bluuebunny/crossref_metadata_2025 huggingface dataset:
Early life exposure to air pollution impacts neuronal and glial cell function leading to impaired neurodevelopment
Authors: Morris Rebecca H. , Counsell Serena J. , McGonnell Imelda M. , Thornton Claire
Published: March 2021

The World Health Organisation recently listed air pollution as the most significant threat to human health. Air pollution comprises particulate matter (PM), metals, black carbon and gases such as ozone (O3), nitrogen dioxide (NO2) and carbon monoxide (CO). In addition to respiratory and cardiovascular disease, PM exposure is linked with increased risk of neurodegeneration as well as neurodevelopmental impairments. Critically, studies suggest that PM crosses the placenta, making direct in utero exposure a reality. Rodent models reveal that neuroinflammation, neurotransmitter imbalance and oxidative stress are triggered following gestational/early life exposure to PM, and may be exacerbated by concomitant mitochondrial dysfunction. Gestational PM exposure (potentiated by mitochondrial impairment in the metabolically active neonatal brain) not only impacts neurodevelopment but may sensitise the brain to subsequent cognitive impairment. Having reviewed this field, we conclude that strategies are urgently required to reduce exposure to PM during this sensitive developmental period.
There is no evidence of SARS‐CoV‐2 laboratory origin: Response to Segreto and Deigin (DOI: 10.1002/bies.202000240)
Authors: Tyshkovskiy Alexander , Panchin Alexander Y.
Published: March 2021

The origin of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is the subject of many hypotheses. One of them, proposed by Segreto and Deigin, assumes artificial chimeric construction of SARS‐CoV‐2 from a backbone of RaTG13‐like CoV and receptor binding domain (RBD) of a pangolin MP789‐like CoV, followed by serial cell or animal passage. Here we show that this hypothesis relies on incorrect or weak assumptions, and does not agree with the results of comparative genomics analysis. The genetic divergence between SARS‐CoV‐2 and both its proposed ancestors is too high to have accumulated in a lab, given the timeframe of several years. Furthermore, comparative analysis of S‐protein gene sequences suggests that the RBD of SARS‐CoV‐2 probably represents an ancestral non‐recombinant variant. These and other arguments significantly weaken the hypothesis of a laboratory origin for SARS‐CoV‐2, while the hypothesis of a natural origin is consistent with all available genetic and experimental data.
Facing biology's open questions
Authors: Gomez‐Marin Alex
Published: March 2021

Despite the triumphant rhetoric of mechanistic materialism, current biology has no shortage of unsolved fundamental problems. In 1981, seeking a way forward, Rupert Sheldrake proposed the hypothesis of “formative causation” as a unifying organizing principle of life. Expanding the concept of morphogenetic fields, Sheldrake posited a spatio‐temporal connection termed “morphic resonance” whereby the more often a self‐organizing process takes place, the easier it will be for it to take place in the future. After initial acclaim, his project was quickly met with dogmatic skepticism, dismissed as scientific heresy, and ultimately ignored. Forty years later, the experimental implications of his ideas remain largely untested. Visionary or not, Sheldrake's case illustrates the conceptual resistance of the scientific enterprise to revise its own deepest theoretical commitments. Beyond career‐building selection pressures, young researchers need to be presented with the major questions in their field and encouraged to entertain radically alternative points of view. Science is what scientists make of it.
Confident identification of subgroups from SNP testing in RCTs with binary outcomes
Authors: Wei Yue , Wang Xinjun , Chew Emily Y. , Ding Ying
Published: March 2021

In modern drug development, genotype information becomes more frequently collected in randomized controlled trials (RCTs) for individualized risk prediction and personalized medicine development. Finding single nucleotide polymorphisms (SNPs) that are predictive of differential treatment efficacy, measured by a clinical outcome, is fundamentally different and more challenging than the traditional association test for a quantitative trait. With the objective to confidently identify and infer genetic subgroups with enhanced treatment efficacy from a large RCT for an eye disease, age‐related macular degeneration (AMD), where the clinical endpoint is binary (progressed or not), we propose a novel SNP‐testing procedure for binary clinical outcomes. Specifically, we formulate four contrasts to simultaneously assess all possible genetic effects on a logic‐respecting efficacy measure, the relative risk (between treatment and control). Our method controls both within‐ and across‐SNP multiplicity rigorously. We then use real genotype data to perform chromosome‐wide simulations to evaluate our method performance and to provide practical recommendations. Finally, we apply the proposed method to perform a genome‐wide SNP testing for the AMD trial and successfully identify multiple gene regions with genetic subgroups exhibiting enhanced efficacy in terms of decreasing the AMD progression rate.
Hyperosmolality in CHO culture: Effects on cellular behavior and morphology
Authors: Romanova Nadiya , Niemann Tarek , Greiner Johannes F. W. , Kaltschmidt Barbara , Kaltschmidt Christian , Noll Thomas
Published: March 2021

Exposure of Chinese hamster ovary cells (CHO) to highly concentrated feed solution during fed‐batch cultivation is known to result in an unphysiological osmolality increase (>300 mOsm/kg), affecting cell physiology and morphology. Extending previous observation on osmotic adaptation, the present study investigates for the first time potential effects of hyperosmolality on CHO cells on both population and single‐cell level. We intentionally exposed CHO cells to hyperosmolality of up to 545 mOsm/kg during fed‐batch cultivation. In concordance with existing research data, hyperosmolality‐exposed CHO cells showed a nearly triplicated volume accompanied by ablation of proliferation. On the molecular level, we observed a strong hyperosmolality‐dependent increase in mitochondrial activity in CHO cells compared to control. In contrast to mitochondrial activity, hyperosmolality‐dependent proliferation arrest of CHO cells was not accompanied by DNA accumulation or caspase‐3/7‐mediated apoptosis. Notably, we demonstrate for the first time a formation of up to eight multiple, small nuclei in single hyperosmolality‐stressed CHO cells. The here presented observations reveal previously unknown hyperosmolality‐dependent morphological changes in CHO cells and support existing data on the osmotic response in mammalian cells.
A mobile technology‐based cooperative learning platform for undergraduate biology courses in common college classrooms
Authors: Zhou Chun , Lewis Matthew
Published: March 2021

As a high‐impact educational practice, cooperative learning uses a structured group study to promote students' active learning. Currently, it lacks economical yet effective tools to facilitate the interactive nature of structured cooperative learning in regular classrooms. Here, we have established a mobile technology‐based cooperative learning (MBCL) platform that comprises the 2018 iPad, Apple Pencil, LiveBoard, Google Forms, and Google Drive. We tested the MBCL platform in multiple undergraduate biology courses. During semester‐long MBCL studies, the students engaged in cooperative learning to discuss a real‐life issue or chapter‐based contents. With the MBCL platform, the students' group study processes were shown on shared, visible electronic whiteboards that were updated in real‐time, generating visible thinking and instant, interactive communication. The instructor was able to guide the students promptly to conduct knowledge integration and knowledge synthesis using tables and diagrams. The deep learning outcome was evident in the examples and quantitative analyses of students' whiteboard study results and team presentations. Thus, integrating innovative mobile technologies into high‐impact teaching practices, exemplified by the MBCL platform, promotes deep learning in higher education.
The Arctic Environmental Responsibility Index: A method to rank heterogenous extractive industry companies for governance purposes
Authors: Overland Indra , Bourmistrov Anatoli , Dale Brigt , Irlbacher‐Fox Stephanie , Juraev Javlon , Podgaiskii Eduard , Stammler Florian , Tsani Stella , Vakulchuk Roman , Wilson Emma C.
Published: March 2021

The Arctic Environmental Responsibility Index (AERI) covers 120 oil, gas, and mining companies involved in resource extraction north of the Arctic Circle in Alaska, Canada, Greenland, Finland, Norway, Russia, and Sweden. It is based on an international expert perception survey among 173 members of the International Panel on Arctic Environmental Responsibility (IPAER), whose input is processed using segmented string relative ranking (SSRR) methodology. Equinor, Total, Aker BP, ConocoPhillips, and BP are seen as the most environmentally responsible companies, whereas Dalmorneftegeophysica, Zarubejneft, ERIELL, First Ore‐Mining Company, and Stroygaz Consulting are seen as the least environmentally responsible. Companies operating in Alaska have the highest average rank, whereas those operating in Russia have the lowest average rank. Larger companies tend to rank higher than smaller companies, state‐controlled companies rank higher than privately controlled companies, and oil and gas companies higher than mining companies. The creation of AERI demonstrates that SSRR is a low‐cost way to overcome the challenge of indexing environmental performance and contributing to environmental governance across disparate industrial sectors and states with divergent environmental standards and legal and political systems.
MET transcriptional regulator/serine peptidase inhibitor kunitz type 1 panel operating through HGF/c‐MET axis as a prognostic signature in pan‐cancer
Authors: Xiang Yi , Liang Bishan , Jiang Yu , Sun Fei , Zhao Yang , Wu Qijing , Hu Xingbin , Liu Yajing , Huang Qiong , Liao Wangjun , Yao Zhiqi , Li Shaowei , Shi Min
Published: March 2021

Dysregulations in transcription factors (TFs) and their genetic products play important roles in tumorigenesis, tumor progression and metastasis. However, prognostic value of the transcriptional regulatory networks in different cancers has not been investigated in depth. The purpose of our study was to identify and validate a potential predictive signature that combines TFs and their regulatory products in eight solid tumors. We used bioinformatics analysis to identify MET Transcriptional Regulator (MACC1) and Serine Peptidase Inhibitor Kunitz Type 1 (SPINT1) as candidate TFs with the respective downstream regulatory proteins for patient prognosis in pan‐cancer. Subsequent molecular analysis of clinical gastric cancer tissue samples further verified the negative correlation between MACC1 and SPINT1. Further, we showed that mechanistically, MACC1/SPINT1 mediated the pro‐HGF proteolysis and c‐Met phosphorylation in HGF/c‐MET signaling pathway. Kaplan‐Meier plots and receiver operating characteristics analysis revealed that the two‐gene signature combining MACC1 with SPINT1 was effective in predicting survival in all eight cancer cohorts tested. In conclusion, our study clarified the regulatory relationship between MACC1 and SPINT1 in the context of the HGF/c‐MET signaling pathway and determined MACC1/SPINT1 panel as a valuable signature for the prediction of prognosis in patients for multiple solid cancer types.
Operational Strategies to Improve the Performance and Long‐Term Cyclability of Intermediate Temperature Sodium‐Sulfur Batteries
Authors: Kandhasamy Sathiyaraj , Nikiforidis Georgios , Jongerden Gert Jan , Jongerden Ferdy , van de Sanden Mauritius C. M. , Tsampas Mihalis N.
Published: March 2021

Based on the preliminary investigation of the intermediate temperature sodium‐sulfur (IT‐NaS) battery (150 °C), herein we advance this energy storage system, by retuning the catholyte formulation; namely i) concentration, ii) layer thickness, and iii) cut‐off limits during galvanostatic charge‐discharge cycling, lowering the operating temperature and improving cell design. The systematic implementation of these strategies boosted the cell performance significantly, delivering 112 mAh/g‐sulfur, 90 % of its theoretical specific capacity (125 mAh/g‐sulfur), and 50 deep reversible charge‐discharge cycles with coulombic and round‐trip energy efficiencies of 97±3 % and 73±4 %, respectively. Along with the stability and improvement of cycle life, this study demonstrates, for the first time, the practicality of the tubular IT‐NaS technology at a temperature as low as 125 °C.
Electrochemical Tri‐ and Difluoromethylation‐Triggered Cyclization Accompanied by the Oxidative Cleavage of Indole Derivatives
Authors: Yuan Xin , Cui Yu‐Sheng , Zhang Xin‐Peng , Qin Long‐Zhou , Sun Qi , Duan Xiu , Chen Lin , Li Guigen , Qiu Jiang‐Kai , Guo Kai
Published: March 2021

Considering their unique roles in organic synthesis, and pharmaceutical and agrochemical applications, the development of fluoroalkylation, cyclization, and indole oxidative cleavage are important topics. Herein, an unprecedented electrochemical tri‐ and difluoromethylation/cyclization/indole oxidative cleavage process occurring in an undivided cell is presented. The protocol employs a readily prepared Langlois reagent as the fluoroalkyl source, affording a series of tri‐ or difluoromethylated 2‐(2‐acetylphenyl)isoquinoline‐1,3‐diones in good yields with excellent stereoselectivity. It is worth noting that this new methodology merges the fluoroalkylation/cyclization of N‐substituted acrylamide alkenes with the oxidative cleavage of an indole C(2)=C(3) bond under external oxidant‐free conditions.
Diastereo‐ and Enantioselective Mannich/Cyclization Cascade Reaction Access to Chiral Benzothiazolopyrimidine Derivatives
Authors: Zhang Yan , Yang Jia‐Hui , Xia Ying‐Qi , Dong Lin , Chen Fen‐Er
Published: March 2021

An efficient asymmetric Mannich/cyclization cascade strategy was established from 2‐benzothiazolimines with N‐acylpyrazoles to provide optical active benzothiazolopyrimidine derivatives using a copper‐based complex. The mild cascade process constructed various structurally diverse products with broad scope of substrates together with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities (up to 99:1 d.r.).
An efficient numerical model for nonisothermal fluid flow through porous media
Authors: Dastkhan Yaghoub , Kazemi Alireza
Published: March 2021

Temperature transient analysis has gained increasing attention in recent years due to the widespread application of downhole temperature sensors with high resolution and accuracy. With the fast, high resolution, and accurate temperature sensors in oil and gas wells, there is a need for the models and methods for analysis of transient temperature data in order to identify production and well completion problems and calculation of reservoir properties. Although there are many proposed analytical and numerical models, a majority of models are not applicable in practice due to limitations in basic assumptions and computational time. A procedure is proposed for numerical simulation of transient variations of sandface pressure and temperature. The fluid flow and energy equations are decoupled and solved simultaneously and the dependency of all properties on pressure and temperature is treated by nested iteration loops. The solution was compared with some analytical and numerical methods and was found as a computationally efficient calculation method. The benefit of the proposed method is its versatility, simplicity, speed, and ease of implementation in a programming language which can be used in conjunction with well test analysis models to correct for the effect of temperature and also constrain the uncertainty of reservoir parameters. It can also be embedded in compositional and reactive models to widen their applicability and accuracy.
Real‐time dynamic energy efficiency evaluation and analysis of industrial processes based on multi‐objective state transition algorithm with reference vector
Authors: Wang Yalin , Li Ling , Wu Dongzhe , Yuan Xiaofeng
Published: March 2021

As one of the main costs of industrial processes, energy consumption is an essential issue that cannot be ignored in the sustainable development of enterprises. Effective energy efficiency evaluation is important, but also challenging. The conventional method typically uses statistic standard for evaluation. However, infected by the market, the raw materials of an industrial process often fluctuate, which will affect the evaluation standard of energy efficiency. Taking this into account will improve the evaluation performance. To this end, a real‐time dynamic energy efficiency evaluation and analysis method based on multi‐objective state transition algorithm with reference vector (RV‐MOSTA) is proposed to address the energy efficiency evaluation problem. The core of the paper is to realize the dynamic energy efficiency evaluation of multiple indicators considering inlet conditions of industrial processes. Therefore, a systematic set of special indicators are firstly developed for the energy efficiency evaluation. Then, RV‐MOSTA is proposed to determine the evaluation standard, which considers the influence of imported inlet conditions and the optimization of multiple evaluation indicators. Furthermore, a degeneration diagnosis method by means of linear discriminant analysis (LDA) can identify the key variables that lead to energy efficiency degeneration. The proposed method is verified through numerical example and an industrial hydrocracking process.
Predictive value of the atherogenic index of plasma for chronic total occlusion before coronary angiography
Authors: Liu Tong , Liu Jinghua , Wu Zheng , Lv Yun , Li Wenzheng
Published: March 2021

Background

The atherogenic index of plasma (AIP) is calculated by logarithmic transformation of the ratio of triglyceride (TG) and high‐density lipoprotein cholesterol (HDL‐C) concentrations. Although previous studies have demonstrated that the AIP is associated with coronary artery disease, its association with chronic total occlusion (CTO) requires elucidation.

Hypothesis

We hypothesized that the AIP would have diagnostic value in cases of CTO and could be used to predict adverse events.

Methods

This study involved 1131 inpatients who underwent coronary angiography. Data on demographic and clinical characteristics, coronary artery stenosis rated by the Gensini score, and clinical assessment by the Global Registry of Acute Coronary Events and thrombolysis in myocardial infarction (TIMI) scores were collected by cardiovascular doctors. Serum AIP values were evaluated by logarithmic transformation of the ratio of TG and HDL‐C concentrations. The correlations of AIP values with clinical parameters were assessed, and receiver‐operating characteristic curves were constructed for CTO diagnosis.

Results

Overall, 1131 inpatients were assigned to the CTO (n = 398) and control (n = 733) groups. Compared with the control group, the CTO group showed a significantly higher AIP (p < .05). The AIP was positively correlated with body mass index, the TIMI score, the Gensini score, and stent length and was effective for the diagnosis and risk assessment of patients with CTO. Multivariate logistic regression analyses revealed that the AIP was an independent risk factor for CTO. The findings suggest that the AIP could predict the presence of CTO and disease severity.
Piperazine, a Key Substructure for Antidepressants: Its Role in Developments and Structure‐Activity Relationships
Authors: Kumar Ravi Ranjan , Sahu Bhaskar , Pathania Shelly , Singh Pankaj Kumar , Akhtar M. Jawaid , Kumar Bhupinder
Published: March 2021

Depression is the single largest contributor to global disability with a huge economic and social burden on the world. There are a number of antidepressant drugs on the market, but treatment‐resistant depression and relapse of depression in a large number of patients have increased problems for clinicians. One peculiarity observed in most of the marketed antidepressants is the presence of a piperazine substructure. Although piperazine is also used in the optimization of other pharmacological agents, it is almost extensively used for the development of novel antidepressants. One common understanding is that this is due to its favorable CNS pharmacokinetic profile; however, in the case of antidepressants, piperazine plays a much bigger role and is involved in specific binding conformations of these agents. Therefore, in this review, a critical analysis of the significance of the piperazine moiety in the development of antidepressants has been performed. An overview of current developments in the designing and synthesis of piperazine‐based antidepressants (2015 onwards) along with SAR studies is also provided. The various piperazine‐based therapeutic agents in early‐ or late‐phase human testing for depression are also discussed. The preclinical compounds discussed in this review will help researchers understand how piperazine actually influences the design and development of novel antidepressant compounds. The SAR studies discussed will provide crucial clues about the structural features and optimizations required to enhance the efficacy and potency of piperazine‐based antidepressants.
High Performance of Single‐atom Catalyst Pd1/MgO for Semi‐hydrogenation of Acetylene to Ethylene in Excess Ethylene
Authors: Guo Yalin , Qi Haifeng , Su Yang , Jiang Qike , Cui Yi‐Tao , Li Lei , Qiao Botao
Published: March 2021

Semi‐hydrogenation of acetylene in excess ethylene is important in purifying alkene streams. Industrially used Pd‐based catalysts are highly active but suffer from low selectivity. Supported Pd single‐atom catalysts (SACs) are promising in this reaction but the fabrication of highly stable Pd SACs remains a grand challenge. In this work, we have developed a stable MgO supported Pd SAC by ball‐milling method which showed good catalytic performance. The strong interaction between Pd atoms and MgO support not only inhibited the aggregation of Pd atoms, but also resulted in a high chemical state of Pd which may facilitate the adsorption as well as reactivity of acetylene. In addition, the isolation nature of the SAC is in favour of ethylene desorption, giving rise to a high selectivity. This work provided a good example to develop highly stable Pd SAC for catalytic semi‐hydrogenation reaction with high efficiency.
Minkowski Sommon Feature Map‐based Densely Connected Deep Convolution Network with LSTM for academic performance prediction
Authors: Ramanathan Kaviyarasi , Thangavel Balasubramanian
Published: March 2021

Student academic performance prediction plays a major role in the current educational systems to improve the quality of education. The conventional single classifier‐based predictive analysis is not efficient to provide accurate results. In this paper, a novel technique called Minkowski Sommon Feature Map Densely connected Deep Convolution Network with LSTM (MSFMDDCN‐LSTM) is introduced to predict the academic performance of students with higher accuracy and lesser time consumption. The MSFMDDCN‐LSTM technique uses a densely connected deep convolution network to learn the given input for accurate prediction. The student activities are collected and stored in the organization dataset. The MSFMDDCN‐LSTM technique starts with the data collection followed by performing the attributes selection and classification. The collected data are given to input layer to predict the students' academic achievement at the end of study program. Secondly, the importance of numerous dissimilar attributes or “features” is considered for student performance prediction using steepest descent Minkowski sommon mapping. After that, the classification is performed using LSTM to classify the input instances for accurate prediction. Finally, the classification results are observed in the output layer. The quantitative outcomes inferred that MSFMDDCN‐LSTM technique performs well in terms of achieving higher precision, recall, f‐measure, and lesser time consumption than the state‐of‐the‐art methods.
The Issue of Tissue: Approaches and Challenges to the Light Control of Drug Activity
Authors: Sharma Mayank , Friedman Simon H.
Published: March 2021

Many of the major challenges associated with drug delivery can potentially be addressed by linking drug action to light irradiation. These challenges include the spacing, timing and amount of a drug's activity. Once a drug's activity is linked to light, this activity can be more easily manipulated, because light itself is easy to manipulate. One of the main issues that light control can address is off‐target toxicity. This has the potential to be limited if drugs are activated only in target tissues using light. For drugs that are needed at varying concentrations through the day, varying light has the potential to temporally modulate drug release. Because of these and other advantages, a range of mechanisms for using light to manipulate drug activity has been developed, including photocleavage control, photoconformational control, photothermal control and photodegradation control. These major themes of light control will be described in this minireview, and illustrated with examples. In addition, the issue of tissue light permittivity, arguably the major challenge for the discipline, will be described and analyzed.
Organic‐Inorganic Superlattices of Vanadium Oxide@Polyaniline for High‐Performance Magnesium‐Ion Batteries
Authors: Zuo Chunli , Xiao Yao , Pan Xiaoji , Xiong Fangyu , Zhang Wenwei , Long Juncai , Dong Shijie , An Qinyou , Luo Ping
Published: March 2021

Rechargeable magnesium batteries (RMBs) have attracted significant attention owing to the high energy density and economic viability. However, the lack of suitable cathode materials, owing to the high polarizability of divalent Mg‐ion and slow Mg‐ion diffusion, hinders the development of RMBs. V2O5 is a promising RMBs cathode material, but its limited interlayer spacing is unfavorable for the rapid diffusion of Mg2+, demonstrating unsatisfactory electrochemical performance. In this study, the superlattices of V2O5 and polyaniline (PANI) with expanded interlayer spacing are assembled as the cathode material for RMBs. The intercalation of PANI in the interlayer region of V2O5 significantly improves the reversible capacities, Mg2+ diffusion kinetics, and cycling performance of the PVO cathode. Furthermore, RMBs with PVO as the cathode and Mg metal as the anode deliver high specific capacities. The introduced polyaniline layer not only expands the interlayer spacing of V2O5, but also increases the electrical conductivity. Moreover, ex situ XRD characterization indicates that PVO does not undergo obvious phase transformation with the continuous insertion of Mg2+, which may be ascribed to the π‐conjugated chains of PANI that give flexibility to the structure to improve cycling stability. This study demonstrates that designing organic‐inorganic superlattices is an efficient strategy for developing high‐performance cathode materials for RMBs.
Isolation of plant nuclei for estimation of nuclear DNA content: Overview and best practices
Authors: Loureiro João , Kron Paul , Temsch Eva M. , Koutecký Petr , Lopes Sara , Castro Mariana , Castro Sílvia
Published: March 2021

A critical aspect for obtaining accurate, reliable, and high‐resolution estimates of nuclear DNA content is the release of nuclei from the cytoplasm in sufficient amounts, while maintaining their integrity throughout the analysis, protecting their DNA from degradation by endonucleases, and enabling stoichiometric DNA staining. In embryophytes, the most common method consists of chopping the plant material with a sharp razor blade to release nuclei into an isolation buffer, filtering the homogenate, and staining the nuclei in buffered suspension with a fluorochrome of choice. Despite the recent description of alternative approaches to isolate nuclei, the chopping procedure remains the most widely adopted method, due to its simplicity, rapidity, and effectiveness. In this review article, we discuss the specifics of nuclei isolation buffers and the distorting effects that secondary metabolites may have in nuclear suspensions and how to test them. We also present alternatives to the chopping procedure, options for filtering and fluorochromes, and discuss the applications of these varied approaches. A summary of the best practices regarding the isolation of plant nuclei for the estimation of nuclear DNA content is also provided.
Natural variation in colony inbreeding does not influence susceptibility to a fungal pathogen in a termite
Authors: Aguero Carlos M. , Eyer Pierre‐André , Martin Jason S. , Bulmer Mark S. , Vargo Edward L.
Published: March 2021

Reduced genetic diversity through inbreeding can negatively affect pathogen resistance. This relationship becomes more complicated in social species, such as social insects, since the chance of disease transmission increases with the frequency of interactions among individuals. However, social insects may benefit from social immunity, whereby individual physiological defenses may be bolstered by collective‐level immune responses, such as grooming or sharing of antimicrobial substance through trophallaxis. We set out to determine whether differences in genetic diversity between colonies of the subterranean termite, Reticulitermes flavipes, accounts for colony survival against pathogens. We sampled colonies throughout the United States (Texas, North Carolina, Maryland, and Massachusetts) and determined the level of inbreeding of each colony. To assess whether genetically diverse colonies were better able to survive exposure to diverse pathogens, we challenged groups of termite workers with two strains of a pathogenic fungus, one local strain present in the soil surrounding sampled colonies and another naïve strain, collected outside the range of this species. We found natural variation in the level of inbreeding between colonies, but this variation did not explain differences in susceptibility to either pathogen. Although the naïve strain was found to be more hazardous than the local strain, colony resistance was correlated between two strains, meaning that colonies had either relatively high or low susceptibility to both strains regardless of their inbreeding coefficient. Overall, our findings may reflect differential virulence between the strains, immune priming of the colonies via prior exposure to the local strain, or a coevolved resistance toward this strain. They also suggest that colony survival may rely more upon additional factors, such as different behavioral response thresholds or the influence of a specific genetic background, rather than the overall genetic diversity of the colony.
Stoichiometric traits (N:P) of understory plants contribute to reductions in plant diversity following long‐term nitrogen addition in subtropical forest
Authors: Wu Jianping , Shen Fangfang , Thompson Jill , Liu Wenfei , Duan Honglang , Bardgett Richard D.
Published: March 2021

Nitrogen enrichment is pervasive in forest ecosystems, but its influence on understory plant communities and their stoichiometric characteristics is poorly understood. We hypothesize that when forest is enriched with nitrogen (N), the stoichiometric characteristics of plant species explain changes in understory plant diversity. A 13‐year field experiment was conducted to explore the effects of N addition on foliar carbon (C): N: phosphorus (P) stoichiometry, understory plant species richness, and intrinsic water use efficiency (iWUE) in a subtropical Chinese fir forest. Four levels of N addition were applied: 0, 6, 12, and 24 g m−2 year−1. Individual plant species were categorized into resistant plants, intermediate resistant plants, and sensitive plants based on their response to nitrogen addition. Results showed that N addition significantly decreased the number of species, genera, and families of herbaceous plants. Foliar N:P ratios were greater in sensitive plants than resistant or intermediate resistant plants, while iWUE showed an opposite trend. However, no relationship was detected between soil available N and foliar N, and soil N:P and foliar N:P ratios. Our results indicated that long‐term N addition decreased the diversity of understory plants in a subtropical forest. Through regulating water use efficiency with N addition, sensitive plants change their N:P stoichiometry and have a higher risk of mortality, while resistant plants maintain a stable N:P stoichiometry, which contributes to their survival. These findings suggest that plant N:P stoichiometry plays an important role in understory plant performance in response to environmental change of N.
You are welcome here: A practical guide to diversity, equity, and inclusion for undergraduates embarking on an ecological research experience
Authors: McGill Bonnie M. , Foster Madison J. , Pruitt Abagael N. , Thomas Samantha Gabrielle , Arsenault Emily R. , Hanschu Janaye , Wahwahsuck Kynser , Cortez Evan , Zarek Kaci , Loecke Terrance D. , Burgin Amy J.
Published: March 2021

As we build a more diverse, equitable, and inclusive culture in the ecological research community, we must work to support new ecologists by empowering them with the knowledge, tools, validation, and sense of belonging in ecology to succeed. Undergraduate research experiences (UREs) are critical for a student's professional and interpersonal skill development and key for recruiting and retaining students from diverse groups to ecology. However, few resources exist that speak directly to an undergraduate researcher on the diversity, equity, and inclusion (DEI) dimensions of embarking on a first research experience. Here, we write primarily for undergraduate readers, though a broader audience of readers, especially URE mentors, will also find this useful. We explain many of the ways a URE benefits undergraduate researchers and describe how URE students from different positionalities can contribute to an inclusive research culture. We address three common sources of anxiety for URE students through a DEI lens: imposter syndrome, communicating with mentors, and safety in fieldwork. We discuss the benefits as well as the unique vulnerabilities and risks associated with fieldwork, including the potential for harassment and assault. Imposter syndrome and toxic field experiences are known to drive students, including students from underrepresented minority groups, out of STEM. Our goal is to encourage all students, including those from underrepresented groups, to apply for UREs, build awareness of their contributions to inclusion in ecology research, and provide strategies for overcoming known barriers.
Resource utilization and costs among patients with heart failure with reduced ejection fraction following a worsening heart failure event
Authors: Givertz Michael M. , Yang Mei , Hess Gregory P. , Zhao Bin , Rai Ashwin , Butler Javed
Published: March 2021

Aims

The aim of this study is to characterize healthcare resource utilization and costs in patients with heart failure with reduced ejection fraction (HFrEF) following a worsening heart failure event.

Methods and results

This was a retrospective observational cohort analysis. Patients with HFrEF were identified from the PINNACLE Registry and linked to a nationwide pharmacy and medical claims database. Worsening heart failure was defined as stable heart failure with a subsequent hospitalization and/or intravenous diuretic therapy. Healthcare resource use and costs in 2015 US dollars were analysed for dispensed prescriptions, outpatient encounters, and hospital encounters. Among 11 064 patients with HFrEF, 3087 (27.9%) experienced a worsening heart failure event during an average follow‐up of 973 days. During the first 30 days after the worsening event, 19.8% of patients had hospital readmissions with heart failure as the primary or secondary diagnosis. During that same time period, mean per patient heart failure‐related healthcare resource use included 1.3 prescriptions, 0.5 practitioner visits, and 0.5 hospital encounters (admissions, observations, or emergency care), for an average total medical cost of $8779 per patient including $5359 in heart failure‐related costs. During the first year following worsening heart failure onset, mean per patient total and heart failure‐related costs were $62 615 and $35 329, respectively.

Conclusions

The economic burden following a worsening heart failure event calls for further review of methods to prevent progressive disease, improve adherence to guideline‐directed therapy, and develop novel treatments and care strategies to moderate further progression.
2‐(8‐Iodonaphthalen‐1‐yl)‐Substituted Nitronyl Nitroxide: Suppressed Reactivity of Iodine Atom and Unusual Temperature Dynamics of the EPR Spectrum
Authors: Tretyakov Evgeny V. , Lomanovich Konstantin A. , Bagryanskaya Elena G. , Romanenko Galina V. , Bogomyakov Artem S. , Zueva Ekaterina M. , Petrova Maria M. , Dmitriev Alexey A. , Gritsan Nina P.
Published: March 2021

While developing methods for obtaining high‐spin graphene nanostructures, we carried out a model cross‐coupling reaction between 1,8‐diiodonaphthalene and an organogold derivative of a nitronyl nitroxide. It was found that only one iodine atom reacted, leading to the corresponding 8‐iodonaphthalen‐1‐yl‐substituted nitronyl nitroxide. The latter was successfully isolated as two polymorphic modifications, whose X‐ray structural analysis revealed a strong distortion of the paramagnet's geometry in comparison with a noniodinated analog. Moreover, the spatial proximity of the heavy iodine atom and the paramagnetic moiety resulted in unprecedented temperature dynamics of the EPR spectrum. To clarify these dynamics, quantum chemical calculations were performed using the exact two‐component relativistic X2C method with the self‐consistent account of spin‐orbit coupling in conjunction with the B3LYP functional and relativistic STO‐type basis set. These computations predicted a reasonableaiso(127I) value that can affect the EPR spectrum. Substitution of the second iodine atom would lead to the formation of a diradical with a 1,8‐naphthalenediyl bridge, whose structure and magnetic properties were analyzed at the DFT level. Two stable conformations of the diradical with strongly distorted geometry were identified. In both conformations, calculations predict a ferromagnetic exchange between the paramagnetic centers withJ=8 and 14 cm−1(H=−2 J⋅S1S2).
Debenzylative Sulfonylation of Tertiary Benzylamines Promoted by Visible Light
Authors: Fu Ying , Wu Qing‐Kui , Du Zhengyin
Published: March 2021

An efficient, general, inexpensive, and environmentally friendly photosynthesis of sulfonamides via visible light promoted debenzylative sulfonylation of tertiary benzylamines is described. Compared to the traditional S−N coupling reactions, which are promoted by oxidative C−N bond cleavage of symmetrical tertiary alkylamines, this strategy provides a selective C−N bond cleavage protocol and avoids the use of transition‐metal, explosive oxidants, and ligands.
The variability of antidune morphodynamics on steep slopes
Authors: Pascal Ivan , Ancey Christophe , Bohorquez Patricio
Published: March 2021

Steep streams on rough beds are generally characterised by supercritical flow conditions under which antidunes can develop and migrate over time. In this paper, we present flume experiments that we conducted to investigate the variability of antidune geometry and migration celerity, a variability observed even under steady‐state conditions. Quantifying this variability is important for river morphodynamics, hydraulics and paleohydraulics. We imposed moderate to intense bedload transport rates at the flume inlet to assess their effects on antidune morphodynamics for near‐constant values of the mean bed slope. The bed elevation profile was monitored for each experiment with high spatial and temporal resolution. Upstream migrating antidunes were observed along most of the flume length. Considering single values for wavelength and celerity was not sufficient to describe the antidune behaviour in these experiments. By using spectral analysis, we identified the variability ranges of bedform shape and celerity. Interestingly, migration celerity increased with increasing antidune wavelength; the opposite trend was reported for dunes in other studies. Antidunes were more uniform and migrated faster for higher sediment feeding rates. Scaling the spectra made it possible to find a general dimensionless relationship between antidune wavelength and celerity. This framework provides a novel method for estimating the mean bedload transport rate in the presence of upstream migrating antidunes.
Influence of physical crust cover on the wind erodibility of soils in the inland Pacific Northwest, USA
Authors: Pi Huawei , Webb Nicholas P. , Huggins David R. , Sharratt Brenton
Published: March 2021

Soil crusts are especially important for agricultural fields in the inland Pacific Northwest where there is a high wind erosion risk due to exposure of fine erodible soils in fallow croplands. The objective of this study was therefore to evaluate the effect of physical soil crust cover on wind erosion and identify critical soil crust cover amounts to control wind erosion. The effect of crust cover of five loessial soils on wind erosion was tested in a wind tunnel. The results indicated that crust cover appeared to have little influence on soil loss until crust cover was > 30%. Soil loss at this percentage of crust cover was 55.04% to 68.08% lower as compared with a soil surface devoid of crust cover for the five soil types. The relationship between soil loss and crust cover appeared to be nearly a linear function, although an exponential function also provided a good fit to the data. With progressive development of a crust cover, the rate of change in soil loss varied among soil types. From 0 to 100% crust cover, the rate of change in soil loss ranged from −312.8 g m−2 for Palouse silt loam to −1449.1 g m−2 for Warden sandy loam. The rate was not only associated with intrinsic soil erodibility, but also crust stability and abrasion flux. Due to the lower intrinsic soil erodibility and greater crust stability, Palouse silt loam crust was characterized by lower flaking potential and limited abrasion flux relative to the other tested soil types. The Single‐event Wind Erosion Evaluation Program (SWEEP) was used to simulate and identify the effect of crust cover on erosion processes. Differences between simulated and measured soil loss suggest that cracks in soil crusts may affect soil loss and should be incorporated into the SWEEP to expand the model capability for representing crusted soils.
Patterns and Trends of Polybrominated Diphenyl Ethers in Bald Eagle Nestlings in Minnesota and Wisconsin, USA
Authors: Route William T. , Dykstra Cheryl R. , Strom Sean M. , Meyer Michael W. , Williams Kelly A.
Published: March 2021

We measured concentrations of up to 17 polybrominated diphenyl ethers (PBDEs) in plasma of 492 bald eagle (Haliaeetus leucocephalus) nestlings between 1995 and 2017 from 12 study areas in Wisconsin and Minnesota, USA. Geometric mean concentrations of the sum of 9 PBDE congeners (∑PBDE) measured across all years ranged from 2.88 to 10.8 µg/L, and nestlings in urban areas had higher concentrations than those in remote locations. Region-wide from 2006 through 2017, we found that ∑PBDEs declined by 3.8% annually and congeners BDE-47, -99, and -100 declined by 5.6 to 6.5%, whereas BDE-153 and -154 had no significant declines. When categorized by waterbody type, nestlings from Great Lakes and river study areas had higher concentrations of ∑PBDEs than those at inland lakes, but river study areas spanned the extremes. From 2006 to 2017, ∑PBDEs declined by 7.3% annually in Great Lakes nestlings and by 3.2% in nestlings along rivers, and increased by 32.7% at inland lakes. Using a longer dataset (1995–2015), we found that ∑PBDEs declined in Lake Superior nestlings by 3.3% annually. Our results show that PBDEs declined in bald eagle nestling plasma in most study areas since PBDE production was reduced, but that concentrations remain high near urban centers and that trends differ by congener, study area, and waterbody type. Environ Toxicol Chem 2021;40:1606–1618. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Abstract

As apex predators, bald eagles can serve as biosentinels of environmental contamination to aquatic environments. Blood plasma from bald eagle nestlings is particularly useful for measuring the extent of local contamination. PBDE = polybrominated diphenyl ether. For study area acronym abbreviations, see Table 1 footnote.
Metabarcoding Reveals Changes in Benthic Eukaryote and Prokaryote Community Composition along a Tropical Marine Sediment Nickel Gradient
Authors: Gillmore Megan L. , Golding Lisa A. , Chariton Anthony A. , Stauber Jenny L. , Stephenson Sarah , Gissi Francesca , Greenfield Paul , Juillot Farid , Jolley Dianne F.
Published: March 2021

The Southeast Asia and Melanesia region has extensive nickel (Ni)-rich lateritic regoliths formed from the tropical weathering of ultramafic rocks. As the global demand for Ni continues to rise, these lateritic regoliths are increasingly being exploited for their economic benefit. Mining of these regoliths contributes to the enrichment of coastal sediments in trace metals, especially Ni. The present study used high-throughput sequencing (metabarcoding) to determine changes in eukaryote (18s v7 recombinant DNA [rDNA] and diatom-specific subregion of the 18s v4 rDNA) and prokaryote (16s v4 rDNA) community compositions along a sediment Ni concentration gradient offshore from a large lateritized ultramafic regolith in New Caledonia (Vavouto Bay). Significant changes in the eukaryote, diatom, and prokaryote community compositions were found along the Ni concentration gradient. These changes correlated most with the dilute-acid extractable concentration of Ni in the sediments, which explained 26, 23, and 19% of the variation for eukaryote, diatom, and prokaryote community compositions, respectively. Univariate analyses showed that there was no consistent change in indices of biodiversity, evenness, or richness. Diatom richness and diversity did, however, decrease as sediment acid extractable-Ni concentrations increased. Threshold indicator taxa analysis was conducted separately for each of the 3 targeted genes to detect changes in taxa whose occurrences decreased or increased along the acid extractable-Ni concentration gradient. Based on these data, 46 mg acid extractable-Ni/kg was determined as a threshold value where sensitive species began to disappear. In the case of the estuarine sediments offshore from lateritized ultramafic regolith in New Caledonia, this is recommended as an interim threshold value until further lines of evidence can contribute to a region-specific Ni sediment quality guideline value. Environ Toxicol Chem 2021;40:1892–1905. © 2021 SETAC

Abstract

Benthic community composition changed significantly along a tropical marine sediment nickel gradient in New Caledonia (Vavouto Bay). Based on the disappearance of sensitive taxa, a threshold value of 46 mg acid extractable Ni/kg was determined.