bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Altitude in Formation of Diatom Diversity of High Mountain Protected Glacier Lakes in the Kaçkar Mountains National Park, Rize, Turkey
Authors: Şahin Bülent , Barınova Sophia
Published: October 2022

The benthic diatom assemblages of the glacier Avusor Great Lake and Koçdüzü Great Lake were investigated in August 2019. A total of 71 diatom species belonging to 34 genera were determined in the samples, 49 species from Avusor Great Lake and 37 from Koçdüzü Great Lake. Only 15 diatom species were common to both lakes. Total floristic similarity between the neighbouring lakes was only 21.12%. Genera with the highest number of species were Eunotia (8), Gomphonema (6), Pinnularia (6), Navicula (5) and Aulacoseira (4). The diatom flora of both lakes was formed by cosmopolitan species with a large influence from species in alpine and subalpine area. A comparison of the diatom assemblages of the investigated lakes showed differences in both relative abundance and species present in the individual lakes. Bioindicative analysis showed that the water of Koçdüzü Great Lake is more alkaline and less saturated with organic substances than Avusor Great Lake. In both lakes, the communities are composed of species adapted to living in the benthos of fresh waters of moderate temperature well enriched with oxygen. In both lakes, the water quality was Class 2 with a saprobity index of S = 1.08 in Avusor Great Lake and 0.97 in Koçdüzü Great Lake, but their communities were composed of species with both oligotrophic and mesotrophic status. Statistical comparison of the species composition of studied lakes with other high mountain lakes and the lakes in northern Turkey revealed the role of altitude as the main factor in the formation of diatom floras.
Seroprevalence and Risks Factors Associated with Coxiella burnetii Infection in Slaughterhouse Zebu Cattle (Bos indicus) from Northern Regions of Cameroon
Authors: Zangue Camille Teitsa , Kouamo Justin , Ngoula Ferdinand , Tawali Ludovic Pépin M’bapté , Talla Mathias Mba , Mbeba Lionnel Yvan Kantchouet , Doumtsop Claude Landry Makuetamang , Tangwa Bernard Viban
Published: October 2022

A study was conducted to determine the seroprevalence and risks factors of Coxiella burnetii in zebu cattle from the northern regions of Cameroon. From a total of 2016 (1754 females and 262 males) sera sampled, 801, 762 and 453 were collected, respectively, from Adamawa, North and Far North, and screened for Coxiella burnetii using indirect enzyme-linked immunosorbent assay (iELISA). A total of 23.76% (479/2016) were serologically positive. The seroprevalence of Adamawa, North and Far North were 29.09% (233/801), 19.95% (152/762) and 20.75% (94/453); respectively. The seropositivity of male and female were 4.58% and 26.62%; respectively. Cattle from Adamawa region were more likely to have been exposed to C. burnetii than animals from Far North region (OR = 3.28; 95%CI: 1.13–7.85; p = 0.02). The Gudali breed was significantly more infected than Aku (OR =2.52; 95%CI: 1.06–5.99; p = 0.03), and animals aged of (6–9) years were 1.89 times more likely to have been infected to C. burnetii than young animals (p = 0.03). The seropositivity to this bacterium was significantly associated to pregnant cattle than non-pregnant (OR = 1.71; 95%CI: 1.01–2.90; p = 0.04). Female cattle were more likely to have been infected by C. burnetii than male and the rainy season were 1.66 more associated to this disease than dry season. The linear regression model indicated that C. burnetii seropositivity were positively correlated to the regions (0.09, CI: 0.04; 0.18; p = 0.007), age (0.01, CI: −0.01; 0.04; p = 0.02), sex (0.19, CI: 0.08–0.32, p = 0.001) and physiological status (0.11, CI: −0.04; 0.26; p = 0.006). This study revealed that C. burnetii infection is widespread among zebu cattle of Adamawa, North and Far North of Cameroon.
Dissecting microRNA−Target Gene Pairs Involved in Rubber Biosynthesis in Eucommia ulmoides
Authors: Liu Huimin , Hu Jingjing , Du Hongyan , Wang Lu , Qing Jun
Published: October 2022

MicroRNAs (miRNAs) play essential roles in regulating various development processes in plants. However, their role in regulating rubber biosynthesis in Eucommia ulmoides is largely unknown. Rubber is mainly distributed in the tissue covering the seed (GZ) rather than the periphery (GB) of the pericarp of E. ulmoides during accumulation in May. To investigate the roles of miRNAs in rubber biosynthesis, we conducted high-throughput small RNA sequencing using GZ and GB collected on 11 May (rapid accumulation) and 11 June (reduced accumulation). In total, 12 and 25 miRNAs were either up- or downregulated in GZ in May (GZ511) compared to GB (GB511) in May, while 27 and 38 miRNAs were either up- or downregulated in GZ in May compared to GZ in June (GZ611), respectively. Functional analyses of differentially expressed (DE−) genes targeted by DE-miRNAs revealed that miRNAs may regulate genes involved in rubber biosynthesis. For instance, when Eu-miR45 expression declined, the expression of its predicted target, small rubber particle protein 1 (EuSRPP1), increased in GZ511 vs. GB511 and GZ511 vs. GZ611, possibly resulting in higher rubber accumulation in GZ511. Additionally, we identified potential lncRNA−miRNA−mRNA networks in rubber biosynthesis. Overall, these results indicate that miRNAs play pivotal roles in regulating rubber biosynthesis via miRNA-target gene pairs and lncRNA−miRNA−mRNA networks in E. ulmoides. Our findings will enhance research on the mechanisms of rubber biosynthesis in plants.
Species Richness Promotes Productivity through Tree Crown Spatial Complementarity in a Species-Rich Natural Forest
Authors: Xu Yaozhan , Chen Han Y. H. , Xiao Zhiqiang , Wan Dan , Liu Feng , Guo Yili , Qiao Xiujuan , Jiang Mingxi
Published: October 2022

Ecological theory suggests that species with complementary architectural and physiological traits can optimize crown packing to improve resource efficiency and promote ecosystem productivity in forest communities. However, empirical evidence of this prediction is rare in species-rich natural forests, as little is known about how crown spatial complementarity regulates community species richness-productivity relationship (SRPR). In this study, we measured tree architectural traits (stem diameter, height, crown depth and width) for 11,337 trees, and quantified species richness, functional diversity, crown spatial complementarity, soil fertility and forest productivity for 44 quadrats (20 m × 20 m per quadrat) in the Badagongshan 25 ha forest plot, central China. We tested bivariate correlations between species richness, crown complementarity, functional diversity and forest productivity. We employed linear mixed effects models to predict crown complementarity and examined its relationship with functional diversity. Finally, we applied structural equation modeling to quantify the mediation effects of crown complementarity on SRPRs. Species richness promoted crown complementarity and forest productivity. Crown complementarity varied across quadrats, with increases driven primarily by changes in tree height. Crown complementarity was positively related to functional diversity and forest productivity. Species richness increased with soil total phosphorus, while functional diversity decreased with soil bulk density. Forest productivity increased with soil organic carbon and total nitrogen, but decreased with bulk density. Crown complementarity partially mediated the positive effect of species richness on forest productivity, and the mediation effect was mainly through functional diversity. Our results suggest that the crown complementarity index accurately reflects the niche complementarity through light utilization and carbon reallocation. Our study emphasizes that species richness can promote crown complementarity, leading to greater forest productivity, which provides greater insight into the mechanical understanding of the SRPRs.
The Use of Bryophytes, Lichens and Bromeliads for Evaluating Air and Water Pollution in an Andean City
Authors: Carrillo Washington , Calva James , Benítez Ángel
Published: October 2022

Air and water pollution are global environmental problems; thus, bioindicators have become important tools for monitoring various pollutants, including metals and metalloids. Parmotrema arnoldii (Du Rietz) Hale and Tillandsia usneoides L. were evaluated as indicators of heavy metals in the air and Platyhypnidium aquaticum A. Jaeger and Marchantia polymorpha L. as indicators of heavy metals and a metalloid in water. The concentrations of cadmium (Cd), lead (Pb), copper (Cu), manganese (Mn) and zinc (Zn) as air pollutants and aluminum (Al), cadmium (Cd), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn) and arsenic (As) as water pollutants were analyzed within four different zones (control, northern, central and southern) in an Andean city of Ecuador. The level of metal concentrations in the air for P. arnoldii and T. usneoides had the following order of concentration: Zn > Mn > Pb > Cd > Cu. In the case of water, P. aquaticum pointed out a concentration of Al > Mn > Fe > Zn > As > Pb > Cd and proved to be more effective in detecting water pollution than the species M. polymorpha, which had a concentration of Al >Zn > Fe > Cd >As > Mn > Pb. P. aquaticum showed a higher capacity to accumulate heavy metals than M. polymorpha; therefore, it can be used as a model species for passive water quality monitoring. However, P. arnoldii and T. usneoides showed similar heavy metal accumulation related to air quality. The passive monitoring of air quality using bromeliads and lichens as well as bryophytes for water quality proved their effectiveness and applicability in tropical regions such as Ecuador.
Past Experience, Motivation, Attitude, and Satisfaction: A Comparison between Locals and Tourists for Taihu Lake International Cherry Blossom Festival
Authors: Li Jian , Zhong Yizhou , Li Yanni , Hu Wu , Deng Jinyang , Pierskalla Chad , Zhang Fu’an
Published: October 2022

Although urban forests are important components of the urban tourism system, research on urban forests from the perspective of tourism is limited. This is particularly true for research on cherry blossom festivals held in urban areas in the context of China. This paper, for the first time, examined the similarities and differences between locals and tourists in their past experience, motivation, attitude, satisfaction, and loyalty as well as the interrelationships among these variables as they relate to the Taihu Lake International Cherry Blossom Festival (TLICBF) in Wuxi City, Jiangsu Province, China, based on data collected onsite in 2019 from 412 usable questionnaires. Results show that responses from locals and tourists were quite similar. Moreover, TLICBF attendees’ motivation of attending the festival significantly influenced their attitudes toward the festival, which significantly predicted their overall satisfaction with the festival. It is worth noting that it is the positive comparison, not the frequency of visits, that significantly influenced TLICBF attendees’ attitudes toward and overall satisfaction with the festival. In addition, motivations and benefits were also qualitatively examined, with a measure of 21 items for the former and 25 items for the latter being developed. Research implications, research limitations, and future research needs are discussed.
Mycobiota Associated with Symptomatic and Asymptomatic Fraxinus excelsior in Post-Dieback Forest Stands
Authors: Bakys Remigijus , Pliūra Alfas , Bajerkevičienė Gintarė , Marčiulynas Adas , Marčiulynienė Diana , Lynikienė Jūratė , Menkis Audrius
Published: October 2022

In Lithuania, the dieback of European ash (Fraxinus excelsior L.), caused by alien ascomycete Hymenoscyphus fraxineus, started in the mid-1990s, resulting in a large-scale decline of F. excelsior and its dominated forest habitats. Nevertheless, the recent inventories show the presence of several hundred hectares of naturally regenerated F. excelsior stands. We used seven naturally regenerated sites and three planted progeny trials of F. excelsior to collect leaves, shoots, roots, and the surrounding soil to study ash-associated fungal communities based on high-throughput sequencing. Results showed that fungal communities associated with F. excelsior in re-emerging stands in post-dieback areas were composed of 1487 fungal taxa. Among these, 60.5% were Ascomycota, 37.5%—Basidiomycota, 1.7%—Zygomycota, and 0.2% were Chytridiomycota. Revealed mycobiota was largely composed of endophytic fungal communities as these were dominated by Cladosporium sp., Fraxinicola fraxini (syn. Venturia fraxini) and Vishniacozyma foliicola. Identified mycobiota also included a range of ash-specific fungal taxa. Hymenoscyphus fraxineus occurred in all stands but was not frequent. Cladosporium sp. showed strongest negative correlation with the presence of H. fraxineus. This ascomycete, given its dominance in leaves, shoots and in the organic soil layer, might be the limiting factor for the infection rate or spread of H. fraxineus. Although fungal communities in asymptomatic and symptomatic samples of F. excelsior differed significantly from each other, the majority of the most frequently found fungal taxa were not host-specific, suggesting that these were negligibly affected by ash dieback. Investigated stands in natural F. excelsior habitats exhibited larger diversity of fungal taxa (especially ash-specific), than progeny trials planted on former grasslands, indicating the importance of natural habitats in F. excelsior restoration programs.
Prediction of Suitable Habitats for Sapindus delavayi Based on the MaxEnt Model
Authors: Li Yongxiang , Shao Wenhao , Huang Shiqing , Zhang Yongzhi , Fang Hongfeng , Jiang Jingmin
Published: October 2022

Sapindus delavayi (Franch.) Radlk. (S. delavayi) is an important biological washing material and biomass energy tree species with a peel rich in saponins and a kernel high in oil content. We used the maximum entropy model (MaxEnt) to predict the suitable habitats for S. delavayi in China, screen the dominant environmental factors affecting its distribution, and analyze the changes in its suitable habitats under future climate change. The results provide a scientific basis for its introduction, cultivation, and germplasm resource collection and protection. Twenty-two environmental variables and China distribution data for S. delavayi were used to construct the species distribution model, and the receiver operating characteristic (ROC) curve was used to verify the model’s accuracy. The dominant environmental factors were screened through the jackknife method, then a geographical information system (ArcGIS) was used to determine the level of suitable habitat division and area calculation. The results showed that the MaxEnt model had an excellent predictive effect for which the area under the ROC curve (AUC) value was as high as 0.959. The annual precipitation (Bio18), minimum temperature of the coldest month (Bio6), temperature seasonality (Bio4), and precipitation of the coldest quarter (Bio19) were the dominant environmental factors that affected the distribution of S. delavayi. Under the current climate, the suitable area for S. delavayi is 1,321,308.07 km2, and under the four climate scenarios for the 2050s and 2090s, the suitable area is predicted to change by −3.97%~2.57%. Overall, the centroids of the highly suitable habitats will shift by different degrees to the southwest in the future.
Forest Therapy Trails: A Conceptual Framework and Scoping Review of Research
Authors: Gobster Paul H. , Schultz Courtney L. , Kruger Linda E. , Henderson John R.
Published: October 2022

While most definitions of forest therapy emphasize the role of multisensory, immersive experiences in nature to achieve human health and wellbeing outcomes, reviews of research on forest therapy to date have predominantly focused on outcomes and provide limited insight on the factors and conditions that give rise to nature experiences. In this scoping review we employ a conceptual framework developed in the context of landscape perception research to examine empirical studies of forest therapy in terms of how the fuller process of human, forest, interaction, and outcome components are conceptualized and measured. Our literature search identified 266 studies focused on forest therapy and related activities, which were coded on a number of variables related to each of the four components in our framework. While most studies reported positive mental and/or physiological health outcomes using a wide array of measures, the typical study used small, homogeneous samples of participants who engaged in limited interactions with a forest environment that was minimally described. However, our analysis also identified a wider range of findings with regard to human-forest interactions, which together provide important insights for guiding forest therapy research and the provision of forest therapy trails, settings, and programs.
Environmentally Friendly Starch-Based Adhesives for Bonding High-Performance Wood Composites: A Review
Authors: Maulana Muhammad Iqbal , Lubis Muhammad Adly Rahandi , Febrianto Fauzi , Hua Lee Seng , Iswanto Apri Heri , Antov Petar , Kristak Lubos , Mardawati Efri , Sari Rita Kartika , Zaini Lukmanul Hakim , Hidayat Wahyu , Giudice Valentina Lo , Todaro Luigi
Published: October 2022

In recent years, bio-based wood adhesives have gained an increased industrial and research interest as an environmentally friendly and renewable alternative to the commercial petroleum-based synthetic adhesives used in the wood-based industry. Due to its renewability, abundance, relatively low price, and good adhesion properties, starch is a promising natural feedstock for synthesizing bio-based adhesives for wood-based composites. This review aims to summarize the recent advances in developing sustainable starch-based wood adhesives for manufacturing non-toxic, low-emission wood composites with enhanced properties and lower environmental impact. Recent developments in starch modification, physical, and enzymatic treatments applied to improve the performance of starch-based wood adhesives, mainly in terms of improving their water resistance and bonding strength, are also outlined and discussed.
Multi-Directional Rather Than Unidirectional Northward-Dominant Range Shifts Predicted under Climate Change for 99 Chinese Tree Species
Authors: Li Guoqing , Huang Jinghua
Published: October 2022

Climate change has a profound impact on the distribution of species on Earth. At present, there are two contrasting views explaining the direction of species range shifts. One is a single poleward (northward in the Northern Hemisphere) view, while the other is a multi-directional view (e.g., westward, southward, and eastward). Exploring the universality of these two views has become a key focus in climate change ecology. Here, we study the habitat range shift velocity of 99 tree species in China under future climate change scenarios using a bioclimatic envelope model (also called species distribution model) and a climate velocity method. A Monte Carlo method is used to test the consistency between the range shift pattern and stochastic process, and confusion matrices and kappa values are calculated to evaluate the consistency between the bioclimatic envelope model and climate velocity method. The results indicate that the tree species in China are generally expected to shift northwards, with northwest and northeast directions accounting for a larger proportion. The northward-shifting species are mainly distributed in the east monsoon region of China, while the multi-directional shifting species are mainly distributed in the alpine and arid regions of China. The shift directions described by the bioclimatic envelope model are inconsistent with those described by the climate velocity method. The results imply that the tree species in China support the view of the northward shift pattern but, more specifically, should be considered in terms of a multi-directional northward shift pattern. The results also emphasize that the inter-species variation in climate tolerance has been largely ignored in physical-based climate velocity methods. The development of a biological and vector operation-based climate velocity indicator may be more useful in characterizing the range shifts of species, compared to existing physical and scalar operation-based climate velocity indicators. This study provides favorable evidence for the pattern of climate change-induced range shifts in China, as well as in Eastern Asia.
Effect of Acetylation on the Physical and Mechanical Performances of Mechanical Densified Spruce Wood
Authors: Guo Jianhui , Wang Chao , Li Cheng , Liu Yang
Published: October 2022

Inherent drawbacks (e.g., loose structures, dimensional instabilities, and poor mechanical performances) restrict the applications of fast-growing wood species. In this study, a thermal compression treatment was carried out to densify acetylated spruce wood. The aim of acetylation was to improve the plasticity and water resistance of spruce wood. The water absorption, set-recovery, surface hardness, modulus of rupture, modulus of elasticity, and microstructure of the resulting wood were analyzed. The results show that acetylation can improve the plasticity of wood and reduce the interaction between wood and water, significantly reducing the set recovery of the compressed wood. When the water immersion time reaches 168 h, the water absorption rate of wood is reduced by 37% after acetylation, and the densification can further reduce the water absorption (55% for AD-40 and 70% for AD-60). The hardness of the densified wood is significantly higher than that of control wood and increases with the increase of the compression ratio. The cell wall of acetylated wood is thicker than that of control wood, which could increase the compression density of the wood. As a result, the hardness and MOR of acetylated densified wood are remarkably higher than that of unacetylated densified wood. However, a high compression ratio (60%) could lead to structural damage and, thus, reduce the mechanical properties.
Extreme Winter Storms Have Variable Effects on the Population Dynamics of Canopy Dominant Species in an Old-Growth Subtropical Forest
Authors: Yang Yidan , Ji Yanli , Wang Yunquan , Xie Jiajie , Jin Yi , Mi Xiangcheng , Yu Mingjian , Ren Haibao , Ma Keping , Chen Jianhua
Published: October 2022

Extreme climatic events are predicted to increase in frequency and magnitude as global climate change continues. Extreme climatic events have profound impacts on community structure and dynamics, but their effects on the dominant species within a community remains unclear. To explore this issue, we analyzed changes in population dynamics and dead individuals’ spatial pattern for several dominant species (Castanopsis eyrei, Schima superba, Pinus massoniana, and Daphniphyllum oldhamii) among different habitats in a subtropical forest before and after a significant winter storm that occurred in February 2008. Using the Gutianshan 24-ha forest plot as a representative sample, we found that the plot-level DBH of P. massoniana and C. eyrei significantly increased after the winter storm, while the plot-level basal area of P. massoniana and S. superba decreased significantly. In addition, P. massoniana was most affected by the storm (mortality: 9.08%; population change rate: −8.93%), followed by C. eyrei (mortality: 6.93%; population change rate: −4.91%). Small-diameter individuals experienced higher mortality rates, but the diameter structure of the dominant species at the population level remained basically stable. The number of individuals, the density of the dominant population, the number of mortalities, and the mortality rate of the dominant species differed among habitats. The spatial point patterns of the dead individuals at each life stage were mainly aggregated in distribution, and the degree of aggregation tended to decrease with increasing scale. In conclusion, the population dynamics of dominant species were significantly altered following the winter storm, but the extent of the changes varied with species. Our study suggests that analyzing the dominant species of a community contributes to a better understanding of the biological response of forest ecosystems in the face of extreme climatic events.
Error Analysis on the Five Stand Biomass Growth Estimation Methods for a Sub-Alpine Natural Pine Forest in Yunnan, Southwestern China
Authors: Chen Guoqi , Zhang Xilin , Liu Chunxiao , Liu Chang , Xu Hui , Ou Guanglong
Published: October 2022

Forest biomass measurement or estimation is critical for forest monitoring at the stand scale, but errors among different estimations in stand investigation are unclear. Thus, the Pinus densata natural forest in Shangri-La City, southwestern China, was selected as the research object to investigate the biomass of 84 plots and 100 samples of P. densata. The stand biomass was calculated using five methods: stand biomass growth with age (SBA), stem biomass combined with the biomass expansion factors (SB+BEF), stand volume combined with biomass conversion and expansion factors (SV+BCEF), individual tree biomass combined with stand diameter structure (IB+SDS), and individual tree biomass combined with stand density (IB+SD). The estimation errors of the five methods were then analyzed. The results showed that the suitable methods for estimating stand biomass are SB+BEF, M+BCEF, and IB+SDS. When using these three methods (SB+BEF, SV+BCEF, and IB+SDS) to estimate the biomass of different components, wood biomass estimation using SB+BEF is unsuitable, and root biomass estimation employing the IB+SDS method was not preferred. The SV+BCEF method was better for biomass estimation. Except for the branches, the mean relative error (MRE) of the other components presented minor errors in the estimation, while MRE was lower than other components in the range from −0.11%–28.93%. The SB+BEF was more appealing for branches biomass estimation, and its MRE is only 0.31% lower than SV+BCEF. The stand biomass strongly correlated with BEF, BCEF, stand structure, stand age, and other factors. Hence, the stand biomass growth model system established in this study effectively predicted the stand biomass dynamics and provided a theoretical basis and practical support for accurately estimating forest biomass growth.
Are Existing Modeling Tools Useful to Evaluate Outcomes in Mangrove Restoration and Rehabilitation Projects? A Minireview
Authors: Rivera-Monroy Victor H. , Zhao Xiaochen , Wang Hongqing , Xue Zuo George
Published: October 2022

Ecosystem modeling is a critical process for understanding complex systems at spatiotemporal scales needed to conserve, manage, and restore ecosystem services (ESs). Although mangrove wetlands are sources of ESs worth billions of dollars, there is a lack of modeling tools. This is reflected in our lack of understanding of mangroves’ functional and structural attributes. Here, we discuss the “state of the art” of mangrove models used in the planning and monitoring of R/R projects during the last 30 years. The main objectives were to characterize the most frequent modeling approach, their spatiotemporal resolution, and their current utility/application in management decisions. We identified 281 studies in six broad model categories: conceptual, agent-based (ABM), process-based (PBM), spatial, statistical, and socioeconomic/management (ScoEco). The most widely used models are spatial and statistical, followed by PBM, ScoEco, and conceptual categories, while the ABMs were the least frequently used. Yet, the application of mangrove models in R/R projects since the early 1990s has been extremely limited, especially in the mechanistic model category. We discuss several approaches to help advance model development and applications, including the targeted allocation of potential revenue from global carbon markets to R/R projects using a multi-model and integrated approach.
Multi-Objective Optimization of Beverage Based on Lactic Fermentation of Goat’s Milk Whey and Fruit Juice Mixes by Kefir Granules
Authors: Nastar Marcillo Diana Alexandra , Olmedo Galarza Valeria , Pinto Mosquera Nicolás Sebastián , Espín Valladares Rosario del Carmen , Núñez Pérez Jimmy , Pais-Chanfrau José Manuel
Published: October 2022

Numerous fruits are produced in Ecuador, of which about 40% are never eaten. In addition, fresh goat cheeses are in high demand. However, goat cheese generates goat milk whey with high contamination loads, and, therefore, it must be adequately treated before being discharged into ecosystems. This research aims to use a mixture of tree tomato, common strawberry juices, and goat’s milk whey, to be statically fermented by milk and water kefir grains (WKG) for 48 h. For this, a dual mixture design of L-optimal response surface methodology was carried out to find the conditions that maximized all the responses evaluated (lactic-acid bacteria and yeasts concentrations and the overall acceptability assessed on a 7-point scale). Experiments were carried out in San Gabriel, Ecuador. Temperatures during the day and night were 20.2 ± 0.3 °C and 18.7 ± 0.3 °C, respectively. Three conditions were selected, where the highest response values were reached. Complementary experiments demonstrated the validity of the models. When comparing the results of the present study with similar ones carried out previously, higher values were observed in the concentration of yeasts, which seems related to the presence of the WKG. It is concluded that they could be suitable functional beverage candidates.
The Biorefinery of the Marine Microalga Crypthecodinium cohnii as a Strategy to Valorize Microalgal Oil Fractions
Authors: Moniz Patrícia , Martins Daniela , Oliveira Ana Cristina , Reis Alberto , Lopes da Silva Teresa
Published: October 2022

Chrypthecodinium cohnii lipids have been almost exclusively used as a source of Docosahexaenoic acid (DHA). Such an approach wastes the remaining microalgal lipid fraction. The present work presents a novel process to produce C. cohnii biomass, using low-cost industrial by-products (raw glycerol and corn steep liquor), in a 7L-bioreactor, under fed-batch regime. At the end of the fermentation, the biomass concentration reached 9.2 g/L and the lipid content and lipid average productivity attained 28.0% (w/w dry cell weight) and 13.6 mg/L h, respectively. Afterwards the microalgal biomass underwent a saponification reaction to produce fatty acid (FA) soaps, which were further converted into FA ethyl ester (FA EE). C. cohnii FA EE mixture was then fractionated, using the urea complexation method at different temperatures, in order to obtain a polyunsaturated fatty acid ethyl ester (PUFA EE) rich fraction, that could be used for food/pharmaceutical/cosmetic purposes, and a saturated fatty acid ethyl ester (SAT EE) rich fraction, which could be used as biodiesel. The temperature that promoted the best separation between PUFA and SAT EE, was −18 °C, resulting in a liquid fraction with 91.6% (w/w) DHA, and a solid phase with 88.2% of SAT and monounsaturated fatty acid ethyl ester (MONOUNSAT), which could be used for biodiesel purposes after a hydrogenation step.
Transformation of Gardenia Yellow Waste Production into Gardenia Blue Pigment by Leifsonia sp. ZF2019 and Evaluation of Its Physicochemical Stability
Authors: He Yi , Jiao Ronghu , Wang Xi , Wang Chenxi , Zhang Zhi , Xu Guangzhi
Published: October 2022

To produce gardenia blue pigment (GBP) by natural fermentation, a novel bacteria, Leifsonia sp. ZF2019, was isolated from the larvae of a pest of Gardenia jasminoides Ellis fruits and shown to be able to convert gardenia yellow waste production (GYWP) into GBP. The fermentation medium and growth conditions were screened, and the GBP yield, color value, and stability were compared to those of Aspergillus niger fermentation. Leifsonia sp. ZF2019 was shown to effectively produce GBP in medium containing GYWP and leucine (Leu). A temperature of 35 °C, 0.8% leu content, a fermentation period of 72 h, and a pH value of 7.0 were shown to be optimal culture conditions. GBP produced by Leifsonia sp. ZF2019 was of higher yield and quality than that produced by Aspergillus niger fermentation. GBP was purified by D4020 macroporous adsorbent resin, and the effects of pH, temperature, light, oxidant and reductant, conventional food additives, and metal ions on its stability were evaluated. GBP produced by Leifsonia sp. ZF2019 fermentation was as stable as GBP generated directly by pure genipin. LC-MS revealed that the molecular formula of GBP was C37H45N2O8. Our results provide a reference for the preparation of efficient, stable, reliable, and high-quality gardenia blue pigments.
Involvement of Cytochrome P450 in Organic-Solvent Tolerant Bacillus subtilis GRSW1-B1 in Vanillin Production via Ferulic Acid Metabolism
Authors: Kotchaplai Panaya , Ninrat Jedsadakorn , Mahipant Gumpanat , Vangnai Alisa S.
Published: October 2022

The detection of vanillin during the metabolism of ferulic acid by several Bacillus strains has been reported; however, its occurrence is not yet understood. Herein, the potential enzymes involved in vanillin production during ferulic acid metabolism in the previously reported butanol-tolerant Bacillus subtilis strain GRSW1-B1 were explored. The recombinant E. coli cells that overexpressed phenolic acid decarboxylase (PadC) rapidly converted ferulic acid to 4-vinylguaiacol. The detection of vanillin was concurrent with a decrease in 4-vinylguaiacol. In addition, the reversible abiotic conversion of 4-vinylguaiacol and apocynol was observed. The overexpression of CypD, a Bacillus P450, resulted in notable production of vanillin. The two-step conversion of ferulic acid yielded 145 μM over 72 h at pH 9. Vanillin yields of approximately 258 μM and 212 μM were obtained from ferulic acid metabolism by recombinant E. coli coexpressing PadC and CypD after conversion for 72 h, at pH 9 and 10, respectively. Several possibilities that underlie the production of vanillin were discussed. This information is useful for understanding ferulic acid metabolism by Bacillus strains and for further improving this strain as a host for the production of valuable compounds from biomass.
Evaluation of Three Marine Algae on Degradability, In Vitro Gas Production, and CH4 and CO2 Emissions by Ruminants
Authors: Lee-Rangel Héctor Aarón , Roque-Jiménez José Alejandro , Cifuentes-López Rubén Oswaldo , Álvarez-Fuentes Gregorio , Cruz-Gómez Adriana De la , Martínez-García José Antonio , Arévalo-Villalobos Jaime Iván , Chay-Canul Alfonso Juventino
Published: October 2022

Livestock production systems are responsible for producing ~18% of the total anthropogenic greenhouse gas (GHG) emissions. Numerous alternatives, such as feed additives or supplements, have been proposed to meet these challenges. Marine algae have been proposed for gas reduction in ruminants; nevertheless, there are still very few experimental reports. Thus, the objective of the current study was to identify the volatile organic compounds (VOCs) in three marine algae—Kelp (Macrocystis pyrifera), Ulva (Ulva spp.), and Silk (Mazzaella spp.)—and to test their in vitro ruminal fermentation characteristics, gas profiles, and ability to mitigate biogas production. The evaluation of the VOCs in marine algae was performed using a flash gas chromatography electronic nose (FGC-E-Nose). The in vitro study was elaborated through in vitro incubation and gas production. The data obtained were analyzed using a completely randomized design. In total, forty-three volatile compounds were identified for Kelp algae, thirty-eight were identified for Ulva algae, and thirty-six were identified for Silk algae; the compounds were from different chemical families and included aromas, alcohols, aldehydes, phenolics, carboxylic acids, esters, and nutraceutical properties. Dry matter degradability was significantly (p < 0.05) affected by the algae type. The cumulative ruminal gas production was different (p < 0.05) between treatments. Kelp algae presented a major (V; p < 0.05) volume of gas produced compared to the other algae. Lag time (l; p < 0.05) was increased by Kelp alga; however, there were no differences (p>0.05) between the Silk and Ulva algae. The gas production rate was higher (s; p < 0.05) for Silk algae compared to the others. Ulva and Silk algae demonstrated a significant (p < 0.05) decrease in carbon dioxide emissions. Nevertheless, Kelp algae reduced the proportional methane (CH4) production (p < 0.05) after 48 h of incubation, with the lowest emission rate of 47.73%. In conclusion, algae have numerous bio compounds that provide some properties for use in ruminant diets as additives to reduce methane and carbon dioxide emissions.
Bioactivity of Organic Fermented Soymilk as Next-Generation Prebiotic/Probiotics Mixture
Authors: Abdelghani Dina Y. , Gad Abdallah I. , Orabi Mona M. , Abou-Taleb Khadiga A. , Mahmoud Emam A. , Al Amoudi Soha A. , Zari Ali , Althubaiti Eman Hillal , Edris Sherif , Amin Shimaa A.
Published: October 2022

Fermented soymilk (soymilk yogurt) was made by fermenting soymilk with five probiotic bacterial strains (Lactobacillus plantarum ATCC 14917, Lactobacillus casei DSM 20011, Lactobacillus acidophilus ATCC 20552, Lactococcus thermophilus DSM 20259, and Bifidobacterium longum B41409) that were used as monocultures and combined with them as consortia cultures. Seven pathogenic strains, E. coli O157H7, S. aureus As4, S. typhimurium As3, S. shigae As2, L. monocytogenes As1, P. aeruginosa ATCC 27853, and B. cereus Dsmz 345, were used to study the antibacterial activity of fermented soymilk by agar well diffusion assay. Results indicated that Gram-negative pathogenesis was more sensitive to probiotic cultures than Gram-positive pathogenesis. E. coli O15H7, S. typhimirium As3, and Shigella shigae As2 were more sensitive to probiotic cultures, presenting inhibition zone diameters (IZA) ranging from 10 to 20 mm, 12 to 16 mm, and 10 to 16 mm, respectively. At the same time, P. aeruginosa Atcc 27853 showed the lowest (IZA), ranging from 3 mm to 8 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at various concentrations of soymilk fermented by T1, T4, and T5, ranging from 0.031 mg/mL to 1 mg/mL against pathogenic bacterial strains. The sensory properties of FSM were evaluated, and sensory analysis during soymilk fermentation showed significant improvement. The effect of shelf life (storage period) on FSM quality and properties was evaluated; during shelf life (storage period), FSM saved its properties and quality after 28 days of cold storage. Finally, it was stated that the soymilk yogurt can be used as a substitute for buffalo and cow milk for therapeutic feeding in the future.
Integrated Marine Biogas: A Promising Approach towards Sustainability
Authors: Faisal Shah , Zaky Abdelrahman , Wang Qingyuan , Huang Jin , Abomohra Abdelfatah
Published: October 2022

Fossil fuel depletion, climate change, and increased global energy demands are the driving forces to find alternative sources of energy. Marine-based biorefinery has been recently discussed as a promising route to mitigate the environmental challenges, enhance the energy recovery, and provide a potential source for value-added products. Anaerobic digestion is a promising technology that can convert the organic compounds of marine ecosystems into biogas. To date, a comprehensive review incorporating integrated biogas potential and effective approaches to enhance seaweed digestibility for biogas production from marine resources has not been reported. Thus, the present review aims to explore and comprehensively present seaweed and other marine resources for potential biogas production. The basics and challenges of biogas production from seaweed are elucidated. The impact of biochemical composition on biogas and the microbial communities involved in anaerobic digestion of seaweed are discussed. Utilization of different techniques such as pretreatment, co-digestion, and sequential extraction of seaweed biomass to enhance the biogas yield and to mitigate the effect of inhibitors are presented. Specifically, this article evaluates the co-digestion of seaweed with other biomass feedstocks or liquid biowastes. Integration of marine microalgae cultivation on anaerobic digestate for value-added compound production, biogas upgrading, and bioenergy recovery provides a promising approach towards a zero-waste marine-based system.
Minimization of nth Order Rate Matching in Satellite Networks with One to Many Pairings
Authors: Roumeliotis Anargyros J. , Efrem Christos N. , Panagopoulos Athanasios D.
Published: October 2022

This paper studies the minimization of nth (positive integer) order rate matching in high-throughput multi-beam satellite systems, based on one-to-many capacity allocation pairings, for the first time in the literature. The offered and requested capacities of gateways and users’ beams are exploited, respectively. Due to the high complexity of the binary optimization problem, its solution is approached with a two-step heuristic scheme. Firstly, the corresponding continuous, in [0, 1], pairing problem is solved applying the difference of convex optimization theory, and then, a transformation from continuous to binary feasible allocation is provided to extract the pairings among gateways and users’ beams. Comparing with the exponential-time optimal exhaustive mechanism that investigates all possible pairs to extract the best matching for minimizing the rate matching, extended simulations show that the presented approximation for the solution of the non-convex optimization problem has fast convergence and achieves a generally low relative error for lower value of n. Finally, the simulation results show the importance of n in the examined problem. Specifically, pairings originated by the minimization of rate matching with larger n result in more fair rate matching among users’ beams, which is a valuable result for satellite and generally wireless systems operators.
Playful Meaning-Making as Prosocial Fun
Authors: Carroll John M. , Gui Fanlu , Gupta Srishti , Knearem Tiffany
Published: October 2022

Smart city infrastructures enable the routine interleaving and integration of diverse activities, including new ways to play, to be playful, and to participate. We discuss three examples: (1) citizen-based water quality monitoring, which combines outdoor exercise and social interaction with safeguarding public water supplies, (2) a digital scavenger hunt, which combines the experiences of a community arts festival with shared reflections about significant community places and events, and (3) public thanking, which encourages people to acknowledge neighbors and local groups that serve and strengthen the community. Each of these interaction possibilities in itself alters lived experience modestly. We argue that lightweight and playful meaning making activities can be prosocial fun, that is to say, they can simultaneously be playful and fun, but also substantive contributions to the coherence and richness of a community.
Effects of n-Butanol Addition on the Combustion Characteristics of n-Heptane Counterflow Diffusion Flame at Elevated Pressure
Authors: Ying Yaoyao , Liu Dong
Published: October 2022

This study focused on the effects of n-butanol addition on the combustion characteristics of n-heptane counterflow diffusion flame under pressures of 1, 3, and 5 atm by a detailed kinetic simulation. The added n-butanol volume fraction ranged from 0 to 50%. The mass averaged velocity of fuel streams was selected to ensure momentum flux balance and was approximately constant for the investigated flames. Flame structures and mole fraction profiles impacted by n-butanol addition for major species, free radicals, and intermediate species were analyzed by concentrating on the formations of soot precursors and oxygenated air pollutants. The results showed that with the addition of n-butanol, the flame temperature decreased and the formation of the main soot precursors such as C2H2 and C6H6 was inhibited. This can be attributed to the reduced rate of production of these species. The flame temperature increased significantly, and the profile moved towards the fuel side with the increasing pressure. Moreover, the production of C2H2 and C6H6 was observably promoted as the pressure increased. The concentrations of free radical H, O, and OH decreased significantly as the pressure increased but slightly decreased with the increasing n-butanol addition, which might have been caused by the chemical effect of n-butanol.
Compartment Fire Behavior at the Stages of Detection, Containment and Suppression Using Water Mist
Authors: Kuznetsov Geniy , Volkov Roman , Sviridenko Aleksandr , Zhdanova Alena
Published: October 2022

This paper presents experimental research findings regarding the characteristics of fire safety equipment activation before and after a water-based fire suppression system is triggered. A group of typical indoor combustible materials (wood, linoleum, cardboard, paper) were used to construct Class A model fires in the experiments. The three most frequent fire causes were reproduced: the careless handling of fire (open flame), the unsafe operation of heating equipment and electrical short circuits. To identify the fire behavior, an automated system including fire (heat, smoke, flame) detectors, contact and non-contact temperature measurement instruments, a gas analysis system and video recording equipment was employed. Following the experiments, the most efficient (in terms of detection speed and reliability) combinations of technical equipment that are necessary and sufficient to identify all the combustion stages of substances and materials were determined. The efficient consumption of a fire-extinguishing agent was found to be possible when fire development stages were controlled. Guidelines on creating automated fire prevention systems in buildings were provided. These have the potential to significantly speed up compartment fire suppression.
Numerical Study of the Effectiveness of a Firebreak in a Savanna Area and the Sizing Rules by an Optimised Fire Propagation Model
Authors: Brou Akahoua D. V.
Published: October 2022

Firebreaks are one of the techniques used to fight bushfires in Côte d’Ivoire. Their objective is to prevent the progression of fire and to protect sensitive sites. In this paper, a parametric study on the effectiveness of a firebreak in a savanna area is conducted using a fire spread model. The ability of the model to conduct this study was tested by an empirical model based on fire experiments in the Australian savanna. An agreement was found between the results predicted by our model and those of the empirical model. The parametric study conducted on the effectiveness of firebreaks indicated that a firebreak thickness equal to twice the flame length was effective. For bushfire control in Côte d’Ivoire, a firebreak with a minimum thickness of 8 m could stop the fire despite the slope of the land and the wind speed.