Mathematical modeling of an aqueous film coating process in a Bohle Lab-Coater: Part 2: Application of the model

For the prediction of the air and product temperatures, the product moisture, and the air humidity during a coating process in a Bohle Lab-Coater, a model was developed. The purpose of this work was to determine the limit moisture, the critical moisture, and the constant for the exchange rate between both zones and to use these values for other sets of experiments to test the model. The adaptation of the 3 parameters (limit moisture, critical moisture, and exchange rate constant), was done by calculation of the product temperature in both zones for several sets of parameters in order to minimize the sum of square deviation between the calculated and the measured product temperatures. This set of parameters was used to test the validity of the model. By applying the model, the product temperature could be predicted based on the product, process, and equipment-related parameters. Hence, the model can be used to theoretically investigate the influence of different process paramaters. The mean difference between the predicted, and measured product temperatures in the steady state is ≈2 up to 3 K using the determined parameter set for the limit moisture, the critical moisture, and the exchange rate constant. The model is useful for the prediction of the air and product temperatures, the product moisture, and air humidity during a coating process in the Bohle Lab-Coater using round, biconvex tablets.     

Effects of light on direct and indirect defences against herbivores of young plants of Mallotus japonicus demonstrate a trade-off between two indirect defence traits

Background and Aims

Although most studies on plant defence strategies have focused on a particular defence trait, some plant species develop multiple defence traits. To clarify the effects of light on the development of multiple defence traits, the production of direct and indirect defence traits of young plants of Mallotus japonicus were examined experimentally under different light conditions.

Methods

The young plants were cultivated under three light conditions in the experimental field for 3 months from May to July. Numbers of ants and pearl bodies on leaves in July were examined. After cultivation, the plants were collected and the developments of trichomes and pellucid dots, and extrafloral nectaries (EFNs) on the leaves were examined. On plants without nectar-collecting insects, the size of EFNs and the volume of extrafloral nectar secreted from the EFNs were examined.

Key results

Densities of trichomes and pellucid dots did not differ significantly among the plants under the different light conditions, suggesting that the chemical and physical defences function under both high and low light availability. The number of EFNs on the leaves did not differ significantly among the plants under the different light conditions, but there appeared to be a trade-off between the size of EFNs and the number of pearl bodies; the largest EFNs and the smallest number of pearl bodies were found under high light availability. EFN size was significantly correlated with the volume of extrafloral nectar secreted for 24 h. The number of ants on the plants was smaller under low light availability than under high and moderate light availability.

Conclusions

These results suggest that direct defence traits function regardless of light conditions, but light conditions affected the development of indirect defence traits.     

More insights into the CCN3/Connexin43 interaction complex and its role for signaling

Connexin43 (Cx43) forms gap junction channels but also serves as a signaling center by binding to proteins via its C‐terminus. We have previously demonstrated that transfection of Cx43 leads to significantly reduced proliferation of placental tumor cells through upregulating and binding of the growth regulator CCN3 (NOV) at the C‐terminus of Cx43. Here, we combined fluorescence resonance energy transfer (FRET), co‐immunoprecipitation and proliferation and expression assays to characterize the interaction complex of Cx43 and CCN3. FRET measurements confirmed the interaction of CCN3 with wild‐type Cx43 (amino acids 1‐382) and with mutants of Cx43 truncated at the C‐terminus resulting in Cx43 proteins of amino acids 1‐374, 1‐273, 1‐264, 1‐257 in 293T cells. These results matched the co‐immunoprecipitation data. Interestingly, although FRET revealed distinct efficiencies in interaction of Cx43 with CCN3 for all deletion constructs only wild‐type Cx43 and one deletion construct (1‐374) led to increased CCN3 expression. Only these interactions which were associated with increased CCN3 expression resulted in a reduced cell proliferation. Our study provides evidence that only defined binding properties between Cx43 and CCN3 leading to an upregulation of CCN3 are needed for signaling. Furthermore, the data obtained by FRET analysis allowed us to model the 3D structure of the C‐terminus of Cx43 interacting with CCN3. J. Cell. Biochem. 110: 129–140, 2010. © 2010 Wiley‐Liss, Inc.     

Condition-dependent ejaculate size and composition in a ladybird beetle

Sexually selected male ejaculate traits are expected to depend on the resource state of males. Theory predicts that males in good condition will produce larger ejaculates, but that ejaculate composition will depend on the relative production costs of ejaculate components and the risk of sperm competition experienced by low- and high-condition males. Under some conditions, when low condition leads to poorer performance in sperm competition, males in low condition may produce ejaculates with higher sperm content relative to their total ejaculate and may even transfer more sperm than high-condition males in an absolute sense. Previous studies in insects have shown that males in good condition transfer larger ejaculates or more sperm, but it has not been clear whether increased sperm content represents a shift in allocation or simply a larger ejaculate, and thus the condition dependence of ejaculate composition has been largely untested. We examined condition dependence in ejaculate by manipulating adult male condition in a ladybird beetle (Adalia bipunctata) in which males transfer three distinct ejaculate components during mating: sperm, non-sperm ejaculate retained within the female reproductive tract, and a spermatophore capsule that females eject and ingest following mating. We found that high condition males indeed transferred larger ejaculates, potentially achieved by an increased rate of ejaculate transfer, and allocated less to sperm compared with low-condition males. Low-condition males transferred ejaculates with absolutely and proportionally more sperm. This study provides the first experimental evidence for a condition-dependent shift in ejaculate composition.     

大气热层结条件对林冠显热的影响

应用欧拉二阶闭合模型研究了大气热层结条件下森林冠层显热通量源汇分布和通量特征.结果表明:白天,冠层上的不稳定层结和冠层下的稳定层结是森林冠层大气层结的一种特有现象;温度廓线的变化表明林冠高度2/3处存在较强的热源;冠层内大气处于弱稳定状态时,热量继续向上输送,呈现出热通量的反梯度输送.显热通量日变化的模拟值与实测值吻合,其R2=0.9035(P0.01).在显热收支方程中添加浮力项,可提高反演模型在实际大气中的模拟精度,从而改善模型对热通量收支的模拟能力.     

微细胞介导人14号染色体自A9细胞转移至DT40细胞

为了获得含人14号染色体的DT40细胞,用于人抗体基因的表达研究.本研究利用微细胞介导的染色体转移技术,将A9细胞中的人14号染色体转移至DT40细胞中.首先,摸索秋水仙胺诱导A9细胞微核形成最佳浓度与最佳时间,以终浓度为10 mg/mL的细胞松驰素B破坏细胞骨架,离心分离微细胞,获得的微细胞依次经8μm、5μm、3μm滤膜过滤后与受体细胞DT40融合,细胞铺板后加入G418筛选.然后,对长出的抗性克隆进行基因组DNA检测及FISH杂交,分析人14号染色体在DT40杂合细胞克隆中的存在情况.结果显示,成功获得含人14号染色体的DT40(#14)细胞,三轮试验共获得抗性克隆30个,人14号染色体有效转移率为1×10-6.实验结果表明,人14号染色体完整的自A9细胞转移至DT40细胞,获得的DT40(#14)细胞可用于制备含人抗体基因的人类人工染色体,用于人抗体基因的表达研究.     

小鼠胎脑组织活体转基因技术的建立

目的:建立实用的小鼠活体脑组织基因转染技术。方法:将EGFP质粒(CAGS启动子)注射到胎龄16 d(E16d)的胎鼠侧脑室,用镊形电极隔着子宫壁夹住胎鼠头部,在45 V电压下给予5次电脉冲刺激,每次刺激50ms,间隔1 s;转染后不同天数将胎鼠脑组织完整取出,以4%PFA固定后冰冻切片,进行激光共聚焦照相。结果:EGFP质粒被转入小鼠活体脑组织细胞中并获得表达,动物存活率为90%,GFP阳性率高于80%。结论:通过对麻醉剂、电脉冲刺激、质粒浓度、术中术后处理等多种实验条件的摸索,建立了实用的小鼠胎脑组织活体转基因技术。     

Effects of the sea louse Lepeophtheirus salmonis on temporal changes in cortisol,sex steroids,growth and reproductive investment in Arctic charr Salvelinus alpinus

Groups of mature (5+ year old) Arctic charr Salvelinus alpinus held in sea water were exposed for 34 days to either a high (mean ±s.e . 0·15 ± 0·01 sea lice Lepeophtheirus salmonis g^?1 fish mass) (HI), medium (0·07 ± 0·00 sea lice g^?1 fish mass) (MI) or no [control (C)] sea‐lice infection during early stages of gonad development (June to July). Infection with sea lice resulted in increased plasma cortisol concentrations and this was related to intensity of infection; females tended to have higher cortisol concentrations than males at high infection intensities (HI group: female c. 130 ng ml^?1; male c. 80 ng ml^?1). Plasma osmolality (C c. 330, MI c. 350 and HI c. 415 mOsm) and chloride concentrations (C c. 135, MI c. 155 and HI c. 190 mM) increased significantly with infection intensity, indicating osmoregulatory problems in infected fish. A strong positive relationship between plasma osmolality and cortisol concentration was recorded. Plasma sex‐steroid concentrations were influenced negatively by sea‐lice infection, particularly in the HI group, and were inversely related to plasma cortisol concentrations. The most heavily infected fish postponed the initiation of reproductive development until exposed to fresh water and timing of ovulation tended to be delayed in these fish. Growth rate and condition were negatively influenced by sea‐lice infection and growth rate was inversely related to plasma cortisol concentrations. Sea‐lice infection resulted in mortality among females in the HI group, and the proportion of maturing females was lower in the MI group (46%) than in the controls (85%). Egg production in the MI and HI groups was c. 50 and 30% of the C group. Egg size, embryonic survival and fry mass did not differ across groups. Sea lice influence reproductive development and egg production in S. alpinus, and consequently these parasites may influence populations via sublethal effects on broodfish, affecting growth and condition, and their reproductive output.     

H-Bonding and Positive Charge at the N(5)/O(4) Locus Are Critical for Covalent Flavin Attachment in Trametes Pyranose 2-Oxidase

Flavoenzymes perform a wide range of redox reactions in nature, and a subclass of flavoenzymes carry covalently bound cofactor. The enzyme-flavin bond helps to increase the flavin's redox potential to facilitate substrate oxidation in several oxidases. The formation of the enzyme-flavin covalent bond—the flavinylation reaction—has been studied for the past 40 years. For the most advocated mechanism of autocatalytic flavinylation, the quinone methide mechanism, appropriate stabilization of developing negative charges at the flavin N(1) and N(5) loci is crucial. Whereas the structural basis for stabilization at N(1) is relatively well studied, the structural requisites for charge stabilization at N(5) remain less clear. Here, we show that flavinylation of histidine 167 of pyranose 2-oxidase from Trametes multicolor requires hydrogen bonding at the flavin N(5)/O(4) locus, which is offered by the side chain of Thr169 when the enzyme is in its closed, but not open, state. Moreover, our data show that additional stabilization at N(5) by histidine 548 is required to ensure high occupancy of the histidyl-flavin bond. The combination of structural and spectral data on pyranose 2-oxidase mutants supports the quinone methide mechanism. Our results demonstrate an elaborate structural fine-tuning of the active site to complete its own formation that couples efficient holoenzyme synthesis to conformational substates of the substrate-recognition loop and concerted movements of side chains near the flavinylation ligand.