Patchy distribution

Fig. 6.1 Different plant strategies for dealing with patchy distribution of P in soil (a) initial situation random distribution of roots, (b) increased root production, (c) production of cluster roots in high-P environments, (d) production of cluster roots at random. For discussion, see text...

Macrozooplankton >2000 Euphausiids, salps, pteropods Produce large fecal pellets, which sink much faster than those of mesozoopiankton Graze across a wide spectrum of sizes. Can achieve very high biomass iocaiiy, but tend to have a patchy distribution... 

Tn applying pesticide sprays, the first problem is that of distributing a small quantity of active material over a large target area. The uniformity and extent of the distribution required depend on the type of pest to be controlled and the mode of action of the toxicant a patchy distribution may be satisfactory to control mobile insects or to apply systemic pesticides to foliage, whereas for static pests and contact pesticides, a more uniform spray deposit may be required. The degree of distribution attained depends on ... 

Keywords chemotaxonomy patchy distribution biosynthesis genes horizontal gene transfer endophytes evolution tryptophan decarboxylase tyrosine decarboxylase phenylalanine ammonia-lyase chalcone synthase strictosidine synthase berberine bridge enzyme codeine reductase... 

One of the main questions discussed in this chapter is about the origin and evolution of plant secondary metabolism. We have started with the observation that some SM (such as phenolics and terpenoids) are produced by nearly all vascular plants, whereas others, especially those with alkaloids, cardiac glycosides, anthraquinones, etc., show a more restricted but usually patchy distribution. 

The patchy distribution could be due to simple convergence, which is certainly the case in several instances. It could also be due to a wider distribution of SM pathway genes in the plant kingdom, which are silent or... 

The sea water in this area is enriched in some metals compared with the world average sea water. Especially, iron and man nese are present in higher quantities, the iron quantity is several times larger than the quantity of manganese. The patchy distribution of this enrichment seems to be caused by the colloidal stage of iron and manganese hydroxides ... 

In addition to greatly altering P distribution within the pasture area due to the patchy distribution of excretion, cattle can also indirectly enhance the potential of P movement in the landscape. This is because cattle transit within the pasture area can create trails which are channels for runoff, and overgrazing and trampling may result in open areas that facilitate losses through runoff of particulate and dissolved P and erosion of surface soil and plant material. Since most of the excreted P is in the feces... 

Environmental heterogeneity and the patchy distribution of organisms in space can also be considered in evaluating the risks to populations. 

Schulz, S., Breuel, G., Lass, H. U., Matthaus, W, Nehring, D., Postel, L., 1989. The patchy distribution of oceanological parameters during the spring bloom in the Baltic Sea. In Ryland, J. S., Tyler P. A. (eds.). Reproduction, Genetics and Distributions of Marine Organisms. Olsen Olsen,Fredens-borg, pp. 451-458. 

FIGURE 16.3 Occurrence of Fucus vesiculosus in the Baltic Sea—changes observed in the mid 1980s compared to historical data (data from Wachenfeldt et al. (1986)). 1, no changes observed 2, moderate decrease 3, decrease, patchy distribution 4, strong decrease or total loss broken line, limit of distribution. 

The diagnosis of HP infection can be made using endoscopic or nonendoscopic tests (Table 33-6). The tests that require upper endoscopy are more expensive, uncomfortable, and require a mucosal biopsy for histology, culture, or detection of urease activity. Recommendations to maximize the diagnostic yield include taking at least three tissue samples from specific areas of the stomach, as patchy distribution of HP infection can lead to false-negative results. Because certain medications may decrease the sensitivity of these tests, antibiotics and bismuth salts should be withheld for 4 weeks and PPIs for 1 to 2 weeks prior to endoscopic testing. 

Analysis of polychlorinated biphenyls. We have undertaken analysis of PCBs along the shores of Lake Victoria. Sampling stations were chosen to capture upstream activities, run offs and sediments brought along the rivers as souree of PCBs. Surface sediments from three different composite sites were sampled with a stainless steel shovel and combined to one pole sediment sample because PCBs in sediments can show a patchy distribution. Sediment samples were wrapped with aluminum foil, labeled and stored at -25°C. 

Salivary gland ductal carcinomas are commonly positive in a patchy distribution for both PSA and PAP and immunostain strongly for androgen receptors (AR)." ° Close clinical correlation with a PSA+, PAP+, AR+ profile becomes mandatory. 

Alpha-fetoprotein is present in most yolk sac tumors in patchy distribution, but only focally in some cases of embryonal carcinoma.430.455,462-464 Hepatoid differentiation in germ cell tumors, especially with yolk sac tumors, typically immunostains with alpha-fetoprotein and does not show the immunoprohle of true hepato-cytic differentiation, that is, the biliary pattern of immu-nostaining with polyclonal CEA. 

CYTOKERATIN 7 CK7 expression is an important marker of committed gastric epithelial cells and gastric adenocarcinoma. Approximately 50% of gastric adenocarcinomas are strongly positive in a diffuse or patchy distribution 30% have rare clusters of strongly reactive cells, and 20% are weakly positive or negative (Fig. 14.9).11 -120,122-125... 

Uterine leiomyosarcomas frequently express cytokeratins in a patchy distribution. 

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