3,979 research outputs found
A modular methodology for converting large, complex books into usable, accessible and standards-compliant ebooks
This report describes the methodology used for ebook creation for the Glasgow Digital Library (GDL), and provides detailed instructions on how the same methodology could be used elsewhere. The document includes a description and explanation of the processes for ebook creation followed by a tutorial
Subject searching requirements : the HILT II experience
The HILT Phase II project aimed to develop a pilot terminologies server with a view to improving cross-sectoral information retrieval. In order to inform this process, it was first necessary to examine how a representative group of users approached a range of information-related tasks. This paper focuses on exploratory interviews conducted to investigate the proposed ideal and actual strategies of a group of 30 users in relation to eight separate information tasks. In addition, users were asked to give examples of search terms they may employ and to describe how they would formulate search queries in each scenario. The interview process undertaken and the results compiled are outlined, and associated implications for the development of a pilot terminologies server are discussed
Greening information management: final report
As the recent JISC report on âthe âgreeningâ of ICT in education [1] highlights, the increasing reliance on ICT to underpin the business functions of higher education institutions has a heavy environmental impact, due mainly to the consumption of electricity to run computers and to cool data centres. While work is already under way to investigate how more energy efficient ICT can be introduced, to date there has been much less focus on the potential environmental benefits to be accrued from reducing the demand âat sourceâ through better data and information management. JISC thus commissioned the University of Strathclyde to undertake a study to gather evidence that establishes the efficacy of using information management options as components of Green ICT strategies within UK Higher Education environments, and to highlight existing practices which have the potential for wider replication
Testing quantised inertia on galactic scales
Galaxies and galaxy clusters have rotational velocities apparently too fast
to allow them to be gravitationally bound by their visible matter. This has
been attributed to the presence of invisible (dark) matter, but so far this has
not been directly detected. Here, it is shown that a new model that modifies
inertial mass by assuming it is caused by Unruh radiation, which is subject to
a Hubble-scale (Theta) Casimir effect predicts the rotational velocity (v) to
be: v^4=2GMc^2/Theta (the Tully-Fisher relation) where G is the gravitational
constant, M is the baryonic mass and c is the speed of light. The model
predicts the outer rotational velocity of dwarf and disk galaxies, and galaxy
clusters, within error bars, without dark matter or adjustable parameters, and
makes a prediction that local accelerations should remain above 2c^2/Theta at a
galaxy's edge.Comment: 7 pages, 1 figure. Accepted for publication in Astrophysics and Space
Science on 27/7/201
Association Between Blood Pressure and Adverse Renal Events in Type 1 Diabetes.
ObjectiveTo compare different blood pressure (BP) levels in their association with the risk of renal outcomes in type 1 diabetes and to determine whether an intensive glycemic control strategy modifies this association.Research design and methodsWe included 1,441 participants with type 1 diabetes between the ages of 13 and 39 years who had previously been randomized to receive intensive versus conventional glycemic control in the Diabetes Control and Complications Trial (DCCT). The exposures of interest were time-updated systolic BP (SBP) and diastolic BP (DBP) categories. Outcomes included macroalbuminuria (>300 mg/24 h) or stage III chronic kidney disease (CKD) (sustained estimated glomerular filtration rate <60 mL/min/1.73 m2).ResultsDuring a median follow-up time of 24 years, there were 84 cases of stage III CKD and 169 cases of macroalbuminuria. In adjusted models, SBP in the <120 mmHg range was associated with a 0.59 times higher risk of macroalbuminuria (95% CI 0.37-0.95) and a 0.32 times higher risk of stage III CKD (95% CI 0.14-0.75) compared with SBPs between 130 and 140 mmHg. DBP in the <70 mmHg range were associated with a 0.73 times higher risk of macroalbuminuria (95% CI 0.44-1.18) and a 0.47 times higher risk of stage III CKD (95% CI 0.21-1.05) compared with DBPs between 80 and 90 mmHg. No interaction was noted between BP and prior DCCT-assigned glycemic control strategy (all P > 0.05).ConclusionsA lower BP (<120/70 mmHg) was associated with a substantially lower risk of adverse renal outcomes, regardless of the prior assigned glycemic control strategy. Interventional trials may be useful to help determine whether the currently recommended BP target of 140/90 mmHg may be too high for optimal renal protection in type 1 diabetes
Gaussian processes Correlated Bayesian Additive Regression Trees
In recent years, Bayesian Additive Regression Trees (BART) has garnered
increased attention, leading to the development of various extensions for
diverse applications. However, there has been limited exploration of its
utility in analyzing correlated data. This paper introduces a novel extension
of BART, named Correlated BART (CBART). Unlike the original BART with
independent errors, CBART is specifically designed to handle correlated
(dependent) errors. Additionally, we propose the integration of CBART with
Gaussian processes (GP) to create a new model termed GP-CBART. This innovative
model combines the strengths of the Gaussian processes and CBART, making it
particularly well-suited for analyzing time series or spatial data. In the
GP-CBART framework, CBART captures the nonlinearity in the mean regression
(covariates) function, while the Gaussian processes adeptly models the
correlation structure within the response. Additionally, given the high
flexibility of both CBART and GP models, their combination may lead to
identification issues. We provide methods to address these challenges. To
demonstrate the effectiveness of CBART and GP-CBART, we present corresponding
simulated and real-world examples
On the Nature of Precursors in the Radio Pulsar Profiles
In the average profiles of several radio pulsars, the main pulse is
accompanied by the preceding component. This so called precursor is known for
its distinctive polarization, spectral, and fluctuation properties. Recent
single-pulse observations hint that the sporadic activity at the extreme
leading edge of the pulse may be prevalent in pulsars. We for the first time
propose a physical mechanism of this phenomenon. It is based on the induced
scattering of the main pulse radiation into the background. We show that the
scattered component is directed approximately along the ambient magnetic field
and, because of rotational aberration in the scattering region, appears in the
pulse profile as a precursor to the main pulse. Our model naturally explains
high linear polarization of the precursor emission, its spectral and
fluctuation peculiarities as well as suggests a specific connection between the
precursor and the main pulse at widely spaced frequencies. This is believed to
stimulate multifrequency single-pulse studies of intensity modulation in
different pulsars.Comment: 5 pages, no figures. Accepted for publication in MNRAS Letter
PHYSICAL SEPARATION OF HEMOPOIETIC STEM CELLS DIFFERING IN THEIR CAPACITY FOR SELF-RENEWAL
Bone marrow cells in suspension were separated into a number of fractions on the basis of cell size by sedimentation at unit gravity through gradients of fetal calf serum. The colony forming units (CFU) from the various fractions were tested for their self-renewal capacity using a double transplantation technique. The results indicate that the CFU in the fractions containing slowly sedimenting cells have an increased capacity for self-renewal in comparison with CFU in fractions containing rapidly sedimenting cells. In addition, a culture method was used to select populations containing CFU with increased self-renewal capacity, and these CFU were shown to sediment slowly in comparison with CFU of lower self-renewal capacity obtained from control cultures. It may be concluded that at least part of the heterogeneity observed in the CFU content of individual spleen colonies arises from the composition of the initial cell suspension, probably from intrinsic differences between the stem cells themselves
Lanczos algorithm with Matrix Product States for dynamical correlation functions
The density-matrix renormalization group (DMRG) algorithm can be adapted to
the calculation of dynamical correlation functions in various ways which all
represent compromises between computational efficiency and physical accuracy.
In this paper we reconsider the oldest approach based on a suitable
Lanczos-generated approximate basis and implement it using matrix product
states (MPS) for the representation of the basis states. The direct use of
matrix product states combined with an ex-post reorthogonalization method
allows to avoid several shortcomings of the original approach, namely the
multi-targeting and the approximate representation of the Hamiltonian inherent
in earlier Lanczos-method implementations in the DMRG framework, and to deal
with the ghost problem of Lanczos methods, leading to a much better convergence
of the spectral weights and poles. We present results for the dynamic spin
structure factor of the spin-1/2 antiferromagnetic Heisenberg chain. A
comparison to Bethe ansatz results in the thermodynamic limit reveals that the
MPS-based Lanczos approach is much more accurate than earlier approaches at
minor additional numerical cost.Comment: final version 11 pages, 11 figure
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