{ "id": "1610.08609", "version": "v1", "published": "2016-10-27T04:10:29.000Z", "updated": "2016-10-27T04:10:29.000Z", "title": "Systems of Delay Differential Equations: Analysis of a model with feedback", "authors": [ "Pablo Amster", "Carlos Alliera" ], "comment": "5 pages, 2 figures", "categories": [ "math.DS" ], "abstract": "Self-regulatory models are common in nature, as described e.g. in (\\cite{mur}), (\\cite{ha}) and (\\cite{Gb}).\\\\ Let us consider a system made up of a number of glands as a motivation. Each gland secretes a hormone that allows secretion in the {next} gland, which successively generates another hormone to stimulate the next one and so on. In the end, a final hormone is released which, by increasing its concentration, will inhibit the secretion of previous hormones that allowed the production process. This generates the decay of this hormone to a minimum threshold that re-activates the cycle again.\\\\ This behavior can be seen in other biochemical processes, such as enzymatic or bacterial models.\\\\ Topological degree is a useful tool to find stable equilibria in a wide variety of models with constant parameters and, furthermore, allows to deduce the existence of periodic solutions when the constant parameters are replaced by periodic functions.", "revisions": [ { "version": "v1", "updated": "2016-10-27T04:10:29.000Z" } ], "analyses": { "subjects": [ "34K13" ], "keywords": [ "delay differential equations", "constant parameters", "production process", "periodic functions", "self-regulatory models" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }