Japanese quail (Coturnix japonica) were reinforced with food for traversing a runway for either 18 or 36 trials, administered at a rate of 1 trial per day. Then, all animals received 18 extinction trials. The latency to run from the start box to the goal box was the dependent variable. Extinction was significantly slower in animals that had received 50% partial reinforcement during acquisition,...

We study the dynamics of behavioral transitions when European starlings (Sturnus vulgaris) experience stepwise changes in the value of a meaningful time interval. Subjects were primed to respond at a certain time T1. After extensive training, the primed time changed to a new value T2. In Experiment 1 subjects were reinforced on 40% of the trials and they experienced a single transition which la...

objectives: this study sought to assess the level of stress in general dentists in the 2nd district of tehran city in 2014 to find out the stressors and suggest strategies to overcome them. methods: this descriptive, analytical, cross-sectional study was conducted on 130 general dentists from the 2nd district of tehran city selected via weighted randomization. level of stress was assessed using...

objective: violence during pregnancy has been associated with adverse pregnancy outcomes. this study aimed to explore the link between psychological violence (psv) and pregnancy outcomes in terms of maternal and birth for the first time in women attending mazandaran university of medical sciences (mums) primary health centers (phcs) in iran. methods: prospective cohort of 1461 pregnant women ex...

background: nursing is naturally a stressful job. stress in nurses can cause depression, isolation from patients, absence and decrease in their qualification. this study aimed to determine the causes of job stress in nurses of kashan, iran. materials and methods: in this cross-sectional study, 189 nurses from kashan hospitals of different wards were studied. the information collection tool was ...

background: hypoactive sexual desire disorder is the most common sexual disorder among women, which interferes with their various functions. activity of brain-behavioral and psychological distress systems are considered among factors affecting sexual function. objectives: the present study aimed to compare women with hypoactive sexual desire and normal women in terms of brain-behavioral and psy...

background: very few studies have utilized specific criteria to assess mental disorders in brain tumor patients. this study aimed to diagnose mental disorders in this population using dsm-iv (depression, sleep, and mood) criteria. methods: from march 2007 to july 2009, the surgically treated patients with intracranial neoplasm were included in the study. these patients were examined in an ambul...

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Background: Dental students who are at clinical or educational stage, are under environmental stress. The cumulative effect of clinical and educational stressors may also have negatively impact performance of clinical education in the long term and lead to mental and physical disorders. Our aim was to recognize and compare the stressful factors of dental environment among the students of clinic...