Enhanced toxicity of the immunosuppressant ovalicin upon application to the skin

The non-myelotoxic immunosuppressive sesquiterpene ovalicin, of fungal origin, is much more toxic when applied to the skin of animals than when injected i.v., the LD-50 in guinea pigs being 0.2 in the first case and 7 mg/kg in the second. It elicits aphagia and adipsia. It is assumed that ovalicin effects are due to slow, tissue-specific, metabolic toxification.     

Computing the variance of the forecast error for the holt-winters seasonal models

This paper presents expressions for the variance of the forecast error for arbitrary lead times for both the additive and multiplicative Holt-Winters seasonal forecasting models. It is shown that even when the smoothing constants are chosen to have values between zero and one, when the period is greater than four, the variance may not be finite for some values of the smoothing constants. In addition, the regions where the variance becomes infinite are almost the same for both models. These results are of importance for practitioners, who may choose values for the smoothing constants arbitrarily, or by searching on the unit cube for values which minimize the sum of the squared errors when fitting the model to a data set. It is also shown that the variance of the forecast error for the multiplicative model is nonstationary and periodic.     

An assessment of the economic value of non-linear foreign exchange rate forecasts

Recent research suggests that non-linear methods cannot improve the point forecasts of high-frequency exchange rates. These studies have been using standard forecasting criteria such as smallest mean squared error (MSE) and smallest mean absolute error (MAE). It is, however, premature to conclude from this evidence that non-linear forecasts of high-frequency financial returns are economically or statistically insignificant. We prove a proposition which implies that the standard forecasting criteria are not necessarily particularly suited for assessment of the economic value of predictions of non-linear processes where the predicted value and the prediction error may not be independently distributed. Adopting a simple non-linear forecasting procedure to 15 daily exchange rate series we find that although, when compared to simple random walk forecasts, all the non-linear forecasts give a higher MSE and MAE, when applied in a simple trading strategy these forecasts result in a higher mean return. It is also shown that the ranking of portfolio payoffs based on forecasts from a random walk, and linear and non-linear models, is closely related to a non-parametric test of market timing.     

Association of Golgi vesicles containing acid phosphatase with the chromatoid body of rat spermatids

The relationship between the Golgi apparatus and the small vesicles associated with the chromatoid body was investigated using a cytochemical technique. It was observed that in early spermatids, when the chromatoid body appears in close contact with the Golgi complex, and all through its migration to the caudal pole of the nucleus, some of the vesicles that accompany the organelle display acid phosphatase activity. It is concluded that these smooth vesicles originate in the Golgi apparatus.     

Inhibition of the regulatory ability of stomata caused by exhaust gases

Summary It is demonstrated that very low concentrations of exhaust gases from a combustion engine inhibit the regulatory ability of stomata. However, when gas treatment was stopped, plants showed a quick recovery of the ability to close stomata.     

Pharyngeal cavity and the gills are the target organ for the repellent action of pardaxin in shark

Pardaxin, an active principle of the repellent secretion of the Red Sea flatfish, Pardachirus marmoratus, elicited severe struggling, mouth paralysis, and transient increase in urea leakage from the gills only when administered to the medium bathing the shark's pharyngeal cavity and gills. An apparatus was constructed which prevents a mixing of the outflow from shark's gills with water bathing its surface skin. It is concluded that in sharks the gills and/or the pharyngeal cavity are the target organ for the repellent action of pardaxin.     

Increased formation of arginine deiminase by Clostridium perfringens FD-1 growing in the presence of caffeine

Caffeine slowed growth and markedly increased the formation of arginine deiminase in growing C. perfringens FD-1 when dextrin, but not maltose or maltotriose, served as the energy source. It is postulated that the ability of caffeine to induce arginine deiminase is related to an inhibition of polysaccharide utilization, resulting in a shift-down condition known to induce arginine deiminase and other enzymes in bacteria.     

Pharyngeal cavity and the gills are the target organ for the repellent action of pardaxin in shark

Summary Pardaxin, an active principle of the repellent secretion of the Red Sea flatfish,Pardachirus marmoratus, elicited severe struggling, mouth paralysis, and transient increase in urea leakage from the gills only when administered to the medium bathing the shark's pharyngeal cavity and gills. An apparatus was constructed which prevents a mixing of the outflow from shark's gills with water bathing its surface skin. It is concluded that in sharks the gills and/or the pharyngeal cavity are the target organ for the repellent action of pardaxin.     

Increased formation of arginine deiminase byClostridium perfringens FD-1 growing in the presence of caffeine

Summary Caffeine slowed growth and markedly increased the formation of arginine deiminase in growingC. perfringens FD-1 when dextrin, but not maltose or maltotriose, served as the energy source. It is postulated that the ability of caffeine to induce arginine deiminase is related to an inhibition of polysaccharide utilization, resulting in a shift-down condition known to induce arginine deiminase and other enzymes in bacteria.     

Effects of the metals,Be, Fe,Cu and Al,on the mobility of immunoglobulin receptors

Summary Cap formation in mouse spleen cells induced by antiimmunoglobulin was inhibited by the metals Be, Fe, Cu and Al. Be was especially strong as an inhibitor of cap formation. It is suggested that these metals might change the mobility of the membrane and have some biological effects on the cross association of antigen receptors when B lymphocytes are attached by them.     

Oxygen permeability of the chorion in relation to diapause termination in Bombyx eggs

Oxygen permeability of the chorion of the silkworm, Bombyx mori, was measured in relation to embryonic diapause. It did not change appreciably when the eggs were freed from diapause by being kept under long chilling. This finding suggests that the increase in oxygen permeability of the chorion is not a pre-requisite for the termination of the diapause and resynthesis of glycogen from 2 polyols.     

Combining exchange rate forecasts: What is the optimal consensus measure?

In this paper a high-quality disaggregate database is utilized to examine whether individual forecasters produce efficient exchange rate predictions and also if the properties of the forecasts change when they are combined. The paper links a number of themes in the exchange rate literature and examines various methods of forecast combination. It is demonstrated, inter alia, that some forecasters are better than others, but that most are not as good as a naive no-change prediction. Combining forecasts adds to the accuracy of the predictions, but the gains mainly reflect the removal of systematic and unstable bias.     

The use of liposomes in the investigation of mechanisms of asbestos damage

Asbestos-induced cell damage is initiated by a reaction at the plasma membrane. The effect of chrysotile (which is more hemolytic and releases more silicic acid than other types of asbestos) on permeability changes of liposomes has been investigated. The destabilizing effect rises when the amount of chrysotile is increased. Silicon dioxide is one major constituent which could be a hemolytic agent, and a cause of damage. It also caused an increase of permeability of liposomes.     

Specific phosphorylation of a calf serum protein by a kinase from the cell surface]

A protein of molecular weight approximately 200,000, which exists in trace amounts in calf serum, is specifically phosphorylated by an enzyme located at the surface of cultured cells. The emzymatic reaction utilizes ATP, is enhanced by Mg++ and Zn++ ions, and is not dependent on cyclic AMP. This kinase activity is associated with normal growing fibroblasts but disappears when they are contact-inhibited. It remains high, however, in transformed and malignant cells, whatever their growth state.     

基于市场竞争程度的古诺与斯坦克尔伯格博弈对比分析

建立了多厂商古诺博弈和m个先动厂商、n—m个后动厂商的多厂商新坦克尔伯格博弈，分析了先动厂商竞争程度对其均衡产量和利润的影响情况。结果表明，当先动厂商竞争程度较小时，古诺厂商利润小于斯坦克尔伯格先动厂商利润；当先动厂商竞争程度较大时，古诺厂商利润大于斯坦克尔值格先动厂商利润。     

从造纸术摇篮到造纸工业现代化

众所周知，我国是造纸术的摇篮。造纸术的外传曾经一度起到促进世界文化发展的作用。然而，我国却经历了数百年的历程，机制纸才开始取代手工造纸，事实上，我国造纸工业是在中华人民共和国成立后，才开始阔步前进，并在1993年其纸和纸板总产量跃居世界主要产纸国家第三位。然而，人均消费量依然仅有36公斤，远远落后于世界平均水平的50公斤。为了促进我国造纸工业的现代化和健康发展，今后务必着眼于可持续纤维原料的开发和利用，认真执行清洁生产和质量第一的技术路线。这就意味着有必要在纤维原料中增加木材的份额。与此同时，又必须妥善处理工厂排污（特别是蒸煮废渣的处理），务使取得更好的环境保护效果。不言而喻，也就更有必要加强科研与开发工作，针对我国纤维原料的特点有所创新，并做到在实际生产中得到兑现。     

Laboratory observations on pupae on the medflyCeratitis capitata (Wied.)

Summary Laboratory observations on pupae ofCeratitis capitata showed that most adult emergence took place in the morning between 06.00 and 09.00 h. Pupae succeeded to emerge when covered with sand up to a depth of 30 cm. It was not possible to differentiate between sexes by pupal weight.     

Epicatechin can cause the seedling growth inhibitor,nagilactone E,to induce growth stimulation

Summary A possible new role for the flavonoid (–)-epicatechin (II) is described. It has no growth effects on its own, but when it is added to lettuce and rice seeds together with the known seedling growth inhibitor nagilactone E (I), the growth inhibitor activity ofI can cease and growth stimulation can be observed.     

基于虚拟样机技术的铝电解多功能大车运行水平侧向力研究分析

在虚拟样机技术的基础上，分析了电解铝多功能大车运行时的水平侧向力的问题。电解铝多功能由于其本身重量较大，在运行工程中会产生极大的水平惯性力，本文运用虚拟样机技术，分析研究了电解铝多功能大车运行的各工况的水平偏载荷，并和设计计算相结合进行相互验证，得出分析是真实可行的。     

Olfactory receptor trafficking to the plasma membrane

Olfactory receptors typically exhibit poor plasma membrane localization and functionality when heterologously expressed in most cell types. It has therefore proven difficult to effectively study olfactory receptor pharmacology and signaling mechanisms using traditional cell culture systems. Over the past few years, a variety of distinct proteins have been reported to interact with olfactory receptors and facilitate olfactory receptor trafficking to the plasma membrane in heterologous cells. Advances in this area have shed significant light on the fundamental factors governing the cell-specific control of olfactory receptor trafficking.