Classical Conformal Blocks and Painleve VI

We study the classical c\to \infty limit of the Virasoro conformal blocks. We point out that the classical limit of the simplest nontrivial null-vector decoupling equation on a sphere leads to the Painleve VI equation. This gives the explicit representation of generic four-point classical conformal block in terms of the regularized action evaluated on certain solution of the Painleve VI equation. As a simple consequence, the monodromy problem of the Heun equation is related to the connection problem for the Painleve VI.Comment: 19 pages, 5 figures; references adde

MASK4D: Mask Transformer for 4D Panoptic Segmentation

Accurately perceiving and tracking instances over time is essential for the decision-making processes of autonomous agents interacting safely in dynamic environments. With this intention, we propose Mask4D for the challenging task of 4D panoptic segmentation of LiDAR point clouds. Mask4D is the first transformer-based approach unifying semantic instance segmentation and tracking of sparse and irregular sequences of 3D point clouds into a single joint model. Our model directly predicts semantic instances and their temporal associations without relying on any hand-crafted non-learned association strategies such as probabilistic clustering or voting-based center prediction. Instead, Mask4D introduces spatio-temporal instance queries which encode the semantic and geometric properties of each semantic tracklet in the sequence. In an in-depth study, we find that it is critical to promote spatially compact instance predictions as spatio-temporal instance queries tend to merge multiple semantically similar instances, even if they are spatially distant. To this end, we regress 6-DOF bounding box parameters from spatio-temporal instance queries, which is used as an auxiliary task to foster spatially compact predictions. Mask4D achieves a new state-of-the-art on the SemanticKITTI test set with a score of 68.4 LSTQ, improving upon published top-performing methods by at least +4.5%.Comment: Project page: https://vision.rwth-aachen.de/mask4

Femtomolar detection of the heart failure biomarker NT-proBNP in artificial saliva using an immersible liquid-gated aptasensor with reduced graphene oxide

Measuring NT-proBNP biomarker is recommended for preliminary diagnostics of the heart failure. Recent studies suggest a possibility of early screening of biomarkers in saliva for non-invasive identification of cardiac diseases at the point-of-care. However, NT-proBNP concentrations in saliva can be thousand time lower than in blood plasma, going down to pg/mL level. To reach this level, we developed a label-free aptasensor based on a liquid-gated field effect transistor using a film of reduced graphene oxide monolayer (rGO-FET) with immobilized NT-proBNP specific aptamer. We found that, depending on ionic strength of tested solutions, there were different levels of correlation in responses of electrical parameters of the rGO-FET aptasensor, namely, the Dirac point shift and transconductance change. The correlation in response to NT-proBNP was high for 1.6 mM phosphate-buffered saline (PBS) and zero for 16 mM PBS in a wide range of analyte concentrations, varied from 1 fg/mL to 10 ng/mL. The effects of transconductance and Dirac point shift in PBS solutions of different concentrations are discussed. The biosensor exhibited a high sensitivity for both transconductance (2 uS/decade) and Dirac point shift (2.3 mV/decade) in diluted PBS with the linear range from 10 fg/mL to 1 pg/mL. The aptasensor performance has been also demonstrated in undiluted artificial saliva with the achieved limit of detection down to 41 fg/mL (~4.6 fM)

The effect of empagliflozin on the development of chronic heart failure after myocardial infarction according to a 12-month prospective study

BACKGROUND: Although the positive cardiovascular effect of empagliflozin has been established, its influence on the formation of heart failure (HF) in patients with type 2 diabetes mellitus (T2D) after myocardial infarction (MI) remains unknown. AIM: To study the effect of empagliflozin on the formation of chronic HF after MI in patients having diabetes mellitus of type 2 (DM 2), according to 12-month follow-up data. MATERIALS AND METHODS: 47 patients with MI and DM 2 were included; 21 received standard therapy for MI and diabetes (group 1); 26 patients, in addition, received empagliflozin (group 2). The patients were investigated in 3 and 12 months, to assess the dynamics of glycemic control, 6-minute walk test, echocardiography. RESULTS: During postinfarction period, the 6-minute walk distance was increasing in group 1 in a lesser degree (p = 0.18) than in group 2 (49.5%, p = 0.0004). The ejection fraction got better particularly in group 2 (p = 0.002). At baseline, the proportions of patients having HF with reduced and mid-range ejection fraction were 85.7% and 82.4% in groups 1 and 2 (p = 0.56) but in 12 months decreased to 71.4% and 29.4% (p = 0.012). In empagliflozin group diastolic function was improved in a third of the patients (p = 0.041). The pulmonary artery systolic pressure was increasing in group 1 (by 10,4%, p = 0.041) but decreasing in group 2 (by 24,0%, p = 0.019). Glycemic control was better in group 2 than in group 1. CONCLUSION: According to 12-month follow-up data, empagliflozin has a positive effect on HF formation and symptoms in patients having MI and DM 2. This effect may be based on the ability of empagliflozin to improve the state of the heart including the delay of postinfarction remodeling, the improvement of pulmonary artery hemodynamics, systolic and diastolic function, the reduction of risk of chronic HF with reduced and mid-range ejection fraction

Sea Surface Wind Measurement by Airborne Weather Radar Scanning in a Wide-Size Sector

We suggest a conceptual approach for measuring the near-surface wind vector over water using the airborne weather radar, in addition to its standard meteorological and navigation applications. The airborne weather radar operates in the ground-mapping mode in the range of high to medium incidence angles as a scatterometer. Using the aircraft rectilinear flight over the water surface, measuring the geometry and the geophysical model function, we show that the wind vector can be successfully recovered from the azimuth normalized radar cross-section data obtained from a scanning sector of up to ±100°. The efficiency and accuracy of the proposed wind vector measurement algorithms are supported by computer simulations indicating their potential as a powerful tool for the wind field reconstruction. Some limitations and recommendations of the suggested approach are further discussed

Doppler Navigation System with a Non-Stabilized Antenna as a Sea-Surface Wind Sensor

We propose a concept of the utilization of an aircraft Doppler Navigation System (DNS) as a sea-surface wind sensor complementary to its normal functionality. The DNS with an antenna, which is non-stabilized physically to the local horizontal with x-configured beams, is considered. We consider the wind measurements by the DNS configured in the multi-beam scatterometer mode for a rectilinear flight scenario. The system feasibility and the efficiency of the proposed wind algorithm retrieval are supported by computer simulations. Finally, the associated limitations of the proposed approach are considered

Integrated Architectural Approach to Ensuring Stability of Processes of the Digital Supply Chain

The revolutionary changes in the creation of platform-type models and strategies within the framework of Industry 4.0 have created new potential for the development of the economy and transport. The central place in the management of the digital supply chain (DSC) belongs to the models, structure and architecture of the system based on self-governing links - competence centers (CCs). The selected model for managing the system’s life cycle allows for more effective management of the central processing center at all stages through the integration of business processes and digital technologies, which allows for an integrated approach, simplifying the system itself and increasing its performance. The term «organizational and technical sustainability» (OTS) is introduced in the article, which implies a balanced location of the DSC between control points at the stage of the life cycle. The proposed approach is focused on the use of the mechanism of «homeokinetic plateau». The homeokinetic plateau is the basic cybernetic mechanism for ensuring the state of dynamic stability of the system. As critical points characterizing the state of stability, a combination of the probability of the implementation of processes and their profitability with the identification of risk options for the life cycle stage is considered. The mechanism of the homeokinetic plateau and tools considered in the article forms the structure of a comprehensive architectural approach, focused on innovative approaches to ensure stability and control of the continuity of the central processing center processes