An insect antifreeze protein from Anatolica polita enhances the cryoprotection of Xenopus laevis eggs and embryos

Cryoprotection is of interest in many fields of research, necessitating a greater understanding of different cryoprotective agents. Antifreeze proteins have been identified that have the ability to confer cryoprotection in certain organisms. Antifreeze proteins are an evolutionary adaptation that contributes to the freeze resistance of certain fish, insects, bacteria, and plants. These proteins adsorb to an ice crystal's surface and restrict its growth within a certain temperature range. We investigated the ability of an antifreeze protein from the desert beetle Anatolica polita, ApAFP752, to confer cryoprotection in the frog Xenopus laevis. X. laevis eggs and embryos microinjected with ApAFP752 exhibited reduced damage and increased survival after a freeze/thaw cycle in a concentration-dependent manner. We also demonstrate that ApAFP752 localizes to the plasma membrane in eggs and embryonic blastomeres and is not toxic for early development. These studies show the potential of an insect antifreeze protein to confer cryoprotection in amphibian eggs and embryos.

Adaptive Performance of Five Varieties of Hybrid Citrus in Jingzhou Area Hubei Province

In order to understand the growth habits and freeze resistance of the hybrid citrus variety in Jingzhou area, and to provide reference for the introduction of the variety in fruit farmers, and to promote the development of the local citrus industry, the main biological and freeze resistance characteristics of the five hybrid citrus variety were investigated. The results showed that:(1)The growth potential of ‘Wo gan’ and ‘Daya’ were the strongest, followed by ‘Aiyuan 38’ and ‘Chunjian’, and the weakest growth was ‘Buzhihuo’;(2) On the performance of summer and autumn shoots, ‘Daya’ and ‘Wogan’ were the longest, ‘Chunjian’ was moderate, ‘Aiyuan 38’ and ‘Buzhihuo’ were the weakest; (3) On the aspect of freeze resistance, ‘Aiyuan 38’was the strongest, followed by ‘Daya’ and ‘Wogan’, the freeze resistance of ‘Chunjian’ was more weak and ‘Buzhihuo’ was the weakest;(4) On the other aspects, such as the leaf shape, leaf size, color of tender leaf, thorn density, flower size, inflorescence and so on also had the big difference, but the petal number and the petal color were similar. It could be seen that ‘Daya’ and ‘Wogan’ had the best growth potential in Jingzhou area, but their freeze resistance were weak. The growth potential of ‘Aiyuan 38’ and ‘Chunjian’ were in the middle, ‘Aiyuan 38’ had best freeze resistance. The growth potential and freeze resistance of ’Buzhihuo’ in Jinzhou area was the weakest.

Selected Properties of Clay-Ash Composite Containing Bottom Ash from Combustion of Wood - Coconut Shells Biomass

In this article, the influence of the addition of the bottom ash to clay on the selected physical and mechanical properties of ceramic composite are discussed. The biomass (80% wood with the addition of 20% coconut shells) was combustion in the fluidised-bed boiler. The tests were carried out on the samples, in which the contents of bottom ash in relation to clay ranged from 5 to 15%. The absorbability, open porosity, apparent density, compression strength and freeze resistance have been determined. The obtained test results indicate that the increase of this bottom ash in clay-ash composite causes the increase of open porosity, absorbability and compression strength, but a reduction in resistance against frost attract.

Present and perspective cultivars of Syringa L. for greening the city of Novosibirsk

There is a need to correct a historical imbalance of ornamental shrubs and, in particular, hybrids and cultivars of genus Syringa L. in the city of Novosibirsk. Recent ambitious projects of reconstruction of the present green areas and creating the new ones have enhanced the relevance of testing the cultivars which have been conducted at the CSBG SB RAS for 35 years. In order to study further the features of biology and freeze resistance under continental climate of the south of West Siberia, CSBG’s collection was completed with 54 new samples of cultivars of genus Syringa from 5 botanical institutions and nursery gardens located in the different climatic zones.

Comparison of physical and mechanical properties of mining waste with a grain size up to 2 mm reinforced with cement CEM I and CEM III

The article presents the results of tests for mining waste mixtures - cement. The addition of cement was aimed at limiting the leaching of fine particles and improving physical and mechanical parameters. The studies used cement CEM I 42.5 R and CEM III/ A 42.5N - LH / HSR / NA and plasticizing sealant. The paper presents the results of freeze resistance, swelling tests, pH of water leachate and oedometer soil testing.

Effect of basalt powder addition on properties of mortar

The study evaluates the use of waste basalt powder as a replacement of cement to enhance hydration of cement and mortar properties. The basalt powder is a waste resulting from preparation of aggregate used in asphalt mixture production. Previous studies have shown that analysed waste used as a fine aggregate replacement has a beneficial effect on some properties of mortar and concrete, i.e. compressive strength, flexural strength and freeze resistance. The present study shows the results of the research concerning the modification of cement paste and mortar with basalt powder. The modification consists in adding the powder waste as a partial replacement of cement. The percentages of basalt powder in this research are 0-40% and 0-20% by mass of cement in the pastes and mortars respectively. The experiments were carried out to determine the influence of basalt powder on cement hydration, as well as compressive and flexural strength. Results indicate that addition of basalt powder as a replacement of cement leads to deterioration of compressive strength. The flexural strength of mortar is improved in some cases. Waste basalt powder only slightly influences the cement hydration.

Results of the freeze resistance test, swelling index and coefficient of permeability of finegrained mining waste reinforced with cements

The article presents the result of laboratory tests for mining waste with grain size of 0 to 2 mm stabilized with cement. Used for stabilization of cement CEM I 42.5 R and blast furnace cement CEM III / A 42.5N - LH / HSR / NA and a plasticizer sealant. Cement was added to the mining waste test in the proportions of 5 - 8% in relation to the skeleton's weight. For the cemented samples, the freeze resistance test, swelling index, coefficient of permeability and pH of water leachate were tested. The addition of a cement binder resulted in diminishing the water permeability of mining waste and limiting the leaching of fine particles from the material.

Processing of exterior light concrete wall panels

The characteristics of wall panels, the facing element of which is porous concrete, are given. For exterior wall panels, laboratory suggested the exposed porous concrete of grades B7,5 and B10 based on white and grey cements M400. As aggregates, one uses limestone and granite mined in the corresponding quarry. Air-entangling additives are applied in concrete manufacturing, due to which placeability of concrete mix is improved and volumetric weight of concrete is reduced. In its turn, it allowed reducing water absorption and enhancing freeze resistance of products. Presence of fine-splitted air in formation of closed pores (pore forming) improves the structure of exposed concrete, bringing its properties closer to the ones of porous claydite-concrete as the essential material of exterior wall panel. Homogeneity of concrete by durability came to 0,70 with variability coefficient equal to 0,11, what exceeds regulatory requirements. Its factory features and way of production are indicated. The range of application and the actual cost of such panels are identified.