Psychological and cumulative cardiovascular effects of repeated angry ruminaton and visuospatial suppression

Brooding rumination is associated with depressed mood, increased negative affect, prolonged anger and inhibited cardiovascular (CV) recovery. Distraction from rumination on a stressful interpersonal encounter is associated with faster CV recovery and decreased negative affect. Studies have suggested that a concurrent visuospatial (VS) task inhibits the maintenance of imagery associated with the perseveration of intrusive negative memories. 120 healthy participants were recruited for the study. As an analogue of repeated angry rumination, the authors explored the effects of repeated visual recall of a provocative confederate and the subsequent impact of two visuospatial (VS) distraction tasks on negative affect, blood pressure (BP) and heart rate (HR). Repeated recall of the provocation generated repeatedly elevated HR with a cumulative trend that may have CV disease risk implications for chronic ruminators. VS distraction did not aid recovery compared with the Control task.

Fighting fatigue whilst fighting bushfire : an overview of factors contributing to firefighter fatigue during bushfire suppression

Aching muscles and joints, lethargy, and sleepiness are all signs of firefighter fatigue during bushfire suppression. If not managed, fatigue may lead to injury or illness for the individual, which may also compromise the safety and productivity of their crew. Understanding the many sources of firefighter fatigue is, therefore, fundamental for all Australian fire agencies. This article will briefly address  several factors thought to contribute to firefighter fatigue including; sleep loss, firefighter’s work activity, their hydration, and nutrition, the hot and smoky  working environment, firefighter’s physical fitness and their experience. This brief overview draws on findings from firefighting research and the broader scientific literature.

Fighting with fire : how bushfire suppression can impact on fire fighters' health

Background: Each year bushfire threatens Australia’s rural, forest, and urban-rural areas. Australia’s rural fire fighters work to curtail this threat in hot, smoky conditions, often at risk to their physical health. General practitioners, especially in rural areas, can help preserve the health of fire fighters during the fire season by understanding the stressors they face on the fireground.

Objective: This article outlines how the key fireground stressors of work intensity and duration, heat (from the weather, the fire, and the fire fighter’s own exertion) and smoke impact on the health of fire fighters. Practical advice for GPs treating Australia’s rural fire fighters is also included.

Discussion: General practitioners can help preserve fire fighters' health during bushfire suppression in a number of ways, including: identifying fire fighters at risk of cardiac distress during physical labour and educating them about the early warning signs; advocating regular exercise; discouraging smoking; and promoting the benefits of maintaining fluid, carbohydrate, and electrolyte levels during a shift.

Convection suppression in an attic shaped enclosure

In recent times there has been growing interest in the integration of solar collectors, for water heating, into the façade of buildings. However, the design methodology of these devices remains largely the same as typical “stand-alone” collectors. As such it is still common for materials with a high thermal resistance to be used for insulating the rear surface of these collectors.

Unlike a “stand-alone” solar collector that is exposed to the atmosphere at all faces; a building integrated system allows the opportunity for air to act as an insulator at the rear surface of the solar collector. The use of convection suppression devices has been widely discussed in the literature as a means of reducing natural convection heat loss from the front surface of glazed solar collectors. However in this study the use of baffles in an attic was examined as a means of suppressing heat loss by natural convection from the rear surface of a roof-integrated solar collector. The aim of the study was to examine whether the use of baffles would allow the cost of building integrated collectors to be reduced by removing the cost of insulating material.

To determine the effect of baffles in the attic space at the rear surface of the collector, a 3-dimensional triangular cross sectioned enclosure with a vertical aspect ratio of 0.5 and a horizontal aspect ratio of 3.3 was modelled. The flow patterns and heat transfer in the enclosure were determined for Grashof Numbers in the range of 106 to 107 using a commercially available finite volume CFD solver.
It was found that the use of a single adiabatic baffle mounted vertically downwards from the apex, and extending the length of the enclosure, would alter the flow such that the heat transfer due to natural convection was reduced with respect to the length of the baffle.

Furthermore, it was observed that a series of convection cells, not previously reported in the literature, appeared to exist along the length of the enclosure. As such, it may be possible to derive additional benefit in reducing the heat transfer by adding lateral baffles in addition to the single longitudinal baffle modelled in this study.

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.

Suppression of natural convection heat transfer coefficients in an attic shaped enclosure

The use of convection suppression devices has been widely discussed in the literature as a means of reducing natural convection heat loss from enclosed spaces. In this study the use of a single baffle was examined as a possible low cost means of suppressing heat loss by natural convection in an attic shaped enclosure.

Recently the authors experimentally demonstrated that the natural convection heat transfer for an attic shaped enclosure with Grashof Numbers in the range of 107 to 109 [1] could be predicted using a correlation in the literature developed for Grashof Numbers in the range 105 and 106 [2]. However, in this study the impact of adding a single baffle to the enclosure was examined. It was found that the heat transfer coefficient changes with increasing baffle length, and can be predicted using a modified form of the correlation presented in [1], as shown in Eq. (1).

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.

Pre-cursors to physical employment standards for rural tanker-based bushfire suppression work

This thesis quantified the physical demands of Australian rural bushfire suppression and developed a controlled bushfire simulation suitable for ongoing bushfire research. The findings of this thesis will be used to develop physical employment standards and OH&S strategies to protect the 200,000 volunteer firefighters Australia wide.

Identification and characterization of Kava-derived compounds mediating TNF-alpha suppression

There is a substantial unmet need for new classes of drugs that block TNF-α-mediated inflammation, and particularly for small molecule agents that can be taken orally. We have screened a library of natural products against an assay measuring TNF-α secretion in lipopolysaccharide-stimulated THP-1 cells, seeking compounds capable of interfering with the TNF-α-inducing transcription factor lipopolysaccharide-induced TNF-α factor. Among the active compounds were several produced by the kava plant (Piper mysticum), extracts of which have previously been linked to a range of therapeutic effects. When tested in vivo, a representative of these compounds, kavain, was found to render mice immune to lethal doses of lipopolysaccharide. Kavain displays promising pharmaceutical properties, including good solubility and high cell permeability, but pharmacokinetic experiments in mice showed relatively rapid clearance. A small set of kavain analogs was synthesized, resulting in compounds of similar or greater potency in vitro compared with kavain. Interestingly, a ring-opened analog of kavain inhibited TNF-α secretion in the cell-based assay and suppressed lipopolysaccharide-induced TNF-α factor expression in the same cells, whereas the other compounds inhibited TNF-α secretion without affecting lipopolysaccharide-induced TNF-α factor levels, indicating a potential divergence in mechanism of action.