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We studied the role of echolocation and other sensory cues in two small frugivorous New World leaf-nosed bats (Phyllostomidae: Artibeus watsoni and Vampyressa pusilla) feeding on different types of fig fruit. To test which cues the bats need to find these fruit, we conducted behavioral experiments in a flight cage with ripe and similar-sized figs where we selectively excluded vision, olfaction, and echolocation cues from the bats. In another series of experiments, we tested the discrimination abilities of the bats and presented sets of fruits that differed in ripeness (ripe, unripe), size (small, large), and quality (intact(infested with caterpillars). We monitored the bats' foraging and echolocation behavior simultaneously. In flight, both bat species continuously emitted short (<2 ms), multi-harmonic, and steep frequency-modulated (FM) calls of high frequencies, large bandwidth, and very low amplitude. Foraging behavior of bats was composed of two distinct stages: search or orienting flight followed by approach behavior consisting of exploration flights, multiple approaches of a selected fruit, and final acquisition of ripe figs in flight or in a brief landing. Both bat species continuously emitted echolocation calls. Structure and pattern of signals changed predictably when the bats switched from search or orienting calls to approach calls. We did not record a terminal phase before final acquisition of a fruit, as it is typical for aerial insectivorous bats prior to capture. Both bat species selected ripe over unripe fruit and non-infested over infested fruit. Artibeus watsoni preferred larger over smaller fruit. We conclude from our experiments, that the bats used a combination of odor-guided detection together with echolocation for localization in order to find ripe fruit and to discriminate among them. 相似文献
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The prenatal diagnosis by ultrasound of congenital chylothorax is described allowing early intervention immediately after delivery. Unilateral fluid collection in the right lung with marked displacement of the heart to the left were the most prominent sonographic signs. Post partum thoracocentesis and chylus fluid drainage served as a life saving procedure. 相似文献
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Shmuel Arnon Rami Aviram Tzipora Dolfin Rivka Regev Ita Litmanovits Ronnie Tepper Orly N. Elpeleg 《黑龙江环境通报》2002,22(1):34-37
We describe two newborn sisters who presented in the third trimester with diminished fetal movements and skin edema, but with no other signs of hydrops fetalis. Within hours of birth, both developed profound lactic acidemia, followed by multi-organ failure. In muscle mitochondria, the activity of all enzymatic complexes that contain mitochondrial DNA (mtDNA)-encoded subunits was markedly decreased. Southern blot analysis revealed a profound reduction in the mtDNA/nuclear DNA ratio, implying mtDNA depletion. The prenatal identification of skin edema in two patients with mtDNA depletion, and its absence in a healthy sibling, suggest that skin edema should be regarded as a novel manifestation of mtDNA depletion. This finding shows that mtDNA depletion can present prenatally and, consequently, may aid the clinician in making a diagnosis, prenatally, of this genetic defect. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Rahman Zia ur Ahmad Saeed Fidel Rivka Khalid Salma Ahmad Iqbal Humphrey Olivier S. Khan Hizbullah Khan Bushra 《Environmental geochemistry and health》2021,43(9):3615-3624
Environmental Geochemistry and Health - This study aimed to determine the status of groundwater contamination with faecal coliform and nitrate in the rural areas of Mardan district, Pakistan. Both... 相似文献