Linkage Structures Research Articles

ROD MODELING OF STRUCTURES LEVERING MECHANISMS WITH DISTRIBUTED INERTIA

To reduce inertia of moving links into resultant force and moment vectors and to represent center of mass as node in finite element models are widely-used in mechanical calculations of linkage mechanisms. Considering distributed inertia of motion makes possible to create more precise finite element models in spatial linkage structures. By algebraically summing all the distributed inertial loads acting in both directions, perpendicular and along the axis of a constant cross section link, we can show that their intensity varies linearly along the length of link. Using this approach together with Chasles theorem for a point of free rigid body in projections onto the moving axes in the finite element method for rectilinear homogeneous rod, we reach to a more precise finite element model considering analytically distributed inertia of motion. Besides, we obtained subvectors in matrix relation which binds the generalized reaction forces acting at the contact points of the rod element with nodal generalized elastic movements. These subvectors includes the weight and inertia of a distributed spatial movement of link.

Kinematics and control approach for deployable and reconfigurable rigid bar linkage structures

Deployable building structures able to respond to varying environmental and functional conditions through shape transformations aim at an interactive and optimized behaviour towards sustainability of our built environment. A kinematics approach applied to a lightweight linkage structure is presented that builds upon aspects of flexibility and controllability through modularity and simple actuation requirements. The principal planar structure consists of serially connected rigid members. One side of the linkage is pinned to the ground and the other side is pinned to a sliding block. A single linear motion actuator detached from the structural body, acts on the sliding block, while all intermediate joints are equipped with brakes. The reconfiguration approach involves the stepwise selective locking of joints, to define a generic one degree-of-freedom (1-DOF) ‘effective crank–slider’ (ECS) mechanism. The approach is examined through simulation studies followed by hardware implementation on a small scale 1:10 prototype.

A quantitative N-glycoproteomics study of cell-surface N-glycoprotein markers of MCF-7/ADR cancer stem cells.

Isotopic-labeling quantitative N-glycoproteomics characterization of cell-surface differentially expressed N-glycosylation in MCF-7/ADR cancer stem cells (CSCs) relative to MCF-7/ADR cells was carried out at the intact N-glycopeptide level with trypsin digestion, ZIC-HILIC enrichment, isotopic diethyl labeling, RPLC-MS/MS analysis of the 1:1 mixture, and GPSeeker DB search. With a spectrum-level false discovery rate of ≤ 1%, 1,336 intact N-glycopeptides from the combination of 301 unique peptide backbones and 169 putative N-glycan linkages (52 monosaccharide compositions) were identified; the corresponding intact N-glycoproteins and N-glycosites were 289 and 305, respectively, among which 176 N-glycosites were confirmed with GlcNAc-containing site-determining b/y fragment ion pairs. The N-glycan moieties in 546 intact N-glycopeptide IDs were identified with more than one structure-diagnostic fragment ions where multiple linkage structures exist for each of the monosaccharide compositions. With the criteria of ≥ 1.5-fold change and p value < 0.05, 72 cell-surface differentially expressed intact N-glycopeptides (DEGPs) were found in MCF-7/ADR CSCs relative to MCF-7/ADR cells, where 8 and 64 were downregulated and upregulated, respectively. Graphical abstract.

Keratan Sulphate in the Tumour Environment.

Keratan sulphate (KS) is a bioactive glycosaminoglycan (GAG) of some complexity composed of the repeat disaccharide D-galactose β1→4 glycosidically linked to N-acetyl glucosamine. During the biosynthesis of KS, a family of glycosyltransferase and sulphotransferase enzymes act sequentially and in a coordinated fashion to add D-galactose (D-Gal) then N-acetyl glucosamine (GlcNAc) to a GlcNAc acceptor residue at the reducing terminus of a nascent KS chain to effect chain elongation. D-Gal and GlcNAc can both undergo sulphation at C6 but this occurs more frequently on GlcNAc than D-Gal. Sulphation along the developing KS chain is not uniform and contains regions of variable length where no sulphation occurs, regions which are monosulphated mainly on GlcNAc and further regions of high sulphation where both of the repeat disaccharides are sulphated. Each of these respective regions in the KS chain can be of variable length leading to KS complexity in terms of chain length and charge localization along the KS chain. Like other GAGs, it is these variably sulphated regions in KS which define its interactive properties with ligands such as growth factors, morphogens and cytokines and which determine the functional properties of tissues containing KS. Further adding to KS complexity is the identification of three different linkage structures in KS to asparagine (N-linked) or to threonine or serine residues (O-linked) in proteoglycan core proteins which has allowed the categorization of KS into three types, namely KS-I (corneal KS, N-linked), KS-II (skeletal KS, O-linked) or KS-III (brain KS, O-linked). KS-I to -III are also subject to variable addition of L-fucose and sialic acid groups. Furthermore, the GlcNAc residues of some members of the mucin-like glycoprotein family can also act as acceptor molecules for the addition of D-Gal and GlcNAc residues which can also be sulphated leading to small low sulphation glycoforms of KS. These differ from the more heavily sulphated KS chains found on proteoglycans. Like other GAGs, KS has evolved molecular recognition and information transfer properties over hundreds of millions of years of vertebrate and invertebrate evolution which equips them with cell mediatory properties in normal cellular processes and in aberrant pathological situations such as in tumourogenesis. Two KS-proteoglycans in particular, podocalyxin and lumican, are cell membrane, intracellular or stromal tissue-associated components with roles in the promotion or regulation of tumour development, mucin-like KS glycoproteins may also contribute to tumourogenesis. A greater understanding of the biology of KS may allow better methodology to be developed to more effectively combat tumourogenic processes.

Site- and structure-specific quantitative N-glycoproteomics study of differential N-glycosylation in MCF-7 cancer cells

Glycosylation is a common protein PTM, and its aberrant regulation has been widely linked to various pathological conditions including cancers. Our recent development of intact N-glycopeptide search engine GPSeeker has enabled relatively quantitative structure-specific characterization of differentially expressed intact N-glycopeptides (DEGPs) with isotopic labeling of the peptide backbones and structure-specific fragment ions of the N-glycan moieties. Here we report our site- and structure-specific relatively quantitative N-glycoproteomics study of breast MCF-7 cancer cells (relative to epithelial MCF-10A cells) using RPLC-nanoESI-MS/MS and GPSeeker. With spectrum-level FDR ≤ 1%, 581 intact N-glycopeptides with comprehensive structural information of both the peptide backbones (amino acid sequences, N-glycosites) and the N-glycan moieties (monosaccharide composition, sequence and linkages) were identified from five technical replicates (TR1, TR2, TR3, TR4 and TR5). With the criteria of quantified at least thrice out of the five technical replicates with no <1.5-fold change, p ≤ .05 and RSD ≤ 20%, 56 DEGPs were quantified from 23 N-glycosites on 19 intact N-glycoproteins. For the 19 intact N-glycoproteins observed with differential N-glycosylation expression, 14 (each with one or more DEGPs) were observed with uniform down regulation; 6 (each with one or more DEGPs) were observed with uniform up regulation; whereas one was observed with both up and down regulation. SignificanceDifferential N-glycosylation in breast MCF-7 cancer cells (relative to MCF-10A epithelial cells) were qualitatively and quantitatively characterized with site- and structure-specific N-glycoproteomics using RPLC-nanoESI-MS/MS (HCD with stepped NCEs) and intact N-glycopeptide search engine GPSeeker. With spectrum-level FDR ≤ 1%, 581 intact N-glycopeptides with comprehensive structural information of both the peptide backbones and the N-glycan moieties were identified; For the 248 putative N-glycosites, 248 were confirmed where 125 have not been annotated in UniProt as of July 25, 2019. For the 114 N-glycan putative linkage structures, 44 were confirmed with no less than one structure-diagnostic fragment ions. With the criteria of quantified at least thrice out of the five technical replicates with no < 1.5-fold change and p ≤ .05, 56 DEGPs were quantified from 21 intact N-glycoproteins; 13 and 5 intact N-glycoproteins (each with one or more DEGPs) were observed with uniform down and up regulation; whereas one were observed with simultaneous up and down regulation.

Avaliação das motivações conscientes e inconscientes associadas à escolha do parceiro conjugal: criação do instrumento baverc assente na psicanálise vincular

The selection of the marital partner compromises the individual that choses as also the individual that is assumed and identified. Clarifying what unites the couple it is also possible to clarify what disunites it. It is intended to think the individual in the marital dyad, where the individual exists as a relational and thinking being enrolled in the linkage configurations that operate consciously and unconsciously for the selection of the marital partner. The expression of the marital linkage happens simultaneously through conscious aspects such as relationships interacting among each other where the presence of the other is fundamental, weather through unconscious aspects like alliances, agreements, pacts and interphantasmatic unconscious plots and the underlying unconscious and generational familial and social linkage structures. In the assembling of the psychic spaces of the marital linkage we find intra-subjective, intersubjective and transubjective psychic spaces. An instrument was created which assesses the several relational spheres of conjugality (BAVERC) with the goal of creating a dichotomous scale about the conscious/unconscious determination of the selection of the marital object as also as to create a categorization of the conscious and unconscious aspects prevailing in each couple. This instrument is based in the perspective of linkage psychoanalysis which requires the analysis of the interfaces relative to the generation of the marital linkage.

GPSeeker Enables Quantitative Structural N-Glycoproteomics for Site- and Structure-Specific Characterization of Differentially Expressed N-Glycosylation in Hepatocellular Carcinoma.

N-Glycosylation, being one of the most common and complex protein post-translational modifications (PTMs), is known to have microheterogeneity with the presence of different N-glycan structures at a single specific glycosite. These different structures may have exactly the same monosaccharide composition but totally different differential expressions and pathological relevance. Mass spectrometry-based N-glycoproteomics has so far been successful in large-scale characterization of these N-glycans at the composition level, and structure-level identification and quantitation is urgently needed. Here we report our development of the intact N-glycopeptide search engine GPSeeker and the GPSeeker-centered quantitative structural N-glycoproteomics pipeline. In benchmark characterization of differentially expressed N-glycosylation in hepatocellular carcinoma HepG2 cells relative to LO2 cells, 5 405 and 1 081 intact N-glycopeptides with putative linkage structures were identified and quantified with isotopic dimethyl labeling and 2D liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Among the5 405 IDs, 837 were identified with no less than onestructure diagnostic fragment ion for the N-glycan moieties. Besides double isomers of sialic acid linkages and fucose sequences, quadruple isomers from combination of two linages and two sequences were chromatographically separated and confidently identified; microheterogeneity with different differentially expressions were observed on 183 out of the 231 quantifiedN-glycosites. This GPSeeker-centered quantitative structural N-glycoproteomics pipeline can be widely applied to precise qualitative and quantitative characterization of N-glycosylation with physiological and pathological relevance.

Control of nanostructures and fracture toughness of epoxy/acrylic block copolymer blends using in situ manipulation of the epoxy matrix reaction type

The effect of small amounts of curing catalysts on the nanostructures and mechanical properties of epoxy/acrylic block copolymer blends were investigated. Poly(methyl methacrylate)-b-poly(n-butyl acrylate)-b-poly (methyl methacrylate) (PMMA-b-PnBA-b-PMMA) triblock copolymer (acrylic BCP) was blended with diglycidyl ether of bisphenol-A epoxy thermosets. The blends were cured using phenol novolac (PN) with curing catalysts at less than 1 wt%. Three different curing catalysts, triphenylphosphine (TPP), 2,4,6-tris(dimethyl amino methyl)phenol (DMP), and 1,2-dimethylimidazole (DMIz), were compared. A polyol-type linkage structure was formed in the cured epoxy matrix using TPP, whereas both polyether-type linkage structure and polyol-type linkage structure were formed when DMP and DMIz were used. As a result, different nanostructures were formed in response to the different linkage structures in the epoxy matrix originated from the same blend composition of epoxy/acrylic BCP/PN. The TPP catalyst gave a spherical nanostructure, while the DMP and DMIz catalysts gave branched cylindrical nanostructures in the epoxy/acrylic BCP/PN blends. The compatibility of the PMMA-block chains of the acrylic BCPs to the cured epoxy matrix was a key factor that determined the nanostructures. The fracture toughness of the cured blends was dependent on both the nanostructures in the blends and the ductility (extent of cross-linking density) of the epoxy matrix.

A novel hydrophobic coating film of water-borne fluoro-silicon polyacrylate polyurethane with properties governed by surface self-segregation

The growing need of high-level anti-fouling coatings and the increasingly stringent environment regulations are demanding more versatile and eco-friendly hydrophobic materials to be developed in a facile manner. The current study considers a new water-borne fluoro-silicon polyacrylate polyurethane prepared in a two-step process as a viable candidate of green anti-fouling coating. Firstly, the water-borne fluoro-silicon polyacrylate (WFSiPA) dispersion was prepared via emulsion co-polymerization based on vinyl-terminated silicon compound and acrylate monomers containing hydroxyl, carboxyl, and fluorinated functional groups. Formulation was optimized based on studies of reaction process, emulsion stability and rheology, to achieve dispersion with a well-defined resin composition and a good leveling behavior for coating film cast. Then a water-borne isocyanate was introduced to cure the WFSiPA dispersion during the film cast whereby the two-component hydrophobic fluoro-silicon polyacrylate polyurethane (WFSiPAU) coating was produced. The surface self-segregation characteristic of fluorine (F)-segments and silicon (Si)-segments has been elucidated based on XPS and SEM-EDX analysis of the WFSiPA and WFSiPAU films, with strong F and Si enrichments on film surface and element gradient distributions across film cross-section clearly observed. The long Si-O-Si linkage structures of the segregated Si-segments induced a silicon dominance on film surface with fluorine dominated in an underneath buried layer. However, the curing reaction greatly enhanced the exposure of fluorine to the air as the siloxanne-based acrylate backbones was tightly cross-linked in the film, showing reduced surface self-segregations of the Si-segments. Moreover, the surface dominance of the F- and Si-segments and the curing governed the properties of the film, exhibiting an excellent surface hydrophobicity with an amphiphobicity potential, an enhanced thermal stability and tunable mechanical performances. Such novel coating films foresee promising applications in broad fields where hydrophobicity, antifouling and high performance are required.

Development of a Hand Exoskeleton System for Quantitative Analysis of Hand Functions

This paper proposes a hand exoskeleton system for evaluating hand functions. To evaluate hand functions, the hand exoskeleton system must be able to pull each finger joint, measure the finger joint angle and exerted force on the finger simultaneously. The proposed device uses serially connected 4-bar linkage structures, which have two embedded actuators with encoders and two loadcells per finger, to move each phalanx independently and measure the finger joint angles. A modular design was used for the exoskeleton, to facilitate the removal of unnecessary modules in different experiments and improve convenience. Silicon was used on the surface of the worn part to reduce the skin irritation that results from prolonged usage. This part was also designed to be compatible with various finger thicknesses. Using the proposed hand exoskeleton system, finger independence, multi-finger synergy, and finger joint stiffness were determined in five healthy subjects. The finger movement and force data collected in the experiments were used for analyzing three hand functions based on the physical and physiological phenomena.

Role of linkage structures in supply chain for managing greenhouse gas emissions

This study describes a structural decomposition analysis (SDA) of Japanese greenhouse gas (GHG) emissions from 1990 to 2005, focusing on four linkage structures in the Leontief inverse representing supply chains in Japan. The developed RAS-invariant decomposition was applied to Japanese linked input–output tables for the three 5-year periods studied. It examined the effect of the Leontief inverse on emissions changes into the specific effects of forward linkage, backward linkage, the average of forward/backward linkage and kernel structure. Our SDA method solves the problem of parameter independence completely. The accuracy of those effects has been improved mathematically compared with conventional methods. For example, it was detected that backward linkage contributes to an increase in GHG emissions, while conventional methods erroneously determine a decrease. The results of the SDA confirmed that forward linkage and kernel structure contributed to a rise in GHG emissions, and that backward linkage consistently increased emissions in the three periods. Some sectors have robust linkage in the supply chain with consistently increasing emissions, which should be preferentially improved to mitigate their indirect GHG emissions in Japan.

Dynamic Volatility Linkages between Developed and Emerging Stock Markets: A MMV-GARCH Approach

This paper investigates the short-run and long-run volatility linkage structures among developed and emerging stock markets using a multivariate multiplicative volatility GARCH (MMV-GARCH) model, which fulfills the assumption of a constant unconditional covariance matrix. The empirical results show that in the long-run volatility linkages, both developed and emerging markets are affected by the subprime mortgage crisis, but the developed stock markets are more sensitive to global financial perturbations. Moreover, the concern that the volatility linkages in stock markets are more significant after the subprime mortgage crisis is unfounded. In the short-run volatility linkages, the developed stock markets present stronger volatility correlation than the emerging markets.

Type synthesis and analysis of geared linkages with linear actuation

In the paper the type synthesis of the geared linkages with linear actuation is presented. For the planetary geared linkages the mathematical model is developed and systematically presented. The obtained relationships are used for the kinematic analysis in order to investigate the behavior of cycloid geared linkages. The analysis shows the influence of the normalized geometrical parameters on the behaviour of these geared linkage structures. DOI: http://dx.doi.org/10.5755/j01.mech.24.1.17534

University-Industry Linkages in the Disaster Resilience Sector: A Case Study of Thailand

Abstract University-industry linkages in the Disaster Resilience Sector in Thailand were studied at two main levels: the national level and the institutional level. Comparisons were made of specific data such as the linkage structures, lessons learnt, policies and barriers, between Thailand and developed countries such as the United Kingdom. This analysis was done to identify the key elements, factors and contexts in constructing and maintaining university-industry linkages in various spectrums and approaches, and to apply these to the Disaster Resilience Sector. These results can be further developed as guidelines for universities in developing countries that wish to develop university-industry linkages. The study also addressed a specific university-industry linkage called ‘secondment plan’ which includes university policies on the detachment of university staff from their regular work or position in the university for temporary assignment in industry sectors. For this part, the Talent Mobility Project, a governmental project that supports Thai university staff, particularly academic staff, in doing cooperative work with the industry sector, was analysed. This project is the responsibility of the National Science Technology and Innovation Policy Office (STI) of Thailand. The weakness and the strengths of this project were identified through interviews with senior staff of STI, Science Park and Naresuan University. The results have been developed into a guidelines model for universities in developing countries.

Investigating the Evolution of Linkage Dynamics among Equity Markets Using Network Models and Measures: The Case of Asian Equity Market Integration

The state of cross-market linkage structures and its stability over varying time-periods play a key role in the performance of international diversified portfolios. There has been an increasing interest of global investors in emerging capital markets in the Asian region. In this setting, an investigation into the temporal dynamics of cross-market linkage structures becomes significant for the selection and optimal allocation of securities in an internationally-diversified portfolio. In the quest for this, in the current study, weighted network models along with network metrics are employed to decipher the underlying cross-market linkage structures among Asian markets. The study analyses the daily return data of fourteen major Asian indices for a period of 14 years (2002–2016). The topological properties of the network are computed using centrality measures and measures of influence strength and are investigated over temporal scales. In particular, the overall influence strengths and India-specific influence strengths are computed and examined over a temporal scale. Threshold filtering is also performed to characterize the dynamics related to the linkage structure of these networks. The impacts of the 2008 financial crisis on the linkage structural patterns of these equity networks are also investigated. The key findings of this study include: a set of central and peripheral indices, the evolution of the linkage structures over the 2002–2016 period and the linkage dynamics during times of market stress. Mainly, the set of indices possessing influence over the Asian region in general and the Indian market in particular is also identified. The findings of this study can be utilized in effective systemic risk management and for the selection of an optimally-diversified portfolio, resilient to system-level shocks.

Reconstructing Late Holocene North Atlantic atmospheric circulation changes using functional paleoclimate networks

Abstract. Obtaining reliable reconstructions of long-term atmospheric circulation changes in the North Atlantic region presents a persistent challenge to contemporary paleoclimate research, which has been addressed by a multitude of recent studies. In order to contribute a novel methodological aspect to this active field, we apply here evolving functional network analysis, a recently developed tool for studying temporal changes of the spatial co-variability structure of the Earth's climate system, to a set of Late Holocene paleoclimate proxy records covering the last two millennia. The emerging patterns obtained by our analysis are related to long-term changes in the dominant mode of atmospheric circulation in the region, the North Atlantic Oscillation (NAO). By comparing the time-dependent inter-regional linkage structures of the obtained functional paleoclimate network representations to a recent multi-centennial NAO reconstruction, we identify co-variability between southern Greenland, Svalbard, and Fennoscandia as being indicative of a positive NAO phase, while connections from Greenland and Fennoscandia to central Europe are more pronounced during negative NAO phases. By drawing upon this correspondence, we use some key parameters of the evolving network structure to obtain a qualitative reconstruction of the NAO long-term variability over the entire Common Era (last 2000 years) using a linear regression model trained upon the existing shorter reconstruction.

DISC: DISulfide linkage Characterization from tandem mass spectra.

Enzymatic digestion under appropriate reducing conditions followed by mass spectrometry analysis has emerged as the primary method for disulfide bond analysis. The large amount of mass spectral data collected in the mass spectrometry experiment requires effective computational approaches to automate the interpretation process. Although different approaches have been developed for such purpose, they always choose to ignore the frequently observed internal ion fragments and they lack a reasonable quality control strategy and calibrated scoring scheme for the statistical validation and ranking of the reported results. In this research, we present a new computational approach, DISC (DISulfide bond Characterization), for matching an input MS/MS spectrum against the putative disulfide linkage structures hypothetically constructed from the protein database. More specifically, we consider different ion types including a variety of internal ions that frequently observed in mass spectra resulted from disulfide linked peptides, and introduce an effective two-layer scoring scheme to evaluate the significance of the matching between spectrum and structure, based on which we have also developed a useful target-decoy strategy for providing quality control and reporting false discovery rate in the final results. Systematic experiments conducted on both low-complexity and high-complexity datasets demonstrated the efficiency of our proposed method for the identification of disulfide bonds from MS/MS spectra, and showed its potential in characterizing disulfide bonds at the proteome scale instead of just a single protein. Software is available for downloading at http://www.csd.uwo.ca/yliu766/. yliu766@uwo.ca. Supplementary data are available at Bioinformatics online.

Heteroatom-rich porous organic polymers constructed by benzoxazine linkage with high carbon dioxide adsorption affinity

We report the synthesis and characterization of a new type of porous organic polymers linked by benzoxazine. The polymers were readily synthesized by condensation reaction of diamines, triphenol and paraformaldehyde. The formation of the linkage and porous structures were studied by infrared spectroscopy, solid-state 13C-CP MAS NMR and nitrogen sorption measurements. The porosity study revealed the resultant polymers are porous materials with surface area as high as 231m2g−1. Benzoxazine backbone endows the polymers with abundant heteroatoms (N and O), which makes these polymers promising candidates for carbon dioxide adsorption and storage. We found that the best polymer showing the highest carbon dioxide adsorption up to 6.81wt% at 273K and 1bar, which is due to the most microporous structure and largest adsorption affinity. These results demonstrate a convenient approach to synthesize heteroatom-rich porous organic polymers for gas adsorption and storage.

Patrons, Parties, Political Linkage, and the Birth of Competitive-Authoritarianism in Africa

Abstract:Few scholars have taught us more about African voters, legislators, and legislatures than Joel Barkan. Drawing on Barkan’s analysis, the first part of this article argues that the African one-party state can be usefully viewed as a competitive-authoritarian system underpinned by a form of political linkage that allows for elements of coercion and competition. Building on this framework, the second part demonstrates that the political linkage structures that emerged in single-party systems such as those of Kenya, Senegal, and Tanzania have played an important role in shaping the dynamics of multiparty politics and the prospects for democratic reform.

Brokerage activities in regional innovation networks: the case of Daegu Technopark in Korea

ABSTRACTThis paper examines the concepts of local clusters and regional innovation networks and discusses the significance of ‘network brokerages’ in issues of local economic development and governance. The brokerage activities particularly affect the linkage structures and characteristics of regional networks. This research discusses each of these features in turn, and develops structural, divisional, or procedural models of them. The paper then turns to the empirical examples of brokerage activities by Daegu Technopark to illustrate the ways in which a local broker and related actors have been functioning. The analysis of Daegu Technopark case indicates that the positive results of network brokerages are mainly due to the proximity and willingness of a network broker to local firms, the making and operation of public programmes suitable to local conditions, differentiation to linkage purposes, the provision of contact opportunities, flexible manoeuvring and consensus-building efforts, and an active-minded leadership applicable to the circumstances. It is, of course, apprehended that Daegu Technopark shows some signs of potential limitations in the grasping and activating processes of regional potentials, such as a discontented aspect of managerial capability, a budgetary deficit, and a distorted process of performance evaluation system.