Integrative Structural Modeling Research Articles

Understanding the determinants of human computation game acceptance

Purpose – Human computation games (HCGs) that blend gaming with utilitarian purposes are a potentially effective channel for content creation. The purpose of this paper is to investigate the driving factors behind players’ adoption of HCGs through a music video tagging game. The effects of perceived aesthetic experience (PAE) and perceived output quality (POQ) on HCG acceptance are empirically examined. Design/methodology/approach – An integrative structural model is developed to explain how hedonic and utilitarian factors, including PAE and POQ, working with another salient factor – perceived usefulness (PU) – affect the acceptance of HCGs. The structural equation modeling method is used to verify the proposed model with data from 124 participants. Findings – Results show that PAE is the strongest predictor of HCGs adoption. PU has a significant impact on individuals’ attitude toward HCGs. POQ is a salient predictor of PU and PAE, and its indirect effect on attitude is significance. Originality/value – From an academic point of view, this study provides a good understanding of the driving factors behind player acceptance of HCGs and adds new knowledge to games with utilitarian purposes. It is also one of the first to describe the components of game enjoyment with a taxonomy of aesthetic experiences. From the practical perspective, the investigation of the specific factors behind adoption of HCGs provides specific guidelines for their design and evaluation.

Peptide dimer structure in an Aβ(1–42) fibril visualized with cryo-EM

Alzheimer's disease (AD) is a fatal neurodegenerative disorder in humans and the main cause of dementia in aging societies. The disease is characterized by the aberrant formation of β-amyloid (Aβ) peptide oligomers and fibrils. These structures may damage the brain and give rise to cerebral amyloid angiopathy, neuronal dysfunction, and cellular toxicity. Although the connection between AD and Aβ fibrillation is extensively documented, much is still unknown about the formation of these Aβ aggregates and their structures at the molecular level. Here, we combined electron cryomicroscopy, 3D reconstruction, and integrative structural modeling methods to determine the molecular architecture of a fibril formed by Aβ(1-42), a particularly pathogenic variant of Aβ peptide. Our model reveals that the individual layers of the Aβ fibril are formed by peptide dimers with face-to-face packing. The two peptides forming the dimer possess identical tilde-shaped conformations and interact with each other by packing of their hydrophobic C-terminal β-strands. The peptide C termini are located close to the main fibril axis, where they produce a hydrophobic core and are surrounded by the structurally more flexible and charged segments of the peptide N termini. The observed molecular architecture is compatible with the general chemical properties of Aβ peptide and provides a structural basis for various biological observations that illuminate the molecular underpinnings of AD. Moreover, the structure provides direct evidence for a steric zipper within a fibril formed by full-length Aβ peptide.

Geostatistical modeling for fine reservoir description of Wei2 block of Weicheng oilfield, Dongpu depression, China

The Wei2 block of Weicheng oilfield is characterized by complicated structure mainly caused by high degree of fault development. Multiple reservoir types are found in this block and the reservoir heterogeneity is severe. The oil and gas reservoirs have already stepped into the stagnant stage of a great water-cut degree together with a rapid production decline rate. Thereby, both stabilizing the oil and gas production and optimizing adjustment for further exploitation make it urgent for geomodelers to build a useful model to predict the inter-well parameters and the distribution of the remaining oil and gas. A three-dimensional geological model established with the help of stochastic modeling technique may provide a perfect window and carrier for fine structure interpretation and reservoir heterogeneity description, compared with a traditional two-dimensional model. Hence, based on stratigraphical layering points, significant surfaces and fault points as well seismic interpretation, an integrated structure model is developed. Using the truncated Gaussian simulation and taking the existing geological maps as references, the sedimentary microfacies model was successfully constructed. Through the use of sequential Gaussian simulation method and the facies-controlled modeling method, the reservoir physical properties are populated. Meanwhile, the comparison between facies-controlled and non-facies-controlled property models indicates that the former is more loyal to previous researching and the representation of heterogeneity is ideal. Finally, the ideas of sample density and reserves fitting are proposed to evaluate the practicability and accuracy of the property models.

Molecular Architecture and Function of the SEA Complex, a Modulator of the TORC1 Pathway

The TORC1 signaling pathway plays a major role in the control of cell growth and response to stress. Here we demonstrate that the SEA complex physically interacts with TORC1 and is an important regulator of its activity. During nitrogen starvation, deletions of SEA complex components lead to Tor1 kinase delocalization, defects in autophagy, and vacuolar fragmentation. TORC1 inactivation, via nitrogen deprivation or rapamycin treatment, changes cellular levels of SEA complex members. We used affinity purification and chemical cross-linking to generate the data for an integrative structure modeling approach, which produced a well-defined molecular architecture of the SEA complex and showed that the SEA complex comprises two regions that are structurally and functionally distinct. The SEA complex emerges as a platform that can coordinate both structural and enzymatic activities necessary for the effective functioning of the TORC1 pathway.

Uncertainty in integrative structural modeling.

Integrative structural modeling uses multiple types of input information and proceeds in four stages: (i) gathering information, (ii) designing model representation and converting information into a scoring function, (iii) sampling good-scoring models, and (iv) analyzing models and information. In the first stage, uncertainty originates from data that are sparse, noisy, ambiguous, or derived from heterogeneous samples. In the second stage, uncertainty can originate from a representation that is too coarse for the available information or a scoring function that does not accurately capture the information. In the third stage, the major source of uncertainty is insufficient sampling. In the fourth stage, clustering, cross-validation, and other methods are used to estimate the precision and accuracy of the models and information.

Molecular Architecture of the 40S⋅eIF1⋅eIF3 Translation Initiation Complex

SummaryEukaryotic translation initiation requires the recruitment of the large, multiprotein eIF3 complex to the 40S ribosomal subunit. We present X-ray structures of all major components of the minimal, six-subunit Saccharomyces cerevisiae eIF3 core. These structures, together with electron microscopy reconstructions, cross-linking coupled to mass spectrometry, and integrative structure modeling, allowed us to position and orient all eIF3 components on the 40S⋅eIF1 complex, revealing an extended, modular arrangement of eIF3 subunits. Yeast eIF3 engages 40S in a clamp-like manner, fully encircling 40S to position key initiation factors on opposite ends of the mRNA channel, providing a platform for the recruitment, assembly, and regulation of the translation initiation machinery. The structures of eIF3 components reported here also have implications for understanding the architecture of the mammalian 43S preinitiation complex and the complex of eIF3, 40S, and the hepatitis C internal ribosomal entry site RNA.

Finding the right fit: chiseling structures out of cryo-electron microscopy maps

Cryo-electron microscopy is a central tool for studying the architecture of macromolecular complexes at subnanometer resolution. Interpretation of an electron microscopy map requires its computational integration with data about the structure's components from all available sources, notably atomic models. Selecting a protocol for EM density-guided integrative structural modeling depends on the resolution and quality of the EM map as well as the available complimentary datasets. Here, we review rigid, flexible, and de novo integrative fitting into EM maps and provide guidelines and considerations for the design of modeling experiments. Finally, we discuss efforts towards establishing unified criteria for map and model assessment and validation.

Why people use Twitter: social conformity and social value perspectives

Purpose – Based on social conformity and social value perspectives, the authors aim to empirically examine the critical role of social influences on Twitter user behaviour. Design/methodology/approach – An integrative structural model is developed to explain how social influences, which are divided into social conformity and social values, work with other salient factors such as the utilitarian and hedonic values to affect the use of Twitter. The partial least square method was used to verify the proposed model with usable data from 204 adult Korean Twitter users. Findings – Social conformity positively affects the frequent use of Twitter and it is mediated through perceived values such as the hedonic, utilitarian and social appearance values associated with Twitter use. While social appearance negatively affected the trustworthiness of information shared on Twitter, the social capital effect on Twitter use was insignificant. Research limitations/implications – This study has some limitations for general applicability of the results: the samples include only adult users in Korea, and it is a cross-sectional study for a specific social networking service. This study theoretically disentangles the complicated nature of social influences by proposing two distinct constructs (social conformity and social values) and empirically verifying their significant roles in Twitter use. Practical implications – Practitioners should recognise that the hedonic value of Twitter is the key factor that affects both the quantity and quality of information shared on Twitter. In addition user motivations for pursuing social appearance in SNSs might cause a user to distort the information that they produce. Originality/value – This study provides unique implications related to the role of social conformity, social values and user behaviour on Twitter.

Finite Element Analysis on Integral Structure of Light Steel Temporary Buildings

Light steel temporary building is commonly used in the construction site, with advantages on simple structure, repeat used and small deadweight. There are still not enough researches and relevant standards to conduct the design and construction of the buildings. In order to precede to theoretical study on integral structure of light steel temporary buildings a method which used to set up finite element analysis model about integral structure of light steel temporary buildings was proposed in this paper. The method is based on finite element analysis software, Ansys. Using this method a monolayer integral structure, a two-story integral structure and a trilaminar integral structure model were set up. Lateral displacement under design load of the integral structure was solved out by these finite element models.

Effects of early maternal distress and parenting on the development of children's self-regulation and externalizing behavior

Emotional distress experienced by mothers increases young children's risk of externalizing problems through suboptimal parenting and child self-regulation. An integrative structural equation model tested hypotheses that mothers' parenting (i.e., low levels of inductive discipline and maternal warmth) would mediate adverse effects of early maternal distress on child effortful control, which in turn would mediate effects of maternal parenting on child externalizing behavior. This longitudinal study spanning ages 3, 6, and 10 included 241 children, mothers, and a subset of teachers. The hypothesized model was partially supported. Elevated maternal distress was associated with less inductive discipline and maternal warmth, which in turn were associated with less effortful control at age 3 but not at age 6. Inductive discipline and maternal warmth mediated adverse effects of maternal distress on children's effortful control. Less effortful control at ages 3 and 6 predicted smaller relative decreases in externalizing behavior at 6 and 10, respectively. Effortful control mediated effects of inductive discipline, but not maternal warmth, on externalizing behavior. Findings suggest elevated maternal distress increases children's risk of externalizing problems by compromising early parenting and child self-regulation.

All-Atom Ensemble Modeling to Analyze Small-Angle X-Ray Scattering of Glycosylated Proteins

The flexible and heterogeneous nature of carbohydrate chains often renders glycoproteins refractory to traditional structure determination methods. Small-angle X-ray scattering (SAXS) can be a useful tool for obtaining structural information of these systems. All-atom modeling of glycoproteins with flexible glycan chains was applied to interpret the solution SAXS data for a set of glycoproteins. For simpler systems (single glycan, with a well-defined protein structure), all-atom modeling generates models in excellent agreement with the scattering pattern and reveals the approximate spatial occupancy of the glycan chain in solution. For more complex systems (several glycan chains, or unknown protein substructure), the approach can still provideinsightful models, though the orientations of glycans become poorly determined. Ab initio shape reconstructions appear to capture the global morphology of glycoproteins but in most cases offer littleinformation about glycan spatial occupancy. The all-atom modeling methodology is available as a web server at http://salilab.org/allosmod-foxs.

On the relationships between logistics service deliverables, customer satisfaction and loyalty in industrial supply chains

This study aims at identifying the main dimensions of logistics service quality (LSQ) and analysing their effects on satisfaction and loyalty in B2B settings. For this purpose an integrative structural model of logistics service performance impact on satisfaction and loyalty is proposed and tested in a self-built logistics setting. On evidence drawn, through a dedicated research instrument, from 213 companies in Greece, the effects of outcome and process elements of LSQ on satisfaction and loyalty are assessed. Results show that customers’ perception about their suppliers’ LSQ level is shaped by both outcome and process elements while outcome quality is further affected by process quality. Both dimensions impact satisfaction with outcome quality being the main driver. LSQ dimensions and satisfaction directly affect loyalty. Satisfaction’s hypothesised enhancing role on the association between LSQ dimensions and loyalty is confirmed. Finally, several implications of the findings are discussed and further research directions are provided.

Putting the Pieces Together: Integrative Modeling Platform Software for Structure Determination of Macromolecular Assemblies

A set of software tools for building and distributing models of macromolecular assemblies uses an integrative structure modeling approach, which casts the building of models as a computational optimization problem where information is encoded into a scoring function used to evaluate candidate models.

Integrative structural modeling with small angle X-ray scattering profiles

Recent technological advances enabled high-throughput collection of Small Angle X-ray Scattering (SAXS) profiles of biological macromolecules. Thus, computational methods for integrating SAXS profiles into structural modeling are needed more than ever. Here, we review specifically the use of SAXS profiles for the structural modeling of proteins, nucleic acids, and their complexes. First, the approaches for computing theoretical SAXS profiles from structures are presented. Second, computational methods for predicting protein structures, dynamics of proteins in solution, and assembly structures are covered. Third, we discuss the use of SAXS profiles in integrative structure modeling approaches that depend simultaneously on several data types.

The relationship between measures of impulsivity and alcohol misuse: an integrative structural equation modeling approach.

Higher levels of impulsivity have been implicated in the development of alcohol use disorders. Recent findings suggest that impulsivity is not a unitary construct, highlighted by the diverse ways in which the various measures of impulsivity relate to alcohol use outcomes. This study simultaneously tested the following dimensions of impulsivity as determinants of alcohol use and alcohol problems: risky decision making, self-reported risk-attitudes, response inhibition, and impulsive decision making. Participants were a community sample of nontreatment seeking problem drinkers (n = 158). Structural equation modeling (SEM) analyses employed behavioral measures of impulsive decision making (delay discounting task [DDT]), response inhibition (stop signal task [SST]), and risky decision making (Balloon Analogue Risk Task [BART]), and a self-report measure of risk-attitudes (domain-specific risk-attitude scale [DOSPERT]), as predictors of alcohol use and of alcohol-related problems in this sample. The model fits well, accounting for 38% of the variance in alcohol problems, and identified 2 impulsivity dimensions that significantly loaded onto alcohol outcomes: (i) impulsive decision making, indexed by the DDT; and (ii) risky decision making, measured by the BART. The impulsive decision-making dimension of impulsivity, indexed by the DDT, was the strongest predictor of alcohol use and alcohol pathology in this sample of problem drinkers. Unexpectedly, a negative relationship was found between risky decision making and alcohol problems. The results highlight the importance of considering the distinct facets of impulsivity to elucidate their individual and combined effects on alcohol use initiation, escalation, and dependence.

Assessing asymmetric response effect of behavioral intention to service quality in an integrated psychological decision-making process model of intercity bus passengers: a case of Taiwan

This study introduces the concept of loss aversion to consumer behavioral intention at the personal psychological level to develop an integrative structural equation model for analyzing traveler psychological decision making. In this model, the relationship between behavioral intention and service quality is a non-smooth function based on the theory of loss aversion. The expectation service quality in the SERVQUAL model proposed by Parasuraman, Zeithaml, and Berry (PZB) serves as a reference point. This model can be applied to analyze the effect of non-smooth response of behavioral intention to service quality in a traveler psychological decision-making process model. Intercity travel among cities in Taiwan is used as an empirical example. Data were gathered in cities in Taiwan via a questionnaire survey, and the model was tested using path analysis performed by LISREL. The empirical result shows that all causal relationships are statistically significant. Service quality loss influences repurchase intention more than does Service quality gain. Finally, this study concludes by discussing managerial implications and suggesting directions for future research.

Interpersonal trust between marketing and R&D during new product development projects

PurposeThe primary objective of this research is to test a model examining interpersonal trust between marketing managers and R&D managers during new product development projects.Design/methodology/approachIn this study interpersonal trust as a bi‐dimensional construct with cognitive and affective components is conceptualised. The authors' integrative structural model specifies Weber's structural/bureaucratic dimensions – formalisation and centralisation to predict three communication dimensions, communication frequency, quality, and bi‐directionality. In turn these communication dimensions are used to predict cognition‐based trust, and affect‐based trust. In addition, the paper models the direct effects of the three communication dimensions on a dependent variable – perceived relationship effectiveness. The hypothesised model consists of 16 hypotheses, seven of which relate to the two focal interpersonal trust constructs. The measures were tested and a structural model estimated by using PLS. Data were provided by 184 R&D managers in Australia, reporting on their working relationship with a counterpart marketing manager during a recent product development project.FindingsThe hypothesized model has high explanatory power and it was found that both trust dimensions strongly influenced the effectiveness of marketing/R&D relationships during new product development, with cognition‐based trust having the strongest impact. The results also reveal which forms of communication help to build interpersonal trust. The most powerful effect was from communication quality to cognition‐based trust. The next strongest effects were from bi‐directional communication, which was a strong predictor of affect‐based trust, and a somewhat weaker predictor of cognition‐based trust. Interestingly, the direct effects of our three communication behaviours on relationship effectiveness were modest, suggesting that their relationship building effects are largely indirect. Last, it is revealed that bureaucratic means of control on product development projects have mixed effects. As expected, centralisation reduces cross‐functional communication. In contrast, formalisation has a positive effect during product development, as it stimulates both the frequency and bi‐directionality of communication between marketing managers and R&D managers on these projects.Originality/valueThis is the first study to treat interpersonal trust as the focal construct in marketing/R&D relationships during new product development. Moreover, it is the only study of marketing/R&D relationships to conceptualise, measure, and model two underlying dimensions of interpersonal trust (cognition‐based trust, and affect‐based trust). Our study also integrates aspects of Weber's theory of bureaucracy, with interaction theory, and demonstrates the strong links between these theoretical frameworks.

Long-term posttreatment functioning among patients with unipolar depression: an integrative model.

This study tested an integrative structural equation model of posttreatment functioning among 165 depressed patients followed for an average of 9 years after the end of an episode of treatment. The model examined (a) the link between life change and psychosocial resource change and (b) the role of resource change in mediating the relationship between life change and change in depression. An increase in the preponderance of negative over positive life events was associated with a decline in resources and an increase in depressive symptoms. A decline in resources was associated with an increase in depressive symptoms. The association between changes in events and depressive symptoms was completely mediated through resource change. These findings indicate that life stressors contribute to posttreatment depression through an erosion of personal and social resources.

Social Support

Life transitions, such as university attendance, entail the reconstruction of relations between the individual and the environment. This study aimed to explore how perceptions of social support changed across time during the first semester of university, and how social support, coping strategies, and adjustment were interrelated among 390 first-year students in Beijing, China. Results indicated that overall levels of social support among students did not change significantly across the first term, but that support from different sources (parents, peers, teachers, siblings) showed distinctive patterns of change. Support was positively related to adjustment and to coping skills in a dynamic way, and an integrative structural equations model showed that the role of social support operated both directly in relation to adjustment and indirectly through its relations to coping styles. These findings were related both to previous research on the transition to university in the West and to unique factors within the Chinese context.

Long-term posttreatment functioning among patients with unipolar depression: An integrative model.

This study tested an integrative structural equation model of posttreatment functioning among 165 depressed patients followed for an average of 9 years after the end of an episode of treatment. The model examined (a) the link between life change and psychosocial resource change and (b) the role of resource change in mediating the relationship between life change and change in depression. An increase in the preponderance of negative over positive life events was associated with a decline in resources and an increase in depressive symptoms. A decline in resources was associated with an increase in depressive symptoms. The association between changes in events and depressive symptoms was completely mediated through resource change. These findings indicate that life stressors contribute to posttreatment depression through an erosion of personal and social resources.