sps apr 2015 (72 risultati)

Taschenbuch. Condizione: Neu. Neuware -In democratic society implementing the equality of possibilities, the aim of education allows to elaborate people's responsibilities and capacities necessary for the realization of individuals' personal functions in society. Modern, educational organization as organizations strive to provide the services of qualitative education and satisfy children's and parents' needs, which are as particular consumers wishes, the conception that something is lacking or everything is good and the expectations are related to desires aimed at perspective. Education and social services indicates the level of educational access.)Access to education is not only the presence of institutions offering general education, but also the fact that it meets the needs of a wide range of education players and the society. Access to education should ensure the justice in the society. This job goal is to explore the quality of educational and social services.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 52 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -This work evaluated the mechanical behavior of structural masonry lintels built with hollow clay blocks. The compressive strength and failure mode of lintels under bending were determine using three different types of lintels: grouted and reinforced lintels made with U section blocks, structural blocks with horizontal prefabricated laying joint reinforcements and horizontal and vertical joint reinforcements with MURFOR® truss and brackets. The test results indicated that the failures occur by shear strength. The use of lintels with grout demonstrated high levels of load strength, when compared with the others models. The use of horizontal and vertical reinforcement (MURFOR®), support higher level of loading, compared with models that had only horizontal reinforced joints.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 104 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Renal function impairment is an important complication of cancer itself and consequences of its treatment such as chemotherapy, radiotherapy and immunotherapy. To minimize renal and non-renal systemic toxicity many anti-neoplatic drugs require dose adjustment based upon glomerular filtration rate (GFR). Renogram using 99mTc-DTPA is one of the commonly used methods to determine GFR. It can also be calculated using many available mathematical equations; Cockcroft-Gault formula, Mayo Quadratic formula, Schwartz formula for children, and Modification of Diet in Renal Disease study (MDRD) equation. MDRD equation is the most popular because of its simplicity and acceptable performance. The aim of the research was to compare the GFR values of the patient using these two different methods and to see the accuracy and sensitivity of MDRD equation to the renogram method for GFR measurement. This project was undertaken at the Nuclear Medicine department of Shaukat Khanum Memorial Cancer Hospital & Research Center, Lahore, Pakistan in collaboration with Institute of Molecular biology and Biotechnology, The University of Lahore, Pakistan.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 120 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The linear dry contact between glass fiber polymer and steel is one of the most complex. It evolves in time as the wear process is under way. From a qualitative point of view, it is known that an increase in friction leads to an increase in wear. This dependency is clarified only in this paper, both qualitatively and quantitatively, because the increase in contact temperature alongside the increase of normal load induces the transfer of plastic material on the wear metal surface, which leads to a modification of the nature of wear. As a result of the filling consisting of short glass fiber, the characteristic of the wear of the metal surface changes constantly, from abrasive to adhesive, abrasive-adhesive, and finally heavily adhesive and corrosive. In order to capture these aspects, a lot of tests are required, microscopic investigations, measurements and interpretations. This paper has the virtue of finding a global qualitative and quantitative method to present this aspect to everybody, succeeding to present the tribological processes that occur in the case of linear dry sliding contact, in their entire complexity.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 144 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 80 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Falls are a worldwide public health problem that mostly affects older people. The prevention of falls can be achieved through multiple factorial interventions, including the educational approach. This guide was developed according to health literacy demands in order to enhance adherence of older people to adopt the behaviors taught and therefore to prevent falls. It can be used by the general public or integrated in a multifactorial programme lead by professionals.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 60 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -This book presents various perceptions as pertains to factors that influence students' enrolment in Technical and Vocational(TV) subjects in Public Secondary schools in Kenya. It suggest that education or training raises the productivity of individuals by imparting useful knowledge and skills in them making the individuals to be useful and productive members of the society. It will therefore helps individuals and corporate groups to be able to asses the bottlenecks facing efforts to equip the youths with practical skills at the Secondary School level.The TV subjects are crucial because they focus on bringing young people into the mainstream of social and economic activity, needs to utilize the opportunities provided by the subjects and prepare them to be competitive in the labour market.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 64 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The book puts before the readers ready-made information on the east, but this time throughout literature and not through political labyrinth. The book concerns wide minded readers particularly students, nature lovers and old people whose minds are still sparkling their ways towards knowledge, and finally it concerns those who love to know about the neighbor east. For these slices of people I humbly pay my respect. The Arab poet previously said: and the best companion in time is a book, and the Koranic verse says: ¿¿and above every (man) owning knowledge is One Who is Ever-Knowing¿ (Yusuf 76). The book shows man¿s inability to live all alone wherever he is. In this context William Shakespeare¿s approach comes, the thing which reflects the strong brotherhood of man on any particular piece of land he is, such as the East which has the lion¿s share in his production. The book shows nature where man dwells in its two sides - from the one side it is a dumb enemy of man as seen by Thomas Hardy and from the other side it is mild and beautiful as it is seen by William Wordsworth the poet of nature.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 128 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -This book examines formal peculiarity of four contemporary novels and argues that they structurally simulate haunting in order to initiate a radical reformulation of the way texts engage readers. In their recent works, Toni Morrison, Don DeLillo, Michael Ondaatje and J.M. Coetzee conjure up specters that primarily affect the form of narrative. For the four contemporary authors who address the diverse readership that their internationally marketed works have gained, a ghost is a valuable figure for eliciting through texts a non-prescriptive and anti-universal communication. Challenging the over-simplified and mass-produced electronic images of cultural ¿others,¿ these specters critique the idea of modern visibility and highlight the constitutive absence against which the world is configured in the 21st century. In other words, when read together, Love, The Body Artist, Anil¿s Ghost, and Slow Man present extensive and diverse critiques against the way contemporary media simplify and dismiss local histories and cultural others to project and facilitate a linear and comprehensive image of the world.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 192 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The Gourmet Gardens Project aims to expose the potential of urban agriculture and the growing movement of local food production that has the power to substantially benefit our cities and ourselves. It offers a product-service-system enabling people to become active participants in local food systems, with the purpose of producing goods within their own home for personal use or for small businesses that can potentially scale-up. To facilitate this process, a modular grower system with seedlings-supply service has been designed for helping people to construct and maintain household gardens. The project is a proof of concept, on designing urban systems for ecologically supportable, contemporary lifestyle with emphasis on the implementation of eco-conscious objects, a model where household furniture adopts to the functionality of food production. Altogether the goal was to design solutions for promotion, awareness and effective application in order to realise food production in a daily life environment. To improve society¿s relationship to nature, to draw on to people¿s enthusiasms so that motivation can be followed through into action.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 144 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Agriculture in India is predominantly rain fed. Agricultural production fluctuates with the vagaries of rainfall in addition to the socio-economic factors. Low yield per unit area across major crops has become a regular feature of Indian agriculture in recent years. Some of the reasons for the low agricultural productivity in our country are (i) lack of sufficient irrigation facilities in major parts of the cultivated land; and (ii) lack of timely availability of quality seeds and fertilizers for the major crops in many parts of the country. Productivity of Indian agriculture is low as compared to the productivity at the global level. Estimates of yield of rice as of April 2011 in India were 3.2 tonnes per hectare as against 7.5 tonnes per hectare in the United States, 6.7 tonnes per hectare in China and an average of 4.3 tonnes per hectare for the World. Also many studies revealed that there is wide variation in productivity of major crops across the States/ Regions in India.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 128 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The Old Testament Book of Psalms has been a great source of inspiration in both Christian and non Christian spiritualities. It is copiously cited in various parts of the New Testament. The author presents in this volume a basic introduction to the Psalms. This work, which is meant to be a guide to the understanding of the message of the Psalms, begins with the etymology of the word 'Psalm', and related words, in Greek, Latin and English. It also includes a brief survey of how this Old Testament Book is called in its original Hebrew language. The aim of these preliminary considerations is to prepare prospective readers for a better understanding and appreciation of the Psalms. Other aspects of the study of the Old Testament Psalms that feature in this book include: literary genres, poetic techniques employed in the Psalms, some major theological themes, the use of the Psalms in the New Testament and in Christian Liturgy. This introduction to the Psalms is designed for all Christians, particularly students of theology, catechists and pastors who might need a handy book in their pastoral activities.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 96 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The book examines the problems of mathematical modeling of complex, including information systems. Fundamental problems of information theory, coding theory, complexity theory, algorithms, theory, probability theory, theoretical cryptography are considered. The basic mathematical problems of information security are discussed. Special attention is given to the availability of presentation. Relationships of fundamental mathematical tasks and problems of information security are obtained.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 276 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Program comparison is needed to evaluate the effectiveness that each program has on similar populations. This study comparatively evaluated an evidence based program and a theory based program designed for intervention with high risk children. The evidence based program used in this study was functional family therapy, and the theory based program was intensive in-home. The comparison of programs was based on archival data assessing parental perception of change in symptomology. Forty-seven parents completed pre and post Youth Outcome Questionnaires for the functional family therapy program and 48 parents completed pre and post Youth Outcome Questionnaires for the intensive in-home program. ANOVA and t-test analyses were used that resulted in significant differences for each program¿s individual effectiveness. However, when compared, neither program was shown more effective over the other. This study highlights the necessity for program evaluation, particularly in terms of evaluating multiple treatment approaches for specific populations.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 168 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -When hydrogen leaks through holes in membrane-electrode assemblies (MEAs) in PEM fuel cells, it recombines directly with air. This recombination results in a reduction in oxygen concentration on the cathode side of the MEA. In this book, the signatures of electrochemical impedance spectroscopy (EIS) are measured and analyzed in a single and different multi-cell stack configurations to show the relation between hydrogen leak rate and reduced oxygen concentrations. A model that establishes a relationship between impedance and voltage was considered. Using this model along with the impedance signatures we were able to detect the reduction of oxygen concentrations at the cathode with the help of fuzzy rule-base.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 140 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Onion (Allium cepa L.) is one of the major vegetable crops cultivated worldwide. Since many onion cultivars are suitable for long-term storage, the summer crop is stored over-winter and supplied to the market over a year. For long term storage, conditions are optimized that are antagonistic for pathogens and favorable for the maintenance of bulb dormancy to delay sprouting, rooting and spoilage. It is imperative to understand the changes in chemical composition of onion during storage and whether these changes can be corroborated to more efficient storage under ambient and/or different storage temperatures. In this study, onion bulbs of a popular Korean onion cultivar 'Sunpower' were stored at different ambient conditions under dark and light conditions. Analysis of chemical composition of stored onion bulbs revealed notable fluctuations in the flavonol and sugar contents while, the amino acid content remained relatively unchanged till the onset of inner sprouting.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 140 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The objective of the work presented in the book deals with the corrosion inhibition behavior of some novel surfactants in acidic medium. A number of gemini and conventional surfactants were synthesized and were tested as corrosion inhibitor in acidic media. The synthesized surfactants were characterized by NMR. The surfactants considered for investigations are: (i) Three cationic gemini surfactants of hexadecyl series with methyl spacers, namely butane diyl-1,4-bis(dimethyl hexadecyl ammonium bromide), pentane diyl-1,5-bis(dimethyl hexadecyl ammonium bromide) and hexane diyl-1,6-bis(dimethyl hexadecyl ammonium bromide), (ii) Two cationic gemini surfactants of tetradecyl series with methyl spacers, namely butane diyl-1,4-bis(dimethyl tetradecyl ammonium bromide) and hexane diyl-1,6-bis(dimethyl tetradecyl ammonium bromide), (iii) One schiff base-based cationic gemini surfactants with S spacers, namely bis[p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene]thiourea and (iv) Triton X-100. The techniques used are weight loss, solvent analysis, potentiodynamic polarization measurements, AC impedance,SEM,EDAX,AFM and thermodynamic/kinetic parameters.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 148 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The formal beginning of English literature as a discipline is a contested site, if not shrouded by mystery altogether. Ben Jonson, Dr Johnson, Matthew Arnold¿all these and many more can claim to be the beginner of a tradition which has travelled deep and wide in time and space for more than ten centuries now. But though the beginnings cannot be ascertained with accuracy, it is clear that the discipline has started falling apart. The essays collected in this book is a modest attempt at understanding the dynamics of this tradition from the literary to the cultural, from ¿English¿ to ¿englishes,¿ from literary criticism to critical theory, from literary studies to cultural studiesVDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 148 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Our Journey Through Aftercare; Voices of Experience explores the journey of twenty young people who had travelled into, through and from the residential care system. In doing so, the differences and similarities of the young people¿s pre- care and through-care experiences were explored as well as the difficulties and challenges they faced in their transition to adulthood and independence. The book identifies three distinct transitions from residential care, those that had travelled a smooth transition, those that had experienced an unstable transition but whose circumstances improved over time and those whose transition was volatile or considerably more problematic and who are still mired in precarious social circumstances. The transitions highlight the diversity of the young people¿s experiences in such a way that emphasizes more clearly the supports that enable some young people to transition successfully and the barriers that lead others towards social exclusion. What is important about this book is the detailed and reflective accounts provided by young people, which gives human resonance to the care leavers¿ experiencesVDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 228 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The study was taken up in Upper Brahmaputra Valley Zone of Assam with the objective of analyzing the effect of risk arising from chronically flood hazards in the State. The perceived risk inherent with the occurrence of flood is the main hindrance in using the inputs and low productivity in the study region. Rice is the dominant crop in the region with little scope for other crops due to hydrological condition. The area is dominant with marginal and small farms with low literacy percentage. The farmers are primarily dependent on the farming and off farm income is very less. Labor showed significant effect under high intensity flood situation, depicting labor as one of the most important factors in risky situations and its effect on the variance showed that labor is also a risk reducing factor under uncertainty condition in high intensity flood condition. A number of risk management strategies viz. ex-ante, ex-post have been suggested which may be useful to small and marginal farmers. It is expected that the book will be useful to planners, extension personnel, field functionaries, research scholars and academician.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 164 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Various problems of pure and applied sciences such as physics, chemistry, biology, engineering, economics, management sciences, industrial research and optimization can be studied in the unified frame work of the system of nonlinear equations. In this study, we develop several new iterative methods for solving a system of nonlinear equations by using different techniques, including quadrature technique, new decomposition method and variational iteration technique. We prove the convergence of the new methods. We obtain the upper bounds of the error of new methods. We also discuss the efficiency index of the proposed methods and compare it with some other well-known methods. We provide several examples for the implementation and performance of the new methods. Comparison with some other existing methods is also given. We also discuss some open research problems.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 176 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Robots providing services to human users in personal context are known as personal service robots. Enriching and facilitating people's lives are their general missions. Acquisition of spatial representations is therefore crucial for such a robot to move around in a human-shared environment, provide services and interact with the user about the environment. With methods developed in the field of autonomous exploration it is possible for a mobile robot to build a metric representation from sensor data, while exploring an initially unknown environment. However, due to the limited perceptual abilities of the robot and dynamic changes in the environment over time, challenges still pose for robots. Besides, in order to make the communication about the environment reliable, a mapping between the spatial understanding of the user and the robot has to be built in a service context. Human Robot Joint Spatial Exploration is proposed in this book to build a framework that allows people to help the robot complete the exploration of the environment initially unknown to it and makes the robot interactively learn from people to build a spatial representation.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 168 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The research of this study was focused on a novel monolithic particle detector, the amorphous-silicon-based microchannel plate (AMCP). This is a vacuum detector, which enables the detection of different types of particle by means of an electron multiplication mechanism. The novelty consists in the fabrication of the microchannel plate (MCP) with a completely new process, where amorphous silicon (a-Si) replaces the lead glass of conventional MCPs.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 204 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -There are lots of different software metrics discovered and used for defect prediction in the literature. Instead of dealing with so many metrics, it would be practical and easy if we could determine the set of metrics that are most important and focus on them more to predict defectiveness. In this book, we use Bayesian modeling to determine the influential relationships among software metrics and defect proneness. Furthermore, we propose a novel technique for defect prediction that uses plagiarism detection tools. We use kernel programming to model the relationship between source code similarity and defectiveness and suggest that source code similarity is a good means of predicting both defectiveness and the number of defects in software systems.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 168 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Nano-optical devices are gaining rapid finding applications in many areas, from sensors to biomolecular devices based on thin films. The precise atomic scale film thickness control and uniformity is a backbone for maintaining propagating optical modes through the waveguide nanostructures fabricated by lithography. Lithography is the key technology that has driven the dynamic growth in the microelectronics and nanophotonics industries over the past three decades. Lithography together with Atomic Layer Deposition (ALD) is a powerful tool for the size reduction of accurately fabricated nanostructures and devices. Replicated Nanophotonic structures in different optical polymer materials are achieved by Nanoimprinting Lithography technology which are employed to augment cost-effective methods and aid for rapidly growing Nanoencapsulation technologies. The design and fabrication of such Resonant Waveguide Gratings (RWGs) for different applications are presented herein. The book also describes the thermo-optic coefficients of various organic and inorganic materials for athermal operation of RWGs over a wide range of temperatures and Polarization-independent subwavelength RWGs.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 204 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -In the present scenario, cut throat competition, stretched goals, cultural differences among the diverse workforce and imbalanced work life have lead to increasing level of stress in employees, also increase the job dissatisfaction. This satisfaction adversely affects the performance of the employees and becomes an undesirable and paramount the organization problem. Hence the scientific researchers shown that the emotional intelligent person is more adaptive to the environment and more productive for the organization. Research also reveal that emotional quotient contributes 80% in the success of the person as compared to the 20% contribution of the intelligence quotient (IQ) only. Therefore, Emotional Quotient is undoubtedly a very important dimension of a person¿s personality. Researchers also suggest that Emotional Intelligence oriented interventions can be successful tools for making employees more job satisfied and stress less. The main of doing the project is to know how well the Emotional Intelligence and Job satisfaction are working together in an organization among the employees in L.I.C.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 180 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -The purpose of the study was to gather information about the social interaction of children with Deafblindness.A qualitative approach and case study, with interviews, combined with observation plus document analysis were used. Results indicated that the interaction of children with Deafblindness varied both in quality and quantity, among themselves and those around them. There is need for intervention strategies by caregivers at all levels of social development and communication. A qualitative 'here' and 'now' interaction and further research are needed to investigate both aspects of physical and social environment, and the interactive process between the individual with Deafblindness and the environmentVDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 172 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -This book analyzes the geopolitical, social, and religious data from the Late Bronze Age archive of Ekalte (today Tall Munb¿qa, Syria), a town situated in the Middle Euphrates area, on the east bank of the river. Ekalte was located between the cities of Karkemi¿ (to the north) and Emar (to the south), and was supposedly included in the land of Ashtata, of which Emar was the capital. The archive of Ekalte consists of 98 Syrian-type, clay tablets which mainly deal with economic and legal contracts: real estate sales, wills, family decrees, etc. The author compares them to the archive of Emar, with the purpose of finding common features in the local administrative hierarchy, the language, and the onomasticon. In view of the results, the author proposes a new chronological frame for the Ekalte tablets and situates them within a temporal span running from 1360 to 1280 BC. According to Torrecilla, the Ekalte archive is contemporary with the Syrian-type tablets from Emar.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 516 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Civilized countries stand in the background: their leaders decided to stake the future on science and technology, in which their countries have generally excelled. Knowledge would thus secure the future of developed world through the creation of a knowledge-based society rooted in higher education, innovation and research (Knowledge Triangle). The 2020s inevitably will see an intensified interest in these areas on the part of national and regional governments, higher education institutions and economic life across the world, in response to the pressing global challenges. This book is the creation of a monograph integrating state-of-the-art and trend of Knowledge Triangle the world over. It also serves as a detailed scholarly study, a contributor for the provision of the skills necessary for political, economic and social progress, then a reference book, where often a major aim is to professionalise the teacher training units. As a new teaching material meets lifelong learning aspect, placing the emphasis on self-study and serving as a knowledge source by reader-friendly information, helps familiarise decision-makers, administrators of the Knowledge Triangle and the laymen alike.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 576 pp. Englisch.

Taschenbuch. Condizione: Neu. Neuware -Within the Central Congo Basin, semi-deciduous forests are established on contrasted habitats marked by sandy and clay substrates. We present a case study of plant communities located in a particular zone of our study area where sandy and clay substrates encounter over a steep textural gradient. We then analyze species distribution patterns driven by this edaphic differentiation, with a particular interest on vegetation features in the interface zone. We also describe the spatial structure of the considered edaphic variables, based on the Moran¿s index. The relationships between soil features and species within forest layers are also exposed. We show that some species are much more related to a type of soil, therefore defining some ¿edaphic specialists¿ species while many others can be considered ¿generalists¿. As of current scientific interest, we focus on phylogenetic patterns occurring in these plant communities and examine the way all this is linked to the observed edaphic heterogeneity.VDM Verlag, Dudweiler Landstraße 99, 66123 Saarbrücken 228 pp. Englisch.