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21.
Using a simultaneous equation econometric model based on yearly data between 1997 and 2006 for the Aegean Lignite Enterprise this study examines factors that affect the lignite price in Turkey. The Aegean Lignite Enterprise produces and sells the lignite of Soma and Can and their data reflect the general Turkish situation. The results suggest that (1) lignite prices sold to the industry increase (decrease) depending on the decrease (increase) in the industrial production and (2) total electricity production and electricity price are the most important factors that potential investors and related persons have to take into consideration for the pricing of lignite in the thermal power plant market.  相似文献   
22.
Abstract: Remediation of waters impaired by bacterial indicators is usually dictated by total maximum daily load plans, which are heavily dependent on fate and transport modeling of bacterial indicators. Nonpoint source pollution models are most frequently used to assess bacterial transport to surface waters and most models typically simulate bacterial transport as a dissolved pollutant. Previous studies have found that cells preferentially attach to sediments; however, a variety of techniques have been used to assess attachment including filtration, fractional filtration, and centrifugation. In addition, a variety of chemical and physical dispersion techniques are used to release attached and bioflocculated cells from particulates. Here we developed and validated an easy‐to‐replicate laboratory procedure for separation of unattached from attached E. coli which will also identify particle sizes to which E. coli preferentially attach. Physical and chemical dispersion techniques were evaluated and a combined hand shaker treatment for 10 min followed by dilutions in 1,000 mg/l of Tween 85 significantly increased total E. coli concentrations by 31% when compared with a control. In order to separate unattached from attached fractions, two commonly used techniques, fractional filtration, and centrifugation were combined. The filtration and centrifugation treatments did not reduce E. coli concentrations when compared with a control (p > 0.05), indicating that damage was not inflicted upon the E. coli cells during the separation procedure.  相似文献   
23.
The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was to test the efficiency of the antibiotic resistance analysis (ARA) method under low resistance by tracking the fecal sources at Turkey Creek, Oklahoma exhibiting this condition. The resistance patterns of 772 water-isolates, tested with nine antibiotics, were analyzed by discriminant analysis (DA) utilizing a five-source library containing 2250 isolates. The library passed various representativeness tests; however, two of the pulled-sample tests suggested insufficient sampling. The resubstitution test of the library individual sources showed significant isolate misclassification with an average rate of correct classification (ARCC) of 58%. These misclassifications were explained by low antibiotic resistance (Wilcoxon test P < 0.0001). Seasonal DA of stream E. coli isolates for the pooled sources human/livestock/deer indicated that in fall, the human source dominated (P < 0.0001) at a rate of 56%, and that human and livestock respective contributions in winter (35 and 39%), spring (43 and 40%), and summer (37 and 35%) were similar. Deer scored lower (17–28%) than human and livestock at every season. The DA was revised using results from a misclassification analysis to provide a perspective of the effect caused by low antibiotic resistance and a more realistic determination of the fecal source rates at Turkey Creek. The revision increased livestock rates by 13–14% (0.04 ≤ P ≤ 0.06), and decreased human and deer by 6–7%. Negative misclassification into livestock was significant (0.04 ≤ P ≤ 0.06). Low antibiotic resistance showed the greatest effect in this category.  相似文献   
24.
报道了锦蛇属团花锦蛇(E.davidi)、绿锦蛇(E.prvsina)和三索锦蛇(E.radiata)3个种的核型和Ag-NORs,团花锦蛇的型2n=36(8V+6sV+2I+20M),绿锦蛇的核型2n=36(7V+7sV+2I+20m),三索锦蛇的核型2n=40(6V+3sV+2sI+5I+24m);①团花锦蛇和绿锦蛇的染色体数目和结构与此属大多数咱的相似,;②此种为雄性,未见染色体异型。③Ag  相似文献   
25.
Summary. We investigated the hypothesis that aggregation signals produced by male webbing clothes moths (WCM), Tineola bisselliella (Hum.) (Lepidoptera: Tineidae), and close-range male attractant signals produced by females have a pheromonal basis, at least in part. Gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric analyses of bioactive methanolic extracts of male WCM disclosed three candidate pheromone components: hexadecanoic acid methyl ester (16:Ester), (Z)-9-hexadecenoic acid methyl ester (Z9—16:Ester), and octadecanoic acid methyl ester (18:Ester). In bioassay experiments in a large Plexiglas™ arena, a blend of synthetic 16:Ester plus Z9—16:Ester was attractive to male and virgin (but not mated) female WCM; the 18:Ester was inactive. GC-EAD analyses of pheromone gland extracts from female WCM revealed (E,Z)-2,13-octadecadienal (E2Z13—18:Ald) and (E,Z)-2,13-octadecadienol (E2Z13—18:OH) as candidate sex pheromone components. In arena bioassay experiments, 1—5 female equivalents of synthetic E2Z13—18:Ald (0.2 ng) and E2Z13—18:OH (0.1 ng) were more attractive to male WCM than were two virgin female WCM. We anticipate that the combination of aggregation and sex pheromones, male-produced sonic aggregation signals, and habitat-derived semiochemicals will be highly effective in attracting male and female WCM to commercial traps. Received 12 January 2001; accepted 8 June 2001.  相似文献   
26.
A mercury biosensor was constructed by integrating biosensor genetic elements into E. coli JM109 chromosome in a single copy number, using the attP/attB recombination mechanism of λphage. The genetic elements used include a regulatory protein gene (merR) along with operator/promoter (O/P) derived from the mercury resistance operon from pDU1358 plasmid of Serratia marcescens. The expression of reporter gene gfp is also controlled by merR/O/P. Integration of the construct into the chromosome was done to increase the stability and precision of the biosensor. This biosensor could detect Hg(II) ions in the concentration range of 100-1700 nmol/L, and manifest the result as the expression of GFP. The GFP expression was significantly different (P ≤ 0.05) for each concentration of inducing Hg(II) ions in the detection range, which reduces the chances of misinterpretation of results. A model using regression method was also derived for the quantification of the concentration of Hg(II) in water samples.  相似文献   
27.
探究邻苯二甲酸二丁酯诱导小鼠神经行为学改变及与细胞外调节蛋白激酶(ERK1/2)通路相关蛋白的关联.雄性KM小鼠36只,随机分成4组:生理盐水组、50 mg·kg~(-1)·d~(-1) DBP组、50 mg·kg~(-1)·d~(-1)维生素E(VE)组、DBP+VE组,连续灌胃处理28 d,观察Morris水迷宫结果,检测小鼠脑海马组织的氧化应激(活性氧(ROS)荧光强度、还原型谷胱甘肽(GSH)与丙二醛(MDA)含量)、脑源性神经营养因子(BDNF)、磷酸化cAMP反应元件结合蛋白(p-CREB)、caspase-3水平,Western blot分析ERK1/2及其磷酸化(p-ERK1/2)水平;HE、Nissl染色及Hoechst 33258荧光染色分析脑组织CA1区病理学变化.结果表明,与对照组比较,50 mg·kg~(-1)·d~(-1) DBP组小鼠的学习记忆下降,氧化应激、p-ERK1/2、caspase-3水平上升,BDNF、p-CREB表达下降,差异均有统计学意义(p0.05,p0.01);海马组织CA1病理学损伤及凋亡程度增加.给予抗氧化剂VE处理后,DBP+VE组小鼠的学习记忆上升,氧化应激、p-ERK1/2、caspase-3水平降低,BDNF、p-CREB表达上升,差异均有统计学意义(p0.05);海马组织CA1病理学损伤及凋亡程度降低.由此推测,DBP暴露导致小鼠海马组织CA1病理学损伤、神经元凋亡程度增加、学习记忆下降、其神经行为学改变可以通过添加VE得到缓解,相关生理生化指标测试表明ERK系统应激氧化性损伤机制参与介导了毒理学过程.  相似文献   
28.
In order to provide a noninvasive prenatal diagnosis of the hemoglobin E (Hb E) related disorder, we have evaluated the possibility of identifying the fetal βE-globin gene in maternal plasma. The analysis was performed during 8 to 18 weeks of gestation using DNA extracted from 200 µL of plasma from pregnant women whose husbands carried Hb E. The βE-globin mutation in maternal plasma was detected by a nested PCR amplification followed by the Mnl I restriction analysis. The result was compared with that of routine analysis of the CVS specimens. Among the five pregnant women examined, the fetal βE-globin gene was identified in maternal plasma in three of them and the result was completely concordant with the conventional CVS analysis. This simple noninvasive prenatal detection of the fetal βE-globin gene should prove useful in a prevention and control program of Hb E/β-thalassemia in countries where the βE-globin gene is prevalent. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
29.
Summary. The sex pheromone of Ostrinia orientalis (Lepidoptera: Crambidae) was analyzed by gas chromatography–electroantennographic detection (GC–EAD), GC–mass spectrometry and a series of bioassays. Three EAD-active compounds were detected in the female sex pheromone gland extract, and identified as tetradecyl acetate (14:OAc), (Z)-11-tetradecenyl acetate (Z11-14:OAc) and (E)-11-tetradecenyl acetate (E11-14:OAc). The titers (ratio) of 14:OAc, Z11-14:OAc and E11-14:OAc in 3-day-old virgin females were 0.49 ng (10), 4.86 ng (98) and 0.10 ng (2), respectively. In a wind-tunnel bioassay, the 98:2 blend of Z11- and E11-14:OAc, but not Z11-14:OAc alone, elicited the same male behavioral responses as virgin females and crude gland extracts. 14:OAc was inactive by itself, and did not show any synergistic effect on the binary blend. Field trapping experiments also confirmed the attractiveness of the binary blend to O. orientalis males. Based on these results, we concluded that the sex pheromone of O. orientalis is a 98:2 mixture of Z11-14:OAc and E11-14:OAc. This sex pheromone is very similar to that of the Z-type European corn borer, O. nubilalis. The present finding raises the question of whether O. orientalis , which is indistinguishable from O. nubilalis based on external morphology, is a biologically distinct species independent from O. nubilalis.  相似文献   
30.
On the basis of physical features and autopsy findings, a child with congenital hydrocephalus, bilateral microphthalmia, myopathy, severe developmental retardation and multiple brain malformations was diagnosed to have the Walker-Warburg Syndrome (WWS). During a subsequent pregnancy in this family, a fetus at risk for this autosomal recessive condition was evaluated with serial ultrasound examinations. At 15 weeks of gestation an encephalo-cele was noted. Disproportionately slow growth of the head compared to the body was noted at 36 weeks. At birth, the diagnosis of WWS was confirmed in the child due to the presence of microcephaly, an encephalocele, a meningocele and bilateral microphthalmia. This is the first reported case of the early prenatal diagnosis of this recently categorized genetic condition, in which the major features are hydrocephalus, multiple central nervous system malformations, microphthalmia with ocular malformations, severe psychomotor retardation, congenital myopathy and a very limited life expectancy.  相似文献   
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