Productivity pathways: climate-adjusted production frontiers for the Australian broadacre cropping industry

This study introduces two advances to the aggregate productivity index methodology typically employed by ABARES. First, it accounts for the effects of climate variability on measured productivity by matching spatial climate data to individual farms in the ABARES farm surveys database. Second, a farm-level production frontier estimation technique is employed to facilitate the decomposition of productivity change into several key components, including technical change and technical efficiency change. The study makes use of farm-level data from the ABARES Australian agricultural and grazing industries survey database. An unbalanced panel dataset is constructed containing 13 430 observations (4255 farms) over the period 1977–78 to 2007–08. Spatial climate data, including winter and summer seasonal rainfall and average maximum and minimum temperatures, were obtained via the Australian Water Availability Project. These data were mapped to individual farms using Geographic Information System methods. The study employed stochastic frontier analysis methods to estimate a production frontier with time varying technical efficiency effects of the form proposed by Battese and Coelli (1992). Production frontiers are estimated for each of the three major Grains Research and Development Corporation regions: southern, northern and western. Selected climate variables are shown to display a high degree of explanatory power over farm output. The results confirm that deterioration in average climate conditions has contributed significantly to the decline in estimated productivity over the post-2000 period. Technical change is shown to be the primary driver of productivity growth in the industry in the long run, offset by a gradual decline in technical efficiency. After controlling for climate variability, a gradual decline in the rate of technical change is still observed.Productivity Analysis,

Spot-on: Safe Fuel/Air Compression

The emission of fuel vapors into the atmosphere from underground storage tanks at filling stations is a common occurrence in many parts the world. The conditions of the vapor in the tanks vary significantly over a 24 hour period such that evaporation and excess air ingestion during the refueling process can cause tank over pressurization and subsequent emissions. At other times during a 24 hour cycle, pressures can fall below atmospheric pressure. The state of California has recognized this emissions problem and has enacted regulations to address it. Due to these low-emission environmental requirements in California, solutions must be implemented that do not entail release of these vapors into the atmosphere. One solution requires that the vapors fill a balloon during the appropriate times. However, the size of the balloon at typical inflation rates requires a significant amount of physical space (approximately 1000-2000 liters), which may not necessarily be available at filling stations in urban areas. Veeder-Root has a patent pending for a system to compress the vapors that are released to a 10:1 ratio, store this compressed vapor in a small storage tank, and then return the vapors to the original underground fuel tank when the conditions are thermodynamically appropriate (see Figure 1 for the schematic representation of this system). The limitation of the compressor, however, is that the compression phase must take place below the ignition temperature of the vapor. For a 10:1 compression ratio, however, the adiabatic temperature rise of a vapor would be above the ignition temperature. Mathematical modeling is necessary here to estimate the performance of the compressor, and to suggest paths in design for improvement. This report starts with a mathematical formulation of an ideal compressor, and uses the anticipated geometry of the compressor to state a simplified set of partial differential equations. The adiabatic case is then considered, assuming that the temporary storage tank is kept at a constant temperature. Next, the heat transfer from the compression chamber through the compressor walls is incorporated into the model. Finally, we consider the case near the valve wall, which is subject to the maximum temperature rise over the estimated 10,000 cycles that will be necessary for the process to occur. We find that for adiabatic conditions, there is a hot spot close to the wall where the vapor temperature can exceed the wall temperature. Lastly, we discuss the implications of our analysis, and its limitations

Immune sensing of Candida albicans requires cooperative recognition of mannans and glucans by lectin and Toll-like receptors

Peer reviewedPublisher PD

Antarctic geoconservation: a review of current systems and practices

The prohibition of commercial mineral resource extraction through the Antarctic Treaty System has removed one significant source of potential damage to Antarctica's geological and geomorphological values. However, given the on-going increase in Antarctic tourism and scientific footprint, some high-quality geological features may be vulnerable to human impact, such as damage due to the construction of logistical facilities, unregulated collection of geological specimens or oversampling for scientific purposes. The Protocol on Environmental Protection to the Antarctic Treaty puts in place a framework for the protection of Antarctica's environmental, scientific, historic, wilderness and aesthetic values. However, the Antarctic Protected Area system is still immature and further implementation of existing management tools may be required to protect the diverse range of vulnerabilities, qualities and spatial scales represented in the geology and geomorphology of the continent. At sites where high-quality mineralogical or palaeontological specimens exist in limited quantities, considerations of how best to prevent oversampling and manage access to remaining material may be supported by assessment of cumulative impacts. Examination of the level of Antarctic specimen loans from a selection of national geological collections suggested that existing publically accessible geological collections could be better utilized, which could reduce environmental impact and oversampling at vulnerable Antarctic sites

Antarctic geoconservation: a review of current systems and practices

The prohibition of commercial mineral resource extraction through the Antarctic Treaty System has removed one significant source of potential damage to Antarctica's geological and geomorphological values. However, given the on-going increase in Antarctic tourism and scientific footprint, some high-quality geological features may be vulnerable to human impact, such as damage due to the construction of logistical facilities, unregulated collection of geological specimens or oversampling for scientific purposes. The Protocol on Environmental Protection to the Antarctic Treaty puts in place a framework for the protection of Antarctica's environmental, scientific, historic, wilderness and aesthetic values. However, the Antarctic Protected Area system is still immature and further implementation of existing management tools may be required to protect the diverse range of vulnerabilities, qualities and spatial scales represented in the geology and geomorphology of the continent. At sites where high-quality mineralogical or palaeontological specimens exist in limited quantities, considerations of how best to prevent oversampling and manage access to remaining material may be supported by assessment of cumulative impacts. Examination of the level of Antarctic specimen loans from a selection of national geological collections suggested that existing publically accessible geological collections could be better utilized, which could reduce environmental impact and oversampling at vulnerable Antarctic sites

BVRI Light Curves for 29 Type Ia Supernovae

BVRI light curves are presented for 27 Type Ia supernovae discovered during the course of the Calan/Tololo Survey and for two other SNe Ia observed during the same period. Estimates of the maximum light magnitudes in the B, V, and I bands and the initial decline rate parameter m15(B) are also given.Comment: 17 pages, figures and tables are not included (contact first author if needed), to appear in the Astronomical Journa

Gene content evolution in the arthropods

Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity

Automated Sentinel-1 ice type mapping and in-situ validation during the CIRFA-22 cruise

We present a fully-automated workflow to map sea ice types from Sentinel-1 data and transfer the results in near real-time to the research vessel Kronprins Haakon (KPH) in order to support tactical navigation and decision-making during a research cruise conducted towards Belgica Bank in April and May 2022. We used overlapping SAR and optical imagery to train a pixel-wise classifier for the required season and region, and implemented a processing chain with the Norwegian Ice Service at MET Norway that automatically classifies all Sentinel-1 images covering the area of interest. During the cruise, classification results were available on KPH within hours after image acquisition, which is significantly faster than manually produced ice charts. We evaluate the results both quantitatively, based on manually selected validation regions, and qualitatively in comparison to in-situ observations and photographs. Our findings show that open water, level ice, and deformed ice are classified with high accuracy, while young ice remains challenging due to its variable small-scale surface roughness. This work presents one of the first attempts to transfer automated ice type classification results into the field in near real-time and contributes to bridging the gap between research and operations in automated sea ice mapping