Optical properties of Ge-oxygen defect center embedded in silica films

The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands centered at 4.3eV and 3.2eV associated with its de-excitation from singlet (S1) and triplet (T1) states, respectively, that are linked by an intersystem crossing process. The comparison with results obtained from a bulk Ge-doped silica sample evidences that the efficiency of the intersystem crossing rate depends on the properties of the matrix embedding the Ge-oxygen defect centers, being more effective in the film than in the bulk counterpart.Comment: 10 pages, 3 figures, in press on J. Non cryst. solids (2007

Genome-wide screen for genes involved in Caenorhabditis elegans developmentally timed sleep

In Caenorhabditis elegans, Notch signaling regulates developmentally timed sleep during the transition from L4 larval stage to adulthood (L4/A) . To identify core sleep pathways and to find genes acting downstream of Notch signaling, we undertook the first genome-wide, classical genetic screen focused on C. elegans developmentally timed sleep. To increase screen efficiency, we first looked for mutations that suppressed inappropriate anachronistic sleep in adult hsp::osm-11 animals overexpressing the Notch coligand OSM-11 after heat shock. We retained suppressor lines that also had defects in L4/A developmentally timed sleep, without heat shock overexpression of the Notch coligand. Sixteen suppressor lines with defects in developmentally timed sleep were identified. One line carried a new allele of goa-1; loss of GOA-1 Gαo decreased C. elegans sleep. Another line carried a new allele of gpb-2, encoding a Gβ5 protein; Gβ5 proteins have not been previously implicated in sleep. In other scenarios, Gβ5 GPB-2 acts with regulators of G protein signaling (RGS proteins) EAT-16 and EGL-10 to terminate either EGL-30 Gαq signaling or GOA-1 Gαo signaling, respectively. We found that loss of Gβ5 GPB-2 or RGS EAT-16 decreased L4/A sleep. By contrast, EGL-10 loss had no impact. Instead, loss of RGS-1 and RGS-2 increased sleep. Combined, our results suggest that, in the context of L4/A sleep, GPB-2 predominantly acts with EAT-16 RGS to inhibit EGL-30 Gαq signaling. These results confirm the importance of G protein signaling in sleep and demonstrate that these core sleep pathways function genetically downstream of the Notch signaling events promoting sleep

Luminescence and Raman Detection of Molecular Cl2 and ClClO Molecules in Amorphous SiO2 Matrix

The support from the Latvian Research Program project IMIS 2 (L.S., K.S.) and Latvian Science Council Grant 302/2012 (A.S.) is acknowledged. K.K. was partially supported by the Collaborative Research Project of Materials and Structures Laboratory, Tokyo Institute of Technology. H.H. was supported by the MEXT Element Strategy Initiative to form research cores.Chlorine is a common undesirable impurity in synthetic SiO2 glass for ultraviolet optics and optical fibers. It is usually incorporated into glass as bound Si-Cl groups or interstitial Cl2 molecules. We report a high-sensitivity detection of Cl2 in amorphous SiO2 (a-SiO2) by photoluminescence (PL) and also by Raman spectroscopy. The Cl2 PL emission band at 1.22 eV (1016 nm) appears at T < 160 K and shows a characteristic vibronic progression with separations ≈(520-540) cm-1 and an average lifetime of ≈5 ms at 13 K. Its excitation spectrum coincides with the shape of the 3.78 eV (328 nm) optical absorption band of Cl2 in a-SiO2, corresponding to the X → A 1Πu transition to repulsive excited state. Direct X → a singlet-to-triplet excitation was also observed at 2.33 eV (532 nm). Cl2 PL may serve as a sensitive and selective tool for monitoring Cl impurities and their reactions in a-SiO2. A Raman band of Cl2 is found at 546 cm-1. Cl2 photodissociation at energies up to 4.66 eV (266 nm) was not detected, pointing to a strong cage effect in a-SiO2 matrix. However, 7.9 eV (157 nm) photolysis of interstitial O2 molecules gives rise to a Raman band at 954 cm-1, indicating a formation of dichlorine monoxide isomer, ClClO molecule by reaction of O atoms with interstitial Cl2. (Graph Presented).IMIS2; Latvian Science Council Grant 302/2012; Tokyo Institute of Technology; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

SUBJECTIVE PERCEPTION OF AN INDIVIDUAL WITHIN SOCIALISATION PROCESS

This a pilot study where the study method “Autoidentification and Identification Method According to Oral Portrayals of Character”. Contemporary psychological studies show that a person’s behaviour in social context is not only simple consequences of the objective conditions having effect on him or her, it significantly depends on subjective perception and interpretation of the aggregate of external events, i.e., determination of situation carried out by an individual. Autoidentification method according to oral portrayals of character (Эйдемиллер, 1973) was used for diagnosing the personality and image of “I” accentuation types. The pilot study involved two groups of adolescents; one group included adolescents with deviant behaviour (n=60, 39 boys, 21 girl) but the second group included adolescents without actual behaviour disorders (n= 60, 35 boys, 25 girls). The study allowed determination of differences between the results presented by both groups with constituting grounds for performing further empiric study with a larger selection of study in the future

Chronic alcohol abuse is implicated in the oxidative stress and the changes in the neurotrophic factor receptor expression in the human CNS

Alcohol abuse and alcoholism induce brain damage, and, in some cases, neurodegeneration. The pathogenesis of the alcohol-induced injury of the CNS is a complex process in which oxidative stress plays an essential role. Alcohol increases the formation of reactive oxygen species and affects the antioxidant defense system of the brain. It is well known that oxidative stress induces apoptosis in neurons, as well as in other cell types. Neurotropins and their receptors have a crucial role in neural regulation. The aim of this study is an overall analysis of the CNS neuronal and glial cell death and the oxidative status by the use of immunohistochemical methods. Three different CNS regions – cortical, subventricular and basal ganglia were analyzed in the autopsy samples obtained from 10 chronic alcohol abused patients. The immunohistochemical detection of oxidative damage was performed using anti-Cu/Zn SOD monoclonal antibody, neural activity – anti-NGFR (p75&lt;sup&gt;NTR&lt;/sup&gt;) antibody, apoptosis – the TUNEL reaction. Both, quantitative and semiquantitative estimations were used for the evaluation of results. The subventricular zone was characterized by a negative (75%) and a moderate (25%) astroglial SOD1 expression, the basal ganglia region – by strong (43%), moderate (43%), and low (14%) neuronal and moderate (71%) and low (29%) astroglial SOD1 expression, whereas, the cortex – by strong (33%) and moderate (66%) neuronal and moderate (67%), low (17%) and negative (17%) astroglial expression. The SOD1 expression was not detected in oligodendroglia and ependymocytes. Brain regions showed variability in the apoptotic cell death rates. Neuronal TUNEL-positive staining in basal ganglia was higher than in the cerebral cortex. TUNEL-positive astrocytes were detected in the white matter, more frequently in the basal ganglia region when compared to the cortex. The apoptosis marker was nearly absent in ependymal and oligodendroglial cells. The rate of TUNEL-positive cortex endothelial cells was detected at 7.9% level in the case of chronic alcohol abuse. Neuronal processes showed heterogeneous NGFR expression: in the cortex, basal ganglia and the subventricular zone (negative/low), whereas the subcortex and the white matter – moderate and moderate/strong, accordingly. Alcohol-induced CNS vulnerability is related to the increase in oxidative stress; furthermore, it suggests an increased risk of neurodegeneration for neuronal and glial cells

Effects of retained fetal membranes treatments and dry period length on the subsequent lactation in cows - milk yield and somatic cell count

Received: October 13th, 2020 ; Accepted: December 14th, 2020 ; Published: December 18th, 2020 ; Correspondence: [email protected] treatment strategies in cows with retained fetal membranes (RFM) may affect subsequent lactation in various ways. Also, excessively short or long dry periods (DP) can decrease milk yield (MY), increase the risk of poor udder health, and increase the risk of RFM. This study aimed to evaluate how different treatment strategies of RFM affect subsequent lactation in cows, i.e., MY and udder health determined on the somatic cell count (SCC) bases in milk, expressed as somatic cell score (SCS). A secondary but equally important objective was to analyse the dry period length (DPL) effect on the subsequent lactation in cows. The cows from two herds were divided into three groups: group 1–healthy control; group 2–cows with RFM, removed manually and treated with intrauterine (IU) antibiotics (AB); group 3–cows with RFM, not removed, but treated IU with AB. The DP of cows was divided post factum into shortened (up to 46 days), traditional (47 to 70 days), or prolonged (over 70 days). Statistical analyses were performed using linear multiple regression and multivariate analyses. Differences were statistically significant when P <0.05. The effect of different RFM treatment strategies on MY and SCS was evaluated. There were no statistically significant effects of RFM treatments on the MY in the subsequent lactation. However, there was a tendency (P = 0.07) for SCS in standard lactation to be higher in cows in group 2. The highest economic losses, calculated from the decrease in MY, were detected in the same group. Significantly lower MY was observed in cows with a shortened DPL during the first 30 days PP (P <0.05). The DPL did not affect the SCS

Human herpesvirus-6 and-7 in the brain microenvironment of persons with neurological pathology and healthy people

Funding Information: This research was supported by the Latvian Council of Science Grant Nr.478/2012 and fundamental and applied research project of the Latvian Council of Science LZP-2020/2-0069. The authors would like to thank Svetlana Chapenko for nPCR data curation, and Silvija Roga, certified pathologist, and Ojars Teteris certified pathologist, for collecting of study material. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.During persistent human beta-herpesvirus (HHV) infection, clinical manifestations may not appear. However, the lifelong influence of HHV is often associated with pathological changes in the central nervous system. Herein, we evaluated possible associations between immunoex-pression of HHV-6,-7, and cellular immune response across different brain regions. The study aimed to explore HHV-6,-7 infection within the cortical lobes in cases of unspecified encephalo-pathy (UEP) and nonpathological conditions. We confirmed the presence of viral DNA by nPCR and viral antigens by immunohistochemistry. Overall, we have shown a significant increase (p < 0.001) of HHV antigen expression, especially HHV-7 in the temporal gray matter. Although HHV-infected neurons were found notably in the case of HHV-7, our observations suggest that higher (p < 0.001) cell tropism is associated with glial and endothelial cells in both UEP group and controls. HHV-6, predominantly detected in oligodendrocytes (p < 0.001), and HHV-7, predominantly detected in both astrocytes and oligodendrocytes (p < 0.001), exhibit varying effects on neural homeostasis. This indicates a high number (p < 0.001) of activated microglia observed in the temporal lobe in the UEP group. The question remains of whether human HHV contributes to neurological diseases or are markers for some aspect of the disease process.Peer reviewe

Stability of E' centers induced by 4.7eV laser radiation in SiO2

The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed laser irradiation in dry fused silica was investigated by in situ optical absorption spectroscopy. The stability of the defects, conditioned by reaction with mobile hydrogen of radiolytic origin, is discussed and compared to results of similar experiments performed on wet fused silica. A portion of E' and hydrogen are most likely generated by laser-induced breaking of Si-H precursors, while an additional fraction of the paramagnetic centers arise from another formation mechanism. Both typologies of E' participate to the reaction with H_2 leading to the post-irradiation decay of the defects. This annealing process is slowed down on decreasing temperature and is frozen at T=200K, consistently with the diffusion properties of H_2 in silica.Comment: 12 pages, 3 figures, in press on J. Non cryst. solids (2007