THE EFFECT OF SHEEP URINE ON THE GERIMINATION AND EARLY ESTABLISHMENT OF A COMMON WEED GRASS     

J. L. Wheeler 《Grass and Forage Science》1959,14(1):55-57

Sowings of annual meadow grass ( Poa annua ) were made in pots of soil which had been treated with sheep urine, with urine diluted × 50, or with water as a control. The treatments were applied before, at, and after sowing.
Urine, whether applied at sowing time, or eleven days before or after, significantly reduced the germination or establishment of the weed grass.
Diluted urine tended to reduce the number of established seedlings when applied at or shortly after sowing.
In a subsidiary experiment the number of viable seeds in soil taken from pastures which had received no urine for four years were compared with those from soil under pastures receiving urine. The difference was not significant.  相似文献   

Bilateral Testicular Mixed Germ Cell-sex Cord-stromal Tumours in a Stallion     

LFC Brito  JB Engiles  RM Turner  LM Getman  A Ebling 《Reproduction in domestic animals》2009,44(5):846-851

An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions.  相似文献   

Sustainable Environmental Education for a Sustainable Environment: Lessons from Thailand for Other Nations     

J. Gallagher  C. Wheeler  M. McDonough  B. Namfa 《Water, air, and soil pollution》2000,123(1-4):489-503

The Thailand Ministry of Education and Michigan State University collaborated to plan, design, implement, and evaluate this project in which school children and adults in 11 communities worked together to prevent forest degradation and improve forest quality. School children in grades 5 though 8 studied the causes and consequences of deforestation and forest degradation and brought the results of their investigations to local community members. This resulted in identification of local environmental problems that were forest-related and joint efforts in which adults and children worked together to resolve these problems. The results of this intergenerational work were very promising as children, adults, schools, communities, and the environment benefited from collaboration. Important lessons for others embarking this work are reported.  相似文献   

Glycoalkaloids in potato tubers grown under controlled environments     

Anadi Nitithamyong  Joachim H. Vonelbe  Raymond M. Wheeler  Theodore W. Tibbitts 《American Journal of Potato Research》1999,76(6):337-343

Tuber content of α-solanine, α-chaconine, and total glycoalkaloids (TGA) was determined for the potato cultivars, Norland, Russet Burbank, and Denali grown under different environmental conditions in growth chambers. The lowest TGA concentrations (0.30 to 0.35 mg g¹ dry tissue) were found in the cv. Norland with 400 μnol m^-2 s^-1 photosynthetic photon flux (PPF), 12 h day length, 16 C temperature, and 350 μmol mol^-1 carbon dioxide. The ratio of α-chaconine to α-solanine was close to 60:40 under all growing conditions, except that it was 50:50 under the low temperature of 12 C. Cultivars responded similarly to environmental conditions although TGA was about 20% greater in cv. Russet Burbank and about 30% greater in Denali compared to Norland. The largest changes in TGA occurred with changes in temperature. In comparison to 16 C, TGA were 40% greater at 12 C, 80% greater at 20 C, and 125% greater at 24 C (0.70 mgg ^-1 dry weight). The TGA concentratation increased from 10 to 25% with an increase in light from 400 to 800 μmol m^-2 s^-1 PPF for all three cultivars. TGA increased 20% with extension of the day length from 12 to 24 hr and also increased 20% when carbon dioxide was increased from 350 to 1000 umol mol^-1. TGA concentrations were not influenced by changes in relative humidity from 50 to 80%. TGA concentrations decreased only slightly in harvests made from 9 to 21 weeks after planting. Variations in TGA among the different growing conditions and cultivars were below 20 mg/100 g fresh weight (= 1.0 mg g^-1 dry weight) recognized as the upper concentration for food safety. However the results suggest that TGA should be considered when potatoes are grown at temperatures above 20 C.  相似文献   

Distribution of thiobacillus ferrooxidans and leptospirillum ferrooxidans: implications for generation of acid mine drainage   总被引：1，自引：0，他引：1  

MO Schrenk  KJ Edwards  RM Goodman  RJ Hamers  JF Banfield 《Science (New York, N.Y.)》1998,279(5356):1519-1522

Although Thiobacillus ferrooxidans and Leptospirillum ferrooxidans are widely considered to be the microorganisms that control the rate of generation of acid mine drainage, little is known about their natural distribution and abundance. Fluorescence in situ hybridization studies showed that at Iron Mountain, California, T. ferrooxidans occurs in peripheral slime-based communities (at pH over 1.3 and temperature under 30 degreesC) but not in important subsurface acid-forming environments (pH 0.3 to 0.7, temperature 30 degrees to 50 degreesC). Leptospirillum ferrooxidans is abundant in slimes and as a planktonic organism in environments with lower pH. Thiobacillus ferrooxidans affects the precipitation of ferric iron solids but plays a limited role in acid generation, and neither species controls direct catalysis at low pH at this site.  相似文献   

Do plant lice work subterraneously during extreme drouth?     

H. J. Wheeler 《American Journal of Potato Research》1923,1(2):16-16

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Report of the twenty-seventh annual meeting of the potato association of America     

E. J. Wheeler  H. F. Bailey  K. G. Buckley  H. O. Werner  J. C. Miller 《American Journal of Potato Research》1941,18(11):329-331

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Report of the twenty-fifth annual meeting of the Potato Association of America     

E. L. Newdick  F. M. Blodgett  Fred H. Bateman  Daniel Dean  E. J. Wheeler  E. V. Hardenburg 《American Journal of Potato Research》1939,16(11):304-307

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Progress made in the breeding program in Michigan in 1935     

E. J. Wheeler 《American Journal of Potato Research》1936,13(6):159-162

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Salmon of the Southeastern U.S.: Sucker migrations deliver resource subsidies to oligotrophic stream     

Mack White  Kit Wheeler  Ryan R. Hudson  Justin N. Murdock 《Ecology of Freshwater Fish》2023,32(1):181-194

The ability for migratory fishes to move commonly limiting resources such as nitrogen (N) and phosphorus (P) between discrete environments can have pronounced effects on recipient ecosystems. To further understand the geographic and taxonomic scope of migratory fish resource subsidies, we quantified N and P subsidies delivered by adfluvial suckers (Smallmouth Buffalo, Ictiobus bubalus) via excretion, eggs and carcasses to a small oligotrophic stream during their annual spawning migration. We also compared nutrient inputs from migrant buffalo with watershed nutrient export to assess the likelihood that delivered nutrients were ecologically important. We estimated that approximately 67,000 buffalo delivered 730 kg of N and 80 kg of P to Citico Creek as a result of excretion and egg subsidies across three migration waves. We estimated that carcasses delivered negligible amounts of N and P due to extremely low retention. The ratio of migrant inputs (M_w) to system export (E_w; M_w/E_w) varied amongst three migration waves and compounds (i.e. dissolved inorganic nitrogen, ammonium and soluble reactive phosphorus), with values for M_w/E_w ranging from 0.25 to 5.10, reflecting the potential of nutrient subsidies to exceed nutrients exported from the system under certain conditions. Our findings suggest that suckers have the potential to deliver large resource subsidies to their spawning habitats and that these subsidies may be ecologically important, thus warranting additional consideration of the functional relevance of nongame fishes and their migrations.  相似文献