Electromagnetic interference shielding and radiation absorption in thin polypyrrole films

Results of permittivity measurements, electromagnetic interference shielding effectiveness, and heat generation due to microwave absorption in conducting polymer coated textiles are reported and discussed. The intrinsically conducting polymer, polypyrrole, doped with anthraquinone-2-sulfonic acid (AQSA) or para-toluene-2-sulfonic acid (pTSA) was applied on textile substrates and the resulting materials were investigated in the frequency range 1–18 GHz. The 0.54 mm thick conducting textile/polypyrrole composites absorbed up to 49.5% of the incident 30–35 W microwave radiation. A thermography station was used to monitor the temperature of these composites during the irradiation process, where absorption was confirmed via visible heat losses. Samples with lower conductivity showed larger temperature increases caused by microwave absorption compared to samples with higher conductivity. A sample with an average sheet resistivity of 150 Ω/sq. showed a maximum temperature increase of 5.27 °C, whilst a sample with a lower resistivity (105 Ω/sq.) rose by 3.85 °C.

Suppression of bovine viral diarrhea virus replication by small interfering RNA and short hairpin RNA-mediated RNA interference

Bovine viral diarrhea virus (BVDV) is a ubiquitous viral pathogen that affects cattle herds’ worldwide causing significant economic loss. The current strategies to control BVDV infection include vaccination (modified-live or killed) and control of virus spread by enhanced biosecurity management, however, the disease remains prevalent. With the discovery of the sequence-specific method of gene silencing known as RNA interference (RNAi), a new era in antiviral therapies has begun. Here we report the efficient inhibition of BVDV replication by small interfering (siRNA) and short hairpin RNA (shRNA)-mediated gene silencing. siRNAs were generated to target the 5′ non-translated (NTR) region and the regions encoding the C, NS4B and NS5A proteins of the BVDV genome. The siRNAs were first validated using an EGFP/BVDV reporter system and were then shown to suppress BVDV-induced cytopathic effects and viral titers in cell culture with surprisingly different activities compared to the reporter system. Efficient viral suppression was then achieved by bovine 7SK-expressed BVDV-specific shRNAs. Overall, our results demonstrated the use of siRNA and shRNA-mediated gene silencing to achieve efficient inhibition of the  replication of this virus in cell culture.

Maintaining optimal co-channel interference for power efficient wireless communication

Maintaining QoS (quality of service) guaranteed communication links, and improving the energy consumption; are two aspects that received a significant consideration in the modern wireless sensor network research. This paper formulates a transmission power control problem which satisfies both considerations mentioned above. Moreover, a class of functions for an iterative controller was introduced and analyzed for its convergence. The experimental evaluation of the controller justifies the theoretical assertions as well as the applicability of the control scheme in wireless nodes with minimum measurement capabilities.

Do female and male employees in Iran experience similar work-family interference, job and life satisfaction?

This study aims at examining gender differences in the experience of work–family interference and perceived job–life satisfaction in a group of Iranian employees. The participants in the study consist of 387 Iranian male and female employees from a variety of organizations. The results of t tests and multiple regression analysis using EQS 6.1 support the hypothesis that Iranian male and female employees experience similar interference in their work–family domains although they spend different numbers of hours in the workplace. The findings also show that whereas work-to-family interference has significant and negative effects on job–life satisfaction among male employees, for female employees, working hours and family-to-work interference had even more significant and negative effects on their job–ife satisfaction. Implications are discussed and recommendations made regarding future research and interventions in this area.

Effects of contextual interference on children learning forehand tennis groundstrokes

Previous research on contextual interference theory in controlled laboratory situations consistently illustrated that random practice was superior to blocked practice when learning motor skills. However, when considered in relation to physical education class settings the findings of the contextual interference experiments were not as uniform. Furthermore, the results of the contextual interference research were ambiguous when an open skill was used as the experimental task, with no definite trend evident. Random practice was found more effective for learning (del Rey, 1989) whereas French, Rink and Werner (1990) demonstrated blocked practice to be superior. In the present study, the influence of high and low contextual interference as practice schedules was investigated within an applied sports setting using an open sports skill as the experimental task. Two groups of boys and girls, 8-9 and 10-12 years of age, were taught a forehand tennis groundstroke using both their preferred and non-preferred hands over a ten week coaching and practice period. The findings showed that male subjects were significantly better at the experimental task than female subjects at the pre-test stage only. The result also demonstrated that the 10-12 year old subjects were significantly better than the 8-9 year olds at the task with the exception of the preferred hand at the post and retention test stage. The contextual interference effect was demonstrated in the retention phase on the preferred hand of the 10-12 year old subjects where the random practice group was significantly better than the blocked practice group in an applied sports setting. These findings were discussed in relation to the role of cognition in the learning of these motor skills and the influence of the subjects related background experiences.

Characterisation and comparison of bovine RNA polymerase III promoters for RNA interference

The characterisation of novel bovine RNA polymerase III promoters for the expression of short hairpin RNAs for gene silencing resulted in the identification of a highly efficient promoter sequence. The replication of bovine viral diarrhea virus was them suppressed using short hairpin RNAs expressed form this promoter in vitro.

10 mM glucosamine prevents activation of proADAMTS5 (aggrecanase-2) in transfected cells by interference with post-translational modification of furin

Objective
Glucosamine has been previously shown to suppress cartilage aggrecan catabolism in explant cultures. We determined the effect of glucosamine on ADAMTS5 (a disintegrin-like and metalloprotease domain (reprolysin type) with thrombospondin type-1 motifs 5), a major aggrecanase in osteoarthritis, and investigated a potential mechanism underlying the observed effects.

Design
HEK293F and CHO-K1 cells transiently transfected with ADAMTS5 cDNA were treated with glucosamine or the related hexosamine mannosamine. Glucosamine effects on FURIN transcription were determined by quantitative RT-PCR. Effects on furin-mediated processing of ADAMTS5 zymogen, and aggrecan processing by glucosamine-treated cells, were determined by western blotting. Post-translational modification of furin and N-glycan deficient furin mutants generated by site-directed mutagenesis was analyzed by western blotting, and the mutants were evaluated for their ADAMTS5 processing ability in furin-deficient CHO-RPE.40 cells.

Results
Ten mM glucosamine and 5–10 mM mannosamine reduced excision of the ADAMTS5 propeptide, indicating interference with the propeptide excision mechanism, although mannosamine compromised cell viability at these doses. Although glucosamine had no effect on furin mRNA levels, western blot of furin from glucosamine-treated cells suggested altered post-translational modification. Glucosamine treatment led to decreased glycosylation of cellular furin, with reduced furin autoactivation as the consequence. Recombinant furin treated with peptide N-glycanase F had reduced activity against a synthetic peptide substrate. Indeed, site-directed mutagenesis of two furin N-glycosylation sites, Asn387 and Asn440, abrogated furin activation and this mutant was unable to rescue ADAMTS5 processing in furin-deficient cells.

Conclusions
Ten mM glucosamine reduces excision of the ADAMTS5 propeptide via interference with post-translational modification of furin and leads to reduced aggrecanase activity of ADAMTS5.

Viral RNA silencing suppressors (RSS) : novel strategy of viruses to ablate the host RNA interference (RNAi) defense system

Pathogenic viruses have developed a molecular defense arsenal for their survival by counteracting the host anti-viral system known as RNA interference (RNAi). Cellular RNAi, in addition to regulating gene expression through microRNAs, also serves as a barrier against invasive foreign nucleic acids. RNAi is conserved across the biological species, including plants, animals and invertebrates. Viruses in turn, have evolved mechanisms that can counteract this anti-viral defense of the host. Recent studies of mammalian viruses exhibiting RNA silencing suppressor (RSS) activity have further advanced our understanding of RNAi in terms of host–virus interactions. Viral proteins and non-coding viral RNAs can inhibit the RNAi (miRNA/siRNA) pathway through different mechanisms. Mammalian viruses having dsRNA-binding regions and GW/WG motifs appear to have a high chance of conferring RSS activity. Although, RSSs of plant and invertebrate viruses have been well characterized, mammalian viral RSSs still need in-depth investigations to present the concrete evidences supporting their RNAi ablation characteristics. The information presented in this review together with any perspective research should help to predict and identify the RSS activity-endowed new viral proteins that could be the potential targets for designing novel anti-viral therapeutics.

Mediated hegemony : interference in the post-Saddam Iraqi media sector

The toppling of Saddam in 2003 brought with it the re-emergence of the free press in Iraq. This has seen Iraq shift from only a handful of state media outlets that served as propaganda machines, to a vast array of Iraqi-owned newspapers, radio stations and television channels which are being fervently produced and avidly consumed across the nation. As is to be expected, there are several problems that have accompanied such a divergent, ad-hoc and highly volatile media landscape. Leaving aside important issues such as the dangers faced by Iraqi journalists and the lack of appropriate press laws, this paper focuses instead on the influence of both foreign and domestic political bodies on the post-Saddam Iraqi media sector. Among the foreign influences are Iran, Saudi Arabia and the United States, all of which fund, control and manipulate various Iraqi media outlets. Not surprisingly, the United States has been the most active, using both overt and clandestine propaganda methods as well as forced closure to control the Iraqi media sector. Unfortunately, such measures are not limited to those governments which exist outside Iraq’s borders, with both the Iraqi government and the Kurdish regional authority having used similar means to control and even silence Iraq’s nascent public sphere. This paper concludes by noting the irony of limiting press freedoms in Iraq during this crucial phase in its transition from despotism to democracy.

Manufacturing consent in Iraq : interference in the post-Saddam media sector

The toppling of Saddam Hussein in 2003 saw Iraq's media sector shift from a handful of state-run media outlets that served as propaganda machines, to a vast array of Iraqi-owned newspapers, radio stations and television channels which are being fervently produced and avidly consumed nationally. Not unexpectedly, several problems have accompanied this divergent, ad-hoc and highly volatile mediascape. Although recognizing important factors, including dangers faced by Iraqi journalists, and the dearth of appropriate press laws, this article focuses instead on attempts by certain key foreign and domestic political bodies to manufacture consent in Iraq via their interference in the post-Saddam media sector. These foreign influences are Iran, Saudi Arabia and the United States, each of which funds, controls and manipulates different Iraqi media outlets. Not surprisingly, the United States has been the most active in this respect, utilizing both overt and clandestine propaganda techniques as well as forced closures to control the Iraqi media sector. Unfortunately, measures such as these are not limited to foreign governments: both the Iraqi government and the Kurdish Regional Government have used similar means to control and silence Iraq's nascent public sphere. The article concludes by noting the irony of limited press freedom in Iraq during this crucial phase of its transition from despotism to democracy.

Retroactive interference and mental practice effects on motor performance : a pilot study

This study examined the effect of similar versus dissimilar retroactive interference on the mental practice effects for performing a novel motor skill. Research has shown that mental practice of a motor task can interfere with learning and performance of the task; however, little is known about how different retroactive interference activities affect mental practice effects. 90 volunteers ages 18 to 51 years (M=26.8, SD=9.6) completed a pre-test and post-test of 10 sets of five trials of a throwing task with the non-preferred hand. In the practice phase, participants mentally practiced the throwing task and then mentally practiced a task that was similar, dissimilar, or completed an unrelated reading task. Performance for all groups improved from pre- to post-test; however, there were no differences in increases for the three groups. The findings suggest that mental practice of similar and dissimilar tasks produced no significant interference in performance.

RNA interference : more than a research tool in the vertebrates' adaptive immunity

In recent years, RNA silencing, usage of small double stranded RNAs of ~21 – 25 base pairs to regulate gene expression, has emerged as a powerful research tool to dissect the role of unknown host cell factors in this 'post-genomic' era. While the molecular mechanism of RNA silencing has not been precisely defined, the revelation that small RNA molecules are equipped with this regulatory function has transformed our thinking on the role of RNA in many facets of biology, illustrating the complexity and the dynamic interplay of cellular regulation. As plants and invertebrates lack the protein-based adaptive immunity that are found in jawed vertebrates, the ability of RNA silencing to shut down gene expression in a sequence-specific manner offers an explanation of how these organisms counteract pathogen invasions into host cells. It has been proposed that this type of RNA-mediated defence mechanism is an ancient form of immunity to offset the transgene-, transposon- and virus-mediated attack. However, whether 1) RNA silencing is a natural immune response in vertebrates to suppress pathogen invasion; or 2) vertebrate cells have evolved to counteract invasion in a 'RNA silencing' independent manner remains to be determined. A number of recent reports have provided tantalizing clues to support the view that RNA silencing functions as a physiological response to regulate viral infection in vertebrate cells. Amongst these, two manuscripts that are published in recent issues of Science and Immunity, respectively, have provided some of the first direct evidences that RNA silencing is an important component of antiviral defence in vertebrate cells. In addition to demonstrating RNA silencing to be critical to vertebrate innate immunity, these studies also highlight the potential of utilising virus-infection systems as models to refine our understanding on the molecular determinants of RNA silencing in vertebrate cells.