Effect of Banana Bunchy Top Virus on the Heat Shock Protein Genes of Pentalonia nigronervosa during Temperature Susceptibility and Its Effect on Virus Transmission

Acquisition of plant viruses is known to exert various effects on vectors’ developmental biology. Pentalonia nigronervosa is the only known vector of banana bunchy top virus (BBTV), which is an economically detrimental virus infecting banana cultivars all over the world. In the present study, the developmental biology of viruliferous (Vr) and non-viruliferous (NVr) aphids was compared, with a marked reduction noted in the lifespan of aphids upon acquisition of BBTV. Among all the environmental parameters temperature is an important determinant of an insect’s abundance and geographical distribution. Temperature susceptibility of P. nigronervosa was scrutinized by comparing the mortality percentage and differential expression pattern of three heat shock proteins (Hsps; Hsp40, Hsp70, and Hsp90) at the mRNA level between NVr and Vr aphids. After exposure to different temperature stress (5 °C, 15 °C, 38 °C and 25 °C as control) highest mortality of Vr aphids were recorded at 5 °C. Analysis of expression levels of Hsp genes using qPCR showed that both cold and heat shock treatment stimulated higher expression of the three Hsps at various rates in Vr than NVr aphids.. Finally, the effect of temperature stress on the BBTV titer level and their transmission by P.nigronervosa was determined by absolute quantification. The transmission efficiency along with the virus titer was found to be the lowest at 15 °C compared to 38 °C. Overall, our results provide a novel insight into the intricate interaction between aphid fitness and thermal stress concerning the acquisition and transmission of BBTV, which could be a roadmap for the future epidemiological control system.

Research on Aging Performance of AH-90 and PG70-28SBS Modified Asphalt

This paper studied the aging effect of the rolling thin film oven test (RTFOT) , pressurized aging vessel (PAV) and natural ultraviolet radiation aging method on AH-90 and PG70-28 asphalts. penetration degree , penetration degree index,softening point and ductility tests were used to evaluate the high temperature stability, low temperature split and temperature susceptibility of the two aged asphalts , it is pointed that the aging damaged the low temperature performance of the asphalts, improved the high temperature stability and the temperature susceptibility of the asphalts. Compared with the AH-90 asphalt, PG70-28 modified asphalt has better aging performance. The antiaging property and temperature susceptibility of two asphalts after ultraviolet photooxidation and thermal oxidation , were investigated by testing their viscosity index , antiaging index. which indicated that the viscosity index is correlative nearly with the penetration degree index and the influence of 10.5 kJ·cm-2 ultraviolet photooxidation on asphalt performance is more serious than PAV thermal oxidation. The results indicate that ultraviolet photooxidation research on asphalt is necessary in the intensive ultraviolet radiation region of Neimeng.

Rheological Characterization of Emulsified Bitumen from Industrial Waste

Emulsified bitumen is an aqueous mixture of bitumen and can be used in insulation and coating applications. In this study, used automotive oil was utilized as a component in bitumen emulsion formulation. Five formulations of bitumen emulsion comprising different ratios of neat bitumen and recycled automotive oil were formulated, namely EMB01–EMB05. The formulation utilized 1 g of abietic acid (C20H30O2) as an emulsifier. The formulated bitumen was characterized for penetration, softening point, differential scanning calorimetry, viscosity, and oscillatory test, and the results were compared to commercial bitumen emulsion (ATLAS bitumen emulsion). The results show that EMB05 has softer consistency, high viscosity, temperature susceptibility, higher thermal stability, and an adaptable viscoelastic range compared to other formulations that provide suitable properties for coating and insulation of wall waterproof material.

OVERVIEW OF BITUMEN BINDERS USED IN UKRAINE

Introduction. Pavement bitumen is one of general road construction materials that are used for pavement construction. The quality of bitumen binder regulates specific technical and operational characteristics of asphalt pavements and their durability Problem Statement. Nowadays in Ukraine only one refinery plant produces pavement bitumen. The volume of its production is not enough to completely satisfy the demands of Ukrainian road construction industry. Due this a lot of binders in Ukraine are imported from other countries. In recent years the highest volumes of bitumen was imported from Republic of Belarus and Poland. In 2020 the amount of road construction works was increased, particularly with pavement repairing and new pavement constructing. It resulted in increasing in need in pavement bitumen that led not only to the high volume of import bitumen but to an expansion of the list of importing counties. Purpose. The presented study is aimed on analysis of quality of bitumen imported in Ukraine from eight countries. For these binders their features are obtained and problem of their applicability and its advisability in Ukraine road industry is considered. Materials and methods. As a material of research bitumens produced in Azerbaijan, the Republic of Belarus, Greece, Spain, Italy, Poland, Turkey and Ukraine are chosen. The standard quality properties are obtained in accordance with the actual in Ukraine standards ДСТУ 4044 and ДСТУ EN 12591. Beside this the attention is paid to the finding of fundamental properties of these binders, such as adhesion, cohesion and viscosity. Results. With the experimental data it is found that all bitumens significantly differ in their structural type. It results in differences in softening point and breaking point temperatures at the equal penetration value (this difference is in the range from 4.5 °С for the closer values to 16.5 °С for the most distinct values). This fact can influence on asphalt pavement properties and durability. Besides such a difference in a temperature susceptibility of binders their adhesion and cohesion properties differ too. Bitumen that tends to sol type of structure is characterized with higher cohesion and viscosity values. This peculiarity must be taken into account in mixing and compaction operations for the asphalts with such bitumen. The temperatures of these operations must be higher than one for bitumen close to the gel type. The low temperature susceptibility and wide plasticity interval are the advantages of bitumen that tends to gel type of structure. Conclusions. All bitumens that are imported in Ukraine must be certificated with ДСТУ 4044:2019 national standard requirements. Also they must be tested with additional methods to validate the decision on their implementation in road construction industry and to specify the implementation area. Keywords: paving bitumen, bitumen binder, penetration, softening point temperature, adhesion, cohesion, viscosity

Assessment Resistance Potential to Moisture Damage and Rutting for HMA Mixtures Reinforced by Steel Fibers

Rutting is mainly referring to pavement permanent deformation, it is a major problem for flexible pavement and it is a complicated process and highly observed along with many segments of asphalt pavement in Iraq. The occurrence of this defect is related to several variables such as elevated temperatures and high wheel loads. Studying effective methods to reduce rutting distress is of great significance for providing a safe and along-life road. The asphalt mixture used to be modified by adding different types of additives. The addition of additives typically excesses stiffness, improves temperature susceptibility, and reduces moisture sensitivity. For this work, steel fibres have been used for modifying asphalt mixture as they incorporated in the specimens by three percentages designated as 0.5, 1.0 and 1.5 % by the weight of asphalt mixture. The evaluation process based on conducting Marshall Test, Compressive strength test, and the wheel tracking test. The optimum asphalt content was determined for asphalt mixture. The results of the Marshall quotient and the index of retained strength of modified mixtures were increased by 44.0 and 17.38% respectively with adding 1.0% of steel fibres compared with the conventional mixture. The rut depth and dynamic stability were determined by using a wheel tracking test at two various testing temperatures of 45 and 55°C and two applied stresses of 70 and 80 psi. Results show that adding 1% of steel fibres to asphalt mixtures is very effective in increase the rutting resistance and reduce moisture damage.

Characterizing the Fused TvG6PD::6PGL Protein from the Protozoan Trichomonas vaginalis, and Effects of the NADP+ Molecule on Enzyme Stability

This report describes a functional and structural analysis of fused glucose-6-phosphate dehydrogenase dehydrogenase-phosphogluconolactonase protein from the protozoan Trichomonas vaginalis (T. vaginalis). The glucose-6-phosphate dehydrogenase (g6pd) gene from T. vaginalis was isolated by PCR and the sequence of the product showed that is fused with 6pgl gene. The fused Tvg6pd::6pgl gene was cloned and overexpressed in a heterologous system. The recombinant protein was purified by affinity chromatography, and the oligomeric state of the TvG6PD::6PGL protein was found as tetramer, with an optimal pH of 8.0. The kinetic parameters for the G6PD domain were determined using glucose-6-phosphate (G6P) and nicotinamide adenine dinucleotide phosphate (NADP+) as substrates. Biochemical assays as the effects of temperature, susceptibility to trypsin digestion, and analysis of hydrochloride of guanidine on protein stability in the presence or absence of NADP+ were performed. These results revealed that the protein becomes more stable in the presence of the NADP+. In addition, we determined the dissociation constant for the binding (Kd) of NADP+ in the protein and suggests the possible structural site in the fused TvG6PD::6PGL protein. Finally, computational modeling studies were performed to obtain an approximation of the structure of TvG6PD::6PGL. The generated model showed differences with the GlG6PD::6PGL protein (even more so with human G6PD) despite both being fused.