A REVIEW OF BRACKEN* POISONING IN CATTLE     

J. T. Stamp 《Grass and Forage Science》1947,2(4):191-194

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Computer simulation of the interactions of glyphosate with metal ions in phloem     

Harris WR  Sammons RD  Grabiak RC  Mehrsheikh A  Bleeke MS 《Journal of agricultural and food chemistry》2012,60(24):6077-6087

Essential nutrients such as trace metal ions, amino acids, and sugars are transported in the phloem from leaves to other parts of the plant. The major chelating agents in phloem include nicotianamine, histidine, cysteine, glutamic acid, and citrate. A computer model for the speciation of metal ions in phloem has been used to assess the degree to which the widely used herbicide glyphosate binds to Fe(3+), Fe(2+), Cu(2+), Zn(2+), Mn(2+), Ca(2+), and Mg(2+) in this fluid over the pH range of 8 to 6.5. The calculations show that glyphosate is largely unable to compete effectively with the biological chelating agents in phloem. At a typical phloem pH of 8, 1.5 mM glyphosate binds 8.4% of the total Fe(3+), 3.4% of the total Mn(2+), and 2.3% of the total Mg(2+) but has almost no effect on the speciation of Ca(2+), Cu(2+), Zn(2+), and Fe(2+). As the pH decreases to 6.5, there are some major shifts of the metal ions among the biological chelators, but only modest increases in glyphosate binding to 6% for Fe(2+) and 2% for Zn(2+). The calculations also indicate that over 90% of the glyphosate in phloem is not bound to any metal ion and that none of the metal-glyphosate complexes exceed their solubility limits.  相似文献   

Sediment imbalances and flooding risk in European deltas and estuaries     

Albert Rovira  Rhoda Ballinger  Carles Ibáñez  Paul Parker  M. Dolores Dominguez  Xavier Simon  Andrzej Lewandowski  Boris Hochfeld  Marian Tudor  Liesbeth Vernaeve 《Journal of Soils and Sediments》2014,14(8):1493-1512

Purpose

We analysed the status of current water and sediment management practices in six deltas and estuaries, which were part of the European DELTANET, INTERREG-funded network.

Materials and methods

These systems—the Danube, Ebro and Vistula deltas and the Elbe, Minho and Severn estuaries—represent different geographic regions of Europe. This enables comparison between the sites’ approaches to common coastal issues, notably those associated with sediment budgets, contamination and flood risk. Based on documentary analysis, workshop events and expert discussion, we employ a simple classification scheme to distinguish between levels of risk from these aspects.

Results

We suggest that flood risk is the most significant risk, followed by upstream sediment retention and sediment aggradation. Chemical contamination, though less severe, is not unimportant. Key management issues include a lack of environmental quality standards for sediment and suspended particulate matter, as well as the limited deployment of monitoring programmes, regular sediment sampling and associated chemical analyses.

Conclusions

These include both general and specific recommendations. Within these, the limited scope of integrated plans that aim for sustainability of the respective systems is highlighted. It is suggested that these do not challenge traditional, classical engineering approaches sufficiently. Nor do they address the origin of many environmental problems, especially those which are closely linked to short-term political and economic priorities.  相似文献   

First documented Capnocytophaga canimorsus infection in a species other than humans     

van Duijkeren E  van Mourik C  Broekhuizen M  Leuven M  Gaastra W  Houwers D 《Veterinary microbiology》2006,118(1-2):148-150

Capnocytophaga canimorsus was cultured from an infected, dog-inflicted bite wound in a pet rabbit. The wound was treated successfully and the rabbit recovered. To our knowledge, this is the first report of a C. canimorsus infection in a species other than humans.  相似文献   

Vaccine use and disease prevalence in dogs and cats     

Horzinek MC 《Veterinary microbiology》2006,117(1):2-8

A yearly revaccination of adult pets against distemper, the adenoviral and parvoviral diseases is scientifically unwarranted, professionally obsolete and ethically questionable; other vaccinal antigens, however, may need yearly or even more frequent injections. Base immunisation is redefined: it is complete only after the multivalent booster in the second year of life. A yearly revaccination interview, not necessarily an injection, should become the new standard. This interview is a professional service that must be taught, expertly performed and invoiced. Adult animals should be "vaccinated to measure", taking age, breed, lifestyle, the epidemiologic situation, etc. into account. Post-vaccination serology should become a guide in revaccination decisions. For a solid herd immunity, more animals of the population must be vaccinated. The profession should issue regular updates of the 'code of vaccination practice'. To counteract vaccination antagonism, a concerted action of academia, the veterinary profession and industry is required.  相似文献   

Triterpene saponins from the roots of Medicago hybrida     

Bialy Z  Jurzysta M  Mella M  Tava A 《Journal of agricultural and food chemistry》2006,54(7):2520-2526

Fourteen triterpene saponins (1-14) have been isolated from the roots of Medicago hybrida and their structures elucidated by FAB-MS and NMR analysis. Two of them are new compounds and were identified as hederagenin 3-O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (7) and oleanolic acid 3-O-[beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl]-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranoside] (14). Seven saponins being mono- and bidesmosides of hederagenin (1, 5, 6, 9), one bidesmoside of bayogenin (2), and two bidesmosides of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid (11) and oleanolic acid (13) are known compounds but not previously reported as saponin constituents of Medicago, whereas five other saponins, being mono- and bidesmosides of medicagenic acid (3, 4, 8, 10, 12), and one monodesmoside of hederagenin (8) have been previously isolated from other Medicago species. The presence of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid might represent an interesting intermediate in the biosynthesis of these substances.  相似文献   

Geochemistry. How melted rock migrates     

Holness M 《Science (New York, N.Y.)》2006,314(5801):934-935

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Feline calicivirus infection. ABCD guidelines on prevention and management     

Alan D. Radford  Diane Addie  Sándor Belák  Corine Boucraut-Baralon  Herman Egberink  Tadeusz Frymus  Tim Gruffydd-Jones  Katrin Hartmann  Margaret J. Hosie  Albert Lloret  Hans Lutz  Fulvio Marsilio  Maria Grazia Pennisi  Etienne Thiry  Uwe Truyen  Marian C. Horzinek 《Journal of Feline Medicine and Surgery》2009,11(7):556-564

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Feline infectious peritonitis. ABCD guidelines on prevention and management     

Diane Addie  Sándor Belák  Corine Boucraut-Baralon  Herman Egberink  Tadeusz Frymus  Tim Gruffydd-Jones  Katrin Hartmann  Margaret J. Hosie  Albert Lloret  Hans Lutz  Fulvio Marsilio  Maria Grazia Pennisi  Alan D. Radford  Etienne Thiry  Uwe Truyen  Marian C. Horzinek 《Journal of Feline Medicine and Surgery》2009,11(7):594-604

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Effects of Nitrogen Fertilization on Yield and Yield Components of Tropical Maize Cultivars   总被引：2，自引：0，他引：2  

R. Thiraporn    G. Geisler  P. Stamp 《Journal of Agronomy and Crop Science》1987,159(1):9-14

Six tropical maize cultivars were grown in Thailand on a reddish brown latosol under three nitrogen regimes, 0, 40 and 80 kg N/ha. With regard to biomass and economic yield several "cultivar by N fertilization response types" were discriminated. The low fertilization type was represented by an early and a late maturing cultivar, both yielded comparatively well without additional N and responded little to N fertilization. An opaque 2 cultivar and a commercial hybrid belonged to the high fertilization type, they had a very low yield without N and needed high N fertilization to produce a high yield. The other genotypes were of an intermediate type with comparatively high yields without N, a considerable increase in yield at 40 kg N/ha and some increase from 40 to 80 kg N/ha. Genotypic variability for the harvest index was high but values were at the usual low level of tropical cultivars. High fertilization types reacted to an additional N supply with a marked increase in kernel number/plant and little increase in kernel weight. The early maturing low fertilization type reacted quite the opposite way. All other genotypes predominantly increased kernel number from 0 to 40 kg N/ha and kernel weight from 40 to 80 kg N/ha.  相似文献