Somatic embryogenesis and plant regeneration in Piper aduncum L

In Vitro Cellular & Developmental Biology - Plant - An efficient protocol is reported for in vitro plant regeneration through somatic embryogenesis in Piper aduncum, a Brazilian Amazon species...     

Length–weight relationships of 15 fish species in wetland areas of coastal southern Brazil

Herein are the length–weight relationships of 15 fish species from wetland areas of the coastal region in southern Brazil. In 2010, fishes were sampled seasonally in four wetlands utilizing beach seine nets.     

Specific phosphorylation of Torpedo 43K rapsyn by endogenous kinase(s) with thiamine triphosphate as the phosphate donor.

43K rapsyn is a peripheral protein specifically associated with the nicotinic acetylcholine receptor (nAChR) present in the postsynaptic membrane of the neuromuscular junction and of the electrocyte, and is essential for its clustering. Here, we demonstrate a novel specific phosphorylation of 43K rapsyn by endogenous protein kinase(s) present in Torpedo electrocyte nAChR-rich membranes and identify thiamine triphosphate (TTP) as the phosphate donor. In the presence of Mg(2+) and [gamma-(32)P]-TTP, 43K rapsyn is specifically phosphorylated with a (32)P-half-maximal incorporation at approximately 5-25 microM TTP. The presence of TTP in the cytosol and of 43K rapsyn at the cytoplasmic face of the postsynaptic membrane, together with TTP-dependent phosphorylation of 43K rapsyn without added exokinases, suggests that TTP-dependent-43K-rapsyn phosphorylation may occur in vivo. In addition, phosphoamino acid and chemical stability analysis suggests that the residues phosphorylated are predominantly histidines. Inhibition of phosphorylation by Zn(2+) suggests a possible control of 43K rapsyn phosphorylation state by its zinc finger domain. Endogenous kinase(s) present in rodent brain membranes can also use [gamma-(32)P]-TTP as a phosphodonor. The use of a phosphodonor (TTP) belonging to the thiamine family but not to the classical (ATP, GTP) purine triphosphate family represents a novel phosphorylation pathway possibly important for synaptic proteins.     

Avian cholera,post‐hatching survival and selection on hatch characteristics in a long‐lived bird,the common eider Somateria mollisima

Infectious diseases can have dramatic impacts on animal population dynamics, but how they influence vital rates remains understudied. We took advantage of the appearance of an avian cholera epizootic in an arctic colony of common eiders Somateria mollissima to study variation in juvenile survival and selection on hatch characteristics in relation to this highly infectious disease. Avian cholera is one of the most important infectious diseases affecting wild birds and is thought to primarily affect adult survival. Here, we show that avian cholera was associated with a 90% decline in duckling survival, leading to almost zero recruitment. Before the cholera outbreak, there was significant stabilizing selection on hatching date and significant positive directional selection on hatching mass. During cholera outbreaks, selection on hatch characteristics was no longer significant. These results were based on a low sample of surviving ducklings in cholera years, but suggested that date and mass at hatching did no longer affect duckling survival in the presence of cholera. These effects of avian cholera on post‐hatching survival were likely not only the consequence of the disease per se, but also a consequence of an increase in predation rates that followed the emergence of avian cholera. Our results emphasize the dramatic direct and indirect impacts that infectious disease can have on vital rates, and thus population dynamics.     

Selection of nest sites by wood mice Apodemus sylvaticus in a Mediterranean agro-forest landscape

One of the most important structures for an individual’s survival is a refuge, especially for species subject to significant predatory pressure or living in environments affected by severe climatic conditions. We studied how wood mice (Apodemus sylvaticus), inhabiting a Mediterranean environment, use nests and the factors that could be determining this use. Radio-tracking of 16 mice allowed us to detect 24 diurnal nests, which were used with a high fidelity rate (1.75 nests/animal). Nest sites that had been identified using radio-tracking were matched with 24 randomly selected non-nest sites (located within an area defined by the sum of all individual home ranges), and all sites were characterized according to their macro- and micro-habitat parameters. Using a generalized linear model, we tested three hypotheses: (1) a nest’s use is influenced by its proximity to food patches; (2) the degree of sheltering provided by each site influences its use; and (3) nest use is constrained by a combination of food- and shelter-related features. Females had higher nest fidelity than males, and the degree of sheltering provided by each site had a positive significant influence on its use. Nests offering higher protection (e.g., under thick vegetation), good drainage (e.g., sleep slopes), and lower human and predatory disturbance (far from orchards) were most often used. The proximity to food patches seemed to negatively influence nest use. Results indicate the need to preserve patches of natural dense vegetation near riparian habitats, which is in agreement with the focus of mammalian protection plans in Mediterranean agricultural landscapes. These patches are important areas for Apodemus sylvaticus, an acorn disperser species, which is preyed on by raptors and mammalian carnivores.     

Social Network Analysis and Mining to Monitor and Identify Problems with Large-Scale Information and Communication Technology Interventions

The published literature reveals several arguments concerning the strategic importance of information and communication technology (ICT) interventions for developing countries where the digital divide is a challenge. Large-scale ICT interventions can be an option for countries whose regions, both urban and rural, present a high number of digitally excluded people. Our goal was to monitor and identify problems in interventions aimed at certification for a large number of participants in different geographical regions. Our case study is the training at the Telecentros.BR, a program created in Brazil to install telecenters and certify individuals to use ICT resources. We propose an approach that applies social network analysis and mining techniques to data collected from Telecentros.BR dataset and from the socioeconomics and telecommunications infrastructure indicators of the participants’ municipalities. We found that (i) the analysis of interactions in different time periods reflects the objectives of each phase of training, highlighting the increased density in the phase in which participants develop and disseminate their projects; (ii) analysis according to the roles of participants (i.e., tutors or community members) reveals that the interactions were influenced by the center (or region) to which the participant belongs (that is, a community contained mainly members of the same region and always with the presence of tutors, contradicting expectations of the training project, which aimed for intense collaboration of the participants, regardless of the geographic region); (iii) the social network of participants influences the success of the training: that is, given evidence that the degree of the community member is in the highest range, the probability of this individual concluding the training is 0.689; (iv) the North region presented the lowest probability of participant certification, whereas the Northeast, which served municipalities with similar characteristics, presented high probability of certification, associated with the highest degree in social networking platform.