Growth Production Research Articles

Selected Physical and Mechanical Properties of Particleboards Manufactured from Plantation Willow and Poplar Wood.

This research focuses on producing particleboards from the biomass of plantation willow (Salix viminalis L.) and poplar (Populus spp.), aiming to explore their feasibility as sustainable materials for various applications. Fast-growing willow and poplar are known for their rapid growth and suitability for energy production. They present an intriguing alternative as raw materials with added value for particleboard manufacturing. This study investigates the selected mechanical and physical properties of the produced particleboards, considering parameters such as density profile, bending strength, modulus of elasticity, internal bond, water absorption, thickness swelling, and screw withdrawal resistance. The research results were also compared between different mass shares of willow and poplar particles in the particleboards. The results show that the panels produced entirely from the tested alternative raw materials had a modulus of rupture of 21.7 N mm-2 compared to 14.6 N mm-2 for the reference panels, with an internal bond of about 2.02 N mm-2 compared to 0.65 N mm-2 for the reference panels. The thickness swelling after 24 h of soaking was about 24.2% compared to 42.2% for reference panels. The findings underscore the promising potential of willow and poplar-based particleboards as eco-friendly alternatives in the construction and furniture industries, contributing to resource efficiency and carbon emission reduction efforts.

Influence of crop development and fruit retention on the timing of crop maturity in Ultra-narrow row cotton

Ultra-narrow row (UNR) cotton, a production system with rows spaced less than 40 cm apart, has been proposed as a system for earlier maturity without substantial yield loss. However, trials in the U.S.A. and Australia have found maturity benefits difficult to achieve consistently. Studies undertaken in high input cotton systems that compared UNR to conventionally (1 m) spaced cotton found yield differences but failed to demonstrate differences in crop maturity. This paper examines crop development and fruiting dynamics of the two systems in more detail to understand why there were no differences in maturity. Results showed that lack of difference in maturity between the row spacings was not influenced by differences in the time to reach crop development stages nor by lower fruit retention of early bolls in the UNR plants. Node production and fruiting site production on a per plant basis were significantly slower in the UNR plants from early in the growing season. Slower node and fruiting site production delayed maturity in the UNR plants as they set fewer fruit within the same period of time compared to plants grown in conventional spaced rows. The number of fruiting sites produced per plant was highly dependent on the amount of dry matter per plant. Fruiting site production was reduced in the UNR crop because each plant produced less total dry matter, and hence plant development was slower. To further help understand the reasons for outcomes generated in these studies, and how UNR could possibly mature earlier without impacting yield, a conceptual modelling framework was developed to integrate seasonal patterns in fruiting site production, retention, and boll growth. A key component of this framework is translating from a per plant basis to an area basis. The analysis showed that for individual UNR plants to mature earlier and maintain yield on an area basis, early node production and fruiting site production must proceed at a similar rate to conventionally spaced crops. In this scenario 90 % of final yield would be present 14 days earlier in the UNR crop compared to conventionally spaced crops. To realise any benefits of potential earlier maturity further research is needed to explore genetic or management interventions that might avoid the early competitive stress response that slows node development in UNR.

KEY ASPECTS OF ECONOMIC SECURITY OF THE RUSSIAN REGION (CASE OF LIPETSK REGION)

The article is devoted to the issues of economic security of the Russian region using the example of the Lipetsk region. The study updates the role of regional economic security based on an in-depth analysis of the theoretical concepts of scientists over the past 20 years. Based on the works of the Russian economist S. Y. Glazyev, in which he uses his author’s, integral approaches to indicators of reproduction of human and economic potential, researchers assess the state of economic security in the Lipetsk region. The authors conclude that the main trend at the moment is the “forced” growth of production, not provided with sufficient labor resources for the future, accompanied by low socio-­economic indicators of reproduction. Having sufficiently advantageous geographical, climatic and natural resources, the Lipetsk region does not have a high development potential at this point in time due to the low level of self-awareness of the population. The level of crime, alcoholism or fertility is often not related to the economic standard of living of the population, but rather depends on the level of development of the individual and society. The lack of capital investments in fixed assets for the future shows the lack of strategic goals of producers and the desire to obtain short-term benefits. The authors see the development of patriotic, spiritual and moral education as one of the directions for improving the indicators of reproduction of human and economic potential in the region.

Job losses or gains? The impact of supply-side energy transition on employment in China

The supply-side energy transition has created numerous jobs in the renewable energy industry while also destroying jobs in the traditional industry. This study examines the relationship between the supply-side energy transition and employment using panel data from China covering 2008 to 2022. It includes a heterogeneity analysis based on geographical location, economic development, and resource endowments, and estimates net employment based on clean energy production projections. Results show that a 1 % growth in clean energy production led to an approximately 0.013 % increase in total employment. However, that effect was heterogeneous. Employment in the primary industry decreased while the tertiary industry saw an increase. Geographically, employment rose in East and South China but fell in Middle China. Economically, lower-income areas benefited more, which could help reduce talent inequality. Regarding resource endowments, job losses were notable in coal-rich areas and indicated the need for fair transition. Conversely, wind and solar-rich regions experienced higher employment growth, showing a scale effect of clean energy development. By 2060, net employment is projected to increase by 5.89–9.96 million. Policies should be tailored to specific local circumstances in order to also promote a fair, equitable energy transition.

Modeling a High-Energy, High-Rate Li/CFx Battery with a Capacity-Contributing Electrolyte

The Li/CFx primary cell has the highest specific energy of any commercialized cell, but recent funding programs (e.g., the IARPA RESILIENCE program) seek significant increases in performance beyond that achieved with current cell formulations, including both higher average rates than are typical for Li/CFx (e.g., C/3 for the RESILIENCE program) and high-rate pulses (e.g., 5C/3, also for the RESILIENCE program).1 One method to raise the specific energy beyond that of current commercial cells is to also obtain capacity from the electrolyte (i.e., to use a capacity-contributing electrolyte).2,3 This should occur after the CFx has been mostly consumed. The present talk will briefly introduce experimental results demonstrating the operation of a capacity-contributing electrolyte in a Li/CFx cell, and then focus on our 0-D modeling framework that includes three reactants (CFx, salt, and solvent), a cathode that undergoes volume expansion during discharge (based on the molar volumes of the reactants and products), and the growth of resistive electrolyte products.4 Our base case cell design is for a ~750 Wh/kg cell. We demonstrate the behavior of our model formulation for a C/3 average rate with two 5C/3 one-minute pulses (one at 99% and one at 20% SOC, based on the capacity of the CFx and capacity-contributing electrolyte). We find that there is significant cathode swell during discharge (i.e., 10s of %) that affects the cell polarization, and the electrochemical behavior of the 20% SOC pulse is highly dependent on the thermodynamics, kinetics, and transport properties of the salt and solvent reactants and products. Our modeling framework can be applied to additional chemistries with multiple active materials, significant electrode thickness changes, and resistive electrolyte products.1. https://www.iarpa.gov/research-programs/resilience2. J. Am. Chem. Soc. 2014, 136, 19, 6874–68773. Adv. Mater., 2015, 27, 3473–34834. Journal of The Electrochemical Society, 158 (5) A504-A510 (2011)

(Invited) The Evolving SiC Market and Impact on CMP Supply Chain

Silicon carbide (SiC) is a wide bandgap semiconductor with physical and electrical properties that provide superior performance in high-voltage or high-power applications. Compared to the more established silicon devices, SiC provides better thermal conductivity, ~10x higher breakdown voltage, faster switching speeds and lower resistivity. Even with the performance advantages, the adoption rate of SiC is slowed by high cost and the inherent difficulty of processing this material. SiC is extremely hard (just below diamond on the hardness scale) and chemically inert which makes processing boules into wafers rather difficult. This presentation will contrast some of the basic differences between process methods developed for silicon and other semiconductor materials versus those required for SiC.Demand for high-quality single crystal SiC substrates continues to rise as the worldwide demand for electric vehicles, charging infrastructure, green energy production, and more efficient power devices in general requires more and more SiC devices. SiC wafer manufacturers are trying to ramp output as quickly as possible but technical difficulties of processing SiC are often a limiting factor. In spite of aggressive capital spending by many of the major players, the actual growth in substrate production has been constrained to around 15% CAGR even though demand would support a much faster ramp. As end use markets continue to evolve, ripple effects are also evident in the underlying supply chains, such as CMP pads and slurries.

(Invited) Efficient Recycling of Dilute Nitrate to Ammonia Using Cu-Based Electrocatalyst

The use of nitrogen fertilizers has contributed significantly to the growth of agricultural production, but the nitrogen use efficiency is typically lower than 40%, so most of the nitrogen readily leaches into ground water, rivers, and lakes, causing an increase of nitrate (NO3 −) concentration and severe environmental problems. Electrochemical reduction of nitrate has emerged as a promising route for the recycling of nitrate from wastewater and sustainable production of ammonia when powered by renewable electricity. Here I present our recent studies of the intrinsic activity and selectivity of Cu for nitrate electroreduction, as well as a rational design of Cu-based catalysts for single-pass conversion of nitrate to ammonia. Using polycrystalline Cu foils for benchmarking, we elucidated the impact of often overlooked factors on nitrate reduction, including Cu facet exposure, nitrate concentration, and electrode surface area. We find that an electropolished Cu foil exhibits a higher activity and selectivity for nitrate reduction to ammonia than a wet-etched Cu foil, benefiting from a greater exposure of Cu(100) facets that are more favorable for the reaction. The NH3 selectivity shows no apparent dependence on the nitrate concentration, but it increases monotonically with Cu electrode area, which is attributed to a promoted conversion of intermediately produced NO2 − to NH3 on a larger electrode. Based on the understandings, we further developed a Cu/Co-based tandem electrocatalyst, which achieved nearly 100% single-pass conversion of dilute nitrate (5−50 mM) to NH3 at a low overpotential using a flow cell.

In-situ observation and directional growth of Ca2Lu8(SiO4)6O2 in Lu2SiO5 attacked by CMAS at 1500 °C

Excellent resistance to CMAS is one of the key parameters for environmental barrier coating (EBC) operated in gas turbine engines. The interaction between CMAS and EBC was usually investigated by the characterization of reaction products after corrosion. The lack of direct observation of the high-temperature CMAS corrosion processes hinders the understanding of CMAS-induced degradation of EBC. In this work, the interaction between CMAS and an EBC candidate (Lu2SiO5) was investigated by an in-situ observation method, where the melting of CMAS and the growth of reaction products were first observed. It was found that the reaction product Ca2Lu8(SiO4)6O2 tends to precipitate vertically to form a textured structure. In addition, Lu2SiO5 tends to decompose into Lu2Si2O7 and Lu2O3 at 1500 °C, which induces an intergranular infiltration of CMAS and leads to the formation of Ca2Lu8(SiO4)6O2 fringes. Compared with the corrosion behavior at 1300 °C, Lu2SiO5 exhibits fast interaction with CMAS and poor CMAS resistance at 1500 °C. The results provide important guidelines on the design of rare earth silicate EBC.

Market participation as livelihood and safeguarding intangible cultural heritage: A case of Chăm ethnic minority pottery households in Vietnam

This study examines the extent of market participation among Chăm pottery producers in Vietnam and the factors that influence this extent. The research utilized the total market participation index to assess the level of market participation and Tobit regression to examine the factors influencing market participation. Primary data were collected from a sample of 150 pottery households. The study demonstrates that pottery households are involved in the market to varying degrees. Factors such as family size, hired labourers, production space, self-owned transportation, average distance to customers, amount of advertising, and credit accessibility positively affect their participation in the market. Shipping damage, government assistance, non-pottery income, and education level of household head have a negative effect. The findings indicate that government assistance should consider the requirements of pottery households to develop efficient support measures. The research serves as a useful reference for policymakers and managers in devising strategies to promote both the growth of traditional craft production and the sustained well-being of ethnic groups. This, in turn, would contribute to the overall economic advancement of the country.

მეწარმეობის განვითარების თანამედროვე მიდგომები და პერსპექტიული გამოწვევები

Entrepreneurship is one of the essential and priority directions in today's world, especially in market economy conditions. The agricultural industry is the most essential element in the development of the economy; it also has a special mission and role of providing food for society. The agricultural sector, especially small and medium enterprises, has a special role and importance in the country's economy. It creates new opportunities, resources, and wealth, increases jobs, improves the economy, develops the capital market, and makes a special contribution to the economic well-being of society and the sustainable development of the economy. Therefore, entrepreneurship development can be considered a stimulating lever of the economy. Modern approaches to entrepreneurship and practical challenges are classified in many directions. However, I would single out technological, automated, and artificial intelligence, which in modern conditions can be compared to a new revolution, which has already had its economic and business effect on the development of the entrepreneurship sector. With its potential, entrepreneurship greatly contributes to the development of the country's inclusive economy, which can be considered the cornerstone of any country's success. The development of the entrepreneurship sector particularly contributes to the volume of production growth, export, creation of international industry culture, innovation, integration with globalization and plays an important role in the growth of the social and economic level of the country. Business entities operating in the conditions of modern development and beginning small- and medium-level entrepreneurs talk about the issues of maintaining a business that has never been as difficult as they are today. Disruptions caused by technology, a saturated market, and companies of multinational origin always trying to swallow any expected sign of new competition, giving new entrepreneurs no opportunity to start and develop. There are many modern challenges of entrepreneurship, but I will highlight the most important ones. These are insufficient capital, attracting financial resources for development, effective time management, market research, ineffective marketing, lack of qualified staff, team, customer loyalty, defensive mechanisms, lack of financial management, and impact of globalization. Today, the agrarian sector is relevant, and many economists, scientists, and publicists investigate the modern practical challenges of this issue. Therefore, we think it will be very interesting to have a theoretical-methodological and synthetic discussion in the face of the modern challenges of entrepreneurship. Statistics from many countries show an alarming rate of SME enterprise failure. For example, about two-thirds of new businesses in the United States do not survive five to ten years. In Australia, 96.8 percent of small businesses either go out of business or grow very little within the first five years of starting. Entrepreneurship development is increasingly becoming a major concern globally. The paper will discuss the essence and importance of entrepreneurship, its forms and types, modern approaches to its development, challenges, and overcoming perspectives. We will also discuss the current state of the Georgian entrepreneurship sector and offer recommendations that can be adapted to the best-developed countries in the world, which will help the entrepreneurship sector define conceptual aspects.

Energy-saving scheduling strategy for variable-speed flexible job-shop problem considering operation-dependent energy consumption

The rapid growth of industrial production signifies its CO2 footprint and climate impact, highlighting the demand for efficient and energy-saving production scheduling. Generally, a single production job comprises multiple operations on various machines. Existing studies estimate job energy consumption from a broader perspective, often disregarding the detailed scheduling of operations. This simplification may result in inaccurate evaluations of energy consumption and savings, as energy consumption can differ significantly among operations, with each requiring specific levels of energy on various machines. Proposing a new scheduling framework to replace the classical strategy is challenging yet necessary due to these variations. This study aims to investigate the multiobjective flexible job-shop scheduling problem by considering operation-dependent energy consumption and to improve the accuracy and thoroughness of the energy-consumption evaluation framework. First, a core metamodel for energy assessment is established and a mathematical model is introduced to minimize the manufacturing span and total energy consumption. Subsequently, a dynamic diffusion weight adjustment for a multiobjective evolutionary algorithm based on decomposition (MOEA/D-DDWA) is proposed. Operation-dependent energy consumption and processing quality are discussed, and a superior unified energy-saving strategy is designed to facilitate the selection of the processing-speed range, balancing energy consumption and saving. Finally, numerical experiments are conducted based on datasets of various scales, demonstrating that the core metamodel for energy assessment can achieve significant energy savings. Compared with other classical multiobjective optimization algorithms, the MOEA/D-DDWA is more energy efficient.

Statistical optimization, kinetic modeling, and techno-economic analysis for the production of high molecular mass dextran using sugarcane industrial waste-molasses

This study focuses on the transformation of industrial wastes to wealth by utilizing treated sugarcane molasses (TCM) to produce dextran. The fermentation conditions for maximum dextran production were initially optimized using central-composite design in shake-flasks. The highest titer of dextran (60.0 ± 2.0 g/L) was obtained with optimized variables of 150 g/L substrate (TCM), 12.8 g/L yeast extract, 39.8 g/L K2HPO4, and 48 h fermentation time. Then, the profiles of dextran production, TCM consumption, and microbial growth were fitted by kinetic models to obtain the following kinetic parameters: 0.35 h−1 maximum specific growth rate (μmax), 0.48 g dextran/g substrate yield coefficient (Yps), 0.07 maintenance coefficient (ms), and 10.73 g product/g cell growth-associated constant (α). For determining the scale-up factors, the fermentation conditions were replicated in a 3 L fermenter at various stirring speeds (50–250 rpm), and a scale-up strategy based on constant P/V was used to predict the power consumption (1.88–285.51 W) for a pilot-scale of 2000 L working volume fermenter at various stirring speeds (10.8–54 rpm). The dextran produced was characterized using gel permeation chromatography to determine the molecular mass variations (3–4000 kDa) with fermentation conditions. The rheological variations of fermentation broth at different stirring speeds were also studied and related to the molecular mass of the dextran produced. Techno-economic analysis for dextran production explored a gross margin of 22.65 %, a return on investment of 16.80 %, and a pay-back time of 5.95 years.

Fluctuations oil prices in the world and their impact on Indonesian macroeconomics

Abstract Changes in international crude oil prices can significantly impact economic outcomes. This study tested the impact of oil price fluctuations on macroeconomic variables in Indonesia. The data used is annual data from 1990 to 2021 with the specific purpose of solving the current research deficiency about swings in oil prices. study adds five macroeconomic variables as explanatory factors to accomplish this purpose. We use five macroeconomic variables: economic growth, inflation, interest rates, industrial production, and exchange rates. The impact of oil price fluctuations on GDP, inflation, exchange rates, interest rates, and industrial production indices in Indonesia is examined within a structural vector autoregressive (SVAR) framework. Research shows that oil price shocks significantly impact GDP, inflation, and exchange rate. The results also show that oil price shocks hurt two other variables: the interest rate variable and the industrial production index. The findings derived from the analysis of the impulse response function indicate a detrimental effect on the growth of production, while exerting a favourable influence on inflation. However, the impact on industrial production, interest rates, and exchange rates is very modest and characterised by a degree of uncertainty.

Production Responses of Multiparous Dairy Cattle with Differing Prepartum Muscle Reserves and Supplementation of Branched-Chain Volatile Fatty Acids

Periparturient dairy cattle undergo physiological adaptations to support fetal growth and colostrum synthesis in late gestation and milk production in early lactation. To support energy and protein demands dairy cattle mobilize body tissue reserves. The objective of this study was to determine the effects of prepartum skeletal muscle reserves and supplementation of branched-chain volatile fatty acids (BCVFA) on body composition measurements, metabolic markers related to health, protein, and energy status, and subsequent milk yield in multiparous dairy cows. Skeletal muscle reserves were assessed by 3 ultrasounds of the longissimus dorsi muscle depth (LDD) measured 42 d before expected calving (BEC), and cows (n = 48) were assigned to either high muscle (HM; > 4.6 cm) or low muscle (LM; ≤ 4.6 cm) groups. Cows were then randomly assigned to either control (CON) of soyhull pellets (80 g/d) or BCVFA treatment which contained isobutyrate (40 g/d), isovalerate (20 g/d), and 2-methylbutyrate (20 g/d) calcium salt products. Treatments were top dressed from 42 BEC until parturition, resulting in 4 combinations of muscle groups and treatments: HM-CON (n = 13), HM-BCVFA (n = 13), LM-CON (n = 11), and LM-BCVFA (n = 11). Measurements of the LDD, BW, and BCS were taken on the following days relative to calving -42, -35, -21, -7, 0, 7, 14, 21, 28. Weekly blood samples were taken to measure glucose, BHB, and insulin concentrations, and 5 of the blood sample time points were utilized to determine 3-methylhistidine and creatinine blood concentrations. Milk yield was recorded daily for the first 28 d of lactation, and samples were taken from both milkings once a wk for the first 4 wk to determine components. The statistical model included the fixed effects of treatment, group, time, their interactions, and the random effect of cow nested within group and treatment. Prepartum muscle mobilization varied between muscle groups, as LM cows accreted muscle prepartum, and HM cows mobilized muscle. The HM cows had higher milk fat, protein, lactose, and energy corrected milk yields. The BCVFA supplementation tended to increase blood glucose concentrations both prepartum and postpartum and decreased milk urea nitrogen concentrations. Higher prepartum skeletal muscle reserves improve productivity of early lactation cows likely due to differences in muscle mobilization, and BCVFA supplementation improves glucose dynamics during the transition period, which may improve the metabolic health of the periparturient dairy cow.

Blockchain-Enhanced Hydrogen Fuel Production and Distribution for Sustainable Energy Management

Renewable energy projects, particularly wind and solar farms, have garnered significant attention as a potential solution to global energy challenges. Despite the energy production obstacles, the steady availability of fossil fuels continues to compete due to established distribution systems, as societies increasingly rely on electricity. Hydrogen fuel emerges as a promising avenue for energy production, storage, and distribution, involving converting surplus renewable electricity into hydrogen through electrolysis, storing it, and distributing it. Our novel approach leverages blockchain technology to enhance the efficiency and traceability of hydrogen fuel production, offering a unique synergy of transparency, security, and decentralized governance. We showcase its viability and effectiveness using the ERC-1155 token standard to tokenize renewable resources and convert them into hydrogen fuel. Within our tokenized fuel blockchain architecture, we simulate the forecasted growth in hydrogen production and vehicle demand, highlighting our approach's efficiency, traceability, and transparency. This integration showcases the potential for a sustainable hydrogen fuel ecosystem. The gas consumption data analysis indicates that the daily gas consumption remains below 194 million Gas for refilling 3245 vehicles (including the cost of one-time contract deployment), demonstrating the feasibility and efficiency of our approach.

Productive Capacities, Economic Vulnerability and Growth Volatility in Sub-Saharan Africa

Productive Capacities, Economic Vulnerability and Growth Volatility in Sub-Saharan Africa

Europe's orchard: The role of irrigation on the Spanish agricultural production

In the latter half of the twentieth century, Spanish agriculture witnessed sustained production growth, aligning with Western European levels after a period of lag in both production and productivity. This growth predominantly occurred in the warm, sunny provinces of southern and eastern Spain, which specialized in high-value crops such as fruits, vegetables, and olive oil. Various factors have been identified in the scientific literature as contributors to this transformation, including technological innovations, the internationalization of Spanish agriculture, domestic development, and advancements in irrigation. This paper aims to examine the impact of irrigation on Spanish agricultural production, focusing on the creation of regional and productive disparities since the mid-twentieth century. These diverse effects have been crucial in shaping the regional and product-specific specialization patterns that characterize the historical dynamism of Spanish agriculture. To that aim, we have compiled a comprehensive database containing detailed information on agricultural production values, irrigated and rainfed area and yields. The level of disaggregation of data, both in terms of production and regional breakdowns, enables us to identify specific regional and crop patterns. Additionally, this study highlights the significant and regionally varied transformations within the Spanish agricultural sector over the long term, which have had profound effects on rural areas.

An assessment of twenty-three mycorrhizal inoculants reveals limited viability of AM fungi, pathogen contamination, and negative microbial effect on crop growth for commercial products

Ensuring sustainable agriculture is crucial amidst global challenges, demanding effective methods to enhance soil health and nutrient cycling. Microbial inoculants, particularly arbuscular mycorrhizal (AM) fungi, offer promising solutions. However, concerns persist regarding the efficacy and quality control of commercial products. Past work assessing commercial inoculants have not controlled for fertilizers added to individual products when assessing product effects under typical use.This study examines twenty-three mycorrhizal inoculants using conventions of organic production to shed light on differences between laboratory grown fungi, commercial products, and field soil. Employing a comprehensive approach, inoculants were assessed through spore enumeration, root infection potential, and crop growth response.The results uncover significant shortcomings in many commercial products compared to laboratory grown fungi. Key findings include discrepancies of up to 100 % in reported propagule counts versus spore concentrations, insufficient root colonization by commercial inoculants, and contamination by fungal plant pathogens, particularly Olpidium, in products. Moreover, while laboratory grown fungi exhibited superior symbiotic relationships with host plants due to increased colonization abilities and crop benefit, commercial inoculants often failed to deliver significant growth benefits when fertilizers are controlled for.These findings highlight the urgent need for improved standards and practices within the commercial inoculant industry.

The role of the acetyl-glutamate cycle in fumarate biosynthesis through L-ornithine supply via the ornithine-urea cycle in Aureobasidium pullulans var. aubasidani

In Aureobasidium pullulans var. Aubasidani, the ornithine-urea cycle (OUC) plays a role in fumarate biosynthesis with L-ornithine serving as a significant intermediate. The acetyl-glutamate cycle (AGC) is also responsible for synthesizing L-ornithine. But it remains unclear whether AGC can assist OUC in fumarate biosynthesis. N-acetyl-glutamate kinase and N-acetyl-gamma-glutamyl-phosphate reductase present in AGC were both encoded by the ARGBC gene in A. pullulans var. Aubasidani and N-acetyl-glutamate kinase was observed to be insensitive to feedback inhibition by L-arginine from OUC. This observation could be attributed to the presence of conserved residues, specifically L-threonine (T340) and L-arginine (R336), in the N-acetyl-glutamate kinase as opposed to the conserved L-threonine (T340) and L-lysine (K336) residues that could interact with L-arginine. Hence, AGC remained active and consistently produced L-ornithine for OUC. The deletion of the ARGBC gene in the parent glucose oxidase-deficient mutant (Δgox) led to decreased L-ornithine accumulation and reduced fumarate production in the disruptant Δgox Δargbc while complementation of the ARGBC gene enhanced accumulation of L-ornithine and restored fumarate production by the complementing strain ARGBC-H. The introduction of exogenous L-arginine clearly impacted fumarate production and cell growth in the disruptant strain Δgox Δargbc. It was concluded that achieving elevated fumarate levels through OUC, maintaining the activity of AGC for high L-ornithine accumulation was crucial. The produced fumarate had many applications.

Assessing the Efficacy of Organic and Chemical Treatments for Varroa Mite Control in Macedonian Apiaries

Varroa destructor infestations pose a significant global threat to honeybee colonies, affecting bee populations and honey production. The purpose of this study is to assess the performance of Apis mellifera L. honeybee colonies under various control methods with a particular focus on critical parameters like mite dewdrop, honey production and colony growth. The study took place in a normal apiary in the Pelister district for a year from April 2021 to March 2022. There were three treatment groups: Group A got Amitraz (a chemical treatment), group M got formic acid (an organic treatment) and group K got nothing (a control group) to see how the treatments affected the bees. Regular monitoring assessed parameters including dropped mites and Varroa infestation levels with honey production evaluated seasonally. The results showed that both chemical and organic treatments successfully decreased the levels of Varroa mite infestation compared to the control group, while also noting differences in colony growth and honey production. The Amitraz treatment did prevent the mites from dropping, but it also slowed down the young's development. On the other hand, the formic acid treatment kept the brood's development healthy, suggesting that it might be a better way to get rid of varroa. This study shows how important it is to think about how treatments affect important colony parameters. It also calls for more research like longterm observations, to fully understand how treatments affect the health, development and longevity of bee families which will eventually lead to the creation of more effective combined pest control methods.