Research and Debate

Since 11 September 2001, the U.S. defense budget has risen by about 25 percent, after factoring out inflation. The reasons for such an increase are numerous: si- multaneously fighting wars in both Afghanistan and Iraq, increases in military pay and benefits, and more money for some major weapons programs. In this same time period, money devoted to building the Navy’s ships has only bounced around. In fiscal year 2001, the Navy spent $12 billion on ships. The Presi- dent’s request for ships in 2005 is$11 billion. Why might this be the case

Signatures of Planets in Spatially Unresolved Disks

Main sequence stars are commonly surrounded by debris disks, composed of cold dust continuously replenished by a reservoir of undetected dust-producing planetesimals. In a planetary system with a belt of planetesimals (like the Solar System's Kuiper Belt) and one or more interior giant planets, the trapping of dust particles in the mean motion resonances with the planets can create structure in the dust disk, as the particles accumulate at certain semimajor axes. Sufficiently massive planets may also scatter and eject dust particles out of a planetary system, creating a dust depleted region inside the orbit of the planet. In anticipation of future observations of spatially unresolved debris disks with the Spitzer Space Telescope, we are interested in studying how the structure carved by planets affects the shape of the disk's spectral energy distribution (SED), and consequently if the SED can be used to infer the presence of planets. We numerically calculate the equilibrium spatial density distributions and SEDs of dust disks originated by a belt of planetesimals in the presence of interior giant planets in different planetary configurations, and for a representative sample of chemical compositions. The dynamical models are necessary to estimate the enhancement of particles near the mean motion resonances with the planets, and to determine how many particles drift inside the planet's orbit. Based on the SEDs and predicted $\it{Spitzer}$ colors we discuss what types of planetary systems can be distinguishable from one another and the main parameter degeneracies in the model SEDs.Comment: 40 pages (pre-print form), including 16 figures. Published in ApJ 200

Automated Assessment of Image Quality in 2D Echocardiography Using Deep Learning

Echocardiography is the most used modality for assessing cardiac functions. The reliability of the echocardiographic measurements, however, depends on the quality of the images. Currently, the method of image quality assessment is a subjective process, where an echocardiography specialist visually inspects the images. An automated image quality assessment system is thus required. Here, we have reported on the feasibility of using deep learning for developing such automated quality scoring systems. A scoring system was proposed to include specific quality attributes for on-axis, contrast/gain and left ventricular (LV) foreshortening of the apical view. We prepared and used 1,039 echocardiographic patient datasets for model development and testing. Average accuracy of at least 86% was obtained with computation speed at 0.013ms per frame which indicated the feasibility for real-time deployment

Process qualification and testing of LENS deposited AY1E0125 D-bottle brackets.

The LENS Qualification team had the goal of performing a process qualification for the Laser Engineered Net Shaping{trademark}(LENS{reg_sign}) process. Process Qualification requires that a part be selected for process demonstration. The AY1E0125 D-Bottle Bracket from the W80-3 was selected for this work. The repeatability of the LENS process was baselined to determine process parameters. Six D-Bottle brackets were deposited using LENS, machined to final dimensions, and tested in comparison to conventionally processed brackets. The tests, taken from ES1E0003, included a mass analysis and structural dynamic testing including free-free and assembly-level modal tests, and Haversine shock tests. The LENS brackets performed with very similar characteristics to the conventionally processed brackets. Based on the results of the testing, it was concluded that the performance of the brackets made them eligible for parallel path testing in subsystem level tests. The testing results and process rigor qualified the LENS process as detailed in EER200638525A

Scenario-led modelling of broadleaf forest expansion in Wales

Context Significant changes in the composition and extent of the UK forest cover are likely to take place in the coming decades. Current policy targets an increase in forest area, for example the Welsh Government aims for forest expansion by 2030, and a purposeful shift from non-native conifers to broadleaved tree species, as identified by the UK Forestry Standard Guidelines on Biodiversity. Objectives Using the example of Wales, we aim to generate evidence-based projection of impact of contrasting policy scenarios on the state of forests in the near future, with the view of stimulating debate and aiding decisions concerning plausible outcomes of different policies. Methods We quantified changes in different land use and land cover (LULC) classes in Wales between 2007 and 2015 and used a Multi-layer perceptron-Markov chain ensemble modelling approach to project the state of Welsh forests in 2030 under the current and an alternate policy scenario. Results The current level of expansion and restoration of broadleaf forest in Wales is sufficient to deliver on existing policy goals. We also show effects of a more ambitious afforestation policy on the Welsh landscape. In a key finding, the highest intensity of broadleaf expansion is likely to shift from south-eastern to a more central areas of Wales. Conclusion The study identifies the key predictors of LULC change in Wales. High resolution future land cover simulation maps using these predictors offers an evidence-based tool for forest managers and government officials to test effects of existing and alternative policy scenarios

Non-LTE Model Atmospheres for Late-Type Stars II. Restricted NLTE Calculations for a Solar-Like Atmosphere

We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in Paper I from modern, publicly available, databases, we perform calculations that are confronted with space-based observations of the Sun. At wavelengths longer than about 260 nm, LTE modeling can reproduce quite closely the observed fluxes; uncertainties in the atomic line data account fully for the differences between calculated and observed fluxes. At shorter wavelengths, departures from LTE appear to be important, as our LTE and restricted NLTE calculations differ. Analysis of visible-near infrared Na I and O I lines, two species that produce a negligible absorption in the UV, shows that observed departures from LTE for theses species can be reproduced very accurately with restricted (fixed atmospheric structure) NLTE calculations.Comment: 13 pages, 11 figures, to appear in Ap

Examining the Connections within the Startup Ecosystem: A Case Study of St. Louis

This paper documents the resurgence of entrepreneurial activity in St. Louis by reporting on the collaboration and local learning within the startup community. This activity is happening both between entrepreneurs and between organizations that provide support, such as mentoring and funding, to entrepreneurs. As these connections deepen, the strength of the entrepreneurial ecosystem grows. Another finding from the research is that activity-based events, where entrepreneurs have the chance to use and practice the skills needed to grow their businesses, are most useful. St. Louis provides a multitude of these activities, such as Startup Weekend, 1 Million Cups, Code Until Dawn, StartLouis, and GlobalHack. Some of these are St. Louis specific, but others have nationwide or global operations, providing important implications for other cities

Bodegas subterráneas excavadas en tierra: Características de los suelos en la Ribera del Duero (España)

The ground properties have a decisive effect on the interior conditions, as well as the integrity and durability of the underground wine cellars. The main objective of this paper is to determine the characteristics of the soils where these underground wine cellars have been dug. The results show that most of the soils present very similar plasticity and swelling properties. They are either concentrated in a very specific region of the plasticity chart or present zero plasticity. High-plasticity soils are uncommon, owing to the higher risk of swelling leading to stability problems in the wine cellars. In terms of grain size, silts and sands under 0.4 mm predominate, with a somewhat lower presence of clays. No wine cellars were found that had been dug in earth with very high plasticity or where gravels or clean sands predominate. We recommend that any new wine cellars should be excavated in earth with similar characteristics.<br><br>Las propiedades de la tierra influyen de manera decisiva en las condiciones interiores, la integridad y la durabilidad de las bodegas subterráneas. El principal objetivo del presente artículo es determinar las características de los suelos donde se excavan las bodegas subterráneas. Los resultados demuestran que la mayoría de los suelos presentan unas características de plasticidad y expansibilidad muy similares. Se concentran en una región muy concreta de la carta de plasticidad o presentan plasticidad nula. Los suelos con alta plasticidad no son habituales, debido al mayor riesgo de sufrir expansiones y provocar problemas en las bodegas. En cuanto a granulometría predominan los limos y arenas menores de 0,4 mm, con un contenido en arcillas menor. No se han encontrado bodegas excavadas en terrenos con muy alta plasticidad, ni tampoco donde predominen gravas o arenas limpias. Recomendamos que las nuevas bodegas sean excavadas en terrenos de similares características

Projected effects of disruptions to human immunodeficiency virus (HIV) prevention services during the coronavirus disease 2019 pandemic among Black/African American men who have sex with men in an Ending the HIV Epidemic priority jurisdiction

BACKGROUND: Disruptions in access to in-person human immunodeficiency virus (HIV) preventive care during the coronavirus disease 2019 (COVID-19) pandemic may have a negative impact on our progress towards the Ending the HIV Epidemic goals in the United States. METHODS: We used an agent-based model to simulate HIV transmission among Black/African American men who have sex with men in Mississippi over 5 years to estimate how different reductions in access affected the number of undiagnosed HIV cases, new pre-exposure prophylaxis (PrEP) starts, and HIV incidence. RESULTS: We found that each additional 25% decrease in HIV testing and PrEP initiation was associated with decrease of 20% in the number of cases diagnosed and 23% in the number of new PrEP starts, leading to a 15% increase in HIV incidence from 2020 to 2022. CONCLUSIONS: Unmet need for HIV testing and PrEP prescriptions during the COVID-19 pandemic may temporarily increase HIV incidence in the years immediately after the disruption period