2,787 research outputs found
Abrupt wind regime changes in the North Atlantic Ocean during the past 30,000-60,000 years
The inputs of higher plants in Blake Outer Ridge (subtropical western North Atlantic) during marine
isotope stage 3 (MIS3) have been recorded at high resolution by quantification of C23–C33 odd carbon
numbered n-alkanes and C20–C30 even carbon numbered n-alkan-1-ols in sediment sections of Ocean Drilling
Program Site 1060. The changes of these proxies at this open marine site are mainly related to eolian inputs. Their concentrations and fluxes exhibit major abrupt variations that are correlated with Dansgaard/Oeschger (D/O) patterns in Greenland ice cores. The ratios between interstadials and stadials range between 2 and 9 times. The intense flux increases in the D/O stadials are linked to strong enhancements of the westerly wind regime at these subtropical latitudes during stadials. The observed variation was paralleled by changes in wind-blown dust and the polar circulation index in Greenland ice, which is in agreement with previously hypothesized atmospheric teleconnections between northern and middle-low latitudes of the Northern Hemisphere. The close correspondence between sedimentary and ice core proxies is evidence that crossings of the glacial climate thresholds involved major reorganizations of the troposphere. The observed large rise in higher plant biomarkers indicates that climate stabilization in the D/O stadial conditions led to main increases in wind intensity
Usage of social and semantic web technologies to design a searching architecture for software requirement artefacts
At present, the research community recognises a complementary relationship between the semantic
and the social web. The merging of these web instances could play an essential role in different knowledge
domains. In this study, the authors promote a social–semantic web paradigm using software engineering as
the knowledge domain specifically. The authors address a major problem – the difficulty for end-users in
finding documentation related to software requirements proposed by them; this fact reduces their
participation at the time of specifying the software requirements. Architecture is proposed for enhanced
resources search, combining the strengths of the social (social annotations) and semantic (semantic metadata)
technologies, which has been designed considering the search style of the information seekers. Such
architecture is applied in a use-scenario, where the expert users who are not technicians have some
restrictions and limitations to retrieve the documents they need. The preliminary results demonstrate that it
is possible to take advantage of the defined infrastructure of the ontology to organise and integrate the
metadata of resources which are in databases or existent files; this approach opens several possibilities as
creation and validation of software requirements collaboratively among different expert-users
The ISW-tSZ cross correlation: ISW extraction out of pure CMB data
If Dark Energy introduces an acceleration in the universal expansion then
large scale gravitational potential wells should be shrinking, causing a
blueshift in the CMB photons that cross such structures (Integrated Sachs-Wolfe
effect, [ISW]). Galaxy clusters are known to probe those potential wells. In
these objects, CMB photons also experience inverse Compton scattering off the
hot electrons of the intra-cluster medium, and this results in a distortion
with a characteristic spectral signature of the CMB spectrum (the so-called
thermal Sunyaev-Zel'dovich effect, [tSZ]). Since both the ISW and the tSZ
effects take place in the same potential wells, they must be spatially
correlated. We present how this cross ISW-tSZ signal can be detected in a
CMB-data contained way by using the frequency dependence of the tSZ effect in
multi frequency CMB experiments like {\it Planck}, {\em without} requiring the
use of external large scale structure tracers data. We find that by masking low
redshift clusters, the shot noise level decreases significantly, boosting the
signal to noise ratio of the ISW--tSZ cross correlation. We also find that
galactic and extragalactic dust residuals must be kept at or below the level of
~0.04 muK^2 at l=10, a limit that is a factor of a few below {\it Planck}'s
expectations for foreground subtraction. If this is achieved, CMB observations
of the ISW-tSZ cross correlation should also provide an independent probe for
the existence of Dark Energy and the amplitude of density perturbations.Comment: submitted to MNRA
An approach to emotion recognition in single-channel EEG signals: a mother child interaction
In this work, we perform a first approach to emotion recognition from EEG single channel signals extracted in four (4) mother-child dyads experiment in developmental psychology -- Single channel EEG signals are analyzed and processed using several window sizes by performing a statistical analysis over features in the time and frequency domains -- Finally, a neural network obtained an average accuracy rate of 99% of classification in two emotional states such as happiness and sadness20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin
Encouraging natural ventilation to improve indoor environmental conditions at schools. Case studies in the north of Spain before and during COVID
The COVID pandemic has strongly affected daily life both in Spanish schools and worldwide. Providing
the best environmental conditions for children allowing face-to-face learning with healthy and safe
indoor spaces is a challenge. In the present study, empirical research about how these environmental
conditions change with COVID is presented comparing the situation from March 2020 to January 2021.
The methodology combines surveys conducted in nine schools with a case study in a selected school
where a detailed monitoring of the building was developed during both heating seasons. This data ana-
lyzes the impact of the new COVID prevention protocols on indoor environmental conditions (especially
those related to natural ventilation). Results show a mean CO2 reduction of 1,400 ppm, having in the sec-
ond term values around 1,000 ppm, although temperatures diminished nearly 2 °C to mean values of
18 °C. Evolution of temperature and CO2 concentration throughout the day was also analyzed, being these
indoor conditions especially important for the children with poorer health. Mechanical ventilation with
heating recovery should complement natural ventilation, at least during the coldest months or hours of
the day, although systems have to be carefully designed and installed to work effectively
Stretch-induced activation of pannexin 1 channels can be prevented by pka-dependent phosphorylation
Indexación ScopusPannexin 1 channels located in the cell membrane are permeable to ions, metabolites, and signaling molecules. While the activity of these channels is known to be modulated by phosphorylation on T198, T308, and S206, the possible involvement of other putative phosphorylation sites remains unknown. Here, we describe that the activity of Panx1 channels induced by mechanical stretch is reduced by adenosine via a PKA-dependent pathway. The mechanical stretch-induced activity—measured by changes in DAPI uptake—of Panx1 channels expressed in HeLa cell transfectants was inhibited by adenosine or cAMP analogs that permeate the cell membrane. Moreover, inhibition of PKA but not PKC, p38 MAPK, Akt, or PKG prevented the effects of cAMP analogs, suggesting the involvement of Panx1 phosphorylation by PKA. Accordingly, alanine substitution of T302 or S328, two putative PKA phosphorylation sites, prevented the inhibitory effect of cAMP analogs. Moreover, phosphomimetic mutation of either T302 or S328 to aspartate prevented the mechanical stretch-induced activation of Panx1 channels. A molecular dynamics simulation revealed that T302 and S328 are located in the water–lipid interphase near the lateral tunnel of the intracellular region, suggesting that their phosphorylation could promote conformational changes in lateral tunnels. Thus, Panx1 phosphorylation via PKA could be modulated by G protein-coupled receptors associated with the Gs subunit. © 2020, MDPI AG. All rights reserved.https://www.mdpi.com/1422-0067/21/23/918
Phosphoproteomic analysis of neoadjuvant breast cancer suggests that increased sensitivity to paclitaxel is driven by CDK4 and filamin A
Precision oncology research is challenging outside the contexts of oncogenic addiction and/or targeted therapies. We previously showed that phosphoproteomics is a powerful approach to reveal patient subsets of interest characterized by the activity of a few kinases where the underlying genomics is complex. Here, we conduct a phosphoproteomic screening of samples from HER2-negative female breast cancer receiving neoadjuvant paclitaxel (N = 130), aiming to find candidate biomarkers of paclitaxel sensitivity. Filtering 11 candidate biomarkers through 2 independent patient sets (N= 218) allowed the identification of a subgroup of patients characterized by high levels of CDK4 and filamin-A who had a 90% chance of achieving a pCR in response to paclitaxel. Mechanistically, CDK4 regulates filamin-A transcription, which in turn forms a complex with tubulin and CLIP-170, which elicits increased binding of paclitaxel to microtubules, microtubule acetylation and stabilization, and mitotic catastrophe. Thus, phosphoproteomics allows the identification of explainable factors for predicting response to paclitaxel
The intrinsic shape of galaxy bulges
The knowledge of the intrinsic three-dimensional (3D) structure of galaxy
components provides crucial information about the physical processes driving
their formation and evolution. In this paper I discuss the main developments
and results in the quest to better understand the 3D shape of galaxy bulges. I
start by establishing the basic geometrical description of the problem. Our
understanding of the intrinsic shape of elliptical galaxies and galaxy discs is
then presented in a historical context, in order to place the role that the 3D
structure of bulges play in the broader picture of galaxy evolution. Our
current view on the 3D shape of the Milky Way bulge and future prospects in the
field are also depicted.Comment: Invited Review to appear in "Galactic Bulges" Editors: Laurikainen
E., Peletier R., Gadotti D. Springer Publishing. 24 pages, 7 figure
All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV
We report on the measurement of the all-particle cosmic ray energy spectrum
with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range
10 to 500 TeV. HAWC is a ground based air-shower array deployed on the slopes
of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to
gamma rays and cosmic rays at TeV energies. The data used in this work were
taken from 234 days between June 2016 to February 2017. The primary cosmic-ray
energy is determined with a maximum likelihood approach using the particle
density as a function of distance to the shower core. Introducing quality cuts
to isolate events with shower cores landing on the array, the reconstructed
energy distribution is unfolded iteratively. The measured all-particle spectrum
is consistent with a broken power law with an index of prior to
a break at ) TeV, followed by an index of . The
spectrum also respresents a single measurement that spans the energy range
between direct detection and ground based experiments. As a verification of the
detector response, the energy scale and angular resolution are validated by
observation of the cosmic ray Moon shadow's dependence on energy.Comment: 16 pages, 11 figures, 4 tables, submission to Physical Review
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
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