6,548 research outputs found
Quark-gluon tagging: Application to the search of the Higgs boson in the ATLAS experiment at LHC
The possibility to discriminate between events with jets coming from quarks or gluons (quark-gluon tagging) can constitute a new tool to improve the sensitivity of some particular analyses. This study presents the implementation
of a discriminant to be used in quark-gluon tagging based upon neural networks without supervision, the so-called Self Organizing Maps (SOM). This method has been applied on the search for production of a particle that decays in a couple of Z bosons, with two leptons and two jets in its final state, using data recorded by the ATLAS experiment
Gene Silencing of \u3ci\u3eArgonaute5\u3c/i\u3e Negatively Affects the Establishment of the Legume-Rhizobia Symbiosis
The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also report that the expression of AGO5 is induced after 1 h of inoculation with rhizobia. Down-regulation of AGO5 gene in P. vulgaris and G. max causes diminished root hair curling, reduces nodule formation and interferes with the induction of three critical symbiotic genes: Nuclear Factor Y-B (NF-YB), Nodule Inception (NIN) and Flotillin2 (FLOT2). Our findings provide evidence that the common bean and soybean AGO5 genes play an essential role in the establishment of the symbiosis with rhizobia
High-Dose vs. Low-Dose Dexamethasone in Patients With COVID-19: A Cohort Study in Rural Central America
To compare the clinical outcomes of a low dose dexamethasone strategy vs. a high-dose dexamethasone strategy in hypoxemic COVID-19 patients. A retrospective observational study comparing low-dose (8 mg) and high-dose dexamethasone (24 mg) of COVID-19 patients admitted from September 1, 2020 to October 31, 2020 in a hospital in Honduras. We included 81 patients with confirmed COVID-19 who required oxygen therapy. The mean age was similar between groups (57.49 vs. 56.95 years). There were more male patients in the group of 24 mg (p = 0.01). Besides, patients on the 24 mg dose had more prevalence of hypertension (p = 0.052). More patients in the 24 mg group had a higher rate of invasive mechanical ventilation (15.00% vs. 2.56%, p = 0.058). When evaluating the association between the high dose group and outcomes, we find no significant association with mortality, nosocomial infections, high flow mask, invasive mechanical ventilation, or the need for vasopressors. We find no significant differences in the Kaplan–Meier analysis regarding the survival (log-rank p-value = 0.315). We did not find significant differences between the use of 24 mg and 8 mg of dexamethasone in hypoxemic COVID-19 patients.Revisión por pare
Two-loop Corrections to the B to pi Form Factor from QCD Sum Rules on the Light-Cone and |V(ub)|
We calculate the leading-twist O(alphas^2 beta0) corrections to the B to pi
transition form factor f+(0) in light-cone sum rules. We find that, as
expected, there is a cancellation between the O(alphas^2 beta0) corrections to
fB f+(0) and the large corresponding corrections to fB, calculated in QCD sum
rules. This suggests the insensitivity of the form factors calculated in the
light-cone sum rules approach to this source of radiative corrections. We
further obtain an improved determination of the CKM matrix element |V(ub)|,
using latest results from BaBar and Belle for f+(0)|V(ub)|.Comment: 18 pages, 3 figure
Gender Inequalities in Diagnostic Inertia around the Three Most Prevalent Cardiovascular Risk Studies: Protocol for a Population-Based Cohort Study
Evidence shows that objectives for detecting and controlling cardiovascular risk factors are not being effectively met, and moreover, outcomes differ between men and women. This study will assess the gender-related differences in diagnostic inertia around the three most prevalent cardiovascular risk factors: dyslipidemia, arterial hypertension, and diabetes mellitus, and to evaluate the consequences on cardiovascular disease incidence. This is an epidemiological and cohort study. Eligible patients will be adults who presented to public primary health care centers in a Spanish region from 2008 to 2011, with hypertension, dyslipidemia, or/and diabetes and without cardiovascular disease. Participants’ electronic health records will be used to collect the study variables in a window of six months from inclusion. Diagnostic inertia of hypertension, dyslipidemia, and/or diabetes is defined as the registry of abnormal diagnostic parameters—but no diagnosis—on the person’s health record. The cohort will be followed from the date of inclusion until the end of 2019. Outcomes will be cardiovascular events, defined as hospital admission due to ischemic cardiopathy, stroke, and death from any cause. The results of this study could inform actions to rectify the structure, organization and training of health care teams in order to correct the inequality
Taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism
Objective: To evaluate the taxonomic composition of the gut microbiome in gout patients with and without tophi
formation, and predict bacterial functions that might have an impact on urate metabolism.
Methods: Hypervariable V3–V4 regions of the bacterial 16S rRNA gene from fecal samples of gout patients with
and without tophi (n=33 and n=25, respectively) were sequenced and compared to fecal samples from 53 healthy
controls. We explored predictive functional profles using bioinformatics in order to identify diferences in taxonomy
and metabolic pathways.
Results: We identifed a microbiome characterized by the lowest richness and a higher abundance of Phascolarctobacterium, Bacteroides, Akkermansia, and Ruminococcus_gnavus_group genera in patients with gout without tophi
when compared to controls. The Proteobacteria phylum and the Escherichia-Shigella genus were more abundant
in patients with tophaceous gout than in controls. Fold change analysis detected nine genera enriched in healthy
controls compared to gout groups (Bifdobacterium, Butyricicoccus, Oscillobacter, Ruminococcaceae_UCG_010, Lachnospiraceae_ND2007_group, Haemophilus, Ruminococcus_1, Clostridium_sensu_stricto_1, and Ruminococcaceae_
UGC_013). We found that the core microbiota of both gout groups shared Bacteroides caccae, Bacteroides stercoris ATCC
43183, and Bacteroides coprocola DSM 17136. These bacteria might perform functions linked to one-carbon metabo‑
lism, nucleotide binding, amino acid biosynthesis, and purine biosynthesis. Finally, we observed diferences in key
bacterial enzymes involved in urate synthesis, degradation, and elimination.
Conclusion: Our fndings revealed that taxonomic variations in the gut microbiome of gout patients with and with‑
out tophi might have a functional impact on urate metabolism.
Keywords: Gout, Gut microbiota, Uric acid metabolis
The CARMA-NRO Orion Survey:The filamentary structure as seen in C18O emission
We present an initial overview of the filamentary structure in the Orion A
molecular cloud utilizing a high angular and velocity resolution CO(1-0)
emission map that was recently produced as part of the CARMA-NRO Orion Survey.
The main goal of this study is to build a credible method to study varying
widths of filaments which has previously been linked to star formation in
molecular clouds. Due to the diverse star forming activities taking place
throughout its 20 pc length, together with its proximity of 388 pc, the
Orion A molecular cloud provides an excellent laboratory for such an experiment
to be carried out with high resolution and high sensitivity. Using the
widely-known structure identification algorithm, DisPerSE, on a 3-dimensional
(PPV) CO cube, we identified 625 relatively short (the longest being
1.74 pc) filaments over the entire cloud. We study the distribution of filament
widths using FilChaP, a python package that we have developed and made publicly
available. We find that the filaments identified in a 2 square degree PPV cube
do not overlap spatially, except for the complex OMC-4 region that shows
distinct velocity components along the line of sight. The filament widths vary
between 0.02 and 0.3 pc depending on the amount of substructure that a filament
possesses. The more substructure a filament has, the larger is its width. We
also find that despite this variation, the filament width shows no
anticorrelation with the central column density which is in agreement with
previous Herschel observations.Comment: 19 pages, 20 figures. Accepted for publication in Astronomy and
Astrophysic
Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.
Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification
Effect of tapentadol on neurons in the locus coeruleus
Tapentadol is a novel centrally acting drug that combines mu-opioid receptor (MOR) agonism and
noradrenaline reuptake inhibition (NRI), producing analgesic effects in various painful conditions. We
investigated the acute effects of tapentadol in the locus coeruleus (LC), a central nucleus regulated by the
noradrenergic and opioid systems that is critical in pain modulation. In single-unit extracellular recordings
of LC neurons from anaesthetized male SpragueeDawley rats, tapentadol clearly inhibited the
spontaneous electrophysiological activity of LC neurons in a dose-dependent manner (ED50 ¼ 0.8 mg/kg).
This inhibitory effect was reversed by RX821002 (an alpha2-adrenoceptor antagonist) and naloxone (a
mu-opioid receptor antagonist) by 96.7% and 28.2%, respectively. Pretreatment with RX821002, Nethoxycarbonyl-
2-ethoxy-1-2-dihydroquinoline (EEDQ, an irreversible alpha2-adrenoceptor antagonist)
or naloxone shifted the tapentadol doseeeffect curve to the right (ED50 ¼ 2.2 mg/kg, 2.0 mg/kg and
2.1 mg/kg, respectively). Furthermore, tapentadol inhibited the LC response to mechanical stimulation of
the hindpaw in a dose-dependent manner. In summary, we demonstrate that acute administration of
tapentadol inhibits LC neurons in vivo, mainly due to the activation of alpha2-adrenoceptors. These data
suggest that both the noradrenergic and opioid systems participate in the inhibitory effect of tapentadol
on LC neurons, albeit to different extents, which may account for its potent analgesic effect and mild
opioidergic side-effects.This study was supported by grants from Grünenthal GmbH
(OT2010/075); “Fondo de Investigación Sanitaria” (PI10/01221 and
PI12/00915); CIBERSAM (G18); Junta de Andalucía, Consejería de
Innovación, Ciencia y Empresa (CTS-510, CTS-4303 and CTS-7748);
Cátedra Externa del Dolor Grünenthal-Universidad de Cádiz;
FP7-PEOPLE-2010-RG (268377); FPU (AP2007-02397) and FPI
(2011-145) fellowship
Overexpression. of dehydrin tas14 gene improves the osmotic stress imposed by drought and salinity in tomato
[EN] One strategy to increase the level of drought and salinity tolerance is the transfer of genes codifying different types of proteins functionally related to macromolecules protection, such as group 2 of late embryogenesis abundant (LEA) proteins or dehydrins. The TAS14 dehydrin was isolated and characterized in tomato and its expression was induced by osmotic stress (NaCl and mannitol) and abscisic acid (ABA) [Godoy et al., Plant Mol Biol 1994;26:1921-1934], yet its function in drought and salinity tolerance of tomato remains elusive. In this study, transgenic tomato plants overexpressing tas14 gene under the control of the 35SCaMV promoter were generated to assess the function of tas14 gene in drought and salinity tolerance. The plants overexpressing tas14 gene achieved improved long-term drought and salinity tolerance without affecting plant growth under non-stress conditions. A mechanism of osmotic stress tolerance via osmotic potential reduction and solutes accumulation, such as sugars and K+ is operating in tas14 overexpressing plants in drought conditions. A similar mechanism of osmotic stress tolerance was observed under salinity. Moreover, the overexpression of tas14 gene increased Na+ accumulation only in adult leaves, whereas in young leaves, the accumulated solutes were K+ and sugars, suggesting that plants overexpressing tas14 gene are able to distribute the Na+ accumulation between young and adult leaves over a prolonged period in stressful conditions. Measurement of ABA showed that the action mechanism of tas14 gene is associated with an earlier and greater accumulation of ABA in leaves during short-term periods. A good feature for the application of this gene in improving drought and salt stress tolerance is the fact that its constitutive expression does not affect plant growth under non-stress conditions, and tolerance induced by overexpression of tas14 gene was observed at the different stress degrees applied to the long term. (C) 2011 Elsevier GmbH. All rights reserved.This work was supported by the Spanish Ministry of Science and Innovation through grant AGL2009-13388-C03 and by the Council of Science and Technology from the Region of Murcia (Spain) (Fundacion SENECA) through grant 04553/GERM/06.Muñoz Mayor, A.; Pineda Chaza, BJ.; García Abellán, JO.; Antón Martínez, MT.; García Sogo, B.; Sánchez Bel, P.; Flores, FB.... (2012). Overexpression. of dehydrin tas14 gene improves the osmotic stress imposed by drought and salinity in tomato. Journal of Plant Physiology. 169(5):459-468. https://doi.org/10.1016/j.jplph.2011.11.018S459468169
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