Buybacks: short-term effect and future implications for the United States stock market

The main purpose of this work was to analyze the impact of stock buybacks on the American stock market. Firstly, the abnormal returns on the days following a repurchase transaction were calculated, and evidence was found that there are positive cumulative average abnormal returns on the days following it. Additionally, the Earnings-per-Share’s impact was analyzed indicating that there is some inflation of this metric due to buybacks. Finally, the evolution of the firms’ financial strength was analyzed, allowing to conclude that this buyback trend is harming the companies’ balance sheets and might endanger them in the future

Is the Portuguese Karate practice safe?

[EN] In Portugal, as in all over the world, the practice of martial arts and combat has been growing in recent decades

From a simple EHR to the market lead: what technologies to add

Electronic health records (EHRs) can store, capture, and present patient data in an organized way that improves physicians’ workflow and patient care. This makes EHRs key to addressing many of today’s health care challenges. An interdisciplinary review and qualitative study of artificial intelligence, machine learning, natural language processing, and real-time location services in health care was conducted. The results show that in an industry where digitization is key, several recommendations can be made to leverage these technologies in ways that can improve current systems and help EHR vendors become the market lead

Heart and brain responses to real versus simulated chess games in trained chess players: a quantitative EEG and HRV study

The aim of the present study was to investigate how the heart and the brain react to playing chess with a computer versus in a real context in chess players. We also aim to investigate if familiarization with simulated practice leads to changes in heart rate variability (HRV) and the electroencephalographic (EEG) power spectrum. We designed a cross-sectional study, enrolling 27 chess players. They were randomly assigned to 3 minutes plus 2-second chess games: one with a computer (simulated scenario), and another in a real context. Additionally, participants were divided into two groups according to their level of familiarization of playing chess in a computer context. While they were playing, HRV and EEG were continuously recorded. Differences in HRV and EEG theta power spectrum between playing chess in a real or a simulated scenario were not found in chess players (p-value > 0.05). When participants were divided into groups (familiarized and unfamiliarized with simulated chess practice), significant differences were observed in HRV and EEG (p-value < 0.05). The EEG theta power spectrum was significantly lower, and HRV was higher in unfamiliarized players during the simulated scenario, which could indicate that they were less focused in a simulated environment than in a real context. Therefore, familiarization with simulated environments should be taken into account during the training process to achieve the best performance.info:eu-repo/semantics/publishedVersio

Lesões no basquetebol português : enquadramento epidemiológico e análise biomecânica de um evento incitador da entorse do tornozelo

Tese de Doutoramento em Motricidade Humana na especialidade de FisioterapiaIntrodução: Este estudo agrupa a vertente epidemiológica através da avaliação e caracterização das lesões ocorridas durante a prática de basquetebol e a vertente de análise do movimento pela avaliação biomecânica do tornozelo, são e previamente lesionado, durante um evento comprovadamente incitador desta lesão no basquetebol, o salto para uma superfície instável. Objectivos: Avaliar o tipo, gravidade e consequências das lesões ocorridas durante a prática de basquetebol; avaliar as diferenças biomecânicas do membro inferior dos basquetebolistas com e sem ocorrência prévia de entorse do tornozelo, durante o salto. Metodologia: Na análise epidemiológica efectuou-se um estudo observacional, longitudinal e retrospectivo, de âmbito nacional em 642 basquetebolistas, durante duas épocas desportivas. Na análise cinemática e electromiográfica fez-se um estudo quasi-experimental em que participaram 24 basquetebolistas de elite dos escalões juniores cujo salto em apoio unipodal para uma tábua de Freeman foi analisado. Resultados: 51,5% dos atletas sofreu lesão, que afectou predominantemente no membro inferior (73%), seguida dos dedos da mão (17%) e provocada por contacto com outro atleta, durante o salto. A lesão mais frequente foi a entorse do tornozelo que mostra grande propensão para a recidiva. Na análise biomecânica os sujeitos com ocorrência prévia de entorse mostram menor duração da fase aérea, maior amplitude de flexão plantar do tornozelo e da extensão do joelho, e menor velocidade na recepção ao solo após o salto. Discussão e Conclusões: Os basquetebolistas portugueses sofrem elevado número de lesões, que lhes afecta sobretudo o membro inferior e especialmente o tornozelo sob a forma de entorses. Os atletas de maior idade, peso, altura, anos de experiência de basquetebol e maior volume de treino são os mais sujeitos à ocorrência de lesão. O género dos atletas, o escalão competitivo e a posição em campo são determinantes na ocorrência de lesões. Os atletas com ocorrência prévia de entorse colocam durante o salto os segmentos do membro inferior em posições facilitadoras da ocorrência dessa lesão. Mostram uma “deficiente preparação” do membro inferior para o momento de contacto com o solo e, consequentemente, para o suporte de carga, instante no qual a entorse ocorre.Background: No previous large epidemiological studies of basketball injuries in Portugal, or dynamic biomechanical analysis of the most frequent injury mechanism in basketball: jumping onto an unstable surface. Objective: Epidemiological analysis aimed to evaluate sports injuries, during practice or competition, according to their type, severity and consequences and laboratorial analysis to evaluate kinematics and electromyography differences in basketball players that have and have not suffered an ankle sprain, while jumping onto an unstable surface. Methods: Standardized data was collected retrospectively with a validated instrument from 642 athletes from all basketball categories during two sport seasons. 24 elite young athletes with healthy (n=29) and already sprained ankles (17) underwent five consecutive jumps in unipodal support onto a round Freeman board. Results: A total of 330 athletes sustained 599 injuries (51.5% of players injured) over the 2-year study period. The greatest number of injuries occurred in the lower leg followed by fingers. The most common injury mechanism was contact with another player, especially during a jump. The most frequent injury was ankle sprain that highly tend to reoccur. During jumping athletes with already sprained ankles demonstrated less flight time, ankles in a more plantar flexed position, greater knee extension and smaller linear thigh and foot velocity during landing. Discussion and Conclusions: High level of injury incidence in Portuguese basketball players, especially ankle sprains. On average, athletes that suffered injuries are older, taller, and heavier, have practiced for more years, and are also those subjected to greater practice volumes. The sex, competitive level and positions players occupy have different injury occurrence risks. Biomechanical results showed different motor behaviour of the lower leg in athletes with prior history of ankle sprain compared to healthy athletes, which could eventually facilitate sprain mechanisms. These results strengthen the idea that preparation for landing during jumping, moment when ankle sprain, is inefficient in athletes with prior history of ankle sprain.FSE - PRODEP II

Development of a PCR-RFLP marker to genetically distinguish Prosorhynchus crucibulum and Prosorhynchus aculeatus

The cercariae stages of Prosorhynchus crucibulum and Prosorhynchus aculeatus are morphologically indistinguishable. However, the differentiation of these two species is crucial to understand the transmission dynamics between these primary hosts (mussels) and the secondary hosts (fish). In this way, the objective of this study is to develop an accurate molecular identification tool to differentiate the cercariae stage of P. crucibulum and P. aculeatus. We targeted the 18S nuclear ribosomal DNA region by PCR amplification and sequenced this amplicon. By generating these sequences, we developed a RFLP tool with the use of the enzymes HincII and FokI that produced different restriction profiles between P. crucibulum and P. aculeatus. Each enzyme generated different-sized fragments specific to the species examined and no cross-reaction between the species was detected in their restriction pattern. By sequencing, no intraspecific-polymorphism was detected since there is 100% homology among P. aculeatus or P. crucibulum. These results indicate that PCR-linked restriction analysis of the 18S rDNA region provided us with rapid and reliable molecular tools for distinction of the cercariae of these species. The sequences generated were deposited in GenBank accession numbers for P. crucibulum cercariae (FJ463407, FJ463408 and FJ463409) and adult worm (FJ429096, FJ429097), and for P. aculeatus adult (FJ429094 and FJ429095)

Gait Kinematics Analysis of Flatfoot Adults

Background: Foot postural alignment has been associated with altered gait pattern. This study aims to investigate gait kinematic differences in flatfoot subjects’ regarding all lower limb segments compared to neutral foot subjects. Methods: A total of 31 participants were recruited (age: 23.26 yo 4.43; height: 1.70 m 0.98; weight: 75.14 kg 14.94). A total of 15 subjects were integrated into the flatfoot group, and the remaining 16 were placed in the neutral foot group. All of the particpants were screened using the Navicular Drop Test and Resting Calcaneal Stance Position test to characterize each group, and results were submitted to gait analysis using a MOCAP system. Results: Significant kinematic differences between groups were found for the ankle joint dorsiflexion, abduction, and internal and external rotation (p < 0.05). Additionally, significant differences were found for the knee flexion, extension, abduction, and external rotation peak values (p < 0.001). Significant differences were also found for the hip flexion, extension, external rotation, pelvis rotation values (p < 0.02). Several amplitude differences were found concerning ankle abduction/adduction, knee flexion/extension and abduction/adduction, hip flexion/extension and rotation, and pelvis rotation (p < 0.01). Conclusion: Flatfooted subjects showed kinematic changes in their gait patterns. The impact on this condition on locomotion biomechanical aspects is clinically essential, and 3D gait biomechanical analysis use could be advantageous in the early detection of health impairments related to foot posture

Cover or velocity: What triggers iberian barbel (Luciobarbus Bocagei) refuge selection under experimental hydropeaking conditions?

Producción CientíficaThe rapid river flow variations due to hydropower production during peak demand periods, known as hydropeaking, causes several ecological impacts. In this study, we assessed the potential of an overhead cover and velocity-refuge structure in an indoor flume as an indirect hydropeaking mitigation measure for the cyprinid species Iberian barbel (Luciobarbus bocagei). We designed a lab-scale LUNKERS-type structure using two different materials which were used separately: Wood (opaque) and acrylic (transparent), tested under hydropeaking and base-flow events. Physiological (glucose and lactate) and behavioral (structure use) responses were quantified. The structure use (inside and in the vicinity) and the individual and schooling behavior was assessed. Although there was no evidence that the hydropeaking event triggered a physiological response, the wood structure use was significantly higher than the acrylic one, where the metrics of use increased in the hydropeaking event. Differences between individual and group behavior were only higher for the entrances in the wood structure. The higher frequency of wood structure use under hydropeaking conditions suggests that the visual stimulus conferred by this shaded refuge enables fish to easily find it. The results suggest that the use of overhead and velocity-refuge structures may act as an effective hydropeaking flow-refuge mitigation measure.Fundação para a Ciência e a Tecnologia, Portugal (grant PD/BD/114336/2016)Junta de Castilla y Leon - Fondo Social Europeo (grant PIF-2017