273 research outputs found
Taking Behavioralism Too Seriously? The Unwarranted Pessimism of the New Behavioral Analysis of Law
Racetrack Inflation
We develop a model of eternal topological inflation using a racetrack
potential within the context of type IIB string theory with KKLT volume
stabilization. The inflaton field is the imaginary part of the K\"ahler
structure modulus, which is an axion-like field in the 4D effective field
theory. This model does not require moving branes, and in this sense it is
simpler than other models of string theory inflation. Contrary to
single-exponential models, the structure of the potential in this example
allows for the existence of saddle points between two degenerate local minima
for which the slow-roll conditions can be satisfied in a particular range of
parameter space. We conjecture that this type of inflation should be present in
more general realizations of the modular landscape. We also consider
`irrational' models having a dense set of minima, and discuss their possible
relevance for the cosmological constant problem.Comment: 23 pages 7 figures. The final version with minor modifications, to
appear in JHE
Resolved Photon Processes
We review the present level of knowledge of the hadronic structure of the
photon, as revealed in interactions involving quarks and gluons ``in" the
photon. The concept of photon structure functions is introduced in the
description of deep--inelastic scattering, and existing
parametrizations of the parton densities in the photon are reviewed. We then
turn to hard \gamp\ and \gaga\ collisions, where we treat the production of
jets, heavy quarks, hard (direct) photons, \jpsi\ mesons, and lepton pairs. We
also comment on issues that go beyond perturbation theory, including recent
attempts at a comprehensive description of both hard and soft \gamp\ and \gaga\
interactions. We conclude with a list of open problems.Comment: LaTeX with equation.sty, 85 pages, 29 figures (not included). A
complete PS file of the paper, including figures, can be obtained via
anonymous ftp from
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-898.ps.
Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs
Interspecific hybridization plays an important role in facilitating adaptive
evolutionary change. More specifically, recent studies have demonstrated that
hybridization may dramatically influence the establishment, spread, and impact
of invasive populations. In Japan, previous genetic evidence for the presence of
two non-native congeners, the European green crab Carcinus
maenas and the Mediterranean green crab C.
aestuarii, has raised questions regarding the possibility of
hybridization between these sister species. Here I present analysis based on
both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit
I (COI) gene which unambiguously argues for a hybrid origin of Japanese
Carcinus. Despite the presence of mitochondrial lineages
derived from both C. maenas and C. aestuarii,
the Japanese population is panmictic at nuclear loci and has achieved
cytonuclear equilibrium throughout the sampled range in Japan. Furthermore,
analysis of admixture at nuclear loci indicates dramatic introgression of the
C. maenas mitochondrial genome into a predominantly
C. aestuarii nuclear background. These patterns, along with
inferences drawn from the observational record, argue for a hybridization event
pre-dating the arrival of Carcinus in Japan. The clarification
of both invasion history and evolutionary history afforded by genetic analysis
provides information that may be critically important to future studies aimed at
assessing risks posed by invasive Carcinus populations to Japan
and the surrounding region
The 5-Choice Continuous Performance Test: Evidence for a Translational Test of Vigilance for Mice
Attentional dysfunction is related to functional disability in patients with neuropsychiatric disorders such as schizophrenia, bipolar disorder, and Alzheimer's disease. Indeed, sustained attention/vigilance is among the leading targets for new medications designed to improve cognition in schizophrenia. Although vigilance is assessed frequently using the continuous performance test (CPT) in humans, few tests specifically assess vigilance in rodents.We describe the 5-choice CPT (5C-CPT), an elaboration of the 5-choice serial reaction (5CSR) task that includes non-signal trials, thus mimicking task parameters of human CPTs that use signal and non-signal events to assess vigilance. The performances of C57BL/6J and DBA/2J mice were assessed in the 5C-CPT to determine whether this task could differentiate between strains. C57BL/6J mice were also trained in the 5CSR task and a simple reaction-time (RT) task involving only one choice (1CRT task). We hypothesized that: 1) C57BL/6J performance would be superior to DBA/2J mice in the 5C-CPT as measured by the sensitivity index measure from signal detection theory; 2) a vigilance decrement would be observed in both strains; and 3) RTs would increase across tasks with increased attentional load (1CRT task<5CSR task<5C-CPT).C57BL/6J mice exhibited superior SI levels compared to DBA/2J mice, but with no difference in accuracy. A vigilance decrement was observed in both strains, which was more pronounced in DBA/2J mice and unaffected by response bias. Finally, we observed increased RTs with increased attentional load, such that 1CRT task<5CSR task<5C-CPT, consistent with human performance in simple RT, choice RT, and CPT tasks. Thus we have demonstrated construct validity for the 5C-CPT as a measure of vigilance that is analogous to human CPT studies
An algorithm for chemotherapy treatment of recurrent glioma patients after temozolomide failure in the general oncology setting
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