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101.
102.
Balsevich JJ Ramirez-Erosa I Hickie RA Dunlop DM Bishop GG Deibert LK 《Fitoterapia》2012,83(1):170-181
Total methanolic extracts of Saponaria vaccaria seed derived from several varieties, as well as various purified components obtained through successive chromatographic separations of total extracts were evaluated for their growth inhibitory activity in WiDr (colon), MDA-MB-231 (breast), NCI-417 (lung) and PC-3 (prostate) human cancer cells as well as the non-tumorigenic fibroblast BJ (CRL-2522) cell line using MTT colorimetric assay. Purified bisdesmosidic saponins segetoside H and I were further examined using microscopy and apoptosis assays. Bisdesmosidic saponins exhibited dose-dependent growth inhibitory and selective apoptosis-inducing activity. Growth inhibitory effects were particularly strong in a breast (MDA-MB-231) and a prostate (PC-3) cancer cell line. Total extracts exhibited a different preference being most active against a colon cancer cell line (WiDr). In a comparison of varieties, all of the total seed extracts exhibited similar dose-dependent activities, but with some variation in potency. Monodesmosidic saponins vaccarosides A and B, phenolic vaccarin, and cyclopeptide segetalin A, co-occurring seed substituents, did not exhibit activity. The non-tumorigenic fibroblast cell line BJ (CRL 2522) was growth inhibited but did not undergo apoptosis when treated with bisdesmosidic saponins at low micromolar concentrations. Saponin-rich extracts from Kochia scoparia seed and Chenopodium quinoa were also evaluated alongside Saponaria saponins but did not exhibit activity. Closely related Quillaja saponins exhibited activity but were less potent. 相似文献
103.
Relationships among milk urea-nitrogen, dietary parameters, and fecal nitrogen in commercial dairy herds 下载免费PDF全文
Pipat Arunvipas John A. VanLeeuwen Ian R. Dohoo Greg P. Keefe Shelley A. Burton Kerry D. Lissemore 《Canadian journal of veterinary research》2008,72(5):449-453
Our study objective was to determine the ability of milk urea-nitrogen concentrations ([MUN]) to predict fecal nitrogen concentrations ([Fecal N]) in commercial dairy herds. A total of 83 dairy herds were each visited 3 times within 48 h after a monthly herd milk test. For each farm visit, forages were sampled for nutrient analyses, which were entered into a computerized ration evaluator, and fecal samples were taken per rectum from each of 6 cows (2 early-, 2 mid-, and 2 late-lactation). Fecal samples were pooled, mixed, and analyzed for nitrogen content. Fecal nitrogen concentrations were compared with the routinely measured nutritional parameters from the ration evaluation, and the herd average [MUN] for the previous milk test date using mixed linear regression analyses. Total protein supplied in the ration was significantly positively associated with [Fecal N], but herd average [MUN] was not associated (P > 0.10) with [Fecal N]. 相似文献
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Jitender Bhandal Alan Kuzma Greg Starrak 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(10):1002-1004
The abdominal ultrasonogram of a dog admitted for acute onset of collapse revealed an abnormally displaced left medial liver lobe with no blood flow. Surgical and histological findings confirmed the ultrasonographic diagnosis of left liver lobe torsion. Ultrasonographic findings were useful and probably sufficient for a correct diagnosis. 相似文献
106.
Booker CW Abutarbush SM Morley PS Guichon PT Wildman BK Jim GK Schunicht OC Pittman TJ Perrett T Ellis JA Appleyard G Haines DM 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(3):253-260
The aim of this study was to investigate the effect of bovine viral diarrhea virus (BVDV) infections (unapparent acute infections and persistent infections) on the overall health and performance of feedlot cattle. Calves from 25 pens (7132 calves) were enrolled in the study. Overall and infectious disease mortality rates were significantly higher (P < 0.05) in pens categorized at arrival as positive for type I BVDV and lower in pens that were positive for type II BVDV than in negative pens. Mortality attributed to BVDV infection or enteritis was significantly more common (P < 0.05) in the pens containing persistently infected (PI) calves than in pens not containing PI calves (non-PI pens). There were no statistically detectable (P > or = 0.05) differences in morbidity, overall mortality, average daily gain, or the dry matter intake to gain ratio between PI and non-PI pens. Although type-I BVDV infections in feedlots appear to contribute to higher mortality rates, the presence of PI calves alone does not appear to have a strong impact on pen-level animal health and feedlot performance. 相似文献
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Physically based equations for unsaturated groundwater flow and solute transport have been coupled with kinetic rate laws for mineral dissolution–precipitation, and mass balance/mass action equations for aqueous species, in a numerical model that is capable of simulating rock–water interactions in a weathering profile subjected to fluctuating boundary conditions. A numerical experiment was conducted to demonstrate how incipient soil development may proceed in a warm subhumid environment. The simulation involved a hypothetical coarse-textured parent material that was subjected to frequent wetting and drying during an annual water cycle. The hypothetical weathering profile evolved rapidly; dissolution of primary minerals (enstatite, forsterite, and diopside) and precipitation of secondary clay–minerals (kaolinite and Ca-montmorillonite) occurred monotonically despite the abrupt fluctuations in soil-moisture content. In contrast, the activities of aqueous species and dissolution–precipitation rates of calcite were very sensitive to the changing moisture conditions in the upper part of the profile. Although the simulation involved numerous simplifying assumptions, reasonable results were achieved and the calculated (from the model) rate of chemical denudation fell within the range of contemporary denudation rates determined from the dissolved loads of rivers. 相似文献
110.
Reproductive resilience: a paradigm shift in understanding spawner‐recruit systems in exploited marine fish 下载免费PDF全文
Susan Lowerre‐Barbieri Greg DeCelles Pierre Pepin Ignacio A Catalán Barbara Muhling Brad Erisman Steven X Cadrin Josep Alós Andres Ospina‐Alvarez Megan M Stachura Michael D Tringali Sarah Walters Burnsed Claire B Paris 《Fish and Fisheries》2017,18(2):285-312
A close relationship between adult abundance and stock productivity may not exist for many marine fish stocks, resulting in concern that the management goal of maximum sustainable yield is either inefficient or risky. Although reproductive success is tightly coupled with adult abundance and fecundity in many terrestrial animals, in exploited marine fish where and when fish spawn and consequent dispersal dynamics may have a greater impact. Here, we propose an eco‐evolutionary perspective, reproductive resilience, to understand connectivity and productivity in marine fish. Reproductive resilience is the capacity of a population to maintain the reproductive success needed to result in long‐term population stability despite disturbances. A stock's reproductive resilience is driven by the underlying traits in its spawner‐recruit system, selected for over evolutionary timescales, and the ecological context within which it is operating. Spawner‐recruit systems are species specific, have both density‐dependent and fitness feedback loops and are made up of fixed, behavioural and ecologically variable traits. They operate over multiple temporal, spatial and biological scales, with trait diversity affecting reproductive resilience at both the population and individual (i.e. portfolio) scales. Models of spawner‐recruit systems fall within three categories: (i) two‐dimensional models (i.e. spawner and recruit); (ii) process‐based biophysical dispersal models which integrate physical and environmental processes into understanding recruitment; and (iii) complex spatially explicit integrated life cycle models. We review these models and their underlying assumptions about reproductive success vs. our emerging mechanistic understanding. We conclude with practical guidelines for integrating reproductive resilience into assessments of population connectivity and stock productivity. 相似文献