Extreme Parkour with Legged Robots

Humans can perform parkour by traversing obstacles in a highly dynamic fashion requiring precise eye-muscle coordination and movement. Getting robots to do the same task requires overcoming similar challenges. Classically, this is done by independently engineering perception, actuation, and control systems to very low tolerances. This restricts them to tightly controlled settings such as a predetermined obstacle course in labs. In contrast, humans are able to learn parkour through practice without significantly changing their underlying biology. In this paper, we take a similar approach to developing robot parkour on a small low-cost robot with imprecise actuation and a single front-facing depth camera for perception which is low-frequency, jittery, and prone to artifacts. We show how a single neural net policy operating directly from a camera image, trained in simulation with large-scale RL, can overcome imprecise sensing and actuation to output highly precise control behavior end-to-end. We show our robot can perform a high jump on obstacles 2x its height, long jump across gaps 2x its length, do a handstand and run across tilted ramps, and generalize to novel obstacle courses with different physical properties. Parkour videos at https://extreme-parkour.github.io/Comment: Website and videos at https://extreme-parkour.github.io

Transforming Research on Recreational Ecosystem Services into Applications and Governance

The science-practice gap has recently been discussed as a critical challenge restricting sustainable growth and development in all facets of our society, including explorations of Recreation Ecosystem Services (RES). To better explore how well the scientific study of RES and its application are connected, this paper aims to synthesize empirical evidence based on an in-depth and systematic literature review. We found that studies of RES have not effectively transformed into the decision-making and long-term planning of our cities. From 2005 to 2020, only 13% of studies referred to specific applications, and about 40% of papers mentioned no applications or practical implications for their research. However, RES research has many potential applications, which can be categorised into six main aspects. In terms of non-spatial improvement: Improved monetary benefits (40%), non-monetary benefits (30%); in terms of spatial improvement: space with high recreational potential or degradation (7%), the relation between supply and demand (7%); and Cross-service governance (16%). After combining the results of various studies, we developed a framework starting from applicable problems and their solutions, which can incorporate the outcomes of RES research while systematically narrowing down the research questions and methods. The framework offers a starting point for further research that can modify and improve in bridging science-practice gaps in RES studies.National Natural Science Foundation of ChinaPeer Reviewe

A Class of Weighted Low Rank Approximation of the Positive Semidefinite Hankel Matrix

We consider the weighted low rank approximation of the positive semidefinite Hankel matrix problem arising in signal processing. By using the Vandermonde representation, we firstly transform the problem into an unconstrained optimization problem and then use the nonlinear conjugate gradient algorithm with the Armijo line search to solve the equivalent unconstrained optimization problem. Numerical examples illustrate that the new method is feasible and effective

Multidimensional study of cell division cycle-associated proteins with prognostic value in gastric carcinoma

Gastric cancer (GC) represents a widespread malignancy with a poor prognosis. Hence, discovering reliable biomarkers is necessary. The cell division cycle-associated protein (CDCA) family, comprising CDCA1–8, plays a key role in tumor progression. However, whether CDCA expression has prognostic value in GC, especially stomach adenocarcinoma (STAD), has not been elucidated yet. Consequently, we conducted a multifaceted study using bioinformatic tools aimed at exploring CDCA expression levels and appraising their potential prognostic values in patients with STAD. All eight CDCAs were significantly upregulated in STAD tissues compared with healthy tissues. Elevated CDCA4/7/8 mRNA expression predicted a short overall survival, and increased CDCA7 transcriptional levels predicted a short disease-free survival. The most frequent alteration in patients with STAD was low mRNA expression. The functional enrichment analysis incorporating the gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways showed that the cell cycle, foxO signaling pathway, and Epstein–Barr virus were relevant to the main functions of CDCAs. Finally, the immune infiltration analysis revealed a significant correlation between CDCA expression and the infiltration extent of six immunocytes. Therefore, differentially expressed CDCAs may represent potential biomarkers for the prognosis of patients with STAD that can improve survival. Furthermore, this study might offer new ideas for the design and development of immunotherapeutic drugs

25(OH)VitD and human endocrine and functional fertility parameters in women undergoing IVF/ICSI

Background: Vitamin D plays an important role in reproduction. Evidence shown that free 25-hydroxyvitamin D (25(OH)VitD) was more accurate than total 25(OH)VitD in reflecting the status of 25(OH)VitD during pregnancy. However, the relationship between free 25(OH)VitD and female fertility parameters has not been reported yet. Therefore, this study aims to compare the correlation of free and total 25(OH)VitD with fertility parameters in infertility females undergoing in vitro fertilization and embryo transfer (IVF-ET) or intracytoplasmic sperm injection (ICSI). Methods: According to the inclusion and exclusion criteria, 2569 infertility patients who received IVF-ET or ICSI treatment for the first time participated in this study. Five milliliter peripheral blood samples of the patients were collected on the day before embryo transfer (ET). Enzyme linked immunosorbent assay (ELISA) kits was used to detect free 25(OH)VitD and total 25(OH)VitD, and clinical information was collected. Spearman’s rho was used to evaluate the association between the variables. Results: The median (IQR) of free 25(OH)VitD was 4.71 (4.11-5.31) pg/mL and total 25(OH)VitD was 19.54 (16.52-22.83) ng/m. The correlation between them, however, was week (rho=0.311). Compared to total 25(OH)VitD, free 25(OH)VitD was slightly better correlated with basal follicle-stimulating hormone (FSH) (rho=0.041, P=0.036), basal estradiol (E2) (rho=0.089, P<0.001), anti-Müllerian hormone (AMH) (rho=-0.057, P=0.004), antral follicle count (AFC) (rho=-0.053, P=0.007), E2 (rho=-0.080, P<0.001), number of oocytes retrieval (rho=-0.079, P<0.001) and progesterone (P)/E2 on hCG trigger day (rho=0.081, P<0.001). Conclusions: Overall, there was only a rather weak correlation of free as well as total 25(OH)VitD with human endocrine and functional fertility parameters in women undergoing IVF/ICSI. Neither free nor total 25(OH)VitD seems to play a major role in human embryo implantation

Removal of Contaminants from Oracle Bones During Sample Pretreatment

Animal bones and tortoise shells were used for divination by the Chinese royal family during the Shang Dynasty (similar to w16th-11th century BC), and the divination results were recorded as inscriptions on oracle bones and shells, which are very valuable cultural remains and record many important events in the Shang Dynasty period. Thus, radiocarbon dating of oracle bones was used to build a precise chronology of the late Shang Dynasty. Due to their original burial conditions and the fact that in subsequent decades the pieces were traded or archived in museums, oracle bones are expected to be contaminated with exogenous materials from the environment and the conservation process. During dating, we found that some samples were contaminated by conservation chemical reagents. The contaminated samples were purified by removing exogenous chemicals with a series of organic solvents, in a method modified from Bruhn et al. (2001). Both whole bone and gelatin samples were processed with this purification method, resulting in satisfactory improvements in dating results.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000251221300005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Geochemistry &amp; GeophysicsSCI(E)CPCI-S(ISTP)

A Closer Look at the Belief Propagation Algorithm in Side-Channel-Assisted Chosen-Ciphertext Attacks

The implementation security of post-quantum cryptography (PQC) algorithms has emerged as a critical concern with the PQC standardization process reaching its end. In a side-channel-assisted chosen-ciphertext attack, the attacker builds linear inequalities on secret key components and uses the belief propagation (BP) algorithm to solve. The number of inequalities leverages the query complexity of the attack, so the fewer the better. In this paper, we use the PQC standard algorithm Kyber512 as a study case to construct bilateral inequalities on key variables with substantially narrower intervals using a side-channel-assisted oracle. The number of such inequalities required to recover the key with probability 1 utilizing the BP algorithm is reduced relative to previous unilateral inequalities. Furthermore, we introduce strategies aimed at further refining the interval of inequalities. Diving into the BP algorithm, we discover a measure metric named JSD-metric that can gauge the tightness of an inequality. We then develop a heuristic strategy and a machine learning-based strategy to utilize the JSD-metrics to contract boundaries of inequalities even with fewer inequalities given, thus improving the information carried by the system of linear inequalities. This contraction strategy is at the algorithmic level and has the potential to be employed in all attacks endeavoring to establish a system of inequalities concerning key variables

Effect of transanal drainage tube on prevention of anastomotic leakage after anterior rectal cancer surgery taking indwelling time into consideration: a systematic review and meta-analysis

BackgroundPlacement of an indwelling transanal drainage tube (TDT) to prevent anastomotic leakage (AL) after anterior rectal cancer surgery has become a routine choice for surgeons in the recent years. However, the specific indwelling time of the TDT has not been explored. We performed this meta-analysis and considered the indwelling time a critical factor in re-analyzing the effectiveness of TDT placement in prevention of AL after anterior rectal cancer surgery.MethodsRandomized controlled trials (RCTs) and cohort studies which evaluated the effectiveness of TDT in prevention of AL after rectal cancer surgery and considered the indwelling time of TDT were identified using a predesigned search strategy in databases up to November 2022. This meta-analysis was performed to estimate the pooled AL rates (Overall and different AL grades) and reoperation rates at different TDT indwelling times and stoma statuses.ResultsThree RCTs and 15 cohort studies including 2381 cases with TDT and 2494 cases without TDT were considered eligible for inclusion. Our meta-analysis showed that the indwelling time of TDT for ≥5-days was associated with a significant reduction (TDT vs. Non-TDT) in overall AL (OR=0.46,95% CI 0.34-0.60, p&lt;0.01), grade A+B AL (OR=0.64, 95% CI 0.42-0.97, p=0.03), grade C AL (OR=0.35, 95% CI 0.24-0.53, p&lt;0.01), overall reoperation rate (OR=0.36, 95%CI 0.24-0.53, p&lt;0.01) and that in patients without a prophylactic diverting stoma (DS) (OR=0.24, 95%CI 0.14-0.41, p&lt;0.01). There were no statistically significant differences in any of the abovementioned indicators (p&gt;0.05) when the indwelling time of TDT was less than 5 days.ConclusionExtending the postoperative indwelling time of TDT to 5 days may reduce the overall AL and the need for reoperation in patients without a prophylactic DS.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023407451, identifier CRD42023407451

Clinical characteristics and prognosis of 196 Chinese patients with colon cancer

AimsTo analyze the clinical characteristics and prognostic factors of Chinese patients with colon cancer.MethodsA retrospective analysis of the records of patients with colon cancer underwent surgery between 2014 and 2017 was performed. Univariate analysis in combination with Cox proportional hazard regression model was used to analyze the survival data, so as to reveal the prognostic factors of colon cancer. Data record was based on a standard data form. SPSS version 26.0 was used for data analysis (SPSS, Chicago, IL, United States).ResultsThe 3-year survival rate and the 5-year survival rate was 79.3% and 68.2%, respectively. Univariate analysis showed that radical surgery, laparoscopic surgery, ascites, swollen lymph nodes at the root of the mesentery, liver metastases, nerve invasion, vascular invasion, tumor node metastasis (TNM) staging, positive level of carbohydrate antigen (CA) 19-9, CA125, CA72-4 and combined detection were positive factors in the prognosis of colon cancer (P &lt; 0.05). Multivariate analysis showed that radical surgery and TNM staging were independent factors affecting the prognosis of patients with colon cancer (P &lt; 0.05).ConclusionRadical surgery and TNM staging have a significant impact on the prognosis of patients with colon cancer