SOS rule formats for convex and abstract probabilistic bisimulations

Probabilistic transition system specifications (PTSSs) in the $nt \mu f\theta / nt\mu x\theta$ format provide structural operational semantics for Segala-type systems that exhibit both probabilistic and nondeterministic behavior and guarantee that bisimilarity is a congruence for all operator defined in such format. Starting from the $nt \mu f\theta / nt\mu x\theta$ format, we obtain restricted formats that guarantee that three coarser bisimulation equivalences are congruences. We focus on (i) Segala's variant of bisimulation that considers combined transitions, which we call here "convex bisimulation"; (ii) the bisimulation equivalence resulting from considering Park & Milner's bisimulation on the usual stripped probabilistic transition system (translated into a labelled transition system), which we call here "probability obliterated bisimulation"; and (iii) a "probability abstracted bisimulation", which, like bisimulation, preserves the structure of the distributions but instead, it ignores the probability values. In addition, we compare these bisimulation equivalences and provide a logic characterization for each of them.Comment: In Proceedings EXPRESS/SOS 2015, arXiv:1508.0634

Flood Insurance Demand along the Gulf and Florida Coast

The objective of this research is to identify factors that influence both the decision (yes or no) and level of flood insurance among coastal homeowners in the southeast U.S. Recently flood damage has dramatically increased (Flood), and Crossett et al. (2004) report that coastal populations are growing. And in spite of rising costs of living in coastal areas, people are willing to pay more for access to ocean views and other natural amenities associated with coastal living (Bin and Kruse, 2006). Although the federal government provides flood insurance programs and encourages at-risk residents to insure their property from flood, rates of uptake remain low (Burby, 2001; Kunreuther, 2006; Landry and Jahan-Parvar, 2009). The National Flood Insurance Program (NFIP) was created to provide often subsidized premiums to cover losses which private insurance markets failed to offer. However, as Kunreuther et al.(1978) argue, many people do not bother to prepare, and have a low willingness to pay for coverage, even if subsidized (Kunreuther 1996). However, of those who have previously experienced flooding, they tend to insure their properties more (McClelland, Schulze, and Coursey 1993). Based on previous literature, we identified key factors to establish testable hypotheses regarding effect on flood insurance demand. These include: income, previous flood experience, the presence of a mortgage, home location (both flood zone status and distance from the shore), participation in CRS, the distance from the coast, the house construction year as well as measures of respondent risk preferences and perceptions. Data on flood coverage level and the above explanatory variables were obtained via revealed-preference online survey method, contracted through Knowledge Networks (KN) during August-September 2010. We chose to contract with KN for several reasons. First, they are, to our knowledge, the only survey firm that can legitimately say they have a true probability based sample for an online survey because they recruit by phone and/or mail (randomly selected using random-digit dialing (RDD) or by using address-based sampling); additionally they provide internet access to households that do not have it. KN was also contracted to overcome the typical of low response rate when surveying the general public. KN uses an online panel (called the “Knowledge Panel”). KN Panel members that were homeowners were sampled from 95 counties in Gulf Coast and Florida Atlantic Coast counties in AL, FL, LA, MS, and TX, with an 47% response rate (720 observations), with 67% from FL, 24% from TX, 5% from LA, and 4% collectively from AL and MS. As expected, insurance purchase is positively affected by the individual’s risk perception, their risk preference, whether or not they have a mortgage, flood zone residence, their income, CRS, previous flood experience, and the year of construction of house. Coefficients of mortgage and risk perception, income, flood zone are significant at 0.05 the level. Additionally, the coefficient of distance from the coast is only significant at the 0.1 level.Flood Insurance, Risk, Insurance Demand, Environmental Economics and Policy, Risk and Uncertainty,

Multimodal segmentation of lifelog data

A personal lifelog of visual and audio information can be very helpful as a human memory augmentation tool. The SenseCam, a passive wearable camera, used in conjunction with an iRiver MP3 audio recorder, will capture over 20,000 images and 100 hours of audio per week. If used constantly, very soon this would build up to a substantial collection of personal data. To gain real value from this collection it is important to automatically segment the data into meaningful units or activities. This paper investigates the optimal combination of data sources to segment personal data into such activities. 5 data sources were logged and processed to segment a collection of personal data, namely: image processing on captured SenseCam images; audio processing on captured iRiver audio data; and processing of the temperature, white light level, and accelerometer sensors onboard the SenseCam device. The results indicate that a combination of the image, light and accelerometer sensor data segments our collection of personal data better than a combination of all 5 data sources. The accelerometer sensor is good for detecting when the user moves to a new location, while the image and light sensors are good for detecting changes in wearer activity within the same location, as well as detecting when the wearer socially interacts with others

A Comparison of Interpolation Methods for Sparse Data: Application to Wind and Concentration Fields

In order to produce gridded fields of pollutant concentration data and surface wind data for use in an air quality model, a number of techniques for interpolating sparse data values are compared. The techniques are compared using three data sets. One is an idealized concentration distribution to which the exact solution is known, the second is a potential flow field, while the third consists of surface ozone concentrations measured in the Los Angeles Basin on a particular day. The results of the study indicate that fitting a second-degree polynomial to each subregion (triangle) in the plane with each data point weighted according to its distance from the subregion provides a good compromise between accuracy and computational cost

Biochemical Properties of a Decoy Oligodeoxynucleotide Inhibitor of STAT3 Transcription Factor.

Cyclic STAT3 decoy (CS3D) is a second-generation, double-stranded oligodeoxynucleotide (ODN) that mimics a genomic response element for signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. CS3D competitively inhibits STAT3 binding to target gene promoters, resulting in decreased expression of proteins that promote cellular proliferation and survival. Previous studies have demonstrated antitumor activity of CS3D in preclinical models of solid tumors. However, prior to entering human clinical trials, the efficiency of generating the CS3D molecule and its stability in biological fluids should be determined. CS3D is synthesized as a single-stranded ODN and must have its free ends ligated to generate the final cyclic form. In this study, we report a ligation efficiency of nearly 95 percent. The ligated CS3D demonstrated a half-life of 7.9 h in human serum, indicating adequate stability for intravenous delivery. These results provide requisite biochemical characterization of CS3D that will inform upcoming clinical trials

Allosteric Inhibition of Factor XIIIa. Non-Saccharide Glycosaminoglycan Mimetics, but Not Glycosaminoglycans, Exhibit Promising Inhibition Profile

Factor XIIIa (FXIIIa) is a transglutaminase that catalyzes the last step in the coagulation process. Orthostery is the only approach that has been exploited to design FXIIIa inhibitors. Yet, allosteric inhibition of FXIIIa is a paradigm that may offer a key advantage of controlled inhibition over orthosteric inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We reasoned that targeting a collection of basic amino acid residues distant from FXIIIa’s active site by using sulfated glycosaminoglycans (GAGs) or non-saccharide GAG mimetics (NSGMs) would lead to the discovery of the first allosteric FXIIIa inhibitors. We tested a library of 22 variably sulfated GAGs and NSGMs against human FXIIIa to discover promising hits. Interestingly, although some GAGs bound to FXIIIa better than NSGMs, no GAG displayed any inhibition. An undecasulfated quercetin analog was found to inhibit FXIIIa with reasonable potency (efficacy of 98%). Michaelis-Menten kinetic studies revealed an allosteric mechanism of inhibition. Fluorescence studies confirmed close correspondence between binding affinity and inhibition potency, as expected for an allosteric process. The inhibitor was reversible and at least 9-fold- and 26-fold selective over two GAG-binding proteins factor Xa (efficacy of 71%) and thrombin, respectively, and at least 27-fold selective over a cysteine protease papain. The inhibitor also inhibited the FXIIIa-mediated polymerization of fibrin in vitro. Overall, our work presents the proof-of-principle that FXIIIa can be allosterically modulated by sulfated non-saccharide agents much smaller than GAGs, which should enable the design of selective and safe anticoagulants

The equilibrium model for the effect of temperature on enzymes: Insights and implications

A new, experimentally-validated “Equilibrium Model” describes the effect of temperature on enzymes, and provides a new mechanism for the reversible loss of enzyme activity with temperature. It incorporates two new, fundamental parameters that allow a complete description of the effect of temperature on enzyme activity: ΔHeq and Teq. ΔHeq emerges as an intrinsic and quantitative measure of enzyme eurythermal adaptation, while Teq, the equilibrium temperature, has fundamental and technological significance for our understanding of the effect of temperature on enzymatic reactions. For biotechnological purposes, these parameters need to be considered when enzymes are applied or engineered for activity at high temperatures