The in-situ cometary particulate size distribution measured for one comet: P/Halley

The close approach of Giotto to comet Halley during its 1986 apparition offered an opportunity to study the particulate mass distribution to masses of up to one gram. Data acquired by the front end channels of the highly sensitive mass spectrometer PIA and the dust shield detector system, DIDSY, provide definition to the detected distribution as close as 1000 km to the nucleus. Dynamic motion of the particulates after emission leads to a spatial differentiation affecting the size distribution in several forms: (1) ejecta velocity dispersion; (2) radiation pressure; (3) varying heliocentric distance; and (4) anisotropic nucleus emission. Transformation of the in-situ distribution from PIA and DIDSY weighted heavily by the near-nucleus fluxes leads to a presumed nucleus distribution. The data lead to a puzzling distribution at large masses, not readily explained in an otherwise monotonous power law distribution. Although temporal changes in nucleus activity could and do modify the in-situ size distribution, such an explanation is not wholly possible, because the same form is observed at differing locations in the coma where the time of flight from the nucleus greatly varies. Thus neither a general change in comet activity nor spatial variations lead to a satisfactory explanation

Point singularities and suprathreshold stochastic resonance in optimal coding

Motivated by recent studies of population coding in theoretical neuroscience, we examine the optimality of a recently described form of stochastic resonance known as suprathreshold stochastic resonance, which occurs in populations of noisy threshold devices such as models of sensory neurons. Using the mutual information measure, it is shown numerically that for a random input signal, the optimal threshold distribution contains singularities. For large enough noise, this distribution consists of a single point and hence the optimal encoding is realized by the suprathreshold stochastic resonance effect. Furthermore, it is shown that a bifurcational pattern appears in the optimal threshold settings as the noise intensity increases. Fisher information is used to examine the behavior of the optimal threshold distribution as the population size approaches infinity.Comment: 11 pages, 3 figures, RevTe

Management Research on Multinational Corporations: A Methodological Critique

In the context of burgeoning research on multinational corporations (MNCs), this paper addresses the issue of the representativeness of databases of MNCs in Ireland. It identifies some important deficiencies in existing databases much used by scholars in the field. Drawing on the international literature, it finds that this problem also characterises research on MNCs in many other countries. In the Irish context, we find that the extant empirical research has generally excluded two key categories of MNCs, namely, (a) foreign MNCs which are not grant-aided by the main industrial promotions agencies and (b) Irish-owned MNCs. The paper outlines our experience in identifying and addressing these deficiencies and describes the methods that might be employed in more precisely defining the MNC population in Ireland. More generally the paper reviews some of the issues and obstacles confronting scholars investigating the MNC sector in Ireland and abroad.

Aerothermal modeling program, phase 2. Element C: Fuel injector-air swirl characterization

The main objectives of the NASA-sponsored Aerothermal Modeling Program, Phase 2--Element C, are experimental evaluation of the air swirler interaction with a fuel injector in a simulated combustor chamber, assessment of the current two-phase models, and verification of the improved spray evaporation/dispersion models. This experimental and numerical program consists of five major tasks. Brief descriptions of the five tasks are given

Exploring the relationship between Shame Memories, Self-Concept and Wellbeing

Background: High levels of shame are considered a transdiagnostic experience, and have been associated with early shame memories that contain traumatic features and become central to one’s self-concept. Compassion Focused Therapy aims to reduce shame via compassionate exercises. Difficulties, however, can be experienced when these are attempted, and identifying fears around developing compassion might not be helpful for all individuals. Consequently, there is a clinical need to consider alternative constructs. Structural aspects of self-concept are considered to be significant in the experience of psychological distress and wellbeing, but have been largely overlooked in clinical psychology, and have yet to be considered in the experience of shame. Aim: To explore the relationships between shame memories containing traumatic and centrality features, current experiences of shame, a structural component of self-concept in the form of self-concept clarity, and psychological distress and wellbeing. Method: Participants (n = 220), ranging from 18-63 years (M = 32.03, SD = 10.82) completed questionnaires online pertaining to the characteristics of a shame memory they recalled, current experiences of external and internal shame, self- concept clarity, self-esteem, psychological distress, and wellbeing. One hundred and five participants (46.47%) had received a range of psychiatric diagnoses, and a further thirty-two (14.54%) experienced self-reported psychological distress. Results: Shame memories containing traumatic and centrality features were significantly associated with shame and distress. Shame memories containing traumatic features was a significant predictor of psychological distress and wellbeing. Participants who recalled a shame memory involving an attachment figure reported significantly more traumatic and centrality features, higher external and internal shame, and lower self-esteem and wellbeing, compared to those who recalled a shame memory involving a non-attachment figure. Significant and moderate associations were found between self-concept clarity, shame memories, and shame. Self-concept clarity, however, was not a significant predictor of psychological distress and wellbeing, whilst self-esteem was. Conclusions: The findings suggested that self-esteem could be more useful to consider than self-concept clarity in the experience of shame. However, this could have been influenced by the measures used. A number of tentative clinical implications can be drawn from the study including the importance of assessing the key details of shame memories (e.g., who the individual felt shamed by), and actively attending to wellbeing and distress within assessments and interventions for high levels of shame. The importance of preventative interventions in reducing shaming experiences within public health initiatives and educational settings was also demonstrated

Extensional viscosity of copper nanowire suspensions in an aqueous polymer solution

Suspensions of copper nanowires are emerging as new electronic inks for next-generation flexible electronics. Using a novel surface acoustic wave driven extensional flow technique we are able to perform currently lacking analysis of these suspensions and their complex buffer. We observe extensional viscosities from 3 mPa$\cdot$s (1 mPa$\cdot$s shear viscosity) to 37.2 Pa$\cdot$s via changes in the suspension concentration, thus capturing low viscosities that have been historically very challenging to measure. These changes equate to an increase in the relative extensional viscosity of nearly 12,200 times at a volume fraction of just 0.027. We also find that interactions between the wires and the necessary polymer additive affect the rheology strongly. Polymer-induced elasticity shows a reduction as the buffer relaxation time falls from 819 to 59 $\mu$s above a critical particle concentration. The results and technique presented here should aid in the future formulation of these promising nanowire suspensions and their efficient application as inks and coatings.Comment: 7 pages, 5 figures, under review for Soft Matter RS

Order in the Court: How Firm Status and Reputation Shape the Outcomes of Employment Discrimination Suits

This article explores the mechanisms by which corporate prestige produces distorted legal outcomes. Drawing on social psychological theories of status, we suggest that prestige influences audience evaluations by shaping expectations, and that its effect will differ depending on whether a firm’s blameworthiness has been firmly established. We empirically analyze a unique database of more than 500 employment discrimination suits brought between 1998 and 2008. We find that prestige is associated with a decreased likelihood of being found liable (suggesting a halo effect in assessments of blameworthiness), but with more severe punishments among organizations that are found liable (suggesting a halo tax in administrations of punishment). Our analysis allows us to reconcile two ostensibly contradictory bodies of work on how organizational prestige affects audience evaluations by showing that prestige can be both a benefit and a liability, depending on whether an organization’s blameworthiness has been firmly established

Good Firms, Good Targets: The Relationship Among Corporate Social Responsibility, Reputation, and Activist Targeting

Much research on social movements and organizations contends that there is an empirical link between activists\u27 contentious activity and corporate social responsibility (CSR; e.g., Bartley 2007; Campbell 2007; Soule 2009). Typically, we assume that activists influence firms\u27 CSR practices directly. Activists target corporations in order to pursue their social change agendas, hoping to influence those companies to change their policies or practices (King and Pearce 2010). Targeting corporations give activists a way to directly address their grievances and influences a firm to amend an undesirable practice (King and Soule 2007; Walker, Martin, and McCarthy 2008; Lenox and Eesley 2009). For example, if a retail firm regularly sources its products from manufacturers that employ sweatshop labor, activists may raise concerns about this inflammatory practice by protesting the firm boycotting it. Getting in the activists\u27 spotlight puts public pressure on firms to change their practices, especially inasmuch as movement tactics draw unwanted negative attention from the media that could influence the public\u27s perceptions about a firm\u27s level of social responsibility (King 2008, 2011; Bartley and Child 2011)