Sectional notes     

M. A. Lindsay  C. H. Metzger  B. A. Brown  Eugene W. Whitman  W. B. Ward  John S. Gardner  A. G. Tolaas  Marx Koehnke  J. C. Campbell  H. R. Talmage  E. V. Hardenburg  C. A. Henderson  H. L. Bailey 《American Journal of Potato Research》1944,21(9):261-268

  相似文献   

Sectional notes     

E. Marx  C. H. Metzger  B. A. Brown  Eugene W. Whitman  H. R. Talmage  Frank W. Hussey  H. A. Reiley  Marx Koehnke  J. C. Campbell  E. V. Hardenburg  Karl H. Fernow  Earl B. Tussing  E. R. Jackman  C. A. Henderson  O. D. Burke  K. W. Lauer  John Noonan  H. L. Bailey  Chas D. Gaines  W. N. Keenan  R. E. Goodin 《American Journal of Potato Research》1943,20(8):224-236

  相似文献   

Concerning “lost” potato acres     

B. E. Brown 《American Journal of Potato Research》1943,20(10):283-289

  相似文献   

Erratum     

T. P. Dykstra  L. M. Black  Arthur Hawkins  J. A. Chucka  B. E. Brown  J. H. Jensen  R. W. Goss  C. L. Fitch  Frank W. Hussey  H. A. Reiley  Eral B. Tussing  J. B. R. Dickey  K. W. Lauer  T. E. Odland 《American Journal of Potato Research》1941,18(9):271-271

  相似文献   

Further studies on the placement of fertilizer for potatoes     

B. E. Brown  H. H. Zimmerley  G. V. C. Houghland  W. H. Redit  L. G. Schoenleber 《American Journal of Potato Research》1939,16(4):81-93

  相似文献   

Quantifying the condition of Hawaiian coral reefs     

Ku'ulei S. Rodgers  Paul L. Jokiel  Christopher E. Bird  Eric K. Brown 《水产资源保护:海洋与淡水生态系统》2010,20(1):93-105

  相似文献   

Changes in thyroid hormone levels in eggs and larvae and in iodide uptake by eggs of coho and chinook salmon,Oncorhynchus kisutsch andO. tschawytscha     

Mike Greenblatt  Christopher L. Brown  Michael Lee  Silvia Dauder  Howard A. Bern 《Fish physiology and biochemistry》1989,6(5):261-278

Developmental profiles of thyroxin (T₄), triiodothyronine (T₃) and radioactive iodide uptake were established for eggs and T₄ and T₃ profiles were established for larvae (whole-body, yolk-only and body-only) of coho and chinook salmon. T₄ and T₃ were consistently present in all samples. In eggs, hormone levels remained fairly constant in all cohorst for at least the first three weeks of incubation, but then fluctuated in both directions in some sample groups. Large increases in T₄ (from 9 ng/g to 245 ng/g) were seen in 1985 chinook eggs 28 days after fertilization. Radioactive iodide uptake (which was used as a possible indicator of thyroxinogenesis) increased at least 10-fold in both 1986 coho and chinook eggs from 23–30 days after fertilization. T₄ (62 ng/g) and T₃ (393 ng/g) were found in the bodies of 28-day-old 1986 chinook embryos. In whole larvae, hormone levels varied depending upon the cohort studied. In general, initial body-only concentrations of both T₄ and T₃ decreased as body weight increased, but before yolksac resorption was completed, both thyroid hormone content and concentration increased (except for chinook T₃). T₄ and T₃ content in larval yolk stayed constant as yolksac size decreased, resulting in increased thyroid hormone concentration in the yolksac. All of these data suggest that the initial source of thyroid hormones in coho and chinook salmon eggs is maternal, but that by approximately 3–4 weeks after fertilization, the developing embryos begin to produce their own thyroid hormones. After hatching, increases in tissue T₄ and T₃ concentration coupled with constant T₄ and T₃ content in diminishing yolksacs suggest that larvae also produce their own thyroid hormones; yolksac content then may reflect both the original maternal hormones and the larva-producted hormones.  相似文献   

Spatial variability of common carp populations in relation to lake morphology and physicochemical parameters in the upper Midwest United States     

M. J. Weber  M. L. Brown  D. W. Willis 《Ecology of Freshwater Fish》2010,19(4):555-565

Weber MJ, Brown ML, Willis DW. Spatial variability of common carp populations in relation to lake morphology and physicochemical parameters in the upper Midwest United States.
Ecology of Freshwater Fish 2010: 19: 555–565. © 2010 John Wiley & Sons A/S Abstract – Common carp (Cyprinus carpio) is a widespread invasive species that is tolerant of a wide range of environmental conditions. Despite the circumpolar distribution of the species, limited information is available describing factors related to spatial variation in population characteristics. Eighty‐four lakes and impoundments in the upper Midwest United States were sampled to investigate the relationships of common carp relative abundance with size structure, condition and growth rates. We also investigated abiotic factors (lake morphology, physical solids and water quality) that may broadly influence common carp populations. Common carp size structure and condition were inversely related to relative abundance. Common carp relative abundance increased and size structure shifted to smaller individuals with increased lake depth, whereas lake surface area, watershed:surface area ratio and physical solids were also important in explaining common carp abundance and size structure. Common carp condition was best explained by water quality parameters and increased with metrics of lake productivity. We conclude that knowledge of factors associated with variation in common carp populations among lakes provides insights into the autecology and broad provisions for management of this generalist invasive species.  相似文献   

Mode of action,crop selectivity,and soil relations of the sulfonylurea herbicides     

Hugh M. Brown 《Pest management science》1990,29(3):263-281

The sulfonylurea herbicides are characterized by broad-spectrum weed control at very low use rates (c. 2–75 g ha^?1), good crop selectivity, and very low acute and chronic animal toxicity. This class of herbicides acts through inhibition of acetolactate synthase (EC 4.1.3.18; also known as acetohydroxyacid synthase), thereby blocking the biosynthesis of the branched-chain amino acids valine, leucine and isoleucine. This inhibition leads to the rapid cessation of plant cell division and growth. Crop-selective sulfonylurea herbicides have been commercialized for use in wheat, barley, rice, corn, soybeans and oilseed rape, with additional crop-selective compounds in cotton, potatoes, and sugarbeet having been noted. Crop selectivity results from rapid metabolic inactivation of the herbicide in the tolerant crop. Under growth-room conditions, metabolic half-lives in tolerant crop plants range from 1–5 h, while sensitive plant species metabolize these herbicides much more slowly, with half-lives > 20 h. Pathways by which sulfonylurea herbicides are inactivated among these plants include aryl and aliphatic hydroxylation followed by glucose conjugation, sulfonylurea bridge hydrolysis and sulfonamide bond cleavage, oxidative O-demethylation and direct conjugation with (homo)glutathione. Sulfonylurea herbicides degrade in soil through a combination of bridge hydrolysis and microbial degradation. Hydrolysis is significantly faster under acidic (pH 5) than alkaline (pH 8) conditions, allowing the use of soil pH as a predictor of soil residual activity. Chemical and microbial processes combine to give typical field dissipation half-lives of 1–6 weeks, depending on the soil type, location and compound. Very short residual sulfonylurea herbicides with enhanced susceptibility to hydrolysis (DPX-L5300) and microbial degradation (thifensulfuron-methyl) have been developed.  相似文献   

Tobacco rattle virus serotypes and associated nematode vector species of Trichodoridae in the bulb-growing areas in the Netherlands   总被引：1，自引：0，他引：1  

A. T. Ploeg  C. J. Asjes  D. J. F. Brown 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(5):311-319

Soil samples from the coastal bulb-growing areas in the provinces of North- and South-Holland and the North-East Polder in the Netherlands were examined for trichodorid nematodes and tobacco rattle virus (TRV) serotypes. At least one of a total of eight species of Trichodoridae, of whichParatrichodorus pachydermus was most prevalent, was found in 93% of the samples from the provinces of North- and South-Holland and TRV, including four serotypes, was obtained from 49% of these samples. In the North-East Polder one of three species of trichodorids, of whichP. teres occurred most frequently, was present in 72% of the samples, and TRV of one serotype was obtained from 28% of these samples. The TRV isolates recovered from these samples reacted serologically with one of four antisera to strains of TRV. Virus transmitted byP. pachydermus reacted to the PRN-, byTrichodorus viruliferus to the RQ-, byP. teres to the N5- and byT. similis, to the TS-antiserum, respectively.  相似文献