Fluências Verbais e Funcionamento Executivo em Idosos Institucionalizados do Distrito de Coimbra

Contexto: As fluências verbais (FV) podem ser consideradas marcadores do funcionamento executivo (FE) e as investigações mostram que as duas se associam. Faltam estudos com idosos portugueses nestes domínios e dos aspetos que se lhe associam. Objetivos: Descrever as pontuações médias das FV e suas componentes (agrupamento e alternância) e do FE; analisar a relação entre as FV e suas componentes e as variáveis sociodemográficas; 3) analisar a relação entre as FV e suas componentes e as FE, controlando as variáveis sociodemográficas; 4) analisar a relação entre as FV e suas componentes e as variáveis emocionais e 5) explorar o papel preditivo das variáveis com as quais tenhamos encontrado associações significativas para as FV e suas componentes. Metodologia: Utilizando uma amostragem de conveniência, foram inquiridos 256 idosos, com idades compreendidas entre os 65 e os 100 anos, 72,3% eram mulheres: a maioria tinha companheiro (56,5%), baixa escolaridade (67,7%) e profissão essencialmente manual (85,2%). As FV foram avaliadas foneticamente (letras P, M, R) e semânticamente (animais e alimentos); as FV foram avaliadas com a Frontal Assessment Battery (FAB); os sintomas depressivos por meio do Geriatric Anxiety Inventory (GDS); os sintomas ansiosos por meio do Geriatric Anxiety Inventory (GAI) e para avaliar a satisfação com a vida utilizou-se a Satisfaction With Life Scale (SWLS). Resultado: Os valores médios nas fluências fonémicas totais foram de 4,13 (DP = 2,81) e na semântica de 7,64 (DP = 3,47). As FV e a componente alternância, foram significativamente diferentes nos grupos definidos pela escolaridade e pela profissão. As fluências e a alternância correlacionam-se de forma significativa com o FE. Comprovámos também que a fluência fonémica e semântica apresentam correlações significativamente com o GDS; a fonémica também se correlaciona com o PANAS negativo, a alternância apresenta correlações com todas as variáveis emocionais, exceto com o SWLS. Conclusão: Sendo a avaliação do funcionamento executivo importante para o diagnóstico precoce de do declínio frontal, saber quais as variáveis que se lhe associam é importante para a reabilitação cognitiva./ Background: The verbal fluencies (VF) can be considered markers of executive functioning (EF) and investigations show that the two are associated. There is a gap in Portuguese studies with elderly in these areas and aspects associated. Objectives: To describe the average scores of VF and its components (clustering and switching) and EF; analyze the relationship between the VF and its components and sociodemographic variables, 3) analyze the relationship between the VF and its components and the EF, controlling sociodemographic variables; 4) analyze the relationship between the VF and its components and emotional variables; and 5) explore the role of predictive variables which we found significant associations for VF and its components. Methodology: Using a convenience sample, we questioned 256 elderly people with 65 to 100 years old, 72.3% were women, most had a partner (56.5%), low education (67.7%) and mainly a manual profession (85.2%). The VF were evaluated phonetically (letters P, M, R), and semantically (animals and food); the VF were evaluated with the Frontal Assessment Battery (FAB); depressive symptoms with the Geriatric Anxiety Inventory (GDS), the anxiety symptoms through the Geriatric Anxiety Inventory (GAI), and to assess satisfaction with life we used the Satisfaction With Life Scale (SWLS). Results: The phonemic means total scores were 7.64 (SD = 3.47). The VF and switching component, were significantly different between the groups defined by education and profession. The fluencies and the switching correlate significantly with the EF. We also confirmed that phonemic and semantic fluencies have significantly correlations with GDS, the phonemic also correlates with the negative PANAS, switching shows correlation with all the emotional variables, except with the SWLS. Conclusion: Since the assessment of executive functioning is important for early diagnosis of frontal decline, knowing which variables associate with executive functioning are important for cognitive rehabilitation

A Model Predictive Approach for Enhancing Transient Stability of Grid-Forming Converters

A model-based approach for controlling post-fault transient stability of grid-forming (GFM) converter energy resources is designed and analyzed. This proposed controller is activated when the converter enters into the saturated current operation mode. It aims at mitigating the issues arising from insufficient post-fault deceleration due to current saturation and thus improving the transient stability of the GFM Inverter Based Resources (IBRs). The considered approach conveniently modifies the post-fault trajectory of GFM IBRs by introducing appropriate corrective phase angle jumps and power references. These corrections are optimised following a model predictive approach (the model referring to post-fault dynamics of GFM IBRs in both saturated and normal operation modes). While constructing the proposed controller, the situation for GFM IBRs to enter into the saturated operation mode are identified. The effectiveness of this transient stability enhancement approach by means of dynamic simulations under various grid conditions is tested and discussed. The results demonstrate much better transient stability performance.Comment: 14 pages, 19 figure

Predictive Resource Allocation in mmWave Systems with Rotation Detection

Millimeter wave (MmWave) has been regarded as a promising technology to support high-capacity communications in 5G era. However, its high-layer performance such as latency and packet drop rate in the long term highly depends on resource allocation because mmWave channel suffers significant fluctuation with rotating users due to mmWave sparse channel property and limited field-of-view (FoV) of antenna arrays. In this paper, downlink transmission scheduling considering rotation of user equipments (UE) and limited antenna FoV in an mmWave system is optimized via a novel approximate Markov decision process (MDP) method. Specifically, we consider the joint downlink UE selection and power allocation in a number of frames where future orientations of rotating UEs can be predicted via embedded motion sensors. The problem is formulated as a finite-horizon MDP with non-stationary state transition probabilities. A novel low-complexity solution framework is proposed via one iteration step over a base policy whose average future cost can be predicted with analytical expressions. It is demonstrated by simulations that compared with existing benchmarks, the proposed scheme can schedule the downlink transmission and suppress the packet drop rate efficiently in non-stationary mmWave links.Comment: 7 pages, 5 figures. Paper accepted for publication in IEEE International Conference on Communications, 202

Beam Orientation Optimization for Intensity Modulated Radiation Therapy using Adaptive l1 Minimization

Beam orientation optimization (BOO) is a key component in the process of IMRT treatment planning. It determines to what degree one can achieve a good treatment plan quality in the subsequent plan optimization process. In this paper, we have developed a BOO algorithm via adaptive l_1 minimization. Specifically, we introduce a sparsity energy function term into our model which contains weighting factors for each beam angle adaptively adjusted during the optimization process. Such an energy term favors small number of beam angles. By optimizing a total energy function containing a dosimetric term and the sparsity term, we are able to identify the unimportant beam angles and gradually remove them without largely sacrificing the dosimetric objective. In one typical prostate case, the convergence property of our algorithm, as well as the how the beam angles are selected during the optimization process, is demonstrated. Fluence map optimization (FMO) is then performed based on the optimized beam angles. The resulted plan quality is presented and found to be better than that obtained from unoptimized (equiangular) beam orientations. We have further systematically validated our algorithm in the contexts of 5-9 coplanar beams for 5 prostate cases and 1 head and neck case. For each case, the final FMO objective function value is used to compare the optimized beam orientations and the equiangular ones. It is found that, our BOO algorithm can lead to beam configurations which attain lower FMO objective function values than corresponding equiangular cases, indicating the effectiveness of our BOO algorithm.Comment: 19 pages, 2 tables, and 5 figure

Open charm production in sNN\sqrt{s_{NN}}=200 GeV Au+Au collisions

We report on the measurement of D meson production from the analysis of their hadronic ($D^0\to K\pi$) and semileptonic ($D\to \mu+X$, $D\to e+X$) decays in $\sqrt{s_{NN}}$=200 GeV Au+Au collisions. The transverse momentum ($p_T$) spectra and the nuclear modification factors for $D^0$ and for electron/muon from charm semileptonic decays will be presented. The differential cross section $d\sigma/dy$ is found to be consistent with the number of binary scaling. The blast-wave fit suggests that the charm hadron freeze out earlier than other light flavor hadrons.Comment: 4 pages, 2 figures, presentation at Strangeness in Quark Matter 2006, accepted for publication by Journal of Physics

GPU-based Iterative Cone Beam CT Reconstruction Using Tight Frame Regularization

X-ray imaging dose from serial cone-beam CT (CBCT) scans raises a clinical concern in most image guided radiation therapy procedures. It is the goal of this paper to develop a fast GPU-based algorithm to reconstruct high quality CBCT images from undersampled and noisy projection data so as to lower the imaging dose. For this purpose, we have developed an iterative tight frame (TF) based CBCT reconstruction algorithm. A condition that a real CBCT image has a sparse representation under a TF basis is imposed in the iteration process as regularization to the solution. To speed up the computation, a multi-grid method is employed. Our GPU implementation has achieved high computational efficiency and a CBCT image of resolution 512\times512\times70 can be reconstructed in ~5 min. We have tested our algorithm on a digital NCAT phantom and a physical Catphan phantom. It is found that our TF-based algorithm is able to reconstrct CBCT in the context of undersampling and low mAs levels. We have also quantitatively analyzed the reconstructed CBCT image quality in terms of modulation-transfer-function and contrast-to-noise ratio under various scanning conditions. The results confirm the high CBCT image quality obtained from our TF algorithm. Moreover, our algorithm has also been validated in a real clinical context using a head-and-neck patient case. Comparisons of the developed TF algorithm and the current state-of-the-art TV algorithm have also been made in various cases studied in terms of reconstructed image quality and computation efficiency.Comment: 24 pages, 8 figures, accepted by Phys. Med. Bio