944 research outputs found
Key Action Extraction for Learning Analytics
Proceedings of: 7th European Conference on Technology Enhanced Learning (EC-TEL 2012): 21st Century Learning for 21st Century Skills. Saarbrücken, Germany, September 18-21, 2012.Analogous to keywords describing the important and relevant content of a document we extract key actions from learners' usage data assuming that they represent important and relevant parts of their learning behaviour. These key actions enable the teachers to better understand the dynamics in their classes and the problems that occur while learning. Based on these insights, teachers can intervene directly as well as improve the quality of their learning material and learning design. We test our approach on usage data collected in a large introductory C programming course at a university and discuss the results based on the feedback of the teachers.Work partially funded by the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement no 231396 (ROLE project), the Learn3 project (TIN2008-05163/TSI), the eMadrid project (S2009/TIC-1650), and the Acci´on Integrada DE2009-0051.Publicad
Inducing the cosmological constant from five-dimensional Weyl space
We investigate the possibility of inducing the cosmological constant from
extra dimensions by embedding our four-dimensional Riemannian space-time into a
five-dimensional Weyl integrable space. Following approach of the induced
matter theory we show that when we go down from five to four dimensions, the
Weyl field may contribute both to the induced energy-tensor as well as to the
cosmological constant, or more generally, it may generate a time-dependent
cosmological parameter. As an application, we construct a simple cosmological
model which has some interesting properties.Comment: 7 page
Laboratory diagnosis of severe hypertriglyceridaemia. Cases from the dyslipidaemia regristy of the spanish atherosclerosis society
Background and Aims
Severe hypertriglyceridaemia (sHTG) increases the risk of cardiovascular disease and acute pancreatitis
episodes. Patients with sHTG fit mainly into two clinical entities: Familial or Multifactorial Chylomicronemia
Syndromes (FCS and MCS, respectively). FCS and MCS exhibit clinical differences but also separate genetic and
biochemical characteristics that can be assessed in the laboratory. The aim of this work has been to implement
a laboratory workflow to help diagnose sHTG patients with either FCS or MCS.
Methods
Patients with two fasting triglycerides >1000mg/dL determinations were sequenced with a capture probe
panel of 24 triglycerides-related genes using massive parallel sequencing (n=200). Two-step sequential
ultracentrifugation was performed (n= 159) to diagnose Type I hyperlipoproteinemia (HLP I) and post heparin
lipoprotein lipase activity was measured to discard or confirm its deficiency (n=60).
Results
Most patients had MCS as they: (i) did not exhibit HLPI and/or (ii) their genetic profile was not compatible with
FCS and (iii) were not deficient in LPL activity. FCS cases were identified as they had: (i) HLPI, and/or (ii) biallelic
pathogenic variants in LPL (n=5), GPIHBP1 (n=3), or LMF1 (n=2) genes and/or (iii) LPL activity deficiency. We
identified 4 FCS patients with HLPI, biallelic pathogenic variants in APOA5 but a rescued LPL activity. An
additional study of Apo-AV functionality was designed to confirm the FCS diagnosis in these cases.
Conclusions
Laboratory studies, in patients with severe hypertriglyceridaemia, provide with information of clinical utility to
distinguish between Familial and Multifactorial Chylomicronemia Syndromes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Effectiveness of rosuvastatin plus colchicine, emtricitabine/tenofovir and combinations thereof in hospitalized patients with COVID-19 : a pragmatic, open-label randomized trial
Q1Q1The use of rosuvastatin plus colchicine and emtricitabine/tenofovir in hospitalized patients with SARS-
CoV-2 disease (COVID-19) has not been assessed. The objective of this study was to assess the effectiveness and safety of rosuvastatin plus colchicine, emtricitabine/tenofovir, and their combined use in these patients.Revista Internacional - Indexad
New hadrons as ultra-high energy cosmic rays
Ultra-high energy cosmic ray (UHECR) protons produced by uniformly
distributed astrophysical sources contradict the energy spectrum measured by
both the AGASA and HiRes experiments, assuming the small scale clustering of
UHECR observed by AGASA is caused by point-like sources. In that case, the
small number of sources leads to a sharp exponential cutoff at the energy
E<10^{20} eV in the UHECR spectrum. New hadrons with mass 1.5-3 GeV can solve
this cutoff problem. For the first time we discuss the production of such
hadrons in proton collisions with infrared/optical photons in astrophysical
sources. This production mechanism, in contrast to proton-proton collisions,
requires the acceleration of protons only to energies E<10^{21} eV. The diffuse
gamma-ray and neutrino fluxes in this model obey all existing experimental
limits. We predict large UHE neutrino fluxes well above the sensitivity of the
next generation of high-energy neutrino experiments. As an example we study
hadrons containing a light bottom squark. These models can be tested by
accelerator experiments, UHECR observatories and neutrino telescopes.Comment: 17 pages, revtex style; v2: shortened, as to appear in PR
U(1) Invariant F(R) Horava-Lifshitz Gravity
This paper is devoted to the study of various aspects of projectable F(R)
Horava-Lifshitz (HL) gravity. We show that some versions of F(R) HL gravity may
have stable de Sitter solution and instable flat space solution. In this case,
the problem of scalar graviton does not appear because flat space is not vacuum
state. Generalizing the U(1) HL theory proposed in arXiv:1007.2410, we
formulate U(1) extension of scalar theory and of F(R) Horava-Lifshitz gravity.
The Hamiltonian approach for such the theory is developed in full detail. It is
demonstrated that its Hamiltonian structure is the same as for the
non-relativistic covariant HL gravity. The spectrum analysis performed around
flat background indicates towards the consistency of the theory because it
contains graviton with only transverse polarization. Finally, we analyze the
spatially-flat FRW equations for U(1) invariant F(R) Horava-Lifshitz gravity.Comment: 26 pages, several mysprints correcte
Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at \snn=130 GeV
Mid-rapidity transverse mass spectra and multiplicity densities of charged
and neutral kaons are reported for Au+Au collisions at \snn=130 GeV at RHIC.
The spectra are exponential in transverse mass, with an inverse slope of about
280 MeV in central collisions. The multiplicity densities for these particles
scale with the negative hadron pseudo-rapidity density. The charged kaon to
pion ratios are and
for the most central collisions. The ratio is lower than the same
ratio observed at the SPS while the is higher than the SPS result.
Both ratios are enhanced by about 50% relative to p+p and +p
collision data at similar energies.Comment: 6 pages, 3 figures, 1 tabl
Demonstration of the temporal matter-wave Talbot effect for trapped matter waves
We demonstrate the temporal Talbot effect for trapped matter waves using
ultracold atoms in an optical lattice. We investigate the phase evolution of an
array of essentially non-interacting matter waves and observe matter-wave
collapse and revival in the form of a Talbot interference pattern. By using
long expansion times, we image momentum space with sub-recoil resolution,
allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure
Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV
We present the first measurement of directed flow () at RHIC. is
found to be consistent with zero at pseudorapidities from -1.2 to 1.2,
then rises to the level of a couple of percent over the range . The latter observation is similar to data from NA49 if the SPS rapidities
are shifted by the difference in beam rapidity between RHIC and SPS.
Back-to-back jets emitted out-of-plane are found to be suppressed more if
compared to those emitted in-plane, which is consistent with {\it jet
quenching}. Using the scalar product method, we systematically compared
azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow
from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure
Azimuthal anisotropy: the higher harmonics
We report the first observations of the fourth harmonic (v_4) in the
azimuthal distribution of particles at RHIC. The measurement was done taking
advantage of the large elliptic flow generated at RHIC. The integrated v_4 is
about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8)
harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding
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