Sustainable Forest Management, Forest Certification, Tree Improvement, and Forest Biotechnology

Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Impact of new technology on timber harvesting costs: Evaluation methods and literature

Timber harvesting and transport are crucial components of the cost of delivered wood to forest products processing facilities. In fact, harvesting and delivering wood often costs more than the entire costs of growing wood until harvest. As such, timber harvesting research and development are important. Additionally, research in this area is worthwhile because efficiency gains, cost improvements, and environmental benefits due to timber harvesting research can be realized in a very short time period, rather than the decades-long wait required for research investments in timber growing. This paper provides an overview of the means of measuring the impact of new technology on timber harvesting costs. In recent years, there have been many efforts to increase research for developing better harvesting equipment and methods. In conjunction with these efforts, greater demands have been made for research efficiency and accountability (Silversides et al. 1988); several studies have therefore been completed to measure the impacts of timber harvesting research and development. These studies, other means of evaluating timber harvesting research, and suggestions for future evaluations are discussed

Space applications of superconducting microwave electronics at NASA Lewis Research Center

Since the discovery of high temperature superconductivity in 1987, NASA Lewis Research Center has been involved in efforts to demonstrate its advantages for applications involving microwave electronics in space, especially space communications. The program included thin film fabrication by means of laser ablation. Specific circuitry which was investigated includes microstrip ring resonators at 32 GHz, phase shifters which utilize a superconducting, optically activated switch, an 8x8 32 GHz superconducting microstrip antenna array, and an HTS-ring-resonator stabilized oscillator at 8 GHz. The latter two components are candidates for use in space experiments which are described in other papers. Experimental data on most of the circuits are presented as well as, in some cases, a comparison of their performance with an identical circuit utilizing gold or copper metallization

Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation

Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF) and canonical Wingless-type MMTV integration site (Wnt/β-Catenin) signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx). We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation

The photochemistry of N-p-toluenesulfonyl peptides: the peptide bond as an electron donor

The scope of photobiological processes that involve absorbers within a protein matrix may be limited by the vulnerability of the peptide group to attack by highly reactive redox centers consequent upon electronic excitation. We have explored the nature of this vulnerability by undertaking comprehensive product analyses of aqueous photolysates of 12 N-p-toluene-sulfonyl peptides with systematically selected structures. The results indicate that degradation includes a major pathway that is initiated by intramolecular electron transfer in which the peptide bond serves as electron donor, and the data support the likelihood of a relay process in dipeptide derivatives

AHR2 Mutant Reveals Functional Diversity of Aryl Hydrocarbon Receptors in Zebrafish

The aryl hydrocarbon receptor (AHR) is well known for mediating the toxic effects of TCDD and has been a subject of intense research for over 30 years. Current investigations continue to uncover its endogenous and regulatory roles in a wide variety of cellular and molecular signaling processes. A zebrafish line with a mutation in ahr2 (ahr2hu3335), encoding the AHR paralogue responsible for mediating TCDD toxicity in zebrafish, was developed via Targeting Induced Local Lesions IN Genomes (TILLING) and predicted to express a non-functional AHR2 protein. We characterized AHR activity in the mutant line using TCDD and leflunomide as toxicological probes to investigate function, ligand binding and CYP1A induction patterns of paralogues AHR2, AHR1A and AHR1B. By evaluating TCDD-induced developmental toxicity, mRNA expression changes and CYP1A protein in the AHR2 mutant line, we determined that ahr2hu3335 zebrafish are functionally null. In silico modeling predicted differential binding of TCDD and leflunomide to the AHR paralogues. AHR1A is considered a non-functional pseudogene as it does not bind TCCD or mediate in vivo TCDD toxicity. Homology modeling, however, predicted a ligand binding conformation of AHR1A with leflunomide. AHR1A-dependent CYP1A immunohistochemical expression in the liver provided in vivo confirmation of the in silico docking studies. The ahr2hu3335 functional knockout line expands the experimental power of zebrafish to unravel the role of the AHR during development, as well as highlights potential activity of the other AHR paralogues in ligand-specific toxicological responses

Projecting Global and Regional Forest Area under the Shared Socioeconomic Pathways Using an Updated Environmental Kuznets Curve Model

Forest resources are critical to environmental, economic, and social development, and there is substantial interest in understanding how global forest area will evolve in the future. Using an Environmental Kuznets Curve (EKC) model of total forest area that we updated using more recent data sets, we projected forest area through 2100 in 168 countries using variables including income, rural population density, and the size of the labor force under different world visions drawn from alternative Intergovernmental Panel on Climate Change socioeconomic pathways (SSPs). Results provided support for the existence of an EKC for total forest area, with rural population density negatively affecting forest area and labor force size positively affecting forest area. The projections showed modest and continuous increases in global forest area in all the SSPs, but varying trends for major world regions, which is consistent with the projected trends from the explanatory variables in each country. Aggregate global forest area is projected to increase by 7% as of 2100 relative to 2015 levels in SSP3, which predicts a future with the lowest rate of economic growth, and by 36% in SSP5, which is a future with the highest rate of economic growth and greater economic equality across countries. The results show how projections driven only by income produce biased results compared to the projections made with an EKC that includes rural population density and labor force variables.Peer reviewe