bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge Graph Dataset for Semantic Enrichment of Picture Description in NAPS Database
Authors: Horvat Marko , Gledec Gordan , Jagušt Tomislav , Kalafatić Zoran
Published: August 2023

This data description introduces a comprehensive knowledge graph (KG) dataset with detailed information about the relevant high-level semantics of visual stimuli used to induce emotional states stored in the Nencki Affective Picture System (NAPS) repository. The dataset contains 6808 systematically manually assigned annotations for 1356 NAPS pictures in 5 categories, linked to WordNet synsets and Suggested Upper Merged Ontology (SUMO) concepts presented in a tabular format. Both knowledge databases provide an extensive and supervised taxonomy glossary suitable for describing picture semantics. The annotation glossary consists of 935 WordNet and 513 SUMO entities. A description of the dataset and the specific processes used to collect, process, review, and publish the dataset as open data are also provided. This dataset is unique in that it captures complex objects, scenes, actions, and the overall context of emotional stimuli with knowledge taxonomies at a high level of quality. It provides a valuable resource for a variety of projects investigating emotion, attention, and related phenomena. In addition, researchers can use this dataset to explore the relationship between emotions and high-level semantics or to develop data-retrieval tools to generate personalized stimuli sequences. The dataset is freely available in common formats (Excel and CSV).
Machine Learning Models for Prediction of Severe Pneumocystis carinii Pneumonia after Kidney Transplantation: A Single-Center Retrospective Study
Authors: Liu Yiting , Qiu Tao , Hu Haochong , Kong Chenyang , Zhang Yalong , Wang Tianyu , Zhou Jiangqiao , Zou Jilin
Published: August 2023

Background: The objective of this study was to formulate and validate a prognostic model for postoperative severe Pneumocystis carinii pneumonia (SPCP) in kidney transplant recipients utilizing machine learning algorithms, and to compare the performance of various models. Methods: Clinical manifestations and laboratory test results upon admission were gathered as variables for 88 patients who experienced PCP following kidney transplantation. The most discriminative variables were identified, and subsequently, Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), K-Nearest Neighbor (KNN), Light Gradient Boosting Machine (LGBM), and eXtreme Gradient Boosting (XGB) models were constructed. Finally, the models’ predictive capabilities were assessed through ROC curves, sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and F1-scores. The Shapley additive explanations (SHAP) algorithm was employed to elucidate the contributions of the most effective model’s variables. Results: Through lasso regression, five features—hemoglobin (Hb), Procalcitonin (PCT), C-reactive protein (CRP), progressive dyspnea, and Albumin (ALB)—were identified, and six machine learning models were developed using these variables after evaluating their correlation and multicollinearity. In the validation cohort, the RF model demonstrated the highest AUC (0.920 (0.810–1.000), F1-Score (0.8), accuracy (0.885), sensitivity (0.818), PPV (0.667), and NPV (0.913) among the six models, while the XGB and KNN models exhibited the highest specificity (0.909) among the six models. Notably, CRP exerted a significant influence on the models, as revealed by SHAP and feature importance rankings. Conclusions: Machine learning algorithms offer a viable approach for constructing prognostic models to predict the development of severe disease following PCP in kidney transplant recipients, with potential practical applications.
A Machine Learning Approach to Assess Patients with Deep Neck Infection Progression to Descending Mediastinitis: Preliminary Results
Authors: Chen Shih-Lung , Chin Shy-Chyi , Chan Kai-Chieh , Ho Chia-Ying
Published: August 2023

Background: Deep neck infection (DNI) is a serious infectious disease, and descending mediastinitis is a fatal infection of the mediastinum. However, no study has applied artificial intelligence to assess progression to descending mediastinitis in DNI patients. Thus, we developed a model to assess the possible progression of DNI to descending mediastinitis. Methods: Between August 2017 and December 2022, 380 patients with DNI were enrolled; 75% of patients (n = 285) were assigned to the training group for validation, whereas the remaining 25% (n = 95) were assigned to the test group to determine the accuracy. The patients’ clinical and computed tomography (CT) parameters were analyzed via the k-nearest neighbor method. The predicted and actual progression of DNI patients to descending mediastinitis were compared. Results: In the training and test groups, there was no statistical significance (all p > 0.05) noted at clinical variables (age, gender, chief complaint period, white blood cells, C-reactive protein, diabetes mellitus, and blood sugar), deep neck space (parapharyngeal, submandibular, retropharyngeal, and multiple spaces involved, ≥3), tracheostomy performance, imaging parameters (maximum diameter of abscess and nearest distance from abscess to level of sternum notch), or progression to mediastinitis. The model had a predictive accuracy of 82.11% (78/95 patients), with sensitivity and specificity of 41.67% and 87.95%, respectively. Conclusions: Our model can assess the progression of DNI to descending mediastinitis depending on clinical and imaging parameters. It can be used to identify DNI patients who will benefit from prompt treatment.
Evaluation of Spleen Stiffness in Young Healthy Volunteers Using Magnetic Resonance Elastography
Authors: Obrzut Marzanna , Atamaniuk Vitaliy , Ehman Richard L. , Yin Meng , Cholewa Marian , Gutkowski Krzysztof , Domka Wojciech , Ozga Dorota , Obrzut Bogdan
Published: August 2023

Purpose: Magnetic resonance elastography (MRE) has been established as the most accurate noninvasive technique for diagnosing liver fibrosis. Recent publications have suggested that the measurement of splenic stiffness is useful in setting where portal hypertension may be present. The goal of the current study was to compile normative data for MRE-assessed stiffness measurements of the spleen in young adults. Materials and Methods: A total of 100 healthy young Caucasian volunteers (65 females and 35 males) in the age range of 20 to 32 years were enrolled in this study. The participants reported no history of chronic spleen and liver disease, normal alcohol consumption, and a normal diet. The MRE data were acquired by using a 1.5 T whole-body scanner and a 2D GRE pulse sequence with 60 Hz excitation. Spleen stiffness was calculated as a weighted mean of stiffness values in the regions of interest manually drawn by the radiologist on three to five spleen slices. Results: Mean spleen stiffness was 5.09 ± 0.65 kPa for the whole group. Male volunteers had slightly higher splenic stiffness compared to females: 5.28 ± 0.78 vs. 4.98 ± 0.51 kPa, however, this difference was not statistically significant (p = 0.12). Spleen stiffness did not correlate with spleen fat content and liver stiffness but a statistically significant correlation with spleen volume was found. Conclusions: The findings of this study provide normative values for 2D MRE-based measurement of spleen stiffness in young adults, a basis for assessing the value of this biomarker in young patients with portal system pathologies.
Simultaneous Measurements of Noncommuting Observables: Positive Transformations and Instrumental Lie Groups
Authors: Jackson Christopher S. , Caves Carlton M.
Published: August 2023

We formulate a general program for describing and analyzing continuous, differential weak, simultaneous measurements of noncommuting observables, which focuses on describing the measuring instrument autonomously, without states. The Kraus operators of such measuring processes are time-ordered products of fundamental differential positive transformations, which generate nonunitary transformation groups that we call instrumental Lie groups. The temporal evolution of the instrument is equivalent to the diffusion of a Kraus-operator distribution function, defined relative to the invariant measure of the instrumental Lie group. This diffusion can be analyzed using Wiener path integration, stochastic differential equations, or a Fokker-Planck-Kolmogorov equation. This way of considering instrument evolution we call the Instrument Manifold Program. We relate the Instrument Manifold Program to state-based stochastic master equations. We then explain how the Instrument Manifold Program can be used to describe instrument evolution in terms of a universal cover that we call the universal instrumental Lie group, which is independent not just of states, but also of Hilbert space. The universal instrument is generically infinite dimensional, in which case the instrument’s evolution is chaotic. Special simultaneous measurements have a finite-dimensional universal instrument, in which case the instrument is considered principal, and it can be analyzed within the differential geometry of the universal instrumental Lie group. Principal instruments belong at the foundation of quantum mechanics. We consider the three most fundamental examples: measurement of a single observable, position and momentum, and the three components of angular momentum. As these measurements are performed continuously, they converge to strong simultaneous measurements. For a single observable, this results in the standard decay of coherence between inequivalent irreducible representations. For the latter two cases, it leads to a collapse within each irreducible representation onto the classical or spherical phase space, with the phase space located at the boundary of these instrumental Lie groups.
Emulating Non-Hermitian Dynamics in a Finite Non-Dissipative Quantum System
Authors: Flament Eloi , Impens François , Guéry-Odelin David
Published: August 2023

We discuss the emulation of non-Hermitian dynamics during a given time window using a low-dimensional quantum system coupled to a finite set of equidistant discrete states acting as an effective continuum. We first emulate the decay of an unstable state and map the quasi-continuum parameters, enabling the precise approximation of non-Hermitian dynamics. The limitations of this model, including in particular short- and long-time deviations, are extensively discussed. We then consider a driven two-level system and establish criteria for non-Hermitian dynamics emulation with a finite quasi-continuum. We quantitatively analyze the signatures of the finiteness of the effective continuum, addressing the possible emergence of non-Markovian behavior during the time interval considered. Finally, we investigate the emulation of dissipative dynamics using a finite quasi-continuum with a tailored density of states. We show through the example of a two-level system that such a continuum can reproduce non-Hermitian dynamics more efficiently than the usual equidistant quasi-continuum model.
Design and Validation of Software for the Training and Automatic Evaluation of Music Intonation on Non-Fixed Pitch Instruments for Novice Students
Authors: Tejada Jesús , Fernández-Villar María Ángeles
Published: August 2023

Music education, whether professional or amateur, includes learning musical instruments. Intonation is a critical factor in their training. The main objective of this research work is the design and validation of online educational software for the real-time training and evaluation of intonation in non-fixed pitch musical instruments, such as fretted string instruments (violin, viola, and cello) and brass instruments (trumpet, horn, and trombone). This software is intended to create a practice artefact for novice music students. A design sciences research methodology is adopted to achieve a product tested for functionality and usability. Novice students carry out the validation phase through a study consisting of previous practice with the software and the administration of a questionnaire with open-ended items grouped in technical-didactic, emotional, and overall dimensions, plus two additional questions. The results show evidence that the software was well received, confirming previous studies on the design and validation of educational music education software.
Using the Van Hiele Theory to Explain Pre-Service Teachers’ Understanding of Similarity in Euclidean Geometry
Authors: Mbatha Mduduzi , Bansilal Sarah
Published: August 2023

Helping learners to develop a solid grasp of geometric concepts poses a challenge for teachers. Therefore, it is important that teachers have a sound understanding of the geometry they teach. The aim of this qualitative study was to explore pre-service teachers’ (PST’s) understanding of the concept of similarity in Euclidean geometry and to use van Hiele’s theory to explain misconceptions evidenced by the PSTs. Data in this study were collected from 34 first-year PSTs studying for a Bachelor of Education degree in high school mathematics. The authors analysed the written responses to a 13-item worksheet and also conducted interviews with seven of the participants. The analysis of the data was guided by van Hiele’s theory which was used to identify misconceptions amongst PST’s who had not yet developed the appropriate reasoning skills linked to particular van Hiele levels of geometric thought. It was found that these students used reasoning that is characteristic of the elementary levels to make judgments. Many PST’s faced challenges with similarity notation and the process of proving the similarity between two figures. This study recommends that PST’s should be given more opportunities to connect visual and analytic representations of similarity.
An Image Enhancement Method for Side-Scan Sonar Images Based on Multi-Stage Repairing Image Fusion
Authors: Lu Ziwei , Zhu Tongwei , Zhou Huiyu , Zhang Lanyong , Jia Chun
Published: August 2023

The noise interference of side-scan sonar images is stronger than that of optical images, and the gray level is uneven. To solve this problem, we propose a side-scan sonar image enhancement method based on multi-stage repairing image fusion. Firstly, to remove the environmental noise in the sonar image, we perform adaptive Gaussian smoothing on the original image and the weighted average grayscale image. Then, the smoothed images are all processed through multi-stage image repair. The multi-stage repair network consists of three stages. The first two stages consist of a novel encoder–decoder architecture to extract multi-scale contextual features, and the third stage uses a network based on the resolution of the original inputs to generate spatially accurate outputs. Each phase is not a simple stack. Between each phase, the supervised attention module (SAM) improves the repair results of the previous phase and passes them to the next phase. At the same time, the multi-scale cross-stage feature fusion mechanism (MCFF) is used to complete the information lost in the repair process. Finally, to correct the gray level, we propose a pixel-weighted fusion method based on the unsupervised color correction method (UCM), which performs weighted pixel fusion between the RGB image processed by the UCM algorithm and the gray-level image. Compared with the algorithm with the SOTA methods on datasets, our method shows that the peak signal-to-noise ratio (PSNR) is increased by 26.58%, the structural similarity (SSIM) is increased by 0.68%, and the mean square error (MSE) is decreased by 65.02% on average. In addition, the processed image is balanced in terms of image chromaticity, image contrast, and saturation, and the grayscale is balanced to match human visual perception.
Cost-Efficient Two-Level Modeling of Microwave Passives Using Feature-Based Surrogates and Domain Confinement
Authors: Pietrenko-Dabrowska Anna , Koziel Slawomir , Zhang Qi-Jun
Published: August 2023

A variety of surrogate modeling techniques has been utilized in high-frequency design over the last two decades. Yet, the curse of dimensionality still poses a serious challenge in setting up reliable design-ready surrogates of modern microwave components. The difficulty of the modeling task is only aggravated by nonlinearity of circuit responses. Consequently, constructing a practically usable surrogate model, valid across extended ranges of material, geometry, and operational parameters, is far from easy. As a matter of fact, conventional modeling techniques are merely capable of building models for microwave structures featuring a relatively small number of designable parameters within reduced ranges thereof. One possible way of mitigating these obstacles may be the employment of the recently proposed two-stage performance-driven modeling approach. Therein, the surrogate model domain is narrowed down to the section of the space where the vectors of adequate quality are located, thereby permitting significantly reducing the cost of acquiring the training data. Seeking even further cost reduction, this work introduces a novel modeling framework, which exploits problem-specific knowledge extracted from the circuit responses to achieve substantial cost-savings of training data acquisition. In our methodology, the modeling procedure targets response features instead of the complete responses. The response features are the characteristic locations of the circuit response, such as relevant minima or maxima over selected frequency bands. The dependency of the coordinates of the said features on circuit dimensions is considerably less nonlinear than is observed for the complete characteristics, which enables sizable reduction of the data acquisition cost. Numerical validation of our procedure involving three microwave structures corroborates its remarkable efficiency, which allows for setting design-ready surrogates using only a handful of samples.
A Wideband Power Amplifier in 65 nm CMOS Covering 25.8 GHz–36.9 GHz by Staggering Tuned MCRs
Authors: Wang Zhiqiang , Wang Xiaosong , Liu Yu
Published: August 2023

Broadband millimeter-wave power amplifiers have attracted much attention and have wide applications for 5G communication, satellite communication, radar, sensing, etc. Yet, it is challenging to design a power amplifier with broadband small-signal gain and power performance simultaneously. In this study, a transformer-based symmetrical magnetically coupled resonator (MCR) matching network for broadband output matching and stagger-tuned MCRs are used to achieve both broadband small- and large-signal performance. Also, to enhance the gain for the power amplifier, a three-stage common-source pseudo-differential structure is adopted to mitigate the low-gain issue due to stagger tuning, and the shunt resistors aimed to decrease the Q factor of the MCRs. We used the in-phase two-way current combined with microstrip transmission lines to increase the output power. Designed in 65 nm bulky CMOS technology, the power amplifier presents a 3 dB small-signal gain bandwidth from 25.8 GHz to 36.9 GHz, indicating a peak gain of 25.87 dB at 30.5 GHz. The power amplifier demonstrates a 17.84 dBm saturated output power (Psat) at 31 GHz and a 24.37% peak power added efficiency (PAEmax) at 28 GHz. The power amplifier achieves a flat Psat of 17.44 ± 0.4 dBm, a PAEmax of 22.59 ± 1.78%, and an OP1dB of 13.78 ± 0.31 dBm from 26 GHz to 36 GHz.
A Novel Allocation Strategy Based on the Model Predictive Control of Primary Frequency Regulation Power for Multiple Distributed Energy Storage Aggregators
Authors: Mao Tian , He Shan , Guan Yingcong , Liu Mingbo , Zhao Wenmeng , Wang Tao , Tang Wenjun
Published: August 2023

As the amount of distributed energy storage (DES) in a power system continues to increase, it will not be long before there are multiple DES aggregators participating in frequency regulation, and the realization of their coordinated control is a critical topic of current research. This study focused on the primary frequency regulation (PFR) power allocation strategy among multiple DES aggregators participating in PFR. This study first calculated the PFR demand according to a system frequency response model of the power system with DESs. Next, a PFR power allocation model of DES aggregators was developed based on model predictive control. The objective of this model was to minimize the overall frequency regulation cost while satisfying all of the constraints of DESs. Finally, the distributed interior point method was used to solve the model rapidly. The correctness and effectiveness of the proposed model and algorithm were verified on two unified transmission and distribution systems with DES aggregators used to supply the PFR service. The results revealed that the proposed model could effectively allocate PFR power to the various types of energy storage, with the additional benefits of slowing down the shift in the state of charge for energy storage units and ensuring the continuity of energy storage participation in frequency regulation.
Retrofit Analysis of City-Scale Residential Buildings in the Hot Summer and Cold Winter Climate Zone
Authors: Ji Yanfei , Li Guangchen , Su Fanghan , Chen Yixing , Zhang Rongpeng
Published: August 2023

The rising energy consumption in residential buildings within the hot summer and cold winter (HSCW) climate zone, driven by occupants’ pursuit of improved thermal comfort, necessitates effective energy conservation measures. This study established urban building energy models for 32,145 residential buildings in Changsha City, China, and conducted a comprehensive retrofit analysis of seven energy conservation measures (ECMs). Additionally, the study assessed the impact of residents’ conscious energy-saving behaviors concerning air conditioner (AC) control. The research commenced by creating six baseline models representative of the diverse building stock. Identifying seven commonly used ECMs, the study examined the potential of each measure for enhancing energy efficiency. To facilitate the analysis, a dedicated toolkit, AutoBPS-Retrofit, was developed to efficiently modify the baseline model for each ECM. Furthermore, the investigation delved into the investment cost of implementing the ECMs and evaluated their simple payback year (PBP) and net present value (NPV). The results demonstrate that tailored retrofit plans are essential when addressing envelope improvements, varying according to building types and ages. Retrofits targeting lighting systems offer both promising energy savings and favorable economic viability, albeit subject to residents’ preferences. Alternatively, upgrading the AC systems emerges as the most energy-efficient approach, yet the economic assessment raises concerns. The study’s findings offer practical insights for governments seeking to establish effective carbon reduction goals and policies. Moreover, the research can assist energy-saving institutions, real-estate companies, and stakeholders involved in renovation projects by offering guidance in making informed decisions to enhance energy efficiency in city-scale residential buildings.
Solar Energy Harnessing Technologies towards De-Carbonization: A Systematic Review of Processes and Systems
Authors: Nikolaidis Pavlos
Published: August 2023

Solar energy, derived from the inexhaustible energy of the sun, has emerged as a promising solution to mitigate the environmental challenges posed by fossil fuel consumption and global climate change. This work explores the underlying principles of solar energy exploitation, focusing on energy collection technologies as the primary means of solar energy conversion. The physics of the state-of-the-art mechanisms, the photovoltaic effect, and the advancements that have driven the transformation of solar energy into a viable and sustainable alternative energy source are also examined. Through a comprehensive review of relevant literature and pioneering research, this study highlights the immense potential of solar energy and its role in shaping a cleaner, greener future. Towards de-carbonization, the various exploitation technologies are divided into direct and indirect in order to optimize resource utilization. Accounting for the most important advantages presented, solar-based utilization processes are perhaps the only ones that provide access to energy for all to satisfy their vital needs. As nations continue to embrace solar energy and invest in its development, we move closer to achieving a more sustainable and environmentally friendly world for generations to come.
Impact of Distributed Generation on the Effectiveness of Electric Distribution System Reconfiguration
Authors: Gonçalves-Leite Matheus Diniz , Carreño-Franco Edgar Manuel , López-Lezama Jesús M.
Published: August 2023

Distribution system reconfiguration (DSR) is an essential activity in the operation of distribution utilities, usually carried out to lower active power losses and improve reliability metrics. The insertion of distributed generation (DG) units in electric power distribution systems (EPDS) causes the rearrangement of power flows through the conductors and changes the real power losses and voltage profile; therefore, up to a certain point, the insertion of certain quantities of DG may potentially delay or change the reconfiguration strategy of EPDS. This article presents an analysis of the impact of DG, for different locations of the units and different levels of active power supplied by them, on real power losses and on the effectiveness of DSR. The article presents tests with different distribution systems with varying sizes and topologies, showing that the allocation of DG units in buses far from the substation provided the best cost–benefit results. The DSR impact changes depending on the installment location and the generation level of the DG units, corroborating that DSR must be considered and performed using certain criteria, to maximize its efficiency.
Induction and Characterisation of Lignocellulolytic Activities from Novel Deep-Sea Fungal Secretomes
Authors: Dowd Bronwyn , Tuohy Maria G.
Published: August 2023

Fungi are increasingly recognised as being able to inhabit extreme environments. The deep sea is considered an extreme environment because of its low temperatures, high hydrostatic and lithostatic pressures, 3.5% salinity, and low oxygen, nutrient and light availability. Fungi inhabiting the deep sea may have evolved to produce proteins that allow them to survive these conditions. Investigation and characterisation of fungal lignocellulolytic enzymes from extreme environments like the deep sea is needed, as they may have unusual adaptations that would be useful in industry. This work, therefore, aimed to profile in detail the lignocellulolytic capabilities of fungi isolated from deep-sea sediments in the Atlantic Ocean, and a comparative lignocellulolytic terrestrial isolate. The isolates were strains of Emericellopsis maritima, Penicillium chrysogenum, P. antarcticum and Talaromyces stollii. Lignocellulolytic enzyme induction was achieved using liquid-state fermentation (LSF) with wheat bran as the main carbon source, while enzyme characteristics were evaluated using biochemical assays and gel-based proteomics. This study revealed that the isolates were halotolerant, produced xylanase over wide pH and temperature ranges, and produced a variety of glycoside hydrolase and feruloyl esterase activities. The T. stollii secretome demonstrated remarkable levels of exo-glycoside hydrolase activity, with xylanase activity optimum between pH 1.5–6.0 and temperatures between 1–60 °C, making this isolate an ideal candidate for biotechnological applications. This study is the first to quantitatively characterise xylanase activities and exo-glycoside hydrolase activities secreted by E. maritima, P. antarcticum and a marine T. stollii strain. This study is also the first to quantitatively characterise xylanase activities by a marine strain of P. chrysogenum during LSF.
A Global Perspective of the Functional Trait Responses of Graminoids to the Seasonality of Fire
Authors: Mndela Mthunzi , Thamaga Humphrey K. , Gusha Bukho
Published: August 2023

In fire-prone ecosystems, plant resilience to recurrent fires depends on certain fire-adaptive traits. However, how key functional and reproductive traits of graminoids respond to varying burning seasons is poorly understood. This meta-analysis, therefore, unpacks global perspectives on how resprouting, growth, reproductive, and productivity traits of graminoids (grasses and sedges) respond to different burning seasons. We recorded 569 observations from 80 experimental studies comparing graminoid plant trait responses in unburned vs. burned treatments over different seasons of burn. Weighted log response ratios and 95% confidence intervals (95%CI) were analyzed for each plant trait using random effects models and compared across burning seasons. Summer (0.35 (95%CI = 0.25 to 0.46)) and autumn burns (0.24 (95%CI = 0.16 to 0.31)) increased above-ground biomass m−2, while biomass plant−1 was increased only by spring burns (0.27 (95%CI = 0.22 to 0.32)). Bud production plant−1 and tiller−1 were reduced significantly by fire, especially spring, summer, and autumn burns. The shoot height (0.29 (95%CI = 0.17 to 0.41)), leaf length (0.15 (95%CI = 0.11 to 0.20)), and specific leaf area (0.08 (95%CI = 0.06 to 0.09)) increased only under summer burns, while flowering was enhanced by spring (0.19 (95%CI = 0.00 to 0.38)) and autumn burns [0.34 (95%CI = 0.02 to 0.66)]. However, seed production m−2 was reduced by spring and summer burns and the opposite was true for seed production plant−1. Overall, herbaceous plant trait responses to fire varied by the season of burn, disagreeing with the general principle that early spring burning is the best practice. We suggest that a decision on the season of burn should be informed by the objective of burning.
Exploring Biofouling Control by the California Sea Cucumber (Apostichopus californicus) in Integrated Multi-Trophic Aquaculture (IMTA) with Organic Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Montgomery Emaline M. , Cannon Barb L. , Pearce Christopher M.
Published: August 2023

The growth of biofouling on aquaculture infrastructure is a universal challenge. Standard industry practices to remove biofouling in finfish aquaculture typically include in situ net cleaning via power washing. Since those cleaning practices can be potentially harmful to fish-gill health and expensive, development of other non-toxic biofouling controls is an industry priority. Deposit-feeding sea cucumbers are potentially well suited for biofouling control due to their feeding mechanism, but remain relatively untested in this capacity. We examined the use of California sea cucumbers (Apostichopus californicus) to control biofouling on cages containing adult Chinook salmon (Oncorhynchus tshawytscha) at a commercial farming operation. Four cage types were established: cages with salmon and sea cucumbers, cages with salmon only, cages with sea cucumbers only, and cages without either species. Results showed that the sea cucumbers actively fed on biofouling when salmon were absent (~16% cleaner on average) but preferred to consume uneaten feed/faeces at the bottom of the cages, neglecting the biofouling, when the salmon were present. It is hypothesized that biofouling control in cages with salmon may be possible with an increased density of sea cucumbers. This is the first study to examine the use of sea cucumbers as a direct net biofouling control agent with adult fish. Our results will be beneficial for industry to develop standard operating procedures for using California sea cucumbers as a biofouling control and could contribute to the development of a management framework for sea cucumber/salmon integrated multi-tropic aquaculture.
An Assessment of Microplastic Contamination in a Commercially Important Marine Fish, Harpadon nehereus (Hamilton, 1822)
Authors: Prusty Kalpana , Rabari Vasantkumar , Patel Krupal , Ali Daoud , Alarifi Saud , Yadav Virendra Kumar , Sahoo Dipak Kumar , Patel Ashish , Trivedi Jigneshkumar
Published: August 2023

Microplastic (MP) pollution is a prevalent and global threat to fish. MP contamination was investigated in Harpadon nehereus collected from the principal fishing harbors of India’s northwest coast. A total of 213 specimens were collected from the major fishing harbors of Gujarat state (Jakhau, Okha, and Jaffrabad) and Maharashtra state (Mumbai). In the laboratory, the morphometric parameters of the specimens, such as total length and body weight, were measured. The collected specimens were analyzed for MP isolation using the previously documented protocol. MPs were quantified under a stereomicroscope, and physical parameters were recorded. All the examined specimens were found to be contaminated with MPs, with an abundance of 6.98 ± 6.73 MPs/g. The maximum contamination of MPs was recorded at the study site in Jaffrabad, followed by Jakhau, Mumbai, and Okha. Morphometric analysis of MPs revealed threads to be the most dominant shape. Black and blue MPs with a 1–2 mm size were the predominant recorded types. The chemical composition of extracted MPs revealed polyethylene (PE), polystyrene (PS), and polyurethane (PU) as polymer compositions. Conclusively, the findings highlighted a greater menace to seafood safety due to trophic transfer, which causes a hazardous effect on human health.
Characterization of the Key Aroma Compounds in Dong Ding Oolong Tea by Application of the Sensomics Approach
Authors: Wang Daoliang , Wang Cainan , Su Weiying , Lin Chih-Cheng , Liu Wei , Liu Yuan , Ni Li , Liu Zhibin
Published: August 2023

The Dong Ding oolong tea (DDT), grown and produced in Taiwan, is widely appreciated for its unique flavor. Despite its popularity, research on the aroma components of DDT remains incomplete. To address this gap, this study employed a sensomics approach to comprehensively characterize the key aroma compounds in DDT. Firstly, sensory evaluation showed that DDT had a prominent caramel aroma. Subsequent analysis using gas chromatography-olfactory mass spectrometry (GC-O-MS) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS) identified a total of 23 aroma-active compounds in DDT. Notably, three pyrazine compounds with roasted notes, namely 2-ethyl-5-methylpyrazine, 2-ethyl-3,5-dimethylpyrazine, and 2,3-diethyl-5-methylpyrazine, along with seven floral- and fruit-smelling compounds, namely 6-methyl-5-hepten-2-one, 3,5-octadien-2-one, linalool, (E)-linalool oxide, geraniol, (Z)-jasmone, and (E)-nerolidol, were identified as the key aroma compounds of DDT. Omission experiments further validated the significant contribution of the three pyrazines to the caramel aroma of DDT. Moreover, the content of 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, (Z)-jasmone, 6-methyl-5-hepten-2-one and 2-ethyl-5-methylpyrazine was found to be higher in the high-grade samples, while (E)-nerolidol, linalool, geraniol and 3,5-octadien-2-one were found to be more abundant in the medium-grade samples. These findings provide valuable information for a better understanding of the flavor attributes of DDT.
Nano and Technological Frontiers as a Sustainable Platform for Postharvest Preservation of Berry Fruits
Authors: Iñiguez-Moreno Maricarmen , González-González Reyna Berenice , Flores-Contreras Elda A. , Araújo Rafael G. , Chen Wei Ning , Alfaro-Ponce Mariel , Iqbal Hafiz M. N. , Melchor-Martínez Elda M. , Parra-Saldívar Roberto
Published: August 2023

Berries are highly perishable and susceptible to spoilage, resulting in significant food and economic losses. The use of chemicals in traditional postharvest protection techniques can harm both human health and the environment. Consequently, there is an increasing interest in creating environmentally friendly solutions for postharvest protection. This article discusses various approaches, including the use of “green” chemical compounds such as ozone and peracetic acid, biocontrol agents, physical treatments, and modern technologies such as the use of nanostructures and molecular tools. The potential of these alternatives is evaluated in terms of their effect on microbial growth, nutritional value, and physicochemical and sensorial properties of the berries. Moreover, the development of nanotechnology, molecular biology, and artificial intelligence offers a wide range of opportunities to develop formulations using nanostructures, improving the functionality of the coatings by enhancing their physicochemical and antimicrobial properties and providing protection to bioactive compounds. Some challenges remain for their implementation into the food industry such as scale-up and regulatory policies. However, the use of sustainable postharvest protection methods can help to reduce the negative impacts of chemical treatments and improve the availability of safe and quality berries.
Optimization of the Process for Green Jujube Vinegar and Organic Acid and Volatile Compound Analysis during Brewing
Authors: Li Guifeng , Yan Ni , Li Guoqin , Wang Jing
Published: August 2023

Healthy fruit vinegar has become very popular recently in China. This study aimed to produce fruit vinegar with a good taste, high nutritional value, and strong functional properties from green jujube. This study investigated the optimization of the process for green jujube vinegar using response surface methodology. The optimum fermentation parameters for green jujube vinegar were determined as follows: initial alcoholicity 6%, acetobacter 8%, fermentation temperature 32 °C, and time 7 d. The organic acids of the optimized sample were evaluated by HPLC, and the volatile substances were identified and analyzed by HS-SPME and GC-MS during the fermentation and aging of the green jujube vinegar. The results showed that the variation trends of the different organic acids during the making of the green jujube vinegar were significantly different. Organic acids are the key flavor compounds of green jujube vinegar, and their changes were mainly attributed to microbial metabolism. In particular, the green jujube vinegar stood out in terms of volatile aroma compounds, including a total of 61 volatile compounds whose major components were acetic acid, isoamyl acetate, ethyl acetate, 3-hydroxy-2-butanone, methyl palmitate, and ethanol. The results can provide theoretical support for the production of green jujube vinegar.
Asparaginase Treatment of Sea Buckthorn Berries as an Effective Tool for Acrylamide Reduction in Nutritionally Enriched Wholegrain Wheat, Rye and Triticale Biscuits
Authors: Ciesarová Zuzana , Kukurová Kristína , Jelemenská Viera , Horváthová Jana , Kubincová Janka , Belović Miona , Torbica Aleksandra
Published: August 2023

Sea buckthorn pomace is a by-product of juice production, which is still rich in bioactive compounds. After drying, the pomace can be effectively used as a valuable addition to bakery products supporting their nutritional value. However, due to the high content of the amino acid asparagine in sea buckthorn, this promising material contributes to the undesirable formation of acrylamide. To reduce the risk from this potentially carcinogenic compound, enzymatic treatment of sea buckthorn with asparaginase was applied, which resulted in a substantial reduction of asparagine content from 1834 mg/kg in untreated dried sea buckthorn pomace to 89 mg/kg in enzymatically treated dried sea buckthorn pomace. 10% substitution of wholegrain cereal flour with enzymatically treated sea buckthorn pomace powder in rye and triticale biscuits resulted in a 35% reduction in acrylamide content, in the case of wholegrain wheat biscuits up to a 64% reduction, compared to biscuits with untreated sea buckthorn pomace powder. This study confirmed that treating fruit with asparaginase is an effective way to reduce health risk caused by acrylamide in biscuits enriched with nutritionally valuable fruit pomace.
Optimization of the Use of a Commercial Phage-Based Product as a Control Strategy of Listeria monocytogenes in the Fresh-Cut Industry
Authors: Gómez-Galindo Marisa , Truchado Pilar , Allende Ana , Gil Maria I.
Published: August 2023

A commercial phage biocontrol for reducing Listeria monocytogenes has been described as an effective tool for improving fresh produce safety. Critical challenges in the phage application must be overcome for the industrial application. The validation studies were performed in two processing lines of two industry collaborators in Spain and Denmark, using shredded iceberg lettuce as the ready-to-eat (RTE), high process volume product. The biocontrol treatment optimized in lab-scale trials for the application of PhageGuard ListexTM was confirmed in industrial settings by four tests, two in Spain and two in Denmark. Results showed that the method of application that included the device and the processing operation step was appropriate for the proper application. The proper dose of Phage Guard ListexTM was reached in shredded iceberg lettuce and the surface was adequately covered for the successful application of phages. There was no impact on the headspace gas composition (CO2 and O2 levels), nor on the color when untreated and treated samples were compared. The post-process treatment with PhageGuard ListexTM did not cause any detrimental impact on the sensory quality, including flavor, texture, browning, spoilage, and visual appearance over the shelf-life as the phage solution was applied as a fine, mist solution.
Pulsed Electric Field (PEF) and High-Power Ultrasound (HPU) in the Hurdle Concept for the Preservation of Antioxidant Bioactive Compounds of Strawberry Juice—A Chemometric Evaluation—Part I
Authors: Bebek Markovinović Anica , Stulić Višnja , Putnik Predrag , Birkić Anamaria , Jambrović Maja , Šaško Dolores , Ljubičić Josipa , Pavlić Branimir , Herceg Zoran , Bursać Kovačević Danijela
Published: August 2023

This work investigated the influence of pulsed electric field (PEF) and high-power ultrasound (HPU) combined with hurdle technology to preserve the bioactive compounds (BACs) content and antioxidant activity in stored strawberry juices. PEF was performed at 30 kV cm−1, 100 Hz during 1.5, 3, and 4.5 min, while HPU was performed at 25% amplitude and 50% pulse during 2.5, 5.0, and 7.5 min. Total phenols and hydroxycinnamic acids were the most stable BACs during the hurdle treatment without influence of the duration of both treatments, while flavonols and condensed tannins showed a significant stability dependence with respect to the duration of both treatments. Total phenols were also stable during storage, in contrast to the individual groups of BACs studied. A chemometric approach was used to optimize the parameters of the hurdle treatments with respect to the highest level of BACs and the antioxidant activity of the treated juices. In general, shorter treatment times in the hurdle approach resulted in better stability of BACs and antioxidant activity. The hurdle technology investigated in this study has the strong potential to be an excellent concept for optimizing the operating parameters of PEF and HPU technologies in the preservation of functional foods.
Investigating the Role Played by Osmotic Pressure Difference in Osmotic Dehydration: Interactions between Apple Slices and Binary and Multi-Component Osmotic Systems
Authors: Wang Xiaojuan , Feng Hao
Published: August 2023

This study was performed to investigate a strategy to interpret the osmotic dehydration (OD) process through a focused exploration of osmotic pressure dynamics. The investigation first delved into the relationship between dehydration rate and the osmotic pressure difference between food and an osmotic solution. Apple slices was used as a model food material, and the OD process was conducted via sucrose, glucose, and maltose. The positive correlation between the osmotic pressure difference between food and osmotic solution and the dehydration rate suggested that this pressure difference served as the primary driving force for mass transfer within the OD process; for example, in 60% wt sucrose solution, the osmotic pressure of the solution decreased from 15.60 MPa to 12.98 MPa in the first 30 min, while the osmotic pressure of fresh apple slices increased from 1.49 MPa to 4.05 MPa; and this correlation between dehydration rate and osmotic pressure difference in product tissue and osmotic solution followed a linear relationship. Then, the study went further to investigate augmenting osmotic pressure of osmotic solution (sucrose and fructose) by adding auxiliary solutes (sodium chloride and calcium lactate). The results showcased that augmenting osmotic pressure within a sugar-based solution could be realized through the introduction of additive solutes, and what is more important is that this augmentation displayed a synergistic effect, which was more pronounced in solutions of lower sugar concentration. For example, the osmotic pressure of 45%wt fructose solution was 8.88 MPa, which could be increased to 10.05 MPa by adding 0.075% wt NaCl, while adding 0.075% wt NaCl to 59.14% wt fructose solution could increase osmotic pressure from 20.57 MPa to 21.22 MPa. In essence, this study proposed a strategic approach to studying the OD process by spotlighting osmotic pressure as a pivotal factor.
Expression and Transformation Characteristics of a Novel Glutamic Acid Decarboxylase LcGAD10s and Its Application on Sufu Processing
Authors: Chen Zhou , Wang Run , Song Yanyin , Ma Aijin , Li Siting , Jia Yingmin
Published: August 2023

Gamma-aminobutyric acid (GABA) is an important non-proteinogenic amino acid and a potent bioactive compound with many anti-hypertensive and anti-depressant activities. The bioconversion of GABA by glutamic acid decarboxylase (GAD) has been eagerly studied. Herein, novel pyridoxal-5-phosphate monohydrates (PLP)-dependent GAD, which is not quite similar to reporting, was cloned from Latilactobacillus curvatus and efficiently expressed in E. coli. The conveniently purified GAD (designated LcGAD10s) appeared as a single protein on SDS-PAGE with a molecular mass of 52.0 kDa. LcGAD10s exhibited a specific activity of 303.7 U/mg after purification by Ni–IDA affinity chromatography, with optimal activity at 55 °C and pH 5. LcGAD10s displayed excellent temperature (50 °C) and pH (4–8) stability which relative activity above 80% and 70%, respectively. The enzymatic activity was, respectively, increased and depressed by 130%, and 24% in the presence of Mn+ and Cu2+. Enzyme activity over 90% can be achieved by adding at least 25 mM of PLP. LcGAD10s was able to efficiently transform 15 g/L GABA with a single-factor optimized reaction of pH (5), temperature (50 °C), time (2 h), LcGAD10s dosage (0.4 U) and monosodium glutamate level (5 g/L). Additionally, LcGAD10s can be applied to a tofu fermentation system to achieve GABA conversion and achieved 14.9 mg/g of GABA conversion when added at 2 U/mL, which is higher than most of the commercial sufu and previous application reports, increasing its functional substances.