The role of conscious control in maintaining stable posture

© 2017 Elsevier B.V. This study aimed to examine the relationship between conscious control of movements, as defined by the Theory of Reinvestment (Masters & Maxwell, 2008; Masters, Polman, & Hammond, 1993), and both traditional and complexity-based COP measures. Fifty-three young adults (mean age = 20.93 ± 2.53 years), 39 older adults with a history of falling (mean age = 69.23 ± 3.84 years) and 39 older adults without a history of falling (mean age = 69.00 ± 3.72 years) were asked to perform quiet standing balance in single- and dual-task conditions. The results showed that higher scores on the Movement Specific Reinvestment Scale (MSRS; Masters, Eves, & Maxwell, 2005; Masters & Maxwell, 2008), a psychometric measure of the propensity for conscious involvement in movement, were associated with larger sway amplitude and a more constrained (less complex) mode of balancing in the medial–lateral direction for young adults only. Scores on MSRS explained approximately 10% of total variation in the medial–lateral sway measures. This association was not apparent under dual-task conditions, during which a secondary task was used to limit the amount of cognitive resources available for conscious processing. No relationship between postural control and score on the MSRS was found for either older adult fallers or non-fallers. Possible explanations for these results are discussed

The Potential of Antimicrobial Peptides as Biocides

Antimicrobial peptides constitute a diverse class of naturally occurring antimicrobial molecules which have activity against a wide range of pathogenic microorganisms. Antimicrobial peptides are exciting leads in the development of novel biocidal agents at a time when classical antibiotics are under intense pressure from emerging resistance, and the global industry in antibiotic research and development stagnates. This review will examine the potential of antimicrobial peptides, both natural and synthetic, as novel biocidal agents in the battle against multi-drug resistant pathogen infections

Should Rehabilitation Specialists Use External Focus Instructions When Motor Learning Is Fostered? A Systematic Review

According to the Constrained Action Hypothesis, motor learning is believed to be more efficient when an external focus (EF) of motor control is given to the performer instead of an internal focus (IF) of motor control. This systematic review investigated whether findings of studies focusing on the Constrained Action Hypothesis may be transferred to rehabilitation settings by assessing the methodological quality and risk of bias (ROB) of available randomized controlled trials (RCTs). Of the 18 selected reports representing 20 RCTs, the methodological quality was rather low, and the majority of the reports appeared to have a high ROB. The 18 reports included 68 patients tested in a rehabilitation setting and 725 healthy participants. The time scale of the motor learning processes presented in the selected articles was heterogenic. The results of this systematic review indicate that the assumption that an external focus of control is to be preferred during motor learning processes is not sufficiently substantiated. The level of available evidence is not large enough to warrant transfer to patient populations (including children and the elderly) and raises doubts about research with healthy individuals. This implies that based on the methodology used so far, there seems to be insufficient evidence for the superiority of an external focus of control, neither in healthy individuals nor in clinical populations. The relationship between EF instructions and motor learning research and its effect in both patient rehabilitation settings and healthy populations requires further exploration. Future adequately powered studies with low ROB and with rehabilitation populations that are followed over extended time periods should, therefore, be performed to substantiate or refute the assumption of the superiority of an EF in motor learning

Antiplasmodial Properties of Acyl-Lysyl Oligomers in Culture and Animal Models of Malaria▿

Our previous analysis of antiplasmodial properties exhibited by dodecanoyl-based oligo-acyl-lysyls (OAKs) has outlined basic attributes implicated in potent inhibition of parasite growth and underlined the critical role of excess hydrophobicity in hemotoxicity. To dissociate hemolysis from antiplasmodial effect, we screened >50 OAKs for in vitro growth inhibition of Plasmodium falciparum strains, thus revealing the minimal requirements for antiplasmodial potency in terms of sequence and composition, as confirmed by efficacy studies in vivo. The most active sequence, dodecanoyllysyl-bis(aminooctanoyllysyl)-amide (C12K-2α8), inhibited parasite growth at submicromolar concentrations (50% inhibitory concentration [IC50], 0.3 ± 0.1 μM) and was devoid of hemolytic activity (<0.4% hemolysis at 150 μM). Unlike the case of dodecanoyl-based analogs, which equally affect ring and trophozoite stages of the parasite developmental cycle, the ability of various octanoyl-based OAKs to distinctively affect these stages (rings were 4- to 5-fold more sensitive) suggests a distinct antiplasmodial mechanism, nonmembranolytic to host red blood cells (RBCs). Upon intraperitoneal administration to mice, C12K-2α8 demonstrated sustainable high concentrations in blood (e.g., 0.1 mM at 25 mg/kg of body weight). In Plasmodium vinckei-infected mice, C12K-2α8 significantly affected parasite growth (50% effective dose [ED50], 22 mg/kg) but also caused mortality in 2/3 mice at high doses (50 mg/kg/day × 4)