Constitutional and Congressional Requirements Directing Public Lands Decisionmaking

15 pages. Contains references

Constitutional and Congressional Requirements Directing Public Lands Decisionmaking

15 pages. Contains references

On the nature of Bose-Einstein condensation in disordered systems

We study the perfect Bose gas in random external potentials and show that there is generalized Bose-Einstein condensation in the random eigenstates if and only if the same occurs in the one-particle kinetic-energy eigenstates, which corresponds to the generalized condensation of the free Bose gas. Moreover, we prove that the amounts of both condensate densities are equal. Our method is based on the derivation of an explicit formula for the occupation measure in the one-body kinetic-energy eigenstates which describes the repartition of particles among these non-random states. This technique can be adapted to re-examine the properties of the perfect Bose gas in the presence of weak (scaled) non-random potentials, for which we establish similar results

Relationships between task awareness, comprehension strategies, and literacy outcomes

Reading is typically guided by a task or goal (e.g., studying for a test, writing a paper). A reader’s task awareness arises from their mental representation of the task and plays an important role in guiding reading processes, ultimately influencing comprehension outcomes and task success. As such, a better understanding of how task awareness arises and how it affects comprehension is needed. The present study tested the Task Awareness Mediation Hypothesis. This hypothesis assumes that the strategies that support reading comprehension (e.g., paraphrasing, bridging, and elaborative strategies) also support a reader’s task awareness while engaged in a literacy task. Further, it assumes that the reader’s level of task awareness partially mediates the relationship between these comprehension strategies and a comprehension outcome. At two different time points in a semester, college students completed an assessment of their propensity to engage in comprehension strategies and a complex academic literacy task that provided a measure of comprehension outcomes and an assessment of task awareness. Indirect effects analyses provided evidence for the Task Awareness Mediation Hypothesis showing that the propensity to engage in paraphrasing and elaboration was positively predictive of task awareness, and that task awareness mediated the relationships between these comprehension strategies and performance on the complex academic literacy task. These results indicate that task awareness has complex relationships with comprehension strategies and performance on academic literacy tasks and warrants further consideration as a possible malleable factor to improve student success

First passage and arrival time densities for L\'evy flights and the failure of the method of images

We discuss the first passage time problem in the semi-infinite interval, for homogeneous stochastic Markov processes with L{\'e}vy stable jump length distributions $\lambda(x)\sim\ell^{\alpha}/|x|^{1+\alpha}$ ($|x|\gg\ell$), namely, L{\'e}vy flights (LFs). In particular, we demonstrate that the method of images leads to a result, which violates a theorem due to Sparre Andersen, according to which an arbitrary continuous and symmetric jump length distribution produces a first passage time density (FPTD) governed by the universal long-time decay $\sim t^{-3/2}$. Conversely, we show that for LFs the direct definition known from Gaussian processes in fact defines the probability density of first arrival, which for LFs differs from the FPTD. Our findings are corroborated by numerical results.Comment: 8 pages, 3 figures, iopart.cls style, accepted to J. Phys. A (Lett

Statistical Modeling of Transcription Factor Binding Affinities Predicts Regulatory Interactions

Recent experimental and theoretical efforts have highlighted the fact that binding of transcription factors to DNA can be more accurately described by continuous measures of their binding affinities, rather than a discrete description in terms of binding sites. While the binding affinities can be predicted from a physical model, it is often desirable to know the distribution of binding affinities for specific sequence backgrounds. In this paper, we present a statistical approach to derive the exact distribution for sequence models with fixed GC content. We demonstrate that the affinity distribution of almost all known transcription factors can be effectively parametrized by a class of generalized extreme value distributions. Moreover, this parameterization also describes the affinity distribution for sequence backgrounds with variable GC content, such as human promoter sequences. Our approach is applicable to arbitrary sequences and all transcription factors with known binding preferences that can be described in terms of a motif matrix. The statistical treatment also provides a proper framework to directly compare transcription factors with very different affinity distributions. This is illustrated by our analysis of human promoters with known binding sites, for many of which we could identify the known regulators as those with the highest affinity. The combination of physical model and statistical normalization provides a quantitative measure which ranks transcription factors for a given sequence, and which can be compared directly with large-scale binding data. Its successful application to human promoter sequences serves as an encouraging example of how the method can be applied to other sequences