bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of fiber coating on the mechanical performance, water absorption and biodegradability of sisal fiber/natural rubber composite
Authors: Abdel‐Hakim Ahmed , El‐Wakil Abd El‐Aziz Arafa , El‐Mogy Soma , Halim Sawsan
Published: February 2021

Styrene butyl acrylate (SBA) copolymer latex nanoparticles which contain vinyltrimethoxysilane as binding agent were prepared using microemulsion polymerization and were used for coating sisal fiber. The structure of SBA and coated sisal fiber (CF) was confirmed by Fourier transform infrared spectroscopy. The effect of the surface coating of sisal fiber (SF) on the SF/natural rubber (NR) composite properties was systematically evaluated through curing characteristics, morphological properties, mechanical properties, water absorption resistance, biodegradability and dynamic mechanical analysis. As indicated from the morphological study, the coating of SF with SBA enhanced the interfacial adhesion between SF and the NR matrix. In addition, the tensile strength was improved by 26.9% and 43% after the addition of 5 and 10 phr (parts per hundred rubber), respectively, of CF to NR. The coating process improved the water resistance of SF/NR composite significantly especially at high SF loading level, where the composite that contained 30 phr CF absorbed 6.7% water compared to 13.2% for the composite containing uncoated sisal fiber (UF). Dynamic mechanical analysis confirmed that the coating process improved the interfacial adhesion between the SF and NR matrix as indicated from the higher values of storage modulus and lower values of maximum loss factor (tan δmax) recorded for composites containing CF compared to those containing UF. © 2021 Society of Industrial Chemistry.
Bringing access and benefit sharing into the digital age
Authors: Aubry Sylvain , Frison Christine , Medaglia Jorge C. , Frison Emile , Jaspars Marcel , Rabone Muriel , Sirakaya Aysegul , Saxena Devanshi , van Zimmeren Esther
Published: February 2021

Societal Impact Statement

Reading and writing DNA is now possible with an unprecedented speed and ease. To catch up with digitization of genetic resources, scientists need to join with all relevant stakeholders and design new global governance mechanisms for digital sequence information. We propose the establishment of a Multi‐stakeholder Committee on the Governance of Digital Sequence Information (DSI). This multi‐disciplinary body will be dedicated to mitigate governance issues associated with the digitization of genetic resources. Solving the DSI conundrum is sorely needed given the forthcoming multilateral meetings of the Access and Benefit Sharing (ABS) framework (the next CBD COP is scheduled in 2021) that are central to tackle the global loss of biodiversity, global warming, pandemic risk and food insecurity.

Contemporary research is increasingly data‐centric and the rise of genomics revolutionized our approach and use of genetic resources. However, genomics developed relatively independently from the international instruments on the conservation of biological diversity, in particular the Access and Benefit Sharing (ABS) framework. The legal and political status of Digital Sequence Information (DSI) derived from genetic resources emerged recently as a contentious point in the various ABS instruments dealing with genetic resources. In view of the multiple parallel and uncoordinated debates that occurred in various forums dealing with plants, animals, terrestrial, microbial, marine and agricultural biodiversity, we propose here to take a step back in the discussion. We argue that DSI should be considered as an overarching issue to be addressed through a coordinated and inclusive Multi‐stakeholder Committee that would assess its position and role within the existing ABS regime complex. This Multi‐stakeholder Committee on the Governance of Digital Sequence Information, that may run under the auspices of the United Nations, will be dedicated to mitigate global governance issues associated with the digitization of genetic resources. In this paper, we sketch this body as a transversal and inclusive tool to facilitate long‐term coherence in all ABS policy forums.
Early volume targeted ventilation in preterm infants born at 22–25 weeks of gestational age
Authors: Wallström Linda , Sjöberg Amanda , Sindelar Richard
Published: February 2021

Background

Early hypocapnia in preterm infants is associated with intraventricular hemorrhage (IVH) and bronchopulmonary dysplasia (BPD). Volume targeted ventilation (VTV) has been shown to reduce hypocapnia in preterm infants. Less is known of VTV in infants born at <26 weeks gestational age (GA).

Objectives

Our aim was to investigate the short‐ and long‐term effects of early VTV as compared to pressure limited ventilation (PLV) in extremely preterm infants on the incidence of hypocapnia, days on ventilatory support, IVH, and BPD.

Study Design

A retrospective observational study of 104 infants born at 22–25 weeks GA (mean ± SD; 24+0 ± 1+1 GA; birth weight 619 ± 146 g), ventilated with either VTV (n = 44) or PLV (n = 60) on their first day of life. Ventilatory data and blood gases were collected at admission and every fourth hour during the first day of life, together with perinatal characteristics and outcomes.

Results

Peak inflation pressure (PIP) was lower in the VTV‐group than in the PLV‐group during the first 20 h of life (p < .05), without any difference in respiratory rate or FiO2. Incidence of hypocapnia (PaCO2 < 4.5 kPa) was lower with VTV than PLV during the first day of life (32% vs. 62%; p < .01). Infants in the VTV‐group were more frequently extubated at 24 h (30% vs. 13%; p < .05). IVH Grade ≥3, BPD, and time on mechanical ventilation did not differ between the groups.

Conclusions

VTV is safe to apply in infants born at <26 GA and was observed to result in a lower incidence of hypocapnia compared to infants ventilated by PLV, without any differences in outcomes.
Sick to the stomach of the ranitidine shortage?
Authors: Motta Marco , Wilcock Mike
Published: February 2021

Patients and prescribers have recently been affected by interruptions to the supply of all formulations of the H2 antagonist ranitidine as a result of possible contamination with N‐nitrosodimethylamine. Here, Marco Motta and Mike Wilcock present the outcomes of their study evaluating the implications of these shortages for patients taking ranitidine from six GP practices in Cornwall.
School segregation of migrants and their descendants in a dual school system: The case of Barcelona
Authors: Bayona‐i‐Carrasco Jordi , Domingo Andreu
Published: February 2021

This study analyses levels of school segregation of students of immigrant origin in a city of the south of Europe, namely, Barcelona, which is characterised by a rapidly increasing growth of international immigration in recent decades and moderate or even low levels of residential segregation of immigrants. Besides its analysis of nationality and origin, its main contribution is that it explores a generational typology classifying students according to their place of birth, year of arrival and origin of progenitors, thus revealing different degrees of school segregation in keeping with each student's migratory history. Moreover, in the context of a dual school system (public and private), segregation is analysed by breaking it down in accordance with state or private ownership of the school. The results indicate a marked degree of segregation among students of the first generation and also among descendants of immigrants, showing how the dual school system is responsible for a significant part of the segregation, and that comparison of residential and school segregation always shows that the latter is greater.
A case‐study of the coupled ocean–atmosphere response to an oceanic diurnal warm layer
Authors: Brilouet Pierre‐Etienne , Redelsperger Jean‐Luc , Bouin Marie‐Noëlle , Couvreux Fleur , Lebeaupin Brossier Cindy
Published: February 2021

A modelling case‐study based on observations from the Dynamics of the Madden–Julian Oscillation field campaign is presented and discussed. It aims at investigating the ocean–atmosphere coupling and the marine atmospheric boundary‐layer structure over an oceanic diurnal warm layer. This case corresponds to the development of a diurnal warm layer characterized by a sea surface temperature diurnal cycle of ∼2°C. A 1D oceanic model with high vertical resolution is used to investigate the mechanisms responsible for the establishment and decay of the diurnal warm layer highlighting competing impact of the absorption of the solar radiation, the turbulent transport and the surface heat loss. An atmospheric large‐eddy simulation coupled to the 1D oceanic model is then presented and extensively evaluated against the numerous observations available for this case. The simulation is able to reproduce the surface fluxes and the main boundary‐layer structures. This study thus provides a case to investigate the ability of parametrizations to handle the ocean–atmosphere coupling and its impact on the atmospheric boundary layer.
Benchmark density functional theory calculations of 13C NMR chemical shifts of the natural antimalarial compounds with a new basis set 3z‐S
Authors: Semenov Valentin A. , Krivdin Leonid B.
Published: February 2021

The PBE0 functional in combination with a new highly economical triple zeta basis set 3z‐S was applied for the benchmark calculations of 13C NMR chemical shifts in a series of 16 plant and marine antimalarial natural products involving quinine, neoquassin ether, korundamine A, cycleanine, 10′‐hydroxyusambarensine, sarachine, matopensine, acantholactam, vertine, lobatin B, domesticulide B, bielschowskysin, oxojatrophadiene, jasplakinolide Q, ellagic acid, and trioxacarcin D. 13C NMR chemical shifts calculated with a new basis set 3z‐S demonstrated a markedly good agreement with available experimental data characterized with a corrected mean absolute error of about 2 ppm for the range of 200 ppm. The acceptable accuracy of 3z‐S when compared to larger basis sets, can be obtained at a reduced cost, which provides a prospective use of 3z‐S basis set for 13C NMR calculations in a wide series of natural products.
Analysis of the communication links between the AlSat‐1b satellite and the ground station: The impact of the Auto Tracking system on antenna pointing accuracy
Authors: Bekkar Djelloul Saiah Saiah , Bensikaddour Elhabib , Kaddouri Ali , Belbachir Redouane , Nasri Boualem , Baba Hamed Djamel Eddine
Published: February 2021

The communication links between a satellite and the Earth station (ES) are exposed to many impairments such as noise, rain, and atmospheric attenuations. They are also prone to loss such as those resulting from antenna pointing and polarization. The Algerian Earth Observation satellite AlSat‐1b is designed to accomplish its mission in S‐band (Telecommands and Telemetry) and X‐band (images) frequencies in low Earth orbit (LEO). The ground segment (GS) of this satellite, situated in Oran, Algeria, is based on the X/Y antenna mounting system with 7.3‐m dish diameter. This large reflector can cause antenna pointing errors. The Antenna Control Unit (ACU) implemented in this station can be configured with or without an AutoTrack system. In this work, operational tests and analysis of the different communication links between AlSat‐1b and the ground station are presented. The obtained results clearly show that the quality of the S‐band links can reliably and efficiently satisfy the requirements without the use of the AutoTrack. On the contrary, the use of AutoTrack is necessary in order to obtain an improved level of link quality in the X band.
Palladium Nitrosyl Complexes as Highly Versatile Catalysts for C−H/C−H Oxidative Coupling of Arenes: Application Area and Insight into Mechanism
Authors: Shishilov Oleg N. , Shamsiev Ravshan S. , Akhmadullina Nailya S. , Flid Vitaly R.
Published: February 2021

Palladium nitrsosyl carboxylates Pd3(NO)2(CX3CO2)4(ArH)2 (I: X=Cl, Ar=Ph; II: X=F, Ar=Tol) are found to be effective catalysts for C−H/C−H oxidative homocoupling of arenes bearing electron‐donor as well as electron‐withdrawing groups (EWG). Trifluoroacetate complex II is found to be more promising due to higher stability under the reaction conditions. Complex II also shows high performance in intramolecular coupling in diarylsulfides, diarylethers and diarylamines giving corresponding dibenzothiophenes, dibenzofurans and carbazoles with yields ranged from moderate to high. The plausible mechanism is studied by DFT computational analysis basing on Pd3 linear complexes as major active species. It was found that two deprotonation steps proceed in two different ways: for the first deprotonation SEAr is most probable pathway while for the second one concerted metalation‐deprotonation (CMD) is preferable. That can explain high tolerance of the system to different substrates: SEAr is favorable in the presence of electron donor group and EWG facilitate CMD. NO group was found to be involved into the CMD pathway and that is the rate‐determining step with the highest activation barrier.
Visible‐Light‐Induced C‐P‐Bond Formation Using Reduced Graphene Oxide Decorated with Copper Oxide/Zinc Oxide (rGO/CuO/ZnO) as Ternary Recyclable Nanophotocatalyst
Authors: Firoozi Somayeh , Hosseini‐Sarvari Mona
Published: February 2021

The reduced graphene oxide and copper oxide loaded on zinc oxide (rGO/CuO/ZnO) was successfully synthesized, fully characterized, and applied as a highly efficient reusable nano photocatalyst for the synthesis of aryl phosphonate derivatives starting from trialkyl phosphites and arylhydrazines in the presence of visible light radiation at room temperature in the air atmosphere under eco‐friendly and very mild reaction conditions without using base, oxidant, additive or ligand. Moreover, this strategy is the first report of the use of rGO/CuO/ZnO ternary nanocomposite as heterogeneous photocatalyst in organic synthesis.
Sustainable Synthesis, NMR and Computational Study of Isobutylmesitylphosphine
Authors: Gafurov Zufar N. , Zueva Ekaterina M. , Yakhvarov Dmitry G.
Published: February 2021

The alkyl‐aryl‐substituted secondary phosphines i‐Bu(Mes)PH and Cy(Mes)PH are obtained from the reaction of the electrochemically generated organonickel sigma‐complex [NiBr(Mes)(bpy)] (Mes=2,4,6‐trimethylphenyl; bpy=2,2′‐bipyridine) with primary phosphines i‐BuPH2 and CyPH2, respectively. Detailed multinuclear NMR spectroscopy and quantum‐chemical calculations were used to assign the diastereotopic protons of i‐Bu(Mes)PH.
Oxygen‐Bridged Triphenylamine Units Tuning the Photophysical Properties of Classical Phosphorescent Iridium(III) Complex
Authors: Cao Yibo , Song Jialiang , Li Gang , Zheng Ying , Shi Chao , Li Qiuxia , Yuan Aihua
Published: February 2021

A new yellow phosphorescent iridium(III) complex Ir(ppybop)2acac with two oxygen‐bridged triphenylamine units were prepared and investigated. The cyclometalating ligand ppybop was synthesized by the efficient Suzuki‐Miyaura cross‐coupling reaction of oxygen‐bridged triarylamine unit based boron reagent 1‐a and 2‐(4‐Bromophenyl)pyridine, and the acetylacetone (acac) was used as an auxiliary ligand. Notably, the complex Ir(ppybop)2acac measured with a fluorescence spectrophotometer can show a larger redshift emission (λem=568 nm), a narrower full width at half maximum (FWHM=59 nm), a longer emission lifetime (τ[b]=3127 ns) and a better solubility in comparison with the classical green complex Ir(ppy)2acac (λem=520 nm, FWHM=70 nm, τ[b]=1206 ns). In addition, the DFT calculation results indicate that the strong electron‐donating ability of the unit can lead to the unusual ligand‐to‐metal charge transfer (3LMCT) excited state characteristics of Ir(ppybop)2acac, which is completely different from the metal‐to‐ligand charge transfer (3MLCT) in Ir(ppy)2acac. This result can provide a new strategy for the design of new phosphorescent iridium(III) complexes.
S‐Denitrosylation by the C‐Terminal Swinging Arm of R1 Subunit: A Novel Mechanism to Restore Ribonucleotide Reductase Activity
Authors: Sengupta Rajib , Coppo Lucia , Sircar Esha , Mishra Pradeep , Holmgren Arne
Published: February 2021

Thioredoxin (Trx) system plays a crucial role as an electron donor for ribonucleotide reductase (RNR), which catalyzes the formation of deoxyribonucleotides for DNA synthesis. Here, we show that the S‐nitrosylation of the R1 subunit inhibits RNR catalysis and that the enzyme activity is restored via denitrosylation mediated by shuttle dithiols (in a CXXC motif) of the R1 C‐terminal tail or by an externally supplied R1 C‐terminal peptide (containing vicinal dithiols), in case of a R1 C‐terminal mutant. The Trx system was found to be necessary for regeneration of the oxidized vicinal dithiols in the C‐terminal tail/peptide. Our results with recombinant RNR highlighted the importance of C‐terminal vicinal dithiols of R1, in regenerating the RNR activity of S‐nitrosylated R1 subunits. This study will contribute towards a better understanding of S‐(de)nitrosylation mediated regulation of RNR activity.
Separation of power and expertise: Evidence of the tyranny of experts in Sweden's COVID‐19 responses
Authors: Bylund Per L. , Packard Mark D.
Published: February 2021

Whereas most countries in the COVID‐19 pandemic imposed shutdowns and curfews to mitigate the contagion, Sweden uniquely pursued a more voluntarist approach. In this article, our interest is primarily on how and why Sweden's approach to the pandemic was so unique. There are two parts to this research question: (1) why did virtually all other nations follow a radical lockdown protocol despite limited evidence to its effectiveness and (2) why did Sweden not follow this same protocol despite strong political pressures? The answers to these questions lie within typical government technocracy versus Sweden's constitutional separation of government and technocracy. We review the history of the responses to the pandemic and show how the “tyranny of experts” was severe within the typical technocratic policy response, and attenuated in Sweden's. Thus, the recent pandemic offers empirical evidence and insights regarding the role of Hayekian knowledge problems in engendering a technocratic “tyranny of experts” and how such effects can be structurally mitigated.
Systematic review of features for co‐simulating security incidents in Cyber‐Physical Systems
Authors: Czekster Ricardo M. , Morisset Charles , Clark John A. , Soudjani Sadegh , Patsios Charalampos , Davison Peter
Published: February 2021

Cyber‐Physical Systems (CPS) and Internet‐of‐Things (IoT) plus energy are the enabling technology of modern power systems also known as the Smart Grid (SG). A SG may consist of thousands of interconnected components communicating and exchanging data across layers that stretch beyond technical capabilities, for instance, markets and customer interactions. Cyber‐physical security is a major source of concern due to the high reliance of the SG on Information and Communication Technologies (ICT) and their widespread use. Addressing security requires developing modeling and simulation tools that approximate and replicate adversarial behavior in the SG. These tools have in fact two simulators, one handling continuous power flows and another for capturing the discrete behavior when communicating across CPS or IoT components. The technique of composing two models of computation in a global simulation of these coupled systems is called co‐simulation. Although there are many frameworks and tools for co‐simulation, the set of features for modeling cyber‐physical security incidents in the SG lacks thorough understanding. We present a systematic review of features and tools for co‐simulating these concerns in CPS. We also highlight and discuss research gaps with respect to the most used tools in industry and academia and comment on their relevant features.
Emergent Bilinguals’ Use of Word Prediction Software Amid Digital Composing
Authors: Brown Sally , Allmond Alexandra
Published: February 2021

Composing is an essential part of literacy development in early childhood classrooms, and writing experiences are continually changing through advances in technology. Writing in a new language can be particularly challenging for emergent bilinguals as they navigate learning how to spell in English as part of the writing process. New pedagogical tools must be used to support these students as meaning makers and composers. In this study, we investigated how a group of first‐grade emergent bilinguals used word prediction software as they created digital compositions over the course of a year. The results suggest several positive ways, such as basic spelling support, extended written responses, and additional opportunities to practice reading, that this digital tool enhanced the meaning‐making process of emergent bilingual writers. Recommendations for educators to implement word prediction software in classrooms are included.
Clinical reasoning in canine vestibular syndrome: Which presenting factors are important?
Authors: Harrison Eleanor , Grapes Nick J. , Volk Holger A. , De Decker Steven
Published: February 2021

Background: Although the use of clinical reasoning has been evaluated for several neurological presentations, this approach has not yet been investigated for dogs with vestibular syndrome.

Methods: Two hundred and thirty‐nine dogs presenting with vestibular syndrome were included in this retrospective study. Univariate analysis of variables (clinical history, signalment, clinical presentation and neurological examination findings) was performed. Variables with p < 0.3 were selected for logistic regression.

Results: Ninety‐five percent of dogs were represented by eight conditions: idiopathic vestibular disease (n = 78 dogs), otitis media interna (n = 54), meningoencephalitis of unknown origin (n = 35), brain neoplasia (n = 26), ischaemic infarct (n = 25), intracranial empyema (n = 4), metronidazole toxicity (n = 3) and neoplasia affecting the middle ear (n = 3). Idiopathic vestibular disease was associated with higher age, higher bodyweight, improving clinical signs, pathological nystagmus, facial nerve paresis, absence of Horner's syndrome and a peripheral localisation. Otitis media interna was associated with younger age, male gender, Horner's syndrome, a peripheral localisation and a history of otitis externa. Ischaemic infarct was associated with older age, peracute onset of signs, absence of strabismus and a central localisation.

Conclusions: Discrete clinical features can be used to identify the most likely diagnosis in dogs with vestibular syndrome.
Is veterinary work more than satisfying? A critical review of the literature
Authors: Clise Madeleine H. , Kirby Neil , McArthur Michelle L.
Published: February 2021

Despite the rise of positive psychology in recent times, research continues to emphasise the risks and negative outcomes associated with veterinary work. Understanding these challenges and risks is imperative in helping those affected and preventing or limiting exposure for future veterinarians. However, it is vital that positive factors associated with their well‐being are concomitantly addressed. Drawing on an organisational psychology perspective and associated theories, this review critically analyses the literature on veterinary well‐being, job satisfaction and the role of positive emotions at work. This perspective prompts a call to researchers to investigate the positive aspects of veterinary work and offers many suggestions for future research and associated implications. Drawing on an extensive evidence base of research pertaining to positive emotions and well‐being in veterinarians, the development, implementation and validation of workplace interventions should follow. The veterinary profession is a highly rewarding one and a focus on pleasure in veterinary work and ways to encourage this, will only help veterinarians flourish and help to promote the profession in the way it deserves.
Hypoxaemia and bradyarrhythmia in a foal undergoing surgical bladder repair
Authors: Petruccione Ilaria , Levionnois Olivier , Pawson Patricia
Published: February 2021

A five‐day‐old female Thoroughbred foal was diagnosed with uroperitoneum and ruptured bladder. Prior to general anaesthesia mild hyperkalaemia (5.2 mmol L−1) and respiratory distress were noticed. Under general anaesthesia urine was drained rapidly by free flow through an abdominal incision. During abdominal drainage heart rate declined from 80 to 40 beats per minute and atrial standstill was suspected on the electrocardiogram. Arterial blood gas analysis revealed worsening hyperkalaemia (6 mmol L−1) and severe hypoxaemia (PaO231 mmHg). Calcium gluconate, 23% 4 mg kg−1diluted 1:4 with sodium chloride 0.9%, was administer over 20 minutes to restoring the resting membrane potential. To treat hypoxaemia, mechanical ventilation was started and salbutamol 100 μg was administered through the endotracheal tube. Atrial standstill resolved and heart rate increased. General anaesthesia ended without further complications. Careful pre‐operative preparation is required in foals with uroperitoneum to avoid the exacerbation of relatively mild alterations in electrolyte balance.
Review on publicly available datasets for educational data mining
Authors: Mihaescu Marian Cristian , Popescu Paul Stefan
Published: February 2021

The availability of a dataset represents a critical component in educational data mining (EDM) pipelines. Once the dataset is at hand, the next steps within the research methodology regard proper research issue formulation, data analysis pipeline design and implementation and, finally, presentation of validation results. As the EDM research area is continuously growing due to the increasing number of available tools and technologies, one of the critical issues that constitute a bottleneck regards a properly documented review on publicly available datasets. This paper aims to present a succinct, yet informative, description of the most used publicly available data sources along with their associated EDM tasks, used algorithms, experimental results and main findings. We have found that there are three types of data sources: well‐known data sources, datasets used in EDM competitions and standalone EDM datasets. We conclude that the success of the future of EDM data sources will rely on their ability to manage proposed approaches and their experimental results as a dashboard of benchmarked runs. Under these circumstances, the reproducibility of data analysis pipelines and benchmarking of proposed algorithms becomes at hand for the research community such that progress in the EDM domain may be much more easily acquired. The most crucial outcome regards the possibility of continuously improving existing data analysis pipelines by tackling EDM tasks that rely on publicly available datasets and benchmarking data analysis pipelines that use open‐source implementations.

This article is categorized under:

Application Areas > Education and Learning

Fundamental Concepts of Data and Knowledge > Big Data Mining
Effects of age on sperm quality metrics in endangered Mississippi gopher frogs (Lithobates sevosus) from captive populations used for controlled propagation and reintroduction efforts
Authors: Watt Ashley M. , Marcec‐Greaves Ruth , Hinkson Kristin M. , Poo Sinlan , Roberts Beth , Pitcher Trevor E.
Published: February 2021

A decline in sperm quality with age is a common prediction of senescence‐based hypotheses and empirical studies. While widely studied across taxa, there is little known on the effect of ageing on sperm quality in amphibians, especially in captive populations used for controlled propagation and reintroduction efforts. Here, we investigated variation in sperm quality metrics (i.e., motility, concentration, and morphology) in the endangered Mississippi gopher frog (Lithobates sevosus) among males of three age categories using individuals from captive breeding populations housed at three different zoological institutions. Different aged males across the species expectant lifespan (1–9, 1–2, 3–4, and 8–9‐year‐old subcategories) were chosen in an attempt to identify an optimal breeding age relevant for captive breeding programs. Moreover, we explored and statistically controlled for potential differences in sperm quality which may be attributed to the type of induction hormones and source populations that differed among institutions. Results indicated that males of different ages did not differ in sperm motility or concentration. However, we did find that older males (8–9 years old) had significantly longer sperm than other age categories and younger males (1–2 years old) had significantly more atypical sperm than other age categories. Furthermore, we found no significant differences in any sperm quality metrics between the different induction hormones or source populations used at the different institutions. Within a captive breeding program, this information is especially valuable as our results indicate that males that have only recently sexually matured may not be ready to breed, while older males maintain sperm quality metrics presumably related to fertilization success.
Alternative derivation of the higher-order constitutive model for six-parameter elastic shells
Authors: Bîrsan Mircea
Published: February 2021

In this paper, we present a general method to derive the explicit constitutive relations for isotropic elastic 6-parameter shells made from a Cosserat material. The dimensional reduction procedure extends the methods of the classical shell theory to the case of Cosserat shells. Starting from the three-dimensional Cosserat parent model, we perform the integration over the thickness and obtain a consistent shell model of order $$ O(h^5) $$

O
(

h
5

)

with respect to the shell thickness h. We derive the explicit form of the strain energy density for 6-parameter (Cosserat) shells, in which the constitutive coefficients are expressed in terms of the three-dimensional elasticity constants and depend on the initial curvature of the shell. The obtained form of the shell strain energy density is compared with other previous variants from the literature, and the advantages of our constitutive model are discussed.
Use of 450-808 nm diode lasers for efficient energy absorption during powder bed fusion of Ti6Al4V
Authors: Alsaddah Mohammed , Khan Ashfaq , Groom Kristian , Mumtaz Kamran
Published: February 2021

The additive manufacturing process selective laser melting (SLM) uses a powder bed fusion approach to fully melt layers of powdered metal and create 3D components. Current SLM systems are equipped with either single or multiple (up to four) high-power galvo-scanning infrared fibre laser sources operating at a fixed wavelength of 1064 nm. At this wavelength, a limited laser energy absorption takes place for most metals (e.g. alloys of aluminium have less than 10% absorption and titanium 50-60% absorption). The lower absorption of 1064-nm laser sources requires higher laser powers to compensate for the loss of energy due to reflectivity and fully melt the feedstock material. This makes the use of 1064-nm lasers within current powder bed fusion SLM systems energy inefficient. Further to this, there is limited potential for scale-up of these laser sources within an SLM system architecture due to physical space requirements and high economic cost, placing further limitations on current state-of-the-art SLM productivity. This research investigates the use of low power, highly scalable fibre coupled diode laser sources and the influence of shorter laser wavelengths (450–808 nm) on material absorption and processing efficiency using a diode area melting (DAM) approach. It was found that when processing Ti6Al4V, absorption was 11% higher using 450-nm lasers when compared to using 808-nm lasers and 14% higher than 1064-nm lasers. The maximum powder bed temperature for irradiation at 450 nm and 808 nm was 1920 0C and 1760 0C respectively when using only 3.5 W of laser power. Due to the speed at which the DAM process scans the powder bed, the melt pool cooling rate was much slower (750–1400 0C/s) than traditional SLM (105–106 0C/s). This encouraged the development of β phases within the formed Ti6Al4V component. The low power, low cost, highly compact short wavelength diode laser is viable energy source for future powder bed fusion additive manufacturing systems, with potential for productivity scale-up using a DAM methodology.
A quantitative approach for debris flow inception and propagation analysis in the lead up to risk management
Authors: Ciurleo Mariantonietta , Mandaglio Maria Clorinda , Moraci Nicola
Published: February 2021

This paper presents a quantitative analysis of debris flows in weathered gneiss through a methodology to identify key aspects in the lead up to risk management. The proposed methodology considers both the triggering and propagation stages of landslide using two physically based models “Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Analysis” (TRIGRS) and “Smoothed Particle Hydrodynamics” (SPH), respectively. The TRIGRS analyses provided information about the location and initial volume of potential landslides. The SPH model, adopting the initial triggering volumes as input data, allowed the back analysis of the propagation stage in terms of both main pathway and depositional area. Both models can be easily implemented over large areas for risk assessment and are able to provide interesting information for the design of risk mitigation structures. Clearly, the rigorous implementation of these models requires the use of geotechnical data obtained from in situ and laboratory tests. When these data are not available, literature data obtained for similar soils for genesis and stress history with those studied can be used. The applicability of the methodology has been tested on two debris flows which occurred in 2001 and 2005 in the province of Reggio Calabria causing extensive damage involving various lifelines. The model results have been validated with the real events, in terms of both triggering/inception areas and debris fans using two dimensionless indices (Itrig and Idep). The indices compared, respectively, the real triggering/inception area with the simulated one and the real depositional area with the numerical one. For analysed phenomena, the values of Itrig were higher than 90% while Idep assumes values higher than 70% which support the applicability of the proposed methodology.
Składnica: a constituency treebank of Polish harmonised with the Walenty valency dictionary
Authors: Woliński Marcin , Hajnicz Elżbieta
Published: February 2021

This paper reports on the developments in three interrelated linguistic resources for Polish. The first is Świgra 2—a rule based constituency parser for Polish. The second is Składnica—a treebank built using Świgra 2. The third resource is valency dictionary Walenty, which became available when the work on the first two was already advanced. However, since the dictionary is much more comprehensive than the ad-hoc dictionary used previously with Świgra, a decision was made to switch the parser and the treebank to the new dictionary. The switch required several modifications to the Świgra 2 parser, including implementation of unlike coordination, introducing semantically motivated phrases, and non-standard case values. A semi-automated procedure to upgrade previously disambiguated trees in Składnica was required as well. Modifications introduced in the treebank during the upgrade included systematic changes of notation and resolving newly introduced ambiguities resulting from the use of the more detailed distinctions made in the dictionary. The procedure for confronting Składnica with the trees generated with the new version of the Świgra 2 parser using the Walenty dictionary allowed us to check all of these resources for consistency. This resulted in several corrections being introduced in both the treebank and the valency dictionary.
Laser interstitial thermotherapy (LITT) for the treatment of tumors of the brain and spine: a brief review
Authors: Chen Clark , Lee Ian , Tatsui Claudio , Elder Theresa , Sloan Andrew E.
Published: February 2021

Introduction

Laser Interstitial Thermotherapy (LITT; also known as Stereotactic Laser Ablation or SLA), is a minimally invasive treatment modality that has recently gained prominence in the treatment of malignant primary and metastatic brain tumors and radiation necrosis and studies for treatment of spinal metastasis has recently been reported.

Methods

Here we provide a brief literature review of the various contemporary uses for LITT and their reported outcomes.

Results

Historically, the primary indication for LITT has been for the treatment of recurrent glioblastoma (GBM). However, indications have continued to expand and now include gliomas of different grades, brain metastasis (BM), radiation necrosis (RN), other types of brain tumors as well as spine metastasis. LITT is emerging as a safe, reliable, minimally invasive clinical approach, particularly for deep seated, focal malignant brain tumors and radiation necrosis. The role of LITT for treatment of other types of tumors of the brain and for spine tumors appears to be evolving at a small number of centers. While the technology appears to be safe and increasingly utilized, there have been few prospective clinical trials and most published studies combine different pathologies in the same report.

Conclusion

Well-designed prospective trials will be required to firmly establish the role of LITT in the treatment of lesions of the brain and spine.
Environmental exposomics and lung cancer risk assessment in the Philadelphia metropolitan area using ZIP code–level hazard indices
Authors: McKeon Thomas P. , Hwang Wei-Ting , Ding Zhuoran , Tam Vicky , Wileyto Paul , Glanz Karen , Penning Trevor M.
Published: February 2021

To illustrate methods for assessing environmental exposures associated with lung cancer risk, we investigated anthropogenic based air pollutant data in a major metropolitan area using United States-Environmental Protection Agency (US-EPA) Toxic Release Inventory (TRI) (1987–2017), and PM2.5 (1998–2016) and NO2 (1996–2012) concentrations from NASA satellite data. We studied chemicals reported according to the following five exposome features: (1) International Agency for Research on Cancer (IARC) cancer grouping; (2) priority EPA polycyclic aromatic hydrocarbons (PAHs); (3) component of diesel exhaust; (4) status as a volatile organic compound (VOC); and (5) evidence of lung carcinogenesis. Published articles from PubChem were tallied for occurrences of 10 key characteristics of cancer-causing agents on those chemicals. Zone Improvement Plan (ZIP) codes with higher exposures were identified in two ways: (1) combined mean exposure from all features, and (2) hazard index derived through a multi-step multi-criteria decision analysis (MMCDA) process. VOCs, IARC Group 1 carcinogens consisted 82.3% and 11.5% of the reported TRI emissions, respectively. ZIP codes along major highways tended to have greater exposure. The MMCDA approach yielded hazard indices based on imputed toxicity, occurrence, and persistence for risk assessment. Despite many studies describing environmental exposures and lung cancer risk, this study develops a method to integrate these exposures into population-based exposure estimates that could be incorporated into future lung cancer screening trials and benefit public health surveillance of lung cancer incidence. Our methodology may be applied to probe other hazardous exposures for other cancers.
Effect of SARS-CoV-2 (COVID-19) Pandemic and Lockdown on Body Weight, Maladaptive Eating Habits, Anxiety, and Depression in a Bariatric Surgery Waiting List Cohort
Authors: Albert Umberto , Losurdo Pasquale , Leschiutta Alessia , Macchi Serena , Samardzic Natasa , Casaganda Biagio , de Manzini Nicolò , Palmisano Silvia
Published: February 2021

Purpose

On January 30, 2020, the World Health Organization declared COVID-19 as a “public health emergency of international concern.” The primary aim of the study was to evaluate weight and food habit changes during COVID-19 outbreak. The secondary endpoint was to explore the psychological factors, arising during the pandemic, influencing weight and dietary variations.

Materials and Methods

A survey composed of four different items was conducted by telephone interview: (1) anthropometric data and type of procedure, (2) Hospital Anxiety and Depression Scale (HADS), (3) maladaptive eating behaviors, and (4) personal feelings moved by the COVID-19 spread and lockdown.

Results

Fifty-six patients were enrolled. No significant changes in weight, BMI, and maladaptive eating habits were observed. A significant reduction in the anxiety index score was observed. In 17.8% of cases, a change in obesity class was reported, and among these patients, a substantial modification in bariatric procedures was planned (60%).

Conclusion

This study showed no effect on weight and BMI nor on rates of maladaptive eating habits associated with quarantine/social isolation among severely obese individuals waiting for the bariatric surgery. At the end of lockdown, a considerable proportion of patients modified their initial obesity class, and in selected cases, it could represent a criteria for rearrangement of the planned bariatric procedure. In obese patients, the lockdown and social distancing generated a reduction of fear of confronting and being negatively judged by others. This psychological aspect was assessed with the reduction of the HADS score.
Lockdown measures and air quality: evidence from Italian provinces
Authors: Malpede Maurizio , Percoco Marco
Published: February 2021

The aim of this short communication is to estimate the effects of the implementation of more restrictive lockdown measures on pollution levels in Italy. Using a time series of weekly concentrations of PM10, PM2.5 and NO2 for the period 2016–2020 across 71 provinces, we find that the introduction of lockdown measures reduced the air concentration levels of PM10 and NO2 by 17–18%, while their effect on PM2.5 remains unclear. These results indicate that the lockdown had a significant positive impact in terms of lives saved and improved air quality.
Hereditary diseases and child wish: exploring motives, considerations, and the (joint) decision-making process of genetically at-risk couples
Authors: Severijns Y. , de Die-Smulders C. E. M. , Gültzow T. , de Vries H. , van Osch L. A. D. M.
Published: February 2021

Couples who are at risk of transmitting a genetic disease to their offspring may face difficult challenges regarding reproductive decision-making. Deciding if, and how, to purse their child wish can be a demanding process. This study aims to describe the reproductive joint decision-making process of genetically at-risk couples. A qualitative study was conducted with 16 couples (N=31) at risk of transmitting a genetic disease to their offspring and who received genetic counseling. Most couples were not aware of all available reproductive options in the Netherlands. A variety of motives was reported with almost all couples expressing a preference towards a reproductive option in which the child is genetically related to both parents. Only a few couples considered other options such as the use of donor gametes, adoption, and foster parenting. All couples indicated that they had multiple conversations to reach a mutually supported reproductive decision. Several carriers reported feelings of guilt and in some couples, the woman appeared to have a greater impact in the decision-making process as she should carry a pregnancy and should undergo medical treatments. This study provides insight in the extensive decision-making process of genetically at-risk couples and the role of both partners in this process. These findings can guide the development of genetic counseling (e.g., increase awareness of available reproductive options) and decision support for these couples.
Shedding light on autistic traits in struggling learners: A blind spot in medical education
Authors: Giroux Marie , Pélissier-Simard Luce
Published: February 2021

Some highly challenging, seemingly “unsolvable” situations that arise in medical education could be the result of autistic traits (AT) in learners. AT exist in physicians and learners, ranging from profiles compatible with DSM-5’s criteria for autism spectrum disorder (ASD) to more subtle manifestations of ASD’s “broader phenotype.” Often associated with strengths and talents, AT may nonetheless pose significant challenges for learning, teaching, and practising medicine. Since AT remain widely under-recognized and misunderstood by educators, clinicians, and affected individuals alike, they represent a blind spot in medical education. The use of a “neurodiversity lens” to examine challenging situations may help educators consider different pedagogical approaches to address those potentially stemming from AT.

This paper aims to raise awareness and understanding of AT-related difficulties in struggling medical learners. To overcome the blind spot challenge and help develop this “neurodiversity lens,” we explore different angles. Beyond any diagnostic consideration, we offer a series of contextual examples, paralleled with explanatory concepts from the field of ASD. We also underline the role of context on functional impact and describe the often ill-defined pattern of challenges encountered, as well as the fertile grounds for interpersonal misunderstandings and disrespect. We propose historical, cultural, and clinical reasons likely contributing to the blind spot. Mindful of the potential risks of prejudice associated with identifying AT-related difficulties, we underline the necessity and feasibility of conciliating diversity and dignity with accountability standards for medical competence.
MXenes for Solar Cells
Authors: Yin Lujie , Li Yingtao , Yao Xincheng , Wang Yanzhou , Jia Lin , Liu Qiming , Li Junshuai , Li Yali , He Deyan
Published: February 2021

Application of two-dimensional MXene materials in photovoltaics has attracted increasing attention since the first report in 2018 due to their metallic electrical conductivity, high carrier mobility, excellent transparency, tunable work function and superior mechanical property. In this review, all developments and applications of the Ti3C2Tx MXene (here, it is noteworthy that there are still no reports on other MXenes’ application in photovoltaics by far) as additive, electrode and hole/electron transport layer in solar cells are detailedly summarized, and meanwhile, the problems existing in the related studies are also discussed. In view of these problems, some suggestions are given for pushing exploration of the MXenes’ application in solar cells. It is believed that this review can provide a comprehensive and deep understanding into the research status and, moreover, helps widen a new situation for the study of MXenes in photovoltaics.
Soliton resolution for the focusing modified KdV equation
Authors: Chen Gong , Liu Jiaqi
Published: February 2021

The soliton resolution for the focusing modified Korteweg–de Vries (mKdV) equation is established for initial conditions in some weighted Sobolev spaces. Our approach is based on the nonlinear steepest descent method and its reformulation through

\bar \partial

-derivatives. From the view of stationary points, we give precise asymptotic formulas along trajectory

x = {\mathrm{v}}t

for any fixed v. To extend the asymptotics to solutions with initial data in low regularity spaces, we apply a global approximation via PDE techniques. As by-products of our long-time asymptotics, we also obtain the asymptotic stability of nonlinear structures involving solitons and breathers.