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1.
PeerJ ; 6: e5957, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30564513

RESUMO

BACKGROUND: The Southern Right Whale (Eubalaena australis) population of the South-western Atlantic Ocean is recovering. In the breeding ground of Peninsula Valdés, as a consequence of the population growth, expansion to new areas by some types of groups and a change in the habitat use patterns at the coastal area were recorded. METHODS: We analysed information gathered from aerial surveys conducted along the coast of Peninsula Valdés in 15 years of effective sampling in a 19-year span. These surveys were divided into four periods (1999-2000; 2004-2007; 2008-2012 and 2013-2016) and estimated the density of whales in a 620 km of coast divided into segments of five km. RESULTS: The density of the whales increased to near three whales per km2 (averaged over each period) in the high-density areas. When this mean number was reached, the significant changes in density in the adjacent areas were detected in the following period. These changes were a decrease in density in the high-density areas and an increase of density in the low-density areas. DISCUSSION: We propose that a threshold in density elicits a response in habitat use, with the Mother-calf pairs remaining in the area, while the other groups are displaced to new areas.

2.
PLoS One ; 13(12): e0207524, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30566480

RESUMO

Since the 1980s, the distribution range of the southern right whale (Eubalaena australis) in Argentina was mostly located in the winter calving grounds around Península Valdés. After the international moratorium that forbade the commercial hunting, southern right whales have shown signs of recovery during the last few decades. Nowadays, it is thought that the species is experiencing a density-dependent process while expanding its distribution range in Patagonia. From 2007 to 2016, data on right whale distribution, group composition and relative abundance were collected in Golfo San Matías, Patagonia through aerial surveys. Generalized linear models with a negative binomial error distribution were used to determine the population trend of right whales in this area. In addition, the group composition and the relative abundance of right whales among the northern Patagonian gulfs were compared. Finally, a literature review was conducted to assess the historical presence of right whales in Golfo San Matías, revealing the presence of right whales in Golfo San Matías during and after the commercial exploitation. During aerial surveys (2007-2016), right whales were observed from August to October in the area, with a peak in late August-early September. Our results suggested a geographic distribution change with a regular use of the northwest coast of the gulf in recent years and a positive trend in the population growth rate inside Golfo San Matías. This area was dominated by unaccompanied whales (solitary individuals and breeding groups) as opposed to Península Valdés where the dominant group type was the mother calf pairs. Therefore, Golfo San Matías appears to be important for socializing and mating but not as a nursery ground. In addition, the density of whales was four times greater in the gulfs of Península Valdés. Our findings contribute to a better understanding of the recovery of this species in Patagonia, Argentina and should be considered for the management measures for right whales in this region.


Assuntos
Monitoramento Ambiental , Baleias , Animais , Argentina , Dinâmica Populacional , Estações do Ano
3.
J Neurol Sci ; 224(1-2): 69-76, 2004 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-15450773

RESUMO

Multiple sclerosis has a tendency to remit during pregnancy, followed by an increase in the risk for disease relapses in the postpartum period. In this communication, preliminary data are presented to indicate that activated peripheral blood mononuclear cells (PBMC) from the postpartum period secrete elevated levels of gamma-interferon (IFN-gamma) relative to those collected during the third trimester. In addition, myelin antigen-specific T cell lines established from the third trimester of pregnancy secrete elevated levels of interleukin-10. The data suggest that the study of the mechanisms underlying natural fluctuations in disease activity during pregnancy and the postpartum period holds promise for a better understanding of factors capable of initiating and regulating remission and exacerbation in MS.


Assuntos
Citocinas/metabolismo , Esclerose Múltipla/metabolismo , Período Pós-Parto/metabolismo , Gravidez/metabolismo , Adulto , Anticorpos/farmacologia , Complexo CD3/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Bainha de Mielina/metabolismo , Glicoproteína Associada a Mielina/farmacologia , Terceiro Trimestre da Gravidez/metabolismo
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