Showing papers by "Stony Brook University published in 1970"

Methods for Computing Wagner Trees

Abstract: Farris, J. S. (Biol. Sci., State Univ., Stony Brook, N. Y.) 1970. Methods for computing Wagner Trees. Syst. Zool., 19:8342.-The article derives some properties of Wagner Trees and Networks and describes computational procedures for Prim Networks, the Wagner Method, Rootless Wagner Method and optimization of hypothetical intermediates ( HTUs). The Wagner Ground Plan Analysis method for estimating evolutionary trees has been widely employed in botanical studies (see references in Wagner, 1961) and has more recently been employed in zoological evolutionary taxonomy (Kluge, 1966; Kluge and Farris, 1969). Wagner Trees are one possible generalization of the most parsimonious trees of Camin and Sokal (1965). The Wagner technique is of con-siderable interest for quantitative evolution- ary taxonomists because it is readily pro- grammable and because the type of tree produced can tractably be extended to ap- plications in a variety of novel quantitative phyletic techniques. In this paper I shall formalize the concept of a Wagner Network and discuss a number of algorithms for calculating such networks. The rationale for the methods described will not be treated extensively here, as it is published elsewhere (Kluge and Farris, 1969).

Learned Associations Over Long Delays1

Abstract: Publisher Summary The literature of specific hungers and bait shyness contains much indirect evidence of learning involving prolonged delay of reinforcement. Specific hunger refers to the selective feeding by animals as they learn to correct a specific dietary deficiency, such as thiamine deficiency, while bait shyness describes the rejection of poisoned baits by animals, which have survived a previous poisoning attempt. It seems unlikely that learning can take place at all with delays of more than a few seconds. Instances of learning with protracted delays of reinforcement are always cases where immediate secondary reinforcement occurs. It is generalized that delayed reinforcement is not effective except under elaborate training conditions. However, when the response is ingestion and the rewards or punishments are changes in the physiological state of the organism, this generalization appears to be incorrect. Most specific hungers can be explained in terms of learned associations involving delayed aftereffects; an exception is the specific hunger for sodium, which appears to be largely innate. If rats are subjected to sodium deficiency and recover from it by drinking salt water, they tend to drink an abnormally large amount of salt water after the deficiency is relieved.

Adaptive Hierarchical Clustering Schemes

Abstract: Rohlf, F. J. (Biological Sciences, State Univ., Stony Brook, N. Y. 11790) 1970. Adaptive hierarchical clustering schemes. Syst. Zool., 18:58-82.-Various methods of summarizing phenetic relationships are briefly reviewed (including a comparison of principal components analysis and non-metric scaling). Sequential agglomerative hierarchical clustering schemes are considered in particular detail, and several new methods are proposed. The new algorithms are characterized by their ability to "adapt" to the possible trends of variation found within clusters as they are being formed. A nonlinear version allows the isolation and description of clusters which are parabolic, ring-shaped, etc., by the introduction of appropriate dummy variables. Procedures for computing the best fitting trend line through the cluster are also presented, and problems in measuring the amount of information lost by clustering are discussed. [Phenetics; cluster analysis; numerical taxonomy.] This paper is concerned with a brief review of some of the techniques of summarizing phenetic similarities that have been proposed for use in numerical taxonomy. One class of methods (sequential agglomera'tive) is considered in detail and new procedures which allow for elongated and curvilinear clusters are proposed. The "taxonomy problem" in biology can be described as follows: Given a set of specimens ("operational taxonomic units" or OTU's, Sokal and Sneath, 1963, which may represent taxa of any rank) known only by a list of their properties or characters, we wish to find the "best" way of describing their often complex patterns of mutual similarities (phenetic relationships). Such relationships do not necessarily imply evolutionary (cladistic) relationships (for a discussion of these approaches, see Sokal and Camin, 1965). The methods that have been developed appear to have a more general application than just in biological taxonomy, but there are certain facts and assumptions that can be made in biology which influence our choice of methods. As a result, the techniques may or may not be completely valid in other fields. Some of the considerations which influence the development of cluster analyses in biological taxonomy are the following: (1) "All things being equal" we would hope that a system of nested clusters would be found. This is due to the fact that evolution is believed usually to be a divergent process and the distribution of OTU's in a phenetic space should to some extent reflect this. There are, of course, exceptions to this overall rule which are very important, such as those provided by hybridization and clinal variation. (2) Another consideration is the nature of the character set representing each OTU. We would like to use a "random sampling of characters" or at least a "representative" sampling of characters. But since different sets of characters seem to yield slightly different systems of relationships (Rohlf, 1963; Ehrlich and Ehrlich, 1967; Michener and Sokal, 1966), biologists may have to get used to the idea of using different classifications, based upon different sets of characters, each best for its own special purpose, with overall similarities based on the total character set available at any one time. (3) The selection of OTU's is also not random. Since we cannot study all organisms, we must select those which are of immediate interest. But even with a specified group of organisms, we usually cannot sample at random. This is so because the distributions of recent (and even fossil) organisms are clumped in a phenetic hyperspace. One needs to pass up many very similar, common specimens to obtain a more interesting sampling of different kinds of organisms. Thus, a preliminary screening of individuals according to their apparent similarities must be made before one can make detailed measurements to analyze their phenetic relationships quan-

Age Specificity and Ecological Theory

Abstract: This paper attempts first to deal with the question of aging as a byproduct of natural selection, drawing on the theories of Medawar, Williams and Hamilton, and second, to apply the conclusions to considerations of population and behavioral ecology. It is concluded that: (1) Age—specific mortality should drop to a minimum prior to earliest reproductive age and then rise with age. (2) Age—specific fecundity should rise with age to a peak, which may occur at almost any age depending on the sort of organism considered, and then fall. (3) A sudden increase in mortality at a given age will result in natural selection favoring higher relative mortality at immediately preceding and following ages, and lowered fecundity immediately after that age. (4) A sudden increase in fecundity at a given age will result in natural selection favoring relative higher mortality in early life and immediately after that age, as well as relaxed selection for increased fecundity, especially at middle and late ages. (5) Selection acts to make increasingly steep the survivorship curve of a population declining or fluctuating due to changes in mortality. (6) Selection acts to postpone reproductive effort in populations declining or fluctuating due to changes in fecundity. (7) If mortality is very low, animals, as they age, should ideally take greater risks to secure reproductive success. (8) The nature of altruistic behavior may be age specific, with older individual more characteristically altruistic and younger individuals more characteristically pampered. (9) Intergroup hostilities should be largely directed toward certain age groups.

Neo-Noncontinuity Theory

Abstract: Publisher Summary This chapter discusses the neo-noncontinuity theory. Noncontinuity theory is a theory dealing with choice responses during discrimination learning. Specifically, it holds that the choices reflect hypotheses that S is testing. It is less well known that noncontinuity theory is today enjoying a revival. Indeed, it may fairly be characterized as the leading theory of discrimination learning by adult humans. Theory, then, is proceeding at two levels, one abstract, probabilistic, intended for a variety of problem-solving situations; the other qualitative in description, concerned with the specific processes in the specific task. The development along these lines has already produced some notable accomplishments and promises both application to a greater variety of discrimination tasks and a finer analysis of each task. The concomitant development of theory and of probes, such as the blank-trials probe, should yield a rigorous, detailed, yet comprehensive description of human discrimination learning.

Neural Control of Firefly Luminescence

Abstract: Publisher Summary The flash of the adult firefly is a brilliant burst of light produced by the coordinated participation of hundreds of units is an outstanding example of an insectan effector response. Because it is so easily observed it provides an excellent tool for the analysis of neural function in an insect. Study of the mechanism of flash control over the last 20 years has revealed a neuroeffector system which contains a number of unique features. The adult firefly is also capable of producing a wide range of qualitatively different light responses. These include glows of varying intensity and duration, and scintillation, which is therapid, uncoordinated flashing of hundreds of individual elements. This chapter focuses on the physiological basis of three related aspects of the general problem of neural control. It describes the chain of neural events which begin in the brain and culminate in the light response. This represents the basic machinery of neural control of luminescence. Only those aspects of lantern morphology, luminescence biochemistry and development which contribute directly to an understanding of neural control mechanisms have been included. The chapter also discusses the anatomy of the firefly lantern, biochemistry of the light reaction, pharmacology of the lantern, and the neuroeffector response unit and its control.

Absolute auditory threshold and threshold of unpleasantness of chronic schizophrenic patients and normal controls.

Abstract: The method of average error was modified tor research in schizophrenia and was used in establishing both the absolute auditory threshold and the threshold of unpleasantness. The results showed chronic schizophrenic patients had a higher absolute threshold but a lower threshold for when a tone became unpleasantly loud. The results add evidence that chronic schizophrenic patients find external stimulation aversive; they point out the narrow range of auditory stimuli in which schizophrenics function; and suggest that the same auditory stimuli cannot be considered equivalent for schizophrenic patients and normal controls. The results of a stimulus-seeking experiment showed that chronic, nonparanoid schizophrenic patients preferred a noise stimulus of varying intensity to be off, while normal controls preferred it on (Levine, 1967). These results were interpreted as indicating a motivational process in which schizophrenic patients avoid external stimulation simply because external stimulation is unpleasant to them. However, another explanation for the findings is that schizophrenic patients have greater auditory sensitivity than normals. If patients were more sensitive, then the stimuli used would not be perceptually equivalent and would tend to be differentially aversive. The patients would then be expected to show the obtained results of preferring the noise off. Previous research in schizophrenic audition

Critical Magnetic Scattering in Manganese Fluoride

Abstract: The angular dependence of the quasielastic magnetic scattering has been measured in Mn${\mathrm{F}}_{2}$ in the critical region $Tg{T}_{N}$. The temperature dependence of the inverse correlation range and the staggered mode susceptibility for both transverse and longitudinal spin fluctuations were observed as a function of incident neutron energy over the range $56l{E}_{0}l134$ meV. The validity of the quasielastic approximation for this energy region was verified. The data for the longitudinal fluctuations were found to follow simple power laws with the critical exponents $\ensuremath{ u}=0.634\ifmmode\pm\else\textpm\fi{}0.02$, $\ensuremath{\gamma}=1.24\ifmmode\pm\else\textpm\fi{}0.02$. An $\ensuremath{\eta}$ fitted to the data closest to ${T}_{N}$ gave $\ensuremath{\eta}=0.05\ifmmode\pm\else\textpm\fi{}0.02$. The transverse fluctuations are not divergent at ${T}_{N}$, although for $Tg{T}_{N}$ they can be described by power-law fits taken with respect to a temperature ${T}_{\ensuremath{\perp}}\ensuremath{\approx}66\ifmmode^\circ\else\textdegree\fi{}$K by indices ${\ensuremath{ u}}_{\ensuremath{\perp}}=0.63\ifmmode\pm\else\textpm\fi{}0.08$, ${\ensuremath{\gamma}}_{\ensuremath{\perp}}=1.47\ifmmode\pm\else\textpm\fi{}0.1$. The actual critical temperature is ${T}_{N}=67.458\ifmmode\pm\else\textpm\fi{}0.008$.

Evidence for an Isomeric 29/2+ Level in 211At

Abstract: A 70 ns isomeric state at 2 641 keV has been produced in the 209Bi(α,2n)211 At reaction and interpreted as the 29/2+ state of the h9/22 i13/2 proton configuration. It decays to the states (h9/22 f7/2)23/2, (h9/23)21/2, (h9/23)17/2, (h9/23)13/2 and (h9/23)9/2 by a straight cascade of transitions with energies (multipolarities) 713.3 keV (E3), 511.6 keV (M1), 96.0 keV (E2), 253.4 keV (E2), and 1 066.9 keV (E2). There is also indirect evidence for a 24.4 keV (E2) branch to a (h9/22 i13/2)25/2 state followed by a 688.9 keV (E1) transition to the 21/2- state. The reduced transition rate B(E3, 29/2+ → 23/2-) = 51 000 e2 fm6 can be reproduced by taking the value 0.9 MeV for the particle-phonon coupling matrix element i13/2, 3-; 7/2|Hcoupl|f7/2.

Pion pion dynamics in the sigma model

Abstract: We propose an unambiguous way of constructing amplitudes which satisfy both unitarity and the current-algebra constraints. This consists in working out higher-order corrections on a Lagrangian which produces the correct soft-pion limit in the tree approximation. We consider $\ensuremath{\pi}\ensuremath{\pi}$ scattering in the $\ensuremath{\sigma}$ model, and we compute the perturbation series up to second order. The renormalization procedure preserves the partially conserved axial-vector current condition and the current-algebra constraints at each order. In order to sum the strong-coupling perturbation series, we use the Pad\'e-approximation technique. Thereby, our partial-wave amplitudes satisfy unitarity. The $\ensuremath{\rho}$ and ${f}_{0}$ resonances are generated, although they were not present in the Lagrangian. Our unitary amplitudes satisfy crossing symmetry to a very good accuracy, showing the consistency of the results. Our results are in agreement with the "up-down" solution of the $I=0$, $s$-wave $\ensuremath{\pi}\ensuremath{\pi}$ phase shift, with a very broad $\ensuremath{\sigma}$ resonance; the $I=2$ $s$-wave phase shift is repulsive, and agrees very well with experiment.

The Missing Parts of the Towneley Cycle

Abstract: DESPITE a number of scholarly editions and textual studies, the manuscript of the Towneley plays suirprisingly has yet to be examined closely for its missing parts. It will be my purpose in this paper to undertake such an examination and to discuss the textual as well as historical significance of the most important lacunae in the manuscript. In so doing, I shall propose two major conclusions: first, that the Towneley cycle once contained a very full set of banns, and second, that the largest lacuna in the manuscript is tie result of editorial tampering linked with the Reformation. The Towneley MS, owned by the Henry E. Huntington Library (Accessioni Mark HM 1), consists of 132 folio leaves of vellum, twelve inches long by eight and one half inches wide. It is bound into nineteen quires or parts of quires, each of which originally contained eight leaves. Extant signatures range from b to V and appear on the first four leaves of each quire. The last four leaves, though unmarked, are conjugate with the first four so that the first leaf is joined with the eighth, the second with the seventh, the third with the sixth, and the fourth with the fifth. All extaInt signatures, moreover, appear in the lower right-hand corner, and all are in black except two (1 and s), which are in red.2 In my recent examination of the malnuscript, I noted that the quires b to r are clearly visible. But the exta nt quires from s to V are sewn together. This latter observation, extending on one made by Louis Wann in an earlier examination,3 is of some importance to my argument since it has to do with one of the major lacunae in the manuscript. In proceeding now with a description of the several lacunne, I wish first briefly to note two about which I h.ave nothing new to add except to say that bo-Lh involve the loss of the two middle leaves in a quire. Both are, therefore, quite likely the result of accidental loss. The first of these occurs in Quire d, between f. 15v of the unfinished Abraham play aInd f. 16r, the middle of the fragmentary Isaac play. The two missing leaves, therefore, contained the en(I of the Abraham play and the beginning of the Isaac play. The second of these la.cunae occuirs between f. 61v

13C Nuclear Magnetic Resonance Spectra of Proteins

Abstract: Although 13C has a natural abundance of only 1.1% and gives inherently much weaker nuclear magnetic resonance signals than does does 1H, it has been found that 13C nuclear magnetic resonance spectra of aqueous solutions of naturally occurring proteins can be observed. A spectrum of hen's egg white lysozyme, an enzyme of molecular weight approximately 14 300, containing 129 amino acid residues, has been partially analyzed by comparison with a computer-simulated spectrum.

Cross-National Dimensions of Political Competence

Abstract: Political efficacy, the belief that the ruled in a political system have some capacity for exercising influence over the rulers, has been studied extensively by political researchers. A selected bibliography compiled by Easton and Dennis in early 1967 contains some thirty books and articles which have dealt in one way or another with political efficacy and its correlates.' And this bibliography could be updated considerably. Substantial theoretic import has been attributed to political efficacy. Easton and Dennis consider the SRC sense of political efficacy construct to be an important determinant of the persistence of democratic regimes. They argue that beliefs in political efficacy provide "a reservoir of diffuse support upon which the system can automatically draw in normal times, when members may feel that their capacity to manipulate the environment is not living up to their expectations, and in special periods of stress, when popular participation may appear to be pure illusion or when political outputs fail to measure up to insistent demands,"2 A related construct, termed "subjective competence" by Almond and Verba, is based on different indicators but interpreted as substantively equivalent to the SRC construct. On the basis of their analysis of the Five-Nation data, Almond and Verba arrive at the general conclusion that "the self-confident [subjectively competent] citizen appears to be the democratic citizen." The concept of political competence, as formulated by Barnes, subsumes political efficacy under the aegis of an individual attribute consisting of "political skills plus the sense of efficacy necessary for effective political action."4 Barnes contends that high levels of political competence dispose individuals to prefer democratic styles of leadership, while low levels dispose individuals to