4,246 research outputs found

    China Maritime Report No. 28: Bitterness Ends, Sweetness Begins: Organizational Changes to the PLAN Submarine Force Since 2015

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    ā€œAbove-the-neckā€ reforms in the Peopleā€™s Liberation Army (PLA) that began in 2015 directed the development of a new joint operational command system that resulted in commensurate changes to PLA Navy submarine force command and control. Additional changes to tactical submarine command and control were driven by the evolution and expansion of PLA Navy surface and airborne capabilities and the introduction of new longer-range submarine weapons. Follow-on ā€œbelow-theneckā€ reforms inspired significant organizational change across most of Chinaā€™s military services. However, the PLA Navy submarine force, for its part, did not reorganize its command structure but instead focused on significant improvements to the composition and quality of its force. Between 2017 and 2023, the PLA Navy submarine force engaged in a notable transformation, shuffling personnel and crews among twenty-six submarinesā€”eleven newly commissioned and fifteen since retiredā€”relocating in-service submarines to ensure an equitable distribution of newer, more capable submarines across the fleet. Observations of infrastructure improvements at PLA Navy submarine bases portend even more changes to submarine force structure in the coming years.https://digital-commons.usnwc.edu/cmsi-maritime-reports/1027/thumbnail.jp

    New methods for the synthesis of spirocyclic cephalosporin analogues

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    Spiro compounds provide attractive targets in drug discovery due to their inherent three-dimensional structures, which enhance protein interactions, aid solubility and facilitate molecular modelling. However, synthetic methodology for the spiro-functionalisation of important classes of penicillin and cephalosporin Ī²-lactam antibiotics is comparatively limited. We report a novel method for the generation of spiro-cephalosporin compounds through a Michael-type addition to the dihydrothiazine ring. Coupling of a range of catechols is achieved under mildly basic conditions (K2CO3, DMF), giving the stereoselective formation of spiro-cephalosporins (d.r. 14:1 to 8:1) in moderate to good yields (28āˆ’65%)

    Knockdown of Arabidopsis ROOT UVB SENSITIVE4 Disrupts Anther Dehiscence by Suppressing Secondary Thickening in the Endothecium

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    ROOT UV-B SENSITIVE4 (RUS4) encodes a protein with no known function that contains a conserved Domain of Unknown Function 647 (DUF647). The DUF647-containing proteins RUS1 and RUS2 have previously been associated with root UV-B-sensing pathway that plays a major role in Arabidopsis early seedling morphogenesis and development. Here, we show that RUS4 knockdown Arabidopsis plants, referred to as amiR-RUS4, were severely reduced in male fertility with indehiscent anthers. Light microscopy of anther sections revealed a significantly reduced secondary wall thickening in the endothecium of amiR-RUS4 anthers. We further show that transcript abundance of the NAC domain genes NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1) and NST2, which have been shown to regulate the secondary cell wall thickenings in the anther endothecium, were dramatically reduced in the amiR-RUS4 floral buds. Expression of the secondary cell wall-associated MYB transcription factor genes MYB103 and MYB85 were also strongly reduced in floral buds of the amiR-RUS4 plants. Overexpression of RUS4 led to increased secondary thickening in the endothecium. However, the rus4-2 mutant exhibited no obvious phenotype. Promoter-GUS analysis revealed that RUS4 promoter was highly active in the anthers, supporting its role in anther development. Taken together, these results suggest that RUS4, probably functions redundantly with other genes, may play an important role in the secondary thickening formation in the anther endothecium by indirectly affecting the expression of secondary cell wall biosynthetic genes

    Understanding the Complex Behaviours of Electric Vehicle Drivers with Agent-Based Models in Glasgow

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    With the new policy aimed at advancing the phase-out date for the sale of new petrol and diesel cars and vans to 2030, the electric vehicle (EV) market share is expected to rise significantly in the coming years. This necessitates a deeper understanding of the driving and charging behaviours of EV drivers to accurately estimate future charging demand distribution and benefit for future infrastructure development. Traditional data-based approaches are limited in illustrating the granular spatiotemporal dynamics of individuals. Recent studies that use conventional vehicle trajectory data also have the sampling bias problem, despite their analyses being conducted at a finer resolution. Moreover, studies that use simulation approaches are often either based on limited behaviour rules for EV drivers or implemented in an artificial grid environment, showing limitations in reflecting real-world situations. To address the challenges, this work introduces an agent-based model (ABM) with complex behaviour rules for EV drivers, taking into account the driversā€™ sensitivities to financial and time costs, as well as route deviation. By integrating the simulation model with the origin and destination information of drivers, this work can contribute to a better understanding of the behaviour patterns of EV drivers

    Analysis of electrophysiological activation of the uterus during human labor contractions

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    This cohort study uses electromyometrial imaging to examine the underlying electrophysiological origins of human labor at the myometrium level

    A review of allā€vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies

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    The allā€vanadium redox flow battery (VRFB) is emerging as a promising technology for largeā€scale energy storage systems due to its scalability and flexibility, high roundā€trip efficiency, long durability, and little environmental impact. As the degradation rate of the VRFB components is relatively low, less attention has been paid in terms of VRFB durability in comparison with studies on performance improvement and cost reduction. This paper reviews publications on performance degradation mechanisms and mitigation strategies for VRFBs in an attempt to achieve a systematic understanding of VRFB durability. Durability studies of individual VRFB components, including electrolyte, membrane, electrode, and bipolar plate, are introduced. Various degradation mechanisms at both cell and component levels are examined. Following these, applicable strategies for mitigating degradation of each component are compiled. In addition, this paper summarizes various diagnostic tools to evaluate component degradation, followed by accelerated stress tests and models for aging prediction that can help reduce the duration and cost associated with real lifetime tests. Finally, future research areas on the degradation and accelerated lifetime testing for VRFBs are proposed

    The impact of demographic and risk factor changes on coronary heart disease deaths in Beijing, 1999ā€“2010

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    BACKGROUND: Recent, dramatic increases in coronary heart disease (CHD) mortality in China can be mostly explained by adverse changes in major cardiovascular risk factors. Our study aimed to assess the potential impact of subsequent changes in risk factors and population ageing on CHD deaths in Beijing between 1999 and 2010. METHODS: The previously validated IMPACT model was used to estimate the CHD deaths expected in 2010, with treatment uptakes being held constant at levels measured in 1999, comparing three scenarios: a) taking into account the ageing of the population but assuming no further changes in major risk factor levels from 1999 or, b) if recent risk factor trends continued until 2010 or, c) if there was a 0.5% annual reduction in each risk factor. RESULTS: Population ageing alone would result in approximately 1990 additional deaths in 2010 compared with 1999, representing an increase of 27%. Continuation of current risk factor trends would result in approximately 3,015 extra deaths in 2010, [a 40% increase]; three quarters of this increase would be attributable to rises in total cholesterol levels. Thus, demographic changes and worsening risk factors would together result in a 67% increase in CHD deaths. Conversely, assumed 0.5% annual reductions in risk factors (a mean population level decline of 0.3 mmol/L for total cholesterol in both genders, and smoking prevalence declining by 3.0% for men and 4.1% for women, body mass index by 1.3 kg/m2 for men and 1.4 kg/m2 for women, diabetes prevalence by 0.4% in both genders, and diastolic blood pressure by 4.7 mmHg for men and 4.4 mmHg for women) would result in some 3,730 fewer deaths, representing a 23% decrease overall. These findings remained consistent in sensitivity analyses. CONCLUSION: CHD death rates are continuing to rise in Beijing. This reflects worsening risk factor levels, compounded by demographic trends. However, the adverse impact of population ageing on CHD burden could be completely offset by eminently feasible improvements in diet and smoking

    Cremations, Dental Amalgams, and You

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    Introduction: In Vermont, cremation has increasingly become an alternative to interment of an intact body. Many of the bodies being cremated contain dental amalgams, which are commonly used by dentists to repair dental erosion and caries (cavities). They are an economical option for caries repair, and remain popular. Roughly one third of all caries fillings done in 2002 in the U.S. utilized amalgam. Amalgam is a metal alloy containing as much as 50% mercury by volume, a metal that is a known toxicant. Dental amalgams, may constitute a source of low level, continual exposure for those with these dental devices in situ and may be released to the atmosphere upon cremation. The goal of this project was to investigate: 1. The status of the scientific opinion on potential health effects that may be associated with having dental amalgams. 2. To help refine State estimates of potential mercury emissions from Vermont crematoria.https://scholarworks.uvm.edu/comphp_gallery/1075/thumbnail.jp
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