3 research outputs found
Trace anomaly of the conformal gauge field
The proposed by Bastianelli and van Nieuwenhuizen new method of calculations
of trace anomalies is applied in the conformal gauge field case. The result is
then reproduced by the heat equation method. An error in previous calculation
is corrected. It is pointed out that the introducing gauge symmetries into a
given system by a field-enlarging transformation can result in unexpected
quantum effects even for trivial configurations.Comment: 9 pages, LaTeX file, BI-TP 93/3
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans â anteaters, sloths, and armadillos â have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
Electric telegraphy in the pages of âO Institutoâ, Journal of Coimbraâs Academy
Analisamos os avanços da telegrafia elĂ©ctrica e da telegrafia sem fios no mundo e, em particular, em Portugal, com base em artigos da revista O Instituto, publicada pelo Instituto de Coimbra, uma sociedade cientĂfica, fundada em 1852, que reuniu um vasto leque de personalidades das ciĂȘncias e artes nacionais. Passamos em revista os principais artigos sobre a telegrafia: o artigo de JosĂ© Maria de Abreu de 1855, publicado menos de um mĂȘs depois da adjudicação das primeiras linhas telegrĂĄficas em Portugal; o parecer da Faculdade de Filosofia da Universidade de Coimbra sobre as deliberaçÔes do Congresso e ConferĂȘncias de Paris para determinação das unidades elĂ©ctricas, onde esteve Santos Viegas, Presidente do Instituto; e o artigo de Ălvaro Silva Basto de 1903 sobre a telegrafia sem fios. Uma menção especial Ă© feita ao artigo de Adriano Paiva BrandĂŁo de 1878 sobre telescopiaWe analyze the advances of electric telegraphy and of wireless telegraphy in the world and, in particular, in Portugal, based on articles of the periodical O Instituto, published by the Instituto de Coimbra, a scientific society, founded in 1852, that gathered many Portuguese personalities of science and arts. We review the main articles on telegraphy: the paper by JosĂ© Maria de Abreu in 1855, less than a month after the adjudication of the first telegraphic lines in Portugal; the assessment by the Philosophical Faculty of the University of Coimbra on the deliberations of the Congress and Conferences of Paris for the unification of electric units, where Santos Viegas, the President of the Coimbra's Institute was present; and the paper of Ălvaro Silva Basto in 1903 on wireless telegraphy. Special mention is made to the article by Adriano Paiva BrandĂŁo in 1978 on telescop