Utilization and dominance of spatially separated cues as a function of water deprivation

Utilization and dominance of physically separate redundant-relevant cues were measured in albino rats under moderate (18 h/day) or high (23.5 h/day) water deprivation. Cues were located on goal doors (brightness) and the floor (texture) in a two-choice discrimination apparatus. Three experiments were carried out with the following paradigms: incidental cue, redundant-relevant cue discrimination, and optional shift discrimination. Deprivation did not affect rate of acquisition of initial discrimination or cue dominance. Cue utilization, however, was inversely related to deprivation in redundant-relevant cue and optional shift discrimination tasks. These effects were limited, however. Over-training on the redundant-relevant cue task eliminated the effect. Within the optional shift situation, only animals that initially acquired a texture cue discrimination were affected by deprivation. Other factors affecting cue utilization in these experiments were also described and discussed.     

The technology policy experiment as a policy research tool

The use of experimentation as a policy change tool is described and assessed, based on the experience of the Experimental Technology Incentives Program (ETIP). ETIP conducted innovation-related policy experiments with U.S. government agencies in the areas of regulation, procurement, venture capital, R&D funding, and technology commercialization. A case study of a policy experiment with new analytical and institutional procedures for monitoring the impacts of venture capital market regulations is used to show how the policy experiment can provide an iterative and low-risk, low-cost approach to policy change. Equally important, instututionalization of the procedures for monitoring existing policies and the provision of decision-relevant information are shown to be important benefits from policy experimentation in the context of the overall policy change process. The reasons behind ETIP's termination after 10 years of operation are themselves important lessons for institutions involved in the development and management of industry growth policies.     

Insulator-based dielectrophoresis of mitochondria

Isolated mitochondria display a wide range of sizes plausibly resulting from the coexistence of subpopulations, some of which may be associated with disease or aging. Strategies to separate subpopulations are needed to study the importance of these organelles in cellular functions. Here, insulator-based dielectrophoresis (iDEP) was exploited to provide a new dimension of organelle separation. The dielectrophoretic properties of isolated Fischer 344 (F344) rat semimembranosus muscle mitochondria and C57BL/6 mouse hepatic mitochondria in low conductivity buffer (0.025–0.030 S/m) at physiological pH (7.2–7.4) were studied using polydimethylsiloxane (PDMS) microfluidic devices. First, direct current (DC) and alternating current (AC) of 0–50 kHz with potentials of 0–3000 V applied over a channel length of 1 cm were separately employed to generate inhomogeneous electric fields and establish that mitochondria exhibit negative DEP (nDEP). DEP trapping potential thresholds at 0–50 kHz were also determined to be weakly dependent on applied frequency and were generally above 200 V. Second, we demonstrated a separation scheme using DC potentials <100 V to perform the first size-based iDEP sorting of mitochondria. Samples of isolated mitochondria with heterogeneous sizes (150 nm–2 μm diameters) were successfully separated into sub-micron fractions, indicating the ability to isolate mitochondria into populations based on their size.     

Relationships between functional movement screen scores,maturation and physical performance in young soccer players

The purpose of this study was to examine relationships between functional movement screen scores, maturation and physical performance in young soccer players. Thirty males (11–16 years) were assessed for maturation, functional movement screen scores and a range of physical performance tests (squat jump, reactive strength index protocol and reactive agility cut). Older players significantly outperformed younger participants in all tests (P < 0.05; effect sizes = 1.25–3.40). Deep overhead squat, in-line lunge, active straight leg raise and rotary stability test were significantly correlated to all performance tests. In-line lunge performance explained the greatest variance in reactive strength index (adjusted R² = 47%) and reactive agility cut (adjusted R² = 38%) performance, whilst maturation was the strongest predictor of squat jump performance (adjusted R² = 46%). This study demonstrated that variation of physical performance in youth soccer players could be explained by a combination of both functional movement screen scores and maturation.     

Tactile training facilitates infants' ability to reach to targets on the body

This longitudinal study investigated the effect of experience with tactile stimulation on infants' ability to reach to targets on the body, an important adaptive skill. Infants were provided weekly tactile stimulation on eight body locations from 4 to 8 months of age (N = 11), comparing their ability to reach to the body to infants in a control group who did not receive stimulation (N = 10). Infants who received stimulation were more likely to successfully reach targets on the body than controls by 7 months of age. These findings indicate that tactile stimulation facilitates the development of reaching to the body by allowing infants to explore the sensorimotor correlations emerging from the stimulation.