Liver segmentation: Practical tips.

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Mandatory communication skills training for oncologists: enforcement does not substantially impact satisfaction.

PURPOSE: Even though there is evidence that both patients and oncology clinicians are affected by the quality of communication and that communication skills can be effectively trained, so-called Communication Skills Trainings (CSTs) remain heterogeneously implemented. METHODS: A systematic evaluation of the level of satisfaction of oncologists with the Swiss CST before (2000-2005) and after (2006-2012) it became mandatory. RESULTS: Levels of satisfaction with the CST were high, and satisfaction of physicians participating on a voluntary or mandatory basis did not significantly differ for the majority of the items. CONCLUSIONS: The evaluation of physicians' satisfaction over the years and after introduction of mandatory training supports recommendations for generalized implementation of CST and mandatory training for medical oncologists.

Training in flexible intensive insulin therapy improves quality of life, decreases the risk of hypoglycaemia and ameliorates poor metabolic control in patients with type 1 diabetes.

AIM: Intensified insulin therapy has evolved to be the standard treatment of type 1 diabetes. However, it has been reported to increase significantly the risk of hypoglycaemia. We studied the effect of structured group teaching courses in flexible insulin therapy (FIT) on psychological and metabolic parameters in patients with type 1 diabetes. METHODS: We prospectively followed 45 type 1 diabetic patients of our outpatient clinic participating in 5 consecutive FIT teaching courses at the University Hospital of Basel. These courses consist of 7 weekly ambulatory evening group sessions. Patients were studied before and 1, 6, and 18 months after the course. Main outcome measures were glycated haemoglobin (HbA1c), severe hypoglycaemic events, quality of life (DQoL), diabetes self-control (IPC-9) and diabetes knowledge (DWT). RESULTS: Quality of life, self-control and diabetes knowledge improved after the FIT courses (all p<0.001). The frequency of severe hypoglycaemic events decreased ten-fold from 0.33 episodes/6 months at baseline to 0.03 episodes/6 months after 18 months (p<0.05). Baseline HbA1c was 7.2+/-1.1% and decreased in the subgroup with HbA1c > or = 8% from 8.4% to 7.8% (p<0.05). CONCLUSIONS: In an unselected, but relatively well-controlled population of type 1 diabetes, a structured, but not very time consuming FIT teaching programme in the outpatient setting improves psychological well-being and metabolic parameters.

Spaced training facilitates long-term retention of place navigation in adult but not in adolescent rats

Young and adult Long Evans rats were tested in the water maze according to two different procedures: half of the subjects were given one session of four trials a day for 6 days, whereas the other subjects had the same amount of training massed in 1 day. For both conditions, a 14-day retention interval was then introduced to test long-term memory. This was followed by a four-trial reversal session. All groups showed a significant learning curve, but escape latencies were shorter for the adult than for the young rats, without differential effect of the training procedure. A first probe trial (PT1) confirmed similar accurate short-term retention in all the groups. But unimpaired long-term memory was only seen in the adult rats trained with the spaced procedure. The young rats trained over 1 day also showed some retention of the platform location after 14 days, but not the other two groups. Reversal acquisition of the new platform location was rapid in the four groups. These results indicate that although accurate short-term spatial memory in the water maze is seen after a 1-day massed training in both age groups, unimpaired long-term retention is only observed in adult rats trained with 24-h inter-session intervals.

Access to a simulator is not enough: the benefits of virtual reality training based on peer-group-derived benchmarks--a randomized controlled trial.

BACKGROUND: Virtual reality (VR) simulators are widely used to familiarize surgical novices with laparoscopy, but VR training methods differ in efficacy. In the present trial, self-controlled basic VR training (SC-training) was tested against training based on peer-group-derived benchmarks (PGD-training). METHODS: First, novice laparoscopic residents were randomized into a SC group (n = 34), and a group using PGD-benchmarks (n = 34) for basic laparoscopic training. After completing basic training, both groups performed 60 VR laparoscopic cholecystectomies for performance analysis. Primary endpoints were simulator metrics; secondary endpoints were program adherence, trainee motivation, and training efficacy. RESULTS: Altogether, 66 residents completed basic training, and 3,837 of 3,960 (96.8 %) cholecystectomies were available for analysis. Course adherence was good, with only two dropouts, both in the SC-group. The PGD-group spent more time and repetitions in basic training until the benchmarks were reached and subsequently showed better performance in the readout cholecystectomies: Median time (gallbladder extraction) showed significant differences of 520 s (IQR 354-738 s) in SC-training versus 390 s (IQR 278-536 s) in the PGD-group (p < 0.001) and 215 s (IQR 175-276 s) in experts, respectively. Path length of the right instrument also showed significant differences, again with the PGD-training group being more efficient. CONCLUSIONS: Basic VR laparoscopic training based on PGD benchmarks with external assessment is superior to SC training, resulting in higher trainee motivation and better performance in simulated laparoscopic cholecystectomies. We recommend such a basic course based on PGD benchmarks before advancing to more elaborate VR training.

Unfolding nature "in silico" : overcoming practical and metodological limitations of species distribution models

Abstract : The existence of a causal relationship between the spatial distribution of living organisms and their environment, in particular climate, has been long recognized and is the central principle of biogeography. In turn, this recognition has led scientists to the idea of using the climatic, topographic, edaphic and biotic characteristics of the environment to predict its potential suitability for a given species or biological community. In this thesis, my objective is to contribute to the development of methodological improvements in the field of species distribution modeling. More precisely, the objectives are to propose solutions to overcome limitations of species distribution models when applied to conservation biology issues, or when .used as an assessment tool of the potential impacts of global change. The first objective of my thesis is to contribute to evidence the potential of species distribution models for conservation-related applications. I present a methodology to generate pseudo-absences in order to overcome the frequent lack of reliable absence data. I also demonstrate, both theoretically (simulation-based) and practically (field-based), how species distribution models can be successfully used to model and sample rare species. Overall, the results of this first part of the thesis demonstrate the strong potential of species distribution models as a tool for practical applications in conservation biology. The second objective this thesis is to contribute to improve .projections of potential climate change impacts on species distributions, and in particular for mountain flora. I develop and a dynamic model, MIGCLIM, that allows the implementation of dispersal limitations into classic species distribution models and present an application of this model to two virtual species. Given that accounting for dispersal limitations requires information on seed dispersal, distances, a general methodology to classify species into broad dispersal types is also developed. Finally, the M~GCLIM model is applied to a large number of species in a study area of the western Swiss Alps. Overall, the results indicate that while dispersal limitations can have an important impact on the outcome of future projections of species distributions under climate change scenarios, estimating species threat levels (e.g. species extinction rates) for a mountainous areas of limited size (i.e. regional scale) can also be successfully achieved when considering dispersal as unlimited (i.e. ignoring dispersal limitations, which is easier from a practical point of view). Finally, I present the largest fine scale assessment of potential climate change impacts on mountain vegetation that has been carried-out to date. This assessment involves vegetation from 12 study areas distributed across all major western and central European mountain ranges. The results highlight that some mountain ranges (the Pyrenees and the Austrian Alps) are expected to be more affected by climate change than others (Norway and the Scottish Highlands). The results I obtain in this study also indicate that the threat levels projected by fine scale models are less severe than those derived from coarse scale models. This result suggests that some species could persist in small refugias that are not detected by coarse scale models. Résumé : L'existence d'une relation causale entre la répartition des espèces animales et végétales et leur environnement, en particulier le climat, a été mis en évidence depuis longtemps et est un des principes centraux en biogéographie. Ce lien a naturellement conduit à l'idée d'utiliser les caractéristiques climatiques, topographiques, édaphiques et biotiques de l'environnement afin d'en prédire la qualité pour une espèce ou une communauté. Dans ce travail de thèse, mon objectif est de contribuer au développement d'améliorations méthodologiques dans le domaine de la modélisation de la distribution d'espèces dans le paysage. Plus précisément, les objectifs sont de proposer des solutions afin de surmonter certaines limitations des modèles de distribution d'espèces dans des applications pratiques de biologie de la conservation ou dans leur utilisation pour évaluer l'impact potentiel des changements climatiques sur l'environnement. Le premier objectif majeur de mon travail est de contribuer à démontrer le potentiel des modèles de distribution d'espèces pour des applications pratiques en biologie de la conservation. Je propose une méthode pour générer des pseudo-absences qui permet de surmonter le problème récurent du manque de données d'absences fiables. Je démontre aussi, de manière théorique (par simulation) et pratique (par échantillonnage de terrain), comment les modèles de distribution d'espèces peuvent être utilisés pour modéliser et améliorer l'échantillonnage des espèces rares. Ces résultats démontrent le potentiel des modèles de distribution d'espèces comme outils pour des applications de biologie de la conservation. Le deuxième objectif majeur de ce travail est de contribuer à améliorer les projections d'impacts potentiels des changements climatiques sur la flore, en particulier dans les zones de montagnes. Je développe un modèle dynamique de distribution appelé MigClim qui permet de tenir compte des limitations de dispersion dans les projections futures de distribution potentielle d'espèces, et teste son application sur deux espèces virtuelles. Vu que le fait de prendre en compte les limitations dues à la dispersion demande des données supplémentaires importantes (p.ex. la distance de dispersion des graines), ce travail propose aussi une méthode de classification simplifiée des espèces végétales dans de grands "types de disperseurs", ce qui permet ainsi de d'obtenir de bonnes approximations de distances de dispersions pour un grand nombre d'espèces. Finalement, j'applique aussi le modèle MIGCLIM à un grand nombre d'espèces de plantes dans une zone d'études des pré-Alpes vaudoises. Les résultats montrent que les limitations de dispersion peuvent avoir un impact considérable sur la distribution potentielle d'espèces prédites sous des scénarios de changements climatiques. Cependant, quand les modèles sont utilisés pour évaluer les taux d'extinction d'espèces dans des zones de montages de taille limitée (évaluation régionale), il est aussi possible d'obtenir de bonnes approximations en considérant la dispersion des espèces comme illimitée, ce qui est nettement plus simple d'un point dé vue pratique. Pour terminer je présente la plus grande évaluation à fine échelle d'impact potentiel des changements climatiques sur la flore des montagnes conduite à ce jour. Cette évaluation englobe 12 zones d'études réparties sur toutes les chaines de montages principales d'Europe occidentale et centrale. Les résultats montrent que certaines chaines de montagnes (les Pyrénées et les Alpes Autrichiennes) sont projetées comme plus sensibles aux changements climatiques que d'autres (les Alpes Scandinaves et les Highlands d'Ecosse). Les résultats obtenus montrent aussi que les modèles à échelle fine projettent des impacts de changement climatiques (p. ex. taux d'extinction d'espèces) moins sévères que les modèles à échelle large. Cela laisse supposer que les modèles a échelle fine sont capables de modéliser des micro-niches climatiques non-détectées par les modèles à échelle large.

Interactions between respiration and systemic hemodynamics. Part II: practical implications in critical care.

In Part I of this review, we have covered basic concepts regarding cardiorespiratory interactions. Here, we put this theoretical framework to practical use. We describe mechanisms underlying Kussmaul's sign and pulsus paradoxus. We review the literature on the use of respiratory variations of blood pressure to evaluate volume status. We show the possibilities of attaining the latter aim by investigating with ultrasonography how the geometry of great veins fluctuates with respiration. We provide a Guytonian analysis of the effects of PEEP on cardiac output. We terminate with some remarks on the potential of positive pressure breathing to induce acute cor pulmonale, and on the cardiovascular mechanisms that at times may underly the failure to wean a patient from the ventilator.

Décubitus ventral et syndrome de détresse respiratoire aiguë de l'adulte: de la théorie à la pratique [Prone position mechanical ventilation in the Acute Respiratory Distress syndrome: theoretical and practical considerations].

Mortality of the acute respiratory distress syndrome (ARDS) remains extremely high and only few evidence-based specific treatments are currently available. Protective mechanical ventilation has emerged as the comer stone of the management of ARDS to avoid the occurrence of ventilation-induced lung injuries (VILI). Mechanical ventilation in the prone position has often been considered as a rescue therapy reserved to refractory hypoxemia. Since the publication of the PROSEVA study in 2013, early prone positioning for mechanical ventilation should be recommended to improve survival of patients with severe ARDS. In this article, both the theoretical and practical aspects of mechanical ventilation in prone position are reviewed.

Hallux valgus: résumé pratique [Hallux valgus: practical summary].

Hallux valgus arises from static and dynamic unbalance of the forefoot. Possibilities of conservative treatment are limited. This paper recalls the essentials of physiopathology and exposes briefly to the non-operators the most current amongst 150 operative techniques described. While becoming more complex, the surgery of hallux valgus has proven to gain efficiency. Surgical indication, based on biomechanics, should be very careful, which gives a greater interest to this discipline.

Validation of the Mini Nutritional Assessment short-form (MNA-SF): a practical tool for identification of nutritional status.

OBJECTIVE: To validate a revision of the Mini Nutritional Assessment short-form (MNA(R)-SF) against the full MNA, a standard tool for nutritional evaluation. METHODS: A literature search identified studies that used the MNA for nutritional screening in geriatric patients. The contacted authors submitted original datasets that were merged into a single database. Various combinations of the questions on the current MNA-SF were tested using this database through combination analysis and ROC based derivation of classification thresholds. RESULTS: Twenty-seven datasets (n=6257 participants) were initially processed from which twelve were used in the current analysis on a sample of 2032 study participants (mean age 82.3y) with complete information on all MNA items. The original MNA-SF was a combination of six questions from the full MNA. A revised MNA-SF included calf circumference (CC) substituted for BMI performed equally well. A revised three-category scoring classification for this revised MNA-SF, using BMI and/or CC, had good sensitivity compared to the full MNA. CONCLUSION: The newly revised MNA-SF is a valid nutritional screening tool applicable to geriatric health care professionals with the option of using CC when BMI cannot be calculated. This revised MNA-SF increases the applicability of this rapid screening tool in clinical practice through the inclusion of a "malnourished" category.

Metacognitive training for schizophrenia: a multicentre randomised controlled trial.

A psychotherapeutic approach for schizophrenia is now recommended as an adjuvant for psychopharmacology, since antipsychotic medications only have a partial impact especially as regards positive symptoms and insight. In addition, cognitive distortions and the lack of metacognitive skills might increase positive symptoms leading to poor social functioning. This underlines the need for specific approaches which target cognitive processes relevant for insight, and abilities in metacognition. Metacognitive training (MCT) is a structured group intervention, which enhances a patient's reflection on cognitive biases and improves problem-solving. The aim of our study was to assess MCTs' short term impact on insight, symptoms and quality of life. Fifty patients with schizophrenia or schizoaffective disorders and persistent positive symptoms (delusions or hallucinations) were enrolled in the study. After baseline assessment participants were randomised either to supportive therapy or MCT. Both groups used the same design (1h-session twice a week during 8weeks) although the basic knowledge given to participants was different between interventions. Participants were assessed at eight weeks based on the Scale to Assess Unawareness of Mental Disorder, Positive and Negative Syndrome Scale (PANSS), Psychotic Symptom Rating Scales, the Calgary Depression Scale for Schizophrenia and the Quality of Life Scale. Between-group differences were significant in favour of MCT on the PANSS positive scale. Between-group differences in post- and pre-test values showed a trend in favour of MCT for insight on hallucinations. Results of our study indicate that the MCT has an effect on reducing positive symptomatology, and a trend impact on insight and social functioning.

Information security and the enforcement of secrecy : the practical application of quantum key distribution

There is no doubt about the necessity of protecting digital communication: Citizens are entrusting their most confidential and sensitive data to digital processing and communication, and so do governments, corporations, and armed forces. Digital communication networks are also an integral component of many critical infrastructures we are seriously depending on in our daily lives. Transportation services, financial services, energy grids, food production and distribution networks are only a few examples of such infrastructures. Protecting digital communication means protecting confidentiality and integrity by encrypting and authenticating its contents. But most digital communication is not secure today. Nevertheless, some of the most ardent problems could be solved with a more stringent use of current cryptographic technologies. Quite surprisingly, a new cryptographic primitive emerges from the ap-plication of quantum mechanics to information and communication theory: Quantum Key Distribution. QKD is difficult to understand, it is complex, technically challenging, and costly-yet it enables two parties to share a secret key for use in any subsequent cryptographic task, with an unprecedented long-term security. It is disputed, whether technically and economically fea-sible applications can be found. Our vision is, that despite technical difficulty and inherent limitations, Quantum Key Distribution has a great potential and fits well with other cryptographic primitives, enabling the development of highly secure new applications and services. In this thesis we take a structured approach to analyze the practical applicability of QKD and display several use cases of different complexity, for which it can be a technology of choice, either because of its unique forward security features, or because of its practicability.