Present Structural Model Research Articles

Current Landscape of Psychologists in Academic Health Centers: Roles and Structural Models.

With mental health needs consistently increasing in our communities and medical centers, we want to ensure that institutions are aware of the benefit and value that psychologists bring to their system and provide several pathways for consideration and structure to understand how to support the salaries and careers of psychologists working within AHCs. Leadership and administration within Academic Health Centers (AHC) often do not understand the value and measurement of productivity for psychologists being added to the medical teams. The current article aims to present varied structural models and demonstrate how productivity is reviewed for psychologists across different institutions and departments. The authors will outline the many roles that psychologists serve within academic health centers as well as the value those roles bring to the system. The overarching goal is to provide an educational article that serves as a tool for recruitment of psychologists that leaders and faculty can refer to when approaching administration in AHCs to understand the systems and roles of psychologists within medical settings. This information can be utilized to help create new positions for psychologists, aid in recruitment efforts and provide transparency for faculty currently working within AHCs who may not be aware of the varied opportunities.

Observation of Bacteriophage Ultrastructure by Cryo-Electron Microscopy.

Transmission electron microscopy (TEM) is an ideal method to observe and determine the structure of bacteriophages. From early studies by negative staining to the present atomic structure models derived from cryo-TEM, bacteriophage detection, classification, and structure determination have been mostly done by electron microscopy. Although embedding in metal salts has been a routine method for virus observation for many years, the preservation of bacteriophages in a thin layer of fast frozen buffer has proven to be the most convenient preparation method for obtaining images using cryo-electron microscopy (cryo-EM). In this technique, frozen samples are observed at liquid nitrogen temperature, and the images are acquired using different recording media. The incorporation of direct electron detectors has been a fundamental step in achieving atomic resolution images of a number of viruses. These projection images can be numerically combined using different approaches to render a three-dimensional model of the virus. For those viral components exhibiting any symmetry, averaging can nowadays achieve atomic structures in most cases. Image processing methods have also evolved to improve the resolution in asymmetric viral components or regions showing different types of symmetries (symmetry mismatch).

A two-scale method to include essential screw connection behaviour in two-way coupled fire-structure simulations

PurposeSimulations exist for the prediction of the behaviour of building structural systems under fire, including two-way coupled fire-structure interaction. However, these simulations do not include detailed models of the connections, whereas these connections may impact the overall behaviour of the structure. Therefore, this paper proposes a two-scale method to include screw connections.Design/methodology/approachThe two-scale method consists of (a) a global-scale model that models the overall structural system and (b) a small-scale model to describe a screw connection. Components in the global-scale model are connected by a spring element instead of a modelled screw, and the stiffness of this spring element is predicted by the small-scale model, updated at each load step. For computational efficiency, the small-scale model uses a proprietary technique to model the behaviour of the threads, verified by simulations that model the complete thread geometry, and validated by existing pull-out experiments. For four screw failure modes, load-deformation behaviour and failure predictions of the two-scale method are verified by a detailed system model. Additionally, the two-scale method is validated for a combined load case by existing experiments, and demonstrated for different temperatures. Finally, the two-scale method is illustrated as part of a two-way coupled fire-structure simulation.FindingsIt was shown that proprietary ”threaded connection interaction” can predict thread relevant failure modes, i.e. thread failure, shank tension failure, and pull-out. For bearing, shear, tension, and pull-out failure, load-deformation behaviour and failure predictions of the two-scale method correspond with the detailed system model and Eurocode predictions. Related to combined load cases, for a variety of experiments a good correlation has been found between experimental and simulation results, however, pull-out simulations were shown to be inconsistent.Research limitations/implicationsMore research is needed before the two-scale method can be used under all conditions. This relates to the failure criteria for pull-out, combined load cases, and temperature loads.Originality/valueThe two-scale method bridges the existing very detailed small-scale screw models with present global-scale structural models, that in the best case only use springs. It shows to be insightful, for it contains a functional separation of scales, revealing their relationships, and it is computationally efficient as it allows for distributed computing. Furthermore, local small-scale non-convergence (e.g. a screw failing) can be handled without convergence problems in the global-scale structural model.

The Deformation Behavior and Failure Modes of Surrounding Rock after Excavation: A Experimental Study

The deformation and failure of the surrounding rock during roadway excavation often determine the choice of supporting methods. To study the deformation behavior and failure modes of the surrounding rock after excavation under unloading stress, structural model tests were carried out with a novel experimental device. The present structural model test using partial hollow thick-walled cylinder cement mortar specimen φ200 mm × 280 mm with a horizontal central circular hole of 60 mm diameter and the hollow height of 160 mm was conducted to investigate the deformation, failure characteristics, and AE response of a whole testing process from excavation to postunloading state. Experimental results revealed that the amount of deformation behind the surface is significantly higher than that in front of the surface, and the radial strain increases with the increase of the distance from the surface within the range affected by unloading. Furthermore, the unloading rate has a little effect on the radial deformation of the surrounding rock in front of the surface, but has a substantial effect on the radial deformation behind the excavation surface. The peak value of the strain rate at the unloading rate of 2 MPa/s is much higher than that at the unloading rate of 0.1 MPa/s. According to AE results and the failure of opening the boundary, the increase of unloading rate triggers and exacerbates the damage of the specimen under high in situ stress conditions. The surrounding rock expanded to the inner hollow, accompanied by large dilation and volume changes, and it resulted in the shrinkage of the hole diameter. A large number of rock slices are generated at the opening curved free surface and then fell off, whose morphology is similar to the rock blocks that fell off after caving failure and rock burst in situ field. The results show that the system can accurately simulate the mechanical response and acoustic emission response of the excavated surrounding rock, which provides a new experimental method for further study of the unloading response of the surrounding rock.

Flutter analysis of delaminated composite box-beam using higher-order kinematics

The flutter analysis of delaminated box-beam has been performed using the Lagrange polynomial in Carrera Unified Formulation (CUF) framework. In this formulation, the cross-sectional displacement field of each layer can be defined by the arbitrary displacement variables using the Layerwise (LW) approach. The cross-section of the present structural model is discretized using the quadratic elements. The unsteady aerodynamic contribution has been obtained using Theodorsen’s lift function. Subsequently, the structural and aeroelastic model has been defined using the Principle of Virtual Displacement (PVD) in the CUF framework. For verification of the present model, free variation analysis has been performed for delaminated and healthy composite structures. Furthermore, a composite box-beam model with single and multiple delaminations has been developed to perform free vibration and flutter analysis. This study supports the capability of the CUF model to perform flutter analysis of the complex model with multi-delaminated composite box-beam.

Geometrically nonlinear dynamic analysis of variable stiffness composite laminated and sandwich shell panels

The nonlinear free and forced vibration analyses of variable stiffness composite laminated (VSCL) and sandwich shell panels having curvilinear fibres, not yet reported in literature, are conducted based on a higher-order theory. The present structural model considers a third-order shear deformation theory incorporating Murakami zig-zag effects. The analyses are performed using C0 nine-noded isoparametric element with thirteen degrees of freedom and geometrical nonlinearity is included through von Kármán nonlinear strain–displacement relations. The free and forced vibrational responses of the VSCL are established using the eigenvalue solutions and Newmark’s time integration technique, respectively. The results obtained using the present finite element formulation are compared with the available three-dimensional exact and two-dimensional analytical and numerical solutions for establishing the validity of the model. The fundamental frequencies and nonlinear transient deflections of VSCL and sandwich spherical and cylindrical shell panels are evaluated considering the effects of curvilinear fibre path, curvature ratio, number of layers and lamination configuration.

Carnitine palmitoyl transferase I: Conformational changes induced by long-chain fatty acyl CoA ligands

The Carnitine Palmitoyltranferase I (CPT1) catalyzes the rate-limiting step of long-chain fatty acid (LCFA) mitochondrial β-oxidation. The enzyme promotes the conjugation of LCFA with l-carnitine, which allows LCFA to enter the mitochondria matrix. The structural features involved in CPT1 and LCFA-CoA interactions have not been fully elucidated, mainly due to the absence of CPT1 crystallographic data. Previous studies reported important residues (Lys556, Lys560, and Lys561) crucial to the CPT1 mechanism. Nonetheless, these studies have not explored the LCFA bindings. Using molecular modeling strategies, we aimed to understand the conformational changes in CPT1 structure induced by LCFA-CoA. For this purpose, a tridimensional CPT1A model was built by homology modeling using CRAT protein (PBD:1t7q, resolution 1.8 Å) as a template. We simulated the CPT1 structure in the presence and absence of LCFA-CoA by molecular dynamics (MD). By applying a principal component analysis (PCA), two states of apostructure CPT1 based on CoA-Loop (688–711) were observed. In contrast, just one state was evidenced along with smaller conformational subspaces in ligand-complexed simulations using LCFA-CoA. The CoA moiety of ligands interacts with charged residues, namely Lys560, Lys556, Arg563, and Arg645. The frequency of interactions observed for each of these residues is <60% of simulation time, suggesting a dynamic profile of interactions in synergy with long-chain carbon interactions over α-I (478–492). Collectively, these features may be associated with the catalytic conformation of LCFA-CoA to CPT1a. Further calculations of free-energy for different fatty acids, such as alpha-linolenic (ALA), gamma-linolenic (GLA), and arachidonic (ARA) acids, yielded energy values ranging from −76.9 ± 15.9 to −68.5 ± 10.0 kcal mol−1. In conclusion, the present structural model and simulations provide molecular-level insights into LCFA-CoA and CPT1a interactions. These findings may help to further knowledge on the conformational changes of CPT1a induced by LCFA-CoA derivates.

Biomedical overview of melanin. 2. Updating molecular modeling, synthesis mechanism, and supramolecular properties regarding melanoma therapy

Melanins represent one of the most ancient and important group of natural macromolecular pigments. They have multiple biological roles in almost all organisms across the Phyla, examples being photoprotection, anti-oxidative action, radical scavenger activity, and heavy metal removal. From the biomedical point of view, melanocytes are involved in the origin of melanoma tumors, and the main therapeutic advances for their treatment have been revised in Part 1 of this review. The chemical structure of eumelanin is a biological concern of great importance, and therefore, exploring theoretical molecular models and synthesis mechanisms will be here described, as well as molecular orbital features and supramolecular organization, which are responsible for the key properties that make these biological pigments so important, and so fascinating. Ultimately, this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin, in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied.

Parenthetical constructions: structure and semantics

The present article studies structural models and semantic content of parenthetical insertions in modern English fiction. The relevance of the research is determined by its focus on the study of the corpus of parenthesis in the modern English language within the framework of the general science issue ‘man and the language’. The study is novel in that it is carried out using evidence from modern English literature (texts written by S. King, J. Barnes, D. Mitchell, J. Coe, Laura van den Berg). This article will be of interest to researchers dealing with problems of parenthesis in modern English and to specialists in semantic syntax.

The Online Shoppers’ Behavioral Intentions, E-Satisfaction, the Pathway to Repurchase Behavior: A Quantitative Analysis

Online shopping is catching new heights, the repetition of consumer buying behavior is still a challenge for businesses. The current study investigates the antecedents of consumer repurchase intentions that bridge consumer repurchase behavior through e-satisfaction by extending the technology acceptance model. A questionnaire was developed with additional constructs of consumer behavior after an extensive review of the literature. A total of 607 usable responses were received from Pakistani university students (the regular online shoppers). Composite, discernment validity, loadings, and average variance extracted were employed to measure the scale's reliability and validity. Structural equation modeling is applied using SmartPLS to present structural and measurement models. The current study results revealed that all hypotheses were statistically supported except product and financial risk towards behavioral intentions. Notably, the extended version of the technology acceptance model, e-satisfaction, and behavioral intentions significantly contributing to consumer repurchase behavior. This study's results can help both the website developers and the organizations doing business online to contemplate the significant factors that urge consumers to purchase online time and again, thus leading to increased profits. Moreover, this research offers a robust foundation regarding the features a website should trigger consumers to buy. Consumers repurchase behavior through e-satisfaction and consumer behavioral intention. This study serves as a baseline in understanding how the exogenous variables in the information system, marketing, and social psychology impact the endogenous variable, repurchase behavior, within the online shopping context.

Construction of a computational mechanical model of bronchi for practical simulation of the optimal positive intrathoracic pressure conditions during general thoracic surgery.

Thoracic CO2 insufflation with positive intrathoracic pressure is usually effective during thoracoscopic surgery, however, lung collapse is sometimes insufficient. We hypothesized that inappropriate bronchial collapse might cause this unsuccessful lung collapse. The objective of this study was to construct a computational mechanical model of bronchi for practical simulation to discover the optimal conditions of positive intrathoracic pressure during thoracoscopic surgery. Micro-focus high-resolution X-ray computed tomography measurements of lungs from just-slaughtered swine were extracted, and the three-dimensional geometries of the bronchi under pressurized and depressurized conditions were measured accurately. The mechanical properties of the bronchus were also measured. Computational fluid dynamics (CFD) and computational structural mechanics (CSM) analyses were conducted. The CSM results indicated that the present structural model could simulate bronchial occlusion. The CFD results showed that airflows from pressed lung alveoli might cause low-internal-pressure regions when suddenly or heterogeneously pushed airflow was injected from a small branching bronchus to a large bronchus. A preliminary computational mechanical model of bronchi was constructed. We demonstrated the performance of the mechanical model of bronchi in rough simulations of bronchial occlusions. However, this model should be verified further using human data to facilitate its introduction to clinical use.

Structural and Semantic Features of Parenthetical Constructions: Evidence from Modern English Literature

The present article studies structural models and semantic content of parenthetical insertions in modern English fiction. The relevance of the research is determined by its focus on the study of the corpus of parenthesis in the modern English language within the framework of the general science issue ‘man and the language’. The study is novel in that it is carried out using evidence from modern English literature (texts written by S. King, J. Barnes, I. McEwan, D. Mitchell, J. Coe). The new language material and the use of methods of component, distributive, transformational and contextual analysis as well as the method of quantitative calculations allowed us to deepen the existing understanding of the structure and semantics of parenthetical constructions in the English language. This article will be of interest to researchers dealing with problems of parenthesis in modern English and to specialists in semantic syntax.

Highly mismatched III–V semiconductor alloys applied in multiple quantum well photovoltaics

Adding dilute concentrations of nitrogen (N) or bismuth (Bi) into conventional III–V semiconductor alloys causes a large bowing of the bandgap energy due to the modification of the electronic band structure. This behaviour has attracted significant interest due to the resulting optical and electronic properties. Firstly, the authors present theoretical band structure models for GaAs-based dilute nitride, dilute bismide and dilute bismide-nitride alloys and then use them within current continuity equations to show the photovoltaic behaviour. To describe the band structures of these highly mismatched III–V semiconductor alloys, the authors introduce a 10-, 12- and 14-band k ⋅ p Hamiltonian for dilute nitride, dilute bismide and dilute bismide-nitride semiconductors, respectively. The authors then use this approach to analyse GaBiAs multi-quantum well p-i-n structures for photovoltaic performance. Through theoretical analysis the authors can: (i) elucidate important trends in the properties and photovoltaic performance of GaBiAs QW structures and (ii) comment generally on the suitability of GaBiAs alloys and heterostructures for applications in multi-junction solar cells. In particular, the authors identify and quantify the limitations associated with current GaBiAs solar cells, and describe the improvements in performance that can be expected pending further development of this emerging class of devices.

Observation of Bacteriophage Ultrastructure by Cryo-electron Microscopy.

Transmission Electron Microscopy (TEM) is an ideal method to observe and determine the structure of bacteriophages. From early studies by negative staining to the present atomic structure models derived from cryo-TEM, bacteriophage detection, classification, and structure determination has been mostly done by electron microscopy. Although embedding in metal salts has been a routine method for virus observation for many years, preservation of bacteriophages in a thin layer of fast frozen buffer has proven to be a most convenient preparation method for obtaining images using cryo-electron microscopy (cryo-EM). In this technique, frozen samples are observed at liquid nitrogen temperature and the images are acquired using different recording media. The incorporation of direct electron detectors has been a fundamental step to achieve atomic resolution images of a number of viruses. These projection images can be numerically combined using different approaches to render a three-dimensional model of the virus. For those viral components exhibiting any symmetry, averaging procedures help to render near-atomic resolution structures.

Molstack-Interactive visualization tool for presentation, interpretation, and validation of macromolecules and electron density maps.

Our understanding of the world of biomolecular structures is based upon the interpretation of macromolecular models, of which ∼90% are an interpretation of electron density maps. This structural information guides scientific progress and exploration in many biomedical disciplines. The Protein Data Bank's web portals have made these structures available for mass scientific consumption and greatly broaden the scope of information presented in scientific publications. The portals provide numerous quality metrics; however, the portion of the structure that is most vital for interpretation of the function may have the most difficult to interpret electron density and this ambiguity is not reflected by any single metric. The possible consequences of basing research on suboptimal models make it imperative to inspect the agreement of a model with its experimental evidence. Molstack, a web-based interactive publishing platform for structural data, allows users to present density maps and structural models by displaying a collection of maps and models, including different interpretation of one's own data, re-refinements, and corrections of existing structures. Molstack organizes the sharing and dissemination of these structural models along with their experimental evidence as an interactive session. Molstack was designed with three groups of users in mind; researchers can present the evidence of their interpretation, reviewers and readers can independently judge the experimental evidence of the authors' conclusions, and other researchers can present or even publish their new hypotheses in the context of prior results. The server is available at http://molstack.bioreproducibility.org.

Application of Molecular Imaging Equipment PET/MRI

To compare the principles and system frameworks on PET and MRI systems. The functional characteristics and present adoptive structural models of PET/MRI as molecular imaging equipment is introduced in particular. To compare several update techniques of attenuation correction for PET image with MRI parameters and to expatiate their deficiencies. The advantages on PET/MRI clinical applications and the future development of PET/MRI are introduced briefly.

Structure and stability of pseudo-cubic tetragonal boron

Pseudo-cubic tetragonal boron, which may be another form of boron allotropes, has recently been discovered under high pressure and high temperature conditions. In this paper, the structure of pseudo-cubic tetragonal boron is studied by density-functional-theory (DFT) calculation. The structure is abnormal compared with other boron allotropes in many respects, making it difficult to comprehend. The lattice is very close to a cubic lattice, such that the icosahedra are largely distorted along the c-axis. Such distortions are normally not favorable for boron crystals; in fact, the present calculations supported this. The reported positions of partially occupied interstitial sites render the intericosahedral bonds unusually long or short, which were again not supported by the present calculations. Furthermore, the potential of involving impurities is unlikely in terms of the formation energy and lattice parameters. Therefore, the structure of pseudo-cubic tetragonal boron was not proven by calculation, despite this extensive study. Something may be overlooked in the present structural model, or something unusual may have happened in this structure, the solution of which is left as an open question.

Methods of Multi-criteria Optimization in Problems of Simulation of Trucking Industry

Efficiency of a transport enterprise can be substantially enhanced by optimization methods at the stages of synthesis, analysis and decision-taking, which makes it possible to obtain, in specific situation, the best of possible solutions. The simulation of motor transport enterprise's operation is closely associated with using vector numeric schemes that practically present structural and parametric models of motor transport enterprise's functions. This is connected with the fact that motor transport enterprises are defined by a relatively large quantity of their specific and individual properties that become sophisticatedly interdependent in the course of their functioning.The article describes the basic features and methods of multi-criterion optimization in simulating the motor transport enterprises’ operations.

Response Analysis of Blast Impact Loading of Metal-foam Sandwich Panels

The study of the structural blastworthiness is aimed to design efficient structures to protect the personnel inside the armor vehicle. Designing blastworthy structures requires not only high strength material, but also the capability of the structure to absorb the blast impact energy. The use of the sandwich construction with martensitic steel as the armor material and metallic foam as the energy absorber is promising to obtain the lightweight blast impact resistant structure. Recent development in military vehicle application has shown that the high strength material alone is not sufficient to protect the military personnel. This is due the fact that many injury and fatality of the military personnel still occurred even though the military vehicle still intact in the event of the blast impact event. Therefore, it is needed to design structures which have the capability to protect the vehicle subjected to the blast impact loading and to reduce the injury and fatality risk of the military personnel. The present blastworthy structural model with sandwich metal-foam plate construction is examined using non-linear finite element. The structural responses in terms of the displacement, velocity and acceleration is studied. Blast impact load is modeled using blast load equation by defining the charge and standoff distance. The sandwich structure is modeled as the shell and solid elements, using the Johnson-Cook and Crushable Foam material constitutive models. Parametric studies were carried out by varying panel thickness, specific material and foam density for certain blast load and impact stand-off distance. The objective of the parametric study is to analyze the dynamic responses of the sandwich structure with respect to the displacement, velocity, absorbed energy, and acceleration. The result obtained indicate that the metal-foam sandwich construction can be developed as the blastworthy component with high structural efficiency. The efficiency of metal foam to protect against blast load is shown by the absorbed energy respons. © 2016 The Authors. Published by Elsevier Ltd.

Kein Sprichwort ohne Strukturformel? Vorgeprägte syntaktische Schemata in aktuell gebräuchlichen bulgarischen Sprichwörtern

Abstract In general, the majority of native or near-native speakers of a certain language can easily identify a sentence as a proverb. They are able to do this due to different structural features, among others. These specific syntactic structures appear quite frequently in proverbs and serve as a warning sign that the particular text is deviant from the surrounding discourse and is, most probably, a proverb. The so-called proverbial formulae, e.g. Better X, than Y; When you X (you) Y; No X, no Y etc., are considered to be one of the most easily recognizable proverbial characteristics. They often serve as basic syntactic models and lend themselves readily for the insertion of new contents (cf. Taylor 1985: 16). In his study Structural Aspects of Proverbs, Mac Coinnigh has shown that proverbs from different languages, for instance English, Estonian, Finnish, German and Swedish, share the same or a very similar syntactic architecture (Mac Coinnigh 2015: 117–120). The Irish linguist, however, did not consider examples from the Bulgarian language. Therefore, one of the main aims of the present paper is to investigate which of the structural models recorded in previous paremiological works (Kuusi 1987 (1966); Röhrich and Mieder 1977; Permjakov 1979; Mieder 2006a and 2012 etc.) can be identified in traditional Bulgarian proverbs and in what frequency. Moreover, the study intends to test the widespread hypothesis that humorous proverb innovations and variations (anti-proverbs) are often created based on proverbial formulae (Litovkina 2015: 333). For the purposes of the study, two corpora of 649 proverbs and 370 anti-proverbs were analyzed. The corpora have been previously built by Hrisztova-Gotthardt and Gotthardt (Hrisztova-Gotthardt 2006 and 2010b; Hrisztova-Gotthardt and Gotthardt 2011 and 2012). The qualitative analysis has shown that 14 out of the 16 structural formulae listed by Röhrich and Mieder (1977) and Mieder (2006a and 2012) can be found in Bulgarian proverbs. The most common formula was He who Xs, Ys, serving as a syntactic model for 48 different commonly used proverbs. In case of anti-proverbs, the present structural model could be clearly identified in 30 out of 370 texts. The most prominent formulae were He who Xs, Ys, X is Y and Better X than Y.