Regularly varying probability densities

The convolution of regularly varying probability densities is proved asymptotic to their sum, and hence is also regularly varying. Extensions to rapid variation, O-regular variation, and other types of asymptotic decay are also given

Human impact on limestone pavement

[cat] Els paviments calcaris de les Illes Britàniques forneixen interessants exemples de l’activitat humana com a agent de canvi geomorfològic. Aquest article contempla la historia de la influencia humana en els paviments calcaris, especialment a l’Anglaterra nord-occidental, examina danys recents, i discuteix les accions realitzades per protegir aquestes formes paisatgístiques tan belles corn fascinants. Han estat diverses les activitats que han afectat els paviments, i la importància de les activitats individuals ha canviat amb el temps. Darrerament la pressió s'ha incrementat i els organismes conservacionistes s'han interessat pel problema per tal de protegir els paviments de nous estralls. Durant els darrers 30 anys, molts pocs paviments calcaris de les Illes Britàniques han deixat d'esser afectats per agressions o alteracions, i alguns han patit molt seriosament.[eng] The limestone pavements of the British Isles provide an interesting example of human activity as an agent of geomorphological change. This paper looks at the history of human influences on limestone pavements, especially in northwestern England, examines recent damage, and discusses the actions being taken to protect these fascinating and beautiful landforms. The activities which have affected the pavements have been varied, and the importance of any individual activity has changed over time. In recent decades the pressures have increased and conservation bodies have become concerned with the problem in order to protect pavement sites from further damage. Very few pavement sites in the British Isles have been unaffected by damage or alteration in the past 30 years, and come have suffered very severely

Polynesian medical researches

This thesis embodies a portion of certain researches into the primitive medicine of the Polynesians and other races inhabiting the islands of Polynesia, Mikronesia.and Melanesia, or Australasia, which I have made during the past ten years. The work was commenced while studying medicine at the University of New Zealand, and continued in Australia and this country. Polynesian medical-lore generally, is a subject which has failed to attract the attention of medical men, or at any rate that of the medical investigator, compiler, or theorist. Doubtless one ' reason why this attempt may claim to be the first of its kind, is, that such studies, being for the most part historical, cannot well be studied in the islands: themselves, the natives in their semi-civilised and often demoralised state having forgotten most of their ancient mythology, traditions, and medical-lore. Records of these are to be found often only in such works as are preserved in national libraries, as that in the British Museum, or the Bibliothbque Nationale in Paris; the colonial libraries not possessing many of the earlier published and rarer works, which' are to be found in the above mentioned institutions. The average colonial physician., if questioned concerning the literature of Polynesian medicine, would doubtless reply - there is no such literature. And this is, in the main, true; there is no book dealing especially with the subject, but in the numerous works "by missionaries, adventurers, travelers, colonists, colonial medical officers, in fact scattered through the whole of the literature of Polynesia and Australia; we find occasional references, often meagre and vague, concerning the native medical beliefs and customs. This literature is like a vast desert, in which the cases of medical information are small, few,and far between. During a period of several months spent at the British Museum Library, I was able to search through all the works to be found there on Australasia Polynesia,and Mikronesia, many of the best of them being by French medical men in the colonial service, I and a number of rare and valuable Government publications. The Polynesians commenced to spread over the islands of the Pacific about the first century B.C. Their exact origin is unknown, and the admixture of several stocks is to be found in the peoples of the parts to the West, the pure blooded Polynesians, the finest of all these dark skinned races, "being distributed over the eastern islands of Polynesia and in New Zealand. The medical customs of these peoples differ widely from those of India or China, and in many respects are analagous to those of the Egyptians and Assyrians. The practices of the American Indians are the nearest akin to those of the Polynesians, and this is in accordance with the theory that the Auto-chthons of America are of Polynesian origin. We I cannot speak of Polynesian medicine as a uniform whole, but as a series of separate developments, each j isolated group working out for itself a more or less complex method of dealing with disease. There was very little intercourse between the different islands and no written language, hence the isolation was almost absolute. Polynesian medicine may be studied from many aspects; in the first place we have the native superstitious customs and beliefs, their sorcerers, their wizards, seers, disease makers, and medicine men or tohungas, with their practices of conjuring, mesmerism, hypnotism, raising the dead, soul-expelling and soul-entrapping, their complex and varied dealing in the black-arts, their aerial flights and subterranean wanderings, and many other remarkable manifestations. We find surgeons, masseuses, and compounders of native simples. Their spirit-world teems with supernatural beings, great and small, powerful, hideous, wicked, as well as beneficent gods, demi-gods and ghosts. These hosts are the active agents in producing, and often in curing, disease, and frequently take up their abode in the numerous fetishes with which we are so familiar in all our museums. They had no idols. Their treatment of disease often consisted in nothing more than elaborate ceremonies of propitiation and invocation of such disease demons. We have given numerous instances of the incantations and charms used in such rites. Their bodily mutilations, often barbarous and cruel, are of great scientific interest, not only to the student of medicine, but also to the anthropologist and philosopher. The curious customs of couvade, and the self-induced, and rapidly fatal, melancholia,or fatalism, are of great interest. Their practice of performing post mortem i examinations for the discovery of evidences of disease show a distinct advance from the pure disease theories demon: of etiology, as also do the operations of Tocolosi or Cocolosi, and the Hervey Island custom of removing the dark "blood from the umbilical cord, in all of which there is to be found, I believe, the first dawn of a humoral pathology. Finally, information concerning the exact distribution of the various diseases in these regions, and the definition of the prevailing diseases in each group of islands is becoming necessary, owing to the enormous expansion of the British Empire, and the gradual spread of Europeans over these islands. Of great importance, too, is such knowledge to the medical officer about to enter the Polynesian branch of the colonial service, to the medical missionaries preparing for work among these cannibals and savages, for in many parts there are still thousands existing in their savage state,and to the colonists also, the subject is not devoid of interest. As a preliminary contribution to the study of this primitive medicine and to the geographical, historical, and tropical pathology of Polynesia I submit these pages

Auto-tail dependence coefficients for stationary solutions of linear stochastic recurrence equations and for GARCH(1,1)

We examine the auto-dependence structure of strictly stationary solutions of linear stochastic recurrence equations and of strictly stationary GARCH(1, 1) processes from the point of view of ordinary and generalized tail dependence coefficients. Since such processes can easily be of infinite variance, a substitute for the usual auto-correlation function is needed

Correlation of Mixture Temperature Data Obtained from Bare Intake-manifold Thermocouples

A relatively simple equation has been found to express with fair accuracy, variation in manifold-charge temperature with charge in engine operating conditions. This equation and associated curves have been checked by multi cylinder-engine data, both test stand and flight, over a wide range of operating conditions. Average mixture temperatures, predicted by the equations of this report, agree reasonably well with results within the same range of carburetor-air temperatures from laboratories and test stands other than the NACA

Torsion Tests of Tubes

This report presents the results of tests of 63 chromium-molybdenum steel tubes and 102 17st aluminum-alloy tubes of various sizes and lengths made to study the dependence of the torsional strength on both the dimensions of the tube and the physical properties of the tube material. Three types of failure are found to be important for sizes of tubes frequently used in aircraft construction: (1) failure by plastic shear, in which the tube material reached its yield strength before the critical torque was reached; (2) failure by elastic two-lobe buckling, which depended only on the elastic properties of the tube material and the dimensions of the tube; and (3) failure by a combination of (1) and (2) that is, by buckling taking place after some yielding of the tube material

Mentoring Future Biologists via the Internet

Mentoring has a long tradition, reaching as far back as 1000 B.C. It continues to be practiced today in both educational and corporate settings. The process is typically established to help a protégé grow and develop new skills and attitudes. But science students in lower socioeconomic areas rarely have the opportunity to interact with mentors face-to-face. This is particularly true if the students are located in a rural setting, since most corporate scientists and their research facilities are concentrated in a few urban areas of the country. Few college students can travel to these sites as part of their college study, and few scientists have the leisure to travel to colleges and universities to interact with students there. If such contact were possible, students would be exposed to a much wider range of perspectives on scientific and professional issues. The E-Mentoring program was designed to overcome some of these difficulties. Electronic mentoring, or telementoring, involves the use of computer-mediated communications (like e-mail or computer conferencing systems) to support a mentoring relationship when a face to-face relationship would be impractical.The E-Mentoring program provided biology students from two historically minority universities in North Carolina with opportunities to interact and develop relationships with corporate scientists, to expand their learning horizons, and to use technology in a meaningful way. To provide a meaningful context for electronic mentoring for students, the project was integrated within appropriate biology courses, one undergraduate and one graduate. For most students and mentors, e-mentoring was a pleasant experience, but there was no immediate important impact. It is possible that the impact of the relationship may be more fully appreciated upon later reflection. For a few students, the program was unsuccessful They never developed a relationship with their mentors, and so the only benefit they received was the introduction and use of a new technological communication tool. Recommendations for future e-mentoring programs are provided