5,254 research outputs found
Space based OTV servicing
Space based servicing of an orbit transfer vehicle (OTV) was previously outlined in sufficient detail to arrive at OTV and support system servicing requirements. Needed space station facilities and their functional requirements were identified. The impact of logistics and space serviceable design on the OTV design is detailed herein. RL10 derivative rocket engine inspection task times are enumerated
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An evaluation of the performance of UK real estate forecasters
Given the significance of forecasting in real estate investment decisions, this paper investigates forecast uncertainty and disagreement in real estate market forecasts. It compares the performance of real estate forecasters with non-real estate forecasters. Using the Investment Property Forum (IPF) quarterly survey amongst UK independent real estate forecasters and a similar survey of macro-economic and capital market forecasters, these forecasts are compared with actual performance to assess a number of forecasting issues in the UK over 1999-2004, including forecast error, bias and consensus. The results suggest that both groups are biased, less volatile compared to market returns and inefficient in that forecast errors tend to persist. The strongest finding is that forecasters display the characteristics associated with a consensus indicating herding
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Analysing UK real estate market forecast disagreement
Given the significance of forecasting in real estate investment decisions, this paper investigates forecast uncertainty and disagreement in real estate market forecasts. Using the Investment Property Forum (IPF) quarterly survey amongst UK independent real estate forecasters, these real estate forecasts are compared with actual real estate performance to assess a number of real estate forecasting issues in the UK over 1999-2004, including real estate forecast error, bias and consensus. The results suggest that real estate forecasts are biased, less volatile compared to market returns and inefficient in that forecast errors tend to persist. The strongest finding is that real estate forecasters display the characteristics associated with a consensus indicating herding
From Solution Into the Gas Phase: Studying Protein Hydrogen Exchange and Electrospray Ionization Using Molecular Dynamics Simulation
Here, we apply Molecular Dynamics (MD) simulations to investigate fundamental aspects of structural mass spectrometry (MS). We first examine microscopic phenomena underlying Hydrogen/Deuterium exchange (HDX). HDX interrogates structural dynamics of proteins by measuring the rate of Deuterium uptake into backbone amides. We perform microsecond MD simulations on ubiquitin to investigate this process. We find that HDX protection often cannot be explained by Hâbonding or solvent accessibility considerations. These findings caution against non-critical use of HDX data in structural contexts. We next use MD to examine the Electrospray ionization (ESI) mechanism of proteins. ESI is a soft ionization technique resulting in the production of gaseous protein ions. The mechanism of ion formation from nanometer sized droplets is unclear. We apply a trajectory stitching MD approach to simulate protein-containing nanodroplets, finding that nativelyâfolded proteins remain solvated as droplets shrink. Residual charge carriers remain following desolvation, consistent with Doleâs charged residue model
Experimental infectious pancreatic necrosis infections: propagative or point-source epidemic?
AbstractExperimentally initiated epidemics of infectious pancreatic necrosis in rainbow-trout fry were analyzed using a modification of the standard mathematical model for a simple propagative epidemic. Contrary to expectations, the value of the transmission parameter (ÎČ) was inversely related to initial density of susceptible hosts. This anomaly can be explained if we assume that the experimental epidemics were point-source rather than propagative epidemics. The implications of this conclusion for modeling experimental and natural epidemics are discussed
Insecticide resistance and vector control.
Insecticide resistance has been a problem in all insect groups that serve as vectors of emerging diseases. Although mechanisms by which insecticides become less effective are similar across all vector taxa, each resistance problem is potentially unique and may involve a complex pattern of resistance foci. The main defense against resistance is close surveillance of the susceptibility of vector populations. We describe the mechanisms of insecticide resistance, as well as specific instances of resistance emergence worldwide, and discuss prospects for resistance management and priorities for detection and surveillance
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Explaining deviations from NAV in UK property companies: rationality and sentimentality
One of the most vexing issues for analysts and managers of property companies across Europe has been the existence and persistence of deviations of Net Asset Values of property companies from their market capitalisation. The issue has clear links to similar discounts and premiums in closed-end funds. The closed end fund puzzle is regarded as an important unsolved problem in financial economics undermining theories of market efficiency and the Law of One Price. Consequently, it has generated a huge body of research. Although it can be tempting to focus on the particular inefficiencies of real estate markets in attempting to explain deviations from NAV, the closed end fund discount puzzle indicates that divergences between underlying asset values and market capitalisation are not a âpureâ real estate phenomenon. When examining potential explanations, two recurring factors stand out in the closed end fund literature as often undermining the economic rationale for a discount â the existence of premiums and cross-sectional and periodic fluctuations in the level of discount/premium. These need to be borne in mind when considering potential explanations for real estate markets.
There are two approaches to investigating the discount to net asset value in closed-end funds: the ârationalâ approach and the ânoise traderâ or âsentimentâ approach. The ârationalâ approach hypothesizes the discount to net asset value as being the result of company specific factors relating to such factors as management quality, tax liability and the type of stocks held by the fund. Despite the intuitive appeal of the ârationalâ approach to closed-end fund discounts the studies have not successfully explained the variance in closed-end fund discounts or why the discount to net asset value in closed-end funds varies so much over time. The variation over time in the average sector discount is not only a feature of closed-end funds but also property companies. This paper analyses changes in the deviations from NAV for UK property companies between 2000 and 2003. The paper present a new way to study the phenomenon âcleaningâ the gearing effect by introducing a new way of calculating the discount itself. We call it âungeared discountâ. It is calculated by assuming that a firm issues new equity to repurchase outstanding debt without any variation on asset side. In this way discount does not depend on an accounting effect and the analysis should better explain the effect of other independent variables
Social Entrepreneurship and Impact Investing Report
This report investigates the viability of a range of portfolio interventions designed to leverage new sources of investment finance and to support the growth and investability of new businesses in the Indo-Pacific region, with a particular focus on the development of social enterprises. While some of these interventions are relatively new within the aid sector, others are designed to take a fresh perspective on an existing activity. The report sets out the findings for each of the interventions and while interventions were wide ranging, they all form key components of an entrepreneurâs journey and their ultimate participation in an impact investing marketplace. The study focused on the development of new businesses in the region and considers how early stage enterprises could be funded; how entrepreneurs (and particularly social entrepreneurs) could be incubated and supported to develop their business skills; how new financing structures could be deployed by government to attract more private investment into the sector; and the role of platforms in connecting enterprises and sources of capital in brokering deals
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Private property vehicles: the valuation of interests in limited partnerships
This paper examines the extent to which the valuation of partial interests in private property vehicles should be closely aligned to the valuation of the underlying assets. A sample of vehicle managers and investors replied to a questionnaire on the qualities of private property vehicles relative to direct property investment. Applying the Analytic Hierarchy Process (AHP) technique the relative importance of the various advantages and disadvantages of investment in private property vehicles relative to acquisition of the underlying assets are assessed. The results suggest that the main drivers of the growth of the this sector have been the ability for certain categories of investor to acquire interests in assets that are normally inaccessible due to the amount of specific risk. Additionally, investors have been attracted by the ability to âoutsourceâ asset management in a manner that minimises perceived agency problems. It is concluded that deviations from NAV should be expected given that investment in private property vehicles differs from investment in the underlying assets in terms of liquidity, management structures, lot size, financial structure inter alia. However, reliably appraising the pricing implications of these variations is likely to be extremely difficult due to the lack of secondary market trading and vehicle heterogeneity
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