bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Likelihood Ratio Method for Training Artificial Neural Networks
Authors: Peng Yijie , Xiao Li , Heidergott Bernd , Hong L. Jeff , Lam Henry 
Published: September 2021

We investigate a new approach to compute the gradients of artificial neural networks (ANNs), based on the so-called push-out likelihood ratio method. Unlike the widely used backpropagation (BP) method that requires continuity of the loss function and the activation function, our approach bypasses this requirement by injecting artificial noises into the signals passed along the neurons. We show how this approach has a similar computational complexity as BP, and moreover is more advantageous in terms of removing the backward recursion and eliciting transparent formulas. We also formalize the connection between BP, a pivotal technique for training ANNs, and infinitesimal perturbation analysis, a classic path-wise derivative estimation approach, so that both our new proposed methods and BP can be better understood in the context of stochastic gradient estimation. Our approach allows efficient training for ANNs with more flexibility on the loss and activation functions, and shows empirical improvements on the robustness of ANNs under adversarial attacks and corruptions of natural noises. Summary of Contribution: Stochastic gradient estimation has been studied actively in simulation for decades and becomes more important in the era of machine learning and artificial intelligence. The stochastic gradient descent is a standard technique for training the artificial neural networks (ANNs), a pivotal problem in deep learning. The most popular stochastic gradient estimation technique is the backpropagation method. We find that the backpropagation method lies in the family of infinitesimal perturbation analysis, a path-wise gradient estimation technique in simulation. Moreover, we develop a new likelihood ratio-based method, another popular family of gradient estimation technique in simulation, for training more general ANNs, and demonstrate that the new training method can improve the robustness of the ANN.
Ambiguity and the Tradeoff Theory of Capital Structure
Authors: Izhakian Yehuda , Yermack David , Zender Jaime F. 
Published: September 2021

We examine the impact of ambiguity, or Knightian uncertainty, on the capital structure decision, using a static tradeoff theory model in which agents are both ambiguity and risk averse. The model confirms the well-known result that greater risk—the uncertainty over outcomes—leads firms to decrease leverage. Conversely, the model indicates that greater ambiguity—the uncertainty over the probabilities associated with the outcomes—leads firms to increase leverage. Using a theoretically based measure of ambiguity, our empirical analysis presents evidence consistent with these notions, showing that ambiguity has an important and distinct impact on capital structure. This paper was accepted by Gustavo Manso, finance.
Liquid reconfigurable stealth window constructed by a metamaterial absorber
Authors: Kong Xiangkun , Lin Weihao , Wang Xuemeng , Xing Lei , Jiang Shunliu , Kong Lingqi , Liu Meilin 
Published: September 2021

In this paper, a liquid reconfigurable stealth window constructed by a metamaterial absorber at the microwave band is proposed. The stealth window consists of an anti-reflection glass with indium tin oxide (ITO) as resistive film and a liquid container made of polymethyl methacrylate (PMMA). Since the materials constituting the window are all optically transparent, the metamaterials that can be switched through the liquid control system can always maintain high light transmission. The proposal can obtain a transmission passband from 2.3 GHz to 5 GHz with low insertion loss, especially at 2.45 GHz and 5 GHz with the insertion loss of the passband reaching 0.51 dB and 0.99 dB, by water with 75% ethanol drainage. It can also reflect electromagnetic waves at 2.45 GHz and absorb them from 4.5 GHz to 10.5 GHz with a strong absorptivity over 90% by ethanol injection, exhibiting the reconfigurable electromagnetic characteristic of switching between the transmission state and absorption state. Furthermore, the proposed absorber shows its good transmission/absorption performance. Under the condition of ethanol filling, when electromagnetic waves are incident obliquely at 50°, the absorption rate still exceeds 80%. Finally, the prototype window has been fabricated to demonstrate the validity of the proposed structure, which indicates that the proposal presents significant implications for smart stealth systems and wireless local area network (WLAN) communication that require switching of working states in a complex electromagnetic environment.
Hierarchy and control of ageing-related methylation networks
Authors: Palla Gergely , Pollner Péter , Börcsök Judit , Major András , Molnár Béla , Csabai István 
Published: September 2021

DNA methylation provides one of the most widely studied biomarkers of ageing. Since the methylation of CpG dinucleotides function as switches in cellular mechanisms, it is plausible to assume that by proper adjustment of these switches age may be tuned. Though, adjusting hundreds of CpG methylation levels coherently may never be feasible and changing just a few positions may lead to biologically unstable state.A prominent example of methylation-based age estimators is provided by Horvath’s clock, based on 353 CpG dinucleotides, showing a high correlation (not necessarily causation) with chronological age across multiple tissue types. On this small subset of CpG dinucleotides we demonstrate how the adjustment of one methylation level leads to a cascade of changes at other sites. Among the studied subset, we locate the most important CpGs (and related genes) that may have a large influence on the rest of the sub-system. According to our analysis, the structure of this network is way more hierarchical compared to what one would expect based on ensembles of uncorrelated connections. Therefore, only a handful of CpGs is enough to modify the system towards a desired state.When propagation of the change over the network is taken into account, the resulting modification in the predicted age can be significantly larger compared to the effect of isolated CpG perturbations. By adjusting the most influential single CpG site and following the propagation of methylation level changes we can reach up to 5.74 years in virtual age reduction, significantly larger than without taking into account of the network control. Extending our approach to the whole methylation network may identify key nodes that have controller role in the ageing process.
Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients with diabetes at the Korle Bu Teaching Hospital
Authors: Anafo Ramzy B. , Atiase Yacoba , Kotey Fleischer C. N. , Dayie Nicholas T. K. D. , Tetteh-Quarcoo Patience B. , Duodu Samuel , Osei Mary-Magdalene , Alzahrani Khalid J. , Donkor Eric S. 
Published: September 2021

AimTo investigate the epidemiology ofS.aureusand MRSA nasal carriage among people with diabetes at the Korle Bu Teaching Hospital in Accra, including the prevalence, predictors of carriage, and antibiotic resistance.MethodologyThis study was cross-sectional, involving 300 diabetes patients and 106 non-diabetic individuals. Swab specimens of the nares were obtained from the participants and bacteriologically-cultured. Identification and characterization ofS.aureusand MRSA were based on standard bacteriological methods; antimicrobial susceptibility testing was by the Kirby-Bauer method.ResultsThe prevalence of staphylococcal carriage, the diabetes group relative to the non-diabetes group, were 31.0% and 10.4% (S.aureus), and 3.3% and 0.0% (MRSA). Presence of diabetes predisposed toS.aureuscarriage, but not MRSA nor coagulase-negative staphylococci (CoNS) carriage (OR= 3.88;p< 0.0001). Colonization with CoNS was protective ofS.aureus(OR= 0.039,p <0.001) and MRSA (OR= 0.115,p =0.043) colonization among the diabetics. The antimicrobial resistance patterns recorded among theS.aureusisolated from the diabetic individuals relative to the non-diabetics were as follows: penicillin (95% vs. 91%), tetracycline (37% vs. 27%), cotrimoxazole (30% vs. 36%), erythromycin (17% vs. 0%), norfloxacin (13% vs. 0%), clindamycin (12% vs. 0%), gentamicin (9% vs. 0%), fusidic acid (10% vs. 9%), linezolid (4% vs. 0%), and rifampicin (5% vs. 0%). The proportion of multidrug resistantS.aureuswas 41% (n= 38) in the diabetes group and 0% in the non-diabetes group; this difference was statistically significant (p= 0.01).ConclusionsThe presence of diabetes predisposed the participants toS.aureuscarriage by almost four folds, but not MRSA carriage. Colonization with CoNS was protective ofS.aureusand MRSA carriage in the diabetes group. Finally, linezolid remains a good therapeutic agent for anti-MRSA therapy.
Performance of COVID-19 associated symptoms and temperature checking as a screening tool for SARS-CoV-2 infection
Authors: Nuertey Benjamin Demah , Ekremet Kwame , Haidallah Abdul-Rashid , Mumuni Kareem , Addai Joyce , Attibu Rosemary Ivy E. , Damah Michael C. , Duorinaa Elvis , Seidu Anwar Sadat , Adongo Victor C. , Adatsi Richard Kujo , Suri Hisyovi Caedenas , Komei Abass Abdul-Karim , Abubakari Braimah Baba , Weyori Enoch , Allegye-Cudjoe Emmanuel , Sylverken Augustina , Owusu Michael , Phillips Richard O. 
Published: September 2021

Introduction
Coronavirus disease-19 (COVID-19), which started in late December, 2019, has spread to affect 216 countries and territories around the world. Globally, the number of cases of SARS-CoV-2 infection has been growing exponentially. There is pressure on countries to flatten the curves and break transmission. Most countries are practicing partial or total lockdown, vaccination, massive education on hygiene, social distancing, isolation of cases, quarantine of exposed and various screening approaches such as temperature and symptom-based screening to break the transmission. Some studies outside Africa have found the screening for fever using non-contact thermometers to lack good sensitivity for detecting SARS-CoV-2 infection. The aim of this study was to determine the usefulness of clinical symptoms in accurately predicting a final diagnosis of COVID-19 disease in the Ghanaian setting.

Method
The study analysed screening and test data of COVID-19 suspected, probable and contacts for the months of March to August 2020. A total of 1,986 participants presenting to Tamale Teaching hospital were included in the study. Logistic regression and receiver operator characteristics (ROC) analysis were carried out.

Results
Overall SARS-CoV-2 positivity rate was 16.8%. Those with symptoms had significantly higher positivity rate (21.6%) compared with asymptomatic (17.0%) [chi-squared 15.5, p-value, <0.001]. Patients that were positive for SARS-CoV-2 were 5.9 [3.9–8.8] times more likely to have loss of sense of smell and 5.9 [3.8–9.3] times more likely to having loss of sense of taste. Using history of fever as a screening tool correctly picked up only 14.8% of all true positives of SARS-CoV-2 infection and failed to pick up 86.2% of positive cases. Using cough alone would detect 22.4% and miss 87.6%. Non-contact thermometer used alone, as a screening tool for COVID-19 at a cut-off of 37.8 would only pick 4.8% of positive SARS-CoV-2 infected patients.

Conclusion
The use of fever alone or other symptoms individually [or in combination] as a screening tool for SARS-CoV-2 infection is not worthwhile based on ROC analysis. Use of temperature check as a COVID-19 screening tool to allow people into public space irrespective of the temperature cut-off is of little benefit in diagnosing infected persons. We recommend the use of facemask, hand hygiene, social distancing as effective means of preventing infection.
Fidelity of implementation of TB screening guidelines by health providers at selected HIV clinics in Ghana
Authors: Narh-Bana Solomon A. , Kawonga Mary , Chirwa Esnat D. , Ibisomi Latifat , Bonsu Frank , Chirwa Tobias F. 
Published: September 2021

Introduction
Tuberculosis screening of people living with human immunodeficiency virus is an intervention recommended by the WHO to control the dual epidemic of TB and HIV. The extent to which the intervention is adhered to by the HIV healthcare providers (fidelity) determines the intervention’s effectiveness as measured by patient outcomes, but literature on fidelity is scarce. This study assessed provider implementation fidelity to national guidelines on TB screening at HIV clinics in Ghana.

Methods
It was a cross-sectional study that used structured questionnaires to gather data, involving 226 of 243 HIV healthcare providers in 27 HIV clinics across Ghana. The overall fidelity score comprised sixteen items with a maximum score of 48 grouped into three components of the screening intervention (TB diagnosis, TB awareness and TB symptoms questionnaire). Simple summation of item scores was done to determine fidelity score per provider. In this paper, we define the level of fidelity as low if the scores were below the median score and were otherwise categorized as high. Background factors potentially associated with implementation fidelity level were assessed using cluster-based logistic regression. Odds ratio with 95% confidence interval (CI) was used as the measure of association.

Results
Of the 226 healthcare providers interviewed, 60% (135) were females with a mean age of 34.5 years (SD = 8.3). Most of them were clinicians [63% (142)] and had post-secondary non-tertiary education [62% (141)]. Overall, 53% (119) of the healthcare providers were categorized to have implemented the intervention with high fidelity. Also, 56% (126), 53% (120), and 59% (134) of the providers implemented the TB diagnosis, TB awareness and TB symptoms questionnaire components respectively with high fidelity. After adjusting for cluster effect, female providers (AOR = 2.36, 95%CI: 1.09–5.10, p = <0.029), those with tertiary education (AOR = 4.31, 95%CI: 2.12–9.10, p = 0.040), and clinicians (AOR = 1.78, 95%CI: 1.07–3.50, p = 0.045) were more likely to adhere to the guidelines compared to their counterparts.

Conclusion
The number of providers with fidelity scores above the median was marginally greater (6%) than the number with fidelity score below the median. Similarly, for each of the components, the number of providers with fidelity scores higher than the median was marginally higher. This could explain the existing fluctuations in the intervention outcomes in Ghana. We found gender, profession and education were associated with provider implementation fidelity. To improve fidelity level among HIV healthcare providers, and realize the aims of the TB screening intervention among PLHIV in Ghana, further training on implementing all components of the intervention is critical.
Time-of-day changes in physician clinical decision making: A retrospective study
Authors: Trinh Peter , Hoover Donald R. , Sonnenberg Frank A. 
Published: September 2021

Background
Time of day has been associated with variations in certain clinical practices such as cancer screening rates. In this study, we assessed how more general process measures of physician activity, particularly rates of diagnostic test ordering and diagnostic assessments, might be affected by time of day.

Methods
We conducted a retrospective chart review of 3,342 appointments by 20 attending physicians at five outpatient clinics, matching appointments by physician and comparing the average diagnostic tests ordered and average diagnoses assessed per appointment in the first hour of the day versus the last hour of the day. Statistical analyses used sign tests, two-sample t-tests, Wilcoxon tests, Kruskal Wallis tests, and multivariate linear regression.

Results
Examining physicians individually, four and six physicians, respectively, had statistically significant first- versus last-hour differences in the number of diagnostic tests ordered and number of diagnoses assessed per patient visit (p ≤ 0.04). As a group, 16 of 20 physicians ordered more tests on average in the first versus last hour (p = 0.012 for equal chance to order more in each time period). Substantial intra-clinic heterogeneity was found in both outcomes for four of five clinics (p < 0.01).

Conclusions
There is some statistical evidence on an individual and group level to support the presence of time-of-day effects on the number of diagnostic tests ordered per patient visit. These findings suggest that time of day may be a factor influencing fundamental physician behavior and processes. Notably, many physicians exhibited significant variation in the primary outcomes compared to same-specialty peers. Additional work is necessary to clarify temporal and inter-physician variation in the outcomes of interest.
An E-band Variable Gain Amplifier with 24 dB-control range and 80 to 100 GHz 1 dB bandwidth in SiGe BiCMOS technology
Authors: Centurelli Francesco , Monsurrò Pietro , Scotti Giuseppe , Tommasino Pasquale , Trifiletti Alessandro 
Published: September 2021

Abstract
Analysis, design, and characterization of an E-band Variable Gain Amplifier (VGA) in SiGe BiCMOS commercial technology is presented. VGA topologies are compared in terms of their capability to contribute to receiver linearity and dynamic range. The proposed VGA is based on a Gilbert multiplier cell exploiting current cancellation to enhance control range and linearity. A 1 dB bandwidth ranging from 80 to 100 GHz, a 24 dB gain control range and a −11.5 dBm input 1 dB compression point have been measured.
Highly efficient photo-degradation of cetirizine antihistamine with TiO2-SiO2 photocatalyst under ultraviolet irradiation
Authors: Rani Sonam , Garg Alok , Singh Neetu 
Published: September 2021

Abstract
Photocatalysis is an extraordinary and vastly researched topic; there is a need to find new ways to support producing composite materials that are cost-effective, efficient and have a low environmental impact. The investigation was undertaken on syn TiO2 by depositing it on silica. The results elucidate the positive effect on photocatalysis activity and the macroscopic structure on which the TiO2 is formed. For the analysis of photocatalyst, various characterisation measurements were undertaken, such as XRD, FTIR, DRS, FESEM, TEM, RS, and BET. The accumulated TiO2 onto the surface of SiO2 stabilised its transformation of the phase from anatase to rutile, resulting in decreased particle size and enhancing its photocatalytic activity under UV irradiation. The concentration of OH• radicals was determined using terephthalic acid as a probe molecule to determine its role in the photocatalytic degradation of antihistamine. The results of BET analysis showed that the syn TiO2-SiO2 sample has a large specific surface area of 192.6 m2 g−1. Maximum degradation of cetirizine (about 97%) was achieved with 80% TiO2-20% SiO2 (TS-4). Recyclability test confirmed that 80% TiO2-20% SiO2 sample was stable up to six cycles.
Are hypertensive patients with history of coronary artery disease at risk for silent lower extremity artery disease?
Authors: Mulia Eka Prasetya Budi , Yuwono Kevin , Budiarto Raden Mohammad 
Published: September 2021

Abstract

Objectives
We aimed to investigate the association between hypertension and asymptomatic lower extremity artery disease (LEAD) in outpatients with known history of coronary artery disease (CAD).

Methods
Patients with known history of CAD who have been undergone coronary angiography and have significant coronary artery stenosis (more than 60%) were included. LEAD was defined as ankle-brachial index (ABI) < 0.9 in either leg. The risk of LEAD in hypertensive group was analyzed using chi-square test, and correlation between blood pressure (BP) and ABI was analyzed using Pearson correlation test in SPSS v.25.

Results
One hundred and four patients were included. 82.7% of patients were male. Mean age was 57.05 ± 7.97. The prevalence of hypertension was 35.6%, and the prevalence of LEAD was 16.3%. A higher proportion of LEAD was found in hypertensive (18.9%) compared to non-hypertensive (14.9%), although not statistically significant (OR: 1.33; 95% CI: 0.46 to 3.85; p=0.598). There was an association between ABI and systolic BP (p=0.016), but not with diastolic BP (p=0.102).

Conclusions
Our study showed that the prevalence of LEAD in hypertension, especially in the CAD population, is relatively high. There was no association between hypertension and LEAD, but a higher prevalence of LEAD was found in hypertensive patients. Nevertheless, LEAD screening is still recommended in hypertensive patients, especially in the CAD population, given the fact that outcomes of health and mortality are worse for those with concomitants of these diseases.
Anxiogenic and anxiolytic effects of memantine injected into the ventral hippocampus in male stressed mice
Authors: Sahraei Mohammad , Sahraei Hedayat , Rahimi Masoomeh , Khosravi Maryam , Ganjkhani Mahin , Meftahi Gholam Hossein 
Published: September 2021

Abstract

Objectives
The effects of intra-ventral hippocampal memantine administration in male NMRI stressed mice were studied.

Methods
Two stainless steel gauge 23 guide cannulas were placed in the middle part of the mice ventral hippocampus using stereotaxic coordination. Seven days later, the animals were undergone to the stress protocol as follows: They experience four consecutive electro-foot shock stress sessions lasting for 10 min. Five or 30 min before each stress session, the animals received intra-ventral hippocampal (0.1, 1 and, 5 µg/mouse) or intraperitoneal (1, 5, and 10 mg/kg) memantine respectively. Eight days after stress termination, the animals were tested either for the maintenance of either anxiety (elevated plus maze) or depression (forced swimming test).

Results
Animals show anxiety eight days after stress termination. Intra-ventral hippocampal infusion of memantine (5 µg/mouse) 5 min before stress inhibited the anxiety-like behaviors. However, other doses of the drug exacerbate the stress effect. The drug, when injected peripherally exacerbated the stress effect in all doses. The drug by itself had no effect. In addition, animals also show depression nine days after stress termination and memantine (0.1, 1, and 5 µg/mouse) reduced the stress effect. The drug (0.1 µg/mouse) by itself induced depression in the animals. However, the drug when injected peripherally reduced the stress effect in all doses.

Conclusions
It could be concluded that NMDA glutamate receptors in the ventral hippocampus may play a pivotal role in the mediation of maintenance of anxiety and depression induced by stress in the mice.
The influence of context on language alternation practices in English as a lingua franca
Authors: Pietikäinen Kaisa S. 
Published: September 2021

Abstract
This paper scrutinizes language alternation practices in different settings where English is predominantly used as the lingua franca (ELF). Data from different interactional contexts are examined: academic interactions from the ELFA corpus, doctoral defense discussions (also from the ELFA corpus), and informal family interactions. Corpus, discourse and conversation analytic methods and ethnographic information are used in analyzing these spoken data. I argue that translanguaging in lingua franca contexts is not only affected by speakers’ repertoire or the linguistic setting, but that there is a complex web of individual, interpersonal, group-related, and discourse environmental aspects which play their part in whether and to which extent speakers alternate languages in spoken ELF communication.