Changes in Plasma Sex Steroids in Females of Two Sympatric Leptodactylus from Subtropical South America

Leptodactylus ocellatus is a well-known neotropical anuran in Argentina and Brazil, typically inhabiting marshes and streams, from sea level to 1000-1200 m in the Pampean mountains. Leptodactylus ocellatus is sympatric with L. chaquensis in Paraguay and on the Parana borders. Previous work (Cei, 1948,1949,1950,1980; Cei et al., 1955) with these two sibling species, L. ocellatus and L. chaquensis, revealed diversity in their reproductive cycles. Leptodactylus ocellatus exhibits less gametogenetic discontinuity and variety of secondary sex characters; the annual ovarian cycle of L. chaquensis, involves a fallwinter period of atresia for the residual mature oocytes from the former cycle, and at the same time a progressive auxocytic activity. The spring-summer period of mating and egg-laying of L. chaquensis is followed by resorption of retained oocytes. Moreover, in both sexes, a striking seasonal rhythm in the development of secondary sex characters has been found, together with dramatic growth of skeletal humeri and significant variation in serum calcium values (Cohen 1962a, b, 1963).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Changes in Plasma Sex Steroids in Females of Two Sympatric Leptodactylus from Subtropical South America

Leptodactylus ocellatus is a well-known neotropical anuran in Argentina and Brazil, typically inhabiting marshes and streams, from sea level to 1000-1200 m in the Pampean mountains. Leptodactylus ocellatus is sympatric with L. chaquensis in Paraguay and on the Parana borders. Previous work (Cei, 1948,1949,1950,1980; Cei et al., 1955) with these two sibling species, L. ocellatus and L. chaquensis, revealed diversity in their reproductive cycles. Leptodactylus ocellatus exhibits less gametogenetic discontinuity and variety of secondary sex characters; the annual ovarian cycle of L. chaquensis, involves a fallwinter period of atresia for the residual mature oocytes from the former cycle, and at the same time a progressive auxocytic activity. The spring-summer period of mating and egg-laying of L. chaquensis is followed by resorption of retained oocytes. Moreover, in both sexes, a striking seasonal rhythm in the development of secondary sex characters has been found, together with dramatic growth of skeletal humeri and significant variation in serum calcium values (Cohen 1962a, b, 1963).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Changes in Plasma Sex Steroids in Females of Two Sympatric Leptodactylus from Subtropical South America

Leptodactylus ocellatus is a well-known neotropical anuran in Argentina and Brazil, typically inhabiting marshes and streams, from sea level to 1000-1200 m in the Pampean mountains. Leptodactylus ocellatus is sympatric with L. chaquensis in Paraguay and on the Parana borders. Previous work (Cei, 1948,1949,1950,1980; Cei et al., 1955) with these two sibling species, L. ocellatus and L. chaquensis, revealed diversity in their reproductive cycles. Leptodactylus ocellatus exhibits less gametogenetic discontinuity and variety of secondary sex characters; the annual ovarian cycle of L. chaquensis, involves a fallwinter period of atresia for the residual mature oocytes from the former cycle, and at the same time a progressive auxocytic activity. The spring-summer period of mating and egg-laying of L. chaquensis is followed by resorption of retained oocytes. Moreover, in both sexes, a striking seasonal rhythm in the development of secondary sex characters has been found, together with dramatic growth of skeletal humeri and significant variation in serum calcium values (Cohen 1962a, b, 1963).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

FedCohesion: Federated Identity Management in the Marche Region

Federated identity management is a set of technologies and processes supporting dynamically distribute identity information. Its adoption in Public Administrations maintains organizations autonomy giving at the same time citizens support to access the services that are distributed across security domains. In this paper, we propose the Marche Region experience for what concern federate identity management focusing on the regional authentication framework, named FedCohesion. It is bases on Security Assertion Markup Language standard and it results from Cohesion re-engineering. It is the old style legacy authentication framework. We first present resulting architecture showing supported identification process and pilot applications. Lessons learned and opportunities have been also presented

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Electronic structure and molecular orientation of a Zn-tetra-phenyl porphyrin multilayer on Si(111)

The electronic properties and the molecular orientation of Zn-tetraphenyl-porphyrin films deposited on Si(111) have been investigated using synchrotron radiation. For the first time we have revealed and assigned the fine structures in the electronic spectra related to the HOMOs and LUMOs states. This is particularly important in order to understand the orbital interactions, the bond formation and the evolution of the electronic properties with oxidation or reduction of the porphyrins in supramolecular donor-acceptor complexes used in photovoltaic devices.Comment: text 11 pages, 4 figures submitted for publicatio