The International Space Station Habitat

The International Space Station (ISS) is an engineering project unlike any other. The vehicle is inhabited and operational as construction goes on. The habitability resources available to the crew are the crew sleep quarters, the galley, the waste and hygiene compartment, and exercise equipment. These items are mainly in the Russian Service Module and their placement is awkward for the crew to deal with ISS assembly will continue with the truss build and the addition of International Partner Laboratories. Also, Node 2 and 3 will be added. The Node 2 module will provide additional stowage volume and room for more crew sleep quarters. The Node 3 module will provide additional Environmental Control and Life Support Capability. The purpose of the ISS is to perform research and a major area of emphasis is the effects of long duration space flight on humans, a result of this research they will determine what are the habitability requirements for long duration space flight

Scaling and memory in the non-poisson process of limit order cancelation

The order submission and cancelation processes are two crucial aspects in the price formation of stocks traded in order-driven markets. We investigate the dynamics of order cancelation by studying the statistical properties of inter-cancelation durations defined as the waiting times between consecutive order cancelations of 22 liquid stocks traded on the Shenzhen Stock Exchange of China in year 2003. Three types of cancelations are considered including cancelation of any limit orders, of buy limit orders and of sell limit orders. We find that the distributions of the inter-cancelation durations of individual stocks can be well modeled by Weibulls for each type of cancelation and the distributions of rescaled durations of each type of cancelations exhibit a scaling behavior for different stocks. Complex intraday patterns are also unveiled in the inter-cancelation durations. The detrended fluctuation analysis (DFA) and the multifractal DFA show that the inter-cancelation durations possess long-term memory and multifractal nature, which are not influenced by the intraday patterns. No clear crossover phenomenon is observed in the detrended fluctuation functions with respect to the time scale. These findings indicate that the cancelation of limit orders is a non-Poisson process, which has potential worth in the construction of order-driven market models.Comment: 13 Latex pages, 6 figure

Exile Vol. XIII No. 2

FICTION The Garden by Joyce Horvath 5-8 Early Morning Man by Harvey Spurlock 12-24 28 Nisan 1960 by Cem Kozlu 29-35 Letters to the Editor by Rick Brown 39-55 POETRY World II by Jeffrey R. Smith 1-4 It is not for no reason by Bonnie Bishop 9 I have often wondered by Mike Engle 10 Without opera glasses by Trudi Spaeth 10 Differentiations in August by Alan Pavlik 11 Gold by Nancy Scott 25 With images by Trudi Spaeth 25 Grandpa by Karen Cozart 26-27 Meditation on a Line by Sylvia Plath by Lauren Shakely 28 Bantling by Francie King 36 Haiku by Suzanne Husting 36 I saw you yesterday by Rick Tucker 37 My Eyes Would Escape 38 ART untitled by Nancy Eastlake 8 The Diary of a Madman by Clare Conrad 24 Trumpeter by Bill Henderson 38 Untitled by Nancy Eastlake Cover design: Kee McFarland With special thanks to Mrs. Louis Brakeman for her services

Empirical shape function of limit-order books in the Chinese stock market

We have analyzed the statistical probabilities of limit-order book (LOB) shape through building the book using the ultra-high-frequency data from 23 liquid stocks traded on the Shenzhen Stock Exchange in 2003. We find that the averaged LOB shape has a maximum away from the same best price for both buy and sell LOBs. The LOB shape function has nice exponential form in the right tail. The buy LOB is found to be abnormally thicker for the price levels close to the same best although there are much more sell orders on the book. We also find that the LOB shape functions for both buy and sell sides have periodic peaks with a period of five. The 1-min averaged volumes at fixed tick level follow lognormal distributions, except for the left tails which display power-law behaviors, and exhibit long memory. Academic implications of our empirical results are also discussed briefly.Comment: 10 Elsart page including 4 figure

How markets slowly digest changes in supply and demand

In this article we revisit the classic problem of tatonnement in price formation from a microstructure point of view, reviewing a recent body of theoretical and empirical work explaining how fluctuations in supply and demand are slowly incorporated into prices. Because revealed market liquidity is extremely low, large orders to buy or sell can only be traded incrementally, over periods of time as long as months. As a result order flow is a highly persistent long-memory process. Maintaining compatibility with market efficiency has profound consequences on price formation, on the dynamics of liquidity, and on the nature of impact. We review a body of theory that makes detailed quantitative predictions about the volume and time dependence of market impact, the bid-ask spread, order book dynamics, and volatility. Comparisons to data yield some encouraging successes. This framework suggests a novel interpretation of financial information, in which agents are at best only weakly informed and all have a similar and extremely noisy impact on prices. Most of the processed information appears to come from supply and demand itself, rather than from external news. The ideas reviewed here are relevant to market microstructure regulation, agent-based models, cost-optimal execution strategies, and understanding market ecologies.Comment: 111 pages, 24 figure

Author Correction: A consensus-based transparency checklist.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Tooth micro-hardness changes after applying bioactive glass-containing, anti-microbial sealants

The AAPD recommends placement of dental pit and fissure sealants on surfaces that are high risk or that already exhibit incipient carious lesions. Protection provided by sealants may be enhanced by the addition of ion-releasing, anti-microbial filler particles of bioactive glass. Objective: We prepared novel dental pit and fissure sealant materials containing bioactive glass (BAG) fillers and tested their ability to prevent tooth demineralization in a bacterial broth. Methods: Two types of BAG were synthesized in our lab: BAG1 (61 wt% silica - 31 wt% calcia - 4 wt% phosphate - 4 wt% flouride); and BAG2 (81 wt% silica - 11 wt% calcia - 4 wt% phosphate - 4 wt% flouride). Ultraseal XT (USXT) resin without filler was supplied by the manufacturer (Ultradent Products, Inc. South Jordan, UT). BAGs were individually incorporated into the resin (25 wt%) and provided handling properties similar to USXT. Caries-free teeth (n=5 each) were randomly assigned to three groups (BAG1-sealant, BAG2-sealant,or USXT) and sealants were placed by the same practitioner. Acid-resistant nail polish was used to cover half of the tooth surface. Teeth were immersed in a bacterial culture system of sucrose-rich brain-heart infusion (BHI) media containing Streptococcus mutans strain #25175, an acid-producing microbe and incubated at 37˚C, 5%CO2; media was changed every other day. Bacterial growth was confirmed throughout the test period. At two weeks, teeth were sectioned sagitally and microhardness testing compared changes in hardness as a function of location on the tooth. Results : Overall, the BAG2-sealant samples were significantly harder than the BAG1-sealant or USXT samples. Areas adjacent to the BAG2-sealant were harder than the original tooth surface. (ANOVA/Tukey’s; α=0.05). Conclusion: The inclusion of anti-bacterial, ion-releasing BAG as a filler component results in a harder tooth that may be better able to resist demineralization.This presentation was presented at the American Association for the Advancement of Science (AAAS) Pacific Division 93rd Annual Meeting in Boise, Idaho. It was also presented at the American Association for Dental Research Annual Conference in 2012 (AADR)

A consensus-based transparency checklist

We present a consensus-based checklist to improve and document the transparency of research reports in social and behavioural research. An accompanying online application allows users to complete the form and generate a report that they can submit with their manuscript or post to a public repository