bluuebunny/crossref_metadata_2025 huggingface dataset:
Seroprevalence of SARS-CoV-2 infection in healthcare workers in a large teaching hospital in the North West of England: a period prevalence survey
Authors: Shorten Robert John , Haslam Shonagh , Hurley Margaret A , Rowbottom Anthony , Myers M , Wilkinson Paul , Orr David
Published: March 2021

Objectives

Since its emergence in late 2019, SARS-CoV-2 has caused a global pandemic that has significantly challenged healthcare systems. Healthcare workers have previously been shown to have experienced higher rates of infection than the general population. We aimed to assess the extent of infection in staff working in our healthcare setting.

Design

A retrospective analysis of antibody results, compared with staff demographic data, and exposure to patients with COVID-19 infection.

Setting

A large teaching hospital in the North West of England.

Participants

4474 staff in diverse clinical and non-patient facing roles who volunteered for SARS-CoV-2 antibody testing by the Roche Elecsys assay between 29 May and 4 July 2020.

Results

Seroprevalence was 17.4%. Higher rates were seen in Asian/Asian British (OR 1.61, 95% CI 1.27 to 2.04) and Black/Black British (OR 2.08, 95% CI 1.25 to 3.45) staff. Staff working in any clinical location were more likely to be seropositive (OR 2.68, 95% 2.27 to 3.15). Staff were at an increased risk of seropositivity as the ‘per 100 COVID-19 bed-days change’ increased in the clinical area in which they worked (OR 1.12, 95% 1.10 to 1.14). Staff working in critical care were no more likely to have detectable antibodies than staff working in non-clinical areas. Symptoms compatible with COVID-19 were reported in 41.8% and antibodies were detected in 30.7% of these individuals. In staff who reported no symptoms, antibodies were detected in 7.7%. In all staff who had detectable antibodies, 25.2% reported no symptoms.

Conclusions

Staff working in clinical areas where patients with COVID-19 were nursed were more likely to have detectable antibodies. The relationship between seropositivity in healthcare workers and the increase in ‘per 100 COVID-19 bed-days’ of the area in which they worked, although statistically significant, was weak, suggesting other contributing factors to the risk profile. Of staff with detectable antibodies and therefore evidence of prior infection, a quarter self-reported that they had experienced no compatible symptoms. This has implications for potential unrecorded transmission in both staff and patients.
Effectiveness of preoperative tour to a simulated anaesthesia induction at operating theatre in reducing preoperative anxiety in children and their parents: a pragmatic, single-blinded, randomised controlled trial/ King Fahad Medical City
Authors: Battah Hussein , AlZoraigi Usamah , Shubbak Firas
Published: March 2021

Objective

To evaluate the effectiveness of a preoperative tour to a simulated anaesthesia induction at operating theatre on reducing children’s and parents’ preoperative anxiety.

Design

A pragmatic, single-centre, assessor-blinded, randomised controlled trial.

Setting

In preoperative anaesthesia clinic and the operating room at a tertiary care centre in Saudi Arabia.

Participants

One hundred and sixteen children–parents dyads (pairs) (n=57) intervention group (IG); (n=59) control group (CG) with children aged 4–14 years who were planned for day case procedures under general anaesthesia.

Interventions

Participants’ dyads were randomly allocated through a computer to receive either a preoperative tour to a real operating theatre and simulate anaesthesia induction or standard of care.

Main outcome measure

The primary study outcome was children’s anxiety levels as measured by the modified-Yale Preoperative Anxiety Scale (m-YPAS), and the parent’s anxiety level as assessed by the Beck Anxiety Inventory Scale. The children’s anxiety levels were measured at two time points, the preoperative holding area (T0) and before the anaesthesia induction (T1), and the parents’ anxiety level was measured after the anaesthesia induction. The secondary outcomes were the prevalence of preoperative anxiety and children’s somatic signs of anxiety including heart rate and systolic blood pressure.

Results

The Mann-Whitney U test of m-YPAS scores showed significant differences in the children’s anxiety levels between the CG and IG at T0 (Z −5.009); p<0.01) and T1 (Z −6.599); p<0.01). BIAS analysis revealed a significant difference in the parents’ anxiety level between the CG and IG (Z −4.353); p<0.01). The prevalence of children’s anxiety was reported by 55 (93.2%) in the CG compared with 25 (43.9%) in the IG, with a statistically significant difference (p<0.001).

Conclusion

The preoperative simulated anaesthesia induction was effective in reducing preoperative anxiety in children and their parents.
Sexism experienced by consultant cardiologists in the United Kingdom
Authors: Jaijee Shareen Kaur , Kamau-Mitchell Caroline , Mikhail Ghada W , Hendry Cara
Published: March 2021

Objectives

The aims were to compare the frequency with which male and female cardiologists experience sexism and to explore the types of sexism experienced in cardiology.

Methods

A validated questionnaire measuring experiences of sexism and sexual harassment was distributed online to 890 UK consultant cardiologists between March and May 2018. χ2tests and pairwise comparisons with a Bonferroni correction for multiple analyses compared the experiences of male and female cardiologists.

Results

174 cardiologists completed the survey (24% female; 76% male). The survey showed that 61.9% of female cardiologists have experienced discrimination of any kind, mostly related to gender and parenting, compared with 19.7% of male cardiologists. 35.7% of female cardiologists experienced unwanted sexual comments, attention or advances from a superior or colleague, compared with 6.1% of male cardiologists. Sexual harassment affected the professional confidence of female cardiologists more than it affected the confidence of male cardiologists (42.9% vs 3.0%), including confidence with colleagues (38% vs 10.6%) and patients (23.9% vs 4.6%). 33.3% of female cardiologists felt that sexism hampered opportunities for professional advancement, compared with 2.3% of male cardiologists.

Conclusion

Female cardiologists in the UK experience more sexism and sexual harassment than male cardiologists. Sexism impacts the career progression and professional confidence of female cardiologists more, including their confidence when working with patients and colleagues. Future research is urgently needed to test interventions against sexism in cardiology and to protect the welfare of female cardiologists at work.
National movement patterns during the COVID-19 pandemic in New Zealand: the unexplored role of neighbourhood deprivation
Authors: Campbell Malcolm , Marek Lukas , Wiki Jesse , Hobbs Matthew , Sabel Clive E , McCarthy John , Kingham Simon
Published: March 2021

Background

The COVID-19 pandemic has asked unprecedented questions of governments around the world. Policy responses have disrupted usual patterns of movement in society, locally and globally, with resultant impacts on national economies and human well-being. These interventions have primarily centred on enforcing lockdowns and introducing social distancing recommendations, leading to questions of trust and competency around the role of institutions and the administrative apparatus of state. This study demonstrates the unequal societal impacts in population movement during a national ‘lockdown’.

Methods

We use nationwide mobile phone movement data to quantify the effect of an enforced lockdown on population mobility by neighbourhood deprivation using an ecological study design. We then derive a mobility index using anonymised aggregated population counts for each neighbourhood (2253 Census Statistical Areas; mean population n=2086) of national hourly mobile phone location data (7.45 million records, 1 March 2020–20 July 2020) for New Zealand (NZ).

Results

Curtailing movement has highlighted and exacerbated underlying social and spatial inequalities. Our analysis reveals the unequal movements during ‘lockdown’ by neighbourhood socioeconomic status in NZ.

Conclusion

In understanding inequalities in neighbourhood movements, we are contributing critical new evidence to the policy debate about the impact(s) and efficacy of national, regional or local lockdowns which have sparked such controversy.
Effects of targeting the transcription factors Ikaros and Aiolos on B cell activation and differentiation in systemic lupus erythematosus
Authors: Rivellese Felice , Manou-Stathopoulou Sotiria , Mauro Daniele , Goldmann Katriona , Pyne Debasish , Rajakariar Ravindra , Gordon Patrick , Schafer Peter , Bombardieri Michele , Pitzalis Costantino , Lewis Myles J
Published: March 2021

Objective

To evaluate the effects of targeting Ikaros and Aiolos by cereblon modulator iberdomide on the activation and differentiation of B-cells from patients with systemic lupus erythematosus (SLE).

Methods

CD19+B-cells isolated from the peripheral blood of patients with SLE (n=41) were cultured with TLR7 ligand resiquimod ±IFNα together with iberdomide or control from day 0 (n=16). Additionally, in vitro B-cell differentiation was induced by stimulation with IL-2/IL-10/IL-15/CD40L/resiquimod with iberdomide or control, given at day 0 or at day 4. At day 5, immunoglobulins were measured by ELISA and cells analysed by flow cytometry. RNA-Seq was performed on fluorescence-activated cell-sorted CD27-IgD+naïve-B-cells and CD20lowCD27+CD38+plasmablasts to investigate the transcriptional consequences of iberdomide.

Results

Iberdomide significantly inhibited the TLR7 and IFNα-mediated production of immunoglobulins from SLE B-cells and the production of antinuclear antibodies as well as significantly reducing the number of CD27+CD38+plasmablasts (0.3±0.18, vehicle 1.01±0.56, p=0.011) and CD138+plasma cells (0.12±0.06, vehicle 0.28±0.02, p=0.03). Additionally, treatment with iberdomide from day 0 significantly inhibited the differentiation of SLE B-cells into plasmablasts (6.4±13.5 vs vehicle 34.9±20.1, p=0.013) and antibody production. When given at later stages of differentiation, iberdomide did not affect the numbers of plasmablasts or the production of antibodies; however, it induced a significant modulation of gene expression involvingIKZF1andIKZF3transcriptional programmes in both naïve B-cells and plasmablasts (400 and 461 differentially modulated genes, respectively, false discovery rate<0.05).

Conclusion

These results demonstrate the relevance of Ikaros and Aiolos as therapeutic targets in SLE due to their ability to modulate B cell activation and differentiation downstream of TLR7.
Sexual behaviours associated with incident high-risk anal human papillomavirus among gay and bisexual men
Authors: Wong Ian K J , Poynten Isobel Mary , Cornall Alyssa , Templeton David J , Molano Monica , Garland Suzanne M , Fairley Christopher K , Law Carmella , Hillman Richard J , Polizzotto Mark N , Grulich Andrew E , Jin Fengyi
Published: March 2021

Objective

High-risk human papillomavirus (HRHPV) causes anal cancer, which disproportionately affects gay and bisexual men (GBM). We examined sexual behaviours associated with incident anal HRHPV in an observational cohort study of GBM in Sydney, Australia.

Methods

GBM aged 35 years and above were enrolled in the Study of the Prevention of Anal Cancer. Detailed information on sexual practices in the last 6 months, including receptive anal intercourse (RAI) and non-intercourse receptive anal practices, was collected. Anal human papillomavirus (HPV) testing was performed at the baseline and three annual follow-up visits. Risk factors for incident HRHPV were determined by Cox regression using the Wei-Lin-Weissfeld method.

Results

Between 2010 and 2015, 617 men were recruited and 525 who had valid HPV results at baseline and at least one follow-up visit were included in the analysis. The median age was 49 years (IQR 43–56) and 188 (35.8%) were HIV-positive. On univariable analysis, incident anal HRHPV was associated with being HIV-positive (p<0.001), having a higher number of recent RAI partners regardless of condom use (p<0.001 for both), preference for the receptive position during anal intercourse (p=0.014) and other non-intercourse receptive anal sexual practices, including rimming, fingering and receptive use of sex toys (p<0.05 for all). In multivariable analyses, being HIV-positive (HR 1.46, 95% CI 1.09 to 1.85, p=0.009) and reporting condom-protected RAI with a higher number of sexual partners (p<0.001) remained significantly associated with incident HRHPV. When stratified by recent RAI, non-intercourse receptive anal practices were not associated with incident HRHPV in men who reported no recent RAI.

Conclusion

GBM living with HIV and those who reported RAI were at increased of incident anal HRHPV. Given the substantial risk of anal cancer and the difficulty in mitigating the risk of acquiring anal HRHPV, HPV vaccination should be considered among sexually active older GBM.

Trial registration number

ANZCTR365383.
Thermodynamics of the $$R_{\mathrm{h}}=ct$$ Universe: a simplification of cosmic entropy
Authors: Melia Fulvio
Published: March 2021

In the standard model of cosmology, the Universe began its expansion with an anomalously low entropy, which then grew dramatically to much larger values consistent with the physical conditions at decoupling, roughly 380,000 years after the Big Bang. There does not appear to be a viable explanation for this ‘unnatural’ history, other than via thegeneralizedsecond law of thermodynamics (GSL), in which the entropy of the bulk,$$S_\mathrm{bulk}$$Sbulk, is combined with the entropy of the apparent (or gravitational) horizon,$$S_{\mathrm{h}}$$Sh. This is not completely satisfactory either, however, since this approach seems to require an inexplicable equilibrium between the bulk and horizon temperatures. In this paper, we explore the thermodynamics of an alternative cosmology known as the$$R_{\mathrm{h}}=ct$$Rh=ctuniverse, which has thus far been highly successful in resolving many other problems or inconsistencies in$$\varLambda $$ΛCDM. We find that$$S_{\mathrm{bulk}}$$Sbulkis constant in this model, eliminating the so-called initial entropy problem simply and elegantly. The GSL may still be relevant, however, principally in selecting the arrow of time, given that$$S_{\mathrm{h}}\propto t^2$$Sh∝t2in this model.
PCT theorem, Wightman axioms and conformal bootstrap
Authors: Maharana Jnanadeva
Published: March 2021

The axiomatic Wightman formulation for nonderivative conformal field theory is adopted to derive conformal bootstrap equation for the four-point function. The equivalence between PCT theorem and weak local commutativity, due to Jost plays a very crucial role in axiomatic field theory. The theorem is suitably adopted for conformal field theory to derive the desired equations in CFT. We demonstrate that the two Wightman functions are analytic continuation of each other.
在新冠肺炎疫情期間，中國兒童青少年的心理健康狀態與心理健康支持
Authors: 唐 一婷
Published: March 2021

新型冠狀病毒肺炎（COVID-19）是目前影響全球的突發公共衛生事件。從疫情爆發至現階段，新冠肺炎已對各國人民造成了不同程度的身心傷害。兒童青少年作為弱勢群體，在此期間更加需要特別照顧。本文介紹了新冠肺炎疫情期間，中國居家隔離的兒童青少年的心理健康狀況及其主要影響因素。同時，本文還從父母的角度出發，就面對諸如新冠肺炎疫情等此類公共突發事件期間，就如何幫助兒童青少年應對外部環境的不確定性提供了建議和策略。
中觀介入：與商界攜手促進職場共融
Authors: 關 志健 , 劉 惠敏 , 李 彥霖
Published: March 2021

單靠社工一己之力，我們往往不足以促進服務使用者的福祉，所以跨專業合作已成大勢所趨。雖然商界在現今社會扮演重要角色，社工和商界的合作卻不多。本文基於「中觀介入」的概念，探討如何有效與商界合作，令社會達致職場共融。透過整理社工實務經驗，我們提出與商界合作，必須懂得「雙贏」之道。而洽商合作時，社工要運用溝通策略，靈活變通；透過我們專業的表現，贏取商界信任。社工在「中觀」層面加強與商界聯繫，再配合「微觀」和「宏觀」的介入，可幫助企業邁向傷健共融的目標，最終令殘疾人士受惠。
A Theoretical Computer Science Perspective on Consciousness
Authors: Blum Manuel , Blum Lenore
Published: March 2021

The quest to understand consciousness, once the purview of philosophers and theologians, is now actively pursued by scientists of many stripes. This paper studies consciousness from the perspective of theoretical computer science. It formalizes the Global Workspace Theory (GWT) originated by the cognitive neuroscientist Bernard Baars and further developed by him, Stanislas Dehaene, and others. Our major contribution lies in the precise formal definition of a Conscious Turing Machine (CTM), also called a Conscious AI. We define the CTM in the spirit of Alan Turing’s simple yet powerful definition of a computer, the Turing Machine (TM). We are not looking for a complex model of the brain nor of cognition but for a simple model of (the admittedly complex concept of) consciousness. After formally defining CTM, we give a formal definition of consciousness in CTM. We later suggest why the CTM has the feeling of consciousness. The reasonableness of the definitions and explanations can be judged by how well they agree with commonly accepted intuitive concepts of human consciousness, the range of related concepts that the model explains easily and naturally, and the extent of its agreement with scientific evidence.
Chapter 7.1 Deception Island
Authors: Geyer A. , Pedrazzi D. , Almendros J. , Berrocoso M. , López-Martínez J. , Maestro A. , Carmona E. , Álvarez-Valero A. M. , de Gil A.
Published: March 2021

Deception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 15 explosive eruptive events registered over the past two centuries. Recent eruptions (1967, 1969 and 1970) and volcanic unrest episodes in 1992, 1999 and 2014–15 demonstrate that the occurrence of future volcanic activity is a valid and pressing concern for scientists, logistic personnel and tourists that are visiting or are working on or near the island. Over the last few decades, intense research activity has been carried out on Deception Island to decipher the origin and evolution of this very complex volcano. To that end, a solid integration of related scientific disciplines, such as tectonics, petrology, geochemistry, geophysics, geomorphology, remote sensing, glaciology, is required. A proper understanding of the island's evolution in the past, and its present state, is essential for improving the efficiency in interpreting monitoring data recorded during volcanic unrest periods and, hence, for future eruption forecasting. In this chapter, we briefly present Deception Island's most relevant tectonic, geomorphological, volcanological and magmatic features, as well as the results obtained from decades of monitoring the island's seismic activity and ground deformation.
WebRTC - Realtime Communication for the Open Web Platform
Authors: Blum Niklas , Lachapelle Serge , Alvestrand Harald
Published: March 2021

In this time of pandemic, the world has turned to Internet-based, RTC (realtime communication) as never before. The number of RTC products has, over the past decade, exploded in large part because of cheaper high-speed network access and more powerful devices, but also because of an open, royalty-free platform called WebRTC. WebRTC is growing from enabling useful experiences to being essential in allowing billions to continue their work and education, and keep vital human contact during a pandemic. The opportunities and impact that lie ahead for WebRTC are intriguing indeed.
Overview of Quantum Technologies, Standards, and their Applications in Mobile Devices
Authors: Cornet Brian , Fang Hua , Wang Honggang
Published: March 2021

In this paper, we summarize the quantum mechanics that define quantum technologies (quantum states, superposition, entanglement, and decoherence), introduce modern quantum technologies and their broader applications (quantum computing, quantum communication, quantum cryptography, quantum internet, and quantum error correction), examine the state quantum technology standards, and discuss how quantum technologies relate to the mobile world.

For decades, methods for quantum technologies have been theorized or proven mathematically. Real implementations of these methods exist in modern devices such as lasers and magnetic resonance imaging (MRI) scanners. However, the precise manipulation of quantum particles - the fundamentally probabilistic building blocks of our world - is still in its relative infancy, with technologies that depend on manipulation being usable but limited in either function or adoption.
CCAST
Authors: Clark Shane , Usbeck Kyle , Diller David , Schantz Richard E.
Published: March 2021

Individual semi-autonomous unmanned systems have already proven to be useful in a variety of use cases including movie production, agriculture, civil engineering, military operations and insurance [1]. Likewise, small groups of unmanned systems have shown promise, particularly when coordinating to achieve a common goal [3]. Less studied are the potential benefits of large swarms comprising hundreds of capable unmanned systems, likely due to the difficulties associated with creating, or even simulating, such a system. Swarming unmanned systems operate in an environment with a large number of simultaneously moving vehicles, with extensive coordination in real time using mobile communication over a rapidly shifting and dynamic environment. They are often operating in confined areas, moving at speeds of several meters per second, and combining outdoor and indoor coordination.
High-Speed Millimeter-Wave Mobile Experimentation on Software-Defined Radios
Authors: Lacruz Jesus O. , Garcia Dolores , Jimenez Pablo , Palacios Joan , Widmer Joerg
Published: March 2021

Millimeter-wave (mm-Wave) communications have become an integral part of WLAN standards and 5G mobile networks and, as application data rate requirements increase, more and more traffic will move to these very high frequency bands. Although there is an ample choice of powerful experimental platforms for sub-6 GHz research, building mm-Wave systems is much more difficult due to the very high hardware requirements. To address the lack of suitable experimentation platforms, we propose mm-FLEX, a flexible and modular open platform with real-time signal processing capabilities that supports a bandwidth of 2 GHz and is compatible with current mm-Wave standards. The platform is built around a fast FPGA processor and a 60 GHz phased antenna array at front-end that can be reconfigured at nanosecond timescales. Together with its ease of use, this turns the platform into a unique tool for research on beam training in highly mobile scenarios and full-bandwidth mm-Wave signal processing.
ACM fellows and distinguished members in SIGCSE
Authors: Decker Adrienne
Published: March 2021

ACM has recently announced the 2020 Fellows and Distinguished Members
SIGCSE 2021 award winners
Authors: Garcia Dan
Published: March 2021

There are three annual awards SIGCSE bestows on its best and brightest, highlighting outstanding contributions to CS education, lifetime service to the CS education community, and a paper that has had "meaningful impact on computing education practice and research" that has stood the test of time.
SIGCSE 2021 technical symposium
Authors: Sherriff Mark , Merkle Larry
Published: March 2021

The 2021 Technical Symposium is quickly approaching and we could not be more excited to welcome you to the first-ever virtual Symposium! We are equally thrilled by the quality of the program that we have the honor to share with you. The schedule is available at https://sigcse2021.sigcse.org/schedule/.
Distributed Computing Column 81
Authors: Alistarh Dan
Published: March 2021

Overview. In this edition of the column, we have an exciting contribution from Shir Cohen, Idit Keidar, and Oded Naor (Technion), who provide an in-depth perspective on communication-efficient Byzantine Agreement. With the huge popularity of blockchains, the classic area of Byzantine Agreement has seen a surge of interest, and, given the large-scale and widely-distributed deployments of such mechanisms, communication efficiency is a chief concern.

This column provides a gentle introduction to the area, by rst the early work in the 80s. This provides the necessary context for the recent exciting work on communication reduction, from the King & Saia algorithm to Algorand. One very useful feature in this column's contribution is the fact that it provides a uni ed view of these results, along with the mathematical background to understand and di erentiate the underlying results. Many thanks to Shir, Idit and Oded for their contribution!
Signaling, Deconstructed: Using Optogenetics to Dissect and Direct Information Flow in Biological Systems
Authors: Farahani Payam E. , Reed Ellen H. , Underhill Evan J. , Aoki Kazuhiro , Toettcher Jared E.
Published: March 2021

Cells receive enormous amounts of information from their environment. How they act on this information—by migrating, expressing genes, or relaying signals to other cells—comprises much of the regulatory and self-organizational complexity found across biology. The “parts list” involved in cell signaling is generally well established, but how do these parts work together to decode signals and produce appropriate responses? This fundamental question is increasingly being addressed with optogenetic tools: light-sensitive proteins that enable biologists to manipulate the interaction, localization, and activity state of proteins with high spatial and temporal precision. In this review, we summarize how optogenetics is being used in the pursuit of an answer to this question, outlining the current suite of optogenetic tools available to the researcher and calling attention to studies that increase our understanding of and improve our ability to engineer biology.
An Unsupervised Learning Method for the Detection of Genetically Modified Crops Based on Terahertz Spectral Data Analysis
Authors: Pan Shubao , Qin Binyi , Bi Lvqing , Zheng Jincun , Yang Ruizhao , Yang Xiaofeng , Li Yun , Li Zhi
Published: March 2021

Genetically modified crops have been planted commercially on a large scale since 1996. However, the food safety issue of genetically modified crops remains controversial. Conventional genetically modified crops’ detection methods require a plenty of detective time and complex operations that cannot rapidly identify. Previous reports show that combining terahertz time-domain spectroscopy and supervised learning has advanced to identify genetically modified crops, but supervised learning requires large data to train the model. To solve the above problem, we proposed an unsupervised learning method, PCA-mean shift, to identify genetically modified crops. Principal component analysis was employed to reduce the absorbance data dimensionality. After principal component analysis, the first three principal components were used as the input of mean shift. At last, our proposed method had 100% identification accuracy, and K-means had 98.75% identification accuracy. The comparison results demonstrated that PCA-mean shift outperforms K-means. Therefore, PCA-mean shift combined with terahertz time-domain spectroscopy is a potential identification tool for genetically modified crops’ identification.
Data Dependence, Strict Fixed Point Results, and Well-Posedness of Multivalued Weakly Picard Operators
Authors: Hussain Azhar , Ali Ahsan , Parvaneh Vahid , Aydi Hassen
Published: March 2021

In this paper, we introduce the notion of

s
,
r

-contractive multivalued weakly Picard operators via simulation functions, named as

Z

s
,
r

-contractions. We present some related fixed point theorems. We investigate data dependence and strict fixed point results. The well-posedness for such operators is also considered. Moreover, we generalize the results of Moţ and Petruşel. To show the usability of our results, we give some examples and an application to resolve a functional equation arising in dynamical systems.
Enhancing Steady-State Entanglement Generated by a Nondegenerate Three-Level Laser with Thermal Reservoir
Authors: Abebe Tamirat , Yirgashewa Tewodros , Belay Abebe
Published: March 2021

We analyze a nondegenerate three-level cascade laser with an open cavity and coupled to a two-mode thermal reservoir employing the stochastic differential equations for atomic operators associated with the normal ordering. Applying the large-time approximation scheme, we obtain the solutions for the corresponding equations of evolution of the expectation values of atomic operators. Furthermore, employing the resulting solutions, we studied the photon as well as cavity atomic-state entanglement amplification of the cavity radiation.
Numerical Investigation of Wellbore Stability in Deepwater Shallow Sediments
Authors: Liu Wei , Lin Hai , Liu Hailong , Luo Chao , Wang Guiping , Deng Jingen
Published: March 2021

An elaborate poro-elastoplastic numerical model has been developed in this paper to explore the stability characteristics of wellbore in shallow sediments of deepwater oil/gas wells. The combined Drucker-Prager/cap plasticity model is employed to characterize the mechanical behavior of the weakly consolidated or unconsolidated shallow sediments, by which both plastic compaction deformation and plastic shear deformation can be considered. Possible penetration of drilling fluid into the formation and its coupling to deformation have also been accounted for in the model. Using this model, deformation, stress evolution, and failure characteristics of the formation around the wellbore are analyzed in detail. Results presented in this paper demonstrate the necessity of considering the plastic compaction capability of the formation during the wellbore stability analysis of shallow sediments in deepwater. For mud pressures lower than the in situ horizontal stress, excessive wellbore shrinkage may occur if the mud pressure is too low, which, however, can be effectively mitigated through properly increasing the mud pressure even fluid penetration into the near-wellbore region may occur. It is also evidenced that, if penetration of drilling fluid into the formation is prevented, fracturing of the wellbore will not occur even the mud pressure is very high. Instead, the wellbore will expand substantially due to plastic compaction, and the deformed wellbore radius could be several times larger than the original value. However, if drilling fluid can penetrate into the formation, high pore pressure will develop within the near-wellbore region, resulting in tensile hoop stress at the wellbore and thus fracturing of the wellbore along the radial direction. The numerical results and implications in this paper are anticipated to be beneficial for the drilling operation in the shallow portion of deepwater oil/gas wells.
Multiobjective Sensor Ontology Matching Technique with User Preference Metrics
Authors: Zhu Hai , Xue Xingsi , Jiang Chengcai , Ren He
Published: March 2021

Due to the problem of data heterogeneity in the semantic sensor networks, the communications among different sensor network applications are seriously hampered. Although sensor ontology is regarded as the state‐of‐the‐art knowledge model for exchanging sensor information, there also exists the heterogeneity problem between different sensor ontologies. Ontology matching is an effective method to deal with the sensor ontology heterogeneity problem, whose kernel technique is the similarity measure. How to integrate different similarity measures to determine the alignment of high quality for the users with different preferences is a challenging problem. To face this challenge, in our work, a Multiobjective Evolutionary Algorithm (MOEA) is used in determining different nondominated solutions. In particular, the evaluating metric on sensor ontology alignment’s quality is proposed, which takes into consideration user’s preferences and do not need to use the Reference Alignment (RA) beforehand; an optimization model is constructed to define the sensor ontology matching problem formally, and a selection operator is presented, which can make MOEA uniformly improve the solution’s objectives. In the experiment, the benchmark from the Ontology Alignment Evaluation Initiative (OAEI) and the real ontologies of the sensor domain is used to test the performance of our approach, and the experimental results show the validity of our approach.
Hyperbaric Oxygen Improves Cerebral Ischemia/Reperfusion Injury in Rats Probably via Inhibition of Autophagy Triggered by the Downregulation of Hypoxia‐Inducing Factor‐1 Alpha
Authors: Wang Cuiting , Niu Feng , Ren Ningna , Wang Xiaokun , Zhong Hequan , Zhu Jie , Li Bing
Published: March 2021

Ischemic stroke, accompanied with high mortality and morbidity, may produce heavy economic burden to societies and families. Therefore, it is of great significance to explore effective therapies. Hyperbaric oxygen (HBO) is a noninvasive, nondrug treatment method that has been proved able to save ischemic penumbra by improving hypoxia, microcirculation, and metabolism and applied in various ischemic diseases. Herewith, we fully evaluated the effect of HBO on ischemic stroke and investigated its potential mechanism in the rat ischemia/reperfusion(I/R) model. Sixty Sprague‐Dawley male rats were randomly divided into three groups—sham group, MCAO group, and MCAO+HBO group. In the latter two groups, the middle cerebral artery occlusion was performed (MCAO) for 2 hours, and then the occlusion was removed in order to establish the ischemic/reperfusion model. Subsequently, HBO was performed immediately after I/R (2 hours per day for 3 days). 72 hours after MCAO, the brain was dissected for our experiment. Finally, the data from three groups were analyzed by one‐way analysis of variance (ANOVA) and followed by a Bonferroni test. In this article, we reported that HBO effectively reduced the infarction and edema and improved neurological functions to a certain extent. As shown by western blot analysis, HBO significantly reduced autophagy by regulating autophagy‐related proteins (mTOR, p‐mTOR, Atg13, LC3B II and LC3B II) in the hippocampus 72 hours after I/R, which was accompanied by inhibiting the expression of hypoxia inducible factor‐1α (HIF‐1α) in hippocampus. The results suggest that HBO may improve cerebral I/R injury, possibly via inhibiting HIF‐1α, the upstream molecule of autophagy, and therefore, subsequently inhibiting autophagy in the rat model of ischemic stroke.
Pore Properties of the Lacustrine Shale in the Upper Part of the Sha-4 Member of the Paleogene Shahejie Formation in the Dongying Depression in East China
Authors: Wang Ziyi , Zhang Liuping , Gao Yuan , Yang Wenxiu , Wang Yongshi , Liu Huimin , Li Zhaoyang , Zhou Shanshan
Published: March 2021

Lacustrine shales hold a huge potential oil resource in China. Pore properties (pore volume, diameter, specific surface area, and fractal dimensions) and their relationships with geological factors (mineralogy, insoluble organic carbon, burial depth, and vitrinite reflectance) are critical for evaluating shale oil resource. However, the factors controlling pores for lacustrine shale oil remain unclear, as the relationships between pore properties of Soxhlet-extracted samples and geological factors have not been studied using multivariate analytical methods. In this paper, the samples from the lacustrine shale in the upper part of the Sha-4 Member of the Paleogene Shahejie Formation in the Dongying Depression were tested with a set of experiments including Soxhlet (solvent) extraction, X-ray diffraction mineral analysis, insoluble organic carbon, vitrinite reflectance, and low-pressure CO2 and N2 adsorption experiments. The micromesopore volume varies from 0.003 cm3/g to 0.045 cm3/g. The relationships of pore properties with geological factors were studied with partial least square regression analysis (PLSR analysis, a powerful multivariate regression analysis). The results of the PLSR analyses indicate that clay minerals and carbonates are two key factors affecting the pore properties of the lacustrine shale. Compared with marine shales, more clay minerals in the lacustrine shale make them become more important for controlling pores than organic matter. The PLSR results also illustrate that the shale with higher pore volume contains more clay minerals and fewer carbonates and thus is unfavorable for hydraulic fracturing. Therefore, the shale with high micromesopore volume may be unfavorable for shale oil production. The shale with the modest micromesopore volume (~0.036 cm3/g), relatively high content of brittle minerals (~71 wt%), and low clay mineral content (~29 wt%) is conducive to both oil storage and hydraulic fracturing for the development of the Es4U shale oil in the Dongying Depression in East China.
An Efficient SMOTE-Based Deep Learning Model for Heart Attack Prediction
Authors: Waqar Muhammad , Dawood Hassan , Dawood Hussain , Majeed Nadeem , Banjar Ameen , Alharbey Riad
Published: March 2021

Cardiac disease treatments are often being subjected to the acquisition and analysis of vast quantity of digital cardiac data. These data can be utilized for various beneficial purposes. These data’s utilization becomes more important when we are dealing with critical diseases like a heart attack where patient life is often at stake. Machine learning and deep learning are two famous techniques that are helping in making the raw data useful. Some of the biggest problems that arise from the usage of the aforementioned techniques are massive resource utilization, extensive data preprocessing, need for features engineering, and ensuring reliability in classification results. The proposed research work presents a cost-effective solution to predict heart attack with high accuracy and reliability. It uses a UCI dataset to predict the heart attack via various machine learning algorithms without the involvement of any feature engineering. Moreover, the given dataset has an unequal distribution of positive and negative classes which can reduce performance. The proposed work uses a synthetic minority oversampling technique (SMOTE) to handle given imbalance data. The proposed system discarded the need of feature engineering for the classification of the given dataset. This led to an efficient solution as feature engineering often proves to be a costly process. The results show that among all machine learning algorithms, SMOTE-based artificial neural network when tuned properly outperformed all other models and many existing systems. The high reliability of the proposed system ensures that it can be effectively used in the prediction of the heart attack.
An Extension of the Picard Theorem to Fractional Differential Equations with a Caputo-Fabrizio Derivative
Authors: Marasi H. R. , Joujehi A. Soltani , Aydi H.
Published: March 2021

In this paper, we consider fractional differential equations with the new fractional derivative involving a nonsingular kernel, namely, the Caputo-Fabrizio fractional derivative. Using a successive approximation method, we prove an extension of the Picard-Lindelöf existence and uniqueness theorem for fractional differential equations with this derivative, which gives a set of conditions, under which a fractional initial value problem has a unique solution.
A Novel Evaluation Method for Detecting Defects of the Bonded Orthodontic Bracket‐Tooth Interface
Authors: Abbassy Mona Aly , Bakhsh Turki A. , Bakry Ahmed Samir
Published: March 2021

Background. Orthodontic patients are at high risk to develop caries. This study is introducing a clinical method detecting interfacial defects between ceramic brackets and enamel utilizing optical coherent tomography in addition to using the nanoleakage expression in vitro test. Methods. Transbond XT primer and moisture insensitive primer (MIP) were bonded to 75 human premolar enamel surfaces and divided into (XTD), (MIPD), and (MIPW) groups. The (XTD) and (MIPD) groups had ceramic brackets bonded to dry enamel surfaces using TransBond and moisture insensitive primers, respectively, while the (MIPW) samples were bonded to moist enamel using moisture insensitive primer. All specimens were examined under crosspolarization optical coherence tomography. Debonding forces of the brackets to 45 teeth (15 teeth/group). 30 bonded specimens (15 specimens/group) were cross‐sectioned to detect the nanoleakage expression using scanning electron microscope equipped with energy‐dispersive spectroscopy (SEM/EDS). The degree of conversion of the specimens in the experimental groups was tested using attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR). Results. Optical coherence tomography detected the interfacial defects between the ceramic brackets and tooth structure. One way ANOVA showed that (XTD) and (MIPD) groups recorded significantly higher bond strength values and less nanoleakage expression when compared to MIPW (p > 0.05). Conclusions. Optical coherence tomography can be utilized to detect interfacial adhesive‐tooth defects. Dry enamel surfaces improve the quality of the enamel/primer interface (200 words).
Meta‐analysis: Early Age at Natural Menopause and Risk for All‐Cause and Cardiovascular Mortality
Authors: Huan Luyao , Deng Xiangling , He Mengyang , Chen Shunhong , Niu Wenquan
Published: March 2021

Aims. The aim of this meta‐analysis was to comprehensively evaluate the association of early age at natural menopause with the risk for all‐cause and cardiovascular mortality. Methods. Literature retrieval was done on August 4, 2020. Article selection and data extraction were completed independently and in duplicate. Early age at natural menopause was grouped into premature menopause (<40 years), early menopause (40‐44 years), and relatively early menopause (45‐49 years). Effect‐size estimates are summarized as hazard ratio (HR) or relative risk (RR) with 95% confidence interval (CI). Results. Sixteen articles involving 321,233 women were meta‐analyzed. Overall analyses revealed a statistically significant association of early age at natural menopause with all‐cause mortality risk (HRadjusted = 1.08, 95% CI: 1.03 to 1.14, P = 0.002; RRadjusted = 1.05, 95% CI 1.01 to 1.08, P = 0.005), but not with cardiovascular mortality risk. In dose‐response analyses, the association with all‐cause mortality was significant for premature menopause with (HRadjusted = 1.10; 95% CI: 1.01 to 1.21; P = 0.034) and without (RRadjusted = 1.34; 95% CI: 1.08 to 1.66; P = 0.007) considering follow‐up intervals. As for cardiovascular mortality, marginal significance was noted for premature menopause after considering follow‐up intervals (HR = 1.09; 95% CI: 1.00‐1.19; P = 0.045). Subgroup analyses indicated that gender, country, and follow‐up periods were possible causes of heterogeneity. There was an overall low probability of publication bias. Conclusions. Our findings indicate that premature menopause is a promising independent risk factor for both all‐cause and cardiovascular mortality.
Ventriculocoronary Fistulas with Hypoplastic Left Heart in a Neonate: Imaging with Cardiac CT
Authors: Baş Serap , Alkara Utku
Published: March 2021

Fistulous communications between the ventricular cavities and the coronary arterial tree can be found in the presence of hypoplasia of the left ventricle, especially when the ventricular septum is intact and mitral stenosis and aortic atresia subtype are present. The cardiac CT provides excellent anatomic information especially in the evaluation of extracardiac vessels and coronary arteries. In this case study, we report a newborn with ventriculocoronary fistulas (VCFs) with the hypoplastic left disease diagnosed with cardiac CT. Transthoracic echocardiography of a term baby showed hypoplastic left heart syndrome (HLHS) with mitral stenosis and aortic atresia. The patient immediately underwent a Sano variation of the Norwood procedure. On the postoperative second day, the clinical status of the patient deteriorated. A prospective electrocardiogram-gated axial technique was performed within a single heartbeat for the patient and large VCFs were detected and a second operation were performed to close the VCFs that failed. On the nineteenth day after the operation, the baby passed away. According to us, cardiac CT can also be performed free-breathing and without anesthesia in the neonatal period for the definition of complex cardiac anatomy with the lower radiation dose from the latest scanners, radiation risk of CT should be weighed against the anesthesia risk of cardiac MRI and intraoperative risk of conventional cardiac angiography. Pre-operative cardiac CT may increase surgical success.
Exposure of Mesenchymal Stem Cells to an Alzheimer’s Disease Environment Enhances Therapeutic Effects
Authors: Park Sang Eon , Kim Hyeong Seop , Kwon Soo Jin , Kim Min-Jeong , Choi Suk-joo , Oh Soo-young , Ryu Gyu Ha , Jeon Hong Bae , Na Duk L. , Chang Jong Wook
Published: March 2021

Mesenchymal stem cells (MSCs) have emerged as a promising tool for the treatment of Alzheimer’s disease (AD). Previous studies suggested that the coculture of human MSCs with AD in an in vitro model reduced the expression of amyloid-beta 42 (Aβ42) in the medium as well as the overexpression of amyloid-beta- (Aβ-) degrading enzymes such as neprilysin (NEP). We focused on the role of primed MSCs (human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) exposed to an AD cell line via a coculture system) in reducing the levels of Aβ and inhibiting cell death. We demonstrated that mouse groups treated with naïve MSCs and primed MSCs showed significant reductions in cell death, ubiquitin conjugate levels, and Aβ levels, but the effects were greater in primed MSCs. Also, mRNA sequencing data analysis indicated that high levels of TGF-β induced primed-MSCs. Furthermore, treatment with TGF-β reduced Aβ expression in an AD transgenic mouse model. These results highlighted AD environmental preconditioning is a promising strategy to reduce cell death and ubiquitin conjugate levels and maintain the stemness of MSCs. Further, these data suggest that human WJ-MSCs exposed to an AD environment may represent a promising and novel therapy for AD.
Related Fixed Point Theorems in Partially Ordered
b
-Metric Spaces and Applications to Integral Equations
Authors: Errai Youssef , Marhrani El Miloudi , Aamri Mohamed
Published: March 2021

In this research paper, we have set some related fixed point results for generalized weakly contractive mappings defined in partially ordered complete

b

-metric spaces. Our results are an extension of previous authors who have already worked on fixed point theory in

b

-metric spaces. We state some examples and one sample of the application of the obtained results in integral equations, which support our results.
[Retracted] Study on Damage Mechanism and Repair of Vascular Endothelial Cells Based on Ultrasound Technology
Authors: Deng Shuhao , Jiang Quan , Lu Xin , Zhang Yuan
Published: March 2021

Objective. To detect the endothelial function of external iliac artery in rats with different stages of atherosclerosis by high‐resolution ultrasound, so as to provide experimental methodological basis for evaluating the function of vascular endothelial cells by ultrasound. Methods. The animals were randomly divided into the control group (n = 6) and the atherosclerosis model group (n = 15). The atherosclerosis group was further divided into 4‐week group, 8‐week group, and 12‐week group, with 5 animals in each group. After separating and grinding rat spleen, the obtained cells were cultured by density gradient centrifugation. After the cells adhered, the morphology of the cells was observed under a microscope and identified by DiI‐Ac‐LDL and FITC‐UEA‐I double staining. The activities of LDH and SOD, the contents of MDA and GSH, and the contents of NO in plasma were detected by biochemical methods. Results. The protective effect of rosanilin on brain injury in rats with acute hypobaric hypoxia and its regulation on the expression of pAkt protein; ox‐LDL inhibited the proliferation activity of EPCs in a concentration‐dependent manner. The expression of KLF2 and S1PR1 in HAEC can be knocked down by small interfering RNA, and knocking down KLF2 can not only downregulate the expression of S1PR1 but also downregulate HAVEN. With the development of atherosclerosis, the endothelium‐dependent relaxation function and endothelium‐independent relaxation function of the control group and the atherosclerosis model at 4, 8, and 12 weeks were damaged in different degrees and gradually aggravated. Conclusion. Atherosclerosis is a disease with both morphological and functional damage, and vascular endothelial function is damaged in the early stage with corresponding pathological changes. Ultrasound is an effective method to evaluate vascular endothelial function.