Equilibrium Level Research Articles

Oil-Based Delivery Control Release System Targeted to the Later Part of the Gastrointestinal Tract-A Mechanistic Study.

Oil-based drug delivery systems have been studied in different aspects. The present study proposes a new application for an oil-based delivery system, focusing on controlled release until the drug reaches the later part of the small intestine. Bulk surfactants and interfacial surfactants were added into the oil formulation to provide a better mechanistic understating of the lipolysis. Validation of the modified in vitro method shows the overall conversion from medium-chain triglyceride oil (MCT oil) to free fatty acids (FFA) of 100 ± 4% in five replicates. This fully converted level and high reproducibility are fundamental for the following investigations where any retarding effect can be distinguished from the experimental errors. The results show that viscosity and thermodynamic activity have limited retardation. Furthermore, the former may change the kinetics of lipolysis, while the latter changes the equilibrium level. The gel-forming retarder (ethylcellulose) displayed a strong effect. Whereas the lipolysis was significantly retarded (>50%) when the retarders altered the interfacial composition (poloxamer 407), degradable interfacial surfactants did not have the same effect. However, surface-active, lipolysis-resistant retarders with a high CMC did not show a retarding effect.

Effects of delay in a biological environment subject to tumor dynamics

In the present work, we perform a study investigating a generic model of tumor growth with a delay distribution in the proliferation of tumor-stimulating effectors using combinations of analytical and numerical methods. We examine two borderline cases of the distribution: the first limit case is the Dirac distribution, leading to a model with constant delay and the second limit case is the exponential distribution leading to a model with an additional equation. The main objective is to assess the effect of delays in the response of the immune system on the dynamic stability of interaction between tumor, immune and host cells. Analytical and numerical investigations reveal that in the absence of delay, the stationary states of the two models can be stable or unstable for all the parameters used. In the case of constant delay, the analysis focuses on the stability switch with increasing delay. We show using the generalized Sturm criterion that the space of the parameters of concern is divided into four regions determined by a sequence of discrimination and the Routh-Hurwitz conditions: the system can undergo no stability switch and remain unstable regardless of the delay or undergo exactly a stability switch causing the coexisting equilibrium to pass from stable to unstable when the parameters are chosen in a well-defined region. This shows that the delay plays the role of destabilizer and not of stabilizer. We also show in this case that the destabilization of the system by the delay induces a chaotic behavior in the a priori non-chaotic system in the absence of delay. In the case of exponential distribution, we show that the delay induces certain phenomena such as the Hopf bifurcation, the doubling of periods, the intermittence by saddle-node bifurcation and chaos. We show the importance of characterizing the delay-induced chaos and dynamic states of the system by examining the maximum tumor size for each dynamic state. In both cases of study, it is observed that small delays guarantee stability at the stable equilibrium level, but delays greater than a critical value can produce periodic solutions by Hopf bifurcation and larger delays can even lead to chaotic attractors. The implications of these results are discussed. We examined the other scenarios by showing the influence of the probability density parameters on the behavior of the solutions as well as the dynamics of the model. It is shown that, the region of stability for distributed delays is relatively larger than that of the presence of any discrete delay.

METHODICAL REGULATION AND ANALYTICAL AND INFORMATION SUPPORT OF "SMART HOME" PROJECTS IN THE MODERN CONSTRUCTION DEVELOPMENT SYSTEM

The article is devoted to the impact of the development of information, communication and digital technologies on the transformations taking place in "smart home" construction projects. Modern technological trends in the development of the digital economy have been studied. Prerequisites, challenges and drivers of digital transformation of domestic business structures are structured, with their division into external and internal, which can act as a basis for determining the vectors of innovative development of enterprises based on "numbers". It was determined that digital technologies and data obtained from their use can provide new sources of knowledge, innovation and profit for business. It is noted that information and communication technologies are a fundamental stimulus for the growth of international production. Coordination of increasingly complex and scattered global production networks could not be possible without significant improvement in communication capabilities. The directions of the main transformations taking place in the existing approaches to the organization and management of international production systems are determined. As a systematic scientific and applied support for the competitiveness of enterprises implementing construction projects on the basis of the introduced methodology and the corresponding apparatus of formalized decision-making, the toolkit of digital administration was substantiated by the activities of СЕ-S (construction enterprise-stakeholder). The leading subsystems of the toolkit are the following: an integrated analytical and diagnostic subsystem, which, using a special system of indicators adapted to the economic, operational-production, functional-technological and administrative features of СЕ-S, provides a comprehensive analysis of the equilibrium level of BP-S regarding the enterprise's preservation of progressive development or certain (non-critical, risky, to critical, critical) deviation of the enterprise in this trajectory; subsystem of organizational management with the introduction of innovative management, organizational-administrative and information technologies; СЕ-S personnel motivation subsystem, which is integrated into the enterprise management circuit. With the use of the specified subsystems, the toolkit provides economic controlling, administration and adjustment of CE activities. On its basis, the obligation of economic, managerial, organizational, technical and administrative measures aimed at adaptive adjustment of the content, operational and strategic priorities in BP-S activities, countering risk factors, with the aim of avoiding and countering cost-economic, administrative-management and structural-technological deviations from the directive trajectory of the enterprise as a whole, and, in particular, within the scope of the project in which CE-S is currently conducting its activities. In this way, the toolkit provides the essence of the digital transformation of enterprises to the format of the integrator of the functional, production and logistics subsystems of the operating system of the enterprises of construction stakeholders.

THE EFFECT OF ALLEE FACTOR ON A NONLINEAR DELAYED POPULATION MODEL WITH HARVESTING

The Allee effect may have a stabilizing or destabilizing effect on population dynamics, or reaching stability may be delayed. Also this effect can push populations to extinction, especially under sharp harvesting effect. Compensatory or overcompensatory population maps are situations that change the effect of the Allee factor on population dynamics. The harvesting factor has also the effect of changing the equilibrium levels differently in theoretical population models. This study includes the local stability of the equilibrium point of the delayed discrete-time population model exposed to the harvest effect with and without Allee effect. We also review the effect of Allee factor on the local stability of equilibrium point of the discrete-time population model involving delay [1]. The dynamics of this population models are given together with the enriched dynamics.

Behavioral Economic Consequences of Disasters: A Basis for Inclusion in Benefit-Cost Analysis.

The purpose of this paper is to develop an analytical framework for estimating the behavioral effects of disasters and their economic consequences. The reduction of these losses represents the benefits of pre-disaster mitigation and post-disaster recovery. We provide conceptualizations, definitions, classifications, and a formal welfare analysis of this category of economic consequences. We also examine methods used to measure behavioral reactions to fear for insight into improving their delineation. Because we are interested in a comprehensive assessment of behavioral effects, we also include resilience adjustments and extend our initial partial equilibrium analysis to the general equilibrium level. The analysis is intended to serve as the basis for the legitimate inclusion of behavioral consequences of disasters in benefit-cost analysis.

An Import Demand Function for Long Grains (Indica) Rice for Saudi Arabia: A Vector Error Correction Model (VECM)

A vector error correction model (VECM) was utilized to estimate an import demand function for indica rice for Saudi Arabia using time series data spanning the period 1983 – 2018. Results established a long run relationship between import demand quantity, import prices, per capita income, population, and crop index. Import demand quantity was found to adjust to restore long term equilibrium level significantly fast, as full adjustment would be attained within two years. Short run demand elasticities with respect to price and income confirmed that rice is a necessary normal good. The rather low income elasticity suggests that at higher incomes consumers would probably respond by shifting to more expensive rice (basmati) varieties. Positive population shocks were found to have a maintained long run negative impact on imports which reflects and confirms dietary shifts away from traditional rice dishes in Saudi Arabia.

Magmatic water content controls the pre-eruptive depth of arc magmas.

Vanguard efforts in forecasting volcanic eruptions are turning to physics-based models, which require quantitative estimates of magma conditions during pre-eruptive storage. Below active arc volcanoes, observed magma storage depths vary widely (~0 to 20 kilometers) and are commonly assumed to represent levels of neutral buoyancy. Here we show that geophysically observed magma depths (6 ± 3 kilometers) are greater than depths of neutral buoyancy, ruling out this commonly assumed control. Observed depths are instead consistent with predicted depths of water degassing. Intrinsically wetter magmas degas water and crystallize deeper than dry magmas, resulting in viscosity increases that lead to deeper stalling of ascending magma. The water-depth relationship provides a critical constraint for forecasting models by connecting depth of eruption initiation to its volatile fuel.

Do oligopolistic firms benefit from being forced to act non‐strategically?

AbstractThe present study seeks to answer the question of whether acting non‐strategically can benefit firms. In a static Cournot framework, if a subset of firms are constrained to the equilibrium level of output, being non‐strategic will have no impact on profits of neither constrained nor strategic firms and provided that sufficiently large number of firms are restricted, a marginal quantity contraction can be to their benefit. In contrast, using a dynamic Cournot framework, we find that the constraint set at the equilibrium level or moderately deviated from it, leads to increased profits for all firms irrespective of the number of non‐strategic ones.

Indications of a Decrease in the Depth of Deep Convective Cores with Increasing Aerosol Concentration during the CACTI Campaign

AbstractAn aerosol indirect effect on deep convective cores (DCCs), by which increasing aerosol concentration increases cloud-top height via enhanced latent heating and updraft velocity, has been proposed in many studies. However, the magnitude of this effect remains uncertain due to aerosol measurement limitations, modulation of the effect by meteorological conditions, and difficulties untangling meteorological and aerosol effects on DCCs. The Cloud, Aerosol, and Complex Terrain Interactions (CACTI) campaign in 2018–19 produced concentrated aerosol and cloud observations in a location with frequent DCCs, providing an opportunity to examine the proposed aerosol indirect effect on DCC depth in a rigorous and robust manner. For periods throughout the campaign with well-mixed boundary layers, we analyze relationships that exist between aerosol variables (condensation nuclei concentration > 10 nm, 0.4% cloud condensation nuclei concentration, 55–1000-nm aerosol concentration, and aerosol optical depth) and meteorological variables [level of neutral buoyancy (LNB), convective available potential energy, midlevel relative humidity, and deep-layer vertical wind shear] with the maximum radar-echo-top height and cloud-top temperature (CTT) of DCCs. Meteorological variables such as LNB and deep-layer shear are strongly correlated with DCC depth. LNB is also highly correlated with three of the aerosol variables. After accounting for meteorological correlations, increasing values of the aerosol variables [with the exception of one formulation of aerosol optical depth (AOD)] are generally correlated at a statistically significant level with a warmer CTT of DCCs. Therefore, for the study region and period considered, increasing aerosol concentration is mostly associated with a decrease in DCC depth.

Play-Hysteresis in the Joint Dynamics of Employment and Investment

The slow recovery of many developed economies to the recent financial crisis, and the largest fall in aggregate demand since WWII caused by the COVID-19 Pandemic with its foreseeable negative and persistent effects on the aggregate supply, has generated renewed interest in the subject of hysteresis. The presence of significant hysteresis effects has important theoretical and policy implications. First, there is no unique and predetermined long-run equilibrium level of aggregate employment, as the equilibrium is permanently changed by temporary shocks. Second, as the economic system is not self-adjusting, substantial, timely, and sustained expansionary monetary and fiscal policy should be applied to mitigate the impact of shocks, including the temporary ones. Although it is not possible to quantify hysteresis effects in real time, we can use historical data to shed some light on the possible long-term economic consequences of the COVID-19 pandemic. For that purpose, we use the linear play-hysteresis model in the context of two equation system to analyses the join hysterical dynamics of aggregate employment and investment. We implement the model empirically by means of a new algorithm for the simultaneous equations system applied to Portuguese data that separates the effects of large and small changes in aggregate demand on aggregate employment and investment using an endogenous determined switching parameter as reference.

Photoaging of Baby Bottle-Derived Polyethersulfone and Polyphenylsulfone Microplastics and the Resulting Bisphenol S Release.

This study evaluated the release of bisphenol S (BPS) from polyethersulfone (PES) and polyphenylsulfone microplastics (MPs) derived from baby bottles under UV irradiation. Released BPS fluctuates over time because it undergoes photolysis under UV254 irradiation. Under UV365 irradiation, the highest released concentration at 50 °C was 1.7 and 3.2 times that at 35 and 25 °C, respectively, as the activation energy of the photochemical reactions responsible for MP decay was reduced at high temperatures. Low concentrations of humic acid (HA, ≤10 mg·L-1) promote BPS release because HA acts as a photosensitizer. A high concentration of HA (10∼50 mg·L-1) decreases the BPS release because HA shields MPs from light and scavenges reactive radicals that are produced via photochemical reactions. For example, under UV irradiation, hydroxyl radicals (•OH) attack results in the breakage of ether bonds and the formation of phenyl radicals (Ph•) and phenoxy radicals (Ph-O•).The•OH addition and hydrogen extractions further produce BPS from the decayed MPs. A leaching kinetics model was developed and calibrated by the experimental data. The calibrated model predicts the equilibrium level of BPS release from MPs that varies with the surface coverage density of BPS and leaching rate constants. This study provides groundwork that deepens our understanding of environmental aging and the chemical release of MPs.

The Brettenham storm of 25 July 2021

The <scp>Brettenham</scp> storm of 25 <scp>July</scp> 2021

Poverty Reduction and Economic Development in Nigeria

Extant literature shows that the incidence of poverty is one of the biggest threats to human development, however, not many studies have acknowledged the important role of financial development and access to internet services in reducing the incidence of poverty to enhance economic development. Therefore, this study examined the relationship between poverty reduction and economic development in Nigeria using data for the period of 2003Q1 to 2019Q4. The data for this study is collected from the United Nations Human Development Reports and the World Bank’s World Development Indicators Database. Using the Autoregressive Distributed Lag Model-Error Correction Modelling (ARDL-ECM) estimator, the results of the ARDL long-run estimates showed that poverty reduction, financial development, economic growth, trade openness, and the internet had positive and significant effects on human development. Furthermore, urbanisation had a negative but non-significant effect on human development, indicating a negative coefficient and exact p-value of 0.064735 and 0.8221. Meanwhile, the results of the ARDL short-run estimates except for urbanisation are consistent with the long-run results. Besides, the Error Correction Model (ECM), which indicates the speed of adjustment back to long-run equilibrium level after a short-run disturbance, showed a coefficient which is negative (-0.145327) and significant at 1% level of significance, implying that about 15% of any disequilibrium in the short-run is adjusted back to the long-run equilibrium in each quarter. Based on the long-run estimates, the study concludes that poverty reduction is important for economic development in Nigeria. It is, therefore, recommended that the poverty reduction strategies of the Nigerian government should not be pursued in isolation but rather in connection with access to financial and internet services, among other things.

Can C-budget of natural capital be restored through conservation agriculture in a tropical and subtropical environment?

Conservation agriculture through no-till based on cropping systems with high biomass-C input, is a strategy to restoring the carbon (C) lost from natural capital by conversion to agricultural land. We hypothesize that cropping systems based on quantity, diversity and frequency of biomass-C input above soil C dynamic equilibrium level can recover the natural capital. The objectives of this study were to: i) assess the C-budget of land use change for two contrasting climatic environments, ii) estimate the C turnover time of the natural capital through no-till cropping systems, and iii) determine the C pathway since soil under native vegetation to no-till cropping systems. In a subtropical and tropical environment, three types of land use were used: a) undisturbed soil under native vegetation as the reference of pristine level; b) degraded soil through continuous tillage; and c) soil under continuous no-till cropping system with high biomass-C input. At the subtropical environment, the soil under continuous tillage caused loss of 25.4 Mg C ha−1 in the 0–40 cm layer over 29 years. Of this, 17 Mg C ha−1 was transferred into the 40–100 cm layers, resulting in the net negative C balance for 0–100 cm layer of 8.4 Mg C ha−1 with an environmental cost of USD 1968 ha−1. The 0.59 Mg C ha−1 yr−1 sequestration rate by no-till cropping system promote the C turnover time (soil and vegetation) of 77 years. For tropical environment, the soil C losses reached 27.0 Mg C ha−1 in the 0–100 cm layer over 8 years, with the environmental cost of USD 6155 ha−1, and the natural capital turnover time through C sequestration rate of 2.15 Mg C ha−1 yr−1 was 49 years. The results indicated that the particulate organic C and mineral associate organic C fractions are the indicators of losses and restoration of C and leading C pathway to recover natural capital through no-till cropping systems.

Environmental offsets and production externalities under monopolistic competition.

In a monopolistically competitive model with production externalities, where individuals voluntarily provide offsets which compensate for degradation of environmental quality caused by their income earning activities, this paper examines how an increase in the population size affects the equilibrium levels of environmental quality, offsets, and net contributions. Whether labor supply is institutionally constrained or not, as the population size increases, environmental quality decreases and converges to zero. However, since offsets increase and converge to the degradation rate of environmental quality, the carbon neutrality theorem holds: net contributions are zero. These results are independent of the specification of the utility function.

Dynamics of sediment-laden plumes in the ocean

We present a series of experiments to illustrate the dynamics of positively or negatively buoyant particle-laden plumes in a cross-flow, with relevance for the discharge of sediment into the ocean during deep-sea mining operations. In an unstratified ambient fluid, our experiments identify three different regimes, corresponding to (i) a dense particle-laden plume, host to relatively dense saline fluid, in which the particles separate from the descending plume as the flow speed falls below the particle settling speed; (ii) a dense particle-laden plume, host to buoyant fluid, in which the fluid gradually rises from the sinking plume of particles, to form a second rising plume of source fluid; and (iii) a buoyant particle-laden plume, host to buoyant fluid, which rises from the discharge pipe, and from which particles gradually sediment. Classical models of single-phase plumes describe the initial motion of the plumes in cases (i) and (iii), but as the flow speed falls below the particle fall speed, sedimentation leads to a change in the averaged buoyancy, and, hence, the plume speed. Our data also suggest that the sedimentation leads to a reduction in the rate of entrainment of ambient fluid, compared with the classical single-phase plumes. We also show that with a density stratified ambient fluid, the stratification may arrest the plume prior to significant particle sedimentation, and in this case, the plume tends to spread downstream at the level of neutral buoyancy where particle sedimentation proceeds. The bulk density of the residual plume fluid may then remain intermediate between the density of the upper and lower layer fluid, or may become less dense than the upper layer fluid, in which case, following sedimentation, the plume fluid rises through the upper layer. While the dynamics of deep-sea mining plumes in the ocean are more complex, for example, owing to background turbulence and mixing, the results of our new laboratory experiments highlight the range of flow processes which may influence the initial dispersion and sedimentation of particles in such plumes following release into the water, depending on the initial conditions, the ambient density and the particle fall speed. We also discuss the relevance of our work in the context of ash dispersal by volcanic plumes.

Artificial Diffusion for Convective and Acoustic Low Mach Number Flows I: Analysis of the Modified Equations, and Application to Roe-Type Schemes

Three asymptotic limits exist for the Euler equations at low Mach number - purely convective, purely acoustic, and mixed convective-acoustic. Standard collocated density-based numerical schemes for compressible flow are known to fail at low Mach number due to the incorrect asymptotic scaling of the artificial diffusion. Previous studies of this class of schemes have shown a variety of behaviours across the different limits and proposed guidelines for the design of low-Mach schemes. However, these studies have primarily focused on specific discretisations and/or only the convective limit. In this paper, we review the low-Mach behaviour using the modified equations - the continuous Euler equations augmented with artificial diffusion terms - which are representative of a wide range of schemes in this class. By considering both convective and acoustic effects, we show that three diffusion scalings naturally arise. Single- and multiple-scale asymptotic analysis of these scalings shows that many of the important low-Mach features of this class of schemes can be reproduced in a straightforward manner in the continuous setting. As an example, we show that many existing low-Mach Roe-type finite-volume schemes match one of these three scalings. Our analysis corroborates previous analysis of these schemes, and we are able to refine previous guidelines on the design of low-Mach schemes by including both convective and acoustic effects. Discrete analysis and numerical examples demonstrate the behaviour of minimal Roe-type schemes with each of the three scalings for convective, acoustic, and mixed flows.

ANALYSING THE EXCHANGE RATE-INFLATION NEXUS: EVIDENCE FROM MAURITIUS

This paper examines the degree and speed of exchange rate passthrough (ERPT) to the inflation rate in Mauritius from 1980 to 2016 using dynamics regression analysis. Results reveal that the long-run ERPT elasticity to domestic inflation is incomplete and low. However, no such relationship is discovered in the short run. The speed of adjustment of actual inflation to its long-run equilibrium level is quite high and it takes approximately two years to attain that level. From a policy point of view, domestic inflation can be tamed by tightening the domestic money supply and maintaining exchange rate stability in the long run

Some aspects of carbon sequestration capacity of arable soils

The article analyzes the possibilities of arable soils for atmospheric CO2 sequestration by using modern agricultural technologies. Such possibilities are concluded to be very limited, as they increase the content of organic matter (OM) in the topsoil up to 0.1% С use until an OM equilibrium level is reached. For chernozems (Phaeozems) in the forest-steppe region this value accounts for not more than 10% of the soil organic carbon, lost since the soils started to be used for agricultural production till they reached equilibrium in carbon content. The reasons for the poor atmospheric carbon sequestration capacity of agricultural soils are explained, firstly, by a sharp, three-fold or more, decrease in the plant residues input to soils in comparison with undisturbed soils and, secondly, by the inability to firmly fix freshly formed humus substances: firm fixation of humus substances makes them inaccessible to soil microorganisms. It was shown that with the annual application of 14C labeled plant residues, soil carbon content stopped increasing already by the fifth year of the experiment, which indicated the establishment of a balance between carbon mineralization and fixation of 14C labeled compounds in soil. A preliminary conclusion was made that the ability to firmly fix freshly formed humus substances is an exclusive feature of undisturbed or abandoned arable soils. Arable land can play a significant role in atmospheric carbon sequestration only if abandoned after use. Such approach can be employed to a very limited extent on the lands that are not suitable any more for agricultural production.

A Non-Inflationary Potential Output in Question

The output gap measurement helps assess a country’s growth performance, fiscal space and to forecast inflationary pressures. It is measured based on the ‘potential output’. The latter captures the notion that there is an equilibrium level of production and policymakers try to reach an economic environment consistent with the operation of the economy at this equilibrium. This article put the non-inflationary potential output approach in question. This is because, a non-inflationary long term equilibrium would require in the short run a non-inflationary economic environment which entails, according to Phillips curve, a stable unemployment rate implying then that some people who can and are willing to work will not find jobs. The alternative methodology we proposed, to measure the potential output, and therefore the output gap, relied on the hypothesis that labor is the production factor that produces and uses capital as well as develops technology. Thus, the economy will reach its potential output when the unemployment rate is zero. This methodology enables to align macroeconomic policies objectives in order to support employment. The unemployed willingness to work won’t be offended by macroeconomic policies that put a non-inflationary equilibrium as an ultimate objective. Besides, this methodology suggests that; policies aiming to increase the labor force as well as policies aiming to increase the real productivity by worker can expand the production capacity of the economy i.e., its potential output. It also suggests that; policies aiming to reduce the unemployment rate can help the economy reach full employment i.e., its full capacity.