Comment on "The response of vegetation on the Andean flank in western Amazonia to Pleistocene climate change"     

Punyasena SW  Dalling JW  Jaramillo C  Turner BL 《Science (New York, N.Y.)》2011,333(6051):1825; author reply 1825

Cárdenas et al. (Reports, 25 February 2011, p. 1055) used the presence of Podocarpus pollen and wood to infer ≥5°C cooling of Andean forests during Quaternary glacial periods. We show that (i) Podocarpus has a wide elevation range in the Neotropics, and (ii) edaphic factors cannot be discounted as a factor governing its distribution. Paleoecologists should therefore reevaluate Podocarpus as a cool-temperature proxy.  相似文献   

Sustainability. Paying for ecosystem services--promise and peril     

Kinzig AP  Perrings C  Chapin FS  Polasky S  Smith VK  Tilman D  Turner BL 《Science (New York, N.Y.)》2011,334(6056):603-604

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On predicting the presence of birds in Eucalyptus forest types     

L. W. Braithwaite  M. P. Austin  M. Clayton  J. Turner  A. O. Nicholls 《Biological conservation》1989,50(1-4):33-50

We examine the relationship between the number of bird species and environment within 500 000 ha of eucalypt forests in south-eastern New South Wales, Australia. Birds were surveyed at 39 sites within 31 eucalypt communities, which were, in turn, scored by altitude, temperature, rainfall, basal areas of trees and levels of the nutrients nitrogen, phosphorus, potassium and magnesium in the eucalypt foliage.

Ninety bird species were recorded. Numbers per site, averaged over the whole sample period, ranged between 20 and 38 over all surveys, 24 and 42 in ‘summer’ (October to March) when migrant species were present, and 13 and 38 in ‘winter’ (April to September). A forward stepwise Poisson regression model was used to fit bird species richness to the environmental variables. Over all surveys and in ‘summer’, foliar magnesium and tree basal area (including the basal area of dead trees) were significantly (positive) correlated with the number of bird species. In ‘winter’ the correlations were with altitude and temperature (both negative), presumably the result of emigration of species that avoid cold weather, and tree basal area (positive).

The positive association of number of species over all surveys and in ‘summer’ with tree basal area, including dead trees, and foliar magnesium may index the level of forest maturity and productivity.

Forest management directed solely to timber production reduces the basal area and the number of dead trees and may thereby reduce bird species richness permanently.

A methodology is offered, based on the relationship between the physical environment and the more productive eucalypt communities, for determining forest areas containing the most species of birds.  相似文献   

Irreversibility of sulfate sorption on goethite and hematite     

Laurie J. Turner  James R. Kramer 《Water, air, and soil pollution》1992,63(1-2):23-32

Sulfate ion adsorption and desorption experiments carried out on synthetic goethite and hematite and natural hematite show adsorption to be a highly irreversible reaction. All oxides showed an increase in sulfate ion adsorption with decrease in pH. Only a small fraction of sorbed sulfate was desorbable after 48 hr, and only at a pH of 3. Extreme irreversibility of sulfate sorption on these common soil minerals suggests that adsorbed sulfate is more immobile in watersheds than previously considered and that recovery models which inherently assume reversibility may need to be modified.  相似文献   

High pressure liquid chromatographic determination of zearalenone in chicken tissues   总被引：1，自引：0，他引：1  

G V Turner  T D Phillips  N D Heidelbaugh  L H Russell 《Journal of the Association of Official Analytical Chemists》1983,66(1):102-104

A method is reported for the extraction and analysis of zearalenone in chicken fat, heart muscle, and kidney tissue by using high pressure liquid chromatography (HPLC). Zearalenone is extracted with acetonitrile, cleaned up with hexane, and extracted further with ethyl acetate. Zearalenone is determined by HPLC using a reverse phase radial compression separation system, an ultraviolet absorbance detector, and a mobile phase of acetonitrile-water (60 + 40) (v/v). Recoveries of zearalenone added at levels from 50 to 200 ng/g are in the range 82.6-95.1%.  相似文献   

Meiotic Response of In vitro Matured Canine Oocytes under Different Proteins and Heterologous Hormone Supplementation   总被引：2，自引：0，他引：2  

BA Rodrigues  JL Rodrigues 《Reproduction in domestic animals》2003,38(1):58-62

The impact of TCM‐199 supplemented with different proteins and heterologous hormones on the in vitro maturation (IVM) rate of bitch oocytes was evaluated by nuclear staining under fluorescence microscopy. Oocytes were recovered by slicing of ovaries from bitches presented at various stages of oestrous cycle to ovariohysterectomy. The basic culture medium was TCM‐199 supplemented with 25 mM Hepes/l, with 10% heat‐inactivated oestrous cow serum (ECS), 50 μg/ml gentamicin, 2.2 mg/ml sodium bicarbonate and 22‐μg/ml pyruvic acid, 1.0‐μg/ml oestradiol (E 8875; Sigma), 0.5‐μg/ml follicle‐stimulating hormone (FSH) (Folltropin‐V; Vetrepharm Inc., Ontario, Canada) and 0.03 IU/ml human gonadotropin (hCG) (Profasi HP; Serono, Aubonne, Switzerland). Oocytes were distributed randomly between basic culture medium (control) and the corresponding experimental treatment. Hormone treatments were: oocytes cultured in; (1) medium without FSH, (2) control medium supplemented with 20 μg/ml oestradiol, or (3) medium supplemented with 1 μg/ml human somatotropin (hST; Humatrope, Lilly, Saint Cloud, France). The second experiment consisted of oocytes cultured in medium supplemented with 0.4% (w/v) bovine serum albumin (BSA, fraction V; Gibco Grand Island, NY, USA) instead of ECS, or oocytes cultured in medium with 10% inactivated oestrous bitch serum (EBS) instead of ECS. Oocytes were cultured in 100 μl droplets (up to 25 oocytes per drop) under mineral oil at 37°C in a 100% humidified atmosphere containing 5% CO₂ in air. After 72 h of IVM, the highest rates (p < 0.05) of meiotic resumption were achieved with the 0.4% BSA supplementation. A positive influence on the metaphase II (MII) acquisition rate was observed with hST supplement. Oocytes cultured with 10% EBS supplementation did not develop to the MII stage. The results in this study show that the protein and hormone supplements to TCM‐199 culture medium tested did not promote the final steps of IVM of bitch oocytes.  相似文献   

Canine conjunctival papilloma: A review of five cases   总被引：1，自引：0，他引：1  

J. Sansom  K. C. Barnett  A. S. Blunden  K. C. Smith  S. Turner  L. Waters 《The Journal of small animal practice》1996,37(2):84-86

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A Technician''s Guide to Exotic Animal Care          下载免费PDF全文

Dr. Patricia Turner 《The Canadian veterinary journal. La revue veterinaire canadienne》2003,44(2):155

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A Technician''s Guide to Exotic Animal Care          下载免费PDF全文

Patricia Turner 《The Canadian veterinary journal. La revue veterinaire canadienne》2002,43(3):216

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Internal fixation of a greater tubercle fracture in an adolescent horse: A case report     

Ragan Adams MA  DVM  Tracy A. Turner DVM  MS 《Journal of Equine Veterinary Science》1987,7(3)

This report describes the diagnosis of a fracture of the greater tubercle of the humerus and successful repair with 2 cancellous bone screws in a 420 kg adolescent horse.  相似文献