15,115 research outputs found
Multiracial Malaise: Multiracial as a \u3cem\u3eLegal\u3c/em\u3e Racial Category
One byproduct of increased interracial marriages post Loving is a growing number of multiracial children. This cohort of multiracials tends to overshadow older and larger generations of multiracial people whose genealogical mixture is more distant. Some interracial couples, their multiracial children and others support a multiracial category on the U.S. Census. Proponents argued that multiracial individuals experience a unique type of discrimination that warrants treating them as a separate racial category. This article concedes that multiracial individuals should enjoy the freedom to self-identify as they wish, and like others, be protected by anti-discrimination law. It concludes, however, that current arguments for a multiracial legal category are unpersuasive
Regulating Eternal Inflation II: The Great Divide
In a previous paper, two of the authors presented a "regulated" picture of
eternal inflation. This picture both suggested and drew support from a
conjectured discontinuity in the amplitude for tunneling from positive to
negative vacuum energy, as the positive vacuum energy was sent to zero;
analytic and numerical arguments supporting this conjecture were given. Here we
show that this conjecture is false, but in an interesting way. There are no
cases where tunneling amplitudes are discontinuous at vanishing cosmological
constant; rather, the space of potentials separates into two regions. In one
region decay is strongly suppressed, and the proposed picture of eternal
inflation remains viable; sending the (false) vacuum energy to zero in this
region results in an absolutely stable asymptotically flat space. In the other
region, we argue that the space-time at vanishing cosmological constant is
unstable, but not asymptotically Minkowski. The consequences of our results for
theories of supersymmetry breaking are unchanged.Comment: JHEP3, 19 Pages, 7 Figure
Embedding the Pentagon
The Pentagon Model is an explicit supersymmetric extension of the Standard
Model, which involves a new strongly-interacting SU(5) gauge theory at
TeV-scale energies. We show that the Pentagon can be embedded into an SU(5) x
SU(5) x SU(5) gauge group at the GUT scale. The doublet-triplet splitting
problem, and proton decay compatible with experimental bounds, can be
successfully addressed in this context. The simplest approach fails to provide
masses for the lighter two generations of quarks and leptons; however, this
problem can be solved by the addition of a pair of antisymmetric tensor fields
and an axion.Comment: 39 page
Effects of 7-day repeated treatment with the 5-HT2A inverse agonist/antagonist pimavanserin on methamphetamine vs. food choice in male rhesus monkeys
Background Preclinical drug vs. food choice is an emerging group of drug self-administration procedures that have shown predictive validity to clinical drug addiction. Emerging data suggest that serotonin (5-HT)2A receptors modulate mesolimbic dopamine function, such that 5-HT2A antagonists blunt the abuse-related neurochemical effects of monoamine transporter substrates, such as amphetamine or methamphetamine. Whether subchronic 5-HT2A antagonist treatment attenuates methamphetamine reinforcement in any preclinical drug self-administration procedure is unknown. The study aim was therefore to determine 7-day treatment effects with the 5-HT2A inverse agonist/antagonist pimavanserin on methamphetamine vs. food choice in monkeys. Methods Behavior was maintained under a concurrent schedule of food delivery (1 g pellets, fixed-ratio 100 schedule) and intravenous methamphetamine injections (0–0.32 mg/kg/injection, fixed-ratio 10 schedule) in male rhesus monkeys (n = 3). Methamphetamine choice dose-effect functions were determined daily before and during 7-day repeated pimavanserin (1.0–10 mg/kg/day, intramuscular) treatment periods. Results Under control conditions, increasing methamphetamine doses resulted in a corresponding increase in methamphetamine vs. food choice. Repeated pimavanserin administration failed to attenuate methamphetamine choice and produce a reciprocal increase in food choice in any monkey up to doses (3.2–10 mg/kg) that suppressed rates of operant responding primarily during components where behavior was maintained by food pellets. Conclusions Repeated 5-HT2A receptor inverse agonist/antagonist treatment did not attenuate methamphetamine reinforcement under a concurrent schedule of intravenous methamphetamine and food presentation in nonhuman primates. Overall, these results do not support the therapeutic potential of 5-HT2A inverse agonists/antagonists as candidate medications for methamphetamine addiction
Data Mining in Electronic Commerce
Modern business is rushing toward e-commerce. If the transition is done
properly, it enables better management, new services, lower transaction costs
and better customer relations. Success depends on skilled information
technologists, among whom are statisticians. This paper focuses on some of the
contributions that statisticians are making to help change the business world,
especially through the development and application of data mining methods. This
is a very large area, and the topics we cover are chosen to avoid overlap with
other papers in this special issue, as well as to respect the limitations of
our expertise. Inevitably, electronic commerce has raised and is raising fresh
research problems in a very wide range of statistical areas, and we try to
emphasize those challenges.Comment: Published at http://dx.doi.org/10.1214/088342306000000204 in the
Statistical Science (http://www.imstat.org/sts/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Baryogenesis, Dark Matter and the Pentagon
We present a new mechanism for baryogenesis, which links the baryon asymmetry
of the universe to the dark matter density. The mechanism arises naturally in
the Pentagon model of TeV scale physics. In that context, it forces a
re-evaluation of some of the assumptions of the model, and we detail the
changes that are required in order to fit observations.Comment: JHEP3 LaTeX, 15 pages. New version corrects errors in the electroweak
baryon violating and matter radiation temperatures, which were pointed out by
the referee. Substantial quantitative but no qualitative change to our
conclusion
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