bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regularization and variable selection in Heckman selection model
Authors: Ogundimu Emmanuel O. 
Published: June 2021

AbstractSample selection arises when the outcome of interest is partially observed in a study. A common challenge is the requirement for exclusion restrictions. That is, some of the covariates affecting missingness mechanism do not affect the outcome. The drive to establish this requirement often leads to the inclusion of irrelevant variables in the model. A suboptimal solution is the use of classical variable selection criteria such as AIC and BIC, and traditional variable selection procedures such as stepwise selection. These methods are unstable when there is limited expert knowledge about the variables to include in the model. To address this, we propose the use of adaptive Lasso for variable selection and parameter estimation in both the selection and outcome submodels simultaneously in the absence of exclusion restrictions. By using the maximum likelihood estimator of the sample selection model, we constructed a loss function similar to the least squares regression problem up to a constant, and minimized its penalized version using an efficient algorithm. We show that the estimator, with proper choice of regularization parameter, is consistent and possesses the oracle properties. The method is compared to Lasso and adaptively weighted$$L_{1}$$L1penalized Two-step method. We applied the methods to the well-known Ambulatory Expenditure Data.
Acute disseminated encephalomyelitis with delayed onset and feasibility of the Miethke shunt and sensor reservoir system: a case report
Authors: Liminga Gunnar , Grabowska Anna , Pétursdóttir Dýrleif , Cesarini Kristina G. , Rostami Elham , Ehrstedt Christoffer 
Published: June 2021

AbstractAcute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating central nervous system disorder with predilection for early childhood. Delayed onset of ADEM is rare, and herein we present a previously healthy 5-year-old boy, with an unusual clinical course of ADEM with high intracranial pressure (ICP) and acute visual loss that was at first diagnosed as idiopathic intracranial hypertension without papilledema (IIHWOP). The boy underwent acute neurosurgical intervention with ventriculoperitoneal (VP) shunt using Miethke valve and sensor reservoir system and received high-dose steroid treatment with symptom relieve within days. This is the first case report using this system in such a young child, and we find it feasible and valuable also in younger children when VP shunt with ICP measurement is indicated.
Predictive factors for switching in patients with psoriatic arthritis undergoing anti-TNFα, anti-IL12/23, or anti-IL17 drugs: a 15-year monocentric real-life study
Authors: Lorenzin Mariagrazia , Ortolan Augusta , Cozzi Giacomo , Calligaro Antonia , Favaro Maria , Del Ross Teresa , Doria Andrea , Ramonda Roberta 
Published: June 2021

AbstractObjectivesWe aimed to evaluate the (a) potential predictors of first biological disease-modifying anti-rheumatic drug (bDMARD) failure and (b) factors associated with failure of multiple therapies in psoriatic arthritis (PsA).Materials and methodsWe enrolled consecutive PsA patients attending our unit and undergoing bDMARDs during 2004–2020. Disease characteristics, previous/ongoing treatments, comorbidities, and follow-up duration were recorded. Disease activity and functional and clinimetric scores were recorded at baseline and yearly and were compared between switchers and non-switchers, and within switchers according to the reasons for switching. Effectiveness was evaluated over time with descriptive statistics; multivariate Cox and logistic regression models were used to evaluate predictors of response and failure of multiple bDMARDs. Kaplan–Meier curves were used to assess differences in time-to-first bDMARD discontinuation. Infections and adverse events were recorded.ResultsTwo hundred sixty-four patients were included (117 (44.32%) females, mean age 56 years, mean PsA duration 15 years); 117 (44.32%) switched bDMARDs at least once. Switchers were mostly females, with higher Psoriasis Area and Severity Index and worse Health Assessment Questionnaire at baseline. Mean time-to-first bDMARD discontinuation was 72 months; 2-year and 5-year retention rates were 75% and 60%, respectively. Survival curves for anti-TNFα/anti-IL12/23/anti-IL17 were similar (p = 0.66). Main reasons for switching were inefficacy (67.52%) and adverse events (25.7%). Female sex was associated with a higher risk of first bDMARD discontinuation (HR = 2.39; 95% CI: 1.50–3.81) and failure of multiple bDMARDs (OR = 1.99; 95% CI: 1.07–3.69); initiating therapy before 2015 was protective (HR = 0.40; 95% CI: 0.22–0.73).ConclusionsSurvival rate was good for anti-TNFα and other bDMARDs. Female sex was a predictor of first bDMARD discontinuation, unlike mechanism of action, comorbidities, and BMI.Key Points• Drug survival in PsA patients was confirmed be greater for the first bDMARD administered.• In case of failure of the first bDMARD, switching/swapping proved a good treatment option, as reflected by a persistent satisfactory effectiveness with second-line bDMARDs and so subsequent switches.• Female sex may constitute a predisposing risk factor for flare and therapeutic switches.• Discontinuation or switching of biologics due to mechanism of action, comorbidities tolerability and BMI did not seem to impact first bDMARD withdrawal.
Mechanisms of passivation and chloride-induced corrosion of mild steel in sulfide-containing alkaline solutions
Authors: Mundra Shishir , Provis John L. 
Published: June 2021

AbstractThe pore fluid within many concretes is highly alkaline and rich in reduced sulfur species, but the influence of such alkaline-sulfide solutions on the surface film formed on steel reinforcement is poorly understood. This study investigates the critical role of HS− in defining mild steel passivation chemistry. The surface film formed on the steel in alkaline-sulfide solutions contains Fe(OH)2 and Fe–S complexes, and the critical chloride concentration to induce corrosion increases at high sulfide concentration. However, this behavior is dependent on the duration of exposure of the steel to the electrolyte, and the nature of the sulfidic surface layer.
Measuring service quality at an online university: using PLS-SEM with archival data
Authors: Schijns Jos M. C. 
Published: June 2021

AbstractThe aim of this study is to analyze, evaluate and validate the NSE (National Student Enquiry) as a service quality measure helping both higher education institutions (HEIs) and students in their decision making. Every year the Dutch foundation ‘Studiekeuze123’ sends out a survey (the NSE) to collect data on service quality regarding education at HEIs in the Netherlands. We used the 2019 NSE-data from the only e-learning university in the Netherlands, the Open Universiteit (OUNL), containing a sample of 1287 students. PLS-SEM was used to analyze a conceptual model in order to understand the service quality factors that promote students’ level of satisfaction and willingness to recommend the HEI. Overall, the findings reveal that the quality of the NSE is sufficient to be used for performance analysis. Nine out of twelve service components taken into account for the OUNL are found statistically significant affecting students’ satisfaction and willingness to recommend. The results help HEIs promoting and managing students’ perceptions of the quality of education and support students in their decision making process. Since many HEIs had to make a transition from onsite to online education within a short period of time, due to the Covid-19 pandemic, service quality became a major concern for HEIs. As online learning systems are expected to stay, analyzing the service quality of the OUNL as a reputed online HEI can help other HEIs getting their online learning systems on track.
Density Functional Theory Study into the Reaction Mechanism of Isonitrile Biosynthesis by the Nonheme Iron Enzyme ScoE
Authors: Ali Hafiz Saqib , Ghafoor Sidra , de Visser Sam P. 
Published: June 2021

AbstractThe nonheme iron enzyme ScoE catalyzes the biosynthesis of an isonitrile substituent in a peptide chain. To understand details of the reaction mechanism we created a large active site cluster model of 212 atoms that contains substrate, the active oxidant and the first- and second-coordination sphere of the protein and solvent. Several possible reaction mechanisms were tested and it is shown that isonitrile can only be formed through two consecutive catalytic cycles that both use one molecule of dioxygen and α-ketoglutarate. In both cycles the active species is an iron(IV)-oxo species that in the first reaction cycle reacts through two consecutive hydrogen atom abstraction steps: first from the N–H group and thereafter from the C–H group to desaturate the NH-CH2 bond. The alternative ordering of hydrogen atom abstraction steps was also tested but found to be higher in energy. Moreover, the electronic configurations along that pathway implicate an initial hydride transfer followed by proton transfer. We highlight an active site Lys residue that is shown to donate charge in the transition states and influences the relative barrier heights and bifurcation pathways. A second catalytic cycle of the reaction of iron(IV)-oxo with desaturated substrate starts with hydrogen atom abstraction followed by decarboxylation to give isonitrile directly. The catalytic cycle is completed with a proton transfer to iron(II)-hydroxo to generate the iron(II)-water resting state. The work is compared with experimental observation and previous computational studies on this system and put in a larger perspective of nonheme iron chemistry.
Deep Transfer Learning for Improved Detection of Keratoconus using Corneal Topographic Maps
Authors: Al-Timemy Ali H. , Ghaeb Nebras H. , Mosa Zahraa M. , Escudero Javier 
Published: June 2021

Abstract
Clinical keratoconus (KCN) detection is a challenging and time-consuming task. In the diagnosis process, ophthalmologists must revise demographic and clinical ophthalmic examinations. The latter include slit-lamb, corneal topographic maps, and Pentacam indices (PI). We propose an Ensemble of Deep Transfer Learning (EDTL) based on corneal topographic maps. We consider four pretrained networks, SqueezeNet (SqN), AlexNet (AN), ShuffleNet (SfN), and MobileNet-v2 (MN), and fine-tune them on a dataset of KCN and normal cases, each including four topographic maps. We also consider a PI classifier. Then, our EDTL method combines the output probabilities of each of the five classifiers to obtain a decision based on the fusion of probabilities. Individually, the classifier based on PI achieved 93.1% accuracy, whereas the deep classifiers reached classification accuracies over 90% only in isolated cases. Overall, the average accuracy of the deep networks over the four corneal maps ranged from 86% (SfN) to 89.9% (AN). The classifier ensemble increased the accuracy of the deep classifiers based on corneal maps to values ranging (92.2% to 93.1%) for SqN and (93.1% to 94.8%) for AN. Including in the ensemble-specific combinations of corneal maps’ classifiers and PI increased the accuracy to 98.3%. Moreover, visualization of first learner filters in the networks and Grad-CAMs confirmed that the networks had learned relevant clinical features. This study shows the potential of creating ensembles of deep classifiers fine-tuned with a transfer learning strategy as it resulted in an improved accuracy while showing learnable filters and Grad-CAMs that agree with clinical knowledge. This is a step further towards the potential clinical deployment of an improved computer-assisted diagnosis system for KCN detection to help ophthalmologists to confirm the clinical decision and to perform fast and accurate KCN treatment.
A Protection-Motivation Perspective to Explain Intention to Use and Continue to Use Mobile Warning Systems
Authors: Fischer-Preßler Diana , Bonaretti Dario , Fischbach Kai 
Published: June 2021

AbstractMobile emergency warning apps are essential for effective emergency communication – of course, provided the population intends to use them. Drawing on protection motivation theory, the study validated a psychometric model to explain what motivates individuals to install a warning app for the first time and to keep using it over time. Multi-group covariance-based structural equation modeling was used to model the answers to a survey that measured the drivers of intention to begin using or intention to continue using a warning app. The model shows that, for both non-users and users, trust, social influence, and response efficacy positively and maladaptive rewards negatively affect intention to use and intention to continue use warning apps. However, perceived vulnerability influences only intention to use, whereas response cost and self-efficacy affect continued use intention. Hence, this study enhances the theoretical understanding of technology-enabled protection behaviors and provides practitioners with a list of factors to consider for pushing the adoption and continued use of emergency warning applications.
Risk for Venous Thromboembolism in Transgender Patients Undergoing Cross-Sex Hormone Treatment: A Systematic Review
Authors: Kotamarti Vasanth S. , Greige Nicolas , Heiman Adee J. , Patel Ashit , Ricci Joseph A. 
Published: June 2021

ABSTRACTBackgroundFeminizing and masculinizing hormone treatments are established components of management in transgender patients. Exogenous hormones have been associated with hemostatic effects, which are well-studied in cis-gender individuals on hormone replacement therapy (HRT). Unfortunately, comprehensive understanding of their effects on venous thromboembolism (VTE) risk in the transgender population is lacking.AimThis manuscript aims to identify the risk of VTE among transgender individuals undergoing cross-sex hormone therapy.MethodsA Systematic review of the literature was performed in March 2020 for studies reporting VTE rates in transgender patients undergoing hormone treatment and rates in cis-gender patients on HRT. Data regarding demographics, hormone therapy, and VTE incidence were collected and pooled for analysis.OutcomeThe primary outcome of interest was the development of a VTE event in association with concurrent hormone administration.RESULTSOverall, 22 studies were included with 11 reporting VTE rates among transgender patients, 6 in cis-female patients, and 5 in cis-male patients. Data from 9,180 transgender patients (6,068 assigned male at birth [AMAB] and 3,112 assigned female at birth [AFAB]) undergoing hormone treatment and 103,713 cis-gender patients (18,748 female and 84,965 male) undergoing HRT were pooled. The incidence of VTE was higher in AMAB patients compared to AFAB patients (42.8 vs 10.8 VTE per 10,000 patient years; P = .02). The rate of VTE incidences in AMAB patients appears similar or higher than the rate demonstrated in cis-females on HRT. VTE incidence in AFAB patients, however, is similar to the published rates in cis-males on HRT.Clinical ImplicationsAMAB patients on hormone therapy have higher VTE rates than AFAB patients. AMAB and AFAB patients may have similar VTE incidence to cis-female and cis-male patients on hormone replacement therapy, respectively.Strengths & LimitationsThis is the first study to aggregate and quantify the development of VTE events in association with hormone therapy in transgender patients. It places these values in the context of rates published in more widely studied populations. It is limited by its retrospective data and heterogenic data.CONCLUSIONSurgical planning regarding perioperative and postoperative VTE prophylaxis or cessation of hormone therapy should take into account each patient’s Caprini risk assessment and the nature of each intervention.
Trends in racial and ethnic disparities in coronavirus disease 2019 (COVID-19) outcomes among nursing home residents
Authors: Li Yue , Cai Xueya , Mao Yunjiao , Cheng Zijing , Temkin-Greener Helena 
Published: June 2021

AbstractObjectives:To evaluate trends in racial and ethnic disparities in weekly cumulative rates of coronavirus disease 2019 (COVID-19) cases and deaths in Connecticut nursing homes.Design:Longitudinal analysis of nursing-home COVID-19 reports and other databases. Multivariable negative binomial models were used to estimate disparities in COVID-19 incidence and fatality rates across nursing-home groups with varying proportions of racial and ethnic minority residents, defined as low-, medium-, medium-high-, and high-proportion groups. Trends in such disparities were estimated from week 1 (April 13) to week 10 (ending on June 19, 2020).Setting:The study was conducted across 211 nursing homes.Results:The average number of cases ranged from 6.1 cases per facility for the low-proportion group to 11.7 cases per facility for the high-proportion group in week 1, and from 26.7 to 58.5 cases per facility in week 10. Compared to the low-proportion group, the adjusted incidence rate ratios (IRRs) for the high-proportion group were 1.18 (95% confidence interval [CI], 0.77–1.80; P > .10) in week 1 and 1.54 (95% CI, 1.05–2.25; P < .05) in week 10, showing a 30% (95% CI, 5%–62%) relative increase (P < .05). The average weekly number of COVID-19–related deaths ranged from 0 to 0.3 deaths per facility for different groups in week 1, and from 7.6 to 13.3 deaths per facility in week 10. Adjusted disparities in fatalities similarly increased over time.Conclusions:Connecticut nursing homes caring for predominately racial and ethnic minority residents tended to have higher COVID-19 incidence and fatality rates. These across-facility disparities increased during the early periods of the pandemic.
Olfactory response of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) to volatiles induced by transgenic maize
Authors: Nascimento P. T. , Fadini M. A. M. , Rocha M. S. , Souza C. S. F. , Barros B. A. , Melo J. O. F. , Von Pinho R. G. , Valicente F. H. 
Published: June 2021

AbstractPlants not only respond to herbivorous damage but adjust their defense system after egg deposition by pest insects. Thereby, parasitoids use oviposition-induced plant volatiles to locate their hosts. We investigated the olfactory behavioral responses of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to volatile blends emitted by maize (Zea mays L.) with singular and stacked events after oviposition by Spodoptera frugiperda Smith, 1797 (Hymenoptera: Trichogrammatidae) moths. Additionally, we examined possible variations in gene expression and on oviposition-induced volatiles. We used a Y-tube olfactometer to test for the wasp responses to volatiles released by maize plants oviposited by S. frugiperda and not-oviposited plants. Using the real-time PCR technique (qRT-PCR), we analyzed the expression of lipoxygenase and three terpene synthases genes, which are enzymes involved in the synthesis of volatile compounds that attract parasitoids of S. frugiperda. Olfactometer tests showed that T. pretiosum is strongly attracted by volatiles from transgenic maize emitted by S. frugiperda oviposition (VTPRO 3, more than 75% individuals were attracted). The relative expression of genes TPS10, LOX e STC was higher in transgenic hybrids than in the conventional (isogenic line) hybrids. The GC-MS analysis revealed that some volatile compounds are released exclusively by transgenic maize. This study provides evidence that transgenic hybrids enhanced chemical cues under oviposition-induction and helped to increase T. pretiosum efficiency in S. frugiperda control. This finding shows that among the evaluated hybrids, genetically modified hybrids can improve the biological control programs, since they potentialize the egg parasitoid foraging, integrating pest management.
The effect of laryngeal elevation training on swallowing function in patients with dysphagia
Authors: Sugaya N , Goto F , Seino Y , Nishiyama K , Okami K 
Published: June 2021

AbstractObjectiveTo investigate the effect of laryngeal elevation training without highly loaded head lifting on swallowing function in patients with dysphagia.MethodsFifty-seven patients with dysphagia (36 men; mean age, 78.5 ± 11.4 years) were included. All participants performed the swallowing forehead exercise and the chin push–pull manoeuvre for two months. Videoendoscopy to assess swallowing function, the peak expiratory flow test and the hand grip strength test were performed at the initial visit (time 1) and two months after the start of the intervention (time 2). We used the Hyodo score, a scoring method for videoendoscopic assessment, for evaluation of swallowing function.ResultsThe linear mixed model showed a significant main effect of time (the Hyodo score at time 1 was greater than the score at time 2). The effects of the co-variates were not significant.ConclusionThe present study demonstrated the significant effect of laryngeal elevation training without head lifting on the Hyodo score.
Turning Over a New Leaf: A Subnational Analysis of ‘Coca Yes, Cocaine No’ in Bolivia
Authors: Brewer-Osorio Susan 
Published: June 2021

AbstractInternational pressure to suppress cocaine trafficking sustained decades of harsh drug laws in Bolivia against cocaleros (coca producers), thus affecting coca production for traditional consumption and for manufacturing illicit cocaine. These harsh drug laws caused social unrest in cocalero communities outside traditional coca zones. President Evo Morales, leader of the Movimiento al Socialismo (Movement toward Socialism, MAS) party, implemented ‘Coca Yes, Cocaine No’ (CYCN), a harm-reduction strategy that authorised ‘non-traditional’ farmers to cultivate legal coca and self-police production. This article compares CYCN outcomes in Bolivia's traditional and non-traditional coca regions and finds that strong cocalero organisations were vital to CYCN success in non-traditional areas. In contrast, organised resistance in traditional zones restricted CYCN success and added to regime instability in the lead-up to Morales’ forced resignation in 2019. Hence, while Morales harnessed state power to change drug policy, he was constrained by the rural grassroots organisations that brought him to power.
Collision-Free Motion Planning for an Aligned Multiple-turret System Operating in Extreme Environment
Authors: Yerlikaya Ümit , Balkan R.Tuna 
Published: June 2021

AbstractInstead of using the tedious process of manual positioning, an off-line path planning algorithm has been developed for military turrets to improve their accuracy and efficiency. In the scope of this research, an algorithm is proposed to search a path in three different types of configuration spaces which are rectangular-, circular-, and torus-shaped by providing three converging options named as fast, medium, and optimum depending on the application. With the help of the proposed algorithm, 4-dimensional (D) path planning problem was realized as 2-D + 2-D by using six sequences and their options. The results obtained were simulated and no collision was observed between any bodies in these three options.