bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical study of energy, inertia and nullity of phenylene and anthracene
Authors: Ahmad Zaheer , Mufti Zeeshan Saleem , Nadeem Muhammad Faisal , Shaker Hani , Siddiqui Hafiz Muhammad Afzal
Published: May 2021

Energy of a molecule plays an important role in physics, chemistry and biology. In mathematics, the concept of energy is used in graph theory to help other subjects such as chemistry and physics. In graph theory, nullity is the number of zeros extracted from the characteristic polynomials obtained from the adjacency matrix, and inertia represents the positive and negative eigenvalues of the adjacency matrix. Energy is the sum of the absolute eigenvalues of its adjacency matrix. In this study, the inertia, nullity and signature of the aforementioned structures have been discussed.
Respiratory decompensation due to COVID-19 requiring postpartum extracorporeal membrane oxygenation
Authors: Willson Stephanie F. , DuBois Richard , Short Briana , Agerstrand Cara , Skupski Daniel , Dayal Ashlesha K.
Published: May 2021

Objectives

The Coronavirus disease 2019 (COVID-19) pandemic has rapidly spread since its emergence in December 2019, and has been associated with severe morbidity and mortality. This report includes an in-depth discussion on the unique challenges that the obstetrical population provides when considering optimal management strategy.

Case presentation

We describe our approach to a preterm patient with high clinical suspicion for COVID-19 whose condition turned critical in the postpartum state.

Conclusions

Differences in physiology during pregnancy, and goals for reducing both maternal and fetal risks, provide challenges when considering intensive care management, delivery timing, and method of delivery.
Differences between retort distillation and double distillation in cherry spirits with double-kettle equipment
Authors: Zhang Jiang , Zhao Xinjie , Qin Weishuai , Zhang Xiang , Ma Zhansheng , Sun Yuxia
Published: May 2021

The effects of retort distillation (RD) and double distillation (DD) for producing cherry spirits using unique double-kettle equipment were compared, for the first time. RD improved distillation efficiency and kept methanol at a safe level. Compared with DD, the contents of higher alcohols increased with RD: isobutanol, propanol, and benzyl alcohol increased by 15.5, 32.9, and 37.9%, respectively, with the content of ethyl esters being reduced. In contrast, isoamyl formate, with its cherry aroma, was not detected in DD spirits, but was present at up to 10.71 mgL−1 in RD spirits. Six terpenoids were detected in RD spirits, but only four in DD spirits. These changes were also reflected in the sensory scores. Although the purity and elegance of the RD spirits decreased, their complication, richness, and honey aroma increased. These changes are very important for guaranteeing spirits quality, providing a reference for research and production of cherry distilled spirits.
Design and Preparation of Magnetism-Driven Intelligent Hydrogel Actuators
Authors: Chang Y.-J. , Zhou Q. , Hou W.-H. , Liang Y.-H. , Ren L. , Sun D.-H. , Ren L.-Q.
Published: May 2021

Novel kinds of magnetism-driven poly N,N-dimethylacrylamide bilayer intelligent hydrogels with various nanofibrillated cellulose (NFC) contents were prepared successfully via one-step insitu free radical polymerization. The bilayer hydrogels possessed high mechanical strength, efficient swelling and steady magnetic response. With the increase of nanofibrillated cellulose content, the crosslinking density of the hydrogels increased, leading to the decrease of swelling rate and increase of mechanical strength and swelling bending degree of hydrogel actuators, respectively. Fe3O4 particles existed tightly on the micropore surfaces of the hydrogels, which built the function base of magnetic response of hydrogel actuators. The addition of Fe3O4 was irrelevant to the variation of crosslinking density. The bilayer structure exhibited high bonding strength. Based on intelligent responsive properties, bilayer hydrogels were designed as soft magnetism-driven actuators, realizing capture and transportation properties and provided material candidates for soft robots.
Extraction, Treatment and Applications of Natural Fibers for Bio-Composites – A Critical Review
Authors: Sathish S. , Prabhu L. , Gokulkumar S. , Karthi N. , Balaji D. , Vigneshkumar N.
Published: May 2021

Nowadays, sustainable and eco-friendly products are gaining more attention in various engineering industries owing to their considerable strength-to-weight ratio, abundant availability, and recyclability. The properties of biofibers depend on the cultivation method, environmental conditions, and extraction method. Biofibers are hauled out by dew retting, water retting, and mechanical decortication methods. The properties of natural fiber–reinforced composites can be enhanced by proper physical and chemical treatments. The aim of this study is to propose a complete evaluation of the different extraction methods applied on natural fibers. Various physical and chemical treatment methods were used to ascertain the properties of optimized natural fiber-reinforced composites for various industrial applications. The key findings derived from various existing data and the chemical treatment results of the biofiber-reinforced composite are specifically highlighted with critical assessment. The properties and use of natural fiber-reinforced composites in the various fields of applications have made them candidates of choice over synthetic petroleum–based fibers.
Robust synchronization of chaotic fractional-order systems with shifted Chebyshev spectral collocation method
Authors: Owolabi Kolade M.
Published: May 2021

In this work, synchronization of fractional dynamics of chaotic system is presented. The suggested dynamics is governed by a system of fractional differential equations, where the fractional derivative operator is modeled by the novel Caputo operator. The nature of fractional dynamical system is non-local which often rules out a closed-form solution. As a result, an efficient numerical method based on shifted Chebychev spectral collocation method is proposed. The error and convergence analysis of this scheme is also given. Numerical results are given for different values of fractional order and other parameters when applied to solve chaotic system, to address any points or queries that may occur naturally.
A comparative study of chemical constituents and safety of Thai herbal medicated oil formula and traditional medicated oil
Authors: Booncharoen Poorada , Boonchai Waranya , Akarasereenont Pravit , Tripatara Pinpat
Published: May 2021

Objectives

Medicated oil has been traditionally used as an analgesic medicine to relieve pain by applying to the skin over painful muscles, and has been established in The National List of Essential Medicines (2556 B.E.). Traditional Medicated oil (TMO) consists of cassumunar ginger, Wan En Lueang, and Wan Ron Thong. It is prepared by frying herbs in coconut oil which is a traditional method. Thai Herbal Medicated oil formula (MOF) comprises cassumunar ginger, sweet flag, lesser galangal, wild turmeric, Wan En Lueang, and Wan Ron Thong. Its preparation by maceration with methyl salicylate is modified method to avoid the heat in the traditional preparation. Since both recipes have different methods of extraction and compositions, it is necessary to determine the chemical constituents and acute skin irritation potential of MOF and TMO.

Methods

This study applied Gas Chromatography-Mass Spectrometry (GC-MS) for quality assessment of MOF extract and TMO extract. The mass spectra of the compounds matched with authentic standards from the NIST library. The compounds were identified by comparing their retention time and peak area, and the percentage of matched factor was more than 80%. The safety assessment on acute skin irritation used the 4 h human patch test (4 h HPT) in 36 healthy subjects.

Results

The 37 compounds were found in MOF extract. The most common chemical constituents were terpene derivatives; monoterpenes and sesquiterpenes, and others, namely benzene derivatives, ester, phenylpropanoid, and other compounds. The 33 compounds were found in TMO extract and the chemical groups were similar to MOF extract. The 4 h HPT demonstrated that the MOF extract, TMO extract, methyl salicylate solvent, and coconut oil solvent, did not induce skin irritation. However, the vehicle of the formulae and the whole formulae as MOF and TMO clinically induced skin irritation and accorded with rubefacient. The characteristic as mild erythema or dryness, but not erythema with edema, could appear after the use of rubbing skin products.

Conclusions

The chemical constituents found in MOF and TMO extracts were partially different and their acute skin irritation reactions were not significantly different. A study on the efficacy of both remedies should be performed in the future, as well as a study on active chemical constituents. This study provides scientific evidences of quality and safety, including GC-MS condition for poly-herbal medicated oil standardization.
The crystal structure of 1,2-bis(4-pyridyl)ethane - 4,4-dihydroxydiphenylmethane (1/1), C25H21N2O2
Authors: Cheng Jie , Chen Jue
Published: May 2021

C25H21N2O2, monoclinic, C2/c (no. 15), a = 11.041(2) Å, b = 7.859(2) Å, c = 24.131(5) Å, β = 95.26(3)°, V = 2085.1(7) Å3, Z = 4, R

gt
(F) = 0.0486, wR

ref
(F
2) = 0.1402, T = 295 K.
Crystal structure of 1-cyclopropyl-7-ethoxy-6,8-difluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid, C15H13F2NO4
Authors: Zhang Chun-Yan , Nie Xu-Liang , Huang Guo-Ping , Xiong Yuan-Zhen , Huang Jian-Ping
Published: May 2021

C15H13F2NO4, monoclinic, P21/n (no. 14), a = 5.1342(10) Å, b = 9.6478(18) Å, c = 27.192(5) Å, β = 95.42°, V = 1340.9(4) Å3, Z = 4, R

gt
(F) = 0.0434, wR

ref
(F
2) = 0.1197, T = 296(2) K.
Impact of selected cement additives and model compounds on the solubility of Nd(III), Th(IV) and U(VI): screening experiments in alkaline NaCl, MgCl2 and CaCl2 solutions at elevated ionic strength
Authors: Adam Nicole , Hinz Katja , Gaona Xavier , Panak Petra J. , Altmaier Marcus
Published: May 2021

The solubility of Nd(III), Th(IV) and U(VI) was studied from undersaturation conditions in the presence of selected organic cement additives and model compounds: adipic acid, methyl acrylate, citric acid, melamine, ethylene glycol, phthalic acid and gluconic acid. Experiments were performed under Ar atmosphere in NaCl (2.5 and 5.0 M), MgCl2 (1.0 and 3.5 M) and CaCl2 (1.0 and 3.5 M) solutions with 9 ≤ pHm ≤ 13 (pHm = −log[H+]). Initial concentrations of organic ligands in solution were set constant in all systems to [L]0 = 0.025 M, except in specific cases (e.g. adipic acid, melamine and phthalic acid) where the ligand concentration in the matrix solutions was lower and controlled by solubility. Adipic acid, methyl acrylate, melamine, ethylene glycol and phthalic acid do not impact the solubility of Nd(III), Th(IV) and U(VI) in the investigated NaCl, MgCl2 and CaCl2 systems. Citrate significantly enhances the solubility of Nd(III), Th(IV) and U(VI) in NaCl systems. A similar effect was observed for Th(IV) and U(VI) in the presence of gluconate in NaCl systems. The impact of pH on the stability of the complexes is different for both ligands. Because of the larger number of alcohol groups in the gluconate molecule, this ligand is prone to form more stable complexes under hyperalkaline conditions that likely involve the deprotonation of several alcohol groups. The complexation of gluconate with U(VI) at pHm ≈ 13 is however weaker than at pHm ≈ 9 due to the competition with the highly hydrolysed moiety prevailing at pHm ≈ 13, i.e. UO2(OH)4
2−. The impact of citrate and gluconate in MgCl2 and CaCl2 systems is generally weaker than in NaCl systems, expectedly due to the competition with binary Mg-L and Ca-L complexes. However, the possible formation of ternary complexes further enhancing the solubility is hinted for the systems Mg/Ca-Th(IV)-GLU and Ca-U(VI)-GLU. These observations reflect again the differences in the complexation properties of citrate and gluconate, the key role of the alcohol groups present in the latter ligand, and the importances of interacting matrix cations. The screening experiments conducted within this study contribute to the identification of organic cement additives and model compounds potentially impacting the solution chemistry of An(III)/Ln(III), An(IV) and An(VI) under intermediate to high ionic strength conditions (2.5 ≤ I ≤ 10.5 M). This shows evident differences with respect to investigations conducted in dilute systems, and thus represents a very relevant input in the safety assessment of repositories for radioactive waste disposal where such elevated ionic strength conditions are expected.
The association of oxytocin with major depressive disorder: role of confounding effects of antidepressants
Authors: Xie Shiyi , Hu Yan , Fang Li , Chen Shijia , Botchway Benson O.A. , Tan Xiaoning , Fang Marong , Hu Zhiying
Published: May 2021

Major depressive disorder is a genetic susceptible disease, and a psychiatric syndrome with a high rate of incidence and recurrence. Because of its complexity concerning etiology and pathogenesis, the cure rate of first-line antidepressants is low. In recent years, accumulative evidences revealed that oxytocin act as a physiological or pathological participant in a variety of complex neuropsychological activities, including major depressive disorder. Six electronic databases (Web of Science, PubMed, Scopus, Google Scholar, CNKI, and Wanfang) were employed for researching relevant publications. At last, 226 articles were extracted. The current review addresses the correlation of the oxytocin system and major depressive disorder. Besides, we summarize the mechanisms by which the oxytocin system exerts potential antidepressant effects, including regulating neuronal activity, influencing neuroplasticity and regeneration, altering neurotransmitter release, down regulating hypothalamic–pituitary–adrenal axis, anti-inflammatory, antioxidation, and genetic effects. Increasing evidence shows that oxytocin and its receptor gene may play a potential role in major depressive disorder. Future research should focus on the predictive ability of the oxytocin system as a biomarker, as well as its role in targeted prevention and early intervention of major depressive disorder.
5-a-Side Game as a Tool for the Coach in Soccer Training
Authors: Branquinho Luís , Ferraz Ricardo , Marques Mário C.
Published: May 2021

Physical outputs in soccer training can be influenced by the interaction of several variables during the performance of different small side games (SSGs) formats. For this reason, it is relevant to understand how the manipulation of variables such as training method, exercise duration, number of repetitions, or recovery time affect the training loads and the performance. The main aim of this work was to provide coaches with relevant theoretical aspects and examples of practical applications to use from the specific format of 5-a-side SSG. To search for relevant publications and ensure the quality of articles, the search strategy used comprised specific search terms based on the research theme. The results showed that, during the 5-a-side game format, the choice of the training method (i.e., continuous or fractionated) and the manipulation of the related variables (e.g., number of players and game format) are fundamental for the management of the training load. Therefore, the manipulation of the variables using 5-a-side format translates into significant variations in the training load, and in the likely improvement of the different domains of soccer training (physiological, technical, and tactical), thus evidencing several benefits in the use of this game format. In addition, practical examples of 5-a-side exercises are used based on the theoretical considerations described.
Exploring the Physical and Physiological Characteristics Relevant to Mixed Martial Arts
Authors: Plush Matthew G. , Guppy Stuart N. , Nosaka Kazunori , Barley Oliver R.
Published: May 2021

Mixed martial arts (MMA) is a combat sport encompassing multiple methods of victory, including knockout, submission, and decision. Although research exists investigating physical and physiological characteristics important to MMA success, there is no consensus on the characteristics essential to performance and best practice for the assessment of such characteristics. Understanding the range of potential competitive approaches to MMA, it is difficult to determine 1 single physiological profile. Strength has been identified as a predictor of performance in combat sports, including MMA, wrestling, and Brazilian jiu jitsu (BJJ). Aerobic and anaerobic conditioning has been explored in combat sports, including BJJ, judo, boxing, kickboxing, and MMA, and has varying relationships to higher-level performance. Repeat effort ability, flexibility, and body composition have also been investigated, but there is a lack of depth in the literature. However, the use of other combat sports literature is not ideal and must be considered critically because of the complexity of MMA. Because MMA has multiple potential competitive styles, the previously mentioned characteristics may vary between successful athletes. Given the multifactorial nature of competition and methods to victory in MMA, further investigation into the physiological and physical characteristics should be undertaken for the advancement of the sport.
Melatonin ameliorates ovarian dysfunction by regulating autophagy in PCOS via the PI3K-Akt pathway
Authors: Xie Fenfen , Zhang Junhui , Zhai Muxin , Liu Yajing , Hu Hui , Yu Zhen , Zhang Junqiang , Lin Shuai , Liang Dan , Cao Yun-xia
Published: May 2021

Emerging evidence has demonstrated that melatonin (MT) plays a crucial role in regulating mammalian reproductive functions. It has been reported that MT has a protective effect on polycystic ovary syndrome (PCOS). However, the protective mechanisms of MT remain poorly understood. This study aims to explore the effect of MT on ovarian function in PCOS and to elucidate the relevant molecular mechanisms in vivo and in vitro. Here, we first analysed MT expression levels in the follicular fluid of PCOS patients. A significant reduction in MT expression levels was noted in PCOS patients. Intriguingly, reduced MT levels correlated with serum testosterone and inflammatory cytokine levels in follicular fluid. Moreover, we confirmed the protective function of MT through regulating autophagy in a dehydroepiandrosterone (DHEA)-induced PCOS rat model. Autophagy was activated in the ovarian tissue of the PCOS rat model, whereas additional MT inhibited autophagy by increasing PI3K-Akt pathway expression. In addition, serum-free testosterone, inflammatory and apoptosis indexes were reduced after MT supplementation. Furthermore, we also found that MT suppressed autophagy and apoptosis by activating the PI3K-Akt pathway in the DHEA-exposed human granulosa cell line KGN. Our study showed that MT ameliorated ovarian dysfunction by regulating autophagy in DHEA-induced PCOS via the PI3K-Akt pathway, revealing a potential therapeutic drug target for PCOS.
Descolonizar no es desmodernizar: un diálogo crítico entre S. Castro-Gómez y E. Dussel
Authors: Camelo Perdomo Diego Fernando
Published: May 2021

En este artículo nos disponemos desarrollar la tesis según la cual la crítica elaborada por Santiago Castro-Gómez a Enrique Dussel se trató de una desnaturalización del análisis del filósofo argentino sobre el proyecto moderno, en la cual Castro-Gómez puso de relieve las prácticas de las herencias coloniales como condición de posibilidad para la emergencia de la modernidad, sin necesidad de recurrir a la figura fundante del sujeto, aspecto que sí se encuentra presente en la propuesta del mendocino. Esta tesis se demostrará mediante un diálogo crítico entre estos dos autores en torno al problema de la modernidad y la colonialidad a partir de tres claves analíticas, la posmodernidad, la modernidad y la descolonización, con el fin de pensar el modo en que las prácticas coloniales operaron en el proyecto moderno a través del uso de los valores presentes en la misma modernidad, sin que ello implique caer en una supuesta desmodernización.
Historia de las ideas filosóficas: un método del filosofar latinoamericano
Authors: Tamayo Nicolás
Published: May 2021

En este artículo se exponen, previa presentación de algunas consideraciones iniciales sobre el pensamiento filosófico latinoamericano, las características y fundamentos principales de la historia de las ideas filosóficas latinoamericanas como un marco adecuado para pensar nuestros problemas propios. A propósito de esta disciplina filosófica, su justificación y su vigencia, se presentan algunas críticas hechas a esta tradición de pensamiento desde la filosofía posmoderna y contemporánea, las cuales han puesto de presente entre nosotros algunos pensadores colombianos. Culmina con la consideración de esta historiografía como un método filosófico “nuestroamericano”.
Lymphangioma of the Mesentery: Case Report and Review of the Literature
Authors: Gendvilaitė Neda , Drachneris Julius , Poškus Tomas
Published: May 2021

Background: Lymphangioma of the mesentery is a rare benign condition. Lymphangioma usually occurs in children during first few years of life most likely because of congenital abnormality of the lymphatic system. It may also be caused by trauma, lymphatic obstruction, surgery, inflammatory process, or radiotherapy. Lymphangioma of the mesentery represents less than 1% of all lymphangiomas and about 70% of abdominal lymphangiomas.Case presentation: We report the case of the 42-year-old woman who was diagnosed with the lymphangioma. Laparotomy was performed. A cystic lymph-filled tumor of about 12 cm in diameter was removed from the ileum mesentery. Conclusions:  Lymphangioma of the mesentery is a rare condition. Despite its benign nature, it can cause serious complications if not treated. Ultrasound and CT are used for detection of lymphangioma. It is important to surgically remove the lymphangiomas even in the absence of symptoms.
„Redis Cluster“ podėlio sistemos tyrimas, taikant formalius metodus
Authors: Kontrimas Mantas , Petrauskas Karolis
Published: May 2021

Šiame straipsnyje yra analizuojamas podėlio sistemos „Redis Cluster“ korektiškumas. Analizuojant sistemą buvo naudojami formalūs metodai – TLA+ specifikavimo kalba buvo sudaryta sistemos formali specifikacija. Specifikacijos modelio tikrinimo metu buvo vertinama, ar yra užtikrinama sistemos savybė, kad už vieną maišos lizdą yra atsakingas tik vienas pagrindinis mazgas ir jo pavaldūs mazgai. Atlikus modelio tikrinimą buvo surastos situacijos, kada ši sistemos savybė nėra užtikrinama. Surastos klaidos buvo atkartotos realioje sistemoje ir šioms klaidoms buvo pateikti galimi sprendimo būdai.
Dekomponavimo kortų metodas sudėtingoms informacinėms sistemoms dekomponuoti
Authors: Krasauskas Gediminas
Published: May 2021

Šiame straipsnyje pateikiami sudėtingų informacinių sistemų dekomponavimo, būtino siekiant mažinti artefakto, kurį reikia įgyvendinti, sudėtingumą, tyrimo rezultatai. Programų sistemų kūrimo srityje yra atlikta įvairių tyrimų, skirtų dekompozicijos procesui analizuoti ir kiekybiniams dekomponavimo rezultatų vertinimams atlikti. Tačiau programų sistemų kūrime naudojami „skaidyk ir valdyk“ metodai negali būti tiesiogiai taikomi sudėtingoms informacinėms sistemoms dekomponuoti, pamatuoti dekompozicijos gerumą ir palyginti su kitomis alternatyvomis. Pasiūlytasis dekomponavimo kortų metodas, kuris apima struktūrinį dekompozicijos vertinimą atsižvelgiant į kiekybinius atributus, charakterizuojamas kaip hierarchinis ir nedarantis konkrečių techninių sprendimų aukštame abstrakcijos lygmenyje. Gauti rezultatai sudaro prielaidas tolesniems tyrimams vykdyti.
Automatinė pilvo aortos atsišakojimų paieška kompiuterinės tomografijos nuotraukoje
Authors: Palkevič Vladyslav
Published: May 2021

Pilvo aortos modelio detalumas yra labai svarbus, vertinant šio organo kraujotaką bei galimų ligų simptomus. Aortos analizė vykdoma naudojant kompiuterinės tomografijos (CT) vaizdus. Siekiant automatiškai sužymėti pilvo aortos ribas CT vaizduose, naudojami tradiciniai vaizdų apdorojimo metodai, leidžiantys vaizde aptikti organo ribas (sienas). Tokie algoritmai turi trūkumą, susijusį su aortos atsišakojimų sekimu (pavyzdžiui, ties inkstais ar kojomis) – jie žymi tik vieną iš atšakų ir ignoruoja kitą. Šiame straipsnyje siūlomas problemos sprendimas – DBSCAN klasterizavimo algoritmo integravimas į ribų aptikimo algoritmus. Klasterizavimas aptinka, ar prasideda aortos atsišakojimas. Sprendimas priimamas pagal du vienas paskui kitą einančius CT nuotraukos vaizdus. Po atsišakojimo aptikimo kiekvienas klasteris kituose CT nuotraukos vaizduose gali būti analizuojamas atskirai. Todėl straipsnyje pateiktas atsišakojimo paieškos problemos sprendimo būdas leidžia ne tik rasti atsišakojimą naujame vaizde, bet ir toliau jį sekti kituose vaizduose.
Imbabura and Chimborazo at the cradle of Biogeography in the South American Andes
Authors: Gutierrez Alberto Gomez
Published: May 2021

The present contribution is a comprehensive review of the status of biodiversity of freshwater zooplankton of Uttarakhand Himalaya. Uttarakhand harbours a wide diversity in freshwater habitats in terms of rapids, riffles, runs, cascades of falls and pools of rivers and streams and the shallow and swift water of springs and lentic waters of lakes, ponds and reservoirs with varied physico-chemical environmental variables. Freshwater zooplankton of Uttarakhand are composed of the taxa of Protozoa, Rotifera, Copepoda, Cladocera and Ostrocoda. Ritifera contributes maximum (40.50%) with thirty two species followed by Protozoa (22.78%) with eighteen species and Cladocera (22.78%) with eighteen species to the total zooplankton taxa of Uttarakhand. Copepoda contributes 8.86% with seven species, while minimum contribution (5.08%) with only four species is made by Ostracoda to the total zooplankton taxa of Uttarakhand. Seasonal variation in the abundance of zooplankton in addition to diurnal vertical migration in diverse freshwater habitats of Uttarakhand Himalayahas also been reported.
Assessing Visitor Policy Exemption Requests During the COVID-19 Pandemic
Authors: Lanphier Elizabeth , Mosley Luke , Antommaria Armand H. Matheny
Published: May 2021

During the coronavirus disease 2019 (COVID-19) pandemic, many hospitals have added COVID-19–specific visitor restrictions to their routine visitor restrictions. These additional visitor restrictions are designed to reduce viral transmission, protect patients and staff, and conserve personal protective equipment. They typically exempt patients with disabilities and those who are dying. Consistent application of these policies may, however, be inequitable. We present the case of a single mother seeking an individual exemption to both a routine and a COVID-19 specific visitor restriction. One commentator focuses on the importance of clear and transparent processes for considering requests for exceptions. The other argues that disproportionate burdens may be mitigated in other ways and the policy maintained.
Laves phase crystal analysis (LaCA): Atomistic identification of lattice defects in C14 and C15 topologically close-packed phases
Authors: Xie Zhuocheng , Chauraud Dimitri , Bitzek Erik , Korte-Kerzel Sandra , Guénolé Julien
Published: May 2021

The identification of defects in crystal structures is crucial for the analysis of atomistic simulations. Many methods to characterize defects that are based on the classification of local atomic arrangement are available for simple crystalline structures. However, there is currently no method to identify both, the crystal structures and internal defects of topologically close-packed (TCP) phases such as Laves phases. We propose a new method, Laves phase crystal analysis (LaCA), to characterize the atomic arrangement in Laves crystals by interweaving existing structural analysis algorithms. The new method can identify the polytypes C14 and C15 of Laves phases, typical crystallographic defects in these phases, and common deformation mechanisms such as synchroshear and non-basal dislocations. Defects in the C36 Laves phase are detectable through deviations from the periodic arrangement of the C14 and C15 structures that make up this phase. LaCA is robust and extendable to other TCP phases.

Graphic abstract
Showerhead-assisted chemical vapor deposition of CsPbBr3 films for LED applications
Authors: Sanders S. , Simkus G. , Riedel J. , Ost A. , Schmitz A. , Muckel F. , Bacher G. , Heuken M. , Vescan A. , Kalisch H.
Published: May 2021

CsPbBr3 represents a highly attractive material for perovskite light-emitting diodes (PeLEDs) in the green spectral range. However, the lack of deposition tools for reproducible and scalable growth of perovskite films is one of the major obstacles hindering PeLED commercialization. Here, we employ the highly scalable showerhead-assisted chemical vapor deposition (CVD) method to produce uniform pinhole-free CsPbBr3 films for PeLED application. The precursors CsBr and PbBr2 are evaporated under low vacuum in N2 carrier gas. By adjusting the PbBr2 sublimation temperature, process conditions for CsBr-rich, stoichiometric, and PbBr2-rich CsPbBr3 layer growth have been developed. A substrate temperature of 160 °C enables direct growth of these CsPbBr3 films on a polymeric hole transport layer (HTL), finally yielding PeLEDs with a maximum luminance of 125 cd/m2. Although the device efficiency still lags behind solution-processed counterparts, our approach presents the first demonstration of PeLEDs containing CsPbBr3 films processed in a perovskite showerhead-assisted CVD reactor.

Graphic abstract
Kinship in the Strategies of Earning and Challenging Islamic Authority (a Tyumen Case-Study at the Turn of the XX–XXI Centuries)
Authors: Maksim Cherepanov
Published: May 2021

The study of authority is of great importance because it is a way of understanding why and how the worldview diversity is formed. The scholars describe the specific character and consequences of the use of authority; identify the factors which determine its acquisition, maintenance, and loss in certain social and historical conditions. The role of kinship in the strategies of earning and challenging Islamic authority among the Muslim Tatars living in Tyumen Region at the turn of the XX–XXI centuries has been considered in this article.. The article is based on the materials collected by the author during field research in the 2000s in urban and rural settlements of Tyumen Region. Methods of unstructured observation and interviews with a flexible questionnaire were used to collect the materials. We have used the grounded theory procedure to analyze them. In the article it is briefly described how the positions of Islamic authority have multiplied in the region since the late 1980s. The following main positions were identified: mullahs, abystai, astana keepers, organizers of religious rituals from among the residents, Ulema, imams, Islamic political activists. It is argued that these positions represent a specific set of characteristics that enables the bearers of authority to influence the connection between the laity and the supernatural world. Regarding the Muslim Tatars of Tyumen Region, it has been singled out the kinship as one of these characteristics. The patterns of strengthening / weakening its influence in the structure of Islamic authority were revealed. In particular, kinship plays a crucial role for mullahs, astana keepers, and apprentice imams. The role of kinship increases when there are enough religious specialists in a particular place and weakens when there is a lack of them. On the other hand, kin ties stop being an advantage for Islamic authority of a religious specialist, if he doesn't know “Islamic doctrine, rituals and the Arabic language” or isn't “engaged with the laity”.
A CASE STUDY ON WILLINGNESS TO COMMUNICATE IN ENGLISH IN THE IRANIAN TERTIARY EDUCATIONAL CONTEXT
Authors: Alimorad Zahra , Farahmand Mina
Published: May 2021

Willingness to communicate (WTC) in English is specifically important because L2 (foreign/second language) communication is considered to be a key factor in L2 learning. When the opportunity to speak English arises, there are generally two options: speaking or avoiding it. Several factors might exert influence on the choice of either option by different individuals. In this vein, the current study investigated the underlying factors that lead to (un)willingness on the part of Iranian EFL (English as a Foreign Language) tertiary students. Through a purposive sampling procedure, this classroom-based case study recruited and examined 10 EFL learners in Iran over a period of three weeks. Data were collected employing semi-structured interviews, classroom observations and stimulated-recall interviews. Thematic analysis was performed to identify common themes from the participating students’ ideas. Results reveal that participants’ L2 WTC emerges as a result of the complex, dynamic and non-linear interaction between individual, contextual, and linguistic factors. These three factors interdependently exerted either facilitative or inhibitive impacts on an individual student’s WTC in class at any point in time. The current study, therefore, reinforces the need for teachers to be aware of the multiple factors which lead learners to be more or less willing to communicate in L2 classrooms.
A SYSTEMATIC REVIEW OF COLLABORATIVE WRITING IMPLEMENTATION IN K-12 SECOND LANGUAGE CLASSROOMS
Authors: Lu Xinyue , Kim Solbee
Published: May 2021

In recognizing that writing is a social act, collaborative writing has received increased attention in second language (L2) classrooms. A large body of research literature explores the varied ways of L2 collaborative writing development in tertiary education settings, but relatively little is known about the implementation of collaborative writing in K-12 classrooms. In this study, the authors systematically reviewed a total of 12 peer-reviewed empirical studies on the use of collaborative writing in K-12 L2 classrooms to provide new insights into this particular context. Comprehensive analysis has been conducted, including the research context, writing task, mode of interaction, research focus, and assessment. The findings reveal that the majority of the selected studies have involved K-12 students learning English as a target language with diverse writing tasks. Three different collaborative writing approaches have been implemented in K-12 classrooms of L2, including face-to-face, online, and a blend of both styles. The main research foci of the reviewed literature are writing processes, writing outcomes, and collaborative writing affordances. Diverse assessment methods are utilized to measure L2 writers’ writing process and product. Drawing on the analyses, the researchers discuss the pedagogical implications and research strands that deserve further examination.
The Virus Yellows Epidemic in Sugar Beet in the UK in 2020 and the Adverse Effect of the EU Ban on Neonicotinoids on Sugar Beet Production
Authors: Dewar Alan M. , Qi Aiming
Published: May 2021

Virus yellows, the disease that was regarded as the worst scourge of sugar beet production in northern Europe in the 20th century, made a dramatic and devastating comeback in 2020, infecting up to 100% of some fields in the Fens of Cambridgeshire, and culminating in 38.1% infection
of the national crop, the highest incidence of this pernicious disease since the epidemics of 1974–1976. The causes of the latest epidemic were the consequences of a perfect storm – high overwintering survival of the principal vector, the peach potato aphid, Myzus persicae,
following a very mild winter, that resulted in early migration of infective aphids from overwintering hosts into newly emerging beet crops in April. These events, coupled with removal by EU dictate of the most efficient method of controlling the disease, namely the neonicotinoid seed treatments
that had kept it under control for the previous 26 years, and the depletion of alternative insecticide spray products, either due to other bans, or having been rendered ineffective by the development of resistance in the vectors, meant that growers were fighting a losing battle almost from
the day they sowed their seed. This article examines in detail how the 2020 epidemic developed, and the impact it had on the profitability of the sugar beet industry in the UK, and other parts of Europe. We also argue for a return of neonicotinoid seed treatments in future years to provide
more effective control of future pandemics, and thus maintain the presence of this important break crop in arable rotations.
Los acuerdos de elección de foro en los contratos internacionales de consumo Su eficacia en la Ley N° 19.496
Authors:   Universidad de los Andes, Cornejo Pablo A.
Published: May 2021

This study is divided into two parts. The first part analyzes the rationale for choice of court agreements, the roles they play in international contracts, and the difficulties arising when recognizing them in agreements between parties with unequal bargaining power, specifically in international consumer contracts. The second part analyses the national rules of international jurisdiction applicable to these contracts. Bearing this in mind, first, the current state of the discussion about their validity in Chile is explained; then the effect in this discussion of applying the provisions of Law No. 19.496 - on consumer rights protection (LPDC by its Spanish acronym), is studied. The international interpretation of the rules of jurisdiction set forth by this law, and the control it provides over abusive terms in consumer contracts are studied as possible solutions to stablish the validity of these contracts. The foregoing, in order to seek a solution that harmonizes, both, the purposes of international consumer protection and to recognize the international nature of their consumer relationship, which allows to consider these contracts as valid if some specific requirements are met.
La llamada valoración negativa de la prueba en la doctrina y la jurisprudencia
Authors:   Universidad Adolfo Ibañez, Correa Robles Carlos
Published: May 2021

This paper analyzes the so-called refusal to assess evidence in the Chilean criminal process. For this purpose, the most relevant case law of the higher courts in favor and against this possibility is presented, while also explaining the doctrine’s stance in this regard. In conclusion, the reader is provided with a position in favor of such refusal to assess evidence, understanding it as a mechanism to safeguard the effective protection of fundamental guarantees in obtaining evidence, beyond the exclusionary rule of evidence.
Sobre la equidad contractual y la obligatoriedad del vínculo: Una mirada a la luz de la protección jurídica del contratante débil
Authors:   Universidad del Desarrollo, Munita Marambio Renzo
Published: May 2021

Contractual fairness and the will’s role on the bindingness of contracts can be regarded as essential elements for the task of juridically argument that it is possible to find enough tools within the law of obligations to protect the contracting party that is in a weak position with respect to the other. In this sense, it is not necessary to have the status of a consumer to be entitled to the aforementioned protection, since such regime can be articulated from particular notions integrated to our legal system. In this framework, the modern interpretation of legitimate trust and contractual equilibrium are stressed. These notions can be inspired by the favor debilis criterion rather than the notion of good faith. This criterion is fundamental to define the directive line of this work.
La naturaleza jurídica y caracteres de la acción del artículo 669 inciso 1° del Código Civil chileno
Authors:   Universidad Adolfo Ibañez, Núñez Cádiz Ricardo
Published: May 2021

In the present work the legal nature of the action established on article 669 paragraph 1° of the Chilean Civil Code is explored; even though it seems to be agreement as to what a restitutionary reimbursement is, this is not asserted enough, which generates difficulties at the judicial level. Indeed, concerning the action of reimbursement granted by article 669 paragraph 1°, no distinction has been drawn between the restitutionary and compensatory character of the norm. Having an unduly property allocation taken place, the principle of unjustified enrichment imposes the obligation of restituting, thus not being required a correlative impoverishment in order to claim the restitutionary reimbursement, since the action is not aimed at compensating the impoverished, but to recovered the unduly assigned enrichment, this way, regarding the studied action the stress muss shift from the amount of the impoverishment to the effective amount of the enrichment, so as not to apply the compensatory logic to the restitutionary reimbursement.
INVESTIGATION INTO THE CHALLENGES FACING PLANNING OF MATHEMATIC PROGRAMME IN SENIOR SECONDARY EDUCATION IN ABUJA, NIGERIA
Authors: Jacob Ogunode Niyi
Published: May 2021

The aim of this study is to investigate the challenges facing the planning of mathematics programme in Federal Capital Territory, Nigeria. The study adopted descriptive research survey design. The population of the study comprised ninety (90) respondents. Stratified and systematic sampling
technique was used to select the sample population. The study employed the used of questionnaire as instrument for data collection. Two lecturers from Educational Administration and planning from University of Abuja was consulted to validate the questionnaire. Three research questions and
two hypotheses were developed for the study. Test-retest reliability was employed for the study. Percentage and Chi-square test was used to test the hypotheses and data collected from the study. The result revealed that there are challenges facing the planning of mathematics programme of senior
secondary education and the challenges includes; inadequate data/information to plan, inadequate funding of planning of mathematics programme, poor capacity development of few mathematics planners, inadequate professional mathematics planners ,political instability, corruption and lack of
political will to support planning of mathematics education. The study concluded that the implication of the challenges on the implementation mathematics education is poor implementation of the mathematics programme in the senior secondary schools. The study recommends that the government
should increase the funding of educational planning in the country especially mathematics education.
Sociodemographic profile of primiparous mothers from nine birth cohorts in three Brazilian cities
Authors: Farias-Antunez Simone , Simões Vanda Maria Ferreira , Cardoso Viviane Cunha , Silveira Mariângela Freitas da
Published: May 2021

Fertility reduction is a phenomenon observed in demographic transition. The demographic changes noted in female fertility represent a need for adjustment on health services regarding female health and family planning support. Thus, this study aimed to perform a descriptive analysis by tracing the sociodemographic profile of primiparous mothers belonging to nine Brazilian birth cohorts, in three cities from different states. Standardized questionnaires were applied to assess reproductive characteristics and covariables. Primiparous mothers were defined as women whose child included in birth cohorts was their firstborn child. Sample description was performed using analysis of variance (continuous variables) and chi-square (categorical variables). In total, 44,615 women were included in the analyses and 41.8% (95%CI: 41.3; 42.2) were categorized as primiparous. The primiparity rates were the lowest in Ribeirão Preto (São Paulo State) 1978 (32%; 95%CI: 30.9; 33.1) and the highest in most recent cohorts, reaching up to 50% of the participants (São Luís - Maranhão State 2010: 47.2%; 95%CI: 45.8; 48.6; Ribeirão Preto 2010: 50.2%; 95%CI: 49.1; 51.4); Pelotas (Rio Grande do Sul State) 2015: 49.4% (95%CI: 47.9; 50.9). Primiparous mothers’ age and schooling increased over the years in all cohorts. Maternal age at the first childbirth behaved similarly in the three studied cities. There was an increase in the proportion of first-time mothers that were older, higher educated and belonged to richer income groups. Also, the proportion of teenage mothers (aged 15 years or younger) increased until the early 2000’s and started decreasing around the years 2010, especially among women in the poorer income groups.
Inundações e leptospirose nos municípios brasileiros no período de 2003 a 2013: utilização de técnicas de mineração de dados
Authors: Gracie Renata , Xavier Diego Ricardo , Medronho Roberto
Published: May 2021

A leptospirose se relaciona a problemas de saneamento ambiental, com incremento de casos em períodos de inundações. Levando-se em consideração as questões relacionadas a mudanças climáticas, as inundações tendem a um aumento. As inundações não atingem as populações de maneira homogênea, em geral os menos favorecidos em termos socioeconômicos são os mais acometidos. Para saber se o número de inundações aumentaria a incidência de leptospirose e sua relação com as variáveis contextuais, utilizou-se dados socioeconômicos, ambientais e de ocorrência da doença no nível municipal. Os municípios que tinham problemas no esgotamento sanitário apresentaram maior risco para a ocorrência da leptospirose. O total de inundações adquirida a partir da decretação pela autoridade municipal constituiu um importante marcador de risco para a ocorrência de leptospirose. A modelagem de árvore de regressão mostrou-se útil para estimar a ocorrência de leptospirose no Brasil.
A NEW APPROACH FOR HEMORRHOID DISEASE: SELECTIVE DEARTERIALIZATION AND MUCOPEXY WITHOUT DOPPLER GUIDANCE
Authors: SOBRADO Carlos Walter , SOBRADO Lucas Faraco , NAHAS Sergio Carlos , CECCONELLO Ivan
Published: May 2021

ABSTRACT Background: Transanal hemorrhoidal dearterialization (THD) is safe and effective minimally invasive treatment for hemorrhoidal disease, but reports regarding recurrence and postoperative complications (pain and tenesmus) vary significantly. Aim: To evaluate if selective dearterialization and mucopexy at the symptomatic hemorrhoid only, without Doppler guidance, achieves adequate control of the prolapse and bleeding and if postoperative morbidity is reduced with this technique. Methods: Twenty consecutive patients with grade II and III hemorrhoids were treated with this new approach and were evaluated for postoperative complications and recurrence. Results: Control of prolapse and bleeding was achieved in all patients (n=20). Postoperative complications were tenesmus (n=2), external hemorrhoidal thrombosis (n=2) and urinary retention (n=2). After a mean follow-up of 13 months no recurrences were diagnosed. Conclusion: Selective dearterialization and mucopexy is safe and achieves adequate control of prolapse and bleeding and, by minimizing sutures in the anal canal, postoperative morbidity is diminished. Doppler probe is unnecessary for this procedure, which makes it also more interesting from an economic perspective.