456 research outputs found
Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior
The KamLAND and Borexino experiments have detected electron antineutrinos
produced in the decay chains of natural thorium and uranium (Th and U
geoneutrinos). We analyze the energy spectra of current geoneutrino data in
combination with solar and long-baseline reactor neutrino data, with
marginalized three-neutrino oscillation parameters. We consider the case with
unconstrained Th and U event rates in KamLAND and Borexino, as well as cases
with fewer degrees of freedom, as obtained by successively assuming for both
experiments a common Th/U ratio, a common scaling of Th+U event rates, and a
chondritic Th/U value. In combination, KamLAND and Borexino can reject the null
hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or
indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in
broad agreement with typical Earth model expectations. Conversely, the results
disfavor the hypothesis of a georeactor in the Earth's core, if its power
exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is
highlighted.Comment: 12 pages, including 6 figure
Corticosteroids in sports-related injuries: Friend or Foe
Corticosteroids act as potent anti-inflammatory drugs and have been used in various sport settings for the treatment of both acute and chronic injuries. Basic physiology and mechanisms of action for gluco- and mineralocorticoids are discussed. Methods of administration, the action on the inflammatory response, and potential short and long-term side effects of corticosteroid use are also deliberated. More specifically, corticosteroid use in the treatment and management of sport-related injuries are discussed, elucidating on the ethical boundaries and anti-doping regulations pertaining to corticosteroid use in sports, as well as putting forth suggestions for the use of local steroid injections and their contraindications. In conclusion, it was found that, despite some controversy in the use of corticosteroid treatment in the sports environment, little empirical evidence exists that could conclusively rule for or against its use. It is however clear that, if clinically justified, there is a significant role for corticosteroid treatment in the realm of sports injury and notably with a relatively low risk profile, if administered correctly.Keywords: Steroid hormones, athlete, sports, injury, inflammation
Microwave ac Zeeman Force for Ultracold Atoms
We measure the ac Zeeman force on an ultracold gas of 87Rb due to a microwave magnetic field targeted to the 6.8 GHz hyperfine splitting of these atoms. An atom chip produces a microwave near field with a strong amplitude gradient, and we observe a force over three times the strength of gravity. Our measurements are consistent with a simple two-level theory for the ac Zeeman effect and demonstrate its resonant, bipolar, and spin-dependent nature. We observe that the dressed-atom eigenstates gradually mix over time and have mapped out this behavior as a function of magnetic field and detuning. We demonstrate the practical spin selectivity of the force by pushing or pulling a specific spin state while leaving other spin states unmoved
Local treatment with electrochemotherapy of superficial angiosarcomas: Efficacy and safety results from a multi-institutional retrospective study
Background:
Angiosarcoma is an aggressive vascular neoplasm with a high propensity for local recurrence. Electrochemotherapy is an emerging
skin-directed therapy, exerting prominent cytotoxic activity, and antivascular effects. Its efficacy in angiosarcoma has not been investigated.
Methods:
This multicenter retrospective analysis reviewed patients who underwent electrochemotherapy from 2007 to 2014 for superficial
advanced angiosarcomas. Bleomycin was administered intravenously and delivered within tumors by means of percutaneously applied electric
pulses, according to the European Standard Operating Procedures for Electrochemotherapy. Tumor assessment was performed using RECIST
(version 1.1). Toxicity (CTCAE, v4.0) and local progression-free survival (LPFS) were also evaluated.
Results:
Nineteen patients (13 with locally advanced and 6 with metastatic angiosarcomas) were treated. Tumor sites were: scalp (nÂĽ5), breast(nÂĽ8), other skin sites (nÂĽ3), and soft tissue (nÂĽ3). Target lesions (nÂĽ54) ranged in size from 1.5 to 2.5 cm (median, 2 cm). Treatment was well tolerated. After 2 months, an objective response was observed in 12/19 (63%) patients, complete in 8 (42%). One-year LPFS within treatment field was 68%. Local symptom improvement included palliation of bleeding (5/19 patients) and pain relief (6/19 patients).
Conclusions:
Electrochemotherapy may represent a new locoregional treatment for selected patients with superficial angiosarcomas
Hints of theta_13>0 from global neutrino data analysis
Nailing down the unknown neutrino mixing angle theta_13 is one of the most
important goals in current lepton physics. In this context, we perform a global
analysis of neutrino oscillation data, focusing on theta_13, and including
recent results [Neutrino 2008, Proceedings of the XXIII International
Conference on Neutrino Physics and Astrophysics, Christchurch, New Zealand,
2008 (unpublished)]. We discuss two converging hints of theta_13>0, each at the
level of ~1sigma: an older one coming from atmospheric neutrino data, and a
newer one coming from the combination of solar and long-baseline reactor
neutrino data. Their combination provides the global estimate sin^2(theta_13) =
0.016 +- 0.010 (1sigma), implying a preference for \theta_13>0 with
non-negligible statistical significance (~90% C.L.). We discuss possible
refinements of the experimental data analyses, which might sharpen such
intriguing indication.Comment: Minor changes in the text. Matches published version in PR
Golden Ratio Prediction for Solar Neutrino Mixing
It has recently been speculated that the solar neutrino mixing angle is
connected to the golden ratio phi. Two such proposals have been made, cot
theta_{12} = phi and cos theta_{12} = phi/2. We compare these Ansatze and
discuss a model leading to cos theta_{12} = phi/2 based on the dihedral group
D_{10}. This symmetry is a natural candidate because the angle in the
expression cos theta_{12} = phi/2 is simply pi/5, or 36 degrees. This is the
exterior angle of a decagon and D_{10} is its rotational symmetry group. We
also estimate radiative corrections to the golden ratio predictions.Comment: 15 pages, 1 figure. Matches published versio
Geo-neutrinos: A systematic approach to uncertainties and correlations
Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a
unique probe of the Earth interior. The characterization of their fluxes is
subject, however, to rather large and highly correlated uncertainties. The
geochemical covariance of the U, Th and K abundances in various Earth
reservoirs induces positive correlations among the associated geo-neutrino
fluxes, and between these and the radiogenic heat. Mass-balance constraints in
the Bulk Silicate Earth (BSE) tend instead to anti-correlate the radiogenic
element abundances in complementary reservoirs. Experimental geo-neutrino
observables may be further (anti)correlated by instrumental effects. In this
context, we propose a systematic approach to covariance matrices, based on the
fact that all the relevant geo-neutrino observables and constraints can be
expressed as linear functions of the U, Th and K abundances in the Earth's
reservoirs (with relatively well-known coefficients). We briefly discuss here
the construction of a tentative "geo-neutrino source model" (GNSM) for the U,
Th, and K abundances in the main Earth reservoirs, based on selected
geophysical and geochemical data and models (when available), on plausible
hypotheses (when possible), and admittedly on arbitrary assumptions (when
unavoidable). We use then the GNSM to make predictions about several
experiments ("forward approach"), and to show how future data can constrain - a
posteriori - the error matrix of the model itself ("backward approach"). The
method may provide a useful statistical framework for evaluating the impact and
the global consistency of prospective geo-neutrino measurements and Earth
models.Comment: 17 pages, including 4 figures. To appear on "Earth, Moon, and
Planets," Special Issue on "Neutrino Geophysics," Proceedings of Neutrino
Science 2005 (Honolulu, Hawaii, Dec. 2005
Transcriptomic and genomic structural variation analyses on grape cultivars reveal new insights into the genotype-dependent responses to water stress
Grapevine (Vitis vinifera L.) is importantly cultivated worldwide for table grape and wine production. Its cultivation requires irrigation supply, especially in arid and semiarid areas. Water deficiency can affect berry and wine quality mostly depending on the extent of plant perceived stress, which is a cultivar-specific trait. We tested the physiological and molecular responses to water deficiency of two table grape cultivars, Italia and Autumn royal, and we highlighted their different adaptation. Microarray analyses revealed that Autumn royal reacts involving only 29 genes, related to plant stress response and ABA/hormone signal transduction, to modulate the response to water deficit. Instead, cultivar Italia orchestrates a very broad response (we found 1037 differentially expressed genes) that modifies the cell wall organization, carbohydrate metabolism, response to reactive oxygen species, hormones and osmotic stress. For the first time, we integrated transcriptomic data with cultivar-specific genomics and found that ABA-perception and –signalling are key factors mediating the varietal-specific behaviour of the early response to drought. We were thus able to isolate candidate genes for the genotype-dependent response to drought. These insights will allow the identification of reliable plant stress indicators and the definition of sustainable cultivar-specific protocols for water management
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