Physical characterization,magnetic measurements,REE geochemistry and biomonitoring of dust load accumulated during a protracted winter fog period and their implications

The winter fog in India is a recurrent phenomenon for more than a decade now affecting the entire Himalayan and sub-Himalayan regions covering an area of nearly 500,000 km². Every winter (December–January), the air and surface transports in cities of northern India (Amritsar, New Delhi, Agra, Gwalior, Kanpur, Lucknow, and Allahabad) are severely disrupted with visibility reduced to <50 m at times. Since dust particles are known to act as nuclei for the fog formation, this study is aimed to carry out physicochemical characterization of the dust particulates accumulated during a protracted fog period from one of the severely fog affected cities of north India (Allahabad; 25°27′33.40″N–81°52′45.47″E). The dust-loaded tree leaves belonging to Ficus bengalensis and Ficus religiosa from 50 different locations between January 24 and 31, 2010 are sampled and characterized. The mass of dust, color, grain shape, size, phase constituents, and mineral magnetic parameters, such as magnetic susceptibility, SIRM, χ _fd%, and S-ratio, show minor variation and the regional influence outweighs local anthropogenic contributions. The dust compositions show fractionated rare earth element pattern with a pronounced negative Eu anomaly similar to upper continental crust and further suggesting their derivation from sources located in parts of north and central India.     

Evaluation of confocal laser scanning microscopy for enumeration of virus-like particles in aquatic systems

Abundances of virus-like particles (VLPs, mostly bacteriophages) are high in aquatic environments; therefore, techniques for precise enumeration are essential in ecological monitoring. VLPs were determined after staining with SYBR Gold by conventional epifluorescence microscopy and compared to enumerations performed by confocal laser scanning microscopy (CLSM). In order to assess the potential of CLSM for viral direct counts (VDCs), we processed samples from different freshwater and marine systems. Optical sectioning by CLSM and production of an overlay picture of multiple scans enables the often uneven whole investigated filter area to be brought to the plane of focus. This allows for subsequent image analysis of digitally created high-quality images. Another advantage using the CLSM was that the short spot excitation of the stain via laser beam minimized fading of the stain. The VDC results show that there is no significant difference between the two methods. Regarding the known difficulties of viral abundance estimates on particulate material, CLSM was further applied to enumerate VLPs on a small set of marine transparent exopolymeric particles sampled from the Atlantic Ocean. Our data suggest that CLSM is a useful tool to count viruses in water samples as well as attached to certain types of aquatic aggregates.     

Public support for carrot,stick, and no-government water quality policies

Public support for environmental policy provides an important foundation for democratic governance. Numerous policy innovations may improve nonpoint source pollution, but little research has examined which types of individuals are likely to support various runoff reduction policies. We conducted a household mail survey of 1136 residents in southern Wisconsin. In general, residents were more likely to support water quality policies if they were communitarians, egalitarians, concerned about water pollution, and perceived water quality as poor. The majority of respondents somewhat to strongly supported all of the seven proposed water quality policies, but opposed relying on voluntary action without government involvement on farms. Residents had higher support for incentives and market-based approaches (carrot policies) than regulation and taxes (stick policies). A more complicated pattern emerged in within-subject comparisons of residents’ views of carrot and stick approaches. Stick approaches polarized respondents by decreasing support among people with individualistic worldviews, while slightly increasing support among people with communitarian worldviews. Residents with an agricultural occupation were more likely to support voluntary, non-governmental approaches for reducing agricultural runoff, and were also more likely to support regulation for reducing urban lawn runoff. This research highlights the dominant role of cultural worldviews and the secondary roles of water pollution concern, perceived water quality, and self-interest in explaining support for diverse policies to reduce nonpoint source pollution.     

Steel slag carbonation in a flow-through reactor system:The role of fluid-flux

Steel production is currently the largest industrial source of atmospheric CO2. As annual steel production continues to grow, the need for effective methods of reducing its carbon footprint increases correspondingly. The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace(BOF) steel production, in particular its major constituent, larnite {Ca2Si O4}, which is a structural analogue of olivine {(Mg Fe)2Si O4}, the main mineral subjected to natural carbonation in peridotites, offers the potential to offset some of these emissions. However, the controls on the nature and efficiency of steel slag carbonation are yet to be completely understood. Experiments were conducted exposing steel slag grains to a CO2–H2O mixture in both batch and flow-through reactors to investigate the impact of temperature, fluid flux, and reaction gradient on the dissolution and carbonation of steel slag. The results of these experiments show that dissolution and carbonation of BOF steel slag are more efficient in a flow-through reactor than in the batch reactors used in most previous studies. Moreover, they show that fluid flux needs to be optimized in addition to grain size, pressure, and temperature, in order to maximize the efficiency of carbonation. Based on these results, a two-stage reactor consisting of a high and a low fluid-flux chamber is proposed for CO2 sequestration by steel slag carbonation,allowing dissolution of the slag and precipitation of calcium carbonate to occur within a single flow-through system.     

An exquisitely preserved troodontid theropod with new information on the palatal structure from the Upper Cretaceous of Mongolia

Troodontidae is a clade of small-bodied theropod dinosaurs. A new troodontid, Gobivenator mongoliensis gen. et sp. nov., is described based on the most complete skeleton of a Late Cretaceous member of this clade presently known, from the Campanian Djadokhta Formation in the central Gobi Desert. G. mongoliensis is different from other troodontids in possessing a pointed anterior end of the fused parietal and a fossa on the surangular in front of the posterior surangular foramen. The skull was superbly preserved in the specimen and provides detailed information of the entire configuration of the palate in Troodontidae. Overall morphology of the palate in Gobivenator resembles those of dromaeosaurids and Archaeopteryx, showing an apparent trend of elongation of the pterygoid process of the palatine and reduction of the pterygopalatine suture toward the basal Avialae. The palatal configuration suggests that the skull of Gobivenator would have been akinetic but had already acquired prerequisites for later evolution of cranial kinesis in birds, such as the loss of the epipterygoid and reduction in contact areas among bones.     

The governance of ecosystem services in river basins: An approach for structured data representation and analysis

River basins provide a wide range of ecosystem services important for human well-being. Ecosystem functions and their value to humans have been thoroughly studied. However, the role of governance characteristics for the sustainable management of ecosystem services has been largely ignored up to now. To close this gap, this article introduces the latest modifications to a database building on the Management and Transition Framework (MTF) that serve to study the relationship between water governance and management systems and their performance with regard to impacts on ecosystem services. This comprehensive approach facilitates structured data collection and representation in order to analyze single case studies or compare case studies regarding the governance and management of water resources and associated ecosystem services. It allows the user to investigate whether certain water governance characteristics, such as stakeholder involvement or vertical integration of governance levels, are associated with a change in the management of ecosystem services or a measurable change in their state. A simplified case from South Africa shows how the database modifications allow addressing links between governance and management processes on the one side and ecosystem services and the way they are handled on the other side. Applying the MTF database leads to evidence-based insights into best practices as well as failed management approaches and interventions. This in turn provides knowledge that can be transferred from science to practice supporting sustainable governance of ecosystem services.     

Spectral Analysis of Chemical Time Series from Long-Term Catchment Monitoring Studies: Hydrochemical Insights and Data Requirements

Hydrological and hydrochemical data from long-term monitoring stations are vital for inferring travel times and flowpaths of water, and transport of contaminants through catchments. Spectral analysis is particularly powerful for studying the hydrological and chemical dynamics of catchments across a wide range of time scales. Here, recent work is reviewed that illustrates how spectral analyses of long-term monitoring data can be used to infer the travel-time distribution of water through catchments, and to measure the chemical retardation of reactive solutes at the catchment scale. For spectral analysis, it is desirable to have data sets with high sampling frequency and long periods of coverage. Using two data sets, a 3-yr daily data series and a 17-yr weekly data series from the Hafren catchment at Plynlimon, Wales, we demonstrate that high-frequency sampling (e.g., daily or more frequent) is particularly useful for revealing the short-term chemical dynamics that most clearly reflect the interplay of subsurface chemical and hydrological processes. However, data sets that combine high-frequency sampling during storm events with low-frequency sampling between storms can cause spectral artifacts and must be treated with special care.     

Climate of the earth: an overview

Climate has varied over a large range in the recent history of the Earth, with extremes represented by equable environments of the Cretaceous and Eocene and the comparatively frigid conditions of the ice ages that punctuated the past few million years. It is suggested that major shifts in climate are controlled largely by variations in CO(2) with related fluctuations in modes of ocean circulation. Changes in climate can proceed rapidly, on time scales as short as centuries or even decades, as indicated by data for the Younger Dryas (a period of globally cold conditions interrupting recovery of the Earth from the last ice age) and the Little Ice Age (a cold snap extending from about 1250 to about 1850 ad). Rapid fluctuations in climate appear to be linked to changes in production of deep water in the North Atlantic, possibly also to variations in circulation of intermediate waters in the Pacific. Mechanisms are discussed whereby changes in ocean circulation can result in shifts of climate on a global scale. A 10 000 year record of climate from Norway is used to provide context for a discussion of possible changes in climate today arising as a result of the build-up of industrially related greenhouse gases. Brief, somewhat pessimistic, comments are offered concerning the prospects for meaningful near-term predictions of the response of climate to increased concentrations of greenhouse gases. Studies of past climates, by drawing attention to important processes and feedbacks, can play a valuable role in the development of credible models for the future.