Gasoline Prices: Cyclical Trends and Market Developments

Gasoline prices experience volatility often credited to fluctuations in the crude oil market, but gasoline is subject to its own supply and demand pressures. Cyclical trends such as seasonal changes in refining costs, production adjustments, and changes in demand contribute to gasoline price movements over a typical year. Recently, however, market developments not influenced by seasonal fluctuations have affected prices. From 2010 to 2014, increased access to cost-advantaged domestic sources of crude oil has expanded domestic gasoline production, and evolving consumption patterns in the United States and abroad have altered both import and export demand. Between January 2005 and September 2008, the producer price index for gasoline trended generally higher. (See chart 1.) The onset of the Great Recession pressured producer prices lower in the fourth quarter of 2008, a 67.8-percent drop, before prices started to rebound in early 2009. By mid-2011, prices reached prerecession levels and remained in a tight range before dropping more than 50 percent in the latter half of 2014 and early 2015. This Beyond the Numbers article examines the many factors that contributed to shifting producer gasoline prices from 2005 through 2014

The Impact of Nutrition-Teaching Self-Efficacy on Daily Fruit and Vegetable Intake

Lack of fruit and vegetable (FV) consumption is directly linked to the prevalence of obesity and chronic disease in the United States. The USDA Fresh Fruit and Vegetable Program (FFVP) offers elementary school teachers access to healthy foods as part of the public school classroom experience. The purpose of this study---which was based on self-efficacy theory and the socio-ecological model---was to examine if an association exists between selected factors: (a) daily fruit and vegetable consumption, training status in the USDA Fresh Fruit and Vegetable Program (FFVP), and an established school nutrition policy and (b) nutrition-teaching self-efficacy (NTSE) among elementary school teachers who participated in the FFVP. Using an online survey, 66 teachers out of 114 (58% response rate) completed a 26-question survey adapted from the Nutrition-Teaching Self-Efficacy Scale and the National Cancer Institute\u27s Food Attitude and Behavior Survey. Based on the results of the chi-square test of association (p = 0.031), an association between daily FV intake and NTSE among teachers involved in the USDA FFVP was confirmed. The odds of having high NTSE are 3.45 higher in those who consume more than 3 cups of combined FV each day (p = 0.029). There were no significant associations between NTSE and FFVP training and established school nutrition policy. The social change implication of this study is that healthier, confident teachers build healthier school environments and create the impetus for increasing FV consumption in the community at large, thereby helping to reduce the risk of obesity and chronic diseases

Static source locations for four nozzles mounted on a J-85 engine

The test nozzles included a round 17.5 in. diameter variable flap ejector (VFE) nozzle, a round 'stovepipe' nozzle, and a 104 tube suppressor nozzle operated both with and without an ejector shroud. The velocities tested ranged from 600 to 1600 fps at an approximate total temperature of 1400 R. The axial position of the noise sources during static operation was determined by jet velocity, Strouhal number, and direction of propagation. The velocity dependence was more evident for the 104 tube suppressor nozzle than for the conical nozzles tested. The results for both the VFE conical nozzle and the stovepipe conical nozzle indicate source locations to be much closer to the jet exit plane than expected. Corrections for near field effects were found to differ slightly for each nozzle tested. The corrections presented are simply the differences between the measured near field levels and the required near field levels if spherical spreading is assumed from source to far field

Non-Isotropic Material Distribution Topology Optimization for Fused Deposition Modeling Products

Mechanical properties of products produced with the Fused Deposition Modeling (FDM) process are known to be dependent on bead direction, especially when short fiber reinforcement is added to the polymer filament feedstock. As a result, the structural performance of fiber-filled FDM parts is expected to be improved by simultaneously computing preferred deposition directions while optimizing the internal support structure. This paper presents a topology optimization method for computing the material distribution within a fiber-reinforced polymer composite FDM part that incorporates the non-isotropic mechanical properties of the bead structure. Unlike the well-established homogenization topology optimization method which determines pointwise orthotropic properties by increasing the complexity of the design problem, our approach takes advantage of the simplicity of the SIMP method where the underlying orthotropic orientation is assumed. Computed results show the effect that the orientation of fiber filled bead orthotropic microstructure has on part topology for 2D FDM parts.Mechanical Engineerin

Interface Stability During Rapid Directional Solidification

Engineering and Applied Science

Experimental Test of Morphological Stability Theory for a Planar Interface During Rapid Solidification

We report a parameter-free test of the theory predicting the critical solute concentration that destabilizes a planar solid-liquid interface in the high-velocity regime where nonequilibrium interface kinetics are important. Rapid solidification following pulsed laser melting was used to make metastable solid solutions of silicon-tin. Rutherford backscattering spectrometry and transmission electron microscopy were used to measure the breakdown concentration. Samples remained microsegregation free with near perfect crystallinity at tin concentrations up to 10 times the maximum equilibrium solubility and 100 times that predicted by linear stability theory with local interfacial equilibrium. These measurements, covering velocities from 1 to 10 m/s, agree with the predictions of linear stability theory when the latter incorporates a velocity-dependent partition coefficient and a thermodynamically consistent kinetic liquidus, and contains no adjustable parameters. We also report a systematic increase of the breakdown concentration with increasing deviation from steady-state conditions, which is not addressed by current stability theories, parametrized by the concentration gradient just prior to breakdown.Engineering and Applied Science

Viability of brown trout embryos positively linked to melanin-based but negatively to carotenoid-based colours of their fathers

‘Good-genes’ models of sexual selection predict significant additive genetic variation for fitness-correlated traits within populations to be revealed by phenotypic traits. To test this prediction, we sampled brown trout (Salmo trutta) from their natural spawning place, analysed their carotenoid-based red and melanin-based dark skin colours and tested whether these colours can be used to predict offspring viability. We produced half-sib families by in vitro fertilization, reared the resulting embryos under standardized conditions, released the hatchlings into a streamlet and identified the surviving juveniles 20 months later with microsatellite markers. Embryo viability was revealed by the sires' dark pigmentation: darker males sired more viable offspring. However, the sires' red coloration correlated negatively with embryo survival. Our study demonstrates that genetic variation for fitness-correlated traits is revealed by male colour traits in our study population, but contrary to predictions from other studies, intense red colours do not signal good genes

Knowledge management infrastructure to support quality improvement: A qualitative study of maternity services in four European hospitals

The influence of multilevel healthcare system interactions on clinical quality improvement (QI) is still largely unexplored. Through the lens of knowledge management (KM) theory, this study explores how hospital managers can enhance the conditions for clinical QI given the specific multilevel and professional interactions in various healthcare systems. The research used an in-depth multilevel analysis in maternity departments in four purposively sampled European hospitals (Portugal, England, Norway and Sweden). The study combines analysis of macro-level policy documents and regulations with semi-structured interviews (96) and non-participant observations (193 hours) of hospital and clinical managers and clinical staff in maternity departments. There are four main conclusions: First, the unique multilevel configuration of national healthcare policy, hospital management and clinical professionals influence the development of clinical QI efforts. Second, these different configurations provide various and often insufficient support and guidance which affect professionals’ action strategies in QI efforts. Third, hospital managers’ opportunities and capabilities for developing a consistent KM infrastructure with reinforcing enabling conditions which merge national policies and guidelines with clinical reality is crucial for clinical QI. Fourth, understanding these interrelationships provides an opportunity for improvement of the KM infrastructure for hospital managers through tailored interventions

Neurochemical Aftermath of Repetitive Mild Traumatic Brain Injury

IMPORTANCE: Evidence is accumulating that repeated mild traumatic brain injury (mTBI) incidents can lead to persistent, long-term debilitating symptoms and in some cases a progressive neurodegenerative condition referred to as chronic traumatic encephalopathy. However, to our knowledge, there are no objective tools to examine to which degree persistent symptoms after mTBI are caused by neuronal injury. OBJECTIVE: To determine whether persistent symptoms after mTBI are associated with brain injury as evaluated by cerebrospinal fluid biochemical markers for axonal damage and other aspects of central nervous system injury. DESIGN, SETTINGS, AND PARTICIPANTS: A multicenter cross-sectional study involving professional Swedish ice hockey players who have had repeated mTBI, had postconcussion symptoms for more than 3 months, and fulfilled the criteria for postconcussion syndrome (PCS) according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) matched with neurologically healthy control individuals. The participants were enrolled between January 2014 and February 2016. The players were also assessed with Rivermead Post Concussion Symptoms Questionnaire and magnetic resonance imaging. MAIN OUTCOMES AND MEASURES: Neurofilament light protein, total tau, glial fibrillary acidic protein, amyloid β, phosphorylated tau, and neurogranin concentrations in cerebrospinal fluid. RESULTS: A total of 31 participants (16 men with PCS; median age, 31 years; range, 22-53 years; and 15 control individuals [11 men and 4 women]; median age, 25 years; range, 21-35 years) were assessed. Of 16 players with PCS, 9 had PCS symptoms for more than 1 year, while the remaining 7 returned to play within a year. Neurofilament light proteins were significantly increased in players with PCS for more than 1 year (median, 410 pg/mL; range, 230-1440 pg/mL) compared with players whose PCS resolved within 1 year (median, 210 pg/mL; range, 140-460 pg/mL) as well as control individuals (median 238 pg/mL, range 128-526 pg/mL; P = .04 and P = .02, respectively). Furthermore, neurofilament light protein concentrations correlated with Rivermead Post Concussion Symptoms Questionnaire scores and lifetime concussion events (ρ = 0.58, P = .02 and ρ = 0.52, P = .04, respectively). Overall, players with PCS had significantly lower cerebrospinal fluid amyloid-β levels compared with control individuals (median, 1094 pg/mL; range, 845-1305 pg/mL; P = .05). CONCLUSIONS AND RELEVANCE: Increased cerebrospinal fluid neurofilament light proteins and reduced amyloid β were observed in patients with PCS, suggestive of axonal white matter injury and amyloid deposition. Measurement of these biomarkers may be an objective tool to assess the degree of central nervous system injury in individuals with PCS and to distinguish individuals who are at risk of developing chronic traumatic encephalopathy

Correlated fragile site expression allows the identification of candidate fragile genes involved in immunity and associated with carcinogenesis

Common fragile sites (cfs) are specific regions in the human genome that are particularly prone to genomic instability under conditions of replicative stress. Several investigations support the view that common fragile sites play a role in carcinogenesis. We discuss a genome-wide approach based on graph theory and Gene Ontology vocabulary for the functional characterization of common fragile sites and for the identification of genes that contribute to tumour cell biology. CFS were assembled in a network based on a simple measure of correlation among common fragile site patterns of expression. By applying robust measurements to capture in quantitative terms the non triviality of the network, we identified several topological features clearly indicating departure from the Erdos-Renyi random graph model. The most important outcome was the presence of an unexpected large connected component far below the percolation threshold. Most of the best characterized common fragile sites belonged to this connected component. By filtering this connected component with Gene Ontology, statistically significant shared functional features were detected. Common fragile sites were found to be enriched for genes associated to the immune response and to mechanisms involved in tumour progression such as extracellular space remodeling and angiogenesis. Our results support the hypothesis that fragile sites serve a function; we propose that fragility is linked to a coordinated regulation of fragile genes expression.Comment: 18 pages, accepted for publication in BMC Bioinformatic