External Constraints Research Articles

Impact of post-Dobbs abortion restrictions on maternal-fetal medicine physicians in the Southeast: a qualitative study

BackgroundThe US Supreme Court overturned federal abortion protections in Dobbs v. Jackson Women's Health Organization. Many states in the Southeastern US responded with restrictive policies that limit and criminalize abortion care. ObjectiveTo characterize the impacts of abortion restrictions on maternal fetal medicine physicians (MFMs) in the Southeastern US post Dobbs. Study DesignWe conducted qualitative, semi-structured interviews with 35 MFMs in 10 Southeastern states between February and June 2023. Our recruitment strategy relied on convenience and snowball sampling. Audio-recorded interviews were analyzed using Dedoose software and a descriptive qualitative approach that incorporated deductive and inductive approaches. ResultsEmergent themes were identified, and a conceptual framework was developed based on overarching themes. We found that abortion laws and external constraints following Dobbs resulted in ethical, professional, and legal challenges for MFMs that led to changes in clinical practice and deviations from patient-centered care. These forced changes resulted in negative impacts on MFMs such as increased fear, hypervigilance, and increased workload for MFMs. The changes also prompted concerns about health risks and negative emotional impacts for patients. Supportive colleagues, hospital systems, and policies were associated with decreased stress, emotional distress, and disruption of healthcare delivery. ConclusionsAbortion restrictions in the Southeastern US limit the ability of MFMs to provide or facilitate abortions in the setting of fetal anomalies and maternal health risk. MFMs perceived these restrictions to have negative professional and emotional repercussions for themselves, as well as negative impacts on patients. Supportive colleagues and clear guidance from hospital systems and departments on how to interpret laws were protective. Our findings have implications for the MFM workforce and patient care in the region.

Demographic Diversity and Economic Research: Fields of Specialization and Research on Race, Ethnicity, and Inequality

Using dissertation research topics found in the EconLit database and large-scale algorithmic methods that identify author demographics based on names, we explore the link between race and ethnicity and fields of economic research. We find that underrepresented racial and ethnic minority (URM) researchers are more likely to write dissertations in some unexpected subfields of economics but limited evidence that they are more likely to write dissertations on racial topics once we include basic controls. These descriptive results may be due to limitations in the data, intrinsic motivations, or external constraints.

Finite element analysis of acromial fracture after reverse total shoulder arthroplasty

BackgroundThe prevalence of acromial fracture after reverse total shoulder arthroplasty (RSA) is reportedly 2.6%-8.4%, and clinical outcomes differ among fracture sites. However, few studies have investigated the factors affecting fracture sites. This study aimed to reproduce acromial fractures after RSA by replicating the postoperative displacement of the humerus using finite element models (FEMs), and to investigate the effect of humeral displacement on the fracture site. MethodsSix patients (mean age, 76.3 ± 7.9 years; 5 women and 1 man) with acromial fractures after RSA treated at our institution were included. Among them, 3 had Levy Type 1 fractures, whereas the other 3 had Levy Type 2 fractures. Preoperative computed tomography data were used to create a 3-dimensional FEM. All elements within the proximal 2 cm of the clavicle and the scapular body were completely constrained. The entire humerus was forcibly displaced following its displacement after RSA, as measured by preoperative and postoperative computed tomography. The fracture sites, total displacement, external constraint of the humerus at the initial fracture, and bone density from the acromion to the scapular spine were investigated. Values of P < .05 were considered statistically significant in tests of statistical inference but were interpreted as reference values due to the small number of cases. ResultsThere were no major differences in humeral displacement between Type 1 and Type 2 fractures. Although the fracture sites in the FEM were slightly more medial than the actual fracture sites, they were similar. The total displacement and external constraint of the humerus at the initial fracture were similar in Type 1 and Type 2 fractures. The distribution of bone density from the acromion to the scapular spine differed between fracture types. ConclusionWe were able to reproduce acromial fractures after RSA by replicating humeral displacement using FEM. The extent and direction of humeral displacement may not significantly affect the acromial fracture site, whereas the bone density distribution from the acromion to the scapular spine may affect it.

Adapting to the market: leftist ideological justifications of liberal economic policies, 1977–1986

ABSTRACT Why do leftist forces accept, support and adopt free-market policies? To answer this question, we carry out a comparative study of left-wing groups (both parties and trade unions) in France, Italy and Spain during the late 1970s and the early 1980s. This period is widely acknowledged in international political economy to have represented a paradigm shift from post-war Keynesianism to neoliberal policy-making. We employ in-depth content analysis of memoirs, interviews to the press, opinion articles and policy-papers to explain actors’ positions on landmark policies implemented during such transition. In alignment with a developing literature in political economy (e.g. Mudge 2018), we find a proactive role of progressives in developing the ideological justification for the resort to liberal policies. However, we emphasise that widespread consensus among so-called progressives, rather than a leading role of technocrats or party experts, best explains such shifts. In this way, the paper casts doubts on interpretations of the liberalisation process that place excessive emphasis on the role of external constraints as well as on elite power. Drawing on Hall (1993), we argue that left-wing forces in the early 1980s have enacted a ‘second order change’, whereby policymakers use new instruments to meet existing policy objectives.

Kendala yang Dihadapi dalam Penerapan Dukcapil DiGi Mobile di Dinas Kependudukan dan Pencatatan Sipil Kota Pariaman

This research discusses the obstacles faced in implementing Dukcapil DiGi Mobile in Dukcapil Pariaman City. Effectiveness is a measuring tool to determine whether or not a predetermined target has been achieved. There are many factors that can influence effectiveness, both internal and external constraints. The presence of Dukcapil DiGi Mobile as an online service for population and civil registration services in Pariaman City aims to make it easier for the public to manage population administration effectively and efficiently. However, in its implementation there are still several obstacles in implementing Dukcapil DiGi Mobile. This research aims to determine the obstacles faced in implementing population document services through the DiGi Mobile application using Hansen and Mowen's theory which groups various kinds of obstacles into internal and external obstacles. The results of this research show what obstacles are faced in implementing Dukcapil DiGi Mobile in Dukcapil Pariaman City.

Fast finite-time time-varying formation tracking control of multi-agent systems with external disturbance and region constraints

In this paper, fast finite-time time-varying formation tracking control for second-order multi-agent systems with external disturbance and region constraints is investigated. The ubiquitous control input response delay is considered. A predictor-based state transformation is employed to obtain the ideal equivalent systems without control input response delay. Considering the difficulty of measuring external disturbance, a fast finite-time observer with the sliding mode technique is proposed to estimate the disturbance, which positively compensates the system. By adopting the sliding mode control strategy, a novel fast finite-time formation tracking controller is proposed. Sufficient conditions for the formation tracking control with region constraints are obtained. Numerical simulations are employed to validate the feasibility and effectiveness of the theoretical results.

How Do Developers Influence the Transaction Costs of China’s Prefabricated Housing Development Process? An Investigation through the Bayesian Belief Network Approach

The implementation of prefabricated housing (PH) has become prevalent in China recently due to its advantages in enhancing production and energy-saving efficiency within the construction system. However, stakeholders may not always fully realize the benefits of adopting PH due to the emergence of transaction costs (TCs) in the development process of such projects. This study investigated the strategies for developers to make rational choices for minimizing the TCs of the PH project considering their own attributes and external constraints. A Bayesian Belief Network model was applied as the analytical method, based on surveys conducted in China. A single sensitivity analysis indicated that developers influence the TCs of PH through the following three most impactful factors: prefabrication rate, PH experience, and contract payment method. Integrated strategies are recommended for developers in various situations based on a multiple sensitivity analysis. Developers facing challenges due to high prefabrication rates are advised to reduce the risks by procuring highly qualified general contractors and adopting unit-price contracts. For developers with limited PH experience, adopting the Engineering–Procurement–Construction procurement method is the most efficient way to reduce their TCs in the context of China’s PH market. This study contributes to the current body of knowledge concerning the effect of traders’ attributes and choices on TCs, expanding the application of TC theory and fulfilling the study on the determinants of TCs in construction management.

Time-optimal coordinated detumbling and pose adjusting control of a non-cooperative target with model uncertainties

In this paper, a novel post-capture takeover control strategy of non-cooperative target with model uncertainties by the dual-arm space manipulator is proposed. Two mission objectives of target detumbling and pose adjusting are comprehensively considered. First, the motion trajectory of the target is parameterized with normalized time by a Bezier shape-based function. On this basis, by considering the resultant external force and moment constraint and the model uncertainties of the target, the mission duration is optimized to obtain the time optimal detumbling and pose adjusting the trajectory of the target. Furthermore, the desired trajectory in manipulator joint space is obtained by introducing the arm angle inverse kinematics method, and a joint trajectory tracking controller is designed based on the feedback linearization theory to track the desired joint trajectory. Simulation results show that detumbling and pose adjusting can be simultaneously achieved by one control action, which verifies the effectiveness of the proposed integrated control strategy.

Strategy of Russian Military Cooperation with the Countries of the Arab Region

The article undertakes an analysis of the prospective domains of Russian military collaboration with Arab countries against the backdrop of geopolitical uncertainties. Despite maintaining its position as the second-largest arms exporter globally, Russia has experienced a proportional decline in its share of the global arms market. Nevertheless, a discernible uptick in the trade volume of conventional weaponry, coupled with cyclical enhancements in the tactical and technical attributes of military assets, reflects positive momentum in this sector. Amid prevailing external constraints and a noticeable scarcity of contemporary Russian weaponry in burgeoning segments of the arms market, Russia necessitates resolute and equitable measures to uphold and fortify collaborative ties with partner nations. Within this context, particular emphasis is placed on Russia's strategic military cooperation with Arab states, given the region's status as a focal point of geopolitical interests for major economies and a primary destination for arms imports.The article scrutinizes Russia's competitive standing in the arms and military equipment markets of the Arab world, acknowledging the region's significance as a pivotal importer of such goods. Employing a multifaceted evaluation encompassing absolute and relative statistical metrics and derived indices, the study assesses the region's role in global arms procurement. Moreover, it offers an appraisal of the existing state and potential avenues for enhancing the efficacy of the Russian-Arab military-technical collaboration framework. The discourse delves into the transformative prospects of this partnership within the framework of networkcentric warfare concepts. Furthermore, the article elucidates the principal risks inherent in military cooperation among nations at present, highlighting concerns regarding the possible manipulation of military-technical cooperation mechanisms to serve as leverage in furthering the geopolitical aspirations of specific stakeholders.In conclusion, the study posits forward-looking trajectories for bolstering bilateral relations, both sectorally and geographically. These include initiatives such as expanding licensing, leasing, offset transactions, and technology transfer initiatives; advocating for fifth-generation fighter aircraft and long-range radar detection and control systems, leveraging Industry 4.0 technologies; and prioritizing the training of foreign specialists.

A flexible, reusable and adjustable high-performance energy absorption system inspired by interlocking suture structures

Energy absorption systems play a very important role in impact protection under complex load conditions. However, traditional protective structures cannot adjust the mechanical properties on demand to accommodate variable load characteristics once manufactured. Therefore, inspired by the superior compression resistance of the diabolical ironclad beetle, a modular energy absorption system is developed by combining the efficient mechanical properties of thin-walled tubes and the robust connectivity of interlocking suture structures, which can be easily assembled from only bio-inspired tubes without external constraints. FEM simulations were performed to systematically investigate the static and dynamic mechanical properties of the developed system, and its crushing performance was demonstrated experimentally. Additionally, the influence of geometric parameters on the mechanical properties of the system has been investigated, and the insensitivity of secondary geometrical parameters and assembly defects has been verified, which shows that the system has a certain safety margin to avoid catastrophic accidents caused by fabrication defects. Moreover, the system exhibits excellent reusability under multi-impact load environments and its energy absorption capacity does not degrade after the primary impact. Furthermore, the system exhibits good designability thanks to the discrete modular structures, its mechanical properties can be tuned by stiffness design without affecting the energy absorption capacity, and its specific energy absorption can be effectively improved by lightweight design. This study provides a novel design strategy for the protection system applied in multiple complex environments.

Effect of the Brazilian corporate sustainability index on cash holdings and the moderating role of Covid‐19

AbstractThis study investigates the effect of the Brazilian Corporate Sustainability Index (ISE) on cash holdings and the moderating role of Covid‐19. Our sample comprises 213 non‐financial publicly listed firms from Brazil with 1072 firm‐year observations available on Refinitiv Eikon database from 2015 to 2022. Our overall findings show a positive association between ISE and cash holdings for the entire period analyzed. However, we find that ISE companies retained less cash in the pandemic period. Furthermore, external financial constraint is a channel through which ISE companies tend to lower their levels of cash holdings during the Covid‐19 outbreak. Our main results are robust to alternative measures of cash holdings. Therefore, we contribute to the corporate financial, sustainability, and Covid‐19 literature by providing the first empirical evidence of the dynamic nature of the relationship between ISE and cash holdings during external shocks and further comprehension to investors that sustainable practices reflected on the financial resource strategies are essential information during crises.

Research on Deployment Process Dynamics and Vibration for Replaceable Interface Mast

The mast of the rover is a device used to carry precision instruments such as cameras on the rover, and its performance directly affects the working quality of these devices. The replaceable interface mast can effectively solve the problems of a single structure and poor maintenance of ordinary masts, so we study the deployment process dynamics properties and vibration for replaceable interface mast. Firstly, we analyzed the spatial motion of the reconfigurable rigid body module by the absolute node coordinate method and the natural coordinate method, and established the dynamic equation of the interface, the reconfigurable module without external constraints. Then, we established a dynamic model of the mast system deployment process. We analyzed the dynamic behavior of the replaceable interface mast and studied and compared the differences in the deployment behavior of the replaceable interface mast under different system configurations, flexible interface geometric parameters, and different driving rules. Finally, we built a model of the mast system and experimentally analyzed the deployment process of the replaceable interface mast. Using numerical solution and experimental verification, we proved that the established dynamic model of the mast system can correctly analyze the deployment behavior dynamics of the replaceable interface mast, and the study can provide a reference for the design and behavior analysis of the mast system.

Predictor-based constrained fixed-time sliding mode control of multi-UAV formation flight

In this work, a predictor-based fixed-time sliding mode control is designed to tackle the problem of achieving precise trajectory tracking control of multiple unmanned aerial vehicle formation flight. The proposed approach simultaneously addresses various practical requirements, such as optimality, constraints, fixed-time convergence, external interferences, and computational burden. Initially, using the Taylor series concept, we derive the predictive models for the fixed-time sliding surface and reaching law. Subsequently, we formulate a constrained performance index by integrating these predictions with the control input. Ultimately, the optimal control input is computed through solving the constrained quadratic optimization problem. An outstanding feature of this study is the theoretical guarantee of closed-loop fixed-time system stability in the presence of external disturbances and constraints. Furthermore, the comparative analysis with sliding mode predictive control law and fixed-time sliding mode control methods demonstrates that the proposed approach achieves a straightforward control method with improved performance and acceptable accuracy. Finally, an experimental test is conducted to demonstrate the algorithm's potential for hardware implementation by employing the Hardware-in-the-Loop test.

Tracking control of chained non‐holonomic systems with asymmetric function constraints and external disturbance

AbstractFor a class of chain non‐holonomic systems with external disturbance and function constraints, the tan‐type barrier Lyapunov function is used to solve the constraints of the system, and then the non‐linear disturbance observer is used to deal with the disturbance so that the disturbance error eventually converges exponentially. The control strategy designed by the backstepping method can effectively ensure that signals are bounded without violating the respective constraints. Through the simulation design of a three‐stage wheeled mobile robot, the effectiveness of the control scheme is verified again by the results.

Fiscal Policy from a Structural Economic Dynamics Approach with General Macroeconomica Constraint

The aim of this paper is to analyze how fiscal policy can affect per capita economic growth. Therefore, an extension of the model by Araujo and Lima (2007) was made, by considering the public sector taxation and public expenses. Our findings corroborate the fact that positive public savings relieve the external constraint. We demonstrate that sectoral public spending growth rate and sectoral public taxes growth rate can affects economic growth. Still, it shows that the rate of economic growth is sensitive to the sectoral composition of public spending and taxation. Finally, a computer simulation is presented.

Italy, 1982: the case for Ecu-denominated Treasury bonds

In 1982 Italy issued ecu-denominated Treasury bonds: the first of a series of issues—followed by Spain, Greece, and France only in the second half of the 1980s—officially aiming at contributing to reduce inflation and ease trading agents with foreign payments. In fact, it was much more than this. It was a small but significant signal that an economic elite was committed to curbing ever-demanding and opaque political pressures to increase public spending and trade-unions to raise wages, both deemed as crucial flaws to be fixed before international competitiveness could be restored. It represented one building block of a wider strategy concerning the use of the external constraint in domestic policymaking and in the attempt to increase the role of Italy in the making of European integration. The paper aims to reconstruct the interconnections between the events that accompanied such choice and the theoretical and intellectual background of the group of key economists that implemented this strategy.

Examining shifts in the Angola–China relations in the post-dos santos era

Abstract The Angola–China connection has famously been branded a ‘marriage of convenience’—an ‘uneasy alliance’ forged for pragmatic reasons at an opportune time of mutual need. In this article, we document how the relationship has more recently undergone a marital burnout of sorts. Chinese loans to Angola have dried up and most Chinese state-owned enterprises have left, as have 90 percent of Chinese migrants. The legacy of this marriage is somewhat mixed. Much of the infrastructure left behind is of dubious quality, while servicing the Chinese debt incurred to finance these projects may consume up to 10 percent of Angola’s GDP. Drawing on three rounds of fieldwork in Angola and over 60 interviews, we trace the souring of Angola–China ties to three concomitant factors: (i) Angolan internal politics; (ii) Chinese reconfiguration; and (iii) exogenous shifts in the global economy. In doing so, we argue that China and Angola are entering new territory, and that this shift in both parties’ calculations can be usefully illuminated by the concept of ‘strategies of extraversion’. Angola’s elites have once again proven that they are adept at transforming external constraints—this time related to China’s increasing financial caution and domestic recalibration—into new opportunities.

A choice for Europe, a choice for growth? The Bank of Italy, the Pandolfi Plan and the European Monetary System, 1977-1979

The creation of the European Monetary System (EMS) between 1977 and 1979 introduced an element that would become central to Italy's strategy of adjustment to the macroeconomic shocks of the 1970s: the ‘external constraint', a political device — albeit with a technocratic matrix — designed to reduce public debt and enhance the country's economic competitiveness.Conceived by an economist at the Bank of Italy, Tommaso Padoa-Schioppa, in 1978, the reforms of the ambitious programme known as the Pandolfi Plan were designed to restore the competitiveness of the Italian economy. The plan described the main features of the lira's entry into the EMS as an external constraint, based on indications from the Bank of Italy's Director General Carlo Azeglio Ciampi and despite objections from Governor Paolo Baffi.At that juncture, the Bank of Italy consciously assumed the role of substitute that would characterise its action in the following decade, motivating and orienting the country's political choices in favour of an ever more urgent economic and monetary integration of Europe, towards what would finally be formalised with the Maastricht Treaty. Consistently with the structure of the EMS, the external constraint outlined in the Pandolfi Plan moved towards exchange rate constraints related to public finances and to the phenomena of fiscal dominance typical of monetary policy in Italy; it was essentially transformed into a fiscal policy constraint formally recognised in July 1981, with the so-called divorce between the Bank of Italy and the Treasury. The classic external constraint related to the balance of payments accounts and foreign exchange rates remained unchanged towards the rest of the world, meaning that it had an economic and not a "legal" nature, as defined by Guido Carli in the early 1990s.

Waste discharge concentration and quadratic thermal radiation influences on time-dependent nanofluid flow over a porous rotating sphere

The nature of waste discharge concentration on time-dependent nanofluid flowing over a rotating sphere is examined in the conducted research. The linear and quadratic radiation influences are considered in the energy transport equation. The flow generation occurs due to a sphere’s revolution with time-dependent angular velocity. The term external pollutant concentration is modeled in the concentration equation. Titanium dioxide ( Ti O 2 ) nanoparticles are inserted into base-liquid water ( H 2 O ) . Similar variables are reported for the conversion of the problem. The converted problem is computed through the Runge–Kutta–Fehlberg (RKF) scheme. The study outcomes obtained from a numerical scheme are presented with the help of graphs. The rise in the linear and quadratic thermal radiation factors will enhance the thermal profile. Improvement in local pollutant external source and external pollutant source parameters will improve the concentration profile. The mass transfer rate will improve by adding the solid volume fraction and escalated values of local pollutant external source constraints.

Mapping the Growth of Supermassive Black Holes as a Function of Galaxy Stellar Mass and Redshift

The growth of supermassive black holes is strongly linked to their galaxies. It has been shown that the population mean black hole accretion rate ( BHAR¯ ) primarily correlates with the galaxy stellar mass (M ⋆) and redshift for the general galaxy population. This work aims to provide the best measurements of BHAR¯ as a function of M ⋆ and redshift over ranges of 109.5 < M ⋆ < 1012 M ⊙ and z < 4. We compile an unprecedentedly large sample with 8000 active galactic nuclei (AGNs) and 1.3 million normal galaxies from nine high-quality survey fields following a wedding cake design. We further develop a semiparametric Bayesian method that can reasonably estimate BHAR¯ and the corresponding uncertainties, even for sparsely populated regions in the parameter space. BHAR¯ is constrained by X-ray surveys sampling the AGN accretion power and UV-to-infrared multiwavelength surveys sampling the galaxy population. Our results can independently predict the X-ray luminosity function (XLF) from the galaxy stellar mass function (SMF), and the prediction is consistent with the observed XLF. We also try adding external constraints from the observed SMF and XLF. We further measure BHAR¯ for star-forming and quiescent galaxies and show that star-forming BHAR¯ is generally larger than or at least comparable to the quiescent BHAR¯ .