Zone purification of potassium chloride

Procedure for removal of sodium and bromine from KCl involves zone refining in dilute halogen atmosphere. Distribution of Na and Br at concentrations of parts per million is followed by neutron-activation analyses

On Relation between Constraint Answer Set Programming and Satisfiability Modulo Theories

Constraint answer set programming is a promising research direction that integrates answer set programming with constraint processing. It is often informally related to the field of satisfiability modulo theories. Yet, the exact formal link is obscured as the terminology and concepts used in these two research areas differ. In this paper, we connect these two research areas by uncovering the precise formal relation between them. We believe that this work will booster the cross-fertilization of the theoretical foundations and the existing solving methods in both areas. As a step in this direction we provide a translation from constraint answer set programs with integer linear constraints to satisfiability modulo linear integer arithmetic that paves the way to utilizing modern satisfiability modulo theories solvers for computing answer sets of constraint answer set programs.Comment: Under consideration in Theory and Practice of Logic Programming (TPLP

Why Information Matters: A Foundation for Resilience

Embracing Change: The Critical Role of Information, a research project by the Internews' Center for Innovation & Learning, supported by the Rockefeller Foundation, combines Internews' longstanding effort to highlight the important role ofinformation with Rockefeller's groundbreaking work on resilience. The project focuses on three major aspects:- Building knowledge around the role of information in empowering communities to understand and adapt to different types of change: slow onset, long-term, and rapid onset / disruptive;- Identifying strategies and techniques for strengthening information ecosystems to support behavioral adaptation to disruptive change; and- Disseminating knowledge and principles to individuals, communities, the private sector, policymakers, and other partners so that they can incorporate healthy information ecosystems as a core element of their social resilience strategies

Contingent Fee Lobbying: Inflaming Avarice or Facilitating Constitutional Rights?

Contingent fee lobbying has long been a disfavored practice. Although some commentators argue that use of a contingent fee lobbying contract could open up federal legislative and regulatory processes to greater participation by Americans of limited means, many others, including the Supreme Court, have declared that lobbying a legislature or agency under a contingent fee contract is generally both illegal and unethical. However, the conclusion that the practice is illegal is often based on a declaration that the practice is unethical . . . without a thorough examination of the sources of law that led to the presumption of illegality in the first instance. Is it legal to lobby Congress or federal agencies on a contingent fee contract? If legal, would such a contract be ethical? These are the two core issues addressed in this article. On the way to our answers to these questions, we examine the history of lobbying and the legal treatment of lobbying. We review the early Supreme Court precedent that is often cited in support of a contingent fee lobbying ban, finding that the cases more reliably stand for a general ban on lobbying, not for a specific ban on contingent fee lobbying. We look at the evolution of lobbying – from reviled practice to respected profession – through the lenses of Senate hearings and executive branch procurement practices. We turn to the example of state law to review the competing philosophies underlying state regulation of contingent fee lobbying and to emphasize how the early Supreme Court pronouncements on lobbying may be easily employed to support either philosophy. Because the First Amendment may be implicated in any restriction on speech, we highlight how the Supreme Court’s more recent jurisprudence addressing restrictions on political speech is likely to affect any future evaluation of contingent free lobbying. Finally, regardless whether the practice of contingent fee lobbying is legal, we examine whether certain ethical boundaries should be drawn to curb any particular tendency to corruption that may result from use of a contingent fee lobbying contract. We conclude that contingent fee lobbying should not summarily be condemned or prohibited, but propose imposing a more rigorous disclosure regime specifically aimed at this type of lobbying compensation agreement

Margarete Susman : Ichform und Symbol

Die hermeneutische Grundfrage "Wer spricht?", darüber ist sich die Literaturwissenschaft heute weitgehend einig, sollte mit einer Operation beantwortet werden, welche das Subjekt einer Äußerung und das grammatikalische Subjekt der Aussage trennt. Dennoch, so behauptete jedenfalls Roland Barthes, sei die Vorstellung von Literatur noch immer "auf tyrannische Weise im Autor zentriert [...], in seiner Person, seiner Geschichte, seinem Geschmack, seinen Leidenschaften". Widerstand gegen eine solche Tyrannei formierte sich schon zu Beginn des 20. Jahrhunderts, auf dem Höhepunkt des Künstlerbiographismus. Es sei bisher übersehen worden, schrieb Margarete Susman in ihrem Buch über "Das Wesen der modernen deutschen Lyrik" (1910), daß das "lyrische Ich [...] kein Ich im real empirischen Sinne, sondern daß es "Ausdruck", daß es "Form" eines Ich" sei. Dieser Satz, der die Selbständigkeit des Textes gegenüber dem Autor behauptet, war in der ästhetischen Theorie nirgends vorher mit dieser Entschiedenheit ausgesprochen worden. Mit dem von Susman kreierten Begriff des "lyrischen Ich" operierte fortan die Zunft. Was ihn provoziert hat, ist eine historische Frage, die allerdings ihrerseits nicht ohne Lebensgeschichte auskommt

Single-cell protein dynamics reproduce universal fluctuations in cell populations

Protein variability in single cells has been studied extensively in populations, but little is known about temporal protein fluctuations in a single cell over extended times. We present here traces of protein copy number measured in individual bacteria over multiple generations and investigate their statistical properties, comparing them to previously measured population snapshots. We find that temporal fluctuations in individual traces exhibit the same universal features as those previously observed in populations. Scaled fluctuations around the mean of each trace exhibit the same universal distribution shape as found in populations measured under a wide range of conditions and in two distinct microorganisms. Additionally, the mean and variance of the traces over time obey the same quadratic relation. Analyzing the temporal features of the protein traces in individual cells, reveals that within a cell cycle protein content increases as an exponential function with a rate that varies from cycle to cycle. This leads to a compact description of the protein trace as a 3-variable stochastic process - the exponential rate, the cell-cycle duration and the value at the cycle start - sampled once each cell cycle. This compact description is sufficient to preserve the universal statistical properties of the protein fluctuations, namely, the protein distribution shape and the quadratic relationship between variance and mean. Our results show that the protein distribution shape is insensitive to sub-cycle intracellular microscopic details and reflects global cellular properties that fluctuate between generations

Domestic UK retrofit challenge: Barriers, incentives and current performance leading into the green deal

Copyright @ 2012 Elsevier - The official published version can be accessed from the link below.This paper reviews the thermal performance of the existing UK housing stock, the main fabric efficiency incentive schemes and the barriers to obtaining deep energy and CO2 savings throughout the stock. The UK faces a major challenge to improve the thermal performance of its existing housing stock. Millions of dwellings possess ‘hard-to-treat’ solid walls and have glazing which is not cost effective to improve. A range of fabric efficiency incentive schemes exist, but many do not target the full range of private and social housing. From now on, the Green Deal will be the UK's key energy efficiency policy. However, the scheme is forecasted to have low consumer appeal and low incentives for investors. Moreover, calculated Green Deal loan repayments will be reliant upon estimated energy savings, yet it is claimed that retrofit measures may only be half as effective as anticipated due to a lack of monitoring, poor quality installation and the increased use of heating following refurbishment. Looking to Germany, there has been success through the Passivhaus standard, but the UK currently lacks appropriate skills and cost effective components to replicate this approach. In addition, the embodied energy in retrofit products and materials threatens to counter operational savings.This study is funded by the EPSRC, Brunel University and Buro Happold Ltd

Lean Aircraft Initiative Product Development Team Effectiveness

The current study explores the relative influence of function managers and team leaders in managing integrated product development teams (IPTs). This study was prompted by the results of an earlier study, completed in Spring 1995, which suggested that the most successful high risk projects had a 50/50 balance of influence in decision-malting between function managers and team leaders. This study also suggested that in the most successful low risk projects, the balance of influence shifted heavily toward team leaders

Individuality and slow dynamics in bacterial growth homeostasis

Microbial growth and division are fundamental processes relevant to many areas of life science. Of particular interest are homeostasis mechanisms, which buffer growth and division from accumulating fluctuations over multiple cycles. These mechanisms operate within single cells, possibly extending over several division cycles. However, all experimental studies to date have relied on measurements pooled from many distinct cells. Here, we disentangle long-term measured traces of individual cells from one another, revealing subtle differences between temporal and pooled statistics. By analyzing correlations along up to hundreds of generations, we find that the parameter describing effective cell-size homeostasis strength varies significantly among cells. At the same time, we find an invariant cell size which acts as an attractor to all individual traces, albeit with different effective attractive forces. Despite the common attractor, each cell maintains a distinct average size over its finite lifetime with suppressed temporal fluctuations around it, and equilibration to the global average size is surprisingly slow (> 150 cell cycles). To demonstrate a possible source of variable homeostasis strength, we construct a mathematical model relying on intracellular interactions, which integrates measured properties of cell size with those of highly expressed proteins. Effective homeostasis strength is then influenced by interactions and by noise levels, and generally varies among cells. A predictable and measurable consequence of variable homeostasis strength appears as distinct oscillatory patterns in cell size and protein content over many generations. We discuss the implications of our results to understanding mechanisms controlling division in single cells and their characteristic timescalesComment: In press with PNAS. 50 pages, including supplementary informatio