4,104 research outputs found
Criação de ovinos deslanados em área de cerrado do Amapá.
Visando incentivar a ovinocultura no Amapá, a Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA, atraves da sua Unidade de Pesquisa de Ambito Territorial - UEPAT de Macapá, vem desenvolvendo no Campo Experimental do Cerrado, município de Macapá, experimento a fim de avaliar o comportamento produtivo e reprodutivo de ovinos deslanados da raça Santa Ines em pastagem de quicuio da Amazônia (Brachiaria humidicola).bitstream/item/64921/1/AP-1987-criacao-ovinos-deslanados-cerrado-amapa.pd
Hyperbolic and satellite Lorenz links obtained by twisting
A Lorenz link is equivalent to a T-link, which is a positive braid built by
concatenating torus braids of increasing size. When each torus braid except the
largest is obtained by full twists, then the T-link can be described as the
Dehn filling of a parent link. In this paper, we completely classify when such
parent links are hyperbolic. This gives a classification of the geometry of
T-links obtained by full twists when the amount of twisting is large, although
the bound on the number of required twists is not effective. We also present
effective results on hyperbolicity for two families of T-links obtained by
twisting, even when the number of twists is small. Finally, we identify
families of satellite T-links obtained by half-twists.Comment: 21 pages, 5 figures. Version 2: added corollary 1.2, and other
changes to expositio
Análise do comportamento in vitro de explantes foliares de pequizeiro (Caryocar brasiliense camb.) através de RAPD.
xEdição de resumos do 7º Congresso Brasileiro de Fisiologia Vegetal, Brasília, 1999
Age-related changes in ocular mucosal tolerance: Lessons learned from gut and respiratory tract immunity
The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation-free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune-based ocular surface disorders, which could be related to an age-related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.Fil: Galletti, Jeremías Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: de Paiva, Cintia S.. Baylor College of Medicine; Estados Unido
Variação genética entre procedências de seringueira.
Plantas de seringueira (Hevea spp.) com um ano de idade originadas de sementes de seringais nativos dos estados do Acre, Mato Grosso e Rondonia, envolvendo 36 amostras de 14 locais distintos, foram avaliadas para diametro de caule, altura de planta e numero de lancamentos. A incidencia de doencas foi avaliada quando as plantas tinham 17 meses de idade. O delineamento utilizado foi o latice triplo 6 x 6, com 50 plantas por parcela, no espacamento de 4,0 m x 4.0 m. As procedencias RO/CM/10, MT/C/04 e MT/C/06 apresentaram-se como as mais vigorosas, enquanto que AC/S/08 e AC/S/11 demonstraram pobre vigor nessa fase de desenvolvimento. As procedencias de seringais nativos localizadas em areas de varzeas estao apresentando melhor vigor. Em geral, as originadas de Rodonia apresentam-se mais vigorosas que as do Acre e Mato Grosso. As procedencias originadas de Rondonia, Mato Grosso e Acre apresentaram proporcionalmente maior contribuicao sobre a variacao estimada dentro de procedendia em cada Estado para as caracteristicas que determinam vigor de planta. Os parametros utilizados para avaliacao da variabilidade genetica na populacao detectaram alta variabilidade aproveitavel na selecao. Todas as procedencias foram altamente infectadas pelo Microccyclus ulei, ao passo que a incidencia de Thanatephorus cucumeris e Colletotrichum gloeosporioides foi menos intensa e mais variavel
Photoassociative ionization of Na inside a storage ring
Motivated by recent interest in low dimensional arrays of atoms, we
experimentally investigated the way cold collisional processes are affected by
the geometry of the considered atomic sample. More specifically, we studied the
case of photoassociative ionization (PAI) both in a storage ring where
collision is more unidirectional in character and in a trap with clear
undefinition of collision axis. First, creating a ring shaped trap (atomotron)
we investigated two-color PAI dependence with intensity and polarization of a
probing laser. The intensity dependence of the PAI rate was also measured in a
magneto-optical trap presenting equivalent temperature and density conditions.
Indeed, the results show that in the ring trap, the value of the PAI rate
constant is much lower and does not show evidences of saturation, unlike in the
case of the 3D-MOT. Cold atomic collisions in storage ring may represent new
possibilities for study.Comment: 5 pages, 5 figures; Accepted by Optics Communicatio
Potencial de sequestro do carbono em solo pela incorporação de carvão das cascas de frutos da castanha-do-Brasil.
Utilizou-se um ensaio de respirometria para estimar o potencial de sequestro de carbono no solo pela incorporação de carvão das cascas de frutos da castanha-do-brasil. Os carvões produzidos a 350ºC, 450ºC e 550°C foram adicionados ao solo contendo microorganismos e paralelamente em meio abiótico, cujos frascos foram vedados para quantificação da evolução do carvão em CO2. O ensaio foi monitorado por 182 dias verificando-se taxas decrescentes de CO2, cujas curvas apresentaram formato logarítmico. Observou-se que no processo abiótico a formação de CO2 é superior quando comparada ao processo biótico, e que o carvão produzido a 550°C apresenta maior taxa de mineralização que os demais carvões. Além disso, verifica-se que todas as amostras de carvão possuem estabilidade no solo a longo prazo
Extracting Mathematical Concepts with Large Language Models
We extract mathematical concepts from mathematical text using generative
large language models (LLMs) like ChatGPT, contributing to the field of
automatic term extraction (ATE) and mathematical text processing, and also to
the study of LLMs themselves. Our work builds on that of others in that we aim
for automatic extraction of terms (keywords) in one mathematical field,
category theory, using as a corpus the 755 abstracts from a snapshot of the
online journal "Theory and Applications of Categories", circa 2020. Where our
study diverges from previous work is in (1) providing a more thorough analysis
of what makes mathematical term extraction a difficult problem to begin with;
(2) paying close attention to inter-annotator disagreements; (3) providing a
set of guidelines which both human and machine annotators could use to
standardize the extraction process; (4) introducing a new annotation tool to
help humans with ATE, applicable to any mathematical field and even beyond
mathematics; (5) using prompts to ChatGPT as part of the extraction process,
and proposing best practices for such prompts; and (6) raising the question of
whether ChatGPT could be used as an annotator on the same level as human
experts. Our overall findings are that the matter of mathematical ATE is an
interesting field which can benefit from participation by LLMs, but LLMs
themselves cannot at this time surpass human performance on it.Comment: 13 pages, 4 figures, presented to the 14th MathUI Workshop 202
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