bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating the Effects of Inertia and Frequency Response Services on Transient Propagation in a Networked Grid
Authors: Cooke A. Christian , Mestel B. Benjamin
Published: August 2023

As part of climate change mitigation efforts, there has been acceleration in the deployment of distributed renewable generation replacing conventional thermal power plants in grids across the world. As a result, there has been a change in the aggregate and regional inertial capacity, with consequences for the stability of these networks and their ability to withstand large variations in frequency. Building on previous work that successfully simulated frequency events on the GB grid using a single bus model, this paper describes a networked grid model using an algebraic differential system of equations. This is used to simulate the effects of localized variation in inertia and frequency response services on the propagation of transients across a network. Using this model, the effects of varying responses to transients can be investigated, and grids of varying scales and topologies can be compared to determine differences in their response to outages. The propagation of disturbances across domains within the network that have different frequency response characteristics can be examined with a view to drawing conclusions about the optimal deployment of frequency response services, and their relative cost-effectiveness in delivering a stable supply as the proportion of renewable generation in the energy mix grows.
Cross-lingual extreme summarization of scholarly documents
Authors: Takeshita Sotaro , Green Tommaso , Friedrich Niklas , Eckert Kai , Ponzetto Simone Paolo
Published: August 2023

The number of scientific publications nowadays is rapidly increasing, causing information overload for researchers and making it hard for scholars to keep up to date with current trends and lines of work. Recent work has tried to address this problem by developing methods for automated summarization in the scholarly domain, but concentrated so far only on monolingual settings, primarily English. In this paper, we consequently explore how state-of-the-art neural abstract summarization models based on a multilingual encoder–decoder architecture can be used to enable cross-lingual extreme summaries of scholarly texts. To this end, we compile a new abstractive cross-lingual summarization dataset for the scholarly domain in four different languages, which enables us to train and evaluate models that process English papers and generate summaries in German, Italian, Chinese and Japanese. We present our new X-SCITLDR dataset for multilingual summarization and thoroughly benchmark different models based on a state-of-the-art multilingual pre-trained model, including a two-stage pipeline approach that independently summarizes and translates, as well as a direct cross-lingual model. We additionally explore the benefits of intermediate-stage training using English monolingual summarization and machine translation as intermediate tasks and analyze performance in zero- and few-shot scenarios. Finally, we investigate how to make our approach more efficient on the basis of knowledge distillation methods, which make it possible to shrink the size of our models, so as to reduce the computational complexity of the summarization inference.
Facial Mimicry and Social Context Affect Smile Interpretation
Authors: Orlowska Anna , Rychlowska Magdalena , Szarota Piotr , Krumhuber Eva G.
Published: August 2023

Theoretical accounts and extant research suggest that people use various sources of information, including sensorimotor simulation and social context, while judging emotional displays. However, the evidence on how those factors can interplay is limited. The present research tested whether social context information has a greater impact on perceivers’ smile judgments when mimicry is experimentally restricted. In Study 1, participants watched images of affiliative smiles presented with verbal descriptions of situations associated with happiness or politeness. Half the participants could freely move their faces while rating the extent to which the smiles communicated affiliation, whereas for the other half mimicry was restricted via a pen-in-mouth procedure. As predicted, smiles were perceived as more affiliative when the social context was polite than when it was happy. Importantly, the effect of context information was significantly larger among participants who could not freely mimic the facial expressions. In Study 2 we replicated this finding using a different set of stimuli, manipulating context in a within-subjects design, and controlling for empathy and mood. Together, the findings demonstrate that mimicry importantly modulates the impact of social context information on smile perception.
Carbon in Solution and the Charpy Impact Performance of Medium Mn Steels
Authors: Kwok T. W. J. , Worsnop F. F. , Douglas J. O. , Dye D.
Published: August 2023

Carbon is a well known austenite stabiliser and can be used to alter the stacking fault energy and stability against martensitic transformation in medium Mn steels, producing a range of deformation mechanisms such as the Transformation Induced Plasticity (TRIP) or combined Twinning and Transformation Induced Plasticity (TWIP + TRIP) effects. However, the effect of C beyond quasi-static tensile behaviour is less well known. Therefore, two medium Mn steels with 0.2 and 0.5 wt pct C were designed to produce similar austenite fractions and stability and therefore tensile behaviour. These were processed to form lamellar and mixed equiaxed + lamellar microstructures. The low C steel had a corrected Charpy impact energy (KV$$_{10}$$

10

) of 320 J cm$$^{-2}$$

-
2

compared to 66 J cm$$^{-2}$$

-
2

in the high C steel despite both having a ductility of over 35 pct. Interface segregation, e.g., of tramp elements, was investigated as a potential cause and none was found. Only a small amount of Mn rejection from partitioning was observed at the interface. The fracture surfaces were investigated and the TRIP effect was found to occur more readily in the Low C Charpy specimen. Therefore it is concluded that the use of C to promote TWIP + TRIP behaviour should be avoided in alloy design but the Charpy impact performance can be understood purely in terms of C in solution.
Lakatosian and Euclidean populations: a pluralist approach to conceptual change in mathematics
Authors: De Benedetto Matteo
Published: August 2023

Lakatos’ (Lakatos, 1976) model of mathematical conceptual change has been criticized for neglecting the diversity of dynamics exhibited by mathematical concepts. In this work, I will propose a pluralist approach to mathematical change that re-conceptualizes Lakatos’ model of proofs and refutations as an ideal dynamic that mathematical concepts can exhibit to different degrees with respect to multiple dimensions. Drawing inspiration from Godfrey-Smith’s (Godfrey-Smith, 2009) population-based Darwinism, my proposal will be structured around the notion of a conceptual population, the opposition between Lakatosian and Euclidean populations, and the spatial tools of the Lakatosian space. I will show how my approach is able to account for the variety of dynamics exhibited by mathematical concepts with the help of three case studies.
Righteous Politics
Authors: Kamrava Mehran
Published: August 2023

Since the establishment of the Islamic Republic of Iran in 1979, the Iranian political system has been subject to diminishing legitimacy. In recent years, various waves of protest have spread across the country and the question of the resilience of the revolutionary state becomes more pressing by the day. Drawing from extensive fieldwork and rare primary sources, Mehran Kamrava provides here a comprehensive and accessible analysis of the Iranian state and the various formal and informal institutions through which it operates. The book offers an in-depth analysis of the Iranian state, from the Constitution to the powers and offices of the Supreme Leader, the Islamic Revolutionary Guard Corps to the several intelligence agencies. Paying careful attention to the nuances of Iranian politics, Kamrava also highlights how factional politics and rentierism have served to enhance state resilience. Presenting a range of original insights, this book is invaluable to understanding the inner workings of the contemporary Iranian state.
Longevity risk and capital markets: the 2021–22 update
Authors: Blake David , Cairns Andrew J. G. , Kallestrup-Lamb Malene , Rangvid Jesper
Published: August 2023

This special issue of the Journal of Demographic Economics contains 10 contributions to the academic literature all dealing with longevity risk and capital markets. Draft versions of the papers were presented at Longevity 16: The Sixteenth International Longevity Risk and Capital Markets Solutions Conference that was held in Helsingør near Copenhagen on 13–14 August 2021. It was hosted by PerCent at Copenhagen Business School and the Pensions Institute at City, University of London.
Effect of the COVID-19 frailty heterogeneity on the future evolution of mortality by stratified weighting
Authors: Carannante Maria , D'Amato Valeria , Haberman Steven
Published: August 2023

The starting point of our research is the inadequacy of assuming, in the construction of a model of mortality, that frailty is constant for the individuals comprising a demographic population. This assumption is implicitly made by standard life table techniques. The substantial differences in the individual susceptibility to specific causes of death lead to heterogeneity in frailty, and this can have a material effect on mortality models and projections—specifically a bias due to the underestimation of longevity improvements. Given these considerations, in order to overcome the misrepresentation of the future mortality evolution, we develop a stochastic model based on a stratification weighting mechanism, which takes into account heterogeneity in frailty. Furthermore, the stratified stochastic model has been adapted also to capture COVID-19 frailty heterogeneity, that is a frailty worsening due to the COVID-19 virus. Based on different frailty levels characterizing a population, which affect mortality differentials, the analysis allows for forecasting the temporary excess of deaths by the stratification schemes in a stochastic environment.
Ulrich modules and weakly lim Ulrich sequences do not always exist
Authors: Yhee Farrah C.
Published: August 2023

The existence of Ulrich modules for (complete) local domains has been a difficult and elusive open question. For over thirty years, it was unknown whether complete local domains always have Ulrich modules. In this paper, we answer the question of existence for both Ulrich modules and weakly lim Ulrich sequences – a weaker notion recently introduced by Ma – in the negative. We construct many local domains in all dimensions

$d \geq 2$

that do not have any Ulrich modules. Moreover, we show that when

$d = 2$

, these local domains do not have weakly lim Ulrich sequences.
Beyond Linguistic Peripheral Elites: The Provincial Imbalance of Cabinet Ministers in Belgium
Authors: Dandoy Régis
Published: August 2023

Despite the creation of regions and communities in the second half of the 20th century for resolving ethnic tensions between the French- and Flemish-speaking communities, provinces are still relevant to understand contemporary Belgian politics. Observing provincial political dynamics is essential to understand multi-level political elite dynamics and territorial cleavages in contemporary Belgium. For instance, political parties are internally structured in provincial federations, and federal elections rely on provincial electoral districts. Combined with constitutional factors such as language and region, this article investigates the provincial origins of ministerial elites in all Belgian federal cabinets between 1980 and 2020. It observes that provinces are far from being perfectly present in a balanced manner in the federal government: some provinces are overrepresented while others – in particular large provinces – are underrepresented. This provincial imbalance is stable over time and independent on the types of cabinet but can be explained by party strategies and vote-seeking considerations.
Decolonizing African and African Diasporan Cultural Memory in Djanet Sears and M. NourbeSe Philip’s Works
Authors: Cuder-Domínguez Pilar
Published: August 2023

This article proposes to look back onto the Black Canadian works produced around the turn of the twenty-first century to establish some of the decolonial practices they promoted, arguing that they remain pivotal in decentering the colonial gaze that to this day is at the root of anti-Black hatred. In the face of continued structural violence and anti-Black racism preeminent across Canada to date, it attempts to unpack the purpose and means deployed in their early texts by two pioneer Black Canadian women writers, Djanet Sears and M. NourbeSe Philip, to decolonize African cultural memory from the diaspora by teaching us to value African legacies outside of Eurocentric standards. Drawing from feminist anthropologist Rita Segato, it contends that these texts perform a “counter-pedagogy of cruelty,” that is, an act of resistance to all those sociocultural practices by which people are taught, trained, and hardened to the ongoing commodification of others.
On the structure of lower bounded HNN extensions
Authors: Bennett Paul , Jajcayová Tatiana B.
Published: August 2023

This paper studies the structure and preservational properties of lower bounded HNN extensions of inverse semigroups, as introduced by Jajcayová. We show that if
$S^* = [ S;\; U_1,U_2;\; \phi ]$
is a lower bounded HNN extension then the maximal subgroups of
$S^*$
may be described using Bass-Serre theory, as the fundamental groups of certain graphs of groups defined from the
$\mathcal{D}$
-classes of
$S$
,
$U_1$
and
$U_2$
. We then obtain a number of results concerning when inverse semigroup properties are preserved under the HNN extension construction. The properties considered are completely semisimpleness, having finite
$\mathcal{R}$
-classes, residual finiteness, being
$E$
-unitary, and
$0$
-
$E$
-unitary. Examples are given, such as an HNN extension of a polycylic inverse monoid.
Echocardiographic findings in non-hospitalised children and adolescents following acute COVID-19
Authors: McIntosh Amanda M. , Goyal Anmol , Moser-Dungan Carol , Harvey Brian , Heching Howard J. , Aly Doaa G. , Madan Nitin , Forsha Daniel
Published: August 2023

Background:

Although COVID-19 is known to have cardiac effects in children, seen primarily in severe disease, more information is needed about the cardiac effects following COVID-19 in non-hospitalised children and adolescents during recovery. This study aims to compare echocardiographic markers of cardiac size and function of children following acute COVID-19 with those of healthy controls.

Methods:

This single-centre retrospective case–control study compared 71 cases seen in cardiology clinic following acute COVID-19 with 33 healthy controls. Apical left ventricle, apical right ventricle, and parasternal short axis at the level of the papillary muscles were analysed to measure ventricular size and systolic function. Strain was analysed on vendor-independent software. Statistical analysis was performed using t-test, chi-square, Wilcoxon rank sum, and regression modelling as appropriate (p < 0.05 significant).

Results:

Compared to controls, COVID-19 cases had slightly higher left ventricular volumes and lower left ventricular ejection fraction and right ventricular fractional area change that remained within normal range. There were no differences in right or left ventricular longitudinal strain between the two groups. Neither initial severity nor persistence of symptoms after diagnosis predicted these differences.

Conclusions:

Echocardiographic findings in children and adolescents 6 weeks to 3 months following acute COVID-19 not requiring hospitalisation were overall reassuring. Compared to healthy controls, the COVID-19 group demonstrated mildly larger left ventricular size and lower conventional measures of biventricular systolic function that remained within the normal range, with no differences in biventricular longitudinal strain. Future studies focusing on longitudinal echocardiographic assessment of patients following acute COVID-19 are needed to better understand these subtle differences in ventricular size and function.
Divided Images: How the English Perceive Nationhood and How This Shapes Voting and Opinion
Authors: Kaufmann Eric , Leal David L. , Tafoya Joe R.
Published: August 2023

Do people’s political beliefs alter the emphasis they place on different symbols when constructing their “personal” national identity (Cohen 1996)? Does the content of their national identity affect how they vote? These are the central questions we address in this article, focusing on England but using the United States as a comparative case to demonstrate common dynamics.
Characteristics of the obesogenic environment around schools are associated with body fat and low-grade inflammation in Brazilian children
Authors: Filgueiras Mariana De Santis , Pessoa Milene Cristine , Bressan Josefina , Fogal Vegi Aline Siqueira , do Carmo Ariene Silva , Albuquerque Fernanda Martins de , Gardone Danielle Soares , Novaes Juliana Farias de
Published: August 2023

Objective:

To assess the association of obesogenic environmental characteristics around schools with body adiposity and adipokine concentrations in Brazilian children.

Design:

Cross-sectional study. Body adiposity was assessed using the dual-energy X-ray absorptiometry. Concentrations of leptin, adiponectin, retinol-binding protein 4 (RBP4) and chemerin were measured. Predominantly ultra-processed food (UPF) stores, public physical activity (PA) facilities, green spaces, walkability, traffic accidents and crime were evaluated. The neighbourhood unit was the 400 m (0·25 miles) road network buffer around schools. The association of environmental characteristics with body adiposity and adipokine concentrations was assessed by linear regression models using generalised estimating equations.

Setting:

Urban schools (n 24), Viçosa, Minas Gerais, Brazil.

Participants:

Children aged 8 and 9 years (n 378).

Results:

A higher density of predominantly UPF stores and a lower percentage of green space were associated with higher total (β: 0·12; 95 % CI 0·06, 0·18 and β: –0·10; 95 % CI –0·16, –0·04, respectively) and android body fat (β: 0·28; 95 % CI 0·13, 0·43 and β: –0·18; 95 % CI –0·32, –0·04, respectively). In addition, the densities of PA facilities and crime were inversely associated with leptin concentrations. Traffic accidents density and percentage of green spaces around schools had, respectively, a positive and an inverse association with concentrations of adiponectin and RBP4.

Conclusions:

Obesogenic environmental characteristics around schools were associated with total and android body fat, as well as with pro-inflammatory adipokine concentrations in Brazilian children from a medium-sized city.
Entangled in the Web of Conflicts
Authors: Butkutė Lina , Mortelmans Dimitri , Sondaitė Jolanta
Published: August 2023

Abstract: Introduction: Previous research findings painted a mixed picture regarding conflictual divorce. A lack of empirical clarity hinders professionals from intervening with this population effectively. Methods: Based on two-wave interview data with 21 divorcing individuals from Lithuania, we explored an array of conflicts that could be related to enduring divorce lasting from 6 months up to 4 years. Results: The results show conflictual divorce as a multifaceted, evolving phenomenon intertwined between many disputes on five interconnected levels. The most prominent ones are with a former spouse and related to self-concept changes. Over time, these conflicts partially transform into disagreements with involved institutions and the country’s legal system. In the end, divorcees become involved in enduring uncertainty and embracing inner resources to continue their journey. Conclusion: Positioning enduring divorce within multiple conflict levels identifies several points associated professionals can use in their work with divorcees and the fundamental need for collaboration among stakeholders for effective interventions.
Detection of Ore‐Forming Elements Migrated From Rock and Soil to Vegetation Leaves Using Hyperspectral Data
Authors: Chao Zhou , Xianchuang Fan , Tong Wu , Yuanzhi Zhang , Shengbo Chen
Published: August 2023

In this paper, we present the detection of ore‐forming elements migrated from soil and rock to vegetation leaves using hyperspectral data. The rock, soil (C, B, and A layer), and vegetation (root, stem, and leaf) samples with the measurements of spectra and element concentrations in the vertical section of the abandoned pits were collected. The wavelet approach is applied to analyze the correlations between spectral features and element concentrations. The results show that the significant correlations are found at a lower order mother wavelets such as Haar. Moreover, the significant correlations are negative between Cu and Mo elements and the wavelet energy vector of the soil and rock to vegetation leaves spectrum. The results also show that ore‐forming elements migrated from rock and soil to vegetation leaves can be detected using hyperspectral data in the study area.
Higher Temperatures in Socially Vulnerable US Communities Increasingly Limit Safe Use of Electric Fans for Cooling
Authors: Parsons L. A. , Lo F. , Ward A. , Shindell D. , Raman S. R.
Published: August 2023

As the globe warms, people will increasingly need affordable, safe methods to stay cool and minimize the worst health impacts of heat exposure. One of the cheapest cooling methods is electric fans. Recent research has recommended ambient air temperature thresholds for safe fan use in adults. Here we use hourly weather reanalysis data (1950–2021) to examine the temporal and spatial evolution of ambient climate conditions in the continental United States (CONUS) considered safe for fan use, focusing on high social vulnerability index (SVI) regions. We find that although most hours in the day are safe for fan use, there are regions that experience hundreds to thousands of hours per year that are too hot for safe fan use. Over the last several decades, the number of hours considered unsafe for fan use has increased across most of the CONUS (on average by ∼70%), with hotspots across the US West and South, suggesting that many individuals will increasingly need alternative cooling strategies. People living in high‐SVI locations are 1.5–2 times more likely to experience hotter climate conditions than the overall US population. High‐SVI locations also experience higher rates of warming that are approaching and exceeding important safety thresholds that relate to climate adaptation. These results highlight the need to direct additional resources to these communities for heat adaptive strategies.
Obukhov Length Estimation From Spaceborne Radars
Authors: O’Driscoll Owen , Mouche Alexis , Chapron Bertrand , Kleinherenbrink Marcel , López‐Dekker Paco
Published: August 2023

Two air‐sea interaction quantification methods are employed on synthetic aperture radar (SAR) scenes containing atmospheric‐turbulence signatures. Quantification performance is assessed on Obukhov length L, an atmospheric surface‐layer stability metric. The first method correlates spectral energy at specific turbulence‐spectrum wavelengths directly to L. Improved results are obtained from the second method, which relies on a machine‐learning algorithm trained on a wider array of SAR‐derived parameters. When applied on scenes containing convective signatures, the second method is able to predict approximately 80% of observed variance with respect to validation. Estimated wind speed provides the bulk of predictive power while parameters related to the kilometer‐scale distribution of spectral energy contribute to a significant reduction in prediction errors, enabling the methodology to be applied on a scene‐by‐scene basis. Differences between these physically based estimates and parameterized numerical models may guide the latter's improvement.
Expected EMIC Wave Generation and Unexpected MS Wave Disruption in a Magnetic Dip
Authors: Zhao Yingying , Zhu Hui , Chen Huicong
Published: August 2023

Magnetic dip plays a potentially important role in the ring‐current‐radiation‐belt‐coupling. Here, we report a proton‐driven magnetic dip event accompanied by the expected generation of electromagnetic ion cyclotron (EMIC) wave and the unexpected disruption of fast magnetosonic (MS) wave observed by the Van Allen Probe B on 03 November 2015. The effect of magnetic dip on the EMIC wave generation and MS wave propagation is analyzed. The analysis of EMIC wave instability demonstrates that EMIC waves are more easily excited in the magnetic dip. Moreover, the cold plasma density shows a highly positive correlation with the magnetic field fluctuation, and they are closely related to the disappearance of MS wave during the magnetic dip structure, which is confirmed by theoretical estimation. Our results indicate that magnetic dip may play different roles in the activities of EMIC and MS waves, which has rarely been discussed before.
Enhancer remodeling activates NOTCH3 signaling to confer chemoresistance in advanced nasopharyngeal carcinoma
Authors: Liu Lizhen , Deng Peng , Liu Sailan , Hong Jing Han , Xiao Rong , Guan Peiyong , Wang Yali , Wang Peili , Gao Jiuping , Chen Jinghong , Sun Yichen , Chen Jianfeng , Mai Hai-Qiang , Tan Jing
Published: August 2023

Acquired resistance to chemotherapy is one of the major causes of mortality in advanced nasopharyngeal carcinoma (NPC). However, effective strategies are limited and the underlying molecular mechanisms remain elusive. In this study, through transcriptomic profiling analysis of 23 tumor tissues, we found that NOTCH3 was aberrantly highly expressed in chemoresistance NPC patients, with NOTCH3 overexpression being positively associated with poor clinical outcome. Mechanistically, using an established NPC cellular model, we demonstrated that enhancer remodeling driven aberrant hyperactivation of NOTCH3 in chemoresistance NPC. We further showed that NOTCH3 upregulates SLUG to induce chemo-resistance of NPC cells and higher expression of SLUG have poorer prognosis. Genetic or pharmacological perturbation of NOTCH3 conferred chemosensitivity of NPC in vitro and overexpression of NOTCH3 enhanced chemoresistance of NPC in vivo. Together, these data indicated that genome-wide enhancer reprogramming activates NOTCH3 to confer chemoresistance of NPC, suggesting that targeting NOTCH3 may provide a potential therapeutic strategy to effectively treat advanced chemoresistant NPC.
Heterogenous electromediated depolymerization of highly crystalline polyoxymethylene
Authors: Zhou Yuting , Rodríguez-López Joaquín , Moore Jeffrey S.
Published: August 2023

Post-consumer plastic waste in the environment has driven the scientific community to develop deconstruction methods that yield valued substances from these synthetic macromolecules. Electrocatalysis is a well-established method for achieving challenging transformations in small molecule synthesis. Here we present the first electro-chemical depolymerization of polyoxymethylene—a highly crystalline engineering thermoplastic (Delrin®)—into its repolymerizable monomer, formaldehyde/1,3,5-trioxane, under ambient conditions. We investigate this electrochemical deconstruction by employing solvent screening, cyclic voltammetry, divided cell studies, electrolysis with redox mediators, small molecule model studies, and control experiments. Our findings determine that the reaction proceeds via a heterogeneous electro-mediated acid depolymerization mechanism. The bifunctional role of the co-solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) is also revealed. This study demonstrates the potential of electromediated depolymerization serving as an important role in sustainable chemistry by merging the concepts of renewable energy and circular plastic economy.
SARS-CoV-2 vaccination, booster, and infection in pregnant population enhances passive immunity in neonates
Authors: Murphy Elisabeth A. , Guzman-Cardozo Camila , Sukhu Ashley C. , Parks Debby J. , Prabhu Malavika , Mohammed Iman , Jurkiewicz Magdalena , Ketas Thomas J. , Singh Sunidhi , Canis Marie , Bednarski Eva , Hollingsworth Alexis , Thompson Embree M. , Eng Dorothy , Bieniasz Paul D. , Riley Laura E. , Hatziioannou Theodora , Yang Yawei J.
Published: August 2023

The effects of heterogeneous infection, vaccination and boosting histories prior to and during pregnancy have not been extensively studied and are likely important for protection of neonates. We measure levels of spike binding antibodies in 4600 patients and their neonates with different vaccination statuses, with and without history of SARS-CoV-2 infection. We investigate neutralizing antibody activity against different SARS-CoV-2 variant pseudotypes in a subset of 259 patients and determined correlation between IgG levels and variant neutralizing activity. We further study the ability of maternal antibody and neutralizing measurements to predict neutralizing antibody activity in the umbilical cord blood of neonates. In this work, we show SARS-CoV-2 vaccination and boosting, especially in the setting of previous infection, leads to significant increases in antibody levels and neutralizing activity even against the recent omicron BA.1 and BA.5 variants in both pregnant patients and their neonates.
Single-cell analysis of lizard blastema fibroblasts reveals phagocyte-dependent activation of Hedgehog-responsive chondrogenesis
Authors: Vonk Ariel C. , Zhao Xiaofan , Pan Zheyu , Hudnall Megan L. , Oakes Conrad G. , Lopez Gabriela A. , Hasel-Kolossa Sarah C. , Kuncz Alexander W. C. , Sengelmann Sasha B. , Gamble Darian J. , Lozito Thomas P.
Published: August 2023

Lizards cannot naturally regenerate limbs but are the closest known relatives of mammals capable of epimorphic tail regrowth. However, the mechanisms regulating lizard blastema formation and chondrogenesis remain unclear. Here, single-cell RNA sequencing analysis of regenerating lizard tails identifies fibroblast and phagocyte populations linked to cartilage formation. Pseudotime trajectory analyses suggestspp1+-activated fibroblasts as blastema cell sources, with subsets exhibitingsulf1expression and chondrogenic potential. Tail blastema, but not limb, fibroblasts expresssulf1and form cartilage under Hedgehog signaling regulation. Depletion of phagocytes inhibits blastema formation, but treatment with pericytic phagocyte-conditioned media rescues blastema chondrogenesis and cartilage formation in amputated limbs. The results indicate a hierarchy of phagocyte-induced fibroblast gene activations during lizard blastema formation, culminating insulf1+pro-chondrogenic populations singularly responsive to Hedgehog signaling. These properties distinguish lizard blastema cells from homeostatic and injury-stimulated fibroblasts and indicate potential actionable targets for inducing regeneration in other species, including humans.
Mechanism of U6 snRNA oligouridylation by human TUT1
Authors: Yamashita Seisuke , Tomita Kozo
Published: August 2023

U6 snRNA is a catalytic RNA responsible for pre-mRNA splicing reactions and undergoes various post-transcriptional modifications during its maturation process. The 3'-oligouridylation of U6 snRNA by the terminal uridylyltransferase, TUT1, provides the Lsm-binding site in U6 snRNA for U4/U6 di-snRNP formation and this ensures pre-mRNA splicing. Here, we present the crystal structure of human TUT1 (hTUT1) complexed with U6 snRNA, representing the post-uridylation of U6 snRNA by hTUT1. The N-terminal ZF-RRM and catalytic palm clamp the single-stranded AUA motif between the 5'-short stem and the 3'-telestem of U6 snRNA, and the ZF-RRM specifically recognizes the AUA motif. The ZF and the fingers hold the telestem, and the 3'-end of U6 snRNA is placed in the catalytic pocket of the palm for oligouridylation. The oligouridylation of U6 snRNA depends on the internal four-adenosine tract in the 5'-part of the telestem of U6 snRNA, and hTUT1 adds uridines until the internal adenosine tract can form base-pairs with the 3'-oligouridine tract. Together, the recognition of the specific structure and sequence of U6 snRNA by the multi-domain TUT1 protein and the intrinsic sequence and structure of U6 snRNA ensure the oligouridylation of U6 snRNA.
Stepwise modifications of transcriptional hubs link pioneer factor activity to a burst of transcription
Authors: Cho Chun-Yi , O’Farrell Patrick H.
Published: August 2023

Binding of transcription factors (TFs) promotes the subsequent recruitment of coactivators and preinitiation complexes to initiate eukaryotic transcription, but this time course is usually not visualized. It is commonly assumed that recruited factors eventually co-reside in a higher-order structure, allowing distantly bound TFs to activate transcription at core promoters. We use live imaging of endogenously tagged proteins, including the pioneer TF Zelda, the coactivator dBrd4, and RNA polymerase II (RNAPII), to define a cascade of events upstream of transcriptional initiation in early Drosophila embryos. These factors are sequentially and transiently recruited to discrete clusters during activation of non-histone genes. Zelda and the acetyltransferase dCBP nucleate dBrd4 clusters, which then trigger pre-transcriptional clustering of RNAPII. Subsequent transcriptional elongation disperses clusters of dBrd4 and RNAPII. Our results suggest that activation of transcription by eukaryotic TFs involves a succession of distinct biomolecular condensates that culminates in a self-limiting burst of transcription.
MTH1 protects platelet mitochondria from oxidative damage and regulates platelet function and thrombosis
Authors: Ding Yangyang , Gui Xiang , Chu Xiang , Sun Yueyue , Zhang Sixuan , Tong Huan , Ju Wen , Li Yue , Sun Zengtian , Xu Mengdi , Li Zhenyu , Andrews Robert K. , Gardiner Elizabeth E. , Zeng Lingyu , Xu Kailin , Qiao Jianlin
Published: August 2023

Human MutT Homolog 1 (MTH1) is a nucleotide pool sanitization enzyme that hydrolyzes oxidized nucleotides to prevent their mis-incorporation into DNA under oxidative stress. Expression and functional roles of MTH1 in platelets are not known. Here, we show MTH1 expression in platelets and its deficiency impairs hemostasis and arterial/venous thrombosis in vivo. MTH1 deficiency reduced platelet aggregation, phosphatidylserine exposure and calcium mobilization induced by thrombin but not by collagen-related peptide (CRP) along with decreased mitochondrial ATP production. Thrombin but not CRP induced Ca2+-dependent mitochondria reactive oxygen species generation. Mechanistically, MTH1 deficiency caused mitochondrial DNA oxidative damage and reduced the expression of cytochrome c oxidase 1. Furthermore, MTH1 exerts a similar role in human platelet function. Our study suggests that MTH1 exerts a protective function against oxidative stress in platelets and indicates that MTH1 could be a potential therapeutic target for the prevention of thrombotic diseases.
Expanding the limits of nuclear stability at finite temperature
Authors: Ravlić Ante , Yüksel Esra , Nikšić Tamara , Paar Nils
Published: August 2023

Properties of nuclei in hot stellar environments such as supernovae or neutron star mergers are largely unexplored. Since it is poorly understood how many protons and neutrons can be bound together in hot nuclei, we investigate the limits of nuclear existence (drip lines) at finite temperature. Here, we present mapping of nuclear drip lines at temperatures up to around 20 billion kelvins using the relativistic energy density functional theory (REDF), including treatment of thermal scattering of nucleons in the continuum. With extensive computational effort, the drip lines are determined using several REDFs with different underlying interactions, demonstrating considerable alterations of the neutron drip line with temperature increase, especially near the magic numbers. At temperatures T ≲ 12 billion kelvins, the interplay between the properties of nuclear effective interaction, pairing, and temperature effects determines the nuclear binding. At higher temperatures, we find a surprizing result that the total number of bound nuclei increases with temperature due to thermal shell quenching. Our findings provide insight into nuclear landscape for hot nuclei, revealing that the nuclear drip lines should be viewed as limits that change dynamically with temperature.
Climate intervention on a high-emissions pathway could delay but not prevent West Antarctic Ice Sheet demise
Authors: Sutter J. , Jones A. , Frölicher T. L. , Wirths C. , Stocker T. F.
Published: August 2023

Solar radiation modification (SRM) is increasingly discussed as a tool to reduce or avert global warming and concomitantly the risk of ice-sheet collapse, as is considered possible for the West Antarctic Ice Sheet (WAIS). Here we analyse the impact of stratospheric aerosol injections on the centennial-to-millennial Antarctic sea-level contribution using an ice-sheet model. We find that mid-twenty-first-century large-scale SRM could delay but ultimately not prevent WAIS collapse in a high-emissions scenario. On intermediate-emissions pathways, SRM could be an effective tool to delay or even prevent an instability of WAIS if deployed by mid-century. However, SRM interventions may be associated with substantial risks, commitments and unintended side effects; therefore, emissions reductions to prevent WAIS collapse seem to be the more practical and sensible approach at the current stage.
Cooperative contributions of the klf1 and klf17 genes in zebrafish primitive erythropoiesis
Authors: Suzuki Hiroaki , Ogawa Tomotaka , Fujita Shigeyoshi , Sone Ryota , Kawahara Atsuo
Published: August 2023

Krüppel-like transcription factors (Klfs), which are characterized by the three conserved C-terminal zinc fingers, are involved in various biological processes, such as haematopoiesis and angiogenesis. However, how the Klf family of transcription factors cooperate in organogenesis remains elusive. During zebrafish embryogenesis, both klf1 and klf17 are expressed in the intermediate cell mass (ICM), where primitive erythroid cells are produced. Using CRISPR–Cas9 genome editing technology, we established klf1-klf17 double mutant zebrafish to investigate the functionally interactive roles of the klf1 and klf17 genes. The klf1-klf17 mutant exhibited a diminished number of circulating primitive erythroid cells at 2 days postfertilization (dpf), while klf1 or klf17 single mutants and wild-type embryos produced comparable numbers of primitive erythroid cells. Circulating erythroid cells from the klf1-klf17 mutant possessed larger nuclei at 2 dpf than wild-type cells, suggesting the impairment of primitive erythroid cell maturation. The expression of the erythroid cell maturation markers band3 and mitoferrin, but not the haematopoietic progenitor markers c-myb and scl, was decreased in the klf1-klf17 mutant at 1 dpf. Thus, these results illustrate the cooperative function of klf1 and klf17 in the maturation processes of zebrafish primitive erythroid cells.
A novel approach for enhancing the color and antimicrobial properties of pine and beech wood using Se-NPs
Authors: Elmaaty Tarek Abou , Swidan Abeer , Sayed-Ahmed Khaled , Zaghloul Nancy
Published: August 2023

Pine wood (PW) and beech wood (BW) are the most used wood in furniture and other applications owing to their unique characteristics and low machining cost. However, their biodegradability and varied moisture content limit their wider use and durability. Therefore, in this study, nanotechnology was used as a novel eco-friendly approach to enhance the durability, antimicrobial properties, and color of wood. Selenium nanoparticles (Se-NPs) were prepared in spherical shape at varied concentrations (25 and 50 mM) using an eco-friendly method in the range of 35–80 and 40–155 nm, respectively. Se-NPs formation at the nanoscale was confirmed using UV/Vis analysis, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The prepared Se-NPs were then impregnated into PW and BW for different periods ranging from 2 h to 1 week. The treated wood were then leached in distilled water for 14 days to eliminate excess Se-NPs from the wood surface. The treated wood surfaces were examined using energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). In addition, the depth of Se-NPs penetration into the treated wood at both tangential and radial sides was determined. Se-NPs impacts on the color properties, density, moisture content and antimicrobial activities of the treated wood were evaluated. PW treated with Se-NPs showed better antimicrobial and color characteristics than treated BW. PW samples immersed in 50 mM Se-NPs for 2 h showed the highest K/S values, whereas the highest antimicrobial values were obtained for those immersed at the same concentration for 2 days, and 1 week.
Optical fiber speckle spectrometer based on reversed-lens smartphone microscope
Authors: Tan Henry , Li Bingxi , Crozier Kenneth B.
Published: August 2023

Smartphones are a potentially powerful platform for scientific instruments. Here, we demonstrate speckle spectroscopy with smartphone-level hardware. This technique promises greater performance thresholds than traditional diffraction gratings. Light is injected into an optical fiber and the emergent speckle patterns are imaged by a reversed-lens smartphone camera. The smartphone then uses an algorithm, running on a mobile computing app, to determine, in less than one second, the (hitherto unknown) input spectrum. We reconstruct a variety of visible-wavelength (470–670 nm) single and multi-peaked spectra using a tunable source. The latter also include a metameric pair, i.e., two spectra that are different, yet represent colors that are indistinguishable to the human eye.
HOXA13 promotes the proliferation, migration, and invasion of nasopharyngeal carcinoma HNE1 cells by upregulating the expression of Snail and MMP-2
Authors: Liu Jinping , Feng Huajun , Wang Dingting , Wang Yuanyuan , Luo Jian , Xu Shengen , Zhao Feipeng , Qin Gang
Published: August 2023

Homeobox A13 (HOXA13) has been verified as an oncogen in some malignancies. However, its role in nasopharyngeal carcinoma (NPC) is still unclear. This study aims to explore the role of HOXA13 in NPC and its underlying mechanism. The mRNA expression of HOXA13 in NPC was obtained from the GSE53819 and GSE64634 datasets in the Gene Expression Omnibus (GEO) database. MTT, colony formation and transwell assays and xenograft tumour models were used to investigate the effects of HOXA13 on NPC HNE1 cells in vitro and in vivo. The expression of HOXA13, epithelial-mesenchymal transition-transcription factor (EMT-TF) Snail and matrix metalloproteinase 2 (MMP-2) was detected by immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The results showed that HOXA13 was upregulated in NPC. Silencing HOXA13 suppressed the proliferation, migration, and invasion of HNE1 cells, which inhibited tumour growth, while overexpression of HOXA13 induced the opposite effects. In addition, the expression of Snail and MMP-2 at the transcriptional and protein levels was associated with the expression of HOXA13. In summary, our results suggest that HOXA13 plays a role as a cancer-promoting gene in NPC. The underlying mechanism may be related to the upregulation of Snail and MMP-2.
Analysis of risk factors for postoperative delirium in middle-aged and elderly fracture patients in the perioperative period
Authors: An Zhongcheng , Xiao Liangen , Chen Chen , Wu Lianguo , Wei Hao , Zhang Xiaoping , Dong Liqiang
Published: August 2023

To investigate the incidence rate and risk factors of postoperative delirium in middle-aged and elderly patients with fracture. A total of 648 middle-aged and elderly fracture patients who underwent surgical treatment in our hospital from January 2018 to December 2020 were included in the study, aged 50–103 years, mean 70.10 ± 11.37 years. The incidence of postoperative delirium was analyzed. Univariate analysis was used to screen the risk factors of gender, age, interval between injury and operation, preoperative complications, fracture site, anesthesia method, operation time, intraoperative blood loss, hidden blood loss and hormone use. For the factors with P < 0.05, multivariate logistic regression analysis was used to determine the main independent risk factors. 115 cases (17.74%) of 648 patients had postoperative delirium. Univariate analysis showed that patients with delirium and patients without delirium had significant correlation in age, medical disease comorbidity, fracture type, anesthesia method, operation time and perioperative blood loss (P < 0.05). Multivariate logistic regression analysis showed that age (OR = 1.061), preoperative complications (OR = 1.667), perioperative blood loss (OR = 1.002) were positively correlated with postoperative delirium. It shows that older age, more preoperative complications, longer operation time and more perioperative bleeding are more likely to lead to postoperative delirium; patients with general anesthesia were more likely to develop postoperative delirium than patients with local anesthesia (OR = 1.628); and patients with hip and pelvic fractures are more likely to develop a postoperative delirious state (OR = 1.316). Advanced age, complex orthopedic surgery, more medical comorbidities, general anesthesia and greater perioperative blood loss may be independent risk factors for the development of delirium after internal fixation of fractures in middle-aged and elderly patients.
Study on evaluation method for driving fragment ability of explosives
Authors: Zhou Jiajie , Kong Deren , Shang Fei
Published: August 2023

The present study proposes an evaluation method for the driving fragment ability of explosives, which aims to provide theoretical and technical support for the selection of explosives used in warheads. The evaluation method is proposed in the light of the dimensional method and the similarity principle, and it uses TNT equivalent as the evaluation indicator. To acquire the evaluation indicator, a test system for driving fragment ability of explosives is constructed, which includes a dynamite gun type driven device, a spherical fragment, and a multi-zone fragment velocity measurement system. TNT and thermobaric explosive were used to carry out the verification experiments of the evaluation method. On the basis of the evaluation method, the basic evaluation model for the driving fragment ability of explosives was established by the TNT mass and the corresponding fragment maximum velocity. Using the basic evaluation model, the TNT equivalent of the thermobaric explosive in driving fragment ability was calculated to be 1.29, which was 3.2% different from the ratio (1.25) of both explosives’ Gurney-specific energy. The relative error of 3.2% falls within the allowable range of engineering error, confirming the feasibility of the proposed evaluation method. The result shows that the proposed evaluation method is effective and accurate in evaluating the driving fragment ability of explosives.
Interaction of 2-propanol with predominantly SrO- and TiO2-terminated SrTiO3(100) surfaces studied by vibrational sum frequency spectroscopy
Authors: Bera Anupam , Bullert Denise , Linke Matthias , Franzka Steffen , Hagemann Ulrich , Hartmann Nils , Hasselbrink Eckart
Published: August 2023

The interaction of 2-propanol with SrTiO3(100) surfaces is studied with a focus on the role of different surface terminations in the deprotonation upon adsorption.
Nitrides: a promising class of nonlinear optical material candidates
Authors: Zhao Xin , Lin Chensheng , Tian Haotian , Wang Chao , Ye Ning , Luo Min
Published: August 2023

Nitrides are an emerging and promising class of nonlinear optical (NLO) crystals, in this review, recently reported and potential NLO nitrides are summarized and categorized into three groups based on their structural features.