Клінічні ознаки у собак, що позитивно реагують на антиген Yersinia enterocolitica 0:9

Canine yersiniosis is currently a scantily researched disease. Two agents predominately cause yersiniosis: Y. enterocolitica (gut yersiniosis), Y. preudotuberculosis (yersiniosis). There are three clinical forms of the disease: intestinal, generalized and secondary-focal. Current available research states the prevalence of Y. enterocolitica against other biovariants in canine infections. The majority of infected dogs demonstrate both asymptomatic clinical course and unspecific symptoms or serve as a carrier. Meanwhile yersiniosis pose a threat to human health causing a severe complex of symptoms. In some cases the disease can be lethal, thus the disease has both epizootological and epidemiological value. The goal of this paper was to generalize clinical signs in dogs that demonstrated positive reaction to Y. enterocolitica antigen 0:9, which is a dominant causative agent of yersiniosis in the northeastern region of Ukraine. The study was conducted based on clinical data, biochemical and hematological laboratory studies. Contamination of canine subjects with Y. enterocolitica 0:9 was conducted using agglutination reaction using respective antigen. The research showed, that the dominant symptoms in canines, affected by Yersinia serovariant 0:9 were gastrointestinal lesions in 100 % of the cases. The clinical signs included melena or bloody stool, general depression, anorexia, cachexia, more rarely – vomiting, tachypnea and breathing irregularities. The results of biochemical blood assays and CBC were heterogeneous and cannot be used as a specific marker of Yersinia infection. The main method of confirmation for Yersinia infection would be a serological agglutination reaction, which can identify positive diagnostic titers in animal blood samples. Further research is planned to study mono- and concurrent course of Yersiniosis with different infectious diseases.Ієрсиніоз собак досі маловивчене захворювання. Найчастіше його викликають два збудники – Y. enterocolitica (кишковий ієрсиніоз) і Y. pseudotuberculosis (ієрсиніоз). Виділяють три клінічні форми хвороби: кишкову, генералізовану, вторинно-вогнещеву. Відомі дослідження вказують на превалювання Y. enterocolitica над іншими біоварами в інфекційному процесі у собак. У більшості інфікованих собак захворювання перебігає безсимптомно з неспецифічною клінічною картиною або у вигляді бактеріоносійства. Водночас ієрсиніози становляють загрозу здоров’ю людини, проявляючись складним симптомокомплексом, а в окремих випадках закінчуються летально. Тому ієрсиніоз має як епізоотологічне, так і епідеміологічне значення. Мета роботи – узагальнити клінічні ознаки у собак, які в діагностичних титрах реагували на ієрсиніозний антиген Y. enterocolitica 0:9, домінуючий збудник кишкового ієрсиніозу собак в північно-східному регіоні України. У роботі використовували клінічні, гематологічні та біохімічні дослідження. Позитивні реакції на контамінацію організму собак Y. enterocolitica 0:9 визначали в реакції аглютинації з відповідним антигеном. Дослідження показали, що домінуючими симптомами при ураженні собак сероваром 0:9 у 100 % випадків було ураження шлунково-кишкового тракту з діареєю, з домішками крові у фекаліях, на тлі пригнічення, анорексії, кахексії. Рідше хвороба супроводжувалася блюванням і порушенням ритму дихання. Результати гематологічних та біохімічних досліджень у собак з позитивною реакцією на іерсініозной антиген 0:9 характеризувалися різноманітністю і не можуть служити діагностичним маркером ієрсиниозної інфекції. Основною підозрою на захворювання кишковим ієрсинізом може слугувати серологічна реакція аглютинації з виявленням позитивно реагуючих тварин в діагностичних титрах. Подальші дослідження планується спрямувати на вивчення моно- і асоційованого перебігу ієрсиніозу з іншими захворюваннями собак інфекційної природи

Controlling Molecular Scattering by Laser-Induced Field-Free Alignment

We consider deflection of polarizable molecules by inhomogeneous optical fields, and analyze the role of molecular orientation and rotation in the scattering process. It is shown that molecular rotation induces spectacular rainbow-like features in the distribution of the scattering angle. Moreover, by preshaping molecular angular distribution with the help of short and strong femtosecond laser pulses, one may efficiently control the scattering process, manipulate the average deflection angle and its distribution, and reduce substantially the angular dispersion of the deflected molecules. We provide quantum and classical treatment of the deflection process. The effects of strong deflecting field on the scattering of rotating molecules are considered by the means of the adiabatic invariants formalism. This new control scheme opens new ways for many applications involving molecular focusing, guiding and trapping by optical and static fields

Crucial role of sidewalls in velocity distributions in quasi-2D granular gases

Our experiments and three-dimensional molecular dynamics simulations of particles confined to a vertical monolayer by closely spaced frictional walls (sidewalls) yield velocity distributions with non-Gaussian tails and a peak near zero velocity. Simulations with frictionless sidewalls are not peaked. Thus interactions between particles and their container are an important determinant of the shape of the distribution and should be considered when evaluating experiments on a tightly constrained monolayer of particles.Comment: 4 pages, 4 figures, Added reference, model explanation charified, other minor change

Effective pair potentials for spherical nanoparticles

An effective description for spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, the effective potential generally has non-analytic points, but for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered, and shown to be related to those for solid nanoparticles. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London-Van der Waals, Morse, Buckingham, and Lennard-Jones potential. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure.Comment: 27 pages, 12 figures. Unified description of overlapping and nonoverlapping particles added, as well as a comparison with an idealized atomic descriptio

Gene duplication of the zebrafish kit ligand and partitioning of melanocyte development functions to kit ligand a

The retention of particular genes after the whole genome duplication in zebrafish has given insights into how genes may evolve through partitioning of ancestral functions. We examine the partitioning of expression patterns and functions of two zebrafish kit ligands, kit ligand a (kitla) and kit ligand b (kitlb), and discuss their possible coevolution with the duplicated zebrafish kit receptors (kita and kitb). In situ hybridizations show that kitla mRNA is expressed in the trunk adjacent to the notochord in the middle of each somite during stages of melanocyte migration and later expressed in the skin, when the receptor is required for melanocyte survival. kitla is also expressed in other regions complementary to kita receptor expression, including the pineal gland, tail bud, and ear. In contrast, kitlb mRNA is expressed in brain ventricles, ear, and cardinal vein plexus, in regions generally not complementary to either zebrafish kit receptor ortholog. However, like kitla, kitlb is expressed in the skin during stages consistent with melanocyte survival. Thus, it appears that kita and kitla have maintained congruent expression patterns, while kitb and kitlb have evolved divergent expression patterns. We demonstrate the interaction of kita and kitla by morpholino knockdown analysis. kitla morphants, but not kitlb morphants, phenocopy the null allele of kita, with defects for both melanocyte migration and survival. Furthermore, kitla morpholino, but not kitlb morpholino, interacts genetically with a sensitized allele of kita, confirming that kitla is the functional ligand to kita. Last, we examine kitla overexpression in embryos, which results in hyperpigmentation caused by an increase in the number and size of melanocytes. This hyperpigmentation is dependent on kita function. We conclude that following genome duplication, kita and kitla have maintained their receptor-ligand relationship, coevolved complementary expression patterns, and that functional analysis reveals that most or all of the kita receptor's function in the embryo are promoted by its interaction with kitla. © 2007 Hultman et al

Relativistic dynamical polarizability of hydrogen-like atoms

Using the operator representation of the Dirac Coulomb Green function the analytical method in perturbation theory is employed in obtaining solutions of the Dirac equation for a hydrogen-like atom in a time-dependent electric field. The relativistic dynamical polarizability of hydrogen-like atoms is calculated and analysed.Comment: 15 pages, 3 figures (not included, but hard copies are available upon request

Many-electron tunneling in atoms

A theoretical derivation is given for the formula describing N-electron ionization of atom by a dc field and laser radiation in tunneling regime. Numerical examples are presented for noble gases atoms.Comment: 11 pages, 1 EPS figure, submitted to JETP (Jan 99

Two-Photon 2s<->1s Transitions during Recombination of Hydrogen in the Universe

Based on the standard cosmological model, we calculate the correction to the rate of two-photon 2s1s transitions in the hydrogen atom under primordial hydrogen plasma recombination conditions that arises when the induced transitions under equilibrium background radiation with a blackbody spectrum and plasma recombination radiation are taken into account.Comment: 20 pages, 9 figure

Zebrafish modeling reveals that SPINT1 regulates the aggressiveness of skin cutaneous melanoma and its crosstalk with tumor immune microenvironment

Background Skin cutaneous melanoma (SKCM) is the most lethal form of skin cancer and while incidence rates are declining for most cancers, they have been steadily rising for SKCM. Serine protease inhibitor, kunitz-type, 1 (SPINT1) is a type II transmembrane serine protease inhibitor that has been shown to be involved in the development of several types of cancer, such as squamous cell carcinoma and colorectal cancer. Methods We used the unique advantages of the zebrafish to model the impact of Spint1a deficiency in early transformation, progression and metastatic invasion of SKCM together with in silico analysis of the occurrence and relevance of SPINT1 genetic alterations of the SKCM TCGA cohort. Results We report here a high prevalence of SPINT1 genetic alterations in SKCM patients and their association with altered tumor immune microenvironment and poor patient survival. The zebrafish model reveals that Spint1a deficiency facilitates oncogenic transformation, regulates the tumor immune microenvironment crosstalk, accelerates the onset of SKCM and promotes metastatic invasion. Notably, Spint1a deficiency is required at both cell autonomous and non-autonomous levels to enhance invasiveness of SKCM. Conclusions These results reveal a novel therapeutic target for SKCM

Atomic excitation during recollision-free ultrafast multi-electron tunnel ionization

Modern intense ultrafast pulsed lasers generate an electric field of sufficient strength to permit tunnel ionization of the valence electrons in atoms. This process is usually treated as a rapid succession of isolated events, in which the states of the remaining electrons are neglected. Such electronic interactions are predicted to be weak, the exception being recollision excitation and ionization caused by linearly-polarized radiation. In contrast, it has recently been suggested that intense field ionization may be accompanied by a two-stage `shake-up' reaction. Here we report a unique combination of experimental techniques that enables us to accurately measure the tunnel ionization probability for argon exposed to 50 femtosecond laser pulses. Most significantly for the current study, this measurement is independent of the optical focal geometry, equivalent to a homogenous electric field. Furthermore, circularly-polarized radiation negates recollision. The present measurements indicate that tunnel ionization results in simultaneous excitation of one or more remaining electrons through shake-up. From an atomic physics standpoint, it may be possible to induce ionization from specific states, and will influence the development of coherent attosecond XUV radiation sources. Such pulses have vital scientific and economic potential in areas such as high-resolution imaging of in-vivo cells and nanoscale XUV lithography.Comment: 17 pages, 4 figures, original format as accepted by Nature Physic