Additional studies of quasi-optimum feedback control techniques

Quasi-optimal control technique for space vehicle attitude, bounded acceleration rendezvous in free space, and aircraft landing proble

Characterization of a high-power tapered semiconductor amplifier system

We have characterized a semiconductor amplifier laser system which provides up to 200mW output after a single-mode optical fiber at 780nm wavelength. The system is based on a tapered semiconductor gain element, which amplifies the output of a narrow-linewidth diode laser. Gain and saturation are discussed as a function of operating temperature and injection current. The spectral properties of the amplifier are investigated with a grating spectrometer. Amplified spontaneous emission (ASE) causes a spectral background with a width of 4nm FWHM. The ASE background was suppressed to below our detection limit by a proper choice of operating current and temperature, and by sending the light through a single-mode optical fiber. The final ASE spectral density was less than 0.1nW/MHz, i.e. less than 0.2 % of the optical power. Related to an optical transition linewidth of $\Gamma/2\pi=6$ MHz for rubidium, this gives a background suppression of better than -82dB. An indication of the beam quality is provided by the fiber coupling efficiency up to 59 %. The application of the amplifier system as a laser source for atom optical experiments is discussed

The Potential Added Value of Novel Hearing Therapeutics: An Early Health Economic Model for Hearing Loss

OBJECTIVE: To construct an early health economic model to assess the potential added value of novel hearing therapeutics, compared with the current standard of care. We use idiopathic sudden sensorineural hearing loss (ISSNHL) as a case example, because it is a lead indication for several emerging hearing therapeutics. METHODS: A decision analytic model was developed to assess the costs and effects of using novel hearing therapeutics for patients with ISSNHL. This was compared to the current standard of care. Input data were derived from literature searches and expert opinion. The study adopted a healthcare perspective of the UK National Health Service. Four analyses were conducted: 1) headroom, 2) scenario, 3) threshold, 4) sensitivity. RESULTS: The decision analytic model showed that novel therapeutics for ISSNHL have potential value both in terms of improved patient outcomes, as well as incremental net monetary benefit (iNMB). The base case analysis revealed an iNMB of £39,032 for novel therapeutics compared with the current standard of care. Results of the threshold and scenario analysis revealed that age of treatment and severity of ISSNHL are major determinants of iNMB for novel therapeutics. CONCLUSION: This article describes the first health economic model for novel therapeutics for hearing loss; and shows that novel hearing therapeutics can be cost-effective under NICE's cost-effectiveness threshold, with considerable room for improvement in the current standard of care. Our model can be used to inform the development of cost-effective hearing therapeutics; and help decision makers decide which therapeutics represent value for money

Antibiotic prescribing in patients with self-reported sore throat.

Objectives: To investigate the predictors of general practitioner (GP) consultation and antibiotic use in those developing sore throat. Methods: We conducted a prospective population-based cohort study on 4461 participants in two rounds (2010-11) from 1897 households. Results: Participants reported 2193 sore throat illnesses, giving a community sore throat incidence of 1.57/ person-year. 13% of sore throat illnesses led to a GP consultation and 56% of these consultations led to antibiotic use. Participants most likely to have sore throats included women and children (e.g. school compared with retirement age); adjusted incidence rate ratio (aIRR) of 1.33 and 1.52, respectively. Participants with sore throat were more likely to consult their GP if they were preschool compared with retirement age [adjusted OR (aOR) 3.22], had more days of sore throat (aOR 1.11), reported more severe pain (aOR 4.24) or reported fever (aOR 3.82). Antibiotics were more often used by chronically ill individuals (aOR 1.78), those reporting severe pain (aOR 4.14), those reporting fever (aOR 2.58) or children with earache (aOR 1.85). Among those who consulted, males and adults who reported feeling anxious were more likely to use antibiotics; aOR 1.87 and 5.36, respectively. Conclusions: Only 1 in 10 people who have a sore throat see a doctor and more than half of those attending get antibiotics. Further efforts to curb antibiotic use should focus on reducing initial GP consultations through public information promoting safe self-management, targeted at groups identified above as most likely to attend with sore throats

Antibiotic usage in chronic rhinosinusitis: analysis of national primary care electronic health records

Background : The aim of this study was to analyse rates of antibiotic usage in chronic rhinosinusitis (CRS) in primary care in England and Wales and to identify trends in the choice of antibiotics prescribed. Methods : We used linked data from primary care EHRs, with diagnoses coded using the Read terminology (Clinical Practice Research Datalink) from consenting general practices, with (2) hospital care administrative records (Hospital Episode Statistics, HES recorded using ICD-10). Results : From the total of 88,317 cases of CRS identified, 40,462 (46%) had an antibiotic prescription within 5 days of their first CRS diagnosis. Of patients receiving a first line antibiotic within 5 days of CRS diagnosis, over 80%, in each CRS group, received a subsequent prescription for an antibiotic. Within 5 years of diagnosis, 9% are estimated to have had 5 or more antibiotics within 5 days of a CRS-related consultation. With data spanning almost 20 years, it was possible to discern trends in antibiotics prescriptions, with a clear increasing trend towards macrolide and tetracycline prescribing evident. Conclusions : While antibiotics may have been prescribed for acute exacerbations, we have found high rates of repeated antibiotic prescription in some patients with CRS in primary care. There is a need for stronger evidence on the role of antibiotics in CRS management

What are the requirements for developing a successful national registry of auditory implants? A qualitative study

OBJECTIVES: Hearing loss is an area of unmet need, and industry is targeting this field with a growing range of surgically implanted hearing devices. Currently, there is no comprehensive UK registry capturing data on these devices; in its absence, it is difficult to monitor clinical and cost-effectiveness and develop national policy. Recognising that developing such a registry faces considerable challenges, it is important to gather opinions from stakeholders and patients. This paper builds on our systematic review on surgical registry development and aims to identify the specific requirements for developing a successful national registry of auditory implants. DESIGN: Qualitative study. PARTICIPANTS: Data were collected in two ways: (1) semistructured interviews with UK professional stakeholders; and (2) focus groups with patients with hearing loss. The interview and focus group schedules were informed by our systematic review on registry development. Data were analysed using directed content analysis. Judges mapped the themes obtained against a conceptual framework developed from our systematic review on registry development. The conceptual framework consisted of five categories for successful registry development: (1) planning, (2) registry governance, (3) registry dataset, (4) anticipating challenges, (5) implementing solutions. RESULTS: Twenty-seven themes emerged from 40 semistructured interviews with professional stakeholders and 18 themes emerged from three patient focus groups. The most important factor for registry success was high rates of data completion. Benefits of developing a successful registry of auditory implants include: strengthening the evidence base and regulation of auditory implants, driving quality and safety improvements, increased transparency, facilitating patient decision-making and informing policy and guidelines development. CONCLUSIONS: This study identifies the requirements for developing a successful national registry of auditory implants, benefiting from the involvement of numerous professional stakeholder groups and patients with hearing loss. Our approach may be used internationally to inform successful registry development

Antibiotic usage in chronic rhinosinusitis: analysis of national primary care electronic health records

BACKGROUND: The aim of this study was to analyse rates of antibiotic usage in chronic rhinosinusitis (CRS) in primary care in England and Wales and to identify trends in the choice of antibiotics prescribed. METHODS: We used linked data from primary care EHRs, with diagnoses coded using the Read terminology (Clinical Practice Research Datalink) from consenting general practices, with (2) hospital care administrative records (Hospital Episode Statistics, HES recorded using ICD-10). RESULTS: From the total of 88,317 cases of CRS identified, 40,462 (46%) had an antibiotic prescription within 5 days of their first CRS diagnosis. Of patients receiving a first line antibiotic within 5 days of CRS diagnosis, over 80%, in each CRS group, received a subsequent prescription for an antibiotic. Within 5 years of diagnosis, 9% are estimated to have had 5 or more antibiotics within 5 days of a CRS-related consultation. With data spanning almost 20 years, it was possible to discern trends in antibiotics prescriptions, with a clear increasing trend towards macrolide and tetracycline prescribing evident. CONCLUSIONS: While antibiotics may have been prescribed for acute exacerbations, we have found high rates of repeated antibiotic prescription in some patients with CRS in primary care. There is a need for stronger evidence on the role of antibiotics in CRS management

An ecological method for the sampling of nonverbal signalling behaviours of young children with profound and multiple learning disabilities (PMLD)

- Background: Profound and multiple learning disabilities (PMLD) are a complex range of disabilities that affect the general health and wellbeing of the individual and their capacity to interact and learn. - Method: We developed a new methodology to capture the nonsymbolic signalling behaviours of children with PMLD within the context of a face-to-face interaction with a caregiver to provide analysis at a micro-level of descriptive detail incorporating the use of the ELAN digital video software. - Conclusion: The signalling behaviours of participants in a natural, everyday interaction can be better understood with the use of this innovation in methodology, which is predicated on the ecology of communication. Recognition of the developmental ability of the participants is an integral factor within that ecology. The method presented establishes an advanced account of the modalities through which a child affected by PMLD is able to communicate

Third structure determination by powder diffractometry round robin (SDPDRR-3)

The results from a third structure determination by powder diffractometry (SDPD) round robin are discussed. From the 175 potential participants having downloaded the powder data, nine sent a total of 12 solutions (8 and 4 for samples 1 and 2, respectively, a tetrahydrated calcium tartrate and a lanthanum tungstate). Participants used seven different computer programs for structure solution (ESPOIR, EXPO, FOX, PSSP, SHELXS, SUPERFLIP, and TOPAS), applying Patterson, direct methods, direct space methods, and charge flipping approach. It is concluded that solving a structure from powder data remains a challenge, at least one order of magnitude more difficult than solving a problem with similar complexity from single-crystal data. Nevertheless, a few more steps in the direction of increasing the SDPD rate of success were accomplished since the two previous round robins: this time, not only the computer program developers were successful but also some users. No result was obtained from crystal structure prediction expert