Application to U.S. Atomic Energy Commission for reactor construction permit and operating license.

The plant is to be located at Big Rock Point, Charlevoix County, on Lake Michigan between the towns of Charlevoix and Petoskey.

Adventitious root formation in cuttings of Backhousia citriodora F. Muell: 1. Plant genotype, juvenility and characteristics of cuttings

Backhousia citriodora is a commercially valuable Australian woody species that has a reputation for being recalcitrant in forming adventitious roots from cuttings. A study was carried out to determine whether maturation and plant genotype influenced rooting. It also tried to establish whether genotypic differences in rooting ability were related to characteristics of the cutting material. The rooting of cuttings in B. citriodora declines after maturation and is strongly influenced by genotype. The cutting characteristics of actively growing axillary buds, wide stems and mature leaves are associated with rooting and survival but not related to genotype. Furthermore, the 8-24 weeks required by B. citriodora to form roots from cuttings makes it difficult to distinguish between the characteristics that increase rooting and those characteristics that enhance survival. A subsequent disbudding experiment demonstrated that axillary buds per se have an inhibitory effect on rooting. This suggests that the presence of actively growing axillary buds are an indication of overall growth and condition of the stock plant unrelated to the formation of adventitious rooting. The effects of other cutting characteristics on rooting are also discussed. (C) 2004 Elsevier B.V. All rights reserved.

Using the floatability characterisation test rig for industrial flotation plant design

Industrial flotation plant design is a complex process involving many aspects, one of which is the use of pilot-scale plants to test industrial plant flow sheets. Once test work on a pilot-scale has been performed, scale-up of these results to the full-scale plant must be performed. This paper describes scale-up test work performed on the Floatability Characterisation Test Rig (FCTR). The FCTR is a self-contained, highly instrumented mobile pilot plant designed to determine flotation model parameters and to develop and validate flotation plant modelling, scale-up and simulation methodologies.

The effect of salinity on plant available water

Salinity acts to inhibit plant access to soil water by increasing the osmotic strength of the soil solution. As the soil dries, the soil solution becomes increasingly concentrated, further limiting plant access to soil water. An experiment was conducted to examine the effect of salt on plant available water in a heavy clay soil, using a relatively salt tolerant species, wheat ‘Kennedy’, and a more salt sensitive species, chickpea ‘Jimbour’. Sodium chloride was applied to Red Ferrosol at 10 rates from 0 to 3 g/kg. Plants were initially maintained at field capacity. After 3 weeks, plants had become established and watering was ceased. The plants then grew using the water stored in the soil. Once permanent wilting point was reached plants were harvested, and soil water content was measured. The results showed that without salt stress, wheat and chickpea extracted approximately the same amount of water. However, as the salt concentration increased, the ability of chickpea to extract water was severely impaired, while wheat’s ability to extract water was not affected over the range of concentrations examined. Growth of both wheat and chickpea was reduced even from low salt concentrations. Possible explanations for this are that the effect on growth is due to Cl- toxicity and that this occurs at lower concentrations than the osmotic effect of salinity, or that the metabolic demands of maintaining plant water balance and extracting soil water under saline conditions result in reduced growth.

Simulating spray deposition on plant canopies within a wind tunnel

Three-dimensional computer modelling techniques are being used to develop a probabilistic model of turbulence-related spray transport around various plant architectures to investigate the influence of plant architectures and crop geometry on the sprayapplication process. Plant architecture models that utilise a set of growth rules expressed in the Lindenmayer systems (L-systems) formalism have been developed and programmed using L-studio software. Modules have been added to simulate the movement ofdroplets through the air and deposition on the plant canopy. Deposition of spray on an artificial plant structure was measured in the wind tunnel at the University of Queensland, Gatton campus and the results compared to the model simulation. Further trials are planned to measure the deposition of spray droplets on various crop and weed species and the results from these trials will be used to refine and validate the combined spray and plant architecture model.

Can the Paks-2 Nuclear Power Plant operate without State aid? A business economic analysis

Many studies have investigated the prospects for returns, the budgetary and financing background and energy management effects of the new nuclear power plant units to be built at Paks. This document seeks to complement previous economics-based studies by adding a new criterion. The key question in our analysis is whether the power plant company will be capable of independent operations in an economic sense - or will its survival depend on further additional aid by the owner, i.e. via the central budget, after its commissioning? We shall examine from a corporate perspective in what ways the already disclosed financing terms and conditions may affect the everyday operations of the power plant company.

Ecosystem responses to hydrologic change and mechanisms of nitrogen sequestration in seasonally flooded tree islands of the southern Everglades

In the Florida Everglades, tree islands are conspicuous heterogeneous elements in a complex wetland landscape. I investigated the effects of increased freshwater flow in southern Everglades seasonally flooded tree islands, and characterized biogeochemical interactions among tree islands and the marsh landscape matrix, specifically examining hydrologic flows of nitrogen (N), and landscape N sequestration capacity. I utilized ecological trajectories of key ecosystem variables to differentiate effects of increased sheetflow and hydroperiod. I utilized stable isotope analyses and nutrient content of tree island ecosystem components to test the hypothesis that key processes in tree island nitrogen cycling would favor ecosystem N sequestration. I combined estimates of tree island ecosystem N standing stocks and fluxes, soil and litter N transformation rates, and hydrologic inputs of N to quantify the net sequestration of N by a seasonally flooded tree island. ^ Results show that increased freshwater flow to seasonally flooded tree islands promoted ecosystem oligotrophy, whereas reduced flows allowed some plant species to cycle P less efficiently. As oligotrophy is a defining parameter of Everglades wetlands, and likely promotes belowground production and peat development, reintroducing freshwater flow from an upstream canal had a favorable effect on ecosystem dynamics of tree islands in the study area. Important factors influencing the stable isotopic composition of nitrogen and carbon were: (1) a contribution to soil N by soil invertebrates, animal excrement, and microbes, (2) a possible NO3 source from an upstream canal and an "open" ecosystem N cycle, and (3) greater availability of phosphorus in tree islands relative to the marsh landscape, suggesting that tree island N cycling favors N sequestration. Hydrologic sources of N were dominated by surface water loads of NO3- and NH 4+, and an important soil N transformation promoting the net loss of surface water DIN was nitrate immobilization associated with soils and surficial leaf litter. The net inorganic N sequestration capacity of a seasonally flooded tree island was 50 g yr-1 m -2. Thus, tree islands likely have an important function in landscape sequestration of inorganic N, and may reduce significant anthropogenic N loads to downstream coastal systems. ^

The contribution of leaching to the rapid release of nutrients and carbon in the early decay of wetland vegetation

Our goal was to quantify the coupled process of litter turnover and leaching as a source of nutrients and fixed carbon in oligotrophic, nutrient-limited wetlands. We conducted poisoned and non-poisoned incubations of leaf material from four different perennial wetland plants (Eleocharis spp., Cladium jamaicense, Rhizophora mangle and Spartina alterniflora) collected from different oligotrophic freshwater and estuarine wetland settings. Total phosphorus (TP) release from the P-limited Everglades plant species (Eleocharis spp., C. jamaicense and R. mangle) was much lower than TP release by the salt marsh plant S. alterniflora from N-limited North Inlet (SC). For most species and sampling times, total organic carbon (TOC) and TP leaching losses were much greater in poisoned than non-poisoned treatments, likely as a result of epiphytic microbial activity. Therefore, a substantial portion of the C and P leached from these wetland plant species was bio-available to microbial communities. Even the microbes associated with S. alterniflora from N-limited North Inlet showed indications of P-limitation early in the leaching process, as P was removed from the water column. Leaves of R. mangle released much more TOC per gram of litter than the other species, likely contributing to the greater waterborne [DOC] observed by others in the mangrove ecotone of Everglades National Park. Between the two freshwater Everglades plants, C. jamaicense leached nearly twice as much P than Eleocharis spp. In scaling this to the landscape level, our observed leaching losses combined with higher litter production of C. jamaicense compared to Eleocharis spp. resulted in a substantially greater P leaching from plant litter to the water column and epiphytic microbes. In conclusion, leaching of fresh plant litter can be an important autochthonous source of nutrients in freshwater and estuarine wetland ecosystems.

Effect of leaf-cutting ant nests on plant growth in an oligotrophic Amazon rain forest

This study examined whether high nutrient concentrations associated with leaf-cutting ant nests influence plant growth and plant water relations in Amazon rain forests. Three nests of Atta cephalotes were selected along with 31 Amaioua guianensis and Protium sp. trees that were grouped into trees near and distant (>10 m) from nests. A 15N leaf-labelling experiment confirmed that trees located near nests accessed nutrients from nests. Trees near nests exhibited higher relative growth rates (based on stem diameter increases) on average compared with trees further away; however this was significant for A. guianensis (near nest 0.224 y−1 and far from nest 0.036 y−1) but not so for Protium sp. (0.146 y−1 and 0.114 y−1 respectively). Water relations were similarly species-specific; for A. guianensis, near-nest individuals showed significantly higher sap flow rates (16 vs. 5 cm h−1), higher predawn/midday water potentials (−0.66 vs. −0.98 MPa) and lower foliar δ13C than trees further away indicating greater water uptake in proximity to the nests while the Protium sp. showed no significant difference except for carbon isotopes. This study thus shows that plant response to high nutrient concentrations in an oligotrophic ecosystem varies with species. Lower seedling abundance and species richness on nests as compared with further away suggests that while adult plants access subterranean nutrient pools, the nest surfaces themselves do not encourage plant establishment and growth.

Conjugated polymer nanoparticles for effective siRNA delivery to tobacco BY-2 protoplasts

Background Post transcriptional gene silencing (PTGS) is a mechanism harnessed by plant biologists to knock down gene expression. siRNAs contribute to PTGS that are synthesized from mRNAs or viral RNAs and function to guide cellular endoribonucleases to target mRNAs for degradation. Plant biologists have employed electroporation to deliver artificial siRNAs to plant protoplasts to study gene expression mechanisms at the single cell level. One drawback of electroporation is the extensive loss of viable protoplasts that occurs as a result of the transfection technology. Results We employed fluorescent conjugated polymer nanoparticles (CPNs) to deliver siRNAs and knockdown a target gene in plant protoplasts. CPNs are non toxic to protoplasts, having little impact on viability over a 72 h period. Microscopy and flow cytometry reveal that CPNs can penetrate protoplasts within 2 h of delivery. Cellular uptake of CPNs/siRNA complexes were easily monitored using epifluorescence microscopy. We also demonstrate that CPNs can deliver siRNAs targeting specific genes in the cellulose biosynthesis pathway (NtCesA-1a and NtCesA-1b). Conclusions While prior work showed that NtCesA-1 is a factor involved in cell wall synthesis in whole plants, we demonstrate that the same gene plays an essential role in cell wall regeneration in isolated protoplasts. Cell wall biosynthesis is central to cell elongation, plant growth and development. The experiments presented here shows that NtCesA is also a factor in cell viability. We show that CPNs are valuable vehicles for delivering siRNAs to plant protoplasts to study vital cellular pathways at the single cell level.

Pollen records from Bol'shoy Lyakhovsky Island, Siberia

Cryolithological, ground ice and fossil bioindicator (pollen, diatoms, plant macrofossils, rhizopods, insects, mammal bones) records from Bol'shoy Lyakhovsky Island permafrost sequences (73°20'N, 141°30'E) document the environmental history in the region for the past c. 115 kyr. Vegetation similar to modern subarctic tundra communities prevailed during the Eemian/Early Weichselian transition with a climate warmer than the present. Sparse tundra-like vegetation and harsher climate conditions were predominant during the Early Weichselian. The Middle Weichselian deposits contain peat and peaty soil horizons with bioindicators documenting climate amelioration. Although dwarf willows grew in more protected places, tundra and steppe vegetation prevailed. Climate conditions became colder and drier c. 30 kyr BP. No sediments dated between c. 28.5 and 12.05 14C kyr BP were found, which may reflect active erosion during that time. Herb and shrubby vegetation were predominant 11.6-11.3 14C kyr BP. Summer temperatures were c. 4 °C higher than today. Typical arctic environments prevailed around 10.5 14C kyr BP. Shrub alder and dwarf birch tundra were predominant between c. 9 and 7.6 kyr BP. Reconstructed summer temperatures were at least 4 °C higher than present. However, insect remains reflect that steppe-like habitats existed until c. 8 kyr BP. After 7.6 kyr BP, shrubs gradually disappeared and the vegetation cover became similar to that of modern tundra. Pollen and beetles indicate a severe arctic environment c. 3.7 kyr BP. However, Betula nana, absent on the island today, was still present. Together with our previous study on Bol'shoy Lyakhovsky Island covering the period between about 200 and 115 kyr, a comprehensive terrestrial palaeoenvironmental data set from this area in western Beringia is now available for the past two glacial-interglacial cycles.

Overview on bio-based building material made with plant aggregate

Global warming, energy savings, and life cycle analysis issues are factors that have contributed to the rapid expansion of plant-based materials for buildings, which can be qualified as environmental-friendly, sustainable and efficient multifunctional materials. This review presents an overview on the several possibilities developed worldwide about the use of plant aggregate to design bio-based building materials. The use of crushed vegetal aggregates such as hemp (shiv), flax, coconut shells and other plants associated to mineral binder represents the most popular solution adopted in the beginning of this revolution in building materials. Vegetal aggregates are generally highly porous with a low apparent density and a complex architecture marked by a multi-scale porosity. These geometrical characteristics result in a high capacity to absorb sounds and have hygro-thermal transfer ability. This is one of the essential characteristics which differ of vegetal concrete compared to the tradition mineral-based concretes. In addition, the high flexibility of the aggregates leads to a non-fragile elasto-plastic behavior and a high deformability under stress, lack of fracturing and marked ductility with absorbance of the strains ever after having reached the maximum mechanical strength. Due to the sensitivity to moisture, the assessment of the durability of vegetal concrete constitutes one of the next scientific challenging of bio-based building materials.

Bat-plant pollination interactions in southern Thailand

The overwhelming majority of flowering plant species depend on animals for pollination, and such pollinators are important for the reproductive success of many economically and environmentally important plant species. Yet pollinators in the Old World tropics are relatively understudied, particularly paleotropical nectarivorous bats (Pteropodidae), and much is unknown about their interactions with night-blooming plant species. To better understand these bat-plant pollination interactions, I conducted fieldwork in southern Thailand for a total of 20 months, spread across three years. I examined the foraging times of pteropodid bat species (Chapter 1), and found that strictly nectarivorous species foraged earlier, and for a shorter duration, than primarily frugivorous species. I also studied year-long foraging patterns of pteropodid bats to determine how different species track floral resources across seasons (Chapter 2). Larger species capable of flying long distances switched diets seasonally to forage on the most abundant floral species, while smaller species foraged throughout the year on nearby plant species that were low-rewarding but highly reliable. To determine which pteropodid species are potentially important pollinators, I quantified the frequency and effectiveness of their visits to six common bat-pollinated plant taxa for an entire year (Chapter 3). The three strictly nectarivorous species were responsible for almost all pollination, but pollinator importance of each bat species varied across plant species. I further examined the long-term reliability of these pollinators (Chapter 4), and found that pollinator importance values were consistent across the three study years. Lastly, I explored mechanisms that reduce interspecific pollen transfer among bat-pollinated plants, despite having shared pollinators. Using a flight cage experiment, I demonstrated that these plant species deposit pollen on different areas of the bat’s body (mechanical partitioning), resulting in greater pollen transfer between conspecific flowers than heterospecific flowers (Chapter 5). Additionally, while I observed ecological and phenological overlap among flowering plant species, pollinators exhibited high floral constancy within a night, resulting in strong ethological separation (Chapter 6). Collectively, these findings illustrate the importance of understudied Old World bat pollinators within a mixed agricultural-forest system, and their strong, interdependent interactions with bat-pollinated plant species within a night, across seasons, and across years.

Estimating production costs and profitability of strawberry genotypes in southeast Queensland using plant traits

In Queensland the subtropical strawberry (Fragaria ×ananassa) breeding program aims to combine traits into new genotypes that increase production efficiency. The contribution of individual plant traits to cost and income under subtropical Queensland conditions has been investigated. The study adapted knowledge of traits and the production and marketing system to assess the economic impact (gross margin) of new cultivars on the system, with the overall goal of improving the profitability of the industry through the release of new strawberry cultivars. Genotypes varied widely in their effect on gross margin, from 48% above to 10% below the base value. The advantage of a new genotype was also affected by the proportion of total area allocated to the new genotype. The largest difference in gross margin between that at optimum allocation (8% increase in gross margin) and an all of industry allocation (20% decrease in gross margin) of area to the genotype was 28%. While in other cases the all of industry allocation was also the optimum allocation, with one genotype giving a 48% benefit in gross margin.

Farm practices to manage the impact of severe tropical cyclone damage on banana production – a case study from tropical Australia

Most Australian banana production occurs on the north-eastern tropical coast between latitudes 15-18°S, and can experience summer cyclone activity. Damage from severe tropical cyclones has serious impact on banana-based livelihoods. The most significant impacts include immediate loss of production and income for several months, the region-wide synchronization of cropping and the expense of rehabilitating affected plantations. Severe tropical cyclones have directly affected the main production region twice in recent years Tropical Cyclone (TC) Larry (Category 4) in March 2006 and TC Yasi (Category 5) in February 2011. Based on TC Larry experiences, pre- and post-cyclone farm practices were developed to reduce these impacts in future cyclonic events. The main pre-cyclone farm practice focused on maintaining production units and an earlier return to fruit production by partially or completely removing the plant canopy to reduce wind resistance. Post-cyclone farm practices focused on managing the industry-wide crop synchronization using crop timing techniques to achieve a staggered return to cropping by scheduling production to provide continuous fruit supply. With TC Yasi in 2011, some banana producers implemented these practices, allowing them to examine their effectiveness in reducing cyclonic impacts. Additional research and development activities were conducted to refine our understanding of their effectiveness and improve their application for future cyclonic events. Based on these activities and farm-based observations, suggested practice-based management strategies can be developed to help reduce the impact of severe tropical cyclones in the future. Canopy removal maintained banana plants as productive units, and provided earlier but smaller bunches, generating earlier-than-expected income. Queensland producers expressed willingness to adopt canopy removal for future cyclone threats where appropriate, despite its labor-intensiveness. Mechanization would allow larger scale adoption. Implementing a staggered cropping program successfully achieved a consistent, continuous fruit supply after a cyclone impact. Both techniques should be applicable to other cyclone-prone regions.