1,263 research outputs found
DBI Galileon inflation in the light of Planck 2015
In this work we consider a DBI Galileon (DBIG) inflationary model and
constrain its parameter space with the Planck 2015 and BICEP2/Keck array and
Planck (BKP) joint analysis data by means of a potential independent analysis.
We focus our attention on inflationary solutions characterized by a constant or
varying sound speed as well as warp factor. We impose bounds on stringy aspects
of the model, such as the warp factor and the induced gravity
parameter . We study the parameter space of the model
and find that the tensor-to-scalar ratio can be as low as
and inflation happens to be at GUT scale. In addition,
we obtain the tilt of the tensor power spectrum and test the standard
inflationary consistency relation against the latest
bounds from the combined results of BKP+Laser Interferometer
Gravitational-Waves Observatory (LIGO), and find that DBIG inflation predicts a
red spectral index for the tensor power spectrum.Comment: Version accepted in JCAP. 25 pages, 10 figures, new refs adde
Calculating error bars for neutrino mixing parameters
One goal of contemporary particle physics is to determine the mixing angles
and mass-squared differences that constitute the phenomenological constants
that describe neutrino oscillations. Of great interest are not only the best
fit values of these constants but also their errors. Some of the neutrino
oscillation data is statistically poor and cannot be treated by normal
(Gaussian) statistics. To extract confidence intervals when the statistics are
not normal, one should not utilize the value for chisquare versus confidence
level taken from normal statistics. Instead, we propose that one should use the
normalized likelihood function as a probability distribution; the relationship
between the correct chisquare and a given confidence level can be computed by
integrating over the likelihood function. This allows for a definition of
confidence level independent of the functional form of the !2 function; it is
particularly useful for cases in which the minimum of the !2 function is near a
boundary. We present two pedagogic examples and find that the proposed method
yields confidence intervals that can differ significantly from those obtained
by using the value of chisquare from normal statistics. For example, we find
that for the first data release of the T2K experiment the probability that
chisquare is not zero, as defined by the maximum confidence level at which the
value of zero is not allowed, is 92%. Using the value of chisquare at zero and
assigning a confidence level from normal statistics, a common practice, gives
the over estimation of 99.5%.Comment: 9 pages, 6 figure
H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability
We report 138 spectral observations of the H-alpha emission line of the
radio- and gamma-ray-emitting Be/X-ray binary LSI+61303 obtained during the
period of September 1998 -- January 2013. From measuring various H-alpha
parameters, we found that the orbital modulation of the H-alpha is best visible
in the equivalent width ratio EW(B)/EW(R), the equivalent width of the blue
hump, and in the radial velocity of the central dip. The periodogram analysis
confirmed that the H-alpha emission is modulated with the orbital and
superorbital periods. For the past 20 years the radius of the circumstellar
disk is similar to the Roche lobe size at the periastron. It is probably
truncated by a 6:1 resonance. The orbital maximum of the equivalent width of
H-alpha emission peaks after the periastron and coincides on average with the
X-ray and gamma-ray maxima. All the spectra are available upon request from the
authors and through the CDS.Comment: 11 pages, accepted for publication in A&
BIOMECHANICAL ANALYSIS OF THE DEADLIFT DURING THE 1999 SPECIAL OLYMPICS WORLD GAMES
Sumo and conventional deadlifts and high and low skilled lifters were compared during the 1999 Special Olympics World Games. Two video cameras collected 60 Hz data from 40 subjects, and parameters were quantified at barbell liftoff (LO) and barbell knee passing (KP). The sumo group had a more vertical trunk and horizontal thigh at LO, a less vertical shank at KP, and greater forefoot abduction. The sumo group generated ankle dorsiflexor, knee extensor, and hip extensor moments, while the conventional group produced ankle plantar flexor, knee flexor & extensor, and hip extensor moments. High skilled lifters had a 40% greater barbell load, greater knee flexion at LO and greater knee extension at KP, 15% less vertical bar distance, smaller plantar flexor and hip extensor moment arms at LO and KP, and greater knee extensor moment arms at LO
When are females dominant over males in rats (Rattus norvegicus)?
Funding was provided to MAP-E (scholarship program 783â2017 of the Ministry of Science, Technology and Innovation â Minciencias, formerly Colciencias), and to CKH (Lucie Burgers Foundation grant, for the research project titled âSex and competitive dynamics in groups of rats: is there resemblance to primates?â).In group-living animals, males are assumed to be dominant over females when they are larger than females. Despite this, females have sometimes been proven to be dominant over some males possibly via the winner-loser effect, which becomes clearer when the intensity of aggression in the group is higher. To test whether the winner-loser effect can lead to (partial) female dominance in a species with a pronounced sexual dimorphism, we studied the hierarchy in 12 rat colonies (Rattus norvegicus) in which the rats could freely interact with their group members within a spacious area. To investigate the underlying mechanisms, we compared the empirical data to hypotheses generated by the agent-based model âDomWorldâ. We show that females dominated on average 55% of the males, and occupied the alpha position in four colonies, in three of them they shared it with one or several males. Moreover, in line with the predictions of the computational model, females dominated a higher percentage of males when the intensity of aggression of the colony was higher. This shows that although females are only half as heavy as males, they dominate part of the males probably through the winner-loser effect. We suggest that this effect may be widespread in many other species and can be tested experimentally.Peer reviewe
Neutrino Oscillations: Hierarchy Question
The only experimentally observed phenomenon that lies outside the standard
model of the electroweak interaction is neutrino oscillations. A way to try to
unify the extensive neutrino oscillation data is to add a phenomenological mass
term to the Lagrangian that is not diagonal in the flavor basis. The goal is
then to understand the world's data in terms of the parameters of the mixing
matrix and the differences between the squares of the masses of the neutrinos.
An outstanding question is what is the correct ordering of the masses, the
hierarchy question. We point out a broken symmetry relevant to this question,
the symmetry of the simultaneous interchange of hierarchy and the sign of
. We first present the results of an analysis of data that well
determine the phenomenological parameters but are not sensitive to the
hierarchy. We find , and
eV, results consistent with others. We then include data that are sensitive
to the hierarchy and the sign of . We find, unlike others, four
isolated minimum in the -space as predicted by the symmetry. Now that
Daya Bay and RENO have determined to be surprisingly large, the
Super-K atmospheric data produce meaningful symmetry breaking such that the
inverse hierarchy is preferred at the 97.2 % level.Comment: to appear in Proceedings of the 5th International Conference on
Fission and Neutron Rich Nuclei (ICFN5), (Sanibel Island, Florina, Nov. 4-10,
2012).10 pages, 8 figure
Variable order Mittag-Leffler fractional operators on isolated time scales and application to the calculus of variations
We introduce new fractional operators of variable order on isolated time
scales with Mittag-Leffler kernels. This allows a general formulation of a
class of fractional variational problems involving variable-order difference
operators. Main results give fractional integration by parts formulas and
necessary optimality conditions of Euler-Lagrange type.Comment: This is a preprint of a paper whose final and definite form is with
Springe
Evaluation of sperm DNA quality in men presenting with testicular cancer and lymphoma using alkaline and neutral Comet assays
Genome-Wide Association Studies of Schizophrenia and Bipolar Disorder in a Diverse Cohort of US Veterans
Background: Schizophrenia (SCZ) and bipolar disorder (BIP) are debilitating neuropsychiatric disorders, collectively affecting 2% of the world\u27s population. Recognizing the major impact of these psychiatric disorders on the psychosocial function of more than 200 000 US Veterans, the Department of Veterans Affairs (VA) recently completed genotyping of more than 8000 veterans with SCZ and BIP in the Cooperative Studies Program (CSP) #572.
Methods: We performed genome-wide association studies (GWAS) in CSP #572 and benchmarked the predictive value of polygenic risk scores (PRS) constructed from published findings. We combined our results with available summary statistics from several recent GWAS, realizing the largest and most diverse studies of these disorders to date.
Results: Our primary GWAS uncovered new associations between CHD7 variants and SCZ, and novel BIP associations with variants in Sortilin Related VPS10 Domain Containing Receptor 3 (SORCS3) and downstream of PCDH11X. Combining our results with published summary statistics for SCZ yielded 39 novel susceptibility loci including CRHR1, and we identified 10 additional findings for BIP (28 326 cases and 90 570 controls). PRS trained on published GWAS were significantly associated with case-control status among European American (P \u3c 10-30) and African American (P \u3c .0005) participants in CSP #572.
Conclusions: We have demonstrated that published findings for SCZ and BIP are robustly generalizable to a diverse cohort of US veterans. Leveraging available summary statistics from GWAS of global populations, we report 52 new susceptibility loci and improved fine-mapping resolution for dozens of previously reported associations
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