bluuebunny/crossref_metadata_2025 huggingface dataset:
An image watermark removal method for secure internet of things applications based on federated learning
Authors: Li Hongan , Wang Guanyi , Hua Qiaozhi , Wen Zheng , Li Zhanli , Lei Ting
Published: June 2022

Watermark adding is one of the important means for image security and privacy protection in Internet of things (IOT) applications based on federated learning. It is often inseparable from adversarial training with watermark removal algorithms. The effect of watermark removal algorithms will directly affect the final result of watermark addition. However, the existing watermark removal algorithms have drawbacks such as incomplete image watermark removal, poor image quality after watermark removal, large demand for training data, and incorrect filling, which seriously affects the development of image information security and privacy protection in IOT applications based on federated learning. To solve the above problems, this paper proposes an improved image watermark removal convolutional network model based on deep image prior. First, we improve the U‐Net network model, using six downsamping layers and six deconvolution layers combined with deep image prior method to reduce the loss of details and perceive high‐level features, thereby improving the ability of the network to extract high‐level features of the image. In addition, we design a new type of loss function which is called stair loss, and add L1 loss and perception loss to establish new constraints. In order to verify the effectiveness of our method, a comprehensive experimental comparison was conducted on the public dataset PASCAL VOC 2012 in the same experimental environment with CGAN and the deep prior method. The experimental results show that the improved model combined with the deep image prior method can extract the high‐level feature information and can directly remove the watermark from the picture without pretraining the network, the L1 loss and perceptual loss can better retain the image structure information and speed up the watermark removal of the model, the stair loss corrects the final output more accurately by correcting the output of each layer; our method improves the learning ability of the model, and under the condition of the same training time, the image quality after watermark removal is higher, and the final watermark removal result is better, which is more suitable for distributed structure of IoT application based on federated learning.
Astrocyte–synapse interactions and cell adhesion molecules
Authors: Saint‐Martin Margaux , Goda Yukiko
Published: June 2022

Astrocytes are increasingly gaining attention as a major player in regulating brain functions. Not only are astrocytes important for their supporting roles in maintaining optimal neuronal activity, they also dynamically interact with synapses through their highly ramified morphology to directly influence information processing by the neural circuits and the behaviours that depend on it. Here, we take a close look at astrocyte–synapse interactions involved in the coordination of synaptogenesis and astrocyte maturation in the developing brain through to the contribution of astrocytes in synaptic plasticity in the adult brain, and end with a perspective on astrocyte function in behaviours and diseases. In particular, we focus on the roles of synapse adhesion proteins. While cell adhesion proteins that form a bridge between the presynaptic and the postsynaptic compartments have been extensively studied, recent reports highlighting the striking participation of astrocytic cell adhesion proteins in synapse formation and function underscores the importance of reconsidering the conventional neurocentric view of synaptic adhesive interactions and the underlying logic.
Fisheries‐based approach to disentangle mackerel (Scomber scombrus) migration in the Cantabrian Sea
Authors: Rodríguez‐Basalo Augusto , Punzón Antonio , Ceballos‐Roa Elvira , Jordà Gabriel , González‐Irusta José Manuel , Massutí Enric
Published: June 2022

Mackerel is an important commercial pelagic species present in the western and eastern North Atlantic. The Northeast Atlantic Mackerel (NEAM) stock has its southernmost spawning area mainly located western Iberian Peninsula and southern Biscay. This species performs extensive annual migrations. The present study is focused on the distribution of this species along the Cantabrian Sea, an essential area of the South Spawning Component (SSC), and the environmental drivers that can affect its migration phenology. We have used data from Vessel Monitoring System and Logbooks of the hand line fishery to estimate the catch per unit of effort (CPUE) as a proxy of its distribution and abundance. CPUEs data of fisheries targeting NEAM provided us with a tool to discriminate the most important predictors for both its prespawning and the postspawning behavior. Among the drivers that can affect mackerel migration, we have analyzed wind speed and direction, temperature at surface (SST) and at 200 m depth, chlorophylla, mixed layer depth, upwelling intensity, and the most representative geographical variables: depth, slope of the seafloor, and distance to coast. We used generalize additive models to highlight the predictors most closely related to the phenology of the species and to shape the spatial–temporal abundance of NEAM in the southern Bay of Biscay waters. Temperature and wind speed and direction are the most important factors that affect prespawning and postspawning migration of NEAM SSC and shape its niche tracking leading to a gradual advance of the spawning season.
Soil moisture regulates warming responses of autumn photosynthetic transition dates in subtropical forests
Authors: Fu Yongshuo H. , Li Xinxi , Chen Shouzhi , Wu Zhaofei , Su Jianrong , Li Xing , Li Shuaifeng , Zhang Jing , Tang Jing , Xiao Jingfeng
Published: June 2022

Autumn phenology plays a key role in regulating the terrestrial carbon and water balance and their feedbacks to the climate. However, the mechanisms underlying autumn phenology are still poorly understood, especially in subtropical forests. In this study, we extracted the autumn photosynthetic transition dates (APTD) in subtropical China over the period 2003–2017 based on a global, fine‐resolution solar‐induced chlorophyll fluorescence (SIF) dataset (GOSIF) using four fitting methods, and then explored the temporal–spatial variations of APTD and its underlying mechanisms using partial correlation analysis and machine learning methods. We further predicted the APTD shifts under future climate warming conditions by applying process‐based and machine learning‐based models. We found that the APTD was significantly delayed, with an average rate of 7.7 days per decade, in subtropical China during 2003–2017. Both partial correlation analysis and machine learning methods revealed that soil moisture was the primary driver responsible for the APTD changes in southern subtropical monsoon evergreen forest (SEF) and middle subtropical evergreen forest (MEF), whereas solar radiation controlled the APTD variations in the northern evergreen‐broadleaf deciduous mixed forest (NMF). Combining the effects of temperature, soil moisture and radiation, we found a significantly delayed trend in APTD during the 2030–2100 period, but the trend amplitude (0.8 days per decade) was much weaker than that over 2003–2017. In addition, we found that machine learning methods outperformed process‐based models in projecting APTD. Our findings generate from different methods highlight that soil moisture is one of the key players in determining autumn photosynthetic phenological processes in subtropical forests. To comprehensively understand autumn phenological processes, in‐situ manipulative experiments are urgently needed to quantify the contributions of different environmental and physiological factors in regulating plants' response to ongoing climate change.
A 130‐year global inventory of methane emissions from livestock: Trends, patterns, and drivers
Authors: Zhang Lei , Tian Hanqin , Shi Hao , Pan Shufen , Chang Jinfeng , Dangal Shree R. S. , Qin Xiaoyu , Wang Siyuan , Tubiello Francesco N. , Canadell Josep G. , Jackson Robert B.
Published: June 2022

Livestock contributes approximately one‐third of global anthropogenic methane (CH4) emissions. Quantifying the spatial and temporal variations of these emissions is crucial for climate change mitigation. Although country‐level information is reported regularly through national inventories and global databases, spatially explicit quantification of century‐long dynamics of CH4 emissions from livestock has been poorly investigated. Using the Tier 2 method adopted from the 2019 Refinement to 2006 IPCC guidelines, we estimated CH4 emissions from global livestock at a spatial resolution of 0.083° (~9 km at the equator) during the period 1890–2019. We find that global CH4 emissions from livestock increased from 31.8 [26.5–37.1] (mean [minimum−maximum of 95% confidence interval) Tg CH4 yr−1 in 1890 to 131.7 [109.6–153.7] Tg CH4 yr−1 in 2019, a fourfold increase in the past 130 years. The growth in global CH4 emissions mostly occurred after 1950 and was mainly attributed to the cattle sector. Our estimate shows faster growth in livestock CH4 emissions as compared to the previous Tier 1 estimates and is ~20% higher than the estimate from FAOSTAT for the year 2019. Regionally, South Asia, Brazil, North Africa, China, the United States, Western Europe, and Equatorial Africa shared the majority of the global emissions in the 2010s. South Asia, tropical Africa, and Brazil have dominated the growth in global CH4 emissions from livestock in the recent three decades. Changes in livestock CH4 emissions were primarily associated with changes in population and national income and were also affected by the policy, diet shifts, livestock productivity improvement, and international trade. The new geospatial information on the magnitude and trends of livestock CH4 emissions identifies emission hotspots and spatial–temporal patterns, which will help to guide meaningful CH4 mitigation practices in the livestock sector at both local and global scales.
Quantifying Annual Nitrogen Loss to Groundwater Via Edge‐of‐Field Monitoring: Method and Application
Authors: Cardiff Michael , Schachter Laura , Krause Jake , Gotkowitz Madeline , Austin Brian
Published: June 2022

Increased nitrate concentrations in groundwater and surface waters represent one of the most widespread and acute impacts of modern agriculture on the environment. However, there is often a fundamental gap in understanding how individual agricultural fields and practices contribute to this broad‐scale issue. To practically address nutrient dynamics at individual agricultural sites, methods for assessing nitrogen loss to groundwater that are minimally invasive and thus can encourage farmer “buy in” are necessary. We present an approach that uses edge‐of‐field monitoring at multilevel samplers along with a once‐per‐year tracer application (bromide) to calculate nitrogen loss on an annual basis. Using appropriate spatio‐temporal integrals of measured concentrations, a net loss of nitrogen to groundwater (per field area) can be calculated. This approach directly measures impacts of nitrogen leaching below the water table, while avoiding permanent in‐field installations that can interfere with farm operations. We present an application of this technique to assess nitrogen loss to groundwater over 5 years for a commercial agricultural field in Sauk County, WI. Results from Field 19 indicate that nitrogen losses are similar to (or slightly below) previously reported values for corn and potato crops. In all years, however, we estimate that more than 25% (>60 kg/ha) of nitrogen applied leached as nitrate to groundwater. Use of this mass flux estimation method was most reliable when: (1) tracer is injected directly at the water table, limiting “smearing” within the vadose zone; and (2) nitrate concentrations from laboratory analysis were obtained, rather than using ion‐selective electrodes or nitrate test strips.
Crop visitation by wild bees declines over an 8‐year time series: A dramatic trend, or just dramatic between‐year variation?
Authors: Aldercotte Andrew H. , Simpson Dylan T. , Winfree Rachael
Published: June 2022

Despite widespread recognition of the need for long‐term monitoring of pollinator abundances and pollination service provision, such studies are exceedingly rare.

In this study, we assess changes in bee visitation and net capture rates for 73 species visiting watermelon crop flowers at 19 farms in the mid‐Atlantic region of the United States from 2005 to 2012.

Over the 8 years, we found a 58% decline in wild bee visitation to crop flowers, but no significant change in honey bee visitation rate. Most types of wild bees showed similar declines in both the visitation and the net capture data; bumble bees, however, declined by 56% in the visitation data but showed no change in net capture rates. Trends in pollination services, that is, estimated pollen deposition, largely followed the trends in visitation and net capture rates.

While we detected large and significant declines in wild bees when using generalised linear mixed models (GLMMs), permutation analyses that account for non‐directional variation in abundance were non‐significant, demonstrating the challenge of identifying and describing trends in highly variable populations.

As far as we are aware, this article represents one of fewer than 10 published time‐series (defined as >5 years of data) studies of changes in bee abundance, and one of only two such studies conducted in an agricultural setting. More such studies are needed in order to understand the magnitude of bee decline and its ramifications for crop pollination.
Large contribution of woody plant expansion to recent vegetative greening of the Northern Great Plains
Authors: Currey Bryce , McWethy David B. , Fox Nicholas R. , Brookshire E. N. Jack
Published: June 2022

Aim

Extensive portions of high‐latitude grasslands worldwide have recently experienced increased vegetative productivity (i.e., greening) and have undergone a rapid transition towards woody plant dominance via the process of woody plant expansion (WPE). This raises the underlying question: To what degree are WPE and greening spatiotemporally linked? Given that these vegetative changes are predicted to continue, we seek to understand how recent changes in vegetation extent and productivity have interacted under recent climate change and anthropogenic disturbance to provide insights surrounding the future trajectory of temperate grasslands broadly.

Location

Northern Great Plains (NGP), North America.

Taxon

Woody plants.

Methods

Greening was measured as the significant increase in three metrics between 2000 and 2019: leaf area index (LAI), annual maximum normalized difference vegetative index (NDVI) and annual mean NDVI. WPE was measured as the significant proportional increase in percent tree cover change between 2000 and 2019 in grasslands. We then examined these variables across a host of 26 potential driving variables.

Results

We show that average proportional greening increased by 0.2–1.3% year−1 (depending on metric), and proportional WPE increased by 6.9% year−1 since 2000 across the NGP. Both changes are largely driven by the absence of wildfire and changing climate. Furthermore, WPE was spatially coherent and positively associated with a large component of recent greening, as revealed by their coupling across 34.1%–40.6% of grassland area and as evidenced by the 9.7%–19.7% of the variability in greening explained by WPE.

Main conclusions

WPE and greening are spatiotemporally coupled across large portions of the NGP. Under continued climate change and wildfire suppression, WPE and greening are likely to continue across large swathes of grasslands globally. Furthermore, our results show that using a single greening metric may be insufficient to capture the large‐scale vegetative changes such as the expansion of woody vegetation.
Recommendations for outcome measurement for deprescribing intervention studies
Authors: Bayliss Elizabeth A. , Albers Kathleen , Gleason Kathy , Pieper Lisa E. , Boyd Cynthia M. , Campbell Noll L. , Ensrud Kristine E. , Gray Shelly L. , Linsky Amy M. , Mangin Derelie , Min Lillian , Rich Michael W. , Steinman Michael A. , Turner Justin , Vasilevskis Eduard E. , Dublin Sascha
Published: June 2022

Interpreting results from deprescribing interventions to generate actionable evidence is challenging owing to inconsistent and heterogeneous outcome definitions between studies. We sought to characterize deprescribing intervention outcomes and recommend approaches to measure outcomes for future studies. A scoping literature review focused on deprescribing interventions for polypharmacy and informed a series of expert panel discussions and recommendations. Twelve experts in deprescribing research, policy, and clinical practice interventions participating in the Measures Workgroup of the US Deprescribing Research Network sought to characterize deprescribing outcomes and recommend approaches to measure outcomes for future studies. The scoping review identified 125 papers reflecting 107 deprescribing studies. Common outcomes included medication discontinuation, medication appropriateness, and a broad range of clinical outcomes potentially resulting from medication reduction. Panel recommendations included clearly defining clinically meaningful medication outcomes (e.g., number of chronic medications, dose reductions), ensuring adequate sample size and follow‐up time to capture clinical outcomes resulting from medication discontinuation (e.g., quality of life [QOL]), and selecting appropriate and feasible data sources. A new conceptual model illustrates how downstream clinical outcomes (e.g., reduction in falls) should be interpreted in the context of initial changes in medication measures (e.g., reduction in mean total medications). Areas needing further development include implementation outcomes specific to deprescribing interventions and measures of adverse drug withdrawal events. Generating evidence to guide deprescribing is essential to address patient, caregiver, and clinician concerns about the benefits and harms of medication discontinuation. This article provides recommendations and an initial conceptual framework for selecting and applying appropriate intervention outcomes to support deprescribing research.
Urban form and scale shaped the agroecology of early ‘cities’ in northern Mesopotamia, the Aegean and Central Europe
Authors: Styring Amy K. , Carmona Chris U. , Isaakidou Valasia , Karathanou Angeliki , Nicholls Geoff K. , Sarpaki Anaya , Bogaard Amy
Published: June 2022

Agricultural extensification refers to an expansive, low‐input production strategy that is land rather than labour limited. Here, we present a robust method, using the archaeological proxies of cereal grain nitrogen isotope values and settlement size, to investigate the relationship between agricultural intensity and population size at Neolithic to Bronze/Iron Age settlement sites in northern Mesopotamia, the Aegean and south‐west Germany. We conclude that urban form—in particular, density of occupation—as well as scale shaped the agroecological trajectories of early cities. Whereas high‐density urbanism in northern Mesopotamia and the Aegean entailed radical agricultural extensification, lower density urbanism in south‐west Germany afforded more intensive management of arable land. We relate these differing agricultural trajectories to long‐term urban growth/collapse cycles in northern Mesopotamia and the Aegean, on the one hand, and to the volatility of early Iron Age elite power structures and urban centralization in south‐west Germany, on the other.
Evolutionary targets of gene expression divergence in a complex of closely related pine species
Authors: Zaborowska Julia , Perry Annika , Cavers Stephen , Wachowiak Witold M.
Published: June 2022

The environment is a powerful selective pressure for sessile organisms, such as plants, and adaptation to the environment is particularly important for long‐lived species, like trees. Despite the importance of adaptive trait variation to the survival and success of trees, the molecular basis of adaptation is still poorly understood. Gene expression patterns in three closely related, but phenotypically and ecologically divergent, pine species were analyzed to detect differentiation that may be associated with their adaptation to distinct environments. Total RNA of Pinus mugo, Pinus uncinata, and Pinus sylvestris samples grown under common garden conditions was used for de novo transcriptome assembly, providing a new reference dataset that includes species from the taxonomically challenging P. mugo complex. Gene expression profiles were found to be very similar with only 121 genes significantly diverged in any of the pairwise species comparisons. Functional annotation of these genes revealed major categories of distinctly expressed transcripts, including wood trait properties, oxidative stress response, and response to abiotic factors such as salinity, drought, and temperature. We discuss putative associations between gene expression profiles and adaptation to different environments, for example, the upregulation of genes involved in lignin biosynthesis in the species, which have adapted to mountainous regions characterized by strong winds and thick snow cover. Our study provides valid candidates for verification of the importance of the gene expression role, in addition to evidence for selection within genomic regions, in the process of ecological divergence and adaptation to higher altitudes in pine taxa.
Historical account of dwindling national flexibilities from the Paris Convention to post‐TRIPS era: What implications for access‐to‐medicines in low‐and‐middle‐income‐countries?
Authors: Olatunji Olugbenga A.
Published: June 2022

It is arguable that the most significant feature of the maiden Paris Convention is the creation of a remarkably broad national policy space which allowed Union members to balance the implementation of required obligations with the need to occasionally attend to national exigencies. Thus, a member may choose not to offer industrial property protection if national interests would be best served by doing so. While subsequent revisions to the Paris Convention chipped away at national flexibilities, the most strident attack to national flexibilities occurs under the Agreement for the Trade‐Related Aspects of Intellectual Property Rights and the period after it. This paper puts the almost‐unnoticed whittling down of national flexibilities in international patent agreements in historical perspective. It subsequently discusses four ways through which this development could exacerbate access‐to‐medicines in low‐and‐middle‐income‐countries.
From the Heterogeneity Problem to a Natural‐Kind Approach to Pleasure
Authors: Broi Antonin
Published: June 2022

The heterogeneity problem, which stems from the alleged difficulty of finding out what all pleasant experiences have in common, is largely considered as a substantial issue in the philosophy of pleasure, one that is usually taken as the starting point for theorizing about the essence of pleasure. The goal of this paper is to move the focus away from the heterogeneity problem and toward an alternative approach to pleasure. To do this, I first show that, although the approach stemming from the heterogeneity problem has led to an interesting discussion about the essence of pleasure, it has usually endorsed an introspectionist methodology and other problematic assumptions that have led to doubtful results. I thus propose a natural‐kind approach to pleasure, which seeks to determine what, if any, the natural kind of pleasure would consist in. This approach broadens the investigation of pleasure by enabling the use of a larger range of methodological tools, thus opening new promising directions for research.
Natural allelic variation ofGmST05controlling seed size and quality in soybean
Authors: Duan Zongbiao , Zhang Min , Zhang Zhifang , Liang Shan , Fan Lei , Yang Xia , Yuan Yaqin , Pan Yi , Zhou Guoan , Liu Shulin , Tian Zhixi
Published: June 2022

Seed size is one of the most important agronomic traits determining the yield of crops. Cloning the key genes controlling seed size and pyramiding their elite alleles will facilitate yield improvement. To date, few genes controlling seed size have been identified in soybean, a major crop that provides half of the plant oil and one quarter of the plant protein globally. Here, through a genome‐wide association study of over 1800 soybean accessions, we determined that natural allelic variation atGmST05(Seed Thickness 05) predominantly controlled seed thickness and size in soybean germplasm. Further analyses suggested that the two major haplotypes ofGmST05differed significantly at the transcriptional level. Transgenic experiments demonstrated thatGmST05positively regulated seed size and influenced oil and protein contents, possibly by regulating the transcription ofGmSWEET10a. Population genetic diversity analysis suggested that allelic variations ofGmST05were selected during geographical differentiation but have not been fixed. In summary, natural variation inGmST05determines transcription levels and influences seed size and quality in soybean, making it an important gene resource for soybean molecular breeding.
Risk factors and incidence of cytomegalovirus viremia and disease in pediatric patients with allogeneic hematopoietic stem cell transplantation: An 8‐year single‐center experience in Latin America
Authors: Aristizabal Ana M. , Perez Paola , Patiño Niño Jaime A. , Franco Alexis , Tarapues Eliana Manzi , Beltran Estefania , Medina Diego
Published: June 2022

Background

Cytomegalovirus infection represents a significant cause of morbidity and mortality after hematopoietic stem cell transplantation. This study aimed to evaluate the incidence of viremia and disease due to cytomegalovirus and the risk factors in pediatric patients with hematopoietic stem cell transplantation in our institution.

Methods

This was a retrospective cohort of patients under 19 years of age who underwent allogeneic hematopoietic stem cell transplantation due to any indication between 2012 and 2019. The analysis included the diagnosis of cytomegalovirus viremia or disease during post‐transplant follow‐up, evaluation of risk factors, and outcomes. The statistical analysis included univariate and multivariate analyses, and the cumulative incidence of cytomegalovirus viremia was determined by the Kaplan–Meier method using STATA 14 statistical software.

Results

A total of 182 transplants were included. At 100 days, the cumulative incidence of cytomegalovirus viremia was 70.5%, and that of cytomegalovirus disease was 4.7%. Overall survival at 2 years was 74%, and event‐free survival was 64%. The remaining demographic characteristics were not predictors of infection. There was no association between viremia and relapse or survival of the patients. Higher mortality was noted in cytomegalovirus disease.

Conclusions

During the study period, the incidence of cytomegalovirus disease was similar to that of other pediatric reports, but the incidence of viremia was higher. Pre‐emptive therapy has diminished disease rates and death due to infection. Viral load cutoff points should be standardized to guide treatment and avoid myelotoxicity.
Executive leadership, policy tourism, and policy diffusion among local governments
Authors: Yi Hongtao , Liu Ivy
Published: June 2022

Policy tourism is an important but rarely studied phenomenon describing a widespread practice, through which local public and business leaders form delegations, choose target cities, and implement intercity policy diffusion, business exchange, and economic collaboration. Our research examines how executive leadership characteristics, city‐level contextual factors, and interdependence mechanisms relate to cities' decisions to visit. Using two‐stage probit selection models with instrumental variables on a dyadic balanced panel dataset recording all policy tourism events between major U.S. cities from 2007 to 2016, we answer this question accounting for potential endogeneity problems. Our findings suggest that cities with experienced yet newly appointed, minority leaders tend to visit cities with experienced white or female leaders. Additionally, policy tourism happens among cities embedded in highly complex, munificent, and turbulent environments. Finally, cities tend to learn from peers with higher economic prosperity or interact with their competitors.
Use of hepatitis B viremic donors in kidney transplant recipients: A single center experience
Authors: Carnemolla Brooke T. , Kutzler Heather L. , Kuzaro Hillary A. , Morgan Glyn , Serrano Oscar K. , Ye Xiaoyi , Cheema Faiqa
Published: June 2022

Utilization of Hepatitis B virus (HBV)‐infected kidney allografts represents an opportunity to bridge the gap between organ supply and demand. Highly efficacious vaccines and antiviral therapies allow these allografts to be transplanted with negligible risk to the recipient. The purpose of this study was to describe the prophylactic strategies and related clinical outcomes of kidney transplant recipients who received a kidney from an HBV viremic donor. Eight patients received an allograft from an HBV viremic deceased kidney donor between January 1, 2017 and December 4, 2020. All recipients were immune to hepatitis B with a surface antibody titer greater than or equal to 10 mIU/ml (range: 12 ‐ > 1000 mIU/ml). After transplant, 62.5% demonstrated HBV core antibody seroconversion at an average of 47.4 ± 28.5 days post‐transplant. Anti‐viral prophylaxis was initiated in 87.5% of patients; 62.5% preemptively during the transplant admission (range 1–3 days post‐transplant) and 25% following HBcAb seroconversion (range 45–304 days post‐transplant). Of the four patients who were started on entecavir preemptively, two subsequently core converted. These two patients had an HBV surface antibody less than 100 mIU/ml at the time of transplant. None of the recipients converted to HBV surface antigen positivity. The average estimated glomerular filtration rate was 41 ± 19 ml/min/1.73m2, and there were no significant elevations in liver enzymes through one year post‐transplant. The use of HBV viremic kidney allografts may represent an additional source of transplant organs; however, more studies are needed to better elucidate the optimal protective strategies for these recipients.

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The evolution of extremely diverged plastomes in Selaginellaceae (lycophyte) is driven by repeat patterns and the underlying DNA maintenance machinery
Authors: Xiang Qiao‐Ping , Tang Jun‐Yong , Yu Ji‐Gao , Smith David Roy , Zhu Yan‐Mei , Wang Ya‐Rong , Kang Jong‐Soo , Yang Jie , Zhang Xian‐Chun
Published: June 2022

Two factors are proposed to account for the unusual features of organellar genomes: the disruptions of organelle‐targeted DNA replication, repair, and recombination (DNA‐RRR) systems in the nuclear genome and repetitive elements in organellar genomes. Little is known about how these factors affect organellar genome evolution. The deep‐branching vascular plant family Selaginellaceae is known to have a deficient DNA‐RRR system and convergently evolved organellar genomes. However, we found that the plastid genome (plastome) of Selaginella sinensis has extremely accelerated substitution rates, a low GC content, pervasive repeat elements, a dynamic network structure, and it lacks direct or inverted repeats. Unexpectedly, its organelle DNA‐RRR system is short of a plastid‐targeted Recombinase A1 (RecA1) and a mitochondrion‐targeted RecA3, in line with other explored Selaginella species. The plastome contains a large collection of short‐ and medium‐sized repeats. Given the absence of RecA1 surveillance, we propose that these repeats trigger illegitimate recombination, accelerated mutation rates, and structural instability. The correlations between repeat quantity and architectural complexity in the Selaginella plastomes support these conclusions. We, therefore, hypothesize that the interplay of the deficient DNA‐RRR system and the high repeat content has led to the extraordinary divergence of the S. sinensis plastome. Our study not only sheds new light on the mechanism of plastome divergence by emphasizing the power of cytonuclear integration, but it also reconciles the longstanding contradiction on the effects of DNA‐RRR system disruption on genome structure evolution.
Rolling Bearing Damage Evaluation by the Dynamic Process From Self-Induced Resonance to System Resonance of a Duffing System
Authors: Zhang Shuai , Wang Zhongqiu , Yang Jianhua
Published: June 2022

The dynamic response of a Duffing system from self-induced resonance to system resonance is studied in this paper. From numerical simulation, it is found that the system response gradually transits from self-induced resonance to system resonance with the increase of the pulse amplitude of the signal. In order to describe this process, we define the quality factor of the system response. With the evolution from self-induced resonance to system resonance, the quality factor gradually increases from 0 to 1. Then, based on the evolution, a novel method is developed to evaluate the severity of rolling bearing early damage. The results show that the method can be used not only to describe the process of a rolling bearing from healthy to damaged, but also to evaluate the severity of the early damage of a rolling bearing. The quality factor is a key index to reflect the severity of a rolling bearing. In addition, the sensitivity of the quality factor is superior to other traditional indices formerly used in the early damage evaluation. The effective method gives a new way for rolling bearing early damage evaluation.
Hybrid Monte Carlo-Diffusion Studies of Modeling Self-Heating in Ballistic-Diffusive Regime for Gallium Nitride HEMTs
Authors: Li Han-Ling , Shen Yang , Hua Yu-Chao , Sobolev S. L. , Cao Bing-Yang
Published: June 2022

Exact assessment of self-heating is of great importance to the thermal management of electronic devices, especially when completely considering the cross-scale heat conduction process. The existing simulation methods are either based on convectional Fourier's law or limited to small system sizes, making it difficult to deal with noncontinuum thermal transport efficiently. In this paper, a hybrid phonon Monte Carlo diffusion method is adopted to predict device temperature in ballistic–diffusive regime. Heat conduction around the heat generation region and boundaries are simulated by phonon Monte Carlo (MC) method, while the other domain is by Fourier's law. The temperature of the hybrid method is higher than that of Fourier's law owing to phonon ballistic transport, and the calculation efficiency of the hybrid method is remarkably improved compared with phonon MC simulation. Furthermore, the simulation results indicate that the way of modeling self-heating has a remarkable impact on phonon transport. The junction temperature of the heat source (HS) scheme can be larger than that of the heat flux (HF) scheme, which is opposite to the result under Fourier's law. In the HS scheme, the enhanced phonon-boundary scattering counteracts the broadening of the heat source, leading to a stronger ballistic effect and higher temperatures. The conclusion is verified by a one-dimensional analytical model. This work has opened up an opportunity for the fast and extensive thermal simulations of cross-scale heat transfer in electronic devices and highlighted the influence of heating schemes.
Modeling the Performance of Fuzzy Expert System for Prediction of Combustion, Engine Performance, and Exhaust Emission Parameters of a Spark Ignition Engine Fueled With Waste Bread Bioethanol-Gasoline Blends
Authors: Yasar Ali , Kul Bahar Sayin , Ciniviz Murat
Published: June 2022

This article focuses on the use of a rule-based Mamdani-type fuzzy expert system for the prediction of Pmax, HRRmax, ID, and CD as combustion parameters, BTE and BSFC as engine performance parameters, and CO, CO2, HC, and NOx as exhaust emission parameters of fuel blends formed by blending waste bread bioethanol with gasoline in different proportions. For modeling of 55 test conditions created by being operated test engine with 11 different test fuels under five different engine loads. As a result of the study, while combustion parameters were predicted with correlation coefficients in the range of 0.948–0.973% for waste bread bioethanol-gasoline blends, correlation coefficients for engine performance and exhaust emission parameters were in the range of 0.968–0.977% and 0.955–0.991% respectively. Similarly, the ranges of correlation coefficients obtained for sugar beet bioethanol-gasoline blends with fuzzy expert system were as follows: 0.967–0.971% for engine performance parameters, 0.955–0.978% for exhaust emission parameters, and 0.951–0.964% for combustion parameters. These results prove that costly and labor-intensive engine tests can be predicted with minimum effort and high accuracy with the developed model.
A Novel Trajectory-Based Mechanistic Model for Predicting Solid Particle Erosion in Elbows
Authors: Darihaki Farzin , Zhang Jun , Shirazi Siamack A. , McLaury Brenton S.
Published: June 2022

Solid particle erosion is a common and challenging phenomenon during the production and transport of particle-containing fluids and it is important to have models for predicting erosion rates accurately, especially for geometries such as elbows. Mechanistic models aim at predicting erosion accurately with low computational cost. In this study, a new particle trajectories-based mechanistic model is proposed to address the issues of liquid-dominated flows and the effect of particle size. Detailed flow and particle information for a standard elbow with water and air and different particle sizes are extracted from computational fluid dynamics (CFD) and analyzed to obtain a representative trajectory. The developed model includes various components that are sensitive to the particle size and flow conditions and accounts for the angle of impact and the turbulence in the flow. The proposed model is examined against CFD predictions for different pipe and particle sizes, and velocities with air, water, high-pressure air, and high-viscosity liquid. In comparison to an available mechanistic model, the new model provides relatively lower errors in predicting maximum erosion for many flow conditions. Moreover, the proposed model is found to be more consistent with CFD data for high-pressure air and higher-viscosity liquids. The model is further validated with experimental data for various conditions. Comparisons against numerical and experimental data suggest that the proposed model provides a significant improvement for liquid–solid flows and small particles.
Experimental Study on Water-Plugging Performance of Silicon Dioxide/Polystyrene Hydrophobic Insoluble Microsphere Particle Flooded by High-Water-Cut Oil–Water Mixture
Authors: Zheng Liming , Wang Hao , Zhang Yangyang , Wang Yu , Li Yanlin
Published: June 2022

Water plugging was an important but difficult process close to high-water-cut production wells. The injected water-plugging materials were usually liquid and typically had been evaluated by conventional water-flooding experiments. In this study, silicon dioxide (SiO2)/polystyrene hydrophobic insoluble microsphere particles were introduced as a selective water shutoff agent, and the water-saturated core was flooded with a high-water-cut oil–water mixture. Indexes such as modified oil-coning time, water-cut fluctuation, and cumulative water cut were proposed to evaluate water-plugging capability. A parametric study was conducted to evaluate the influence of particle composition (A, SiO2/polystyrene particle; B, complete polystyrene particle), water cut of the injected oil–water mixture, and preheating temperature of the insoluble particles on water-plugging performance. The results from the index analysis and relative permeability curve showed that the proposed indexes could be used to compare water-plugging performance during oil–water mixture drive; both particles had better water-plugging performance when the injected mixture was not an ultrahigh water cut (fw < 90%). Particle B had larger lipophilicity and stronger capacity for decreasing the water cut (about 0.55–1.28%) at a conventional temperature when the oil–water mixture of the injected fluid had a water cut of 90%. Particle A had lower capacity to decrease the water cut (by about −0.94–0.26%), but it was resistant to reservoir temperature because of its dense structure and the addition of SiO2. These results provided suggestions for the application of hydrophobic insoluble microsphere particles in water plugging in production wells.
Propagation of nanosecond plasmas in liquids—Streamer velocities and streamer lengths
Authors: Jüngling E. , Grosse K. , von Keudell A.
Published: June 2022

Nanosecond plasmas in liquids are often generated by applying a short high voltage pulse to an electrode immersed in a liquid for biomedical or environmental applications. The plasmas appear as streamers that propagate through the liquid. The understanding of the ignition of these nanosecond plasmas in liquids, however, is an open question. The occurrence of any traditional gas phase ignition mechanism is unlikely, because the formation of a gas bubble prior to ignition is suppressed by the inertia of the liquid. Therefore, either electron multiplication inside nanopores that are induced by an electric field pressure gradient or field effects at the tip and at the ionization front of the liquid streamer may act as electron generation mechanisms. A deeper understanding can be achieved by comparing the velocity and dynamic of the plasma propagation with modeling, where the individual mechanisms and transport coefficients can be analyzed. Here, we are using intensified charge-coupled device imaging to investigate the time dependence of the streamer dynamic and compare this with a 1D fluid code for negative voltages. It is shown that the maximum streamer length scales with the applied electric field, indicating that an electric stability field in the liquid streamer channel is important, as known for gas streamers. The 1D fluid code can reproduce the proper streamer velocities, if transport coefficients for hydrated electrons are chosen. The model suggests that the propagation of liquid streamers is dominated by the local ionization rate at the ionization front rather than by advection or diffusion of electrons as in gases. This also explains the finding that positive and negative streamers exhibit almost identical electron densities.
R. L. Pritchard's classic mutual impedance contribution
Authors: Butler John L.
Published: June 2022

The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.
Investigation on whistle directivity in the Indo-Pacific humpback dolphin (Sousa chinensis) through numerical modeling
Authors: Song Zhongchang , Zhang Chuang , Fu Weijie , Gao Zhanyuan , Ou Wenzhan , Zhang Jinhu , Zhang Yu
Published: June 2022

Odontocetes have evolved special acoustic structures in the forehead to modulate echolocation and communication signals into directional beams to facilitate feeding and social behaviors. Whistle directivity was addressed for the Indo-Pacific humpback dolphin (Sousa chinensis) by developing numerical models in the current paper. Directivity was first examined at the fundamental frequency 5 kHz, and simulations were then extended to the harmonics of 10, 15, 20, 25, and 30 kHz. At 5 kHz, the –3 dB beam widths in the vertical and horizontal planes were 149.3° and 119.4°, corresponding to the directivity indexes (DIs) of 4.4 and 5.4 dB, respectively. More importantly, we incorporated directivity of the fundamental frequency and harmonics to produce an overall beam, resulting in −3 dB beam widths of 77.2° and 62.9° and DIs of 8.2 and 9.7 dB in the vertical and horizontal planes, respectively. Harmonics can enhance the directivity of fundamental frequency by 3.8 and 4.3 dB, respectively. These results suggested the transmission system can modulate whistles into directional projection, and harmonics can improve DI.
Equivalent circuit for analyzing the transmitting characteristics of multimode Tonpilz transducer
Authors: Pyo Seonghun , Roh Yongrae
Published: June 2022

Multimode Tonpilz transducers operate at longitudinal and flexural vibration modes simultaneously. Consequently, they have wider bandwidths than conventional single-mode transducers. Generally, the performance of Tonpilz transducers is analyzed using the finite element method (FEM), whereas the equivalent circuit method (ECM) has proven to be a fast and efficient alternative to the FEM. However, the ECM for analyzing the acoustic characteristics of multimode Tonpilz transducers has not yet been developed. To address this issue, an equivalent circuit for the multimode Tonpilz transducer is developed herein. The proposed ECM encompasses the flexural characteristics of the Tonpilz head mass, which is impossible with conventional equivalent circuits. Furthermore, a prototype of the multimode Tonpilz transducer was fabricated to verify the validity of the developed ECM. Additionally, the accuracy and compliance of the ECM were confirmed by comparing the measured performance of the transducer with that from the equivalent circuit analysis.
Nonlinear characteristics of high amplitude focusing using time reversal in a reverberation chamber
Authors: Patchett Brian D. , Anderson Brian E.
Published: June 2022

Time reversal (TR) signal processing is an effective tool to exploit a reverberant environment for the intentional focusing of airborne, audible sound. A previous room acoustics TR study found preliminary evidence that above a certain focal amplitude the focal waveform begins to display signs of nonlinearity [Willardson, Anderson, Young, Denison, and Patchett, J. Acoust. Soc. Am. 143(2), 696–705 (2018)]. This study investigates that nonlinearity further by increasing the focal peak amplitudes beyond that previously observed. This increases the nonlinear characteristics, allowing for a closer inspection of their properties. An experiment is conducted using eight horn loudspeaker sources and a single receiver in a reverberation chamber. A maximum peak focal amplitude of 214.8 kPa (200.6 dBpk) is achieved. The focus signal waveforms are linearly scaled to observe and characterize the nonlinear amplification of the waveform. Frequency spectra of the peak focal amplitudes are plotted to observe changes in frequency content as the signals become nonlinear. A one-dimensional spatial scan of the focal region is conducted to observe properties of the converging and diverging waves. A proposal for a possible explanation involving free-space Mach stem formation is given.
Experimental verification of the minimum Bhattacharyya distance-based source bearing estimator
Authors: Ma Qian , Cheng Lei , Xu Wen
Published: June 2022

The minimum Bhattacharyya distance estimator (MBDE) for acoustic source bearing estimation was recently proposed as a promising tool to tackle the model mismatch challenge. Previous work lacks the experimental studies using the real-life array system data. Towards the practical use of MBDE, this letter proposes two practical schemes to address the unavailability of noise and source powers, presents the additional simulation results on resolving the closely spaced sources with different strengths, and performs real-world experimental studies using the SwellEx-96 data. Simulation and experimental results demonstrate the superior performance of the MBDE over other competitors.