Transcriptome analysis of Euterpe edulis and identification of microsatellite markers.

2016

Secure and energy-efficient data aggregation with malicious aggregator identification in wireless sensor networks

Data aggregation in wireless sensor networks is employed to reduce the communication overhead and prolong the network lifetime. However, an adversary may compromise some sensor nodes, and use them to forge false values as the aggregation result. Previous secure data aggregation schemes have tackled this problem from different angles. The goal of those algorithms is to ensure that the Base Station (BS) does not accept any forged aggregation results. But none of them have tried to detect the nodes that inject into the network bogus aggregation results. Moreover, most of them usually have a communication overhead that is (at best) logarithmic per node. In this paper, we propose a secure and energy-efficient data aggregation scheme that can detect the malicious nodes with a constant per node communication overhead. In our solution, all aggregation results are signed with the private keys of the aggregators so that they cannot be altered by others. Nodes on each link additionally use their pairwise shared key for secure communications. Each node receives the aggregation results from its parent (sent by the parent of its parent) and its siblings (via its parent node), and verifies the aggregation result of the parent node. Theoretical analysis on energy consumption and communication overhead accords with our comparison based simulation study over random data aggregation trees.

Identification and characterization of a novel IL-4 receptor α chain (IL-4Rα) antagonist to inhibit IL-4 signalling

BACKGROUND/AIMS: In recent times, allergy has become a financial, physical and psychological burden to the society as a whole. In allergic cascades, cytokine IL-4 binds to IL-4 receptor (IL-4R), consequently producing allergen-specific IgE antibodies by B cells. In addition, among other functions, IL-4 is also responsible for B and T cell proliferation and differentiation. Hence, characterization of novel antagonists that inhibit IL-4 signalling forms the overall aim of this study. METHODS: Phage display was used to screen a random 12-mer synthetic peptide library with a human IL-4Rα to identify peptide candidates. Once identified, the peptides were commercially synthesized and used for in vitro immunoassays. RESULTS: We have successfully used phage display to identify M13 phage clones that demonstrated specific binding to IL-4Rα. The peptide N1 was synthesized for use in ELISA, demonstrating significant binding to IL-4Rα and inhibiting interaction with cytokine IL-4. Furthermore, the peptide was tested in a transfected HEK-Blue IL-4 reporter cell line model, which produces alkaline phosphatase (AP). QUANTI-Blue, a substrate, breaks down in the presence of AP producing a blue coloration. Using this colorimetric analysis, >50% inhibition of IL-4 signalling was achieved. CONCLUSION: We have successfully identified and characterised a synthetic peptide antagonist against IL-4Rα, which effectively inhibits IL-4 interaction with the IL-4Rα in vitro. Since IL-4 interaction with IL-4Rα is a common pathway for many allergies, a prophylactic treatment can be devised by inhibiting this interaction for future treatment of allergies.

DNA barcoding: an effective tool to overcome morphological identification constraints in the assessment of the ecological quality

DNA barcoding has the potential to overcome taxonomic challenges in biological community assessments. However, fulfilling that potential requires successful amplification of a large and unbiased portion of the community. In this study, we attempted to identify mitochondrial gene cytochrome c oxidase I (COI) barcodes from 1024 benthic invertebrate specimens belonging to 54 taxa from low salinity environments of the Mira estuary and Torgal riverside (SW Portugal). Up to 17 primer pairs and several reaction conditions were attempted among specimens from all taxa, with amplification success defined as a single band of approximately 658 bp visualized on a pre-cast agarose gel, starting near the 5' end of the COI gene and suitable for sequencing. Amplification success was achieved for 99.6% of the 54 taxa, though no single primer was successful for more than 88.9% of the taxa. However, only 68.5% of the specimens within these taxa successfully amplified. Inhibition factors resulting from a non-purified DNA extracted and inexistence of species-specific primers for COI were pointed as the main reasons for an unsuccessful amplification. These results suggest that DNA barcoding can be an effective tool for application in low salinity environments where taxa such as chironomids and oligochaetes are challenging for morphological identification. Nevertheless, its implementation is not simple, as methods are still being standardized and multiple species

Identification and characterization of parasitism genes from the pinewood nematode Bursaphelenchus xylophilus reveals a multilayered detoxification strategy.

The migratory endoparasitic nematode Bursaphelenchus xylophilus, which is the causal agent of pine wilt disease, has phytophagous and mycetophagous phases during its life cycle. This highly unusual feature distinguishes it from other plantparasitic nematodes and requires profound changes in biology between modes. During the phytophagous stage, the nematode migrates within pine trees, feeding on the contents of parenchymal cells. Like other plant pathogens, B. xylophilus secretes effectors from pharyngeal gland cells into the host during infection.We provide the first description of changes in the morphology of these gland cells between juvenile and adult life stages. Using a comparative transcriptomics approach and an effector identification pipeline, we identify numerous novel parasitism genes which may be important for the mediation of interactions of B. xylophilus with its host. In-depth characterization of all parasitism genes using in situ hybridization reveals two major categories of detoxification proteins, those specifically expressed in either the pharyngeal gland cells or the digestive system. These data suggest that B. xylophilus incorporates effectors in a multilayer detoxification strategy in order to protect itself from host defence responses during phytophagy.

Searching for novel targets to control wheat Head Blight Disease-I-Protein identification, 3D modeling and virtual screening.

2016