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Fire products have been widely identified as germination cues for a number of species from both fire-prone and fire-free ecosystems. However, there is uncertainty about the effects of fire products on seed germination of semi-arid rangeland species. We examined the germination of seven dominant species from Central Zagros rangelands in the semi-arid region of Iran under various heat shock (60, 80 and 120 °C), aerosol smoke, ash and control treatments. Our findings showed that fire products could enhance, inhibit or not affect the seed germination of rangeland species in this area. The germination percentage of Astragalus adscendens increased following 60 °C heat treatment in comparison with the control. The germination of Astragalus verus, Bromus tectorum, B. tomentellus and Phlomis olivieri were increased significantly using smoke treatment (P<0.0001). The seed germination of B. tomentellus and B. tectorum was promoted by ash treatment, whereas the other species exhibited no response or were inhibited by fire products. In addition, smoke treatment shortened the overall germination time of B. tectorum. These findings suggest that fire products affect the germination of several species and can serve as potential tools for understanding the vegetation dynamics and restoration of disturbed semi-arid rangelands.  相似文献   
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This study was conducted to investigate the effects of probiotic (Primalac), prebiotic (TechnoMos) and synbiotic (Primalac + TechnoMos) supplementation on performance, immune responses, intestinal morphology and bacterial populations of ileum in broilers. A total of 240 one‐day‐old broiler chicks were randomly divided into four treatment groups which included 60 birds. Control group did not receive any treatment. The chicks in the second, third and fourth groups were fed probiotic (0.9 g/kg), prebiotic (0.9 g/kg) and probiotic (0.9 g/kg) plus probiotic (0.9 g/kg; synbiotic), respectively, at entire period. Daily feed intake, daily weight gain and feed conversion ratio were evaluated. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody titres were measured on days 28, 35 and 42. Newcastle vaccines administered on days 9, 18 and 27 to chicks and blood samples were collected on day 42. Intestinal morphometric assessment and enumeration of intestinal bacterial populations were performed on day 42. The results indicated that consumption of probiotic, prebiotic and synbiotic had no significant effect on daily feed intake, daily body weight gain, feed conversion ratio, carcass traits, intestinal morphology and bacterial populations of ileum (p > 0.05). Consumption of prebiotic increased total and IgM anti‐SRBC titres on days 28 and 42 and antibody titre against Newcastle virus disease on day 42 (p < 0.05). Synbiotic increased only total anti‐SRBC on day 28 (p < 0.05). It is concluded that consumption of prebiotic increased humoral immunity in broilers. Therefore, supplementation of diet with prebiotic for improvement of humoral immune responses is superior to synbiotic supplementation.  相似文献   
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Leptin, a pleiotropic hormone regulating food intake and energy expenditure, has been shown to directly modulate human polymorphonuclear neutrophil (PMN) functions or indirectly through the action of tumor necrosis factor-alpha (TNF-alpha). Bovine PMN have considerable different characteristics from human PMN. For example, it does not respond to N-formyl-Methionyl-Leucyl-phenylalanine, a well known human PMN activator. In the present study, we tested the effects of leptin and TNF-alpha on superoxide production and degranulation of bovine peripheral PMN, in which both long isoform of leptin receptor (Ob-Rb) and TNF receptor 1 were expressed. Human leptin, human TNF-alpha, phorbol myristate acetate (PMA) and opsonized zymosan particles (OZP) did not stimulate degranulation responses, while zymosan-activated serum (ZAS) did. Neither leptin nor TNF-alpha enhanced the ZAS-induced degranulation responses. TNF-alpha, PMA, OZP and ZAS increased superoxide production in different magnitudes, whereas leptin did not. TNF-alpha, but not leptin, enhanced OZP- and ZAS-induced superoxide production, possibly, in part due to facilitating translocation of p47(phox), a component of NADPH oxidase. These results indicate that, unlike in human PMN, leptin does not have any direct effect on degranulation and superoxide production in bovine PMN, although TNF-alpha influences superoxide production.  相似文献   
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<正>普通菜豆(Common bean),俗称芸豆(Kidney bean),为豆科(Fabaceae)菜豆属一年生草本植物,营养丰富,蛋白质含量高,既是蔬菜又是粮食,是重要的农副产品。内蒙古自治区是我国种植普通菜豆的主要地区之一。随着普通菜豆栽培面积以及连作年限不断增加,病虫害问题日益突出,尤其是枯萎病,严重影响了普通菜豆的产量和品质,已成为限制普通菜豆产业可持续发展的主要因素之一。2021年7月,  相似文献   
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This paper designed and developed a multi-objective programming (MOP) model to illustrate the dynamic relationship among technologies, productive activities, constraints and farmers’ objectives in the peri-urban vegetable production system and use the model as an economic tool in analysing probable consequences of a given action or innovation on the farm. The best compromise solution was generated using four analytical steps, as follows: single-objective optimization (to determine the ideal and anti-ideal values of the objective functions); constrained optimization (to generate the set of Pareto non-dominated solutions); cluster analysis (to trim down efficient set into smaller homogeneous groups); and compromise programming (to determine where the best compromise solution lies).  相似文献   
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