bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of thermal swing piston insulation at single cylinder gasoline engine
Authors: Weßling Danny , Rottengruber Hermann , Achenbach Jens , Fischer Torsten
Published: April 2023

The reduction of carbon dioxide emissions and the corresponding increase in gasoline engine efficiency are crucial in engine development. Wall heat losses are a major cause of efficiency loss, accounting for 15–30% of the total fuel energy. One promising solution is the use of "thermal swing" coatings at the combustion chamber walls because of offering the possibility that the surface wall temperature following the working gas temperature, whereby the wall heat transfer can be reduced at any time during the engine cycle. This type of coating material is characterized by low thermal conductivity and, at the same time, low heat capacity. Based on the idea of the “thermal swing” coatings, yttria stabilized zirconia (YSZ) was selected as the coating material for the piston surface and its efficiency potential was experimentally investigated on a single-cylinder gasoline engine. The use of highly dynamic temperature probes in the piston allowed precise analysis of cycle-based temperature fluctuations, especially on the piston surface. The transmission of the piston temperatures was cable-based and accomplished through the use of a lever system in the engine. The measurement results confirmed the minimal impact on the efficiency that was determined in preliminary simulations. However, the effect of the coating could be established through the measurements.
Building an authentic African philosophy of education based on the African concept of personhood
Authors: Balogun Babalola Joseph
Published: April 2023

This paper’s central task is to demonstrate how the African concept of personhood provides a suitable grounding for an authentic African philosophy of education. An authentic African philosophy of education is one in which there is a constant search for underlying principles for reflecting on the foundation, nature, and justification for the need and desirability of education in Africa. Scholars have drawn diverse implications from the African concept of personhood, especially in the areas of normative ethics, social and political, and legal philosophies. However, sufficient attention has not yet been paid to how the African conception of personhood could drive fruitful theoretical engagements with the foundations, nature, and justification of the African philosophy of education. This paper attempts to fill this gap. With the combination of critical literature review and philosophical methods of conceptual and logical analyses (and argumentation), the paper argues for the centrality of an African concept of personhood to the questions of the foundation, form (nature), and justification of an authentic African philosophy of education. The paper concludes that a personhood-based African philosophy of education provides a plausible framework within which these questions can be fruitfully engaged.
Company Cost of Capital and Leverage: A Simplified Textbook Relationship Revisited
Authors: Haag Valentin , Koziol Christian
Published: April 2023

In this paper, we revisit a frequently employed simplification within the WACC approach that company cost of capital $$k_{V}$$

k
V

is supposed to be invariant to the debt ratio and therefore equal to the unlevered cost $$k_{U}$$

k
U

. Even though we know from Miles and Ezzell (1980) that $$k_{V}$$

k
V

formally differs from $$k_{U}$$

k
U

, treating both costs as equal strongly facilitates the practical firm valuation e.g. when companies strategically change their target debt ratios to a significantly different magnitude after a transaction. We provide both a theoretical model and an empirical analysis using 29 firms of the German stock market to quantify the economic significance between the company cost of a levered and an otherwise identical but unlevered firm. In particular, we can numerically support the usual simplification in the absence of default risk. In case that firms are default-risky, however, empirical findings indicate a clear difference between these costs equal to 1.88 percentage points on average even for moderate assumed bankruptcy costs which translates to a company mispricing of nearly 100%. As a result, the company cost of capital does practically not depend on the debt ratio if the firm is not subject to default risk or if bankruptcy costs are negligible. Otherwise, it does and a negligence of this relationship can cause significant mispricings.
Geochemical distribution in residual soils of Iberian Pyrite Belt (Spain)
Authors: Martín-Méndez Iván , Llamas Borrajo Juan , Bel-lan Alejandro , Locutura Juan
Published: April 2023

The Iberian Pyrite Belt (IPB) is a volcanic- and shale-hosted massive sulfides world-class province of the Upper Paleozoic age that includes some supergiant ore deposits with a unique mining operations history. An extensive soil (multi-element) geochemical survey in the IPB has been performed to create a geochemical database to increase the knowledge of the studied area. Both univariate and multivariate treatments have been done to manage a large amount of new data. The studied area shows higher background concentrations of several elements (e.b. Cu, Pb, Zn, Cd, Sn, In, Bi, As, or Sb) than in other terrains in Spain due to the IPB volcano-sedimentary ore deposits and their associated mining wastes. Mapping chemical elements help understand their behavior, controls and associations in natural environments. According to this, the mono-elemental contour maps show single-element distributions with geological control (e.g., Na), ore deposit control (e.g., Cu) or a mixture of both. On the other hand, multivariate analysis has been applied to reduce the large geochemical database maintaining the same information. We have chosen Factorial Analysis (FA) and obtained six factors that explain approximately 70% of the variability. Four of these factors (F1, F2, F4 and F5) show an intense geological control that improves the geological information of the IPB, while the other two (F3 and F5) show an ore deposit control. These factors allow distinguishing between different types of deposits in the IPB and help discover new possible exploration targets for future studies.
Everyday life and Everyday Leisure
Authors: Veal A.J
Published: April 2023

A substantial body of theory exists on the concept of everyday life, including the sociology of everyday life, but it has barely featured in the mainstream of the sociological study of leisure or leisure studies more broadly. This paper explores this theoretical work and considers the place of leisure in it, and how it might inform the further development of the study of leisure. It is argued that the time is right to broaden the scope of leisure research to incorporate consideration of the way in which all forms of everyday time-use interact.
Nutzung und Bedingungsfaktoren informeller Lerngelegenheiten von Lehrpersonen in Deutschland
Authors: Röhl Sebastian , Groß Ophoff Jana , Johannmeyer Karen , Cramer Colin
Published: April 2023

Die professionelle Tätigkeit als Lehrperson an Schulen bedarf einer fortlaufenden berufsbegleitenden Professionalisierung im gesamten Prozess der berufsbiografischen Entwicklung. Neben dem Besuch von Fort- und Weiterbildungen umfasst dieses Lernen auch die Nutzung so genannter informeller Lerngelegenheiten, die außerhalb von organisierten Veranstaltungen im Berufsalltag existieren und durch die Lehrperson selbst initiiert werden. In dieser Studie wird das bisher nur wenig erforschte Feld der berufsbegleitenden Professionalisierung von Lehrpersonen in den Blick genommen. Auf Grundlage einer repräsentativen schriftlichen Befragung vonN = 405 Lehrpersonen aus Deutschland werden die faktorielle Struktur, die Nutzungshäufigkeiten informeller Lerngelegenheiten und ihre personalen und strukturellen Determinanten mithilfe von Strukturgleichungsmodellen analysiert. Die Befunde weisen insbesondere auf prädiktive Effekte einzelner demografischer und dispositionaler Merkmale der Lehrpersonen (Alter, Geschlecht, Quer- und Seiteneinstieg, Selbstwirksamkeitserwartung), aber auch von Berufsmerkmalen (Übernahme erweiterter Aufgaben und Funktionen in der Schule) auf die Nutzungshäufigkeit informeller Lerngelegenheiten hin. Schließlich zeigen sich Hinweise auf die Notwendigkeit einer Unterscheidung von Print- und Onlinemedien mit Blick auf das Rezeptionsverhalten. Die Rolle informeller Lerngelegenheiten im Kontext des gesamten Professionalisierungsprozesses von Lehrpersonen wird diskutiert.
Hans J. Morgenthau’s Critique of Legal Positivism: Politics, Justice, and Ethics in International Law
Authors: Chas Carmen
Published: April 2023

Modern jurisprudence has typically been presented as a debate between legal positivism and natural law. Though the demise of legal positivism has been touted despite its pre-eminence in past decades, it is clear that there remains a vigorous debate surrounding this theory. It is noteworthy that Hans J. Morgenthau’s legal thought and critique of legal positivism have remained unexplored in the context of this debate. Largely forgotten, his legal thought answers questions that lie at the heart of the natural law and legal positivist debate. It showcases his deeply nuanced understanding of legal and political theory and contains a powerful and insightful commentary on the fundamental problems faced by international law. Building on existing literature, this paper unearths Morgenthau’s critique of legal positivism. It does this by re-examining his works, which address the question of whether moral considerations are relevant to determining the content of the law in force. It brings his legal thought to light, which highlights the artificiality of the division between law and morality and offers a nuanced analysis of problems inherent in international law. Ultimately, the paper challenges the claim that the law can be determined without resorting to moral judgement and shows how Morgenthau’s insights remain relevant to legal positivism and natural law debates today.
Inter-screw index as a novel diagnostic indicator of tether breakage
Authors: Wan Sandra H. T. , Guldeniz Ogulcan , Yeung Matthew H. Y. , Cheung Jason P. Y. , Kwan Kenny Y. H. , Cheung Kenneth M. C.
Published: April 2023

Purpose

Tether breakage is the most common complication of Vertebral Body Tethering (VBT) occurring in up to 52% of Adolescent Idiopathic Scoliosis (AIS) patients and risks continued progression and revision. Radiographical diagnosis of tether breakage is commonly defined by a 5° increase in inter-screw angle and associates breakage with loss of correction. However, the sensitivity of this method was 56% only, suggesting that tethers can break without an increase in angulation, which was supported by other studies. To our knowledge, current literature lacks a method merely focusing on the diagnosis of tether breakage radiographically that does not associate the breakages with loss of correction.

Methods

This was a retrospective review of prospectively collected data of AIS patients who underwent VBT. The “inter-screw index” is defined as the percentage increase in inter-screw distance since post-op, with ≥ 13% increase defined as tether breakage as suggested by our mechanical tests. CTs were reviewed to identify the breakages and compared with inter-screw angle and inter-screw index.

Results

94 segments from 13 CTs were reviewed, and 15 tether breakages were identified. Use of inter-screw index correctly identified 14 breakages (93%), whereas ≥ 5° increase in inter-screw angle only identified 12 breakages (80%).

Conclusion

Use of inter-screw index is proven to be more sensitive than inter-screw angle in identifying tether breakages. Therefore, we propose the use of inter-screw index to diagnose tether breakages radiographically. Tether breakages were not necessarily accompanied by a loss of segmental correction leading to an increase in inter-screw angle, especially after skeletal maturity.

Level of evidence

Level 3.
A simple retarding-potential time-of-flight mass spectrometer for electrospray propulsion diagnostics
Authors: Lyne Christopher T. , Liu Miron F. , Rovey Joshua L.
Published: April 2023

The time-of-flight mass spectrometer (ToF-MS) is a useful tool for quantifying the performance of electrospray thrusters and characterizing their plumes. ToF-MS data can be used to calculate the mass-to-charge distribution in the plume, but the kinetic-energy-to-charge (i.e., the potential) distribution must be known first. Here we use a ToF-MS in tandem with a retarding potential (RP) analyzer. By sweeping the retarding potential through the range of potentials present in the plume, both the mass-to-charge distribution and the potential distribution can be measured independently. We demonstrate this technique in a case study using a capillary electrospray emitter and the ionic liquid propellant 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, abbreviated EMI-Im. We report a linear correlation between retarding potential and mass-to-charge ratio that agrees with published data from more complex orthogonal RP/ToF-MS instruments. Calculated values for the jet velocity and jet breakup potential match within 2% and 12%, respectively. Using conventional ToF-MS, we estimated the propellant flow rate and compared those estimates to direct flow rate measurements. For flow rates between 233 pL/s and 565 pL/s, the error in ToF-based flow rate estimates ranged from -16% to -13% when the plume potential was assumed to be a function of mass-to-charge. Assuming a constant plume potential yielded mixed results. However, using the average stopping potential measured by a retarding potential analyzer resulted in higher errors, ranging from -26% to -30%. Data and MATLAB code are included as supplemental materials so that readers can easily apply the techniques described here.
Pituitary Dysfunction in Idiopathic Intracranial Hypertension: An Analysis of 80 Patients
Authors: Prabhat Nandita , Kaur Kirandeep , Takkar Aastha , Ahuja Chirag , Katoch Deeksha , Goyal Manoj , Dutta Pinaki , Bhansali Anil , Lal Vivek
Published: April 2023

Background:

Empty sella is a commonly described imaging entity in patients with idiopathic intracranial hypertension (IIH). Though menstrual and hormonal disturbances have been associated with IIH, available literature lacks systematic analysis of pituitary hormonal disturbances in IIH. More so, the contribution of empty sella in causing pituitary hormonal abnormalities in patients of IIH has not been described. We carried out this study to systematically assess the pituitary hormonal abnormalities in patients with IIH and its relation to empty sella.

Methods:

Eighty treatment naïve patients of IIH were recruited as per a predefined criterion. Magnetic resonance imaging (MRI) brain with detailed sella imaging and pituitary hormonal profile were done in all patients.

Results:

Partial empty sella was seen in 55 patients (68.8%). Hormonal abnormalities were detected in 30 patients (37.5%), reduced cortisol levels in 20%, raised prolactin levels in 13.8%, low thyroid-stimulating hormone (TSH) levels in 3.8%, hypogonadism in 1.25%, and elevated levels of gonadotropins were found in 6.25% of participants. Hormonal disturbances were independent and were not associated with the presence of empty sella (p = 0.493).

Conclusion:

Hormonal abnormalities were observed in 37.5% patients with IIH. These abnormalities did not correlate with the presence or absence of empty sella. Pituitary dysfunction appears to be subclinical in IIH and responds to intracranial pressure reduction, not requiring specific hormonal therapies.
REMARKS ON CONVERGENCE OF MORLEY SEQUENCES
Authors: KHANAKI KARIM
Published: April 2023

We refine results of Gannon [6, Theorem 4.7] and Simon [22, Lemma 2.8] on convergence of Morley sequences. We then introduce the notion of eventual
$NIP$
, as a property of a model, and prove a variant of [15, Corollary 2.2]. Finally, we give new characterizations of generically stable types (for countable theories) and reinforce the main result of Pillay [17] on the model-theoretic meaning of Grothendieck’s double limit theorem.
Ontogenetic responses of physiological fitness in Spodoptera frugiperda (Lepidoptera: Noctuidae) in response to repeated cold exposure
Authors: Mbande Abongile , Mutamiswa Reyard , Chidawanyika Frank
Published: April 2023

In this era of global climate change, intrinsic rapid and evolutionary responses of invasive agricultural pests to thermal variability are of concern given the potential implications on their biogeography and dire consequences on human food security. For insects, chill coma recovery time (CCRT) and critical thermal minima (CTmin), the point at which neuromuscular coordination is lost following cold exposure, remain good indices for cold tolerance. Using laboratory-reared Spodoptera frugiperda (Lepidoptera: Noctuidae), we explored cold tolerance repeated exposure across life stages of this invasive insect pest. Specifically, we measured their CTmin and CCRT across four consecutive assays, each 24 h apart. In addition, we assessed body water content (BWC) and body lipid content (BLC) of the life stages. Our results showed that CTmin improved with repeated exposure in 5th instar larvae, virgin males and females while CCRT improved in 4th, 5th and 6th instar larvae following repeated cold exposure. In addition, the results revealed evidence of cold hardening in this invasive insect pest. However, there was no correlation between cold tolerance and BWC as well as BLC. Our results show capacity for cold hardening and population persistence of S. frugiperda in cooler environments. This suggests potential of fall armyworm (FAW) to withstand considerable harsh winter environments typical of its recently invaded geographic range in sub-Saharan Africa.
City of lights, city of pylons: Infrastructures of illumination in colonial Hanoi, 1880s–1920s
Authors: Endres Kirsten W.
Published: April 2023

This article traces the early stages of urban electrification in the French protectorate of Tonkin (in Vietnam’s north) from the late 1880s to the late 1920s. It focuses on Hanoi, where in 1895 the French entrepreneurs Hermenier and Planté secured a concession for lighting the streets of the soon-to-be capital of French Indochina. Before long, the city’s fast-paced development and the concomitant rise in demand for both public and private lighting necessitated contractual amendments and further capital investment in the upgrading of the power station and grid extensions. In 1902, Hermenier converted the business into a joint stock company named the Société Indochinoise d’Électricité with the aim of enabling further growth and geographical expansion. Contractual arrangements were frequently renegotiated and adjusted to new circumstances. However, electricity supplies kept lagging behind the fast pace of demand growth. During the post-First World War years of colonial economic expansion, power failures and blackouts became a routine occurrence and were a frequent target of press coverage. It was only in the late 1920s that electricity supplies improved and turned Hanoi into a city of lights. Although the majority of Vietnamese residents remained excluded from private electricity access throughout the colonial period, electric power quickly became a fact of everyday life for an emerging Vietnamese urban bourgeoisie and served as a marker of modern sophistication. Plans for an interconnected distribution network in the Tonkin delta subsequently also triggered hopes for an electrified future for the countryside.
Roman ‘Grand Strategy’ in Action? Claudius and the Annexation of Britain and Thrace
Authors: Graafstal Erik P.
Published: April 2023

A longstanding debate among ancient historians and students of Roman frontiers concerns the reality and effective reach of Roman imperial policy. Certainly when new military commitments were involved, the slowness of supply and information meant that major moves had to be planned well in advance. This paper focuses on the provincialisation of Britain and Thrace in a.d. 43 and c. 45. The dating evidence provided by tree rings, coins and milestones suggests that logistic preparation for the invasion of Britain started at least two years before the event. This pattern, of a newly installed Emperor immediately initiating a campaign on the northern frontiers, allowing two years for logistic preparation, is seen no fewer than seven times between Caligula and Caracalla.
Stochastic comparisons of largest claim and aggregate claim amounts
Authors: Panja Arindam , Kundu Pradip , Hazra Nil Kamal , Pradhan Biswabrata
Published: April 2023

In this paper, we establish some stochastic comparison results for largest claim amounts of two sets of independent and also for interdependent portfolios under the setup of the proportional odds model. We also establish stochastic comparison results for aggregate claim amounts of two sets of independent portfolios. Further, stochastic comparisons for largest claim amounts from two sets of independent multiple-outlier claims have also been studied. The results we obtained apply to the whole family of extended distributions, also known as the Marshall–Olkin family of distributions. We have given many numerical examples to illustrate the results obtained.
Personal, behavioural and socio-environmental correlates of emerging adults’ sustainable food consumption in a cross-sectional analysis
Authors: Ludwig-Borycz Elizabeth , Neumark-Sztainer Dianne , Larson Nicole , Baylin Ana , Jones Andrew D , Webster Allison , Bauer Katherine W
Published: April 2023

Objective:

Describe how dietary intake patterns of US young adults align with the EAT-Lancet Planetary Health Diet (PHD) sustainable diet goals and identify personal, behavioural, and socio-environmental correlates of sustainable intake.

Design:

Data on past-year dietary intake were captured using a FFQ. The PHD was applied to specific food groups, and a total PHD score was calculated. Linear regression models were used to identify associations between personal, behavioural and socio-environmental factors and PHD scores.

Setting:

This cross-sectional analysis uses data from the second wave of EAT 2010–2018 (Eating and Activity over Time), a population-based longitudinal study recruited in Minnesota.

Participants:

Ethnically/racially diverse group of participants (n 1308) with a mean age of 22·1 (sd 2·0) years.

Results:

The mean PHD score was 4·1 (sd 1·4) on a scale of 0–14, with 14 representing the most sustainable. On average, participants consumed fewer whole grains, fish, legumes, soya, and nuts than ideal for a sustainable diet, and an excess of eggs, added sugar, and meat. The PHD score was higher for participants with higher socio-economic status (SES) and greater educational attainment. Higher home availability of healthy food (β = 0·24, P < 0·001) and less frequent fast-food consumption (β = –0·26, P < 0·001) were the strongest correlates of PHD scores.

Conclusions:

Results suggest that a high percentage of participants may not be achieving the sustainable diet goals defined by the PHD. Reductions in meat consumption and increases in plant-based foods are necessary to increase the sustainability of US young adults’ diets.
The poor woman’s energy: Low-modernist solar technologies and international development, 1878–1966
Authors: Chatterjee Elizabeth
Published: April 2023

Solar energy often appears a resource without a history, perpetually novel and promising futuristic abundance. This overlooks a long episode of ‘low-modernist’ solar research in and for the global South. Focusing especially on India and detouring through Mexico, two important arenas for early solar experimentation, this article traces an alternative history of solar technologies as austere everyday fixes for developing countries. In parallel with the well-known postcolonial focus on high-modernist energy mega-projects, the narrow transnational community of solar experts retained a competing tendency to think small. At its heart lay a dualistic conception of the modern energy economy: flexible and resource-intensive grid electricity for urban centres, inferior off-grid devices to meet the minimal and static needs of the rural poor. This impoverished, feminized Third World projected user base resulted in persistent underinvestment and failed commercialization, helping to explain why solar technologies did not take off earlier. While solar experts emphasized the regional exceptionalism of the arid tropics, the teleological linkage between modernity and ever-rising energy abundance was rejuvenated from below as rural communities began to imagine the high-energy good life as a universal aspiration.
Attitudes and Viewpoints Toward Prevention Trials in Alzheimer’s Disease
Authors: Pauli Philipp , Goetz Katja , Rogge Annette , Bartsch Thorsten , Philippen Sarah , Berg Daniela , Hertrampf Katrin
Published: April 2023

Abstract: Alzheimer’s disease (AD) prevention studies use biomarkers to determine risk in asymptomatic study participants. This involves multifaceted implications. Determinants regarding participation in these trials are therefore of particular relevance. We used semistructured individual interviews to interview uninvolved persons ( n = 10), relatives of Alzheimer’s patients ( n = 10), and patients with mild cognitive impairment ( n = 5) and analyzed the interviews using qualitative content analysis according to Mayring. We discovered various factors to be positive motivations for participation; the most significant inhibiting factor was concern about negative psychological effects. These motivations and concerns should be specifically addressed in the study design of AD prevention trials. The fears and concerns expressed highlight the importance of a good methodological and ethical framework to increase participant acceptance.
A Comparative Study Between Regional Atmospheric Model Simulations Coupled and Uncoupled to a Regional Ocean Model of the Indian Summer Monsoon
Authors: Jayasankar C. B. , Misra Vasubandhu , Karmakar Nirupam
Published: April 2023

We evaluate the impact of air‐sea coupling in simulating the characteristics of the Indian summer monsoon (ISM) and its intraseasonal oscillations (ISOs) by using a coupled ocean‐atmosphere regional climate model (CRSM) and an atmosphere‐only regional climate model (URSM). These 20‐km resolution regional climate models (RCMs) were driven by the boundary conditions from Community Climate System Model version 4 (CCSM4) global model. The mean ISM rainfall simulated by URSM and CRSM is comparable with observations and shows an improvement over the CCSM4. The systematic error in the spatial distribution of the mean June–September low‐level and upper‐level winds, sea surface temperature, and latent heat flux shows that CRSM performs better than URSM, suggesting the benefits of air‐sea coupling in the RCM simulations of the mean ISM. Both the CRSM and the URSM perform reasonably and comparably in capturing the spatiotemporal evolution of 10–20‐day high‐frequency and 20–70‐day low‐frequency ISOs of the ISM rainfall. These RCMs simulated the observed features of the ISO‐filtered rainfall anomalies that propagate at a faster rate across the Arabian Sea compared to that over the Bay of Bengal. Furthermore, the difference in the track density of the monsoon low‐pressure systems between the wet and the dry phases of ISOs shows insignificant differences between CRSM and URSM but is found to be superior to the CCSM4 simulation. This study suggests a relative insensitivity of air‐sea coupling in the RCM for simulating ISO and LPS features of ISM, which is likely abetted by the realistic ISO signals in the parent CCSM4.
Compositional Evolution of Polygenetic Fissure Volcanic Systems: Insights From the Latest Eruptions at Craters of the Moon Volcanic Field
Authors: Chadwick John , Chadwick Claire , Kamenov George
Published: April 2023

The Craters of the Moon (COM) Volcanic Field in Idaho is the largest mostly Holocene lava field in the conterminous U.S. and the site of the most recent volcanism in the Yellowstone‐Snake River Plain province. This prominent example of a polygenetic fissure field has produced over 60 eruptions over the past 15,000 years from the Great Rift fissure system. The eight most recent lava flows, known as Period A, were erupted between about 2,500 and 2,000 years ago. In this study, major and trace element and Pb‐Sr‐Nd isotope data were obtained, with several samples collected from each flow from widely spaced locations to evaluate heterogeneity in their source magmas. The results reveal three previously unrecognized compositional groups that may represent separate magma batches, and that assimilation and fractional crystallization (AFC) controlled the evolution of the entire Period A suite. The three oldest flows were periodic withdrawals from a body of highly evolved and poorly homogenized magma, and four later flows represent successive samplings from a stratified body of more primitive magma. These two flow groups are related via variable AFC modeled with Magma Chamber Simulator software, with Neogene rhyolite as a plausible crustal assimilant. A third compositional type that requires a different parent magma and AFC history is represented by a single flow erupted from vents a few km away from the others. The compositional evolution and variability observed in this sequence of flows provide new insights into how magmas are generated, modified, and delivered in such polygenetic fissure systems.
FWIGAN: Full‐Waveform Inversion via a Physics‐Informed Generative Adversarial Network
Authors: Yang Fangshu , Ma Jianwei
Published: April 2023

Full‐waveform inversion (FWI) is a powerful geophysical imaging technique that reproduces high‐resolution subsurface physical parameters by iteratively minimizing the misfit between the simulated and observed seismograms. Unfortunately, conventional FWI with a least‐squares loss function suffers from various drawbacks, such as the local‐minima problem and human intervention in the fine‐tuning of parameters. It is particular problematic when applied with noisy data and inadequate starting models. Recent work relying on partial differential equations and neural networks show promising performance in two‐dimensional FWI. Inspired by the competitive learning of generative adversarial networks, we propose an unsupervised learning paradigm that integrates the wave equation with a discriminative network to accurately estimate physically consistent velocity models in a distributional sense (FWIGAN). The introduced framework does not require a labeled training dataset or pretraining of the network; therefore, this framework is flexible and able to achieve inversion with minimal user interaction. We experimentally validate our method for three baseline geological models, and a comparison of the results demonstrates that FWIGAN faithfully recovers the velocity models and consistently outperforms other traditional or deep learning‐based algorithms. A further benefit from the physics‐constrained learning used in this method is that FWIGAN mitigates the local‐minima issue by reducing the sensitivity to initial models or data noise.
Aerosol Impacts on Storm Electrification and Lightning Discharges Under Different Thermodynamic Environments
Authors: Sun Mengyu , Qie Xiushu , Mansell Edward R. , Liu Dongxia , Yair Yoav , Fierro Alexandre O. , Yuan Shanfeng , Lu Jingyu
Published: April 2023

The impacts of aerosol and thermodynamics on electrification and lightning activities have been investigated in detail using the Weather Research and Forecasting Model coupled with a double‐moment microphysics parameterization and an explicit electrification lightning scheme. To obtain a varied combination of convective available potential energy (CAPE) values and aerosol concentrations, a sounding was modified consistently and initiated with five sets of aerosol concentrations that served as cloud condensation nuclei. The simulated electric processes respond to the varying dynamical and microphysical characteristics associated with the different CAPE and aerosol conditions. Under high CAPE circumstances, the augmentation of ice‐phase particle leads to the enhancement of non‐inductive charging primarily through the dynamic processes. Increased aerosol content further invigorates the electrification through microphysical processes. Elevated aerosol loading under low CAPE conditions increases cloud droplet and ice crystal numbers. Larger graupel particle size further leads to the enhanced electric intensity and lightning discharges.
Diverging Ozone Trends Above Western North America: Boundary Layer Decreases Versus Free Tropospheric Increases
Authors: Chang Kai‐Lan , Cooper Owen R. , Rodriguez Gavin , Iraci Laura T. , Yates Emma L. , Johnson Matthew S. , Gaudel Audrey , Jaffe Daniel A. , Bernays Noah , Clark Hannah , Effertz Peter , Leblanc Thierry , Petropavlovskikh Irina , Sauvage Bastien , Tarasick David W.
Published: April 2023

This study has produced an improved percentile and seasonal (median) trend estimate of free tropospheric ozone above western North America (WNA), through a data fusion of ozonesonde, lidar, commercial aircraft, and field campaign measurements. Our method combines heterogeneous data sets according to the consensus data characteristics and inherent uncertainty in order to produce our best fused product. In response to different data collection environments (in situ or ground‐based), we investigate the ozone variability based on a wide range of percentiles, which is preferable for trend detection due to tropospheric ozone's high degree of heteroscedasticity (i.e., inconsistent trends and variability between different ozone percentiles). We then compare the ozone trends and variability above the California sub‐domain to the full WNA region for better understanding of the correlations between different regional scales. In California, the 1995–2021 percentile (from the 5th to 95th) and seasonal trends are clearly positive in terms of high signal‐to‐noise ratios. The magnitude of the trends is generally weaker over WNA compared to California, but reliable positive trends can still be found between the 10th and 70th percentiles, as well as winter and summer, whereas autumn shows a negative trend over the same period. In addition, dozens of rural surface sites across the region are selected to represent the boundary layer variability. In contrast to increasing free tropospheric ozone, we find overall strong negative surface trends since 1995, with the greatest divergence found in summer. Throughout the analysis implications of the COVID‐19 economic downturn on ozone variability are discussed.
Moving Bedforms Control CO2 Production and Distribution in Sandy River Sediments
Authors: Schulz H. , Teitelbaum Y. , Lewandowski J. , Singer G. A. , Arnon S.
Published: April 2023

Streams and rivers play an important role in the global carbon cycle. The origins of CO2 in streams are often poorly constrained or neglected, which is especially true for CO2 originating from heterotrophic metabolism in streambeds. We hypothesized that sediment movement will have a direct effect on stream metabolism, and thus, the aim of this study was to quantify the effect of moving bedforms on the production of CO2 in sandy streambeds. We conducted flume experiments where we used planar optodes to measure the distributions of O2 and CO2 under various streambed celerities. We combined these measurements with an assessment of bed morphodynamics and modeling to calculate O2 consumption and CO2 production rates. Our results indicate that sediment transport can strongly influence streambed metabolism and CO2 production. We found that bedform celerity controls the shape of the hyporheic zone and exchange flux, and is directly linked to the spatial and temporal distributions of O2 and CO2. It was also found that the most pronounced change in CO2 production occurred when the bed changed from stationary conditions to a slowly moving bed. A more gradual increase in O2 consumption and CO2 production rates was observed with further increase in celerity. Our study also points out that bedform movement causes hydraulic isolation between the moving and the non‐moving fraction of the streambed that can lead to a transient storage of CO2 in deeper sediments, which may be released in bursts during bed scour.
Rare Event Simulation of Extreme European Winter Rainfall in an Intermediate Complexity Climate Model
Authors: Wouters Jeroen , Schiemann Reinhard K. H. , Shaffrey Len C.
Published: April 2023

We test the application of a rare event simulation (RES) algorithm to accelerate the sampling of extreme winter rainfall over Europe in a climate model. The genealogical particle analysis algorithm, an ensemble method that interrupts the simulation at intermediate times to clone realizations in which an extreme event is developing, is applied to the intermediate complexity general circulation model PlaSim. We show that the algorithm strongly reduces the numerical effort required to estimate probabilities of extremes, demonstrating the potential of RES of seasonal precipitation extremes.
Seasonal Variations of Soil Thermal Conductivity at the InSight Landing Site
Authors: Grott M. , Piqueux S. , Spohn T. , Knollenberg J. , Krause C. , Marteau E. , Hudson T. L. , Forget F. , Lange L. , Müller N. , Golombek M. , Nagihara S. , Morgan P. , Murphy J. P. , Siegler M. , King S. D. , Banfield D. , Smrekar S. E. , Banerdt W. B.
Published: April 2023

The heat flow and physical properties package measured soil thermal conductivity at the landing site in the 0.03–0.37 m depth range. Six measurements spanning solar longitudes from 8.0° to 210.0° were made and atmospheric pressure at the site was simultaneously measured using InSight's Pressure Sensor. We find that soil thermal conductivity strongly correlates with atmospheric pressure. This trend is compatible with predictions of the pressure dependence of thermal conductivity for unconsolidated soils under martian atmospheric conditions, indicating that heat transport through the pore filling gas is a major contributor to the total heat transport. Therefore, any cementation or induration of the soil sampled by the experiments must be minimal and soil surrounding the mole at depths below the duricrust is likely unconsolidated. Thermal conductivity data presented here are the first direct evidence that the atmosphere interacts with the top most meter of material on Mars.
Molecular architecture and gating mechanisms of the Drosophila TRPA1 channel
Authors: Wang Xiaofei , Li Yawen , Wei Hong , Yang Zhisen , Luo Rui , Gao Yongxiang , Zhang Wei , Liu Xin , Sun Linfeng
Published: April 2023

The transient receptor potential channel subfamily A member 1 (TRPA1) ion channel is an evolutionary conserved polymodal sensor responding to noxious temperature or chemical stimuli. Notably, the thermosensitivity of TRPA1 varies among different species or even different isoforms in the same species. However, the underlying molecular basis of its thermo-gating remains largely unknown. Here, we determine the structures of a heat-sensitive isoform of TRPA1 inDrosophila melanogasterin two distinct conformations with cryo-samples prepared at 8 °C. Large conformational changes are observed in the ankyrin repeat domain (ARD) and the coiled-coil domain between the two states. Remarkably, all 17 ankyrin repeats are mapped in the newly resolved conformation, forming a propeller-like architecture. Two intersubunit interfaces are identified in the amino (N)-terminal domain, and play vital roles during both heat and chemical activation as shown by electrophysiological analysis. With cryo-samples prepared at 35 °C, only one conformation is resolved, suggesting possible state transitions during heat responses. These findings provide a basis for further understanding how the ARD regulates channel functions, and insights into the gating mechanism of TRPA1.
Deciphering the genetic structure of the Quebec founder population using genealogies
Authors: Gagnon Laurence , Moreau Claudia , Laprise Catherine , Vézina Hélène , Girard Simon L.
Published: April 2023

Using genealogy to study the demographic history of a population makes it possible to overcome the models and assumptions often used in population genetics. The Quebec founder population is one of the few populations in the world having access to the complete genealogy of the last 400 years. The goal of this study is to follow the evolution of the Quebec population structure over time from the beginning of European colonization until the present day. To do so, we calculated the kinship coefficients of all ancestors’ pairs in the ascending genealogy of 665 subjects from eight regional and ethnocultural groups per 25-year period. We show that the Quebec population structure appeared progressively in the St. Lawrence valley as early as 1750 with the distinction of the Saguenay and Gaspesian groups. At that time, the ancestors of two groups, the Sagueneans and the Acadians from the Gaspé Peninsula, experienced a marked increase in kinship and inbreeding levels which have shaped the structure and led to the contemporary population structure. Interestingly, this structure arose before the colonization of the Saguenay region and at the very beginning of the Gaspé Peninsula settlement. The resulting regional founder effects in these groups led to differences in the present-day identity-by-descent sharing, the Gaspé and North Shore groups sharing more large segments and the Sagueneans more short segments. This is also reflected by the distribution of the number of most recent common ancestors at different generations and their genetic contribution to the studied subjects.
Signature of spin-triplet exciton condensations in LaCoO3 at ultrahigh magnetic fields up to 600 T
Authors: Ikeda Akihiko , Matsuda Yasuhiro H. , Sato Keisuke , Ishii Yuto , Sawabe Hironobu , Nakamura Daisuke , Takeyama Shojiro , Nasu Joji
Published: April 2023

Bose-Einstein condensation of electron-hole pairs, exciton condensation, has been effortfully investigated since predicted 60 years ago. Irrefutable evidence has still been lacking due to experimental difficulties in verifying the condensation of the charge neutral and non-magnetic spin-singlet excitons. Whilst, condensation of spin-triplet excitons is a promising frontier because spin supercurrent and spin-Seebeck effects will be observable. A canonical cobaltite LaCoO3 under very high magnetic fields is a propitious candidate, yet to be verified. Here, we unveil the exotic phase diagram of LaCoO3 up to 600 T generated using the electromagnetic flux compression method and the state-of-the-art magnetostriction gauge. We found the continuous magnetostriction curves and a bending structure, which suggest the emergence of two distinct spin-triplet exciton condensates. By constructing a phenomenological model, we showed that quantum fluctuations of excitons are crucial for the field-induced successive transitions. The spin-triplet exciton condensation in a cobaltite, which is three-dimensional and thermally equilibrated, opens up a novel venue for spintronics technologies with spin-supercurrent such as a spin Josephson junction.
Unselfish traits and social decision-making patterns characterize six populations of real-world extraordinary altruists
Authors: Rhoads Shawn A. , Vekaria Kruti M. , O’Connell Katherine , Elizabeth Hannah S. , Rand David G. , Kozak Williams Megan N. , Marsh Abigail A.
Published: April 2023

Acts of extraordinary, costly altruism, in which significant risks or costs are assumed to benefit strangers, have long represented a motivational puzzle. But the features that consistently distinguish individuals who engage in such acts have not been identified. We assess six groups of real-world extraordinary altruists who had performed costly or risky and normatively rare (<0.00005% per capita) altruistic acts: heroic rescues, non-directed and directed kidney donations, liver donations, marrow or hematopoietic stem cell donations, and humanitarian aid work. Here, we show that the features that best distinguish altruists from controls are traits and decision-making patterns indicating unusually high valuation of others’ outcomes: high Honesty-Humility, reduced Social Discounting, and reduced Personal Distress. Two independent samples of adults who were asked what traits would characterize altruists failed to predict this pattern. These findings suggest that theories regarding self-focused motivations for altruism (e.g., self-enhancing reciprocity, reputation enhancement) alone are insufficient explanations for acts of real-world self-sacrifice.
Age-dependent Pdgfrβ signaling drives adipocyte progenitor dysfunction to alter the beige adipogenic niche in male mice
Authors: Benvie Abigail M. , Lee Derek , Steiner Benjamin M. , Xue Siwen , Jiang Yuwei , Berry Daniel C.
Published: April 2023

Perivascular adipocyte progenitor cells (APCs) can generate cold temperature-induced thermogenic beige adipocytes within white adipose tissue (WAT), an effect that could counteract excess fat mass and metabolic pathologies. Yet, the ability to generate beige adipocytes declines with age, creating a key challenge for their therapeutic potential. Here we show that ageing beige APCs overexpress platelet derived growth factor receptor beta (Pdgfrβ) to prevent beige adipogenesis. We show that genetically deletingPdgfrβ, in adult male mice, restores beige adipocyte generation whereas activatingPdgfrβin juvenile mice blocks beige fat formation. Mechanistically, we find that Stat1 phosphorylation mediates Pdgfrβ beige APC signaling to suppressIL-33induction, which dampens immunological genes such asIL-13andIL-5. Moreover, pharmacologically targeting Pdgfrβ signaling restores beige adipocyte development by rejuvenating the immunological niche. Thus, targeting Pdgfrβ signaling could be a strategy to restore WAT immune cell function to stimulate beige fat in adult mammals.
Light-driven peristaltic pumping by an actuating splay-bend strip
Authors: Dradrach Klaudia , Zmyślony Michał , Deng Zixuan , Priimagi Arri , Biggins John , Wasylczyk Piotr
Published: April 2023

Despite spectacular progress in microfluidics, small-scale liquid manipulation, with few exceptions, is still driven by external pumps and controlled by large-scale valves, increasing cost and size and limiting complexity. By contrast, optofluidics uses light to power, control and monitor liquid manipulation, potentially allowing for small, self-contained microfluidic devices. Here we demonstrate a soft light-propelled actuator made of liquid crystal gel that pumps microlitre volumes of water. The strip of actuating material serves as both a pump and a channel leading to an extremely simple microfluidic architecture that is both powered and controlled by light. The performance of the pump is well explained by a simple theoretical model in which the light-induced bending of the actuator competes with the liquid’s surface tension. The theory highlights that effective pumping requires a threshold light intensity and strip width. The proposed system explores the benefits of shifting the complexity of microfluidic systems from the fabricated device to spatio-temporal control over stimulating light patterns.