Dichotomous relations

The relative judgements that are put together in these spatial inferences are either dichotomous or trichotomous. In the examples that we have given, they are dichotomous either two lines are parallel or they are not, either two dots are in line or they are not. In other cases there are three possible relations for example nearer than, at the same distance as, further away than. Inferences based on dichotomous relations therefore can pick up regularities when either one or two percepts produce a match signal (i.e. are the same along a spatial dimension as the stable feature)... 

Insomnia complaints are common in the general population and can be dichotomized into problems of delayed sleep onset and those related to sleep maintenance. Increasing attention is being focused on the adverse daytime effects of insomnia. Sleep disturbances become more common with increased age and are more prevalent in women. Sleep complaints arise from very diverse etiologies which prominently include concomitant primary... 

In several studies on the antiviral effects of NO on HIV-1 infection, the proviral or antiviral effects of NO seem to be strictly related to the active production of NO during HIV-1 infection. The universal speculative interpretation of the dichotomous effect of NO is that overproduction of this substance, especially in the primary infection and in late stages of the disease, leads to active viral replication with consequent harmful effects on the course of the disease. Conversely, low production of NO may cause a reduction in or inhibition of HIV-1 replication, especially during the symptomless stage of the disease, or during treatment with highly active combined antiretroviral drugs. 

All of the mathematical models that relate dose to response rate are either dichotomous response models or time-to-response models (23). Dichotomous response models are concerned with whether or not a particular response (tumor) is present by a particular time (e.g., the animal s normal lifetime). In time-to-response models, the relationship between initiation of exposure and the actual occurrence of the response is determined for each animal. 

Another important feature of mathematical modeling techniques is the nature of the response data that they are capable of handling. Some methods are designed to work with data that are measured on a nominal or ordinal scale this means the results are divided into two or more classes that may bear some relation to one another. Male and female, dead and alive, and aromatic and nonaromatic, are all classifications (dichotomous in this case) based on a nominal scale. Toxic, slightly toxic, and non-toxic are classifications based on an ordinal scale since they can be written as toxic > slightly toxic > non-toxic. The rest of this section is divided into three parts methods that deal with classified responses, methods that handle continuous data, and artificial neural networks that can be used for both. 

This is a crucial aspect subtly related to the main goal of this review. In Section VIII we have seen that the non-Poisson condition violates the DF property. This is a prescription for constructing the correlation functions of the dichotomous fluctuation E,(f), serving the purpose of defining the corresponding diffusion process. In Section XII we have illustrated the problems associated to the derivation of these higher-order correlation functions from a density perspective. It is worth while to address this issue again. 

It has been argued that a failure to find enduring behavioral effects of prenatal cocaine exposure in some studies may have been related to the use of broad, relatively insensitive measures (357,358). Furthermore, to judge the effect of prenatal cocaine exposure based on a dichotomous variable (yes/no) may not be an appropriate study design (359,360). 

This enumeration suggests some preliminary comments. First, we are left in the dark about the class structure of the Asiatic mode of production. Secondly, each of the other modes of production is said to include three or more classes, thus excluding any kind of dichotomous class structure, such as the haves vs. the have-nots. Next, the category of freeman is an incongruous element, since his relations to the factors of production is not fully specified. The free man owns his labour-power, he may or may not own the means of production and the labour-power of others. Finally, patricians and plebeians would seem to form status groups rather than classes. I return to this problem in 6.1.3. It suggests that it may not be possible to construct a Marxist notion of class that is fully consistent with both Marx s actual usage and his theoretical purposes. 

Relation of number of couplets (consisting of two leads) vs. number of taxa keyed out In a dichotomous key which divides the group into equal (50%—50%) blocks the equation isi y 2 to the power x or x 2log y (x number couplets y number taxa). Thus for 8 taxa one has to pass 3 couplets, but for 32 taxa only 51 (In fact 6 questions reap. 10, as both leads need to be read carefully ) The total... 

There are basically two types of mathematical models commonly used to represent dose response relationships. One type which is referred to as a dichotomous or yes-no modelis concerned with whether or not a specific response, such as cancer, has occurred with increased incidence in the treated pwpulation. The second type, which is a time-to-response model, attempts to relate dose levels to the time of appearance of the measured effect. 

A measure of the extent of loss (consequence). Example, continued The consequence in the LTI-rate is measured on a dichotomous scale related to whether the accident has resulted in lost time or not. 

Fig. 10 illustrates the results of a multifactor cross-classification analysis from the same study, for white men age 45-64, with five risk factors dichotomized (including plasma glucose 1-hour post-50-gm-oral-load). With exclusion from the analysis of hypertensives on treatment and diabetics on treatment, glucose and rate of major ECG abnormalities were significantly related in two cases (noted by asterisks), but not in two others, and in only one of four comparisons for white women age 45-64 (Fig. 11). Similar inconsistent results were obtained with the more elegant multiple logistic regression technique (Fig. 12) where in only two of four analyses (after exclusion of hypertensives on treatment) were the values greater than 2.00 obtained indicating a significant relationship between post-load plasma glucose and major ECG abnormalities.

The Cincinnati study measured alcohol and tobacco exposure by a dichotomous score that was positive if the mother reported use of alcohol, tobacco, or both. The relationship of birth weight to use of tobacco has been fairly well established, and reduced birth weight has been related to foetal alcohol exposure (Abel, 1983). We considered the possibility that this simple... 

The present study now considers whether gestational age (or the dichotomous variable, preterm delivery) is related to lead level. This, too, is an important outcome measure and is a covariate in some studies of later... 

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