Origin of Lagrangian Intermittency in Drift-Wave Turbulence

The Lagrangian velocity statistics of dissipative drift-wave turbulence are investigated. For large values of the adiabaticity (or small collisionality), the probability density function of the Lagrangian acceleration shows exponential tails, as opposed to the stretched exponential or algebraic tails, generally observed for the highly intermittent acceleration of Navier-Stokes turbulence. This exponential distribution is shown to be a robust feature independent of the Reynolds number. For small adiabaticity, algebraic tails are observed, suggesting the strong influence of point-vortex-like dynamics on the acceleration. A causal connection is found between the shape of the probability density function and the autocorrelation of the norm of the acceleration

The agrin gene codes for a family of basal lamina proteins that differ in function and distribution

We isolated two cDNAs that encode isoforms of agrin, the basal lamina protein that mediates the motor neuron-induced aggregation of acetylcholine receptors on muscle fibers at the neuromuscular junction. Both proteins are the result of alternative splicing of the product of the agrin gene, but, unlike agrin, they are inactive in standard acetylcholine receptor aggregation assays. They lack one (agrin-related protein 1) or two (agrin-related protein 2) regions in agrin that are required for its activity. Expression studies provide evidence that both proteins are present in the nervous system and muscle and that, in muscle, myofibers and Schwann cells synthesize the agrin-related proteins while the axon terminals of motor neurons are the sole source of agrin

Extended methodology for determining wetting properties of porous media

[1] Because most methods for assessing the wettability of porous materials are restricted in their applicability, we developed two new methods for measuring contact angles and particle surface energy. The proposed methods (the Wilhelmy plate method (WPM) and the modified capillary rise method (MCRM)) were tested on 24 soils. For comparison, the water drop penetration time test (WDPTT) and the sessile drop method (SDM) were also applied. It was found that advancing contact angles, measured either with WPM or MCRM, agreed well in the range of 0° to 142°. Sessile drop contact angles were within the domain enclosed by the range of advancing and receding contact angles as determined with WPM. WDPTT, however, was only sensitive in the narrow range of 85° to 115°. We conclude that both WPM and MCRM are reliable methods for determining contact angles and particle surface energy over a wide range of porous material wettabilities

Delegation and supervision of health care assistants’ work in the daily management of uncertainty and the unexpected in clinical practice: invisible learning among newly qualified nurses

The invisibility of nursing work has been discussed in the international literature but not in relation to learning clinical skills. Evans and Guile’s (2012) theory of recontextualisation is used to explore the ways in which invisible or unplanned and unrecognised learning takes place as newly qualified nurses learn to delegate to and supervise the work of the health care assistant. In the British context, delegation and supervision are thought of as skills which are learnt ‘on the job’. We suggest that learning ‘on-the-job’ is the invisible construction of knowledge in clinical practice and that delegation is a particularly telling area of nursing practice which illustrates invisible learning. Using an ethnographic case study approach in three hospital sites in England from 2011-2014, we undertook participant observation, interviews with newly qualified nurses, ward managers and health care assistants. We discuss the invisible ways newly qualified nurses learn in the practice environment and present the invisible steps to learning which encompass the embodied, affective and social, as much as the cognitive components to learning. We argue that there is a need for greater understanding of the ‘invisible learning’ which occurs as newly qualified nurses learn to delegate and supervise

'Doing the writing' and 'working in parallel': how 'distal nursing' affects delegation and supervision in the emerging role of the newly qualified nurse

Background: The role of the acute hospital nurse has moved away from the direct delivery of patient care and more towards the management of the delivery of bedside care by healthcare assistants. How newly qualified nurses delegate to and supervise healthcare assistants is important as failures can lead to care being missed, duplicated and/or incorrectly performed. Objectives: The data described here form part of a wider study which explored how newly qualified nurses recontextualise knowledge into practice, and develop and apply effective delegation and supervision skills. This article analyses team working between newly qualified nurses and healthcare assistants, and nurses' balancing of administrative tasks with bedside care. Methods and Analysis: Ethnographic case studies were undertaken in three hospital sites in England, using a mixed methods approach involving: participant observations; interviews with 33 newly qualified nurses, 10 healthcare assistants and 12 ward managers. Data were analysed using thematic analysis, aided by the qualitative software NVivo. Findings:Multiple demands upon the newly qualified nurses' time, particularly the pressures tomaintain records, can influence how effectively they delegate to, and supervise, healthcare assistants. While some nurses and healthcare assistants work successfully together, others work ‘in parallel’ rather than as an efficient team. Conclusions: While some ward cultures and individual working styles promote effective team working, others lead to less efficient collaboration between newly qualified nurses and healthcare assistants. In particular the need for qualified nurses to maintain records can create a gap between them, and between nurses and patients. Newly qualified nurses require more assistance in managing their own time and developing successful working relationships with healthcare assistants

An international perspective. A survey of clinician views and practices from 16 countries

Objective: To gain an insight into speech and language therapists’ perspectives and practices on quality of life in aphasia. Participants and Methods: The International Association of Logopedics and Phoniatrics Aphasia Committee developed a survey questionnaire, which was delivered on-line, anonymously, through SurveyMonkey (November 2012 – April 2013) to clinicians working with people with aphasia in 16 countries across the world. Results: A large number of speech and language therapists responded to the survey, with 19/21 questions answered by 385 – 579 participants. Clinicians were well informed on what constitutes quality of life and viewed it as a complex construct influenced by health, participation, in/dependence, communication, personal factors, and environmental factors. In their clinical practice, they considered quality of life as important, used informal approaches to explore it and aimed to address quality of life goals; yet the majority did not evaluate quality of life in a systematic way. Conclusion: There is a need for training on quality of life to facilitate speech and language therapists to incorporate quality of life outcome measures in their interventions. There is also a need for further research on what interventions improve quality of life in aphasia

Neel order in doped quasi one-dimensional antiferromagnets

We study the Neel temperature of quasi one-dimensional S=1/2 antiferromagnets containing non-magnetic impurities. We first consider the temperature dependence of the staggered susceptibility of finite chains with open boundary conditions, which shows an interesting difference for even and odd length chains. We then use a mean field theory treatment to incorporate the three dimensional inter-chain couplings. The resulting Neel temperature shows a pronounced drop as a function of doping by up to a factor of 5.Comment: 4 pages in revtex4 format including 2 epsf-embedded figures. The latest version in PDF format is available from http://fy.chalmers.se/~eggert/papers/staggered.pd

Ventilatory and chronotropic incompetence during incremental and constant load exercise in end-stage renal disease:a comparative physiology study

Maximal O(2) uptake is impaired in end-stage renal disease (ESRD), reducing quality of life and longevity. While determinants of maximal exercise intolerance are well defined, little is known of limitation during submaximal constant load exercise. By comparing individuals with ESRD and healthy controls, the aim of this exploratory study was to characterize mechanisms of exercise intolerance in participants with ESRD by assessing cardiopulmonary physiology at rest and during exercise. Resting spirometry and echocardiography were performed in 20 dialysis-dependent participants with ESRD (age: 59 ± 12 yr, 14 men and 6 women) and 20 healthy age- and sex-matched controls. Exercise tolerance was assessed with ventilatory gas exchange and central hemodynamics during a maximal cardiopulmonary exercise test and 30 min of submaximal constant load exercise. Left ventricular mass (292 ± 102 vs. 185 ± 83 g, P = 0.01) and filling pressure (E/e′: 6.48 ± 3.57 vs. 12.09 ± 6.50 m/s, P = 0.02) were higher in participants with ESRD; forced vital capacity (3.44 ± 1 vs. 4.29 ± 0.95 L/min, P = 0.03) and peak O(2) uptake (13.3 ± 2.7 vs. 24.6 ± 7.3 mL·kg(−1)·min(−1), P < 0.001) were lower. During constant load exercise, the relative increase in the arterial-venous O(2) difference (13 ± 18% vs. 74 ± 18%) and heart rate (32 ± 18 vs. 75 ± 29%) were less in participants with ESRD despite exercise being performed at a higher percentage of maximum minute ventilation (48 ± 3% vs. 39 ± 3%) and heart rate (82 ± 2 vs. 64 ± 2%). Ventilatory and chronotropic incompetence contribute to exercise intolerance in individuals with ESRD. Both are potential targets for medical and lifestyle interventions

Air Pollution and Odor in Communities Near Industrial Swine Operations

BackgroundOdors can affect health and quality of life. Industrialized animal agriculture creates odorant compounds that are components of a mixture of agents that could trigger symptoms reported by neighbors of livestock operations.ObjectiveWe quantified swine odor episodes reported by neighbors and the relationships of these episodes with environmental measurements.MethodsBetween September 2003 and September 2005, 101 nonsmoking volunteers living within 1.5 mi of industrial swine operations in 16 neighborhoods in eastern North Carolina completed twice-daily odor diaries for approximately 2 weeks. Meteorological conditions, hydrogen sulfide, and particulate matter ≤ 10 μm in aerodynamic diameter (PM10) were monitored in each neighborhood. We used mixed models to partition odor variance within and between people and between neighborhoods, and to quantify relationships between environmental factors and odor.ResultsParticipants reported 1,655 episodes of swine odor. In nine neighborhoods, odor was reported on more than half of study-days. Odor ratings were related to temperature, PM10, and semivolatile PM10 in standard but not mixed models. In mixed models, odor increased 0.15 ± 0.05 units (mean ± SE) for a 1-ppb increase in H2S, and 0.45 ± 0.14 units for a 10-μg/m3 increase in PM10 at wind speeds > 6.75 miles per hour. The odds of reporting a change in daily activities due to odor increased 62% for each unit increase in average odor during the prior 12 hr (t-value = 7.17).ConclusionsThis study indicates that malodor from swine operations is commonly present in these communities and that the odors reported by neighbors are related to objective environmental measurements and interruption of activities of daily life

Preliminary site report for the 2005 ICDP-USGS deep corehole in the Chesapeake Bay impact crater

First report for the ICDP-USGS 1.7-km-deep corehole drilled into the central part of the Chesapeake Bay impact crater during 2005