Manifold dimension of a causal set: Tests in conformally flat spacetimes

This paper describes an approach that uses flat-spacetime dimension estimators to estimate the manifold dimension of causal sets that can be faithfully embedded into curved spacetimes. The approach is invariant under coarse graining and can be implemented independently of any specific curved spacetime. Results are given based on causal sets generated by random sprinklings into conformally flat spacetimes in 2, 3, and 4 dimensions, as well as one generated by a percolation dynamics.Comment: 8 pages, 8 figure

Spin entanglement, decoherence and Bohm's EPR paradox

We obtain criteria for entanglement and the EPR paradox for spin-entangled particles and analyse the effects of decoherence caused by absorption and state purity errors. For a two qubit photonic state, entanglement can occur for all transmission efficiencies. In this case, the state preparation purity must be above a threshold value. However, Bohm’s spin EPR paradox can be achieved only above a critical level of loss. We calculate a required efficiency of 58%, which appears achievable with current quantum optical technologies. For a macroscopic number of particles prepared in a correlated state, spin entanglement and the EPR paradox can be demonstrated using our criteria for efficiencies η > 1/3 and η > 2/3 respectively. This indicates a surprising insensitivity to loss decoherence, in a macroscopic system of ultra-cold atoms or photons

Metabolomic study of the LDL receptor null mouse fed a high-fat diet reveals profound perturbations in choline metabolism that are shared with ApoE null mice

Failure to express or expression of dysfunctional low-density lipoprotein receptors (LDLR) causes familial hypercholesterolemia in humans, a disease characterized by elevated blood cholesterol concentrations, xanthomas, and coronary heart disease, providing compelling evidence that high blood cholesterol concentrations cause atherosclerosis. In this study, we used 1H nuclear magnetic resonance spectroscopy to examine the metabolic profiles of plasma and urine from the LDLR knockout mice. Consistent with previous studies, these mice developed hypercholesterolemia and atherosclerosis when fed a high-fat/cholesterol/cholate-containing diet. In addition, multivariate statistical analysis of the metabolomic data highlighted significant differences in tricarboxylic acid cycle and fatty acid metabolism, as a result of high-fat/cholesterol diet feeding. Our metabolomic study also demonstrates that the effect of high-fat/cholesterol/cholate diet, LDLR gene deficiency, and the diet-genotype interaction caused a significant perturbation in choline metabolism, notably the choline oxidation pathway. Specifically, the loss in the LDLR caused a marked reduction in the urinary excretion of betaine and dimethylglycine, especially when the mice are fed a high-fat/cholesterol/cholate diet. Furthermore, as we demonstrate that these metabolic changes are comparable with those detected in ApoE knockout mice fed the same high-fat/cholesterol/cholate diet they may be useful for monitoring the onset of atherosclerosis across animal models

Research notes: A partially male-sterile mutant in soybeans

An entry consisting mostly of plants having little to no seed set was found amidst the breeding material of Dr. Walter R. Fehr (Iowa State University) in 1975. The entry was descendent from germplasm population AP6(Sl)Cl, which was described by Fehr and Ortiz (1975). Investigations have revealed that partial male sterility was the primary cause leading to reduced seed set (Stelly, 1979)

Research Notes : The T270H chlorotic mutant: Inheritance and linkage analysis

An unusual chlorotic mutant that is variably viable was found in 1977. Preliminary inheritance data and phenotypes of the mutant were described by Stelly, Muir and Palmer in 1979. Combined F2 plant and F3 family analyses suggested monogenic recessive inheritance of the chlorotic phenotype

Research notes: Seed coats of Glycine soja and G. gracilis --inheritance of color/pattern

In the preceding note, it was mentioned that the derivation of an abnormally short chromosome involved natural cross-pollination of a partially malesterile (msp msp) plant (A76-517-2) by pollen from G. soja, G. gracilis , or an introgression product of these species into G. max. The recessive allele for self seed coat color (i) and the allele(s) producing the dark seed coat pattern of G. soja and G.-gracilis were concomitantly transferred in the cross-pollination. Segregation in later generations and a few testcrosses indicate that the characteristically patterned seed coats of G. soja and G. gracilis are governed by an allele of the R locus; the allele appears to be dominant to r (brown), r^m (ring-pattern) and, perhaps, to R (black)

Research notes: Inheritance and expression of a mutant phenotype affecting the number of petals per flower

Plants of the Glycine max Plant Introduction 68,704 characteristically produce flowers that have six or more petals, rather than the nonnal complement of five petals (l standard, 2 wing, and 2 keel petals). We have investigated the inheritance and expression of this trait. Eight F1 plants were classified by sampling ten flowers per plant; none of the F1 plants produced more than five petals, indicating that the phenotype is under recessive genetic control

Experimental tests of reaction rate theory: Mu+H2 and Mu+D2

Copyright @ 1987 American Institute of Physics.Bimolecular rate constants for the thermal chemical reactions of muonium (Mu) with hydrogen and deuterium—Mu+H2→MuH+H and Mu+D2→MuD+D—over the temperature range 473–843 K are reported. The Arrhenius parameters and 1σ uncertainties for the H2 reaction are log A (cm3 molecule-1 s-1)=-9.605±0.074 and Ea =13.29±0.22 kcal mol-1, while for D2 the values are -9.67±0.12 and 14.73±0.40, respectively. These results are significantly more precise than those reported earlier by Garner et al. For the Mu reaction with H2 our results are in excellent agreement with the 3D quantum mechanical calculations of Schatz on the Liu–Siegbahn–Truhlar–Horowitz potential surface, but the data for both reactions compare less favorably with variational transition-state theory, particularly at the lower temperatures.NSERC (Canada) and the Petroleum Research Foundation of the Americal Chemical Society