3,757 research outputs found
Measurement of the Z/γ∗ forward-backward asymmetry in muon pairs with the ATLAS experiment at the LHC
A study on muon pairs produced through an intermediate Z/γ
∗, in pp collisions at the LHC, at a center-of-mass energy of 7TeV, is presented. After a selection aimed at enhancing the contribution from Z boson decay, the topology of the events is analyzed, and the forward-backward asymmetry is measured. The result is then used to test a method to measure the effective weak mixing angle sin2 θeff W . This note summarizes the results obtained with 2011 data collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 4.8 fb−1
A Novel Ultrasound-based Measure of the Liver among Diabetes Mellitus Type II Patients
Diabetes mellitus type II (DM II) or adult onset diabetes is due to the inefficient use of insulin, which affects various organs and tissues. Patients with DM II are at risk of suffering non-alcoholic fatty liver disease (NAFLD) that can later develop into more life threating forms such as hepatomegaly, cirrhosis or liver cancer. Following the logic of the non-inferiority trial test, we aim to establish a more accurate anatomical measure of the right liver lobe (RLL) to facilitate close monitoring of liver size with ultrasound (US). We hypothesize that US is not unacceptably worse than computed tomography (CT) or magnetic resonance imaging (MRI) to accurately and reliably measure the size of the RLL when the measure is taken in the midaxillary line and craniocaudal plane (MAL-CC). Therefore, the objective of this study is to conduct a non-inferiority trial to test our novel MAL-CC measure.
To meet this aim, US measure of the RLL was taken from DM II (n=7) and non-DM II (n=5) patients, whom were recruited from 2 endocrinology clinics at SoM-UPR. Preliminary data shows that MAL-CC measure of the RLL from non-DM II patients is 13.99 + 2.53 cm whereas the same measurement among DM II patients is 15.25 + 3.25 cm (Mann-Whitney U test, p= 0.42). It is concluded that there is a non-significant trend for large RLL sizes among DM II patients. Future work aims to increase sample size and to validate our novel measurement with MRI
Apollo-Soyuz Doppler-tracking experiment MA-089
The Doppler tracking experiment was designed to test the feasibility of improved mapping of the earth's gravity field by the low-low satellite-to-satellite tracking method and to observe variations in the electron density of the ionosphere between the two spacecraft. Data were taken between 1:01 and 14:37 GMT on July 24, 1975. Baseline data taken earlier, while the docking module was still attached to the command and service module, indicated that the equipment operated satisfactorily. The ionospheric data contained in the difference between the Doppler signals at the two frequencies are of excellent quality, resulting in valuable satellite-to-satellite observations, never made before, of wave phenomena in the ionosphere. The gravity data were corrupted by an unexpectedly high noise level of as-yet-undetermined origin, with periods greater than 150 seconds, that prevented unambiguous identification of gravity-anomaly signatures
Maxillary nerve block: A comparison between the greater palatine canal and high tuberosity approaches.
Aim: Analgesia and anxiolysis during dental procedures are important for dental care and
patient compliance. This study aims to compare two classical maxillary nerve block (MNB)
techniques: the greater palatine canal (GPC) and the high tuberosity (HT) approaches,
seldom used in routine dental practice.
Methods: The study was conducted on 30 patients, scheduled for sinus lift surgery, who
were randomly divided into 2 groups: the GPC approach to the MNB was used in 15 and the
HT one in the other 15 patients. Anxiolysis was also used, depending on the results of the
pre- preoperative assessment. Patients\u2019 sensations/pain during the procedure, details about
anesthesia, and the dentist\u2019s considerations were all recorded. Data are expressed as mean
\ub1SD. Statistical tests including ANOVA, \u3c72 following Yates correction and linear regression
analysis were carried out. A < 0.05 p value was considered significant.
Results: Study results showed that the anesthesia was effective and constant in the molar
and premolar area. Additional infiltrations of local anesthetics were necessary for vestibular
and palatal areas in the anterior oral cavity, respectively, in the GPC and HT groups. The
two techniques were equally difficult to carry out in the dentist\u2019s opinion. There were
no differences in pain or unpleasant sensations between the two groups, nor were any
anesthesia-related complications reported.
Conclusion: The GPC approach ensures effective anesthesia in the posterior maxillary
region as far as both the dental pulp and the palatal/vestibular mucous membranes are
concerned; the HT approach did not guarantee adequate anesthesia of the pterygopalatine
branch of the maxillary nerve. These regional anesthesia techniques were characterized
by a low incidence of intra and postoperative pain, no noteworthy complications, and high
patient satisfaction
Shadows of Relic Neutrino Masses and Spectra on Highest Energy GZK Cosmic Rays
The Ultra High Energy (UHE) neutrino scattering onto relic cosmic neutrinos
in galactic and local halos offers an unique way to overcome GZK cut-off. The
UHE nu secondary of UHE photo-pion decays may escape the GZK cut-off and travel
on cosmic distances hitting local light relic neutrinos clustered in dark
halos. The Z resonant production and the competitive W^+W^-, ZZ pair production
define a characteristic imprint on hadronic consequent UHECR spectra. This
imprint keeps memory both of the primary UHE nu spectra as well as of the
possible relic neutrino masses values, energy spectra and relic densities. Such
an hadronic showering imprint should reflect into spectra morphology of cosmic
rays near and above GZK 10^{19}-10^{21}eV cut-off energies. A possible neutrino
degenerate masses at eVs or a more complex and significant neutrino mass split
below or near Super-Kamiokande \triangle m_{\nu_{SK}}= 0.1 eV masses might be
reflected after each corresponding Z peak showering, into new twin unexpected
UHECR flux modulation behind GZK energies: E_{p} sim 3(frac{triangle
m_{\nu_{SK}}}/m_{\nu}10^{21}),eV.
Other shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV
simeq kT_{\nu}, their lowest relic temperatures, energies and densities might
be also reflected at even higher energies edges near Grand Unification: E_{p}
\sim 2.2(m_{\nu_{2K}/E_{\nu}})10^{23}, eV .Comment: 14 pages, 6 Figures,Invited Talk Heidelberg DARK 200
Training-induced inversion of spontaneous exchange bias field on La1.5Ca0.5CoMnO6
In this work we report the synthesis and structural, electronic and magnetic
properties of La1.5Ca0.5CoMnO6 double-perovskite. This is a re-entrant spin
cluster material which exhibits a non-negligible negative exchange bias effect
when it is cooled in zero magnetic field from an unmagnetized state down to low
temperature. X-ray powder diffraction, X-ray photoelectron spectroscopy and
magnetometry results indicate mixed valence state at Co site, leading to
competing magnetic phases and uncompensated spins at the magnetic interfaces.
We compare the results for this Ca-doped material with those reported for the
resemblant compound La1.5Sr0.5CoMnO6, and discuss the much smaller spontaneous
exchange bias effect observed for the former in terms of its structural and
magnetic particularities. For La1.5Ca0.5CoMnO6, when successive magnetization
loops are carried, the spontaneous exchange bias field inverts its sign from
negative to positive from the first to the second measurement. We discuss this
behavior based on the disorder at the magnetic interfaces, related to the
presence of a glassy phase. This compound also exhibits a large conventional
exchange bias, for which there is no sign inversion of the exchange bias field
for consecutive cycles
FOXO3 on the Road to Longevity: Lessons From SNPs and Chromatin Hubs
Health span is driven by a precise interplay between genes and the environment. Cell response to environmental cues is mediated by signaling cascades and genetic variants that affect gene expression by regulating chromatin plasticity. Indeed, they can promote the interaction of promoters with regulatory elements by forming active chromatin hubs. FOXO3 encodes a transcription factor with a strong impact on aging and age-related phenotypes, as it regulates stress response, therefore affecting lifespan. A significant association has been shown between human longevity and several FOXO3 variants located in intron 2. This haplotype block forms a putative aging chromatin hub in which FOXO3 has a central role, as it modulates the physical connection and activity of neighboring genes involved in age-related processes. Here we describe the role of FOXO3 and its single-nucleotide polymorphisms (SNPs) in healthy aging, with a focus on the enhancer region encompassing the SNP rs2802292, which upregulates FOXO3 expression and can promote the activity of the aging hub in response to different stress stimuli. FOXO3 protective effect on lifespan may be due to the accessibility of this region to transcription factors promoting its expression. This could in part explain the differences in FOXO3 association with longevity between genders, as its activity in females may be modulated by estrogens through estrogen receptor response elements located in the rs2802292-encompassing region. Altogether, the molecular mechanisms described here may help establish whether the rs2802292 SNP can be taken advantage of in predictive medicine and define the potential of targeting FOXO3 for age-related diseases
Cholesterol depletion inhibits synaptic transmission and synaptic plasticity in rat hippocampus.
Several neurodegenerative disorders are associated with impaired cholesterol homeostasis in the nervous system where cholesterol is known to play a role in modulating synaptic activity and stabilizing membrane microdomains. In the present report, we investigated the effects of methyl-beta-cyclodextrin-induced cholesterol depletion on synaptic transmission and on the expression of 1) paired-pulse facilitation (PPF); 2) paired-pulse inhibition (PPI) and 3) long-term potentiation (LTP) in the CA1 hippocampal region. Results demonstrated that cyclodextrin strongly reduced synaptic transmission and blocked the expression of LTP, but did not affect PPF and PPI. The role of glutamatergic and GABAergic receptors in these cholesterol depletion-mediated effects was evaluated pharmacologically. Data indicate that, in cholesterol depleted neurons, modulation of synaptic transmission and synaptic plasticity phenomena are sustained by AMPA-, kainate-and NMDA-receptors but not by GABA-receptors. The involvement of AMPA-and kainate-receptors was confirmed by fluorimetric analysis of intracellular calcium concentrations in hippocampal cell cultures. These data suggest that modulation of receptor activity by manipulation of membrane lipids is a possible therapeutic strategy in neurodegenerative disease
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