bluuebunny/crossref_metadata_2025 huggingface dataset:
What Is Water Hammer, and Why Does It Matter?
Authors: Fallon Timothy
Published: May 2021

A sudden pressure increase of fluid in a pipe, called water hammer, can cause pipes to burst or collapse. With adequate knowledge and training, and by selecting the right equipment, the costly damage from water hammer is preventable.
Make the Most of Water Taste Tests
Authors: Burlingame Gary A.
Published: May 2021

There are many factors to consider when conducting a water taste test, some more obvious than others. It's especially important to consider the categories of different waters as well as how the water is collected and prepared for testing.
Solving Water Infrastructure Mysteries Through Social Media
Authors: Water News Network
Published: May 2021

How many people drive or walk past pipes sticking out of the ground and wonder, “What is that thing?” While sitting in his car at a red light one day in northern San Diego County, John Carnegie, customer services manager for Olivenhain Municipal Water District (OMWD), Encinitas, Calif., realized that some members of the public probably aren't aware of how key water infrastructure objects in their neighborhoods play a role in delivering safe, reliable water.
A novel rapid cure epoxy resin with internal mold release
Authors: Reichanadter Alex , Bank Dave , Mansson Jan‐Anders E.
Published: May 2021

Mold preparation, material layup, and cure times for thermoset‐based composites often limit their use in high‐volume applications. As such, new rapid cure epoxy resins are being developed to achieve a complete cycle time within 3 min. In this research, calorimetry and rheometry are used to examine and model two novel rapid cure epoxy resin systems with internal mold release. The rapid cure epoxy resins followed an autocatalytic cure kinetic and William–Landel–Ferry diffusion model. The rapid cure epoxy resin was shown to achieve 94% cure in 2 min at 150°C. However, adding an additional 2.5 wt% internal mold release hindered the first step of the reaction, which delayed the second reaction step since the final degrees of cure were similar. Furthermore, the resin viscosity followed a modified William–Landel–Ferry equation and at 120°C could maintain a viscosity below 5 Pa s for 4.1 min. These models provided valuable insight into the range of processing conditions these novel resins could experience during impregnation and molding processes.
G‐Algebroids: A Unified Framework for Exceptional and Generalised Geometry, and Poisson–Lie Duality
Authors: Bugden Mark , Hulík Ondřej , Valach Fridrich , Waldram Daniel
Published: May 2021

We introduce the notion of ‐algebroid, generalising both Lie and Courant algebroids, as well as the algebroids used in exceptional generalised geometry for . Focusing on the exceptional case, we prove a classification of “exact” algebroids and translate the related classification of Leibniz parallelisable spaces into a tractable algebraic problem. After discussing the general notion of Poisson–Lie duality, we show that the Poisson–Lie U‐duality is compatible with the equations of motion of supergravity.
Pharmacologic activities of phytosteroids in inflammatory diseases: Mechanism of action and therapeutic potentials
Authors: Marahatha Rishab , Gyawali Kabita , Sharma Kabita , Gyawali Narayan , Tandan Parbati , Adhikari Ashma , Timilsina Grishma , Bhattarai Salyan , Lamichhane Ganesh , Acharya Ashis , Pathak Ishwor , Devkota Hari Prasad , Parajuli Niranjan
Published: May 2021

Natural products and their derivatives are known to be useful for treating numerous diseases since ancient times. Because of their high therapeutic potentials, the use of different medicinal plants is possible to treat varied inflammation‐mediated chronic diseases. Among natural products, phytosteroids have emerged as promising compounds mostly because they have diverse pharmacological activities. Currently, available medications exert numerous systemic toxicities, including hypertension, immune suppression, osteoporosis, and metabolic abnormalities. Thus, further research on phytosteroids to subside these complications is of significant importance. In this study, the information on phytosteroids, their types, and actions against inflammation, and allergic complications was collected by a systematic survey of literature on several scientific search engines. The literature review suggested that phytosteroids exhibit antiinflammatory action via different modes through transrepression or selective COX‐2 enzymes. Also, in silico ADMET analysis was carried out on available phytosteroids to uncover their pharmacokinetic properties. Our analysis has shown that eight compounds: withaferin A, stigmasterol, β‐sitosterol, guggulsterone, diosgenin, sarsasapogenin, physalin A, and dioscin, −isolated from medicinal plants show similar pharmacokinetic properties as compared to dexamethasone, commercially available glucocorticoid. These phytosteroids could be useful for the treatment of inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, asthma, and cardiovascular diseases. Thus, systematic research is required to explore potent phytosteroids with lesser side effects, which might substitute the current medications.
A randomized, double‐blind, placebo‐controlled, clinical trial to evaluate the benefits of Nigella sativa seeds oil in reducing cardiovascular risks in hypertensive patients
Authors: Shoaei‐Hagh Parisa , Kamelan Kafi Farzaneh , Najafi Sara , Zamanzadeh Mansoureh , Heidari Bakavoli Alireza , Ramezani Javad , Soltanian Samira , Asili Javad , Hosseinzadeh Hossein , Eslami Saeid , Taherzadeh Zhila
Published: May 2021

The efficacy, safety, and utility of Nigella sativa seeds oil as a complementary treatment for hypertension, glucose control, and lipid metabolism were evaluated. Hypertensive patients in the intervention (n = 26) and placebo (n = 29) groups received 2.5 ml of N. sativa seeds oil and sunflower oil twice daily for 8 weeks, respectively. The levels of systolic and diastolic blood pressure (SBP, DBP), blood lipid profile, and fasting blood sugar (FBS), at different stages of the treatment period (0, 3, 6, 8 weeks), and malondialdehyde (MDA) and glutathione reductase (GR), at the baseline and end of the study, were assessed. SBP level in the intervention group was significantly reduced, compared with the baseline values (p < .001) and the placebo group (p < .05). A significant decline was observed in the levels of DBP, total cholesterols, and low density lipoprotein (LDL) (p < .000), MDA, and FBS (p < .001); also, a significant increase was observed in the levels of high density lipoprotein (HDL) and GR (p < .001). The use of N. sativa seeds oil as an adjunct to common medications exhibited additional antihypertensive effects as well as beneficial effects on glucose control and lipid metabolism in hypertensive patients with no renal, hepatic, and patient‐reported adverse events.
Clozapine‐induced pancreatitis
Authors: Lam Y. W. Francis
Published: May 2021

Clozapine is highly effective in managing patients with treatment‐resistant schizophrenia. However, use of this atypical antipsychotic is associated with a highly variable pharmacokinetic profile and the occurrence of significant side effects, such as potentially fatal agranulocytosis. Pancreatitis is another adverse effect that has been reported in the literature. The following case describes a patient receiving clozapine who developed acute pancreatitis with multi‐organ involvement.
Defining Pathways of Anaerobic Alkane Oxidation: Synthesis of Enantiomers of 4‐Methylalkanoic Acids and (2‐Methylalkyl)malonic Acids
Authors: Drozdowska Marta , Tromans Jay , Zhang Bian , Jarling René , Wilkes Heinz , Golding Bernard T.
Published: May 2021

The coenzyme A (CoA) esters of 4‐methylalkanoic acids are pivotal intermediates in metabolism of alkanes by anaerobic bacteria found in O2‐deprived environments. A generic method for synthesis of either (R)‐ or (S)‐acid in high enantiomeric purity from enantiomers of methyl 3‐hydroxy‐2‐methylpropionate is described for (R)‐ and (S)‐4‐methyloctanoic acid and (R)‐4‐methyldodecanoic acid. In a typical procedure silyl‐protection of methyl (S)‐3‐hydroxy‐2‐methylpropionate was followed by reduction of the ester to a primary alcohol, which was tosylated. Cu(I)‐catalysed cross‐coupling of the tosylate with propylmagnesium chloride followed by deprotection, tosylation and base‐induced reaction with di‐t‐butyl malonate, gave di‐t‐butyl (R)‐(2‐methylhexyl)malonate. Microwave heating of the diester in 2,2,2‐trifluoroethanol gave a 42 % overall yield of (R)‐4‐methyloctanoic acid, which was shown to be the enantiomer derived by metabolism of hexane by proteobacterium Aromatoleum sp. HxN1. Deprotection of the diester with trifluoroacetic acid gave (R)‐2‐(2‐methylhexyl)malonic acid, which is the biological precursor of (R)‐4‐methyloctanoic acid (via CoA esters).
Tuning Valleys and Wave Functions of van der Waals Heterostructures by Varying the Number of Layers: A First‐Principles Study
Authors: Ramzan Muhammad S. , Kunstmann Jens , Kuc Agnieszka B.
Published: May 2021

In van der Waals heterostructures of 2D transition‐metal dichalcogenides (2D TMDCs) electron and hole states are spatially localized in different layers forming long‐lived interlayer excitons. Here, the influence of additional electron or hole layers on the electronic properties of a MoS2/WSe2 heterobilayer (HBL), which is a direct bandgap material, is investigated from first principles. Additional layers modify the interlayer hybridization, mostly affecting the quasiparticle energy and real‐space extend of hole states at the Γ and electron states at the Q valleys. For a sufficient number of additional layers, the band edges move from K to Q or Γ, respectively. Adding electron layers to the HBL leads to more delocalized K and Q states, while Γ states do not extend much beyond the HBL, even when more hole layers are added. These results suggest a simple and yet powerful way to tune band edges and the real‐space extent of the electron and hole wave functions in TMDC heterostructures, potentially affecting strongly the lifetime and dynamics of interlayer excitons.
Enhancing Hydrogen Evolution Electrocatalytic Performance in Neutral Media via Nitrogen and Iron Phosphide Interactions
Authors: Zhao Siyu , Xie Ruikuan , Kang Liqun , Yang Manni , He Xingyu , Li Wenyao , Wang Ryan , Brett Dan J. L. , He Guanjie , Chai Guoliang , Parkin Ivan P.
Published: May 2021

It remains a challenge to develop efficient electrocatalysts in neutral media for hydrogen evolution reaction (HER) due to the sluggish kinetics and switch of the rate determining step. Although metal phosphides are widely used HER catalysts, their structural stability is an issue due to oxidization, and the HER performance in neutral media requires improvement. Herein, a new material, i.e., grapevine‐shaped N‐doped iron phosphide on carbon nanotubes, as an efficient HER catalyst in neutral media is developed. The optimized catalyst shows an overpotential of 256 mV at a large current density of 65 mA cm−2, which is even 10 mV lower than that of the commercial 20% Pt/C catalyst. The excellent performance of the catalyst is further studied by combined computational and experimental techniques, which proves that the interaction between nitrogen and iron phosphides can provide more efficient active structures and stabilize the metal phosphide electrocatalysts for HER.
Mefepronic acid is associated with a decrease in serum liver enzyme activities in dogs with suspected hepatopathy
Authors: Quintavalla Fausto , Gelsi Elisa , Battaglia Luca , Aldigeri Raffaella , Ramoni Roberto
Published: May 2021

Although suspected hepatopathy in dogs can be assessed by the blood levels of both liver enzyme activities and functional liver parameters, very often the precise diagnosis of primary or secondary hepatobiliary diseases can remain uncertain. Therefore, in a number of patients, the therapeutic intervention has the purpose of slowing the progression of fibrosis and provide for optimal hepatic support. Recently the PPARs (peroxisome proliferator‐activated receptors) have been identified as a family of hepatic nuclear hormonal receptors, involved in the regulation of lipid and glucose metabolism. The aim of this work is to assess the effect of mefepronic acid (PMPA), a PPAR agonist, on liver enzyme markers in blood samples of dogs with suspected hepatopathies. Twenty dogs, with suspected hepatopathies, were divided into two groups: ten of them received subcutaneously daily 10 mg/kg of PMPA for 7 days (treated, group T), while the remaining dogs were treated with a conventional supportive treatment for hepatopathies consisting of ursodeoxycholic acid (UDCA) 10 mg/kg PO SID for 45 days (control, group C). PMPA yielded a faster decrease in liver enzyme activities compared to UDCA, that in most cases was maintained after the suspension of the treatment. These data suggest that PMPA might be considered as supportive treatment for dogs with suspected hepatopathy.
Preparation of β‐cyclodextrin/SBS modified asphalts for the improvement of anti‐aging, rheological property, and storage stability
Authors: Han Hanzhi , Cheng Youliang , Fang Changqing , Zhang Qingling , Hu Jingbo
Published: May 2021

Styrene‐butadiene‐styrene (SBS) modified asphalt (SMA) has been widely used in road engineering for decade. However, the phase separation of SMA was obvious during the transport and SBS degraded after aging. To resolve these problems, β‐cyclodextrin (β‐CD) was used to modify SMA in this work. Conventional properties, storage stability, the effect of short‐term aging on the morphology, and rheological property for SMA and β‐CD/SMA were investigated. The softening point of modified asphalt reached to the maximum of 66.7°C when 1 wt% β‐CD was added to SMA, where the penetration had shown the minimum of 80.8 dmm. In addition, the ductility of β‐CD/SMA increased to the maximum of 797 mm when the content of β‐CD was increased to 5 wt%. Furthermore, incorporation of β‐CD improved the storage stability of SMA. Importantly, the aggregation of SBS was observed in β‐CD/SMA, but modifiers distributed uniformly after a short‐term aging. The rutting resistance and antiaging performances of SMA were also improved by the addition of β‐CD. Considering the comprehensive properties of modified asphalt, the optimum content of β‐CD was found to be 2 wt%.
Analytic study of dark photon and gravitational wave production from axion
Authors: Salehian Borna , Gorji Mohammad Ali , Mukohyama Shinji , Firouzjahi Hassan
Published: May 2021

Abstract

Axion-like fields heavier than about 10−27eV are expected to oscillate in the radiation dominated epoch when the Hubble parameter drops below their mass. Considering the Chern-Simons coupling with a dark gauge boson, large amount of dark photons are produced during a short time interval through tachyonic resonance instability. The produced dark photons then source gravitational tensor modes leading to chiral gravitational waves. Through this process, one can indirectly probe a large parameter space of coupled axion-dark photon models. In this work we first find an analytic expression for the number density of the dark photons produced during the tachyonic resonance regime. Second, by using the saddle point approximation we find an analytic expression for the gravitational wave spectrum in terms of the mass, coupling and misalignment angle. Our analytic results can be used for the observational analysis of these types of scenarios.
Bottom-induced contributions to Higgs plus jet at next-to-next-to-leading order
Authors: Mondini Roberto , Williams Ciaran
Published: May 2021

Abstract

We present a next-to-next-to-leading order (NNLO) QCD calculation of the bottom-induced contributions to the production of a Higgs boson plus a jet, i.e. the process pp → H + j to $$ \mathcal{O}\left({y}_b^2{\alpha}_s^3\right) $$
O

y
b
2

α
s
3

. We work in the five-flavor scheme (5FS) in which the bottom quark mass is retained only in the coupling to the Higgs boson. Our calculation uses N-jettiness slicing to regulate infrared divergences, allowing for fully-differential predictions for collider observables. After extensively validating the methodology, we present results for the 13 TeV LHC. Our NNLO predictions show a marked improvement in the overall renormalization and factorization scale dependence, the latter of which proves to be particularly troublesome for 5FS calculations at lower orders. In addition, using the same methodology we present a NNLO computation of $$ b\overline{b} $$
b

b
¯

→ H. Our results are implemented into MCFM.
Implications of the XENON1T excess on the dark matter interpretation
Authors: Alhazmi Haider , Kim Doojin , Kong Kyoungchul , Mohlabeng Gopolang , Park Jong-Chul , Shin Seodong
Published: May 2021

Abstract

The dark matter interpretation for a recent observation of excessive electron recoil events at the XENON1T detector seems challenging because its velocity is not large enough to give rise to recoiling electrons of $$ \mathcal{O}\left(\mathrm{keV}\right) $$
O

keV

. Fast-moving or boosted dark matter scenarios are receiving attention as a remedy for this issue, rendering the dark matter interpretation a possibility to explain the anomaly. We investigate various scenarios where such dark matter of spin 0 and 1/2 interacts with electrons via an exchange of vector, axial-vector, pseudo-scalar, or scalar mediators. We find parameter values not only to reproduce the excess but to be consistent with existing bounds. Our study suggests that the scales of mass and coupling parameters preferred by the excess can be mostly affected by the type of mediator, and that significantly boosted dark matter can explain the excess depending on the mediator type and its mass choice. The method proposed in this work is general, and hence readily applicable to the interpretation of observed data in the dark matter direct detection experiment.
Anisotropic Curvature Flow of Immersed Networks
Authors: Kröner Heiko , Novaga Matteo , Pozzi Paola
Published: May 2021

We consider motion by anisotropic curvature of a network of three curves immersed in the plane meeting at a triple junction and with the other ends fixed. We show existence, uniqueness and regularity of a maximal geometric solution and we prove that, if the maximal time is finite, then either the length of one of the curves goes to zero or the $$L^2$$

L
2

-norm of the anisotropic curvature blows up.
Orthogonality relations of Crouzeix–Raviart and Raviart–Thomas finite element spaces
Authors: Bartels Sören , Wang Zhangxian
Published: May 2021

Identities that relate projections of Raviart–Thomas finite element vector fields to discrete gradients of Crouzeix–Raviart finite element functions are derived under general conditions. Various implications such as discrete convex duality results and a characterization of the image of the projection of the Crouzeix–Ravaiart space onto elementwise constant functions are deduced.
Student perceptions of interpersonal justice, engagement, agency and anger: a longitudinal study for reciprocal effects
Authors: Mameli Consuelo , Grazia Valentina , Passini Stefano , Molinari Luisa
Published: May 2021

Based on the premise that classroom interactions unfold through a complex series of circular influences between teacher and students, the aim of this longitudinal study was to test a reciprocal effects model connecting students’ perceptions of interpersonal justice, on the one hand, and student engagement, agency and anger, on the other. Self-report measures of interpersonal justice, student engagement, agency and anger were collected from 454 Year Nine students from Northern Italy in a 3-wave longitudinal research design. Structural equation modelling with latent variables indicated that interpersonal justice in wave 1 had a negative effect on both student agency and anger in wave 2, while interpersonal justice in wave 2 only negatively predicted student anger in wave 3. With respect to the reciprocal effects, student engagement in wave 2 was found to positively predict interpersonal justice in wave 3, while a negative effect close to statistical significance was observed from student agency in wave 2 to interpersonal justice in wave 3. These results are discussed in terms of their implications for teacher practice, as they emphasize that (a) the two main facets of student participation, namely engagement and agency, are differently interconnected with the learning environment, and (b) the perception of being treated fairly is important to the point that its deficiency triggers a persistent feeling of anger in students.
“Grey swan” storm surges pose a greater coastal flood hazard than climate change
Authors: Horsburgh Kevin , Haigh Ivan D. , Williams Jane , De Dominicis Michela , Wolf Judith , Inayatillah Addina , Byrne David
Published: May 2021

In this paper, we show that over the next few decades, the natural variability of mid-latitude storm systems is likely to be a more important driver of coastal extreme sea levels than either mean sea level rise or climatically induced changes to storminess. Due to their episodic nature, the variability of local sea level response, and our short observational record, understanding the natural variability of storm surges is at least as important as understanding projected long-term mean sea level changes due to global warming. Using the December 2013 North Atlantic Storm Xaver as a baseline, we used a meteorological forecast modification tool to create “grey swan” events, whilst maintaining key physical properties of the storm system. Here we define “grey swan” to mean an event which is expected on the grounds of natural variability but is not within the observational record. For each of these synthesised storm events, we simulated storm tides and waves in the North Sea using hydrodynamic models that are routinely used in operational forecasting systems. The grey swan storms produced storm surges that were consistently higher than those experienced during the December 2013 event at all analysed tide gauge locations along the UK east coast. The additional storm surge elevations obtained in our simulations are comparable to high-end projected mean sea level rises for the year 2100 for the European coastline. Our results indicate strongly that mid-latitude storms, capable of generating more extreme storm surges and waves than ever observed, are likely due to natural variability. We confirmed previous observations that more extreme storm surges in semi-enclosed basins can be caused by slowing down the speed of movement of the storm, and we provide a novel explanation in terms of slower storm propagation allowing the dynamical response to approach equilibrium. We did not find any significant changes to maximum wave heights at the coast, with changes largely confined to deeper water. Many other regions of the world experience storm surges driven by mid-latitude weather systems. Our approach could therefore be adopted more widely to identify physically plausible, low probability, potentially catastrophic coastal flood events and to assist with major incident planning.
Surface effects on a mode-III reinforced nano-elliptical hole embedded in one-dimensional hexagonal piezoelectric quasicrystals
Authors: Zhao Zhina , Guo Junhong
Published: May 2021

To effectively reduce the field concentration around a hole or crack, an anti-plane shear problem of a nano-elliptical hole or a nano-crack pasting a reinforcement layer in a one-dimensional (1D) hexagonal piezoelectric quasicrystal (PQC) is investigated subject to remotely mechanical and electrical loadings. The surface effect and dielectric characteristics inside the hole are considered for actuality. By utilizing the technique of conformal mapping and the complex variable method, the phonon stresses, phason stresses, and electric displacements in the matrix and reinforcement layer are exactly derived under both electrically permeable and impermeable boundary conditions. Three size-dependent field intensity factors near the nano-crack tip are further obtained when the nano-elliptical hole is reduced to the nano-crack. Numerical examples are illustrated to show the effects of material properties of the surface layer and reinforced layer, the aspect ratio of the hole, and the thickness of the reinforcing layer on the field concentration of the nano-elliptical hole and the field intensity factors near the nano-crack tip. The results indicate that the properties of the surface layer and reinforcement layer and the electrical boundary conditions have great effects on the field concentration of the nano-hole and nano-crack, which are useful for optimizing and designing the microdevices by PQC nanocomposites in engineering practice.
Innovative Bio-based Poly(Lactic Acid)/Poly(Alkylene Furanoate)s Fiber Blends for Sustainable Textile Applications
Authors: Perin Davide , Rigotti Daniele , Fredi Giulia , Papageorgiou George Z. , Bikiaris Dimitrios N. , Dorigato Andrea
Published: May 2021

This work aims at producing and investigating, for the first time, the microstructural and thermo-mechanical properties of fibers constituted by poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAFs) blends for textile applications. Two different PAFs have been investigated, i.e., poly(octylene furanoate) (P8F) and poly(dodecylene furanoate) (P12F), which have been blended with PLA in different concentrations and spun through a lab-made wet spinning device. The microstructural investigation of the fiber cross-section evidenced domains of PAFs homogeneously dispersed within the PLA matrix. The immiscibility of the produced blends was also suggested by the fact that the glass transition temperature of PLA was unaffected by the presence of PAF. The thermal stability of PLA was not substantially influenced by the PAF content, whereas the water absorption tendency decreased with an increase in P12F fraction. The mechanical properties of PLA/P8F blends decreased with the P8F amount, while for PLA/P12F fiber blends the stiffness and the strength were approximatively constant by increasing the P12F content. The drawing process, performed at 70 °C and with two different draw ratios, brought an interesting increase in the mechanical properties of PLA fibers upon P12F introduction. These promising results constitute the basis for future research on these innovative bio-based fibers.
Importance sampling in reinforcement learning with an estimated behavior policy
Authors: Hanna Josiah P. , Niekum Scott , Stone Peter
Published: May 2021

In reinforcement learning, importance sampling is a widely used method for evaluating an expectation under the distribution of data of one policy when the data has in fact been generated by a different policy. Importance sampling requires computing the likelihood ratio between the action probabilities of a target policy and those of the data-producing behavior policy. In this article, we study importance sampling where the behavior policy action probabilities are replaced by their maximum likelihood estimate of these probabilities under the observed data. We show this general technique reduces variance due to sampling error in Monte Carlo style estimators. We introduce two novel estimators that use this technique to estimate expected values that arise in the RL literature. We find that these general estimators reduce the variance of Monte Carlo sampling methods, leading to faster learning for policy gradient algorithms and more accurate off-policy policy evaluation. We also provide theoretical analysis showing that our new estimators are consistent and have asymptotically lower variance than Monte Carlo estimators.
Cross-Dimension Mining Model of Public Opinion Data in Online Education Based on Fuzzy Association Rules
Authors: Li Li-xuan , Huo Ying , Lin Jerry Chun-Wei
Published: May 2021

The multi-dimensional characteristics of public opinion in online education lead to the difficulty of data cross-dimensional mining. To solve this problem, this paper designs a cross-dimensional data mining model of public opinion in online education based on fuzzy association rules. Based on the public opinion subject, object, and ontology to analyze the characteristics of public opinion in online education, Yaahp software is used to calculate the influence factor weight of public opinion in online education. According to the weight analysis results, the relationship between the dimensions of various public opinion data is clarified by using data semantic association. This paper introduces the fuzzy set theory into the database and uses crawlers to obtain public opinion data and stores them in the database, to complete the data preprocessing through distributed text preprocessing, feature selection distributed computing, and text vectorization distributed computing. Taking the cloud computing platform as the core, the cross-dimension mining model of public opinion in online education data is constructed according to the dimension correlation analysis and preprocessing results. The simulation results show that the model has the advantages of wide range, fast speed, and high accuracy, and can provide data support for education reform.
A phase I/II study of bevacizumab, irinotecan and erlotinib in children with progressive diffuse intrinsic pontine glioma
Authors: El-Khouly Fatma E. , Veldhuijzen van Zanten Sophie E. M. , Jansen Marc H. A. , Bakker Dewi P. , Sanchez Aliaga Esther , Hendrikse N. Harry , Vandertop W. Peter , van Vuurden Dannis G. , Kaspers Gertjan J. L.
Published: May 2021

Introduction

This study investigates the safety, tolerability, and preliminary efficacy of combined treatment with VEGF inhibitor bevacizumab, topoisomerase I inhibitor irinotecan, and EGFR inhibitor erlotinib in children with progressive diffuse intrinsic pontine glioma (DIPG).

Methods

Biweekly bevacizumab (10 mg/kg) and irinotecan (125 mg/m2) were combined with daily erlotinib. Two cohorts received increasing doses of erlotinib (65 and 85 mg/m2) following a 3 + 3 dose-escalation schedule, until disease progression with a maximum of one year. Dose-limiting toxicities (DLT) were monitored biweekly. Secondary progression free survival (sPFS) and overall survival (OS) were determined based on clinical and radiological response measurements. Quality of life (QoL) during treatment was also assessed.

Results

Between November 2011 and March 2018, nine patients with disease progression after initial radiotherapy were enrolled. Median PFS at start of the study was 7.3 months (range 3.5–10.0). In the first dose cohort, one patient experienced a DLT (grade III acute diarrhea), resulting in enrollment of three additional patients in this cohort. No additional DLTs were observed in consecutive patients receiving up to a maximum dose of 85 mg/m2. Median sPFS was 3.2 months (range 1.0–10.9), and median OS was 13.8 months (range 9.3–33.0). Overall QoL was stable during treatment.

Conclusions

Daily erlotinib is safe and well tolerated in doses up to 85 mg/m2 when combined with biweekly bevacizumab and irinotecan in children with progressive DIPG. Median OS of the study patients was longer than known form literature.
A Study of Internet Development and Enterprise Financing in China
Authors: Chen Qiang , Zhang Yabin , Chen Lian
Published: May 2021

The development of the Internet has changed many traditional commercial models of enterprises. Therefore, the term Internet development is increasingly drawing attention from scholars. However, we are not certain whether the development of the Internet improves the problem of difficult financing of enterprises and enhances enterprise financing efficiency. This paper analyzes whether Internet development can promote enterprise financing efficiency. First, the Data Envelopment Analysis- Slack Based Measure (DEA-SBM) model is applied to measure the enterprise financing efficiency values of 31 provinces in China. The measurement results indicate that the enterprise financing efficiency in the eastern regions is higher than that of central and western regions. Then, this paper further tests if Internet development can contribute to enterprise financing efficiency based on an econometric model. The analysis results indicate that Internet development has an obvious promoting effect on enterprise financing efficiency. Later, spatial econometric models are adopted in this paper to further analyze if Internet development has a spatial overflow effect on enterprise financing efficiency. The results indicate that Internet development indeed has a spatial overflow effect on enterprise financing efficiency.
A Liposomal Gemcitabine, FF-10832, Improves Plasma Stability, Tumor Targeting, and Antitumor Efficacy of Gemcitabine in Pancreatic Cancer Xenograft Models
Authors: Matsumoto Takeshi , Komori Takashi , Yoshino Yuta , Ioroi Tadaaki , Kitahashi Tsukasa , Kitahara Hiromu , Ono Kohei , Higuchi Tamami , Sakabe Masayo , Kori Hiroshi , Kano Masahiro , Hori Ritsuko , Kato Yukio , Hagiwara Shinji
Published: May 2021

Purpose

The clinical application of gemcitabine (GEM) is limited by its pharmacokinetic properties. The aim of this study was to characterize the stability in circulating plasma, tumor targeting, and payload release of liposome-encapsulated GEM, FF-10832.

Methods

Antitumor activity was assessed in xenograft mouse models of human pancreatic cancer. The pharmacokinetics of GEM and its active metabolite dFdCTP were also evaluated.

Results

In mice with Capan-1 tumors, the dose-normalized areas under the curve (AUCs) after FF-10832 administration in plasma and tumor were 672 and 1047 times higher, respectively, than after using unencapsulated GEM. The tumor-to-bone marrow AUC ratio of dFdCTP was approximately eight times higher after FF-10832 administration than after GEM administration. These results indicated that liposomal encapsulation produced long-term stability in circulating plasma and tumor-selective targeting of GEM. In mice with Capan-1, SUIT-2, and BxPC-3 tumors, FF-10832 had better antitumor activity and tolerability than GEM. Internalization of FF-10832 in tumor-associated macrophages (TAMs) was revealed by flow cytometry and confocal laser scanning microscopy, and GEM was efficiently released from isolated macrophages of mice treated with FF-10832. These results suggest that TAMs are one of the potential reservoirs of GEM in tumors.

Conclusion

This study found that FF-10832 had favorable pharmacokinetic properties. The liposomal formulation was more effective and tolerable than unencapsulated GEM in mouse xenograft tumor models. Hence, FF-10832 is a promising candidate for the treatment of pancreatic cancer.
A robust and efficient algorithm to find profile likelihood confidence intervals
Authors: Fischer Samuel M. , Lewis Mark A.
Published: May 2021

Profile likelihood confidence intervals are a robust alternative to Wald’s method if the asymptotic properties of the maximum likelihood estimator are not met. However, the constrained optimization problem defining profile likelihood confidence intervals can be difficult to solve in these situations, because the likelihood function may exhibit unfavorable properties. As a result, existing methods may be inefficient and yield misleading results. In this paper, we address this problem by computing profile likelihood confidence intervals via a trust-region approach, where steps computed based on local approximations are constrained to regions where these approximations are sufficiently precise. As our algorithm also accounts for numerical issues arising if the likelihood function is strongly non-linear or parameters are not estimable, the method is applicable in many scenarios where earlier approaches are shown to be unreliable. To demonstrate its potential in applications, we apply our algorithm to benchmark problems and compare it with 6 existing approaches to compute profile likelihood confidence intervals. Our algorithm consistently achieved higher success rates than any competitor while also being among the quickest methods. As our algorithm can be applied to compute both confidence intervals of parameters and model predictions, it is useful in a wide range of scenarios.
Continuous 3D Multi-Channel Sign Language Production via Progressive Transformers and Mixture Density Networks
Authors: Saunders Ben , Camgoz Necati Cihan , Bowden Richard
Published: May 2021

Sign languages are multi-channel visual languages, where signers use a continuous 3D space to communicate. Sign language production (SLP), the automatic translation from spoken to sign languages, must embody both the continuous articulation and full morphology of sign to be truly understandable by the Deaf community. Previous deep learning-based SLP works have produced only a concatenation of isolated signs focusing primarily on the manual features, leading to a robotic and non-expressive production. In this work, we propose a novel Progressive Transformer architecture, the first SLP model to translate from spoken language sentences to continuous 3D multi-channel sign pose sequences in an end-to-end manner. Our transformer network architecture introduces a counter decoding that enables variable length continuous sequence generation by tracking the production progress over time and predicting the end of sequence. We present extensive data augmentation techniques to reduce prediction drift, alongside an adversarial training regime and a mixture density network (MDN) formulation to produce realistic and expressive sign pose sequences. We propose a back translation evaluation mechanism for SLP, presenting benchmark quantitative results on the challenging PHOENIX14T dataset and setting baselines for future research. We further provide a user evaluation of our SLP model, to understand the Deaf reception of our sign pose productions.
VPR-Bench: An Open-Source Visual Place Recognition Evaluation Framework with Quantifiable Viewpoint and Appearance Change
Authors: Zaffar Mubariz , Garg Sourav , Milford Michael , Kooij Julian , Flynn David , McDonald-Maier Klaus , Ehsan Shoaib
Published: May 2021

Visual place recognition (VPR) is the process of recognising a previously visited place using visual information, often under varying appearance conditions and viewpoint changes and with computational constraints. VPR is related to the concepts of localisation, loop closure, image retrieval and is a critical component of many autonomous navigation systems ranging from autonomous vehicles to drones and computer vision systems. While the concept of place recognition has been around for many years, VPR research has grown rapidly as a field over the past decade due to improving camera hardware and its potential for deep learning-based techniques, and has become a widely studied topic in both the computer vision and robotics communities. This growth however has led to fragmentation and a lack of standardisation in the field, especially concerning performance evaluation. Moreover, the notion of viewpoint and illumination invariance of VPR techniques has largely been assessed qualitatively and hence ambiguously in the past. In this paper, we address these gaps through a new comprehensive open-source framework for assessing the performance of VPR techniques, dubbed “VPR-Bench”. VPR-Bench (Open-sourced at: https://github.com/MubarizZaffar/VPR-Bench) introduces two much-needed capabilities for VPR researchers: firstly, it contains a benchmark of 12 fully-integrated datasets and 10 VPR techniques, and secondly, it integrates a comprehensive variation-quantified dataset for quantifying viewpoint and illumination invariance. We apply and analyse popular evaluation metrics for VPR from both the computer vision and robotics communities, and discuss how these different metrics complement and/or replace each other, depending upon the underlying applications and system requirements. Our analysis reveals that no universal SOTA VPR technique exists, since: (a) state-of-the-art (SOTA) performance is achieved by 8 out of the 10 techniques on at least one dataset, (b) SOTA technique in one community does not necessarily yield SOTA performance in the other given the differences in datasets and metrics. Furthermore, we identify key open challenges since: (c) all 10 techniques suffer greatly in perceptually-aliased and less-structured environments, (d) all techniques suffer from viewpoint variance where lateral change has less effect than 3D change, and (e) directional illumination change has more adverse effects on matching confidence than uniform illumination change. We also present detailed meta-analyses regarding the roles of varying ground-truths, platforms, application requirements and technique parameters. Finally, VPR-Bench provides a unified implementation to deploy these VPR techniques, metrics and datasets, and is extensible through templates.
Who Needs the Experts? The Politics and Practices of Alternative Humanitarianism and Its Relationship to NGOs
Authors: Ishkanian Armine , Shutes Isabel
Published: May 2021

Drawing on fieldwork in Greece, we examine the politics and practices of autonomous volunteering in the context of the migration crisis. This involves individuals engaging in activities to support migrants through non-registered, self-organized and self-governed groups that work independent from and in some cases, even in opposition to NGOs. We consider autonomous volunteering as a form of collective action and argue that it constitutes an alternative humanitarianism. While recent literature has sought to identify the rise of emergent practices of alternative humanitarianism in Europe, research has often overlooked how autonomous volunteers distinguish themselves from, relate to and collaborate with NGOs and conversely, how NGOs view and engage with them. We found that despite their critiques of NGOs and their determination to work independently, there were instances of cooperation between autonomous volunteers and NGOs. These interactions did not become substantive alliances, as the work of NGOs and autonomous volunteers continued to be disconnected from each other.
Endothelial dysfunction in obstructive sleep apnea patients
Authors: Harańczyk Michał , Konieczyńska Małgorzata , Płazak Wojciech
Published: May 2021

Purpose

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for cardiovascular diseases. The aim of the study was to assess the influence of OSAS on endothelial dysfunction and thrombosis biomarkers and to evaluate the effect of treatment with continuous positive airway pressure (CPAP) on biomarker levels.

Methods

NT-proBNP, sICAM-1, endothelin-1, von Willebrand factor, D-dimers, and thrombin-antithrombin complex (TAT) were measured in 50 patients diagnosed with moderate-to-severe OSAS. All patients underwent transthoracic echocardiography, and 38 months after the inclusion, 16 CPAP users and 22 non-CPAP users were reassessed.

Results

Sleep-related indices of apnea-hypopnea index (AHI) and mean SpO2were associated with higher sICAM-1 levels (AHI < 30: 7.3 ± 4.7 vs. AHI ≥ 30: 19.5 ± 19.4 mg/ml,p = 0.04; SpO2 ≥ 90%: 11.9 ± 9.3 vs. SpO2 < 90%: 23.6 ± 25.8,p = 0.04). sICAM-1 levels were significantly higher in obese patients, particularly with BMI ≥ 40. Plasma levels of TAT were significantly correlated with the increased right ventricular size (right ventricular diameter ≤ 37 mm: 0.86 ± 0.70 vs. > 37 mm: 1.96 ± 1.20 ng/ml,p = 0.04). Endothelin-1 levels were higher in patients with decreased right ventricular function (right ventricle TDI-derived S′ ≥ 12 cm/s: 11.5 ± 10.9 vs. < 12 cm/s: 26.0 ± 13.2 pg/ml,p = 0.04). An increase in NT-proBNP was related to impaired parameters of the right ventricular contractile function. There were no correlations between long-term CPAP therapy and the levels of biomarkers.

Conclusion

Severe OSAS influences endothelial damage as manifested by an increase in sICAM-1 levels. Changes in right ventricular structure and function, observed mainly in patients with higher TAT and endothelin-1 levels, are also manifested by an increase in NT-proBNP levels. Long-term CPAP treatment does not seem to influence biomarkers in patients with moderate-to-severe OSAS, which may help to explain the lack of influence of CPAP on cardiovascular risk reduction.
Hemodynamic changes of abdominal organs after CT colonography with transrectal administration of CO2: evaluation with early-phase contrast-enhanced dynamic CT
Authors: Ihara Kenichiro , Onoda Hideko , Tanabe Masahiro , Kanki Akihiko , Ito Katsuyoshi
Published: May 2021

Purpose

To evaluate the hemodynamic changes in the liver, pancreas, gastric mucosa and abdominal vessels in early-phase dynamic contrast-enhanced (DCE) CT immediately after CT colonography (CTC) with carbon dioxide expansion.

Materials and methods

This study included 82 patients with DCE-CT after CTC (CTC group) and 77 patients without CTC (control group). Contrast enhancement values of the gastric mucosa, liver, pancreas, portal vein (PV), splenic vein (SpV), superior mesenteric vein (SMV), and inferior mesenteric vein (IMV) in early-phase CT were measured. The presence of hepatic pseudolesions were also recorded.

Results

The mean contrast enhancement values of the gastric mucosa, pancreas and SpV in the CE-CTC group were significantly lower than those in the control group (p < 0.001, p < 0.001, p = 0.014). Conversely, the mean contrast enhancement values of the liver, PV, SMV and IMV in the CE-CTC group were significantly higher than those in the control group (p = 0.003, p = 0.013, p < 0.001, p < 0.001). Hypovascular hepatic pseudolesions were seen in early-phase CT in six patients after CTC, while they were not seen in the control group.

Conclusions

On DCE-CT performed immediately after CTC with carbon dioxide expansion, it is important to be aware of the imaging findings induced by visceral hemodynamic changes.
Role of Exercise as a Modulating Factor in Arrhythmogenic Cardiomyopathy
Authors: Zorzi Alessandro , Cipriani Alberto , Bariani Riccardo , Pilichou Kalliopi , Corrado Domenico , Bauce Barbara
Published: May 2021

Purpose of Review

The review addresses the role of exercise in triggering ventricular arrhythmias and promoting disease progression in arrhythmogenic cardiomyopathy (AC) patients and gene-mutation carriers, the differential diagnosis between AC and athlete’s heart and current recommendations on exercise activity in AC.

Recent Findings

AC is an inherited heart muscle disease caused by genetically defective cell-to-cell adhesion structures (mainly desmosomes). The pathophysiological hallmark of the disease is progressive myocyte loss and replacement by fibro-fatty tissue, which creates the substrates for ventricular arrhythmias. Animal and human studies demonstrated that intense exercise, but not moderate physical activity, may increase disease penetrance, worsen the phenotype, and favor life-threatening ventricular arrhythmias. It has been proposed that in some individuals prolonged endurance sports activity may in itself cause AC (so-called exercise-induced AC).

The studies agree that intense physical activity should be avoided in patients with AC and healthy gene-mutation carriers. However, low-to-moderate intensity exercise does not appear detrimental and these patients should not be entirely deprived from the many health benefits of physical activity.
Should We Be Using Upstream Beta-Blocker Therapy for Acute Myocardial Infarction?
Authors: Giannakopoulos Georgios , Noble Stephane
Published: May 2021

Purpose of Review

Controversy exists whether beta-blockers should be given before primary percutaneous coronary intervention (PCI) or to defer their administration for up to 24 hours.

Recent Findings

Animal studies, most of them conducted in the 1970s and 1980s, showed evidence that early beta-blocker administration may reduce infarct size. Subsequent human studies had mixed results on infarct size and survival. More specifically, in the current primary PCI era, only four studies evaluated the impact of early intravenous beta-blocker administration after acute myocardial infarction, only two of them before PCI. All studies agree that in hemodynamically stable patients, early intravenous beta-blocker administration is safe and protected against malignant arrhythmias. Nevertheless, results on infarct size and mortality are equivocal.

Considering the heterogeneity of currently available data, further studies are still needed to assess the benefit of early injection of metoprolol in STEMI patients in a large double-blinded and randomized design versus placebo.