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1.
Comparative functional responses (FRs) can predict impacts of invasive species, including piscivorous fishes, via quantifying their depletion of native food resources as a function of prey density. The utility of FRs for predicting impacts on prey populations by invasive fishes of different trophic guilds was tested here by comparing the FRs of the invaders Cyprinus carpio and Carassius auratus, with three native, trophically analogous fishes, Barbus barbus, Squalius cephalus and Tinca tinca. Chironomid larvae and Gammarus pulex were used as prey items. Predictions, developed from studies on the foraging of C. carpio and C. auratus in the literature, were that the invaders would have significantly higher consumption rates for chironomids than the native fishes, but not for G. pulex. Mean consumption rates for chironomids were significantly lower for both invaders than B. barbus and S. cephalus, but were similar to T. tinca. Barbus barbus had a significantly lower consumption rate of G. pulex than both invaders, but there were no significant differences between S. cephalus, T. tinca and the invaders. All FRs were type II, with FR curves for the invaders preying upon chironomids never being significantly higher than the native fishes, contrary to predictions. For G. pulex, some significant differences were apparent between the invaders and native fishes, but again were contrary to predictions. These results indicated that when predation impacts of invasive fishes could also be a function of their population density and body sizes, these parameters should be incorporated into FR models to improve impact predictions.  相似文献   
2.
Type II innate lymphoid cells (ILC2s) are widely distributed in the blood, intestines, trachea, lung, spleen, liver, animal fat and skin, and involved in the innate immune responses. ILC2s have attracted much attention for its important roles in the conversion of white adipose to beige adipose. Studies have shown that ILC2s are essential for the proliferation and differentiation of adipocyte precursor cells, and they also play a vital role in anti-parasitic infection and allergic inflammation. This review discusses the discovery, differentiation, development, distribution and function of ILC2s, and their relationships with the browning of white adipose tissue for providing valuable references on understanding the pathogenesis, prevention and treatment of obesity and fat metabolism disorders.  相似文献   
3.
Thermotolerance acclimation of photosystem II to heat and drought is well documented, but studies demonstrating developmental impacts on heat tolerance in field‐grown plants are limited. Consequently, climatic variables, estimated canopy temperature, predawn leaf water potential (ΨPD), and the temperature responses of maximum quantum yield of photosystem II (Fv/Fm), variable fluorescence (Fv/F0), quantum yield of electron transport (φEο) and efficiency of PSI electron acceptor reduction (REο/ABS) were characterized for Gossypium hirsutum at three sample times during the growing season (21 June, 2 July and 18 July 2013) under well‐watered conditions. The temperature decreasing a given photosynthetic parameter 15% from the optimum is referred to as T15 and served as a standardized measure of heat tolerance. Ambient and estimated canopy temperatures were well within the optimal range for cotton throughout the sample period, and leaves were verified well watered using ΨPD measurements. However, T15 varied with sample date (highest on July 2 for all parameters), being 2 °C (Fv/F0) to 5.5 °C (φEο) higher on July 2 relative to June 21, despite optimal temperature conditions and predawn leaf water potential on all sample dates. These findings suggest that even under optimum temperature conditions and water availability, heat tolerance could be influenced by plant developmental stage.  相似文献   
4.
In this issue, the unusual clinical presentation of a horse diagnosed is described with severe liver cirrhosis and hepatic encephalopathy. The horse initially presented for thoracic and pelvic limb ataxia and weakness, and signs of forebrain disease were not apparent until later in the disease process. The typical pathology of central nervous system disease associated with liver disease is related to encephalopathy and forebrain disease; however, the spinal cord is occasionally also involved. Hepatic myelopathy is a rare syndrome usually associated with surgical or acquired portosystemic shunts, liver cirrhosis and/or portal hypertension in man. Where a gliopathy is the most prominent pathological feature seen in hepatic encephalopathy, in hepatic myelopathy the most remarkable feature is demyelination of the corticospinal tracts of the distal cervical and thoracic spinal cord with occasional axon loss. The clinical signs of hepatic myelopathy are spastic paresis/paralysis with normal sensory findings and preserved sphincter function. The prognosis for hepatic myelopathy is generally poor. In summary, in severe liver disease, motor deficits can occur secondary to the encephalopathy, but motor deficits can also occur as a result of spinal cord pathology such as seen in hepatic myelopathy. In examination of horses with myelopathies, liver disease as a cause of myelopathy should be included in our list of differentials.  相似文献   
5.
AIM: To investigate the levels of neuropeptides and electrolytes in the patients with acute traumatic brain injury.METHODS: Seventy-eight patients with acute brain injury were divided into mild, moderate and severe groups according to their GCS scores. The serum levels of arginine vasopressin (AVP) and angiotensin II (Ang II) were measured on day 1, 3 and 7 after injury. The serum levels of electrolytes were also measured on day 1. Forty-one subjects who received healthy check-up served as normalcontrols. RESULTS: Compared with normal control group, the serum levels of AVP and Ang II significantly increased in the patients with traumatic brain injury (P<0.01), depending on the severity of brain injury. Both neuropeptides reached the peak on day 3 after injury. The concentrations of serum potassium and calcium decreased in the patients with acute brain injury(P<0.01),also showing a severity-dependent tendency. No significant change of serum sodium in the patients with brain injury was observed. CONCLUSION: The serum levels of arginine vasopressin and angiotensin II canalso be used as the severity indicators of traumatic brain injuries. Decrease in serum potassium and calcium can also be used to evaluate the severity in patients with acute traumatic brain injury.  相似文献   
6.
7.
A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0 mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution, Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %.  相似文献   
8.
Mulch is considered a desirable management technology for conserving soil moisture, improving soil temperature and soil quality. This study aimed to investigate soil conditions and hot pepper (Capsicum annuum L.) performance in terms of leaf photosynthetic capacity, fruit yield and quality, and irrigation water use efficiency (IWUE) under such practices in greenhouse condition. A field experiment across 3 years was carried out with four types of mulch (without mulch [CK], wheat straw mulch [SM], plastic film mulch [FM], and combined mulch with plastic film and wheat straw [CM]). Mulch could improve soil physical properties regardless of mulch materials. FM and CM treatments improved soil moistures status and soil temperature in comparison to CK control, while SM increased soil water content and decreased soil temperature. Mulch increased leaf net photosynthesis rate (PN), stomatal conductance to water vapor (gs), intercellular CO2 concentration (Ci), and transpiration rate (E), but declined instant water use efficiency (WUEi). No significant effect of mulch application on chlorophyll fluorescence was existent for the entire growth season. Fruit yield and irrigation water use efficiency (IWUE) showed some increment under all the mulch conditions. Compared to CK, the yield was enhanced by 82.3%, 65.0%, and 111.5% in 2008; 38.1%, 17.4%, and 46.5% in 2009; and 14.3%, 6.5%, and 19.6% in 2010 under SM, FM, and CM conditions, respectively. Although FM produced better fruit quality than other treatments, CM is the recommended practice for hot pepper cultivation in greenhouse condition due to working well to facilitate soil condition (moisture and temperature), plant growth, and marketable yield.  相似文献   
9.
为满足口岸对南非II型口蹄疫检测、监测的需求,在对南非II型口蹄疫抗原表位分析及相关基因合成的基础上,进行融合蛋白pGEX—VP1-VP3的体外表达,采用柱上酶切方法制备VP1-VP3蛋白。将纯化VP1-VP3抗原包被96微孔板,分别优化抗原包被浓度、血清稀释度、酶标二抗稀释度,确定阴性临界值。经反复优化,建立的南非II型间接ELISA检测方法的最佳抗原包被浓度为6.4ug/ml,血清最佳稀释度为1:200,酶标二抗最佳稀释度为1:4000,阴性临界值(0D450)为0.562。检测样品判定标准为:OD450〉0.622为阳性,OD450〈0.502为阴性,0.502≤OD450≤0.622为可疑。特异性试验结果表明,所建立方法与其它血清型口蹄疫间无交叉反应。南非II型口蹄疫间接ELISA检测方法的建立为我国口岸口蹄疫检疫提供了新的查验方法。  相似文献   
10.
基于铜,邻二氮菲和溴酚兰形成Cu:phen:BPB为1:3:1的三元配合物且丁基罗丹明B与溴酚兰形成经BPB:BRB为1:3的等色染料离子对,建立了等色染出子对萃取法测Cu的新方法,该法摩尔吸光系数为2.86×10^5L.mol^-1.cm^-1线性9.44×10^-7-8.65×10^-5mol.L^-1。  相似文献   
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