4,665 research outputs found
Joint short- and long-baseline constraints on light sterile neutrinos
Recent studies provide evidence that long-baseline (LBL) experiments are sensitive to the extra CP phases involved with light sterile neutrinos, whose existence is suggested by several anomalous short-baseline (SBL) results. We show that, within the 3+1 scheme, the combination of the existing SBL data with the LBL results coming from the two currently running experiments, NO\u3bdA and T2K, enables us to simultaneously constrain two active-sterile mixing angles, \u3b814 and \u3b824, and two CP phases, \u3b413 61\u3b4 and \u3b414, although the information on the second CP phase is still weak. The two mixing angles are basically determined by the SBL data, while the two CP phases are constrained by the LBL experiments, once the information coming from the SBL setups is taken into account. We also assess the robustness or fragility of the estimates of the standard 3-flavor parameters in the more general 3+1 scheme. To this regard we find that (i) the indication of CP violation found in the 3-flavor analyses persists also in the 3+1 scheme, with \u3b413 61\u3b4 having still its best-fit value around 12\u3c0/2, (ii) the 3-flavor weak hint in favor of the normal hierarchy becomes even less significant when sterile neutrinos come into play, (iii) the weak indication of nonmaximal \u3b823 (driven by NO\u3bdA disappearance data) persists in the 3+1 scheme, where maximal mixing is disfavored at almost the 90% C.L. in both normal and inverted mass hierarchy, and (iv) the preference in favor of one of the two octants of \u3b823 found in the 3-flavor framework (higher octant for inverted mass hierarchy) is completely washed out in the 3+1 scheme
Neutrino masses and mixings: Status of known and unknown parameters
Within the standard 3nu mass-mixing framework, we present an up-to-date
global analysis of neutrino oscillation data (as of January 2016), including
the latest available results from experiments with atmospheric neutrinos
(Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K anti-nu and
NOvA nu runs in both appearance and disappearance mode), and at short-baseline
reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis
of older KamLAND data in the light of the "bump" feature recently observed in
reactor spectra. We discuss improved constraints on the five known oscillation
parameters (delta m^2, |Delta m^2|, sin^2theta_12, sin^2theta_13,
sin^2theta_23), and the status of the three remaining unknown parameters: the
mass hierarchy, the theta_23 octant, and the possible CP-violating phase delta.
With respect to previous global fits, we find that the reanalysis of KamLAND
data induces a slight decrease of both delta m^2 and sin^2theta_12, while the
latest accelerator and atmospheric data induce a slight increase of |Delta
m^2|. Concerning the unknown parameters, we confirm the previous intriguing
preference for negative values of sin(delta) [with best-fit values around
sin(delta) ~ -0.9], but we find no statistically significant indication about
the theta_23 octant or the mass hierarchy (normal or inverted). Assuming an
alternative (so-called LEM) analysis of NOvA data, some delta ranges can be
excluded at >3 sigma, and the normal mass hierarchy appears to be slightly
favored at 90% C.L. We also describe in detail the covariances of selected
pairs of oscillation parameters. Finally, we briefly discuss the implications
of the above results on the three non-oscillation observables sensitive to the
(unknown) absolute nu mass scale: the sum of nu masses, the effective nu_e
mass, and the effective Majorana mass.Comment: 15 pages, 9 figures, 2 tables. Invited contribution prepared for the
Nuclear Physics B Special Issue on "Neutrino Oscillations" celebrating the
Nobel Prize in Physics 201
Status of three-neutrino oscillation parameters, circa 2013
The standard three-neutrino (3nu) oscillation framework is being increasingly
refined by results coming from different sets of experiments, using neutrinos
from solar, atmospheric, accelerator and reactor sources. At present, each of
the known oscillation parameters [the two squared mass gaps (delta m^2, Delta
m^2) and the three mixing angles (theta_12}, theta_13, theta_23)] is dominantly
determined by a single class of experiments. Conversely, the unknown parameters
[the mass hierarchy, the theta_23 octant and the CP-violating phase delta] can
be currently constrained only through a combined analysis of various
(eventually all) classes of experiments. In the light of recent new results
coming from reactor and accelerator experiments, and of their interplay with
solar and atmospheric data, we update the estimated N-sigma ranges of the known
3nu parameters, and revisit the status of the unknown ones. Concerning the
hierarchy, no significant difference emerges between normal and inverted mass
ordering. A slight overall preference is found for theta_23 in the first octant
and for nonzero CP violation with sin delta < 0; however, for both parameters,
such preference exceeds 1 sigma only for normal hierarchy. We also discuss the
correlations and stability of the oscillation parameters within different
combinations of data sets.Comment: Updated and revised version, accepted for publication in PRD. The
analysis includes the latest (March 2014) T2K disappearance data: all the
figures and the numerical results have been updated, and parts of the text
have been revised accordingl
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
Theoretical and experimental analysis of dissipative buckling restrained barces
Buckling restrained braces are passive energy dissipators used for seismic protection of building
frames; such devices consist of slender steel bars connected usually to the frame to be protected
either like conventional (concentric) diagonal braces or like chevron braces. Under horizontal
seismic motions, the interstory drifts generate axial strains in the steel bars beyond their yielding
points; such tension-compression cycles constitute the hysteresis loops. The buckling of the steel
bars (core) is prevented by embedding them in a stockiest encasing; it consists usually of a steel
tube filled with mortar. A crucial issue is to allow sliding between the core and the encasing to
prevent relevant shear stress transfer.
This work aims to contribute to a better understanding of the behavior of buckling restrained
braces; the final objective is to foster its mass use in developing countries (in earthquake prone
regions), particularly for reinforced concrete building frames. The research approach consists of
designing, producing and testing (in Argentina) five reduced scale dissipators (about 400 mm
long) and of taking profit of the gained experience to design, to produce and to test (in Spain) four
full size (near 3000 mm long) prototype devices. All these tests are individual, i.e. no
subassemblies (accounting for the building frames) are considered.
The main conclusion is that it is possible to obtain a reasonably cheap (about 1000 US$ per unit;
this amount corresponds to production in Spain (summer 2006) without optimizing the
fabrication process), efficient, robust, low maintenance and durable prototype device requiring
only a low-tech production process (suitable for developing countries). Moreover, the results
show that the fatigue life of buckling restrained braces, even highly uncertain, can be significantly
bigger than expected (according to some previously published results); it might allow extending
the life of these devices after a number of strong seismic inputs.
A numerical analysis of the buckling behavior of these devices is performed; it allows
formulating some design recommendations. Further research needs are identified
The effect of Laurus nobilis on the blood and lenses antioxidant activity in rabbit under fat-enriched diet
Fat-enriched diet is strongly associated with cataract development. Laurus nobilis shows antioxidant activity. Herein we evaluated the effect of Laurus nobilis oral administration on the blood and lenses antioxidant activity in rabbits under fat-enriched diet. Sixty rabbits divided into 4 groups were used. One group represented the control (N-CTR). The second group (P-CTR) fed a diet supplemented with 2.5 % of pig fat; the third group (EXP1) received a diet supplemented with 2.5 % of pig fat and 1 g/kg of dried-bay leaves; the fourth group (EXP2) was treated with dried-bay leaves at the rate of 1 g/kg of feed. At baseline and at the end of the study (56 days) the following blood parameters were determined: thiobarbituric acid reactive substances (TBARS), reactive oxygen metabolites (ROMs), total phenols, superoxide dismutase (SOD), oxygen radical absorbance capacity (ORACpca), ferric ion reducing antioxidant power (FRAP), retinol and alfa-tocopherol. At the end of the follow-up, the eyes were enucleated and the antioxidant profile, such as total antioxidant activity (TAC), TBARS, retinol and alfa-tocopherol of lenses was evaluated. Plasma ROMs and TBARS levels were statistically lower in the groups receiving bay leaves integration. A significant increase of plasma retinol, FRAP and ORACpca levels was found in EXP1 and EXP2 groups, whereas plasma alfa-tocopherol resulted statistically higher only in EXP2 group. Bay leaves supplementation enhanced TAC, retinol and alfa-tocopherol in rabbit lens, particularly in EXP2 group; whereas lenses TBARS levels significantly decreased in both treated groups. These findings demonstrate that Laurus nobilis oral administration exerts a protective effect on the risk of cataract development in rabbits under fat-enriched diet
the effect of laurus nobilis on the blood and lenses antioxidant activity in rabbit under fat enriched diet
Fat-enriched diet is strongly associated with cataract development. Laurus nobilis shows antioxidant activity. Herein we evaluated the effect of Laurus nobilis oral administration on the blood and lenses antioxidant activity in rabbits under fat-enriched diet. Sixty rabbits divided into 4 groups were used. One group represented the control (N-CTR). The second group (P-CTR) fed a diet supplemented with 2.5 % of pig fat; the third group (EXP1) received a diet supplemented with 2.5 % of pig fat and 1 g/kg of dried-bay leaves; the fourth group (EXP2) was treated with dried-bay leaves at the rate of 1 g/kg of feed. At baseline and at the end of the study (56 days) the following blood parameters were determined: thiobarbituric acid reactive substances (TBARS), reactive oxygen metabolites (ROMs), total phenols, superoxide dismutase (SOD), oxygen radical absorbance capacity (ORACpca), ferric ion reducing antioxidant power (FRAP), retinol and alfa-tocopherol. At the end of the follow-up, the eyes were enucleated and the antioxidant profile, such as total antioxidant activity (TAC), TBARS, retinol and alfa-tocopherol of lenses was evaluated. Plasma ROMs and TBARS levels were statistically lower in the groups receiving bay leaves integration. A significant increase of plasma retinol, FRAP and ORACpca levels was found in EXP1 and EXP2 groups, whereas plasma alfa-tocopherol resulted statistically higher only in EXP2 group. Bay leaves supplementation enhanced TAC, retinol and alfa-tocopherol in rabbit lens, particularly in EXP2 group; whereas lenses TBARS levels significantly decreased in both treated groups. These findings demonstrate that Laurus nobilis oral administration exerts a protective effect on the risk of cataract development in rabbits under fat-enriched diet
Current unknowns in the three-neutrino framework
We present an up-to-date global analysis of data coming from neutrino oscillation and non-oscillation experiments, as available in April 2018, within the standard framework including three massive and mixed neutrinos. We discuss in detail the status of the three-neutrino (3ν) mass-mixing parameters, both known and unknown. Concerning the latter, we find that: normal ordering (NO) is favored over inverted ordering (IO) at 3σ level; the Dirac CP phase is constrained within ∼15% (∼9%) uncertainty in NO (IO) around nearly-maximal CP-violating values; the octant of the largest mixing angle and the absolute neutrino masses remain undetermined. We briefly comment on other unknowns related to theoretical and experimental uncertainties (within 3ν) or possible new states and interactions (beyond 3ν)
The effect of water-restriction on various physiological variables in intensively reared Lacaune ewes
The effects of water restriction on rectal temperature, respiratory rate and selected blood variables in intensively reared Lacaune ewes were evaluated. The tests were carried out over the course of 28 days in spring on 30 lactating sheep divided into three groups of 10 animals each, matched by lactation status and body weight and allocated into individual boxes. The animal groups were as follows: control group W100 with drinking water for the whole day (24 h/24 h), while the two experimental groups each received 80% (W80 group) and 60% (W60 group) of the water ration of the control group, respectively. The feed, in according with physiological and production needs of the animals, was administered in three daily meals (08:00, 14:00 and 20:00 h). Water intake was recorded three times per day (at 08:00, 14:00 and 20:00 h) and the daily feed intake at 08:00 h, while the rectal temperature, respiratory rate were measured and blood samplings were carried out on Day 0, Day 14 and Day 28. In water-restriction groups (W80 and W60) a lower (P < 0.01) feed intake of meadow hay, and a lower ingestion of alfalfa hay pellet in the W60 group compared to W100 group were observed. In addition, the water restriction regimen resulted in a significant decrease of respiratory rate (P < 0.05) and an increase in serum total protein, urea, creatinine, sodium, chlorine, reactive oxygen metabolites, cortisol, haemoglobin and mean corpuscular haemoglobin concentration (P < 0.05), red blood cell counts, and haematocrit (P < 0.01). These results show the important role of water, as limiting factor for animal breeding in low-water availability environments. Where possible, the management of low-dairy breeds should be well adapted to support the productive performance
p180 Promotes the Ribosome-Independent Localization of a Subset of mRNA to the Endoplasmic Reticulum
The localization of many secretory mRNAs to the endoplasmic reticulum does not require ribosomes or translation, but is instead promoted by p180, an abundant, membrane-bound protein that likely binds directly to mRNA
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