Download or read book Advances in Plant Physiology Vol 13 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2012-08-01 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: The plant physiology and plant molecular biology research group has evidently endorsed the new directions taken by the treatise to attract the pre-eminent scientists in plant biology/plant sciences. Certainly, the preparation of Volume 13 of the International Treatise Series on Advances in Plant Physiology has been done entirely due to commendable contributions from Scientists of Eminence in unequivocal fields. Unquestionably, our objective is to publish innovative science of value across the broad disciplinary range of the treatise. I restate that this plan has been undertaken with a view to strengthen the indistinguishable efforts to recognize the outcome of meticulous research in some of the very sensible and stirring areas of Plant Physiology-Plant Molecular Physiology/ Biology-Plant Biochemistry for holistic development of the science of agriculture and crop production under changing climate. I am ardent to keep on the exceptionality and the prologue of excellent new ideas ensuring that the treatise calls to the best science done across the full extent of modern plant biology, in general, and plant physiology, in particular. In Volume 13, with inventive applied research, attempts have been made to bring together much needed eighteen review articles by forty-eight contributors especially from premier institutions of India for this volume. All the eighteen review articles have been grouped in five broad sections, which on the whole highlight the necessity to find out evidence from the fields of plant nutriophysiology (physiology of plant mineral nutrients) and abiotic stresses under changing climate along with their control.

Download or read book Advances in Plant Physiology written by P. C. Trivedi and published by I. K. International Pvt Ltd. This book was released on 2013-12-30 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present scenario, with the increasing pressure posed by a rapidly growing population and diminishing per capita arable land and sources of irrigation, the role of plant physiologists in increasing agricultural and horticultural production by economically viable means, is significant. The present book incorporates articles covering latest information on the varied aspects of plant physiology, like diagnosis and management of physiological disorders in fruit production, physiology of vegetable crops, breeding crops for dryland conditions, effect of sulphur dioxide on growth, photosynthesis, antioxidant enzyme activities and so on. Topics such as abiotic stress, macronutrient stress and stress caused by pollutants also form part of the book. Articles on the effect of herbicides, growth hormones, photoquality on germination and physiology of rice and groundnut provide useful information for improving crop yield. This book would serve as a useful reference for teachers, scientists and planners in the fields of Botany, Plant Physiology, Agriculture, Forestry and related fields

Download or read book Advances in Plant Physiology Vol 10 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2008-07-01 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. S.K. Panda & Dr. (Mrs.) M. Dash This book ``Advances in Stress Physiology of Plants' has been published with an aim to give some insight into the field of stress physiology of Plants. Attempts have been made to highlight different abiotic stresses like water, salt, heavy metals etc. and there effects on plants physiological alterations. Some efforts have also been taken to discuss oxidative stress, its effects and possible protection in plant cells. Oxidative Stress The Biology of Oxidative stress in Green Cells : A Review S.K. Panda & M. Dash Abiotic Stress Induced Membrane Damage in Plants : A Free Radical Phenomenon S. Bhattacharjee & A.K. Mukherjee The Lipoxygenases A Review A.D. Rao, K.N. Devi & K. Thyagaraju Plant Lipoxygenases K.N. Devi, A.D. Rao & K. Thyagaraju Changes in Antioxidants Levels in Oryza sativa L. Roots subjected to NaCl-salinity stress M.H. Khan, M. Dash, Ksh. L.B. Singha & S.K. Panda Water Stress Studying Plant Responses to Water Stress : An Overview R.K. Kar Salt Stress Effects of Sea Water on Growth of Young Plants of Prosopis julliflora (sw) DC. A.J. Joshi & H. Hinglajia Physiology of Salt Stress in Plants : A Review M. Dash & S.K. Panda Heavy Metal Toxicity Stress Role of Nitrogen Nutrition on Chromium Phytoxicty in wheat S.K. Panda, B.N. Sahoo & H.K. Patra Chromium Toxicity and Water Stress Simulation Effects in Intact Senescing Leaves of Greengram (Vigna radiata L. var. wilckzek K851) S.K. Panda, S. Mahapatra & S.K. Panda Alterations in Enzyme Activities of Plants under Heavy Metal Ion Stress S.D.S. Murthy & S. Rajgopal Dr. S.K. Panda & Dr. (Mrs.) M. Dash This book ``Advances in Stress Physiology of Plants' has been published with an aim to give some insight into the field of stress physiology of Plants. Attempts have been made to highlight different abiotic stresses like water, salt, heavy metals etc. and there effects on plants physiological alterations. Some efforts have also been taken to discuss oxidative stress, its effects and possible protection in plant cells. Oxidative Stress The Biology of Oxidative stress in Green Cells : A Review S.K. Panda & M. Dash Abiotic Stress Induced Membrane Damage in Plants : A Free Radical Phenomenon S. Bhattacharjee & A.K. Mukherjee The Lipoxygenases A Review A.D. Rao, K.N. Devi & K. Thyagaraju Plant Lipoxygenases K.N. Devi, A.D. Rao & K. Thyagaraju Changes in Antioxidants Levels in Oryza sativa L. Roots subjected to NaCl-salinity stress M.H. Khan, M. Dash, Ksh. L.B. Singha & S.K. Panda Water Stress Studying Plant Responses to Water Stress : An Overview R.K. Kar Salt Stress Effects of Sea Water on Growth of Young Plants of Prosopis julliflora (sw) DC. A.J. Joshi & H. Hinglajia Physiology of Salt Stress in Plants : A Review M. Dash & S.K. Panda Heavy Metal Toxicity Stress Role of Nitrogen Nutrition on Chromium Phytoxicty in wheat S.K. Panda, B.N. Sahoo & H.K. Patra Chromium Toxicity and Water Stress Simulation Effects in Intact Senescing Leaves of Greengram (Vigna radiata L. var. wilckzek K851) S.K. Panda, S. Mahapatra & S.K. Panda Alterations in Enzyme Activities of Plants under Heavy Metal Ion Stress S.D.S. Murthy & S. Rajgopal

Download or read book Advances in Plant Physiology Vol 14 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2013-11-01 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: In view of changes in the global environment, it is important to determine and developing technologies to ameliorate metabolic limitations by biological processes most sensitive to abiotic stress factors warning crop productivity. It is reaffirmed that publishing the important Treatise Series has been undertaken with a view to identify the inadequacies under varied environments and to scientifically extend precise and meaningful research so that the significant outcomes including new technologies are judiciously applied for requisite productivity, profitability and sustainability of agriculture. Besides this, meticulous research in some of the very sensible and stirring areas of Plant Physiology-Plant Molecular Physiology are indispensably needed for holistic development of agriculture and crop production in different agro-climatic zones. Ardently, this is also to focus upon excellent new ideas ensuring the best science done across the full extent of modern plant biology, in general, and plant physiology, in particular. In Volume 14, with inventive applied research, attempts have been made to bring together much needed eighteen remarkable review articles distributed in three appropriate major sections of Nutriophysiology and Crop Productivity, Plant Responses to Changing Environment and Environmental Stresses and Technological Innovations in Agriculture written by thirty four praiseworthy contributors of eminence in unequivocal fields mainly from premier institutions of India and abroad. In reality, the Volume 14 of the Treatise Series is wealth for interdisciplinary exchange of information particularly in the field of nutriophysiology and abiotic stresses for planning meaningful research and related education programmes in these thrust areas. Apart from fulfilling the heightened need of this kind of select edition in different volumes for research teams and scientists engaged in various facets of research in Plant Physiology/Plant Sciences in traditional and agricultural universities, institutes and research laboratories throughout the world, it would be tremendously a productive reference book for acquiring advanced knowledge by post-graduate and Ph.D. scholars in response to the innovative courses in Plant Physiology, Plant Biochemistry, Plant Molecular Biology, Plant Biotechnology, Environ-mental Sciences, Plant Pathology, Microbiology, Soil Science & Agricultural Chemistry, Agronomy, Horticulture, and Botany.

Download or read book Advances in Plant Physiology Vol 9 written by A. Hmantaranjan and published by Scientific Publishers. This book was released on 2007-01-01 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: The configuration of Volume 9 of the International Treatise Series has been done absolutely due to commendable contributions from World Scientists of eminence in unambiguous fields. Amazingly, within the time span of nine years, now this treatise has been duly recognized through 151 Web of Knowledge Current Contorts in - the hearts of distinguished readers and has beyond doubt achieved the international status. This programme has been undertaken with a view to reinforce the identical efforts to recognize the outcome of meticulous research in some of the very sensible and stirring areas of Molecular Physiology & Biology of Plants. In order to sustain and further advance Plant Physiology, it is dedicated to continue the originality and the introduction of spanking new ideas, ensure that the treatise welcomes the best science done across the full extent of modern plant biology, in general, and plant physiology., in particular, persevere on advancing the quality of what is published, place high value on the quality of production, and be highly attentive and responsive to the rapidly changing face of academic publishing. In spite of handiness of quick accessibility of vast literature from internet, this treatise series in the field of life sciences has been realized over and above to be like a true guide, friend and philosopher, everlastingly enlightening the most hidden perceptible nerves of an individual worker, which is beyond the competence of mere web service. In Volume 9. with inventive applied research, attempts have been made to bring together much needed twenty review articles by Forty-six contributors from Australia, Belgium, France, Germany, India, Italy and Spain dispersed duly evaluated by the respective Consulting Editors of international stature from India, U.K.:4„ U.S.A., Argentina. Australia, France, Germany, Japan, Spain. Portugal, Israel, and Morocco and rationally disseminated in Nine Sections. Creditably in this volume, over ten important reviews belong to the field of Environmental Stresses besides covering significant areas of research. In reality the treatise is prosperity fir interdisciplinary exchange of information. Apart from fulfilling the firm need of this kind of exclusive edition in different volumes for research teams and scientists engaged in various facets of research in Molecular Physiology and Biology of Plants in traditional and agricultural universities, institutes and research laboratories throughout the world, it would be extremely a constructive book and a voluminous reference material for acquiring advanced knowledge by post-graduate and Ph.D. scholars in response to the innovative courses in Plant Physiology, Plant Biochemistry, Plant Molecular Biology, Plant Biotechnology, Environmental Sciences, Plant Pathology, Microbiology, Soil Science & Agricultural chemistry, Agronomy, Horticulture, and Botany.

Download or read book Advances in Plant Physiology Vol 18 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2019-08-06 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reinforcement of Volume 18 of the Advances in Plant Physiology Series has been entirely due to commendable contributions by Scientists of Eminence in explicit fields. The enterprise of publishing the International Treatise Series on Plant Physiology has to genuinely sort out the scantiness of consequential researches, which are sincerely required for rising productivity, prosperity and sustainability of agriculture through prominently emerging technologies for reformation in metabolic boundaries necessitates mainly for abiotic stress factors. Unquestionably, our thought is to be familiar with ground-breaking science of value across the broad punitive range of the treatise. The aspiration is to make stronger the vital outcome of conscientious research in some of the very responsive areas of Plant Physiology-Plant Molecular Physiology/Biology that broadly focus upon the advancements coupled with underlying mechanisms of plant tolerance under changing environments. The Volume 18, with innovative applied research, brings jointly much needed nineteen review articles by over fifty committed contributors for this volume. The Volume 18 exclusively deals with challenges of continuing worldwide concern over the stress physiology research. Conversely, this volume also highlights trace elements; plant functional research; physiological basis of yield variation; medicinal and aromatic plants.

Download or read book Experimental Ecophysiology and Biochemistry of Trees and Shrubs written by Humberto González Rodríguez and published by CRC Press. This book was released on 2020-11-01 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existence and competition of trees and shrubs to sustain and put forth growth under varied environmental conditions is dependent on the interactions that occur between the plant metabolic processes and the prevailing environmental conditions. In order to understand the productivity of trees and shrubs, it is a prerequisite to know the experimental techniques of these vital processes. This volume provides a comprehensive presentation of this topic. The first part of this book deals with various aspects of experimental ecophysiology and recent research results of studies on plant pigments, epicuticular wax, leaf nutrients, carbon fixation, all supported by literature. The second part of the volume describes various laboratory techniques such as diffusion, imbibition, calorimetry, atomic absorption, mineral nutrition, nutrition analysis of forage, litterfall chemistry, nutrient cycle, etc. The third and fourth parts deal with advances in the techniques in the development of ecophysiology. The book will serve as an important handbook and resource for students, faculty and teachers, technicians, and researchers and scientists involved in forest science dealing with ecophysiology and biochemistry of woody and crop plants.

Download or read book Physiology of Plants Under Abiotic Stress and Climate Change written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2011-02-09 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a wealth of spanking insight for directing interdisciplinary exchange of information especially in the fields of abiotic stresses and climate change for planning meaningful research as well as advancing education programmes in such indispensable areas. Apart from satisfying the acute need of this kind of exclusive edition for research teams and scientists engaged in various facets of research in plant physiology in traditional and agricultural universities, institutes and research laboratories throughout the world, it would be extremely a constructive book and a voluminus reference material for imbibing thought provoking knowledge by post-graduate and Ph.D. scholars in response to the innovative course in plant Physiology, Plant Biochemistry, PlantMolecular Biology, Plant Biotechnology, Environmental Science, Plant Pathology, Microbiology, soil Science Agricultural Chemistry, Agronomy, Horticulture, and Botany.

Download or read book Coconut Genetic Resources written by Pons Batugal and published by Bioversity International. This book was released on 2005 with total page 797 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant Breeding Reviews written by Jules Janick and published by John Wiley & Sons. This book was released on 2008-01-14 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant Breeding Reviews presents state-of-the-art reviews on plant breeding and genetics covering horticultural, agronomic and forestry crops, incorporating both traditional and molecular methods. The contributions are authored by world authorities, anonymously reviewed, and edited by Professor Jules Janick of Perdue University, USA. The series is an indispensible resource for crop breeders, plant scientists, and teachers involved in crop improvement and genetic resources. Initiated in 1983, Plant Breeding Reviews is published in the form of one or two volumes per year. Recently published articles include: Epigenetics and Plant Breeding (v30) Enhancing Crop Gene Pools with Beneficial Traits Using Wild Relatives (v30) Coffee Germplasm Resources, Genomics and Breeding (v30) Molecular Genetics and Breeding for Fatty Acid Manipulation in Soybean (v30) Breeding Southern Highbush Blueberries (v30) Development of Fire Blight Resistance by Recombinant DNA Technology (v29)

Download or read book Index of Conference Proceedings written by British Library. Document Supply Centre and published by . This book was released on 1999 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Coconut Palm Cocos nucifera L Research and Development Perspectives written by V. Krishnakumar and published by Springer. This book was released on 2019-02-15 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of "The coconut palm - A monograph" in 1960, considerable information has been accrued on the crop through work at research institutes, international organisations and development agencies. Although coconut cultivation is spread over 93 countries, providing employment and creating livelihood opportunities to 64 million families around the globe, smallholder coconut farmers are now facing numerous challenges. The wide gap between the potential and actual yield is a major concern, and as such it is necessary to disseminate knowledge in order to implement research findings. Coconut research in India, one of the leading coconut producing countries, is celebrating its centenary, making this an opportune time to review the research and development advances and the relevant technologies. This detailed, comprehensive book covers all aspects of coconut, from the origins to cultivation, breeding, physiology and value addition, as well as subjects of topical interest like nutrition and health, biotechnology, and climate change and carbon sequestration. Written by leading experts in the fields it emphasises that the livelihood of the small coconut landholders is the ultimate aim of scientists and developmental agencies, and outlines various important strategies to make coconut farming more remunerative globally. It discusses work in all the major coconut growing countries and outlines suggestions for international cooperation. Research work on the crop is comparatively difficult because of its perennial nature, longevity, height, long juvenile phase, large sized nuts, cross pollination and seed propagation. As these special features necessitate greater investment of resources, time and land, it is all the more imperative that research is not duplicated and the information and experience becoming available around the world is shared so that it can be fully utilised. In this context periodic publications, compiling all the available information on coconut assume greater significance. This book is therefore of great value to researchers, students, extension workers, developmental agencies and progressive farmers.

Download or read book Phytotechnology Emerging Trends written by M. Daniel and published by Scientific Publishers. This book was released on 2012-07-01 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the rapidly expanding horizons of Plant Sciences. The conventional aspects of Botany remain the backbone of this subject, but the growing population and environmental compulsions urge man to explore new avenues to tackle the problems of society. Most of these areas, which are interdisciplinary in nature and provide new and better solutions, are pursued vigourously by researchers in Plant Sciences. Medicinal plants including Nutraceuticals, Biofuels, Natural Dyes, Biofertilisers, Biopesticides, Plant propagation methods including Tissue culture, Plant Genomics, Proteomics, Climate change and Remote sensing techniques inclusive of GIS are some of the such emerging areas focused in this book. The present book contains a good number of scien-tific articles penned by expert researchers in all these fields. Since researches in these areas are pursued in many of the Research centres and Universities, this book will be a valuable and essential reference book for one and all who are interested in these subjects.

Download or read book Advances In Plant Physiology Vol 6 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2003-11-01 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: The publication of Volume 6 of the International Treatise Series on Advances in Plant Physiology has been feasible - exclusively and unquestionably due to commendable contributions from World Scientists of distinction in explicit fields. within eight years, the treatise series has been instituted in the spirits and compassion of illustrious readers all through the world. The proficient International and National Co-ordinators have all along unified their views for the expediency of readers assisting them to speed up important research work in the field of Plant and Crop Physiology, Biochemistry & Plant Molecular Biology. in spite of handiness of quick accessibility of vast literature from internet, this treatise series in the field of life sciences has been realized over and above to be like a true guide, friend and philosopher, everlastingly enlightening the most hidden perceptible nerves of an individual worker, which is beyond the competence of mere web services. The volume 8 is absolutely another one of its kinds for incorporation of most timely and important worthy reviews of diverse objectives contributed by forty four well-informed, admirable and documented scientists/ stalwarts, of which twenty three participated from abroad. The original writing coming in bounteous journals of international repute covering new technologies and tools in plant science research have been pulled together in affirmative, prolific and supportive manner by specialists all over the globe. In this volume efforts have been made to fetch together twenty one indispensable review articles, duly evaluated by the respective Consulting Editors of international stature from India, U.K., U.S.A., Argentina, Australia, France, Germany, Japan, Spain, Portugal, Israel, and Morocco and rationally distributed in eight sections. Indeed, the treatise is wealth for interdisciplinary exchange of information. Apart from fulfilling need of this kind of exclusive edition in different volumes for research teams in Molecular Plant Physiology and Biochemistry in traditional and agricultural universities, institutes and research laboratories throughout the world, it would be extremely a constructive book and a voluminous reference material for acquiring advanced knowledge by post-graduate and Ph.D. scholars in response to the innovative courses in Plant Physiology, Plant Biochemistry, Plant Molecular Biology, Plant Biotechnology, Environmental Sciences, Plant Pathology, Microbiology, Soil Science & Agricultural Chemistry, Agronomy, Horticulture, and Botany. Indeed, the treatise is wealth for interdisciplinary exchange of information. Apart from fulfilling need of this kind of exclusive edition in different volumes for research teams in Molecular Plant Physiology and Biochemistry in traditional and agricultural universities, institutes and research laboratories throughout the world, it would be extremely a constructive book and a voluminous reference material for acquiring advanced knowledge by post-graduate and Ph.D. scholars in response to the innovative courses in Plant Physiology, Plant Biochemistry, Plant Molecular Biology, Plant Biotechnology, Environmental Sciences, Plant Pathology, Microbiology, Soil Science & Agricultural Chemistry, Agronomy, Horticulture, and Botany.

Download or read book Advances in Plant Physiology Vol 12 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2011-10-01 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: The innovative theme of the International Treatise Series on “Advances in Plant Physiology”, Volume 12 “Physiological and Molecular Interventions for Crop Improvement under Changing Environments” has been especially edited for rational use by planners, scientists, investigators, academicians and postgraduate students. This book is an exceptional assimilation of timely, vital and inclusive twelve worthy reviews of varied significance, especially in view of the changing macro- and micro-climate influencing physiology of plants at all levels, contributed by true commitment of experienced, laudable and well-known scientists/ stalwarts all over the world. This is also strongly realized that there is with time more a need of united effort for the holistic development in the agricultural sciences, which absolutely depends on environmental situations. The threat of changing climate has imposed challenge to world scientists and their efforts in understanding reasons of yield reductions at physiological and molecular levels have been intensified. The consistent outcome are imparted with genetic engineers who have to now under the present circumstances exclusively identify, isolate and purify specific genes from DNA sequences befitting for development of tolerance mechanism in crop plants under changes of different degrees of intensity in environment. That is naturally the step wise long process having several pros and cons to arrive at any conclusion. Hence, the treatise series is the need of the hour and excellent source to disseminate meaningful distilled thoughts emerging out of extensive research which has due relevance for planning consequential basic strategic research besides direct help to the mankind. The intricacies of abiotic and biotic stresses on growth and development of plants have been understood in the last few decades. This book too is an endeavour to make aware the young workers to gain information on researches of basic and applied significance for extending consequential research of physiological and molecular approaches for crop improvement under changing environment. The manifold ideas on basic problems of the present and the future as well as resolutions, in part, have been consolidated which will be accomplished in subsequent volumes.

Download or read book References no 32555 36587 AAR ZVA written by Zdenek Sesták and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances In Plant Physiology Vol 4 written by A. Hemantaranjan and published by Scientific Publishers. This book was released on 2002-07-01 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researches have made tremendous progress in the area of Plant Physiology, greatly increasing our understanding of living processes, necessary for biotechnological research. Different volumes of the treatise ``Advances in Plant Physiology'' covers the entire spectrum of Plant Physiology including the Plant Molecular Biology in order to encourage meaningful research in the coming twenty-first century. The true endeavor in this direction is the result of comprehensive, authoritative and timely publication of this valuable treatise, provides the reader with the most recent information, views and references focused on individual topics through a rich collection of reviews contributed by pioneer workers and of those actively engaged in the studies of various specific areas in different parts of the world with extensive experience, established record of eminence and noted authorities. In fact, this treatise is a treasure for interdisciplinary exchange of information and the approach to topic ranges from theoretical to applied molecular to organismic and single to multivariable systems. Apart from fulfilling the need of this treatise for research teams and scientists actively working in the areas of plant physiology biochemistry and plant molecular biology in universities institutes and research laboratories throughout the world, it would be extremely a useful book and a voluminous reference material for acquiring advanced knowledge by students in response to innovative courses in Plant Physiology, Plant Biochemistry, Agronomy, Genetics and Plant Breeding, Genetic Engineering, Microbiology, Plant Biotechnology and Botany. Over eighteen (18) chapters of Vol. 1 extensively elucidate the needful topics of Biological Nitrogen Fixation, Plant Cell and Tissue Culture, Plant Metabolism , certain rare Techniques in Plant Physiology, Herbicides Physiology, Plant Growth Regulators, Physiology of Rooting, Tree Physiology, Stress Physiology (in part) and Growth and Development Hopefully, Vol. II will comprise other important topics.