Cavity solitons in vertical-cavity surface-emitting lasers

We investigate a control of the motion of localized structures of light by means of delay feedback in the transverse section of a broad area nonlinear optical system. The delayed feedback is found to induce a spontaneous motion of a solitary localized structure that is stationary and stable in the absence of feedback. We focus our analysis on an experimentally relevant system namely the Vertical-Cavity Surface-Emitting Laser (VCSEL). In the absence of the delay feedback we present experimental evidence of stationary localized structures in a 80 $\mu$m aperture VCSEL. The spontaneous formation of localized structures takes place above the lasing threshold and under optical injection. Then, we consider the effect of the time-delayed optical feedback and investigate analytically the role of the phase of the feedback and the carrier lifetime on the self-mobility properties of the localized structures. We show that these two parameters affect strongly the space time dynamics of two-dimensional localized structures. We derive an analytical formula for the threshold associated with drift instability of localized structures and a normal form equation describing the slow time evolution of the speed of the moving structure.Comment: 7 pages, 5 figure

Polarization properties of localized structures in VCSELs

Broad area Vertical-Cavity Surface-Emitting Lasers (VCSELs) have peculiar polarization properties which are a field of study by itself. These properties have already been used for localized structure generation, in a simple configuration, where only one polarization component was used. Here, we present new experimental and theoretical results on the complex polarization behavior of localized structures generated in an optically-injected broad area VCSEL. A linear stability analysis of the spin-ip VCSEL model is performed for the case of broad area devices, in a restrained and experimentally relevant parameter set. Numerical simulations are performed, in one and two dimensions. They reveal existence of vector localized structures. These structures have a complex polarization state, which is not simply a linear polarization following the one of the optical injection. Experimental results confrm theoretical predictions. Applications of this work can lead to the encoding of small color images in the polarization state of an ensemble of localized structures at the surface of a broad area VCSEL

Duplications of the critical Rubinstein-Taybi deletion region on chromosome 16p13.3 cause a novel recognisable syndrome

Background The introduction of molecular karyotyping technologies facilitated the identification of specific genetic disorders associated with imbalances of certain genomic regions. A detailed phenotypic delineation of interstitial 16p13.3 duplications is hampered by the scarcity of such patients. Objectives To delineate the phenotypic spectrum associated with interstitial 16p13.3 duplications, and perform a genotype-phenotype analysis. Results The present report describes the genotypic and phenotypic delineation of nine submicroscopic interstitial 16p13.3 duplications. The critically duplicated region encompasses a single gene, CREBBP, which is mutated or deleted in Rubinstein-Taybi syndrome. In 10 out of the 12 hitherto described probands, the duplication arose de novo. Conclusions Interstitial 16p13.3 duplications have a recognizable phenotype, characterized by normal to moderately retarded mental development, normal growth, mild arthrogryposis, frequently small and proximally implanted thumbs and characteristic facial features. Occasionally, developmental defects of the heart, genitalia, palate or the eyes are observed. The frequent de novo occurrence of 16p13.3 duplications demonstrates the reduced reproductive fitness associated with this genotype. Inheritance of the duplication from a clinically normal parent in two cases indicates that the associated phenotype is incompletely penetrant

Polarization stabilization in vertical-cavity surface-emitting lasers through asymmetric current injection

We present experimental evidence that asymmetric current injection in intracavity contacted vertical-cavity surface-emitting lasers (VCSELs) stabilizes the polarization of the emitted light. Anisotropies in the gain and loss mechanisms introduced by asymmetric current injection are considered to explain this effect. The design scheme opens perspectives to obtain actual polarization control in VCSEL

Необъяснимая боль после тотального эндопротезирования коленного сустава

Although total knee arthroplasty (TKA) improves function and reduces pain for the large majority of the patients, a few continue to have pain and require investigation. The causes of dysfunction and pain after total knee arthroplasty can be described as intrinsic (intra-articular) or extrinsic (extra-articular) sources of pain. For the majority of the cases, following a complete evaluation protocol, the cause of pain can be identified and a specific treatment can be applied, however occasionally there remains a group of patients with unexplained pain whose management is difficult. It was our hypothesis that revising a TKA without pre-operative diagnosis of the failure is not worth. Therefore, the aimed of this review was to: 1) analyse the results of revision TKA for unexplained pain, and 2) described the potential solutions for an alternative conservative management of the painful TKA.Несмотря на то, что тотальная артропластика коленного сустава приводит к улучшению функции и уменьшению болевого синдрома у подавляющего большинства пациентов, ряд больных после операции продолжают испытывать болевые ощущения. Причины боли и нарушения функции после эндопротезирования могут быть обусловлены как внутрисуставными, так внесуставными факторами. Системный подход к обследованию таких пациентов чаще всего позволяет установить источник боли и провести соответствующее лечение. Тем не менее, существует небольшая группа пациентов с необъяснимой болью, лечение которых является крайне сложной клинической задачей. Нами выдвинута гипотеза, что без четкого понимания причины неудачи первичного вмешательства проведение ревизионного эндопротезирования таким пациентам не показано. В данном обзоре литературы проведён анализ результатов реэндопротезированя коленного сустава, выполненных пациентам с необъяснимой болью и описаны возможные варианты консервативных подходов к лечению этой категории больных

Unexplained pain after total knee arthroplasty

Although total knee arthroplasty (TKA) improves function and reduces pain for the large majority of the patients, a few continue to have pain and require investigation. The causes of dysfunction and pain after total knee arthroplasty can be described as intrinsic (intra-articular) or extrinsic (extra-articular) sources of pain. For the majority of the cases, following a complete evaluation protocol, the cause of pain can be identified and a specific treatment can be applied, however occasionally there remains a group of patients with unexplained pain whose management is difficult. It was our hypothesis that revising a TKA without pre-operative diagnosis of the failure is not worth. Therefore, the aimed of this review was to: 1) analyse the results of revision TKA for unexplained pain, and 2) described the potential solutions for an alternative conservative management of the painful TKA

Evidence that breast cancer risk at the 2q35 locus is mediated through IGFBP5 regulation.

GWAS have identified a breast cancer susceptibility locus on 2q35. Here we report the fine mapping of this locus using data from 101,943 subjects from 50 case-control studies. We genotype 276 SNPs using the 'iCOGS' genotyping array and impute genotypes for a further 1,284 using 1000 Genomes Project data. All but two, strongly correlated SNPs (rs4442975 G/T and rs6721996 G/A) are excluded as candidate causal variants at odds against >100:1. The best functional candidate, rs4442975, is associated with oestrogen receptor positive (ER+) disease with an odds ratio (OR) in Europeans of 0.85 (95% confidence interval=0.84-0.87; P=1.7 × 10(-43)) per t-allele. This SNP flanks a transcriptional enhancer that physically interacts with the promoter of IGFBP5 (encoding insulin-like growth factor-binding protein 5) and displays allele-specific gene expression, FOXA1 binding and chromatin looping. Evidence suggests that the g-allele confers increased breast cancer susceptibility through relative downregulation of IGFBP5, a gene with known roles in breast cell biology

Field Validity and Feasibility of Four Techniques for the Detection of Trichuris in Simians: A Model for Monitoring Drug Efficacy in Public Health?

Worldwide, millions of people are infected with soil-transmitted helminths, particularly in developing countries. Efforts to control these infections involve periodic mass drug treatment in endemic areas. Since these large-scale interventions are likely to intensify, monitoring of drug efficacy has become a key issue in order to detect the emergence of resistance. At present, the drop in infection intensity is under examination for monitoring the drug efficacy. However, studies comparing detection techniques based on infection intensities are scarce. Moreover, little attention has been addressed to their feasibility and their ability to estimate drug efficacies. We have compared different techniques for the detection of whipworm (Trichuris) in simian stool samples based on prevalence, infection intensities, feasibility and ability to estimate the ‘true’ drug efficacy. We have found that techniques often fail to detect low infection intensities and that not all techniques are appropriate for estimating infection intensities. The time needed to obtain a test result varied from 3.9 to 17.7 min/sample. Finally, accurate estimates of drug efficacy were only obtained in high pre-drug administration infection intensities. To conclude, along with accurate estimates of infection intensities, feasibility is a considerable criterion for the detection techniques used in drug efficacy monitoring programs