285 research outputs found
Wind retrieval from temperature measurements from the Rover Environmental Monitoring Station/Mars Science Laboratory
We are grateful to the entire MSL Curiosity rover team and to the REMS instrument team, in particular, for their work on the wind data on Mars, without which this research could not have been performed. MPZ has been partially funded by the Spanish State Research Agency (AEI) Project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (CSIC-INTA). The resources used for the simulations presented in this work were provided by the Graduate School of Space Technology of Luleå University of Technology. We give special thanks to Ricardo M. Fonseca for his useful comments and suggestions on this work that extended the horizons of this research from the beginning.Peer reviewedPublisher PD
Development of a wind retrieval method for low-speed low-pressure flows for ExoMars
Acknowledgements: The HABIT FM and EQM were manufactured by Omnisys Instruments AB, Sweden, in cooperation with the Luleå University of Technology (LTU). The HABIT project was funded by the Swedish National Space Agency (SNSA). We thank the ExoMars project team, European Space Agency (ESA), Roscosmos, Space Research Institute (IKI) and Omnisys Instruments AB for their hard work on the ExoMars 2022 mission. We acknowledge the Luleå University of Technology, the Wallenberg Foundation and the Kempe Foundation for support of the Mars research activities. ASS acknowledges the support of the LTU Graduate School of Space Technology. MPZ has been partially funded by the Spanish State Research Agency (AEI) Project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”-Centro de Astrobiología (INTA-CSIC). We acknowledge the support of Mr. Jens Jacob Iversen and Dr. Jonathan P. Merrison from the Aarhus Wind Tunnel of the Aarhus University (Denmark).Peer reviewedPublisher PD
The natural hallucinogen 5-MeO-DMT, component of Ayahuasca, disrupts cortical function in rats: reversal by antipsychotic drugs
5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a natural hallucinogen component of Ayahuasca, an Amazonian beverage traditionally used for ritual, religious and healing purposes that is being increasingly used for recreational purposes in US and Europe. 5MeO-DMT is of potential interest for schizophrenia research owing to its hallucinogenic properties. Two other psychotomimetic agents, phencyclidine and 2,5-dimethoxy-4-iodo-phenylisopropylamine (DOI), markedly disrupt neuronal activity and reduce the power of low frequency cortical oscillations (<4 Hz, LFCO) in rodent medial prefrontal cortex (mPFC). Here we examined the effect of 5-MeO-DMT on cortical function and its potential reversal by antipsychotic drugs. Moreover, regional brain activity was assessed by blood-oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). 5-MeO-DMT disrupted mPFC activity, increasing and decreasing the discharge of 51 and 35% of the recorded pyramidal neurons, and reducing (−31%) the power of LFCO. The latter effect depended on 5-HT1A and 5-HT2A receptor activation and was reversed by haloperidol, clozapine, risperidone, and the mGlu2/3 agonist LY379268. Likewise, 5-MeO-DMT decreased BOLD responses in visual cortex (V1) and mPFC. The disruption of cortical activity induced by 5-MeO-DMT resembles that produced by phencyclidine and DOI. This, together with the reversal by antipsychotic drugs, suggests that the observed cortical alterations are related to the psychotomimetic action of 5-MeO-DMT. Overall, the present model may help to understand the neurobiological basis of hallucinations and to identify new targets in antipsychotic drug development
Rendimiento cognitivo en pacientes con trastorno mental grave
Los pacientes con enfermedad mental grave cursan con discapacidad funcional en área personal, familiar, social y laboral. El estudio valora el rendimiento cognitivo de pacientes crónicos de larga evolución. El tratamiento de rehabilitación psicosocial influye en el rendimiento cognitivo de estos pacientes
X-ray emission from the extended disks of spiral galaxies
We present a study of the X-ray properties of a sample of six nearby
late-type spiral galaxies based on XMM-Newton observations. Since our primary
focus is on the linkage between X-ray emission and star formation in extended,
extranuclear galactic disks, we have selected galaxies with near face-on aspect
and sufficient angular extent so as to be readily amenable to investigation
with the moderate spatial resolution afforded by XMM-Newton. After excluding
regions in each galaxy dominated by bright point sources, we study both the
morphology and spectral properties of the residual X-ray emission, comprised of
both diffuse emission and the integrated signal of the fainter discrete source
populations. The soft X-ray morphology generally traces the inner spiral arms
and shows a strong correlation with the distribution of UV light, indicative of
a close connection between the X-ray emission and recent star formation. The
soft (0.3-2 keV) X-ray luminosity to star formation rate (SFR) ratio varies
from 1-5 x 10^39 erg/s(/Msun/yr), with an indication that the lower range of
this ratio relates to regions of lower SFR density. The X-ray spectra are well
matched by a two-temperature thermal model with derived temperatures of
typically ~0.2 keV and ~0.65 keV, in line with published results for other
normal and star-forming galaxies. The hot component contributes a higher
fraction of the soft luminosity in the galaxies with highest X-ray/SFR ratio,
suggesting a link between plasma temperature and X-ray production efficiency.
The physical properties of the gas present in the galactic disks are consistent
with a clumpy thin-disk distribution, presumably composed of diffuse structures
such as superbubbles together with the integrated emission of unresolved
discrete sources including young supernova remnants.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Society. 17 pages, 6 figures, 7 table
Disentangling Vacancy Oxidation on Metallicity-Sorted Carbon Nanotubes
Pristine single-walled carbon nanotubes (SWCNTs) are rather inert to O
and N, which for low doses chemisorb only on defect sites or vacancies of
the SWCNTs at the ppm level. However, very low doping has a major effect on the
electronic properties and conductivity of the SWCNTs. Already at low O
doses (80 L), the X-ray photoelectron spectroscopy (XPS) O 1s signal becomes
saturated, indicating nearly all the SWCNT's vacancies have been oxidized. As a
result, probing vacancy oxidation on SWCNTs via XPS yields spectra with rather
low signal-to-noise ratios, even for metallicity-sorted SWCNTs. We show that,
even under these conditions, the first principles density functional theory
calculated Kohn-Sham O 1s binding energies may be used to assign the XPS O 1s
spectra for oxidized vacancies on SWCNTs into its individual components. This
allows one to determine the specific functional groups or bonding environments
measured. We find the XPS O 1s signal is mostly due to three O-containing
functional groups on SWCNT vacancies: epoxy (CO), carbonyl
(CCO), and ketene (CCO), as ordered by abundance. Upon
oxidation of nearly all the SWCNT's vacancies, the central peak's intensity for
the metallic SWCNT sample is 60\% greater than for the semiconducting SWCNT
sample. This suggests a greater abundance of O-containing defect structures on
the metallic SWCNT sample. For both metallic and semiconducting SWCNTs, we find
O does not contribute to the measured XPS O~1s spectra
An X-ray View of Star Formation in the Central 3 kpc of NGC 2403
Archival Chandra observations are used to study the X-ray emission associated
with star formation in the central region of the nearby SAB(s)cd galaxy NGC
2403. The distribution of X-ray emission is compared to the morphology visible
at other wavelengths using complementary Spitzer, GALEX, and ground-based
Halpha imagery. In general, the brightest extended X-ray emission is associated
with HII regions and to other star-forming structures but is more pervasive;
existing also in regions devoid of strong Halpha and UV emission. This X-ray
emission has the spectral properties of diffuse hot gas (kT ~ 0.2keV) whose
likely origin is in gas shock-heated by stellar winds and supernovae with < 20%
coming from faint unresolved X-ray point sources. This hot gas may be
slowly-cooling extra-planar remnants of past outflow events, or a disk
component that either lingers after local star formation activity has ended or
that has vented from active star-forming regions into a porous interstellar
medium.Comment: 25 pages, accepted to A
- …