Regularization Schemes and Higher Order Corrections

I apply commonly used regularization schemes to a multi-loop calculation to examine the properties of the schemes at higher orders. I find complete consistency between the conventional dimensional regularization scheme and dimensional reduction, but I find that the four dimensional helicity scheme produces incorrect results at next-to-next-to-leading order and singular results at next-to-next-to-next-to-leading order. It is not, therefore, a unitary regularization scheme.Comment: References added and typographical errors correcte

The Four Dimensional Helicity Scheme Beyond One Loop

I describe a procedure by which one can transform scattering amplitudes computed in the four dimensional helicity scheme into properly renormalized amplitudes in the 't Hooft-Veltman scheme. I describe a new renormalization program, based upon that of the dimensional reduction scheme and explain how to remove both finite and infrared-singular contributions of the evanescent degrees of freedom to the scattering amplitude.Comment: 20 page

Two-Loop Virtual Corrections to Drell-Yan Production at order alpha_s alpha^3

The Drell-Yan mechanism for the production of lepton pairs is one of the most basic processes for physics studies at hadron colliders. It is therefore important to have accurate theoretical predictions. In this work we compute the two-loop virtual mixed QCD x QED corrections to Drell-Yan production. We evaluate the Feynman diagrams by decomposing the amplitudes into a set of known master integrals and their coefficients, which allows us to derive an analytical result. We also perform a detailed study of the ultraviolet and infrared structure of the two-loop amplitude and the corresponding poles in epsilon.Comment: 20 pages, 3 figure

The Influence of Position on the Apparent Position, Size and Form of Angles

The angles were drawn with black india ink on white cards 10 cm. square and exhibited to the observer in the Michotte tachistoscope. The observer reproduced the angles with a pencil on a piece of white paper, 10 cm. square. The position of the reproduced legs of the angle was then measured. The size of the angle and the position of the bisector were computed subsequently. Position was measured in terms of a circular protractor placed in a vertical plane and rotated until 0° was uppermost. The protractor was also turned so as to read in the clockwise direction. Twelve sizes of angles were used

Telehealth Activities in RCHE

Telehealth refers to a variety of mediated healthcare delivery and supporting methodologies, including: Synchronous provider/patient consultations through teleconferencing (telemedicine, teleoncology, telecardiology, etc.) Store and forward diagnostic imaging (teleradiology) Home-based patient monitoring (home telecare/tele homehealth) Distance education for healthcare professionals Etc

Diet Composition and Activities of Elk on Different Habitat Segments in the Lodgepole Pine Type, Uinta Mountains, Utah

The biweekly diets of tame elk (Cervus canadensis nelsoni) were established on a species dry-weight basis for different habitat segments of the lodgepole pine (Pinus contorta) type, Principal species in the diets (5% or more) on each habitat segment were generally composed of preferred species. However, some highly abundant but non-preferred species took on principal dietary status, whereas some preferred species, scarce in the vegetation, contributed less than 5 percent to diets. Forbs contributed most to total consumption; grasses and sedges were the second largest contributors. Browse appeared to be of limited importance, but mushrooms had special significance in forested habitat segments. Preference changes were evident as forb species matured. Consumption rates were significantly higher in habitat segments having greater species diversity and forage density. The time tame elk spent grazing, ruminating, lying, grooming, traveling, standing, drinking, and playing was referenced to specific habitat segments in which each activity occurred. One thousand and eight hours of individual elk activity were observed over a series of six 24-hour periods. Wet meadows, dry meadows, clearcuts. and revegetated roads were preferred as grazing sites, while mature and stagnated forests were clearly non-preferred. Wet meadows, revegetated roads, and mature forest were preferred for resting and non-grazing activities. The distribution of pellet groups deposited by tame elk was determined with reference to habitat segment and form of activity at the time of deposition. Pellet group distributions thus obtained, were strongly unrepresentative of relative time spent in various habitat segments

No Oil for the Lamps of China?

Chinese naval and strategic planners fear, and their Western counterparts seem to believe, that a maritime blockade could interrupt or significantly impede China’s energy supplies in a limited war. But probably it could not, and thinking it could is dangerous for everyone

Diamond Jenness (1886-1969)

Canada's most distinguished anthropologist, Dr. Diamond Jenness, formerly Chief of the Division of Anthropology, National Museums of Canada, and Honorary Associate of the Arctic Institute of North America, died peacefully at his home in the Gatineau Hills near Ottawa on 29 November, 1969. He was one of that rapidly-vanishing, virtually extinct kind - the all round anthropologist, who, working seriously, turned out first-class publications in all four major branches of the discipline: ethnology, linguistics, archaeology, and physical anthropology. One must also add a fifth: applied anthropology, a fitting designation for the series of monographs on Eskimo administration in Alaska, Canada, and Greenland which he wrote after his retirement and which were published by the Arctic Institute of North America. ... [In response to an invitation to join Stefansson Arctic Expedition and study Eskimos for three years, Jenness found himself a member of the Southern Party with an assignment to study the Copper Eskimos around Coronation Gulf. These plans were interrupted due to the presence of sea ice.] On 30 September, Stefansson, with his secretary Burt McConnell, Jenness, two Eskimos, and the expedition's photographer G.H. Wilkins (later Sir Hubert Wilkins), left the Karluk near the mouth of the Colville River to hunt caribou and lay in a supply of fresh meat when it had become apparent that the ship, immobilized in the ice, could proceed no further. With two sleds, twelve dogs and food for twelve days the party set out for the mainland, but they never saw the Karluk again, for a week or so later the unfortunate vessel began her final drift westward. This was the inauspicious beginning of Jenness' arctic career. Few young anthropologists have faced such difficulties in beginning field-work in a new and unfamiliar area; yet none, surely, has emerged from the test with a more brilliant record of work accomplished. ... Jenness' first winter's field-work on the Arctic coast of Alaska led to [an] impressive list of publications ... conducted under conditions that many an ethnographer would have found intolerable. ... Scarcely a hint of these personal experiences of his first winter in the Arctic will be found in Jenness' anthropological writings. They were reserved for his retrospective volume Dawn in Arctic Alaska (1957) which he wrote while on a Gugenheim scholarship in 1954, some years after his retirement. ... Jenness' first year in the Arctic ended in July 1914 when the Expedition's schooners left Camden Bay and sailed eastward to Dolphin and Union Strait where he was to meet with another though very different, Eskimo people named by Stefansson the Copper Eskimos, most of whom, before Stefansson worked among them in 1910-1911, had never seen a white man. ... To obtain a faithful picture of the life of the Copper Eskimos Jenness chose an approach that in those days was not often employed by ethnologists. He entered into their life directly, as one of them. He attached himself to an Eskimo family and became the adopted son of Ikpukhuak, one of the foremost hunters and respected leaders of the Puivlik tribe of southwest Victoria Island, and his wife Higilak (Ice House), who was not only proficient in the ordinary and burdensome duties of an Eskimo wife but was also a shaman in her own right, a talent that saved Jenness from a local murder charge. Jenness lived with these people in their snow houses in winter and skin tents in summer, observing and recording the vastly different modes of life according to season. ... Jenness' researches extended far beyond Coronation Gulf and the arctic coast westward. ... Jenness always disclaimed being an archaeologist, yet he made two discoveries that are fundamental to an understanding of Eskimo prehistory - discovery of the Dorset culture in the eastern Arctic, and of the Old Bering Sea, earliest stage of the maritime pattern of Eskimo culture that later spread from northern Alaska to Canada and Greenland to form the principal basis for modern Eskimo culture. ... And so much more. In 1926, Jenness succeeded Edward Sapir as Chief Anthropologist of the National Museum of Canada. ... He developed the Antiquities Legislation that has been so important for the protection of archaeological resources in the Northwest Territories. ... Between 1962 and 1968 the Arctic Institute of North America published his admirable five volumes on Eskimo administration in Alaska, Canada, and Greenland. These monographs reflect his durable and compassionate concern for Canadian Indians and Eskimos and in them one can find much of the advice that he, for so many decades, provided the Canadian Government. ... [Jenness' accomplishments extend beyond the realm of anthropology and his reputation was both national and international. For his services in the field of anthropology, particularly in connection with the Indian and Eskimo population of Canada, he was appointed a Companion of the Order of Canada.

Logan Medallist 7. Appinite Complexes, Granitoid Batholiths and Crustal Growth: A Conceptual Model

Appinite bodies are a suite of plutonic rocks, ranging from ultramafic to felsic in composition, that are characterized by idiomorphic hornblende as the dominant mafic mineral in all lithologies and by spectacularly diverse textures, including planar and linear magmatic fabrics, mafic pegmatites and widespread evidence of mingling between coeval mafic and felsic compositions. These features suggest crystallization from anomalously water-rich magma which, according to limited isotopic studies, has both mantle and meteoric components. Appinite bodies typically occur as small (~2 km diameter) complexes emplaced along the periphery of granitoid plutons and commonly adjacent to major deep crustal faults, which they preferentially exploit during their ascent. Several studies emphasize the relationship between intrusion of appinite, granitoid plutonism and termination of subduction. However, recent geochronological data suggest a more long-lived genetic relationship between appinite and granitoid magma generation and subduction.Appinite may represent aliquots of hydrous basaltic magma derived from variably fractionated mafic underplates that were originally emplaced during protracted subduction adjacent to the Moho, triggering generation of voluminous granitoid magma by partial melting in the overlying MASH zone. Hydrous mafic magma from this underplate may have ascended, accumulated, and differentiated at mid-to-upper crustal levels (ca. 3–6 kbar, 15 km depth) and crystallized under water-saturated conditions. The granitoid magma was emplaced in pulses when transient stresses activated favourably oriented structures which became conduits for magma transport. The ascent of late mafic magma, however, is impeded by the rheological barriers created by the structurally overlying granitoid magma bodies. Magma that forms appinite complexes evaded those rheological barriers because it preferentially exploited the deep crustal faults that bounded the plutonic system. In this scenario, appinite complexes may be a direct connection to the mafic underplate and so its most mafic components may provide insights into processes that generate granitoid batholiths and, more generally, into crustal growth in arc systems.Les corps d’appinite sont une suite de roches plutoniques, de composition ultramafique à felsique, qui se caractérisent par de la hornblende idiomorphe comme minéral mafique dominant dans toutes les lithologies et par des textures spectaculairement diverses, y compris des fabriques magmatiques planaires et linéaires, des pegmatites mafiques et de nombreuses preuves de « mingling », mélange hétérogène, des compositions mafiques et felsiques de même âge. Ces caractéristiques suggèrent une cristallisation à partir d'un magma anormalement riche en eau qui, selon un nombre limité d’études isotopiques, possède à la fois des composants mantelliques et météoriques.Les corps d’appinite se présentent généralement sous la forme de petits complexes (~ 2 km de diamètre) mis en place à la périphérie des plutons granitoïdes et généralement adjacents aux principales failles crustales profondes qu'ils exploitent préférentiellement lors de leur ascension. Plusieurs études soulignent la relation entre l'intrusion d'appinite, le plutonisme granitoïde et l’arrêt de la subduction. Cependant, des données géochronologiques récentes suggèrent une relation génétique de plus longue durée entre la génération d'appinite et de de magma granitoïde et la subduction.L'appinite peut représenter des aliquotes de magma basaltique hydraté dérivées de sous-plaques mafiques à fractionnement variable qui ont été initialement mises en place lors d'une subduction prolongée adjacente au Moho, déclenchant la génération de magma granitoïde volumineux par fusion partielle dans la zone MASH sus-jacente. Le magma mafique hydraté de cette sous-plaque peut avoir remonté et s’être accumulé et différencié à des niveaux crustaux moyens à supérieurs (environ 3 à 6 kbar, 15 km de profondeur) et avoir cristallisé dans des conditions de saturation en eau. Le magma granitoïde s'est mis en place par impulsions lorsque des contraintes transitoires ont activé des structures favorablement orientées qui sont devenues des conduits pour le transport du magma. L'ascension du magma mafique tardif, cependant, est entravée par les barrières rhéologiques créées par les corps magmatiques granitoïdes structurellement sus-jacents. Le magma qui forme des complexes d'appinite a échappé à ces barrières rhéologiques car il a exploité préférentiellement les failles crustales profondes qui délimitaient le système plutonique. Dans ce scénario, les complexes d'appinite peuvent être une connexion directe à la sous-plaque mafique et ainsi ses composants les plus mafiques peuvent fournir des informations sur les processus qui génèrent des batholites granitoïdes et, plus généralement, sur la croissance crustale dans les systèmes d'arc