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51.
Umina PA Weeks AR Kearney MR McKechnie SW Hoffmann AA 《Science (New York, N.Y.)》2005,308(5722):691-693
Geographical clines in genetic polymorphisms are widely used as evidence of climatic selection and are expected to shift with climate change. We show that the classic latitudinal cline in the alcohol dehydrogenase polymorphism of Drosophila melanogaster has shifted over 20 years in eastern coastal Australia. Southern high-latitude populations now have the genetic constitution of more northerly populations, equivalent to a shift of 4 degrees in latitude. A similar shift was detected for a genetically independent inversion polymorphism, whereas two other linked polymorphisms exhibiting weaker clinal patterns have remained relatively stable. These genetic changes are likely to reflect increasingly warmer and drier conditions and may serve as sensitive biomarkers for climate change. 相似文献
52.
Nitrate Toxicity to Five Species of Marine Fish 总被引:2,自引:0,他引:2
Richard H. Pierce Jason M. Weeks James M. Prappas 《Journal of the World Aquaculture Society》1993,24(1):105-107
53.
Dicamba resistance: enlarging and preserving biotechnology-based weed management strategies 总被引:1,自引:0,他引:1
Behrens MR Mutlu N Chakraborty S Dumitru R Jiang WZ Lavallee BJ Herman PL Clemente TE Weeks DP 《Science (New York, N.Y.)》2007,316(5828):1185-1188
The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast-encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are examined. 相似文献
54.
55.
TJ Portas TB Hildebrandt BR Bryant F Göritz R Hermes 《Australian veterinary journal》2010,88(1-2):57-60
A testicular mass was identified by ultrasonography performed during a routine reproductive evaluation of an adult male southern black rhinoceros ( Diceros bicornis minor ). Histological examination of a testicular biopsy supported a presumptive diagnosis of testicular neoplasia. Hemi-castration was performed to excise the affected testis and a pathological diagnosis of a seminoma was made. Assessment of semen suggested reduced fertility as a consequence of the neoplastic process, but hemi-castration prevented further growth and metastasis of the tumour and ensured the animal's breeding potential. This is the second documented case of a seminoma in a rhinoceros species and the first case in a black rhinoceros. 相似文献
56.
We evaluated the expression of vimentin, S100a, and Melan A/MART-1 (melanoma antigen recognized by T cells 1) in seven cell lines established independently from dogs with canine melanoma. We also compared routine immunostaining of 29 clinical specimens from melanoma cases using vimentin, S100a, and neuron-specific enolase (NSE) with staining for Melan A/MART-1 as part of a diagnostic panel. All the cell lines were positive for expression of vimentin and S-100a. MelanA/MART-1 expression was seen consistently in only two of the seven cell lines. Staining for Melan A/MART-1 was most intense near areas of heavy melanin pigmentation. All except one of the clinical specimens were positive for vimentin. S 100a was expressed in the majority of both pigmented (15/20, 75%) and amelanotic (8/9, 88.8%) tumors. Seventeen of 29 (58.6%) tumors were positive for NSE. Melan A/MART-1 was expressed in 18/29 (62%) tumors, including 90% of pigmented tumors, but in no amelanotic tumors. Intensity of Melan A/MART-1 staining correlated positively with biologic behavior, with seven malignant tumors showing negative to weak staining and 10 benign tumors showing moderate to strong staining. Three malignant tumors showed moderate to intense staining for Melan A/ MART-1. Our results suggest that expression of Melan A/MART-1 may be unstable in cultured cell lines. Assessment of both S100a and Melan A/MART-1 expression is useful to confirm a diagnosis of canine melanoma, and Melan A/MART-1 may be especially informative regarding the biologic behavior of these tumors. 相似文献
57.
A blue-naped mousebird (Urocolius macrourus) was diagnosed by gross necropsy and histopathology as having a chronic, fibrosing bacterial cholecystitis. Acute, severe, necrotizing pneumonia and myocarditis also were present with intralesional gram-negative bacteria. The bacteria within the lungs and heart were suspected to have spread from the biliary tract because of the pattern of distribution and similar gram-staining characteristics. Enterobacter sp. and Escherichia coli were cultured from the pulmonary lesions. Cloacal cultures in clinically normal blue-naped mousebirds and speckled mousebirds (Colius striatus) yielded both Enterobacter sp. and E. coli. We hypothesize a pathogenesis in this bird consisting of biliary stasis of unknown etiology and eventual infection of the biliary tract by the normal gram-negative gastrointestinal flora. Death was believed to be a result of cardiac and respiratory dysfunction secondary to the bacterial dissemination from the biliary tree and endotoxemia. 相似文献
58.
Long-acting selenium treatments for sheep 总被引:1,自引:0,他引:1
An intraruminal selenium (Se) pellet and a subcutaneous depot of barium selenate, equivalent to 1.6 mg Se/kg body weight, were each effective in maintaining increased blood Se concentrations for at least 200 weeks in ewes at pasture. These treatments given to the ewes 23 to 26 weeks before lambing increased the Se status of their lambs for 4 to 6 months. 相似文献
59.
Paramagnetic resonance spectra of Apollo 11 fines and rocks were measured at 9 and 35 gigahertz and at 4 degrees , 80 degrees , and 300 degrees K. At both frequencies the material has an intense absorption at g = 2, with a line width of approximately 950 gauss. Fe ions with strong exchange interactions produce this resonance. A comparison of the resonance absorption due to Fe(3+) showed that the energy of the crystal field interaction was approximately 0.1 per centimeter. Mn(2+) was identified in several samples, and an absorption at g = 1.89 was tentatively attributed to Ti(3+). The nuclear magnetic resonance spectra of (27)Al had a distribution of asymmetry parameters eta ranging from 0.25 to 0.75 and had nuclear quadrupole coupling constants e(2)qQ/h of approximately 3 megahertz. 相似文献
60.
Feasibility of using foam fractionation for the removal of dissolved and suspended solids from fish culture water 总被引:4,自引:0,他引:4
The results of an experimental study on the feasibility of foam fractionation to remove suspended and dissolved solids from fish culture water are presented. Foam fractionation was found to concentrate volatile solids (VS), total Kjeldahl nitrogen (TKN), and total suspended solids (TSS) in the foam condensate. Foam fractionation did not concentrate fixed solids (FS). Air flow rate and overflow height were found to be important operational factors in determining condensate concentration, condensate production and removal rates of VS. Predictive regression equations are presented to predict the performance of a typically configured foam fractionation device. Measurements of TKN and TSS in the foam condensate and fish culture water were well correlated with VS, indicating that VS measurements can be used to predict concentrations and removal rates of both TKN and TSS from fish culture waters that are similar to those analyzed. 相似文献