Revista de Biología Tropical Vol.31 (2)

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  • Ítem
    Dermatoglifos en dos poblaciones indígenas Guaymí de Costa Rica
    (Revista de Biología Tropical 31(2) p.268-257, 1983-04-27) Quesada, Misael; Barrantes Mesén, Ramiro
    Twenty-three palmar and digital dermatogliphic characters were examined in two Guaymi Amerindian populations, Abrojo and Limoncito, in southeastern Costa Rica. Derrnatogliphs were analyzed in relation to sex, bilaterality or assymetry and differences in pattern frequencies between localities. The sample included 134 males and 127 females in two groups, according to their ethnic and linguistic origin: Western Guaymi (Movere), from Limoncito and Abrojo, and Eastern Guaymi (Murire or Buglere) from Limoncito. When compared with other Amerindian groups, the Guaymi presented a very low finger pattern average, as well a low total ridge count. The Movere subgroup, showed similarities among different patterns both in Limoncito and Abrojo. However there are significant differences between the Murire and Movere groups in relation to the ridge count (ab; bc),atd angle; frequency of designs at the interdigital zone 4; bilaterality; and sex. The results obtained confirm the existence of a marked evolutionary divergence between the two groups.
  • Ítem
    Análisis ultraestructural de membranas de glóbulos grasos lácteos de calostro y leche humana
    (Revista de Biología Tropical 31(2):245-250, 1983) Akahori, Hiroshi; Hernández Chavarría, Francisco
    Lacteous fat globules with their membranes from human milk and calostrum were studied by scanning and transmission electron microscopy. The first appear as spheroidal structures with some irregularities on the surface. Under the transmission electron microscope these irregularities are composed of islets from a material morphologically similar to cytoplasm, and with structures that resemble a fragment of rugose endoplasmic reticulum. The membranes in specimens fixed immediately after secretion are tri-layered, similar in appearance to those of a single membrane, but in samples fixed between two and four hours after secretion the details are unclear. Through freeze-etching, the laminar aspect of the fat globules is observed.