Lumber Futures and Timberland Investment

Using 20 years of data, we derive a pricing model for timberland market values. We examine the relationship between lumber futures, capitalization rates, anticipated inflation, anticipated construction and timberland value. Using an ordinary least squares regression model and Johansen’s cointegration technique, we find that timberland market values have a long-run significant positive equilibrium relationship with lumber futures, and building permits. Capitalization rates have a significant negative relationship as expected. In the short run, unanticipated shocks in the independent variables provide a permanent change in timberland market values.

Nuclear Magnetic Resonance Quantum Computing Using Liquid Crystal Solvents

Liquid crystals offer several advantages as solvents for molecules used for nuclear magnetic resonance quantum computing (NMRQC). The dipolar coupling between nuclear spins manifest in the NMR spectra of molecules oriented by a liquid crystal permits a significant increase in clock frequency, while short spin-lattice relaxation times permit fast recycling of algorithms, and save time in calibration and signal-enhancement experiments. Furthermore, the use of liquid crystal solvents offers scalability in the form of an expanded library of spin-bearing molecules suitable for NMRQC. These ideas are demonstrated with the successful execution of a 2-qubit Grover search using a molecule ($^{13}$C$^{1}$HCl$_3$) oriented in a liquid crystal and a clock speed eight times greater than in an isotropic solvent. Perhaps more importantly, five times as many logic operations can be executed within the coherence time using the liquid crystal solvent.Comment: Minor changes. Published in Appl. Phys. Lett. v.75, no.22, 29 Nov 1999, p.3563-356

Balancing Design Options with Sherpa

Application specific processors offer the potential of rapidly designed logic specifically constructed to meet the performance and area demands of the task at hand. Recently, there have been several major projects that attempt to automate the process of transforming a predetermined processor configuration into a low level description for fabrication. These projects either leave the specification of the processor to the designer, which can be a significant engineering burden, or handle it in a fully automated fashion, which completely removes the designer from the loop. In this paper we introduce a technique for guiding the design and optimization of application specific processors. The goal of the Sherpa design framework is to automate certain design tasks and provide early feedback to help the designer navigate their way through the architecture design space. Our approach is to decompose the overall problem of choosing an optimal architecture into a set of sub-problems that are, to the first order, independent. For each subproblem, we create a model that relates performance to area. From this, we build a constraint system that can be solved using integer-linear programming techniques, and arrive at an ideal parameter selection for all architectural components. Our approach only takes a few minutes to explore the design space allowing the designer or compiler to see the potential benefits of optimizations rapidly. We show that the expected performance using our model correlates strongly to detailed pipeline simulations, and present results showing design tradeoffs for several different benchmarks

Non-thermal nuclear magnetic resonance quantum computing using hyperpolarized Xenon

Current experiments in liquid-state nuclear magnetic resonance quantum computing are limited by low initial polarization. To address this problem, we have investigated the use of optical pumping techniques to enhance the polarization of a 2-qubit NMR quantum computer (13C and 1H in 13CHCl3). To efficiently use the increased polarization, we have generalized the procedure for effective pure state preparation. With this new, more flexible scheme, an effective pure state was prepared with polarization-enhancement of a factor of 10 compared to the thermal state. An implementation of Grover's quantum search algorithm was demonstrated using this new technique.Comment: 4 pages, 3 figures. Submitted for publicatio

Implementation of a three-quantum-bit search algorithm

We report the experimental implementation of Grover's quantum search algorithm on a quantum computer with three quantum bits. The computer consists of molecules of $^{13}$C-labeled CHFBr$_2$, in which the three weakly coupled spin-1/2 nuclei behave as the bits and are initialized, manipulated, and read out using magnetic resonance techniques. This quantum computation is made possible by the introduction of two techniques which significantly reduce the complexity of the experiment and by the surprising degree of cancellation of systematic errors which have previously limited the total possible number of quantum gates.Comment: Published in Applied Physics Letters, vol. 76, no. 5, 31 January 2000, p.646-648, after minor revisions. (revtex, mypsfig2.sty, 3 figures

Supporting the implementation of guidelines to prevent mother-to-child-transmission of HIV in Malawi: a multi-case study

BackgroundHigh HIV infection and fertility rates contributed to over 12,000 children acquiring HIV from their mothers in 2011 in Malawi. To prevent mother-to-child transmission of HIV, Malawi adopted the Option B+ guidelines, and for three years, the University of North Carolina (UNC) Project provided support to strengthen guideline implementation in 134 health centres. Little is known about how implementation support strategies are delivered in low resource countries or contextual factors that may influence their delivery. The limited descriptions of support strategies and salient contextual factors limits efforts to replicate, target, and further refine strategies. Guided by the Interactive Systems Framework for Dissemination and Implementation, this study describes factors influencing implementation of support strategies and how they impacted health center staff capacity to implement Option B+ in Malawi. MethodsA qualitative multi-case study design was applied. Data were collected through site visits to 4 heath centres (2 low- and 2-high performing centres). We interviewed 18 support providers and recipients between October 2014 and October 2015. Data were analysed using content, thematic, and cross-case analysis.ResultsFour categories of strategies were used to support Option B+ guidelines implementation: training, technical assistance (TA), tools, and resources. All heath-centres implemented Option B+ guidelines for care provided between the antenatal and labor and delivery periods. Gaps in Option B+ implementation occurred during community activities and during post-delivery care, including gaps in testing of children to ascertain their HIV status at 6 weeks, 12 months, and 24 months. Salient contextual factors included staffing shortages, transportation challenges, limited space and infrastructure, limited stocks of HIV testing kits, and large patient populations.ConclusionsUnderstanding factors that influence implementation support strategies and delivery of the Option B+ guidelines, such as availability of staff and other materials/drug resources, is critical to designing effective implementation support for low resource settings

Electronic Selection Rules Controlling Dislocation Glide in bcc Metals

The validity of the structure-property relationships governing the deformation behavior of bcc metals was brought into question with recent {\it ab initio} density functional studies of isolated screw dislocations in Mo and Ta. These existing relationships were semiclassical in nature, having grown from atomistic investigations of the deformation properties of the groups V and VI transition metals. We find that the correct form for these structure-property relationships is fully quantum mechanical, involving the coupling of electronic states with the strain field at the core of long $a/2$ screw dislocations.Comment: 4 pages, 2 figure

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide