The relationship of systemic markers of renal function and vascular function with retinal blood vessel responses

Purpose: To test the hypothesis of a significant relationship between systemic markers of renal and vascular function (processes linked to cardiovascular disease and its development) and retinal microvascular function in diabetes and/or cardiovascular disease.Methods: Ocular microcirculatory function was measured in 116 patients with diabetes and/or cardiovascular disease using static and continuous retinal vessel responses to three cycles of flickering light. Endothelial function was evaluated by von Willebrand factor (vWf), endothelial microparticles and soluble E selectin, renal function by serum creatinine, creatinine clearance and estimated glomerular filtration rate (eGFR). HbA1c was used as a control index.Results: Central retinal vein equivalence and venous maximum dilation to flicker were linked to HbA1c (both p<0.05). Arterial reaction time was linked to serum creatinine (p=0.036) and eGFR (p=0.039), venous reaction time was linked to creatinine clearance (p=0.018). Creatinine clearance and eGFR were linked to arterial maximum dilatation (p<0.001 and p=0.003 respectively) and the dilatation amplitude (p=0.038 and p=0.048 respectively) responses in the third flicker cycle. Of venous responses to the first flicker cycle, HbA1c was linked to the maximum dilation response (p=0.004) and dilatation amplitude (p=0.017), vWf was linked to the maximum constriction response (p=0.016), and creatinine clearance to the baseline diameter fluctuation (p=0.029). In the second flicker cycle, dilatation amplitude was linked to serum creatinine (p=0.022). Conclusions: Several retinal blood vessel responses to flickering light are linked to glycaemia and renal function, but only one index is linked to endothelial function. Renal function must be considered when interpreting retinal vessel responses

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Observed temperature changes in the troposphere and stratosphere from 1979 to 2018

Temperature observations of the upper-air atmosphere are now available for more than 40 years from both ground- and satellite-based observing systems. Recent years have seen substantial improvements in reducing long-standing discrepancies among datasets through major reprocessing efforts. The advent of radio occultation (RO) observations in 2001 has led to further improvements in vertically resolved temperature measurements, enabling a detailed analysis of upper-troposphere/lower-stratosphere trends. This paper presents the current state of atmospheric temperature trends from the latest available observational records. We analyze observations from merged operational satellite measurements, radiosondes, lidars, and RO, spanning a vertical range from the lower troposphere to the upper stratosphere. The focus is on assessing climate trends and on identifying the degree of consistency among the observational systems. The results show a robust cooling of the stratosphere of about 1–3 K, and a robust warming of the troposphere of about 0.6–0.8 K over the last four decades (1979– 2018). Consistent results are found between the satellite-based layer-average temperatures and vertically resolved radiosonde records. The overall latitude–altitude trend patterns are consistent between RO and radiosonde records. Significant warming of the troposphere is evident in the RO measurements available after 2001, with trends of 0.25–0.35 K per decade. Amplified warming in the tropical upper-troposphere compared to surface trends for 2002–18 is found based on RO and radiosonde records, in approximate agreement with moist adiabatic lapse rate theory. The consistency of trend results from the latest upper-air datasets will help to improve understanding of climate changes and their drivers

Developing of a photonic hardware platform for brain-inspired computing based on 5X5 VCSEL arrays

International audienceBrain-inspired computing concepts like artificial neural networks have become promising<br&gtalternatives to classical von Neumann computer architectures. Photonic neural networks target the<br&gtrealizations of neurons, network connections and potentially learning in photonic substrates. Here,<br&gtwe report the development of a nanophotonic hardware platform of fast and energy-efficient<br&gtphotonic neurons via arrays of high-quality vertical cavity surface emitting lasers (VCSELs). The<br&gtdeveloped 5×5 VCSEL arrays provide high optical injection locking efficiency through<br&gthomogeneous fabrication combined with individual control over the laser wavelengths. Injection<br&gtlocking is crucial for the reliable processing of information in VCSEL-based photonic neurons, and<br&gtwe demonstrate the suitability of the VCSEL arrays by injection locking measurements and<br&gtcurrent-induced spectral fine-tuning. We find that our investigated array can readily be tuned to<br&gtthe required spectral homogeneity, and as such show that VCSEL arrays based on our technology<br&gtcan act as highly energy efficient and ultra-fast photonic neurons for next generation photonic<br&gtneural networks. Combined with fully parallel photonic networks our substrates are promising for<br&gtultra-fast operation reaching 10 s of GHz bandwidths, and we show that a single non-linear<br&gttransformation based on our lasers will consume only about 100 fJ per VCSEL, which is highly<br&gtcompetitive, compared to other platforms

Trees improve water storage and reduce soil evaporation in agroforestry systems on bench terraces in SW Uganda

The success of agroforestry in semi-arid areas depends on efficient use of available water and effective strategies to limit tree/crop competition and maximise productivity. On hillsides, planting improved tree fallows on the degraded upper section of bench terraces is a recommended practice to improve soil fertility while cropping continues on the lower terrace to maintain food production. This study examined the influence of tree fallows on soil water content (θ w ) and evaporation (E s ). Alnus acuminata Kunth (alnus), Calliandra calothyrsus Meissner (calliandra), Sesbania sesban L. (sesbania), a mixture of all three species, or sole crops (beans (Phaseolus vulgaris L.) or maize (Zea mays L.)) were grown on the upper terrace. The same sole crops were grown on the lower terrace. Four management regimes (unpruned, root, shoot and root + shoot pruned) were applied to the tree rows adjacent to the cropping area. Neutron probe and microlysimeter approaches were used to determine θ w and E s when the trees were c. 3.5 years old. Sesbania and alnus increased θ w by 9–18 % in the cropping area on the lower terrace but calliandra reduced θ w by 3–15 %. After heavy rain, E s comprised 29–38 % of precipitation in the tree-based treatments and 53 % under sole crops. Absolute values declined as rainfall decreased, but E s as a proportion of rainfall increased to 39–45 % in the tree-based treatments and 62 % for sole crops. Root + shoot pruning of alnus and the tree mixture increased θ w in the cropping area but had no significant effect in the other tree-based treatments. The results suggest that sesbania and alnus can be planted on smallholdings without compromising water supply to adjacent crops, whereas calliandra decreased water availability despite reducing E s . These results provide a mechanistic understanding of reported effects on crop yield in the same site

Observation of the Huygens-principle growth mechanism in sputtered W/Si multilayers

We have investigated the interfacial roughness of a W/Si multilayer sputtered at high Ar gas pressure. The roughness exponents as determined from diffuse X-ray scattering agree well with the Huygens-principle growth model proposed by Tang, Alexander and Bruinsma (TAB). Simple microscopic explanations are given to account for the finding of Edwards-Wilkinson (EW) type growth at low Ar pressure and the TAB growth mechanism at high pressures, as well as for the absence of any scaling according to the Kardar-Parisi-Zhang (KPZ) equation

Boosting the output power of large-aperture lasers by breaking their circular symmetry

Breaking the spatial symmetry in optical systems has become a key approach to the study of nonlinear dynamics, wave chaos, and non-Hermitian physics. Moreover, it enables tailoring of the spatiotemporal properties of such systems. Breaking the circular symmetry of lasers yields a more uniform light intensity profile within the optical aperture and makes uniform the spectral distribution of the optical states (modes). Those effects are known to enhance spontaneous as well as stimulated emission and consequently suppress undesired nonradiative recombination in the active region, but their importance for laser emission is not fully understood so far. In this paper, using the example of vertical-cavity surface-emitting lasers, we show that intentionally deformed optical apertures induce a more uniform light intensity distribution within the optical aperture, related to wave chaos, and a higher density of optical states, enhancing stimulated emission as predicted by quantum electrodynamics theory. These two phenomena contribute to increasing the optical output power by more than 60% and quantum efficiency by more than 10%. The results of this study are of significant importance for a variety of lasers, showing a clear link between the fundamentals of their operation and quantum electrodynamics and providing a general, robust method of enhancing emitted power for high-power broad-area lasers.Narodowe Centrum Nauki (2015/18/E/ST7/00572); German Research Foundation (Collaborative Research Center 787)

Practice management guideline on prehospital emergency anaesthesia. Working group Prehospital emergency anaesthesia of the scientific working group on emergency medicine of the German Society of Anaesthesiology and Intensive Care Medicine

Inducing anaesthesia outside the hospital is an important therapeutic intervention in emergency medicine; it is much more difficult to accomplish than inside the hospital. Its primary goals include hypnosis and analgesia which enable airway management to achieve mechanical ventilation and adequate oxygenation. Secondary goals of emergency anaesthesia include amnesia, anxiolysis, reduced oxygen consumption and work of breathing, and thus protection of vital organs and avoidance of secondary myocardial injury or cerebral injuries. Prior to prehospital induction of anaesthesia, patient-, scene- and operator-specific factors need to be considered. The rapid sequence induction includes basic monitoring, pre-oxygenation, standardized preparation of drugs and equipment, administration of drugs, removal of the cervical collar and manual in-line stabilization during intubation attempt (if needed), intubation and confirmation of endotracheal intubation. Every spontaneously breathing emergency patient should receive pre-oxygenation for at least 3-4 min with 12-15 l oxygen per min and a tight-sealing facemask, or a demand valve. The standardized preparation process includes preparation and labeling drugs/syringes, checking the bag-valve mask, preparing the endotracheal tube with a stylet and blocking syringe, as well as having a stethoscope and material to secure the tube at hand, as well as alternative airway devices. It also includes immediate access to alternative means of airway management, as well as a suction unit, ventilator and monitoring devices including capnography. Basic monitoring for prehospital emergency anaesthesia includes ECG, an automatic/manual blood pressure cuff, and pulse oximetry. Continuous capnography is used without exception to confirm ventilation, to detect possible disconnections/dislocations, and for indirect monitoring of hemodynamics. Prior to induction of prehospital emergency anaesthesia, two peripheral intravenous catheters should be placed if possible