Plants function

Water chemistry is important to the safe and reflable operation of a nuclear power plant. Improper conditions can lead to equipment and material failures which ia turn can lead to lengthy unscheduled shutdown periods for maintenance (qv) and repair operations. Water chemistry can also have an impact on the radiation levels duriag both power operations and shutdown periods. These affect the abiUty of personnel to perform plant functions. 

It is often assumed that TA cannot be applied during design, because until the plant has been fabricated the tasks to be performed by workers cannot be defined in sufficient detail. In fact, many TA techniques can be used to specify the nature of the tasks to achieve the required process plant functions, even before the exact configuration of the system has been finalized. This point will be elaborated later in the context of hierarchical task analysis. 

P, the seven-carbon sugar serving as the transketolase substrate. Likewise, phosphoribulose kinase carries out the unique plant function of providing RuBP from Ru-5-P (reaction 15). The net conversion accounts for the fixation of six equivalents of carbon dioxide into one hexose at the expense of 18 ATP and 12 NADPH. 

The logistics of erecting new buildings and rearranging the plant with minimum disturbance to the plant functions ... 

Combustion controls such as oxygen trim help to maintain optimum operating conditions, especially on gaseous fuels. Instrumentation can give continuous visual and recorded information of selected boiler and plant functions. To be effective, it must be maintained and the data assessed and any required action taken before the information is stored. 

Computer monitoring and control systems have recently been introduced. These are designed to operate in place of conventional instrumentation. Using intelligent interface outstations connected to a desktop computer, many plant functions may be programed into the computer and controlled centrally. 

Hi) Poly amines. In many respects the role of poly amines in plant functioning is still mysterious after many years work. They are almost certainly involved in the control of growth and development through their interactions with nucleic acids and membranes (Smith, 1985). There is increasing circumstantial evidence for their involvement, especially of putrescine, in plant responses to a wide range of stresses including pH, Mg deficiency, osmotic shock, cold, SO2 pollution, and cadmium and ammonium toxicity (Smith, 1985). It remains to be determined, however, how, and indeed whether, putrescine accumulation in response to these diverse stresses is beneficial. 

Drought is perhaps one of the most complex examples to choose but it illustrates well the possibilities of, and pitfalls to, progress. Drought affects almost every facet of plant function and we are faced with the paradox that yield and evapotranspiration are intimately linked. In general, increases in yield when water supply is limiting are likely to result from characteristics which increase the available water supply, increase water use efficiency or increase biomass allocation to the economically useful plant parts (Pass-ioura, 1986). Additionally, features which maintain cell viability and protect metabolism in water-stressed tissue and allow rapid recovery after dry periods will contribute yield under some circumstances. 

Recall Eq. (10-46) that Hj and H2 are defined entirely by the four plant functions Gy. This is another example of model-based control. With the definitions of Hj and H2 given in (10-46), the calculations are best performed with a computer. 

Terrestrial plants function as conduits for the transport of elemental mercury from the geosphere to the atmosphere (Leonard et al. 1998a). Estimated mercury emissions from plants in the Carson River Drainage Basin of Nevada over the growing season (0.5 mg Hg/m2) add to the soil mercury... 

BIOINFORMATICS AND COMPUTATIONAL BIOLOGY FOR PLANT FUNCTIONAL GENOMICS... 

SOMERVILLE, C., SOMERVILLE, S., Plant functional genomics, Science, 1999, 285, 380-383. 

FIEHN, O., KOPKA, J., DORMANN, P., ALTMANN, T., TRETHEWEY, R.N., WILLMITZER, L., Metabolite profiling for plant functional genomics, Nature Biotechnol., 2000,18, 1157-1161. 

Ammonia oxidation process, of nitric acid production, 17 170-171 Ammonia oxidation reactions, 10 98 Ammonia plant functions of, 17 293 as reliability example, 26 994-997... 

Plant water status is affected by environmental pollution and consequently influences plant function at every level of biological organisation. It can be characterized by measurements of the relative water content (RWC), the water deficit, the water potential ( P ) and the osmotic potential ( Fq), along with transpiration rate and stomatal resistance. Since for the latter four parameters, tissue samples are removed from the plant, they are usually determined in the end of an experiment. If several sampling times are needed, then additional plants/replicates must be included. 

A characteristic feature of allelopathy is that the inhibitory effects of allelopathic compounds are concentration dependent. Dose-response curves with known compounds show an inhibition threshold. Below this level either no measurable effect occurs, or stimulation may result. Although the concentration of a compound required to exceed the inhibition threshold varies extensively according to different sensitivities among species and also among phases of the growth cycle for higher plants, the concept of an inhibition threshold seems consistent. Thus, it is reasonable to evaluate how, and if, a subthreshold concentration of an allelochemical may contribute to allelopathic interference. Also in need of evaluation is how environmental conditions may influence the deleterious action of an allelochemical and the concentration required for an effect. Such interactions are especially pertinent for those environmental situations that place some degree of stress on plant functions. 

Thus, the potential Impact of an allelochemical on plant growth should be evaluated with regard to both the presence of associated allelopathic compounds and the influence of other chemical and physical conditions in the environment. Certainly allelochemical action is not an isolated event, and from the standpoint of plant functions, the controversy between competitive and allelochemical Interference loses some of its significance. Allelochemical action needs to be regarded with a holistic view where one stress may reinforce, or magnify, another. From this perspective, inhibition of plant growth is not so much a matter of which factor is most detrimental instead it is determined by the interaction of multiple stresses. 

The Interactions between availability of resources, carbon gaining capacity, and the allocation of carbon to plant functions, Including chemical defense, will obviously differ among environments. We examine a particular system, the temperate deciduous forest, to Illustrate the nature of the constraints on chemical defenses Imposed by limitations on carbon gain. 

Koes RE, Quattrocchio F, Mol JNM. 1994. The flavonoid biosynthetic pathway in plants Function and evolution. BioEssays 16 123-132. 

Figure 1 Main piloting options. (Top) Separate pilot plant functions—engineering concept. (Bottom) Joint pilot operation.

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