928 research outputs found
Defending Daubert: It\u27s Time to Amend Federal Rule of Evidence 702
The 2000 amendments to Rule 702 sought to resolve the debate that had emerged in the courts in the 1990s over the proper meaning of Daubert by codifying the rigorous and structured approach to expert admissibility announced in the Daubert trilogy. Fifteen years later, however, the amendments have only partially accomplished this objective. Many courts continue to resist the judiciaryās proper gatekeeping role, either by ignoring Rule 702ās mandate altogether or by aggressively reinterpreting the Ruleās provisions.
Informed by this additional history of recalcitrance, the time has come for the Judicial Conference to return to the drafting table and finish the job it began in 2000. Rule 702 should be amended to secure the promise of Daubert and effectively protect future litigants and juries from the powerful and quite misleading impact of unreliable expert testimony
Forecasting Volatility of Dhaka Stock Exchange: Linear Vs Non-linear Models
Prior information about a financial market is very essential for investor to invest money on parches share from the stock market which can strengthen the economy. The study examines the relative ability of various models to forecast daily stock indexes future volatility. The forecasting models that employed from simple to relatively complex ARCH-class models. It is found that among linear models of stock indexes volatility, the moving average model ranks first using root mean square error, mean absolute percent error, Theil-U and Linex loss function criteria. We also examine five nonlinear models. These models are ARCH, GARCH, EGARCH, TGARCH and restricted GARCH models. We find that nonlinear models failed to dominate linear models utilizing different error measurement criteria and moving average model appears to be the best. Then we forecast the next two months future stock index price volatility by the best (moving average) model
MultiFit: a web server for fitting multiple protein structures into their electron microscopy density map
Advances in electron microscopy (EM) allow for structure determination of large biological assemblies at increasingly higher resolutions. A key step in this process is fitting multiple component structures into an EM-derived density map of their assembly. Here, we describe a web server for this task. The server takes as input a set of protein structures in the PDB format and an EM density map in the MRC format. The output is an ensemble of models ranked by their quality of fit to the density map. The models can be viewed online or downloaded from the website. The service is available at; http://salilab.org/multifit/ and http://bioinfo3d.cs.tau.ac.il/
The identification of the optical companion to the binary millisecond pulsar J0610-2100 in the Galactic field
We have used deep V and R images acquired at the ESO Very Large Telescope to
identify the optical companion to the binary pulsar PSR J0610-2100, one of the
black-widow millisecond pulsars recently detected by the Fermi Gamma-ray
Telescope in the Galactic plane. We found a faint star (V~26.7) nearly
coincident (\delta r ~0".28) with the pulsar nominal position. This star is
visible only in half of the available images, while it disappears in the
deepest ones (those acquired under the best seeing conditions), thus indicating
that it is variable. Although our observations do not sample the entire orbital
period (P=0.28 d) of the pulsar, we found that the optical modulation of the
variable star nicely correlates with the pulsar orbital period and describes a
well defined peak (R~25.6) at \Phi=0.75, suggesting a modulation due to the
pulsar heating. We tentatively conclude that the companion to PSR J0610-2100 is
a heavily ablated very low mass star (~ 0.02Msun) that completely filled its
Roche Lobe.Comment: 17 pages, 5 figures - Accepted for pubblication in Ap
New X-ray observations of the Geminga pulsar wind nebula
Previous observations of the middle-aged pulsar Geminga with XMM-Newton and
Chandra have shown an unusual pulsar wind nebula (PWN), with a 20" long central
(axial) tail directed opposite to the pulsar's proper motion and two 2' long,
bent lateral (outer) tails. Here we report on a deeper (78 ks) Chandra
observation and a few additional XMM-Newton observations of the Geminga PWN.
The new Chandra observation has shown that the axial tail, which includes up to
three brighter blobs, extends at least 50" (i.e., 0.06 d_{250} pc) from the
pulsar. It also allowed us to image the patchy outer tails and the emission in
the immediate vicinity of the pulsar with high resolution. The PWN luminosity,
L_{0.3-8 keV} ~ 3\times 10^{29} d_{250}^2 erg/s, is lower than the pulsar's
magnetospheric luminosity by a factor of 10. The spectra of the PWN elements
are rather hard (photon index ~ 1). Comparing the two Chandra images, we found
evidence of PWN variability, including possible motion of the blobs along the
axial tail. The X-ray PWN is the synchrotron radiation from relativistic
particles of the pulsar wind; its morphology is connected with the supersonic
motion of Geminga. We speculate that the outer tails are either (1) a sky
projection of the limb-brightened boundary of a shell formed in the region of
contact discontinuity, where the wind bulk flow is decelerated by shear
instability, or (2) polar outflows from the pulsar bent by the ram pressure
from the ISM. In the former case, the axial tail may be a jet emanating along
the pulsar's spin axis, perhaps aligned with the direction of motion. In the
latter case, the axial tail may be the shocked pulsar wind collimated by the
ram pressure.Comment: 16 pages, including 6 figures; minor changes in the text; typos
corrected; published in Ap
The Orbital Period and Negative Superhumps of the Nova-Like Cataclysmic Variable V378 Pegasi
A radial velocity study is presented of the cataclysmic variable V378 Pegasi
(PG 2337+300). It is found to have an orbital period of 0.13858 +/- 0.00004 d
(3.32592 +/- 0.00096 hours). Its spectrum and long-term light curve suggest
that V378 Peg is a nova-like variable, with no outbursts. We use the
approximate distance and position in the Galaxy of V378 Peg to estimate E(B-V)
= 0.095, and use near-infrared magnitudes to calculate a distance of 680 +/- 90
pc and M_V = 4.68 +/- 0.70, consistent with V378 Peg being a nova-like.
Time-resolved photometry taken between 2001 and 2009 reveals a period of 0.1346
+/- 0.0004 d (3.23 +/- 0.01 hours). We identify this photometric variability to
be negative superhumps, from a precessing, tilted accretion disk. Our repeated
measurements of the photometric period of V378 Peg are consistent with this
period having been stable between 2001 and 2009, with its negative superhumps
showing coherence over as many as hundreds or even thousands of cycles.Comment: 24 pages, 19 figures, accepted for publication in New Astronom
The turbulent destruction of clouds - III. Three-dimensional adiabatic shock-cloud simulations
We present 3D hydrodynamic simulations of the adiabatic interaction of a shock with a dense, spherical cloud. We compare how the nature of the interaction changes with the Mach number of the shock, M, and the density contrast of the cloud, Ļ. We examine the differences with 2D axisymmetric calculations, perform detailed resolution tests, and compare āinviscidā results to those obtained with the inclusion of a k-Ļµ subgrid turbulence model. Resolutions of 32ā64 cells per cloud radius are the minimum necessary to capture the dominant dynamical processes in 3D simulations, while the 3D inviscid and k-Ļµ simulations typically show very good agreement. Clouds accelerate and mix up to five times faster when they are poorly resolved. The interaction proceeds very similarly in 2D and 3D ā although non-azimuthal modes lead to different behaviour, there is very little effect on key global quantities such as the lifetime of the cloud and its acceleration. In particular, we do not find significant differences in the hollowing or āvoidingā of the cloud between 2D and 3D simulations with M = 10 and Ļ = 10, which contradicts previous work in the literature
Alumnae Association Bulletin of the School of Nursing, 1973
Alumnae Calendar
The President\u27s Message
Officers and Chairmen of Committees
Financial Report
Annual Reports
Named to Academy of Nursing
Alumnae Association Relief Fund Benefits
Sesquicentennial - A Celebration and a Challenge
Progress of the Thomas Jefferson University Hospital 1972-1973
Report of the Patient Services Department
Changes in the Department of Radiation Therapy
Annual Luncheon
Committee Reports
Administration
Missing Alumnae Members
Salute to Life Members
The Class of 1973
Ways and Means Committee Report
Resume of Minutes of Alumnae Association Meetings
Class Notes
Marriages
Births
In Memoriam
Notice
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