The SCR flare of 16 February 1984 as recorded by the Sayan spectrograph

The Sayan cosmic ray (CR) spectrograph recorded an SCR flare that occurred on 16 February 1984. Data from both 1-hour and 110-minute duration measurements in 10 channels with different energy sensitivity (of neutron monitors HM-64 located at different depths in the atmosphere, and of a neutron, multiple neutron and rigid mumeson component lead-less detector) is presented. The parameters of the SCR variation spectrum are evaluated and it is shown that the recording of multiple neutrons at the same geographic point and at the same level in the atmosphere provides information similar to that from a spectrographic complex of instruments

Hamiltonian dynamics and constrained variational calculus: continuous and discrete settings

The aim of this paper is to study the relationship between Hamiltonian dynamics and constrained variational calculus. We describe both using the notion of Lagrangian submanifolds of convenient symplectic manifolds and using the so-called Tulczyjew's triples. The results are also extended to the case of discrete dynamics and nonholonomic mechanics. Interesting applications to geometrical integration of Hamiltonian systems are obtained.Comment: 33 page

The Possible "Proton Sponge " Effect of Polyethylenimine (PEI) Does Not Include Change in Lysosomal pH.

Polycations such as polyethylenimine (PEI) are used in many novel nonviral vector designs and there are continuous efforts to increase our mechanistic understanding of their interactions with cells. Even so, the mechanism of polyplex escape from the endosomal/lysosomal pathway after internalization is still elusive. The “proton sponge ” hypothesis remains the most generally accepted mechanism, although it is heavily debated. This hypothesis is associated with the large buffering capacity of PEI and other polycations, which has been interpreted to cause an increase in lysosomal pH even though no conclusive proof has been provided. In the present study, we have used a nanoparticle pH sensor that was developed for pH measurements in the endosomal/lysosomal pathway. We have carried out quantitative measurements of lysosomal pH as a function of PEI content and correlate the results to the “proton sponge ” hypothesis. Our measurements show that PEI does not induce change in lysosomal pH as previously suggested and quantification of PEI concentrations in lysosomes makes it uncertain that the “proton sponge ” effect is the dominant mechanism of polyplex escape

Quaternion Solution for the Rock'n'roller: Box Orbits, Loop Orbits and Recession

We consider two types of trajectories found in a wide range of mechanical systems, viz. box orbits and loop orbits. We elucidate the dynamics of these orbits in the simple context of a perturbed harmonic oscillator in two dimensions. We then examine the small-amplitude motion of a rigid body, the rock'n'roller, a sphere with eccentric distribution of mass. The equations of motion are expressed in quaternionic form and a complete analytical solution is obtained. Both types of orbit, boxes and loops, are found, the particular form depending on the initial conditions. We interpret the motion in terms of epi-elliptic orbits. The phenomenon of recession, or reversal of precession, is associated with box orbits. The small-amplitude solutions for the symmetric case, or Routh sphere, are expressed explicitly in terms of epicycles; there is no recession in this case

Beeinflussung der Vorderkantenablösung durch akustische Anregung

Der Einfluß akustischer Anregung auf die Grenzschichtablösung von einem Flügel endlicher Spannweite wurde mittels Strömungssichtbarmachung untersucht. Ein Flügelmodell mit einer Streckung Spannweite: Flügeltiefe = 3 wurde im Bereich 0 < Ma < 0,1 und 6 x 10 hoch 5 < Re < 1.2 x 10 hoch 6 bei Anstellwinkeln bis zu 25 und Schiebewinkeln bis zu 30 getestet. Die Wirkungen sphärischer Schallwellen von einer Punktschallquelle im Fernfeld sowie der durch einen Hohlspiegel gebündelten Bestrahlung einer Teilfläche des Flügels wurden untersucht. Die Versuchsergebnisse zeigen, daß durch Schallanregung mit geeigneter Frequenz die bei hohen Anstellwinkeln auftretende Strömungsablösung an der Flügelvorderkante zu einer turbulenten Ablösung nahe der Flügelmitte umgewandelt und damit das abgelöste Gebiet stark verkleinert wird

HYBRID REVASCULIZATION AS METHOD OF SURGICAL TREATMENT OF ISCHEMIC CORONARY DISEASE IN NUMEROUS LESIONS OF CORONARY BED

Hybrid revasculization of myocardium combined the advantages of mammary-coronary bypass surgery and coronary arteries stenting. It presented itself as a perspective direction in treatment of ischemic coronary disease. The article provides the results of comparison of usage of hybrid revasculization of myocardium and aortocoronary bypass in 71 patients with multivessel coronary artery disease. The data obtained indicated, that hybrid approach allowed complete revasculization of the myocardium (as in case of aortocoronary bypass), fast recovery of the patient, shortening a hospital stay due to decrease of intra- and postoperative complications

Distribution and ecology of Chaenocephalus aceratus (Channichthyidae) around South Georgia and Shag Rocks (Southern Ocean)

Chaenocephalus aceratus (Family Channicthyidae) is one of the dominant species of demersal fish living on the South Georgia shelf where it is caught in low numbers as by-catch in the mackerel icefish and Antarctic krill commercial fisheries. Data collected during 14 demersal fish surveys, from 1986 to 2006, are analysed to investigate biomass, distribution, growth and diet. Biomass estimates from a swept area method ranged from 4,462 to 28,740 tonnes on the South Georgia and Shag Rock shelves although few fish were caught at Shag Rocks. Analysis of length frequency data indicated that growth was fast in the first five years with males and females attaining lengths at first spawning of 440 mm TL and 520 mm TL. The diet was comprised of fish and crustaceans, with an ontogenetic shift in diet from Euphausia superba and mysids to benthic fish and decapods observed to begin at 250 mm TL. In larger fish (>500 mm TL) the diet was dominated by fish. C. aceratus diet is sufficiently different from the other species of channichthyids around South Georgia to suggest that these species have undergone resource partitioning

Changing stone composition profile of children with nephrolithiasis

Objective: To determine if this trend toward calcium phosphate stone formation exists in children. Methods: This is a retrospective study of medical records of 179 children managed at our medical center from 1992-2010 for whom stone analysis and other pertinent laboratory data were available. A comparison of patients managed from 1992-2000 (P1) and 2001-2010 (P2) was undertaken. Statistical analysis included nonparametric tests. Results: There were no significant differences in the mean age of the 2 cohorts. During both periods, boys comprised a significantly higher proportion during the first decade of life, whereas girls comprised a significantly higher proportion during the second decade. A higher percentage of patients had calcium oxalate (CaOx) stones in P1 compared to P2 (60% vs 47%, P =.0019). There was a significant increase in the percentage of patients having calcium phosphate stones in P2 compared to P1 (27% vs 18.5%, P =.008). Twenty-seven patients had recurrent stones. A comparison of the compositions of the first and last stones of patients within this group demonstrated an increasing proportion of brushite stones (3.7% vs 11.1%, P =.04). Twenty-four hour urine testing results were similar for those with CaOx and calcium phosphate stones. Conclusion: An increasing proportion of children have calcium phosphate calculi. Brushite stones are more prevalent in children with recurrent stone events. The impetus of these shifts is not readily apparent. © 2013 Elsevier Inc. All Rights Reserved