Dynamics of chromosome movement

(1) At mitotic prophase unravelling of the chromosome spiral occurs without actual increase in length.(2) The opening out of the secondary split is at mid -prophase. The actual split most probably does not coincide with the opening out of the sister chromatids during mitosis.(3) The commencement of mitosis is the fission of genes and this must occur during the resting stage.(4) The single structure of prophase spiral at mitosis is due to the close association of the homologous genes, chromomeres, and chromatids. The cause of the association is homology, most probably physicochemical in nature.(5) Unravelling of the chromosome spiral is a condition sine qua non for the building up of the matrix of each chromonema'separately.(6) Contraction operates from the undivided attachment constriction. This force acts upon the matrix, causing it to decrease gradually in length. The chromonema does not shorten but adjusts itself by forming a spiral. This structure can be recognised in the prophase of the following division (persist - ance of chromosome individuality).(7) The tertiary split at metaphase was not found in Vicia, Tulipa and Allium. Anaphase separation is due to repulsion which operates between two homologous attachment constrictions.(8) The loci of pairing at zygotene between homologous chromosomes are at random, but always include groups of chromomeres. Polarisation is caused by special attraction between the ends of chromosomes and centrosomes or nuclear Dole. It is most probably genetical in its or(9) At pachytene the homologous chromosomes twist around each other.(10) The opening out of the secondary split is at the end of pachytene.(11) The general rule of pairing - that association always occurs between pairs of homologues, and repulsion always between pairs of paired homologous constituents, - is demonstrated by several observations.(12) At the end of pachytene, attraction and contraction produce a torsion. The secondary split introduces the repulsion and as a result of the interaction of these forces, breaks occur. The fusion of partner chromatids produces the chiasma.(13) Chiasma frequency is not related to the size of the bivalents.(14) The decrease in the number of chiasmata from diplotene to metaphase is caused by two repulsions . The first is general, operating between pairs of paired chromatids; the second is specific and acts between two corresponding homologous attachment constrictions. If the latter is greater, the result of interaction is movement of the chiasmata, towards the distal end.(15) The following data supply evidence in favour of Janssens' chiasmatype hypothesis: (a) Pairing of unequal chromosomes; (b) Interlocking of bivalents at meiotic pro - :phase. (ç) Twisting of sister chromatids on both sides of chiasmata; (d) Decrease in genetical crossing -over parallel to a similar decrease in chiasma frequency.(16) The terminal association of bivalents depends upon a special affinity between terminal chromomeres. If intercalary chromomeres become terminal by trans - location, they attain this special affinity.(17) The movement of chromosomes towards the equatorial plate is a result of repulsion operating between poles and attachment constrictions only.(18) Metaphase equilibrium is a result of repulsion between poles and attachments and between attachmen of similar and dissimilar chromosomes.(19) In some cases the interal affinity of chromosomes will interact with the other forces and determine the mitotic or meiotic metaphase pattern, as it is the case in secondary association and somatic pairing.(20) The spindle mechanism is necessary for normal chromosome movements before and after metaphase. It guides the chromosomes by their attachment constriction towards equilibrium either at the metaphase plate or at the poles. The spindle can be formed only in a normal cytoplasmic environment.(21) At anaphase there is a second period of equilibrium where the repulsion between the corresponding attachment constrictions and poles is equal. Further separation is due to the expansion of the inter-chromosomal spindle, for which new evidence is put forward.(22) At anaphase there is no repulsion between the similar or dissimilar attachments migrating towards the same pole. Repulsion exists only between the corresponding homologous attachment constrictions.(23) The similarity between effects of forces operating at mitotic and meiotic division and those which act in an electro-magnetic field indicates a close relationship in the nature of those forces

Payne v. Tennessee: The Arbitrary Imposition of the Death Penalty and a Review of Florida Case Law Since: Booth v. Maryland

In Booth v. Maryland,1 the United States Supreme Court decided that evidence relating to a victim\u27s character and the extent of harm caused to the victim\u27s family and community was inadmissible to deter- mine whether a defendant convicted of a capital crime should be put to death. The majority in Booth, while empathizing with the grief of a victim\u27s family, recognized the potential danger such evidence has on a jury to sentence defendants to death based on such arbitrary factors as what kind of person the victim was and the unforeseeable harm the victim\u27s death had on others

Beyond the Spin Model Approximation for Ramsey Spectroscopy

Ramsey spectroscopy has become a powerful technique for probing non-equilibrium dynamics of internal (pseudospin) degrees of freedom of interacting systems. In many theoretical treatments, the key to understanding the dynamics has been to assume the external (motional) degrees of freedom are decoupled from the pseudospin degrees of freedom. Determining the validity of this approximation -- known as the spin model approximation -- is complicated, and has not been addressed in detail. Here we shed light in this direction by calculating Ramsey dynamics exactly for two interacting spin-1/2 particles in a harmonic trap. We focus on $s$-wave-interacting fermions in quasi-one and two-dimensional geometries. We find that in 1D the spin model assumption works well over a wide range of experimentally-relevant conditions, but can fail at time scales longer than those set by the mean interaction energy. Surprisingly, in 2D a modified version of the spin model is exact to first order in the interaction strength. This analysis is important for a correct interpretation of Ramsey spectroscopy and has broad applications ranging from precision measurements to quantum information and to fundamental probes of many-body systems

Dynamic response functions for the Holstein-Hubbard model

We present results on the dynamical correlation functions of the particle-hole symmetric Holstein-Hubbard model at zero temperature, calculated using the dynamical mean field theory which is solved by the numerical renormalization group method. We clarify the competing influences of the electron-electron and electron-phonon interactions particularity at the different metal to insulator transitions. The Coulomb repulsion is found to dominate the behaviour in large parts of the metallic regime. By suppressing charge fluctuations, it effectively decouples electrons from phonons. The phonon propagator shows a characteristic softening near the metal to bipolaronic transition but there is very little softening on the approach to the Mott transition.Comment: 13 pages, 19 figure

Growing Graphs with Hyperedge Replacement Graph Grammars

Discovering the underlying structures present in large real world graphs is a fundamental scientific problem. In this paper we show that a graph's clique tree can be used to extract a hyperedge replacement grammar. If we store an ordering from the extraction process, the extracted graph grammar is guaranteed to generate an isomorphic copy of the original graph. Or, a stochastic application of the graph grammar rules can be used to quickly create random graphs. In experiments on large real world networks, we show that random graphs, generated from extracted graph grammars, exhibit a wide range of properties that are very similar to the original graphs. In addition to graph properties like degree or eigenvector centrality, what a graph "looks like" ultimately depends on small details in local graph substructures that are difficult to define at a global level. We show that our generative graph model is able to preserve these local substructures when generating new graphs and performs well on new and difficult tests of model robustness.Comment: 18 pages, 19 figures, accepted to CIKM 2016 in Indianapolis, I