Curculionidae (weevils) of the alpine zone of mount Kenya

Volume: XXVI

Distribution and host-specificity of a number of fleas collected in south and central Kenya

Volume: XXVI

Towards the noise reduction of piezoelectrical-driven synthetic jet actuators

This paper details an experimental investigation aimed at reducing the noise output of piezoelectrical-driven synthetic jet actuators without compromising peak jet velocity. Specifically, the study considers double-chamber ('back-to-back') actuators for anti-phase noise suppression and corrugated-lobed orifices as a method to enhance turbulent mixing of the jets to suppress jet noise. The study involved the design, manufacture and bench test of interchangeable actuator hardware. Hot-wire anemometry and microphone recordings were employed to acquire velocity and noise measurements respectively for each chamber configuration and orifice plate across a range of excitation frequencies and for a fixed input voltage. The data analysis indicated a 32% noise reduction (20 dBA) from operating a singlechamber, circular orifice SJA to a double-chamber, corrugated-lobed orifice SJA at the Helmholtz resonant frequency. Results also showed there was a small reduction in peak jet velocity of 7% (~3 m/s) between these two cases based on orifices of the same discharge area. Finally, the electrical-to-fluidic power conversion efficiency of the double-chamber actuator was found to be 15% across all orifice designs at the resonant frequency; approximately double the efficiency of a single-chamber actuator. This work has thus demonstrated feasible gains in noise reduction and power efficiency through synthetic jet actuator design

Active flow control systems architectures for civil transport aircraft

Copyright @ 2010 American Institute of Aeronautics and AstronauticsThis paper considers the effect of choice of actuator technology and associated power systems architecture on the mass cost and power consumption of implementing active flow control systems on civil transport aircraft. The research method is based on the use of a mass model that includes a mass due to systems hardware and a mass due to the system energy usage. An Airbus A320 aircraft wing is used as a case-study application. The mass model parameters are based on first-principle physical analysis of electric and pneumatic power systems combined with empirical data on system hardware from existing equipment suppliers. Flow control methods include direct fluidic, electromechanical-fluidic, and electrofluidic actuator technologies. The mass cost of electrical power distribution is shown to be considerably less than that for pneumatic systems; however, this advantage is reduced by the requirement for relatively heavy electrical power management and conversion systems. A tradeoff exists between system power efficiency and the system hardware mass required to achieve this efficiency. For short-duration operation the flow control solution is driven toward lighter but less power-efficient systems, whereas for long-duration operation there is benefit in considering heavier but more efficient systems. It is estimated that a practical electromechanical-fluidic system for flow separation control may have a mass up to 40% of the slat mass for a leading-edge application and 5% of flap mass for a trailing-edge application.This work is funded by the Sixth European Union Framework Programme as part of the AVERT project (Contract No. AST5-CT-2006-030914

Is Gly16Arg β₂ Receptor Polymorphism Related to Impulse Oscillometry in a Real-Life Asthma Clinic Setting?

PURPOSE: We evaluated whether Gly16Arg beta2-receptor genotype relates to impulse oscillometry (IOS) in a real-life clinic setting. METHODS: Patients with persistent asthma taking inhaled corticosteroid ± long-acting beta-agonist (ICS ± LABA) were evaluated. We compared genotype groups comprising either no Arg copies (i.e. GlyGly) versus one or two Arg copies (i.e. ArgArg or ArgGly). IOS outcomes included total airway resistance at 5 Hz (R5), central airway resistance at 20 Hz (R20), peripheral airway resistance (R5–R20), reactance at 5 Hz, area under reactance curve (AX) and resonant frequency (RF). In addition, we recorded ACQ-5 and salbutamol use. RESULTS: One hundred and twelve ICS-treated asthmatic patients (mean ICS dose 1238 µg/day), mean age 43 years, ACQ 2.34, FEV1 82 %, R5 177 % were identified—89 were also taking LABA. 61 patients were GlyGly, while 14 were ArgArg and 37 were ArgGly. There were no significant differences in IOS outcomes, ACQ or salbutamol use between the genotypes. The allelic risk (as odds ratio) for less well-controlled asthma (as ACQ > 1.5) was 1.1 (95 % CI 0.72–1.68) in relation to each Arg copy with a corresponding odds ratio for abnormal R5–R20 > 0.07kPA/l.s being 0.91 (95 % CI 0.57–1.44). 71 % of patients had an ACQ > 1.5 in the GlyGly group, versus 67 % in GlyArg/ArgArg group, with corresponding figures for abnormal R5–R20 > 0.07 kPa/l.s being 69 versus 73 %. CONCLUSION: In a real-life clinic setting for patients with poorly controlled persistent asthma taking ICS ± LABA, we found no evidence of any relationship of Gly16Arg to IOS, ACQ or salbutamol use

Nasal delivery of chitosan-DNA plasmid expressing epitopes of respiratory syncytial virus (RSV) induces protective CTL responses in BALB/c mice.

Respiratory syncytial virus (RSV), an important pathogen of the lower respiratory tract, is responsible for severe illness both in new born and young children and in elderly people. Due to complications associated with the use of the early developed vaccines, there is still a need for an effective vaccine against RSV. Most pathogens enter the body via mucosal surfaces and therefore vaccine delivery via routes such as the nasal, may well prove to be superior in inducing protective immune responses against respiratory viruses, since both local and systemic immunity can be induced by nasal immunisation. Previously we have shown that intradermal immunisation of a plasmid DNA encoding the CTL epitope from the M2 protein of RSV induced protective CTL responses. In the present study, the mucosal delivery of plasmid DNA formulated with chitosan has been investigated. Chitosan is a polysachharide consisting of copolymers of N-acetylglucosamine and glucosamine that is derived from chitin, a material found in the shells of crustacea. Intranasal immunisation with plasmid DNA formulated with chitosan induced peptide- and virus-specific CTL responses in BALB/c mice that were comparable to those induced via intradermal immunisation. Following RSV challenge of chitosan/DNA immunised mice, a significant reduction (P<0.001) in the virus load was observed in the lungs of immunised mice compared to that in the control group. These results indicate the potential of immunisation with chitosan-formulated epitope-based vaccines via the intranasal route

The virtual knee clinic - A tool to streamline new outpatient referrals

INTRODUCTION: Traditionally it has been the case for orthopaedic consultants to review GP referrals for the orthopaedic outpatient clinic where possible in amongst other clinical commitments. This could sometimes lead to unsuitable patients being reviewed and both patients and clinicians becoming frustrated. Building on the virtual fracture clinic, a new screening tool was implemented to streamline new referrals. The aim of this study is to investigate the change in patients given outpatient appointments following the introduction of a new streamlining protocol.METHODS: Referrals had to meet the criteria of BMI under 40 or evidence of weight loss effort, recent radiographs and appropriate clinical details in keeping with Getting It Right First Time (GIRFT). Consultant were given dedicated clinical time to review and either triage the patient to the most appropriate clinic type, or return the referral with advice to the GP. 10 months of data was collected prior to the protocol and 10 months after implementation.RESULTS: 1781 patients were referred pre-protocol with an average of 14.2% of these being returned. Post protocol there were 2110 patients referred with 31.2% returned. There was an increase in 195% of referrals returned to the GP (p &lt; 0.0001). The highest proportion of these was for mild to moderate osteoarthritis on the radiograph which has been proven to be unsuitable for intervention. At 12 month analysis there was no significant increase in patients re-referred to the service (p = 0.53) DISCUSSION: The new screening tool allows more appropriate referrals to be seen in clinic allowing less frustration to clinicians and patients by reducing therapeutic inertia. Furthermore it allows new referrals to be seen by the most appropriate sub-specialist. It allows advice to be given to GPs on further management for the patient. 619 appointments were saved. At a cost of £120 per appointment, this leads to a real terms cost saving of £74,280, with further savings in time and travel.</p