Showing papers by "University of California, Santa Barbara published in 1975"
TL;DR: The chapter discusses the relationship between learning and functional response, and indicates the importance of two features, developmental response and numerical response, of the interaction.
Abstract: Publisher Summary This chapter discusses predation and population stability. It describes some potentially stabilizing features that have been found in real systems and shows the main stabilizing features discovered in the field of studies—refuges, spatial heterogeneity—or probably can be modified to incorporate them, for example, invulnerable classes of prey. It also touches two obvious features of reality, namely time lags, which destabilize the interaction, and density dependence (for example, resource limitation) in the prey, which is stabilizing. General model (the Lotka-Voltema equations) is also discussed and a criterion for estimating its stabilizing effect is presented. The chapter discusses the relationship between learning and functional response, and indicates the importance of two features, developmental response and numerical response, of the interaction. The chapter examines other aspects, namely the consequences for stability arising from the response of the individual predator to changes in the density of its prey (or to changes in the densities of two or more prey).
1,465 citations
TL;DR: Avian brood parasitism, the phenomenon in which certain birds, the parasites, deposit their eggs in the nests of other birds, their hosts, is especially well suited to teleonomic studies since it provides a system in which the presence or absence of relatively obvious adaptations can be examined in two interacting genetic lineages.
Abstract: The term “teleonomy” has been suggested by Williams (1966:258) to describe the scientific study of adaptations. Williams indicated that relatively few evolutionary studies deal primarily with teleonomy despite the fact that adaptation is the most basic feature of evolution and of all biology. Avian brood parasitism, the phenomenon in which certain birds, the parasites, deposit their eggs in the nests of other birds, their hosts, is especially well suited to teleonomic studies since it provides a system in which the presence or absence of relatively obvious adaptations can be examined in two interacting genetic lineages. Parasitism is typically detrimental to the host’ s reproductive efforts and selection favors defenses that reduce the impact of the parasite. These host defenses are in turn damaging to the parasite’ s reproductive efforts and selection favors counter-adaptations by the parasite. cause the death of all of the host’ s own young through competition for food (Friedmann 1963 ) . In certain cases, brood parasites seem to have extirpated or caused declines of local host populations (Schiermann in Southern 1954:221, Bond in Friedmann 1971:250, Mayfield 1961a). Thus, the adaptive value of host defenses is clearly very great.
444 citations
TL;DR: Giselin (2) shifted the focus by suggesting that if members of one sex increase in fertility more rapidly with age than those of the other, then natural selection will favor a genotype whose individuals are all born into the sex that suffers less from being young.
Abstract: Many writers have discussed sequential hermaphroditism, wherein individuals are all born of one sex and change to the other as they grow older, in terms of its advantage to the species (1). Ghiselin (2) shifted the focus by suggesting that if members of one sex increase in fertility more rapidly with age than those of the other, then natural selection will favor a genotype whose individuals are all born into the sex that suffers less from being young (the sex whose fertility increases
369 citations
TL;DR: In this paper, a generalized Ginzburg-Landau theory is proposed to describe the phase transition of an array of weakly coupled pseudo-one-dimensional chains, which is based on a mean-field approximation.
Abstract: A generalized Ginzburg-Landau theory is suggested to describe the phase transition of an array of weakly coupled pseudo-one-dimensional chains. Using a mean-field approximation, the coupled-chain problem is reduced to that of a single chain in an effective field. The finite-range correlations which develop along the chain are treated using exact one-dimensional solutions. The results obtained are then used to construct a generalized Ginzburg-Landau theory. We argue that this approach provides a means of treating the remaining slowly varying long-range fluctuations. Results are given for a variety of arrays consisting of Ising, classical Heisenberg, real and complex ${\ensuremath{\psi}}^{4}$ chains.
314 citations
TL;DR: Differences between two groups of fish show that switching behavior is more efficient and should be selected for, and confirms previous generaliza- tions about switching.
Abstract: Guppies (Poecilia ieticulatus) were given two prey: Drosoplhila (on the water surface) and tubificid worms (on the aquarium bottom). The densities of the two prey were varied gradually over 12 days, from 4:1 to 1:4, and we measured the predators' diets, time of each meal, and time spent at the top, middle, and bottom of the aquarium. The guppies switched, attacking disproportionately whichever of the two prey was more abundant. Switching resulted when the fish increased the fraction of time spent at the surface as the fraction of Drosoplhila available increased. They did this in response to changing reward rates. Switching caused density-dependent mortality. Differences between two groups of fish show that switching behavior is more efficient and should be selected for. The result confirms previous generaliza- tions about switching.
297 citations
TL;DR: In this article, the authors studied the role enactment patterns of role enactment in an urban neighborhood and found that speaking "like a man" in Teamsterville was a common way to act like a man.
Abstract: (1975). Speaking “like a man” in Teamsterville: Culture patterns of role enactment in an urban neighborhood. Quarterly Journal of Speech: Vol. 61, No. 1, pp. 13-22.
268 citations
TL;DR: In this article, a normalized digital filter structure based upon an orthonormal polynomial expansion is presented, recursively designed, which has several predictable stability properties in the presence of time-varying parameters, and appears to have roundoff noise properties which are superior to other known filter structures.
Abstract: A normalized digital filter structure is presented, based upon an orthonormal polynomial expansion. This structure is recursively designed, has several predictable stability properties in the presence of time-varying parameters, and appears to have roundoff noise properties which are superior to other known filter structures, particularly in the presence of clustered poles. Each section of the filter can be precisely implemented by one complex multiply.
235 citations
TL;DR: The extreme selective responding and the resulting bizarre stimulus control found are discussed in relation to the issue of setting generality of treatment gains.
Abstract: This study was designed to assess the transfer of treatment gains of autistic children across settings. In the first phase, each of 10 autistic children learned a new behavior in a treatment room and transfer to a novel extra-therapy setting was assessed. Four of the 10 children showed no transfer to the novel setting. Therefore, in the second phase, each child who failed to transfer participated in an analysis of stimulus control in order to determine the variables influencing the deficit in transfer. Eachof the four children who did not transfer were selectively responding to an incidental stimulus during the original training in the treatment room. Utilizing a reversal design, each of the four children responded correctly in the extra-therapy setting when the stimulus that was functional during training was identified and introduced into the extra-therapy setting. The extreme selective responding and the resulting bizarre stimulus control found are discussed in relation to the issue of setting generality of treatment gains.
224 citations
TL;DR: This comparison indicates that all species, except the two parasites and the one diurnal vertical migrator, are able to regulate their QO2 to at least the lowest pO2 they encounter in nature (as low as 4 mm Hg O2 in some cases).
224 citations
TL;DR: Lead isotopic analyses of a suite of basaltic rocks from the Juan de Fuca-Gorda Ridge and nearby seamounts confirm an isotopically heterogeneous mantle known since 1966.
Abstract: Lead isotopic analyses of a suite of basaltic rocks from the Juan de Fuca-Gorda Ridge and nearby seamounts confirm an isotopically heterogeneous mantle known since 1966. The process of mixing during partial melting of a heterogeneous mantle necessarily produces linear data arrays that can be interpreted as secondary isochrons. Moreover, the position of the entire lead isotope array, with respect to the geochron, requires that U/Pb and Th/Pb values are progressively increased over the age of the earth. Partial melting theory also dictates analogous behavior for the other incompatible trace elements. This process explains not only the LIL element character of MOR basalts, but also duplicates the spread of radiogenic lead data collected from alkali-rich oceanic basalts. This dynamic, open-system model of lead isotopic and chemical evolution of the mantle is believed to be the direct result of tectonic flow and convective overturn within the mantle and is compatible with geophysical models of a dynamic earth.
187 citations
TL;DR: It is concluded that eukaryotic cells have yet to be found in deposits younger than latest Precambrian, and genes which are outside of the nucleus are probably now better designated as "extranuclear" or, where the information available warrants, a more specific term such as organelle gene, mitochondrial gene or mitogene, plastid gene or plastogene appears suitable.
Abstract: other hand, S. M. Awramik, S. Golubic, and E. S. Barghoorn [Absir. Geol. Soc. Am. 4 (7), 438 (1972)1 have concluded from a reassessment of the widely accepted cytological evidence that eukaryotic cells have yet to be found in deposits younger than latest Precambrian. 12. F. Sherman, J. W. Steward, E. Margoliash, J. Parker, W. Campbell, Proc. Natl. Acad. Sci. U.S.A. 55, 1498(1966). 13. W. D. Bell, L. Bogorad, W. J. Mcilrath, Bot. Gaz. 124, 1 (1962); B. Walles, in BiochemistrY of Chloroplasts, T. W. Goodwin, Ed. (Academic Press, New York, 1967), vol. 2. 14. C. L. F. Woodcock and L. Bogorad, in Stru-ture and Function of Chloroplasts, M. Gibbs, Ed. (Springer-Verlag, New York, 1971), pp. 89-128. 15. R. M. Smillie, N. S. Scott, D. G. Bishop, in Biochemistrv of Gene E.rpression in Higher Organisms, J. K. Pollak and J. W. Lee, Eds. (Australian & New Zealand Book, Sydney, 1973), pp. 479503. 16. C. J. Leaver and M. A. Harney, Biochem. Soc. Symp. 38, 175 (1974). 17. L. J. Mets and L. Bogorad, Science 174, 707 (1971). 18. Proc. Natl. Acad. Sci. U.S.A. 69, 3779 (1972). 19. ,__ A nal. Biochem. 57, 200 (1974). 20. M. R. Hanson, J. N. Davidson, L. J. Mets, L. Bogorad, Mol. Gen. Genet. 132, 105 (1974). 21. J. N. Davidson, M. R. Hanson, L. Bogorad, ibid., p. 119. 22. Extranuclear genes from both gametes are retained in less than I percent of Chlamydomonas zygotes normally. R. Sager and Z. Ramanis [Proc. Natl. Acad. Sci. U.S.A. 58, 931 (1967)] found that the frequency of biparental, or "exceptional," zygotes can be increased up to 50 percent if the mt+ parent is irradiated with ultraviolet light before mating. The term "cytoplasmic gene" is becoming confusing and unserviceable because of changes in the usage of the term cytoplasm. Genes which are outside of the nucleus are probably now better designated as "extranuclear" or, where the information available warrants, a more specific term such as organelle gene, mitochondrial gene or mitogene, plastid gene or plastogene appears suitable. The word cytoplasm is defined as all of a eukaryotic cell's protoplasm except for its nucleus. In current usage, mitochondria and plastids are considered to be in the cytoplasm but not part of it. Thus, as used in this article and generally, "cytoplasmic ribosomes" exclude those of the organelles. Some authors have attempted to substitute "cytoplasmic matrix" for cytoplasm in order to avoid ambiguity, while others have suggested the wider use of "cytosol." Each of these suggestions has other difficulties. 23. M. R. Hanson and L. Bogorad, unpublished. 24. D. Bastia, K.-S. Chiang, H. Swift, P. Siersma, Proc. Natl. Acad. Sci. U.S.A. 68, 1157 (1971); D. Bastia, K.-S. Chiang, H. Swift, Abstratts of Papers, 11th Annual Meeting of the American Societi of Cell Biologists (1971), p. 25. 25. L. Bogorad, L. J. Mets, K. P. Mullinix, H. J. Smith, G. C. Strain, Biochem. Soc. Smnp. 38, 17 (1973). 26. R. A. Raff and H. R. Mahler, Science 177, 575 (1972). 27. T. Uzzell and C. Spolsky, Am. Sci. 62, 334 (1974). 28. R. R. Meyer,J. Theor. Biol. 38, 647 (1973). 29. S. Nass, Int. Res. Cytol. 25, 55 (1969). 30. K. Apel and H.-G. Schweiger, Eur. J. Bio(chenm. 25, 229 (1972). 31. K. Kloppstech and H.-G. Schweiger, E.YP Cell Res. 80, 69 (1973). 32. P. Chan and S. G. Wildman, Biochim. Biophys. Acta 277, 677 (1972); N. Kawishima and S. G. Wildman, ibid. 262,42 (1972). 33. D. P. Bourque and S. G. Wildman, Biochem. Biophys. Res. Commun. 50, 532 (1973). 34. G. Eytan and 1. Ohad, J. Biol. Chem. 245, 2479 (1970); ibid 247, 112, 122 (1972); J. K. Hoober, ibid. 245, 4327 (1970); and G. Blobel, J. Mol. Biol. 41, 121 (1969). 35. A. Tzagoloff, J. Biol. Chenm. 246, 3050 (1971); and P. Meagher, ibid. 247, 594 (1972). 36. T. L. Mason and G. Schatz, ibid. 248, 1355 (1973); M. S. Rubin and A. Tzagoloff, ibid., p. 4275; W. Sebold, H. Weiss, G. Jackl, Eur. J. Biochem. 30, 413 (1972); M. J. Vary, P. R. Stewart, A. W. Linnane, Arch. Biochem. 22, 19 (1971); H. Weiss, W. Sebold, T. Bucher Eur. J. Biochem. 22, 19 (1971). 37. R. S. Criddle, B. Dan, G. E. Kleinkopf, R. C. Huffaker, Biochem. Biophys. Rev. Commun. 41, 621 (1970). 38. G. E. Blair and R. J. Ellis, Biochim. Biophys. Acta 319, 223 (1973). 39. L. R. Gooding. H. Roy, A. T. Jagendorf, Arch. Biochem. Biophjs. 159, 324 (1973); J. C. Gray and R. G. 0. Kerwick, FEBS (Fed. Eur. Biochem. Soc.) Lett. 38,67 (1973). 40. This discussion of intracellular evolution and gene dispersal raises a question about lysosomes, other microbodies, arld elements of the Golgi complex. Could they have also originated by endosymbiosis or the cluster-clone path and lost all of their genes to other genomes? 41. E. Ebner, T. L. Mason, G. Schatz, J. Biol. Chem. 248, 5369 (1973). 42. R. E. Kellems, V. F. Allison, R. A. Butow, ibid. 249, 3297 (1974). References to other examples of the association of cytoplasmic ribosomes with mitochondria are given in this paper. 43. R. E. Kellems and R. A. Butow, J. Biol. Chem. 247, 8043 (1972); K. Apel and H.-G. Schweiger, Eur. J. Biochem. 38, 373 (1973). 44. 0. Weeks and S. R. Gross, Biochenm. Genet. 5, 505 (1971). 45. P. Raven, Science 169, 641 (1970). 46. R. Kolodner and K. K. Tewari, Proc. Nail. Acad. Sci. U.S.A. 69, 1830 (1972). 47. C. P. Hollenberg, P. Borst, E. F. J. van Bruggen, Biochim. BiophYs. Acta 209, 1 (1970). 48. E. Agsterribe, A. M. Kroon, E. F. J. van Bruggen, ibid. 269, 299 (1972). 49. Y. Suyama and K. Miura, Proc. Nail. Acad. Sci. U.S.A. 60, 235 (1968). 50. P. Borst and A. M. Kroon, Int. Rev. Clvtol. 26, 107 (1969). 51. M. M. K. Nass, J. Mol. Biol. 42, 529 (1969). 52. W. C. Allee, A. E. Emerson, 0. Park, T. Park, K. P. Schmidt, Principles of Animal Ecology (Saunders, Philadelphia and London, 1950); E. 0. Wilson, The Insect Societies (Belknap, Cambridge, Mass., 1971). 53. P. S. Leboy, E. C. Cox, J. G. Flaks, Proc. Nail. Acad. Sci. U.S.A. 52, 1367 (1964). 54. The preparation of this article and some of the research discussed here were supported in part by NIH grant GM 20470 and by the Maria Moors Cabot Foundation of Harvard University. I thank Dr. C. W. Birky for his critical reading of an earlier version of this article and for his helpful suggestions.
TL;DR: The results from a large number of new experiments reveal that rejector-species do indeed recognize their own eggs and reject any egg-type in the minority.
TL;DR: Algal succession within a subtidal forest of the giant kelp Macrocystis pyrifera was studied by following colonization and community development on concrete blocks fastened to the bottom, indicating that most species have either a spring-summer or fall-winter period of maximum reproduction.
Abstract: Algal succession within a subtidal forest of the giant kelp Macrocystis pyrifera was studied by following colonization and community development on concrete blocks fastened to the bottom. Sets of blocks were placed in the bed at 3-month intervals. Subsequent algal development on each set was followed for over a year. All macroscopic species attached to the substrata were noted, and the number and lenght of basal branches determined every 1 to 3 months. Colonizing plants fell into 3 categories: rapid-growing ephemerals, and rapid and slow-growing perennials. Ephemerals such as Giffordia (Ectocarpus) mitchellae, Colpomenia peregrina, and diatom films generally produced and initial bloom on the blocks but were gradually replaced by perennials (articulated corallines, Rhodymenia spp., Gigartina spp.) characteristic of the mature kelp community. These stages, rather than representing “ecological” succession, seemed to reflect differences in growth rate and success in interspecific competition for space and light. Colonization on the blocks varied with season, indicating that most species have either a spring-summer or fall-winter period of maximum reproduction. M. pyrifera sporophyte colonization was greatest in spring. During community development, algal diversity (H), number of species (s) and evenness (J) all reached a peak within 100 to 200 days regardless of the time the blocks were started. Diversity and number of species then fell as ephemeral species disappeared. These species were apparently unable to compete with perennials and, once gone, did not recolonize. Evenness remained high.
TL;DR: Caging experiments suggest that predatory fishes and sea-stars indirectly affect the algal community by removing sessile animals (primarily bryozoans) which compete with the algae for space.
Abstract: The effects of small and large-scale roughness, overstory development, competition for space with sessile animals, and grazing on algal community development in a subtidal Macrocystis pyrifera forest were examined using specially prepared concrete blocks as substrata. Variation in small-scale roughness (crevices and grooves in the order of 0.1 to 3 mm width and depth) had no significant effects on community composition. However, M. pyrifera colonization, algal diversity, and sessile animal biomass were higher near the upper horizontal edges of blocks and concrete prisms. This “edge” effect may result from a combination of increased spore and larval settlement and enhanced growth of plants and animals associated with the turbulent eddies formed around these obstructions. Natural and experimentally produced variations in the algal overstory demonstrated that the presence of an overstory can reduce algal diversity and cover beneath. Caging experiments suggest that predatory fishes and sea-stars indirectly affect the algal community by removing sessile animals (primarily bryozoans) which compete with the algae for space. The exclusion of grazers resulted in increased growth of Gigartina spp. Selective grazing on this genus may account for its reduced abundance in the study area.
TL;DR: Observations are consistent with the idea that a large negative (internal) potential develops across the inner membrane of the mitochondrion during energization and with other aspects of the chemiosmotic hypothesis.
TL;DR: In this paper, the authors formulate and discuss Reggeon field theory, which enables one to systematically analyze the exchange of Regge poles and associated branch points in high energy hardron scattering.
01 Apr 1975
TL;DR: Having been delegated the authority to make the key decisions, effective corporate power is conventionally defined, following A. A. Berle, Jr. and Gardiner Means as the ability to choose the membership of the board.
Abstract: Dans l'introduction, l'auteur presente le probleme de l'etude des conseils de direction des grandes compagnies americaines par l'analyse des reseaux. En effet, l'emploi le plus courant d'un membre d'un conseil de direction d'une compagnie est celui de directeur du conseil d'une autre compagnie. L'etude de cette question s'est limitee jusqu'ici a des sous-ensembles prealablement choisis de la population des grandes compagnies. Ce type d'etude, en outre, s'est presque toujours base sur une orientation theorique definie d'avance.Dans la deuxieme partie de cet article, l'auteur decrit les quatre orientations theoriques principales : controle directorial ; controle de l'environnement et reciprocite ; controle financier ; controle par hegenomie de classe. Les resultats prevus par chacune de ces orientations sont aussi clairement decrits.Dans la troisieme partie, l'auteur presente la methode de recherche des "cliques" a l'interieur d'un reseau dense de liens entre des points. Comme l'auteur s'est donne comme but...
TL;DR: The results are fully consistent with the predictions of the ALLEN-NANNEY-SCHENISTED model concerning the replication and distribution of functional gene copies, and suggest that the segregating genetic units in the macronucleus are in effect haploid.
Abstract: The objective of this study was to test the idea that the macronuclear (somatic) genetic information is randomly distributed at each cell division in Tetrahymena pyriformis , syngen 1. We took advantage of a quick and reliable test for the detection of stable vegetative segregants in clones heterozygous for ts2 , a heat-sensitive mutation. Clones that originated from cells inferred to contain very few (1-3) copies of the ts2 + allele in their macronuclei were selected for pedigree analysis. Experimental results were compared with the results of a computer simulation of the experiment. Our results are fully consistent with the predictions of the Allen-Nanney-Schensted model concerning the replication and distribution of functional gene copies. This model proposes that the macronucleus contains many functional copies of a given gene that are duplicated once during the cell cycle and are randomly distributed to the two-daughter nuclei. Our work has provided a more sensitive test of the assumption of randomness than was previously available. Our evidence for complete randomness suggests that 45, the effective number of macronuclear gene copies previously inferred from the segregation rate, indeed represents the actual number of copies. This conclusion, coupled with previously available evidence that the macronucleus is approximately 45-ploid, suggests that the segregating genetic units in the macronucleus are in effect haploid. This appears to remove the need to postulate inter-allelic repression to account for the phenomenon of phenotypic assortment. Our results, as well as those of others, also are inconsistent with any simple form of the master-slave hypothesis of Allen and Gibson.
TL;DR: A variety of novel transducing lines of phage λ can be obtained by induction of a mixed culture of abnormal lysogens made by mass lysogenization of a host lacking the normal prophage attachment site.
Abstract: A variety of novel transducing lines of phage λ can be obtained by induction of a mixed culture of abnormal lysogens. Such a culture is simply made by mass lysogenization of a host lacking the normal prophage attachment site.
TL;DR: K-Ar age measurements on 19 volcanic rocks from Rurutu, Mangaia, Rarotonga, and Aitutaki in the Cook-Austral chain do not show a systematic increase in the age of the volcanoes to the west-northwest away from Macdonald Seamount as predicted by the melting-spot hypothesis and suggested by geomorphic evidence as mentioned in this paper.
Abstract: K-Ar age measurements on 19 volcanic rocks from Rurutu, Mangaia, Rarotonga, and Aitutaki in the Cook-Austral chain do not show a systematic increase in the age of the volcanoes to the west-northwest away from Macdonald Seamount as predicted by the melting-spot hypothesis and suggested by geomorphic evidence. Ages determined for alkalic basalt samples from Rurutu range from 1.02 to 1.09 m.y., for Mangaia from 16.6 to 18.9 m.y., and for Aitutaki from 0.66 to 0.77 m.y. Two distinct periods of volcanism on Rarotonga were dated at 1.8 and 1.2 m.y. B.P. The relation between the dated units and the main shield-building stage of these volcanoes is uncertain and will remain so until better data on the eruption history and mode of formation of volcanoes in the chain are available.
TL;DR: In this article, the average dipole orientation (ADO) theory of ion-polar molecule capture collisions is reformulated in terms of the average cosine, cos θ.
TL;DR: Altering in adrenalsympathico function were indicated by increased levels of cortisol, epinephrine, and norepinephrine and water and electrolyte balance was not sufficient to maintain body weight, the runners losing approximately 2.8 kg.
Abstract: Adrenal-sympathico function, blood carbohydrates and lipids, and water and electrolyte balance were studied in six highly trained male marathon runners prior to and after running a marathon (26.2 miles; 42.2 km) and on control days corresponding to the above times. Fluid intake was not sufficient to maintain body weight, the runners losing approximately 2.8 kg. Estimated plasma volume losses (161 ml, 4.4%) indicated that most of the fluid loss was extravascular. Tre rose an average 2.4 degrees C and a significant negative correlation between running time and rise in Tre was observed. Glucose, fatty acids, glycerol, hemoglobin, and plasma proteins were significantly elevated after the race. Small but statistically significant increments in lactate and pyruvate were also observed. Alterations in adrenal-sympathico function were indicated by increased levels of cortisol, epinephrine, and norepinephrine.
TL;DR: In this paper, the curvatures of a simple mechanical system relative to a total energy value h were studied in the setting of Riemannian geometry, where the Jacobi metric is defined relative to the energy value.
TL;DR: The electron-phonon interaction for a paramagnetic impurity in an insulating crystal is derived and from that an electron-electron interaction in a higher order is considered as mentioned in this paper.
TL;DR: The relatively thin glacial deposits of Pakistan and India are dated by microfloras and invertebrate faunas as being within the range Stephanian-Sakmarian as mentioned in this paper.
Abstract: Occurrences of glacial deposits of late Paleozoic age in the Northern Hemisphere are known only in peninsular India, along the Himalayan trend from the Salt Range in Pakistan to Sikkim and Bhutan, and there are possible deposits rafted by shore ice in Siberia. The relatively thin glacial deposits of Pakistan and India are dated by microfloras and invertebrate faunas as being within the range Stephanian-Sakmarian. Deposition was from sizable although not enormous ice bodies scattered between the south-central peninsula and the shores of the Tethys Sea, somewhere near the present position of the Himalayas. Ice possibly reached the sea in the region of the Salt Range and in the Kumaon Himalayas. Rock paleomagnetism studies indicate that most of India and Pakistan would have been positioned at paleolatitudes between 40° and 50° S.; global temperatures thus probably were lower than at present. The rafted deposits of Siberia probably accumulated in paleolatitudes between about 50° and 60° N., and being Kazanian in age, they postdated most Gondwanaland tillite deposition (Westphalian to Sakmarian) but were approximately contemporaneous with ice-rafted deposits of southeastern Australia.
TL;DR: Common electromorph frequencies found throughout the ranges of species with large population sizes are interpreted as being a uniquely electrophoretic phenomenon; band patterns on starch and acrylamide gels are phenotypes, not genotypes.
Abstract: A new deterministic formulation is derived of the equilibrium between mutation and natural selection, which takes into account (a) the possibility of many allelic mutation states, (b) selection coefficients of the order of magnitude of the mutation rate and (c) the possibility of further mutation of already mutant alleles. The frequencies of classes of alleles 0, 1, 2, n mutant steps removed from the type allele are shown to form a Poisson distribution, with a mean and variance of the mutation rate divided by the coefficient of selection against each incremental mutational step. — This formulation is interpreted in terms of the expected frequencies of electromorphs , defined as classes of alleles characterized by common electrophoretic mobilities of their protein products. Electromorph frequencies are predicted to form stable unimodal distributions of relatively few phenotypic classes. Common electromorph frequencies found throughout the ranges of species with large population sizes are interpreted as being a uniquely electrophoretic phenomenon; band patterns on starch and acrylamide gels are phenotypes, not genotypes. It is predicted that individual electromorphs are highly heterogeneous with regard to amino acid sequence.
TL;DR: Electron microscopic observations suggest that the rodlike and conelike photoreceptors of diurnal tree squirrels shed outer segment discs.
Abstract: Electron microscopic observations suggest that the rodlike and conelike photoreceptors of diurnal tree squirrels shed outer segment discs. Twenty-four hours after injection of triated L-leucine, the rodlike photoreceptors show a band of radioactivity at the base of the outer segment. The conelike photoreceptor outer segments show only a pattern of diffuse labeling. These results strongly suggest that disc shedding can occur in photoreceptor outer segments in which proteins are diffusely renewed.
TL;DR: In this paper, the average quadrupole orientation (AQO) theory was developed for molecules that belong to the D X point group, which utilizes a framework similar to the ADO theory developed previously.