French literature, from 1945 to 1999

pp. 181-204

Fractal species distributions do not produce power-law species-area relationships

We derive the species-area relationship (SAR) expected from an assemblage of fractally distributed species. If species have truly fractal spatial distributions with different fractal dimensions, we show that the expected SAR is not the classical power-law function, as suggested recently in the literature. This analytically derived SAR has a distinctive shape that is not commonly observed in nature: upward-accelerating richness with increasing area (when plotted on log-log axes). This suggests that, in reality, most species depart from true fractal spatial structure. We demonstrate the fitting of a fractal SAR using two plant assemblages (Alaskan trees and British grasses). We show that in both cases, when modelled as fractal patterns, the modelled SAR departs from the observed SAR in the same way, in accord with the theory developed here. The challenge is to identify how species depart from fractality, either individually or within assemblages, and more importantly to suggest reasons why species distributions are not self-similar and what, if anything, this can tell us about the spatial processes involved in their generation.

Ethical issues experienced by healthcare workers in nursing homes: Literature review

BACKGROUND: Ethical issues are increasingly being reported by care-providers; however, little is known about the nature of these issues within the nursing home. Ethical issues are unavoidable in healthcare and can result in opportunities for improving work and care conditions; however, they are also associated with detrimental outcomes including staff burnout and moral distress.

OBJECTIVES: The purpose of this review was to identify prior research which focuses on ethical issues in the nursing home and to explore staffs' experiences of ethical issues.

METHODS: Using a systematic approach based on Aveyard (2014), a literature review was conducted which focused on ethical and moral issues, nurses and nursing assistants, and the nursing home.

FINDINGS: The most salient themes identified in the review included clashing ethical principles, issues related to communication, lack of resources and quality of care provision. The review also identified solutions for overcoming the ethical issues that were identified and revealed the definitional challenges that permeate this area of work.

CONCLUSIONS: The review highlighted a need for improved ethics education for care-providers.

SIMLA: Simulating particle dynamics in intense laser and other electromagnetic fields via classical and quantum electrodynamics

We present the Fortran program SIMLA, which is designed for the study of charged particle dynamics in laser and other background fields. The dynamics can be determined classically via the Lorentz force and Landau–Lifshitz equations or, alternatively, via the simulation of photon emission events determined by strong-field quantum-electrodynamics amplitudes and implemented using Monte-Carlo routines. Multiple background fields can be included in the simulation and, where applicable, the propagation direction, field type (plane wave, focussed paraxial, constant crossed, or constant magnetic), and time envelope of each can be independently specified.