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An analysis of electricity consumption patterns in the water and wastewater sectors in South East England, UK
No full textThe water and wastewater sectors of England and Wales (E&W) are energy-intensive. Although E&W's water sector is of international interest, in particular due to the early experience with privatisation, for the time being, few published data on energy usage exist. We analysed telemetry energy-use data from ThamesWater Utilities Ltd. (TWUL), the largest water and wastewater company in the UK, which serves one of the largest mega-cities in the world, London. In our analysis, we: (1) break down energy use into their components; (2) present a statistical approach to handling seasonal and random cycles in data; and (3) derive energy-intensity (kWh m-3) metrics and compare them with other regions in the world. We show that electricity use in the sector grew by around 10.8 ± 0.4% year-1 as the utility coped with growing demands and stormwater flooding. The energy-intensity of water services in each of the utility's service zone was measured in the range 0.46-0.92 kWh m-3. Plans to improve the efficiency of the system could yield benefits in lower energy-intensity, but the overall energy saving would be temporary as external pressures from population and climate change are driving up water and energy use
Bonding similarities and differences between Y–Sb–Te and Sc–Sb–Te phase-change memory materials
No full textThe scandium (Sc) – alloyed Sb2Te3 phase-change alloy has recently been found to enable ultrafast crystal nucleation due to the formation of Sc-stabilized octahedral motifs in the amorphous phase, rendering cache-type phase-change memory feasible. When yttrium (Y) is added, however, non-octahedral bonding patterns form in the amorphous Sb2Te3-based network even though Y has a valence electron configuration similar to that of Sc and also forms perfect octahedral bonding environments with tellurium in the YTe crystal. Here we elucidate the origin of this difference between Sc and Y, by carrying out thorough ab initio simulations and orbital-based bonding analyses on amorphous Y–Sb–Te and Sc–Sb–Te compounds. We also demonstrate how the smooth overlap of atomic positions (SOAP) similarity kernel can be used to quantify the structural similarity of local motifs in the amorphous phase with respect to various crystalline yttrium and scandium tellurides, both in the nearest-neighbor shell and beyond. We find that the bonding contrast of Y- and Sc-centered structural motifs in amorphous Sb2Te3 stems from their parent crystals at high Te concentrations. The larger atomic radius of Y and the weaker charge transfer when bonded with Te is found to allow more Te neighbors and cause a more open bonding environment, leading to higher coordination numbers and non-octahedral environments. We discuss the implications of the different local environments for practical applications in memory devices
Paying SPECIAL consideration to the digital sharing of information during the COVID-19 pandemic and beyond
No full textCost-effective composite methods for large-scale solid-state calculations
No full textFollowing the development in recent years of progressively accurate approximations to the exchange-correlation functional, the use of density functional theory (DFT) methods to examine increasingly large and complex systems has grown, in particular for solids and other condensed mat- ter systems. However the cost of these calculations is high, often requiring the use of specialist HPC facilities. As such, for the purpose of large scale high-throughput screening of material properties, a hierarchy of simplified DFT methods has been proposed that allows the comparatively rapid calcu- lation of the electronic structure of large systems, and we have recently extended this scheme to the solid state (sol-3c) [J. Phys. Chem. 151, 121101 (2019)]. Here, we analyze the applicability and scaling of the new sol-3c DFT methods to molecules and crystals composed of light-elements, such as small proteins and model DNA-helices. Furthermore, the calculation of the electronic electronic structure of large to very large porous systems, such as metal-organic frameworks and inorganic nanoparticles, is discussed. The new composite methods have been implemented in the CRYSTAL17 code, which efficiently implements hybrid functionals and enables routine application of the new methods to large scale calculations of such materials with excellent performance even on small-scale computing resources
Seeing tourism transformations in Europe through algorithmic, techno-political and city-regional lenses
No full textIn light of the recent ‘tourism-phobia’, there is a need to better understand how tourism could be transformed through new business and social models. Attempts have been made, for example, to identify which experimental tourism models would align with the United Nations (UN) Sustainable Development Goals (SDGs). Nonetheless, research remains scant and the policy paradigm slightly out of date. With the pervasive proliferation of tourism services provided by big tech multinationals such as AirBnB and Uber and the rapid algorithmic disruption of the so-called “sharing economy” paradigm, several European cities and regions are seeking to mitigate the negative side-effects caused by “platform capitalism” in their neighborhoods and local communities. These side-effects include gentrification, privatization of public space, inherent conflicts between visitors/tourists and residents/locals, environmental damage, and precarious working conditions, among others. Thus, this paper explores why tourism in Europe requires new business and social models to neutralise this algorithmic disruption and modify the extractivist neoliberal logic in tourism to develop new, transformative, techno-political, bottom-up, and networked strategies stemming from the city-regional realm. Against the backdrop of the General Data Protection Regulation (GDPR) in the EU that has recently taken effect on 25 May 2018, this paper argues that a new, transformative, tourism paradigm could emerge from the European political left. The push of the city-regional resurgence beyond established nation-states could enable grassroots and institutional tourism initiatives to take the lead and coordinate a political response to achieve further sustainable, equitable, and, ultimately, democratic technological sovereignty in diverse localities through Europe. In conclusion, this paper posits city-regional, bottom-up, and networked dynamics characterised by the GDPR as an opportunity to establish a new techno-political paradigm in tourism by overcoming data and algorithmic extractivist practices. To cite this publication: Calzada, I. (2020), Seeing Tourism Transformations in Europe through Algorithmic, Techno-Political and City-Regional Lenses, In Transforming Tourism: Regional Perspectives on a Global Phenomenon. Edited by the Coppieters and Ezkerraberri Foundations. 2020/01. Chapter 6. pp 74-89. Brussels: Centre Maurits Coppieters CMC. ISBN: 978-90-826321-0-1. doi:10.13140/RG.2.2.33522.45769/1
A borderline case of Calderón–Zygmund estimates for nonuniformly elliptic problems
No full textIn a borderline case which was not covered before, nonlinear Calderón-Zygmund estimates are shown to be valid for a class of nonuniformly elliptic problems driven by double phase energies
Clinical effectiveness and safety of aspirin for venous thromboembolism prophylaxis after total hip and knee replacement: a systematic review and meta-analysis of randomized clinical trials
No full textImportance Patients undergoing total hip replacement (THR) and total knee replacement (TKR) receive venous thromboembolism (VTE) pharmacoprophylaxis. It is unclear which anticoagulant is preferable. Observational data suggest aspirin provides effective VTE prophylaxis.
Objective To assess the effectiveness and safety of aspirin for VTE prophylaxis after THR and TKR.
Data Sources A systematic review and meta-analysis was performed of randomized clinical trials (RCTs), with no language restrictions, from inception to September 19, 2019, using MEDLINE, Embase, Web of Science, Cochrane Library, and bibliographic searches. The computer-based searches combined terms and combinations of keywords related to the population (eg, hip replacement, knee replacement, hip arthroplasty, and knee arthroplasty), drug intervention (eg, aspirin, heparin, clexane, dabigatran, rivaroxaban, and warfarin), and outcome (eg, venous thromboembolism, deep vein thrombosis, pulmonary embolism, and bleeding) in humans.
Study Selection This study included RCTs assessing the effectiveness and safety of aspirin for VTE prophylaxis compared with other anticoagulants in adults undergoing THR and TKR. The RCTs with a placebo control group were excluded. The searches and study selection were independently performed.
Data Extraction and Synthesis This study followed PRISMA recommendations and used the Cochrane Collaboration’s risk of bias tool. Data were screened and extracted independently by both reviewers. Study-specific relative risks (RRs) were aggregated using random-effects models. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
Main Outcomes and Measures The primary outcome was any postoperative VTE (asymptomatic or symptomatic). Secondary outcomes were adverse events associated with therapy, including bleeding.
Results Of 437 identified articles, 13 RCTs were included (6060 participants; 3466 [57.2%] women; mean age, 63.0 years). The RR of VTE after THR and TKR was 1.12 (95% CI, 0.78-1.62) for aspirin compared with other anticoagulants. Comparable findings were observed for deep vein thrombosis (DVT) (RR, 1.04; 95% CI, 0.72-1.51) and pulmonary embolism (PE) (RR, 1.01; 95% CI, 0.68-1.48). The risk of adverse events, including major bleeding, wound hematoma, and wound infection, was not statistically significantly different in patients receiving aspirin vs other anticoagulants. When analyzing THRs and TKRs separately, there was no statistically significant difference in the risk of VTE, DVT, and PE between aspirin and other anticoagulants. Aspirin had a VTE risk not statistically significantly different from low-molecular-weight heparin (RR, 0.76; 95% CI, 0.37-1.56) or rivaroxaban (RR, 1.52; 95% CI, 0.56-4.12). The quality of the evidence ranged from low to high.
Conclusions and Relevance In terms of clinical effectiveness and safety profile, aspirin did not differ statistically significantly from other anticoagulants used for VTE prophylaxis after THR and TKR. Future trials should focus on noninferiority analysis of aspirin compared with alternative anticoagulants and cost-effectiveness
Prevalence, prognosis, and treatment of atherosclerotic intracranial stenosis in Caucasians
No full textBackground
Intracranial atherosclerotic stenosis is a highly prevalent cause of stroke worldwide with important ethnic disparities. Widely considered to be a common cause of stroke in Asian and Afro-Caribbean populations, relatively less is known about the burden and significance of intracranial atherosclerotic stenosis in Caucasians.
Aims
We aim to highlight recent insights and advances into the prevalence, prognosis, and treatment of symptomatic and asymptomatic atherosclerotic intracranial atherosclerotic stenosis in Caucasian patients.
Summary of review
We identified 48 articles studying intracranial atherosclerotic stenosis in Caucasian patients with ischemic stroke or transient ischemic attack. Most studies were on hospital-based cohorts of consecutive patients and half were graded as “fair” quality. There was significant variation between studies in the definition of intracranial atherosclerotic stenosis and in the imaging modalities used to detect intracranial atherosclerotic stenosis. Overall, 12.1% of Caucasian patients were found to have any intracranial atherosclerotic stenosis, 6.4% symptomatic intracranial atherosclerotic stenosis and 11.1% asymptomatic intracranial atherosclerotic stenosis, with higher rates at older ages. In studies reporting prognosis, there were 61 and 10 same-territory ischemic strokes in 1000 person-years in patients with symptomatic and asymptomatic intracranial atherosclerotic stenosis, respectively. Percutaneous stenting and angioplasty have not proven superior to intensive medical management in patients with symptomatic intracranial atherosclerotic stenosis.
Conclusions
Intracranial atherosclerotic stenosis has previously been neglected as a cause of stroke in Caucasians but is highly prevalent at older ages and frequently discovered with the growing use of noninvasive angiography. Intensive medical therapy is the treatment of choice, but there is a need to develop novel treatments or therapeutic approaches to lower the risk of stroke in higher risk patients