251 research outputs found

    A multidimensional valuation of the human perception of construction vibration

    Get PDF
    Previous studies have shown that annoyance due to vibration does not simply depend on the magnitude of vibration exposure. However, only little is known about the important features that contribute the human perception of vibration. This paper presents a study investigating seated subjects' perception of construction induced groundborne vibration in the vertical direction with the method of multidimensional scaling. The investigation was conducted using a paired comparison subjective test. Sixteen subjects were asked about their perception of the annoyance and similarity of sixty-six pairs of vibration stimuli. Through non-metric multidimensional scaling analysis, it is presented that the perception of construction vibration activities are dependent on up to three perceptual dimensions: duration of the signal, vibration energy in the 31.5 Hz of ⅓ octave band, and the centre of mass of the frequency spectrum of the signals. A regression model was built from the relationship between the annoyance ratings and the objective descriptors revealed through the multidimensional scaling analysis. This model was found to describe 79% of the variance in the measured perceived annoyance ratings data with p-level < 0.01

    Systematic review and meta-analysis of reduction in all-cause mortality from walking and cycling and shape of dose response relationship

    Get PDF
    BACKGROUND AND OBJECTIVE: Walking and cycling have shown beneficial effects on population risk of all-cause mortality (ACM). This paper aims to review the evidence and quantify these effects, adjusted for other physical activity (PA). DATA SOURCES: We conducted a systematic review to identify relevant studies. Searches were conducted in November 2013 using the following health databases of publications: Embase (OvidSP); Medline (OvidSP); Web of Knowledge; CINAHL; SCOPUS; SPORTDiscus. We also searched reference lists of relevant texts and reviews. STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS: Eligible studies were prospective cohort design and reporting walking or cycling exposure and mortality as an outcome. Only cohorts of individuals healthy at baseline were considered eligible. STUDY APPRAISAL AND SYNTHESIS METHODS: Extracted data included study population and location, sample size, population characteristics (age and sex), follow-up in years, walking or cycling exposure, mortality outcome, and adjustment for other co-variables. We used random-effects meta-analyses to investigate the beneficial effects of regular walking and cycling. RESULTS: Walking (18 results from 14 studies) and cycling (8 results from 7 studies) were shown to reduce the risk of all-cause mortality, adjusted for other PA. For a standardised dose of 11.25 MET.hours per week (or 675 MET.minutes per week), the reduction in risk for ACM was 11% (95% CI = 4 to 17%) for walking and 10% (95% CI = 6 to 13%) for cycling. The estimates for walking are based on 280,000 participants and 2.6 million person-years and for cycling they are based on 187,000 individuals and 2.1 million person-years. The shape of the dose-response relationship was modelled through meta-analysis of pooled relative risks within three exposure intervals. The dose-response analysis showed that walking or cycling had the greatest effect on risk for ACM in the first (lowest) exposure interval. CONCLUSIONS AND IMPLICATIONS: The analysis shows that walking and cycling have population-level health benefits even after adjustment for other PA. Public health approaches would have the biggest impact if they are able to increase walking and cycling levels in the groups that have the lowest levels of these activities. REVIEW REGISTRATION: The review protocol was registered with PROSPERO (International database of prospectively registered systematic reviews in health and social care) PROSPERO 2013: CRD42013004266

    Postal survey of physicians and laboratories: Practices and perceptions of molecular oncology testing

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Molecular oncology testing (MOT) to detect genomic alterations underlying cancer holds promise for improved cancer care. Yet knowledge limitations regarding the delivery of testing services may constrain the translation of scientific advancements into effective health care.</p> <p>Methods</p> <p>We conducted a cross-sectional, self-administered, postal survey of active cancer physicians in Ontario, Canada (N = 611) likely to order MOT, and cancer laboratories (N = 99) likely to refer (i.e., referring laboratories) or conduct (i.e., testing laboratories) MOT in 2006, to assess respondents' perceptions of the importance and accessibility of MOT and their preparedness to provide it.</p> <p>Results</p> <p>54% of physicians, 63% of testing laboratories and 60% of referring laboratories responded. Most perceived MOT to be important for treatment, diagnosis or prognosis now, and in 5 years (61% – 100%). Yet only 45% of physicians, 59% of testing labs and 53% of referring labs agreed that patients in their region were receiving MOT that is indicated as a standard of care. Physicians and laboratories perceived various barriers to providing MOT, including, among 70% of physicians, a lack of clear guidelines regarding clinical indications, and among laboratories, a lack of funding (73% – 100%). Testing laboratories were confident of their ability to determine whether and which MOT was indicated (77% and 82% respectively), and perceived that key elements of formal and continuing education were helpful (75% – 100%). By contrast, minorities of physicians were confident of their ability to assess whether and which MOT was indicated (46% and 34% respectively), and while majorities considered various continuing educational resources helpful (68% – 75%), only minorities considered key elements of formal education helpful in preparing for MOT (17% – 43%).</p> <p>Conclusion</p> <p>Physicians and laboratory professionals were enthusiastic about the value of MOT for cancer care but most did not believe patients were gaining adequate access to clinically necessary testing. Further, our results suggest that many were ill equipped as individual stakeholders, or as a coordinated system of referral and interpretation, to provide MOT. These challenges should inspire educational, training and other interventions to ensure that developments in molecular oncology can result in optimal cancer care.</p

    Chimeric 14-3-3 proteins for unraveling interactions with intrinsically disordered partners

    Get PDF
    In eukaryotes, several "hub" proteins integrate signals from different interacting partners that bind through intrinsically disordered regions. The 14-3-3 protein hub, which plays wide-ranging roles in cellular processes, has been linked to numerous human disorders and is a promising target for therapeutic intervention. Partner proteins usually bind via insertion of a phosphopeptide into an amphipathic groove of 14-3-3. Structural plasticity in the groove generates promiscuity allowing accommodation of hundreds of different partners. So far, accurate structural information has been derived for only a few 14-3-3 complexes with phosphopeptide-containing proteins and a variety of complexes with short synthetic peptides. To further advance structural studies, here we propose a novel approach based on fusing 14-3-3 proteins with the target partner peptide sequences. Such chimeric proteins are easy to design, express, purify and crystallize. Peptide attachment to the C terminus of 14-3-3 via an optimal linker allows its phosphorylation by protein kinase A during bacterial co-expression and subsequent binding at the amphipathic groove. Crystal structures of 14-3-3 chimeras with three different peptides provide detailed structural information on peptide-14-3-3 interactions. This simple but powerful approach, employing chimeric proteins, can reinvigorate studies of 14-3-3/phosphoprotein assemblies, including those with challenging low-affinity partners, and may facilitate the design of novel biosensors

    Adaptive design methods in clinical trials – a review

    Get PDF
    In recent years, the use of adaptive design methods in clinical research and development based on accrued data has become very popular due to its flexibility and efficiency. Based on adaptations applied, adaptive designs can be classified into three categories: prospective, concurrent (ad hoc), and retrospective adaptive designs. An adaptive design allows modifications made to trial and/or statistical procedures of ongoing clinical trials. However, it is a concern that the actual patient population after the adaptations could deviate from the originally target patient population and consequently the overall type I error (to erroneously claim efficacy for an infective drug) rate may not be controlled. In addition, major adaptations of trial and/or statistical procedures of on-going trials may result in a totally different trial that is unable to address the scientific/medical questions the trial intends to answer. In this article, several commonly considered adaptive designs in clinical trials are reviewed. Impacts of ad hoc adaptations (protocol amendments), challenges in by design (prospective) adaptations, and obstacles of retrospective adaptations are described. Strategies for the use of adaptive design in clinical development of rare diseases are discussed. Some examples concerning the development of Velcade intended for multiple myeloma and non-Hodgkin's lymphoma are given. Practical issues that are commonly encountered when implementing adaptive design methods in clinical trials are also discussed

    Impacts of chemical gradients on microbial community structure

    Get PDF
    Succession of redox processes is sometimes assumed to define a basic microbial community structure for ecosystems with oxygen gradients. In this paradigm, aerobic respiration, denitrification, fermentation and sulfate reduction proceed in a thermodynamically determined order, known as the ‘redox tower’. Here, we investigated whether redox sorting of microbial processes explains microbial community structure at low-oxygen concentrations. We subjected a diverse microbial community sampled from a coastal marine sediment to 100 days of tidal cycling in a laboratory chemostat. Oxygen gradients (both in space and time) led to the assembly of a microbial community dominated by populations that each performed aerobic and anaerobic metabolism in parallel. This was shown by metagenomics, transcriptomics, proteomics and stable isotope incubations. Effective oxygen consumption combined with the formation of microaggregates sustained the activity of oxygen-sensitive anaerobic enzymes, leading to braiding of unsorted redox processes, within and between populations. Analyses of available metagenomic data sets indicated that the same ecological strategies might also be successful in some natural ecosystems

    Agricultural policies exacerbate honeybee pollination service supply-demand mismatches across Europe

    Get PDF
    Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue

    Dose-response associations between cycling activity and risk of hypertension in regular cyclists: The UK Cycling for Health Study

    Get PDF
    Most population studies on physical activity and health have involved largely inactive men and women, thus making it difficult to infer if health benefits occur at exercise levels above the current minimum guidelines. The aim was to examine associations between cycling volume and classical cardiovascular risk markers, including hypertension and hypercholesterolemia, in a population sample of habitual cyclists. A nationwide sample comprising 6,949 men and women (aged 47.6 yrs on average) completed questions about their cycling levels, demographics and health. Nearly the entire sample (96.3%) achieved the current minimum physical activity recommendation through cycling alone. There was a dose-response association between cycling volume and risk of diagnosed hypertension (p-trend =0.001), with odds ratios of 0.98 (95% CI, 0.80 – 1.21), 0.86 (0.70, 1.06), 0.67 (95% CI, 0.53 – 0.83) across categories of 23 – 40, 40 – 61, and >61 MET-hr/wk compared with <23 MET-hr/wk. These associations persisted in models adjusted for age, sex, smoking, alcohol, BMI, and other moderate to vigorous physical activities. We also observed inverse associations between cycling volume and other risk factors including BMI and hypercholesterolemia. In summary, results from a population sample of cyclists suggest that additional cardiovascular health benefits can be achieved beyond the current minimum physical activity recommendation

    Inhaled corticosteroids and long-acting beta-agonists in adult asthma: a winning combination in all?

    Get PDF
    In the recent years, considerable insight has been gained in to the optimal management of adult asthma. Most adult patients with asthma have mild intermittent and persistent disease, and it is acknowledged that many patients do not reach full control of all symptoms and signs of asthma. Those with mild persistent asthma are usually not well controlled without inhaled corticosteroids (ICS). Studies have provided firm evidence that these patients can be well controlled when receiving ICS, especially when disease is of recent onset. This treatment should be given on a daily basis at a low dose and when providing a good response should be maintained to prevent severe exacerbations and disease deterioration. Intermittent ICS treatment at the time of an exacerbation has also been suggested as a strategy for mild persistent asthma, but it is less effective than low-dose regular treatment for most outcomes. Adding a long-acting beta-agonist (LABA) to ICS appears to be unnecessary in most of these patients for optimising control of their asthma. Patients with moderate persistent asthma can be regarded as those who are not ideally controlled on low-dose ICS alone. The combination of an ICS and LABA is preferred in these patients, irrespective of the brand of medicine, and this combination is better than doubling or even quadrupling the dose of ICS to achieve better asthma control and reduce exacerbation risks. An ICS/LABA combination in a single inhaler represents a safe, effective and convenient treatment option for the management of patients with asthma unstable on inhaled steroids alone. Ideally, once asthma is under full control, the dose of inhaled steroids should be reduced, which is possible in many patients. The duration of treatment before initiating this dose reduction has, however, not been fully established. One of the combinations available to treat asthma (budesonide and formoterol) has also been assessed as both maintenance and rescue therapy with a further reduction in the risk for a severe exacerbation. Clinical effectiveness in the real world now has to be established, since this approach likely improves compliance with regular maintenance therapy
    corecore