bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimentally Determining Optimal Conditions for Mapping Forage Fish with RPAS
Authors: Houtman Nicola R. , Yakimishyn Jennifer , Collyer Mike , Sutherst Jennifer , Robinson Cliff L. K. , Costa Maycira
Published: December 2022

RPAS (Remotely piloted aircraft systems, i.e., drones) present an efficient method for mapping schooling coastal forage fish species that have limited distribution and abundance data. However, RPAS imagery acquisition in marine environments is highly dependent on suitable environmental conditions. Additionally, the size, color and depth of forage fish schools will impact their detectability in RPAS imagery. In this study, we identified optimal and suboptimal coastal environmental conditions through a controlled experiment using a model fish school containing four forage fish-like fishing lures. The school was placed at 0.5 m, 1.0 m, 1.5 m, and 2.0 m depths in a wide range of coastal conditions and then we captured RPAS video imagery. The results from a cluster analysis, principal components, and correlation analysis of RPAS data found that the optimal conditions consisted of moderate sun altitudes (20–40°), glassy seas, low winds (<5 km/h), clear skies (<10% cloud cover), and low turbidity. The environmental conditions identified in this study will provide researchers using RPAS with the best criteria for detecting coastal forage fish schools.
A New Method for Surveying the World’s Smallest Class of Dragonfly in Wetlands Using Unoccupied Aerial Vehicles
Authors: Niwa Hideyuki , Hirata Takumi
Published: December 2022

Field surveys in wetlands are limited by the difficulty in accessing the site, hazards during surveys, and the risk of disturbing the ecosystem. Thus, the use of unoccupied aerial vehicles (UAVs) can overcome these limiting factors and can assist in monitoring small organisms, such as plants and insects, that are unique to wetlands, aiding in wetland management and conservation. This study aimed to demonstrate the effectiveness of a survey method that uses a small drone equipped with a telephoto lens to monitor dragonflies, which are unique to wetlands and have been difficult to survey quantitatively, especially in large wetlands. In this study, the main target species of dragonflies was Nannophya pygmaea, which is the world’s smallest dragonfly (about 20 mm long). The study area was Mizorogaike wetland (Kita Ward, Kyoto City, Japan). The UAV was flown at a low speed at an altitude of 4 m to 5 m, and images were taken using 7× telephoto lens on Mavic 3 (7× optical and 4× digital). A total of 107 dragonflies of seven species were identified from the photographs taken by the drone. N. pygmaea, about 20 mm long, was clearly identified. Eighty-five dragonflies belonging to N. pygmaea were identified from the images. Thus, by using a small drone equipped with a telephoto lens, the images of N. pygmaea were captured, and the effects of downwash and noise were reduced. The proposed research method can be applied to large wetlands that are difficult to survey in the field, and can thus provide new and important information pertaining to wetland management and conservation. This research method is highly useful for monitoring wetlands as it is non-invasive, does not require the surveyor to enter the wetland, requires little research effort, and can be repeated.
Practically Robust Fixed-Time Convergent Sliding Mode Control for Underactuated Aerial Flexible JointRobots Manipulators
Authors: Rsetam Kamal , Cao Zhenwei , Wang Lulu , Al-Rawi Mohammad , Man Zhihong
Published: December 2022

The control of an aerial flexible joint robot (FJR) manipulator system with underactuation is a difficult task due to unavoidable factors, including, coupling, underactuation, nonlinearities, unmodeled uncertainties, and unpredictable external disturbances. To mitigate those issues, a new robust fixed-time sliding mode control (FxTSMC) is proposed by using a fixed-time sliding mode observer (FxTSMO) for the trajectory tracking problem of the FJR attached to the drones system. First, the underactuated FJR is comprehensively modeled and converted to a canonical model by employing two state transformations for ease of the control design. Then, based on the availability of the measured states, a cascaded FxTSMO (CFxTSMO) is constructed to estimate the unmeasurable variables and lumped disturbances simultaneously in fixed-time, and to effectively reduce the estimation noise. Finally, the FxTSMC scheme for a high-order underactuated FJR system is designed to guarantee that the system tracking error approaches to zero within a fixed-time that is independent of the initial conditions. The fixed-time stability of the closed-loop system of the FJR dynamics is mathematically proven by the Lyapunov theorem. Simulation investigations and hardware tests are performed to demonstrate the efficiency of the proposed controller scheme. Furthermore, the control technique developed in this research could be implemented to the various underactuated mechanical systems (UMSs), like drones, in a promising way.
Ascertaining the Online Learning Behaviors and Formative Assessments Affecting Students’ Academic Performance during the COVID-19 Pandemic: A Case Study of a Computer Science Course
Authors: Ting Tin Tin , Teh Shi Lin , Wee Mee Chin
Published: December 2022

Prior education research has focused on using learning analytics to predict the academic performance of Massive Online Learning Courses (MOOCs) and e- learning courses in universities. There is limited research on online learning that has been transitioned from physical classes and that has continued to use active learning approaches in an online environment. This study aims to determine the variables affecting students’ academic performance for a computing course in a research-intense university during the COVID-19 pandemic. Variables that are indicative of self-regulated learning such as time management, frequency of accessing learning materials and the Learning Management System (LMS), participation in assessment activities and discussions, and the results of formative assessments were extracted from the LMS reports and log files to predict the students’ total marks and final exam results. The findings revealed that good time management and active participation are important for academic success. The results also supported the model for the early prediction of summative assessment performance using formative assessment results. Additionally, this study concludes that the gap in predictive power between formative assessment results and online learning behaviors is small. This research is considered unique because it demonstrates predictive models for students’ academic success for an institution that was forced to transition from physical to online learning. It highlights the importance of self-regulated learning behavior and formative assessments in the contemporary era.
An Improved Whale Optimizer with Multiple Strategies for Intelligent Prediction of Talent Stability
Authors: Li Hong , Ke Sicheng , Rao Xili , Li Caisi , Chen Danyan , Kuang Fangjun , Chen Huiling , Liang Guoxi , Liu Lei
Published: December 2022

Talent resources are a primary resource and an important driving force for economic and social development. At present, researchers have conducted studies on talent introduction, but there is a paucity of research work on the stability of talent introduction. This paper presents the first study on talent stability in higher education, aiming to design an intelligent prediction model for talent stability in higher education using a kernel extreme learning machine (KELM) and proposing a differential evolution crisscross whale optimization algorithm (DECCWOA) for optimizing the model parameters. By introducing the crossover operator, the exchange of information regarding individuals is facilitated and the problem of dimensional lag is improved. Differential evolution operation is performed in a certain period of time to perturb the population by using the differences in individuals to ensure the diversity of the population. Furthermore, 35 benchmark functions of 23 baseline functions and CEC2014 were selected for comparison experiments in order to demonstrate the optimization performance of the DECCWOA. It is shown that the DECCWOA can achieve high accuracy and fast convergence in solving both unimodal and multimodal functions. In addition, the DECCWOA is combined with KELM and feature selection (DECCWOA-KELM-FS) to achieve efficient talent stability intelligence prediction for universities or colleges in Wenzhou. The results show that the performance of the proposed model outperforms other comparative algorithms. This study proposes a DECCWOA optimizer and constructs an intelligent prediction of talent stability system. The designed system can be used as a reliable method of predicting talent mobility in higher education.
Performance of Millimeter Wave Dense Cellular Network Using Stretched Exponential Path Loss Model
Authors: Mariam Hira , Ahmed Irfan , Ali Sundus , Aslam Muhammad Imran , Rehman Ikram Ur
Published: December 2022

Future wireless networks are expected to be dense and employ a higher frequency spectrum such as millimeter wave (mmwave) to support higher data rates. In a dense urban environment, the presence of obstructions causes the transmissions between the user equipment and base stations to transit from line-of-sight (LOS) to non-LOS (NLOS). This transit hence emphasizes the significance of NLOS links for reliable mmwave communication. The work presented in this paper investigates the downlink performance of a mmwave cellular system by modeling the NLOS channel using stretched exponential path loss model (SEPLM) and employing a 3GPP distance-dependent LOS probability function. This path loss model has the inherent ability to define short ranges as well as obstructions in the environment as a function of its parameter resulting in a more realistic performance analysis. The path loss model is first validated for NLOS link using a data set from an open-source mmwave channel simulator. Then, a mathematical model incorporating LOS and NLOS transmissions is developed to study the impact of path loss on signal-to-interference-plus-noise (SINR) coverage probability and area spectral efficiency (ASE). The proposed framework can provide coverage performance indication over various blockage environments. Our results demonstrate that SINR coverage probability decreases exponentially with increasing base station density. Moreover, ASE initially increases with increasing BS density and is maximized for a particular density value, after which it converges to zero for higher densities. The results are also benchmarked with the existing path loss model of mmwave cellular system with different exponents for LOS and NLOS paths. It was observed that as the base station density increases, the SINR degrades more rapidly when using SEPLM as compared to the existing mmwave path loss model.
Modeling Cultural Keystone Species for the Conservation of Biocultural Diversity in the Afroalpine
Authors: Chengere Shambel Alemu , Steger Cara , Gebrehiwot Kflay , Nemomissa Sileshi , Dullo Bikila Warkineh
Published: December 2022

Climate warming threatens the future sustainability of mountains, and tropical mountains are particularly threatened with loss of biodiversity and associated ecosystem services. Conservation biologists increasingly turn to habitat suitability models to guide the establishment and assessment of protected area networks to protect the highest number of species, yet this focus often neglects the values, attitudes, and beliefs of the people living around protected areas. If we consider protected areas as dynamic social–ecological systems, habitat suitability modeling for conservation planning must pay greater attention to the role of biocultural diversity, rather than biodiversity alone. Here, we describe a conservation assessment of the Afroalpine grassland ecosystem in the northern highlands of Ethiopia. We use a cultural keystone species known as guassa grass (Festuca macrophyhlla) to focus our modeling efforts and evaluate the potential distribution of this endemic species in relation to current national and community-based protected areas. Our model performed highly according to the area under the curve (AUC = 0.96), yet nearly 80% of highly suitable guassa habitat falls outside the range of our training data and thus must be interpreted conservatively. We found that guassa grass distribution is primarily limited by low mean temperature in the warmest quarter (BIO10, 36.7%), high precipitation in the wettest quarter (BIO16, 21%), and low precipitation in the driest quarter (BIO17, 15.6%). As climate change causes rapid warming at high elevations and alters rainfall patterns in the Ethiopian highlands, we urge managers to carefully monitor the changing populations of guassa grass to evaluate whether the species is experiencing an extinction debt. We also recommend four additional areas as potential community-based conservation areas, with government and NGO support for peer-to-peer communication networks. Spatially explicit modeling may be a valuable tool to determine whether these existing and proposed protected areas can sustain future populations of guassa grass.
Douglas Fir Multiproxy Tree-Ring Data Glimpse MIS 5 Environment in the U.S. Pacific Northwest
Authors: Panyushkina Irina P. , Leavitt Steven W. , Meko David M. , Black Bryan A. , Jull A. J. Timothy , Van de Water Peter , Squire Joe , Testa Nicholas R.
Published: December 2022

Proxy records from the late Quaternary help in understanding climate variability on extended time scales. An ancient landslide deposit in Oregon U.S.A. preserved large logs from Douglas fir trees (Pseudotsuga menziesii (Mirb.) Franco) and afforded an opportunity to explore the response of tree growth to climate on annual and decadal scales. High-precision radiocarbon dating indicates an age exceeding 63 ka, i.e., the trees grew within the generally cool Marine Isotope Stage 5 (MIS 5), likely during a warmer interval optimal for Douglas fir establishment. This would include the prolonged warm MIS 5e (ca. 110–130 ka), corresponding approximately to the Eemian interglacial, which was warm like the current Holocene interglacial. A 297-year tree-ring width chronology from 12 Douglas fir logs and 227-year tree-ring δ13C and δ18O records are analyzed with spectral and wavelet analysis. Variance of the ancient rings is consistent with modern Douglas fir growth sensitive to moisture and ecological disturbances. Spectra of ancient and modern chronologies are dominated by low frequencies with significant spectral peaks appearing at high frequencies (2.1–4 years) and cyclic behavior transient over centuries. It is conceivable that the O-isotopes track moisture and that C-isotopes track temperature or sunlight. The findings illustrate the challenges in assessing the response of ancient tree-ring properties to late Quaternary climate variability.
Effects of Larix olgensis Henry Stumps and Coarse Roots on Phosphorus Fractions and Availability in Plantation Microsite Soils
Authors: Yue Yang , Men Xiuli , Sun Zhihu , Chen Xiangwei
Published: December 2022

This study quantified the horizontal influence range of larch stumps and coarse roots on the phosphorus (P) fraction and availability of microsite soils and explored whether this influence range changes with different plantation types. The total P, available P and P fractions were measured in microsite soils at 0–75 cm horizontal distances from stumps and coarse roots at soil depths of 0–40 cm in a pure larch (Larix olgensis Henry) plantation and a mixed larch–ash (Fraxinus mandshurica Rupr.) plantation. Soils at horizontal distances of 85–95 cm from the stumps and coarse roots were used as the controls. Larch stumps and coarse roots affected the total P concentration at depths of 0–40 cm in the mixed plantations, and the maximum horizontal influence range reached 75 cm. However, in the pure plantation, only the total P at 0–10 cm depths were affected, and the maximum influence range was 35 cm. The NaOH-Pi and NaOH-Po changes in the pure plantation were similar to those of total P, while those of HCl-Pi, HCl-Po and NaHCO3-Po in the mixed plantation were similar to those of total P. Larch stumps and coarse roots could affect the total P and P fraction concentrations in microsite soils. The horizontal distance of soil total P and P fractions concentrations affected by larch stumps and coarse roots in the mixed plantation was greater than that in the pure plantation. These results suggest that the position of stumps and coarse roots should be considered when reforestation sites are selected.
Causes of Changing Woodland Landscape Patterns in Southern China
Authors: Lin Jianping , Zhu Chenhui , Deng Aizhen , Zhang Yunping , Yuan Hao , Liu Yangyang , Li Shurong , Chen Wen
Published: December 2022

Forests are composed of landscape spatial units (patches) of different sizes, shapes, and characteristics. The forest landscape pattern and its trends are closely related to resistance to disturbance, restoration, stability, and the biodiversity of the forest landscape and directly influence the benefits and sustainable exploitation of forest landscape resources. Therefore, forest landscape patterns and the driving forces have increasingly attracted the attention of researchers. The present study analyzed the spatial and temporal dynamics of woodland landscape patterns in typical hilly mountainous areas in southern China using ArcGIS, landscape pattern index, and morphological spatial pattern analysis. Meanwhile, a logistic regression model was used to analyze the drivers of woodland change in Anyuan County from three aspects: natural, geographic location, and socio-economic conditions. The total area of woodland decreased during the 10-year study period, with a net decrease of 4959.27 ha, mainly due to conversion into cultivated land, garden land, and construction land. Patch density, edge density, and aggregation index of woodlands increased over time, indicating enhanced fragmentation, stable and complex patch edges, and increased patch connectivity. Conversely, the highest patch index values exhibited decreasing trends, indicating decreases in the dominant patch type. Morphological spatial pattern analysis results showed that the core area was dominant and the islet area increased over time, which also indicates enhanced fragmentation. Forest landscape change is the result of environmental change, ecological processes, and human disturbance, with geographical location and social economy having greater influences on forest landscape change. Human activities such as navel orange cultivation, returning cultivated land to forest, and land occupation for construction were the major factors driving woodland change. The results provide reference that could facilitate forest management and sustainable forest resource utilization.
Plant Functional Trait Responses to Dolomite and Limestone Karst Forests in Southwest China
Authors: Zhou Hua , Xu Xuelei , Jiang Xia , Ding Bo , Wu Peng , Ding Fangjun
Published: December 2022

Southwest China is distributed with the largest area of limestone and dolomite karst landscapes in the world, and its ecological environment is very fragile; the problem of rock desertification is particularly prominent. Karst lithological differences make habitats and soil heterogeneity more complex, and vegetation has developed certain morphological and physiological structural characteristics to adapt to these special environments, which will most likely lead to differentiation in vegetation functional characteristics, such as seed size, wood density, life type and flowering time, thus affecting the number and growth of seedlings and young trees and the future succession potential of forest stands in karst-vegetation restoration. Therefore, it is important to understand the differences in species composition and the functional characteristics of dolomite and limestone karst forests. Over a 2-year period, we investigated a total of 3170 individuals from 123 species and analyzed the relationship between the species compositions and the functional characteristics of two karst-forest areas with different lithology (i.e., limestone and dolomite karst). It was found that the average number of species with medium-diameter seeds and medium wood density in dolomite plots was obviously greater than the average number of species in limestone plots, but this reached no significant difference. However, with the gradual restoration of each forest, the height and carbon sequestration capacity of the trees began to diverge, with the relative abundance of species with tall trees and high wood density being significantly higher in limestone plots than in dolomite plots. The species richness of evergreen trees was significantly higher in the limestone plots than in the dolomite plots. There was no significant difference in the relative species richness of flowering plants in the two karst-forest areas during spring–summer and winter–spring seasons; however, the species richness of flowering plants in the limestone karst forests was significantly higher than that of flowering plants in the dolomite karst forests during summer and autumn seasons. These significant traits were very closely related to the species richness of the understory plants. Further insight into the temporal aspects of karst-forest succession is needed to grasp how functional traits affect the restorations of different lithological karst forests to their primary states.
Mycorrhizal Fungi Synergistically Promote the Growth and Secondary Metabolism of Cyclocarya paliurus
Authors: Zhao Tingting , Yu Bangyou , Zhang Mengjia , Chen Shuying , Deng Bo
Published: December 2022

Cyclocarya paliurus has traditionally been used as medicine or a nutraceutical food. This study aims at investigating whether the growth and secondary metabolism of C. paliurus could be simultaneously promoted by inoculating with mycorrhizal fungi, and if so, to uncover the underlying regulatory mechanism. A mycorrhizal microbial inoculum, consisting of the superficial layer fine roots and rhizosphere soil collected from the natural forest of C. paliurus, was used to infect aseptic seedlings of C. paliurus. Roots of aseptic seedlings were successfully infected by mycorrhizal fungi with a 59.7% colonization rate. For mycorrhizal seedlings of C. paliurus, the induced endogenous auxin, net photosynthetic rate, nitrogen absorption, and growth-related genes resulted in a significantly higher growth and biomass accumulation. In addition, a systemic defense response was observed in response to mycorrhizal fungal colonization, such that jasmonic acid biosynthesis and signaling were induced and the biosynthesis of secondary metabolites and antioxidant systems were up-regulated. The improved growth and accumulation of secondary metabolites ultimately facilitated the yield of health-promoting substrates per plant. Overall, mycorrhizal fungal colonization had a significant positive effect both on growth and production of secondary metabolites in C. paliurus. The results can provide the basis for overcoming the limitation of soil nutrient regulation in cultivation practice and offering a simpler alternative to improve the quality of medicinal plants.
Effect of Formic Acid and Inoculants on Microbial Community and Fermentation Profile of Wilted or Un-Wilted Italian Ryegrass Silages during Ensiling and Aerobic Exposure
Authors: Ran Qifan , Guan Hao , Li Haiping , He Wei , Zhu Ruifen , Zhang Li , Huang Yong , Xu Yuandong , Fan Yan
Published: December 2022

Wilted (around 35% DM) or un-wilted (around 35% DM) Italian ryegrass treated with three additives (formic acid, FA; Lactobacillus plantarum, LP; Lactobacillus buchneri, LB) was utilized to evaluate the effects of the dry matter (DM) contents on the microbial community and fermentation characteristics, which was ensiled for 60 days in a laboratory-scale silo, followed by 3 days of aerobic exposure. Significantly lower pH and higher lactic acid (LA) contents were observed in the LP-treated group ensiled at both DM contents (differences were significant when p < 0.05). The contents of LA, acetic acid (AA), numbers of lactic acid bacteria (LAB) and ammonia nitrogen (NH3-N) in the FA-treated group were significantly lower than those in other treatments (p < 0.05). L. buchneri was the dominant bacteria after 60 days fermentation, while Enterobacteria became prevalent after 3 days of aerobic exposure. L. buchneri was found in the LB-treated group with higher acetic acid. Although the best fermentation quality was observed in the LP-treated silages, the aerobic stability was lowest compared to other groups (p < 0.05). In conclusion, our findings suggest that the DM content of Italian ryegrass affected its epiphytic microbial community and the effectiveness of the different type of additives. Formic acid was more suitable for un-wilted Italian ryegrass silage, L. plantarum had a better effect in wilted Italian ryegrass silage, and L. buchneri prolonged the aerobic stability of Italian ryegrass. DM content and purpose of ensiling should be the key factors for choosing different types of additives for Italian ryegrass silage.
Cyber-Physical Systems: Prospects, Challenges and Role in Software-Defined Networking and Blockchains
Authors: Ghosh Uttam , Tosh Deepak , Qureshi Nawab Muhammad Faseeh , Bashir Ali Kashif , Pathan Al-Sakib Khan , Ning Zhaolong
Published: December 2022

In recent years, cyber-physical systems (CPSs) have gained a lot of attention from academia, industry and government agencies, considered to be the world’s third wave of information technology, following computers and the internet [...]
Study on Temperature Attenuation in Diagonal Ventilation Network during Fire
Authors: Li Junqiao , Zhang Wei , Li Yucheng
Published: December 2022

The interaction between ventilation and fire development in diagonal pipe networks makes the study of temperature characteristics extremely complex. The thermodynamic effect caused by high temperature will change the original ventilation state, cause smoke flow retrogression and airflow reversal, and expand the disaster range. Therefore, exploring the temperature attenuation characteristics in diagonal pipe networks is necessary. In this article, the temperature distribution and attenuation in a diagonal pipe network are studied using the numerical simulation method based on the theoretical model of temperature attenuation in a single roadway. In the diagonal branch, the St number in the temperature attenuation model is optimized. The temperature attenuation of the left and right paths can be divided into two stages. The optimal St number of the temperature attenuation model under different wind speeds in the left way is determined. The fitting relationship of wind speed, distance, and temperature in the first stage of the right way is established, and the fire source distance in the second stage of the right way has the most significant influence on the temperature attenuation by using the method of multivariate statistics. The temperature of the smoke backflow front in the left and right paths decreases gradually with the increase in the fire source, and the temperature of the smoke backflow front in the left way is higher than that in the right way.
The Use of Fish Scale Hormone Concentrations in the Assessment of Long-Term Stress and Associated Adverse Effects on Reproductive Endocrinology
Authors: Kennedy Emily K. C. , Janz David M.
Published: December 2022

Investigation of the use of fish scales as a medium for non-lethal biomonitoring has recently commenced. Fish scales have been shown to incorporate cortisol over longer periods of time than blood and thus provide a promising means of assessing long-term stress in many species of teleost fish. However, while cortisol is a major mediator of the stress response in fishes, downstream effects of chronic stress on reproduction can involve gonadal steroids such as progesterone and testosterone. The quantification of these additional hormones alongside cortisol could therefore allow for the assessment of both stress and consequential reproductive alterations. To investigate these concepts, we artificially elevated circulating cortisol, progesterone, and testosterone in rainbow trout (Oncorhynchus mykiss) using coconut oil implants for three weeks. Following this we quantified these three hormones as well as 11-ketotestosterone, a potent androgen in teleost fishes. In all cases serum samples reflected a significant increase in the injected hormone confirming the efficacy of this method; however, this did not result in significantly elevated scale concentrations of the same hormone in all cases. As the stress and reproductive axes are closely integrated, these findings are likely a result of interactions along the steroidogenic pathway indicating that a further investigation of the relationship between scale concentrations of these hormones and actual physiological processes is required. Nevertheless, the successful quantification of both stress and gonadal steroid hormones within the scale suggests that such measurements could provide a novel and informative tool in the assessment of long-term stress and the resulting effects on reproductive endocrinology in teleost fishes.
Isolation, Identification, and Pathogenicity of Aeromonas veronii, the Causal Agent of Hemorrhagic Septicemia in Channel Catfish (Ictalurus punctatus) in China
Authors: Qin Gaixiao , Xu Jin , Ai Xiaohui , Yang Yibin
Published: December 2022

Herein, we isolated the pathogenic strain ZZ051 from hemorrhagic channel catfish (Ictalurus punctatus). Physiological and biochemical identification, 16S rRNA gene sequence analysis, and MALDI-TOF-MS showed that the ZZ051 strain was Aeromonas veronii. After artificial infection, the diseased fish showed symptoms similar to the natural disease, and the characteristics of the bacteria reisolated from the tissues were the same as those of the original infection, indicating that the isolated strain ZZ051 was the pathogen responsible for the channel catfish disease. The ZZ051 isolate was highly sensitive to enrofloxacin but resistant to florfenicol. This study provided a theoretical basis for preventing and controlling hemorrhagic disease in channel catfish.
First Report on Genome Analysis and Pathogenicity of Vibrio tubiashii FP17 from Farmed Ivory Shell (Babylonia areolata)
Authors: Dai Chen , Li Xiaoxin , Luo Dapeng , Liu Qingming , Sun Yun , Tu Zhigang , Shen Minghui
Published: December 2022

Ivory shell (Babylonia areolata) is a commercially important aquaculture species mainly found on the southeast coast of China. However, it has been greatly affected by vibriosis in recent years. In this study, FP17 (a potential pathogen) was isolated from a dying ivory shell with “acute death syndrome” and confirmed as a pathogen via infectious experiment. Furthermore, phylogenetic analysis based on the average nucleotide identity (ANI) sequencing of the 16S rRNA gene and housekeeping genes (ftsz, gapA, gyrB, mreB, pyrH, rpoA, and topA) indicated that FP17 was identical to Vibrio tubiashii. Transmission electron microscopy showed that FP17 is curved and has a short rod shape, with a single flagellum. Besides, the calculated LD50 after the intramuscular injection of FP17 was 2.11 × 106 CFU/g at 14 d. The genome of the FP17 strain consists of two chromosomes and one plasmid with 5,261,336 bp and 45.08% GC content, including 4824 open reading frames (ORFs) and 150 non-coding RNAs (ncRNA). Genome mining revealed that 120 candidate gene clusters, including vibrioferrin and flagellum-related proteins, are responsible for virulence. Comparative genomic analysis showed that vibrioferrin genes, such as pvs and type Ⅵ secretion system protein genes (vas), are specific in V. tubiashii FP17 but not in the ATCC19109 strain. Furthermore, 92 antimicrobial resistance (AMR) genes, such as tufA, tet(35), crp, etc., were mapped within the genome as the potential candidate for virulence, consistent with antibiotic susceptibility assay. This is the first study to describe the complete genome sequence of V. tubiashii infecting ivory shell. The genetic characteristics, virulence factors, and antimicrobial resistance of the V. tubiashii strain FP17 were also explored.
Efficacy of Different Routes of Formalin-Killed Vaccine Administration on Immunity and Disease Resistance of Nile Tilapia (Oreochromis niloticus) Challenged with Streptococcus agalactiae
Authors: Linh Nguyen Vu , Dien Le Thanh , Dong Ha Thanh , Khongdee Nuttapon , Hoseinifar Seyed Hossein , Musthafa Mohamed Saiyad , Dawood Mahmoud A. O. , Van Doan Hien
Published: December 2022

Vaccines prepared from formalin-killed Streptococcus agalactiae were administered to Nile tilapia (Oreochromis niloticus) via three different routes: immersion in a water-based vaccine, injection with an oil-based vaccine, and as a water-based oral vaccine. All vaccination treatments increased lysozyme and peroxidase activity in skin mucus of Nile tilapia by 1.2- to 1.5-fold compared to their activities in unvaccinated control fish. Likewise, alternative complement, phagocytosis, and respiratory burst activities in the blood serum of the vaccinated fish were 1.2- to 1.5-times higher than in the unvaccinated fish. In addition, the expression transcripts of interleukin-1 (IL-1), interleukin-8 (IL-8), and lipopolysaccharide-binding protein (LBP) were 2.3- to 2.9-fold higher in the vaccinated fish compared to those in the unvaccinated control. The unvaccinated fish challenged with Streptococcus agalactiae had a survival rate of 25% compared to a survival rate of 78–85% for the vaccinated fish. The differences between the unvaccinated and vaccinated fish were all statistically significant, but there was no significant difference in any of the indicators of immunity between the three vaccinated groups. Collectively, these results confirm that vaccination with formalin-killed Streptococcus agalactiae significantly improved the resistance of Nile tilapia to infection by the pathogen. Overall, the efficacy of oral administration of the vaccine was comparable to that of vaccine administered via injection, indicating that oral vaccination is a viable cost-effective alternative to administering vaccines by injection.
The Formation of 3-Monochloropropanediol Esters and Glycidyl Esters during Heat-Induced Processing Using an Olive-Based Edible Oil
Authors: Ji Yingrui , Lan Dongming , Wang Weifei , Goh Kok Ming , Tan Chin Ping , Wang Yonghua
Published: December 2022

With the prevalence of edible diacylglycerol (DAG) oil, which is beneficial to human, the generation of 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) as well as the stability of physical properties during heat-induced processing still need to be explored. In this study, the experiment used olive-based edible oil with different contents of DAG (40, 60, and 80%) to make crackers and fry chicken. They were heated at 160 and 180 °C to determine the changes in 3-MCPDE and GE, the crackers’ hardness and gumminess, and the physical properties of the oil. During baking and frying, 3-MCPDE decreased, while the content of GE slightly increased with the prolonged heating duration. Finally, 3-MCPDE and GE were lower than 1.25 mg/kg and 1.00 mg/kg, respectively. The AV increased proportionally as duration increased and POV was below 0.30 g/100 g. In general, the changes in 3-MCPDE and GE were related to the heating temperature and duration, and not significantly (p > 0.05) related to the content of DAG.
Potential Aroma Chemical Fingerprint of Oxidised Coffee Note by HS-SPME-GC-MS and Machine Learning
Authors: Strocchi Giulia , Bagnulo Eloisa , Ruosi Manuela R. , Ravaioli Giulia , Trapani Francesca , Bicchi Carlo , Pellegrino Gloria , Liberto Erica
Published: December 2022

This study examines the volatilome of good and oxidised coffee samples from two commercial coffee species (i.e., Coffea arabica (arabica) and Coffea canephora (robusta)) in different packagings (i.e., standard with aluminium barrier and Eco-caps) to define a fingerprint potentially describing their oxidised note, independently of origin and packaging. The study was carried out using HS-SPME-GC-MS/FPD in conjunction with a machine learning data processing. PCA and PLS-DA were used to extrapolate 25 volatiles (out of 147) indicative of oxidised coffees, and their behaviour was compared with literature data and critically discussed. An increase in four volatiles was observed in all oxidised samples tested, albeit to varying degrees depending on the blend and packaging: acetic and propionic acids (pungent, acidic, rancid), 1-H-pyrrole-2-carboxaldehyde (musty), and 5-(hydroxymethyl)-dihydro-2(3H)-furanone.
Effect of Moisture Content Difference on the Analysis of Quality Attributes of Red Pepper (Capsicum annuum L.) Powder Using a Hyperspectral System
Authors: Choi Ji-Young , Cho Jeong-Seok , Park Kee Jai , Choi Jeong Hee , Lim Jeong Ho
Published: December 2022

The variety of characteristics of red pepper makes it difficult to analyze at the production field through hyperspectral imaging. The importance of pretreatment to adjust the moisture content (MC) in the process of predicting the quality attributes of red pepper powder through hyperspectral imaging was investigated. Hyperspectral images of four types of red pepper powder with different pungency levels and MC were acquired in the visible near-infrared (VIS-NIR) and short-wave infrared (SWIR) regions. Principal component analysis revealed that the powders were grouped according to their pungency level, color value, and MC (VIS-NIR, Principal Component 1 = 95%; SWIR, Principal Component 1 = 91%). The loading plot indicated that 580–610, 675–760, 870–975, 1020–1130, and 1430–1520 nm are the key wavelengths affected by the presence of O-H and C-H bonds present in red pigments, capsaicinoids, and water molecules. The R2 of the partial least squares model for predicting capsaicinoid and free sugar in samples with a data MC difference of 0–2% was 0.9 or higher, and a difference of more than 2% in MC had a negative effect on prediction accuracy. The color value prediction accuracy was barely affected by the difference in MC. It was demonstrated that adjusting the MC is essential for capsaicinoid and free sugar analysis of red pepper.
The Potential of Food By-Products: Bioprocessing, Bioactive Compounds Extraction and Functional Ingredients Utilization
Authors: Verni Michela , Casanova Federico
Published: December 2022

Achieving sustainability in the agro-food sector can only be possible with the valorization of food industry waste and side streams, products with an extremely high intrinsic value but often discarded because they are unfit for further processing that meets consumer expectations [...]
Effect and Correlation of Rosa roxburghii Tratt Fruit Vinegar on Obesity, Dyslipidemia and Intestinal Microbiota Disorder in High-Fat Diet Mice
Authors: Li Jiuchang , Zhang Jun , Zhang Yulong , Shi Yuanyuan , Feng Dandan , Zuo Yunyang , Hu Ping
Published: December 2022

To investigate the effect of Rosa roxburghii Tratt fruit vinegar (RFV) on the intervention of obesity and hyperlipidemia and its potential mechanism, a high-fat diet (HFD)-induced obesity model in mice was established and gavaged with RFV, saline and xuezhikang for 30 consecutive days, respectively. The results showed that RFV supplementation significantly reduced fat accumulation, and improved dyslipidemia and liver inflammation in HFD mice. RFV intervention for 30 days significantly improved the diversity of gut microbiota and altered the structure of gut microbiota in HFD mice. Compared with the model group (MC), the ratio of Firmicutes to Bacteroidetes at least decreased by 15.75% after RFV treatment, and increased the relative abundance of beneficial bacteria (Proteobacteria, Bacteroidetes, Lactobacillaceae, Bacteroides, Akkermansia,) and decreased the relative abundance of harmful bacteria (Ruminococcaceae, Erysipelotrichaceae, Ruminococcaceae _UCG-013, Lachnospiraceae, Allobaculum, Actinobacteria). Spearman’s correlation analysis revealed that Erysipelotrichaceae, Allobaculum, Lachnospiraceae, Ruminococcaceae, Ruminococcaceae_UCG-013, uncultured_bacterium_f_Lachnospiraceae and Desulfobacterota were positively correlated (p < 0.05) with the body weight of mice, while Proteobacteria was negatively correlated (p < 0.05) with the body weight of mice. The two main bacteria that could promote dyslipidemia in obese mice were Actinobacteria and Firmicutes, while those that played a mitigating role were mainly Bacteroidetes. It is concluded that RFV plays an important role in the intervention of obesity and related complications in HFD mice by regulating their gut microbiota.
Insights into Characteristic Volatiles in Wuyi Rock Teas with Different Cultivars by Chemometrics and Gas Chromatography Olfactometry/Mass Spectrometry
Authors: Zhang Yue , Kang Suyoung , Yan Han , Xie Dongchao , Chen Qincao , Lv Haipeng , Lin Zhi , Zhu Yin
Published: December 2022

Wuyi rock tea (WRT) is one of the most famous subcategories of oolong tea, exhibiting distinct aroma characteristics with the application of different cultivars. However, a comprehensive comparison of the characteristic volatiles among WRTs with different cultivars has rarely been carried out. In this study, non-targeted analyses of volatile fragrant compounds (VFCs) and targeted aroma-active compounds in WRTs from four different cultivars were performed using chemometrics and gas chromatography olfactometry/mass spectrometry (GC-O/MS). A total of 166, 169, 166, and 169 VFCs were identified for Dahongpao (DHP), Rougui (RG), Shuixian (SX), and Jinfo (JF), respectively; and 40 components were considered as the key differential VFCs among WRTs by multivariate statistical analysis. Furthermore, 56 aroma-active compounds were recognized with predominant performances in “floral & fruity”, “green & fresh”, “roasted and caramel”, “sweet”, and “herbal” attributes. The comprehensive analysis of the chemometrics and GC-O/MS results indicated that methyl salicylate, p-cymene, 2,5-dimethylpyrazine, and 1-furfurylpyrrole in DHP; phenylethyl alcohol, phenethyl acetate, indole, and (E)-β-famesene in RG; linalool, phenethyl butyrate, hexyl hexanoate, and dihydroactinidiolide in JF; and naphthalene in SX were the characteristic volatiles for each type of WRT. The obtained results provide a fundamental basis for distinguishing tea cultivars, recombination, and simulation of the WRT aroma.
Dairy Products: A Potential Source of Multidrug-Resistant Enterococcus faecalis and Enterococcus faecium Strains
Authors: Gołaś-Prądzyńska Marlena , Łuszczyńska Magdalena , Rola Jolanta Grażyna
Published: December 2022

This study attempts to present the antimicrobial resistance, virulence and resistance genes of Enterococcus faecalis and Enterococcus faecium isolated from raw goat’s and sheep’s milk and cheese. Strains were identified by PCR. The dominant species was E. faecalis (77.8%) and was most often isolated from raw goat’s milk. The percentage of antimicrobial-resistant E. faecalis isolates was higher than that of E. faecium isolates, the former most frequently resistant to lincomycin (98%), tetracycline (63%) and streptomycin (16%). Fourteen (22.3%) E. faecalis and 2 (11.1%) E. faecium isolates were identified as multidrug-resistant (MDR). All MDR E. faecalis strains also had virulence genes, whereas one of the two E. faecium strains had them. The most prevalent virulence genes in E. faecalis isolates were asa1 (69.8%) and gelE (57.1%). The most prevalent resistance genes found in both bacterial species were tet(M) (43.2%) and vgaA (22.2%). Enterococci from dairy products are confirmed to be a potential source of the spread of antimicrobial resistance, MDR strains, and virulence and resistance genes. This study highlights several aspects of the virulence and pathogenicity of E. faecalis and E. faecium isolated from dairy products—aspects which are indications for their ongoing monitoring.
Wildlife Forensic Sciences: A Tool to Nature Conservation towards a One Health Approach
Authors: Jota Baptista Catarina , Seixas Fernanda , Gonzalo-Orden José Manuel , Oliveira Paula A.
Published: December 2022

Wildlife forensics is a science field with a remarkable potential to provide accurate information regarding nature conservation and One Health. Wildlife crimes are now a persistent target of public opinion and the concern of conservation professionals, which is constantly putting pressure on governmental and non-governmental entities. Moreover, the cross-species transmission of pathogens is becoming more and more frequent, endangering the interconnected health of humans, animals and the environment (One Health). This review intends to briefly present and illustrate the potential of wildlife forensic sciences not only in crime solving, but also regarding health sciences and species conservation. By allowing target species identification, recreating the crime scene, and considering their contribution to diseases and ecosystems’ surveillance, wildlife forensics are now constantly developing and improving. A cooperative and multidisciplinary approach (with the inclusion of forensic sciences) is necessary to avoid wildlife crimes, disease outbreaks, environmental disasters and to promote a sustainable and healthy future for all the living beings.
A Thermal-Responsive Zwitterionic Polymer Gel as a Filtrate Reducer for Water-Based Drilling Fluids
Authors: Lv Kaihe , Du Hongyan , Sun Jinsheng , Huang Xianbin , Shen Haokun
Published: December 2022

It is crucial to address the performance deterioration of water-based drilling fluids (WDFs) in situations of excessive salinity and high temperature while extracting deep oil and gas deposits. The focus of research in the area of drilling fluid has always been on filter reducers that are temperature and salt resistant. In this study, a copolymer gel (PAND) was synthesized using acrylamide, N-isopropyl acrylamide, and 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate through free-radical polymerization. The copolymer gel was then studied using FTIR, NMR, TGA, and element analysis. The PAND solution demonstrated temperature and salt stimulus response characteristics on rheology because of the hydrophobic association effect of temperature-sensitive monomers and the anti-polyelectrolyte action of zwitterionic monomers. Even in conditions with high temperatures (180 °C) and high salinities (30 wt% NaCl solution), the water-based drilling fluid with 1 wt% PAND displayed exceptional rheological and filtration properties. Zeta potential and scanning electron microscopy (SEM) were used to investigate the mechanism of filtration reduction. The results indicated that PAND could enhance bentonite particle colloidal stability, prevent bentonite particle aggregation, and form a compact mud cake, all of which are crucial for reducing the filtration volume of water-based drilling fluid. The PAND exhibit excellent potential for application in deep and ultra-deep drilling engineering, and this research may offer new thoughts on the use of zwitterionic polymer gel in the development of smart water-based drilling fluid.