Definitive crystal structure of 1,1'-bis[1,2-dicarba-<i>clos</i>o-dodecaborane(11)]

In the title compound, C4H22B20, the two {1,2-closo-C2B10H11} cages are linked across a centre of inversion with a C—C distance of 1.5339 (11) Å. By careful analysis of the structure, it is established that the non-linking cage C atom is equally disordered over cage vertices 2 and 3

How Do Students Select Courses in a Liberal Arts University in Hong Kong:a Mixed-Methods Study

Undergraduate students need to choose different (elective) courses each term. This study examines the Course Selection (CS) decision by undergraduate students at a liberal arts university in Hong Kong. It suggests the use of Social Cognitive Theory (SCT) with CS. In addition, this study tries to compare the CS decisions of local (Hong Kong) students with those of mainland (Chinese) students. It builds a 5-factor model ((1) degree of concern about assessment methods, (2) instructor-related issues, (3) interest and career effects, (4) demanding courses and (5) weighting of assessments) using factor analysis and found that Factors 1, 2, 3 and 4 are statistically different between local and mainland students. Using qualitative analysis, themes are identified concerning CS (mainland students: (1) prefer an interesting course, but academic results are a prerequisite; (2) prefer certain qualities of the instructor, but this is not a decisive factor; (3) prefer to balance workload and individual assessment rather than conducting group projects; (4) prefer to have daytime classes and no days off; (5) take advice from peers but make their own decisions; and (6) prefer courses not to have SL elements and local students: (1) regard interest as their top priority; (2) prefer certain qualities/skills of the instructor; (3) are neutral regarding workload but prefer certain assessment methods; (4) have no preference regarding class time but wish to have a day off; (5) are minimally influenced by peers; and (6) dislike Service Learning). Two new factors emerged in this study, and they are (1) the day/time of courses and (2) service-learning elements. This study fills the research gap using a mixed-methods approach provides evidence to support the findings from previous studies and gives insights into the field of CS in the undergraduate context

Unimanual and Bimanual Weight Perception of Virtual Objects with a new Multi-finger Haptic Interface

Accurate weight perception is important particularly in tasks where the user has to apply vertical forces to ensure safe landing of a fragile object or precise penetration of a surface with a probe. Moreover, depending on physical properties of objects such as weight and size we may switch between unimanual and bimanual manipulation during a task. Research has shown that bimanual manipulation of real objects results in a misperception of their weight: they tend to feel lighter than similarly heavy objects which are handled with one hand only [8]. Effective simulation of bimanual manipulation with desktop haptic interfaces should be able to replicate this effect of bimanual manipulation on weight perception. Here, we present the MasterFinger-2, a new multi-finger haptic interface allowing bimanual manipulation of virtual objects with precision grip and we conduct weight discrimination experiments to evaluate its capacity to simulate unimanual and bimanual weight. We found that the bimanual ‘lighter’ bias is also observed with the MasterFinger-2 but the sensitivity to changes of virtual weights deteriorated

Metronome-Cued Stepping in Place after Hemiparetic Stroke: Comparison of a One- and Two-Tone Beat

Hemiparetic gait is characterised by temporal asymmetry and variability, and these variables are improved by auditory cueing. Stepping in place incorporates aspects of gait and may be a useful tool for locomotor training. The aim of this pilot study was to investigate the use of a single-tone and dual-tone metronome to cue stepping in place after hemiparetic stroke. Eight participants completed an uncued baseline stepping condition and two cued stepping conditions utilising a single-tone and a dualtone metronome. Step times were determined from force plate data, and asymmetry and variability were calculated for the three conditions. Step time asymmetry was significantly reduced in the single-tone condition compared to baseline, and paretic step time variability was significantly reduced in both cued conditions.The single-tone metronome appeared to be preferred to the dual-tone metronome based on participant feedback.The results of this pilot study suggest that metronome cueing produces similar benefits on stepping in place to previously reported findings in walking. Further research on whether stepping in place to a metronome can be used for locomotor training is needed

Body sway during quiet standing post-stroke: effects of individual and interpersonal light touch

Lightly touching an external reference, whether a fixed point or another person, reliably improves postural stability. In hemiparetic stroke patients, however, the effect of fixed point light touch (LT) on balance is uncertain. Moreover, it is not clear whether stroke patients respond in the same manner as healthy controls to light interpersonal touch (IPT). In the present study, therefore, the effects of LT and IPT on balance were contrasted in older adults with and without chronic hemiparetic stroke. Participants stood with open eyes in comfortable, normal bipedal quiet stance and performed 4 contact conditions in random order: no contact, fingertip LT, active fingertip IPT and passive elbow IPT. Body sway varied in response to the contact condition in both groups. The hemiparetic patients, whose impairment was relatively mild, showed responsiveness to LT and IPT similar to the non-hemiparetic group in terms of proportional sway reduction in the anteroposterior but not in the mediolateral sway direction. This indicates that light touch effects are robust but cannot be generalized from healthy older adults to hemiparetic stroke patients without consideration of moderating functional constraints of the individual and the specific postural context. Future research should include hemiparetic individuals with moderate to severe postural deficits to determine possible limitations of light touch balance support in stroke

Visual cue training to improve walking and turning after stroke:a study protocol for a multi-centre, single blind randomised pilot trial

Visual information comprises one of the most salient sources of information used to control walking and the dependence on vision to maintain dynamic stability increases following a stroke. We hypothesize, therefore, that rehabilitation efforts incorporating visual cues may be effective in triggering recovery and adaptability of gait following stroke. This feasibility trial aims to estimate probable recruitment rate, effect size, treatment adherence and response to gait training with visual cues in contrast to conventional overground walking practice following stroke.Methods/design: A 3-arm, parallel group, multi-centre, single blind, randomised control feasibility trial will compare overground visual cue training (O-VCT), treadmill visual cue training (T-VCT), and usual care (UC). Participants (n = 60) will be randomly assigned to one of three treatments by a central randomisation centre using computer generated tables to allocate treatment groups. The research assessor will remain blind to allocation. Treatment, delivered by physiotherapists, will be twice weekly for 8 weeks at participating outpatient hospital sites for the O-VCT or UC and in a University setting for T-VCT participants.Individuals with gait impairment due to stroke, with restricted community ambulation (gait spee

Modelling single-person and multi-person event-based synchronisation

A linear phase correction model has been shown to accurately reflect the corrective processes involved in synchronising motor actions to an external rhythmic cue. The model originated from studies of finger tapping to an isochronous metronome beat and is based on the time series of asynchronies between the metronome and corresponding finger tap onsets, along with their associated intervals. Over recent years the model has evolved and been applied to more complex scenarios, including phase perturbed cues, tempo variations and, most recently, timing within groups. Here, we review the studies that have contributed to the development of the linear phase correction model and the associated findings related to human timing performance. The review provides a background to the studies examining single-person timing to simple metronome cues. We then further expand on the more complex analyses of motor timing to phase and tempo shifted cues. Finally, recent studies investigating inter-personal synchronisation between groups of two or more individuals are discussed, along with a brief overview on the implications of these studies for social interactions. We conclude with a discussion on future areas of research that will be important for understanding corrective timing processes between people

Moving in time: Bayesian causal inference explains movement coordination to auditory beats.

Many everyday skilled actions depend on moving in time with signals that are embedded in complex auditory streams (e.g. musical performance, dancing or simply holding a conversation). Such behaviour is apparently effortless; however, it is not known how humans combine auditory signals to support movement production and coordination. Here, we test how participants synchronize their movements when there are potentially conflicting auditory targets to guide their actions. Participants tapped their fingers in time with two simultaneously presented metronomes of equal tempo, but differing in phase and temporal regularity. Synchronization therefore depended on integrating the two timing cues into a single-event estimate or treating the cues as independent and thereby selecting one signal over the other. We show that a Bayesian inference process explains the situations in which participants choose to integrate or separate signals, and predicts motor timing errors. Simulations of this causal inference process demonstrate that this model provides a better description of the data than other plausible models. Our findings suggest that humans exploit a Bayesian inference process to control movement timing in situations where the origin of auditory signals needs to be resolved

Reduction-induced facile isomerisation of metallacarboranes:synthesis and crystallographic characterisation of 4-Cp-4,1,2-closo-CoC₂B₉H₁₁

One-electron reduction of 3-Cp-3,1,2-closo-CoC2B9H11 followed by heating to reflux in DME (b.p. 85 °C) induces isomerisation to 4-Cp-4,1,2-closo-CoC2B9H11.</p

Steric <i>versus</i> electronic factors in metallacarborane isomerisation: nickelacarboranes with 3,1,2-, 4,1,2- and 2,1,8-NiC₂B₉ architectures and pendant carborane groups, derived from 1,1′-bis(o-carborane)

Nickelacarborane derivatives of 1,1′-bis(o-carborane) allow comment on the factors important in the isomerisation of metallacarboranes.</p