Intramolecular Hydrogen Bonding Rigidifying Flexible Bridge for Solution- and Vacuum-Processed TSCT-TADF Emitters.

To realize strong donor-acceptor face-to-face stacking for efficient through-space charge transfer-type thermally activated delayed fluorescence, a conceptually new design strategy is proposed to couple flexible bridges with adequate rigidity via built-in intramolecular hydrogen bonds (IHBs). The resulting emitter ACE-CN has a planarized benzyl methyl ether bridge self-anchored by the C-H···O IHB and shows a high photoluminescence quantum efficiency of 93%. The solution- and vacuum-processed devices exhibited high external quantum efficiencies of 11.8% and 24.7%, respectively.

The Cultural Evolution of Games of Chance : A Historical Investigation of Chinese Gambling.

Chance-based gambling has been a recurrent cultural activity throughout history and across many diverse human societies. In this paper, I combine quantitative and qualitative data and present a cultural evolutionary framework to explain why the odds in games of chance in premodern China appeared "designed" to ensure a moderate yet favorable house advantage. This is especially intriguing since extensive research in the history of probability has shown that, prior to the development of probability theory, people had very limited understanding of the nature of random events and were generally disinclined to think mathematically about the frequency of their occurrence. I argue that games of chance in the context of gambling may have culturally evolved into their documented forms via a process of selective imitation and retention, and neither the customers nor the gambling houses understood the probability calculus involved in these games.

Risk Factors and Clinical Characterization of Cardiovascularand Cerebrovascular Events in Elderly Hemodialysis Patients.

INTRODUCTION: The purpose of this study was to assess the risk factors and clinical characteristics of cardiovascular and cerebrovascular events in elderly hemodialysis patients. METHODS: Elderly patients undergoing hemodialysis (HD) at Deqing County People's Hospital in Zhejiang, China, from May 2020 to May 2023 were enrolled in this study. They were divided into two groups depending on the occurrence of cardiovascular or cerebrovascular events: the case group and the control group. RESULTS: A total of 106 patients were enrolled in this study. Among them, 49 patients experienced cardiovascular or cerebrovascular events, resulting in an incidence rate of 46.23%. According to whether cardiovascular or cerebrovascular events occurred, 57 patients were assigned to the control group, and 49 patients were assigned to the case group. Comparing the basic information and clinical indicators of the two groups, significant differences were observed in patients with hypertensive nephropathy and diabetic nephropathy (P < .05). There were also significant differences in dialysis duration, smoking history, systolic and diastolic blood pressures, uric acid, blood glucose, total cholesterol (TC), lowdensity lipoprotein cholesterol (TG), C-reactive protein (CRP), and PTH (parathyroid hormone) levels and platelet-to-lymphocyte ratio (PLR), between the two groups (P < .05). Multivariate logistic regression analysis revealed that longer dialysis duration, higher systolic and diastolic blood pressures, elevated uric acid, TC, TG, LDL-C, PTH, and blood glucose levels, smoking history, elevated PLR, and CRP were independent risk factors for cardiovascular and cerebrovascular events. The ROC curve showed that these risk factors predicted cardiovascular and cerebrovascular events in patients. CONCLUSION: Patients with underlying diseases such as hypertensive or diabetic nephropathy are more likely to experience cardiovascular and cerebrovascular events. Longer dialysis duration, higher systolic and diastolic blood pressures, elevated uric acid, TC, TG, LDL-C, PTH and blood glucose levels, and boosted inflammatory reaction are risk factors for these events among elderly HD patients. The purpose of this study is to provide practical guidelines for clinical treatment. Comprehensive measures such as active intervention of risk factors, rational drug use and regular examination should be taken to improve the overall health level to the greatest extent for elderly patients with high-risk HD. DOI: 10.52547/ijkd.7877.

Blocking cGAS-STING pathway promotes post-stroke functional recovery in an extended treatment window via facilitating remyelination.

BACKGROUND: Ischemic stroke is a major cause of worldwide death and disability, with recombinant tissue plasminogen activator being the sole effective treatment, albeit with a limited treatment window. The cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) pathway is emerging as the major DNA-sensing pathway to invoke immune responses in neuroinflammatory disorders. METHODS: By performing a series of neurobehavioral assessments, electrophysiological analysis, high-throughput sequencing, and cell-based assays based on the transient middle cerebral artery occlusion (tMCAO) mouse stroke model, we examined the effects and underlying mechanisms of genetic and pharmacological inhibition of the cGAS-STING pathway on long-term post-stroke neurological functional outcomes. FINDINGS: Blocking the cGAS-STING pathway, even 3 days after tMCAO, significantly promoted functional recovery in terms of white matter structural and functional integrity as well as sensorimotor and cognitive functions. Mechanistically, the neuroprotective effects via inhibiting the cGAS-STING pathway were contributed not only by inflammation repression at the early stage of tMCAO but also by modifying the cell state of phagocytes to facilitate remyelination at the sub-acute phase. The activation of the cGAS-STING pathway significantly impeded post-stroke remyelination through restraining myelin debris uptake and degradation and hindering oligodendrocyte differentiation and maturation. CONCLUSIONS: Manipulating the cGAS-STING pathway has an extended treatment window in promoting long-term post-stroke functional recovery via facilitating remyelination in a mouse stroke model. Our results highlight the roles of the cGAS-STING pathway in aggregating stroke pathology and propose a new way for improving functional recovery after ischemic stroke. FUNDING: This work was primarily funded by the National Key R&D Program of China.

Potential drug targets for gastroesophageal reflux disease and Barrett's esophagus identified through Mendelian randomization analysis.

Gastroesophageal reflux disease (GERD) is a prevalent chronic ailment, and present therapeutic approaches are not always effective. This study aimed to find new drug targets for GERD and Barrett's esophagus (BE). We obtained genetic instruments for GERD, BE, and 2004 plasma proteins from recently published genome-wide association studies (GWAS), and Mendelian randomization (MR) was employed to explore potential drug targets. We further winnowed down MR-prioritized proteins through replication, reverse causality testing, colocalization analysis, phenotype scanning, and Phenome-wide MR. Furthermore, we constructed a protein-protein interaction network, unveiling potential associations among candidate proteins. Simultaneously, we acquired mRNA expression quantitative trait loci (eQTL) data from another GWAS encompassing four different tissues to identify additional drug targets. Meanwhile, we searched drug databases to evaluate these targets. Under Bonferroni correction (P < 4.8 × 10-5), we identified 11 plasma proteins significantly associated with GERD. Among these, 7 are protective proteins (MSP, GPX1, ERBB3, BT3A3, ANTR2, CCM2, and DECR2), while 4 are detrimental proteins (TMEM106B, DUSP13, C1-INH, and LINGO1). Ultimately, C1-INH and DECR2 successfully passed the screening process and exhibited similar directional causal effects on BE. Further analysis of eQTLs highlighted 4 potential drug targets, including EDEM3, PBX3, MEIS1-AS3, and NME7. The search of drug databases further supported our conclusions. Our study indicated that the plasma proteins C1-INH and DECR2, along with 4 genes (EDEM3, PBX3, MEIS1-AS3, and NME7), may represent potential drug targets for GERD and BE, warranting further investigation.

APC mutations disrupt ß-catenin destruction complex condensates organized by Axin phase separation.

The Wnt/ß-catenin pathway is critical to maintaining cell fate decisions. Recent study showed that liquid-liquid-phase separation (LLPS) of Axin organized the ß-catenin destruction complex condensates in a normal cellular state. Mutations inactivating the APC gene are found in approximately 80% of all human colorectal cancer (CRC). However, the molecular mechanism of the formation of ß-catenin destruction complex condensates organized by Axin phase separation and how APC mutations impact the condensates are still unclear. Here, we report that the ß-catenin destruction complex, which is constructed by Axin, was assembled condensates via a phase separation process in CRC cells. The key role of wild-type APC is to stabilize destruction complex condensates. Surprisingly, truncated APC did not affect the formation of condensates, and GSK 3ß and CK1α were unsuccessfully recruited, preventing ß-catenin phosphorylation and resulting in accumulation in the cytoplasm of CRCs. Besides, we propose that the phase separation ability of Axin participates in the nucleus translocation of ß-catenin and be incorporated and concentrated into transcriptional condensates, affecting the transcriptional activity of Wnt signaling pathway.

Structural and compositional diversity of biosurfactants produced by a novel strain of Sporosarcina luteola ME44 from oil reservoir.

The urealytically active microorganism Sporosarcina luteola induces the precipitation of metals, which has attracted attention in biomineralization, bioremediation, and industrial waste recycling. Herein, we report a novel biosurfactant-producing strain of S. luteola ME44 isolated from Chinese Oilfield. The structure, composition, and surface activity of the biosurfactants produced by S. luteola ME44 were investigated by using a combination of the high-performance liquid chromatography, time-of-flight mass spectrometry, and surface tensiometer. The biosurfactant extracted by strain ME44 was identified as surfactin with five variants and the yield was 1010 ± 60 mg⋅L-1 . This is the first report on the structural composition and surface activity of biosurfactants isolated from the S. luteola. It extended our knowledge about the role of the species S. luteola in the ecosystem of extreme natural environments such as oil reservoir. In addition, S. luteola ME44 showed bioprecipitation properties for metal ions Cd(II), Cu(II), Zn(II), and Ag(I), which indicated the application potential of S. luteola in the field of bioremediation.

STING signaling in islet macrophages impairs insulin secretion in obesity.

The innate immune regulator stimulator of interferon genes (STING) mediates self-DNA sensing and leads to the induction of type I interferons and inflammatory cytokines, which promotes the progression of various inflammatory and autoimmune diseases. Innate immune system plays a critical role in regulating obesity-induced islet dysfunction, whereas the potential effect of STING signaling is not fully understood. Here, we demonstrate that STING is mainly expressed and activated in islet macrophages upon high-fat diet (HFD) feeding. Sting-/- alleviates HFD-induced islet inflammation by inhibiting the expression of pro-inflammatory cytokines and the infiltration of macrophages. Mechanically, palmitic acid incubation promotes mitochondrial DNA leakage into the cytosol and subsequently activates STING pathway in macrophages. Additionally, STING activation in macrophages impairs glucose-stimulated insulin secretion by mediating the engulfment of ß cell insulin secretory granules. Pharmacologically inhibiting STING activation enhances insulin secretion to control hyperglycemia. Together, our results reveal a regulatory mechanism in controlling the islet inflammation and insulin secretion in diet--induced obesity and suggest that selective blocking of the STING activation may be a promising strategy for treating type 2 diabetes.

Molecular detection of Bartonella species in wild small mammals in western Yunnan Province, China.

Background: Small mammals serve as the main reservoir for Bartonella and as a proxy indicator of the potential risk of Bartonella transmission from nature to humans. They offer a valuable early warning for human infection. Nevertheless, geographical variations in the impact of the host on the occurrence of Bartonella infection are underestimated. This study was designed to investigate the infection characteristics of Bartonella and explore its species diversity in wild small mammals in western Yunnan Province, China. Methods: Wild small mammals were captured from Yulong, Jianchuan, and Lianghe counties in western Yunnan Province between 2015 and 2016. Real-time quantitative PCR (qPCR) was used to detect Bartonella infection, and the Bartonella species were identified by phylogenetic analysis. The factors associated with Bartonella infection in small mammals were analyzed by the Chi-square Test. Results: The prevalence of Bartonella in small mammals was 47.85% (768/1605). Lianghe County had the highest Bartonella infection rate, with 56.27% of the samples tested positive, followed by a rate of 50.91% was tested in Yulong County, and 39.97% in Jianchuan County (p < 0.001). Bartonella was detected positive in a total 25 small mammal species, with infection rates ranging from 2.17% to 100%. Niviventer fulvescens had the highest Bartonella infection rate. In comparison with the dominant small mammal species, Eothenomys mileyus had the lowest Bartonella infection rate than that in Apodemus chevrieri, Rattus tanezumi, and Apodemus draco (p < 0.001). Male small mammals had a higher infection rate than females (p < 0.05). The prevalence of Bartonella in small mammals during the summer season was higher compared to the other three seasons (p < 0.001). Woodland landscape had the highest Bartonella infection rate (p < 0.001). Bartonella rochalimae, B. japonica, B. tribocorum, B. washoensis, B. sylvatica, and B. rattimassiliensis were obtained from infected small mammals. Conclusion: This study showed a high prevalence of Bartonella was detected with various Bartonella species in small mammals in Yulong, Jianchuan, and Lianghe counties of western Yunnan Province. These findings hold significant scientific clues, providing valuable reference points for further research of Bartonella natural foci in Yunnan or other analogues environments.

The value of sociogenomics in understanding genetic evolution in contemporary human populations.

Burt's target article oddly misses the important intellectual contribution of sociogenomics to our understanding of genetic evolution in contemporary human populations. Although social scientists' immediate research agendas are often not evolutionary in nature, I call for a better appreciation of the role of sociogenomics in answering important evolutionary questions.

A new biosurfactant-producing strain, Fictibacillus nanhaiensis ME46, isolated from an oil field in China.

The genus Fictibacillus contains twelve species significant in the synthesis of cellulose-degrading enzymes and phenylalanine dehydrogenase, isolated mainly from marine sedimentary environments. Here, we report a new biosurfactant-producing strain, Fictibacillus nanhaiensis ME46, isolated from Daqing oil field in China. The biosurfactant extracted from Strain ME46 was determined as surfactin, one of the representative families of lipopeptide biosurfactants. The yield of the surfactin produced by strain ME46 was 0.62 g·L-1 as determined by high-performance liquid chromatography, and the critical micelle concentration (CMC) of the surfactin was estimated to be about 68 mg·L-1 and the surface tension at CMC was 35.1 mN·m-1. This study extended our knowledge about the role of the species Fictibacillus nanhaiensis in the ecosystem of natural environments such as the oil field.

Reyanning Mixture on Asymptomatic or Mild SARS-CoV-2 Infection in Children and Adolescents: A Randomized Controlled Trial.

OBJECTIVE: To assess the effect and safety of Reyanning Mixture (RYN) in treating asymptomatic or mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children and adolescents. METHODS: This is a prospective, open-label, randomized controlled trial. Patients aged 1-17 years and diagnosed with asymptomatic or mild coronavirus disease-2019 (COVID-19) were assigned to an intervention group (RYN plus standard care) and a control group (standard care) according to a randomization list. The primary outcomes were SARS-CoV-2 negative conversion time. Secondary outcomes included negative conversion rate on days 3 and 7, hospital length of stay, symptom relief rate, new-onset symptoms of asymptomatic infected patients, and progressive disease rate. The cycle threshold (Ct) values of ORF1ab or N genes were also tested. RESULTS: A total of 214 patients in the intervention group and 217 in the control group were analyzed. The SARS-CoV-2 negative conversion time was significantly shortened in the intervention group [5 days (interquartile range (IQR): 5-6) vs. 7 days (IQR: 6-7), P<0.01]. By days 3 and 7, the negative conversion rates were significantly higher in the intervention group (day 3: 32.7% vs. 21.2%, P=0.007; day 7: 75.2% vs. 60.8%, P=0.001). Ct values significantly increase on day 2 [ORF1ab gene: 35.62 (IQR: 29.17-45.00) vs. 34.22 (IQR: 28.41-39.41), P=0.03; N gene: 34.97 (IQR: 28.50-45.00) vs. 33.51 (IQR: 27.70-38.25), P=0.024] and day 3 [ORF1ab gene: 38.00 (IQR: 32.72-45.00) vs. 35.81 (IQR: 29.96-45.00), P=0.003; N gene: 37.16 (IQR: 32.01-45.00) vs. 35.26 (IQR: 29.09-45.00), P=0.01]. No significant difference was found in hospital length of stay between the two groups (P>0.05). Symptoms of cough were significantly improved (82.2% vs. 70.0%, P=0.02) and wheezing was significantly reduced (0.7% vs. 12.9%, P<0.01) in the intervention group compared with the control group. During the trial, no disease progression or serious adverse events were reported. CONCLUSION: Adding RYN to standard care may be a safe and effective treatment for children with asymptomatic and mild SARS-CoV-2 infection. (Registration No. ChiCTR2200060292).

Quantitative determination of rhamnolipid using HPLC-UV through carboxyl labeling.

Rhamnolipid, as a low-toxic, biodegradable and environmentally friendly biosurfactant, has broad application prospects in many industries. However, the quantitative determination of rhamnolipid is still a challenging task. Here, a new sensitive method for the quantitative analysis of rhamnolipid based on a simple derivatization reaction was developed. In this study, 3-[3'-(l-rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-C10-C10) and 3-[3'-(2'-O-α-l-rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-Rha-C10-C10) were utilized as the representative rhamnolipids. Liquid chromatography-mass spectrometry and high-performance liquid chromatography-ultra violet results showed that these two compounds were successfully labeled with 1 N1-(4-nitrophenyl)-1,2-ethylenediamine. There was an excellent linear relationship between rhamnolipid concentration and peak area of labeled rhamnolipid. The detection limits of the Rha-C10-C10 and Rha-Rha-C10-C10 were 0.018 mg/L (36 nmol/L) and 0.014 mg/L (22 nmol/L), respectively. The established amidation method was suitable for the accurate analysis of rhamnolipids in the biotechnological process. The method had good reproducibility with the relative standard deviation of 0.96% and 0.79%, respectively, and sufficient accuracy with a recovery of 96%-100%. This method was applied to quantitative analysis of 10 rhamnolipid homologs metabolized by Pseudomonas aeruginosa LJ-8. The single labeling method was used for the quantitative analysis of multiple components, which provided an effective method for the quality evaluation of other glycolipids with carboxyl groups.

Structural Diversity of the Lipopeptide Biosurfactant Produced by a Newly Isolated Strain, Geobacillus thermodenitrifcans ME63.

The genus Geobacillus is active in degradation of hydrocarbons in thermophilic and facultative environments since it was first reported in 1920. Here, we report a new strain, Geobacillus thermodenitrificans ME63, isolated from an oilfield with the ability of producing the biosurfactant. The composition, chemical structure, and surface activity of the biosurfactant produced by G. thermodenitrificans ME63 were investigated by using a combination of the high-performance liquid chromatography, time-of-flight ion mass spectrometry, and surface tensiometer. The biosurfactant produced by strain ME63 was identified as surfactin with six variants, which is one of the representative family of lipopeptide biosurfactants. The amino acid residue sequence in the peptide of this surfactin is N-Glu → Leu → Leu → Val → Leu → Asp → Leu-C. The critical micelle concentration (CMC) of the surfactin is 55 mg L-1, and the surface tension at CMC is 35.9 mN m-1, which is promising in bioremediation and oil recovery industries. The surface activity and emulsification properties of biosurfactants produced by G. thermodenitrificans ME63 showed excellent resistance to temperature changes, salinity changes, and pH changes.

The Evolution of Inclusive Folk-Biological Labels and the Cultural Maintenance of Meaning.

How is word meaning established, and how do individuals acquire it? What ensures the uniform understanding of word meaning in a linguistic community? In this paper I draw from cultural attraction theory and use folk biology as an example domain and address these questions by treating meaning acquisition as an inferential process. I show that significant variation exists in how individuals understand the meaning of inclusive biological labels such as "plant" and "animal" due to variation in their salience in contemporary ethnic minority groups in southwest China, and I present historical textual evidence that the meaning of inclusive terms is often unstable but can be sustained by such cultural institutions as religion and education, which provide situations in which the meaning of linguistic labels can be unambiguously inferred.

Adsorption Kinetics of Biosurfactant Surfactin at the n-Hexadecane/Aqueous Solution Interface.

Surfactin is a typical kind of biosurfactant with a large diversity of structure, and its molecular structure is expected to play a crucial role in its adsorption dynamics. Adsorption kinetics of surfactin homologues at the n-hexadecane/aqueous solution interface is studied using a droplet-based microfluidic method. Molecular dynamics simulations are performed to illustrate the dependence of adsorption energy on the surfactin structure. Rapid reduction of dynamic interfacial tensions is obtained. The best fit to experimental results reveals that surfactin with shorter aliphatic chains, C13-surfactin and C14-surfactin, has larger rate constants of adsorption and desorption. Interfacial tensions are rapidly reduced in the case of the oil/water interface which is freshly formed, and the equilibrium adsorption is rapidly established approximately in 100-350 ms at concentrations above the critical micelle concentration. C15-surfactin that has a longer aliphatic chain adsorbs and desorbs slower, and the equilibration time of adsorption is slightly longer. Moreover, C15-surfactin has a strong tendency for adsorbing at the interface, which is in accordance with the larger adsorption energy obtained by molecular dynamics simulation, and aggregating behavior in solution. The present study provides insights on the surfactin structure and the dynamics of adsorption at the liquid/liquid interface.

[Identifying Driving Factors and Their Interacting Effects on Sources of Heavy Metal in Farmland Soils with Geodetector and Multi-source Data].

The identification of heavy metal sources in farmland soils is essential for the rational health condition management and sustainable development of soil. Using source resolution results(source component spectrum and source contribution)of a positive matrix factorization(PMF)model, historical survey data, and time-series remote sensing data, integrating a geodetector(GD), an optimal parameters-based geographical detector(OPGD), a spatial association detector(SPADE), and an interactive detector for spatial associations(IDSA)model, this study explored the modifiable areal unit problem(MAUP) of spatial heterogeneity of soil heavy metal sources and identified the driving factors and their interacting effects on the spatial heterogeneity of soil heavy metal sources in categorical and continuous variables, respectively. The results showed that the spatial heterogeneity of soil heavy metal sources at small and medium scales was affected by the spatial scale, and the optional spatial unit was 0.08 km2 for detecting spatial heterogeneity of soil heavy metal sources in the study region. Considering spatial correlation and discretization level, the combination of the quantile method and discretization parameters with an interruption number of 10 could be implied to reduce the partitioning effects on continuous variables in the detection of spatial heterogeneity of soil heavy metal sources. Within categorical variables, strata(PD 0.12-0.48) controlled the spatial heterogeneity of soil heavy metal sources, the interaction between strata and watersheds explained 27.28%-60.61% of each source, and the high-risk areas of each source were distributed in the lower sinian system, upper cretaceous in strata, mining land in land use, and haplic acrisols in soil types. Within continuous variables, population (PSD 0.40-0.82) controlled the spatial variation in soil heavy metal sources, and the explanatory power of spatial combinations of continuous variables for each source ranged from 61.77% to 78.46%. The high-risk areas of each source were distributed in evapotranspiration (41.2-43 kg·m-2), distance from the river (315-398 m), enhanced vegetation index (0.796-0.995), and distance from the river (499-605 m). The results of this study provide a reference for the research of the drivers of heavy metal sources and their interactions in arable soils and provide an important scientific basis for the management of arable soil and its sustainable development in karst areas.

The Cultural Evolution of Medical Technologies : A Model of Sequential Treatments in the Medical Setting.

When people get ill, they naturally want to restore health through medical interventions. Here I model a situation in which individuals can psychologically entertain multiple potential treatments at once: when illness occurs, individuals would attempt one treatment first, and if it fails to produce an observable effect within a particular time period, a second treatment is attempted, and the eventual recovery is attributed to the treatment that is temporally closer. This creates population dynamics wherein the therapeutic power of the superior/effective medical treatments is misattributed to inferior/ineffective treatments. Through both analytic formulation and agent-based simulation, I show that the equilibrium frequencies of different treatment variants depend on their natural variability in the effect timing, the level of individual patience, and the number of cultural models sampled by the naive individual. Both ineffective and effective medical treatments may stably coexist in the population under a range of parameter settings.

Metavirome of 31 tick species provides a compendium of 1,801 RNA virus genomes.

The increasing prevalence and expanding distribution of tick-borne viruses globally have raised health concerns, but the full repertoire of the tick virome has not been assessed. We sequenced the meta-transcriptomes of 31 different tick species in the Ixodidae and Argasidae families from across mainland China, and identified 724 RNA viruses with distinctive virome compositions among genera. A total of 1,801 assembled and complete or nearly complete viral genomes revealed an extensive diversity of genome architectures of tick-associated viruses, highlighting ticks as a reservoir of RNA viruses. We examined the phylogenies of different virus families to investigate virome evolution and found that the most diverse tick-associated viruses are positive-strand RNA virus families that demonstrate more ancient divergence than other arboviruses. Tick-specific viruses are often associated with only a few tick species, whereas virus clades that can infect vertebrates are found in a wider range of tick species. We hypothesize that tick viruses can exhibit both 'specialist' and 'generalist' evolutionary trends. We hope that our virome dataset will enable much-needed research on vertebrate-pathogenic tick-associated viruses.

Combining Conformist and Payoff Bias in Cultural Evolution : An Integrated Model for Human Decision-Making.

Most research on transmission biases in cultural evolution has treated different biases as distinct strategies. Here I present a model that combines both frequency dependent bias (including conformist bias) and payoff bias in a single decision-making calculus and show that such an integrated learning strategy may be superior to relying on either bias alone. Natural selection may operate on humans' relative dependence on frequency and payoff information, but both are likely to contribute to the spread of variants with high payoffs. Importantly, the magnitude of conformist bias affects the evolutionary dynamics, and I show that an intermediate level of conformity may be most adaptive and may spontaneously evolve as it resists the invasion of low-payoff variants yet enables the fixation of high-payoff variants in the population.