Improved Weighted Random Forest for Classification Problems

Several studies have shown that combining machine learning models in an appropriate way will introduce improvements in the individual predictions made by the base models. The key to make well-performing ensemble model is in the diversity of the base models. Of the most common solutions for introducing diversity into the decision trees are bagging and random forest. Bagging enhances the diversity by sampling with replacement and generating many training data sets, while random forest adds selecting a random number of features as well. This has made the random forest a winning candidate for many machine learning applications. However, assuming equal weights for all base decision trees does not seem reasonable as the randomization of sampling and input feature selection may lead to different levels of decision-making abilities across base decision trees. Therefore, we propose several algorithms that intend to modify the weighting strategy of regular random forest and consequently make better predictions. The designed weighting frameworks include optimal weighted random forest based on ac-curacy, optimal weighted random forest based on the area under the curve (AUC), performance-based weighted random forest, and several stacking-based weighted random forest models. The numerical results show that the proposed models are able to introduce significant improvements compared to regular random forest

Exercise Training Reverses Extrapulmonary Impairments in Smoke-exposed Mice

Purpose: Cigarette smoking is the main risk factor for chronic obstructive pulmonary disease and emphysema. However, evidence on the extrapulmonary effects of smoke exposure that precede lung impairments remains unclear at present, as are data on nonpharmacological treatments such as exercise training. Methods: Three groups of mice, including control (n = 10), smoking (n = 10), and smoking with 6 wk of high-intensity interval treadmill running (n = 11), were exposed to 20 wk of fresh air or whole-body cigarette smoke. Exercise capacity (peak oxygen uptake) and lung destruction (histology) were subsequently measured, whereas the heart, peripheral endothelium (aorta), and respiratory (diaphragm) and limb (extensor digitorum longus and soleus) skeletal muscles were assessed for in vivo and in vitro function, in situ mitochondrial respiration, and molecular alterations. Results: Smoking reduced body weight by 26% (P 0.05). Smoking impaired exercise capacity by 15% while inducing right ventricular dysfunction by ~20%, endothelial dysfunction by ~20%, and diaphragm muscle weakness by ~15% (all P < 0.05), but these were either attenuated or reversed by exercise training (P < 0.05). Compared with controls, smoking mice had normal limb muscle and mitochondrial function (cardiac and skeletal muscle fibers); however, diaphragm measures of oxidative stress and protein degradation were increased by 111% and 65%, respectively (P < 0.05), but these were attenuated by exercise training (P < 0.05). Conclusions: Prolonged cigarette smoking reduced exercise capacity concomitant with functional impairments to the heart, peripheral endothelium, and respiratory muscle that preceded the development of overt emphysema. However, high-intensity exercise training was able to reverse these smoke-induced extrapulmonary impairments

The effects of smoking on whisker movements: a quantitative measure of exploratory behaviour in rodents

Nicotine, an important component of cigarette smoke, is a neurotransmitter that contributes to stress, depression and anxiety in smokers. In rodents, it increases anxiety and reduces exploratory behaviours. However, so far, the measurements of exploratory behaviour in rodents have only been semi-quantitative and lacking in sufficient detail to characterise the temporal effect of smoking cessation. As rodents, such as mice and rats, primarily use whiskers to explore their environment, we studied the effect of 3 months smoking with 1 and 2 weeks smoking cessation on whisker movements in mice, using high-speed video camera footage and image analysis. Both protraction and retraction whisker velocities were increased in smoking mice (p<0.001) and returned to normal following just one week of smoking cessation. In addition, locomotion speeds were decreased in smoking mice, and returned to normal following smoking cessation. Lung function was also impacted by smoking and remained impaired even following smoking cessation. We suggest that the increased whisker velocities in the smoking mice reflect reduced exploration and impeded tactile performance. The increase in whisker velocity with smoking, and its reduction following smoking cessation, also lends support to acetylcholine being involved in awareness, attention and alertness pathways. It also shows that smoking-induced behavioural changes can be reversed with smoking cessation, which may have implications for human smokers

Searching Markush formulae directed to medical applications

Markush formulae are beyond any doubt the most efficient way of claiming a generic group of compounds. Indeed they are necessary to give applicants adequate protection for their invention. However, due to their complex nature, it is not always straightforward to determine their exact scope. The present paper looks at two extremes of Markush structures, which are unsearchable as such, the so-called "A-B-C type molecules" and "too simple compounds". Appropriate patentability search strategies, including non-unity and incomplete searches, are defined. Frequently, claimed Markush formulae partially overlap with prior art generic structures. Criteria for selecting the most relevant documents in such cases are discussed, including novelty and inventive step aspects of selection inventions. In a case study, the use of different search tools is compared.Markush formulae Unsearchable molecules Partially overlapping formulae Selection inventions REGISTRY CAPLUS MARPAT BEILSTEIN

Integration of Polish workers in Norway : the role of labour unions

The research tries to answer how LUs could contribute to the integration of Poles into the Norwegian labour market. It tries to specify the special needs of those workers and ways in which labour Unions tried to meet them. The study analyzes impact of actions taken by the labour union and tries to determine what kind of influence, on the relations between Poles and labour unions, can have the fact that large number of Polish workers is employed by temporary work agencies. The study was conducted in Oslo county among members of Oslo Construction Workers Union. This organization is known as the one that noticed large successes in recruiting immigrants. Findings show that there are problems with communication channels. Those used by the union differ from those that are demanded by Poles. The difference between those types of communication is constituted by division on activities and 'presence' of the labour union. The study also analyzes special need voiced by the respondents: postulate of information, lack of accreditation of professional skills and vocational education, the case of 'fixing contracts' by the labour union in temporary work agencies and disparity between formal and informal positions performed at workplace. All those needs aren't however answered yet. Result of this state is disappointment of Poles. The study forms the core category - the formality hypothesis, which describes the way that labour union can influence integration of Poles into the labour market

Tests de spécifications dynamiques alternatives et application à la demande de viande en Belgique

International audienceCet article examine des spécifications alternatives d'ajustement dynamique en utilisant la version linéarisée du modèle AIDS appliqué à la demande de viande en Belgique. Le modèle estimé incorpore aussi des variables démographiques pour tenir compte des changements structurels dans les préférences des consommateurs. En prenant comme cadre de référence analytique unificateur un modèle à correction d'erreurs du premier ordre, plusieurs tests sont mis en oeuvre pour déterminer et valider la meilleure spécification de modèle dynamique. Les résultats indiquent que l'approche très utilisée d'un modèle dynamique avec un coefficient unique d'ajustement (i. e. la matrice des coefficients d'ajustement est diagonale), ainsi que les modèles statiques et auto-régressifs sont rejetés par les données. La spécification proposée reposant sur un processus d'ajustement dynamique symétrique semble être une alternative prometteuse