1,131 research outputs found
Predictors of UK postgraduate researcher attendance behaviours and mental health-related attrition intention.
High rates of postgraduate researchers (PGRs) terminate their studies early. This attrition can have detrimental personal consequences, and results in a loss of productivity, and research and innovation for the higher education sector and society as a whole. PGRs are vulnerable to the experience of mental health problems; a factor that appears to be increasing attrition amongst students in the UK. However, investigation of the determinants of problems with PGRs' attendance and influencing intention to discontinue their studies is rare. Here, we consider the relative predictive validity of a set of putative predictors (mental health symptoms, demographic, occupational, psychological, social, and relational) of attendance behaviours (absenteeism, presenteeism, mental health-related intermission) and early attrition intention amongst UK PGRs. Depression, anxiety, and suicidality predicted attendance behaviours and greater attrition intention. Individual demographic and occupational factors predicted all outcomes. Psychological, social and relational factors had less predictive validity, although individual variables in these conceptual clusters did significantly predict some outcomes. Our results suggest that interventions to reduce high rates of mental health problems are likely to improve attendance behaviours, and reduce the extent to which PGRs intermit or consider ending their PhD studies for mental health-related reasons. Initiatives designed to improve supervisory relationships and reduce loneliness may also reduce absenteeism, intermission and attrition intention. [Abstract copyright: © The Author(s) 2022.
On the interpretation of lateral manganin gauge stress measurements in polymers
Encapsulated wire-element stress gauges enable changes in lateral stress during
shock loading to be directly monitored. However, there is substantial debate
with regards to interpretation of observed changes in stress behind the shock
front; a phenomenon attributed both to changes in material strength and shock-
dispersion within the gauge-encapsulation. Here, a pair of novel techniques
which both modify or remove the embedding medium where such stress gauges are
placed within target materials have been used to try and inform this debate. The
behavior of three polymeric materials of differing complexity was considered,
namely polystyrene, the commercially important resin transfer moulding RTM 6
resin and a commercially available fat lard. Comparison to the response of
embedded gauges has suggested a possible slight decrease in the absolute
magnitude of stress. However, changing the encapsulation has no detectable
effect on the gradient behind the shock in such polymeric systems
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Systemic Risk-Shifting in Financial Networks
Banks face different but potentially correlated risks from outside the financial system. Financial connections can share these risks, but also create the means by which shocks can propagate. We examine this tradeoff in the context of a new stylised fact
A Systematic Review of the Effects of Urban Living on Suicidality and Self-Harm in the UK and Ireland
We conducted a systematic review to answer the following: (a) Is there any evidence to support increased prevalence of suicidality and self-harm (i.e. self-harm or suicidality) in urban versus rural environments? (b) What aspects of the urban environment pose risk for suicidality and self-harm? Thirty-five studies met our criteria. Our findings reflect a mixed picture, but with a tendency for urban living to be associated with an increased risk of suicidality and self-harm over rural living, particularly for those living in deprived areas. Further research should focus on the clustering and additive effects of risk and protective factors for suicidality and self-harm in urban environments
On the dynamic tensile strength of Zirconium
Despite its fundamental nature, the process of dynamic tensile failure (spall) is poorly understood. Spall initiation via cracks, voids, etc, before subsequent coalesce, is known to be highly microstructure-dependant. In particular, the availability of slip planes and other methods of plastic deformation controls the onset (or lack thereof) of spall. While studies have been undertaken into the spall response of BCC and FCC materials, less attention has paid to the spall response of highly anisotropic HCP materials. Here the dynamic behaviour of zirconium is investigated via plate-impact experiments, with the aim of building on an ongoing in-house body of work investigating these highly complex materials. In particular, in this paper the effect of impact stress on spall in a commercially sourced Zr rod is considered, with apparent strain-rate softening highlighted
Is the content of patient’s written emotional disclosure associated with improved health outcomes for asthma patients?
Written emotional disclosure (WED) is a self-directed, writing intervention. Treatment effects post-WED vary between studies, prompting research into which variables promote the largest improvements. Thus far, research has focused on the frequency of certain linguistic properties of the writing, and subjective stress-related ratings. This study tests the feasibility of using an objective coding framework for stress typology to categorise WED extracts and explores whether any characteristics of the stress described were associated with intervention outcomes. WED extracts from a randomised controlled trial of patients with asthma were coded using an objective stress typology framework. The contents of the WED extracts were reviewed to ascertain whether the experience met the DSM-5 definition for trauma, involved abuse, and was experienced directly or vicariously. Also analysed were the degree of upheaval and upset associated with the event described, together with the time of the event, and number of events written about. Correlational analyses indicated that improvements in asthma-related outcomes were associated with writing about experiences that occurred in childhood, constituted abuse, or caused greater upheaval (all ps <. 05). We found some evidence that the treatment effects of WED may be dependent on what types of stressful experiences participants write about. The use of our objective stress coding scheme was only partially successful as it could not be applied consistently to all WED extracts. Findings require replication using a prospective experimental design
Lateral stress evolution in chromium sulfide cermets with varying excess chromium
The shock response of chromium sulfide-chromium, a cermet of potential interest as a matrix material for ballistic applications, has been investigated at two molar ratios. Using a combustion synthesis technique allowed for control of the molar ratio of the material, which was investigated under near-stoichiometric (cermet) and excess chromium (interpenetrating composite) conditions, representing chromium:sulfur molar ratios of 1.15:1 and 4:1, respectively. The compacts were investigated via the plate-impact technique, which allowed the material to be loaded under a onedimensional state of strain. Embedded manganin stress gauges were employed to monitor the temporal evolution of longitudinal and lateral components of stress in both materials. Comparison of these two components has allowed assessment of the variation of material shear strength both with impact pressure/strain-rate and time for the two molar ratio conditions. The two materials exhibited identical material strength despite variations in their excess chromium content
Gas gun ramp loading of Kel-F 81 targets using a ceramic graded areal density flyer system
Kel-F 81 (PCTFE/Polychlorotrifluoroethylene) polymer targets were subjected to ramp loadings generated by a ceramic flyer accelerated into the targets by a gas gun in the plate impact configuration. This approach used a ceramic graded areal density flyer in conjunction with a ceramic buffer plate to induce a ramp loading in the target. The flyer was comprised of a rapid prototyped alumina ceramic. The loading was observed with embedded electromagnetic particle velocity gauges (PV gauges) with the results compared with ANSYS Autodyn™ hydrocode simulations. Experimental results show that ramp loadings of varying duration and magnitude were induced into the target. These loadings can be described as shockless compressions leading to shocked states within the material. In addition, numerical simulations provided further insight into the loading approach – with good agreement found with experimental data, opening the potential to design more complex loading systems in future
The bactericidal effect of shock waves
There are a variety of theories relating to the origins of life on our home planet, some of which
discuss the possibility that life may have been spread via inter-planetary bodies. There have been a number
of investigations into the ability of life to withstand the likely conditions generated by asteroid impact (both
contained in the impactor and buried beneath the planet surface). Previously published data regarding the
ability of bacteria to survive such applied shockwaves has produced conflicting conclusions. The work
presented here used an established and published technique in combination with a single stage gas gun,
to shock and subsequently recover Escherichia coli populations suspended in a phosphate buffered saline
solution. Peak pressure across the sample region was calculated via numerical modelling. Survival data
against peak sample pressure for recovered samples is presented alongside control tests. SEM micrographs
of shocked samples are presented alongside control sets to highlight key differences between cells in each
case
On differences in the equation-of-state for a selection of seven representative mammalian tissue analogue materials
Tissue analogues employed for ballistic purposes are often monolithic in nature, e.g. ballistic gelatin and soap, etc. However, such constructs are not representative of real-world biological systems. Further, ethical considerations limit the ability to test with real-world tissues. This means that availability and understanding of accurate tissue simulants is of key importance. Here, the shock response of a wide range of ballistic simulants (ranging from dermal (protective / bulk) through to skeletal simulant materials) determined via plate-impact experiments are discussed, with a particular focus on the classification of the behaviour of differing simulants into groups that exhibit a similar response under high strain-rate loading. Resultant Hugoniot equation-of-state data (Us-up; P-v) provides appropriate feedstock materials data for future hydrocode simulations of ballistic impact events
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