440 research outputs found

    Strategische Planungen in naturräumlich definierten Handlungsräumen - Anpassung an den Klimawandel in der Region Starkenburg

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    Der Beitrag beschreibt die Erarbeitung eines Handlungskonzepts „Anpassung an den Klimawandel“ im Einzugsgebiet des südhessischen Flusses Gersprenz. Dabei handelt es sich um einen strategischen Planungsprozess, der im Rahmen des Forschungsprojekts KLARA-Net gemeinsam mit den regionalen Akteuren durchgeführt wird. Die Vorgehensweise in einem solchen akteursgetragenen Planungsprozess und die einzelnen Bausteine des Konzepts werden vorgestellt. Überdies werden diese praktischen Erfahrungen eingebettet in den theoretischen Kontext, wobei insbesondere auf die noch junge Diskussion zur strategischen Planung bei der Anpassung an den Klimawandel Bezug genommen wird.This paper describes work to frame an action strategy for “Adaptation to climate change” for the catchment area of the river Gersprenz in the south of the state of Hesse. This is an example of a strategic planning process conducted in partnership with regional actors within the framework of the KLARA-Net research project. The authors describe the approach adopted in a planning process of this type, which is carried by the actors involved in it; they then set out the individual component parts of the strategy. Moreover, practical experience is embedded within the theoretical context; here reference is made in particular to the discussion – still in its infancy – on strategic planning in the context of adaptation to climate change

    Beurteilung der Gesamtumweltexposition von Silberionen aus Biozid-Produkten

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    BEURTEILUNG DER GESAMTUMWELTEXPOSITION VON SILBERIONEN AUS BIOZID-PRODUKTEN Beurteilung der Gesamtumweltexposition von Silberionen aus Biozid-Produkten / Hund-Rinke, Kerstin (Rights reserved) ( -

    Imaging the circumstellar envelopes of AGB stars

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    We report the results of an exploratory program to image the extended circumstellar envelopes of asymptotic giant branch (AGB) stars in dust-scattered galactic light. The goal is to characterize the morphology of the envelopes as a probe of the mass-loss process. The observations consist of short exposures with the VLT and longer exposures with 1-2m telescopes, augmented with archival images from the Hubble Space Telescope. We observed 12 AGB stars and detected the circumstellar envelopes in 7. The detected envelopes have mass loss rates more than about 5 10E-6 solar mass per year, and they can be seen out to distances of about 1 kpc. The observations provide information on the mass loss history on time scales up to about 10,000 years. For the five AGB envelopes in which the circumstellar geometry is well determined by scattered light observations, all except one (OH348.2-19.7) show deviations from spherical symmetry. Two (IRC+10216 and IRC+10011) show roughly spherical envelopes at large radii but asymmetry or bipolarity close to the star; one (AFGL 2514) shows an extended, elliptical envelope, and one (AFGL 3068) shows a spiral pattern. The non-spherical structures are all consistent with the effects of binary interactions. Our observations are in accord with a scenario in which binary companions play a role in shaping planetary nebulae, and show that the circumstellar gas is already partly shaped on the AGB, before evolution to the proto-planetary nebula phase.Comment: Accepted by AA 21 Feb 2006; 18 pages, 14 figs; for high resolution images, contact mauron at graal.univ-montp2.f

    The massive expanding molecular torus in the planetary nebula NGC 6302

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    We measure the mass and kinematics of the massive molecular torus in the planetary nebula NGC 6302. The nebula is the proto-typical butterfly nebula. The origin of the wing-like morphology is disputed: determining the mass-loss history of the confining torus is an important step in understanding the formation of this structure. We performed submillimeter observations with JCMT and the SMA interferometer. The continuum emission as well as the J=2-1 and 3-2 transitions of 12CO and 13CO are analysed at arcsecond resolution. The CO emission indicates a mass of the torus of ~ 2Msun +/- 1Msun. The 12CO and 13CO emission matches the dark lane seen in absorption in the Halpha image of the object. The CO torus is expanding with a velocity of ~ 8 km/s, centred at Vlsr=-31.5 km/s. The size and expansion velocity of the torus indicates that the torus was ejected from ~ 7500 yr to 2900 yr ago, with a mass-loss rate of 5x10^{-4}Msun/yr. We also see a ballistic component in the CO images with a velocity gradient of 140 km/s/pc. The derived mass-loss history of the torus favours binary interaction as the cause of the ejection of the torus. We predict the existence of a companion with an orbital period P < 1 month.Comment: 13 pages, 10 figures, accepted for publication in A&

    Ectopic pregnancy: when is expectant management safe?

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    This study was conducted to evaluate expectant management in asymptomatic patients with an initial serum beta-hCG titer of <2,500 IU/l and to determine the independent ability of initial serum beta-hCG titers and trend of serum beta-hCG to predict successful expectant management. A cohort of patients (N = 418) with suspected ectopic pregnancy (EP) between January 1991 and July 2008 is described. Three groups were defined: group I (n = 182), immediate surgical intervention (<24 h); group IIa (n = 130), unsuccessful expectant management (surgical intervention during follow-up), and group IIb (n = 99), successful expectant management (spontaneous regression of trophoblast). Hospital protocol was not complied in 35 cases (Table 1). Beta-hCG levels >3,000 IU/l occur in our expectant management group; however, none of these cases were successful. Unnecessary surgery was prevented in 14% (n = 7) of asymptomatic patients with initial beta-hCG of >2,000 IU/l. The success rate of expectant management was 49%, without a rise in complication rate or number of acute cases. In conclusion, the initial serum beta-hCG cutoff level of 2,000 IU/l is not a rigid upper limit for accepting expectant management in suspected EP and best practice is case specific. In asymptomatic patients, the serum beta-hCG cutoff level of at least 2,500 IU/l can be used for expectant management. This cutoff could be higher, but interpretation is limited due to censure in follow-up inherent to the predefined clinical protocol. There is no gain in including patients for expectant management with initial serum beta-hCG level >3,000 IU/l

    Low-Mass Binary Induced Outflows from Asymptotic Giant Branch Stars

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    A significant fraction of planetary nebulae (PNe) and proto-planetary nebulae (PPNe) exhibit aspherical, axisymmetric structures, many of which are highly collimated. The origin of these structures is not entirely understood, however recent evidence suggests that many observed PNe harbor binary systems, which may play a role in their shaping. In an effort to understand how binaries may produce such asymmetries, we study the effect of low-mass (< 0.3 M_sun) companions (planets, brown dwarfs and low-mass main sequence stars) embedded into the envelope of a 3.0 M_sun star during three epochs of its evolution (Red Giant Branch, Asymptotic Giant Branch (AGB), interpulse AGB). We find that common envelope evolution can lead to three qualitatively different consequences: (i) direct ejection of envelope material resulting in a predominately equatorial outflow, (ii) spin-up of the envelope resulting in the possibility of powering an explosive dynamo driven jet and (iii) tidal shredding of the companion into a disc which facilitates a disc driven jet. We study how these features depend on the secondary's mass and discuss observational consequences.Comment: 24 pages, 6 figures, submitted to MNRA

    Coordinated Analyses of Presolar Grains in the Allan Hills 77307 and Queen Elizabeth Range 99177 Meteorites

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    We report the identification of presolar silicates (~177 ppm), presolar oxides (~11 ppm), and one presolar SiO2 grain in the Allan Hills (ALHA) 77307 chondrite. Three grains having Si isotopic compositions similar to SiC X and Z grains were also identified, though the mineral phases are unconfirmed. Similar abundances of presolar silicates (~152 ppm) and oxides (~8 ppm) were also uncovered in the primitive CR chondrite Queen Elizabeth Range (QUE) 99177, along with 13 presolar SiC grains and one presolar silicon nitride. The O isotopic compositions of the presolar silicates and oxides indicate that most of the grains condensed in low-mass red giant and asymptotic giant branch stars. Interestingly, unlike presolar oxides, few presolar silicate grains have isotopic compositions pointing to low-metallicity, low-mass stars (Group 3). The 18O-rich (Group 4) silicates, along with the few Group 3 silicates that were identified, likely have origins in supernova outflows. This is supported by their O and Si isotopic compositions. Elemental compositions for 74 presolar silicate grains were determined by scanning Auger spectroscopy. Most of the grains have non-stoichiometric elemental compositions inconsistent with pyroxene or olivine, the phases commonly used to fit astronomical spectra, and have comparable Mg and Fe contents. Non-equilibrium condensation and/or secondary alteration could produce the high Fe contents. Transmission electron microscopic analysis of three silicate grains also reveals non-stoichiometric compositions, attributable to non-equilibrium or multistep condensation, and very fine scale elemental heterogeneity, possibly due to subsequent annealing. The mineralogies of presolar silicates identified in meteorites thus far seem to differ from those in interplanetary dust particles.Comment: 23 pages, 16 figure

    Dietary supplement use among health care professionals enrolled in an online curriculum on herbs and dietary supplements

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    BACKGROUND: Although many health care professionals (HCPs) in the United States have been educated about and recommend dietary supplements, little is known about their personal use of dietary supplements and factors associated with their use. METHODS: We surveyed HCPs at the point of their enrollment in an on-line course about dietary supplements between September, 2004 and May, 2005. We used multivariable logistic regression to analyze demographic and practice factors associated with use of dietary supplements. RESULTS: Of the 1249 health care professionals surveyed, 81 % reported having used a vitamin, mineral, or other non-herbal dietary supplements in the last week. Use varied by profession with highest rates among nurses (88%), physician assistants or nurse practitioners (84 %) and the lowest rates among pharmacists (66%) and trainees (72%). The most frequently used supplements were multivitamins (60%), calcium (40%), vitamin B (31%), vitamin C (30%), and fish oil (24%). Factors associated with higher supplement use were older age, female, high knowledge of dietary supplements, and discussing dietary supplements with patients. In our adjusted model, nurses were more likely than other professionals to use a multivitamin and students were more likely to use calcium. CONCLUSION: Among HCPs enrolled in an on-line course about dietary supplements, women, older clinicians, those with higher knowledge and those who talk with patients about dietary supplements had higher use of dietary supplements. Additional research is necessary to understand the impact of professionals' personal use of dietary supplements on communication with patients about them
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