bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical Modeling: Issues and Challenges in Mathematics Education and Teaching
Authors: Asempapa Reuben S. , Sturgill Derek J.
Published: September 2019

Mathematics education researchers and policy documents in the United States have expressed the need to improve the teaching and learning of mathematical modeling at the K–12 levels so that students can apply their knowledge of mathematics to solve real-world situations. Unfortunately, most practicing teachers (PTs) and preservice teachers (PSTs) acquire didactical and pedagogical styles that do not support effective modeling practices. To investigate these dilemmas, this study examined PTs’ pedagogical experiences in and PSTs’ perspectives on mathematical modeling practices. Participants included 62 PTs and 18 PSTs from a Midwestern region of the United States. Data originated from questionnaire items and open-ended questions, which were analyzed quantitatively and qualitatively. Varied participants’ ideas on mathematical modeling practices were identified, recorded, and summarized. Results indicated that most of these PTs and PSTs have little to no experiences with mathematical modeling practices and associated pedagogies. Such results along with a supplemental discussion have implications for teacher education programs and professional development centered on mathematical modeling education.
Smallholder Farmers’ Decision to Participate in Vegetable Marketing and the Volume of Sales in West Shewa Zone of Oromia National Regional State, Ethiopia
Authors: Rikitu Aman , Emana Bezabih , Haji Jema , Bekele Ketema
Published: September 2019

This study examines vegetable producers’ market participation and sales volume using cross-sectional data obtained from 385 randomly and proportionately sampled households from West Shewa zone, Oromia region of Ethiopia. Heckman two-step procedure was used to analyse the determinants of participation in vegetables markets and volume of sales during the study period. Probit model shows that education level, distance to nearest market, access to irrigation, use of pesticide and participation in any civic organization significantly affect market participation decision. Further, results from ordinary least squares regression show that sex of household head, land size, distance to farmer training centre, access to irrigation, use of pesticide and participation in civic organization significantly affect the level of market participation of the farm households in vegetable markets. The findings imply that support for female households, improving adult based education, participation in civic organization, infrastructure, access to irrigation and improved inputs are a means to increase vegetable production market participation and sales volume in West Shewa, Ethiopia.
Interfuel Substitution: Evidence from the Markov Switching Minflex Laurent Demand System with BEKK Errors
Authors: Serletis Apostolos , Xu Libo
Published: September 2019

We investigate interfuel substitution in the United States using the minflex Laurent demand system and a century of data (from 1919 to 2012). We relax the assumption of constant parameters in the demand system, and also relax the ho-moskedasticity assumption, instead assuming that the covariance matrix of the errors is time-varying. Our results are consistent with theoretical regularity and indicate that the Morishima elasticities of substitution are always positive for all pairs of the energy goods (suggesting substitutability), but exhibit large swings across two regimes, generally being higher in the high demand volatility regime before the 1950s.
Cross-border Effects of Capacity Remuneration Schemes in Interconnected Markets: Who is Free-riding?
Authors: Lambin Xavier , Léautier Thomas-Olivier
Published: September 2019

We study the welfare impacts of domestic support schemes for generation capacity when energy markets are interconnected. We find that if transmission system operators (TSOs) can’t reduce export capacity and neighbors stay energy-only, a capacity market is ineffective unless transmission capacity is small. If TSOs can reduce export capacity, the capacity market attracts investments and Security of Supply (SoS) of non-domestic markets shrink. A neighboring energy-only or strategic reserve market will thus be prejudiced in the long-run and may have to implement a capacity market as well in order to meet its SoS standard. Hence, capacity markets may spread in Europe thanks to their negative cross-border effect on investment incentives. This is in sharp contrast with the conventional wisdom, based on short-term arguments, that energy-only markets will free-ride the SoS provided by neighboring capacity markets. Our conclusions urge for the harmonization of capacity remuneration schemes across Europe.
From grammar to reading: a study on referential dependencies
Authors: Batalha Joana
Published: September 2019

In this article, we present a study that investigated relations between grammar teaching and reading in Portuguese as mother tongue. The study, in which 91 students have participated, aimed at (i) pre-assessing students’ ability to comprehend referential dependencies in reading at different stages (grade 4, 9-10 years old; grade 6, 11-12 years old; and grade 8, 12‑13 years old), (ii) proposing a teaching intervention to develop language awareness about referential dependencies and, more specifically, to develop strategies to identify antecedents of pronouns (grade 4) and (iii) assessing the effects of the teaching intervention (grade 4). The study was based on a quasi‑experimental methodology, with pre and posttests and a teaching intervention developed in the classroom, based on discovery-learning methods. Results of the study, which show positive effects of the teaching intervention, reinforce the benefits of grammar teaching as language awareness development. The study also offers a contribution towards the discussion of the role of grammar teaching to the development of late acquired structures, such as particular types of referential dependencies.
Report from the 5th Lithuanian-Polish Otorhinolaryngological Congress
Authors: Wojciechowski Tomasz , Bruzgielewicz Antoni , Niemczyk Kazimierz
Published: September 2019

W dniach 13-15 czerwca 2019 roku w Druskiennikach odbył się 5. Litewsko-Polski Kongres Otorynolaryngologiczny. Był on wyrazem wieloletniej współpracy w zakresie spotkań naukowych ośrodków obydwu krajów. Na wspólne zaproszenie profesora Virgilijusa Ulozy, Kierownika Katedry i Kliniki Otorynolaryngologii Litewskiego Uniwersytetu Nauk Medycznych i profesora Kazimierza Niemczyka, Kierownika Katedry i Kliniki Otorynolaryngologii, Chirurgii Głowy i Szyi WUM, odpowiedziało ponad 150 lekarzy z krajów organizatorów, ale również m.in. z Austrii, Wielkiej Brytanii, Białorusi i Czech.
'#BeYourself': ¿Pueden las redes sociales ayudar a mejorar la autoestima de los adolescentes?
Authors: Montaña Blasco Mireia
Published: September 2019

El uso de las redes sociales entre los adolescentes aumenta año tras año. Según datos del Pew Research Center, su consumo es casi universal. Aunque su uso ha sido criticado durante mucho tiempo y se ha etiquetado como banal o incluso narcisista, algunos estudios confirman que las redes sociales ayudan a los adolescentes a sentirse más conectados con la vida cotidiana de sus amigos y con sus propios sentimientos. También les ofrecen un lugar donde recibir el apoyo de los demás en momentos difíciles.
Optical estimation of absolute membrane potential using fluorescence lifetime imaging
Authors: Lazzari-Dean Julia R , Gest Anneliese MM , Miller Evan W
Published: September 2019

All cells maintain ionic gradients across their plasma membranes, producing transmembrane potentials (Vmem). Mounting evidence suggests a relationship between resting Vmem and the physiology of non-excitable cells with implications in diverse areas, including cancer, cellular differentiation, and body patterning. A lack of non-invasive methods to record absolute Vmem limits our understanding of this fundamental signal. To address this need, we developed a fluorescence lifetime-based approach (VF-FLIM) to visualize and optically quantify Vmem with single-cell resolution in mammalian cell culture. Using VF-FLIM, we report Vmem distributions over thousands of cells, a 100-fold improvement relative to electrophysiological approaches. In human carcinoma cells, we visualize the voltage response to growth factor stimulation, stably recording a 10–15 mV hyperpolarization over minutes. Using pharmacological inhibitors, we identify the source of the hyperpolarization as the Ca2+-activated K+ channel KCa3.1. The ability to optically quantify absolute Vmem with cellular resolution will allow a re-examination of its signaling roles.
Evolutionary emergence of Hairless as a novel component of the Notch signaling pathway
Authors: Miller Steven W , Movsesyan Artem , Zhang Sui , Fernández Rosa , Posakony James W
Published: September 2019

Suppressor of Hairless [Su(H)], the transcription factor at the end of the Notch pathway in Drosophila, utilizes the Hairless protein to recruit two co-repressors, Groucho (Gro) and C-terminal Binding Protein (CtBP), indirectly. Hairless is present only in the Pancrustacea, raising the question of how Su(H) in other protostomes gains repressive function. We show that Su(H) from a wide array of arthropods, molluscs, and annelids includes motifs that directly bind Gro and CtBP; thus, direct co-repressor recruitment is ancestral in the protostomes. How did Hairless come to replace this ancestral paradigm? Our discovery of a protein (S-CAP) in Myriapods and Chelicerates that contains a motif similar to the Su(H)-binding domain in Hairless has revealed a likely evolutionary connection between Hairless and Metastasis-associated (MTA) protein, a component of the NuRD complex. Sequence comparison and widely conserved microsynteny suggest that S-CAP and Hairless arose from a tandem duplication of an ancestral MTA gene.
Sustained expression of HeyL is critical for the proliferation of muscle stem cells in overloaded muscle
Authors: Fukuda Sumiaki , Kaneshige Akihiro , Kaji Takayuki , Noguchi Yu-taro , Takemoto Yusei , Zhang Lidan , Tsujikawa Kazutake , Kokubo Hiroki , Uezumi Akiyoshi , Maehara Kazumitsu , Harada Akihito , Ohkawa Yasuyuki , Fukada So-ichiro
Published: September 2019

In overloaded and regenerating muscle, the generation of new myonuclei depends on muscle satellite cells (MuSCs). Because MuSC behaviors in these two environments have not been considered separately, MuSC behaviors in overloaded muscle remain unexamined. Here, we show that most MuSCs in overloaded muscle, unlike MuSCs in regenerating muscle, proliferate in the absence of MyoD expression. Mechanistically, MuSCs in overloaded muscle sustain the expression of Heyl, a Notch effector gene, to suppress MyoD expression, which allows effective MuSC proliferation on myofibers and beneath the basal lamina. Although Heyl-knockout mice show no impairment in an injury model, in a hypertrophy model, their muscles harbor fewer new MuSC-derived myonuclei due to increased MyoD expression and diminished proliferation, which ultimately causes blunted hypertrophy. Our results show that sustained HeyL expression is critical for MuSC proliferation specifically in overloaded muscle, and thus indicate that the MuSC-proliferation mechanism differs in overloaded and regenerating muscle.
An arbitrary-spectrum spatial visual stimulator for vision research
Authors: Franke Katrin , Maia Chagas André , Zhao Zhijian , Zimmermann Maxime JY , Bartel Philipp , Qiu Yongrong , Szatko Klaudia P , Baden Tom , Euler Thomas
Published: September 2019

Visual neuroscientists require accurate control of visual stimulation. However, few stimulator solutions simultaneously offer high spatio-temporal resolution and free control over the spectra of the light sources, because they rely on off-the-shelf technology developed for human trichromatic vision. Importantly, consumer displays fail to drive UV-shifted short wavelength-sensitive photoreceptors, which strongly contribute to visual behaviour in many animals, including mice, zebrafish and fruit flies. Moreover, many non-mammalian species feature more than three spectral photoreceptor types. Here, we present a flexible, spatial visual stimulator with up to six arbitrary spectrum chromatic channels. It combines a standard digital light processing engine with open source hard- and software that can be easily adapted to the experimentalist’s needs. We demonstrate the capability of this general visual stimulator experimentally in the in vitro mouse retinal whole-mount and the in vivo zebrafish. With this work, we intend to start a community effort of sharing and developing a common stimulator design for vision research.
Paenibacillusstrains with nitrogen fixation and multiple beneficial properties for promoting plant growth
Authors: Liu Xiaomeng , Li Qin , Li Yongbin , Guan Guohua , Chen Sanfeng
Published: September 2019

Paenibacillusis a large genus of Gram-positive, facultative anaerobic, endospore-forming bacteria. The genusPaenibacilluscurrently comprises more than 150 named species, approximately 20 of which have nitrogen-fixation ability. The N2-fixingPaenibacillusstrains have potential uses as a bacterial fertilizer in agriculture. In this study, 179 bacterial strains were isolated by using nitrogen-free medium after heating at 85 °C for 10 min from 69 soil samples collected from different plant rhizospheres in different areas. Of the 179 bacterial strains, 25Paenibacillusstrains hadnifHgene encoding Fe protein of nitrogenase and showed nitrogenase activities. Of the 25 N2-fixingPaenibacillusstrains, 22 strains produced indole-3-acetic acid (IAA). 21 strains out of the 25 N2-fixingPaenibacillusstrains inhibited at least one of the 6 plant pathogensRhizoctonia cerealis,Fusarium graminearum,Gibberella zeae,Fusarium solani,Colletotrichum gossypiiandAlternaria longipes. 18 strains inhibited 5 plant pathogens andPaenibacillussp. SZ-13b could inhibit the growth of all of the 6 plant pathogens. According to the nitrogenase activities, antibacterial capacities and IAA production, we chose eight strains to inoculate wheat, cucumber and tomato. Our results showed that the 5 strainsPaenibacillussp. JS-4,Paenibacillussp. SZ-10,Paenibacillussp. SZ-14,Paenibacillussp. BJ-4 andPaenibacillussp. SZ-15 significantly promoted plant growth and enhanced the dry weight of plants. Hence, the five strains have the greater potential to be used as good candidates for biofertilizer to facilitate sustainable development of agriculture.
California air resources board forest carbon protocol invalidates offsets
Authors: Marino Bruno D.V. , Mincheva Martina , Doucett Aaron
Published: September 2019

The commercial asset value of sequestered forest carbon is based on protocols employed globally; however, their scientific basis has not been validated. We review and analyze commercial forest carbon protocols, claimed to have reduced net greenhouse gas emissions, issued by the California Air Resources Board and validated by the Climate Action Reserve (CARB-CAR). CARB-CAR forest carbon offsets, based on forest mensuration and model simulation, are compared to a global database of directly measured forest carbon sequestration, or net ecosystem exchange (NEE) of forest CO2. NEE is a meteorologically based method integrating CO2 fluxes between the atmosphere, forest and soils and is independent of the CARB-CAR methodology. Annual carbon accounting results for CAR681 are compared with NEE for the Ameriflux site, Howland Forest Maine, USA, (Ho-1), the only site where both methods were applied contemporaneously, invalidating CARB-CAR protocol offsets. We then test the null hypothesis that CARB-CAR project population data fall within global NEE population values for natural and managed forests measured in the field; net annual gC m−2yr−1 are compared for both protocols. Irrespective of geography, biome and project type, the CARB-CAR population mean is significantly different from the NEE population mean at the 95% confidence interval, rejecting the null hypothesis. The CARB-CAR population exhibits standard deviation ∼5× that of known interannual NEE ranges, is overcrediting biased, incapable of detecting forest transition to net positive CO2 emissions, and exceeds the 5% CARB compliance limit for invalidation. Exclusion of CO2 efflux via soil and ecosystem respiration precludes a valid net carbon accounting result for CARB-CAR and related protocols, consistent with our findings. Protocol invalidation risk extends to vendors and policy platforms such as the United Nations Program on Reducing Emissions from Deforestation and Forest Degradation (REDD+) and the Paris Agreement. We suggest that CARB-CAR and related protocols include NEE methodology for commercial forest carbon offsets to standardize methods, ensure in situ molecular specificity, verify claims of carbon emission reduction and harmonize carbon protocols for voluntary and compliance markets worldwide.
Elucidating the Impact of Charge Selective Contact in Halide Perovskite through Impedance Spectroscopy
Authors: Khan Mohd Taukeer , Salado Manuel , Almohammedi Abdullah , Kazim Samrana , Ahmad Shahzada
Published: September 2019

The electron and hole selective contact (SC) plays a pivotal role in the performance of perovskite solar cells. In order to separate the interfacial phenomenon from bulk, the influence of charge SC is elucidated, by means of impedance spectroscopy. The specific role played by TiO2 and Spiro‐OMeTAD as electron and hole SC in perovskite solar cells is investigated at short circuit condition at different temperatures. The methylammonium lead triiodide (MAPbI3) and mixed perovskite of formamidinium lead iodide and methylammonium lead bromide namely; (FAPbI3)0.85(MAPbBr3)0.15 are probed and parameters such as charge carrier mobility, recombination resistance, time constant, and charge carrier kinetics in perovskite layer and at the interface of perovskite/SC are elucidated. Charge carrier mobility in mixed perovskite is found to be nearly two order of magnitude higher as compared to MAPbI3. Moreover, the carrier mobility in devices with only electron SC is found to be higher as compared only hole SC. The charge accumulation at TiO2/perovskite/Spiro‐OMeTAD interfaces is studied via frequency dependent capacitance, revealing higher charge accumulation at perovskite/Spiro‐OMeTAD than at TiO2/perovskite interface. By performing varying temperature frequency dependent capacitance measurements the distribution of density of state within the bandgap of the perovskites, the emission rate of electrons from the trap states and traps activation energy is determined.
Light‐Ferroic Interaction in Hybrid Organic–Inorganic Perovskites
Authors: Liu Yongtao , Ievlev Anton V. , Collins Liam , Borodinov Nikolay , Belianinov Alex , Keum Jong K. , Wang Miaosheng , Ahmadi Mahshid , Jesse Stephen , Xiao Kai , Sumpter Bobby G. , Hu Bin , Kalinin Sergei V. , Ovchinnikova Olga S.
Published: September 2019

Given the remarkable performance of hybrid organic–inorganic perovskites (HOIPs) in solar cells, light emitters, and photodetectors, the quest to advance the fundamental understanding of the photophysical properties in this class of materials remains highly relevant. Recently, the discovery of ferroic twin domains in HOIPs has renewed the debate of the ferroic effects on optoelectric processes. This work explores the interaction between light and ferroic twin domains in CH3NH3PbI3. Due to strain and chemical inhomogeneities, photogenerated electrons and holes show a preferential motion in the ferroelastic twin domains. Density functional theory (DFT) shows that electrons and holes result in lattice expansion in CH3NH3PbI3 differently. Hence, light generates strain in the ferroelastic domains due to preferential photocarrier motion, leading to a screening of strain variation. X‐ray diffraction studies verify the DFT simulations and reveal that the photoinduced strain is light intensity dependent, and the photoexcitation is a prerequisite of inducing strain by light. This work extends the fundamental understanding of light‐ferroic interaction and offers guidance for developing functional devices.
A New Pathology in the Simulation of Chaotic Dynamical Systems on Digital Computers
Authors: Boghosian Bruce M. , Coveney Peter V. , Wang Hongyan
Published: September 2019

Systematic distortions are uncovered in the statistical properties of chaotic dynamical systems when represented and simulated on digital computers using standard IEEE floating‐point numbers. This is done by studying a model chaotic dynamical system with a single free parameter β, known as the generalized Bernoulli map, many of whose exact properties are known. Much of the structure of the dynamical system is lost in the floating‐point representation. For even integer values of the parameter, the long time behaviour is completely wrong, subsuming the known anomalous behaviour for β = 2. For non‐integer β, relative errors in observables can reach 14%. For odd integer values of β, floating‐point results are more accurate, but still produce relative errors two orders of magnitude larger than those attributable to roundoff. The analysis indicates that the pathology described, which cannot be mitigated by increasing the precision of the floating point numbers, is a representative example of a deeper problem in the computation of expectation values for chaotic systems. The findings sound a warning about the uncritical application of numerical methods in studies of the statistical properties of chaotic dynamical systems, such as are routinely performed throughout computational science, including turbulence and molecular dynamics.
Ti‐Gradient Doping to Stabilize Layered Surface Structure for High Performance High‐Ni Oxide Cathode of Li‐Ion Battery
Authors: Kong Defei , Hu Jiangtao , Chen Zhefeng , Song Kepeng , Li Cheng , Weng Mouyi , Li Maofan , Wang Rui , Liu Tongchao , Liu Jiajie , Zhang Mingjian , Xiao Yinguo , Pan Feng
Published: September 2019

High‐Ni layered oxide cathodes are considered to be one of the most promising cathodes for high‐energy‐density lithium‐ion batteries due to their high capacity and low cost. However, surfice residues, such as NiO‐type rock‐salt phase and Li2CO3, are often formed at the particle surface due to the high reactivity of Ni3+, and inevitably result in an inferior electrochemical performance, hindering the practical application. Herein, unprecedentedly clean surfaces without any surfice residues are obtained in a representative LiNi0.8Co0.2O2 cathode by Ti‐gradient doping. High‐resolution transmission electron microscopy (TEM) reveals that the particle surface is composed of a disordered layered phase (≈6 nm in thickness) with the same rhombohedra structure as its interior. The formation of this disordered layered phase at the particle surface is electrochemically favored. It leads to the highest rate capacity ever reported and a superior cycling stability. First‐principles calculations further confirm that the excellent electrochemical performance has roots in the excellent chemical/structural stability of such a disordered layered structure, mainly arising from the improved robustness of the oxygen framework by Ti doping. This strategy of constructing the disordered layered phase at the particle surface could be extended to other high‐Ni layered transition metal oxides, which will contribute to the enhancement of their electrochemical performance.
Hemokinin‐1 stimulates C‐C motif chemokine ligand 24 production in macrophages to enhance eosinophilic inflammation in nasal polyps
Authors: Deng Yi‐Ke , Ma Jin , Wang Zhi‐Chao , Long Xiao‐Bo , Chen Cai‐Ling , Feng Qi‐Miao , Zhang Xin‐Hao , Zeng Ming , Wang Heng , Lu Xiang , Liu Zheng
Published: September 2019

Background

The mechanisms underlying mucosal eosinophilia in chronic rhinosinusitis with nasal polyps (CRSwNP) remain poorly clarified. The nervous system and neuropeptides play an important role in the regulation of immune response. Herein we explore the expression and function of hemokinin‐1 (HK‐1), a newly identified tachykinin, along with its receptor neurokinin 1 receptor (NK1R) in CRSwNP.

Methods

HK‐1, NK1R, and C‐C motif chemokine ligand 24 (CCL24) expression in nasal tissues (53 eosinophilic CRSwNP, 32 non‐eosinophilic CRSwNP, and 33 controls) was investigated by quantitative reverse transcript polymerase chain reaction (RT‐PCR) and immunofluorescence staining. THP‐1, a human monocytic leukemia cell line, and eosinophilic polyp tissues were stimulated with HK‐1. Cells, tissues, and culture supernatants were subsequently collected for detection of the production of various inflammatory cytokines and chemokines by quantitative RT‐PCR and enzyme‐linked immunoassay.

Results

HK‐1 and NK1R mRNA and protein expression were upregulated in eosinophilic and non‐eosinophilic nasal polyps compared with control tissues, with eosinophilic polyps demonstrating a higher upregulation compared with that of non‐eosinophilic polyps. Eosinophils constituted the major source of HK‐1, whereas macrophages were the predominant cell type exhibiting NK1R in eosinophilic polyps. HK‐1 induced CCL24 production from macrophages differentiated from THP‐1 cells; this was abolished by an NK1R antagonist. HK‐1 also induced CCL24 production from ex vivo‒cultured eosinophilic nasal polyps. CCL24 was expressed by macrophages in eosinophilic but not non‐eosinophilic polyps. The expression level of HK‐1 correlated with CCL24 expression and tissue eosinophilia in eosinophilic nasal polyps.

Conclusion

Eosinophil‐derived HK‐1 induces CCL24 production from macrophages and therefore exaggerates eosinophilic inflammation in CRSwNP.
Near‐Infrared Optogenetic Genome Engineering Based on Photon‐Upconversion Hydrogels
Authors: Sasaki Yoichi , Oshikawa Mio , Bharmoria Pankaj , Kouno Hironori , Hayashi‐Takagi Akiko , Sato Moritoshi , Ajioka Itsuki , Yanai Nobuhiro , Kimizuka Nobuo
Published: September 2019

Photon upconversion (UC) from near‐infrared (NIR) light to visible light has enabled optogenetic manipulations in deep tissues. However, materials for NIR optogenetics have been limited to inorganic UC nanoparticles. Herein, NIR‐light‐triggered optogenetics using biocompatible, organic TTA‐UC hydrogels is reported. To achieve triplet sensitization even in highly viscous hydrogel matrices, a NIR‐absorbing complex is covalently linked with energy‐pooling acceptor chromophores, which significantly elongates the donor triplet lifetime. The donor and acceptor are solubilized in hydrogels formed from biocompatible Pluronic F127 micelles, and heat treatment endows the excited triplets in the hydrogel with remarkable oxygen tolerance. Combined with photoactivatable Cre recombinase technology, NIR‐light stimulation successfully performs genome engineering resulting in the formation of dendritic‐spine‐like structures of hippocampal neurons.
Access to Cyclic β‐Amino Acids by Amine‐Catalyzed Enantioselective Addition of the γ‐Carbon Atoms of α,β‐Unsaturated Imines to Enals
Authors: Luo Guoyong , Huang Zhijian , Zhuo Shitian , Mou Chengli , Wu Jian , Jin Zhichao , Chi Yonggui Robin
Published: September 2019

Disclosed herein is a new catalytic approach for an efficient access to cyclic β‐amino acids widely found in bioactive small molecules and peptidic foldamers. Our method involves addition of the remote γ‐carbon atoms of α,β‐unsaturated imines to enals by iminium organic catalysis. This highly chemo‐ and stereo‐selective reaction affords cyclic β‐amino aldehydes that can be converted to amino acids bearing quaternary stereocenters with exceptional optical purities. Our study demonstrates the unique power of organic catalytic remote carbon reactions in rapid synthesis of functional molecules.
Sequential chemical and enzymatic pretreatment of palm empty fruit bunches for Candida pelliculosa bioethanol production
Authors: Campioni Tania Sila , Soccol Carlos Ricardo , Libardi Junior Nelson , Rodrigues Cristine , Woiciechowski Adenise Lorenci , Letti Luiz Alberto Junior , Vandenberghe Luciana Porto de Souza
Published: September 2019

Second‐generation bioethanol production process was developed using pretreated empty fruit bunches (EFB). Consecutive acid/alkali EFB pretreatment was performed, first with HCl and then with NaOH with final washing steps for phenolic compounds elimination. Scanning electron microscopy images showed that EFB chemical treatments indeed attacked the cellulose fibers and removed the silica from surface pores. The optimization of enzymatic hydrolysis of EFB's cellulosic fraction was performed with 0.5%–4% v/v of Cellic® CTec2/Novozymes, different EFB concentrations (5%–15%, w/v), and hydrolysis time (6–72 H). Optimization essays were carried out in Erlenmeyer flasks and also in a 1 L stirred tank reactor. After enzymatic hydrolysis, a hydrolysate with 66 g/L of glucose was achieved with 2.2% (v/v) Cellic® CTec2, 15% (m/v) acid/alkaline pretreated EFB after 39 H of hydrolysis. A gain of 11.2% was then obtained in the 1 L stirred tank promoted by the agitation (72.2 g/L glucose). The hydrolysate was employed in bioethanol production by a new isolate Candida pelliculosa CCT 7734 in a separate hydrolysis and fermentation process reaching 16.6 and 23.0 g/L of bioethanol through batch and fed‐batch operation, respectively. An integrated biorefinery process was developed for EFB processing chain.
Biodegradable zinc oxide composite scaffolds promote osteochondral differentiation of mesenchymal stem cells
Authors: Khader Ateka , Arinzeh Treena Livingston
Published: September 2019

Osteoarthritis (OA) involves the degeneration of articular cartilage and subchondral bone. The capacity of articular cartilage to repair and regenerate is limited. A biodegradable, fibrous scaffold containing zinc oxide (ZnO) was fabricated and evaluated for osteochondral tissue engineering applications. ZnO has shown promise for a variety of biomedical applications but has had limited use in tissue engineering. Composite scaffolds consisted of ZnO nanoparticles embedded in slow degrading, polycaprolactone to allow for dissolution of zinc ions over time. Zinc has well‐known insulin‐mimetic properties and can be beneficial for cartilage and bone regeneration. Fibrous ZnO composite scaffolds, having varying concentrations of 1–10 wt.% ZnO, were fabricated using the electrospinning technique and evaluated for human mesenchymal stem cell (MSC) differentiation along chondrocyte and osteoblast lineages. Slow release of the zinc was observed for all ZnO composite scaffolds. MSC chondrogenic differentiation was promoted on low percentage ZnO composite scaffolds as indicated by the highest collagen type II production and expression of cartilage‐specific genes, while osteogenic differentiation was promoted on high percentage ZnO composite scaffolds as indicated by the highest alkaline phosphatase activity, collagen production, and expression of bone‐specific genes. This study demonstrates the feasibility of ZnO‐containing composites as a potential scaffold for osteochondral tissue engineering.
The impact of sialylation linkage‐type on the pharmacokinetics of recombinant butyrylcholinesterases
Authors: Chung Cheng‐Yu , Wang Qiong , Yang Shuang , Chough Sandra , Seo Younji , Cipollo John F. , Balthasar Joseph P. , Betenbaugh Michael J.
Published: September 2019

Chinese hamster ovary (CHO) cells typically produce glycoproteins with N‐glycans terminating in α‐2,3 sialylation. Human cells produce glycoproteins that include α‐2,3 and α‐2,6 sialic acids. To examine the impact of altering protein sialylation on pharmacokinetic properties, recombinant human butyrylcholinesterase (BChE) was produced in CHO cells by knocking out the α‐2,3 sialyltransferase genes followed by overexpression of the α‐2,6 sialyltransferase (26BChE) enzyme. The N‐glycan composition of 26BChE was compared to BChE with α‐2,3 sialylation (23BChE) derived from wild‐type CHO cells. Both 23BChE and 26BChE exhibited comparable antennarity distributions with bi‐antennary di‐sialylated glycans representing the most abundant glycoform. CD‐1 mice were intravenously injected with the 23BChE or 26BChE, and residual BChE activities from blood collected at various time points for pharmacokinetic analyses. Although 23BChE contained a slightly lower initial sialylation level compared to 26BChE, the molecule exhibited higher residual activity between 5 and 24 hr postinjection. Pharmacokinetic analyses indicated that 23BChE exhibited an increase in area under the curve and a lower volume of distribution at steady state than that of 26BChE. These findings suggest that the type of sialylation linkage may play a significant role in the pharmacokinetic behavior of a biotherapeutic when tested in in vivo animal models.
“Out on the edge of my comfort”: Trainee counsellor/psychotherapists' experiences of spirituality in therapy—A qualitative exploration
Authors: Woodhouse Rebekah , Hogan Kevin F.
Published: September 2019

The integration of spirituality into counselling and psychotherapy poses complex challenges. Personal spirituality, professional competency and ethical considerations may impact on trainees' experiences of integrating spirituality into therapy. This study adopted an inductive, qualitative approach to explore trainee counsellor/psychotherapists' experiences and perceptions of integrating spirituality into therapy. Six trainee counsellors and psychotherapists were recruited using purposive sampling from a professional counsellor and psychotherapist training institution in the UK. In‐depth, semi‐structured interviews were conducted, audio‐recorded and transcribed verbatim. Thematic analysis of the interviews revealed two overarching themes: spirituality provides support but needs a warning; and spirituality is relevant but undervalued. These themes encompass a wide range of trainee concerns associated with integrating spirituality into therapy. Participants reported that they felt unprepared to work therapeutically with clients' spiritual beliefs. However, the value of spirituality in providing support to both the trainee and their clients was highlighted by several participants. Some participants described integrating clients' spirituality as having a positive impact on the therapeutic relationship, but often felt threatening to the trainee. This research has implications that are important for counselling and psychotherapy training and developing enhanced consideration of client spirituality and the interpersonal environment in which therapy is delivered.
Carbon Cloth‐based Hybrid Materials as Flexible Electrochemical Supercapacitors
Authors: Mishra Amit , Shetti Nagaraj P. , Basu Soumen , Raghava Reddy Kakarla , Aminabhavi Tejraj M.
Published: September 2019

Carbon cloths are the important materials composed of woven carbon fibres having the diameters in the range of 5–10 μm. These materials have been investigated for innumerable applications such as supercapacitors (symmetric and asymmetric), batteries, solar cells, and catalysis. They are found to be the best supports as supercapacitive materials by providing high surface area, conductivity and flexibility compared to much widely used substrate materials such as Ni foam and 1D Fe nanowires. High conductivity and surface area of carbon cloths enable ion diffusion and cause decrease in charge transfer resistance, resulting in an increase of specific capacitance of specific electrodes. Several supercapacitive metal oxides, chalcogenides, phosphides, MXenes, carbon nanotubes, graphene, and conductive polymers have been incorporated into carbon cloths to improve their energy storage activity. Further modification of carbon cloth surface via oxidation, doping and by the growth of different nanostructures is also helpful as it increases the electroactive surface area necessary for electrochemical interaction. The present review mainly focuses on the development of flexible supercapacitors using carbon cloth‐based substrate materials. Such flexible supercapacitors can be further utilized for an uninterrupted and steady power supply to wearable and portable electronic devices.
Chinese nonmedicinal herbal diet and risk of nasopharyngeal carcinoma: A population‐based case‐control study
Authors: Lin Chuyang , Cao Su‐Mei , Chang Ellen T. , Liu Zhiwei , Cai Yonglin , Zhang Zhe , Chen Guomin , Huang Qi‐Hong , Xie Shang‐Hang , Zhang Yu , Yun Jingping , Jia Wei‐Hua , Zheng Yuming , Liao Jian , Chen Yufeng , Lin Longde , Liu Qing , Ernberg Ingemar , Huang Guangwu , Zeng Yi , Zeng Yi‐Xin , Adami Hans‐Olov , Ye Weimin
Published: September 2019

Background

An association between a nonmedicinal herbal diet and nasopharyngeal carcinoma (NPC) has often been hypothesized but never thoroughly investigated.

Methods

This study enrolled a total of 2469 patients with incident NPC and 2559 population controls from parts of Guangdong and Guangxi Provinces in southern China between 2010 and 2014. Questionnaire information was collected on the intake of traditional herbal tea and herbal soup as well as the specific herbal plants used in soups and other potentially confounding lifestyle factors. Multivariate logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the NPC risk in association with herbal tea and soup intake.

Results

Ever consumption of herbal tea was not associated with NPC risk (OR, 1.03; 95% CI, 0.91‐1.17). An inverse association was observed for NPC among ever drinkers of herbal soup (OR, 0.78; 95% CI, 0.67‐0.90) but without any monotonic trend with an increasing frequency or duration of herbal soup consumption. Inverse associations with NPC risk were detected with 9 herbal plants used in herbal soup, including Ziziphus jujuba, Fructus lycii, Codonopsis pilosula, Astragalus membranaceus, Semen coicis, Smilax glabra, Phaseolus calcaratus, Morinda officinalis, and Atractylodes macrocephala (OR range, 0.31‐0.79).

Conclusions

Consuming herbal soups including specific plants, but not herbal tea, was inversely associated with NPC. If replicated, these results might provide potential for NPC prevention in endemic areas.
Beer's Law‐Why Integrated Absorbance Depends Linearly on Concentration
Authors: Mayerhöfer Thomas G. , Pipa Andrei V. , Popp Jürgen
Published: September 2019

As derived by Max Planck in 1903 from dispersion theory, Beer's law has a fundamental limitation. The concentration dependence of absorbance can deviate from linearity, even in the absence of any interactions or instrumental nonlinearities. Integrated absorbance, not peak absorbance, depends linearly on concentration. The numerical integration of the absorbance leads to maximum deviations from linearity of less than 0.1 %. This deviation is a consequence of a sum rule that was derived from the Kramers‐Kronig relations at a time when the fundamental limitation of Beer's law was no longer mentioned in the literature. This sum rule also links concentration to (classical) oscillator strengths and thereby enables the use of dispersion analysis to determine the concentration directly from transmittance and reflectance measurements. Thus, concentration analysis of complex samples, such as layered and/or anisotropic materials, in which Beer's law cannot be applied, can be achieved using dispersion analysis.
Self‐Assembly of PEGylated Diphenylalanines into Photoluminescent Fibrillary Aggregates
Authors: Diaferia Carlo , Roviello Valentina , Morelli Giancarlo , Accardo Antonella
Published: September 2019

Diphenylalanine (FF) represents one of the most studied self‐assembling peptides. As a consequence of non‐covalent interactions (aromatic stacking and hydrogen bonds), FF is able to generate different nanoarchitectures, proposed in the last years as innovative tools for several applications. The identification of the relationship between the chemical building block composition and the supramolecular structure of final material is the objective of intense research. Different FF analogues were synthetized and studied. At the state of art, in the high number of FF derivatives, PEGylation has not been studied yet, notwithstanding its role has been demonstrated for longer poly‐phenylalanine peptides. Herein, we describe the synthesis and the supramolecular behavior of two PEGylated‐FF derivatives, PEG2‐FF and PEG6‐FF, in which the zwitterionic FF has been derivatized at the N‐terminus with two or six ethoxylic moieties, respectively. Spectroscopic methodologies (fluorescence, circular dichroism, Fourier transform infrared) allowed the identification of their secondary structure and the calculation of the critical aggregation concentration. PEGylation of the dipeptide induces a modification of the conformational organization from nanotubes with hexagonal symmetry to β‐sheet rich fibrils. This structural organization confers photoluminescence features to the supramolecular structures.
Creation of Discrete 1D Microstructures: Directional Dissociation from the Ends of a Metastable Supramolecular Polymer
Authors: Kanzaki Chisako , Nakadozono Takuya , Numata Munenori
Published: September 2019

One major concern in supramolecular chemistry is how to place different intermolecular interactions in a desired position, especially at the terminal ends, of 1D structures. A solution to the problem is co‐assembly in microflow. We demonstrate that kinetic co‐assembly of two kinds of amphiphilic oligo(p‐phenylenevinylene) molecules with different amide groups result in metastable nanofibers where stronger hydrogen‐bonding interactions are regularly inserted as stabilizing wedges. It is found that decomposition of the nanofibers from the ends is suppressed at the wedges, leading to the creation of discrete 1D structures with capped ends (length dispersity Lw/Ln≤1.2), which act as a micrometer‐sized building blocks that can be used for further hierarchical assembly.
International Coherence of Pediatric Drug Labeling for Drug Safety: Comparison of Approved Labels in Korea and the United States
Authors: Song Yun‐Kyoung , Han Nayoung , Burckart Gilbert J. , Oh Jung Mi
Published: September 2019

The objective of this study was to analyze information on pediatric use in Korean drug product labels and compare it with that in US Food and Drug Administration (FDA) labeling information. Prescription information on pediatric use contained in the commonly used drugs’ product labels approved by Korean government was compared with that approved by the FDA. Among the top 50 commonly prescribed drugs, 20 drugs were deemed to have insufficient prescribing information in Korean drug labels. Pediatric prescribing information regarding indication, approved age, formulations, and safety was insufficient in Korean drug labels compared with those in the FDA. Most important, the adverse events frequently reported in Korean children were not sufficiently presented in drug labels. In conclusion, this study highlights the urgent need for the Korean regulatory agency to encourage and accelerate research and development to increase the extent of pediatric prescribing information to be added to drug labels to promote appropriate drug prescribing for children.
PharmVar GeneFocus: CYP2D6
Authors: Nofziger Charity , Turner Amy J. , Sangkuhl Katrin , Whirl‐Carrillo Michelle , Agúndez José A.G. , Black John L. , Dunnenberger Henry M. , Ruano Gualberto , Kennedy Martin A. , Phillips Michael S. , Hachad Houda , Klein Teri E. , Gaedigk Andrea
Published: September 2019

The Pharmacogene Variation Consortium (PharmVar) provides nomenclature for the highly polymorphic human CYP2D6 gene locus. CYP2D6 genetic variation impacts the metabolism of numerous drugs and, thus, can impact drug efficacy and safety. This GeneFocus provides a comprehensive overview and summary of CYP2D6 genetic variation and describes how the information provided by PharmVar is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).
The potential of zooplankton in constraining chytrid epidemics in phytoplankton hosts
Authors: Frenken Thijs , Miki Takeshi , Kagami Maiko , Van de Waal Dedmer B. , Van Donk Ellen , Rohrlack Thomas , Gsell Alena S.
Published: September 2019

Fungal diseases threaten natural and man‐made ecosystems. Chytridiomycota (chytrids) infect a wide host range, including phytoplankton species that form the basis of aquatic food webs and produce roughly half of Earth's oxygen. However, blooms of large or toxic phytoplankton form trophic bottlenecks, as they are inedible to zooplankton. Chytrids infecting inedible phytoplankton provide a trophic link to zooplankton by producing edible zoospores of high nutritional quality. By grazing chytrid zoospores, zooplankton may induce a trophic cascade, as a decreased zoospore density will reduce new infections. Conversely, fewer infections will not produce enough zoospores to sustain long‐term zooplankton growth and reproduction. This intricate balance between zoospore density necessary for zooplankton energetic demands (growth/survival), and the loss in new infections (and thus new zoospores) because of grazing was tested empirically. To this end, we exposed a cyanobacterial host (Planktothrix rubescens) infected by a chytrid (Rizophydium megarrhizum) to a grazer density gradient (the rotifer Keratella cf. cochlearis). Rotifers survived and reproduced on a zoospore diet, but the Keratella population growth was limited by the amount of zoospores provided by chytrid infections, resulting in a situation where zooplankton survived but were restricted in their ability to control disease in the cyanobacterial host. We subsequently developed and parameterized a dynamical food‐chain model using an allometric relationship for clearance rate to assess theoretically the potential of different‐sized zooplankton groups to restrict disease in phytoplankton hosts. Our model suggests that smaller‐sized zooplankton may have a high potential to reduce chytrid infections on inedible phytoplankton. Together, our results point out the complexity of three‐way interactions between hosts, parasites, and grazers and highlight that trophic cascades are not always sustainable and may depend on the grazer's energetic demand.
Photochemical Rearrangements in Heterocyclic Chemistry
Authors: Lefebvre Corentin , Fortier Lucas , Hoffmann Norbert
Published: September 2019

Heterocyclic compounds play an important role in many domains of chemistry. They are important structural elements in bioactive compounds. Photochemical reactions enable transformations of such compounds in a very convenient way. In many cases no chemical reagent is used. Members of one compound family can be transformed into members of another one. Three important types of photochemical rearrangements with heterocyclic compounds are discussed: Photochemical heteroatom isomerization involving heteroatoms and substituents, photochemical reactions involving hydrogen atom transfer (HAT) and photochemical electrocyclization.
Heterogeneity and netting efficiency under central clearing: A stochastic network analysis
Authors: Hwang Injun , Kim Baeho
Published: September 2019

This paper examines the effect of heterogeneity in clearing members’ exposure management practices under central clearing. Our network model specifies the dynamics of prenetted interbank exposures to shape interdependent exposure distributions beyond normality. Employing over‐the‐counter derivatives market data from the U.S. Office of the Comptroller of the Currency, our simulation results indicate that heterogeneity in bank‐to‐bank exposure dynamics is systemically desirable, while the entire system benefits more from the central clearing in more homogeneous environments. Policymakers should incentivize individual clearing members to enhance resiliency and stability in counterparty exposure management to maximize netting efficiency under central clearing.