Accumulation of cadmium in extracellular granules in the kidney of the bivalve mollusc Mercenaria mercenaria (L.)

As part of an ongoing investigation of the transport, accumulation and excretion of metals in the infaunal eulamellibranch Mercenaria mercenaria (L.) organisms were exposed to radioactive cadmium followed by an autoradiographic study of the kidney tissue to determine the morphological sites of cadmium accumulation. Preliminary results of these studies indicate that cadmium is associated with large extracellular granules in the lumina of the kidneys. The presence of radioactive cadmium was determined morphometrically by counting developed silver grains on sections coated with a photographic emulsion. The results were statistically significant (99·9 % confidence—Student's t-test) to show that more radioactive cadmium was associated with large granules than with the background tissue.     

Localized multi-scale energy and vorticity analysis: II. Finite-amplitude instability theory and validation

A novel localized finite-amplitude hydrodynamic stability analysis is established in a unified treatment for the study of real oceanic and atmospheric processes, which are in general highly nonlinear, and intermittent in space and time. We first re-state the classical definition using the multi-scale energy and vorticity analysis (MS-EVA) developed in Liang and Robinson [Liang, X.S., Robinson, A.R., 2005. Localized multiscale energy and vorticity analysis. I. Fundamentals. Dyn. Atmos. Oceans 38, 195–230], and then manipulate certain global operators to achieve the temporal and spatial localization. The key of the spatial localization is transfer-transport separation, which is made precise with the concept of perfect transfer, while relaxation of marginalization leads to the localization of time. In doing so the information of transfer lost in the averages is retrieved and an easy-to-use instability metric is obtained. The resulting metric is field-like (Eulerian), conceptually generalizing the classical formalism, a bulk notion over the whole system. In this framework, an instability has a structure, which is of particular use for open flow processes. We check the structure of baroclinic instability with the benchmark Eady model solution, and the Iceland–Faeroe Frontal (IFF) intrusion, a highly localized and nonlinear process occurring frequently in the region between Iceland and Faeroe Islands. A clear isolated baroclinic instability is identified around the intrusion, which is further found to be characterized by the transition from a spatially growing mode to a temporally growing mode. We also check the consistency of the MS-EVA dynamics with the barotropic Kuo model. An observation is that a local perturbation burst does not necessarily imply an instability: the perturbation energy could be transported from other processes occurring elsewhere. We find that our analysis yields a Kuo theorem-consistent mean–eddy interaction, which is not seen in a conventional Reynolds stress framework. Using the techniques of marginalization and localization, this work sets up an example for the generalization of certain geophysical fluid dynamics theories for more generic purposes.     

History of forest hydrology

Hydrology as a science and a technology is examined, as are some of the myths on the role of forests in hydrology and water resources. The history of catchment area research is traced, in Europe, in the USA and in East Africa, with particular reference to forest hydrology and, in the earlier years, to water quantity rather than water quality. The importance of associating physical process studies with hydrological systems' investigations, to enhance understanding of why particular catchments behave as they do, is stressed. Recent advances in hydrochemistry have been exploited to elucidate water flow paths within experimental catchments. Stimulated by requirements for research into acidification of surface waters, research catchments have proved to be valuable outdoor laboratories from which a much improved understanding of the flow processes has been achieved. Conflicting claims about the impacts of forestry are described and discussed.     

An Evaluation of Methods for the Chemical Decomposition of Geological Materials for Trace Element Determination using ICP-MS

Complete dissolution is essential to obtain accurate analytical results using ICP-MS. In this study, decomposition techniques (i.e. acid digestions using Savillex Teflon vials, a high pressure digestion system and microwave oven, a combined lithium tetraborate fusion - HF/HNO3 acid decomposition and sodium peroxide sinter) for the total dissolution of different types of geological reference materials have been investigated. Savillex Teflon vial HF/HNO3 digestion is effective for basaltic samples. The high pressure HF/HClO4 digestion (PicoTrace TC-805 digestion system, Bovenden, Germany) allows dissolution of basalts and ironstones. Granites and magnetite-rich samples can be dissolved using a high pressure HF/H₂SO₄ method. Geological samples cannot be effectively attacked by microwave acid digestion. A combined lithium tetraborate fusion - HF/HNO3 acid digestion method allows complete dissolution of many different types of geological materials; however, this method precludes the determination of volatile elements due to the high fusion temperature (1000 °C). A sodium peroxide sinter method at 480 °C has the potential for the rapid determination of Y, Sc and REE in different types of geological materials. However, the lack of ultra-pure reagents precludes the use of lithium tetraborate fusion and sodium peroxide sinter methods for the measurement of geological samples with low trace element abundances.     

Factors affecting rural landholders’ adaptation to climate change: Insights from formal institutions and communities of practice

This study explores the factors affecting rural landholders’ adaptation to climate change from the perspectives of formal institutions and communities of practice. Semi-structured interviews were conducted with formal institutions (e.g. South Australian government agencies) and communities of practice (e.g. farm systems groups) within two natural resource management regions in South Australia. Both groups noted that rural landholders autonomously adapt to a variety of risks, including those induced by climate variability; however, the types and levels of adaptation varied among individuals as a result of variety of barriers to adaptation. The lack of communication and engagement processes established between formal institutions and communities of practice was one major barrier. The paper presents and discusses a model for transferring knowledge and information on climate change among formal institutions, communities of practice, trusted individual advisors and rural landholders, and for supporting the co-management of climate change across multiple groups in rural agricultural areas in Australia and elsewhere.     

The origin, deposition, and alteration of the organic material in Green River shale

Characteristics of the organic material in Green River Formation shale suggest that this material was derived from algae that grew in ancient Eocene lakes. The basin depressions for these nonmarine lakes were formed by the uplifting of the Rocky Mountain ranges. Large quantities of soluble salts flowed into these basins from the mountain streams, increasing the salinity of the lake waters until they became chemically stratified. In the upper, relatively fresh-water section of the lakes, abundant quantities of microscopic algae and other biota grew. Lesser amounts of terrestrial plant life remains were supplied in the form of wind- or water-borne spores and in the form of water-soluble organic materials entering the in-flowing waters. The lower section of the lake waters became highly reducing and stagnant because of lack of seasonal oxidative turnovers, thus providing ideal conditions for the accumulation and preservation of the organic debris from the lake biota.Precipitation of mineral carbonates and silicates from the highly saline waters provided most of the minerals that were co-deposited with the organic matter. Carbon dioxide, which evolved from the aquatic plant life, probably influenced mineral carbonate precipitation. During the life span of a few million of years the characteristics of the lake waters varied considerably and had significant effect upon the composition of both the inorganic and organic constituents of the Green River shale.Sixty to seventy-five core samples from each of three basins of the Green River Formation were analyzed for changes in both the organic and inorganic constituents. Considerable differences in the organic components of the soluble bitumen and of the insoluble kerogen were evident. Some of these differences appeared to be related to depth of burial and some to source material and the environment of the lake waters. Compositional differences relative to lithologic differences in the sediments of the three basins were found.     

Fresh Water Inflow and Oyster Productivity in Apalachicola Bay,FL (USA)

Apalachicola Bay lies at the mouth of the Apalachicola River, where seasonally variable freshwater inflows and shifting winds have long been thought to contribute to the support of an unusually productive and commercially important oyster fishery. Links between the river and productivity have been shown to lie in salinity-induced reductions in oyster predators and oyster disease as well as organic supplements from an extensive floodplain. Several studies have also indicated that nitrogen (N) and phosphorous (P) carried by the river are important in fertilization of bay primary production. While there is concern that upstream water withdrawals may impact the fishery, the importance of riverine N to oyster diets remains unclear. We measured N and carbon (C) stable isotopes (δ¹⁵N, δ¹³C) in macroalgae, surface-water nitrate, and surface sediments, which showed a gradient from enriched riverine δ¹⁵N values to more depleted values in the Gulf of Mexico. In contrast, δ¹³C of particulate matter is depleted in the river and enriched offshore. Oyster stable isotope values throughout Apalachicola Bay are more complex, but are dominated by freshwater inputs and reflect the variability and hydrodynamics of the riverine inflows.