1,088 research outputs found
Eruptive shearing of tube pumice: pure and simple
Abstract. Understanding the physico-chemical conditions extant and mechanisms operative during explosive volcanism is essential for reliable forecasting and mitigation of volcanic events. Rhyolitic pumices reflect highly vesiculated magma whose bubbles can serve as a strain indicator for inferring the state of stress operative immediately prior to eruptive fragmentation. Obtaining the full kinematic picture reflected in bubble population geometry has been extremely difficult, involving dissection of a small number of delicate samples. The advent of reliable high-resolution tomography has changed this situation radically. Here we demonstrate via the use of tomography how a statistically powerful picture of the shapes and connectivity of thousands of individual bubbles within a single sample of tube pumice emerges. The strain record of tube pumice is dominated by simple shear (not pure shear) in the late deformational history of vesicular magma before eruption. This constraint in turn implies that magma ascent is conditioned by a velocity gradient at the point of origin of tube pumice. Magma ascent accompanied by simple shear should enhance high eruption rates inferred independently for these highly viscous systems. </jats:p
One-dimensional pattern of Au nanodots by ion-beam-sputtering: formation and mechanism
Highly ordered one-dimensional arrays of nanodots, or nanobeads, are
fabricated by forming nanoripples and nanodots in sequence, entirely by
ion-beamsputtering (IBS) of Au(001). This demonstrates the capability of IBS
for the fabrication of sophisticated nanostructures via hierarchical
self-assembly. The intricate nanobead pattern ideally serves to identify the
governing mechanisms for the pattern formation: Non-linear effects, especially
local redeposition and surface-confined transport, are essential both for the
formation and the preservation of the pattern order
The role of photograph aesthetics on online review sites:Effects of management- versus traveler-generated photos on tourists’ decision-making
Tourists searching for information about destinations on online review sites areconcurrently exposed to two different photograph aesthetics, professional (produced by destination managers) and amateur (generated by travelers). While the former is glossy and sharp, the latter is often grainy and overexposed. Although aesthetics are important factors in tourist decision-making, the effects of the exposure to both types of photo aesthetics remain largely unexamined. This research investigates how both types of aesthetics, either singularly or in combination, affect a destination’s visual appeal and tourists’ booking intentionsthrough four controlled experiments (N = 1282). Our results show that despite the ‘messy’ beauty in amateur aesthetics, photos with professional aesthetics make a depicted destinationappear more visually appealing, ultimately driving booking intentions. However, the negative effects of amateur aesthetics are mitigated when (i) viewed by risk-averse tourists, (ii) presented alongside positive reviews, and (iii) accompanied by a greater number of professional photos
Who is dominant? Occupational Health and Safety management in Chinese shipping
This paper investigates the implementation of the International Safety Management
(ISM) Code in the Chinese chemical shipping industry. In particular, it examines the
tension between management focus on speedy production and seafarers’ participation
in safety related decision making and analyses how this tension is managed. It shows
that while on paper companies have policies stating safety commitment in compliance
with the ISM Code, in practice shore management tends to prioritise efficient
production. When Occupational Health and Safety (OHS) and ship’s sailing schedules
are in conflict, managers implicitly request shipmasters to prioritise the ‘core interest’
of the company. Although the ISM Code endows shipmasters with overriding
authorities in relation to shipboard safety management, they tend to read between the
lines and tacitly follow managers’ intentions. The study suggests that if the ISM
implementation makes a difference, it is the practice that managers become more
subtle in giving orders to exert their dominance. The study further reveals that the
management’s practice is not only irresponsive to seafarers’ safety concerns but also
makes rather limited contributions to promote OHS Management
Impact on diarrhoeal illness of a community educational intervention to improve drinking water quality in rural communities in Puerto Rico
<p>Abstract</p> <p>Background</p> <p>Waterborne disease is a major risk for small water supplies in rural settings. This study was done to assess the impact of an educational intervention designed to improve water quality and estimate the contribution of water to the incidence of diarrhoeal disease in poor rural communities in Puerto Rico a two-part study was undertaken.</p> <p>Methods</p> <p>An educational intervention was delivered to communities relying on community water supplies. This intervention consisted of student operators and administrators supervising and assisting community members who voluntarily "operate" these systems. These voluntary operators had no previous training and were principally concerned with seeing that some water was delivered. The quality of that water was not something they either understood or addressed. The impact of this intervention was measured through water sampling for standard bacteriological indicators and a frank pathogen. In addition, face-to-face epidemiological studies designed to determine the base-line occurrence of diarrhoeal disease in the communities were conducted. Some 15 months after the intervention a further epidemiological study was conducted in both the intervention communities and in control communities that had not received any intervention.</p> <p>Results</p> <p>Diarrhoeal illness rates over a four week period prior to the intervention were 3.5%. <it>Salmonella </it>was isolated from all of 5 distributed samples prior to intervention and from only 2 of 12 samples after the intervention. In the 15 months follow-up study, illness rates were lower in the intervention compared to control communities (2.5% <it>vs </it>3.6%%) (RR = 0.70, 95%CI 0.43, 1.15), though this was not statistically significant. However, in the final Poisson regression model living in an intervention system (RR = 0.318; 95%CI 0.137 - 0.739) and owning a dog (RR = 0.597, 95%CI 0.145 - 0.962) was negatively associated with illness. Whilst size of system (RR = 1.006, 95%CI 1.001 - 1.010) and reporting problems with sewage system (RR = 2.973, 95%CI 1.539 - 5.744) were positively associated with illness.</p> <p>Conclusions</p> <p>Educational interventions directed both at identified individuals and the community in general in small communities with poor water quality is a way of giving communities the skills and knowledge to manage their own drinking water quality. This may also have important and sustainable health benefits, though further research preferably using a randomised control trial design is needed.</p
The leadership component of Kelly’s Mobilisation Theory : contribution, tensions, limitations and further development
This reassessment of Kelly’s analysis of the relationship of activist leadership to collective action within the overall jigsaw of mobilisation theory draws on social movement literature, studies by industrial relations scholars utilising aspects of Kelly’s approach – including this author’s own work – and related research on union leadership within collective mobilisation. In the process, it identifies and celebrates how Kelly’s work, whilst contributing a distinct and substantive actor-related approach, recognised that leadership is one ingredient amongst other factors, including important structural opportunities and constraints. It considers three potential ambiguities/tensions within Kelly’s conceptualisation of leadership related to the social construction of workers’ interests, spontaneity of workers’ action and the ‘leader/follower’ interplay. The review also identifies two important limitations, related to the union member/bureaucracy dynamic and the role of left-wing political leadership, and concludes by signalling different forms of leadership relationships on which further refinement and development would be fruitful
International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe
In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible
Inhomogeneous Point-Processes to Instantaneously Assess Affective Haptic Perception through Heartbeat Dynamics Information
This study proposes the application of a comprehensive signal processing framework, based on inhomogeneous point-process models of heartbeat dynamics, to instantaneously assess affective haptic perception using electrocardiogram-derived information exclusively. The framework relies on inverse-Gaussian point-processes with Laguerre expansion of the nonlinear Wiener-Volterra kernels, accounting for the long-term information given by the past heartbeat events. Up to cubic-order nonlinearities allow for an instantaneous estimation of the dynamic spectrum and bispectrum of the considered cardiovascular dynamics, as well as for instantaneous measures of complexity, through Lyapunov exponents and entropy. Short-term caress-like stimuli were administered for 4.3?25?seconds on the forearms of 32 healthy volunteers (16 females) through a wearable haptic device, by selectively superimposing two levels of force, 2?N and 6?N, and two levels of velocity, 9.4?mm/s and 65?mm/s. Results demonstrated that our instantaneous linear and nonlinear features were able to finely characterize the affective haptic perception, with a recognition accuracy of 69.79% along the force dimension, and 81.25% along the velocity dimension
Thoracic CT findings of novel influenza A (H1N1) infection in immunocompromised patients
The goal of this study is to describe the spectrum of initial and follow-up CT findings of novel influenza A (H1N1) infection in a series of immunocompromised patients. Eight immunocompromised patients with documented novel influenza A (H1N1) had CT imaging at our institution between May 2009 and August 2009. A total of 20 CTs (initial and follow-up) were reviewed for the presence, severity, and distribution of the following: ground glass opacity, consolidation, interlobular septal thickening, mosaic perfusion, airway wall thickening, airway dilatation, nodules, cysts, pleural effusion, pericardial effusion, lymphadenopathy, and air trapping. The most common findings were airway thickening/dilatation, peribronchial ground glass opacity, centrilobular nodules, and tree-in-bud opacities. Peripheral consolidation involving the lower lobes was also a common pattern. Findings frequently involved all lobes and were closely associated with either large or small airways. Two patients presented with atypical CT findings including focal lobar consolidation and patchy lower lobe consolidation with soft tissue centrilobular nodules. Most survivors showed near complete resolution of findings within 35Â days. CT scans in immunocompromised patients with novel influenza H1N1 commonly show a strong airway predominance of findings or peripheral areas of consolidation involving the lower lobes. A subset of patients with novel influenza A (H1N1) will show findings not typical of viral infection
How healthy and affordable are foods and beverages sold in school canteens? A cross-sectional study comparing menus from Victorian primary schools
Abstract
Objective:
Government policy guidance in Victoria, Australia, encourages schools to provide affordable, healthy foods in canteens. This study analysed the healthiness and price of items available in canteens in Victorian primary schools and associations with school characteristics.
Design:
Dietitians classified menu items (main, snack and beverage) using the red, amber and green traffic light system defined in the Victorian government’s School Canteens and Other School Food Services Policy. This system also included a black category for confectionary and high sugar content soft drinks which should not be supplied. Descriptive statistics and regressions were used to analyse differences in the healthiness and price of main meals, snacks and beverages offered, according to school remoteness, sector (government and Catholic/independent) size, and socio-economic position.
Setting:
State of Victoria, Australia
Participants:
A convenience sample of canteen menus drawn from three previous obesity prevention studies in forty-eight primary schools between 2016 and 2019.
Results:
On average, school canteen menus were 21 % ‘green’ (most healthy – everyday), 53 % ‘amber’ (select carefully), 25 % ‘red’ (occasional) and 2 % ‘black’ (banned) items, demonstrating low adherence with government guidelines. ‘Black’ items were more common in schools in regional population centres. ‘Red’ main meal items were cheaper than ‘green’% ‘black’ (banned) items, demonstrating low adherence with government guidelines. ‘Black’ items were more common in schools in regional population centres. ‘Red’ main meal items were cheaper than ‘green’ (mean difference –0·91 (–1·27, –0·57)) main meal items. In about 50 % of schools, the mean price of ‘red’ main meal, beverages and snack items were cheaper than ‘green’ items, or no ‘green’ alternative items were offered.
Conclusion:
In this sample of Victorian canteen menus, there was no evidence of associations of healthiness and pricing by school characteristics except for regional centres having the highest proportion of ‘black’ (banned) items compared with all other remoteness categories examined. There was low adherence with state canteen menu guidelines. Many schools offered a high proportion of ‘red’ food options and ‘black’ (banned) options, particularly in regional centres. Unhealthier options were cheaper than healthy options. More needs to be done to bring Victorian primary school canteen menus in line with guidelines
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