1,598 research outputs found
Deep flaws in weldments of aluminum and titanium
Surface flawed specimens of 2219-T87 and 6Al-4V STA titanium weldments were tested to determine static failure modes, failure strength, and fatigue flaw growth characteristics. Thicknesses selected for this study were purposely set at values where, for most test conditions, abrupt instability of the flaw at fracture would not be expected. Static tests for the aluminum weldments were performed at room, LN2 and LH2 temperatures. Titanium static tests for tests were performed at room and LH2 temperatures. Results of the static tests were used to plot curves relating initial flaw size to leakage- or failure-stresses (i.e. "failure" locus curves). Cyclic tests, for both materials, were then performed at room temperature, using initial flaws only slightly below the previously established failure locus for typical proof stress levels. Cyclic testing was performed on pairs of specimens, one with and one without a simulated proof test cycle. Comparisons were made then to determine the value and effect of proof testing as affected by the various variables of proof and operating stress, flaw shape, material thickness, and alloy
Spring 2012 Georgia Journal of Public Policy - Introduction
This is the second volume of the annual Georgia Journal of Public Policy, and as the editor I would like to use these introductory comments to discuss three things. First, I am happy to report on how the journal’s first issue performed in terms of readership. Second, I will introduce a new section of the journal that features undergraduate student research on policy in Georgia. Finally, I will discuss future plans for the journal
Satisfaction With Local Conditions and the Intention To Move
The recent economic downturn has presented many challenges to local communities and policy- makers. Foreclosed properties, job losses, and other challenges that local residents face can threaten the economic viability of local communities. Another consequence of the economic downturn is decreased government budgets, forcing policymakers to make decisions about how to allocate scarce resources effectively. When making decisions about local and regional policy, it would be useful to know how local characteristics contribute to the decisions residents make about whether to remain in a local community or to relocate. Exhibits 1 through 4 present maps created to investigate the relationship between residents’ perceptions of local conditions and the intentions of residents to move. The maps are of the ZIP Codes in the five core counties in the Atlanta metropolitan area (Clayton, Cobb, DeKalb, Fulton, and Gwinnett), combined with data from a public opinion survey conduced by the A.L. Burruss Institute of Public Service at Kennesaw State University
The Impact of Prolonged Nomination Contests on Presidential Candidate Evaluations and General Election Vote Choice: The Case of 2008
The fact that political parties hold competitive nomination contests that require voters to choose among multiple candidates leaves open the possibility that the contest itself could damage the prospects of an eventual nominee. In this study, we employ the American National Election Study panel survey data from the 2008 U.S. presidential election to assess the impact of the Democratic Party nomination process on candidate evaluations and general election vote preference. We find evidence that Barack Obama had greater difficulty uniting his party than his Republican counterpart due to the fact that Clinton voters were slow to coalesce around Obama. These supporters failed to report higher levels of favorability until Clinton conceded the race in the summer, while Huckabee and Romney voters were seen rallying to their party\u27s nominee in the spring. In the end, many Clinton primary voters either abstained from voting in November or crossed over to support the Republican nominee
Noise-free high-efficiency photon-number-resolving detectors
High-efficiency optical detectors that can determine the number of photons in
a pulse of monochromatic light have applications in a variety of physics
studies, including post-selection-based entanglement protocols for linear
optics quantum computing and experiments that simultaneously close the
detection and communication loopholes of Bell's inequalities. Here we report on
our demonstration of fiber-coupled, noise-free, photon-number-resolving
transition-edge sensors with 88% efficiency at 1550 nm. The efficiency of these
sensors could be made even higher at any wavelength in the visible and
near-infrared spectrum without resulting in a higher dark-count rate or
degraded photon-number resolution.Comment: 4 pages, 4 figures Published in Physical Review A, Rapid
Communications, 17 June 200
Health Coaching in Primary Care: A Pilot Study
Undergraduate Research Opportunity Program (UROP)http://deepblue.lib.umich.edu/bitstream/2027.42/116124/1/Health_Coaching_In_Primary_Care.pd
Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle
Citation: Samii, S. S., Wallace, N., Nagaraja, T. G., Engstrom, M. A., Miesner, M. D., Armendariz, C. K., & Titgemeyer, E. C. (2016). Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle. Journal of Animal Science, 94(8), 3420-3430. doi:10.2527/jas2016-0455Previous in vitro data showed that Fusobacterium necrophorum was inhibited by limonene. We further evaluated effects of limonene on growth of F. necrophorum in vitro as well as on ruminal concentrations of F. necrophorum in vivo. With in vitro cultivation in anaerobic brain-heart infusion broth, limonene decreased growth of F. necrophorum. Thymol also reduced growth of F. necrophorum, but it was less effective than limonene. Tylosin effectively reduced growth of F. necrophorum in vitro. Although the response over fermentation times and concentrations of antimicrobials differed somewhat between tylosin and limonene, the 2 antimicrobial agents yielded similar inhibitory effects on growth of F. necrophorum at concentrations ranging from 6 to 24 mg/L. The effects of limonene on ruminal F. necrophorum concentration in vivo were tested in 7 ruminally cannulated heifers (225 kg initial BW) used in a 7 × 4 Youden square design. Treatments included: 1) control, 2) limonene at 10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, and 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples of ruminal contents were collected before treatment initiation and after 4, 7, and 10 d of treatment for measuring F. necrophorum by the most probable number method using selective culture medium. Limonene linearly decreased (P = 0.03) ruminal F. necrophorum concentration, with the lowest concentration achieved with 40 mg of limonene/kg dietary DM. Limonene tended (P ? 0.07) to linearly reduce ruminal molar proportions of propionate and valerate while tending to linearly increase (P ? 0.10) those of butyrate and 2-methyl butyrate. Limonene did not affect ruminal NH3 concentrations or degradation rates of lysine. Neither CRINA-L (P = 0.52) nor tylosin (P = 0.19) affected ruminal F. necrophorum concentrations. CRINA-L significantly decreased ruminal concentrations of NH3 and molar proportions of 3-methyl butyrate, whereas tylosin significantly decreased molar proportions of propionate while increasing those of butyrate and tending to increase those of acetate. Limonene supplementation reduced ruminal concentrations of F. necrophorum suggesting that it may have the potential to reduce the prevalence of liver abscesses, although further research is needed to assess the effect of limonene in feedlot cattle. © 2016 American Society of Animal Science. All rights reserved
Impacts of forestry planting on primary production in upland lakes from north-west Ireland
Planted forests are increasing in many upland regions world-wide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). 210Pb dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (δ13C) and nitrogen (δ15N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to six-fold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (β-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilisation and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance
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
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