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Fundamental Questions

At a time not too long ago, ethnic groups, or human races were defined by geography and appearence, most often simply by skin color, sometimes additionally by language. These factors are still considered by many people as main indicators, but at the present time, the scientifically defining factors are genetic differences between populations. [Pg.222]

It is true that the majority of genes in different human populations are identical. Nevertheless, it would be wrong and inappropriate to take this overall similarity as an opportunity to disavow the medical importance of interethnic divisions of the human species. [Pg.222]

A revolutionary book by Nei (11) entitled Molecular Evolutionary Genetics divided populations by their genetic diversities. More recently, this work has been greatly extended, mostly confirmed but with some changes, by Cavalli-Sforza et al. (12) in a book entitled The History and Geography of Human Genes.  [Pg.222]

These authors tested 120 allele frequencies in 42 human populations. They calculated from these measurements genetic distances between the populations and estimated the times of their separation. They summarized their data, and thus constructed nine population clusters (Fig. 1). The greatest differences were between African and all non-African populations, in support of the theory that all present human beings derived from a wave of emigrants who left Africa approximately 100,000 years ago. [Pg.222]

New Guinean and Australian Pacific Islander Southeast Asian Northeast Asian Arctic Northeast Asian Amerind 2 15 European [Pg.222]


Ultrasonic techniques are an obvious choice for measuring the wall thickness. In the pulse-echo method times between echoes from the outer and inner surface of the tube can be measured and the wall thickness may be calculated, when the ultrasonic velocity of the material is known. In the prototype a computer should capture the measuring data as well as calculate and pre.sent the results. First some fundamental questions was considered and verified by experiments concerning ultrasonic technique (Table I), equipment, transducers and demands for guidance of the tube. [Pg.895]

Aspects of the Jahn-Teller symmetry argument will be relevant in later sections. Suppose that the electronic states aie n-fold degenerate, with symmetry at some symmetiical nuclear configuration Qq. The fundamental question concerns the symmetry of the nuclear coordinates that can split the degeneracy linearly in Q — Qo, in other words those that appeal linearly in Taylor series for the matrix elements A H B). Since the bras (/1 and kets B) both transform as and H are totally symmetric, it would appear at first sight that the Jahn-Teller active modes must have symmetry Fg = F x F. There... [Pg.5]

Remark. The authors are well aware of the commonly shared belief within the physics MD community that the apparent chaos does not destroy all long term information, but only irrelevant information in particular, average quantities are supposed to be not sensitive to numerical perturbations. We do not aim at deciding about this fundamental question here. [Pg.101]

It also has interesting historical roots and, as we shall see, it raises fundamental questions regarding the boundary conditions at the wall, which apparently are not widely understood. We shall therefore investigate what is involved in formulating and solving this problem. [Pg.25]

Intensive, critical studies of a controversial topic also help to eliminate the possibility of errors. One of my favorite quotations is by George von Bekesy, a fellow Hungarian-born physicist who studied fundamental questions of the inner ear and hearing (Nobel Prize in medicine, 1961) ... [Pg.146]

If you cannot specifically answer these questions, then you have not formulated a proper research project. The choice of computational methods must be based on a clear understanding of both the chemical system and the information to be computed. Thus, all projects start by answering these fundamental questions in full. The statement To see what computational techniques can do. is not a research project. However, it is a good reason to purchase this book. [Pg.135]

The choice of which of these exciting species or forces, and hence technique, to use depends on the nature of the information sought about the surface. This article is organized around a discussion of techniques which can be used to answer the following important fundamental questions that are typically asked about surfaces and interfaces ... [Pg.268]

Two fundamental questions have emerged from these studies, ie, to what extent are agonists and antagonists binding similarly or differendy to the respective receptors, and can inhibitory compounds be developed that are active in vivo in humans as well as in vitro. An oxytocia antagonist that can block premature uterine contractions presents a promising example of the clinical utihty of such stmctures (47). Both linear as well as bicycHc modifications of these hormones also have provided new antagonist stmctures. [Pg.190]

Some fundamental questions should be answered prior to launching into the study details. [Pg.213]

Reactions of alkynes with electrophiles are generally similar to those of alkenes. Because the HOMO of alkynes (acetylenes) is also of n type, it is not surprising that there IS a good deal of similarity between alkenes and alkynes in their reactivity toward electrophilic reagents. The fundamental questions about additions to alkynes include the following. How reactive are alkynes in comparison with alkenes What is the stereochemistry of additions to alkynes And what is the regiochemistry of additions to alkynes The important role of halonium ions and mercurinium ions in addition reactions of alkenes raises the question of whether similar species can be involved with alkynes, where the ring would have to include a double bond ... [Pg.371]

Fundamental Questions in Quantum Mechanics, edited by L.M.Roth and A.Inomata, Gordon and Breach (1986) 291-307. [Pg.749]

It seems that indeed the answers to many fundamental questions are obtained, at least in qualitative form. Perhaps, the most important exception are thixotropic phenomena. There are many of them and the necessary systematization and mathematical generalization are absent here. Thus, it is not clear how to describe the effect of an amplitude on nonlinear dynamic properties. It is not clear what is the depth and kinetics of the processes of fracture-reduction of structure, formed by a filler during deformation. Further, there is no strict description of wall effects and a friction law for a wall slip is unknown in particular. [Pg.96]

Since the 1960s there has been considerable activity in the philosophy of science concerning the relationship of Kuhn s theory to that of Popper. Williams (1970) put forward the idea that Kuhn s system is based on what scientists do, whereas Popper s system is concerned with what scientists ought to do (but do not). The fundamental question therefore arises why do scientists not do what they ought to ... [Pg.214]

Bertran J. Some Fundamental Questions in Chemical Reactivity Theor. Chem. Acc. 1998 99 143-150... [Pg.308]

The basis for assessment of river quality is valid data, but the question of data validity is secondary to the fundamental question What is the purpose of the river quality assessment activity What questions are being asked In short the means are determined by the ends. If, for example, the intent of an assessment program is to ascertain compliance with law, then a fixed interval "grab sampling program could be established at various river system sites selected on the basis of established guidelines which are consistent with the... [Pg.242]

Now that we have reviewed some basic aspects of the chemical composition of the ocean we can turn to a more fundamental question. What processes determine the composition of the ocean Current evidence suggests that rivers are the most important contributors of dissolved substances to the ocean. Since there is geologic evidence that the concentration and composition of the ocean has been relatively constant over the last 1.5 billion years, we must conclude that the river input must be balanced by removal. [Pg.264]

The cyclic conjugation and orbital phase are both continuous in benzene. Electrons delocalize in a cyclic manner. The cyclic conjugation is discontinuous in borazine in Scheme 33). Electrons cannot delocalize in a cyclic manner, but only between the neighboring pairs of donors and acceptors. There arises a fundamental question how electrons delocalize in the isoelectronic molecules where C=C bonds are replaced with N-B bonds. [Pg.115]

Scientific studies of friction can be traced back to several hundreds years ago when the pioneers, Leonardo da Vinci (1452-1519), Amontons (1699), and Coulomb (1785), established the law of friction that "friction is proportional to the normal load and independent of the nominal area of contact, which are still being taught today in schools. Since then, scientists and engineers have been trying to answer two fundamental questions where friction comes from and why it exhibits such a behavior as described above. Impressive progress has been made but the mystery of friction has not been resolved yet. In an attempt to interpret the origin of... [Pg.171]

Nevertheless, it is obviously shown in Figure 18.1 that the stress-strain curve of the filled mbber gives the clear stress upturn, thus its tensile strength becomes 30 MPa. Therefore, the fundamental question is what happens or what stmcture is produced in the carbon black-filled mbber under large extension, which newly generates the stress upturn. In the case of the fine carbon black-fiUed system, when carbon blacks are dispersed ideally, the carbon gel makes the continuous phase at the... [Pg.532]


See other pages where Fundamental Questions is mentioned: [Pg.2926]    [Pg.62]    [Pg.3]    [Pg.6]    [Pg.534]    [Pg.1]    [Pg.13]    [Pg.22]    [Pg.137]    [Pg.286]    [Pg.21]    [Pg.359]    [Pg.199]    [Pg.371]    [Pg.376]    [Pg.377]    [Pg.801]    [Pg.51]    [Pg.261]    [Pg.488]    [Pg.507]    [Pg.589]    [Pg.634]    [Pg.90]    [Pg.40]    [Pg.222]    [Pg.223]    [Pg.13]    [Pg.97]    [Pg.214]    [Pg.54]   


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