Is It Time For An Exchange Traded Futures Contract Based On A Housing Price Index?

There is not a good hedging instrument to absorb housing price risk. An exchange traded futures contract based on a hedonic or repeat sale housing price index would help homeowners, originators, home builders, and others hedge housing price risk, but it does not exist, yet. We discuss the need and why it may be time for its introduction

Density functional theory of freezing for hexagonal symmetry: Comparison with Landau theory

This is the publisher's version, also available electronically from http://scitation.aip.org/content/aip/journal/jcp/88/6/10.1063/1.453839.Density functional theory, studied recently by us [J. Chem. Phys. 8 7, 5449 (1987)] is used to study the freezing of hard disks and hard spheres into crystals with hexagonal symmetry. Two different numerical techniques are used, namely a Gaussian approximation to the crystal density and a more general Fourier expansion of the crystal density. The results from these methods are compared with each other, more approximate versions of density functional theory, and computer simulations. In addition, we compare density functional theory with Landau theories of first order transitions, in which the free energy is expanded as a power series, usually in just one order parameter. We find that traditional Landau theory has little validity when applied to the freezing transition

Density functional theory of freezing: Analysis of crystal density

This is the publisher's version, also available electronically from http://scitation.aip.org/content/aip/journal/jcp/87/9/10.1063/1.453663The density functional theory of freezing is used to study the liquid to crystal phase transition in the hardsphere and Lennard‐Jones systems. An important step in the calculation is the parametrization of the solid phase average single particle density ρ(r). In this work two popular parametrizations are compared. The first method is a general Fourier decomposition of the periodic solid density in which the amplitude of each (non‐symmetry‐related) Fourier component is treated as an independent parameter. The second parametrization, which is more restrictive but easier to implement, approximates the solid density as a sum of Gaussian peaks centered at the sites of a periodic lattice. The two methods give essentially identical results for the phase diagrams for the two systems studied, but the crystal density predicted by the Fourier method exhibits significant anisotropies which are excluded from the Gaussian representation by construction

Density Functional Theory of Simple Polymers in a Slit Pore: 2. The Role of Compressibility and Field Type

Simple tangent, hard site chains near a hard wall are modeled with a Density Functional (DF) theory that uses the direct correlation function, c(r), as its ''input''. Two aspects of this DF theory are focused upon: (1) the consequences of variations in c(r)'s detailed form; and (2) the correct way to introduce c(r) into the DF formalism. The most important aspect of c(r) is found to be its integrated value, {cflx c}(0). Indeed, it appears that, for fixed {cflx c}(0), all reasonable guesses of the detailed shape of c(r) result in surprisingly similar density distributions, {rho}(r). Of course, the more accurate the c(r), the better the {rho}(r). As long as the length scale introduced by c(r) is roughly the hard site diameter and as long as the solution remains liquid-like, the {rho}(r) is found to be in good agreement with simulation results. The c(r) is used in DF theory to calculate the medium-induced-potential, U{sub M}(r) from the density distribution, {rho}(r). The form of U{sub M}(r) can be chosen to be one of a number of different forms. It is found that the forms for U{sub M}(r), which yield the most accurate results for the wall problem, are also those which were suggested as accurate in previous, related studies

The diffusion of simple penetrants in tangent site polymer melts

The diffusive behavior of penetrants in simple polymer melts was investigated by molecular dynamics simulation. For the case where the polymer melt consisted of pearl-necklace chains, the diffusive behavior of the loose pearl penetrants was seen to be qualitatively different than would be expected in realistic models of polymer melts. In particular, there was little or no ''non-Fickiano'' region; the variation of the diffusion coefficient with the penetrant diameter was what one would expect for diffusion through small molecular liquids; and, finally, the long time tail of the velocity auto correlation displayed a ''-3/2'' power law form, also as in the small molecular liquid case. When the chains' backbone motion was further constrained by the introduction of a bond angle potential, the qualitative nature of the penetrant diffusion became more ''polymer-like''. A non-Fickian region developed; the diffusion coefficient varied more rapidly with penetrant diameter; and the velocity autocorrelation function developed a ''-5/2'' power law tail as would be expected for the diffusion of particles with a wide distribution of trapping times

The Intestinal Microbiota Contributes to the Ability of Helminths to Modulate Allergic Inflammation

We thank Manuel Kulagin for technical help, Pierre Bonnaventure for portal vein blood sampling, Francisco Sepulveda for technical assistance in GS-MS acquisition, and Dorothee Hahne (Metabolomics Australia, University of Western Australia) for human samples SCFA isolation, acquisition, and analysis. We also thank Cristina Cartoni (Phenotyping Unit, EPFL) for Milliplex analysis, Jessica Dessimoz and her team from the Histology Core Facility (EPFL), Miguel Garcia and his team from the Flow Cytometry Core Facility (EPFL), and staff from the EPFL CPG animal house for excellent animal care. The computations were partially performed at the Vital-IT Center for high-performance computing of the SIB Swiss Institute of Bioinformatics (http://www.vital-it.ch). The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. 310948. Funding for A.W.W. and a subset of the 16S rRNA gene sequencing was provided by the Wellcome Trust (grant number WT 098051). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Comparative phenomics: a new approach to study heterochrony

Understanding the links between development and evolution is one of the major challenges of biology. ‘Heterochronies’, evolutionary alterations in the timings of development are posited as a key mechanism of evolutionary change, but their quantification requires gross simplification of organismal development. Consequently, how changes in event timings influence development more broadly is poorly understood. Here, we measure organismal development as spectra of energy in pixel values of video, creating high-dimensional landscapes integrating development of all visible form and function. This approach we termed ‘Energy proxy traits’ (EPTs) is applied alongside previously identified heterochronies in three freshwater pulmonate molluscs (Lymnaea stagnalis, Radix balthica and Physella acuta). EPTs were calculated from time-lapse video of embryonic development to construct a continuous functional time series. High-dimensional transitions in phenotype aligned with major sequence heterochronies between species. Furthermore, differences in event timings between conspecifics were associated with changes in high-dimensional phenotypic space. We reveal EPTs as a powerful approach to considering the evolutionary importance of alterations to developmental event timings. Reimagining the phenotype as energy spectra enabled continuous quantification of developmental changes in high-dimensional phenotypic space, rather than measurement of timings of discrete events. This approach has the possibility to transform how we study heterochrony and development more generally

In-Flight Water Quality Monitoring on the International Space Station (ISS): Measuring Biocide Concentrations with Colorimetric Solid Phase Extraction (CSPE)

The colorimetric water quality monitoring kit (CWQMK) was delivered to the International Space Station (ISS) on STS-128/17A and was initially deployed in September 2009. The kit was flown as a station development test objective (SDTO) experiment to evaluate the acceptability of colorimetric solid phase extraction (CSPE) technology for routine water quality monitoring on the ISS. During the SDTO experiment, water samples from the U.S. water processor assembly (WPA), the U.S. potable water dispenser (PWD), and the Russian system for dispensing ground-supplied water (SVO-ZV) were collected and analyzed with the CWQMK. Samples from the U.S. segment of the ISS were analyzed for molecular iodine, which is the biocide added to water in the WPA. Samples from the SVOZV system were analyzed for ionic silver, the biocide used on the Russian segment of the ISS. In all, thirteen in-flight analysis sessions were completed as part of the SDTO experiment. This paper provides an overview of the experiment and reports the results obtained with the CWQMK. The forward plan for certifying the CWQMK as operational hardware and expanding the capabilities of the kit are also discussed

Gemcitabine and Irinotecan for Patients with Untreated Extensive Stage Small Cell Lung Cancer: SWOG 0119

IntroductionTo evaluate the activity of a nonplatinum-, nonetoposide-containing regimen for patients with extensive stage small cell lung cancer.MethodsPatients with untreated extensive stage small cell lung cancer were treated with gemcitabine 1000 mg/m2 and irinotecan 100 mg/m2 on days 1 and 8 of a 21-day cycle for a maximum of six cycles. Patients with brain metastases were eligible if asymptomatic or controlled after radiation.ResultsEighty-four eligible patients with untreated extensive stage small cell lung cancer with adequate organ function and a performance status of 0–2 were accrued. The median age was 64 years (range, 42–85) and 45 (54%) were women. Six cycles were completed by 28 (33%) patients. Some degree of diarrhea occurred in 57% (grade 3/4, 18%). Other grade 3/4 toxicities were neutropenia (26%), anemia (10%), thrombocytopenia (8%), febrile neutropenia (5%), fatigue (11%), nausea (10%), and vomiting (8%). The response rate was 32% (95% confidence interval: 22%–43%) among the 81 patients with measurable disease. The median survival was 8.5 months (95% confidence interval: 7.0–9.8) with 1- and 2-year survival rates of 26% and 7%, respectively. Salvage therapy data were captured by prospective collection, and only 50% of patients were treated secondarily.ConclusionThe overall response rate with the combination of gemcitabine and irinotecan was disappointing, and the median survival rate was lower than expected. Further development of this combination in small cell lung cancer is not recommended