No description available.

Recent observations and numerical simulations have significantly improved our understanding of tornadic storms. However, our knowledge of tornado-genesis remains rudimentary. Necessary atmospheric conditions favoring the formation of tornadoes in supercell storms are known, but sufficient conditions remain elusive. The underlying reason is that the processes involved in environment-storm and storm-tornado interactions are not fully understood, as numerical models in the past lacked sufficient resolution to resolve these interactions satisfactorily. In this thesis, an attempt is made to fill this gap by performing a multi-grid high resolution simulation of a supercell storm spawning a tornado-like vortex. Four grids, with grid sizes of 600 m, 200 m, 70 m, and 30 m, are used to allow explicit simulation of storm-tornado interactions. Diagnostic analysis of the modeling results allows an investigation of the origin of rotation at both the storm scale and the tornado scale. / The simulation results showed that the origin of vertical rotation at storm scale during the early stage of storm development is due to tilting of the horizontal vorticity in the environment. This so called mesocyclone then further strengthens by the mechanism of stretching and Dynamic Pipe Effect and descends downwards. During the time of mesocyclone intensification, incipient surface vertical vortices form along the outflow boundary created by the rear flank downdraft due to the process of horizontal shear instability. / One of the surface vortices experiences an initial exponential growth in its vorticity by interacting with the descending mesocyclone and merging with multiple smaller satellite vortices. The tornado-like vortex (TLV) which forms has a maximum horizontal wind of 103 m s-1 and a minimum central pressure of 927 hPa. Vorticity budgets of the mesocyclone and the TLV are computed to assess quantitatively the importance of various processes for rotation. / Sensitivity experiments were also performed to determine the effect of varying the environmental conditions on the mesocyclone and surface vorticity. It was found that as the low-level vertical shear of the environmental wind increases, the mesocyclone intensifies and favors the intensification of near surface vorticity. The presence of drier layers in the upper and middle troposphere eventually produces a weaker mesocyclone and weaker outflow boundaries. On the other hand, inclusion of the ice phase processes produces a stronger mesocyclone and more intense outflow boundaries to enhance the intensification of near surface vorticity.

Commercial education, or, as it is more recently called, Business education, is becoming increasingly important in Quebec. Some aspects have been taught for many years in the high schools of this province, but for the most part educators have concentrated more on the college-preparatory teaching. [...]

Violent and aggressive behavior is a subset of antisocial behavior that is of particular concern to the criminal justice system and to the general public. A challenge facing mental health professionals and the criminal justice system is to assess—with a reasonable degree of accuracy—the likelihood that a young offender will recidivate and to arrange appropriate interventions. Because of its psychometric properties and high predictive validity, the Hare Psychopathy Checklist-Revised (PCL-R) is being incorporated into risk assessment batteries for use with adults. The purpose of the study was to extend the risk paradigm to adolescent offenders, investigating the predictive validity of the Psychopathy Checklist: Youth Version (PCL:YV) from adolescence to adulthood. Subjects were 157 admissions, ages 12-18, referred to Youth Court Services for psychological or psychiatric assessment. Archival data were used to complete retrospectively the PCL:YV and to code criminal history and demographic data on each of the subjects. Follow-up criminal record data were collected, with an average follow-up time of ten years. Over the follow-up period psychopaths demonstrated a greater risk for committing violent offences than nonpsychopaths. They committed violent offences at a higher rate, earlier following their release from custody, and were more likely to escape from custody than nonpsychopaths. Further, results indicate that PCL:YV score, a difference in performance - verbal intellectual functioning (P > V Index), and history of self-harm contributed significantly to the prediction of violent outcome, over and above the contribution of a combination of criminal-history and demographic variables. Finally, background and demographic characteristics were compared between violent and nonviolent psychopaths. Findings are discussed in the context of current conceptualizations of psychopathy and adolescent antisocial behavior.

No description available.

No description available.

Radar cells from the GATE experiment, from Spain and from the Montreal area were followed and measurements of their total rain flux and area were extracted. The values of the flux and area, for each one of the cells, for initial time increments T(,0) were used to evaluate various extrapolation schemes for forecasting purposes. The extrapolation procedure that gave the smallest error in forecasting the changes in flux and area, was found to be the linear one and the optimum increment T(,0) was about 30 min. However, even though these techniques have the advantage of establishing a trend in the behavior of the flux and area with time, a comparison of the forecast errors from the linear extrapolation scheme with those from the assumption of no change in cell area and rain flux shows insignificant improvements. A technique including both cell motion and internal changes in flux and area of the rain cells was developed to evaluate the accuracy of rain accumulation forecasts. Again, it was found that the errors were similar with those generated by the assumption of no change in rain flux and area from the moving cell. / The preceding results were used as a possible input into the design and evaluation of cloud seeding experiments. Based on this, a method is developed which gives the necessary number of experiments (i.e., seeded cases) in order for a seeding factor to be statistically significant at specified confidence levels. As a conclusion, it can be stated that the use of short term rain predictions (which are translated as differences of the rain flux in time) is very promising. In comparison to other techniques described in the literature this method appears to be superior, in the sense that fewer experiments are needed to detect seeding factors at specified confidence levels.

Scientistic authors in the latter half of the 19 th century and the early 20th century, such as Ernest Renan and H. G. Wells, discounted revealed religion. Yet they believed in the secular myth of an imminent technological Eden and they elevated science itself to the dignity of a religion. In so doing, they shaped bold visions of the future, drawing heavily on a millenary store of Western myth and metaphor. In historical terms, the myth of an imminent technological Eden represents a survival and a fusion of the ancient Greek myth of the Golden Age along with three Judeo-Christian myths: Biblical time, Earthly Paradise and the Apocalypse. Since the Enlightenment, the process of secularization has drained the religious content of such myths, although it does not deprive them of any of their deeply emotional force. This explains why the 19th century myth of an imminent technological Eden has considerable staying-power, in spite of the many events since 1945 which seem to discredit it.

No description available.

No description available.