A new species of Potamotrygonocestus Brooks & Thorson, 1976 (Eucestoda : Tetraphyllidea) from Plesiotrygon iwamae Rosa, Castello & Thorson (Mylliobatoidea : Potamotrygonidae) and a redescription of Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003

Potamotrygonocestus Brooks & Thorson, 1976 is currently represented by six recognised species of tetraphyllidean cestodes inhabiting Neotropical freshwater stingrays. Potamotrygonid stingrays examined to date have included only a single specimen of Plesiotrygon iwamae. Only one species of tetraphyllidean, Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003, has been described from this host, and this description was based on limited material. New efforts to document the diversity in this host species resulted in the collection of eight additional specimens of P. iwamae, one of these from the upper Rio Solimoes, at Sao Paulo de Olivenca Amazonas during September, 2003, and seven from the Baia do Marajo, Para, during November, 2003. The specimen from the upper Solimoees was found to be infected with P. chaoi. Voucher material from this stingray was used for the redescription of this cestode, which is characterized by strobila 8.78-22.83 mm long and a great number of proglottides, 58-93; the new material provided strobilar length and proglottis counts for complete worms. Potamotrygonocestus marajoara n. sp. is the second species of this genus reported from Plesiotrygon iwamae, although it appears to be restricted to the lower Amazon. This new species resembles P. chaoi in possessing filitriches and blade-like spinitriches on the scolex, cephalic peduncle and cirrus, but differs from other species of the genus in the number of testes, which is 44 on average per proglottis, and by having apical sucker measuring 95-175 mu m in length. Additional data on the distribution and morphology of the microtriches and a detailed description of the female reproductive system are also provided in this study.

Comparative Internal Structure of Dorsal Lips and Radiolar Appendages in Sabellidae (Polychaeta) and Phylogenetic Implications

Fan worms (Sabellidae) possess paired modified prostomial structures at the base of the radiolar crown, dorso-lateral to the mouth, called dorsal lips. The dorsal lips are involved in the sorting of particles collected by the radiolar crown. The range of variation in the morphology of dorsal lips is extensive, and probably this is not only due to adaptations to different environments and feeding preferences but also due to phylogenetic constraints. In this study, we describe and compare the morphology of dorsal lips in a range of sabellid taxa based on histological cross-sections of these structures, and compare our data and terminology with those of previous studies. Dorsal lips are maintained erect in most taxa by a modified radiole fused to them known as dorsal radiolar appendage. We suggest that dorsal radiolar appendages with an internal supporting axis (cellular or acellular) and probably also the ventral lips are synapomorphies of the family. J. Morphol. 272: 302-319, 2011. (C) 2010 Wiley-Liss, Inc.

PAS-1, a protein from Ascaris suum, modulates allergic inflammation via IL-10 and IFN-gamma, but not IL-12

Helminths and their products have a profound immunomodulatory effect upon the inductive and effector phases of inflammatory responses, including allergy. We have demonstrated that PAS-1, a protein isolated from Ascaris strum worms, has an inhibitory effect on lung allergic inflammation due to its ability to down-regulate eosinophilic inflammation, Th2 cytokine release and IgE antibody production. Here, we investigated the role of IL-12, IFN-gamma and IL-10 in the PAS-1-induced inhibitory mechanism using a murine model of asthma. Wild type C57BL/6, IL-12(-/-), IFN-gamma(-/-) and IL-10(-/-) mice were immunized with PAS-1 and/or OVA and challenged with the same antigens intranasally. The suppressive effect of PAS-I was demonstrated on the cellular influx into airways, with reduction of eosinophil number and eosinophil peroxidase activity in OVA + PAS-1-immunized wild type mice. This effect well correlated with a significant reduction in the levels of IL-4, IL-5, IL-13 and eotaxin in BAL fluid. Levels of IgE and IgG1 antibodies were also impaired in serum from these mice. The inhibitory activity of PAS-I was also observed in IL-12(-/-) mice, but not in IFN-gamma(-/-) and IL-10(-/-) animals. These data show that IFN-gamma and IL-10, but not IL-12, play an important role in the PAS-1 modulatory effect. (C) 2008 Elsevier Ltd. All rights reserved.

Vitellin-binding proteins in the nematode Oscheius tipulae (Nematoda, Rhabditida)

We describe the first application of a non-radioactive ligand-blotting technique to the characterization of proteins interacting with nematode vitellins. Chromatographically purified vitellins from the free-living nematode Oscheius tipulae were labeled with fluorescein in vitro. Ligand-blotting assays with horseradish peroxidase-conjugated anti-fluorescein antibodies showed that labeled vitellins reacted specifically with a polypeptide of approximately 100 kDa, which we named P100. This polypeptide is a specific worm`s vitellin-binding protein that is present only in adult worms. Blots containing purified O. tipulae vitellin preparations showed no detectable signal in the 100 kDa region, ruling out any possibility of yolk polypeptides self-assembling under the conditions used in our assay. Experiments done in the presence of alpha-methyl mannoside ruled out the possibility of vitellins binding to P100 through mannose residues. Triton X-114 fractionation of whole worm extracts showed that P100 is either a membrane protein or has highly hydrophobic regions. (C) 2008 Elsevier Inc. All rights reserved.

The Xanthomonas citri effector protein PthA interacts with citrus proteins involved in nuclear transport, protein folding and ubiquitination associated with DNA repair

P>Xanthomonas axonopodis pv. citri utilizes the type III effector protein PthA to modulate host transcription to promote citrus canker. PthA proteins belong to the AvrBs3/PthA family and carry a domain comprising tandem repeats of 34 amino acids that mediates protein-protein and protein-DNA interactions. We show here that variants of PthAs from a single bacterial strain localize to the nucleus of plant cells and form homo- and heterodimers through the association of their repeat regions. We hypothesize that the PthA variants might also interact with distinct host targets. Here, in addition to the interaction with alpha-importin, known to mediate the nuclear import of AvrBs3, we describe new interactions of PthAs with citrus proteins involved in protein folding and K63-linked ubiquitination. PthAs 2 and 3 preferentially interact with a citrus cyclophilin (Cyp) and with TDX, a tetratricopeptide domain-containing thioredoxin. In addition, PthAs 2 and 3, but not 1 and 4, interact with the ubiquitin-conjugating enzyme complex formed by Ubc13 and ubiquitin-conjugating enzyme variant (Uev), required for K63-linked ubiquitination and DNA repair. We show that Cyp, TDX and Uev interact with each other, and that Cyp and Uev localize to the nucleus of plant cells. Furthermore, the citrus Ubc13 and Uev proteins complement the DNA repair phenotype of the yeast Delta ubc13 and Delta mms2/uev1a mutants, strongly indicating that they are also involved in K63-linked ubiquitination and DNA repair. Notably, PthA 2 affects the growth of yeast cells in the presence of a DNA damage agent, suggesting that it inhibits K63-linked ubiquitination required for DNA repair.

A new member of the ribbon-helix-helix transcription factor superfamily from the plant pathogen Xanthomonas axonopodis pv. citri

XACb0070 is an uncharacterized protein coded by the two large plasmids isolated from Xanthomonas axonopodis pv. cirri, the agent of citrus canker and responsible for important economical losses in citrus world production. XACb0070 presents sequence homology only with other hypothetical proteins belonging to plant pathogens, none of which have their structure determined. The NMR-derived solution structure reveals this protein is a homodimer in which each monomer presents two domains with different structural and dynamic properties: a folded N-terminal domain with beta alpha alpha topology which mediates dimerization and a long disordered C-terminal tail. The folded domain shows high structural similarity to the ribbon-helix-helix transcriptional repressors, a family of DNA-binding proteins of conserved 3D fold but low sequence homology: indeed XACb0070 binds DNA. Primary sequence and fold comparison of XACb0070 with other proteins of the ribbon-helix-helix family together with examination of the genes in the vicinity of xacb0070 suggest the protein might be the component of a toxin-antitoxin system. (C) 2010 Elsevier Inc. All rights reserved.

Schistosoma mansoni: In vitro schistosomicidal activity of piplartine

Schistosomiasis is one of the world`s greatly neglected tropical diseases, and its control is largely dependent on a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentration of 15.8 mu M reduced the motor activity of worms and caused their death within 24 h in a RPMI 1640 medium. Similarly, the highest sub-lethal concentration of piplartine (6.3 mu M) caused a 75% reduction in egg production in spite of coupling. Additionally, piplartine induced morphological changes on the tegument, and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destruction and damage in the tubercles. This damage was dose-dependent in the range of 15.8-630.2 mu M. At doses higher than 157.6 mu M, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported for piplartine. Published by Elsevier Inc.

Eri silk fibre attributes and sliver preparation

Eri silk produced by Philosamia cynthia ricini silkworm is a fibre not well-known to the silk industry, in spite of the fact that Eri silk is finer, softer, and has better mechanical and thermal properties than most animal fibres. Eri silk has a high commercial potential, as the host plants of Eri silk worms are widespread in diverse geographical locations, and the worms also have a higher degree of disease resistance than most other silk worms. Mills are often not aware of the properties of Eri for designing appropriate end products. Thus, Eri silk yarn is traditionally produced by hand spinning, and Eri silk usually ends up as material for handwoven shawls. The potential for bulk fibre processing and the development of soft luxurious novel Eri silk products is yet to be discovered. To better understand the material and its processing behaviour, Eri silk was characterised and cocoons were processed into tops through degumming, opening, and cutting filaments into different lengths, followed by a worsted spun silk processing route. Fibre properties such as fineness, crimp, strength and length at different processing stages up to combed tops were measured. The results indicate that staple Eri silk can be processed via the worsted topmaking route, using a cut length of 200 mm or 150 mm for filament sheets prepared from degummed cocoons.

Annetocin and TCTP expressions in the earthworm Eisenia fetida exposed to PAHs in artificial soil

The toxicity of sublethal polycyclic aromatic hydrocarbons (PAHs) levels in soils was assessed by testing their impact on expression of annetocin, a reproduction regulating gene, and translationally controlled tumor protein (TCTP), a tumorigenic response gene, in the earthworm Eisenia fetida cultured in artificial soil spiked with, phenanthrene (Phe), pyrene (Pyr), fluoranthene (Flu), or benzo(a)pyrene (Bap). Annetocin and TCTP were both up-regulated by 0.1 and 1.0 mg kg−1 benzo(a)pyrene and TCTP was down-regulated by 10.0 mg kg−1 phenanthrene. Weight loss and cocoon production of the worms were also analyzed. Only 10.0 mg kg−1 phenanthrene impacted earthworm weight loss significantly and no significant differences on cocoon production were observed. Our study indicated that the potential ecotoxicity of sublethal PAHs in soil should not be neglected and mRNA transcription level in earthworms was a more sensitive indicator of PAHs exposure than traditional indexes using cocoon production as endpoints and/or using the whole-organism as the test materials.

Barriers to cross-fertilization between populations of a widely dispersed Polychaete species are unlikely to have arisen through gametic compatibility arms-races

Although there are theoretical reasons to suspect that gametic incompatibility may develop readily among populations of broadcast spawning marine invertebrates, there have been very few studies documenting geographic patterns of interpopulation incompatibility for any species. To address this we determined how successfully individuals of the intertidal serpulid polychaete, Galeolaria caespitosa, can cross-fertilize within and among populations from across temperate Australia. Fertilization assays revealed asymmetrical differences between very distantly located populations from different coasts, with near-complete incompatibility between eggs from Sydney with sperm from Adelaide, but the reverse cross (Adelaide eggs, Sydney sperm) was reasonably compatible. Although that pattern was congruent with a clear difference in Cytochrome B sequences between worms on the south and east coasts of Australia, we also detected some indication of interpopulation incompatibility within the genetic grouping on east coast, between two populations separated by only 220 km. We then assessed whether commonly proposed gametic compatibility arms-races could account for these patterns. Our results suggest reduced gametic compatibility may reduce a female's maximum fertilization potential, resulting in a cost to this potential mechanism for reducing polyspermy. Consequently, the apparently rapid development of reproductive barriers here seems unlikely to have been driven by arms-races involving sexual conflict over fertilization rate.

Mutual authentication with malware protection for a RFID system

Radio Frequency Identification (RFID) system is a remote identification technology which is taking the place of barcodes to become electronic tags of an object. However, its radio transmission nature is making it vulnerable in terms of security. Recently, research proposed that an RFID tag can contain malicious code which might spread viruses, worms and other exploits to middleware and back-end systems. This paper is proposing a framework which will provide protection from malware and ensure the data privacy of a tag. The framework will use a sanitization technique with a mutual authentication in the reader level. This will ensure that any malicious code in the tag is identified. If the tag is infected by malicious code it will stop execution of the code in the RFIF system. Here shared unique parameters are used for authentication. It will be capable of protecting an RFID system from denial of service (DOS) attack, forward security and rogue reader better than existing protocols. The framework is introducing a layer concept on a smart reader to reduce coupling between different tasks. Using this framework, the RFID system will be protected from malware and also the privacy of the tag will be ensured.

The microcosmic model of worm propagation

Each year, large amounts of money and labor are spent on patching the vulnerabilities in operating systems and various popular software to prevent exploitation by worms. Modeling the propagation process can help us to devise effective strategies against those worms' spreading. This paper presents a microcosmic analysis of worm propagation procedures. Our proposed model is different from traditional methods and examines deep inside the propagation procedure among nodes in the network by concentrating on the propagation probability and time delay described by a complex matrix. Moreover, since the analysis gives a microcosmic insight into a worm's propagation, the proposed model can avoid errors that are usually concealed in the traditional macroscopic analytical models. The objectives of this paper are to address three practical aspects of preventing worm propagation: (i) where do we patch? (ii) how many nodes do we need to patch? (iii) when do we patch? We implement a series of experiments to evaluate the effects of each major component in our microcosmic model. Based on the results drawn from the experiments, for high-risk vulnerabilities, it is critical that networks reduce the number of vulnerable nodes to below 80%. We believe our microcosmic model can benefit the security industry by allowing them to save significant money in the deployment of their security patching schemes.

Discriminating DDoS attack traffic from flash crowd through packet arrival patterns

Current DDoS attacks are carried out by attack tools, worms and botnets using different packet-transmission strategies and various forms of attack packets to beat defense systems. These problems lead to defense systems requiring various detection methods in order to identify attacks. Moreover, DDoS attacks can mix their traffics during flash crowds. By doing this, the complex defense system cannot detect the attack traffic in time. In this paper, we propose a behavior based detection that can discriminate DDoS attack traffic from traffic generated by real users. By using Pearson's correlation coefficient, our comparable detection methods can extract the repeatable features of the packet arrivals. The extensive simulations were tested for the accuracy of detection. We then performed experiments with several datasets and our results affirm that the proposed method can differentiate traffic of an attack source from legitimate traffic with a quick response. We also discuss approaches to improve our proposed methods at the conclusion of this paper.

The probability model of peer-to-peer botnet propagation

Active Peer-to-Peer worms are great threat to the network security since they can propagate in automated ways and flood the Internet within a very short duration. Modeling a propagation process can help us to devise effective strategies against a worm's spread. This paper presents a study on modeling a worm's propagation probability in a P2P overlay network and proposes an optimized patch strategy for defenders. Firstly, we present a probability matrix model to construct the propagation of P2P worms. Our model involves three indispensible aspects for propagation: infected state, vulnerability distribution and patch strategy. Based on a fully connected graph, our comprehensive model is highly suited for real world cases like Code Red II. Finally, by inspecting the propagation procedure, we propose four basic tactics for defense of P2P botnets. The rationale is exposed by our simulated experiments and the results show these tactics are of effective and have considerable worth in being applied in real-world networks.

Effects of social characters in viral propagation seeding strategies in online social networks

Online social networks have not only become a point of aggregation and exchange of information, they have so radically rooted into our everyday behaviors that they have become the target of important network attacks. We have seen an increasing trend in Sybil based activity, such as in personification, fake profiling and attempts to maliciously subvert the community stability in order to illegally create benefits for some individuals, such as online voting, and also from more classic informatics assaults using specifically mutated worms. Not only these attacks, in the latest months, we have seen an increase in spam activities on social networks such as Facebook and RenRen, and most importantly, the first attempts at propagating worms within these communities. What differentiates these attacks from normal network attacks, is that compared to anonymous and stealthy activities, or by commonly untrusted emails, social networks regain the ability to propagate within consentient users, who willingly accept to partake. In this paper, we will demonstrate the effects of influential nodes against non-influential nodes through in simulated scenarios and provide an overview and analysis of the outcomes.