Machine Learning Outperforms ACC / AHA CVD Risk Calculator in MESA.

Background Studies have demonstrated that the current US guidelines based on American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort Equations Risk Calculator may underestimate risk of atherosclerotic cardiovascular disease ( CVD ) in certain high-risk individuals, therefore missing opportunities for intensive therapy and preventing CVD events. Similarly, the guidelines may overestimate risk in low risk populations resulting in unnecessary statin therapy. We used Machine Learning ( ML ) to tackle this problem. Methods and Results We developed a ML Risk Calculator based on Support Vector Machines ( SVM s) using a 13-year follow up data set from MESA (the Multi-Ethnic Study of Atherosclerosis) of 6459 participants who were atherosclerotic CVD-free at baseline. We provided identical input to both risk calculators and compared their performance. We then used the FLEMENGHO study (the Flemish Study of Environment, Genes and Health Outcomes) to validate the model in an external cohort. ACC / AHA Risk Calculator, based on 7.5% 10-year risk threshold, recommended statin to 46.0%. Despite this high proportion, 23.8% of the 480 "Hard CVD " events occurred in those not recommended statin, resulting in sensitivity 0.76, specificity 0.56, and AUC 0.71. In contrast, ML Risk Calculator recommended only 11.4% to take statin, and only 14.4% of "Hard CVD " events occurred in those not recommended statin, resulting in sensitivity 0.86, specificity 0.95, and AUC 0.92. Similar results were found for prediction of "All CVD " events. Conclusions The ML Risk Calculator outperformed the ACC/AHA Risk Calculator by recommending less drug therapy, yet missing fewer events. Additional studies are underway to validate the ML model in other cohorts and to explore its ability in short-term CVD risk prediction

Problems with Fitting to the Power-Law Distribution

This short communication uses a simple experiment to show that fitting to a power law distribution by using graphical methods based on linear fit on the log-log scale is biased and inaccurate. It shows that using maximum likelihood estimation (MLE) is far more robust. Finally, it presents a new table for performing the Kolmogorov-Smirnof test for goodness-of-fit tailored to power-law distributions in which the power-law exponent is estimated using MLE. The techniques presented here will advance the application of complex network theory by allowing reliable estimation of power-law models from data and further allowing quantitative assessment of goodness-of-fit of proposed power-law models to empirical data.Comment: 4 pages, 1 figure, 2 table

CheMin-V: A Definitive Mineralogy Instrument for Landed Science on Venus

An X-ray diffraction instrument is described that will provide quantitative mineralogical analyses of up to 4 individual samples of Venus regolith in ~1 hour

Water content of the Martian soil: Laboratory simulations of reflectance spectra

Reflectance spectra from the surface of Mars collected by instruments such as the imaging spectrometer (ISM) onboard the 1988 Soviet Phobos 2 spacecraft exhibit strong 3 μm absorption features that have long been attributed to hydrated materials on the Martian surface. This interpretation is consistent with a series of chemical weathering models suggesting an abundance of palagonites, clays, and other hydrated mineral phases in the Martian fines. Little work, however, has been done to constrain the actual water content of the Martian surface materials. New laboratory data presented here show that the ISM spectra are consistent with up to 4% water by weight and that the deep hydration features observed in the spacecraft data could be due to less than 0.5% water if the hydrated phases are present in the form of grain coatings. These results are consistent with the somewhat uncertain in situ measurements obtained by the Viking landers which yielded approximately 2 wt % water from samples heated to 500°C. On the basis of this work, we expect the TEGA instrument on the Mars '98 lander to find less than 4% adsorbed or bound water in the upper few centimeters of the Martian soil

Corporate Application Integration: Challenges, Opportunities, and Implementation Strategies

In recent years, corporate applications such as enterprise resource planning (ERP) systems, supply chain management (SCM) systems, customer relationship management (CRM) systems, sales force automation (SFA), and other corporate-level information systems have received a great deal of attention from large business enterprises. These applications have been around for about a decade now, and in that time their producers have refined them and perfected them to the point where they can be considered developmentally mature. At the same time, vendors have continued to introduce new products that have moved corporate applications toward a higher level of integration, both technically and organizationally. However, these higher levels of integration have brought with them complex technical, organizational, cultural, political, and legal issues that have made the integration process a very challenging task. This paper reviews relevant current literature, discusses several perspectives of corporate application integration, and points out potential opportunities and cludlenges inherent in the integration process. Risk reduction strategies and opportunities provided by some newly developed technologies (e.g., software agents) are also discussed

Stability of hydroxylated minerals on Mars: A study on the effects of exposure to ultraviolet radiation

The density and composition of the Martian atmosphere allow solar ultraviolet photons with wavelengths as short as 190 nm to reach the surface. We investigate the hypothesis that this UV radiation is capable of inducing the release of water from iron oxyhydroxide minerals resulting in the formation of oxide phases. These experiments, which utilize a quadrupole mass spectrometer to monitor the water vapor pressure above mineral samples during cyclic exposure to ultraviolet radiation, offer 5 to 6 orders of magnitude greater sensitivity than previous attempts to establish and quantify this process. We find no evidence that UV photons are capable of liberating OH from the crystal lattice of minerals, and we set a minimum ultraviolet radiation-induced dehydroxylation time of 10^8 years for removal of this structural OH from mineral particles at the Martian surface. The overturning timescales for surface fines are likely to be shorter than this lower limit for exposure time. Thus we conclude that UV-stimulated dehydroxylation is not a significant process at the Martian surface and that iron oxyhydroxides, if formed during an earlier water-rich environment, should still be found on Mars today. The lack of clear evidence for iron oxyhydroxides at the Martian surface further suggests that Mars' surface was never warm and wet for a long enough period of time for Earth-like weathering to have occurred

Photoelastic investigation of stresses of a square beam under compression

Call number: LD2668 .R4 1965 Y4

IMPRINTING POLYMERFILM ON PATTERNED SUBSTRATE

A method of applying a pattern on a topography includes first applying a polymer film to an elastormer member, such as PDMS, to form a pad. The pad is then applied to a substrate having a varying topography under pressure. The polymer film is transferred to the substrate due to the plastic deformation of the polymer film under pressure compared to the elastic deformation of the PDMS member pulls away from the polymer layer, thereby depositing the polymer layer, thereby depositing the polymer layer upon the substrate

Optimization Lactic Acid Production from Molasses Renewable Raw Material through Response Surface Methodology with Lactobacillus Casei M-15

AbstractLactic acid is one of the functional and valuable compounds utilized in food, pharmaceutical and chemical industries while Poly lactic acid (PLA) is a biodegradable polymer that has a variety of applications. In recent years, microbial conversion of renewable raw materials has become an important objective in industrial biotechnology. Sugarcane molasses can be considered as potential renewable raw materials in PLA production. The objective of this study is to optimized fermentation medium and conditions to obtain maximum lactic acid production and Colony Forming Unit (log CFU/mL) through response surface methodology (RSM). The maximum lactic acid production (38.33%) and log CFU/mL (8.30) by Lactobacillus casei M-15 was under 3.82% of molasses and 8.02% of inoculum level within 24 hr at 37°C respectively. This process will be advantageous for increasing yields of lactic acid and enhancing productivity by optimization technique. Moreover, it can reduce waste disposal and pollution and can selectively produce by sustainable agriculture such as agriculture material. In addition, the high-performance of lactic acid-producing microorganisms, qualified renewable raw materials and effective fermentation processes will be benefit for bioplastic technologies