923 research outputs found
Lattice dynamics and correlated atomic motion from the atomic pair distribution function
The mean-square relative displacements (MSRD) of atomic pair motions in
crystals are studied as a function of pair distance and temperature using the
atomic pair distribution function (PDF). The effects of the lattice vibrations
on the PDF peak widths are modelled using both a multi-parameter Born
von-Karman (BvK) force model and a single-parameter Debye model. These results
are compared to experimentally determined PDFs. We find that the near-neighbor
atomic motions are strongly correlated, and that the extent of this correlation
depends both on the interatomic interactions and crystal structure. These
results suggest that proper account of the lattice vibrational effects on the
PDF peak width is important in extracting information on static disorder in a
disordered system such as an alloy. Good agreement is obtained between the BvK
model calculations of PDF peak widths and the experimentally determined peak
widths. The Debye model successfully explains the average, though not detailed,
natures of the MSRD of atomic pair motion with just one parameter. Also the
temperature dependence of the Debye model largely agrees with the BvK model
predictions. Therefore, the Debye model provides a simple description of the
effects of lattice vibrations on the PDF peak widths.Comment: 9 pages, 11 figure
Does resuscitation status affect decision making in a deteriorating patient? Results from a randomised vignette study
Aims and objectives: The aim of this paper is to determine the influence of do not attempt cardiopulmonary resuscitation (DNACPR) orders and the Universal Form of Treatment Options (‘UFTO’: an alternative approach that contextualizes the resuscitation decision within an overall treatment plan) on nurses' decision making about a deteriorating patient. Methods: An online survey with a developing case scenario across three timeframes was used on 231 nurses from 10 National Health Service Trusts. Nurses were randomised into three groups: DNACPR, the UFTO and no-form. Statements were pooled into four subcategories: Increasing Monitoring, Escalating Concern, Initiating Treatments and Comfort Measures. Results: Reported decisions were different across the three groups. Nurses in the DNACPR group agreed or strongly agreed to initiate fewer intense nursing interventions than the UFTO and no-form groups (P < 0.001) overall and across subcategories of Increase Monitoring, Escalate Concern and Initiate Treatments (all P < 0.001). There was no difference between the UFTO and no-form groups overall (P = 0.795) or in the subcategories. No difference in Comfort Measures were observed (P = 0.201) between the three groups. Conclusion: The presence of a DNACPR order appears to influence nurse decision making in a deteriorating patient vignette. Differences were not observed in the UFTO and no-form group. The UFTO may improve the way nurses modulate their behaviours towards critically ill patients with DNACPR status. More hospitals should consider adopting an approach where the resuscitation decisions are contextualised within overall goals of care
Psychological and Environmental Correlates of HPA Axis Functioning in Parentally Bereaved Children: Preliminary Findings
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97514/1/jts21788.pd
Peak positions and shapes in neutron pair correlation functions from powders of highly anisotropic crystals
The effect of the powder average on the peak shapes and positions in neutron
pair distribution functions of polycrystalline materials is examined. It is
shown that for highly anisotropic crystals, the powder average leads to shifts
in peak positions and to non-Gaussian peak shapes. The peak shifts can be as
large as several percent of the lattice spacing
Delays in Leniency Application: Is There Really a Race to the Enforcer's Door?
This paper studies cartels’ strategic behavior in delaying leniency applications, a take-up decision that has been ignored in the previous literature. Using European Commission decisions issued over a 16-year span, we show, contrary to common beliefs and the existing literature, that conspirators
often apply for leniency long after a cartel collapses. We estimate hazard and probit models to study the determinants of leniency-application delays. Statistical tests find that delays are symmetrically affected by antitrust policies and macroeconomic fluctuations. Our results shed light on the design of
enforcement programs against cartels and other forms of conspiracy
European integration assessed in the light of the 'rules vs. standards debate'
The interplay of various legal systems in the European Union (EU) has long triggered a debate on the tension between uniformity and diversity of Member States' (MS) laws. This debate takes place among European legal scholars and is also paralleled by economic scholars, e.g. in the ambit of the 'theory of federalism'. This paper takes an innovative perspective on the discrepancy between 'centralized' and 'decentralized' law-making in the EU by assessing it with the help of the rules versus standards debate. When should the EU legislator grant the national legislator leeway in the formulation of new laws and when should all be fixed ex ante at European level? The literature on the 'optimal shape of legal norms' shall be revisited in the light of law-making in the EU, centrally dealing with the question how much discretion shall be given to the national legislator; and under which circumstances. This paper enhances the established decisive factors for the choice of a rule or a standard in a national setting (complexity, volatility, judges' specialization and frequency of application) by two new crucial factors (switching costs and the benefit of uniformity in terms of information costs) in order to assess law-making policies at EU level
Priority for the Worse Off and the Social Cost of Carbon
The social cost of carbon (SCC) is a monetary measure of the harms from carbon emission. Specifically, it is the reduction in current consumption that produces a loss in social welfare equivalent to that caused by the emission of a ton of CO2. The standard approach is to calculate the SCC using a discounted-utilitarian social welfare function (SWF)—one that simply adds up the well-being numbers (utilities) of individuals, as discounted by a weighting factor that decreases with time. The discounted-utilitarian SWF has been criticized both for ignoring the distribution of well-being, and for including an arbitrary preference for earlier generations. Here, we use a prioritarian SWF, with no time-discount factor, to calculate the SCC in the integrated assessment model RICE. Prioritarianism is a well-developed concept in ethics and theoretical welfare economics, but has been, thus far, little used in climate scholarship. The core idea is to give greater weight to well-being changes affecting worse off individuals. We find substantial differences between the discounted-utilitarian and non-discounted prioritarian SCC
Fairness, envy, guilt and greed: building equity considerations into agency theory
In this article we examine the extent to which fairness considerations are salient to senior executives, and consider the implications for agency theory, tournament theory and the design of top-management incentives. We look for patterns in a unique data set of senior executive preferences and seek explanations for these patterns using a model of fairness first advanced by Fehr and Schmidt in 1999. We propose a number of amendments to Fehr and Schmidt’s model. We challenge some of the standard tenets of agency theory and tournament theory, demonstrating why equity considerations should be taken into account. We add to the growing literature on behavioural agency theory
- …