Fine speckle contrast in InGaAs/InP systems: Influence of layer thickness, missmatch, and growing temperature

This work is focused on the study of the fine speckle contrast present in planar view observations of matched and mismatched InGaAs layers grown by molecular beam epitaxy on InP substrates. Our results provide experimental evidence of the evolution of this fine structure with the mismatch, layer thickness, and growth temperature. The correlation of the influence of all these parameters on the appearance of the contrast modulation points to the development of the fine structure during the growth. Moreover, as growth proceeds, this structure shows a dynamic behavior which depends on the intrinsic layer substrate stress.

Pharmacokinetic and pharmacodynamic analysis of efavirenz dose reduction using an in vitro-in vivo extrapolation model.

The pharmacokinetics (PK) of efavirenz (EFV) is characterized by marked interpatient variability that correlates with its pharmacodynamics (PD). In vitro-in vivo extrapolation (IVIVE) is a "bottom-up" approach that combines drug data with system information to predict PK and PD. The aim of this study was to simulate EFV PK and PD after dose reductions. At the standard dose, the simulated probability was 80% for viral suppression and 28% for central nervous system (CNS) toxicity. After a dose reduction to 400 mg, the probabilities of viral suppression were reduced to 69, 75, and 82%, and those of CNS toxicity were 21, 24, and 29% for the 516 GG, 516 GT, and 516 TT genotypes, respectively. With reduction of the dose to 200 mg, the probabilities of viral suppression decreased to 54, 62, and 72% and those of CNS toxicity decreased to 13, 18, and 20% for the 516 GG, 516 GT, and 516 TT genotypes, respectively. These findings indicate how dose reductions might be applied in patients with favorable genetic characteristics.

A high proportion of users of low-threshold facilities with needle exchange programmes in Switzerland are currently on methadone treatment: implications for new approaches in harm reduction and care.

BACKGROUND: Increasingly, patients receiving methadone treatment are found in low threshold facilities (LTF), which provide needle exchange programmes in Switzerland. This paper identifies the characteristics of LTF attendees receiving methadone treatment (MT) compared with other LTF attendees (non-MT). METHODS: A national cross-sectional survey was conducted in 2006 over five consecutive days in all LTF (n=25). Attendees were given an anonymous questionnaire, collecting information on socio-demographic indicators, drug consumption, injection, methadone treatment, and self-reported HIV and HCV status. Univariate analysis and logistic regression were performed to compare MT to non-MT. The response rate was 66% (n=1128). RESULTS: MT comprised 57.6% of the sample. In multivariate analysis, factors associated with being on MT were older age (OR: 1.38), being female (OR: 1.60), having one's own accommodation (OR: 1.56), receiving public assistance (OR: 2.29), lifetime injecting (OR: 2.26), HIV-positive status (OR: 2.00), and having consumed cocaine during the past month (OR: 1.37); MT were less likely to have consumed heroin in the past month (OR: 0.76, not significant) and visited LTF less often on a daily basis (OR: 0.59). The number of injections during the past week was not associated with MT. CONCLUSIONS: More LTF attendees were in the MT group, bringing to light an underappreciated LTF clientele with specific needs. The MT group consumption profile may reflect therapeutic failure or deficits in treatment quality and it is necessary to acknowledge this and to strengthen the awareness of LTF personnel about potential needs of MT attendees to meet their therapeutic goals.

Improving Reconstituted HDL Composition for Efficient Post-Ischemic Reduction of Ischemia Reperfusion Injury.

BACKGROUND: New evidence shows that high density lipoproteins (HDL) have protective effects beyond their role in reverse cholesterol transport. Reconstituted HDL (rHDL) offer an attractive means of clinically exploiting these novel effects including cardioprotection against ischemia reperfusion injury (IRI). However, basic rHDL composition is limited to apolipoprotein AI (apoAI) and phospholipids; addition of bioactive compound may enhance its beneficial effects. OBJECTIVE: The aim of this study was to investigate the role of rHDL in post-ischemic model, and to analyze the potential impact of sphingosine-1-phosphate (S1P) in rHDL formulations. METHODS AND RESULTS: The impact of HDL on IRI was investigated using complementary in vivo, ex vivo and in vitro IRI models. Acute post-ischemic treatment with native HDL significantly reduced infarct size and cell death in the ex vivo, isolated heart (Langendorff) model and the in vivo model (-48%, p<0.01). Treatment with rHDL of basic formulation (apoAI + phospholipids) had a non-significant impact on cell death in vitro and on the infarct size ex vivo and in vivo. In contrast, rHDL containing S1P had a highly significant, protective influence ex vivo, and in vivo (-50%, p<0.01). This impact was comparable with the effects observed with native HDL. Pro-survival signaling proteins, Akt, STAT3 and ERK1/2 were similarly activated by HDL and rHDL containing S1P both in vitro (isolated cardiomyocytes) and in vivo. CONCLUSION: HDL afford protection against IRI in a clinically relevant model (post-ischemia). rHDL is significantly protective if supplemented with S1P. The protective impact of HDL appears to target directly the cardiomyocyte.

Dimensional reduction and gauge group reduction in Bianchi-type cosmology

In this paper we examine in detail the implementation, with its associated difficulties, of the Killing conditions and gauge fixing into the variational principle formulation of Bianchi-type cosmologies. We address problems raised in the literature concerning the Lagrangian and the Hamiltonian formulations: We prove their equivalence, make clear the role of the homogeneity preserving diffeomorphisms in the phase space approach, and show that the number of physical degrees of freedom is the same in the Hamiltonian and Lagrangian formulations. Residual gauge transformations play an important role in our approach, and we suggest that Poincaré transformations for special relativistic systems can be understood as residual gauge transformations. In the Appendixes, we give the general computation of the equations of motion and the Lagrangian for any Bianchi-type vacuum metric and for spatially homogeneous Maxwell fields in a nondynamical background (with zero currents). We also illustrate our counting of degrees of freedom in an appendix.

Kinematic reduction of reaction-diffusion fronts with multiplicative noise. Derivation of stochastic sharp-interface equations

We study the dynamics of generic reaction-diffusion fronts, including pulses and chemical waves, in the presence of multiplicative noise. We discuss the connection between the reaction-diffusion Langevin-like field equations and the kinematic (eikonal) description in terms of a stochastic moving-boundary or sharp-interface approximation. We find that the effective noise is additive and we relate its strength to the noise parameters in the original field equations, to first order in noise strength, but including a partial resummation to all orders which captures the singular dependence on the microscopic cutoff associated with the spatial correlation of the noise. This dependence is essential for a quantitative and qualitative understanding of fluctuating fronts, affecting both scaling properties and nonuniversal quantities. Our results predict phenomena such as the shift of the transition point between the pushed and pulled regimes of front propagation, in terms of the noise parameters, and the corresponding transition to a non-Kardar-Parisi-Zhang universality class. We assess the quantitative validity of the results in several examples including equilibrium fluctuations and kinetic roughening. We also predict and observe a noise-induced pushed-pulled transition. The analytical predictions are successfully tested against rigorous results and show excellent agreement with numerical simulations of reaction-diffusion field equations with multiplicative noise.

New approach for weight reduction by a combination of diet, light resistance exercise and the timing of ingesting a protein supplement.

We have reported that ingesting a meal immediately after exercise increased skeletal muscle accretion and less adipose tissue accumulation in rats employed in a 10 week resistance exercise program. We hypothesized that a possible increase in the resting metabolic rate (RMR) as a result of the larger skeletal muscle mass might be responsible for the less adipose deposition. Therefore, the effect of the timing of a protein supplement after resistance exercise on body composition and the RMR was investigated in 17 slightly overweight men. The subjects participated in a 12-week weight reduction program consisting of mild energy restriction (17% energy intake reduction) and a light resistance exercise using a pair of dumbbells (3-5 kg). The subjects were assigned to two groups. Group S ingested a protein supplement (10 g protein, 7 g carbohydrate, 3.3 g fat and one-third of recommended daily allowance (RDA) of vitamins and minerals) immediately after exercise. Group C did not ingest the supplement. Daily intake of both energy and protein was equal between the two groups and the protein intake met the RDA. After 12 weeks, the bodyweight, skinfold thickness, girth of waist and hip and percentage bodyfat significantly decreased in the both groups, however, no significant differences were observed between the groups. The fat-free mass significantly decreased in C, whereas its decrease in S was not significant. The RMR and post-meal total energy output significantly increased in S, while these variables did not change in C. In addition, the urinary nitrogen excretion tended to increase in C but not in S. These results suggest that the RMR increase observed in S might be associated with an increase in body protein synthesis.

Reduction of the effect of aberrations in a joint transform correlator

We report the study of the influence of optical aberrations in a joint-transform correlator: The wave aberration of the optical system is computed from data obtained by ray tracing. Three situations are explored: We consider the aberration only in the first diffraction stage (generation of power spectrum), then only in the second (transformation of the power spectrum into correlation), and finally in both stages simultaneously. The results show that the quality of the correlation is determined mostly by the aberrations of the first diffraction stage and that we can optimize the setup by moving the cameras along the optical axis to a suitable position. The good agreement between the predicted data and the experimental results shows that the method explains well the behavior of optical diffraction systems when aberrations are taken into account.

A reduction of order two for infinite-order Lagrangians

Given a Lagrangian system depending on the position derivatives of any order, and assuming that certain conditions are satisfied, a second-order differential system is obtained such that its solutions also satisfy the Euler equations derived from the original Lagrangian. A generalization of the singular Lagrangian formalism permits a reduction of order keeping the canonical formalism in sight. Finally, the general results obtained in the first part of the paper are applied to Wheeler-Feynman electrodynamics for two charged point particles up to order 1/c4.

Complications of Valve Lung Volume Reduction in a Case of Previous Pleurodesis.

Lung volume reduction with valves is increasingly used to treat selected patients with severe emphysema. The indications for this procedure have been previously described; however, its contraindications have not yet been conclusively established. This case highlights the potentially severe complications of endobronchial one-way valve placement in the setting of a previous pleurodesis.

Free conjunctival autologous graft for bleb repair and bleb reduction after trabeculectomy and nonpenetrating filtering surgery.

PURPOSE: To describe methods and outcomes of excisional revision of a filtering bleb (bleb revision) using free conjunctival autologous graft either for bleb repair or for bleb reduction after trabeculectomy and deep sclerectomy with an implant. METHODS: Retrospective medical records were reviewed for a consecutive non-comparative case series comprising patients who underwent excisional revision of a filtering bleb between May 1998-January 2001. Excisional revision using free conjunctival autologous graft (bleb revision) was performed either for bleb repair, to treat early and late leaks and hypotony with maculopathy, or for bleb reduction, to improve ocular pain, discomfort, burning, foreign body sensation, tearing, and fluctuations of visual acuity. The revision consisted of bleb excision and free conjunctival autologous graft. The bleb histopathology was analyzed in patients who underwent bleb repair. RESULTS: Sixteen patients were included in the study, consisting of nine patients who had a trabeculectomy and seven patients who had a deep sclerectomy with an implant. Bleb revision was necessary in 14 patients due to leaking filtering bleb (bleb repair), and in 2 patients due to bleb dysesthesia (bleb reduction). After a follow-up of 15.1 +/- 8.4 months, the mean intraocular pressure (IOP) rose from 7.8 +/- 6.3 mm Hg to 14.3 +/- 6.5 mm Hg, and the visual acuity from 0.4 +/- 0.3 to 0.7 +/- 0.3, with a P value of 0.008 and 0.03, respectively. The complete success rate at 32 months, according to the Kaplan-Meier survival curve, was 38.3%, and the qualified success rate was 83.3%. Four patients (25%) required additional suturing for persistent bleb leak. To control IOP, antiglaucoma medical therapy was needed for six patients (37.5%) and repeated glaucoma surgery was needed for one patient. CONCLUSION: Free conjunctival autologous graft is a safe and successful procedure for bleb repair and bleb reduction. However, patients should be aware of the postoperative possibility of requiring medical or surgical intervention for IOP control after revision.

Effect of Vagus Nerve Stimulation in an Adult Patient with Dravet Syndrome: Contribution to Sudden Unexpected Death in Epilepsy Risk Reduction?.

We report on a patient who developed, from 5 months of age, multiple seizure types, including myoclonic, associated with severe psychomotor delay, leading to the diagnosis of Dravet syndrome. Over the years, he developed refractory epilepsy and was implanted with a vagus nerve stimulator at the age of 19. After 3 months, he experienced a progressive improvement of partial and generalized seizures, with a >90% reduction, and better alertness. This meaningful clinical improvement is discussed in the light of the sudden unexpected death in epilepsy risk, which is high in this setting, and seems remarkably diminished in our patient in view of the reduction of generalized convulsions.