نتایج جستجو برای: ducks being swimming and flying
تعداد نتایج: 16847617 فیلتر نتایج به سال:
the debate whether esp teachers need to have knowledge of the specialized field they are teaching has been an issue in the literature over the last two decades. the aim of conducting this study was to explore iranian learners’ and instructors’ beliefs and attitudes concerning the role of specialized knowledge in teaching esp classes. a seventeen item questionnaire was administered to 400 esp le...
the subjects of the study are only the tefl teachers and students at gilan university. to obtain the desired data, a questionnaire which was based on the theories and disecussions gathered, was used as the main data gathering instrument. to determine the degree of relationship between variables, covariance and pearson product moment correlation coefficient were the formulas applied. the data we...
This symposium approaches answers to these questions from multiple directions. Four primary sets of technological developments have come together in the past decade to make it possible to revisit each of these questions in innovative, quantitative ways. These developments are: a) highspeed digital video photography; b) algorithms for rapid analysis of digital images; c) laser based quantitative...
Simple models are presented of the energetics of annual migration and of central place foraging, taking account of the speed and energy cost of the journeys. They are applied to insects, fish, birds and mammals of a wide range of sizes, which travel by flapping or soaring flight, by swimming or by running. It is shown that annual migrations of several thousand kilometres are unlikely to be bene...
Rosin was once widely used for removal of duck feathers in China and is still being used secretly in some poultry processing enterprises. Abietic acid (AA) and dehydroabietic acid (DHAA) are the major compounds of rosin. In the present study, 90 duck samples were collected for investigation of AA and DHAA residues. Abietic acid and DHAA were simultaneously detected in 13 out 40 raw ducks, 8 out...
Migration is ubiquitous among animals and has evolved repeatedly independently. Comparative studies of the evolutionary origins migration in birds are widespread, but lacking mammals. Mammalian species have greater variation functional traits that may be relevant for migration. Interspecific behaviour often attributed to mode locomotion (i.e. running, swimming, flying) body size, associated wit...
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