Hedgehog is an important morphogenic signal that directs pattern formation during embryogenesis, but its activity also remains present through adult life. It is now becoming increasingly clear that during the reproductive phase of life and beyond it continues to direct cell renewal (which is essential to combat the chronic environmental stress to which the body is constantly exposed) and counteracts vascular, osteolytic and sometimes oncological insults to the body. Conversely, down‐regulation of hedgehog signalling is associated with ageing‐related diseases such as (...) type 2 diabetes, neurodegeneration, atherosclerosis and osteoporosis. Hence, in this essay we argue that hedgehog signalling is not only important at the start of life, but also constitutes an important anti‐geriatric influence, and that enhanced understanding of its properties may contribute to developing rational strategies for healthy ageing and prevention of ageing‐related diseases.Also watch the Video Abstract. (shrink)

We investigate computable subshifts and the connection with effective symbolic dynamics. It is shown that a decidable Π01 class P is a subshift if and only if there exists a computable function F mapping 2ℕ to 2ℕ such that P is the set of itineraries of elements of 2ℕ. Π01 subshifts are constructed in 2ℕ and in 2ℤ which have no computable elements. We also consider the symbolic dynamics of maps on the unit interval.

Patients have the right to refuse their treatment; however, this refusal should be informed. We evaluated the quality of the informed refusal process in Iranian hospitals from patients' viewpoints. To this end, we developed a questionnaire that covered four key aspects of the informed refusal process including; information disclosure, voluntariness, comprehension, and provider-patient relationship. A total of 284 patients who refused their treatment from 12 teaching hospitals in the Isfahan Province, Iran, were recruited and surveyed to produce a convenience sample. (...) Patients' perceptions about the informed refusal process were scored and the mean scores of the four components were calculated. The findings showed that the practice of information disclosure was perceived to be moderate, however, comprehension, voluntariness and provider–patient relationship were perceived to be relatively good. We found that patients, who refused their care before any treatment had commenced, reported a lower quality of information disclosure and voluntariness. Patients informed by nurses and those who had not had a previous related admission, reported lower scores for comprehension and relationship. In conclusion, the process of obtaining informed refusal was relatively satisfactory except for levels of information disclosure. To improve current practices, Iranian patients need to be better informed about; different treatment options, consequences of treatment refusal, costs of not continuing treatment and follow-ups after refusal. Developing more informative refusal forms is needed. (shrink)

Background The emerging working conditions triggered by the COVID-19 pandemic have imposed numerous ethical challenges on the nurses, which, in turn, can negatively impact the nurses’ physical and mental health, and thus their work performance through intensifying negative emotions and psychological pressures. Aim The purpose of this study was to highlight the nurses’ perceptions of the ethical challenges that they faced regarding their self-care during the COVID-19 pandemic. Research design A qualitative, descriptive study with a content analysis approach. Participants and (...) research context The data were collected through semi-structured interviews with 19 nurses working in the COVID-19 wards of two university-affiliated hospitals. These nurses were selected using a purposive sampling method and the data were analyzed using a content analysis approach. Ethical considerations The study was approved by the TUMS Research Council Ethics Committee under the code: IR.TUMS.VCR.REC.1399.594. In addition, it is based on the participants’ informed consent and confidentiality. Findings Two themes and five sub-themes were identified, including ethical conflicts (the conflict between self-care and comprehensive patient care, prioritization of life, and inadequate care) and inequalities (intra- and inter-professional inequalities). Conclusion The findings demonstrated that the nurses’ care is a prerequisite for the patients’ care. Considering that the ethical challenges faced by nurses are related to unacceptable working conditions, organizational support, and lack of access to facilities such as personal protective equipment, it seems essential to support nurses and provide adequate working conditions to provide patients with quality care. (shrink)