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Sampling statistics were determined for larvae, pupae and adults of the chrysomelid Rhyparida nitida associated with sugarcane in Australia and for symptoms of their damage. Iwao's patchiness regression was inappropriate for modelling the mean–variance relationships of the insect counts. Taylor's power law was used to model these data and relationships were developed for counts of small, medium and large larvae, all larvae combined, pupae and adults. The mean–variance relationships of counts of live shoots and shoots killed by larvae of R. nitida were modelled using Iwao's patchiness regression; Taylor's power law was not appropriate to either data set. Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling of the different stages and live and dead shoots were also developed. Neither the ln(x + 1) transformation nor the Healy and Taylor transformation consistently standardised the mean–variance relationships of insect counts and the appropriate transformation should be selected on a case-by-case basis. Counts of both live and dead shoots were adequately transformed by the Iwao and Kuno transformation.  相似文献   
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ABSTRACT: Clinical practice guidelines are one of the foundations of efforts to improve health care. In 1999, we authored a paper about methods to develop guidelines. Since it was published, the methods of guideline development have progressed both in terms of methods and necessary procedures and the context for guideline development has changed with the emergence of guideline clearing houses and large scale guideline production organisations (such as the UK National Institute for Health and Clinical Excellence). It therefore seems timely to, in a series of three articles, update and extend our earlier paper. In this first paper we discuss: the target audience(s) for guidelines and their use of guidelines; identifying topics for guidelines; guideline group composition (including consumer involvement) and the processes by which guideline groups function and the important procedural issue of managing conflicts of interest in guideline development.  相似文献   
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Strains of Bacillus subtilis that were resistant to repression of pyrimidine nucleotide biosynthetic enzymes were selected by isolating spontaneous uracil-tolerant derivatives of a uracil-sensitive strain, which lacks arginine-repressible carbamyl phosphate synthetase. The relative content of all six enzymes of uridylic acid biosynthesis de novo in these strains was in a constant ratio over a 10-fold range of derepression, which indicates that synthesis of these enzymes is coordinately regulated.  相似文献   
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Activity of the enzyme choline acetyltransferase (CAT), which mediates the synthesis of the neurotransmitter, acetylcholine, was increased up to 20- fold in spinal cord (SC) cells grown in culture with muscle cells for 2 wk. This increase was directly related to the duration of co-culture as well as to the cell density of both the SC and muscle involved and was not affected by the presence of the acetylcholine receptor blocking agent, α-bungarotoxin. Glutamic acid decarboxylase (GAD) activity was often markedly decreased in SC-muscle cultures while the activities of acetylcholinesterase and several other enzymes were little changed. Increased CAT activity was also observed when SC cultures were maintained in medium which had been conditioned by muscle cells or by undifferentiated cells from embryonic muscle. Muscle-conditioned medium (CM) did not affect the activities of SC cell GAD or acetylcholinesterase. Dilution or concentration of the CM directly affected its ability to increase SC CAT activity , as did the duration and timing of exposure of the SC cells to the CM. The medium could be conditioned by muscle cells in the presence or absence of serum, and remained effective after dialysis or heating to 58 degrees C. Membrane filtration data were consistent with the conclusion that the active material(s) in CM had a molecular weight in excess of 50,000 daltons. We conclude that large molecular weight material that is released by muscle cells is capable of producing a specific increase in CAT activity of SC cells.  相似文献   
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A double injection of PGF2α at two different dosage levels, 5 mg and 10 mg, eleven days apart, were compared with a combination of MAP-sponges and 5 mg or 10 mg PGF2α.The combination of MAP-sponges plus 10 mg PGF2α gave the best syn=chronization results (93,4%), as well as the best conception rate (84,9%) when ewes were inseminated on a fixed time basis 68 and 80 hours after treatment.  相似文献   
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