The ovary ofRaphidia flavipes is telotrophic and of theSialis type (Insecta,Raphidioptera)

Summary The morphology and ultrastructure of the ovarioles ofRaphidia flavipes are described. The ovary ofRaphidia shows all the structural elements by which the telotrophic ovarioles of Megaloptera can be distinguished easily from those of polyphage Coleoptera or Hemiptera. This supports the view of sister-group relationship between the Raphididae and the Sialidae.Dedicated to Professor Dr. Dr. h.c. Bernhard Rensch on the occasion of his 80th birthdayThis investigation was supported in part by the Stiftung Volkswagenwerk     

细菌分裂蛋白及FtsZ抑制剂的研究进展

近年来,由于抗生素的滥用,耐药性细菌广泛出现,对人体健康的威胁日益严峻.随着临床用药的选择不断减少,迫切需要开发新的抗菌药物,特别是新作用机制的抗菌分子来对抗出现的耐药菌.细胞分裂温度敏感.突变体Z (filamenting temperature-setnsitive mutant Z,FtsZ)作为细菌分裂的必需蛋白质,是目前研究最热门的作用靶点之一.FtsZ是一高度保守的蛋白质,在大多数原核细胞的细胞分裂中发挥着关键作用,本文回顾了细菌分裂蛋白的结构特点及其生物学功能,并综述了以FtsZ为靶点的抗菌药物研究的进展.     

Interrelationship between pH, plasma potassium concentration and ventilation during intense continuous exercise in man

During resting conditions plasma hydrogen ion concentration ([H+]P) is known to influence ventilation (VE), whereas the control of plasma potassium concentration ([K+]P) at rest and of both [K+]P and VE during exercise are controversial issues. To obtain more information about these variables during muscular work, eight trained men performed two successive intense continuous cycle-ergometer tests, the first (test I) during metabolic acidosis, the second (test II) with an alkalotic pH. No correlation was found between [H+]P and [K+]P or VE in the direction of change of these variables in test I. Furthermore, no correlation between [H+]P and [K+]P in test I and II was seen. Instead [K+]P and VE changed in relation to the exercise intensity. We suggest that the results confirm [K+]P as an indicator of muscular stress. In addition, the similar behaviour of relative values of [K+]P and VE changes in test I (r = 0.9, m = 1.0, where m is the slope of the regression curve) supports the hypothesis that extracellular potassium controls VE and thereby [H+]P also.     

Ichnostratigraphic correlation of Lower Palaeozoic clastics in the Kufra Basin (SE Libya)

The Lower Palaeozoic deposits in North Africa are dominated by sandstones and shales which often lack biostratigraphically useful body fossils. Trilobite burrows ( Cruziana ) partly fill this gap and provide the basis for medium-resolution stratigraphic interpretations. Several Ordovician-Silurian ichnostratigraphically significant Cruziana forms have been found and studied in the Kufra Basin (SE Libya), including C. goldfussi and C. furcifera from the Lower Ordovician Hawaz Fm. and a new ichnospecies, C. kufraensis , occurring in transgressive sandstones at the base of the Lower Silurian Tanezzuft Fm. The upper Tanezzuft Fm. and Akakus Fm. typically contain C. acacensis , a form that is characteristic of the Lower Silurian of Northern Gondwana.     

Galaxy-ML: An accessible,reproducible, and scalable machine learning toolkit for biomedicine

Supervised machine learning is an essential but difficult to use approach in biomedical data analysis. The Galaxy-ML toolkit (https://galaxyproject.org/community/machine-learning/) makes supervised machine learning more accessible to biomedical scientists by enabling them to perform end-to-end reproducible machine learning analyses at large scale using only a web browser. Galaxy-ML extends Galaxy (https://galaxyproject.org), a biomedical computational workbench used by tens of thousands of scientists across the world, with a suite of tools for all aspects of supervised machine learning.

This is a PLOS Computational Biology Software paper.

     

High affinity (3H)tryptamine binding sites in various organs of the rat

(3H)Tryptamine binds with high affinity (KD values around 4 nmol/l) to membranes from different organs of the rat. The number of binding sites was high in the liver, intermediate in the heart and cerebral cortex and low in other organs including ileum, kidney, spleen, stomach and lung. Binding to kidney membranes was investigated in more detail. It was rapid and reversible (t1/2 7 min.). The structure-activity profile was characterized by high affinity of some beta-carbolines (IC50 = 20 - 200 nmol/l), medium affinity of serotonin (IC50 = 858 nmol/l) and low of methysergide (IC50 greater than 20 mumol/l). The findings correlate very well with binding characteristics to cerebral cortex membranes. Therefore, rat brain cortex and other organs contain the same type of (3H)tryptamine binding site and may be equally appropriate for further analysis.     

Strain accommodation in the zygomatic arch of the pig: A validation study using digital speckle pattern interferometry and finite element analysis

It has been repeatedly suggested that mammalian cranial sutures act not only to allow growth but also to reduce the levels of strain experienced by the skull during feeding. However, because of the added complexity they introduce, sutures are rarely included in finite element (FE) models, despite their potential to influence strain results. Because sutures present different morphologies and with differing degrees of internal fusion, many different methods of modeling may be necessary to accurately measure strain environments. Alternatively, these variables may exert very little influence on the scale of a whole‐skull model. To validate suture modeling methods, four alternative ways of including a suture in 3D FE models of the pig zygomatic arch were considered and compared with ex vivo experimental data from digital speckle pattern interferometry (DSPI). The use of DSPI rather than traditional strain gauge techniques allows strain gradients around the suture as well as the motions of the two bones to be observed. Results show that the introduction of 3D elements assigned more compliant material properties than the surrounding bone, is the most effective way of modeling both morphologies of suture, both in tension and compression. However, models containing no suture are almost indistinguishable from these compliant suture models, beyond the high strain gradient immediately adjacent to the suture. Conversely, modeling the suture as an open break in the mesh, or with spring elements assigned suture properties, fails to reproduce the experiment. Thus, although a solid but flexible model of sutures is preferred, the similarity between these models and those without sutures tentatively suggests that such extra detail may be unnecessary in pigs if the behavior of the whole skull is of interest. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.