HST and ground-based eclipse observations of V2051 Ophiuchi: Binary parameters

We report on high-speed eclipse photometry of the dwarf nova V2051 Oph while it was in a low brightness state, at B ~ 16.2 mag. In comparison to the average IUE spectra, the ultraviolet continuum and emission lines appear reduced by factors of, respectively, ~4 and ~5. Flickering activity is mostly suppressed and the lightcurve shows the eclipse of a compact white dwarf at disc centre which contributes ~60 per cent of the total light at 3900--4300 A. We use measurements of contact phases in the eclipse lightcurve to derive the binary geometry and to estimate masses and relevant dimensions. We find a mass ratio of q= 0.19+/-0.03 and an inclination of i= 83+/-2 degrees. The masses of the component stars are M_1 = 0.78+/-0.06 M_dot and M_2 = 0.15+/-0.03 M_dot. Our photometric model predicts K_1 = 83+/-12 km/s and K_2= 435+/-11 km/s. The predicted value of K_1 is in accordance with the velocity amplitude obtained from the emission lines after a correction for asymmetric line emission in the disc is made (Watts et al. 1986). The secondary of V2051 Oph is significantly more massive than the secondaries of the other ultra-short period dwarf novae. V2051 Oph is probably a relatively young system, whose secondary star had not enough time to evolve out of thermal equilibrium.Comment: 16 pages, 7 postscript figures, coded using MNRAS latex style. To appear in Monthly Notices of the Royal Astronomical Society. Revised version with changes in section 4.3. For related papers and files see ftp://fsc01.fsc.ufsc.br/pub/bap and http://www.fsc.ufsc.br/~astr

Desempenho da Fixação Biológica de Nitrogênio em Cultivares de Feijão-caupi Recomendadas para Roraima.

bitstream/item/68070/1/DOC-45-2010-ID-80.pd

Bactérias Diazotróficas Endofíticas em Cultivares de Milho em Áreas de Cerrado e Mata no Estado de Roraima.

bitstream/item/53429/1/DOC-43-2010-ID-82-1.pd

REALITY SHOW BIG BROTHER DALAM PERSPEKTIF GENRE DAN OTHER CLASSIFICATIONS

Reality show is a television program that presents real events in everyday life. With the number of reality shows that appear on TV favored by the public, for example Uya is Kuya, still another world, termehek-mehek, So the more loss of ideas and justify any means to attach importance to the rating. Reality show displays a fake reality to dredge advertising alias profit. The reality show that appears on TV is not only concerned with rating, but also can incorporate moral values. The reality show program, “Big Brother” shows the daily activities of the participants and of course uses surveillance cameras. Big Brother is included in a reality show that is full of engineering and does not fit reality because it has a storyline that has been conceptualized by TV stations. The real thing of the event is the games or games and the unreal is the story of the story of the participants. The phrases that are often pronounced in this event are the participants or the so-called housemates. Although some viewers really like the Big Brother show, but what is displayed does not match the reality that exists. Although by using fact frills, but still there are still being engineered by the event editor. We should be wise to see an event program. Do not just accept it, but we must also be critical in responding

Levantamento de rizóbios isolados de nódulos de caupi cultivado em amostras de solos do cerrado do Estado do Piauí.

Cultivo de plantas iscas. Isolamento de nódulos, carcterização dos isolados. Resultados e discussão. Referências bibliográficas. Anexo 1. Anexo 2.bitstream/CNPAB-2010/27392/1/doc125.pd

Primer registro de parasitismo del federal (Amblyramphus holosericeus) por parte del especialista Tordo pico corto (Molothrus rufoaxillaris)

Screaming Cowbird (Molothrus rufoaxillaris) is highly specialized parasitizing only three species, making records of new hosts very informative. During 2017 we studied nesting success on roadsides in Argentine Pampas. Fifty-seven nests (46%) belonged to the known host Brown-and-yellow Marshbirds (Pseudoleistes virescens). Four nests belonged to Scarlet-headed Blackbird (Amblyramphus holosericeus); one contained a Screaming Cowbird nestling that fledged with two of the host. We discuss similarities and differences among the Scarlet-headed Blackbird and old hosts. More studies are needed to confirm the regular parasitism of Scarlet-headed Blackbird by Screaming Cowbird, and to better understand their high specificity in host selection.El Tordo Pico Corto (Molothrus rufoaxillaris) es altamente especialista parasitando solo a tres especies de aves, lo que hace que registros de nuevos hospedadores sean muy informativos. Durante 2017 estudiamos el éxito de nidificación en bordes de camino en la región Pampeana de Argentina. Cincuenta y siete nidos (46%) pertenecieron al hospedador ya conocido Pecho Amarillo (Pseudoleistes virescens). Cuatro nidos pertenecieron al Federal (Amblyramphus holosericeus); uno contenía un pichón de Tordo Pico Corto que abandonó el nido como volantón junto con dos pichones del hospedador. Discutimos similitudes y diferencias entre el Federal y viejos hospedadores. Mayores estudios son necesarios para confirmar el parasitismo regular del Federal por parte del Tordo Pico Corto, y para comprender mejor su alta especificidad en la selección de hospedadores.Fil: Mermoz, Myriam Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Depalma, Daniela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Charnelli, Emilio M.. Museo de Ciencias Naturales Tuyu Mapu; ArgentinaFil: Zilli, Carla Giannina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentin

Caracterização genética de rizóbios capazes de nodular feijão-caupi isolados de solos do estado de Roraima.

Considerando as características nutricionais e de rusticidade, o feijão-caupi [Vigna unguiculata (L.) Walp.], constitui-se uma das leguminosas de grande importância para o Estado de Roraima e seu cultivo pode ser encontrado em diversas áreas da região. É uma leguminosa que pode se beneficiar do processo de fixação de nitrogênio, podendo receber parte do nitrogênio necessário ao seu desenvolvimento, através da simbiose com bactérias denominadas de rizóbios. Desta forma, o objetivo deste trabalho foi caracterizar genotipicamente 31 bactérias isoladas de solo de mata e cerrado no Estado de Roraima capazes de nodular feijão-caupi. Para isto, com o DNA das bactérias extraídos, o gene 16S rRNA foi amplificado, purificado e sequenciado. A partir do sequenciamento pode-se observar similaridade acima de 99% entre as bactérias e os gêneros Bradyrhizobium, Rhizobium e Agrobacterium. Também foi possível observar que das 31 bactérias sequenciadas, 20 são pertencentes ao gênero Bradyrhizobium e 11 ao gênero Rhizobium, e estes foram encontrados tanto em áreas de mata quanto de cerrado