Epistasis in Predator-Prey Relationships

Epistasis is the interaction between two or more genes to control a single phenotype. We model epistasis of the prey in a two-locus two-allele problem in a basic predator-prey relationship. The resulting model allows us to examine both population sizes as well as genotypic and phenotypic frequencies. In the context of several numerical examples, we show that if epistasis results in an undesirable or desirable phenotype in the prey by making the particular genotype more or less susceptible to the predator or dangerous to the predator, elimination of undesirable phenotypes and then genotypes occurs

Кількісне визначення оксациліну методами кінетико-спектрофотометрії та окисно-відновного титрування

The search for new analytical reactions and finding out the optimal conditions for their course, which can be used as the basis for quantitative analytical determinations of penicillins, is a very urgent task.Aim. To develop methods for the quantitative determination of Oxacillin.Materials and methods. The study object was Oxacillin sodium salt powder in vials for preparing a solution for injections(0.5 g). Peroxomonosulfate acid as triple potassium salt 2КНSO5∙КНSO4∙K2SO4 (Oxone®) of “extra pure” grade was used as an oxidant. The methods of kinetic spectriphotometry and redox titration were used.Results and discussion. A simple procedure for the quantitative determination of the Oxacillin pure substance by the kinetic spectrophotometry and redox titration methods using potassium hydrogen peroxomonosulfate (KHSO5) has been developed. The results of the drug analysis obtained by newly developed and current methods are in good agreement with each other; δ (correctness) = (0.45 – 0.86) %.Conclusions. Using the methods of kinetic spectrophotometric and redox titration, two independent procedures for thequantitative determination of oxacillin in the substance and the drug product have been developed using potassium hydrogen peroxomonosulfate as an analytical reagent (KHSO5). A relative standard deviation RSD = (1.24 – 2.17) %.Мета. Пошук нових аналітичних реакцій та з’ясування оптимальних умов їх перебігу, які можуть бути покладені в основу кількісних аналітичних визначень пеніцилінів, є вельми актуальним завданням. Метою цієї роботи було розробити методики кількісного визначення оксациліну.Матеріали та методи. Обʼєктом дослідження був Оксацилін – порошок натрій оксациліну у флаконах для приготування розчину для ін’єкцій (0,5 г). Як окисник використовували потрійну калієву сіль 2КНSO5∙КНSO4∙K2SO4 кваліфікації “extra pure” (Oxone®). У дослідженні було задіяно методи кінетико-спектрофотометрії та окисно-відновного титрування.Результати та їх обговорення. Розроблено процедуру кількісного визначення оксациліну методами кінетико-спектрофотометрії та йодометричного титрування з використанням калій гідрогенпероксомоносульфату. Результати аналізу препарату, одержані за новоопрацьованими та чинними методиками, добре узгоджуються між собою; δ (правильність) = (0.45 – 0.86) %.Висновки. За допомогою методів кінетико-спектрофотометрії та йодометричного титрування розроблено дві незалежні методики кількісного визначення оксациліну в субстанції та лікарському препараті з використанням калій гідрогенпероксомоносульфату як аналітичного реагенту (KHSO5). Відносне стандартне відхилення RSD (1,24 – 2,17) %

Biological Impact of γ-Fe2O3 Magnetic Nanoparticles Obtained by Laser Target Evaporation: Focus on Magnetic Biosensor Applications

The biological activity of γ-Fe2O3 magnetic nanoparticles (MNPs), obtained by the laser target evaporation technique, was studied, with a focus on their possible use in biosensor applications. The biological effect of the MNPs was investigated in vitro on the primary cultures of human dermal fibroblasts. The effects of the MNPs contained in culture medium or MNPs already uptaken by cells were evaluated for the cases of the fibroblast’s proliferation and secretion of cytokines and collagen. For the tests related to the contribution of the constant magnetic field to the biological activity of MNPs, a magnetic system for the creation of the external magnetic field (having no commercial analogues) was designed, calibrated, and used. It was adapted to the size of standard 24-well cell culture plates. At low concentrations of MNPs, uptake by fibroblasts had stimulated their proliferation. Extracellular MNPs stimulated the release of pro-inflammatory cytokines (Interleukin-6 (IL-6) and Interleukin-8 (IL-8) or chemokine (C-X-C motif) ligand 8 (CXCL8)) in a concentration-dependent manner. However, the presence of MNPs did not increase the collagen secretion. The exposure to the uniform constant magnetic field (H ≈ 630 or 320 Oe), oriented in the plane of the well, did not cause considerable changes in fibroblasts proliferation and secretion, regardless of presence of MNPs. Statistically significant differences were detected only in the levels of IL-8/CXCL8 release.The study was supported by the program of the Ministry of Health of the Russian Federation (project 121032300335-1). This work was financially supported, in part, by the Ministry of Science and Higher Education of the RF (grant FEUZ-2020-0051) (G.Yu. Melnikov) and University of the Basque Country Research Groups Funding (grant IT1245-19) (G.V. Kurlyandskaya)

Features of study complex carbonate reservoir rocks` wetting using laboratory methods

Surface properties of rocks are the important parameter and have a great influence on the process of oil displacement by water. In real systems the wettability can range from highly hydrophilic to strongly hydrophobic depending on interaction between mineralized water and oil with rock surfaces. If the preferential wettability of any of two liquids is not observed in the rock, then the system has a neutral wetting. Some components of oil can wet the selected areas of porous surface around the reservoir. Under election wettability a spotted heterogeneous wettability of rock surface is understood. Wetting characteristic is a necessary criterion for evaluating the reservoir. There are qualitative and quantitative methods for estimating the wettability, which are divided into direct and indirect. Paper presents results of the study the surface properties of carbonate deposits, characterized by a complex structure of the hollow space and the complex composition of the mineral skeleton. Determination of wettability was carried out by two methods: according to industrial standard and Amott method. Characteristics of the rocks surface properties of different lithological types were established. To study the influence of extraction on the surface properties the wettability index was measured twice: in samples with natural oil saturation and in extracted samples. The regularities of changes in the surface properties along the well section of carbonate deposits were determined, a comparison of the wettability index and reservoir rock properties, as well as the residual water was performed by capillary pressure method. The descriptiveness analysis of various methods for determining the wettability was conducted and difference causes in the results of research were determind by methods of industrial standard and Amott. The presence of deposits, characterized by selective wetting was found

Gut microbiota of captive common bottlenose dolphins Tursiops truncatus gilli: influence of age, sex, birthplace, and contacts with dolphinarium visitors

Dolphins are aquatic mammals, whose role in microbial ecology is not fully understood. It is critical to study the microbiota of dolphins kept in captivity, as close contact with humans could unpredictably affect both human and animal health. In this study, we investigated the gut microbiota of 15 captive common bottlenose dolphins, and the relationship of microbial diversity and composition with animals’ age, sex, birthplace (dolphinarium or wildlife), and direct contacts with dolphinarium visitors using high-throughput V3-V4 16S rRNA amplicon sequencing. Based on acquired sequencing data we calculated and compared alpha and beta diversity indexes, as well as conducted differential abundance analysis of identified bacterial taxa to find multivariable associations with dolphins’ age period, sex, birthplace, and type of contact with humans with linear models. There was no association between gut microbiota composition and diversity and dolphins’ age period, sex, and birthplace. However, there were significant differences (q-value ≤ 0.00018) in the relative abundance of Edwardsiella genus in dolphins that were in contact only with dolphinarium staff in comparison to dolphins that apart from dolphinarium staff also had contact with dolphinarium visitors. These results show that dolphins born in wildlife and dolphinariums do not have significant differences in gut microbiota composition and the microbiota of captive dolphins can be affected by their contact with humans

Cardiolipin synthesis in brown and beige fat mitochondria is essential for systemic energy homeostasis

Activation of energy expenditure in thermogenic fat is a promising strategy to improve metabolic health, yet the dynamic processes that evoke this response are poorly understood. Here we show that synthesis of the mitochondrial phospholipid cardiolipin is indispensable for stimulating and sustaining thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response through overexpression of cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency in thermogenic adipocytes diminishes inducible mitochondrial uncoupling and elicits a nuclear transcriptional response through endoplasmic reticulum stress-mediated retrograde communication. Cardiolipin depletion in brown and beige fat abolishes adipose thermogenesis and glucose uptake, which renders animals insulin resistant. We further identify a rare human CRLS1 variant associated with insulin resistance and show that adipose CRLS1 levels positively correlate with insulin sensitivity. Thus, adipose cardiolipin has a powerful impact on organismal energy homeostasis through thermogenic fat bioenergetics

Protonation and Photocatalytic Activity of the Rb 2

The Rb2La2Ti3O10 layered oxide was synthesized by the solid-state method. Three phases with different protonation degrees and intercalated water contents were obtained from the initial compound by the treatment with distilled water and hydrochloric acid. The obtained samples were characterized by powder X-ray diffraction, SEM, X-ray microanalysis, BET, DRS, and TG. It was found that the complete ion exchange of Rb+ for H+ in the layered oxide Rb2La2Ti3O10 proceeds through the formation of two metastable intermediate phases with average protonation degrees of 0.5 and 0.75, which successively transform from one to another. Each of these phase transformations is accompanied not only by the contraction of the interlayer distance but also by the displacement of adjacent perovskite layers by 1/2 of the cell parameter which results in the change in the space group. The photocatalytic activity of obtained samples decreases with the increase in the protonation degree, which correlates with the decrease in the intercalated water content

Sphingosine kinase 2 deficiency increases proliferation and migration of renal mouse mesangial cells and fibroblasts

Both of the sphingosine kinase (SK) subtypes SK-1 and SK-2 catalyze the production of the bioactive lipid molecule sphingosine 1-phosphate (S1P). However, the subtype-specific cellular functions are largely unknown. In this study, we investigated the cellular function of SK-2 in primary mouse renal mesangial cells (mMC) and embryonic fibroblasts (MEF) from wild-type C57BL/6 or SK-2 knockout (SK2ko) mice. We found that SK2ko cells displayed a significantly higher proliferative and migratory activity when compared to wild-type cells, with concomitant increased cellular activities of the classical extracellular signal regulated kinase (ERK) and PI3K/Akt cascades, and of the small G protein RhoA. Furthermore, we detected an upregulation of SK-1 protein and S1P3 receptor mRNA expression in SK-2ko cells. The MEK inhibitor U0126 and the S1P1/3 receptor antagonist VPC23019 blocked the increased migration of SK-2ko cells. Additionally, S1P3ko mesangial cells showed a reduced proliferative behavior and reduced migration rate upon S1P stimulation, suggesting a crucial involvement of the S1P3 receptor. In summary, our data demonstrate that SK-2 exerts suppressive effects on cell growth and migration in renal mesangial cells and fibroblasts, and that therapeutic targeting of SKs for treating proliferative diseases requires subtype-selective inhibitors