IMPLICATIONS OF A MARKET FOR CARBON ON TIMBER AND NON-TIMBER VALUES IN AN UNCERTAIN WORLD

Despite considerable interest in the potential for forests to sequester carbon, the impact of carbon management on the provision of timber and non-timber resources has received relatively little attention in the literature. The introduction of value for stored carbon may result in modifications to traditional forest management objectives, generating trade-offs with other forest resources depending on the incentives provided by carbon markets. This paper investigates these issues by examining the impact of a particular form of carbon market on timber and non-timber values in a managed forest. An integrated modeling framework, developed for the incorporation of carbon management into operational timber management modeling tools, is also described. There is still substantial debate over how to properly credit carbon sequestered in forests. To date, there has been little research on how the form of a carbon market will impact the operations and objectives of forestry firms. Alternative market structures could produce very different responses in terms of rotation age, net present value and harvest policy. Here, a specific form of carbon market, the specified level contract, is investigated. Forestry firms are assumed to reach contracts with carbon-seeking agents which "guarantee" that a specified level of carbon stock will be maintained over a defined time period. Optimal forest management decisions are examined by implementing an optimization model for a specific land base in Alberta. The Woodstock forest modeling package is used for optimization. Analysis of trade-offs is based on the work of Armstrong et al. (1999, 2003) which assess non-timber resources using the natural disturbance approach to forest management. The analysis is then expanded to include a more rigorous, and realistic, depiction of carbon and carbon stock changes. Using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3), carbon yield curves are developed which are integrated directly into the Woodstock forest management ii model. These carbon yields capture dynamics specific to separate biomass and dead organic matter (DOM) carbon pools and are represented for individual forest cover types. Interestingly, the inclusion of DOM carbon generates unexpected relationships between non-timber resources and incentives to sequester carbon. Results show that the presence of co-benefits will depend upon forest cover type, the harvest flow regulation faced by the managing firm and the incentives for timber supply provided by the market. Furthermore, firms that agree to enter contracts for carbon sequestration appear to do so at the expense of a decline in timber supply, with estimates of the opportunity cost of carbon management falling within the range of those found in recent literature.Resource /Energy Economics and Policy,

Non-Born-Oppenheimer calculations of the lowest vibrational energy of HD including relativistic corrections

In this work we report variational calculations of the two lowest vibrational states of the HD molecule within the framework that does not assume the Born-Oppenheimer BO approximation. The nonrelativistic energies of the states were corrected for the relativistic effects of the order of 2 where = 1 c , calculated as expectation values of the operators representing these effects with the nonrelativistic non-BO wave functions. The non-BO wave functions were expanded in terms of the one-center explicitly correlated Gaussian functions multiplied by even powers of the internuclear distance. The v=0→1 transition energy obtained in the calculations is compared with the previous calculations, as well as with the transition frequency obtained from the experimental spectra. The comparison shows the need to include corrections higher than second order in to further improve the agreement between the theory and the experimen

Urethral management after artificial urinary sphincter explantation due to cuff erosion

Introduction: The artificial urethral sphincter (AUS) is the gold standard treatment in cases of moderate-to-severe stress urinary incontinence in males. Cuff erosions are one of the most important distant complications of AUS implantation. The optimal urethral management has still not been established. Material and methods: Search terms related to 'urethral stricture', 'artificial urinary sphincter', and 'cuff erosion' were used in the PubMed database to identify relevant articles. Results: In this mini review we identified 6 original articles that assessed the urethral management after AUS explantation due to cuff erosion and included urinary diversion by transurethral and/or suprapubic catheterization, urethrorrhaphy, and in situ urethroplasty. We summarized the results of different management methods and their efficacy in terms of preventing urethral stricture formation. We highlight the need for better-quality evidence on this topic. Conclusions: The available data do not provide a clear answer to the question of optimal urethral management during AUS explantation. There is a great need to provide higher-quality evidence on this topic

Measuring price elasticities of demand and supply of water entitlements based on stated and revealed preference data

Estimates of price elasticities of water entitlements, known as permanent water or water rights in the United States, are complicated by data limitations and problems of endogeneity. To overcome these issues, we develop an approach to generate stated preference data and combine them with revealed preference data to estimate price elasticities from various types of water entitlement sales in the southern Murray-Darling Basin, Australia. Our results suggest that price elasticities of demand and supply of high security water entitlements are inelastic in the relevant market price range between AUD $1,700 to$2,100 per mega-liter, and that supply is relatively more inelastic than demand. For lower reliability water entitlements, the price elasticity of demand is estimated to be even more inelastic than high security water entitlements. The price elasticity of supply for general security water entitlements is similar to high security water entitlements, while the supply of low reliability water entitlements is extremely inelastic for our data set. The comparison between the stated and revealed preference data provides strong evidence of support for a data fusion approach, nevertheless, some differences in water sale preferences were found for irrigators choosing not to sell all of their water. The consistency of our results signals support for the use of this methodology in other water basins around the world.Alec Zuo, Sarah Ann Wheeler, W.L. (Vic) Adamowicz, Peter C. Boxall and Darla Hatton-MacDonal

Sustainable Forest Management Preferences of Interest Groups in Three Regions with Different Levels of Industrial Forestry: An Exploratory Attribute-Based Choice Experiment

The challenge of sustainable forest management is to integrate diverse and sometimes conflicting management objectives. In order to achieve this goal, we need a better understanding of the aspects influencing the preferences of diverse groups and how these groups make trade-offs between different attributes of SFM. We compare the SFM preferences of interest groups in regions with different forest use histories based on the reasoning that the condition of the forest reflects the forest use history of the area. The condition of the forest also shapes an individual’s forest values and attitudes. These held values and attitudes are thought to influence SFM preferences. We tested whether the SFM preferences vary amongst the different interest groups within and across regions. We collected data from 252 persons using a choice experiment approach, where participants chose multiple times among different options described by a combination of attributes that are assigned different levels. The novelty of our approach was the use of choice experiments in the assessment of regional preference differences. Given the complexity of interregional comparison and the small sample size, this was an exploratory study based on a purposive rather than random sample. Nevertheless, our results suggest that the aggregation of preferences of all individuals within a region does not reveal all information necessary for forest management planning since opposing viewpoints could cancel each other out and lead to an interpretation that does not reflect possibly polarised views. Although based on a small\ud sample size, the preferences of interest groups within a region are generally statistically significantly different from each other; however preferences of interest groups across regions are also significantly different. This illustrates the potential importance of assessing heterogeneity by region and by group

Ultrasound imaging of male urethral stricture disease: a narrative review of the available evidence, focusing on selected prospective studies

Purpose: To synthetize the current scientific knowledge on the use of ultrasound of the male urethra for evaluation of urethral stricture disease. This review aims to provide a detailed description of the technical aspects of ultrasonography, and provides some indications on clinical applications of it, based on the evidence available from the selected prospective studies. Advantages and limitations of the technique are also provided. Methods: A comprehensive literature search was performed using the Medline and Cochrane databases on October 2022. The articles were searched using the keywords "sonourethrography", "urethral ultrasound", "urethral stricture" and "SUG". Only human studies and articles in English were included. Articles were screened by two reviewers (M.F. and K.M.). Results: Our literature search reporting on the role of sonourethrography in evaluating urethral strictures resulted in selection of 17 studies, all prospective, even if of limited quality due to the small patients' number (varied from 28 to 113). Nine studies included patients with urethral stricture located in anterior urethra and eight studies included patients regardless of the stricture location. Final analysis was based on selected prospective studies, whose power was limited by the small patients' groups. Conclusion: Sonourethrography is a cost-effective and safe technique allowing for a dynamic and three-dimensional urethra assessment. Yet, because of its limited value in detecting posterior urethral strictures, the standard urethrography should remain the basic 'road-map' prior to surgery. It is an operator-dependent technique, which can provide detailed information on the length, location, and extent of spongiofibrosis without risks of exposure to ionizing radiation.Open Access funding enabled and organized by Projekt DEAL

Quantum Monte Carlo calculations of the one-body density matrix and excitation energies of silicon

Quantum Monte Carlo (QMC) techniques are used to calculate the one-body density matrix and excitation energies for the valence electrons of bulk silicon. The one-body density matrix and energies are obtained from a Slater-Jastrow wave function with a determinant of local density approximation (LDA) orbitals. The QMC density matrix evaluated in a basis of LDA orbitals is strongly diagonally dominant. The natural orbitals obtained by diagonalizing the QMC density matrix resemble the LDA orbitals very closely. Replacing the determinant of LDA orbitals in the wave function by a determinant of natural orbitals makes no significant difference to the quality of the wave function's nodal surface, leaving the diffusion Monte Carlo energy unchanged. The Extended Koopmans' Theorem for correlated wave functions is used to calculate excitation energies for silicon, which are in reasonable agreement with the available experimental data. A diagonal approximation to the theorem, evaluated in the basis of LDA orbitals, works quite well for both the quasihole and quasielectron states. We have found that this approximation has an advantageous scaling with system size, allowing more efficient studies of larger systems.Comment: 13 pages, 4 figures. To appear in Phys. Rev.

Riemann-Cartan Space-times of G\"odel Type

A class of Riemann-Cartan G\"odel-type space-times are examined in the light of the equivalence problem techniques. The conditions for local space-time homogeneity are derived, generalizing previous works on Riemannian G\"odel-type space-times. The equivalence of Riemann-Cartan G\"odel-type space-times of this class is studied. It is shown that they admit a five-dimensional group of affine-isometries and are characterized by three essential parameters $\ell, m^2, \omega$: identical triads ($\ell, m^2, \omega$) correspond to locally equivalent manifolds. The algebraic types of the irreducible parts of the curvature and torsion tensors are also presented.Comment: 24 pages, LaTeX fil

Preferences and skills of Indian public sector teachers

With a sample of 700 future public sector primary teachers in India, a Discrete Choice Experiment is used to measure job preferences, particularly regarding location. General skills are also tested. Urban origin teachers and women are more averse to remote locations than rural origin teachers and men respectively. Women would require a 26-73 percent increase in salary for moving to a remote location. The results suggest that existing caste and gender quotas can be detrimental for hiring skilled teachers willing to work in remote locations. The most preferred location is home, which supports decentralised hiring, although this could compromise skills