Spectrophotometric analysis of crown discoloration induced by MTA- and ZnOE-based sealers

Crown discoloration can be induced by root canal sealer remnants following root canal treatment. Objective: The aim of this study was to evaluate chromatic alterations in human tooth crowns induced by a Mineral Trioxide Aggregate-based sealer (MTA Fillapex®) and a commonly used ZnOE-based sealer (Roth-811). The tested null hypothesis was that the application of the materials did not induce clinically perceptible crown discoloration (Ho: CIE color difference Δ

Distributed Transactions using the SAGA pattern

Οι κατανεμημένες συναλλαγές αποτελούν κρίσιμο συστατικό των σύγχρονων κατανεμημένων συστημάτων, καθώς εξασφαλίζουν τη συνοχή και την ακεραιότητα των δεδομένων σε πολλαπλές βάσεις δεδομένων, διακομιστές ή υπηρεσίες. Είναι ιδιαίτερα σημαντικές στα σύγχρονα κατανεμημένα συστήματα, τα οποία είναι συχνά πολύπλοκα, δυναμικά με πολλά διασυνδεδεμένα στοιχεία, καθώς και σε συστήματα που περιλαμβάνουν ευαίσθητα ή κρίσιμα δεδομένα. Χωρίς κατανεμημένες συναλλαγές, θα ήταν δύσκολο να διασφαλιστεί ότι τα δεδομένα ενημερώνονται με συνέπεια και ορθότητα σε πολλαπλά συστήματα, γεγονός που θα μπορούσε να οδηγήσει σε ασυνέπειες και απώλεια δεδομένων. Ο στόχος μιας κατανεμημένης συναλλαγής είναι να διασφαλίσει ότι όλες οι λειτουργίες είτε όλες δεσμεύονται και τίθενται σε ισχύ είτε όλες ανακαλούνται και δεν έχουν κανένα αποτέλεσμα, ακόμη και σε περίπτωση αποτυχιών ή σφαλμάτων. Ωστόσο, οι παραδοσιακές προσεγγίσεις για την υλοποίηση κατανεμημένων συναλλαγών, όπως το Two-Phase Commit protocol (2PC), μπορεί να είναι πολύπλοκες και επιρρεπείς σε σφάλματα. Το πρότυπο SAGA είναι μια πολλά υποσχόμενη εναλλακτική προσέγγιση για την υλοποίηση κατανεμημένων συναλλαγών, καθώς επιτρέπει μεγαλύτερη ευελιξία και ανθεκτικότητα στα κατανεμημένα συστήματα. Σε ένα SAGA, κάθε βήμα αντιμετωπίζεται ως ξεχωριστή συναλλαγή, και εάν κάποιο βήμα αποτύχει, η διαδικασία ανατρέπεται σε μια προηγούμενη γνωστή καλή κατάσταση και ενεργοποιείται μια διαδικασία χειρισμού σφαλμάτων. Αυτό επιτρέπει τη μερική αποτυχία και τη δυνατότητα ανάκαμψης από αυτήν, καθιστώντας το πρότυπο SAGA ιδιαίτερα κατάλληλο για χρήση σε σύγχρονα κατανεμημένα συστήματα. Σε αυτή τη διπλωματική εργασία, θα διερευνήσουμε τη χρήση του προτύπου Saga για την υλοποίηση κατανεμημένων συναλλαγών σε κατανεμημένα συστήματα. Θα ξεκινήσουμε παρέχοντας μια επισκόπηση των κατανεμημένων συναλλαγών και των προκλήσεων που θέτουν στα σύγχρονα κατανεμημένα συστήματα. Στη συνέχεια θα παρουσιάσουμε το πρότυπο SAGA και θα συζητήσουμε τα οφέλη και τις προκλήσεις του. Αμέσως μετά, θα παρουσιάσουμε μια μελέτη περίπτωσης που υλοποιεί την «orchestrated» προσέγγισή μας - piSaga - για κατανεμημένες συναλλαγές σε Spring Boot microservices και θα πραγματοποιήσουμε ορισμένα πειράματα προκειμένου να μετρήσουμε την απόδοσή της σε σχέση με μια «choreographed» λύση. Τέλος, θα καταλήξουμε συνοψίζοντας τις βασικές ιδέες και τις συνεισφορές της ανάλυσής μας.Distributed transactions are a crucial component of modern distributed systems, as they ensure data consistency and integrity across multiple databases, servers, or services. They are essential in modern distributed systems, which are often complex and dynamic environments with many interconnected components, and in systems that involve sensitive or critical data. Without distributed transactions, ensuring that data is consistently and correctly updated across multiple systems would be challenging, which could lead to inconsistencies and data loss. The goal of a distributed transaction is to ensure that all operations either commit and take effect or roll back and have no effect, even in the case of failures or errors. However, traditional approaches to implementing distributed transactions, such as the Two-Phase commit (2PC) protocol, can be inflexible and prone to failure in complex and dynamic environments. The SAGA pattern is a promising alternative approach to implementing distributed transactions, as it allows for more flexibility and resilience in distributed systems. In a SAGA, each step in a long-running business process is treated as a separate transaction, and if any step fails, the process is rolled back to a previously known good state, and an error-handling process is triggered. This allows for partial failures and the ability to recover from them, making the SAGA pattern particularly well-suited for use in modern distributed systems. In this thesis, we will explore the use of the SAGA pattern for implementing distributed transactions in distributed systems. We will begin by providing an overview of distributed transactions and their challenges in modern distributed systems. We will then introduce the SAGA pattern and discuss its benefits and challenges. Next, we will present a case study that implements our orchestrated approach - piSaga - for distributed transactions in Spring Boot microservices. We will also conduct experiments to measure its performance against a choreographed solution. Finally, we will summarize the key insights and contributions of our analysis

Compound naming in Greek-speaking individuals with the agrammatic variant of Primary Progressive Aphasia

The paper reports findings obtained from a naming by definition task in two Greek-speaking individuals with the agrammatic variant of Primary Progressive Aphasia (PPA-G). One of the patients was at an early stage of the disease while the other was at a more advanced stage. The patient who was at a later stage produced a greater number of errors that differed significantly from healthy controls. This suggests that PPA-G affects compound naming albeit at a later stage. Qualitative error analysis highlights morphological impairment behind these difficulties in contrast to stroke induced aphasia

The Impact of the Local Government Institutional Framework on the Distribution of Intergovernmental Grants: Greek Republic as a Case Study

The article analyses grant allocation from central governments to municipalities in Greece during the period 2003-2010. A quantitative analysis is based on two simple models that include normative socioeconomic and institutional factors. Data of 970 municipalities and 50 prefectures of Greece over the period 2003-2010 clearly show that institutional variables such as years of general elections and prefect’s experience exert more influence on grant allocation than normative variables such as GDP per capita. A substantial transfer of competences from central to local government could significantly ameliorate local tax revenues

BUSCO: assessing genome assembly and annotation completeness with single-copy orthologs

Motivation: Genomics has revolutionized biological research, but quality assessment of the resulting assembled sequences is complicated and remains mostly limited to technical measures like N50. Results: We propose a measure for quantitative assessment of genome assembly and annotation completeness based on evolutionarily informed expectations of gene content. We implemented the assessment procedure in open-source software, with sets of Benchmarking Universal Single-Copy Orthologs, named BUSCO. Availability and implementation: Software implemented in Python and datasets available for download from http://busco.ezlab.org. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics onlin

New criteria for selecting the origin of DNA replication in Wolbachia and closely related bacteria

© 2007 Ioannidis et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in BMC Genomics 8 (2007): 182, doi:10.1186/1471-2164-8-182.Background: The annotated genomes of two closely related strains of the intracellular bacterium Wolbachia pipientis have been reported without the identifications of the putative origin of replication (ori). Identifying the ori of these bacteria and related alpha-Proteobacteria as well as their patterns of sequence evolution will aid studies of cell replication and cell density, as well as the potential genetic manipulation of these widespread intracellular bacteria. Results: Using features that have been previously experimentally verified in the alpha-Proteobacterium Caulobacter crescentus, the origin of DNA replication (ori) regions were identified in silico for Wolbachia strains and eleven other related bacteria belonging to Ehrlichia, Anaplasma, and Rickettsia genera. These features include DnaA-, CtrA- and IHF-binding sites as well as the flanking genes in C. crescentus. The Wolbachia ori boundary genes were found to be hemE and COG1253 protein (CBS domain protein). Comparisons of the putative ori region among related Wolbachia strains showed higher conservation of bases within binding sites. Conclusion: The sequences of the ori regions described here are only similar among closely related bacteria while fundamental characteristics like presence of DnaA and IHF binding sites as well as the boundary genes are more widely conserved. The relative paucity of CtrA binding sites in the ori regions, as well as the absence of key enzymes associated with DNA replication in the respective genomes, suggest that several of these obligate intracellular bacteria may have altered replication mechanisms. Based on these analyses, criteria are set forth for identifying the ori region in genome sequencing projects.PI, PS, SS, GT and KB acknowledge support of their work from intramural funding from the University of Ioannina. SB, JDH, LB and JW acknowledge support of their work from the U.S. National Science Foundation grant EF-0328363. SB also acknowledges the support from the NASA Astrobiology Institute (NNA04CC04A