43 research outputs found
Viiteraamistik turvariskide haldamiseks plokiahela abil
Turvalise tarkvara loomiseks on olemas erinevad programmid (nt OWASP), ohumudelid (nt STRIDE), turvariskide juhtimise mudelid (nt ISSRM) ja eeskirjad (nt GDPR). Turvaohud aga arenevad pidevalt, sest traditsiooniline tehnoloogiline infrastruktuur ei rakenda turvameetmeid kavandatult. Blockchain näib leevendavat traditsiooniliste rakenduste turvaohte. Kuigi plokiahelapõhiseid rakendusi peetakse vähem haavatavateks, ei saanud need erinevate turvaohtude eest kaitsmise hõbekuuliks. Lisaks areneb plokiahela domeen pidevalt, pakkudes uusi tehnikaid ja sageli vahetatavaid disainikontseptsioone, mille tulemuseks on kontseptuaalne ebaselgus ja segadus turvaohtude tõhusal käsitlemisel. Üldiselt käsitleme traditsiooniliste rakenduste TJ-e probleemi, kasutades vastumeetmena plokiahelat ja plokiahelapõhiste rakenduste TJ-t. Alustuseks uurime, kuidas plokiahel leevendab traditsiooniliste rakenduste turvaohte, ja tulemuseks on plokiahelapõhine võrdlusmudel (PV), mis järgib TJ-e domeenimudelit. Järgmisena esitleme PV-it kontseptualiseerimisega alusontoloogiana kõrgema taseme võrdlusontoloogiat (ULRO). Pakume ULRO kahte eksemplari. Esimene eksemplar sisaldab Cordat, kui lubatud plokiahelat ja finantsjuhtumit. Teine eksemplar sisaldab lubadeta plokiahelate komponente ja tervishoiu juhtumit. Mõlemad ontoloogiaesitlused aitavad traditsiooniliste ja plokiahelapõhiste rakenduste TJ-es. Lisaks koostasime veebipõhise ontoloogia parsimise tööriista OwlParser. Kaastööde tulemusel loodi ontoloogiapõhine turberaamistik turvariskide haldamiseks plokiahela abil. Raamistik on dünaamiline, toetab TJ-e iteratiivset protsessi ja potentsiaalselt vähendab traditsiooniliste ja plokiahelapõhiste rakenduste turbeohte.Various programs (e.g., OWASP), threat models (e.g., STRIDE), security risk management models (e.g., ISSRM), and regulations (e.g., GDPR) exist to communicate and reduce the security threats to build secure software. However, security threats continuously evolve because the traditional technology infrastructure does not implement security measures by design. Blockchain is appearing to mitigate traditional applications’ security threats. Although blockchain-based applications are considered less vulnerable, they did not become the silver bullet for securing against different security threats. Moreover, the blockchain domain is constantly evolving, providing new techniques and often interchangeable design concepts, resulting in conceptual ambiguity and confusion in treating security threats effectively. Overall, we address the problem of traditional applications’ SRM using blockchain as a countermeasure and the SRM of blockchain-based applications. We start by surveying how blockchain mitigates the security threats of traditional applications, and the outcome is a blockchain-based reference model (BbRM) that adheres to the SRM domain model. Next, we present an upper-level reference ontology (ULRO) as a foundation ontology and provide two instantiations of the ULRO. The first instantiation includes Corda as a permissioned blockchain and the financial case. The second instantiation includes the permissionless blockchain components and the healthcare case. Both ontology representations help in the SRM of traditional and blockchain-based applications. Furthermore, we built a web-based ontology parsing tool, OwlParser. Contributions resulted in an ontology-based security reference framework for managing security risks using blockchain. The framework is dynamic, supports the iterative process of SRM, and potentially lessens the security threats of traditional and blockchain-based applications.https://www.ester.ee/record=b551352
Evaluation of a Legally Binding Smart-Contract Language for Blockchain Applications
Blockchain governs inter-organizational business processes and enables decentralized autonomous organizations (DAO) with governance capabilities via smart contracts (SC). Due to the programmer’s lack of prior knowledge of the contract domain, SCs are ambiguous and error-prone. Several works, i.e., SPESC, Symboleo, and SmaCoNat, exist to support the legally-binding SCs. The aforementioned SCLs present intriguing approaches to building legally-binding SCs but either lack domain completeness, or are intended for non-collaborative business processes. In our previous work, we address the above-mentioned shortcomings of the XML-based smart-legal-contract markup language (SLCML), in which blockchain developers focus on the contractual workflow rather than the syntax specifics. However, SLCML, as a blockchain-independent formal specification language, is not evaluated to determine its applicability, usefulness, and usability for establishing legally-binding SCs for workflow enactment services (WES) to automate and streamline the business processes within connected organizations. In accordance with this, we formally implement the SLCML and propose evaluation approaches, such as running case and lab experiments, to demonstrate the SLCML’s generality and applicability for developing legally-binding SCs. Overall, the results of this work ascertain the applicability, usefulness, and usability of the proposed SLCML for establishing legally-binding SCs for WES
Hilbert series of mixed braid monoid
Hilbert series is a simplest way to calculate the dimension and the degree of an algebraic variety by an explicit polynomial equation. The mixed braid group is a subgroup of the Artin braid group . In this paper we find the ambiguity-free presentation and the Hilbert series of canonical words of mixed braid monoid
Recombinant deoxyribonucleoside kinase from Drosophila melanogaster can improve gemcitabine based combined gene/chemotherapy for targeting cancer cells
A recombinant deoxyribonucleoside kinase from Drosophila melanogaster with a deletion of the last 20 amino acid residues (named DmdNKΔC20) was hypothesized as a potential therapeutic tool for gene therapy due to its broad substrate specificity and better catalytic efficiency towards nucleosides and nucleoside analogs. This study was designed to evaluate the effect of DmdNKΔC20 for sensitizing human cancer cell lines towards gemcitabine and to further investigate its role in reversal of acquired drug resistance in gemcitabine-resistant cancer cell line. The DmdNKΔC20 gene was delivered to three different cancer cell lines, including breast, colon and liver cancer cells, using lipid-mediated transfection reagent. After transfection, gene expression of DmdNKΔC20 was confirmed by reverse transcription quantitative PCR (qRT-PCR) and the combined effect of DmdNKΔC20 and gemcitabine based cytotoxicity was observed by cell viability assay. We further evolved a gemcitabine-resistant breast cancer cell line (named MCF7-R) through directed evolution in the laboratory, which showed 375-fold more resistance compared to parental MCF7 cells. Upon transfection with DmdNKΔC20 gene, MCF7-R cells showed 83-fold higher sensitivity to gemcitabine compared to the control group of MCF7-R cells. Moreover, we observed 79% higher expression of p21 protein in transfected MCF7-R cells, which may indicate induction of apoptosis. Our findings highlight the importance and therapeutic potential of DmdNKΔC20 in combined gene/chemotherapy approach to target a wide range of cancers, particularly gemcitabine-resistant cancers
Detection of BCR-ABL kinase domain mutations in CD34+ cells from newly diagnosed chronic phase CML patients and their association with imatinib resistance
BCR-ABL kinase domain (KD) mutations, the most common cause of imatinib resistance, are infrequently detected in newly diagnosed chronic-phase chronic myeloid leukemia (CP-CML) patients. Recent studies indicate pre-existing mutations (PEMs) can be detected in a higher percentage of CML patients using CD34+ stem/progenitor cells, and these mutations may correlate with imatinib resistance. We investigated KD mutations in CD34+ stem cells from 100 CP-CML patients by multiplex ASO-PCR and sequencing ASO-PCR products at the time of diagnosis. PEMs were detected in 32/100 patients and included F311L, M351T, and T315I. After a median follow-up of 30 months (range 8-48), all patients with PEMs exhibited imatinib resistance. Of 68 patients without PEMs, 24 developed imatinib resistance. Mutations were detected in 21 of these patients by ASO-PCR and KD sequencing. All 32 patients with PEMs had the same mutations. In imatinib-resistant patients without PEMs, we detected F311L, M351T, Y253F, and T315I mutations. All imatinib-resistant patients without T315I and Y253F mutations responded to imatinib dose escalation. In conclusion, BCR-ABL PEMs can be detected in a substantial number of CP-CML patients when investigated using CD34+ stem/progenitor cells. These mutations are associated with imatinib resistance, and mutation testing using CD34+ cells may facilitate improved, patient-tailored treatment
BlockNet Report: Exploring the Blockchain Skills Concept and Best Practice Use Cases
In order to explore the practical potential and needs of interdisciplinary
knowledge and competence requirements of Blockchain technology, the project
activity "Development of Interdisciplinary Blockchain Skills Concept" starts
with the literature review identifying the state of the art of Blockchain in
Supply Chain Management and Logistics, Business and Finance, as well as
Computer Science and IT-Security. The project activity further explores the
academic and industry landscape of existing initiatives in education which
offer Blockchain courses. Moreover, job descriptions and adverts are analyzed
in order to specify today's competence requirements from enterprises. To
discuss and define the future required competence, expert workshops are
organized to validate the findings by academic experts. Based on the research
outcome and validation, an interdisciplinary approach for Blockchain competence
is developed.
A second part focuses on the development of the Blockchain Best Practices
activity while conducting qualitative empirical research based on case studies
with industry representatives. Therefore, company interviews, based on the
theoretical basis of Output 1, explore existing Blockchain use cases in
different sectors. Due to the interdisciplinary importance of Blockchain
technology, these skills will be defined by different perspectives of
Blockchain from across multiple mentioned disciplines. The use cases and
companies for the interviews will be selected based on various sampling
criteria to gain results valid for a broad scale. The analysis of the various
use cases will be conducted and defined in a standardized format to identify
the key drivers and competence requirements for Blockchain technology
applications and their adoption. On the one hand, this approach ensures
comparability, on the other hand, it facilitates the development of a
structured and systematic framework.Comment: arXiv admin note: text overlap with arXiv:2102.0322
Antioxidant activities of aqueous extracts from nine different rose cultivars
Rose petals have been applied as food additives in teas, cakes and flavor extracts. The aim of this research study was to explore and reveal the antioxidant potential of aqueous extracts of rose petals belonging to nine genotypes of rose (wild as well as hybrid). The in vitro antioxidant activities of roses were studied by lipid peroxidation assay, DPPH radical scavenging assay, iron chelation assay, phosphomolybdenum reduction assay and total phenolic and flavonoid contents. The aqueous extract showed inhibition against lipid peroxidation (TBARS), induced by prooxidants (10 µM FeSO4) in mice liver homogenate. The free radical scavenging activities of the extracts were determined by scavenging of the DPPH radical. Extracts also showed metal chelating activities and high antioxidant activity in the phosphomolybdenum assay. The high content of phenolics and flavonoids detected in aqueous extracts may be responsible for the antioxidant activity. Amongst the different rose genotypes, screened, Rosa moschata (musk rose) was found to carry slightly higher antioxidant potential, owing to its higher phytochemical content