Stable System Research Articles

Theory of high-temperature superfluorescence in hybrid perovskite thin films.

The recent discovery of high-temperature superfluorescence in hybrid perovskite thin films has opened new possibilities for harnessing macroscopic quantum phenomena in nanotechnology. This study aimed to elucidate the mechanism that enables high-temperature superfluorescence in these systems. The proposed model describes a quasi-2D Wannier exciton in a thin film that interacts with phonons via the longitudinal optical phonon-exciton Fröhlich interaction. We show that the super-radiant properties of the coherent state in hybrid perovskites are stable against perturbations caused by the longitudinal optical phonon-exciton Fröhlich interaction. Using the multiconfiguration Hartree approach, we derive semiclassical equations of motion for a single-exciton wavefunction, where the vibrational degrees of freedom interact with the Wannier exciton through a mean-field Hartree term. Super-radiance is effectively described by a non-Hermitian term in the Hamiltonian. The analysis was then extended to multiple excited states using the semiclassical Hamiltonian as the basic model. We demonstrate that the ground state of the model exciton Hamiltonian with long-range interactions is a symmetric Dicke super-radiant state, where the Fröhlich interaction is nullified. The additional density matrix-based consideration draws an analogy between this system and stable systems, where the conservation laws determine the nullification of the constant (momentum-independent) decay rate part. In the exciton-phonon system, nullification is associated with the absence of a momentum-independent component in the Wannier exciton-phonon interaction coupling function.

Establishment of transient and stable gene transformation systems in medicinal woody plant Acanthopanax senticosus

BackgroundTransient and stable gene transformation systems play a crucial role in elucidating gene functions and driving genetic improvement in plants. However, their application in medicinal woody plants has been hampered by inefficient procedures for isolating protoplasts and regenerating plants in vitro.ResultsEmbryogenic callus protoplast isolation and transient transformation system were successfully established. The highest yield of protoplasts was approximately 1.88 × 106 cells per gram with a viability of 90% under the combination of 1.5% cellulase and 0.2% macerozyme, with enzymatic digestion for 6 h in darkness followed by centrifugation at 400×g for 5 min. The transient transfection rate of protoplast reached 45.56% at a PEG 4000 concentration of 40%, a transfection time of 40 min, 16 h of dark incubation, a plasmid concentration of 1.5 ng μL−1, and 25 min heat shock at 45 °C. In addition, 15 Agrobacterium tumefaciens-mediated GUS-positive seedlings were obtained through the somatic embryogenetic pathway under the optimized conditions.ConclusionThis study successfully established both transient and stable genetic transformation systems, paving the way for future molecular biology research on A. senticosus.Graphical

Simplified control algorithm for stable and efficient standalone PV systems: An assessment based on real climatic conditions

This research addresses the critical challenge of optimizing efficiency and performance in solar photovoltaic (PV) systems. It focuses on duty cycle optimization of DC/DC converters for maximum power point tracking (MPPT). The study introduces an innovative hybrid MPPT solution that integrates a novel temperature-based single-sensor approach with an integral backstepping controller. This method precisely achieves the PV array's maximum power point (MPP) under varying weather conditions while optimizing the converter's duty cycle to best align with the MPP voltage. Comprehensive simulations in MATLAB/Simulink reveal that the hybrid method surpasses conventional MPPT systems in key metrics, achieving faster convergence time (below 0.66 ms), reduced power ripple (<0.3 W), and enhanced tracking efficiency (exceeding 97.67 %). Notably, experimental data validates the practical efficacy of the proposed system under real-world conditions in the context of El Jadida, Morocco. This integrated approach advances the theoretical understanding of MPPT optimization and demonstrates tangible improvements in PV system performance, offering significant potential for enhancing solar energy utilization in variable climate regions.

Efficient Plantlet Regeneration from Branches in Mangifera indica L.

Mango (Mangifera indica L.) is one of the most significant tropical and subtropical fruit species, with high ecological and economic value. However, research on the in vitro culture of mangoes is relatively weak, so establishing an efficient and stable mango plant regeneration system is of great significance. In this study, a preliminary mango regeneration system was established with Mangifera indica L. cv. Keitt from young branches as the starting explants. The results showed that the optimal plant growth regulator (PGR) formula for direct adventitious shoot induction on the branches was 1 mg/L 6-benzylaminopurine (6-BA) + 0.1 mg/L a-naphthaleneacetic acid (NAA), with an adventitious shoot induction rate of 73.63% and an average of 6.76 adventitious shoots. The optimal basal medium for adventitious shoot induction was wood plant medium (WPM), with an adventitious shoot induction rate of 63.87% and an average of 5.21 adventitious shoots. The optimal culture medium for adventitious shoot elongation was WPM + 1 mg/L 6-BA + 0.5 mg/L NAA, with an adventitious shoot elongation rate of 89.33% and an average length of 5.17 cm. The optimal formula for the induction of mango rooting was Douglas fir cotyledon revised medium (DCR) + 3 mg/L indole-3-butyric acid (IBA), with a maximum rooting rate of 66.13% and an average rooting quantity of 6.43. The genetic fidelity of the in vitro-regenerated plants was evaluated using inter-simple sequence repeat (ISSR) molecular markers. There was no difference between the in vitro-regenerated plants and the parent plant. This study provides an efficient and stable propagation system for Mangifera indica L., laying the foundation for its rapid propagation and genetic improvement.

Old drugs, new tricks: Delivering pitavastatin-loaded nanostructured lipid carriers for glioblastoma treatment

Glioblastoma (GB) is the most common and lethal primary form of malignant brain cancers. Its intrinsic aggressiveness and the blood-brain barrier (BBB) are two major factors that limit the efficacy of standard therapies. In recent years, nanostructured lipid carriers (NLCs) have established themselves as a promising avenue for improving drug delivery to the brain, overcoming the challenges associated with the low drug permeability of the BBB.This work delves into the systematic development of a novel carrier for pitavastatin delivery by establishing a “get it right at the first time” quality by design perspective, supported by multivariate analysis, computational modelling, and molecular docking. The manufacturing process was comprehensively evaluated at each step, from raw material selection to NLC purification, thus leading to a carrier with optimal colloidal, encapsulation and stability properties. The cytotoxic behaviour of the carrier was assessed in a panel of GB cell lines, which includes a low, a medium and a highly sensitive cell line to pitavastatin, providing a better discriminatory power and addressing the different potential in the therapeutic responses. The results obtained reflect a strong antiglioblastoma activity in concentrations where the standard of care lacks activity, as well as a swift and prominent internalization by GB cells. Overall, this work positions these long-term stable parenteral systems in line with the hypothesis of providing more effective surrogate therapeutics in the field of GB.

The logic of ambitious legislators in fluid party systems

AbstractClassic theories of political ambition assume relatively stable and programmatic party systems. However, in many parts of the world, ‘fluid’ or ‘inchoate’ party systems do not provide ambitious legislators with the electoral benefits associated with stable party brands. In this paper, we examine ambition in fluid party systems: What is the frequency of party switching for legislators who seek re‐election, and what are their characteristics? What incentives do parties create to push away or retain legislators? And which parties do ambitious legislators seek out? Using a systems approach, we argue that in fluid party systems, legislators' office‐seeking behavior is driven by their attitudes towards parties and their constituents, their prospective evaluation of party performance, and ideology. Incentives for politicians to switch parties act as negative feedback mechanisms which keep the party system stuck in a fluid state. We test the determinants of party switching using two data sources from Ecuador: a public records dataset of every legislator who earned re‐election from 1979 to 2021, and the Parliamentary Elites in Latin America (PELA) surveys of all legislators from 1994 to 2017. Both sources distinguish between switchers and non‐switchers. The results support the conclusion that ambitious legislators in fluid party systems are strategic actors that seek or keep parties to maximize their probability of re‐election—and thereby further exacerbate the party system's fluidity.

Thermal transfer performance and flow instability analysis of direct steam generation for parabolic trough solar collectors

Parabolic trough solar direct-steam-generation (DSG) technology is the enabling technologies to achieve low carbon future. However, actual inlet boundary and flow boiling instabilities pose challenge to safe operation. In this paper, the coupled optical-thermal-flow pattern model for DSG loops is built utilizing conservation equations, separated flow model and Lagrangian method. The heat transfer performance, hydrodynamic characteristics and two-phase flow law of the loop are discussed under the coupled variation of direct radiation intensity (DNI), mass flow (m), inlet temperature (Tin) and inlet pressure (Pin). The correlation between multi-condition, thermodynamic characteristics and flow instability is analyzed. The results show that increasing Pin, Tin and DNI have almost no effect on the intermittent state. The percentage of annular flow only remained stable (about 84.8%) when the steam mass was 1. Increasing DNI and Tin did not effectively improve the flow heat transfer, while increasing Pin worsened the flow heat transfer and increased the probability that the annular flow would turn into stratified flow but could reduce the pressure drop and the fluid vapor-liquid density difference and stabilizes its hydrodynamic properties. The simultaneous increase in m not only weakens this effect and strengthens the heat transfer, but also permanently reduces the probability of stratified flow. The higher the Pin, Tin and DNI, the lower the flow instability of the DSG system. Manual operation is recommended to prevent the system having flow instability in the morning due to the lower solar radiation intensity and inlet temperature when the system is started in the morning.

Explicit formulas for the asymptotic variance of a linearized model of a Gaussian disturbance driven power system with a uniform damping-inertia ratio

Serious fluctuations caused by disturbances may lead to instability of power systems. With the disturbance modeled by a Brownian motion process, the fluctuations are often described by the asymptotic variance at the invariant probability distribution of an associated Gaussian stochastic process. Here, we derive the explicit formula of the variance matrix for the system with a uniform damping-inertia ratio at all the nodes, which enables us to analyze the influences of the system parameters on the fluctuations and investigate the fluctuation propagation in the network. With application to systems with complete graphs and star graphs, it is found that the variance of the frequency at the disturbed node is significantly bigger than those at all the other nodes. It is also shown that adding new nodes may prevent the propagation of fluctuations from the disturbed node to all the others. Finally, it is proven theoretically that larger line capacities accelerate the propagation of the frequency fluctuation and larger inertia of synchronous machines help suppress the fluctuations of the phase differences, however, these acceleration and suppression are quite limited.

Interactions of human serum albumin with phosphate and Tris buffers: impact on paclitaxel binding and nanoparticles self-assembly

Aim To investigate the conformational changes in human serum albumin (HSA) caused by chemical (CD) and thermal denaturation (TD) at pH 7.4 and 9.9, crucial for designing controlled drug delivery systems with paclitaxel (PTX). Methods Experimental and computational methods, including differential scanning calorimetry (DSC), UV-Vis and intrinsic fluorescence spectroscopy, mean diameter, polydispersity index (PDI), ζ-potential, encapsulation efficiency (EE), in vitro release and protein docking studies were conducted to study the HSA denaturation and nanoparticles (NPs) preparation. Results TD at pH 7.4 produced smaller NPs (287.1 ± 12.9 nm) than CD at pH 7.4 with NPs (584.2 ± 47.7 nm). TD at pH 9.9 exhibited high EE (97.3 ± 0.2%w/w) with rapid PTX release (50% within 1h), whereas at pH 7.4 (96.4 ± 2.1%w/w), release only 40%. ζ-potentials were around −30 mV. Conclusion Buffer type and pH significantly influence NP properties. TD in PBS at pH 7.4, provided optimal conditions for a stable and efficient drug delivery system.

Nondeictic accusative and dative clitics and their variant forms in European and Brazilian Portuguese

Abstract This article raises the hypothesis that 3rd person, accusative o/a (“him/her”) and dative lhe (“to him”/ “to her”) clitics, as well as the indefinite clitic se (“one”), contrary to 1st and 2nd person me/te (“me/you”), were never part of the grammar of the populations who acquired Portuguese as L2 in Brazil; rather, 3rd person clitic pronouns have been learned by a small number of Brazilians with school access (0.5 %), in the beginning of the 19th century. To bring support to this hypothesis, socio-historical information is presented, according to which, during about 350 years of colonization, slaved Africans and their descendants constituted the largest part of the population; their contact with several waves of Portuguese immigrant workers contributed to the emergence of Brazilian dialects differing in many aspects from European Portuguese (EP). Data from European and Brazilian Portuguese (PB) popular theater plays, written across the 19th and the 20th centuries, show that EP exhibits a robust and stable system of 3rd person accusative and dative clitics, contrary to BP. Analyses of recorded EP and BP since the 1970s attest the extremely rare use of such clitics in BP, very close to the percentages shown in the more recent plays, whereas formal writing reveals the school relative success in the effort to teach 3rd person clitics.

Novel Endogenous Engineering Platform for Robust Loading and Delivery of Functional mRNA by Extracellular Vesicles.

Messenger RNA (mRNA) has emerged as an attractive therapeutic molecule for a plethora of clinical applications. For in vivo functionality, mRNA therapeutics require encapsulation into effective, stable, and safe delivery systems to protect the cargo from degradation and reduce immunogenicity. Here, a bioengineering platform for efficient mRNA loading and functional delivery using bionormal nanoparticles, extracellular vesicles (EVs), is established by expressing a highly specific RNA-binding domain fused to CD63 in EV producer cells stably expressing the target mRNA. The additional combination with a fusogenic endosomal escape moiety, Vesicular Stomatitis Virus Glycoprotein, enables functional mRNA delivery in vivo at doses substantially lower than currently used clinically with synthetic lipid-based nanoparticles. Importantly, the application of EVs loaded with effective cancer immunotherapy proves highly effective in an aggressive melanoma mouse model. This technology addresses substantial drawbacks currently associated with EV-based nucleic acid delivery systems and is a leap forward to clinical EV applications.

Distributed control and passivity‐based stability analysis for time‐delayed DC microgrids

AbstractFor cooperation among distributed generations in a DC microgrid (MG), distributed control is widely applied. However, the delay in distributed communication will result in steady‐state bias and the risk of instability. This paper proposes a novel distributed control for time‐delayed DC MGs to achieve accurate current proportional sharing and weighted average voltage regulation. Firstly, by utilizing an advanced observer based on the PI consensus algorithm, the steady‐state bias problem is addressed. Then, using the passivity theory, stability analysis is conducted to reveal the principle of system instability caused by communication delay. On this basis, to offset the adverse effects of communication delay on the system stability, scattering transformation is introduced in the observer‐based distributed control. Moreover, considering the potential delay from the measurement stage in real‐life scenarios, the sufficient condition of the system stability is concluded by constructing the Lyapunov–Krasovskii functional. Finally, the performance of the proposed control and conclusions of stability analysis are verified by hardware‐in‐loop tests.

AFTEA Framework for Supporting Dynamic Autonomous Driving Situation

The accelerated development of AI technology has brought about revolutionary changes in various fields of society. Recently, it has been emphasized that fairness, accountability, transparency, and explainability (FATE) should be considered to support the reliability and validity of AI-based decision-making. However, in the case of autonomous driving technology, which is directly related to human life and requires real-time adaptation and response to various changes and risks in the real world, environmental adaptability must be considered in a more comprehensive and converged manner. In order to derive definitive evidence for each object in a convergent autonomous driving environment, it is necessary to transparently collect and provide various types of road environment information for driving objects and driving assistance and to construct driving technology that is adaptable to various situations by considering all uncertainties in the real-time changing driving environment. This allows for unbiased and fair results based on flexible contextual understanding, even in situations that do not conform to rules and patterns, by considering the convergent interactions and dynamic situations of various objects that are possible in a real-time road environment. The transparent, environmentally adaptive, and fairness-based outcomes provide the basis for the decision-making process and support clear interpretation and explainability of decisions. All of these processes enable autonomous vehicles to draw reliable conclusions and take responsibility for their decisions in autonomous driving situations. Therefore, this paper proposes an adaptability, fairness, transparency, explainability, and accountability (AFTEA) framework to build a stable and reliable autonomous driving environment in dynamic situations. This paper explains the definition, role, and necessity of AFTEA in artificial intelligence technology and highlights its value when applied and integrated into autonomous driving technology. The AFTEA framework with environmental adaptability will support the establishment of a sustainable autonomous driving environment in dynamic environments and aims to provide a direction for establishing a stable and reliable AI system that adapts to various real-world scenarios.

From melt- to crystal-rich magmatic systems during rift localization: Insights from mineral chemistry in Central Afar (Ethiopia)

Magmatism plays a key role in accommodating and localizing extension during continental breakup. However, how the crustal magmatic systems evolve at the continental-ocean transition is poorly understood. We address these questions by studying the evolution of the magmatic system in the rift of Central Afar (Ethiopia), currently marking the transition from continental rifting to oceanic spreading. We focus on the voluminous and widespread Upper Stratoid Series (2.6–1.1 Ma) and the following Central Afar Gulf Series (1.1–0.6 Ma), the latter corresponding to localization of volcanism in narrow magmatic segments. We carried out the first systematic study of major and trace element mineral chemistry for these two Series and integrated it with geothermobarometry estimates and geochemical modeling, to reconstruct the evolution of the magmatic system architecture during rift localization. The Upper Stratoid magmas evolved by fractional crystallization in a melt-rich, moderately zoned, middle-lower crustal (10–18 km) magmatic system, from where they rose directly to the surface. Polybaric plagioclase convection and dissolution of a plagioclase-rich crystal mush is recorded in the phenocryst texture and chemistry. The Central Afar Gulf magmas evolved at similar depth in a more complex and dynamic storage system, with magma rising and mixing through multiple, relatively small, crystal-rich and interconnected reservoirs. Our study documents the transition during the continental breakup, from an overall stable and melt-rich magmatic system feeding the voluminous and homogeneous Upper Stratoid eruptions to a more dynamic, interconnected and crystal-rich situation feeding small-volume eruption while the rift localizes.

Command-filtered incremental backstepping attitude control of spacecraft with predefined-time stability

This paper investigates the predefined-time attitude tracking control problem within the theoretical framework of incremental dynamic inversion. The utilization of the Taylor series facilitates the transformation of the attitude control system into a discrete-time plant, with the control input expressed in an incremental form. Additionally, a novel predefined-time stable dynamics system is presented and incorporated into the disturbance observer designing process, serving the purpose of estimating lumped disturbance. It is also employed in a command filter design to approximate the derivatives of the virtual control law within a predefined time. Consequently, an incremental backstepping attitude tracking control scheme is further developed, integrating the proposed predefined-time disturbance observer to ensure the system's robustness and the predefined-time filter to address challenges related to “term explosion” and singularity problem. Rigorous Lyapunov analysis affirms that the attitude control system, when using the incremental backstepping controller, remains predefined-time stable. The effectiveness of the proposed control scheme is subsequently validated through numerical simulations.

Metal-organic frameworks and polymer nanoplatform: Biocompatible and photothermal responsive tribromoethanol anesthetic for mice

Effective anesthesia is crucial for ensuring the validity and reliability of animal experiments. In recent years, tribromoethanol has been widely used for small animal anesthesia. However, direct injection poses risks of overdose, anesthesia instability, and organ damage, affecting experimental reliability and animal welfare. Therefore, developing a safer and more stable delivery system for tribromoethanol is essential. In this study, we first synthesized two complexes using a solvothermal method. Then, we modified the traditional biopolymer PEG to synthesize an amphiphilic block copolymer, Cyanine 7-PEG-DDAT, which was used to coat CP1 and load tribromoethanol (TBE) for structural characterization. We then conducted biological tests on Cyanine 7-PEG-DDAT-CP1@TBE and compared its anesthetic effects in C57BL/6 mice with those of direct tribromoethanol injection. The results provide a reference for the application of tribromoethanol in mouse models and surgeries.

A genetically engineered mouse/human chimeric antibody targeting CD99 enhances antibody-dependent cellular phagocytosis against human mantle cell lymphoma Z138 cells

Background: Mantle cell lymphoma (MCL) is an aggressive form of B-cell nonHodgkin lymphoma. The elimination of MCL cells via phagocytosis is essential for cancer eradication. Therefore, discovering novel targeted antibodies that can induce phagocytosis is needed. We have demonstrated that our in-houseproduced mouse anti-CD99 mAb clone MT99/3 could induce potent anticancer activities against MCL cell lines in both in vitro and in vivo mouse xenograft models. Nevertheless, for use in humans, the mouse mAb needs to be transformed into a mouse/human chimeric mAb that contains a human Fc region to activate human immune effector functions, especially macrophage-mediated phagocytosis. Antibody-dependent cellular phagocytosis (ADCP) mediated by mouse/human chimeric mAb MT99/3 against MCL has not been previously reported. Objective: This study aimed to genetically engineer a mouse/human chimeric antibody against human CD99 derived from mouse mAb MT99/3 and to evaluate its effect in mediating the ADCP mechanism for eradicating MCL cells in vitro using monocyte-derived macrophages. Materials and methods: The expression plasmid to produce chimeric anti-CD99 antibody, ChAbMT99/3, was constructed by fusing the variable domains of mouse mAb MT99/3 with the constant domains of human IgG1 and the constant domains of kappa light chain. ChAbMT99/3 was expressed in the stable human expression system based on HEK293T cells. ChAbMT99/3 was purified from the culture supernatant of ChAbMT99/3-expressing HEK293T cells using Protein G chromatography. The purity and structure of ChAbMT99/3 were verified by SDS-PAGE and western blotting. The binding specificity and activity were determined by staining with cells expressing recombinant and native human CD99. The anticancer activity of ChAbMT99/3 in mediating the ADCP mechanism against MCL cell line Z138 using human monocytederived macrophages was evaluated. Results: We successfully constructed the plasmid to produce ChAbMT99/3. Human HEK293T cells stably expressing ChAbMT99/3 were established. The ChAbMT99/3- expressing HEK293T cells could secrete ChAbMT99/3 into the culture supernatant. The high purity and complete IgG structure of ChAbMT99/3 were obtained from the purification process. Crucially, this chimeric antibody retained its binding reactivity to recombinant and native human CD99. In addition, the produced ChAbMT99/3, upon binding to MCL cells, significantly enhanced ADCP against MCL cell line Z138 in a dose-dependent manner. Conclusion: The production of a mouse/human chimeric antibody against human CD99 derived from mouse mAb MT99/3 was successful. The engineered antibody could mediate ADCP activity against MCL cells. The produced ChAbMT99/3 might be a promising therapeutic candidate for MCL treatment.

Far-Field Phase-Shifting Structured Light Illumination Enabled by Polarization Multiplexing Metasurface for Super-Resolution Imaging.

The phase-shifting structured light illumination technique is widely used in imaging but often relies on mechanical translation stages or spatial light modulators, leading to system instability, low displacement accuracy, and limited integration feasibility. In response to these challenges, we propose and demonstrate an approach for generating far-field phase-shifting structured light using a polarization multiplexing metasurface. By controlling the polarization states of incident and transmitted light, the metasurface creates a three-step displacement of structured light, eliminating the need to move samples or illumination sources. As a proof of concept, we experimentally demonstrate microscopic imaging using structured light illumination generated by metasurfaces, extracting high-frequency information from objects, and surpassing the diffraction limit. The proposed metasurface platform offers a promising approach for developing compact and robust phase-shifting imaging systems, with broad prospects in quantitative detection, machine vision, and beyond.

Identification of flame transfer function and mechanism analysis of the influence of boundary impedance characteristics on thermoacoustic instability

Thermoacoustic instability is a common problem in the operation of modern gas turbines. The prediction of thermoacoustic instability and the clarification of its mechanism are the research focus and difficulty in the gas turbine industry. As a response function of flame to acoustic disturbance, flame transfer function is a key parameter in the study of thermoacoustic instability. In this paper, based on the scaled adaptive simulation (SAS) model combined with the eddy dissipation concept (EDC) combustion model, the time-domain flow field data are processed by the system identification method, and the results of flame transfer function extraction are in good agreement with the experimental values. Then, the detailed derivation process of the low-order thermoacoustic network model (LOTAN) is given to capture the behavior characteristics of the acoustic wave in the thermoacoustic system. On this basis, the effects of acoustic boundary conditions and hysteresis time on the thermoacoustic instability of the combustion system are analyzed, and the relationship between the mode shape, pressure, vibration velocity phase, and thermoacoustic instability is explored. It is found that the phase relationship between pressure and vibration mode can be used to determine the thermoacoustic instability of the system. This is of great practical significance for determining the thermoacoustic instability of the system and clarifying the internal mechanism of its generation and provides theoretical support for the subsequent thermoacoustic instability control.

Effects of Ethiopia’s landlocked status on ties with its neighbours

This study looks at Ethiopia’s landlocked status and the economic, security, and political implications for the country’s relations with its neighbors. Furthermore, it addresses potential threats arising from the implications as well as potential solutions. Ethiopia lost its sea outlet after 1991. As a result, it is incurring significant costs to cover port fees and other related costs. Ethiopia’s economy is suffering as a result of the high cost. A literature review is used as a source of data to investigate the implications of Ethiopia’s landlocked status in relation to its ties with neighboring countries. Books, journals, internet materials, and media outlets were consulted in this regard. Furthermore, a key informant interview was conducted to collect up-to-date data and information that supports the findings of the literature review. The security and political aspects are discussed in light of East Africa’s security, neighboring countries’ interests, and the presence of foreign powers in the region. This study underlines that Ethiopia’s landlocked status has implications for its security and political affairs. Ethiopia’s landlocked status is primarily due to the country’s political leadership. Ethiopia can deal with the consequences of its landlocked status by establishing a stable political system and developing a compatible economic policy. In this regard, Ethiopia should learn from other countries how to overcome the negative effects of landlockedness, as there are developed landlocked countries.