SoK: Yield Aggregators in DeFi

Yield farming has been an immensely popular activity for cryptocurrency holders since the explosion of Decentralized Finance (DeFi) in the summer of 2020. In this Systematization of Knowledge (SoK), we study a general framework for yield farming strategies with empirical analysis. First, we summarize the fundamentals of yield farming by focusing on the protocols and tokens used by aggregators. We then examine the sources of yield and translate those into three example yield farming strategies, followed by the simulations of yield farming performance, based on these strategies. We further compare four major yield aggregators - Idle, Pickle, Harvest and Yearn - in the ecosystem, along with brief introductions of others. We systematize their strategies and revenue models, and conduct an empirical analysis with on-chain data from example vaults, to find a plausible connection between data anomalies and historical events. Finally, we discuss the benefits and risks of yield aggregators

SoK: Decentralized Exchanges (DEX) with Automated Market Maker (AMM) protocols

As an integral part of the Decentralized Finance (DeFi) ecosystem, Automated Market Maker (AMM) based Decentralized Exchanges (DEXs) have gained massive traction with the revived interest in blockchain and distributed ledger technology in general. Most prominently, the top six AMMs -- Uniswap, Balancer, Curve, Dodo, Bancor and Sushiswap -- hold in aggregate 15 billion USD worth of crypto-assets as of March 2021. Instead of matching the buy and sell sides, AMMs employ a peer-to-pool method and determine asset price algorithmically through a so-called conservation function. Compared to centralized exchanges, AMMs exhibit the apparent advantage of decentralization, automation and continuous liquidity. Nonetheless, AMMs typically feature drawbacks such as high slippage for traders and divergence loss for liquidity providers. In this work, we establish a general AMM framework describing the economics and formalizing the system's state-space representation. We employ our framework to systematically compare the mechanics of the top AMM protocols, deriving their slippage and divergence loss functions

No laughing matter : presence, consumption trends, drug awareness, and perceptions of "hippy crack" (nitrous oxide) among young adults in England

In clinical settings, nitrous oxide gas is a safe anesthetic used during childbirth, in dentistry, and to relieve anxiety in emergencies. Colloquially known as “hippy crack”’ or “laughing gas,” it is increasingly taken recreationally for its euphoric and relaxing effects and hallucinogenic properties. Using a self-reported survey, we gathered quantitative and qualitative information on users and non-users of hippy crack among a young population regarding: consumption patterns, knowledge, risk awareness and intentions toward future abuse. Quantitative responses from a total of 140 participants were analyzed for frequencies and relationships, whereas qualitative data were evaluated via identifying the reoccurring themes. Overall, 77.1% (n = 108) had heard of hippy crack and 27.9% (n = 39) admitted to past-year use. Prior users mostly indicated intended future use, had an average low number of past-year uses but some with > 20 occasions, had a varied number of inhalations per occasion (often 1–10) with an effect lasting up to 5 min, and a majority preferred social rather than lone use. For non-users, 79.2% said they would take hippy crack with the vast majority (94%) preferring a social setting. The results show a concerning gap between available evidence and awareness of side effects. Despite serious reported side effects, including psychosis and myeloneuropathy—especially on the young developing brain—only a minority (29.3%) was aware of any side effects. In contrast, in a hypothetical scenario depicting a first social encounter with hippy crack, the qualitative responses were in contrast to qualitative outcomes revealing that participants would try (n = 30)/not try (n = 25) it, would feel under pressure to try it (n = 6) with only 11 opting to exit the situation. In summary, this first report of trends and perceptions of the use of hippy crack among young adults in the England highlights a lack of concern with side effects, coupled to a willingness to partake. Because typical users are young with risks to the still developing brain, education about the nitrous oxide abuse is warranted to prevent impaired brain development. Further studies to investigate the possible effects of nitrous oxide on the developing brain in young adults would advance meaningful prevention

Hippocampal Sclerosis in Frontotemporal Dementia:When Vascular Pathology Meets Neurodegeneration

Hippocampal sclerosis (HS) is a common neuropathological finding and has been associated with advanced age, TDP-43 proteinopathy, and cerebrovascular pathology. We analyzed neuropathological data of an autopsy cohort of early-onset frontotemporal dementia patients. The study aimed to determine whether in this cohort HS was related to TDP-43 proteinopathy and whether additional factors could be identified. We examined the relationship between HS, proteinopathies in frontotemporal cortices and hippocampus, Alzheimer disease, cerebrovascular changes, and age. We confirmed a strong association between HS and hippocampal TDP-43, whereas there was a weaker association between HS and frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP). Nearly all of the FTLD-TDP cases had TDP-43 pathology in the hippocampus. HS was present in all FTLD-TDP type D cases, in 50% of the FTLD-TDP A cohort and in 6% of the FTLD-TDP B cohort. Our data also showed a significant association between HS and vascular changes. We reviewed the literature on HS and discuss possible pathophysiological mechanisms between TDP-43 pathology, cerebrovascular disease, and HS. Additionally, we introduced a quantitative neuronal cell count in CA1 to objectify the semiquantitative visual appreciation of HS.</p

Conception et synthèse d'inhibiteurs de métalloprotéases et de cibles à ligand acide

The objective of this work was to develop new chemical strategies for the synthesis of acidic compounds (carboxylic acids or bioisosters), also able to bind Zinc. This was part of a larger project aiming at screening two biological targets belonging to the family of Zinc-metalloproteases: aggrecanase-2 and angiotensin converting enzyme type 2.The chemical strategy used was solid phase synthesis on a trityle chloride resin. Precursors were grafted amino-acids protected by Fmoc- or ethylene-oxy-trimethyl silyl. Deprotection of such functions on resin allowed diversification of the amine function by acylation with a set of diverse carboxylic acids. We synthesized a library of 400 compounds, out of which a potential inhibitor of aggrecanase 2 was identified. Hit-optimization is currently underway.Tetrazole is a widely used acid bioisoster and also a zinc binding group. For these reasons, we also developed techniques for grafting tetrazoles on resin that allows new strategies for the synthesis of compounds bearing such function, exemplified by the first synthesis of irbesartan in solid support. A strategy in solution phase using micro-wave irradiation, was also developed for the synthesis of biphenyltetrazoles.To further extend our expertise in the synthesis of such series, we focused on biphenyl tetrazole derivatives bearing an amino-pyrazole group. We have developed Ullman reactions to diversify the core structure. The same work has enabled the development of a new reaction to para-iodophenyle-pyrazoles in one step, which opens the way to new retrosynthetic pathway to phenyl-pyrazoles. Out of the 20 compounds synthesized in these series, 5 displayed a promising micromolar IC50 on AT1 receptorL'objectif de ce travail était de développer de nouvelles voies d'obtention de produits acides potentiellement ligand du zinc dans le cadre d'un projet plus vaste mené au laboratoire sur deux cibles biologiques appartenant à la famille des métalloprotéases à zinc, l'aggrécanase et l'enzyme de conversion de l'angiotensine de type 2.La stratégie chimique utilisée a été la phase solide à l'aide d'une résine chlorure de trityle. La synthèse a été effectuée à partir de dérivés amino-acide protégés par un carbamate de fluorénylméthyle ou d'éthylène-oxy-triméthyle silicium permettant une déprotection en parallèle de la fonction amine une fois la fonction acide fixée à la résine. Nous avons obtenu une chimiothèque de 400 composés. A partir de ces 400 produits un hit a été identifié comme inhibiteur potentiel de l'aggrécanase 2. Des études de relations structures activités d'analogues de ce hit sont actuellement en cours.En parallèle, comme le tétrazole fait partie des fonctions chimiques potentiellement ligand du zinc et est une fonction phare dans le développement d'inhibiteurs du récepteur à l'angiotensine 2 (AT1), nous avons développé une nouvelle technique de greffage de tétrazole sur résine et de synthèse de chimiothèque biphényltétrazole.Ces travaux ont permis la mise au point d'une nouvelle méthode de synthèse de biphényltétrazole en phase homogène au micro-onde et la synthèse innovante de dérivés biphényltétrazole en phase solide exemplifié par la synthèse de l'irbésartan en phase solide.Nous avons ensuite développé des dérivés biphényltétrazole pyrazole. Pour cette famille de molécules, nous avons exploité les études effectuées sur la réaction de Buchwald que nous avons adaptée à nos composés. De plus ces mêmes travaux ont permis la mise au point d'une nouvelle réaction d'obtention de dérivés para-iodophényle pyrazole en une seule étape et qui ouvre une nouvelle voie rétrosynthétique de dérivés phényle pyrazole. Cinq de ces produits ont montré sur activité sur le récepteur AT1

Flaubert et Maupassant (l'esthétique du traumatisme, de la douleur à la création)

DUNKERQUE-BU Lettres Sci.Hum. (591832101) / SudocSudocFranceF

La fibromyalgie (caractéristiques, origines et traitements d une pathologie méconnue)

La fibromyalgie, syndrome polyalgique reconnu officiellement par l OMS depuis 1992, est une maladie complexe et très controversée. La douleur est le principal symptôme même si à celle-ci s ajoutent des troubles du sommeil, de l asthénie, et souvent un syndrome anxio-dépressif. La physiopathologie est encore mal connue avec plusieurs étiologies possibles telles que des anomalies du système nerveux central, des troubles musculaires mais aussi un possible rôle génétique et immunologique. Les traitements sont tout autant nombreux que les étiologies possibles, ils reposent sur des prises en charges médicamenteuses, éducatives, physiques et psychologiques pour améliorer en priorité la qualité de vie des patients et de réduire l incapacité fonctionnelle qui les touche.Fibromyalgia, a polyalgia syndrome recognized by the WHO since 1992, is a very much debated complex disease. Pain is the main symptom, but there are other symptoms like sleep disorders, asthenia and, often, depression and anxiety disorders. Its physiopathological characteristics are not well known yet; among them there are various possible aetiologies such as abnormalities of the central nervous system, muscular disorders, as well a probable genetic and immunological causes. There are many treatments as there are different aetiologies, these treatments consist of medicinal, physical and physiological care and advice and aim at improving, as a priority, the patients quality of life and reduce their functional disability.AMIENS-BU Santé (800212102) / SudocSudocFranceF

Bouwen aan een breed sociaal beleid : netwerken en regie

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