On the Nature and Types of Anomalies: A Review

Anomalies are occurrences in a dataset that are in some way unusual and do not fit the general patterns. The concept of the anomaly is generally ill-defined and perceived as vague and domain-dependent. Moreover, despite some 250 years of publications on the topic, no comprehensive and concrete overviews of the different types of anomalies have hitherto been published. By means of an extensive literature review this study therefore offers the first theoretically principled and domain-independent typology of data anomalies, and presents a full overview of anomaly types and subtypes. To concretely define the concept of the anomaly and its different manifestations, the typology employs five dimensions: data type, cardinality of relationship, anomaly level, data structure and data distribution. These fundamental and data-centric dimensions naturally yield 3 broad groups, 9 basic types and 61 subtypes of anomalies. The typology facilitates the evaluation of the functional capabilities of anomaly detection algorithms, contributes to explainable data science, and provides insights into relevant topics such as local versus global anomalies.Comment: 38 pages (30 pages content), 10 figures, 3 tables. Preprint; review comments will be appreciated. Improvements in version 2: Explicit mention of fifth anomaly dimension; Added section on explainable anomaly detection; Added section on variations on the anomaly concept; Various minor additions and improvement

Systems biochemistry of macromolecular interactions involved in the regulation of the division ring stability in bacteria

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, leída el 14-12-2022En Escherichia coli la división se encuentra mediada por el divisoma, un anillo contráctil consistente en un complejo multiproteico posicionado con gran precisión en el centro de la célula (correspondiente al punto medio del eje largo de este bacilo) hacia el final del ciclo celular. El primer paso en la formación de esta maquinaria de división es el ensamblaje del denominado anillo Z, una estructura macromolecular dinámica que implica la polimerización de la proteína conservada FtsZ y que actúa como plataforma sobre la que se incorporan el resto de proteínas de división. El correcto posicionamiento espacial y temporal del anillo Z es crítico para la generación de células hijas viables, dado que desviaciones en la adecuada localización del mismo pueden conllevar consecuencias catastróficas para la bacteria como la bisección del cromosoma o la generación de células anucleadas. Por este motivo, E. coli cuenta con mecanismos de posicionamiento que aseguran la formación del anillo en el centro celular, de entre los cuales el sistema Min y el sistema de oclusión por nucleoide son los más estudiados. El sistema Min establece un patrón de oscilaciones que impide la formación del anillo en los polos celulares a la vez que permite su ensamblaje en el centro de la célula. Por su parte, el sistema de oclusión por nucleoide inhibe la formación del anillo Z en las proximidades del cromosoma bacteriano a través de la interacción directa de la proteína SlmA, unida a secuencias específicas de ADN (SBS) en el cromosoma, con FtsZ. Además, la acción conjunta de estos dos mecanismos reguladores negativos está complementada por el anclaje Ter, consistente en una red multiproteica en la que participan las proteínas ZapA, ZapB y la proteína de unión a ADN MatP que refuerza la formación del anillo Z en posiciones centrales...Escherichia coli cell division is mediated by the divisome, a contractile ring consisting of a multiprotein complex that accurately assembles at midcell (corresponding to the long axis midpoint of this bacillus) toward the end of the cell cycle. The first step in the formation of this division machinery is the assembly of the so-called Z-ring, a dynamic macromolecular structure involving the polymerization of the conserved protein FtsZ that serves as a scaffold for the recruitment of the rest of division proteins. Correct spatiotemporal assembly of theZ-ring is critical for the generation of viable daughter cells, since deviations in its positioning might result in catastrophic outcomes such as chromosome bisection or generation of anucleate cells. For this reason, E. coli relies on dedicated positioning mechanisms to ensure proper formation of the Z-ring at midcell, being the canonical ones the Min system and nucleoid occlusion, which act by blocking the assembly of the Z-ring at undesired locations. The Min system establishes an oscillation pattern that prevents Z-ring formation at the cell poles while allowing its assembly in the cell center. For its part, nucleoid occlusion inhibits Z-ring assembly in the vicinity of the chromosome through direct interaction of the Slm Aprotein, bound to specific DNA sequences (SBS) in the chromosome, with FtsZ.Besides, the concerted action of these two negative regulatory mechanisms is complemented by the Ter linkage, a protein network comprising ZapA, ZapB and the DNA-binding protein MatP that reinforces the formation of the Z-ring at midcell...Fac. de Ciencias QuímicasTRUEunpu

Inactivation of pathogens on food and contact surfaces using ozone as a biocidal agent

This study focuses on the inactivation of a range of food borne pathogens using ozone as a biocidal agent. Experiments were carried out using Campylobacter jejuni, E. coli and Salmonella enteritidis in which population size effects and different treatment temperatures were investigate