2,086 research outputs found
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Sustainability in a multi-level cultural evolutionary framework
National Socio-Environmental Synthesis Center, NSF DBI-1052875; John Templeton Foundation grant to ASU Institute of Human Origin
Information Synergy Maximizes the Growth Rate of Heterogeneous Groups
Collective action and group formation are fundamental behaviors among both
organisms cooperating to maximize their fitness, and people forming
socioeconomic organizations. Researchers have extensively explored social
interaction structures via game theory and homophilic linkages, such as in kin
selection and scalar stress, to understand emergent cooperation in complex
systems. However, we still lack a general theory capable of predicting how
agents benefit from heterogeneous preferences, joint information, or skill
complementarities in statistical environments. Here, we derive a general
statistical dynamics for the origin of cooperation based on the management of
resources and pooled information. Specifically, we show how groups that
optimally combine complementary agent knowledge about resources in statistical
environments maximize their growth rate. We show that these advantages are
quantified by the information synergy embedded in the conditional probability
of environmental states given agents' signals, such that groups with greater
diversity of signals maximize their collective information. It follows that,
when there are constraints placed on group formation, agents must intelligently
select with who they cooperate with to maximize the synergy available to their
own signal. Our results show how the general properties of information underlie
the optimal collective formation and dynamics of groups of heterogeneous agents
across social and biological phenomena.Comment: 14 pages, 4 figure
Whole blood lactate kinetics in patients undergoing quantitative resuscitation for septic shock
Introduction We sought to compare the association of whole blood lactate kinetics with survival in patients with septic shock undergoing early quantitative resuscitation. Methods Preplanned analysis of a multicenter emergency department (ED)-based randomized control trial of early sepsis resuscitation targeting three physiological variables: central venous pressure, mean arterial pressure, and either central venous oxygen saturation or lactate clearance. Inclusion criteria: suspected infection, two or more systemic inflammatory response syndrome criteria, and either SBP 4 mmol/l. All patients had a lactate measured initially and subsequently at two hours. Normalization of lactate was defined as a lactate decline to 2.0 mmol/l was seen in 187/272 (69%), and 68/187 (36%) patients normalized their lactate. Overall mortality was 19.7%. AUCs for initial lactate, relative lactate clearance, and absolute lactate clearance were 0.70, 0.69, and 0.58, respectively. Lactate normalization best predicted survival (OR = 6.1, 95% CI = 2.2 to 21), followed by lactate clearance of 50% (OR = 4.3, 95% CI = 1.8 to 10.3), initial lactate of <2 mmol/l (OR = 3.4, 95% CI = 1.5 to 7.8), and initial lactate <4 mmol/l (OR = 2.3, 95% CI = 1.3 to 4.3), with lactate clearance of 10% not reaching significance (OR = 2.3, 95% CI = 0.96 to 5.6).
Conclusions In ED sepsis patients undergoing early quantitative resuscitation, normalization of serum lactate during resuscitation was more strongly associated with survival than any absolute value or absolute/ relative change in lactate. Further studies should address whether strategies targeting lactate normalization leads to improved outcomes
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Efficient System Design and Sustainable Finance for China's Village Electrification Program: Preprint
This paper describes a joint effort of the Institute for Electrical Engineering of the Chinese Academy of Sciences (IEE), and the U.S. National Renewable Energy Laboratory (NREL) to support China's rural electrification program. This project developed a design tool that provides guidelines both for off-grid renewable energy system designs and for cost-based tariff and finance schemes to support them. This tool was developed to capitalize on lessons learned from the Township Electrification Program that preceded the Village Electrification Program. We describe the methods used to develop the analysis, some indicative results, and the planned use of the tool in the Village Electrification Program
Understanding cumulative cultural evolution
This is the final version of the article. Available from the publisher via the DOI in this record.No abstract availabl
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Bayaka adolescent boys nominate accessible adult men as preferred spear hunting = models les adolescents bayaka nomment les hommes adultes qui leurs sont accessibles comme modĂšles prĂ©fĂ©rĂ©s pour lâapprentissage de la chasse Ă la lance
Data availability: data are available on request. The code used in the analysis can be found online at https://www.journals.uchicago.edu/doi/suppl/10.1086/716853/suppl_file/303893code.zip .Online enhancements: appendix, R code.Humans are selective social learners. In a cultural landscape with many potential models, learners must balance the cost associated with learning from successful models with learning from accessible ones. Using structured interviews, we investigate the model selection biases of Congolese BaYaka adolescent boys learning to hunt with spears (n = 24; mean age [mage] = 15.79 years; range, 12â20 years). Results from social relations models suggest that adolescents nominated accessible adult men (closely related kin and neighbors) as preferred spear hunting models. Direct cues for success were not strong predictors for adolescent nomination in the statistical models, despite learners justifying model selection according to teaching and spear hunting skill. Indirect cues including body mass index, age, and cross-domain prestige were weak predictors for adolescent nomination. We interpret these findings as suggesting that BaYaka spear hunting knowledge is widely shared in the community, with all adult men participating in spear hunting and therefore having the requisite experience to transmit this skill. This supports previous findings that in egalitarian societies with low rates of role specialization, prestige has limited importance for cross-domain learning.
Les ĂȘtres humains sont des apprenants sociaux sĂ©lectifs. Dans un paysage culturel comportant de nombreux modĂšles potentiels, les apprenants doivent trouver un Ă©quilibre entre le coĂ»t associĂ© Ă lâapprentissage Ă partir de modĂšles qui ont fait leurs preuves et celui Ă partir de modĂšles accessibles. Ă lâaide dâentretiens structurĂ©s, nous Ă©tudions les biais de sĂ©lection de modĂšles des adolescents congolais BaYaka qui apprennent Ă chasser Ă la lance (n = 24, Ăąge moyen = 15,79 ans, intervalle: 12â20 ans). Les rĂ©sultats des modĂšles de relations sociales suggĂšrent que les adolescents dĂ©signent des hommes adultes accessibles (parents proches et voisins) comme modĂšles prĂ©fĂ©rĂ©s de chasse Ă la lance. Les indices directs de rĂ©ussite ne constituaient pas des prĂ©dicteurs forts de nomination par des adolescents dans les modĂšles statistiques, bien que les apprenants justifiaient la sĂ©lection du modĂšle en fonction des habiletĂ©s dâenseignement et de la chasse Ă la lance. Les indices indirects, dont lâindice de masse corporelle, lâĂąge et le prestige inter-domaines, constituaient de faibles prĂ©dicteurs de la nomination par les adolescents. Ces rĂ©sultats suggĂšrent que la connaissance de la chasse Ă la lance des BaYaka est largement partagĂ©e dans la communautĂ©, puisque tous les hommes adultes participent Ă la chasse Ă la lance et ont donc lâexpĂ©rience requise pour transmettre cette compĂ©tence. Ceci confirme les rĂ©sultats de recherches antĂ©rieures selon lesquels dans les sociĂ©tĂ©s Ă©galitaires, qui ont de faibles niveaux de spĂ©cialisation des rĂŽles, le prestige a une importance limitĂ©e dans lâapprentissage inter-domaines.Funding for this research was provided by awards from the Wenner-Gren Foundation (no. 9789) and the Leakey Foundation to S. Lew-Levy and A. Milks. Research was also supported by a Social Sciences and Humanities Research Council of Canada Postdoctoral Fellowship (no. 756-2019-0102) to S. Lew-Levy
Out of the empirical box: A mixed-methods study of tool innovation among Congolese BaYaka forager and Bondongo fisherâfarmer children
© 2021 The Authors. Tool innovation has played a crucial role in human adaptation. Yet, this capacity seems to arise late in development. Before 8 years of age, many children struggle to solve the hook task, a common measure of tool innovation that requires modification of a straight pipe cleaner into a hook to extract a prize. Whether these findings are generalizable beyond postindustrialized Western children remains unclear. In many small-scale subsistence societies, children engage in daily tool use and modification, experiences that theoretically could enhance innovative capabilities. Although two previous studies found no differences in innovative ability between children from Western and small-scale subsistence societies, these did not account for the latterâs inexperience with pipe cleaners. Thus, the current study investigated how familiarity with pipe cleaners affected hook task success in 132 Congolese BaYaka foragers (57 girls) and 59 Bondongo fisherâfarmers (23 girls) aged 4â12 years. We contextualized these findings within childrenâs interview responses and naturalistic observations of how pipe cleaners were incorporated into daily activities. Counter to our expectation, prior exposure did not improve childrenâs performance during the hook task. Bondongo children innovated significantly more hooks than BaYaka children, possibly because they participate in hook-and-line fishing. Observations and interviews showed that children imagined and innovated novel uses for pipe cleaners outside the experimental context, including headbands, bracelets, and suspenders. We relate our findings to ongoing debates regarding systematic versus unsystematic tool innovation, the importance of prior experience for the ontogeny of tool innovation, and the external validity of experimental paradigms
Outcome of Contemporary Percutaneous Coronary Intervention in the Elderly and the Very Elderly: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium
Background: There is a paucity of data on the outcome of contemporary percutaneous coronary intervention (PCI) in the elderly. Accordingly, we assessed the impact of age on outcome of a large cohort of patients undergoing PCI in a regional collaborative registry. Hypothesis: Increasing age is associated with a higher incidence of proceduralârelated complications. Methods: We evaluated the outcome of 152373 patients who underwent PCI from 2003 to 2008 in the 31 hospitals participating in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium. The procedural outcomes of the cohort were compared by dividing patients into <70 years of age, 70 to 79 years, 80 to 84 years, 85 to 89 years, and â„90 years. Results: Of the cohort, 64.64% were <70 years of age, 23.83% were 70 to 79 years, 7.85% were 80 to 84 years, 3.09% were 85 to 89 years, and 0.58% were 90 years or older. Increasing age was associated with an increase in allâcause inâhospital mortality, contrastâinduced nephropathy, transfusion, stroke/transient ischemic attack, and vascular complications. The overall inâhospital mortality rate was 1.09% and increased from 0.67% in those younger than 70 years up to 5.44% in those 90 years old or greater. The mortality rate in patients over 80 years approached 12% to 15% for those with STâsegment myocardial infarction and 39% in cardiogenic shock patients. Conclusions: The proportion of elderly patients referred for PCI is increasing. Procedural complications increase with age, and patients presenting with unstable symptoms are at the highest risk. © 2011 Wiley Periodicals, Inc. This work was supported by Blue Cross Blue Shield of Michigan. The authors have no other funding, financial relationships, or conflicts of interest to disclose.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86865/1/20926_ftp.pd
Gender-dependent differences in plasma matrix metalloproteinase-8 elevated in pulmonary tuberculosis.
Tuberculosis (TB) remains a global health pandemic and greater understanding of underlying pathogenesis is required to develop novel therapeutic and diagnostic approaches. Matrix metalloproteinases (MMPs) are emerging as key effectors of tissue destruction in TB but have not been comprehensively studied in plasma, nor have gender differences been investigated. We measured the plasma concentrations of MMPs in a carefully characterised, prospectively recruited clinical cohort of 380 individuals. The collagenases, MMP-1 and MMP-8, were elevated in plasma of patients with pulmonary TB relative to healthy controls, and MMP-7 (matrilysin) and MMP-9 (gelatinase B) were also increased. MMP-8 was TB-specific (p<0.001), not being elevated in symptomatic controls (symptoms suspicious of TB but active disease excluded). Plasma MMP-8 concentrations inversely correlated with body mass index. Plasma MMP-8 concentration was 1.51-fold higher in males than females with TB (p<0.05) and this difference was not due to greater disease severity in men. Gender-specific analysis of MMPs demonstrated consistent increase in MMP-1 and -8 in TB, but MMP-8 was a better discriminator for TB in men. Plasma collagenases are elevated in pulmonary TB and differ between men and women. Gender must be considered in investigation of TB immunopathology and development of novel diagnostic markers
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