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This study presents new petrologic and thermochronologic information from the Fairbanks district of east central Alaska that indicate a complex metamorphic and structural history for the western Yukon–Tanana terrane. Garnet–biotite and garnet–pyroxene thermometry and jadeite barometry yield prograde temperatures and pressures for the Chatanika eclogite (523°C, 14–15 kbar (1 kbar = 100 MPa)). Cooling from peak eclogitization is estimated from [sup 40] Ar/[sup 39] Ar single grain geochronology at ~210–180 Ma. Secondary white mica ages of 140–115 Ma along the fault contact between eclogite and underlying lower amphibolite-facies rocks constrain the age of the event that placed the Chatanika eclogite over the Fairbanks schist. Based on observations from field mapping and diamond drill samples, we interpret this structural contact as a thrust fault. Garnet–biotite mineral pairs are reset by as much as 200°C within this fault zone. Biotite and white mica ages of ~100–110 Ma, combined with Jurassic amphibole ages in Fairbanks schist samples, indicate the Fairbanks schist and Chatanika eclogite cooled through biotite and white mica argon closure temperatures in the early Cretaceous. Intrusion of mid-Cretaceous, calc-alkalic, gold-related granitic plutons in the Fairbanks district are evidenced by loss of radiogenic argon in many of the [sup 40] Ar/[sup 39] Ar age fractions. Eocene basalt is visible in six widely separated localities within the eastern part of the Fairbanks district. However, the pervasiveness of a 50 Ma resetting event in samples as far as 30 km from present day basalt localities indicates the Eocene flows were either deposited throughout the Fairbanks area or are associated with large plutons at depth.Cette étude présente de nouvelles informations pétrologiques et thermochronologiques provenant du district de Fairbanks du centre-est de l'Alaska qui indiquent un historique métamorphique et structural complexe pour le terrane occidental de Yukon–Tanana. La thermométrie grenat–biotite et grenat–pyroxène et la barométrie de la jadéite ont donné des températures et des pressions progrades pour l'éclogite de Chatanika (523 ºC, 14–15 kbar, (1 kbar = 100 MPa)). Le refroidissement à compter du sommet de la formation de l'éclogite est estimé être survenu à ~210–180 Ma, selon de la géochronologie [sup 40] Ar/[sup 39] Ar sur grain unique. Des âges de mica blanc secondaire, de 140–115 Ma, le long du contact de la faille entre l'éclogite et les roches sous-jacentes au faciès inférieur des amphibolites, restreignent l'âge de l'événement qui a placé l'éclogite de Chatanika au-dessus du schiste de Fairbanks. Selon des observations de cartographie sur le terrain et des échantillons de carottes de forage au diamant, nous interprétons ce contact structural comme une faille de chevauchement. Les ensembles minéraux grenat–biotite ont subi des rajustements atteignant 200 ºC à l'intérieur de cette zone de failles. Des âges ~100–110 Ma pour la biotite et le mica blanc, combinés à des âges jurassiques pour l'amphibole dans les échantillons de schiste de Fairbanks, indiquent qu'en se refroidissant, le schiste de Fairbanks et l'éclogite de Chatanika ont traversé les températures de fermeture sur l'argon de la biotite et du mica blanc au Crétacé précoce. L'intrusion, au Crétacé moyen, de plutons granitiques, calco-alcalins et reliés à l'or dans le district de Fairbanks, est mise en évidence par la perte d'argon radiogénique dans plusieurs des fractions d'âge [sup 40] Ar/[sup 39] Ar. On voit affleurer un basalte datant de l'Éocène dans six localités grandement distancées dans la partie est du district de Fairbanks. Toutefois, l'omniprésence d'un rajustement de 50 Ma dans des échantillons aussi éloignées que 30 km des emplacements actuels de basalte indique que les écoulements à l'Éocène ont été déposés dans toute la région de Fairbanks ou qu'ils sont associés à de grands plutons en profondeur.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This Article analyzes the development and complexities of the antitrust state action doctrine and the Local Government Antitrust Act as these doctrines apply to both "municipalities" and private entities. The restructuring of a public hospital is used as a model to facilitate the antitrust analysis. The restructuring model, which typically involves the leasing of a hospital facility by a public entity to a private nonprofit corporation, offers the unique opportunity to compare the different standards employed under the state action doctrine and the Local Government Antitrust Act. As a practical matter, the Article provides a framework for public hospital to evaluate the impact of corporate restructuring on its antitrust liability exposure and to develop strategies to minimize antitrust risks. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the review by Elliot S. Gershon to the Müller-Hill's book on the nefarious eugenics movement in Nazi Germany by Franz Kallmann in the previous issue.

The replacement of animal testing using dogs for the registration of plant protection products requires a long-term step-by-step procedure. The first goal should be to achieve international agreement on using only one single study in dogs. This would result in a significant short-term reduction of the use of dogs for this purpose. The competent working groups both in the EU and the United States EPA have declared this to be their intended aim. In this context, the 90-day study is to be the preferred study from the scientific as well as the animal welfare points of view. It is proposed to set up an international expert task force within the next 12 months, which should seek to initiate a process of international harmonization of the testing requirements following the example of the International Conference of Harmonization of Technical Requirements for Medical Products, ICH. The goal should be to achieve international agreement on only one single study with dogs within the next 2 to 3 years. In addition, other valid scientific procedures, with which the use of dogs for testing can be reduced, should be critically assessed. A complete replacement of the use of dogs for plant protection product testing is suggested to take place at a later stage. This may be achieved by either deriving safety threshold values by applying a safety factor to chronic NOAEL values obtained in studies using rats for those groups of substances, for which there is evidence that the dog is the more sensitive species, or by combining the chronic rat study with other animal tests stipulated for the registration of pesticides.