Abamectin, soil-born bacterial acaricides, has been intensively used to control Tetranychus urticae. Target site insensitivity and enhanced activity of detoxification enzymes have been considered as major resistance mechanisms. Here, we identified the differentially expressed genes after feeding sublethal dose of abamectin for 36 h by RNA-seq analysis. About 4.9 million reads (± 2,630,543 reads) were assembled into T. urticae. Among a total of 75 genes showing differential transcription, 18 and 14 genes were up- and down-regulated over two fold ratio, respectively. In the validation analysis, the calculated fold change of each genes between RNA-seq and qPCR were moderately correlated (r 2 = 0.661). A cuticular protein was shown as the highest up-regulated gene (192.3-fold) and a chitinase was revealed to be the highest down-regulated (-16.4-fold). Further study would be necessary to validate their roles in T. urticae adaptation to acaricides.

Most insects possess two different acetylcholinesterases (AChEs) (i.e., AChE1 and AChE2). It has been recently reported that both AChEs are equally active in a damselfly species, providing a unique example of the incomplete specialization of one AChE function after duplication (Kim and Lee, 2013). In this study, we investigated the tissue distribution patterns and the molecular and inhibitory properties of two AChEs (i.e., VgAChE1 and VgAChE2) from the Vestalis gracilis damselfly. VgAChEs exhibited almost identical catalytic activity and were expressed in the central nervous system (CNS). The most predominant molecular form of both VgAChEs was a disulfide-bridged dimer, which is associated with the cell membrane via a glycosylphosphatidylinositol anchor. In an inhibition assay, however, VgAChE1 and VgAChE2 exhibited different sensitivities to organophosphate and carbamate insecticides depending on the structure of the inhibitors. These findings suggest that both VgAChEs have neuronal functions. In addition, soluble monomeric and cleaved molecular forms were detected in both the CNS and peripheral nervous system tissues by an AChE2-specific antibody, implying that VgAChE2 probably shares both neuronal and non-neuronal physiological functions in V. gracilis. Our results support the notion that both VgAChEs, paralogous of each other, are involved in synaptic transmission, with VgAChE2 being in the early stage of acquiring non-neuronal functions.

The oil sands are loose sand or partially consolidated sandstone containing naturally occurring mixtures of sand, clay, and water, saturated with a dense and viscous from of bitumen. Natural bitumen deposits are found in large quantities in Alberta and Utah area. Nevertheless of its environmental issues, a large-scale commercial oil sands industry is expected to increase in coming decades.(1) The present paper focuses on physico-chemical analysis of two different types of bitumens. These bitumen samples were chosen based on: the original source (oil sand and crude petroleum), and mode of process. The aim of this study is to determine both the manufacturing effect on chemical species and the chemical organization as a function of the type of bitumen sample. In order to obtain information on bitumen chemistry, elemental analysis (C, H, N, S, and O), heavy metal (Ni, V) concentrations, IATROSCAN chromatography (thin layer chromatography-flame ionization detection), FTIR spectroscopy, and NMR spectroscopy (1H NMR,13C NMR)haveallbeenused.The characterization includes information about the major compound types (saturates, aromatics, resins and asphaltenes) which can be compared with similar data for other bitumens, more importantly, can be correlated with data from petroleum samples for which refining characteristics are known. Examination of oil sand asphalt showed that it differed significantly from representative petroleum residues, principally in their nonhydrocarbon content and aromatic compounds. When possible, properties and composition were related to recovery and refining processes. This information is important because of the effects that composition has on recovery and processing reactions.

본 연구는 국내에서 생산된 주요 동계 사료작물인 청보리 및 청호밀 사일리지를 이용하여 거세 한우의 비육후기(25~30개월 령) 용으로 조제된 TMR의 소 체내 이용성을배합사료 및 볏짚으로 구성된 관행 사료와 비교하고자 반추위 누관이 장착된 소 3두를 이용하여 3 × 3 Latin squaredesign 방법으로 실시되었다. 시험동물에는 비육 후기용 배합사료 및 볏짚을 분리 급여하였거나 (대조구) 청보리 사일리지 TMR (BS-TMR) 또는 청호밀 사일리지 TMR (RSTMR)을 급여하였다. 전체 채취시간에 걸쳐 반추위액의pH, 암모니아 농도 및 총 휘발성지방산 농도는 시험사료간 차이가 없었다. Acetate (C2)의 조성 비율은 사료 급여후 1시간에서 청보리 사일리지를 섭취한 처리구 (BS-TMR)에서 낮은 (p<0.033) 값을 제외하고는 대부분의 채취시간에서 시험사료 간 차이가 없었다. Propionate (C3) 및 butyrate조성비율과 C2/C3 비율 역시 모든 채취시간에서 시험사료간 차이가 없었다. 사료 내 주요 성분의 반추위 유효분해율과 전장소화율은 전체 시험사료 간은 물론 BS-TMR과RS-TMR 간에도 차이가 없는 것으로 나타났다. 본 대사시험 결과로 미루어보아 청보리 및 청호밀로 제조된 TMR의급여 가치가 배합사료 및 볏짚의 분리급여와 차이가 없는것으로 여겨진다.

We present the relation between the genus in cosmology and the Betti numbers for excursion sets of three- and two-dimensional smooth Gaussian random fields, and numerically investigate the Betti numbers as a function of threshold level. Betti numbers are topological invariants of figures that can be used to distinguish topological spaces. In the case of the excursion sets of a three-dimensional field there are three possibly non-zero Betti numbers; β0 is the number of connected regions, β1 is the number of circular holes (i.e., complement of solid tori), and β2 is the number of three-dimensional voids (i.e., complement of three-dimensional excursion regions). Their sum with alternating signs is the genus of the surface of excursion regions. It is found that each Betti number has a dominant contribution to the genus in a specific threshold range. β0 dominates the high-threshold part of the genus curve measuring the abundance of high density regions (clusters). β1 dominates the genus near the median thresholds which measures the topology of negatively curved iso-density surfaces, and β2 corresponds to the low-threshold part measuring the void abundance. We average the Betti number curves (the Betti numbers as a function of the threshold level) over many realizations of Gaussian fields and find that both the amplitude and shape of the Betti number curves depend on the slope of the power spectrum n in such a way that their shape becomes broader and their amplitude drops less steeply than the genus as n decreases. This behaviour contrasts with the fact that the shape of the genus curve is fixed for all Gaussian fields regardless of the power spectrum. Even though the Gaussian Betti number curves should be calculated for each given power spectrum, we propose to use the Betti numbers for better specification of the topology of large scale structures in the universe.

Isotropic pitch fibers were stabilized and carbonized for preparing carbon fibers. To optimize the duration and temperature during the stabilization process, a thermogravimetric analysis was conducted. Stabilized fibers were carbonized at 1000, 1500, and 2000℃ in a furnace under a nitrogen atmosphere. An elemental analysis confirmed that the carbon content increased with an increase in the carbonization temperature. Although short graphitic-like layers were observed with carbon fibers heat-treated at 1500 and 2000℃, Raman spectroscopy and X-ray diffraction revealed no significant effect of the carbonization temperature on the crystalline structure of the carbon fibers, indicating the limit of developing an ordered structure of isotropic pitch-based carbon fibers. The electrical conductivity of the carbonized fiber reached 3.9×10⁴S/m with the carbonization temperature increasing to 2000℃ using a four-point method.

Food contact packaging material should be stable and non-reactive with the food that it is in contact with, and must promote the safety of food. However, for a number of years, there has been evidence that indefinitely small amounts of chemicals could migrate or leach from food packaging materials into the foods they hold. The chemistry and toxicity of such leachates are well-known and documented; and there is a growing concern over the matter among the general public. In addition, food regulatory agencies are imposing more stringent regulations on the maximum allowable amounts of known leachates into foods in recent years. The majority of toxicity studies have revealed that trace amounts of leachates pose no immediate health problems in humans. However, studies on the effects of long-term exposure or synergistic/cumulative toxicity are still lacking. The present review provides an overview of the chemical nature and toxicity of certain leachates from various types of food contact packaging materials that are in wide use.