safety and efficacy, so it is essential that consumers have good knowledge about dietary supplements. The attribution of injury to a specific supplement can be challenging, especially because of the multiple ingredients, the variability in quality and content, as well as the vast underreporting of adverse reactions.info:eu-repo/semantics/publishedVersio

Insulin in Central Nervous System: More than Just a Peripheral Hormone

Insulin signaling in central nervous system (CNS) has emerged as a novel field of research since decreased brain insulin levels and/or signaling were associated to impaired learning, memory, and age-related neurodegenerative diseases. Thus, besides its well-known role in longevity, insulin may constitute a promising therapy against diabetes- and age-related neurodegenerative disorders. More interestingly, insulin has been also faced as the potential missing link between diabetes and aging in CNS, with Alzheimer's disease (AD) considered as the “brain-type diabetes.” In fact, brain insulin has been shown to regulate both peripheral and central glucose metabolism, neurotransmission, learning, and memory and to be neuroprotective. And a future challenge will be to unravel the complex interactions between aging and diabetes, which, we believe, will allow the development of efficient preventive and therapeutic strategies to overcome age-related diseases and to prolong human “healthy” longevity. Herewith, we aim to integrate the metabolic, neuromodulatory, and neuroprotective roles of insulin in two age-related pathologies: diabetes and AD, both in terms of intracellular signaling and potential therapeutic approach

Mechanisms of social buffering of fear in zebrafish

The supplementary materials such the videos, are not present in the deposit due to incompatibilty of the extension of the files with the repository.Some humans thrive whereas others resign when exposed to threatening situations throughout life. Social support has been identified as an important modulator of these discrepancies in human behaviour, and other social animals also exhibit phenomena in which individuals recover better from aversive events when conspecifics are present - aka social buffering. Here we studied social buffering in zebrafish, by exposing focal fish to an aversive stimulus (alarm substance - AS) either in the absence or presence of conspecific cues. When exposed to AS in the presence of both olfactory (shoal water) and visual (sight of shoal) conspecific cues, focal fish exhibited a lower fear response than when tested alone, demonstrating social buffering in zebrafish. When separately testing each cue's effectiveness, we verified that the visual cue was more effective than the olfactory in reducing freezing in a persistent threat scenario. Finally, we verified that social buffering was independent of shoal size and coincided with a distinct pattern of co-activation of brain regions known to be involved in mammalian social buffering. Thus, this study suggests a shared evolutionary origin for social buffering in vertebrates, bringing new evidence on the behavioural, sensory and neural mechanisms underlying this phenomenon.info:eu-repo/semantics/publishedVersio

Histone Deacetylase Inhibitors Protect Against Pyruvate Dehydrogenase Dysfunction in Huntington's Disease

Transcriptional deregulation and changes in mitochondrial bioenergetics, including pyruvate dehydrogenase (PDH) dysfunction, have been described in Huntington's disease (HD). We showed previously that the histone deacetylase inhibitors (HDACIs) trichostatin A and sodium butyrate (SB) ameliorate mitochondrial function in cells expressing mutant huntingtin. In this work, we investigated the effect of HDACIs on the regulation of PDH activity in striatal cells derived from HD knock-in mice and YAC128 mice. Mutant cells exhibited decreased PDH activity and increased PDH E1alpha phosphorylation/inactivation, accompanied by enhanced protein levels of PDH kinases 1 and 3 (PDK1 and PDK3). Exposure to dichloroacetate, an inhibitor of PDKs, increased mitochondrial respiration and decreased production of reactive oxygen species in mutant cells, emphasizing PDH as an interesting therapeutic target in HD. Treatment with SB and sodium phenylbutyrate, another HDACI, recovered cell viability and overall mitochondrial metabolism in mutant cells. Exposure to SB also suppressed hypoxia-inducible factor-1 (HIF-1α) stabilization and decreased the transcription of the two most abundant PDK isoforms, PDK2 and PDK3, culminating in increased PDH activation in mutant cells. Concordantly, PDK3 knockdown improved mitochondrial function, emphasizing the role of PDK3 inactivation on the positive effects achieved by SB treatment. YAC128 mouse brain presented higher mRNA levels of PDK1-3 and PDH phosphorylation and decreased energy levels that were significantly ameliorated after SB treatment. Furthermore, enhanced motor learning and coordination were observed in SB-treated YAC128 mice. These results suggest that HDACIs, particularly SB, promote the activity of PDH in the HD brain, helping to counteract HD-related deficits in mitochondrial bioenergetics and motor function.SIGNIFICANCE STATEMENT The present work provides a better understanding of mitochondrial dysfunction in Huntington's disease (HD) by showing that the pyruvate dehydrogenase (PDH) complex is a promising therapeutic target. In particular, the histone deacetylase inhibitor sodium butyrate (SB) may indirectly (through reduced hypoxia-inducible factor 1 alpha stabilization) decrease the expression of the most abundant PDH kinase isoforms (e.g., PDK3), ameliorating PDH activity and mitochondrial metabolism and further affecting motor behavior in HD mice, thus constituting a promising agent for HD neuroprotective treatment.FCT, Santa Casa da Misericórdia de Lisboa (SCML), Fundação Luso-Americana para o Desenvolvimento (FLAD) Life Scienc

Livro de atas do XVI Congresso da Associação Portuguesa de Investigação Operacional

Fundação para a Ciência e Tecnologia - FC

Two-dimensional open microfluidic devices by tuning the wettability on patterned superhydrophobic polymeric surface

We present a simple and economical method to produce a potential open microfluidic polymeric device. Biomimetic superhydrophobic surfaces were prepared on polystyrene using a phase separation methodology. Patterned two-dimensional channels were imprinted on the superhydrophobic substrates by exposing the surface to plasma or UV–ozone radiation. The wettability of the channels could be precisely controlled between the superhydrophobic and superhydrophilic states by changing the exposure time. The ability of superhydrophilic paths to drive liquid flows in a horizontal position was found to be significantly higher than for the case of hydrophilic paths patterned onto smooth surfaces.(undefined

Influence of Au on antibacterial activity of Ag-TiCN coatings

The increasing demand for sustainable products requires the development of new knowledge-based materials with advanced properties. These products are then expected to: last longer, have a better performance, be safe, and be more efficient. These requirements, gain particular importance when dealing with applications involving the human body: the so-called biomaterials. Thus, the main aim of these investigations is to contribute to the development of new biomaterials that are able to prevent biofilm formation, since those complex microbial communities are responsible for the undesired reactions such as inflammation and infection, and consequently medical devices rejection. This work reports the development of Ag-TiCN coatings doped with gold. One series of samples was prepared by DC reactive magnetron sputtering using two targets, Ti and Ti+Ag, in an Ar + C2H2 + N2 atmosphere. Silver pellets were placed in the erosion area of Ti target in order to obtain a silver content up to 10 at. %. A second series of samples was deposited with the same conditions but with the Ti target doped with one Au piece. Extended physical, chemical and structural characterization such as the study of composition, grain size and texture phase evolution, phase composition, film surface topography and morphology, will be achieved resorting to surface analysis techniques, such as, Electron Probe Microanalysis (EPMA), X-ray diffraction (XRD), Atomic Force Microscopy (AFM), scanning electron microscopy (SEM-EDS). The galvanic couple formed between gold and silver, accelerates silver ion release and should provide more pronounced antibacterial activity. Staphylococcus epidermidis was selected to study coatings' antibacterial activity, and fibroblasts were used to test the cytotoxicity. Bacteria adhesion and biofilm formation on coatings were assessed by crystal violet staining, which quantifies total amount of biomass. Animal cell (fibroblasts) death was determined by MTS assay

Hotel customer segmentation and sentiment analysis through online reviews: An analysis of selected European markets [Segmentação de clientes hoteleiros e análise de sentimento através de avaliações online: uma análise de mercados europeus selecionados]

Oliveira, A. S., Renda, A. I., Correia, M. B., & António, N. (2022). Hotel customer segmentation and sentiment analysis through online reviews: An analysis of selected European markets [Segmentação de clientes hoteleiros e análise de sentimento através de avaliações online: uma análise de mercados europeus selecionados]. Tourism & Management Studies, 18(1), 29-40. https://doi.org/10.18089/tms.2022.180----------------------------------------------This paper is financed by National Funds provided by FCTFoundation for Science and Technology through project UIDB/04470/2020This study aims to verify how distinct markets evaluate hotels in the Algarve through the analysis of online reviews, in order to identify if satisfaction and dissatisfaction attributes are similar among some of the main markets of overnight stay tourists in the region. Online reviews of hotels in the Algarve, written in English, French as well as Portuguese and posted on Tripadvisor by British, French and Portuguese residents from January 2019 to December 2019 are analysed. After the analysis of 8,596 online textual reviews, the results demonstrated that not only satisfaction and dissatisfaction rates towards hotel attributes differ according to the language, but also that customers from different countries place dissimilar emphasis on hotel attributes. Besides extending the current research on the use of online reviews, the findings of this study also assist hoteliers to identify improvement opportunities. Although many studies on marketing segmentation through data mining have been conducted, this paper analyses the customer satisfaction of relevant tourist markets and suggests up-to-date practical implications for hoteliers. --------------------------------------------------------------------------------------- Este estudo tem como objetivo verificar como mercados distintos avaliam hotéis no Algarve através da análise de comentários online, a fim de identificar se os atributos de satisfação e insatisfação são semelhantes entre alguns dos principais mercados turísticos da região. São analisadas avaliações online de hotéis no Algarve, escritas em inglês, francês e português e publicadas no Tripadvisor por residentes britânicos, franceses e portugueses de janeiro de 2019 a dezembro de 2019. Após a análise de 8.596 avaliações textuais online, os resultados demonstraram que não apenas as taxas de satisfação e insatisfação em relação aos atributos hoteleiros diferem de acordo com a língua, mas também que clientes de diferentes países colocam ênfase diferente nos atributos do hotel. Além de ampliar a pesquisa atual sobre o uso de revisões online, os resultados deste estudo também auxiliam os hoteleiros a identificar oportunidades de melhoria. Embora muitos estudos sobre segmentação de marketing por meio da mineração de dados tenham sido realizados, este artigo analisa a satisfação dos clientes dos mercados turísticos relevantes e sugere implicações práticas atualizadas para os hoteleirospublishersversionpublishe

Influence of albumin on the tribological behavior of Ag-Ti (C, N) thin films for orthopedic implants

With the increase of elderly population and the health problems arising nowadays, such as cancer, knee and hip joint prostheses are widely used worldwide. It is estimated that 20% of hip replacement surgeries simply fail after 5 years, due to wear loosening, instability and infection. In this paper it is reported the study of advanced materials with the ability to overcome some of these drawbacks. The development of ceramic coatings, based on carbonitrides of transition metals, such as TiCN, doped with silver, Ag, may represent an effective solution. Thin films of Ag-TiCN were produced by dc reactive magnetron sputtering with silver contents ranging from 4 to 8 at. %. The physical, chemical, structural, morphological/topographical, mechanical and tribological properties were evaluated. The tribological tests were performed in a unidirectional wear simulator, pin on disc, being the antagonists of a ceramic Al2O3 ball, and using simulate body fluids as lubricant. Hank’s Balanced Salt Solution (HBSS) and bovine serum albumin (BSA) in HBSS were chosen, in order to evaluate the lubrication ability of the solution containing the protein, albumin. The results revealed that the coatings with Ag content ranging from 4 to 8 at. %, were the most promising, as the tribological properties were superior to the results reported by other authors, which also developed Ag-TiCN coatings containing similar Ag contents and using similar test conditions. The presence of albumin lead to a lower wear in all the test conditions, and this enhancement was higher in the hydrophobic surfaces.This research is sponsored by FEDER funds through the program COMPETE - Programa Operacional Factores de Competitividade and by National funds through FCT - Fundacao para a Ciencia e a Tecnologia, in the framework of the Strategic Projects PEST-C/FIS/UI607/2011, and PEst-C/EME/UI0285/2011 and under the project, PTDC/CTM/102853/2008