Gesture2Path: Imitation Learning for Gesture-aware Navigation

As robots increasingly enter human-centered environments, they must not only be able to navigate safely around humans, but also adhere to complex social norms. Humans often rely on non-verbal communication through gestures and facial expressions when navigating around other people, especially in densely occupied spaces. Consequently, robots also need to be able to interpret gestures as part of solving social navigation tasks. To this end, we present Gesture2Path, a novel social navigation approach that combines image-based imitation learning with model-predictive control. Gestures are interpreted based on a neural network that operates on streams of images, while we use a state-of-the-art model predictive control algorithm to solve point-to-point navigation tasks. We deploy our method on real robots and showcase the effectiveness of our approach for the four gestures-navigation scenarios: left/right, follow me, and make a circle. Our experiments indicate that our method is able to successfully interpret complex human gestures and to use them as a signal to generate socially compliant trajectories for navigation tasks. We validated our method based on in-situ ratings of participants interacting with the robots.Comment: 8 pages, 12 figure

Hypoglycemic activity and the activation of phosphorylation of a triterpenoid-rich extract from Euryale shell on streptozotocin-induced diabetic mice

In the present study, we examined the hypoglycemic properties and the effective mechanisms of a triterpenoid-rich extract from the Euryale shell (ES) in streptozotocin-induced (STZ) diabetic mice. The hydroalcoholic extract of ES (200, 400 and 600 mg/kg/day) was orally administered to STZ-diabetic mice for 4 weeks. We observed that in the liver of diabetic mice, the ES extract caused a sharp reduction in the gene expression of protein tyrosine phosphatase-1B (PTP1B) but induced the gene expression of phosphatidyl-inositol-3-kinase (PI-3K) and protein kinase B (PKB) compared with that of untreated diabetic mice. Additionally, a significant increase in the phosphorylation of the PKB protein was observed (p<0.01). This was corroborated by the inhibition of PTP1B and by the regulation of glucose uptake via PI-3K activation, which together demonstrate that the reduction of PTP1B can modulate key insulin signaling events downstream of the insulin receptor.

A lanthanide functionalized MOF hybrid for ratiometric luminescence detection of an anthrax biomarker

Dipicolinic acid (DPA) can serve as a convenient biomarker for Bacillus anthracis, which is an extremely hazardous pathogen and can be used as a biological weapon. Herein, we demonstrate a ratiometric luminescent sensor of DPA based on a dual-emissive MOF hybrid, which is developed by encapsulation of Tb 3+ cations into an anionic MOF through a cation exchange process. The Tb 3+ @MOF hybrid well inherits the intrinsic ligand emission of the host framework and the Tb 3+ emission. The parent framework can function as a host matrix to sensitize and protect the emission of incorporated Tb 3+ . The Tb 3+ emission within the MOF hybrid is significantly enhanced in the presence of DPA molecules owing to the occurrence of antenna sensitization upon the formation of the Tb-DPA complex, while the ligand emission is insensitive to DPA. This unique ratiometric luminescence response of the Tb 3+ @MOF hybrid towards DPA can be exploited for sensitive self-calibrated detection of DPA. The Tb 3+ @MOF sensor shows a fast response rate, high sensitivity and selectivity with a limit of detection of 3.6 nM. Besides, the feasibility of this sensor operating in real samples is demonstrated by the good recovery of DPA in human serum. The present study provides a promising luminescent platform for routine analysis of an anthrax biomarker

A luminescent Lanthanide-free MOF nanohybrid for highly sensitive ratiometric temperature sensing in physiological range

Luminescent MOF materials with tunable emissions and energy/charge transfer processes have been extensively explored as ratiometric temperature sensors. However, most of the ratiometric MOF thermometers reported thus far are based on the MOFs containing photoactive lanthanides, which are potentially facing cost issue and serious supply shortage. Here, we present a ratiometric luminescent thermometer based on a dual-emitting lanthanide-free MOF hybrid, which is developed by encapsulation of a fluorescent dye into a robust nanocrystalline zirconium-based MOF through a one-pot synthesis approach. The structure and morphology of the hybrid product was characterized by Powder X-ray diffraction (PXRD), N 2 adsorption-desorption measurement and Scanning electron microscopy (SEM). The pore confinement effect well isolates the guest dye molecules and therefore suppresses the nonradiative energy transfer process between dye molecules. The incorporated dye emission is mainly sensitized by the organic linkers within MOF through fluorescence resonance energy transfer. The ratiometric luminescence of the MOF hybrid shows a significant response to temperature due to the thermal-related back energy transfer process from dye molecules and organic linkers, thus can be exploited for self-calibrated temperature sensing. The maximum thermometric sensitivity is 1.19% °C −1 in the physiological temperature range, which is among the highest for the ratiomtric MOF thermometers that operating in 25-45 °C. The temp erature resolution is better than 0.1 °C over the entire operative range (20-60 °C). By integrating the advantages of excellent stability, nanoscale nature, and high sensitivity and precision in the physiological temperature range, this dye@MOF hybrid might have potential application in biomedical diagnosis. What\u27 more, this work has expanded the possibility of non-lanthanide luminescent MOF materials for the development of ratiometric temperature sensors

Detection and removal of antibiotic tetracycline in water with a highly stable luminescent MOF

Antibiotic tetracycline (TC) is a sort of main contaminates in water, and of adverse effect on ecosystems and human health. The development of simple and efficient methods for both detection and removal of TC in water is highly desirable but remains challenging. Herein, a dual-functional platform for detection and removal of antibiotic tetracycline (TC) is developed by a highly stable luminescent zirconium-based MOF (PCN-128Y). The detection is based on the efficient luminescence quenching of the PCN-128Y toward TC. Theoretical/experimental studies reveal that the luminescence quenching can be attributed to a combined effect of the strong absorption of TC at the excitation wavelength and the photo-induced electron transfer process from the ligand of PCN-128Y to TC. The strong cheating metal-ligand bonding between Zr 6 nodes and TC through solvent-assisted ligand incorporation is suggested to mainly account for the high adsorption capability of PCN-128Y toward TC in water. The preconcentration of TC within the pores of PCN-128Y induced by the adsorption process makes TC contact with the framework more sufficient, thus significantly enhances the efficiency of TC sensing. This work is the first example demonstrating that MOF materials can integrate the functions of detection and removal of antibiotic TC in water, which highlights the opportunity of luminescent MOFs in the application of wastewater treatment

Ratiometric and Turn-On Luminescence Detection of Water in Organic Solvents Using a Responsive Europium-Organic Framework

The development of simple, rapid-response sensors for water detection in organic solvents is highly desirable in the chemical industry. Here we demonstrate a unique luminescence water sensor based on a dual-emitting europium-organic framework (Eu-MOF), which is assembled from a purposely selected 2-aminoterephthalic acid ligand with responsive fluorescence inherent in its intramolecular charge transfer (ICT) process. This ICT process can be rapidly switched-on in the presence of water owing to its ability to boost and stabilize the ICT state. In contrast, the Eu 3+ emission within the framework is insensitive to water and can serve as a reference, thus enabling highly sensitive water detection in a turn-on and ratiometric way. In addition, the significant ratiometric luminescence response induced by water makes Eu-MOF undergo a distinct change of emitting color from red to blue, which is favorable for visual analysis with the naked eye. Sensitive determination of water content (0.05-10% v/v) in various organic solvents is achieved in multiple readouts including ratiometric emission intensity, emission color, or the Commission Internationale de l\u27Eclairage (CIE) chromaticity coordinate. The present Eu-MOF sensor featuring high sensitivity and reusability, self-calibration, simple fabrication and operation, and capability for real-time and in situ detection is expected to have practical applications in water analysis for industrial processes

Application of Ecosystem Service Bundles and Tour Experience in Land Use Management: A Case Study of Xiaohuangshan Mountain (China)

With the deterioration of human-terrestrial relations and the intensification of global warming, development in all countries is facing difficulties. Whether in highly urbanized countries or in rapidly urbanizing developing countries such as China, the research on ecosystem services (ES) and land use management has attracted increasing attention. The general management of land use unilaterally pursues economic benefits and neglects ecological benefits, which aggravates the disparity between ecological development and the economic benefits of land resources. How to strike up a balance between ecologic protection and economic development remains a difficult problem during urbanization. It may be a better choice to formulate regional development strategies by combining natural conditions with humanistic and social tendencies. Identifying regional cultural ecosystem services (CES) and other important ES while performing zoning planning for regional land use can be a viable approach in land use management. Here, our study quantitatively evaluates the tourism experience of Xiaohuangshan Mountain (XHSM) and various ES, including recreation, biodiversity, history, aesthetics, soil conservation, surface water regulation, and soil nutrition. All ES were classified into four bundles for XHSM. Different ES bundles generated are suitable for different land use management methods and development forms according to their outstanding ES. The results show that quantifying and mapping regional ES bundles can provide the necessary information to support a win-win solution and provide decision support for land and spatial planning in areas with different social and ecological characteristics

Heterostructure Manipulation toward Ameliorating Electrodes for Better Lithium Storage Capability

As one of the major problems facing lithium ion batteries, sluggish charge transfer often induces undesirable large resistance, overpotential, and round trip inefficiency of batteries during recharge. The need to improve charge transport kinetics is motivating research into directions that would rely on high quality heterostructure designs, since it is reported that the synergistic effects and as-formed inbuilt electric fields of heterostructures could facilitate charge transport across the heterostructure, as well as enforce interactions between the active phases. Heteromanipulation holds great promise for realizing efficient interconnects between charge transport kinetics and heterostructure designs. However, most previous studies delineate ensemble measurements of a given static heteroelectrode, which do not permit isolating and dissecting the effects of heterostructural manipulation on electrochemical performances individually. Here, by choosing conversion type electrodes as an example and comparing series samples which were collected in the evolution of heterostructures, the effects of heterostructure manipulation toward modifying overpotential and lithium storage capability have been systematically investigated. The results demonstrate that structural features (e.g., robust skeleton, smaller grain sizes, and high quality hybridity) play an important role in engendering faster charge transfer and narrowing overpotential than that at the level of micrometer scales