The Influence of Task Characteristics on the Intermanual Asymmetry of Motor Overflow

The two studies reported here were designed to test the proposition that greater motor overflow occurs when movements are performed by the non-dominant hand. Unlike previous studies using normal adults, the task in these studies did not require force production. In the first study, a group of 19 right-handed participants performed unweighted finger lifting. That the frequency of motor overflow occurrence was the same regardless of which hand performed the task, did not support findings from other studies where tasks involving force production resulted in more overflow when performed by the non-dominant hand. To investigate further the influence of task characteristics on motor overflow occurrence, in the second study participants were required to remember and reproduce a prescribed sequence of four finger lifts. Left- and right-handed participants ( N =30) performed both single and sequenced finger lifting. The relative frequency of motor overflow (unintended lifts of fingers of the passive hand) was compared between hand preference groups, active hand and task type (single/sequenced). Contrary to the expectation that motor overflow would be greater for the sequenced finger lifting task, overflow was exhibited with a significantly greater frequency on single finger lifting. This finding indicates that task characteristics influence the pattern of overflow occurrence in normal adults. The task used in this study did not involve force production and did not result in an intermanual asymmetry of motor overflow. This contrasts with findings from other studies requiring adults to exert forces where greater overflow occurred when the non-dominant hand was active. However, this study confirms previous findings which show that left-handers produce greater overflow compared to right-handers regardless of the task being performed and the hand performing the task.

Learning to take charge : women's experiences of living with endometriosis

This paper describes aspects of a study that was conducted to determine women's needs for information related to laparoscopy for endometriosis. Sixty-one women attended focus groups, during which they described endometriosis as a disease of multiple losses: of relationships, of career and of a sense of self-worth. The women indicated that the pathway to diagnosis and treatment had been long and unnecessarily difficult. Many women said that they had reached a point where they decided enough was enough: the medical merry-go-round had to finish. They had to become assertive, take control and decide for themselves how they were going to manage their disease and their quality of life. For all but one woman in the study, complementary therapies were vital. For some women, alternative therapies had replaced allopathic medicine completely. Complementary/alternative therapies were a mechanism for regaining control.

The charge effect of cationic surfactants on the elimination of fibre beads in the electrospinning of polystyrene

Polystyrene nanofibres were electrospun with the inclusion of cationic surfactants, dodecyltrimethylammonium bromide (DTAB) or tetrabutylammonium chloride (TBAC), in the polymer solution. A small amount of cationic surfactant effectively stopped the formation of beaded fibres during the electrospinning. The cationic surfactants were also found to improve the solution conductivity, but had no effect on the viscosity. Only DTAB had an effect on the surface tension of the polymer solution, the surface tension decreasing slightly with an increase in the concentration of DTAB.

The formation of beaded fibres was attributed to an insufficient stretch of the filaments during the whipping of the jet, due to a low charge density. Adding the cationic surfactants improved the net charge density that enhanced the whipping instability. The jet was stretched under stronger charge repulsion and at a higher speed, resulting in an exhaustion of the bead structure. In addition, a polymer/surfactant interaction was found in the polystyrene–DTAB solution system, while this interaction was not found in the polystyrene–TBAC system. The polymer/surfactant interaction led to the formation of thinner fibres than those formed in the absence of the interaction.

The effects of a non-ionic surfactant, Triton X-405, on the electrospun fibres were also studied. The addition of Triton X-405 did not eliminate the fibre beads, but reduced the bead numbers and changed the morphology. Triton X-405 slightly improved the solution conductivity, and had a minor effect on the surface tension, but no effect on the viscosity.

Steric and electronic factors influencing recognition by a simple, charge neutral norbornene based anion receptor

Based on 1H NMR studies, subtle electronic factors rather than pre-organisation dictate the binding stoichiometry of the new, norbornene based, anion hosts 1 and 2 with acetate, however, the binding of dihydrogenphosphate appears to be based solely on steric constraints.

Assuming responsibility : teachers taking charge of their professional development

The paper reports on some of the findings of an extensive study undertaken in Victoria as part of a national Science, ICT and Mathematics Education in Rural and Regional Australia (SiMERR) project. One of the significant findings of the study was the extent to which teachers in the schools where the study data were collected took responsibility for many aspects of their own professional development. This was not at the expense of, but rather was in addition to, their involvement in school- and region-based professional development activity. The study also identifies some of the challenges faced, mostly related to the location of their schools in a rural or regional setting.

Asymmetry in volume between dominant and nondominant upper limbs in young tennis players

This study aimed at demonstrating the asymmetry in volume between the dominant and nondominant upper limbs in tennis players, controlled for maturity status. Upper limb volumes on both sides were calculated in 72 tennis players and 84 control subjects, using the truncated cone method. The participants’ maturity status was determined using the predicted age at peak height velocity (PHV). The results showed significant larger side-to-side asymmetry in volume in tennis groups than
in control groups. These findings suggested that, even before PHV, specific-sport adaptations occurred in the dominant upper limb in tennis players.

Investigating business cycle asymmetry for the G7 countries : evidence from over a century of data

In this paper we test for asymmetric behaviour of business cycles for the G7 countries, using the entropy-based test for asymmetry suggested by Racine and Maasoumi [Racine, J.S., & Maasoumi, E. (in press-a). A versatile and robust metric entropy test of time-reversibility, and other hypotheses, Journal of Econometrics; Racine, J.S., & Maasoumi, E. (in press-b). A robust entropy based test for asymmetry. Econometric Reviews.]. We find overwhelming evidence of symmetry. In only 14% of the cases, we find some evidence of asymmetric behaviour of GDP and per capita GDP. More importantly, the period marked by the flexible exchange rate regime, over which much of the empirical work for the G7 countries has been conducted, evidence suggests that the two GDP series are symmetric.

Towards a better understanding of 'delocalized charge' in ionic liquid anions

One of the main characteristics that are attributed to ionic liquids (especially those with a low melting point) is that the anions comprising the ionic liquids possess a certain degree of charge delocalization as compared to anions in traditional molten salts. Based on the proton affinity equilibrium we proposed a new energetic criterion that can be used as a measure of charge delocalization. The proposed proton affinity comparison quantifies the extent to which ionic liquid anions are delocalized. Thus it should lead to a better understanding towards the design of task-specific ionic liquids. Therefore, this criterion can be applied to newly designed anions to assure that the extent of charge delocalization falls within the same range of values on the proton affinity scale as other commonly used ionic liquid anions.

Nanoparticle enhanced conductivity in organic ionic plastic crystals : space charge versus strain induced defect mechanism

High conductivity in solid-state electrolytes is a critical requirement for many advanced energy and other electrochemical applications. Plastic crystalline materials have shown promise in this regard, and the inclusion of nanosized inorganic particles in both amorphous and crystalline materials has indicated order of magnitude enhancements in ion transport induced by space charge or other defect enhancement. In this paper we present conductivity enhancements in the plastic crystal N,N‘-ethylmethylpyrrolidinium bis(trifluoromethanesulfonyl)amide ([C₂mpyr][NTf₂]) induced by nanosized SiO₂ particles. The addition of the nanoparticles dramatically increases plasticity and ion mobility. Positron annihilation lifetime spectroscopy (PALS) measurements indicate an increase in mean defect size and defect concentration as a result of nanoparticle inclusion. The scaling of the conductivity with size suggests that a “trivial space charge” effect is operable, although a strain induced enhancement of defects (in particular extended defects) is also likely given the observed increase in plasticity.

Investigating nanoparticle-substrate interaction in LSPR biosensing using the image-charge theory

Localized surface plasmon resonance (LSPR) has been used to develop optical biosensors. Tuning the resonance wavelength to detect target biomolecules with a particular dipolar resonance is essential when designing LSPR biosensors. In this paper, the interaction of nanoparticles (NPs) with glass substrate (SiO2) for LSPR wavelength is investigated using the concept of the image-charge theory. Using the FDTD method, it is shown how the NP and substrate size change the plasmon wavelength. Next, this phenomenon is interpreted using the analytical electrostatic eigenvalue method.