bluuebunny/crossref_metadata_2025 huggingface dataset:
Prudent Choice of Iron‐Based Metal‐Organic Networks for Solvent‐Free CO2 Fixation at Ambient Pressure
Authors: Mitra Antarip , Biswas Tanmoy , Ghosh Sourav , Tudu Gouri , Paliwal Khushboo S. , Ganatra Pragati , Mahalingam Venkataramanan
Published: April 2022

The rising global warming and associated climate change demand efficient tactics to reduce CO2 concentration in the atmosphere. Conversion of epoxides to cyclic carbonates utilizing CO2 is a promising and sustainable approach towards CO2 fixation. However, the inert nature of CO2 and high activation energy requirement for the particular reaction necessitate the use of efficient catalysts. In this work, we have designed and developed a heterogeneous catalyst using catechol functionalized guanidinium based ligands (L1) and Fe(III) ions to perform the CO2 fixation reaction. The resulting amorphous material (Fe−L1) possesses metal‐organic network as revealed through different characterization methods. The optimized catalyst Fe−L1 is efficient for the conversion of a variety of epoxides into their corresponding cyclic carbonates in very good yield (>80 %). The reactions were performed under atmospheric pressure without solvent and external additives (e. g., TBAI or KI). The investigation of the mechanistic pathway indeed validates the synergistic effect of metal and halide ions that leads to the efficient conversion of different epoxides into cyclic carbonates. Furthermore, no significant loss in the catalytic activity of the Fe−L1 is noticed up to six cycles. The post catalytic analyses clearly indicate the robust nature of the catalyst. The developed one component bifunctional catalytic system can pave way towards transition to sustainable carbon capture and conversion.
Highly Efficient and Stereoselective Synthesis of 6,7‐Dideoxy‐β‐d‐ido‐octopyranuronates
Authors: Homayonia Saba , Ling Chang‐Chun
Published: April 2022

6‐Deoxy‐β‐ido‐heptopyranosides are challenging glycosides to synthesize due to their unusual 6‐deoxy‐heptose backbone, rare ido‐configuration and most importantly, the β‐1,2‐cis anomeric linkage. They are found in nature, such as being part of the repeating disaccharide of C. jejuni HS:4 capsular polysaccharides (CPs). Interestingly, the bacterial CPs is found to be partially modified with an O‐methyl phosphoramidate (MeOPN) functionality at the O‐2 or O‐7 position of the 6‐deoxy‐β‐d‐ido‐heptopyranosides. In this work, we report the first synthesis of three analogous of β‐d‐ido‐octopyranosides (1–3) that contain a 6,7‐dideoxy‐functionality and either a terminal methyl ester or carboxylic acid or amide. Since carboxylic acids have been reported as bioisosteres of phosphate group, compound 1–3 can be regarded as carbon‐based bioisosteres of 6‐Deoxy‐β‐ido‐heptopyranoside containing the MeOPN group without a chiral center. Compounds (1–3) were efficiently synthesized from a O‐2 activated β‐d‐galacto‐octopyranuronate (19) that was efficiently converted to the desired β‐d‐ido‐octopyranuronate configuration using an elegant one‐pot process.
Linear mixed models to handle missing at random data in trial‐based economic evaluations
Authors: Gabrio Andrea , Plumpton Catrin , Banerjee Sube , Leurent Baptiste
Published: April 2022

Trial‐based cost‐effectiveness analyses (CEAs) are an important source of evidence in the assessment of health interventions. In these studies, cost and effectiveness outcomes are commonly measured at multiple time points, but some observations may be missing. Restricting the analysis to the participants with complete data can lead to biased and inefficient estimates. Methods, such as multiple imputation, have been recommended as they make better use of the data available and are valid under less restrictive Missing At Random (MAR) assumption. Linear mixed effects models (LMMs) offer a simple alternative to handle missing data under MAR without requiring imputations, and have not been very well explored in the CEA context. In this manuscript, we aim to familiarize readers with LMMs and demonstrate their implementation in CEA. We illustrate the approach on a randomized trial of antidepressants, and provide the implementation code in R and Stata. We hope that the more familiar statistical framework associated with LMMs, compared to other missing data approaches, will encourage their implementation and move practitioners away from inadequate methods.
A novel clinical immune‐related prognostic model predicts the overall survival of mantle cell lymphoma
Authors: Lv Huijuan , Fei Yue , Li Wei , Wang Yi , Wang Jinni , He Jin , Liu Xianming , Li Lanfang , Qiu Lihua , Qian Zhengzi , Zhou Shiyong , Meng Bin , Zhai Qiongli , Ren Xiubao , Zou Dehui , Cai Qingqing , Wang Xianhuo , Zhang Huilai
Published: April 2022

The mantle cell lymphoma (MCL) International Prognostic Index (MIPI) and combined MIPI (MIPI‐c) are commonly used for risk classification of MCL patients. However, these indexes lack immune‐related parameters. The purpose of this study was to develop a novel prognostic model that integrated clinical and immune parameters. A total of 189 patients with newly diagnosed MCL from January 2010 to June 2020 were enrolled in our study. A nomogram and immune‐related prognostic index (IRPI) were established to predict the overall survival (OS) of patients according to univariate and multivariate analyses. Discrimination and calibration were used to compare the prognostic performance of the IRPI, MIPI, and MIPI‐c. External validation was performed based on validation dataset (n = 150) from two other centers. The results for the training dataset indicated that B symptoms, platelet count, B2M level, CD4+ T‐cell count<26.7% and CD8+ T‐cell count>44.2% were predictors for OS. All the prognostic factors were integrated into the nomogram. For the overlap of confidence intervals of each variable, we assigned one point for each factor. The IRPI categorized patients into three risk categories: a score of zero indicated low risk, a score of one or two indicated intermediate risk, and a score of ≥3 indicated high risk. The IRPI showed better discrimination and calibration power than the MIPI and MIPI‐c in the training dataset and validation dataset. The novel IRPI is a refined risk stratification index and reflects the strong complementary prognostic effects between clinical and immune parameters in MCL.
Using dissolved organic matter fluorescence to predict total mercury and methylmercury in forested headwater streams, Sleepers River, VermontUSA
Authors: Shanley James B. , Taylor Vivien F. , Ryan Kevin A. , Chalmers Ann T. , Perdrial Julia , Stubbins Aron
Published: April 2022

Aqueous transport of mercury (Hg) across the landscape is closely linked to dissolved organic matter (DOM). Both quantity and quality of DOM affect Hg mobility, as well as the formation and transport of toxic methylmercury (MeHg), but only a limited number of field studies have investigated Hg and MeHg with respect to specific DOM components. We investigated these interactions at the 41‐ha forested W‐9 catchment at Sleepers River, Vermont, which has a long history of mercury and other biogeochemical research. We examined spatial and temporal patterns of filtered Hg fractions and dissolved organic carbon (DOC) concentration, DOM quality, and major solutes at 12 stream sites within W‐9 and the downstream W‐3 gage (837 ha) over five sampling campaigns including a large (79 mm) fall storm, spring snowmelt, and three seasonally contrasting base flow periods. Filtered total Hg (THg), MeHg, and DOC concentrations increased in order base flow < snowmelt < fall storm, except that MeHg remained at baseflow levels during snowmelt. Ranges of median concentrations across sites for the five campaigns were THg, <0.2–4.1 ng L−1; MeHg, <0.03–0.45 ng L−1; and DOC, 0.8–14.0 mg L−1. Humic‐like DOM fluorescence components, as determined by parallel factor analysis (PARAFAC), dominated the fluorescence across sites and sampling campaigns. THg correlated strongly (r > 0.94) with these humic components, but even more strongly with bulk DOC and absorbance at 254 nm (UV254;r > 0.96), and less strongly with protein‐like DOM (0.7 < r < 0.9). MeHg correlated in the same order but less strongly with humic‐ (0.8 < r < 0.9) and protein‐like (0.6 < r < 0.8) DOM. MeHg increased in summer, potentially in response to enhanced microbial production in warmer periods. MeHg formation may have been linked to protein‐like DOM, but its transport was linked to humic‐like DOM.
Stereotactic body radiotherapy of adrenal metastases—A dose‐finding study
Authors: Buergy Daniel , Würschmidt Florian , Gkika Eleni , Hörner‐Rieber Juliane , Knippen Stefan , Gerum Sabine , Balermpas Panagiotis , Henkenberens Christoph , Voglhuber Theresa , Kornhuber Christine , Barczyk Steffen , Röper Barbara , Rashid Ali , Blanck Oliver , Wittig Andrea , Herold Hans‐Ulrich , Brunner Thomas Baptist , Sweeney Reinhart A. , Kahl Klaus Henning , Ciernik Ilja Frank , Ottinger Annette , Izaguirre Victor , Putz Florian , König Laila , Hoffmann Michael , Combs Stephanie Elisabeth , Guckenberger Matthias , Boda‐Heggemann Judit
Published: April 2022

Optimal doses for the treatment of adrenal metastases with stereotactic radiotherapy (SBRT) are unknown. We aimed to identify dose‐volume cut‐points associated with decreased local recurrence rates (LRR). A multicenter database of patients with adrenal metastases of any histology treated with SBRT (biologically effective dose, BED10 ≥50 Gy, ≤12 fractions) was analyzed. Details on dose‐volume parameters were required (planning target volume: PTV‐D98%, PTV‐D50%, PTV‐D2%; gross tumor volume: GTV‐D50%, GTV‐mean). Cut‐points for LRR were optimized using the R maxstat package. One hundred and ninety‐six patients with 218 lesions were included, the largest histopathological subgroup was adenocarcinoma (n = 101). Cut‐point optimization resulted in significant cut‐points for PTV‐D50% (BED10: 73.2 Gy; P = .003), GTV‐D50% (BED10: 74.2 Gy; P = .006), GTV‐mean (BED10: 73.0 Gy; P = .007), and PTV‐D2% (BED10: 78.0 Gy; P = .02) but not for the PTV‐D98% (P = .06). Differences in LRR were clinically relevant (LRR ≥ doubled for cut‐points that were not achieved). Further dose‐escalation was not associated with further improved LRR. PTV‐D50%, GTV‐D50%, and GTV‐mean cut‐points were also associated with significantly improved LRR in the adenocarcinoma subgroup. Separate dose optimizations indicated a lower cut‐point for the PTV‐D50% (BED10: 69.1 Gy) in adenocarcinoma lesions, other values were similar (<2% difference). Associations of cut‐points with overall survival (OS) and progression‐free survival were not significant but durable freedom from local recurrence was associated with OS in a landmark model (P < .001). To achieve a significant improvement of LRR for adrenal SBRT, a moderate escalation of PTV‐D50% BED10 >73.2 Gy (adenocarcinoma: 69.1 Gy) should be considered.
Amniotic growth factors enhanced human pre‐adipocyte cell viability and differentiation under hypoxia
Authors: Magana Alejandro , Giovanni Regina , Essien Edidiong , Epel Boris , Kotecha Mrignayani , Liu Songyun , Mathew Mathew T. , Hagarty Sarah E. , Bijukumar Divya
Published: April 2022

One of the major drawbacks associated with autologous fat grafting is unpredictable graft retention. Various efforts to improve the survivability of these cells have been explored, but these methods are time‐consuming, complex, and demand significant technical skill. In our study, we examine the use of cryopreserved amniotic membrane as a source of exogenous growth factors to improve adipocyte survivability under normal and hypoxic conditions. Human primary preadipocytes were cultured in a gelatin‐ferulic acid (Gtn‐FA) hydrogel with variable oxygen concentration and treated with amniotic membrane‐derived condition medium (CM) for 7 days. This hydrogel provides a hypoxic environment and also creates a 3D cell culture to better mimic recipient site conditions. The O2 concentration in the hydrogel was measured by electron paramagnetic resonance oxygen imaging (EPROI). The conjugation of FA was confirmed by FTIR and NMR spectroscopy. The cell viability and adipocyte differentiation were analyzed by alamarBlue™ assay, Oil Red O staining, and RT‐qPCR. The expression of genes: Pref‐1, C/EBP β, C/EBP α, PPAR‐ƴ, SLC2A4, and VEGF‐A were quantified. The cell viability results show that the 50% CM showed significantly higher cell pre‐adipocyte cell viability. In addition, compared to normal conditions, hypoxia/CM provided higher PPAR‐ƴ (p < .05), SLC2A4, and VEGF‐A (p < .05) (early and terminal differentiating markers) mRNA expression. This finding demonstrates the efficacy of amniotic CM supplementation as a novel way to promote adipocyte survival and retention via the expression of key gene markers for differentiation and angiogenesis.
Deletion of autophagy related, ATG1 and F‐box motif encoding YDR131C, together, lead to synthetic growth defects and flocculation behavior in Saccharomyces cerevisiae
Authors: Shoket Heena , Parvez Sadia , Sharma Meenu , Pandita Monika , Sharma Vishali , Kumar Prabhat , Bairwa Narendra K.
Published: April 2022

Ubiquitin proteasome system (UPS) and autophagy both pathways are involved in clearing the nonessential cellular components and also crosstalk during cellular response to normal and stress conditions. The F‐box motif proteins constitute the SCF‐E3 ligase complex of the UPS pathway in Saccharomyces cerevisiae and are involved in the substrate recruitment for ubiquitination. The ATG1 encoded Atg1p, a conserved serine‐threonine kinase is crucial for the autophagy process. Here in this study, we report that loss of F‐box motif encoding YDR131C and ATG1 together results in growth defects, floc formation, sensitivity to hydroxyurea, methyl methanesulfonate, and hydrogen peroxide. Both the genes also interact with the flocculation‐related genes (FLO) and associate with gene ontology terms “ubiquitin‐protein transferase activity” and “cellular catabolic process.” Based on in silico analysis and experimental evidence we conclude that YDR131C and ATG1 function in parallel pathways to regulate the growth, flocculation, and stress response.
L1CAM‐associated extracellular vesicles: A systematic review of nomenclature, sources, separation, and characterization
Authors: Gomes Dimitria E. , Witwer Kenneth W.
Published: April 2022

When released into biological fluids like blood or saliva, brain extracellular vesicles (EVs) might provide a window into otherwise inaccessible tissue, contributing useful biomarkers of neurodegenerative and other central nervous system (CNS) diseases. To enrich for brain EVs in the periphery, however, cell‐specific EV surface markers are needed. The protein that has been used most frequently to obtain EVs of putative neuronal origin is the transmembrane L1 cell adhesion molecule (L1CAM/CD171). In this systematic review, we examine the existing literature on L1CAM and EVs, including investigations of both neurodegenerative disease and cancer through the lens of the minimal information for studies of EVs (MISEV), specifically in the domains of nomenclature usage, EV sources, and EV separation and characterization. Although numerous studies have reported L1CAM‐associated biomarker signatures that correlate with disease, interpretation of these results is complicated since L1CAM expression is not restricted to neurons and is also upregulated during cancer progression. A recent study has suggested that L1CAM epitopes are present in biofluids mostly or entirely as cleaved, soluble protein. Our findings on practices and trends in L1CAM‐mediated EV separation, enrichment, and characterization yield insights that may assist with interpreting results, evaluating rigor, and suggesting avenues for further exploration.
Comparative effects of two humic substances on microbial dysbiosis in the rhizosphere soil where cucumber (Cucumis sativus L.) is grown
Authors: Jiang Nan , Wu Meng , Li Guilong , Li Pengfa , Liu Ming , Li Zhongpei
Published: April 2022

The extraction of humic substances from weathered coal and peat has been regarded as an effective way to utilize these wastes. However, the effects of humic acid (HA) and sodium humate (HN) (derived from weathered coal and peat, respectively) on soil microbial dysbiosis remain elusive. By virtue of Illumina sequencing and FUNGuild, we investigated the interrelationships between soil microbial communities and potential phytopathogenic fungi, found that merely HA surprisingly (p < 0.05) reduced the relative richness of potential phytopathogenic fungi in contrast to the controls. The relative abundances of potential pathogenic fungi, fungal community structures, network degrees, and the average degrees of potential pathogenic fungi were recognized as the crucial factors for the determination of cucumbers' aboveground biomasses via Random Forest classification. In addition, the aboveground biomasses were significantly (p < 0.05) and negatively related to the relative richness of potential pathogenic fungi. Among the 28 operational taxonomic units (OTU) that played the most important roles in determining the relative abundance of potential phytopathogenic fungi, 3 OTU belonging to the Penicillium and Nocardioides genera were significantly (p < 0.05) more abundant in the HA treatment. Therefore, it was obvious that HA facilitated the growth of beneficial microbes and increased the microbial network complexity, subsequently decreasing the relative abundance of phytopathogenic fungi and consequently increasing cucumbers' aboveground biomasses. The present research not only highlighted the differences between humic substances originating from weathered coal and peat but also indicated the significance of humic substances in regulating microbial communities, suppressing potential phytopathogenic fungi and facilitating cucumber growth.
No Effect of Isolated Anthocyanins from Bilberry Fruit and Black Rice on LDL Cholesterol or other Biomarkers of Cardiovascular Disease in Adults with Elevated Cholesterol: A Randomized, Placebo‐Controlled, Cross‐Over Trial
Authors: Aboufarrag Hassan , Hollands Wendy J. , Percival Jasmine , Philo Mark , Savva George M. , Kroon Paul A.
Published: April 2022

Scope

Some dietary interventions with berry fruits, berry fruit extracts, and purified anthocyanins have been reported to beneficially alter lipoprotein profiles in hyperlipidemic participants. The major anthocyanins in human diets are glycosides of cyanidin and delphinidin, and structure can influence both absorption and bioactivity. The aim of this study is to determine the effects of two major types of anthocyanins on low‐density lipoprotein cholesterol and other cardiometabolic markers for cardiovascular disease (CVD) risk in hyperlipidemic individuals.

Methods and results

Fifty‐two hyperlipidemic participants complete this randomized, placebo‐controlled, double‐blind, three arm crossover trial. Participants ingest capsules containing 320 mg of anthocyanins (bilberry trihydroxy‐type or black rice dihydroxy‐type) or placebo once daily for 28 days. Biomarkers of CVD risk are measured before and after the intervention period. Compared to the placebo, neither anthocyanin treatment significantly (p < 0.05) changes circulating levels of lipoproteins (total‐/high‐density lipoprotein (HDL)‐/low‐density lipoprotein (LDL)‐cholesterol, triglycerides, Apolipoprotein B (ApoB)), biomarkers of glycemic control (fasting glucose, fructosamine), biomarkers of HDL function (ApoA1, HDL3, paraoxonase‐1 (PON1) arylesterase, and lactonase activities), or plasma bile acids.

Conclusions

These data do not support the notion that regular consumption of anthocyanins beneficially affects glycemic control or lipoprotein profiles or functions. It is possible the no effect observation is due to the relatively short duration of treatments.
Experimental study on the durability of polymer‐impregnated basalt textile applied as concrete reinforcement
Authors: Zhang Xiaofei , Wang Xin , Liang Xunmei , Zhao Chunfeng , Wu Zhishen
Published: April 2022

This paper presents an experimental study on the durability of polymer‐impregnated basalt textile considering the effects of impregnation material, corrosion temperature, and corrosion solution. The variations in tensile strength, elastic modulus, surface condition, and failure mode were examined. Furthermore, a prediction model for the tensile strength degradation of basalt textiles was proposed. The experimental results showed that the tensile strength degradation of the textile was significantly influenced by the impregnation materials. The epoxy resin/acrylic emulsion‐impregnated textiles had superior durability to the styrene‐butadiene latex/vinyl resin‐impregnated textiles. As the temperature increased, the tensile strength decreased, whereas the variation in the elastic modulus was insignificant. In addition, the tensile strength of the weft textile degraded slightly faster than that of the warp textile owing to the larger contact area with the corrosion solution for the former. The saline–alkaline solution was more aggressive than the alkaline solution for the impregnated textiles owing to the corrosion caused by the combination of alkaline hydroxide ions and salt chloride ions in the former. The proposed model to predict the strength degradation considering both the aging time and temperature effect is in good agreement with the experimental results, which can be used to predict the long‐term strength of basalt textiles used as concrete reinforcement in real engineering applications.
Identifying the helpfulness of school climate: Skipping school, cheating on tests, and elements of school climate
Authors: Kupchik Aaron , Highberger James , Bear George
Published: April 2022

Prior research demonstrates the importance of school climate in shaping student behavior but tells us less about which aspects of school climate matter. In this paper we consider how distinct elements of school climate relate to skipping school and cheating on tests. Using survey and administrative data from several statewide Delaware sources, we perform a series of random‐intercept logistic regression models. We find that students in schools perceived to have a climate with high levels of structure and support are less likely to report cheating on tests. Yet we do not find a robust relationship between most climate measures and skipping school. School climate relates strongly to in‐school deviant behavior but much less to school‐related deviant behavior occurring outside of schools. By specifying what measures of climate do and do not relate to problematic student behaviors, our results sharpen our understandings of how school climate shapes student behaviors.
Mediating effect of resilience in the relationship between loneliness and life satisfaction during COVID‐19: A cross‐country study of Thai and Chinese college students
Authors: Tu Chia‐Ching , Yang Dong , Pan Lei , Dai Xiao
Published: April 2022

This study investigated the compensating mediating mechanism of resilience in the relationship between loneliness and life satisfaction in Thai and Chinese college students during a risk period of coronavirus disease 2019 transmission. A total of 262 Thai and 247 Chinese college students were enrolled in the study between December 2020 and January 2021. A measurement model was constructed with the items of loneliness, resilience, and life satisfaction by using structural equation models. Subsequently, structural mediating models were constructed according to the valid items and a multigroup comparison was performed. The relationship between loneliness and life satisfaction differed significantly between Thai and Chinese college students as a result of the mediating effect of resilience. Resilience in Thai college students partly compensated for the negative influence of loneliness on life satisfaction, and resilience in Chinese college students compensated completely for the negative influence of loneliness on life satisfaction.
Delta‐Doped β‐(Al0.17Ga0.83)2O3/Ga2O3 Double‐Channel Heterostructure MODFETs
Authors: Atmaca Gökhan , Cha Ho-Young
Published: April 2022

Herein, in delta‐doped β‐(AlxGa1–x)2O3/β‐Ga2O3 heterostructures, the 2D electron gas (2DEG) density is mainly limited by the low conduction‐band offset at the heterointerface. Double‐channel heterostructures may be a candidate solution for enhancing the 2DEG density in these heterostructures. In this study, the output characteristics, transfer, transconductance, and off‐state current characteristics of delta‐doped β‐(Al0.17Ga0.83)2O3/β‐Ga2O3 double‐channel heterostructure modulation‐doped field‐effect transistors (MODFETs), including the effects of an ultrathin spacer layer and a back‐barrier layer, are numerically evaluated. The electrical characteristics of the proposed double‐channel heterostructure MODFET are compared with those of a single‐channel heterostructure MODFET. The proposed double‐channel heterostructure MODFET shows a maximum drain current of 133.7 mA mm−1 and a g
m peak of 40 mS mm−1, which are higher than those in the single‐channel case. The calculated threshold voltage is −3.45 V. The dependence of the Si δ‐doping density in the second barrier and channel layer thickness on the electrical characteristics of the proposed device is evaluated and discussed. A β‐(Al0.17Ga0.83)2O3/β‐Ga2O3 superlattice back‐barrier structure is also implemented in delta‐doped β‐Ga2O3‐based heterostructure MODFETs to improve their off‐state characteristics for the first time.
Theoretical Methods for Excitonic Physics in 2D Materials
Authors: Quintela Maurício F. C. Martins , Henriques João C. G. , Tenório Luiz G. M. , Peres Nuno M. R.
Published: April 2022

In this Perspective article, the reader is introduced to several theoretical methods of determining the exciton wave functions and the corresponding eigenenergies. The methods covered are either analytical, semianalytical, or numeric. All the details associated with the different methods are made explicit, thus allowing newcomers to do research on their own, without experiencing a steep learning curve. The Perspective starts with a variational method and ends with a simple semianalytical approach to solve the Bethe–Salpeter equation (BSE) in gapped 2D materials. For the first methods addressed in this Perspective, the authors focus on a single layer of hexagonal boron nitride (hBN) and of transition metal dichalcogenide (TMD), as these are exemplary materials in the field of 2D excitons. For explaining the Bethe–Salpeter method, the biased bilayer graphene, which presents a tunable bandgap is chosen. The system has the right amount of complexity (without being excessive). This allows the presentation of the solution in a context that can be easily generalized to more complex systems or to apply it to simpler models.
Mentoring across differences in science education: Applying a brokering framework
Authors: Haverly Christa , Brown Bryan A.
Published: April 2022

Mentoring relationships in academia have traditionally been described as a dyad between a mentor and a mentee. The mentor provides the mentee with both technical and psychosocial support to move toward obtaining their Ph.D. or gaining tenure and promotion. While there is an embedded assumption that mentoring is best suited when people of common background support each other, scholars must consider the impact of mentoring across differences. Given the lack of diversity among senior faculty members in science education, and given the increasing diversity represented among graduate students and early career scholars in science education, inevitably mentoring relationships will be formed across differences in identities (race, ethnicity, gender, sexuality, ability). In our essay, we focus on two focal points: we explore those aspects of mentoring relationships that research suggests are critical to the success of relationships built across differences, foregrounding lessons science education researchers can take from this literature and arguing that it is too much to expect one individual mentor to provide to any given mentee. Next, we propose a brokering framework, leveraging technological advances, to work toward more transformative mentoring outcomes at scale, particularly when mentoring across differences.
Effect of Microstructural Evolution on the Mechanical Properties of Intercritical Heat‐Affected Zone of Quenched‐and‐Tempered Ultrahigh‐Strength Steel
Authors: Zhang Xingping , Di Xinjie , Jing Wen , Zhou Xiaofeng , Zhang Chuanyou , Li Chengning
Published: April 2022

In order to investigate the effect of microstructural evolution on the mechanical properties in the intercritical heat‐affected zone (ICHAZ) of the quenched‐and‐tempered ultrahigh‐strength steel, the simulated ICHAZ samples with different austenite transformation degrees (0%, 25%, 50%, 75%, and 100%) are prepared. These samples are named IC‐0%, IC‐25%, IC‐50%, IC‐75%, and IC‐100%, respectively. The fine‐grained fresh martensite (FM) is produced in the partial austenite transformation during cooling. The austenite in IC‐100% with the lowest C and Mn content is transformed into a mixture of FM and granular bainite (GB). The IC‐0% and the IC‐25% are softened by about 20 HV10 compared with that of the base metal. When the matrix is transformed into quasi‐polygonal ferrite (QPF), the large difference in microhardness between FM and QPF causes the instability of their interfaces, resulting in the deterioration of the impact toughness in IC‐50% and IC‐75%. However, from IC‐75% to IC‐100%, the impact toughness has been improved from 18.0 to 28.9 J. In addition to the less embrittlement of microstructure in IC‐100%, the lower microhardness difference between FM and GB is the main reason.
Lectotypification of the Linnaean plant name Durio zibethinus (Malvaceae), based on Rumphius's illustration
Authors: Ganesan S.K. , Neo Louise
Published: April 2022

The typification of the name of an iconic Southeast Asian fruit, Durio zibethinus, is discussed. Based on consultation of Linnaeus's original material, an illustration from Rumphius's Herbarium Amboinense is designated as the lectotype.
Autonomy in the Digital Wilds: Agency, Competence, and Self‐efficacy in the Development ofL2Digital Identities
Authors: Han Yiting , Reinhardt Jonathon
Published: April 2022

The termdigital wildshas come to refer to the non‐formal online spaces in and through which additional language (L2) learner‐users, using a multifarious array of tools, platforms, and services, autonomously navigate personal learning trajectories (Sauro & Zourou, 2019), developing L2 digital literacies‐mediated identities needed in life‐wide settings. This article examined how three successful, autonomous English L2 learner‐users critically and creatively engaged in L2 digital literacy practices, ranging from navigating social media and the Internet to ‘reprodusing’ (Reinhardt & Thorne, 2019) content on video‐sharing sites. This article focuses on (1) the development of digital learner autonomy in successful English L2 learners and (2) the entanglement of L2 digital literacy practices, identities, and livelihoods. The analysis shows that agency, competence, and self‐efficacy played key roles in autonomy development, which was inextricably intertwined with emergent identities and realized through the practice of digital literacies. The findings shed light on the potential role of language educators in leveraging activity in the digital wilds for formal learning purposes.
Dynamics of Complex Singularities of Nonlinear PDEs
Authors: Weideman J. A. C.
Published: April 2022

Solutions to nonlinear evolution equations exhibit a wide range of interesting phenomena such as shocks, solitons, recurrence, and blow-up. As an aid to understanding some of these features, the solutions can be viewed as analytic functions of a complex space variable. The dynamics of poles and branch point singularities in the complex plane can often be associated with the aforementioned features of the solution. Some of the computational and analytical results in this area are surveyed here. This includes a first attempt at computing the poles in the famous Zabusky–Kruskal experiment that lead to the discovery of the soliton.
Commercially Sustainable Cassava Seed Systems in Africa
Authors: Legg James P. , Diebiru-Ojo Elohor , Eagle David , Friedmann Michael , Kanju Edward , Kapinga Regina , Kumar P. Lava , Lateef Sanni , Magige Stephen , Mtunda Kiddo , Thiele Graham , Yabeja Juma , Nitturkar Hemant
Published: April 2022

Cassava is an important crop in sub-Saharan Africa for food security, income generation, and industrial development. Business-oriented production systems require reliable supplies of high-quality seed. Major initiatives in Nigeria and Tanzania have sought to establish sustainable cassava seed systems. These include the deployment of new technologies for early generation seed (EGS) production; the promotion of new high-yielding and disease-resistant varieties; the updating of government seed policy to facilitate enabling certification guidelines; the application of ICT tools, Seed Tracker and Nuru AI, to simplify seed system management; and the establishment of networks of cassava seed entrepreneurs (CSEs). CSEs have been able to make profits in both Nigeria (US$ 551–988/ha) and Tanzania (US$ 1,000 1,500/ha). In Nigeria, the critical demand driver for cassava seed businesses is the provision of new varieties. Contrastingly, in Tanzania, high incidences of cassava brown streak disease mean that there is a strong demand for the provision of healthy seed that has been certified by regulators. These models for sustainable cassava seed system development offer great promise for scaling to other cassava-producing countries in Africa where there is strong government support for the commercialization of the cassava sector.
Monitoring Network Flows in Containerized Environments
Authors: Repetto Matteo , Carrega Alessandro
Published: April 2022

With the progressive implementation of digital services over virtualized infrastructures and smart devices, the inspection of network traffic becomes more challenging than ever, because of the difficulty to run legacy cybersecurity tools in novel cloud models and computing paradigms. The main issues concern i) the portability of the service across heterogeneous public and private infrastructures, that usually lack hardware and software acceleration for efficient packet processing, and ii) the difficulty to integrate monolithic appliances in modular and agile containerized environments.

In this Chapter, we investigate the usage of the extended Berkeley Packet Filter (eBPF) for effective and efficient packet inspection in virtualized environments. Our preliminary implementation demonstrates that we can achieve the same performance as well-known packet inspection tools, but with far less resource consumption. This motivates further research work to extend the capability of our framework and to integrate it in Kubernetes.
Detecting Unknown Cyber Security Attacks Through System Behavior Analysis
Authors: Skopik Florian , Wurzenberger Markus , Landauer Max
Published: April 2022

For many years signature-based intrusion detection has been applied to discover known malware and attack vectors. However, with the advent of malware toolboxes, obfuscation techniques and the rapid discovery of new vulnerabilities, novel approaches for intrusion detection are required. System behavior analysis is a cornerstone to recognizing adversarial actions on endpoints in computer networks that are not known in advance. Logs are incrementally produced textual data that reflect events and their impact on technical systems. Their efficient analysis is key for operational cyber security. We investigate approaches beyond applying simple regular expressions, and provide insights into novel machine learning mechanisms for parsing and analyzing log data for online anomaly detection. The AMiner is an open source implementation of a pipeline that implements many machine learning algorithms that are feasible for deeper analysis of system behavior, recognizing deviations from learned models and thus spotting a wide variety of even unknown attacks.
Rebooting quarter-BPS operators in $$ \mathcal{N} $$ = 4 super Yang-Mills
Authors: Bissi Agnese , Fardelli Giulia , Manenti Andrea
Published: April 2022

Abstract

We start a systematic study of quarter-BPS operators in four-dimensional $$ \mathcal{N} $$
N
= 4 Super Yang-Mills with gauge group SU(N) making use of recently developed tools in conformal field theory. We adapt the technology of embedding space tensor structures in four dimensions to the problem of computing R-symmetry tensor structures, and we use the underlying chiral algebra to obtain the superconformal Ward identities. This allows us to fix the protected part of the four-point correlators, up to few ambiguities. As applications, we use the Lorentzian inversion formula to study the leading order OPE data in the large N supergravity limit and we make contact with the OPE limit of the five-point function of half-BPS operators.
Constraints on dark matter annihilation from the Event Horizon Telescope observations of M87*
Authors: Yuan Guan-Wen , Chen Zhan-Fang , Shen Zhao-Qiang , Guo Wen-Qing , Ding Ran , Huang Xiaoyuan , Yuan Qiang
Published: April 2022

Abstract

The fast developments of radio astronomy open a new window to explore the properties of Dark Matter (DM). The recent direct imaging of the supermassive black hole (SMBH) at the center of M87 radio galaxy by the Event Horizon Telescope (EHT) collaboration is expected to be very useful to search for possible new physics. In this work, we illustrate that such results can be used to detect the possible synchrotron radiation signature produced by DM annihilation from the innermost region of the SMBH. Assuming the existence of a spike DM density profile, we obtain the flux density due to DM annihilation induced electrons and positrons, and derive new limits on the DM annihilation cross section via the comparison with the EHT integral flux density at 230 GHz. Our results show that the parameter space can be probed by the EHT observations is largely complementary to other experiments. For DM with typical mass regions of being weakly interacting massive particles, the annihilation cross section several orders of magnitude below the thermal production level can be excluded by the EHT observations under the density spike assumption. Future EHT observations may further improve the sensitivity on the DM searches, and may also provide a unique opportunity to test the interplay between DM and the SMBH.
The large N limit of icMERA and holography
Authors: Fernández-Melgarejo José J. , Molina-Vilaplana Javier
Published: April 2022

Abstract

In this work, we compute the entanglement entropy in continuous icMERA tensor networks for large N models at strong coupling. Our results show that the 1/N quantum corrections to the Fisher information metric (interpreted as a local bond dimension of the tensor network) in an icMERA circuit, are related to quantum corrections to the minimal area surface in the Ryu-Takayanagi formula. Upon picking two different non-Gaussian entanglers to build the icMERA circuit, the results for the entanglement entropy only differ at subleading orders in 1/GN, i.e., at the structure of the quantum corrections in the bulk. The fact that the large N part of the entropy can be always related to the leading area term of the holographic calculation is very suggestive. These results, constitute the first tensor network calculations at large N and strong coupling simultaneously, pushing the field of tensor network descriptions of the emergence of dual spacetime geometries from the structure of entanglement in quantum field theory.
Beruflich erworbene SARS-CoV-2-Infektionen bei medizinischem Personal in Frankfurt am Main von März bis August 2020
Authors: Sundberg Anton , Gottschalk René , Wicker Sabine
Published: April 2022

Hintergrund

Eine standardisierte Erhebung von COVID-19-Infektionen bei Gesundheitspersonal während der laufenden Pandemie war und ist nicht gegeben. Vor allem der Anteil von arbeitsbedingten Infektionen beim Gesundheitspersonal und die Frage, welche Arbeitnehmer/-innen darunter am meisten gefährdet sind, bleiben unklar.

Ziel

Ziel dieser Studie war es, die gemeldeten COVID-19-Fälle beim Gesundheitspersonal in Frankfurt/Main in den ersten 6 Monaten der Pandemie zu analysieren, die Zahl der arbeitsbedingten Infektionen zu ermitteln und somit eine bessere Interpretation der durch das Robert Koch-Institut veröffentlichten Daten zu ermöglichen.

Methoden

Die Daten des Gesundheitsamts Frankfurt/Main wurden für den Zeitraum vom 01.03. bis zum 31.08.2020 betrachtet und medizinisches Personal für eine Querschnittserhebung im Rahmen einer Umfrage rekrutiert. Drei Subgruppen wurden nach Ort des Infektionskontakts, am Arbeitsplatz, im Privaten und unbekannt, unterteilt und analysiert.

Ergebnisse

Medizinisches Personal machte 11,8 % (319/2700) aller gemeldeten COVID-19-Fälle in Frankfurt/Main im untersuchten Zeitraum aus. In der Umfrage gaben 47,2 % der Befragten an, dass ihre Infektion am Arbeitsplatz erworben wurde. Es zeigte sich eine Assoziation von Kontakt zu COVID-19-Patient/-innen sowie der Beschäftigung auf einer internistischen Station und einer arbeitsbedingten Infektion. Ersichtlich wurde außerdem ein Zusammenhang zwischen mutmaßlichen Infektionen am Arbeitsplatz und folglich gestellten Verdachtsanzeigen auf Berufskrankheit.

Diskussion und Fazit

Gesundheitsämter sind in der Lage, relevante Daten von arbeitsbedingten Transmissionen in Berufen und Arbeitsplätzen im Gesundheitswesen zu erheben, und sollten standardisierte Daten zu infiziertem Gesundheitspersonal generieren. Diese Daten sind notwendig, um gezielte Maßnahmen der Infektionsprävention zu ergreifen, die Gesundheitspersonal und ihre Patient/-innen schützen.
Clinical perspectives on the age-related increase of immunosuppressive activity
Authors: Salminen Antero
Published: April 2022

The aging process is associated with a remodeling of the immune system involving chronic low-grade inflammation and a gradual decline in the function of the immune system. These processes are also called inflammaging and immunosenescence. The age-related immune remodeling is associated with many clinical changes, e.g., risk for cancers and chronic infections increases, whereas the efficiency of vaccination and immunotherapy declines with aging. On the other hand, there is convincing evidence that chronic inflammatory states promote the premature aging process. The inflammation associated with aging or chronic inflammatory conditions stimulates a counteracting immunosuppression which protects tissues from excessive inflammatory injuries but promotes immunosenescence. Immunosuppression is a driving force in tumors and chronic infections and it also induces the tolerance to vaccination and immunotherapies. Immunosuppressive cells, e.g., myeloid-derived suppressor cells (MDSC), regulatory T cells (Treg), and type M2 macrophages, have a crucial role in tumorigenesis and chronic infections as well as in the tolerance to vaccination and immunotherapies. Interestingly, there is substantial evidence that inflammaging is also associated with an increased immunosuppressive activity, e.g., upregulation of immunosuppressive cells and anti-inflammatory cytokines. Given that both the aging and chronic inflammatory states involve the activation of immunosuppression and immunosenescence, this might explain why aging is a risk factor for tumorigenesis and chronic inflammatory states and conversely, chronic inflammatory insults promote the premature aging process in humans.
Long-term outcomes of image-guided ablation and laparoscopic partial nephrectomy for T1 renal cell carcinoma
Authors: Chan Vinson Wai-Shun , Osman Filzah Hanis , Cartledge Jon , Gregory Walter , Kimuli Michael , Vasudev Naveen S. , Ralph Christy , Jagdev Satinder , Bhattarai Selina , Smith Jonathan , Lenton James , Wah Tze Min
Published: April 2022

Objective

To compare long-term outcomes and peri-operative outcomes of image-guided ablation (IGA) and laparoscopic partial nephrectomy (LPN).

Material and methods

This is a retrospective cohort study of localised RCC (T1a/bN0M0) patients undergoing cryoablation (CRYO), radio-frequency ablation (RFA), or LPN at our institution from 2003 to 2016. Oncological outcomes were compared using Cox regression and log-rank analysis. eGFR changes were compared using Kruskal-Wallis and Wilcoxon-rank tests.

Results

A total of 296 (238 T1a, 58 T1b) consecutive patients were identified; 103, 100, and 93 patients underwent CRYO, RFA, and LPN, respectively. Median follow-up time was 75, 98, and 71 months, respectively. On univariate analysis, all oncological outcomes were comparable amongst CRYO, RFA, and LPN (p > 0.05). On multivariate analysis, T1a patients undergoing RFA had improved local recurrence-free survival (LRFS) (HR 0.002, 95% CI 0.00–0.11, p = 0.003) and metastasis-free survival (HR 0.002, 95% CI 0.00–0.52, p = 0.029) compared to LPN. In T1a and T1b patients combined, both CRYO (HR 0.07, 95% CI 0.01–0.73, p = 0.026) and RFA (HR 0.04, 95% CI 0.03–0.48, p = 0.011) had improved LRFS rates. Patients undergoing CRYO and RFA had a significantly smaller median decrease in eGFR post-operatively compared to LPN (T1a: p < 0.001; T1b: p = 0.047). Limitations include retrospective design and limited statistical power.

Conclusions

IGA is potentially as good as LPN in oncological durability. IGA preserves kidney function significantly better than LPN. More studies with larger sample size should be performed to establish IGA as a first-line treatment alongside LPN.

Key Points

• Ablative therapies are alternatives to partial nephrectomy for managing small renal cell carcinomas.

• This study reports long-term outcomes of image-guided ablation versus partial nephrectomy.

• Ablative therapies have comparable oncological durability and better renal function preservation compared to partial nephrectomy.
Lack of evidence for the oxidative stress theory of bleaching in the sea anemone, Exaiptasia diaphana, under elevated temperature
Authors: Dungan Ashley M. , Maire Justin , Perez-Gonzalez Alexis , Blackall Linda L. , van Oppen Madeleine J. H.
Published: April 2022

To survive in nutrient-poor waters corals rely on a symbiotic association with intracellular microalgae. However, increased sea temperatures cause algal loss—known as coral bleaching—often followed by coral death. Some of the most compelling evidence in support of the ‘oxidative stress theory of coral bleaching’ comes from studies that exposed corals, cultures of their algal endosymbionts, or the coral modelExaiptasia diaphanato exogenous antioxidants during thermal stress. Here, we replicate these experiments usingE.diaphanawith the addition of the antioxidants ascorbate + catalase, catechin, or mannitol under ambient and elevated temperatures along with an antioxidant-free control. In the absence of exogenous antioxidants,E.diaphanaexposed to elevated temperatures bleached with no change in reactive oxygen species (ROS) levels associated with their microalgal cells. Ascorbate + catalase and mannitol treatments rescued the anemones from bleaching, although microalgal ROS levels increased in these antioxidant treatments under elevated temperature conditions. While bleaching was not associated with changes in net ROS for the intracellular algal symbionts, it is evident from our findings that excess ROS is connected to the bleaching phenotype as exogenous antioxidants were successful in mitigating the effects of thermal stress in cnidarians. This understanding may assist applied research that aims to reduce the impact of climate change on coral reefs.