Intelligent machines work in unstructured environments by differential neuromorphic computing

Efficient operation of intelligent machines in the real world requires methods that allow them to understand and predict the uncertainties presented by the unstructured environments with good accuracy, scalability and generalization, similar to humans. Current methods rely on pretrained networks instead of continuously learning from the dynamic signal properties of working environments and suffer inherent limitations, such as data-hungry procedures, and limited generalization capabilities. Herein, we present a memristor-based differential neuromorphic computing, perceptual signal processing and learning method for intelligent machines. The main features of environmental information such as amplification (>720%) and adaptation (<50%) of mechanical stimuli encoded in memristors, are extracted to obtain human-like processing in unstructured environments. The developed method takes advantage of the intrinsic multi-state property of memristors and exhibits good scalability and generalization, as confirmed by validation in two different application scenarios: object grasping and autonomous driving. In the former, a robot hand experimentally realizes safe and stable grasping through fast learning (in ~1 ms) the unknown object features (e.g., sharp corner and smooth surface) with a single memristor. In the latter, the decision-making information of 10 unstructured environments in autonomous driving (e.g., overtaking cars, pedestrians) is accurately (94%) extracted with a 40*25 memristor array. By mimicking the intrinsic nature of human low-level perception mechanisms, the electronic memristive neuromorphic circuit-based method, presented here shows the potential for adapting to diverse sensing technologies and helping intelligent machines generate smart high-level decisions in the real world.Comment: 16 pages, 5 figure

The elusive nature and diagnostics of misfolded Aβ oligomers.

Amyloid-beta (Aβ) peptide oligomers are believed to be the causative agents of Alzheimer's disease (AD). Though post-mortem examination shows that insoluble fibrils are deposited in the brains of AD patients in the form of intracellular (tangles) and extracellular (plaques) deposits, it has been observed that cognitive impairment is linked to synaptic dysfunction in the stages of the illness well before the appearance of these mature deposits. Increasing evidence suggests that the most toxic forms of Aβ are soluble low-oligomer ligands whose amounts better correlate with the extent of cognitive loss in patients than the amounts of fibrillar insoluble forms. Therefore, these ligands hold the key to a better understanding of AD prompting the search for clearer correlations between their structure and toxicity. The importance of such correlations and their diagnostic value for the early diagnosis of AD is discussed here with a particular emphasis on the transient nature and structural plasticity of misfolded Aβ oligomers

Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole

This is the author accepted manuscript. the final version is available from EDP Sciences via the DOI in this recordThe highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A∗ is a sensitive probe of the gravitational field in the Galactic centre. Near pericentre at 120 AU ≈ 1400 Schwarzschild radii, the star has an orbital speed of ≈ 7650 km s-1, such that the first-order effects of Special and General Relativity have now become detectable with current capabilities. Over the past 26 years, we have monitored the radial velocity and motion on the sky of S2, mainly with the SINFONI and NACO adaptive optics instruments on the ESO Very Large Telescope, and since 2016 and leading up to the pericentre approach in May 2018, with the four-telescope interferometric beam-combiner instrument GRAVITY. From data up to and including pericentre, we robustly detect the combined gravitational redshift and relativistic transverse Doppler effect for S2 of z = Δλ / λ ≈ 200 km s-1/c with different statistical analysis methods. When parameterising the post-Newtonian contribution from these effects by a factor f, with f = 0 and f = 1 corresponding to the Newtonian and general relativistic limits, respectively, we find from posterior fitting with different weighting schemes f = 0.90 ± 0.09|stat ± 0.15|sys. The S2 data are inconsistent with pure Newtonian dynamics

Multiple star systems in the Orion nebula

This is the author accepted manuscript. The final fersion is available from EDP Sciences via the DOI in this record.This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for θ1 Ori B, θ2 Ori B, and θ2 Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for θ1 Ori A, θ1 Ori C, θ1 Ori D, and θ2 Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary θ1 Ori C and we are able to derive a new orbit for θ1 Ori D. We find a system mass of 21.7 M⊙ and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.Marie Skłodowska-Curie Grant AgreementFCT-PortugalERC Starting Gran

The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge

Biochemical parameters, nutritional status and efficiency of dialysis in CAPD and CCPD patients

Background/Aims: Several studies indicate that small solute transport is influenced by peritoneal dialysate volume and dwell time. This study focuses on the clinical impact of peritoneal dialysis modality, continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD). Methods: We studied 18 patients on CAPD and 11 on CCPD for 18 months and assessed biochemical parameters, nutritional status and efficiency of dialysis at 6-month intervals. Results: Four-hour D/P urea and creatinine ratios were similar in both CAPD and CCPD patients. However, 24-hour D/P urea and creatinine ratios were significantly higher in CAPD than in CCPD patients (0.9 ± 0.1 vs. 0.8 ± 0.2 and 0.8 ± 0.1 vs. 0.6 ± 0.2, p \u3c 0.05 and p \u3c 0.01, respectively). The dialysate urea nitrogen concentration was significantly different between the two groups (65 ± 14 mg/dl in CAPD, 48 ± 13 mg/dl in CCPD; p \u3c 0.05). Total weekly Kt/V and total weekly creatinine clearance were not significantly different between CAPD and CCPD patients at 18 months (1.6 ± 0.4 vs. 1.7 ± 0.3 and 52 ± 21 vs. 50 ± 12 liters, respectively). Two-way ANOVA with a post-hoc Bonferroni-Dunn test showed serum potassium concentration was significantly lower in CCPD patients at 18 months (3.8 ± 0.5 mEq/l, p \u3c 0.05), and significant increases in triglyceride levels in the CAPD groups by 18 months (301 ± 286 mg/dl, p \u3c 0.05). Conclusion: This study demonstrates that the mean serum triglyceride level increases in CAPD patients over time, and the mean serum potassium concentration decreases in CCPD patients at 18 months. Dialysis adequacy and nutritional status are not significantly different between the two peritoneal dialysis modalities, CAPD and CCPD. We suggest the peritoneal dialysis prescription for CAPD or CCPD with respect to volume and frequency of exchanges be individualized to achieve adequate of therapy

The impact of residual renal function and total body water volume on achieving adequate dialysis in CAPD

Aims: The objective is to evaluate the impact of residual renal function (RRF) and total body water (TBW) on achieving adequate dialysis. Methods: Sixty three CAPD patients performing four 2 liter exchanges daily were evaluated for RRF, total weekly Kt/V (TWKt/V), total weekly creatinine clearance (TWCC) and TBW. Results: In patients with residual renal function (N = 41), TWKt/V and TWCC were 2.2 ± 0.8 and 77.4 ± 24.5 L, respectively. In patients without RRF (N = 22), TWKt/V was 1.6 ± 0.4 and TWCC 42.6 ± 9.2 L. TBW correlated negatively with TWKt/V in the group without RRF (r = -0.75, P\u3c0.001). Conclusion: It is not possible for larger patients without RRF treated with CAPD (2L x 4 exchanges) to achieve the acceptable targets for TWKt/V and TWCC due to TBW

C1QTNF6 Overexpression Acts as a Predictor of Poor Prognosis in Bladder Cancer Patients

Background. Bladder cancer is one of the most common urinary malignancies. This study is aimed at providing some promising molecular biomarkers for bladder cancer (BC) by investigating the correlation between C1QTNF6 expression and clinical characteristics as well as prognosis in patients with bladder cancer. Methods. Sequencing profiles of C1QTNF6 mRNA in BC patients were collected to evaluate the distinctive gene expression, between normal bladder mucosa and BC, according to the TCGA and GEO databases. The association between C1QTNF6 expression and the clinical features as well as the disease prognosis was evaluated using two independent cohorts. The expression of C1QTNF6 in normal bladder and BC cells was examined by western blotting and PCR, so the underlying molecular mechanism could be further investigated. Results. C1QTNF6 mRNA levels were found to be differentially expressed in two independent public cohorts, including the TCGA database and GSE13507 dataset from GEO. The protein and RNA levels of C1QTNF6 in BC cells were both elevated when compared to normal bladder cell lines. High C1QTNF6 expression was detected in advanced T/M stages, pathological grade, and AJCC stage when compared to the low C1QTNF6 expression group. The underlying mechanism related to this differential expression could be explained by cell migration and invasion assays, where bladder cancer cells 5637 and T24 had a significant reduction on migration and invasion ability upon knockdown of C1QTNF6 expression. The low C1QTNF6 expression group presented a more prominent OS advantage over the high-expression group in both TCGA and GSE13507 cohorts. Moreover, the protein content in tissues was further validated using the HPA database and TMA. Survival analyses also indicated that the high C1QTNF6 expression group had an unfavorable OS when compared to the low-expression group. Conclusions. High C1QTNF6 expression may serve as a predictor of poor prognosis in bladder cancer patients, and the underlying mechanism is possibly associated with changes on cancer cell migration and invasion ability