The global distribution of wind-induced upwelling

The global distribution of wind-induced upwelling at the base of the surface Ekman layer has been computed from the COADS monthly wind stress from 1950 to 1988. In contrast to previous studies where the Ekman transport equations became invalid near the Equator, this paper computed upwelling right to the equator by incorporating friction in the surface transport equations. Comparing the seasonal changes in the equatorial upwelling between the Atlantic and the Pacific, we found that the Atlantic had the larger magnitude change while the Pacific had the larger latitudinal shift. The anomalous wind-induced upwelling/downwelling associated with El Niño were computed over several latitudinal bands in the Pacific by compositing the data from six El Nino events. By plotting the July zonally averaged upwelling anomalies in the Pacific in a latitude-time contour plot, we found northward phase propagation at about 3.5° latitude per decade in the low latitudes, a feature not found in the January upwelling. Long-term upwelling trends were computed and their potential influence on fisheries are discussed.     

粘土作为乳化剂的研究Ⅰ.粘土悬液的pH值与乳浊液稳定性的关系

固体粉末可以作为乳化剂早在本世紀初就已发现^[1]。由于所得的乳浊液一般地讲液滴较粗,稳定性也差,因而长期以来很少被注意。最近L.N.Mukerjee和S.N.Srivastava等人系統地检查了多种难溶无机化合物和粘土作为工业用和农业喷洒用乳化剂的可能性^[2,3]。但对于粘土粉末作为乳化剂的条件没有深入研究。本文是研究一定pH范围内几种本国粘土的乳化效能。     

Antcin B and its ester derivative from Antrodia camphorata induce apoptosis in hepatocellular carcinoma cells involves enhancing oxidative stress coincident with activation of intrinsic and extrinsic apoptotic pathway

The triterpenoids methylantcinate B (MAB) and antcin B (AB), isolated from the medicinal mushroom Antrodia camphorata , have been identified as strong cytotoxic agents against various type of cancer cells; however, the mechanisms of MAB- and AB-induced cytotoxicity have not been adequately explored. This study investigated the roles of caspase cascades, reactive oxygen species (ROS), DNA damage, mitochondrial disruption, and Bax and Bcl-2 proteins in MAB- and AB-induced apoptosis of hepatocellular carcinoma (HCC) HepG2 cells. Here, we showed that MAB and AB induced apoptosis in HepG2 cells, as characterized by increased DNA fragmentation, cleavage of PARP, sub-G1 population, chromatin condensation, loss of mitochondrial membrane potential, and release of cytochrome c. Increasing the levels of caspase-2, -3, -8, and -9 activities was involved in MAB- and AB-induced apoptosis, and they could be attenuated by inhibitors of specific caspases, indicating that MAB and AB triggered the caspase-dependent apoptotic pathway. Additionally, the enhanced apoptotic effect correlates with high expression of Fas, Fas ligand, as well as Bax and decreased protein levels of Bcl-(XL) and Bcl-2, suggesting that both the extrinsic and intrinsic apoptosis pathways were involved in the apoptotic processes. Incubation of HepG2 cells with antioxidant enzymes superoxide dismutase and catalase and antioxidants N-acetylcysteine and ascorbic acid attenuated the ROS generation and apoptosis induced by MAB and AB, which indicate that ROS plays a pivotal role in cell death. NADPH oxidase activation was observed in MAB- and AB-stimulated HepG2 cells; however, inhibition of such activation by diphenylamine significantly blocked MAB- and AB-induced ROS production and increased cell viability. Taken together, our results provide the first evidence that triterpenoids MAB and AB induced a NADPH oxidase-provoked oxidative stress and extrinsic and intrinsic apoptosis as a critical mechanism of cause cell death in HCC cells.     

Time series analyses reveal transient relationships between abundance of larval anchovy and environmental variables in the coastal waters southwest of Taiwan

We investigated environmental effects on larval anchovy fluctuations (based on CPUE from 1980 to 2000) in the waters off southwestern Taiwan using advanced time series analyses, including the state-space approach to remove seasonality, wavelet analysis to investigate transient relationships, and stationary bootstrap to test correlation between time series. For large-scale environmental effects, we used the Southern Oscillation Index (SOI) to represent the El Niño Southern Oscillation (ENSO); for local hydrographic conditions, we used sea surface temperature (SST), river runoff, and mixing conditions. Whereas the anchovy catch consisted of a northern species ( Engraulis japonicus ) and two southern species ( Encrasicholina heteroloba and Encrasicholina punctifer ), the magnitude of the anchovy catch appeared to be mainly determined by the strength of Eng. japonicus (Japanese anchovy). The main factor that caused the interannual variation of anchovy CPUE might change through time. The CPUE showed a negative correlation with combination of water temperature and river runoff before 1987 and a positive correlation with river runoff after 1988. Whereas a significant negative correlation between CPUE and ENSOs existed, this correlation was driven completely by the low-frequency ENSO events and explained only 10% of the variance. Several previous studies on this population emphasized that the fluctuations of larval anchovy abundance were determined by local SST. Our analyses indicated that such a correlation was transient and simply reflected ENSO signals. Recent advances in physical oceanography around Taiwan showed that the ENSOs reduced the strength of the Asian monsoon and thus weakened the China Coastal Current toward Taiwan. The decline of larval anchovy during ENSO may be due to reduced China Coastal Current, which is important in facilitating the spawning migration of the Japanese anchovy.     

华中地区主要绿肥在提高土壤肥力上的作用

1.紫云英与苕子的绿色体一般以初花期前后或盛花期增长最快。紫云英的根系主要分布在0—10厘米,在5,000斤鲜草产量时,1平方尺内约有6克左右的干根。地上与地下部分的干物质比为6.5:1,鲜重比为11:1,目前一般对地下部分的产量估计似乎有些偏高。2.紫云英等含氮、磷、钾的百分率均随绿色体的增长而减低,紫云英在盛花期含 N2.7%,P₂O₅ 0.65%,K₂O2.5%,CaO1.6%,含氮量与土壤的肥沃程度没有明显的相关性,含磷量与含钾量则与土壤中磷钾含量成正相关。根部所含的养分一般均低于地上部分,叶子的氮、磷百分率远较茎等部位为高。苕子盛花期含N3.3%左右,其他成分大体与紫云英相近。萝卜菜在盛花期的含N量为1.7%,K₂O 量较高,一般是N与P₂O₅的总和,含CaO量恒多于紫云英,一般在2.0%以上。油菜的成分大体与萝卜菜相近。3.各种绿肥在一定生长时期中地上部分的阳离子总量大体为一常数。紫云英在盛花期的阳离子总量维持在110毫当量左右,萝卜菜的含量还更高。4.萝卜菜、紫云英、苕子与小麦等四种植物对蛇纹石都能利用,但对钾长石不能利用。磷灰石的施用对增产很显著,根据增产百分率的大小,可排列成如下的次序:紫云英>萝卜菜>苕子>小麦。在某种程度上反映植物对难溶性物质的利用能力的三个指标(根的阳离子交换量、根的吸收面积与根的呼吸强度),对于四种植物,其大小次序基本上与其对磷灰石的利用能力的排列次序相一致。因此从各方面来看,这几种绿肥的吸收养分的能力,都较象小麦这样的农作物为强。5.绿肥是一种成本低收效大的肥料。在紫云英鲜草产量5,000斤时,地上与地下部分所合的氮、磷、钾分别相当于硫酸铵105斤、过磷酸钙22.5斤、氯化钾36斤。假定其中的氮素有2/3是来自大气,则“天然工厂”制造了70斤左右的硫酸铵。中稻亩产600斤时所取走的氮素约相当于50斤硫酸铵,因此单就来自大气中的这一部分来讲,对中稻的供应也还是有余。从全国范围来看,凡是绿肥面积大的地区,也就是稻麦产量高而稳定的地区。目前各地绿肥的种植面积与产量都极不平衡,还有很大的潜力。     

Pharmacokinetics and elimination of salicylic acid in rabbits

Sodium salicylate was administered to rabbits in order to compare its disposition with that in other major and minor agricultural species. A dose of 44 mg/kg was given orally (p.o.) or intravenously (i.v.), and plasma and urine samples were collected for 36 h and 96 h, respectively. The majority of the drug was excreted as salicylic acid (SA) within 12 h. The major metabolites following an oral dose were salicyluric acid (SUA) and the glucuronide conjugates of SA and SUA. Following i.v. dosing, sulfate conjugates of both SA and SUA were also evident. Both SA and SUA were detected in plasma. Following i.v. administration, SA was distributed with a Vss of 0.249 +/- 0.082 l/kg and cleared at a rate of 0.0432 +/- 0.006 l/h/kg. The biological half-life, calculated from the terminal disposition-rate constant, was 4.3 h (i.v.) or 9.7 h (p.o.). The urinary elimination pattern of SA and metabolites in the rabbit was similar to that previously reported by our laboratories for cattle and goats, although total recovery of the administered dose was not as high as for the latter two species. However, the volume of distribution was larger than for cattle and goats, and rabbits cleared the drug more slowly than those species. As a consequence, the biological half-life was eight to ten times longer than in the ruminants studied previously.     

The oxidative metabolism of fenbendazole: a comparative study

The oxidative metabolism of fenbendazole (FBZ) was studied in hepatic fractions prepared from livers of cattle, sheep, goats, chickens, ducks, turkeys, rats, rabbits and catfish. All species produced the sulfoxide metabolite (oxfendazole; FBZ-SO), and p-hydroxyfenbendazole (FBZ-OH) was produced by all species except sheep. The product of demethoxycarbonylation, fenbendazole amine (FBZ-NH2), was not produced by liver preparations of any species. A fourth metabolite, resulting from the further oxidation of oxfendazole, fenbendazole sulfone (FBZ-SO2), was formed in all species but at highly varying rates. The chicken exhibited the highest overall rate of FBZ metabolism, followed by the duck, goat, sheep, steer, catfish, rat, rabbit, and turkey. Considerable variation was evident among avian species, the duck and turkey produced substantially less of the FBZ-OH and FBZ-SO2 metabolites than the chicken. Catfish liver preparations formed equivalent amounts of metabolite at 25 degrees C and 37 degrees C incubation temperatures. The formation of the sulfone metabolite (FBZ-SO2), however, was practically nonexistent in catfish.     

Using coupled fish behavior–hydrodynamic model to investigate spawning migration of Japanese anchovy,Engraulis japonicus,from the East China Sea to Taiwan

Adult Japanese anchovies (Engraulis japonicus) migrate from the East China Sea to the coastal region of Taiwan to spawn around late winter and early spring and, later, their larvae constitute important fisheries in Taiwan. However, their migration route and its mechanism remain unclear. To investigate their spawning migration, we used a coupled fish behavior–hydrodynamic modeling approach. The physical field is simulated by the Pacific Ocean adaptation of the TaIwan Multi‐scale Community Ocean Model (TIMCOM) and the fish migration by Lagrangian tracer tracking with the aid of approximation of fish swimming behavior. We investigated three fish behavioral scenarios: (i) passive tracking of the current, (ii) swimming along with the current, and (iii) swimming along with the current and then changing to swimming toward the optimal spawning temperature. The comparison with and without Changjiang discharge is used to investigate the impacts of discharge reduction due to the Three Gorges Dam. Our results suggest that spawning migration of Japanese anchovy from the East China Sea to Taiwan may be aided by the China Coastal Current and that adult anchovies cannot reach the spawning site by passive advection alone. Thus, the swimming behavior of anchovies is crucial during the spawning migration, as it provides extra velocity and the orientation to the favorable spawning grounds. In addition, the adult anchovy is unlikely to reach the coastal area of Taiwan without Changjiang discharge. Our findings indicate that a coupled fish behavior–hydrodynamic model can help understand the influences of physical environment on the migration of Japanese anchovies.