Using a Dynamic Domain-Specific Modeling Language for the Model-Driven Development of Cross-Platform Mobile Applications

There has been a gradual but steady convergence of dynamic programming languages with modeling languages. One area that can benefit from this convergence is modeldriven development (MDD) especially in the domain of mobile application development. By using a dynamic language to construct a domain-specific modeling language (DSML), it is possible to create models that are executable, exhibit flexible type checking, and provide a smaller cognitive gap between business users, modelers and developers than more traditional model-driven approaches. Dynamic languages have found strong adoption by practitioners of Agile development processes. These processes often rely on developers to rapidly produce working code that meets business needs and to do so in an iterative and incremental way. Such methodologies tend to eschew “throwaway” artifacts and models as being wasteful except as a communication vehicle to produce executable code. These approaches are not readily supported with traditional heavyweight approaches to model-driven development such as the Object Management Group’s Model-Driven Architecture approach. This research asks whether it is possible for a domain-specific modeling language written in a dynamic programming language to define a cross-platform model that can produce native code and do so in a way that developer productivity and code quality are at least as effective as hand-written code produced using native tools. Using a prototype modeling tool, AXIOM (Agile eXecutable and Incremental Objectoriented Modeling), we examine this question through small- and mid-scale experiments and find that the AXIOM approach improved developer productivity by almost 400%, albeit only after some up-front investment. We also find that the generated code can be of equal if not better quality than the equivalent hand-written code. Finally, we find that there are significant challenges in the synthesis of a DSML that can be used to model applications across platforms as diverse as today’s mobile operating systems, which point to intriguing avenues of subsequent research

Clinging to History: The Supreme Court (Mis)Interprets Federal Rule of Evidence 801(d)(1)(B) as Containing a Temporal Requirement

The adoption of the Federal Rules of Evidence (the Rules) resulted in a more liberal standard for the admission and use of various forms of evidence. For example, the Rules altered the definition of relevant evidence increasing the scope of evidence that can be presented to a jury. Also, the Rules per- mit prior inconsistent statements to be admitted as substantive evidence rather than for impeachment purposes only. The Advisory Committee enunciated these changes, and other changes resulting from the adoption of the Rules, in their notes accompanying the Rules

The Role of the Arabidopsis Phosphatidylinositol 3-Kinase in Vacuolar Protein Transport

In all eukaryotic organisms vesicle-mediated protein transport is crucial for maintaining cellular homeostasis. Over the past decade significant strides have been made in elucidating the molecular mechanisms governing this complex process. Both genetic and biochemical studies have demonstrated the unequivocal involvement of class III phospatidylinositol 3-kinases (PtdIns 3-kinases) in regulating vesicle transport. While PtdIns 3-kinases have been well studied in both yeast and mammalian systems, the role of these enzymes in plants is poorly understood. In the present study, we demonstrate that the Arabidopsis Ptdlns 3-kinase is localized to the cytoplasm, and perhaps the Golgi apparatus. Moreover, we show that reduction in cellular PtdIns(3)P levels is correlated with missorting of a vacuolar marker protein. Altogether, our data suggest that AtVps34p (and its lipid product PtdIns(3)P) is involved in regulating vesicle-mediated protein transport to the vacuole in Arabidopsis

Risk-value optimization of performance and cost for propellant production on Mars

The nominal two-and-a-half year round-trip Mars mission requires extensive infrastructure to transport and safeguard its human crew, thus requiring large amounts of Initial Mass in Low Earth Orbit (IMLEO). Any technologies that can reduce this load may have the potential to realize dramatic savings in overall architecture cost. One such technology is the in-situ production of propellant for the Mars ascent vehicle utilizing Martian resources, such as the atmosphere, rather than transporting the propellant from the Earth's surface to the Martian surface. This topic has previously been studied on the basis of the reduction of the IMLEO, because of the assumption that the reduction in IMLEO would lower Earth-to-orbit launch and space transportation costs more than the increase in in-situ propellant production system production and operations cost. However, with low-cost commercial launch now being considered by NASA, the costs of propellant production on Mars may not be a positive trade for these lower launch costs. The objective of this research is to evaluate, under uncertainty, an optimal ISPP system for a human-to-Mars mission. To do this, the necessary ISPP approaches and corresponding Mars transportation system architecture (consisting of the Earth-to-orbit, in-space, Mars descent, and ascent transportation systems) must be modeled in such a way that the effects of uncertainty in their performance and mass can be evaluated. With this framework, the sensitivity of the mass, power, volume, and cost of each ISPP approach and transportation architecture includes the uncertainty of its modeling, and the most relevant system architecture dependent parameters for each technology are identified for future research. Additionally, technologies will be compared using this framework to determine which has the greatest chance of success at having the least cost; this design approach will yield a ranked list of preferred ISPP approaches as compared to a non-ISPP baseline approach. The final product of this research is an evaluation of each technology, including the uncertainty in its modeling parameters, as well as a ranked comparison of multiple ISPP approaches. From this, recommendations for an overall approach to Mars ISPP, as well as the most important technologies to be further researched, will be presented. This research serves as a guide to future mission planners, decision makers, and technology investors in planning the best path for the eventual human exploration of Mars.Ph.D

Legislative Subterfuge ?: Failing to Insure Persons with Mental Illness under the Mental Health Parity Act and the Americans with Disabilities Act

The two primary problems with providing health care in the United States are cost and access., The cost of health care rose dramatically during the 1970s and 1980s and continues to increase, making coset containment crucial to the availability of care. In addition, many Americans are either entirely without health insurance or are underinsured for catastrophic illness. While individually these two issues are important, equally problematic is the tension that exists between them. Providing greater access to additional services results either in a cost increase or the loss of other services. Ultimately, however, a general plan to contain costs can address the two issues simultaneously because the ability to contain costs can create greater access. The issues of access and cost are particularly pronounced in insurance for mental health services. For those Americans with private insurance, most coverage is provided by employer-sponsored health plans. In these plans, mental health care is possibly the most common target of coverage limitations on services and illnesses.,\u27 These limitations cap benefits for mental health care at far lower levels than those for traditional medical and surgical care. Both the need to keep premiums affordable and the perception that diagnosis and treatment of mental health is less reliable and effective than treatment of regular physical medical care are the primary reasons for the commonality of these limitations. While commentators have advocated more equality in insurance coverage, the concept of parity between mental health coverage and other medical coverage in insurance plans did not gain national prominence until the 1990s, when the issue came to the forefront of legal scholarship. In addition, mental health parity finally had congressional allies on both sides of the aisle-most notably, Republican Senator Pete Domenici of Arizona. Recent parity efforts have focused on eliminating the use of mental illness limitations-primarily annual and lifetime monetary caps, durational inpatient and outpatient limits, coinsurance rates, and deductibles--that are set at lower levels than limitations on physical health care

Statistical variability of top of atmosphere cloud-free shortwave aerosol radiative effect

International audienceThe statistical variability of globally averaged MODIS aerosol optical thickness at 0.55 ?m (AOT) and top of atmosphere CERES cloud-free shortwave radiative effect (SWRE) is presented. Statistical variability is defined as the robustness of globally averaged statistics relative to data distribution. At the CERES footprint level, which we label "raw data", both the AOT and SWRE data derived from clear-sky CERES-SSF products show significant deviations from a normal distribution as evidenced by high skewness values. The spatial and temporal distribution of the data is also not uniform, with a greater concentration of data occurring in aerosol heavy-regions. As a result, globally averaged AOT and SWRE are overestimated when derived from raw data alone. To compensate, raw data are gridded into 2×2 degree grid-cells (called "gridded" data) to reduce the effect of spatial non-uniformity. However, the underlying non-normal distribution remains and manifests itself by increasing the uncertainty of grid-cell values. Globally averaged AOT and SWRE derived from a gridded dataset are substantially lower than those derived from raw data alone. The range of globally averaged AOT and SWRE values suggests that up to a 50% statistical variability exists, much of which is directly tied to how the data are manipulated prior to averaging. This variability increases when analyzing aerosol components (e.g. anthropogenic) since component AOT (and SWRE) may not exist at all locations were AOT is present. As a result, regions where a particular component AOT does not exist must either not be included in the global average or have data within these regions set to null values. However, each method produces significantly different results. The results of this work indicate simple mean and standard deviation statistics do not adequately describe global aerosol climate forcing data sets like the one used here. We demonstrate that placing raw observations on to a uniform grid is a necessary step before calculating global statistics. However, this by no means eliminates uncertainty in globally averaged AOT and SWRE values, while adding its own set of assumptions. When reporting any globally averaged statistic, it is important to report corresponding distribution and coverage information, in the form of skewness values, probability density functions, and spatial distribution plots, to help quantify its usefulness and robustness

A reanalysis of MODIS fine mode fraction over ocean using OMI and daily GOCART simulations

Using daily Goddard Chemistry Aerosol Radiation and Transport (GOCART) model simulations and columnar retrievals of 0.55 μm aerosol optical thickness (AOT) and fine mode fraction (FMF) from the Moderate Resolution Imaging Spectroradiometer (MODIS), we estimate the satellite-derived aerosol properties over the global oceans between June 2006 and May 2007 due to black carbon (BC), organic carbon (OC), dust (DU), sea-salt (SS), and sulfate (SU) components. Using Aqua-MODIS aerosol properties embedded in the CERES-SSF product, we find that the mean MODIS FMF values for each aerosol type are SS: 0.31 ± 0.09, DU: 0.49 ± 0.13, SU: 0.77 ± 0.16, and (BC + OC): 0.80 ± 0.16. We further combine information from the ultraviolet spectrum using the Ozone Monitoring Instrument (OMI) onboard the Aura satellite to improve the classification process, since dust and carbonate aerosols have positive Aerosol Index (AI) values >0.5 while other aerosol types have near zero values. By combining MODIS and OMI datasets, we were able to identify and remove data in the SU, OC, and BC regions that were not associated with those aerosol types. <br><br> The same methods used to estimate aerosol size characteristics from MODIS data within the CERES-SSF product were applied to Level 2 (L2) MODIS aerosol data from both Terra and Aqua satellites for the same time period. As expected, FMF estimates from L2 Aqua data agreed well with the CERES-SSF dataset from Aqua. However, the FMF estimate for DU from Terra data was significantly lower (0.37 vs. 0.49) indicating that sensor calibration, sampling differences, and/or diurnal changes in DU aerosol size characteristics were occurring. Differences for other aerosol types were generally smaller. Sensitivity studies show that a difference of 0.1 in the estimate of the anthropogenic component of FMF produces a corresponding change of 0.2 in the anthropogenic component of AOT (assuming a unit value of AOT). This uncertainty would then be passed along to any satellite-derived estimates of anthropogenic aerosol radiative effects