bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in diet and food shopping behaviors among Asian–American adults due to COVID‐19
Authors: Rummo Pasquale E. , Naik Rhea , Thorpe Lorna E. , Yi Stella S.
Published: January 2021

Objective

COVID‐19 has changed diet and food shopping behaviors, but a lack of disaggregated data by racial and ethnic subgroup makes it challenging to identify whether specific populations are experiencing greater challenges in safely securing an adequate food supply and engaging in healthy eating behaviors during the pandemic. Thus, the objective of this study was to measure such changes among Asian–American (AA) adults, overall and by ethnic subgroup.

Methods

Using a nationally derived nonprobability sample, 3084 AA adults were recruited, including 1737 East Asian, 570 South Asian, 587 Southeast Asian, and 124 multiethnic Asian adults. Participants completed an online survey with questions related to sociodemographics, health status, and diet and food shopping behaviors, including questions related to COVID‐19. Logistic and linear regression were used to compare differences in survey responses by Asian ethnic subgroup.

Results

Compared to other AA subgroups, a higher percentage of Asian Indian (17%), Filipino (13%), Vietnamese (12%), and Korean (11%) adults reported no longer getting food resources they were receiving before COVID‐19 (e.g., mobile meals, food pantry items). The percentage of Filipino (8%) and Vietnamese (7%) adults who reported not having enough money to buy food they need was also higher than other AA subgroups. And a higher percentage of Asian Indian adults (7%) reported not having a way to get to the food store since COVID‐19 than other AA subgroups.

Conclusions

Previous work has not included disaggregated data, which may mask important disparities in food access and food insecurity among people hit hardest by COVID‐19, such as Filipino, Vietnamese, and Asian Indian households.
Spatiotemporal determinants of seasonal gleaning
Authors: Grantham Ruby , Álvarez‐Romero Jorge G. , Mills David J. , Rojas Cristian , Cumming Graeme S.
Published: January 2021

Many coastal communities depend on ecosystems for goods and services that contribute to human well‐being. As long‐standing interactions between people and nature are modified by global environmental change, dynamic and diversified livelihood strategies that enable seasonal adaptation will be critical for vulnerable coastal communities. However, the success of such strategies depends on a range of poorly understood influences.

Gleaning, the hand‐based collection of marine organisms from littoral habitats, provides an interesting case study of dynamic change in social‐ecological interactions. It is an important coastal livelihood strategy, yet seasonal gleaning dynamics have not been empirically explored in contemporary communities. We examined seasonal gleaning in eight coastal communities on Atauro Island, Timor‐Leste, using household surveys and satellite‐derived maps of shallow‐water benthic habitats. Our analysis explored the factors affecting household decisions to glean in each season, the relationship between gleaning and seafood consumption, and seasonal gleaning pressure on near‐shore coastal resources.

Dynamic marine harvesting strategies differed among households and gleaning activity was seasonally heterogeneous. Not all gleaning households gleaned during the season characterised by rough sea conditions despite rough season gleaning being associated with greater seafood consumption stability among seasons. Households also gleaned less regularly, and catches were smaller, in the rough season.

Differences in seasonal participation in gleaning were explained mostly by type and extent of shallow habitat proximate to a community. In the calm season, household gleaning was positively related to the total area of shallow habitat, and in the rough season the percentage of hard‐bottom shallow habitat was also an important predictor of gleaning activity.

Our findings illustrate how changes in the biophysical environment mediate human–nature interactions at fine scales through time and space. Consequently, this research highlights the importance of context‐specific perspectives for understanding drivers and dynamics in fishing pressure on littoral ecosystems, access to ecosystem benefits and limits to adaptation. Factors influencing when livelihood activities are feasible and desirable are important for evaluating the social impacts of climate change, particularly in the context of rural communities in the Global South.

A free Plain Language Summary can be found within the Supporting Information of this article.
The effect of boron carbide additive on the low‐velocity impact properties of low‐density foam core composite sandwich structures
Authors: Geren Necdet , Acer Durmus Can , Uzay Cagri , Bayramoglu Melih
Published: January 2021

Sandwich structures with carbon fiber‐epoxy face sheets and polyvinyl chloride foam core material are known for their high strength and flexural stiffness despite their low weight. However, the structural response, in terms of crush strength, of the particles added sandwich structures are not very well known under impact loading conditions. In this study, the impact resistance and damage characteristics of particle added low weight composite sandwich structures were investigated with a low‐velocity drop weight impact test device. Boron carbide (B4C) particles, which had excellent hardness, thermoelectric, and radiation absorbing characteristics, were used as an additive for the epoxy matrix. For this purpose, 2%, 5%, and 10% by weight additives were mixed into the epoxy matrix and sandwich structures were produced with hand lay‐up followed by vacuum bagging method. All configurations were subjected to low‐velocity drop weight impact test at three different energy levels (10, 17.50, and 25 J). The results obtained from the experiments and the images of the post‐impact damage of the sandwich structures were presented comparatively. According to the test results, configurations containing 10% boron carbide (B4C) additive has shown the best performance in terms of resistance to impact load.
The role of attachment avoidance: A longitudinal mediation model predicting existential distress in patients with advanced cancer
Authors: Philipp Rebecca , Mehnert‐Theuerkauf Anja , Koranyi Susan , Härter Martin , Vehling Sigrun
Published: January 2021

Objective

Although a protective effect of reliable interpersonal relationships on existential distress has been established, evidence remains inconclusive for attachment insecurity as an underlying factor of persistent psychological distress. We tested a longitudinal model hypothesizing attachment avoidance as a mediator of high demoralization and anxiety over time.

Methods

We studied 206 patients with advanced cancer (mean age = 59.6, 61% female) participating in an intervention trial. Patients completed self‐report measures for demoralization, anxiety, perceived relatedness, attachment insecurity, and death anxiety. Our mediated path model included perceived relatedness and death anxiety at baseline as predictors, attachment avoidance at baseline as mediator, and demoralization and anxiety at 6‐month follow‐up (N = 125) as outcomes.

Results

Attachment avoidance partially mediated the relationship between death anxiety and demoralization (β = 0.07, 95% CI 0.02–0.12) and anxiety (β = 0.05, 95% CI 0.001–0.10). Findings for perceived relatedness were less conclusive. Its indirect effects through attachment avoidance were significant for both outcomes (demoralization: β = −0.07, 95% CI −0.13 to −0.02, anxiety: β = −0.05, 95% CI −0.11 to −0.003).

Conclusions

Due to its trait‐like quality, attachment avoidance may play a less central role in explaining the course of existential distress over time than previous research indicated. Addressing change‐sensitive relational concerns in psychosocial interventions may be more effective to alleviate existential distress.
Widespread co‐occurrence of Sebacinales and arbuscular mycorrhizal fungi in switchgrass roots and soils has limited dependence on soil carbon or nutrients
Authors: Lee Marissa R. , Hawkes Christine V.
Published: January 2021

Societal Impact Statement

This work addresses a novel group of Sebacinales mycorrhizal fungi being considered for development as inoculants in managed ecosystems because of their potential access to nutrients in soil organic matter. By comparing the diversity, distributions, and abundances of the Sebacinales with the more common arbuscular mycorrhizal fungi in switchgrass, a biofuel crop, we demonstrate that current suggestions for a Sebacinales revolution in agriculture should be tempered by their ecology. In particular, Sebacinales are rare compared to arbuscular mycorrhizal fungi, and are only weakly associated with soil carbon, suggesting that ideas about improved soil carbon cycling associated with Sebacinales need to be sufficiently studied across a range of environmental conditions prior to their consideration for broad‐spectrum soil inoculants.

Arbuscular mycorrhizal (AM) fungi are widespread and important root symbionts, but recent work suggests that Sebacinales fungi may play an equally important role in both plant success and ecosystem carbon and nutrient cycling based on their worldwide occurrence and putative access to organic matter. However, the ecological impacts of Sebacinales will depend on their abundance and distribution relative to AM fungi and environmental soil carbon and nutrient patterns, which remain unexplored.

We characterized Glomeromycota and Sebacinales fungi in switchgrass (Panicum virgatum L.) roots and soils across 14 sites with diverse soil conditions. We examined group richness differences, co‐occurrence patterns, and how the relative abundance of these fungi related to soil carbon, nutrient stoichiometry, and host size.

Sebacinales were widespread, but less diverse, common, and abundant than Glomeromycota. Moreover, co‐occurrences were predominantly random, suggesting relatively few interactions between these groups. Sebacinales increased relative to Glomeromycota in soils with more carbon, but explanatory power was limited.

Based on our findings, we suggest that Sebacinales are likely complementary to AM fungi in roots. Expectations that Sebacinales have large effects on soil carbon and nutrient cycling may need to be reconsidered, at least based on their limited abundances relative to AM fungi in switchgrass. This is an important consideration as Sebacinales are candidates for use as inoculants in managed ecosystems.
An Experimental Investigation of Corner‐Turning Performance in a Large Double Cylinder of Highly‐Insensitive Explosive
Authors: Cornell Rodger E. , Wrobel Erik T.
Published: January 2021

When creating ignition and growth models for new explosive formulations, it is crucial to have a complete understanding of transverse detonation growth within the material to accurately predict corner‐turning performance in various geometries. This understanding is particularly important when designing a direct replacement for an existing explosive, typically with requirements to maintain function in terms of both initiation and end effects/lethality. While there have been many corner‐turning tests developed and successfully utilized over the last 60 years, many of the experimental designs favor traditional explosives that tend to exhibit ideal growth behavior. Many of the traditional corner‐turning tests exhibit prohibitive complications when faced with geometric scale‐up to accommodate large critical diameters that often accompany insensitive behavior. In an effort to address this shortcoming, the authors propose a corner‐turning test that can easily scale to accommodate a wide range of critical diameters and introduces modern diagnostics to provide additional data known to be useful for model development. As a case study for IMX‐104, the work herein uses a combination of streaked fiber optics and photonic Doppler velocimetry probes (PDV) to investigate corner turning within a large double cylinder geometry. Additionally, diameter effects on detonation velocity measurements, front wave curvature, and extent of reaction at various PDV probe locations are investigated using the same diagnostics. These experimental results have since been used to improve an IMX‐104 ignition and growth model that has been used to support the development of numerous warhead designs – notably the 155 mm family of artillery munitions.
Cookoff of Black Powder and Smokeless Powder
Authors: Hobbs Michael L. , Kaneshige Michael J.
Published: January 2021

We have completed a series of both vented and sealed cookoff experiments of black powder and smokeless powder in our Sandia Instrumented Thermal Ignition (SITI) apparatus at bulk densities of 1078 and 729 kg/m3, respectively. The confining aluminum cylinder was ramped from room temperature to a set point temperature and then held at the setpoint temperature until ignition. The setpoint temperatures varied between 495 to 523 K for the black powder and 401 to 412 K for the more sensitive smokeless powder. The vented experiments show a significant delay in thermal ignition, indicating that the ignition is dependent on pressure. Post experimental debris shows greater violence for our smokeless powder experiments than our black powder experiments. A simplified universal cookoff model (UCM) was calibrated using the black powder and smokeless powder SITI data and used to predict pressurization and thermal ignition. The current work presents the first calibration of the UCM with a double base propellant. This work also presents the first pressure‐dependent cookoff model for black powder and smokeless powder.
Back Cover Image
Authors: Li Nan , Tang Haitao , Wu Liang , Ge Haitao , Wang Yurong , Yu Honglin , Zhang Xiuli , Ma Jimei , Gu Harvest F.
Published: January 2021

The cover image is based on the Review Chemical constituents, clinical efficacy and molecular mechanisms of the ethanol extract of Abelmoschus manihot flowers in treatment of kidney diseases by Nan Li et al., https://doi.org/10.1002/ptr.6818.

image
Doping Quantum Spin Liquids on the Kagome Lattice
Authors: Peng Cheng , Jiang Yi‐Fan , Sheng Dong‐Ning , Jiang Hong‐Chen
Published: January 2021

The authors review recent density‐matrix renormalization group studies of lightly doped quantum spin liquids (QSLs) on the kagome lattice. While a number of distinct conducting phases, including high temperature superconductivity, have been theoretically anticipated, a tendency toward fractionalized insulating charge‐density‐wave (CDW) states is instead found. In agreement with earlier work [Jiang, Devereaux, and Kivelson, Phys. Rev. Lett. 2017, 119, 067002], results for the t‐J model reveal that, starting from a fully gapped QSL, light doping leads to CDW long‐range order with a pattern that depends on lattice geometry and doping concentration such that there is one doped‐hole per CDW unit cell, while the spin–spin correlations remain short‐ranged. Alternatively, this state can be viewed as a stripe crystal or Wigner crystal of spinless holons, rather than of doped holes. From here, by studying generalized versions of the t‐J model, these results are extended to light doping of other types of QSLs, including critical and chiral QSLs. These results suggest that doping these QSLs also leads to insulating states with long‐range CDW order. While the superconducting correlations are short‐ranged, they can be significantly enhanced by second‐neighbor electron hopping. The relevance of these numerical results to Kagome materials is also discussed.
A case of diffuse large B‐cell lymphoma originating from chest wall complicated by benign asbestos pleural effusion
Authors: Kondo Nobuyuki , Inoue Yukihisa , Takeyama Hiroaki , Kobayashi Akiko , Matsubara Osamu , Jinn Yasuto
Published: January 2021

A 78‐year‐old man with exposure to asbestos was admitted to our hospital for back pain. A chest computed tomography showed right pleural effusion and a significant increase in the size of masses in the right chest wall over an interval of six months. He did not undergo further examinations and expired one month later. Autopsy revealed the presence of diffuse large B‐cell lymphoma (DLBCL) and complicated by benign asbestos pleural effusion. We considered that this tumour had originated from the soft tissue in the chest wall based on the radiological and autopsy findings. The present report highlights that primary DLBCL of chest wall might be associated with chronic inflammation due to asbestos‐related pleural diseases.
Field evaluation of a compact, polarizing topo‐bathymetric lidar across a range of river conditions
Authors: Kinzel Paul J. , Legleiter Carl J. , Grams Paul E.
Published: January 2021

This paper summarizes field trials to evaluate the performance of a prototype compact topo‐bathymetric lidar sensor for surveying rivers. The sensor uses a novel polarization technique to distinguish between laser returns from the water surface and streambed and its size and weight permit deployment from a small unmanned aerial system (sUAS) or a boat. Field testing was designed to identify the range of operational conditions under which the sensor can provide accurate information on river depths. For accuracy assessment, conventional, field‐based depth measurements were collected by wading and sonar. Additionally, optical properties of the rivers were measured in situ. Wading and lidar bathymetry comparisons in relatively shallow channels yielded observed versus predicted (OP) regression R2 values ranging from 0.60 to 0.97. A comparison between sonar and lidar bathymetry in a deeper river resulted in an OP R2 of 0.72. Absorption and attenuation coefficients at the 532 nm wavelength of the lidar were recorded in the field and the highest values of these inherent optical properties were at sites with the highest turbidity and highest concentrations of colored dissolved organic matter, chlorophyll, and suspended sediment. At these sites, which included both sand and gravel/cobble beds, the point density of riverbed returns was not uniform, with areas of sparse coverage occurring primarily in deeper water. However, submerged objects and slopes could be resolved in the lidar point clouds.
Server configuration optimization in mobile edge computing: A cost‐performance tradeoff perspective
Authors: He Zhenli , Li Kenli , Li Keqin , Zhou Wei
Published: January 2021

Before service providers build up an mobile edge computing (MEC) platform, an important issue that needs to be considered is the configuration of computing resources on edge servers. Since the computing resources on an edge server are limited compared with a cloud server and the service provider's deployment budget is limited, it would be unrealistic to equip all edge servers with abundant computing resources. In addition, the edge servers have different computation demands due to their different geographies. Therefore, this article investigates the problem of server configuration optimization in an MEC environment based on a given computation demand statistics of the selected deployment locations. Our strategy is to treat each edge server as an M/M/m queueing model, and then establish the performance and cost models for the system. Two optimization problems, including cost constrained performance optimization, and performance constrained cost optimization are formulated based on our models and solved by a series of fast numerical algorithms. We also conduct extensive numerical simulation examples to show the effectiveness of the proposed algorithms. MEC service providers can use our strategy to get the appropriate type of processor and obtain the optimal processor number for each edge server to achieve two different goals: (1) deliver the highest‐quality services with a given cost constraint; (2) minimize the investment cost with a service‐quality guarantee. Our research is of great significance for service providers to control the tradeoff between investment cost and service quality.
Electrogenerated NHCs in Organic Synthesis: Ionic Liquids vs Organic Solvents Effects
Authors: Vetica Fabrizio , Bortolami Martina , Petrucci Rita , Rocco Daniele , Feroci Marta
Published: January 2021

In the last twenty years, N‐heterocyclic carbenes (NHCs) have been extensively studied for their application as organocatalysts in stereoselective synthesis as well as ligands for transition metals‐promoted synthetic methodologies. Derived mainly from azolium salts, NHCs have demonstrated exceptional versatility in their generation usually performed by deprotonation or reduction (chemical or electrochemical). In particular, the generation of NHC under electrochemical conditions, starting from azolium‐based ionic liquids, has proven to be a successful green approach and demonstrated wide applicability in organic synthesis. In this Personal Account, the application of electrogenerated NHCs in organic synthesis will be discussed, with a particular attention to the different reactivity in ionic liquids compared to classical organic solvents.
Amplitude Statistics of Nakagami‐m Distributed Weather Clutter Observed by X‐Band Marine Radar
Authors: Sayama Shuji
Published: January 2021

Under strong wind caused by a low pressure with fronts passing near Honshu, I have observed weather clutter containing targets (ships) using an X‐band marine radar with a frequency of 9.41 GHz, a beamwidth of 1.0°, a pulsewidth of 0.5 μs, and a pulse‐repetition frequency of 1600 Hz. To investigate such clutter amplitude statistics, I have introduced the Nakagami‐m distribution to radar signal processing for the first time and used the Akaike Information Criterion (AIC). It has been found that the weather clutter amplitudes obey the Nakagami‐m distribution with the shape parameter of m = 5.85 for entire data and the log‐normal, Weibull, log‐Weibull, and Nakagami‐m distributions with the shape parameters of σ = 0.189 to 0.259, c = 6.52 to 7.81, c = 26.66 to 35.51, and m = 5.23, respectively, for small data within the beam width of an antenna. The number of the minimum AIC (MAIC) of the log‐normal, Weibull, log‐Weibull, and Nakagami‐m distributions to data is 4, 12, 4, and 1, respectively, from 21 small data. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Melatonin increases the anticancer potential of doxorubicin in Caco‐2 colorectal cancer cells
Authors: Jadid Mahdieh Farhoudi Sefidan , Aghaei Elnaz , Taheri Elham , Seyyedsani Nasrin , Chavoshi Reza , Abbasi Samane , Khorrami Afshin , Goleij Pouya , Hajazimian Saba , Taefehshokr Sina , Isazadeh Alireza , Shanehbandi Dariush
Published: January 2021

Colorectal cancer (CC) is an important human malignancy with high cancer related death worldwide. The chemotherapy using doxorubicin hydrochloride is one of the most common cancer therapeutic methods. However, drug resistance lowers the treatment efficacy in CC patients. The combination therapies seem to be more promising by taking the advantage of synergistic effects. The present study aimed to evaluate a new strategy to enhance the anticancer activity of doxorubicin in Caco‐2 CC cell line by co‐administration of melatonin. The effects of doxorubicin, melatonin, and their combinations (Dox‐Mel) were investigated on the proliferation and viability, morphological alterations, and tumor spheroid formation. Flow cytometry was employed to compare the apoptotic situation of the cells in study groups. Changes in metastatic potential of the cells were assessed by wound healing assay and trans‐well migration assays. Moreover, expression of BAX, SMAC, BCL‐2, SURVIVIN, MMP‐2, and MMP‐9 genes were evaluated by quantitative real time PCR and western blotting. Our study showed that doxorubicin, melatonin, and Dox‐Mel significantly decreased the proliferation and viability, tumor spheroid formation, invasion, and migration. Furthermore, the changes were in a concentration and time dependent manner. There was an increase in apoptosis rate in the treatment groups. Expression of genes involved in apoptosis and cell motility were altered significantly. It was observed that anticancer activity of Dox‐Mel combination was significantly more than doxorubicin and melatonin treatments alone. We showed an enhanced apoptotic and anticancer activity of doxorubicin and melatonin combination chemotherapy on CC cell line than doxorubicin or melatonin treatments alone. This combination could promote the treatment efficiency and alleviate the un‐intended side effects by lowering the dose of doxorubicin prescription.
Evapotranspiration estimation in rain gardens using soil moisture sensors
Authors: Hess Amanda , Wadzuk Bridget , Welker Andrea
Published: January 2021

Rain gardens are increasing in use as the shift from gray to green infrastructure continues. Water that enters a rain garden is removed by three mechanisms: overflow to an outlet, percolation to the underlying soil, and evapotranspiration (ET) to the atmosphere. Despite the importance of ET in aiding a rain garden to recover void space during the time between storm events, it is not often measured or calculated because it is so difficult to do so. This paper explores the use of soil moisture sensors to estimate ET, since they are relatively inexpensive to purchase and install. Three rain garden weighing lysimeters in Villanova, PA, were used for this study. Over a 3‐yr study period daily ET was calculated each dry day and summed during the time in between storm events >25 mm. The cumulative changes of soil moisture readings during the interevent time at three depths were compared with the concurrent cumulative changes in the lysimeter weight readings. Cumulative soil moisture change was found to be strongly correlated to the cumulative ET for the different lysimeter media and drainage types. Using the two soil moisture sensors at the top and bottom of the soil column provided a similar result to using all soil moisture reading depths. The best single soil moisture reading depth was at the bottom of the lysimeter. The ET estimates via soil moisture tracking performed similar to uncalibrated potential ET estimates, but not as well as calibrated ET estimates.
The Smart Rivers approach: Spatial quality in flood protection and floodplain restoration projects based on river DNA
Authors: Peters Bart , van Buuren Michaël , van den Herik Keesjan , Daalder Martijn , Tempels Barbara , Rijke Jeroen , Pedroli Bas
Published: January 2021

Many river rehabilitation projects have been implemented in the past 30 years, strengthening the natural dynamics and ecology of river systems, while reconciling the functions of flood protection, navigation, sediment extraction, and cultural identity. Still, the planning and design of floodplain projects is subject to debate on how to best follow the “natural” characteristics of specific river stretches, the “DNA of the river.” Unlike many other approaches of integrated river management, this approach entails a design strategy for spatial quality in river floodplain development projects at local and regional level, where the current discharge characteristics of the upstream river basin are taken as given. Starting point is the landscape ecological basis of the river, defining the characteristic (hydro‐morphological) processes and geomorphological/geological structures in each stretch of the river and floodplain area. An in‐depth characterization of these structures and processes helps design floodplains that can accommodate the various river management and development objectives. Often economically strong functions, like flood protection, can be partnered with weaker ones, such as ecosystem restoration. To safeguard spatial quality and sustainability in these integrated projects, the governance aspect is essential. Therefore the Smart Rivers approach addresses both substantial aspects (the “DNA of the River”) as well as procedural and governance elements (called the “Quality Relay”). The principles of the approach are applicable to project design along regulated rivers in densely populated areas all over the world.

This article is categorized under:

Water and Life > Conservation, Management, and Awareness
Bootstrapping Coulomb and Higgs branch operators
Authors: Gimenez-Grau Aleix , Liendo Pedro
Published: January 2021

Abstract

We apply the numerical conformal bootstrap to correlators of Coulomb and Higgs branch operators in 4d$$ \mathcal{N} $$
N
= 2 superconformal theories. We start by revisiting previous results on single correlators of Coulomb branch operators. In particular, we present improved bounds on OPE coefficients for some selected Argyres-Douglas models, and compare them to recent work where the same cofficients were obtained in the limit of large r charge. There is solid agreement between all the approaches. The improved bounds can be used to extract an approximate spectrum of the Argyres-Douglas models, which can then be used as a guide in order to corner these theories to numerical islands in the space of conformal dimensions. When there is a flavor symmetry present, we complement the analysis by including mixed correlators of Coulomb branch operators and the moment map, a Higgs branch operator which sits in the same multiplet as the flavor current. After calculating the relevant superconformal blocks we apply the numerical machinery to the mixed system. We put general constraints on CFT data appearing in the new channels, with particular emphasis on the simplest Argyres-Douglas model with non-trivial flavor symmetry.
O(n, n) invariance and Wald entropy formula in the Heterotic Superstring effective action at first order in α′
Authors: Ortín Tomás
Published: January 2021

Abstract

We perform the toroidal compactification of the full Bergshoeff-de Roo version of the Heterotic Superstring effective action to first order in α′. The dimensionally-reduced action is given in a manifestly-O(n, n)-invariant form which we use to derive a manifestly-O(n, n)-invariant Wald entropy formula which we then use to compute the entropy of α′-corrected, 4-dimensional, 4-charge, static, extremal, supersymmetric black holes.
Machine learning and algebraic approaches towards complete matter spectra in 4d F-theory
Authors: Bies Martin , Cvetič Mirjam , Donagi Ron , Lin Ling , Liu Muyang , Ruehle Fabian
Published: January 2021

Abstract

Motivated by engineering vector-like (Higgs) pairs in the spectrum of 4d F-theory compactifications, we combine machine learning and algebraic geometry techniques to analyze line bundle cohomologies on families of holomorphic curves. To quantify jumps of these cohomologies, we first generate 1.8 million pairs of line bundles and curves embedded in dP3, for which we compute the cohomologies. A white-box machine learning approach trained on this data provides intuition for jumps due to curve splittings, which we use to construct additional vector-like Higgs-pairs in an F-Theory toy model. We also find that, in order to explain quantitatively the full dataset, further tools from algebraic geometry, in particular Brill-Noether theory, are required. Using these ingredients, we introduce a diagrammatic way to express cohomology jumps across the parameter space of each family of matter curves, which reflects a stratification of the F-theory complex structure moduli space in terms of the vector-like spectrum. Furthermore, these insights provide an algorithmically efficient way to estimate the possible cohomology dimensions across the entire parameter space.
Collider probes of real triplet scalar dark matter
Authors: Chiang Cheng-Wei , Cottin Giovanna , Du Yong , Fuyuto Kaori , Ramsey-Musolf Michael J.
Published: January 2021

Abstract

We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV pp collider. We focus on the scenario in which the neutral triplet scalar is stable and contributes to the dark matter relic density. When produced in pp collisions, the charged triplet scalar decays to the neutral component plus a soft pion or soft lepton pair, yielding a disappearing charged track in the detector. We recast current 13 TeV LHC searches for disappearing tracks, and find that the LHC presently excludes a real triplet scalar lighter than 248 (275) GeV, for a mass splitting of 172 (160) MeV with ℒ = 36 fb−1. The reach can extend to 497 (520) GeV with the collection of 3000 fb−1. We extrapolate the 13 TeV analysis to a prospective 100 TeV pp collider, and find that a ∼ 3 TeV triplet scalar could be discoverable with ℒ = 30 ab−1, depending on the degree to which pile up effects are under control. We also investigate the dark matter candidate in our model and corresponding present and prospective constraints from dark matter direct detection. We find that currently XENON1T can exclude a real triplet dark matter lighter than ∼ 3 TeV for a Higgs portal coupling of order one or larger, and the future XENON20T will cover almost the entire dark matter viable parameter space except for vanishingly small portal coupling.
Generalization of Heron’s and Brahmagupta’s equalities to any cyclic polygon
Authors: Dulio Paolo , Laeng Enrico
Published: January 2021

It is well known that Heron’s equality provides an explicit formula for the area of a triangle, as a symmetric function of the lengths of its edges. It has been extended by Brahmagupta to quadrilaterals inscribed in a circle (cyclic quadrilaterals). A natural problem is trying to further generalize the result to cyclic polygons with a larger number of edges. Surprisingly, this has proved to be far from simple, and no explicit solutions exist for cyclic polygons having $$n>4$$

n
>
4

edges. In this paper we investigate such a problem by following a new and elementary approach, based on the idea that the simple geometry underlying Heron’s and Brahmagupta’s equalities hides the real players of the game. In details, we propose to focus on the dissection of the edges determined by the incircles of a suitable triangulation of the cyclic polygon, showing that this approach leads to an explicit formula for the area as a symmetric function of the lengths of these segments. We also show that such a symmetry can be rediscovered in Heron’s and Brahmagupta’s results, which consequently represent special cases of the provided general equality.
Individual layer fabrication (ILF): a novel approach to additive manufacturing by the use of wood
Authors: Henke Klaudius , Talke Daniel , Bunzel Frauke , Buschmann Birger , Asshoff Carsten
Published: January 2021

A novel process named ‘individual layer fabrication (ILF)’ is presented, in which objects are built up by laminating individually contoured wood-based panels. However, contrary to the well-known process of ‘laminated object manufacturing (LOM)’, in ILF, the individual panels are not shaped by a subtractive process but additively by selective binding of wooden particles. The particles are spread as a thin layer onto a built platform. A liquid adhesive is then applied only to those areas where the contoured panel is to be generated. As each layer is fabricated individually, the ILF process allows the application of mechanical pressure. Thereby, compared to other additive manufacturing techniques, the necessary amount of binder can be significantly reduced and mechanical properties comparable to particle boards can be achieved.
Bulk-surface virtual element method for systems of PDEs in two-space dimensions
Authors: Frittelli Massimo , Madzvamuse Anotida , Sgura Ivonne
Published: January 2021

In this paper we consider a coupled bulk-surface PDE in two space dimensions. The model consists of a PDE in the bulk that is coupled to another PDE on the surface through general nonlinear boundary conditions. For such a system we propose a novel method, based on coupling a virtual element method (Beirão Da Veiga et al. in Math Models Methods Appl Sci 23(01):199–214, 2013. https://doi.org/10.1051/m2an/2013138) in the bulk domain to a surface finite element method (Dziuk and Elliott in Acta Numer 22:289–396, 2013. https://doi.org/10.1017/s0962492913000056) on the surface. The proposed method, which we coin the bulk-surface virtual element method includes, as a special case, the bulk-surface finite element method (BSFEM) on triangular meshes (Madzvamuse and Chung in Finite Elem Anal Des 108:9–21, 2016. https://doi.org/10.1016/j.finel.2015.09.002). The method exhibits second-order convergence in space, provided the exact solution is $$H^{2+1/4}$$

H

2
+
1
/
4

in the bulk and $$H^2$$

H
2

on the surface, where the additional $$\frac{1}{4}$$

1
4

is required only in the simultaneous presence of surface curvature and non-triangular elements. Two novel techniques introduced in our analysis are (i) an $$L^2$$

L
2

-preserving inverse trace operator for the analysis of boundary conditions and (ii) the Sobolev extension as a replacement of the lifting operator (Elliott and Ranner in IMA J Num Anal 33(2):377–402, 2013. https://doi.org/10.1093/imanum/drs022) for sufficiently smooth exact solutions. The generality of the polygonal mesh can be exploited to optimize the computational time of matrix assembly. The method takes an optimised matrix-vector form that also simplifies the known special case of BSFEM on triangular meshes (Madzvamuse and Chung 2016). Three numerical examples illustrate our findings.
Improvements in identification and quantitation of alkylated PAHs and forensic ratio sourcing
Authors: Ghetu Christine C. , Scott Richard P. , Wilson Glenn , Liu-May Rachel , Anderson Kim A.
Published: January 2021

Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) are present in a number of different sources in varying proportions depending on the source material and weathering. This range of PAH sources can make it difficult to determine the origin of exposure(s). Ratios of alkylated and parent PAHs have been applied as a forensic tool to distinguish between different sources. However, few studies have examined PAH ratios comprehensively as indicators for sourcing beyond a single study area or matrix type. In this paper, we introduce an expanded analytical method based on ASTM D7363-13a which we adapted for a gas chromatography triple quadrupole mass spectrometry instrument. The modifications increase selectivity and sensitivity compared to the ASTM method. We added five alkylated series to the method. This method has then been applied to 22 independent forensic ratios. We evaluated the method and the forensic ratios with certified reference materials and known environmental samples. This analytical method and thirteen PAH ratios were found to accurately predict sources of PAHs.

Graphical abstract
Extrapolation of pharmacokinetics and pharmacodynamics of sunitinib in children with gastrointestinal stromal tumors
Authors: Khosravan Reza , DuBois Steven G. , Janeway Katherine , Wang Erjian
Published: January 2021

Purpose

The starting dose of sunitinib in children with gastrointestinal stromal tumors (GIST) was extrapolated based on data in adults with GIST or solid tumors and children with solid tumors.

Methods

Integrated population pharmacokinetics (PK), PK/pharmacodynamics (PD), and exposure–response analyses using nonlinear mixed-effects modeling approaches were performed to extrapolate PK and PD of sunitinib in children with GIST at projected dose(s) with plasma drug exposures comparable to 50-mg/day in adults with GIST. The analysis datasets included PK/PD data in adults with GIST and adults and children with solid tumors. The effect of covariates on PK and safety/efficacy endpoints were explored.

Results

Two-compartment models with lag time were successfully used to describe the PK of sunitinib and its active metabolite SU012662. PK/PD models were successfully built to describe key continuous safety and efficacy endpoints. The effect of age on sunitinib apparent clearance (CL/F) and body surface area on SU012662 CL/F was statistically significant (P ≤ 0.001): children who were younger or of smaller body size had lower CL/F; however, age and body size did not appear to negatively affect safety or efficacy response to plasma drug exposure.

Conclusion

Based on PK, safety, and efficacy trial simulations, a sunitinib starting dose of ~ 25 mg/m2/day was predicted to provide comparable plasma drug exposures in children with GIST as in adults with GIST treated with 50 mg/day. However, in the absence of a tumor type effect of sunitinib on CL/F in children, the projected equivalent dose for this population would be ~ 20 mg/m2/day.
Radiological differences between chronic thromboembolic pulmonary disease (CTEPD) and chronic thromboembolic pulmonary hypertension (CTEPH)
Authors: Capone Carmine , Valentini Adele , Spinillo Silvia Lina , Klersy Catherine , Celentano Anna , Pin Maurizio , Monterosso Cristian , Dore Roberto , Bassi Emilio Maria , Zacchino Michela , Rodolico Giuseppe , Corsico Angelo Guido , Preda Lorenzo , Ghio Stefano , D’Armini Andrea Maria
Published: January 2021

Objectives

The aim of this study was to describe the radiological features of chronic thromboembolic pulmonary disease (CTEPD), not yet systematically described in the literature. Furthermore, we compared vascular scores between CTEPD and chronic thromboembolic pulmonary hypertension (CTEPH) patients, trying to explain why pulmonary hypertension does not develop at rest in CTEPD patients.

Methods

Eighty-five patients (40 CTEPD, 45 CTEPH) referred to our centre for pulmonary endarterectomy underwent dual-energy computed tomography pulmonary angiography (DE-CTPA) with iodine perfusion maps; other 6 CTEPD patients underwent single-source CTPA. CT scans were reviewed independently by an experienced cardiothoracic radiologist and a radiology resident to evaluate scores of vascular obstruction, hypoperfusion and mosaic attenuation, signs of pulmonary hypertension and other CT features typical of CTEPH.

Results

Vascular obstruction burden was similar in the two groups (p = 0.073), but CTEPD patients have a smaller extension of perfusion defects in the iodine map (p = 0.009) and a smaller number of these patients had mosaic attenuation (p < 0.001) than CTEPH patients, suggesting the absence of microvascular disease. Furthermore, as expected, the two groups were significantly different considering the indirect signs of pulmonary hypertension (p < 0.001).

Conclusions

CTEPD and CTEPH patients have significantly different radiological characteristics, in terms of signs of pulmonary hypertension, mosaic attenuation and iodine map perfusion extension. Importantly, our results suggest that the absence of peripheral microvascular disease, even in presence of an important thrombotic burden, might be the reason for the absence of pulmonary hypertension in CTEPD.

Key Points

• CTEPD and CTEPH patients have significantly different radiological characteristics.

• The absence of peripheral microvascular disease might be the reason for the absence of pulmonary hypertension in CTEPD.
Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study
Authors: Kalu Subin , Oyekoya Gboyega Nathaniel , Ambus Per , Tammeorg Priit , Simojoki Asko , Pihlatie Mari , Karhu Kristiina
Published: January 2021

A 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.
Annular Flow in the Upper Esophageal Sphincter Demonstrated with Dynamic 320-row Area Detector Computed Tomography
Authors: Inamoto Yoko , Saitoh Eiichi , Palmer Jeffrey B.
Published: January 2021

Understanding bolus flow patterns in swallowing (rheology, the study of flow) is fundamental to assessment and treatment of dysphagia. These patterns are complex and poorly understood. A liquid swallow is typically biphasic, including air, so the actual bolus has both liquid and gas phases. We report a novel observation of annular two-phase flow (a ring of liquid around a core of air) as thin liquids passed through the upper esophageal sphincter (UES). Dynamic CT was performed on 27 healthy asymptomatic volunteers swallowing liquid barium in a semi-reclining position. Each subject swallowed 3, 10, and 20 ml of either thin (14 subjects) or thick liquid (13 subjects). Sagittal and axial images were analyzed. Flow patterns in the UES were assessed on cross-sectional images. Annular flow was seen in the majority of subjects with thin liquid but few with thick liquid swallows. The percentage of Annular flow during UES opening was 3 ml 58%, 10 ml 58%, 20 ml 56% in thin and 3 ml 0%, 10 ml 4%, 20 ml 1% in thick. Annular flow was usually observed from the second or third frames after onset of UES opening. The other pattern, Plug flow was seldom seen with thin but was typical with thick liquid swallows. Annular flow was the most common pattern for thin liquids (but not thick liquids) passing through the UES. Annular flow has been defined as a liquid continuum adjacent to the channel wall with a gas continuum (core) in the center of the channel. The two regions are demarcated by a gas–liquid interface. Annular flow is typical for two-phase gas–liquid flow in a vertical or inclined channel. It results from the interaction of viscosity with cohesive and adhesive forces in the two phases. We infer that the difference in flow pattern between thin liquid–air and thick liquid–air boluses resulted from the differing magnitudes of viscous forces.