Effects of Ionizing Radiations on Aging and Life Shortening in Human Populations

Evidence relating to the probable genetic consequences of exposing large human populations to low levels of ionizing radiations is reviewed. There is little reason to doubt that the production of mutations varies linearly with dose even at very low doses, and that most of the mutations have undesirable effects. Estimates of the probable numbers of seriously affected individuals resulting from a given exposure can be derived from the present frequencies of hereditary diseases and the expected increases in mutation rate. The degree of uncertainty is probably about an order of magnitude in either direction. With doses similar to those received from nuclear weapon testing, estimates of this kind will seem small if expressed as a percentage of the total population but may look large if expressed in terms of the absolute numbers of seriously affected individuals in a world population of two and one-half billion people. Much unnecessary confusion has resulted from the seemingly conflicting statements which have been drawn from this single fact. The greatest single source of uncertainty stems from a basic ignorance of the genetics of human population and of the factors responsible for a present load of hereditary abnormalities and diseases affecting at sometime during their lives at least 4% of all infants born.

Download Full-text

GENETIC EFFECTS OF IONIZING RADIATION

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y60-040 ◽

1960 ◽

Vol 38 (1) ◽

pp. 330-338 ◽

Cited By ~ 2

Author(s):

Howard B. Newcombe

Keyword(s):

Human Population ◽

Total Population ◽

Hereditary Diseases ◽

Human Populations ◽

World Population ◽

Nuclear Weapon Testing ◽

Order Of Magnitude ◽

Weapon Testing ◽

Low Levels ◽

Ionizing Radiations

Evidence relating to the probable genetic consequences of exposing large human populations to low levels of ionizing radiations is reviewed. There is little reason to doubt that the production of mutations varies linearly with dose even at very low doses, and that most of the mutations have undesirable effects. Estimates of the probable numbers of seriously affected individuals resulting from a given exposure can be derived from the present frequencies of hereditary diseases and the expected increases in mutation rate. The degree of uncertainty is probably about an order of magnitude in either direction. With doses similar to those received from nuclear weapon testing, estimates of this kind will seem small if expressed as a percentage of the total population but may look large if expressed in terms of the absolute numbers of seriously affected individuals in a world population of two and one-half billion people. Much unnecessary confusion has resulted from the seemingly conflicting statements which have been drawn from this single fact. The greatest single source of uncertainty stems from a basic ignorance of the genetics of human population and of the factors responsible for a present load of hereditary abnormalities and diseases affecting at sometime during their lives at least 4% of all infants born.

Download Full-text

The sense of obligation is culturally modulated

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002371 ◽

2020 ◽

Vol 43 ◽

Author(s):

Andrea Bender

Keyword(s):

Cultural Studies ◽

Cross Cultural ◽

Human Populations ◽

Cultural Group ◽

Target Article ◽

Sense Of Obligation ◽

Cross Cultural Studies

Abstract Tomasello argues in the target article that, in generalizing the concrete obligations originating from interdependent collaboration to one's entire cultural group, humans become “ultra-cooperators.” But are all human populations cooperative in similar ways? Based on cross-cultural studies and my own fieldwork in Polynesia, I argue that cooperation varies along several dimensions, and that the underlying sense of obligation is culturally modulated.

Download Full-text

Self-Injurious Behavior vs. Nonsuicidal Self-Injury

Crisis ◽

10.1027/0227-5910/a000127 ◽

2012 ◽

Vol 33 (2) ◽

pp. 106-112 ◽

Cited By ~ 3

Author(s):

Christopher M. Bloom ◽

Shareen Holly ◽

Adam M. P. Miller

Keyword(s):

Positive Reinforcement ◽

Empirical Investigation ◽

High Stress ◽

Animal Research ◽

Stress Conditions ◽

Human Populations ◽

Pharmacological Interventions ◽

Self Injury ◽

Cns Stimulant ◽

Nonsuicidal Self Injury

Background: Historically, the field of self-injury has distinguished between the behaviors exhibited among individuals with a developmental disability (self-injurious behaviors; SIB) and those present within a normative population (nonsuicidal self-injury; NSSI),which typically result as a response to perceived stress. More recently, however, conclusions about NSSI have been drawn from lines of animal research aimed at examining the neurobiological mechanisms of SIB. Despite some functional similarity between SIB and NSSI, no empirical investigation has provided precedent for the application of SIB-targeted animal research as justification for pharmacological interventions in populations demonstrating NSSI. Aims: The present study examined this question directly, by simulating an animal model of SIB in rodents injected with pemoline and systematically manipulating stress conditions in order to monitor rates of self-injury. Methods: Sham controls and experimental animals injected with pemoline (200 mg/kg) were assigned to either a low stress (discriminated positive reinforcement) or high stress (discriminated avoidance) group and compared on the dependent measures of self-inflicted injury prevalence and severity. Results: The manipulation of stress conditions did not impact the rate of self-injury demonstrated by the rats. The results do not support a model of stress-induced SIB in rodents. Conclusions: Current findings provide evidence for caution in the development of pharmacotherapies of NSSI in human populations based on CNS stimulant models. Theoretical implications are discussed with respect to antecedent factors such as preinjury arousal level and environmental stress.

Download Full-text