Strain-Tunable GaAs Quantum dot: A Nearly Dephasing-Free Source of Entangled Photon Pairs on Demand

Entangled photon generation from semiconductor quantum dots via the biexciton-exciton cascade underlies various decoherence mechanisms related to the solid-state nature of the quantum emitters. So far, this has prevented the demonstration of nearly-maximally entangled photons without the aid of inefficient and complex post-selection techniques that are hardly suitable for quantum communication technologies. Here, we tackle this challenge using strain-tunable GaAs quantum dots driven under two-photon resonant excitation and with strictly-degenerate exciton states. We demonstrate experimentally that our on-demand source generates polarization-entangled photons with fidelity of 0.978(5) and concurrence of 0.97(1) without resorting to post-selection techniques. Moreover, we show that the remaining decoherence mechanisms can be overcome using a modest Purcell enhancement so as to achieve a degree of entanglement >0.99. Our results highlight that GaAs quantum dots can be readily used in advanced communication protocols relying on the non-local properties of quantum entanglement

Options for re-establishing river continuity, with an emphasis on the special solution “fish lift”: examples from Austria.

The European Water Framework Directive (WFD) became a major tool in European water policy. All the member states had to develop River Basin Management Plans (RBMPs). Austria’s first National Water Resource Management Plan was published in 2009 and describes measures to be set. Depending on the catchment size, ecological targets were defined on water body level, to be reached by 2015, 2021 or 2027. A priority goal is the re-establishment of river continuity. Therefore the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management published a “Guideline for the construction of fish passes” in 2012.We provide an overview on measures to re-establish river continuity that were recently planned or already established at the Inn catchment, a major tributary to the upper Danube River. Planning principles as well as details from the construction phase and monitoring concepts as well as first results are presented.Founded in 1924 TIWAG started its business with the construction of the HPP Achensee, at the time one of Europe’s largest storage facilities. Since then TIWAG expanded its expertise on engineering, constructing and operating hydro power plants in Tyrol. In the first river basin management cycle at three hydropower plants, located in the“priority river network” (HPP Langkampfen, HPP Kirchbichl and HPP Imst - the latter with the weir Runserau and the water intake at Wenns), measures had to be developed to overcome discontinuity. During planning phase it was tried to apply “standard solutions” according to the Austrian guideline. This was possible for three sites, where we planned vertical slot fish passes in combination with natural bypass channels. To enable upstream migration at the weir Runserau, different alternatives were evaluated, but it was not possible to use a “standard solution”. A  review about existing fish lifts was the basis for a promising solution. The chosen design combines a conventional fish migration facility (vertical slot) with a fish lift. Linked together those facilities are offering new, additional possibilities. The characteristics of this new concept and its advantages are presented.</p

Lysosomal acid lipase regulates VLDL synthesis and insulin sensitivity in mice

AIMS/HYPOTHESIS: Lysosomal acid lipase (LAL) hydrolyses cholesteryl esters and triacylglycerols (TG) within lysosomes to mobilise NEFA and cholesterol. Since LAL-deficient (Lal (-/-) ) mice suffer from progressive loss of adipose tissue and severe accumulation of lipids in hepatic lysosomes, we hypothesised that LAL deficiency triggers alternative energy pathway(s). METHODS: We studied metabolic adaptations in Lal (-/-) mice. RESULTS: Despite loss of adipose tissue, Lal (-/-) mice show enhanced glucose clearance during insulin and glucose tolerance tests and have increased uptake of [(3)H]2-deoxy-D-glucose into skeletal muscle compared with wild-type mice. In agreement, fasted Lal (-/-) mice exhibit reduced glucose and glycogen levels in skeletal muscle. We observed 84% decreased plasma leptin levels and significantly reduced hepatic ATP, glucose, glycogen and glutamine concentrations in fed Lal (-/-) mice. Markedly reduced hepatic acyl-CoA concentrations decrease the expression of peroxisome proliferator-activated receptor α (PPARα) target genes. However, treatment of Lal (-/-) mice with the PPARα agonist fenofibrate further decreased plasma TG (and hepatic glucose and glycogen) concentrations in Lal (-/-) mice. Depletion of hepatic nuclear factor 4α and forkhead box protein a2 in fasted Lal (-/-) mice might be responsible for reduced expression of microsomal TG transfer protein, defective VLDL synthesis and drastically reduced plasma TG levels. CONCLUSIONS/INTERPRETATION: Our findings indicate that neither activation nor inactivation of PPARα per se but rather the availability of hepatic acyl-CoA concentrations regulates VLDL synthesis and subsequent metabolic adaptations in Lal (-/-) mice. We conclude that decreased plasma VLDL production enhances glucose uptake into skeletal muscle to compensate for the lack of energy supply

Autism spectrum disorder classification based on interpersonal neural synchrony: Can classification be improved by dyadic neural biomarkers using unsupervised graph representation learning?

Research in machine learning for autism spectrum disorder (ASD) classification bears the promise to improve clinical diagnoses. However, recent studies in clinical imaging have shown the limited generalization of biomarkers across and beyond benchmark datasets. Despite increasing model complexity and sample size in neuroimaging, the classification performance of ASD remains far away from clinical application. This raises the question of how we can overcome these barriers to develop early biomarkers for ASD. One approach might be to rethink how we operationalize the theoretical basis of this disease in machine learning models. Here we introduced unsupervised graph representations that explicitly map the neural mechanisms of a core aspect of ASD, deficits in dyadic social interaction, as assessed by dual brain recordings, termed hyperscanning, and evaluated their predictive performance. The proposed method differs from existing approaches in that it is more suitable to capture social interaction deficits on a neural level and is applicable to young children and infants. First results from functional near-infrared spectroscopy data indicate potential predictive capacities of a task-agnostic, interpretable graph representation. This first effort to leverage interaction-related deficits on neural level to classify ASD may stimulate new approaches and methods to enhance existing models to achieve developmental ASD biomarkers in the future.Comment: Accepted in Medical Image Computing and Computer Assisted Intervention - MICCAI 2022: The 5th International Workshop on Machine Learning in Clinical Neuroimagin

Tissue-Specific Orchestration of Gilthead Sea Bream Resilience to Hypoxia and High Stocking Density

Two different O-2 levels (normoxia: 75-85% O-2 saturation; moderate hypoxia: 42-43% O-2 saturation) and stocking densities (LD: 9.5, and HD: 19 kg/m(3)) were assessed on gilthead sea bream (Sparus aurata) in a 3-week feeding trial. Reduced O-2 availability had a negative impact on feed intake and growth rates, which was exacerbated by HD despite of the improvement in feed efficiency. Blood physiological hallmarks disclosed the enhancement in O-2-carrying capacity in fish maintained under moderate hypoxia. This feature was related to a hypo-metabolic state to cope with a chronic and widespread environmental O-2 reduction, which was accompanied by a differential regulation of circulating cortisol and growth hormone levels. Customized PCR-arrays were used for the simultaneous gene expression profiling of 34-44 selected stress and metabolic markers in liver, white skeletal muscle, heart, and blood cells. The number of differentially expressed genes ranged between 22 and 19 in liver, heart, and white skeletal muscle to 5 in total blood cells. Partial Least-Squares Discriminant Analysis (PLS-DA) explained [R2Y(cum)] and predicted [Q2Y(cum)] up to 95 and 65% of total variance, respectively. The first component (R2Y = 0.2889) gathered fish on the basis of O-2 availability, and liver and cardiac genes on the category of energy sensing and oxidative metabolism (cs, hif-1 alpha, pgc1 alpha, pgc1 beta, sirts 1-2-4-5-6-7), antioxidant defense and tissue repair (prdx5, sod2, mortalin, gpx4, gr, grp-170, and prdx3) and oxidative phosphorylation (nd2, nd5, and coxi) highly contributed to this separation. The second component (R2Y = 0.2927) differentiated normoxic fish at different stocking densities, and the white muscle clearly promoted this separation by a high over-representation of genes related to GH/IGF system (ghr-i, igfbp6b, igfbp5b, insr, igfbp3, and igf-i). The third component (R2Y = 0.2542) discriminated the effect of stocking density in fish exposed to moderate hypoxia by means of hepatic fatty acid desaturases (fads2, scd1a, and scd1b) and muscle markers of fatty acid oxidation (cpt1a). All these findings disclose the different contribution of analyzed tissues (liver >= heart > muscle > blood) and specific genes to the hypoxic- and crowding stress-mediated responses. This study will contribute to better explain and understand the different stress resilience of farmed fish across individuals and species

Serendipitous alkylation of a Plk1 ligand uncovers a new binding channel

We obtained unanticipated synthetic byproducts from alkylation of the δ[superscript 1] nitrogen (N3) of the histidine imidazole ring of the polo-like kinase-1 (Plk1) polo-box domain (PBD)-binding peptide PLHSpT. For the highest-affinity byproduct, bearing a C[subscript 6]H[subscript 5](CH[subscript 2])[subscript 8]– group, a Plk1 PBD cocrystal structure revealed a new binding channel that had previously been occluded. An N-terminal PEGylated version of this peptide containing a hydrolytically stable phosphothreonyl residue (pT) bound the Plk1 PBD with affinity equal to that of the non-PEGylated parent but showed markedly less interaction with the PBDs of the two closely related proteins Plk2 and Plk3. Treatment of cultured cells with this PEGylated peptide resulted in delocalization of Plk1 from centrosomes and kinetochores and in chromosome misalignment that effectively induced mitotic block and apoptotic cell death. This work provides insights that might advance efforts to develop Plk1 PBD-binding inhibitors as potential Plk1-specific anticancer agents.National Institutes of Health (U.S.) (Grant GM60594)National Institutes of Health (U.S.) (Grant GM68762)National Institutes of Health (U.S.) (Grant CA112967

Nogo receptor is involved in the adhesion of dendritic cells to myelin

BACKGROUND: Nogo-66 receptor NgR1 and its structural homologue NgR2 are binding proteins for a number of myelin-associated inhibitory factors. After neuronal injury, these inhibitory factors are responsible for preventing axonal outgrowth via their interactions with NgR1 and NgR2 expressed on neurons. In vitro, cells expressing NgR1/2 are inhibited from adhering to and spreading on a myelin substrate. Neuronal injury also results in the presence of dendritic cells (DCs) in the central nervous system, where they can come into contact with myelin debris. The exact mechanisms of interaction of immune cells with CNS myelin are, however, poorly understood. METHODS: Human DCs were differentiated from peripheral blood monocytes and mouse DCs were differentiated from wild type and NgR1/NgR2 double knockout bone marrow precursors. NgR1 and NgR2 expression were determined with quantitative real time PCR and immunoblot, and adhesion of cells to myelin was quantified. RESULTS: We demonstrate that human immature myeloid DCs express NgR1 and NgR2, which are then down-regulated upon maturation. Human mature DCs also adhere to a much higher extent to a myelin substrate than immature DCs. We observe the same effect when the cells are plated on Nogo-66-His (binding peptide for NgR1), but not on control proteins. Mature DCs taken from Ngr1/2 knockout mice adhere to a much higher extent to myelin compared to wild type mouse DCs. In addition, Ngr1/2 knockout had no effect on in vitro DC differentiation or phenotype. CONCLUSIONS: These results indicate that a lack of NgR1/2 expression promotes the adhesion of DCs to myelin. This interaction could be important in neuroinflammatory disorders such as multiple sclerosis in which peripheral immune cells come into contact with myelin debris

Fibroblast growth factor 23 is related to profiles indicating volume overload, poor therapy optimization and prognosis in patients with new-onset and worsening heart failure

Background: Fibroblast growth factor (FGF) 23 is a hormone that increases urinary phosphate excretion and regulates renal sodium reabsorption and plasma volume. We studied the role of plasma FGF23 in therapy optimization and outcomes in patients with new-onset and worsening heart failure (HF). Methods: We measured plasma C-terminal FGF23 levels at baseline in 2399 of the 2516 patients included in the BIOlogy Study to Tailored Treatment in Chronic HF (BIOSTAT-CHF) trial. The association between FGF23 and outcome was evaluated by Cox regression analysis adjusted for potential confounders. Results: Median FGF23 was 218.0 [IQR: 117.1–579.3] RU/ml; patients with higher FGF23 levels had a worse NYHA class, more signs of congestion, and were less likely to use an ACE-inhibitor (ACEi) or angiotensin receptor blocker (ARBs) at baseline (all P &lt; 0.01). Higher FGF23 levels were independently associated with higher BNP, lower eGFR, the presence of oedema and atrial fibrillation (all P &lt; 0.001). In addition, higher FGF23 was independently associated with impaired uptitration of ACEi/ARBs after 3 months, but not of beta-blockers. In multivariable Cox regression analysis, FGF23 was independently associated with all-cause mortality (hazard ratio: 1.17 (1.09–1.26) per log increase, P &lt; 0.001), and the combined endpoint of all-cause mortality and HF hospitalization (1.15 (1.08–1.22) per log increase, P &lt; 0.001). Conclusions: In patients with new-onset and worsening HF, higher plasma FGF23 levels were independently associated with volume overload, less successful uptitration of ACEi/ARBs and an increased risk of all-cause mortality and HF hospitalization

SatSel: A Satellite Selection Algorithm to reduce delivery time in DTN-Nanosatellite Networks for Internet Access in Rural Areas.

There are some different ways to connect rural areas to the Internet. One of these provides the use of a nanosatellite constellation. This type of network allows people in rural areas to enjoy all services the Internet can offer keeping low the cost of Internet access. One of the critical aspect is related to the delivery time, because LEO satellite links are not always up. This means that the system must be able to deal with periodic disruptions and high delays in the path from the source to the destination, considering that data could be stored in nanosatellite, Internet gateway (also called hot spot), and rural gateway (also called cold spot) buffers also for several seconds or minutes waiting to be forwarded. In the path from rural areas to the Internet, it is possible to reduce data delivery time acting on rural gateways. We propose SatSel: a selection algorithm which allows the cold spots to choose the nanosatellite to whom upload data in order to reduce the data delivery tim