Feasibility, researchable questions

As mentioned above, the appropriate metric depends on the research question as well as on the methodology used in the experiment. Considering, for example, a hardware test with dummies, the metric has to be based on the readings of the dummy. Commonly used physical measurements such as the Head Injury Criterion (HIC) can then be translated into an injury probability, which is a well-known procedure [29]. A comparable approach is feasible using simulation. In a finite-element simulation or a kinematic simulation of collisions, a human model, e.g., the Total Human Model for Safety (THUMS), can be used [30]. 

The field of modified electrodes spans a wide area of novel and promising research. The work dted in this article covers fundamental experimental aspects of electrochemistry such as the rate of electron transfer reactions and charge propagation within threedimensional arrays of redox centers and the distances over which electrons can be transferred in outer sphere redox reactions. Questions of polymer chemistry such as the study of permeability of membranes and the diffusion of ions and neutrals in solvent swollen polymers are accessible by new experimental techniques. There is hope of new solutions of macroscopic as well as microscopic electrochemical phenomena the selective and kinetically facile production of substances at square meters of modified electrodes and the detection of trace levels of substances in wastes or in biological material. Technical applications of electronic devices based on molecular chemistry, even those that mimic biological systems of impulse transmission appear feasible and the construction of organic polymer batteries and color displays is close to industrial use. 

For nonequilibrium statistical mechanics, the present development of a phase space probability distribution that properly accounts for exchange with a reservoir, thermal or otherwise, is a significant advance. In the linear limit the probability distribution yielded the Green-Kubo theory. From the computational point of view, the nonequilibrium phase space probability distribution provided the basis for the first nonequilibrium Monte Carlo algorithm, and this proved to be not just feasible but actually efficient. Monte Carlo procedures are inherently more mathematically flexible than molecular dynamics, and the development of such a nonequilibrium algorithm opens up many, previously intractable, systems for study. The transition probabilities that form part of the theory likewise include the influence of the reservoir, and they should provide a fecund basis for future theoretical research. The application of the theory to molecular-level problems answers one of the two questions posed in the first paragraph of this conclusion the nonequilibrium Second Law does indeed provide a quantitative basis for the detailed analysis of nonequilibrium problems. 

Another question is whether an endpoint reflecting the status of CMI should be included in any DIT protocol.1719 For the measurement of CMI, roundtable participants suggested that a validated DTH or T-cell responses to anti-CD3 be evaluated.38 The DTH assay is considered by the NTP as part of the Tier II test panel.3 Although reports indicate that the delayed-type hypersensitivity (DTH) response can be assessed in weanling rats.41 roundtable participants agreed that data are lacking as to whether cell-mediated immune (CMI) assessments in younger animals are feasible.38 Ultimately, the characterization of a validated endpoint which measures CMI, and the determination of whether such an endpoint should be an essential part of a DIT framework remain critical research needs. 

Participants in public-health studies that measure hundreds of biomarkers might give informed consent only with respect to the general objectives of the study on the grounds that detailed discussion of each biomarker is not feasible. However, failing to provide more detailed information raises ethical questions. The committee recommends research... 

There is a need to continue to perform research on methods of recycling tires, such as the use of crumb rubber in rubber products and plastics. Existing research on rubberized asphalt should be summarized, and a decision made regarding its feasibility for more widespread use, or if there are still technical or economic questions, determining exactly what additional research is needed to answer these questions, and then perform this research. States and Federal government, and environmental and transportation agencies, should coordinate research efforts so that fewer, more comprehensive research projects (particularly related to rubberized asphalt) can be performed. 

In our opinion, the data are sufficiently clear to suggest that when it is not feasible to test the mixture in question, mixture extrapolation is the preferred option compared to no extrapolation. Indeed, all literature observations suggest that applying mixture extrapolation is to be preferred over not applying mixture extrapolation. Technical options for extrapolation are concentration addition, response addition, and the mixed-model approach, of which concentration addition is most often applied. Exceptions may apply in cases that are more specific. For example, when it is clear that 2 compounds precipitate (a situation of no exposure due to chemical interactions in the environment), one should acknowledge this prior to assessing mixture risks by mixture extrapolation approaches. When the data of a study allow, refined conclusions are possible. For example, when the study design is appropriate and the mathematical models are appropriate, researchers are able to discriminate between concentration addition and response addition, and (with sufficient experiment efforts) between these models and the mixed-model approach. 

T nterest in the separation of isotopes started as a scientific curiosity. The question arose as to whether it was indeed at all feasible or possible to separate isotopes. After this question was answered in the affirmative (24), it became of interest to separate isotopes on a laboratory scale for use in scientific research. A few examples show the range of utility of separated isotopes. Deuterium has attained widespread use as a biochemical and chemical tracer. It is now abundantly available and is used as freely as any cheap chemical reagent. He has opened up an entirely new field of research in low temperature physics and has important applications in the production of temperatures below 1°K. with a thermal neutron cross section of 4,000 barns, has found wide use in nuclear particle detectors—neutron proportional counters. still finds use as a tracer, but in recent years its most frequent use has been in electron spin and nuclear magnetic resonance spectroscopy. occupies a unique position as the only usable tracer for nitrogen. finds application as a... 

For all these reasons, and more, marketing and clinical input on suitable formulations should be included in the earliest considerations of project feasibility, and it behooves the clinical researcher to be able to provide such input in an informed manner. Equally, we should understand the constraints, difficulties and regulatory ramifications that all of our colleagues experience, including those in the research pharmacy. At the end of the day, product licences are awarded and NDAs are approved typically after the resolution of at least as many questions about chemistry, manufacturing, and controls (for which read pharmaceutics ) as about clinical efficacy and safety. 

From the perspective of comparative welfare state research, the crucial question is whether there is a general and converging or a context-specific pattern of actual as well as potentially feasible activation strategies. 

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