Precession Intuitively Explained

Formal explanations of the dynamics of free and heavy tops are considered to be known for centuries. However, intuitive understanding of their unexpected behavior is still a challenge. In this paper, we present elementary force based explanations of precession of heavy symmetric tops, derived in inertial and non-inertial reference frames. Simple calculations are enabled by a model equivalent to a spinning top, namely a square-formed tube carrying a streaming ideal fluid or a frictionless chain. Precession in a combined, gravitational and magnetic field is also discussed

Inhibition of anaphylactic shock by gadolinium chloride-induced Kupffer cell blockade.

Data in the literature concerning the role of macrophages in anaphylaxis are contradictory. In the present study, the effect of macrophage blockade induced by gadolinium chloride (GdCl3) on anaphylactic shock is investigated. Our observations show that GdCl3 prevents lethal anaphylactic shock in mice sensitized to ovalbumin. Gadolinium chloride given i.v. in a dose of 1 mg/100 g body weight 24 or 48 h before the elicitation of anaphylactic shock resulted in 80% survival, compared with the 43% survival in the control group. The same dose of this rare-earth metal salt also greatly reduced the mortality in mice sensitized with ovalbumin containing Bordetella pertussis vaccine, and similarly abrogated the symptoms of anaphylaxis, including the accumulation of serotonin and histamine in the liver. The results suggest that macrophages play an important role in mouse anaphylaxis

Comparison of Raspberry bushy dwarf virus isolates from Hungary and Slovenia

In 2006 and 2007 samples of grapevine and Rubus species were collected and analysed by DAS-ELISA to survey the presence of Raspberry bushy dwarf virus (RBDV) in Slovenia and Hungary. Seven varieties of raspberry from one Hungarian collection orchard were found to be infected. In Slovenia the presence of RBDV was confirmed only in three samples of wild Rubus. None of the 133 samples from different locations in Hungary proved to be infected with RBDV, although this virus is found to be widely distributed in grapevine in neighbouring Slovenia. Serological characterisation with three monoclonal antibodies (R2, R5 and D1) was performed on positive samples. Selected positive samples were partially sequenced. The results of serological and molecular analyses were compared with the analyses of raspberry and grapevine isolates obtained in Slovenia from other projects and published RBDV sequences from the GeneBank database to study the variability among hosts and locations. Isolates from grapevine grouped separately from the black raspberry isolate and all the red raspberry isolates. RBDV isolates from Hungarian samples formed a subgroup within red and black raspberry group.Keywords: RBDV, variability, Rubus, raspberry, grapevine, sequences, monoclonal antibodie

Nonideal particle distributions from kinetic freeze-out models

In fluid dynamical models the freeze-out of particles across a three-dimensional space-time hypersurface is discussed. The calculation of final momentum distribution of emitted particles is described for freeze-out surfaces, with both spacelike and timelike normals, taking into account conservation laws across the freeze-out discontinuity