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111.
M Boller K Kelers MA Stevenson KD Winkel S Hardjo J Heller PR Judge HM Ong AM Padula C Reddrop LCP Santos CR Sharp L Smart KL Swindells D Tabrett JR Wierenga 《Australian veterinary journal》2020,98(9):442-448
SnakeMap is a national cloud-based, veterinary snakebite registry. It was designed to prospectively collect data of the clinical circumstances and temporospatial information on cases of snake envenomation in dogs and cats. We herein introduce the project and summarise the data from the first 4 years of SnakeMap. The registry is a veterinary community-based online database allowing case entry from veterinary hospitals across Australia. Registry data comprise hospital characteristics, patient characteristics, envenoming snake type, treatment and outcome variables, including time and geolocation of the snake bite. We present summative information on select key variables from the SnakeMap registry (1 July 2015 to 30 June 2019). Twenty-eight hospitals from 6 states/territories entered 624 cases into the registry, including 419 dogs (67%) and 205 cats (33%). Bite time was available in 216 animals of which 90 (42%) were reported to be bitten in the 3 hours between 03:00 pm and 05:59 pm; median bite to presentation interval was 60 (interquartile range [IQR] 30, 211) minutes in dogs and 95 (IQR 41, 238) minutes in cats. Bites occurred in the owner's yard in 356 dogs (85%) and 53 cats (26%). A snake venom detection kit was used in 172 cases (28%) and antivenom was administered in 523 cases (85%). Most animals (n = 534, 88%) survived to discharge (median hospitalisation of 25 [IQR 16, 62] hours). SnakeMap effectively collects relevant clinical data from dogs and cats with presumed snake bite and provides locally specific information on the epidemiology of snake envenomation in small animals. 相似文献
112.
Francisco Mamani-Pati David E. Clay Gregg Carlson Sharon A. Clay 《Journal of plant nutrition》2013,36(9):1278-1289
To prepare for a carbon (C) constrained economy, crop production energy audits or life cycle analysis (LCA) must be conducted. However, energy audits may not maximize profitability. This study conducted simultaneous production, economic, and energy audits to evaluate differences among these assessments. The 2005 and 2006 South Dakota field experiment contained two nitrogen (N; 0 and 224 kg N ha?1) rates, two corn population levels (76,500 and 149,000 plants ha?1), and two simulated landscape positions (upper backslope and lower backslope). The energy inputs, outputs, and net energy gain for corn grain used in ethanol production were calculated using the Nebraska Biofuel Energy Simulator (BESS) version 2008.3.1. For LC analysis, corn grain was used in ethanol production and dry distiller's grain was used as a livestock feed. Manure was not applied to the field. A partial economic analysis to examine profitability was conducted where seed, N fertilizer, and corn values were $312 (100,000 seeds)?1, $1.25 (kg N)?1, and $158 (Mg grain at 15.5% moisture)?1, respectively. Results showed that: 1) to maximize profitability and energy gains, inputs must closely match crop needs for a site; 2) increasing the population level from 74,500 to 149,000 plants ha?1 increased energy input and output, increased yield and energy gain by 11%, but did not influence profitability; 3) increasing N from 0 to 224 kg N ha?1 increased yield 7%, reduced profit by $145/ha, increased energy input and output values, but did not impact energy gain; and 4) corn grown in high yielding areas of landscapes may have higher yields (P = 0.08), profitability (P = 0.08), and energy gains (P = 0.08) than other areas. These calculations demonstrate that yield, profitability, and energy audits may have divergent results. 相似文献
113.
Abstract Nutrient solution experiments were conducted in the growth chamber to study the influence of rootstock, solution Ca/Mg ratios and solution nickel on K uptake. The experimental plants were one‐year‐old prune trees: ‘French’ prune (Prunus domestica L.) scions grafted on Myrobalan 29C (P. cerasifera Ehrh.), Marianna 2624 (P. cerasifera x P. munsoniana?) or Nemaguard (P. persica x P. davidiana) rootstocks. Ion uptake parameters Imax, Km, and Cmin were calculated from ion depletion measurements over a 6 to 10‐hr period. With K solution concentrations initially adjusted to 100 μM, K uptake rates of Prunus rootstocks were constant down to approximately 20–30 μM, then declined. Rootstocks were able to deplete solution K to concentrations less than 1 μM. There were no significant differences in K uptake parameters among the rootstocks tested. Varying solution Ca/Mg ratio from 2.75/1 to 1/4 (Ca + Mg = 3.75 mM) had no effect on K uptake. Potassium uptake rates of Myrobalan 29C rootstocks in the presence of 100 μM nickel were not significantly different from those in the absence of nickel. Rates of nickel uptake were significantly lower than those of K. After eight days of pretreatment in solutions adjusted daily to 100 μM Ni(NO3)2, prune leaves began to show signs of interveinal chlorosis. Potassium uptake by nickel pretreated trees was not significantly different from that by control trees. Results are discussed in relation to field observations of K deficiency in prune orchards. 相似文献
114.
An inexpensive and mechanically simple technique has been developed to maintain realistically low P concentrations in nutrient solutions using a solid‐phase buffer. Phosphate is adsorbed on alumina in a PVC column, and the resulting alumina‐F is desorbed against nutrient solution circulated through the column. Kinetics of P adsorption and desorption indicate that the solid‐phase‐P has rapidly and slowly desorbing components and that buffering capacity is limited by desorption from the solid phase. The technique has been used to maintain F concentrations as low as 0.4 minol m‐3 for 26 days in experiments with maize (Zea mays L.), and in solution cultures with prune (Prunus domestica L.) trees. Effects of P supply on P accumulation and P transport are discussed. 相似文献
115.
Cropping sequence and tillage system influences annual crop production and water use in semiarid Montana,USA 总被引:1,自引:0,他引:1
Available water is typically the biggest constraint to spring wheat production in the northern Great Plains of the USA. The most common rotation for spring wheat is with summer fallow, which is used to accrue additional soil moisture. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water, decreasing the efficiency of fallow. Chemical fallow and zero tillage systems improve soil water conservation, allowing for increased cropping intensity. We conducted a field trial from 1998 through 2003 comparing productivity and water use of crops in nine rotations under two tillage systems, conventional and no-till. All rotations included spring wheat, two rotations included field pea, while lentil, chickpea, yellow mustard, sunflower, and safflower were present in single rotations with wheat. Growing season precipitation was below average most years, resulting in substantial drought stress to crops not following fallow. Preplant soil water, water use, and spring wheat yields were generally greater following summer fallow than wheat recropped after wheat or alternate crops. Water use and yield of wheat following summer fallow was greater than for chickpea or yellow mustard, the only other crops in the trial that followed summer fallow. Field pea performed best of all alternate crops, providing yields comparable to those of recropped spring wheat. Chickpea, lentil, yellow mustard, safflower, and sunflower did not perform well and were not adapted to this region, at least during periods of below average precipitation. Following summer fallow, and despite drought conditions, zero tillage often provided greater amounts of soil water at planting compared to conventional tillage. 相似文献
116.
Oviposition by the potato leafhopperEmpoasca fabae was measured on detached leaflets from nine half-sib groups (18 full-sib families) of tetraploid potatoes. The parents were clones that had been used in the USDA breeding program. Significant differences occurred among full-sib families, and between full-sib families with a common parent, but not among half-sib groups. The variance component for between full-sib families with a common parent averaged over twice as large as the component due to differences among half-sib groups. Although this could be due to intra-locus interaction, it seemed that common environmental effects were a more likely cause. Previous feeding on beans affected leafhopper oviposition in the first 4-day test period. By the 2nd test period the effect had disappeared, and results in test periods 2, 3, and 4 were consistent with each other. With a procedure including a feeding period on potatoes before testing, phenotypic selection of individuals was shown to be more efficient than selection by progeny testing with half or full-sib families for increasing resistance to oviposition. The ranking of families by the amount of oviposition on detached leaflets and by nymph infestation densities in the field were similar at the extremes of the resistance range, but variable in between. 相似文献
117.
Chao Li Harinder Hans Hugh Barclay Jianwei Liu Greg Carlson Doug Campbell 《Forest Ecology and Management》2008
Comparisons of model behaviors are an efficient way of understanding the differences amongst various models and thus providing guidance to model users for selecting suitable models for their own purposes. This study focuses on a comparison of the most commonly used fire spread algorithms used in scenario fire regime models. This paper provides an overview of fire regime modeling and describes a simulation model, Ecological Disturbance Model, as a simulation shell for such a comparison using the Fort A La Corne forest area in central Saskatchewan, Canada, as the study area. Simulation results suggested that for a fire scenario modeling approach, various fire spread algorithms such as DISPATCH, percolation, and cellular automata (CA) may not result in significant differences between user-defined and simulated fire frequencies; however, significant differences in simulated forest dynamics could result when using different fire spread algorithms. The simulation results from DISPATCH and CA are more similar than those from the percolation algorithm; however, the latter appeared to be a better representative of observed fire spread processes due to its underlying assumption of fire spread mechanisms. Simulation results also suggested that the fire spread algorithms that replicate four or eight direction fire spread in percolation and CA will not make a significant difference in simulated fire regimes or forest dynamics. It is thus recommend that using simulation shells as a tool to take alternative assumptions or models into account to narrow down the uncertainty parameters and avoid the paradoxes in the modeling of natural resource management. 相似文献
118.
Colleen A. Carlson Thomas R. Fox H. Lee Allen Timothy J. Albaugh Forest Nutrition Cooperative 《Forest Ecology and Management》2008,256(3):256
Growth and yield modelers have incorporated mid-rotation fertilizer responses by: modifying site index; developing new models to include fertilizer responses directly; using multipliers or additional terms to scale existing models. We investigated the use of age-shifts to model mid-rotation fertilizer responses. Age-shift prediction models were constructed from 43 installations of a nitrogen (0, 112, 224 and 336 kg ha−1 elemental) by phosphorus (0, 28 and 56 kg ha−1 elemental) factorial experiment established in mid-rotation loblolly (Pinus taeda L.) pine stands in the southeastern US. Age-shifts for dominant height and basal area increased with time after fertilization, to a maximum and then either remained fairly constant, or declined. The initial rate of increase, maximum age-shift and decline were functions of the rate and combinations of fertilizers applied, as well as stand density and age at fertilization. Volume age-shifts increased linearly throughout the 10-year measurement period for most treatments with the rate of increase being a function of the elements applied, stocking, site index and age at fertilization. A mid-rotation fertilizer application of 224 and 28 kg ha−1 elemental N and P, respectively, resulted in age-shifts of 1.1, 1.9 and 2.4 years for dominant height, basal area and volume, respectively, 10 years after fertilization. The age-shifts were incorporated into growth and yield models. 相似文献
119.
By accounting for spatial variation in soil N levels, variable-rate fertilizer application may improve crop yield and quality, and N use efficiency within fields. The main purpose of this study was to demonstrate how site-specific wheat yield and protein data, and a geographic information system may be used in developing precision N-recommendations for spring wheat. The three steps in the procedure include: (1) estimate the amount of N-removed in wheat in the year in which the crop is harvested, (2) estimate the N-deficit, defined as the amount of additional N needed for raising protein concentration in a future crop to a specified target level, and (3) estimate the total N-recommendation by summing the mapped values of the N-removed and the N-deficit. A map for variable-rate application of fertilizer is derived by specifying cutoff values to divide the range in the total N-recommendation into classes representing N management zones.A field experiment was conducted within an annually cropped wheat field (101 ha) in northern Montana to determine whether the proposed method could improve grain yields and protein levels. The N-removal and N-deficit were estimated from site-specific wheat yield and protein data that were acquired during harvest of 1996. In 1997, which was a dry year, an experiment was conducted in the same field that consisted of a randomized complete block design arranged as pairs of strip plots. Variable- or uniform-rate N treatments were randomly assigned to each pair of strips. Both treatments received nearly the same amount of fertilizer, however, N in the variable treatment was varied to match patterns in grain yield and protein levels that previously existed in 1996. Yields were not significantly different between management systems, but proteins were significantly enhanced by spatially variable N application. In addition, variability in protein levels was reduced within the whole field. Field areas deficient in N fertility could be identified without having to sample for soil profile N. 相似文献
120.
Two feeding trials of 8 and 10 weeks each were conducted to quantify the dietary lysine requirement of juvenile striped bass, Morone saxatilis. Diets in both experiments contained approximately 420 g crude protein kg–1 and 13.4 MJ digestible energy (DE) kg?1. L ‐Lysine‐HCl was added to the basal diet to yield five and six treatments in the two experiments. Diets in the first experiment were determined to contain 9.2, 14.1, 14.6, 19.9 and 21.0 g available lysine kg?1 on a dry‐matter basis. Diets in the second experiment were determined to contain 14.8, 18.1, 21.3, 24.5, 27.6 and 30.9 g available lysine kg?1 on a dry‐matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and apparent nitrogen utilization (ANU) were significantly (P < 0.05) improved by increasing dietary lysine concentrations to approximately 20 g kg?1 of diet. Least‐squares regression analysis of weight gain and SGR in the first experiment indicated a minimum dietary lysine requirement of 20.1 ± 2 g kg?1 dry diet. Least‐squares regression analysis of the same criteria measured in the second experiment yielded the following estimates of dietary lysine requirements (g kg?1 dry diet): 19.8 ± 2.3 for weight gain, 21.7 ± 1.5 for SGR, 23.7 ± 3.5 for FCR and 18.6 ± 1.3 for ANU. From these results the minimum recommended dietary lysine requirement for optimal growth of juvenile striped bass is approximately 21 g kg?1 dry diet which equates to 49 g kg?1 dietary protein or 1.57 mg kJ?1 DE. Although higher than that reported for hybrid striped bass, this requirement level is similar to those reported for many other fish species. 相似文献