bluuebunny/crossref_metadata_2025 huggingface dataset:
Underway seawater and atmospheric measurements of volatile organic compounds in the Southern Ocean
Authors: Wohl Charel , Brown Ian , Kitidis Vassilis , Jones Anna E. , Sturges William T. , Nightingale Philip D. , Yang Mingxi
Published: February 2020

Abstract. Dimethyl sulfide and volatile organic compounds and are important for atmospheric chemistry. The oceanic emissions of biogenically derived gases, including dimethyl sulfide and especially isoprene, are not well constrained. The role of the ocean in the global budgets of atmospheric methanol, acetone and acetaldehyde is even more poorly known. In order to quantify the air-sea fluxes of these gases we measured their seawater concentrations and air mixing ratios in the Atlantic sector of the Southern Ocean, along a ~ 11 000 km long transect at approximately 60° S in Feb–Apr 2019. Concentrations, oceanic saturations and estimated fluxes of several simultaneously sampled volatile organic compounds (methanol, acetone, acetaldehyde, dimethyl sulfide and isoprene) are presented here. Campaign mean (± 1σ) surface water concentrations of dimethyl sulfide, isoprene, methanol, acetone and acetaldehyde were 2.60 (± 3.94), 0.0133 (± 0.0063), 67 (± 35), 5.5 (± 2.5) and 2.6 (± 2.7) nmol dm−3 respectively. In this dataset, seawater isoprene and methanol concentrations correlated positively. Furthermore, seawater acetone, methanol and isoprene concentrations were found to correlate negatively with the fugacity of carbon dioxide, possibly due to a common biological origin. Campaign mean (± 1σ) air mixing ratios of methanol, acetone and acetaldehyde were relatively low at 0.17 (± 0.08), 0.081 (± 0.031) and 0.049 (± 0.040) ppbv. We observed diel changes in averaged acetaldehyde concentrations in seawater and ambient air (and to a lesser degree also for acetone and isoprene), which suggest light-driven productions. Campaign mean (± 1σ) fluxes of 4.3 (± 7.4) µmol m−2 d−1 DMS and 0.028 (± 0.021) µmol m−2 d−1 isoprene are determined where a positive flux indicates from the ocean to the atmosphere. Methanol was largely undersaturated in the surface ocean with a mean (± 1σ) net flux of −2.4 (± 4.7) µmol m−2 d−1, but also had a few occasional episodes of outgassing This section of the Southern Ocean was found to be both a source and a sink for acetone and acetaldehyde this time of the year, depending on location, resulting in a mean flux of −0.55 (± 1.15) µmol m−2 d−1 for acetone and −0.28 (± 1.22) µmol m−2 d−1 for acetaldehyde. The data collected here will be important for constraining the oceanic source/sink of these gases and potentially help to elucidate the presence of common sources/sinks for these compounds.
Evaluation of CH4MODwetland and TEM models used to estimate global CH4 emissions from natural wetlands
Authors: Li Tingting , Lu Yanyu , Yu Lingfei , Sun Wenjuan , Zhang Qing , Zhang Wen , Wang Guocheng , Yu Lijun , Zhang Ran
Published: February 2020

Abstract. Reliable models are required to estimate global wetland CH4 emissions. This study aimed to test two process-based models, CH4MODwetland and TEM, against the CH4 flux measurements of marsh, swamps, peatland and coastal wetland sites across the world; specifically, model accuracy and generality were evaluated for different wetland types and in different continents, and then the global CH4 emissions from 2000 to 2010 were estimated. Both models showed similar high correlations with the observed seasonal CH4 emissions, and the regression of the observed versus computed total seasonal CH4 emissions resulted in R2 values of 0.78 and 0.72 by CH4MODwetland and TEM, respectively. The CH4MODwetland predicted more accurately in marsh, peatland and coastal wetlands, with model efficiency (EF) values of 0.22, 0.55 and 0.72, respectively; however, the model showed poor performance in swamps (EF
COSIPY v1.2 – An open-source coupled snowpack and ice surface energy and mass balance model
Authors: Sauter Tobias , Arndt Anselm , Schneider Christoph
Published: February 2020

Abstract. Glacial changes play a key role both from a socio-economical and political, and scientific point of view. The identification and the understanding of the nature of these changes still poses fundamental challenges for climate, glacier and water research. Many studies aim to identify the climatic drivers behind the observed glacial changes using distributed surface mass and energy balance models. Distributed surface mass balance models, which translate the meteorological conditions on glaciers into local melting rates, thus offer the possibility to attribute and detect glacier mass and volume responses to changes in the climatic forcings. A well calibrated model is a suitable test-bed for sensitivity, detection and attribution analyses for many scientific applications and often serves as a tool for quantifying the inherent uncertainties. Here we present the open-source coupled snowpack and ice surface energy and mass balance model in Python COSIPY, which provides a lean, flexible and user-friendly framework for modelling distributed snow and glacier mass changes. The model has a modular structure so that the exchange of routines or parameterizations of physical processes is possible with little effort for the user. The model has a modular structure so that the exchange of routines or parameterizations of physical processes is possible with little effort for the user. The framework consists of a computational kernel, which forms the runtime environment and takes care of the initialization, the input-output routines, the parallelization as well as the grid and data structures. This structure offers maximum flexibility without having to worry about the internal numerical flow. The adaptive sub-surface scheme allows an efficient and fast calculation of the otherwise computationally demanding fundamental equations. The surface energy-balance scheme uses established standard parameterizations for radiation as well as for the energy exchange between atmosphere and surface. The schemes are coupled by solving both surface energy balance and subsurface fluxes iteratively in such that consistent surface skin temperature is returned at the interface. COSIPY uses a one-dimensional approach limited to the vertical fluxes of energy and matter but neglects any lateral processes. Accordingly, the model can be easily set up in parallel computational environments for calculating both energy balance and climatic surface mass balance of glacier surfaces based on flexible horizontal grids and with varying temporal resolution. The model is made available on a freely accessible site and can be used for non-profit purposes. Scientists are encouraged to actively participate in the extension and improvement of the model code.
Little change in Palmer Drought Severity Index across global land under warming in climate projections
Authors: Yang Yuting , Zhang Shulei , Roderick Michael L. , McVicar Tim R. , Yang Dawen , Liu Wenbin , Li Xiaoyan
Published: February 2020

Abstract. Anthropogenic warming is reported to increase global drought for the 21st century when calculated using offline drought indices. However, this contradicts observations of greening and little systematic change in runoff over the past few decades and climate projections of future greening with slight increases in global runoff for the coming century. This calls into question the drought projections based on offline drought indices. To resolve this paradox, here we calculate a widely-used conventional drought index (i.e., the Palmer Drought Severity Index, PDSI) using direct outputs from 16 CMIP5 models (PDSI_CMIP5) such that the hydrologic consistency between PDSI_CMIP5 and CMIP5 models is maintained. Results show that the global PDSI_CMIP5 remains generally unchanged as climate warms, demonstrating that CMIP5 models do not actually project a general increase in PDSI drought (more reflecting soil moisture/agricultural drought) under future warming. Further analyses indicate that the projected increase in PDSI drought reported previously is primarily due to ignoring the vegetation response to elevated atmospheric CO2 concentration ([CO2]) in the offline calculations. On one hand, elevated [CO2] directly reduces stomatal opening; on the other hand, elevated [CO2] increases air temperature and thus vapor pressure deficit, which also causes partial stomatal closure. Finally, we show that the overestimation of PDSI drought can be avoided by directly using the relevant climate model outputs or by accounting for the effect of CO2 on evapotranspiration. Our findings refute the common warming leads to drying perception and highlight the importance of elevated CO2 in controlling future terrestrial hydrologic changes through vegetation responses.
Characterizing hillslope-stream connectivity with a joint event analysis of stream and groundwater levels
Authors: Beiter Daniel , Weiler Markus , Blume Theresa
Published: February 2020

Abstract. Hillslope-stream connectivity controls runoff generation, both during events and baseflow conditions. However, assessing subsurface connectivity is a challenging task, as it occurs in the hidden subsurface domain where water flow cannot be easily observed. We therefore investigated if the results of a joint analysis of rainfall event responses of near-stream groundwater levels and stream water levels could serve as a viable proxy for hillslope-stream connectivity. The analysis focuses on the extent of response, correlations, lag times and synchronicity. A newly developed data analysis scheme of separating the aspects of (a) response timing and (b) extent of water level change provides new perspectives on the relationship between groundwater and stream responses. In a second step we investigated if this analysis can give an indication of hillslope-stream connectivity at the catchment scale. Stream- and groundwater levels were measured at five different hillslopes over 5 to 6 years. Using a new detection algorithm we extracted 706 rainfall response events for subsequent analysis. Carrying out this analysis in two different geological regions (schist and marls) allowed us to test the usefulness of the proxy under different hydrological settings while also providing insight into the geologically-driven differences in response behaviour. For rainfall events with low initial groundwater level, groundwater level responses often lag behind the stream with respect to the start of rise and the time of peak. This lag disappears at high antecedent groundwater levels. At low groundwater levels the relationship between groundwater and stream water level responses to rainfall are highly variable, while at high groundwater levels, above a certain threshold, this relationship tends to become more uniform. The same threshold was able to predict increased likelihood for high runoff coefficients, indicating a strong increase in connectivity once the groundwater level threshold was surpassed. The joint analysis of shallow near-stream groundwater and stream water levels provided information on the presence or absence and to a certain extent also on the degree of subsurface hillslope-stream connectivity. The underlying threshold processes were interpreted as transmissivity feedback in the marls and fill-and-spill in the schist. The value of these measurements is high, however, time series of several years and a large number of events are necessary to produce representative results. We also find that locally measured thresholds in groundwater levels can provide insight into catchment-scale connectivity and event response. If the location of the well is chosen wisely, a single time series of shallow groundwater can indicate if the catchment is in a state of high or low connectivity.
Brief Communication: Update on the GPS Reflection Technique for Measuring Snow Accumulation in Greenland
Authors: Larson Kristine M. , MacFerrin Michael , Nylen Thomas
Published: February 2020

Abstract. GPS Interferometric Reflectometry (GPS-IR) is a technique that can be used to measure snow accumulation on ice sheets. The footprint of the method (~ 1000 m^2) is larger than many other in situ methods. A long-term comparison with hand-measurements yielded an accuracy assessment of 2 cm. Depending on the placement of the GPS antenna, these data are also sensitive to firn density. The purpose of this short note is to make public GPS-IR measurements of snow accumulation for four sites in Greenland, compare these records with in situ sensors, and to make available open source GPS-IR software to the cryosphere community.
Brief communication: Glacier thickness reconstruction on Mt. Kilimanjaro
Authors: Stadelmann Catrin , Fürst Johannes Jakob , Mölg Thomas , Braun Matthias
Published: February 2020

Abstract. Glaciers on Kilimanjaro are unique indicators for climatic changes in the tropical mid-troposphere of Africa. The history of severe glacier area loss raises concerns about an imminent future disappearance. Yet, the remaining ice volume is not well known. We reconstruct thickness maps for 2000 and 2011 for the Northern Icefield (NIF) and Kersten Glacier (KG) that are informed by ground-truth thickness measurements and multi-temporal satellite information. For 2011, we find mean thickness values of 26.6 and 9.3 m, respectively. The existing consensus estimate for global glacier ice thickness shows unrealistically thick values for KG in areas that are meanwhile ice-free.
Open system pingos as hotspots for sub-permafrost methane emission in Svalbard
Authors: Hodson Andrew Jonathan , Nowak Aga , Senger Kim , Redeker Kelly , Christiansen Hanne H. , Jessen Søren , Hornum Mikkel T. , Betlem Peter , Thornton Steve F. , Turchyn Alexandra V. , Olaussen Snorre , Marca Alina
Published: February 2020

Abstract. Methane release from beneath lowland permafrost represents an important uncertainty in the Arctic greenhouse gas budget. Our current knowledge is arguably best-developed in settings where permafrost is being inundated by rising sea level, which means much of the methane is oxidised in the water column before it reaches the atmosphere. Here we provide a different process perspective that is appropriate for Arctic fjord valleys, where local deglaciation causes isostatic uplift to out-pace rising sea level. We show how the uplift induces permafrost aggradation in former marine sediments, whose pressurisation results in methane escape directly to the atmosphere via ground water springs. In Adventdalen, Central Spitsbergen, we show how the springs are historic features, responsible for the formation of open system pingos, and capable of discharging brackish waters enriched with high concentrations of mostly biogenic methane (average 18 mg L−1). Thermodynamic calculations show that the methane concentrations sometimes marginally exceed the solubility limit for methane in water at 0 °C (41 mg L−1). In our case study, emissions from just four pingo springs with a combined discharge of less than 2 L s−1 increase the land-atmosphere methane flux by 16 %. This confirms that sub-permafrost methane migration deserves more attention for improved forecasting of Arctic greenhouse gas emissions.
Estimating statistical errors in retrievals of ice velocity and
deformation parameters from satellite images and buoy arrays
Authors: Dierking Wolfgang , Stern Harry , Hutchings Jennifer K.
Published: February 2020

Abstract. The objective of this note is to provide the background and basic tools to estimate the statistical error of deformation parameters that are calculated from displacement fields retrieved from synthetic aperture radar (SAR) imagery or from location changes of position sensors in an array. We focus here specifically on sea ice drift and deformation. In the most general case, the uncertainties of divergence/convergence, shear, vorticity, and total deformation are dependent on errors in coordinate measurements, the size of the area and the time interval over which these parameters are determined, and the velocity gradients within the boundary of the area. If displacements are calculated from sequences of SAR images, also a tracking error has to be considered. Timing errors in position readings are usually very small and can be neglected. We give examples for magnitudes of position and timing errors typical for buoys and SAR sensors, in the latter case supplemented by magnitudes of the tracking error, and apply the derived equations on geometric shapes frequently used for deriving deformation from SAR images and buoy arrays. Our case studies show that the size of the area and the time interval for calculating deformation parameters have to be chosen within certain limits to make sure that the uncertainties are smaller than the magnitudes of deformation parameters.
Importancia de los ‘insights’ en el proceso estratégico y creativo de las campañas publicitarias
Authors: Sebastián-Morillas Ana , Martín-Soladana Irene , Clemente-Mediavilla Jorge
Published: February 2020

En el presente trabajo se analiza la importancia del insight en el sector publicitario. Esto implica conocer su origen, así como su importancia en el proceso estratégico y creativo de las campañas publicitarias. Metodología. Se utiliza una metodología cualitativa mediante el método Delphi. Las entrevistas a expertos de la planificación estratégica muestran la utilización del insight en las agencias de publicidad a la hora de desarrollar campañas publicitarias eficaces. Resultados. Un buen insight contribuye a conectar la marca con el consumidor y ayuda a los anunciantes a cumplir los objetivos de sus campañas. Resultados. Para conseguir una publicidad eficaz el insight tiene que conectar con las personas, crear valor, identificación…, y aun así no se garantiza dicha efectividad. Conclusiones. No se puede atribuir la eficacia de las campañas publicitarias única y exclusivamente a un buen insight, también son importantes elementos como la creatividad o la estrategia, entre otros.
La opinión de los profesionales sobre la participación ciudadana en los medios de comunicación
Authors: Cáceres Zapatero María Dolores
Published: February 2020

Este trabajo presenta resultados de un Delphi realizado a profesionales de los medios a fin de conocer el impacto de la participación ciudadana en: 1) el uso que los medios hacen de las fuentes tradicionales y cómo han incorporado otras relacionadas con el periodismo ciudadano; 2) los cambios en las rutinas profesionales y en la aparición/transformación de géneros y formatos; 3) los cambios que afectan a la audiencia y su capacidad para estar bien informada. En suma, cuál es el sentido de estos cambios que se han producido en las pautas de consumo de medios, qué valor aporta el periodismo ciudadano a las noticias y si la sobreinformación actual está derivando en procesos de desinformación o, por el contrario, ha mejorado la capacidad de la audiencia para estar bien informada, mejorar la calidad democrática y contribuir a la construcción de una ciudadanía consciente y crítica.
La disputa por el liderazgo del PSOE en septiembre de 2016: Contenidos implícitos y marcos conceptuales
Authors: De la Iglesia Represa Francisco
Published: February 2020

A finales de septiembre de 2016 el Partido Socialista Obrero Español (PSOE) atravesó una de las mayores crisis internas desde su fundación. La pérdida de representación parlamentaria como consecuencia de la emergencia de nuevos partidos, la investidura fallida del líder socialista, la nueva convocatoria electoral que incrementa esta pérdida de representación o la posición respecto a la gobernabilidad del país en la XII legislatura son el contexto en el que se fraguó esta división. El análisis de los contenidos implícitos en los titulares de prensa nos permite observar las diferentes estrategias de persuasión ideológica empleadas en la transmisión del discurso político. El estudio de los marcos de referencia utilizados por los diferentes representantes del partido desvela, además, la evolución de la crisis del PSOE y los problemas de liderazgo que se ocultan tras el lenguaje empleado por sus protagonistas.
An Overview of the Abundance, Relative Mobility, Bioavailability, and Human Toxicity of Metals
Authors: Smith Kathleen S. , Huyck Holly L.O.
Published: February 2020

A major reason for considering the environmental geochemistry of mineral deposits is the environmental impact from such deposits on human, animal, and plant life. Some human activities may perturb or alter natural cycles of metals in the environment leading to accumulation of many potentially toxic metals in the food chain. To adequately assess the impact of human activities on metals in the environment, one must approach the issue from both a geological/geochemical/physical viewpoint and a biological/ biochemical/toxicological perspective.

This chapter provides a geochemical and a biological context for chapters in this volume that discuss specifics of environmental geochemistry of mineral deposits. We alternate between the geological/geochemical/physical and biological/biochemical/toxico- logical aspects of selected metals. Because the emphasis of this volume is the environmental geochemistry of mineral deposits, we present examples that relate to metals or mineral deposits rather than provide a review of the literature. We also place emphasis on geological, geochemical, and chemical factors that affect metal bioavailability and toxicity to highlight connections between the earth and biological sciences. Radioactive materials are beyond the scope of this chapter.
The Environmental Geology of Mineral Deposits
Authors: Plumlee G.S.
Published: February 2020

Mineral deposits are concentrations of metallic or other mineral commodities in the Earth's crust that result from a variety of complex geologic processes. The natural weathering and erosion of a mineral deposit at the Earth's surface disperses its constituents into the waters, soils, and sediments of its surrounding environment. There, the constituents may be taken up by plants and (or) organisms. The concentrations and chemical, mineralogical, or biological forms of metals and other constituents from a mineral deposit prior to mining in soils, waters, sediments, plants, and organisms are defined here to be the natural environmental signatures of the deposit.

Modern mining and mineral processing activities employ a wide variety of methods to prevent or minimize adverse environmental impacts (Ripley et al., 1996; Plumlee and Logsdon, 1999; references therein). However, if not carried out with appropriate mitigation and prevention practices (as was common in most historical operations), or as a result of accidental releases, mining and mineral processing can disperse potentially deleterious metals, other deposit constituents, and mineral processing chemicals or byproducts into the environment. Mining-related environmental signatures are defined here as the concentrations and chemical, mineralogical, or biological forms of these metals and chemicals prior to mitigation or remediation in mining and milling wastes, mine waters, mineral processing solutions and byproducts, and smelter emissions and byproducts.
Some Fundamentals of Aqueous Geochemistry
Authors: Nordstrom D. Kirk
Published: February 2020

Aqueous geochemistry is the application of chemistry to reactions between rock and natural water. Analytical chemistry, inorganic and organic chemistry, and physical chemistry are used to understand and interpret the dominant processes that effect a redistribution of the elements in man's environment. Examples of these processes are the dissolution and precipitation of minerals, adsorption and desorption of ions, oxidation-reduction or redox reactions, gas uptake or production, transformations involving organic matter, complexation and chelation, evaporation, ion exchange, and anthropogenic changes. In the field of aqueous geochemistry these processes are known to occur in a variety of environments including rain, fog, snow, soils, bedrock weathering, streams, rivers, lakes, estuaries, ground waters, subsurface brines, diagenetic environments, the formation and weathering of mineral deposits, and the global movement of elements and compounds. Aqueous geochemistry is synonymous with low-temperature geochemistry, where the approximate temperature and pressure limits of 0-100°C and 1-500 bars commonly apply. The term environmental geochemistry is often used to emphasize the environmental aspects of geochemistry. Another common term, hydrogeochemistry, is usually applied to the aqueous geochemistry of ground waters. These four terms all refer to the same basic subject matter.

In physics and chemistry, great advances are made through theoretical research, experimental research, or optimally through a blend of both. In aqueous geochemistry, a third aspect plays an essential role: field observations. By applying the best that theoretical chemistry and physics can offer to the interpretation of field observations aided by reliable experimental and analytical determinations, the aqueous geochemist is at the crossroads of theory, experiment and the natural environment. Geological phenomena are of a much greater complexity than the carefully controlled systems investigated in physics and chemistry, so that the geochemist has had to expand his knowledge creatively beyond the traditional boundaries of the physical sciences. The challenge of this type of scientific research is not generally appreciated (Alvarez, 1990). There are far more unknown and uncontrolled variables in natural systems than in the typical physicochemical investigation carried out in the laboratory. The hydrological, microbiological, macrobi- ological, and meteorological sciences are all necessary in addition to geology and chemistry.
Geochemical Processes Controlling Uranium Mobility in Mine Drainages
Authors: Wanty R.B. , Miller W.R. , Briggs P.H. , McHugh J.B.
Published: February 2020

Comprehensive models of ore genesis incorporate metal sources, transport and concentration mechanisms, and preservation mechanisms. Analogous concepts apply to the problem of metal migration from mines, mine wastes, and mine tailings, including: the concentrations, mineralogical occurrence, and availability of metals in mineral deposits, host rocks, mine wastes, and tailings (the source); the mechanisms for metal mobilization and transport during weathering; the mechanisms for metal fixation and the permanence of the fixation. Similarly, undisturbed mineral deposits or alteration zones that are exposed at the Earth's surface may be natural sources from which metals can be solubilized during weathering.

Uranium (U), a naturally-occurring radioactive element, may be present in mineral deposits in sufficient concentrations that in itself constitutes ore. It may also be present in ores of other metals at concentrations that exceed average crustal abundances. Any uranium that is not completely removed from these ores in the mining and milling process may be available for mobilization into ground or surface waters via the weathering and oxidation of solid tailings or mine waste piles. This chapter discusses the relative importance of various geochemical processes that control uranium mobility via weathering in both mined and unmined mineralized environments. The data presented in this paper focus on mined areas because the great extent of historic mining in the field areas examined for this study preclude extensive consideration of undisturbed areas.
Geochemistry of the Processes that Attenuate Acid Mine Drainage in Wetlands
Authors: Walton-Day Katherine
Published: February 2020

Because conventional treatment of acid-mine drainage (AMD) involves installation and maintenance of water treatment plants, regulators and mine operators have sought lower cost and lower maintenance technologies. One ecological engineering technology that has received increasing research attention is the use of natural and constructed wetlands for remediation of some of the water-quality problems associated with AMD. As surface water flows through a wetland, several processes can occur to decrease the elevated concentrations of sulfate, trace metals, arsenic, and hydrogen ions that characterize AMD. These processes range from precipitation of mineral phases to the active uptake of solutes by vegetation. The relative importance of these processes between different wetlands depends on the hydrologic and geochemical characteristics of the wetlands.

This paper describes the geochemistry of the processes that contribute to AMD attenuation in wetlands and presents some of the case studies that have identified these processes. The attenuation of AMD in wetlands has been studied in natural and in man- made (constructed) wetlands. In this paper, case studies of both are presented. A discussion of some of the general characteristics of wetlands is followed by more detailed discussions of the processes and geochemistry that contribute to the treatment of AMD in wetlands, relevant case studies, and a brief discussion of constructed wetland design. The physical, chemical, and hydrologic characteristics of a wetland that affect its potential for supporting specific types of reactions are also emphasized.
The Environmental Geochemistry of Cyanide
Authors: Smith A.C.S. , Mudder T.I.
Published: February 2020

“His ways precedeth his coming. We speaketh his name in fear and trembling (Anon, circa 451 AD).” Obscure perhaps, but these words of the Roman centurion about his foe Attila the Hun, immediately prior to the defeat of Attila at the Battle of Chalons-sur- Marne in 451 AD, reflect a similar perception within the community of the nature of cyanide. The status of cyanide as a social and environmental pariah is not founded in the technical literature but is emotionally driven, consequent perhaps from the historic use of cyanide by the agencies of law enforcement in the United States and in other jurisdictions to carry out capital punishment.

However, a technically based evaluation of the nature and behavior of cyanide in the environment leads to a more sympathetic view of the potential impact of this widely used industrial and mining chemical. In this chapter, we review the environmental geochemistry of cyanide in mining applications. We will first consider the extraction process chemistry for precious metal ores, a chemical process in which cyanide is a vital ingredient. We will then describe fundamental aspects of cyanide chemistry, and translate this chemistry to geochemical reactions and processes. The application of these processes and reactions forms the root of how cyanide migration and attenuation in the natural environment can be evaluated.
Effects of Heavy Metals on the Aquatic Biota
Authors: Kelly M.G.
Published: February 2020

This review focuses on the effects of heavy metals on the aquatic (primarily freshwater) biota. During the 1970s and 1980s there was intense research interest in the biological effects of heavy metals. While this has provided a firm foundation for the interpretation of toxic effects associated with metalliferous mining in particular, many other aspects of mining, with potentially adverse effects on the biota, have received less attention. In particular, physical factors, such as those associated with high suspended solid loads, for example, are studied comparatively rarely, although for many deposits of insoluble metals (e.g., gold, tin) such factors may be more significant than toxicity (LaPerriere et al., 1985; Van Nieuwenhuyse and LaPerriere, 1986; Briones, 1987). Moreover, discovery of a valuable mineral may lead to large increases in population. The town of Jos in Nigeria, for example, owes its existence to the tin mines in the region and the main water quality problem in the Delimi river downstream of the town is due to sewage pollution rather than to mining (Kelly and Ali, 1993). Further environmental impacts can include clearing land for agriculture to feed the growing population (Livett et al., 1979). It would be wrong to consider the potential impact of a new development without considering these aspects as well.
Geologic Controls on the Composition of Natural Waters and Mine Waters Draining Diverse Mineral-Deposit Types
Authors: Plumlee G.S. , Smith K.S. , Montour M.R. , Ficklin W.H. , Mosier E.L.
Published: February 2020

Sulfide-bearing mineral deposits formed in reduced conditions out of contact with an oxygenated atmosphere. When sulfides in the deposits are exposed by natural erosion or by mining to atmospheric oxygen and water, weathering of the sulfides can produce natural or mining-related acid-rock drainage. The prediction of water quality that results from mining and mineral processing activities has therefore become a high priority in the permitting of mining activities worldwide, in order to prevent the formation of or mitigate the environmental effects of deleterious drainage waters. In addition, estimating the compositions of natural waters that drained mineral deposits prior to mining is crucial to establish appropriate baseline environmental standards at mine sites.

There are a variety of techniques currently in use to predict the acidity or metal content of mine-drainage waters, most common of which are static and kinetic testing procedures. In static procedures such as acid-base accounting (White et al., 1997, 1999), the contents of acid-generating sulfide minerals from ores and wastes from a proposed mine are measured and balanced against the measured contents of acid-consuming minerals such as carbonates; based on this balance, the materials are determined to be acid generating or non-acid-generating. In kinetic tests such as column or humidity-cell tests (ASTM, 1996), samples of ores and wastes are allowed to react over a period of time under laboratory conditions with oxidized waters or moist air, and the pH and metal contents of the resulting leachates are then measured.
A Multi-Phased Approach to Predict Acid Production from Porphyry Copper-Gold Waste Rock in an Arid Montane Environment
Authors: Filipek L.H. , VanWyngarden T.J. , Papp C.S.E. , Curry J.
Published: February 2020

Acid rock drainage (ARD) is a solution of sulfuric acid and iron sulfate, formed mainly by the exposure of pyrite to oxygen and water. ARD typically has high concentrations of other heavy metals that are toxic to wildlife and is the single most significant environmental problem associated with mining of ore deposits containing sulfide minerals. Understanding the processes that produce ARD and developing accurate methods to predict and prevent it are therefore key to environmentally conscious mining of such deposits.

The chemical reactions involved in pyrite oxidation are discussed in detail by Nordstrom and Alpers (1999). Several factors affect the kinetics of pyrite oxidation and, thus, the formation of ARD. They include the rate of transportation of oxidant (oxygen or iron (III)) to the surface of the pyrite grain; the chemistry of any solution in contact with the pyrite; the presence of oxidizing bacteria; the morphology, crystallinity, and trace-element content of the pyrite; and the mineralogy of neighboring grains. Once pyrite has been oxidized, reaction with calcium and magnesium carbonates or with rapidly weathering basic silicates can neutralize the acid produced. The interplay of the factors that control the oxidation and neutralization processes ultimately determines whether ARD will occur.
Seasonal Variation in Metal Concentrations in a Stream Affected by Acid Mine Drainage, St. Kevin Gulch, Colorado
Authors: Kimball B.A.
Published: February 2020

Mining of mineral deposits in the Rocky Mountains has left a legacy of acidic inflows to otherwise pristine upland watersheds. Since 1986, the U.S. Geological Survey has studied physical, chemical, and biological processes that affect the transport and transformation of metals in St. Kevin Gulch, an acidic, metal-rich stream near Leadville, Colorado. Well-known chemical processes have been quantified in the context of on-going physical transport by defining the hydrology with instream tracer-dilution experiments. These processes affect the partitioning of metals between dissolved and colloidal transport phases. In this acidic stream, pH increases during snowmelt runoff. At the most acidic stream site, pH varies from 3.15 to 4.00 during seasonal changes. Conservative effects of dilution are quantified using manganese as a natural, conservative tracer. Aluminum, copper, and zinc also are relatively conservative throughout the seasonal changes. Sulfate and iron, on the other hand, are removed with respect to manganese. The loss of iron through precipitation of hydrous Fe oxide is consistent with thermodynamic calculations. The loss of sulfate, however, cannot be fully explained.
Uchucchacua
Authors: Petersen Ulrich , Mayta Oscar , Gamarra Luis , Vidal César E. , Sabastizagal Angel
Published: February 2020

Although known since at least 1897, Uchucchacua was first explored on a major scale by Compaúía de Minas Buenaventura since 1960. Narrow vein mining started in 1975, but orebodies discovered at depth enabled expansion to today’s 2,000-t/d operation, transforming “Chacua” into the largest primary silver producer in South America.

The ores occur in fractures and faults, as well as in pipes, irregular replacement bodies, and mantos hosted by Late Cretaceous limestone. Porphyritic dacite bodies are probably pre-, syn-, and postore. Most of the ore occurs in distal manganiferous exoskarn and limestone and is mineralogically diverse, consisting mostly of the following.

The grade of the ore mined varies between 16 and 20 oz/t Ag combined with about 10 percent Mn, 1.5 percent Zn, and 0.9 percent Pb. Between 75 and 80 percent of the reserves are high in silver and manganese, whereas about 7 percent contain high zinc and lead grades with only moderate silver and low manganese.

Logarithmic-grade graphs show very good positive linear correlations for zinc versus lead, moderate correlations for silver versus manganese, and arcuate correlation bands for silver or manganese versus zinc or lead. These relationships indicate that the outward zoning sequence is from lead-zinc to silver-manganese or vice versa. The corresponding longitudinal vein sections can generally be contoured unambiguously, showing that the bands of highest grades of lead and zinc coincide very well. The highest silver grades can be contoured convincingly as a band that is zoned outward and/or at a higher elevation than the lead and zinc bands. However, the manganese grades often require two high-grade bands: a main band that mostly coincides with the highest silver grades and a thinner upper band that may represent near-surface manganese enrichment.

Ore intervals in individual veins, pipes, and replacement bodies are up to 200 m in vertical extent. However, the elevations of these intervals change progressively, reflecting the overall geometry of the hydrothermal cell (or cells) responsible for the mineralization. In addition, postore faulting has displaced the ore intervals. As a result, ore has been found to date over a vertical interval of 600 m, between 4,730 and 4,040 m.

At surface, manganese oxide stains in the host limestone and limonite in fractures and faults indicate proximity to ore. Underground, multiple calcite veinlets constitute a guide to nearby orebodies. Geochemical anomalies of 60 to 80 ppm Ag have been documented up to 15 m from an orebody. By extrapolation, 10 ppm Ag anomalies may extend 25 m from ore, and 1 ppm Ag anomalies may attain 40 to 45 m. Ore continues to be found at depth as well as laterally and between known ore zones.
Early Language Development and Child Aggression
Authors: Ersan Ceyhun
Published: February 2020

Aggression observed in early childhood is considered to be an important problem. Multiple factors may play a decisive role in children’s aggressive behaviors. The aim of this study was to examine whether the receptive and expressive language skills of preschool children (39-75 months-old) had predictive role on the levels of physical and relational aggression. The sample of the present study consists of 109 preschool children (47 girls and 62 boys). The language development levels of children in the sample were evaluated by TEDIL (Turkish Early Language Development Test) and their aggression levels were evaluated via Preschool Social Behavior Scale which were filled by their teachers. Pearson product moment correlation coefficient and stepwise regression analysis were used to analyze the data. According to the findings of the study, there was a significant and negative relationship between children’s receptive and expressive language skills and physical and relational aggression levels. The results of regression analysis revealed that physical aggression was negatively and significantly predicted by expressive language skills. In addition, relational aggression is negatively and significantly predicted by both receptive and expressive language skills. The increase in children's language skills significantly explains the decrease in physical and relational aggressive behaviors. The relationship between language skills and aggressive behaviors of Turkish preschool children was examined for the first time in this study. It is thought that the present study will contribute to the literature since it reveals the current situation in terms of the relationships between children's language skills and aggression levels and provide opportunities to make comparisons with the results of international studies.
Das Brexit-Abkommen und Europarecht
Authors: Frau Robert
Published: February 2020

This book analyses the legality of the Brexit agreement under European Union law. While the political debate has been highly publicised in recent months, a legal analysis was always lacking. This legal analysis deals with the interpretation and application of the draft withdrawal agreement, the ECJ’s responsibilities, EU citizenship for British citizens after Brexit, the framework within which British authorities can apply EU law, creating laws after Brexit as well as the law on movement of goods and customs. This monograph compares the agreement with other manifestations of integration and association throughout the European Union, and it deals with the ECJ’s jurisprudence extensively. Last but not least, it applies the agreement to the external economic law of the EU. Beyond Brexit, the monograph proposes a framework for the application of EU law by a non-member state.
Der länderbezogene Bericht des § 138a AO
Authors: Skupien Andreas
Published: February 2020

Die Arbeit untersucht angesichts der international angestrebten Transparenz von multinationalen Konzernen gegenüber internationalen Steuerbehörden den länderbezogenen Bericht, der Konzerne einer bestimmten Größenordnung zu einer jährlichen Übermittlung von Betriebskennzahlen an die Steuerbehörden verpflichtet. Der länderbezogene Bericht fand aufgrund der Richtlinie 2016/881/EU zur Änderung der EU-Amtshilferichtlinie Umsetzung in nationales Recht, mit dessen Hilfe insbesondere unangemessene Verrechnungspreisgestaltungen erkennbar werden sollen.

Der Schwerpunkt der Arbeit bildet eine kritische Untersuchung der deutschen Umsetzung des länderbezogenen Berichts in § 138a AO. Der Autor zeigt Abweichungen von den OECD-Empfehlungen und EU-Vorgaben auf und überprüft die Regelung mit höherrangigem Recht. Im Fokus stehen ferner der automatische Informationsaustausch der Berichtsdaten und die Untersuchung der Austauschgrundlagen. Am Ende widmet sich der Autor dem Rechtsschutz und Schadensersatz.
Impact of a Strength Intervention Program on Change of Hamstrings: Quadriceps Ratio and on Change of 1 Repetition Maximum
Authors: Hammerová Tereza , Králová Tereza , Cacek Jan , Kalina Tomáš , Hlavoňová Zuzana , Ondráček Jan
Published: February 2020

The relationship between the muscular strength of hamstrings and quadriceps and their possible muscular imbalance is considered by many authors as one of the causes of knee joint injury. The aim of this work is to assess the exercise program including squat modifications both in terms of progression of lower limb strength and in terms of possible change of H: Q ratio. Probands were divided into five groups (one control, four experimental). The experimental groups practiced the intervention program twice a week for eight weeks (EX1: Barbell squat, EX2: Barbell half squat, EX3: Barbell half squat with countermovement). In one training session participants repeated the exercise five times in six series. All experimental groups exhibited significant differences in mean values (p < 0.01), indicating the progression of lower limb strength measured by 1RM for barbell squat. The differences in the mean values of the H: Q ratio measured on an isokinetic dynamometer in the isokinetic test mode at angular velocities of 60 and 300 degrees per second do not show statistically significant differences (p = 0.99338). The established strength intervention program is suitable for the development of lower limb strength and does not show any changes in the H: Q ratio.
The Determinants of Motivation Regarding Top Competitive Basketball of Juniors
Authors: Šimková Katarína , Válková Hana
Published: February 2020

The motivation plays an essential role in carrying out any activity in people´s lives. It is a critical aspect between individual stages of career transitions and its goals. The purpose is to describe the determinants of the motivation and adherence of junior basketball players. The research interviews 40 players who wish to continue at the professional stage. The Career Transition theory (Alfermann & Stambulova, 2007) is a scope for the research. The research is qualitative, using The Grounded Theory by Strauss and Corbin (1990). The chosen research instrument was a semi-structured interview. The sample consists of twenty girls and twenty boys between ages 15-18. The results illustrate eight determinants of motivation and adherence. 1.lifestyle, 2.the perception of competencies, 3.specifics of basketball, 4.biopsychosocial health. 5.enjoyment, 6.team spirit, 7.society, 8.time management. Time management is the most occurring reason for termination of the basketball career.
Prevalence of Intracranial Aneurysm in Patients with Aortopathy: A Systematic Review with Meta-Analyses
Authors: Yu Xinyu , Xia Liangtao , Jiang Qingqing , Wei Yupeng , Wei Xiang , Cao Shiyi
Published: February 2020

Background and Purpose Patients with aortic disease might have an increased risk of intracranial aneurysm (IA). We conducted this research to assess the prevalence of IA in patients with aortopathy, considering the impact of gender, age, and cardiovascular risk factors.Methods We searched PubMed and Scopus from inception to August 2019 for epidemiological studies reporting the prevalence of IA in patients with aortopathy. Random-effect meta-analyses were performed to calculate the overall prevalence, and the effect of risk factors on the prevalence was also evaluated. Anatomical location of IAs in patients suffered from distinct aortic disease was extracted and further analyzed.Results Thirteen cross-sectional studies involving 4,041 participants were included in this systematic review. We reported an estimated prevalence of 12% (95% confidence interval [CI], 9% to 14%) of IA in patients with aortopathy. The pooled prevalence of IA in patients with bicuspid aortic valve, coarctation of the aorta, aortic aneurysm, and aortic dissection was 8% (95% CI, 6% to 10%), 10% (95% CI, 7% to 14%), 12% (95% CI, 9% to 15%), and 23% (95% CI, 12% to 34%), respectively. Gender (female) and smoking are risk factors related to an increased risk of IA. The anatomical distribution of IAs was heterogeneously between participants with different aortic disease.Conclusions According to current epidemiological evidence, the prevalence of IA in patients with aortic disease is quadrupled compared to that in the general population, which suggests that an early IA screening should be considered among patients with aortic disease for timely diagnosis and treatment of IA.