Cooperative Dynamics Research Articles

The Enduring Sino–Russian Strategic Relations of Mutual Dependence—The Attribute of Military Cooperation

ABSTRACT Beijing’s relatively ambiguous response to the Ukraine War has tested how firm the Sino—Russian strategic partnership is. This article aims to decipher the endurance and complexity of Sino-Russian strategic relations by evaluating the nature and dynamics of Sino-Russian defense cooperation amid the worsening international environment against both countries. By examining two Sino-Russian Joint Exercises and analyzing their joint military patrols, exercises, and technological projects, this article argues that the general Sino-Russian military collaboration has been enhanced. Beijing and Moscow have gradually strengthened the combat orientation of their military cooperation to deter the perceived third-party threat, solidify their strategic partnership and against the challenges posed by conflicting interests in the overall bilateral interaction. Both Beijing and Moscow consistently remain vigilant against the risks of abandonment and entrapment, emphasizing the importance of maintaining strategic autonomy and refraining from formal alliances. However, they confront the worst-case scenario of being simultaneously dragged into two separate armed conflicts by a shared adversary. Therefore, align with their own national interests, the ability of Beijing and Moscow to achieve a delicate equilibrium between avoiding entrapment and preventing abandonment will determine the vitality and long-term trajectory of their strategic partnership.

Network analysis of international cooperation in space 1958–2023: Evidence of space blocs

The future of international cooperation in outer space was questioned when, in January 2022, Russia announced that it intended to leave the International Space Station (ISS) in 2024. A symbol of post-Cold War reconciliation, the station has linked Washington and Moscow even when relations on the ground frayed. The ISS has become a bedrock of international cooperation, having welcomed 276 individuals from 22 countries since it was first put in orbit in 1998. Russia’s announced departure from the ISS alarmed proponents of international cooperation in space. Its actions, however, do not signal an end but a new phase in international cooperative dynamics in space. This article examines international cooperation in outer space from 1958 until 2023. Using network analysis, it quantifies cooperative relations between states on space matters to examine the current state of international cooperation in space and its evolving dynamics. It finds that international cooperation in space has become increasingly defined by the emergence of distinct clusters of states, termed ‘space blocs’. Recent patterns of international cooperation in space markedly deviate from past dynamics in three key aspects. First, since 2008, distinct, bound space blocs can be clearly detected. Second, the internal composition of recent space blocs has become increasingly reflective of geopolitical affinities and strategic considerations on the ground. Third, although highly bound and distinct, the more recent space blocs are not entirely isolated and have not instituted any exclusionary practices, which is promising for the future of international space cooperation.

Dynamics of collective cooperation under personalised strategy updates

Collective cooperation is essential for many social and biological systems, yet understanding how it evolves remains a challenge. Previous investigations report that the ubiquitous heterogeneous individual connections hinder cooperation by assuming individuals update strategies at identical rates. Here we develop a general framework by allowing individuals to update strategies at personalised rates, and provide the precise mathematical condition under which universal cooperation is favoured. Combining analytical and numerical calculations on synthetic and empirical networks, we find that when individuals’ update rates vary inversely with their number of connections, heterogeneous connections actually outperform homogeneous ones in promoting cooperation. This surprising property undercuts the conventional wisdom that heterogeneous structure is generally antagonistic to cooperation and, further helps develop an efficient algorithm OptUpRat to optimise collective cooperation by designing individuals’ update rates in any population structure. Our findings provide a unifying framework to understand the interplay between structural heterogeneity, behavioural rhythms, and cooperation.

An Alternative Explanation of the Microscopic Dynamics of Cyclic Polymers

AbstractAccording to recent reviews and experiments, some key dynamic properties of cyclic polymers from neutron spin echo spectroscopy, molecular dynamics simulations, and rheological measurements are at variance with the predictions from theories based on motions restricted by fixed obstacles. These dynamic properties including non‐Gaussianity, heterogeneity, and subdiffusive center of mass mean square displacements turn out to be hallmarks of cooperative dynamics found in entangled linear polymers, and in other many‐units interacting systems that are not polymers. The current situation suggests new theory emphasizing cooperative many‐chain dynamics is needed to explain the properties. The Coupling Model is such a theory. Its predictions are applied to the dynamic properties of cyclic polymers in this paper to show consistency with experiments and simulations.This article is protected by copyright. All rights reserved

Cue-driven microbial cooperation and communication: evolving quorum sensing with honest signaling

BackgroundQuorum sensing (QS) is the ability of microorganisms to assess local clonal density by measuring the extracellular concentration of signal molecules that they produce and excrete. QS is also the only known way of bacterial communication that supports the coordination of within-clone cooperative actions requiring a certain threshold density of cooperating cells. Cooperation aided by QS communication is sensitive to cheating in two different ways: laggards may benefit from not investing in cooperation but enjoying the benefit provided by their cooperating neighbors, whereas Liars explicitly promise cooperation but fail to do so, thereby convincing potential cooperating neighbors to help them, for almost free. Given this double vulnerability to cheats, it is not trivial why QS-supported cooperation is so widespread among prokaryotes.ResultsWe investigated the evolutionary dynamics of QS in populations of cooperators for whom the QS signal is an inevitable side effect of producing the public good itself (cue-based QS). Using spatially explicit agent-based lattice simulations of QS-aided threshold cooperation (whereby cooperation is effective only above a critical cumulative level of contributions) and three different (analytical and numerical) approximations of the lattice model, we explored the dynamics of QS-aided threshold cooperation under a feasible range of parameter values. We demonstrate three major advantages of cue-driven cooperation. First, laggards cannot wipe out cooperation under a wide range of reasonable environmental conditions, in spite of an unconstrained possibility to mutate to cheating; in fact, cooperators may even exclude laggards at high cooperation thresholds. Second, lying almost never pays off, if the signal is an inevitable byproduct (i.e., the cue) of cooperation; even very cheap fake signals are selected against. And thirdly, QS is most useful if local cooperator densities are the least predictable, i.e., if their lattice-wise mean is close to the cooperation threshold with a substantial variance.ConclusionsComparing the results of the four different modeling approaches indicates that cue-driven threshold cooperation may be a viable evolutionary strategy for microbes that cannot keep track of past behavior of their potential cooperating partners, in spatially viscous and in well-mixed environments alike. Our model can be seen as a version of the famous greenbeard effect, where greenbeards coexist with defectors in a evolutionarily stable polymorphism. Such polymorphism is maintained by the condition-dependent trade-offs of signal production which are characteristic of cue-based QS.

Smart Dynamic Pricing and Cooperative Resource Management for Mobility-Aware and Multi-Tier Slice-Enabled 5G and Beyond Networks

Smart Dynamic Pricing and Cooperative Resource Management for Mobility-Aware and Multi-Tier Slice-Enabled 5G and Beyond Networks

Social Integration of Foreign Immigrants in South Korean Local Communities

The article provides a comprehensive analysis of the evolving cooperative dynamics of immigrant policy in South Korea, emphasizing the interactions between central and local governments, as well as among various local authorities. It discusses the need to empower local governments with greater authority and responsibility in implementing immigrant policies, highlighting the importance of collaboration, coordination, and cooperation across multiple layers of governance. The article focuses on two case studies, the National Multicultural City Council (NMCC) and the Multicultural Immigrants Plus Center (MIPC), to illustrate the practical implications of this multi‐layered governance approach. The theoretical implications of the case studies are rooted in the concept of multi‐layered governance (MLG) and its application to immigrant policy governance, providing valuable perspectives for understanding and optimizing immigrant policy implementation across diverse socio‐political contexts.

Иран на пути к региональной интеграции: политические и экономические аспекты взаимоотношений с государствами-членами ШОС

The article examines Iran’s relationship with the Shanghai Cooperation Organization (SCO), analyses the process of establishing cooperation with the member states of this organization, primarily Russia and China, in the field of regional security, as well as the political and economic spheres. The history of Iran’s inclusion in the SCO, the dynamics of cooperation, as well as the impact of this interaction on regional and world politics are explored. The focus is on joint projects, diplomatic, trade and economic relations, as well as potential challenges and prospects for cooperation between Iran and the SCO. The work notes that Iran’s desire for full membership in this organization was reinforced by the confrontation with the leading Western powers led by the United States and fit into the framework of Eastern policy with the prospect of an alliance with Russia and China. It is emphasized that due to opposition to Iran’s desire to strengthen its independence and sovereignty, Western powers prevented its inclusion in the regional or international security architecture. Under these conditions, Iran has intensified its efforts in search of its place in the international security system, relying on the idea of national identity and drawing closer to Russia and China. It is noted that the negative consequences of sanctions, threats of military intervention, cyber warfare and attempts to destabilize the Islamic regime were the main methods of Western policy towards Iran. Based on this, accession to the SCO was considered by the Iranian leadership as the most important task to neutralize Western sanctions and become one of the leaders in the regional security system.

Repeated prisoner's dilemma games in multi-player structured populations with crosstalk

Crosstalk represents a ubiquitous phenomenon in which strategic moves made in one game can influence actions in another. Reiter et al. [1] first integrated crosstalk with the repeated prisoner's dilemma model in structured populations. We extend their strategic space from one-step reactive strategies that consider only the actions of the opponent to memory-one strategies that consider the actions of both parties. We explore the cooperation rate of some representative memory-one strategies in repeated prisoner's dilemma games for multi-player structured populations when crosstalk exists, and focus on finding evolutionarily stable strategies that are cooperative in the memory-one strategy space under the impact of crosstalk. Simulation results in the strategic dynamics show that appropriately forgiving defection is conducive to cooperative stability in the population when crosstalk exists. Specifically, for strategies that can promote cooperation, there is a mutual restriction between tolerating the behavior of both defecting (the focused player and his opponent both defecting, DD) and forgiving unilateral defecting (the focused player cooperating while his opponent defecting, CD). That is, a more forgiving behavior of CD requires a lower tolerance for DD, while a higher tolerance of DD requires a less forgiving behavior of CD. Notably, we find two effective strategies, namely, Win-Stay-Lose-Shift (WSLS) and Firm‑but-Fair (FBF) in the facilitation of cooperation in game dynamics with crosstalk. Moreover, we reveal that the structured population can better suppress the negative impact of crosstalk on cooperation. This investigation provides complementary insights into the interplay between strategic decision-making and the influence of crosstalk within the context of memory-one strategies.

Indonesia's Interests in the Pacific Region

Indonesia is a country that is located close to each other and has established diplomatic relations and cooperation with countries in the Pacific region. This is done to maintain national and regional stability. Indonesia has an interest in maintaining a stable, prosperous and friendly environment in the Pacific region. On the other hand, Pacific countries view Indonesia as an archipelagic country that has experience and capacity in terms of cooperation and development. This research aims to analyze Indonesia's interests in countries in the Pacific Region. These interests include: strengthening sovereignty, increasing economic & trade cooperation and partners supporting each other in regional and multilateral forums. The research results show that the dynamics of Indonesia's cooperation with countries in the Pacific region have gone well in recent years. Indonesia carries out a lot of cooperation in the form of training and capacity development for Pacific countries. Apart from that, Indonesia is also active in organizing activities and discussion forums to encourage increased relations and cooperation

Abstract 7378: Using game theory to investigate the therapeutic potential of disrupting tumor-microenvironment interactions

Abstract Cancer is a complex disease involving the interplay of several types of malignant and nonmalignant cells. The growth of tumors and surrounding stromal cells can be modeled as an ecosystem, where populations of cancerous and healthy cells interact and compete for resources. In this work, we have explored the application of game theoretic models of cancer to the design of novel anticancer therapies. Notably, a game theoretic-model of tumor-stromal interactions can capture the impact of interactions between cell types and can be used to investigate frequency-dependent parameters describing the impact of drug action during the initiation and growth of metastatic cancers. Previous studies using game theoretic models to describe cancer have focused on explaining progression patterns of specific tumors with known tumor-stromal interactions. This study takes a more general approach to cancer growth dynamics, modeling cancer as a simple game between healthy and cancer cells. This simplified model is used to make general predictions about cancer progression and the efficacy of treatment strategies. Our work suggests that disruption of beneficial interactions between healthy and cancer cells may be a viable treatment strategy for small tumors and preventing metastasis by ensuring that the healthy cell strategy is evolutionarily stable. The efficacy of treatment strategies that disrupt cancer cell cooperation or tumor-stromal dynamics changes as the cancer cell frequency changes. Our work suggests that drugs that target tumor-stromal cell interactions would need to be combined with other types of treatments to be effective against large tumors. Although based on a simplistic model of cancer initiation and progression, the framework derived here can be extended to the real-world design of experimental anticancer therapeutics, and fundamental analyses of this nature can be of practical utility in setting strategy for Target Product Profile design. Citation Format: Debra Van Egeren, Andrew Chen, Madison Stoddard, Lin Yuan, Arijit Chakravarty. Using game theory to investigate the therapeutic potential of disrupting tumor-microenvironment interactions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7378.

Particle swarm intelligence promotes cooperation by adapting interaction radii in co-evolutionary games

Particle swarm optimization (PSO), a population-based optimization algorithm inspired by swarm behaviors, has been applied extensively to simulate social behaviors such as migration, urban planning, or resource utilization. It capitalizes on the inherent principles of social cooperation, adaptability and learning from peers to help individuals in a population search for optima. In this work, we propose a novel co-evolutionary game model in which individuals adapt their interaction radii by applying the PSO algorithm and study how the learning factor ω in the algorithm shapes the cooperation dynamics. We find that the adaptive interaction radii based on PSO could significantly enhance cooperation, especially in the scenario with strong social dilemma. By studying the snapshots of strategy pattern and the distributions of interaction radii in the population, we further reveal that the PSO-based adapting mechanism can protect cooperators by shrinking the interaction radii in a severe environment with an appropriate ω. Nevertheless, when cooperation is favorable, the adaptation leads to a relatively wide distribution of interaction radii to facilitate the spread of cooperation. The results of this work highlight the potential of the PSO algorithm to resolve social dilemmas when combined with the evolutionary dynamics.

Abstract 3220: Osimertinib-induced epigenetic and transcriptional reprogramming drives a BRD4-POUF-PDGFRB-YAP-EMT axis of resistance in NSCLC

Abstract Acquired resistance to Osimertinib continues to pose a major limitation to achieving durable therapeutic responses in EGFR mutant non-small cell lung cancer (NSCLC). While multiple actionable genetic mutations have been identified as the underlying molecular basis of resistance, a genomic mechanism cannot be identified in >50% of Osimertinib resistant tumors and thus an effective combinatorial treatment strategy cannot be deployed for these patients. Recently, we identified YAP/TEAD activation and ERK1/2 reactivation as two major non-mutational counter-regulatory pathways that diminish the efficacy of Osimertinib, promoting establishment of the drug tolerant persister (DTP) and resistant states. Moreover, it is well known that cancer cells escape tyrosine kinase inhibitor (TKI) therapy by developing dependence on alternate, non-mutated receptor tyrosine kinases (RTKs) through a treatment-induced “RTK switch” phenomenon. The link however between alternate RTK signaling and YAP/TEAD/ERK1/2 has never been explored in the context of Osimertinib resistance. In this study, we systemically uncover transcriptional de-repression of, and critical dependence on PDGFRβ as part of a novel “RTK switch” mechanism deployed by cells to evade Osimertinib-induced death. Genetic or pharmacologic co-inhibition of PDGFRβ renders NSCLC cells more sensitive to Osimertinib during drug naïve, DTP and resistant phases of treatment through suppression of ERK1/2 reactivation, YAP activity/nuclear translocation and YAP-mediated induction of EMT factors, SLUG and Zeb2. Importantly, compared to Osimertinib alone, co-targeting EGFR and PDGFRβ robustly suppresses tumor regrowth following treatment cessation both in vitro and in vivo which is consistent with a reduction in the DTP cell population. These data auspiciously demonstrate a two-fold utility of concomitant PDGFRβ inhibition: to enhance the initial efficacy of Osimertinib and to eliminate the DTP and resistant cells following chronic Osimertinib treatment. Further mechanistic studies from integration of ATAC-seq, CUT&RUN and RNA-seq reveal that Osimertinib induces the dynamic cooperativity of chromatin modulator BRD4 with pluripotent POU-domain transcription factors Oct-4, Pit-1 and Brn-3 at putative proximal enhancer elements, facilitating upregulation of PDGFRβ. Collectively, we demonstrate a novel treatment-induced BRD4/POUF epigenetic/transcriptional mediated “RTK switch” that involves co-opting PDGFRβ signaling to activate YAP/TEAD and ERK1/2 as a means of driving adaptive resistance to Osimertinib. These data provide compelling rationale for combined anti-EGFR and PDGFRβ targeted therapy to improve patient outcomes. Citation Format: Antja-Voy Hartley, Caitlyn Weston, Simon Baldacci, William Feng, Mustafa Al-Dulaimi, Claudia Gentile, Matthew Booker, Michael Tolstorokuv, Cigall Kadoch, Pasi Janne. Osimertinib-induced epigenetic and transcriptional reprogramming drives a BRD4-POUF-PDGFRB-YAP-EMT axis of resistance in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3220.

Analysis of the Factors Affecting the Business Sustainability of Agricultural Cooperatives in Northern Mindanao

Cooperatives serve as cornerstones in the region's agricultural sector, supporting livelihoods, food security, and economic development. In examining the complex dynamics of agricultural cooperatives in Northern Mindanao, this analysis investigates the multifaceted factors that affect their business sustainability, shedding light on crucial determinants driving the region's agricultural cooperative landscape. The study used a descriptive correlational research design and used survey in gathering primary data. Findings revealed that the majority of the cooperatives have been operating for 21 years and above, more have members from 15 to 150, the majority have 1 to 9 employees, and the majority are micro-cooperatives. The results indicating an average mean distribution of management of cooperatives described as strongly affecting business sustainability, shed light on the critical role of effective management practices in ensuring the long-term viability of agricultural cooperatives. The study concluded that Management of Cooperatives is significantly correlated to Business Sustainability: People means are considered weak and positive relationships between the variables tested, and Profit means are described as strong. The Enterprise Characteristics are significantly correlated to Business Sustainability, People means are described as moderate and positive relationships between the variables tested, and Profit means are described as moderate. Implications: emphasize the need for cooperatives to strategically leverage their organizational characteristics to enhance business sustainability through targeted interventions in areas such as human resource management, innovation adoption, and value chain integration.

Unique Viscoelasticity and Hierarchical Relaxation Dynamics of Molecular Granular Materials.

Resulting from the dense packing of subnanometer molecular clusters, molecular granular materials (MGMs) are shown to maintain high elasticity far above their apparent glass transition temperature (Tg*). However, our microscopic understanding of their structure-property relationship is still poor. Herein, 1 nm polyhedral oligomeric silsesquioxanes (POSSs) are appended to a backbone chain in a brush configuration with different flexible linker chains. Assemblies of these brush polymers exhibit hierarchical relaxation dynamics with the glass transition arising from the cooperative dynamics of packed POSSs. The interaction among the assemblies can be strengthened by increasing the rigidity of linkers with the MGM relaxation modes changing from colloid- to polymer chain-like behavior, rendering their tunable viscoelasticity. This finally contributes to the decoupling of mechanical and thermal properties by showing elasticity dominant mechanical properties at a temperature 150 K above the Tg*.

EU arms collaboration, procurement, and offsets: the impact of the war in Ukraine

ABSTRACT In the last twenty years, the EU has made increasingly greater efforts to boost defence cooperation among MS. To strengthen the EDTIB and avoid duplication of capabilities, the EU has encouraged “European preference” in arms procurement and MS’ defence collaborative projects, also by seeking to expunge defence offsets from the single market. Against this backdrop, on 24 February 2022, Russia invaded Ukraine. What impact has the war in Ukraine had on EU defence cooperation? Has the war impacted MS in a similar fashion or unevenly, reinforcing defence integration dynamics for some, while kickstarting disintegration for others? Two years on, a thorough analysis of the impact of the war on EU defence cooperation is still missing. This paper fills this gap by exploring three levels of analysis – arms collaboration, arms procurement, and offsets – and by comparing pre-invasion evidence with data from the post-invasion period. The analysis suggests that the Russo-Ukrainian war has negatively impacted EU defence cooperation, potentially increasing both fragmentation and non-EU dependencies. However, although MS’ threat perception and their ability to reap industrial benefits remain important to explain EU defence cooperation, integration or disintegration dynamics do not neatly map onto the geographical or size divides identified by the literature.

Are Transboundary Water Events Reported Differently in French and English News for Conflict and Cooperation Dynamics?

Media coverage of water events in transboundary river basins reflects the views of both riparian countries and beyond, and the conflict and cooperation dynamics could be biased due to the linguistic diversity. The aim of this study is to investigate whether any deviation exists in the depiction of water conflict and cooperation dynamics as reflected in the sentiments of French and English news articles, taking the Lancang–Mekong River basin and the Nile River basin as case studies. The results showed that news articles in English itself can reflect the trends of the cooperative or conflictive sentiments of the water events occurring within the basin, but French news is complementary in examining the attitudes and values of a few countries towards the shared river. The study would serve as an important reference for the perspective analysis of all riparian countries, as well as a basis for comprehending water conflict/cooperation dynamics in multiple languages.

Opinion Mining on Social Media Text Using Optimized Deep Belief Networks

In the digital world, most people spend their leisure and precious time on social media networks such as Facebook, Twitter. Instagram, and so on. Moreover, users post their views of products, services, political parties on their social sites. This information is viewed by many other users and brands. With the aid of these posts and tweets, the emotions, polarities of users are extracted to obtain the opinion about products or services. To analyze these posts sentiment analysis or opinion mining techniques are applied. Subsequently, this field rapidly attracts many researchers to conduct their research work due to the availability of an enormous number of data on social media networks. Further, this method can also be used to analyze the text to extract the sentiments which are classified as moderate, neutral, low extreme, and high extreme. However, the extraction of sentiment is an arduous one from the social media datasets, since it includes formal and informal texts, emojis, symbols. Hence to extract the feature vector from the accessed social media datasets and to perform accurate classification to group the texts based on the appropriate sentiments we proposed a novel method known as, Deep Belief Network-based Dynamic Grouping-based Cooperative optimization method DBN based DGCO. Exploiting this method the data are preprocessed to attain the required format of text and henceforth the feature vectors are extracted by the ICS algorithm. Furthermore, the extracted datasets are classified and grouped into moderate, neutral, low extreme, and high extreme with DBN based DGCO method. For experimental analysis, we have taken two social media datasets and analyzed the performance of the proposed method in terms of performance metrics such as accuracy/precision, recall, F1 Score, and ROC with HEMOS, WOA-SITO, PDCNN, and NB-LSVC state-of-art works. The acquired accuracy/precision, recall, and F1 Score, of our proposed ICS-DBN-DGCO method, are 89%, 80%, 98.2%, respectively.

Examining the Coopetition Relationships in Renewable Energy Trade among BRI Countries: Complexity, Stability, and Evolution

The Belt and Road Initiative (BRI) has significantly transformed the traditional energy market and reshaped international cooperation and conflict dynamics through its expanding trade in renewable energy resources. This study focuses on examining the complex and evolving nature of coopetition relationships in the renewable energy trade among BRI countries from 2013 to 2020. Understanding the interplay between cooperation and competition in this sector is crucial for comprehending the dynamics and stability of these trade relationships. Using a signed network approach, the findings of this study reveal that the countries predominantly exhibit a cooperative relationship. However, as time progresses, a notable pattern emerges, characterized by the coexistence of “competitive cooperation” and “cooperative competition”. In addition, coopetition group clustering is strongly influenced by geographical location. China, as a key player in the BRI, demonstrates a coopetition group characterized by a high inflow and low outflow pattern. Furthermore, the implementation of the BRI has greatly improved the overall stability of trade along the route. However, the coexistence of competition and cooperation among nations has increased the uncertainty of trade relations, thereby exerting a certain level of influence on their stability. Based on these findings, this study proposes policy recommendations to strength renewable energy trade relationships along the BRI route.

Cooperative Dynamics of Highly Entangled Linear Polymers within the Entanglement Tube.

We present a quantitative comparison of the dynamic structure factors from unentangled and strongly entangled poly(butylene oxide) (PBO) melts. As expected, the low molecular weight PBO displays Rouse dynamics, however, with very significant subdiffusive center-of-mass diffusion. The spectra from high molecular weight entangled PBO can be very well described by the dynamic structure factor based on the concept of local reptation, including the Rouse dynamics within the tube and allowing for non-Gaussian corrections. Comparing quantitatively the spectra from both polymers leads to the surprising result that their spectra differ only by the contribution of classical Rouse diffusion for the low molecular weight melt. The subdiffusive component is common for both the low and high molecular weight PBO melts, indicating that in both melts the same interchain potential is active, thereby supporting the validity of the Generalized Langevin Equation approach.