9 research outputs found

    Determining fluid migration and isolation times in multiphase crustal domains using noble gases

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    Geochemical characteristics in subsurface fluid systems provide a wealth of information about fluid sources, migration, and storage conditions. Determining the extent of fluid interaction (aquifer-hydrocarbon connectivity) is important for oil and gas production and waste storage applications, but is not tractable using traditional seismic methods. Furthermore, the residence time of fluids is critical in such systems and can vary from tens of thousands to billions of years. Our understanding of the transport length scales in multiphase systems, while equally important, is more limited. Noble gas data from the Rotliegend natural gas field, northern Germany, are used here to determine the length scale and isolation age of the combined water-gas system. We show that geologically bound volume estimates (i.e., gas to water volume ratios) match closed-system noble gas model predictions, suggesting that the Rotliegend system has remained isolated as a closed system since hydrocarbon formation. Radiogenic helium data show that fluid isolation occurred 63–129 m.y. after rock and/or groundwater deposition (ca. 300 Ma), which is consistent with known hydrocarbon generation from 250 to 140 Ma, thus corroborating long-term geologic isolation. It is critical that we have the ability to distinguish between fluid systems that, despite phase separation, have remained closed to fluid loss from those that have lost oil or gas phases. These findings are the first to demonstrate that such systems remain isolated and fully gas retentive on time scales >100 m.y. over >10 km length scales, and have broad implications for saline aquifer CO2 disposal site viability and hydrocarbon resource prediction, which both require an understanding of the length and time scales of crustal fluid transport pathways

    The spectral energy distribution of fermi bright blazars

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    We have conducted a detailed investigation of the broadband spectral properties of the Îł-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi Îł-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/Îł-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these Îł-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log Îœ-log Îœ FÎœ representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, αro, and optical to X-ray, αox, spectral slopes) and from the Îł-ray spectral index. Our data show that the synchrotron peak frequency (ÎœSpeak) is positioned between 1012.5 and 1014.5 Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 10 13 and 1017 Hz in featureless BL Lacertae objects. We find that the Îł-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright FSRQs and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter Îł-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple SSC models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study. Since the LAT detector is more sensitive to flat spectrum Îł-ray sources, the correlation between ÎœSpeak and Îł-ray spectral index strongly favors the detection of high energy peaked blazars, thus explaining the Fermi overabundance of this type of sources compared to radio and EGRET samples. This selection effect is similar to that experienced in the soft X-ray band where HBL BL Lacs are the dominant type of blazars. © 2010 The American Astronomical Society

    Anti-Toxoplasma Activity of Estragole and Thymol in Murine Models of Congenital and Noncongenital Toxoplasmosis

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    Toxoplasmosis is caused by Toxoplasma gondii, an obligatory intracellular protozoan. Normally benign, T. gondii infections can cause devastating disease in immunosuppressed patients and through congenital infection of newborn babies. Few prophylactic and therapeutic drugs are available to treat these infections. The goal of the present study was to assess the anti-Toxoplasma effects in a congenital and noncongenital model of toxoplasmosis (using ME49 strain), besides assessing immunological changes, in vitro cytotoxicity, and in vivo acute toxicity of commercial estragole and thymol. The congenital experimental model was used with intermediate stages of maternal infection. The serum levels of immunoglobulin (Ig)M, IgG, interleukin (IL)-10, IL-12, and interferon-gamma (IFN-γ) were quantified from infected and treated C57Bl/6 mice. Estragole and thymol respectively exhibited low to moderate in vivo toxicity and cytotoxicity. Animals treated with estragole showed high IFN-γ and strong type 1 helper T cell response. Both compounds were active against T. gondii ME49 strain. Furthermore, orally administered estragole in infected pregnant mice improved the weight of offspring compared with untreated controls. Subcutaneous administration of both compounds also increased the weight of mouse offspring born to infected mothers, compared with untreated controls. Estragole and thymol display important anti-Toxoplasma activity. Further studies are needed to elucidate the mechanism of action of these compounds. © American Society of Parasitologists 2016

    Patent Litigation Strategy and Its Effects on the Firm

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    Patent litigation has attracted scholarly attention to reconcile multiple views for new research. Accordingly, this paper addresses patent litigation strategy and its effect on the firm. Based on 106 papers and articles, six books, the author\u27s logic and practice impressions, it first defines patent litigation strategy and differentiates similar concepts. Second, based on the process, the author fine‐tunes patent litigation strategy into three tactics: threat, filing and verdict. Then, she categorizes and examines the impact of patent litigation on market value, monetary gain/loss and strategic collaboration. The findings show that the effect on the market value is more complex and ambiguous than anticipated, and sometimes contradictory. The analysis shows the consistency of monetary effect in practice, that firms tend to have higher monetary gains from private settlement than from legal awards. It also demonstrates that existing studies lag behind reality in investigating the detailed role of patent litigation on strategic collaboration from partnership (e.g. licensing and strategic alliance) to takeover (i.e. merger and acquisition). Finally, the author reflects on the findings, and maps out critical paths toward new research. This process also reveals that stakeholders, industrial settings and country environments moderate the studied relationship. This paper contributes to knowledge and practice: appreciates the interdisciplinary endeavors to draw the findings; categorizes patent litigation and its effect; and critiques prior studies on the relationship to integrate knowledge for future research
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