A confiança em questão. Raias de confiança, confiança das raias nas sociedades modernas

A confiança, este sentimento que faz com confiemos em nós mesmos e nos outros, surge com a vida, com a membrana que separa a (in)segurança e a vida individual e social. É quem garante o compromisso mais ou menos arriscado no jogo das permutas inter-individuais e sociais. Este artigo propõe uma perspectiva histórica do pensamento de clássicos da filosofia e da sociologia a este respeito. O apelo ao pensamento de G. Simmel, em particular, em correlação com o segredo, destaca o impacto social da confiança em termos de coesão social. Por fim, a nossa análise estruturando-se em torno de acontecimentos marcantes da actualidade, estuda os meandros da confiança nas sociedades ultramodernas.The trust, a feeling that comes with life, with the membrane that separates the security and insecurity and individual and social life, is what ensures the commitment more or less risky in the game of exchanges between individuals and society. This article begins by proposing a socio-historical thinking of the classics of philosophy and sociology in this regard. The appeal to the thinking of G. Simmel, in particular, in correlation with his theory about the secret, highlights the impact of trust in terms of social cohesion. Finally, our analysis is structured around key events of today, studying the intricacies of trust in ultramodern societies where the mechanisms of trust seems to be rather fragile

Sucesso e insucesso no ensino básico : relevância de variáveis sócio-familiares e escolares em alunos do 5º ano

Tomando a globalidade dos alunos do 5º ano de uma EB2,3 da cidade de Braga, procedemos à caracterização destes alunos em termos de variáveis sócio-culturais, familiares e escolares. Particular destaque foi dado no estudo ao acompanhamento educativo e escolar que os alunos recebem no seio da família, assim como à forma como os alunos vivenciam a sua escola. Os resultados consideram os alunos diferenciados segundo o género e segundo o seu índice de aproveitamento escolar no final do ano lectivo. Em face da reduzida percentagem de alunos que não transitaram no final do ano lectivo, a opção foi por calcular a média das classificações nas várias disciplinas e, a partir dessa média, formar o grupo dos alunos com melhor e mais fraco rendimento. Algumas diferenças nos resultados, segundo o género e segundo o rendimento do aluno, são apresentadas e discutidas, mormente aquelas que poderão justificar alguma atenção por parte da escola e dos professores

Verbal and visual stimulation effects on rectus femoris and biceps femoris muscles during isometric and concentric

Background: Coactivation may be both desirable (injury prevention) or undesirable (strength measurement). In this context, different styles of muscle strength stimulus have being investigated. In this study we evaluated the effects of verbal and visual stimulation on rectus femoris and biceps femoris muscles contraction during isometric and concentric. Methods: We investigated 13 men (age =23.1 ± 3.8 years old; body mass =75.6 ± 9.1 kg; height =1.8 ± 0.07 m). We used the isokinetic dynamometer BIODEX device and an electromyographic (EMG) system. We evaluated the maximum isometric and isokinetic knee extension and flexion at 60°/s. The following conditions were evaluated: without visual nor verbal command (control); verbal command; visual command and; verbal and visual command. In relation to the concentric contraction, the volunteers performed five reciprocal and continuous contractions at 60°/s. With respect to isometric contractions it was made three contractions of five seconds for flexion and extension in a period of one minute. Results: We found that the peak torque during isometric flexion was higher in the subjects in the VVC condition (p > 0.05). In relation to muscle coactivation, the subjects presented higher values at the control condition (p > 0.05). Conclusion: We suggest that this type of stimulus is effective for the lower limbs

Musical auditory stimulation at different intensities and its effects on the geometric indices of heart-rate variability

Introduction: Previous studies have shown that relaxation music increases the heart's parasympathetic modulation as well as reducing its sympathetic activity. However, what is lacking in the literature is information on the acute effects of different intensities of music on cardiac autonomic regulation. We aimed to evaluate the acute effects of baroque and heavy-metal music on cardiac autonomic regulation at different intensities. Method The study was performed in 16 healthy men aged between 18 and 25 years. The main outcomes were the geometric indices of heart-rate variability (HRV) [i.e. triangular index (RRtri); triangular interpolation of RR intervals (TINN) and Poincaré plot: SD1, SD2 and SD1/SD2 ratio]. First, HRV was recorded at rest for 10 min. The volunteers were then exposed to baroque or heavy-metal music for 5 min through an earphone; subjects were exposed to each song at three different sound levels (60–70, 70–80 and 80–90 decibels). After the first song, subjects remained at rest for 5 min before being exposed to the next song. The sequence of songs and sound intensity were randomised for each individual. Results Musical auditory stimulation with baroque music did not influence the geometric indices of HRV. The same was observed with heavy-metal musical auditory stimulation at the three sound-level ranges. Conclusion Musical auditory stimulation at different sound intensities did not influence the geometric indices of HRV in men

Cardiac autonomic regulation during exposure to auditory stimulation with classical baroque or heavy metal music of different intensities

Objectives: The effects of chronic music auditory stimulation on the cardiovascular system have been investigated in the literature. However, data regarding the acute effects of different styles of music on cardiac autonomic regulation are lacking. The literature has indicated that auditory stimulation with white noise above 50 dB induces cardiac responses. We aimed to evaluate the acute effects of classical baroque and heavy metal music of different intensities on cardiac autonomic regulation. Study design: The study was performed in 16 healthy men aged 18-25 years. All procedures were performed in the same soundproof room. We analyzed heart rate variability (HRV) in time (standard deviation of normal-to-normal R-R intervals [SDNN], root-mean square of differences [RMSSD] and percentage of adjacent NN intervals with a difference of duration greater than 50 ms [pNN50]) and frequency (low frequency [LF], high frequency [HF] and LF/HF ratio) domains. HRV was recorded at rest for 10 minutes. Subsequently, the volunteers were exposed to one of the two musical styles (classical baroque or heavy metal music) for five minutes through an earphone, followed by a five-minute period of rest, and then they were exposed to the other style for another five minutes. The subjects were exposed to three equivalent sound levels (60- 70dB, 70-80dB and 80-90dB). The sequence of songs was randomized for each individual. Results: Auditory stimulation with heavy metal music did not influence HRV indices in the time and frequency domains in the three equivalent sound level ranges. The same was observed with classical baroque musical auditory stimulation with the three equivalent sound level ranges. Conclusion: Musical auditory stimulation of different intensities did not influence cardiac autonomic regulation in men

Fractal dynamics of heart rate variability for short term

The fractal analysis of heart rate variability (HRV) has been associated to the chaos theory. We evaluated the association of the fractal exponents of HRV with the time and frequency domain and geometric indices of HRV for short period. HRV was analyzed with a minimal number of 256 RR intervals in the time (SDNN-standard deviation of normal-to-normal R-R intervals, pNN50-percentage of adjacent RR intervals with a difference of duration greater than 50ms and RMSSD-root-mean square of differences between adjacent normal RR intervals in a time interval) and frequency (LF-low frequency, HF-high frequency and LF/HF ratio) domains. The geometric indexes were also analyzed (RRtri-triangular index, TINN-triangular interpolation of RR intervals and Poincaré plot) as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). We observed strong correlation of the alpha-1 exponent with RMSSD, pNN50, SDNN/RMSSD, LF (nu), HF (nu), LF/HF ratio, SD1 and SD1/Sd2 ratio. In conclusion, we suggest that the alpha-1 exponent could be applied for HRV analysis with a minimal number of 256 RR intervals