28,561 research outputs found
Publications of the planetary biology program for 1975: A special bibliography
The Planetary Biology Program of the National Aeronautics and Space Administration is the first and only integrated program to methodically investigate the planetary events which may have been responsible for, or related to, the origin, evolution, and distribution of life in the universe. Research supported by this program is divided into the seven areas listed below: (1) chemical evolution, (2) organic geochemistry, (3) life detection, (4) biological adaptation, (5) bioinstrumentation, (6) planetary environments, and (7) origin of life. The arrangement of references in this bibliography follows the division of research described above. Articles are listed alphabetically by author under the research area with which they are most closely related. Only those publications which resulted from research supported by the Planetary Biology Program and which bear a 1975 publication date have been included. Abstracts and theses are not included because of the preliminary and abbreviated nature of the former and the frequent difficulty of obtaining the latter
Hydrogen maser oscillation at 10 K
A low temperature atomic hydrogen maser was developed using frozen atomic neon as the storage surface. The maser has been operated in the pulsed mode at temperatures from 6 K to 11 K and as a self-excited oscillator from 9 K to 10.5 K
Entra a desobediência civil e o estado de exceção permanente
A comunicação propõe a quebra de um pensamento jurídico dogmático acerca da desobediência civil. Sabendo que há vícios de Estado que jamais se corrigem, abordaremos a desobediência civil como uma alternativa que o cidadão tem contra ações despóticas acobertadas por um estado de exceção tornado permanente, no qual direito e garantias fundamentais são total ou parcialmente suspensos
Two dimensional XXZ-Ising model on square-hexagon lattice
We study a two dimensional XXZ-Ising on square-hexagon (4-6) lattice with
spin-1/2. The phase diagram of the ground state energy is discussed, shown two
different ferrimagnetic states and two type of antiferromagnetic states, beside
of a ferromagnetic state. To solve this model, it could be mapped into the
eight-vertex model with union jack interaction term. Imposing exact solution
condition we find the region where the XXZ-Ising model on 4-6 lattice have
exact solutions with one free parameter, for symmetric eight-vertex model
condition. In this sense we explore the properties of the system and analyze
the competition of the interaction parameters providing the region where it has
an exact solution. However the present model does not satisfy the \textit{free
fermion} condition, unless for a trivial situation. Even so we are able to
discuss their critical points region, when the exactly solvable condition is
ignored.Comment: 5 pages, 5 figure
Utilização da multiplicação rápida na propagação da mandioca (Manihot esculenta Crantz).
A mandioca (Manihot esculenta Crantz) é uma espécie rústica, que possui a capacidade de produzir em regiões de solos pobres e com escassez de água.Entretanto, ela possui certas características que dificultam a sua propagação em larga escala num curto intervalo de tempo. Uma dessas características é a sua baixa taxa de multiplicação. Cada planta de mandioca pode produzir de 5 a 10 manivas de 20 cm, num período de 12 meses, ou seja, a sua taxa de propagação é de 1:5 a 1:10. A multiplicação rápida, desenvolvida pelo Centro Internacional de Agricultura Tropical (CIAT), na Colômbia, é um método simples e barato de multiplicação da mandioca. O aumento da taxa de multiplicação deve-se, em primeiro lugar, ao fato de que, as manivas para a multiplicação rápida são cortadas com duas a três gemas (2 a 5 cm, a depender da distância entre as gemas), enquanto as manivas para plantio têm cerca de sete gemas (em torno de 20 cm). E em segundo lugar, na multiplicação rápida, a maniva ao brotar, tem o broto cortado ao atingir o tamanho de 10 a 15 cm, e rebrota novamente, induzida pelas condições de umidade e temperatura elevadas do interior da câmara de propagação, enquanto na multiplicação convencional, a maniva de 20 cm é plantada no campo, e gerará no máximo quatro hastes.PDF. 055
The type of adjuvant in whole inactivated influenza a virus vaccines impacts vaccine-associated enhanced respiratory disease
Influenza A virus (IAV) causes a disease burden in the swine industry in the US and is a challenge to prevent due to substantial genetic and antigenic diversity of IAV that circulate in pig populations. Whole inactivated virus (WIV) vaccines formulated with oil-in-water (OW) adjuvant are commonly used in swine. However, WIV-OW are associated with vaccine-associated enhanced respiratory disease (VAERD) when the hemagglutinin and neuraminidase of the vaccine strain are mismatched with the challenge virus. Here, we assessed if different types of adjuvant in WIV vaccine formulations impacted VAERD outcome. WIV vaccines with a swine δ1-H1N2 were formulated with different commercial adjuvants: OW1, OW2, nano-emulsion squalene-based (NE) and gel polymer (GP). Pigs were vaccinated twice by the intramuscular route, 3 weeks apart, then challenged with an H1N1pdm09 three weeks post-boost and necropsied at 5 days post infection. All WIV vaccines elicited antibodies detected using the hemagglutination inhibition (HI) assay against the homologous vaccine virus, but not against the heterologous challenge virus; in contrast, all vaccinated groups had cross-reactive IgG antibody and IFN-γ responses against H1N1pdm09, with a higher magnitude observed in OW groups. Both OW groups demonstrated robust homologous HI titers and cross-reactivity against heterologous H1 viruses in the same genetic lineage. However, both OW groups had severe immunopathology consistent with VAERD after challenge when compared to NE, GP, and non-vaccinated challenge controls. None of the WIV formulations protected pigs from heterologous virus replication in the lungs or nasal cavity. Thus, although the type of adjuvant in the WIV formulation played a significant role in the magnitude of immune response to homologous and antigenically similar H1, none tested here increased the breadth of protection against the antigenically-distinct challenge virus, and some impacted immunopathology after challenge
Nuclear isotope thermometry
We discuss different aspects which could influence temperatures deduced from
experimental isotopic yields in the multifragmentation process. It is shown
that fluctuations due to the finite size of the system and distortions due to
the decay of hot primary fragments conspire to blur the temperature
determination in multifragmentation reactions. These facts suggest that caloric
curves obtained through isotope thermometers, which were taken as evidence for
a first-order phase transition in nuclear matter, should be investigated very
carefully.Comment: 9 pages, 7 figure
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