bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemically Influenced Self-Preservation Kinetics of CH4 Hydrates below the Sub-Zero Temperature
Authors: Pandey Jyoti Shanker , Khan Saad , von Solms Nicolas
Published: October 2021

The self-preservation property of CH4 hydrates is beneficial for the transportation and storage of natural gas in the form of gas hydrates. Few studies have been conducted on the effects of chemicals (kinetic and thermodynamic promoters) on the self-preservation properties of CH4 hydrates, and most of the available literature is limited to pure water. The novelty of this work is that we have studied and compared the kinetics of CH4 hydrate formation in the presence of amino acids (hydrophobic and hydrophilic) when the temperature dropped below 0 °C. Furthermore, we also investigated the self-preservation of CH4 hydrate in the presence of amino acids. The main results are: (1) At T < 0 ℃, the formation kinetics and the total gas uptake improved in the presence of histidine (hydrophilic) at concentrations greater than 3000 ppm, but no significant change was observed for methionine (hydrophobic), confirming the improvement in the formation kinetics (for hydrophilic amino acids) due to increased subcooling; (2) At T = −2 °C, the presence of amino acids improved the metastability of CH4 hydrate. Increasing the concentration from 3000 to 20,000 ppm enhanced the metastability of CH4 hydrate; (3) Metastability was stronger in the presence of methionine compared to histidine; (4) This study provides experimental evidence for the use of amino acids as CH4 hydrate stabilizers for the storage and transportation of natural gas due to faster formation kinetics, no foam during dissociation, and stronger self-preservation.
Self-Correcting Virtual Current Sensor Based on the Modified Luenberger Observer for Fault-Tolerant Induction Motor Drive
Authors: Adamczyk Michal , Orlowska-Kowalska Teresa
Published: October 2021

Fault-tolerant control (FTC) solutions are increasingly being used in modern drive systems with AC motors. Such systems provide a higher degree of security and solutions that allow the on-line detection and localization of failures, as well as the switching of the control mode to a mode that allows us to continue the operation or safely stop the drive system. As the current sensors (CSs) are necessary to ensure precise control of the AC motors, in the event of their failure, one of two strategies can be used—hardware or software redundancy. The first strategy requires the use of additional measuring sensors. For this reason, the algorithmic solution, based on the Luenberger Observer (LO), has been proposed in this article as one of the software redundancy methods. In contrast to methods presented in the literature, the proposed solution allows one not only to compensate the stator current in a phase with a faulty CS, but also to adjust the correction of current estimation based on a measured signal in the other phase with a healthy CS. Extensive simulation studies in the direct rotor flux-oriented control (DRFOC) structure with the induction motor (IM) confirm the effectiveness of the proposed method. In addition, the proposed solution allows the drive system to be controlled even if all CSs are damaged.
Failure Analysis of Wind Turbine Planetary Gear
Authors: Bejger Artur , Frank Ewelina , Bartoszko Przemysław
Published: October 2021

The article presents selected problems related to an analysis of damage to wind turbine planetary gear. It is the most vital element installed in wind turbines, affecting the operational costs (prolonged downtime), and costs of repairs and servicing including delivery of required components. The authors have analyzed the wear/failure of planetary gear. The process initiating fatigue wear, different from similar devices in other industries, can be easily observed in wind turbine gear. This establishes a specific direction of research into the causes, and early detection of ‘gas spots’ on gear teeth as they seem to trigger fatigue wear.
Analysis of the Transformer Characteristics for an Integration System with a Wireless Power Transfer Device and Linear Motor
Authors: Woo Hwajin , Park Jang-Hyun , Joo Changdae , Ahn Hokyun , Kang Dohyun , Kim Taekue
Published: October 2021

This paper proposed the transformer characteristic analysis method for the wireless power transfer (WPT) device and linear motor (LM) integration system that can be applied to industrial cleanroom transfer systems. A cable is required to supply the power in conventional systems. In comparison, the proposed system utilizes a WPT device that can simplify power transfers and make a better space utilization. The shape of the wireless power transmission system is proposed along with the discussion of the 2D FEA analysis method about the inductance analyzing method, which are important parameters in magnetic coupling. In addition, ferrite iron loss was calculated based on the analysis results, and applied to the entire modeling circuit to verify the validity of the measured and analyzed values. Finally, the proposed analysis method for the transformer coupling characteristics of the wireless power transfer combined with the transfer system is verified by experiments and simulations.
DC-DC 3SSC-A-Based Boost Converter: Analysis, Design, and Experimental Validation
Authors: Souza Lucas Carvalho , Morais Douglas Carvalho , Silva Luciano de Souza da Costa e , Seixas Falcondes José Mendes de , Arenas Luis De Oro
Published: October 2021

A detailed analysis and validation of the DC-DC boost converter based on the three-state switching cell (3SSC) type-A are presented in this paper. The study of this topology is justified by the small amount of research that employs 3SSC-A and the advantages inherent to 3SSC-based converters, such as the division of current stresses between the semiconductors, the distribution of thermal losses, and the high-density power. Therefore, a complete static analysis of the converter is described, as well as the study of all voltage and current stresses in the semiconductors, the development of a loss model in all components, and a comparison with other step-up structures. Additionally, the small-signal model validation is accomplished by comparing the theoretical frequency response and the simulated AC sweep analysis. Finally, implementing a simple controller structure, the converter is experimentally validated through a 600 W prototype, where its overall efficiency is examined for various load conditions, reaching 96.8% at nominal load.
Empirical Research of Public Acceptance on Environmental Tax: A Systematic Literature Review
Authors: Muhammad Izlawanie , Mohd Hasnu Norfakhirah Nazihah , Ekins Paul
Published: October 2021

Several international organizations such as the Organization for Economic Co-operation and Development (OECD), United Nations (UN), and World Bank recommend that policymakers implement an environmental tax to reduce climate change, protect the environment and gain more income for governments. Effectiveness of the policy depends on a carefully designed framework, which essentially adopts the social and economic contextual of a country and public support. Researchers have been focusing on examining the factors that influence public acceptance of an environmental tax. This paper aims to systematically review the empirical studies using the RepOrting Standards for Systematic Evidence Syntheses (ROSES) protocol. The information is relevant for policy makers in designing a feasible and acceptable carbon tax policy. Furthermore, the paper provides suggestions for future research. Related articles were selected using two leading databases, namely Scopus and Science Direct, and one supporting database, namely Google Scholar. Thematic analysis was conducted on 60 articles and four main themes were derived with 32 subthemes. The analysis indicates that people are more supportive when they (i) are well informed about a policy’s effectiveness and the policy content, particularly the use of revenue, (ii) have high trust in the government, (iii) have a positive attitude toward protecting the environment, (iv) perceive the policy is fair in terms of costs distribution and social sharing, and (v) are concerned about the climate change issue.
Testing the Performance of Some Competition Indices against Experimental Data and Outputs of Spatially Explicit Simulation Models
Authors: Shanin Vladimir , Hökkä Hannu , Grabarnik Pavel
Published: October 2021

Three competition indices were tested against experimental data on the growth of individual trees in mapped forest stands and outputs of spatially explicit, process-based models of competition. The comparison showed the fundamental importance of taking into account the spatial structure of stands and, particularly, the relative spatial locations of individual trees (spatial asymmetry) when calculating the competition between trees. Although none of the competition indices are able to take into account the specific processes affecting the development of individual trees, these indices can be used in forest dynamics modeling as a simplified representation of competition between trees for resources.
Increase in Fruity Ester Production during Spine Grape Wine Fermentation by Goal-Directed Amino Acid Supplementation
Authors: Zhu Zijian , Hu Kai , Chen Siyu , Xiong Sirui , Tao Yongsheng
Published: October 2021

The aim of this work was to enhance the levels of fruity esters in spine grape (Vitis davidii Foёx) wine by goal-directed amino acid supplementation during fermentation. HPLC and GC-MS monitored the amino acids and fruity esters, respectively, during alcoholic fermentation of spine grape and Cabernet Sauvignon grape. HPLC was also used to determine the extracellular metabolites and precursors involved in the synthesis of fruity esters. Alanine, phenylalanine, and isoleucine levels in spine grape were less than those in Cabernet Sauvignon. Pearson correlation between amino acid profile and fruity ester content in the two systems indicated that deficiencies in alanine, phenylalanine, and isoleucine levels might have limited fruity ester production in spine grape wine. Supplementation of these three amino acids based on their levels in Cabernet Sauvignon significantly increased fruity ester content in spine grape wine. Interestingly, goal-directed amino acid supplementation might have led to changes in the distribution of carbon fluxes, which contributed to the increase in fruity ester production.
Nonlinear Analysis of a Steel Frame Structure Exposed to Post-Earthquake Fire
Authors: Alisawi Alaa T. , Collins Philip E. F. , Cashell Katherine A.
Published: October 2021

The probability of extreme events such as an earthquake, fire or blast occurring during the lifetime of a structure is relatively low but these events can cause serious damage to the structure as well as to human life. Due to the significant consequences for occupant and structural safety, an accurate analysis of the response of structures exposed to these events is required for their design. Some extreme events may occur as a consequence of another hazard, for example, a fire may occur due to the failure of the electrical system of a structure following an earthquake. In such circumstances, the structure is subjected to a multi-hazard loading scenario. A post-earthquake fire (PEF) is one of the major multi-hazard events that is reasonably likely to occur but has been the subject of relatively little research in the available literature. In most international design codes, structures exposed to multi-hazards scenarios such as earthquakes, which are then followed by fires are only analysed and designed for as separate events, even though structures subjected to an earthquake may experience partial damage resulting in a more severe response to a subsequent fire. Most available analysis procedures and design codes do not address the association of the two hazards. Thus, the design of structures based on existing standards may contribute to a significant risk of structural failure. Indeed, a suitable method of analysis is required to investigate the behaviour of structures when exposed to sequential hazards. In this paper, a multi-hazard analysis approach is developed, which considers the damage caused to structures during and after an earthquake through a subsequent thermal analysis. A methodology is developed and employed to study the nonlinear behaviour of a steel framed structure under post-earthquake fire conditions. A three-dimensional nonlinear finite element model of an unprotected steel frame is developed and outlined.
Improvement in Lactose Tolerance in Hypolactasic Subjects Consuming Ice Creams with High or Low Concentrations of Bifidobacterium bifidum 900791
Authors: Aguilera Gabriela , Cárcamo Constanza , Soto-Alarcón Sandra , Gotteland Martin
Published: October 2021

Although Bifidobacterium bifidum expresses lactase activity, no clinical trials have determined its impact on lactose-intolerant subjects. This study evaluated whether acute and chronic ingestion of ice creams containing B. bifidum 900791 at high (107 CFU/g) or low (105 CFU/g) concentrations improved lactose tolerance in hypolactasic subjects. Fifty subjects were selected based on a positive lactose (20 g) hydrogen breath test (HBT0) and the presence of digestive symptoms. The recruited subjects were required to perform breath tests after the acute ingestion of: (1) ice cream containing 20 g of lactose without a probiotic (HBT1); (2) the same ice cream, accompanied by a lactase tablet (HBT2); (3) the same ice cream containing the low or high dose of probiotic (HBT3-LD and HBT3-HD); and (4) after the chronic consumption of the ice cream without (placebo) or with the low concentration of probiotic for 1 month (HBT4). Significant decreases in H2 excretion during HBT2 and HBT3-HD as well as digestive symptoms during HBT2, HBT3-HD and HBT3-LD were observed compared to HBT0 and HBT1, while the orocecal transit time increased. Chronic consumption of the probiotic ice cream did not enhance lactose tolerance compared to the placebo. These results suggest that the acute ingestion of ice cream containing high or low concentrations of B. bifidum 900791 improves lactose tolerance in hypolactasic subjects.
Polyphenolic Antibacterials for Food Preservation: Review, Challenges, and Current Applications
Authors: Martinengo Peter , Arunachalam Kannappan , Shi Chunlei
Published: October 2021

Natural alternatives replacing artificial additives have gained much attention in the consumer’s view because of the growing search for clean label products that are devoid of carcinogenic and toxic effects. Plant polyphenols are considered as suitable alternative natural preservatives with antioxidant and antimicrobial properties. However, their uses in the food industry are undermined by a series of limitations such as low solubility and stability during food processing and storage, lack of standardization, and undesirable organoleptic properties. Different approaches in the use of polyphenols have been proposed in order to overcome the current hurdles related to food preservation. This review article specifically focuses on the antibacterial activity of plant-derived polyphenols as well as their applications as food preservatives, main challenges, and other trends in the food industry.
Volatile Compounds in Monovarietal Wines of Two Amarone Della Valpolicella Terroirs: Chemical and Sensory Impact of Grape Variety and Origin, Yeast Strain and Spontaneous Fermentation
Authors: Luzzini Giovanni , Slaghenaufi Davide , Ugliano Maurizio
Published: October 2021

Aroma profiles of withered Corvina and Corvinone wines from two different Valpolicella terroirs were investigated in relationship to yeast strain and use of spontaneous fermentation. The results indicated that volatile chemical differences between wines were mainly driven by grape origin, which was associated with distinctive compositional profiles. Wine content in terpenes, norisoprenoids, benzenoids and C6 alcohols, as well as some fermentative esters, were indeed significantly affected by grape origin. Conversely, yeast strain influence was mainly associated with fermentation-derived esters. Sensory analysis, besides confirming the major role of grape origin as driver of wine differentiation, indicated that spontaneous fermentations reduced the sensory differences associated with grape origin and variety, mainly due to high content of acetic acid and ethyl acetate.
Metabolite–Flavor Profile, Phenolic Content, and Antioxidant Activity Changes in Sacha Inchi (Plukenetia volubilis L.) Seeds during Germination
Authors: Keawkim Kannika , Lorjaroenphon Yaowapa , Vangnai Kanithaporn , Jom Kriskamol Na
Published: October 2021

Sacha inchi seeds are abundant in nutrients such as linolenic acids and amino acids. Germination can further enhance their nutritional and medicinal value; however, germination time is positively correlated with off-flavor in germinated seeds. This study investigated the changes in the metabolite and flavor profiles and evaluated the nutritional quality of sacha inchi seeds 8 days after germination (DAG). We also determined their phenolic content and antioxidant activity. We used gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography–mass spectrometry (GC-MS) and identified 63 metabolites, including 18 fatty acid methyl esters (FAMEs). FAMEs had the highest concentration in ungerminated seeds, especially palmitic, stearic, linoleic, linolenic, and oleic acids. Amino acids, total phenolic compounds (TPCs), and antioxidant activity associated with health benefits increased with germination time. At the final germination stage, oxidation products were observed, which are associated with green, beany, and grassy odors and rancid and off-flavors. Germination is a valuable processing step to enhance the nutritional quality of sacha inchi seeds. These 6DAG or 8DAG seeds may be an alternative source of high-value-added compounds used in plant-protein-based products and isolated protein.
Nutritional Quality of the European Spiny Lobster Palinurus elephas (J.C. Fabricius, 1787) (Achelata, Palinuridae) and the Non-Indigenous Northern Brown Shrimp Penaeus aztecus Ives, 1891 (Dendrobranchiata, Penaeidae)
Authors: Kampouris Thodoros E. , Asimaki Adamantia , Klaoudatos Dimitris , Exadactylos Athanasios , Karapanagiotidis Ioannis T. , Batjakas Ioannis E.
Published: October 2021

The European spiny lobster is a species of great commercial value, yet a limited scientific knowledge exists on its biology, ecology, and physiology, especially for the stocks from east Mediterranean waters. The northern brown shrimp, a non-indigenous established species, is commercially exploited in regions of the Mediterranean Sea. Both species’ proximate composition and fatty acid profile were assessed for the first time in the Mediterranean region, exhibiting an overall significant statistical difference. Protein, fat, and energy contents were significantly higher in the northern brown shrimp, whereas moisture and ash contents were significantly higher in the European spiny lobster. The proximate composition for both species was well within the reported range for other lobster and prawn species in the Mediterranean Sea.
Comparative 1H NMR-Based Chemometric Evaluations of the Time-Dependent Generation of Aldehydic Lipid Oxidation Products in Culinary Oils Exposed to Laboratory-Simulated Shallow Frying Episodes: Differential Patterns Observed for Omega-3 Fatty Acid-Containing Soybean Oils
Authors: Wann Angela I. , Percival Benita C. , Woodason Katy , Gibson Miles , Vincent Siâny , Grootveld Martin
Published: October 2021

Soybean oil is the second most exported oil from the United States and South America, and is widely marketed as a cooking oil product containing numerous health benefits for human consumers. However, culinary oils with high polyunsaturated fatty acid (PUFA) contents, are known to produce high quantities of lipid oxidation products (LOPs), including toxic aldehydes upon exposure to high-temperature frying episodes. Previous studies have demonstrated causal links between aldehyde ingestion and inhalation with deleterious health perturbations, including mutagenic and carcinogenic effects, along with cardiovascular and teratogenic actions. In this study, aldehydic LOPs were detected and quantified in commercially available samples of soybean, avocado, corn and extra-virgin olive oil products before and after their exposure to laboratory-simulated laboratory frying episodes (LSSFEs) using high-resolution 1H nuclear magnetic resonance (NMR) analysis. Results acquired demonstrated that PUFA-rich soybean and corn oils gave rise to the highest concentrations of oil aldehydes from the thermo-oxidation of unsaturated fatty acids, whereas monounsaturated fatty acid (MUFA)-laden avocado and olive oils were much more resistant to this peroxidation process, as expected. Multivariate chemometrics analyses provided evidence that an orthogonal component pattern of aldehydic LOPs featuring low-molecular-mass n-alkanals such as propanal, and 4-oxo-alkanals, arises from thermo-oxidation of the ω-3 fatty acid (FA) linolenic acid (present in soybean oils at levels of ca. 7% (w/w)), was able to at least partially distinguish this oil from corresponding samples of thermally-stressed corn oil. Despite having a similar total PUFA level, corn oil has only a negligible ω-3 FA content, and therefore generated significantly lower levels of these two aldehyde classes. In view of the adverse health effects associated with dietary LOP ingestion, alternative methodologies for the incorporation of soybean oils within high-temperature frying practices are proposed.
‘Don’t Worry, Honey: It’s Cooked’: Addressing Food Risk during Pregnancy on Facebook Italian Posts
Authors: Rizzoli Valentina , Mascarello Giulia , Pinto Anna , Crovato Stefania , Ruzza Mirko , Tiozzo Barbara , Ravarotto Licia
Published: October 2021

During pregnancy, women exposed to microbiological risks are more susceptible to contracting specific pathogens, which can lead to serious diseases both in the mother and the foetus. Food-borne diseases can be avoided to a large extent by following good practices of food manipulation and cooking. Safe eating behaviours are influenced by knowledge and perception of food risks and are constructed, among others, online. Pregnant women often use Web 2.0 to obtain and share pregnancy-related information as a strategy of collective coping with emotions through conversations. This paper explores how knowledge and perceptions of food risks during pregnancy are shared among users on Italian Facebook pages and groups. The corpus, including 648,399 items (i.e., posts), was analysed: (a) first, by means of the Reinert method, to verify to what extent issues concerning food risks are debated; and (b) second, through a manual content analysis, to observe how food risks are addressed in terms of contents and social sharing of emotions. The main results show that food risk is not among the most discussed topics, and the least known and debated food risks are the most widespread (e.g., campylobacteriosis). Sometimes, food risks, when addressed, were minimised or denied, and the belief to be ‘less at risk’ than peers for such risk (i.e., optimistic bias) was observed. The results underline the importance, for health institutions, of building a tailored communication strategy on food risks during pregnancy to promote correct food behaviours by exploiting social networks.
Changes of High-Purity Insoluble Fiber from Soybean Dregs (Okara) after Being Fermented by Colonic Flora and Its Adsorption Capacity
Authors: Lyu Bo , Wang Yi , Zhang Xin , Chen Yuxi , Fu Hongling , Liu Tong , Hao Jianyu , Li Yang , Yu Hansong , Jiang Lianzhou
Published: October 2021

In order to explore the changes and properties of high-purity insoluble dietary fiber from okara (HPIDF) after entering the colon and be fermented by colonic flora, fermented high-purity insoluble dietary fiber (F-HPIDF) was obtained by simulated fermentation in vitro by HPIDF and colonic flora from C57BL/6 mice. For exploring the differences of HPIDF and F-HPIDF, the changes of structure (SEM. FTIR, XRD, particle size, specific surface area, monosaccharide composition) and adsorption properties (water, oil, heavy metal irons, harmful substances) of HPIDF/F-HPIDF were explored. The results showed that F-HPIDF had a higher water-holding capacity (19.17 g/g), water-swelling capacity (24.83 mL/g), heavy metals-adsorption capacity (Cd2+: 1.82 μmol/g; Pb2+: 1.91 μmol/g; Zn2+: 1.30 μmol/g; Cu2+: 0.68 μmol/g), and harmful substances-adsorption capacity (GAC: 0.23 g/g; CAC: 14.80 mg/g; SCAC: 0.49 g/g) than HPIDF due to the changes of structure caused by fermentation. In addition, with the fermentation of HPIDF, some beneficial substances were produced, which might be potential intestinal prebiotics. The study of F-HPIDF strengthens the speculation that HPIDF may have potential bioactivities after entering the colon, which proved that okara-HPIDF may have potential functionality.
Unifloral Autumn Heather Honey from Indigenous Greek Erica manipuliflora Salisb.: SPME/GC-MS Characterization of the Volatile Fraction and Optimization of the Isolation Parameters
Authors: Xagoraris Marinos , Chrysoulaki Foteini , Revelou Panagiota-Kyriaki , Alissandrakis Eleftherios , Tarantilis Petros A. , Pappas Christos S.
Published: October 2021

For long heather honey has been a special variety due to its unique organoleptic characteristics. This study aimed to characterize and optimize the isolation of the dominant volatile fraction of Greek autumn heather honey using solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The described approach pointed out 13 main volatile components more closely related to honey botanical origin, in terms of occurrence and relative abundance. These volatiles include phenolic compounds and norisoprenoids, with benzaldehyde, safranal and p-anisaldehyde present in higher amounts, while ethyl 4-methoxybenzoate is reported for the first time in honey. Then, an experimental design was developed based on five numeric factors and one categorical factor and evaluated the optimum conditions (temperature: 60 °C, equilibration time: 30 min extraction time: 15 min magnetic stirrer velocity: 100 rpm sample volume: 6 mL water: honey ratio: 1:3 (v/w)). Additionally, a validation test set reinforces the above methodology investigation. Honey is very complex and variable with respect to its volatile components given the high diversity of the floral source. As a result, customizing the isolation parameters for each honey is a good approach for streamlining the isolation volatile compounds. This study could provide a good basis for future recognition of monofloral autumn heather honey.
The Role of Forensic Anthropology in the Medico-Legal Investigation of Remains Recovered at Sea: Analysis of a Case
Authors: Leggio Alessia , Tarzia Pietro , Introna Francesco
Published: October 2021

Forensic anthropological investigations often encounter cases that are difficult to interpret, especially when dealing with skeletal remains found in a marine context. Determining the immersion time in the sea of skeletal remains is a challenge for forensic investigations and answering this would solve many cases in the shortest time possible. The physical and chemical properties of bones change during their time in water and these changes cause difficulties and delays in identifying and reconstructing the biological profile of an unknown subject. In this paper, two forensic cases found at sea were analysed, the case of a disarticulated and extensively skeletonised corpse found on the coast of Reggio Calabria (Italy) and the case of an isolated foot, intact of soft tissues, found only 9 km away, on the coast of Vibo Valentia (Italy). The resolution hypothesis of the two cases was based on three search options because the disappearance of three known individuals was being investigated simultaneously. The investigations were conducted through a multidisciplinary work applying different analyses, including anthropometric, radiological, digital and, finally, genetic analyses. The results made it possible to determine the reconstruction of two biological profiles, both of Case A, the skeletal remain, and Case B, the subject to whom the foot belonged. The almost compatible anthropometric results of the two biological profiles, the presence of two very indicative partial tattoos and a genetic correlation led to the solution of a single court case.
Mechanically Strong, Low Thermal Conductivity and Improved Thermal Stability Polyvinyl Alcohol–Graphene–Nanocellulose Aerogel
Authors: Wang Xiuya , Xie Pengbo , Wan Ke , Miao Yuanyuan , Liu Zhenbo , Li Xiaojun , Wang Chenxi
Published: October 2021

Porous aerogel materials have advantages of a low density, low thermal conductivity and high porosity, and they have broad application prospects in heat insulation and building energy conservation. However, aerogel materials usually exhibit poor mechanical properties. Single-component aerogels are less likely to possess a good thermal stability and mechanical properties. It is necessary to prepare multiple-composite aerogels by reinforcement to meet practical application needs. In this experiment, a simple preparation method for polyvinyl alcohol (PVA)–graphene (GA)–nanocellulose (CNF) ternary composite aerogels was proposed. This is also the first time to prepare ternary composite aerogels by mixing graphene, nanocellulose and polyvinyl alcohol. A GA–CNF hydrogel was prepared by a one-step hydrothermal method, and soaked in PVA solution for 48 h to obtain a PVA–GA–CNF hydrogel. PVA–GA–CNF aerogels were prepared by freeze drying. The ternary composite aerogel has advantages of excellent mechanical properties, a low thermal conductivity and an improved thermal stability, because strong hydrogen bonds form between the PVA, GA and CNF. The composite aerogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, Brunauer–Emmett–Teller analysis, dynamic thermal analysis, thermogravimetry and thermal constant analysis to characterize the properties of the ternary composite aerogels. The lightweight, low-density and porous PVA–GA–CNF composite aerogels withstood 628 times their mass. The thermal conductivity of the composite aerogels was 0.044 ± 0.005 W/mK at room temperature and 0.045 ± 0.005 W/mK at 70 °C. This solid, low thermal conductivity and good thermal stability PVA–GA–CNF ternary composite aerogel has potential application in thermal insulation.
Matured Myofibers in Bioprinted Constructs with In Vivo Vascularization and Innervation
Authors: Ngan Catherine G. Y. , Quigley Anita , Williams Richard J. , O’Connell Cathal D. , Blanchard Romane , Boyd-Moss Mitchell , Aumann Tim D. , McKelvie Penny , Wallace Gordon G. , Choong Peter F. M. , Kapsa Rob M. I.
Published: October 2021

For decades, the study of tissue-engineered skeletal muscle has been driven by a clinical need to treat neuromuscular diseases and volumetric muscle loss. The in vitro fabrication of muscle offers the opportunity to test drug-and cell-based therapies, to study disease processes, and to perhaps, one day, serve as a muscle graft for reconstructive surgery. This study developed a biofabrication technique to engineer muscle for research and clinical applications. A bioprinting protocol was established to deliver primary mouse myoblasts in a gelatin methacryloyl (GelMA) bioink, which was implanted in an in vivo chamber in a nude rat model. For the first time, this work demonstrated the phenomenon of myoblast migration through the bioprinted GelMA scaffold with cells spontaneously forming fibers on the surface of the material. This enabled advanced maturation and facilitated the connection between incoming vessels and nerve axons in vivo without the hindrance of a scaffold material. Immunohistochemistry revealed the hallmarks of tissue maturity with sarcomeric striations and peripherally placed nuclei in the organized bundles of muscle fibers. Such engineered muscle autografts could, with further structural development, eventually be used for surgical reconstructive purposes while the methodology presented here specifically has wide applications for in vitro and in vivo neuromuscular function and disease modelling.
Prenatal Diagnosis of Combined Maternal 4q Interstitial Deletion and Paternal 15q Microduplication
Authors: Libotte Francesco , Fabiani Marco , Margiotti Katia , Viola Antonella , Mesoraca Alvaro , Giorlandino Claudio
Published: October 2021

The 4q deletion syndrome is a well-known rare genetic condition caused by partial, terminal, or interstitial deletion in the long arm (q) of chromosome 4. The phenotype of this syndrome shows a broad spectrum of clinical manifestations due to the great variability in the size and location of the deletion. In the literature, the mostly terminal deletions of chromosome 4q and the relative phenotypes are described, while the interstitial deletions of the long arm of chromosome 4 are rarely cited. Here, we report on a female fetus presenting no abnormal ultrasound evidence but with multiple chromosome aberrations. Comparative genomic hybridization (aCGH) revealed an interstitial 10.09 Mb deletion at the chromosome at the region of 4q28, arr[hg19] 4q28.1q28.3 (124068262_134158728)x1 combined with a 386.81 Kb microduplication at chromosome 15q11.1, arr[hg19] 15.11 (20249932_20636742)x3. At birth, and after 11 months, the baby was confirmed healthy and normal. The identification of this case allows for a deeper understanding of 4q syndrome and provides an explanation for the wide genetic/phenotypic spectrum of this pathology. This report can provide a reference for prenatal diagnosis and genetic counseling in patients who have similar cytogenetic abnormalities, and underlines the importance of reporting unusual variant chromosomes for diagnostic genetic purposes.
Lineage-Specific Genes and Family Expansions in Dictyostelid Genomes Display Expression Bias and Evolutionary Diversification during Development
Authors: Luna Saara K. , Chain Frédéric J. J.
Published: October 2021

Gene duplications generate new genes that can contribute to expression changes and the evolution of new functions. Genomes often consist of gene families that undergo expansions, some of which occur in specific lineages that reflect recent adaptive diversification. In this study, lineage-specific genes and gene family expansions were studied across five dictyostelid species to determine when and how they are expressed during multicellular development. Lineage-specific genes were found to be enriched among genes with biased expression (predominant expression in one developmental stage) in each species and at most developmental time points, suggesting independent functional innovations of new genes throughout the phylogeny. Biased duplicate genes had greater expression divergence than their orthologs and paralogs, consistent with subfunctionalization or neofunctionalization. Lineage-specific expansions in particular had biased genes with both molecular signals of positive selection and high expression, suggesting adaptive genetic and transcriptional diversification following duplication. Our results present insights into the potential contributions of lineage-specific genes and families in generating species-specific phenotypes during multicellular development in dictyostelids.
Marek’s Disease Virus Telomeric Integration Profiles of Neoplastic Host Tissues Reveal Unbiased Chromosomal Selection and Loss of Cellular Diversity during Tumorigenesis
Authors: Glass Marla C. , Smith Justin M. , Cheng Hans H. , Delany Mary E.
Published: October 2021

The avian α-herpesvirus known as Marek’s disease virus (MDV) linearly integrates its genomic DNA into host telomeres during infection. The resulting disease, Marek’s disease (MD), is characterized by virally-induced lymphomas with high mortality. The temporal dynamics of MDV-positive (MDV+) transformed cells and expansion of MD lymphomas remain targets for further understanding. It also remains to be determined whether specific host chromosomal sites of MDV telomere integration confer an advantage to MDV-transformed cells during tumorigenesis. We applied MDV-specific fluorescence in situ hybridization (MDV FISH) to investigate virus-host cytogenomic interactions within and among a total of 37 gonad lymphomas and neoplastic splenic samples in birds infected with virulent MDV. We also determined single-cell, chromosome-specific MDV integration profiles within and among transformed tissue samples, including multiple samples from the same bird. Most mitotically-dividing cells within neoplastic samples had the cytogenomic phenotype of ‘MDV telomere-integrated only’, and tissue-specific, temporal changes in phenotype frequencies were detected. Transformed cell populations composing gonad lymphomas exhibited significantly lower diversity, in terms of heterogeneity of MDV integration profiles, at the latest stages of tumorigenesis (>50 days post-infection (dpi)). We further report high interindividual and lower intraindividual variation in MDV integration profiles of lymphoma cells. There was no evidence of integration hotspots into a specific host chromosome(s). Collectively, our data suggests that very few transformed MDV+ T cell populations present earlier in MDV-induced lymphomas (32–50 dpi), survive, and expand to become the dominant clonal population in more advanced MD lymphomas (51–62 dpi) and establish metastatic lymphomas.
Mechanisms of Genome Instability in the Fragile X-Related Disorders
Authors: Hayward Bruce E. , Usdin Karen
Published: October 2021

The Fragile X-related disorders (FXDs), which include the intellectual disability fragile X syndrome (FXS), are disorders caused by expansion of a CGG-repeat tract in the 5′ UTR of the X-linked FMR1 gene. These disorders are named for FRAXA, the folate-sensitive fragile site that localizes with the CGG-repeat in individuals with FXS. Two pathological FMR1 allele size classes are distinguished. Premutation (PM) alleles have 54–200 repeats and confer the risk of fragile X-associated tremor/ataxia syndrome (FXTAS) and fragile X-associated primary ovarian insufficiency (FXPOI). PM alleles are prone to both somatic and germline expansion, with female PM carriers being at risk of having a child with >200+ repeats. Inheritance of such full mutation (FM) alleles causes FXS. Contractions of PM and FM alleles can also occur. As a result, many carriers are mosaic for different sized alleles, with the clinical presentation depending on the proportions of these alleles in affected tissues. Furthermore, it has become apparent that the chromosomal fragility of FXS individuals reflects an underlying problem that can lead to chromosomal numerical and structural abnormalities. Thus, large numbers of CGG-repeats in the FMR1 gene predisposes individuals to multiple forms of genome instability. This review will discuss our current understanding of these processes.
The Utility of Sentinel-2 MSI Data to Estimate Wetland Vegetation Leaf Area Index in Natural and Rehabilitated Wetlands
Authors: Tshabalala Nonjabulo Neliswa , Mutanga Onisimo , Sibanda Mbulisi
Published: October 2021

Wetland ecosystems are being modified and threatened due to anthropogenic activities and climate change, hence the urgent need for wetland restoration. Wetland rehabilitation is important in the reversal of these dire conditions, and this can be pursued through restoring damaged wetland ecosystems and recovering wetland vegetation. Wetland biophysical properties such as leaf area index (LAI) are important indicators of vegetation productivity and stress. Therefore, the study sought to test the potential of Sentinel-2 multispectral instrument (MSI) derived standard bands, traditional vegetation indices and red-edge derived vegetation indices in estimating wetland vegetation LAI across natural and rehabilitated wetlands. Traditional field surveys were carried out for LAI measurement of wetland vegetation using the LAI-2200 Plant Canopy Analyser. Partial Least Squares Regression (PLSR) algorithms were used to compare the estimation strength of models derived from all Sentinel-2 MSI bands, conventional vegetation indices and red-edge derived vegetation indices. Leave-one-out cross-validation (LOOCV) was completed on a selected measured dataset to evaluate the performance and accuracy of the estimation models. The optimal models for estimating wetland vegetation LAI were produced based on red-edge bands centred between the 705–783 nm as well as the 865 nm (Band 8a) of the electromagnetic spectrum. The results showed that vegetation indices derived from red-edge bands performed better at estimating LAI for both wetlands with a root mean square error of prediction (RMSE) of 0.32 m2/m2 and R2 of 0.61 for the natural wetland, and RMSE of 0.51 m2/m2 and R2 of 0.75 for the rehabilitated wetland. The optimal model for predicting LAI across natural and rehabilitated wetlands was attained based on red-edge bands centred at 705 nm (Band 5), 740 nm (Band 6), 783 nm (Band 7) as well as 865 nm (Band 8a) yielding a RMSE of 0.51 m2/m2 and R2 of 0.54. Overall, the results underscore the importance of remotely sensed derived data and vegetation indices in the optimal characterisation of wetland vegetation productivity which can be utilized in the monitoring and management of wetland ecosystems.
The Silent Forest: Impact of Bird Hunting by Prehistoric Polynesians on the Decline and Disappearance of Native Avifauna in Hawai’i
Authors: Pérez Francisco L.
Published: October 2021

This research focuses on the historical demise of Hawaiian avifauna due to hunting by ancient Polynesians. Numerous documents, published since the early 1800s, were scrutinized and evaluated; these provided information on bird hunting and traditional Hawaiian practices. Hawaiians used birds as sources of feathers and food. Feathers were important symbols of power for Polynesians; in Hawai’i, feathers were more highly prized than other types of property. Feathers used for crafts were obtained from at least 24 bird species, however, the golden feathers of ‘ō‘ō and mamo birds made them primary targets for birdhunters; both birds became extinct by the late 1800s. Feathers were utilized for many items, including ‘ahu‘ula [cloaks], mahiole [war helmets], and kāhili [standards]. Most garments utilized a considerable number of feathers; a cloak for Kamehameha consumed the golden feathers of 80,000 mamo birds. Bird meat was an important food item for native Hawaiians. It is believed that most birds were killed after being plucked; historical sources mention ~30 bird species were consumed. The ‘ua‘u (Pterodroma sandwichensis), a currently endangered seabird, was ruthlessly hunted and avidly eaten. Its current geographical range is just a minute fraction of its former one; now, ‘ua‘us are largely restricted to inaccessible cliffs at Haleakalā Crater (Maui).
Short-Term Meteorological and Environmental Signals Recorded in a Firn Core from a High-Accumulation Site on Plateau Laclavere, Antarctic Peninsula
Authors: Hoffmann-Abdi Kirstin , Fernandoy Francisco , Meyer Hanno , Freitag Johannes , Opel Thomas , McConnell Joseph , Schneider Christoph
Published: October 2021

High-accumulation sites are crucial for understanding the patterns and mechanisms of climate and environmental change in Antarctica since they allow gaining high-resolution proxy records from firn and ice. Here, we present new glacio- and isotope-geochemical data at sub-annual resolution from a firn core retrieved from an ice cap on Plateau Laclavere (LCL), northern Antarctic Peninsula, covering the period 2012–2015. The signals of two volcanic eruptions and two forest fire events in South America could be identified in the non-sea-salt sulphur and black carbon records, respectively. Mean annual snow accumulation on LCL amounts to 2500 kg m−2 a−1 and exhibits low inter-annual variability. Time series of δ18O, δD and d excess show no seasonal cyclicity, which may result from (1) a reduced annual temperature amplitude due to the maritime climate and (2) post-depositional processes. The firn core stratigraphy indicates strong surface melt on LCL during austral summers 2013 and 2015, likely related to large-scale warm-air advection from lower latitudes and temporal variations in sea ice extent in the Bellingshausen-Amundsen Sea. The LCL ice cap is a highly valuable natural archive since it captures regional meteorological and environmental signals as well as their connection to the South American continent.
The Prevalence and Determinant of PTSD Symptoms among Home-Quarantined Chinese University Students during the COVID-19 Pandemic
Authors: Zhang Yueyang , Zhao Jingjing , Xi Juzhe , Fan Bingbing , Wang Qiong , Yao Zhiying , Huang Tianhui , Bai Han
Published: October 2021

Background: When COVID-19 emerged in China in late 2019, most Chinese university students were home-quarantined to prevent the spread of the virus, considering the great impact of the lockdown on young people habits and their psychological well-being. This study explored the prevalence of post-traumatic stress disorder (PTSD) and its associated factors among Chinese university students who are isolated at home during the COVID-19 pandemic. Method: 4520 participants from five universities in China were surveyed by online questionnaire and the PTSD Checklist—Civilian Version (PCL-C) was adopted as a screening instrument. Results: Exposure to virus was significantly related to PTSD outcomes. The most important predictors for PTSD outcomes were parents’ relationship and the way parents educated, and university-provided psychological counseling was a protective factor against developing PTSD. Conclusions: The COVID-19 pandemic had adverse psychological consequences on Chinese university students who were isolated at home due to the relatively high prevalence rate of PTSD which was reported. Adverse parental relationships and the extreme way parents educate their children could be the major risk factors for PTSD outcomes. Psychological interventions need to be made available to home-quarantined university students, and those in the worst-hit and exposed areas to virus should be given priority focus.
The Effect of Using Participatory Working Time Scheduling Software on Employee Well-Being and Workability: A Cohort Study Analysed as a Pseudo-Experiment
Authors: Shiri Rahman , Karhula Kati , Turunen Jarno , Koskinen Aki , Ropponen Annina , Ervasti Jenni , Kivimäki Mika , Härmä Mikko
Published: October 2021

Shift workers are at increased risk of health problems. Effective preventive measures are needed to reduce the unfavourable effects of shift work. In this study we explored whether use of digital participatory working time scheduling software improves employee well-being and perceived workability by analysing an observational cohort study as a pseudo-experiment. Participants of the Finnish Public Sector cohort study with payroll records available between 2015 and 2019 were included (N = 2427). After estimating the propensity score of using the participatory working time scheduling software on the baseline characteristics using multilevel mixed-effects logistic regression and assigning inverse probability of treatment weights for each participant, we used generalised linear model to estimate the effect of using the participatory working time scheduling software on employees’ control over scheduling of shifts, perceived workability, self-rated health, work-life conflict, psychological distress and short sleep (≤6 h). During a 2-year follow-up, using the participatory working time scheduling software reduced the risk of employees’ low control over scheduling of shifts (risk ratio [RR] 0.34; 95% CI 0.25–0.46), short sleep (RR 0.70; 95% CI 0.52–0.95) and poor workability (RR 0.74; 95% CI 0.55–0.99). The use of the software was not associated with changes in psychological distress, self-rated health and work-life conflict. In this observational study, we analysed as a pseudo-experiment, the use of participatory working time scheduling software was associated with increased employees’ perceived control over scheduling of shifts and improved sleep and self-rated workability.