Temporal SNR characteristics in segmented 3D-EPI at 7T.

Three-dimensional segmented echo planar imaging (3D-EPI) is a promising approach for high-resolution functional magnetic resonance imaging, as it provides an increased signal-to-noise ratio (SNR) at similar temporal resolution to traditional multislice 2D-EPI readouts. Recently, the 3D-EPI technique has become more frequently used and it is important to better understand its implications for fMRI. In this study, the temporal SNR characteristics of 3D-EPI with varying numbers of segments are studied. It is shown that, in humans, the temporal variance increases with the number of segments used to form the EPI acquisition and that for segmented acquisitions, the maximum available temporal SNR is reduced compared to single shot acquisitions. This reduction with increased segmentation is not found in phantom data and thus likely due to physiological processes. When operating in the thermal noise dominated regime, fMRI experiments with a motor task revealed that the 3D variant outperforms the 2D-EPI in terms of temporal SNR and sensitivity to detect activated brain regions. Thus, the theoretical SNR advantage of a segmented 3D-EPI sequence for fMRI only exists in a low SNR situation. However, other advantages of 3D-EPI, such as the application of parallel imaging techniques in two dimensions and the low specific absorption rate requirements, may encourage the use of the 3D-EPI sequence for fMRI in situations with higher SNR.

Trabalho da enfermeira intensivista: um estudo da estrutura das representações sociais

Buscou-se caracterizar as representações sociais do trabalho da enfermeira em unidade de tratamento intensivo (UTI) mediante a determinação do núcleo central e do sistema periférico. Foi realizado em cinco UTIs de dois hospitais de ensino, pesquisa e assistência, sendo um público e outro filantrópico da cidade de Salvador-Bahia. A coleta de dados foi efetivada pela associação livre de palavras ao termo indutor: trabalho da enfermeira em UTI com noventa enfermeiras. Os dados foram processados pelo software EVOC e analisados por meio da construção da tabela de quatro casas, fundamentadas na teoria das representações sociais com abordagem estrutural. Os resultados indicam como elementos centrais: estresse, responsabilidade, assistência integral e gratificação. Como sistema periférico, elementos atitudinais profissionais e pessoais necessários ao trabalho. Conclui-se que o trabalho estressante de responsabilidade é amenizado pela gratificação de prestar assistência integral, o que exige uma diversidade de atributos pessoais e profissionais.

Estrutura organizacional do serviço de enfermagem: reflexões sobre a influência do poder e da cultura organizacional

Este estudo discute a cultura e o poder influenciando a estrutura organizacional do serviço de enfermagem em um hospital de ensino. A partir da necessidade de padronizar os procedimentos de enfermagem por parte da administração geral do hospital, foi desenhada a estrutura organizacional (organograma) do Serviço de Enfermagem. Por causa desta situação, veio à tona o interesse dos enfermeiros gestores em ampliar o espaço de poder, fortalecendo a Enfermagem no ambiente intra-institucional.

Lateralization of olfactory processing: Differential impact of right and left temporal lobe epilepsies.

Olfactory processes were reported to be lateralized. The purpose of this study was to further explore this phenomenon and investigate the effect of the hemispheric localization of epileptogenic foci on olfactory deficits in patients with temporal lobe epilepsy (TLE). Olfactory functioning was assessed in 61 patients and 60 healthy control (HC) subjects. The patients and HC subjects were asked to rate the intensity, pleasantness, familiarity, and edibility of 12 common odorants and then identify them. Stimulations were delivered monorhinally in the nostril ipsilateral to the epileptogenic focus in TLE and arbitrarily in either the left or the right nostril in the HC subjects. The results demonstrated that regardless of the side of stimulation, patients with TLE had reduced performance in all olfactory tasks compared with the HC subjects. With regard to the side of the epileptogenic focus, patients with left TLE judged odors as less pleasant and had more difficulty with identification than patients with right TLE, underlining a privileged role of the left hemisphere in the emotional and semantic processing of odors. Finally, irrespective of group, a tendency towards a right-nostril advantage for judging odor familiarity was found in agreement with a prominent role of the right hemisphere in odor memory processing.

Biodiversity and global change in Mediterranean benthic communities: perspectives over large spatial and long temporal scales

Many terrestrial and marine systems are experiencing accelerating decline due to the effects of global change. This situation has raised concern about the consequences of biodiversity losses for ecosystem function, ecosystem service provision, and human well-being. Coastal marine habitats are a main focus of attention because they harbour a high biological diversity, are among the most productive systems of the world and present high anthropogenic interaction levels. The accelerating degradation of many terrestrial and marine systems highlights the urgent need to evaluate the consequence of biodiversity loss. Because marine biodiversity is a dynamic entity and this study was interested global change impacts, this study focused on benthic biodiversity trends over large spatial and long temporal scales. The main aim of this project was to investigate the current extent of biodiversity of the high diverse benthic coralligenous community in the Mediterranean Sea, detect its changes, and predict its future changes over broad spatial and long temporal scales. These marine communities are characterized by structural species with low growth rates and long life spans; therefore they are considered particularly sensitive to disturbances. For this purpose, this project analyzed permanent photographic plots over time at four locations in the NW Mediterranean Sea. The spatial scale of this study provided information on the level of species similarity between these locations, thus offering a solid background on the amount of large scale variability in coralligenous communities; whereas the temporal scale was fundamental to determine the natural variability in order to discriminate between changes observed due to natural factors and those related to the impact of disturbances (e.g. mass mortality events related to positive thermal temperatures, extreme catastrophic events). This study directly addressed the challenging task of analyzing quantitative biodiversity data of these high diverse marine benthic communities. Overall, the scientific knowledge gained with this research project will improve our understanding in the function of marine ecosystems and their trajectories related to global change.

An easy and safe procedure for temporal artery biopsy.

BACKGROUND: Temporal arteritis is a very serious form of vasculitis. Early treatment is essential to avoid blindness. Surgical biopsy of the temporal artery is the gold standard for the diagnosis, but facial nerve injuries may occur. OBJECTIVE: To describe a simple and safe procedure for temporal artery biopsy. METHODS: Case report. RESULTS: A 62-year-old-woman with presumed temporal arteritis was referred. Precise localization of temporal arteries and its branches was obtained with color duplex ultrasonography. Arterial wall thickening (halo sign) was observed in the affected arterial segments. A frontal branch was precisely localized and infiltrated with 1% lidocaine. About 1 cm was removed for histopathologic examination. Thirty minutes was required to perform this outpatient procedure. The diagnosis of temporal arteritis was confirmed, and the patient was rapidly and successfully treated with prednisone. CONCLUSIONS: Color duplex ultrasonography allows precise localization of temporal arteries and its branches. This echocardiography-guided surgical procedure is easy and safe. Most dermatologic surgeons can perform it.

Avaliação da estrutura destinada à consulta de enfermagem à criança na atenção básica

Objetivou-se avaliar a qualidade da estrutura disponível para a consulta de enfermagem prestada à criança de até um ano de idade, em unidades básicas do Programa de Saúde da Família do Município de São Paulo. O referencial teórico contemplou componentes da abordagem de estrutura da concepção sistêmica da avaliação de serviços de saúde. Os dados foram coletados mediante observação sistematizada da estrutura existente para a realização de 114 consultas de enfermagem prestadas por 14 enfermeiras, utilizando um instrumento validado por 11 especialistas e aplicação de questionário respondido pelas enfermeiras. A avaliação tanto da área física, instalações e materiais, como da qualificação profissional dessas enfermeiras, foi considerada satisfatória por atender a grande maioria dos critérios normativos adotados.

Validation française de l'échelle d'expérience temporelle du plaisir [Validation of the Temporal Experience of Pleasure Scale (TEPS) in a French-speaking environment.]

INTRODUCTION: Anhedonia is defined as a diminished capacity to experience pleasant emotion and is commonly included among the negative symptoms of schizophrenia. However, if patients report experiencing a lower level of pleasure than controls, they report experiencing as much pleasure as controls with online measurements of emotion. OBJECTIVE: The Temporal Experience of Pleasure Scale (TEPS) measures pleasure experienced in the moment and in anticipation of future activities. The TEPS is an 18-item self-report measurement of anticipatory (10 items) and consummatory (eight items) pleasure. The goal of this paper is to assess the psychometric characteristics of the French translation of this scale. METHODS: A control sample was composed of 60 women and 22 men, with a mean age of 38.1 years (S.D.: 10.8). Thirty-six were without qualification and 46 with qualified professional diploma. A sample of 21 patients meeting DSM IV-TR criteria for schizophrenia was recruited among the community psychiatry service of the department of psychiatry in Lausanne. They were five women and 16 men; mean age was of 34.1 years (S.D.: 7.5). Ten obtained a professional qualification and 11 were without qualification. None worked in competitive employment. Their mean dose of chlorpromazine equivalent was 431mg (S.D.: 259). All patients were on atypical antipsychotics. The control sample fulfilled the TEPS and the Physical Anhedonia Scale (PAS). The patient sample fulfilled the TEPS and was independently rated on the Calgary Depression Scale and the Scale for Assessment of Negative Symptoms. For comparison with controls, patients were matched on age, sex and professional qualification. This required the supplementary recruitment of two control subjects. RESULTS: Results with the control sample indicate that the TEPS presents an acceptable internal validity with Crombach alphas of 0.84 for the total scale, 0.74 for the anticipatory pleasure scale and 0.79 for the consummatory pleasure scale. The confirmatory factor analysis indicated that the model is well adapted to our data (chi(2)/dl=1.333; df=134; p<0.0006; root mean square residual, RMSEA=0.064). External validity measured with the PAS showed R=-0.27 (p<0.05) for the consummatory scale and R=-0.26 for the total score. Comparisons between patients and matched controls indicated that patients were significantly lower than control on anticipatory pleasure (t=2.7, df(40), 2-tailed p=0.01; cohen's d=0.83) and on total score of the TEPS (t=2.8, df (40), 2-tailed p=0.01; cohen's d=0.87). The two samples did not differ on consummatory pleasure. The anticipatory pleasure factor and the total TEPS showed significant negative correlation with the SANS anhedonia, respectively R=-0.78 (p<0.01) for the anticipatory factor and R=-0.61 (p<0.01) for the total TEPS. There was also a negative correlation between the anticipatory factor and the SANS avolition of R=-0.50 (p<0.05). These correlations were maintained, with partial correlations controlling for depression and chlorpromazine equivalents. CONCLUSION: The results of this validation show that the French version of the TEPS has psychometric characteristics similar to the original version. These results highlight the discrepancy between results of direct or indirect report of experienced pleasure in patients with schizophrenia. Patients may have difficulties in anticipating the pleasure of future enjoyable activities, but not in experiencing pleasure once in an enjoyable activity. Medication and depression do not seems to modify our results, but this should be better controlled in a longitudinal study. The anticipatory versus consummatory pleasure distinction appears to be useful for the development of new psychosocial interventions, tailored to improve desire in patients suffering from schizophrenia. Major limitations of the study are the small size of patient sample and the under representation of men in the control sample.

Bilinear models for spatio-temporal point distribution analysis: application to extrapolation of left ventricular, biventricular and whole heart cardiac dynamics

In this work we describe the usage of bilinear statistical models as a means of factoring the shape variability into two components attributed to inter-subject variation and to the intrinsic dynamics of the human heart. We show that it is feasible to reconstruct the shape of the heart at discrete points in the cardiac cycle. Provided we are given a small number of shape instances representing the same heart atdifferent points in the same cycle, we can use the bilinearmodel to establish this. Using a temporal and a spatial alignment step in the preprocessing of the shapes, around half of the reconstruction errors were on the order of the axial image resolution of 2 mm, and over 90% was within 3.5 mm. From this, weconclude that the dynamics were indeed separated from theinter-subject variability in our dataset.

Temporal diffeomorphic free-form deformation: application to motion and strain estimation from 3D echocardiography

This paper presents a new registration algorithm, called Temporal Di eomorphic Free Form Deformation (TDFFD), and its application to motion and strain quanti cation from a sequence of 3D ultrasound (US) images. The originality of our approach resides in enforcing time consistency by representing the 4D velocity eld as the sum of continuous spatiotemporal B-Spline kernels. The spatiotemporal displacement eld is then recovered through forward Eulerian integration of the non-stationary velocity eld. The strain tensor iscomputed locally using the spatial derivatives of the reconstructed displacement eld. The energy functional considered in this paper weighs two terms: the image similarity and a regularization term. The image similarity metric is the sum of squared di erences between the intensities of each frame and a reference one. Any frame in the sequence can be chosen as reference. The regularization term is based on theincompressibility of myocardial tissue. TDFFD was compared to pairwise 3D FFD and 3D+t FFD, bothon displacement and velocity elds, on a set of synthetic 3D US images with di erent noise levels. TDFFDshowed increased robustness to noise compared to these two state-of-the-art algorithms. TDFFD also proved to be more resistant to a reduced temporal resolution when decimating this synthetic sequence. Finally, this synthetic dataset was used to determine optimal settings of the TDFFD algorithm. Subsequently, TDFFDwas applied to a database of cardiac 3D US images of the left ventricle acquired from 9 healthy volunteers and 13 patients treated by Cardiac Resynchronization Therapy (CRT). On healthy cases, uniform strain patterns were observed over all myocardial segments, as physiologically expected. On all CRT patients, theimprovement in synchrony of regional longitudinal strain correlated with CRT clinical outcome as quanti ed by the reduction of end-systolic left ventricular volume at follow-up (6 and 12 months), showing the potential of the proposed algorithm for the assessment of CRT.

Chronic deep brain stimulation in mesial temporal lobe epilepsy.

The objective of this study was to evaluate the efficiency and the effects of changes in parameters of chronic amygdala-hippocampal deep brain stimulation (AH-DBS) in mesial temporal lobe epilepsy (TLE). Eight pharmacoresistant patients, not candidates for ablative surgery, received chronic AH-DBS (130 Hz, follow-up 12-24 months): two patients with hippocampal sclerosis (HS) and six patients with non-lesional mesial TLE (NLES). The effects of stepwise increases in intensity (0-Off to 2 V) and stimulation configuration (quadripolar and bipolar), on seizure frequency and neuropsychological performance were studied. The two HS patients obtained a significant decrease (65-75%) in seizure frequency with high voltage bipolar DBS (≥1 V) or with quadripolar stimulation. Two out of six NLES patients became seizure-free, one of them without stimulation, suggesting a microlesional effect. Two NLES patients experienced reductions of seizure frequency (65-70%), whereas the remaining two showed no significant seizure reduction. Neuropsychological evaluations showed reversible memory impairments in two patients under strong stimulation only. AH-DBS showed long-term efficiency in most of the TLE patients. It is a valuable treatment option for patients who suffer from drug resistant epilepsy and who are not candidates for resective surgery. The effects of changes in the stimulation parameters suggest that a large zone of stimulation would be required in HS patients, while a limited zone of stimulation or even a microlesional effect could be sufficient in NLES patients, for whom the importance of the proximity of the electrode to the epileptogenic zone remains to be studied. Further studies are required to ascertain these latter observations.

Does locally delivered Zoledronate influence peri-implant bone formation? - Spatio-temporal monitoring of bone remodeling in vivo.

Bisphosphonates are known for their strong inhibitory effect on bone resorption. Their influence on bone formation however is less clear. In this study we investigated the spatio-temporal effect of locally delivered Zoledronate on peri-implant bone formation and resorption in an ovariectomized rat femoral model. A cross-linked hyaluronic acid hydrogel was loaded with the drug and applied bilaterally in predrilled holes before inserting polymer screws. Static and dynamic bone parameters were analyzed based on in vivo microCT scans performed first weekly and then biweekly. The results showed that the locally released Zoledronate boosted bone formation rate up to 100% during the first 17 days after implantation and reduced the bone resorption rate up to 1000% later on. This shift in bone remodeling resulted in an increase in bone volume fraction (BV/TV) by 300% close to the screw and 100% further away. The double effect on bone formation and resorption indicates a great potential of Zoledronate-loaded hydrogel for enhancement of peri-implant bone volume which is directly linked to improved implant fixation.

Language acquisition during a stay abroad period following formal instruction: temporal effects on oral fluency development

This study investigates the development of fluency in 30 advanced L2 learners of English over a period of 15 months. In order to measure fluency, several temporal variables and hesitation phenomena are analyzed and compared. Oral competence is assessed by means of an oral interview carried out by the learners. Data collection takes place at three different times: before (T1) and after (T2) a six-month period of FI (80 hours) in the home university, and after a three-month SA term (T3). The data is analyzed quantitatively. Developmental gains in fluency are measured for the whole period, adopting a view of complementarity between the two learning contexts. From these results, a group of high fluency speakers is identified. Correlations between fluency gains and individual and contextual variables are executed and a more qualitative analysis is performed for high fluency speakers' performance and behavior. Results show an overall development of students' oral fluency during a period of 15 months favored by the combination of a period of FI at home followed by a 3-months SA.

SESAM - a new framework integrating macroecological and species distribution models for predicting spatio-temporal patterns of species assemblages

Two different approaches currently prevail for predicting spatial patterns of species assemblages. The first approach (macroecological modelling, MEM) focuses directly on realised properties of species assemblages, whereas the second approach (stacked species distribution modelling, S-SDM) starts with constituent species to approximate assemblage properties. Here, we propose to unify the two approaches in a single 'spatially-explicit species assemblage modelling' (SESAM) framework. This framework uses relevant species source pool designations, macroecological factors, and ecological assembly rules to constrain predictions of the richness and composition of species assemblages obtained by stacking predictions of individual species distributions. We believe that such a framework could prove useful in many theoretical and applied disciplines of ecology and evolution, both for improving our basic understanding of species assembly across spatio-temporal scales and for anticipating expected consequences of local, regional or global environmental changes. In this paper, we propose such a framework and call for further developments and testing across a broad range of community types in a variety of environments.