The Implications for Regional Investment of Diversification Strategies in Commercial Real Estate Portfolios

A number of studies have examined the benefits of regional diversification strategies within commercial real estate portfolios with two approaches adopted; the first is based on primary contiguous geographical regions while the second employs areas based on economic function. In general, the conclusion is that diversifications strategies based on simple geographical areas adds little, if anything, while economic based regions have shown much greater potential. The economic regions approach to portfolio analysis appears to be a much more valuable tool in evaluating regional real estate investment opportunities and risks. The reason is that this method allows consistent risk measurement between aerial units and enables the portfolio manager to develop a geographically diversified portfolio through the use of economically cohesive regions. The aim of this paper is therefore to identify how the application of these portfolio investment techniques determines the flows of funds coming into regions, and the consequent impacts on regional investment in the regional built environment. Most previous research on this issue is based in the US with studies in other countries largely hampered by lack of real estate data and/or acceptable definitions of economic regions. This study therefore attempts to rectify this position in the UK using a large data set of real estate and socio-economic data.

Minimal conductivity in bilayer graphene

Using the Landauer formula approach, it is proven that minimal conductivity of order of $e^{2}/h$ found experimentally in bilayer graphene is its intrinsic property. For the case of ideal crystals, the conductivity turns our to be equal to $e^{2}/2h$ per valley per spin. A zero-temperature shot noise in bilayer graphene is considered and the Fano factor is calculated. Its value $1-2/\pi$ is close to the value 1/3 found earlier for the single-layer graphene.Comment: 3 pages, 1 figur

Weak localisation in bilayer graphene

We have performed the first experimental investigation of quantum interference corrections to the conductivity of a bilayer graphene structure. A negative magnetoresistance - a signature of weak localisation - is observed at different carrier densities, including the electro-neutrality region. It is very different, however, from the weak localisation in conventional two-dimensional systems. We show that it is controlled not only by the dephasing time, but also by different elastic processes that break the effective time-reversal symmetry and provide invervalley scattering.Comment: 4 pages, 4 figures (to be published in PRL

Zitterbewegung, chirality, and minimal conductivity in graphene

It has been recently demonstrated experimentally that graphene, or single-layer carbon, is a gapless semiconductor with massless Dirac energy spectrum. A finite conductivity per channel of order of $e^{2}/h$ in the limit of zero temperature and zero charge carrier density is one of the striking features of this system. Here we analyze this peculiarity based on the Kubo and Landauer formulas. The appearance of a finite conductivity without scattering is shown to be a characteristic property of Dirac chiral fermions in two dimensions.Comment: final version; 4 pages, 1 eps figur

Applying the mesolens to microbiology : visualising biofilm architecture and substructure

Biofilms pose a public health risk due to their ability to protect bacteria from mechanical, environmental and chemical factors. Thereby they can confer resistance to their constituent bacteria and serve as a vehicle for spread of antimicrobial resistance [1]. Understanding the structure of bacterial communities is critical to developing novel methods of biofilm eradication. Current techniques for imaging live biofilms are limited by sacrificing the size of the imaging volume or spatial resolution. Common approaches to imaging biofilm architecture include electron microscopy techniques [2], single or multi-photon confocal microscopy [3] or wide field epi-fluorescence microscopy using low-magnification, low-numerical aperture lenses [4]. Here we use the Mesolens, an optical microscope with a unique combination of a low magnification (x4) and a high numerical aperture (0.47) which can image specimens up to 6x6x3 mm in volume with a lateral resolution of 700 nm and an axial resolution of 7 μm [5]. Using the Mesolens, it is possible to image whole live colony biofilms with cellular resolution in a single dataset. We report the finding of intra-colony channels (measuring ca.15 μm in diameter) which form when Escherichia coli colonies are grown on a solid surface as an inherent property of biofilm formation. By tracking the movement of 200 nm fluorescent microspheres, we observe translocation of the microspheres from the base of the biofilm into the colony with specific localisation to the channel systems. The uptake of microspheres by the colony, infers that these features are inherent to biofilm formation and provide a role in structural support. The biofilms in this work were grown on a nutrient-rich solid medium, and by expanding from the observations of our bead uptake assay we can deduce that the channels may also play a role in nutrient uptake and dissemination throughout the colony. These findings serve as evidence of a fundamental principle of structural biology and bacterial organisation

Increased expression of IL-16 in the brain of experimental autoimmune encephalomyelitis

Multiple Sclerosis (MS) is a demyelinating disease of the CNS, whose pathophysiology involves both inflammatory and neurodegenerative components. CD4+ T cells are one of the key mediators of disease initiation and progression; however CD4 i s also the receptor for the pro-inflammatory cytokine, interleukin - 16 (IL - 16). IL - 16 has been proposed to play a role in several autoimmune diseases, but the exact role of IL - 16 in the CNS during MS initiation and progression remains unclear. Therefore, the aim of this study was to examine the expression and distribution of IL - 16 in CNS tissue and investigate whether expression levels correlate with neuro-inflammation in experimental autoimmune encephalomyelitis (EAE), a murine model of MS. EAE was induced in 6 week old C 57BL/6J female mice by immunisation with MOG35 - 55 peptide and adjuvants. Tissue was harvested at onset (day 11), peak (day 16) and resolution (day 26), and immunofluorescence staining carried out to determine CD45, CD4 and IL - 16 expression and localisation in the brain of both control and EAE mice. In addition, co-localisation of IL - 16 with CNS and immune cell subtypes was performed using a Mesolens microscope (McConnell et al., 2016), which allows subcellular detail to be obtained from wide - field epifluorescence images. Expression of IL - 16 and CD4 was observed primarily within the lesions of cerebellum and hippocampus of the EAE brain, whereas little expression was observed in control brains. IL - 16 expression was highest at onset with 76 ±2.8% of cells ( n=3) within these lesions expressing IL - 16. This was reduced to 48±2.4% (n=3) at peak and 16 ±1.3% at resolution (n=3). Co-localization studies revealed that IL - 16 was expressed primarily by infiltrating immune cells but not by neurons or astrocytes. Co-localization of IL - 16 with immune cells in brain lesions of EAE mice suggests that infiltrating immune cells are the primary source of IL - 16. Further investigation is required if IL - 16 is pro-inflammatory or anti-inflammatory in the CNS during EAE

Contact resistance in graphene-based devices

We report a systematic study of the contact resistance present at the interface between a metal (Ti) and graphene layers of different, known thickness. By comparing devices fabricated on 11 graphene flakes we demonstrate that the contact resistance is quantitatively the same for single-, bi-, and tri-layer graphene ($\sim800 \pm 200 \Omega \mu m$), and is in all cases independent of gate voltage and temperature. We argue that the observed behavior is due to charge transfer from the metal, causing the Fermi level in the graphene region under the contacts to shift far away from the charge neutrality point