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91.
Kristen A. DaVanon Lindsey K. Howard Karen E. Mabry Robert L. Schooley Brandon T. Bestelmeyer 《Landscape Ecology》2016,31(10):2343-2354
Context
Mechanisms of ecosystem change in urbanizing landscapes are poorly understood, especially in exurban areas featuring residential or commercial development set in a matrix of modified and natural vegetation. We asked how development altered trophic interactions and ecosystem processes in the matrix.Objectives
We examined the effect of varying degrees of exurban development (housing density) on a trophic system that included an apex mammalian predator (coyote, Canis latrans), mammalian herbivores (lagomorphs and rodents), and herbaceous plants. We tested the hypothesis that plant recruitment would be negatively affected by exurban development due either to increases in herbivores associated with increased resource availability (a bottom–up effect) or to a reduction in predators that avoid humans (a top–down effect).Methods
In Las Cruces, New Mexico, USA, four replicate sites were located in each of three urbanization levels: high density exurban, low density exurban, and wildland dominated by Chihuahuan Desert vegetation. Seedling trays measured herbivory rates, live trapping estimated abundance of pocket mice and kangaroo rats, and remotely-triggered wildlife cameras estimated the activity of lagomorphs and coyotes.Results
Increased herbivory on seedlings and decreased herbaceous plant recruitment were observed in high density exurban areas. Overall rodent abundance, seed consumption rates, and activity of the lagomorph Lepus californicus did not vary with urbanization level. Activity by another lagomorph, Sylvilagus audubonii, and coyotes was highest in dense exurban areas, consistent with a bottom–up effect.Conclusions
Exurban development can have important indirect effects on trophic interactions occurring in adjacent, untransformed ecosystems. Similar to earlier studies, such effects in the Chihuahuan Desert may be mediated by bottom–up processes associated with anthropogenic inputs.92.
Ayako Oda Kristen M. Messenger Liliana Carbajal Lysa P. Posner Brett R. Gardner Scott H. Hammer Anthony J. Cerreta Gregory A. Lewbart Kate M. Bailey 《Veterinary anaesthesia and analgesia》2018,45(4):529-538
Objective
To test the hypothesis that plasma propofol concentration (PPC) is associated with anesthetic effect in koi carp administered propofol by immersion.Study design
Prospective study.Animals
Twenty mature koi carp (mean ± standard deviation, 409.4 ± 83.7 g).Methods
Fish were immersed in propofol (5 mg L–1). Physiological variables and induction and recovery times were recorded. In phase I, blood was sampled for PPC immediately following induction and at recovery. In phase II, following induction, fish were maintained with propofol (4 mg L–1) via a recirculating system for 20 minutes. Following established induction, blood was sampled at 1, 10 and 20 minutes. In phase III (n = 19), fish were anesthetized as in phase II with blood sampled nine times in a sparse sampling strategy. Simultaneously, a pharmacodynamics rubric was used to evaluate anesthetic depth. PPC was determined using high performance liquid chromatography with fluorescence detection. Following evaluation of normality, data were analyzed using paired t test or Spearman correlation test (significance was set at p < 0.05).Results
In phase I, mean PPCs at induction (20.12 μg mL–1) and recovery (11.62 μg mL–1) were different (p < 0.001). In phase II, only mean PPCs at induction (17.92 μg mL–1) and 10 minutes (21.50 μg mL–1) were different (p = 0.013). In phase III, a correlation between PPCs and the pharmacodynamic rubric scores was found (p < 0.001, r = –0.93). There was no correlation between PPCs and recovery time (p = 0.057, r = 0.433). A two-compartment open model was chosen for the pharmacokinetic model. Absorption rate constant, elimination rate constant and intercompartmental rate constant were 0.48, 0.006 and 0.02 minute–1, respectively.Conclusions and clinical relevance
Measurable PPCs were achieved in koi carp anesthetized with propofol by immersion. Anesthetic depth of fish was negatively correlated with PPCs, but recovery time was not. 相似文献93.
Kristen M. Hart Margaret M. Lamont Ikuko Fujisaki Anton D. Tucker Raymond R. Carthy 《Biological conservation》2012,145(1):185-194
Designing conservation strategies that protect wide-ranging marine species is a significant challenge, but integrating regional telemetry datasets and synthesizing modeled movements and behavior offer promise for uncovering distinct at-sea areas that are important habitats for imperiled marine species. Movement paths of 10 satellite-tracked female loggerheads (Caretta caretta) from three separate subpopulations in the Gulf of Mexico, USA, revealed migration to discrete foraging sites in two common areas at-sea in 2008, 2009, and 2010. Foraging sites were 102–904 km away from nesting and tagging sites, and located off southwest Florida and the northern Yucatan Peninsula, Mexico. Within 3–35 days, turtles migrated to foraging sites where they all displayed high site fidelity over time. Core-use foraging areas were 13.0–335.2 km2 in size, in water <50 m deep, within a mean distance to nearest coastline of 58.5 km, and in areas of relatively high net primary productivity. The existence of shared regional foraging sites highlights an opportunity for marine conservation strategies to protect important at-sea habitats for these imperiled marine turtles, in both USA and international waters. Until now, knowledge of important at-sea foraging areas for adult loggerheads in the Gulf of Mexico has been limited. To better understand the spatial distribution of marine turtles that have complex life-histories, we propose further integration of disparate tracking data-sets at the oceanic scale along with modeling of movements to identify critical at-sea foraging habitats where individuals may be resident during non-nesting periods. 相似文献
94.
Kristen M. Weishaar Elijah F. Edmondson Douglas H. Thamm Christine S. Olver 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2014,43(3):447-452
A male castrated Golden Retriever was presented for evaluation of a large mass over the left shoulder extending to the lower part of the neck that had been present for an extended period of time, but had a recent history of rapid growth. Previous aspirates of the mass were consistent with a lipoma. The mass was surgically excised and was diagnosed as an extraskeletal osteosarcoma based on histopathology. After surgery, the dog was initiated on a chemotherapy protocol with carboplatin and metronomic cyclophosphamide. He became neutropenic, anemic, and thrombocytopenic 14 days after the carboplatin treatment was administered. The neutropenia resolved, but the anemia and thrombocytopenia progressed. A bone marrow aspirate revealed erythroid hypoplasia, myeloid hyperplasia with a predominance of early precursors, and a subset of cells that made up 20% of the total population that were reported as bizarre and unclassifiable. These cells were discrete in nature and were thought to be hematopoietic in origin. The dog was euthanized due to deterioration of the clinical condition. On postmortem examination, widespread metastasis involving the lungs, liver, kidney, heart, and bone marrow was found. Histopathology of the tumor lesions determined 2 distinct malignant populations of liposarcoma and osteosarcoma, consistent with malignant mesenchymoma. However, the possibility of 2 separate neoplastic processes cannot be definitively excluded. This is the first report of bone marrow metastasis of a malignant mesenchymoma in a dog. 相似文献
95.
The uptake of Cd and Zn by the earthworm Eisenia fetida was determined at varying Ca concentrations and with pre-exposure to different metabolic inhibitors in simulated soil solutions over a 48-h period. The presence of Ca in the solution had complex actions on Cd uptake. At a low Cd concentration of 0.1 μM, Ca (0.1-1 mM) slightly but significantly stimulated Cd uptake, whereas it inhibited Cd uptake at a higher Cd level (10 μM). Pre-exposure to a Ca-channel blocker (Lanthanum) inhibited Cd uptake over a relatively wide range of Cd concentrations, but not Zn uptake, suggesting that the uptake of Zn was not exerted at a Ca channel. N-ethylmaleimide, which specifically binds to sulfhydryl groups, inhibited Zn uptake at both 0.1 and 10 μM, implying that the transport of Zn is carrier-mediated by proteins or other SH-containing compounds. The present study provides evidence that the mechanisms of Cd and Zn uptake in earthworms are pharmacologically different, although both metals have similar geochemical and environmental properties. After 24 h pre-exposure to a sublethal concentration (1.0 μM) of Cd, Zn toxicity for E. fetida was significantly reduced with 48-h LC50 values (with 95% confidence interval) increasing from 145 (105-201) to 316 (212-470) μM Zn. Pre-exposure to Zn (1.0 μM) did not, however, affect Cd toxicity. Pre-exposure to Cd significantly changed the subcellular Zn distribution, with a decreasing fraction of Zn associated with Fraction B (associated with granules and cell membranes), which is believed to be most indicative of toxic pressure and an increased fraction associated with Fraction G (associated with cytosol). This most likely explains the observed Zn tolerance of E. fetida after low level Cd pre-exposure. These results help to understand the uptake mechanism and interactions of Zn and Cd in earthworms. 相似文献
96.
Zheng Q Song J Doncaster K Rowland E Byers DM 《Journal of agricultural and food chemistry》2007,55(5):1663-1673
A modified phenol-based protocol and a phenol-free protocol that involves hot SDS extraction followed by TCA precipitation in acetone were qualitatively and quantitatively compared and evaluated on apple peel and strawberry fruit. The phenol protocol resulted in significantly higher protein yields of 2.35 +/- 0.1 and 0.46 +/- 0.06 mg/g of FW from apple and strawberry fruit, respectively, compared to the SDS protocol, which produced 0.74 +/- 0.1 and 0.27 +/- 0.02 mg/g of FW, respectively. 2-DE analysis of apple protein extracts revealed 1422 protein spots associated with the phenol protocol and 849 spots associated with the SDS protocol. Of these, 761 were present only in phenol gels, whereas 23 were exclusive to SDS samples. For strawberry, SDS extraction produced poor-quality spots with a high degree of streaking, indicating possible contamination. The application of a cleanup procedure resulted in a purified protein extract with high-quality spots. 2-DE analysis of strawberry protein extracts revealed 1368 spots for the phenol protocol and 956 spots for the SDS protocol accompanied by the cleanup procedure. Of these, 599 spots were present only in phenol gels, whereas 109 were present only in SDS samples. Spots from each fruit tissue and extraction procedure were selected, and a total of 26 were identified by LC-MS/MS. Overall, this study demonstrates the complexity of protein extraction of fruit tissues and suggests that a phenol-based protein extraction protocol should be used as a standard procedure for recalcitrant fruit tissues, whereas a SDS protocol with or without a cleanup procedure may be used as an alternative protocol. 相似文献
97.
Anne Geffré Kristen Friedrichs Kendal Harr Didier Concordet Catherine Trumel Jean‐Pierre Braun 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2009,38(3):288-298
Abstract: Reference values are used to describe the dispersion of variables in healthy individuals. They are usually reported as population‐based reference intervals (RIs) comprising 95% of the healthy population. International recommendations state the preferred method as a priori nonparametric determination from at least 120 reference individuals, but acceptable alternative methods include transference or validation from previously established RIs. The most critical steps in the determination of reference values are the selection of reference individuals based on extensively documented inclusion and exclusion criteria and the use of quality‐controlled analytical procedures. When only small numbers of values are available, RIs can be estimated by new methods, but reference limits thus obtained may be highly imprecise. These recommendations are a challenge in veterinary clinical pathology, especially when only small numbers of reference individuals are available. 相似文献
98.
Kessler JD Kahle KT Sun T Meerbrey KL Schlabach MR Schmitt EM Skinner SO Xu Q Li MZ Hartman ZC Rao M Yu P Dominguez-Vidana R Liang AC Solimini NL Bernardi RJ Yu B Hsu T Golding I Luo J Osborne CK Creighton CJ Hilsenbeck SG Schiff R Shaw CA Elledge SJ Westbrook TF 《Science (New York, N.Y.)》2012,335(6066):348-353
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