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61.
Peridotite xenoliths from the Cascade arc in the United States and in the Japan arc have neodymium and osmium isotopic compositions that are consistent with addition of 5 to 15 percent of subducted material to the present-day depleted mantle. These observations suggest that osmium can be partitioned into oxidized and chlorine-rich slab-derived fluids or melts. These results place new constraints on the behavior of osmium (and possibly other platinum group elements) during subduction of oceanic crust by showing that osmium can be transported into the mantle wedge. 相似文献
62.
The ultraviolet receptor of bird retinas 总被引:4,自引:0,他引:4
The eyes of 15 species of birds from 10 families have some cones maximally sensitive at 370 nanometers in the near-ultraviolet. Spectral sensitivity was measured by recording extracellularly in opened eyecups , and a maximum in the ultraviolet was revealed by selectively adapting the retina with yellow background lights. The 370-nanometer spectral sensitivity function is attributed to receptors because its spectral position does not vary with the strength of adaptation and because it is present when the receptor potentials are isolated from the contributions of higher order retinal neurons by exposing the retina to sodium aspartate. These measurements demonstrate the basis for the ultraviolet sensitivity of birds that has been seen in behavioral experiments, and they provide further evidence that many vertebrates share with insects vision in the near-ultraviolet. 相似文献
63.
Fetterman HR Koepf GA Goldsmith PF Clifton BJ Buhl D Erickson NR Peck DD McAvoy N Tannenwald PE 《Science (New York, N.Y.)》1981,211(4482):580-582
A submillimeter heterodyne radiometer, developed for astronomical applications, uses an optically pumped laser local oscillator and a quasi-optical Schottky diode mixer. The resultant telescope-mounted system, which has a noise temperature less than 4000 K (double sideband) and high frequency and spatial resolution, has been used to detect the J = 6 --> 5 rotational transition of carbon monoxide at 434 micrometers in the Orion molecular cloud. The measurements, when compared with previous millimeter-wave data, indicate that the broad carbon monoxide emission feature is produced by an optically thin gas whose temperature exceeds 180 K. 相似文献
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65.
Yamada K Lim J Dale JM Chen H Shinn P Palm CJ Southwick AM Wu HC Kim C Nguyen M Pham P Cheuk R Karlin-Newmann G Liu SX Lam B Sakano H Wu T Yu G Miranda M Quach HL Tripp M Chang CH Lee JM Toriumi M Chan MM Tang CC Onodera CS Deng JM Akiyama K Ansari Y Arakawa T Banh J Banno F Bowser L Brooks S Carninci P Chao Q Choy N Enju A Goldsmith AD Gurjal M Hansen NF Hayashizaki Y Johnson-Hopson C Hsuan VW Iida K Karnes M Khan S Koesema E Ishida J Jiang PX Jones T Kawai J Kamiya A Meyers C Nakajima M 《Science (New York, N.Y.)》2003,302(5646):842-846
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67.
Goldsmith T 《Science (New York, N.Y.)》2002,297(5588):1769
68.
The compound eye of the cockroach Periplaneta has receptors for ultraviolet light (maximum sensitivity at 365 nanometers) and green light (maximum sensitivity at 510 nanometers). Single photoreceptor cells in the compound eye were impaled, identified by spectral response, and marked with dye-filled microelectrodes. Using two diferent dyes, we showed that both types of receptors can be found in the same ommatidium. 相似文献
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70.
Abstract CASE HISTORY: In 2008, a 3-year-old female Labrador Retriever was presented for routine breeding soundness evaluation. CLINICAL FINDINGS: Vaginal endoscopy revealed an 8-cm long and 1-cm thick vaginal septum. Surgical resection of the septum was performed under general anaesthesia using a bipolar high-frequency resectoscope. Three months later the bitch was naturally mated and subsequently delivered five male and two female puppies without complications. Both female puppies were examined at the age of 12 and 15 months and showed a vaginal septum with a diameter of 0.3 and 0.5 cm, respectively. DIAGNOSIS: Vaginal septa in three related bitches. CLINICAL RELEVANCE: This is the first report describing the use of a bipolar high-frequency resectoscope for vaginal surgery in dogs. The septum could be resected quickly, with preservation of surrounding structures. Furthermore, it is the first report collecting information about familial presentation of vaginal septa in female dogs. Based on this case, we suggest that consideration should be given to the possible risk of inheritance of vaginal septa before considering surgical resection and breeding of female dogs. 相似文献