3,122 research outputs found

    The Role of Futureproofing in the Management of Infrastructural Assets

    Get PDF
    Ensuring long-term value from infrastructure is essential for a sustainable economy. In this context, futureproofing involves addressing two broad issues: i. Ensuring the ability of infrastructure to be resilient to unexpected or uncontrollable events e.g. extreme weather events; and ii. Ensuring the ability to adapt to required changes in structure and / or operations of the infrastructure in the future e.g. expansion of capacity, change in usage mode or volumes. Increasingly, in their respective roles, infrastructure designers/builders and owners/operators are being required to develop strategies for futureproofing as part of the life cycle planning for key assets and systems that make up infrastructure. In this paper, we report on a preliminary set of studies aimed at exploring the following issues related to infrastructure / infrastructure systems: • What is intended by the futureproofing of infrastructural assets? • Why and when to futureproof critical infrastructure? • How can infrastructure assets and systems be prepared for uncertain futures? • How can futureproofing be incorporated into asset management practice? In order to seek answers to the above questions, the Cambridge Centre for Smart Infrastructure and Construction (CSIC) has conducted two industrial workshops bringing together leading practitioners in the UK infrastructure and construction sectors, along with government policy makers. This paper provides an initial summary of the findings from the workshops (part presentation, part working sessions), and proposes a simple framework for linking futureproofing into broader asset management considerations. To begin, an overview of futureproofing and motivate the need for futureproofing infrastructure assets is provided. Following this, an approach to futureproofing infrastructure portfolios is presented that organisations in the infrastructure sector can use. Key barriers to futureproofing are also presented before examining the ISO 55001 asset management standard to highlight the interplay between futureproofing and infrastructural asset management. Finally, different ways by which an effective futureproofing strategy can enhance the value of infrastructure are examined

    Exact relativistic beta decay endpoint spectrum

    Get PDF
    The exact relativistic form for the beta decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN collaboration. We also discuss the three neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future beta decay endpoint experiments.Comment: 12 pages, 3 figure

    Two Loop Low Temperature Corrections to Electron Self Energy

    Full text link
    We recalculate the two loop corrections in the background heat bath using real time formalism. The procedure of the integrations of loop momenta with dependence on finite temperature before the momenta without it, has been followed. We determine the mass and wavefunction renormalization constants in the low temperature limit of QED, for the first time with this preferred order of integrations. The correction to electron mass and spinors in this limit is important in the early universe at the time of primordial nucleosynthesis as well as in astrophysics.Comment: 8 pages and 1 figure to appear in Chinese Physics

    (In)finiteness of Spherically Symmetric Static Perfect Fluids

    Full text link
    This work is concerned with the finiteness problem for static, spherically symmetric perfect fluids in both Newtonian Gravity and General Relativity. We derive criteria on the barotropic equation of state guaranteeing that the corresponding perfect fluid solutions possess finite/infinite extent. In the Newtonian case, for the large class of monotonic equations of state, and in General Relativity we improve earlier results

    Scientific validation of cardioprotective attribute by standardized extract of Bombyx mori against doxorubicin-induced cardiotoxicity in murine model

    Get PDF
    Doxorubicin (DOX) is an excellent antineoplastic agent used for the treatment of hematological and solid malignancies. The aqueous extract of Bombyx mori (BMAE) contains amino acids and some flavonoids with obvious cardioprot ective effect. The aim of this study was to investigate the possible protective effect of BMAE against DOX-induced cardiotoxicity and its underlying mechanisms on murine model. The metabolic profiling of BMAE was carried out by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) and the amino acid profiling by HPLC method using fluorescence detector (HPLC-FLD). The biochemical parameter like caspase-3, tumor necrosis factor–alpha (TNF—α), interleukin -6 (IL-6), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) and malondialdehyde (MDA) were studied. Tissue damage was further evaluated by histopathological studies. The metabolic profiling of BMAE exhibited presence of quercetin 7-O-β-D-glucoside, kaempferol7-O-β-D-glucopyranoside, coumaric acid glucoside, 2-hydroxy-nonadecanoic acid and 9,12-dihydroxy stearic acid as important constituents. The amino acid profile by HPLC-FLD showed presence of 17 amino acids. The BMAE showed prominent free radical scavenging activity when assessed by the H2O2 and super-oxide method. The results of present investigation showed protection against DOX-induced oxid ative stress (lipid peroxidation), by reverting activities of apoptotic markers (caspase-3 and TNF-α), cardiac markers (CK-MB and LDH activities) as well as pro-inflammatory marker IL-6 followed by oral administration of BMAE. In addition, results of histopathology also supported well the above results. It was observed that BMAE protects DOX-induced cardiotoxicity by virtue of its antioxidants possibly by flavonoids and amino acids

    Improved PET imaging of uPAR expression using new (64)Cu-labeled cross-bridged peptide ligands:comparative in vitro and in vivo studies

    Get PDF
    The correlation between uPAR expression, cancer cell invasion and metastases is now well-established and has prompted the development of a number of uPAR PET imaging agents, which could potentially identify cancer patients with invasive and metastatic lesions. In the present study, we synthesized and characterized two new cross-bridged (64)Cu-labeled peptide conjugates for PET imaging of uPAR and performed a head-to-head comparison with the corresponding and more conventionally used DOTA conjugate. Based on in-source laser-induced reduction of chelated Cu(II) to Cu(I), we now demonstrate the following ranking with respect to the chemical inertness of their complexed Cu ions: DOTA-AE105 << CB-TE2A-AE105 < CB-TE2A-PA-AE105, which is correlated to their corresponding demetallation rate. No penalty in the uPAR receptor binding affinity of the targeting peptide was encountered by conjugation to either of the macrobicyclic chelators (IC(50) ~ 5-10 nM) and high yields and radiochemical purities (>95%) were achieved in all cases by incubation at 95ºC. In vivo, they display identical tumor uptake after 1h, but differ significantly after 22 hrs, where the DOTA-AE105 uptake remains surprisingly high. Importantly, the more stable of the new uPAR PET tracers, (64)Cu-CB-TE2A-PA-AE105, exhibits a significantly reduced liver uptake compared to (64)Cu-DOTA-AE105 as well as (64)Cu-CB-TE2A-AE105, (p<0.0001), emphasizing that our new in vitro stability measurements by mass spectrometry predicts in vivo stability in mice. Specificity of the best performing ligand, (64)Cu-CB-TE2A-PA-AE105 was finally confirmed in vivo using a non-binding (64)Cu-labeled peptide as control ((64)Cu-CB-TE2A-PA-AE105(mut)). This control PET-tracer revealed significantly reduced tumor uptake (p<0.0001), but identical hepatic uptake compared to its active counterpart ((64)Cu-CB-TE2A-PA-AE105) after 1h. In conclusion, our new approach using in-source laser-induced reduction of Cu(II)-chelated PET-ligands provides useful information, which are predictive for the tracer stability in vivo in mice. Furthermore, the increased stability of our new macrobicyclic (64)Cu-CB-TE2A-PA-AE105 PET ligand is paralleled by an excellent imaging contrast during non-invasive PET scanning of uPAR expression in preclinical mouse cancer models. The translational promises displayed by this PET-tracer for future clinical cancer patient management remains, however, to be investigated

    Stability in Designer Gravity

    Full text link
    We study the stability of designer gravity theories, in which one considers gravity coupled to a tachyonic scalar with anti-de Sitter boundary conditions defined by a smooth function W. We construct Hamiltonian generators of the asymptotic symmetries using the covariant phase space method of Wald et al.and find they differ from the spinor charges except when W=0. The positivity of the spinor charge is used to establish a lower bound on the conserved energy of any solution that satisfies boundary conditions for which WW has a global minimum. A large class of designer gravity theories therefore have a stable ground state, which the AdS/CFT correspondence indicates should be the lowest energy soliton. We make progress towards proving this, by showing that minimum energy solutions are static. The generalization of our results to designer gravity theories in higher dimensions involving several tachyonic scalars is discussed.Comment: 29 page

    Enhanced Polyhydroxybutyrate Production for Long-Term Spaceflight Applications

    Get PDF
    Synthetic biology holds the promise of advancing long term space fight by the production of medicine, food, materials, and energy. One such application of synthetic biology is the production of biomaterials, specifically polyhydroxyalkanoates (PHAs), using purposed organisms such as Escherichia coli. PHAs are a group of biodegradable bioplastics that are produced by a wide variety of naturally occurring microorganisms, mainly as an energy storage intermediate. PHAs have similar melting point to polypropylene and a Youngs modulus close to polystyrene. Due to limited resources and cost of transportation, large-scale extraction of biologically produced products in situ is extremely cumbersome during space flight. To that end, we are developing a secretion systems for exporting PHA from the cell in order to reduce unit operations. PHAs granules deposited inside bacteria are typically associated with proteins bound to the granule surface. Phasin, a granule bound protein, was targeted for type I secretion by fusion with HlyA signal peptide for indirect secretion of PHAs. In order to validate our secretion strategy, a green fluorescent protein (GFP) was tagged to the PHA polymerase enzyme (phaC), this three part gene cassette consists of phaA and phaB and are required for PHA production. Producing PHAs in situ during space flight or planet colonization will enable mission success by providing a valuable source of biomaterials that can have many potential applications thereby reducing resupply requirements. Biologically produced PHAs can be used in additive manufacturing such as three dimensional (3D) printing to create products that can be made on demand during space flight. After exceeding their lifetime, the PHAs could be melted and recycled back to 3D print other products. We will discuss some of our long term goals of this approach
    corecore