, Female Molothrus ater from Oklahoma at the subspecies border with M.a. obscurus were tested for their discrimination of songs from their native area and from Austin, Texas. This 400-km distance is characterized by a structural shift in the male cowbird's inclusion of the mid-song element, a structure found in the songs of Austin and the more southern M.a. obscurus populations but not in the s...

Here, we report that on six widely separated Scandinavian islands, the coal tit Parus ater has evolved morphologically in the direction of two absent competitors, the crested tit P. cristatus and the willow tit P.montanus, to the effect that it is up to 10% larger in linear dimensions than conspecifics on the adjacent Swedish mainland, where all three species coexist. The large size is genetica...

The active site of Viviparus ater (mollusc) hemocyanin was investigated using the fact that the binding of dioxygen to the binuclear copper-containing sites of hemocyanins is connected with the appearance of specific dichroic bands which are very sensitive to changes in the structrure and polarity of the environment. Oxy-Viviparus ater hemocyanin exhibits near UV and visible circular dichroism ...

This work presents the synthesis of a dialogue with two rural extension teachers who, along other, were fundamental in articulations that resulted constitution National Forum Rural Extension Teachers (Forum), namely: professora Sonia Maria Pessoa Pereira Bergamasco and professor Eros Marion Mussoi. Conducted form an interview, aimed to register understand history construction analyze its relati...

Com a chegada da pandemia Covid-19 as Tecnologias Digitais de Informação e Comunicação (TDIC) começaram ser utilizadas com maior frequência pelas instituições Assistência Técnica Extensão Rural (ATER). Atualmente, um dos principais recursos para comunicação divulgação notícias junto aos agricultores são redes sociais aplicativos mensagens eletrônicas. Este artigo se propõe identificar analisar ...

Two studies were conducted to investigate the relation between the male cowbird's (Molothrus ater ater) development of a song repertoire and the female cowbird's assessment of song potency. Male development was assayed by vocal copying and female assessment by copulatory responsiveness to song playback. The results demonstrate that males do not copy most often the particular songs that females ...

Resumo Crédito rural e assistência técnica são importantes instrumentos de estímulo à agropecuária. Mas que maneira eles têm sido utilizados pela agricultura familiar, engloba quase 80% dos estabelecimentos agropecuários brasileiros? O presente artigo, usando microdados da PNAD 2014, analisa o acesso Pessoas Potencialmente Classificadas como Agricultor Familiar (PPCAF) a programas crédito exten...

Resumo O objetivo deste estudo é apresentar experiências de reforma agrária relacionadas a regimes agroalimentares da agricultura familiar no contexto do desenvolvimento rural dos territórios Rio Grande Norte, nos períodos I e II Planos Nacionais Reforma Agrária (PNRA). A metodologia consistiu em uma pesquisa exploratória descritiva, analisando informações quantizadas das ações ATER (Assistênci...