Developing an undergraduate software engineering degree

As those who have done it can attest, developing an undergraduate degree in software engineering is a daunting and challenging task, and there have been instances where a department has tried, but failed to get its program approved. A strong desire to develop a program in software engineering together with interested faculty may not be enough to build a credible degree, let alone a curriculum that will be approved by all the administrative and State organizations who may have a say in it .This panel brings together a group whose experience in developing software engineering degrees at their respective institutions may be helpful to those thinking about doing so. Each member of the group will describe his/her experiences in developing an undergraduate program in software engineering and address key issues and problems that should be considered in any such effort. There will also be ample opportunity for interaction among the participants

Foreign Object Debris Detection System Cost-Benefit Analysis

Foreign object debris (FOD) poses significant safety and financial threats to aviation. Estimates of the annual global costs of FOD range up to $22.7 billion in current United States dollars. The Federal Aviation Administration (FAA) recognizes that airport FOD detection systems can help reduce FOD risks. The FAA Airport Technology Research and Development Branch research team reviewed a recent cost-benefit analysis (CBA) of such systems. Inputs to this analysis included stakeholder interviews, literature review, safety and operational databases, and airport FOD detection records

GRMHD simulations of accretion onto Sgr A*: How important are radiative losses?

We present general relativistic magnetohydrodynamic (GRMHD) numerical simulations of the accretion flow around the supermassive black hole in the Galactic centre, Sagittarius A* (Sgr A*). The simulations include for the first time radiative cooling processes (synchrotron, bremsstrahlung, and inverse Compton) self-consistently in the dynamics, allowing us to test the common simplification of ignoring all cooling losses in the modeling of Sgr A*. We confirm that for Sgr A*, neglecting the cooling losses is a reasonable approximation if the Galactic centre is accreting below ~10^{-8} Msun/yr i.e. Mdot < 10^{-7} Mdot_Edd. But above this limit, we show that radiative losses should be taken into account as significant differences appear in the dynamics and the resulting spectra when comparing simulations with and without cooling. This limit implies that most nearby low-luminosity active galactic nuclei are in the regime where cooling should be taken into account. We further make a parameter study of axisymmetric gas accretion around the supermassive black hole at the Galactic centre. This approach allows us to investigate the physics of gas accretion in general, while confronting our results with the well studied and observed source, Sgr A*, as a test case. We confirm that the nature of the accretion flow and outflow is strongly dependent on the initial geometry of the magnetic field. For example, we find it difficult, even with very high spins, to generate powerful outflows from discs threaded with multiple, separate poloidal field loops.Comment: Resubmitted to MNRAS, including modifications in response to referee report. 13 pages, 15 figure

Could the 2012 Drought in Central U.S. Have Been Anticipated? A Review of NASA Working Group Research

This paper summarizes research related to the 2012 record drought in the central United States conducted by members of the NASA Energy and Water cycle Study (NEWS) Working Group. Past drought patterns were analyzed for signal coherency with latest drought and the contribution of long-term trends in the Great Plains low-level jet, an important regional circulation feature of the spring rainy season in the Great Palins. Long-term changes in the seasonal transition from rainy spring into dry summer were also examined. Potential external forcing from radiative processes, soil-air interactions, and ocean teleconnections were assessed as contributors to the intensity of the drought. The atmospheric Rossby wave activity was found to be a potential source of predictability for the onset of drought. A probabilistic model was introduced and evaluated for its performance in predicting drought recovery in the Great Plains

Radiative Models of Sagittarius A* and M87 from Relativistic MHD Simulations

Ongoing millimeter VLBI observations with the Event Horizon Telescope allow unprecedented study of the innermost portion of black hole accretion flows. Interpreting the observations requires relativistic, time-dependent physical modeling. We discuss the comparison of radiative transfer calculations from general relativistic MHD simulations of Sagittarius A* and M87 with current and future mm-VLBI observations. This comparison allows estimates of the viewing geometry and physical conditions of the Sgr A* accretion flow. The viewing geometry for M87 is already constrained from observations of its large-scale jet, but, unlike Sgr A*, there is no consensus for its millimeter emission geometry or electron population. Despite this uncertainty, as long as the emission region is compact, robust predictions for the size of its jet launching region can be made. For both sources, the black hole shadow may be detected with future observations including ALMA and/or the LMT, which would constitute the first direct evidence for a black hole event horizon.Comment: 8 pages, 2 figures, submitted to the proceedings of AHAR 2011: The Central Kiloparse

Three microarray platforms: an analysis of their concordance in profiling gene expression

BACKGROUND: Microarrays for the analysis of gene expression are of three different types: short oligonucleotide (25–30 base), long oligonucleotide (50–80 base), and cDNA (highly variable in length). The short oligonucleotide and cDNA arrays have been the mainstay of expression analysis to date, but long oligonucleotide platforms are gaining in popularity and will probably replace cDNA arrays. As part of a validation study for the long oligonucleotide arrays, we compared and contrasted expression profiles from the three formats, testing RNA from six different cell lines against a universal reference standard. RESULTS: The three platforms had 6430 genes in common. In general, correlation of gene expression levels across the platforms was good when defined by concordance in the direction of expression difference (upregulation or downregulation), scatter plot analysis, principal component analysis, cell line correlation or quantitative RT-PCR. The overall correlations (r values) between platforms were in the range 0.7 to 0.8, as determined by analysis of scatter plots. When concordance was measured for expression ratios significant at p-values of <0.05 and at expression threshold levels of 1.5 and 2-fold, the agreement among the platforms was very high, ranging from 93% to 100%. CONCLUSION: Our results indicate that the long oligonucleotide platform is highly suitable for expression analysis and compares favorably with the cDNA and short oligonucleotide varieties. All three platforms can give similar and reproducible results if the criterion is the direction of change in gene expression and minimal emphasis is placed on the magnitude of change

Ocean water vapor and cloud liquid water trends from 1992 to 2005 TOPEX Microwave Radiometer data

The continuous 1992–2005 data set of the TOPEX Microwave Radiometer (TMR) has been reprocessed to provide global, zonal, and regional scale histories of overocean integrated water vapor (IWV) and cloud liquid water (CLW). Results indicate well-defined trends in IWV on global and hemisphere scales, with values of 1.8 ± 0.4%/decade (60°S–60°N), 2.4 ± 0.4%/decade (0–60°N), and 1.0 ± 0.5%/decade (0–60°S). The uncertainties represent 1 standard deviation of the regressed slope parameter adjusted for lag 1 autocorrelation. These results are comparable to earlier results based on analyses of the multiinstrument SSM/I ocean measurements beginning in 1988. For the 1992–2005 interval, comparisons between SSM/I- and TMR-derived IWV trends show remarkable agreement, with global trends differing by less than 0.3%/decade, comparable to the statistical uncertainty level and about one-sixth of the global TMR-derived trend. Latitudinal and regional analyses of IWV trends show large variability about the global mean, with synoptic scale variations of IWV trends ranging from ∼−8 to +8%/decade. Averaged over 5° latitude bands the IWV trends reveal a near zero minimum in the Southern Tropical Pacific and maximum values of ∼4%/decade over the 30–40N latitude band. Comparisons with band latitude averaged SST data over the same 1992–2005 interval roughly match a delta_IWV/delta_SST trend scaling of ∼11%/K, consistent with previously observed tropical and midlatitude seasonal variability. TMR-derived CLW trends are fractionally comparable to the IWV trends. The CLW values are 1.5 ± 0.6%/decade (60°S–60°N), 2.0 ± 0.8%/decade (0–60°N), and 1.1 ± 0.8%/decade (0–60°S). When scaled to global mean CLW derived from SSM/I and compared seasonally, the TMR CLW variations exhibit excellent tracking with the SSM/I results. Unlike IWV, however, the CLW statistical uncertainties do not likely reflect the dominant error component in the retrieved trends. The 1992–2005 CLW trend estimates were particularly sensitive to short-term trends in the first and last 2 years of the TMR archive. Additional errors difficult to quantify include strong aliasing effects from precipitation cells and uncertainties in the radiative transfer models utilized in the generation of the TMR CLW algorithm

The observed state of the water cycle in the early twenty-first century

Author Posting. © American Meteorological Society, 2015. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 28 (2015): 8289–8318, doi:10.1175/JCLI-D-14-00555.1.This study quantifies mean annual and monthly fluxes of Earth’s water cycle over continents and ocean basins during the first decade of the millennium. To the extent possible, the flux estimates are based on satellite measurements first and data-integrating models second. A careful accounting of uncertainty in the estimates is included. It is applied within a routine that enforces multiple water and energy budget constraints simultaneously in a variational framework in order to produce objectively determined optimized flux estimates. In the majority of cases, the observed annual surface and atmospheric water budgets over the continents and oceans close with much less than 10% residual. Observed residuals and optimized uncertainty estimates are considerably larger for monthly surface and atmospheric water budget closure, often nearing or exceeding 20% in North America, Eurasia, Australia and neighboring islands, and the Arctic and South Atlantic Oceans. The residuals in South America and Africa tend to be smaller, possibly because cold land processes are negligible. Fluxes were poorly observed over the Arctic Ocean, certain seas, Antarctica, and the Australasian and Indonesian islands, leading to reliance on atmospheric analysis estimates. Many of the satellite systems that contributed data have been or will soon be lost or replaced. Models that integrate ground-based and remote observations will be critical for ameliorating gaps and discontinuities in the data records caused by these transitions. Continued development of such models is essential for maximizing the value of the observations. Next-generation observing systems are the best hope for significantly improving global water budget accounting.This research was funded by multiple grants from NASA’s Energy and Water Cycle Study (NEWS) program.2016-05-0

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes