bluuebunny/crossref_metadata_2025 huggingface dataset:
Biguanides in combination with olaparib limits tumorigenesis of drug‐resistant ovarian cancer cells through inhibition of Snail
Authors: Wang Qiong , López‐Ozuna Vanessa M. , Baloch Tahira , Bithras Joanne , Amin Oreekha , Kessous Roy , Kogan Liron , Laskov Ido , Yasmeen Amber
Published: December 2019

Ovarian cancer is the most lethal gynecological malignancy. Currently, new chemotherapeutic strategies are required to improve patient outcome and survival. Biguanides, classic anti‐diabetic drugs, have gained importance for theiri antitumor potency demonstrated by various studies. Olaparib is a PARP inhibitor approved for maintenance therapy following platinum‐based chemotherapy. Furthermore, Snai1, a transcription factor that works as a master regulator of the epithelial/mesenchymal transition process (EMT) is involved in ovarian cancer resistance and progression. Here we aimed to demonstrate the possible cross talk between biguanides and Snail in response to olaparib combination therapy. In this study, we have shown that while in A2780CR cells biguanides reduced cell survival (single treatments ~20%; combined treatment ~44%) and cell migration (single treatments ~45%; biguanide‐olaparib ~80%) significantly, A2780PAR exhibited superior efficacy with single (~60%) and combined treatments (~80%). Moreover, our results indicate that knock‐down of Snail further enhances the attenuation of migration, inhibits EMT related‐proteins (~90%) and induces a synergistic effect in biguanide‐olaparib treatment. Altogether, this work suggests a novel treatment strategy against drug‐resistant or recurrent ovarian cancer.
Quinoline Based Monocarbonyl Curcumin Analogs as Potential Antifungal and Antioxidant Agents: Synthesis, Bioevaluation and Molecular Docking Study
Authors: Nagargoje Amol A. , Akolkar Satish V. , Siddiqui Madiha M. , Subhedar Dnyaneshwar D. , Sangshetti Jaiprakash N. , Khedkar Vijay M. , Shingate Bapurao B.
Published: December 2019

In search for new fungicidal and free radical scavenging agents, we synthesized a focused library of 2‐chloroquinoline based monocarbonyl analogs of curcumin (MACs). The synthesized MACs were evaluated for in vitro antifungal and antioxidant activity. The antifungal activity was evaluated against five different fungal strains such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger, and Cryptococcus neoformans, respectively. Most of the synthesized MACs displayed promising antifungal activity compared to the standard drug Miconazole. Furthermore, molecular docking study on a crucial fungal enzyme sterol 14α‐demethylase (CYP51) could provide insight into the plausible mechanism of antifungal activity. MACs were also screened for in vitro radical scavenging activity using butylated hydroxytoluene (BHT) as a standard. Almost all MACs exhibited better antioxidant activity compared to BHT.
Role of Post‐translational Modifications in Alzheimer's Disease
Authors: Ramesh Madhu , Gopinath Pushparathinam , Govindaraju Thimmaiah
Published: December 2019

The global burden of Alzheimer's disease (AD) is growing. Valiant efforts to develop clinical candidates for treatment have continuously met with failure. Currently available palliative treatments are temporary and there is a constant need to search for reliable disease pathways, biomarkers and drug targets for developing diagnostic and therapeutic tools to address the unmet medical needs of AD. Challenges in drug‐discovery efforts raise further questions about the strategies of current conventional diagnosis; drug design; and understanding of disease pathways, biomarkers and targets. In this context, post‐translational modifications (PTMs) regulate protein trafficking, function and degradation, and their in‐depth study plays a significant role in the identification of novel biomarkers and drug targets. Aberrant PTMs of disease‐relevant proteins could trigger pathological pathways, leading to disease progression. Advancements in proteomics enable the generation of patterns or signatures of such modifications, and thus, provide a versatile platform to develop biomarkers based on PTMs. In addition, understanding and targeting the aberrant PTMs of various proteins provide viable avenues for addressing AD drug‐discovery challenges. This review highlights numerous PTMs of proteins relevant to AD and provides an overview of their adverse effects on the protein structure, function and aggregation propensity that contribute to the disease pathology. A critical discussion offers suggestions of methods to develop PTM signatures and interfere with aberrant PTMs to develop viable diagnostic and therapeutic interventions in AD.
Azido‐Desferrioxamine Siderophores as Functional Click‐Chemistry Probes Generated in Culture upon Adding a Diazo‐Transfer Reagent
Authors: Gotsbacher Michael P. , Codd Rachel
Published: December 2019

This work aimed to undertake the in situ conversion of the terminal amine groups of bacterial desferrioxamine (DFO) siderophores, including desferrioxamine B (DFOB), to azide groups to enable downstream click chemistry. Initial studies trialed a precursor‐directed biosynthesis (PDB) approach. Supplementing Streptomyces pilosus culture with blunt‐end azido/amine non‐native substrates designed to replace 1,5‐diaminopentane as the native diamine substrate in the terminal amine position of DFOB did not produce azido‐DFOB. Addition of the diazo‐transfer reagent imidazole‐1‐sulfonyl azide hydrogen sulfate to spent S. pilosus medium that had been cultured in the presence of 1,4‐diaminobutane, as a viable native substrate to expand the suite of native DFO‐type siderophores, successfully generated the cognate suite of azido‐DFO analogues. CuI‐mediated or strain‐promoted CuI‐free click chemistry reactions between this minimally processed mixture and the appropriate alkyne‐bearing biotin reagents produced the cognate suite of 1,4‐disubstituted triazole‐linked DFO‐biotin compounds as potential molecular probes, detected as FeIII‐loaded species. The amine‐to‐azide transformation of amine‐bearing natural products in complex mixtures by the direct addition of a diazo‐transfer reagent to deliver functional click chemistry reagents adds to the toolbox for chemical proteomics, chemical biology, and drug discovery.
Characterization of Metal‐zeolite Composite Catalysts: Determining the Environment of the Active Phase
Authors: Juneau Mitchell , Liu Renjie , Peng Yikang , Malge Akhilesh , Ma Zhiqiang , Porosoff Marc D.
Published: December 2019

Metal‐zeolite composite catalysts are attracting increased attention due to their unique multifunctional properties. However, it is challenging to identify the physicochemical environment of the active phase, which is essential to improve our understanding of the structure‐performance relationships of such complex catalysts. In this work, commonly available analytical techniques (FTIR, TEM, XRD, etc.) and state‐of‐the‐art user instrumentation (XAS, SANS, e‐TEM, etc.) are reviewed with respect to their applications at different stages of the catalyst lifetime, from early nucleation, to the reaction mechanism and deactivation. Each technique is discussed in detail with examples to provide suggestions and guidelines for choosing the characterization technique(s) that are most appropriate for determining the desired structure‐property relationships of metal‐zeolite composite catalysts. Understanding the most appropriate applications of characterization techniques promotes development of novel synthesis methodologies, and in turn, applications for designing active, selective and stable multifunctional metal‐zeolite composite catalysts.
Manganese Catalyzed Acceptorless Dehydrogenative Coupling Reactions
Authors: Waiba Satyadeep , Maji Biplab
Published: December 2019

Acceptorless dehydrogenative coupling (ADC) has emerged as a powerful tool in the chemists’ arsenal for the construction of various carbon‐carbon and carbon‐heteroatom bonds. These protocols are highly atom economical and environmentally benign as they do not require pre‐functionalized starting material and produce only dihydrogen (and water) as the by‐product. This technique, coupled with Earths’ abundant and less toxic manganese catalysis, can prove to be a vital strategy for the generation of molecular complexity from simple starting materials. Manganese catalyzed DHC has been of growing interest, and various low‐ and high‐valent manganese catalysts have been developed. These catalysts were demonstrated to show excellent catalytic activity for the formation of carbon‐carbon, carbon‐heteroatom bonds, and cascade reactions. In this mini‐review, we would like to highlight the recent progress that has been made in manganese catalyzed ADC reactions.
Solid‐State Hybrid Supercapacitor Assembled from a Heterostructured Co−Ni Battery‐like Cathode and Supercapacitor‐Type Highly Disordered Carbon Nanosheets
Authors: Li Zhan , Ma Kongjun , Mi Hongyu , Ji Chenchen , Li Zhiwei , Guo Fengjiao , He Shixue , Wang Conghui , Xu Mengjiao , Pang Huan
Published: December 2019

Hybrid at either the mechanism or the device level can lead to a hybridization effect of the kinetics and electrochemical characteristic of a supercapacitor (SC). Herein, a heterostructured NiCo2S4/CoxNi1‐x(OH)2 battery‐like cathode material was designed, with which the obtained sample accomplished the combination of excellent electronic and ionic conductivity so as to realize an enhanced faradaic redox storage process. Besides, a SC‐type highly capacitive anode material of a N and S co‐doped porous carbon nanosheets (ACNS) was also fabricated, which exhibits great advantages in terms of its enlarged specific surface area, the ease of introducing pseudocapacitive reactions, and its physical structure. These features directly lead to significant improvements in the electric double‐layer capacitor (EDLC)‐type electrochemical properties of the carbon anode. The combination of an EDLC‐type carbon anode with the redox‐reaction‐type cathode in a full cell device could potentially lead to a charge storage process that simultaneously integrates the electrophysical and electrochemical processes. For these reasons, the obtained solid‐state hybrid SC delivers a wide voltage window of 1.6 V, a high specific capacity of 121.3 C g−1, and enhanced energy/power densities of 26.1 Wh kg−1/11 kW kg−1. The as‐assembled device can maintain a high and stable capacity retention of 89.1 % for over 10 000 cycles. The developed hybrid assembly strategy and the electrode combination may provide design guidelines for designing other high‐energy hybrid SCs.
New Aspects of Platinum Group Metal‐Based Solid‐Solution Alloy Nanoparticles: Binary to High‐Entropy Alloys
Authors: Kusada Kohei , Wu Dongshuang , Kitagawa Hiroshi
Published: December 2019

Platinum group metal (PGM) nanoparticles (NPs) have been investigated in a variety of research fields such as catalysis and electronics. Alloying has been recognized as one of the most efficient ways of improving or creating properties in metals. Among the types of alloys, solid‐solution alloy NPs have the advantage of being capable of continuously changing their properties by tuning their composition. However, synthesizing PGM solid‐solution alloy NPs with any combination and composition is not an easy task owing to the metallurgical aspects. In this minireview, the focus is on recent advances in PGM‐based solid‐solution alloy NPs, and in particular those with immiscible alloy systems. Concepts, synthesis, and properties of the alloy NPs are introduced, and the existing challenges and future perspectives are discussed.
Synthesis and Tunable Optical Properties of C,N‐Chelated Borate Luminophores Derived from Potassium Acyltrifluoroborates
Authors: Taguchi Jumpei , Matsuura Satsuki , Seki Tomohiro , Ito Hajime
Published: December 2019

A new class of borate luminophores has been synthesized by a simple two‐step reaction using potassium acyltrifluoroborates (KATs) as starting materials. The hydrazones obtained from reactions between KATs and 2‐hydrazinopyridines followed by a cyclization resulted in the unprecedented formation of C,N‐chelated six‐membered bora‐heterocycles. Under consideration of the results of DFT and TD‐DFT calculations, four luminophores based on such bora‐heterocycles are designed and synthesized, which exhibit a tunable fluorescence range from blue to red in the solid state. Moreover, one of the luminophores exhibits mechanofluorochromism from blue to yellow/green. As a result of the aforementioned mechanochromism of one of these luminophores, white‐color emission was achieved by simply mixing the four luminophores.
Improved Performance of Carbon Electrode Perovskite Solar Cells Using Urea Treatment in Two‐Step Processing
Authors: Xu Tingting , Sun Xuelin , Cao Weiwei , Qin Xiulan , Gurung Ashim , Lv Shaoshen , Chen Yonghua , Chen Lixin , Huang Wei , Qiao Qiquan
Published: December 2019

Perovskite solar cell has made a steady research progress with superior photovoltaic power conversion efficiency (PCE) over 25%. The quality of perovskite film is a key factor affecting device efficiency. Lewis bases such as urea, DMSO and thiourea etc. have been applied in perovskite precursor solutions for one step processing to effectively control the film morphology. Herein, we report urea treatment in a two‐step processing for obtaining high quality methylammonium lead triiodide perovskite (CH3NH3PbI3) film, which is accomplished by immersing the PbI2 film into the mixture solution of urea/methylammonium iodide (MAI). The optimized urea concentration in the MAI solution is 0.4 mg/mL, leading to larger‐sized and better crystalline perovskite grains than that without urea additive. The main function of the urea additive is the formation of the adduct MAI⋅PbI2⋅O=C(NH2)2, retarding the crystallization process of the perovskite film. The steady‐state and time‐resolved photoluminescence measurements revealed that perovskite CH3NH3PbI3 grown using optimized concentration of urea has prolonged carrier lifetime and reduced carrier recombination. Finally, the carbon‐based perovskite solar cells fabricated from the optimal urea concentration of 0.4 mg/mL achieved the enhanced photovoltaic performance with the highest PCE of 13.10% and an average value of 11.34%, in comparison to devices without urea treatment exhibiting an average PCE of only 8.67%.
Sensitivity reduction of degree histogram publication under node differential privacy via mean filtering
Authors: Lan Sun , Xin Huang , Yingjie Wu , Yongyi Guo
Published: December 2019

Publication of nodes' degree information in the form of histogram provides useful information about the graph as well as the risk of privacy disclosure. Under the robust protection of node‐differential privacy (node‐DP), publishing result's accuracy mainly depends on the global sensitivity of this publishing task. Thus, the reduction of sensitivity is of great importance. Existing methods for degree histogram publication under node‐DP are mostly based on limitation of maximum degree, whose sensitivity is still high, leading an unbearable noise scale. In this paper, we innovatively propose a method to tackle this issue. Firstly, we introduce mean filtering to process the histogram, almost halve the original sensitivity. Then, we use a series of techniques to further improve publishing accuracy, instituting a complete workflow for degree histogram publication under node‐DP. Experimental results show that our method effectively improves the accuracy.
Medical image fusion method by using Laplacian pyramid and convolutional sparse representation
Authors: Liu Feiqiang , Chen Lihui , Lu Lu , Ahmad Awais , Jeon Gwanggil , Yang Xiaomin
Published: December 2019

Medical image fusion is a technology of combining multi‐modal images to generate a composite image, which is favorable to improve the capability of doctors in diagnosis and treatment of the disease. In order to achieve good performance, a fusion method by combining Laplacian pyramid (LP) and convolutional sparse representation (CSR) is proposed. In the proposed fusion method, LP transform is performed on each pair of pre‐registered computed tomography image and magnetic resonance image to obtain their detail layers and base layer. Then, the base layer is fused with a CSR‐based approach, whereas the detail layers are merged using the popular “max‐absolute” rule. Finally, the fused image is reconstructed by performing the inverse LP transform over the fused base layer and detail layers. The advantages of our method are that the texture detail information contained in source images can be fully extracted and the overall contrast of the final fused image will not be decreased. Experimental results demonstrate the superiority of the proposed method.
Evaluation of performance portability frameworks for the implementation of a particle‐in‐cell code
Authors: Artigues Victor , Kormann Katharina , Rampp Markus , Reuter Klaus
Published: December 2019

This paper reports on an in‐depth evaluation of the performance portability frameworks Kokkos and RAJA with respect to their suitability for the implementation of complex particle‐in‐cell (PIC) simulation codes, extending previous studies based on codes from other domains. At the example of a particle‐in‐cell model, we implemented the hotspot of the code in C++ and parallelized it using OpenMP, OpenACC, CUDA, Kokkos, and RAJA, targeting multi‐core (CPU) and graphics (GPU) processors. Both Kokkos and RAJA appear mature, are usable for complex codes, and keep their promise to provide performance portability across different architectures. Comparing the obtainable performance on state‐of‐the art hardware, but also considering aspects such as code complexity, feature availability, and overall productivity, we finally draw the conclusion that the Kokkos framework would be suited best to tackle the massively parallel implementation of the full PIC model.
Beyond the Randomized Clinical Trial: Innovative Data Science to Close the Pediatric Evidence Gap
Authors: Goulooze Sebastiaan C. , Zwep Laura B. , Vogt Julia E. , Krekels Elke H.J. , Hankemeier Thomas , van den Anker John N. , Knibbe Catherijne A.J.
Published: December 2019

Despite the application of advanced statistical and pharmacometric approaches to pediatric trial data, a large pediatric evidence gap still remains. Here, we discuss how to collect more data from children by using real‐world data from electronic health records, mobile applications, wearables, and social media. The large datasets collected with these approaches enable and may demand the use of artificial intelligence and machine learning to allow the data to be analyzed for decision making. Applications of this approach are presented, which include the prediction of future clinical complications, medical image analysis, identification of new pediatric end points and biomarkers, the prediction of treatment nonresponders, and the prediction of placebo‐responders for trial enrichment. Finally, we discuss how to bring machine learning from science to pediatric clinical practice. We conclude that advantage should be taken of the current opportunities offered by innovations in data science and machine learning to close the pediatric evidence gap.
Translational Knowledge Discovery Between Drug Interactions and Pharmacogenetics
Authors: Wu Heng‐Yi , Shendre Aditi , Zhang Shijun , Zhang Pengyue , Wang Lei , Zeruesenay Desta , Rocha Luis M. , Shatkay Hagit , Quinney Sara K. , Ning Xia , Li Lang
Published: December 2019

Clinical translation of drug‐drug interaction (DDI) studies is limited, and knowledge gaps across different types of DDI evidence make it difficult to consolidate and link them to clinical consequences. Consequently, we developed information retrieval (IR) models to retrieve DDI and drug‐gene interaction (DGI) evidence from 25 million PubMed abstracts and distinguish DDI evidence into in vitro pharmacokinetic (PK), clinical PK, and clinical pharmacodynamic (PD) studies for US Food and Drug Administration (FDA) approved and withdrawn drugs. Additionally, information extraction models were developed to extract DDI‐pairs and DGI‐pairs from the IR‐retrieved abstracts. An overlapping analysis identified 986 unique DDI‐pairs between all 3 types of evidence. Another 2,157 and 13,012 DDI‐pairs and 3,173 DGI‐pairs were identified from known clinical PK/PD DDI, clinical PD DDI, and DGI evidence, respectively. By integrating DDI and DGI evidence, we discovered 119 and 18 new pharmacogenetic hypotheses associated with CYP3A and CYP2D6, respectively. Some of these DGI evidence can also aid us in understanding DDI mechanisms.
The effects of corporate social responsibility on corporate reputation and firm financial performance: Moderating role of responsible leadership
Authors: Javed Muzhar , Rashid Muhammad Amir , Hussain Ghulam , Ali Hafiz Yasir
Published: December 2019

Drawing on stakeholder theory and contingency theory, this study examines the effects of Corporate Social Responsibility (CSR) on corporate reputation and financial performance of Pakistani firms with a moderating role of responsible leadership. Perceptual data on CSR, reputation, and performance were collected from 224 senior‐level Pakistani managers through a questionnaire survey. Structural equation modeling was used to analyze the data. The results reveal that socially responsible initiatives for disparate stakeholders significantly and positively influence corporate reputation and financial performance. Moreover, CSR–reputation and CSR–performance direct relationships were found to be negatively moderated by responsible leadership. It suggests that when socially responsible firms have leaders with strong stakeholder values, they practice excessive CSR that hurts performance.
Durable Cathodes and Electrolyzers for the Efficient Aqueous Electrochemical Reduction of CO2
Authors: Nwabara Uzoma O. , Cofell Emiliana R. , Verma Sumit , Negro Emanuela , Kenis Paul J. A.
Published: December 2019

The world emits over 14 gigatons of CO2 in excess of what can be remediated by natural processes annually, contributing to rising atmospheric CO2 levels and increasing global temperatures. The electrochemical reduction of CO2 (CO2RR) to value‐added chemicals and fuels has been proposed as a method for reusing these excess anthropogenic emissions. While state‐of‐the‐art CO2RR systems exhibit high current densities and faradaic efficiencies, research on long‐term electrode durability, necessary for this technology to be implemented commercially, is lacking. Previous reviews have focused mainly on the CO2 electrolyzer performance without considering durability. In this Review, the need for research into high‐performing and durable CO2RR systems is stressed by summarizing the state‐of‐the‐art with respect to durability. Various failure modes observed are also reported and a protocol for standard durability testing of CO2RR systems is proposed.
Gel–Emulsion‐Templated Polymeric Aerogels for Water Treatment by Organic Liquid Removal and Solar Vapor Generation
Authors: Liu Jianfei , Yang Hui , Liu Kaiqiang , Miao Rong , Fang Yu
Published: December 2019

The importance of water cannot be overstated. It is the most important natural resource for our survival and development. The development of suitable materials for efficient water purification will provide a critical contribution for sustainable water use. In this context, a gel–emulsion‐templated synthesis of a polymeric aerogel has been developed for water treatment. Owing to its hydrophobic nature, the aerogel shows high sorption (nearly 20 times its weight) for organic liquids, such as toluene, phenol, and nitrobenzene, and can be used to remove them from water. The aerogel shows low thermal conductivity (0.032 W m−1 K−1) and excellent light absorption efficiency (>92 %) after carbonization, which provides the possibility for the construction of an interfacial solar vapor generation system. The as‐prepared materials are used to develop a two‐step approach to remove both organic and inorganic contaminants (salts) from water. Importantly, the aerogel shows excellent reusability and high efficiency both for oil sorption and for solar vapor generation. Moreover, the low cost and easy scale‐up of the preparation process lay a solid foundation for practical application. It is anticipated that the prepared aerogels would contribute not only to water purification but also to other related areas.
Carryover effects of temperature and pCO2 across multiple Olympia oyster populations
Authors: Spencer Laura H. , Venkataraman Yaamini R. , Crim Ryan , Ryan Stuart , Horwith Micah J. , Roberts Steven B.
Published: December 2019

Predicting how populations will respond to ocean change across generations is critical to effective conservation of marine species. One emerging factor is the influence of parental exposures on offspring phenotype, known as intergenerational carryover effects. Parental exposure may deliver beneficial or detrimental characteristics to offspring that can influence larval recruitment patterns, thus shaping how populations and community structure respond to ocean change. Impacts of adult exposure to elevated winter temperature and pCO2 on reproduction and offspring viability were examined in the Olympia oyster (Ostrea lurida) using three populations of adult, hatchery‐reared O. lurida, plus an additional cohort spawned from one of the populations. Oysters were sequentially exposed to elevated temperature (+4°C, at 10°C), followed by elevated pCO2 (+2,204 μatm, at 3,045 μatm) during winter months. Male gametes were more developed after elevated temperature exposure and less developed after high pCO2 exposure, but there was no impact on female gametes or sex ratios. Oysters previously exposed to elevated winter temperature released larvae earlier, regardless of pCO2 exposure. Those exposed to elevated winter temperature as a sole treatment released more larvae on a daily basis but, when also exposed to high pCO2, there was no effect. These combined results indicate that elevated winter temperature accelerates O. lurida spermatogenesis, resulting in earlier larval release and increased production, with elevated pCO2 exposure negating effects of elevated temperature. Altered recruitment patterns may therefore follow warmer winters due to precocious spawning, but these effects may be masked by coincidental high pCO2. Offspring were reared in common conditions for 1 yr, then deployed for 3 months in four estuarine bays with distinct environmental conditions. Offspring of parents exposed to elevated pCO2 had higher survival rates in two of the four bays. This carryover effect demonstrates that parental conditions can have substantial ecologically relevant impacts that should be considered when predicting impacts of environmental change. Furthermore, Olympia oysters may be more resilient in certain environments when progenitors are pre‐conditioned in stressful conditions. Combined with other recent studies, our work suggests that the Olympia may be more equipped than other oysters for the challenge of a changing ocean.
Female loggerhead sea turtles (Caretta caretta L.) rarely remate during nesting season
Authors: Lasala Jacob A. , Hughes Colin , Wyneken Jeanette
Published: December 2019

The goal of this study was to assess the consequences of single versus multiple paternity by identifying paternity of clutches per female to identify whether there were detectable costs or benefits. Multiple mating can occur when the benefits of mating outweigh the costs, but if costs and benefits are equal, no pattern is expected. Previous research on loggerhead sea turtle (Caretta caretta) populations found male‐biased breeding sex ratios and multiple mating by many females nesting in southwestern Florida. A sample of nesting loggerhead females who laid more than one nest over the course of the season and a subset of their hatchlings were examined from 36 clutches in 2016 on Sanibel Island, Florida. Males that fathered hatchlings in the first clutch sampled were identified in subsequent clutches. Interestingly, 75% of the females analyzed had mated singly. No male was represented in more than one female's clutches. The results suggest that females likely mate at the beginning of the season and use stored sperm for multiple clutches. Evidence for mating between laying events was limited. There was no consistent pattern across the subsequent multiple paternity clutches, suggesting benefits to loggerhead females likely equal their costs and subsequent mating is likely determined by female preference.
Association between blooming time and climatic adaptation in Prunus mume
Authors: Shi Ting , Luo Wenjie , Li Hantao , Huang Xiao , Ni Zhaojun , Gao Haidong , Iqbal Shahid , Gao Zhihong
Published: December 2019

Prunus mume Sieb. et Zucc. is an important fruit crop of the subtropical region, originating in China. It blooms earlier than other deciduous fruit trees, but different regions have different blooming periods. The time of anthesis is related to the dormancy period, and a certain amount of chilling promotes bud break and blooming. To identify the relationship between blooming time and the climatic adaptation of P. mume cultivars in China, the nuclear and chloroplast genomes of 19 cultivars from the main cultivation areas of P. mume in China were resequenced. The average depth of coverage was 34X–76X, and a total of 388,134 single nucleotide polymorphisms were located within the coding regions of the gene (CDs). Additionally, the 19 cultivar accessions were divided into three groups based on their blooming time: early, mid, and late. Associated with the blooming time groups, 21 selective sweep regions were identified, which could provide evidence supporting the possible model of P. mume domestication originating due to natural selection. Furthermore, we identified a flowering gene, FRIGIDA‐LIKE 3 (FRL3), seems to affect the blooming time and the climatic adaptation of P. mume cultivars. This study is a major step toward understanding the climatic adaptation of P. mume cultivars in China.
Alternative stable states in inherently unstable systems
Authors: Mushet David M. , McKenna Owen P. , McLean Kyle I.
Published: December 2019

Alternative stable states are nontransitory states within which communities can exist. However, even highly dynamic communities can be viewed within the framework of stable‐state theory if an appropriate “ecologically relevant” time scale is identified. The ecologically relevant time scale for dynamic systems needs to conform to the amount of time needed for a system's community to complete an entire cycle through its normal range of variation. For some systems, the ecologically relevant period can be relatively short (eg, tidal systems), for others it can be decadal (eg, prairie wetlands). We explore the concept of alternative stable states in unstable systems using the highly dynamic wetland ecosystems of North America's Prairie Pothole Region. The communities in these wetland ecosystems transition through multiple states in response to decadal‐long climate oscillations that cyclically influence ponded‐water depth, permanence, and chemistry. The perspective gained by considering dynamic systems in the context of stable‐state theory allows for an increased understanding of how these systems respond to changing drivers that can push them past tipping points into alternative states. Incorporation of concepts inherent to stable‐state theory has been suggested as a key scientific element upon which to base sustainable environmental management.
Analysis of evolutionary relationships provides new clues to the origins of weedy rice
Authors: Han Bing , Ma Xiaoding , Cui Di , Wang Yanjie , Geng Leiyue , Cao Guilan , Zhang Hui , Koh Hee‐Jong , Han Longzhi
Published: December 2019

Weedy rice (WR) (Oryza sativa f. spontanea) is considered to be a pest in modern rice production systems because it competes for resources, has poor yield characteristics, and subsequently has a negative effect on rice grain yield. The evolutionary relationships among WR, landrace rice (LR), improved rice (IR) cultivars, and wild rice are largely unknown. In this study, we conducted a population genetic analysis based on neutral markers and gene haplotypes in 524 rice accessions and a comparative transcriptomic analysis using 15 representative samples. The results showed that WR populations have the highest level of genetic diversity (He = 0.8386) and can be divided into two groups (japonica‐type and indica‐type). The japonica‐type WR accessions from Heilongjiang province (HLJ), Jilin province (JL), Liaoning province (LN), and NX provinces clustered with the landraces grown in these same provinces. The indica‐types from Jiangsu province (JS) also clustered with the indica‐type landraces from JS province. Comparative transcriptome analysis of WR‚ IR and LR from HLJ, JL, and LN provinces showed that the WR still clustered with the LR, and that the IR lines comprise a single population. Thirty‐two differentially expressed genes were shared by the IR and LR groups as well as between the IR and WR groups. Using Gene ontology (GO) analysis, we identified 19 shared GO terms in the IR and LR groups as well as between the IR and WR groups. Our results suggest that WR populations in China have diverse origins, and comparative transcriptome analysis of different types of rice from HLJ, JL, and LN provinces suggests that IR populations have become a end point in the evolution of WR, which provides a new perspective for the study of WR origins and lays a solid foundation for rice breeding.
Flower traits, habitat, and phylogeny as predictors of pollinator service: a plant community perspective
Authors: Herrera Carlos M.
Published: December 2019

Pollinator service is essential for successful sexual reproduction and long‐term population persistence of animal‐pollinated plants, and innumerable studies have shown that insufficient service by pollinators results in impaired sexual reproduction (“pollen limitation”). Studies directly addressing the predictors of variation in pollinator service across species or habitats remain comparatively scarce, which limits our understanding of the primary causes of natural variation in pollen limitation. This paper evaluates the importance of pollination‐related features, evolutionary history, and environment as predictors of pollinator service in a large sample of plant species from undisturbed montane habitats in southeastern Spain. Quantitative data on pollinator visitation were obtained for 191 insect‐pollinated species belonging to 142 genera in 43 families, and the predictive values of simple floral traits (perianth type, class of pollinator visitation unit, and visitation unit dry mass), phylogeny, and habitat type were assessed. A total of 24,866 pollinator censuses accounting for 5,414,856 flower‐minutes of observation were conducted on 510 different dates. Flowering patch and single flower visitation probabilities by all pollinators combined were significantly predicted by the combined effects of perianth type (open vs. restricted), class of visitation unit (single flower vs. flower packet), mass of visitation unit, phylogenetic relationships, and habitat type. Pollinator composition at insect order level varied extensively among plant species, largely reflecting the contrasting visitation responses of Coleoptera, Diptera, Hymenoptera, and Lepidoptera to variation in floral traits. Pollinator composition had a strong phylogenetic component, and the distribution of phylogenetic autocorrelation hotspots of visitation rates across the plant phylogeny differed widely among insect orders. Habitat type was a key predictor of pollinator composition, as major insect orders exhibited decoupled variation across habitat types in visitation rates. Comprehensive pollinator sampling of a regional plant community has shown that pollinator visitation and composition can be parsimoniously predicted by a combination of simple floral features, habitat type, and evolutionary history. Ambitious community‐level studies can help to formulate novel hypotheses and questions, shed fresh light on long‐standing controversies in pollination research (e.g., “pollination syndromes”), and identify methodological cautions that should be considered in pollination community studies dealing with small, phylogenetically biased plant species samples.
Transpiration from subarctic deciduous woodlands: Environmental controls and contribution to ecosystem evapotranspiration
Authors: Sabater Ana M. , Ward Helen C. , Hill Timothy C. , Gornall Jemma L. , Wade Thomas J. , Evans Jonathan G. , Prieto‐Blanco Ana , Disney Mathias , Phoenix Gareth K. , Williams Mathew , Huntley Brian , Baxter Robert , Mencuccini Maurizio , Poyatos Rafael
Published: December 2019

Potential land–climate feedbacks in subarctic regions, where rapid warming is driving forest expansion into the tundra, may be mediated by differences in transpiration of different plant functional types. Here, we assess the environmental controls of overstorey transpiration and its relevance for ecosystem evapotranspiration in subarctic deciduous woodlands. We measured overstorey transpiration of mountain birch canopies and ecosystem evapotranspiration in two locations in northern Fennoscandia, having dense (Abisko) and sparse (Kevo) overstories. For Kevo, we also upscale chamber‐measured understorey evapotranspiration from shrubs and lichen using a detailed land cover map. Subdaily evaporative fluxes were not affected by soil moisture and showed similar controls by vapour pressure deficit and radiation across sites. At the daily timescale, increases in evaporative demand led to proportionally higher contributions of overstorey transpiration to ecosystem evapotranspiration. For the entire growing season, the overstorey transpired 33% of ecosystem evapotranspiration in Abisko and only 16% in Kevo. At this latter site, the understorey had a higher leaf area index and contributed more to ecosystem evapotranspiration compared with the overstorey birch canopy. In Abisko, growing season evapotranspiration was 27% higher than precipitation, consistent with a gradual soil moisture depletion over the summer. Our results show that overstorey canopy transpiration in subarctic deciduous woodlands is not the dominant evaporative flux. However, given the observed environmental sensitivity of evapotranspiration components, the role of deciduous trees in driving ecosystem evapotranspiration may increase with the predicted increases in tree cover and evaporative demand across subarctic regions.
Facilitation of an invader by a native habitat‐former increases along interacting gradients of environmental stress
Authors: Uyà Marc , Bulleri Fabio , Wright Jeffrey T. , Gribben Paul E.
Published: December 2019

Native habitat‐forming species can facilitate invasion by reducing environmental stress or consumer pressure. However, the intensity of one stressor along a local gradient may differ when expanding the scale of observation to encompass major variations in background environmental conditions. In this study, we determined how facilitation of the invasive porcelain crab, Petrolisthes elongatus, by the native tube‐forming serpulid, Galeolaria caespitosa, varied with environmental gradients at local (tidal height) and larger (wave exposure) spatial scales. G. caespitosa constructs a complex calcareous matrix on the underside of intertidal boulders and we predicted that its positive effects on P. elongatus density would increase in intensity with shore height and be stronger at wave‐sheltered than wave‐exposed locations. To test these predictions, we conducted two experiments. First, we determined the effects of serpulid presence (boulders with live or dead serpulid matrix vs. bare boulders) at six shore heights that covered the intertidal distribution of P. elongatus. Second, we determined the effects of serpulid presence (present vs. absent), shore height (high vs. low) and wave exposure (sheltered vs. exposed) on crabs across six locations within the invaded range in northern Tasmania, Australia. In Experiment 1, the presence of serpulids (either dead or alive) enhanced P. elongatus densities at all shore heights, with facilitation intensity (as determined by a relative interaction index; RII) tending to increase with shore height. In Experiment 2, serpulids facilitated P. elongatus across shore heights and wave exposures, although crab densities were lower at high shore levels of wave‐sheltered locations. However, the intensity of crab facilitation by serpulids was greater on wave‐sheltered than on wave‐exposed shores, but only at the high shore level. This study demonstrates that local effects of native habitat‐formers on invasive species are dependent on prevailing environmental conditions at larger spatial scales and that, under more stressful conditions, invaders become increasingly reliant on positive interactions with native habitat‐formers. Increased strength of local‐scale facilitation by native species, dampening broader scale variations in environmental stressors, could enhance the ability of invasive species to establish self‐sustaining populations in the invaded range.
Limits to polycentricity? Institutional layering and policy feedbacks of building energy performance requirements in Sweden
Authors: Smedby Nora
Published: December 2019

Local governments have come to play an increasingly active role in addressing current environmental challenges. In addition to improving the environmental performance of a specific city, such initiatives can potentially spur policy change at other levels of government and thereby contribute to the addressing of global environmental challenges. This type of interplay between local and higher levels of government has been insufficiently addressed by environmental governance research. This study addresses this research gap by looking at the case of regulatory energy performance requirements on buildings in Sweden. Through a case study methodology, the research turns to policy documents and interviews. The research shows how local energy performance requirements on buildings provided tensions that impeded their own longevity but contributed to raising ambitions in national regulation. The research contributes to work on polycentric governance by accounting for the existence of hierarchies through the use of concepts from historical institutionalism. In this regard, the study suggests that governance initiatives are prone to institutional layering that, through policy feedback processes, conditions their impact in terms of reaching overarching policy goals. The research is important as it adds empirical substance to the discussion on the potential and limits of local governments in addressing current environmental challenges.
Sex‐ and age‐related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long‐Term Registry
Authors: Lainščak Mitja , Milinković Ivan , Polovina Marija , Crespo‐Leiro Marisa G. , Lund Lars H. , Anker Stefan D. , Laroche Cécile , Ferrari Roberto , Coats Andrew J.S. , McDonagh Theresa , Filippatos Gerasimos , Maggioni Aldo P. , Piepoli Massimo F. , Rosano Giuseppe M.C. , Ruschitzka Frank , Simić Dragan , Ašanin Milika , Eicher Jean‐Christophe , Yilmaz Mehmet B. , Seferović Petar M. ,   on behalf of the European Society of Cardiology Heart Failure Long‐Term Registry Investigators Group
Published: December 2019

Aims

This study aimed to assess age‐ and sex‐related differences in management and 1‐year risk for all‐cause mortality and hospitalization in chronic heart failure (HF) patients.

Methods and results

Of 16 354 patients included in the European Society of Cardiology Heart Failure Long‐Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline‐directed medical therapy (GDMT) were high (angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers, beta‐blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P ≤ 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1‐year follow‐up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all‐cause mortality were lower in women than in men (7.1% vs. 8.7%; P = 0.015), as were rates of all‐cause hospitalization (21.9% vs. 27.3%; P < 0.001) and there were no differences in causes of death. All‐cause mortality and all‐cause hospitalization increased with greater age in both sexes. Sex was not an independent predictor of 1‐year all‐cause mortality (restricted to patients with LVEF ≤45%). Mortality risk was significantly lower in patients of younger age, compared to patients aged >75 years.

Conclusions

There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all‐cause mortality in patients with LVEF ≤45%.
A randomised, double‐blind, placebo‐controlled trial of metformin on myocardial efficiency in insulin‐resistant chronic heart failure patients without diabetes
Authors: Larsen Anders Hostrup , Jessen Niels , Nørrelund Helene , Tolbod Lars Poulsen , Harms Hendrik Johannes , Feddersen Søren , Nielsen Flemming , Brøsen Kim , Hansson Nils Henrik , Frøkiær Jørgen , Poulsen Steen Hvitfeldt , Sörensen Jens , Wiggers Henrik
Published: December 2019

Aims

The present study tested the hypothesis that metformin treatment may increase myocardial efficiency (stroke work/myocardial oxygen consumption) in insulin‐resistant patients with heart failure and reduced ejection fraction (HFrEF) without diabetes.

Methods and results

Thirty‐six HFrEF patients (ejection fraction 37 ± 8%; median age 66 years) were randomised to metformin (n = 19) or placebo (n = 17) for 3 months in addition to standard heart failure therapy. The primary endpoint was change in myocardial efficiency expressed as the work metabolic index (WMI), assessed by 11C‐acetate positron emission tomography and transthoracic echocardiography. Compared with placebo, metformin treatment (1450 ± 550 mg/day) increased WMI [absolute mean difference, 1.0 mmHg·mL·m‐2·106; 95% confidence interval (CI) 0.1 to 1.8; P = 0.03], equivalent to a 20% relative efficiency increase. Patients with above‐median plasma metformin levels displayed greater WMI increase (25% vs. –4%; P = 0.02). Metformin reduced myocardial oxygen consumption (–1.6 mL O2·100 g‐1·min‐1; P = 0.014). Cardiac stroke work was preserved (–2 J; 95% CI –11 to 7; P = 0.69). Metformin reduced body weight (–2.2 kg; 95% CI –3.6 to –0.8; P = 0.003) and glycated haemoglobin levels (–0.2%; 95% CI –0.3 to 0.0; P = 0.02). Changes in resting and exercise ejection fraction, global longitudinal strain, and exercise capacity did not differ between groups.

Conclusion

Metformin treatment in non‐diabetic HFrEF patients improved myocardial efficiency by reducing myocardial oxygen consumption. Measurement of circulating metformin levels differentiated responders from non‐responders. These energy‐sparing effects of metformin encourage further large‐scale investigations in heart failure patients without diabetes.