Genetic studies of quantitative variation in a component of human saliva

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66392/1/j.1469-1809.1963.tb01529.x.pd

MATERNAL RADIATION AND MONGOLISM

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32318/1/0000386.pd

Observing the QuantumBehavior of Light in an Undergraduate Laboratory

While the classical, wavelike behavior of light (interference and diffraction) has been easily observed in undergraduate laboratories for many years, explicit observation of the quantum nature of light (i.e., photons) is much more difficult. For example, while well-known phenomena such as the photoelectric effect and Compton scattering strongly suggest the existence of photons, they are not definitive proof of their existence. Here we present an experiment, suitable for an undergraduate laboratory, that unequivocally demonstrates the quantum nature of light. Spontaneously downconverted light is incident on a beamsplitter and the outputs are monitored with single-photon counting detectors. We observe a near absence of coincidence counts between the two detectors—a result inconsistent with a classical wave model of light, but consistent with a quantum description in which individual photons are incident on the beamsplitter. More explicitly, we measured the degree of second-order coherence between the outputs to be g(2)(0)=0.0177±0.0026,g(2)(0)=0.0177±0.0026, which violates the classical inequality g(2)(0)⩾1g(2)(0)⩾1 by 377 standard deviations

The frequency in Japanese of genetic variants of 22 proteins: V. Summary and comparison with data on Caucasians from the British Isles

The frequencies in Hiroshima and Nagasaki of rare variants (represented in less than 2 % of the individuals surveyed) is summarized for a series of 22 proteins (25 polypeptides). The average number of persons examined for each protein was 3312. There are three pairs of homologous proteins in the series: PGM, and PGM, CA I and CA 11, and HGB A and A,. Only for the first pair is there a significant difference between the two in the total frequency and number of different kinds of variants; it is suggested this may reflect differences in the mutation rates of the corresponding structural genes. For 23 of these polypeptides, comparable data are available for British Caucasians. The average frequency of variants for loci in common in the two series is 2.0/1000 person determinations for Japanese and 1.6/1000 for Caucasoids. At two loci (PGMl and PHI) there were significantly more variants in Japanese than in British; these two loci account for the greater average frequency of variants in Japanese. However, a conservative comparison of number of diflerent variants (electromorphs) encountered, using the 0 statistic of Ewens (1972), yields no significant difference for any of the 22 possible contrasts. The potential usefulness of data of this type in reaching conclusions regarding comparability of mutation rates in two populations is discussed. For the present, the fact that one electromorph may shelter multiple different amino acid substitutions in a protein limits the inferences to be drawn from such contrasts. It is 8 pleasure to acknowledge our indebtedness to Dr Peter Smouse and Dr Warren Ewens for statistical consultations, but responsibility for the tentative interpretations is entirely our own.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66201/1/j.1469-1809.1978.tb00913.x.pd

Inherited electrophoretic variants detected in a Japanese population with two-dimensional gels of erythrocyte lysates

Genetic variation has been studied in erythrocyte lysates from 100 Japanese children and their parents by means of two-dimensional polyacrylamide gel electrophoresis. Fifty-five polypeptides selected without respect to variability were considered suitable for scoring. Genetic variation was encountered in 14 of these polypeptides. Family data show that the segregation of 13 variants is consistent with an autosomal codominant mode of inheritance; the remaining variant exhibits a sex-linked mode of inheritance. Of 8 presumably identical polypeptides found variable in Japanese and/or Caucasians, differences in the occurrence or allele frequencies of polymorphisms were recognized for four. Contrary to the experience of some investigators, the amount of variation and the ethnic differences we are encountering indicate that two-dimensional polyacrylamide gel electrophoresis is a sensitive tool for the study of genetic events.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65555/1/j.1469-1809.1986.tb01753.x.pd

Genetic Polymorphism in Evolving Population

We present a model for evolving population which maintains genetic polymorphism. By introducing random mutation in the model population at a constant rate, we observe that the population does not become extinct but survives, keeping diversity in the gene pool under abrupt environmental changes. The model provides reasonable estimates for the proportions of polymorphic and heterozygous loci and for the mutation rate, as observed in nature

Frequency and distribution of rare electrophoretic mobility variants in a population of human newborns in Ann Arbor, Michigan

We have summarized the frequency and distribution of the rare variants encountered during the screening of 258 815 allele products, the products of 51 different loci, in 3242 predominantly Caucasian (88 %) newborns. Seventy-nine different rare variants, representing 187 occurrences, were identified. Almost 60 % (46 of 79) of the rare variants occurred as singletons while another 20 % were seen in two unrelated individuals. No rare variants were detected at 18 loci while no variants, either rare or polymorphic, were detected at 14 loci. More rare variants were identified at loci that were classified as polymorphic and also at loci where the gene products exist as a monomer. A positive relationship was observed between variant frequency, either classes or copies, and subunit molecular mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65173/1/j.1469-1809.1987.tb01065.x.pd

Towards the theory of ferrimagnetism

Two-sublattice ferrimagnet, with spin-$s_1$ operators $\bf{S_{1i}}$ at the sublattice $A$ site and spin-$s_2$ operators $\bf{S_{2i}}$ at the sublattice $B$ site, is considered. The magnon of the system, the transversal fluctuation of the total magnetization, is a complicate mixture of the transversal fluctuations of the sublattice $A$ and $B$ spins. As a result, the magnons' fluctuations suppress in a different way the magnetic orders of the $A$ and $B$ sublattices and one obtains two phases. At low temperature $(0,T^*)$ the magnetic orders of the $A$ and $B$ spins contribute to the magnetization of the system, while at the high temperature $(T^*,T_N)$, the magnetic order of the spins with a weaker intra-sublattice exchange is suppressed by magnon fluctuations, and only the spins with stronger intra-sublattice exchange has non-zero spontaneous magnetization. The $T^*$ transition is a transition between two spin-ordered phases in contrast to the transition from spin-ordered state to disordered state ($T_N$-transition). There is no additional symmetry breaking, and the Goldstone boson has a ferromagnetic dispersion in both phases. A modified spin-wave theory is developed to describe the two phases. All known Neel's anomalous $M(T)$ curves are reproduced, in particular that with "compensation point". The theoretical curves are compared with experimental ones for sulpho-spinel $MnCr2S_{4-x}Se_{x}$ and rare earth iron garnets.Comment: 9 pages, 8 figure

The frequency in Japanese of genetic variants of 22 proteins

This paper presents the results of an electrophoretic survey of approximately 4000 individuals from the cities of Hiroshima and Nagasaki, Japan, for four serum proteins: albumin, ceruloplasmin, haptoglobin and transferrin. The haptoglobin gene frequencies obtained for the HP 1 -HP 2 polymorphism are in agreement with earlier reports. Rare electrophoretic variants of albumin, ceruloplasmin and haptoglobin occur with frequencies of 2.48, 0.50 and 0.58 per 1000 determinations, respectively. The noteworthy finding of 8 distinct transferrin variants in these populations, with a combined frequency of 20.90 per 1000 determinations, is also presented. Four of these variants (D Ch1 , B 1 , B 3 and D hir2 which corresponds electrophoretically to D 4 ) have been reported in other populations in Japan, but the other five have not previously been differentiated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66399/1/j.1469-1809.1977.tb01859.x.pd