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| Registros recuperados: 98.244 | |
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| Piza Jor.,S. de Toledo; Zamith,Adiel P. L.. |
| In order to test Piza's conclusions regarding the dicentricity of Hemipteran chromosomes, two species of bugs of the family Coreidae, namely, Anasa sp. and Leptoglossus stigma (Herbst), are studied in the present paper. a) Anasa sp. - The male of this species has 21 chromosomes, that is, 20 pairs of autosomes and a single sex chromosome. The latter divides equationally in the first division of the spermatocytes and passes undivided to one cell in the second division. In this it moves with its longer axis parallelly to the spindle axis and shows fibrillar connections with both poles. Special attention was paid to the behavior of the chromosomes in the anaphase of the spermatogonia. As it was previously stated (Piza 1946 and 1946a) with regard to other... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100006 |
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| Graner,E. A.. |
| 1) Um estudo sobre o modo de crescimento de alones tetraplóides de mandioca Vassourinha Paulista, obtido experimentalmente por meio da colquicina, foi feito em comparação ao crescimento de clones diplóides da mesma variedade. Três outros clones da mandiosa amargosa foram também incluidos na análise para comparação. As observações foram feitas nas hastes da primeira ramificação de cada planta e podem ser resumidas como segue: (Quadros n.°s 1 e 2). a) comprimento: Dos 6 clones tetraplóides analisados, 5 (n.°s 1, 3, 6, 5 e 7) tiveram um comprimento bem menor que o dos clones controles diplóides, mostrando assim serem plantas menores. Um único clone tetraplóide (n.° 15) teve um comprimento menor, porém com a média não estatisticamente diferente da média do... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100007 |
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| Torres,A. Di Paravicini. |
| Beginning an experiment on protein comparisons, at the Poultry and Rabbitry Departament of the Esc. Sup. de Agricultura "Luiz de Queiroz", University of S. Paulo, four groups of growing chicks were submitted during 40 days to the following rations: basal part - 50 corn meal and 30 wheat bran, variable part - R1 - 10 tankage and 10 peanut meal, R2 - 10 tankage and 10 cottonseed meal, R3 - 7 peanut meal, 7 cocoanut meal and 7 cottonseed meal, R4 - 5 tankage, 5 peanut, 5 cocoanut and 5 cottenseed meal, R2 and R3 gave results which may be considered as equal and inferior than those obtained with the others, R4 being the best one. The statistical analises showed no significant differences. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100024 |
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| Torres,A. Di Paravicini; Bergamin,Armando. |
| Os autores realizaram uma pesquisa afim de verificar o conceito de que a couve-flor exerce um papel deprimente sobre a postura das galinhas. Para isso organizaram 20 grupos de 10 aves cada, onze dos quais da raça Rhode Island Red e 9 da Light Sussex. Desses grupos, 7 ocupavam parques gramados e os restantes parques sem grama. As aves permaneceram por 10 dias sob o regime verde de couve-flor. Houve dificuldade na análise dos resultados devido a diferenças genéticas entre as duas raças utilizadas. Das conclusões parciais constantes do texto deste trabalho, parece que a couve-flor exerce um efeito deprimente sôbre a postura, mas essa crença não chega a ser confirmada clarament na análise estatística dos dados obtidos. A conclusão final a que os AA. chegaram é... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100025 |
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| Piza Jor.,S. de Toledo. |
| The main facts presented in this paper may be summarized as follows: 1) Corizus (Liorhyssus) hyalinus (Fabr.) has primary spermatocytes provided with 6 autosomal tetrads, one pair of microchromosomes and one sex chromosome. 2) The two microchromosomes present in this species sometimes appear at the primary metaphase as an unequal pair of minute elements. In the secondary spermatocytes the unique microchromosome present may be in the limit of visibility or entirely invisible. This invisibility may be partly due to a loss of colourability. 3) The sex chromosome divides transversely in the first division of the spermatocyte, passing undivided to one pole in the second one. In the latter it becomes fusiform in the beginning of anaphase revealing in this manner... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100008 |
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| Kerr,Warwick E.. |
| 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.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100015 |
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| Piza Jor.,S. de Toledo. |
| The male of Eneoptera surinamensis (Orthoptera-Eneopteridae) is provided with 9 chromosomes, that is, with 3 pairs of autosomes and 3 sex chromosomes. Spermatogonia. - The autosomes of the spermatogonia are of the same size and U-shaped. One of the sex chromosomes approximately equalling the autosomes in size is telocentric, while the other two are much larger and V-shaped. One of the latter is smaller than the other. The sex chromosomes as showed in Figs. 1 and 2 are designated by X, Yl and Y2, X being the larger V, Yl the smaller one and Y2 the rod-shaped. Primary spermatocytes. - Before the growth period of the spermatocytes all the three sex chromosomes are visible in a state of strong heteropycnosis. X is remarkable in this stage in having two long... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100005 |
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| Gurgel,J. T. A.. |
| 1) O caráter presença de espinhos nos frutos da mamoneira é determinado por um par de fatores dominantes SS, sendo a forma recessiva ss, inerme. A interação alélica nao é bem intermediária, havendo uma predominância do fator S. Êste resultado foi anteriormente constatado por HARLAND (7), PEAT (8), DOMINGO (2), GURGEL (4) e FERNANDES (3). 2) A constatação da segregação 1 SS : 2 Ss : 1 ss foi feita após extensivas contagens de espinhos, tanto na forma paternal, como também no Fl, F2 e "back-cross". Por essas contagens foi verificado que existem variedades com números diferentes de espinhos, podendo-se distinguir dois tipos: variedades que têm muitos espinhos, com uma média aproximada de 170 espinhos por fruto e variedades que têm um número médio de espinhos,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100014 |
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| Piza Jor.,S. de Toledo. |
| Spermatogonial chromosomes of Pachylis laticornis and Pachylis pharaonis begin anaphasic movement with both ends turned toward the same pole, maintaining this form util they reach the poles. This is a proof that they are provided with one kinetochore at each end. Additional proof for a longitudinal division of each longitudinal half of the anaphase chromosomes of the primary sper- matocytes is presented against the idea of a previous end-toend pairing at metaphase. The longitudinal split of the chromosomes of the secondary spermatocytes which used to be considered as tertiary split is therefore a true secondary split. The heterochromosome in both species passes undivided to one pole in the first division of the spermatocyte. In Pachylis laticornis it... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100004 |
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| Graner,E. A.. |
| The effect of carotenoid pigments on the egg yolk color was studied in this paper. Three types of maize of known genetical constitution were used: Cateto, with deep orange endosperm; Armour, with yellow-orange endosperm and Cristal, with white endosperm. The carotenoid pigments of the two colored maizes were analysed: the total and both the active parts in relation to vitamin A and the zeaxanthin part showed to be practically double in the deep orange corn. The color of the yolk was orange when the ration had the deep orange corn and yellow in the case of the yellow-orange corn. The increase in shade was proportional to the amount of pigment present in the grains. If green feeds is added to the ration with white corn, the yolk becomes yellow or orange,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100026 |
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| Bergamin,Armando. |
| The author reports in this paper the results obtained in one experiment with wet an dry mash on the growing of chickens. The experiment started with two groups of 50 Sussex bred each, one receiving dry and other wet mash. The observations were continued in another four groups of 25 chickens each, two of Rhod Island Red bred and two of Sussex bred, both receiving dry and wet mash. The chickens were weight every 10 days and the differences obtained proved to be not significant statistically. Both dry and wet mash were equally good but wet mash is much more dificult to give to the chickkens than the dry one. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1946 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761946000100027 |
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| Registros recuperados: 98.244 | |
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