Virial theorem for an inhomogeneous medium, boundary conditions for the wave functions, and stress tensor in quantum statistics.

On the basis of the stationary Schrödinger equation, the virial theorem in an inhomogeneous external field for the canonical ensemble is proved. It is shown that the difference in the form of virial theorem is conditioned by the value of the wave-function derivative on the surface of the volume, surrounding the system under consideration. The stress tensor in such a system is determined by the average values of the wave-function space derivatives.

Diffusion in a time-dependent external field.

The problem of diffusion in a time-dependent (and generally inhomogeneous) external field is considered on the basis of a generalized master equation with two times, introduced by Trigger and co-authors [S. A. Trigger, G. J. F. van Heijst, and P. P. J. M. Schram, Physica A 347, 77 (2005); J. Phys.: Conf. Ser. 11, 37 (2005)]. We consider the case of the quasi-Fokker-Planck approximation, when the probability transition function for diffusion (PTD function) does not possess a long tail in coordinate space and can be expanded as a function of instantaneous displacements. The more complicated case of long tails in the PTD will be discussed separately. We also discuss diffusion on the basis of hydrodynamic and kinetic equations and show the validity of the phenomenological approach. A type of "collision" integral is introduced for the description of diffusion in a system of particles, which can transfer from a moving state to the rest state (with some waiting time distribution). The solution of the appropriate kinetic equation in the external field also confirms the phenomenological approach of the generalized master equation.

Cerebral white matter abnormalities in 6p25 deletion syndrome.

Submicroscopic deletion of the terminal part of the short arm of chromosome 6, including 6p25, leads to developmental retardation, hearing impairment, ocular dysgenesis, and dysmorphic features. We diagnosed 3 patients referred because of white matter abnormalities of unknown origin. MR imaging showed multifocal areas of abnormal signal and enlarged perivascular spaces in the cerebral white matter that were stable during follow-up. Multifocal white matter abnormalities are most commonly seen in static, nonmetabolic encephalopathies, including chromosomal abnormalities.

Kinetic theory of Jeans instability.

Kinetic treatment of the Jeans gravitational instability, with collisions taken into account, is presented. The initial-value problem for the distribution function which obeys the kinetic equation, with the collision integral conserving the number of particles, is solved. Dispersion relation is obtained and analyzed. New modes are found. Collisions are shown not to affect the Jeans instability criterion. Although the instability growth rate diminishes, the collisions they cannot quench the instability. However, the oscillation spectrum is modified significantly: even in the neighborhood of the threshold frequency omega=0 (separating stable and unstable modes) the spectrum of oscillations can strongly depend on the collision frequency. Propagating (rather than aperiodic) modes are also found. These modes, however, are strongly damped.

Statistical theory of dusty plasmas: microscopic equations and Bogolyubov-Born-Green-Kirkwood-Yvon hierarchy.

Basic principles of statistical theory of dusty plasmas are formulated with regard for electron and ion absorption by dust particles. Rigorous microscopic equations are introduced and employed to derive the BBGKY hierarchy and kinetic equations. The charging processes are shown to induce a considerable modification of both microscopic and kinetic equations for plasma particles and grains. In the approximation of dominant influence of charging collisions, explicit kinetic equations are derived and applied to calculate stationary distributions of grain velocities and charges.

Nonhomogeneity of dusty crystals and plasma diagnostics.

Real dusty crystals are inhomogeneous due to the presence of external forces. We suggest approximations for calculations of different types of inhomogeneous dust crystals (DC's) (chain and DC's with a few slabs) in the equilibrium state. The results are in a good agreement with experimental results and can be used as an effective diagnostic method for many dusty systems.

No evidence of mutations in the genes for type I and type II 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) in nonclassical 3 beta HSD deficiency.

Nonclassical 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase deficiency (NC3 beta HSDD) has been diagnosed in hyperandrogenic women with an increasing frequency during the last 14 yr. Fifteen menarcheal women with androgen excess syndrome, diagnosed with NC3 beta HSDD previously were restudied, in 12 after discontinuation of glucocorticoid treatment, in 2 patients never treated with glucocorticoids, and in 1 both before and after glucocorticoid therapy. Each of the 15 patients underwent ACTH stimulation testing, in some cases on multiple occasions. Although some (very few) patients seem to have improved with time, others remained the same or got worse. Molecular DNA analysis was also performed in 6 of the patients, using the strategy successfully used to detect point mutations in the type II 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) gene, which are responsible for classical 3 beta HSD deficiency. This strategy consists of the direct sequencing of polymerase chain reaction-amplified DNA fragments corresponding to the complete coding sequence and all intron-exon junctions and to the 5'- and 3'-noncoding region of this gene. We were unable to demonstrate any mutation of the type II 3 beta HSD gene in these 6 patients. To gain additional information about potential mutations, direct sequencing of the type I 3 beta HSD gene was also performed using this same strategy, and no mutations were found. The present study strongly suggests that unlike the salt-losing and nonsalt-losing forms of classical 3 beta HSD deficiency, NC3 beta HSDD is not due to a mutant type II 3 beta HSD enzyme. However, the possibility remains of a mutation(s) in the unsequenced regions of the type II 3 beta HSD gene or elsewhere, such as in a gene for modulatory protein, playing a specific role in the expression of the type II 3 beta HSD gene. On the other hand, knowing the multiple hormonal controls to which 3 beta HSD activity is subject, it cannot be excluded that at least in some cases, NC3 beta HSDD may be an acquired defect, the result of endogenous or environmental factors.

Nonclassical 3 beta-hydroxysteroid dehydrogenase deficiency: a review of our experience with 25 female patients.

OBJECTIVE: To report 15 new menarcheal women affected with nonclassical 3 beta-hydroxysteroid dehydrogenase deficiency (nonclassical 3 beta-HSD) and evaluation of glucocorticoid therapy in treated patients. DESIGN: Diagnosis of these new patients using a standard adrenocorticotropin test. Effects of glucocorticoid therapy on clinical hormonal and sonographic features of each patient are appreciated for periods varying between 4 months and 7 1/2 years. SETTING: All at The New York Hospital-Cornell Medical Center. The Pediatric Endocrinology Ambulatory Service; the Children's Clinical Research Center Core Laboratories; and the Department of Radiology. PATIENTS, PARTICIPANTS: Fifteen menarcheal women (14 to 30 years of age) newly diagnosed and 10 women previously diagnosed were evaluated for symptoms of hyperandrogenism and/or irregular menses. MAIN OUTCOME MEASURE(S): Positive effect of glucocorticoid therapy on signs and symptoms, hormonal levels, and ovarian imaging. RESULTS: Polycystic ovarian syndrome is noted in approximately half the cases. Glucocorticoid treatment greater than 3 months duration results in a reversal of symptoms in most cases.

[Stress in newborn infants: a literature review]. / Stress bij pasgeborenen: een literatuuroverzicht.

All kinds of handling of sick newborn, especially premature babies, are thought to be stressful events. In order to develop stress reducing programs for those infants, a study was carried out into the reports of stress parameters for newborns in the current literature. B-endorphin answers the best to the needs for a reliable parameter in stress studies.