Disassortative mixing in online social networks

The conventional wisdom is that social networks exhibit an assortative mixing pattern, whereas biological and technological networks show a disassortative mixing pattern. However, the recent research on the online social networks modifies the widespread belief, and many online social networks show a disassortative or neutral mixing feature. Especially, we found that an online social network, Wealink, underwent a transition from degree assortativity characteristic of real social networks to degree disassortativity characteristic of many online social networks, and the transition can be reasonably elucidated by a simple network model that we propose. The relations among network assortativity, clustering, and modularity are also discussed in the paper.Comment: 6 pages, 5 figures, 1 tabl

The Peahen’s Tale, or Dressing Our Parts at Work

However, there may ultimately be no logical way to reconcile decisions that prohibit employers from requiring women to wear revealing outfits and others that permit employers to require them to wear makeup,20 or decisions that prohibit penalizing a woman for being insufficiently feminine and others that permit penalizing a man for being insufficiently masculine.21 In addition, the increasing judicial acceptance of the sex stereotyping theory of sex discrimination under Title VII is in substantial tension with recent cases that insist that sex-differentiated dress and grooming requirements that merely 22 conform to existing social gender norms do not amount to impermissible sex discrimination. Because dress is so crucial a characteristic in sexually dimorphic species, and because it is so closely tied to sexual attractiveness, choice, and power dynamics, employers should be prohibited from requiring women to dress in gender normative ways that reflect those traits even if they believe that such dress codes do not amount to intentional sex stereotyping.223 Where, as here, so many threads come together to demonstrate that sex differences in dress are likely to affect the way that individuals are treated by others, employers should not be permitted to mandate differences that implicate notions of attractiveness or power

How people make friends in social networking sites - A microscopic perspective

We study the detailed growth of a social networking site with full temporal information by examining the creation process of each friendship relation that can collectively lead to the macroscopic properties of the network. We first study the reciprocal behavior of users, and find that link requests are quickly responded to and that the distribution of reciprocation intervals decays in an exponential form. The degrees of inviters/accepters are slightly negatively correlative with reciprocation time. In addition, the temporal feature of the online community shows that the distributions of intervals of user behaviors, such as sending or accepting link requests, follow a power law with a universal exponent, and peaks emerge for intervals of an integral day. We finally study the preferential selection and linking phenomena of the social networking site and find that, for the former, a linear preference holds for preferential sending and reception, and for the latter, a linear preference also holds for preferential acceptance, creation, and attachment. Based on the linearly preferential linking, we put forward an analyzable network model which can reproduce the degree distribution of the network. The research framework presented in the paper could provide a potential insight into how the micro-motives of users lead to the global structure of online social networks.Comment: 10 pages, 12 figures, 2 table

Individual popularity and activity in online social systems

We propose a stochastic model of web user behaviors in online social systems, and study the influence of attraction kernel on statistical property of user or item occurrence. Combining the different growth patterns of new entities and attraction patterns of old ones, different heavy-tailed distributions for popularity and activity which have been observed in real life, can be obtained. From a broader perspective, we explore the underlying principle governing the statistical feature of individual popularity and activity in online social systems and point out the potential simple mechanism underlying the complex dynamics of the systems.Comment: 7 pages, 7 figures, 1 table, accepted for publication in Physica

Challenges and Opportunities for Second-life Batteries: A Review of Key Technologies and Economy

Due to the increasing volume of Electric Vehicles in automotive markets and the limited lifetime of onboard lithium-ion batteries (LIBs), the large-scale retirement of LIBs is imminent. The battery packs retired from Electric Vehicles still own 70%-80% of the initial capacity, thus having the potential to be utilized in scenarios with lower energy and power requirements to maximize the value of LIBs. However, spent batteries are commonly less reliable than fresh batteries due to their degraded performance, thereby necessitating a comprehensive assessment from safety and economic perspectives before further utilization. To this end, this paper reviews the key technological and economic aspects of second-life batteries (SLBs). Firstly, we introduce various degradation models for first-life batteries and identify an opportunity to combine physics-based theories with data-driven methods to establish explainable models with physical laws that can be generalized. However, degradation models specifically tailored to SLBs are currently absent. Therefore, we analyze the applicability of existing battery degradation models developed for first-life batteries in SLB applications. Secondly, we investigate fast screening and regrouping techniques and discuss the regrouping standards for the first time to guide the classification procedure and enhance the performance and safety of SLBs. Thirdly, we scrutinize the economic analysis of SLBs and summarize the potentially profitable applications. Finally, we comprehensively examine and compare power electronics technologies that can substantially improve the performance of SLBs, including high-efficiency energy transformation technologies, active equalization technologies, and technologies to improve reliability and safety

Concentration-dependent effects of narciclasine on cell cycle progression in Arabidopsis root tips

<p>Abstract</p> <p>Background</p> <p>Narciclasine (NCS) is an Amaryllidaceae alkaloid isolated from <it>Narcissus tazetta </it>bulbs. NCS has inhibitory effects on a broad range of biological activities and thus has various potential practical applications. Here we examine how NCS represses plant root growth.</p> <p>Results</p> <p>Results showed that the inhibition of NCS on cell division in <it>Arabidopsis </it>root tips and its effects on cell differentiation are concentration-dependent; at low concentrations (0.5 and 1.0 μM) NCS preferentially targets mitotic cell cycle specific/cyclin complexes, whereas at high concentration (5.0 μM) the NCS-stimulated accumulation of Kip-related proteins (KRP1 and RP2) affects the CDK complexes with a role at both G1/S and G2/M phases.</p> <p>Conclusions</p> <p>Our findings suggest that NCS modulates the coordination between cell division and differentiation in <it>Arabidopsis </it>root tips and hence affects the postembryonic development of <it>Arabidopsis </it>seedlings.</p

New risk score for predicting progression of membranous nephropathy

Abstract Background Patients with Idiopathic membranous nephropathy (IMN) have various outcomes. The aim of this study is to construct a tool for clinicians to precisely predict outcome of IMN. Methods IMN patients diagnosed by renal biopsy from Shanghai Ruijin Hospital from 2009.01 to 2013.12 were enrolled in this study. Primary outcome was defined as a combination of renal function progression [defined as a reduction of estimated glomerular filtration rate (eGFR) equal to or over 30% comparing to baseline], ESRD or death. Risk models were established by Cox proportional hazard regression analysis and validated by bootstrap resampling analysis. ROC curve was applied to test the performance of risk score. Results Totally 439 patients were recruited in this study. The median follow-up time was 38.73 ± 19.35 months. The enrolled patients were 56 (15–83) years old with a male predominance (sex ratio: male vs female, 1:0.91). The median baseline serum albumin, eGFR-EPI and proteinuria were 23(8–43) g/l, 100.31(12.81–155.98) ml/min/1.73 m2 and 3.98(1.50–22.98) g/24 h, respectively. In total, there were 36 primary outcomes occurred. By Cox regression analysis, the best risk model included age [HR: 1.04(1.003–1.08), 95% CI from bootstrapping: 1.01–1.08), eGFR [HR: 0.97 (0.96–0.99), 95% CI from bootstrapping: 0.96–0.99) and proteinuria [HR: 1.09 (1.01–1.18), 95% CI from bootstrapping: 1.02–1.16). One unit increasing of the risk score based on the best model was associated with 2.57 (1.97–3.36) fold increased risk of combined outcome. The discrimination of this risk score was excellent in predicting combined outcome [C statistics: 0.83, 95% CI 0.76–0.90]. Conclusions Our study indicated that older IMN patients with lower eGFR and heavier proteinuria at the time of renal biopsy were at a higher risk for adverse outcomes. A risk score based on these three variables provides clinicians with an effective tool for risk stratification.https://deepblue.lib.umich.edu/bitstream/2027.42/147736/1/12967_2019_Article_1792.pd

The effect of health insurance reform on the number of cataract surgeries in Chongqing, China

<p>Abstract</p> <p>Background</p> <p>Cataracts are the leading cause of blindness in China, and poverty is a major barrier to having cataract surgery. In 2003, the Chinese government began a series of new national health insurance reforms, including the New Cooperative Medical Scheme (NCMS) and the Urban Resident Basic Health Insurance scheme (URBMI). These two programs, combined with the previously existing Urban Employee Basic Health Insurance (UEBMI) program, aimed to make it easier for individuals to receive medical treatment. This study reports cataract surgery numbers in rural and urban populations and the proportion of these who had health insurance in Chongqing, China from 2003 to 2008.</p> <p>Methods</p> <p>The medical records of a consecutive case series, including 14,700 eyes of 13,262 patients who underwent age-related cataract surgery in eight hospitals in Chongqing from January 1, 2003, to December 31, 2008, were analysed retrospectively via multi-stage cluster sampling.</p> <p>Results</p> <p>In the past six years, the total number of cataract surgeries had increased each year as had the number of patients with insurance. Both the number of surgeries and the number of insured patients were much higher in the urban group than in the rural group. The rate of increase in the rural group however was much higher than in the urban group, especially in 2007 and 2008. The odds ratios of having health insurance for urban vs. rural individuals were relatively stable from 2003 to 2006, but it decreased in 2007 and was significantly lower in 2008.</p> <p>Conclusions</p> <p>Health insurance appears to be an important factor associated with increased cataract surgery in Chongqing, China. With the implementation of health insurance, the number of Chongqing's cataract surgeries was increased year by year.</p

Clinical Significance of Angiographically Detectable Neovascularity in Patients with Cardiac Myxoma

Background: Myxomas are the most common primary cardiac tumors. Angiographically detectable neovascularity (ADN) of myxoma is increasingly being reported as a result of the use of coronary angiography (CAG) to detect coronary artery disease. However, the clinical significance of these findings is not fully understood. Methods: We enrolled 59 patients with cardiac myxoma who also underwent CAG between January 2013 and October 2018. Patients were followed up for a mean of 28.9 months (range 1–69 months). The clinical features, echocardiography measurements, pathological examination findings, CAG results, and outcomes during follow-up were compared between patients with ADN and patients without ADN. Results: ADN was found in 25 patients (42.4%). The arteries feeding the ADN included the right coronary artery ( n=15), the left circumflex coronary artery ( n=7), and both arteries ( n=3). The patients with ADN had a higher proportion of eosinophils (3.2% vs. 2.2%, P=0.03) and higher low-density lipoprotein cholesterol level (2.7 mmol/L vs. 2.2 mmol/L, P=0.02). Myxoma pedicles were more likely to be located in the interatrial septum in patients with ADN (96% vs. 73.5%, P=0.02). No significant correlation was observed between the groups in clinical manifestations, atrial arrhythmia, myxoma size, cardiac chamber size, left ventricular ejection fraction, and the prevalence of complication with coronary artery disease [16% in the ADN group ( n=4) vs. 20.6% in the non-ADN group ( n=7), P=0.66]. However, patients with ADN tended to have a lower incidence of major adverse cardiac and cerebrovascular events on long-term follow-up (0% vs. 14.7%, P=0.07). Conclusion: CAG-detected ADN in patients with cardiac myxoma is associated with a borderline lower rate of major adverse cardiac and cerebrovascular events. </p