1,216 research outputs found

    Forage Brassica use in New Zealand and Australia Farming Systems

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    Forage brassica, genus Brassica, are annual feed crops grown on farming enterprises throughout New Zealand and Australia. These crops provide a source of high-yielding, high-quality feed, which is particularly useful to complement pasture production during periods when pasture growth is reduced. There are six forage brassica species and subspecies of agricultural importance including bulb turnip, swede, kale, forage rape, leafy turnip, and raphanobrassica. All of these, as well as interspecific crosses and individual cultivars, offer a range of characteristics to fit various environmental and livestock production challenges. Consumption of forage brassica crops in ruminant animals may reduce methane emissions compared to traditional feed sources. Furthermore, recent technological developments using seed mutagenesis in breeding new forage brassica provide increased herbicide control of weed species. As with all feed sources, specific management, crop husbandry and animal health considerations apply. Overall, the use of forage brassica enables increased resilience in typical pasture-based farm systems

    Developments in the Use of Plantain (\u3cem\u3ePlantago lanceolata\u3c/em\u3e) Cultivars in New Zealand Pastures

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    The use of pasture herbs, such as chicory, is commonplace in New Zealand in recent years. This has stimulated interest in other herb species such as plantain (Plantago lanceolata) that often occurs as a ubiquitous weed in temperate pastures throughout the world. In the last decade 2 improved commercial cultivars, Grasslands Lancelot (Rumball et al., 1997) and the erect, winter active Ceres Tonic (Stewart, 1996), have been bred in New Zealand for use in pastures. These cultivars have useful agronomic features that make them valuable for grazing. They are productive in mixtures, palatable to grazing animals, and tolerate a wide range of soils and dryland conditions (Stewart, 1996; Stewart & Charlton, 2003)

    Examining Healthcare Institutions by Bringing Qualitative Data from Two Eras into Empirical Dialogue

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    In this paper, we argue that there is new insight to be gained by reexamining the classic text, Boys in White, in strategic ways. Specifically, we share excerpts from Boys in White with current medical students and ask for their reactions in qualitative interviews, examining the relevance (or lack thereof) of earlier meanings about professional training for current processes of professional training. We show how we have employed this technique in our current project revisiting Boys in White with current medical students, and discuss preliminary findings that reveal the potential of this technique for documenting evidence of macro-level forces in healthcare institutions using qualitative data on new doctors. We conclude with discussion of alternative approaches through which scholars could make use of this technique in future professional socialization scholarship that could shed light on dynamics of institutional persistence and change

    Soil Nitrification Inhibition with Plantain (\u3ci\u3ePlantago lanceolata\u3c/i\u3e)

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    One strategy to reduce nitrogen losses from intensively grazed forage systems is to slow the first stage of soil nitrification, specifically inhibiting the microbial oxidation of ammonium to nitrite. Plantain (Plantago lanceolata) leaves and roots are known to contain several bioactive compounds (e.g., aucubin, catalpol and verbascoside) that may contribute to this inhibition. Recent laboratory studies indicate that this inhibition occurs via consumption by grazing animals of precursor bioactive compounds in aboveground biomass and their subsequent excretion as secondary metabolites in urine and/or via active exudation from the roots. Different cultivars of plantain have been shown to impart differing nitrification inhibition activity via both mechanisms. The urinary effect was assessed by determination of net soil nitrification in soil microcosms treated with urine from sheep fed a diet containing either perennial ryegrass or plantain. Analyses showed significant treatment effects on the rate of net nitrification and microbial community structure over time. A preliminary evaluation of the root exudate effect involved the collection of root exudates from six plantain cultivars grown in a hydroponic system. The assay of the root exudates against a pure culture of an ammonium-oxidising bacterium indicated differences in the amount of inhibition imparted by the exudates of each cultivar. The exact means of soil nitrification inhibition by either mechanism is as yet unconfirmed. However, it is likely that these compounds (or derivatives thereof) inhibit the first enzymatic step of nitrification directly, without harm to the soil microbiome as a whole

    Beable trajectories for revealing quantum control mechanisms

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    The dynamics induced while controlling quantum systems by optimally shaped laser pulses have often been difficult to understand in detail. A method is presented for quantifying the importance of specific sequences of quantum transitions involved in the control process. The method is based on a ``beable'' formulation of quantum mechanics due to John Bell that rigorously maps the quantum evolution onto an ensemble of stochastic trajectories over a classical state space. Detailed mechanism identification is illustrated with a model 7-level system. A general procedure is presented to extract mechanism information directly from closed-loop control experiments. Application to simulated experimental data for the model system proves robust with up to 25% noise.Comment: Latex, 20 pages, 13 figure

    FAST CARS: Engineering a Laser Spectroscopic Technique for Rapid Identification of Bacterial Spores

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    Airborne contaminants, e.g., bacterial spores, are usually analyzed by time consuming microscopic, chemical and biological assays. Current research into real time laser spectroscopic detectors of such contaminants is based on e.g. resonant Raman spectroscopy. The present approach derives from recent experiments in which atoms and molecules are prepared by one (or more) coherent laser(s) and probed by another set of lasers. The connection with previous studies based on "Coherent Anti-Stokes Raman Spectroscopy" (CARS) is to be noted. However generating and utilizing maximally coherent oscillation in macromolecules having an enormous number of degrees of freedom is much more challenging. This extension of the CARS technique is called FAST CARS (Femtosecond Adaptive Spectroscopic Techniques for Coherent Anti-Stokes Raman Spectroscopy), and the present paper proposes and analyses ways in which it could be used to rapidly identify pre-selected molecules in real time.Comment: 43 pages, 21 figures; replacement with references added. Submitted to the Proceedings of National Academy of Science

    Risk factors for 1-year mortality after thoracic endovascular aortic repair

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    ObjectiveThoracic endovascular aortic repair, although physiologically well tolerated, may fail to confer significant survival benefit in some high-risk patients. In an effort to identify patients most likely to benefit from intervention, the present study sought to determine the risk factors for 1-year mortality after thoracic endovascular aortic repair.MethodsA retrospective review was performed on prospectively collected data from all patients undergoing thoracic endovascular aortic repair from 2002 to 2010 at a single institution. Univariate analysis and multivariate Cox proportional hazards regression analysis were used to identify risk factors associated with mortality within 1 year after thoracic endovascular aortic repair.ResultsDuring the study period, 282 patients underwent at least 1 thoracic endovascular aortic repair; index procedures included descending aortic repair (n = 189), hybrid arch repair (n = 55), and hybrid thoracoabdominal repair (n = 38). The 30-day/in-hospital mortality was 7.4% (n = 21) and the overall 1-year mortality was 19% (n = 54). Cardiopulmonary pathologies were the most common cause of nonperioperative 1-year mortality (22%, n = 12). Multivariate modeling demonstrated 3 variables independently associated with 1-year mortality: age older than 75 years (hazard ratio, 2.26; P = .005), aortic diameter greater than 6.5 cm (hazard ratio, 2.20; P = .007), and American Society of Anesthesiologists class 4 (hazard ratio, 1.85; P = .049). A baseline creatinine greater than 1.5 mg/dL (hazard ratio, 1.79; P = .05) and congestive heart failure (hazard ratio, 1.87; P = .08) were also retained in the final model. These 5 variables explained a large proportion of the risk of 1-year mortality (C statistic = 0.74).ConclusionsAge older than 75 years, aortic diameter greater than 6.5 cm, and American Society of Anesthesiologists class 4 are independently associated with 1-year mortality after thoracic endovascular aortic repair. These clinical characteristics may help risk-stratify patients undergoing thoracic endovascular aortic repair and identify those unlikely to derive a long-term survival benefit from the procedure

    Optimal Control of Molecular Motion Expressed Through Quantum Fluid Dynamics

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    A quantum fluid dynamic control formulation is presented for optimally manipulating atomic and molecular systems. In quantum fluid dynamic the control quantum system is expressed in terms of the probability density and the quantum current. This choice of variables is motivated by the generally expected slowly varying spatial-temporal dependence of the fluid dynamical variables. The quantum fluid dynamic approach is illustrated for manipulation of the ground electronic state dynamics of HCl induced by an external electric field.Comment: 18 pages, latex, 3 figure

    Hydrogeomorphology of the Hyporheic Zone: Stream Solute and Fine Particle Interactions With a Dynamic Streambed

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    Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 ÎĽm latex particles), a surrogate for fine particulate organic matter, were co-injected during base flow. The tracers were differentially stored, with fine particles penetrating more shallowly in hyporheic flow and retained more efficiently due to the high rate of particle filtration in bed sediment compared to solute. Tracer injections lasted 3.5 h after which we released a small flood from an upstream dam one hour later. Due to shallower storage in the bed, fine particles were rapidly entrained during the rising limb of the flood hydrograph. Rather than being flushed by the flood, we observed that solutes were stored longer due to expansion of hyporheic flow paths beneath the temporarily enlarged bedforms. Three important timescales determined the fate of solutes and fine particles: (1) flood duration, (2) relaxation time of flood-enlarged bedforms back to base flow dimensions, and (3) resulting adjustments and lag times of hyporheic flow. Recurrent transitions between these timescales explain why we observed a peak accumulation of natural particulate organic matter between 2 and 4 cm deep in the bed, i.e., below the scour layer of mobile bedforms but above the maximum depth of particle filtration in hyporheic flow paths. Thus, physical interactions between bed mobility and hyporheic transport influence how organic matter is stored in the bed and how long it is retained, which affects decomposition rate and metabolism of this southeastern Coastal Plain stream. In summary we found that dynamic interactions between hyporheic flow, bed mobility, and flow variation had strong but differential influences on base flow retention and flood mobilization of solutes and fine particulates. These hydrogeomorphic relationships have implications for microbial respiration of organic matter, carbon and nutrient cycling, and fate of contaminants in streams
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