On-Chain Smart Contract Verification over Tendermint

Smart contracts are computer code that runs in blockchain and expresses the rules of an agreement among parties. A bug in their code has major consequences, such as rule violations and security attacks. Smart contracts are immutable and cannot be easily replaced to patch a bug. To overcome these problems, there exist automatic static analyzers that find bugs before smart contracts are installed in blockchain. However, this off-chain verification is optional: programmers are not forced to use it. This paper defines on-chain verification instead, that occurs inside the same blockchain nodes, when the code of smart contracts is installed. It acts as a mandatory entry filter that bans code that does not abide to the verification rules, that are consequently part of the consensus rules of the blockchain. Thus, an improvement in on-chain verification entails a consensus update of the network. This paper provides an implementation of on-chain verification for smart contracts written in the Takamaka subset of Java, running as a Tendermint application. It shows that on-chain verification works, reporting actual experiments

I Caffè pedagogici in italia

ùThis paper offers a critical analysis of the experiences shared within a community of practitioners called Pedagogical Café. This is an informal network of pedagogues and educators who deal with educational themes through a methodology of comparison, exchange, and mutual enrichment. The purpose of meetings is to support and improve the skills of reflexive thinking and professional  awareness of educational practitioners

Delta Tocotrienol and Melatonin in Management of Mast Cell Canine Tumor

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Il tirocinio formativo per l’educatore socio-pedagogico: uno strumento di crescita professionale

The recent evolution of the Italian regulatory framework of the last two years has particularly concernedthe profiles of the socio-pedagogical professional educator and the pedagogue.The measures introduced between 2017 and 2018 indeed fulfilled the need, claimed by the academicand professional world, to reach a greater definition of curricular requirements, functionsand areas of intervention for both professions.The new configuration of the educational professions represents a challenge and requires processesof adaptation of training devices for internships in degree course in Educational Sciences. Withthis aim, a project research was undertaken on reorganization of the curricular internship for thedegree course in Educational Sciences, in the academic years 2016/2017 and 2017/2018, in orderto further enhance the theoretical-practical component of learning through a professionalizing intervention.The present contribution gives a general overview on the regulation of the internship in Italy andsecondly analyses the composite framework of preparatory training for field work of the sociopedagogicalprofessional educator. The second part of this article illustrates the experience gainedat the degree course in Educational Sciences of the University of Roma Tre and the operationalproposal experimented in the project, proposal hopefully useful to implement a concrete synergybetween university, professionals and the non-profit sector

Le associazioni professionali: ruolo, funzioni e utilità per i professionisti pedagogici

The legitimacy of the professional role of pedagogues and educators cannot be separated from their representation in the public institutions. In this scenario, the mandate of the professional associations is central. Law n. 4/2013 recognizes their function and postulates the faculty of individual associations to gather in aggregative forms on a voluntary basis. After the approval of Law 205/2017 art. 1 paragraphs 594-601, the profiles of pedagogue and social educator have assumed unique characteristics in the overview of the Italian professions, because they are regulated by a state law, but classified as professionals not belonging to a professional body. This peculiarity lends itself to create many misinterpretations and this contribution intends to clarify some aspects of the existing legislation, focusing on specific critical issues and formulating some proposals necessary for the relaunch of the pedagogical professions.La legittimità del ruolo professionale di pedagogisti ed educatori non può prescindere dalla loro rappresentanza nelle sedi istituzionali deputate a formulare politiche di indirizzo e di governo. In questo scenario il mandato delle associazioni professionali di categoria risulta essere centrale. La legge 4 del 2013 riconosce la loro funzione e postula la facoltà da parte delle singole associazioni di riunirsi in forme aggregative su base volontaria. Alla luce dell'approvazione della L. 205 del 2017 art. 1 commi 594-601, i profili di pedagogista ed educatore socio pedagogico hanno assunto caratteristiche uniche nel panorama delle professioni italiane, perché regolamentate da una legge dello Stato, ma disciplinate nell'alveo della classificazione delle cosiddette professioni non ordinistiche. Questa peculiarità si presta ad interpretazioni confusive ed il presente contributo intende fare chiarezza su alcuni aspetti della normativa oggi in vigore, soffermandosi su specifiche criticità esistenti e formulando alcune proposte necessarie per il rilancio delle professioni pedagogiche

ASSESSMENT OF KINETICS FOR BUTANOL PRODUCTION BY CLOSTRIDIUM ACETOBUTYLICUM

The economic scenario established at the beginning of the third millennium has revived the interest in Acetone-Butanol-Ethanol (ABE) fermentations. Recent developments in molecular techniques applied to solventogenic microrganisms in combination with recent advances in fermentation systems and downstream processing have contributed to improve ABE fermentation processes feasibility and competitiveness. The challenges raised over the last years as regards ABE production may be synthesized in: i) use of renewable resources as substrate; ii) selection of strains characterized by high ABE productivity; iii) development of new fermentation systems; iv) development of new downstream strategies for enhanced solvent recovery. The selection of unconventional substrates is favoured by the ability of clostridia strains to metabolize a wide range of carbohydrates like glucose, lactose, etc...., typically present in wastewater streams e.g. from food industries. Even though clostridia have been proven successful to produce ABE, information about kinetics of substrate conversion, cell growth and butanol production is still lacking. Studies available in literature most typically regard batch tests whose results do not apply easily to continuous processes. The strong interaction between the growth/acidogenesis phase and the solventogenesis phase should be taken into account. The reactor systems investigated for the ABE fermentation belong to the batch and fed-batch typologies. Some attempts are reported in literature regarding continuous fermentation by means of clostridia strains confined in the reactor by immobilization or cell-recycling. The present study reports the preliminary results of a research activity aiming at investigating the feasibility of the ABE production by Clostridium acetobutylicum ATCC824 in a continuous biofilm reactor adopting cheese whey as feedstock. The contribution regards the characterization of the kinetics related to the ABE production process by free C. acetobutylicum ATCC824 adopting as medium lactose solutions, in order to emulate the cheese whey. The conversion process is characterized in terms of cells, acids, solvents, pH, gas composition and total organic compounds as a function of time. Results are worked out to assess the kinetics of the cells growth and of the ABE production. The yields of the carbon source in cells, acids and solvents are also assessed. The investigation is carried out adopting both batch reactors and two continuous reactors. In particular, the continuous reactors are equipped to operate under controlled conversion regimes, acidogenesis or solventogenesis. Tests carried out under batch conditions show that: i) cells growth follows the Monod kinetics for lactose concentration (CL) smaller than 100 g/L; ii) the butanol specific production rate increases linearly with CL; iii) the lactose conversion - measured at the end of the solventogenesis phase - decreases with CL; iv) the selectivity of butanol with respect to total solvents increases with CL and stabilizes at about 72%W for CL larger than 30 g/L. Preliminary tests carried out with the continuous reactor operated under solventogenesis regime show that steady state establishes with respect to cells and metabolites concentration at dilution rate of about 0.04 h-1

Fungible and non-fungible tokens with snapshots in Java

Many blockchain applications exchange tokens, such as bitcoin and ether, or implement them through smart contracts. A trend in blockchain is to apply standards for token interoperability, unchanged, from platform to platform, easing the design challenges with trusted and widely-used specifications. However, the exploitation of the target language semantics can result in technological advantages and more efficient contracts. This paper presents a re-engineering of OpenZeppelin’s implementation of the ERC-20 and ERC-721 standards in Takamaka, a Java framework for programming smart contracts. It describes a sound solution to the issue about the types allowed for the token holders and a novel implementation for making snapshots of tokens, based on tree maps, that is possible in Java, but not in Solidity, more efficient than the literal translation in Java from Solidity, within the Java virtual machine. Moreover, it applies to ERC-721 as well, where a snapshot mechanism was previously missing. The same snapshot mechanism can also be applied beyond the smart contracts for tokens

Uso de Resíduos na Agricultura

This article presents a revision of the abstracts of The XX Brazilian Meeting of Fertility of the Soil and Nutrition of Plants, realizado in Piracicaba-São Paulo. The agronomic use of residues pressuposes a diverse number of applications such as their use in: animal feeding, substrate for fermentations, organic or organo-mineral fertilizer manufacture, soil coverages in different creations and substitutes of raw material for the agroindustrial or similar activities. However, the objective of this presentation is restricted to the aspects of the use of residues in the soil, understanding the aspects related to the characterization of these residues, the benefits or inconveniences of the application to the soil and the parameters that must be observed when the intention is to give this destination to the residues. In this way, this subject can be divided in two basic aspects: the residues and the soils. Concerning the residues, the main factors that affect their application to the soil are: chemical composition, physical characteristics, sanitary aspects, generated amount and regimen of release. In relation to soil, we must consider all those characteristics which are responsible for the capacity of the soil in deactivating and stabilizing the residues, through physical chemical and biological mechanisms. It is in this general framework that we intend to approach some specific aspects which are considered more important for the use of residues in soil.Este artigo apresenta uma revisão dos resumos da XX Reunião Brasileira de Fertilidade do Solo e Nutrição de Plantas, realizada em Piracicaba-São Paulo. A utilização agronômica de resíduos pressupõe um número bem diverso de aplicações, entre as quais se podem lembrar seu uso em alimentação animal, substrato para fermentações, fabricação de fertilizantes orgânicos ou organominerais, cobertura de pisos ("camas") em diferentes criações e sucedâneos de matéria-prima para as agroindústrias ou atividades assemelhadas. Entretanto, o objetivo desta apresentação é restrito aos aspectos do uso de resíduos no solo, compreendendo os aspectos relacionados à caracterização desses resíduos, os benefícios ou inconvenientes de sua aplicação no solo e os parâmetros que devem ser observados quando se pretende dar esse destino aos resíduos. Dessa maneira, o assunto a ser tratado pode ser dividido em dois aspectos fundamentais: os resíduos e os solos. No tocante aos resíduos, os principais fatores que afetam sua aplicação no solo são: composição química, características físicas, aspectos sanitários, quantidade gerada e regime de liberação. Já em relação ao solo, devem-se considerar prioritariamente todas aquelas características responsáveis pela capacidade do solo em desativar e estabilizar os resíduos, por meio de mecanismos físicos, químicos e biológicos. É dentro desse quadro geral que se pretende abordar alguns aspectos específicos e considerados mais importantes para a utilização dos resíduos no solo

Information Flow Analysis for Detecting Non-Determinism in Blockchain

A mandatory feature for blockchain software, such as smart contracts and decentralized applications, is determinism. In fact, non-deterministic behaviors do not allow blockchain nodes to reach one common consensual state or a deterministic response, which causes the blockchain to be forked, stopped, or to deny services. While domain-specific languages are deterministic by design, general purpose languages widely used for the development of smart contracts such as Go, provide many sources of non-determinism. However, not all non-deterministic behaviours are critical. In fact, only those that affect the state or the response of the blockchain can cause problems, as other uses (for example, logging) are only observable by the node that executes the application and not by others. Therefore, some frameworks for blockchains, such as Hyperledger Fabric or Cosmos SDK, do not prohibit the use of non-deterministic constructs but leave the programmer the burden of ensuring that the blockchain application is deterministic. In this paper, we present a flow-based approach to detect non-deterministic vulnerabilities which could compromise the blockchain. The analysis is implemented in GoLiSA, a semantics-based static analyzer for Go applications. Our experimental results show that GoLiSA is able to detect all vulnerabilities related to non-determinism on a significant set of applications, with better results than other open-source analyzers for blockchain software written in Go

Information Flow Analysis for Detecting Non-Determinism in Blockchain (Artifact)

A mandatory feature for blockchain software, such as smart contracts and decentralized applications, is determinism. In fact, non-deterministic behaviors do not allow blockchain nodes to reach one common consensual state or a deterministic response, which causes the blockchain to be forked, stopped, or to deny services. While domain-specific languages are deterministic by design, general-purpose languages widely used for the development of smart contracts such as Go, provide many sources of non-determinism. However, not all non-deterministic behaviours are critical. In fact, only those that affect the state or the response of the blockchain can cause problems, as other uses (for example, logging) are only observable by the node that executes the application and not by others. Therefore, some frameworks for blockchains, such as Hyperledger Fabric or Cosmos SDK, do not prohibit the use of non-deterministic constructs but leave the programmer the burden of ensuring that the blockchain application is deterministic. In this paper, we present a flow-based approach to detect non-deterministic vulnerabilities which could compromise the blockchain. The analysis is implemented in GoLiSA, a semantics-based static analyzer for Go applications. Our experimental results show that GoLiSA is able to detect all vulnerabilities related to non-determinism on a significant set of applications, with better results than other open-source analyzers for blockchain software written in Go