Effects of two dietary probiotics (Bacillus subtilis or licheniformis) with two prebiotics (mannan or fructo oligosaccharide) in Japanese eel,Anguilla japonica     

Youngjin Park  Haham Kim  Seonghun Won  Ali Hamidoghli  Md Tawheed Hasan  In‐Soo Kong  Sungchul C. Bai 《Aquaculture Nutrition》2020,26(2):316-327

A 12‐week feeding trial was conducted to investigate the effects of two dietary probiotics; Bacillus subtilis KCTC 2217 or Bacillus licheniformis KCCM 11775 with two prebiotics; mannan oligosaccharide (MOS) or fructooligosaccharide (FOS) in Japanese eel. Fish averaging 12.8 ± 0.47 g (mean ± SD) were randomly distributed into five treatments with triplicate tanks. A basal control diet (CON) and four synbiotic diets supplementing B. subtilis + MOS (BSM), B. subtilis + FOS (BSF), B. licheniformis + MOS (BLM), and B. licheniformis + FOS (BLF). Weight gain and specific growth rate of fish fed all synbiotic diets were higher than those of fish fed CON. Immune‐related gene expression of heat shock protein 70 and immunoglobulin M of fish fed BSF and BLM were significantly higher than those of fish fed CON. Fish fed BSF and BLM had significantly higher intestinal villi length than those of fish fed BLF and CON (p < .05). Disease resistance against Aeromonas hydrophila of fish fed all synbiotic diets were significantly higher than those of fish fed CON (p < .05). Therefore, these results indicated that dietary B. subtilis with FOS (BSF) and B. licheniformis with MOS (BLM) could have beneficial effects on intestinal morphology, and immune‐related gene expression in Japanese eel.  相似文献   

Employment volatility in lagging and advanced regions: The Italian case     

Hasan Engin Duran  Ugo Fratesi 《Growth and change》2020,51(1):207-233

The presence of cycles characterizes all economic systems, but economic cycles have differentiated spatial impacts. Some regions have broader cycles with respect to the country, while others tend to be less responsive to shocks and hence have narrower cycles. Being exposed to broader cycles, that is, greater volatility, may increase the strain on a regional economic system. This paper investigates the different responsiveness to cyclical forces and volatility of regions in the long run. It does so by using quarterly employment data for the Nuts2 Italian regions over almost 40 years before and during the period 1978–2016. Explored in particular are the cross-regional variations in employment volatility and the reasons for the patterns observed, as well as whether they have changed the following different macroeconomic policy regimes. The paper identifies the break dates of different regimes, and these regime changes will be related to policy modifications, such as the implementation of the European Monetary Union. The determinants of this regional volatility appear to be quite stable, so that the changes in volatility are explained by how these determinants have changed overtime and how they are unevenly distributed in space. In particular, the lagging regions of the country suffer, in addition to lower production and income, from higher volatility due to a structure which is weaker and more unstable. Volatility can hence be an additional issue for lagging regions.  相似文献   

Effect of kenaf and EFB fiber hybridization on physical and thermo-mechanical properties of PLA biocomposites     

Md. Saiful Islam  Irmawati Binti Ramli  M. R. Hasan  Md. Moynul Islam  Kh. Nurul Islam  Mahbub Hasan  Ahmad Saffian Harmaen 《Fibers and Polymers》2017,18(1):116-121

Kenaf/empty fruit bunch/polylactic acid (kenaf/EFB/PLA) hybrid biocomposites were prepared using hot press technique. The ratio of fiber to polylactic acid was set at 60:40 with 1:1 ratio between kenaf and empty fruit bunch fibers. Physical, mechanical and thermal properties of hybrid biocomposites were subsequently characterized using Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, tensile and water absorption tests. Test results indicated that mechanically stronger fiber was able to support the weaker fiber. Hybrid fiber biocomposite had higher crystallinity as compared to single fiber biocomposite. Water absorption of hybrid composite was higher as compared to single fiber composite. Thermal result revealed that hybridization of fiber was not significantly influence the thermal properties of composites. However, the presence of two different fibers proposed good wettability properties, which could reduce the formation of voids at the fibers-polymer interface and produce composites with high stiffness and strength.  相似文献   

Economic Analysis of Integrated Pest Management Adoption in Apple Cultivation: a Turkish Case Study     

Mevlüt Gül  Metin Göksel Akpinar  Vecdi Demircan  Hasan Yilmaz  Tufan Bal  Ş. Evrim Arici  Mehmet Polat  Bekir Şan  Figen Eraslan  M. Çağla Örmeci Kart  Damla Gurbuz  Şerife Gülden Yilmaz 《Erwerbs-Obstbau》2017,59(2):147-154

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An Empirical Analysis on the Determinants of Government-subsidised Crop Insurance Purchase in Grape Production in Turkey   总被引：1，自引：0，他引：1  

Hasan Yilmaz  Meltem Merkez  Nukhet Unlu 《Erwerbs-Obstbau》2017,59(1):51-60

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Stock assessment and management implications of anchovy kilka (Clupeonella engrauliformis) in Iranian waters of the Caspian Sea     

Hasan Fazli  Chang Ik Zhang  Douglas Edward Hay  Chun-Woo Lee 《Fisheries Research》2009,100(2):103-108

Recent changes in sea level of the Caspian Sea and ecological impacts caused by the invasive ctenophore (Mnemiopsis leidyi) have altered the ecosystem. A consequence is the changes in the absolute and relative abundance of the commercially important anchovy kilka (Clupeonella engrauliformis) in Iranian waters. To adjust to this change more rigorous management of this fishery is required. This paper examines the maximum sustainable yield (MSY) and fishing intensity at MSY. The paper presents estimates of f_MSY, yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of F_max, F_0.1 and F_40%. We propose a method for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. The MSY and f_MSY were estimated 44,652 mt (metric tons) and 18,609 vessel × nights (a unit of effort). The ABC was estimated at 2190 mt in 2004. In 2005, however, the catch of anchovy kilka was about 4300, over twice the estimated ABC. In 2008 (from January to October) the catch declined to 220 mt. The analyses indicate that overfishing, especially between 2005 and 2008, is the main reason of the collapse of anchovy kilka in the Caspian Sea.  相似文献   

新疆准东矿区土壤与降尘重金属空间分布及关联性分析   总被引：1，自引：3，他引：1  

阿尔祖娜·阿布力米提  王敬哲  王宏卫  茹克亚·萨吾提  阿不都艾尼·阿不里  吾木提·艾山江 《农业工程学报》2017,33(23):259-266

土壤重金属与大气降尘重金属之间的关联性可以反映重金属污染的来源、土壤-大气系统中重金属的传输、迁移和扩散特征。为了研究矿区表层土壤的污染状况及与降尘重金属质量分数间的关联性,该研究以新疆维吾尔自治区准东矿区为研究靶区,利用2014年采集的51个表层土壤和大气降尘样品的室内实测重金属质量分数数据,并基于此分析了样品中6种重金属(As、Cu、Cr、Hg、Pb、Zn)的空间分布特征、地积累指数以及潜在生态风险;利用Pearson相关性分析矩阵和灰色关联法对表层土壤与大气降尘中重金属浓度的相关性和关联度进行探讨。结果表明:1)准东矿区表层土壤重金属的分布状况存在着明显的空间差异,其中Hg的污染程度最严重,处于强-极强度污染,其潜在生态危害指数达到了较高生态风险;Zn和Cu基本处于无污染状态,属于轻微生态风险;2)大气降尘重金属空间分布存在着明显差异,降尘中的Zn处于极强度污染,Hg处于无污染状态;3)Pearson相关分析与灰色关联分析表明,准东地区表层土壤与大气降尘中6种重金属的相关系数大小顺序与关联度排序结果一致,其中Hg和As元素具有较强的一致性,且具有相同的来源,说明大气降尘对表层土壤中重金属的质量分数有一定影响。但因不同重金属元素沉降特性不同,导致各元素之间的关联度有所差异。  相似文献   

Comparison of artificial neural network and regression pedotransfer functions for prediction of soil water retention and saturated hydraulic conductivity   总被引：1，自引：0，他引：1  

Hasan Merdun   zer &#x;nar  Ramazan Meral  Mehmet Apan 《Soil & Tillage Research》2006,90(1-2):108-116

Modeling water flow and solute transport in vadose zone requires knowledge of soil hydraulic properties, which are water retention and hydraulic conductivity curves. As an alternative to direct measurement, indirect determination of these functions from basic soil properties using pedotransfer functions (PTFs) has attracted the attention of researchers in a variety of fields such as soil scientists, hydrologists, and agricultural and environmental engineers. In this study, PTFs for point and parametric (van Genuchten's parameters) estimation of soil hydraulic parameters from basic soil properties such as particle-size distribution, bulk density, and three different pore sizes were developed and validated using artificial neural network (ANN) and multiple-linear regression methods and the predictive capabilities of the two methods was compared using some evaluation criteria. Total of 195 soil samples was divided into two groups as 130 for the development and 65 for the validation of PTFs. Although the differences between the two methods were not statistically significant (p > 0.05), regression predicted point and parametric variables of soil hydraulic parameters better than ANN. Both methods had lower accuracy in parametric predictions than in point predictions. Accuracy of the predictions was evaluated by the coefficient of determination (R²) and the root mean square error (RMSE) between the measured and predicted parameter values. The R² and RMSE varied from 0.637 to 0.979 and from 0.013 to 0.938 for regression, and varied from 0.444 to 0.952 and from 0.020 to 3.511 for ANN, respectively. Even though regression performs insignificantly better than ANN in this case, ANN produces promising results and its advantages can be utilized by developing or using new algorithms in future studies.  相似文献   

Nitrogen fertilization degrades soil aggregation by increasing ammonium ions and decreasing biological binding agents on a Vertisol after 12 years     

Zichun GUO  Wei LI  Mahbub UL ISLAM  Yuekai WANG  Zhongbin ZHANG  Xinhua PENG 《土壤圈》2022,32(4):629-636

Degraded soil aggregation arising from nitrogen(N) fertilization has been reported in many studies; however, the mechanisms have not yet been clarified.Elucidating the impact of N fertilization on soil aggregation would help to improve soil structure and sustain high crop production. The objective of this study was to determine the impact of long-term N fertilization on soil aggregation and its association with binding and dispersing agents. A 12-year(2008–2019) N fertilization field experiment ...  相似文献   

从陈旧血液提取基因组DNA的改进方法     

古丽娜·艾山  木耶赛尔  马合木提·哈力克 《畜禽业》2010,(12)

目的:建立一种快速、有效、陈旧血样基因组DNA的提取方法。方法:采用SDS,EDTA,Tris,蛋白酶K作细胞裂解剂裂解细胞和细胞核,用Tris饱和酚和氯仿:异戊醇(24:1)直接提取基因组DNA。结果该方法提取陈旧血样基因组DNA的纯度高。结论:本法简便、有效,适用于批量陈旧血样的处理。  相似文献