New Sivapithecus humeri from Pakistan and the relationship of Sivapithecus and Pongo

New humeri of two species of the Miocene hominoid Sivapithecus are described from near Chinji in Pakistan from between approximately 9 and 11 Myr ago. Sivapithecus, a middle and late Miocene hominoid from Turkey and Indo-Pakistan, is overall unlike any living hominoid, although facial-palatal similarities to the extant orangoutan, Pongo, have been used to support a hypothesis of close relationship. Living hominoids have postcranial similarities assumed to be shared derived, among them features of the proximal humerus. However, the new Sivapithecus proximal humeri differ from those of living hominoids, supporting an alternative hypothesis in which Sivapithecus and Pongo are not closely related. It is not clear how to choose between these incompatible hypotheses.     

On the Complexity of Ordinal Clustering

Given a set of pairwise distances on a set of n points, constructing an edgeweighted tree whose leaves are these n points such that the tree distances would mimic the original distances under some criteria is a fundamental problem. One such criterion is to preserve the ordinal relation between the pairwise distances. The ordinal relation can be of the form of total order on the distances or it can be some partial order specified on the pairwise distances. We show that the problem of finding a weighted tree, if it exists, which would preserve the total order on pairwise distances is NP-hard. We also show the NP-hardness of the problem of finding a weighted tree which would preserve a particular kind of partial order called a triangle order, one of the most fundamental partial orders considered in computational biology.     

用于化学实验温度测量的精密测温仪制作

本文主要详细阐述了精密测温仪的制作和使用。     

Inhibition of phosphodiesterase activity of human spermatozoa by spermine

Summary Sperm motility and metabolism are dependent upon the levels of cyclic AMP. Our studies have demonstrated that spermine by inhibiting sperm phosphodiesterase activity could regulate sperm physiology.     

A modified vital staining technique for amphibian eggs

Zusammenfassung Es wird eine Methode beschrieben, die es ermöglicht, mit Hilfe eines gefärbten Agarfilms, der durch Löcher in Stanniolpapier gepresst wird, am Amphibien-Ei regelmässige Reihen von Vitalfarbmarken zu setzen.     

阳离子淀粉CST制备及脱色性能研究

研究了在基本干的反应条件下制备阳离子淀粉的方法及其脱色性能,确定了用氢氧化钠作催化剂时的最佳反应条件。     

Identification of the V factor needed for synthesis of the iron-molybdenum cofactor of nitrogenase as homocitrate

Nitrogenase catalyses the ATP-dependent reduction of N2 to NH3, and is composed of two proteins, dinitrogenase (MoFe protein or component I) and dinitrogenase reductase (Fe protein or component II). Dinitrogenase contains a unique prosthetic group (iron-molybdenum cofactor, FeMoco) comprised of Fe, Mo and S, which has been proposed as the site of N2 reduction. Biochemical and genetic studies of Nif- (nitrogen fixation) mutants of Klebsiella pneumoniae which are defective in nitrogen fixation, have shown that the nifB, nifQ, nifN, nifE and nifV genes are required for the biosynthesis of FeMo-co. Recently, a system for in vitro synthesis of FeMoco was described. The assay requires at least the nifB, nifN and nifE gene products, and a low-molecular-weight factor (V factor) produced in the presence of the nifV gene product. We have used this system to study FeMoco biosynthesis. We report here the isolation of V factor and identify it as homocitric acid ([R]2-hydroxy-1,2,4-butanetricarboxylic acid).     

Glucose-6-phosphatase activity in experimental tuberculosis and following isoniazid treatment

Zusammenfassung Bei den tuberkulösen Meerschweinchen wurde in der Niere eine erhöhte Aktivität der Glukose-6-Phosphatase beobachtet. Isoniazid hat die erhöhte Aktivität des Enzyms nicht erniedrigt, wenn es tuberkulösen Tieren vom 8. bis zum 38. Tage nach der Infektion oral verabreicht wurde. Es wird angenommen, dass die erhöhte Aktivität Ausdruck der Adaptionsfähigkeit von Glukose-6-Phosphatase ist.

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Galesburg State Research Hospital, Galesburg, Illinois, USA.     

Toxic effect of cadmium nitrate on the liver of Channa punctatus.

Exposure of a fresh water fish, Channa punctatus, in a medium containing as low as 0.01 ppm of cadmium nitrate, resulted in the necrosis of hepatic cells. A temporary recovery of these cells was however observed when the animals were exposed to lower concentrations.