interpolation, the generalization of point data to scatter data, and combining maps are three cases of important applications of gis. in this study, it has been tried to make the estimation of rain erosion capacity (fournier method) more real through using gis capability in interpolation and the generalization of point data to scatter data. in fournier method, the rain erosion capacity is calcu...

The singing of song birds can form complex signal systems comprised of numerous subunits sung with distinct combinatorial properties that have been described as syntax-like. This complexity has inspired inquiries into similarities of bird song to human language; but the quantitative analysis and description of song sequences is a challenging task. In this study, we analysed song sequences of co...

Auditory neurons in the forebrain nucleus HVc (hyperstriatum ventrale pars caudale) are highly sensitive to the temporal structure of the bird's own song. These "song-specific" neurons respond strongly to forward song, weakly to the song with the order of the syllables reversed, and little or not at all to reversed song. To investigate the cellular mechanisms underlying these responses, in vivo...

Male birds of age-limited song-learning species develop their full song repertoires in the first year of life. For this type of song learner, once song is stabilized in adulthood, it is highly stereotyped and stable over time. Traditionally, it has been believed that age-limited song learners do not depend on auditory feedback for the maintenance of adult song. A recent report, however, showed ...

Plasticity is often thought to accelerate trait evolution and speciation. For example, plasticity in birdsong may partially explain why clades of song learners are more diverse than related clades with innate song. This "song learning" hypothesis predicts that (1) differences in song traits evolve faster in song learners, and (2) behavioral discrimination against allopatric song (a proxy for pr...

The zebra finch acquires its song by first memorizing a model song from a tutor and then matching its own vocalizations to the memory trace of the tutor song, called a template. Neural mechanisms underlying this process require a link between the neural memory trace and the premotor song circuitry, which drives singing. We now report that a premotor song nucleus responds more to the tutor song ...

Like many other songbird species, male zebra finches learn their song from a tutor early in life. Song learning in birds has strong parallels with speech acquisition in human infants at both the behavioral and neural levels. Forebrain nuclei in the 'song system' are important for the sensorimotor acquisition and production of song, while caudomedial pallial brain regions outside the song system...

Songbirds develop their songs by imitating songs of adults. For song learning to proceed normally, the bird's hearing must remain intact throughout the song development process. In many species, song learning takes place during one period early in life, and no more new song elements are learned thereafter. In these so-called close-ended learners, it has long been assumed that once song developm...

Rain attenuation is a major shortcoming of microwave transmission. J.S Ojo1, 2, M.O Ajewole1, S.K Sarkar2. An improved approach of predicting rain attenuation cumulative. rain attenuation formula Approach for determining the values of rain attenuation at different.Attenuation due to rain is an important constraint in the designing of the microwave. The paper presents a new prediction model of r...