Male-female interaction during breeding and non-breeding seasons in Akodon azarae (Rodentia, Muridae)

Dyad encounters between male and female adults of Akodon azarae (Fischer, 1829) were analyzed by means of observational techniques in a natural closure during the breeding and non-breeding seasons. The animals were held in observation during 21 days, with daily 15-minute recordings of interindividual separation distance, relative displacements, characteristics of the male-female interaction, copulation, and construction and exclusive or shared use of nests by each pair. The couples, which bred successfully, showed, on average, the longest separation distance between male and female allowed by the closure. During the first two weeks of gestation the females exhibited more displacements than their respective mates did. The male-pregnant female encounters were significantly more aggressive than those recorded between pairs which did not breed successfully. During the non-breeding season a shorter average distance between individuals and a frequent use of nests shared by the pair were recorded. The results obtained are discussed within the framework of the social system of A. azarae.

Remarks on and descriptions of South American non-marine shells.

v.31:no.46(1951)

On some new non-marine mollusks from Colombia and Peru.

v.44:no.25(1966)

Non-marine shells from Borneo, collected by the Borneo Zoological expedition, 1950.

v.31:no.52(1951)

On non-marine shells from Northeastern Brazil and Peru.

v.37:no.10(1955)

Male external genitalia of non-prehensile tailed South American monkeys. Philip Hershkovitz.

n.s. no.73(1993)

Reproductive strategy of a non-annual rivulid in a perennial wetland

ABSTRACT Atlantirivulus riograndensis (Costa & Lanés, 2009) is a fish registered to the basin of Patos lagoon and the adjacent coastal plains in southern states of Rio Grande do Sul and Santa Catarina, Brazil, found in shallow water courses with that have large quantities of aquatic vegetation and forest edges. The objective of this study was to investigate the reproductive strategy and tactics of this species including the sex ratio, the length at first maturity, spawning type, fecundity and the possible associations among reproduction and abiotic factors. Sampling of specimens occurred in perennial wetlands within the Banhado dos Pachecos wildlife refuge, in the city of Viamão, state of Rio Grande do Sul, Brazil, which is a conservation unit that belongs to an area of environmental protection in the Pampa Biome. The capture of 30 A. riograndensis specimens per month occurred from January to December of 2012. A total of 188 females and 172 males were captured and the total sex ratio was 1:1 in the sampled population. Sexual maturity of the species occurs after 13.59 and 11.92 mm (SL) for females and males, respectively. Both a multiple spawning and a long reproductive period (since August to March) were confirmed by the presence of post-ovulatory follicles that were observed through histological analysis and the values of the gonadosomatic index in females considered spawning capable. The average absolute fecundity of the species is of 19.33 (± 6.18) vitellogenic oocytes in mature ovaries. No significant relationship was found between mean GSI and the abiotic data. Reproductive tactics presented by A. riograndensis indicate a species with an opportunistic reproductive strategy, following the pattern of other species of the Rivulidae family.

Dous phyllopodos, observados no Rio Grande do Norte

Le 19 juillet 1928 l'auteur trouva près de Natal, capitale de l'État de Rio Grande do Norte, a 5º 47' au sud de l'équateur, un nouveau Dendrocephalus qui portera le nom ornatus, dû a ses appendices caudales teints d'écarlate brillant. La femelle (Pl.1) atteint 12 mm. de longueur e contient des oeufs noirs dans sa cavité d'incubation. Le mâle, beaucoup plus robuste, atteint 16 mm. et montre, outre les caracteres sexuels, une modification extrémement compliquée des deuxièmes antennes (qui dans la planche II sont vues devant les premières). L'espèce est plus petite que les deux autres décrites de l'Amérique du Sud et se distingue facilement par les antennes du mâle. Elle fut trouvée au bord de la route dans une flaque large et profonde d'eau de pluie argileuse. Les exemplares rapportés moururent en quelques jours et la mare, lors d'une seconde visite, fut trouvé sèche. L'autre espèce, observée en 9. 7. 28 dans un étang naturel tout-près de la capitale, avait déjà été observée á Matto Grosso et en Paraguay et déterminée comme Cyclestheria hislopi BAIRD. THIELE pense que les individus de l'Amérique du Sud, pour cause de quelques petites différences, pour-raient nien former une autre espèce qu'il propose d'appeler sarsiana, mais la comparaison des desseins et descriptions avec mes exemplaires ne parait pas soutenir cette idée. Tout-de-mème la répartition connue de cette espèce est extrêmement curieuse et peut-être unique en zoologie. Elle a été signalée à Nagpur (Hindoustan), Ceylon, Queensland (Australie), Célèbes, Afrique orientale et Sansibar; seulement le premier lieu se trouve bien au nord de l'équateur, mais encore dans la zone tropicale, comme toutes les autres localités. L'explication de cette extension sur les deux mondes est tout ce qu'il a de plus difficile, puisque entre les localisations il n'y a pas seulement d'énormes distances sur terre (que l'on pourrait expliquer par un défaut d'observations), mais des espaces tres étendus, occupés par la mer. L'intervention de l'homme ne saurait expliquer ces faits et le transport par les oiseaux aquatiques ne pourrait être qu'un fait tout-a-fait excepcionnel pour les grands trajets océaniques. Le recours aux terres hypothétiques, qui formaient des ponts intercontinentaux dans des périodes géologiques extrêmement reculées, recontre des objections évidentes. En tous les cas on ne peut qu'admirer la constance avec laquelle le type de l'espèce s'est maintenu durant d'innombrales générations et a travers de telles distances quand les autres phyllopodes ont formé non seulement des variétés, mais même un grand nombre de genre et de familles.

On the number of limit cycles bifurcating from a non-global degenerated center

Vegeu el resum a l'inici del document del fitxer adjunt

Creating and using a non-dedicated HPC cluster with ParallelKnoppix

This note describes ParallelKnoppix, a bootable CD that allows econometricians with average knowledge of computers to create and begin using a high performance computing cluster for parallel computing in very little time. The computers used may be heterogeneous machines, and clusters of up to 200 nodes are supported. When the cluster is shut down, all machines are in their original state, so their temporary use in the cluster does not interfere with their normal uses. An example shows how a Monte Carlo study of a bootstrap test procedure may be done in parallel. Using a cluster of 20 nodes, the example runs approximately 20 times faster than it does on a single computer.

ParallelKnoppix - Rapid deployment of a linux cluster for MPI parallel processing using non-dedicated computers

This note describes ParallelKnoppix, a bootable CD that allows creation of a Linux cluster in very little time. An experienced user can create a cluster ready to execute MPI programs in less than 10 minutes. The computers used may be heterogeneous machines, of the IA-32 architecture. When the cluster is shut down, all machines except one are in their original state, and the last can be returned to its original state by deleting a directory. The system thus provides a means of using non-dedicated computers to create a cluster. An example session is documented.