Water,society and landscape ecology   总被引：2，自引：1，他引：1  

Robert J. Naiman 《Landscape Ecology》1996,11(4):193-196

  相似文献   

The effects of diflubenzuron on the growth of insect cuticle     

Robert F. Ker 《Pest management science》1978,9(3):259-265

Cuticle consists of chitin microfibrils embedded in a matrix composed largely of hydrated proteins. The effect of diflubenzuron, an inhibitor of chitin synthetase, on the deposition of both these components is reviewed. The polymerisation reaction is but one step in the pathway leading to chitin microfibrils. Possibly interactions to other steps in the pathway serve to enhance the consequences of the inhibition. Such enhancement could help to explain the abrupt changes in the rate of chitin synthesis that can be observed as diflubenzuron is cleared from epidermal cells. Cuticle proteins differ widely in their ability to form a stable layer when chitin is largely absent. In the most stable regions, diflubenzuron has no effect on the amount or nature of the proteins deposited. In contrast, there are many regions where the deposition of solid cuticle is stopped, presumably because the proteins involved cannot form a coherent layer. Intermediate degrees of stability are found. There is an association between the regions of stability and those of high sclerotisation; though sclerotisation often takes place long after deposition. Even when the protein layer is fairly stable it may not be deposited in a regular manner. This statement is illustrated by electron micrographs of cuticle from the hind tibiae of adult locusts. These micrographs also show that diflubenzuron can affect epidermal cells. In normal cells the plaques are in contact with the newly secreted cuticle; they are still present but this contact is not maintained after treatment with diflubenzuron.  相似文献   

Residual fumigant effect of 1,2-dibromoethane (EDB) in fumigations against queensland fruit fly,Dacus tryoni (froggatt), infestations in mangoes     

Gordon Swaine  Robert J. Corcoran  Marguerite A. Davey 《Pest management science》1976,7(5):465-470

A residual fumigant effect is demonstrated for fruit held 1 to 3 days within its cardboard carton after fumigation with 1,2-dibromoethane (EDB). This residual fumigant effect reduces significantly the dosage required for a specified level of control when compared with that required for fruit removed from the carton immediately after airing when fumigation is completed. The effect is due to the slow release of gas sorbed during fumigation and to the slow dispersion of this gas from the carton.  相似文献   

Metaphors,misuse, and misconceptions     

Maslansky R 《Science (New York, N.Y.)》2003,301(5639):1479-82; author reply 1479-82

  相似文献   

American Chemical Society meeting. Molecular scaffolding helps raise a crop of neurons     

Service RF 《Science (New York, N.Y.)》2003,302(5642):46-47

  相似文献   

Astronomy. Smashup sends alien stars streaming near the sun     

Irion R 《Science (New York, N.Y.)》2003,302(5642):32

  相似文献   

Physics. Laser labs race for the petawatt     

Service RF 《Science (New York, N.Y.)》2003,301(5630):154-156

  相似文献   

West Nile Virus: emerging threat to public health and animal health     

McLean RG 《Journal of veterinary medical education》2003,30(2):143-144

  相似文献   

Development of the angle of the anterior chamber in human and vertebrate animals' eyes     

Barishak YR 《Veterinary ophthalmology》2003,6(1):1-2

  相似文献   

Effect of furosemide on urine specific gravity and osmolality in thoroughbred racehorses     

Bosken JM  Tobin T  Mundy GD  Fisher M  Gantz MG  Banks RO 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(3):292-298

Postrace urine samples from thoroughbred horses were examined to compare osmolality and specific gravity between horses treated with furosemide and those not treated. Samples were assigned to groups in relation to reported medication (furosemide) status, race finish position, and distance of race. Urine osmolality was significantly (P <.05) lower in samples from horses treated with furosemide when compared with untreated horses. Specific gravity determinations are less precise at measuring urine osmolality at lower levels (1.01 g/ml or less). The measurement of osmolality is a superior method for determining the urine solute concentration and facilitating the regulation of furosemide.  相似文献