In modern society, stress reduction in the workplace is a pressing issue. Although many studies have been done on the psychological and physiological effects of indoor plants, the majority of them have been conducted in laboratory or quasi-office settings. The objective of this study was to verify the stress reduction effects of the presence of small indoor plants on employees in a real office setting. We investigated the changes in psychological and physiological stress before and after placing a plant on a worker’s desk. Sixty-three office workers at an electric company in Japan were the participants of this study. The participants were directed to take a 3-minute rest while sitting at their desk when they felt fatigue. There were two phases of the study: a control period without plants and an intervention period when the participants were able to see and care for a small plant. We measured psychological stress in the participants using the State-Trait Anxiety Inventory (STAI). As an index of physiological stress, the participants measured their own pulse rate throughout the study. STAI scores decreased significantly after the intervention period (P < 0.05). The ratio of the participants whose pulse rate lowered significantly after a 3-minute rest increased significantly during the intervention period (P < 0.05). Our study indicates that having opportunities to gaze intentionally at nearby plants on a daily basis in the work environment can reduce the psychological and physiological stress of office workers.

In the above article, the name of the fourth author was incorrectly published. Therefore, we herewith would like to publish the correct name.

The development of bulk metallic glasses as a prominent class of functional and structural materials has attracted considerable interest in the last years. One of the fundamental physical quantities necessary to describe the mechanical properties of the materials is the bulk modulus. In the present article, a simple method to estimate the bulk modulus and its pressure derivative is proposed. It is shown that these quantities can be estimated from the values of the constituent elements and their compositions. Comparison with measured data shows good agreement. The physical background of the method is discussed based on the jellium model of metals.

The objectives of this study were to detect age-related differences in activation of the prefrontal cortex (PFC) during the tasks of hand motions and to determine an activity-related task type activating the PFC. PFC activation during three tasks, three subtests of the Frontal Assessment Battery (FAB), was investigated in 77 healthy adults by using near-infrared spectroscopy (NIRS). The tasks were a motor programming task (FAB 3), a sensitivity-to-interference task (FAB 4) and an inhibitory control task (FAB 5). We divided participants into three age groups of Younger (20 -39 years), Middle-aged (40 -59 years), and Older (60 -81 years), and compared relative changes in oxygenated hemoglobin concentration in the PFC during the tasks. The activation in the frontal pole (FP) and the dorsolateral prefrontal cortex (DLPFC) during a motor programming task and a sensitivity-to-interference task showed no main effects by age. The results indicated that they were not likely to be affected by age-related cognitive decline compared to an inhibitory control task. In addition, in the Older group, a motor programming task induced significantly greater activation than a sensitivity-to-interference task at eleven channels out of twelve on which we focused (p < 0.05). It was suggested that some characteristic factors included in the motor programming task such as repetition of a series of hand motions and attention to action have the potential to contribute to PFC activation in older adults. These findings provide a clue to understanding daily activities available to suppress cognitive decline of older adults by activating the PFC.

No abstract