146 research outputs found
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Construction subcontracts: for what we are about to receive
This paper is from a study on specialist and trade contracting in the construction industry. The research was commissioned by CIRIA and undertaken by the University of Reading in conjunction with Sir Alexander Gibb & Partners Ltd. The purpose of the work was to provide guidance for effective and equitable practice in the management of projects where much of the work is executed, and possibly designed, by specialist and trade contractors (STCs). As part of this study, a preliminary investigation into the nature and origins of specialist contracting was undertaken, in conjunction with a survey of the problems confronting STCs. This paper presents that phase of the project
Influence of Egr-1 in cardiac tissue-derived mesenchymal stem cells in response to glucose variations
Mesenchymal stem cells (MSCs) represent a promising cell population for cell therapy and regenerative medicine applications. However, how variations in glucose are perceived by MSC pool is still unclear. Since, glucose metabolism is cell type and tissue dependent, this must be considered when MSCs are derived from alternative sources such as the heart. The zinc finger transcription factor Egr-1 is an important early response gene, likely to play a key role in the glucose-induced response. Our aim was to investigate how short-term changes in in vitro glucose concentrations affect multipotent cardiac tissue-derived MSCs (cMSCs) in a mouse model of Egr-1 KO (Egr-1-/-). Results showed that loss of Egr-1 does not significantly influence cMSC proliferation. In contrast, responses to glucose variations were observed in wt but not in Egr-1 -/- cMSCs by clonogenic assay. Phenotype analysis by RT-PCR showed that cMSCs Egr-1-/- lost the ability to regulate the glucose transporters GLUT-1 and GLUT-4 and, as expected, the Egr-1 target genes VEGF, TGFβ-1, and p300. Acetylated protein levels of H3 histone were impaired in Egr-1-/- compared to wt cMSCs. We propose that Egr-1 acts as immediate glucose biological sensor in cMSCs after a short period of stimuli, likely inducing epigenetic modifications. © 2014 Daniela Bastianelli et al
Bridging Information Security and Environmental Criminology Research to Better Mitigate Cybercrime
Cybercrime is a complex phenomenon that spans both technical and human
aspects. As such, two disjoint areas have been studying the problem from
separate angles: the information security community and the environmental
criminology one. Despite the large body of work produced by these communities
in the past years, the two research efforts have largely remained disjoint,
with researchers on one side not benefitting from the advancements proposed by
the other. In this paper, we argue that it would be beneficial for the
information security community to look at the theories and systematic
frameworks developed in environmental criminology to develop better mitigations
against cybercrime. To this end, we provide an overview of the research from
environmental criminology and how it has been applied to cybercrime. We then
survey some of the research proposed in the information security domain,
drawing explicit parallels between the proposed mitigations and environmental
criminology theories, and presenting some examples of new mitigations against
cybercrime. Finally, we discuss the concept of cyberplaces and propose a
framework in order to define them. We discuss this as a potential research
direction, taking into account both fields of research, in the hope of
broadening interdisciplinary efforts in cybercrime researc
<i>In vivo</i> laser speckle contrast imaging of microvascular blood perfusion using a chip-on-tip camera
Laser speckle contrast imaging (LSCI) is an important non-invasive capability for real-time imaging for tissue-perfusion assessment. Yet, the size and weight of current clinical standard LSCI instrumentation restricts usage to mainly peripheral skin perfusion. Miniaturization of LSCI could enable hand-held instrumentation to image internal organ/tissue to produce accurate speckle-perfusion maps. We characterized a 1mm 2 chip-on-tip camera for LSCI of blood perfusion in vivo and with a flow model. A dedicated optical setup was built to compare chip-on-tip camera to a high specification reference camera (GS3) for LSCI. We compared LSCI performance using a calibration standard and a flow phantom. Subsequently the camera assessed placenta perfusion in a small animal model. Lastly, a human study was conducted on the perfusion in fingertips of 13-volunteers. We demonstrate that the chip-on-tip camera can perform wide-field, in vivo, LSCI of tissue perfusion with the ability to measure physiological blood flow changes comparable with a standard reference camera.</p
Heterodimerisation between VEGFR-1 and VEGFR-2 and not the homodimers of VEGFR-1 inhibit VEGFR-2 activity
Vascular endothelial growth factor (VEGF) signaling is tightly regulated by specific VEGF receptors (VEGF-R). Recently, we identified heterodimerisation between VEGFR-1 and VEGFR-2 (VEGFR1–2) to regulate VEGFR-2 function. However, both the mechanism of action and the relationship with VEGFR-1 homodimers remain unknown. The current study shows that activation of VEGFR1–2, but not VEGFR-1 homodimers, inhibits VEGFR-2 receptor phosphorylation under VEGF stimulation in human endothelial cells. Furthermore, inhibition of phosphatidylinositol 3-kinase (PI3K) increases VEGFR-2 phosphorylation under VEGF stimulation. More importantly, inhibition of PI3K pathway abolishes the VEGFR1–2 mediated inhibition of VEGFR-2 phosphorylation. We further demonstrate that inhibition of PI3K pathway promotes capillary tube formation. Finally, the inhibition of PI3K abrogates the inhibition of in vitro angiogenesis mediated by VEGFR1–2 heterodimers. These findings demonstrate that VEGFR1–2 heterodimers and not VEGFR-1 homodimers inhibit VEGF-VEGFR-2 signaling by suppressing VEGFR-2 phosphorylation via PI3K pathway
Protocol for a placenta-on-a-chip model using trophoblasts differentiated from human induced pluripotent stem cells
Organ-on-a-chip technology incorporating stem cell techniques represents a promising strategy to improve modeling of human organs. Here, we present a protocol for generating a standardized 3D placenta-on-a-chip model using trophoblast derived from human induced pluripotent stem cells (hiPSCs). We describe steps for seeding hiPSCs into multi-chip OrganoPlate devices and on-chip differentiation into trophoblasts against an extracellular matrix under perfused conditions. We then detail procedures for conducting a functional barrier integrity assay, immunostaining, and collecting protein or RNA for molecular analysis. For complete details on the use and execution of this protocol, please refer to Lermant et al. (2023).</p
Protocol for a placenta-on-a-chip model using trophoblasts differentiated from human induced pluripotent stem cells
Organ-on-a-chip technology incorporating stem cell techniques represents a promising strategy to improve modeling of human organs. Here, we present a protocol for generating a standardized 3D placenta-on-a-chip model using trophoblast derived from human induced pluripotent stem cells (hiPSCs). We describe steps for seeding hiPSCs into multi-chip OrganoPlate devices and on-chip differentiation into trophoblasts against an extracellular matrix under perfused conditions. We then detail procedures for conducting a functional barrier integrity assay, immunostaining, and collecting protein or RNA for molecular analysis. For complete details on the use and execution of this protocol, please refer to Lermant et al. (2023).</p
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