Asexual species accumulate deleterious mutations through an irreversible process known as Muller's ratchet. Attempts to quantify the rate of the ratchet have ignored the role of temporal environmental heterogeneity even though it is common in nature and has the potential to affect overall ratchet rate. Here we examine Muller's ratchet in the context of conditional neutrality (i.e., mutations th...

When interacting with an interactive system to achieve a goal, a user utilizes his or her existing knowledge and constructs new knowledge consciously or unconsciously. Throughout the active process of knowledge exchange, accumulation and generation, the user’s mental models of the target system are built and constantly modified over time in order to obtain a desirable result. According to Drisc...

BACKGROUND AND OBJECTIVES Effects of maternal and paternal age on offspring autism and schizophrenia risks have been studied for over three decades, but inconsistent risks have often been found, precluding well-informed speculation on why these age-related risks might exist. METHODOLOGY To help clarify this situation we analysed a massive single population sample from Denmark including the fu...

This study aimed to evaluate the relationship between mental disorders at 30 years of age and social mobility by formally testing three hypotheses: Risk Accumulation; Critical Period; and Social Mobility. The study was performed using data from the 30-year follow-up of the Pelotas Birth Cohort Study, conducted in 1982, and data from previous follow-ups. The tool used to evaluate mental health w...

Mental processes are always accompanied by a varying amount of energy, i.e., are dynamic in nature. Excessive accumulation results in tension and discomfort. Discharge results in relief and pleasure. The process of repression plays an important part in his system. The term is applied to the conditions preventing mental processes entering consciousness. The ensuing mental conflict is responsible...

Under the traditional mutation load model based on multiplicative fitness effects, the load in a population is 1-e-U , where U is the genomic deleterious mutation rate. Because this load becomes high under large U, synergistic epistasis has been proposed as one possible means of reducing the load. However, experiments on model organisms attempting to detect synergistic epistasis have often focu...

Intake of excessive bromide can induce a condition termed bromism, with neurological, psychiatric, dermatological, and possibly endocrine effects. It has been suggested that intake of PB by PGW veterans may have induced symptoms of bromism, which may account for some illnesses in PGW veterans (Allan, 1997). This chapter evaluates the evidence for this hypothesis, briefly reviewing the symptoms,...

It has been well established that populations of RNA viruses transmitted throughout serial bottlenecks suffer from significant fitness declines as a consequence of the accumulation of deleterious mutations by the onset of Muller's ratchet. Bottlenecks are unavoidably linked to different steps of the infectious cycle of most plant RNA viruses, such as vector-mediated transmissions and systemic c...

A common test used to study the response of a transforming material to external constraint is due to Satoh and involves the cooling of a rigidly constrained tensile specimen while monitoring the stress that accumulates. Such tests are currently common in the invention of welding alloys which on phase transformation lead to a reduction in residual stresses in the final assembly. The test suffers...