Aldo-keto reductase may contribute to glyphosate resistance in Lolium rigidum     

Feng-Yan Zhou  Heping Han  Yun-Jing Han  Alex Nyporko  Qin Yu  Hugh J. Beckie  Stephen B. Powles 《Pest management science》2023,79(4):1528-1537

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Changes in fetal mannose and other carbohydrates induced by a maternal insulin infusion in pregnant sheep     

Laura D Brown  Stephanie R Thorn  Alex Cheung  Jinny R Lavezzi  Frederick C Battaglia  Paul J Rozance 《畜牧与生物技术杂志(英文版)》2015,(2):222-229

Background: The importance of non-glucose carbohydrates, especially mannose and inositol, for normal development is increasingly recognized. Whether pregnancies complicated by abnormal glucose transfer to the fetus also affect the regulation of non-glucose carbohydrates is unknown. In pregnant sheep, maternal insulin infusions were used to reduce glucose supply to the fetus for both short(2-wk) and long(8-wk) durations to test the hypothesis that a maternal insulin infusion would suppress fetal mannose and inositol concentrations. We also used direct fetal insulin infusions(1-wk hyperinsulinemic-isoglycemic clamp) to determine the relative importance of fetal glucose and insulin for regulating non-glucose carbohydrates.Results: A maternal insulin infusion resulted in lower maternal(50%, P < 0.01) and fetal(35-45%, P < 0.01) mannose concentrations, which were highly correlated(r2= 0.69, P < 0.01). A fetal insulin infusion resulted in a 50% reduction of fetal mannose(P < 0.05). Neither maternal nor fetal plasma inositol changed with exogenous insulin infusions.Additionally, maternal insulin infusion resulted in lower fetal sorbitol and fructose(P < 0.01).Conclusions: Chronically decreased glucose supply to the fetus as well as fetal hyperinsulinemia both reduce fetal non-glucose carbohydrates. Given the role of these carbohydrates in protein glycosylation and lipid production, more research on their metabolism in pregnancies complicated by abnormal glucose metabolism is clearly warranted.  相似文献   

Barley viability during storage: use of magnetic resonance as a potential tool to study viability loss     

Gruwel ML  Yin XS  Edney MJ  Schroeder SW  MacGregor AW  Abrams S 《Journal of agricultural and food chemistry》2002,50(4):667-676

Malting-quality barley samples of the varieties Harrington, Manley, and TR118, each from two locations in Saskatchewan, were collected directly from the producers and sent to China for storage. At regular intervals samples were shipped back to Canada for analysis consisting of germination studies, alpha-amylase tests, magnetic resonance imaging (MRI), and magnetic relaxation (NMR) studies. Samples showing a decrease in germinative energy and elevated levels of alpha-amylase also showed a rapid uptake of water in the area between the embryo and the endosperm as observed by MRI. Using NMR relaxation experiments, viable and nonviable barley samples could be distinguished after 2 h of imbibition.  相似文献   

Temperature, water content and wet-dry cycle effects on DOC production and carbon mineralization in agricultural peat soils     

Alex T. Chow  Kenneth K. Tanji  Randy A. Dahlgren 《Soil biology & biochemistry》2006,38(3):477-488

Agricultural peat soils in the Sacramento-San Joaquin Delta, California have been identified as an important source of dissolved organic carbon (DOC) and trihalomethane precursors in waters exported for drinking. The objectives of this study were to examine the primary sources of DOC from soil profiles (surface vs. subsurface), factors (temperature, soil water content and wet-dry cycles) controlling DOC production, and the relationship between C mineralization and DOC concentration in cultivated peat soils. Surface and subsurface peat soils were incubated for 60 d under a range of temperature (10, 20, and 30 °C) and soil water contents (0.3-10.0 g-water g-soil⁻¹). Both CO₂-C and DOC were monitored during the incubation period. Results showed that significant amount of DOC was produced only in the surface soil under constantly flooded conditions or flooding/non-flooding cycles. The DOC production was independent of temperature and soil water content under non-flooded condition, although CO₂ evolution was highly correlated with these parameters. Aromatic carbon and hydrophobic acid contents in surface DOC were increased with wetter incubation treatments. In addition, positive linear correlations (r²=0.87) between CO₂-C mineralization rate and DOC concentration were observed in the surface soil, but negative linear correlations (r²=0.70) were observed in the subsurface soil. Results imply that mineralization of soil organic carbon by microbes prevailed in the subsurface soil. A conceptual model using a kinetic approach is proposed to describe the relationships between CO₂-C mineralization rate and DOC concentration in these soils.  相似文献   

Pharmacokinetics of intravenous tramadol in dogs          下载免费PDF全文

Chantal J McMillan  Alex Livingston  Chris R Clark  Patricia M Dowling  Susan M Taylor  Tanya Duke  Rolf Terlinden 《Canadian journal of veterinary research》2008,72(4):325-331

The purpose of this study was to determine the pharmacokinetics of tramadol and the active metabolite mono-O-desmethyltramadol (M1) in 6 healthy male mixed breed dogs following intravenous injection of tramadol at 3 different dose levels. Verification of the metabolism to the active metabolite M1, to which most of the analgesic activity of this agent is attributed to, was a primary goal. Quantification of the parent compound and the M1 metabolite was performed using gas chromatography. Pharmacodynamic evaluations were performed at the time of patient sampling and included assessment of sedation, and evaluation for depression of heart and respiratory rates. This study confirmed that while these dogs were able to produce the active M1 metabolite following intravenous administration of tramadol, the M1 concentrations were lower than previously reported in research beagles. Adverse effects were minimal, with mild dose-related sedation in all dogs and nausea in 1 dog. Analgesia was not documented with the method of assessment used in this study. Tramadol may be useful in canine patients, but additional studies in the canine population are required to more accurately determine the effective clinical use of the drug in dogs and quantification of M1 concentrations in a wider population of patients.  相似文献   

副猪嗜血杆菌感染诊断方法和最新基因分型方法的研究进展   总被引：1，自引：0，他引：1  

Alex Olvera  Joaquim Segales  李艳  刘静  吴移鼎 《国外畜牧学(猪与禽)》2008,28(5)

副猪嗜血杆菌可引起猪格拉塞病和其它许多疾病,对与该茵有关的疾病进行诊断通常依赖于临床症状、病理变化和细菌分离,但由于有无毒菌株(nonvirulent strain)的存在及其在健康仔猪上呼吸道上的早期定殖,使得对该菌的诊断变得较为复杂.而且,在同一猪场甚至是同一只猪体内可能存在多种不同的菌株,因此确定可导致临床发病的特定菌株显得尤为重要.最近,科研人员开发了一些针对副猪嗜血杆菌的基因分型方法,目的是确定该茵的基因型与其毒力强度之间的关系.由于缺乏副猪嗜血杆菌完整基因组序列及其致病因子(virulence factor)的知识,因此将副猪嗜血杆菌的基因型与其毒力联系起来极富挑战性.  相似文献   

Effects of Cylindrospermopsin Producing Cyanobacterium and Its Crude Extracts on a Benthic Green Alga—Competition or Allelopathy?     

Viktória B-Béres  Gábor Vasas  Dalma Dobronoki  Sándor Gonda  Sándor Alex Nagy  István Bácsi 《Marine drugs》2015,13(11):6703-6722

Cylindrospermopsin (CYN) is a toxic secondary metabolite produced by filamentous cyanobacteria which could work as an allelopathic substance, although its ecological role in cyanobacterial-algal assemblages is mostly unclear. The competition between the CYN-producing cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum, and the benthic green alga Chlorococcum sp. was investigated in mixed cultures, and the effects of CYN-containing cyanobacterial crude extract on Chlorococcum sp. were tested by treatments with crude extracts containing total cell debris, and with cell debris free crude extracts, modelling the collapse of a cyanobacterial water bloom. The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control). Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected. The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent. The presence of C. ovalisporum in mixed cultures did not cause significant differences in nutrient content compared to Chlorococcum control culture, so the growth inhibition of the green alga could be linked to the presence of CYN and/or other bioactive compounds.  相似文献   

Genetic variability of pure <Emphasis Type="Italic">Pseudoplatystoma corruscans</Emphasis> and <Emphasis Type="Italic">Pseudoplatystoma reticulatum</Emphasis> individuals in the Paraná and Paraguay River basins     

Jussara Oliveira Vaini  Bruno do Amaral Crispim  Danielly Beraldo dos Santos Silva  Celso Benites  Marcia Regina Russo  Alexéia Barufatti Grisolia 《Fisheries Science》2016,82(4):605-611

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Community Changes and Growth in Small Cities: Resident Perceptions of Growth in Brandon,Manitoba, Canada          下载免费PDF全文

Doug Ramsey  Alex Michalos  Derrek Eberts 《Growth and change》2016,47(4):682-699

While research on rural depopulation and urbanization to large cities has dominated the literature for decades, small city growth has been largely ignored. Yet, small cities are important to the regional systems in which they are located, including serving as centres to their rural surround. This paper is concerned about growth and change in small cities. Using Brandon, Manitoba as an example, citizen perceptions of a range of specific aspects of city growth are analyzed. The study is based on a household postal survey conducted in May and June 2010 in which 2,500 randomly selected households in Brandon, Manitoba received questionnaires. The results are based on the 518 useable, completed questionnaires that were returned. Differences in perceptions of the pace of change in a range of aspects of development were found based on income, age, educational attainment, employment status, and home ownership. No differences were found based on gender. The paper concludes with comments about how city governments need to be aware of citizen perceptions when pursuing and managing development. The paper also illustrated the importance of citizen perceptions in understanding the pace and direction of change in small cities.  相似文献   

New insights regarding gonad development in European eel: evidence for a direct ovarian differentiation     

Benjamin Geffroy  Yann Guiguen  Alexis Fostier  Agnès Bardonnet 《Fish physiology and biochemistry》2013,39(5):1129-1140

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