Hierarchical Organization Research Articles

Biodielectrics: old wine in a new bottle?

Biodielectrics is a subset of biological and/or bioinspired materials that has brought a huge transformation in the advancement of medical science, such as localized drug delivery in cancer therapeutics, health monitoring, bone and nerve repair, tissue engineering and use in other nanoelectromechanical systems (NEMS). While biodielectrics has long been used in the field of electrical insulation for over a century, polar dielectric properties of biological building blocks have not been well understood at the fundamental building block level. In this review article, we provide a brief overview of dielectric properties of biological building blocks and its hierarchical organisations to include polar dielectric properties such as piezo, pyro, and ferroelectricity. This review article also discusses recent trends, scope, and potential applications of these dielectrics in science and technology. We highlight electromechanical properties embedded in rationally designed organic assemblies, and the challenges and opportunities inherent in mapping from molecular amino acid building blocks to macroscopic analogs of biological fibers and tissues, in pursuit of sustainable materials for next-generation technologies.

A SANS investigation of silk-stabilized aqueous poly(3-hexylthiophene): phenyl-C61-butyric acid methyl ester nanoparticle dispersions

Regenerated silk fibroin (RSF) protein comprising both hydrophilic and hydrophobic chain segments offer great potential for interfacial interaction and stabilization of organic nanoparticles (NPs) in aqueous medium. In this work, aqueous dispersion of poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) NPs of 1:1 weight ratio were prepared using RSF as surfactant for the first time via the mini-emulsion method. The size, morphology, internal structure, interface and hierarchical organization of RSF-stabilized P3HT:PCBM NPs was investigated using UV–visible spectroscopy, contrast-variation small-angle neutron scattering (CV-SANS) and ultra-small-angle neutron scattering (CV-USANS). The P3HT:PCBM NPs were established to be stabilized in the matrix of RSF colloidal microparticles in water. Unlike the commonly used surfactant sodium dodecyl sulfate which produces core–shell (PCBM–P3HT) NPs, the RSF molecules generated P3HT:PCBM NPs with internal structure that resemble phase-separated solvent-cast films. The as-prepared dispersion has good film-forming ability and has been demonstrated for fabrication of composite films comprising graphene oxide.

Retraction: Two-step naked-eye detection of lectin by hierarchical organization of soft nanotubes into liquid crystal and gel phases.

Retraction of 'Two-step naked-eye detection of lectin by hierarchical organization of soft nanotubes into liquid crystal and gel phases' by Naohiro Kameta et al., Chem. Commun., 2015, 51, 6816-6819, https://doi.org/10.1039/C5CC01464F.

Systems-chart approach to the design of spin relaxation times in molecular qubits.

Molecular qubits are a promising platform for future quantum information science technologies; however, to find success in novel devices requires that the molecules exhibit long spin relaxation times. Understanding and optimizing these relaxation times has been shown to be challenging and much experimental work has been done to understand how various chemical features of the molecular qubit influence relaxation times. Here we have curated a data set of relaxation times of metal complex molecular qubits and formulated systems design charts to provide a hierarchical organization of how chemical variables affect relaxation times via known physical processes. We demonstrate the utility of the systems charts by combining examples from the literature with calculated descriptors for molecules in the dataset. This approach helps reduce the complexity associated with de novo molecular design by providing a map of interdependencies and identifying features to prioritize during synthesis.

Dendrites contribute to the gradient of intrinsic timescales encompassing cortical and subcortical brain networks.

Cytoarchitectonic studies have uncovered a correlation between higher levels of cortical hierarchy and reduced dendritic size. This hierarchical organization extends to the brain's timescales, revealing longer intrinsic timescales at higher hierarchical levels. However, estimating the contribution of single-neuron dendritic morphology to the hierarchy of timescales, which is typically characterized at a macroscopic level, remains challenging. Here we mapped the intrinsic timescales of six functional networks using functional magnetic resonance imaging (fMRI) data, and characterized the influence of neuronal dendritic size on intrinsic timescales of brain regions, utilizing a multicompartmental neuronal modeling approach based on digitally reconstructed neurons. The fMRI results revealed a hierarchy of intrinsic timescales encompassing both cortical and subcortical brain regions. The neuronal modeling indicated that neurons with larger dendritic structures exhibit shorter intrinsic timescales. Together these findings highlight the contribution of dendrites at the neuronal level to the hierarchy of intrinsic timescales at the whole-brain level. This study sheds light on the intricate relationship between neuronal structure, cytoarchitectonic maps, and the hierarchy of timescales in the brain.

Multi-Scale Spatio-Temporal Fusion with Adaptive Brain Topology Learning for fMRI Based Neural Decoding.

Neural decoding aims to extract information from neurons' activities to reveal how the brain functions. Due to the inherent spatial and temporal characteristics of brain signals, spatio-temporal computing has become a hot topic for neural decoding. However, the extant spatio-temporal decoding methods usually use static brain topology, ignoring the dynamic patterns of the interaction between brain regions. Further, they do not identify the hierarchical organization of brain topology, leading to only superficial insight into brain spatio-temporal interactions. Therefore, here we propose a novel framework, the Multi-Scale Spatio-Temporal framework with Adaptive Brain Topology Learning (MSST-ABTL), for neural decoding. It includes two new capabilities to enhance spatio-temporal decoding: i) ABTL module, which learns dynamic brain topology while updating specific patterns of brain regions, ii) MSST module, which captures the association of spatial pattern and temporal evolution, and further enhances the interpretability of the learned dynamic topology from multi-scale perspective. We evaluated the framework on the public Human Connectome Project (HCP) dataset (resting-state and task-related fMRI data). The extensive experiments show that the proposed MSST-ABTL outperforms state-of-the-art methods on four evaluation metrics, and also can renew the neuroscientific discoveries in the brain's hierarchical patterns.

Consensus Seeking in Large-Scale Multiagent Systems With Hierarchical Switching-Backbone Topology.

Recent developments in multiagent consensus problems have heightened the role of network topology when the agent number increases largely. The existing works assume that the convergence evolution typically proceeds over a peer-to-peer architecture where agents are treated equally and communicate directly with perceived one-hop neighbors, thus resulting in slower convergence speed. In this article, we first extract the backbone network topology to provide a hierarchical organization over the original multiagent system (MAS). Second, we introduce a geometric convergence method based on the constraint set (CS) under periodically extracted switching-backbone topologies. Finally, we derive a fully decentralized framework named hierarchical switching-backbone MAS (HSBMAS) that is designed to conduct agents converge to a common stable equilibrium. Provable connectivity and convergence guarantees of the framework are provided when the initial topology is connected. Extensive simulation results on different-type and varying-density topologies have shown the superiority of the proposed framework.

Settlement Restructuring for Enhanced Socio-Economic Development in Ushongo Local Government Area, Benue State, Nigeria.

The study examined settlement restructuring for enhanced socio-economic development in Ushongo L.G.A., Benue State, Nigeria. The study was focused on the relationship between settlement size and infrastructure availability; the impacts of settlement size on service availability; factors responsible for the prevailing settlement pattern in the study area; and how the settlement pattern has impacted on the development of Ushongo L.G.A. The methods adopted for the collection of data was the questionnaire, direct field observation as well as inventory taking. Results obtained from the field were presented using descriptive statistics in the form of simple percentages as well as graphs. Nearest Neighbour Analysis was also computed to determine the extent of settlement dispersal in the study area. Result obtained showed that a disperse settlement pattern prevailed in the study area. The result further revealed that settlement size has a positive significant relationship with the available services in the selected settlement in Ushongo L.G.A. A nearly perfect correlation coefficient was obtained and found to be significant at a confidence level of 0.05. Findings also revealed that 36.6% of the respondents opined that government neglect as well as the absence of communal living (34.7%) were the major reasons for the slow rate of socio-economic development in the study area. The study recommended approaches to restructuring settlements aimed at promoting both population concentration and a hierarchical organisation of functions within specific chosen areas. The study therefore, concluded that, determined that there is a substantial relationship between development and, focal living. Consequently, the study recommended that people in Ushongo L.G.A should be encouraged to settle in large concentrations so as to meet the required service threshold needed to provide infrastructure for a better day-to-day life of the people in the study area.

Detection of Cancer Stem Cells in Normal and Dysplastic/Leukemic Human Blood.

The hierarchical organization of the leukemic stem cells (LSCs) is identical to that of healthy counterpart cells. It may be split into roughly three stages: a small number of pluripotent stem cells at the top, fewlineage-restricted cells in the middle, and severalterminally differentiated blood cells at the bottom. Although LSCs can differentiate into the hematopoietic lineage, they can also accumulate as immature progenitor cells, also known as blast cells. Since blast cells are uncommon in healthy bloodstreams, their presence might be a sign of cancer. For instance, a 20% blast cutoff in peripheral blood or bone marrow is formally used to distinguish acute myeloid leukemia from myelodysplastic neoplasms, whichis essential to plan the patients' management. Many techniques may be useful for blast enumeration: one of them is flow cytometry, which can perform analyses on many cells by detecting the expression of cell surface markers. Leukemic and non-leukemic blast cells might indeed be characterized by the same surface markers, but these markers are usually differently expressed. Here we propose to use CD45, in combination with CD34 andother cell surface markers, to identify and immunophenotype blast cells in patient-derived samples.

국가교육위원회의 거버넌스적 재조명과 국민참여 활성화 방안 탐색

This study explores strategies for the National Education Commission to function as a cooperative educational governance for expanded citizen participation. The governance model is divided into structural (involving a National Participation Committee at the central level and a regional educational governance at the local level) and process-oriented (involving a Public Deliberation Committee and a social consultation model). Analyzing the models, the study focuses on the degree of hierarchical organization and organizational organization of understanding groups. The National Participation Committee exhibits cooperative governance with low organizational organization of understanding groups, requiring consideration of advisory body limitations and ways to incorporate field voices. Regional educational governance shows a hierarchical form, necessitating attention to network configuration to avoid operation by compromise rather than stakeholder participation. Both the Public Deliberation Committee and the social consultation model have cooperative governance, but differences in organizational organization and hierarchical structure suggest the need for specialized mechanisms based on issue characteristics. Overall, the study suggests improvements for each model to optimize citizen participation and cooperation in educational governance.

Functional Connectome Hierarchy in Schizotypy and Its Associations With Expression of Schizophrenia-Related Genes.

Schizotypy has been conceptualized as a continuum of symptoms with marked genetic, neurobiological, and sensory-cognitive overlaps to schizophrenia. Hierarchical organization represents a general organizing principle for both the cortical connectome supporting sensation-to-cognition continuum and gene expression variability across the cortex. However, a mapping of connectome hierarchy to schizotypy remains to be established. Importantly, the underlying changes of the cortical connectome hierarchy that mechanistically link gene expressions to schizotypy are unclear. The present study applied novel connectome gradient on resting-state fMRI data from 1013 healthy young adults to investigate schizotypy-associated sensorimotor-to-transmodal connectome hierarchy and assessed its similarity with the connectome hierarchy of schizophrenia. Furthermore, normative and differential postmortem gene expression data were utilized to examine transcriptional profiles linked to schizotypy-associated connectome hierarchy. We found that schizotypy was associated with a compressed functional connectome hierarchy. Moreover, the pattern of schizotypy-related hierarchy exhibited a positive correlation with the connectome hierarchy observed in schizophrenia. This pattern was closely colocated with the expression of schizophrenia-related genes, with the correlated genes being enriched in transsynaptic, receptor signaling and calcium ion binding. The compressed connectome hierarchy suggests diminished functional system differentiation, providing a novel and holistic system-level basis for various sensory-cognition deficits in schizotypy. Importantly, its linkage with schizophrenia-altered hierarchy and schizophrenia-related gene expression yields new insights into the neurobiological continuum of psychosis. It also provides mechanistic insight into how gene variation may drive alterations in functional hierarchy, mediating biological vulnerability of schizotypy to schizophrenia.

BEHAVIORAL METHODS EMPLOYED TO INVESTIGATE THE STRUCTURE OF AUTOBIOGRAPHICAL MEMORIES

Memory research conducted in laboratories require controlled experiments in order to eliminate the confounding factors that can affect memory retrieval. However autobiographical memories require the retrieval of distant memories which are most of the time not verifiable. Due to the differences related to Autobiographical memory these controlled experiments cannot be used and different methods are required. Cue word technique, diary studies, recording event by using devices, Autobiographical Memory Interview and Autobiographical Interview are some of the behavioral methods employed for Autobiographical memory research. These methods have both some advantages and some disadvantages, which should be considered before they are used. The findings from the studies employing these methods indicated that Autobiographical memory has a hierarchical organization, it consists of a sementic component and an episodic component, and some of the cues are ineffective for the retrieval of autobiographical memories. Most of these methods can also be employed in research investigating the impaired components of autobiographical memory for patients with memory disorders like Alzheimer’s disease. In this review the bahavioral methods empleyed to investigate the structure of Autobiographical memories will be explored. First the differences of autobiographical memory from memory investigated in laboratory and the need for different methods in autobiographical memory research will be mentioned. Then behavioral methods to investigate the structure of Autobiographical memory, how they are used and the findings obtained from these studies seperately and in common will be discussed.

Evolution of hierarchy and irreversibility in theoretical cell differentiation model.

The process of cell differentiation in multicellular organisms is characterized by hierarchy and irreversibility in many cases. However, the conditions and selection pressures that give rise to these characteristics remain poorly understood. By using a mathematical model, here we show that the network of differentiation potency (differentiation diagram) becomes necessarily hierarchical and irreversible by increasing the number of terminally differentiated states under certain conditions. The mechanisms generating these characteristics are clarified using geometry in the cell state space. The results demonstrate that the hierarchical organization and irreversibility can manifest independently of direct selection pressures associated with these characteristics, instead they appear to evolve as byproducts of selective forces favoring a diversity of differentiated cell types. The study also provides a new perspective on the structure of gene regulatory networks that produce hierarchical and irreversible differentiation diagrams. These results indicate some constraints on cell differentiation, which are expected to provide a starting point for theoretical discussion of the implicit limits and directions of evolution in multicellular organisms.

SiLiBA: Building the geological chert lithotheque

Lithotheques collect and exhibit raw material used by human communities for the manufacturing of objects during the Prehistory and represents an important tool of their knowledge. These collections are essential in the procuring and provenance study of archaeological lithic industries. 
 This paper aims, firstly, to introduce SiLiBA, the lithotheque of the Earth and Geoenvironmental Sciences Department of the University of Bari Aldo Moro (Italy), as reference collection in the archaeological field studies, and secondly to propose guidelines and rules to build a lithotheque. The collection consists of about 900 pieces of geological cherts, which are the result of an expanded collecting action of primary and secondary cherts across Italy (Apulia, Basilicata, Sicily), Croatia, and Switzerland, belonging to formations from the Cretaceous to the Quaternary Period. All the chert samples were described according to the non-destructive multiparametric protocol for chert investigation (NM-PCI), providing a modular dataset of binary, ordinal and continuous variables which integrates petrographycal, micropaleontological, chemical and physical data. Such results were summarized in suitable reports, with also geographic coordinates, geological description and photographic documentation, in a digital database, which will be soon online. Cherts are grouped in 37 suitable boxes, following geographic hierarchical organisation and reporting informative labels. Some representative samples are exposed in the Earth Sciences Museum of the same University. Furthermore, the lithotheque is equipped by a dedicated laboratory which includes optical microscopes, a glossmeter and a spectrophotocolorimeter. The promotion in the last years was guaranteed by dissemination activities for educational and academic communities, including an interactive laboratory of experimental archaeology.

Harnessing Macromolecular Chemistry to Design Hydrogel Micro- and Macro-Environments.

Cell encapsulation within three-dimensional hydrogels is a promising approach to mimic tissues. However, true biomimicry of the intricate microenvironment, biophysical and biochemical gradients, and the macroscale hierarchical spatial organizations of native tissues is an unmet challenge within tissue engineering. This review provides an overview of the macromolecular chemistries that have been applied toward the design of cell-friendly hydrogels, as well as their application toward controlling biophysical and biochemical bulk and gradient properties of the microenvironment. Furthermore, biofabrication technologies provide the opportunity to simultaneously replicate macroscale features of native tissues. Biofabrication strategies are reviewed in detail with a particular focus on the compatibility of these strategies with the current macromolecular toolkit described for hydrogel design and the challenges associated with their clinical translation. This review identifies that the convergence of the ever-expanding macromolecular toolkit and technological advancements within the field of biofabrication, along with an improved biological understanding, represents a promising strategy toward the successful tissue regeneration.

It is Challenging to Shift the Norm: Exploring how to Anticipate and Address Microaggressions in Clinical Learning Environments.

Increased attention to improving a culture of belonging in clinical learning environments has led to various approaches to addressing microaggressions. However, most approaches in the literature focus on responding or reacting to microaggressions with insufficient attention to building trust before microaggressions might occur. Research on microaggressions in clinical learning environments suggests anticipatory or pre-emptive conversations about microaggressions may foster greater trust. In this study, the authors explored how diverse participants perceived the experience of anticipatory conversations about potential microaggressions. Overall, the authors sought to gain a deeper understanding of how pre-emptive and anticipatory conversations may influence an organization's approach to addressing microaggressions in clinical learning environments. The authors utilized constructivist grounded theory methodology and conducted individual qualitative interviews with 21 participants in an academic department within a larger health sciences center in the United States. Findings suggest that anticipatory conversations about microaggressions were challenging due to existing norms in dynamic clinical learning and working environments. Participants shared that the idea of anticipating microaggressions elicited dissonance. Conversations about microaggressions could potentially be facilitated through leaders who role model vulnerability, organizational supports, and an individualized approach for each team member and their role within a complex hierarchical organization. Anticipating and addressing microaggressions in clinical learning environments holds tremendous potential, however, any conversations about personal identity remain challenging in medical and healthcare environments. This study suggests that any attempts to address microaggressions requires attention to cultural norms within healthcare environments and the ways that hierarchical organizations can constrain individual agency.

Skeletal Muscle Spheroids as Building Blocks for Engineered Muscle Tissue.

Spheroids exhibit enhanced cell-cell interactions that facilitate improved survival and mimic the physiological cellular environment in vivo. Cell spheroids have been successfully used as building blocks for engineered tissues, yet the viability of this approach with skeletal muscle spheroids is poorly understood, particularly when incorporated into three-dimensional (3D) constructs. Bioprinting is a promising strategy to recapitulate the hierarchical organization of native tissue that is fundamental to its function. However, the influence of bioprinting on skeletal muscle cell spheroids and their function are yet to be interrogated. Using C2C12 mouse myoblasts and primary bovine muscle stem cells (MuSCs), we characterized spheroid formation as a function of duration and cell seeding density. We then investigated the potential of skeletal muscle spheroids entrapped in alginate bioink as tissue building blocks for bioprinting myogenic tissue. Both C2C12 and primary bovine MuSCs formed spheroids of similar sizes and remained viable after bioprinting. Spheroids of both cell types fused into larger tissue clusters over time within alginate and exhibited tissue formation comparable to monodisperse cells. Compared to monodisperse cells in alginate gels, C2C12 spheroids exhibited greater MyHC expression after 2 weeks, while cells within bovine MuSC spheroids displayed increased cell spreading. Both monodisperse and MuSC spheroids exhibited increased expression of genes denoting mid- and late-stage myogenic differentiation. Together, these data suggest that skeletal muscle spheroids have the potential for generating myogenic tissue via 3D bioprinting and reveal areas of research that could enhance myogenesis and myogenic differentiation in future studies.

Rethinking identity with second-generation Italian female writers

This article explores the impact of second-generation Italian female writers in the post-structuralist and post-colonial debate, analysing 'India' and Ruben by Gabriella Kuruvilla and 'Sausages' by Somali-Italian author Igiaba Scego. It will be argued that these three texts deconstruct the essentialist idea of identity as the expression of an individual's or community's inner core traditionally promoted by Western societies to justify hierarchical and oppressive social organisations, configuring themselves as a tool to rethink identity. 'India', 'Ruben', and 'Sausages' reveal the social nature of identity, showing that what we are results from complex social processes.

Suppliers’ entry, upgrading, and innovation in mining GVCs: lessons from Argentina, Brazil, and Peru

Abstract This paper studies whether the mining sector can represent a true engine of growth for selected Latin American countries through the suppliers’ entry and upgrading within mining value chains. We start by using international trade data to study where mining value is added and how rents are distributed across countries. Despite their importance in the production and exports of copper ores and concentrate, the participation of the selected Latin American countries in copper value chains is still confined to the upstream segment. Moreover, their share of innovation relevant for the sector remains very limited, although new data on patenting and publications show that the sector is becoming increasingly innovative worldwide. Then, we use new microeconomic evidence from case-studies in Latin America to explore the specific opportunities and obstacles faced by mining suppliers in entering the value chain and upgrading within it, and how the regulatory and innovation systems have influenced this process. We show that barriers related to the contractual practices, lead firms’ attitudes, and the hierarchical industrial organization of the sector, coupled with the countries’ weaknesses in local innovation and regulatory systems, have been contributing to hamper suppliers’ entry into mining value chains and upgrading.

Micro- and nanostructure specific X-ray tomography reveals less matrix formation and altered collagen organization following reduced loading during Achilles tendon healing

Recovery of the collagen structure following Achilles tendon rupture is poor, resulting in a high risk for re-ruptures. The loading environment during healing affects the mechanical properties of the tendon, but the relation between loading regime and healing outcome remains unclear. This is partially due to our limited understanding regarding the effects of loading on the micro- and nanostructure of the healing tissue. We addressed this through a combination of synchrotron phase-contrast X-ray microtomography and small-angle X-ray scattering tensor tomography (SASTT) to visualize the 3D organization of microscale fibers and nanoscale fibrils, respectively. The effect of in vivo loading on these structures was characterized in early healing of rat Achilles tendons by comparing full activity with immobilization. Unloading resulted in structural changes that can explain the reported impaired mechanical performance. In particular, unloading led to slower tissue regeneration and maturation, with less and more disorganized collagen, as well as an increased presence of adipose tissue. This study provides the first application of SASTT on soft musculoskeletal tissues and clearly demonstrates its potential to investigate a variety of other collagenous tissues. Statement of significanceCurrently our understanding of the mechanobiological effects on the recovery of the structural hierarchical organization of injured Achilles tendons is limited. We provide insight into how loading affects the healing process by using a cutting-edge approach to for the first time characterize the 3D micro- and nanostructure of the regenerating collagen. We uncovered that, during early healing, unloading results in a delayed and more disorganized regeneration of both fibers (microscale) and fibrils (nanoscale), as well as increased presence of adipose tissue. The results set the ground for the development of further specialized protocols for tendon recovery.