bluuebunny/crossref_metadata_2025 huggingface dataset:
Gill's stability problem may be unstable with horizontal heterogeneity in permeability
Authors: Shankar B.M. , Shivakumara I.S.
Published: June 2022

The linear stability of thermal buoyant flow in a fluid-saturated vertical porous slab is studied under the assumption of weak and strong horizontal heterogeneities of the permeability. The two end vertical isothermal boundaries are impermeable and some paradigmatic cases of linear, quadratic and exponential heterogeneity models are deliberated. The stability/instability of the basic flow is examined by carrying out a numerical solution of the governing equations for the disturbances as Gill's proof (A.E. Gill, J. Fluid Mech, vol. 35, 1969, pp. 545–547) of linear stability is found to be ineffective. The possibilities of base flow becoming unstable due to heterogeneity in permeability are recognized, in contrast to Gill's stability problem. The neutral stability curves are presented and the critical Darcy–Rayleigh number for the onset of convective instability is computed for different values of the variable permeability constant. The similarities and differences between different heterogeneity models on the stability of fluid flow are clearly discerned.
Development of the Vietnamese Healthy Eating Index
Authors: Van Duong T. T. , Trijsburg Laura , Do Ha T. P. , Kurotani Kayo , Feskens Edith J. M. , Talsma Elise F.
Published: June 2022

Poor dietary quality is a major contributor to malnutrition and disease burden in Vietnam, necessitating the development of a tool for improving dietary quality. Food-based dietary guidelines (FBDGs) have been proposed to do this by providing specific, culturally appropriate and actionable recommendations. We developed the Vietnamese Healthy Eating Index (VHEI) to assess the adherence to the 2016–2020 Vietnamese FBDGs and the dietary quality of the general Vietnamese population. This VHEI consists of eight component scores, ‘grains’, ‘protein foods’, ‘vegetables’, ‘fruits’, ‘dairy’, ‘fats and oils’, ‘sugar and sweets’ and ‘salt and sauces’, representing the recommendations in the FBDGs. Each component score ranges from 0 to 10, resulting in a total VHEI score between 0 (lowest adherence) and 80 (highest adherence). The VHEI was calculated using dietary intake data from the Vietnamese General Nutrition Survey 2009–2010 (n = 8225 households). Associations of the VHEI with socio-demographic characteristics, energy and nutrient intakes and food group consumptions were examined. The results showed that the mean and standard deviation score of the VHEI was 43⋅3 ± 8⋅1. The component ‘sugar and sweets’ scored the highest (9⋅8 ± 1⋅1), whereas the component ‘dairy’ scored the lowest (0⋅6 ± 1⋅6). The intake of micronutrients was positively associated with the total VHEI, both before and after adjustment for energy intake. In conclusion, the VHEI is a valuable measure of dietary quality for the Vietnamese population regarding their adherence to the FBDGs.
Earliest western Atlantic staghorn corals (Acropora) from the lower Oligocene Suwannee Limestone of Florida, USA, and their significance for modern coral distribution
Authors: Wallace Carden C. , Portell Roger W.
Published: June 2022

The Suwannee Limestone of Florida and Georgia, USA, is a carbonate paleoenvironment with a rich diversity of marine fossils. These record the presence of coral- and seagrass-bearing communities in the western Atlantic from the Eocene/Oligocene boundary to the mid Oligocene (33.9–28.1 Ma). From the Suwannee Limestone, we describe two new species of the cosmopolitan, diverse, and abundant coral genusAcropora(“staghorn corals”),Acropora suwanneensisnew species andAcropora upchurchinew species, which predate all other describedAcroporaspecies from the Americas and Caribbean by at least 10 million years. Diminutive skeletal structure in both species is indicative of their living in protected calm-water habitats. At their time of occurrence, an Atlantic–Pacific connection was open through Central America. Both species belong to morphological lineages also present in the fossil record of the eastern Atlantic (Europe, or the western Tethys). These lineages no longer occur in the Atlantic Ocean, but they are extant in the Indo-Pacific region, with the closest modern relative of each new species occurring in the Pacific Ocean to central Indo-Pacific. Some species in the two morphological lineages have existed for up to 20+ million years. The new species may have played a part in perpetuating a cosmopolitan Tethyan fauna and expandingAcroporahabitats in the western Atlantic, by which they likely also contributed to the renowned species and habitat diversity ofAcroporain the modern Indo-Pacific.

UUIDhttps://zoobank.org/40118623-8b82-4352-a065-b58da74a5c41
Popular Mexican Masculinity and American Culture in the 1920s: Migrants andFifís
Authors: Serna Laura Isabel
Published: June 2022

This essay examines the discourse around Mexican masculinity in the 1920s by looking at the figures of the repatriated migrant and the urban dandy of the period, thefifí. Using evidence from print culture, popular literature, and other sources, it explains how these masculine figures provoked anxieties about sexuality, work, and public space, as well as concerns about how to integrate American mass culture into revolutionary Mexican society. Though many observers saw repatriated migrants and fifís as potentially destructive to Mexico’s body politic, others crafted cultural narratives that described how to integrate men’s encounters with American culture into modern Mexican masculinity.
Mathematical Responses to the Hole Argument: Then and Now
Authors: Bradley Clara , Weatherall James Owen
Published: June 2022

We argue that several apparently distinct responses to the hole argument, all invoking formal or mathematical considerations, should be viewed as a unified “mathematical response.” We then consider and rebut two prominent critiques of the mathematical response before reflecting on what is ultimately at issue in this literature.
Prospects for Analogue Confirmation
Authors: Bartha Paul
Published: June 2022

In analogical reasoning, observations about one or more source domains provide varying degrees of support for a conjecture about a target domain. Norton (2021) challenges the usefulness of formal models of analogical inference. Other philosophers (Dardashti et al. 2019) develop just such formal models in order to show how analogue experiments can confirm a hypothesis, even when the target domain is inaccessible. This paper defends the value of quasi-formal models of analogical reasoning. Such models are broadly compatible with Norton’s position, but help to clarify the structure of analogical reasoning and to identify basic requirements for a good analogical inference.
REINTERPRETATION OF FLUVIAL-AEOLIAN SEDIMENTS FROM LAST GLACIAL TERMINATION CLASSIC TYPE LOCALITIES USING HIGH-RESOLUTION RADIOCARBON DATA FROM THE POLISH PART OF THE EUROPEAN SAND BELT
Authors: Sokołowski Robert J , Moska Piotr , Zieliński Paweł , Jary Zdzisław , Piotrowska Natalia , Raczyk Jerzy , Mroczek Przemysław , Szymak Agnieszka , Krawczyk Marcin , Skurzyński Jacek , Poręba Grzegorz , Łopuch Michał , Tudyka Konrad
Published: June 2022

This paper presents 66 radiocarbon (14C) dates obtained at 33 key sites from the Polish part of the European Sand Belt. These calibrated dating results were compared to 34 high-resolution 14C dates obtained from a fluvial-aeolian sediments to identify pedogenic phases from the late Pleniglacial interval to the early Holocene. These identified pedogenic phases were correlated with Greenland ice-core records, revealing high sensitivity of the fluvio-aeolian paleoenvironment to climate changes. Two pedogenic phases were identified from the late Pleniglacial interval (Greenland Stadial GS-2.1b and GS-2.1a), three from the Bølling-Allerød interstadial (Greenland Stadial GI-1), one from the late Allerød–Younger Dryas boundary, and at least one from the Younger Dryas. The ages of these pedogenic phases reveal a distinct delay of 50–100 calendar years after the onset of cool climate conditions during GI-1, reflecting gradual withdrawal of vegetation. Soil horizons from the early Holocene do not show any clear relation with climate change, where breaks in soil formation were caused by local factors such as human activity.
From Defensive to Transformative Business Diplomacy: The British South Africa Company and the End of Chartered Company Rule in Rhodesia, 1910–1925
Authors: Rönnbäck Klas , Broberg Oskar
Published: June 2022

Chartered companies were important tools of European colonialism, but also institutions with a political agenda of their own. In this study, we focus upon one key chartered company, the British South Africa Company, in particular the ending of its charter in 1923/24, in order to study the business diplomacy strategies employed by the company. We show how the company during the period under study moved from a reactive and defensive diplomacy strategy concerning its charter, to a proactive and transformative strategy. In this way, the company managed to renegotiate the terms under which it operated so that it eventually came to accept and even embrace the ending of chartered rule, rather than to oppose it.
The Newport Quinsy Simulator
Authors: Sheehan S , Green E , Grimshaw L
Published: June 2022

Background

The junior otolaryngologist is responsible for recognition and drainage of the peritonsillar abscess. Although other simulators have been proposed, there is still a need for an accessible, educationally useful, low-cost peritonsillar abscess simulator to build skills and confidence in the novice.

Methods

The peritonsillar abscess simulator was constructed from basic disposable healthcare equipment and a party balloon. Evaluation of this Newport Quinsy Simulator was performed by expert and novice clinicians, who provided feedback in the form of Likert scales and free-text qualitative responses.

Results

Overall, 24 clinicians evaluated the simulator. All felt the simulator was useful for the novice otolaryngologist, and represented the key anatomy and motor skills needed to drain a peritonsillar abscess. Qualitative evaluation highlighted the educational usefulness of the simulator as a peritonsillar abscess training device.

Conclusion

The Newport Quinsy Simulator is affordable, accessible, easy to use and educationally valuable to the novice otolaryngologist.
Following in the Footsteps: Exemplarity, Ethnicity and Ethics in 1 Peter
Authors: Marcar Katie
Published: June 2022

First Peter 1.3–2.10 weaves a new familial and ethnic identity for believers through a complex series of interlocking metaphors. How does this identity influence the ethical exhortation beginning in 2.11? The current article argues that an answer is found in the Greco-Roman structures of exemplarity. First, the article identifies four explicit markers of exemplarity discourse in 1 Peter: ὑπογραμμός (2.21), the footsteps idiom (2.21), the term ἀντίτυπος (3.21) and the term τύποι (5.3). Next, it surveys how exemplarity functioned in the Greco-Roman world. Greek and Roman literature demonstrate a clear preference for domestic exempla. Similarly, as a new family and ethnic group, Christian believers require new exempla suited to their new Christian identity. In this light, 1 Peter's ethical instruction can be more deeply appreciated. Finally, this article investigates how exemplarity dynamics illuminate Jesus as exemplar par excellence in 1 Peter. First Peter depicts Jesus’ passion with language of the Isaianic suffering servant (2.22–5). Jesus’ exemplarity is given to slaves, who are implicitly held up as models for all believers. Exemplarity thus draws its strength from the past (the suffering servant, Jesus) as it challenges those in the present and future (slaves, all believers) to become like these models.
Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode
Authors: Segura Alex G. , Mezquida Gisela , Martínez-Pinteño Albert , Gassó Patricia , Rodriguez Natalia , Moreno-Izco Lucía , Amoretti Silvia , Bioque Miquel , Lobo Antonio , González-Pinto Ana , García-Alcon Alicia , Roldán-Bejarano Alexandra , Vieta Eduard , de la Serna Elena , Toll Alba , Cuesta Manuel J. , Mas Sergi , Bernardo Miquel ,   PEPs Group
Published: June 2022

Background

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder.

Methods

The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status.

Results

Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001).

Conclusions

Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent.
The Alan capital *Magas: A preliminary identification of its location
Authors: Latham-Sprinkle John
Published: June 2022

This article proposes that *Magas, capital city of the North Caucasian Kingdom of Alania, can be identified with the gorodishche (hillfort) of Il'ichevsk, in Krasnodar Krai in the modern Russian Federation. The Kingdom of Alania was the most powerful polity in the North Caucasus in the tenth and eleventh centuries; however, the location of its capital has never been satisfactorily established. This article reviews the evidence of written sources on *Magas – notably Masʿūdī, Juvayni, Rashid al-Din, and the Yuan-Shi – and identifies four criteria which can be used to identify the site of *Magas. These are its occupation between the tenth and thirteenth centuries; the influence of the Alan kings over it; its massive fortifications; and its capture by the Mongols in 1239–40. All of these features can be identified at Il'ichevsk, in contrast to previously proposed sites of *Magas.
Mixed precision algorithms in numerical linear algebra
Authors: Higham Nicholas J. , Mary Theo
Published: June 2022

Today’s floating-point arithmetic landscape is broader than ever. While scientific computing has traditionally used single precision and double precision floating-point arithmetics, half precision is increasingly available in hardware and quadruple precision is supported in software. Lower precision arithmetic brings increased speed and reduced communication and energy costs, but it produces results of correspondingly low accuracy. Higher precisions are more expensive but can potentially provide great benefits, even if used sparingly. A variety of mixed precision algorithms have been developed that combine the superior performance of lower precisions with the better accuracy of higher precisions. Some of these algorithms aim to provide results of the same quality as algorithms running in a fixed precision but at a much lower cost; others use a little higher precision to improve the accuracy of an algorithm. This survey treats a broad range of mixed precision algorithms in numerical linear algebra, both direct and iterative, for problems including matrix multiplication, matrix factorization, linear systems, least squares, eigenvalue decomposition and singular value decomposition. We identify key algorithmic ideas, such as iterative refinement, adapting the precision to the data, and exploiting mixed precision block fused multiply–add operations. We also describe the possible performance benefits and explain what is known about the numerical stability of the algorithms. This survey should be useful to a wide community of researchers and practitioners who wish to develop or benefit from mixed precision numerical linear algebra algorithms.
Turnpike in optimal control of PDEs, ResNets, and beyond
Authors: Geshkovski Borjan , Zuazua Enrique
Published: June 2022

Theturnpike propertyin contemporary macroeconomics asserts that if an economic planner seeks to move an economy from one level of capital to another, then the most efficient path, as long as the planner has enough time, is to rapidly move stock to a level close to the optimal stationary or constant path, then allow for capital to develop along that path until the desired term is nearly reached, at which point the stock ought to be moved to the final target. Motivated in part by its nature as a resource allocation strategy, over the past decade, the turnpike property has also been shown to hold for several classes of partial differential equations arising in mechanics. When formalized mathematically, the turnpike theory corroborates insights from economics: for an optimal control problem set in a finite-time horizon, optimal controls and corresponding states are close (often exponentially) most of the time, except near the initial and final times, to the optimal control and the corresponding state for the associated stationary optimal control problem. In particular, the former are mostly constant over time. This fact provides a rigorous meaning to the asymptotic simplification that some optimal control problems appear to enjoy over long time intervals, allowing the consideration of the corresponding stationary problem for computing and applications. We review a slice of the theory developed over the past decade – the controllability of the underlying system is an important ingredient, and can even be used to devise simple turnpike-like strategies which are nearly optimal – and present several novel applications, including, among many others, the characterization of Hamilton–Jacobi–Bellman asymptotics, and stability estimates in deep learning via residual neural networks.
Can sperm quality influence embryo development and its ploidy? Analysis of 811 blastocysts obtained from different sperm sources
Authors: Polese Romualdo , Scarselli Filomena , Dale Brian , Minasi Maria Giulia , Greco Ermanno
Published: June 2022

The aim of our study was to evaluate the correlation between sperm quality and ploidy status of the derived blastocysts. We performed a retrospective analysis on a restricted pool of patients enrolling only those who had no female factors. Male patients with genetic factors affecting spermatogenesis were also excluded. We chose a maternal age ≤38 years to decrease the female factor, therefore the male factor was the main component of sterility. We divided the patients in four groups based on semen quality and comparing fertilization, pregnancy and euploidy rates above all. In total, 201 intracytoplasmic sperm injection (ICSI) cycles were enrolled in the study. Cycles were divided into four groups, according to semen source: normal semen, oligoasthenoteratozoospermia (OAT), cryptospermia or non-obstructive azoospermia (NOA). An extremely statistically lower fertilization rate was found in NOA patients. Unexpectedly, no differences were detected in blastocyst formation, euploidy, aneuploidy and mosaicism rates among the four groups. Interestingly, we also found a higher abortion rate comparing NOA to normal semen with an odds ratio of 4.67. In our study no statistically significant differences among the analyzed groups were found, showing little or no effect at all using spermatozoa from different semen sources or quality. This may be linked to the oocyte competence of fixing sperm DNA damage and it could be hypothesized that only sperm with a good rate of DNA integrity are able to fertilize the oocyte, explaining why poor quality semen is reflected in a low fertilization rate without effect on ploidy.
Confronting the Modern Executive: Four Perspectives
Authors: Levinson Sanford
Published: June 2022

It is no secret that political power in the United States and elsewhere has, overall, shifted to “the executive” and away from legislatures. There may be debate about whether this is a product of willful “overreaching” by executives or whether, within the United States, Congress has instead willingly ceded power by engaging in what Justice Cardozo in 1935 called “delegation run riot.” The concern about executive power has perhaps become heightened in the aftermath of the Trump presidency—just as Boris Johnson, with his own defiance of some of the “conventions” that are essential to the British constitutional order, is provoking debate in Great Britain.
Response model of fluid–rock ratio to reservoir space in primary formation of shale oil during hydrous pyrolysis
Authors: SUN Lina , FU Deliang , ZHANG Qi , WU Yuandong
Published: June 2022

Due to the presence of geological fluid under actual geological conditions, water–rock interaction will occur between the fluid and reservoir. Thus, to analyse the influence of the water–rock interaction on storage space during the organic matter evolution stages, this study conducted a series of simulation experiments on shales by using a closed autoclave: four temperatures, 250°C, 300°C, 350°C, 400°C, and five fluid–rock ratios (FRRs), 0:20, 4:20, 10:20, 15:20, and 20:20. Low pressure N2 adsorption measurement was conducted on the solid residues. The experimental results show that the effect of temperature on the yield and pore structure of oil shale was the same as the result when the FRR was = 0:20, 4:20 and = 10:20, 15:20, 20:20, respectively. This result showed that temperature remained the main factor that affected the thermal evolution of hydrocarbon generation. Additionally, temperature was beneficial to the generation and storage of shale oil within a certain range, but only occupied the storage space of shale oils or connected a certain storage space beyond a certain range. The variation trend of shale oil yield with increasing FRR under the same simulated temperatures, 250°C and 400°C, was most affected by the FRR, but little change occurred at 300°C and 350°C. This further proved that the ratio of fluid to rock was an indirect acting factor, which affected the evolution of organic matters and then the development of pore structures. Before the oil window (350°C), the lower evolution degree, the higher water content and the more significant effect. In the higher evolution stage, the higher the water content, and the more complete the kerogen reaction, which was also more conducive to the development of pore structures. Therefore, this study promotes the establishment of linear equations on FRR to the gas adsorption capacity, which further provides a theoretical basis and guidance for the exploration and development of shale oil.
Religion and international humanitarian law
Authors: Bartles-Smith Andrew
Published: June 2022

This article explores the interface between religion and international humanitarian law (IHL), and the degree to which they might complement and reinforce each other. It examines some of the challenges inherent in regulating armed conflict and the understandable limitations of IHL in this respect, and argues that re-engagement with IHL's religious roots can help to alleviate them. Engagement with religious circles mobilizes the vast resources of religions to increase knowledge of IHL and corresponding religious norms, thereby enhancing their legitimacy across religious and cultural divides. This is most effective when comparative study of IHL and religious teachings stimulates mutual learning and debate, in which both correspondences and differences are embraced. In the absence of a strong legal enforcement regime, religions can reinforce military ethics by tapping deeply into the identities, motivations and moral values of many belligerents, and possess powerful means to socialize the rules of war and improve voluntary compliance. Introspective religious practices encourage the moral self-reflection that is most effective at internalizing norms in this respect, as well as providing belligerents with the spiritual and psychological support needed to bolster their resilience and enable them to perform with precision and restraint.
Cucumber tolerance to glufosinate applied preplant or preemergence
Authors: Randell Taylor M. , Vance Jenna C. , Hand Lavesta C. , Grey Timothy L. , Culpepper A. Stanley
Published: June 2022

Georgia vegetable growers produce more than 27% of the nation’s fresh-market cucumbers. To maximize yields and profit, fields must be weed-free when planting. Limitations with current burndown herbicide options motivated academic, industry, and U.S. Department of Agriculture partners to search for new tools to assist growers. One possibility, glufosinate, controls many common and troublesome weeds, but its influence on cucumber development through residual activity when applied before or at planting is not understood. Thus, four different studies were each conducted two to four times from 2017 to 2020 to determine 1) transplant cucumber response to preplant glufosinate applications as influenced by rate, overhead irrigation, and interval between application and planting; and 2) seeded cucumber response to preemergence (PRE) glufosinate applications as influenced by rate, overhead irrigation, and planting depth. Glufosinate applied at 330, 660, 980, and 1,640 g ai ha−1 the day before transplanting caused 11% to 53% injury on sandy, low organic matter soils. Cucumber vine lengths and plant biomass were reduced up to 28% and 46%, respectively, with the three highest rates. Early-season yield (harvests 1 to 4) noted a 31% to 60% yield loss with glufosinate at 660 to 1,640 g ha−1 with similar trends observed with total yield (11 to 13 harvests). Irrigation (0.75 cm) after application and before transplanting reduced injury to less than 21%, eliminated vine length and biomass suppression except at the highest rate, and eliminated yield loss. Extending the interval between glufosinate application and transplanting from 1 to 4 d was not beneficial, and further extending the interval to 7 d significantly reduced injury half the time. When applied PRE to seeded cucumber and combining the data across locations, glufosinate caused less than 7% injury even at 1,640 g ha−1. Seeded plant vine lengths, biomass, and marketable yield were not influenced by the PRE application, and neither irrigation nor planting depth influenced seeded crop response to glufosinate.
Interaction between tolpyralate and atrazine for the control of annual weed species in corn
Authors: Fluttert John C. , Soltani Nader , Galla Mariano , Hooker David C. , Robinson Darren E. , Sikkema Peter H.
Published: June 2022

Many studies have documented the interaction between 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting and photosystem II (PSII)-inhibiting herbicides. Most have focused on the interaction between mesotrione and atrazine, with only a few studies characterizing the nature of the interaction between tolpyralate and atrazine. Therefore, five field experiments were conducted in Ontario, Canada, over a 3-yr period (2019 to 2021) to characterize the interaction between three rates of tolpyralate (15, 30, and 45 g ai ha−1) and three rates of atrazine (140, 280, and 560 g ai ha−1) for the control of seven annual weed species in corn (Zea mays L.). Tolpyralate at 30 or 45 g ha−1 applied with atrazine at 280 or 560 g ha−1 controlled velvetleaf (Abutilon theophrasti Medik.), redroot pigweed (Amaranthus retroflexus L.), common ragweed (Ambrosia artemisiifolia L.), common lambsquarters (Chenopodium album L.), and wild mustard (Sinapis arvensis L.) >90% at 8 wk after application (WAA). Tolpyralate and atrazine were synergistic at each rate combination for the control of A. theophrasti at 8 WAA. In contrast, A. retroflexus and S. arvensis control at 8 WAA was additive with each rate combination. At 8 WAA, C. album control was generally additive, but one rate combination was synergistic. Ambrosia artemisiifolia control at 8 WAA was synergistic with five rate combinations and additive with the other four. Barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control at 8 WAA was additive with seven of the rate combinations and synergistic with two. Setaria spp. control at 8 WAA was synergistic with one more rate combination compared with E. crus-galli, but the two weed species shared the same synergistic rate combinations. This study concludes that extrapolation or broad classifications of the interaction between tolpyralate and atrazine would be inappropriate, as the interaction can vary due to herbicide rate, weed species, and the response parameter analyzed.
Regional Climate Effects of Irrigation Over Central Asia Using Weather Research and Forecasting Model
Authors: Wu Liyang , Feng Jinming , Qin Fen , Qiu Yuan
Published: June 2022

A dynamic irrigation scheme in which soil moisture acts as an irrigation trigger was incorporated into the Weather Research and Forecasting model coupled with the Noah‐Mosaic land surface model, in which irrigation was only considered in irrigated portions within each grid cell. Two experiments (with and without irrigation) were first designed and continuously run 21 years (1994–2014) to simulate the impacts of irrigation over Central Asia on regional climate. Soil moisture after irrigation increased greatly because of the large irrigation amount. Irrigation significantly increased latent heat flux through increasing soil evaporation and transpiration, and their contributions to increases in latent heat flux were roughly equal. The sensible heat flux was decreased because of the increased latent heat flux, which led to decreases in surface air temperature and land surface temperature. The simulations of temperature and soil moisture in croplands were improved in experiment with irrigation. The daily minimum surface air temperature was slightly affected by irrigation, even increased during nonirrigation period. During daytime, the airflows blowing from croplands to mountains would also bring parts of the increased water vapor to mountainous areas. Since the increased water vapor was transported upward in mountainous areas, irrigation obviously increased precipitation here. Multiple sensitivity experiments were conducted, and all concluded that irrigation over Central Asia led to increases in precipitation in mountainous areas, which showed that the conclusion was certain and not affected by the selected parameterization schemes and the simulated irrigation amount.
MAVEN Observations of H− Ions in the Martian Atmosphere
Authors: Jones N. , Halekas J. , Girazian Z. , Mitchell D. , Mazelle C.
Published: June 2022

At Mars, charge exchange between solar wind protons and neutral exospheric hydrogen produces energetic neutral atoms (ENAs) that can penetrate into the collisional atmosphere, where they can be converted through collisions into H+ and H−. The Mars Atmosphere and Volatile EvolutioN mission observed a population of negatively charged particles at low altitudes, whose energies, angular distribution, and dependence on the upstream solar wind were consistent with H− produced by solar wind hydrogen ENAs. The highest fluxes of H− were observed near perihelion and the southern summer solstice. We calculated an average ratio of ∼4% between H− density and H+ density, implying a slightly smaller relative abundance than reported previously (∼10%). We found that the fraction of H ENAs converted to H− increases with the solar wind energy, in agreement with laboratory measurements of the H–CO2 electron capture cross section.
Infrasonic and Seismic Analysis of Debris‐Flow Events at Illgraben (Switzerland): Relating Signal Features to Flow Parameters and to the Seismo‐Acoustic Source Mechanism
Authors: Belli Giacomo , Walter Fabian , McArdell Brian , Gheri Duccio , Marchetti Emanuele
Published: June 2022

Debris flows are among the most dangerous phenomena in mountain environment. Recently the use of seismic and infrasonic recordings has proven to be a powerful tool for studying and monitoring debris flows. However, open questions remain about how signal characteristics refllect flow parameters and fluid dynamic processes. We present a seismo‐acoustic analysis of the debris flow activity between 2017 and 2019 at the Illgraben catchment (Switzerland). Seismic and infrasonic amplitudes (maximum root mean square amplitude [RMSA]) and peak frequencies are compared with flow measurements (front velocity, maximum flow depth and density). Front velocity, maximum depth, peak discharge and peak mass flux show a positive correlation with both infrasonic and seismic maximum RMSA, suggesting that seismo‐acoustic amplitudes are influenced by these flow parameters. Comparison between seismo‐acoustic peak frequencies and flow parameters reveals that, unlike seismic signals, characterized by a constant peak frequency regardless of the magnitude of the flow, infrasound peak frequency decreases with increasing flow velocity, depth and discharge. Our results suggest that infrasound and seismic waves are generated by different source processes, acting at the flow free surface and at the channel bed respectively. We propose that infrasound is likely generated by waves and oscillations that develop at the surface of the flow, which, according to fluid dynamics, are mostly generated wherever the flow encounters significant channel irregularities. Furthermore, the observed positive correlations between seismo‐acoustic signal features and flow parameters highlight the potential to use infrasound and seismic measurements for debris‐flow monitoring and risk management.
Atmospheric Lengthscales for Global VSWIR Imaging Spectroscopy
Authors: Thompson David R. , Bohn Niklas , Brodrick Philip G. , Carmon Nimrod , Eastwood Michael L. , Eckert Regina , Fichot Cédric G. , Harringmeyer Joshua P. , Nguyen Hai M. , Simard Marc , Thorpe Andrew K.
Published: June 2022

Future global Visible Shortwave Infrared Imaging Spectrometers, such as the Surface Biology and Geology (SBG) mission, will regularly cover the Earth's entire terrestrial land area. These missions need high fidelity atmospheric correction to produce consistent maps of terrestrial and aquatic ecosystem traits. However, estimation of surface reflectance and atmospheric state is computationally challenging, and the terabyte data volumes of global missions will exceed available processing capacity. This article describes how missions can overcome this bottleneck using the spatial continuity of atmospheric fields. Contemporary imaging spectrometers oversample atmospheric spatial variability, so it is not necessary to invert every pixel. Spatially sparse solutions can train local linear emulators that provide fast, exact inversions in their vicinity. We find that estimating the atmosphere at 200 m scales can outperform traditional atmospheric correction, improving speed by one to two orders of magnitude with no measurable penalty to accuracy. We validate performance with an airborne field campaign, showing reflectance accuracies with RMSE of 1.1% or better compared to ground measurements of diverse targets. These errors are statistically consistent with retrieval uncertainty budgets. Local emulators can close the efficiency gap and make rigorous model inversion algorithms feasible for global missions such as SBG.
Stress Evolution Before and After the 2021 Mw 7.3 Maduo Earthquake in Northeastern Tibet and Its Influence on Seismic Hazards
Authors: Liu Chang , Zhang Hang , Chen Jianquan , Shi Yaolin
Published: June 2022

The 2021 Mw 7.3 Maduo earthquake ruptured the Kunlun Pass‐Jiangcuo fault (KPJF) in the Bayan Har Block (BHB) in northeastern Tibet. To explore the reasons behind the Maduo earthquake and the seismic hazards that followed this event in the BHB, we simulated the Coulomb stress changes before and after 2021 caused by 27 large historical earthquakes in the past centuries. We found that the Maduo earthquake was delayed for approximately 157 years because of the stress shadow resulting from fault interaction in the BHB. This stress shadow was mainly controlled by the 1937 Mw 7.5 earthquake on the Eastern Kunlun fault (EKLF) and the 1947 Mw 7.75 earthquake on the Dari fault. The stress shadow created by the Maduo earthquake covered several strike‐slip faults surrounding the Maduo earthquake rupture through negative feedback. Future seismic activity in the stress shadow zone may be delayed to a certain extent. Based on this finding, we propose that earthquakes on a fault might inhibit earthquakes on surrounding faults in parallel strike‐slip fault systems by creating a shadow zone in the BHB. This finding is important for understanding earthquake generation and migration in northeastern Tibet. It is also helpful for understanding the fault interactions in similar fault systems globally. The seismic hazards of the seismic gap to the west of the KPJF and the Maqin‐Maqu seismic gap on the EKLF increased after the Maduo earthquake. Therefore, attention should be paid to hazards prevention in these regions.
Evaluating the Robustness of NISAR's Cropland Product to Time of Observation, Observing Mode, and Dithering
Authors: Kraatz S. , Siqueira P. , Kellndorfer J. , Torbick N. , Huang X. , Cosh M.
Published: June 2022

Cropland mapping is important for monitoring agricultural practices, cropland distribution and for supporting food security programs. Radar remote sensing will likely provide a means of cropland mapping, which can be efficient, accurate, and globally applied. Algorithms used for spaceborne radar cropland mapping are still undergoing calibration and validation efforts, necessitating ground and aircraft‐based campaigns ahead of launch. The upcoming NASA ISRO SAR (NISAR) mission will map croplands at 1 ha spatial resolution using a coefficient of variation approach. NASA Jet Propulsion Laboratory recently released simulated NISAR data over cropland calibration sites including morning (AM), evening (PM), and dithered with and without gaps. These freely available simulated data allow for making accurate a priori estimates of how NISAR’s cropland science algorithm is impacted by factors such as orbit (i.e., the incidence angle, time of day), bandwidth (i.e., whether the 5, 20, or 40 MHz channels are used), and varying the system's pulse repetition frequency—a process known as dithering. This study investigates these science mission questions over agricultural regions in Mississippi and Arkansas, USA. Results show that compositing data from both orbits (AM + PM) yielded comparable classification accuracy to using only one of AM or PM data. The study also found that dithering only slightly decreased cropland mapping capability (<0.3% accuracy reduction).
Electron Signatures of Reconnection in a Global eVlasiator Simulation
Authors: Alho M. , Battarbee M. , Pfau‐Kempf Y. , Khotyaintsev Yu. V. , Nakamura R. , Cozzani G. , Ganse U. , Turc L. , Johlander A. , Horaites K. , Tarvus V. , Zhou H. , Grandin M. , Dubart M. , Papadakis K. , Suni J. , George H. , Bussov M. , Palmroth M.
Published: June 2022

Geospace plasma simulations have progressed toward more realistic descriptions of the solar wind–magnetosphere interaction from magnetohydrodynamic to hybrid ion‐kinetic, such as the state‐of‐the‐art Vlasiator model. Despite computational advances, electron scales have been out of reach in a global setting. eVlasiator, a novel Vlasiator submodule, shows for the first time how electromagnetic fields driven by global hybrid‐ion kinetics influence electrons, resulting in kinetic signatures. We analyze simulated electron distributions associated with reconnection sites and compare them with Magnetospheric Multiscale (MMS) spacecraft observations. Comparison with MMS shows that key electron features, such as reconnection inflows, heated outflows, flat‐top distributions, and bidirectional streaming, are in remarkable agreement. Thus, we show that many reconnection‐related features can be reproduced despite strongly truncated electron physics and an ion‐scale spatial resolution. Ion‐scale dynamics and ion‐driven magnetic fields are shown to be significantly responsible for the environment that produces electron dynamics observed by spacecraft in near‐Earth plasmas.
Deriving Full‐Coverage and Fine‐Scale XCO2 Across China Based on OCO‐2 Satellite Retrievals and CarbonTracker Output
Authors: He Changpei , Ji Mingrui , Li Tao , Liu Xinyi , Tang Die , Zhang Shifu , Luo Yuzhou , Grieneisen Michael L. , Zhou Zihang , Zhan Yu
Published: June 2022

Due to the coarse spatial resolution, the column‐averaged dry‐air mole fraction of CO2 (XCO2) data from the CarbonTracker may be inadequate to reflect the spatial heterogeneity of XCO2. We developed a machine learning model to fill the data gaps in the Orbiting Carbon Observatory 2 satellite retrievals across China during 2015–2018, with cross‐validation R2 = 0.95 and RMSE = 0.91 ppm. Based on the gap‐filled data set, the multiyear average XCO2 was the highest in East China (405.71 ± 3.72 ppm) and the lowest in Northwest China (403.99 ± 3.47 ppm). At the national level, the multiyear seasonal XCO2 varied from 402.54 ± 3.95 ppm in summer to 406.28 ± 3.19 ppm in spring. While the XCO2 kept increasing, the rate of increase declined from 3.23 to 2.10 ppm/year. The machine learning approach is feasible for downscaling and calibrating the CarbonTracker XCO2 data. The full‐coverage and fine‐scale XCO2 data set is expected to advance our understanding of the carbon cycles.
Tree Rings Reveal Unmatched 2nd Century Drought in the Colorado River Basin
Authors: Gangopadhyay Subhrendu , Woodhouse Connie A. , McCabe Gregory J. , Routson Cody C. , Meko David M.
Published: June 2022

The ongoing 22‐year drought in the Upper Colorado River Basin (UCRB) has been extremely severe, even in the context of the longest available tree‐ring reconstruction of annual flow at Lees Ferry, Arizona, dating back to 762 CE. While many southwestern drought assessments have been limited to the past 1,200 years, longer paleorecords of moisture variability do exist for the UCRB. Here, gridded drought‐atlas data in the UCRB domain along with naturalized streamflow data from the instrumental period (1906–2021) are used in a K‐nearest neighbor nonparametric algorithm to develop a streamflow reconstruction for the Lees Ferry gage starting in 1 CE. The reconstruction reveals a second‐century drought unmatched in severity by the current drought or by well‐documented medieval period droughts in the UCRB. Although data are sparse, analysis of individual long tree‐ring records and other paleoclimatic data also support the occurrence of an exceptional second‐century drought.
A Global Perspective on Lunar Granular Flows
Authors: Bickel V. T. , Loew S. , Aaron J. , Goedhart N.
Published: June 2022

Dry granular flows are ubiquitous, yet poorly understood mass wasting features on the Moon. Above all, their global distribution, relation to the physical environment, and drivers are poorly understood. Here, we build and deploy a convolutional neural network and map 28,101 flow features between 60°N and S by scanning through ∼150,000 Lunar Reconnaissance Orbiter images. We observe that flows are heterogeneously distributed over the Moon, where all major hotspots are located in craters and almost all hotspots are located in the nearside maria. We further observe that younger surfaces feature higher flow feature densities, while pre‐Nectarian terranes can still host flows, remaining subject to active erosion billions of years after their formation. Our observations suggest that impacts at various scales have been—and likely still are—acting as the main, global‐scale, long‐ and short‐term driver of flow occurrence, strongly influenced by the properties of the target rock material.
Reevaluating Links Between Meteorite Impacts and Early Cenozoic Global Warming
Authors: Zorzi A. , Tikoo S. M. , Beroza G. C. , Sleep N. H.
Published: June 2022

The Paleocene‐Eocene Thermal Maximum (PETM) and the lower Chron 29n hyperthermal event were recently proposed to have been triggered by the meteorite impacts that formed the Marquez Dome (Texas, USA; 58.3 ± 3.1 Ma) and Boltysh (Ukraine; 65.39 ± 0.14 Ma) craters, respectively. We use shock physics hydrocode simulations and radiative forcing calculations to quantify the expected global temperature increase associated with impacts of different scales via the release of CO2 and CH4 sourced from target rocks into the atmosphere. Our results suggest that the <2 km diameter impactors associated with the Marquez Dome and Boltysh craters were too small to have induced hyperthermal‐like (>1 K) temperature changes, even if target rocks were carbon‐rich; >10 km diameter impactors may produce hyperthermal events, but such large impacts are predicted to be uncommon during the Cenozoic era (2–4 objects per Gyr).
Diverse P‐T‐t Paths Reveal High‐Grade Metamorphosed Forearc Complexes in NW China
Authors: Wang Hao , Xiao Wenjiao , Windley Brian F. , Zhang Qian W. L. , Tan Zhou , Wu Chunming , Shi Mengyan
Published: June 2022

Subduction zones provide important constraints on reconstruction of tectonic configurations and convergent geodynamics. The timing and evolution of the subduction zones at the interaction between the Paleo‐Asian and Tethyan Oceans remain ambiguous, casting significant uncertainty on the reconstructions of proto‐Asia and subduction dynamics. Here, we report new petrologic and geochronologic data of a high‐grade metamorphic complex in the Dunhuang area, NW China, together with thermodynamic modeling, geothermobarometry, and second ion mass spectrometry U‐Pb chronology to reveal the complex metamorphic structure and history of the Paleozoic subduction‐exhumation channel at the intersection of the Paleo‐Asian and Tethyan domains. The subduction zone contains a diverse collection of eclogite, high‐pressure (HP) granulites, amphibolites, and metasedimentary rocks with a broad spectrum of P‐T‐t paths, which were buried and exhumed at different depths at ∼463–411 Ma. Our first dating of the oldest (∼463 Ma) HP granulite extends the orogenic period earlier to the Middle Ordovician. The uneven change in subduction gradients from ∼18°C/km to ∼10°C/km illustrates the thermal evolution of the subduction zone from infancy to maturity. A dramatic drop of the gradient at ∼420 Ma suggests a potential short‐term switch of the subduction dynamics from “hot” to “cool,” possibly due to plate geometry reorganization in response to slab roll‐back. Our data demonstrate that the Dunhuang Complex was chaotically mixed and juxtaposed at different levels in the subduction‐exhumation channel. The southward younging and increase in depth of the HP metamorphism indicate that the Dunhuang Complex was formed by north‐dipping subduction of the Proto‐Tethyan Ocean from the Early Paleozoic.