Protein Array Fabrication with E-jet Printing

We demonstrate the feasibility of fabricate biosensors with direct protein printing without complicated processes at high resolution and area coverage. Printed single protein, streptavidin-fluorescein, binds to biotin labeled with fluorescent DNA without denaturation; therefore a fluorescence microscope can detect the printed droplets as shown in Figure 7.1(a). The standard deviation of the spot size and spacing is 7.26 % and 0.693%, respectively. The e-jet printing is capable to print large area, e.g., one inch size. Half droplets of streptavidin-Cy5 are printed in 15 minutes (Figure 7.1(b)). Four-inch size printing is also available. Moreover, we have developed the multi-syringe head [1]. The head prints multiple inks by rotation. Even complicated patterns of multiple proteins (e.g., peacock shown in Figure 7.1(c)) can be printed. Printed primary antibodies can be detected under a fluorescence microscopy by incubating with fluorescently-labeled secondary antibodies [2]. These capabilities show that the e-jet printer with the multi-syringe head has feasibility to make protein chips to detect multiple proteins at lower cost than the conventional chips

Is Choice Modelling Really Necessary? Public versus expert values for marine reserves in Western Australia

One of the motivations for choice modelling is to provide values that can be used to inform decisionmakers about the non-market costs and benefits of proposed projects or policies. However, the question must be asked as to whether decision-makers consider choice modelling to be a policy relevant tool. There may be more cost-effective and convenient means of providing comparable policy guidance than commissioning a choice modelling study. For example, advice on decision options may be sought from experts, such as scientists. However, expert advice may not accurately reflect the value judgements of the public. The aim of this study is to investigate whether public and expert preferences diverge, using the choice modelling technique. Two case studies are utilised – the Ningaloo Marine Park and the proposed Ngari Capes Marine Park in Western Australia. Evidence of both divergence and convergence between public and expert values is found in different instances, with public awareness factors playing a role in this divide. Where preference divergence appears likely, decision-makers should consider choice modelling as a useful tool to inform policy.Choice modelling, valuation, experts, public, marine parks, Research Methods/ Statistical Methods,

Evolutionary Analysis of Gaseous Sub-Neptune-Mass Planets with MESA

Sub-Neptune-sized exoplanets represent one of the most common types of planets in the Milky Way, yet many of their properties are unknown. Here, we present a prescription to adapt the capabilities of the stellar evolution toolkit Modules for Experiments in Stellar Astrophysics (MESA) to model sub-Neptune mass planets with H/He envelopes. With the addition of routines treating the planet core luminosity, heavy element enrichment, atmospheric boundary condition, and mass loss due to hydrodynamic winds, the evolutionary pathways of planets with diverse starting conditions are more accurately constrained. Using these dynamical models, we construct mass-composition relationships of planets from 1 to 400 $M_{\oplus}$ and investigate how mass-loss impacts their composition and evolution history. We demonstrate that planet radii are typically insensitive to the evolution pathway that brought the planet to its instantaneous mass, composition and age, with variations from hysteresis. We find that planet envelope mass loss timescales, $\tau_{\rm env}$, vary non-monotonically with H/He envelope mass fractions (at fixed planet mass). In our simulations of young (100~Myr) low-mass ($M_p\lesssim10~M_\oplus$) planets with rocky cores, $\tau_{\rm env}$ is maximized at $M_{\rm env}/M_p=1\%$ to $3\%$. The resulting convergent mass loss evolution could potentially imprint itself on the close-in planet population as a preferred H/He mass fraction of ${\sim}1\%$. Looking ahead, we anticipate that this numerical code will see widespread applications complementing both 3-D models and observational exoplanet surveys.Comment: 18 pages, 9 figures, and 4 tables. Accepted to the Astrophysical Journal on August 29th, 201

Some Thoughts on Terminology and Discipline in Design

In this speculative paper, I will argue that the design community should attempt to develop a “dictionary” of the language of design, along the same lines as the Oxford English Dictionary was and is developed: as a catalogue of the living use of terms. I will sketch an outline of how such a project could be started quite easily with modern technologies. I will then consider one word in particular – “discipline” – as an example of the need for such a dictionary, by examining the various senses of the word and how even just reflecting on that can illuminate issues of clear communications. Keywords: Terminology; Lexicography; Semantics; Dictionary; Communication; Language.</p

A Framework for Quantifying the Degeneracies of Exoplanet Interior Compositions

Several transiting super-Earths are expected to be discovered in the coming few years. While tools to model the interior structure of transiting planets exist, inferences about the composition are fraught with ambiguities. We present a framework to quantify how much we can robustly infer about super-Earth and Neptune-size exoplanet interiors from radius and mass measurements. We introduce quaternary diagrams to illustrate the range of possible interior compositions for planets with four layers (iron core, silicate mantles, water layers, and H/He envelopes). We apply our model to CoRoT-7b, GJ 436b, and HAT-P-11b. Interpretation of planets with H/He envelopes is limited by the model uncertainty in the interior temperature, while for CoRoT-7b observational uncertainties dominate. We further find that our planet interior model sharpens the observational constraints on CoRoT-7b's mass and radius, assuming the planet does not contain significant amounts of water or gas. We show that the strength of the limits that can be placed on a super-Earth's composition depends on the planet's density; for similar observational uncertainties, high-density super-Mercuries allow the tightest composition constraints. Finally, we describe how techniques from Bayesian statistics can be used to take into account in a formal way the combined contributions of both theoretical and observational uncertainties to ambiguities in a planet's interior composition. On the whole, with only a mass and radius measurement an exact interior composition cannot be inferred for an exoplanet because the problem is highly underconstrained. Detailed quantitative ranges of plausible compositions, however, can be found.Comment: 20 pages, 10 figures, published in Ap

Magnetohydrodynamic Simulations of the Atmosphere of HD 209458b

We present the first three-dimensional magnetohydrodynamic (MHD) simulations of the atmosphere of HD 209458b which self-consistently include reduction of winds due to the Lorentz force and Ohmic heating. We find overall wind structures similar to that seen in previous models of hot Jupiter atmospheres, with strong equatorial jets and meridional flows poleward near the day side and equatorward near the night side. Inclusion of magnetic fields slows those winds and leads to Ohmic dissipation. We find wind slowing ranging from 10%-40% for reasonable field strengths. We find Ohmic dissipation rates ~10^17 W at 100 bar, orders of magnitude too small to explain the inflated radius of this planet. Faster wind speeds, not achievable in these anelastic calculations, may be able to increase this value somewhat, but likely will not be able to close the gap necessary to explain the inflated radius. We demonstrate that the discrepancy between the simulations presented here and previous models is due to inadequate treatment of magnetic field geometry and evolution. Induced poloidal fields become much larger than those imposed, highlighting the need for a self-consistent MHD treatment of these hot atmospheres.Comment: 6 pages, 4 figures, accepted at ApJ

A unified framework for Schelling's model of segregation

Schelling's model of segregation is one of the first and most influential models in the field of social simulation. There are many variations of the model which have been proposed and simulated over the last forty years, though the present state of the literature on the subject is somewhat fragmented and lacking comprehensive analytical treatments. In this article a unified mathematical framework for Schelling's model and its many variants is developed. This methodology is useful in two regards: firstly, it provides a tool with which to understand the differences observed between models; secondly, phenomena which appear in several model variations may be understood in more depth through analytic studies of simpler versions.Comment: 21 pages, 3 figure

Phase and group delay calibration of a very long baseline interferometer by East Coast VLBI Group

Precisely timed pulses injected into the input of each receiver are used to calibrate the phase and group delay through each interferometer terminal. The short duration pulses are generated at a 1 MHz rate directly from the output of the frequency standard. The pulses are injected into the receiver at a level low enough to produce less than one percent increase in system temperature, yet can be extracted during processing with a high enough signal to noise ratio to determine the phase of the calibration rails within 1 degree in 1 second of integration. The calibration system also includes precise cable measurement electronics and a pulse echo for clock synchronization