Legged Robots for Object Manipulation: A Review

Legged robots can have a unique role in manipulating objects in dynamic, human-centric, or otherwise inaccessible environments. Although most legged robotics research to date typically focuses on traversing these challenging environments, many legged platform demonstrations have also included "moving an object" as a way of doing tangible work. Legged robots can be designed to manipulate a particular type of object (e.g., a cardboard box, a soccer ball, or a larger piece of furniture), by themselves or collaboratively. The objective of this review is to collect and learn from these examples, to both organize the work done so far in the community and highlight interesting open avenues for future work. This review categorizes existing works into four main manipulation methods: object interactions without grasping, manipulation with walking legs, dedicated non-locomotive arms, and legged teams. Each method has different design and autonomy features, which are illustrated by available examples in the literature. Based on a few simplifying assumptions, we further provide quantitative comparisons for the range of possible relative sizes of the manipulated object with respect to the robot. Taken together, these examples suggest new directions for research in legged robot manipulation, such as multifunctional limbs, terrain modeling, or learning-based control, to support a number of new deployments in challenging indoor/outdoor scenarios in warehouses/construction sites, preserved natural areas, and especially for home robotics.Comment: Preprint of the paper submitted to Frontiers in Mechanical Engineerin

Exploring the Protective Effects and Mechanism of Crocetin From Saffron Against NAFLD by Network Pharmacology and Experimental Validation

Background: Non-alcoholic fatty liver disease (NAFLD) is a burgeoning health problem but no drug has been approved for its treatment. Animal experiments and clinical trials have demonstrated the beneficial of saffron on NAFLD. However, the bioactive ingredients and therapeutic targets of saffron on NAFLD are unclear.Purpose: This study aimed to identify the bioactive ingredients of saffron responsible for its effects on NAFLD and explore its therapy targets through network pharmacology combined with experimental tests.Methods: Various network databases were searched to identify bioactive ingredients of saffron and identify NAFLD-related targets. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were conducted to enrich functions and molecular pathways of common targets and the STRING database was used to establish a protein-protein interaction network (PPI). The effect of crocetin (CCT) on NAFLD was evaluated in a mouse model of NAFLD by measuring the biomarkers of lipid, liver and renal function, oxidative stress, and inflammation. Liver histopathology was performed to evaluate liver injury. Nuclear factor erythroid-related factor (Nrf2) and hemeoxygenase-1 (HO-1) were examined to elucidate underlying mechanism for the protective effect of saffron against NAFLD.Results: A total of nine bioactive ingredients of saffron, including CCT, with 206 common targets showed therapeutic effects on NAFLD. Oxidative stress and diabetes related signaling pathways were identified as the critical signaling pathways mediating the therapeutic effects of the active bioactive ingredients on NAFLD. Treatment with CCT significantly reduced the activities of aspartate aminotransferase (AST), alanine transaminase (ALT), and the levels of total cholesterol (TC), triglyceride (TG), malondialdehyde (MDA), blood urea nitrogen (BUN), creatinine (CR), and uric acid (UA). CCT significantly increased the activities of superoxide dismutase (SOD), and catalase (CAT). Histological analysis showed that CCT suppressed high-fat diet (HFD) induced fat accumulation, steatohepatitis, and renal dysfunctions. Results of ELISA assay showed that CCT decreased the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and increased the expression of HO-1 and Nrf2.Conclusion: This study shows that CCT is a potential bioactive ingredient of saffron that treats NAFLD. Its mechanism of action involves suppressing of oxidative stress, mitigating inflammation, and upregulating Nrf2 and HO-1 expression

ABO genotype alters the gut microbiota by regulating GalNAc levels in pigs.

peer reviewedThe composition of the intestinal microbiome varies considerably between individuals and is correlated with health1. Understanding to what extend and how host genetics contributes to this variation is paramount yet has proven difficult as few associations have been replicated, particularly in humans2. We herein study the effect of host genotype on the composition of the intestinal microbiota in a large mosaic pig population. We show that, under conditions of exacerbated genetic diversity and environmental uniformity, microbiota composition and abundance of specific taxa are heritable. We map a quantitative trait locus affecting the abundance of Erysipelotrichaceae species and show that it is caused by a 2.3-Kb deletion in the N-acetyl-galactosaminyl-transferase gene underpinning the ABO blood group in humans. We show that this deletion is a ≥3.5 million years old trans-species polymorphism under balancing selection. We demonstrate that it decreases the concentrations of N-acetyl-galactosamine in the gut thereby reducing the abundance of Erysipelotrichaceae that can import and catabolize N-acetyl-galactosamine. Our results provide very strong evidence for an effect of host genotype on the abundance of specific bacteria in the intestine combined with insights in the molecular mechanisms that underpin this association. They pave the way towards identifying the same effect in human rural populations

Evaluating Impact of Farmland Recessive Morphology Transition on High-Quality Agricultural Development in China

Recessive morphology transition (RMT) involves the smooth transition of farmland property rights, input structure, quality, and function. China’s agriculture has changed from a period of high-speed growth to a period of high-quality development. Compared with dominant morphology transition (DMT) characterized by quantitative focus, it is of more practical significance to explore the impact of RMT on high-quality agricultural development (HAD). This paper firstly constructed a multidimensional index system to quantify HAD. Based on analysis of the impact mechanism of RMT on HAD, a spatial econometric model was established to explore the impact by making use of the panel data of 27 provinces in China from 2003–2017. The results indicated that RMT and HAD both have positive geospatial correlation. Furthermore, the spatial econometric model provides more accurate results of the impact of RMT on HAD than panel models. If the RMT in a local province increases by 1%, HAD could be augmented by 0.13%. Likewise, RMT has a strong positive spatial spillover effect on HAD. If the RMT in a certain province increases by 1%, HAD could add 1.22% in neighboring provinces. The analysis suggests that spatial coordination of farmland use is an important foundation for constructing high-quality development association of regional agriculture. It is necessary to strengthen intergovernmental cooperation in the process of farmland recessive morphology transition and high-quality agricultural development

Evaluating Impact of Farmland Recessive Morphology Transition on High-Quality Agricultural Development in China

Recessive morphology transition (RMT) involves the smooth transition of farmland property rights, input structure, quality, and function. China’s agriculture has changed from a period of high-speed growth to a period of high-quality development. Compared with dominant morphology transition (DMT) characterized by quantitative focus, it is of more practical significance to explore the impact of RMT on high-quality agricultural development (HAD). This paper firstly constructed a multidimensional index system to quantify HAD. Based on analysis of the impact mechanism of RMT on HAD, a spatial econometric model was established to explore the impact by making use of the panel data of 27 provinces in China from 2003–2017. The results indicated that RMT and HAD both have positive geospatial correlation. Furthermore, the spatial econometric model provides more accurate results of the impact of RMT on HAD than panel models. If the RMT in a local province increases by 1%, HAD could be augmented by 0.13%. Likewise, RMT has a strong positive spatial spillover effect on HAD. If the RMT in a certain province increases by 1%, HAD could add 1.22% in neighboring provinces. The analysis suggests that spatial coordination of farmland use is an important foundation for constructing high-quality development association of regional agriculture. It is necessary to strengthen intergovernmental cooperation in the process of farmland recessive morphology transition and high-quality agricultural development

Mutations of the TGFBR2 gene in Chinese patients with Marfan-related syndrome

Purpose: Transforming growth factor beta receptors II gene (TGFBR2) mutations associated with Marfan syndrome and Marfan-associated disorders have been investigated. However, such studies are limited in China. To obtain more information about TGFBR2 mutations, we analyzed 6 unrelated Chinese patients with Marfan-associated disorders and without ocular manifestation. Methods: The genomic DNA from blood leukocytes of these 6 patients and their relatives was isolated, and the entire coding region of TGFBR2 was amplified using PCR. We determined the sequence of TGFBR2 with the ABI 3100 Genetic Analyzer. Results: Three mutations were identified in TGFBR2. Two mutations were associated with Loeys-Dietz syndrome (LDS), which were distributed as following: one missense mutation R528C (caused by a 1582C > T substitution) and one polymorphism T315M (a rare SNP). The third mutation was a novel silent mutation associated with MFS2, which was K291K caused by an 873 C > T substitution. Conclusions: The TGFBR2 gene missense mutations are possibly causative mutations of Loeys-Dietz syndrome. This result suggests an increase in the mutation spectrum of Marfan-related disorders in China and possibly world-wide