Top Partners Research Articles

Determining the Predictive Power of the Gravity Model: A Case for Zambia

Purpose: The purpose of this study was to determine the predictive power of the gravity model in explaining trade flows in Zambia. Materials and Methods: The study utilized panel data for the period 1990-2020 for the Zambian economy and its 15 top trading partners based on 2018 trade volumes. The data was collected from the Centre for Prospective Studies and International Studies for International Information (CEPII) Gravity Database. The study employed the gravity equation to predict trade flows in Zambia. Findings: The empirical results show that the gravity model accurately predicts Zambia's trade flows, with GDP positively and distance negatively correlated with exports. The results also show that sharing a common border enhances Zambia’s exports. Surprisingly, trade agreements exhibit a negative relationship with exports. Implications to Theory, Practice and Policy: The significant negative impact of distance on trade highlights the need for improved infrastructure and logistics to reduce transportation costs, thus, facilitating Zambia’s trade flows. Further, the findings suggest that Zambia should focus on strengthening trade with neighboring countries. Additionally, Zambia should diversify export bases away from heavy reliance on the mining sector. Besides, there is a need for active participation in regional integration initiatives to address implementation challenges of trade agreements.

The Effect of Exchange Rate Volatility on Trade between South Africa and her Top Trading Partners: Fresh Insights from ARDL and Quantile ARDL Models

The Effect of Exchange Rate Volatility on Trade between South Africa and her Top Trading Partners: Fresh Insights from ARDL and Quantile ARDL Models

Proteostasis perturbation of N-Myc leveraging HSP70 mediated protein turnover improves treatment of neuroendocrine prostate cancer

N-Myc is a key driver of neuroblastoma and neuroendocrine prostate cancer (NEPC). One potential way to circumvent the challenge of undruggable N-Myc is to target the protein homeostasis (proteostasis) system that maintains N-Myc levels. Here, we identify heat shock protein 70 (HSP70) as a top partner of N-Myc, which binds a conserved “SELILKR” motif and prevents the access of E3 ubiquitin ligase, STIP1 homology and U-box containing protein 1 (STUB1), possibly through steric hindrance. When HSP70’s dwell time on N-Myc is increased by treatment with the HSP70 allosteric inhibitor, STUB1 is in close proximity with N-Myc and becomes functional to promote N-Myc ubiquitination on the K416 and K419 sites and forms polyubiquitination chains linked by the K11 and K63 sites. Notably, HSP70 inhibition significantly suppressed NEPC tumor growth, increased the efficacy of aurora kinase A (AURKA) inhibitors, and limited the expression of neuroendocrine-related pathways.

Research on the Impact of Geopolitical Instability on Russian Trade

This study examines how global and country- specific geopolitical instability affects Russian trade using data from 1996 to 2021. A panel regression model analyzes trade between Russia and its 15 top trading partners, exploring both direct and indirect effects. The analysis focuses on how accumulated foreign direct investment (FDI) and exchange rate fluctuations mediate these relationships. The findings reveal that global geopolitical instability decrease Russian trade by 0.0558. Interestingly, this negative impact is partially mediated by a decrease in FDI (-0.0805). This aligns with the Structural Equation Modeling (SEM) results, which show a significant negative effect of global geopolitical instability on FDI (-1.209). This suggests that FDI acts as a key transmitter of the negative effects of global instability on Russian trade. The role of exchange rate fluctuations, however, is more complex. While the Sobel Test indicated a negative indirect effect, the SEM analysis shows a positive indirect effect through exchange rate fluctuations on trade. This suggests potentially countervailing effects of currency fluctuations, with depreciation potentially incentivizing exports while appreciation might make imports cheaper. The impact of country-specific geopolitical instability varies depending on the context. Industries like food products and textiles are significantly affected by geopolitical instability increase, while sectors such as fuels, metals and raw materials show resilience. Close trading partners are less affected by global instability but suffer from partner- specific instability. Geographically, Western Europe benefits from global instability but faces challenges from partner-specific instability, contrasting with Eastern Europe and Asia. Overall, this research contributes to the understanding of how geopolitical instability, mediated by FDI and exchange rates, shapes Russia's trade performance.

“They just forget about the students”: Growing resilient urban farmers with a research practice partnership

A sustainable transdisciplinary research network was established through a research practice partnership (RPP) between an urban farm, faculty and staff from a Historically Black College (HBC), and researchers at a medium-sized private university. We investigate student-worker resilience at this urban farm situated on the HBC campus, drawing on literature that explores tensions between informal learning environments and formal spaces, equitable food systems and farming systems, as well as the resilience of farm work, and which is grounded critical food systems education theory. Utilizing a participatory design approach, we conducted semi-structured interviews and deductively analyzed the data. The research questions guiding this paper are: (1) What topics of discussion are most important to the student-workers and staff working on an urban farm, (2) How do student-workers and college staff members perceive and experience resilience on an urban farm? We found that what participants on an urban farm discuss, relating to their experiences, include (1) how participants were eager to engage with the local community, (2) how participants demonstrated resilience while working on the urban farm, (3) how power dynamics played a pivotal role informing the direction of the urban farm, (4) how participants consider community access to healthy foods an important mission for the farm, (5) how the college acted as a power wielding entity, perpetuating its privilege over the farmers and the farm operations. These findings have the potential to enable community organizing spaces to promote resilience for their volunteers and workers, and for urban farms top partner with their community to promote the mission of increasing access to healthy and affordable food options.

TÜRKIYE'S FINANCIAL INTEGRATION AND EXPORT RELATIONSHIPWITH OECD COUNTRIES

Financial integration of countries is constantly increasing with their mutual trade. In other words, rising of partnership on international market ensure higher financial integration over time. Increasing of financial integration among countries also will be reason of raising the similarity and bilateral agreements of these countries. This paper shows that what countries have tendency to act together in terms of financial integration with Türkiye in the designated period. For this purpose, the stock market indexes of Belgium, France, Germany, Israel, Italy, Spain, Switzerland, and the United Kingdom those are top trading partner of Türkiye and members of the Organization for Economic Co-operation and Development (OECD) selected for this research. Gregory - Hansen (1996) cointegration test used to find the financial integration between the stock market indices of selected countries and Türkiye. The result of test method shows that the highest correlation is with Germany after Israel, and the second line is for the United Kingdom. According to result of the cointegration test, although Türkiye acts together with all selected countries, Germany stand on different point. This could explain with Germany is the major partner of Türkiye in terms of mutual trade.

Search for singly produced vectorlike top partners in multilepton final states with 139 fb−1 of pp collision data at s=13 TeV with the ATLAS detector

A search for the single production of a vectorlike top partner (T) with mass greater than 1 TeV decaying into a Z boson and a top quark is presented, using the full Run 2 dataset corresponding to 139 fb−1 of pp collisions at s=13 TeV, collected in 2015–2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a pair of electrons or muons with opposite-sign charges which form a Z-boson candidate, as well as by the presence of b-tagged jets and forward jets. Events with exactly two or at least three leptons are categorized into two independently optimized analysis channels. No significant excess above the background expectation is observed and the results from the two channels are statistically combined to set exclusion limits at 95% confidence level on the masses and couplings of T. The results are interpreted in several benchmark scenarios to set limits on the mass and universal coupling strength (κ) of the vectorlike quark. For singlet T quarks, κ values between 0.22 and 0.64 are excluded for masses between 1000 and 1975 GeV. For T quarks in the doublet scenario, where the production cross section is much lower, κ values between 0.54 and 0.88 are excluded for masses between 1000 and 1425 GeV. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

H→bs¯ decay and its implication for the vectorlike singlet fermion model

The vectorlike quark model is one of the extensions of the standard model (SM) of particle physics. The simplest version of this model introduces a vectorlike singlet quark which can mix with SM quarks and give rise to new contributions to the flavor-changing decays of the Higgs boson. In this work we first present a systematic analysis of the branching ratios of the decays H→bs¯,bd¯ at leading order in the standard model. Our results show that it is challenging to observe these two modes because of their small branching ratios. Then augmenting the SM with a vectorlike singlet top quark, assuming the top partner only mixes with the top quark, complete one-loop contributions are taken into account in the amplitudes. Further results indicate that the branching ratios of the decays H→bs¯,bd¯ are sensitive to the mass of the top partner MT and the mixing effects characterized by sinθL. By tuning the values of MT and sinθL, the branching ratios may rise to a level accessible to LHC experiments. Combined with the branching ratios obtained from a probabilistic model, the allowed areas in the MT−sinθL plane are displayed. Tagging efficiencies and feasibility for detecting H→bs¯ are specifically discussed and we conclude that with large statistics it is promising to discover the H→bs¯ decay at the LHC. Published by the American Physical Society 2024

Lattice investigations of the chimera baryon spectrum in the Sp(4) gauge theory

We report the results of lattice numerical studies of the Sp(4) gauge theory coupled to fermions (hyperquarks) transforming in the fundamental and two-index antisymmetric representations of the gauge group. This strongly coupled theory is the minimal candidate for the ultraviolet completion of composite Higgs models that facilitate the mechanism of partial compositeness for generating the top-quark mass. We measure the spectrum of the low-lying, half-integer spin, bound states composed of two fundamental and one antisymmetric hyperquarks, dubbed chimera baryons, in the quenched approximation. In this first systematic, nonperturbative study, we focus on the three lightest parity-even chimera-baryon states, in analogy with QCD, denoted as ΛCB, ΣCB (both with spin 1/2), and ΣCB* (with spin 3/2). The spin-1/2 such states are candidates of the top partners. The extrapolation of our results to the continuum and massless-hyperquark limit is performed using formulas inspired by QCD heavy-baryon Wilson chiral perturbation theory. Within the range of hyperquark masses in our simulations, we find that ΣCB is not heavier than ΛCB. Published by the American Physical Society 2024

Naturalness-motivated composite Higgs model for generating the top Yukawa coupling

The large top Yukawa coupling results in the top quark contributing significantly to the quantum correction of the Higgs mass term. Traditionally, this effect is canceled by the presence of top partners in symmetry-based models. However, the absence of light top partners poses a challenge to the naturalness of these models. In this paper, we study a model based on composite Higgs with the top Yukawa coupling originating from dimension-six four-fermion operators. The low cutoff scale of the top quark loop required by the naturalness principle can be realized with a light gauge boson Eμ that connects the hyperfermions and top quarks. A scalarless dynamical model with weakly coupled extended SU(4)EC gauge group is presented. The model features an Eμ boson and a ZE′ boson both at the sub-TeV scale, which lead to a rich phenomenology, especially in the top quark physics. Published by the American Physical Society 2024

Composite resonances at a 10 TeV muon collider

We investigate the reach for resonances of the composite Higgs models at a 10 TeV μ+μ− collider with up to 10 ab−1 luminosity. The strong dynamics sector is modeled by the minimal coset SO(5)/SO(4), where vector resonances are in (3, 1) of SO(4) and fermions are in (2, 2). Various production and decay channels are studied. For the spin-1 resonances, the projections are made based on the radiative return and vector boson fusion production channels. The muon collider can cover most of the kinematically allowed mass range and can measure the coupling gρ to percent level. For the fermionic resonances (i.e. the top partners), pair production easily covers the resonance mass below 5 TeV, while single production extends the reach to 6 TeV for a small ξ = 0.015.

Abstract 2770: A novel MIRO2/MYO9B/RhoA signaling axis controls tumor cell invasion and metastasis

Abstract Metastasis of cancer cells to vital organs remains the leading cause of cancer related deaths, emphasizing a strong need for actionable targets in advanced stage cancer. To address this, we study novel dysregulated mitochondrial signaling mechanisms that cells utilize to metastasize. Here, we focus on how outer mitochondrial membrane protein—Mitochondrial Rho GTPase 2 (MIRO2)—promotes tumor cell invasion and metastasis. Our previous work identified higher MIRO2 mRNA expression in cancer vs. normal patient samples in a multitude of cancer types, which correlated with worse patient outcomes. Furthermore, we demonstrated that MIRO2 was critical for prostate cancer cell growth and survival in vitro and in vivo. However, it remains unknown if MIRO2 only affects primary tumor growth or if this protein is important throughout tumor progression. Using siRNA mediated knockdown (KD) of MIRO2 we find MIRO2 KD ubiquitously reduces tumor cell invasion in breast, melanoma, pancreatic, and prostate cancer cells. Utilizing metastatic prostate and breast cancer models, we demonstrate that mice injected with MIRO2 shRNA cells have significantly lower metastatic burden compared to mice injected with control shRNA cells. To determine the mechanism that MIRO2 controls invasion and metastasis, we looked at which of the top protein-binding partners for MIRO2 may regulate tumor cell invasion. Of our top hits, we found that depletion of atypical myosin IXB (MYO9B) by siRNA most significantly reduced tumor cell invasion and phenocopied MIRO2 depletion. MYO9B has a well-defined role in controlling cell motility via inactivation of RhoA. Excitingly, we have found 1) MIRO2 KD results in increased active RhoA, phenocopying MYO9B KD, 2) dual ablation of MIRO2 and RhoA fully rescues tumor cell invasion, and 3) MIRO2 is required for MYO9B driven invasion. Taken together, we propose a novel signaling mechanism by which MIRO2 broadly promotes invasion and metastasis through MYO9B dependent inactivation of RhoA. Citation Format: Dillon P. Boulton, Connor J. Hughes, Valentina Vaira, Ajita Jindal, Masoom Raza, Stephen Connor Purdy, Shilpa Sant, Heide L. Ford, M. Cecilia Caino. A novel MIRO2/MYO9B/RhoA signaling axis controls tumor cell invasion and metastasis [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 2770.

CHINA-US STRATEGIC COMPETITION AND ITS IMPACTS ON AGRICULTURAL COOPERATION: AN ANALYSIS OF PAKISTAN AND UKRAINE

This article aims to examine the China-US strategic competition and its impacts on agricultural cooperation between the two powers. Over the past two decades, China`s comprehensive influence across the world has challenged the US hegemony that it has held for three decades. The US perceives China`s persistent economic growth and diplomatic influence as the main challenge to its supremacy in the world. The strategic competition between the two powers has also resulted in a trade war in recent years. China has been one of the top trading partners for the past two decades. Since, the early 2000s, China has been one of the main countries for the US for its agriculture exports. In the same way, the US remains to be an important destination for Chinese agricultural exports. The China-US strategic game not only caused a consequential distraction to the agricultural trade, but it also had direct negative impacts on the economies of the two countries. This article finds that agriculture is a key area of China-US trade relations and that the strategic competition between the two powers has direct implications for the agricultural sector. The findings of this research also revealed that the US-China trade war has hindered agriculture cooperation, and has implications for Ukraine and Pakistan as well.

Trade Integration of India with South and Central Asia: Evidence from Gravity Model

The present study investigates exports of India with selected South and Central Asian countries and their top trade partners. The panel data from 1996–2020 is used and PPML estimation technique which takes care of heterogeneity, zero trade and endogeneity is applied. In addition to basic variables, institutional setup in selected countries is included in the model to get better results. To check robustness of results, in addition to PPML, Heckman selection model is also estimated. The findings indicate that institutions play an important role in export promotion of India to these countries. Among various institutional factors, effectiveness of government in different aspects has considerable influence on exports from the country. The study concludes that institutional quality needs to be improved to enhance trade cooperation of India with these countries.

A KEY PARTNER ONLY NOW? THE PRESENT-CENTREDNESS IN KOREA’S VIEWS OF ITS ECONOMIC RELATIONS WITH SOUTHEAST ASIA

Common public narratives in South Korea note that “Southeast Asia has recently emerged as its key economic partner.” Yet, these accounts are typically presented only with recent economic statistics and are largely devoid of context or nuance. In particular, they lack consideration of historical references, creating the impression that Korea-Southeast Asia ties are only a “recent” development. This “presentist” tendency is not only ahistorical in itself, but it may also produce a misleading appreciation of South Korea’s relations with Southeast Asia. By reviewing statistical information relevant to Southeast Asia’s economic importance to South Korea, particularly in trade and foreign direct investment, this article shows that SE Asia became Korea’s top economic partner at a much early point in time. It also discusses the factors that may have contributed to the popularity of such a presentist view in the public conscience.

New physics in single resonant top quarks

Searches for new physics in the top quark sector are of great theoretical interest, yet some powerful avenues for discovery remain unexplored. We characterize the expected statistical power of the LHC dataset to constrain the single production of heavy top partners T decaying to a top quark and a photon or a top quark and a gluon. We describe an effective interaction which could generate such production, though the limits apply to a range of theoretical models. We find sensitivity to cross sections in the 102 − 105 fb range, for T masses between 300 and 1000 GeV, depending on decay mode.

SOX11 is a novel binding partner and endogenous inhibitor of SAMHD1 ara-CTPase activity in mantle cell lymphoma

AbstractSterile alpha motif and histidine-aspartate (HD) domain–containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate triphosphohydrolase with ara-CTPase activity that confers cytarabine (ara-C) resistance in several hematological malignancies. Targeting SAMHD1’s ara-CTPase activity has recently been demonstrated to enhance ara-C efficacy in acute myeloid leukemia. Here, we identify the transcription factor SRY-related HMG-box containing protein 11 (SOX11) as a novel direct binding partner and first known endogenous inhibitor of SAMHD1. SOX11 is aberrantly expressed not only in mantle cell lymphoma (MCL), but also in some Burkitt lymphomas. Coimmunoprecipitation of SOX11 followed by mass spectrometry in MCL cell lines identified SAMHD1 as the top SOX11 interaction partner, which was validated by proximity ligation assay. In vitro, SAMHD1 bound to the HMG box of SOX11 with low-micromolar affinity. In situ crosslinking studies further indicated that SOX11-SAMHD1 binding resulted in a reduced tetramerization of SAMHD1. Functionally, expression of SOX11 inhibited SAMHD1 ara-CTPase activity in a dose-dependent manner resulting in ara-C sensitization in cell lines and in a SOX11-inducible mouse model of MCL. In SOX11-negative MCL, SOX11-mediated ara-CTPase inhibition could be mimicked by adding the recently identified SAMHD1 inhibitor hydroxyurea. Taken together, our results identify SOX11 as a novel SAMHD1 interaction partner and its first known endogenous inhibitor with potentially important implications for clinical therapy stratification.

SOX11 is a novel binding partner and endogenous inhibitor of SAMHD1 ara-CTPase activity in mantle cell lymphoma.

The sterile alpha motif and histidine-aspartate (HD) domain containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate triphosphohydrolase with ara-CTPase activity that confers cytarabine (ara-C) resistance in several haematological malignancies. Targeting SAMHD1's ara-CTPase activity has recently been demonstrated to enhance ara-C efficacy in acute myeloid leukemia. Here, we identify the transcription factor SRY-related HMG-box containing protein 11 (SOX11) as a novel direct binding partner and first known endogenous inhibitor of SAMHD1. SOX11 is aberrantly expressed not only in mantle cell lymphoma (MCL), but also in some Burkitt lymphomas. Co-immunoprecipitation of SOX11 followed by mass spectrometry in MCL cell lines identified SAMHD1 as the top SOX11 interaction partner which was validated by proximity ligation assay. In vitro, SAMHD1 bound to the HMG box of SOX11 with low-micromolar affinity. In situ crosslinking studies further indicated that SOX11-SAMHD1 binding resulted in a reduced tetramerization of SAMHD1. Functionally, expression of SOX11 inhibited SAMHD1 ara-CTPase activity in a dose-dependent manner resulting in ara-C sensitization in cell lines and in a SOX11-inducible mouse model of MCL. In SOX11-negative MCL, SOX11-mediated ara-CTPase inhibition could be mimicked by adding the recently identified SAMHD1 inhibitor hydroxyurea. Taken together, our results identify SOX11 as a novel SAMHD1 interaction partner and its first known endogenous inhibitor with potentially important implications for clinical therapy stratification.

The Effect of Ukraine-Russia War on the Economies of Ukraine’s Top Trading Partners

This research paper studies the impact of the Ukraine-Russia war on the economies of Ukraine’s top trading partners. Several earlier studies have examined the implications of the war for global trade and development, and how countries highly dependent on exports from the conflict region have responded. In our paper, we focused only on Ukraine, analyzed both import and export partners of Ukraine, and developed a framework to assess the impact of the war on various macroeconomic indicators for these partner countries. In particular, we established Difference-in-Difference based statistical models for Gross Domestic Product (GDP), food inflation, manufacturing production, gasoline prices and changes in inventories the for partner and non-partner countries over the pre-war and post-war years from 2021 through 2023. Our findings contribute to a better understanding of the devastating and far-reaching economic effects of the Ukraine-Russia war that serve as a cautionary tale for world citizens and leaders alike.

Impact of Nigeria-China relations on development in Nigeria, 2010-2020

Nigeria-China relations had a considerable influence on Nigeria's development, and the Peoples Republic of China emerged as one of Nigeria's primary commercial partners and a major source of foreign direct investment (FDI) in recent decades. To this, the relationship between the two nations has influenced Nigeria's growth in various ways, especially in the area of infrastructure development obtained through loans, investments, skills and technology transfer. China has contributed to the development of Nigeria’s infrastructure, thus, fostering economic growth in addition to influencing regional integration. Furthermore, in the energy and power sectors, Chinese firms have been involved in the construction of power plants, transmission lines, and renewable energy projects in Nigeria aimed at addressing power deficits and improving access to electricity, which is essential for industrial development and improving Nigerians' quality of life. China is one of Nigeria's top commercial partners and a substantial source of foreign direct investment (FDI). Chinese enterprises working in Nigeria have provided technology, skills, and knowledge transfer that has benefited Nigerian industries. Chinese investments in industries like telecommunications, manufacturing and agriculture have eased the transfer of technical skills while also increasing efficiency in production methods. This paper aims to illustrate the importance of bilateral trade relations as a means of change and development especially when the nations involved are in need of each other. The paper adopts qualitative approach to the study of international relations. The paper adopts dependency theory to analyze bilateral trade relation between Nigeria and China. The theory believes that trade should only be done to enhance prosperity and also argued that the principle of comparative advantage ensures everyone would profit from the interaction. The paper reveals and concludes that Nigeria-China relations have made a substantial impact on Nigeria's economic development notwithstanding some notable deficiencies that have arisen in areas of unfair labour practices amongst others