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Mesoionic imines: strong N-donors, electronic ambivalence and applications in catalysis
No full textMesoionic imines (MIIs) based on a 1,2,3-triazole core have been popularized in the past ca. 5 years. In this review article we discuss the synthesis, coordination ability and the structural and spectroscopic properties of this fascinating class of electronically ambivalent compounds. Apart from this, we also discuss the utility of MIIs and their compounds in directed C–H activation reactions, and in the activation and conversion of small molecules such as alkynes and CO2. Based on the current state of the art, we touch upon possible future developments of the chemistry of these classes of molecules
Is Homo Economicus Performative? Evidence From a Beauty Contest Experiment With Mainstream and Non-Mainstream Academic Economists
No full textDoes studying mainstream microeconomics cause individuals to behave more like the textbook version of homo economicus? Most studies suggesting a positive answer have used student samples and focused on self-interested behaviors in collective dilemma situations. In our study, we conducted an online “beauty contest” experiment with a sample of 1019 academic economists in Russia. The Russian case is of particular interest in this context, as the country's economic discipline is markedly divided between those who associate themselves with “Western” science—typically having received standard training in mainstream economics—and those who reject it in favor of a native intellectual tradition. The latter group usually openly denies the universal applicability of theories that describe economic life as an interaction between rational, self-interested agents. We leverage this division by examining variations in beauty contest game strategies within the group of academic economists rather than across disciplines, thereby reducing unobserved heterogeneity. We analyze whether those who embrace the international economic mainstream make choices closer to equilibrium compared to those who reject it and specifically describe homo economicus as an inadequate model of human behavior. The results show no statistical association: Economists who rely on theories assuming common knowledge of rationality did not expect more rational behavior from their colleagues
Exploring alternative Neolithization trajectories in Northeast China (Nen River Basin)
No full textUnderstanding the drivers of diversity and change in regional Neolithization trajectories has emerged as a major theme in World Prehistory with new insights appearing in many parts of the globe. In Northeast Asia, research on Neolithic transition over the past two decades has focused primarily on millet and rice domestication and their role in the rise of farming, social complexity, and early Chinese civilization. However, not all regions followed this agricultural trajectory. Instead, several areas exhibit “alternative” pathways to sedentism, storage-based economies, and emergent social diversification, but these remain underrepresented in international literature. In Northeast China, the Nen River basin, located north of the early farming communities of the Yellow and Liao River basins, is one such region. The Nen River drains into the Songhua River, one of the major tributaries of the Amur River, which drains into the Pacific Ocean. Importantly, the Nen River basin includes extensive wetlands and rich mosaic environments, which emerged during climatic shifts during the Pleistocene-Holocene transition. These aquatic ecosystems supported a transition to broad-spectrum foraging, which in turn led to sedentism and emergent social complexity without any evidence of plant domestication or substantial reliance on staple crops. These sites flourished culturally and demographically under the ameliorating conditions of the Holocene Climatic Optimum, but underwent a transition to nomadic pastoralism after the 4.2 ka cold and aridity event, with many distinctive local cultural traditions persisting. In this paper, we present an integrated synthesis of currently available archaeological and palaeo-environmental records from the Nen River basin. The aim is to reconstruct the cultural and social developments that arose from human-environmental interactions from the Late Pleistocene into the middle and late Holocene in this vital region of Northeast Asia. Our research indicates that Neolithization here occurred independently of agriculture, supported instead by aquatic and terrestrial resources. We further highlight the global potential for studying diverse “Neolithicities” across different world regions, and conclude with a series of themes and questions that require further research and cross-cultural synthesis
Photochemical Cu(iii)-mediated trifluoromethylation of (hetero)arenes and biomolecules
No full textA highly efficient and atom-economical method for the C–H trifluoromethylation of (hetero)arenes and complex biomolecules has been developed using a substoichiometric amount of the stable tetrakis(trifluoromethyl)cuprate(iii) salt. Upon violet-light irradiation in the presence of an oxidant, all four CF3 groups are sequentially converted into trifluoromethyl radicals, enabling high-yielding transformations under mild conditions. The protocol exhibits excellent functional group tolerance and is applicable to the late-stage trifluoromethylation of pharmaceuticals, amino acids, and nucleosides. Mechanistic studies support a photoinitiated radical pathway and reveal the full utilization of the Cu(iii) species. The results presented advance the use of copper-mediated strategies for the sustainable incorporation of fluorine into complex molecules
Unaffected polarization? Populism and affective polarization in comparative perspective
No full textWith both affective polarization and populism on the rise in several countries, many have proposed a link between the two phenomena. Yet, research offers little direct evidence on whether populist individuals are more polarized than their mainstream conunterparts. This paper aims to fill this gap by using data from 37 elections in 31 countries to provide a comparative account of the relationship between populism and affective polarization at the individual level. Contrary to common assumptions, resuts show no significant difference in affective polarization between more and less populist individuals. Instead, we identify a curvilinear relationship wherein both individauls who strongly endorse or reject populist ideas exhibit high levels of polarization, with substantial variations across countries. Furthermore, we find that populism is associated with a general disdain for all political parties rather than just rival parties. These findings challenge the prevailing assumption that populism is asymmetrically associated with affective polarization. We also provide evidence that ideological extremism, rather than populism, is more consistently and strongly associated with affective polarization in a large number of advanced democracies
GC-MS Analysis of Amphorae and Cooking Ware from Miletus (Western Asia Minor)
No full textTwo extractions protocols have been applied in order to extract lipids according to Pecci et al. 2013 (a), and other small organic acids according to Pecci et al. 2013a (b).
a. 2 g samples are extracted in 50 ml chloroform/methanol (2:1 v/v) for 2×15 min in an ultrasonic bath. The samples are then centrifuged for 10 min and the supernatant is concentrated down to approx. 1 ml. The residue is evaporated to dryness under a steady stream of nitrogen. The samples are saponified with 2 ml sodium hydroxide solution (2M in MeOH) for 1 h at 70° C. and after cooling, acidified with 15 drops of concentrated hydrochloric acid, the pH value is checked (pH 1). It is then extracted twice with 3 ml of chloroform; the solvent is removed under a constant stream of nitrogen and the sample is transferred to a vial with two times 50 μl of chloroform. The solvent is then evaporated off and the sample is derivatized with 25 μl of BSTFA at 70° C. for 1 hour. After the addition of 75 µl n-hexane and 5 µl internal standard (dotriacontane, see respective table of results for concentration)), the samples are analyzed by GC-MS.
b. 500 mg sample is extracted in 3 ml potassium hydroxide solution (1M in H2O) for 90 min at 70°C. The samples are then centrifuged for 10 min and the supernatant is acidified with 15 drops of concentrated hydrochloric acid, and the pH value (pH 1) is checked. Then the samples are shaken intensively with 3 ml ethyl acetate for 2 min and centrifuged for 10 min. This step is done 3 times. The supernatant is concentrated under a constant stream of nitrogen and transferred to a sample vial with two 50 μl portions of ethyl acetate. The solvent is then evaporated off and the sample is derivatized with 25 μl of BSTFA at 70° C. for 1 hour. After the addition of 75 µl n-hexane and 5 µl internal standard (dotriacontane, see respective table of results for concentration), the samples are analyzed by GC-MS.
The GC-MS analyses have been performed using an Agilent Technologies 5977E MSD with 7820A GC, with a 30 m HP-5 MS separation column (also Agilent Technologies).
Pecci et al. 2013 A. Pecci – M.A. Cau – N. Garnier, Identifying wine and oil pro-
duction: analysis of residues from Roman and Late Antique plastered vats, Journal of Archaeological Science 40, 4491–4498
Pecci et al. 2013a A. Pecci – G. Giorgi – L. Salvini – M.A. Cau Ontiveros, Identifying
Wine Markers in Ceramics and Plasters with Gas Chromatography-Mass Spectrometry. Experimental and Archaeological Materials, Journal of Archaeological Science 40, 109–115These tables contain the results of the organic residue analysis via GC-MS of 17 amphorae and 13 cooking vessels excavated in Miletus (Baths of Faustina and the so-called Bishoph’s Palace). They include the list of compounds confirmed by measurement of standard (after derivatisation with BSTFA, with GC-MS) and a first interpretation of their probable source.The tables list the analyzed samples according to their typology and sample ID-number
Listening to an Authoritarian Neighbor: Russian Propaganda on Chinese Social Media After the Ukraine Invasion
No full textAuthoritarian states actively engage in cross-border propaganda. While the effects and the narratives of this propaganda targeting democracies have been studied in the past, little attention has been paid to how sudden and significant geopolitical events influence the engagement of authoritarian propaganda in other like-minded states. This study closes the gap by looking at Russia’s propaganda in Chinese social media platform Weibo. We look at how users of the platform reacted to messages spread by Russia Today (RT) and Sputnik after the full-scale invasion against Ukraine. Applying computational text analysis and regression analysis we show that although the outbreak of the war led to a surge in Russian propaganda—especially anti-Western and war-related narratives—Chinese audiences exhibited a pronounced tendency to engage primarily with narratives highlighting non-Western cooperation, reflecting a strong alignment with the Chinese government’s domestic propaganda
Synthesis and structure-activity relationship study of novel quinazolin-4(3H)-one derivatives as Toll-like receptor 7 and 8 agonists with immunomodulatory activity
No full textToll-like receptors (TLRs) 7 and 8 are intracellular pattern recognition receptors that play a crucial role in the innate immune system, making them promising targets for the treatment of viral infections, autoimmune diseases and cancer. In this study, we present the synthesis and biological evaluation of quinazolin-4(3H)-one derivatives as a new class of dual TLR7/8 agonists. In a comprehensive structure-activity relationship (SAR) study, different substitutions on the quinazoline ring and modifications of the aliphatic side chain were investigated. Several compounds showed significantly improved potency compared to the original hit compound, with EC50 values in the nanomolar and low micromolar range for TLR7 and TLR8, respectively. The most potent compounds significantly increased the secretion of the proinflammatory cytokines TNF-α, IL-1β, IL-8 and interferon γ in peripheral blood mononuclear cells (PBMCs). In addition, increased secretion of TNF-α and upregulated CD86 expression in dendritic cells were also observed, indicating their immunomodulatory properties. Notably, the most potent compound 69 significantly suppressed tumor growth in vivo in the CT26 mouse tumor model after intratumoral administration. These results highlight the potential of quinazolinone-based compounds as promising candidates for further development of new immunomodulatory agents targeting TLR7 and TLR8
Mechanistic insights into recruitment and regulation of the RNA helicase UPF1 in replication-dependent histone mRNA decay
No full textMetazoan histone mRNAs are a unique class of mRNAs that lack the poly(A) tail present in all other eukaryotic transcripts. Instead, they end in a conserved stem-loop (SL) structure, necessitating a decay mechanism that is distinct from deadenylation-initiated degradation. Here, combining structural and functional approaches, we elucidate molecular mechanisms of initiation of histone mRNA decay. At the end of S-phase, the RNA helicase UPF1, the exoribonuclease 3’hExo and stem-loop binding protein SLBP all contribute to histone mRNA degradation, although how they are mechanistically coupled remained unknown. The cryoEM structure of an UPF1:SL RNA complex, presented here, shows that binding of UPF1 partially melts the RNA stem in the absence of ATP, harnessing the free energy derived from RNA-binding to unwind RNA. This melting event primes the SL-RNA for decay by 3’hExo. Using biochemical and cellular analyses, we demonstrate that SLBP directly engages the UPF1 helicase core to attenuate its unwinding activity and prevent premature degradation. Activation of UPF1 at a later stage promotes SL-RNA decay. We provide direct evidence that UPF1, SLBP and 3’hExo form a degradosome-like assembly that functionally couples SL unwinding and degradation, highlighting a dynamic and intricate network of UPF1-centric interactions that orchestrates timely histone mRNA decay
Answer set programming for pattern generation in logical analysis of data
No full textLogical Analysis of Data (LAD) is a powerful technique for data classification based on partially defined Boolean functions. The decision rules for class prediction in LAD are formed out of patterns. According to different preferences in the classification problem, various pattern types have been defined. The generation of these patterns plays a key role in the LAD methodology and represents a computationally hard problem. In this article, we introduce a new approach to pattern generation in LAD based on Answer Set Programming (ASP), which can be applied to all common LAD pattern types