bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐Temperature Intramolecular [4+2] Cycloaddition of Allenes with Arenes for the Synthesis of Diene Ligands
Authors: Hari Durga Prasad , Pisella Guillaume , Wodrich Matthew D. , Tsymbal Artem V. , Tirani Farzaneh Fadaei , Scopelliti Rosario , Waser Jerome
Published: November 2020

The intramolecular [4+2] cycloaddition between arenes and allenes first reported by Himbert gives rapid access to rigid polycyclic scaffolds. Herein, we report a one‐pot oxyalkynylation/cycloaddition reaction proceeding under mild conditions (23–90 °C) and providing complex polycyclic architectures with high efficiency, and atom and step economy. The bicyclo[2.2.2]octadiene products were obtained with a wide variety of useful functional groups and were successfully applied as chiral ligands for metal catalysis. Computational studies gave a first rationalization of the low activation energy for the cycloaddition based on counter‐intuitive favorable dispersive interactions in the transition state.
The pH‐Induced Selectivity Between Cysteine or Histidine Coordinated Heme in an Artificial α‐Helical Metalloprotein
Authors: Koebke Karl J. , Kühl Toni , Lojou Elisabeth , Demeler Borries , Schoepp‐Cothenet Barbara , Iranzo Olga , Pecoraro Vincent L. , Ivancich Anabella
Published: November 2020

De Novo metalloprotein design assesses the relationship between metal active site architecture and catalytic reactivity. Herein, we use an α‐helical scaffold to control the iron coordination geometry when a heme cofactor is allowed to bind to either histidine or cysteine ligands, within a single artificial protein. Consequently, we uncovered a reversible pH‐induced switch of the heme axial ligation within this simplified scaffold. Characterization of the specific heme coordination modes was done by using UV/Vis and Electron Paramagnetic Resonance spectroscopies. The penta‐ or hexa‐coordinate thiolate heme (9≤pH≤11) and the penta‐coordinate imidazole heme (6≤pH≤8.5) reproduces well the heme ligation in chloroperoxidases or cyt P450 monooxygenases and peroxidases, respectively. The stability of heme coordination upon ferric/ferrous redox cycling is a crucial property of the construct. At basic pHs, the thiolate mini‐heme protein can catalyze O2 reduction when adsorbed onto a pyrolytic graphite electrode.
General Access to Modified α‐Amino Acids by Bioinspired Stereoselective γ‐C−H Bond Lactonization
Authors: Vicens Laia , Bietti Massimo , Costas Miquel
Published: November 2020

α‐Amino acids represent a valuable class of natural products employed as building blocks in biological and chemical synthesis. Because of the limited number of natural amino acids available, and of their widespread application in proteomics, diagnosis, drug delivery and catalysis, there is an increasing demand for the development of procedures for the preparation of modified analogues. Herein, we show that the use of bioinspired manganese catalysts and H2O2under mild conditions, provides access to modified α‐amino acids via γ‐C−H bond lactonization. The system can efficiently target 1°, 2° and 3° γ‐C−H bonds of α‐substituted and achiral α,α‐disubstituted α‐amino acids with outstanding site‐selectivity, good to excellent diastereoselectivity and (where applicable) enantioselectivity. This methodology may be considered alternative to well‐established organometallic procedures.
Generation and Characterization of the C3O2−Anion with an Unexpected Unsymmetrical Structure
Authors: Wang Lina , Pan Sudip , Lu Bo , Dong Xuelin , Li Hongmin , Deng Guohai , Zeng Xiaoqing , Zhou Mingfei , Frenking Gernot
Published: November 2020

The carbon suboxide anion C3O2−is generated in solid neon matrix. It is characterized by infrared absorption spectroscopy as well as quantum chemical calculations to have a planarCsstructure where two CO groups with significantly different bond lengths and angles are attached in a zigzag fashion to the central carbon atom. Bonding analysis indicates that it is best described by the bonding interactions between a neutral CO in a triplet excited state and a doublet excited state of CCO−.
Term position‐based language model for information retrieval
Authors: Hammache Arezki , Boughanem Mohand
Published: November 2020

Term position feature is widely and successfully used in IR and Web search engines, to enhance the retrieval effectiveness. This feature is essentially used for two purposes: to capture query terms proximity or to boost the weight of terms appearing in some parts of a document. In this paper, we are interested in this second category. We propose two novel query‐independent techniques based on absolute term positions in a document, whose goal is to boost the weight of terms appearing in the beginning of a document. The first one considers only the earliest occurrence of a term in a document. The second one takes into account all term positions in a document. We formalize each of these two techniques as a document model based on term position, and then we incorporate it into a basic language model (LM). Two smoothing techniques, Dirichlet and Jelinek‐Mercer, are considered in the basic LM. Experiments conducted on three TREC test collections show that our model, especially the version based on all term positions, achieves significant improvements over the baseline LMs, and it also often performs better than two state‐of‐the‐art baseline models, the chronological term rank model and the Markov random field model.
Impaktsicherheit von Baukonstruktionen durch mineralisch gebundene Komposite: Materialebene
Authors: Curosu Iurie , Mechtcherine Viktor , Vo Duy M. P. , Sennewald Cornelia , Cherif Chokri , Wölfel Enrico , Scheffler Christina , Gong Ting , Heravi Ali A. , Tamsen Erik , Balzani Daniel , Shehni Alaleh , Häußler‐Combe Ulrich , Fuchs Alexander , Kaliske Michael , Scope Christoph , Günther Edeltraud
Published: November 2020

Im Rahmen des DFG‐Graduiertenkollegs GRK 2250/1 „Impaktsicherheit von Baukonstruktionen durch mineralisch gebundene Komposite“ werden neuartige Verstärkungsmaterialien mit unterschiedlichen Faserbewehrungen entwickelt, die die Widerstandsfähigkeit bestehender Konstruktionen gegen kurzzeitdynamische Belastungen deutlich erhöhen sollen. Des Weiteren werden adäquate Prüfkonzepte und Messverfahren für eine grundlegende Charakterisierung und Beschreibung des dehnratenabhängigen Materialverhaltens geschaffen. Die experimentell erzielten Ergebnisse stellen eine wichtige Grundlage für die Formulierung numerischer Modelle zur Simulation von impaktbeanspruchten Kompositen sowie von verstärkten Betonstrukturen mit Kopplung unterschiedlicher Raum‐ und Zeitskalen dar. Schließlich werden im Rahmen des Projekts Methoden für die Analyse und Bewertung der Nachhaltigkeit und Resilienz von Verstärkungsmaßnahmen mit neuen Verbundwerkstoffen erarbeitet.
Soft repression: Subtle transcriptional regulation with global impact
Authors: Mitra Anindita , Raicu Ana‐Maria , Hickey Stephanie L. , Pile Lori A. , Arnosti David N.
Published: November 2020

Pleiotropically acting eukaryotic corepressors such as retinoblastoma and SIN3 have been found to physically interact with many widely expressed “housekeeping” genes. Evidence suggests that their roles at these loci are not to provide binary on/off switches, as is observed at many highly cell‐type specific genes, but rather to serve as governors, directly modulating expression within certain bounds, while not shutting down gene expression. This sort of regulation is challenging to study, as the differential expression levels can be small. We hypothesize that depending on context, corepressors mediate “soft repression,” attenuating expression in a less dramatic but physiologically appropriate manner. Emerging data indicate that such regulation is a pervasive characteristic of most eukaryotic systems, and may reflect the mechanistic differences between repressor action at promoter and enhancer locations. Soft repression may represent an essential component of the cybernetic systems underlying metabolic adaptations, enabling modest but critical adjustments on a continual basis.
Critical periods shaping the social brain: A perspective from Drosophila
Authors: Dombrovski Mark , Condron Barry
Published: November 2020

Many sensory processing regions of the central brain undergo critical periods of experience‐dependent plasticity. During this time ethologically relevant information shapes circuit structure and function. The mechanisms that control critical period timing and duration are poorly understood, and this is of special importance for those later periods of development, which often give rise to complex cognitive functions such as social behavior. Here, we review recent findings in Drosophila, an organism that has some unique experimental advantages, and introduce novel views for manipulating plasticity in the post‐embryonic brain. Critical periods in larval and young adult flies resemble classic vertebrate models with distinct onset and termination, display clear connections with complex behaviors, and provide opportunities to control the time course of plasticity. These findings may extend our knowledge about mechanisms underlying extension and reopening of critical periods, a concept that has great relevance to many human neurodevelopmental disorders.
Three‐year clinical outcomes with the ABSORB bioresorbable vascular scaffold in real life: Insights from the France ABSORB registry
Authors: Lhermusier Thibault , Carrie Didier , Cayla Guillaume , Fajadet Jean , Sainsous Joel , Elhadad Simon , Tarragano Francois , Chevalier Bernard , Ranc Sylvain , Curinier Corentin , Le Breton Herve , Koning Rene ,   The FRANCE ABSORB Investigators
Published: November 2020

Objectives

The aim of this study was to determine the 3‐year outcomes of patients treated with Absorb bioresorbable vascular scaffold (BVS) implantation.

Background

Randomized trials and observational registries performed in patients undergoing percutaneous coronary intervention have demonstrated higher 1‐year and midterm rates of device thrombosis and adverse events with BVS compared to contemporary drug eluting stent. Data on long‐term follow‐up of patients treated with BVS are scarce.

Methods

All patients treated with BVS were included in a large nationwide prospective multicenter registry (FRANCE ABSORB). The primary endpoint was a composite of cardiovascular death, myocardial infarction, and target lesion revascularization at 3 years. Secondary endpoints were 3‐year scaffold thrombosis and target vessel revascularization (TVR).

Results

Between September 2014 and April 2016, 2070 patients were included (mean age 55 ± 11 years; 80% men). The indication was acute coronary syndrome (ACS) in 49% of patients. At 3 years, the primary endpoint occurred in 184 patients (8.9%) and 3‐year mortality in 43 patients (2.1%). Scaffold thrombosis and TVR rates through 3 years were, respectively, 3 and 7.6%. In a multivariable analysis, independent predictors of primary endpoint occurrence were diabetes, oral anticoagulation, active smoking, absence of initial angiographic success and the association of a total BVS length ≥30 mm with the use of 2.5 mm diameter BVS.

Conclusions

Although 3‐year mortality was low in this ACS population, device‐related events were significant beyond 1 year. Total BVS length and 2.5 mm BVS were associated with higher rates of MACE at long‐term follow‐up.
Comparison of quantitative flow ratio, Pd/Pa and diastolic hyperemia‐free ratio versus fractional flow reserve in non‐culprit lesion of patients with non ST‐segment elevation myocardial infarction
Authors: Tebaldi Matteo , Biscaglia Simone , Erriquez Andrea , Penzo Carlo , Tumscitz Carlo , Scoccia Alessandra , Quadri Giorgio , Sacchetta Giorgio , Folla Anna , Vadalà Giuseppe , Fileti Luca , Campo Gianluca
Published: November 2020

Objectives

To investigate the correlation between quantitative flow ratio (QFR), Pd/Pa, diastolic hyperemia‐free ratio (DFR) and fractional flow reserve (FFR, gold standard) in non‐culprit lesion (NCL) of patients with non ST‐segment elevation myocardial infarction (NSTEMI).

Background

The non‐hyperemic pressure ratio (NHPR) and the angiography‐based indexes have been developed to overcome the limitation of the use of the FFR.

Methods

Between January and December 2019, 184 NCL from 116 NSTEMI patients underwent physiologic assessment and were included in the study. NCLs were investigated with QFR, Pd/Pa, DFR, and FFR. Mean values of QFR, Pd/Pa, DFR and FFR were 0.85 ± 0.10, 0.92 ± 0.07, 0.93 ± 0.05 and 0.84 ± 0.07, respectively.

Results

DFR and FFR showed a good correlation (r = 0.76). Bland and Altman plot showed a mean difference of 0.080. DFR Diagnostic accuracy was 88%. The area under the ROC curve (AUC) for DFR was 0.946 (95%CI 0.90–0.97, p = .0001). Similar findings were reported for Pd/Pa (r = 0.73; mean difference 0.095, diagnostic accuracy 84%, AUC 0.909 [95%CI 0.85–0.94, p = .0001]) and QFR (r = 0.68; mean difference 0.01; diagnostic accuracy 88%, AUC 0.964 [95% CI 0.91–0.98, p = .0001]). FFR, QFR, Pd/Pa and DFR identified 31%, 32%, 30% and 32% potentially flow‐limiting lesions, respectively.

Conclusions

In NSTEMI patients, QFR, Pd/Pa and DFR showed equivalence as compared to gold standard FFR in the discrimination of non‐culprit lesions requiring revascularization.
Computer‐assisted valve in valve in a deteriorated Mosaic valve using a library of bioprostheses
Authors: Belhaj Soulami Reda , Castro Miguel , Haigron Pascal , Verhoye Jean‐Philippe
Published: November 2020

Valve‐in‐valve (ViV) procedures have emerged from an off‐label procedure to a safe and efficient alternative to redo aortic valve replacement in the treatment of symptomatic structural valve deterioration (SVD). During ViV procedures, optimal placement of the transcatheter heart valve (THV) inside the degenerated bioprosthesis is of paramount importance regarding complications such as device embolization, coronary obstruction, periprosthetic regurgitation, residual gradients, and mitral valve injury, but also for the attainment of optimal hemodynamics. In the case of the Mosaic (Medtronic, Minneapolis, MN) valve, the limited radiopaque landmarks represent a challenge to a reproducible, optimal implantation. Such implantation may require multiple contrast injections and transesophageal echocardiogram (TEE) guidance. We herein describe a computer‐assisted ViV procedure inside a deteriorated Mosaic valve, achieving reproducible optimal placement using a preacquired library of bioprostheses 3D models. Our approach suggests an evolving paradigm in ViV procedures, from safe and efficient toward optimal therapy for symptomatic SVD.
Lewis Acidic Boranes, Lewis Bases, and Equilibrium Constants: A Reliable Scaffold for a Quantitative Lewis Acidity/Basicity Scale
Authors: Mayer Robert J. , Hampel Nathalie , Ofial Armin R.
Published: November 2020

A quantitative Lewis acidity/basicity scale toward boron‐centered Lewis acids has been developed based on a set of 90 experimental equilibrium constants for the reactions of triarylboranes with various O‐, N‐, S‐, and P‐centered Lewis bases in dichloromethane at 20 °C. Analysis with the linear free energy relationship log KB=LAB+LBB allows equilibrium constants, KB, to be calculated for any type of borane/Lewis base combination through the sum of two descriptors, one for Lewis acidity (LAB) and one for Lewis basicity (LBB). The resulting Lewis acidity/basicity scale is independent of fixed reference acids/bases and valid for various types of trivalent boron‐centered Lewis acids. It is demonstrated that the newly developed Lewis acidity/basicity scale is easily extendable through linear relationships with quantum‐chemically calculated or common physical–organic descriptors and known thermodynamic data (ΔH
). Furthermore, this experimental platform can be utilized for the rational development of borane‐catalyzed reactions.
Dimesitylborylethynylated Arenes: Unique Electronic and Photophysical Properties Caused by Ethynediyl (C≡C) Spacers
Authors: Mishiba Kentaro , Tanaka Yuya , Akita Munetaka
Published: November 2020

Herein, we report the synthesis and electrochemical and photophysical properties of aromatic hydrocarbons having one or two dimesitylborylethynyl peripherals. The mono‐ (1) and diboryl compounds (2), readily prepared by nucleophilic substitution reaction, are fairly stable to air and moisture in the solid state. The inserted ethynediyl (C≡C) spacer cancels the steric hindrance between the bulky dimesitylboryl groups and aromatic rings, leading to effective π conjugation over the B−C≡C−Ar linkages, as revealed by cyclic voltammetry. Despite the small structural differences, the photophysical properties of the benzene, naphthalene, and anthracene derivatives are different. Virtually no emission was observed from the benzene derivatives, whereas the anthracene derivatives emitted with high quantum yields both in solution and in the solid state. Notably, the naphthalene derivatives showed aggregation‐induced emission behavior. Unlike the common sterically congested triarylborane derivatives reported so far, the anthracene derivatives showed π–π*‐type absorption and emission bands, which derive from efficient intramolecular orbital interactions between the boron centers and anthracene moieties, as supported by DFT calculations. As a result, the dimesitylborylethynyl substituents effectively lower the LUMO levels of the aromatic hydrocarbon parts, whereas the HOMO levels are almost unaffected, thereby leading to materials with controllable HOMO–LUMO gaps.
Gelation kinetics of functionalized silica crosslinked polymeric gels used in conformance control applications
Authors: Shamlooh Mohamed , Hamza Ahmed , Hussein Ibnelwaleed A. , Nasser Mustafa S. , Salehi Saeed
Published: November 2020

The potential crosslinking of three types of nitrogen‐containing functionalized silica (TAAcONa, guanidine, and triamine) with polyacrylamide (PAM) has been investigated. Only triamine silica was able to crosslink with PAM, producing barely flowing gel with storage modulus of around 700 Pa. Micro differential scanning calorimeter (μDSC) analysis illustrated exothermic peaks indicating crosslinking of PAM with triamine and polyethyleneimine (PEI), with crosslinking onset temperatures of 80°C and 84°C. TGA analysis showed the thermal stability of the functionalized silica up to temperatures of more than 200°C. In the domain of study (up to 130°C), TAAcONa silica exhibited the highest weight loss of 5%. Different kinetic models were used to identify the degree of crosslinking and PAM/PEI has shown diffusion‐controlled reaction unlike PAM/triamine‐functionalized silica. The crosslinking mechanism of the new crosslinker is proposed to be similar to that of the PAM/PEI system. Yet, functionalized silica‐based gels are more stable and possess higher strength.
On set‐based association tests: Insights from a regression using summary statistics
Authors: Zhao Yanyan , Sun Lei
Published: November 2020

Motivated by, but not limited to, association analyses of multiple genetic variants, we propose here a summary statistics‐based regression framework. The proposed method requires only variant‐specific summary statistics, and it unifies earlier methods based on individual‐level data as special cases. The resulting score test statistic, derived from a linear mixed‐effect regression model, inherently transforms the variant‐specific statistics using the precision matrix to improve power for detecting sparse alternatives. Furthermore, the proposed method can incorporate additional variant‐specific information with ease, facilitating omic‐data integration. We study the asymptotic properties of the proposed tests under the null and alternatives, and we investigate efficient P‐value calculation in finite samples. Finally, we provide supporting empirical evidence from extensive simulation studies and two applications.
Valve‐in‐valve transcatheter aortic valve replacement to treat multijet paravalvular regurgitation: A case series and review
Authors: Randall Morgan H. , Lewandowski Thomas J. , Choi Calvin , Beaver Thomas M.
Published: November 2020

Treatment advances for severe symptomatic aortic stenosis including transcatheter and open surgical valve replacement have improved patient survival, length of stay, and speed to recovery. However, paravalvular regurgitation (PVR) is occasionally seen and when moderate or greater in severity is associated with an at least 2‐fold increase in 1 year mortality. While several treatment approaches focused on single‐jet PVR have been described in the literature, few reports describe multijet PVR. Multijet PVR can successfully be treated with a variety of catheter‐based options including valve‐in‐valve (ViV) transcatheter aortic valve replacement (TAVR). We present two patients with at least moderate PVR following aortic valve replacement who were successfully treated with ViV TAVR along with a review of literature highlighting our rationale for utilizing each management approach. Multijet PVR can be treated successfully with ViV TAVR, but additional options such as self‐expanding occluder devices and bioprosthetic valve fracture have a role as adjunctive treatments to achieve optimal results. The etiology of multijet PVR can differ between patients, this heterogeneity underscores the paucity of data to guide treatment strategies. Therefore, successful treatment of multijet PVR requires familiarity with available therapeutic options to achieve optimal results and, by extension, decrease patient mortality.
Electrocoagulation/Electroflotation Process for Removal of Organics and Microplastics in Laundry Wastewater
Authors: Akarsu Ceyhun , Deniz Fatma
Published: November 2020

In the present research, laundry wastewater treatment is studied using the electrocoagulation/electroflotation process. For the optimization of treatment conditions such as electrode type (Al–Al, Al–Fe, Fe–Fe, and Fe–Al), initial pH (5–9), current (0.54–2.16 A), and application time (15–60 min), response surface methodology is used. Removal efficiencies of chemical oxygen demand (COD), color, anionic surfactant, microplastic, and phosphate are studied. It is determined that the most effective removal is obtained with 2.16 A current, pH 9, and 60 min reaction time using Fe–Al electrode. Here, 91%, 94%, 100%, and 98% removal efficiencies are achieved for COD, surfactant, color, and microplastic, respectively. The operating cost of the combined process is calculated as $1.32 m−3for the optimum removal parameters. The adsorption kinetics study shows that the removal follows second‐order kinetics. The laboratory‐scale test results indicate that the electrocoagulation/electroflotation process is feasible for the treatment of laundry wastewater.
Isolation, Library Preparation, and Bioinformatic Analysis of Historical and Ancient Plant DNA
Authors: Latorre Sergio M. , Lang Patricia L. M. , Burbano Hernán A. , Gutaker Rafal M.
Published: November 2020

The ability to sequence DNA retrieved from ancient and historical material plays a crucial role in reinforcing evolutionary and anthropological inference. While the focus of the field is largely on analyzing DNA from ancient hominids and other animals, we have also learned from plant ancient DNA (aDNA), in particular, about human farming practices, crop domestication, environment management, species invasion, and adaptation to various environmental conditions. In the following protocols, we outline best practices for plant aDNA isolation, preparation for sequencing, bioinformatic processing, and authentication. We describe the process all the way from processing of archaeological or historical plant material to characterizing and authenticating sequencing reads. In alternative protocols, we include modifications to this process that are tailored to strongly degraded DNA. Throughout, we stress the importance of precautionary measures to successfully analyze aDNA. Finally, we discuss the evolution of the archaeogenomics field and the development of new methods, which both shaped this protocol. © 2020 Wiley Periodicals LLC.

Basic Protocol 1: Isolation of aDNA

Alternate Protocol 1: Isolation of ultra‐short DNA (Dabney modification)

Support Protocol 1: Preparation of PTB‐based mix

Support Protocol 2: Preparation of binding buffer

Basic Protocol 2: Preparation of genomic libraries

Alternate Protocol 2: Preparation of genomic libraries with uracil removal

Basic Protocol 3: Bioinformatic processing and authentication of aDNA
Simple Field Storage of Fish Samples for Measurement of DNA Content by Flow Cytometry
Authors: Hubálek Martin , Flajšhans Martin
Published: November 2020

Flow cytometry is an effective and widely used tool for determination of ploidy in fish, but it is not always possible to access the fresh samples for analysis. We investigated the potential for extended storage of fish tissue with sterlet and tench as representative species of Chondrostei and Teleostei, using blood and fin of subadult/adult specimens and tail of larvae. Thirteen procedures for extending storage, selected for rapidity and simplicity in both field and laboratory conditions, were tested for each tissue sample. Flow cytometry was applied to fresh tissue immediately after sampling and to tissue subjected to experimental protocols, always along with species‐specific standard, after 1, 5, and 10 days storage at 0–4°C or freezing at −80°C. The fluorochrome 4′,6‐diamidine‐2′‐phenylindole dihydrochloride was used with excitation/emission maximum 358/461 nm. Based on the measurability of stored samples, evaluation of directly measured coefficients of variation of their DNA peaks and the changes in fluorescence intensity compared to fresh tissue, optimal procedures for extended storage of the selected tissue types of the model species are suggested. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC. on behalf of International Society for Advancement of Cytometry.
Don’t stand so close to me: Microbiota‐facilitated enemy release dynamics in introduced Onthophagus taurus dung beetles
Authors: Parker Erik S. , Moczek Armin P.
Published: November 2020

Microbial symbionts can influence their hosts in stunningly diverse ways. Emerging research suggests that an underappreciated facet of these relationships is the influence microbes can have on their host's responses to novel, or stressful, environmental conditions. We sought to address these and related questions in populations resulting from the recent introduction and subsequent rapid range expansion of Onthophagus taurus dung beetles. Specifically, we manipulated both microbial communities and rearing temperature to detect signatures of developmental and life history differentiation in response to the local thermal conditions in two populations derived from the southern most (Florida) and northern most (Michigan) extremes of the exotic Eastern U.S. range of O. taurus. We then sought to determine the contributions, if any, of host‐associated microbiota to this differentiation. We found that when reared under common garden conditions individuals from Florida and Michigan populations differed significantly in developmental performance measures and life history traits, consistent with population divergence. At the same time, and contrary to our predictions, we failed to find support for the hypothesis that animals perform better if reared at temperatures that match their location of origin and that performance differences may be mediated by host‐associated microbiota. Instead, we found that microbiome swapping across host populations improved developmental performance in both populations, consistent with enemy release dynamics. We discuss the implications of our results for our understanding of the rapid spread of exotic O. taurus through the Eastern United States and the significance of symbiosis in host responses to novel environmental conditions more broadly.
How rapidly do self‐compatible populations evolve selfing? Mating system estimation within recently evolved self‐compatible populations of Azorean Tolpis succulenta (Asteraceae)
Authors: Kerbs Benjamin , Crawford Daniel J. , White Griffin , Moura Mónica , Borges Silva Lurdes , Schaefer Hanno , Brown Keely , Mort Mark E. , Kelly John K.
Published: November 2020

Genome‐wide genotyping and Bayesian inference method (BORICE) were employed to estimate outcrossing rates and paternity in two small plant populations of Tolpis succulenta (Asteraceae) on Graciosa island in the Azores. These two known extant populations of T. succulenta on Graciosa have recently evolved self‐compatibility. Despite the expectation that selfing would occur at an appreciable rate (self‐incompatible populations of the same species show low but nonzero selfing), high outcrossing was found in progeny arrays from maternal plants in both populations. This is inconsistent with an immediate transition to high selfing following the breakdown of a genetic incompatibility system. This finding is surprising given the small population sizes and the recent colonization of an island from self‐incompatible colonists of T. succulenta from another island in the Azores, and a potential paucity of pollinators, all factors selecting for selfing through reproductive assurance. The self‐compatible lineage(s) likely have high inbreeding depression (ID) that effectively halts the evolution of increased selfing, but this remains to be determined. Like their progeny, all maternal plants in both populations are fully outbred, which is consistent with but not proof of high ID. High multiple paternity was found in both populations, which may be due in part to the abundant pollinators observed during the flowering season.
Rockhopper Penguin–Imperial Cormorant mixed colonies in the Falkland Islands: a stroke of luck for late breeders
Authors: Morandini Virginia , Dugger Katie M. , Ainley David , Ferrer Miguel
Published: November 2020

Mixed‐species colonies occur frequently, especially among seabirds, and may provide mutual benefits among associated species including antipredator advantages. The “protector” species in such associations may provide early warning signals or by aggressively defending their own nests, may expel predators from the area. We explored costs and benefits to Rockhopper Penguins (Eudyptes chrysocome) in relation to offspring production in both monospecific colonies and those mixed with Imperial Cormorants (Phalacrocorax atriceps) at Saunders Island (Falkland Islands), emphasizing differences in predation pressure. We considered behavioral responses of chicks (in crèches), as well as differences in their nutritional condition, morphometric measurements, and survival compared among different breeding colonies. Our study revealed a paradox: High‐quality adult penguins, those arriving early and occupying lower‐elevation sites closer to the coast, produced better‐nourished chicks earlier in the season. However, they averaged half the number of chicks fledged, compared to breeders that arrived later in the season. Late breeders were forced by unavailability of optimal habitat to nest in more elevated areas, forming mixed colonies with cormorants, which, in turn, provided them with protection from nest predators. This study provides an example of the role of luck in nature, and how it may compensate for differences in individual fitness.
Species- and Tissue-Specific Avian Chronic Toxicity Values for Perfluorooctane Sulfonate (PFOS) and a Binary Mixture of PFOS and Perfluorohexane Sulfonate
Authors: Dennis Nicole M. , Subbiah Seenivasan , Karnjanapiboonwong Adcharee , Dennis Michael L. , McCarthy Chris , Salice Christopher J. , Anderson Todd A.
Published: November 2020

To further characterize avian toxicity to environmental levels of select per- and poly-fluoroalkyl substances (PFAS), we established species- and tissue-specific PFAS chronic toxicity values (CTVs) associated with a lowest-observable–adverse effect level (LOAEL) threshold previously established for northern bobwhite quail (Colinus virginianus) chronically orally exposed via drinking water to either perfluorooctane sulfonate (PFOS) or a simple PFAS mixture. Aided by advances in analytical techniques, the novel avian oral PFAS CTVs reported in the present study are lower than the previously reported toxicity reference values (TRVs) estimated for birds chronically exposed via feed. Thus, current avian PFOS TRVs may not be fully protective of wild avian populations at PFAS-impacted sites. Also, likely due to differences in bioavailability, bioaccessibility, and toxicokinetics among individual PFAS between oral exposure types, we found higher bioaccumulation factors in all assessed tissues from birds exposed via water versus feed. Thus, we propose that future characterization of chemical toxicity due to ingestion exposure initially include a full examination of all probable sources of oral exposure for the most accurate derivation of TRVs and a more complete picture of ecological risk. The avian PFAS LOAEL CTVs established in the present study can be modified with the use of uncertainty factors to derive site-specific avian TRVs for ecological risk assessment at PFAS-impacted sites. From differences observed in the behavior of PFOS when administered as either a single chemical or part of a binary mixture with perfluorohexane sulfonate (PFHxS), we verified that PFOS was absorbed and distributed differently when coadministered with PFHxS and that PFOS likely interacted with PFHxS differently among tissues, helping to explain the differences observed in avian toxicity between exposures. Environ Toxicol Chem 2021;40:899–909. © 2020 SETAC
Plasticity via feedback reduces the cost of developmental instability
Authors: Matthey-Doret Remi , Draghi Jeremy A. , Whitlock Michael C.
Published: November 2020

Costs of plasticity are thought to have important physiological and evolutionary consequences. A commonly predicted cost to plasticity is that plastic genotypes are likely to suffer from developmental instability. Adaptive plasticity requires that the developing organism can in some way sense what environment it is in or how well it is performing in that environment. These two information pathways—an “environmental signal” or a “performance signal” that indicates how well a developing phenotype matches the optimum in the current environment—can differ in their consequences for the organism and its evolution. Here, we consider how developmental instability might emerge as a side-effect of these two distinct mechanisms. Because a performance cue allows a regulatory feedback loop connecting a trait to a feedback signal, we hypothesized that plastic genotypes using a performance signal would be more developmentally robust compared to those using a purely environmental signal. Using a numerical model of a network of gene interactions, we show that plasticity comes at a cost of developmental instability when the plastic response is mediated via an environmental signal, but not when it is mediated via a performance signal. We also show that a performance signal mechanism can evolve even in a constant environment, leading to genotypes preadapted for plasticity to novel environments even in populations without a history of environmental heterogeneity.
Organic production of vinegar from mango and papaya
Authors: Bouatenin Koffi Maïzan Jean‐Paul , Kouamé Kohi Alfred , Gueu‐Kehi Minkapieu Edwige , Djéni N’Dédé Théodore , Djè Koffi Marcellin
Published: November 2020

The study describes the transformation of mangoes of the local variety "Assabonou" and papaya solo No.8 into alcohol and then into vinegar through the process of directed fermentation. Indeed, mango and papaya juices extracted from ripe fruits contained in vials are first subjected to an alcoholic fermentation with Saccharomyces cerevisiae in anaerobic conditions and secondly to an acetic fermentation with strains of acetic acid bacteria cultivated from unpasteurized cider vinegar. To assess the quality of the vinegars produced, their profile and composition in organic acid and volatile compounds were compared to those of an unpasteurized cider vinegar from France and a vinegar produced in Côte d’Ivoire. The ethanol content for both juices is more or less high with 9.24 ± 0.04 g/L for mango and 12.68 ± 0.39 g/L for papaya. The concentration of acetic acid is the highest of the organic acids for the four vinegars ranging from 37.46 ± 4.6 g/L to 55.85 ± 9.94 g/L. The acetic acid contents of mango and papaya vinegars are close to that of unpasteurized cider vinegar from France but higher than that of vinegar produced in Côte d'Ivoire. Thus, this study allowed the production of "Assabonou" mango and papaya vinegars from two consecutive fermentations (alcoholic then acetic). This process is fast, less expensive and easily applicable. This application case could be an alternative for the processing of seasonal fruits to reduce postharvest losses.
Reliability, sensitivity, and predictive value of fMRI during multiple object tracking as a marker of cognitive training gain in combination with tDCS in stroke survivors
Authors: Kolskår Knut K. , Richard Geneviève , Alnæs Dag , Dørum Erlend S. , Sanders Anne‐Marthe , Ulrichsen Kristine M. , Sánchez Jennifer Monereo , Ihle‐Hansen Hege , Nordvik Jan E. , Westlye Lars T.
Published: November 2020

Computerized cognitive training (CCT) combined with transcranial direct current stimulation (tDCS) has showed some promise in alleviating cognitive impairments in patients with brain disorders, but the robustness and possible mechanisms are unclear. In this prospective double‐blind randomized clinical trial, we investigated the feasibility and effectiveness of combining CCT and tDCS, and tested the predictive value of and training‐related changes in fMRI‐based brain activation during attentive performance (multiple object tracking) obtained at inclusion, before initiating training, and after the three‐weeks intervention in chronic stroke patients (>6 months since hospital admission). Patients were randomized to one of two groups, receiving CCT and either (a) tDCS targeting left dorsolateral prefrontal cortex (1 mA), or (b) sham tDCS, with 40s active stimulation (1 mA) before fade out of the current. Of note, 77 patients were enrolled in the study, 54 completed the cognitive training, and 48 completed all training and MRI sessions. We found significant improvement in performance across all trained tasks, but no additional gain of tDCS. fMRI‐based brain activation showed high reliability, and higher cognitive performance was associated with increased tracking‐related activation in the dorsal attention network and default mode network as well as anterior cingulate after compared to before the intervention. We found no significant associations between cognitive gain and brain activation measured before training or in the difference in activation after intervention. Combined, these results show significant training effects on trained cognitive tasks in stroke survivors, with no clear evidence of additional gain of concurrent tDCS.
Who's declining the “free lunch”? New evidence from the uptake of public child dental benefits
Authors: Nguyen Ha Trong , Le Huong Thu , Connelly Luke B
Published: November 2020

This study provides the first evidence on the determinants of uptake of two recent public dental benefit programs for Australian children and adolescents from disadvantaged families. Using longitudinal data from a nationally representative survey linked to administrative data with accurate information on eligibility and uptake, we find that only a third of all eligible families actually claim their benefits. We provide new and robust evidence consistent with the idea advanced by recent economic literature that cognitive biases and behavioral factors are barriers to uptake. For instance, mothers with worse mental health or riskier lifestyles are much less likely to claim the available benefits for their children. These barriers to uptake are particularly large in magnitude: together, they reduce the uptake rate by up to 10 percentage points (or 36%). We also find some indicative evidence that a lack of information is a barrier to uptake.
Direct and indirect effects of rainfall and vegetation coverage on runoff, soil loss, and nutrient loss in a semi‐humid climate
Authors: Huo Jiayi , Liu Changjun , Yu Xinxiao , Chen Lihua , Zheng Wenge , Yang Yuanhui , Yin Changwen
Published: November 2020

Soil and nutrient loss play a vital role in eutrophication of water bodies. Several simulated rainfall experiments have been conducted to investigate the effects of a single controlling factor on soil and nutrient loss. However, the role of precipitation and vegetation coverage in quantifying soil and nutrient loss is still unclear. We monitored runoff, soil loss, and soil nutrient loss under natural rainfall conditions from 2004 to 2015 for 50–100 m2 runoff plots around Beijing. Results showed that soil erosion was significantly reduced when vegetation coverage reached 20% and 60%. At levels below 30%, nutrient loss did not differ among different vegetation cover levels. Minimum soil N and P losses were observed at cover levels above 60%. Irrespective of the management measure, soil nutrient losses were higher at high‐intensity rainfall (Imax30>15 mm/h) events compared to low‐intensity events (p < 0.05). We applied structural equation modelling (SEM) to systematically analyze the relative effects of rainfall characteristics and environmental factors on runoff, soil loss, and soil nutrient loss. At high‐intensity rainfall events, neither vegetation cover nor antecedent soil moisture content (ASMC) affected runoff and soil loss. After log‐transformation, soil nutrient loss was significantly linearly correlated with runoff and soil loss (p < 0.01). In addition, we identified the direct and indirect relationships among the influencing factors of soil nutrient loss on runoff plots and constructed a structural diagram of these relationships. The factors positively impacting soil nutrient loss were runoff (44%–48%), maximum rainfall intensity over a 30‐min period (18%–29%), rainfall depth (20%–27%), and soil loss (10%–14%). Studying the effects of rainfall and vegetation coverage factors on runoff, soil loss, and nutrient loss can improve our understanding of the underlying mechanism of slope non‐point source pollution.
532‐nm‐excited hyper‐Raman spectroscopy of amino acids
Authors: Wen Chun‐I , Yu Chi‐Nan , Thirumalaivasan Natesan , Hiramatsu Hirotsugu
Published: November 2020

This paper reports the hyper‐Raman (HR) spectra of the 20 amino acids in aqueous solution in the range of 400–1,800 cm−1 with an excitation wavelength of 532 nm. A remarkable common feature in the nonresonance HR spectra is the large intensity of the HR bands of the COO− group. Whereas the peak position is mostly identical between the HR and Raman spectra, the intensity pattern is not. We discuss the similarities and dissimilarities between the pattern of the two spectra of each amino acid and give possible assignments to each HR band by comparing them with those of the corresponding Raman band. This study offers a reference for the HR spectra of the amino acids as the basic building block of proteins. It helps interpret the HR spectra of proteins and peptides.
A quantitative assessment of the reactivity of the regioisomers of xylenol by investigation of rapid chlorination kinetics in aqueous solution employing hydrodynamic voltammetry complemented by molecular docking with acetylcholinesterase: A two‐pronged approach
Authors: Borkar Vitthal T.
Published: November 2020

Kinetic data is an elegant tool to quantitatively assess structure—reactivity correlation of organic substrates in reactions and is immaculate if endorsed with complementary information. Halogenations of aromatic substrates in aqueous medium are rapid reactions necessitating special techniques for their study. Their rates depend on nature of the reagents, nucleophilicity of the substrates, and steric compulsions involved. Herein, the rapid uncatalyzed chlorination kinetics of six regioisomers of xylenol by aqueous chlorine has been investigated using hydrodynamic voltammetry. These data have been supported with those obtained from molecular docking studies of the xylenol regioisomers with acetylcholinesterase in this two‐pronged approach. The magnitudes of the velocity constants, energies of activation, frequency factors, and entropy of activation in these six reactions assess, quantitatively and unambiguously, the reactivity of the regioisomers of xylenol when complemented with the binding energy data obtained from molecular docking.
Preparation and electrochemical characterization of Ti‐based amorphous metallic glass with high strength
Authors: Li Xuewu , Zhang Lin , Shi Tian , Yu Weining , Shao Jinhui , Zhou Xuegang , He Yuxing , Zhang Binbin
Published: November 2020

Ti‐based amorphous metallic glasses have excellent mechanical, physical, and chemical properties, which is an important development direction and research hotspot of metal composite reinforcement. As a stable, simple, efficient, and large‐scale preparation technology of metallic powders, the gas atomization process provides an effective way of preparing amorphous metallic glasses. In this study, the controllable fabrication of a Ti‐based amorphous powder, with high efficiency, has been realized by using gas atomization. The scanning electron microscope, energy‐dispersive spectrometer, and X‐ray diffraction are used to analyze surface morphology, element distribution, and phase structure, respectively. A microhardness tester is used to measure the mechanical property. An electrochemical workstation is used to characterize corrosion behavior. The results show that as‐prepared microparticles are more uniform and exhibit good amorphous characteristics. The mechanical test shows that the hardness of amorphous powder is significantly increased as compared with that before preparation, which has the prospect of being an important part of engineering reinforced materials. Further electrochemical measurement shows that the corrosion resistance of the as‐prepared sample is also significantly improved. This study has laid a solid foundation for expanding applications of Ti‐based metallic glasses, especially in heavy‐duty and corrosive domains.
CEO influence on P2P platform survival: Education and experience do matter!
Authors: Liu Ying , Wang Rui , Qin Jin
Published: November 2020

This study examines the effect of a CEO's education and experience on the survival probability of peer‐to‐peer (P2P) platforms in China. Our empirical results show that the education level of the CEO is positively related to platform survival probability. Interestingly, CEO possession of an MBA degree does not have a significant effect on the survival probability of platforms. We also found that the CEO's experience does have a positive impact. Moreover, by separating platforms into state‐owned and nonstate‐owned groups, we find a discrepancy that the effects of the CEO's education and experience are less significant for state‐owned platforms.
Biorthogonal wavelets on the spectrum
Authors: Ahmad Owais , Sheikh Neyaz A. , Nisar Kottakkaran Sooppy , Shah Firdous A.
Published: November 2020

In this article, we introduce the notion of biorthgonoal nonuniform multiresolution analysis on the spectrum
, where N ≥ 1 is an integer and r is an odd integer with 1 ≤ r ≤ 2N − 1 such that r and N are relatively prime. We first establish the necessary and sufficient conditions for the translates of a single function to form the Riesz bases for their closed linear span. We provide the complete characterization for the biorthogonality of the translates of scaling functions of two nonuniform multiresolution analysis and the associated biorthogonal wavelet families. Furthermore, under the mild assumptions on the scaling functions and the corresponding wavelets associated with nonuniform multiresolution analysis, we show that the wavelets can generate Reisz bases.