62 research outputs found

    Estresse ocupacional e satisfação dos usuários com os cuidados de saúde primários em Portugal

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    The Portuguese primary healthcare sector has suffered changes due to a reform on the lines of the conceptual framework referred to by some authors as "New Public Management." These changes may be generating higher levels of occupational stress with a negative impact at individual and organizational levels. This study examines the experience of stress in 305 health professionals (physicians, nurses and clinical secretaries) and satisfaction with the services provided by them from 392 users. The population under scrutiny is taken from 10 type A and 10 type B Family Health Units (FHU). The results show that 84.2% of professionals report moderate to high levels of occupational stress with the nurses being those with higher levels. Users reported good levels of satisfaction, especially with the nursing services. There were no differences in stress level between type A and type B FHU, though there were at the level of user satisfaction of type B FHU users who show higher levels of satisfaction. It was seen that dimensions of user satisfaction were affected by stress related to excess work.info:eu-repo/semantics/publishedVersio

    Effects of Transcranial Direct Current Stimulation on Episodic Memory Related to Emotional Visual Stimuli

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    The present study investigated emotional memory following bilateral transcranial electrical stimulation (direct current of 1 mA, for 20 minutes) over fronto-temporal cortical areas of healthy participants during the encoding of images that differed in affective arousal and valence. The main result was a significant interaction between the side of anodal stimulation and image emotional valence. Specifically, right anodal/left cathodal stimulation selectively facilitated the recall of pleasant images with respect to both unpleasant and neutral images whereas left anodal/right cathodal stimulation selectively facilitated the recall of unpleasant images with respect to both pleasant and neutral images. From a theoretical perspective, this double dissociation between the side of anodal stimulation and the advantage in the memory performance for a specific type of stimulus depending on its pleasantness supported the specific-valence hypothesis of emotional processes, which assumes a specialization of the right hemisphere in processing unpleasant stimuli and a specialization of the left hemisphere in processing pleasant stimuli. From a methodological point of view, first we found tDCS effects strictly dependent on the stimulus category, and second a pattern of results in line with an interfering and inhibitory account of anodal stimulation on memory performance. These findings need to be carefully considered in applied contexts, such as the rehabilitation of altered emotional processing or eye-witness memory, and deserve to be further investigated in order to understand their underlying mechanisms of action

    Factor graph based detection approach for high-mobility OFDM systems with large FFT modes

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    In this article, a novel detector design is proposed for orthogonal frequency division multiplexing (OFDM) systems over frequency selective and time varying channels. Namely, we focus on systems with large OFDM symbol lengths where design and complexity constraints have to be taken into account and many of the existing ICI reduction techniques can not be applied. We propose a factor graph (FG) based approach for maximum a posteriori (MAP) symbol detection which exploits the frequency diversity introduced by the ICI in the OFDM symbol. The proposed algorithm provides high diversity orders allowing to outperform the free-ICI performance in high-mobility scenarios with an inherent parallel structure suitable for large OFDM block sizes. The performance of the mentioned near-optimal detection strategy is analyzed over a general bit-interleaved coded modulation (BICM) system applying low-density parity-check (LDPC) codes. The inclusion of pilot symbols is also considered in order to analyze how they assist the detection process

    High-definition tDCS of the temporo-parietal cortex enhances access to newly learned words

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    Learning associations between words and their referents is crucial for language learning in the developing and adult brain and for language re-learning after neurological injury. Non-invasive transcranial direct current stimulation (tDCS) to the posterior temporo-parietal cortex has been suggested to enhance this process. However, previous studies employed standard tDCS set-ups that induce diffuse current flow in the brain, preventing the attribution of stimulation effects to the target region. This study employed high-definition tDCS (HD-tDCS) that allowed the current flow to be constrained to the temporo-parietal cortex, to clarify its role in novel word learning. In a sham-controlled, double-blind, between-subjects design, 50 healthy adults learned associations between legal non-words and unfamiliar object pictures. Participants were stratified by baseline learning ability on a short version of the learning paradigm and pairwise randomized to active (20 mins; N = 25) or sham (40 seconds; N = 25) HD-tDCS. Accuracy was comparable during the baseline and experimental phases in both HD-tDCS conditions. However, active HD-tDCS resulted in faster retrieval of correct word-picture pairs. Our findings corroborate the critical role of the temporo-parietal cortex in novel word learning, which has implications for current theories of language acquisition

    Electrical Brain Stimulation During a Retrieval-Based Learning Task Can Impair Long-Term Memory

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    Anodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC) has been shown to improve performance on a multitude of cognitive tasks. These are, however, often simple tasks, testing only one cognitive domain at a time. Therefore, the efficacy of brain stimulation for complex tasks has yet to be understood. Using a task designed to increase learning efficiency, this study investigates whether anodal tDCS over the left DLPFC can modulate both learning ability and subsequent long-term memory retention. Using a within-subject design, participants (N = 25) took part in 6 training sessions over consecutive days in which active or sham stimulation was administered randomly (3 of each). A computer-based task was used, containing flags from countries unknown to the participants. Each training session consisted of the repetition of 8 pairs of flag/country names. Subsequently, in three testing sessions, free, cued, and timed cued recall, participants were assessed on all 48 flags they had learnt. No difference in learning speed between active and sham tDCS was found. Furthermore, in the timed cued recall phase, flags learnt in the sham tDCS sessions were recalled significantly better than flags learnt in the active tDCS sessions. This effect was stronger in the second testing session. It was also found that for the flags answered incorrectly; thus, meaning they were presented more frequently, subsequent long-term retention was improved. These results suggest that for a complex task, anodal tDCS is ineffective at improving learning speed and potentially detrimental to long-term retention when employed during encoding. This serves to highlight the complex nature of brain stimulation, providing a greater understanding of its limitations and drawbacks

    Thermogravimetry (TG) applied to the study of the reaction of mercury with platinum-rhodium alloy

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    Thermogravimetry (TG) energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM), mapping surface, X-ray diffraction (XRD), inductively coupled plasma emission spectroscopy and atomic spectroscopy with cold vapor generation have been used to study the reaction of mercury with platinum-rhodium (Pt-Rh) alloy. The results suggest that, the electrodeposited Hg film reacts with Pt-Rh to form intermetallic compounds of different stability, when heated indicated by at least four weight loss steps. Intermetallic compounds as PtHg4 and PtHg2 was characterized by XRD. These intermetallic compound are the main product presents on the surface of the samples after remotion of the bulk mercury via thermal desorption techniques. (C) 2002 Elsevier B.V. B.V. All rights reserved
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