Concordia University

About: Concordia University is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Context (language use) & Control theory. 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.

Respiratory function in the muscular dystrophies

Abstract: The purpose of this investigation was to compare the respiratory function of patients with different clinical types of muscular dystrophy (MD). A total of 190 patients representing facioscapulohumeral MD (n = 20), limb-girdle MD (n = 50), Becker MD (n = 20), Duchenne MD (n = 90), and the "intermediate" type of MD (n = 10) were studied using simple spirometric respiratory function tests. The respiratory modifications observed in the 3 adult forms indicate that pulmonary function was almost normal. Respiratory function in Duchenne muscular dystrophy (DMD) was always characterized by a restrictive syndrome which severely impaired pulmonary function. The vital capacity (VC) underwent ascending, plateau, and descending phases during the course of the disease. The VC at the plateau stage may be used as an estimate of life span. The most interesting finding was the high degree of variability in the restrictive syndrome associated with DMD. In the DMD group 30% presented a severe restrictive respiratory syndrome associated with a life span of less than 20 years (Type 1), 40% had a serious restrictive syndrome and variable mortality (Type 2), and the remaining 30% had a moderate restrictive respiratory syndrome (Type 3).

Exposure to mild stress enhances the reinforcing efficacy of intravenous heroin self-administration in rats.

Abstract: The effect of a mild footshock on intravenous heroin self-administration was examined in male rats. Animals in the stress condition were exposed to 10 min of intermittent footshock (0.5 mA; 0.5 s on, with a mean off period of 40 s) before each of four daily self-administration sessions. Animals in the control group were not exposed to footshock. Following acquisition of heroin-reinforced behavior (100 micrograms/kg per infusion), during which no group differences emerged, animals were placed on a progressive ratio schedule of reinforcement and were subsequently tested under a decreasing series of doses. Animals exposed to footshock before each drug session had higher rates of lever pressing for heroin and achieved higher final ratios on the progressive ratio schedule than animals in the control group at the higher doses of heroin. Thus, under the conditions of this experiment, exposure to mild intermittent stress appeared to enhance the reinforcing efficacy of heroin. The parameters of footshock used in the present study, and its relation to drug availability may characterize conditions under which stress leads to increased opioid abuse.

From Very Weak to Very Strong: Analyzing Password-Strength Meters

Abstract: Millions of users are exposed to password-strength meters/checkers at highly popular web services that use user- chosen passwords for authentication. Recent studies have found evidence that some meters actually guide users to choose better passwords—which is a fairly rare-bit of good news in password research. However, these meters are mostly based on ad-hoc design. At least, as we found, most vendors do not provide any explanation of their design choices, sometimes making them appear to be a black box. We analyze password meters deployed in selected popular websites, by measuring the strength labels assigned to common passwords from several password dictionaries. From this empirical analysis with millions of passwords, we report prominent characteristics of meters as deployed at popular websites. We shed light on how the server-end of some meters functions, provide examples of highly inconsistent strength outcomes for the same password in different meters, along with examples of many weak passwords being labeled as strong or even very strong. These weaknesses and inconsistencies may confuse users in choosing a stronger password, and thus may weaken the purpose of these meters. On the other hand, we believe these findings may help improve existing meters, and possibly make them an effective tool in the long run.

Pedagogy of Passion for Sustainability

Abstract: Our current practices in teaching sustainable management are replete with scientific facts, analytical tools, optimization models, and management techniques. The key pedagogical goal is to help stu...