273 research outputs found

    A qualitative study evaluating experiences of a lifestyle intervention in men with prostate cancer undergoing androgen suppression therapy

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    BACKGROUND The severe iatrogenic hypogonadal state induced by medical castration used for treatment of prostate cancer is associated with adverse effects including fatigue, increased fracture risk, and a decrease in skeletal muscle function, which negatively impact quality of life. We have previously reported beneficial changes in healthy lifestyle behaviors, physical function and fatigue as a result of a novel combined exercise and dietary advice intervention (a lifestyle intervention) in men with prostate cancer on androgen suppression therapy (AST). The aim of this research was to conduct a qualitative evaluation of the lifestyle intervention in these men with advanced prostate cancer receiving androgen suppression therapy (AST). METHODS Twelve men with prostate cancer on AST took part in three focus groups in a UK higher education institution following the 12 week intervention. Sessions lasted between 45 and 60 minutes in duration. All discussions were audio-taped and transcribed. A framework analysis approach was applied to the focus group data. An initial coding framework was developed from a priori issues listed in the topic guide and extended and refined following initial familiarization with the focus group transcripts. Line by line indexing of the transcripts was undertaken iteratively to allow for the incorporation of new codes. Coded sections of text were grouped together (charted) into themes and subthemes prior to a further process of comparison and interpretation. RESULTS None of the participants involved in the trial were provided with information on how lifestyle changes might be beneficial to men with prostate cancer during the course of their standard medical treatment. We present novel findings that this intervention was considered beneficial for reducing anxiety around treatment and fear of disease progression. Men were supportive of the benefits of the intervention over conventional cancer survival discussion group arrangements as it facilitated peer support in addition to physical rehabilitation. CONCLUSIONS The benefits of lifestyle changes in men with prostate cancer are not well appreciated by care providers despite a range of benefits becoming apparent. Strategies to implement exercise and dietary interventions in standard care should be further evaluated. TRIAL REGISTRATION Current Controlled Trials ISRCTN88605738

    Reporting participation rates in studies of non-pharmacological interventions for patients with chronic obstructive pulmonary disease: a systematic review

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Optical frequency comb generation and applications in coherent optical communications

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    Optical frequency combs (OFCs) are a multi-wavelength source consisting of a series of sharp discrete spectral tones exhibiting broadband frequency coherence. Over the past decade, frequency combs have enabled significant developments in the fields of metrology, spectroscopy, microwave photonics and optical communications. Coherent communications in particular has seen significant interest in leveraging the coherence of OFCs to enable low-complexity and high-performance DSP. However, many existing comb generation techniques possess sub-optimal properties for coherent WDM systems with respect to their power-per-tone, optical signal to noise ratio (OSNR), spectral flatness and bandwidth. In addition, many applications of OFC frequency coherence have yet to be explored, particularly the potential benefits and limitations of OFCs for transmitter-side nonlinearity mitigation. There are two main focal points of this thesis. The first focus is on the generation of optical frequency combs specifically designed for the requirements of coherent WDM communications systems, with an emphasis on the optical fibre platform, high optical power-per-tone, high OSNR, flatness and broad bandwidths. To this end, an electro-optic-modulator-based comb generator was designed, numerically modelled and experimentally tested to generate an optical frequency comb spanning the C-band using tailored optical pulse shaping and fibre-based nonlinear mixers. In addition, a novel nonlinear fibre waveguide called silicon core fibre was modelled, tested and evaluated as an ultra-short nonlinear mixer for compact fibre comb generation architectures. The second focal point of this thesis is on the application of frequency combs in coherent communication systems. The efficacy of frequency comb sources for fibre nonlinearity mitigation was investigated numerically in the presence of various frequency noise impairments such as laser phase noise and frequency dither. A coherent recirculating loop testbed was used to experimentally investigate comb-based nonlinearity mitigation in various transmission scenarios

    RfaH Suppresses Small RNA MicA Inhibition of fimB Expression in Escherichia coli K-12

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    The phase variation (reversible on-off switching) of the type 1 fimbrial adhesin of Escherichia coli involves a DNA inversion catalyzed by FimB (switching in either direction) or FimE (on-to-off switching). Here, we demonstrate that RfaH activates expression of a FimB-LacZ protein fusion while having a modest inhibitory effect on a comparable fimB-lacZ operon construct and on a FimE-LacZ protein fusion, indicating that RfaH selectively controls fimB expression at the posttranscriptional level. Further work demonstrates that loss of RfaH enables small RNA (sRNA) MicA inhibition of fimB expression even in the absence of exogenous inducing stress. This effect is explained by induction of σE , and hence MicA, in the absence of RfaH. Additional work con- firms that the procaine-dependent induction of micA requires OmpR, as reported previously (A. Coornaert et al., Mol. Microbiol. 76:467–479, 2010, doi:10.1111/j.1365-2958.2010.07115.x), but also demonstrates that RfaH inhibition of fimB transcription is enhanced by procaine independently of OmpR. While the effect of procaine on fimB transcription is shown to be independent of RcsB, it was found to require SlyA, another known regulator of fimB transcription. These results demonstrate a complex role for RfaH as a regulator of fimB expression

    Understanding the reasons for non participation in self-manegement intervemtions amongst aptienrs with chronic conditions: addressing and increasing opportunities for patients with advanced chronic obstructive pulmonary disease to access self-management

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    Background In chronic obstructive pulmonary disease (COPD), understanding the problem of poor patient participation in evidence-based self-management (SM) and pulmonary rehabilitation (PR) programmes (together referred to as SM support programmes) is critical. This thesis aimed to improve understanding of poor patient participation and retention in these programmes; how participation might be improved; and how might patients be better supported with their SM. Methods Using the Medical Research Council guidance on complex interventions this thesis (1) quantified the ‘actual’ patient participation and completion rates; (2) explained, using theory, the factors that influenced participation in studies of SM support including the programmes among chronic disease and COPD patients; and (3) explored patient and expert stakeholders’ perspectives on the reasons for non-participation in SM support programmes, how participation might be improved, how might patients be supported with their SM. Results (1) Among 56 studies, high study participation rates and completion rates were seen however, the incomplete reporting of participant flow confused the problem of participation. (2) Among 31 studies, participation among patients with chronic disease including COPD was shown to be influenced by their ‘attitude’ and ‘perceived social influence/subjective norms’; ‘illness’ and ‘intervention perceptions’. (3) From 38 interviewees, besides patients’ beliefs, non-participation was also influenced by resignation and denial of the illness; health systems; and programme organisational factors. Professionals building relationships and supporting patients with their SM alongside programme organisational improvements might encourage patient participation in SM and the programmes. Conclusions Patient participation is a complex behaviour, besides socio-behavioural factors, participation behaviour can by influenced by a mix of several health system and programme organisational factors. Changing the behaviour of health professionals and indeed the wider health system, towards normalising a patient partnership approach, with implementation of SM support in routine care might help more patients to consider participation in their care and improve patient participation in COPD SM support programmes.The National Institute for Health Researc

    Scalable Bandwidth and High-Precision Spectral Measurement by Frequency Chirped Comb

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    A cost-effective scan technique enabling scalable measurement range is presented by injecting a sweep RF signal of 27.5-30 GHz into an electro-optic comb generator. The 10th-order harmonic scans over an extended span (275-300 GHz) where an ultra-narrow (Q >106) resonance is well-resolved with sub-MHz resolution

    The role of collaboration in the cognitive development of young children: a systematic review.

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    BACKGROUND: Collaboration is a key facilitator of cognitive development in early childhood; this review evaluates which factors mediate the impact of collaborative interactions on cognitive development in children aged 4-7 years. METHODS: A systematic search strategy identified relevant studies (n = 21), which assessed the role of ability on the relationship between collaboration and cognitive development. Other factors that interact with ability were also assessed: gender, sociability/friendship, discussion, age, feedback and structure. RESULTS: Immediate benefits of collaboration on cognitive development are highlighted for same-age peers. Collaborative interactions are beneficial for tasks measuring visual perception, problem-solving and rule-based thinking, but not for word-reading and spatial perspective-taking. Collaboration is particularly beneficial for lower-ability children when there is an ability asymmetry. High-ability children either regressed or did not benefit when paired with lower-ability participants. CONCLUSIONS: Overall, the studies included within this review indicate that brief one-off interactions can have a significant, positive effect on short-term cognitive development in children of infant school age. The longer-term advantages of collaboration are still unclear. Implications for practice and future research are discussed

    On the design of low phase noise and flat spectrum optical parametric frequency comb

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    Optical frequency combs (OFCs) have become increasingly pervasive in recent years, with their advantageous frequency coherence properties enabling significant developments in numerous fields, such as optical communications, spectroscopy, and microwave signal processing. Recent interest in OFC development emphasizes minimizing and mitigating phase noise of individual comb lines for high-quality signal generation, processing, and detection. Cavity-less electro-optic combs and parametric combs are attractive sources for these applications in that they permit flat spectra, tunable tone spacing, and robustness to temperature variations. Although previous research has demonstrated broadband parametric OFC generation, the scaling of the phase noise has not been systematically investigated. Here, we demonstrate a 25 GHz-spacing cavity-less parametric OFC generator and investigate the interaction between electronic and optical noise sources that affect its phase noise and linewidth. In addition, we study the optimal design of a nonlinear amplified loop mirror based pulse shaper with a focus on the impact of pump power on the signal-to-pedestal power ratio, which ultimately influences the spectral flatness and the optical signal-to-noise ratio (OSNR) after the parametric expansion. Notably, we design the OFC using all polarization-maintaining (PM) components, demonstrating the performance of PM highly nonlinear fibers in parametric comb generation. This results in a PM cavity-less comb with <9 dB power variation over 110 nm, >0 dBm power per tone, <10 kHz linewidth, and >23 dB OSNR. These characteristics make it highly desirable for application in communication and signal processing
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