bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sentiment analysis on massive open online course evaluations: A text mining and deep learning approach
Authors: ONAN Aytuğ 
Published: May 2020

AbstractMassive open online courses (MOOCs) are recent innovative approaches in distance education, which provide learning content to participants without age‐, gender‐, race‐, or geography‐related barriers. The purpose of our research is to present an efficient sentiment classification scheme with high predictive performance in MOOC reviews, by pursuing the paradigms of ensemble learning and deep learning. In this contribution, we seek to answer several research questions on sentiment analysis on educational data. First, the predictive performance of conventional supervised learning methods, ensemble learning methods and deep learning methods has been evaluated. Besides, the efficiency of text representation schemes and word‐embedding schemes has been evaluated for sentiment analysis on MOOC evaluations. For the evaluation task, we have analyzed a corpus containing 66,000 MOOC reviews, with the use of machine learning, ensemble learning, and deep learning methods. The empirical analysis indicate that deep learning‐based architectures outperform ensemble learning methods and supervised learning methods for the task of sentiment analysis on educational data mining. For all the compared configurations, the highest predictive performance has been achieved by long short‐term memory networks in conjunction with GloVe word‐embedding scheme‐based representation, with a classification accuracy of 95.80%.
Robotic‐assisted balloon angioplasty and stent placement with distal embolic protection device for severe carotid artery stenosis in a high‐risk surgical patient
Authors: George Jon C. , Tabaza Luai , Janzer Sean 
Published: May 2020

AbstractThe use of robotic assistance in endovascular interventions may facilitate smoother procedures with fewer device manipulations, improve precision and accuracy of device deployment, and reduce exposure to fluoroscopic radiation. We used the CorPath GRX Robotic System for carotid balloon angioplasty and stent placement in a patient with limited surgical options.
Impact of coronavirus disease 2019 (COVID‐19) outbreak on outcome of myocardial infarction in Hong Kong, China
Authors: Tam Chor‐Cheung Frankie , Cheung Kent‐Shek , Lam Simon , Wong Anthony , Yung Arthur , Sze Michael , Fang Jonathan , Tse Hung‐Fat , Siu Chung‐Wah 
Published: May 2020

AbstractObjectiveTo determine whether COVID‐19 may adversely affect outcome of myocardial infarction (MI) patients in Hong Kong, China.BackgroundThe COVID‐19 pandemic has infected thousands of people and placed enormous stress on healthcare system. Apart from being an infectious disease, it may affect human behavior and healthcare resource allocation which potentially cause treatment delay in MI.MethodsThis was a single center cross‐sectional observational study. From November 1, 2019 to March 31, 2020, we compared outcome of patients admitted for acute ST‐elevation MI (STEMI) and non‐ST elevation MI (NSTEMI) before (group 1) and after (group 2) January 25, 2020 which was the date when Hong Kong hospitals launched emergency response measures to combat COVID‐19.ResultsThere was a reduction in daily emergency room attendance since January 25, 2020 (group 1,327/day vs. group 2,231/day) and 149 patients with diagnosis of MI were included into analysis (group 1 N = 85 vs. group 2 N = 64). For STEMI, patients in group 2 tended to have longer symptom‐to‐first medical contact time and more presented out of revascularization window (group 1 27.8 vs. group 2 33%). The primary composite outcome of in‐hospital death, cardiogenic shock, sustained ventricular tachycardia or fibrillation (VT/VF) and use of mechanical circulatory support (MCS) was significantly worse in group 2 (14.1 vs. 29.7%, p = .02).ConclusionsMore MI patients during COVID‐19 outbreak had complicated in‐hospital course and worse outcomes. Besides direct infectious complications, cardiology community has to acknowledge the indirect effect of communicable disease on our patients and system of care.
How Lanthanide Ions Affect the Addition–Elimination Step of Methanol Dehydrogenases
Authors: Prejanò Mario , Russo Nino , Marino Tiziana 
Published: May 2020

AbstractThe recently discovered methanol dehydrogenase, XoxF, is a widespread enzyme used by methylotrophic bacteria to oxidize methanol for carbon and energy, and requires lanthanide ions for its activity. This enzyme represents an essential component of methanol utilization by both methanol‐ and methane‐utilizing bacteria. The present investigation looks on the electronic, energetic and geometrical behavior of the methanol dehydrogenase from Methylacidiphilum fumariolicum SolV, which is strictly dependent on early lanthanide metals with +3 oxidation states, by examining enzyme‐substrate complexes of all the lanthanides. We focus on the catalytic reaction mechanism of two methanol dehydrogenases having as cofactor europium and ytterbium belonging to the mid‐ and later‐ series of lanthanides, in comparison with the methanol dehydrogenase containing the cerium, one early lanthanide. Our results provide evidence for the influence of the lanthanide contraction effect in all the elementary steps of the catalytic reaction mechanism. This indication may prove useful for developing new catalytic machineries of enzymes that adopt new‐to‐nature transformations.
Regioselective 3‐O‐Substitution of Unprotected Thiodigalactosides: Direct Route to Galectin Inhibitors
Authors: Vašíček Tomáš , Spiwok Vojtěch , Červený Jakub , Petrásková Lucie , Bumba Ladislav , Vrbata David , Pelantová Helena , Křen Vladimír , Bojarová Pavla 
Published: May 2020

AbstractThe synthesis of tailored bioactive carbohydrates usually comprises challenging (de)protection steps, which lowers synthetic yields and increases time demands. We present here a regioselective single‐step introduction of benzylic substituents at 3‐hydroxy groups of β‐d‐galactopyranosyl‐(1→1)‐thio‐β‐d‐galactopyranoside (TDG) employing dibutyltin oxide in good yields. These glycomimetics act as inhibitors of galectins—human lectins, which are biomedically attractive targets for therapeutic inhibition in, for example, cancerogenesis. The affinity of the prepared glycomimetics to galectin‐1 and galectin‐3 was studied in enzyme‐linked immunosorbent (ELISA)‐type assays and their potential to inhibit galectin binding on the cell surface was shown. We used our original in vivo biotinylated galectin constructs for easy detection by flow cytometry. The results of the biological experiments were compared with data from molecular modeling with both galectins. The present work reveals a facile and elegant synthetic route for the preparation of TDG‐derived glycomimetics that exhibit differing selectivity and affinity to galectins depending on the choice of 3‐O‐substitution.
Controllable Skeleton Rearrangement of 3‐Substituted Cyclobutanones under Basic Conditions†
Authors: Yan Peng , Zhou Qiang , Chen Jun , Lu Ping 
Published: May 2020

Summary of main observation and conclusionDivergent skeleton rearrangements of cyclobutanones under simply basic conditions have been described. The reaction pathway is controlled by the nature of Z group on 3‐substituted cyclobutanones, leading to the formation of various lactones, lactams and acids. Preliminary results on enantioselective reaction were also reported.
Projections between visual cortex and pulvinar in the rat
Authors: Scholl Leo R. , Foik Andrzej T. , Lyon David C. 
Published: May 2020

AbstractThe extrageniculate visual pathway, which carries visual information from the retina through the superficial layers of the superior colliculus and the pulvinar, is poorly understood. The pulvinar is thought to modulate information flow between cortical areas, and has been implicated in cognitive tasks like directing visually guided actions. In order to better understand the underlying circuitry, we performed retrograde injections of modified rabies virus in the visual cortex and pulvinar of the Long‐Evans rat. We found a relatively small population of cells projecting to primary visual cortex (V1), compared to a much larger population projecting to higher visual cortex. Reciprocal corticothalamic projections showed a similar result, implying that pulvinar does not play as big a role in directly modulating rodent V1 activity as previously thought.
Perceptual rivalry across animal species
Authors: Carter Olivia , van Swinderen Bruno , Leopold David A. , Collin Shaun P. , Maier Alexander 
Published: May 2020

AbstractThis review in memoriam of Jack Pettigrew provides an overview of past and current research into the phenomenon of multistable perception across multiple animal species. Multistable perception is characterized by two or more perceptual interpretations spontaneously alternating, or rivaling, when animals are exposed to stimuli with inherent sensory ambiguity. There is a wide array of ambiguous stimuli across sensory modalities, ranging from the configural changes observed in simple line drawings, such as the famous Necker cube, to the alternating perception of entire visual scenes that can be instigated by interocular conflict. The latter phenomenon, called binocular rivalry, in particular caught the attention of the late Jack Pettigrew, who combined his interest in the neuronal basis of perception with a unique comparative biological approach that considered ambiguous sensation as a fundamental problem of sensory systems that has shaped the brain throughout evolution. Here, we examine the research findings on visual perceptual alternation and suppression in a wide variety of species including insects, fish, reptiles, and primates. We highlight several interesting commonalities across species and behavioral indicators of perceptual alternation. In addition, we show how the comparative approach provides new avenues for understanding how the brain suppresses opposing sensory signals and generates alternations in perceptual dominance.
Transportable Mononuclear Metal Atoms as Building Blocks for Bottom‐up Material Fabrication: Pt1(0) and Au1(0) Atoms in Stock Solutions
Authors: Li Huixiang , Liang Changhui , Gao Pan , Hou Guangjin , Liu Kairui , Liu Wei , Jiang Qike , Bai Shi , Zhang Z. Conrad 
Published: May 2020

AbstractPremade and readily transportable mononuclear zero‐valent metal atoms in stock solvents offer the potential capability for bottom‐up designable metallic material fabrication. This work demonstrates a potentially universal and practical strategy to prepare weakly shielded mononuclear metal atoms in a volatile solvent, which also constitutes a strippable ligand to the metal atoms. Herein, M1(0) (M=Pt, Au) atoms are prepared by reducing H2PtCl6 and HAuCl4 with ethanol in ethylene glycol diethyl ether (EGDE) under mild temperatures. The diether oxygens of EGDE, H+, and Cl− coordinating to the M1(0) atoms, make the M1(0) atoms stable in the solvent under low pH. However, the M1(0) atoms can be released either by evaporation of HCl and EGDE or through neutralization of the HCl with a base. The premade M1(0) atoms can be used as primary building blocks to construct designable materials. To demonstrate a potential application, the M1(0) atoms are conveniently transported onto the surface of TiO2 through impregnation followed by mild heating. The atomic dispersion and reduced state of the metal atoms are well preserved, as verified by HAADF‐STEM images, XPS, and DRIFT spectroscopy.
Recent Advances in Activatable Organic Photosensitizers for Specific Photodynamic Therapy
Authors: Liu Ming , Li Changhua 
Published: May 2020

AbstractPhotodynamic therapy is an alternative modality for the therapy of diseases such as cancer in a minimally invasive manner. The essential photosensitizer, which acts as a catalyst when absorbing light, converts oxygen into cytotoxic reactive oxygen species that ablate malignant cells through apoptosis and/or necrosis, destroy tumor microvasculature, and stimulate immunity. An activatable photosensitizer whose photoactivity could be turned on by a specific disease biomarker is capable of distinguishing healthy cells from diseased cells, thereby reducing off‐target photodamage. In this Minireview, we highlight progress in activatable organic photosensitizers over the past five years, including: (i) biorthogonal activatable BODIPYs; (ii) activatable Se‐rhodamine with single‐cell resolution; (iii) silicon phthalocyanine targeting oxygen tension; (iv) general D‐π‐A scaffolds; and (v) AIEgens. The potential challenges and opportunities for developing new types of activatable organic photosensitizers to overcome the hypoxia dilemmas of photodynamic therapy are discussed.
Anthracene−Pentacene Dyads: Synthesis and OFET Characterization
Authors: Hauschild Miriam , Chen Lan , Etschel Sebastian H. , Ferguson Michael J. , Hampel Frank , Halik Marcus , Tykwinski Rik R. 
Published: May 2020

AbstractThe synthesis of a series of unsymmetrical derivatives of pentacene appended with functionalized anthracene moieties is reported. These anthracene−pentacene dyads have been characterized by UV‐vis spectroscopy and cyclic voltammetry to examine their electronic properties. X‐ray crystallographic analysis was used to examine the solid‐state features of anthracene−pentacene dyads 1 a–d with H−, F−, Cl−, and Br− substituents on the 9‐position of anthracene, and shows that the packing arrangement of anthracene−pentacene derivatives 1 b,d,e are remarkably similar irrespective of the presence of fluoride, bromide or methyl substituents. The pentacene−anthracene dyads have been incorporated into OTFTs to evaluate their semiconducting properties. The pentacene derivative 1 b shows ambipolar behavior using AlOx C14PA as the gate dielectric (electron and hole mobilities of 7.6 ⋅ 10−3 and 1.6 ⋅ 10−1 cm2 V−1 s−1), while performance of all derivatives was poor using p‐doped Silicon as the substrate. These studies highlight the importance of thin‐film formation over molecular structure.
Robustness of close‐kin mark–recapture estimators to dispersal limitation and spatially varying sampling probabilities
Authors: Conn Paul B. , Bravington Mark V. , Baylis Shane , Ver Hoef Jay M. 
Published: May 2020

Abstract

Close‐kin mark–recapture (CKMR) is a method for estimating abundance and vital rates from kinship relationships observed in genetic samples. CKMR inference only requires animals to be sampled once (e.g., lethally), potentially widening the scope of population‐level inference relative to traditional monitoring programs.

One assumption of CKMR is that, conditional on individual covariates like age, all animals have an equal probability of being sampled. However, if genetic data are collected opportunistically (e.g., via hunters or fishers), there is potential for spatial variation in sampling probability that can bias CKMR estimators, particularly when genetically related individuals stay in close proximity.

We used individual‐based simulation to investigate consequences of dispersal limitation and spatially biased sampling on performance of naive (nonspatial) CKMR estimators of abundance, fecundity, and adult survival. Population dynamics approximated that of a long‐lived mammal species subject to lethal sampling.

Naive CKMR abundance estimators were relatively unbiased when dispersal was unconstrained (i.e., complete mixing) or when sampling was random or subject to moderate levels of spatial variation. When dispersal was limited, extreme variation in spatial sampling probabilities negatively biased abundance estimates. Reproductive schedules and survival were well estimated, except for survival when adults could emigrate out of the sampled area. Incomplete mixing was readily detected using Kolmogorov–Smirnov tests.

Although CKMR appears promising for estimating abundance and vital rates with opportunistically collected genetic data, care is needed when dispersal limitation is coupled with spatially biased sampling. Fortunately, incomplete mixing is easily detected with adequate sample sizes. In principle, it is possible to devise and fit spatially explicit CKMR models to avoid bias under dispersal limitation, but development of such models necessitates additional complexity (and possibly additional data). We suggest using simulation studies to examine potential bias and precision of proposed modeling approaches prior to implementing a CKMR program.
Ringed seal (Pusa hispida) seasonal movements, diving, and haul‐out behavior in the Beaufort, Chukchi, and Bering Seas (2011–2017)
Authors: Von Duyke Andrew L. , Douglas David C. , Herreman Jason K. , Crawford Justin A. 
Published: May 2020

AbstractContinued Arctic warming and sea‐ice loss will have important implications for the conservation of ringed seals, a highly ice‐dependent species. A better understanding of their spatial ecology will help characterize emerging ecological trends and inform management decisions. We deployed satellite transmitters on ringed seals in the summers of 2011, 2014, and 2016 near Utqiaġvik (formerly Barrow), Alaska, to monitor their movements, diving, and haul‐out behavior. We present analyses of tracking and dive data provided by 17 seals that were tracked until at least January of the following year. Seals mostly ranged north of Utqiaġvik in the Beaufort and Chukchi Seas during summer before moving into the southern Chukchi and Bering Seas during winter. In all seasons, ringed seals occupied a diversity of habitats and spatial distributions, from near shore and localized, to far offshore and wide‐ranging in drifting sea ice. Continental shelf waters were occupied for >96% of tracking days, during which repetitive diving (suggestive of foraging) primarily to the seafloor was the most frequent activity. From mid‐summer to early fall, 12 seals made ~1‐week forays off‐shelf to the deep Arctic Basin, most reaching the retreating pack‐ice, where they spent most of their time hauled out. Diel activity patterns suggested greater allocation of foraging efforts to midday hours. Haul‐out patterns were complementary, occurring mostly at night until April‐May when midday hours were preferred. Ringed seals captured in 2011—concurrent with an unusual mortality event that affected all ice‐seal species—differed morphologically and behaviorally from seals captured in other years. Speculations about the physiology of molting and its role in energetics, habitat use, and behavior are discussed; along with possible evidence of purported ringed seal ecotypes.
Experiencing Community in a Covid Surge
Authors: Mukherjee Debjani 
Published: May 2020

AbstractAs I organize a pile of ethics consult chart notes in New York City in mid‐April 2020, I look at the ten cases that I have co‐consulted on recently. Nine of the patients were found to be Covid positive. The reasons for the consults are mostly familiar—surrogate decision‐making, informed refusal of treatment, goals of care, defining futility. But the context is unfamiliar and unsettling. Bioethicists are in pandemic mode, dusting off and revising triage plans. Patients and potential patients are fearful—of the disease itself and of the amplification of health disparities and inequities. There is much to contemplate, but as I go through my cases, I worry about disability, about biases and racist stereotypes. In this pandemic, historically marginalized communities are at risk of further disenfranchisement.
Do southern Appalachian Mountain summer stream temperatures respond to removal of understory rhododendron thickets?
Authors: Raulerson Scott , Jackson C. Rhett , Melear Nathan D. , Younger Seth E. , Dudley Maura , Elliott Katherine J. 
Published: May 2020

AbstractDense understory thickets of the native evergreen shrubRhododendron maximumexpanded initially following elimination of American chestnut by the chestnut blight, and later in response to loss of the eastern hemlock due to hemlock woolly adelgid invasion. Rhododendron thickets often blanket streams and their riparian zones, creating cool, low‐light microclimates. To determine the effect of such understory thickets on summer stream temperatures, we removed riparian rhododendron understory on 300 m reaches of two southern Appalachian Mountain headwater streams, while leaving two 300 m reference reaches undisturbed. Overhead canopy was left intact in all four streams, but all streams were selected to have a significant component of dead or dying eastern hemlock in the overstory, creating time‐varying canopy gaps throughout the reach. We continuously monitored temperatures upstream, within and downstream of treatment and reference reaches. Temperatures were monitored in all four streams in the summer before treatments were imposed (2014), and for two summers following treatment (2015, 2016). Temperatures varied significantly across and within streams prior to treatment and across years for the reference streams. After rhododendron removal, increases in summer stream temperatures were observed at some locations within the treatment reaches, but these increases did not persist downstream and varied by watershed, sensor, and year. Significant increases in daily maxima in treatment reaches ranged from 0.9 to 2.6°C. Overhead canopy provided enough shade to prevent rhododendron removal from increasing summer temperatures to levels deleterious to native cold‐water fauna (average summer temperatures remained below 16°C), and local temperature effects were not persistent.
Transpiration and evaporation of grassland using land surface modelling
Authors: Ma Wenchao , Wei Zhongwang , Wang Pei , Asanuma Jun 
Published: May 2020

AbstractPartitioning transpiration (T) from evapotranspiration (ET) is a key process for understanding the interaction between land surfaces and the atmosphere. This paper reports daily partitioning results for a grassland over a 10‐year period, obtained using the Community Land Model 3.5 (CLM3.5) land surface model. Hourly forcing data were collected from a long‐term observation system located in the northeast of Japan (http://doi.org/10.24575/0001.198108). To test the model behavior, total ET was validated using eddy correlation measurements combined with the energy balance method. The results were compared with previous research using an isotope approach for partitioning. The results demonstrate that our model can capture the dynamics of ET and its components at this location. Evaporation (E), originating from the ground and canopy, varied inter‐annually, and from 2006 to 2015, average annual E was approximately 285 mm/year from the ground and 45 mm/year from the canopy. Average, T, was approximately 302 mm/year, accounting for approximately 48% of the total ET. Inter‐annual results demonstrate that the water flux transported by vegetation ranges from 17 to 83% during the April–October period. A sensitivity test conducted with forcing data indicates air temperature, incident solar radiation, and longwave radiation exhibited a notable effect on all ET components. Relative humidity exhibited the only negative feedback to both evaporation and transpiration, contrary to the other forcing parameters. Our study reemphasized the effectiveness of CLM3.5 in partitioning T from ET and in understanding the complex interaction between land surfaces and the atmosphere.