Towards a Processual Microbial Ontology

types: ArticleStandard microbial evolutionary ontology is organized according to a nested hierarchy of entities at various levels of biological organization. It typically detects and defines these entities in relation to the most stable aspects of evolutionary processes, by identifying lineages evolving by a process of vertical inheritance from an ancestral entity. However, recent advances in microbiology indicate that such an ontology has important limitations. The various dynamics detected within microbiological systems reveal that a focus on the most stable entities (or features of entities) over time inevitably underestimates the extent and nature of microbial diversity. These dynamics are not the outcome of the process of vertical descent alone. Other processes, often involving causal interactions between entities from distinct levels of biological organisation, or operating at different time scales, are responsible not only for the destabilisation of pre-existing entities, but also for the emergence and stabilisation of novel entities in the microbial world. In this article we consider microbial entities as more or less stabilised functional wholes, and sketch a network-based ontology that can represent a diverse set of processes including, for example, as well as phylogenetic relations, interactions that stabilise or destabilise the interacting entities, spatial relations, ecological connections, and genetic exchanges. We use this pluralistic framework for evaluating (i) the existing ontological assumptions in evolution (e.g. whether currently recognized entities are adequate for understanding the causes of change and stabilisation in the microbial world), and (ii) for identifying hidden ontological kinds, essentially invisible from within a more limited perspective. We propose to recognize additional classes of entities that provide new insights into the structure of the microbial world, namely ‘‘processually equivalent’’ entities, ‘‘processually versatile’’ entities, and ‘‘stabilized’’ entities.Economic and Social Research Council, U

Meniscus pathology, osteoarthritis and the treatment controversy.

The menisci are internal structures that are of central importance for a healthy knee joint; they have a key role in the structural progression of knee osteoarthritis (OA), and the risk of the disease dramatically increases if they are damaged by injury or degenerative processes. Meniscus damage might be considered a signifying feature of incipient OA in middle-aged and elderly people. As approximately every third knee of people in these groups has a damaged meniscus, tears are common incidental findings of knee MRI. However, as most tears do not cause symptoms, careful clinical evaluation is required to determine if a damaged meniscus is likely to directly impact a patient's symptoms. Conservative management of patients with knee pain and a degenerative meniscal tear should be considered as a first-line therapy before surgical treatment is contemplated. Patients with mechanical interference of joint movements, such as painful catching or locking, might need surgical treatment with meniscal repair if possible. In a subset of patients, meniscal resection might relieve pain and other symptoms that potentially originate directly from the torn meniscus. However, the possibility of an increased risk of OA if functional meniscal tissue is removed cannot be overlooked