Comparison of Hydrology of Wetlands in Pennsylvania and Oregon (USA) as an Indicator of Transferability of Hydrogeomorphic (HGM) Functional Models Between Regions

The hydrogeomorphic (HGM) approach to wetland classification and functional assessment is becoming more widespread in the United States but its use has been limited by the length of time needed to develop appropriate data sets and functional assessment models. One particularly difficult aspect is the transferability among geographic regions of specific models used to assess wetland function. Sharing of models could considerably shorten development and implementation of HGM throughout the United States and elsewhere. As hydrology is the driving force behind wetland functions, we assessed the comparability of hydrologic characteristics of three HGM subclasses (slope, headwater floodplain, mainstem floodplain) using comparable long-term hydrologic data sets from different regions of the United States (Ridge and Valley Province in Pennsylvania and the Willamette Valley in Oregon). If hydrology by HGM subclass were similar between different geographic regions, it might be possible to more readily transfer extant models between those regions. We found that slope wetlands (typically groundwater-driven) had similar hydrologic characteristics, even though absolute details (such as depth of water) differed. We did not find the floodplain subclasses to be comparable, likely due to effects of urbanization in Oregon, regional differences in soils and, perhaps, climate. Slight differences in hydrology can shift wetland functions from those mediated by aerobic processes to those dominated by anaerobic processes. Functions such as nutrient cycling can be noticeably altered as a result. Our data suggest considerable caution in the application of models outside of the region for which they were developed.     

DNA Heat Treatment for Improving qPCR Analysis of Human Adenovirus in Wastewater

PCR inhibitory substances in complex sample matrices can cause false negatives or under-estimation of target concentration. This study assessed DNA heat treatment for reducing inhibition during qPCR analysis of human adenovirus (HAdV) in wastewater samples. Inhibition was reduced by heat treating DNA, where mean HAdV concentration was increased by 0.71 log₁₀ GC/L (and up to 3.04 log₁₀ GC/L in one case), and replicate variability and false negatives were reduced. DNA heat treatment should be further investigated for improving reliability of HAdV concentration estimates in water, which can support more accurate assessment of health risks associated with viral pathogen exposure.     

Fossil insect evidence for the end of the Western Settlement in Norse Greenland

The fate of Norse farming settlements in southwest Greenland has often been seen as one of the great mysteries of North Atlantic colonization and expansion. Preservation of organic remains in the permafrost of the area of the Western Settlement, inland from the modern capital Nuuk, allowed very detailed study of the phases of occupation. Samples were taken from house floors and middens during the process of archaeological excavations and from insect remains were abstracted and identified in the laboratory. In this study, we present a new paleoecological approach principally examining the fossil fly faunas from house floors. The results of our study provide contrasting detailed pictures of the demise of two neighboring farms, Gården under Sandet and Nipaatsoq, one where abandonment appears as part of a normal process of site selection and desertion, and the other where the end was more traumatic. The level of detail, which was obtained by analysis of the dipterous (true fly) remains, exceeds all previous work and provides insights otherwise unobtainable.     

Processing and Morphology Impacts on Mechanical Properties of Fungal Based Biopolymer Composites

Fungal based biopolymer matrix composites with lignocellulosic agricultural waste as the filler are a viable alternative for some applications of synthetic polymers. This research provides insight into the impact of the processing method and composition of agriwaste/fungal biopolymer composites on structure and mechanical properties. The impact of nutrition during inoculation and after a homogenization step on the three-point bend flexural modulus and strength was determined. Increasing supplemental nutrition at inoculation had little effect on the overall composite strength or modulus; however, increasing carbohydrate loading after a homogenization step increased flexural stress at yield and bulk flexural modulus. The contiguity of the network formed was notably higher in the latter scenario, suggesting that the increase in modulus and strength of the final composite after homogenization was the result of contiguous hyphal network formation, which improves the integrity of the matrix and the ability to transfer load to the filler particles.     

Algal biomass derived biochar anode for efficient extracellular electron uptake from <Emphasis Type="Italic">Shewanella oneidensis</Emphasis> MR-1

The development of cost-effective and highly efficient anode materials for extracellular electron uptake is important to improve the electricity generation of bioelectrochemical systems. An effective approach to mitigate harmful algal bloom (HAB) is mechanical harvesting of algal biomass, thus subsequent processing for the collected algal biomass is desired. In this study, a low-cost biochar derived from algal biomass via pyrolysis was utilized as an anode material for efficient electron uptake. Electrochemical properties of the algal biochar and graphite plate electrodes were characterized in a bioelectrochemical system (BES). Compared with graphite plate electrode, the algal biochar electrode could effectively utilize both indirect and direct electron transfer pathways for current production, and showed stronger electrochemical response and better adsorption of redox mediators. The maximum current density of algal biochar anode was about 4.1 times higher than graphite plate anode in BES. This work provides an application potential for collected HAB to develop a cost-effective anode material for efficient extracellular electron uptake in BES and to achieve waste resource utilization.

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Assessment of the individual and mixture toxicity of cadmium,copper and oxytetracycline,on the embryo-larval development of the sea urchin <Emphasis Type="Italic">Paracentrotus lividus</Emphasis>

Multiple pollutions by trace metals and pharmaceuticals have become one of the most important problems in marine coastal areas because of its excessive toxicity on organisms living in this area. This study aimed to assess the individual and mixture toxicity of Cu, Cd, and oxytetracycline frequently existing in the contaminated marine areas and the embryo-larval development of the sea urchin Paracentrotus lividus. The individual contamination of the spermatozoid for 1 h with the increasing concentrations of Cd, Cu, and OTC decreases the fertility rate and increases larvae anomalies in the order Cu > Cd > OTC. Moreover, the normal larva frequency and the length of spicules were more sensitive than the fertilization rate and normal gastrula frequency endpoints. The mixture toxicity assessed by multiple experimental designs showed clearly that concentrations of Cd, Cu, and OTC superior to 338 μg/L, 0.56 μg/L, and 0.83 mg/L, respectively, cause significant larva malformations.     

Decomposition of dichloromethane and in situ alkali absorption of resulting halogenated products by a packed-bed non-thermal plasma reactor

For an effective decomposition and removal of organic halogenated compounds, a packed-bed non-thermal plasma reactor with in situ absorption of the resulting halogenated products by alkaline sorbent incorporated was proposed. In the plasma reactor, α-Al₂O₃ particles of 1 and 3 mm (mean particle diameter) were packed as solid dielectric medium to enhance the plasma power density in the reactor. Further, alkaline sorbent of Ca(OH)₂ was doped onto the surface of α-Al₂O₃ particles, in order to remove halogenated products by in situ absorption with Ca(OH)₂. A high-voltage and high-frequency pulsed power of −15 to 15 kV and 1 kHz was applied to the wire electrode of the plasma reactor by means of a DC power source. In the present study, as the sample of an organic halogenated compound that is most popularly used, we selected dichloromethane (CH₂Cl₂), and 500 ppm of the initial concentration of CH₂Cl₂ was fed into the reactor accompanied by air at a fixed flow rate of 500 × 10⁻⁶ m³ min⁻¹ at room temperature. As a result, it was recognized that the amount of CH₂Cl₂ decomposed by non-thermal plasma in an α-Al₂O₃ particle bed increased with an increase in plasma input power. The ratio of decomposition of CH₂Cl₂ was almost 100% at 13 kV of electric power and 1 kHz frequency, and CO₂, CH₃Cl, COCl₂, HCl, and Cl₂ were observed as the major reaction products. On the other hand, when CH₂Cl₂ was introduced into the plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ were packed, the ratio of decomposition of CH₂Cl₂ became higher, compared to the case that α-Al₂O₃ particles were not doped with Ca(OH)₂. Moreover, there were no halogenated by-product gases detected in the outlet gas from the reactor. As the solid reaction products, CaClOH and Ca(ClO)₂·4H₂O were detected on Ca(OH)₂ by X-ray diffraction. From these findings, it was recognized that CH₂Cl₂ was decomposed more effectively without producing unwanted harmful halogenated by-products in the proposed non-thermal plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ sorbent were packed.     

Baked Foams Based on Cassava Starch Coated with Polyvinyl Alcohol with a Higher Degree of Hydrolysis

The aims of this work were to produce trays based on cassava starch, coated with polyvinyl alcohol (PVA) with a higher degree of hydrolysis (98%), and to study the effects of the coating on the mechanical and water sorption properties of the trays. Two types of PVA were tested: SELVOL? 325 (degree of polymerization?=?1000–1500) and SELVOL? 107 (degree of polymerization?=?350–650). A decrease in the water absorption capacity of 50% was observed when the coated samples were compared with the control sample after 30 min of immersion in water. It was observed in both coated samples a reduction of the initial rate of water adsorption sorption and a decrease in hydrophilicity compared with the control sample. Tensile strength and elongation were increased with application of the coatings. The use of the two types of PVA resulted in materials with similar mechanical and water sorption properties.     

Overview of Contemporary Issues of Forest Research and Management in China

With 207 million ha of forest covering 22% of its land area, China ranks fifth in the world in forest area. Rapid economic growth, climate change, and forest disturbances pose new, complex challenges for forest research and management. Progress in meeting these challenges is relevant beyond China, because China’s forests represent 34% of Asia’s forests and 5% of the worlds’ forests. To provide a broader understanding of these management challenges and of research and policies that address them, we organized this special issue on contemporary forest research and management issues in China. At the national level, papers review major forest types and the evolution of sustainable forestry, the development of China’s forest-certification efforts, the establishment of a forest inventory system, and achievements and challenges in insect pest control in China. Papers focused on Northern China address historical, social, and political factors that have shaped the region’s forests; the use of forest landscape models to assess how forest management can achieve multiple objectives; and analysis and modeling of fuels and fire behavior. Papers addressing Central and South China describe the “Grain for Green” program, which converts low productivity cropland to grassland and woodland to address erosion and soil carbon sequestration; the potential effects of climate change on CO₂ efflux and soil respiration; and relationships between climate and net primary productivity. China shares many forest management and research issues with other countries, but in other cases China’s capacity to respond to forest management challenges is unique and bears watching by the rest of the world.