bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mis‐conceptualisation of Societal Impact: Why the Swiss Approach to Societal Impact is Productive and not Inexistent
Authors: Ochsner Michael
Published: August 2024

Societal impact as a buzz word is high on the agenda of policy‐makers around the world. Often, the UK Research Excellence Framework (REF) is cited as the initiator of making the societal impact of research relevant and visible. Equally often, it is said that in Switzerland societal impact is not yet considered in higher education policy. In this paper, I show that both claims are as wrong as they are common. I argue that the UK REF's “impact agenda” is strongly linked to a specific ideology and does not represent the only approach to valorizing and fostering the research‐society nexus. By pointing out some major issues in impact evaluation and presenting how the research‐society nexus is discussed in Swiss science policy as a contrasting case, I sketch an approach to impact evaluation based on the role of research in society that considers different forms of knowledge generation and dissemination.
Adipose‐derived stem cells transplantation improves survival and alleviates contraction of skin grafts via promoting macrophages M2 polarization
Authors: Cui Yuying , He Jiahao , Yu Zheyuan , Zhou Sizheng , Cao Dejun , Jiang Taoran , Fang Bin , Li Guangshuai
Published: August 2024

Background

Full‐thickness skin grafts are widely used in plastic and reconstructive surgery. The main limitation of skin grafting is the poor textural durability and associated contracture, which often needs further corrective surgery. Excessive inflammation is the main reason for skin graft contractions, which involve overactivation of myofibroblasts. These problems have prompted the development of new therapeutic approaches, including macrophage polarization modulation and stem cell–based therapies. Currently, adipose‐derived stem cells (ASCs) have shown promise in promoting skin grafts survival and regulating macrophage phenotypes. However, the roles of ASCs on macrophages in decreasing skin grafts contraction remain unknown.

Materials and Methods

Rat adipose‐derived stem cells (rASCs) were isolated from rat inguinal adipose tissues. Full‐thickness skin graft model was constructed on male rats divided into control group and rASCs treatment group. Skin graft was assessed for concentration, elasticity modulus and stiffness. Rat bone marrow‐derived macrophages (rBMDMs) were isolated from rat femurs, and subsequent RT‐qPCR and coculture assays were carried out to explore the cellular mechanisms. Immunohistochemical and immunofluorescence staining were used to verify mechanisms in vivo.

Results

In vivo results showed that after injection of ASCs, improved texture, increased survival and inhibited contraction of skin grafts were seen. Vascularization was also improved as illustrated by laser perfusion image and vascular endothelial growth factor (VEGF) concentration. Histological analysis revealed that ASCs injection significantly reduced expression of pro‐inflammatory cytokines (TNF‐a, IL‐1β) and increased expression of anti‐inflammatory (IL‐10) and pro‐healing cytokines (IGF‐1). At cellular level, after co‐culturing with rASCs, rat bone marrow derived macrophages (rBMDMs) favored M2 polarization even under inflammatory stimulus.

Conclusion

ASCs treatment enhanced vascularization via angiogenic cytokines secretion and alleviated inflammatory environment in skin grafts by driving M2 macrophages polarization, which improved survival and decreased skin grafts contraction. Our work showed that ASCs transplantation can be harnessed to enhance therapeutic efficacy of skin grafting in cutaneous defects treatment.
Introduction of the donor centre virtual crossmatch in Eurotransplant
Authors: Heidt Sebastiaan , Kramer Cynthia S. M. , Haasnoot Geert W. , Schmidt Alexander H. , Zoet Yvonne M. , Claas Frans H. J. , Vogelaar Serge
Published: August 2024

On 24 January 2023, Eurotransplant has introduced the virtual crossmatch for kidney and pancreas allocation as a better alternative for the physical Complement Dependent Cytotoxicity (CDC) crossmatches at the donor centre, which were associated with a longer cold ischaemia time and false positive reactions. For the time being, the physical CDC crossmatch at the recipient centre will remain in place as the final histocompatibility check. While Eurotransplant is certainly not the first organ allocation organisation to introduce virtual crossmatching, several novel aspects have been introduced, such as calculation of the virtual panel reactive antibody (vPRA) on 11 loci at the second‐field level in addition to the serological broad and split level, electronic HLA typing data transmission using Histoimmunogenetics Markup Language (HML) file format, and the actual virtual crossmatch based on ambiguous, second‐field HLA typing of the donor on all 11 loci. This short communication will focus on these novel aspects of the virtual crossmatch in Eurotransplant.
BAPID suppresses the inhibition of BRM on Di19‐PR module in response to drought
Authors: Liu Nian , Hu Zhiyong , Zhang Liang , Yang Qian , Deng Linbin , Terzaghi William , Hua Wei , Yan Mingli , Liu Jing , Zheng Ming
Published: August 2024

Drought is one of the most important abiotic stresses, and seriously threatens plant development and productivity. Increasing evidence indicates that chromatin remodelers are pivotal for plant drought response. However, molecular mechanisms of chromatin remodelers‐mediated plant drought responses remain obscure. In this study, we found a novel interactor of BRM called BRM‐associated protein involved in drought response (BAPID), which interacted with SWI/SNF chromatin remodeler BRM and drought‐induced transcription factor Di19. Our findings demonstrated that BAPID acted as a positive drought regulator since drought tolerance was increased in BAPID‐overexpressing plants, but decreased in BAPID‐deficient plants, and physically bound to PR1, PR2, and PR5 promoters to mediate expression of PR genes to defend against dehydration stress. Genetic approaches demonstrated that BRM acted epistatically to BAPID and Di19 in drought response in Arabidopsis. Furthermore, the BAPID protein‐inhibited interaction between BRM and Di19, and suppressed the inhibition of BRM on the Di19‐PR module by mediating the H3K27me3 deposition at PR loci, thus changing nucleosome accessibility of Di19 and activating transcription of PR genes in response to drought. Our results shed light on the molecular mechanism whereby the BAPID‐BRM‐Di19‐PRs pathway mediates plant drought responses. We provide data improving our understanding of chromatin remodeler‐mediated plant drought regulation network.
Herbarium specimens as tools for exploring the evolution of fatty acid‐derived natural products in plants
Authors: Fitzgibbons Emma , Lastovich Jacob , Scott Samuel , Groth Nicole , Grusz Amanda L. , Busta Lucas
Published: August 2024

Plants synthesize natural products via lineage‐specific offshoots of their core metabolic pathways, including fatty acid synthesis. Recent studies have shed light on new fatty acid‐derived natural products and their biosynthetic pathways in disparate plant species. Inspired by this progress, we set out to develop tools for exploring the evolution of fatty‐acid derived products. We sampled multiple species from all major clades of euphyllophytes, including ferns, gymnosperms, and angiosperms (monocots and eudicots), and we show that the compositional profiles (though not necessarily the total amounts) of fatty‐acid derived surface waxes from preserved plant specimens are consistent with those obtained from freshly collected tissue in a semi‐quantitative and sometimes quantitative manner. We then sampled herbarium specimens representing 57 monocot species to assess the phylogenetic distribution and evolution, of two fatty acid‐derived natural products found in that clade: beta‐diketones and alkylresorcinols. These chemical data, combined with analyses of 26 monocot genomes, revealed a co‐occurrence (though not necessarily a causal relationship) between whole genome duplication and the evolution of diketone synthases from an ancestral alkylresorcinol synthase‐like polyketide synthase. Limitations of using herbarium specimen wax profiles as proxies for those of fresh tissue seem likely to include effects from loss of epicuticular wax crystals, effects from preservation techniques, and variation in wax chemical profiles due to genotype or environment. Nevertheless, this work reinforces the widespread utility of herbarium specimens for studying leaf surface waxes (and possibly other chemical classes) and reveals some of the evolutionary history of fatty acid‐derived natural products within monocots.
RhMYC2 controls petal size through synergistic regulation of jasmonic acid and cytokinin signaling in rose
Authors: Gong Feifei , Jing Weikun , Jin Weichan , Liu Huwei , Zhang Yuanfei , Wang Rui , Wei Yinghao , Tang Kaiyang , Jiang Yunhe , Gao Junping , Sun Xiaoming
Published: August 2024

Petal size is determined by cell division and cell expansion. Jasmonic acid (JA) has been reported to be associated with floral development, but its regulatory mechanism affecting petal size remains unclear. Here, we reveal the vital role of JA in regulating petal size and the duration of the cell division phase via the key JA signaling component RhMYC2. We show that RhMYC2 expression is induced by exogenous treatment with methyl jasmonate and decreases from stage 0 to stage 2 of flower organ development, corresponding to the cell division phase. Furthermore, silencing RhMYC2 shortened the duration of the cell division phase, ultimately accelerating flowering opening and resulting in smaller petals. In addition, we determined that RhMYC2 controls cytokinin homeostasis in rose petals by directly activating the expression of the cytokinin biosynthetic gene LONELY GUY3 (RhLOG3) and repressing that of the cytokinin catabolism gene CYTOKININ OXIDASE/DEHYDROGENASE6 (RhCKX6). Silencing RhLOG3 shortened the duration of the cell division period and produced smaller petals, similar to RhMYC2 silencing. Our results underscore the synergistic effects of JA and cytokinin in regulating floral development, especially for petal size in roses.
The gap phenomenon for conformally related Einstein metrics
Authors: Šilhan Josef , Gregorovič Jan
Published: August 2024

We determine the submaximal dimensions of the spaces of almost Einstein scales and normal conformal Killing fields for connected conformal manifolds. The results depend on the signature and dimension of the conformally nonflat conformal manifold. In definite signature, these two dimensions are at most and , respectively. In Lorentzian signature, these two dimensions are at most and , respectively. In the remaining signatures, these two dimensions are at most and , respectively. This upper bound is sharp and to realize examples of submaximal dimensions, we first provide them directly in dimension 4. In higher dimensions, we construct the submaximal examples as the (warped) product of the (pseudo)‐Euclidean base of dimension with one of the 4‐dimensional submaximal examples.
The effect of female breast surface area on skin stiffness and tactile sensitivity at rest and following exercise in the heat
Authors: Blount Hannah , Valenza Alessandro , Ward Jade , Caggiari Silvia , Worsley Peter R. , Filingeri Davide
Published: August 2024

Female development includes significant morphological changes across the breast. Yet, whether differences in breast surface area (BrSA) modify breast skin stiffness and tactile sensitivity at rest and after exercise in the heat remain unclear. We investigated the relationship between BrSA and skin stiffness and tactile sensitivity in 20 young to middle‐aged women (27 ± 8 years of age) of varying breast sizes (BrSA range: 147–502 cm2) at rest and after a submaximal run in a warm climatic chamber (32 ±  53% ± 1.7% relative humidity). Skin stiffness above and below the nipple and tactile sensitivity from the nipple down were measured. Associations between BrSA and both skin stiffness and tactile sensitivity at rest were determined via correlation analyses. Effects of exercise and test site were assessed by a two‐way ANOVA. Skin stiffness was positively correlated with BrSA 3 cm above the areola edge (r = 0.61, P = 0.005) and at the superior areola border (r = 0.54, P = 0.016), but not below the nipple (P > 0.05). The area 3 cm below the areola was also significantly stiffer than all other test sites (P < 0.043). Tactile sensitivity did not vary with BrSA (P > 0.09), but it varied across the breast (i.e., the area 3 cm below the areola was more sensitive than the inferior areola edge; P = 0.018). Skin stiffness and tactile sensitivity across the breast decreased after exercise by ∼37% (P < 0.001) and ∼45% (P = 0.008), respectively. These findings expand our fundamental understanding of the mechanosensory properties of the female breast, and they could help to inform sportswear innovation to better meet the support needs of women of different breast sizes at rest and following exercise.
Does Export-led Growth Still Work for the South Korean Economy? Before and After the 1997/98 Asian Crisis
Authors: Jin Jang C.
Published: August 2024

The export-led growth hypothesis has been examined for South Korea, which has long been regarded as a typical export-oriented economy. In particular, the expansion of exports in South Korea is reinforced by the imports of raw materials and intermediate goods from overseas, and the exports of manufactured final goods increase at a greater rate than the import growth. In this case, net exports rise. One striking result we have found is that for the earlier sample period of 1972-1996 prior to the 1997/98 Asian crisis, changes in net exports had a significant impact on economic growth; but the growth effect of net exports has been mitigated and insignificant for the recent years of 1999-2017. The two contrasting results we have found reflect the structural changes experienced by the South Korean economy after the 1997/98 economic crisis.
Film Superposition Characteristics With Laidback Fan-Shaped Holes Under the Influence of Internal Crossflow
Authors: Haoyang Liu , Qiang Du , Qingzong Xu , Jiawei Xu , Guangyao Xu , Hongye Li , Pengfei Wang
Published: August 2024

In the serpentine passage of actual rotor blades, the coolant at the inlet of the film hole has an internal crossflow. The internal crossflow significantly influences the film cooling effectiveness of multi-row film holes. This paper presents a numerical investigation of the superposition characteristics of multiple rows of laidback fan-shaped holes under the influence of internal crossflow. The numerical simulations utilize the RANS method considering the effects of blowing ratio, crossflow velocity ratio, arrangement patterns, and row-to-row spacing of the internal crossflow on the superposition characteristics of film holes. The results indicate that film cooling effectiveness exhibits a distinctly asymmetric distribution under crossflow conditions. At different blowing ratios, there exists an optimal crossflow velocity ratio, at which the laterally averaged film cooling effectiveness is maximized. The crossflow-to-jet velocity ratio (VRi) is utilized to comprehensively evaluate the impact of blowing ratios and crossflow velocity ratios, and the range of high area-averaged film cooling effectiveness is accurately captured. Regarding the study of arrangement patterns and row-to-row spacings, it has been found that under identical coolant mass flowrates, the staggered arrangement is better than the inline arrangement in both laterally averaged film cooling effectiveness and cooling uniformity. Meanwhile, reducing the row-to-row spacing leads to an improvement in laterally averaged film cooling effectiveness. Finally, an assessment of the Sellers model's applicability under crossflow conditions revealed that it demonstrates good applicability in cases of staggered arrangement with lower blowing ratios.
Performance Analysis of a Self-Decarbonizing Combustor
Authors: Akojwar Kartikeya S. , Pawar Samadhan A. , Chaudhuri Swetaprovo
Published: August 2024

Hydrogen is envisioned to be a key decarbonization solution for fossil fuel-dependent power generation and aviation industries. At present, a significant fraction of the generated electrical power is derived from natural gas. As such, the external energy needed for hydrogen generation, often sourced from fossil fuels, results in CO2 emissions, compromising overall carbon neutrality. Instead, the processes of hydrogen generation can be energetically coupled with the combustion process, in situ, to eliminate external energy requirements. To that end, a novel self-decarbonizing combustor (SDC) has been conceptualized, integrating methane pyrolysis with the combustion process that can in principle decarbonize many contemporary power generation technologies. The underpinning methane pyrolysis process enables in situ pre-combustion capture of solid carbon, while simultaneously generating hydrogen. Consequently, CO2 emissions resulting from the combustion of processed, hydrogen-enriched fuel are mitigated. This study provides a comprehensive analysis, delineating the operating principle and the effect of some of the important governing parameters on the performance of the self-decarbonizing combustor. These parameters, including fuel temperature, residence time, pressure, and catalysis, are studied in the context of potentially applying the proposed concept to natural gas-based decarbonized electrical power generation. Investigating fuel chemistry, combustion exhaust, and carbon structure and morphology under varying process parameters enhances our comprehension of the SDC. Additionally, its self-sufficient nature eliminates the need for separate hydrogen production, storage, and transportation infrastructure, highlighting its potential as a scalable and realizable technology.
Analysis and Optimization of the Fatigue Damage Accumulation Under Transient Vibrations of Mistuned Bladed Disks
Authors: Jing Tong , Zang Chaoping , Petrov Evgeny
Published: August 2024

This paper develops an efficient method for calculations of stress levels, accumulation of high-cycle fatigue (HCF), and mistuning optimization aimed at the reduction of the fatigue damages for mistuned bladed disks under transient vibrations caused by variation of the rotation speed in the vicinity of resonance frequencies. The expressions for the sensitivities of the stress intensity at critical locations, and fatigue damage at loading cycles concerning the mistuning are derived analytically, providing high accuracy and speed of their evaluations. A gradient-based optimization method based on the sensitivities is applied to find the blade mistuning patterns, providing the minimum and maximum fatigue damage accumulated during gas-turbine acceleration or deceleration of a mistuned bladed disk for extending the service life. The method uses realistic large-scale finite element (FE) modeling for bladed disks, accounting for the varying damping and excitation loads with amplitude and frequency spectrum changing with rotation speed. The method has been implemented in a computer code. The fatigue accumulation caused by the transient vibration has been studied using a realistic bladed disk model. The gradient-based optimization search for mistuning patterns, providing the minimum and maximum fatigue damage accumulation during rotor acceleration is performed.
Evaluation of Mechanical and Thermomechanical Water Vapor Compression Techniques for Enabling High Temperature Lift Hydration-Based Chemical Heat Pumps
Authors: Armatis Paul D. , Sabharwall Piyush , Fronk Brian M.
Published: August 2024

Achieving high temperature lifts (>200K) via a chemical heat pump based on salt hydration/dehydration reactions requires the transport of water vapor from low to high pressure. Alternative compression approaches require condensing of low-pressure water vapor, pumping of liquid water, and subsequent evaporation when the low-side pressure corresponds to sub-ambient water saturation temperatures. Thus, this study compares four steam compression methods for use within a chemical heat pump system based on a reversible calcium oxide hydration/dehydration reaction with a temperature lift from 350∘C heat to >600∘C. Purely mechanical and thermochemical/mechanical compression technologies are considered. A parametric study of maximum allowable temperature, the isentropic efficiency of mechanical compressors, the effectiveness of heat exchangers, and the assumed allowable heat exchanger pressure drop is conducted to determine the mechanical and thermal energy consumed per kilogram of compressed steam. The system complexity in terms of the number of main system components, maximum pressure ratio, and maximum allowable temperature is estimated. Model results show an absorption-based steam compressor has the highest exergetic efficiency for the required chemical heat pump conditions. This system configuration was then experimentally demonstrated to illustrate the impact of system performance on component effectiveness.
Comparing the Cavitation and Slurry Erosion Wear Resistance of 16Cr-5Ni Stainless Steel With 13Cr-4Ni CA6NM Stainless Steel
Authors: Muñoz-Cubillos J. , Zambrano O. A. , Coronado J. J. , Rodríguez S. A.
Published: August 2024

In the current work, 16Cr-5Ni stainless martensitic cast steel was evaluated in cavitation and slurry erosion tests under different thermal aging treatments (TATs) using an ultrasonic vibratory cavitation apparatus and an in-house-designed jet slurry tribometer. The steel was homogenized at 1100 °C for 40 h and then thermal ageing was performed at 475 °C, 550 °C, and 625 °C for 4 h. The cavitation test results showed a lower wear-rate was obtained under TAT at 475 °C, followed by TAT at 550 °C, and a higher wear-rate was found under TAT at 625 °C. A good correlation was established between hardness and the maximum erosion rate in the cavitation results. In the slurry tests, the jet stream contained a fixed mass fraction of 1.25 wt% sand. The evaluated impingement angles were 45 deg and 90 deg, and better performance was obtained under TAT at 475 °C and TAT at 550 °C. The results for the thermal aging of 16Cr-5Ni were compared with those of traditional CA6NM (13Cr-4Ni) steel, which is widely used in the manufacturing of turbine runners. Under every condition evaluated, 16Cr-5Ni presented a cavitation erosion resistance value higher than that of CA6NM, and the slurry erosion resistance of both steels was very similar when 16Cr-5Ni under TAT at 475 °C or 550 °C was compared with CA6NM. Therefore, 16Cr-5Ni stainless martensitic cast steel could be another alternative to the promising results obtained for the manufacturing of turbine runners.
Interpretation of complex x-ray photoelectron peak shapes. I. Case study of Fe 2p3/2 spectra
Authors: Hughes A. E. , Easton C. D. , Gengenbach T. R. , Biesinger M. C. , Laleh M.
Published: August 2024

Analyzing transition metal XPS peaks is widely used to determine surface composition and chemistry. However, these peaks have a complex structure, which is still the subject of investigation. Fe 2p analysis is a case in point where the multiplet structure and many-electron-effects lead to peak shapes that cannot be analyzed using standard approaches. Examination of the literature reveals that one of the most widely used approaches to data reduction when processing Fe 2p3/2 spectra involves using symmetric two- or three-component peak fitting with each peak effectively acting to capture a single chemical species (chemistry fit) in the complex spectra. Herein, this approach is compared to an envelope fit approach using Biesinger multiplet components of known iron oxides to determine how effective these methods are in reproducing iron oxide composition. Mixed oxide and metal XPS Fe 2p spectra were synthesized using reference spectra collected experimentally. For the first time, the accuracy and differences between the two approaches are reported. It is demonstrated that no meaningful conclusions can be drawn using single symmetric peaks to analyze complex Fe 2p3/2 spectra, implying that a large portion of the literature is flawed. The envelope fit approach, however, is shown to provide useful information regarding oxide ratios in mixed iron oxide materials, though limitations do exist. A methodology for evaluating the quality of XPS analysis of Fe 2p3/2 spectra is proposed for benchmarking new submissions so that reviewers, authors, and editors can assess these submissions.
Sputter-deposited zirconium doped nickel-aluminide coatings for high-temperature oxidation-resistant applications
Authors: Tiwari Sunil Kumar , Rao Akula Umamaheswara , Kharb Archana Singh , Verma Piyush Chandra , Dubey Paritosh , Chawla Vipin , Sardana Neha , Kumar Sanjeev , Avasthi Devesh Kumar , Chawla Amit Kumar
Published: August 2024

Zr-Ni3Al coatings were deposited over the Inconel-718 substrate using DC cosputtering. The deposition was carried out in a custom-designed chamber at a substrate temperature of 400 °C. The evolution of phases, microstructure, surface topography, and elemental composition were characterized using x-ray diffraction, field emission scanning electron microscopy (FESEM), atomic force microscopy, and energy dispersive spectroscopy (EDS), respectively, whereas the adhesion strength and the mechanical properties of the coatings were characterized using nanoindentation. The oxidation properties of the coatings were studied at 900, 1000, and 1100 °C in open air to determine the kinetics of oxidations. The results reveal that with the increase in Zr concentration in the host Ni3Al matrix, the adhesive strength and mechanical properties of the films increase. The highest hardness and Young’s modulus of ∼9.2 and ∼150.3 GPa, respectively, are observed for 30 W Zr-Ni3Al coatings. Additionally, 1.51 at. % of Zr in Ni3Al coatings has shown the best oxidation resistance properties at all temperatures. However, an increase in the rate of oxidation has been observed with an increase in exposure temperature. The formation of different oxide layers after oxidation has been elucidated using FESEM and EDS after looking into the surface morphologies of the oxidized coatings.
Understanding exotic black hole orbits using effective potentials
Authors: Pakiela Steven , Bolen Brett , Holder Benjamin P. , Rizzo Monica , Larson Shane L.
Published: August 2024

Strongly gravitating systems can undergo unusual orbital trajectories. For example, “extreme mass ratio inspirals” (observable in the megahertz band by space-based gravitational wave detectors) can exhibit “zoom-whirl” orbits, which make complicated waveforms that are useful for mapping out the system's gravitational structure. Zoom-whirl behavior can be intuitively understood in the context of effective potentials, which should be familiar to students from classical orbital theory in mechanics. Here, we explore zoom-whirl orbits using effective potential theory around Schwarzschild black holes and present an interactive tool that can be used in pedagogical settings.
Remarks on the yield of fission bombs
Authors: Pearson J. M. , Cameron Reed B.
Published: August 2024

We discuss the apparent paradox that the energy released in a fission bomb explosion is independent of the energy ϵ liberated by each fissioning nucleus. The paradox is resolved by noting that a larger value of ϵ results in a shorter “burn time”; this stops the chain reaction sooner and results in fewer nuclei being fissioned.
Application of the heat equation to the study of underground temperature
Authors: Caprais Mathis , Shviro Oriane , Pensec Ugo , Zeyen Hermann
Published: August 2024

Modeling underground temperatures provides a practical application of the one-dimensional heat equation. In this work, the one-dimensional heat equation in surface soil is extended to include heat carried by the vertical flow of rainwater through the soil. Analytical solutions, with and without water flow, illustrate the influence of rainwater circulation on the sub-surface propagation of seasonal temperature variations, an important effect that is generally neglected in textbooks. The surface temperature variations are damped by the soil, and this effect was used by the Troglodytae in Egypt or the Petra in South Jordan to insulate against extreme temperatures. For a realistic case of horizontally layered geology, a finite volume Python code was developed for the same purpose. Subsurface temperatures were also measured over a full year at depths up to 1.8 m and used to estimate the thermal skin depth and thermal wavelength. This study provides students with a practical example of how a textbook physics problem can be modified to extract information of contemporary importance in geophysics and global warming.
Comment on “Which is greater: eπ or πe? An unorthodox physical solution to a classic puzzle” [Am. J. Phys. 92(5), 397–398 (2024)]
Authors: Macrae Roderick M.
Published: August 2024

Editor's Note: In a recent paper [Am. J. Phys. 92(5) 397–398 (2024)], Vallejo and Bove used the second law of thermodynamics to show that eπ > πe by imagining a finite body of initial temperature π placed in contact with a reservoir at temperature e. This comment on that work explores the situation more generally, showing that the result depends upon neither the value of π or the second law. Rather, Vallejo and Bove's result is a limited proof of the second law in the case of their particular example. Appropriate for thermodynamics students at all levels.
Analytical solution for acoustic radiation force and torque on a spheroid near a rigid or free planar boundary
Authors: Simon Blake E. , Hamilton Mark F.
Published: August 2024

An analytical solution is developed for the acoustic radiation force and torque caused by an arbitrary sound field that is incident on a compressible spheroid of any size near a planar boundary that is either rigid or pressure release. The analysis is an extension of a recent solution for a compressible sphere near a planar boundary [Simon and Hamilton, J. Acoust. Soc. Am. 153, 627–642 (2023)]. Approximations that account for a boundary formed by a two-fluid interface may be incorporated as in the previous analysis for a sphere. The present solution is based on expansions of the total acoustic pressure field in spheroidal wave functions and the use of addition theorems. Verification of the solution is accomplished by comparison with a finite element model. Examples are presented for incident fields that are either plane or spherical waves. Effects resulting from the presence of the boundary are studied by comparing the full theory with a simplified model in which multiple scattering is neglected. Numerical implementation of the proposed solution is also discussed.
The Evolvement of Session Design From Junior Age to Senior Peak Performance in World-Class Cross-Country Skiers
Authors: Walther Jacob , Haugen Thomas , Solli Guro Strøm , Tønnessen Espen , Sandbakk Øyvind
Published: August 2024

Purpose: To compare designs of training sessions applied by world-class cross-country skiers during their most successful junior and senior season. Methods: Retrospective analysis of self-reported training characteristics (ie, training form, intensity, and exercise mode) among 8 male and 7 female world-class cross-country skiers was conducted. Results: Total number of sessions (441 [71] vs 519 [34], P < .001, large effect) and mean duration (1.5 [0.1] h vs 1.7 [0.1] h, P < .001, moderate effect) increased from junior to senior age. More double-session days were performed at senior age (124 [50] vs 197 [29] d, P < .001, large). The number (310 [64] vs 393 [64], P < .001, large effect) and duration (1.3 [0.1] h vs 1.5 [0.1] h, P < .001, moderate effect) of low-intensity training sessions increased from junior to senior age. Regarding intensive training, most emphasis was put on high-intensity training sessions lasting 20 to 39 minutes with <5-minute intervals at junior age, while 40 to 59 minutes of moderate-intensity training with 5- to 9-minute intervals was predominant at senior age. More MIXED (combined moderate- and high-intensity) sessions (9 [7] vs 14 [7], P = .023, moderate effect) and longer races (0.5 [0.1] h vs 0.6 [0.1] h, P = 0.29, moderate effect) compensated for fewer high-intensity training sessions at senior age (36 [17] vs 25 [10], P = .027, moderate effect). Duration of strength-training sessions increased significantly (0.6 [0.1] vs 0.8 [0.2] h, P = 0.30, moderate effect), while other training forms remained unchanged. Conclusions: World-class cross-country skiers increased their training volume from junior to senior age primarily by more and longer low-intensity training sessions and more often training twice per day. Concurrently, the most frequent intensive sessions were modified from high- to moderate-intensity training, lasted longer, and contained longer intervals.
Sports Participation During Adolescence and Menstrual Cycle Education Status in Females Across Six Territories
Authors: Law Phoebe , Brown Natalie , Pedlar Charles , Bruinvels Georgie
Published: August 2024

Introduction: There is a substantial amount of sporting dropout in teenage girls worldwide linked, in part, to the menstrual cycle (MC). Firstly, this study aimed to retrospectively quantify the reasons for decreased sport and, or, exercise (sports/exercise) participation during adolescence across different countries. Secondly, this study investigated the prevalence, source, and content of MC education received in relation to sports/exercise. Methods: A survey was distributed via the Strava app to six geographical territories. The survey captured retrospective reasons for changing sports/exercise participation levels during adolescence and the provision, content, and source of MC education received in relation to sports/exercise. Descriptive statistics were reported as frequencies and associations between countries, education, and adolescent participation levels were determined using chi-square analysis (p = .01). Results: Female Strava users (M = 40.8 years, SD = 10.7 years) from six territories completed the survey (n = 10,371). 24.8% of participants decreased their sports/exercise participation during adolescence with the United Kingdom and Ireland (39.7%) and Spain (39.1%) reporting significantly higher decreases than the other countries surveyed, χ2(10)=1,023.77, p ≤ .001. The most common reason for decreased participation was a lack of time (28.0%). 71.1% of participants had not received education. Of those that were educated, the most common source was “self-education” (69.8%) and content was “to keep levels of exercise the same” (29.8%). Conclusions: There is a need for education to be available and easily accessible for girls and women which provides instructions on managing the MC and other commitments alongside sports/exercise, and highlights the many benefits of participating in regular sports/exercise.
Climate policies that achieved major emission reductions: Global evidence from two decades
Authors: Stechemesser Annika , Koch Nicolas , Mark Ebba , Dilger Elina , Klösel Patrick , Menicacci Laura , Nachtigall Daniel , Pretis Felix , Ritter Nolan , Schwarz Moritz , Vossen Helena , Wenzel Anna
Published: August 2024

Meeting the Paris Agreement’s climate targets necessitates better knowledge about which climate policies work in reducing emissions at the necessary scale. We provide a global, systematic ex post evaluation to identify policy combinations that have led to large emission reductions out of 1500 climate policies implemented between 1998 and 2022 across 41 countries from six continents. Our approach integrates a comprehensive climate policy database with a machine learning–based extension of the common difference-in-differences approach. We identified 63 successful policy interventions with total emission reductions between 0.6 billion and 1.8 billion metric tonnes CO
2
. Our insights on effective but rarely studied policy combinations highlight the important role of price-based instruments in well-designed policy mixes and the policy efforts necessary for closing the emissions gap.
AI and biosecurity: The need for governance
Authors: Bloomfield Doni , Pannu Jaspreet , Zhu Alex W. , Ng Madelena Y. , Lewis Ashley , Bendavid Eran , Asch Steven M. , Hernandez-Boussard Tina , Cicero Anita , Inglesby Tom
Published: August 2024

Governments should evaluate advanced models and if needed impose safety measures
Physiological significance of the two isoforms of initiator tRNAs in
Escherichia coli
Authors: Sahu Amit Kumar , Shah Riyaz Ahmad , Nashier Divya , Sharma Prafful , Varada Rajagopal , Lahry Kuldeep , Singh Sudhir , Shetty Sunil , Hussain Tanweer , Varshney Umesh
Published: August 2024

Escherichia coli
possesses four initiator tRNA (i-tRNA) genes, three of which are present together as
metZWV
and the fourth one as
metY
. In
E. coli
B, all four genes (
metZWV
and
metY
) encode i-tRNA
fMet1
, in which the G at position 46 is modified to m
7
G46 by TrmB (m
7
G methyltransferase). However, in
E. coli
K, because of a single-nucleotide polymorphism,
metY
encodes a variant, i-tRNA
fMet2
, having an A in place of m
7
G46. We generated
E. coli
strains to explore the importance of this polymorphism in i-tRNAs. The strains were sustained either on
metY
A46
(
metY
of
E. coli
K origin encoding i-tRNA
fMet2
) or its derivative
metY
G46
(encoding i-tRNA
fMet1
) in single (chromosomal) or plasmid-borne copies. We show that the strains sustained on i-tRNA
fMet1
have a growth fitness advantage over those sustained on i-tRNA
fMet2
. The growth fitness advantages are more pronounced for the strains sustained on i-tRNA
fMet1
in nutrient-rich media than in nutrient-poor media. The growth fitness of the strains correlates well with the relative stabilities of the i-tRNAs
in vivo
. Furthermore, the atomistic molecular dynamics simulations support the higher stability of i-tRNA
fMet1
than that of i-tRNA
fMet2
. The stability of i-tRNA
fMet1
remains unaffected upon the deletion of TrmB. These studies highlight how
metY
G46
and
metY
A46
alleles might influence the growth fitness of
E. coli
under certain nutrient-limiting conditions.

IMPORTANCE

Escherichia coli
harbors four initiator tRNA (i-tRNA) genes: three of these at
metZWV
and the fourth one at
metY
loci. In
E. coli
B, all four genes encode i-tRNA
fMet1
. In
E. coli
K, because of a single-nucleotide polymorphism, metY encodes a variant, i-tRNA
fMet2
, having an A in place of G at position 46 of i-tRNA sequence in metY. We show that G46 confers stability to i-tRNA
fMet1
. The strains sustained on i-tRNA
fMet1
have a growth fitness advantage over those sustained on i-tRNA
fMet2
. Strains harboring
metY
G46
(B mimic) or
metY
A46
(K mimic) show that while in the nutrient-rich media, the K mimic is outcompeted rapidly; in the nutrient-poor medium, the K mimic is outcompeted less rapidly.
Intranasal administration of octavalent next-generation influenza vaccine elicits protective immune responses against seasonal and pre-pandemic viruses
Authors: Uno Naoko , Ebensen Thomas , Guzman Carlos A. , Ross Ted M.
Published: August 2024

Development of next-generation influenza virus vaccines is crucial to improve protection against circulating and emerging viruses. Current vaccine formulations have to be updated annually due to mutations in seasonal strains and do not offer protection against strains with pandemic potential. Computationally optimized broadly reactive antigen (COBRA) methodology has been utilized by our group to generate broadly reactive immunogens for individual influenza subtypes, which elicit protective immune responses against a broad range of strains over numerous seasons. Octavalent mixtures of COBRA hemagglutinin (HA) (H1, H2, H3, H5, H7, and influenza B virus) plus neuraminidase (NA) (N1 and N2) recombinant proteins mixed with c-di-AMP adjuvant were administered intranasally to naive or pre-immune ferrets in prime-boost fashion. Four weeks after final vaccination, collected sera were analyzed for breadth of antibody response, and the animals were challenged with seasonal or pre-pandemic strains. The octavalent COBRA vaccine elicited antibodies that recognized a broad panel of strains representing different subtypes, and these vaccinated animals were protected against influenza virus challenges. Overall, this study demonstrated that the mixture of eight COBRA HA/NA proteins mixed with an intranasal adjuvant is a promising candidate for a universal influenza vaccine.

IMPORTANCE

Influenza is a respiratory virus which infects around a billion people globally every year, with millions experiencing severe illness. Commercial vaccine efficacy varies year to year and can be low due to mismatch of circulating virus strains. Thus, the formulation of current vaccines has to be adapted accordingly every year. The development of a broadly reactive influenza vaccine would lessen the global economic and public health burden caused by the different types of influenza viruses. The significance of our research is producing a promising universal vaccine candidate which provides protection against a wider range of virus strains over a wider range of time.
Impact of organic compounds on the stability of influenza A virus in deposited 1-μL droplets
Authors: Schaub Aline , David Shannon C. , Glas Irina , Klein Liviana K. , Violaki Kalliopi , Terrettaz Céline , Motos Ghislain , Bluvshtein Nir , Luo Beiping , Pohl Marie , Hugentobler Walter , Nenes Athanasios , Krieger Ulrich K. , Peter Thomas , Stertz Silke , Kohn Tamar
Published: August 2024

The composition of respiratory fluids influences the stability of viruses in exhaled aerosol particles and droplets, though the role of respiratory organics in modulating virus stability remains poorly understood. This study investigates the effect of organic compounds on the stability of influenza A virus (IAV) in deposited droplets. We compare the infectivity loss of IAV at different relative humidities (RHs) over the course of 1 h in 1-µL droplets consisting of phosphate-buffered saline (without organics), synthetic lung fluid, or nasal mucus (both containing organics). We show that IAV stability increases with increasing organic:salt ratios. Among the various organic species, proteins are identified as the most protective component, with smaller proteins stabilizing IAV more efficiently at the same mass concentration. Organics act by both increasing the efflorescence RH and shortening the drying period until efflorescence at a given RH. This research advances our mechanistic understanding of how organics stabilize exhaled viruses and thus influence their inactivation in respiratory droplets.

IMPORTANCE

This study investigates how the composition of respiratory fluids affects the stability of viruses in exhaled droplets. Understanding virus stability in droplets is important as it impacts how viruses spread and how we can combat them. We focus on influenza A virus (IAV) and investigate how different organic compounds found in lung fluid and nasal mucus protect the virus from inactivation. We demonstrate that the ratio of organics to salt in the fluid is an indicator of IAV stability. Among organics, small proteins are particularly effective at protecting IAV. Their effect is in part explained by the proteins’ influence on the crystallization of salts in the droplets, thereby shielding the viruses from prolonged exposure to harmful salt concentrations. Understanding these mechanisms helps us grasp how viruses sustain their infectivity over time in respiratory droplets, contributing to efforts in controlling infectious diseases.
Essential genes for
Haemophilus parainfluenzae
survival and biofilm growth
Authors: de Palma Thais H. , Powers Chris , McPartland Morgan J. , Mark Welch Jessica , Ramsey Matthew
Published: August 2024

Haemophilus parainfluenzae
(
Hp
) is a Gram-negative, highly prevalent, and abundant commensal in the human oral cavity, and an infrequent extraoral opportunistic pathogen.
Hp
occupies multiple niches in the oral cavity, including the supragingival plaque biofilm. Little is known about how
Hp
interacts with its neighbors in healthy biofilms nor its mechanisms of pathogenesis as an opportunistic pathogen. To address this, we identified the essential genome and conditionally essential genes in
in vitro
biofilms aerobically and anaerobically. Using transposon insertion sequencing (TnSeq) with a highly saturated
mariner
transposon library in two strains, the ATCC33392 type-strain (
Hp
392) and oral isolate EL1 (
Hp
EL1), we show that the essential genomes of
Hp
392 and
Hp
EL1 are composed of 395 (20%) and 384 (19%) genes, respectively. The core essential genome, consisting of 341 (17%) essential genes conserved between both strains, was composed of genes associated with genetic information processing, carbohydrate, protein, and energy metabolism. We also identified conditionally essential genes for aerobic and anaerobic biofilm growth, which were associated with carbohydrate and energy metabolism in both strains. RNAseq analysis determined that most genes upregulated during anaerobic growth are not essential for
Hp
392 anaerobic survival. The completion of this library and analysis under these conditions gives us a foundational insight into the basic biology of
H. parainfluenzae
in differing oxygen conditions, similar to its
in vivo
habitat. This library presents a valuable tool for investigation into conditionally essential genes for an organism that lives in close contact with many microbial species in the human oral habitat.

IMPORTANCE

Haemophilus parainfluenzae
is a highly abundant human commensal microbe, present in most healthy individuals where it colonizes the mouth.
H. parainfluenzae
correlates with good oral health and may play a role in preservation of healthy host status. Also,
H. parainfluenzae
can cause opportunistic infections outside of the oral cavity. To date, little is known about how
H. parainfluenzae
colonizes the human host, despite being such a frequent and abundant part of our human microbiome. Here, we demonstrate the creation and use of a powerful tool, a TnSeq library, used to identify genes necessary for both the outright growth of this organism and also genes conditionally essential for growth in varying oxygen status which it can encounter in the human host. This tool and these data serve as a foundation for further study of this relatively unknown organism that may play a role in preserving human health.