1,721,180 research outputs found
Origins of Food Preference in Herbivores
Get PDFFood preference is best understood as the interaction between taste and postingestive feedback, determined by an animal\u27s physiological condition and to a food\u27s chemical characteristics. Taste (as well as smell and sight) enables animals to discriminate among foods and provides hedonic sensations associated with eating. Postingestive feedback calibrates taste in accord with a food\u27s homeostatic utility: preference increases when foods are adequate in nutrients; conversely, preference decreases when foods are deficient in nutrients, when they contain excesses of toxins, and when they are too high in rapidly digestible nutrients. Preference also decreases when familiar foods are eaten too frequently or in excess, which causes animals to eat varied diets. Experiences early in life affect preference. Young animals acquire dietary habits as a result of eating particular foods, and they are reluctant to eat novel foods or familiar foods whose flavors have changed. These findings suggest: (1) deterrents based merely on offensive flavors are not likely to be effective in the absence of aversive postingestive effects, (2) many repellents are ineffective because they merely change the flavors of familiar foods (i.e., novelty effects), and (3) management to deter herbivores from eating foods must provide nutritious alternatives
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
CHEMICAL DEFENSE AND MAMMALIAN HERBIVORES
Get PDF1. Plant Metabolism 2. Phytochemical Variation in Plants 3. Plant Defense Theory 4. Mammalian Metabolism of Phytochemicals 5. Mammalian Herbivory Related Chapter
Social Organization, Culture and Use of Landscapes by Livestock
No full textThe social facets of foraging typically are not considered in studies of food and habitat selection even though they are an indispensable part of the lives of most herbivorous mammals and of effectively managing landscapes. Through interactions with mother and peers, young animals learn what and what not to eat and where and where not to go in an environment, which collectively leads to the home-field advantage . The behavior of any individual is influenced as genes are expressed through interactions with social and biophysical environments, and experiences early in life markedly influence those relationships. Social organization leads to culture, wherein young animals learn from their ancestors through their mothers, and in the process the accumulated knowledge of how to use landscapes is passed from generation to generation. Cultures develop when learned practices contribute to the groupís success in solving problems, and they evolve as individuals in groups discover new ways of behaving, as with finding new foods or habitats and better ways to use foods and habitats. Unfortunately, we have lost much of the knowledge of behavior used by our ancestors whose survival depended on hunting the wild herds and on domesticating ancestors of todayís cattle, sheep, and goats. Our lack of appreciation of the social facets of foraging is apparent in the problems we encounter as we attempt to manage herbivores. Conversely, we can use knowledge of sociality to enhance management of landscapes to benefit soils, plants, herbivores, and people
Tracking Variable Environments: There is More than One Kind of Memory
No full textThree kinds of memory help herbivores track changes in the environment. The first is the collective memory of the species with genetic instructions that have been shaped by the environment through millennia. This includes skin and gut defense systems. Auditory and visual stimuli and sensations of pain impinge upon the skin defense system that evolved in response to predation. The taste of food and the sensations of nausea and satiety are an integral part of the gut defense system that evolved in response to toxins and nutrients in plants. The second kind of memory in social mammals is represented by the mother, a source of transgenerational knowledge, who increases efficiency and reduces risk of learning about foods and environments. The third kind of memory is acquired by individual experience. Post-ingestive feedback from nutrients and toxins enables individuals to experience the consequences of food ingestion and to adjust food preference and selection commensurate with a food\u27s utility. The three memories interact, each linking the past to the present, and collectively shape the present and future of every individual. Thus, the dynamics of foraging involves appreciating the uniqueness of individuals and subgroups of animals, each with their own genetic and behavioral history, and recognizing that foraging behaviors may not be stable, optimal, or even predictable in the conventional sense
What Does It Mean to Be Locally Adapted and Who Cares Anyway?
No full textThe availability of fossil fuels will likely decline dramatically during the first half of the twenty-first century, and the massive deficits probably will not be alleviated by alternative sources of energy. This seeming catastrophe will create opportunities for communities to benefit from foods produced locally in ways that nurture relationships among soil, water, plants, herbivores and people to sustain their collective well beings. Agriculture will be much more at the heart of communities than it is currently, but by necessity, it will no longer be so dependent on fossil fuels to power machinery or to produce fertilizers, herbicides and insecticides to grow and protect plants in monocultures, antibiotics and anthelmintics to maintain the health of herbivores, or nutritional supplements and pharmaceuticals to sustain humans. Rather, from soils and plants to herbivores and people, we will have to learn once again what it means to be locally adapted to the landscapes we inhabit. In the process of re-learning these skills, plants will become more important as nutrition centers and pharmacies, their vast arrays of primary (nutrients) and secondary (pharmaceuticals) compounds useful in nutrition and health. There also will be a need, as in times past before our heavy reliance on fossil fuels, to produce livestock in easy-care systems that match seasonally-available forages with production needs, and that match animals anatomically, physiologically and behaviorally to local landscapes. This will mean reducing inputs of fossil fuels to increase profitability by: 1) matching animal needs to forage resources; 2) selecting for animals that are adapted anatomically, physiologically, and behaviorally to local environments; 3) culling animals unable to reproduce with minimal help from humans, and 4) creating grazing systems that enhance the well-being of soils, plants, herbivores, and people
Twenty-Five Years of Paradox in Plant-Herbivore Interactions and Sustainable Grazing Management
No full textThe Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202
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