Task switching ability is compromised after cross-hemispheric tDCS over the parietal cortex

Background/Aims: One of the components of working memory is the ability to respond to unexpected demands and rapidly shifting attention between tasks. Previous studies have used transcranial direct current stimulation (tDCS) in order to modulate task and set shifting ability over the prefrontal cortex. However, set shifting/task switching ability requires a left-lateralized fronto-parietal network. In this study, we aimed to assess if delivering active cross-hemispheric tDCS over the parietal cortex - right anodal/-left-cathodal (pRA-LC) and right cathodal/-left anodal (pRC-LA), as compared to sham tDCS, is able to modulate task switching ability in healthy volunteers. Methods: A total of 17 college students who volunteered (age: 21.65 ± 4.42, 14 females) participated in this pilot study in which the effects of three different single session tDCS conditions over the parietal cortex on task switching ability were assessed. Results: There were significant differences in terms of switch costs F (2,28) = 4,01, p < .05 dependent on stimulation. Bonferroni pairwise comparisons showed that the Response Time (RT) of the Switch Cost increased significantly (M = 102.84, SD = 18.24) for the pRA-LC condition, when compared with the sham condition (M = 49.44, SD = 17.84) (p = .03, d=2.96) Conclusions: The results of this study highlight the importance of studying the role of the parietal cortex in task switching ability. An activity shift towards the right parietal hemisphere (i.e., pRA-LC) impaired task switching performance, which is consistent with the role of the left parietal cortex on endogenous preparation and adjustment of goal directed behaviors. Future studies should focus on exploring the electrophysiological and neuroimaging correlates associated with the tDCS effects over the parietal, as well as exploring the usefulness of multi-site stimulation.OFG and SC were supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653) and along with JL were also funded through the grants: PTDC/PSIESP/30280/2017 and PTDC/PSI-ESP/29701/2017, SC was also funded by the individual grant IF/00091/2015

Contribuição para o dimensionamento de condomínios energéticos

Mestrado em Engenharia Eletrotécnica-Energia e Automação IndustrialAo longo dos últimos anos, a produção distribuída de eletricidade teve um rápido crescimento, devido aos mecanismos de incentivo que foram implementados principalmente nos países que integram a União Europeia. Perante este cenário tem-se assistido a um aumento da ligação de pequenas unidades de produção distribuída (microgeração) à rede de baixa tensão. Este facto tem levado à investigação sobre formas de integrar dos sistemas de microgeração nas redes baixa tensão. Neste âmbito, um dos conceitos que têm vindo a ser desenvolvido são as microredes elétricas. No entanto, novos conceitos como os condomínios energéticos poderão também ser englobados no seio do sistema elétrico. A presente dissertação procura contribuir para a definição do conceito de condomínio energético, visto como uma expansão natural das microredes e, consequentemente, na definição de modelos que podem ser aplicados para dimensionamento destas entidades. Os modelos desenvolvidos procuram potenciar os benefícios mais relevantes da produção distribuída, tendo em consideração os seguintes fatores: i) dimensionamento de uma rede elétrica totalmente (condomínio autónomo) ou parcialmente (condomínio com consumo líquido zero) autónoma; ii) conjugação de redes elétricas e de calor; iii) localização da produção distribuída no interior da rede visando a redução de perdas e a não degradação dos níveis de tensão; e iv) dimensionamento otimizado da rede de distribuição de eletricidade integrada no condomínio. A metodologia desenvolvida é aplicada a casos de estudos baseados em redes reais. Os resultados obtidos permitem retirar conclusões que caracterizam os potenciais benefícios e custos que resultam da implementação do conceito de condomínio energético. A dissertação é finalizada com a avaliação da capacidade dos condomínios energéticos prestarem serviços à rede a montante. Esta avaliação teve em consideração as características destas estruturas, nomeadamente a possibilidade de alterar a carga e a produção internas.ABSTRACT: Over the past few years, distributed generation of electricity had a rapid growth due to incentive mechanisms that have been implemented mainly in the countries of the European Union. Considering this concept, we have observed an increase of the connection of small units of distributed production (microgeneration) to the low voltage network. This has led to the research on ways to integrate the microgeneration systems in low voltage network. In this context, one of the concepts that have been developed is the electrical microgrids. However, new concepts such as energetic condominiums may also be included within the electrical system. This work aims to contribute to the definition of energetic condominiums, seen as a natural expansion of microgrids and consequently as a definition of models that can be applied to the measurement of these entities. The developed models intend to maximize the most relevant benefits of the distributed generation by taking into account the following factors: i) Total dimensioning of an electrical grid (autonomous condominium ) or partially autonomous (with zero net energy); ii) combination of heat and electrical networks; iii) location of distributed generation within the network in order to reduce loss and no degradation of voltage levels; and iv) optimized dimensioning of the network distribution of electricity integrated in the condo. The methodology applied is based upon real networks study cases. The results obtained allow us to draw conclusions which characterize the potential benefits and costs resulting from the implementation of the concept of energetic condominium. The dissertation concludes with an evaluation of the ability of condominiums to provide energy services to the upstream network. This evaluation has taken into account the characteristics of these structures, mainly the possibility of changing the amount of charge and internal production

Speed of Processing (SoP) Training Plus α-tACS in People With Mild Cognitive Impairment: A Double Blind, Parallel, Placebo Controlled Trial Study Protocol

Several cognitive training programs, alone or in combination with non-invasive brain stimulation have been tested in order to ameliorate age-related cognitive impairments, such as the ones found in Mild Cognitive Impairment (MCI). However, the effects of Cognitive Training (CT)—combined or not—with several forms of non-invasive brain stimulation have been modest at most. We aim to assess if Speed of Processing (SoP) training combined with alpha transcranial alternating current stimulation (α-tACS) is able to increase speed of processing as assessed by the Useful Field of View (UFOV), when comparing to SoP training or active α-tACS alone. Moreover, we want to assess if those changes in speed of processing transfer to other cognitive domains, such as memory, language and executive functioning by using the NIH EXAMINER. We also want to test the mechanisms underlying these interventions, namely brain connectivity and coherence as assessed by electroencephalography (EEG). To that purpose, our proposal is to enroll 327 elders diagnosed with MCI in a double-blinded, parallel randomized clinical trial assessing the effects of combining SoP with alpha endogenous tACS (either active or sham) in people with MCI. Participants will perform an intervention that will last for 15 sessions. For the first 3 weeks, participants will receive nine sessions of the intervention, and then will receive two sessions per week (i.e., booster) for the following 3 weeks. They will then be assessed at 1, 3, and 6 months after the intervention has ended. This will allow us to detect the immediate, and long-term effects of the interventions, as well as to probe the mechanisms underlying its effects.Clinical Trial Registration:Clinicaltrials.gov, Identifier: NCT05198726

A superhydrophilic biomimicked ceramic-reinforced-polymer nanocomposite for enhanced slip resistance and adhesion

Slips and Falls (SFs) were not considered a major source of lethal injuries until recently. Two-third of SF accidents happen due to the presence of ice on the surface around countries with snowfall making it second prominent reason of fatal injuries. Nearly 70,000 serious SFs happen in Finland and Sweden every year, and about 17,000 people lose their lives in USA (annual 1 million cases). Approximately 83% of people in Russia and thousands of people fall during winter in the UK and die as per HSE-UK. WHO-2021 recorded 37.3 million SFs cases demanding medical attention including millions requiring intensive care which resulted into permanent injuries, trauma, loss of limbs, loss of jobs, and burden on insurance and healthcare. Huge monetary deficits were recorded in Finland as €2.4 billion, €280 million in Sweden, £42 million in the UK occurred due to SFs. USA and Canada spend more than $55 billions annually on healthcare due to SFs. An effective anti-slipping shoe-sole can prevent and avoid these mishaps. Shoe-sole design modifications like tread patterns, crampons, studs, spikes etc. or material variations to improve friction between the sole-ice interface have been utilised. Though crampons/spikes/studs are effective, they are unsuitable for indoor usages, physically challenged and children. Whereas material-based solutions lose their effectiveness due to quick wear or in the presence of wet ice with quasi-liquid layer. We introduce nano-powder based ceramic reinforced composite patterned with Laser Surface Texturing (LST). Patterns are nature-inspired and are adapted from gecko/frog toepad structures that offer excellent friction on dry and wet surfaces. This innovation is a combination of material and design modifications and is not limited to anti-slipping shoe-soles. E-skin, drug delivery, wound healing, and electronic sensor patches face severed adhesion due to handling of body fluid and perspiration at the interface. Silicone Rubber polymer and proven anti-bacterial nano powders of zirconia and/or titania were mixed, vulcanised and textured to produce microfibrillar structure. This composite is highly wettable, wear-resistant, and adhering to wet and dry surfaces by creating capillary bridges. The capillary bridges provide mechanical interlocking on icy surfaces and serve as suction locations for patches to absorb and evaporate the bodily exudations out. We used five zirconia compositions (1, 3, 5, 7, and 9% by weight) producing composite with three sizes of capillary cavities to obtain best capillary effect. The findings of the study include average Shore-A hardness (32 to 40), morphology and topography, parametric optimisation of LST parameters, and wettability analysis. Obtained nano composite has excellent physicochemical superhydrophilicity (absorption of water droplet within 50 milliseconds after contact) with high static and kinetic friction coefficients of 2.5 and 1.62, respectively on wet ice suitable for mentioned applications

Sistema de detecção de posição

O trabalho a desenvolver nesta Dissertação enquadra-se no âmbito do projecto FIREND®, no qual se pretende projectar uma munição que permita a colaboração da artilharia no combate a incêndios florestais. Essa munição deve libertar uma substância, que possibilite o retardamento da expansão do fogo ou mesmo a sua extinção. A presente Dissertação descreve um sistema de altimetria que permite o accionamento da munição antes do seu embate com o solo. O sistema de altimetria utiliza um laser e o método de medida de distâncias conhecido por telemetria por impulsos. Na telemetria por impulsos o sistema tem basicamente um emissor laser e um foto-receptor. A distância é calculada através da medida do tempo de voo de um impulso emitido pelo laser, ou seja, do tempo que decorre desde a emissão do impulso até à sua chegada ao foto-receptor após ser reflectido pelo alvo. A colocação do sistema de altimetria na munição impõe um conjunto de restrições ao sistema. Assim as suas dimensões devem ser reduzidas, não necessita de uma precisão de medida muito elevada (~1m), deve ter um custo baixo e deve ser capaz de suportar os valores da aceleração inicial aquando do lançamento da munição.This research is part of the project FIREND®, which aims to design ammunition that allows the artillery collaborate in forest fires fighting. This ammunition should release a substance that allows delaying the expansion of fire or even the extinction. This master thesis describes an altimetry system that allows the actuation of the ammunition before the impact with the ground. The altimetry system uses a laser measurement method known by pulsed telemetry. In the pulse telemetry system is basically a laser emitter and a photo-receiver. The distance is calculated by measuring the time of flight of a pulse emitted by the laser, ie, the time from the emission of the pulse until it reaches the photo-receiver after being reflected by the target. The ammunition imposes some conditions on the project of the altimetry system namely on the physical dimensions of the system, on the precision of the measures (~1m) and on the cost of the system. Additionally the system has to support the initial acceleration when the ammunition is fired

Comparative study of the tarnishing resistance of several coloured base gold alloys

The stability of coloured gold alloys may be dependent on the environment that involves them. This paper is concerned with the effect of an artificial sweat solution in the stability of several gold base alloys with different colours. The changes in the samples physical properties, colour, brightness, and reflectance were measured for several periods of immersion. Two types of alloys (purple and blue coloured alloys) showed to be sensitive to the artificial sweat solution. The other tested alloys have a high resistance to tarnishing comparable with the results obtained for pure gold

Hydrothermal ageing behavior of bioinspired material with piezoelectric functions for implant applications

Implant-bone fixation loss can occur 10-15 years after surgery. This is related to bone resorption and consecutive biofilm formation in the generated gap, which could lead to tissues inflammation and implant loss [1]. Current solutions are focused on primary osseointegration for implant early survival rate. In long term, they lose effectiveness due to implant foreign body reaction once bone metabolism is challenged by a non-part of the body. Bone is composed of piezoelectric materials with production of biological electricity due to collagen deformation and displacement of the local electric field [2]. Barium titanate is a lead-free piezoelectric bioceramic without toxicological risk and absence of foreign body reactions that can mimic natural bone piezoelectricity and inhibit bacterial adhesion [3]. The focus of this work is design, produce, and characterize a smart, bio-inspired, and multi-functional composite material to improve implant long-term bone regeneration and antibacterial effect. In this sense, a composite with BaTiO3 particles and bioinert ZrO2 was produced. 5%BaTiO3-ZrO2 composites were mixed in isopropanol alcohol and ultrasonicated for total dispersion, followed by press (200MPa) and sintering technic (1300-1500ºC). The different samples were characterized with SEM (Fig1.(a)), that present two distinct phases, XRD analysis, and subjected to hydrothermal ageing (Fig1.(b)), to evaluate the stability of the tetragonal zirconia phase. After 5h of accelerated ageing (≈10 years), monoclinic phase is more evident with the sintering temperature increment, but always lower than 25%, staying in according with ISO 13356:200, promising to be promising a potential replacement material for implant applications.This work was supported by FCT national funds under the national support to R&D units grant, through the reference project UIDB/04436/2020, UIDP/04436/2020, FunImp POCI-01-0145-FEDER-030498 and through the grant 2021.09001.BD

Morphometric and connectivity white matter abnormalities in Obsessive Compulsive Disorder

Two psychological mechanisms seem to be associated with the obsessive-compulsive cycle: (1) an emotional mechanism characterized by intense emotional arousal associated with intrusive thoughts of impending danger; (2) a cognitive mechanism exemplified by difficulties with inhibitory control. Several studies found more extensive cognitive deficits in Obsessive Compulsive Disorder (OCD) beyond problems of inhibitory control and emotional regulation, namely: visual-spatial processing and memory. Thus, there is now extensive research showing that alterations of these psychological mechanisms in OCD (i.e., inhibitory control, emotional regulation, working memory, and visual spatial processing) are associated with morphological gray matter alterations in widespread brain regions. More recently, researchers have started looking at white matter abnormalities in OCD. In this article we review the research looking at white matter morphometric and structural connectivity alterations in OCD. Altogether, while some contradictory findings are still present, there is now evidence for widespread white matter morphometric and connectivity abnormalities affecting major white matter tracts (superior longitudinal fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, cingulum bundle, semioval center, internal capsule, different regions of the corpus callosum, thalamic radiation, uncinate fasciculus and optic radiation) as well as white matter in regions adjacent to gray matter structures (superior frontal gyrus, dorsolateral prefrontal medial frontal cortex; inferior frontal gyrus, caudate, insulate cortex, parietal cortex, supramarginal and lingual gyri, and thalamus). These white matter alterations may help explaining the diversity of OCD psychological impairments in inhibitory control, emotional regulation, memory and visual spatial processing.The authors have no financial or personal conflicts of interest. The first author was funded by the Brazilian National Counsel for Scientific and Technological Development (CNPq) as a Special Visiting Researcher of the Science Without Borders program (grant number: 401143/2014-7). This study was partially conducted at the Neuropsychophysiology Lab from the Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145- FEDER-007653).info:eu-repo/semantics/publishedVersio