ABSTRACT
The observed value Λobs of the cosmological constant Λ is extremely smaller than theoretical expectations, and the anthropic argument has been proposed as a solution to this problem because galaxies do not form when Λ â« Λobs. However, the contemporary galaxy formation theory predicts that stars form even with a high value of Λ/Λobs â¼ 50, which makes the anthropic argument less persuasive. Here we calculate the probability distribution of Λ using a model of cosmological galaxy formation, considering extinction of observers caused by radiation from nearby supernovae. The life survival probability decreases in a large Λ universe because of higher stellar density. Using a reasonable rate of lethal supernovae, we find that the mean expectation value of Λ can be close to Λobs; hence this effect may be essential to understand the small but nonzero value of Λ. It is predicted that we are located on the edge of habitable regions about stellar density in the Galaxy, which may be tested by future exoplanet studies.
Subject(s)
Cosmic Radiation , Galaxies , Exobiology , Stars, CelestialABSTRACT
INTRODUCTION: Studies on autism spectrum disorder in recent years have controversially indicated similarities with schizophrenia. Cognitive dysfunction is present in both disorders, and while there is a rich array of interventions for cognitive dysfunction in schizophrenia, there are few such treatments for autism spectrum disorder. In this study, we have investigated a potentially useful approach in autism spectrum disorder by comparing autism spectrum disorder with schizophrenia in regard to the characteristics of cognitive dysfunction and therapeutic response to cognitive remediation therapy. METHOD: We studied seven patients with autism spectrum disorder and eight patients with schizophrenia, using a frontal/executive programme as the intervention. The characteristics of cognitive dysfunction in autism spectrum disorder before frontal/executive programme and the therapeutic response to frontal/executive programme in autism spectrum disorder patients were compared with those in schizophrenia patients, based on evaluation of cognitive function and social function. The changes in cognitive and social function after treatment in each patient group were compared using the Mann-Whitney's U test. RESULTS: The severity of cognitive dysfunction did not differ significantly between autism spectrum disorder and schizophrenia. Frontal/executive programme was effective in autism spectrum disorder, with subjects showing about the same therapeutic response as in schizophrenia. CONCLUSION: Frontal/executive programme appears to be useful for patients with autism spectrum disorder. Furthermore, the similarities in cognitive dysfunction and therapeutic response between autism spectrum disorder and schizophrenia are highly relevant to the recent debate concerning the similarity between these two disease concepts.
ABSTRACT
OBJECTIVE: The cognitive features and treatment of autism spectrum disorder have been the subject of much debate in recent years. Therapeutic approaches to date have focused on skills acquisition, support tailored to the characteristics of autism spectrum disorder, and interventions in social cognitive functioning; there have been few reports describing interventions aimed at neurocognitive dysfunction. In this study, we focus on impairment of executive functioning in autism spectrum disorder patients and investigate improvements in executive functioning and their generalization to social functioning. METHOD: The intervention adopted for this study was cognitive remediation therapy using the frontal/executive program. To investigate the effectiveness of frontal/executive program, 15 subjects who consented to participate in the study were randomly assigned to an intervention group or control group. Frontal/executive program was administered to the intervention group for about six months. Both groups were evaluated using the same scales: BACS-J, WCST, and CPT for cognitive assessment; SCoRS-J, GAF, and LASMI for social functioning; and GSE for self-efficacy. RESULTS: Both groups had lower scores for cognitive functioning than normal individuals at baseline. After completion of frontal/executive program, the intervention group showed improved performance on BACS-J for overall score, digit sequencing, verbal fluency, and Tower of London tasks. Improvements were also seen on SCoRS-J and LASMI scales of social functioning. CONCLUSIONS: This was the first study to use frontal/executive program to focus on neurocognitive dysfunction in autism spectrum disorder patients. Frontal/executive program is effective in improving impaired executive functioning in autism spectrum disorder patients and may also lead to improvements in some aspects of social functioning.
