318 research outputs found
Traditional versus hypertextual index in an on-line course on Oscillation and Wave Physics
An online course on Oscillation and Wave Physics (https://ocw.upc.edu/webs/42254/Acustica_EN/) was implemented. As the first objective, this article describes its main features, especially the two types of indexes for accessing the different items (a traditional linear index, and a hypertextual index based on a concept map). The second objective is to describe the studentsâ response to the one index in comparison to the other. As a qualitative response (perception), obtained from the studentsâ free comments, some advantages of the hypertextual index were found, for example, the ability to raise curiosity about physics contents, or the building of a convenient attitude for learning autonomously. Some drawbacks perceived, which are put into perspective, were the possible equivocal interpretation of the guiding questions, or the uncertainty about following the optimal order of items. As a quantitative response (performance in exams), a small but significant difference was found only for two subtopics related to cross-linked relationships between different conceptual aspects. This can be explained by a deeper internalization of these relationships through the concept map underlying the hypertextual index.Postprint (author's final draft
The development of a 16S rRNA gene based PCR for the identification of Streptococcus pneumoniae and comparison with four other species specific PCR assays
<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is one of the most frequently encountered pathogens in humans but its differentiation from closely related but less pathogenic streptococci remains a challenge.</p> <p>Methods</p> <p>This report describes a newly-developed PCR assay (Spne-PCR), amplifying a 217 bp product of the 16S rRNA gene of <it>S. pneumoniae</it>, and its performance compared to other genotypic and phenotypic tests.</p> <p>Results</p> <p>The new PCR assay designed in this study, proved to be specific at 57°C for <it>S. pneumoniae</it>, not amplifying <it>S. pseudopneumoniae </it>or any other streptococcal strain or any strains from other upper airway pathogenic species. PCR assays (psaA, LytA, ply, spn9802-PCR) were previously described for the specific amplification of <it>S. pneumoniae</it>, but <it>psaA</it>-PCR was the only one found not to cross-react with <it>S. pseudopneumoniae</it>.</p> <p>Conclusion</p> <p>Spne-PCR, developed for this study, and psaA-PCR were the only two assays which did not mis-identify <it>S. pseudopneumoniae </it>as <it>S. pneumoniae</it>. Four other PCR assays and the AccuProbe assay were unable to distinguish between these species.</p
Population-based prevalence of cervical infection with human papillomavirus genotypes 16 and 18 and other high risk types in Tlaxcala, Mexico
This study was supported by the National Institute of Public Health of
Mexico, the CoordinaciĂłn de InvestigaciĂłn en Salud del Instituto Mexicano
del Seguro Social, the SecretarĂa de Salud Tlaxcala, the Instituto Nacional de
las Mujeres, and the Consejo Nacional de Ciencia y TecnologĂa [FOSISS 2013
202468]. Additional support has been provided by Roche Diagnostics, BD
Diagnostics, DICIPA and Arbor Vita Corporation. The study sponsors did not
played a role in designing the study, collecting, analyzing or interpreting the
data, writing the report, or submitting this paper for publication. UC Berkeley
Center for Global Public Health, Schoeneman Grant, Joint Medical Program
Thesis Grant, and Cancer Research UK (C569/A10404)
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
Search for the rare decays and
A search for the rare decay of a or meson into the final
state is performed, using data collected by the LHCb experiment
in collisions at and TeV, corresponding to an integrated
luminosity of 3 fb. The observed number of signal candidates is
consistent with a background-only hypothesis. Branching fraction values larger
than for the decay mode are
excluded at 90% confidence level. For the decay
mode, branching fraction values larger than are excluded at
90% confidence level, this is the first branching fraction limit for this
decay.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-044.htm
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGOâs first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
Coastal high-frequency radars in the Mediterranean ??? Part 2: Applications in support of science priorities and societal needs
International audienceThe Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in coastal ocean observing systems worldwide, with more than half of the European sites located in the Mediterranean coastal areas. In this work, we present a review of existing HFR data multidisciplinary science-based applications in the Mediterranean Sea, primarily focused on meeting end-user and science-driven requirements, addressing regional challenges in three main topics: (i) maritime safety, (ii) extreme hazards and (iii) environmental transport process. Additionally, the HFR observing and monitoring regional capabilities in the Mediterranean coastal areas required to underpin the underlying science and the further development of applications are also analyzed. The outcome of this assessment has allowed us to provide a set of recommendations for future improvement prospects to maximize the contribution to extending science-based HFR products into societally relevant downstream services to support blue growth in the Mediterranean coastal areas, helping to meet the UN's Decade of Ocean Science for Sustainable Development and the EU's Green Deal goals
Coastal high-frequency radars in the Mediterranean ??? Part 1: Status of operations and a framework for future development
Due to the semi-enclosed nature of the Mediterranean
Sea, natural disasters and anthropogenic activities impose
stronger pressures on its coastal ecosystems than in any
other sea of the world.With the aim of responding adequately
to science priorities and societal challenges, littoral waters
must be effectively monitored with high-frequency radar
(HFR) systems. This land-based remote sensing technology
can provide, in near-real time, fine-resolution maps of the
surface circulation over broad coastal areas, along with reliable
directional wave and wind information. The main goal
of this work is to showcase the current status of the Mediterranean
HFR network and the future roadmap for orchestrated
actions. Ongoing collaborative efforts and recent progress of
this regional alliance are not only described but also connected
with other European initiatives and global frameworks,
highlighting the advantages of this cost-effective instrument
for the multi-parameter monitoring of the sea state.
Coordinated endeavors between HFR operators from different
multi-disciplinary institutions are mandatory to reach a
mature stage at both national and regional levels, striving to
do the following: (i) harmonize deployment and maintenance
practices; (ii) standardize data, metadata, and quality control
procedures; (iii) centralize data management, visualization,
and access platforms; and (iv) develop practical applications
of societal benefit that can be used for strategic planning and
informed decision-making in the Mediterranean marine environment.
Such fit-for-purpose applications can serve for
search and rescue operations, safe vessel navigation, tracking
of marine pollutants, the monitoring of extreme events,
the investigation of transport processes, and the connectivity
between offshore waters and coastal ecosystems. Finally, future
prospects within the Mediterranean framework are discussed
along with a wealth of socioeconomic, technical, and
scientific challenges to be faced during the implementatio
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