6,125 research outputs found
Study of volatile contaminants in reclaimed water
Different methods were evaluated for reducing the volatile contaminants found in water recovered from urine by distillation. The use of activated carbon, addition of potassium permanganate, and the use of oxidation catalyst are described along with laboratory tests. It is concluded that catalytic decomposition appears to be feasible, and further investigation is recommended
Social Enterprise Investment Fund evaluation - phase one: scoping, review and methodology development.
The £100m Social Enterprise Investment Fund (SEIF) aims to stimulate and increase the numbers of Social Enterprises (SEs) that are involved in the delivery of health and social care services via grants, loans and equity investments. The SEIF seeks to generate sufficient returns on its investments to become self-sustaining over the initial fund period (2007-2011).
The evaluation of the SEIF aims to:
- assess the effectiveness of the Fund in supporting SEs;
- identify the impact of the SEIF including some evidence of the types of social benefits produced through the activities of SEs; and
- identify lessons and make recommendations for the future improvement of the SEIF and the role of SEs in the delivery of health and social care services.
The objectives of this component of the research have been to:
- explore stakeholder expectations for SEIF and establish a common view of how the success of SEIF should be measured, and the mechanisms through which the SEIF is expected to achieve its outcomes;
- refine the study design in the light of the programme theories which have surfaced
Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury
Background: Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in
several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1,
a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1
plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS.
Methods: Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were
studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and
bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was
performed on BAL cells.
Results: sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4–
54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of
the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients
(p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than
those without detectable sVEGFR-1 (1415.2 (474.9–3192) pg/ml v 4761 (1349–7596.6) pg/ml, median
difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF
levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased
following incubation with tumour necrosis factor a.
Conclusion: This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with
ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS
Book Reviews
This section contains reviews of Florence Parker Simister’s The Fire’s Center/Rhode Island in the Revolutionary Era, 1763-1790, Edwin S. Gaustad’s George Berkeley in America, Jeffrey R. Redmond’s “Viking” Hoaxes in North America by NHS Staff John F. Millar and Howard Browne
2D-TCAD Simulation on Retention Time of Z2FET for DRAM Application
Traditional memory devices are facing more challenges due to continuous down-scaling. 6T-SRAM suffers from variability [1-2] and reliability [3-4] issues, which introduce cell stability problems. DRAM cells with one transistor, one capacitor (1T1C) struggle to maintain refresh time [5-6]. Efforts have been made to find new memory solutions, such as one transistor (1T) solutions [7-9]. Floating body based memory structures are among the potential candidates, but impact ionization or band-to-band tunnelling (B2BT) limits their refresh time [10]. A recently proposed zero impact ionization and zero subthreshold swing device named Z2FET [9, 11-12] has been demonstrated and is a promising candidate for 1T DRAM memory cell due to technology advantages such as CMOS technology compatibility, novel capacitor-less structure and sharp switching characteristics. In the Z2FET memory operation, refresh frequency is determined by data retention time. Previous research [11-12] is lacking systematic simulation analysis and understanding on the underlying mechanisms. In this paper, we propose a new simulation methodology to accurately extract retention time in Z2FET devices and understand its dependency on applied biases, temperatures and relevant physical mechanisms. Since the stored ‘1’ state in Z2FET is an equilibrium state [9, 11-12] and there is no need to refresh, we will concentrate on state ‘0’ retention. Two types of ‘0’ retention time: HOLD ‘0’ and READ ‘0’ retention time will be discussed separately
Parameter inference in mechanistic models of cellular regulation and signalling pathways using gradient matching
A challenging problem in systems biology is parameter inference in mechanistic models of signalling pathways. In the present article, we investigate an approach based on gradient matching and nonparametric Bayesian modelling with Gaussian processes. We evaluate the method on two biological systems, related to the regulation of PIF4/5 in Arabidopsis thaliana, and the JAK/STAT signal transduction pathway
Stability of trusses by graphic statics.
This paper presents a graphical method for determining the linearized stiffness and stability of prestressed trusses consisting of rigid bars connected at pinned joints and which possess kinematic freedoms. Key to the construction are the rectangular areas which combine the reciprocal form and force diagrams in the unified Maxwell-Minkowski diagram. The area of each such rectangle is the product of the bar tension and the bar length, and this corresponds to the rotational stiffness of the bar that arises due to the axial force that it carries. The prestress stability of any kinematic freedom may then be assessed using a weighted sum of these areas. The method is generalized to describe the out-of-plane stability of two-dimensional trusses, and to describe three-dimensional trusses in general. The paper also gives a graphical representation of the 'product forces' that were introduced by Pellegrino and Calladine to describe the prestress stability of trusses
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