Effect of asymmetry in the restoring force of the "click" mechanism in insect flight

The aim of this paper is to examine the effect of asymmetry in the force-deflection characteristics of an insect flight mechanism on its nonlinear dynamics. An improved simplified model for insect flight mechanism is suggested and numerical methods are used to study its dynamics. The range at which the mechanism may operate is identified. The asymmetry can lead to differences in the velocity in the upward and downward movements which can be beneficial for the insect flight

Key actors in driving behavioural change in relation to on-farm biosecurity; a Northern Ireland perspective

Background: Agriculture and farming are valued contributors to local economy in Northern Ireland (NI). There is limited knowledge about farmers’ behaviours and attitudes towards disease biosecurity measures. As part of a larger project, a scenario-based workshop with key stakeholders was organised by the Agri-Food and Biosciences Institute (AFBI)-NI in December 2015. Results: A total of 22 participants belonging to 12 different institutions took part in the workshop. Participants were presented with an overview of previously conducted biosecurity research in NI and England. In small groups, participants were subsequently asked to discuss and give their opinions about a series of questions across four key areas in a semi-structured approach with an external facilitator. The key areas were 1- disease risk perception at the farm level; 2-perceived barriers to implementing on farm biosecurity measures; 3- avenues to successful behaviour change and 4-key industry responsibilities and roles. The discussion showed that training in biosecurity for farmers is important and necessary. Training was recommended to be provided by veterinary surgeons, preferably via a face-to-face format. The discussion addressing disease disclosure proved particularly challenging between those who were prospective buyers of cattle, and those who sold cattle. Conclusions: This workshop provided a unique and invaluable insight into key issues regarding farm level biosecurity activities. From a policy perspective, delivering improved on-farm biosecurity must be addressed via a multidisciplinary approach. This can only be achieved with active involvement, commitment and support of a number of key industry and government stakeholders

Mutual Fund Theorem for continuous time markets with random coefficients

We study the optimal investment problem for a continuous time incomplete market model such that the risk-free rate, the appreciation rates and the volatility of the stocks are all random; they are assumed to be independent from the driving Brownian motion, and they are supposed to be currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities; more precisely, it is shown that the supremum of expected utilities can be achieved on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities.Comment: 17 page

Tris-N-alkylpyridinium-functionalised cyclotriguaiacylene hosts as axles in branched [4]pseudorotaxane formation

A series of [4]pseudorotaxanes composed of three-way axle threads based on the cyclotriguaiacylene family of crown-shaped cavitands and three threaded macrocyclic components has been achieved. These exploit the strong affinity for electron-poor alkyl-pyridinium units to reside within the electron-rich cavity of macrocycles, in this case dimethoxypillar[5]arene (DMP). The branched [4]pseudorotaxane= assemblies {(DMP)3∙L}3+,where L = N-alkylated derivatives of the host molecule (±)-tris-(isonicotinoyl)cyclotriguaiacylene, were characterised by NMR spectroscopy and mass spectrometry, and an energy-minimised structure of {(DMP)3∙(tris-(N-propyl-isonicotinoyl)cyclotriguaiacylene)}3+ was calculated. Crystal structures of N-ethyl-isonicotinoyl)cyclotriguaiacylene hexafluorophosphate and N-propyl-isonicotinoyl)cyclotriguaiacylene hexafluorophosphate each show ‘hand-shake’ self-inclusion motifs occurring between the individual cavitands

T-cell contact-dependent regulation of CC and CXC chemokine production in monocytes through differential involvement of NFκB: implications for rheumatoid arthritis

We and others have reported that rheumatoid arthritis (RA) synovial T cells can activate human monocytes/macrophages in a contact-dependent manner to induce the expression of inflammatory cytokines, including tumour necrosis factor alpha (TNFα). In the present study we demonstrate that RA synovial T cells without further activation can also induce monocyte CC and CXC chemokine production in a contact-dependent manner. The transcription factor NFκB is differentially involved in this process as CXC chemokines but not CC chemokines are inhibited after overexpression of IκBα, the natural inhibitor of NFκB. This effector function of RA synovial T cells is also shared by T cells activated with a cytokine cocktail containing IL-2, IL-6 and TNFα, but not T cells activated by anti-CD3 cross-linking that mimics TCR engagement. This study demonstrates for the first time that RA synovial T cells as well as cytokine-activated T cells are able to induce monocyte chemokine production in a contact-dependent manner and through NFκB-dependent and NFκB-independent mechanisms, in a process influenced by the phosphatidyl-inositol-3-kinase pathway. Moreover, this study provides further evidence that cytokine-activated T cells share aspects of their effector function with RA synovial T cells and that their targeting in the clinic has therapeutic potential

Aural toilet (ear cleaning) for chronic suppurative otitis media

BACKGROUND: Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media (COM), is a chronic inflammation and often polymicrobial infection (involving more than one micro-organism) of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Aural toileting is a term describing a number of processes for manually cleaning the ear. Techniques used may include dry mopping (with cotton wool or tissue paper), suction clearance (typically under a microscope) or irrigation (using manual or automated syringing). Dry mopping may be effective in removing mucopurulent discharge. Compared to irrigation or microsuction it is less effective in removing epithelial debris or thick pus. Aural toileting can be used alone or in addition to other treatments for CSOM, such as antibiotics or topical antiseptics. OBJECTIVES: To assess the effects of aural toilet procedures for people with CSOM. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020. SELECTION CRITERIA: We included randomised controlled trials (RCTs) with at least a one-week follow-up involving people (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. We included any aural toileting method as the intervention, at any frequency and for any duration. The comparisons were aural toileting compared with a) placebo or no intervention, and b) any other aural toileting method. We analysed trials in which background treatments were used in both arms (e.g. topical antiseptics or topical antibiotics) separately. DATA COLLECTION AND ANALYSIS: We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at between one week and up to two weeks, two weeks to up to four weeks, and after four weeks; health-related quality of life using a validated instrument; and ear pain (otalgia) or discomfort or local irritation. Secondary outcomes were hearing, serious complications, and the adverse events of ear bleeding and dizziness/vertigo/balance problems. MAIN RESULTS: We included three studies with a total of 431 participants (465 ears), reporting on two comparisons. Two studies included only children with CSOM in the community (351 participants) and the other study (80 participants) included children and adults with chronic ear discharge for at least six weeks. None of the included studies reported the outcomes of health-related quality of life, ear pain or the adverse event of ear bleeding. Daily aural toileting (dry mopping) versus no treatment Two studies (351 children; 370 ears) compared daily dry mopping with no treatment. Neither study presented results for resolution of ear discharge at between one and up to two weeks or between two to four weeks. For resolution of ear discharge after four weeks, one study reported the results per person. We are very uncertain whether there is a difference at 16 weeks (risk ratio (RR) 1.01, 95% confidence interval (CI) 0.60 to 1.72; 1 study; 217 participants) because the certainty of the evidence is very low. No results were reported for the adverse events of dizziness, vertigo or balance problems. Only one study reported serious complications, but it was not clear which group these patients were from, or whether the complications occurred pre- or post-treatment. One study reported hearing, but the results were presented by treatment outcome rather than by treatment group so it is not possible to determine whether there is a difference between the two groups. Daily aural toileting versus single aural toileting on top of topical ciprofloxacin One study (80 participants; 95 ears) compared daily aural toileting (suction) with administration of topical antibiotic (ciprofloxacin) ear drops in a clinic, to a single aural toileting (suction) episode followed by daily self-administered topical antibiotic drops, in participants of all ages. We are unsure whether there is a difference in resolution of ear discharge at between one and up to two weeks (RR 1.09, 95% CI 0.91 to 1.30; 1 study; 80 participants) because the certainty of the evidence is very low. There were no results reported for resolution of ear discharge at between two to four weeks. The results for resolution of ear discharge after four weeks were presented by ear, not person, and could not be adjusted to by person. One patient in the group with single aural toileting and self administration of topical antibiotic ear drops reported the adverse event of dizziness, which the authors attributed to the use of cold topical ciprofloxacin. It is very uncertain whether there is a difference between the groups (RR 0.33, 95% CI 0.01 to 7.95; 1 study; 80 participants, very low-certainty). No results were reported for the other adverse events of vertigo or balance problems, or for serious complications. The authors only reported qualitatively that there was no difference between the two groups in hearing results (very low-certainty). AUTHORS' CONCLUSIONS: We are very uncertain whether or not treatment with aural toileting is effective in resolving ear discharge in people with CSOM, due to a lack of data and the poor quality of the available evidence. We also remain uncertain about other outcomes, including adverse events, as these were not well reported. Similarly, we are very uncertain whether daily suction clearance, followed by antibiotic ear drops administered at a clinic, is better than a single episode of suction clearance followed by self-administration of topical antibiotic ear drops

On Lagrangian mechanics and the implicit material point method for large deformation elasto-plasticity

The material point method is ideally suited to modelling problems involving large deformations where conventional mesh-based methods would struggle. However, total and updated Lagrangian approaches are unsuitable and non-ideal, respectively, in terms formulating equilibrium for the method. This is due to the basis functions, and particularly the derivatives of the basis functions, of material point methods normally being dened based on an unformed, and sometimes regular, background mesh. It is possible to map the basis function spatial derivatives using the deformation at a material point but this introduces additional algorithm complexity and computational expense. This paper presents a new Lagrangian statement of equilibrium which is ideal for material point methods as it satises equilibrium on the undeformed background mesh at the start of a load step. The formulation is implemented using a quasi-static implicit algorithm which includes the derivation of the consistent tangent to achieve optimum convergence of the global equilibrium iterations. The method is applied to a number of large deformation elasto-plastic problems, with a specic focus of the convergence of the method towards analytical solutions with the standard, generalised interpolation and CPDI2 material point methods. For the generalised interpolation method, dierent domain updating methods are investigated and it is shown that all of the current methods are degenerative under certain simple deformation elds. A new domain updating approach is proposed that overcomes these issues. The proposed material point method framework can be applied to all existing material point methods and adopted for implicit and explicit analysis, however its advantages are mainly associated with the former

High-efficiency gene transfer into nontransformed cells: utility for studying gene regulation and analysis of potential therapeutic targets

The elucidation of the signalling pathways involved in inflammatory diseases, such as rheumatoid arthritis, could provide long sought after targets for therapeutic intervention. Gene regulation is complex and varies depending on the cell type, as well as the signal eliciting gene activation. However, cells from certain lineages, such as macrophages, are specialised to degrade exogenous material and consequently do not easily transfect. Methods for high-efficiency gene transfer into primary cells of various lineages and disease states are desirable, as they remove the uncertainties associated with using transformed cell lines. Significant research has been undertaken into the development of nonviral and viral vectors for basic research, and as vehicles for gene therapy. We briefly review the current methods of gene delivery and the difficulties associated with each system. Adenoviruses have been used extensively to examine the role of various cytokines and signal transduction molecules in the pathogenesis of rheumatoid arthritis. This review will focus on the involvement of different signalling molecules in the production of tumour necrosis factor alpha by macrophages and in rheumatoid synovium. While the NF-kappaB pathway has proven to be a major mediator of tumour necrosis factor alpha production, it is not exclusive and work evaluating the involvement of other pathways is ongoing

Genetic and environmental influences on serum oxylipins, endocannabinoids, bile acids and steroids

Lipid bioactivity is a result of direct action and the action of lipid mediators including oxylipins, endocannabinoids, bile acids and steroids. Understanding the factors contributing to biological variation in lipid mediators may inform future approaches to understand and treat complex metabolic diseases. This research aims to determine the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism. This study recruited 138 monozygotic (MZ) and dizygotic (DZ) twins aged 18-65 years and measured serum oxylipins, endocannabinoids, bile acids and steroids using liquid chromatography mass-spectrometry (LC-MS). In this classic twin design, the similarities and differences between MZ and DZ twins are modelled to estimate the contribution of genetic and environmental influences to variation in lipid mediators. Heritable lipid mediators included the 12-lipoxygenase products 12-hydroxyeicosatetraenoic acid [0.70 (95% CI: 0.12,0.82)], 12-hydroxyeicosatetraenoic acid [0.73 (95% CI: 0.30,0.83)] and 14‑hydroxy-docosahexaenoic acid [0.51 (95% CI: 0.07,0.71)], along with the endocannabinoid docosahexaenoy-lethanolamide [0.52 (95% CI: 0.15,0.72)]. For others such as 13-hydroxyoctadecatrienoic acid and lithocholic acid the contribution of environment to variation was stronger. With increased understanding of lipid mediator functions in health, it is important to understand the factors contributing to their variance. This study provides a comprehensive analysis of lipid mediators and extends pre-existing knowledge of the genetic and environmental influences on the human lipidome