Formação das castas no gênero Melípona (Illiger, 1806)

The present work is destinated to prove that the castes : workers and queens, in Melipona bees are due to genetic factors and not to differences in food. 2) Material used: Hives of Melipona quadri-fasciata anthidioides (Lep. 1836), M. schenki schenki (Gribodo, 1893), M. fasciata rufiventris (Lep. 1836), M. quadri-fasciata vicina (Lep. 1836), M. marginata marginata (Lep. 1836), Apis mellifera (L. 1758). 3) It should be pointed out that in Melipona bees there are no royal cells for the queens, but all the cells are of the same size independently of being destinated for workers, queens or drones. The numerous queens which are born are killed soon after emerging from their cells. 4) Changes of feeding in quality and in quantity caused no variation of castes. The only variable factor is the size, which becomes bigger when the bee is well nourished. 5) The offsprings of 5 hives were examined : 3 of M. quadri-fasciata anthidioides (n.o 1, n.o 2 and n.o 3), 1 of M. quadri-fasciata vicina (n.o 4) and 1 of M. marginata marginata (n.o 5). Combs of about 40 cells were taken into laboratory and the type of bee registered immediately after emerging. The results of the counts were: BOX COMB WORKER QUEEN PERCENTAGE Σ X2 to 12,5% Nº 1 1th 69 8 10,4% 0, 3139 " 1 2nd 144 18 11,1% 0, 2856 " 2 1th 52 8 13,3% 0, 0384 " 3 1th 45 10 18,2% 1, 6736 " 4 1th 56 4 6,7% 1, 8686 " 4 2nd 29 4 12,1% 0,00432 Σ X2 to 25% " 5 1th 34 14 29,2% 0,44444 "5 2nd 83 27 24,5% 0, 0121 In the 4 first boxes there is a percentage of 11,63% queens and in the last there is a percentage of 25,95%. 6) These percentages are very near two genetical ratios: 12,5% or 7:1, and 25% or 3:1, which correspond to a trifactorial and a bifactorial back-cross. Carrying out a X² test no significant deviations were found ( X² to 12,5% and to 25% and table 1 to 4). 7) We suppose that the formula for the queen in the first case (11,65%) is: AaBbCc. Since the Melipona bees are arrhenotokous hymenopteres, the drones are haploid and may have any one of the following eight formulas, corresponding to the gonic segregation of the queem : ABC, ABc, Abc, Abc, AbC, aBC, aBc, abC, abc. Anyone combination of these males with the queen will give a segregation of 7 workers to 1 queen, since there is always only one triple heterozygote among the eight possible segregates (table 5). 8) In order to explain the second case, it is suffient to assume that in this species there are only two pairs of factors, the queen being the double heterozygote : AaBb, while the drones may have any one of the following constitutions: AB, Ab, aB and ab. Workers are again all diploids which are homozygous for one or both factors, for instance: AABB, AABb, AaBB, aaBb, AAbb, etc. (table 6). 9) It is suggested that the genus Melipona is an intermediary type between the solitary bees, where all females are fertile independently of their feeding, and the genera Apis and Trigona, where without special feeding all females are born sterile, while only specially fed females develop into fertile queens. 10) No speculations are put forward with regards to the evolutionary mechanism which may have been responsible for the development of the genetical determination of castes in Melipona, since it seems advisable point to extend the studies to other insects with complicated caste systems.

Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama

Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed.

Morfologia externa dos estágios imaturos de heliconíneos neotropicais: I. Eueides isabella dianasa (Hübner, 1806)

External morphology of the immature stages of neotropical heliconians: I. Eueides isabella dianasa (Hübner, 1806). The external features of egg, larva and pupa of Eueides isabella dianasa (Hübner, 1806) (Lepidoptera, Nymphalidae, Heliconiinae) are described and illustrated, based upon light and scanning electron microscopy.

Los límites de la obligatoriedad escolar en Buenos Aires, 1884-1915

En este artículo pretendemos enriquecer el marco explicativo que inquiere en las razones del hiato entre el trazado ideal y la constitución efectiva del sistema público de instrucción en Argentina en el periodo que va desde la sanción de la Ley 1.420 hasta la entrada en la década de 1910. Nos interesará dejar asentado que tal distancia no dependió únicamente de las limitaciones materiales con las que se enfrentaron las autoridades escolares, o de las decisiones de los padres con respecto de la asistencia de sus hijos a la escuela, sino que la misma estuvo enraizada en un elemento más profundo, del orden de las representaciones, que desde muy temprano funcionó como un impedimento para la realización de la vocación educativa pretendidamente ecuménica de las élites argentinas. De hecho, las posturas educativas universalistas convivieron con ostras que rechazaban la posibilidad e incluso la conveniencia de que todos los niños se educaran en escuelas comunes, aparente contradicción que atravesó los discursos y las prácticas de casi todos los miembros de las élites, incluyendo los de los adalides de la "educación popular". A través del análisis y de la puesta en relación de la ley de Educación común (Ley n.1.420/1884) y la Ley de Reglamentación del Trabajo de Mujeres y Niños (Ley n.5.291/1907), exploraremos cómo se fueran estableciendo los criterios que desde temprano determinaron que "niños" podrían convertirse en alumnos, y cuáles no.

Paul Otlet: um pioneiro da organização das redes mundiais de tratamento e difusão da informação registrada

Estudo da obra de Paul Otlet, com ênfase no Princípio Monográfico, uma de suas principais contribuições para a constituição da documentação e da ciência da informação e predecessora da idéia de hipertexto. Sua obra Traité de Documentation: le livre sur le livre: théorie et pratique, publicada em 1934, antecipa muitas das idéias hoje adotadas sobre a organização de redes internacionais de cooperação para tratamento e troca de informações documentadas. Nessa obra, Otlet define o campo da documentação e sistematiza teorias, métodos e técnicas para organizar o conhecimento registrado e distribuí-lo. Revisitar a obra de Otlet é fundamental para compreender muitos aspectos teóricos, metodológicos e epistemológicos que construíram o campo da documentação e da ciência da informação.

Jean-Paul Marat (1743-1793), cientista e tradutor de Newton

Although Jean Paul Marat (1743-1793) is known as a political activist and as a founder of the controversial journal L'Ami du Peuple during the French Revolution, an important period of his life was spent as a medical practionner, and as a scientist. In 1765 he went to England, where he remained for eleven years mostly dedicated to medical practice and publications on that subject and on political and moral questions. Returning to France in 1776 he iniciated his researches on fire, electricity and light, that lasted practically until the French Revolution. In 1787 he published a translation of Newton's Opticks. In this article we describe in some detail his medical and scientific practice giving particular emphasis to his experiments on optics and to his theory about colors which strongly departs from newtonian theory, fully accepted by the French scientific community of the time.

Caracterização do mel produzido por espécies de Melipona Illiger, 1806 (apidae: meliponini) da região nordeste do Brasil: 1. Características físico-químicas

Thirty three honey samples produced by four Melipona species from different areas of the State of Bahia, were analyzed with the aim to determine their physico-chemical characteristics, contributing to the establishment of standards for quality control. The majority of the average values for physico-chemical parameters fulfilled the quality criteria established by the Brazilian and international Legislations for Apis honey, except for moisture content, which afforded higher values. Concerning the high number of samples wich did not fit the limits for reducing sugars, it is necessary to define minimum values in order to characterize Melipona honeys, as well as criteria for use of diastasic activity.