Ponderous impurities in a Luttinger liquid

In this work, analytical expressions for the Green function of a Luttinger liquid are derived with one and two mobile impurities (heavy particles) using a combination of bosonization and perturbative approaches. The calculations are done in the random phase approximation (RPA) limit using the powerful non-chiral bosonization technique (NCBT) which is nothing but the resummation of the most singular parts of the RPA terms of the Green function expanded out in powers of the forward scattering between fermions with the source of inhomogeneities treated exactly. The force acting on the heavy particle(s) is studied as a function of its terminal velocity, both in the linear and non-linear regime. Linear mobility (which is valid for impurities moving much slower than a certain cross-over speed) has a power-law temperature dependence whose exponent has a closed algebraic expression in terms of the various parameters in the problem. This expression interpolates between the ballistic regime of no-coupling with the fermions and the no-tunneling regime. When the speed of the impurity is much larger than this cross-over speed, the applied force depends non linearly on the speed and this too is a power-law with a closely related exponent. The case of two mobile impurities is also studied whose mobility exhibits peculiar resonances when their mutual separation is appropriately chosen.Comment: Published in EPL (Europhysics Letters) 123.2 (2018): 2700

Nursing Informatics: is IT for All Nurses?

Given the definition if nursing informatics it should be a core activity for all nurses, and seen as a tool to support high quality care giving. Three studies reported in this paper show that this is not the case. Qualified nurses are perceived as having poor skills and knowledge, and as being resistant to IT as it takes them away from patient care. Educators share this lack of knowledge, and neither academics nor students consider nursing informatics to be a clinical skill. In order to use computers while on placement students were found to need confidence in their skills, and to feel that the use of computers was encouraged. Socialisation into the profession is an important part of nurse education, and currently students are being socialised into a professional role where they are not encouraged to use computers, or to consider their use to be a key nursing task. If nursing informatics is to truly become a way of improving patient care this needs to be changed, and preregistration education is a key place to start to bring this change about

Mosaic: Designing Online Creative Communities for Sharing Works-in-Progress

Online creative communities allow creators to share their work with a large audience, maximizing opportunities to showcase their work and connect with fans and peers. However, sharing in-progress work can be technically and socially challenging in environments designed for sharing completed pieces. We propose an online creative community where sharing process, rather than showcasing outcomes, is the main method of sharing creative work. Based on this, we present Mosaic---an online community where illustrators share work-in-progress snapshots showing how an artwork was completed from start to finish. In an online deployment and observational study, artists used Mosaic as a vehicle for reflecting on how they can improve their own creative process, developed a social norm of detailed feedback, and became less apprehensive of sharing early versions of artwork. Through Mosaic, we argue that communities oriented around sharing creative process can create a collaborative environment that is beneficial for creative growth

You Are Special : Shame and Grace in Children\u27s Literature

Children\u27s literature has a profound influence on its readers. It often comes into the home without regard to its content or the effect it can have on a child. This article addresses the broad strokes of child development, how unprocessed or poorly processed shame can hinder the growth of children, books that can be used in the processing of shame, and therapeutic case studies in which these books have been used

Measuring the Common Component of Stock Market Fluctuations in the Asia-Pacific Region

This paper fits Generalized Auto-Regressive Conditional Heteroskedasticity (GARCH) models to the daily closing stock market indices of Australia, China, Hong Kong, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, and Taiwan to compute for time-varying weights associated with the volatilities of individual indices. These weights and the returns of the various indices were then used to determine the common component of stock market returns. Our results suggest that a common component of the Asia-Pacific stock market returns exists, which significantly explains the individual country’s stock market returns. We also find that stock markets of Korea and Hong Kong are the two most sensitive to changes in the common component stock returns, while China’s stock market is the least sensitive.Common Component, Volatility, GARCH model