Multi-unit Structure Research Articles

Resilience to the pandemic: The role of female management, multi-unit structure, and business model innovation

In this study, we analyse organisational resilience in the context of the recent COVID-19 pandemic. Combining arguments from the resource-based view and ergodicity, we theorise that organisational resilience depends on certain key characteristics of firms and their ability to innovate their business models. Specifically, we focus on female leadership and multi-unit structure as two characteristics that may condition the resource availability of firms during the pandemic and consider firms' innovative actions in response to the pandemic. We test our hypotheses using data from more than 11,000 firms in 34 countries. Our results confirm that female-led firms are less resilient, while multi-unit firms and those that introduced business model innovations are more resilient to the COVID-19 shock. Based on these findings, we suggest management and policy implications for building a firm’s resilience to future disruptions.

Research on a Transverse-Dislocated Magnetic-Field Modulated Brushless Contra-Rotating Machine Adopting Different Core Material Combinations

This article proposes a transverse-dislocated magnetic-field modulated brushless contra-rotating machine (TDMFM-BCRM) with multiunit structure for the contra-rotating propulsion system. Compared with the existing contra-rotating machines, it has the advantages of equal and opposite torque at any time, no brushes and no slip rings. The improved three-dimensional (3D) magnetic-field modulation principle by considering multiunit structure of the TDMFM-BCRM is investigated. Then, due to the structural complexity of the TDMFM-BCRM, there are some challenges about its manufacturing. Therefore, the performance of the TDMFM-BCRM adopting different core material combinations including electrical steel (ES) and soft magnetic composite (SMC) material is investigated. Meanwhile, a prototype is manufactured and tested to validate the theoretical analysis, finally more manufacturing methods for the TDMFM-BCRM are comparatively studied.

Assessment of Social Vulnerability in Pediatric Head and Neck Cancer Care and Prognosis in the United States

Prior investigations in social determinants of health (SDoH) in pediatric head and neck cancer (HNC) have only considered a narrow scope of HNCs, SDoH, and geography while lacking inquiry into the interrelational association of SDoH with disparities in clinical pediatric HNC. To evaluate the association of SDoH with disparities in HNC among children and adolescents and to assess which specific aspects of SDoH are most associated with disparities in dynamic and regional sociodemographic contexts. This retrospective cohort study included data about patients (aged ≤19 years) with pediatric HNC who were diagnosed from 1975 to 2017 from the Surveillance, Epidemiology, and End Results Program (SEER) database. Data were analyzed from October 2021 to October 2022. Overall social vulnerability and its subcomponent contributions from 15 SDoH variables, grouped into socioeconomic status (SES; poverty, unemployment, income level, and high school diploma status), minority and language status (ML; minoritized racial and ethnic group and proficiency with English), household composition (HH; household members aged ≥65 and ≤17 years, disability status, single-parent status), and housing and transportation (HT; multiunit structure, mobile homes, crowding, no vehicle, group quarters). These were ranked and scored across all US counties. Regression trends were performed in continuous measures of surveillance and survival period and in discrete measures of advanced staging and surgery receipt. A total of 37 043 patients (20 729 [55.9%] aged 10-19 years; 18 603 [50.2%] male patients; 22 430 [60.6%] White patients) with 30 different HNCs in SEER had significant relative decreases in the surveillance period, ranging from 23.9% for malignant melanomas (mean [SD] duration, lowest vs highest vulnerability: 170 [128] months to 129 [88] months) to 41.9% for non-Hodgkin lymphomas (mean [SD] duration, lowest vs highest vulnerability: 216 [142] months vs 127 [94] months). SES followed by ML and HT vulnerabilities were associated with these overall trends per relative-difference magnitudes (eg, SES for ependymomas and choroid plexus tumors: mean [SD] duration, lowest vs highest vulnerability: 114 [113] months vs 86 [84] months; P < .001). Differences in mean survival time were observed with increasing social vulnerability, ranging from 11.3% for ependymomas and choroid plexus tumors (mean [SD] survival, lowest vs highest vulnerability: 46 [46] months to 41 [48] months; P = .43) to 61.4% for gliomas not otherwise specified (NOS) (mean [SD] survival, lowest vs highest vulnerability: 44 [84] months to 17 [28] months; P < .001), with ML vulnerability followed by SES, HH, and HT being significantly associated with decreased survival (eg, ML for gliomas NOS: mean [SD] survival, lowest vs highest vulnerability: 42 [84] months vs 19 [35] months; P < .001). Increased odds of advanced staging with non-Hodgkin lymphoma (OR, 1.21; 95% CI, 1.02-1.45) and retinoblastomas (OR, 1.31; 95% CI, 1.14-1.50) and decreased odds of surgery receipt for melanomas (OR, 0.79; 95% CI, 0.69-0.91) and rhabdomyosarcomas (OR, 0.90; 95% CI, 0.83-0.98) were associated with increasing overall social vulnerability. In this cohort study of patients with pediatric HNC, significant decreases in receipt of care and survival time were observed with increasing SDoH vulnerability.

Resilience to the pandemic: The role of female management, multi-unit structure, and business model innovation

Resilience to the pandemic: The role of female management, multi-unit structure, and business model innovation

A novel type of chaotic attractor with a multiunit structure: from multiscroll attractors to multi-bond orbital attractors

A novel type of chaotic attractor with a multiunit structure: from multiscroll attractors to multi-bond orbital attractors

The moonlighting activities of dihydrolipoamide dehydrogenase: Biotechnological and biomedical applications.

Dihydrolipoamide dehydrogenase (DLDH) is a homodimeric flavin-dependent enzyme that catalyzes the NAD+ -dependent oxidation of dihydrolipoamide. The enzyme is part of several multi-enzyme complexes such as the Pyruvate Dehydrogenase system that transforms pyruvate into acetyl-co-A. Concomitantly with its redox activity, DLDH produces Reactive Oxygen Species (ROS), which are involved in cellular apoptotic processes. DLDH possesses several moonlighting functions. One of these is the capacity to adhere to metal-oxides surfaces. This was first exemplified by the presence of an exocellular form of the enzyme on the cell-wall surface of Rhodococcus ruber. This capability was evolutionarily conserved and identified in the human, mitochondrial, DLDH. The enzyme was modified with Arg-Gly-Asp (RGD) groups, which enabled its interaction with integrin-rich cancer cells followed by "integrin-assisted-endocytosis." This allowed harnessing the enzyme for cancer therapy. Combining the TiO2 -binding property with DLDH's ROS-production, enabled us to develop several medical applications including improving oesseointegration of TiO2 -based implants and photodynamic treatment for melanoma. The TiO2 -binding sites of both the bacterial and human DLDH's were identified on the proteins' molecules at regions that overlap with the binding site of E3-binding protein (E3BP). This protein is essential in forming the multiunit structure of PDC. Another moonlighting activity of DLDH, which is described in this Review, is its DNA-binding capacity that may affect DNA chelation and shredding leading to apoptotic processes in living cells. The typical ROS-generation by DLDH, which occurs in association with its enzymatic activity and its implications in cancer and apoptotic cell death are also discussed.

Novel Filtering Method Based on Metasurface Antenna and Its Application for Wideband High-Gain Filtering Antenna With Low Profile

A novel filtering method based on the metasurface antenna (MSA) with radiation nulls is proposed without loading extra circuits. Due to the specific multiunit structure of MSA, the filtering method is first realized on each radiating metasurface (MS) unit by introducing a multifolded U-shaped slot and a defected ground structure to generate lower edge radiation nulls. Meanwhile, coplanar parasitic patches are loaded around the MS units to provide upper edge nulls and simultaneously introduce extra in-band resonances for wide passband. Thus, a low-profile, wideband, and high-gain filtering antenna is readily constructed. To verify the concept, a prototype with a low profile of only $0.04\lambda _{{0}}$ is designed and fabricated. The simulated and measured results agree well, demonstrating a good performance with large impedance bandwidth of about 20%, high average gain of 8 dBi, and high aperture efficiency of about 90%, together with high out-of-band suppression levels of about 20 dB. In addition, the radiation patterns are symmetric in both the E- and H-planes with cross-polarization suppressions of over 20 dB. Compared with the reported filtering antennas, the proposed filtering MSA can achieve the wideband filtering response in a low profile, as well as high gain with high aperture efficiency.

Variable repeats in the eukaryotic polyubiquitin gene ubi4 modulate proteostasis and stress survival

Ubiquitin conjugation signals for selective protein degradation by the proteasome. In eukaryotes, ubiquitin is encoded both as a monomeric ubiquitin unit fused to a ribosomal gene and as multiple ubiquitin units in tandem. The polyubiquitin gene is a unique, highly conserved open reading frame composed solely of tandem repeats, yet it is still unclear why cells utilize this unusual gene structure. Using the Saccharomyces cerevisiae UBI4 gene, we show that this multi-unit structure allows cells to rapidly produce large amounts of ubiquitin needed to respond to sudden stress. The number of ubiquitin units encoded by UBI4 influences cellular survival and the rate of ubiquitin-proteasome system (UPS)-mediated proteolysis following heat stress. Interestingly, the optimal number of repeats varies under different types of stress indicating that natural variation in repeat numbers may optimize the chance for survival. Our results demonstrate how a variable polycistronic transcript provides an evolutionary alternative for gene copy number variation.

Protein Chemical Cross-linking/Mass Spectrometry: From raw data to fully immersive visualizations

Proteins are the base component that make all living organisms function. They are made up of amino acids and are responsible for the structure, function, and regulation of organisms&#x2019; tissues and organs. They can exist alone or as part of a multi-unit structure. They interact with other proteins to form stable or transient complexes. Protein function, such as transporting signals or converting energy, is determined by its structure, therefore being critical that we understand protein complexes at the cellular level. Chemical cross-linking combined with mass spectrometry is an established method in protein chemistry to explain lowresolution 3D protein structures and interacting sequences in protein complexes. Chemical cross-linking of a protein enables scientists to understand how the protein folds, whereas intermolecular cross-linking between different proteins enables to determine which components interact and how and where they physically contact each other. Mass spectrometry is used to acquire distance information and distance constraints within a molecule. The challenge is to how to best take advantage of the information provided by these methods utilizing novel visualization analytics that can help explore much more detailed information on protein structure than traditional biomechanical methods, such as the Edman degradation which sequentially removes one residue at a time and the structures are observed through chromatographic procedures. Additionally, data resulting from chemical cross-linking in most cases come in a raw format that makes it hard for the user to absorb the data and get a bigger picture of the existing interactions as well as getting a close insight on smaller reactions. This has motivated the department of Bioinformatics at the University of Arkansas at Little Rock to develop an algorithm named &#x201C;X-Linked Peptide Mapping&#x201D; that allows the analysis of the data and identify interacting peptides (short chains of amino acids) in an easier, more accurate way avoiding the limitations mentioned before. Since the field of chemical cross-linking mass spectrometry of protein-protein interactions hasn&#x2019;t been explored visually in a comprehensive way before, the results encouraged us at the Emerging Analytics Center at the University of Arkansas at Little Rock to develop an interactive web application that allows the user to visualize the results of the analysis including 2D information representations as well as 3D structural modeling representation of the interactions,. This paper presents preliminary research in this area, including the development of a prototype immersive environment to explore the molecular structures.

Organizational structure and corporate performance: insights from 6,065 listed corporations

Purpose – Due to the great distinctions for the legal environments, institutions and taxations, the restrictive external financing and costly financing cost, and great influence of macroeconomy or regulations on single industry, firms may change or adjust their organization structure to adapt to rapidly changing environment. Flat structure can decentralize the powers to subsidiary managers and can internalize the managerial market to promote competition among subsidiary managers and create an internal capital market within firms to alleviate external financing constrains, and it is matched with the diversification strategy to lower the operation risk and regulation risk for firms in changing environment. The paper aims to discuss these issues. Design/methodology/approach – The data of 6,065 listed corporations in China securities market since 2001-2006 are used to empirically test the hypotheses. Findings – The paper examines the efficiency of flat structure within the firm, investigating its influence on capital allocation and corporate performance. It shows that flat structure is better in emerging market since it is efficient in capital allocation, reducing the inefficient investment by reducing the overinvestment and alleviating the underinvestment, thus beneficial for corporate performance, both short-term and long-term accounting returns. Practical implications – From the results of this study, the paper can derive the important managerial implications that top managers should strengthen flexibility through flat structure so that their firms can grasp opportunities and obtain advantages through efficient improvement of mobility, adaptability, and combination in an uncertain environment. Moreover, flat structure can decentralize the powers to subordinate managers and create an internal managerial market and internal capital market within firms. Originality/value – By using the previous and change of multi-unit structure, the change of corporate performance, diverse and concentrated firms, the paper shows that results are not due to the endogenous problem. The study finds that in less-developed capital market under the current situation, flat structure is better, which suggests that flat structure can properly implement the strategies in emerging market and beneficial for corporate performance.

Simulation on Slinging and Reshipment System in Mine

Aiming at the problenm of transportation to underground, and slinging, reshipment, assembly in underworkings for mining lage equipment , a set of slinging and reshipment system in the underground is developed. This system is a steel-frame structure consisted of multi-unit bridged structure junction,in which the double T-iron is taken as main load-bearing beam,and U-steel unit welded by back-to-back method is as a slanted prop triangle secondary beam.This system adoptes the three-dimensional modeling software Solidworks2007, and its COSMOS/Works modules, for the three-dimensional modeling and finite element analysis to this system. Through the finite element analysis, verified the correctness of the component design.

Business Strategy, Flat Structure and Operating Efficiency: Evidence from China

Due to the great distinctions for the legal environment, institutional and taxations, the restrictive external financing and costly financing cost, and great influence of macro economy or regulation on single industry, firms may change or adjust their organization structure to adaptable to their business strategy. Flat structure can decentralize the powers to subordinate managers, and can internalize the managerial market to promote competition among subsidiary managers, and create an internal capital market within firms to alleviate external financing constrains, and it is matched with the diversification strategy to lower the operation risk and regulation risk for firms in changing environment. Using the data of listed firms in China, an emerging market, this paper examines the efficiency of flat structure within the firm, investigating its influence on capital allocation and firm performance. It shows that flat structure is better in emerging market since it is efficient in capital allocation, reducing the inefficient investment by reducing the overinvestment and alleviating the underinvestment, thus beneficial for firm performance, both short-term and long-term accounting returns. By using the previous and change of multi-unit structure, the change of performance, diverse and concentrated firms, we show that results are not due to the endogenous problem. In all, in less developed capital market under current situation, flat structure is better. It suggests that flat structure can properly implement the strategies in emerging market and beneficial for performance and efficiency.

Importance measure on finite time horizon and application to Markovian multistate production systems

The sensitivity analysis or the reliability importance analysis of complex industrial systems aims to identify, in a multiunit structure, which components contribute the most to a variation of the performance criterion. In this paper an importance measure, called the multidirectional sensitivity measure, is considered; it is defined as the derivative of the performance in the direction of one parameter in the direction of a group of parameters (failure and repair rates of components, for example), or in any direction of the transition rates of a Markovian system. It is really a directional derivative in the direction of a vector in the appropriate space. There is a homotopy on the matrices that acts on the parameter space. This contrasts with the approach through components, and is less dependent on the structure or interaction of components than classical Birnbaum importance factors. This importance measure proposed for sensitivity analysis of steady state reliability is developed herein for the transient state. It is also extended and applied to the study of the production capacity of multistate production systems such as manufacturing, production lines, and power generation, which exhibit performances that can settle on different levels depending on the operative conditions of the constitutive components. A simple numerical example is introduced to show why this measure provides an efficient tool to investigate not only the importance of a given component, but also the importance of a class of components, the importance of the maintenance and, more generally, the effect of the simultaneous change of several design parameters.

The Role of Bedding Fractures in the Hydrogeology of Sedimentary Bedrock—Evidence from the Newark Basin, New Jersey

AbstractBedding‐plane partings, particularly those enlarged by stress relief, tend to provide principal ground‐water flow pathways which are often overlooked. In order to identify them, the use of a proper conceptual model of the bedrock aquifer system and appropriate methods of hydrogeologic characterization are necessary. Several pervasive bedding partings were identified at a study site located within a dipping sequence of mudstone and shales, typical of the Passaic Formation in the Newark Basin of New Jersey. These bedding fractures constitute the discrete aquifer units of a multiunit, leaky bedrock aquifer system. One such unit of exceptional transmissivity (the “Raritan unit”) was identified and selected for a detailed characterization. Results of three short‐duration pumping tests verified the continuity and relatively uniform transmissivity of the Raritan unit over distances exceeding 1,500 feet. Significant hydrochemical differences between the various aquifer units at this 100‐acre site were found to be consistent with the multiunit structure of the bedrock aquifer system. A similar pattern can be observed in regional hydrochemical data recently published by others. The principal finding, that a few bedding fractures dominate ground‐water flow at many sites in the region, has a major implication on hydrogeologic characterization requirements for the water supply, well‐head protection, and aquifer remediation projects in the Newark Basin and similar areas of sedimentary bedrock.

A Multiunit Wire-Mobile Robot that Avoids Obstacles and Transfers to Branch Wires.

Although there is a large demand for wire-mobile robots, it is very difficult to design a mobile robot that both avoids obstacles and transfers to a branch wire. This paper describes methods of obstacle avoidance and transferral to branch wires for a wire-mobile robot with a multiunit structure. Basic analysis, synthesis, and experimental results clarify the kinematics of and control method for this mobile robot. We also demonstrate an ultrasonic sensing system for environmental recognition, which is necessary for autonomous robot motion. The multiunit structure avoids obstacles, but it uses many actuators. We therefore propose a compact wire-mobile robot with a balancer that transfers the center of gravity.

Method of both obstacle avoidance and transferal to a branch wire for a wire mobile robot with a multiunit structure.

Although there is a large demand for wire mobile robots, it is very difficult for the mobile robot to perform both obstacle avoidance and transferal to a branch wire. This paper describes methods of both obstacle avoidance and transferal to branch wires for the wire mobile robot with a multiunit structure. Basic analysis, synthesis and experimental results clarify both the kinematics and control method for the mobile robot with a multiunit structure which can perform both obstacle avoidance and transferal to a branch wire. Moreover, we demonstrate an ultrasonic sensing system for environment recognition, which is necessary for autonomous robot motion. Although the multiunit structure can realize an obstacle avoidance mechanism, its structure uses many actuators. Therefore, we proposed a compact wire mobile robot with a balancer to transfer the center of gravity.

Haemocyanin mRNA from arthropod and mollusc origin. Evidence for a multi-unit structure in mollusc haemocyanin mRNA.

mRNA from two molluscs, the snail Levantina hierosolima and the cuttlefish Sepia officinalis, and one arthropod, the scorpion Leiurus quinquestriatus, were found to contain species that hybridize with an oligodeoxynucleotide sequence corresponding to the six-amino-acid sequence His-His-Trp-His-Trp-His postulated to carry binuclear copper in arthropod haemocyanins. The duplexes formed between the oligodeoxynucleotide and mRNA from Leiurus and Levantina had similar 'melting' temperatures, namely 46.5 and 44.5 degrees C respectively. The hybridizable mRNA species were identified with mRNA that codes for haemocyanin, Hc mRNA. Electrophoresis under denaturing conditions of Leiurus Hc mRNA gave a single band corresponding to 2.3 kb (kilobases), consistent with the value of 75 000 reported for the Mr of the polypeptide chain of arthropod haemocyanin. Electrophoresis of mollusc Hc mRNA yielded RNA bands corresponding to 9.4, 6.7, 4.0 and 1.7 kb for Levantina and 9.5, 2.8 and 1.7 kb for Sepia. The 9.4 and 9.5 kb species represent authentic Hc mRNA and are consistent with an Mr of 350 000 for molluscan haemocyanin polypeptide chain. The faster-moving RNA bands are attributed to Hc mRNA cleavage by nucleases during isolation of mRNA. Analysis of the electrophoretic band pattern indicates a multi-unit structure for mollusc Hc mRNA.

Advances in the synthesis of macromolecular compounds. Review

The present state of the chemistry of polymer synthesis and the prospects for its future development are discussed. The range of monomers used in polymerization and polycondensation and the types of polymer formed are shown. Attention is drawn to the important fact that all synthesis reactions involve formation of polymers containing different units and therefore the need is emphasized to take account of the multiunit structure of polymers in discussion of the dependence of the properties of polymers on structure. The main requirements of modern industry in the nature of problems solvable by synthetic methods are outlined. Specific features of the development of polymer synthesis by addition polymerization and polycondensation metho ds, as well as means of modification of polymers, are revealed. The diversity of polymerization and polycondensation processes is discussed, as well as the modification of already prepared polymers mainly by the example of new reactions, especially those leading to production of polymers of a new type. The prospects for development of synthetic chemistry are indicated from the historical point of view, and the present increasing tendency toward more extensive synthesis of polymers with a specific combination of properties is emphasized.

Essay Reviews : CONS UL TA TION FOR INNO VA TIVE SCHOOLS; OD FOR MULTIUNIT STRUCTURE. Richard A. Schmuck, Donald Murray, Mary Ann Smith, Mitchell Schwartz, and Margaret Runkel. Eugene, Oregon: University of Oregon Press, 1975. 382 pages. Reviewed by Michael Martin, Assistant Professor of Education, University of Colorado

Essay Reviews : CONS UL TA TION FOR INNO VA TIVE SCHOOLS; OD FOR MULTIUNIT STRUCTURE. Richard A. Schmuck, Donald Murray, Mary Ann Smith, Mitchell Schwartz, and Margaret Runkel. Eugene, Oregon: University of Oregon Press, 1975. 382 pages. Reviewed by Michael Martin, Assistant Professor of Education, University of Colorado

Model for DNA Polymerase

EVIDENCE which has accumulated over the past decade from mammalian and non-mammalian sources about the enzyme(s) involved in DNA synthesis has indicated the possibility of a multiunit structure for this enzyme. Mammalian DNA polymerase DNA nucleotidyl-transferase (E.G.2.7.7.7) was first isolated from a high speed supernatant fraction of cell homogenates, instead of a nuclear fraction where DNA synthesis takes place1. Later it was shown that cytoplasmic fractions, obtained by non-aqueous techniques2 and also by the use of a homogeniza-tion medium containing Ca++ (ref. 3) to retain morphological integrity of nuclei, contained substantial amounts of this enzyme.