bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitive and Low‐background Electrochemical Immunosensor Employing Glucose Dehydrogenase and 1,10‐Phenanthroline‐5,6‐dione
Authors: Jiaul Haque Al‐Monsur , Kwon Jungwook , Kim Jihyeon , Kim Gyeongho , Lee Nam‐Sihk , Ho Yoon Young , Yang Haesik 
Published: May 2021

AbstractWe report a sensitive electrochemical immunosensor with a low electrochemical background level, which results from electrochemical‐enzymatic (EN) redox cycling based on mediated electrochemical oxidation of an electro‐inactive reductant (glucose) at 0.0 V. The EN redox cycling employs flavin adenine dinucleotide‐dependent glucose dehydrogenase and 1,10‐phenanthroline‐5,6‐dione (PD). When PD was compared with five common quinone‐based electron mediators, PD enabled the highest signal‐to‐background ratio, due to a very low electrochemical background level. When EN redox cycling was applied to a sandwich‐type immunosensor, parathyroid hormone (PTH) in serum could be detected with a very low detection limit of ∼0.1 pg/mL.
Native and substituted cyclodextrins as chiral selectors for capillary electrophoresis enantioseparations: Structures, features, application, and molecular modeling
Authors: Peluso Paola , Chankvetadze Bezhan 
Published: May 2021

AbstractCDs are cyclic oligosaccharides consisting of α‐d‐glucopyranosyl units linked through 1,4‐linkages, which are obtained from enzymatic degradation of starch. The coexistence of hydrophilic and hydrophobic regions in the same structure makes these macrocycles extremely versatile as complexing host with application in food, cosmetics, environmental, agriculture, textile, pharmaceutical, and chemical industries. Due to their inherent chirality, CDs have been also successfully used as chiral selectors in enantioseparation science, in particular, for CE enantioseparations. In the last decades, multidisciplinary approaches based on CE, NMR spectroscopy, X‐ray crystallography, microcalorimetry, and molecular modeling have shed light on some aspects of recognition mechanisms underlying enantiodiscrimination. With the ever growing improvement of computer facilities, hardware and software, computational techniques have become a useful tool to model at molecular level the dynamics of diastereomeric associate formation to sample low‐energy conformations, the binding energies between the enantiomer and the CD, and to profile noncovalent interactions contributing to the stability of CD/enantiomer association. On this basis, the aim of this review is to provide the reader with a critical overview on the applications of CDs in CE. In particular, the contemporary theory of the electrophoretic technique and the main structural features of CDs are described, with a specific focus on techniques, methods, and approaches to model CE enantioseparations promoted by native and substituted CDs. A systematic compilation of all published literature has not been attempted.
Production of biolubricant samples from palm kernel oil using different chemical modification approaches
Authors: Egbuna Samuel O. , Nwachukwu Ukeh J. , Agu Chinedu M. , Asadu Christain O. , Okolo Bernard 
Published: May 2021

AbstractThis work focused on the chemical synthesis and characterization of palm kernel oil (PKO) for biolubricant production using transesterification of palm kernel methyl ester with trimethylolpropane (TMP) and epoxidation‐esterification methods. The PKO was extracted using solvent extraction method. The physicochemical characteristics of the PKO and produced biolubricant samples were determined using standard methods. Fourier transform infrared (FTIR) spectrometry and gas chromatographic (GC) analyses were used to determine the predominant functional groups and fatty acids of PKO and the produced biolubricant samples, respectively. The kernel oil yield of 49.82% (by weight) was obtained at 55°C, 150 min and 0.5 mm particle size. The viscosities at 40°C, 100°C, viscosity index, pour and flash points of the biolubricants produced by transesterification with TMP (PKBLT) and epoxidation‐esterification (PKBLE) methods, were (42.53 cSt, 10.65 cSt, 139, −11°C, 235°C) and (44.69 cSt, 11.42 cSt, 132, −12°C, 240°C), respectively. Time, mole ratio, and temperature effects were the main factors that significantly influenced the transesterification and epoxidation processes. The obtained physicochemical properties of PKBLE and PKBLT samples showed conformity with ISO VG 32 standard, hence their possible application as biolubricant basestock. Furthermore, the presences of the C–H, OH functional groups in the FTIR results, indicate the biodegradability of the produced biolubricant samples; while the GC analyses indicate that the samples were mainly saturated fatty acids.
Spatiotemporal clustering using Gaussian processes embedded in a mixture model
Authors: Vanhatalo Jarno , Foster Scott D. , Hosack Geoffrey R. 
Published: May 2021

AbstractThe categorization of multidimensional data into clusters is a common task in statistics. Many applications of clustering, including the majority of tasks in ecology, use data that is inherently spatial and is often also temporal. However, spatiotemporal dependence is typically ignored when clustering multivariate data. We present a finite mixture model for spatial and spatiotemporal clustering that incorporates spatial and spatiotemporal autocorrelation by including appropriate Gaussian processes (GP) into a model for the mixing proportions. We also allow for flexible and semiparametric dependence on environmental covariates, once again using GPs. We propose to use Bayesian inference through three tiers of approximate methods: a Laplace approximation that allows efficient analysis of large datasets, and both partial and full Markov chain Monte Carlo (MCMC) approaches that improve accuracy at the cost of increased computational time. Comparison of the methods shows that the Laplace approximation is a useful alternative to the MCMC methods. A decadal analysis of 253 species of teleost fish from 854 samples collected along the biodiverse northwestern continental shelf of Australia between 1986 and 1997 shows the added clarity provided by accounting for spatial autocorrelation. For these data, the temporal dependence is comparatively small, which is an important finding given the changing human pressures over this time.
Dynamic malware attack dataset leveraging virtual machine monitor audit data for the detection of intrusions in cloud
Authors: Melvin A. Alfred Raja , Kathrine G. Jaspher W. , Ilango S. Sudhakar , Vimal S. , Rho Seungmin , Xiong Neal N. , Nam Yunyoung 
Published: May 2021

AbstractIn this new era of cloud computing, Intrusion Detection System (IDS) is very essential for the continual monitoring of computing resources for signs of compromise since the number of attack vectors and malware are in increase. Only few IDS datasets are publicly available and those available are outdated, lack cloud‐specific attacks. This article presents a novel dataset based on Virtual Machine Introspected data for the implementation of IDS in cloud. The dataset was generated from the behavioral characteristics of malware and benign sample execution traces on virtual machines using Virtual Machine Introspection (VMI) technique. A vector space model based on system call approach is applied to analyze the behavioral characteristics for the generation of proposed dataset. The purpose of this study is to compare the proposed dataset with existing datasets and evaluate the effectiveness of these datasets by applying Machine Learning (ML) algorithms with 10‐fold cross‐validation. The ML algorithms used in the experiments are C4.5, Random Forest, JRip, NaiveBayes, K‐Nearest Neighbors (KNN), and Support Vector Machine (SVM). The effectiveness of detecting intrusions using proposed dataset is promising compared with other datasets in‐terms of intrusion detection accuracy, recall value, precision, and F1‐score metrics. For example, the intrusion detection accuracy in proposed dataset is 0.11% improved than UNM dataset, 6.28% higher than ADFA dataset, and 1.88% higher than LID dataset with C4.5 algorithm. Therefore, the proposed dataset is best suitable for implementing IDS for cloud.
Effects of structural changes on the prediction of downside volatility in futures markets
Authors: Gong Xu , Lin Boqiang 
Published: May 2021

AbstractWe develop a heterogeneous autoregressive model of downside volatility (HAR‐DV) model with structural changes (HAR‐DV‐SC) model to investigate the effects of structural changes on predicting downside volatility. Then we employ HAR‐DV and HAR‐DV‐SC models to forecast downside volatilities in S&P 500 index, crude oil, gold, copper, and soybean futures markets. The in‐sample analysis shows that structural changes contain in‐sample information for predicting downside volatility. The out‐of‐sample analysis indicates that the HAR‐DV‐SC model outperforms the HAR‐DV model, suggesting that structural changes contain incremental out‐of‐sample information on future downside volatility. These results are robust and have important implications for risk management of stakeholders.
Portfolio of Volatility Smiles versus Volatility Surface: Implications for pricing and hedging options
Authors: Kim Sol 
Published: May 2021

AbstractIn this study, we compare the pricing and hedging performance of options‐pricing models using two parameter‐estimation methods to employ cross‐sectional options data with multiple maturities. In the Portfolio of Volatility Smiles method, each set of parameters that describe the individual volatility smile for each maturity is estimated separately. In the Volatility Surface method, a single‐parameter set that describes the entire volatility surface is estimated, regardless of the time‐to‐maturity. When pricing and hedging options with various times to maturity, the Portfolio of Volatility Smiles method generally outperforms the Volatility Surface method, irrespective of the option‐pricing model used, maturity, and moneyness. Considering the volatility smile individually at each maturity is more effective in pricing and hedging options than is considering the volatility surface simultaneously.
The Spatiotemporal Dynamics of Land Use Land Cover Change, and Its Impact on Soil Erosion in Tagaw Watershed, Blue Nile Basin, Ethiopia
Authors: Melese Tadele , Senamaw Abebe , Belay Tatek , Bayable Getachew 
Published: May 2021

AbstractThe Blue Nile basin is one of the hot‐spots of soil erosion areas in Ethiopia. However, the impact of land use changes on soil erosion is poorly understood in the Tagaw watershed. Hence, the objective of the study is to assess the impact of land use changes on soil erosion in Tagaw watershed over the last 31 years. Rainfall, soil, satellite images and topographic data are acquired from field survey and secondary sources. A Revised Universal Soil Loss Equation (RUSLE) model is used to estimate soil erosion. The mean annual and total potential soil losses of the watershed are 19.3, 22.9, 26 and 0.06–503.56, 0.11–516.67, and 0.00–543.5 tons ha−1 yr−1 for 1995, 2006 and 2016 respectively. The highest soil loss is found for bare land. The RUSLE model further showed that the highest soil erosion occurred in 2016 whereas the lowest soil erosion occurred in 1995.
The COVID‐19 Menace
Authors: Walczak Piotr , Janowski Miroslaw 
Published: May 2021

AbstractCoronavirus disease 2019 (COVID‐19) is caused by the new severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which binds to ectoenzyme angiotensin‐converting enzyme 2. It is very contagious and is spreading rapidly around the world. Until now, coronaviruses have mainly been associated with the aerodigestive tract due to the presence of a monobasic cleavage site for the resident transmembrane serine protease 2. Notably, SARS‐CoV‐2 is equipped with a second, polybasic cleavage site for the ubiquitous furin protease, which may determine the widespread tissue tropism. Furthermore, the terminal sequence of the furin‐cleaved spike protein also binds to neuropilin receptors. Clinically, there is enormous variability in the severity of the disease. Severe consequences are seen in a relatively small number of patients, most show moderate symptoms, but asymptomatic cases, especially among young people, drive disease spread. Unfortunately, the number of local infections can quickly build up, causing disease outbreaks suddenly exhausting health services’ capacity. Therefore, COVID‐19 is dangerous and unpredictable and has become the most serious threat for generations. Here, the latest research on COVID‐19 is summarized, including its spread, testing methods, organ‐specific complications, the role of comorbidities, long‐term consequences, mortality, as well as a new hope for immunity, drugs, and vaccines.
Carbonates from the ancient world's longest aqueduct: A testament of Byzantine water management
Authors: Sürmelihindi Gül , Passchier Cees , Crow James , Spötl Christoph , Mertz‐Kraus Regina 
Published: May 2021

AbstractThe fourth‐ and fifth‐century aqueduct system of Constantinople is, at 426 km, the longest water supply line of the ancient world. Carbonate deposits i659ide an archive of both archaeological developments and palaeo‐environmental conditions during the depositional period. The 246‐km‐long aqueduct line from the fourth century used springs from a small aquifer, whereas a 180‐km‐long fifth‐century extension to the west tapped a larger aquifer. Although historical records testify at least 700 years of aqueduct activity, carbonate deposits in the aqueduct system display less than 27 years of operation. This implies that the entire system must have been cleaned of carbonate, presumably during regular campaigns. A 50‐km‐long double‐aqueduct section in the central part of the system may have been a costly but practical solution to allow repairs and cleaning of the aqueducts of carbonate to ascertain a continuous water supply to the city. The fifth‐century channel was commonly contaminated with clay, caused by the nature of the aqueduct system and possible local damage to the channel. This clay‐rich water could have been one of the reasons for the construction of large reservoirs in Constantinople.image
Oligodendrocyte progenitor cell maturation is dependent on dual function of MCT8 in the transport of thyroid hormone across brain barriers and the plasma membrane
Authors: Vatine Gad D. , Shelest Oksana , Barriga Bianca K. , Ofan Raz , Rabinski Tatyana , Mattis Virginia B. , Heuer Heike , Svendsen Clive N. 
Published: May 2021

AbstractInactivating mutations in the thyroid hormone (TH) transporter monocarboxylate transporter 8 (MCT8) causes a rare and debilitating form of X‐linked psychomotor disability known as Allan Herndon Dudley syndrome (AHDS). One of the most prominent pathophysiological symptoms of MCT8‐deficiency is hypomyelination. Here, patient‐derived induced pluripotent stem cells (iPSCs) were used to study the role of MCT8 and TH on the maturation of oligodendrocytes. Interestingly, neither MCT8 mutations nor reduced TH affected the in vitro differentiation of control or MCT8‐deficient iPSCs into oligodendrocytes. To assess whether patient‐derived iPSC‐derived oligodendrocyte progenitor cells (iOPCs) could provide myelinating oligodendrocytes in vivo, cells were transplanted into the shiverer mouse corpus callosum where they survived, migrated, and matured into myelinating oligodendrocytes, though the myelination efficiency was reduced compared with control cells. When MCT8‐deficient and healthy control iOPCs were transplanted into a novel hypothyroid immunodeficient triple knockout mouse (tKO, mct8−/−; oatp1c1−/−; rag2−/−), they failed to provide behavioral recovery and did not mature into oligodendrocytes in the hypothyroid corpus callosum, demonstrating the critical role of TH transport across brain barriers in oligodendrocyte maturation. We conclude that MCT8 plays a cell autonomous role in oligodendrocyte maturation and that functional TH transport into the central nervous system will be required for developing an effective treatment for MCT8‐deficient patients.
Network interdigitations of Tau and amyloid‐beta deposits define cognitive levels in aging
Authors: Kim Chan‐Mi , Montal Victor , Diez Ibai , Orwig William ,   Alzheimer's Disease Neuroimaging Initiative (ADNI), Sepulcre Jorge 
Published: May 2021

AbstractAmyloid‐beta (Aβ) plaques and tau neurofibrillary tangles are pathological hallmarks of Alzheimer's disease (AD); their contribution to neurodegeneration and clinical manifestations are critical in understanding preclinical AD. At present, the mechanisms related to Aβ and tau pathogenesis leading to cognitive decline in older adults remain largely unknown. Here, we examined graph theory‐based positron emission tomography (PET) analytical approaches, within and between tau and Aβ PET modalities, and tested the effects on cognitive changes in cognitively normal older adults (CN). Particularly, we focused on the network interdigitations of Aβ and tau deposits, along with cognitive test scores in CN at both baseline and 2‐year follow‐up (FU). We found highly significant Aβ‐tau network integrations in AD vulnerable areas, as well as significant associations between those Aβ‐tau interdigitations and general cognitive impairment in CN at baseline and FU. Our findings suggest a distinctive contribution of interlinking network relationships between Aβ and tau deposits in heteromodal areas of the human brain. They support a network‐based interaction between Aβ and tau accumulations as a key factor for cognitive deterioration in CN prior to dementia.
Distributed functional connectivity predicts neuropsychological test performance among older adults
Authors: Kwak Seyul , Kim Hairin , Kim Hoyoung , Youm Yoosik , Chey Jeanyung 
Published: May 2021

AbstractNeuropsychological test is an essential tool in assessing cognitive and functional changes associated with late‐life neurocognitive disorders. Despite the utility of the neuropsychological test, the brain‐wide neural basis of the test performance remains unclear. Using the predictive modeling approach, we aimed to identify the optimal combination of functional connectivities that predicts neuropsychological test scores of novel individuals. Resting‐state functional connectivity and neuropsychological tests included in the OASIS‐3 dataset (n = 428) were used to train the predictive models, and the identified models were iteratively applied to the holdout internal test set (n = 216) and external test set (KSHAP, n = 151). We found that the connectivity‐based predicted score tracked the actual behavioral test scores (r = 0.08–0.44). The predictive models utilizing most of the connectivity features showed better accuracy than those composed of focal connectivity features, suggesting that its neural basis is largely distributed across multiple brain systems. The discriminant and clinical validity of the predictive models were further assessed. Our results suggest that late‐life neuropsychological test performance can be formally characterized with distributed connectome‐based predictive models, and further translational evidence is needed when developing theoretically valid and clinically incremental predictive models.
Place of birth for unintended pregnancies in six former Soviet Union countries
Authors: Bellizzi Saverio , Pichierri Giuseppe , Panu Napodano Catello M , Murgia Paola , Padrini Susanna , Bassat Quique 
Published: May 2021

AbstractObjectiveThis paper aims at exploring the association between unintended pregnancies and place of birth in six Former Soviet Union (FSU) countries.Material and methodsA secondary analysis of the latest cross‐sectional Demographic and Health Surveys of six FSU countries from 2005 through 2012 was conducted. Prevalence of institutional births and unintended pregnancies was estimated by country and for the pooled population. Odds ratio (OR) and 95% confidence interval (CI) were calculated to measure the country and pooled association between pregnancy intention and institutional birth.ResultsInstitutional births occurred in 90.4% of the overall study population and ranged from 78.2% in Tajikistan to 99.7% in Ukraine Demographic and Health Survey. Around one out of 10 pregnancies resulted unintended. In the pooled analysis, unintended pregnancies were significantly associated with giving births outside health facility (aOR1.2; 95% CI 1.0–1.6).ConclusionBased on the study findings we suggest that increase awareness of benefit of skilled delivery care is needed among women with poor access to family planning.
Hair today, gone tomorrow: How personal protective equipment guidance changed doctor's facial hair during the COVID‐19 pandemic
Authors: Sahota Sanjeev , Gill Simon , Ridenton Jennifer , Hegarty Helen , Pope Katherine , Gentile Giorgio 
Published: May 2021

AbstractObjectivesTo investigate how personal protective equipment (PPE) guidance altered the facial hair of hospital doctors and explore the wider impact and implications of these changes.MethodsA single site uncontrolled before‐after survey study examining change in facial hairstyles, and wider implications on doctor's cultural, religious, and personal wellbeing. Outcome measures included change in facial hair between January and April 2020 and whether these changes adhered to guidance set by Public Health England. Participants were also asked about the wider impact of these changes which were thematically analyzed using an inductive approach.ResultsOf those who completed the survey, 257 participants met the inclusion criteria. 68% (n = 67) of doctors who could grow facial hair changed their facial hairstyle during the COVID‐19 pandemic and 96% (n = 64) reported that the change was in response to PPE guidance. The odds of having a facial hairstyle that complied with PPE guidance before the pandemic was 0.32, which rose to 2.77 after guidance was released, giving an odds ratio of 8.54 (95% CI 4.49‐16.23, P < .001). When compared to those who sported a shaven face prepandemic, the odds ratio of a change in style for those with prepandemic full beards was 37.92 (95% CI 7.45‐192.8, P < .001), for goatees was 7.22 (95% CI 1.076‐48.47, P = .04), for moustaches was 4.33 (95% CI 0.207‐90.85, P = .345), and for stubble was 9.06 (95% CI 2.133‐38.49, P = .003). Qualitative analysis revealed multiple themes, including skin irritation, loss of identity, and a significant impact on participants required to maintain a beard due to religious or cultural reasons.ConclusionsFacial hairstyles have changed significantly at our hospital during the COVID‐19 pandemic. Facial hair can impact upon doctors' cultural, religious, and personal wellbeing and these factors need to be considered with policy and provision of PPE.