An Analysis of TRL-Based Cost and Schedule Models

The GAO's, NASA's, and the DoD's adoption of the technology readiness level (TRL) scale to improve technology management has led to the emergence of many TRL-based models that are used to monitor technology maturation, mitigate technology program risk, characterize TRL transition times, or model schedule and cost risk for individual technologies, as well as technology systems and portfolios. In the first part of this paper, we develop a theoretical framework to classify those models based on the (often implicit) assumptions they make; we then propose modifications and alternative models to make full use of the assumptions. In the second part, we depart from those assumptions and present a new decision-based framework for cost and schedule joint modeling

It’s All Rocket Science: On the Equivalence of Development Timelines for Aerospace and Nuclear Technologies

Early in the lifecycle of a system development, systems engineers must execute trade studies to allocate resources between different research and development efforts that are developing technologies to be deployed into the system, and they must prepare risk management plans for the selected technologies. We have been developing a statistical model for schedule and cost uncertainty based on a small number of inputs that are quite objective and are already integrated with technology readiness assessment. An algorithm that transforms Technical Maturity (TM) scores from Department of Energy projects into a Technology Readiness Level (TRL) score was created, allowing us to add data from a US Department of Energy to an existing set of data from NASA. We statistically tested whether the two samples (i.e. the DoE and NASA datasets) were randomly drawn from the same population and concluded that the transition times for developing aerospace and nuclear technologies are very similar

Acoustic holography using wavelet transform

We examine here a new method to optimize the performances of the Nearfield Acoustic Holography. This method bas a crucial limitation due to boundary effects (Gibbs phenomenon). During retropropagation, evanescent waves become unstable. The inverse problem is said to be ill-conditioned . We try to solve this problem using a new method in image processing : the wavelet transform .Nous traitons dans cet article d'une nouvelle méthode permettant d'améliorer les performances de l'holograhie acoustique champ proche. L'holographie présente en effet une limitation importante liée à la troncature du plan hologramme qui, créant des effets de bords, pose des problèmes en ce qui concerne la rétropropagation des ondes évanescentes en particulier. Cette étude entre dans le cadre du conditionnement des problèmes inverses mal posés. La méthode utilisée fait appel à un nouvel outil: la transformée par ondelette

Beta Glucan: Health Benefits in Obesity and Metabolic Syndrome

Despite the lack of international agreement regarding the definition and classification of fiber, there is established evidence on the role of dietary fibers in obesity and metabolic syndrome. Beta glucan (β-glucan) is a soluble fiber readily available from oat and barley grains that has been gaining interest due to its multiple functional and bioactive properties. Its beneficial role in insulin resistance, dyslipidemia, hypertension, and obesity is being continuously documented. The fermentability of β-glucans and their ability to form highly viscous solutions in the human gut may constitute the basis of their health benefits. Consequently, the applicability of β-glucan as a food ingredient is being widely considered with the dual purposes of increasing the fiber content of food products and enhancing their health properties. Therefore, this paper explores the role of β-glucans in the prevention and treatment of characteristics of the metabolic syndrome, their underlying mechanisms of action, and their potential in food applications

PGC-1α is Dispensable for Exercise-Induced Mitochondrial Biogenesis in Skeletal Muscle

Exercise confers numerous health benefits, many of which are thought to stem from exercise-induced mitochondrial biogenesis (EIMB) in skeletal muscle. The transcriptional coactivator PGC-1α, a potent regulator of metabolism in numerous tissues, is widely believed to be required for EIMB. We show here that this is not the case. Mice engineered to lack PGC-1α specifically in skeletal muscle (Myo-PGC-1αKO mice) retained intact EIMB. The exercise capacity of these mice was comparable to littermate controls. Induction of metabolic genes after 2 weeks of in-cage voluntary wheel running was intact. Electron microscopy revealed no gross abnormalities in mitochondria, and the mitochondrial biogenic response to endurance exercise was as robust in Myo-PGC-1αKO mice as in wildtype mice. The induction of enzymatic activity of the electron transport chain by exercise was likewise unperturbed in Myo-PGC-1αKO mice. These data demonstrate that PGC-1α is dispensable for exercise-induced mitochondrial biogenesis in skeletal muscle, in sharp contrast to the prevalent assumption in the field

Expression of the alternative oxidase mitigates beta-amyloid production and toxicity in model systems

Mitochondrial dysfunction has been widely associated with the pathology of Alzheimer's disease, but there is no consensus on whether it is a cause or consequence of disease, nor on the precise mechanism(s). We addressed these issues by testing the effects of expressing the alternative oxidase AOX from Ciona intestinalis, in different models of AD pathology. AOX can restore respiratory electron flow when the cytochrome segment of the mitochondrial respiratory chain is inhibited, supporting ATP synthesis, maintaining cellular redox homeostasis and mitigating excess superoxide production at respiratory complexes I and III. In human HEK293-derived cells, AOX expression decreased the production of beta-amyloid peptide resulting from antimycin inhibition of respiratory complex III. Because hydrogen peroxide was neither a direct product nor substrate of AOX, the ability of AOX to mimic antioxidants in this assay must be indirect. In addition, AOX expression was able to partially alleviate the short lifespan of Drosophila models neuronally expressing human beta-amyloid peptides, whilst abrogating the induction of markers of oxidative stress. Our findings support the idea of respiratory chain dysfunction and excess ROS production as both an early step and as a pathologically meaningful target in Alzheimer's disease pathogenesis, supporting the concept of a mitochondrial vicious cycle underlying the disease. (C) 2016 The Authors. Published by Elsevier Inc.Peer reviewe

ELN and FBN2 gene variants as risk factors for two sports-related musculoskeletal injuries

The proteins ELN and FBN2 are important in extracellular matrix function. The ELN rs2071307 and FBN2 rs331079 gene variants have been associated with soft tissue pathologies. We aimed to determine whether these variants were predisposing factors for both Achilles tendinopathy (AT) and anterior cruciate ligament (ACL) ruptures. For the AT study, 135 cases (TEN group) and 239 asymptomatic controls were recruited. For the ACL rupture study our cohort consisted of 141 cases (ACL group) and 219 controls. Samples were genotyped for both the ELN rs2071307 and FBN2 rs331079 variants using TaqMan assays. Analysis of variance and chi-squared tests were used to determine whether either variant was associated with AT or ACL rupture with significance set at p<0.05. The GG genotype of the FBN2 variant was significantly over-represented within the TEN group (p=0.035; OR=1.83; 95% CI 1.04–3.25) compared to the CON group. We also found that the frequency of the G allele was significantly different between the TEN (p=0.017; OR=1.90; 95% CI 1.11–3.27) and ACL groups (p=0.047; OR=1.76; 95% CI 1.00–3.10) compared to controls. The ELN rs207137 variant was not associated with either AT or ACL rupture. In conclusion, DNA sequence variation within the FBN2 gene is associated with both AT and ACL rupture