Projecting future grassland productivity to assess the sustainability of potential biofuel feedstock areas in the Greater Platte River Basin

This study projects future (e.g., 2050 and 2099) grassland productivities in the Greater Platte River Basin (GPRB) using ecosystem performance (EP, a surrogate for measuring ecosystem productivity) models and future climate projections. The EP models developed from a previous study were based on the satellite vegetation index, site geophysical and biophysical features, and weather and climate drivers. The future climate data used in this study were derived from the National Center for Atmospheric Research Community Climate System Model 3.0 ‘SRES A1B’ (a ‘middle’ emissions path). The main objective of this study is to assess the future sustainability of the potential biofuel feedstock areas identified in a previous study. Results show that the potential biofuel feedstock areas (the more mesic eastern part of the GPRB) will remain productive (i.e., aboveground grassland biomass productivity >2750 kg ha^?1 year^?1) with a slight increasing trend in the future. The spatially averaged EPs for these areas are 3519, 3432, 3557, 3605, 3752, and 3583 kg ha^?1 year^?1 for current site potential (2000–2008 average), 2020, 2030, 2040, 2050, and 2099, respectively. Therefore, the identified potential biofuel feedstock areas will likely continue to be sustainable for future biofuel development. On the other hand, grasslands identified as having no biofuel potential in the drier western part of the GPRB would be expected to stay unproductive in the future (spatially averaged EPs are 1822, 1691, 1896, 2306, 1994, and 2169 kg ha^?1 year^?1 for site potential, 2020, 2030, 2040, 2050, and 2099). These areas should continue to be unsuitable for biofuel feedstock development in the future. These future grassland productivity estimation maps can help land managers to understand and adapt to the expected changes in future EP in the GPRB and to assess the future sustainability and feasibility of potential biofuel feedstock areas.     

The Global Trade in Fresh Produce and the Vagility of Plant Viruses: A Case Study in Garlic

As cuisine becomes globalized, large volumes of fresh produce are traded internationally. The potential exists for pathogens infecting fresh produce to hitchhike to new locations and perhaps to establish there. It is difficult to identify them using traditional methods if pathogens are novel, scarce, and/or unexpected. In an attempt to overcome this limitation, we used high-throughput sequencing technology as a means of detecting all RNA viruses infecting garlic (Allium sativum L.) bulbs imported into Australia from China, the USA, Mexico, Argentina and Spain, and those growing in Australia. Bulbs tested were grown over multiple vegetative generations and all were stably infected with one or more viruses, including two species not previously recorded in Australia. Present in various combinations from 10 garlic bulbs were 41 virus isolates representing potyviruses (Onion yellow dwarf virus, Leek yellow stripe virus), carlaviruses (Shallot latent virus, Garlic common latent virus) and allexiviruses (Garlic virus A, B, C, D, and X), for which 19 complete and 22 partial genome sequences were obtained, including the first complete genome sequences of two isolates of GarVD. The most genetically distinct isolates of GarVA and GarVX described so far were identified from Mexico and Argentina, and possible scenarios explaining this are presented. The complete genome sequence of an isolate of the potexvirus Asparagus virus 3 (AV3) was obtained in Australia from wild garlic (A. vineale L.), a naturalized weed. This is first time AV3 has been identified from wild garlic and the first time it has been identified beyond China and Japan. The need for routine generic diagnosis and appropriate legislation to address the risks to primary production and wild plant communities from pathogens spread through the international trade in fresh produce is discussed.     

Comprehensive tracking of host cell proteins during monoclonal antibody purifications using mass spectrometry

An advanced two-dimensional liquid chromatography/mass spectrometry platform was used to quantify individual host cell proteins (HCPs) present at various purification steps for several therapeutic monoclonal antibodies (mAbs) produced in Chinese hamster ovary cells. The methodology produced reproducible identifications and quantifications among replicate analyses consistent with a previously documented individual limit of quantification of ~13 ppm. We were able to track individual HCPs from cell culture fluid to protein A eluate pool to subsequent viral inactivation pool and, in some cases, further downstream. Approximately 500 HCPs were confidently identified in cell culture fluid and this number declined progressively through the purification scheme until no HCPs could be confidently identified in polishing step cation-exchange eluate pools. The protein A eluate pool of nine different mAbs contained widely differing numbers, and total levels, of HCPs, yet the bulk of the total HCP content in each case consisted of a small subset of normally intracellular HCPs highly abundant in cell culture fluid. These observations hint that minimizing cell lysis during cell culture/harvest may be useful in minimizing downstream HCP content. Clusterin and actin are abundant in the protein A eluate pools of most mAbs studied. HCP profiling by this methodology can provide useful information to process developers and lead to the refinement of existing purification platforms.     

Potential use of weather radar to study movements of wintering waterfowl

To protect and restore wintering waterfowl habitat, managers require knowledge of routine wintering waterfowl movements and habitat use. During preliminary screening of Doppler weather radar data we observed biological movements consistent with routine foraging flights of wintering waterfowl known to occur near Lacassine National Wildlife Refuge (NWR), Louisiana. During the winters of 2004–2005 and 2005–2006, we conducted field surveys to identify the source of the radar echoes emanating from Lacassine NWR. We compared field data to weather radar reflectivity data. Spatial and temporal patterns consistent with foraging flight movements appeared in weather radar data on all dates of field surveys. Dabbling ducks were the dominant taxa flying within the radar beam during the foraging flight period. Using linear regression, we found a positive log-linear relationship between average radar reflectivity (Z) and number of birds detected over the study area (P < 0.001, r² = 0.62, n = 40). Ground observations and the statistically significant relationship between radar data and field data confirm that Doppler weather radar recorded the foraging flights of dabbling ducks. Weather radars may be effective tools for wintering waterfowl management because they provide broad-scale views of both diurnal and nocturnal movements. In addition, an extensive data archive enables the study of wintering waterfowl response to habitat loss, agricultural practices, wetland restoration, and other research questions that require multiple years of data. © 2011 The Wildlife Society.     

Differential Responses to Virus Challenge of Laboratory and Wild Accessions of Australian Species of Nicotiana,and Comparative Analysis of RDR1 Gene Sequences

Nicotiana benthamiana is a model plant utilised internationally in plant virology because of its apparent hyper-susceptibility to virus infection. Previously, others showed that all laboratory accessions of N. benthamiana have a very narrow genetic basis, probably originating from a single source. It is unknown if responses to virus infection exhibited by the laboratory accession are typical of the species as a whole. To test this, 23 accessions of N. benthamiana were collected from wild populations and challenged with one to four viruses. Additionally, accessions of 21 other Nicotiana species and subspecies from Australia, one from Peru and one from Namibia were tested for susceptibility to the viruses, and for the presence of a mutated RNA-dependent RNA polymerase I allele (Nb-RDR1m) described previously from a laboratory accession of N. benthamiana. All Australian Nicotiana accessions tested were susceptible to virus infections, although there was symptom variability within and between species. The most striking difference was that plants of a laboratory accession of N. benthamiana (RA-4) exhibited hypersensitivity to Yellow tailflower mild mottle tobamovirus infection and died, whereas plants of wild N. benthamiana accessions responded with non-necrotic symptoms. Plants of certain N. occidentalis accessions also exhibited initial hypersensitivity to Yellow tailflower mild mottle virus resembling that of N. benthamiana RA-4 plants, but later recovered. The mutant Nb-RDR1m allele was identified from N. benthamiana RA-4 but not from any of 51 other Nicotiana accessions, including wild accessions of N. benthamiana, demonstrating that the accession of N. benthamiana used widely in laboratories is unusual.     

Lost in translation – a history of systematic confusion and comments on the type species of Squalodon and Patriocetus (Cetacea,Odontoceti)

Abstract: The two odontocete taxa Squalodon grateloupii and Patriocetus ehrlichii, both the type species of their respective genera, have been at the centre of a great deal of taxonomic confusion. Originally regarded to be conspecific, these two taxa have been the subject of a bewildering taxonomic debate lasting for more than a century, which recently led to the suggestion to abandon these widely used names and replace S. grateloupii with the similar, yet independently and later proposed name S. gratelupi as the type species of Squalodon. Here, we attempt to summarise the events leading to the current confused situation in the hope of resolving this issue once and for all and argue that the name Squalodon grateloupii, as originally proposed, should be reinstated.     

Oxidative stress is markedly elevated in lecithin:cholesterol acyltransferase-deficient mice and is paradoxically reversed in the apolipoprotein E knockout background in association with a reduction in atherosclerosis.

Complete lecithin:cholesterol acyltransferase (LCAT) deficiency is a rare cause of severe hypoalphalipoproteinemia, but the affected subjects are surprisingly not particularly prone to premature coronary heart disease. We studied oxidative stress in lcat-/- mice and their cross-breed with apolipoprotein-E knockout mice (apoE-/-xlcat-/-) by measuring vascular ring superoxide production and plasma phospholipid (PL)-bound F2-isoprostane levels and their relationship with aortic atherosclerosis. Compared with wild type control (lcat+/+), lcat-/- and lcat+/- mice showed a 4.9- (p = 0.003) and a 2.1-fold (p = 0.04) increase in plasma PL-F2-isoprostane levels, respectively. There was also a 3.6- (p < 0.0001) and 2.9-fold (p = 0.003) increase in the area under the curve for the aortic ring superoxide excursion by lucigenin-derived chemiluminescence. A comparison of apoE-/-xlcat+/+ mice with wild type control mice showed a more modest 2.1- (p = 0.04) and 2.2-fold (p < 0.00001) increase in these respective markers. Surprisingly, the apoE-/-xlcat-/- mice showed a paradoxical normalization in both oxidation markers. Furthermore, by fast protein liquid chromatography separation, we observed an associated retention and redistribution of serum paraoxonase activities to the non-high density lipoprotein fractions in both the apoE-/-xlcat-/- and apoE-/-xlcat+/- mice. Aortic atherosclerotic lesions in male apoE-/-xlcat-/- and apoE-/-xlcat+/- mice were reduced by 52 (p = 0.02) and 24% (p = 0.46), respectively. Our data suggest that LCAT-deficient mice are associated with an increased oxidative stress that is paradoxically reversed in a hyperlipidemic background, possibly due to the redistribution of paraoxonase. This modulation of oxidative stress may in part contribute to the reduced atherosclerosis seen in the apoE-/- xlcat-/- mice.     

Vaccinia virus membrane proteins p8 and p16 are cotranslationally inserted into the rough endoplasmic reticulum and retained in the intermediate compartment.

The use of two-dimensional gel electrophoresis has identified the gene products A14L (p16) and A13L (p8) as abundant membrane proteins of the first infectious form of vaccinia virus, the intracellular mature virus (IMV; O. N. Jensen, T. Houthaeve, A. Shevchenko, S. Cudmore, T. Ashford, M. Mann, G. Griffiths, J. Krijnse Locker, J. Virol. 70:7485-7497, 1996). In this study, these two proteins were characterized in detail. In infected cells, both proteins localize not only to the viral membranes but also to tubular-cisternal membranes of the intermediate compartment, defined by the use of antibodies to either rab1A or p21, which colocalize with rab1A (J. Krijnse Locker, S. Schleich, D. Rodriguez, B. Goud, E. J. Snijder, and G. Griffiths, J. Biol. Chem. 271:14950-14958, 1996). Both proteins appear to reach this destination via cotranslational insertion into the rough endoplasmic reticulum, as shown by in vitro translation and translocation experiments. Whereas p16 probably spans the membrane twice, p8 is inserted into the membrane by means of its single NH2-terminal hydrophobic domain, adopting a topology which leaves the C terminus exposed to the cytoplasm. Combined immunocytochemical and biochemical data show that p16 is a member of the inner of the two IMV membrane layers, whereas p8 localizes to both the inner and the outer membrane. These findings are discussed with respect to our model of IMV membrane assembly.