What Price for the Right to Go a-Droving? A Derived Demand Approach

Travelling stock reserves (TSRs) were established in Australia as a way of allowing the passage of livestock through settled lands to facilitate stocking of new lands. Subsequently, they remained important as a way of moving livestock from property to property or from property to market. Today, the area of land dedicated to TSRs in NSW is estimated at 2.3 million hectares, which are used more as a source of feed than as a livestock thoroughfare. The value of TSRs as a source of feed is particularly important during drought periods, and pricing of access for walking stock has become a subject of contention within the Rural Land Protection Boards (RLPB). The price of TSR permits for walking stock is considerably lower than for agistment, thereby compromising the capacity of the system to be self-funding. The objective of this study is to explore possible pricing arrangements using a derived demand approach. A representative linear programming model was developed for a farm in Nyngan, NSW. The model was used to obtain estimates of the demand elasticity for TSR services with respect to their own price, the price of supplementary feeds and the price of wool. The effect of drought on these elasticities was also explored.travelling stock reserves, derived demand, grazing, linear programming, Demand and Price Analysis, Livestock Production/Industries,

NASA/DOE/DOD nuclear propulsion technology planning: Summary of FY 1991 interagency panel results

Interagency (NASA/DOE/DOD) technical panels worked in 1991 to evaluate critical nuclear propulsion issues, compare nuclear propulsion concepts for a manned Mars mission on a consistent basis, and to continue planning a technology development project for the Space Exploration Initiative (SEI). Panels were formed to address mission analysis, nuclear facilities, safety policy, nuclear fuels and materials, nuclear electric propulsion technology, and nuclear thermal propulsion technology. A summary of the results and recommendations of the panels is presented

Complete Journal Spring 1984

For historical reasons we have uploaded PDF files for volumes previously published in paper form. Attached you will find the entire volume 1, no. 1 issue from Spring 1984

Multi-Laboratory Results for the Cathodoluminescence Emission Spectrum from a Synthetic Zircon Standard

The Standards Committee of the Society for Luminescence Microscopy and Spectroscopy (SLMS) circulated doped zircon crystals as a standard for comparison of cathodoluminescence (CL) emission spectra obtained at different laboratories. Eleven laboratories have submitted spectra acquired from this standard. The crystals are synthetic zircons doped with 1.4 wt.% of Dy2O3 The participating laboratories used a variety of CL instrumentation including cold cathode optical micro-scope attachments, hot cathode optical microscope attachments, and EMPA/SEM-based systems. Two laboratories provided both uncorrected and corrected spectra. All other spectra are uncorrected. A variety of different spectrometers/spectrographs and detector systems were used. Photomultiplier tubes (PMTs), photo diode arrays, intensified photo diode arrays, and charge coupled devices (CCDs) are represented among the final results. The laboratories with apparently the best resolving power reported 8 peaks in the multiplet at 485 nm. The spectra submitted by some laboratories showed only a single peak at this position. The wavelength scale calibrations were compared by noting the wavelength of the most intense peak in the 485 multiplet. This varied from 476.3 nm to 489 nm among the eleven laboratories. The systems have different overall transmission and detection functions: a combination of the influence of the transmission of the viewing window (typically leaded-glass), the microscope, the fiber optics coupling (if used), the response of the grating and spectrometer/spectrograph, and the detector response. As an initial test of this variation, the ratio of the peak maximum intensity at 575 nm to that at 485 nm was compared. This ratio varied from 0.6 to 3.93 among the eleven laboratories

Adaptive paternal effects? Experimental evidence that the paternal environment affects offspring performance

The ability of females to adaptively influence offspring phenotype via maternal effects is widely acknowledged, but corresponding nongenetic paternal effects remain unexplored. Males can adjust sperm phenotype in response to local conditions, but the transgenerational consequences of this plasticity are unknown. We manipulated paternal density of a broadcast spawner (Styela plicata, a solitary ascidean) using methods shown previously to alter sperm phenotype in the field, then conducted in vitro fertilizations that excluded maternal effects and estimated offspring performance under natural conditions. Offspring sired by males from low-density experimental populations developed faster and had a higher hatching success than offspring sired by males living in high densities. In the field, offspring survived relatively better when their environment matched their father's, raising the possibility that fathers can adaptively influence the phenotype of their offspring according to local conditions. As the only difference between offspring is whether they were artificially fertilized by sperm from males kept in high- vs. low-density cages, we can unequivocally attribute any differences in offspring performance to an environmentally induced paternal effect. Males of many species manipulate the phenotype of their sperm in response to sperm competition: our results show this plasticity can influence offspring fitness, potentially in adaptive ways, raising the possibility that adaptive nongenetic paternal effects may be more common than previously thought

Observed mesoscale eddy signatures in Southern Ocean surface mixed-layer depth

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 617–635, doi:10.1002/2016JC012225.Combining satellite altimetry with Argo profile data a systematic observational estimate of mesoscale eddy signatures in surface mixed-layer depth (MLD) is provided across the Southern Ocean (SO). Eddy composite MLD anomalies are shallow in cyclones, deep in anticyclones, and increase in magnitude with eddy amplitude. Their magnitudes show a pronounced seasonal modulation roughly following the depth of the climatological mixed layer. Weak eddies of the relatively quiescent SO subtropics feature peak late-winter perturbations of ±10 m. Much larger MLD perturbations occur over the vigorous eddies originating along the Antarctic Circumpolar Current (ACC) and SO western boundary current systems, with late-winter peaks of −30 m and +60 m in the average over cyclonic and anticyclonic eddy cores (a difference of ≈ 100 m). The asymmetry between modest shallow cyclonic and pronounced deep anticyclonic anomalies is systematic and not accompanied by corresponding asymmetries in eddy amplitude. Nonetheless, the net deepening of the climatological SO mixed layer by this asymmetry in eddy MLD perturbations is estimated to be small (few meters). Eddies are shown to enhance SO MLD variability with peaks in late winter and eddy-intense regions. Anomalously deep late-winter mixed layers occur disproportionately within the cores of anticyclonic eddies, suggesting the mesoscale heightens the frequency of deep winter surface-mixing events along the eddy-intense regions of the SO. The eddy modulation in MLD reported here provides a pathway via which the oceanic mesoscale can impact air-sea fluxes of heat and carbon, the ventilation of water masses, and biological productivity across the SO.NSF via the MOBY project investigating the impacts of ocean eddies on biogeochemical cycles. In addition, DJM also acknowledges support from NASA.2017-07-2

Eye hazards of laser 'pointers' in perspective

Eight years ago media coverage of incidents involving laser pointers in which individuals claimed to have suffered eye damage resulted in a perspective being published in this journal.1 The final sentence concluded ‘laser pointers, pens or key rings if used appropriately are not an eye hazard, and even if used inappropriately will not cause permanent eye damage’. This statement has been supported by the finding that until recently no irreversible eye injuries had been reported for a period of almost 15 years other than those caused by deliberate and prolonged viewing of laser beams.2 During this time period pointers have been freely available with an estimated 500 000 to c1.2 million laser pointers in circulation