Anchors for the cosmic distance scale: the Cepheid QZ Normae in the open cluster NGC 6067

Cepheids are key to establishing the cosmic distance scale. Therefore it’s important to assess the viability of QZ Nor, V340 Nor, and GU Nor as calibrators for Leavitt’s law via their purported membership in the open cluster NGC 6067. The following suite of evidence confirms that QZ Nor and V340 Nor are members of NGC 6067, whereas GU Nor likely lies in the foreground: (i) existing radial velocities for QZ Nor and V340 Nor agree with that established for the cluster ( $-39.4\pm0.2(\sigma_{\bar {x}}) \pm1.2 (\sigma)~\mbox{km/s}$ ) to within 1 km/s, whereas GU Nor exhibits a markedly smaller value; (ii) a steep velocity-distance gradient characterizes the sight-line toward NGC 6067, thus implying that objects sharing common velocities are nearly equidistant; (iii) a radial profile constructed for NGC 6067 indicates that QZ Nor is within the cluster bounds, despite being 20′ from the cluster center; (iv) new BVJH photometry for NGC 6067 confirms the cluster lies d=1.75±0.10 kpc distant, a result that matches Wesenheit distances computed for QZ Nor/V340 Nor using the Benedict et al. (Astron. J. 133:1810, 2007, HST parallaxes) calibration. QZ Nor is a cluster Cepheid that should be employed as a calibrator for the cosmic distance scale.     

Satellite-based peatland mapping: Potential of the MODIS sensor

Peatlands play a major role in the global carbon cycle but are largely overlooked in current large-scale vegetation mapping efforts. In this study, we investigated the potential of the Moderate Resolution Imaging Spectroradiometer (MODIS) to capture the extent and distribution of peatlands in the St. Petersburg region of Russia by analyzing the relationships between peatland cover fractions derived from reference maps and  1-km resolution MODIS Nadir BRDF-Adjusted Reflectance (NBAR) data from year 2002.First, we characterized and mapped 50 peatlands from forest inventory and peat deposit inventory data. The peatlands represent three major nutritional types (oligotrophic, mesotrophic, eutrophic) and different sizes (0.6–7800 ha). In addition, parts of 6 peatlands were mined for peat and these were mapped separately. The reference maps provided information on peatland cover for 1105 MODIS pixels. We performed regression analysis on 50% of the pixels and reserved the remainder for model validation. Canonical correlation analysis on the MODIS reflectance bands and the peatland cover fractions produced a multi-spectral peatland cover index (PCI), which served as the predictor in a reduced major axis (RMA) regression model. The results suggest a high potential for mapping peatlands with MODIS. The RMA regression models explained much of the variance in the PCI (r² = 0.74 for mined and r² = 0.81 for unmined peatlands). Model validation showed high correlation between observed versus predicted peatland cover (mined: r = 0.87; unmined: r = 0.92). We used the models to derive peatland cover estimates for the St. Petersburg region and compared the results to current MODIS land cover maps.     

Selenium and heavy metals content in some Mediterranean soils

The study of metal contents in industrial, agricultural or/and polluted soils compared with natural or unpolluted soils is currently necessary to obtain reference values and to assess soil contamination. Nonetheless, very few works published appear in international journals on elements like Se, Li and Sr in Spanish soils. This study determines the total levels of Se, Li, Sr, As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, Fe, Mn and Ba in 14 natural (unpolluted) soils (Gypsisols, Leptosols, Arenosols and Acrisols), 14 agricultural soils (Anthrosols, Fluvisols and Luvisols), and 4 industrial–urban affected-surface soil horizons (Anthrosols and Fluvisols) of Eastern Spain. The geochemical baseline concentrations (GBC) and reference values (RV) have been established, and the relationships among elements and also between soil properties and elemental concentrations have been analysed. The RV obtained in this study were (mg kg⁻¹): Se 2.68, Li 115, Sr 298, Cd 0.97, Co 35, Cr 217, Cu 46, Ni 50, Pb 137, V 120, Zn 246, Fe 124,472, Mn 2691, and Ba 743. The RV for Se and Li were used as a preliminary approach to assess soil contamination in Spanish soils. The results confirm human impact on Sr, As, Cd, Cr, Cu, Ni, Pb and Zn soil concentrations, but evidence no deviation from natural Se, Li, Co, V, Fe, Mn and Ba concentrations. The results obtained from the statistical analysis reveal significant correlations between some elements and clay and soil organic matter (SOM) contents, indicating that metal concentrations are controlled by soil composition. One particularly interesting finding is the high correlation coefficients obtained between SOM and Se, Cd, Cr, V, Fe, and Mn, and between clay and Cd, Zn, V, Fe and Mn. Once again, these facts confirm the role of SOM and clay minerals in soil functions and that soil is an ecosystem element responsible for maintaining environmental quality.     

PHYSIOLOGICAL INHIBITORY EFFECT OF OCS IN ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA （TREBOUXIOPHYCEAE, CHLOROPHYTA）

Parietochloris incisa is an arachidonic acid-rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a prebable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto-inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto-inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.     

Learning with Local Help: Expanding the Dialogue on Climate Change and Water Management in the Okanagan Region, British Columbia, Canada

The research activity described in this report is a comprehensive regional assessment of the impacts of climate change on water resources and options for adaptation in the Okanagan Basin. The ultimate goal of the project is to develop integrated climate change and water resource scenarios to stimulate a multistakeholder discussion on the implications of climate change for water management in the region. The paper describes two main objectives: (a) providing a set of research products that will be of relevance to regional interests in the Okanagan, and (b) establishing a methodology for participatory integrated assessment of regional climate change impacts and adaptation that could be applied to climate-related concerns in Canada and other countries. This collaborative study has relied on field research, computer-based models, and dialogue exercises to generate an assessment of future implications, and to learn about regional views on the prospects for adaptation. Along the way, it has benefited from strong partnerships with governments, researchers, local water practitioners, and user groups. Building on the scenario-based study components, and a series of interviews and surveys undertaken for the water management and adaptation case study components, a set of stakeholder dialogue sessions were organized which focused on identifying preferred adaptation options and processes for their implementation. Rather than seeking consensus on the “best” option or process, regional interests were asked to consider a range of available options as part of an adaptation portfolio that could address both supply side and demand side aspects of water resources management in the Okanagan. The Canadian Crown reserves the right to retain a non-exclusive, royalty free licence in and to any copyright.     

Biogene,klastische und evaporitische Sedimentation in einem mesothermen monomiktischen ufernahen See (Golf von Aqaba)

The genesis and development of a monomictic, mesothermal lake and its sediments is demonstrated by the analysis of sediment cores from different parts of the lake and from different stages of development. The compounds which build up the sediments, consist of irregular large particles from the surrounding crystalline rocks, of fine grained silt sediments from catastrophic flud deposits, of evaporitic series, and algae mats. The thickness of the different layers and their distribution in various parts of the lake; the different compounds, absolute age determinations, the carbonate layers and algae mats allow the definition of different stages of development of the lake. Causes and influences of an unusual type of monomixis with summer turnover are discussed and related to the sedimentary environment. Annual fluctuations in physical and biological limnology lead to the development of annual cycles in mat development and evaporites, which are reflected in the varved sediments. Inorganic sedimentation of terrestrial sediments, evaporites and organic matter accumulation are in shifting equilibrium which can be analysed by changes in the sediment types. Within the zone of biologic decay of algae via photosynthetic and other sulfur bacteria and heterotrophic bacteria, biogenic aragonite, Mg-Calcite and sulfides are precipitated. The autigenic dolomite occuring within the algae mats could not be attributed to biological precipitation so far. The lake started out as a lagoon approximately 4500 years B.P. Algae mat development was initiated after the lagoon was separated from the open sea (2400 B.P.). The central parts of the lake subsided at a time between 1900 and 1600 B.P. At this time the algae mat deposition, which until then took place in the whole lake, was restricted to the remaining shallow parts. Years of extremely high precipitation and catastrophic floods are represented by silt layers in the western parts of the lake, while coarser terrestrial sediments are intercalated in the algae mats of the eastern parts. Oöids, carbonate laminae, oncoliths and other types of carbonate particles within the algae mats are defined as biogenic by SEM analyses and laboratory experiments.     

Controls on Sr/Ca and Mg/Ca in scleractinian corals: The effects of Ca-ATPase and transcellular Ca channels on skeletal chemistry

The Sr/Ca of aragonitic coral skeletons is a commonly used palaeothermometer. However skeletal Sr/Ca is typically dominated by weekly-monthly oscillations which do not reflect temperature or seawater composition and the origins of which are currently unknown. To test the impact of transcellular Ca²⁺ transport processes on skeletal Sr/Ca, colonies of the branching coral, Pocillopora damicornis, were cultured in the presence of inhibitors of Ca-ATPase (ruthenium red) and Ca channels (verapamil hydrochloride). The photosynthesis, respiration and calcification rates of the colonies were monitored throughout the experiment. The skeleton deposited in the presence of the inhibitors was identified (by ⁴²Ca spike) and analysed for Sr/Ca and Mg/Ca by secondary ion mass spectrometry. The Sr/Ca of the aragonite deposited in the presence of either of the inhibitors was not significantly different from that of the solvent (dimethyl sulfoxide) control, although the coral calcification rate was reduced by up to 66% and 73% in the ruthenium red and verapamil treatments, respectively. The typical precision (95% confidence limits) of mean Sr/Ca determinations within any treatment was <±1% and differences in skeletal Sr/Ca between treatments were correspondingly small. Either Ca-ATPase and Ca channels transport Sr²⁺ and Ca²⁺ in virtually the same ratio in which they are present in seawater or transcellular processes contribute little Ca²⁺ to the skeleton and most Ca is derived from seawater transported directly to the calcification site. Variations in the activities of Ca-ATPase and Ca-channels are not responsible for the weekly-monthly Sr/Ca oscillations observed in skeletal chronologies, assuming that the specificities of Ca transcellular transport processes are similar between coral genera.     

Leveraging similarity analysis to understand variability in movement behavior

The increasingly large volume of trajectories of moving entities obtained through GPS and cellphone tracking, telemetry, and other location-aware technologies motivates researchers to understand the implicit patterns hidden in movement trajectories and understand how movement is influenced by the environmental context. Trajectory similarity serves as an important tool in computational movement analysis and as the foundation of revealing those patterns. However, there are various trajectory similarity measures, each of which has its own strengths and weaknesses. In this article, we present a hierarchical clustering framework that integrates five commonly used similarity measures, including Fréchet distance, dynamic time warping, Hausdorff distance, longest common subsequence, and normalized weighted edit distance, a special kind of edit distance for movement analysis. The framework aims at clustering similar patterns and identifying variability in movement. The optimal number of clusters are first obtained. Then, the clusters are characterized by environmental variables to explore the associations between variability in movement and the environmental conditions. We evaluate the proposed framework using 15 years of tracking data of turkey vultures, tracked at 1- to 3-h sampling intervals, during their fall and spring migration seasons. The results suggest that, at 5% significance level, turkey vultures select their movement paths intentionally and those selections appear to be related to certain environmental context variables, including thermal uplift, vegetation state (observed indirectly through Normalized Difference Vegetation Index), temperature, precipitation, tailwind, and crosswind. And interestingly, there exist preferential differences among individuals. Although the preference of the same turkey vulture is not strictly consistent over different years, each individual tends to preserve a more similar preference over different years, compared with the preferences of other turkey vultures.