Collective Intelligence Under a Volatile Task Environment: a Behavioral Experiment Using Social Networks and Computer Simulations

Collective intelligence in our highly-connected world is a topic of interdisciplinary interest. Previous research has demonstrated that social network structures can affect collective intelligence, but the potential network impact is unknown when the task environment is volatile (i.e., optimal behavioral options can change over time), a common situation in modern societies. Here, we report a laboratory experiment in which a total of 250 participants performed a “restless” two-armed bandit task either alone, or collectively in a centralized or decentralized network. Although both network conditions outperformed the solo condition, no sizable performance difference was detected between the centralized and decentralized networks. To understand the absence of network effects, we analyzed participants’ behavior parametrically using an individual choice model. We then conducted exhaustive agent-based simulations to examine how different choice strategies may underlie collective performance in centralized or decentralized networks under volatile or stationary task environments. We found that, compared to the stationary environment, the difference in network structure had a much weaker impact on collective performance under the volatile environment across broad parametric variations. These results suggest that structural impacts of networks on collective intelligence may be constrained by the degree of environmental volatility.

Insights Into Functional and Structural Impacts of nsSNPs in XPA-DNA Repairing Gene

Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation in people. SNPs are valuable resource for exploring the genetic basis of disease. The XPA gene provides a way to produce a protein used to repair damaged DNA. This study used the computational methods to classify SNPs and estimate their probability of being neutral or deleterious. The purpose of this analysis is to predict the effect of nsSNPs on the structure and function of XPA proteins. Data was collected from the NCBI hosted dbSNP. The authors examined the pathogenic effect of 194 nsSNPs in the XPA gene with computational tools. Four nsSNPs (C126S, C126W, R158S, and R227Q) those potentially effect on structure and function of the XPA protein were identified with combination of SIFT, PolyPhen, Provean, PHD-SNP, I-Mutant, ConSurf server and Project HOPE. This is the first comprehensive analysis in which XPA gene variants studied using in silico methods and this research able to gain further insight into XPA protein variants and function.

In silico Analysis of Nonsynonymous Genomic Variants within CCM2 Gene Reaffirm the Existence of Dual Cores within Typical PTB Domain

Purpose: The objective of this study is to validate the existence of dual cores within the typical phosphotyrosine binding (PTB) domain and to identify potentially damaging and pathogenic nonsynonymous coding single nuclear polymorphisms (nsSNPs) in the canonical PTB domain of the CCM2 gene that causes cerebral cavernous malformations (CCMs). Methods: The nsSNPs within the coding sequence for PTB domain of human CCM2 gene, retrieved from exclusive database search, were analyzed for their functional and structural impact using a series of bioinformatic tools. The effects of the mutations on tertiary structure of the PTB domain in human CCM2 protein were predicted to examine the effect of the nsSNPs on tertiary structure on PTB Cores. Results: Our mutation analysis, through alignment of protein structures between wildtype CCM2 and mutant, indicated that the structural impacts of pathogenic nsSNPs is biophysically limited to only the spatially adjacent substituted amino acid site with minimal structural influence on the adjacent core of the PTB domain, suggesting both cores are independently functional and essential for proper CCM2 function. Conclusion: Utilizing a combination of protein conservation and structure-based analysis, we analyzed the structural effects of inherited pathogenic mutations within the CCM2 PTB domain. Our results indicated that the pathogenic amino acid substitutions lead to only subtle changes locally confined to the surrounding tertiary structure of the PTB core within which it resides, while no structural disturbance to the neighboring PTB core was observed, reaffirming the presence of dual functional cores in the PTB domain.

Emerging chikungunya virus variants at the E1-E1 inter-glycoprotein spike interface impact virus attachment and Inflammation

Chikungunya virus (CHIKV) is a re-emerging arthropod-borne alphavirus and a serious threat to human health. Therefore, efforts toward elucidating how this virus causes disease and the molecular mechanisms underlying steps of the viral replication cycle are crucial. Using an in vivo transmission system that allows intra-host evolution, we identified an emerging CHIKV variant carrying a mutation in the E1 glycoprotein (V156A) in the serum of mice and saliva of mosquitoes. E1 V156A has since emerged in humans during an outbreak in Brazil, co-occurring with a second mutation, E1 K211T, suggesting an important role for these residues in CHIKV biology. Given the emergence of these variants, we hypothesized that they function to promote CHIKV infectivity and subsequent disease. Here, we show that E1 V156A and E1 K211T modulate virus attachment and fusion and impact binding to heparin, a homolog of heparan sulfate, a key entry factor on host cells. These variants also exhibit differential neutralization by anti-glycoprotein monoclonal antibodies, suggesting structural impacts on the particle that may be responsible for altered interactions at the host membrane. Finally, E1 V156A and E1 K211T exhibit increased titers in an adult arthritic mouse model and induce increased foot-swelling at the site of injection. Taken together, this work has revealed new roles for E1 where discrete regions of the glycoprotein are able to modulate cell attachment and swelling within the host.

A Comparative Analysis of Co-Production in Public Services

This study investigates current research trends in co-production studies and discusses conceptual approaches. The conceptual paper contains studies on co-production in the field of public administration. This study identifies significant gaps in the field of study by systematically examining 32 co-production research works. The study’s contributions include (1) defining two common characteristics of co-production, (2) classifying three forms of co-production by end-users, and (3) discovering that the aims and performance of co-production are more effective for service providers when the strategy is citizen-centric. Future research should (1) concentrate on the reasons for co-production failures or successes, (2) identify additional barriers to co-production in service production, (3) investigate influences on service providers as well as structural impacts on the co-production process, and (4) provide practical assessments of co-production research.

Experimental behavior of injected geopolymer grout using styrene-butadiene latex for the repair and strengthening of masonry walls

Unreinforced masonry buildings in the historic centers of the world have often been overlooked for centuries without any protection. These buildings demonstrate low resistance under external effects, especially against earthquakes. Earthquakes cause serious damage to the buildings and even the collapse of structures as a result of seismic stimulation from the impact of pounding with structural impacts. For this reason, it is of great importance to repair and strengthen damaged masonry structures. This study investigated the testing of masonry wall specimens produced from different kinds of masonry units with various types of mortar. Then, geopolymer grouts with high mechanical properties were produced by using alkali activation and industrial products. The experimental performance of strengthened masonry wall samples was determined using the optimum geopolymer grout in vertical compression tests. The behavior, failure mode, and crack pattern of the masonry wall samples were determined under loading systems. Experimental results demonstrate that the use of additive styrene-butadiene (SB) latex geopolymer grouts on damaged walls increased the load-carrying capacity and ductility significantly compared to the corresponding values of samples before initial failure. All of the strengthened walls failed through the de-bonding failure mode, and no visible damage was observed on the samples. Consequently, geopolymer grouts displayed many advantages over conventional repair materials due to their high viscosity, compressive strength, eco-friendliness, and excellent resistance.

Effect of natural mutations of SARS-CoV-2 on spike structure, conformation and antigenicity

New SARS-CoV-2 variants that have accumulated multiple mutations in the spike (S) glycoprotein enable increased transmission and resistance to neutralizing antibodies. Here, we study the antigenic and structural impacts of the S protein mutations from four variants, one that was involved in transmission between minks and humans, and three that rapidly spread in human populations and originated in the United Kingdom, Brazil or South Africa. All variants either retained or improved binding to the ACE2 receptor. The B.1.1.7 (UK) and B.1.1.28 (Brazil) spike variants showed reduced binding to neutralizing NTD and RBD antibodies, respectively, while the B.1.351 (SA) variant showed reduced binding to both NTD- and RBD-directed antibodies. Cryo-EM structural analyses revealed allosteric effects of the mutations on spike conformations and revealed mechanistic differences that either drive inter-species transmission or promotes viral escape from dominant neutralizing epitopes.