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91.
Bartel N Bietenholz MF Rupen MP Beasley AJ Graham DA Altunin VI Venturi T Umana G Cannon WH Conway JE 《Science (New York, N.Y.)》2000,287(5450):112-116
Twenty consecutive Very Long Baseline Interferometry images of supernova 1993J from the time of explosion to the present show the dynamic evolution of the expanding radio shell of an exploded star. High-precision astrometry reveals that the supernova expands isotropically from its explosion center. Systematic changes in the images may reflect a pattern of anisotropies and inhomogeneities in the material left over from the progenitor star. As the shock front sweeps up the material in the surrounding medium, it is increasingly decelerated and influenced by the material. After 5 years, the supernova has slowed to half of its original expansion velocity and may have entered the early stages of the adiabatic phase common in much older supernova remnants in the Milky Way Galaxy. 相似文献
92.
Thomas C. Hutchinson Leah Bozic Guadalupe Munoz-Vegas 《Water, air, and soil pollution》1986,31(1-2):283-294
Seedlings of red, white and black spruce, and white and jack pine were tested for their response to a range of Al concentrations, when grown for 12 to 14 weeks in sand culture in the greenhouse. Nutrients were supplied in solution of pH 3.8 to which Al was supplied at 0, 5, 10, 20, 40, 80 and 160 mg/L. Red and white spruce were inhibited in growth from 5 mg/L upwards, while black spruce was equally inhibited only at concentrations > 20 mg/L. In contrast, white pine was stimulated by 5 to 20 mg Al/L and was always more tolerant than the other 4 species at every Al level used. Jack pine was intermediate in its response. There was a positive linear relationship between P and Al accumulation in the shoots of red spruce. This was in contrast to the other 4 species in which P concentrations in the shoot decreased with an increase in Al concentrations. In localization studies on jack pine using a modified hematoxylin stain, Al was shown to accumulate in the root cap of root tips, and in the epidermal and outer cortical walls of older roots. EDAX-SEM analysis confirmed the tissue distribution of Al and revealed its coincidental distribution with. P in roots. 相似文献
93.
Lionel Sebbag Leah M. Moody Rachel A. Allbaugh Jonathan P. Mochel 《Veterinary ophthalmology》2020,23(1):199-204
Impairment of corneal nerves can result in the development of ocular surface diseases such as aqueous tear deficiency and neurotrophic keratopathy. This study investigates oral nicergoline, an α‐adrenoceptor antagonist shown to enhance endogenous secretion of nerve growth factor (NGF) by the lacrimal gland, as a potential therapy for these conditions. Five female spayed Beagle dogs received a 2‐week course of oral nicergoline (10 mg twice daily). Drug safety was evaluated with ophthalmic and physical examinations, blood pressure monitoring, bloodwork, and urinalysis. The effect of nicergoline on the ocular surface was assessed with corneal esthesiometry, Schirmer tear test‐1, and tear film breakup time. Drug effect on NGF levels was assessed by collecting tears and blood at baseline and completion of therapy using a bead‐based immunoassay and an enzyme‐linked immunosorbent assay. Although nicergoline was well tolerated in all dogs, it did not have a significant impact on corneal sensitivity, tear production, or tear stability. Of note, NGF was below the limit of quantification in all tear samples and was only detected in 8/20 serum samples with no significant difference between levels at baseline (189.4 ± 145.1 pg/mL) and completion of therapy (149.4 ± 79.4 pg/mL). Further validation of NGF analytical assays is warranted before nicergoline is investigated in clinical patients. 相似文献
94.
Colin G. Moore Dan B. Harries Alastair R. Lyndon Graham R. Saunders Terence R. Conway 《水产资源保护:海洋与淡水生态系统》2003,13(2):137-146
- 1. The large size, patchiness and fragility of serpulid reefs present difficulties for the measurement of reef coverage for mapping and monitoring studies. Video transect measures of cover are assessed in terms of accuracy and sensitivity of the method for the identification of spatial or temporal changes.
- 2. By comparison with direct in situ measurement of reef cover, it was found that still photography was capable of providing an accurate means for the measurement of the seabed coverage by individual reefs.
- 3. By comparison of video and still photographic measurement of reef cover, it was found that video transects were capable of providing cover estimates of sufficient accuracy for conservation purposes, differing from still photographic estimates by 0.3% cover.
- 4. Power analysis was employed on replicate video estimates of reef cover in order to determine the degree of replication required to identify different levels of spatial or temporal change in cover using video transects of different lengths. The modest level of replication required to identify changes in coverage as small as 25% of the initial value suggests that the use of video transects offers great potential in monitoring and mapping studies.
95.
96.
A 2-year-old, female spayed, domestic shorthair cat presented to the University of Missouri-Veterinary Medical Teaching Hospital (UMC-VMTH) with an approximately 11-month history of fluid-draining pockets along her ventral thorax and axillae. The skin in these regions was erythematous, and multiple areas drained a serous to serosanguinous fluid. Fluid-filled, nodules formed along the ventrum, but these nodules disappeared as fluid drained spontaneously. Histologic assessment of skin biopsies revealed areas of vascular proliferation extending along the deep margin of the section and rare instances of invasion into the superficial dermis. These vascular channels were devoid of cells, lined by variably pleomorphic endothelial cells which had a low mitotic index. Based on the mild to moderate pleomorphism, positive staining with prospero-related homeobox gene-1 (PROX-1), and the locally aggressive nature of the tumor, a final diagnosis of lymphangiosarcoma was made. 相似文献
97.
Leah A Cohn Anthony T Gary William H Fales Richard W Madsen 《Journal of veterinary diagnostic investigation》2003,15(4):338-343
Fluoroquinolone (FQ) antimicrobial agents are used extensively in human and veterinary medicine. Widespread use of any antimicrobial agent can apply selective pressure on populations of bacteria, which may result in an increase in the prevalence of antimicrobial-resistant isolates. Antimicrobial-susceptibility data on bacteria isolated from the canine urinary tract by the University of Missouri-Columbia Veterinary Medical Diagnostic Laboratory, Columbia, MO, were used to determine whether there has been an increase in the prevalence of FQ-resistant bacteria over time. Between January 1992 and December 2001, minimum inhibitory concentrations of either ciprofloxacin (1992-1998) or enrofloxacin (1998-2001) were determined for 1,478 bacterial isolates from the canine urinary tract. The predominant bacterial species isolated were Escherichia coli (547 isolates), Proteus mirabilis (156), and Staphylococcus intermedius (147). In all, there were 13 bacterial species with more than 25 isolates each. A significant increase in the overall proportion of resistant bacterial isolates was documented from 1992 to 2001 (Cochran-Armitage test for trend, P < 0.0001). The same increase in resistant isolates was documented when either ciprofloxacin or enrofloxacin was analyzed separately (P < 0.0001 and P < 0.0002, respectively). No difference was detected in rates of bacterial FQ resistance with regard to the sex of the dog from which the bacteria were isolated. The frequency with which some bacterial species were isolated differed with the sex of the infected dog. Proteus mirabilis was found more often in females (P < 0.0001), whereas beta hemolytic Streptococcus spp., were found more often in males (P = 0.0003). Although the overall efficacy of FQ antimicrobials remained high with greater than 80% of isolates being susceptible, the data demonstrated an increase in the proportion of resistant bacteria isolated from the urinary tract of the dog. 相似文献
98.
Paige Langdon Leah A Cohn John M Kreeger Nelson H Priddy 《Journal of the American Animal Hospital Association》2002,38(1):21-27
Acquired portosystemic shunts (PSS) are a clinical entity distinct from congenital PSS. Their apparent incidence in cats is low, which may reflect the rarity of predisposing hepatic parenchymal disease, such as cirrhosis, in this species. Two cats with acquired PSS associated with primary hepatobiliary disease are described. Relevant findings in acquired PSS are discussed, as are potential reasons for the apparently low incidence in the cat. 相似文献
99.
K. R. Simon Ascher Manes Wysoki Nadia E. Nemny Leah Gur-Telzak 《Pest management science》1978,9(3):219-224
Small (70 mg) Boarmia selenaria larvae fed for 4 days on avocado leaves or alfalfa dipped in aqueous diflubenzuron suspensions suffered from severe developmental disturbances. Similar results were obtained with leaves sprayed in an avocado orchard, with which, in addition, the considerable persistence of diflubenzuron under field conditions could be demonstrated. The substance was also active by topical application against large (500–600 mg) B. selenaria larvae, whereas by contact it was only moderately toxic. Some other non-conventional control agents, viz., the antifeedant AC-24055 and several juvenile hormone analogues, were of medium and negligible activity, respectively, against this insect. 相似文献
100.
Gentallan Renerio P. Bartolome Michael Cedric B. Cejalvo Reneliza D. Timog Emmanuel Bonifacio S. Altoveros Nestor C. Borromeo Teresita H. Endonela Leah E. 《Genetic Resources and Crop Evolution》2021,68(7):2767-2773
Genetic Resources and Crop Evolution - Combretum indicum (L.) DeFilipps seeds have anthelmintic properties and are recognized to be medicinal; however, the array of their morphological characters,... 相似文献