Hierarchical spatial segregation of two Mediterranean vole species: the role of patch-network structure and matrix composition

Introduction: Stiffening of the central vasculature is a strong and independent predictor of adverse cardiovascular events. Vascular stiffening is a complex process that involves changes in the vessel wall composition and smooth muscle cell (SMC) function. We recently used an unbiased proteomic approach to identify Lysyl oxidase like 2 (LOXL2) as a potential new target in vascular stiffness. The goal of this study is to characterize the role of LOXL2 in vascular stiffening and its potential as a target to reverse vascular stiffness associated with hypertension. Results: We demonstrate that decreased nitric oxide (NO) bioavailability results in increased secretion and activity of LOXL2 in SMCs. LOXL2 knockdown markedly attenuates SMC adhesion, motility, and proliferation and results in diminished matrix deposition. LOXL2 knockdown also results in striking changes in the stiffness and cytoskeletal remodeling events in CMSs. Tensile testing shows that intact aortas of LOXL2+/- animals are stiffer when compared with those from wild type mice, while there is no difference in decellularized vessels. We next investigated the role of LOXL2 in the development of hypertension using angiotensin II (AngII) infusion in LOXL2+/- (group 1) and wild type (WT; group 2) mice. BP and pulse wave velocity (PWV) increased significantly with AngII infusion in both groups during the study period, without a significant change in heart rate. Compared to WT animals, contractile responsiveness was markedly diminished in LOXL2+/- animals at baseline as well as with AngII infusion when compared with untreated controls. The NO- dependent vasodilatory response to acetylcholine was identical at baseline and diminished significantly with AngII infusion in both groups of animals. There was no difference between the groups in the endothelium-independent response to sodium nitroprusside. Conclusion: In this study, we demonstrated the role of NO in the regulation of LOXL2. Interestingly, LOXL2 appears to have a dual role in vascular stiffness by affecting both SMC function as well as matrix composition. We therefore conclude that LOXL2 is a novel target involved in vascular stiffness that requires further characterization to elicit the possibility of therapeutic intervention.

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Promoting cooperation by preventing exploitation: The role of network structure

Physical Review E ◽

10.1103/physreve.96.022315 ◽

2017 ◽

Vol 96 (2) ◽

Cited By ~ 3

Author(s):

Zoran Utkovski ◽

Viktor Stojkoski ◽

Lasko Basnarkov ◽

Ljupco Kocarev

Keyword(s):

Network Structure

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Mitochondrial fission is required for proper nucleoid distribution within mitochondrial networks

10.1101/2021.03.17.435804 ◽

2021 ◽

Author(s):

Hema Saranya Ilamathi ◽

Mathieu Ouellet ◽

Rasha Sabouny ◽

Justine Desrochers-Goyette ◽

Matthew A Lines ◽

...

Keyword(s):

Mitochondrial Dna ◽

Network Structure ◽

Mitochondrial Fission ◽

Healthy Population ◽

Primary Cells ◽

Mitochondrial Homeostasis ◽

Mtdna Replication ◽

Mitochondrial Networks ◽

Regular Spacing

Mitochondrial DNA (mtDNA) maintenance is essential to sustain a functionally healthy population of mitochondria within cells. Proper mtDNA replication and distribution within mitochondrial networks are essential to maintain mitochondrial homeostasis. However, the fundamental basis of mtDNA segregation and distribution within mitochondrial networks is still unclear. To address these questions, we developed an algorithm, Mitomate tracker to unravel the global distribution of nucleoids within mitochondria. Using this tool, we decipher the semi-regular spacing of nucleoids across mitochondrial networks. Furthermore, we show that mitochondrial fission actively regulates mtDNA distribution by controlling the distribution of nucleoids within mitochondrial networks. Specifically, we found that primary cells bearing disease-associated mutations in the fission proteins DRP1 and MYH14 show altered nucleoid distribution, and acute enrichment of enlarged nucleoids near the nucleus. Further analysis suggests that the altered nucleoid distribution observed in the fission mutants is the result of both changes in network structure and nucleoid density. Thus, our study provides novel insights into the role of mitochondria fission in nucleoid distribution and the understanding of diseases caused by fission defects.

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THE ROLE OF SOCIAL CAPITAL AND INTERPERSONAL RELATIONS IN THE ALLEVIATION OF EXTREME POVERTY AND SPATIAL SEGREGATION OF ROMANI PEOPLE IN SZEGED

Journal of Urban and Regional Analysis ◽

10.37043/jura.2017.9.1.2 ◽

2020 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Boglárka MÉREINÉ BERKI ◽

György MÁLOVICS ◽

Janka TÓTH ◽

Remus CREŢAN

Keyword(s):

Social Capital ◽

Social Mobility ◽

Poverty Alleviation ◽

Interpersonal Relations ◽

Social Institutions ◽

Spatial Segregation ◽

Extreme Poverty ◽

Urban Underclass ◽

Bridging Capital

Even more emphasis is set on social capital in understanding, analyzing and planning poverty alleviation measures and policies. However, our understanding of the role of social capital in alleviating extreme poverty, enhancing social mobility and fighting spatial segregation, is still inadequate. Within the present study, we aim to examine and understand (1) the mechanisms that relate to social capital in the case of the segregated urban underclass and (2) the potential interventions for poverty alleviation concerning social capital. In order to examine the dynamics of poverty alleviation measures related to social capital, special attention is paid to the experiences of a cooperative network aimed at creating artificial bridging capital through the introduction of interpersonal relations locally between the middle class and underclass, the patronage network, which was initiated within a broader participatory action research (PAR) process. Our results show that bonding ties and related specific norms as tools for everyday survival easily overwrite system integration efforts for poverty alleviation and social mobility with long-term and uncertain benefits for the segregated urban underclass. In order to overcome this failure, social institutions should place more emphasis on developing meaningful interpersonal relations with the underclass since these might be able to provide personalized help, facilitation, and approximation of perspectives - all being vital for poverty alleviation and social mobility.

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Let the buyer beware: how network structure can enable (and prevent) supply chain fraud

International Journal of Operations & Production Management ◽

10.1108/ijopm-05-2021-0310 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Scott DuHadway ◽

Carlos Mena ◽

Lisa Marie Ellram

Keyword(s):

Supply Chain ◽

Network Structure ◽

Structural Characteristics ◽

Case Study Research ◽

Structural Holes ◽

Content Type ◽

New Concepts ◽

Bridge Collapse ◽

Multiple Case

PurposeSupply chain fraud is a significant global concern for firms, consumers and governments. Evidence of major fraud events suggests the role of supply chain structures in enabling and facilitating fraud, as they often involve several parties in complicated networks designed to obfuscate the fraud. This paper identifies how the structural characteristics of supply chains can play an important role in enabling, facilitating and preventing fraud.Design/methodology/approachThe research follows a theory elaboration approach. The authors build on structural holes theory in conjunction with a multiple case study research design to identify new concepts and develop propositions regarding the role of network structure on supply chain fraud.FindingsThis research shows how structural holes in a supply chain can create advantages for unscrupulous firms, a role we call tertius fraudans, or the cheating third. This situation is exacerbated by structural ignorance, which refers to the lack of knowledge about structural connections in the network. Both structural holes and structural ignorance can create information gaps that facilitate fraud, and the authors propose solutions to detect and prevent this kind of fraud.Originality/valueThis paper extends structural holes theory into the domain of fraud. Novel concepts including tertius fraudans, structural ignorance and bridge collapse are offered, alongside a series of propositions that can help understand and manage structural supply chain fraud.

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Social Network Structures for Explicit, Tacit and Potential Knowledge

Global Aspects and Cultural Perspectives on Knowledge Management ◽

10.4018/978-1-60960-555-1.ch006 ◽

2011 ◽

pp. 81-90

Author(s):

Anssi Smedlund

Keyword(s):

Knowledge Management ◽

Social Network ◽

Tacit Knowledge ◽

Network Structure ◽

Explicit Knowledge ◽

Network Structures ◽

Underlying Assumption ◽

Knowledge Assets ◽

Social Network Structure

The purpose of this conceptual article is to develop argumentation of the knowledge assets of a firm as consisting of three constructs, to extend the conventional explicit, tacit dichotomy by including potential knowledge. The article highlights the role of knowledge, which has so far not been utilized in value creation. The underlying assumption in the article is that knowledge assets can be thought of as embedded in the relationships between individuals in the firm, rather than possessed by single actors. The concept of potential knowledge is explained with selected social network and knowledge management literature. The findings suggest that the ideal social network structure for explicit knowledge is centralized, for tacit knowledge it is distributed, and for potential knowledge decentralized. Practically, the article provides a framework for understanding the connection between knowledge assets and social network structures, thus helping managers of firms in designing suitable social network structures for different types of knowledge.

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