Face-centred cubic lattices and particle redistribution in vortex methods

In vortex particle methods one is concerned with the problem of clustering and depletion of particles in different regions of the flow. The overlap of the vortex blobs is indeed of primary importance for the convergence of the method. In this paper we consider face-centred cubic (FCC) lattices for particle redistribution in three dimensions. This lattice is in fact the most natural way to pack spheres (the FCC is also known as a closest-sphere packing lattice). As a consequence, a point has 12 equidistant close neighbours rather than six for the cubic lattice. The FCC lattice thus offers some symmetry properties that should prove useful for a number of reasons, e.g., the core overlap issue. A few results for this scheme are presented. The problem of two colliding vortex rings at Re = 250 and 500 is studied with both the FCC and cubic lattice schemes. This problem subjects the vortex tubes to a quite strong stretching field and can amply test the quality of the lattice and the remeshing

Reconnection of Colliding Vortex Rings

We investigate numerically the Navier-Stokes dynamics of reconnecting vortex rings at small Reynolds number for a variety of configurations. We find that reconnections are dissipative due to the smoothing of vorticity gradients at reconnection kinks and to the formation of secondary structures of stretched antiparallel vorticity which transfer kinetic energy to small scales where it is subsequently dissipated efficiently. In addition, the relaxation of the reconnection kinks excites Kelvin waves which due to strong damping are of low wave number and affect directly only large scale properties of the flow

Randomized placebo-controlled cross-over designs in clinical trials : a gold-standard to be reassessed

Placebo effects are well-known phenomena in medicine and biology. In fact, placebos are used as control conditions in randomized cross-over clinical trials to validate new treatments. Only recently, however, has it become apparent that the conditioning and/or expectation effects provided by the experience of placebos can influence the results of clinical trials. It seems that combining shams and sequences has prejudiced the conclusions provided by cross-over designs. Frighteningly, this bias is always in the same direction, namely to increase the risk of rejecting potentially valid treatments. New models for clinical trials should be encouraged if we wish to market new and truly valid treatments

The MAP kinase cascade. A key target for treatments in skin cancerology.

Résumé : Les «Mitogen-Activated Protein Kinases» (MAPK) forment un ensemble coordonné de protéines cellulaires impliquées dans la prolifération, la différenciation, la migration et l’apoptose des cellules. Elles sont particulièrement activées, par certaines cytokines, hormones, le stress environnemental, ainsi que dans des cancers cutanés. Des agents pharmacologiques ciblés contre la cascade MAPK révolutionnent actuellement la cancérologie cutanée, du moins dans une phase transitoire du processus métastatique. Des traitements combinés sont susceptibles d’améliorer la survie médiane.Peer reviewe

Tailoring Stress Waves in 2-D Highly Nonlinear Granular Crystals: Simulations and Experiments

We study the propagation of elastic stress waves in two-dimensional highly nonlin-ear granular crystals composed of square packings of spheres with and without cylindrical intruders, via experiments and numerical simulations. By varying the intruder material, we show the ability to alter the propagating wave front characteristics. Experiments agree well with dis-crete particle simulations

ADH Levels during Salt Depletion in Dogs *

Two groups of trained dogs were subjected to sodium chloride depletion and plasma ADH concentration, renin activity, plasma sodium, plasma osmolality, blood volume, hematocrit and body weight were measured. In one group of animals, sodium depletion was created by restricting intake to 5 mEq/24 h. Despite a statistically significant decrease in body weight and blood volume and a corresponding increase in plasma renin activity, plasma ADH concentration was not seen to change significantly from control values. Similar findings were seen in a second group of dogs which were given a diuretic in addition to dietary sodium restriction. In these animals the decrease in blood volume and rise in plasma renin activity were proportionately greater. Plasma ADH concentration was not observed to change significantly in this group of animals either. Both groups of animals developed significant hyponatremia during the experiment. It is concluded that in these dogs, the secretion of ADH was not suppressed and consequently hyponatremia developed. It is suggested that endogenous angiotensin was responsible for the continued secretion of ADH at control levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75034/1/j.1365-2362.1971.tb00567.x.pd

Reactions of Juvenile Delinquents to "Justified" and "Less Justified" Movie Violence

In order to determine whether juvenile delinquents would respond to the sight of someone being beaten up the same way as previously studied university students, two-thirds of the in stitutionalized delinquents in the sample watched a brief filmed prize fight after having been insulted or treated in a neutral fashion by the experimenter's confederate. A story summary given to the subjects depicted the defeated movie character as either a callous exploiter of other persons or as a more sym pathetic individual. Immediately after the film the insulted de linquents shown the exploiter being beaten administered stronger electric shocks to the confederate than a no-movie control group and somewhat more than other provoked subjects seeing the sympathetic character being hurt. Like the university students, the delinquents had apparently regarded the exploiter's beating as "justified" aggression; and this interpretation temporarily legitimated their own attacks upon their tormentor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68641/2/10.1177_002242787401100103.pd

The Economic Burden of Alcohol Dependence in Europe

Aims: To determine the economic burden pertaining to alcohol dependence in Europe. Methods: Database searching was combined with grey literature searching to identify costs and resource use in Europe relating to alcohol dependence as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) or the World Health Organisation's International Classification of Diseases (ICD-10). Searches combined MeSH headings for both economic terms and terms pertaining to alcohol dependence. Relevant outcomes included direct healthcare costs and indirect societal costs. Main resource use outcomes included hospitalization and drug costs. Results: Compared with the number of studies of the burden of alcohol use disorders in general, relatively few focussed specifically on alcohol dependence. Twenty-two studies of variable quality were eligible for inclusion. The direct costs of alcohol dependence in Europe were substantial, the treatment costs for a single alcohol-dependent patient lying within the range €1591-€7702 per hospitalization and the annual total direct costs accounting for 0.04-0.31% of an individual country's gross domestic product (GDP). These costs were driven primarily by hospitalization; in contrast, the annual drug costs for alcohol dependence were low. The indirect costs were more substantial than the direct costs, accounting for up to 0.64% of GDP per country annually. Alcohol dependence may be more costly in terms of health costs per patient than alcohol abuse. Conclusions: This review confirms that alcohol dependence represents a significant burden for European healthcare systems and society. Difficulties in comparing across cost-of-illness studies in this disease area, however, prevent specific estimation of the economic burde