Temporal Aspects

The temporal pattern of sampling is of great importance if the environment to be sampled shows changes over time, e.g., river systems within minutes or hours, or lakes within days 

Initial considerations for planning and carrying out sampling procedures. 

A single sample gives only a snapshot of the situation, and the power and reliability of the results are normally low and depend strongly on the backgroimd data and additional information available. However, the advantage is that often the equipment necessary for this t5q)e of sampling is very simple and inexpensive. 

In addition to single and discontinuous sampling, continuous sampling and determination of analytical values is desirable in some cases. An example is the quality control for a 

---

There have also been attempts to describe the temporal aspects of perception from first principles, the model including the effects of adaptation and integration of perceived stimuli. The parameters in the specific analytical model derived were estimated using non-linear regression [14]. Another recent development is to describe each individual TI-curve,/j(r), i = 1, 2,..., n, as derived from a prototype curve, S t). Each individual Tl-curve can be obtained from the prototype curve by shrinking or stretching the (horizontal) time axis and the (vertical) intensity axis, i.e. fff) = a, 5(b, t). The least squares fit is found in an iterative procedure, alternately adapting the parameter sets (a, Zi, for 1=1,2,..., n and the shape of the prototype curve [15],... 

Has no action when binding on its own to the receptor but only modulates the actions of the naturally occurring hormone or neurotransmitter when it is released. Therefore, the temporal aspects of the natural signaling mechanism are retained and desensitization is minimized. 

Lundin R.E., Wagoner J.K. and Archer V.E., 1971, Radon Daughter Exposure and REspiratory Cancer-Quantitive and Temporal Aspects,... 

Lundin,F.E., Wagoner,J.K. and V.E. Archer, Radon Daughter Exposure and Respiratory Cancer, Quantitative and Temporal Aspects, Nat. Inst. Occup. Safety and Health/Nat. Inst. Env.Sciences, Joint Monograph No.1, US Dept, of Health, Education and Welfare, Public Health Service (NTIS, No. PB 204871), Washington, D.C. (1971). 

The usefulness of an in vitro/in vivo correlation (IVIVC) during product development depends on how accurately it can predict resultant plasma concentrations from any given set of in vitro data. This, in turn, is heavily dependent on the design of the in vitro and in vivo studies used to develop and validate the IVIVC. The design of in vitro studies is covered in another chapter, but the temporal aspect of the in vitro study as it relates to the IVIVC will be covered here. The major emphasis of this chapter, however, will be the design of the in vivo study. 

Lundin F et al Radon Daughter Exposure and Respiratory Cancer Quantitative and Temporal Aspects. Report from the Epidemiological Study of U. S. Uranium Miners. Joint Monograph No. 1, NIOSH and NIEHS, 1971... 

Eyes, face Retraction of upper lid with wide stare periorbital edema exophthalmos diplopia (Graves disease) Drooping of eyelids periorbital edema loss of temporal aspects of eyebrows puffy, nonpitting facies large tongue... 

It was noted in Section I that Sidgwick (1893) and others have drawn attention to the temporal aspect of the multiplicity of the self. It may therefore be of interest to consider whether a multi-aspect view of the individual decision-taker might be able to capture, at least in part, both the Benthamite view that normal rational agents do in fact exhibit pure time preference and the Ramsey-Harrod view that it is irrational to do so. We might, for example, present an analysis of the familiar choice of consumption stream problem, in which u, ) represents the assessment of the whole consumption stream from the standpoint of the agent as he will be in period i the various u ( ) will... 

All these examples focus on the temporal aspect of nectar induction. In addition, extrafloral nectaries are also especially suited for the study of spatial dynamics following induction. This aspect can be easily assessed because of the discrete distribution of nectaries, the possibility of non-destructive sampling, as well as the ease of nectar collection. With respect to the spatial pattern of induction, Wackers et al. (2001) showed that the impact of herbivory on extrafloral nectar induction is primarily localized (i.e., restricted to the damaged leaf). This local increase in nectar production can help in actively guiding ants to the site of attack. In addition, a weaker systemic response was found. This systemic induction was restricted to the younger leaves. 

Stieger, C., Hegglin, D., Schwarzenbach, G., Mathis, A. and Deplazes, P. (2002) Spatial and temporal aspects of urban transmission of Echinococcus multilocularis. Parasitology 124, 631-40. 

I I Warkentin TE, Kelton JG. Temporal aspects of heparin-induced thrombocytopenia. N Engl J Med 2001 344 1286-1292. 

This chapter lays down the conceptual framework for understanding the quantitative and temporal aspects of drug-drug interactions, hereafter called drug interactions for simplicity. Emphasis is placed primarily on the pharmacokinetic aspects, partly because pharmacokinetic interactions are the most common cause of undesirable and, to date, unpredictable interactions and also because most of this book is devoted almost exclusively to this aspect and indeed to one of its major components, drug metabolism. Some pharmacodynamic aspects are also covered, however, for there are many similarities between pharmacokinetic and pharmacodynamic interactions at the molecular level and because ultimately one has to place a pharmacokinetic interaction into a pharmacodynamic perspective to appreciate the likely therapeutic impact (1-5). 

Landscape ecotoxicology This section describes current developments and extrapolation tools used in landscape ecotoxicology. Because ecological effect assessment of chemicals at the landscape level requires the integration of both spatial and temporal aspects, this section in particular builds further on the data presented in Chapter 6 on temporal extrapolation in ecological effect assessment of chemicals. 

Do we have data pertinent to the exposure situation to be considered, or are there specific temporal aspects in the exposure regime (intermittent... 

Pierano WB, Mattie D, Smith P (1995) Proceedings of the Conference on Temporal Aspects in Risk Assessment for Noncancer Endpoints. Inhal Toxicol, 7 837-1029. 

These models assume that oral drug absorption takes place under equilibrium conditions. Spatial or temporal aspects of the drug dissolution, transit and uptake and the relevant physiological processes in the gastrointestinal tract are not taken into account. Only drug-related properties are considered as the key parameters controlling the absorption process. 

Neglecting dynamic models in pharmacodynamics [430] is perhaps due to the fact in that instant equilibrium relationships between concentration and effect appear to occur for most drugs. For some drugs, such as cytotoxic agents, this delay is often extremely long, and attempts to model it are seldom made. One can describe these relationships as time-dissociated or nondynamic because the temporal aspects of the effect are not linked to the time-concentration profile. 

This area of study interfaces with two of the intellectual frontiers in chemistry, namely chemical kinetics and chemical theory. Chemical reactions are studied on ever-decreasing time scales, and further advances in the understanding of chemical kinetics are likely to be made. Advanced chemical research helps to discern the most likely pathways for energy movement within molecules and the energy distribution among reaction products, thereby clarifying factors that govern temporal aspects of chemical... 

An adequate assessment of exposure to mixtures may require development of improved tools for measurement or detection of chemicals, but also for assessing temporal aspects of exposure. 

---