Prosthetic EMG control enhancement through the application of man-machine principles

An area in medicine that appears suitable to man-machine principles is rehabilitation research, particularly when the motor aspects of the body are involved. If one considers the limb, whether functional or not, as the machine, the brain as the controller and the neuromuscular system as the man-machine interface, the human body is reduced to a man-machine system that can benefit from the principles behind such systems. The area of rehabilitation that this paper deals with is that of an arm amputee and his prosthetic device. Reducing this area to its man-machine basics, the problem becomes one of attaining natural multiaxis prosthetic control using Electromyographic activity (EMG) as the means of communication between man and prothesis. In order to use EMG as the communication channel it must be amplified and processed to yield a high information signal suitable for control. The most common processing scheme employed is termed Mean Value Processing. This technique for extracting the useful EMG signal consists of a differential to single ended conversion to the surface activity followed by a rectification and smoothing

Pharmacological interventions other than botulinum toxin for spasticity after stroke.

BACKGROUND: The long-term risk of stroke increases with age, and stroke is a common cause of disability in the community. Spasticity is considered a significantly disabling impairment that develops in people who have had a stroke. The burden of care is higher in stroke survivors who have spasticity when compared with stroke survivors without spasticity with regard to treatment costs, quality of life, and caregiver burden. OBJECTIVES: To assess if pharmacological interventions for spasticity are more effective than no intervention, normal practice, or control at improving function following stroke. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (May 2016), the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 5), MEDLINE (1946 to May 2016), Embase (2008 to May 2016), CINAHL (1982 to May 2016), AMED (1985 to May 2016), and eight further databases and trial registers. In an effort to identify further studies, we undertook handsearches of reference lists and contacted study authors and commercial companies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any systemically acting or locally acting drug versus placebo, control, or comparative drug with the aim of treating spasticity. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the studies for inclusion and extracted the data. We assessed the included studies for both quality and risk of bias. We contacted study authors to request further information when necessary. MAIN RESULTS: We included seven RCTs with a total 403 participants. We found a high risk of bias in all but one RCT. Two of the seven RCTs assessed a systemic drug versus placebo. We pooled data on an indirect measure of spasticity (160 participants) from these two studies but found no significant effect (odds ratio (OR) 1.66, 95% confidence interval (CI) 0.21 to 13.07; I(2) = 85%). We identified a significant risk of adverse events per participant occurring in the treatment group versus placebo group (risk ratio (RR) 1.65, 95% CI 1.12 to 2.42; 160 participants; I(2) = 0%). Only one of these studies used a functional outcome measure, and we found no significant difference between groups.Of the other five studies, two assessed a systemic drug versus another systemic drug, one assessed a systemic drug versus local drug, and the final two assessed a local drug versus another local drug. AUTHORS' CONCLUSIONS: The lack of high-quality RCTs limited our ability to make specific conclusions. Evidence is insufficient to determine if systemic antispasmodics are effective at improving function following stroke

Discovery of progenitor cell signatures by time-series synexpression analysis during Drosophila embryonic cell immortalization

The use of time series profiling to identify groups of functionally related genes (synexpression groups) is a powerful approach for the discovery of gene function. Here we apply this strategy during RasV12 immortalization of Drosophila embryonic cells, a phenomenon not well characterized. Using high-resolution transcriptional time-series datasets, we generated a gene network based on temporal expression profile similarities. This analysis revealed that common immortalized cells are related to adult muscle precursors (AMPs), a stem cell-like population contributing to adult muscles and sharing properties with vertebrate satellite cells. Remarkably, the immortalized cells retained the capacity for myogenic differentiation when treated with the steroid hormone ecdysone. Further, we validated in vivo the transcription factor CG9650, the ortholog of mammalian Bcl11a/b, as a regulator of AMP proliferation predicted by our analysis. Our study demonstrates the power of time series synexpression analysis to characterize Drosophila embryonic progenitor lines and identify stem/progenitor cell regulators

Recent trends in UK insects that inhabit early successional stages of ecosystems

Improved recording of less popular groups, combined with new statistical approaches that compensate for datasets that were hitherto too patchy for quantitative analysis, now make it possible to compare recent trends in the status of UK invertebrates other than butterflies. Using BRC datasets, we analysed changes in status between 1992 and 2012 for those invertebrates whose young stages exploit early seral stages within woodland, lowland heath and semi-natural grassland ecosystems, a habitat type that had declined during the 3 decades previous to 1990 alongside a disproportionally high number of Red Data Book species that were dependent on it. Two clear patterns emerged from a meta-analysis involving 299 classifiable species belonging to ten invertebrate taxa: (i) during the past 2 decades, most early seral species that are living near their northern climatic limits in the UK have increased relative to the more widespread members of these guilds whose distributions were not governed by a need for a warm micro-climate; and (ii) independent of climatic constraints, species that are restricted to the early stages of woodland regeneration have fared considerably less well than those breeding in the early seral stages of grasslands or, especially, heathland. The first trend is consistent with predicted benefits for northern edge-of-range species as a result of climate warming in recent decades. The second is consistent with our new assessment of the availability of early successional stages in these three ecosystems since c. 1990. Whereas the proportion and continuity of early seral patches has greatly increased within most semi-natural grasslands and lowland heaths, thanks respectively to agri-environmental schemes and conservation management, the representation of fresh clearings has continued to dwindle within UK woodlands, whose floors are increasingly shaded and ill-suited for this important guild of invertebrates

Rapid selection for increased dispersal rates by the endangered butterfly Phengaris (Maculinea) arion across restored landscapes

When designing restorations for durable metapopulations of endangered butterflies, it is important to understand how frequently the adults mix between sites and their probability of colonising vacant patches unassisted by human translocations. We analysed 43 examples of natural dispersal by Phengaris arion L. to restored sites in three regions following its reintroduction after extinction to the UK. We compared the years taken to reach restored habitats with the distance from a source colony, the number and density of P. arion on source sites, the size of source sites, the nature of the intervening matrix, summer temperatures, the incidence of drought and whether a more dispersive phenotype has evolved across restored landscapes. Isolation of sites was the most important constraint on the colonisation of new habitats, followed by the number, but not the density, of P. arion on source sites. Emigration was more frequent in warm summers and when the habitat was degraded by drought, but neither factor remained significant in multifactorial analyses. A matrix of woodland between sites was a greater barrier to dispersal than open or mixed terrain, but again insignificant in multifactorial analyses. A more mobile phenotype of P. arion has evolved while it exploited vacant habitat patches during its first 10–12 generations in the UK. Adults now fly twice as far to find new colonies as in the early years. We map the probabilities of linking restored sites with neighbouring populations in three former landscapes in the Cotswold Hills of Gloucestershire, UK

Auditory presentation and synchronization in Adobe Flash and HTML5/JavaScript Web experiments

Substantial recent research has examined the accuracy of presentation durations and response time measurements for visually presented stimuli in Web-based experiments, with a general conclusion that accuracy is acceptable for most kinds of experiments. However, many areas of behavioral research use auditory stimuli instead of, or in addition to, visual stimuli. Much less is known about auditory accuracy using standard Web-based testing procedures. We used a millisecond-accurate Black Box Toolkit to measure the actual durations of auditory stimuli and the synchronization of auditory and visual presentation onsets. We examined the distribution of timings for 100 presentations of auditory and visual stimuli across two computers with difference specs, three commonly used browsers, and code written in either Adobe Flash or JavaScript. We also examined different coding options for attempting to synchronize the auditory and visual onsets. Overall, we found that auditory durations were very consistent, but that the lags between visual and auditory onsets varied substantially across browsers and computer systems

Loss of the Tumor Suppressor Pten Promotes Proliferation of Drosophila melanogaster Cells In Vitro and Gives Rise to Continuous Cell Lines

In vivo analysis of Drosophila melanogaster has enhanced our understanding of many biological processes, notably the mechanisms of heredity and development. While in vivo analysis of mutants has been a strength of the field, analyzing fly cells in culture is valuable for cell biological, biochemical and whole genome approaches in which large numbers of homogeneous cells are required. An efficient genetic method to derive Drosophila cell lines using expression of an oncogenic form of Ras (RasV12) has been developed. Mutations in tumor suppressors, which are known to cause cell hyperproliferation in vivo, could provide another method for generating Drosophila cell lines. Here we screened Drosophila tumor suppressor mutations to test if they promoted cell proliferation in vitro. We generated primary cultures and determined when patches of proliferating cells first emerged. These cells emerged on average at 37 days in wild-type cultures. Using this assay we found that a Pten mutation had a strong effect. Patches of proliferating cells appeared on average at 11 days and the cultures became confluent in about 3 weeks, which is similar to the timeframe for cultures expressing RasV12. Three Pten mutant cell lines were generated and these have now been cultured for between 250 and 630 cell doublings suggesting the life of the mutant cells is likely to be indefinite. We conclude that the use of Pten mutants is a powerful means to derive new Drosophila cell lines