bluuebunny/crossref_metadata_2025 huggingface dataset:
Concomitant Atrial Fibrillation Procedures During Cardiac Surgery in a UK Center: Reflection of Worldwide Practice?
Authors: Mistirian Alina-Adriana , Yates Martin T. , Awad Wael I.
Published: March 2022

Background

Guidelines recommend concomitant atrial fibrillation (AF) ablation during cardiac surgery to restore normal sinus rhythm (NSR). The study determines, to what extent patients with AF undergoing cardiac surgery at our institution received a concomitant AF procedure, what these procedures entailed, and short-term outcomes.

Methods

A retrospective study of 2,984 patients undergoing cardiac surgery over 18 months. Patients who were in preoperative AF were identified and those who underwent a concomitant AF procedure (Group 1) were compared with those who did not (Group 2).

Results

Three hundred and thirteen (10.5%) patients had pre-operative AF; paroxysmal (19.5%), persistent (11.8%), longstanding (63%), unknown (5.8%). 116/313 (37.1%) patients had a concomitant AF procedure: 7.7% patients had a concomitant AF ablation and 29.4% had only a Left Atrial Appendage Occlusion (LAAO). Fewer patients with paroxysmal and persistent AF underwent concomitant AF procedures compared with the ones who had no AF procedures (6.7 vs. 12.8% and 17.6 vs. 31%, respectively). Greater in-hospital survival (99.1 vs. 93.9%, p = 0.025) and survival at a mean follow up of 6 weeks (97.4 vs. 89.3%, p = 0.09) was probably determined by patient's preoperative comorbidities. There were no differences in readmission rates, permanent pacemaker insertion, cerebral events or NSR at discharge or follow-up, between groups.

Conclusions

In our center, concomitant AF ablation is performed only in 7.7% of cases, 29.4% had only an LAAO performed at the time of surgery. There was no difference in restoring NSR, cerebral events, or readmission rates compared with patients who had nothing done for their preoperative AF.
A Collaborative Approach for the Development and Application of Machine Learning Solutions for CMR-Based Cardiac Disease Classification
Authors: Huellebrand Markus , Ivantsits Matthias , Tautz Lennart , Kelle Sebastian , Hennemuth Anja
Published: March 2022

The quality and acceptance of machine learning (ML) approaches in cardiovascular data interpretation depends strongly on model design and training and the interaction with the clinical experts. We hypothesize that a software infrastructure for the training and application of ML models can support the improvement of the model training and provide relevant information for understanding the classification-relevant data features. The presented solution supports an iterative training, evaluation, and exploration of machine-learning-based multimodal data interpretation methods considering cardiac MRI data. Correction, annotation, and exploration of clinical data and interpretation of results are supported through dedicated interactive visual analytics tools. We test the presented concept with two use cases from the ACDC and EMIDEC cardiac MRI image analysis challenges. In both applications, pre-trained 2D U-Nets are used for segmentation, and classifiers are trained for diagnostic tasks using radiomics features of the segmented anatomical structures. The solution was successfully used to identify outliers in automatic segmentation and image acquisition. The targeted curation and addition of expert annotations improved the performance of the machine learning models. Clinical experts were supported in understanding specific anatomical and functional characteristics of the assigned disease classes.
Comorbidity of Type 2 Diabetes Mellitus and Depression: Clinical Evidence and Rationale for the Exacerbation of Cardiovascular Disease
Authors: Zhu Mengmeng , Li Yiwen , Luo Binyu , Cui Jing , Liu Yanfei , Liu Yue
Published: March 2022

Depression is a common comorbidity of type 2 diabetes mellitus (T2DM). T2DM with comorbid depression increases the risk of cardiovascular events and death. Depression and T2DM and its macrovascular complications exhibited a two-way relationship. Regarding treatment, antidepressants can affect the development of T2DM and cardiovascular events, and hypoglycemic drugs can also affect the development of depression and cardiovascular events. The combination of these two types of medications may increase the risk of the first myocardial infarction. Herein, we review the latest research progress in the exacerbation of cardiovascular disease due to T2DM with comorbid depression and provide a rationale and an outlook for the prevention and treatment of cardiovascular disease in T2DM with comorbid depression.
Quantitative Evaluation and Diagnosis of Water Resources Carrying Capacity (WRCC) Based on Dynamic Difference Degree Coefficient in the Yellow River Irrigation District
Authors: Cui Yi , Zhou Yuliang , Jin Juliang , Wu Chengguo , Zhang Libing , Ning Shaowei
Published: March 2022

In order to effectively deal with the uncertainty between evaluation samples and evaluation criteria, and quantitatively identify the water resources carrying capacity (WRCC) and its obstacle factors in the Yellow River irrigation district, a calculation method of dynamic difference degree coefficient varying with evaluation sample was proposed, and then an evaluation and diagnosis model of WRCC was established. The results applied to the Dagong irrigation district showed that the overall WRCC of five counties in the irrigation district were improved from 2010 to 2017, especially since 2013. The improvement magnitudes of Changyuan County, Fengqiu County, and Hua County were significantly higher than those of Xun County and Neihuang County. In 2017, Fengqiu County, Changyuan County, Hua County, Xun County, and Neihuang County were in water resources critical overloaded status, and the connection number values were 0.231, 0.163, 0.120, −0.293, and −0.331, respectively, which is consistent with the fact that their distances become farther from the main stream of the Yellow River. In addition, the utilization ratio of water resources, available water resources amount per capita, GDP per capita, and water deficient ratio in each county belonged to the middle or strong obstacle index over a long period of time. They were the crucial obstacle factors of WRCC in the Dagong irrigation district, as well as the core and difficult points of water resources management. In some counties, the effective irrigation area ratio, effective utilization coefficient of irrigation water, and water consumption ratio of the ecological environment gradually developed from strong obstacle to weak or strong promotion index. These were important reasons for the improvement of their carrying situation, reflecting their control of agricultural and ecological water consumption. In short, the results of the case study suggest that the model established in this study is conducive to the identification of water resources’ carrying status and its key obstacle factors in the Yellow River irrigation district, and can be applied to the evaluation and regulation of resources and environment carrying capacity.
Diffraction Extraction and Least-Squares Reverse Time Migration Imaging for the Fault-Karst Structure With Adaptive Sampling Strategy
Authors: Chen Liang , Huang Jianping , Song Cheng , Han Jiale
Published: March 2022

The ultra-deep fault-karst structure discovered in the Tarim Basin in Western China is a fractured-vuggy carbonate reservoir with great potential for development. The diffraction generated by fractures, small-scale caves and vugs is often used for reservoir identification and seismic interpretation. Since the diffraction is much weaker than the reflection, it is difficult to separate the diffraction from the full wavefield. We use a plane-wave destruction (PWD) filter to extract the diffraction from the full data. In order to obtain a high-accuracy and amplitude-preserving imaging profile, we use the least-squares reverse time migration (LSRTM) method to image the separated diffraction. The large amount of calculation is the most challenging problem of the LSRTM algorithm. In view of this, we develop an adaptive sampling strategy to improve computing efficiency and reduce memory requirement. We use a fault model, a vugs-fractures model, and a fault-karst model to demonstrate the effectiveness and practicability of the proposed method. The numerical examples show that the proposed method can enhance the imaging resolution of the fault-karst structure and save computing cost without losing accuracy. In addition, a test on field data processing demonstrates the advantages of our algorithm.
Adapted Physical Educators’ Social Media Usage for Professional Learning
Authors: McNamara Scott , Ng Kwok , Healy Sean
Published: March 2022

Physical educators report a multitude of benefits from accessing informal learning opportunities via social media. However, a lack of research has been conducted on adapted physical education (APE) teachers’ usage of social media for professional learning (PL) purposes. Thus, the purpose of this study was to explore how APE teachers use social media to learn about APE content. A survey was used to identify APE teachers’ (n = 73) social media usage patterns. Descriptive statistics were reported, and multiple t-tests were used to compare how participants perceived the usefulness of social media vs. conferences for PL purposes. Multiple linear regression analyses were also used to identify variables that predicted the participants’ likelihood of attending conferences and using social media for PL purposes. Results demonstrated many participants used an array of social media platforms to learn about topics such as activities and equipment. However, participants indicated that conferences were significantly more useful in gaining information about APE related topics compared to social media. Following multivariate analysis, personal and professional usage of social media for PL purposes was associated with conference attendance. The potential of APE teachers and organizing bodies to use social media for PL purposes and future research recommendations are discussed.
27-Hydroxycholesterol, The Estrogen Receptor Modulator, Alters DNA Methylation in Breast Cancer
Authors: Vini Ravindran , Rajavelu Arumugam , Sreeharshan Sreeja
Published: March 2022

27-hydroxycholesterol (27-HC) is the first known endogenous selective estrogen receptor modulator (SERM), and its elevation from normal levels is closely associated with breast cancer. A plethora of evidence suggests that aberrant epigenetic signatures in breast cancer cells can result in differential responses to various chemotherapeutics and often leads to the development of resistant cancer cells. Such aberrant epigenetic changes are mostly dictated by the microenvironment. The local concentration of oxygen and metabolites in the microenvironment of breast cancer are known to influence the development of breast cancer. Hence, we hypothesized that 27-HC, an oxysterol, which has been shown to induce breast cancer progressionviaestrogen receptor alpha (ERα) and liver X receptor (LXR) and by modulating immune cells, may also induce epigenetic changes. For deciphering the same, we treated the estrogen receptor-positive cells with 27-HC and identified DNA hypermethylation on a subset of genes by performing DNA bisulfite sequencing. The genes that showed significant DNA hypermethylation werephosphatidylserine synthase 2 (PTDSS2), MIR613, indoleamine 2,3-dioxygenase 1 (IDO1), thyroid hormone receptor alpha (THRA), dystrotelin (DTYN),andmesoderm induction early response 1, family member 3 (MIER). Furthermore, we found that 27-HC weakens the DNMT3B association with the ERα in MCF-7 cells. This study reports that 27-HC induces aberrant DNA methylation changes on the promoters of a subset of genes through modulation of ERα and DNMT3B complexes to induce the local DNA methylation changes, which may dictate drug responses and breast cancer development.
Cumulative Impact of Federal and State Policy on Minimum Selling Price of Sustainable Aviation Fuel
Authors: Brandt Kristin L. , Martinez-Valencia Lina , Wolcott Michael P.
Published: March 2022

With jet fuel consumption projected to more than double by 2050, dramatic expansion of sustainable aviation fuel (SAF) use will be essential to meeting the aviation industry goal of achieving carbon neutrality in the same time frame. However, to date, the SAF price has, in part, been responsible for the lack of widespread adoption signaling the need for strong and stable policy. Multiple pathways have been developed and received ASTM approval to convert a variety of feedstocks into SAF, each with strengths and weaknesses that vary with conversion technology, feedstock, and production location. To assist researchers and governments in understanding the role of policy on fuel pricing, a set of harmonized, techno-economic analyses (TEAs) were developed to assess three ASTM-qualified production pathways: hydroprocessed esters and fatty acids (HEFAs), alcohol to jet (ATJ), and Fischer–Tropsch (FT), with multiple feedstock options. These decision support tools were used to assess the minimum selling price (MSP) for fuel distillates. Both mature (nth) plants and first of a kind (pioneer plants) were assessed using TEAs. Existing and proposed U.S. incentives, at both the federal and state levels, were integrated into the tools to determine the impact on the MSP. Considering the existing federal policies, analysis indicated that HEFAs could achieve a SAF price that would be competitive to conventional fuels when using waste lipid feedstocks, making this the most viable near-term option. However, this feedstock for HEFAs is limited and unlikely to support the production of large quantities of SAF. After stacking federal and state programs, SAF produced using FT with municipal solid waste (MSW) has the lowest MSP, although FT forest residuals, FT agricultural residues, ATJ corn ethanol, and HEFAs using second crop oilseeds all approach the historical range of traditional jet fuel prices for nth plants. Pioneer plants are viable for only ATJ corn ethanol; however, FT-MSW is approaching price parity.
Optimal Virtual Inertial-Based Power System Frequency Regulation Through Multi-Cluster Wind Turbines Using BWOA
Authors: Liu Chao , Li Qingquan , Tian Xinshou , Li Changgang
Published: March 2022

Large-scale wind power connected to the grid efficiently reduces fossil fuel consumption, but extremely decreases grid inertial and increases frequency regulation pressure on the grid. Therefore, various wind farm-based frequency regulation technologies have been investigated in recent decades. Adaptive inertial droop control of wind turbines was considered as one of the most effective methods to enhance the inertia of the grid, because it can solve the decoupling problem between the power of wind farms and power system frequency. However, the present approaches mainly pay attention to the first frequency drop (FFD) or ignore the influence of control parameters. Hence, this paper proposes a black widow optimization algorithm (BWOA)-based step start-up adaptive inertial droop controller to smooth frequency fluctuation as well as alleviate FFD, the secondary frequency drop (SFD), and the third frequency drop (TFD). Besides, BWOA is employed to extract the best parameters of the designed controller under a 150-MW load increase. Then, the extracted parameters are used in three other load variation events to evaluate the performance of the proposed method in MATLAB/Simulink. Simulation results indicate that BWOA acquires satisfactory performances on various designed load variations. Compared with the trial-and-error method, FFD and TFD with BWOA under load increase are decreased by 10.9% and 12.8% at most, respectively.
Low-Carbon Strategic Planning of Integrated Energy Systems
Authors: Guo Yongtao , Xiang Yue
Published: March 2022

With the rapid promotion of renewable energy technologies and the trend to a low-carbon society, the positive impacts of an integrated energy system that realizes various forms of energy-utilizing improvement and carbon reduction have fully emerged. Hydrogen with a decarbonized characteristic being integrated into the integrated energy system has become a viable option to offset the intermittency of renewables and decline the fossil fuel usage. An optimal planning model of a wind–photovoltaic–hydrogen storage-integrated energy system with the objective of total economic and environmental cost minimization by considering various energy technology investments is proposed. Case studies are developed to compare the economic and environmental benefits of different energy investment scenarios, especially hydrogen applications. The cost–benefit analysis was carried out to prove that hydrogen investment is not a cost-competitive option but can alleviate the burden of carbon emissions somehow. Finally, sensitivity analysis of key parameters of sale capacity, carbon tax, and renewable penetration level was performed to indicate the rational investment for a wind–photovoltaic–hydrogen storage-integrated energy system.
The Occurrence and Distribution Pattern of Antibiotic Resistance Genes and Bacterial Community in the Ili River
Authors: Yang Xiaobo , Yan Li , Yang Yutong , Zhou Hongrui , Cao Yang , Wang Shang , Xue Bin , Li Chenyu , Zhao Chen , Zhang Xi , Shen Zhiqiang , Wang Jingfeng , Qiu Zhigang
Published: March 2022

The emergence of antibiotic resistance genes (ARGs) is a great risk to the ecosystem and human health; however, there are rare systematic studies about the characterization and source identification of ARGs in continental rivers. This study examined the occurrence of bacterial communities and ARGs in the water and soil of the Ili River using bacterial testing and metagenomic sequencing. Total dissolved solids (TDSs) and total bacterial count significantly increased from upstream to downstream sites. Enterococcus showed the highest abundance in Cockdara. Metagenomic sequencing revealed that the bacterial communities of surface water were different from those of nearshore soils. Among the top 10 ARGs, fluoroquinolone and aminoglycoside resistance genes exhibited dominant relative abundance, but only the multidrug resistance gene adeF was common in all water and soil samples. Proteobacteria carried almost 61% of ARGs, suggesting that these could be the main antibiotic-resistant bacteria (ARB) in the Ili River. Proteobacteria and ARB were mainly distributed in Yining city and Cockdara. Furthermore, the distribution pattern among the five sampling sites indicated that human activity and animal husbandry greatly contributed to the ARB and ARG contamination. This study first investigated the occurrence and distribution pattern of ARGs in the Ili River, demonstrating a clear correlation between bacteria and ARGs, and ARGs and mobile genetic elements (MGEs).
Redox Zone and Trophic State as Drivers of Methane-Oxidizing Bacterial Abundance and Community Structure in Lake Sediments
Authors: van Grinsven Sigrid , Meier Dimitri V. , Michel Anja , Han Xingguo , Schubert Carsten J. , Lever Mark A.
Published: March 2022

Eutrophication is expected to increase methane production in freshwater sediments worldwide over the coming decades. Methane-oxidizing bacteria (MOB) consume a significant fraction of this sedimentary methane, but the factors that control their distributions and activities are not understood. By combining genetic approaches (pmoA, 16S rRNA gene, metagenomics) with geochemical and sedimentological analyses, we investigate the role of trophic state, electron acceptors, oxygen (O2) and methane fluxes, and potential methylotrophic partner organisms in driving the distributions, abundances, and community compositions of MOB across five lakes in central Switzerland. Although methane fluxes were highest in the eutrophic lakes, methanotrophic abundances peaked in oxic and anoxic sediments of an oligotrophic lake. In all lakes, Type I gammaproteobacterial Methylococcaceae dominated oxic and suboxic bottom water and surface sediments, showing strong correlations with abundances of putatively methylotrophic Methylophilaceae, whereas Type II alphaproteobacterial Methylocystaceae increased in deeper, anoxic sediment layers. Methanotrophic bacteria belonging to the NC10 phylum were predominantly detected within denitrifying sediment of the oligotrophic lake, matching their presumed nitrite-dependent lifestyle. While dominant MOB taxa at the genus-level follow vertical distributions of different aerobic and anaerobic respiration reactions, trophic state at the time of sediment deposition was the best predictor of MOB community structure at the operational taxonomic unit (OTU) level. Elevated methane fluxes combined with low MOB abundances in surface sediments of eutrophic lakes, moreover, support the notion that in eutrophic lakes a major portion of sedimentary methane bypasses the biological methane filter and escapes to overlying water.
Sex-Biased Population Admixture Mediated Subsistence Strategy Transition of Heishuiguo People in Han Dynasty Hexi Corridor
Authors: Xiong Jianxue , Du Panxin , Chen Guoke , Tao Yichen , Zhou Boyan , Yang Yishi , Wang Hui , Yu Yao , Chang Xin , Allen Edward , Sun Chang , Zhou Juanjuan , Zou Yetao , Xu Yiran , Meng Hailiang , Tan Jingze , Li Hui , Wen Shaoqing
Published: March 2022

The Hexi Corridor was an important arena for culture exchange and human migration between ancient China and Central and Western Asia. During the Han Dynasty (202 BCE–220 CE), subsistence strategy along the corridor shifted from pastoralism to a mixed pastoralist-agriculturalist economy. Yet the drivers of this transition remain poorly understood. In this study, we analyze the Y-chromosome and mtDNA of 31 Han Dynasty individuals from the Heishuiguo site, located in the center of the Hexi Corridor. A high-resolution analysis of 485 Y-SNPs and mitogenomes was performed, with the Heishuiguo population classified into Early Han and Late Han groups. It is revealed that (1) when dissecting genetic lineages, the Yellow River Basin origin haplogroups (i.e., Oα-M117, Oβ-F46, Oγ-IMS-JST002611, and O2-P164+, M134-) reached relatively high frequencies for the paternal gene pools, while haplogroups of north East Asian origin (e.g., D4 and D5) dominated on the maternal side; (2) in interpopulation comparison using PCA and Fst heatmap, the Heishuiguo population shifted from Southern-Northern Han cline to Northern-Northwestern Han/Hui cline with time, indicating genetic admixture between Yellow River immigrants and natives. By comparison, in maternal mtDNA views, the Heishuiguo population was closely clustered with certain Mongolic-speaking and Northwestern Han populations and exhibited genetic continuity through the Han Dynasty, which suggests that Heishuiguo females originated from local or neighboring regions. Therefore, a sex-biased admixture pattern is observed in the Heishuiguo population. Additionally, genetic contour maps also reveal the same male-dominated migration from the East to Hexi Corridor during the Han Dynasty. This is also consistent with historical records, especially excavated bamboo slips. Combining historical records, archeological findings, stable isotope analysis, and paleoenvironmental studies, our uniparental genetic investigation on the Heishuiguo population reveals how male-dominated migration accompanied with lifestyle adjustments brought by these eastern groups may be the main factor affecting the subsistence strategy transition along the Han Dynasty Hexi Corridor.
Proteome-Wide Identification and Functional Analysis of Lysine Crotonylation in Trichophyton rubrum Conidial and Mycelial Stages
Authors: Xu Xingye , Hu Xiangqi , Dong Jie , Xue Ying , Liu Tao , Jin Qi
Published: March 2022

Lysine crotonylation is a newly discovered post-translational modification (PTM) with key roles in various important regulatory pathways. Despite its functional significance, there is limited knowledge about crotonylation in fungi. Trichophyton rubrum is the most common fungal pathogen in human infection and is considered a model organism of dermatophytes and human pathogenic filamentous fungi. In this study, we obtained a proteome-wide crotonylation profile of T. rubrum, leading to the identification of 14,019 crotonylated sites on 3144 proteins. The crotonylated proteins were significantly involved in translation and in various metabolic and biosynthetic processes. Some proteins related to fungal pathogenicity were also found to be targets of crotonylation. In addition, extensive crotonylation was found on histones, suggesting a role in epigenetic regulation. Furthermore, about half of the crotonylated proteins were specific to either the conidial or the mycelial stage, and functional enrichment analysis showed some differences between the two stages. The results suggest that the difference in crotonylation between the two stages is not due to differences in protein abundance. Crosstalk of crotonylation with acetylation, propionylation, and succinylation suggests distinct regulatory roles. This study is the first crotonylation analysis in dermatophytes and human pathogenic filamentous fungi. These results represent a solid foundation for further research on PTM regulatory mechanisms in fungi and should facilitate improved antifungal strategies against these medical important species.
IgG4-Related Disease With Gastrointestinal Involvement: Case Reports and Literature Review
Authors: Zhang Xinhe , Jin Xing , Guan Lin , Lin Xuyong , Li Xuedan , Li Yiling
Published: March 2022

IgG4-related disease is an immune-mediated chronic, systemic, and autoinflammatory disease that can affect various organs throughout the body. The most commonly affected areas are the pancreas and biliary system. Due to the diverse clinical manifestations of the disease, it affects widely distributed organs. Thus, it is often easy to misdiagnose or miss. The digestive tract is a rarely affected system, and most IgG4-related gastric diseases manifest as tumors detected by endoscopy. This article reports two special cases with IgG4-related disease involving atrophic gastritis and intestinal polyps to provide a more empirical and theoretical basis for clinical diagnosis and treatment.
Robust In Vitro Pharmacology of Tmod, a Synthetic Dual-Signal Integrator for Cancer Cell Therapy
Authors: Manry Diane , Bolanos Kristian , DiAndreth Breanna , Mock Jee-Young , Kamb Alexander
Published: March 2022

Progress toward improved solid-tumor treatment has long been hindered by the lack of truly tumor-specific targets. We have developed an approach to T cell therapy based on a dual-receptor system called Tmod™ that addresses this problem. The Tmod system exploits one of the few common genetic differences between tumor and normal cells: loss of heterozygosity (LOH). It utilizes the basic mechanistic logic that evolved in early vertebrates to mediate self vs. non-self discrimination, where an activation stimulus is blocked by self-ligands. Tmod constructs employ a chimeric antigen receptor (CAR) or T cell receptor (TCR) as activator component and a modified LIR-1 inhibitory receptor (blocker) to achieve high selectivity based on expression of the blocker antigen (Ag). Here we explore thein vitropharmacology of a blocker directed at the HLA-A*02 Ag paired with either a mesothelin CAR or an HLA-A*11-restricted KRAS peptide TCR. While more sensitive to receptor expression changes on effector cells, we show that Tmod response is well-buffered against variations in Ag levels on target cells. In addition, the data reveal at least two distinguishable pharmacologic mechanisms of Tmod blocker function: (1) reducing activator sensitivity and (2) decreasing activation magnitude.
Constraining the Contribution of Hydrothermal Iron to Southern Ocean Export Production Using Deep Ocean Iron Observations
Authors: Tagliabue Alessandro , Bowie Andrew R. , Holmes Thomas , Latour Pauline , van der Merwe Pier , Gault-Ringold Melanie , Wuttig Kathrin , Resing Joseph A.
Published: March 2022

Hydrothermal iron supply contributes to the Southern Ocean carbon cycle via the regulation of regional export production. However, as hydrothermal iron input estimates are coupled to helium, which are uncertain depending on whether helium inputs are based on ridge spreading rates or inverse modelling, questions remain regarding the magnitude of the export production impacts. A particular challenge is the limited observations of dissolved iron (dFe) supply from the abyssal Southern Ocean ridge system to directly assess different hydrothermal iron supply scenarios. We combine ocean biogeochemical modelling with new observations of dFe from the abyssal Southern Ocean to assess the impact of hydrothermal iron supply estimated from either ridge spreading rate or inverse helium modelling on Southern Ocean export production. The hydrothermal contribution to dFe in the upper 250 m reduces 4–5 fold when supply is based on inverse modelling, relative to those based on spreading rate, translating into a 36–73% reduction in the impact of hydrothermal iron on export production. However, only the spreading rate input scheme reproduces observed dFe anomalies >1 nM around the circum-Antarctic ridge. The model correlation with observations drops 3 fold under the inverse modelling input scheme. The best dFe scenario has a residence time for hydrothermal iron that is between 21 and 34 years, highlighting the importance of rapid physical mixing to surface waters. Overall, because of its short residence time, hydrothermal Fe supplied locally by circum-Antarctic ridges is most important to the Southern Ocean carbon cycle and our results highlight decoupling between hydrothermal iron and helium supply.
Soundscape Maps of Soniferous Fishes Observed From a Mobile Glider
Authors: Luczkovich Joseph J. , Sprague Mark W.
Published: March 2022

Most passive acoustic studies of the soundscape rely on fixed recorders, which provide good temporal resolution of variation in the soundscape, but poor spatial coverage. In contrast, a mobile recording device can show variation in the soundscape over large spatial areas. We used a Liquid Robotics SV2 wave glider fitted with a tow body with a passive acoustic recorder and hydrophone, to survey and record the soundscape of the Atlantic Ocean off North Carolina (United States). Recordings were analyzed using power spectral band (PSB) sums in frequencies associated with soniferous fish species in the families Sciaenidae (drums and croakers), Ophidiidae (cusk-eels), Batrachoididae (toadfish), Triglidae (sea robins), and Serranidae (groupers). PSB sums were plotted as the wave glider moved offshore and along the coast, came back inshore, and circled artificial and natural reefs. The soundscape in water <20 m was dominated by nocturnal fish choruses with PSB sums > 120 dB re 1 μPa2: a Sciaenidae mixed-species chorus, an unknown “grunt” chorus, an unknown “buzz” chorus, and an Ophidiidae chorus. The Ophidiidae and unknown “buzz” fish choruses dominated in the range of 1600–3200 Hz and were similar in sound pressure level (SPL) to the US Navy recordings made at Cape Lookout (136 dB in 2017 vs. 131 dB in 1943). In deeper water (27–30 m), we recorded Triglidae “honks,” oyster toadfish “boat whistles,” Sciaenidae “booms” and “clucks,” and grouper “growls.” We recorded a nocturnal 5600–Hz signal while the glider was passing near known live bottom reefs and artificial reefs. Vessel noise (100–200 Hz) was part of the soundscape in shipping lanes as large cargo vessels passed by the glider. Rainfall and thunder were also part of the soundscape. The maximum SPL observed (148 dB re 1 μPa) occurred during a mixed-species Sciaenidae fish chorus near Cape Lookout that was dominated by unknown “grunt” calls. Passive acoustic monitoring from mobile platforms can be used to discover and map the locations of fish choruses, identify areas of their habitat use, and locate previously unknown locations of reefs and fish spawning areas during ocean surveys.
The Extent and Pattern of Mariculture Impacts on Spatial and Seasonal Variations of Sediment Bacterial Communities Among Three Coastal Waters
Authors: Shi Rongjun , Han Tingting , Huang Honghui , Kuang Zexing , Qi Zhanhui
Published: March 2022

Benthic sediment bacteria are important drivers for material circulation and energy flow in aquatic ecosystem, and they are sensitive to environmental changes. Large scale suspended mariculture in coastal waters induces high organic loading to the sediment through biodeposition, and causes changes in sediment biogeochemical features. However, the impacts of mariculture on sediment bacterial communities are not fully understood. In the present study, sediment samples were collected from three coastal semi-enclosed bays of China, i.e., Sanggou Bay, Daya Bay, and Maniao Bay, where large scale mariculture were carried out since the 1980s. High-throughput sequencing was used to examine the spatial and seasonal variations of bacterial communities. The results indicated that the dominant phyla of three bays were Proteobacteria (39.18–47.21%), Bacteroidetes (9.91–19.25%), and Planctomycetes (7.12–13.88%). Spatial variations played a greater role in shaping the bacterial communities than seasonal variation. The bacterial diversity indices (Chao1, Pielou’s evenness, and Shannon-Wiener index) of Sanggou Bay were significantly lower than those of Daya Bay and Maniao Bay. For seasonal variation, bacterial diversity indices in spring were significantly lower than that in autumn. Five keystone taxa belonging to Planctomycetes, Alphaproteobacteria, and Acidobacteria were identified in Sanggou Bay. Temperature, particulate organic carbon, pH, and salinity were the most important environmental factors shaping the spatial and seasonal variations of bacterial communities in the studied areas. The abundances of bacteria, particularly Bacteroidetes, Gammaproteobacteria, and Deltaproteobacteria, were significantly correlated with the mariculture-driven chemical properties of the sediment. These results indicated that intensive mariculture could induce profound and diverse impacts on the bacterial communities, and therefore modify their role in marine ecosystem. The interactions between mariculture and sediment bacterial communities should be considered in regard to mariculture management and carrying capacity.
Habitat Selection and Specialisation of Herring Gulls During the Non-breeding Season
Authors: O’Hanlon Nina J. , Thaxter Chris B. , Burton Niall H. K. , Grant Dave , Clark Nigel A. , Clewley Gary D. , Conway Greg J. , Barber Lee J. , McGill Rona A. R. , Nager Ruedi G.
Published: March 2022

Understanding both the distribution and habitat use of populations through the annual cycle is vital to understanding how vulnerable species are to environmental change. However, distributions and habitat use can vary among individuals and populations, particularly in generalist species, with variation depending on external environmental factors, such as resource availability. Comprehensive information across multiple populations is important to guide spatial planning of protected areas and is increasingly available for breeding individuals, but it is still lacking for many species, particularly seabirds, during the non-breeding season, especially those with declining populations. We investigated within-species variation in migratory strategies, non-breeding habitat selection and habitat and spatial specialisation in a declining, opportunistic, generalist seabird, the European herring gullLarus argentatus, from multiple breeding colonies across northwest England and southwest Scotland using global positioning system (GPS) tracking during the non-breeding season of 2014/15. Although several individuals stayed within the area of the breeding colony, the majority of individuals migrated in a southerly direction and spent half of the annual cycle (on average 53%) away from the breeding area and kept moving through the non-breeding period. During non-breeding, herring gulls selected mainly marine intertidal, but also a range of anthropogenic terrestrial habitats. However, habitat selection differed between geographical regions, within a geographical region and among individuals. There was a generalist use of non-breeding habitats at the population level, but some habitat specialisation at the individual level that was repeatable through the non-breeding period despite individuals showing low spatial specialisation. The results highlight the importance of intertidal habitat and a mix of alternative foraging habitats in the wintering areas of herring gulls. The results also highlight that habitat selection in an opportunistic generalist can vary even between nearby regions and that appropriate conservation management plans may need to be tailored to regional differences in specific non-breeding areas.
Lipid Biomarker Patterns Reflect Nutritional Strategies of Seep-Dwelling Bivalves From the South China Sea
Authors: Guan Hongxiang , Feng Dong , Birgel Daniel , Kiel Steffen , Peckmann Jörn , Li Sanzhong , Tao Jun
Published: March 2022

Invertebrates living at methane seeps such as mussels and clams gain nutrition through symbiosis with chemosynthetic, chiefly methanotrophic and thiotrophic bacteria. Lipid biomarkers, including their compound-specific carbon stable isotope compositions, extracted from the host tissues are predestined for deciphering the various sources of diets and the associations among varying environments, endosymbionts, and hosts. Here, we investigated lipid inventories of soft tissues of two bathymodiolin mussel species hosting aerobic methanotrophic bacteria (Gigantidas platifrons from Site F and Gigantidas haimaensis from Haima seeps), one bathymodiolin mussel with thiotrophic bacteria (Bathymodiolus aduloides from Haima seeps), and one vesicomyid clam (Archivesica marissinica from Haima seeps) from the South China Sea. The gills of mussels hosting methanotrophic symbionts were found to contain high amounts of lipids of aerobic methanotrophic bacteria, such as the 4,4-dimethyl lanosterol, and other 4-methyl sterols, and the type I methanotroph-specific monounsaturated fatty acids (MUFAs) C16:1ω9 and C16:1ω8. Production of methyl-sterols is favored over fatty acids at low oxygen concentrations, as demonstrated in culture experiments with Methylococcus capsulatus. Since lesser fatty acids and abundant sterols are found in G. haimaensis compared to G. platifrons, G. haimaensis apparently lived at very low oxygen levels. Extremely high levels of MUFAs C16:1ω7 and C18:1ω7 were found in gill tissue of both B. aduloides and the vesicomyid clam A. marissinica. Given the absence of ω8 fatty acids, both B. aduloides and the vesicomyid clam contain thiotrophic bacteria only. The occurrence of 13C-enriched 24-methylenecholesterol in B. aduloides indicates that the animal complemented its diet by filter-feeding (ca. 3% of the total sterol inventory) on photosynthetically derived carbon, whereas the majority of sterols are pointing to a diet relying on endosymbionts. Different types of 4-methyl sterols were observed between the thiotroph-containing mussel and methanotroph-containing mussels, suggesting different biosynthetic steps are present from lanosterol to cholesterol between animal hosts and aerobic methanotrophs. Among the four bivalve species, specific lipid biomarker patterns diagnostic for either the symbionts or the hosts yielded similar δ13C values in each species, indicating that the host obtained its nutrition either directly from the symbionts or derived at least most of its carbon in this way. The information derived from lipid biomarkers of bivalves and their corresponding symbionts in modern environments is vital to interpret data from the rock record, where most other methods to study microbial community composition are not applicable.
Species Delimitation of Hexacorallia and Octocorallia Around Iceland Using Nuclear and Mitochondrial DNA and Proteome Fingerprinting
Authors: Korfhage Severin A. , Rossel Sven , Brix Saskia , McFadden Catherine S. , Ólafsdóttir Steinunn Hilma , Martínez Arbizu Pedro
Published: March 2022

Cold-water corals build up reef structures or coral gardens and play an important role for many organisms in the deep sea. Climate change, deep-sea mining, and bottom trawling are severely compromising these ecosystems, making it all the more important to document the diversity, distribution, and impacts on corals. This goes hand in hand with species identification, which is morphologically and genetically challenging for Hexa- and Octocorallia. Morphological variation and slowly evolving molecular markers both contribute to the difficulty of species identification. In this study, a fast and cheap species delimitation tool for Octocorallia and Scleractinia, an order of the Hexacorallia, of the Northeast Atlantic was tested based on 49 specimens. Two nuclear markers (ITS2 and 28S rDNA) and two mitochondrial markers (COI and mtMutS) were sequenced. The sequences formed the basis of a reference library for comparison to the results of species delimitation based on proteomic fingerprinting using MALDI-TOF MS. The genetic methods were able to distinguish 17 of 18 presumed species. Due to a lack of replicates, using proteome fingerprinting only 7 species were distinguishable. Species that could not be distinguished from one another still achieved good signals of spectra but were not represented by enough specimens for comparison. Therefore, it is predicted that with an extensive reference library of proteome spectra for Scleractinia and Octocorallia, MALDI-TOF MS may provide a rapid and cost-effective alternative for species discrimination in corals.
Fast, Detailed, Accurate Simulation of a Thermal Car-Cabin Using Machine-Learning
Authors: Jess Brandi , Brusey James , Rostagno Matteo Maria , Merlo Alberto Maria , Gaura Elena , Gyamfi Kojo Sarfo
Published: March 2022

Car-cabin thermal systems, including heated seats, air-conditioning, and radiant panels, use a large proportion of the energy budget of electric vehicles and thus reduce their effective range. Optimising these systems and their controllers might be possible with computationally efficient simulation. Unfortunately, state-of-the-art simulators are either too slow or provide little resolution of the cabin’s thermal environment. In this work, we propose a novel approach to developing a fast simulation by machine learning (ML) from measurements within the car cabin over a number of trials within a climatic wind tunnel. A range of ML approaches are tried and compared. The best-performing ML approach is compared to more traditional 1D simulation in terms of accuracy and speed. The resulting simulation, based on Multivariate Linear Regression, is fast (5 microseconds per simulation second), and yields good accuracy (NRMSE 1.8%), which exceeds the performance of the traditional 1D simulator. Furthermore, the simulation is able to differentially simulate the thermal environment of the footwell versus the head and the driver position versus the front passenger seat, but unlike a traditional 1D model cannot support changes to the physical structure. This fast method for obtaining computationally efficient simulators of car cabins will accelerate adoption of techniques such as Deep Reinforcement Learning for climate control.
COVID-Net CT-2: Enhanced Deep Neural Networks for Detection of COVID-19 From Chest CT Images Through Bigger, More Diverse Learning
Authors: Gunraj Hayden , Sabri Ali , Koff David , Wong Alexander
Published: March 2022

The COVID-19 pandemic continues to rage on, with multiple waves causing substantial harm to health and economies around the world. Motivated by the use of computed tomography (CT) imaging at clinical institutes around the world as an effective complementary screening method to RT-PCR testing, we introduced COVID-Net CT, a deep neural network tailored for detection of COVID-19 cases from chest CT images, along with a large curated benchmark dataset comprising 1,489 patient cases as part of the open-source COVID-Net initiative. However, one potential limiting factor is restricted data quantity and diversity given the single nation patient cohort used in the study. To address this limitation, in this study we introduce enhanced deep neural networks for COVID-19 detection from chest CT images which are trained using a large, diverse, multinational patient cohort. We accomplish this through the introduction of two new CT benchmark datasets, the largest of which comprises a multinational cohort of 4,501 patients from at least 16 countries. To the best of our knowledge, this represents the largest, most diverse multinational cohort for COVID-19 CT images in open-access form. Additionally, we introduce a novel lightweight neural network architecture called COVID-Net CT S, which is significantly smaller and faster than the previously introduced COVID-Net CT architecture. We leverage explainability to investigate the decision-making behavior of the trained models and ensure that decisions are based on relevant indicators, with the results for select cases reviewed and reported on by two board-certified radiologists with over 10 and 30 years of experience, respectively. The best-performing deep neural network in this study achieved accuracy, COVID-19 sensitivity, positive predictive value, specificity, and negative predictive value of 99.0%/99.1%/98.0%/99.4%/99.7%, respectively. Moreover, explainability-driven performance validation shows consistency with radiologist interpretation by leveraging correct, clinically relevant critical factors. The results are promising and suggest the strong potential of deep neural networks as an effective tool for computer-aided COVID-19 assessment. While not a production-ready solution, we hope the open-source, open-access release of COVID-Net CT-2 and the associated benchmark datasets will continue to enable researchers, clinicians, and citizen data scientists alike to build upon them.
Three-Dimensional Radiomics Features of Magnetic Resonance T2-Weighted Imaging Combined With Clinical Characteristics to Predict the Recurrence of Acute Pancreatitis
Authors: Hu Yuntao , Liu Nian , Tang Lingling , Liu Qianqian , Pan Ke , Lei Lixing , Huang Xiaohua
Published: March 2022

Objective

To explore the diagnostic value of radiomics model based on magnetic resonance T2-weighted imaging for predicting the recurrence of acute pancreatitis.

Methods

We retrospectively collected 190 patients with acute pancreatitis (AP), including 122 patients with initial acute pancreatitis (IAP) and 68 patients with recurrent acute pancreatitis (RAP). At the same time, the clinical characteristics of the two groups were collected. They were randomly divided into training group and validation group in the ratio of 7:3. One hundred thirty-four cases in the training group, including 86 cases of IAP and 48 cases of RAP. There were 56 cases in the validation group, including 36 cases of IAP and 20 cases of RAP. Least absolute shrinkage and selection operator (LASSO) were used for feature screening. Logistic regression was used to establish the radiomics model, clinical model and combined model for predicting AP recurrence. The predictive ability of the three models was evaluated by the area under the curve (AUC). The recurrence risk in patients with AP was assessed using the nomogram.

Results

The AUCs of radiomics model in training group and validation group were 0.804 and 0.788, respectively. The AUCs of the combined model in the training group and the validation group were 0.833 and 0.799, respectively. The AUCs of the clinical model in training group and validation group were 0.677 and 0.572, respectively. The sensitivities of the radiomics model, combined model, and clinical model were 0.646, 0.691, and 0.765, respectively. The specificities of the radiomics model, combined model, and clinical model were 0.791, 0.828, and 0.590, respectively. There was no significant difference in AUC between the radiomics model and the combined model for predicting RAP (p = 0.067). The AUCs of the radiomics model and combined model were greater than those of the clinical model (p = 0.008 and p = 0.007, respectively).

Conclusions

Radiomics features based on magnetic resonance T2WI could be used as biomarkers to predict the recurrence of AP, and radiomics model and combined model can provide new directions for predicting recurrence of acute pancreatitis.