1,253 research outputs found
Adding value and meaning to coheating tests
Purpose: The coheating test is the standard method of measuring the heat loss coefficient of a building, but to be useful the test requires careful and thoughtful execution. Testing should take place in the context of additional investigations in order to achieve a good understanding of the building and a qualitative and (if possible) quantitative understanding of the reasons for any performance shortfall. The paper aims to discuss these issues. Design/methodology/approach: Leeds Metropolitan University has more than 20 years of experience in coheating testing. This experience is drawn upon to discuss practical factors which can affect the outcome, together with supporting tests and investigations which are often necessary in order to fully understand the results. Findings: If testing is approached using coheating as part of a suite of investigations, a much deeper understanding of the test building results. In some cases it is possible to identify and quantify the contributions of different factors which result in an overall performance shortfall. Practical implications: Although it is not practicable to use a fully investigative approach for large scale routine quality assurance, it is extremely useful for purposes such as validating other testing procedures, in-depth study of prototypes or detailed investigations where problems are known to exist. Social implications: Successful building performance testing is a vital tool to achieve energy saving targets. Originality/value: The approach discussed clarifies some of the technical pitfalls which may be encountered in the execution of coheating tests and points to ways in which the maximum value can be extracted from the test period, leading to a meaningful analysis of the building's overall thermal performance
Underrecording of osteoarthritis in United Kingdom primary care electronic health record data
Purpose: Primary care electronic health records are increasingly used to estimate the occurrence of osteoarthritis (OA). We aimed to estimate the extent and trend over time of underrecording of severe OA patients in UK primary care electronic health records using first primary total hip and knee replacements (THR/TKR) – >90% of which are performed for OA – as the reference population.
Patients and methods: We identified patients with a first primary THR or TKR recorded in the UK Clinical Practice Research Datalink between 2000 and 2015. We then searched for a diagnostic/problem code for OA up to 10 years prior to THR/TKR using 3 definitions: “diagnosed OA (joint-specific),” “diagnosed OA (any joint),” “clinical OA” (diagnosed OA or relevant peripheral joint pain symptom code).
Results: Among 34,299 THR patients identified, 28.1%, 53.4%, and 74.4% had a prior record of diagnosed OA (hip), diagnosed OA (any), and clinical OA, respectively. Among 47,588 TKR patients, the corresponding figures were, 25.5% (diagnosed OA [knee]), 43.7%, and 74.8%. In
the UK Clinical Practice Research Datalink, the proportion of patients with prior recorded OA decreased between 2000 and 2015.
Conclusion: An increasing trend of underrecording of OA or joint pain among patients with THR or TKR (severe OA patients) between 2000 and 2015 was identified. An underestimate health care demand could be derived based on consultation incidence and prevalence of OA from electronic health record data that relies on osteoarthritis diagnostic codes. Further studies are warranted to investigate the validity of OA or joint pain recorded in primary care settings, which might be used to correct the consultation incidence and prevalence of OA
A solution to Darwin’s dilemma of 1859 : Exceptional preservation in Salter’s material from the late Ediacaran Longmyndian Supergroup, England
Peer reviewedPostprin
Party Wall Cavity Barrier Effective Edge Seal Testing for ARC Building Solutions Ltd
ARC Building Solutions Ltd manufacture, market and distribute a range of party wall cavity barriers. Part L of the Building Regulations (HM Government, 2013) stipulates that when cavity barriers are used for edge sealing purposes, then the seal must be effective at restricting air flow between the party wall cavity and the external wall cavity or external environment (Figure 1). The Building Control Alliance (2011) describes how an edge seal is to be judged as being effective in a qualitative manner. However, there is currently no standard test for quantitatively demonstrating the effectiveness of edge sealing using a cavity barrier product. ARC Building Solutions Ltd wished to quantify the effectiveness of the edge seal that could be achieved using the Company’s products under test conditions. This information could prove useful when engaging designers, building control bodies and warranty providers. As there is currently no quantitative benchmark for what is deemed to be an effective edge seal this project aimed to compare the performance of a recognised ‘current practice’ solution against ARC Building Solutions Ltd.’s T-Barrier, and as far as possible compare these to an accepted effective edge seal for a number of different party wall and external wall cavity widths. In addition to this comparative testing, this project may also assist in the development and application of a standardised ‘Edge Seal Test’ for which there is understood to be no current standard or specific precedent. Whilst the test rig may not be fully representative of the actual construction of a party wall/external wall junction in situ, it is hoped that the results may provide insight as to how the performance of these products may compare in real building situations
Trends in gabapentinoid prescribing in patients with osteoarthritis: a United Kingdom national cohort study in primary care
Summary Objective
To investigate trends in gabapentinoid prescribing in patients with osteoarthritis (OA).
Methods
Patients aged 40 years and over with a new OA diagnosis recorded between 1995 and 2015 were identified in the Clinical Practice Research Datalink and followed to first prescription of gabapentin or pregabalin, or other censoring event. We estimated the crude and age-standardised annual incidence rates of gabapentinoid prescribing, stratified by patient age, sex, geographical region, and time since OA diagnosis, and the proportion of prescriptions attributable to OA, or to other conditions representing licensed and unlicensed indications for a gabapentinoid prescription.
Results
Of 383,680 newly diagnosed OA cases, 35,031 were prescribed at least one gabapentinoid. Irrespective of indication, the annual age-standardised incidence rate of first gabapentinoid prescriptions rose from 1.6 (95% CI: 1.3, 2.0) per 1,000 person-years in 2000, to 27.6 (26.7, 28.4) in 2015, a trend seen across all ages and not explained by length of follow-up. Rates were higher among women, younger patients, and in Northern Ireland, Scotland and the North of England. Approximately 9% of first prescriptions could be attributed to OA, a further 13% to comorbid licensed or unlicensed indications.
Conclusion
Gabapentinoid prescribing in patients with OA increased dramatically between 1995 and 2015. In most cases, diagnostic codes for licensed or unlicensed indications were absent. Gabapentinoid prescribing may be attributable to OA in a significant proportion but evidence for their effectiveness in OA is lacking. Further research to investigate clinical decision making around prescribing these expensive and potentially harmful medicines is recommended
Rotation and activity of pre-main-sequence stars
We present a study of rotation (vsini) and chromospheric activity (Halpha EW)
based on an extensive set of high-resolution optical spectra obtained with MIKE
on the 6.5m Magellan Clay telescope. Our targets are 74 F-M dwarfs in the young
stellar associations Eta Cha, TW Hydrae, Beta Pic, and Tuc-Hor, spanning ages
from 6 to 30 Myr. While the Halpha EW for most F and G stars are consistent
with pure photospheric absorption, most K and M stars show chromospheric
emission. By comparing Halpha EW in our sample to results in the literature, we
see a clear evolutionary sequence: Chromospheric activity declines steadily
from the T Tauri phase to the main sequence. Using activity as an age
indicator, we find a plausible age range for the Tuc-Hor association of 10-40
Myr. Between 5 and 30 Myr, we do not see evidence for rotational braking in the
total sample, thus angular momentum is conserved, in contrast to younger stars.
This difference indicates a change in the rotational regulation at 5-10 Myr,
possibly because disk braking cannot operate longer than typical disk
lifetimes, allowing the objects to spin up. The rotation-activity relation is
flat in our sample; in contrast to main-sequence stars, there is no linear
correlation for slow rotators. We argue that this is because young stars
generate their magnetic fields in a fundamentally different way from
main-sequence stars, and not just the result of a saturated solar-type dynamo.
By comparing our rotational velocities with published rotation periods for a
subset of stars, we determine ages of 13 (7-20) Myr and 9 (7-17} Myr for the
Eta Cha and TWA associations, respectively, consistent with previous estimates.
Thus we conclude that stellar radii from evolutionary models by Baraffe et al.
(1998) are in agreement with the observed radii within +-15%. (abridged)Comment: 40 pages, 8 figures, ApJ, in pres
Are you a researcher as well as a medical illustrator?
When we list the areas of practice for medical illustrators we always include research, but how involved in research are we? The aim of this activity is to encourage your professional development not just as a medical illustrator but your involvement with research whether that is undertaking your own research, undertaking evidence based practice (1) , working as part of a research team, advising researchers on the value of medical illustration or supporting a student undertaking a research project for their degree or post-graduate qualification
Investigating the Dynamics between Price Volatility, Price Discovery, and Criminality in Cryptocurrency Markets
This paper identifies several stylised facts relating to the volatility and price discovery process
from eight cryptocurrencies utilising an empirical analysis of intra-day trading data to uncover four
main results. First, cryptocurrencies exhibit weekend-volatility effects while intra-day volatility
is found to be influenced by international trading times, periods of substantial volatility in the
markets for oil, and GBP/USD and cybercrime events. Secondly, a thorough investigation of recent
cybercriminality identifies that cryptocurrency hacks are found to increase both the volatility of
the currency hacked and the correlations across the hacked currency and other cryptocurrencies.
Thirdly, hacks significantly reduce price discovery sourced within the hacked currency relative to
other cryptocurrencies. Finally, there are abnormal returns associated with the hacks observed
in the hours prior to the actual hacking event, which reverts to zero at the time of the public
announcement of the hack
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