Does Hand-Dominance Matter in Non-Standard Visuomotor Transformations?

Previous nonstandard visuomotor transformation studies using variations of eye-hand coupling and decoupling tasks focused on dominant hand use. The present study expanded this work by including the non-dominant hand. Twenty-four right-hand dominant adults (M = 21 yrs.; 12 females) slid their index finger along a vertical or horizontal touchscreen to move a cursor that was always displayed in the vertical plane. In four different action-perception conditions, the finger and cursor moved either in the same plane and direction or in the other plane and/or opposite direction. Performance differed between the hands only for movement trajectory related variables but not for endpoint related measures. Across conditions the initial direction error was larger when performing with the non-dominant hand (p \u3c 0.001). A significant hand × cursor direction × cursor plane interaction for path length (p \u3c 0.05) revealed longer movement trajectories for the non-dominant hand compared to the dominant hand in conditions with none or one level of eye-hand decoupling, and similar hand performance when movements were made in the horizontal plane with reversed cursor direction, i.e., two eye-hand decoupling levels. Our findings suggest a non-dominant hand overall eye-hand coordination deficit for spatial planning and an inversely related deficit to the eye-hand decoupling level for trajectory execution

Change in the Gender Division of Domestic Work after Mummy or Daddy Took Leave: An Examination of Alternative Explanations

This study investigates how the duration of child care leave taken by mothers and fathers relates to changes in couples' division of housework and child care after postnatal labour market return in Germany. It explores whether take-up of child care related leave may impact the gender division of domestic work beyond the period of leave and examines three theoretical explanations: 1) development of domestic work skills, 2) bargaining power based on economic resources, and 3) adaptations in gender role or parenting identities. Using data from the German Socio-Economic Panel (1992-2012) on 797 and 762 couples with a first or second birth, respectively, we applied OLS regression models with lagged dependent variables in combination with Heckman selection correction. The results suggested that dual-earner couples where mothers took longer leaves experienced a greater shift towards a gender-traditional division of domestic labour after childbirth even in the medium-term after labour market return. The linear relationship and stronger effects on the division of child care than for housework lent support to identity-based explanations. Paternal leave take-up was associated with a more equal division of housework and child care after first births but not after second birth transitions. The relationship with the leave duration was less clear. In terms of explaining the mechanisms for fathers, the findings provided greatest support for explanations relating to domestic skills development possibly in combination with changes in fathering identities

Mechanobiological Modulation of Cytoskeleton and Calcium Influx in Osteoblastic Cells by Short-Term Focused Acoustic Radiation Force

Mechanotransduction has demonstrated potential for regulating tissue adaptation in vivo and cellular activities in vitro. It is well documented that ultrasound can produce a wide variety of biological effects in biological systems. For example, pulsed ultrasound can be used to noninvasively accelerate the rate of bone fracture healing. Although a wide range of studies has been performed, mechanism for this therapeutic effect on bone healing is currently unknown. To elucidate the mechanism of cellular response to mechanical stimuli induced by pulsed ultrasound radiation, we developed a method to apply focused acoustic radiation force (ARF) (duration, one minute) on osteoblastic MC3T3-E1 cells and observed cellular responses to ARF using a spinning disk confocal microscope. This study demonstrates that the focused ARF induced F-actin cytoskeletal rearrangement in MC3T3-E1 cells. In addition, these cells showed an increase in intracellular calcium concentration following the application of focused ARF. Furthermore, passive bending movement was noted in primary cilium that were treated with focused ARF. Cell viability was not affected. Application of pulsed ultrasound radiation generated only a minimal temperature rise of 0.1°C, and induced a streaming resulting fluid shear stress of 0.186 dyne/cm2, suggesting that hyperthermia and acoustic streaming might not be the main causes of the observed cell responses. In conclusion, these data provide more insight in the interactions between acoustic mechanical stress and osteoblastic cells. This experimental system could serve as basis for further exploration of the mechanosensing mechanism of osteoblasts triggered by ultrasound

Effect of low-intensity therapeutic ultrasound on wound healing in rats subjected to third-degree burns

PURPOSE: To determine the effectiveness of low-intensity therapeutic ultrasound (LITUS) on wound healing in rats with third-degree burns. METHODS: Twenty rats were divided into the Control Group that comprised four rats without third-degree burns that did not undergo LITUS, the Burned Group (BG), comprising eight rats with third-degree burns that did not undergo LITUS, and the Burned with Treatment Group (BTG), comprising eight rats with third-degree burns that were administered LITUS. LITUS began 24 h after injury and involved daily applications for 8 min at 0.1 W/cm2 for 14 days. RESULTS: The BTG lost less weight than the BG (Q=2.75; p<0.05). No visible differences were apparent among the groups' lesions on day 4. By the end of treatment, wound healing was more evident in the BTG. No statistically significant differences were found between the BG and the BTG in relation to the parameters measured using the histological changes in burn wound healing scoring system. CONCLUSION: The LITUS protocol applied to the animals with third-degree burns accelerated the formation of fibrin-leukocyte crusts and significantly reduced weight loss. However, burn wound healing was not accelerated