Novel integrated tunable laser using filtered feedback for simple and very fast tuning

We present a novel integrated tunable laser based on filtered feedback, which combines a simple tuning method with ns switching speed

Integrated filtered-feedback tunable laser with enhanced control of feedback phase

Recently we presented a novel discretely tunable laser that consists of a Fabry-Perot laser which was forced to operate in single-mode condition by applying on-chip filtered feedback. The laser switches extremely fast (3 ns) and requires simple on/off control currents to switch the wavelength. In these first devices it was not possible to control the phase of the feedback light independently from the feedback intensity. In was solved by adding an extra electrode allowing us to control the phase separately. In this paper we present the new device and study the effect of the control ofthefeedbackphase in order to improve the performance ofthe original tunable laser concept

Integrated filtered-feedback tunable laser with enhanced control of feedback phase

Recently we presented a novel discretely tunable laser that consists of a Fabry-Perot laser which was forced to operate in single-mode condition by applying on-chip filtered feedback. The laser switches extremely fast (3 ns) and requires simple on/off control currents to switch the wavelength. In these first devices it was not possible to control the phase of the feedback light independently from the feedback intensity. In was solved by adding an extra electrode allowing us to control the phase separately. In this paper we present the new device and study the effect of the control ofthefeedbackphase in order to improve the performance ofthe original tunable laser concept

Fast integrated tunable laser using filtered feedback

A novel integrated tunable laser is presented which combines a simple tuning method with ns switching speed. The Photonic Integrated Circuit consists of a Fabry-Perot laser with deeply-etched DBR mirrors. The Fabry-Perot modes can be selected independently using an Arrayed Waveguide Grating and then re-injected into the laser cavity, forcing single mode operation at the wavelength of that mode. 4ns switching time as well as 15 dB SMSR is demonstrated on the prototype device

Widely tunable laser source operating at 2μm realized as monolithic InP photonic integrated circuit

A tunable laser operating from 2011 – 2042 nm realized as a monolithic InP photonic integrated circuit and fabricated within a multi project wafer run is presented. The laser is tuned using an intracavity filter based on nested asymmetric Mach-Zehnder interferometers with electrorefractive modulators. The device is intended for a single line gas spectroscopy and was designed and realized using a generic integration technology

PIP5KIβ Selectively Modulates Apical Endocytosis in Polarized Renal Epithelial Cells

Localized synthesis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at clathrin coated pits (CCPs) is crucial for the recruitment of adaptors and other components of the internalization machinery, as well as for regulating actin dynamics during endocytosis. PtdIns(4,5)P2 is synthesized from phosphatidylinositol 4-phosphate by any of three phosphatidylinositol 5-kinase type I (PIP5KI) isoforms (α, β or γ). PIP5KIβ localizes almost exclusively to the apical surface in polarized mouse cortical collecting duct cells, whereas the other isoforms have a less polarized membrane distribution. We therefore investigated the role of PIP5KI isoforms in endocytosis at the apical and basolateral domains. Endocytosis at the apical surface is known to occur more slowly than at the basolateral surface. Apical endocytosis was selectively stimulated by overexpression of PIP5KIβ whereas the other isoforms had no effect on either apical or basolateral internalization. We found no difference in the affinity for PtdIns(4,5)P2-containing liposomes of the PtdIns(4,5)P2 binding domains of epsin and Dab2, consistent with a generic effect of elevated PtdIns(4,5)P2 on apical endocytosis. Additionally, using apical total internal reflection fluorescence imaging and electron microscopy we found that cells overexpressing PIP5KIβ have fewer apical CCPs but more internalized coated structures than control cells, consistent with enhanced maturation of apical CCPs. Together, our results suggest that synthesis of PtdIns(4,5)P2 mediated by PIP5KIβ is rate limiting for apical but not basolateral endocytosis in polarized kidney cells. PtdIns(4,5)P2 may be required to overcome specific structural constraints that limit the efficiency of apical endocytosis. © 2013 Szalinski et al

HETEAC – the Hybrid End-To-End Aerosol Classification model for EarthCARE

The Hybrid End-To-End Aerosol Classification (HETEAC) model for the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) mission is introduced. The model serves as the common baseline for the development, evaluation, and implementation of EarthCARE algorithms. It guarantees the consistency of different aerosol products from the multi-instrument platform and facilitates the conformity of broad-band optical properties needed for EarthCARE radiative-closure assessments. While the hybrid approach ensures that the theoretical description of aerosol microphysical properties is consistent with the optical properties of the measured aerosol types, the end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical, and radiative properties. Four basic aerosol components with prescribed microphysical properties are used to compose various natural and anthropogenic aerosols of the troposphere. The components contain weakly and strongly absorbing fine-mode and spherical and non-spherical coarse-mode particles and thus are representative for pollution, smoke, sea salt, and dust, respectively. Their microphysical properties are selected such that good coverage of the observational phase space of intensive, i.e., concentration-independent, optical aerosol properties derived from EarthCARE measurements is obtained. Mixing rules to calculate optical and radiative properties of any aerosol blend composed of the four basic components are provided. Applications of HETEAC in the generation of test scenes, the development of retrieval algorithms for stand-alone and synergistic aerosol products from EarthCARE's atmospheric lidar (ATLID) and multi-spectral imager (MSI), and for radiative-closure assessments are introduced. Finally, the implications of simplifying model assumptions and possible improvements are discussed, and conclusions for future validation and development work are drawn.</p

Relating circulating thyroid hormone concentrations to serum interleukins-6 and -10 in association with non-thyroidal illnesses including chronic renal insufficiency

<p>Abstract</p> <p>Background</p> <p>Because of the possible role of cytokines including interleukins (IL) in systemic non-thyroidal illnesses' (NTI) pathogenesis and consequently the frequently associated alterations in thyroid hormone (TH) concentrations constituting the euthyroid sick syndrome (ESS), we aimed in this research to elucidate the possible relation between IL-6 & IL-10 and any documented ESS in a cohort of patients with NTI.</p> <p>Methods</p> <p>Sixty patients and twenty healthy volunteers were recruited. The patients were subdivided into three subgroups depending on their underlying NTI and included 20 patients with chronic renal insufficiency (CRI), congestive heart failure (CHF), and ICU patients with myocardial infarction (MI). Determination of the circulating serum levels of IL-6 and IL-10, thyroid stimulating hormone (TSH), as well as total T4 and T3 was carried out.</p> <p>Results</p> <p>In the whole group of patients, we detected a significantly lower T3 and T4 levels compared to control subjects (0.938 ± 0.477 vs 1.345 ± 0.44 nmol/L, p = 0.001 and 47.9 ± 28.41 vs 108 ± 19.49 nmol/L, p < 0.0001 respectively) while the TSH level was normal (1.08+0.518 μIU/L). Further, IL-6 was substantially higher above controls' levels (105.18 ± 72.01 vs 3.35 ± 1.18 ng/L, p < 0.00001) and correlated negatively with both T3 and T4 (r = -0.620, p < 0.0001 & -0.267, p < 0.001, respectively). Similarly was IL-10 level (74.13 ± 52.99 vs 2.64 ± 0.92 ng/ml, p < 0.00001) that correlated negatively with T3 (r = -0.512, p < 0.0001) but not T4. Interestingly, both interleukins correlated positively (r = 0.770, p = <0.001). Moreover, IL-6 (R²= 0.338, p = 0.001) and not IL-10 was a predictor of low T3 levels with only a borderline significance for T4 (R²= 0.082, p = 0.071).</p> <p>By subgroup analysis, the proportion of patients with subnormal T3, T4, and TSH levels was highest in the MI patients (70%, 70%, and 72%, respectively) who displayed the greatest IL-6 and IL-10 concentrations (192.5 ± 45.1 ng/L & 122.95 ± 46.1 ng/L, respectively) compared with CHF (82.95 ± 28.9 ng/L & 69.05 ± 44.0 ng/L, respectively) and CRI patients (40.05 ± 28.9 ng/L & 30.4 ± 10.6 ng/L, respectively). Surprisingly, CRI patients showed the least disturbance in IL-6 and IL-10 despite the lower levels of T3, T4, and TSH in a higher proportion of them compared to CHF patients (40%, 45%, & 26% vs 35%, 25%, & 18%, respectively).</p> <p>Conclusion</p> <p>the high prevalence of ESS we detected in NTI including CRI may be linked to IL-6 and IL-10 alterations. Further, perturbation of IL-6 and not IL-10 might be involved in ESS pathogenesis although it is not the only key player as suggested by our findings in CRI.</p