520 research outputs found

    Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers

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    In this supplementary material, we recollect, for reader's convenience, the general scheme of suggested multiscale model (Sec. 1), and basic informations about approaches used for pilot study: a detailed description of the interaction model (Sec. 2) and dynamical methods used for the dark dynamics step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition, a detailed description of the treatment of radiative processes is also given (Sec. 4).Comment: supplementary material for parent paper; 9 pages, 1 figure; corrected formulae and misleading notation in Sec.4 (pages 7 and 8

    International tourism later in life : Innovation Theory related to benefits gained

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    As the Baby Boomer cohort (1946-1964) within the United States age, the travel industry will demand a shift in services provided to the senior market. Although there are many research studies on older adults and others on tourism behaviors, little research has considered the influence of innovation in the travel behaviors of this generation as they age. Innovation Theory (Nimrod & Kleiber, 2007) considers the role of innovation as an opportunity to create a challenging and meaningful life through a growth mechanism. In this study, innovation is conceived as new experiences older adults acquire during international tourism.   In an effort to test the reliability of Innovation Theory, the current study adapted a previous study (Nimrod & Rotem, 2010) which examined Israeli retirees' tourism behaviors with a sample of North Carolina Baby Boomers. Researchers collected 150 questionnaires completed by North Carolina residents who met the criteria of being born between 1946 and 1964 and traveling internationally within the last three years. The current study confirmed findings from the previous study resulting in three clusters of innovators as well as supporting Innovation Theory. The current study also included analyses of variance to compare clusters of travelers according to the benefits of their travel as well as the frequency of their participation in destination activities.   Findings indicated that North Carolina Baby Boomers were similar to older adults in Israel related to innovation in international travel behaviors. Findings from the current research expand the literature on theories of aging to consider the emergent generation of older adults. Further, findings may inform the tourism industry about appropriate services to a new market segmentation of senior travelers.  M.S

    Recruitment Strategies and the Retention of Obese Urban Racial/Ethnic Minority Adolescents in Clinical Trials: The FIT Families Project, Michigan, 2010–2014

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    Introduction The successful recruitment and retention of participants is integral to the translation of research findings. We examined the recruitment and retention rates of racial/ethnic minority adolescents at a center involved in the National Institutes of Health Obesity Research for Behavioral Intervention Trials (ORBIT) initiative by the 3 recruitment strategies used: clinic, informatics, and community. Methods During the 9-month study, 186 family dyads, each composed of an obese African American adolescent and a caregiver, enrolled in a 6-month weight-loss intervention, a sequential multiple assignment randomized trial. We compared recruitment and retention rates by recruitment strategy and examined whether recruitment strategy was related to dyad baseline characteristics. Results Of the 186 enrolled families, 110 (59.1%) were recruited through clinics, 53 (28.5%) through informatics, and 23 (12.4%) through community. Of those recruited through community, 40.4% enrolled in the study, compared with 32.7% through clinics and 8.2% through informatics. Active refusal rate was 3%. Of the 1,036 families identified for the study, 402 passively refused to participate: 290 (45.1%) identified through informatics, 17 (29.8%) through community, and 95 (28.3%) through clinics. Recruitment strategy was not related to the age of the adolescent, adolescent comorbidities, body mass index of the adolescent or caregiver, income or education of the caregiver, or retention rates at 3 months, 7 months, or 9 months. Study retention rate was 87.8%. Conclusion Using multiple recruitment strategies is beneficial when working with racial/ethnic minority adolescents, and each strategy can yield good retention. Research affiliated with health care systems would benefit from the continued specification, refinement, and dissemination of these strategies

    A competitive ELISA to detect brevetoxins from Karenia brevis (formerly Gymnodinium breve) in seawater, shellfish, and mammalian body fluid

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    We developed a competitive enzyme-linked immunosorbent assay (ELISA) to analyze brevetoxins, using goat anti-brevetoxin antibodies obtained after immunization with keyhole limpet hemocyanin- brevetoxin conjugates, in combination with a three-step signal amplification process. The procedure, which used secondary biotinylated antibodies, streptavidine-horseradish peroxidase conjugate, and chromogenic enzyme substrate, was useful in reducing nonspecific background signals commonly observed with complex matrices. This competitive ELISA detected brevetoxins in seawater, shellfish extract and homogenate, and mammalian body fluid such as urine and serum without pretreatment, dilution, or purification. We investigated the application of this technique for shellfish monitoring by spiking shellfish meat with brevetoxins and by analyzing oysters from two commercial shellfish beds in Florida that were exposed to a bloom of Karenia brevis (formerly Gymnodinium breve). We performed brevetoxin analysis of shellfish extracts and homogenates by ELISA and compared it with the mouse bioassay and receptor binding assay. The detection limit for brevetoxins in spiked oysters was 2.5 µg/100 g shellfish meat. This assay appears to be a useful tool for neurotoxic shellfish poisoning monitoring in shellfish and seawater, and for mammalian exposure diagnostics, and significantly reduces the time required for analyses. Key words: antibody, brevetoxin, detection, ELISA, immunoassay, neurotoxic shellfish poisoning, PbTx, seawater, serum, shellfish, urine. Environ Health Perspect 110:179–185 (2002). [Online 17 January 2002] http://ehpnet1.niehs.nih.gov/docs/2002/110p179-185naar/abstract.htm

    New fish-killing alga in coastal Delaware produces neurotoxins

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    Ten fish mortality events, involving primarily Atlantic menhaden, occurred from early July through September 2000 in several bays and creeks in Delaware, USA. Two events involved large mortalities estimated at 1–2.5 million fish in Bald Eagle Creek, Rehoboth Bay. Samples from Indian Inlet (Bethany Beach), open to the Atlantic, as well as from an enclosed area of massive fish kills at nearby Bald Eagle Creek and Torque Canal were collected and sent to our laboratory for analysis. Microscopic examination of samples from the fish kill site revealed the presence of a single-cell Raphidophyte alga Chattonella cf. verruculosa at a maximum density of 1.04 × 107 cells/L. Naturally occurring brevetoxins were also detected in the bloom samples. Besides the Chattonella species, no other known brevetoxin-producing phytoplankton were present. Chromatographic, immunochemical, and spectroscopic analyses confirmed the presence of brevetoxin PbTx-2, and PbTx-3 and -9 were confirmed by chromatographic and immunochemical analyses. This is the first confirmed report in the United States of brevetoxins associated with an indigenous bloom in temperate Atlantic estuarine waters and of C. cf. verruculosa as a resident toxic organism implicated in fish kills in this area. The bloom of Chattonella continued throughout September and eventually declined in October. By the end of October C. cf. verruculosa was no longer seen, nor was toxin measurable in the surface waters. The results affirm that to avoid deleterious impacts on human and ecosystem health, increased monitoring is needed for brevetoxins and organism(s) producing them, even in areas previously thought to be unaffected. Key words: brevetoxins, Chattonella cf. verruculosa, Delaware, fish kills, harmful agal blooms. Environ Health Perspect 110:465–470 (2002). [Online 1 April 2002] http://ehpnet1.niehs.nih.gov/docs/2002/110p465-470bourdelais/abstract.htm

    Morphology and tectonics of the Mid-Atlantic Ridge, 7°–12°S

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    We present swath bathymetric, gravity, and magnetic data from the Mid-Atlantic Ridge between the Ascension and the Bode Verde fracture zones, where significant ridge–hot spot interaction has been inferred. The ridge axis in this region may be divided into four segments. The central two segments exhibit rifted axial highs, while the northernmost and southernmost segments have deep rift valleys typical of slow-spreading mid-ocean ridges. Bathymetric and magnetic data indicate that both central segments have experienced ridge jumps since ~1 Ma. Mantle Bouguer anomalies (MBAs) derived from shipboard free air gravity and swath bathymetric data show deep subcircular lows centered on the new ridge axes, suggesting that mantle flow has been established beneath the new spreading centers for at least ~1 Myr. Inversion of gravity data indicates that crustal thicknesses vary by ~4 km along axis, with the thickest crust occurring beneath a large axial volcanic edifice. Once the effects of lithospheric aging have been removed, a model in which gravity variations are attributed entirely to crustal thickness variations is more consistent with data from an axis-parallel seismic line than a model that includes additional along-axis variations in mantle temperature. Both geophysical and geochemical data from the region may be explained by the melting of small (<200 km) mantle chemical heterogeneities rather than elevated temperatures. Therefore, there may be no Ascension/Circe plume

    Hot Hypernuclear Matter in the Modified Quark Meson Coupling Model

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    Hot hypernuclear matter is investigated in an explicit SU(3) quark model based on a mean field description of nonoverlapping baryon bags bound by the self-consistent exchange of scalar σ,ζ\sigma, \zeta and vector ω,ϕ\omega, \phi mesons. The σ,ω\sigma, \omega mean fields are assumed to couple to the u,d-quarks while the ζ,ϕ\zeta, \phi mean fields are coupled to the s-quark. The coupling constants of the mean fields with the quarks are assumed to satisfy SU(6) symmetry. The calculations take into account the medium dependence of the bag parameter on the scalar fields σ,ζ\sigma, \zeta. We consider only the octet baryons N,Λ,Σ,ΞN,\Lambda,\Sigma,\Xi in hypernuclear matter. An ideal gas of the strange mesons KK and KK^{*} is introduced to keep zero net strangeness density. Our results for symmetric hypernuclear matter show that a phase transition takes place at a critical temperature around 180 MeV in which the scalar mean fields σ,ζ\sigma, \zeta take nonzero values at zero baryon density. Furthermore, the bag contants of the baryons decrease significantly at and above this critical temperature indicating the onset of quark deconfinement. The present results imply that the onset of quark deconfinement in SU(3) hypernuclear matter is much stronger than in SU(2) nuclear matter.Comment: LaTeX/TeX 11 pages (dfg3r.tex), 9 figures in eps forma

    Finite Temperature Quark Matter and Supernova Explosion

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    We study the equation of state of quark matter at finite temperature, using a confinement model in which chiral symmetry remains broken in the deconfined phase. Implications for type II supernova explosion and for the structure and evolution of the proto-neutron star are discussed.Comment: RevTeX file + 5 postscript figure
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