3,260 research outputs found
Surface electrical properties experiment, part 1
The work is reported which was performed on the Surface Electrical Properties Experiment Data Acquisition System. Areas discussed include: data handling and processing, installation and external signal application, operation of the equipment, and digital output. Detailed circuit descriptions are included
The selective cytotoxicity of the alkenyl glucosinolate hydrolysis products and their presence in Brassica vegetables.
© 2015 Elsevier Ireland Ltd.Cruciferous vegetable consumption correlates with reduced risk of cancer. This chemopreventative activity may involve glucosinolates and their hydrolysis products. Glucosinolate-derived isothiocyanates have been studied for their toxicity and chemopreventative properties, but other hydrolysis products (epithionitriles and nitriles) have not been thoroughly examined. We report that these hydrolysis products differ in their cytotoxicity to human cells, with toxicity most strongly associated with isothiocyanates rather than epithionitriles and nitriles. We explored mechanisms of this differential cytotoxicity by examining the role of oxidative metabolism, oxidative stress, mitochondrial permeability, reduced glutathione levels, cell cycle arrest and apoptosis. 2-Propenylisothiocyanate and 3-butenylisothiocyanate both inhibited cytochome P450 1A (CYP1A) enzyme activity in CYP expressing MCL-5 cells at high cytotoxic doses. Incubation of MCL-5 cells with non-cytotoxic doses of 2-propenylisothiocyanate for 24. h resulted in a dose-dependent inhibition of ethoxyresorufin O-deethylase, yet failed to affect CYP1A1 mRNA expression indicating interference with enzyme activity rather than inhibition of transcription. Increased reactive oxygen species (ROS) production was observed only for 2-propenylisothiocyanate treatment. 2-Propenylisothiocyanate treatment lowered reduced glutathione levels whereas no changes were noted with 3,4-epithiobutylnitrile. Cell cycle analysis showed that 2-propenylisothiocyanate induced a G2/M block whereas other hydrolysis products showed only marginal effects. We found that 2-propenylisothiocyanate and 3-butenylisothiocyanate induced cell death predominantly via necrosis whereas, 3,4-epithiobutylnitrile promoted both necrosis and apoptosis. Thus the activity of glucosinolate hydrolysis products includes cytotoxicity that is compound-class specific and may contribute to their putative chemoprotection properties
Input shaping for PFC: how and why?
Predictive functional control (PFC) is a highly successful strategy within industry, but for cases with challenging dynamics the most effective tuning approaches are still an active research area. This paper shows how one can deploy some insights from the more traditional model predictive control literature in order to enable systematic tuning and in particular, to ensure that the key PFC tuning parameter, that is the desired closed-loop time constant, is effective. In addition to enabling easier and more effective tuning, the proposed approach has the advantage of being simple to code and thus retaining the simplicity of implementation and tuning that is a key selling point of PFC. This paper focuses on design for open-loop unstable and also processes with significant under-damping in their open-loop behaviour
An Alternative for PID control: Predictive Functional Control - A Tutorial
PFC (Predictive Function Control) can be considered as a bridge between PI(D) and complex MPC. PI(D) control can have problems handling dead time and constraints. PFC handles these cases and is often better than using a Smith predictor. PFC is a simple realizable MPC which thus uses prediction and preview of key variables. PFC can be implemented via simple program code and thus has cheap license costs. The tutorial introduces the basic idea of PFC and algorithms for typical processes. Simulations illustrate its effectiveness and advantages over PI(D) and Smith predictors
Making the most of housing and growth in the East Midlands: a report on removing the barriers to low public investment in the region
The Smith Institute, in association with the Economic Strategy Research Bureau at Nottingham Business School, has undertaken an investigation into the lack of central government investment in the East Midlands in housing and physical regeneration. The work has been based on desk research, two round tables with stakeholders (in Nottingham and Melton Mowbray) and interviews with over 30 decision makers, experts and opinion formers from across the region. The objectives of the report were: first, to quantify the reduction in central government investment in the region compared with other regions; second, to suggest reasons why this might have
occurred; third, to consider the impact that this might be having on the implementation of government policies such as housing provision, “rebalancing” the economy and achieving greater value for money for government investment. The report concludes with a number of recommendations for local enterprise partnerships
(LEPs), local authorities, the housing sector and central
government
Working in partnership with vulnerable families: The experience of child and family health practitioners
Family circumstances in infancy are persistent and powerful determinants of children's physical and mental health, influencing inequalities that trace from childhood through to adulthood. While the social factors that perpetuate patterns of inequality are more complex than can be addressed through single interventions, child and family health (CFH) services represent crucial sites where trajectories of inequality can be disrupted. In particular, approaches that foster opportunities for practitionerparent engagement that challenge traditional hierarchical health care practice, such as the Family Partnership Model (FPM), are recommended as ways of addressing disadvantage. Little is known about how practitioners implement models of working in partnership with families and, consequently, there is a gap in understanding how best to develop and sustain these new CFH practices. This paper reports a research project that investigated the experiences of 25 health professionals working within a FPM framework with vulnerable families. Through discussion of four key themes redefining expertise, changing practices, establishing new relationships with parents and the complexities of partnership practice the paper offers first-hand accounts of reframing practices that recognise the needs, skills and expertise of parents and thus contribute to empowerment of families. © 2011 La Trobe University
Ground-based detection of sodium in the transmission spectrum of exoplanet HD209458b
[Context] The first detection of an atmosphere around an extrasolar planet
was presented by Charbonneau and collaborators in 2002. In the optical
transmission spectrum of the transiting exoplanet HD209458b, an absorption
signal from sodium was measured at a level of 0.023+-0.006%, using the STIS
spectrograph on the Hubble Space Telescope. Despite several attempts, so far
only upper limits to the Na D absorption have been obtained using telescopes
from the ground, and the HST result has yet to be confirmed.
[Aims] The aims of this paper are to re-analyse data taken with the High
Dispersion Spectrograph on the Subaru telescope, to correct for systematic
effects dominating the data quality, and to improve on previous results
presented in the literature.
[Methods] The data reduction process was altered in several places, most
importantly allowing for small shifts in the wavelength solution. The relative
depth of all lines in the spectra, including the two sodium D lines, are found
to correlate strongly with the continuum count level in the spectra. These
variations are attributed to non-linearity effects in the CCDs. After removal
of this empirical relation the uncertainties in the line depths are only a
fraction above that expected from photon statistics.
[Results] The sodium absorption due to the planet's atmosphere is detected at
>5 sigma, at a level of 0.056+-0.007% (2x3.0 Ang band), 0.070+-0.011% (2x1.5
Ang band), and 0.135+-0.017% (2x0.75 Ang band). There is no evidence that the
planetary absorption signal is shifted with respect to the stellar absorption,
as recently claimed for HD189733b. The measurements in the two most narrow
bands indicate that some signal is being resolved.[abridged]Comment: Latex, 7 pages: accepted for publication in Astronomy & Astrophysic
Reliability and Physiological Interpretation of Pulmonary Gas Exchange by "Circulatory Equivalents" in Chronic Heart Failure
Peak ratios of pulmonary gas-exchange to ventilation during exercise (V˙O2/V˙E and V˙CO2/V˙E, termed "circulatory equivalents") are sensitive to heart failure (HF) severity, likely reflecting low and/or poorly distributed pulmonary perfusion. We tested whether peak V˙O2/V˙E and V˙CO2/V˙E would: (1) distinguish HF patients from controls; (2) be independent of incremental exercise protocol; and (3) correlate with lactate threshold (LT) and ventilatory compensation point (VCP), respectively.Twenty-four HF patients (61±11 years) with reduced ejection fraction (31±8%) and 11 controls (63±7 years) performed ramp-incremental cycle ergometry. Eighteen HF patients also performed slow (5±1 W/min), medium (9±4 W/min), and fast (19±6 W/min) ramps. Peak V˙O2/V˙E and V˙CO2/V˙E from X-Y plot, and LT and VCP from 9-panel plot, were determined by 2 independent, blinded, assessors. Peak V˙O2/V˙E (31.2±4.4 versus 41.8±4.8 mL/L; P<0.0001) and V˙CO2/V˙E (29.3±3.0 versus 36.9±4.0 mL/L; P<0.0001) were lower in HF than controls. Within individuals, there was no difference across 3 ramp rates in peak V˙O2/V˙E (P=0.62) or V˙CO2/V˙E (P=0.97). Coefficient of variation (CV) in peak V˙O2/V˙E was lower than for LT (5.1±2.1% versus 8.2±3.7%; P=0.014), and coefficient of variation in peak V˙CO2/V˙E was lower than for VCP (3.3±1.8% versus 8.7±4.2%; P<0.001). In all participants, peak V˙O2/V˙E was correlated with, but occurred earlier than, LT (r2=0.94; mean bias, -0.11 L/min), and peak V˙CO2/V˙E was correlated with, but occurred earlier than, VCP (r2=0.98; mean bias -0.08 L/min).Peak circulatory equivalents during exercise are strongly associated with (but not identical to) LT and VCP. Peak circulatory equivalents are reliable, objective, effort-independent indices of gas-exchange abnormality in HF
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