Population dynamics of the gall inducer Eriogallococcus isaias (Hemiptera: Coccoidea: Eriococcidae) on Pseudobombax grandiflorum (Malvaceae)

Eriogallococcus isaias Hodgson and Magalhães is a Neotropical species of gall-inducing scale insect (Coccoidea: Eriococcidae), whose phenological synchrony with its host plant, Pseudobombax grandiflorum, is fundamental to the maintenance of its population. Furthermore, E. isaias is unusual among gall-inducing Eriococcidae because its galls are not sexually dimorphic and are induced by the second-instar nymphs. We studied the life cycles of the host plant and the galling insect, and followed the development of the insects and the structure of the gall. The results showed that gall induction is synchronous with leaf flushing, and that the galls and leaves mature concomitantly. Males have a 36–48-day life cycle within the gall, whereas females have a 75–100-day life cycle.     

Effect of insulin on immunological phagocytosis by macrophages

Summary It was shown that, in physiological concentrations, insulin enhances, in vitro, the immunological phagocytosis of sensitized sheep erythrocytes by cultured mouse peritoneal macrophages. Insulin seems to stimulate macrophage phagocytosis as a cholinomimetic agonist by increasing the intracellular levels of cyclic GMP.Acknowledgments. This investigation was supported by a grant from the National Council for Cientific and Tecnological Development (CNPq), Rio de Janeiro, Brazil.     

DNA damage defines sites of recurrent chromosomal translocations in B lymphocytes

Recurrent chromosomal translocations underlie both haematopoietic and solid tumours. Their origin has been ascribed to selection of random rearrangements, targeted DNA damage, or frequent nuclear interactions between translocation partners; however, the relative contribution of each of these elements has not been measured directly or on a large scale. Here we examine the role of nuclear architecture and frequency of DNA damage in the genesis of chromosomal translocations by measuring these parameters simultaneously in cultured mouse B lymphocytes. In the absence of recurrent DNA damage, translocations between Igh or Myc and all other genes are directly related to their contact frequency. Conversely, translocations associated with recurrent site-directed DNA damage are proportional to the rate of DNA break formation, as measured by replication protein A accumulation at the site of damage. Thus, non-targeted rearrangements reflect nuclear organization whereas DNA break formation governs the location and frequency of recurrent translocations, including those driving B-cell malignancies.     

聚合物的一维振子链模型

一维聚合链可以用一维振子链来模拟.其中联接振子而组装链的键可以分为主键和次键.一维振子链的非线性过程要受主键或次键的非线性过程所控制,本文讨论了在主键或次键的非线性作用下所引起的一维振子链的非线性过程.在一定条件下,我们可以得到解析的孤子解.     

Cytogenetics of South American akodont rodents (Cricetidae). V. Segregation of chromosome No. 1 polymorphism inAkodon molinae

Summary Akodon molinae is polymorphic with 2n=42, 43, 44, where the metacentric autosome No. 1 is homologous to 2 acrocentrics 1a and 1b. Matings between 2n=43 heterozygotes 1/1a, 1b gave a surplus of 1/1 offspring, a moderate reduction of heterozygous and a strong reduction of homozygous 1a, 1b/1a, 1b offspring. The latter type also has a highly reduced fertility.This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas, the Comisión de Investigaciones Científicas de la Provincia de Buenos Aires and the Organización de Estados Americanos.     

Heart norepinephrine concentration after chronic alcohol ingestion in the rat

Summary The effect of long-term alcohol ingestion on the norepinephrine concentration of the heart was investigated in rats. The alcoholic animals showed a highly significant increase in cardiac norepinephrine concentration as compared with the corresponding controls. It is further suggested that continued exposure to high levels of norepinephrine may play a role in the development of cardiomyopathy in chronic alcoholism.     

Anastácio da Cunha and the concept of convergent series

Summary Anastácio da Cunha's definition of convergent series (Principios Mathematicos, Lisboa 1790, p. 106) was analysed by the Portuguese mathematician J. Vicente Gonçalves (Análise do Livro VIII dos Principios Mathematicos de José Anastácio da Cunha, Congresso do Mundo Português Vol. XII, Tomo I, Lisboa 1940, 123–140) and more recently by the historian A. P. Youschkevitch (J. A. da Cunha et les fondements de l'analyse infinitésimale Revue d'Histoire des Sciences Tomme XXVI, N. 1, 1973, 9–22). This latter author contests Gonçalves' claim to the effect that Cunha anticipated in his definition the well known criteria of convergence commonly attributed to A. Cauchy. However, Youschkevitch's otherwise deeper analysis is based primarily on a French translation of Principios published in Bordeaux in 1811. In this paper, that translation is shown to be misleading at crucial places. Cunha's definition is further analysed, and an interpretation in terms of the potential infinity is proposed which results in a redress of Cunha's originality in this matter.     

RELATIVE IMPORTANCE OF WOOD DENSITY AND CARBOHYDRATE CONTENT ON PULPING YIELD AND PRODUCT QUALITY

INTRODUCTIONPulp quality depends on wood quality and pulping process conditions. Wood quality is a result of forestry management practices and a combination of genetic, physical, anatomical and chemical characteristics of the wood [35]. Eucalypt pulps are desired for printing and writing and for tissue paper grades due to their anatomical and chemical characteristics. It has been shown that wood density exerts significant influence on pulp quality [21]. This parameter, together with volum…     

Potentiation of bradykinin action on smooth-muscle by cysteine

Zusammenfassung Die Wirkung von Bradykinin, aber nicht von Angiotensin I und II auf das isolierte Meerschweinchenileum und den Uterus der Ratte wird durch Cystein verstärkt. Die Sensibilisierung der glatten Muskulatur ist auf die Hemmung der Kininase, die sich in den Geweben jener Organe befindet, durch Cystein zurückzuführen. Fragmente von Uterus oder Heum von Tieren, deren hintere Extremitäten unter Druck mit Tyrode durchströmt und zur vollkommenen Ausblutung gebracht wurden, inaktivieren das Bradykinin, wenn sie damit inkubiert werden. Diese Inaktivierung kann durch Vorbehandlung der Organe mit Cystein verhindert werden.