Two-way choice test

Three- or two-sample choices work best. A predator odor can be juxtaposed to a nonpredator odor and a nonscented control, making for a three-way choice test. In a second version of the experiment, one can differentiate the predator odor by comparing odors of a ground and an arboreal predator. Finally, odors of a native (sympatric) predator can be compared with those of an exotic (allopatric) one (Miiller-Schwarze 1972). These test whether sulfur compounds common to many carnivores are alarming - as suggested by Nolte et al. (1994) - or whether more specific stimuli are at work. 

Two-way choice apparatus (T-maze) for testing mouse responses to odors of conspecifics... 

This exercise and the next both deal with scent communication in mice. We practice two techniques frequently used in the Animal Behavior laboratory In this first experiment, we test a mammal s response to conspecific odors in a two-way choice apparatus, also called a Y- or T-maze, an often used bioassay device. [In the following experiment (Chap. 21), we observe and quantify scent marking behavior in response to two different stimuli in an open field. ]... 

In the T-maze we can test the responses of a male or female to a urine mark of the opposite sex, or from dominant or subordinate individuals of the same sex, or some other difference of interest. Among the many studies using two-way choice apparatuses for mice, a good example is a paper by Krasnov and Khokhlova (1996) that deals with mice responding to odors of another rodent species. We will test responses of males and females to urine of the same and different sex in a two-way choice apparatus (T-Maze). 

Amphibians have been shown to discriminate the odor of their home pond from other mud or water odors (Forester and Wisnieski 1991 Grubb 1973, 1976 McGregor and Teska 1989 Ogurtsov and Bastakov 2001). In a two-way choice apparatus, an animal chooses between mud or water from the home pond and some control mud or water from a different source. This experiment tests the ability to home by chemical cues, one aspect of orientation in space use newts, frogs or toads, depending on animals available. 

In this experiment, we built an apparatus for a three-way choice test. The three treatments were male-conditioned water, female-conditioned water and control water. Each water treatment was conditioned by placing two reproductively mature frogs in 19 L of water for 24 hours. Control water was prepared at the same time and placed under the same conditions for 24 hours. 

The way to test this is to provide stable cues for oblique lines, which we did by providing cards which always had a distinctive red oblique line, present in all the cards and always in the same orientation. In some oblique-oblique discriminations (always successive ones) one of the choice obliques was parallel to the stable oblique line and in others neither was. When one of the oblique lines was parallel to the stable feature the children could make the successive discrimination between obliques perfectly well. When neither paralleled this framework feature they were in trouble again. In match-mismatch terms the easy discriminations were between match and mismatch signals and the difficult—usually impossible—ones between two mismatch signals. 

Keswick et al. [72] compared two exaggerated use tests (the forearm wash test and the flex wash test) with a test under normal use conditions, by using soap and syndet bars as test material. The authors showed that both methodologies yielded similar mildness levels when syndet bars were used but not when soap bars were used. In this latter case, the way the products are applied to skin seems to play a major role in the level of observed skin irritation. Similar differences in the levels of sensitivity between two arm wash procedures were related by Nicoll et al. [156]. These examples demonstrate that the choice of a test procedure must always be clearly explained and justified in the protocol. 

In the identification of esters we are faced with problems of identifying their acid and alcoholic components. In principle, we can solve this problem in two ways—either by identifying the alcoholic component in one part of the sample and the acid in the other part, or by carrying out a hydrolysis of the ester and isolation of both reaction products, followed by their identification. The choice of method depends on the nature of the ester preliminary physical tests can help in making the proper choice (melting point, boiling point, refractive index). 

Most tests will be made on standard test pieces which may be pieces cut from a component or a sheet, or they may have been moulded separately from the same material. Where test pieces or sheet are produced for the trials it is important that they are produced in as near as possible the same way as the product and that the processing conditions are recorded. Different results can be expected from compression and injection moulding or from extrusion (where a choice is possible). Directional properties can result from the conditions of flowing and cooling in a mould. For example, in a study at ERA, the creep strain of unfilled HDPE, either individually moulded or cut from square plaques, varies by up to a factor of two depending on the orientation of flow [40]. This difference becomes even more marked with short fibre reinforcement. 

Near the end of this study guide you will find additional sections that may help you to study for the final examination in the course. The SUMMARY OF SYNTHETIC METHODS lists the important ways to synthesize each class of compounds discussed in the text. It is followed by the SUMMARY OF REACTION MECHANISMS. Both of these sections have references to appropriate portions of the text, in case you feel that further review is necessary. Finally, you will find two lists of sample test questions. The first deals with synthesis, and the second is a list of multiple-choice questions. Both of these sets should help you prepare for examinations. 

Clearness and transparency with respect to the choice of models, methods, assumptions, distributions and parameters are two prerequisites for trust and confidence openness about uncertainties is another. Exposure assessment as an applied science should follow the main scientific desiderata empirical testing, documentation and reproducibility of results, explicit reporting of uncertainty, peer review and an open debate about underlying theories and models. This way, the main attributes for characterizing uncertainty discussed in the last chapter, the appraisal of the knowledge base and the subjectivity of choices, are clarified. 

The experimental support for the verification of the hypothesis will require a long time. For testing it, another way is to suppose that it is true and examine its implications [12], Three points were considered. If it is true (i) for given experimental conditions, the use of diamines, too large for ensuring the three dimensional connection of the SBU, must lead to lamellar solids, the sheets being built up from the connection of the expected SBU. This was realized with ULM-8 [62] (ii) with a proper choice of the geometry, the acidobasic characteristics and the reactivity of an amine, it may be possible to synthesize tailor-made solids. The first success concerned ULM-16 [24] which used two amines, one for structure... 

The results of endotoxin tests for in-process solutions, bulk materials, and finished parenteral products should be reported in the same units as those assigned to the product. Two factors determine the sensitivity of a BET. For infusion solutions and device extracts, the gel-clot sensitivity or the lowest point on the standard curve (lambda for kinetic LAL) and the amount of dilution determine test sensitivity.For products that have an endotoxin limit in EU/mg, the choice of lambda and the concentration of the test material determine sensitivity. The formula for product-specific sensitivity (PSS) is a convenient way to calculate the sensitivity of a BET for this type of product, where ... 

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