Source water partitioning as a means of characterizing hydrologic function in mangroves

Mangrove ecosystems rely on seawater, rain-derived flow, and groundwater for hydrologic sustenance, flushing, and inflow of nutrients and sediments. The relative contribution of these source waters and their variability through time and space can provide key information concerning the hydrologic function of ecosystems. We used hydrologic tracers to partition source waters and trace their movements in the Enipoas stream, a river-dominated mangrove ecosystem on the island of Pohnpei, Federated States of Micronesia (FSM) and in the Yela watershed, an interior mangrove ecosystem on the island of Kosrae, FSM. The Enipoas site was characterized as a salt wedge estuary whose source water contributions alternated between predominantly seawater and rain-derived flow, depending on the tide. The source waters in the interior Yela site were also predominantly seawater and rain-derived flow, however the relative contribution of each was much more stable. The mean groundwatercontribution was 5% (SD 5 5.5) for the Enipoas site and 20% (SD 5 11.0) for the Yela site. Although a small contributor to flow, groundwater was a steady source of freshwater for both systems. Hydrologic linkages between mangroves and adjacent ecosystems were demonstrated by the temporal and spatial distribution of source waters.The 0.8 km Enipoas estuary, with its highly dynamic bi-directional flows, transported source waters along a hydrologic continuum comprised of coral reef, mangroves, and palm forest. In the interior mangroves of the Yela watershed, the presence of rain-derived flow and groundwater demonstrated a hydraulic connection between the mangroves and an upstream freshwater swamp. Interior mangroves with such linkages avoid stresses such as desiccation and heightened salinity, and thus are more productive than those with little or no freshwater flows.     

Cross-priming of cytotoxic T cells dictates antigen requisites for modified vaccinia virus Ankara vector vaccines

Recombinant vaccines based on modified vaccinia virus Ankara (MVA) have an excellent record concerning safety and immunogenicity and are currently being evaluated in numerous clinical studies for immunotherapy of infectious diseases and cancer. However, knowledge about the biological properties of target antigens to efficiently induce MVA vaccine-mediated immunity in vivo is sparse. Here, we examined distinct antigen presentation pathways and different antigen formulations contained in MVA vaccines for their capability to induce cytotoxic CD8(+) T-cell (CTL) responses. Strikingly, we found that CTL responses against MVA-produced antigens were dominated by cross-priming in vivo, despite the ability of the virus to efficiently infect professional antigen-presenting cells such as dendritic cells. Moreover, stable mature protein was preferred to preprocessed antigen as the substrate for cross-priming. Our data are essential for improved MVA vaccine design, as they demonstrate the need for optimal adjustment of the target antigen properties to the intrinsic requirements of the delivering vector system.     

Unbiased descriptor and parameter selection confirms the potential of proteochemometric modelling

Background  

Proteochemometrics is a new methodology that allows prediction of protein function directly from real interaction measurement data without the need of 3D structure information. Several reported proteochemometric models of ligand-receptor interactions have already yielded significant insights into various forms of bio-molecular interactions. The proteochemometric models are multivariate regression models that predict binding affinity for a particular combination of features of the ligand and protein. Although proteochemometric models have already offered interesting results in various studies, no detailed statistical evaluation of their average predictive power has been performed. In particular, variable subset selection performed to date has always relied on using all available examples, a situation also encountered in microarray gene expression data analysis.     

Impaired transporter associated with antigen processing (TAP) function attributable to a single amino acid alteration in the peptide TAP subunit TAP1

The heterodimeric peptide transporter TAP belongs to the ABC transporter family. Sequence comparisons with the P-glycoprotein and cystic fibrosis transmembrane conductance regulator and the functional properties of selective amino acids in these ABC transporters postulated that the glutamic acid at position 263 and the phenylalanine at position 265 of the TAP1 subunit could affect peptide transporter function. To define the role of both amino acids, TAP1 mutants containing a deletion or a substitution to alanine at position 263 or 265 were generated and stably expressed in murine and human TAP1(-/-) cells. The different TAP1 mutants were characterized in terms of expression and function of TAP, MHC class I surface expression, immune recognition, and species-specific differences. The phenotype of murine and human cells expressing human TAP1 mutants with a deletion or substitution of Glu(263) was comparable to that of TAP1(-/-) cells. In contrast, murine and human TAP1 mutant cells containing a deletion or mutation of Phe(265) of the TAP1 subunit exhibit wild-type TAP function. This was associated with high levels of MHC class I surface expression and recognition by specific CTL, which was comparable to that of wild-type TAP1-transfected control cells. Thus, biochemical and functional evidence is presented that the Glu(263) of the TAP1 protein, but not the Phe(265), is critical for proper TAP function.     

Identification of an Unclassified Paramyxovirus in Coleura afra: A Potential Case of Host Specificity

Bats are known to harbor multiple paramyxoviruses. Despite the creation of two new genera, Aquaparamyxovirus and Ferlavirus, to accommodate this increasing diversity, several recently isolated or characterized viruses remain unclassified beyond the subfamily level. In the present study, among 985 bats belonging to 6 species sampled in the Belinga caves of Gabon, RNA of an unclassified paramyxovirus (Belinga bat virus, BelPV) was discovered in 14 African sheath-tailed bats (Coleura afra), one of which exhibited several hemorrhagic lesions at necropsy, and viral sequence was obtained in two animals. Phylogenetically, BelPV is related to J virus and Beilong virus (BeiPV), two other unclassified paramyxoviruses isolated from rodents. In the diseased BelPV-infected C. afra individual, high viral load was detected in the heart, and the lesions were consistent with those reported in wild rodents and mice experimentally infected by J virus. BelPV was not detected in other tested bat species sharing the same roosting sites and living in very close proximity with C. afra in the two caves sampled, suggesting that this virus may be host-specific for C. afra. The mode of transmission of this paramyxovirus in bat populations remains to be discovered.     

Transgenic tobacco plants expressing Tarin 1 inhibit the growth of Pseudomonas syringae pv. tomato and the development of Spodoptera frugiperda

The protein Tarin 1, from Colocasia esculenta, was expressed in Nicotiana tabacum. Bioassays were done on plants expressing Tarin 1 at different levels using Spodoptera frugiperda larvae, various bacteria and fungi and the root‐knot nematode Meloidogyne javanica. It was found that S. frugiperda larvae fed on transformed plants had retarded and lower pupation, lower accumulated biomass and higher mortality rate than larvae fed on control plants. Also, Tarin 1 was found to inhibit the growth in vitro of Pseudomonas syringae pv. tomato. For Meloidogyne javanica, both relative replication and root damage were greater in control plants than in transformed plants, but the results were not statistically significant. This work illustrates the effects of plants expressing Tarin 1, on the growth and development of insects and bacteria, and shows its potential for pest management.     

Henipavirus RNA in African Bats

Background

Henipaviruses (Hendra and Nipah virus) are highly pathogenic members of the family Paramyxoviridae. Fruit-eating bats of the Pteropus genus have been suggested as their natural reservoir. Human Henipavirus infections have been reported in a region extending from Australia via Malaysia into Bangladesh, compatible with the geographic range of Pteropus. These bats do not occur in continental Africa, but a whole range of other fruit bats is encountered. One of the most abundant is Eidolon helvum, the African Straw-coloured fruit bat.

Methodology/Principal Findings

Feces from E. helvum roosting in an urban setting in Kumasi/Ghana were tested for Henipavirus RNA. Sequences of three novel viruses in phylogenetic relationship to known Henipaviruses were detected. Virus RNA concentrations in feces were low.

Conclusions/Significance

The finding of novel putative Henipaviruses outside Australia and Asia contributes a significant extension of the region of potential endemicity of one of the most pathogenic virus genera known in humans.     

Summer distribution of Red-legged Partridges Alectoris rufa in relation to water availability on Mediterranean farmland

The suggestion that the summer distribution of Red-legged Partridges Alectoris rufa in the Mediterranean region is determined by the availability of surface water was examined on the agricultural farm, Alto Alentejo, southern Portugal. Partridge coveys were surveyed between 15 July and 15 August in 1993 and 1994. Using a vector-based Geographic Information System, we assessed, for each covey location and for the locations of a double number of random points, the distance to the nearest water point, distance to field boundaries, distance to water lines and land use classes. Univariate comparisons were made between the two groups of locations, and three multivariate logistic models were fitted through forward stepwise selection to the 1993, 1994 and pooled data sets to estimate the probability of sighting partridge coveys in the study area. Distance to water was significantly lower for partridge locations than for random points in both years and was the only variable selected for all logistic models. Apart from water availability, Red-legged Partridge locations were also affected by land use and distance to field boundaries.