Networks as a Privileged Way to Develop Mesoscopic Level Approaches in Systems Biology

The methodologies advocated in computational biology are in many cases proper system-level approaches. These methodologies are variously connected to the notion of “mesosystem” and thus on the focus on relational structures that are at the basis of biological regulation. Here, I describe how the formalization of biological systems by means of graph theory constitutes an extremely fruitful approach to biology. I suggest the epistemological relevance of the notion of graph resides in its multilevel character allowing for a natural “middle-out” causation making largely obsolete the traditional opposition between “top-down” and “bottom-up” styles of reasoning, so fulfilling the foundation dream of systems science of a direct link between systems analysis and the underlying physical reality

Second Generation General System Theory: Perspectives in Philosophy and Approaches in Complex Systems

Following the classical work of Norbert Wiener, Ross Ashby, Ludwig von Bertalanffy and many others, the concept of System has been elaborated in different disciplinary fields, allowing interdisciplinary approaches in areas such as Physics, Biology, Chemistry, Cognitive Science, Economics, Engineering, Social Sciences, Mathematics, Medicine, Artificial Intelligence, and Philosophy. The new challenge of Complexity and Emergence has made the concept of System even more relevant to the study of problems with high contextuality. This Special Issue focuses on the nature of new problems arising from the study and modelling of complexity, their eventual common aspects, properties and approaches—already partially considered by different disciplines—as well as focusing on new, possibly unitary, theoretical frameworks. This Special Issue aims to introduce fresh impetus into systems research when the possible detection and correction of mistakes require the development of new knowledge. This book contains contributions presenting new approaches and results, problems and proposals. The context is an interdisciplinary framework dealing, in order, with electronic engineering problems; the problem of the observer; transdisciplinarity; problems of organised complexity; theoretical incompleteness; design of digital systems in a user-centred way; reaction networks as a framework for systems modelling; emergence of a stable system in reaction networks; emergence at the fundamental systems level; behavioural realization of memoryless functions

Complexity Science in Human Change

This reprint encompasses fourteen contributions that offer avenues towards a better understanding of complex systems in human behavior. The phenomena studied here are generally pattern formation processes that originate in social interaction and psychotherapy. Several accounts are also given of the coordination in body movements and in physiological, neuronal and linguistic processes. A common denominator of such pattern formation is that complexity and entropy of the respective systems become reduced spontaneously, which is the hallmark of self-organization. The various methodological approaches of how to model such processes are presented in some detail. Results from the various methods are systematically compared and discussed. Among these approaches are algorithms for the quantification of synchrony by cross-correlational statistics, surrogate control procedures, recurrence mapping and network models.This volume offers an informative and sophisticated resource for scholars of human change, and as well for students at advanced levels, from graduate to post-doctoral. The reprint is multidisciplinary in nature, binding together the fields of medicine, psychology, physics, and neuroscience

The Relationship of Self-Renewal and Accelerated Senescence in Response to DNA Damage in Normal and Tumour Cells

Elektroniskā versija nesatur pielikumusPretvēža terapijā lietotajās dozās radio- un ķīmijterapijā lielākā vēža šūnu daļa paātrināti novecojas. Diemžēl terapijas izraisīta novecošanās var būt atgriezeniska, tādēļ bija nepieciešams izpētīt par šo procesu atbildīgos mehānismus. Pirmo reizi tika atklāta pašatjaunošanās aktivācija tetraploīdos normālos cilvēka fibroblastos agrīnas novecošanās stadijā un tumora supresora P53 atkarīga vienlaicīga pašatjaunošanās un novecošanās faktoru aktivācija teratokarcinomas šūnās pēc apstrādes ar etopozīdu, kas izraisa DNS bojājumus. Kopā šie rezultāti norāda uz novecošanās un pašatjaunošanās ko-eksistenci atbildē uz DNS bojājumu kā ģeneralizētu mehānismu šūnu bipotencialitātei. Turklāt tika noskaidrota novecošanos pavadošas autofāgijas nozīme bi-potencialitātes un izdzīvošanas pēc terapijas atbalstam vēža šūnās, kā arī hromosomu teritoriju ekspansija terapijas inducētās poliploīdās šūnās, kas varētu nodrošināt transkripcijas aktivāciju un šūnu pārprogrammēšanu.In the doses used in cancer chemo-radio-therapy of patients most cancer cells undergo accelerated senescence. Unfortunately, senescence induced by therapy may be reversible, the mechanisms of reverse needed exploration. For the first time we discovered activation of self-renewal in tetraploid presenescent normal human fibroblasts and P53 dependent simultaneous activation of self-renewal and senescence regulators in etoposide treated teratocarcinoma cells. Together these results indicate the generality of coupling between senescence and stemness programs occurring in DNA damage response. Furthermore, we described importance of senescence acompanying autophagy for support of bi-potentiality and survival of DNA damaged tumour cells, as well as expansion of chromosome territories in polyploid cells which amay favour transcription activation and reprograming