Level Of Reserves Research Articles

Sleep-wake behavior, perceived fatigability, and cognitive reserve in older adults.

The effects of sleep-wake behavior on perceived fatigability and cognitive abilities when performing daily activities have not been investigated across levels of cognitive reserve (CR). CR Index Questionnaire (CRIq) data were collected and subjected to moderated mediation analysis. In amnestic mild cognitive impairment (aMCI; n=41), CR moderated sleep-related impairments (SRIs), and fatigability at low CR (CRIq<105.8, p=0.004) and mean CR (CRIq=126.9, p=0.03) but not high CR (CRIq>145.9, p=0.65) levels. SRI affected cognitive abilities mediated by fatigability at low CR (p<0.001) and mean CR (p=0.003) levels. In healthy controls (n=13), SRI in fatigability did not alter cognitive abilities across CR levels; controls had higher leisure scores than patients with aMCI (p=0.003, effect size=0.93). SRI can amplify impaired cognitive abilities through exacerbation of fatigability in patients with aMCI with below-mean CR. Therefore, improving sleep-wake regulation and leisure activities may protect against fatigability and cognitive decline. Clinical fatigue and fatigability cannot be alleviated by rest. Clinical fatigability disrupts daily activities during preclinical Alzheimer's. High cognitive reserve mitigates sleep-wake disturbance effects. High cognitive reserve attenuates clinical fatigability effects on daily functioning. Untreated obstructive sleep apnea potentiates Alzheimer's pathology in the brain.

Educational models and technologies in the era of digital transformation

   At present digital transformation of the society faces the problem of a shortage of a highly qualified personnel - specialists in the field of the latest information technologies, intellectual scientists with a high-quality fundamental education. The solution to this problem lies in the introduction of new educational models and technologies.   The purpose of the research is to study the strategy for the formation of a new conceptual scheme of modern education.   It has been emphasized that two leading educational models are currently being successfully implemented and complement each other: the classical model of «completed» education with the basic principle of «education once and for life», covering the need of the society for the generation and dissemination of knowledge, as well as the storage of cultural ideals, and the second model, called the «lifelong education model», which meets the principle of «lifelong education», corresponding to the rapid changes in technology and the nature of digital transformations of the society. The article pays special attention to new educational technologies such as: 1) analytical technologies, which are based on the analysis of big data from educational institutions in real time; 2) adaptive (or intellectual) learning, which is based on the principles of personalization of learning and building an individual educational trajectory; 3) Smart education, using learning tools in an interactive educational environment with elements of distance and mobile education. The methodological basis of the research is a systematic approach and general methods of scientific knowledge, such as analysis, synthesis, generalization.   The relevance of the topic is associated with increased attention to the problem of matching the quality of the Russian education with the promising tasks of the digital transformation of the Russian society.   Key conclusion. A high professional level of the personnel reserve, which will be able to practically implement state digitalization programs, is possible and is associated with the construction of a new concept of modern education.

Sucrose-associated SnRK1a1-mediated phosphorylation of Opaque2 modulates endosperm filling in maize

During maize endosperm filling, sucrose not only serves as a source of carbon skeletons for storage-reserve synthesis, but also acts as a stimulus to promote this process. However, the molecular mechanism details about sucrose and endosperm filling are poorly understood. Here, we found that sucrose promoted the expression of endosperm-filling hub Opaque2 (O2), coordinating with storage-reserve accumulation. A protein kinase called SnRK1a1 attenuated O2-mediated transactivation, but sucrose released the suppression. SnRK1a1 phosphorylated O2 at Serine 41 (S41), negatively affecting its protein stability and transactivation ability. Mutation of SnRK1a1 resulted in larger seeds with increased kernel weight and storage reserves, while overexpression of SnRK1a1 had the opposite effect. Overexpression of the native O2 (O2-OE), phospho-dead (O2-SA) and phospho-mimetic (O2-SD) variants all increased 100-kernel weight. Although O2-SA seeds exhibited smaller kernel size, they synthesized higher starch and proteins, thereby resulting in larger vitreous endosperm and increased test weight. O2-SD seeds displayed larger kernel size, but had unchanged levels of storage reserves and test weight. O2-OE seeds represented an admixture of O2-SA and O2-SD, showing elevated kernel dimensions and nutrient storage. Overall, this study discovered a novel mechanism to modulate endosperm filling and S41 in O2 offered potential for engineering efforts to enhance storage-reserve accumulation and yield in maize.

When Tariffs Disrupt Global Supply Chains

We study unanticipated tariffs in a setting with firm-to-firm supply relationships. Firms conduct costly searches and negotiate with potential suppliers that pass a reservation level of match productivity. Global supply chains form in anticipation of free trade. Then, the home government surprises with an input tariff. This can lead to renegotiation with initial suppliers or search for replacements. Calibrating the model’s parameters to match initial import shares and the estimated responses to the US tariffs imposed on China, we find an overall welfare loss of 0.12 percent of GDP, with substantial contributions from changes in input sourcing and search costs. (JEL D72, F13, F14, L14, O19, P33)

International reserves, currency depreciation and public debt: New evidence of buffer effects in Africa

The paper adds to the literature on the issue of public debt in African economies, by investigating the role foreign exchange reserves play in improving the level of indebtedness and as buffer of the negative effect of exchange rate depreciation while considering the exchange rate policy. Our results show a direct link between the level of foreign currency reserves and that of external debt in Africa. Particularly, we demonstrate that higher foreign currency reserves tend to decrease the public debt stock to GDP. This effect is even more significant when countries go through high exchange rate depreciation episodes (10% or higher). This impact, however, is not homogenous among country groups, as only countries with a floating exchange regime tend to benefit from this buffer effect compared to anchored regimes. In a time where most African economies face severe exchange rate depreciation episodes following the U.S. monetary tightening policy, central bankers and policy makers need to consider a plethora of policy issues including interventions in the FX market to mitigate depreciations and maintain a sustainable public debt stock.

Brain reserve affects the expression of cognitive reserve networks.

Cognitive reserve (CR) explains differential susceptibility of cognitive performance to neuropathology. However, as brain pathologies progress, cognitive decline occurs even in individuals with initially high CR. The interplay between the structural brain health (= level of brain reserve) and CR-related brain networks therefore requires further research. Our sample included 142 individuals aged 60-70 years. National Adult Reading Test intelligence quotient (NART-IQ) was our CR proxy. On an in-scanner Letter Sternberg task, we used ordinal trend (OrT) analysis to extract a task-related brain activation pattern (OrT slope) for each participant that captures increased expression with task load (one, three, and six letters). We assessed whether OrT slope represents a neural mechanism underlying CR by associating it with task performance and NART-IQ. Additionally, we investigated how the following brain reserve measures affect the association between NART-IQ and OrT slope: mean cortical thickness, total gray matter volume, and brain volumes proximal to the areas contained in the OrT patterns. We found that higher OrT slope was associated with better task performance and higher NART-IQ. Further, the brain reserve measures were not directly associated with OrT slope, but they affected the relationship between NART-IQ and OrT slope: NART-IQ was associated with OrT slope only in individuals with high brain reserve. The degree of brain reserve has an impact on how (and perhaps whether) CR can be implemented in brain networks in older individuals.

Effects of cognitive reserve on cognitive frailty among older adults: A population-based prospective cohort study.

We investigated the effect of lifespan cognitive reserve and its components on cognitive frailty among older adults. A total of 4922 participants aged ≥65 years were recruited in 2008 and were followed up in 2011 from the Chinese Longitudinal Healthy Longevity Survey. Cognitive frailty was determined through the simultaneous presence of physical frailty (pre-frailty or frailty) and mild cognitive impairment, excluding concurrent dementia. The assessment of physical frailty and mild cognitive impairment was based on the Fatigue, Resistence, Ambulation, Illness, Loss of weight (FRAIL) (Fatigue, Resistence, Ambulation, Illness, Loss) and Mini-Mental State Examination scale, respectively. The lifespan cognitive reserve consisted of education attainment, occupational complexity and later-life leisure activities. We used logistic regression models to estimate the risk of cognitive frailty associated with the lifespan cognitive reserve and its components. A higher level of lifespan cognitive reserve, higher educational attainment or leisure activities engagement, but not occupational complexity, were associated with lower risk of incident cognitive frailty. Furthermore, cognitive, social and physical activities were associated with lower risk of incident cognitive frailty. Cognitive reserve, particularly educational attainment and leisure activities, can protect from cognitive frailty. This implicates that individuals should accumulate cognitive reserve in their lifespan, and older adults should actively participate in leisure activities to prevent cognitive frailty. Geriatr Gerontol Int 2024; 24: 398-403.

Ecological Risk Assessment of Forest Landscapes in Lushan National Nature Reserve in Jiangxi Province, China

It is highly valuable to analyze and assess the landscape ecological risk of nature reserves to prevent and resolve ecological risks, as well as to effectively protect and maintain the sustainable development of nature reserves. Taking the forest landscape of the Lushan National Nature Reserve as its study object, this study performed grid processing for the nature reserve and classified forest landscape types using the Forest Resource Inventory Database in 2019. A landscape ecological index model was constructed to evaluate the ecological risk. Global and local Moran index values were used to reveal the autocorrelations for ecological risk. The geodetector method was used to comprehensively analyze the effects of natural and human factors on ecological risk. The results showed that, in general, the ecological risk level of the nature reserve was relatively low, as the proportion of the lowest-, lower-, and medium-risk areas to the total forestry land area accounted for 91.03%. The ecological risk ranking of each functional zone, from high to low, was in the order of the experimental zone, the buffer zone, and the core zone. The ecological risk levels of different forest landscape types were closely related to their area, spatial distribution, and succession stage, as well as human factors, such as the proximity to roads and settlements, etc. The forest landscape with the highest ecological risk was the Cunninghamia lanceolata (Lamb.) Hook. forest, and the forest landscape with the lowest ecological risk was other forestry land. Ecological risk had a positive spatial correlation and tended to be aggregated in space, demonstrating coupling with the proximity to roads and settlements. The ecological risk was affected by both human and natural factors, among which human factors played a dominant role. The proximity to roads and settlements, the relative humidity, and the temperature were the main driving factors. The interaction of pairwise factors had a stronger influence than that of single factors. Therefore, controlling the intensity of human activities and enhancing the coordination between humans and nature are beneficial for alleviating the ecological risks in the forest landscapes of nature reserves.

Modelling the Demand for Indonesia’s Foreign Reserves

Abstract The foreign reserves sufficiency is important to maintain macroeconomic stability. The main objective of this paper is to model the behaviour of the central bank in accumulating the foreign reserves in the case of Indonesia. Unlike the previous empirical studies, this paper disaggregates the components of foreign reserves into foreign currency, securities, gold, and special drawing rights. This paper relies on the Almost Ideal Demand System combined with the Error Correction Model. The estimation result for monthly data over the period 2010(1)-2020(12) reveals that the own-price coefficients are negative and statistically significant which is consistent with the standard theory of demand. While the foreign currency-securities pairwise is substitutive, the foreign currency-gold and the foreign currency-special drawing rights pairwise are complementary or even independent. However, the wealth effect is inelastic except for securities reserves. These results imply that the central bank of Indonesia can re-balance its reserves. The securities holding which have the highest proportion of foreign reserve scan be switched to foreign currency, gold, and/or special drawing rights. The rebalancing measures would remain having an optimal level of foreign reserves holding in terms of its opportunity cost. Therefore, the monetary authority can conduct a further macroeconomic stabilisation without substantially losing the returns.

Динамика физиологических показателей студентов г. Луганска при прохождении практики в высокогорье

Adverse ecological conditions put a strain on the functional reserves of young people. Hypoxic training in the mountains is the gold standard of adaptive physiology. The purpose of this paper was to study the physiological parameters of young Lugansk residents moving from the lowlands to the highlands. Materials and methods. Students of Lugansk State Pedagogical University (n = 19) were examined before, during and after their stay in the Elbrus region. To monitor the physiological parameters, pulse oximetry was performed using the MD300M device, blood pressure was measured using the auscultation method, Kérdö index and CO2 concentration in the blood using capnometry were determined. Results. The baseline level of health in students was found to be low. After a 5-day stay in the mountains, a certain increase in physiological well-being was noted, which persisted upon returning to Lugansk (aftereffect period). Namely, heart rate (HR) decreased from 86.14 ± 3.63 to 81.16 ± 2.19 bpm; 10 days later the effect remained: HR was 80.87 ± 4.77 bpm. Oxygen saturation increased from 94.86 ± 0.31 to 96.16 ± 0.32 %; on the 10th day upon returning to the city, it was 95.29 ± 0.33 %. Autonomic balance shifted from sympathicotonia (Kérdö index = 22.92 ± 5.48 conventional units) towards normotonia (Kérdö index = 15.56 ± 3.55 conventional units). CO2 concentration in the arterial blood was 4.73 ± 0.08 % at baseline, 5.03 ± 0.15 % on the 3rd day in the mountains, 5.16 ± 0.20 % on the 2nd day of aftereffect, and 4.86 ± 0.09 % on the 10th day. Breath-holding time increased, which indicates that adaptation to hypoxia occurred. During their stay in the mountains, students went on daily hikes at 1500– 3450 m above sea level. The fluctuating mode of hypoxic training was accompanied by a subjective feeling of unwellness, weakness and vertigo, which is understandable considering the mechanisms of physiological adaptation to hypoxia. The results of the study confirm that measures need to be taken in order to increase the level of functional reserves of young people living in Lugansk.

Reserve holding and bank lending

Banks’ ability to convert liquidity into lending depends crucially on the various regulatory constraints they face. This paper investigates the differential lending responses of banks with varying levels of reserves, and their impact on the real economy. The distribution of reserves within the banking system became significantly more dispersed during the quantitative easing (QE) periods. Loan growth for those more liquidity-constrained does not vary meaningfully with liquidity changes, despite abundance at the aggregate level. Consequently, our findings imply that the uneven bank reserve distribution may exacerbate the spatial disparities in bank lending and regional economic development through differential lending responses of banks in different parts of the reserve distribution.

Analysis of the Uniformity of Mechanical Properties along the Length of Wire Rod Designed for Further Cold Plastic Working Processes for Selected Parameters of Thermoplastic Processing.

This study presents the results of research, the aim of which was to analyze the uniformity of the distribution of selected mechanical properties along the length of a 5.5 mm diameter wire rod of 20MnB4 steel for specific thermoplastic processing parameters. The scope of the study included, inter alia, metallographic analyses, microhardness tests, thermovision investigations, and tests of the wire rod mechanical properties (yield strength, ultimate tensile strength, elongation, relative reduction in area at fracture), along with their statistical analysis, for three technological variants of the rolling process differing by rolling temperature in the final stage of the rolling process (Reducing Sizing Mill rolling block [RSM]) and by cooling rate using STELMOR® cooling process. The obtained results led to the conclusion that the analyzed rolling process is characterized by a certain disparity of the analyzed mechanical properties along the length of the wire rod, which, however, retains a certain stability. This disparateness is caused by a number of factors. One of them, which ultimately determines the properties of the finished wire rod, is the process of controlled cooling in the STELMOR® line. Despite technological advances concerning technical solutions (among them, increasing the roller track speed in particular sections), it is currently not possible to completely eliminate the temperature difference along the length of the wire rod caused by the contact of individual coils with each other. From this point of view, for the analyzed thermoplastic processing parameters, there is no significant impact by the production process parameters on the quality of the finished steel product. Whereas, while comparing the mechanical properties and microstructure of the wire rod produced in the different technological combinations, it was found that the wire rod rolled in an RSM block at 850 °C and cooled after the rolling process on a roller conveyor at 10 °C/s had the best set of mechanical properties and the smallest microstructure variations. The wire rod produced in this way had the required level of plasticity reserve, which enables further deformation of the given type of steel in compression tests with a relative plastic strain of 75%. The uniformity of mechanical properties along the length of wire rods designed for further cold plastic working processes is an important problem. This is an important issue, given that wire rods made from 20MnB4 steel are an input material for further cold plastic working processes, e.g., for the drawing processes or the production of nails.

Optimum Level of Currency Reserves: Investigation and Forecasting of Indian Rupee Using ARIMA Model

Optimum Level of Currency Reserves: Investigation and Forecasting of Indian Rupee Using ARIMA Model

Excess cash and equity option liquidity

AbstractWe examine the relation between excess corporate cash holdings and equity option market liquidity from January 3, 2005 to December 31, 2019. We show that the level of cash reserve in excess of what can be captured by firm characteristics significantly explains stock option liquidity. Trading volume and option open interest increase in companies with a higher magnitude of excess cash, whereas the bid–ask spreads of stock options decline in excess cash. Our findings confirm the theoretical prediction that excess cash improves option market liquidity as it reduces adverse selection problems caused by uncertainty in firm valuations. This relation remains more pronounced with put options, out‐of‐the‐money contracts, and short‐maturity contracts. In addition, excess cash has a stronger impact on option liquidity within firms that have a greater degree of informed trading and during high‐volatility periods in financial markets. Our results show that when uncertainty about firm prospects rises, excess cash becomes more valuable and affects option market liquidity.

CubeSat Mission Scheduling Method Considering Operational Reliability

Mission scheduling is an effective method to increase the value of satellite missions and can greatly improve satellite resource management and quality of service. Based on the priority-based task scheduling model, this paper proposes a CubeSat scheduling method that takes operational reliability into account, considering the impact of scheduling results on reliable operation. In this method, the available energy and the time window are used as scheduling resources, and the average state of charge of the lithium battery and the number of task start-ups are defined as two indices to measure its reliability. To meet the mission requirements and energy availability of photovoltaic (PV) solar panel and battery constraints, the scheduling model is constructed with an objective function that includes mission priority and reliability index. The branch and bound (BB) method and analytical hierarchy process (AHP) method are used to solve the scheduling problem. The example analysis compares different scheduling results and verifies the effectiveness of the proposed scheduling method. Compared with the existing methods, it comprehensively considers the mission value and operational reliability of the CubeSat, improves the energy reserve level of the CubeSat, and reduces the surge current caused by the start-up of tasks.

Managing liquidity along the supply chain: Supplier‐base concentration and corporate cash policy

AbstractWe find that customer firms with more concentrated supplier bases tend to hold higher levels of cash reserves. The positive relation between supplier‐base concentration and cash holdings is more pronounced for firms with nonstate ownership, higher market competition, worse inventory efficiency, more relationship‐specific investment, central positions in the production networks, and headquarters located in regions with lower levels of financial development. Furthermore, we show that debt issuance enhances firms' cash holdings when they have concentrated suppliers, and supplier‐base concentration increases firms' cash spending on R&amp;D investment. Our study highlights the importance of supplier structure in shaping corporate cash policy.

Epidemic modelling and actuarial applications for pandemic insurance: a case study of Victoria, Australia

Abstract With the recent outbreak of COVID-19, evaluating the epidemic risk appears to be a pressing issue of global concern and one of the major challenges recently. In the fight against pandemics, the ability to understand, model, and forecast the transmission dynamics of infectious diseases plays a crucial role. This paper provides an overview of foundational compartment models and introduces the Susceptible-Exposed-Infected-Containing-3-Substates-Recovered-Dead model to study the dynamics of COVID-19. A meticulous data calibration procedure is employed to study the evolution trend of an actual pandemic using real-world data from Victoria, Australia. Additionally, the paper discusses innovative applications of epidemic models to the insurance industry, which are currently under investigation. Through the use of the newly developed analytically tractable model, insurance companies are able to determine fair premium levels during an outbreak. Moreover, the paper provides practical guidance for insurance companies by examining the variation in reserve levels over time.

Study on biaxial bending fatigue performance of Engineered Cementitious Composites (ECC)

Structural components such as bridge deck, highway pavement and thin-walled roof dome often are subjected to the biaxial and even multi-axis stress state due to the external load. Also, the fatigue effect cannot be ignored due to the moving vehicle load in the design of these structures. If engineering cementitious composites (ECC) is used in the above traditional concrete structures, their performance, such as easy cracking and short service life can be greatly improved. However, the biaxial bending fatigue performance of ECC should be analyzed in detail. At present, the biaxial bending test methods of cement-based materials include biaxial bending test (BFT) and centrally loaded round panel test (RPT). This study used both RPT and BFT test methods to analyze the biaxial fatigue performance of ECC and used four-point bending test (4PBT) uniaxial fatigue test as a reference. The stress levels S were set as 0.5, 0.6 and 0.7. The uniaxial and biaxial bending fatigue failure procedures of ECC were analyzed by plotting the three-stage deflection development curve, the fatigue damage and strain relationship curve based on the linear cumulative fatigue damage theory, and the S–N curve. The fatigue life of ECC biaxial bending specimens was greater than that of uniaxial bending specimens. At S = 0.5, the fatigue life: BFT > RPT. At S = 0.6, the fatigue life of BFT and RPT specimens was close. At S = 0.7, the fatigue life: BFT < RPT. With increasing stress level, the fatigue life of BFT specimen decreases more than that of RPT specimen. The lognormal distribution model and Weibull distribution model were used to fit the uniaxial and biaxial bending fatigue life of ECC, respsectively. Using the double logarithmic fatigue equation, fatigue life under the failure probability PF of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 was derived. The survival rate represents the level of safety reservation, which could provide reference and basis for the design of ECC bridge deck and highway pavement with different safety reservation requirements.

THEORETICAL PRINCIPLES OF ANTI-CRISIS MANAGEMENT OF FOREIGN ECONOMIC ACTIVITIES OF ENTERPRISES

The article reveals the theoretical principles of anti-crisis management of the enterprise's foreign economic activity. The essence of the concept of crisis is revealed. Attention is drawn to the importance of adaptive anti-crisis management aimed at responding to changes and using opportunities to ensure the sustainable development of the enterprise in the conditions of the external environment. The internal and external causes of the crisis are singled out. The classification, tasks, and main principles of anti-crisis management are substantiated. The key elements of managing the foreign economic activity of the enterprise in crisis conditions, as well as the main approaches to minimizing the impact of threats, are considered. Taking into account the importance of developing anti-crisis programs to prevent and overcome crises at the enterprise, the key methods of work to minimize the impact of threats to the enterprise's foreign economic activity were analyzed, such as: minimizing threats through diversification, information search, risk management, interaction with the environment, control of the internal environment. Diversification approaches have been proven to be the most common and effective in protecting foreign economic activity, but require careful, long-term planning and significant financial investment. It is substantiated that obtaining timely information about the state of the market and the industry is an important step toward reducing threats. Attention is drawn to the fact that risk management covers a wider range of actions than crisis management, including identification, analysis, assessment, management, and mitigation of risks that may arise. Emphasis is placed on ensuring the appropriate level of resource reservation, which is aimed at maintaining the necessary stock of cash, raw materials, goods, and other necessary materials. The importance of establishing long-term partnership relations in the implementation of the enterprise's foreign economic activity has been proven. It has been proven that a comprehensive approach to the creation of a system of anti-crisis management of the enterprise's foreign economic activity should include the organization, planning, and implementation of not only specific competencies but also effective management tools that will help the enterprise adapt to changes and increase its competitiveness.

Characteristics and cognition of older adults engaged in lifelong learning

ABSTRACT Lifelong learning programs for older adults are suggested as a promising strategy to promote successful and active aging. This observational study utilized cross-sectional data from a nationwide survey administered to adults aged 65 and older who were recruited through nine Osher Lifelong Learning Institutes (OLLI). Data collected included general demographics, and measures of physical and mental health, cognitive ability, meaning and purpose, cognitive reserve, and successful aging. Descriptive characteristics of the population revealed a predominantly White, female population, the majority of whom were married, retired, and reported high levels of educational attainment. Participants reported high levels of physical and mental health, and meaning and purpose as measured by PROMIS® measures. High levels of cognitive reserve, self-reported cognitive ability, and successful aging were also found in this sample. Using references to the general aging adult population comparative analyses found OLLI participants reported significantly higher physical health and mental health, and cognitive reserve scores. This study provides additional context for understanding characteristics of older adults who are cognitively aging well.