Factors leading to spatiotemporal variability of soil moisture and turfgrass quality within sand-capped golf course fairways     

Hejl  Reagan  Straw  Chase  Wherley  Benjamin  Bowling  Rebecca  McInnes  Kevin 《Precision Agriculture》2022,23(5):1908-1917

Precision irrigation utilizing soil moisture data and valve-in head sprinkler systems may be a viable solution for sustainable water management on complex turfgrass areas. There is currently no research investigating the factors that influence soil moisture and turfgrass quality variability within sand-capped golf course fairways to aid in precision irrigation-related management decisions. Therefore, the objective of this study was to measure several turfgrass and soil characteristics from two sand-capped fairways during dry down events from either rainfall or irrigation to determine their relationship and contribution to soil moisture and turfgrass quality variability. Considerable spatiotemporal variability was observed within the two fairways during the dry down periods. Factors that were found to have a significant influence on soil moisture and turfgrass quality were sand capping depth, elevation, and thatch depth, but these relationships were not consistent between rainfall versus irrigation events, days after dry down, or even the specific fairways. Also, the direction of many of the relationships were opposite of what was expected. These findings highlight the complexity of soil moisture and turfgrass quality variability on sand-capped golf course fairways. To incorporate soil moisture sensor technologies into large-scale precision irrigation practices, mapping soil moisture with an understanding of contributing factors is a necessary preliminary step. Although there are several current practical limitations, the information presented in this study provides a foundation for future research.

  相似文献   

Handling Alternative Dietary Requests from Pet Owners     

Jacqueline M. Parr  Rebecca L. Remillard 《Veterinary Clinics of North America: Small Animal Practice》2014

  相似文献   

Cytotoxic Effects of Loperamide Hydrochloride on Canine Cancer Cells     

Rebecca Cohen REGAN  Robert Michael GOGAL  Jr  James Perry BARBER  Richard Cary TUCKFIELD  Elizabeth Wynne HOWERTH  Jessica Ann LAWRENCE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1563-1568

Loperamide is a peripheral opiate agonist that can cause apoptosis and G2/M arrest in human cancer cell lines and may sensitize cells to chemotherapy. The objectives of this study were to investigate the effects of loperamide on viability, apoptosis and cell cycle kinetics in canine cancer cells and to establish whether the drug sensitizes cells to doxorubicin. Cell viability was assessed using Alamar Blue. Cell death and cell cycle were studied using flow cytometry with 7-Aminoactinomycin-D (7-AAD) and propidium iodide (PI), respectively. Loperamide decreased cell viability in a dose-dependent fashion and was most effective against canine osteosarcoma cells. In all cell lines, it induced a dose and time dependent apoptosis and resulted in accumulation in G0/G1. When co-incubated with doxorubicin, loperamide induced a synergistic cell kill in canine carcinoma cells. Investigation is warranted into the role of loperamide in the treatment of canine cancer.  相似文献   

Myocardial injury in dogs with snake envenomation and its relation to systemic inflammation     

Rebecca Langhorn  Frida Persson  Bjrn blad  Amelia Goddard  Johan P. Schoeman  Jakob L. Willesen  Inge Tarnow  Mads Kjelgaard‐Hansen 《Journal of Veterinary Emergency and Critical Care》2014,24(2):174-181

  相似文献   

Using social media as a cost‐effective resource in the photo‐identification of a coastal bottlenose dolphin community     

Catherine Elizabeth Gibson  David Williams  Rebecca Dunlop  Suzanne Beck 《水产资源保护:海洋与淡水生态系统》2020,30(8):1702-1710

1. Bottlenose dolphins encountered around the Irish coast are considered part of a wide‐ranging coastal community; however, knowledge on the significance of the north of Ireland for this species is limited by a lack of dedicated effort.
2. Through social media, the opportunity now exists to gather large volumes of citizen science data in the form of high‐quality images, potentially extending the spatial and temporal scope of photo‐identification studies.
3. The purpose of this study was to investigate social media as a data resource for photo‐identification studies and to provide a preliminary assessment of bottlenose dolphins in the north of Ireland. Specifically, the study sought to examine the photo‐identification data for spatial clustering.
4. The study identified 54 well‐marked individuals and provided evidence of potential year‐round occurrence, with successful re‐sightings throughout the study period (2007–2016). There was a geographic concentration of re‐sightings along the north of Ireland, suggestive of interannual site fidelity. These results provide scientific rationale for strategically targeting the north of Ireland in future research on the Irish coastal community.
5. For effective conservation of the bottlenose dolphin it is imperative that scientific research, and resultant management objectives, consider wide‐ranging communities such as the Irish coastal community. Our research highlights data collection via social media as a cost‐effective and scientifically valuable tool in the photo‐identification of coastal cetaceans. We recommend that this method is used in research on low‐density and wide‐ranging coastal cetaceans.

  相似文献   

Development of a whole-body cortisol extraction procedure for determination of stress in golden shiners, <Emphasis Type="Italic">Notemigonus crysoleucas</Emphasis>     

Todd David Sink  Sathyanand Kumaran  Rebecca T. Lochmann 《Fish physiology and biochemistry》2007,33(3):189-193

Baitfish such as golden shiners are subjected to stress during harvesting, grading, and transport. Their small size makes it difficult to measure the stress response with the biological indicator cortisol using conventional assay methods for plasma. This paper examines the development and validation of methods for whole-body cortisol extraction from individual baitfish. Three types of extracts were tested: (1) an ethyl ether unaltered extract (UA); (2) an extract reconstituted in phosphate buffered saline (PBS); (3) an extract that had been increased in volume by the addition of food-grade vegetable oil (VO). These extracts were evaluated using validation tests with radioimmunoassays (RIA) and enzyme-linked immunosorbent assays (ELISA). The UA extract produced inadequate volumes of extract for multiple assays and could not be used for the determination of cortisol in a single fish. The PBS reconstitution method failed the precision recovery of serial dilutions (62.3%), linearity (R ²: 0.7864), and parallelism validation tests. The VO volume-boosting method passed all validation tests [intra-assay coefficent of variation (%CV): 16.3 for ELISA and 5.9 for RIA; inter-assay %CV: 10.3; spiked recovery: 102.0%; dilution recovery: 93.0%; linearity R ²: 0.9435; log of serial dilutions was parallel] and provided enough extract for multiple assays from an individual baitfish. Based on these results, we conclude that the VO volume-boosting method presents a means for determining cortisol from individual baitfish using either RIA or ELISA assays.  相似文献   

Short-term competition between crop plants and soil microbes for inorganic N fertilizer     

Erich Inselsbacher  Nina Hinko-Najera Umana  Markus Gorfer  Katrin Ripka  Rebecca Hood-Novotny  Wolfgang Wanek 《Soil biology & biochemistry》2010,42(2):360-372

Agricultural systems that receive high amounts of inorganic nitrogen (N) fertilizer in the form of either ammonium (NH₄⁺), nitrate (NO₃⁻) or a combination thereof are expected to differ in soil N transformation rates and fates of NH₄⁺ and NO₃⁻. Using ¹⁵N tracer techniques this study examines how crop plants and soil microbes vary in their ability to take up and compete for fertilizer N on a short time scale (hours to days). Single plants of barley (Hordeum vulgare L. cv. Morex) were grown on two agricultural soils in microcosms which received either NH₄⁺, NO₃⁻ or NH₄NO₃. Within each fertilizer treatment traces of ¹⁵NH₄⁺ and ¹⁵NO₃⁻ were added separately. During 8 days of fertilization the fate of fertilizer ¹⁵N into plants, microbial biomass and inorganic soil N pools as well as changes in gross N transformation rates were investigated. One week after fertilization 45-80% of initially applied ¹⁵N was recovered in crop plants compared to only 1-10% in soil microbes, proving that plants were the strongest competitors for fertilizer N. In terms of N uptake soil microbes out-competed plants only during the first 4 h of N application independent of soil and fertilizer N form. Within one day microbial N uptake declined substantially, probably due to carbon limitation. In both soils, plants and soil microbes took up more NO₃⁻ than NH₄⁺ independent of initially applied N form. Surprisingly, no inhibitory effect of NH₄⁺ on the uptake and assimilation of nitrate in both, plants and microbes, was observed, probably because fast nitrification rates led to a swift depletion of the ammonium pool. Compared to plant and microbial NH₄⁺ uptake rates, gross nitrification rates were 3-75-fold higher, indicating that nitrifiers were the strongest competitors for NH₄⁺ in both soils. The rapid conversion of NH₄⁺ to NO₃⁻ and preferential use of NO₃⁻ by soil microbes suggest that in agricultural systems with high inorganic N fertilizer inputs the soil microbial community could adapt to high concentrations of NO₃⁻ and shift towards enhanced reliance on NO₃⁻ for their N supply.  相似文献   

Effects of Amylopectin/Amylose Starch Ratio on Growth, Body Composition and Glycemic Response of Sunshine Bass Morone chrysops × M. saxatilis     

Steven  Rawles Rebecca  Lochmann 《Journal of the World Aquaculture Society》2003,34(3):278-288

Manipulation of the ratio of amylopectin (α‐[1,4] and α‐[1,6] linked glucose) to amylose (α‐[1,41 linked glucose) starches in the carbohydrate fraction of the diet has been used to improve carbohydrate and lipid metabolism in mammalian models. A 10‐wk feeding trial was conducted to determine the effect of dietary amylopectin/amylose ratio on growth and composition of growth of advanced sunshine bass (Morone chrysops × M. saxatilis) fingerlings (60 g, initial weight). Fish were fed cold‐pelleted, semipurified, isonitrogenous (35% crude protein), isocaloric (3.6 kcaVg protein), isolipidic (5%) diets containing 25% carbohydrate. The carbohydrate fraction of the diets was composed of either glucose, dextrin, 100% amylopectin/0% amylose, 70% amylopectin/30% amylose, or 30% amylopectin/70% amylose. Diets differing in ratios of amylopectin/amylose were achieved by adjusting the proportion of high‐amylopectin (100% amylopectin) to high‐amylose (70% amylose) corn starch. Diets were fed to fish in quadruplicate 76‐L tanks (seven fish/tank) connected to a brackish water (5‐7%v) recirculating culture system with biofiltration. Weight gain ranged from 195 to 236% of initial weight (60 g) and was significantly greater (P < 0.1) for fish fed diets containing 25% carbohydrate as dextrin or as 70% amylose and significantly lower in fish fed diets in which carbohydrate was composed of 30% amylose, 100% amylopectin, or glucose. Feed efficiency ranged from 0.52 to 0.61 and was higher in fish fed the diet containing the highest concentration of amylose and lower in fish fed the diet containing glucose. Hepatosomatic index was highest (2.71) in fish fed the diet containing glucose and lowest (1.401.45) in fish fed diets containing high‐amylose cornstarch. Intraperitoneal fat ratio was distinctly lower in fish fed diets containing some amylose as compared to those fed diets without amylose. Liver lipid was significantly lower (4.8%) in fish fed the diet containing glucose and almost twice as high (7.3‐8.9%) in fish fed the diets containing any starch. Glycogen content of the liver decreased from approximately 12% in fish fed the diet containing glucose to 5% in fish fed the diets containing amylose. Muscle proximate composition and ratio were unaffected by the dietary treatments. Fasting levels (15 h) of blood glucose in fish reared for 10 wk on the diet containing glucose were significantly elevated (5.5 mmol/L) when compared to fasting levels of those that had been reared on diets containing starch (3.4‐1.1 mmol/L). Fish fed the diet containing glucose exhibited maximum blood concentrations (14.6 mmoVL) 4 h postprandial then rapidly declined to nearly fasting levels within 8 h postprandial. In contrast, maximum plasma glucose concentrations in fish fed diets containing starch were roughly half (6.8‐8.1 mmol/L) those of fish fed the diet containing glucose. Blood glucose in fish fed diets containing dextrin or predominantly amylopectin starch remained elevated longer than that of fish fed diets containing glucose or predominantly amylose starch. Glycemic response appeared to decrease with increasing dietary amylose content. These data suggest that feeding diets in which a greater portion of the starch is amylose may be a useful strategy for improving carbohydrate use in sunshine bass.  相似文献   

Massive Hepatic Necrosis and Nodular Regeneration in Largemouth Bass Fed Diets High in Available Carbohydrate     

Andrew E.  Goodwin  Rebecca T.  Lochmann Darlene M.  Tieman Andrew J.  Mitchell 《Journal of the World Aquaculture Society》2002,33(4):466-477

Largemouth bass Micropterus salmoides are piscivorous fish raised on farms then sold live in Asian fish markets on the east and west coasts of the United States. In the winter of 1998, a major producer of feed‐trained bass suffered a significant increase in fish mortality both during shipping and while the fish were still in ponds. No bacterial, viral, or significant parasitic pathogens were found at necropsy. Livers of affected fish were pale and translucent with 3–10 mm pink nodules on their surface and deeper in the parenchyma. Histological examination of these livers showed that the translucent regions of the liver contained few hepatocytes and were composed of tissue consistent with a chronic inflammatory response. Also present were eosinophils, islands of pancreatic and biliary cells, and granulomas that did not stain positively for mycobacteria. The pink nodules were areas of multifocal regeneration of normal hepatocytes. Sequential studies of bass in ponds revealed that the bass were progressively accumulating glycogen in their hepatocytes to an extent sufficient to explain the massive necrosis of that organ. In order to determine the effect of diets varying in available carbohydrate on fish growth, survival, and liver glycogen content, a 12‐wk feeding trial was conducted in aquaria with juvenile largemouth bass. Nitrogen‐free extract values indicated that an extruded trout diet, a steelhead trout diet, and a diet designed to contain 45% protein and 25% fat, contained 35, 27, and 21% carbohydrate, respectively. Weight gain was lowest in fish fed the extruded trout diet, while liver glycogen was significantly higher in fish fed diets with >27% carbohydrate than in fish fed the diet with 21% carbohydrate. The farmer switched to a diet similar to the 45–25 diet used in our trial. Subsequently, 16‐mo‐old fish examined in October 2000 had no hepatic nodules or necrosis, were significantly larger and less variable in size than previous crops, and the farmer experienced no significant losses in ponds or during shipping.  相似文献   

Nutritional support in critical care patients.   总被引：3，自引：0，他引：3  

Rebecca L Remillard 《Veterinary Clinics of North America: Small Animal Practice》2002,32(5):1145-64, viii

Malnutrition in the form of insufficient nutrient intake to support tissue metabolism undermines appropriate medical or surgical therapeutic management of a case. The major consequences of malnutrition in all patients are decreased immunocompetence, decreased tissue synthesis and repair, and altered intermediary drug metabolism. A practical goal is to begin nutritional support within 24 hours of the injury, illness, or presentation. There are only two methods by which nutrients can be supplied to the body: enteral and parenteral. General guidelines are presented to help establish a foundation.  相似文献