• Development and Reproduction
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• v.12 no.2
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• pp.117-124
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• 2008

The efficient strategies to cope with unpredictable and/or harmful environmental changes have been developed by every organism in order to ensure its survival and continuity of it's own species. As a results, all living things on earth maintain dynamically internal stability via a process termed 'homeostasis' among physiological parameters despite of external environment changes. Stress is an emotional and physical response to threat homeostasis. Stress may have not only transient but rather permanent effect on the organism; recent evidence clearly show that prenatal stress could organize or imprint permanently physiological systems without any change in genetic codes, a process known as 'epigenetic programming'. In this review, a series of reproduction-associated events occurred in prenatally stressed male rats such as alteration in the structure of sexually dimorphic brain regions, modification of neurotransmitter metabolism, changes in reproductive endocrine status, and finally, disorders of sexual behavior will be introduced. The fetal brain is highly sensitive to prenatal programming and glucocorticoids in particular have powerful brain-programming properties. The chronic hyperactivation of fetal brain by maternal stress-induced glucocorticoid input will provide new program via increasing the neuroplasticities. This 'increased neuroplasticities' will be the basis for the 'increased phenotypic plasticities' rendering the organism's better adaptation to environmental challenges. In conclusion, organism who experienced 'harsh' environment in his fetal life seems to give up a certain portion of reproductive competence to make good chance of survival in his future life by epigenetic (re)programming.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.329-347
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• 2017

Early research into category-based feature inference reported various phenomena in human thinking including typicality, diversity, similarity effects, etc. Later research discovered that participants' prior knowledge has an extensive influence on these sorts of reasoning. The current research tested the effects of causal knowledge on feature inference and conducted modeling on the results. Participants performed feature inference for categories consisted of four features where the features were connected either in common cause or common effect structure. The results showed typicality effects along with violations of causal Markov condition in common cause structure and causal discounting in common effect structure. To model the results, it was assumed that participants perform feature inference based on the difference between the probabilities of an exemplar with the target feature and an exemplar without the target feature (that is, $p(E_{F(X)}{\mid}Cat)-p(E_{F({\sim}X)}{\mid}Cat)$). Exemplar probabilities were computed based on causal model theory (Rehder, 2003) and applied to inference for target features. The results showed that the model predicts not only typicality effects but also violations of causal Markov condition and causal discounting observed in participants' data.

• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.356-365
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• 2006

Background: Corticosteroids are known to be significant prognostic parameters in sepsis. Recently, an absolute and relative insufficiency of the corticosteroids system has often been reported to often develop particularly in severe sepsis. Degree of such an adrenal insufficiency not only has prognostic implications but also can be used to guide corticosteroids replacement therapy. The 24-hour urinary cortisol levels as well as serum cortisol concentrations were measured to assess the clinical significance and their relationship with the other parameters of sepsis, and also evaluated the clinical implications of the relative adrenal insufficiency. Methods: 26 consecutive patients with sepsis were enrolled. The basal random serum cortisol, ACTH, ADH, lactate levels and 24-hour urinary free cortisol amount were measured. The rapid ACTH ($250{\mu}g$) stimulation test was also performed. Results: Basal serum cortisol levels were higher in the non-survivors than in the survivors. The 24-hour urinary free cortisol levels were higher in the patients with severe sepsis than in those without. The serum cortisol levels strongly correlated with the serum ADH and lactate levels. The 24-hour urinary free cortisol levels strongly correlated with the serum cortisol and lactate levels. The fractional changes in the cortisol levels after the rapid ACTH stimulation tests correlated with the serum cortisol, ADH, and lactate levels. Conclusion: Both the serum cortisol and 24-hour urinary cortisol were found to be significant prognostic factors in sepsis, and showed a strong correlation with the other parameters. The relative adrenal insufficiency might also be an important clinical parameter.