Instance description

There are two basic kinds of epidemiological studies, descriptive and analytical. The goal of the first is to describe the occurrence of disease in populations. Analytical studies identify and explain the cause of the disease. For instance, descriptive epidemiology may identify a new disease such as AIDS. Interpretation of descriptive results leads to analytical studies that examine the disease in more detail. Since epidemiology is the study of disease in populations, the proportion of affected individuals in a population is of basic importance. However, the epidemic pattern has varied from country to country. In the United States and the United Kingdom, 65% and 85%, respectively, of AIDS cases have... 

A teacher trainer, instructor) chooses instance descriptions (examples) of instances of the intended concept, and presents them to a learner. There are different ways of presenting examples all-at-once and chunk-wise (for instance, one-by-one). 

An even coarser description is attempted in Ginzburg-Landau-type models. These continuum models describe the system configuration in temis of one or several, continuous order parameter fields. These fields are thought to describe the spatial variation of the composition. Similar to spin models, the amphiphilic properties are incorporated into the Flamiltonian by construction. The Flamiltonians are motivated by fiindamental synnnetry and stability criteria and offer a unified view on the general features of self-assembly. The universal, generic behaviour—tlie possible morphologies and effects of fluctuations, for instance—rather than the description of a specific material is the subject of these models. 

Even when well defined model systems are used, colloids are ratlier complex, when compared witli pure molecular compounds, for instance. As a result, one often has to resort to a wide range of characterization teclmiques to obtain a sufficiently comprehensive description of a sample being studied. This section lists some of tire most common teclmiques used for studying colloidal suspensions. Some of tliese teclmiques are discussed in detail elsewhere in tliis volume and will only be mentioned in passing. A few teclmiques tliat are relevant more specifically for colloids are introduced very briefly here, and a few advanced teclmiques are highlighted. 

Contrary to what appears at a first sight, the integral relations in Eqs. (9) and (10) are not based on causality. However, they can be related to another principle [39]. This approach of expressing a general principle by mathematical formulas can be traced to von Neumann [242] and leads in the present instance to an equation of restriction, to be derived below. According to von Neumann complete description of physical systems must contain ... 

What-If Analysis. The what-if analysis is simply a brainstorming technique that asks a variety of questions related to situations that can occur. For instance, in regards to a pump, the question What if the pump stops mnning might be asked. An analysis of this situation then follows. The answer should provide a description of the resulting consequence. Recommendations then foUow, if required, on the measures taken to prevent an accident. 

Polymeric Ma.teria.Is, The single-ply membranes are made from a wide variety of polymers. The following is a brief description of those polymers and their characteristics. There are three thermosetting-type elastomeric membranes as of this writing (1996) neoprene, CSPE, and EPDM. Neoprene is stiU used where oil resistance is needed. Eor instance. Hydrotech uses neoprene flashings, the base of which is hot-set in mbberized asphalt (see ElASTOL RS, SYNTHETIC-POLYCm.OROPRENE). 

Chemically related database searches can be used to estabhsh concepts and patentable ideas. For instance, searches have identified researchers using particular monomers in a potentially patentable latex formulation found precedents for a polymeric emulsifier summarized pubHcations of people being considered as consultants, expert witnesses, employees or speakers to an industrial group and provided market description information for a new pigment manufacturing firm to identify target markets. 

In the following sections, an overview of some of the key developments in the discovery of potent influenza vims sialidase inhibitors is provided. In the first instance, the discovery of the influenza vims sialidase inhibitors that have become the current first-hne-of-defence anti-influenza dmgs will be described, followed by a description of some of the other important sialidase inhibitor developments to date. 

Rousseeuw [4]. Massart and Kaufman [5] and Bratchell [6] wrote specifically for chemometricians. Massart and Kaufman s book contains many examples, relevant to chemometrics, including the meteorite example [7]. More recent examples concern classification, for instance according to structural descriptions for toxicity testing [8] or in connection with combinatorial chemistry [9], according to chemical... 

A more recently introduced technique, at least in the field of chemometrics, is the use of neural networks. The methodology will be described in detail in Chapter 44. In this chapter, we will only give a short and very introductory description to be able to contrast the technique with the others described earlier. A typical artificial neuron is shown in Fig. 33.19. The isolated neuron of this figure performs a two-stage process to transform a set of inputs in a response or output. In a pattern recognition context, these inputs would be the values for the variables (in this example, limited to only 2, X and x- and the response would be a class variable, for instance y = 1 for class K and y = 0 for class L. 

As has been described in Ref. 70, this approach can reasonably account for membrane electroporation, reversible and irreversible. On the other hand, a theory of the processes leading to formation of the initial (hydrophobic) pores has not yet been developed. Existing approaches to the description of the probability of pore formation, in addition to the barrier parameters F, y, and some others (accounting, e.g., for the possible dependence of r on r), also involve parameters such as the diffusion constant in r-space, Dp, or the attempt rate density, Vq. These parameters are hard to establish from first principles. For instance, the rate of critical pore appearance, v, is described in Ref. 75 through an Arrhenius equation ... 

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