Characterization of dissolved organic matter in water using Fourier Transform Infrared spectroscopy and X-ray photoelectron spectroscopy : implication for chemical composition and effects of water sources

Dissolved organic matter (DOM) from several freshwater sources (Hinkson Creek upstream and downstream of the City of Columbia, Missouri River, landfill leachate, and wastewater treatment plant (WWTP)) was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The goal was to identify major chemical compound classes, such as carboxylic acid, amide, ester, and aliphatic and aromatic characteristics in water samples from different sources. Results showed that samples from the city landfills contained the highest concentration of aromatic and protein-like compounds, while samples from WWTP contained more acids and hydrophilic fraction. It appeared that for freshwaters, the DOM inputs from the surroundings had a significant effect on the DOM chemical composition. The study demonstrated that coupling FTIR with XPS analyses could provide insights into the physicochemical and biogeochemical characteristics of DOM in different aquatic systems, as well as the characteristics of the environments from which the DOMs were derived

Security-Performance Tradeoff in DAG-based Proof-of-Work Blockchain Protocols

Proof-of-work (PoW) blockchain protocols based on directed acyclic graphs (DAGs) have demonstrated superior transaction confirmation performance compared to their chain-based predecessors. However, it is uncertain whether their security deteriorates in high-throughput settings similar to their predecessors, because their acceptance of simultaneous blocks and complex block dependencies presents challenges for rigorous security analysis. We address these challenges by analyzing DAG-based protocols via a congestible blockchain model (CBM), a general model that allows case-by-case upper bounds on the block propagation delay, rather than a uniform upper bound as in most previous analyses. CBM allows us to capture two key phenomena of high-throughput settings: (1) simultaneous blocks increase each other\u27s propagation delay, and (2) a block can be processed only after receiving all the blocks it refers to. We further devise a reasonable adversarial block propagation strategy in CBM, called the late-predecessor attack, which exploits block dependencies to delay the processing of honest blocks. We then evaluate the security and performance of Prism and OHIE, two DAG-based protocols that aim to break the security-performance tradeoff, in the presence of an attacker capable of launching the late predecessor attack. Our results show that these protocols suffer from reduced security and extended latency in high-throughput settings similar to their chain-based predecessors

Dual-Reference Source-Free Active Domain Adaptation for Nasopharyngeal Carcinoma Tumor Segmentation across Multiple Hospitals

Nasopharyngeal carcinoma (NPC) is a prevalent and clinically significant malignancy that predominantly impacts the head and neck area. Precise delineation of the Gross Tumor Volume (GTV) plays a pivotal role in ensuring effective radiotherapy for NPC. Despite recent methods that have achieved promising results on GTV segmentation, they are still limited by lacking carefully-annotated data and hard-to-access data from multiple hospitals in clinical practice. Although some unsupervised domain adaptation (UDA) has been proposed to alleviate this problem, unconditionally mapping the distribution distorts the underlying structural information, leading to inferior performance. To address this challenge, we devise a novel Sourece-Free Active Domain Adaptation (SFADA) framework to facilitate domain adaptation for the GTV segmentation task. Specifically, we design a dual reference strategy to select domain-invariant and domain-specific representative samples from a specific target domain for annotation and model fine-tuning without relying on source-domain data. Our approach not only ensures data privacy but also reduces the workload for oncologists as it just requires annotating a few representative samples from the target domain and does not need to access the source data. We collect a large-scale clinical dataset comprising 1057 NPC patients from five hospitals to validate our approach. Experimental results show that our method outperforms the UDA methods and achieves comparable results to the fully supervised upper bound, even with few annotations, highlighting the significant medical utility of our approach. In addition, there is no public dataset about multi-center NPC segmentation, we will release code and dataset for future research

NC-Max: Breaking the Security-Performance Tradeoff in Nakamoto Consensus

First implemented in Bitcoin, Nakamoto Consensus (NC) is the most influential consensus protocol in cryptocurrencies despite all the alternative protocols designed afterward. Nevertheless, NC is trapped by a security-performance tradeoff. While existing efforts mostly attempt to break this tradeoff via abandoning or adjusting NC\u27s backbone protocol, we alternatively forward the relevance of the network layer. We identify and experimentally prove that the crux resides with the prolonged block propagation latency caused by not-yet-propagated transactions. We thus present a two-step mechanism to confirm only fully-propagated transactions, and therefore remove the limits upon NC\u27s performance imposed by its security demands, realizing NC\u27s untapped potential. Implementing this two-step mechanism, we propose NC-Max, whose (1) security is analyzed, proving that it provides stronger resistance than NC against transaction withholding attacks, and (2) performance is evaluated, showing that it exhausts the full throughput supported by the network, and shortens the transaction confirmation latency by 3.0 to 6.6 times compared to NC without compromising security. NC-Max is implemented in Nervos CKB, a public permissionless blockchain

Integration and learning: a case study of the international higher physical education talent-cultivation model

IntroductionThis study delves into the multifaceted components of talent-training models within China’s physical education domain through Sino-foreign cooperative initiatives. Employing a mixed-methods approach, it systematically evaluates the innovative systems developed by pilot units and outlines their experiential insights.MethodsUsing a mixed-methods approach, this research extensively evaluates the situation of pilot units by collecting and analyzing data from closed-ended and open-ended questionnaires as well as interview responses. The study categorizes and analyzes the data to comprehensively understand cooperative talent-training models.ResultsThe findings are classified into three main themes: Learning, Integration, and Binary Evaluation and Practice Reform. Under the Learning theme, the study observed a selective integration of foreign educational paradigms into the local context, respecting the distinctiveness of Chinese education and aligning with national policies promoting unique educational systems. Additionally, the Integration theme underscores the necessity of meticulously assimilating introduced educational resources into China’s educational fabric, highlighting the need for adaptability when integrating foreign educational elements. Furthermore, the Binary Evaluation and Practice Reform theme reveal the establishment of a dualistic evaluation and reform system tailored to cooperative education specifics, outlining challenges associated with ideological and cultural disparities when integrating certain foreign education aspects into the Chinese context.DiscussionThis research provides insightful exploration into the complexities of collaborative talent-training models in Physical Education. It not only elucidates the assimilation of foreign paradigms but also highlights nuanced challenges and prospects for developing tailored educational systems within specific regional and national contexts

Effects of Self-Esteem on the Association between Negative Life Events and Suicidal Ideation in Adolescents

Negative life events (NLEs) increase the risk of suicidal ideation (SI) in adolescents. However, it is not known whether the association between NLEs and SI can be moderated by self-esteem and varies with gender. The aim of the current paper was to examine gender differences in the association of SI with NLEs in adolescents, and assess the effects of self-esteem on the association and their gender variations. We conducted a school-based health survey in 15 schools in China between November 2013 and January 2014. A total of 9704 participants aged 11–19 years had sociodemographic data reported and self-esteem (Rosenberg self-esteem scale), NLEs, and SI measured. Multivariate-adjusted logistic regression was used to calculate the odds ratio (OR) of having SI in relation to NLEs. Increased risk of SI was significantly associated with NLEs (adjusted OR 2.19, 95%CI 1.94–2.47), showing no gender differences (in females 2.38, 2.02–2.80, in males 1.96, 1.64–2.36, respectively). The association was stronger in adolescents with high esteem (2.93, 2.34–3.68) than those with low esteem (2.00, 1.65–2.42) (ORs ratio 1.47, p = 0.012). The matched figures in females were 3.66 (2.69–4.99) and 2.08 (1.61–2.70) (1.76, p = 0.006), while in males these figures were 2.27(1.62–3.19) and 1.89 (1.41–2.53) (1.20, p = 0.422), respectively. Self-esteem had moderate effects on the association between NLEs and SI in adolescents, mainly in females. NLEs, self-esteem, and gender need to be incorporated into future intervention programs to prevent SI in adolescents

Patterns of adverse childhood experiences and suicidal behaviors in adolescents: A four-province study in China

This is an accepted manuscript of a paper published by Elsevier on 23/02/2021, available online at: https://doi.org/10.1016/j.jad.2021.02.045 The accepted manuscript of the publication may differ from the final published version.Background:: Adverse childhood experiences (ACEs) are associated with increased suicidal behaviors in adolescents and most research has been restricted to certain types of or cumulative exposure to ACEs. Few studies have examined the association between patterns of ACEs and suicidal behaviors. Objective:: To identify the contributions of type and pattern of exposure to ACEs to suicidal behaviors and their gender differences among middle school students in China. Methods:: A school-based health survey was conducted in four provinces in China between 2017 and 2018. 14 500 students aged 10–20 years completed standard questionnaires, to record details of ACEs, suicide ideation, suicide plan, and suicide attempt. Results:: Latent class analysis indicated four distinct patterns of ACEs exposure: high ACEs (6.3%), high abuse and neglect (21.4%), high neglect (45.5%), and low ACEs (26.8%). Logistic analyses showed that, compared with low ACEs, the high ACEs were more likely to report suicidal behaviors. No gender differences were found in the independent effects of ACEs type or pattern on suicidal behaviors, except for the emotional neglect associated with suicidal behaviors in girls than boys. Limitations:: The study was cross-sectional and used self-reported questionnaires. Thus, it is difficult to establish a causal relationship between patterns of ACEs and suicidal behaviors. Conclusion:: Our findings addressed the need for a comprehensive consideration of ACEs in preventive healthcare work to identify children exposed to the most problematic ACE patterns. The study provided the evidence of targeted intervention to preempt the emergence of suicide behavior in at-risk students in adolescents.Funding for the project was provided by National Natural Science Foundation of China (82073576 & 81773453).Published versio

Potential benefits of vitamin D for sepsis prophylaxis in critical ill patients

BackgroundVitamin D deficiency is common in critically ill patients with suspected infection and is strongly associated with the predisposition of sepsis and a poor prognosis. The effectiveness of vitamin D supplementation for preventing sepsis remains unclear. This retrospective cohort study investigated the effect of vitamin D supplementation on sepsis prophylaxis in critically ill patients with suspected infection.MethodsThis retrospective cohort study included 19,816 adult patients with suspected infection in intensive care units (ICU) from 2008 to 2019 at the Beth Israel Deaconess Medical Center, Boston, USA. The included patients were divided into the vitamin D cohort or non-vitamin D cohort according to vitamin D administration status. The primary outcomes were the incidence of sepsis in ICU. The secondary outcomes included 28-day all-cause mortality, length of ICU and hospital stay and the requirements of vasopressors or mechanical ventilation. A propensity score matching cohort was used to test the differences in primary and secondary outcomes between groups.ResultsThe results showed that vitamin D supplementation demonstrated a lower risk of sepsis (odd ratio 0.46; 95% CI 0.35–0.60; P < 0.001) and a lower risk of new mechanical ventilation requirement (odd ratio 0.70; 95% CI 0.53-0.92; P = 0.01), but no significant difference in the risk of 28-day mortality was observed (hazard ratio 1.02; 95% CI 0.77–1.35; P = 0.89). In the sensitive analysis, among the patients who suspected infection within 24 h before or after ICU admission, a lower risk of sepsis and a lower percentage of new mechanical ventilation also were detected in the vitamin D cohort.ConclusionVitamin D supplementation may have a positively prophylactic effect on sepsis in critically ill patients with suspected infection