Compensation of mode shapes with a piezo electric actuator for an optical drive

In miniaturized systems (e.g. optical disk drives) much effortis made to design a structure in such a way that the demandson dimensions (height, width) and desired bandwidthare satisfied. Easier, and often cheaper designs can not beused, because they suffer from lower resonance frequencies,which limit the bandwidth. A method is presented formechatronic structures that compensates unwanted bandwidthlimiting resonance frequencies with an additionalpiezo electric actuator. Advantage of this method is thatno extra sensor is used and that the contribution of the piezois much easier to tune (when compared to a notch filter),since it is part of the structure. Disadvantage is that thepiezo influences the dynamics of the original system, whichcomplicates the choice of a suitable piezo actuator

Stability of networked control systems with large delays

Abstract — We consider the stabilization problem for Net-worked Control Systems (NCSs) with uncertain, time-varying network-induced delays and a bounded number of subsequent packet dropouts. A discrete-time model, describing a NCS with packet dropouts and time-varying delays, that can be both smaller and larger than the sampling interval, is presented. Based on this NCS model sufficient LMI conditions are pro-posed for the stability analysis and controller synthesis problem for two different controllers, i.e. a feedback controller that depends on both the state and the past control inputs and a state-feedback controller. The applicability of both controllers is compared. Moreover, the stability and controller synthesis LMIs allow for a performance analysis in terms of a lower bound for the transient decay rate of the response. The results are illustrated by application to a typical motion control example. I

Educational online prevention programme (the SPRINT study) has no effect on the number of running-related injuries in recreational runners:a randomised-controlled trial

OBJECTIVES: The aim of this study was to examine the effectiveness of an enhanced online injury prevention programme on the number of running-related injuries (RRIs) in recreational runners. METHODS: We conducted a randomised-controlled trial in runners who registered for running events (distances: 10-42.195 km) in the Netherlands. Adult runners who provided informed consent were randomised into the intervention or control group. Participants in the intervention group received access to the online prevention programme, which included items to prevent RRIs. Participants in the control group followed their regular preparation for the running event. The primary outcome measure was the number of new RRIs from baseline to 1 month after the running event. To determine differences between injury proportions, univariate and multivariate logistic regression analyses were performed. RESULTS: This study included 4050 recreational runners (63.5% males; mean (SD) age: 42.3 (12.1) years) for analyses. During follow-up, 35.5% (95% CI: 33.5 to 37.6) of the participants in the intervention group sustained a new RRI compared with 35.4% (95% CI: 33.3 to 37.5) of the participants in the control group, with no between-group difference (OR: 1.03; 95% CI: 0.90 to 1.17). There was a positive association between the number of items followed in the injury prevention programme and the number of RRIs (OR: 1.05; 95% CI: 1.00 to 1.11). CONCLUSION: The enhanced online injury prevention programme had no effect on the number of RRIs in recreational runners, and being compliant with the programme paradoxically was associated with a slightly higher injury rate. Future studies should focus on individual targeted prevention with emphasis on the timing and application of preventive measures.NL7694

Providing perioperative care for patients with hip fractures

Providing perioperative care for patients with hip fractures can present major challenges for the anaesthesiologist. These patients often have multiple comorbidities, the deterioration of any one of which may have precipitated the fall. A careful balance has to be achieved between minimising the time before operation and spending time to optimise their medical status. This review will present insights into preoperative patient assessment and optimization in this group of patients from the anaesthesiologists’ perspective. In particular, it will highlight important medical issues of concern that may alter anaesthetic risks and management. With a greater understanding of what these issues are, potentially a more prompt and integrated approach to managing these patients may be made. Hopefully, this would result in minimising last minute cancellations due to medical reasons for these patients

Mutations in the nuclear localization sequence of the Aristaless related homeobox; sequestration of mutant ARX with IPO13 disrupts normal subcellular distribution of the transcription factor and retards cell division

The electronic version of this article is the complete one and can be found online at: http://www.pathogeneticsjournal.com/content/3/1/1Background: Aristaless related homeobox (ARX) is a paired-type homeobox gene. ARX function is frequently affected by naturally occurring mutations. Nonsense mutations, polyalanine tract expansions and missense mutations in ARX cause a range of intellectual disability and epilepsy phenotypes with or without additional features including hand dystonia, lissencephaly, autism or dysarthria. Severe malformation phenotypes, such as X-linked lissencephaly with ambiguous genitalia (XLAG), are frequently observed in individuals with protein truncating or missense mutations clustered in the highly conserved paired-type homeodomain. Results: We have identified two novel point mutations in the R379 residue of the ARX homeodomain; c.1135C>A, p.R379S in a patient with infantile spasms and intellectual disability and c.1136G>T, p.R379L in a patient with XLAG. We investigated these and other missense mutations (R332P, R332H, R332C, T333N: associated with XLAG and Proud syndrome) predicted to affect the nuclear localisation sequences (NLS) flanking either end of the ARX homeodomain. The NLS regions are required for correct nuclear import facilitated by Importin 13 (IPO13). We demonstrate that missense mutations in either the N- or C-terminal NLS regions of the homeodomain cause significant disruption to nuclear localisation of the ARX protein in vitro. Surprisingly, none of these mutations abolished the binding of ARX to IPO13. This was confirmed by co-immunoprecipitation and immmuno fluorescence studies. Instead, tagged and endogenous IPO13 remained bound to the mutant ARX proteins, even in the RanGTP rich nuclear environment. We also identify the microtubule protein TUBA1A as a novel interacting protein for ARX and show cells expressing mutant ARX protein accumulate in mitosis, indicating normal cell division may be disrupted. Conclusions: We show that the most likely, common pathogenic mechanism of the missense mutations in NLS regions of the ARX homeodomain is inadequate accumulation and distribution of the ARX transcription factor within the nucleus due to sequestration of ARX with IPO13.Cheryl Shoubridge, May Huey Tan, Tod Fullston, Desiree Cloosterman, David Coman, George McGillivray, Grazia M Mancini, Tjitske Kleefstra and Jozef Géc

Invloed van dagdosering en inhalatiesysteem op therapieontrouw bij astmapatiënten

Contains fulltext : 26124___.PDF (publisher's version ) (Open Access

ARX: a gene for all seasons

The Aristaless-related homeobox gene, ARX, is an important transcription factor with a crucial role in forebrain, pancreas and testes development. At least fifty-nine mutations have been described in the ARX gene in seven X-chromosome linked disorders involving mental retardation. Recent studies with ARX screening suggest that the gene is mutated in 9.5% of X-linked families with these disorders. Two different polyalanine expansion mutations represent 46% of all currently known mutations and show considerable pleiotropy. The ARX gene is emerging as one of the more important disease-causing genes on the X chromosome and ought to be considered for routine screening. Although the normal Arx protein is known to be a bifunctional transcriptional activator and repressor, the complete biochemical characterization of the normal and mutated ARX awaits further investigation. Pax4 was identified as one of the ARX target genes, and both proteins have crucial functions in endocrine mouse pancreas alpha-cell and beta-cell lineage specification