To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Gig work and other flexible labour practices have been subject to unprecedented levels of attention recently. While this topic has attracted significant interest from employment lawyers, it remains relatively underexplored from other pertinent legal and inter-disciplinary angles. This paper will adopt an alternative perspective on flexible work inspired by Coase's theory of the firm. Focusing on the implications of flexible work for the relative allocation of control, risk and reward within the firm, it will highlight how both task-oriented (gig) and on-demand (casual) work practices typically entail workers assuming most of the positional disadvantages associated with orthodox employment and self-employment, while enjoying none or few of the corresponding advantages. Using a hypothetical contract analysis, it will highlight the structural similarity between flexible work and unsecured financial investments in business firms by reference to key strands of institutional economics and law and finance literature. On this basis, it will enquire as to optimal forms of compensation that rational flexible workers can (counter-factually) be regarded as bargaining for in the absence of impediments to efficient contracting, and as the price for trading off their traditional employment guarantees.
The purpose of this work was to develop accurate calibration standards which were fully characterized in terms of uniformity and concentration using fundamental measuring methods. Three similar sets of vacuum deposits were commercially made, each set containing the single deposits CuS, KCl, CaF2, Cr, Fe, Cu, RbNO3, SrF2, MoO3 , BaF2, and Pb. Thickness variations in each deposit were measured with PIXEA (proton induced x-ray excitation analysis) measurements taken at 6 to 8 positions along the deposit diameters. Relative elemental concentrations on corresponding deposits from each set were measured using multiple XRF intercomparisons. One set of deposits was destructively analyzed at the National Bureau of Standards with isotope dilution thermal ionization mass spectrometry (IDMS) in order to calibrate the remaining sets of vacuum deposits. The calibrated deposits were compared with standards from two commercial sources. For seven elements heavier than chlorine there was an average deviation of 13.5% between the calibrated deposits and the commercial standards. Disagreements as large as 15% were observed between standards from the two commercial suppliers.
A new method for the collection and analysis of high temperature Guinier x-ray data has been devised at The Dow Chemical Co. This technique can be used to monitor various types of structural transformation and thermal expansions up to 900°C. The thermal expansions of α-Al2O3 and two TiO2 structures, anatase and rutile, have been characterized for their use as high temperature internal standards.
There is an urgent need to find effective methods of supporting individuals to make dietary behaviour changes. Peer-supported interventions (PSI) have been suggested as a cost-effective strategy to support chronic disease self-management. However, the effect of PSI on dietary behaviour is unclear. The present systematic review aimed to assess the effectiveness of PSI for encouraging dietary behaviour change in adults and to consider intervention characteristics linked with effectiveness.
Electronic databases were searched until June 2018 for randomised controlled trials assessing the effectiveness of PSI compared with an alternative intervention and/or control on a dietary related outcome in adults. Following title and abstract screening, two reviewers independently screened full texts and data were extracted by one reviewer and independently checked by another. Results were synthesised narratively.
Randomised controlled trials.
The fifty-four included studies varied in participants, intervention details and results. More PSI reported a positive or mixed effect on diet than no effect. Most interventions used a group model and were lay-led by peer supporters. Several studies did not report intervention intensity, fidelity and peer training and support in detail. Studies reporting positive effects employed more behaviour change techniques (BCT) than studies reporting no effect; however, heterogeneity between studies was considerable.
As evidence was mixed, further interventions need to assess the effect of PSI on dietary behaviour, describe intervention content (theoretical basis, BCT, intensity and peer training/support) and include a detailed process evaluation.
Metabolic disorders from poor foregut digestion of starch-based concentrate feeds are one of the most serious challenges that face today’s horse owners. Although there are many different cereal and legume-based concentrates used to formulate compound horse feeds in Europe relatively little is known about their in vivo foregut digestibility. While Meyer et al (1993) has examined the effects of processing on digestibility, there is no published data comparing the in vivo foregut digestibility of a wide range of concentrates. Therefore this study sought to determine the digestibility of 20 different starch rich feeds in the foregut of horses using the mobile bag technique.
Four mature geldings (BW ranging from 395 to 478 kg) fitted with caecal and colonic cannulae, were maintained in individual stalls, where water was available ad libitum and fed a diet of pellets and straw. The pelleted feed, fed at 0.8% BW/d, contained 14% fibre, 13% crude protein, 3.2% fat and 8.7% ash. This feed was equally divided and offered at 8am and 5pm.
Highly variable climates induce large variability in the supply of forage for livestock and so farmers must manage their livestock systems to reduce the risk of feed gaps (i.e. periods when livestock feed demand exceeds forage supply). However, mixed crop-livestock farmers can utilise a range of feed sources on their farms to help mitigate these risks. This paper reports on the development and application of a simple whole-farm feed-energy balance calculator which is used to evaluate the frequency and magnitude of feed gaps. The calculator matches long-term simulations of variation in forage and metabolisable energy supply from diverse sources against energy demand for different livestock enterprises. Scenarios of increasing the diversity of forage sources in livestock systems is investigated for six locations selected to span Australia’s crop-livestock zone. We found that systems relying on only one feed source were prone to higher risk of feed gaps, and hence, would often have to reduce stocking rates to mitigate these risks or use supplementary feed. At all sites, by adding more feed sources to the farm feedbase the continuity of supply of both fresh and carry-over forage was improved, reducing the frequency and magnitude of feed deficits. However, there were diminishing returns from making the feedbase more complex, with combinations of two to three feed sources typically achieving the maximum benefits in terms of reducing the risk of feed gaps. Higher stocking rates could be maintained while limiting risk when combinations of other feed sources were introduced into the feedbase. For the same level of risk, a feedbase relying on a diversity of forage sources could support stocking rates 1.4 to 3 times higher than if they were using a single pasture source. This suggests that there is significant capacity to mitigate both risk of feed gaps at the same time as increasing ‘safe’ stocking rates through better integration of feed sources on mixed crop-livestock farms across diverse regions and climates.
Identifying genetic relationships between complex traits in emerging adulthood can provide useful etiological insights into risk for psychopathology. College-age individuals are under-represented in genomic analyses thus far, and the majority of work has focused on the clinical disorder or cognitive abilities rather than normal-range behavioral outcomes.
This study examined a sample of emerging adults 18–22 years of age (N = 5947) to construct an atlas of polygenic risk for 33 traits predicting relevant phenotypic outcomes. Twenty-eight hypotheses were tested based on the previous literature on samples of European ancestry, and the availability of rich assessment data allowed for polygenic predictions across 55 psychological and medical phenotypes.
Polygenic risk for schizophrenia (SZ) in emerging adults predicted anxiety, depression, nicotine use, trauma, and family history of psychological disorders. Polygenic risk for neuroticism predicted anxiety, depression, phobia, panic, neuroticism, and was correlated with polygenic risk for cardiovascular disease.
These results demonstrate the extensive impact of genetic risk for SZ, neuroticism, and major depression on a range of health outcomes in early adulthood. Minimal cross-ancestry replication of these phenomic patterns of polygenic influence underscores the need for more genome-wide association studies of non-European populations.
Estimates of digesta passage through specific segments of the alimentary tract are a vital component of modelling approaches which attempt to quantitatively partition digestive processes in equines. This study reports results from three studies where digesta passage of Chromium (Cr) mordanted feeds was determined in the caecum of ponies.
Caecal outflow rates were determined during three in vivo apparent digestibility studies conducted using three caecally-fistulated ponies as described by Moore-Colyer et al, (1999) for studies 1 and 2; and McLean et al, (1999) for study 3. Pony basal diets consisted of unmolassed sugar beet pulp (USBP), hay cubes (HC) or a 2:1 mix of oat hulls:naked oats (OHNO) in study 1; a 1:1 mix of USBP:HC (USHC) in study 2 and either 100% HC or one of 3 diets consisting of a 1:1 HC:barley mix where the barley was either rolled (RBHC), micronised (MBHC) or extruded (EBHC) in study 3.
Ice cores from small ice caps provide valuable climatic information, additional to that of Greenland and Antarctica. However, their integrity is usually compromised by summer meltwater percolation. To determine to what extent this can affect such ice cores, we performed high-resolution tritium measurements on samples from two ice cores from Spitsbergen covering the period AD1955–75. The very sharp and distinct peaks in the tritium precipitation record are subject to several post-depositional processes. We developed a model that uses the precipitation record as input and incorporates the three most important processes (radioactive decay, isotope diffusion and meltwater percolation). Results are compared with measured tritium and density profiles. Both ice-core records contain sharp bomb peaks in the pre-1963 period. It is shown that these peaks would be much smoother in the absence of melt. In this case the main effect of melt and the refreezing of percolation water is the formation of ice layers that form barriers for firn diffusion; thus melt paradoxically results in better preservation of the annual isotope signals. Conversely, for the period after 1963 the main effect of melt is a stronger smoothing of the tritium profiles.
Snow pits sampled during two consecutive years (2001, 2002) at the summit of Lomonosovfonna ice cap in central Spitsbergen, Svalbard, showed that ion concentrations were spatially homogeneous. The snowpack on Lomonosovfonna shows no evidence of aerosol deposition from Arctic haze, in contrast to Holtedahlfonna (a glacier at a similar altitude in northern Spitsbergen) where there is a clear signature. In common with many other ice caps in the Arctic, Lomonosovfonna experiences periodic melting, and the deepest of the snow pits contained a record of one exceptionally warm (2001) and one long summer (2000). The most easily eluted species are nitrate and the divalent ions. Very low ion concentrations and high values of a melt indicator log([Na+]/[Mg2+]) were a result of either deep percolation or runoff of ions during melting. Comparing the snow-pit record with the ion record of more than 800 years from an ice core drilled on Lomonosovfonna in 1997 reveals some layers with similar composition to those that suffered significant melting in the snowpack: a few years in the 20th century and around AD 1750, and all of the core from before AD 1200 show unusually heavy melting.
We performed a spatial-temporal analysis to assess household risk factors for Ebola virus disease (Ebola) in a remote, severely-affected village. We defined a household as a family's shared living space and a case-household as a household with at least one resident who became a suspect, probable, or confirmed Ebola case from 1 August 2014 to 10 October 2014. We used Geographic Information System (GIS) software to calculate inter-household distances, performed space-time cluster analyses, and developed Generalized Estimating Equations (GEE). Village X consisted of 64 households; 42% of households became case-households over the observation period. Two significant space-time clusters occurred among households in the village; temporal effects outweighed spatial effects. GEE demonstrated that the odds of becoming a case-household increased by 4·0% for each additional person per household (P < 0·02) and 2·6% per day (P < 0·07). An increasing number of persons per household, and to a lesser extent, the passage of time after onset of the outbreak were risk factors for household Ebola acquisition, emphasizing the importance of prompt public health interventions that prioritize the most populated households. Using GIS with GEE can reveal complex spatial-temporal risk factors, which can inform prioritization of response activities in future outbreaks.
Recovery is a key goal for individuals, and services’ recovery orientation can facilitate this process. The independent mental health sector is increasingly important in Ireland, particularly in counselling and suicide prevention. We aimed to evaluate Pieta House as a recovery-oriented service through clients’ self-rated recovery; and clients’ and therapists’ evaluation of the service.
Clients completing therapy over a 3-month period were invited to complete the Recovery Assessment Scale (RAS) and the Recovery Self Assessment-Revised (RSA-R). Therapists completed the RSA-R staff version.
Response rate was 36.7% for clients (n=88), 98% for therapists (n=49). Personal recovery was endorsed by 73.8% of clients, with highest agreement for factors ‘Willingness to Ask for Help’ (84.5%), and ‘Reliance on Others’ (82.1%). A smaller number agreed with factors ‘Personal Confidence and Hope’ (61.3%) and ‘No Domination by Symptoms’ (66.6%). Clients’ and therapists’ evaluation of the service showed high levels of agreement with factors of ‘Choice’ (90.9% clients, 100% therapists); ‘Life Goals’ (84.1% clients, 98% therapists) and ‘Individually Tailored Services’ (80.6% clients, 79.6% therapists). Client involvement in service management had the lowest level of agreement (36.4% clients, 30.6% therapists). Clients’ self-rated recovery correlated with their rating of the service (correlation value 0.993, p=0.01).
Clients’ self-rated recovery and the recovery orientation of Pieta House were rated highly, with areas for improvement in service user involvement, peer support and advocacy. The correlation of personal recovery and recovery orientation of the service may merit further study.
Future projections of the evolution of ice caps as well as ice sheets and consequent sea-level rise face several methodological challenges, one being the two-way coupling between ice flow and mass-balance models. Full two-way coupling between mass-balance models – or, in a wider scope, climate models – and ice flow models has rarely been implemented due to substantial technical challenges. Here we examine some coupling effects for the Vestfonna ice cap, Nordaustlandet, Svalbard, by analysing the impacts of different coupling intervals on mass-balance and sea-level rise projections. By comparing coupled to traditionally deployed uncoupled strategies, we prove that neglecting the topographic feedbacks in the coupling leads to underestimations of 10–20% in sea-level rise projections on century timescales in our model. As imposed climate scenarios increasingly change mass balance, uncertainties in the unknown evolution of the fast-flowing outlet glaciers decrease in importance due to their deceleration and reduced mass flux as they thin and retreat from the coast. Parameterizing mass-balance adjustment for changes in topography using lapse rates as a cost-effective alternative to full coupling produces satisfactory results for modest climate change scenarios. We introduce a method to estimate the error of the presented partially coupled model with respect to as yet unperformed two-way fully coupled results.
Introduction: Redirecting low acuity patients from emergency departments to primary care walk-in clinics has been identified as a priority by many health authorities. Promoting family physicians for the management of ambulatory patients with urgent health concerns reflects the assumption that primary care facilities can offer high-quality and more affordable ambulatory emergency care. However, no performance assessment framework has been developed for ambulatory emergency care and consequently, quality of care provided in these alternate settings has never been formally compared. Primary objective: To identify structure, process and outcome indicators for ambulatory emergency care. Methods: We will identify and develop quality indicators (QIs) for ambulatory emergency care using a RAND/UCLA Appropriateness Method (RAM) composed of three different steps. First, we will perform a scoping literature review to inventory 1) all previously recommended QIs assessing care provided to ambulatory emergency patients in the ED or the primary care settings; 2) all conditions evaluated with the retrieved QIs; and 3) all outcomes measured by the same QIs. Second, a steering committee composed of the research team and of international experts in performance assessment in emergency and primary care will be presented with the lists of QI-related conditions and outcomes. They will be asked to identify potential outcome indicators for ambulatory emergency care by generating any relevant combinations of one condition and one outcome (e.g. acute asthma exacerbation/re-consultation). Committee members will be given the latitude to use and pair any conditions or outcomes not included in the lists as long as they think the resulting indicators are compatible with the study objectives. Using a structured nominal group approach, they will combine their suggestions and refine the list of potential QIs. This list of potential outcome indicators composed of pairs “condition/outcome” will be merged with the list of already published QIs identified during the literature review. Third, as per the RAM standards, we will assemble an international multidisciplinary panel (n=20) of patients, emergency and primary care providers, researchers and decision makers, after recommendations from international emergency and primary care associations, and from the Canadian Strategy for Patient-Oriented Research (SPOR) Support Units. Through iterative rounds of ratings using both web-based survey tools and videoconferencing, panelists will independently assess all candidate QIs. They will be asked to rate on a nine-level scale to what extent each QI is a relevant and useful measure of ambulatory emergency care quality. From one round to the next, QIs with a median panelist rating score of one to three will be excluded. Those with a median score of seven or more will be automatically included in the final list. QIs with median score of four to six will be retained for future deliberations among the panelists. Rounds of ratings will be conducted until all QIs are classified. Impact: The QIs identified will be used to develop a performance assessment framework for ambulatory emergency care. This will represent an essential step toward testing the assumption that EDs and primary care walk-in clinics provide equivalent care quality to low acuity patients.
We use the TGAS proper motions and parallaxes as well as published and new radial velocities to study the dynamics of nearby moving groups. In particular we try to determine their age using backtracing of the individual members to a common origin. We find that the current data, probably the radial velocities, do not allow to reach a successful conclusion.
We present a model for ice formation in a thin, viscous liquid film driven by a Blasius boundary layer after heating is switched off along part of the flat plate. The flow is assumed to initially be in the Nelson et al. (J. Fluid Mech., vol. 284, 1995, pp. 159–169) steady-state configuration with a constant flux of liquid supplied at the tip of the plate, so that the film thickness grows like
in distance along the plate. Plate cooling is applied downstream of a point,
-distance from the tip of the plate, where
is much larger than the film thickness. The cooling is assumed to be slow enough that the flow is quasi-steady. We present a thorough asymptotic derivation of the governing equations from the incompressible Navier–Stokes equations in each fluid and the corresponding Stefan problem for ice growth. The problem breaks down into two temporal regimes corresponding to the relative size of the temperature difference across the ice, which are analysed in detail asymptotically and numerically. In each regime, two distinct spatial regions arise, an outer region of the length scale of the plate, and an inner region close to
in which the film and air are driven over the growing ice layer. Moreover, in the early time regime, there is an additional intermediate region in which the air–water interface propagates a slope discontinuity downstream due to the sudden onset of the ice at the switch-off point. For each regime, we present ice profiles and growth rates, and show that for large times, the film is predicted to rupture in the outer region when the slope discontinuity becomes sufficiently enhanced.