735 research outputs found

    AlteraçÔes morfo-fisiologicas em tecidos de pessegueiro e relação com a morte precoce de plantas.

    Get PDF
    bitstream/CPACT/570/1/boletim_56.pd

    An Infrared Study of the Circumstellar Material Associated with the Carbon Star R Sculptoris

    Get PDF
    The asymptotic giant branch (AGB) star R Sculptoris (R Scl) is one of the most extensively studied stars on the AGB. R Scl is a carbon star with a massive circumstellar shell (Mshell∌7.3×10−3 M⊙M_{shell}\sim 7.3\times10^{-3}~M_{\odot}) which is thought to have been produced during a thermal pulse event ∌2200\sim2200 years ago. To study the thermal dust emission associated with its circumstellar material, observations were taken with the Faint Object InfraRed CAMera for the SOFIA Telescope (FORCAST) at 19.7, 25.2, 31.5, 34.8, and 37.1 ÎŒ\mum. Maps of the infrared emission at these wavelengths were used to study the morphology and temperature structure of the spatially extended dust emission. Using the radiative transfer code DUSTY and fitting the spatial profile of the emission, we find that a geometrically thin dust shell cannot reproduce the observed spatially resolved emission. Instead, a second dust component in addition to the shell is needed to reproduce the observed emission. This component, which lies interior to the dust shell, traces the circumstellar envelope of R Scl. It is best fit by a density profile with n∝rαn \propto r^{\alpha} where α=0.75−0.25+0.45\alpha=0.75^{+0.45}_{-0.25} and dust mass of Md=9.0−4.1+2.3×10−6 M⊙M_d=9.0^{+2.3}_{-4.1}\times10^{-6}~M_{\odot}. The strong departure from an r−2r^{-2} law indicates that the mass-loss rate of R Scl has not been constant. This result is consistent with a slow decline in the post-pulse mass-loss which has been inferred from observations of the molecular gas.Comment: 10 pages, 10 figures, accepted to Ap

    Umidade ponderal em tecidos de pereira durante o perĂ­odo de dormĂȘncia sob condiçÔes de inverno ameno.

    Get PDF
    O objetivo deste trabalho foi avaliar a umidade ponderal (UP) em diferentes tecidos das cultivares de pereira Kieffer (Pyrus communis) e Housui (Pyrus pyrifolia), durante a dormĂȘncia, em condiçÔes de inverno ameno. Foram avaliadas plantas do pomar experimental da Embrapa Clima Temperado, Pelotas, RS. Utilizouse o delineamento experimental inteiramente casualizado, em esquema fatorial 3x4x5, que consistiu em trĂȘs tecidos (gema, casca e lenho), quatro porçÔes de ramos (terminal, mediana, axial e esporĂ”es) e cinco datas de coleta, em 2005 (1/7, 3/8, 6/9, 23/9 e 13/10), com parcelas subdivididas e trĂȘs repetiçÔes. Houve aumento na UP do lenho na cultivar Kieffer atĂ© a metade da dormĂȘncia, com subsequente redução a partir desta fase, o que pode ser atribuĂ­do ao aumento na UP observado nas gemas apĂłs satisfação da exigĂȘncia em frio e superação de dormĂȘncia. Na cultivar Housui, a insatisfação da exigĂȘncia em frio, associada Ă  ocorrĂȘncia de altas temperaturas durante o inverno, refletiu-se na redução da UP e na desidratação das gemas durante a dormĂȘncia. A dinĂąmica da ĂĄgua em tecidos de pereira Ă© diretamente influenciada pelo acĂșmulo de frio hibernal e depende da exigĂȘncia em frio de cada cultivar

    English-Spanish Cognates in the Charlotte Zolotow Award Picture Books: Vocabulary, Morphology, and Orthography Lessons for Latino ELLs

    Get PDF
    English-Spanish cognates are words that are orthographically and semantically identical or nearly identical in English and Spanish as a result of a common etymology. Because of the similarities in the two languages, Spanish-dominant Latino English Language Learners (ELLs) can be taught to recognize English cognates thereby increasing their bilingualism and bi-literacy for these two languages. There are over 20,000 English-Spanish cognates, many of the academic vocabulary words. Despite their vast educational potential, however, cognates are typically excluded as a word category in the language arts curriculum, thus denying Latino ELLs of a resource for acquiring English-Spanish bilingualism and bi-literacy. English-Spanish cognates may be distinguished from non-cognate words by their rule-governed morphological and orthographic structures. To capitalize on the inherent differences between cognates and non-cognates, the present manuscript presents morphological and orthographic strategies that can be used to teach Latino ELLs to recognize the rich cognate vocabulary found in picture books, specifically, those books which have been cited as Charlotte Zolotow Award winners and honor books. Through these strategically-designed language activities revolving around the read-alouds of the Zolotow Award books, teachers can introduce Latino ELLs to cognates in the early primary school years to encourage their development of bilingualism and bi-literacy
    • 

    corecore