Channel-forming action--a general property of venoms of spiders in the family Theridiidae (Aranei)

The study of venom action of 10 spider species of Theridiidae family has shown that they cause the formation of the cation selective channels on the bilayer lipid membranes. This action does not depend on the species sex and age and it is the important diagnostic characteristic of the family. The channel-forming effect is due to the presence of the peptide with molecular weight about 5000 daltons in venoms of Theridiidae spider family.     

Effect of oxaloacetic acid on hydrogen-calcium metabolism in mitochondria

It has been shown by using o-phthalic acid--a concurrent inhibitor of the transport of oxalacetic acid in mitochondria that the effect of the latter on the mechanism of 2H+/Ca2+-metabolism is realized at the inner side of the inner mitochondrial membrane. Oxalacetic acid was shown to induce not only the release of Ca2+ ions but also those of strontium and manganese accumulated in the mitochondria (100-150 nmol/mg of protein). Mechanism of the effect of oxalacetic acid on permeability of the mitochondria membranes are discussed.     

Resistance of various protein channels to proteolytic degradation

The influence of some proteolytic enzymes on the properties of the ionic channels induced in the lipid bilayer by three different toxic proteins was studied. It was found that pronase and trypsin did not decrease the conductance of the membranes modified by melittin, alpha-staphylotoxin and latrotoxin and changed its cation-anion selectivity. The dependence of melittin-channels selectivity on the medium pH was investigated. It was suggested that the carbonyl groups of peptide bond take part in defining cation selectivity of the melittin channel.     

Hypoderma actaeon: an emerging myiasis in roe deer (Capreolus capreolus)

Subcutaneous larvae of Hypoderma spp. (Diptera: Oestridae) were detected in the dorsal region in 10 roe deer, Capreolus capreolus (Artiodactyla: Cervidae), hunted in central Spain between January and March 2016. All larvae were found in the inner side of the hide during the skinning of the animals. The study of the morphological features of eight larvae of different stages collected from two animals allowed the identification of Hypoderma actaeon Brauer. The small size (4–5 mm) of some of the first instars suggests that the internal lifecycle of H. actaeon may be exclusively subcutaneous. This is the first confirmation of H. actaeon in roe deer; however, further studies to assess the spread of the parasite and to follow the evolution of this myiasis in roe deer are needed.     

Changes in the membrane surface charge and the potentiation of phospholipase A2 as affected by the cytotoxin from the venom of the Central Asian cobra

The interaction of iodine labelled cytotoxin of the middle-asian cobra venom with erythrocyte membranes has been studied. The pretreatment of erythrocytes by cytotoxin results in the sensitivity to the lytic action of pure phospholipase A2 of the same venom. Using I-labelled serum albumin it has been proved that cytotoxin promotes the binding of acid proteins on the membrane such as phospholipase A2 interacted with it synergetically. In the course of study of cytotoxin effect on the time of adhesion hemispheres of artificial bilayer phospholipide membranes it has been established that due to the basic properties cytotoxin neutralizes the negative charge of the membrane surface. This effect of cytotoxin plays an important role in the potentiation of membrane action of phospholipase A2.     

具size结构种群竞争系统的最优控制

研究基于size结构的种群模型的控制问题,利用特征线法给出了系统的形式解,由Banach不动点定理和Gronwall不等式推导了系统及其共轭系统的适定性,并依靠法锥相关知识证明了最优控制问题解的存在必要条件.