Nitrogen fixation is currently of great practical importance because the use of nitrogenous fertilizers has resulted in unacceptable levels of water pollution and the fact that these fertilizers are becoming steadily less economic both in cash terms and in utilization of fossil fuels for their manufacture. This book aims to present new findings in the field of nitrogen fixation and to reflect the influence on the subject of recent developments in biochemistry, molecular biology, genetic engineering and other biotechnologies. The book includes quantitative aspects of the subject, but the many practical difficulties for accurate field assessment of nitrogen fixation and its contribution to nitrogen cycles means that many assessments are either in conflict with each other or must be accepted as tentative. Although this book is concerned essentially with how nitrogen-fixing organisms function and why they are of practical importance, rather than with details of laboratory or field techniques, an appendix deals with the main methods of measurement of nitrogen fixation and some of the problems that must be faced.

Now more than ever before, today's schools are hazard zones. Students are vulnerable to attack from other students and random individuals who may appear to be harmless on the surface or who may be sending out warning signals. Either way, to save their lives or protect themselves from injury, they must be prepared. Now in its second edition, Staying Safe at School is a guidebook that every parent and school administrator should make available to students. Concise and practical, this book will show teenagers how to: Perform a risk assessment to determine if they should feel threatened Recognize the troublemakers and prevent trouble Know what to do in a crisis, and more importantly, what not to do Improve their chances of survival if they become victimized Make changes in their lifestyles that will reduce their risk of being victimized Force criminals and bullies to alter their plans against their victims Face fear and learn how to control it Work with other students, teachers, counselors, and administrators to increase the safety of all Bullies and other school predators will always exist in one form or another. But students can take steps to make themselves less likely to be victimized. Using anecdotes and examples to demonstrate concepts, this volume provides important survival tips and gives students the confidence they need to protect themselves and feel safe in dangerous situations.

This is a practical guide to all aspects of writing about science and technology. It features useful hints on how to make each kind of writing more attractive to the target readership. It also includes detailed advice on how to approach publishers, publishers' contracts and requirements and the author's role at each stage of book production, including tips on presentation of manuscripts on disc or as camera-ready copy. There is clear guidance on the best way to use tables, graphs and diagrams and on how to present formulae and choose examples and exercises. Advice is given for overcoming the often neglected problem of catering for users with widely different technical backgrounds when writing instruction manuals. Careful preparation is given to the preparation of research and technical reports and writing for the media. The problems facing authors writing in English when this is not their first language are also tackled. This book should be of interest to lecturers, teachers, research workers, senior technicians in the fields of science, engineering, medicine, social sciences; senior scientific and technical staff in industry; senior management in firms involved either in research