1,377 research outputs found
Weighing Medical Judgments: Explaining Evidentiary Preferences for Treating Physician Opinions in ERISA Cases after Black & Decker Disability Plan v. Nord
Weighing Medical Judgments: Explaining Evidentiary Preferences for Treating Physician Opinions in ERISA Cases after Black & Decker Disability Plan v. Nord
Inversion of low-frequency subsurface data in a finite-depth ocean
AbstractLet:[▿2+k2+k2v(x)]u=−δ(x−y) in L=R2 × [0,h],u= 0 at x3 = 0, ux3 = 0 at x3 = h, u(x,y,k) satisfies the limiting absorption principle. Letu(x,y,k) be known for all x,y∈ P ≔ {x:x3 = d}, where 0< d<h is a small fixed number (subsurface data), and allk∈ (0,k0),k0 > 0 is a small number. These data determine v(x) uniquely and an analytical procedure is given for finding v(x) given the above data. It is assumed that v(x), the inhomogeneity in the refraction coefficient (of the ocean of depth h), is an arbitrary compactly supported square integrable function
Comment on "Evolution of a Quasi-Stationary State"
Approximately forty years ago it was realized that the time development of
decaying systems might not be precisely exponential. Rolf Winter (Phys. Rev.
{\bf 123}, 1503 (1961)) analyzed the simplest nontrivial system - a particle
tunneling out of a well formed by a wall and a delta-function. He calculated
the probability current just outside the well and found irregular oscillations
on a short time scale followed by an exponential decrease followed by more
oscillations and finally by a decrease as a power of the time. We have
reanalyzed this system, concentrating on the survival probability of the
particle in the well rather than the probability current, and find a different
short time behavior.Comment: 8 pages, 6 figures, RevTex
Charged Higgs bosons in the Next-to MSSM (NMSSM)
The charged Higgs boson decays and
are studied in the framework of the next-to Minimal Supersymmetric Standard
Model (NMSSM). It is found that the decay rate for can
exceed the rates for the and channels both below and above
the top-bottom threshold. The dominance of is most readily
achieved when has a large doublet component and small mass. We also study
the production process at the LHC followed by the decay
which leads to the signature . We suggest
that is a promising discovery channel for a light charged
Higgs boson in the NMSSM with small or moderate and dominant decay
mode . This signature can also arise from
the Higgsstrahlung process followed by the decay . It is shown that there exist regions of parameter space where these
processes can have comparable cross sections and we suggest that their
respective signals can be distinguished at the LHC by using appropriate
reconstruction methods.Comment: 20 pages, 22 eps figures, more reference adde
X-ray and neutron diffraction studies of coupled structural phase transitions in DyBaCoO
A structural transition at K from the to phase
is found to coincide with an anomaly of resistivity. Another structural phase
transition doubling the lattice parameter , which has been postulated
earlier to accompany a low-temperature magnetic transition in
TbBaCoO, is observed in a single crystal DbBaCoO by
means of the X-ray and neutron diffraction. The low temperature phase does not
belong to the space group that has been chosen earlier as the highest
subgroup of the . The transition is of the first order with the
temperature hysteresis, between and K, which
probably explains anomalous magnetic properties in this temperature range.Comment: 6 pages, 4 figure
High Superconductivity, Skyrmions and the Berry Phase
It is here pointed out that the antiferromagnetic spin fluctuation may be
associated with a gauge field which gives rise to the antiferromagnetic ground
state chirality. This is associated with the chiral anomaly and Berry phase
when we consider the two dimensional spin system on the surface of a 3D sphere
with a monopole at the centre. This realizes the RVB state where spinons and
holons can be understood as chargeless spins and spinless holes attached with
magnetic flux. The attachment of the magnetic flux of the charge carrier
suggest, that this may be viewed as a skyrmion. The interaction of a massless
fermion representing a neutral spin with a gauge field along with the
interaction of a spinless hole with the gauge field enhances the
antiferromagnetic correlation along with the pseudogap at the underdoped
region. As the doping increases the antiferromagnetic long range order
disappears for the critical doping parameter . In this framework,
the superconducting pairing may be viewed as caused by skyrmion-skyrmion bound
states.Comment: 10 pages, accepted in Phys. Rev.
Large mass splittings between charged and neutral Higgs bosons in the MSSM
We show that large ( GeV) mass splittings between the charged Higgs
boson () and the neutral Higgs bosons ( and ) are possible in
the Minimal Supersymmetric Standard Model (MSSM). Such splittings occur when
the parameter is considerably larger than the common SUSY scale,
, and have significant consequences for MSSM Higgs searches at future
colliders.Comment: 11 pages, LaTex, 5 figures, version to appear in Phys. Lett.
Temporal variations in English Populations of a forest insect pest, the green spruce aphid (Elatobium abietinum), associated with the North Atlantic Oscillation and global warming
Based on an exceptionally long modern ecological dataset (41 years), it has been possible to show that warm weather in England associated with a positive North Atlantic Oscillation (NAO) index causes the spring migration of the green spruce aphid (Elatobium abietinum), a pest species of spruce trees (Picea) to start earlier, continue for longer and contain more aphids. An upward trend in the NAO index during the period 1966-2006 is associated with an increasing population size of E. abietinum. It is important to understand the mechanisms behind the population fluctuations, because this aphid causes considerable damage to Picea plantations. Present day weather associated fluctuations in forest insect pests may be useful analogues in understanding past pest outbreaks in forests
Translation, Validity, and Reliability of the Dutch Anterior Cruciate Ligament–Quality of Life Questionnaire
Background: The Anterior Cruciate Ligament–Quality of Life (ACL-QoL) questionnaire is a valid and reliable injury-specific instrument to assess the impact of an ACL rupture on the daily life of a patient. Purpose: To translate the ACL-QoL into Dutch (ACL-QoL-NL) and to study its psychometric properties in patients with an ACL rupture. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The original ACL-QoL questionnaire was translated from English to Dutch according to international guidelines. The study population consisted of 122 patients with a confirmed ACL rupture who completed the ACL-QoL-NL as well as 4 questionnaires: the International Knee Documentation Committee subjective score, Knee injury and Osteoarthritis Outcome Score, 36-item Short Form Health Survey, and Lysholm Knee Score. We determined the internal consistency, construct validity, and prevalence of floor and ceiling effects of the ACL-QoL-NL total score as well as its 5 subscales. To determine test-retest reliability, we analyzed the data of 68 patients who had a stable knee condition and who completed the ACL-QoL-NL a second time after a 2-week interval. Results: The confirmatory factor analysis showed that the original structure of the ACL-QoL-NL was confirmed, except for 4 of 31 items. Internal consistency of the total scale and all 5 subscales was good. More than 75% of the predefined hypotheses on the correlations between the ACL-QoL-NL and the 4 questionnaires were met, indicating good construct validity. No significant floor or ceiling effects were observed. Test-retest reliability was good, and no systematic bias between test and retest was found. Standard error of measurement for the total score was 4.8 points out of 100, and the smallest detectable changes at the group and individual levels were 1.6 and 13.2 points, respectively. Conclusion: The ACL-QoL-NL questionnaire was successfully translated from English to Dutch and demonstrated good internal consistency, validity, and reliability, with no presence of floor or ceiling effects
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