Positive regularised solutions in electromagnetic inverse scattering

Fredholm integral equations of the first kind are the mathematical model common to several electromagnetic, optical and acoustical inverse scattering problems. In most of these problems the solution must be positive in order to satisfy physical plausibility. We consider ill-posed deconvolution problems and investigate several linear regularization algorithms which provide positive approximate solutions at least in the absence of errors on the data.

Stability Problems in Inverse Diffraction

Inverse diffraction consists in determining the field distribution on a boundary surface from the knowledge of the distribution on a surface situated within the domain where the wave propagates. This problem is a good example for illustrating the use of least-squares methods (also called regularization methods) for solving linear ill-posed inverse problem. We focus on obtaining error bounds For regularized solutions and show that the stability of the restored field far from the boundary surface is quite satisfactory: the error is proportional to ∊(ðŗ‚ ≃ 1) ,ðŗœ being the error in the data (Hölder continuity). However, the error in the restored field on the boundary surface is only proportional to an inverse power of │In∊│ (logarithmic continuity). Such a poor continuity implies some limitations on the resolution which is achievable in practice. In this case, the resolution limit is seen to be about half of the wavelength. Copyright © 1981 by The Institute of Electrical and Electronics Engineers, Inc.

Effect of Bacillus thuringiensis naturally colonising Brassica campestris var. chinensis leaves on neonate larvae of Pieris brassicae

The feeding of neonate larvae of Pieris brassicae (Order Lepidoptera) on leaves of brassica plants that had been colonised by Bacillus thuringiensis resulted in the death of 35% of the population within 72 h. The bacteria Multiplied in the cadavers, resulting in an increase of about 50-fold compared to the living insects. Surviving insects showed no ill effects during the time of the study. There was negligible multiplication of B. thuringiensis in the frass. (C) 2009 Elsevier Inc. All rights reserved.

Understanding changes in cardiovascular pathophysiology

Cardiovascular pathophysiological changes, such as hypertension and enlarged ventricles, reflect the altered functions of the heart and its circulation during ill-health. This article examines the normal and altered anatomy of the cardiac valves, the contractile elements and enzymes of the myocardium, the significance of the different factors associated with cardiac output, and the role of the autonomic nervous system in the heart beat. It also explores how certain diseases alter these functions and result in cardiac symptoms. Nurses can benefit from knowledge of these specific changes, for example, by being able to ask relevant questions in order to ascertain the nature of a patients condition, by being able to take an effective patient history and by being able to read diagnostic results, such as electrocardiograms and cardiac enzyme results. All this will help nurses to promote sound cardiac care based on a physiological rationale.

Foundations for paramedic practice: a theoretical perspective

Written by leading paramedics and academic subject experts, with a foreword by Paul Bates, this is the first foundation level text to introduce the main theoretical subjects studied on the new higher education paramedic science programmes. It underpins practice and links ways of working to the crucial theory base. The numerous examples and case studies focus specifically on pre-hospital and emergency care. Key topics covered include: * NHS and ambulance service history * Ethics and law for the paramedic * Communication and reflective practice * Professional issues, including evidence-based practice, anti-discriminatory practice, clinical governance and clinical audit * Psychological perspectives on health and ill health * Safeguarding children * Sociological perspectives on health and ill health and social policy * Managing change and leadership theory * Continuing professional development The text prompts you to stop and think about what you have just read and relate this to your role. Throughout the book, the author carefully considers how the theory being discussed relates to the role of the ambulance clinician. Foundations for Paramedic Practice: A Theoretical Perspective is a core text for students of paramedic science and will also provide a valuable resource for students of allied health professions. This text provides a stepping stone to further reading and investigation. - Taken from the back cover of: Amanda Blaber - Foundations for paramedic practice: a theoretical perspective