Mg I emission lines at 12 and 18 micrometer in K giants

The solar Mg I emission lines at 12 micrometer have already been observed and analyzed well. Previous modeling attempts for other stars have, however, been made only for Procyon and two cool evolved stars, with unsatisfactory results for the latter. We present high-resolution observational spectra for the K giants Pollux, Arcturus, and Aldebaran, which show strong Mg I emission lines at 12 micrometer as compared to the Sun. We also present the first observed stellar emission lines from Mg I at 18 micrometer and from Al I, Si I, and presumably Ca I at 12 micrometer. To produce synthetic line spectra, we employ standard non-LTE modeling for trace elements in cool stellar photospheres. We compute model atmospheres with the MARCS code, apply a comprehensive magnesium model atom, and use the radiative transfer code MULTI to solve for the magnesium occupation numbers in statistical equilibrium. We successfully reproduce the observed Mg I emission lines simultaneously in the giants and in the Sun, but show how the computed line profiles depend critically on atomic input data and how the inclusion of energy levels with n > 9 and collisions with neutral hydrogen are necessary to obtain reasonable fits.Comment: 9 pages, 6 figures, accepted for publication in Astronomy & Astrophysic

Fluorine in the solar neighborhood - is it all produced in AGB-stars?

The origin of 'cosmic' fluorine is uncertain, but there are three proposed production sites/mechanisms: AGB stars, $\nu$ nucleosynthesis in Type II supernovae, and/or the winds of Wolf-Rayet stars. The relative importance of these production sites has not been established even for the solar neighborhood, leading to uncertainties in stellar evolution models of these stars as well as uncertainties in the chemical evolution models of stellar populations. We determine the fluorine and oxygen abundances in seven bright, nearby giants with well-determined stellar parameters. We use the 2.3 $\mu$m vibrational-rotational HF line and explore a pure rotational HF line at 12.2 $\mu$m. The latter has never been used before for an abundance analysis. To be able to do this we have calculated a line list for pure rotational HF lines. We find that the abundances derived from the two diagnostics agree. Our derived abundances are well reproduced by chemical evolution models only including fluorine production in AGB-stars and therefore we draw the conclusion that this might be the main production site of fluorine in the solar neighborhood. Furthermore, we highlight the advantages of using the 12 $\mu$m HF lines to determine the possible contribution of the $\nu$-process to the fluorine budget at low metallicities where the difference between models including and excluding this process is dramatic

TEXES Observations of M Supergiants: Dynamics and Thermodynamics of Wind Acceleration

We have detected [Fe II] 17.94 um and 24.52 um emission from a sample of M supergiants using TEXES on the IRTF. These low opacity emission lines are resolved at R = 50, 000 and provide new diagnostics of the dynamics and thermodynamics of the stellar wind acceleration zone. The [Fe II] lines, from the first excited term, are sensitive to the warm plasma where energy is deposited into the extended atmosphere to form the chromosphere and wind outflow. These diagnostics complement previous KAO and ISO observations which were sensitive to the cooler and more extended circumstellar envelopes. The turbulent velocities, Vturb is about 12 to 13 km/s, observed in the [Fe II] forbidden lines are found to be a common property of our sample, and are less than that derived from the hotter chromospheric C II] 2325 Angstrom lines observed in alpha Ori, where Vturb is about 17 to 19 km/s. For the first time, we have dynamically resolved the motions of the dominant cool atmospheric component discovered in alpha Ori from multi-wavelength radio interferometry by Lim et al. (1998). Surprisingly, the emission centroids are quite Gaussian and at rest with respect to the M supergiants. These constraints combined with model calculations of the infrared emission line fluxes for alpha Ori imply that the warm material has a low outflow velocity and is located close to the star. We have also detected narrow [Fe I] 24.04 um emission that confirms that Fe II is the dominant ionization state in alpha Ori's extended atmosphere.Comment: 79 pages including 10 figures and 2 appendices. Accepted by Ap

The Prevalence of Social Science in Gay Rights Cases: The Synergistic Influences of Historical Context, Justificatory Citation, and Dissemination Efforts

Disjunctive legal change is often accompanied by a period of frantic activity as the competing forces of stasis and evolution vie for domination. Nowhere is the battle for legal change likely to be more sharply joined than when the findings of modern science, in their varied and multifarious forms, are pitted directly against prevailing moral or societal precepts. One of the latest incarnations of this trend is the battle over the legal recognition of gay rights. In recent history, the courts have been inundated by gay litigants seeking the rights and protections already afforded other discrete groups within society. In the resulting legal skirmishes, gay individuals are resorting with increasing regularity to the sciences in an effort to overcome the moral opprobrium surrounding homosexuality. The judicial opinions which have resulted from the onslaught of gay litigants have not remained untouched by the scientific information adduced. Rather, as this Article will demonstrate, a disproportionally large number of gay rights opinions contain citations and references to social science information. These judicial opinions have become artifacts of the battle between modern science and existing moral conceptions of homosexuality and provide a discrete microcosm within which to examine science\u27s contribution to legal change. The lessons derived from gay rights cases may help to elucidate other contexts in which science and morality meet head-on

Spatiotemporal changes to low flow and catchment storage following a step change rainfall decline in Southwest Western Australia

Understanding how summer low flows in a Mediterranean climate are influenced by climate and land use is critical for managing both water resources and in-stream ecohydrological health. The Eucalyptus forest ecosystems of southwestern Australia are experiencing a drying and warming climate, with a regional step decline in rainfall in the mid-1970s. Reductions in catchment water storage may be exacerbated by the deep rooting habit of key overstorey species (>30 m has been reported), which can buffer against drought during dry years. Root exploitation of deep soil moisture reserves and/or groundwater can accelerate the long term decline in summer low flows, with a trend towards more ephemeral flow regimes. In contrast, conversion of forests to agricultural land in some catchments can lead to counter-trends of increased low flows due to a rise in groundwater pressure. These are invariably associated with an increase in stream salinity as regolith stores of salt are mobilized. There has also been extennsive reforestation of farmland in some catchments. In this study we perform a detailed analysis of changes to annual summer seven day low flow trends in perennial catchments and flow duration curves in ephemeral catchments across 39 catchments in south-western Australia that have long term records of runoff, rainfall and land cover. Results showed that 15% of catchments exhibited increased low flows and 85% decreased flows or decreased flow days since the 1970s. Significant downward step changes in low flows were observed in 17 catchments (44%). The earliest downward step changes occurred in three catchments between 1981-82 (a lag of one decade after the rainfall decline), with the most recent step changes for five catchments occurring in 2001-2004 (three decades after rainfall decline). Eleven catchments were already ephemeral in the 1970s, but exhibited continued declines in the number of annual flow days over subsequent decades. Step changes occur when groundwater becomes disconnected or reconnected to the stream invert, with disconnection associated with rainfall decline and vegetative water use. The statistical methods we used in this study can be applied to any catchment in order to aid land and water managers assess the impact of climate change and land cover manipulation on low flow response

Efficacy of a Workbook to Promote Forgiveness: A Randomized Controlled Trial with University Students

Objective The present study investigated the efficacy of a 6-hour self-directed workbook adapted from the REACH Forgiveness intervention. Method Undergraduates (N = 41) were randomly assigned to either an immediate treatment or waitlist control condition. Participants were assessed across 3 time periods using a variety of forgiveness outcome measures. Results The 6-hour workbook intervention increased forgiveness, as indicated by positive changes in participants’ forgiveness ratings that differed by condition. In addition, benchmarking analysis showed that the self-directed workbook intervention is at least as efficacious as the delivery of the REACH Forgiveness model via group therapy. Conclusion A self-directed workbook intervention adapted from the REACH Forgiveness intervention provides an adjunct to traditional psychotherapy that could assist the mental health community to manage the burden of unforgiveness among victims of interpersonal harm

Frankbaronia velata nov. sp., a putative peronosporomycete oogonium containing multiple oospores from the Lower Devonian Rhynie chert

Spherical to pyriform microfossils containing multiple smooth-walled spherules from the Lower Devonian Rhynie chert are described as oogonia of a new fossil peronosporomycete based on congruencies in basic morphology to the polyoosporous oogonia of certain extant Saprolegniales. Because the new fossils also resemble Frankbaronia polyspora, a putative peronosporomycete described previously from the Rhynie chert, they are assigned to the fossil genus Frankbaronia and formally proposed as a new species, F. velata. Surrounding the oogonium is a conspicuous sheath of consolidated mucilage, produced and secreted by the oogonium during development. The discovery of F. velata adds to our understanding of the microbial diversity in early terrestrial ecosystems, and contributes to the documentation of the evolutionary history of the Peronosporomycetes.Kugelige bis tropfenförmige, glattwandige kugelige Strukturen in großer Zahl enthaltende Mikrofossilien aus dem unterdevonischen Rhynie Chert werden als Oogonien eines neuen fossilen Peronosporomyzeten beschrieben, da sie den polyoosporen Oogonien einiger heutiger Saprolegniales morphologisch sehr ähnlich sind. Da die Fossilien auch mit Frankbaronia polyspora, einem bereits früher aus dem Rhynie Chert beschriebenen vermeintlichen Peronosporomyzeten, gut vergleichbar sind, werden sie ebenfalls in die Gattung Frankbaronia gestellt und als neue Art, F. velata, eingeführt. Die Oogonien sind von einer auffälligen Hülle aus konsolidiertem Schleim umgeben, welcher vom sich entwickelnden Oogonium produziert und sekretiert wurde. Frankbaronia velata trägt zu einem besseren Verständnis der mikrobiellen Diversität in frühen terrestrischen Ökosystemen sowie zur Dokumentation der Evolutionsgeschichte der Peronosporomycetes bei