A Classification of Tools for Learning Logic

A table showing a comparison and classification of tools (intelligent tutoring systems) for e-learning of Logic at a college level.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 µg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 µg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

Health problems among detainees in Switzerland: a study using the ICPC-2 classification.

BACKGROUND: Little is known about the health status of prisoners in Switzerland. The aim of this study was to provide a detailed description of the health problems presented by detainees in Switzerland's largest remand prison. METHODS: In this retrospective cross-sectional study we reviewed the health records of all detainees leaving Switzerland's largest remand prison in 2007. The health problems were coded using the International Classification for Primary Care (ICPC-2). Analyses were descriptive, stratified by gender. RESULTS: A total of 2195 health records were reviewed. Mean age was 29.5 years (SD 9.5); 95% were male; 87.8% were migrants. Mean length of stay was 80 days (SD 160). Illicit drug use (40.2%) and mental health problems (32.6%) were frequent, but most of these detainees (57.6%) had more generic primary care problems, such as skin (27.0%), infectious diseases (23.5%), musculoskeletal (19.2%), injury related (18.3%), digestive (15.0%) or respiratory problems (14.0%). Furthermore, 7.9% reported exposure to violence during arrest by the police. CONCLUSION: Morbidity is high in this young, predominantly male population of detainees, in particular in relation to substance abuse. Other health problems more commonly seen in general practice are also frequent. These findings support the further development of coordinated primary care and mental health services within detention centers.

Pathophysiology and classification of the vibration white finger.

Skin, arteries and nerves of the upper extremities can be affected by vibration exposure. Recent advances in skin and vascular biology as well as new investigative methods, have shown that neurovascular symptoms may be due to different vascular and neurological disorders which should be differentiated if proper management is to be evaluated. Three types of vascular disorder can be observed in the vibration white finger: digital organic microangiopathy, a digital vasospastic phenomenon and arterial thrombosis in the upper extremities. An imbalance between endothelin-1 and calcitonin-gene-related peptide is probably responsible for the vasospastic phenomenon. Moreover, paresthesiae can be due to either a diffuse vibration neuropathy or a carpal tunnel syndrome. A precise diagnosis is then necessary to adapt the treatment to individual cases. A classification describing the type and severity of the vascular lesions is presented. Asymptomatic lesions are included for adequate epidemiological studies and risk assessment of vibrating tools. Monitoring of vibration exposed workers should include not only a questionnaire about symptoms, but also a clinical evaluation including diagnostic tests for the screening of early asymptomatic neurovascular injuries.

Cluster kernels for semisupervised classification of VHR urban images

In this paper, we present and apply a semisupervised support vector machine based on cluster kernels for the problem of very high resolution image classification. In the proposed setting, a base kernel working with labeled samples only is deformed by a likelihood kernel encoding similarities between unlabeled examples. The resulting kernel is used to train a standard support vector machine (SVM) classifier. Experiments carried out on very high resolution (VHR) multispectral and hyperspectral images using very few labeled examples show the relevancy of the method in the context of urban image classification. Its simplicity and the small number of parameters involved make it versatile and workable by unexperimented users.

Semi-online neural-Q_leaming for real-time robot learning

Reinforcement learning (RL) is a very suitable technique for robot learning, as it can learn in unknown environments and in real-time computation. The main difficulties in adapting classic RL algorithms to robotic systems are the generalization problem and the correct observation of the Markovian state. This paper attempts to solve the generalization problem by proposing the semi-online neural-Q_learning algorithm (SONQL). The algorithm uses the classic Q_learning technique with two modifications. First, a neural network (NN) approximates the Q_function allowing the use of continuous states and actions. Second, a database of the most representative learning samples accelerates and stabilizes the convergence. The term semi-online is referred to the fact that the algorithm uses the current but also past learning samples. However, the algorithm is able to learn in real-time while the robot is interacting with the environment. The paper shows simulated results with the "mountain-car" benchmark and, also, real results with an underwater robot in a target following behavior

Automatic classification of breast density

A recent trend in digital mammography is computer-aided diagnosis systems, which are computerised tools designed to assist radiologists. Most of these systems are used for the automatic detection of abnormalities. However, recent studies have shown that their sensitivity is significantly decreased as the density of the breast increases. This dependence is method specific. In this paper we propose a new approach to the classification of mammographic images according to their breast parenchymal density. Our classification uses information extracted from segmentation results and is based on the underlying breast tissue texture. Classification performance was based on a large set of digitised mammograms. Evaluation involves different classifiers and uses a leave-one-out methodology. Results demonstrate the feasibility of estimating breast density using image processing and analysis techniques

L'arrêt cardio-respiratoire (ACR) au cabinet médical est-il une réalité et y a-t-il nécessité de s'équiper d'un défribillateur semi-automatique (DSA)?

Introduction: Cette étude a pour but de déterminer la fréquence de survenue de l'arrêt cardio-respiratoire (ACR) au cabinet médical qui constitue un élément de décision quant à la justification de la présence d'un défibrillateur semi-automatique (DSA) au cabinet médical. Matériel et Méthode: Analyse rétrospective des fiches d'intervention pré-hospitalière des ambulances et des SMUR (Service Mobile d'Urgence et de Réanimation) du canton de Vaud (650'000 habitants) entre 2003 et 2006 qui relataient un ACR. Les variables suivantes ont été analysées: chronologie de l'intervention, mesures de réanimation cardio-pulmonaire (RCP) appliquées, diagnostic présumé, suivi à 48 heures. Résultats: 17 ACR (9 _, 8 _) ont eu lieu dans les 1655 cabinets médicaux du canton de Vaud en 4 ans sur un total de 1753 ACR extrahospitaliers, soit 1% de ces derniers. Tous ont motivés une intervention simultanée d'une ambulance et d'un SMUR. L'âge moyen était de 70 ans. Le délai entre l'ACR et l'arrivée sur site d'un DSA était en moyenne de plus de 10 minutes (min-max: 4-25 minutes). Dans 13 cas évaluables, une RCP était en cours à l'arrivée des renforts, mais seulement 7 étaient qualifiées d'efficaces. Le rythme initial était une fibrillation ventriculaire (FV) dans 8 cas et ont tous reçu un choc électrique externe (CEE), dont 1 avant l'arrivée des secours administré dans un cabinet équipé d'un DSA. Le diagnostic était disponible pour 9 cas: 6 cardiopathies, 1 embolie pulmonaire massive, 1 choc anaphylactique et 1 tentamen médicamenteux. Le devenir de ces patients a été marqué par 6 décès sur site, 4 décès à l'admission à l'hôpital et 7 vivants à 48 heures. Les données ne permettent pas d'avoir un suivi ni à la sortie de l'hôpital ni ultérieurement. Conclusions: Bien que la survenue d'un ACR soit très rare au cabinet médical, il mérite une anticipation particulière de la part du médecin. En effet, le délai d'arrivée des services d'urgences nécessite la mise en oeuvre immédiate de mesures par le médecin. En outre, comme professionnel de la santé, il se doit d'intégrer la chaîne de survie en procédant à une alarme précoce du 144 et initier des gestes de premier secours («Basic Life Support»). La présence d'un DSA pourrait être envisagée en fonction notamment de l'éloignement de secours professionnels équipés d'un DSA.

Breast cancer prognostic classification in the molecular era: the role of histological grade.

Breast cancer is a heterogeneous disease with varied morphological appearances, molecular features, behavior, and response to therapy. Current routine clinical management of breast cancer relies on the availability of robust clinical and pathological prognostic and predictive factors to support clinical and patient decision making in which potentially suitable treatment options are increasingly available. One of the best-established prognostic factors in breast cancer is histological grade, which represents the morphological assessment of tumor biological characteristics and has been shown to be able to generate important information related to the clinical behavior of breast cancers. Genome-wide microarray-based expression profiling studies have unraveled several characteristics of breast cancer biology and have provided further evidence that the biological features captured by histological grade are important in determining tumor behavior. Also, expression profiling studies have generated clinically useful data that have significantly improved our understanding of the biology of breast cancer, and these studies are undergoing evaluation as improved prognostic and predictive tools in clinical practice. Clinical acceptance of these molecular assays will require them to be more than expensive surrogates of established traditional factors such as histological grade. It is essential that they provide additional prognostic or predictive information above and beyond that offered by current parameters. Here, we present an analysis of the validity of histological grade as a prognostic factor and a consensus view on the significance of histological grade and its role in breast cancer classification and staging systems in this era of emerging clinical use of molecular classifiers.

Validation and reproducibility of a semi-quantitative Food Frequency Questionnaire for use in elderly Swiss women.

OBJECTIVE: The principal aim of this study was to develop a Swiss Food Frequency Questionnaire (FFQ) for the elderly population for use in a study to investigate the influence of nutritional factors on bone health. The secondary aim was to assess its validity and both short-term and long-term reproducibility. DESIGN: A 4-day weighed record (4 d WR) was applied to 51 randomly selected women of a mean age of 80.3 years. Subsequently, a detailed FFQ was developed, cross-validated against a further 44 4-d WR, and the short- (1 month, n = 15) and long-term (12 months, n = 14) reproducibility examined. SETTING: French speaking part of Switzerland. SUBJECTS: The subjects were randomly selected women recruited from the Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture cohort study. RESULTS: Mean energy intakes by 4-d WR and FFQ showed no significant difference [1564.9 kcal (SD 351.1); 1641.3 kcal (SD 523.2) respectively]. Mean crude nutrient intakes were also similar (with nonsignifcant P-values examining the differences in intake) and ranged from 0.13 (potassium) to 0.48 (magnesium). Similar results were found in the reproducibility studies. CONCLUSION: These findings provide evidence that this FFQ adequately estimates nutrient intakes and can be used to rank individuals within distributions of intake in specific populations.

Evaluation of the GlideScope (R) for tracheal intubation in patients with cervical spine immobilization by a semi-rigid collar

Background: In patients with cervical spine injury, a cervical collar may prevent cervical spine movements but renders tracheal intubation with a standard laryngoscope difficult if not impossible. We hypothesized that despite the presence of a semi-rigid cervical collar and with the patient's head taped to the trolley, we would be able to intubate all patients with the GlideScopeR and its dedicated stylet. Methods: 50 adult patients (ASA 1 or 2, BMI ≤35 kg/m2) scheduled for elective surgical procedures requiring tracheal intubation were included. After standardized induction of general anesthesia and neuromuscular blockade, the neck was immobilized with an appropriately sized semi-rigid Philadelphia Patriot® cervical collar, the head was taped to the trolley. Laryngoscopy was attempted using a Macintosh laryngoscope blade 4 and the modified Cormack Lehane grade was noted. Subsequently, laryngoscopy with the GlideScopeR was graded and followed by oro-tracheal intubation. Results: All patients were successfully intubated with the GlideScopeR and its dedicated stylet. The median intubation time was 50 sec [43; 61]. The modified Cormack Lehane grade was 3 or 4 at direct laryngoscopy. It was significantly reduced with the GlideScopeR (p <0.0001), reaching 2a in most of patients. Maximal mouth opening was significantly reduced with the cervical collar applied, 4.5 cm [4.5; 5.0] vs. 2.0 cm [1.8; 2.0] (p <0.0001). Conclusions: The GlideScope® allows oro-tracheal intubation in patients having their cervical spine immobilized by a semi-rigid collar and their head taped to the trolley. It furthermore decreases significantly the modified Cormack Lehane grade.