5,106 research outputs found
Alien Registration- Cox, Robert H. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/24088/thumbnail.jp
Regulatory activity revealed by dynamic correlations in gene expression noise
Gene regulatory interactions are context dependent, active in some cellular states but not in others. Stochastic fluctuations, or 'noise', in gene expression propagate through active, but not inactive, regulatory links^(1,2). Thus, correlations in gene expression noise could provide a noninvasive means to probe the activity states of regulatory links. However, global, 'extrinsic', noise sources generate correlations even without direct regulatory links. Here we show that single-cell time-lapse microscopy, by revealing time lags due to regulation, can discriminate between active regulatory connections and extrinsic noise. We demonstrate this principle mathematically, using stochastic modeling, and experimentally, using simple synthetic gene circuits. We then use this approach to analyze dynamic noise correlations in the galactose metabolism genes of Escherichia coli. We find that the CRP-GalS-GalE feed-forward loop is inactive in standard conditions but can become active in a GalR mutant. These results show how noise can help analyze the context dependence of regulatory interactions in endogenous gene circuits
Second-Hand Stress: Neurobiological Evidence for a Human Alarm Pheromone
Alarm pheromones are airborne chemical signals, released by an individual into the environment, which transmit warning of danger to conspecifics via olfaction. Using fMRI, we provide the first neurobiological evidence for a human alarm pheromone. Individuals showed activation of the amygdala in response to sweat produced by others during emotional stress, with exercise sweat as a control; behavioral data suggest facilitated evaluation of ambiguous threat
Cognitive Information Processing
Contains reports on three research projects.Joint Services Electronics Program (Contract DAAB07-74-C-0630)National Science Foundation (Grant GK-33736X2
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How to connect time-lapse recorded trajectories of motile microorganisms with dynamical models in continuous time
Representations of integers by certain positive definite binary quadratic forms
We prove part of a conjecture of Borwein and Choi concerning an estimate on
the square of the number of solutions to n=x^2+Ny^2 for a squarefree integer N.Comment: 8 pages, submitte
Make Research Data Public? -- Not Always so Simple: A Dialogue for Statisticians and Science Editors
Putting data into the public domain is not the same thing as making those
data accessible for intelligent analysis. A distinguished group of editors and
experts who were already engaged in one way or another with the issues inherent
in making research data public came together with statisticians to initiate a
dialogue about policies and practicalities of requiring published research to
be accompanied by publication of the research data. This dialogue carried
beyond the broad issues of the advisability, the intellectual integrity, the
scientific exigencies to the relevance of these issues to statistics as a
discipline and the relevance of statistics, from inference to modeling to data
exploration, to science and social science policies on these issues.Comment: Published in at http://dx.doi.org/10.1214/10-STS320 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Mallard Duckling Growth and Survival in Relation to Aquatic Invertebrates
Identification and assessment of the relative importance of factors affecting duckling growth and survival are essential for effective management of mallards on breeding areas. For each of 3 years (1993-95), we placed Fl-generation wild mallard (Anas platyrhynchos) females on experimental wetlands and allowed them to mate, nest, and rear broods for 17 days. We manipulated invertebrate densities by introducing fathead minnows (Pimephales promelas) at high densities in half of the wetlands on which broods were confined. Day- 17 body mass of surviving ducklings (n = 183) was greater for ducklings that were heavier at hatch; the difference averaged 1.7 g at day 17 for each 1.0 g at hatch (P = 0.047). Growth ratio (the proportion of body mass attained by ducklings when they were last measured relative to that predicted for wild female mallard ducklings) also was positively related to body mass at hatch (P = 0.004). Mean day-17 body mass and mean growth ratio of ducklings per brood (each adjusted for body mass at hatch) were positively related to numbers of aquatic invertebrates (Ps \u3c 0.001) and negatively related to variance in the daily minimum air temperature during the exposure period (Ps \u3c 0.020). Early growth of mallards was more sensitive to variation in numbers of invertebrates than to air temperature or biomass of invertebrates. Duckling survival was positively related to growth ratio (P \u3c 0.001). Our study provides parameter estimates that are essential for modeling growth and survival of mallard ducklings. We emphasize the need for conserving brood-rearing wetlands in the Prairie Pothole Region that are capable of supporting high densities of aquatic invertebrates
On Charge-3 Cyclic Monopoles
We determine the spectral curve of charge 3 BPS su(2) monopoles with C_3
cyclic symmetry. The symmetry means that the genus 4 spectral curve covers a
(Toda) spectral curve of genus 2. A well adapted homology basis is presented
enabling the theta functions and monopole data of the genus 4 curve to be given
in terms of genus 2 data. The Richelot correspondence, a generalization of the
arithmetic mean, is used to solve for this genus 2 curve. Results of other
approaches are compared.Comment: 34 pages, 16 figures. Revision: Abstract added and a few small
change
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