169 research outputs found

    Comments on ‘output feedback adaptive command following and disturbance rejection for nonminimum phase uncertain dynamical systems’

    Full text link
    We provide numerical examples and analysis to show that the adaptive controller given by Theorem 3.1 of Yucelen et al. 1 may fail to stabilize plants under the stated conditions. Copyright © 2011 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83465/1/1235_ftp.pd

    Role of the small GTPase Rab7 in the late endocytic pathway.

    Get PDF
    Rab7 is a small GTPase localized to the late endosomal compartment. Its function was investigated by overexpressing dominant negative or constitutively active mutants in BHK-21 cells. The effects of such overexpression on the internalization and/or degradation of different endocytic markers and on the morphology of the late endosomal compartment were analyzed. We observed a marked inhibition of the degradation of 125I-low density lipoproteins in cells transfected with the Rab7 dominant negative mutants while the rate of internalization was not affected. Moreover in these cells there was an accumulation of many small vesicles scattered throughout the cytoplasm. In contrast, overexpression of the activating mutants led to the appearance of atypically large endocytic structures and caused a dramatic change in the distribution of the cation-independent mannose 6-phosphate receptor. Our data indicate that the Rab7 protein in mammalian cells is present on a late endosomal compartment much larger than the compartment labeled by the cation-independent mannose 6-phosphate receptor. Rab7 also appears to play a fundamental role in controlling late endocytic membrane traffic

    Retrospective Cost Adaptive Flow Control Using a Dielectric Barrier Discharge Actuator

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76651/1/AIAA-2009-5857-706.pd

    Prevalence of obesity and obesity-associated muscle wasting in patients on peritoneal dialysis

    Get PDF
    Background and aims: A progressive decrease in muscle mass until full-blown sarcopenia may occur in patients on peritoneal dialysis (PD) and worsen their life quality and expectancy. Here we investigate the prevalence of obesity and obesity-associated muscle wasting in PD patients. Patients and methods: The study design was observational, cross sectional. Body composition was assessed with BIA and BIVA in 88 PD patients (53.4 ± 13.1 years; 67% male). Patients with obesity and/or with reduced muscle mass were identified using FMI and SM/BW cutoff values, respectively. Inflammatory status was assessed by measuring CRP and fibrinogen blood levels. Results: A total of 44.3% of the patients showed a reduced muscle mass (37.5% moderate and 6.8% severe). The prevalence of obesity was 6.1%, 81.8%, and 100% in patients with normal, moderately, and severely reduced muscle mass, respectively (p < 0.05). Of the total, 15.2% of the patients with normal muscle mass, 18.4% of those with moderately reduced muscle mass, and 66.7% of those with severely reduced muscle mass had diabetes. The prevalence of severe muscle mass loss was higher in those with diabetes than in those without diabetes (22.2% vs. 2.8%, p < 0.05). Patients with obesity-associated muscle wasting showed higher fibrinogen (613.9 ± 155.1 vs. 512.9 ± 159.5 mg/dL, p < 0.05) and CPR (1.4 ± 1.3 vs. 0.6 ± 0.8 mg/dL, p < 0.05) blood concentrations than those with normal body composition. Conclusion: Obesity and diabetes were strongly associated with muscle mass loss in our PD patients. It remains to be established whether prevention of obesity with nutritional interventions can halt the occurrence of muscle mass loss in patients on PD

    Identification of sarcopenia and dynapenia in CKD predialysis patients with EGWSOP2 criteria: An observational, cross-sectional study

    Get PDF
    Objectives: Using the new European Working Group on Sarcopenia in Older People (EWGSOP2) criteria, we identified sarcopenic and dynapenic patients in a cohort of predialysis patients with chronic kidney disease (CKD), and evaluated their clinical and laboratory characteristics. Methods: The study population consisted of 85 (55 men) clinically stable predialysis CKD patients (92.9% in stages 3–5), with a median age of 65.0 (52.5–72.0) y. We classified as sarcopenic the patients with handgrip strength (HGS) and muscle mass both lower than the respective EWGSOP2 cutoff values and as dynapenic those in whom only HGS was less than these reference values. HGS was measured with a hand dynamometer, whereas muscle mass was measured by bioimpedance analysis. Renal function was evaluated as Modification of Diet in Renal Disease estimated glomerular filtration rate. Results: The prevalence of sarcopenia and dynapenia was, respectively, 7.1% and 17.6%. As reported in previous studies, serum albumin and hemoglobin were lower in sarcopenic patients than in patients with preserved muscle mass and strength. However, unlike in these studies, sarcopenia prevalence did not increase with CKD stage, and estimated glomerular filtration rate was similar between groups. Moreover, no difference was identified in any of the aforementioned parameters between dynapenic patients and patients with preserved muscle mass and strength. Conclusions: The EWGSOP2 criteria identified sarcopenia in CKD with a prevalence similar to previous diagnostic criteria. In addition, they found that dynapenia was highly prevalent. Nevertheless, the EWGSOP2 criteria could be better adapted to CKD patients to improve their ability to detect high-risk sarcopenic and dynapenic patients

    Patient engagement with antibiotic messaging in secondary care: a qualitative feasibility study of the ‘review & revise’ experience

    Get PDF
    Background: We aimed to investigate and optimise the acceptability and usefulness of a patient leaflet about antibiotic prescribing decisions made during hospitalisation, and to explore individual patient experiences and preferences regarding the process of antibiotic prescription ‘review & revise’ which is a key strategy to minimise antibiotic overuse in hospitals. Methods: In this qualitative study, run within the feasibility study of a large, cluster-randomised stepped wedge trial of 36 hospital organisations, a series of semi-structured, think-aloud telephone interviews were conducted and data were analysed using thematic analysis. Fifteen adult patients who had experienced a recent acute medical hospital admission during which they had been prescribed antimicrobials and offered a patient leaflet about antibiotic prescribing were recruited to the study. Results: Participants reacted positively to the leaflet, reporting that it was both an accessible and important source of information which struck the appropriate balance between informing and reassuring. Participants all valued open communication with clinicians, and were keen to be involved in antibiotic prescribing decisions, with individuals reporting positive experiences regarding antibiotic prescription changes or stopping. Many participants had prior experience or knowledge of antibiotics and resistance, and generally welcomed efforts to reduce antibiotic usage. Overall, there was a feeling that healthcare professionals (HCPs) are trusted experts providing the most appropriate treatment for individual patient conditions. Conclusions: This study offers novel insights into how patients within secondary care are likely to respond to messages advocating a reduction in the use of antibiotics through the ‘review & revise’ approach. Due to the level of trust that patients place in their care provider, encouraging HCPs within secondary care to engage patients with greater communication and information provision could provide great advantages in the drive to reduce antibiotic use. It may also be beneficial for HCPs to view patient experiences as cumulative events that have the potential to impact future behaviour around antibiotic use. Finally, pre-testing messages about antibiotic prescribing and resistance is vital to dispelling any misconceptions either around effectiveness of treatment for patients, or perceptions of how messages may be received

    Using citizen science to understand floating plastic debris distribution and abundance: A case study from the North Cornish coast (United Kingdom)

    Get PDF
    This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.Citizen science is now commonly employed to collect data on plastic pollution and is recognised as a valuable tool for furthering our understanding of the issue. Few studies, however, use citizen science to gather information on water-borne plastic debris. Here, citizen scientists adopted a globally standardised methodology to sample the sea-surface for small (1-5 mm) floating plastic debris off the Cornish coast (UK). Twenty-eight trawls were conducted along five routes, intersecting two Marine Protected Areas. Of the 509 putative plastic items, fragments were most common (64%), then line (19%), foam (7%), film (6%), and pellets (4%). Fourier-transform infrared spectroscopy identified the most common polymer type as polyethylene (31%), then nylon (12%), polypropylene (8 %), polyamide (5%) and polystyrene (3%). This study provides the first globally comparative baseline of floating plastic debris for the region (mean: 8512 items km−2), whilst contributing to an international dataset aimed at understanding plastic abundance and distribution worldwide.Polzeath Marine Conservation GroupSt Agnes Marine Conservation GroupNewquay Sea Safaris and FishingEngineering and Physical Sciences Research Council (EPSRC)Natural Environment Research Council (NERC
    • …
    corecore