bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies for Dendrite‐Free Anode in Aqueous Rechargeable Zinc Ion Batteries
Authors: Cao Ziyi , Zhuang Peiyuan , Zhang Xiang , Ye Mingxin , Shen Jianfeng , Ajayan Pulickel M.
Published: June 2020

Ongoing interest is focused on aqueous zinc ion batteries (ZIBs) for mass‐production energy storage systems as a result of their affordability, safety, and high energy density. Ensuring the stability of the electrode/electrolyte interface is of particular importance for prolonging the cycling ability to meet the practical requirements of rechargeable batteries. Zinc anodes exhibit poor cycle life and low coulombic efficiency, stemming from the severe dendrite growth, and irreversible byproducts such as H2 and inactive ZnO. Great efforts have recently been devoted to zinc anode protection for designing high‐performance ZIBs. However, the intrinsic origins of zinc plating/striping are poorly understood, which greatly delay its potential applications. Rather than focusing on battery metrics, this review delves deeply into the underlying science that triggers the deposition/dissolution of zinc ions. Furthermore, recent advances in modulating the zinc coordination environment, uniforming interfacial electric fields, and inducing zinc deposition are highlighted and summarized. Finally, perspectives and suggestions are provided for designing highly stable zinc anodes for the industrialization of the aqueous rechargeable ZIBs in the near future.
Assessing inbred–hybrid relationships for developing drought‐tolerant provitamin A–quality protein maize hybrids
Authors: Obeng‐Bio Ebenezer , Badu‐Apraku Baffour , Ifie Beatrice Elohor , Danquah Agyemang , Blay Essie T. , Dadzie Mustapha Abu
Published: June 2020

Drought‐tolerant early‐maturing maize (Zea mays L.) inbred lines with high levels of provitamin A (PVA) and quality protein (QPM) are urgently needed for development of superior hybrids to mitigate malnutrition and to intensify maize production and productivity in sub‐Saharan Africa (SSA). This study was designed to identify early‐maturing inbred lines with combined tolerance to drought, elevated tryptophan, and PVA contents; to examine inbred–hybrid relationships for tryptophan and PVA accumulation; and to select hybrids with outstanding grain yield (GY) performance. A total of 64 inbred lines and six checks, plus 96 hybrids and four checks, were evaluated under drought and well‐watered environments in Nigeria for 2 yr. Eighteen parental lines and 54 derived hybrids were assayed for tryptophan and PVA contents. Ten drought‐tolerant inbred lines with high tryptophan and elevated PVA levels were identified in the top 10 hybrid combinations across managed drought and well‐watered conditions. The inbred–hybrid relationship was significant for GY under each and across the two contrasting environments. Significant average heterosis was found for tryptophan and PVA under well‐watered conditions. This indicated that the selected inbred lines could be used for developing high‐yielding PVA‐QPM hybrids tolerant to drought stress in SSA. The 10 top‐performing PVA‐QPM hybrids identified are being extensively evaluated in different locations and subsequently in on‐farm trials for commercialization throughout SSA.
Corporate Dispute Resolution Strategies to Make Mediation and Arbitration Better Alternatives
Authors: Veasey Norman
Published: June 2020

This article is centered on the desirability of instilling a particular culture in corporate decision making on responsible and effective dispute resolution methods.
Arbitration Privacy and Confidentiality In the Age of (Coronavirus) Technology
Authors: Singer David C.
Published: June 2020

Privacy is a hallmark attribute of arbitration.
Complaint Handling: The Technique that (Almost) Nobody In the Conflict Resolution World Talks About
Authors: Samuel Adam
Published: June 2020

In the dispute resolution world, there is a tendency to see a dispute and then a variety of techniques that one can use to resolve it: mediation, negotiation, arbitration, litigation and numerous other options.
A Self‐Consistent Model for Sorption and Transport in Polyimide‐Derived Carbon Molecular Sieve Gas Separation Membranes
Authors: Sanyal Oishi , Hays Samuel S. , León Nicholas E. , Guta Yoseph A. , Itta Arun K. , Lively Ryan P. , Koros William J.
Published: June 2020

Demand for energy‐efficient gas separations exists across many industrial processes, and membranes can aid in meeting this demand. Carbon molecular sieve (CMS) membranes show exceptional separation performance and scalable processing attributes attractive for important, similar‐sized gas pairs. Herein, we outline a mathematical and physical framework to understand these attributes. This framework shares features with dual‐mode transport theory for glassy polymers; however, physical connections to CMS model parameters differ from glassy polymer cases. We present evidence in CMS membranes for a large volume fraction of microporous domains characterized by Langmuir sorption in local equilibrium with a minority continuous phase described by Henry's law sorption. Using this framework, expressions are provided to relate measurable parameters for sorption and transport in CMS materials. We also outline a mechanism for formation of these environments and suggest future model refinements.
Rational Design of Microporous MOFs with Anionic Boron Cluster Functionality and Cooperative Dihydrogen Binding Sites for Highly Selective Capture of Acetylene
Authors: Zhang Yuanbin , Hu Jianbo , Krishna Rajamani , Wang Lingyao , Yang Lifeng , Cui Xili , Duttwyler Simon , Xing Huabin
Published: June 2020

Separation of acetylene (C2H2) from carbon dioxide (CO2) or ethylene (C2H4) is important in industry but limited by the low capacity and selectivity owing to their similar molecular sizes and physical properties. Herein, we report two novel dodecaborate‐hybrid metal–organic frameworks, MB12H12(dpb)2 (termed as BSF‐3 and BSF‐3‐Co for M=Cu and Co), for highly selective capture of C2H2. The high C2H2 capacity and remarkable C2H2/CO2 selectivity resulted from the unique anionic boron cluster functionality as well as the suitable pore size with cooperative proton‐hydride dihydrogen bonding sites (B−Hδ−⋅⋅⋅Hδ+−C≡C−Hδ+⋅⋅⋅Hδ−−B). This new type of C2H2‐specific functional sites represents a fresh paradigm distinct from those in previous leading materials based on open metal sites, strong electrostatics, or hydrogen bonding.
Insect‐Associated Bacteria Assemble the Antifungal Butenolide Gladiofungin by Non‐Canonical Polyketide Chain Termination
Authors: Niehs Sarah P. , Kumpfmüller Jana , Dose Benjamin , Little Rory F. , Ishida Keishi , Flórez Laura V. , Kaltenpoth Martin , Hertweck Christian
Published: June 2020

Genome mining of one of the protective symbionts (Burkholderia gladioli) of the invasive beetle Lagria villosa revealed a cryptic gene cluster that codes for the biosynthesis of a novel antifungal polyketide with a glutarimide pharmacophore. Targeted gene inactivation, metabolic profiling, and bioassays led to the discovery of the gladiofungins as previously‐overlooked components of the antimicrobial armory of the beetle symbiont, which are highly active against the entomopathogenic fungus Purpureocillium lilacinum. By mutational analyses, isotope labeling, and computational analyses of the modular polyketide synthase, we found that the rare butenolide moiety of gladiofungins derives from an unprecedented polyketide chain termination reaction involving a glycerol‐derived C3 building block. The key role of an A‐factor synthase (AfsA)‐like offloading domain was corroborated by CRISPR‐Cas‐mediated gene editing, which facilitated precise excision within a PKS domain.
Diradical Organic One‐Dimensional Polymers Synthesized on a Metallic Surface
Authors: Sánchez‐Grande Ana , Urgel José I. , Cahlík Aleš , Santos José , Edalatmanesh Shayan , Rodríguez‐Sánchez Eider , Lauwaet Koen , Mutombo Pingo , Nachtigallová Dana , Nieman Reed , Lischka Hans , de la Torre Bruno , Miranda Rodolfo , Gröning Oliver , Martín Nazario , Jelínek Pavel , Écija David
Published: June 2020

We report on the synthesis and characterization of atomically precise one‐dimensional diradical peripentacene polymers on a Au(111) surface. By means of high‐resolution scanning probe microscopy complemented by theoretical simulations, we provide evidence of their magnetic properties, which arise from the presence of two unpaired spins at their termini. Additionally, we probe a transition of their magnetic properties related to the length of the polymer. Peripentacene dimers exhibit an antiferromagnetic (S=0) singlet ground state. They are characterized by singlet–triplet spin‐flip inelastic excitations with an effective exchange coupling (Jeff) of 2.5 meV, whereas trimers and longer peripentacene polymers reveal a paramagnetic nature and feature Kondo fingerprints at each terminus due to the unpaired spin. Our work provides access to the precise fabrication of polymers featuring diradical character which are potentially useful in carbon‐based optoelectronics and spintronics.
Structural Elucidation of the Mechanism of Molecular Recognition in Chiral Crystalline Sponges
Authors: Zhang Shi‐Yuan , Fairen‐Jimenez David , Zaworotko Michael J.
Published: June 2020

To gain insight into chiral recognition in porous materials we have prepared a family of fourth generation chiral metal–organic frameworks (MOFs) that have rigid frameworks and adaptable (flexible) pores. The previously reported parent material, [Co2(S‐mandelate)2(4,4′‐bipyridine)3](NO3)2, CMOM‐1S, is a modular MOF; five new variants in which counterions (BF4−, CMOM‐2S) or mandelate ligands are substituted (2‐Cl, CMOM‐11R; 3‐Cl, CMOM‐21R; 4‐Cl, CMOM‐31R; 4‐CH3, CMOM‐41R) and the existing CF3SO3−variant CMOM‐3Sare studied herein. Fine‐tuning of pore size, shape, and chemistry afforded a series of distinct host–guest binding sites with variable chiral separation properties with respect to three structural isomers of phenylpropanol. Structural analysis of the resulting crystalline sponge phases revealed that host–guest interactions, guest–guest interactions, and pore adaptability collectively determine chiral discrimination.
Design of Optical‐Imaging Probes by Screening of Diverse Substrate Libraries Directly in Disease‐Tissue Extracts
Authors: Tholen Martina , Yim Joshua J. , Groborz Katarzyna , Yoo Euna , Martin Brock A. , van den Berg Nynke S. , Drag Marcin , Bogyo Matthew
Published: June 2020

Fluorescently quenched probes that are specifically activated in the cancer microenvironment have great potential application for diagnosis, early detection, and surgical guidance. These probes are often designed to target specific enzymes associated with diseases by direct optimization using single purified enzymes. However, this can result in painstaking chemistry efforts to produce a probe with suboptimal performance when applied in vivo. We describe here an alternate, unbiased activity‐profiling approach in which whole tissue extracts are used to directly identify optimal peptide sequences for probe design. Screening of tumor extracts with a hybrid combinatorial substrate library (HyCoSuL) identified a combination of natural and non‐natural amino‐acid residues that was used to generate highly efficient tumor‐specific probes. This new strategy simplifies and enhances the process of probe optimization without any a priori knowledge of enzyme targets and has the potential to be applied to diverse disease states using clinical or animal‐model tissue samples.
In Situ Dispersion of Palladium on TiO2 During Reverse Water–Gas Shift Reaction: Formation of Atomically Dispersed Palladium
Authors: Nelson Nicholas C. , Chen Linxiao , Meira Debora , Kovarik Libor , Szanyi János
Published: June 2020

The application of single‐atom catalysts (SACs) to high‐temperature hydrogenation requires materials that thermodynamically favor metal atom isolation over cluster formation. We demonstrate that Pd can be predominantly dispersed as isolated atoms onto TiO2 during the reverse water–gas shift (rWGS) reaction at 400 °C. Achieving atomic dispersion requires an artificial increase of the absolute TiO2 surface area by an order of magnitude and can be accomplished by physically mixing a precatalyst (Pd/TiO2) with neat TiO2 prior to the rWGS reaction. The in situ dispersion of Pd was reflected through a continuous increase of rWGS activity over 92 h and supported by kinetic analysis, infrared and X‐ray absorption spectroscopies and scanning transmission electron microscopy. The thermodynamic stability of Pd under high‐temperature rWGS conditions is associated with Pd‐Ti coordination, which manifests upon O‐vacancy formation, and the artificial increase in TiO2 surface area.
Comparative study on the properties of cross‐linked cellulose nanocrystals/chitosan film composites with conventional heating and microwave curing
Authors: Gan Pei Gie , Sam Sung Ting , Abdullah Muhammad Faiq , Omar Mohd Firdaus , Tan Wai Kian
Published: June 2020

Cross‐linking of chitosan film composites was carried out by using conventional heating and microwave curing methods in this study. Non‐cross‐linked and glutaraldehyde (GA) cross‐linked neat chitosan and cellulose nanocrystals (CNC)/chitosan film composites were cured by either conventional oven heating or microwave irradiation. Tensile strength and Young's modulus of chitosan composites were enhanced significantly by the addition of CNC and GA especially for the microwave‐cured samples. The changes in chemical interaction of the chitosan film composites was determined by Fourier transform infrared (FTIR) spectroscopy. The microwave‐cured GA‐cross‐linked chitosan film composites were more thermally stable than non‐cross‐linked and conventionally heated GA‐cross‐linked chitosan film composites due to the formation of a more stable structure between GA and chitosan. Nevertheless, the reduced antimicrobial efficacy of film composites against Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae was observed in cross‐linked film composites compared with non‐cross‐linked composites.
The Lifebox Surgical Headlight Project: engineering, testing, and field assessment in a resource-constrained setting
Authors: Starr N , Panda N , Johansen E W , Forrester J A , Wayessa E , Rebollo D , August A , Fernandez K , Bitew S , Mammo T Negussie , Weiser T G
Published: June 2020

Background

Poor surgical lighting represents a major patient safety issue in low-income countries. This study evaluated device performance and undertook field assessment of high-quality headlights in Ethiopia to identify critical attributes that might improve safety and encourage local use.

Methods

Following an open call for submissions (December 2018 to January 2019), medical and technical (non-medical) headlights were identified for controlled specification testing on 14 prespecified parameters related to light quality/intensity, mounting and battery performance, including standardized illuminance measurements over time. The five highest-performing devices (differential illumination, colour rendering, spot size, mounting and battery duration) were distributed to eight Ethiopian surgeons working in resource-constrained facilities. Surgeons evaluated the devices in operating rooms, and in a comparative session rated each headlight in terms of performance and willingness to purchase.

Results

Of 25 submissions, eight headlights (6 surgical and 2 technical) met the criteria for full specification testing. Scores ranged from 8 to 12 (of 14), with differential performance in lighting, mounting and battery domains. Only two headlights met the illuminance parameters of more than 35 000 lux during initial testing, and no headlight satisfied all minimum specifications. Of the five headlights evaluated in Ethiopia, daily operation logbooks noted variability in surgeons' opinions of lighting quality (6–92 per cent) and spot size (0–92 per cent). Qualitative interviews also yielded important feedback, including preference for easy transport. Surgeons sought high quality with price sensitivity (using out-of-pocket funds) and identified the least expensive but high-functioning device as their first choice.

Conclusion

No device satisfied all the predetermined specifications, and large price discrepancies were critical factors leading surgeons' choices. The favoured device is undergoing modification by the manufacturer based on design feedback so an affordable, high-quality surgical headlight crafted specifically for the needs of resource-constrained settings can be used to improve surgical safety.
Transitioning undergraduate research from wet lab to the virtual in the wake of a pandemic
Authors: Chandrasekaran Arun Richard
Published: June 2020

The COVID‐19 outbreak has shut down universities, and teaching faculty have moved to online classrooms to address students. This change has been supported by numerous online teaching tools and development of virtual classrooms. Undergraduate research programs in the sciences and biochemistry/molecular biology teaching labs, however, are affected by this change due to inaccessibility to laboratories. This communication outlines three concepts to engage undergraduate students who are involved in research: (a) remote data analysis, (b) literature review and science writing, and (c) science journal clubs.
Are women eco‐friendly? Board gender diversity and environmental innovation
Authors: Nadeem Muhammad , Bahadar Stephen , Gull Ammar Ali , Iqbal Umer
Published: June 2020

As a result of recent climate change impacts, environmental sustainability has received enormous attention from scholars and policy makers. Environmental innovation is one of the major ways of acting in harmony with the environment, but it also requires a significant amount of resources and strong corporate commitment. As boards of directors have great influence over the strategic direction of firms and are responsible for corporate environmentalism, we examine the likely relationship between board gender diversity (BGD) and environmental innovation measured as process innovation and product innovation. Based on a relatively large dataset (10,334 firm‐year observations) of U.S. listed firms, we find that BGD has a significant positive association with environmental innovation. Furthermore, we also find that this relationship is more pronounced in less profitable firms and in environmentally sensitive industries. Our results remain robust to endogeneity issues and alternative proxies. We interpret our results under upper echelon and gender socialization theories and suggest important implications for policy makers.
Pulmonary intralobar sequestration associated with aspergillosis and aspiration
Authors: Zaccarini Daniel J. , El‐Zammar Ola
Published: June 2020

The pathogenesis of intralobar pulmonary sequestration is not completely understood, either representing a congenital or acquired process. The presence of fungal organisms and aspiration has both clinical and etiologic significance.
Transition‐Metal‐Mediated Modification of Biomolecules
Authors: Rodríguez Jessica , Martínez‐Calvo Miguel
Published: June 2020

The site‐selective modification of biomolecules has grown spectacularly in recent years. The presence of a large number of functional groups in a biomolecule makes its chemo‐ and regioselective modification a challenging goal. In this context, transition‐metal‐mediated reactions are emerging as a powerful tool owing to their unique reactivity and good functional group compatibility, allowing highly efficient and selective bioconjugation reactions that operate under mild conditions. This Minireview focuses on the current state of organometallic chemistry for bioconjugation, highlighting the potential of transition metals for the development of chemoselective and site‐specific methods for functionalization of peptides, proteins and nucleic acids. The importance of the selection of ligands attached to the transition metal for conferring the desired chemoselectivity will be highlighted.
A Porous Mooncake‐Shaped Li4Ti5O12 Anode Material Modified by SmF3 and Its Electrochemical Performance in Lithium Ion Batteries
Authors: Wang Bo , Hu Sisi , Gu Lin , Zhang Di , Li Yazhao , Sun Huilan , Li Wen , Wang Qiujun
Published: June 2020

Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal–organic framework (MOF, Mil‐125) was used as a precursor and template to successfully synthesize the porous mooncake‐shaped Li4Ti5O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake‐shaped LTO material. The SmF3‐modified LTO maintained a porous mooncake‐shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+, reduce the polarization of electrode, decrease charge transfer impedance (Rct) and solid electrolyte interface impedance (Rsei), and increase the lithium ion diffusion coefficient (DLi), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake‐shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g−1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g−1), and shows a high retention rate of 96.4 % after 500 cycles at 5 C‐rate.
Investigating Ugi/Passerini Multicomponent Reactions for the Site‐Selective Conjugation of Native Trastuzumab**
Authors: Sornay Charlotte , Hessmann Steve , Erb Stéphane , Dovgan Igor , Ehkirch Anthony , Botzanowski Thomas , Cianférani Sarah , Wagner Alain , Chaubet Guilhem
Published: June 2020

Site‐selective modification of proteins has been the object of intense studies over the past decades, especially in the therapeutic field. Prominent results have been obtained with recombinant proteins, for which site‐specific conjugation is made possible by the incorporation of particular amino acid residues or peptide sequences. In parallel, methods for the site‐selective and site‐specific conjugation of native and natural proteins are starting to thrive, allowing the controlled functionalization of various types of amino acid residues. Pursuing the efforts in this field, we planned to develop a new type of site‐selective method, aiming at the simultaneous conjugation of two amino acid residues. We reasoned that this should give higher chances of developing a site‐selective strategy compared to the great majority of existing methods that solely target a single residue. We opted for the Ugi four‐centre three‐component reaction to implement this idea, with the aim of conjugating the side‐chain amine and carboxylate groups of two neighbouring lysine and aspartate/glutamate. Herein, we show that this strategy can give access to valuable antibody conjugates bearing several different payloads; furthermore, the approach limits the potential conjugation sites to only six on the model antibody trastuzumab.
Formation of Highly Efficient, Long‐Lived Charge Separated States in Star‐Shaped Ferrocene‐Diketopyrrolopyrrole‐Triphenylamine Donor–Acceptor–Donor Conjugates
Authors: Popli Charu , Jang Youngwoo , Patil Yuvraj , Misra Rajneesh , D'Souza Francis
Published: June 2020

The significance of multiple number of donor–acceptor entities on a central electron donor in a star‐shaped molecular system in improving light energy harvesting ability is reported. For this, donor–acceptor–donor type conjugates comprised up to three entities ferrocenyl (Fc)‐diketopyrrolopyrrole (DPP) onto a central triphenylamine (TPA), (4–6) by the Pd‐catalyzed Sonogashira cross‐coupling reactions have been newly synthesized and characterized. Donor–acceptor conjugates possessing diketopyrrolopyrrole (1 to 3 entities) onto the central triphenylamine, (1–3) served as reference dyads while monomeric DPP and Fc‐DPP served as control compounds. Both DPP and Fc‐DPP carrying conjugates exhibited red‐shifted absorption compared to their respective control compounds revealing existence of ground state interactions. Furthermore, DPP fluorescence in 4–6 was found to be quantitatively quenched while for 1–3, this property varied between 73–65 % suggesting occurrence moderate amounts of excited state events. The electrochemical investigations exhibited an additional low potential oxidation in the case of Fc‐DPP‐TPA based derivatives (4–6) owing to the presence of ferrocene unit(s). This was in addition to DPP and TPA redox peaks. Using spectral, electrochemical and computational studies, Gibbs free‐energy calculations were performed to visualize excited state charge separation (ΔGCS) in these donor–acceptor conjugates as a function of different number of Fc‐DPP entities. Formation of Fc+‐DPP.−‐TPA charge separated states (CSS) in the case of 4–6 was evident. Using spectroelectrochemical studies, spectrum of CSS was deduced. Finally, femtosecond transient absorption spectral studies were performed to gather information on excited state charge separation. Increasing the number of Fc‐DPP entities in 4–6 improved charge separation rates. Surprisingly, lifetime of the charge separated state, Fc+‐DPP.−‐TPA was found to persist longer with an increase in the number of Fc‐DPP entities in 4–6 as compared to Fc‐DPP‐control and simple DPP derived donor–acceptor conjugates in literature. This unprecedented result has been attributed to subtle changes in ΔGCS and ΔGCR and the associated electron coupling between different entities.
Natural dolapyrrolidone: Isolation and absolute stereochemistry of a substructure of bioactive peptides
Authors: Murakami Ayana , Hayashi Jun‐ichi , Igawa Kazunobu , Tsutsumi Miki , Tomooka Katsuhiko , Nagai Hiroshi , Nehira Tatsuo
Published: June 2020

During the course of our chemical analysis of the hydrophilic fractions from marine cyanobacterium Moorena producens, we have isolated natural dolapyrrolidone (Dpy, 1), a natural pyrrolidone derived from phenylalanine, for the first time as a single compound. Compound 1, with an (S)‐l absolute stereochemistry, was previously identified as a substructure that is common among several bioactive natural peptides. Surprisingly, the absolute stereochemistry of the isolated natural 1, determined through total synthesis, was (R)‐d. This result was unambiguously determined by HPLC analysis using a chiral stationary column by comparing the retention times of the natural 1 and authentic samples of synthetic enantiomers. To verify the unexpected result, the absolute stereochemistry of the natural 1 was confirmed by X‐ray crystallographic analysis of Pt‐complex derivative using the synthetic enantiomer.
DNA metabarcoding effectively quantifies diatom responses to nutrients in streams
Authors: Smucker Nathan J. , Pilgrim Erik M. , Nietch Christopher T. , Darling John A. , Johnson Brent R.
Published: June 2020

Nutrient pollution from human activities remains a common problem facing stream ecosystems. Identifying ecological responses to phosphorus and nitrogen can inform decisions affecting the protection and management of streams and their watersheds. Diatoms are particularly useful because they are a highly diverse group of unicellular algae found in nearly all aquatic environments and are sensitive responders to increased nutrient concentrations. Here, we used DNA metabarcoding of stream diatoms as an approach to quantifying effects of total phosphorus (TP) and total nitrogen (TN). Threshold indicator taxa analysis (TITAN) identified operational taxonomic units (OTUs) that increased or decreased along TP and TN gradients along with nutrient concentrations at which assemblages had substantial changes in the occurrences and relative abundances of OTUs. Boosted regression trees showed that relative abundances of gene sequence reads for OTUs identified by TITAN as low P, high P, low N, or high N diatoms had strong relationships with nutrient concentrations, which provided support for potentially using these groups of diatoms as metrics in monitoring programs. Gradient forest analysis provided complementary information by characterizing multi‐taxa assemblage change using multiple predictors and results from random forest models for each OTU. Collectively, these analyses showed that notable changes in diatom assemblage structure and OTUs began around 20 µg TP/L, low P diatoms decreased substantially and community change points occurred from 75 to 150 µg/L, and high P diatoms became increasingly dominant from 150 to 300 µg/L. Diatoms also responded to TN with large decreases in low N diatoms occurring from 280 to 525 µg TN/L and a transition to dominance by high N diatoms from 525–850 µg/L. These diatom responses to TP and TN could be used to inform protection efforts (i.e., anti‐degradation) and management goals (i.e., nutrient reduction) in streams and watersheds. Our results add to the growing support for using diatom metabarcoding in monitoring programs.
Disentangling the spatial and temporal causes of decline in a bird population
Authors: Plard Floriane , Arlettaz Raphaël , Jacot Alain , Schaub Michael
Published: June 2020

The difficulties in understanding the underlying reasons of a population decline lie in the typical short duration of field studies, the often too small size already reached by a declining population or the multitude of environmental factors that may influence population trend. In this difficult context, useful demographic tools such as integrated population models (IPM) may help disentangling the main reasons for a population decline. To understand why a hoopoe Upupa epops population has declined, we followed a three step model analysis. We built an IPM structured with respect to habitat quality (approximated by the expected availability of mole crickets, the main prey in our population) and estimated the contributions of habitat‐specific demographic rates to population variation and decline. We quantified how much each demographic rate has decreased and investigated whether habitat quality influenced this decline. We tested how much weather conditions and research activities contributed to the decrease in the different demographic rates. The decline of the hoopoe population was mainly explained by a decrease in first‐year apparent survival and a reduced number of fledglings produced, particularly in habitats of high quality. Since a majority of pairs bred in habitats of the highest quality, the decrease in the production of locally recruited yearlings in high‐quality habitat was the main driver of the population decline despite a homogeneous drop of recruitment across habitats. Overall, the explanatory variables we tested only accounted for 19% of the decrease in the population growth rate. Among these variables, the effects of spring temperature (49% of the explained variance) contributed more to population decline than spring precipitation (36%) and research activities (maternal capture delay, 15%). This study shows the power of IPMs for identifying the vital rates involved in population declines and thus paves the way for targeted conservation and management actions.
Functional cascading and abstracted energy model in systems engineering and model‐based development
Authors: Nakamura Yukinobu , Hayama Nobuhiro , Yamamoto Toru
Published: June 2020

Systems engineering (SE) and model‐based development (MBD) attract attention from manufacturers to produce more complex products with less rework in order to satisfy higher demands. However, concrete methodology is not defined well. This paper proposes a methodology of target assignment with respect to a special functional cascading for integrated atchitectural products. This paper also proposes “abstracted energy model” for assignment in top layer in the cascade. An example for air conditioner development demonstrates the efficiency of this methodology.
A translucent box: interpretable machine learning in ecology
Authors: Lucas Tim C. D.
Published: June 2020

Machine learning has become popular in ecology but its use has remained restricted to predicting, rather than understanding, the natural world. Many researchers consider machine learning algorithms to be a black box. These models can, however, with careful examination, be used to inform our understanding of the world. They are translucent boxes. Furthermore, the interpretation of these models can be an important step in building confidence in a model or in a specific prediction from a model. Here I review a number of techniques for interpreting machine learning models at the level of the system, the variable, and the individual prediction as well as methods for handling non‐independent data. I also discuss the limits of interpretability for different methods and demonstrate these approaches using a case example of understanding litter sizes in mammals.
Numerical evaluation and the effects of geometrical and operational parameters on thermal performance of the shell and double coil tube heat exchanger
Authors: Noorbakhsh Mehdi , Pourfallah Mohsen , Ajarostaghi Seyed S. M. , Zaboli Mohammad
Published: June 2020

Heat exchangers are extensively used in various industries. In this study, the impact of geometric and flow parameters on the performance of a shell and double helical coil heat exchanger is studied numerically. The investigated geometric parameters include external coil pitch, internal coil pitch, internal coil diameter, and coil diameter. The influences of considered geometrical parameters are analyzed on the output temperature of the hot and cold fluid, convective heat transfer coefficient, pressure drop, and average Nusselt number. Water is considered as working fluid in both shell and tube. As an innovation, double helical coils are used instead of one in the heat exchanger. To compare the obtained results accurately, in each section, the heat transfer area (coil outer surface) is kept constant in all models. The results show that the geometrical parameters of double helical coils significantly affect the heat transfer rate.
Spiraeoside protects human cardiomyocytes against high glucose‐induced injury, oxidative stress, and apoptosis by activation of PI3K/Akt/Nrf2 pathway
Authors: Liu Hongyang , Zhang Zhiyong , Zhang Lei , Yao Xinliang , Zhong Xiaoming , Cheng Guanchang , Wang Lefeng , Wan Qilin
Published: June 2020

The present study aimed to explore the effect of spiraeoside, an active quercetin glucoside, on diabetic cardiomyopathy in vitro. Our results showed that spiraeoside attenuated high glucose (HG)‐induced reduction of cell viability and increased myocardial enzymes lactate dehydrogenase and aspartate aminotransferase in AC16 cells. Spiraeoside exerted antioxidant activity in HG‐induced AC16 cells as spiraeoside inhibited reactive oxygen species and malondialdehyde production and increased activities of superoxide dismutase, glutathione peroxidase, and catalase. Spiraeoside prevented HG‐induced apoptosis of AC16 cells. HG stimulation‐caused the decrease in the expression levels of p‐Akt, nuclear Nrf2, and HO‐1 was elevated after spiraeoside treatment in AC16 cells. However, the effects of spiraeoside were reversed by LY294002. In conclusion, spiraeoside protected AC16 cells against HG‐induced oxidative stress, cell injury, and apoptosis. The protective effect of spiraeoside was regulated by the PI3K/Akt/Nrf2 signaling pathway.
The endoplasmic reticulum stress induced by tunicamycin affects the viability and autophagy activity of chondrocytes
Authors: Wu Hao , Meng Zhichao , Jiao Yang , Ren Yali , Yang Xin , Liu Heng , Wang Rui , Cui Yunpeng , Pan Liping , Cao Yongping
Published: June 2020

Osteoarthritis (OA) is attributed to a reduction in chondrocytes within joint cartilage, and research has shown that endoplasmic reticulum (ER) stress and autophagy play important roles in the survival of chondrocytes. However, the relationship between ER stress and autophagy in chondrocytes remains unclear. In this study, we investigated the changes in apoptotic and autophagic activity in chondrocytes under ER stress. Following treatment with tunicamycin, the rate of apoptosis among chondrocytes increased. Western blot analysis showed the levels of unfolded protein response (UPR) related proteins increased, followed by elevated expression of light chain 3B‐II (LC3B‐II) and Beclin‐1. An ultrastructural investigation showed that a large number of pre‑autophagosomal structures or autophagosomes formed under tunicamycin treatment. However, the autophagy activity was significantly inhibited in chondrocytes after suppression of GRP78 by siRNA. The apoptosis ratio of chondrocytes pre‐treated with 3‐methyladenine was much higher than that of normal chondrocytes after exposure to tunicamycin. Our study revealed that the tunicamycin‐induced persistent UPR expression led to apoptosis of chondrocytes and activation of autophagy incorporation with GRP78. Blocking autophagy accelerated the apoptosis induced by ER stress, which confirmed the protective function of autophagy in the homeostasis of chondrocytes. These findings advance our understanding of chondrocyte apoptosis and provide potential molecular targets for preventing apoptotic death of chondrocytes.
The secretome from embryonic stem cell cardiomyogenesis: Same signals, different cellular feedbacks
Authors: Robert Anny W. , Stimamiglio Marco A.
Published: June 2020

Ischemic heart diseases are a global health problem that requires the search for alternative therapies to the current treatments. Thus, an understanding of how cardiomyogenic signals can affect cellular behavior would allow us to create strategies to improve the cell recovery in damaged tissues. In this study, we aimed to evaluate the effects of the conditioned medium (CM), collected at different time points during in vitro cardiomyogenesis of human embryonic stem cells (hESCs), to direct cell behavior. We assayed different cell types to demonstrate noncytotoxic effects from the collected CM and that the CM obtained at initial time points of cardiomyogenic differentiation could promote the cell proliferation. Otherwise, the secretome derived from cardiac committed cells during cardiomyogenesis was unable to improve angiogenesis or migration in endothelial cells, and ineffective to stimulate the differentiation of cardioblasts or increase the differentiation efficiency of hESC. Therefore, we demonstrated that the effectiveness of the CM response varies depending on the cell type and the differentiation step of hESC‐derived cardiomyocytes.
Paroxysmal nocturnal hemoglobinuria‐phenotype cells predict a good response to eltrombopag in patients with refractory aplastic anemia
Authors: Ishiyama Ken , Sato Keijiro , Imi Tatsuya , Hosokawa Kohei , Kondo Yukio , Sugimori Naomi , Yamazaki Hirohito , Nakao Shinji
Published: June 2020

To identify factors affecting responsiveness to eltrombopag (EPAG), we retrospectively analyzed 38 aplastic anemia patients treated with EPAG who were refractory (n = 29) or showed an inadequate response (n = 9) to conventional therapies. The efficacy was evaluated at 16 weeks after starting EPAG and at any given time when the best response was achieved. Hematologic responses were observed in 15 patients (39%) at week 16 and in 25 (66%) at any given time. Ten of 19 (53%) achieved transfusion independence. A univariate analysis revealed the presence of PNH‐phenotype cells and the relatively higher platelet counts as associated with a good response to EPAG.
Operationalizing the HIV prevention cascade for PWID using the integrated bio‐behavioural survey data from Ukraine
Authors: Dumchev Kostyantyn , Sazonova Yana , Smyrnov Pavlo , Cheshun Olga , Pashchuk Oksana , Saliuk Tetiana , Varetska Olga
Published: June 2020

Introduction

People who inject drugs (PWID) remain at high risk of HIV in many countries. The HIV prevention cascades have been proposed to replicate the success of the treatment cascades and reinvigorate the prevention programmes through improved monitoring, planning and delivery. We adapted the cascade framework to the PWID context in Ukraine, assessed gaps and analysed factors associated with achieving “access” and “effective use” outcomes.

Methods

Self‐reported data on the use of prevention services and risk behaviours from the 2017 integrated bio‐behavioural survey among PWID in Ukraine were used to construct cascades for needle/syringe and condom programmes (NSP and CP). Socio‐demographic and behavioural variables were evaluated as potential correlates of cascade outcomes.

Results

The NSP cascade analysis included 7815 HIV‐negative PWID. Motivation to use clean syringes was not assessed and assumed at 100%. Access to clean syringes through NSP in the past 12 months was reported by 2789 participants (35.7%). Effective use of syringes (no sharing in the past 30 days) was reported by 7405 participants (94.8%). NSP access was higher among women, individuals older than 44, and mixed drug users; while effective use was reported more frequently by men and opioid users, with no difference by age. The CP cascade analysis included 6606 (85%) of the HIV‐negative PWID who had sex in the past three months. Of those, 2282 (34.5%) received condoms, and 1708 (25.9%) reported consistent use with all partners in the past three months. Older PWID and mixed‐drug users accessed condoms more frequently; whereas younger subgroups and opioid users used them more consistently.

Conclusions

Overall, the cascade framework was useful to describe the status of HIV prevention among PWID in Ukraine and to identify areas for improvement in the programming and evaluation of HIV prevention. Access to needle/syringe and condom programmes was substantially below the recommended levels. Effective use of clean syringes was reported by a vast majority of PWID, although likely affected by self‐report bias; whereas consistent condom use was infrequent. Socio‐demographic and behavioural variables showed significant associations in NSP and CP cascade analyses, with little consistency between the access and effective use outcomes.
Use of data from various sources to evaluate and improve the prevention of mother‐to‐child transmission of HIV programme in Zimbabwe: a data integration exercise
Authors: Sibanda Euphemia L , Webb Karen , Fahey Carolyn A , Kang Dufour Mi‐Suk , McCoy Sandra I , Watadzaushe Constancia , Dirawo Jeffrey , Deda Marsha , Chimwaza Anesu , Taramusi Isaac , Mushavi Angela , Mukungunugwa Solomon , Padian Nancy , Cowan Frances M
Published: June 2020

Introduction

Despite improvements in prevention of mother‐to‐child transmission (PMTCT) of HIV outcomes, there remain unacceptably high numbers of mother‐to‐child transmissions (MTCT) of HIV. Programmes and research collect multiple sources of PMTCT data, yet this data is rarely integrated in a systematic way. We conducted a data integration exercise to evaluate the Zimbabwe national PMTCT programme and derive lessons for strengthening implementation and documentation.

Methods

We used data from four sources: research, Ministry of Health and Child Care (MOHCC) programme, Implementer – Organization for Public Health Interventions and Development, and modelling. Research data came from serial population representative cross‐sectional surveys that evaluated the national PMTCT programme in 2012, 2014 and 2017/2018. MOHCC and Organization for Public Health Interventions and Development collected data with similar indicators for the period 2018 to 2019. Modelling data from 2017/18 UNAIDS Spectrum was used. We systematically integrated data from the different sources to explore PMTCT programme performance at each step of the cascade. We also conducted spatial analysis to identify hotspots of MTCT.

Results

We developed cascades for HIV‐positive and negative‐mothers, and HIV exposed and infected infants to 24 months post‐partum. Most data were available on HIV positive mothers. Few data were available 6‐8 weeks post‐delivery for HIV exposed/infected infants and none were available post‐delivery for HIV‐negative mothers. The different data sources largely concurred. Antenatal care (ANC) registration was high, although women often presented late. There was variable implementation of PMTCT services, MTCT hotspots were identified. Factors positively associated with MTCT included delayed ANC registration and mobility (use of more than one health facility) during pregnancy/breastfeeding. There was reduced MTCT among women whose partners accompanied them to ANC, and infants receiving antiretroviral prophylaxis. Notably, the largest contribution to MTCT was from postnatal women who had previously tested negative (12/25 in survey data, 17.6% estimated by Spectrum modelling). Data integration enabled formulation of interventions to improve programmes.

Conclusions

Data integration was feasible and identified gaps in programme implementation/documentation leading to corrective interventions. Incident infections among mothers are the largest contributors to MTCT: there is need to strengthen the prevention cascade among HIV‐negative women.
Impact along the HIV pre‐exposure prophylaxis “cascade of prevention” in western Kenya: a mathematical modelling study
Authors: Bershteyn Anna , Sharma Monisha , Akullian Adam N , Peebles Kathryn , Sarkar Supriya , Braithwaite R Scott , Mudimu Edinah
Published: June 2020

Introduction

Over one hundred implementation studies of HIV pre‐exposure prophylaxis (PrEP) are completed, underway or planned. We synthesized evidence from these studies to inform mathematical modelling of the prevention cascade for oral and long‐acting PrEP in the setting of western Kenya, one of the world’s most heavily HIV‐affected regions.

Methods

We incorporated steps of the PrEP prevention cascade – uptake, adherence, retention and re‐engagement after discontinuation – into EMOD‐HIV, an open‐source transmission model calibrated to the demography and HIV epidemic patterns of western Kenya. Early PrEP implementation research from East Africa was used to parameterize prevention cascades for oral PrEP as currently implemented, delivery innovations for oral PrEP, and future long‐acting PrEP. We compared infections averted by PrEP at the population level for different cascade assumptions and sub‐populations on PrEP. Analyses were conducted over the 2020 to 2040 time horizon, with additional sensitivity analyses for the time horizon of analysis and the time when long‐acting PrEP becomes available.

Results

The maximum impact of oral PrEP diminished by over 98% across all prevention cascades, with the exception of long‐acting PrEP under optimistic assumptions about uptake and re‐engagement after discontinuation. Long‐acting PrEP had the highest population‐level impact, even after accounting for possible delays in product availability, primarily because its effectiveness does not depend on drug adherence. Retention was the most significant cascade step reducing the potential impact of long‐acting PrEP. These results were robust to assumptions about the sub‐populations receiving PrEP, but were highly influenced by assumptions about re‐initiation of PrEP after discontinuation, about which evidence was sparse.

Conclusions

Implementation challenges along the prevention cascade compound to diminish the population‐level impact of oral PrEP. Long‐acting PrEP is expected to be less impacted by user uptake and adherence, but it is instead dependent on product availability in the short term and retention in the long term. To maximize the impact of long‐acting PrEP, ensuring timely product approval and rollout is critical. Research is needed on strategies to improve retention and patterns of PrEP re‐initiation.