Quantum Geometry as a Relational Construct

The problem of constructing a quantum theory of gravity is considered from a novel viewpoint. It is argued that any consistent theory of gravity should incorporate a relational character between the matter constituents of the theory. In particular, the traditional approach of quantizing a space-time metric is criticized and two possible avenues for constructing a satisfactory theory are put forward.Comment: 14 pages, revtex file. Submitted to MPL

The [OIII]++Hβ\beta Equivalent Width Distribution at z≃\simeq7: Implications for the Contribution of Galaxies to Reionization

We quantify the distribution of [OIII]+H$\beta$ line strengths at z$\simeq$7 using a sample of 20 bright (M$_{\mathrm{UV}}$ $\lesssim$ $-$21) galaxies. We select these systems over wide-area fields (2.3 deg$^2$ total) using a new colour-selection which precisely selects galaxies at z$\simeq$6.63$-$6.83, a redshift range where blue Spitzer/IRAC [3.6]$-$[4.5] colours unambiguously indicate strong [OIII]$+$H$\beta$ emission. These 20 galaxies suggest a log-normal [OIII]$+$H$\beta$ EW distribution with median EW = 759$^{+112}_{-113}$ $\mathrm{\mathring{A}}$ and standard deviation = 0.26$^{+0.06}_{-0.05}$ dex. We find no evidence for strong variation in this EW distribution with UV luminosity. The typical [OIII]+H$\beta$ EW at z$\simeq$7 implied by our sample is considerably larger than that in massive star forming galaxies at z$\simeq$2, consistent with a shift toward larger average sSFR (4.4 Gyr$^{-1}$) and lower metallicities (0.16 Z$_\odot$). We also find evidence for the emergence of a population with yet more extreme nebular emission ([OIII]+H$\beta$ EW$>$1200 $\mathrm{\mathring{A}}$) that is rarely seen at lower redshifts. These objects have extremely large sSFR ($>$30 Gyr$^{-1}$), as would be expected for systems undergoing a burst or upturn in star formation. While this may be a short-lived phase, our results suggest that 20% of the z$\simeq$7 population has such extreme nebular emission, implying that galaxies likely undergo intense star formation episodes regularly at z$>$6. We argue that this population may be among the most effective ionizing agents in the reionization era, both in terms of photon production efficiency and escape fraction. We furthermore suggest that galaxies passing through this large sSFR phase are likely to be very efficient in forming bound star clusters.Comment: 20 pages, 11 figures. Accepted in MNRAS with minor revision

Analysis of β-globin chromatin micro-environment using a novel 3C variant, 4Cv

Copyright: © 2010 Pink et al.Higher order chromatin folding is critical to a number of developmental processes, including the regulation of gene expression. Recently developed biochemical techniques such as RNA TRAP and chromosome conformation capture (3C) have provided us with the tools to probe chromosomal structures. These techniques have been applied to the β-globin locus, revealing a complex pattern of interactions with regions along the chromosome that the gene resides on. However, biochemical and microscopy data on the nature of β-globin interactions with other chromosomes is contradictory. Therefore we developed a novel 4C variant, Complete-genome 3C by vectorette amplification (4Cv), which allows an unbiased and quantitative method to examine chromosomal structure. We have used 4Cv to study the microenvironment of the β-globin locus in mice and show that a significant proportion of the interactions of β-globin are inter-chromosomal. Furthermore, our data show that in the liver, where the gene is active, β-globin is more likely to interact with other chromosomes, compared to the brain where the gene is silent and is more likely to interact with other regions along the same chromosome. Our data suggest that transcriptional activation of the β-globin locus leads to a change in nuclear position relative to the chromosome territory.Ryan Pink is supported by a grant from Action Medical Research; Daniel Caley is supported by a grant from The Dunhill Medical Trust; David Carter is supported by a grant from the British Society for Haematology

The iCanClean Algorithm: How to Remove Artifacts using Reference Noise Recordings

Data recordings are often corrupted by noise, and it can be difficult to isolate clean data of interest. For example, mobile electroencephalography is commonly corrupted by motion artifact, which limits its use in real-world settings. Here, we describe a novel noise-canceling algorithm that uses canonical correlation analysis to find and remove subspaces of corrupted data recordings that are most strongly correlated with subspaces of reference noise recordings. The algorithm, termed iCanClean, is computationally efficient, which may be useful for real-time applications, such as brain computer interfaces. In future work, we will quantify the algorithm's performance and compare it with alternative cleaning methods.Comment: 4 pages, 0 figure

Differential Effects of Buffer pH On Ca\u3csup\u3e2+\u3c/sup\u3e-Induced ROS Emission with Inhibited Mitochondrial Complexes I and III

Excessive mitochondrial reactive oxygen species (ROS) emission is a critical component in the etiology of ischemic injury. Complex I and complex III of the electron transport chain are considered the primary sources of ROS emission during cardiac ischemia and reperfusion (IR) injury. Several factors modulate ischemic ROS emission, such as an increase in extra-matrix Ca2+, a decrease in extra-matrix pH, and a change in substrate utilization. Here we examined the combined effects of these factors on ROS emission from respiratory complexes I and III under conditions of simulated IR injury. Guinea pig heart mitochondria were suspended in experimental buffer at a given pH and incubated with or without CaCl2. Mitochondria were then treated with either pyruvate, a complex I substrate, followed by rotenone, a complex I inhibitor, or succinate, a complex II substrate, followed by antimycin A, a complex III inhibitor. H2O2 release rate and matrix volume were compared with and without adding CaCl2 and at pH 7.15, 6.9, or 6.5 with pyruvate + rotenone or succinate + antimycin A to simulate conditions that may occur during in vivo cardiac IR injury. We found a large increase in H2O2 release with high [CaCl2] and pyruvate + rotenone at pH 6.9, but not at pHs 7.15 or 6.5. Large increases in H2O2 release rate also occurred at each pH with high [CaCl2] and succinate + antimycin A, with the highest levels observed at pH 7.15. The increases in H2O2 release were associated with significant mitochondrial swelling, and both H2O2 release and swelling were abolished by cyclosporine A, a desensitizer of the mitochondrial permeability transition pore (mPTP). These results indicate that ROS production by complex I and by complex III is differently affected by buffer pH and Ca2+ loading with mPTP opening. The study suggests that changes in the levels of cytosolic Ca2+ and pH during IR alter the relative amounts of ROS produced at mitochondrial respiratory complex I and complex III

Stolen Profits: Civil Shoplifting Demands and the Misuse of Neb. Rev. Stat. § 25–21,194

I. Introduction II. Background ... A. Civil Shoplifting Statutes Generally ... 1. General Authority and Amount Recoverable ... 2. Civil Demand Letters ... 3. Collection of Damages and Penalties Under Civil Shoplifting Statutes ... B. An Overview of Nebraska’s Civil Shoplifting Statute ... 1. The Origins of Nebraska’s Civil Shoplifting Statute ... 2. The Statute as Amended ... 3. Limits on Pre-Litigation Demands Under Neb. Rev. Stat. § 25–21,194 ... a. General Loss-Prevention Costs ... b. Anticipated Litigation Expenses III. Advising the Client ... A. Pay the Demand ... B. Ignore the Demand ... 1. Defending a Claim ... 2. Liability for Attorney’s Fees ... 3. Impact on Credit Rating ... C. Affirmative Legal Challenges ... 1. Federal Challenges ... a. Fair Debt Collections Practices Act … b. Racketeering Influenced and Corrupt Organization Act ... 2. Nebraska Consumer Protection Act ... a. Standing to Sue Under the NCPA ... b. Unfair or Deceptive Business Practice ... c. Trade or Commerce ... d. Affecting Public Interest ... 3. Declaratory Judgment IV. A Call to Action ... A. Legislative Repeal ... B. Legislative Amendment ... C. Education and Enforcement V. Conclusio

Stolen Profits: Civil Shoplifting Demands and the Misuse of Neb. Rev. Stat. § 25–21,194

I. Introduction II. Background ... A. Civil Shoplifting Statutes Generally ... 1. General Authority and Amount Recoverable ... 2. Civil Demand Letters ... 3. Collection of Damages and Penalties Under Civil Shoplifting Statutes ... B. An Overview of Nebraska’s Civil Shoplifting Statute ... 1. The Origins of Nebraska’s Civil Shoplifting Statute ... 2. The Statute as Amended ... 3. Limits on Pre-Litigation Demands Under Neb. Rev. Stat. § 25–21,194 ... a. General Loss-Prevention Costs ... b. Anticipated Litigation Expenses III. Advising the Client ... A. Pay the Demand ... B. Ignore the Demand ... 1. Defending a Claim ... 2. Liability for Attorney’s Fees ... 3. Impact on Credit Rating ... C. Affirmative Legal Challenges ... 1. Federal Challenges ... a. Fair Debt Collections Practices Act … b. Racketeering Influenced and Corrupt Organization Act ... 2. Nebraska Consumer Protection Act ... a. Standing to Sue Under the NCPA ... b. Unfair or Deceptive Business Practice ... c. Trade or Commerce ... d. Affecting Public Interest ... 3. Declaratory Judgment IV. A Call to Action ... A. Legislative Repeal ... B. Legislative Amendment ... C. Education and Enforcement V. Conclusio