1,978 research outputs found
Yang-Baxter maps and the discrete KP hierarchy
We present a systematic construction of the discrete KP hierarchy in terms of SatoâWilson-type shift operators. Reductions of the equations in this hierarchy to 1+1-dimensional integrable lattice systems are considered, and the problems that arise with regard to the symmetry algebra underlying the reduced systems as well as the ultradiscretizability of these systems are discussed. A scheme for constructing ultradiscretizable reductions that give rise to YangâBaxter maps is explained in two explicit examples
Darboux dressing and undressing for the ultradiscrete KdV equation
We solve the direct scattering problem for the ultradiscrete Korteweg de
Vries (udKdV) equation, over for any potential with compact
(finite) support, by explicitly constructing bound state and non-bound state
eigenfunctions. We then show how to reconstruct the potential in the scattering
problem at any time, using an ultradiscrete analogue of a Darboux
transformation. This is achieved by obtaining data uniquely characterising the
soliton content and the `background' from the initial potential by Darboux
transformation.Comment: 41 pages, 5 figures // Full, unabridged version, including two
appendice
Materialities of clinical handover in intensive care: challenges of enactment and education
Abstract
The research is situated in a busy intensive care unit in a tertiary referral centre university hospital in Scotland. To date no research appears to have been done with a focus on handover in intensive care, across the professions involved, examining how handover is enacted. This study makes an original contribution to the practical and pedagogical aspects of handover in intensive care both in terms of the methodology used and also in terms of its findings.
In order to study handover a mixed methods approach has been adopted and fieldwork has been done in the ethnographic mode. Data has been audio recorded and transcribed and analysed to explore the clinical handovers of patients by doctors and nurses in this intensive care unit. Texts of both handover, and the artefacts involved, are reviewed. Material from journals, books, lectures and websites, including those for health care professionals, patients and relatives, and those in industry are explicated. This study explores the role of material artefacts and texts, such as the intensive care-based electronic patient record, the whiteboards in the doctorsâ office, and in the ward, in the enactment of handover. Through analysis of the data I explore some of the entanglements and ontologies of handover and the multiple things of healthcare: patients, information, equipment, activities, texts, ideas, diseases, staff, diagnoses, illnesses, floating texts, responsibility, a plan, a family. The doing of handover is framed theoretically through the empirical philosophy of Molâs identification of multiple ontologies in clinical practice (Mol, 2002). Each chapter is prefaced by a poem, each of which has relevant socio-material elements embedded in it. The significance of the findings of the research for both patient care and clinical education and learning is surfaced
Bäcklund transformations for noncommutative anti-self-dual Yang-Mills equations
We present Bäcklund transformations for the non-commutative anti-self-dual YangâMills equations where the gauge group is G = GL(2) and use it to generate a series of exact solutions from a simple seed solution. The solutions generated by this approach are represented in terms of quasi-determinants and belong to a non-commutative version of the AtiyahâWard ansatz. In the commutative limit, our results coincide with those by Corrigan, Fairlie, Yates and Goddard
COLONIZATION AND CULTURAL INTERACTION: EXPLORING THE EXPRESSION AND CONTINUATION OF ETHNIC IDENTITY IN SPANISH COLONIAL FEMALE RELIGIOUS INSTITUTIONS
Na discussĂŁo sobre a colonização espanhola da AmĂŠrica Latina, ĂŠ fundamental levar em consideração o impacto da Igreja CatĂłlica sobre as colĂ´nias espanholas. Instituiçþes religiosas influenciaram vĂĄrios aspectos da sociedade colonial, incluindo a economia, o sistema polĂtico e a ideologia. Conventos sĂŁo espaços interessantes para explorar os mecanismos de colonização, pois nĂŁo sĂł mantiveram as ideologias raciais e de classe trazidos da Espanha, mas tambĂŠm forneceram uma base moral e religiosa para a presença colonial. As freiras participavam ativamente no desenvolvimento e manutenção da sociedade de elite espanhola.
Quasideterminant solutions of a non-Abelian Hirota-Miwa equation
A non-Abelian version of the Hirota-Miwa equation is considered. In an
earlier paper [Nimmo (2006) J. Phys. A: Math. Gen. \textbf{39}, 5053-5065] it
was shown how solutions expressed as quasideterminants could be constructed for
this system by means of Darboux transformations. In this paper we discuss these
solutions from a different perspective and show that the solutions are
quasi-Pl\"{u}cker coordinates and that the non-Abelian Hirota-Miwa equation may
be written as a quasi-Pl\"{u}cker relation. The special case of the matrix
Hirota-Miwa equation is also considered using a more traditional, bilinear
approach and the techniques are compared
On a direct approach to quasideterminant solutions of a noncommutative KP equation
A noncommutative version of the KP equation and two families of its solutions
expressed as quasideterminants are discussed. The origin of these solutions is
explained by means of Darboux and binary Darboux transformations. Additionally,
it is shown that these solutions may also be verified directly. This approach
is reminiscent of the wronskian technique used for the Hirota bilinear form of
the regular, commutative KP equation but, in the noncommutative case, no
bilinearising transformation is available.Comment: 11 page
Resolving the decades-long transient FIRST J141918.9+394036: an orphan long gamma-ray burst or a young magnetar nebula?
Ofek (2017) identified FIRST J141918.9+394036 (hereafter FIRST J1419+3940) as
a radio source sharing similar properties and host galaxy type to the compact,
persistent radio source associated with the first known repeating fast radio
burst, FRB 121102. Law et al. (2018) showed that FIRST J1419+3940 is a
transient source decaying in brightness over the last few decades. One possible
interpretation is that FIRST J1419+3940 is a nearby analogue to FRB 121102 and
that the radio emission represents a young magnetar nebula (as several
scenarios assume for FRB 121102). Another interpretation is that FIRST
J1419+3940 is the afterglow of an `orphan' long gamma-ray burst (GRB). The
environment is similar to where most such events are produced. To distinguish
between these hypotheses, we conducted radio observations using the European
VLBI Network at 1.6 GHz to spatially resolve the emission and to search for
millisecond-duration radio bursts. We detect FIRST J1419+3940 as a compact
radio source with a flux density of (on 2018
September 18) and a source size of (i.e. given the angular diameter distance of ).
These results confirm that the radio emission is non-thermal and imply an
average expansion velocity of . Contemporaneous
high-time-resolution observations using the 100-m Effelsberg telescope detected
no millisecond-duration bursts of astrophysical origin. The source properties
and lack of short-duration bursts are consistent with a GRB jet expansion,
whereas they disfavor a magnetar birth nebula.Comment: 8 pages, 4 figures, accepted for publication in ApJ
Atmospheric Deposition: A Potential Source of Trace Metal Organic Complexing Ligands to the Marine Environment
The present study confirms the existence of rainwater and seawater soluble metal (Cu, Pb, Cd, Ni and Co) complexing organic ligands associated with end-member aerosol populations. The end member aerosols being representative of a European urban aerosol population (LUAP Âż Liverpool Urban Aerosol Population), and an aerosol population representative of crustal dominated material (Mesh Saharan dust, collected off the west African coast). The investigations carried out by ACSV (adsorptive cathodic stripping voltammetry) clearly indicated that these end-members were a source of organic complexing ligands for all the considered metals. For LUAP Cu 26%, Pb 55%, Cd 36%, Ni 26% and Co 27% of the total seawater soluble fraction was ACSVnon-labile (i.e. that fraction of the dissolved metal which is released after UV irradiation) compared to the corresponding values for Saharan dust (Cu 59%, Pb 23%, Cd 56%, Ni 66%, Co 23%). From these studies it was apparent that the dissolution for all metals and their respective fractions in both seawater and artificial rainwater was a rapid process with no further release after ca. 30 minutes. The studies displayed for a number of the metals re-adsorption of ACSVnon-labile metal to the aerosol particulate surface (Co and Pb - Saharan / seawater; Co and Cd - LUAP / seawater) implying that different geochemical pathways are taken by different metal speciation fractions leading to potential differences in their marine residence times. Conditional formation stability constants and complexing capacities for Ni were determined for seawater after being equilibrated with both end member aerosols. Log K\u27NiL detected were 18.3 - 0.3 and 19.26 - 0.4 for LUAP and Saharan dust respectively. The equivalent complexing capacities were 1.0 - 0.1 nmol mg-1 and 0.038 - 0.005 nmol mg-1 respectively
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