590 research outputs found
The Recent Respectability of Summary Judgments and Directed Verdicts in Intentional Age Discrimination Cases: ADEA Case Analysis through the Supreme Court\u27s Summary Judgment Prism
The purpose of this Article is to review recent Supreme Court guidance on standards for summary judgment and directed verdict and the effect these decisions are having upon ADEA cases
Four Imperatives Driving Business Schools to Adopt Mobile Content Delivery
Look around at people on any sidewalk, school hallway, classroom, and, most disturbingly, any car around yours on the road. You know that you are likely to see a staggering percentage of those people staring into the screen of a “smart” phone. Millennials and post-millennials are constantly “connected.” The Millennials even connect during class; at best to fact-check their teachers, at worst, to check the latest updates on Facebook. It will only get worse with the soon to arrive Post-Millennials who have been termed “millennials on steroids” by Lucie Green, the worldwide director of the Innovation Group at J. Walter Thompson. Post-millennials who account for a quarter of the U.S. population have not had to adapt to these devices. They were born into them and will expect nothing less than having them as a fixture in their learning experience. Significantly, the parents of post-millennials concur with their Generation Z offspring and believe that education technology has a positive influence on their children’s learning. Universities are struggling to catch up to this trend, with mixed results. Since teaching about the importance of detecting and acting proactively on macroenvironmental changes is part of its curriculum, it is particularly incumbent upon the AACSB-accredited business schools to lead the way for the rest of academe. This paper will report on the four main imperatives driving universities, and business schools in particular, to adopt mobile content delivery. Specifically, those imperatives are demographics, finances, ubiquitous technology, and concerns over accreditation. The current AACSB accreditation standards are built around three themes: innovation, impact, and engagement. Adopting mobile content delivery would seem to fit ideally within this new framework. This paper will discuss some innovative methods currently being employed by schools of business to utilize mobile delivery of teaching content. Finally, it will point out the advantages and the disadvantages associated with departing from the traditional classroom content delivery model
Structural Properties of Central Galaxies in Groups and Clusters
Using a representative sample of 911 central galaxies (CENs) from the SDSS
DR4 group catalogue, we study how the structure of the most massive members in
groups and clusters depend on (1) galaxy stellar mass (Mstar), (2) dark matter
halo mass of the host group (Mhalo), and (3) their halo-centric position. We
establish and thoroughly test a GALFIT-based pipeline to fit 2D Sersic models
to SDSS data. We find that the fitting results are most sensitive to the
background sky level determination and strongly recommend using the SDSS global
value. We find that uncertainties in the background translate into a strong
covariance between the total magnitude, half-light size (r50), and Sersic index
(n), especially for bright/massive galaxies. We find that n depends strongly on
Mstar for CENs, but only weakly or not at all on Mhalo. Less (more) massive
CENs tend to be disk (spheroid)-like over the full Mhalo range. Likewise, there
is a clear r50-Mstar relation for CENs, with separate slopes for disks and
spheroids. When comparing CENs with satellite galaxies (SATs), we find that low
mass (<10e10.75 Msun/h^2) SATs have larger median n than CENs of similar Mstar.
Low mass, late-type SATs have moderately smaller r50 than late-type CENs of the
same Mstar. However, we find no size differences between spheroid-like CENs and
SATs, and no structural differences between CENs and SATs matched in both mass
and colour. The similarity of massive SATs and CENs shows that this distinction
has no significant impact on the structure of spheroids. We conclude that Mstar
is the most fundamental property determining the basic structure of a galaxy.
The lack of a clear n-Mhalo relation rules out a distinct group mass for
producing spheroids, and the responsible morphological transformation processes
must occur at the centres of groups spanning a wide range of masses. (abridged)Comment: 22 pages, 14 figures, submitted to MNRA
Ongoing Assembly of Massive Galaxies by Major Merging in Large Groups and Clusters from the SDSS
We investigate the incidence of major mergers creating >10e11 Msun galaxies
in present-day groups and clusters more massive than 2.5e13 Msun. We identify
38 pairs of massive galaxies with mutual tidal interaction signatures selected
from >5000 galaxies with >5e10 Msun that reside in 845 such groups. We fit the
images of each galaxy pair as the line-of-sight projection of symmetric models
and identify mergers by the presence of residual asymmetries around each
progenitor, such as off-center isophotes, broad tidal tails, and dynamical
friction wakes. At the resolution and sensitivity of the SDSS, such mergers are
found in 16% of high-mass, galaxy-galaxy pairs with magnitude differences of
<1.5 and <30 kpc projected separations. We find that 90% of these mergers have
nearly equal-mass progenitors with red-sequence colors and
centrally-concentrated morphologies, the hallmarks of dissipationless merger
simulations. Mergers at group centers are more common than between 2
satellites, but both are morphologically indistinguishable and we tentatively
conclude that the latter are likely located at the dynamical centers of
recently accreted subhalos. The frequency of central and satellite merging
diminishes with group mass consistent with dynamical friction expectations.
Based on reasonable assumptions, the centers of these massive halos are growing
in stellar mass by 1-9% per Gyr, on average. Compared to all LRG-LRG mergers,
we find a 2-9 times higher rate for their merging when restricted to these
dense environments. Our results imply that the massive end of the galaxy
population continues to evolve hierarchically at a measurable level, and that
the centers of massive groups are the preferred environment for merger-driven
galaxy assembly. (abridged)Comment: 48 pages, 21 figures. Submitted for publication in MNRAS. Version
with full resolution figures at
http://www.astro.umass.edu/~dmac/Preprints/mergers.hires.pd
Precision Top-Quark Mass Measurements at CDF
We present a precision measurement of the top-quark mass using the full
sample of Tevatron TeV proton-antiproton collisions collected
by the CDF II detector, corresponding to an integrated luminosity of 8.7
. Using a sample of candidate events decaying into the
lepton+jets channel, we obtain distributions of the top-quark masses and the
invariant mass of two jets from the boson decays from data. We then compare
these distributions to templates derived from signal and background samples to
extract the top-quark mass and the energy scale of the calorimeter jets with
{\it in situ} calibration. The likelihood fit of the templates from signal and
background events to the data yields the single most-precise measurement of the
top-quark mass, \mtop = 172.85 \pm\pmComment: submitted to Phys. Rev. Let
A search for resonant production of pairs in $4.8\ \rm{fb}^{-1}p\bar{p}\sqrt{s}=1.96\ \rm{TeV}$
We search for resonant production of tt pairs in 4.8 fb^{-1} integrated
luminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay
channel, where one top quark decays leptonically and the other hadronically. A
matrix element reconstruction technique is used; for each event a probability
density function (pdf) of the ttbar candidate invariant mass is sampled. These
pdfs are used to construct a likelihood function, whereby the cross section for
resonant ttbar production is estimated, given a hypothetical resonance mass and
width. The data indicate no evidence of resonant production of ttbar pairs. A
benchmark model of leptophobic Z \rightarrow ttbar is excluded with m_{Z'} <
900 GeV at 95% confidence level.Comment: accepted for publication in Physical Review D Sep 21, 201
Evidence for t\bar{t}\gamma Production and Measurement of \sigma_t\bar{t}\gamma / \sigma_t\bar{t}
Using data corresponding to 6.0/fb of ppbar collisions at sqrt(s) = 1.96 TeV
collected by the CDF II detector, we present a cross section measurement of
top-quark pair production with an additional radiated photon. The events are
selected by looking for a lepton, a photon, significant transverse momentum
imbalance, large total transverse energy, and three or more jets, with at least
one identified as containing a b quark. The ttbar+photon sample requires the
photon to have 10 GeV or more of transverse energy, and to be in the central
region. Using an event selection optimized for the ttbar+photon candidate
sample we measure the production cross section of, and the ratio of cross
sections of the two samples. Control samples in the dilepton+photon and
lepton+photon+\met, channels are constructed to aid in decay product
identification and background measurements. We observe 30 ttbar+photon
candidate events compared to the standard model expectation of 26.9 +/- 3.4
events. We measure the ttbar+photon cross section to be 0.18+0.08 pb, and the
ratio of the cross section of ttbar+photon to ttbar to be 0.024 +/- 0.009.
Assuming no ttbar+photon production, we observe a probability of 0.0015 of the
background events alone producing 30 events or more, corresponding to 3.0
standard deviations.Comment: 9 pages, 3 figure
Combined search for the standard model Higgs boson decaying to a bb pair using the full CDF data set
We combine the results of searches for the standard model Higgs boson based
on the full CDF Run II data set obtained from sqrt(s) = 1.96 TeV p-pbar
collisions at the Fermilab Tevatron corresponding to an integrated luminosity
of 9.45/fb. The searches are conducted for Higgs bosons that are produced in
association with a W or Z boson, have masses in the range 90-150 GeV/c^2, and
decay into bb pairs. An excess of data is present that is inconsistent with the
background prediction at the level of 2.5 standard deviations (the most
significant local excess is 2.7 standard deviations).Comment: To be published in Phys. Rev. Lett (v2 contains minor updates based
on comments from PRL
Measurement of the Cross Section and Triple Gauge Couplings in Collisions at TeV
This Letter describes the current most precise measurement of the
production cross section as well as limits on anomalous couplings at a
center-of-mass energy of 1.96 TeV in proton-antiproton collisions for the
Collider Detector at Fermilab (CDF). candidates are reconstructed from
decays containing three charged leptons and missing energy from a neutrino,
where the charged leptons are either electrons or muons. Using data collected
by the CDF II detector (7.1 fb of integrated luminosity), 63 candidate
events are observed with the expected background contributing events.
The measured total cross section pb is in good
agreement with the standard model prediction of . The same sample
is used to set limits on anomalous couplings.Comment: Resubmission to PRD-RC after acceptance (27 July 2012
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