4,018 research outputs found
Chemotherapeutic agent 5-fluorouracil increases survival of SOD1 mouse model of ALS
Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease with no cure. Currently there are only two ALS drugs approved by the FDA, both with a limited therapeutic effect. In the search for drug candidates for ALS, we studied the effect of known stem cell mobilizing agents (treatment) and antimetabolite 5-fluorouracil (5-FU) (anti-treatment) in SOD1G93A model of ALS. Surprisingly, we found that anti-cancer drug 5-FU increases lifespan, delays the disease onset and improves motor performance in ALS mice. Although we were not able to demonstrate the mechanistic basis of the beneficial 5-FU action in ALS mice, our findings suggest that 5-FU or similar drugs are possible drug candidates for the treatment of motor neuron diseases through drug repurposing
Unravelling the combined use of soil and microbial technologies to optimize cultivation of Halophyte Limonium algarvense (Plumbaginaceae) using saline soils and water
Salt-affected soils have detrimental effects on agriculture and ecosystems. However,
these soils can still be used for halophyte (salt-tolerant plants) cultivation using brackish and/or
saline water. In this study, we employed soil technologies and mutualistic microorganisms as a
sustainable strategy to improve the growth and reproduction of the halophyte Limonium algarvense
Erben’s growth and reproduction under saline conditions. A microcosm assay was conducted under
controlled greenhouse conditions to cultivate L. algarvense using a saline Fluvisol (FLU) amended—or
not—with a Technosol (TEC). Plants were inoculated with the arbuscular mycorrhizal fungus (AMF)
Rhizoglomus irregulare and/or a consortium of plant growth-promoting bacteria (PGPB), and they
were irrigated with estuarine water. Soil enzyme analysis and physicochemical characterisation of
the soils, collected at the beginning and at the end of the assay, were carried out. The physiological
status of non-inoculated and inoculated plants was monitored during the assay for 4 months, and
AMF root colonisation was evaluated. In FLU, only plants inoculated with the AMF survived. These
plants had lower number of leaves, and shoot and root dry biomass than the ones grown in the TEC
by the end of the assay. In the TEC, PGPB inoculation led to higher NDVI and PRI values, and AMF
inoculation promoted higher reproductive development but not pollen fertility. The findings show
that the combined use of soil and microbial technologies can be successfully applied to cultivate
L. algarvense, suggesting their generalized use for other Limonium species with economic interest,
while contributing to the sustainable use of marginal lands.Federation of European Microbiological Societies (FEMS) (FEMSGO-
2020-203), University of Sevilla (Spain; Plan Propio de Investigación y Tranferencia 2021 Ayuda
A1-I.3A1) for grants to support the stays at ISA-ULisboa (Portugal).info:eu-repo/semantics/publishedVersio
The VIMOS-VLT Deep Survey: Evolution in the Halo Occupation Number since z 1
We model the evolution of the mean galaxy occupation of dark-matter halos
over the range , using the data from the VIMOS-VLT Deep Survey
(VVDS). The galaxy projected correlation function was computed for a
set of luminosity-limited subsamples and fits to its shape were obtained using
two variants of Halo Occupation Distribution models. These provide us with a
set of best-fitting parameters, from which we obtain the average mass of a halo
and average number of galaxies per halo. We find that after accounting for the
evolution in luminosity and assuming that we are largely following the same
population, the underlying dark matter halo shows a growth in mass with
decreasing redshift as expected in a hierarchical structure formation scenario.
Using two different HOD models, we see that the halo mass grows by 90% over the
redshift interval z=[0.5,1.0]. This is the first time the evolution in halo
mass at high redshifts has been obtained from a single data survey and it
follows the simple form seen in N-body simulations with , and . This provides evidence for a rapid accretion
phase of massive halos having a present-day mass , with a merger event occuring between redshifts of 0.5
and 1.0. Futhermore, we find that more luminous galaxies are found to occupy
more massive halos irrespectively of the redshift. Finally, the average number
of galaxies per halo shows little increase from redshift z 1.0 to z
0.5, with a sharp increase by a factor 3 from z 0.5 to z 0.1,
likely due to the dynamical friction of subhalos within their host halos.Comment: 14 pages, 6 figures, 5 tables. MNRAS accepted
Connecting stellar mass and star-formation rate to dark matter halo mass out to z ~ 2
We have constructed an extended halo model (EHM) which relates the total
stellar mass and star-formation rate (SFR) to halo mass (M_h). An empirical
relation between the distribution functions of total stellar mass of galaxies
and host halo mass, tuned to match the spatial density of galaxies over 0<z<2
and the clustering properties at z~0, is extended to include two different
scenarios describing the variation of SFR on M_h. We also present new
measurements of the redshift evolution of the average SFR for star-forming
galaxies of different stellar mass up to z=2, using data from the Herschel
Multi-tiered Extragalactic Survey (HerMES) for infrared-bright galaxies.
Combining the EHM with the halo accretion histories from numerical
simulations, we trace the stellar mass growth and star-formation history in
halos spanning a range of masses. We find that: (1) The intensity of the
star-forming activity in halos in the probed mass range has steadily decreased
from z~2 to 0; (2) At a given epoch, halos in the mass range between a few
times 10^{11} M_Sun and a few times 10^{12} M_Sun are the most efficient at
hosting star formation; (3) The peak of SFR density shifts to lower mass halos
over time; (4) Galaxies that are forming stars most actively at z~2 evolve into
quiescent galaxies in today's group environments, strongly supporting previous
claims that the most powerful starbursts at z~2 are progenitors of today's
elliptical galaxies.Comment: 15 pages, 12 figures, accepted for publication in MNRA
Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors
Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects
The CAMELS project: Cosmology and Astrophysics with MachinE Learning Simulations
We present the Cosmology and Astrophysics with MachinE Learning Simulations
--CAMELS-- project. CAMELS is a suite of 4,233 cosmological simulations of
volume each: 2,184 state-of-the-art
(magneto-)hydrodynamic simulations run with the AREPO and GIZMO codes,
employing the same baryonic subgrid physics as the IllustrisTNG and SIMBA
simulations, and 2,049 N-body simulations. The goal of the CAMELS project is to
provide theory predictions for different observables as a function of cosmology
and astrophysics, and it is the largest suite of cosmological
(magneto-)hydrodynamic simulations designed to train machine learning
algorithms. CAMELS contains thousands of different cosmological and
astrophysical models by way of varying , , and four
parameters controlling stellar and AGN feedback, following the evolution of
more than 100 billion particles and fluid elements over a combined volume of
. We describe the simulations in detail and
characterize the large range of conditions represented in terms of the matter
power spectrum, cosmic star formation rate density, galaxy stellar mass
function, halo baryon fractions, and several galaxy scaling relations. We show
that the IllustrisTNG and SIMBA suites produce roughly similar distributions of
galaxy properties over the full parameter space but significantly different
halo baryon fractions and baryonic effects on the matter power spectrum. This
emphasizes the need for marginalizing over baryonic effects to extract the
maximum amount of information from cosmological surveys. We illustrate the
unique potential of CAMELS using several machine learning applications,
including non-linear interpolation, parameter estimation, symbolic regression,
data generation with Generative Adversarial Networks (GANs), dimensionality
reduction, and anomaly detection.Comment: 33 pages, 18 figures, CAMELS webpage at
https://www.camel-simulations.or
Irinotecan+5-fluorouracil with concomitant pre-operative radiotherapy in locally advanced non-resectable rectal cancer: a phase I/II study
In the UK, 10% of patients diagnosed with rectal cancer have inoperable disease at presentation. This study ascertained whether the resectability rate of inoperable locally advanced rectal cancer was improved by administration of intravenous irinotecan, 5-fluorouracil (5-FU) and pelvic radiotherapy. During phase I of the trial (n=12), the dose of irinotecan was escalated in three-patient cohorts from 50 mg m−2 to 60 mg m−2 to 70 mg m−2 to identify the maximum tolerated dose (60 mg m−2). In phase II, 31 patients with non-resectable disease received 45 Gy radiotherapy and 5-FU infusions (200 mg m−2 per day) for 5 weeks. Irinotecan (60 mg m−2) was given on days 1, 8, 15 and 22. After treatment, patients were operated on if possible. Thirty patients completed the protocol, 28 underwent surgery. Before surgery, MRI restaging of 24 patients showed that 19 (79%) had a reduction in tumour stage after treatment (seven complete clinical response and 12 partial). Of 27 patients followed up after surgery, 22 (81%) had clear circumferential resection margins. Disease-free and overall survival estimates at 3 years were 65 and 90%, respectively. The regimen was well tolerated. Irinotecan, 5-FU and radiotherapy results in tumour downgrading, allowing resection of previously inoperable tumour with acceptable toxicity
Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV
We search for the standard model Higgs boson produced in association with an
electroweak vector boson in events with no identified charged leptons, large
imbalance in transverse momentum, and two jets where at least one contains a
secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1
integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV
recorded by the CDF II experiment at the Tevatron. We find 268 (16) single
(double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are
expected from standard model background processes. We place 95% confidence
level upper limits on the Higgs boson production cross section for several
Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115
GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model
prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let
Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II
We present a measurement of the fractions F_0 and F_+ of longitudinally
polarized and right-handed W bosons in top quark decays using data collected
with the CDF II detector. The data set used in the analysis corresponds to an
integrated luminosity of approximately 318 pb -1. We select ttbar candidate
events with one lepton, at least four jets, and missing transverse energy. Our
helicity measurement uses the decay angle theta*, which is defined as the angle
between the momentum of the charged lepton in the W boson rest frame and the W
momentum in the top quark rest frame. The cos(theta*) distribution in the data
is determined by full kinematic reconstruction of the ttbar candidates. We find
F_0 = 0.85 +0.15 -0.22 (stat) +- 0.06 (syst) and F_+ = 0.05 +0.11 -0.05 (stat)
+- 0.03 (syst), which is consistent with the standard model prediction. We set
an upper limit on the fraction of right-handed W bosons of F_+ < 0.26 at the
95% confidence level.Comment: 11 pages, 2 figures, submitted to Phys. Rev.
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