8,353 research outputs found
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Asymptotic behaviour of the posterior distribution in approximate Bayesian computation
Approximate Bayesian computation (ABC) is a popular technique for approximating likelihoods and is often used in parameter estimation when the likelihood functions are analytically intractable. In the context of Hidden Markov Models (HMMs), we analyse the asymptotic behaviour of the posterior distribution in ABC based Bayesian parameter estimation. In particular we show that Bernstein-von Mises type results still hold but that the resulting posterior is biased in the sense that it concentrates around a point in parameter space that differs from the true parameter value. Furthermore we obtain precise rates for the size of this bias with respect to a natural accuracy parameter of the ABC method. Finally we discuss, via a numerical example, the implications of our results for the practical implementation of ABC
Oxidation products of DNA, lipid and protein among the individuals progressing towards metabolic syndrome
Oxidative stress (OS) is an early event and at the same time also a consequence in the pathology of MetS. We investigated if oxidation markers of DNA, lipid and protein increased with an increase in the risk parameters of MetS. Participants (male:70, female:90 ≥ 20 yrs) were categorized based on the number of risk factors they had as 3 Risk, 2 Risk, 1 Risk and 0 Risk for MetS and were evaluated for various oxidation markers. Protein carbonyl and advanced oxidation protein product (protein oxidation marker) differed significantly between the four study group while malondialdehyde and hydroxynonenal (lipid peroxidation marker) did not. “8-OH dG” (DNA oxidation marker) differed significantly (P< 0.05) while total antioxidant capacity did not demonstrate significant difference in its values across the group (P> 0.05). Pairwise comparison for statistically significant markers(Protein oxidation markers and 8-OH dG), demonstrated that only 8-OH dG differed significantly between 0 Risk- 3 Risk (P< 0.012) but not between 0 Risk -2 Risk and 0 Risk-1 Risk. Oxidative stress markers of DNA, lipid and protein do not increase with an increase in the risk parameters of MetS. However, it is indeed high in MetS with 3 and more risk parameters. Presence of 2 or 1 Risk also increases OS compared to 0 Risk. There is oxidative stress damage in MetS to lipid and protein but DNA damage was of significant consequence
The challenge in diagnosing and managing heterotopic interstitial pregnancy in natural conception / Noor Azura Noor Mohamad … [et al.]
Heterotopic interstitial pregnancy in natural conception is very rare. Definitive diagnosis is made by systematic pelvic ultrasound. Simultaneous viable conception observed in both intraand extra-uterine is pathognomonic of heterotopic interstitial pregnancy. We report a 34-yearold woman primigravida at 10 weeks’ amenorrhoea who underwent evacuation of retained product of conception for missed miscarriage. Intraoperatively, minimal product of conception was retrieved. Bedside pelvic ultrasound showed cystic mass at right superolateral part of uterine fundus suspicious of interstitial pregnancy. Cornual resection was performed via laparotomy. Histopathological examination showed presence of product of conception and interstitial pregnancy. Serum β-human chorionic gonadotropin dropped from 10,027 IU/l on day one post-ERPC to 210 IU/l at day three post-cornual resection. This case report highlighted the challenge in diagnosing heterotopic interstitial pregnancy conceived naturally. Timely diagnosis may avert dire consequences of massive haemorrhage from ruptured uterine cornua
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Vehicle technologies heavy vehicle program : FY 2008 benefits analysis, methodology and results --- final report.
This report describes the approach to estimating the benefits and analysis results for the Heavy Vehicle Technologies activities of the Vehicle Technologies (VT) Program of EERE. The scope of the effort includes: (1) Characterizing baseline and advanced technology vehicles for Class 3-6 and Class 7 and 8 trucks, (2) Identifying technology goals associated with the DOE EERE programs, (3) Estimating the market potential of technologies that improve fuel efficiency and/or use alternative fuels, and (4) Determining the petroleum and greenhouse gas emissions reductions associated with the advanced technologies. In FY 08 the Heavy Vehicles program continued its involvement with various sources of energy loss as compared to focusing more narrowly on engine efficiency and alternative fuels. These changes are the result of a planning effort that first occurred during FY 04 and was updated in the past year. (Ref. 1) This narrative describes characteristics of the heavy truck market as they relate to the analysis, a description of the analysis methodology (including a discussion of the models used to estimate market potential and benefits), and a presentation of the benefits estimated as a result of the adoption of the advanced technologies. The market penetrations are used as part of the EERE-wide integrated analysis to provide final benefit estimates reported in the FY08 Budget Request. The energy savings models are utilized by the VT program for internal project management purposes
Pulmonary intravascular macrophages: Prime suspects as cellular mediators of porcine CARPA
Pigs provide a highly sensitive and quantitative in vivo model for complement (C) activation-related pseudoallergy (CARPA), a hypersensitivity reaction caused by some state-of-art nanomedicines. In an effort to understand the mechanism of the pigs' unique sensitivity for CARPA, this review focuses on pulmonary intravascular macrophages (PIMs), which are abundantly present in the lung of pigs. These cells represent a macrophage subpopulation whose unique qualities explain the characteristic symptoms of CARPA in this species, most importantly the rapidly (within minutes) developing pulmonary vasoconstriction, leading to elevation of pulmonary arterial pressure. The unique qualities of PIM cells include the following; 1) they are strongly adhered to the capillary walls via desmosome-like intercellular adhesion plaques, which secure stable and lasting direct exposition of the bulk of these cells to the blood stream; 2) their ruffled surface engaged in intense phagocytic activity ensures efficient binding and phagocytosis of nanoparticles; 3) PIM cells express anaphylatoxin receptors, this way C activation can trigger these cells, 4) they also express pattern recognition molecules on their surface, whose engagement with certain coated nanoparticles may also activate these cells or act in synergy with anaphylatoxins and, finally 5) their high metabolic activity and capability for immediate secretion of vasoactive mediators upon stimulation explain the circulatory blockage and other robust physiological effects that their stimulation may cause. These qualities taken together with reports on liposome uptake by PIM cells during CARPA and the possible presence of these cells in human lung suggests that PIM cells may be a potential therapeutic target against CARPA. © 2015 by De Gruyter
Guideline concordance for timely chest imaging after new presentations of dyspnoea or haemoptysis in primary care: a retrospective cohort study
BACKGROUND: Guidelines recommend urgent chest X-ray for newly presenting dyspnoea or haemoptysis but there is little evidence about their implementation. METHODS: We analysed linked primary care and hospital imaging data for patients aged 30+ years newly presenting with dyspnoea or haemoptysis in primary care during April 2012 to March 2017. We examined guideline-concordant management, defined as General Practitioner-ordered chest X-ray/CT carried out within 2 weeks of symptomatic presentation, and variation by sociodemographic characteristic and relevant medical history using logistic regression. Additionally, among patients diagnosed with cancer we described time to diagnosis, diagnostic route and stage at diagnosis by guideline-concordant status. RESULTS: In total, 22 560/162 161 (13.9%) patients with dyspnoea and 4022/8120 (49.5%) patients with haemoptysis received guideline-concordant imaging within the recommended 2-week period. Patients with recent chest imaging pre-presentation were much less likely to receive imaging (adjusted OR 0.16, 95% CI 0.14-0.18 for dyspnoea, and adjusted OR 0.09, 95% CI 0.06-0.11 for haemoptysis). History of chronic obstructive pulmonary disease/asthma was also associated with lower odds of guideline concordance (dyspnoea: OR 0.234, 95% CI 0.225-0.242 and haemoptysis: 0.88, 0.79-0.97). Guideline-concordant imaging was lower among dyspnoea presenters with prior heart failure; current or ex-smokers; and those in more socioeconomically disadvantaged groups.The likelihood of lung cancer diagnosis within 12 months was greater among the guideline-concordant imaging group (dyspnoea: 1.1% vs 0.6%; haemoptysis: 3.5% vs 2.7%). CONCLUSION: The likelihood of receiving urgent imaging concords with the risk of subsequent cancer diagnosis. Nevertheless, large proportions of dyspnoea and haemoptysis presenters do not receive prompt chest imaging despite being eligible, indicating opportunities for earlier lung cancer diagnosis
Superior visible photoelectric response with Au/Cu2NiSnS4 core-shell nanocrystals
The incorporation of plasmonic metal nanostructures into semiconducting
chalcogenides, in the form of core-shell structures, represents a promising
approach to boosting the performance of photodetectors. In this study, we
combined Au nanoparticles with newly developed copper-based chalcogenides
Cu2NiSnS4 (Au/CNTS), to achieve an ultrahigh optoelectronic response in the
visible regime. The high-quality Au/CNTS core-shell structure was synthesized
by developing a unique colloidal hot-injection method, which allowed excellent
control over sizes, shapes, and elemental compositions. The fabricated Au/CNTS
hybrid core-shell structure exhibited enhanced optical absorption, carrier
extraction efficiency, and improved photo-sensing performance, owing to the
plasmonic-induced resonance energy transfer effect of the Au core. This effect
led to a significant increase in carrier density between the Au core and CNTS
shell. These values outperformed a CNTS-based gate-free visible photodetector
Production mechanisms and single-spin asymmetry for kaons in high energy hadron-hadron collisions
Direct consequences on kaon production of the picture proposed in a recent
Letter and subsequent publications are discussed. Further evidence supporting
the proposed picture is obtained. Comparison with the data for the inclusive
cross sections in unpolarized reactions is made. Quantitative results for the
left-right asymmetry in single-spin processes are presented.Comment: 10 pages, 2 Postscript figure
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Active RIS in digital twin-based URLLC IoT networks: fully-connected vs. sub-connected?
The substantial power consumption attributed to the active components within fully-connected reconfigurable intelligent surface (RIS) architecture significantly hinders the efficiency and sustainability of DT-enabled MEC networks. To tackle this challenge, we present an innovative sub-connected architecture for active RIS within the digital twin (DT) integrated mobile edge computing (MEC) framework of an Internet-of-Things (IoT) networks, capitalizing on edge intelligence to enhance ultra-reliable and low-latency communication (URLLC) services. The primary aim of our research is to improve uplink data transmission from IoT URLLC user nodes (UNs) to a base station (BS) with the aid of an active RIS, even under an imperfect channel state information (CSI). We have formulated the total end-to-end (e2e) latency minimization problem, which is solved by using an efficient alternating optimization (AO) algorithm. The algorithm breaks down the proposed non-convex problem into five subproblems, namely, beamforming design, caching and offloading policy optimization, joint communication and computation optimization, and joint active RIS phase shift and amplification factor vector optimization. We conducted a thorough analysis of the convergence properties of the proposed AO algorithm, benchmarking its performance against the established Heuristic algorithm. Our simulation results consistently demonstrate the superiority of our proposed DT-assisted optimal phase sub-connected active RIS scheme over various benchmark schemes, taking into account various factors such as the number of RIS elements, power budget constraints, imperfect CSI, edge computing server (ECS) cache capacity, number of IoT UNs, and the number of power amplifiers
The role of mentorship in protege performance
The role of mentorship on protege performance is a matter of importance to
academic, business, and governmental organizations. While the benefits of
mentorship for proteges, mentors and their organizations are apparent, the
extent to which proteges mimic their mentors' career choices and acquire their
mentorship skills is unclear. Here, we investigate one aspect of mentor
emulation by studying mentorship fecundity---the number of proteges a mentor
trains---with data from the Mathematics Genealogy Project, which tracks the
mentorship record of thousands of mathematicians over several centuries. We
demonstrate that fecundity among academic mathematicians is correlated with
other measures of academic success. We also find that the average fecundity of
mentors remains stable over 60 years of recorded mentorship. We further uncover
three significant correlations in mentorship fecundity. First, mentors with
small mentorship fecundity train proteges that go on to have a 37% larger than
expected mentorship fecundity. Second, in the first third of their career,
mentors with large fecundity train proteges that go on to have a 29% larger
than expected fecundity. Finally, in the last third of their career, mentors
with large fecundity train proteges that go on to have a 31% smaller than
expected fecundity.Comment: 23 pages double-spaced, 4 figure
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