1,989 research outputs found
The Intensity Profile of the Solar Supergranulation
We have measured the average radial (cell center to network boundary) profile
of the continuum intensity contrast associated with supergranular flows using
data from the Precision Solar Photometric Telescope (PSPT) at the Mauna Loa
Solar Observatory (MLSO). After removing the contribution of the network flux
elements by the application of masks based on Ca II K intensity and averaging
over more than 10^5 supergranular cells, we find a ~ 0.1% decrease in red and
blue continuum intensity from the supergranular cell centers outward,
corresponding to a ~ 1.0 K decrease in brightness temperature across the cells.
The radial intensity profile may be caused either by the thermal signal
associated with the supergranular flows or a variation in the packing density
of unresolved magnetic flux elements. These are not unambiguously distinguished
by the observations, and we raise the possibility that the network magnetic
fields play an active role in supergranular scale selection by enhancing the
radiative cooling of the deep photosphere at the cell boundaries.Comment: Accepted to Ap
Methods for identifying surgical wound infection after discharge from hospital: a systematic review.
Background: Wound infections are a common complication of surgery that add significantly to the morbidity of patients and costs of treatment. The global trend towards reducing length of hospital stay post-surgery and the increase in day case surgery means that surgical site infections (SSI) will increasingly occur after hospital discharge. Surveillance of SSIs is important because rates of SSI are viewed as a measure of hospital performance, however accurate detection of SSIs post-hospital discharge is not straightforward. Methods: We conducted a systematic review of methods of post discharge surveillance for surgical wound infection and undertook a national audit of methods of post-discharge surveillance for surgical site infection currently used within United Kingdom NHS Trusts. Results: Seven reports of six comparative studies which examined the validity of post-discharge surveillance methods were located; these involved different comparisons and some had methodological limitations, making it difficult to identify an optimal method. Several studies evaluated automated screening of electronic records and found this to be a useful strategy for the identification of SSIs that occurred post discharge. The audit identified a wide range of relevant post-discharge surveillance programmes in England, Scotland and Wales and Northern Ireland; however, these programmes used varying approaches for which there is little supporting evidence of validity and/or reliability. Conclusion: In order to establish robust methods of surveillance for those surgical site infections that occur post discharge, there is a need to develop a method of case ascertainment that is valid and reliable post discharge. Existing research has not identified a valid and reliable method. A standardised definition of wound infection ( e. g. that of the Centres for Disease Control) should be used as a basis for developing a feasible, valid and reliable approach to defining post discharge SSI. At a local level, the method used to ascertain post discharge SSI will depend upon the purpose of the surveillance, the nature of available routine data and the resources available
The Cost of Increasing Adoption of Beneficial Nutrient-Management Practices
We estimate the cost of offsets tied to reductions in the use of nitrogen on U.S. cornfields under the proposed American Clean Energy and Security Act.offsets, nitrogen, corn, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy,
The extraordinary Hall effect in coherent epitaxial tau (Mn,Ni)Al thin films on GaAs
Ultrathin coherent epitaxial films of ferromagnetic tau(Mn,Ni)0.60Al0.40 have been grown by molecular beam epitaxy on GaAs substrates. X-ray scattering and cross-sectional transmission electron microscopy measurements confirm that the c axis of the tetragonal tau unit cell is aligned normal to the (001) GaAs substrate. Measurements of the extraordinary Hall effect (EHE) show that the films are perpendicularly magnetized, exhibiting EHE resistivities saturating in the range of 3.3-7.1 muOMEGA-cm at room temperature. These values of EHE resistivity correspond to signals as large as +7 and -7 mV for the two magnetic states of the film with a measurement current of 1 mA. Switching between the two magnetic states is found to occur at distinct field values that depend on the previously applied maximum field. These observations suggest that the films are magnetically uniform. As such, tau(Mn,Ni)Al films may be an excellent medium for high-density storage of binary information
Systematic review of EASY-care needs assessment for community-dwelling older people
Background:
Undertaking comprehensive geriatric assessments (CGAs) combined with long-term health and social care management can improve the quality of life of older people [ 1]. The EASY-Care tool is a CGA instrument designed for assessing the physical, mental and social functioning and unmet health and social needs of older people in community settings or primary care. It has also been used as a frailty assessment tool and for gathering population-level data.
Objective:
To review the evidence of reliability, validity and acceptability of EASY-Care and its appropriateness for assessing the needs of community-dwelling older people.
Methods:
Systematic search of literature databases using pre-defined search terms (January 1994—May 2014) for English language articles reporting on the reliability, validity, acceptability and implementation of EASY-Care in primary care and community settings. Eligible articles were critically reviewed. Discussion papers mapping professionals' use of the tool were also included as these could be considered an aspect of validity.
Results:
Twenty-nine papers met the inclusion criteria and underwent data extraction. A narrative synthesis was performed, because there was a variety of quantitative and qualitative outcomes and characteristics. Reliability evidence for EASY-Care is minimal. Evidence for validity is good, and it has received numerous positive endorsements of acceptability in international settings from older people and practitioners.
Conclusion:
Evidence supports the use of EASY-Care for individual needs assessment; further research is needed for other uses. Of the papers that made statements about who should administer EASY-Care, the majority indicated that nurses were preferable to self-completion
Classical and Quantum-like approaches to Charged-Particle Fluids in a Quadrupole
A classical description of the dynamics of a dissipative charged-particle
fluid in a quadrupole-like device is developed. It is shown that the set of the
classical fluid equations contains the same information as a complex function
satisfying a Schrodinger-like equation in which Planck's constant is replaced
by the time-varying emittance, which is related to the time-varying temperature
of the fluid. The squared modulus and the gradient of the phase of this complex
function are proportional to the fluid density and to the current velocity,
respectively. Within this framework, the dynamics of an electron bunch in a
storage ring in the presence of radiation damping and quantum-excitation is
recovered. Furthermore, both standard and generalized (including dissipation)
coherent states that may be associated with the classical particle fluids are
fully described in terms of the above formalism.Comment: LaTex, to appear in Physica Script
Commentary: risk factors for gastrointestinal bleeding in NSAID users – authors’ reply
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94297/1/apt12056.pd
The views of teachers in England on an action-oriented climate change curriculum
This is the final version. Available on open access from Routledge via the DOI in this recordTo inform current debate around climate change education (CCE)in the school curriculum in England, we surveyed the views of primary and secondary teachers(N=626). Results are compared with a 2018 poll of US teachers. In England, direct reference toclimate change in the National Curriculum is confined to secondary Science and Geographybut, unrelated to their subject area, teachers favoured a cross-curricular approach with most already communicating to their students about it.Feeling comfortabledelivering CCEwas correlated with reported resource availability, with most teachers considering only basic literacywas a greater funding priorityTeachers supported anaction-based CCE curriculum including issues of global social justice, beginningin primary school with mitigation projects such as conservation, local tree-planting and family advocacy. Local campaigning (e.g.,legal demonstration) was considered appropriate around the primary/secondary transition, with most supporting inclusion of civil disobedience but indicating this should begin at secondary school (11+years)
Risk factors associated with a decrease ≥2 g/dL in haemoglobin and/or ≥10% haematocrit in osteoarthritis patients taking celecoxib or a nonselective NSAID plus a PPI in a large randomised controlled trial ( CONDOR )
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92441/1/apt5213.pd
Realistic Earth escape strategies for solar sailing
With growing interest in solar sailing comes the requirement to provide a basis for future detailed planetary escape mission analysis by drawing together prior work, clarifying and explaining previously anomalies. Previously unexplained seasonal variations in sail escape times from Earth orbit are explained analytically and corroborated within a numerical trajectory model. Blended-sail control algorithms, explicitly independent of time, which providenear-optimal escape trajectories and maintain a safe minimum altitude and which are suitable as a potential autonomous onboard controller, are then presented. These algorithms are investigated from a range of initial conditions and are shown to maintain the optimality previously demonstrated by the use of a single-energy gain control law but without the risk of planetary collision. Finally, it is shown that the minimum sail characteristic acceleration required for escape from a polar orbit without traversing the Earth shadow cone increases exponentially as initial altitude is decreased
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