Quasicrystalline three-dimensional foams.

We present a numerical study of quasiperiodic foams, in which the bubbles are generated as duals of quasiperiodic Frank-Kasper phases. These foams are investigated as potential candidates to the celebrated Kelvin problem for the partition of three-dimensional space with equal volume bubbles and minimal surface area. Interestingly, one of the computed structures falls close to (but still slightly above) the best known Weaire-Phelan periodic candidate. In addition we find a correlation between the normalized bubble surface area and the root mean squared deviation of the number of faces, giving an additional clue to understanding the main geometrical ingredients driving the Kelvin problem.

Entanglement in the symmetric sector of n qubits.

We discuss the entanglement properties of symmetric states of n qubits. The Majorana representation maps a generic such state into a system of n points on a sphere. Entanglement invariants, either under local unitaries (LU) or stochastic local operations and classical communication (SLOCC), can then be addressed in terms of the relative positions of the Majorana points. In the LU case, an overcomplete set of invariants can be built from the inner product of the radial vectors pointing to these points; this is detailed for the well-documented three-qubits case. In the SLOCC case, a cross ratio of related Möbius transformations are shown to play a central role, exemplified here for four qubits. Finally, as a side result, we also analyze the manifold of maximally entangled 3 qubit state, both in the symmetric and generic case.

Aperiodic quantum random walks.

We generalize the quantum random walk protocol for a particle in a one-dimensional chain, by using several types of biased quantum coins, arranged in aperiodic sequences, in a manner that leads to a rich variety of possible wave-function evolutions. Quasiperiodic sequences, following the Fibonacci prescription, are of particular interest, leading to a sub-ballistic wave-function spreading. In contrast, random sequences lead to diffusive spreading, similar to the classical random walk behavior. We also describe how to experimentally implement these aperiodic sequences.

Streptococcus acidominimus infection in a child causing Gradenigo syndrome.

UNLABELLED: Gradenigo syndrome is a rare presentation of acute petrositis. The clinical triad of Gradenigo syndrome consists of acute suppurative otitis media, severe unilateral headache and abducens nerve palsy. We report the first case of Gradenigo syndrome caused by Streptococcus acidominimus, a Gram-positive coccus of the Streptococcus viridans group, which rarely causes deep-seated infection in humans. CONCLUSION: Gradenigo syndrome may complicate acute otitis media and should be suspected in case of unilateral headache and abducens nerve palsy. Conservative medical treatment without surgery may be considered in some patients.

Concomitant aseptic meningitis and bacterial urinary tract infection in young febrile infants.

We evaluated the incidence and implications of coexistent bacterial urinary tract infection and aseptic meningitis in 1629 young febrile infants (age 1 to 60 days) who underwent sepsis work-up. Urinary tract infection was diagnosed in 13.2% and aseptic meningitis in 8.8%. Eleven patients (0.7%) had both infections. In view of possible coinfection initial laboratory results may be insufficient for decision-making regarding treatment in young febrile infants.

Guttate psoriasis following Kawasaki disease.

Guttate psoriasis developed in a 3.5-year-old boy during the course of Kawasaki disease (KD). The pathogenesis of this unusual complication may be production of superantigens, which is also considered to be a cause of KD.

Interaction induced delocalization for two particles in a periodic potential

We consider two interacting particles evolving in a one-dimensional periodic structure embedded in a magnetic field. We show that the strong localization induced by the magnetic field for particular values of the flux per unit cell is destroyed as soon as the particles interact. We study the spectral and dynamical aspects of this transition.

Gluconeogenesis in non-obese diabetic (NOD) mice: in vivo effects of vandadate treatment on hepatic glucose-6-phoshatase and phosphoenolpyruvate carboxykinase.

The contribution of gluconeogenesis to hyperglycemia in non-obese diabetic (NOD) mice has been investigated using oral vanadate administration. Vanadate compounds have been shown to mimic many actions of insulin; however, the exact mechanism is poorly understood. The aims of the present study were (1) to elucidate vanadate's action in vivo, and to assess the possibility that its glucose-reducing effect is dependent on the presence of a minimal concentration of insulin; and (2) to evaluate the effects of vanadate administration on the key hepatic gluconeogenesis enzymes, glucose-6-phosphatase (G-6-Pase) and phosphoenolpyruvate carboxykinase (PEPCK), as well as glucose-6-phosphate dehydrogenase (G-6-PDH). Vanadate caused a significant reduction in blood glucose but failed to normalize it, despite effective serum vanadate concentrations (26.2 +/- 1.6 micromol/L). Two weeks after initiation of treatment, blood glucose levels were 26.0 +/- 1.8, 21.7 +/- 3.0, 16.0 +/- 1.6, and 14.3 +/- 2.3 mmol/L in the control (C), insulin (I), vanadate (V), and combined vanadate and insulin (V + I) groups, respectively (P < .001). G-6-Pase activity was significantly reduced by vanadate (622 +/- 134 v365 +/- 83 nmol/min/mg protein in C vV, P < .05). PEPCK activity was also significantly reduced (844 +/- 370, 623 +/- 36, 337 +/- 43, and 317 +/- 75 nmol/min/mg in the C, I, V, and V + I groups, respectively, P < .001). No significant differences in the hepatic glycogen stores and G-6-PDH activity were noted between treatment groups. Our study suggests that the inhibition of hepatic G-6-Pase and PEPCK activity by vanadate plays an important role in reducing blood glucose levels in NOD mice.

[Painful extensor digitorum brevis]. / Douleurs en rapport avec un court extenseur des doigts.

A boxer suffered from a painful extensor digitorum brevis muscle. The pathology involved the proximal insertion on the lunate and caused a specific form of carpal instability. On excision of the muscle the pain disappeared.

Peripheral intravenous infusion--another cause of air embolism.

We report an unusual complication of intravenous infusion. A 4-week-old baby developed acute cardiopulmonary distress because of air embolism caused by improper preparation of peripheral intravenous set. The estimated amount of infused air was 12 ml (approximately 3.5 ml/kg). The infant recovered promptly after short supportive treatment.

Reactogenicity and immunogenicity of a new recombinant hepatitis B vaccine containing Pre S antigens: a preliminary report.

A new vaccine against hepatitis B virus (HBV) infection, produced in mammalian Chinese hamster ovary (CHO) cells, contains the small(s), middle (Pre S2) and large (Pre S1) surface proteins of HBV. Three injections of a 5-micrograms or 10-micrograms dose were administered intramuscularly (i.m.) at 0, 1 and 6 months to a group of 105 young adults, who were monitored for a period of 6 months after the third injection. Seroconversion rates were 100% after the second injection of the 5-micrograms or 10-micrograms dose. Geometric mean titres of HBsAb at 1 month after the third injection were 12,156 mIU ml-1 and 13,482 mIU ml-1 in those receiving the 5-micrograms and 10-micrograms dose respectively. The vaccine was well tolerated with no significant adverse events. These preliminary results suggest that the Pre S-s recombinant vaccine, produced in mammalian cells, is highly immunogenic, leading to 100% seroconversion in the population tested after injection of only two doses of 5 micrograms.

Orgons and biolons in theoretical biology: phenomenological analysis and quantum analogies.

In this paper we define two types of formal biological entities corresponding to biological levels of organization, the biolons and the orgons, the properties of which are phenomenologically analyzed and discussed. We examine then, in a rather speculative manner, how some characteristics of these entities may suggest analogies between properties of biological systems and some special features of quantum systems. These analogies are principally related to the specific roles played by these entities (relatively to matter-energy, for orgons, and to information, for biolons) in a biological system. They are funded on the formal equivalence between the temporal variations associated to the development of the orgons and the biolons, respectively, and the statistical distribution over the available energy levels of the two main types of quantum entities, the fermions and the bosons (the former being associated to the constitution of matter and the latter to the effects of interactions). This formal comparison leads us to put into correspondences the developmental duration in biological systems with the energetic structuration in quantum ones and the related characteristic times of the former with the temperature of the latter. We discuss briefly these correspondences.

[Quasicrystal organization in extracellular matrixes]. / Ordre quasicristallin dans les matrices extracellulaires.

In this note we argue that the theoretical approach, developed in the field of quasicrystals, may prove to be useful in a completely different area, namely biology, and more precisely for the transmission electron microscopy observation of biological structures this sections. Whatever the real three-dimensional structure is periodic, a generic cut will produce a quasiperiodic pattern. This is illustrated in a "theoretical" example inspired by the 3D organization of annelid cuticle. In addition, we discuss recent results on dislocations in quasicrystals, and their possible consequence about observation in biology. Finally, this analysis could be extended to images obtained from other technics, like freeze-fracture, and other materials, provided that certain length scale relations be satisfied.

Distribution of polysaccharide side chains of lipopolysaccharide determine resistance of Escherichia coli to the bactericidal activity of serum.

The lipopolysaccharide (LPS) of serum-sensitive strains of Escherichia coli was compared with LPS derived from serum-resistant clones. Polysaccharide O-antigen side chains (PSSC) of LPS from serum-resistant clones contained 12%-40% more of the longer carbohydrate molecules (L-PSSC) than did LPS from serum-sensitive parent strains; in contrast, 12%-27% more of the shorter PSSC (S-PSSC) were found in LPS from serum-sensitive strains. The sensitivity or resistance to the bactericidal activity of human serum correlated with the distribution and the length of PSSC fractions of LPS. This was demonstrated in a liposome model in which LPS was incorporated into simulated bacterial membranes. The incubation of serum with liposomes incorporated with various ratios of S-PSSC-to-L-PSSC concentrations resulted in liposomal lysis at S-PSSC-to-L-PSSC ratios greater than 2:1. These findings demonstrate the importance of the length of carbohydrate side chains of LPS in determining sensitivity or resistance to the bactericidal activity of human serum.

A dynamical system for biological development: the case of Caenorhabditis elegans.

We show how a simple nonlinear dynamical system (the discrete quadratic iteration on the unit segment) can be the basis for modelling the embryogenesis process. Such an approach, even though being crude, can nevertheless prove to be useful when looking with the two main involved processes: (i) on one hand the cell proliferation under successive divisions; (ii) on the other hand, the differentiation between cell lineages. We illustrate this new approach in the case of Caenrhabditis elegans by looking at the early stages of embryogenesis, up to several hundreds of cells ("lima bean" larval stage). We show how the many results that have been obtained by several groups can be interpreted in terms of values for the parameters controlling the dynamical system. Furthermore, we can extend the model to the cases of genetic mutations. More precisely the teratogenetic and lethal effects are associated with abnormal variation of teh control parameters with time.

[A rare cause of obstruction: hernia through the hiatus of Winslow. Apropos of 3 cases]. / Une cause rare d'occlusion: la hernie à travers l'hiatus de Winslow. A propos de trois cas.

Exceptional pathology whose preoperative diagnosis is based upon clinical and radiological signs; the herniation through the foramen of Winslow is a variety of internal herniation. About three recent cases observed in the service, it seemed interesting to see, reviewing literature, what are the diagnostic characters and therapeutic modalities knowing difficulties because of a quasi exclusive vascular collect.