142 research outputs found
A Hall effect thruster plume model including large-angle elastic scattering
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76556/1/AIAA-2001-3355-806.pd
Competitiveness and communication for effective inoculation byRhizobium, Bradyrhizobium and vesicular-arbuscular mycorrhiza fungi
After a short summary on the ecology and rhizosphere biology of symbiotic bacteria and vesicular-arbuscular (VA) mycorrhiza fungi and their application as microbial inocula, results on competitiveness and communication are summarized. Stress factors such as high temperature, low soil pH, aluminium concentrations and phytoalexins produced by the host plants were studied withRhizobium leguminosarum bv.phaseoli andRhizobium tropici onPhaseolus beans. Quantitative data for competitiveness were obtained by usinggus + (glucoronidase) labelled strains, which produce blue-coloured nodules. ForPhaseolus-nodulating rhizobia, a group specific DNA probe was also developed, which did not hybridize with more than 20 other common soil and rhizosphere bacteria. Results from several laboratories contributing to knowledge of signal exchange and communication in theRhizobium/Bradyrhizobium legume system are summarized in a new scheme, including also defense reactions at the early stages of legume nodule initiation. Stimulating effects of flavonoids on germination and growth of VA mycorrhiza fungi were also found. A constitutive antifungal compound in pea roots, -isoxazolinonyl-alanine, was characterized
Gravitational ultrarelativistic spin-orbit interaction and the weak equivalence principle
It is shown that the gravitational ultrarelativistic spin-orbit interaction
violates the weak equivalence principle in the traditional sense. This fact is
a direct consequence of the Mathisson-Papapetrou equations in the frame of
reference comoving with a spinning test particle. The widely held assumption
that the deviation of a spinning test body from a geodesic trajectory is caused
by tidal forces is not correctComment: 12 page
Widespread spring phenology effects on drought recovery of Northern Hemisphere ecosystems
The time required for an ecosystem to recover from severe drought is a key component of ecological resilience. The phenology effects on drought recovery are, however, poorly understood. These effects centre on how phenology variations impact biophysical feedbacks, vegetation growth and, ultimately, recovery itself. Using multiple remotely sensed datasets, we found that more than half of ecosystems in mid- and high-latitudinal Northern Hemisphere failed to recover from extreme droughts within a single growing season. Earlier spring phenology in the drought year slowed drought recovery when extreme droughts occurred in mid-growing season. Delayed spring phenology in the subsequent year slowed drought recovery for all vegetation types (with importance of spring phenology ranging from 46% to 58%). The phenology effects on drought recovery were comparable to or larger than other well-known postdrought climatic factors. These results strongly suggest that the interactions between vegetation phenology and drought must be incorporated into Earth system models to accurately quantify ecosystem resilience.X.W. was financially supported by the National Natural Science Foundation of China (grant nos. 41922001 and 42171050), the Second Tibetan Plateau Scientific Expedition and Research Program (grant no. 2019QZKK0306) and the National Key Research and Development Program of China (grant no. 2022YFF0801800). S.A.K. was supported by the US Department of Energy Environmental System Science program grant no. DE-SC0022052. A.G. is supported by the Ramon y Cajal Program of the Spanish MICINN under grant RyC2020- 030647-I, and by CSIC under grant PIE-20223AT003. W.K.S. and W.Z. were supported by the NASA Carbon Cycle and Ecosystems Program under grant 80NSSC21K1709.Peer reviewe
Enantioselective Catalytic Desymmetrization of Maleimides by Temporary Removal of an Internal Mirror Plane and Stereoablative Over-reduction: Synthesis of (R)-Pyrrolam A
A highly enantioselective (>95% ee) strategy to affect
the desymmetrization of a maleimide has been performed by
temporary attachment to an anthracene template followed by
asymmetric reduction with an oxazaborolidine catalyst. A stereoablative
over-reduction process was partially responsible for the high
levels of enantioselectivity. Exemplification of the strategy by
stereoselective functionalization and retro-Diels−Alder reaction
provided the natural product pyrrolam A
OFICINAS DO BRINCAR: UM RESGATE A INFÂNCIA POR MEIO DE JOGOS, BRINQUEDOS E BRINCADEIRAS. (relato de experiência)
A brincadeira e jogo são construções sociais e, portanto culturais. A criança ao nascer está impregnada de práticas estabelecidas nas relações com outros sujeitos, adultos e outras crianças que possibilitam o acesso aos códigos sociais estabelecidos na forma de aprendizagem social. É na brincadeira, na fantasia e posteriormente no jogo com a elaboração de regras mais complexas que a criança se apropria da organização social na qual está inserida. Como processo cultural, o acesso a brincadeira e ao jogo se dá fundamentalmente na relação com outro e com as condições de espaço, materiais e possibilidades de exploração desses elementos. Considerando a importância da brincadeira e do jogo em proposições criativas, de descobertas, elaborações ereelaborações, estamos realizando um projeto de pesquisa denominado “Oficinas do brincar: um resgate a infância por meio de jogos, brinquedos e brincadeiras”, desenvolvido com os acadêmicos da quarta fase do curso de Licenciatura em Pedagogia, do Instituto Federal Catarinense – campi Blumenau (SC), com a perspectiva de propiciar espaço de relacionamento significativo com a brincadeira, o jogo, o brinquedo e práticas corporais expressivas como elementos de acesso a cultura lúdica e, portanto de inserção num contexto social humanizador. A dinâmica do projeto compreende atividades sequenciais com os discentes, semanalmente, nos quais são utilizadas as dependências da própria instituição, que disponibiliza o espaço físico e conta com a colaboração dos estudantes ao trazerem os recursos - como brinquedos, jogos e materiais para práticas corporais e expressivas. O projeto está em fase inicial de desenvolvimento, mas vem confirmando a relevância de seus propósitos, haja visto que parte do princípio de propiciar resgate e vivências da infância, do brincar, através dos jogos, brinquedos e brincadeiras, tematizando discussões em torno da ludicidade, como processo histórico e social, capaz de proporcionar reflexão e colaborar com a formação humana pelo acesso e interação com essas formas de manifestação da cultura. Dessa forma, objetiva-se com esta oficina, propiciar espaço e oportunidades de autoconhecimento, vivências inclusivas, melhora da auto-estima, desenvolver habilidades de comunicação, expressão e interação social dos acadêmicos envolvidos no projeto com os sujeitos participantes, colaborando com a formação acadêmica dos alunos mediadores do projeto tanto no que se refere à prática pedagógica exercida sob a perspectiva de professor, intelectual-pesquisador, bem como para a comunidade envolvida, no sentido de poder recordar os jogos, brinquedos e brincadeiras de suas infâncias por meio de cantos temáticos (num estande ou sala de aula), contendo: mostra do acervo de brinquedos que fizeram parte da infância da turma; produção artesanal de brinquedos sustentáveis com matérias recicláveis; espaço do faz de conta, com oficineiros desenvolvendo atividades recreacionistas para o público visitante
DNA methylation of the IGF2/H19 imprinting control region and adiposity distribution in young adults
Możliwości zastosowania Projakościowej Metody Wartościowania Pracy w Państwowym Gospodarstwie Leśnym Lasy Państwowe
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