Concordia University

About: Concordia University is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Control theory & Population. The organization has 13565 authors who have published 31084 publications receiving 783525 citations. The organization is also known as: Sir George Williams University & Loyola College, Montreal.

Organizational citizenship behavior: a case study of culture, leadership and trust

Abstract: The case will test two hypotheses regarding three variables influencing the level of employee satisfaction and organizational citizenship at GAMMA, a manufacturer of plastics. Two hypotheses were developed from a review of the literature and initial results from exploratory research ( H1: low employee satisfaction at GAMMA is a direct result of an autocratic leadership style, low trust environment and weak corporate culture; H2: low employee citizenship is a direct result of low employee satisfaction). Results suggest that although the perception was that employee satisfaction and organizational citizenship were low (from the exploratory research); both quantitative and descriptive data indicated these were not. Moreover, the hypotheses were not conclusively supported quantitatively. High trust was not obtained. Also a specific high leadership style and a specific culture resulting in high employee satisfaction were also questionable. Moreover, it was not observed that a strong correlation existed statist...

Computer-Aided Breast Cancer Diagnosis Based on the Analysis of Cytological Images of Fine Needle Biopsies

Abstract: The effectiveness of the treatment of breast cancer depends on its timely detection. An early step in the diagnosis is the cytological examination of breast material obtained directly from the tumor. This work reports on advances in computer-aided breast cancer diagnosis based on the analysis of cytological images of fine needle biopsies to characterize these biopsies as either benign or malignant. Instead of relying on the accurate segmentation of cell nuclei, the nuclei are estimated by circles using the circular Hough transform. The resulting circles are then filtered to keep only high-quality estimations for further analysis by a support vector machine which classifies detected circles as correct or incorrect on the basis of texture features and the percentage of nuclei pixels according to a nuclei mask obtained using Otsu's thresholding method. A set of 25 features of the nuclei is used in the classification of the biopsies by four different classifiers. The complete diagnostic procedure was tested on 737 microscopic images of fine needle biopsies obtained from patients and achieved 98.51% effectiveness. The results presented in this paper demonstrate that a computerized medical diagnosis system based on our method would be effective, providing valuable, accurate diagnostic information.

Chemical Stimulation of the Ventral Hippocampus Elevates Nucleus Accumbens Dopamine by Activating Dopaminergic Neurons of the Ventral Tegmental Area

Abstract: Dual-probe microdialysis (with HPLC and electrochemical detection) in freely moving rats and single-unit recording in anesthetized rats were used to study the extent to which impulse flow through the ventral tegmental area (VTA) contributes to elevations in nucleus accumbens (NAS) dopamine (DA) evoked by stimulation of the ventral subiculum (VS). During perfusion of artificial extracellular fluid into the VTA, injections of 0.74 microgram of the excitatory amino acid NMDA into the VS elevated accumbens DA to >150% of basal values. During intra-VTA perfusion of either 1 microM tetrodotoxin (which blocks impulse flow) or 1 mM kynurenic acid (which blocks excitatory glutamate receptors), injections of NMDA into the VS failed to elevate accumbens DA. Thus, increased impulse flow through VTA DA neurons, mediated by excitatory glutamate inputs to this region, appears critical for VS stimulation to elevate NAS DA. Increased impulse flow through VTA DA neurons was confirmed using single-unit recording in anesthetized rats. Intra-VS NMDA injections increased the firing rates of 45% (14 of 31), decreased the firing rates of 13% (4 of 31), and had no effect on 42% (13 of 31) of VTA DA neurons. Increases in firing rates were evident within 15 min of NMDA injections, a time at which VS NMDA injections elevate accumbens DA in awake animals. The results of the present experiments identify the VTA as a critical site through which outputs from the VS modulate NAS dopaminergic neurotransmission.

Why we refactor? confessions of GitHub contributors

Abstract: Refactoring is a widespread practice that helps developers to improve the maintainability and readability of their code. However, there is a limited number of studies empirically investigating the actual motivations behind specific refactoring operations applied by developers. To fill this gap, we monitored Java projects hosted on GitHub to detect recently applied refactorings, and asked the developers to explain the reasons behind their decision to refactor the code. By applying thematic analysis on the collected responses, we compiled a catalogue of 44 distinct motivations for 12 well-known refactoring types. We found that refactoring activity is mainly driven by changes in the requirements and much less by code smells. Extract Method is the most versatile refactoring operation serving 11 different purposes. Finally, we found evidence that the IDE used by the developers affects the adoption of automated refactoring tools.