This book has been prepared for those seeking a better understanding of the functioning of crop plants, particularly the processes that lead to the genera tion of products valued by human beings. The contributors, who are among the world's foremost experts on the important crops upon which humanity depends for food or fibre, address the relevant processes for their specific crop. Currently, the world population is continuing to increase. It is projected to plateau around the middle of the next century, and while there is considerable controversy regarding the population level when this plateau is achieved, most estimates are in the area of 10 000 000 000. At present, there are about 800000000 people in the world who do not have secure access to food. Over the last 50 years various aspects of agricultural research have been combined to increase the output of world crops approximately 2.5-fold. Given the need to feed the increasing population, and to provide better access, it is predicted that during the next 50 years the agricultural research community must repeat this achievement."

The tomato is commercially important throughout the world both for the fresh fruit market and the processed food industries. It is grown in a wide range of climates in the field, under protection in plastic greenhouses and in heated glasshouses. Genetic, physiological and pathological investigations frequently adopt the tomato plant as a convenient subject. Hitherto, much of the information on tomatoes has been fragmented: tomatoes grown in the field and under protection have been considered separately and the more fundamental findings from research have often failed to reach those involved directly or indirectly in commercial crop production. Similarly, the research scientist is often unaware of the problems of commercial crop production and the possible relevance of his work to the crop. This book is an attempt to rectify that situation. By giving a thorough scientific review of all factors influencing tomato production systems, it is hoped that this book will prove useful to students, researchers and commercial producers alike. It gives the basis for the develop ment of improved cultivars, the formulation of strategies for managing pest, disease and disorder problems and the production of high yields of good quality fruit as well as suggesting important areas for scientific initiatives. The extensive bibliographies provide a comprehensive database for tomato researchers. Such a vast subject could not be covered with authority by anyone author."

In the conflict between logging as a material resource and preservation the forests are becoming depleted throughout the world and this depletion is aggravated by the effects of air pollution. The concept of utilization is thus now being expanded to include vital societal values. These issues are nowhere more acute than in Central and Eastern Europe, where obsolete, poorly maintained industrial plant is common. Air pollutant levels are so high that one area has been called the Black Triangle. Timber is required in this region as a building material and logging for fuelwood is practised, giving rise to a complex linkage between industry, energy supply, deforestation, agriculture, value-added forestry products and economic development. This book presents current information on national and regional issues relating to environmental threats to forest land, focusing on: ecology, environment and science; forest ownership and management; forest product utilization; government and public agency roles. The recommendations, action items and the human network needed for regional-level implementation are detailed in `situation', `position' and `state of the art' papers. The final objective is to develop a plan of action to help abate the negative impacts while sustaining or expanding the forests, the economy and the energy sufficiency of the region.

Soils form a unique and irreplaceable essential resource for all terrestrial organisms, including man. Soils form not only the very thin outer skin of the earth's crust that is exploited by plant roots for anchorage and supply of water and nutrients. Soils are complex natural bodies formed under the influence of plants, microorganisms and soil animals, water and air from their parent material, i.e. solid rock or unconsolidated sediments. Physically, chemically and mineralogically they usually differ strongly from the parent material, and normally are far more suitable as a rooting medium for plants. In addition to serving as a substrate for plant growth, including crops and pasture, soils play a dominant role in the biogeochemical cycling of water, carbon, nitrogen and other elements, influencing the chemical composition and turnover rates of substances in the atmosphere and the hydrosphere. Soils take decades to millennia to form. We tread on them and do not usually see their interior, so we tend to take them for granted. But improper and abusive agricultural management, careless land- clearing and reclamation, man-induced erosion, salinisation and acidification, desertification, air- and water pollution, and withdrawal of land for housing, industry and transportation now destroy soils more rapidly than they can be formed.

Jointly published with INRA, Paris.
What will people eat in the future and how can the food requirements in terms of quantity and quality be met? This EU-based study elucidates the need for a productivity level that will make agriculture competitive on the market and yet is reconciled with the need to manage natural resources and lands wisely. In this book the necessary changes for European agriculture from the biological, medical, economic and political perspective are discussed.

For the identification of a flowering plant the first step usually is to discover to which family it belongs. With some experience, the families commonly encountered in one's area of interest are soon known, but when dealing with specimens from other places, notably those from the vast and rich subtropics and tropics, there is much less certainty. The pertinent literature is often not readily available as it is often found only in expensive, rare or obscure books, or journals, present only in a few specialized institutes. Basically only a few keys to the families of flowering plants of the world have ever been produced, the best known of which at present is Hutchinson's Key to the families of flowering plants (1973); less well-known are Lemee's Tableau analytique des genres monocotyledones (1941) (incl. Gymnosperms) and his Tableau analytique des genres dicotyledones (1943), and Hansen and Rahn's Determination of Angiosperm families by means of a punched-card system (Dansk Bot. Ark. 26, 1969, with additions and corrections in Bot. Tidsskr. 67, 1972, 152-153, and Ibid. 74 1979, 177-178). Of note also are Davies and Cullen's The identification of flowering plant families, 2nd ed. (1979), which, however, deals only with the families native or cultivated in North Temperate regions, and Joly's Chaves de identifi iio das familias de plantas vasculares que ocorrem no Brasil, 3rd ed. (1977), which may be useful in other tropical areas too.

In the early seventies, scientists in Israel and The Netherlands started a cooperative project on actual and potential production under semi-arid conditions. In Israel research concentrated on primary production of natural pastures and small grain crops, and on the associated secondary production of small ruminants. Most of the experimental work was carried out at the Migda Experimental Farm in the semi-desert of the northern Negev where the long term average annual rainfall is 250 mm. In The Netherlands existing facilities in Wageningen were used for measuring growth, photosynthesis and transpiration of Negev pasture plants and small grains under controlled conditions, both as individual plants and as simulated swards and crops. The joint research program was initiated by the late N.H. Tadmor and A. Dovrat from Israel and by C.T. de Wit and Th. Alberda from The Netherlands and conducted by various scientists from both countries, some of whom are among the authors of this book. The experimental results first served as a basis for the development, calibration and validation of simulation models of the growth and water use of pasture and crops. Subsequently, additional models were developed, allowing incorporation of socio-economic considerations, both at the farm and regional level, so harnessing the research results for analysis of regional development possibilities."

As biotechnology produces an unprecedented number of new plantvarieties, automated transplant production systems offer the means for their large-scale introduction via a rapid, efficient and economic method. As labour costs increase, so will automated systems assume even greater importance. Reforestation and afforestation projects, anti-des-ertification plantings and an increasing demand for urban greenery also create enormous demands for the mass production of high quality transplants, in addition to the commercial needs of the agriculture industry. The application of engineering techniques to modern micropropagation techniques and plant production means that many tasks can be automated, especially physical manipulation and close control of the microenvironment. This volume provides overviews of the main con-cepts -- plug seedling production, micropropagation, robotization, model development, measurement and environmental control -- with an emphasis on practical considerations. Examples are drawn from flower, vegetable and forest tree species to show how disciplines such as robotics and image analysis have a part to play in plant production.

The overarching contribution of this book is a review and assessment of the current and future impacts of globalization on the world's forests. The work has been developed by the "Resources for the Future" Task Force for the International Union of Forest Research Organizations (IUFRO). Four key themes are addressed: the effect of globalization on forests (including future trade flows); plantations as the primary source of forest products and its consequences, including plant breeding and forest health; the effect of new products such as bio-products and markets on forests; and the emergence of forest ecosystem services and their impact on the landscape and human communities. These four themes are examined in detail to map out the impacts of these trends for forests throughout the world and at multiple scales, and how forest research needs to be adapted to address these trends. Overall, the volume provides a major synthesis of current thinking and knowledge on the topic for advanced students, as well as policy-makers and professionals in the forest sector.

"The book is very effective in communicating the many aspects, dimensions and interpretations of sustainable forest management (SFM)...It is clearly born out of an ambitious remit to present an overview of SFM across all its dimensions. In this, it is by and large successful... It provides an effective entry into almost any SFM topic." Review in Scottish Forestry by Professor Jaboury Ghazoul, ETH Zurich/University of Edinburgh "Achieving Sustainable Management of Tropical Forests provides an excellent and essential read for those with responsibility for managing the world's tropical forests...The editors, Dr Blaser and Dr Hardcastle, are to be congratulated for editing the chapters into a very consistent read... Each chapter is authored by an expert or experts in the particular geography and/or discipline as social, governance, tenure, biology, rural livelihoods, climate change, products etc." Journal of Forestry - Society of American Foresters Although global rates of deforestation have started to decrease, they remain alarmingly high in many tropical countries. In light of this challenge, the growing importance of sustainable forest management (SFM) has been highlighted as a means for improving sustainability across the sector. Achieving sustainable management of tropical forests summarises and reviews the rich body of research on tropical forests and how this research can be utilised to make sustainable management of tropical forests a standard implementable strategy for the future. The book features expert discussions on the economic, political and environmental contexts needed for SFM to operate successfully, including coverage of the UN's Sustainable Development Goals (SDGs). With its distinguished editors and international array of expert authors, Achieving sustainable management of tropical forests will be a standard reference for researchers in tropical forest science, international and national organisations responsible for protection and responsible stewardship of tropical forests, as well as the commercial sector harvesting and using tropical forest products.

Gene Transfer to Plants Within a decade of the first recoveries of transgenic "model" plants, gene trans- fer is an established and routine technique in numerous laboratories around the world. It contributes to the rapid progress in basic and applied plant sciences in disciplines as diverse as biochemistry, physiology, developmental biology, breeding, food sciences, and biotechnology (Lindsey 1992; Willmitzer and Topfer 1992; Kishore and Somerville 1993; Nessler 1994). Following years of unsuccessful experiments with variations in feeding iso- lated DNA to plant tissues and organs, gene transfer became a reality soon after it was discovered that the soil bacterium Agrobacterium tumefaciens contained a plasmid, part of it being transferred to competent plant cells (see Hooykaas; Introduction I: Agrobacterium tumefaciens, a natural vector system). Host range limitations of Agrobacterium-mediated gene transfer prompted the search for alternative gene transfer systems, leading soon to the development of "direct gene transfer to protoplasts" (see Potrykus; Introduction III: Direct gene trans- fer to protoplasts). Further limitations in both gene transfer systems led to the exploration of a great variety of further approaches such as pollen transforma- tion, pollen tube pathway, electrophoresis, microlaser, liposome-fusion and -injection, macroinjection, direct DNA application in numerous variations, etc. None of these approaches has, so far, been developed to a reproducible gene transfer technique and it is questionable whether they ever led to transformation (for a detailed assessment see Potrykus 1990).

Modern Methods of Plant Analysis When the handbook Modern Methods of Plant Analysis was first introduced in 1954 the considerations were: 1. the dependence of scientific progress in biology on the improvement of ex isting and the introduction of new methods; 2. the difficulty in finding many new analytical methods in specialized jour nals which are normally not accessible to experimental plant biologists; 3. the fact that in the methods sections of papers the description of methods is frequently so compact, or even sometimes so incomplete that it is dif ficult to reproduce experiments. These considerations still stand today. The series was highly successful, seven volumes appearing between 1956 and 1964. Since there is still today a demand for the old series, the publisher has decided to resume publication of Modern Methods of Plant Analysis. It is hoped that the New Series will be just as acceptable to those working in plant sciences and related fields as the early volumes undoubtedly were. It is difficult to single out the major reasons for success of any publication, but we believe that the methods published in the first series were up-to-date at the time and presented in a way that made description, as applied to plant material, com plete in itself with little need to consult other publications. Contribution authors have attempted to follow these guidelines in this New Series of volumes."

This book, prepared by participants of the European network COST ACTION 810 (1989-93) is the outcome of a meeting held in Switzerland (Einsiedeln, September 29 to October 2, 1993) on the "Impact of arbuscular mycorrhizas on sustainable agriculture and natural ecosystems". COST(Cooperation Scientifique et Technique) Networks were created in 1971 by the Commission of European Communities, and later enlarged to include non-European Member States, to promote pre-competitive scientific and technical research in fields of common interest. During the eighties, COST ACTIONS were launched in bio technological fields, including the network on arbuscular mycorrhizas. Arbuscular mycorrhizas are a universally found symbiosis between plants and certain soil fungi and essential components of soil-plant systems. They act as a major inter face by influencing or regulating resource allocation between abiotic and biotic components of the soil-plant system. Arbuscular mycorrhizas are involved in many key ecosystem processes including nutrient cycling and conservation of soil struc ture, and have been shown to improve plant health through increased protection against abiotic and biotic stresses. Sustainability can be defined as the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality of the environ ment and conserving resources. Increasing environmental degradation and instability, due to anthropogenic activities and in particular the increasing fragility of the soil resource, has led to an increased awareness of the need to develop practices resulting in more sustainable natural and agroecosystems.

Insect pest control has continuously evolved from inorganics to botanicals, to chlo- rinated hydrocarbons, to organophosphorus compounds and methylcarbamates, then synthetic pyrethroids and most recently synthetic nicotinoids as the major classes. These insecticides allowed high standards of crop protection at minimal cost. A limitation in each new class of compounds is the selection of resistant strains and ultimate control failures and this serves as a driving force to discover and develop replacement compounds to circumvent resistance and overcome problem areas. The nicotinoids now play a critical role in meeting this need. Three generations of chemicals are involved in the history of nicotinoid insecti- cides. The first generation was the botanical nicotine used for at least three centuries to control sucking insect pests but largely replaced in the 1940s and 1950s by the more effective organophosphorus compounds and methylcarbamates, some with systemic properties. Synthesis programs based on nicotine as a prototype did not yield compounds that could compete with other synthetic insecticides. The second generation was the nitromethylene type such as nithiazine, discovered by Shell sci- entists in a screening/optimization program. The nitromethylenes had the potency, selectivity, and systemic properties but lacked the field effectiveness largely because of photolability (so close yet so far from a major commercial product). The third generation required a series of advances made by Bayer researchers starting from nithiazine as the model and enhancing its photostability and potency with a nitroimine and chloropyridyl moiety, respectively, to give imidacloprid, the subject of much of this monograph.

With tens of millions of hectares and hundreds of millions of lives in the balance, the debate over who should control South Asia s forests is of tremendous political significance. This book provides an insightful and thorough assessment of important forest management transitions currently underway. MARK POFFENBERGER, EXECUTIVE DIRECTOR OF COMMUNITY FORESTRY INTERNATIONAL The contributions in this volume not only breathe life into the fi eld of writing and analysis related to forests, they do so on the strength of extraordinarily insightful research. Kudos to Springate-Baginski and Blaikie for providing us with a set of thoroughly researched, provocative studies that should be required reading not only for those interested in community forestry in south Asia, but in resource governance anywhere. ARUN AGRAWAL, ASSOCIATE PROFESSOR OF NATURAL RESOURCES & ENVIRONMENT, UNIVERSITY OF MICHIGAN, USA Makes a significant contribution to theory and practice of participatory forest management. YAM MALLA, EXECUTIVE DIRECTOR, REGIONAL COMMUNITY FORESTRY TRAINING CENTER FOR ASIA AND THE PACIFIC, BANGKOK This excellent and timely book provides thought-provoking insights to the issues of power and politics in forestry and the difficulties of transforming age-old structures that circumscribe the access of the poor to forests and their resources; it challenges our assumptions of the benefits of participatory forest management and the role of forestry in poverty reduction. It should be of interest to policy-makers and to all those who have been involved with the struggle of transforming forestry over the decades. DR MARY HOBLEY, HOBLEY SHIELDS ASSOCIATES (NATURAL RESOURCE MANAGEMENT AND PLANNING CONSULTANCY) A rare combination of extensive field study, social science insights and policy studies will be of immense value DR N. C. SAXENA, MEMBER OF NATIONAL ADVISORY COUNCIL, GOVERNMENT OF INDIA In recent decades participatory approaches to forest management have been introduced around the world. This book assesses their implementation in the highly politicized environments of India and Nepal. The authors critically examine the policy, implementation processes and causal factors affecting livelihood impacts. Considering narratives and field practice, with data from over 60 study villages and over 1000 household interviews, the book demonstrates why particular field outcomes have occurred and why policy reform often proves so difficult. Research findings on which the book is based are already influencing policy in India and Nepal, and the research and analysis have great relevance to forestry management in a wide range of countries. Published with DFID."

For the past decade, it has been apparent to both of us that a reference text covering all aspects of tree defense mechanisms to fungi was missing, needed and long overdue. Such a book would provide a clear, comprehensive overview of how living roots, stems and leaves respond to fungal pathogens. The need for such a book became in creasingly clear to us from our conversations with each other, as well as from our interactions with students and colleagues who desired a sourcebook containing reviews of morphological, biochemical and physiological aspects of host-parasite interactions in trees. During a field trip sponsored by the Forest Pathology Committee of the Ameri can Phytopathological Society, on a bus from one site to another, we decided to take the responsibility to prepare a book of this type and began to plan its composition. To adequately address the topic of this book as we had envisioned it, we believed that well-illustrated chapters were needed in order to reflect the important advances made by the many investigators who have examined the anatomical and physiological changes that occur when trees are attacked by fungi. We are grateful to Dr. Tore Timell, the Wood Science editor for Springer-Verlag, for supporting our efforts and for providing an avenue to publish such a profusely il lustrated volume."

Plantations of a wide range of tree species have assumed an important place in our world, providing wood for industry, fuelwood and animal fodder, protection from adverse environments and for the soil, as well as amenity and aesthetically pleasing landscapes. silvicultural knowledge of this particular branch of forestry first developed in Europe more than two centuries ago but in many parts of the world is still in a process of rapid evolution as more and more plantations are established to meet specific needs. The first exotic tree species to be established in plantations in my own country were planted more than a century ago and, likewise, New Zealand has a long history of planting. Both countries have developed a vigorous and innovative approach to plantation practice, soundly based initially on European experience but gradually modified to meet the challenges of new environments, new markets, and changed economic circumstances. This book on plantation silviculture was begun some years ago when the lack of a suitable undergraduate text for teaching purposes became apparent. The present text is aimed essentially at this audience. Although I have drawn heavily on the experience of Australia and New Zealand, the principles outlined are applicable anywhere in the world where plantations are being grown and tended, from the United States and Scandinavia to India, South Africa or Brazil. The text should also serve as a useful reference to advanced students and practicing foresters, with the reference list providing an introduction to the literature on this subject.

Within the extreme diversity of aquatic and terrestrial plant genera, each has characteristic cell wall forms. A number of hypotheses have been advanced to explain differences in microfibril arrangements across anyone such wall. Of those, only the 'multinet' theory, which involves the postulation of reorientation of microfibrils caused by cell extension, now has a substantial number of ad herents. However, many scientists are sceptical of its validity; obviously it is incompatible with various observed microfibril arrangements. The tenet of this study is that any such hypothesis can be valid only if it is applicable to all plant forms and wall types. Initially, reanalyses are made of data claimed to confirm justification for multi net postulations. The results show that previous deductions from those data, in support of multinet, are subject to serious challenge. Similarly, a re-examination of the observations, which inspired the multinet theory, shows they have a more logical explanation. Herein, it is concluded that cell wall development involves biophysical factors, which neces sarily prevent multinet's postulated large reorientations of microfibrils, after their formation. Unfortunately the previously most recent published theory, which is based on the absence of reorientation during extension, fails to answer the fundamental question of how alternating orientations between lamellae are controlled, or explain variations in thickness of wall layers. Extensive published data are used to identify forces involved in cell wall development.

Thrips (fhysanoptera) are very small insects, widespread throughout the world with a preponderance of tropical species, many temperate ones, and even a few living in arctic regions. Of the approximately 5,000 species so far identified, only a few hundred are crop pests, causing serious damage or transmitting diseases to growing crops and harvestable produce in most countries. Their fringed wings confer a natural ability to disperse widely, blown by the wind. Their minute size and cryptic behavior make them difficult to detect either in the field or in fresh vegetation transported during international trade of vegetables, fruit and ornamental flowers. Many species have now spread from their original natural habitats and hosts to favorable new environments where they often reproduce rapidly to develop intense damaging infestations that are costly to control. Over the past decade there have been several spectacular examples of this. The western flower thrips has expanded its range from the North American continent to Europe, Australia and South Africa. Thrips palmi has spread from its presumed origin, the island of Sumatra, to the coast of Florida, and threatens to extend its distribution throughout North and South America. Pear thrips, a known orchard pest of Europe and the western United States and Canada has recently become a major defoliator of hardwood trees in Vermont and the neighboring states. Local outbreaks of other species are also becoming problems in field and glasshouse crops as the effectiveness of insecticides against them decline.

This book integrates the latest global developments in forestry science and practice and their relevance for the sustainable management of tropical forests. The influence of social dimensions on the development of silvicultural concepts is another spotlight. Ecology and silvicultural options form all tropical continents, and forest formations from dry to moist forests and from lowland to mountain forests are covered. Review chapters which guide readers through this complex subject integrate numerous illustrative and quantitative case studies by experts from all over the world. On the basis of a cross-sectional evaluation of the case studies presented, the authors put forward possible silvicultural contributions towards sustainability in a changing world. The book is addressed to a broad readership from forestry and environmental disciplines.

This book was tbe result of a symposium beld at tbe American Cbernical Society meeting in Miami Beacb, Florida, September 10-15, 1989. The symposium was jointly sponsored by Tbe Society for Economfc Botany and tbe American Cbernical Society Food and Natural Product sub division. Tbere were five speakers. During tbe social sessions (mostly over drinks in abotel room), it became obvious tbat, regardless of tbe discipline, we were all speaking tbe same language. Yet, prior to tbe symposium, only a few of tbe participants knew one anotber. We decided to expand tbe symposium into a book. The book would, we boped, accomplish for otbers wbat we bad discovered in ourselves. That is, the field of Natural Products is broad, but similar in techniques and approach, ancient but modern, and bas been and continues to be extremely valuable to humankind. We wanted the book to serve as an introductory text for courses and as a reference work for the future. We also determined to include the structure of every chemical in the chapter where it was mentioned so the reader would not have to find the structure somewhere else or to try and deduce the structure from the chemical name. Little did we know what an undertaking these goals would be or the time this would take.

As forests decline in temperate and tropical climates, highly-developed countries and those striving for greater economic and social benefits are beginning to utilize marginal forests of high-latitude and mountainous regions for resources to satisfy human needs. The benefits of marginal forests range from purely aesthetic to providing resources for producing many goods and services demanded by a growing world population. Increased demands for forest resources and amenities and recent warming of high latitude climates have generated interest in reforestation and afforestation of marginal habitats in cold regions. Afforestation of treeless landscapes improves the environment for human habitation and provides for land use and economic prosperity. Trees are frequently planted in cold climates to rehabilitate denuded sites, for the amenity of homes and villages, and for wind shelter, recreation, agroforestry, and industrial uses. In addition, forests in cold climates reduce the albedo of the earth's surface in winter, and in summer they are small but significant long-lived sinks for atmospheric carbon dioxide. Finally, growth and reproductive success of forests at their geographic limits are sensitive indices of climatic change. As efforts to adapt forests to cold climates increase, however, new afforestation problems arise and old ones intensify. Austral, northern, and altitudinal tree limits are determined by many different factors. Current hypotheses for high-latitude tree limits are based on low growing-season temperatures that inhibit plant development and reproduction.

DeFelice presents this intricate subject in an easy-to-follow, stepwise fashion: he reviews the fundamentals of electricity; transfers those principles to a biological context; and expands the discussion to encompass the subject's practical dimensions. Clear definitions and intuitive descriptions characterize the presentation, which is complemented by over 150 drawings and graphs. Mathematics is kept to the minimum necessary. The text covers both excitable and non-excitable membranes and includes the plasma membrane as well as intracellular membranes. A unique, 'electronics-made-simple' appendix, designed specifically for biologists, treats the operational amplifiers used in patch clamp, and other appendices offer solutions to equations and examples that illustrate principles.

S. Henin Versailles, France It was a pleasure for me to take part in the NATO Advanced Study Workshop for studies of 'Soil Colloids and their Associations in Soil Aggregates'. The meeting provided me with a welcome opportunity to renew acquaintances with respected colleagues in the various fields of Soil Science, to listen to their presentations, and be involved in discussions which were at the frontiers of the science which deals with the structures and the associations of the soil colloidal constituents. In my view the rapid advances in Soil Science, and the great benefits to agriculture from these, have their origins in the emerging understanding of the structures and the associations of the different soil colloids. It is clear that much research is still needed before the molecular details of the most important of the structures and of the interactions are fully understood. The associations between the soil colloids, and the manner in which they bind to or hold the other constituents of soils in aggregates is fundamental to soil fertility. and the Modem intensive agriculture leads to the degradation of soil structure subsequent loss through erosion of a resource that is vital for the production of food. This degradation is considered to result primarily from the biological oxidation of the indigenous soil organic matter, and from the failure to return to the soil sufficient organic residues to compensate for such losses.