Attributes associated with probability of infestation by the pi?on ips, Ips confusus (Coleoptera: Scolytidae), in pi?on pine, Pinus edulis

We examined attributes of pi?on pine ( Pinus edulis ) associated with the probability of infestation by pi?on ips ( Ips confuses ) in an outbreak in the Coconino National Forest, Arizona. We used data collected from 87 plots, 59 infested and 28 uninfested, and a logistic regression approach to estimate the probability of infestation based on plot and tree-level attributes. Pi?on pine stand density index was a good predictor of the likelihood of infestation by pi?on ips at the plot level, and a cross-validation analysis confirmed that the model correctly classified 82% of the cases. Diameter at root collar and pi?on dwarf mistletoe infestation level were good predictors of individual tree infestation, and a cross-validation analysis indicated that the model correctly classified 72% of the cases. Results suggest that the occurrence of pi?on ips infestations may be related to stress factors associated with increased stocking and pi?on dwarf mistletoe infestations.     

Banach空间中的广义p正常算子

本文是在文献[4]基础上利用广义半内积空间的理论引入Banach空间上的广义p正常算子T=A+iB,AB-BA=0,其中A,B是广义p自共轭算子;同时还引入广义p正常算子的对偶算子T~*=A-iB及广义p酉算子,并就这些算子的有关谱进行了讨论。     

The development of the Neurath principle: unearthing the Romantic link

Otto Neurath’s thoroughgoing anti-foundationalism is connected to the recognition that protocol sentences are not inviolable, that is they are fallible and their choice cannot be determined: ‘Poincaré, Duhem and others have adequately shown that even if we have agreed on the protocol statements, there is a not limited number of equally applicable, possible systems of hypotheses. We have extended this tenet of the uncertainty of systems of hypotheses to all statements, including protocol statements that are alterable in principle’ (Neurath, 1983, p. 105). Later historiography has called Neurath’s extension of Duhemian holism the Neurath principle. Based on a study of Neurath’s early works on the history of optics, the paper investigates a previously unnoticed influence on the development of this principle, Neurath’s reading of Goethe’s Theory of colours. The historical and polemical parts of Goethe’s tripartite book provided Neurath with ideal examples for the vertical extension of Duhem’s thesis to observation statements. Moreover, Goethe’s critique of the language of science and his views on the theory-ladenness of observation, as well as on the history of science show strong parallels to many of Neurath’s ideas. These demonstrate the existence of surprisingly direct textual links between Romantic views on science and the development of twentieth-century philosophy of science. Neurath’s usage of Goethe’s examples also indicates that the birth of the Neurath principle is more tightly connected to actual scientific practice than to theory-testing, and that by admitting the theory-ladenness of observation reports and fallibility of protocol statements Neurath does not throw empiricism overboard.     

对国外一种大范围、宽滞回带电压监控器的性能分析和改进

分析进口电压监控器的电路性能 ,发现电压适应范围小、无过流保护、可视性低等设计缺陷及实际应用的局限性 .根据工厂实际供电情况 ,应用常用元件 ,对之进行了改进 ,提高了该产品对电源电压波动的适应性和运行稳定性 .根据进口电压监控器的电路及其实现 ,提出了改进国产欠电压继电器的方法     

Proteasomes in apoptosis: villains or guardians?

The proteasome (multicatalytic proteinase complex, prosome) is a major cytoplasmic proteolytic enzyme, responsible for degradation of the vast majority of intracellular proteins. Proteins degraded by the proteasome are usually tagged with multiple ubiquitin moieties, conjugated to the substrates by a complicated cascade of enzymes. Over the last years, evidence has accumulated that changes in the expression and activity of the different components of the ubiquitin-proteasome system occur during apoptosis. Proteasome inhibitors have been used to induce apoptosis in various cell types, whereas in others, these compounds were able to prevent apoptosis induced by different stimuli. The proteasome mediated step(s) in apoptosis is located upstream of mitochondrial changes and caspase activation, and can involve in different systems Bcl-2, Jun N-terminal kinase, heat shock proteins, Myc, p53, polyamines and other factors.