Colloidal Stability and Toxicity of Gold Nanoparticles and Gold Chloride on <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis>

Here we have examined interactions of gold nanoparticles differing in primary particle size and coating with the green algae Chlamydomonas reinhardtii as function of the colloidal stability of the particles in the experimental media used for toxicity studies. Interactions of dissolved Au³⁺ ions with algae were also examined. Included endpoints were photosynthetic yield and algal growth. Morphological and structural effects were examined microscopically and by flow cytometry. The results indicate no significant toxicity of gold nanoparticles to C. reinhardtii. Analysis of published data suggests toxicity of gold nanoparticles on algal growth to relate rather to particular coatings than to the gold core.     

3XMM J185246.6+003317 as transient neutron star

We performed an X‐ray timing and spectral analysis of the variable source 3XMM J185246.6+003317 to investigate its physical nature. The data from all observations of 3XMMJ185246.6+003317 conducted by XMM‐Newton EPIC MOS1 and MOS2 with the same instrumental setup in 2004–2009 were reprocessed to form a homogenous data set of solar barycenter corrected photon arrival times and high S/N spectra of 3XMM J185246.6+003317. A Bayesian method for the search, detection, and estimation of the parameters of a periodic signal of unknown shape was employed, as developed by Gregory & Loredo (1992, 1993). The results show that 3XMM J185246.6+003317 is a transient neutron star with the genuine spin‐period of 23.11722 (23.11711–23.11727) s and its derivative of 5.3(0.3–5.5)×10^–11 s s^–1, implying a characteristic age of 7 (6–104) kyr, if the period derivative can be ascribed to the genuine spin‐down rate of the neutron star. The rotational‐phase averaged X‐ray spectra at the different brightness periods can be fitted with a highly absorbed blackbody model with different temperatures. The phase‐folded light curves in different energy bands with high S/N ratio show a double‐peaked profile; the variations depend on time and energy, indicating that radiation emerges from at least two emitting areas. The spectra at the phases corresponding to the maxima in the phase‐folded light curve show different spectral parameters of absorbed blackbody radiation, i.e. the hotter one has a smaller size. The source is detected only from September 2008 to April 2009 with persistently decreasing brightness, but not before, even though it was observed by XMM. Hence, it is a transient neutron star or a binary system hosting it. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Confronting the challenge of integrated assessment of climate adaptation: a conceptual framework

Key limitations of integrated assessment models (IAMs) are their highly stylized and aggregated representation of climate damages and associated economic responses, as well as the omission of specific investments related to climate change adaptation. This paper proposes a framework for modeling climate impacts and adaptation that clarifies the relevant research issues and provides a template for making improvements. We identify five desirable characteristics of an ideal integrated assessment modeling platform, which we elaborate into a conceptual model that distinguishes three different classes of adaptation-related activities. Based on these elements we specify an impacts- and adaptation-centric IAM, whose optimality conditions are used to highlight the types of functional relationships necessary for realistic representations of adaptation-related decisions, the specific mechanisms by which these responses can be incorporated into IAMs, and the ways in which the inclusion of adaptation is likely to affect the simulations’ results.     

Climate change and mental health: an exploratory case study from Rigolet, Nunatsiavut, Canada

As the impacts from anthropogenic climate change are increasing globally, people are experiencing dramatic shifts in weather, temperature, wildlife and vegetation patterns, and water and food quality and availability. These changes impact human health and well-being, and resultantly, climate change has been identified as the biggest global health threat of the 21st Century. Recently, research is beginning to indicate that changes in climate, and the subsequent disruption to the social, economic, and environmental determinants of health, may cause increased incidences and prevalence of mental health issues, emotional responses, and large-scale sociopsychological changes. Through a multi-year, community-led, exploratory case study conducted in Rigolet, Nunatsiavut, Labrador, Canada, this research qualitatively explores the impacts of climate change on mental health and well-being in an Inuit context. Drawing from 67 in-depth interviews conducted between January 2010 and October 2010 with community members and local and regional health professionals, participants reported that changes in weather, snow and ice stability and extent, and wildlife and vegetation patterns attributed to climate change were negatively impacting mental health and well-being due to disruptions in land-based activities and a loss of place-based solace and cultural identity. Participants reported that changes in climate and environment increased family stress, enhanced the possibility of increased drug and alcohol usage, amplified previous traumas and mental health stressors, and were implicated in increased potential for suicide ideation. While a preliminary case study, these exploratory findings indicate that climate change is becoming an additional mental health stressor for resource-dependent communities and provide a baseline for further research.     

Do people “personally experience” global warming,and if so how,and does it matter?

For most people, the direct and personally observable signals of climate change should be difficult to detect amid the variability of everyday weather. Yet, previous research has shown that some people believe they have personally experienced global warming. Through four related studies, our paper sheds light on what signals of global warming some people believe they are detecting, why, and whether or not it matters. These studies were conducted using population survey and climatic data from a single county in Michigan. Study 1 found that 27% of the county's adult residents felt that they had personally experienced global warming. Study 2 – based on content analysis of people's open-ended responses – found that the most frequently described personal experiences of global warming were changes in seasons (36%), weather (25%), lake levels (24%), animals and plants (20%), and snowfall (19%). Study 3 – based on NOAA climatic data – found that most, but not all, of these detected signals are borne out in the climatic record. Study 4 – using the survey data – found that personal experience of global warming matters in that it predicts perceptions of local risk of global warming, controlling for demographics, political affiliation, and cultural beliefs about national policy outcomes. We conclude that perceived personal experience of global warming appears to heighten people's perception of the risks, likely through some combination of direct experience, vicarious experience (e.g., news media stories), and social construction.     

A high-resolution infrared spectral survey of Comet C/1999 H1 Lee

We obtained high-resolution (λ/Δλ∼25,000) spectra of Comet C/1999 H1 (Lee) on UT 1999 August 19.6 and 21.6 using the cross-dispersed Near InfraRed SPECtrometer (NIRSPEC) at the Keck Observatory atop Mauna Kea, HI. Here we present spectra of Comet Lee between 2.874 and 3.701 μm (3479-2702 cm⁻¹) representing the most complete high-resolution infrared survey of a comet to date in this wavelength region. Using published line lists and laboratory spectra we have identified 444 of the 545 distinct emission features present in these spectra. We have tabulated the rest frequencies, assignments, relative intensities, and signal-to-noise ratios of all detected emissions. In addition to gaining insights into the chemistry of Comet Lee, this survey provides a valuable tool for planning future high-resolution infrared observations of comets and other astronomical targets, and for retrospective comparison to existing high-resolution infrared datasets.     

Response of surface water chemistry to reduced levels of acid precipitation: comparison of trends in two regions of New York,USA

In light of recent reductions in sulphur (S) and nitrogen (N) emissions mandated by Title IV of the Clean Air Act Amendments of 1990, temporal trends and trend coherence in precipitation (1984–2001 and 1992–2001) and surface water chemistry (1992–2001) were determined in two of the most acid‐sensitive regions of North America, i.e. the Catskill and Adirondack Mountains of New York. Precipitation chemistry data from six sites located near these regions showed decreasing sulphate (SO₄^2?), nitrate (NO₃^?), and base cation (C_B) concentrations and increasing pH during 1984–2001, but few significant trends during 1992–2001. Data from five Catskill streams and 12 Adirondack lakes showed decreasing trends in SO₄^2? concentrations at all sites, and decreasing trends in NO₃^?, C_B, and H⁺ concentrations and increasing trends in dissolved organic carbon at most sites. In contrast, acid‐neutralizing capacity (ANC) increased significantly at only about half the Adirondack lakes and in one of the Catskill streams. Flow correction prior to trend analysis did not change any trend directions and had little effect on SO₄^2? trends, but it caused several significant non‐flow‐corrected trends in NO₃^? and ANC to become non‐significant, suggesting that trend results for flow‐sensitive constituents are affected by flow‐related climate variation. SO₄^2? concentrations showed high temporal coherence in precipitation, surface waters, and in precipitation–surface water comparisons, reflecting a strong link between S emissions, precipitation SO₄^2? concentrations, and the processes that affect S cycling within these regions. NO₃^? and H⁺ concentrations and ANC generally showed weak coherence, especially in surface waters and in precipitation–surface water comparisons, indicating that variation in local‐scale processes driven by factors such as climate are affecting trends in acid–base chemistry in these two regions. Copyright © 2005 John Wiley & Sons, Ltd.     

Instruments, Detectors and the Future of Astronomy with Large Ground Based Telescopes

Results of a survey of instrumentation and detector systems, either currently deployed or planned for use at telescopes larger than 3.5 m, in ground based observatories world-wide, are presented. This survey revealed a number of instrumentation design trends at optical, near, and mid-infrared wavelengths. Some of the most prominent trends include the development of vastly larger optical detector systems (> 10⁹ pixels) than anything built to date, and the frequent use of mosaics of near-infrared detectors – something that was quite rare only a decade ago in astronomy. Some future science applications for detectors are then explored, in an attempt to build a bridge between current detectors and what will be needed to support the research ambitions of astronomers in the future.     

400 Jahre Mathematik und Astronomie an der Universität Würzburg: Alma Julia Herbipolensis 1582–1982

Ohne Zusammenfassung

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400 years mathematics and astronomy at the Wurzburg University: Alma Julia herbipolensis 1582–1982

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s. O. Volk, Mathematik, Astronomie und Physik in der Vergangenheit der Universität Würzburg, Festschrift 1982.

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Paper presented at the 1981 Oberwolfach Conference on Mathematical Methods in Celestial Mechanics.