403 research outputs found
Spin-other-orbit operator in the tensorial form of second quantization
The tensorial form of the spin-other-orbit interaction operator in the
formalism of second quantization is presented. Such an expression is needed to
calculate both diagonal and off-diagonal matrix elements according to an
approach, based on a combination of second quantization in the coupled
tensorial form, angular momentum theory in three spaces (orbital, spin and
quasispin), and a generalized graphical technique. One of the basic features of
this approach is the use of tables of standard quantities, without which the
process of obtaining matrix elements of spin-other-orbit interaction operator
between any electron configurations is much more complicated. Some special
cases are shown for which the tensorial structure of the spin-other-orbit
interaction operator reduces to an unusually simple form
Optimization of Nanostructuring Burnishing Technological Parameters by Taguchi Method
On the basis of application of Taguchi optimization method, an approach for researching influence of nanostructuring burnishing technological parameters, considering the surface layer microhardness criterion, is developed. Optimal values of burnishing force, feed and number of tool passes for hardened steel AISI 420 hardening treatment are defined
AKMEOLOGICAL ROLE OF HEAD OF THE DEPARTMENT FROM THE POSITION OF STRATEGIC DEVELOPMENT PROGRAM OF UNIVERSITY
The article considers the modern requirements to the education system, explores of strategic development program of Kalashnikov Izhevsk State Technical University. The authors identify the department as a basic unit of the University and describe the role of the head of the Department in the system of University management.В статье рассматриваются современные требования, предъявляемые к системе образования, исследуется программа стратегического развития Ижевского государственного технического университета имени М. Т. Калашникова. Авторы выделяют кафедру как базовое подразделение вуза и описывают роль заведующего кафедрой в системе управления вузом
Optimization of Nanostructuring Burnishing Technological Parameters by Taguchi Method
On the basis of application of Taguchi optimization method, an approach for researching influence of nanostructuring burnishing technological parameters, considering the surface layer microhardness criterion, is developed. Optimal values of burnishing force, feed and number of tool passes for hardened steel AISI 420 hardening treatment are defined
Who Watches the Watchmen? An Appraisal of Benchmarks for Multiple Sequence Alignment
Multiple sequence alignment (MSA) is a fundamental and ubiquitous technique
in bioinformatics used to infer related residues among biological sequences.
Thus alignment accuracy is crucial to a vast range of analyses, often in ways
difficult to assess in those analyses. To compare the performance of different
aligners and help detect systematic errors in alignments, a number of
benchmarking strategies have been pursued. Here we present an overview of the
main strategies--based on simulation, consistency, protein structure, and
phylogeny--and discuss their different advantages and associated risks. We
outline a set of desirable characteristics for effective benchmarking, and
evaluate each strategy in light of them. We conclude that there is currently no
universally applicable means of benchmarking MSA, and that developers and users
of alignment tools should base their choice of benchmark depending on the
context of application--with a keen awareness of the assumptions underlying
each benchmarking strategy.Comment: Revie
Body composition as an indicator of metabolic changes in mice obtained by <i>in vitro</i> fertilization
To identify body systems subject to epigenetic transformation during in vitro fertilization (IVF), comparative morphological and functional studies were performed on sexually mature offspring of outbred CD1 mice, specific-pathogen-free (SPF), obtained by IVF (experiment) and natural conception (control). The studies included assessment of age-related changes in body weight and composition, energy intake and expenditure, and glucose homeostasis. To level the effects caused by the different number of newborns in the control and in the experiment, the size of the fed litters was halved in the control females. Males obtained using the IVF procedure were superior in body weight compared to control males in all age groups. As was shown by analysis of variance with experiment/control factors, gender, age (7, 10 and 20 weeks), the IVF procedure had a statistically significant and unidirectional effect on body composition. At the same time, IVF offspring outperformed control individuals in relative fat content, but were behind in terms of lean mass. The effect of the interaction of factors was not statistically significant. IVF offspring of both sexes had higher fat to lean mass ratios (FLR). Since adipose tissue contributes significantly less to total energy intake compared to muscle, the main component of lean mass, it is not surprising that at the same level of IVF locomotor activity offspring consumed less food than controls. When converted to one gram of body weight, this difference reached 19 %. One of the consequences of reduced utilization of IVF energy substrates by offspring is a decrease in their tolerance to glucose loading. The integral criterion for the effectiveness of restoring the initial glucose level is the area under the curve (AUC), the value of which was 2.5 (males) and 3.2 (females) times higher in IVF offspring compared to the corresponding control. Thus, the totality of our original and literature data shows an increase in the risk of metabolic disorders in IVF offspring, which is confirmed by epidemiological studies of a relatively young cohort of people born using assisted reproductive technologies
Reproductive effects of the tumor necrosis factor (TNF) deficiency in mice
TNF is a multifunctional cytokine that, at physiological concentrations, maintains the balance between apoptosis and survival of male germ cells and, at higher concentrations, has adverse effects on various stages of the reproductive process. Although ant-cytokine therapies have been used in millions of patients, the consequences of cytokine deficiency for reproductive functions are poorly understood and need attention. In this work, we have studied behavioral interactions between males and females, spermatogenesis, male fertility, and embryonic developmental characteristics of the progeny in TNFα knockout mice (TNF-/-). We have demonstrated that TNF is involved in the regulation of sexual behavior, spermatogenesis, pre- and postimplantation development. Complete TNF deficiency led to decreased reproductive efficiency: a lower number of viable embryos were observed in TNF-/- mice than in wild-type mice. The decrease in fertility was caused by preimplantation embryo loss in TNF-/- mice. Preimplantation loss in females might be caused by asospermia in TNF-/- males. Additionally, the sensitivity of reproductive functions to female stimuli was different between TNF-/- mice and wild-type mice, while interactions with females increased the concentrations of spermatozoids in both TNF-/- and wild-type mice. Still higher levels were observed in knockout animals, which led to increase in the number of immature spermatozoids in epididymides
Morphophysiological alterations caused by insertional mutagenesis of contactin 5 (Cntn5) gene in transgenic mice
Transgenesis has become a routine for modern biological studies. The most popular method for producing transgenic animals–pronuclear microinjection–frequently leads to host gene disruption due to a random transgene integration. In this paper, we report our analysis of morphophysiological parameters of the transgenic mouse line GM9, in which a transgene designed for milk-specific expression of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) gene was integrated into the intron of the Contactin 5 gene (Cntn5). We studied Cntn5 expression with RT-PCR and discovered that its expression in the brain, the primary organ of Cntn5 activity, was unperturbed. However, transgenic animals had less Cntn5 transcripts in other tissues such as the kidney and heart. In addition, we observed a decreased amount of splice variants of Cntn5 exons that flank the transgene integration site. These data suggest that the transgene integration event might affect proper Cntn5 splicing in some tissues. Publications exist that imply that some polymorphisms in the Cntn5 gene are associated with obesity and arterial hypertension in humans. We evaluated core parameters of lipid metabolism and heart activity in mice homozygous and heterozygous for Cntn5 mutation using wild- type animals as control. Our results uncovered that homozygous mutant mice have lower body weight than controls and that it is caused by slower accumulation of fat tissue. Cntn5 mutants also exhibit abnormalities in blood circulation: homozygous Cntn5 mutants are characterized by a higher blood pressure and heart beat rate, as well as faster blood flow in the tail vessels. Heterozygous animals showed intermediate results for all of these parameters
The development of initial material of spring common wheat for breeding for resistance to stem rust (Puccinia graminis Pers. f. sp. tritici), uncluding race Ug99, in Russia
Donors of resistance of common wheat to stem rust race Ug99 (breeding lines GT 96/90, 113/00i-4 and 119/4-06rw) are involved in cross breeding with the use of the step crossing and backcrossing method. While developing hybrids with the spring mode of life, donor of resistance 113/00i-4 (Sr2, Sr36, Sr39, Sr40, Sr44, Sr47) and accession 145/05i, which is resistant to leaf rust under the conditions of the RF Central Region but susceptible to Ug99, were used for backcrossing, 137 individual plants with the homozygotic state of alleles of 2–5 genes of resistance to stem rust were selected from the obtained hybrid families F4–F5 and backcross progeny BC1F3-BC2F2-BC3F2 by means of molecular markers. The progeny of these individual plants was tested in the North Caucasian and West Siberian regions of the RF for natural populations of stem and leaf rust and for powder mildew in the Central Region. The lines resistant to these diseases were estimated as to the other economically valuable features: plant height, number of days before heading, ear productivity, weight of 1,000 grains, protein and gluten content in grain, 71 spring wheat line with multiple resistance to two or three diseases and the development of best agronomic characters were selected for the Central region and 20 lines were selected for West Siberia for further testing of their competitiveness with the best varieties and lines in the breeding nurseries. As a result of the work, original source material was developed with several spring wheat resistance genes to Ug99
Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin
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