50,388 research outputs found
Ozone reference models for the middle atmosphere (new CIRA)
Models of ozone vertical structure were generated that were based on multiple data sets from satellites. The very good absolute accuracy of the individual data sets allowed the data to be directly combined to generate these models. The data used for generation of these models are from some of the most recent satellite measurements over the period 1978 to 1983. A discussion is provided of validation and error analyses of these data sets. Also, inconsistencies in data sets brought about by temporal variations or other factors are indicated. The models cover the pressure range from from 20 to 0.003 mb (25 to 90 km). The models for pressures less than 0.5 mb represent only the day side and are only provisional since there was limited longitudinal coverage at these levels. The models start near 25 km in accord with previous COSPAR international reference atmosphere (CIRA) models. Models are also provided of ozone mixing ratio as a function of height. The monthly standard deviation and interannual variations relative to zonal means are also provided. In addition to the models of monthly latitudinal variations in vertical structure based on satellite measurements, monthly models of total column ozone and its characteristic variability as a function of latitude based on four years of Nimbus 7 measurements, models of the relationship between vertical structure and total column ozone, and a midlatitude annual mean model are incorporated in this set of ozone reference atmospheres. Various systematic variations are discussed including the annual, semiannual, and quasibiennial oscillations, and diurnal, longitudinal, and response to solar activity variations
Chiral extrapolation beyond the power-counting regime
Chiral effective field theory can provide valuable insight into the chiral
physics of hadrons when used in conjunction with non-perturbative schemes such
as lattice QCD. In this discourse, the attention is focused on extrapolating
the mass of the rho meson to the physical pion mass in quenched QCD (QQCD).
With the absence of a known experimental value, this serves to demonstrate the
ability of the extrapolation scheme to make predictions without prior bias. By
using extended effective field theory developed previously, an extrapolation is
performed using quenched lattice QCD data that extends outside the chiral
power-counting regime (PCR). The method involves an analysis of the
renormalization flow curves of the low energy coefficients in a finite-range
regularized effective field theory. The analysis identifies an optimal
regulator, which is embedded in the lattice QCD data themselves. This optimal
regulator is the regulator value at which the renormalization of the low energy
coefficients is approximately independent of the range of quark masses
considered. By using recent precision, quenched lattice results, the
extrapolation is tested directly by truncating the analysis to a set of points
above 380 MeV, while being blinded of the results probing deeply into the
chiral regime. The result is a successful extrapolation to the chiral regime.Comment: 8 pages, 18 figure
Does the vocational curriculum have a future?
In this paper, which takes the form of a dialogue, we discuss the possible directions that vocational education might take in the contemporary social, economic and technological context of the early 21st century. Taking account of the unresolved debates around vocational education internationally and future global economic demands for expertise we discuss tensions and dichotomies that continue to shape the character of vocational education by questioning definitions of the ‘vocational’ historically and in current policy. These include: the relation between ‘vocational’ and ‘academic’ pathways and the possibility of their integration, the meaning of technical education, the purpose of vocational qualifications, the role of trade unions and employers, and whether there should be a ‘skills route’ for ‘low attainers’. The principal focus is on the English context, although the discussion draws on comparative examples where relevant, as well as broader factors likely to be significant in any country
Extending Bauer's corollary to fractional derivatives
We comment on the method of Dreisigmeyer and Young [D. W. Dreisigmeyer and P.
M. Young, J. Phys. A \textbf{36}, 8297, (2003)] to model nonconservative
systems with fractional derivatives. It was previously hoped that using
fractional derivatives in an action would allow us to derive a single retarded
equation of motion using a variational principle. It is proven that, under
certain reasonable assumptions, the method of Dreisigmeyer and Young fails.Comment: Accepted Journal of Physics A at www.iop.org/EJ/journal/JPhys
A Borel-Cantelli lemma for intermittent interval maps
We consider intermittent maps T of the interval, with an absolutely
continuous invariant probability measure \mu. Kim showed that there exists a
sequence of intervals A_n such that \sum \mu(A_n)=\infty, but \{A_n\} does not
satisfy the dynamical Borel-Cantelli lemma, i.e., for almost every x, the set
\{n : T^n(x)\in A_n\} is finite. If \sum \Leb(A_n)=\infty, we prove that
\{A_n\} satisfies the Borel-Cantelli lemma. Our results apply in particular to
some maps T whose correlations are not summable.Comment: 7 page
Virtual libraries of tissue and clinical samples: potential role of a 3-D microscope.
Our international innovative teaching group from different European Universities (De Montfort University, DMU, UK; and the Spanish University of Alcalá, University Miguel Hernández and University of San Pablo CEU), in conjunction with practicing biomedical scientists in the National Health Service (UK) and biomedical researchers, are developing two complete e-learning packages for teaching and learning medical parasitology, named DMU e-Parasitology (accessible at: http://parasitology.dmu.ac.uk), and biology and chemistry, named DMU e-Biology (accessible at: http://parasitology.dmu.ac.uk/ebiology/index.htm), respectively. Both packages will include a virtual microscope with a complete library of digitised tissue images, clinical slides and cell culture slides/mini-videos for enhancing the teaching and learning of a myriad of techniques applicable to health science undergraduate and postgraduate students. Thus, these packages include detecting human parasites, by becoming familiar with their infective structures and/or organs (e.g. eggs, cysts) and/or explore pathogenic tissues stained with traditional (e.g. haematoxylin & eosin) or more modern (e.g. immunohistochemistry) techniques. The Virtual Microscope (VM) module in the DMU e-Parasitology package is almost completed (accessible at: http://parasitology.dmu.ac.uk/learn/microscope.htm) and contains a section for the three major groups of human-pathogenic parasites (Peña-Fernández et al., 2018) [1]. Digitised slides are provided with the functionality of a microscope by using the gadget Zoomify®, and we consider that they can enhance learning, as previous studies reported in the literature have reported similar sensitivity and specificity rates for identification of parasites for both digitised and real slides. The DMU e-Biology’s VM, currently in development, will provide healthy and pathological tissue samples from a range of mammalian tissues and organs.
This communication will provide a description of both virtual libraries and the process of developing them. In conjunction, we will use a three-dimensional (3D) super-resolution microscopy, 3D Cell Explorer (Nanolive, Lausanne, Switzerland), to incorporate potential 3D microscopic photographs/short videos of cells to provide students with information about the spatial arrangement and morphologies of cells that are essential for life
Coupled SDW and Superconducting Order in FFLO State of CeCoIn
The mechanism of incommensurate (IC) spin-density-wave (SDW) order observed
in the Flude-Ferrell-Larkin-Ovchinnikov (FFLO) phase of CeCoIn is discussed
on the basis of new mode-coupling scheme among IC-SDW order, two
superconducting orders of FFLO with B () symmetry
and -pairing of odd-parity. Unlike the mode-coupling schemes proposed by
Kenzelmann et al, Sciencexpress, 21 August (2008), that proposed in the present
Letter can offer a simple explanation for why the IC-SDW order is observed only
in FFLO phase and the IC wave vector is rather robust against the magnetic
field.Comment: 3pages, 1 figure, accepted for publication in J. Phys. Soc. Jpn.,
Vol.77 (2008), No.1
Multicritical Points of Potts Spin Glasses on the Triangular Lattice
We predict the locations of several multicritical points of the Potts spin
glass model on the triangular lattice. In particular, continuous multicritical
lines, which consist of multicritical points, are obtained for two types of
two-state Potts (i.e., Ising) spin glasses with two- and three-body
interactions on the triangular lattice. These results provide us with numerous
examples to further verify the validity of the conjecture, which has succeeded
in deriving highly precise locations of multicritical points for several spin
glass models. The technique, called the direct triangular duality, a variant of
the ordinary duality transformation, directly relates the triangular lattice
with its dual triangular lattice in conjunction with the replica method.Comment: 18 pages, 2, figure
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