Informe del crucero Krill III, a bordo del barco de investigación científica Alexander Agassiz de la Universidad de California y estadía en el departamento de oceanología de Montemar-Chile

Expone los resultados del análisis de las muestras de zooplancton colectados frente al Perú, para cumplir uno de los objetivos, la obtención de huevos y larvas de peces y Myctophidoe en diversas fases de desarrollo.

Trigger and data link system for CMS Resistive Plate Chambers at the LHC accelerator

The purpose of the work was to realize a high-speed digital data transfer system for RPC muon chambers in the CMS experiment on CERN’s new LHC accelerator. This large scale system took many years and many stages of prototyping to develop, and required the participation of tens of people. The system interfaces to Frontend Boards (FEB) at the 200,000-channel detector and to the trigger and readout electronics in the control room of the experiment. The distance between these two is about 80 metres and the speed required for the optic links was pushing the limits of available technology when the project was started. Here, as in many other aspects of the design, it was assumed that the features of readily available commercial components would develop in the course of the design work, just as they did. By choosing a high speed it was possible to multiplex the data from some the chambers into the same fibres to reduce the number of links needed. Further reduction was achieved by employing zero suppression and data compression, and a total of only 660 optical links were needed. Another requirement, which conflicted somewhat with choosing the components a late as possible was that the design needed to be radiation tolerant to an ionizing dose of 100 Gy and to a have a moderate tolerance to Single Event Effects (SEEs). This required some radiation test campaigns, and eventually led to ASICs being chosen for some of the critical parts. The system was made to be as reconfigurable as possible. The reconfiguration needs to be done from a distance as the electronics is not accessible except for some short and rare service breaks once the accelerator starts running. Therefore reconfigurable logic is extensively used, and the firmware development for the FPGAs constituted a sizable part of the work. Some special techniques needed to be used there too, to achieve the required radiation tolerance. The system has been demonstrated to work in several laboratory and beam tests, and now we are waiting to see it in action when the LHC will start running in the autumn 2008.

Alexander [T.] Vogelsang, secrétaire de l'Intérieur [gouvernement des Etats-Unis] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58594

[2 phot. de Zuckmantel (Cuckmantl) par J. Springer et Josef Fietz, phot. à Freiwaldau (Fryvaldov), don Alexander Jawornicki en 1889]

Donateur : Jawornicki, Alexandre (18..-19..?)

27-8-20, circuit de la Sarthe, motos Douglas (équipe) [Alexander, Isodi, Kickam] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60713

26-8-20, circuit de la Sarthe, Alexander sur Douglas : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60718

The link between extracurricular activities and academic achievement for youth in grades 5 and 7 /

This study examined the link between involvement in extracurricular activities and academic success for 504 youth in grades 5 and 7, using the first-year survey data from a longitudinal study conducted by Youth Lifestyle Choices-Community University Research Alliance (YLC-CURA). Specifically, the study investigated whether a linear or curvilinear relation existed between extracurricular activities and academic achievement for both in- and out-of-school activities. It was hypothesized that stress may be a possible mediator in the link between extracurricular activities and achievement Results indicated that students in grades 5 and 7 were involved in club and sport activities both inside and outside of school at fairly equal fi-equencies, with a mean frequency of approximately once a month. The hypothesis that a positive relation j between in- and out-of-school extracurricular activities and achievement was supported. The hypothesis that a curvilinear relation would exist between extracurricular activities and achievement was only supported for out-of-school activities. This finding supports the argument that too much or too little involvement in out-of-school activities is related negatively to a student's academic success; however, a moderate amount of involvement appears to be positive. The hypothesis that there would be a relation between involvement in extracurricular activities and stress level for both in-school and out-ofschool activities was not supported. Results were discussed in terms of educational implications and community resources for extracurricular activities.

Hugh Alexander Papers, 1811-1816 [photocopy]

Hugh Alexander, b. 1780 arrived in Niagara shortly after his birth. He attended school and later apprenticed as a clerk. In 1797 he was granted 200 acres of land in Bertie township and became a merchant and trader in Fort Erie. He was the owner of a sailing vessel, the Chippawa, which he used to transport goods in the area. The ship was lost and/or confiscated as a result of War of 1812 skirmishes on Lake Erie. By 1812 Hugh Alexander was in business together with his brother Ephraim. The Alexander’s storehouse, store and house were burned by the British military when they abandoned Fort Erie ahead of the invading American military in late May 1813. At the time of the burning, Hugh Alexander was engaged as a Lieutenant with the 3rd Lincoln Militia. Prior to this Hugh Alexander had established a second mercantile in Stamford, opposite the green. Misfortune was to strike at this location as well when the British military abandoned the whole of the Niagara area to the invading American forces and the Stamford location was looted. After the end of the hostilities Alexander went on to rebuild his storehouse in Fort Erie and to re-establish his store in Stamford. Hugh Alexander died on November 2, 1817 and is buried in the Stamford Presbyterian Cemetery. Source: George A. Seibel, The Niagara Portage Road: 200 Years 1790-1990. Niagara Falls: City of Niagara Falls, 1990, p. 259-262.