862 resultados para Pilot study


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A pilot study was conducted to determine the effect of a 10-week, low intensity, exercise training program on fear of falling and gait in fifty (mean age 78.1 years, 79% women) community-dwelling volunteers. Fear of falling (measured by falls self-efficacy) and gait performance were assessed at baseline and one week after program completion. At follow-up, participants modestly improved their falls self-efficacy and gait speed. To investigate whether this effect differed according to participants' fear of falling, secondary analyses stratified by subject's baseline falls efficacy were performed. Subjects with lower than average falls efficacy improved significantly their falls efficacy and gait performance, while no significant change occurred in the others. Small but significant improvements occurred after this pilot training program, particularly in subjects with low baseline falls efficacy. These results suggest that measures of falls efficacy might be useful for better targeting individuals most likely to benefit from similar training programs.

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rejection can lead to loss of function. Histological reading of endomyocardial biopsy remains the "gold standard" for guiding immunosuppression, despite its methodological limitations (sampling error and interobserver variability). The measurement of the T2 relaxation time has been suggested for detection of allograft rejection, on the pathophysiological basis that the T2 relaxation time prolongs with local edema resulting from acute allograft rejection. Using breath-held cardiac magnetic resonance T2 mapping at 1.5 T, Usman et al. (CircCardiovascImaging2012) detected moderate allograft rejection (grade 2R, ISHLT 2004). With modern immunosuppression grade 2R rejection has become a rare event, but the need remains for a technique that permits the discrimination of absent (grade 0R) and mild rejection (grade 1R). We therefore investigated whether an increase of magnetic field strength to 3T and the use of real-time navigator-gated respiration compensation allow for an increase in the sensitivity of T2 relaxation time detection that is necessary to achieve this discrimination. Methods: Eighteen patients received EMB (Tan et al., ArchPatholLabMed2007) and cardiac T2 mapping on the same day. Reading of T2 maps was blinded to the histological results. For final analysis, 3 cases with known 2R rejection at the time of T2 mapping were added, yielding 21 T2 mapping sessions. A respiration-navigator-gated radial gradient-recalled-echo pulse sequence (resolution 1.17 mm2, matrix 2562, trigger time 3 heartbeats, T2 preparation duration TET2 Prep = 60/30/0 ms) was applied to obtain 3 short-axis T2 maps (van Heeswijk et al., JACCCardiovascImaging2012), which were segmented according to AHA guidelines (Cerqueira et al, Circulation2001). The highest segmental T2 values were grouped according to histological rejection grade and differences were analyzed by Student's t-test, except for the non-blinded cases with 2R rejection. The degree of discrimination was determined using the Spearman's ranked correlation test. Results: The high-quality T2 maps allowed for visual differentiation of the rejection degrees (Figure 1), and the correlation of T2 mapping with the histological grade of acute cellular rejection was significant (Spearman's r = 0.56, p = 0.007). The 0R (n = 15) and 1R (n = 3) degrees demonstrated significantly different T2 values (46.9 ± 5.0 and 54.3 ± 3.0 ms, p = 0.02, Figure 2). Cases with 2R rejection showed clear T2 elevation (T2 = 60.3 ± 16.2 ms). Conclusions: This pilot study demonstrates that non-invasive free-breathing cardiac T2 mapping at 3T discriminates between no and mild cardiac allograft rejection. Confirmation of these encouraging results in a larger cohort should consider a study able to show equivalency or superiority of T2 mapping.

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PURPOSE: To determine whether a mono-, bi- or tri-exponential model best fits the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) signal of normal livers. MATERIALS AND METHODS: The pilot and validation studies were conducted in 38 and 36 patients with normal livers, respectively. The DWI sequence was performed using single-shot echoplanar imaging with 11 (pilot study) and 16 (validation study) b values. In each study, data from all patients were used to model the IVIM signal of normal liver. Diffusion coefficients (Di ± standard deviations) and their fractions (fi ± standard deviations) were determined from each model. The models were compared using the extra sum-of-squares test and information criteria. RESULTS: The tri-exponential model provided a better fit than both the bi- and mono-exponential models. The tri-exponential IVIM model determined three diffusion compartments: a slow (D1 = 1.35 ± 0.03 × 10(-3) mm(2)/s; f1 = 72.7 ± 0.9 %), a fast (D2 = 26.50 ± 2.49 × 10(-3) mm(2)/s; f2 = 13.7 ± 0.6 %) and a very fast (D3 = 404.00 ± 43.7 × 10(-3) mm(2)/s; f3 = 13.5 ± 0.8 %) diffusion compartment [results from the validation study]. The very fast compartment contributed to the IVIM signal only for b values ≤15 s/mm(2) CONCLUSION: The tri-exponential model provided the best fit for IVIM signal decay in the liver over the 0-800 s/mm(2) range. In IVIM analysis of normal liver, a third very fast (pseudo)diffusion component might be relevant. KEY POINTS: ? For normal liver, tri-exponential IVIM model might be superior to bi-exponential ? A very fast compartment (D = 404.00 ± 43.7 × 10 (-3)  mm (2) /s; f = 13.5 ± 0.8 %) is determined from the tri-exponential model ? The compartment contributes to the IVIM signal only for b ≤ 15 s/mm (2.)

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1) Introduction: pour les jeunes souffrant de maladie chronique, l'objectif de la transition vers les soins pour adultes est d'optimiser leur fonctionnement et leur potentiel. Le but de cette étude pilote était d'évaluer si les jeunes adultes souffrant de maladie chronique jugeaient que le passage vers les soins adultes était plus facile lorsque la question de la transition avait été discutée au préalable avec leur pédiatre. 2) Matériel et méthodes: deux groupes de jeunes adultes atteints de maladie chronique ont été identifiés selon l'existence (n = 70) ou non (n = 22) d'une discussion préalable avec leur pédiatre à propos de la transition vers une prise en charge pour adultes. Ces deux groupes ont été comparés pour des variables démographiques et de santé. Les variables significatives en analyse bivariée ont été incluses dans une régression logistique descendante pas à pas. 3) Résultats: les jeunes adultes qui avaient discuté de la transition étaient significativement plus nombreux à se sentir prêts (72,9 % vs 45,5 %) et accompagnés (58,6 % vs 27,3 %) pour le transfert, à avoir consulté leur spécialiste pour adultes (60 % vs 31,8 %) et à voir leur médecin sans la présence de leurs parents (70 % vs 40,9 %). En analyse multivariée, seuls, le fait de se sentir accompagné (odds ratio ajustée [ORa] : 3,56) et celui d'avoir consulté leur spécialiste pour adultes (ORa : 4,14) étaient significatifs. 4) Conclusions: la préparation des jeunes souffrant de maladie chronique au transfert vers les soins pour adultes semble bénéfique. Cependant, le transfert lui-même n'est qu'une petite partie du concept beaucoup plus large de la transition vers la vie adulte. Une transition bien planifiée doit permettre à ces jeunes adultes d'atteindre tout leur potentiel. INTRODUCTION: The goal of transition in healthcare for young people with chronic illnesses is to maximize their functioning and potential. The purpose of this pilot study was to assess whether young adults with chronic illnesses found that the transition to adult care was easier when the transition was discussed in advance with their pediatric specialist. METHODS: Two groups were created according to whether patients had discussed (n=70) or not (n=22) the transition with their pediatric specialist and compared regarding demographic and health-related variables. All the significant variables at the bivariate level were included in a backward stepwise logistic regression. RESULTS: Youth who had discussed the transition were significantly more likely to feel ready for the transfer (72.9% vs 45.5%) and accompanied (58.6% vs 27. %) during transfer, to have consulted their specialist for adults (60.0% vs 31.8%), and seen their doctor without the presence of their parents (70.0% vs 40.9%). At the multivariate level, only feeling accompanied during transfer (adjusted odds ratio (aOR): 3.56) and having consulted their specialist for adults (aOR: 4.14) remained significant. CONCLUSIONS: Preparing chronically ill youths for transfer to adult care appears to be beneficial for them. However, transfer is only a small part of the much broader transition that is preparation for adult life. A well-planned transition should allow these young people to reach their full potential.

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Chronically homeless individuals with alcohol dependence experience severe alcohol-related consequences. It is therefore important to identify factors that might be associated with reduced alcohol-related harm, such as the use of safer-drinking strategies. Whereas effectiveness of safer-drinking strategies has been well-documented among young adults, no studies have explored this topic among more severely affected populations, such as chronically homeless individuals with alcohol dependence. The aims of this study were thus to qualitatively and quantitatively document safer-drinking strategies used in this population. Participants (N=31) were currently or formerly chronically homeless individuals with alcohol dependence participating in a pilot study of extended-release naltrexone and harm-reduction counseling. At weeks 0 and 8, research staff provided a list of safer-drinking strategies for participants to endorse. Implementation of endorsed safer-drinking strategies was recorded at the next appointment. At both time points, strategies to buffer the effects of alcohol on the body (e.g., eating prior to and during drinking) were most highly endorsed, followed by changing the manner in which one drinks (e.g., spacing drinks), and reducing alcohol consumption. Quantitative analyses indicated that all participants endorsed safer-drinking strategies, and nearly all strategies were implemented (80-90% at weeks 0 and 8, respectively). These preliminary findings indicate that chronically homeless people with alcohol dependence use strategies to reduce harm associated with their drinking. Larger randomized controlled trials are needed to test whether interventions that teach safer-drinking strategies may reduce overall alcohol-related harm in this population.

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Työn tavoitteena oli selvittää, miten kohdeyrityksen tulisi mitata suorituskykyään. Tutkielma toteutettiin toiminta-analyyttiseen lähestymistapaan kuuluvana toimintatutkimuksena. Kohdeyrityksestä valittiin yksi osasto, jolle suunniteltiin ja toteutettiin operatiivinen suorituskykymittaristo. Tämän projektin aikana pyrittiin keräämään kokemuksia, joista olisi hyötyä muiden osastojen ja koko yrityksen mittaristojen rakentamisessa.Työn teoriaosan alussa suorituskyvyn mittaus liitetään osaksi laajempaa johdon laskentatoimen käsitettä. Tämän jälkeen käsitellään tarkemmin mittariston rakentamisen teoriaa. Yksittäiset operatiiviset suorituskykymittarit johdetaan yrityksen strategiasta. Mittareiden välisten riippuvuussuhteiden esittäminen havainnollisesti helpottaa mittariston suunnittelua. Rajoituksia mittarivalinnoille asettavat yrityksen käytössä olevat tietojärjestelmät sekä henkilökunnan tottumukset kirjata työskentelyynsä liittyviä tietoja järjestelmiin.Tutkimuksen perusteella voidaan todeta, että mittariston suunnitteluryhmään tulisi valita toiminnan kehittämisestä kiinnostuneita henkilöitä. Resurssit on arvioitava huolella ja tarpeen vaatiessa voidaan turvautua ulkopuolisen suunnittelijan apuun. Eri osastojen ja koko yrityksen suorituskykymittaristojen rakentamista koordinoimaan tulee nimetä henkilö, joka varmistaa tiedonkulun eri suunnitteluryhmien välillä.

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BACKGROUND: To study the 'metabolic profile' of different surgical procedures and correlate it with pertinent surgical details and postoperative complications. METHODS: We conducted a prospective pilot study of 70 patients, ten for each of the seven following groups: (1) laparoscopic cholecystectomy, (2) incisional hernia repair, (3) laparoscopic and (4) open colon surgery, (5) upper gastrointestinal, (6) hepatic, and (7) pancreatic resections. Biochemical assessment included white blood cell count (WBC), C-reactive protein (CRP), glucose, triglycerides (TG), albumin (Alb), and pre-albumin (Pre-Alb), from the day before surgery until 5 days thereafter. Biological markers were compared for major versus minor surgery groups, which were defined on a clinical basis. Univariable analysis was used to identify risk factors for postoperative complications and p < 0.05 was the significance threshold. RESULTS: Common findings in all surgery groups were the acute inflammatory response (↑: WBC, CRP, ↓: TG, Alb, pre-Alb). Using cut-off values of 240 min operative (OR) time and 300 ml estimated blood loss (EBL), laparoscopic cholecystectomy, incisional hernia repair, and laparoscopic colectomy could be distinguished from open colectomy, upper gastrointestinal, liver, and pancreas resections. In a biochemical level, increased CRP and reduced postoperative Alb levels were highly discriminative of all types of 'major surgery.' Significant risk factors for postoperative complications were age, male gender, malignancy, longer OR time, higher blood loss, high CRP, and low Alb levels. CONCLUSIONS: Biochemically, CRP and Alb levels can help quantify the magnitude of the surgical trauma, which is correlated with adverse outcomes.

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«Quel est l'âge de cette trace digitale?» Cette question est relativement souvent soulevée au tribunal ou lors d'investigations, lorsque la personne suspectée admet avoir laissé ses empreintes digitales sur une scène de crime mais prétend l'avoir fait à un autre moment que celui du crime et pour une raison innocente. Toutefois, aucune réponse ne peut actuellement être donnée à cette question, puisqu'aucune méthodologie n'est pour l'heure validée et acceptée par l'ensemble de la communauté forensique. Néanmoins, l'inventaire de cas américains conduit dans cette recherche a montré que les experts fournissent tout de même des témoignages au tribunal concernant l'âge de traces digitales, même si ceux-­‐ci sont majoritairement basés sur des paramètres subjectifs et mal documentés. Il a été relativement aisé d'accéder à des cas américains détaillés, ce qui explique le choix de l'exemple. Toutefois, la problématique de la datation des traces digitales est rencontrée dans le monde entier, et le manque de consensus actuel dans les réponses données souligne la nécessité d'effectuer des études sur le sujet. Le but de la présente recherche est donc d'évaluer la possibilité de développer une méthode de datation objective des traces digitales. Comme les questions entourant la mise au point d'une telle procédure ne sont pas nouvelles, différentes tentatives ont déjà été décrites dans la littérature. Cette recherche les a étudiées de manière critique, et souligne que la plupart des méthodologies reportées souffrent de limitations prévenant leur utilisation pratique. Néanmoins, certaines approches basées sur l'évolution dans le temps de composés intrinsèques aux résidus papillaires se sont montrées prometteuses. Ainsi, un recensement détaillé de la littérature a été conduit afin d'identifier les composés présents dans les traces digitales et les techniques analytiques capables de les détecter. Le choix a été fait de se concentrer sur les composés sébacés détectés par chromatographie gazeuse couplée à la spectrométrie de masse (GC/MS) ou par spectroscopie infrarouge à transformée de Fourier. Des analyses GC/MS ont été menées afin de caractériser la variabilité initiale de lipides cibles au sein des traces digitales d'un même donneur (intra-­‐variabilité) et entre les traces digitales de donneurs différents (inter-­‐variabilité). Ainsi, plusieurs molécules ont été identifiées et quantifiées pour la première fois dans les résidus papillaires. De plus, il a été déterminé que l'intra-­‐variabilité des résidus était significativement plus basse que l'inter-­‐variabilité, mais que ces deux types de variabilité pouvaient être réduits en utilisant différents pré-­‐ traitements statistiques s'inspirant du domaine du profilage de produits stupéfiants. Il a également été possible de proposer un modèle objectif de classification des donneurs permettant de les regrouper dans deux classes principales en se basant sur la composition initiale de leurs traces digitales. Ces classes correspondent à ce qui est actuellement appelé de manière relativement subjective des « bons » ou « mauvais » donneurs. Le potentiel d'un tel modèle est élevé dans le domaine de la recherche en traces digitales, puisqu'il permet de sélectionner des donneurs représentatifs selon les composés d'intérêt. En utilisant la GC/MS et la FTIR, une étude détaillée a été conduite sur les effets de différents facteurs d'influence sur la composition initiale et le vieillissement de molécules lipidiques au sein des traces digitales. Il a ainsi été déterminé que des modèles univariés et multivariés pouvaient être construits pour décrire le vieillissement des composés cibles (transformés en paramètres de vieillissement par pré-­‐traitement), mais que certains facteurs d'influence affectaient ces modèles plus sérieusement que d'autres. En effet, le donneur, le substrat et l'application de techniques de révélation semblent empêcher la construction de modèles reproductibles. Les autres facteurs testés (moment de déposition, pression, température et illumination) influencent également les résidus et leur vieillissement, mais des modèles combinant différentes valeurs de ces facteurs ont tout de même prouvé leur robustesse dans des situations bien définies. De plus, des traces digitales-­‐tests ont été analysées par GC/MS afin d'être datées en utilisant certains des modèles construits. Il s'est avéré que des estimations correctes étaient obtenues pour plus de 60 % des traces-­‐tests datées, et jusqu'à 100% lorsque les conditions de stockage étaient connues. Ces résultats sont intéressants mais il est impératif de conduire des recherches supplémentaires afin d'évaluer les possibilités d'application de ces modèles dans des cas réels. Dans une perspective plus fondamentale, une étude pilote a également été effectuée sur l'utilisation de la spectroscopie infrarouge combinée à l'imagerie chimique (FTIR-­‐CI) afin d'obtenir des informations quant à la composition et au vieillissement des traces digitales. Plus précisément, la capacité de cette technique à mettre en évidence le vieillissement et l'effet de certains facteurs d'influence sur de larges zones de traces digitales a été investiguée. Cette information a ensuite été comparée avec celle obtenue par les spectres FTIR simples. Il en a ainsi résulté que la FTIR-­‐CI était un outil puissant, mais que son utilisation dans l'étude des résidus papillaires à des buts forensiques avait des limites. En effet, dans cette recherche, cette technique n'a pas permis d'obtenir des informations supplémentaires par rapport aux spectres FTIR traditionnels et a également montré des désavantages majeurs, à savoir de longs temps d'analyse et de traitement, particulièrement lorsque de larges zones de traces digitales doivent être couvertes. Finalement, les résultats obtenus dans ce travail ont permis la proposition et discussion d'une approche pragmatique afin d'aborder les questions de datation des traces digitales. Cette approche permet ainsi d'identifier quel type d'information le scientifique serait capable d'apporter aux enquêteurs et/ou au tribunal à l'heure actuelle. De plus, le canevas proposé décrit également les différentes étapes itératives de développement qui devraient être suivies par la recherche afin de parvenir à la validation d'une méthodologie de datation des traces digitales objective, dont les capacités et limites sont connues et documentées. -- "How old is this fingermark?" This question is relatively often raised in trials when suspects admit that they have left their fingermarks on a crime scene but allege that the contact occurred at a time different to that of the crime and for legitimate reasons. However, no answer can be given to this question so far, because no fingermark dating methodology has been validated and accepted by the whole forensic community. Nevertheless, the review of past American cases highlighted that experts actually gave/give testimonies in courts about the age of fingermarks, even if mostly based on subjective and badly documented parameters. It was relatively easy to access fully described American cases, thus explaining the origin of the given examples. However, fingermark dating issues are encountered worldwide, and the lack of consensus among the given answers highlights the necessity to conduct research on the subject. The present work thus aims at studying the possibility to develop an objective fingermark dating method. As the questions surrounding the development of dating procedures are not new, different attempts were already described in the literature. This research proposes a critical review of these attempts and highlights that most of the reported methodologies still suffer from limitations preventing their use in actual practice. Nevertheless, some approaches based on the evolution of intrinsic compounds detected in fingermark residue over time appear to be promising. Thus, an exhaustive review of the literature was conducted in order to identify the compounds available in the fingermark residue and the analytical techniques capable of analysing them. It was chosen to concentrate on sebaceous compounds analysed using gas chromatography coupled with mass spectrometry (GC/MS) or Fourier transform infrared spectroscopy (FTIR). GC/MS analyses were conducted in order to characterize the initial variability of target lipids among fresh fingermarks of the same donor (intra-­‐variability) and between fingermarks of different donors (inter-­‐variability). As a result, many molecules were identified and quantified for the first time in fingermark residue. Furthermore, it was determined that the intra-­‐variability of the fingermark residue was significantly lower than the inter-­‐variability, but that it was possible to reduce both kind of variability using different statistical pre-­‐ treatments inspired from the drug profiling area. It was also possible to propose an objective donor classification model allowing the grouping of donors in two main classes based on their initial lipid composition. These classes correspond to what is relatively subjectively called "good" or "bad" donors. The potential of such a model is high for the fingermark research field, as it allows the selection of representative donors based on compounds of interest. Using GC/MS and FTIR, an in-­‐depth study of the effects of different influence factors on the initial composition and aging of target lipid molecules found in fingermark residue was conducted. It was determined that univariate and multivariate models could be build to describe the aging of target compounds (transformed in aging parameters through pre-­‐ processing techniques), but that some influence factors were affecting these models more than others. In fact, the donor, the substrate and the application of enhancement techniques seemed to hinder the construction of reproducible models. The other tested factors (deposition moment, pressure, temperature and illumination) also affected the residue and their aging, but models combining different values of these factors still proved to be robust. Furthermore, test-­‐fingermarks were analysed with GC/MS in order to be dated using some of the generated models. It turned out that correct estimations were obtained for 60% of the dated test-­‐fingermarks and until 100% when the storage conditions were known. These results are interesting but further research should be conducted to evaluate if these models could be used in uncontrolled casework conditions. In a more fundamental perspective, a pilot study was also conducted on the use of infrared spectroscopy combined with chemical imaging in order to gain information about the fingermark composition and aging. More precisely, its ability to highlight influence factors and aging effects over large areas of fingermarks was investigated. This information was then compared with that given by individual FTIR spectra. It was concluded that while FTIR-­‐ CI is a powerful tool, its use to study natural fingermark residue for forensic purposes has to be carefully considered. In fact, in this study, this technique does not yield more information on residue distribution than traditional FTIR spectra and also suffers from major drawbacks, such as long analysis and processing time, particularly when large fingermark areas need to be covered. Finally, the results obtained in this research allowed the proposition and discussion of a formal and pragmatic framework to approach the fingermark dating questions. It allows identifying which type of information the scientist would be able to bring so far to investigators and/or Justice. Furthermore, this proposed framework also describes the different iterative development steps that the research should follow in order to achieve the validation of an objective fingermark dating methodology, whose capacities and limits are well known and properly documented.

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INTRODUCTION: Electroencephalogram (EEG) background reactivity is a potentially interesting outcome predictor in comatose patients, especially after cardiac arrest, but recent studies report only fair interrater reliability. Furthermore, there are no definite guidelines for its testing. We therefore investigated the EEG effect of standardized noxious stimuli in comatose patients not reactive to auditory stimuli. METHODS: In this prospective study we applied a protocol using three different painful stimuli (bilateral nipple pinching, pinprick at the nose base, finger-nail compression on each side), grouped in three distinct clusters with an alternated sequence, during EEG recordings in comatose patients. We only analyzed recordings showing any reactivity to pain. Fisher and χ2 tests were used as needed to assess contingency tables. RESULTS: Of 42 studies, 12 did not show any background reactivity, 2 presented SIRPIDs, and 2 had massive artefacts; we thus analyzed 26 EEGs recorded in 17 patients (4 women, 24%). Nipple pinching more frequently induced a change in EEG background activity (p<0.001), with a sensitivity of 97.4% for reactivity. Neither the order of the stimuli in the cluster (p=0.723), nor the cluster order (p=0.901) influenced the results. CONCLUSION: In this pilot study, bilateral, synchronous nipple pinching seems to be the most efficient method to test nociceptive EEG reactivity in comatose patients. This approach may enhance interrater reliability, but deserves confirmation in larger cohorts.

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Human biomonitoring (HBM) is an effective tool for assessing actual exposure to chemicals that takes into account all routes of intake. Although hair analysis is considered to be an optimal biomarker for assessing mercury exposure, the lack of harmonization as regards sampling and analytical procedures has often limited the comparison of data at national and international level. The European-funded projects COPHES and DEMOCOPHES developed and tested a harmonized European approach to Human Biomonitoring in response to the European Environment and Health Action Plan. Herein we describe the quality assurance program (QAP) for assessing mercury levels in hair samples from more than 1800 mother-child pairs recruited in 17 European countries. To ensure the comparability of the results, standard operating procedures (SOPs) for sampling and for mercury analysis were drafted and distributed to participating laboratories. Training sessions were organized for field workers and four external quality-assessment exercises (ICI/EQUAS), followed by the corresponding web conferences, were organized between March 2011 and February 2012. ICI/EQUAS used native hair samples at two mercury concentration ranges (0.20-0.71 and 0.80-1.63) per exercise. The results revealed relative standard deviations of 7.87-13.55% and 4.04-11.31% for the low and high mercury concentration ranges, respectively. A total of 16 out of 18 participating laboratories the QAP requirements and were allowed to analyze samples from the DEMOCOPHES pilot study. Web conferences after each ICI/EQUAS revealed this to be a new and effective tool for improving analytical performance and increasing capacity building. The procedure developed and tested in COPHES/DEMOCOPHES would be optimal for application on a global scale as regards implementation of the Minamata Convention on Mercury.

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The birth of a preterm infant is in most cases unexpected and can be a distressing experience for parents. Parents of premature babies report more stress, experience more adjustment difficulties and need for support during the first year after delivery compared to parents of infants born at term. It has been documented that parents may experience posttraumatic stress reactions, anxiety and depression following the premature birth of their baby, which subsequently may impact on the mother-baby-interactions, their attachment relationship and the cognitive, social and behavioural development of the baby. In this pilot study, we offered an expressive writing intervention to women who recently had a premature baby to alleviate their psychological distress and to improve their physical health. During the expressive writing intervention, women were asked to write down their deepest thoughts and feelings about the most traumatic aspect of their experience of having a premature baby for 15 min over three consecutive days. The aims of the study were as follows: (1) To evaluate the effect of expressive writing on psychological and physical health in women who recently had a premature baby. (2) To evaluate the effect of expressive writing on the use of healthcare services and medication in this population. (3) To evaluate the acceptability and feasibility of this intervention for this population. Forty participants were randomly allocated to either the expressive writing intervention group or a wait list control group. Pre- and post questionnaires to evaluate the effectiveness of the expressive writing intervention, as well as their acceptability and feasibility were completed. The intervention took place when the baby was 3 months of corrected age. Post-measures were completed at 1 and 3 months following the intervention. Results and their clinical implications will be discussed with regards to the implementation of this safe and cost-effective method as a preventative measure in the routine care of women who recently gave birth to a premature baby

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PURPOSE: To compare the effects of converting to aflibercept therapy with continuing ranibizumab therapy in eyes with neovascular age-related macular degeneration requiring monthly ranibizumab treatment. METHODS: Patients were selected from the 104 patients (115 eyes) already enrolled in an "Observe and Plan" prospective case series that included treating neovascular age-related macular degeneration with ranibizumab for 24 months. Patients who still needed monthly retreatment at the end of a 2-year study were randomized to either continue ranibizumab therapy or to convert to aflibercept therapy. Outcome measures included average interval between treatments, resolution of exudative signs, number of retreatments, and change in visual acuity over 12 months (the third treatment year). RESULTS: Nineteen patients (21 eyes) met the inclusion criteria. Ten eyes were randomized to receive aflibercept, and 11 eyes remained on ranibizumab. Groups were balanced for baseline characteristics. Outcomes were similar in the 2 groups over a 12-month study duration, with no statistical difference. CONCLUSION: This comparative pilot study suggests that neovascular age-related macular degeneration requiring monthly retreatment with ranibizumab may respond in similar ways to both ranibizumab and aflibercept treatment. Larger sample sizes would be needed to confirm this observation.

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Understanding and quantifying seismic energy dissipation, which manifests itself in terms of velocity dispersion and attenuation, in fluid-saturated porous rocks is of considerable interest, since it offers the perspective of extracting information with regard to the elastic and hydraulic rock properties. There is increasing evidence to suggest that wave-induced fluid flow, or simply WIFF, is the dominant underlying physical mechanism governing these phenomena throughout the seismic, sonic, and ultrasonic frequency ranges. This mechanism, which can prevail at the microscopic, mesoscopic, and macroscopic scale ranges, operates through viscous energy dissipation in response to fluid pressure gradients and inertial effects induced by the passing wavefield. In the first part of this thesis, we present an analysis of broad-band multi-frequency sonic log data from a borehole penetrating water-saturated unconsolidated glacio-fluvial sediments. An inherent complication arising in the interpretation of the observed P-wave attenuation and velocity dispersion is, however, that the relative importance of WIFF at the various scales is unknown and difficult to unravel. An important generic result of our work is that the levels of attenuation and velocity dispersion due to the presence of mesoscopic heterogeneities in water-saturated unconsolidated clastic sediments are expected to be largely negligible. Conversely, WIFF at the macroscopic scale allows for explaining most of the considered data while refinements provided by including WIFF at the microscopic scale in the analysis are locally meaningful. Using a Monte-Carlo-type inversion approach, we compare the capability of the different models describing WIFF at the macroscopic and microscopic scales with regard to their ability to constrain the dry frame elastic moduli and the permeability as well as their local probability distribution. In the second part of this thesis, we explore the issue of determining the size of a representative elementary volume (REV) arising in the numerical upscaling procedures of effective seismic velocity dispersion and attenuation of heterogeneous media. To this end, we focus on a set of idealized synthetic rock samples characterized by the presence of layers, fractures or patchy saturation in the mesocopic scale range. These scenarios are highly pertinent because they tend to be associated with very high levels of velocity dispersion and attenuation caused by WIFF in the mesoscopic scale range. The problem of determining the REV size for generic heterogeneous rocks is extremely complex and entirely unexplored in the given context. In this pilot study, we have therefore focused on periodic media, which assures the inherent self- similarity of the considered samples regardless of their size and thus simplifies the problem to a systematic analysis of the dependence of the REV size on the applied boundary conditions in the numerical simulations. Our results demonstrate that boundary condition effects are absent for layered media and negligible in the presence of patchy saturation, thus resulting in minimum REV sizes. Conversely, strong boundary condition effects arise in the presence of a periodic distribution of finite-length fractures, thus leading to large REV sizes. In the third part of the thesis, we propose a novel effective poroelastic model for periodic media characterized by mesoscopic layering, which accounts for WIFF at both the macroscopic and mesoscopic scales as well as for the anisotropy associated with the layering. Correspondingly, this model correctly predicts the existence of the fast and slow P-waves as well as quasi and pure S-waves for any direction of wave propagation as long as the corresponding wavelengths are much larger than the layer thicknesses. The primary motivation for this work is that, for formations of intermediate to high permeability, such as, for example, unconsolidated sediments, clean sandstones, or fractured rocks, these two WIFF mechanisms may prevail at similar frequencies. This scenario, which can be expected rather common, cannot be accounted for by existing models for layered porous media. Comparisons of analytical solutions of the P- and S-wave phase velocities and inverse quality factors for wave propagation perpendicular to the layering with those obtained from numerical simulations based on a ID finite-element solution of the poroelastic equations of motion show very good agreement as long as the assumption of long wavelengths remains valid. A limitation of the proposed model is its inability to account for inertial effects in mesoscopic WIFF when both WIFF mechanisms prevail at similar frequencies. Our results do, however, also indicate that the associated error is likely to be relatively small, as, even at frequencies at which both inertial and scattering effects are expected to be at play, the proposed model provides a solution that is remarkably close to its numerical benchmark. -- Comprendre et pouvoir quantifier la dissipation d'énergie sismique qui se traduit par la dispersion et l'atténuation des vitesses dans les roches poreuses et saturées en fluide est un intérêt primordial pour obtenir des informations à propos des propriétés élastique et hydraulique des roches en question. De plus en plus d'études montrent que le déplacement relatif du fluide par rapport au solide induit par le passage de l'onde (wave induced fluid flow en anglais, dont on gardera ici l'abréviation largement utilisée, WIFF), représente le principal mécanisme physique qui régit ces phénomènes, pour la gamme des fréquences sismiques, sonique et jusqu'à l'ultrasonique. Ce mécanisme, qui prédomine aux échelles microscopique, mésoscopique et macroscopique, est lié à la dissipation d'énergie visqueuse résultant des gradients de pression de fluide et des effets inertiels induits par le passage du champ d'onde. Dans la première partie de cette thèse, nous présentons une analyse de données de diagraphie acoustique à large bande et multifréquences, issues d'un forage réalisé dans des sédiments glaciaux-fluviaux, non-consolidés et saturés en eau. La difficulté inhérente à l'interprétation de l'atténuation et de la dispersion des vitesses des ondes P observées, est que l'importance des WIFF aux différentes échelles est inconnue et difficile à quantifier. Notre étude montre que l'on peut négliger le taux d'atténuation et de dispersion des vitesses dû à la présence d'hétérogénéités à l'échelle mésoscopique dans des sédiments clastiques, non- consolidés et saturés en eau. A l'inverse, les WIFF à l'échelle macroscopique expliquent la plupart des données, tandis que les précisions apportées par les WIFF à l'échelle microscopique sont localement significatives. En utilisant une méthode d'inversion du type Monte-Carlo, nous avons comparé, pour les deux modèles WIFF aux échelles macroscopique et microscopique, leur capacité à contraindre les modules élastiques de la matrice sèche et la perméabilité ainsi que leur distribution de probabilité locale. Dans une seconde partie de cette thèse, nous cherchons une solution pour déterminer la dimension d'un volume élémentaire représentatif (noté VER). Cette problématique se pose dans les procédures numériques de changement d'échelle pour déterminer l'atténuation effective et la dispersion effective de la vitesse sismique dans un milieu hétérogène. Pour ce faire, nous nous concentrons sur un ensemble d'échantillons de roches synthétiques idéalisés incluant des strates, des fissures, ou une saturation partielle à l'échelle mésoscopique. Ces scénarios sont hautement pertinents, car ils sont associés à un taux très élevé d'atténuation et de dispersion des vitesses causé par les WIFF à l'échelle mésoscopique. L'enjeu de déterminer la dimension d'un VER pour une roche hétérogène est très complexe et encore inexploré dans le contexte actuel. Dans cette étude-pilote, nous nous focalisons sur des milieux périodiques, qui assurent l'autosimilarité des échantillons considérés indépendamment de leur taille. Ainsi, nous simplifions le problème à une analyse systématique de la dépendance de la dimension des VER aux conditions aux limites appliquées. Nos résultats indiquent que les effets des conditions aux limites sont absents pour un milieu stratifié, et négligeables pour un milieu à saturation partielle : cela résultant à des dimensions petites des VER. Au contraire, de forts effets des conditions aux limites apparaissent dans les milieux présentant une distribution périodique de fissures de taille finie : cela conduisant à de grandes dimensions des VER. Dans la troisième partie de cette thèse, nous proposons un nouveau modèle poro- élastique effectif, pour les milieux périodiques caractérisés par une stratification mésoscopique, qui prendra en compte les WIFF à la fois aux échelles mésoscopique et macroscopique, ainsi que l'anisotropie associée à ces strates. Ce modèle prédit alors avec exactitude l'existence des ondes P rapides et lentes ainsi que les quasis et pures ondes S, pour toutes les directions de propagation de l'onde, tant que la longueur d'onde correspondante est bien plus grande que l'épaisseur de la strate. L'intérêt principal de ce travail est que, pour les formations à perméabilité moyenne à élevée, comme, par exemple, les sédiments non- consolidés, les grès ou encore les roches fissurées, ces deux mécanismes d'WIFF peuvent avoir lieu à des fréquences similaires. Or, ce scénario, qui est assez commun, n'est pas décrit par les modèles existants pour les milieux poreux stratifiés. Les comparaisons des solutions analytiques des vitesses des ondes P et S et de l'atténuation de la propagation des ondes perpendiculaires à la stratification, avec les solutions obtenues à partir de simulations numériques en éléments finis, fondées sur une solution obtenue en 1D des équations poro- élastiques, montrent un très bon accord, tant que l'hypothèse des grandes longueurs d'onde reste valable. Il y a cependant une limitation de ce modèle qui est liée à son incapacité à prendre en compte les effets inertiels dans les WIFF mésoscopiques quand les deux mécanismes d'WIFF prédominent à des fréquences similaires. Néanmoins, nos résultats montrent aussi que l'erreur associée est relativement faible, même à des fréquences à laquelle sont attendus les deux effets d'inertie et de diffusion, indiquant que le modèle proposé fournit une solution qui est remarquablement proche de sa référence numérique.

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Background: Chronic liver diseases (CLDs) are significant causes of death in adults in many countries and are usually diagnosed at late stages. Early detection may allow time for treatment to prevent disease progression. Objectives: The aim of this study was to assess the feasibility of screening for unrecognized CLDs in a primary care nurse consultancy and report findings from screening. Methods: Two experienced nurses in a primary care nurse consultancy were trained to perform transient elastography (TE). Subjects aged from 18 to 70 years were identified randomly from the health registry and invited to participate in a feasibility pilot study. Exclusion criteria were past or current history of liver diseases. Nurses collected demographic and clinical data and performed TE tests using Fibroscan tomeasure liver stiffness; a cutoff score of 6.8 kPa or greater was used as an indicator of the presence of CLD with fibrosis. Results: Accurate measurements were obtained in 495 of 502 participants (98.6%). Prevalence of elevated liver stiffness was observed in 28 of 495 subjects (5.7%). Compared to patients with normal liver stiffness, patients with increased liver stiffness were older, were more frequently male, and had higher frequency of metabolic syndrome. Nonalcoholic fatty liver was the most common cause of CLD. Discussion: Following training in procedures for conducting TE, nurses in a primary care clinic were able to detect unrecognized CLDs in presumably healthy subjects. Early detection of CLDs is feasible in primary care clinics and may facilitate identification of undiagnosed CLD in adults.

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La publicación de artículos científicos que tratan los trastornos del comportamiento alimentario (TCA) se ha incrementado en los últimos años y han experimentado un aumento significativo que puede ser atribuido a diferentes factores, entre ellos el surgimiento de nuevas publicaciones más selectivas y especializadas. La creciente investigación examina las preocupaciones de la imagen corporal y otras conductas asociadas, además de realizar investigaciones con diversos grupos poblacionales que incluyen a hispanos, asiáticos, europeos, etc. Este trabajo, muestra una revisión realizada a 136 artículos publicados en 67 revistas de ámbito internacional. Los artículos comprenden una selección realizada entre el año 2004 y el año 2008, como fruto de una revisión bibliográfica que sirvió de base para el desarro-llo del proyecto I+D denominado “La Publicidad de TV entre otros factores socioculturales influyentes en los TCA, estudio experimental y panel de expertos internacional” (2006-2010), proyecto del cual las autoras forman parte. En el artículo se concluye que existe una amplia tendencia a examinar los medios de comunicación y su influencia en los TCA y que las muestras tienden a utilizar a mujeres en su mayoría jóvenes, las cuales presentan un mayor grado de incidencia hacia los trastornos alimentarios que los hombres jóvenes. Se observó además que los investigadores detectan la sintomatología en grupos con una edad cada vez menor.