127 research outputs found

    A new proof of scattering below the ground state for the non-radial focusing NLS

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    We revisit the scattering result of Duyckaerts, Holmer, and Roudenko for the non-radial H˙1/2\dot H^{1/2}-critical focusing NLS. By proving an interaction Morawetz inequality, we give a simple proof of scattering below the ground state in dimensions d≥3d\geq 3 that avoids the use of concentration compactness.Comment: 14 page

    4,000: A Rhetorical Analysis of FIFA’s Media Response to Human Rights Abuses in Preparation for the 2022 World Cup

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    On September 25, 2013 The Guardian released a report that alleged human rights abuses at the construction sites for the 2022 FIFA World Cup in Qatar. Further investigation from the International Trade Union Confederation (ITUC) has estimated that over 4,000 migrant workers will die before a soccer ball is kicked in 2022. Subsequent reports claim that the abuses and deaths have continued since the initialGuardian report. Despite these reports, as of December 2014, the 2022 FIFA World Cup will still take place as planned. Using rhetorical analysis based on Michel Foucault’s method of genealogy, this research analyzes how FIFA uses rhetoric in the media to maintain organizational power in the face of these human rights abuse allegations. The findings indicate that FIFA’s use of contradictory rhetoric and distancing rhetoric regarding their responsibility towards the workers’ rights problems helps to establish and maintain a favorable subjective truth about FIFA’s role the situation. Inoculation theory is applied to further explain how this sort of rhetoric helps FIFA to maintain power and remain inactive on the human rights issue

    Covariability in the Monthly Mean Convective and Radiative Diurnal Cycles in the Amazon

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    The diurnal cycle of convective clouds greatly influences the radiative energy balance in convectively active regions of Earth, through both direct presence, and the production of anvil and stratiform clouds. Previous studies show that the frequency and properties of convective clouds can vary on monthly timescales as a result of variability in the monthly mean atmospheric state. Furthermore, the radiative budget in convectively active regions also varies by up to 7 Wm-2 in convectively active regions. These facts suggest that convective clouds connect atmospheric state variability and radiation variability beyond clear sky effects alone. Previous research has identified monthly covariability between the diurnal cycle of CERES-observed top-of-atmosphere radiative fluxes and multiple atmospheric state variables from reanalysis over the Amazon region. ASVs that enhance (reduce) deep convection, such as CAPE (LTS), tend to shift the daily OLR and cloud albedo maxima earlier (later) in the day by 2-3 hr. We first test the analysis method using multiple reanalysis products for both the dry and wet seasons to further investigate the robustness of the preliminary results. We then use CloudSat data as an independent cloud observing system to further evaluate the relationships of cloud properties to variability in radiation and atmospheric states. While CERES can decompose OLR variability into clear sky and cloud effects, it cannot determine what variability in cloud properties lead to variability in the radiative cloud effects. Cloud frequency, cloud top height, and cloud microphysics all contribute to the cloud radiative effect, all of which are observable by CloudSat. In addition, CloudSat can also observe the presence and variability of deep convective cores responsible for the production of anvil clouds. We use these capabilities to determine the covariability of convective cloud properties and the radiative diurnal cycle

    Observations of atmospheric rivers with CloudSat CPR and Aqua AMSR-E

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    Includes bibliographical references."Atmospheric rivers" are filamentary water vapor structures, occurring primarily over oceans, thousands of kilometers long that form along the leading edge of cold fronts. These "rivers" are an important link between weather and climate by transporting large amounts of moisture (on the order of 108kgs-1) through the middle latitude regions and causing heavy precipitation events along coastal regions. The CloudSat satellite, launched 28 April 2006, is designed to measure vertical cloud structure and fill a long-existing gap in satellite observations. CloudSat and Aqua observed 22 river events (with multiple overpasses for each river) over a period from November 2006 to April 2007. In this project, CloudSat CPR observations of cloud location and cloud type are used along with moisture observations from Aqua AMSR-E to create a preliminary average profile of vertical cloud structure within atmospheric rivers. The CloudSat observations (using Aqua moisture and precipitation measurements as references) are first presented for case studies of four river events out of the total 22 events. The observations show deep convective (vertical extent more than 7km) and nimbostratus cloud (vertical extent more than 4km) bands more than 100km in horizontal width occurring in three of the four cases, and shallow convection (vertical extent less than 4km) occurring in the fourth case. Deep layer clouds occur most frequently during the river's early and middle stages, and these deep clouds usually erode into low and (sometimes) high cloud bands in the river's later life. The CloudSat measurements are then combined into composite frequency plots to show the typical cloud locations within and near the river with respect to the river's water vapor structure. Frequency plots are presented for all 92 overpasses along with categories of overpasses based on time of occurrence within the rivers' life spans to give a preliminary time evolution of cloud structure. Then, scatter plots comparing moisture structure properties with cloud structure properties are displayed to show any possible relationship between moisture and clouds. Finally, some statistics about the frequency of occurrence of different cloud types within the rivers are presented.This work was sponsored by the following: NOAA/NESDIS Grant NA17RJ1228, entitled "Applications of satellite altimetry data to statistical and simplified dynamical tropical cyclone intensity forecast models"; NOAA/NESDIS Grant NA17RJ1228, entitled "A satellite analysis of atmospheric rivers"; and NASA Grant NAS5-99237, entitled "CloudSat"

    National Football League Skilled and Unskilled Positions Vary in Opportunity and Yield in Return to Play After an Anterior Cruciate Ligament Injury.

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    BACKGROUND: Anterior cruciate ligament (ACL) injuries pose a significant risk to the careers of players in the National Football League (NFL). The relationships between draft round and position on return to play (RTP) among NFL players are not well understood, and the ability to return to preinjury performance levels remains unknown for most positions. PURPOSE: To test for differences in RTP rates and changes in performance after an ACL injury by position and draft round. We hypothesized that skilled positions would return at a lower rate compared to unskilled positions. We further hypothesized that early draft-round status would relate to a greater rate of RTP and that skilled positions and a lower draft round would correlate with decreased performance for players who return to sport. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Utilizing a previously established database of publicly available information regarding ACL tears among NFL players, athletes with ACL tears occurring between the 2010 and 2013 seasons were identified. Generalized linear models and Kaplan-Meier time-to-event models were used to test the study hypotheses. RESULTS: The overall RTP rate was 61.7%, with skilled players and unskilled players returning at rates of 64.1% and 60.4%, respectively (P = .74). Early draft-round players and unskilled late draft-round players had greater rates of RTP compared to skilled late draft-round players and both unskilled and skilled undrafted free agents (UDFAs). Skilled early draft-round players constituted the only cohort that played significantly fewer games after an injury. Unskilled UDFAs constituted the only cohort to show a significant increase in the number of games started and ratio of games started to games played, starting more games in which they played, after an injury. CONCLUSION: Early draft-round and unskilled players were more likely to return compared to their later draft-round and skilled peers. Skilled early draft-round players, who displayed relatively high rates of RTP, constituted the only cohort to show a decline in performance. Unskilled UDFAs, who exhibited relatively low rates of RTP, constituted the only cohort to show an increase in performance. The significant effect of draft round and position type on RTP may be caused by a combination of differences in talent levels and in opportunities given to returning to play

    The California Planet Survey. I. Four New Giant Exoplanets

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    We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne spectroscopy. Their orbital parameters span wide ranges of planetary minimum mass (M sin i = 0.38-1.9 M(Jup)), orbital period (P = 2.87-11.5 yr), semimajor axis (a = 2.1-5.2 AU), and eccentricity (e = 0.02-0.41). HD 34445 b (P = 2.87 yr, M sin i = 0.79 MJup, e = 0.27) is a massive planet orbiting an old, G-type star. We announce a planet, HD 126614 Ab, and an M dwarf, HD 126614 B, orbiting the metal-rich star HD 126614 (which we now refer to as HD 126614 A). The planet, HD 126614 Ab, has minimum mass M sin i = 0.38 MJup and orbits the stellar primary with period P = 3.41 yr and orbital separation a = 2.3 AU. The faint M dwarf companion, HD 126614 B, is separated from the stellar primary by 489 mas (33 AU) and was discovered with direct observations using adaptive optics and the PHARO camera at Palomar Observatory. The stellar primary in this new system, HD 126614 A, has the highest measured metallicity ([ Fe/ H] = + 0.56) of any known planet-bearing star. HD 13931 b (P = 11.5 yr, M sin i = 1.88 MJup, e = 0.02) is a Jupiter analog orbiting a near solar twin. Gl 179 b (P = 6.3 yr, M sin i = 0.82 M(Jup), e = 0.21) is a massive planet orbiting a faint M dwarf. The high metallicity of Gl 179 is consistent with the planet-metallicity correlation among M dwarfs, as documented recently by Johnson & Apps.NSF AST-0702821NASA NNX06AH52GMcDonald Observator
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