219 research outputs found
Real investment and risk dynamics
The spread in average returns between low and high asset growth and investment portfolios is largely accounted for by their spread in systematic risk, as measured by the Chen, Roll and Ross (1986) factors. In addition, systematic risk and volatility fall sharply during large investment periods. Consistent with the predictions of both the q-theory and real options models, the systematic risk spread and fall in risk and volatility are largest for high q rms. Moreover, investment and asset growth factors can predict economic growth. Our evidence implies that much of negative investment (asset growth)-future returns relationship can be explained by rational pricing
Multifactor Models and Their Consistency with the APT
We examine the consistency of several prominent multifactor models from the empirical asset pricing literature with the arbitrage pricing theory (APT) framework. We follow the APT-related literature and estimate the common factor structure from a rich cross-section (associated with 42 major CAPM anomalies) by employing the asymptotic principal components method. Our benchmark model contains six statistical factors and clearly dominates, in both economic and statistical terms, most of the empirical multifactor models proposed in the literature by a good margin. These results represent a critical challenge to the current workhorse models in terms of explaining large-scale equity risk premiums
Equity risk factors and the Intertemporal CAPM
We evaluate whether several equity factor models are consistent with the Merton's Intertemporal CAPM The state variables associated with (alternative) profitability factors help to forecast the equity premium in a way that is consistent with the ICAPM. Additionally, several state variables (particularly, those associated with investment factors) forecast a significant decline in stock volatility, being consistent with the corresponding factor risk prices. Moreover, there is strong evidence of predictability for future economic activity, especially from investment and profitability factors. Overall, the four-factor model o
Predicted signatures of p-wave superfluid phases and Majorana zero modes of fermionic atoms in RF absorption
We study the superfluid phases of quasi-2D atomic Fermi gases interacting via
a p-wave Feshbach resonance. We calculate the absorption spectra of these
phases under a hyperfine transition, for both non-rotating and rotating
superfluids. We show that one can identify the different phases of the p-wave
superfluid from the absorption spectrum. The absorption spectrum shows clear
signatures of the existence of Majorana zero modes at the cores of vortices of
the weakly-pairing phase
Usage Bibliometrics
Scholarly usage data provides unique opportunities to address the known
shortcomings of citation analysis. However, the collection, processing and
analysis of usage data remains an area of active research. This article
provides a review of the state-of-the-art in usage-based informetric, i.e. the
use of usage data to study the scholarly process.Comment: Publisher's PDF (by permission). Publisher web site:
books.infotoday.com/asist/arist44.shtm
Inference of Natural Selection from Interspersed Genomic Elements Based on Polymorphism and Divergence
Complete genome sequences contain valuable information about natural
selection, but extracting this information for short, widely scattered
noncoding elements remains a challenging problem. Here we introduce a new
computational method for addressing this problem called Inference of Natural
Selection from Interspersed Genomically coHerent elemenTs (INSIGHT). INSIGHT
uses a generative probabilistic model to contrast patterns of polymorphism and
divergence in the elements of interest with those in flanking neutral sites,
pooling weak information from many short elements in a manner that accounts for
variation among loci in mutation rates and genealogical backgrounds. The method
is able to disentangle the contributions of weak negative, strong negative, and
positive selection based on their distinct effects on patterns of polymorphism
and divergence. Information about divergence is obtained from multiple outgroup
genomes using a full phylogenetic model. The model is efficiently fitted to
genome-wide data by decomposing the maximum likelihood estimation procedure
into three straightforward stages. The key selection-related parameters are
estimated by expectation maximization. Using simulations, we show that INSIGHT
can accurately estimate several parameters of interest even in complex
demographic scenarios. We apply our methods to noncoding RNAs, promoter
regions, and transcription factor binding sites in the human genome, and find
clear evidence of natural selection. We also present a detailed analysis of
particular nucleotide positions within GATA2 binding sites and primary
micro-RNA transcripts.Comment: 21 page manuscript, 4 figure, 4 tables + 3 supp figures + 3 supp
tables + supp methods. V4: additional results on human noncoding RNAs
annotated by GENCODE + refinement of previous versions + additional
supplementary material included to main document. V5: some minor
modifications. V6: this is an electronic version of an article published in
Mol Biol Evol, 201
Repetition benefit in mental rotation is independent of stimulus repetition
In this study, we investigated whether there is a repetition benefit in mental rotation that is independent of stimulus repetition (i.e., due to increased efficiency in postencoding processing). Three experiments were conducted, in which different conditions of stimulus repetition (different letters on consecutive trials in Experiment 1, letters of different orientations on consecutive trials in Experiment 2, and priming of rotation direction in Experiment 3) were used, and the extent of repetition of rotation direction between two consecutive trials was manipulated. The results of all three experiments showed clear evidence of a repetition benefit without repeating the stimulus, suggesting that this effect is independent of stimulus repetition and lending support to the notion of increased efficiency in mental rotation as a result of repeated rotation direction per se
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COUPP - a search for dark matter with a continuously sensitive bubble chamber
We propose to construct and operate a 60-kg room temperature CF{sub 3}I bubble chamber as a prototype dark matter (WIMP) detector. Operating in weakly-superheated mode, the chamber will be sensitive to WIMP induced nuclear recoils above 10 keV, while rejecting background electron recoils at a level approaching 10{sup 10}. We would first commission and operate this chamber in the MINOS near detector hall with the goal to demonstrate stable operation and measure internal contamination and any other backgrounds. This chamber, or an improved version, would then be relocated to an appropriate deep underground site such as the Soudan Mine. This detector will have unique sensitivity to spin-dependent WIMP-nucleon couplings, and even in this early stage of development will attain competitive sensitivity to spin-independent couplings
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