Biodegradation Kinetics and Effects of Operating Parameters on the Performance of a Methyl Tert-Butyl Ether Degrading Biofilter

The goals of the study were to determine the effectiveness of a laboratory-scale biofilter on the removal of methyl tert-butyl ether (MTBE) and investigate the operating parameter effects on biofilter performance. The experimental results show that average MTBE removals of 53.6–93.2% were observed at loads of 2.5–20.1 gm^?3 h^?1 and an empty-bed residence time of three minutes, after continuous operation for four months throughout the biofilter acclimation period. After a one-day recovery period operation, the biofilter system recovered from the introduction of a shock load. More than 99% removal efficiencies were achieved for the inlet MTBE concentration at 50 ppmv and with the highest residence time. MTBE removals at the bottom section of the biofilter were consistently lower than for the top section, which was attributed to insufficient microorganism growth in the bottom section. The parameters estimated by using the Michaelis-Menten equation were 1.116 ± 0.51 ppmv s^?1 for the maximum removal rate (V _m ), and 26.38 ± 17.21 ppmv for the half-saturation constant (Ks), evaluated at the biofilter exit.     

Export of Dissolved Inorganic Nitrogen in a Partially Cultivated Subtropical Mountainous Watershed in Taiwan

A spatial and temporal investigation of dissolved inorganic nitrogen (DIN; NO₃, NO₂ and NH₄) was conducted under various water discharge conditions in Lanyang-Hsi, a subtropical mountainous stream, which drains through distinct degrees of agriculture-influenced sub-watersheds. In both the cultivated and non-cultivated sub-watersheds, NO₃ was the most abundant species accounting for >80% of total DIN, while NH₄ and NO₂ accounted for <15% and=" 5%=" of=" din,=" respectively.=" agricultural=" activities=" along=" the=" riverbank=" led=" to=" significantly=" higher=">₃ concentrations (13–246 M) and DIN yields (1300–3800 kg N km^–2 yr^–1) in main channel when compared to those of non-cultivated tributaries (9–38 M for NO₃ and 550–740 kg N km^–2 yr^–1 for yield). The much lower and less variable DIN yields observed in tributary stations (mean = 660 ± 120 kg N km^–2 yr^–1) are considered as the present day background of DIN yield, which is significantly higher than those of most natural watersheds in other regions. Elevated atmospheric DIN deposition is likely the cause for the high background DIN yield. Human activity within the watershed results in additional DIN yield, which accounted for 49% of total N export. However, the reported atmospheric DIN input in northern Taiwan (1800 kg N km^–2 yr^–1) is much higher than the background DIN yield implying that a major fraction (70%) of atmospheric inputs are retained or processed within the watershed. A dilution pattern occurred in the main channel where high NO₃ concentrations from the upstream sources decreased significantly in downstream direction due to inputs of NO₃-diluted water from non-cultivated areas. We adopted a two-source mixing model to predict the NO₃ dilution pattern. This model revealed a third yet not recognized N source in the lower part of watershed. Model results also indicated the importance of water discharge rate in regulating the relative contribution to total DIN export among these sources.     

Evaluation of extraction methodologies for corn kernel (Zea mays) DNA for detection of trace amounts of biotechnology-derived DNA

Sensitive and accurate testing for trace amounts of biotechnology-derived DNA from plant material requires pure, high-quality genomic DNA as template for subsequent amplification using the polymerase chain reaction (PCR). Six methodologies were evaluated for extracting DNA from ground corn kernels spiked with 0.1% (m/m) CBH351 (StarLink) corn. DNA preparations were evaluated for purity and fragment size. Extraction efficiency was determined. The alcohol dehydrogenase gene (adh1) and the CBH351 (cry9C, 35S promoter) genes in the genomic DNA were detected using PCR. DNA isolated by two of the methods proved unsuitable for performing PCR amplification. All other methods produced some DNA preparations that gave false negative PCR results. We observed that cornstarch, a primary component of corn kernels, was not an inhibitor of PCR, while acidic polysaccharides were. Our data suggest that amplification of an endogenous positive control gene, as an indicator for the absence of PCR inhibitors, is not always valid. This study points out aspects of DNA isolation that need to be considered when choosing a method for a particular plant/tissue type.     

DIE AUFNAHME VON ADSORBIERTEM MONOLINURON IM BODEN DURCH SENFPFLANZEN

Zusammenfassung. Um den Einfluß verschiedener Bodenmischungen auf die Aufnahme von adsorbiertem [¹⁴C]-markíertem Monolinuron zu verfolgen, wurden jeweils 30, 45, 60, 73 und 90 g Monolinuron-behandelter Boden (0,42-0,53 μg Monolinuron/g Boden) mit unbehandeltem auf 100 g aufgefüllt und damit 15.4–67.1 μg adsorbiertes Monolinuron eingesetzt. Die Aufnahme durch Senipflanzen wurde in Neubauerversuchen während 24 Tagen verfolgt. In 3 Anbauperioden wurden 1.17–9.74 μg aufgenommen. Der überwiegende Teil blieb jedoch an den Boden adsorbiert. Bei einer Bilanzerstellung konnten 99% der zu Versuchsbeginn eingesetzten Monolinuronmenge wieder gefunden werden, Durch den Sorptionsprozeß wurde Monolinuron chemisch nicht vcerändert. Ebenso kann das Ausgangsmolekül in der Pflanze nachgewiesen werden. Die nachweisbare Monolinuronmenge in der Pflanzensubstariz wird umso geringer, je weiter die Aufnahmeintensität zurürkgeht. Über eine Isotopen-Austauschreaktion wurde versucht, das pflanzenverfügbare Monolinuron zu messen.
The uptake of adsorbed monolinuron in the soil by mustard plants     

Oxygen reservoirs in the early solar nebula inferred from an allende CAI

Ultraviolet laser microprobe analyses of a calcium-aluminum-rich inclusion (CAI) from the Allende meteorite suggest that a line with a slope of exactly 1.00 on a plot of delta17O against delta18O represents the primitive oxygen isotope reservoir of the early solar nebula. Most meteorites are enriched in 17O and 18O relative to this line, and their oxygen isotope ratios can be explained by mass fractionation or isotope exchange initiating from the primitive reservoir. These data establish a link between the oxygen isotopic composition of the abundant ordinary chondrites and the primitive 16O-rich component of CAIs.     

A simplified modelling approach for pesticide transport in a tile-drained field: The PESTDRAIN model

The paper presents a simplified model called PESTDRAIN. It simulates pesticide transport in a subsurface tile-drained field. It computes surface runoff and tile-drainage flow rates, along with the associated pesticide concentrations, with a variable event-driven time step. PESTDRAIN consists of three coupled modules: SIDRA, SIRUP and SILASOL. SIDRA and SIRUP are the water flow simulation modules in the saturated and unsaturated zones, respectively. SIDRA follows a simplified physically based approach while SIRUP follows a conceptual capacitive approach. SILASOL is the solute transport module for both the saturated and unsaturated zones and is based on transfer functions. It includes simple representations of adsorption and degradation of pesticides.PESTDRAIN was tested on field data sets collected for three drainage seasons at the La Jaillière experimental site in north-western France, for the wheat herbicides isoproturon (IPU) and diflufenican (DFF). After model calibration, relative errors for drainage and surface runoff flows over the season were 14% and 4%, respectively, and the Nash-Sutcliffe efficiency coefficient (N_eff) value for drainage discharge was 0.58. A fair reproduction of a high temporal resolution IPU concentration data set in drainage discharge was also obtained (N_eff=0.28). For the validation data sets, PESTDRAIN was able to simulate accurately drainage discharge with Nash-Sutcliffe efficiency coefficients of 0.57 and 0.69. The global N_eff was 0.44 for all flow-weighted average weekly concentrations in drainage. Relative errors for the pesticide losses were 2.5% and 35% (IPU), and 60% (DFF). For surface runoff the results were not as accurate, but they remained correct in terms of time location and order of magnitude. Although further validation is necessary with more field data, PESTDRAIN appears as a promising tool for agricultural water management.     

Osseous lesions resembling vaccine-site sar comas in two cats

Extract

Lytic lesions with microscopic features similar to those of vaccine-site sarcomas were diagnosed in the distal femur of two young neutered male cats, one a 20-month-old Birman and the other an 18-month-old domestic short-hair (DSH). Radiographically, there was extensive destruction of trabecular and cortical bone in the metaphysis and/or epiphysis of the distal femur. The DSH cat also had angular deformity of the distal femur due to asymmetrical involvement of the physis. Histologically, the lesions in both cats consisted of dense, interwoven bundles of fibrous connective tissue, amongst which there were variable numbers of plump malignant mesenchymal cells, often with very large, hyperchromatic nuclei and irregularly shaped nucleoli. Several focal aggregates of small lymphocytes were present in both tumours. Although neither cat had apparently been vaccinated in the hindlimb it is possible that the tumours had been triggered by injection of some other irritant material.     

呼和浩特市国土空间功能评价及优化分区研究

市域国土空间功能评价研究是市级国土空间规划编制的基础,准确评价国土空间功能及分区可为规划实施和用途管制提供科学依据.以乡级行政单位为评价单元,通过归并分类、全局与局部空间自相关等方法分析国土空间功能及其空间分布特征;采用两维图论聚类算法,在空间邻接性和区域完整性前提下对国土空间功能进行分区,并根据分区结果提出发展建议....     

Cytokines, Growth Factors and Prostaglandin Synthesis in the Uterus of Pregnant and Non-pregnant Bitches: The Features of Placental Sites

Uterine tissue from pregnant bitches was investigated by qualitative RT-PCR for the gene expression of local factors potentially important for the implantation of canine embryos. For this purpose, 10 bitches identified as being at the time of implantation or early placentation by means of ultrasonography before ovariohysterectomy (days 20–35, n = 10) provided tissues for comparison to tissue collected in a previous study and identified as early pregnant (n = 10) or non-pregnant (n = 4) by embryo flushing after ovariohysterectomy (days 10–12 after mating; Schäfer-Somi et al. 2008 ). Uterine tissue was excised from the middle of the left horn from early pregnant and non-pregnant animals, including from interplacental and placentation sites. The following genes were investigated: CD-4, -8; cyclooxygenase (COX)-1, -2; granulocyte macrophage-colony stimulating factor (GM-CSF); hepatocyte growth factor (HGF); insulin-like growth factor (IGF)-1, -2; transforming growth factor (TGF) and tumour necrosis factor (TNF)-α; interferon (IFN)-γ; interleukin (IL)-1β, -2, -4, -6, -8, -10, -12; leukaemia inhibitory factor (LIF) and leptin. Gene expression for CD-8, COX-1, TGF-β, HGF, IGF-1, IL-2, -4,-10, IFN-γ and LIF were detected in the pre-implantation uterus, and all except IL-2 and -10 were still detectable during the implantation and placentation stage. During implantation, mRNA for IGF-2 and GM-CSF were additionally detected. The dioestrous uterus differed from the pregnant uterus because of the absence of CD-8, IL-4 and IFN-γ and the expression of CD-4, TNF-α and IL-6. The results suggest that IL-4, IFN-γ, CD-8, GM-CSF and IGF-2 are regulated in a pregnancy-specific manner and that GM-CSF and IGF-2 probably have growth supporting and immune modulating functions during implantation of the canine embryo.     

天然保鲜剂对冷却牦牛肉的保鲜效果研究

[目的]为了解决牦牛肉的保鲜问题.[方法]本研究采用天然保鲜材料魔芋、生姜、洋葱、月桂叶,经榨汁、浸提、分离等处理,配成一定比例的天然保鲜剂,对冷却牦牛肉进行涂膜处理,采用L9(34)正交试验,选出最优保鲜剂组合,即生姜15%、魔芋0.7%、月桂叶0.5%、洋葱15%.冷却牦牛肉经涂膜保鲜后,在0～3℃条件下贮藏、保鲜期可达17 d,贮藏期间,冷却牛肉经TVBN(挥发性盐基总氮)测定,pH值、感观表现均符合国标标准.[结果]表明,四种保鲜材料均有一定的保鲜效果,[结论]说明天然保鲜剂保鲜方法具有安全、经济、方便等特点.