56,626 research outputs found
Building info-skills by degrees : embedding information literacy in university study
Late last year teaching staff at Griffith University participated in a symposium entitled 'Spotlight on Generic Skills & Flexible Learning'. This event brought together academic staff as well as library staff, learning advisers and other support staff interested in teaching and learning issues. The discussion was based on the premise that the University has a responsibility to ensure that its courses emphasise broad educational values and 'produce highly sought after graduates with globally applicable skills for the international market'(1). It was acknowledged that the University consistently scores very highly with graduates for its development of generic skills. However at the same time staff expressed concern at the challenge of developing more flexible, student-centred learning environments that have generic skills embedded across all programs (2). As a result there has been much debate in the University about which skills are important, how they will be acquired and how they could effectively be built into the curriculum. One outcome of these discussions is the project described in this paper. What follows is an overview of the project and a discussion about the integration and development of information literacy as a generic attribute in the curriculum and some suggestions on ways forward
Nonabelian Duality and Solvable Large N Lattice Systems
We introduce the basics of the nonabelian duality transformation of SU(N) or
U(N) vector-field models defined on a lattice. The dual degrees of freedom are
certain species of the integer-valued fields complemented by the symmetric
groups' \otimes_{n} S(n) variables. While the former parametrize relevant
irreducible representations, the latter play the role of the Lagrange
multipliers facilitating the fusion rules involved. As an application, I
construct a novel solvable family of SU(N) D-matrix systems graded by the rank
1\leq{k}\leq{(D-1)} of the manifest [U(N)]^{\oplus k} conjugation-symmetry.
Their large N solvability is due to a hidden invariance (explicit in the dual
formulation) which allows for a mapping onto the recently proposed
eigenvalue-models \cite{Dub1} with the largest k=D symmetry. Extending
\cite{Dub1}, we reconstruct a D-dimensional gauge theory with the large N free
energy given (modulo the volume factor) by the free energy of a given proposed
1\leq{k}\leq{(D-1)} D-matrix system. It is emphasized that the developed
formalism provides with the basis for higher-dimensional generalizations of the
Gross-Taylor stringy representation of strongly coupled 2d gauge theories.Comment: TeX, 46 page
Surface transects for arsenic speciation, antimony speciation, and alkaline phosphatase activity from R/V Knorr cruise KN204-01 in the Subtropical North Atlantic Ocean in 2011 (U.S. GEOTRACES NAT project)
Dataset: GT11 - As AP Surface TransectsSurface transects for arsenic speciation, antimony speciation, and alkaline phosphatase activity. Data for the concentrations of the dissolved (<0.4 µm) arsenic species: total inorganic As (III+V), arsenite (AsIII), As(V), monomethyl As, dimethyl As, and the activity of the enzyme alkaline phosphatase (unfiltered).
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3830NSF Division of Ocean Sciences (NSF OCE) OCE-0926423, NSF Division of Ocean Sciences (NSF OCE) OCE-092609
A conjugation-free geometric presentation of fundamental groups of arrangements II: Expansion and some properties
A conjugation-free geometric presentation of a fundamental group is a
presentation with the natural topological generators and the
cyclic relations: with no conjugations on the
generators.
We have already proved that if the graph of the arrangement is a disjoint
union of cycles, then its fundamental group has a conjugation-free geometric
presentation. In this paper, we extend this property to arrangements whose
graphs are a disjoint union of cycle-tree graphs.
Moreover, we study some properties of this type of presentations for a
fundamental group of a line arrangement's complement. We show that these
presentations satisfy a completeness property in the sense of Dehornoy, if the
corresponding graph of the arrangement has no edges. The completeness property
is a powerful property which leads to many nice properties concerning the
presentation (such as the left-cancellativity of the associated monoid and
yields some simple criterion for the solvability of the word problem in the
group).Comment: 17 pages, 9 figures; final version, which corrects a mistake in the
published versio
Ultrafilter spaces on the semilattice of partitions
The Stone-Cech compactification of the natural numbers bN, or equivalently,
the space of ultrafilters on the subsets of omega, is a well-studied space with
interesting properties. If one replaces the subsets of omega by partitions of
omega, one can define corresponding, non-homeomorphic spaces of partition
ultrafilters. It will be shown that these spaces still have some of the nice
properties of bN, even though none is homeomorphic to bN. Further, in a
particular space, the minimal height of a tree pi-base and P-points are
investigated
Fast Bayesian inference for slow-roll inflation
We present and discuss a new approach increasing by orders of magnitude the
speed of performing Bayesian inference and parameter estimation within the
framework of slow-roll inflation. The method relies on the determination of an
effective likelihood for inflation which is a function of the primordial
amplitude of the scalar perturbations complemented with the necessary number of
the so-called Hubble flow functions to reach the desired accuracy. Starting
from any cosmological data set, the effective likelihood is obtained by
marginalisation over the standard cosmological parameters, here viewed as
"nuisance" from the early Universe point of view. As being low-dimensional,
basic machine-learning algorithms can be trained to accurately reproduce its
multidimensional shape and then be used as a proxy to perform fast Bayesian
inference on the inflationary models. The robustness and accuracy of the method
are illustrated using the Planck Cosmic Microwave Background (CMB) data to
perform primordial parameter estimation for the large field models of
inflation. In particular, marginalised over all possible reheating history, we
find the power index of the potential to verify p < 2.3 at 95% of confidence.Comment: 10 pages, 4 figures, uses mn2e. References added, matches published
versio
Dark Matter, Modified Gravity and the Mass of the Neutrino
It has been suggested that Einstein's theory of General Relativity can be
modified to accomodate mismatches between the gravitational field and luminous
matter on a wide range of scales. Covariant theories of modified gravity
generically predict the existence of extra degrees of freedom which may be
interpreted as dark matter. We study a subclass of these theories where the
overall energy density in these extra degrees of freedom is subdominant
relative to the baryon density and show that they favour the presence of
massive neutrinos. For some specific cases (such as a flat Universes with a
cosmological constant) one finds a conservative lower bound on the neutrinos
mass of eV.Comment: 5 pages, 2 figures, 2 tables, submitted to Phys. Rev.
A Note on Circle Compactification of Tensile Ambitwistor String
We discuss a number of problems associated with the circle compactification
of the bosonic tensile ambitwistor string with the asymmetric vacuum choice. By
considering the spectrum and physical state conditions, we show that the circle
radius plays a role as a tuning parameter which determines the low energy
effective field theory. At the self dual point, we construct the current
operators and compute OPEs between them. While the final outcome remains as yet
inconclusive, several new results are obtained. Through the current algebra
analysis we show that there is a subsector of the massless states where the
gauge symmetry is enhanced to . Using the fact that the
one loop partition function is not modular invariant, we show that tensile
ambitwistor string partition function is exactly the same as a field theory
partition function. Our result proves that despite the existence of winding
modes, which is a typical characteristic of a string, the tensile ambitwistor
string behaves as a point particle theory.Comment: 31 pages, v2: minor corrections, reference added, published in
Nucl.Phys.
- …