The structures of the glia and of the synapses in the sympathetic chain of man

Del Rio Hortega teilte die Glia der sympathischen und spinalen Ganglien in 2 Gruppen ein: 1. die perisomatische Glia, welche das Perikaryon der Parenchymzellen mit 2 übereinandergelagerten Schichten umgibt und 2. periaxonale Glia (Spirocyten), welche die Fortsätze der Ganglienzellen versorgt.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47693/1/441_2004_Article_BF00325875.pd

Comparison of Statistical Multifragmentation Model simulations with Canonical Thermodynamical Model results: a few representative cases

The statistical multifragmentation model (SMM) has been widely used to explain experimental data of intermediate energy heavy ion collisions. A later entrant in the field is the canonical thermodynamic model (CTM) which is also being used to fit experimental data. The basic physics of both the models is the same, namely that fragments are produced according to their statistical weights in the available phase space. However, they are based on different statistical ensembles, and the methods of calculation are different: while the SMM uses Monte-Carlo simulations, the CTM solves recursion relations. In this paper we compare the predictions of the two models for a few representative cases

Die Struktur der Synapsen im Nucleus dentatus des Menschen

The knowledge of the morphology of the synapse in the dentate nucleus is limited to the work of Cajal , who described the afferent fibers but not their end-formations. A. Jakob also described the afferent fibers in man with the Golgi method but was no more successful than Cajal . In this contribution the nature of the synapse was investigated with the unreduced variant of the silver carbonate technique of del Rio Hortega . The afferent fibers from the amiculum surround the neurons and their processes with a complicated network of fibers which contains numerous endbulbs and rings and form small plexus. There are three types of end-formations: a) those with an accentuation of the afferent fibers around the proximal segments of the dendrites; b) those with approximately even distribution of the afferent fibers around the pericaryon and the dendrites; c) those with numerous baskets which surround the processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47692/1/441_2004_Article_BF00345077.pd

Scaling in the Lattice Gas Model

A good quality scaling of the cluster size distributions is obtained for the Lattice Gas Model using the Fisher's ansatz for the scaling function. This scaling identifies a pseudo-critical line in the phase diagram of the model that spans the whole (subcritical to supercritical) density range. The independent cluster hypothesis of the Fisher approach is shown to describe correctly the thermodynamics of the lattice only far away from the critical point.Comment: 4 pages, 3 figure

Tracking the phase-transition energy in disassembly of hot nuclei

In efforts to determine phase transitions in the disintegration of highly excited heavy nuclei, a popular practice is to parametrise the yields of isotopes as a function of temperature in the form $Y(z)=z^{-\tau}f(z^{\sigma}(T-T_0))$, where $Y(z)$'s are the measured yields and $\tau, \sigma$ and $T_0$ are fitted to the yields. Here $T_0$ would be interpreted as the phase transition temperature. For finite systems such as those obtained in nuclear collisions, this parametrisation is only approximate and hence allows for extraction of $T_0$ in more than one way. In this work we look in detail at how values of $T_0$ differ, depending on methods of extraction. It should be mentioned that for finite systems, this approximate parametrisation works not only at the critical point, but also for first order phase transitions (at least in some models). Thus the approximate fit is no guarantee that one is seeing a critical phenomenon. A different but more conventional search for the nuclear phase transition would look for a maximum in the specific heat as a function of temperature $T_2$. In this case $T_2$ is interpreted as the phase transition temperature. Ideally $T_0$ and $T_2$ would coincide. We invesigate this possibility, both in theory and from the ISiS data, performing both canonical ($T$) and microcanonical ($e=E^*/A$) calculations. Although more than one value of $T_0$ can be extracted from the approximate parmetrisation, the work here points to the best value from among the choices. Several interesting results, seen in theoretical calculations, are borne out in experiment.Comment: Revtex, 10 pages including 8 figures and 2 table

Critical Temperature for the Nuclear Liquid-Gas Phase Transition

The charge distribution of the intermediate mass fragments produced in p (8.1 GeV) + Au collisions is analyzed in the framework of the statistical multifragmentation model with the critical temperature for the nuclear liquid-gas phase transition $T_c$ as a free parameter. It is found that $T_c=20\pm3$ MeV (90% CL).Comment: 4 pages, 3 figures, published in Phys. Rev.