Avaldamisel

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Nüüd näidatakse 1 - 20 35

Innovative approach to real-time diagnostic of bolted joints and elastic couplings to prevent their fractures
(Estonian University of Life Sciences, 2024) Gorbacovs, D.; Gavrilovs, P.; Eiduks, J.; Gailis, M.
Failure of fasteners can lead to undesirable consequences. Fatigue failure of machine parts is difficult to predict and prevent. Vehicles and agricultural machinery include various systems such as engine, transmission, and many other systems that are fixed and connected using fasteners. Without a doubt, the performance of an individual system depends on the design of its kernel. But for the system to work, it must be properly fixed. Premature failure of bolts is subject of interest of engineers. The purpose of this study is to identify the causes of the failure of the fixing bolts and develop device and algorithm for early detection of conditions that might lead to bolt failure. The experimental data is collected analysing bolts and elastic couplings of electric passenger trains. Laboratory studies included the measurement of tensile strength, hardness, microanalysis of the metal structure and chemical analysis of failed old and new bolts. The authors present various visual and numerical results from this study. It also provides detailed conclusions about the causes of failure and recommendations for the selection of bolts for critical mechanical connections under dynamic loads and variable temperatures. The authors have developed a device that can be used in mechanical engineering, shipbuilding and other industries to control the deformation, vibration and shocks acting on a bolted joint. This device for monitoring the load and vibrations of bolted connections allows to constantly collect and analyse data during the operation of the vehicle in order to reduce the number of unscheduled repairs of vehicles due to its damage, as well as to reduce the number of accidents or other incidents. The authors also have developed a method and algorithm for calculating and evaluating the influence of external factors on the shell of a rubber-cord coupling. The study is based on statistical, material, and mathematical analysis of unexpected failures of rubber couplings. A numerical analysis of the operating conditions of the couplings before failure was performed. The results obtained are encouraging and prove that the use of an impact force measuring device and real-time data analysis can be cost-effective and can eliminate the problem of bolt and elastic coupling failure in one go, as well as reduce the cost of operating and repairing vehicles.
IGF1 and IGF2 gene polymorphisms are associated with the feed efficiency of fattened lambs in Latvian sheep breads
(Estonian University of Life Sciences, 2024) Trapina, I.; Plavina, S.; Krasņevska, N.; Paramonovs, J.; Kairisa, D.; Paramonova, N.
Feed efficiency is an economically important indicator in sheep farming. The most effective technology for selecting the best feed-efficient lambs for breeding is marker association selection of genetic variations in the sheep genome as potential biomarkers. In tissue growth and differentiation, insulin-like growth factors (IGFs) play a major role: IGF1 mediates the effects of growth hormone, and IGF2 is a growth regulator, regulating skeletal muscle growth. The study aims to find possible molecular markers for feed efficiency indicators in IGF1 and IGF2 genes for Latvian sheep breeds. The exonic regions of the IGF1 and IGF2 genes were sequenced for the first time in the genomic DNA of 76 controlled, intensively fattened lambs, to search for possible genetic biomarkers. Seven polymorphic loci in the IGF1 gene and sixteen in the IGF2 gene were detected. Statistically significant associations of the IGF1 SNP rs600896367 were found with residual indicators: Residual feed intake, Residual weight gain (RWG), and Residual intake and body weight gain (RIG), and with feed efficiency and feed conversion ratio in the overall group of samples. Additionally, IGF2 SNPs New_7 and rs429576107 exhibited associations with RWG and RIG specifically in the Latvian dark-head sheep group. On average, effect of the IGF1 SNP on associated feed efficiency residuals is 3.9%, with the most pronounced impact observed in RFI. In contrast, the influence of IGF2 SNPs is comparatively lower. Our results indicate that rs600896367 and New7/rs429576107 are potential molecular markers for marker-assisted selection in sheep breeding for residual feed efficiency indicators.
A participatory research approach in the development of safety and well-being in horticultural enterprises
(Estonian University of Life Sciences, 2024) Mattila, T.E.A.; Tuure, V.-M.; Ovaska, U.; Vänninen, I.; Hokka, M.; Elstob, T.; Rautiainen, R.H.
The process of improving the health, safety, and well-being of workers in the horticulture and agriculture sectors requires new effective means. The aim of this study was to conduct a qualitative evaluation of a participatory co-creative consultation process in order to improve occupational health and safety in horticultural businesses. The study was conducted across twenty-four small-scale enterprises (totalling eighty-two entrepreneurs and workers) from five different horticultural subsectors in Finland. Each business engaged in the development process, starting from the identification of development needs through to individual interviews and process analysis, and continuing with co-creation and the implementation of solutions. The results indicated that participatory consultation, when combined with a process analysis, was perceived as being very productive, particularly in terms of identifying development needs, but also in inspiring the co-creation of solutions and applying them to specific tasks and the working environment. Whilst long-term effects could not be measured, participation in the development process improved subjective well-being and the competence of entrepreneurs in managing wellbeing in their work setting. The findings suggest that participatory consultation can facilitate improvements in working conditions, which in turn can help to reduce workplace injuries and improve health conditions. The findings also highlighted the need for having a multidisciplinary consultation team, the effective cooperation of all involved parties, and facilitating peer discussions when it comes to resolving identified challenges.
The agricultural traffic effects on soil and maize (Zea mays L.) yields under two different tillage systems
(Estonian University of Life Sciences, 2024) Botta, G.F.; Ezquerra-Canalejo, A.; Romay, C.; Rivero, D.; Hidalgo, R.J.
This study investigated the agricultural traffic effects on soil and maize (Zea mays L.) yields under No-tillage (NT) and conventional tillage (CT) during three cropping seasons on an Entic Haplustoll soil. Cone index (CI), dry bulk density (DBD), soil water content (SWC), root dry matter per plant (RDM), seed emergence (SE) and maize yields (MY) were measured. The highest average RDM values were found in CT (60.6 g plant-1), while the highest value in NT was 48.0 g plant-1). After traffic, for the two tillage systems, the obtained CI results followed a similar trend to those of DBD up to 150 mm. From this depth, the values of both parameters increased sharply up to the 450 mm depth level. At 150 to 450 mm average CI and DBD values were higher than 1,680 kPa and 1,472 kg m-3, and 2,610 kPa and 1,677 kg m-3 for CT and NT, respectively. The average yields for the 3 cropping seasons were 9.93 ton ha-1 and 8.26 ton ha-1 for CT and NT, respectively. It was demonstrated that even using medium-weight equipment (479.8 kN), subsoil compaction could not be avoided.
Effect of electric vehicle mass change on energy consumption and the range
(Estonian University of Life Sciences, 2024) Berjoza, D.; Jurgena, I.; Millers, R.
The use of industrially produced electric cars has increased significantly in the last 13 years. The year 2010 can be considered the initial stage of mass production of electric cars when the manufacture of the Mitchubishi I–MiEV and the Nissan LEAF was started. For modern electric cars, the battery mass can reach up to 770 kg. If the electric car is intended for long distances, the large mass and capacity of the battery is justified because it is put to good use. If the electric car is mainly used in urban driving mode, an increase in the mass of a heavy battery can reduce the range or energy consumption per km. To identify the effect of change in the mass of an electric car on the amount of electricity consumed, experimental studies were carried out with a converted electric car Renault Clio. A 10 kWh battery with a mass of 125 kg was used for the electric car. A road experiment was conducted in Jelgava city on a route that included streets of different traffic intensity with two different loads for the electric car. With an additional load for the electric car, the mass increase was simulated as if the mass of the battery was doubled. The road experiment showed that on the same city route, an increase in the mass of the electric car increased energy consumption by 5.8%, which in turn increased operating costs.
Phylogenetic diversity and relationships among sorghum genotypes of breeding collection
(Estonian University of Life Sciences, 2024) Honcharov, Y.; Yalanskyi, O.; Prysiazhniuk, L.; Dikhtiar, I.; Melnyk, S.; Hryniv, S.; Tahantsova, M.; Holichenko, N.
Sorghum is gaining prominence as a biofuel crop, currently taking the position as the second-largest source of grain-based ethanol after maize. Estimation of genetic diversity to identify groups with similar genotypes is important for conserving, evaluating and utilizing genetic resources. This study aimed to evaluate the genetic diversity and population structure in different genotypes of sorghum collection for breeding purposes to improve cultivars. There were investigated thirty-one sorghum genotypes of different origin. The genetic diversity of sorghum genotypes was assessed by five SSR markers. To evaluate morpho-agronomical traits, days to flowering, plant high, 1,000 seeds weight and yield were studied. As the result of analysis, four cluster groups were formed based on Roger’s & Tanimoto dissimilarity. These cluster groups included from three to sixteen sorghum genotypes, one genotype K2105 formed the separate cluster. The Shannon index calculated based on SSR markers was 1.99. Two principal components explained approximately 63% of the total variance. The greatest effect of year weather conditions was observed on the trait ‘days to flowering’. The plant height was affected by the genotype of grain sorghum. The yield and 1,000 seed weight were affected by weather conditions, but the impact rate was significantly lower than the effect of days to flowering. The correlation between SSR markers and trait ‘days to flowering’ based on distances matrices was weak, but significant (r = 0.1). Thus, obtained results can be utilized for revealing genetic variation and identifying slightly different genotypes in a sorghum breeding program.
Spatial and temporal variability of enthalpy and its influence on the cloacal temperature of broilers
(Estonian University of Life Sciences, 2024) Silva, M.A.J.G.; Santos, L.M.D.; Ribeiro, J.C.D.; Barbari, M.; Becciolini, V.; Naves, L.P.; Ferraz, P.F.P.
Strategies aimed at mitigating heat stress conditions pose a challenge for the poultry industry operating in tropical climate zones. The primary aim of this research was to characterize and analyze the specific enthalpy of air (h, in kJ kg of dry air−1) in a broiler house using geostatistical techniques. In addition, its relationship with the cloacal temperature (tcloacal, °C) of the broilers was evaluated. The study was carried out in Lavras, Minas Gerais, Brazil. A total of 720 Cobb-500 broilers were raised from 1 to 42 days old. When the broilers were 7, 21, 35 and 42 days old, the dry bulb temperature (tdb, °C) and relative air humidity (RH, %) were recorded at 08:00 a.m. and 01:00 p.m. by seven sensors distributed throughout the installation, and tcloacal measured. Subsequently, h computed, and the data were examined through kriging interpolation. The tcloacal data were superimposed on the h maps of the facility. The spatial distribution of h inside the aviary (box) and temporal distribution (time and days) were characterized, and its variability was visualized. Tcloacal was directly related to the spatial as well temporal distribution of h, providing information about the thermal influence on production environment and the physiological responses of broilers.
Multi-criteria decision analysis of wood waste ash and glass foam: toward sustainable material selection for biomethanation
(Estonian University of Life Sciences, 2024) Kusnere, Z.; Lauka, D.; Spalvins, K.
The study examines the potential applications of wood waste ash and waste glass, byproducts of various industrial processes, which have conventional applications such as composting and soil improvement. A new development, vulcanised wood ash material, is studied analysed, drawing parallels between its industrial production process and that of clay pellets. Vulcanised wood ash material and glass foam, which are characterised by advantageous chemical and physical properties, are proving to be versatile resources for various technical applications. Employing a systematic decision-making approach, the study utilises multi-criteria decision analysis and the Technique for Order of Preference by Similarity to Ideal Solution method to evaluate materials for biotrickling filter reactors in ex-situ biomethanation. The comparative analysis includes ash filter material, glass foam, and other industry alternatives, emphasising environmental impacts. The findings reveal expanded clay pellets as the most suitable carrier material, closely followed by polyurethane foam, while glass foam demonstrates remarkable performance despite ranking third. The innovative qualities of glass foam, such as high porosity and thermal insulation, position it as a viable option for biotrickling filter reactors, promoting sustainable practices and circular economy principles. However, further development is required to optimise vulcanised wood ash for biomethanation, potentially enhancing its efficiency through pH adjustment and porosity optimisation.
Effect of fermented purple sweet potato flour on physiological conditions and intestinal conditions of broiler chickens
(Estonian University of Life Sciences, 2024) Widiastuti, E.; Febrianti, D.; Wahyuni, H.I.; Yudiarti, T.; Agusetyaningsih, I.; Murwani, R.; Sartono, T.A.; Sugiharto, S.
The study investigated the effect of fermented purple sweet potato flour (PSPF) on intestinal and physiological health of broilers. A 189-day-old broiler chicks were divided into T0 (diet based on corn and soybean meal), T1 (diet containing 15% unfermented PSPF), and T2 (diet containing 15% fermented PSPF). Samples collection and measurement were conducted at day 35. The T2 chicks had greater (p < 0.05) weight gain than T1, but did not differ from T0. Feed conversion ratio (FCR) was better (p < 0.05) in T2 than in T1. The mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were higher (P < 0.05) in T2 than in T0 and T1 groups. Haemoglobin tended (p = 0.08) to be lower in in T2 than in T0 and T1 groups. Heterophils were higher (p = 0.05) in T2 than in T0 and T1 groups. Total cholesterol and high-density lipoprotein (HDL) were higher (p < 0.05) in T0 than in T1. Low-density lipoprotein (LDL) tended (p = 0.06) to be lower in T1 than that in T0. Total protein and globulin were higher (p < 0.05) in T0 than that in T1 and T2. Lactic acid bacteria (LAB) to coliform ratio in the ileum was higher (p < 0.05) in T2 than in T0. LAB counts tended (p = 0.08) to be greater in T2 than in other chickens. T1 tended (p = 0.09) to have a smaller number of lactose negative Enterobacteriaceae (LNE) in caecum as compared to that of T0 chicks. T2 tended (p = 0.09) to have a lower crypt depth than T0. In conclusion, feeding fermented purple sweet potato flour contributes for the better growth, feed conversion, immune defence, bacterial population and morphology of the small intestine.
Influence of the pyrogenic impact upon the state of soil microbiocenosis of eight- and twenty-years old fallows (lea lands)
(Estonian University of Life Sciences, 2024) Kaminskyi, V.; Malynovska, I.; Bulgakov, V.; Balian, A.; Olt, Jüri; Rucins, A.; Estonian University of Life Sciences. Institute of Forestry and Engineering
The restoration dynamics of the biological activity of soils after fires of various intensity is an urgent problem. Pyrogenic effects (fires) affect the state of microscopic soil inhabitants: bacteria, micromycetes, etc., causing their death and reducing their physiological and biochemical activity. From a theoretical and practical points of view it is important to study changes in the community of the soil microorganisms during the restoration of phytocenoses in the post-pyrogenic areas. Investigations of Albebeluvisoil were carried out as an example in geographically close areas: 1 and 2 – soil, withdrawn from agricultural use in 1987 (twenty-yearsold fallow); 3 and 4 – soil, withdrawn from agricultural use in 2000 (eight-years old fallow. Studies of the state of the post-pyrogenic and background sections of the eight-year-old and twenty-year-old fallows showed that the mechanism of the effect of fire upon the soil microbiocenosis differs 3 and 14 months after it took place. After the fire during a three-month period there are general processes that lead to a decrease in the number of unicellular living organisms, which also lose their physiological and biochemical activity, there is an increase in mineralization, based on compounds of elements such as carbon and nitrogen. The exception is humus. There is also an increase in soil phytotoxicity of soil. The conducted researches have established that after 14 months the processes of active decomposition of humus begin to decrease and in general the phytotoxicity of soil decreases. There are also observed processes of increase in the number of single-celled living organisms on the basis of nitrogen and phosphorus. After 26 months the consequences of the fire are minimized: the difference in the number of microorganisms and their physiological and biochemical activity becomes statistically unreliable, with the exception of micromycetes, mobilizers of mineral and organophosphates, nitrifying and denitrifying microorganisms; the difference in total biological activity is reduced from 12.6 to 8.67%, in phytotoxicity - from 16.0 to 2.89%.
Does the level of resistance to Acanthoscelides obtectus of bean genotypes (Phaseolus spp.) change according to the seed production environment?
(Estonian University of Life Sciences, 2024) Jiménez-Galindo, J.C.; Castellanos Pérez, G.; de la Fuente, M.; Malvar, R.A.; Ramírez-Cabral, N.; Padilla Chacón, D.
Bean weevil (Acanthoscelides obtectus) cause considerable losses in warehouses in dry bean (Phaseolus vulgaris L). Phaseolus acutifolius varieties could be used for genetic studies and genetic improvement of common beans. Tepary bean varieties resistance was studied produced with irrigation and under drought conditions to A. obtectus. Previously, we studied A. obtectus colony from Spain with some of these bean varieties. In the present research, we studied a different A. obtectus colony from México. The varieties T-amarillo, PS-AZH-15 and T-cafe beans showed a lower ovopositation. T-amarillo, T-negro and T-cafe increased the duration of the insect biological cycle. In the varieties T-cafe, T-negro and T-amarillo increased larvae mortality before burrowing the seed in percent and reduced the number of first generation adults. Little grain weight loss is caused by small number of emerged adults, in the varieties T-amarillo, PS-AZH-15, T-cafe and T-negro. According with adult’s number of first generation and grain weight loss in percent T-amarillo showed resistance and tolerance to A. obtectus infestation and it could be used as source of resistance for P. vulgaris breeding. No significant differences were found according to the seed production environment for any traits studied except for initial seed weight. Resistant varieties maintain their lethality regardless of the seed production environment. Probably A. obtectus is genetically different according to the area and is adapted to the varieties produced in each country or region.
Psychosocial risks for health care workers in rehabilitation centre
(Estonian University of Life Sciences, 2024) Kalkis, H.; Roja, Z.; Metuma, V.
Psychosocial risks at work have a strong impact on workers in every economic field, especially in health care. The aim of this study was to analyze psychosocial risk impact on workers in 3 areas of work, including doctors or functional specialists, nurses and support staff at work for healthcare employees in one of Rehabilitation centers in Latvia. The Copenhagen Psychosocial Questionnaire was used to assess psychosocial risks at work. Main results show that the high scores for work atmosphere and social support from colleagues reflect the favourable social environment in the context of employee relationships, but doctors and functional specialists face significant psychosocial risks characterized by high quantitative and emotional demands, compounded by job insecurity and inadequate managerial support. Nurses contend with high physical and emotional risks influenced by unpredictable work patterns, unclear roles, and insufficient social support, while support staff confront high workload, role conflicts, and pervasive job insecurity, minimal recognition and unsupportive workplace atmospheres. In general critical aspects include work-life balance, appreciation and self-rated health are at work. Continuation of the research will be related to investigating the psychosocial risks with cognitive tests for each research group.
Genotype prediction in maize (Zea mays L.) progeny using different predictive models
(Estonian University of Life Sciences, 2024) Polyvanyi, A.; Butenko, A.; Mikulina, M.; Zubko, V.; Kharchenko, S.; Dubovyk, V.; Dubovyk, O.; Sarzhanov, B.
This study utilized two probabilistic methods, Gaussian Naive Bayes (GNB) and Logistic Regression (LR), to predict the genotypes of the offspring of two maize varieties: SC604 and KSC707, based on the phenotypic traits of the parent plant. The predictive performance of both models was evaluated by measuring their overall accuracy and calculating the area under receiver operating characteristic curve (AUC). The overall accuracy of both models ranged from 80% to 89%. The AUC values for the LR models were 0.88 or higher, while the GNB models had AUC values of 0.83 or higher. These results indicated that both models were successful in predicting the genetic makeup of the progeny. Furthermore, it was observed that both models were more accurate in predicting the SC604 genotype, which was found to be more consistent and predictable compared to the KSC707 genotype. A chi-square test was conducted to assess the similarity between the prediction results of the two models, revealing that both models had a similarly high likelihood of making accurate predictions in all scenarios.
Advancing circular bioeconomy: trends, clusters, and roadmaps in biofuel production and waste valorisation
(Estonian University of Life Sciences, 2024) Chernysh, Y.; Chubur, V.; Roubik, H.
Today, one of the important tasks of bioeconomy development is waste management based on the principles of environmental management and bioenergy production. In the context of this issue, this review focusses on the analysis of current trends in biofuel production that involve sustainable feedstocks and the valorisation of waste into useful bioproducts in agriculture. The scientometric method included the use of Scopus and Web of Science databases to compare the coverage of the research topic with keyword chain optimization. In addition, bioinformational databases was used to support the involvement of secondary raw materials in the bioprocessing cycle. The implementation of the research objectives resulted in the identification of bioeconomy clusters that emphasize the importance of developing specific regional circular bioeconomy strategies while avoiding ‘one-size-fits-all’ solutions for individual sectoral technologies. An example of bioeconomy development in the world is bioenergy. The structure of bioenergy has been analysed. A roadmap for biotechnology modernisation was proposed using the example of anaerobic waste conversion process as part of the implementation of a circular bioeconomy. The stages of the roadmap for the modernisation of bioenergy technologies were analysed within the framework of the sectoral implementation of the circular bioeconomy. The efficiency indicators for the implementation of bioeconomy in agricultural production have been determined. In addition, an important direction unifying anaerobic technologies with the agricultural sector is the enrichment of digestates with macro and microelements, which is possible due to mineral additives, for example, phosphogypsum. This direction was also considered from the point of view of environmental safety.
Influence of coconut fiber incorporation on the mechanical behavior of adobe blocks
(Estonian University of Life Sciences, 2024) da Silva, N.A.; Cecchin, D.; Rocha, C.A.A.; Toledo Filho, R.D.; Pessin, J.; Rossi, G.; Bambi, G.; Conti, L.; Ferraz, P.F.P.
Adobe is an ancient construction technique, simple and low cost, still used in some parts of the world, mainly in rural areas. Normally, in these regions, a considerable amount of agricultural waste is generated that can be used for different purposes. An agricultural waste that has been increasingly studied in the construction sector is natural fibers. The addition of natural fibers in the soil matrix has been gaining prominence as it is a natural and easily accessible stabilizer. This work aimed to analyze and characterize adobe blocks reinforced with coconut fibers, with the addition of 1% and 2% compared to the reference block (without the addition of coconut fiber) through capillary absorption, fiber-soil adhesion, durability in the presence of water and mechanical, properties through of compression bending tests. The adobe blocks with the addition of fibers showed mechanical results above those required by the standard NBR 16814. The addition of fibers promoted higher capillary absorption results than the samples consisting only of soil and when exposed to drip erosion, no significant damage was observed in the adobe structure.
Exposure to job related risk factors and work-related musculoskeletal disorders among medical laboratory workers
(Estonian University of Life Sciences, 2024) Vahur, Kristi; Parm, Ülle; Merisalu, Eda; Estonian University of Life Sciences. Institute of Forestry and Engineering. Chair of Biosystems Engineering
Work-related musculoskeletal disorders (WRMSDs) are the most common work-related diseases among health care workers including medical laboratory workers (MLW). Laboratory workers, when performing different work tasks, are exposed to repetitive movements, static and uncomfortable forced positions. The aim of this study was to explain the occurrence of WRMSDs among medical laboratory workers in relation to job related risk factors, tools and equipment, when performing specific work tasks. Material and methods: The study involved the Estonian MLWs from three regional and four central hospitals. The criteria of the study group were experience ≥ 1 year and workload ≥ 0.5 staff. The e-questionnaire was sent to 502 laboratory workers. Results: The response rate was 25.1%. To the questionnaire answered 126 MLWs, whereas the sample criteria met 122 respondents. There was significant association between nature of the work and shoulder pain in past month and 12 months among MLWs (p < 0.05). The most affected body regions were low back and neck. Work tasks which involved repetitive movements and forced position more than 1 hour were related to pain in low back, neck, and shoulders (in all cases p < 0.05). Those who worked in sitting posture, reported less neck pain both in the past and 12 months, compared to the workers who worked in both sitting and standing posture (p < 0.05, p < 0.01). Conclusions: MLW are at high risk of WRMSDs. So, improvement of workplace ergonomics and rising risk awareness are very important interventions among MLWs.
Production of simple sugars from olive grove pruning using acid pretreatment and enzymatic hydrolysis
(Estonian University of Life Sciences, 2024) Pedro, N.; Bezerra, R.; Fraga, I.; Duarte, A.P.
The purpose of this paper was to optimize the production of simple sugars from olive grove pruning (OGP) using acid pretreatment and enzymatic hydrolysis. This study was based on a model composition corresponding to a 34 orthogonal factorial design and employed the response surface methodology (RSM) to optimize the pretreatment and hydrolysis conditions, aiming to attain maximum glucose, xylose and arabinose extraction from cellulose and hemicellulose of biomass. The pretreatment operating conditions considered for optimization, were temperature (60–180 °C), residence time (30–120 min) and sulphuric acid concentration (0.5–5% w w-1). Enzymatic hydrolysis experiments on solid fraction pretreated with diluted acid were performed at a solid concentration of 5% (w v-1, based on dry weight), using 50 mM citrate buffer pH 4.8 with BSA at a concentration of 60 mg g-1 dry biomass. The reaction mixture was incubated at 50 °C for 174 h on an orbital shaker at 150 rpm. Three commercial enzyme preparations (cellulase complex, b-glucosidase and xylanase) were used in enzymatic saccharification. Total carbohydrate content of the initial biomass was 51.25% (in dry mass), of which glucose was the major constituent with 33.59%. Contents of lignin and extractable found in biomass were 24.96% and 15.84%, respectively. In this work, it was possible to extract 93.1% of the sugars present in the olive grove pruning, with pretreatments carried out for 102 min at 156 °C with a sulfuric acid load of 4.09% (w w-1), followed by enzymatic hydrolysis performed for 174 h, with an enzyme loading of 18 PFU, 36 p-NPGU and 36 IU per gram of substrate.
Herbicide-based selection of mutants for improved single cell protein synthesis: application and procedures
(Estonian University of Life Sciences, 2024) Raita, S.; Berzina, I.; Kusnere, Z.; Kalnins, M.; Kuzmika, I.; Spalvins, K.
Enhancement of industrially important microbial strains using random mutagenesis is widely used. Screening of potential mutants accelerates the selection of mutants with desired properties such as improved synthesis of lipids, carotenoids, enzymes, or increased tolerance to unfavourable conditions. However, random mutagenesis has not been used to improve protein biosynthesis in microorganisms, and a method for screening these mutants has not yet been developed. The present work reviews the new concept of using herbicides as tools for selecting mutant microorganisms with improved protein biosynthesis. Several pure herbicide substances are amino acid inhibitors whose specific action can be used as a selective pressure for screening protein-rich mutants. The article summarises information about thirteen amino acid inhibitors that inhibit microorganisms and provides data on applicable doses and specifics of use. The article contains mutagenesis protocols and mutant selection strategies, supplemented by theoretical considerations for practical application.
Influence of weather conditions on winter wheat (Triticum aestivum L.) overwintering
(Estonian University of Life Sciences, 2024) Polishchuk, V.; Konovalov, D.; Brovdi, А.
The aim of the study was to determine the effect of hydrothermal conditions, duration of winter and varietal characteristics on the sugar content in tillering nodes and, accordingly, on wintering of м plants in the Right-Bank Forest-Steppe of Ukraine. The direct dependence of the amount of sugars in the tillering nodes of winter wheat (Triticum aestivum L.) on the sum of effective temperatures and the duration of autumn vegetation was established. It was found that under the most favorable conditions prevailing in the autumn growing season of 2019, with the sum of effective temperatures of 984.6 °C and the duration of the autumn growing season of 76 days, the amount of accumulated sugars was 4.7% higher compared to 2016, and was 30.6%. It was found that over the years of research, the sugar content in the tillering nodes of winter wheat (Triticum aestivum L.) was higher in mid-season varieties, but there was no significant difference in varieties within the same maturity group, which confirms the high adaptability of the studied varieties to the soil and climatic conditions of the Right-Bank Forest-Steppe of Ukraine. Favorable climatic conditions in autumn and winter over the years of observation ensured good growth and development of plants in the pre-winter period and contributed to the accumulation of optimal amounts of sugars in tillering nodes, which ensured high winter survival of plants of all winter wheat (Triticum aestivum L.) varieties. The lowest percentage of overwintering was observed in Gorodnitsa variety at 98.8%, and the highest in Astarta variety with an average of 99.8% over the years of research.
Analysis of the relationship between the weather index of fire danger and occurrences of rural fires. Case study: centro region of Portugal
(Estonian University of Life Sciences, 2024) Fernandez, P.; Bugalho, L.; Pedro, N.
The aim of this study was to design an approach for establishing a plausible relationship between FWI and the monthly average burned area (ABA) and the average number of ignitions (ANI) supported by geographic information systems (GIS). The application of these results will allow the projection of burned areas in forest fires in the future, making mitigation actions possible. This approach was applied to the region of Central Portugal, and to achieve the aims of the study, the following steps were completed: (1) geoprocessing the spatial data of the daily FWI indices, burned area and number of fire ignitions and (2) developing statistical regression models capable of reproducing the variability in burned area and ignition occurrence series from FWI data during the 2001–2017 period. The predicted equations for the burned area as a function of the FWI presented high coefficients of determination for most of the considered periods, thus allowing the projection, with a high degree of confidence, of the monthly burned area values according to the various future climate scenarios. The prediction of the average number of ignitions from the FWI values class proved to be effective for establishing highly adjusted forecast models for July and August. In the spatial analysis at the district level, the ABA and ANI estimation equations were obtained from the FWI values with determination coefficients above 0.90 for most of the districts. Significant differences were observed between the districts in the number of ignitions analysed.

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