rain is one of the manifestations of the divine blessing for servants which plays a very important role in the life of this human being. man has paid special attention to rain since he stepped on earth. many poets have described rain, used it in their similes and composed poetry out of it. they have used rain as a symbol together with other symbols such as woman, praise, battleground and so man...

Seasonal changes in the neural attributes of brain nuclei that control song in songbirds are among the most pronounced examples of naturally occurring plasticity in the adult brain of any vertebrate. The behavioral correlates of this seasonal neural plasticity have not been well characterized, particularly in songbird species that lack adult song learning. To address this question, we investiga...

One hypothesis for the function of vocal repertoires in songbirds is that singing multiple song types facilitates song matching, a behaviour in which one male replies to a rival’s song with a song of the same type. In eastern populations of song sparrows, low levels of whole song sharing restrict opportunities for matching of entire song types. A male in this population might still match a neig...

Juvenile white-crowned sparrows learn to sing by first memorizing an adult's song and then progressively matching their vocalizations to this model during plastic song. Previous studies have shown that neurons in the song-system nucleus HVC of adult sparrows respond preferentially to a bird's own song. In this study, the auditory selectivity of HVC neurons in subadult birds was examined. In you...

Auditory neurons of the anterior forebrain (AF) of zebra finches become selective for song during song learning. In adults, these neurons respond more to the bird's own song (BOS) than to the songs of other zebra finches (conspecifics) or BOS played in reverse. In contrast, AF neurons from young birds (30 d) respond equally well to all song stimuli. AF selectivity develops rapidly during song l...

Males of the species Drosophila melanogaster – the common fruit fly – court their females. During courtship the male extends and vibrates his wing and thereby produces courtship song, which consists of two qualitatively different modes: sine and pulse song. During song, males repeatedly switch between sine and pulse. Recent studies suggest that the male switches not randomly, but chooses whethe...

Droughts are one of the most damaging climatic phenomena, and the most complex natural hazard  which affects the economy, agriculture, public health and environment in large areas. The aim of this study is to compare drought indicators derived from tropical rainfall measuring mission (TRMM) data in the south of Iran. Also the TRMM rainfall was considered, so as to investigate changes in the rai...