Platinum Blue Staining Of Cells Grown In Electrospun Scaffolds.

Fibroblast cells grown in electrospun polymer scaffolds were stained with platinum blue, a heavy metal stain, and imaged using scanning electron microscopy. Good contrast on the cells was achieved compared with samples that were gold sputter coated. The cell morphology could be clearly observed, and the cells could be distinguished from the scaffold fibers. Here we optimized the required concentration of platinum blue for imaging cells grown in scaffolds and show that a higher concentration causes platinum aggregation. Overall, platinum blue is a useful stain for imaging cells because of its enhanced contrast using scanning electron microscopy (SEM). In the future it would be useful to investigate cell growth and morphology using three-dimensional imaging methods.

Behavioral Changes Caused By Austrodiplostomum Spp. In Hoplias Malabaricus From The São Francisco River, Brazil.

Traira (Hoplias malabaricus) is a neotropical fish that is widely distributed in freshwater environments in South America. In the present study, we documented the occurrence of metacercariae of Austrodiplostomum spp. (Diplostomidae) in the eyes and cranial cavity of H. malabaricus and described parasite-induced behavioral changes in the host. The fish were collected from the upper São Francisco River, in the Serra da Canastra mountain range, Minas Gerais, transported alive to the laboratory, observed for 2 weeks, and subsequently examined for parasites. Of the 35 fish examined, 28 (80 %) had free metacercariae in the vitreous humor (mean intensity=95.4; mean abundance=76.3), and 24 (68.57 %) had free metacercariae in the cranial cavity, mainly concentrated below the floor of the brain, at the height of the ophthalmic lobe (mean intensity=12.91; mean abundance=8.85). Specimens of H. malabaricus with a high intensity of infection in the brain displayed changes in swimming behavior.

The River And The Sea: Fieldwork In Human Ecology And Ethnobiology.

This article is a commentary on the experiences that motivated my decision to become a human ecologist and ethnobiologist. These experiences include the pleasure of studying and of having the sense of being within nature, as well as the curiosity towards understanding the world and minds of local people. In particular, such understanding could be driven by addressing the challenging questions that originate in the interactions of such individuals with their natural surroundings. I have been particularly interested in the sea and the riverine forests that are inhabited by coastal or riverine small-scale fishers. Sharing the distinctive world of these fishers enjoyably incited my curiosity and challenged me to understand why fishers and their families 'do as they do' for their livelihoods including their beliefs. This challenge involved understanding the rationality (or the arguments or views) that underlies the decisions these individuals make in their interaction with nature. This curiosity was fundamental to my career choice, as were a number of reading interests. These reading interests included political economy and philosophy; evolution and sociobiology; evolutionary, human, and cultural ecology; cultural transmission; fisheries; local knowledge; ecological economics; and, naturally, ethnobiology.

Composição florística de uma floresta ripária na Reserva Estadual de Porto Ferreira, SP

The point-centred quarter method (63 points) was applied in Porto Ferreira State Reserve (21º49'S and 47º25'W) in an area (1.08ha) on the right margin of Moji Guaçu river, including two woody individuals per quarter - one with DBH < 10cm and at least 130cm high, the other with DBH > 10cm. The results obtained were compared with those published by other authors for a riparian forest (Mata da Figueira) at Moji Guaçu Ecological Station (about 100 km upstream on the same river). At Porto Ferreira 107 species were found, of which 80 were exclusive, compared with the Mata da Figueira where of the 59 species listed, 31 were exclusive. The two area shared 27 common species, thus accounting for a low Sørensen similarity of 48.6%. The great environmental heterogeneity of the floodplains, as well as the degree of anthropic disturbance, could account for this floristic variation. The greatest numbers of species were shown by Leguminosae (20), Myrtaceae (17), Rutaceae (9), Euphorbiaceae (7), and Lauraceae, Meliaceae, Moraceae and Rubiaceae (6 species each). There appears to be little difference at the family level among the periodically flooded and non-flooded forests of the State of São Paulo, but the species show different degreees of preference for habitat. The floristic composition of the two areas presented a mixture of typical species with others of non-flooded forests. The latter would occur on the floodplain probably by a) adaptation of the root system to relatively short flooding periods; b) shorter periods of flooding on the higher points of the microrelief of the floodplain, and c) greater aeration due to running water.

Evaluation of the cytotoxic and genotoxic potential of water from the River Paraíba do Sul, in Brazil, with the Allium cepa L. test

This work investigated the cytotoxic and genotoxic potential of water from the River Paraíba do Sul (Brazil) using Allium cepa roots. An anatomo-morphological parameter (root length), mitotic indices, and frequency of micronuclei were analysed. Eight bulbs were chosen at random for treatment for 24 to 120 hours with the River water collected in the years of 2005 and 2006 from sites in the cities of Tremembé and Aparecida (São Paulo state, Brazil). Daily measurements of the length of the roots grown from each bulb were carried out throughout the experiment. Mitotic index (MI) and frequency of micronuclei (MN) were determined for 2000 cells per root, using 3-5 root tips from other bulbs (7-10). Only in the roots treated with samples of the River water collected in 2005 in Tremembé city was there a decrease in the root length growth compared to the respective control. However, a reduction in MI values was verified for both sites analysed for that year. Considering the data involving root length growth and especially MI values, a cytotoxic potential is suggested for the water of the River Paraíba do Sul at Tremembé and Aparecida, in the year of 2005. On the other hand, since in this year the MN frequency was not affected with the river water treatments, genotoxicity is not assumed for the river water sampled at the aforementioned places.