Original Knowledge and True Enlightenment: Ranke's Kritik in Context

no abstrac

Original Knowledge and True Enlightenment: Ranke's Kritik in Context

no abstrac

Influence of irradiation and chemotherapy on the ovaries of children with abdominal tumours.

The ovaries of children with abdominal tumours were studied in 12 autopsy specimens. Ovaries from 25 children who died in accidents or after a short acute disease served as controls. All ovaries from normal children showed follicle growth, but follicle development was inhibited in 67% of the children with abdominal tumours. The effect of treatment with cytotoxic drugs and/or abdominal irradiation on ovarian morphology was investigated. Normal ovaries were found only in children who had received no chemotherapy or a short course. All patients who had been treated with radiation therapy either alone or in conjunction with chemotherapy had severely damaged ovaries: follicle growth was inhibited in all cases, and the number of small non-growing follicles was markedly reduced in most. It is argued that abdominal irradiation might impair follicle development as well as destroy small follicles

Integrating the Numerical Pain Rating Scale (NPRS) with an Eye Tracker: Feasibility and Initial Validation

This chapter details the integration of a Numerical Rating Scale (NPRSETI) with a portable eye tracker, enabling the assessment of pain in conditions in which verbal communication and use of hands are limited (e.g., advanced Amyotrophic lateral sclerosis, ALS). After detailing the construction of the NPRSETI, we describe its validation in an outpatient pain clinic. More specifically, thirty chronic pain patients performed the NPRSETI and filled a conventional NPRS (order was pseudo-randomized). Eye movements, including gaze direction and additional eye movement measures (e.g., saccade rate), were recorded, while participants rated their pain using the NPRSETI. The study’s findings indicated no significant differences in pain severity ratings of the NPRSETI and conventional NPRS. Notably, ratings using the two scales were highly correlated (r = 0.99). NPRSETI’s ratings were also strongly associated with participants’ currently experienced pain rating using the Brief Pain Inventory (BPI). The findings provide initial proof of concept for integrating conventional pain rating scales with an eye tracker and validate the NPRSETI compared with the well-validated and commonly used NPRS. Enhanced usability and decreasing costs of eye trackers will ease the additional research mandated to validate these preliminary findings and hopefully advance their integration into clinical practice

Bridging Time Scales in Cellular Decision Making with a Stochastic Bistable Switch

Cellular transformations which involve a significant phenotypical change of the cell's state use bistable biochemical switches as underlying decision systems. In this work, we aim at linking cellular decisions taking place on a time scale of years to decades with the biochemical dynamics in signal transduction and gene regulation, occuring on a time scale of minutes to hours. We show that a stochastic bistable switch forms a viable biochemical mechanism to implement decision processes on long time scales. As a case study, the mechanism is applied to model the initiation of follicle growth in mammalian ovaries, where the physiological time scale of follicle pool depletion is on the order of the organism's lifespan. We construct a simple mathematical model for this process based on experimental evidence for the involved genetic mechanisms. Despite the underlying stochasticity, the proposed mechanism turns out to yield reliable behavior in large populations of cells subject to the considered decision process. Our model explains how the physiological time constant may emerge from the intrinsic stochasticity of the underlying gene regulatory network. Apart from ovarian follicles, the proposed mechanism may also be of relevance for other physiological systems where cells take binary decisions over a long time scale.Comment: 14 pages, 4 figure