A new model for evolution in a spatial continuum

We investigate a new model for populations evolving in a spatial continuum. This model can be thought of as a spatial version of the Lambda-Fleming-Viot process. It explicitly incorporates both small scale reproduction events and large scale extinction-recolonisation events. The lineages ancestral to a sample from a population evolving according to this model can be described in terms of a spatial version of the Lambda-coalescent. Using a technique of Evans(1997), we prove existence and uniqueness in law for the model. We then investigate the asymptotic behaviour of the genealogy of a finite number of individuals sampled uniformly at random (or more generally `far enough apart') from a two-dimensional torus of side L as L tends to infinity. Under appropriate conditions (and on a suitable timescale), we can obtain as limiting genealogical processes a Kingman coalescent, a more general Lambda-coalescent or a system of coalescing Brownian motions (with a non-local coalescence mechanism).Comment: 63 pages, version accepted to Electron. J. Proba

CW and pulsed electrically detected magnetic resonance spectroscopy at 263 GHz/12 T on operating amorphous silicon solar cells

Here we describe a new high frequency/high field continuous wave and pulsed electrically detected magnetic resonance (CW EDMR and pEDMR) setup, operating at 263 GHz and resonance fields between 0 and 12 T. Spin dependent transport in illuminated hydrogenated amorphous silicon p-i-n solar cells at 5 K and 90 K was studied by in operando 263 GHz CW and pEDMR alongside with complementary X-band CW EDMR. Benefiting from the superior resolution at 263 GHz, we were able to better resolve EDMR signals originating from spin dependent hopping and recombination processes. 5 K EDMR spectra were found to be dominated by conduction and valence band tale states involved in spin dependent hopping, with additional contributions from triplet exciton states. 90 K EDMR spectra could be assigned to spin pair recombination involving conduction band tail states and dangling bonds as dominating spin dependent transport process, with additional contributions from valence band tail and triplet exciton states.Comment: 8 pages, 4 figure

Non-alcoholic fatty liver disease as a risk factor for anemia of chronic inflammation (experimental research)

The aim of the study. In recent years, non-alcoholic fatty liver disease (NAFLD) has been considered a hepatic manifestation of the metabolic syndrome. The main consequence of NAFLD is chronic hepatic inflammation, which leads to dyslipidemia, inflammation, increased oxidative stress, and endothelial dysfunction. Immune activation in response to interaction with agents of a metabolic nature induces the release of pro-inflammatory cytokines in the liver, which subsequently cause iron сhomeostasis disorder. This leads to a frequent association of NAFLD with anemia of various etiology. In this regard, we considered it important to assess the severity of the systemic inflammatory response in NAFLD in the experiment in order to -diagnose anemia of chronic inflammation.Materials and methods. The study was carried out on 26 male Wistar rats, which were divided into control and experimental groups. In animals of the experimental group, NAFLD was modeled according to the generally accepted method. In order to assess metabolic disorders, we determined the main biochemical parameters, a complete blood count with the calculation of erythrocyte indices, the concentration of the main pro-inflammatory cytokines – interleukin (IL) 1, IL-6. Results. In laboratory rats with NAFLD, a statistically significant increase of intrahepatic enzymes in blood serum was found. The state of the erythrocyte lineage of hematopoiesis in the experimental group progressively worsened and caused the development of anemic syndrome. Synchronously, a statistically significant increase in serum levels of IL-1, IL-6 was recorded, which confirms the correlation of NAFLD with anemia of chronic inflammation.Conclusions. A high concentration of IL-1, IL-6 cytokines in NAFLD inhibits iron absorption in the duodenum, leads to the activation of macrophages, blocking the release of iron processed from aging erythrocytes into plasma. Further study of the mechanisms of anemia in NAFLD provides important therapeutic targets in the treatment of both NAFLD and its comorbidities

Emergence and fate of stem cell-like Tcf7⁺ CD8⁺ T cells during a primary immune response to viral infection.

In response to infection, naïve CD8 <sup>+</sup> T (T <sub>N</sub> ) cells yield a large pool of short-lived terminal effector (T <sub>TE</sub> ) cells that eliminate infected host cells. In parallel, a minor population of stem cell-like central memory (T <sub>CM</sub> ) cells forms, which has the capacity to maintain immunity after pathogen clearance. It has remained uncertain whether stem-like T <sub>CM</sub> cells arise by dedifferentiation from a subset of cytolytic T <sub>TE</sub> cells or whether priming generates stem-like cells capable of seeding the T <sub>CM</sub> compartment and, if so, when cytolytic T <sub>TE</sub> cells branch off. Here, we show that CD8 <sup>+</sup> T cells with stem-like properties, which are identified by the expression of TCF1 (encoded by Tcf7), are present across the primary response to infection. Priming programs T <sub>N</sub> cells to undergo multiple cell divisions, over the course of which TCF1 expression is maintained. These TCF1 <sup>+</sup> cells further expand relatively independently of systemic inflammation, antigen dose, or affinity, and they quantitatively yield TCF1 <sup>+</sup> T <sub>CM</sub> cells after pathogen clearance. Inflammatory signals suppress TCF1 expression in early divided TCF1 <sup>+</sup> cells. TCF1 down-regulation is associated with the irreversible loss of self-renewal capacity and the silencing of stem/memory genes, which precedes the stable acquisition of a T <sub>TE</sub> state. TCF1 expression restrains cell cycling, explaining in part the limited expansion of TCF1 <sup>+</sup> relative to TCF1 <sup>-</sup> cells during the primary response. Thus, our data are consistent with terminal differentiation of effector cells being a step-wise process that is initiated by inflammation in primed stem-like cells, which would otherwise become central memory cells by default

Easy-plane to easy-axis anisotropy switching in a Co(ii) single-ion magnet triggered by the diamagnetic lattice

Single ion magnets SIMs with large magnetic anisotropy are promising candidates for realization of single molecule based magnetic memory and qubits. Creation of materials with magnetically uncoupled spatially separated SIMs requires dilution in a diamagnetic matrix. Herein, we report that progressive dilution of paramagnetic Co II by diamagnetic Zn II in the SIM [CoxZn 1 amp; 8722;x piv 2 2 NH2 Py 2], x 1 0 beyond a threshold of 50 reveals an abrupt structural change, where the distorted tetrahedral Zn coordination structure is superimposed on the remaining Co ions, which were initially in a distorted octahedral environment. Dilution induced structure modification switches the magnetic anisotropy from easy plane D 36.7 cm amp; 8722;1 to easy axis type D amp; 8722;23.9 cm amp; 8722;1 , accompanied by a fivefold increase of the magnetic relaxation time at 2 K. Changes of the static and dynamic magnetic properties are monitored by electron paramagnetic resonance spectroscopy and AC susceptibility measurements. Complementary quantum chemical ab initio calculations quantify the influence of structural changes on the electronic structure and the magnetic anisotropy. Thus, magnetic dilution hits two goals at once, the creation of isolated magnetic centres and an improvement of their SIM propertie

EFFECTS OF AMLODIPIN AND METOPROLOL ON AUTONOMIC SYSTEM IN EMOTIONAL AND COLD TESTS IN HYPERTENSIVE PATIENTS WITH DIFFERENT PSYCHOLOGICAL PROFILE

Aim. To asses effects of amlodipin and metoprolol on autonomic system in emotional and cold tests in hypertensive patients with different psychological profile (PP) Material and methods. 61 patients with arterial hypertension of II grade were observed. Therapy with amlodipin or metoprolol was prescribed and allowed to reach target blood pressure (BP) level in all the patients. Patients were divided into 2 groups: 1-st one – patients with normal PP, 2-nd group – patients with subclinical depression. Patients were examined before and 30 days after therapy. Examination included ambulatory BP monitoring, assessment of autonomic status by variational intervalometry and spectral analysis of heart rate variability (HRV) in cold and emotional tests. Depression and anxiety levels were determined with Bek’s and HADS scales.  Results. Treatment with amlodipin  and metoprolol can result in improvement, worsening or unchanging of PP.  In hypertensive patients with subclinical depression improving their PP resulted in autonomic reaction change: sympathetic activity increases and reaction on stress becomes more adequate. If subclinical depression occurred in hypertensive patients because of amlodipin and metoprolol therapy, sympathetic system stress-reaction decreased and parasympathetic influence increased. Conclusion. The study results show necessity of psychometric examination of hypertensive patients in order to reveal subclinical depression and anxiety

Luminescent properties of Bi-doped polycrystalline KAlCl4

We observed an intensive near-infrared luminescence in Bi-doped KAlCl4 polycrystalline material. Luminescence dependence on the excitation wavelength and temperature of the sample was studied. Our experimental results allow asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion which isomorphically substitutes potassium in the crystal. It was also demonstrated that Bi+ luminescence features strongly depend on the local ion surroundings