Data-driven control design for neuroprotheses: a virtual reference feedback tuning (VRFT) approach

This paper deals with design of feedback controllers for knee joint movement of paraplegics using functional electrical stimulation (FES) of the paralyzed quadriceps muscle group. The controller design approach, virtual reference feedback tuning (VRFT), is directly based on open loop measured data and fits the controller in such a way that the closed-loop meets a model reference objective. The use of this strategy, avoiding the modeling step, significantly reduces the time required for controller design and considerably simplifies the rehabilitation protocols. Linear and nonlinear controllers have been designed and experimentally tested, preliminarily on a healthy subject and finally on a paraplegic patient. Linear controller is effective when applied on small range of knee joint angle. The design of a nonlinear controller allows better performances. It is also shown that the control design is effective in tracking assigned knee angle trajectories and rejecting disturbances

Tunable supramolecular gel properties by varying thermal history

YesThe possibility of using differential pre‐heating prior to supramolecular gelation to control the balance between hydrogen‐bonding and aromatic stacking interactions in supramolecular gels and obtain consequent systematic regulation of structure and properties is demonstrated. Using a model aromatic peptide amphiphile, Fmoc‐tyrosyl‐leucine (Fmoc‐YL) and a combination of fluorescence, infrared, circular dichroism and NMR spectroscopy, it is shown that the balance of these interactions can be adjusted by temporary exposure to elevated temperatures in the range 313–365 K, followed by supramolecular locking in the gel state by cooling to room temperature. Distinct regimes can be identified regarding the balance between H‐bonding and aromatic stacking interactions, with a transition point at 333 K. Consequently, gels can be obtained with customizable properties, including supramolecular chirality and gel stiffness. The differential supramolecular structures also result in changes in proteolytic stability, highlighting the possibility of obtaining a range of supramolecular architectures from a single molecular structure by simply controlling the pre‐assembly temperature.FP7 Ideas: European Research Council. Grant Number: 25877

From linear to circular economy: The role of BS 8001:2017 for green transition in small business in developing economies

Implementing Circular Economy (CE) strategies has recently become one of the essential strategies for sustainable development and corporate social responsibility. However, despite the promising role and potential benefits of the CE for companies and society, there has still been insufficient analysis examining the challenges for circular transition faced by micro, small, and medium-sized enterprises (MSMEs) and the role that standards, such as British Standard (BS) 8001:2017, play during the transition process from linear to circular economy practices. Given this context and to further increase our understanding of the factors preventing the transition from linear to CE, this study aims to assess the CE implementation in MSMEs in developing economies in light of BS 8001:2017 through a survey with Brazilian MSMEs. The primary findings emphasize that CE practices from the Administration dimension occupied top positions in the ranking of implementation, along with one practice from the Innovation dimension. However, the results show that several practices associated with Transparency and Product Optimization in the value chain held the last level of evidence of implementation. Findings suggest that assessing MSMEs through BS 8001:2017 is beneficial for aiding them in analysing and reconsidering their practices related to the conventional linear business models of take-use-dispose. Collectively, the findings improve our understanding of the level of adoption of CE components implementation, the most and the least adopted practices during the CE transition. The study also provides implications for policy, theory, and practical applications in cases where there is an interest in assessing the maturity of CE implementation within MSMEs in developing economies

Exercise duration-matched interval and continuous sprint cycling induce similar increases in AMPK phosphorylation, PGC-1α and VEGF mRNA expression in trained individuals

Purpose: The effects of low-volume interval and continuous ‘all-out’ cycling, matched for total exercise duration, on mitochondrial and angiogenic cell signalling was investigated in trained individuals. Methods: In a repeated measures design, 8 trained males ((Formula presented.), 57 ± 7 ml kg−1 min−1) performed two cycling exercise protocols; interval (INT, 4 × 30 s maximal sprints interspersed by 4 min passive recovery) or continuous (CON, 2 min continuous maximal sprint). Muscle biopsies were obtained before, immediately after and 3 h post-exercise. Results: Total work was 53 % greater (P = 0.01) in INT compared to CON (71.2 ± 7.3 vs. 46.3 ± 2.7 kJ, respectively). Phosphorylation of AMPKThr172 increased by a similar magnitude (P = 0.347) immediately post INT and CON (1.6 ± 0.2 and 1.3 ± 0.3 fold, respectively; P = 0.011), before returning to resting values at 3 h post-exercise. mRNA expression of PGC-1α (7.1 ± 2.1 vs. 5.5 ± 1.8 fold; P = 0.007), VEGF (3.5 ± 1.2 vs. 4.3 ± 1.8 fold; P = 0.02) and HIF-1α (2.0 ± 0.5 vs. 1.5 ± 0.3 fold; P = 0.04) increased at 3 h post-exercise in response to INT and CON, respectively; the magnitude of which were not different between protocols. Conclusions: Despite differences in total work done, low-volume INT and CON ‘all-out’ cycling, matched for exercise duration, provides a similar stimulus for the induction of mitochondrial and angiogenic cell signalling pathways in trained skeletal muscle

Learning in large learning spaces:the academic engagement of a diverse group of students

Teaching larger groups of students is a growing phenomenon in HE and this brings with it, its own challenges not least for the students themselves but also their lecturers. Demographic factors as well as the experiences that characterise us as individuals will impact upon our ability to learn. The pilot study reported here considered the “academic engagement” of a diverse group of students where their course is delivered in large learning environments. As a pilot study, the paper concludes with the identification of two areas which are worthy of further research. Firstly, the study highlighted that mature students were more likely to engage in learning strategies that are associated with surface learning – the binary opposite to which practitioners often strive to achieve. Secondly, the research suggests that students who appear to know their tutors well indicate a preference for study approaches that are likely to develop deeper learning

Augmenting Music Sheets with Harmonic Fingerprints

Conventional Music Notation (CMN) is the well-established foundation for the written communication of musical information, such as rhythm, harmony, or timbre. However, CMN suffers from the complexity of its visual encoding and the need for extensive training to acquire proficiency and legibility. While alternative notations using additional visual variables (such as color to improve pitch identification) have been proposed, the music community does not readily accept notation systems that vary widely from the CMN. Therefore, to support student musicians in understanding the harmonic relationship of notes, instead of replacing the CMN, we present a visualization technique that augments a digital music sheet with a harmonic fingerprint glyph. Our design exploits the circle of fifths - a fundamental concept in music theory, as a visual metaphor. By attaching these visual glyphs to each bar of a selected composition we provide additional information about the salient harmonic features available in a musical piece. We conducted a user study to analyze the performance of experts and non-experts in an identification and comparison task of recurring patterns. The evaluation shows that the harmonic fingerprint supports these tasks without the need for close-reading, as when compared to a not-annotated music sheet.Comment: (9+1) pages; 5 figures; User Stud

Morphologies of AGN host galaxies using HST/ACS in the CDFS-GOODS field

Using HST/ACS images in four bands F435W, F606W, F775W and F850LP, we identify optical counterparts to the X-ray sources in the Chandra Deep Field South in the GOODS South field. A detailed study has been made of these sources to study their morphological types. We use methods like decomposition of galaxy luminosity profiles, color maps and visual inspection of 192 galaxies which are identified as possible optical counterparts of Chandra X-ray sources in the CDFS-GOODS field. We find that most moderate luminosity AGN hosts are bulge dominated in the redshift range (z \approx 0.4-1.3), but not merging/interacting galaxies. This implies probable fueling of the moderate luminosity AGN by mechanisms other than those merger driven.Comment: pdflatex, accepted in ApSS. revisions in tex

Interesting magnetic properties of Fe1−x_{1-x}Cox_xSi alloys

Solid solution between nonmagnetic narrow gap semiconductor FeSi and diamagnetic semi-metal CoSi gives rise to interesting metallic alloys with long-range helical magnetic ordering, for a wide range of intermediate concentration. We report various interesting magnetic properties of these alloys, including low temperature re-entrant spin-glass like behaviour and a novel inverted magnetic hysteresis loop. Role of Dzyaloshinski-Moriya interaction in the magnetic response of these non-centrosymmetric alloys is discussed.Comment: 11 pages and 3 figure

Pre-treatment minority HIV-1 drug resistance mutations and long term virological outcomes : is prediction possible?

BACKGROUND : Although the use of highly active antiretroviral therapy in HIV positive individuals has proved to be effective in suppressing the virus to below detection limits of commonly used assays, virological failure associated with drug resistance is still a major challenge in some settings. The prevalence and effect of pre-treatment resistance associated variants on virological outcomes may also be underestimated because of reliance on conventional population sequencing data which excludes minority species. We investigated long term virological outcomes and the prevalence and pattern of pre-treatment minority drug resistance mutations in individuals initiating HAART at a local HIV clinic. METHODS : Patient’s records of viral load results and CD4 cell counts from routine treatment monitoring were used and additional pre-treatment blood samples for Sanger sequencing were obtained. A selection of pretreatment samples from individuals who experienced virological failure were evaluated for minority resistance associated mutations to 1 % prevalence and compared to individuals who achieved viral suppression. RESULTS : At least one viral load result after 6 months or more of treatment was available for 65 out of 78 individuals followed for up to 33 months. Twenty (30.8 %) of the 65 individuals had detectable viremia and eight (12.3 %) of them had virological failure (viral load > 1000 RNA copies/ml) after at least 6 months of HAART. Viral suppression, achieved by month 8 to month 13, was followed by low level viremia in 10.8 % of patients and virological failure in one patient after month 20. There was potentially reduced activity to Emtricitabine or Tenofovir in three out of the eight cases in which minority drug resistance associated variants were investigated but detectable viremia occurred in one of these cases while the activity of Efavirenz was generally reduced in all the eight cases. CONCLUSIONS : Early viral suppression was followed by low level viremia for some patients which may be an indication of failure to sustain viral suppression over time. The low level viremia may also be representing early stages of resistance development. The mutation patterns detected in the minority variants showed potential reduced drug sensitivity which highlights their potential to dominate after treatment initiation. TRIAL REGISTRATION : Not applicable.Additional file 1: Figure S1. Deep sequencing coverage. C – E shows sequencing coverage for samples with virologicalfailure (L031, L054 and L064 respectively), F shows coverage for a sample with detectable viremia (L009)and G and H show coverage for virally suppressed samples (L074 and L075 respectively). Mutations wereexcluded from analysis for any of the following: noisy mutations filtering, coverage filtering, forward/ reverse unbalanced frequency and forward/reverse unbalanced coverage.This work is based on the research supported by grants awards from South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation of South Africa (C.T. Tiemessen), the HIV Research Trust (M.L. Mzingwane), the National Health Laboratory Service Research Trust and the Poliomyelitis Research Foundation.http://www.virologyj.comam2016Medical Virolog