302 results on '"Eglitis, P."'
Search Results
2. Health effects of children’s summer holiday programs: a systematic review and meta-analysis
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Emily Eglitis, Ben Singh, Timothy Olds, Rosa Virgara, Amanda Machell, Mandy Richardson, Kylie Brannelly, Aniella Grant, Jessica Gray, Terri Wilkinson, Zoe Rix, Grant R. Tomkinson, and Carol Maher
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Holidays ,Obesity ,Physical activity ,Child health ,Health equity ,Nutritional diseases. Deficiency diseases ,RC620-627 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Unfavourable changes occur in children’s health behaviours and outcomes during the summer holidays. This systematic review aimed to determine the effectiveness of summer holiday programs in mitigating these changes. Methods Six databases (MEDLINE, JBI, PsychINFO, Embase, ERIC and Scopus) were systematically searched for experimental controlled studies that investigated programs of at least 5 days’ duration conducted exclusively during the summer holiday period on school-aged children (5–18 years). Primary outcomes were moderate-vigorous physical activity and energy intake. Secondary outcomes were sedentary behavior, diet quality, adiposity, and cardiorespiratory fitness. Risk of Bias was assessed using the PEDro tool. Effect sizes were calculated using random-effects meta-analysis with narrative synthesis of effects by student or program characteristics. Results Ten studies (two randomised controlled trials, and eight non-randomised controlled trials) involving 1,446 participants were included. Summer programs had a significant moderate effect on reducing sedentary behaviour (g= -0.59, 95%CI= -1.16, -0.03) and significant small effects on improving moderate-to-vigorous physical activity (g = 0.35, 95%CI = 0.02, 0.67) and adiposity (g= -0.25, 95% CI = -0.39, -0.10). No significant change was detected for cardiorespiratory fitness (g = 0.43, 95%CI= -0.32, 1.17), energy intake (g= -0.06, 95% CI -2.33, 2.22), or diet quality (g = 0.20, 95%CI= -0.43, 0.83). Summer program effectiveness did not appear to differ by child sociodemographic or program characteristics. Concerns regarding bias and high heterogeneity impacted results. Conclusions Summer programs show potential in promoting healthier movement behaviours in children and supporting healthy body weight during the summer months. Although evidence from the included studies has limitations, these programs produced small to moderate effect sizes and present promising health intervention opportunities for children. Future research with more rigorous study designs and comprehensive reporting is needed to confirm these findings and better understand the impact of summer programs on children’s health. Prospero registration CRD42023409795.
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- 2024
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3. Asteroids discovered in the Baldone Observatory between 2017 and 2022: The orbits of asteroid 428694 Saule and 330836 Orius
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Wlodarczyk Ireneusz, Černis Kazimieras, and Eglitis Ilgmar
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minor planets ,asteroids ,search ,astrometry ,orbits ,Astronomy ,QB1-991 - Abstract
We discovered 83 asteroids at the Baldone Astrophysical Observatory (MPC code 069) in 2017–2022. We studied one of the dynamically interesting Apollo (Near Earth object) observed at the Baldone Astronomical Observatory, namely 428694 Saule (2008 OS9) and the Centaur-type asteroid 330836 Orius (2009 HW77). We studied the evolution of the asteroid Saule’s rotation period, obliquity, and spin axis together with its non-gravitational parameter da∕dt{\rm{d}}a/{\rm{d}}t connected with the Yarkovsky effect. Additionally, we studied the orbit of the Amor-type asteroid 2017 UW42, which has the significant non-gravitational parameter A2A2.
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- 2024
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4. The Effect of High-Intensity Interval Training on Quality of Life and Incidence of Chemotherapy Side Effects in Women With Breast Cancer
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Aija Klavina, Rudolfs Ceseiko, Martins Campa, Greta Franceska Jermolenko, Kristaps Eglitis, Alicia Llorente, and Aija Linē
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Women with breast cancer (BC) experience multiple symptoms related to neoadjuvant chemotherapy (NAC) treatment that impair their functioning and quality of life (QoL). This study aimed to explore the effect of high-intensity aerobic interval training (HIIT) on quality of life and NAC side effects in women with BC. Methods: 56 patients (48.56 (7.84) years, range 35-64 years) diagnosed locally advanced (stage II-III) ER + BC receiving doxorubicin/cyclophosphamide-based NAC were randomly assigned to the HIIT group and a control group (CG) for 6 months. The HIIT group performed 2 to 3 HIIT sessions per week according to the study protocol (4 × 4 minutes at 85%-95% peak heart rate (HR)). The CG followed the standard of care instructions by the oncologists. To assess the QoL participants completed the EORTC QLQ-C30 with the additional BC module of QLQ BR-23. Weekly self-reports on NAC side effects were collected through online survey. Results: Study data were analyzed for 37 participants (nHIIT = 17, nCON = 20) who reported at least 14 (60%) weeks. HIIT was effective to reduce BC symptom scale outcomes (ES = 0.113, P = .048), and alleviate systemic therapy side effects (ES = 0.154, P = .020) and cancer related symptoms (ES = 0.124, P = .038). The most common side effect participants experienced at least 1 to 4 days/week was pain (average 50.9% and 56.8% for HIIT and CG, respectively), followed by sleep disturbances (average 50.9% and 49.9%, respectively). About 31% in both groups experienced sleep disturbances 5 to 7 days/week. The NAC induced physical, social and fatigue side effects had significantly lower incidence in HIIT group, while psychological side effects were significantly more common in training group. Conclusions: HIIT is an effective physical exercise program to maintain higher quality of life and help to reduce some of NAC induced side effects for women with BC.
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- 2024
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5. Multi-band Optical Variability of the TeV Blazar PG 1553+113 in 2019
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Dhiman, Vinit, Gupta, Alok C., Kurtanidze, Sofia O., Eglitis, I., Strigachev, A., Damljanovic, G., Wiita, Paul J., Gu, Minfeng, Gaur, Haritma, Vince, Oliver, Bachev, R., Bisen, D. P., Ibryamov, S., Ivanidze, R. Z., Jovanovic, Miljana D., Kurtanidze, Omar M., Nikolashvili, M. G., Semkov, E., Spassov, B., Stojanovic, M., Villarroel, Beatriz, Xu, Haiguang, and Zhang, Zhongli
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
We report the flux and spectral variability of PG 1553+113 on intra-night (IDV) to short-term timescales using BVRI data collected over 91 nights from 28 February to 8 November 2019 employing ten optical telescopes: three in Bulgaria, two each in India and Serbia, and one each in Greece, Georgia, and Latvia. We monitored the blazar quasi-simultaneously for 16 nights in the V and R bands and 8 nights in the V, R, I bands and examined the light curves (LCs) for intra-day flux and colour variations using two powerful tests: the power-enhanced F-test and the nested ANOVA test. The source was found to be significantly (> 99%) variable in 4 nights out of 27 in R-band, 1 out of 16 in V-band, and 1 out of 6 nights in I-band. No temporal variations in the colours were observed on IDV timescale. During the course of these observations the total variation in R-band was 0.89 mag observed. We also investigated the spectral energy distribution (SED) using B, V, R, and I band data. We found optical spectral indices in the range of 0.878+-0.029 to 1.106+-0.065 by fitting a power law to these SEDs of PG 1553+113. We found that the source follows a bluer-when-brighter trend on IDV timescales. We discuss possible physical causes of the observed spectral variability., Comment: 13 pages,8 figures, 7 tables, Accepted for publication in MNRAS
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- 2022
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6. Real-World Accuracy of Wearable Activity Trackers for Detecting Medical Conditions: Systematic Review and Meta-Analysis
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Ben Singh, Sebastien Chastin, Aaron Miatke, Rachel Curtis, Dorothea Dumuid, Jacinta Brinsley, Ty Ferguson, Kimberley Szeto, Catherine Simpson, Emily Eglitis, Iris Willems, and Carol Maher
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Information technology ,T58.5-58.64 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundWearable activity trackers, including fitness bands and smartwatches, offer the potential for disease detection by monitoring physiological parameters. However, their accuracy as specific disease diagnostic tools remains uncertain. ObjectiveThis systematic review and meta-analysis aims to evaluate whether wearable activity trackers can be used to detect disease and medical events. MethodsTen electronic databases were searched for studies published from inception to April 1, 2023. Studies were eligible if they used a wearable activity tracker to diagnose or detect a medical condition or event (eg, falls) in free-living conditions in adults. Meta-analyses were performed to assess the overall area under the curve (%), accuracy (%), sensitivity (%), specificity (%), and positive predictive value (%). Subgroup analyses were performed to assess device type (Fitbit, Oura ring, and mixed). The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Diagnostic Test Accuracy Studies. ResultsA total of 28 studies were included, involving a total of 1,226,801 participants (age range 28.6-78.3). In total, 16 (57%) studies used wearables for diagnosis of COVID-19, 5 (18%) studies for atrial fibrillation, 3 (11%) studies for arrhythmia or abnormal pulse, 3 (11%) studies for falls, and 1 (4%) study for viral symptoms. The devices used were Fitbit (n=6), Apple watch (n=6), Oura ring (n=3), a combination of devices (n=7), Empatica E4 (n=1), Dynaport MoveMonitor (n=2), Samsung Galaxy Watch (n=1), and other or not specified (n=2). For COVID-19 detection, meta-analyses showed a pooled area under the curve of 80.2% (95% CI 71.0%-89.3%), an accuracy of 87.5% (95% CI 81.6%-93.5%), a sensitivity of 79.5% (95% CI 67.7%-91.3%), and specificity of 76.8% (95% CI 69.4%-84.1%). For atrial fibrillation detection, pooled positive predictive value was 87.4% (95% CI 75.7%-99.1%), sensitivity was 94.2% (95% CI 88.7%-99.7%), and specificity was 95.3% (95% CI 91.8%-98.8%). For fall detection, pooled sensitivity was 81.9% (95% CI 75.1%-88.1%) and specificity was 62.5% (95% CI 14.4%-100%). ConclusionsWearable activity trackers show promise in disease detection, with notable accuracy in identifying atrial fibrillation and COVID-19. While these findings are encouraging, further research and improvements are required to enhance their diagnostic precision and applicability. Trial RegistrationProspero CRD42023407867; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=407867
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- 2024
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7. VEIN-RING: A Wearable Dorsal Finger Vein Biometric Scanner
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Teodors Eglitis, Emanuele Maiorana, and Patrizio Campisi
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Biometrics ,wearable biometrics ,vein biometrics ,open-source ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Vascular biometrics is gaining popularity in academic research, industrial systems, and public acceptance mainly because vein patterns are not exposed and thus offer more security against presentation attacks than traditional biometric traits. Likewise, wearable systems have begun to enter our lives more widely, primarily due to their convenience and the possibility of employing them in the framework of two-factor authentication mechanisms. This paper presents a new wearable vascular biometrics technology: a dorsal finger vein biometric scanner that can be worn as a ring and used for continuous user recognition. This device evolves a project developed for finger vein biometrics, and it is fully open-source. We provide all the necessary materials to replicate the device: the circuit schematics, the printed circuit board Gerber, the components list, the models for the 3D-printed case, and the software required for device control and database management. We have collected and made available a database of 30 subject/180 class dorsal finger vein images, with preliminary recognition results with HTER = 14.6%, using basic preprocessing and the Maximum Curvature/Miura Match pipeline, indicating potential for further research.
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- 2024
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8. Search for Alternative Raw Materials for Pellet Production – a Preliminary Study
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Priedniece Vivita, Sturmane Amanda, Eglitis Raivis, Juhnevica Inna, Krigers Guntars, and Kirsanovs Vladimirs
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alternative biofuels ,ash content ,ash melting ,biomass pellets ,calorific value ,chemical composition ,energy ,moisture content ,Renewable energy sources ,TJ807-830 - Abstract
A preliminary study for a selection of local alternative raw materials and their possible applicability in pellet production was done. 13 alternative biomass sources available in Riga, Latvia were tested: pine mix pellets (PMP); pellets of a mix of wood shavings, synthetic and textile waste (SSK); hogweed (Heracleum sosnowsky, HW); the full plant of Solidago canadensis L. (SC); the full plant of Solidago canadensis L. outgrown (SCO); mowed grass from the municipality (MGM); mowed grass from the garden (MGG); chamomile full plant without stems (Matricaria chamomilla, CF); hemp without roots (Cannabis sativa L., HWR); hemp stems (Cannabis sativa L., HS); hemp leaves with seeds (Cannabis sativa L., HLS); spent grain (SG); damaged spent grain (DSG). The determined quality parameters were the moisture content, the ash content, the calorific value and ash melting temperature. A comparison was made with the quality parameters defined in ENplus certification for B-class wood pellets in requirements for producers. Additional determination of chemical composition using XRD (X-ray diffraction) and SEM-EDX (scanning electron microscopy – energy dispersive X-ray spectroscopy) for the ash of two selected materials – SC and HLS – was performed to determine possible issues. The main issues highlighted by the results is the high ash content of alternative materials, up to 11.27 wt% while it is below 2.00 wt% for B-class wood pellets, and the low ash deformation temperature, below 1100 °C for 5 of the studied materials. Considering this, a calculation was made to determine the optimal proportion of alternative material to be used in a raw material mix for pellets to achieve a quality corresponding to B-class wood pellets. The aim of the study is to evaluate a set of locally available biomass materials, determining the values of their characteristic parameters, thus identifying alternative resources to wood for the production of pellets. This kind of promoting the diversification of energy resources, increasing energy independence and strengthening energy security.
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- 2024
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9. Changes in fitness and fatness in Australian schoolchildren during the summer holidays: fitness lost, fatness regained? A cohort study
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Tim Olds, Dorothea Dumuid, Emily Eglitis, Rebecca Golley, François Fraysse, Aaron Miatke, Grant R. Tomkinson, Amanda Watson, Mason Munzberg, and Carol Maher
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Shuttle run ,Child ,Summer ,Holiday ,Fitness ,Fatness ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Emerging evidence suggests that children’s fatness increases and fitness declines at a greater rate during the summer holiday period, compared with the school year. The aim of this study was to compare rates of change in fitness and fatness over the in-term and summer holiday periods among Australian schoolchildren. A secondary aim was to explore whether rates of change differed according to the child’s sex, socio-economic status (SES), pubertal status and weight status. Methods Children (n = 381) initially in Grade 4 (age 9) were recruited for this 2-year longitudinal study. Fatness (% body fat, BMI z-score, waist-to-height ratio) and fitness (20-m shuttle run and standing broad jump) were measured at the start and end of two consecutive years. Rates of change were calculated for the two in-school periods (Grades 4 and 5) and for the summer holiday period. Rates of change in fatness and fitness between in-school and holiday periods were compared, and differences in rates of change according to sex, socio-economic status, and weight status were explored. Results During the holidays, percentage body fat increased at a greater rate (annualised rate of change [RoC]: +3.9 vs. Grade 4 and + 4.7 vs. Grade 5), and aerobic fitness declined at a greater rate (RoC − 4.7 vs. Grade 4 and − 4.4 vs. Grade 5), than during the in-school periods. There were no differences in rates of change for BMI z-score, waist-to-height ratio or standing broad jump. Body fatness increased faster in the holidays (relative to the in-school period) in children who are overweight and from low-SES families. Aerobic fitness declined more rapidly in the holidays in children who are overweight. Conclusion This study highlights that during the summer holiday period, children experience greater increases in fatness and declines in fitness, with children who live with low-SES families and are overweight being more affected. The findings suggest the need for targeted interventions during this period to address these negative health trends. Trial registration Australia New Zealand Clinical Trials Registry, identifier ACTRN12618002008202. Retrospectively registered on 14 December 2018.
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- 2023
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10. Effect of Summer Holiday Programs on Children’s Mental Health and Well-Being: Systematic Review and Meta-Analysis
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Emily Eglitis, Catherine Simpson, Ben Singh, Timothy Olds, Amanda Machell, Rosa Virgara, Mandy Richardson, Kylie Brannelly, Aniella Grant, Jessica Gray, Terri Wilkinson, Zoe Rix, and Carol Maher
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summer camps ,children ,mental health ,anxiety ,depression ,distress ,Pediatrics ,RJ1-570 - Abstract
Poor youth mental health is an area of global concern. Summer holiday programs may provide environments that support mental health when the structures and supports of school are not available. The aim of this review was to determine the effectiveness of summer holiday programs in improving the mental health, social–emotional well-being, and cognitive (non-academic) outcomes of children and adolescents. Studies of summer holiday programs for school-aged children (5–18 years) were included if they measured any mental, socio-emotional or cognitive (non-academic) outcome. Studies were excluded if they were published prior to 2000, targeted clinical populations or lasted less than five days. Six databases were searched (April 2023). Risk of bias was assessed using the PEDro tool. Study outcomes were grouped according to three main constructs: mental health (psychological well-being, anxiety, depression, distress, and self-perception including self-esteem, self-worth, self-concept, confidence, and competence); social–emotional well-being (behavior and social skills, e.g., communication, bullying, conflict resolution, empathy, and social skills); and cognitive function (memory, selective attention, and executive function). A fourth “other” group captured substance use, personality traits, character skills, and values. Effect sizes were calculated as the standardized mean difference between pre- and post-intervention scores. The synthesis involved a random-effects meta-analysis (presented in forest plots), where possible, with the remaining outcomes narratively synthesized. Twenty-six studies (n = 6812 participants) were included. The results of the meta-analysis suggested that summer programs showed a statistically non-significant trend toward reducing symptoms of anxiety and depression (k = 2 studies, SMD = −0.17, 95% CI −2.94, 2.60), psychological distress (k = 2 studies, SMD −0.46, 95% CI –1.71, 0.79), and no effect on self-esteem (k = 6 studies, SMD = 0.02, 95% CI −0.02, 0.06) or self-worth (k = 3 studies, SMD = 0.05, 95% CI 0.00, 0.11). Narrative syntheses indicated a pattern toward improvements in general mental health, self-perception, social–emotional outcomes, and cognition. Studies were generally small, with a high risk of bias. Summer holiday programs for children and adolescents show trends toward improving mental, social, emotional, and cognitive outcomes. Programs targeting disadvantaged children showed stronger patterns of improvement related to mental health and self-perception than programs targeting the general population. While effect sizes are small to negligible, they consistently indicate improvements. Summer programs present a promising avenue to promote mental health in children; however, further rigorously designed, clearly reported control-group studies are required to more fully understand their effects.
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- 2024
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11. Women’s Experiences of Life Force Atrocities in the Baltic Ghettos, 1941–1944
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Eglitis Daina S.
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baltic ghettos ,genocide and sexual violence ,holocaust in the baltics ,nazi ghettos ,women in the holocaust ,History of Eastern Europe ,DJK1-77 - Abstract
This article focuses on Jewish women in the Nazi ghettos of German-occupied Latvia and Lithuania. It uses testimonies and memoirs of survivors to develop a narrative about life force atrocities at these sites, highlighting ways in which being a Jewish woman shaped the experience of the ghettos, where gendered risks were ubiquitous. Being a woman in the ghettos meant being both exploited and undervalued as a source of physical labor, targeted as a potential or actual bearer of children, and violated as an object of racist and sexist ideology and rage. Life force atrocities have physical and symbolic dimensions, targeting bodies, bonds, and norms of the community. This work considers what women’s accounts tell us about the presence – or ubiquity – of life force atrocities in the Baltic ghettos. It draws on the concepts of the universe of obligation and social death to highlight key roots and consequences of these atrocities for women. In testimonies and memoirs, we encounter themes of pregnancy, forced abortion, the wrenching loss of loved ones, sexual violence, and decisions made in the desperate hope of saving oneself or another. Survivor accounts are key to revealing life force atrocities as defining features of the Nazi ghettos, and the gendered risks faced by women prisoners in Nazi-occupied Riga, Daugavpils, and Kaunas.
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- 2023
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12. Light curve analysis of main belt asteroids 4747, 5255, 11411, 15433, 17866
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Eglitis Ilgmars and Kristers Nagainis
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main belt asteroids ,light curve ,rotation period ,Astronomy ,QB1-991 - Abstract
The main belt asteroids 4747, 5255, 11411, 15433, and 17866 were studied at the Baldone Astrophysical Observatory in the time span range 2018–2022. The obtained light curve data together with published Minor Planet Center data are analyzed with Fourier series, Lomb-Scargle periodogram, and phase dispersion minimization methods. A plan of analysis is given. The results computed from different observatories’ data are compared, and mean-weighted periods are obtained.
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- 2023
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13. Changes in fitness and fatness in Australian schoolchildren during the summer holidays: fitness lost, fatness regained? A cohort study
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Olds, Tim, Dumuid, Dorothea, Eglitis, Emily, Golley, Rebecca, Fraysse, François, Miatke, Aaron, Tomkinson, Grant R., Watson, Amanda, Munzberg, Mason, and Maher, Carol
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- 2023
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14. Systematic review and meta-analysis of the effectiveness of chatbots on lifestyle behaviours
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Singh, Ben, Olds, Timothy, Brinsley, Jacinta, Dumuid, Dot, Virgara, Rosa, Matricciani, Lisa, Watson, Amanda, Szeto, Kimberley, Eglitis, Emily, Miatke, Aaron, Simpson, Catherine E. M., Vandelanotte, Corneel, and Maher, Carol
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- 2023
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15. Systematic review and meta-analysis of the effectiveness of chatbots on lifestyle behaviours
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Ben Singh, Timothy Olds, Jacinta Brinsley, Dot Dumuid, Rosa Virgara, Lisa Matricciani, Amanda Watson, Kimberley Szeto, Emily Eglitis, Aaron Miatke, Catherine E. M. Simpson, Corneel Vandelanotte, and Carol Maher
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Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Chatbots (also known as conversational agents and virtual assistants) offer the potential to deliver healthcare in an efficient, appealing and personalised manner. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of chatbot interventions designed to improve physical activity, diet and sleep. Electronic databases were searched for randomised and non-randomised controlled trials, and pre-post trials that evaluated chatbot interventions targeting physical activity, diet and/or sleep, published before 1 September 2022. Outcomes were total physical activity, steps, moderate-to-vigorous physical activity (MVPA), fruit and vegetable consumption, sleep quality and sleep duration. Standardised mean differences (SMD) were calculated to compare intervention effects. Subgroup analyses were conducted to assess chatbot type, intervention type, duration, output and use of artificial intelligence. Risk of bias was assessed using the Effective Public Health Practice Project Quality Assessment tool. Nineteen trials were included. Sample sizes ranged between 25–958, and mean participant age ranged between 9–71 years. Most interventions (n = 15, 79%) targeted physical activity, and most trials had a low-quality rating (n = 14, 74%). Meta-analysis results showed significant effects (all p
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- 2023
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16. Influence of the Hubbard U Correction on the Electronic Properties and Chemical Bands of the Cubic (Pm3¯m) Phase of SrTiO3 Using GGA/PBE and LDA/CA-PZ Approximations
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Issam Derkaoui, Mohamed Achehboune, Roberts I. Eglitis, Anatoli I. Popov, Issam Boukhoubza, Mohamed A. Basyooni-M. Kabatas, and Abdellah Rezzouk
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STO ,DFT ,Hubbard U ,electronic properties ,band gaps ,chemical bonds ,Organic chemistry ,QD241-441 - Abstract
By using DFT simulations employing the GGA/PBE and LDA/CA-PZ approximations, the effects of the Hubbard U correction on the crystal structure, electronic properties, and chemical bands of the cubic phase (Pm3¯m) of STO were investigated. Our findings showed that the cubic phase (Pm3¯m) STO’s band gaps and lattice parameters/volume are in reasonably good accordance with the experimental data, supporting the accuracy of our model. By applying the DFT + U method, we were able to obtain band gaps that were in reasonably good agreement with the most widely used experimental band gaps of the cubic (Pm3¯m) phase of STO, which are 3.20 eV, 3.24 eV, and 3.25 eV. This proves that the Hubbard U correction can overcome the underestimation of the band gaps induced by both GGA/PBE and LDA/CA-PZ approximations. On the other hand, the Sr-O and Ti-O bindings appear predominantly ionic and covalent, respectively, based on the effective valence charges, electron density distribution, and partial density of states analyses. In an attempt to enhance the performance of STO for new applications, these results might also be utilized as theoretical guidance, benefitting from our precise predicted values of the gap energies of the cubic phase (Pm3¯m).
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- 2024
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17. Children’s Health, Wellbeing and Academic Outcomes over the Summer Holidays: A Scoping Review
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Emily Eglitis, Aaron Miatke, Rosa Virgara, Amanda Machell, Timothy Olds, Mandy Richardson, and Carol Maher
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child health ,physical activity ,obesity ,time use ,summer ,holidays ,Pediatrics ,RJ1-570 - Abstract
Background: The school day provides a supportive and stimulating environment that may protect children and adolescents (5–18 years) from behaviours that are adverse for health and wellbeing. Objective: To review the literature regarding changes in children’s academic achievement or overall wellbeing during the extended school summer break and evaluate if the outcomes are different for children experiencing disadvantage. Methods: The peer-reviewed literature was searched across six electronic databases for studies tracking changes in any academic, health or wellbeing outcome in children over the summer holidays. Studies were screened in duplicate for inclusion. Data were extracted using a standardized data extraction form. Outcomes were coded as decline (suggestive or significant), increase (suggestive or significant) or mixed/neutral and then compared to the school year or according to disadvantaged. Results: Seventy-six studies (n = 14,230,846 participants) were included. Strong evidence was found of a decline in academic outcomes and increases in adiposity, sedentary behaviour and screen time. There was moderate evidence of declines in cardiovascular fitness and physical activity. These patterns were magnified for disadvantaged children. Limited data were available on muscular fitness, sleep, diet quality and social, emotional or mental wellbeing. A total of 80% of studies were from the United States. Most data were from children 12 years of age and younger. Conclusions: Over the summer break, children’s academic and health outcomes decline. Children experiencing disadvantage display magnified losses that warrant further investigation. The summer holidays present an opportunity to improve children’s health and wellbeing.
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- 2024
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18. Physiologic risk stratification is important to long-term mortality, complications, and readmission in thoracic endovascular aortic repair
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Castigliano M. Bhamidipati, DO, PhD, MSc, FACS, Beth C. Tohill, MSPH, PhD, Charee Robe, MS, Kimberly J. Reid, MS, Nicholas C. Eglitis, MD, Mark A. Farber, MD, and William D. Jordan, Jr., MD
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Complications ,Discharge ,Mortality ,Rehospitalization ,Thoracic endovascular repair ,Surgery ,RD1-811 ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Use of the American Society of Anesthesiologists (ASA) physical status classification is important for periprocedural risk stratification. However, the collective effect after adjustment for the Society for Vascular Surgery (SVS) medical comorbidity grading system on long-term all-cause mortality, complications, and discharge disposition is unknown. We examined these associations in patients after thoracic endograft placement. Data from three thoracic endovascular aortic repair (TEVAR) trials through 5 years of follow-up were included. Patients with acute complicated type B dissection (n = 50), traumatic transection (n = 101), or descending thoracic aneurysm (n = 66) were analyzed. The patients were stratified into three groups according to the ASA class: I-II, III, and IV. Multivariable proportional hazards regression models were used to examine the effect of ASA class on 5-year mortality, complications, and rehospitalizations after adjustment for SVS risk score and potential confounders. The largest proportion of patients treated by TEVAR across the ASA groups (n = 217) was ASA IV (n = 97; 44.7%; P < .001), followed by ASA III (n = 83; 38.2%) and ASA I-II (n = 37; 17.1%). Among the ASA groups, the ASA I-II patients were, on average, 6 years younger than those with ASA III and 3 years older than those with ASA IV (ASA I-II: age, 54.3 ± 22.0 years; ASA III: age, 60.0 ± 19.7 years; ASA IV: age, 51.0 ± 18.4 years; P = .009). Multivariable adjusted 5-year outcome models showed that ASA class IV, independent of the SVS score, conferred an increased risk of mortality (hazard ratio [HR], 3.83; 95% confidence interval [CI], 1.19-12.25; P = .0239) and complications (HR, 4.53; 95% CI, 1.69-12.13; P = .0027) but not rehospitalization (HR, 1.84; 95% CI, 0.93-3.68; P = .0817) compared with ASA class I-II. Procedural ASA class is associated with long-term outcomes among post-TEVAR patients, independent of the SVS score. The ASA class and SVS score remain important to patient counseling and postoperative outcomes beyond the index operation.
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- 2023
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19. Chiisanoside from the Leaves of Acanthopanax sessiliflorus Can Resist Cisplatin-Induced Ototoxicity by Maintaining Cytoskeletal Homeostasis and Inhibiting Ferroptosis.
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Teng, Hongbo, Sun, Xialin, Eglitis, Roberts, Wang, Xv, Zhang, Wenxin, Wang, Haijing, Qu, Shurong, Yu, Zhengxuan, Liu, Shuangli, and Zhao, Yan
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- 2024
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20. Study of the Rapid Variability of the BL Lac Object MRK 421 in the Optical Range
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Sukharev, A., Ryabov, M., Bezrukovs, V., Ul’yanov, O., Udovichenko, S., Keir, L., Dubovskii, P., Kudzej, I., Konovalenko, A., Zakharenko, V., Bakun, D., and Eglitis, I.
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- 2022
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21. Control of Strongly Nonequilibrium Coherently Correlated States and Superconducting Transition Temperature
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Sergei P. Kruchinin, Roberts I. Eglitis, Valery E. Novikov, Andrzej M. Oleś, and Steffen Wirth
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strongly nonequilibrium distributions ,coherent acceleration ,coherently correlated states ,energy flow in the phase space ,phase transition temperature ,Mathematics ,QA1-939 - Abstract
Our paper considers the possibility of the emergence and control of non-equilibrium states of a quasi-homogenous condensed medium with energy and particle flows in the phase space, which, first of all, manifest themselves in the explosive development of the asymmetry in the initially symmetric equilibrium system. This symmetry breaking and the appearance of non-equilibrium in the system are controlled by the coherent acceleration of the system. Dependencies of thermodynamic parameters of a strong nonequilibrium system on the indices of disequilibrium in coherently correlated states are given, and the estimates of the dielectric permittivity in a non-equilibrium system and modes of plasma acoustic oscillations are made. An estimate of the superconducting transition temperature under nonequilibrium conditions has been made. It is demonstrated that the superconducting transition temperature can approach the limiting value, corresponding to a quantum with its plasma frequency of the medium.
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- 2023
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22. Review of First Principles Simulations of STO/BTO, STO/PTO, and SZO/PZO (001) Heterostructures
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Roberts I. Eglitis, Dmitry Bocharov, Sergey Piskunov, and Ran Jia
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STO/BTO (001) interface ,STO/PTO (001) heterostructure ,SZO/PZO (001) interface ,Γ-Γ band gap ,B-O bond covalency ,Crystallography ,QD901-999 - Abstract
In this study, we review our first-principles simulations for STO/BTO, STO/PTO, and SZO/PZO (001) heterostructures. Specifically, we report ab initio B3PW calculations for STO/BTO, STO/PTO, and SZO/PZO (001) interfaces, considering non-stoichiometric heterostructures in the process. Our ab initio B3PW calculations demonstrate that charge redistribution in the (001) interface region only subtly affects electronic structures. However, changes in stoichiometry result in significant shifts in band edges. The computed band gaps for the STO/BTO, STO/PTO, and SZO/PZO (001) interfaces are primarily determined according to whether the topmost layer of the augmented (001) film has an AO or BO2 termination. We predict an increase in the covalency of B-O bonds near the STO/BTO, STO/PTO, and SZO/PZO (001) heterostructures as compared to the BTO, PTO, and PZO bulk materials.
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- 2023
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23. Theoretical Study on (n,n)-Nanotubes Rolled-up from B/N Substituted Me-Graphene
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Hong-Chao Luo, Feng-Yin Li, Ya-Nan Zhang, Hong-Xing Zhang, Roberts I. Eglitis, and Ran Jia
- Subjects
Me-graphene ,nanotube ,substitution ,bloch flat band ,DFT ,Crystallography ,QD901-999 - Abstract
In this work, the n,n-type nanotube systems rolled up from the B/N substituted Me-graphene (i.e., Me-CBNT and Me-CNN, respectively) were investigated with the aid of the density functional theory (DFT). Due to the lattice dynamic instabilities until n=10, the n,0 and n,m nanotube systems were not involved in this study. According to our calculations at the Perdew-Burke-Ernzerhof (PBE) level, the n,n Me-CBNT and Me-CNNT systems possess excellent mechanical strengths. The Young’s moduli of Me-CBNTs can reach 60% of single-walled carbon nanotubes (SWCNTs), while their mass densities are only around 70% of SWCNTs. Based on the fully relaxed geometric configurations at the PBE level, the electronic configurations of the related nanotubes were evaluated by using the global hybrid functional B3LYP with 36% Fock exchanges. The n,n Me-CBNTs are metallic, while the n,n Me-CNNTs are semiconductors with the inherent band gaps in the range of 3.08 eV to 3.31 eV. The Bloch flat bands appear on both sides of their Fermi levels, indicating the localized charge carriers. Their band edge arrangements imply that these materials are promising candidates for the photocatalytic water splitting reactions at certain pH values.
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- 2023
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24. Astrometry and photometry of digitized plates of Baldone Schmidt telescope
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Eglitis Ilgmars and Andruk Vitaly
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astronegative ,scanning ,processing of digitized records ,characteristic curve ,ubvr photometry ,bp ,rp gaia dr2 ,asteroids ,pluto ,Astronomy ,QB1-991 - Abstract
During the 40-year photographic period of astronomical observations, the Baldone Astrophysical Observatory has accumulated more than 22,000 direct and 2,500 spectral images. In 2018, the digitization of direct astrophoto images with a resolution of 1200 dpi was completed. A processing methodology for obtaining the equatorial coordinates and photometric characteristics of the objects recorded in digitized astronegatives using the LINUX/MIDAS/ROMAFOT environment has been developed at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. Program package with success already works in seven observatories. A description of the operation of this program complex in stages and analysis of the obtained results is given. The steps describe the astrometric and photometric reduction process of digital records, as well as the reduction of the obtained instrumental magnitudes to the Johnson UBVR photometric system. The methodology of characteristic curve construction in the case of one exposure is described in detail. From all digitized astrophotoplates to date Approximately 2200 V film negatives, 300 U plates and several R, B plates were processed. As a result, catalogs of the positions and magnitudes of Pluto, 1848 asteroids and comets were obtained. 31 new positions were recorded in the VizieR Pluto catalog VI/155. It was found that the root-mean-square errors of the reduction of the measured coordinates to the equatorial coordinate system of the Tycho-2 catalog have values σRA,DEC= 0.1-0.2”, and the root-mean-square errors of the reduction of instrumental photometric quantities m to the Johnson system of stellar UBVR-values are also in within σUBVR = 0.1 − 0.2m.
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- 2021
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25. Co-doping with boron and nitrogen impurities in T-carbon
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Zhen-Wei Tian, Xiao-Qian Cui, Jia-Kun Tian, Mu-Chen Cui, Li Jin, Ran Jia, and Roberts I. Eglitis
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T-carbon ,Doping ,BN pair ,DFT ,Chemistry ,QD1-999 - Abstract
Previously, Ren et al. [Chem. Phys. 518, 69–73, 2019] reported the failure of Boron-Nitrogen (B-N) co-doping as inter B-N bond in T-carbon. In present work, a B-N atom pair is introduced in T-carbon as p-n co-dopant to substitute two carbon atoms in the same carbon tetrahedron and form an intra B-N bond. The stability of this doping system is verified from energy, lattice dynamic, and thermodynamic aspects. According to our B3PW calculations, B-N impurities in this situation can reduce the band gap of T-carbon from 2.95 eV to 2.55 eV, making this material to be a promising photocatalyst. Through the study of its transport properties, we can also conclude that B-N co-doping cannot improve the thermoelectric performance of T-carbon.
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- 2020
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26. Observational data and orbits of the asteroids discovered at the Baldone Observatory in 2015–2018
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Wlodarczyk Ireneusz, Černis Kazimieras, and Eglitis Ilgmars
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minor planets ,asteroids: search ,astrometry ,orbits ,Astronomy ,QB1-991 - Abstract
This paper is devoted to the discovery of 37 asteroids at the Baldone Astrophysical Observatory (MPC 069) from 2015 to 2018, and one of dynamically interesting Mars-crosser (MC) observed at the Baldone Astrophysical Observatory, namely 2008 LX16. In Baldone Observatory, was independently discovered the Near-Earth Object 2018 GE3 on the image of 13 April 2018. Also, the NEO 2006 VB14 was observed doing its astrometry and photometry. Moreover, we observed asteroids 1986 DA and 2014 LJ1. We computed orbits and analyzed the orbital evolution of these asteroids. 566 positions and photometric observations of NEO objects 345705 (2006 VB14) and 6178 (1986 DA) were obtained with Baldone Schmidt telescope in 2018 and 2019. We detected their rotation period and other physical characteristics. Also, a Fourier transform was applied to determine the rotation period of asteroid 6178 (1986 DA). Value (3.12 ± 0.02)h was obtained. Our observations confirm the previously obtained rotation periodP=3.25hfor2006VB14.
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- 2020
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27. Kinetics of TiO2 photochromic response in different hole scavenging solvents
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Eglitis, Raivis, Zukuls, Anzelms, Viter, Roman, and Sutka, Andris
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- 2020
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28. Ab initio calculations of CaZrO3 (011) surfaces: systematic trends in polar (011) surface calculations of ABO3 perovskites
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Eglitis, Roberts I., Kleperis, J., Purans, J., Popov, A. I., and Jia, Ran
- Published
- 2020
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29. Systematic Trends in Hybrid-DFT Computations of BaTiO3/SrTiO3, PbTiO3/SrTiO3 and PbZrO3/SrZrO3 (001) Hetero Structures
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Roberts I. Eglitis, Sergei Piskunov, Anatoli I. Popov, Juris Purans, Dmitry Bocharov, and Ran Jia
- Subjects
ABO3 perovskites ,(001)interfaces ,BaTiO3/SrTiO3 ,PbTiO3/SrTiO3 ,SrZrO3/PbZrO3 ,Physics ,QC1-999 - Abstract
We performed predictive hybrid-DFT computations for PbTiO3, BaTiO3, SrTiO3, PbZrO3 and SrZrO3 (001) surfaces, as well as their BaTiO3/SrTiO3, PbTiO3/SrTiO3 and PbZrO3/SrZrO3 (001) heterostructures. According to our hybrid-DFT computations for BO2 and AO-terminated ABO3 solid (001) surfaces, in most cases, the upper layer ions relax inwards, whereas the second layer ions shift upwards. Our hybrid-DFT computed surface rumpling s for the BO2-terminated ABO3 perovskite (001) surfaces almost always is positive and is in a fair agreement with the available LEED and RHEED experiments. Computed B-O atom chemical bond population values in the ABO3 perovskite bulk are enhanced on its BO2-terminated (001) surfaces. Computed surface energies for BO2 and AO-terminated ABO3 perovskite (001) surfaces are comparable; thus, both (001) surface terminations may co-exist. Our computed ABO3 perovskite bulk Γ-Γ band gaps are in fair agreement with available experimental data. BO2 and AO-terminated (001) surface Γ-Γ band gaps are always reduced with regard to the respective bulk band gaps. For our computed BTO/STO and PTO/STO (001) interfaces, the average augmented upper-layer atom relaxation magnitudes increased by the number of augmented BTO or PTO (001) layers and always were stronger for TiO2-terminated than for BaO or PbO-terminated upper layers. Our B3PW concluded that BTO/STO, as well as SZO/PZO (001) interface Γ-Γ band gaps, very strongly depends on the upper augmented layer BO2 or AO-termination but considerably less so on the number of augmented (001) layers.
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- 2022
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30. ON THE 'SOLAR SYSTEM SMALL BODIES' ASTROPLATE PROJECT OF THE UKRAINIAN VIRTUAL OBSERVATORY
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S V. Shatokhina, O. M. Yizhakevych, Yu. I. Protsyuk, L. V. Kazantseva, L. K. Pakuliak, I. Eglitis, H. Relke, Q. X. Yuldoshev, A. Sh. Mullo-Abdolov, and V. M. Andruk
- Subjects
Astronomy ,QB1-991 - Abstract
The UkrVO Joint Digital Archive of astro- plates and the newest digitized data processing services al- lowed us to form a new approach for the creation of catalogs of astrometric and photometric characteristics of the Solar System bodies. Given this, the main goal of this approach was not only to complete the processing with the best possi- ble accuracy of high-quality and unprocessed earlier photo- graphic observations of the Solar System bodies but also to find new original data from these observations. As a result, more than 6,500 new astrometric positions and stellar magnitudes of asteroids, and 3,036 positions of outer planets (Pluto, Uranus, Neptune, Saturn, Jupiter) and their satellites have been determined. Most of the posi- tions obtained from observations of large stellar surveys of the northern sky FON (Kyiv and Kitab parts) and other surveys (MEGA, Equatorial Catalog). The number of new obtained positions of asteroids is comparable to the total number of all positions of aster- oids obtained at the Main Astronomical Observatory of the NAS of Ukraine in 1949-1996. The accuracy of new positions is higher than in traditional determinations from photographic observations, but it cannot be comparable to the accuracy of modern CCD observations. Contrary to traditional classic definitions, digitized im- ages of plates have produced a large number of faint aster- oids down to 17.5 magnitudes, which were discovered in the early 21st century. For some of them, observations are either completely absent or not enough over the certain time interval preceding the moments of their official discoveries. These data can be obtained from photographic observations only. Based on our observations, about 300 such asteroids were found. The collection of missing data on positions over certain time intervals and their analysis can be useful not only for modern ephemeris calculations but also for studying the evolution of asteroid orbits over time. The cooperation between UkrVO and the observatory in Baldone of the University in Latvia, astronomical and astro- physical institutes of Uzbekistan and Tajikistan make it pos- sible to expand this work by involving numerous additional archives of digitized observations and processing services and thus obtaining new original data about the Universe.
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- 2019
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31. BALDONE OBSERVATORY IN THE CIRCLES OF TIME
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I. Eglitis
- Subjects
Astronomy ,QB1-991 - Abstract
1957 – The first laboratory building, known as the White House, was built near Baldone on the Riekstu hill, in the territory of the next Observatory. 01.01.1958 – The Astronomy Sector was separated from the Institute of Physics and commenced independent activi- ty as the Laboratory of Astrophysics at the Latvian Acade- my of Sciences (LAS). In 1967, with the decision of the Presidium of the Latvian SSR LAS the Laboratory of As- trophysics was transformed into the Radioastrophysic Ob- servatory at LAS. Under the leadership of the first director, Janis Ikaunieks, an instrumental observation base develops – a 1.2m Schmidt telescope was installed in 1966 for opti- cal observations. The project of the variable base radio in- terferometer after the death of J. Ikaunieks was unrealized. To continue astronomical observations in radio range, in 1972 10m radio telescope RT-10 was purchased. Non-stationary processes and spectral research of car- bon stars are associated with the study in optic range de- velops following the plan of J.Ikaunieks. After the estab- lishment of the UL Institute of Astronomy in 1997, the field of research in the optical range is supplemented by the research direction of small objects of the solar system. However, the area of radio astronomy has stopped due to lack of funding. The scientific potential of the Baldone Observatory re- mains significant. It should be mentioned that the 22,000 Schmidt telescope astroplate archive obtained in 1967- 2005, will be digitized entirely this year. After digital im- age processing, coordinates and brightness for about of 330,000,000 objects will be obtained. The database will contain details of star movement, brightness variability (both long-term and short-term) and details of known, unknown asteroids and comets. In 2008, monitoring of asteroids in the Solar System is started in Observatory. Up till now 77 new asteroids have been discovered in the Solar System and 11 of them have been named. Research on carbon stars is still continuing successfully. The number of carbon stars currently discovered has reached 400. A methodology has been created for estimat- ing the temperature and distance to the carbon stars. Work is currently underway to improve this method. Observatory is continuing its work on popularizing as- tronomy. Number of visitors per year has risen from 1000 in 90s to almost four thousand in 2018.
- Published
- 2019
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32. ON THE FON ASTROPLATE PROJECT ACCOMPLISHMENT
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V. M. Andruk, L. K. Pakuliak, I. Eglitis, Q. Yuldoshev, A. Mullo-Abdolov, S. V. Shatokhina, O. M. Yizhakevych, Yu. I. Protsyuk, H. Relke, V. S. Akhmetov, M. M. Muminov, Sh. A. Ehgamberdiev, and G. Kokhirova
- Subjects
зоряні каталоги, обробка оцифрова- них зображень, фотометрія, система ubv ,Astronomy ,QB1-991 - Abstract
The plan of the photographic survey of the northern sky (FON) was proposed in 1976 in Golosiiv ob- servatory (now MAO NAS of Ukraine) by I. Kolchinsky and A. Onegina. The final project of the Compiled FONAC catalog (FON Astrographic Catalog) is based on the digital data of photographic plates exposed at four observatories. They are MAO NAS of Ukraine (Kyiv, Ukraine), Kitab astronomical observatory (Tashkent, Uzbekistan), Hissar astronomical observatory (Dushanbe, Tajikistan), and Bal- done observatory (Latvia)). The total amount of plates is 5700. The result is expected to be the catalog of positions and B-magnitudes of stars covered the declination area from -20 to 90 degrees. The estimated mean epoch of the catalog is ~1987. The limiting B-magnitude is ~17.5 m . The reference system for positions is Tycho-2. B-magnitudes are being obtained in the system of photoelectric standards. The resulted data of photometric reduction are corrected for the photometric color equation in B magnitudes. The com- plement for the photometric content of the catalog is U and V magnitudes of stars being obtained from the processing of 5400 plates from the glass collection of 1.2 m Schmidt telescope in Baldone. Photometric data of bright stars with V < 8.5 m U, B,V magnitudes cannot be obtained from pho- tographic material, so those objects will gain photometric data from photoelectric catalogs. The catalog will be com- plemented with proper motions from GAIA.
- Published
- 2019
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33. PHOTOMETRY OF STARS FOR ASTRONEGATIVES WITH A SINGLE EXPOSURE
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V. Andruk, I. Eglitis, Yu. Protsyuk, V. Akhmetov, L. Pakuliak, S. Shatokhina, and O. Yizhakevych
- Subjects
Astronomy ,QB1-991 - Abstract
The paper discusses the construction of characteristic curves for various astronegatives with a single exposure. Particular attention is paid to the question of extrapolation of the characteristic curve for the region of the weakest stars in the absence of standards. A new method for constructing an individual characteristic curve for digitized films and plates in the UBVR system has been proposed and implemented. The processing of frames of digitized plates and films with sky areas is car- ried out using LINUX/MIDAS/ROMAFOT software tools. ROMAFOT application allows us to extract astro- metric rectangular coordinates X,Y and photometric char- acteristics such as instrumental photometric magnitudes m, FWHM, and the intensity in the center of the star im- age I c for all fixed objects on each astronegative. For all frames, the connection between instrumental photometric values m with stellar magnitudes in any system (Johnson UBVR, Tycho-2 or GAIA catalogs, etc.) is not linear and multipurpose. It is presented as the characteristic curve for each astronegative. Currently, the determination of U, B, V, R magnitudes of stars and other space objects is in pro- gress for astronegatives with the single exposure obtained in the frameworks of selected observational projects.
- Published
- 2019
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34. PROBING BREAST CANCER THERAPEUTIC RESPONSES BY DNA CONTENT PROFILING
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B. I. Gerashchenko, K. Salmina, J. Eglitis, and J. Erenpreisa
- Subjects
breast cancer ,polyploid cells ,near-triploidy ,DNA content profiling ,therapeutic response ,cancer stem cells ,Medicine - Abstract
Background. Discrepancies in the interpretation of breast cancer therapeutic responses still exist mainly because of lack of standardized assessment criteria and methods. Objective. DNA content profiling of cells in the affected (cancerous) tissue before and after neoadjuvant chemotherapy (NAC) was applied to facilitate interpretation of therapeutic responses. Methods. Both diagnostic biopsy and operation materials representing the tissue of primary tumors surgically removed after NAC were subjected to DNA image cytometry. Polyploidy and aneuploidy in DNA histograms were evaluated with a prognostic Auer typing. Stemline DNA index (DI) values and percentages of cells that polyploidize (>4.5C) were also determined. Immunofluorescence staining was applied to evaluate proliferation (Ki-67), invasiveness (CD44), and self-renewal factors characteristic for stem cells (SOX2 and NANOG). Results. DNA content profiles of 12 breast cancer cases, of which 7 were triple-negative, revealed the features of tumor non-responsiveness to NAC in 7 cases, of which 5 were triple-negative. Among non-responsive cases there were 3 cases that showed enhanced polyploidization, suggesting the negative NAC effect. Near-triploid (DI=1.26-1.74) triple-negative cases were determined as most resistant to NAC. Cycling near-triploid cells may contribute to the excessive numbers of >4.5C cells. Polyploid cells were positive for Ki-67, CD44, SOX2, and NANOG. Conclusions. DNA content profiling data provide additional helpful information for interpreting therapeutic responses in NAC-treated breast cancers. Polyploid tumor cells possessing stem cell features can be induced by NAC. Because NAC effects in some cases may be unfavorable, the use of the further treatment strategy should be carefully considered.
- Published
- 2019
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35. Ab initio calculations of the atomic and electronic structure of CaTiO3 (001) and (011) surfaces
- Author
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Eglitis, R. I. and Vanderbilt, David
- Subjects
Condensed Matter - Materials Science - Abstract
We present the results of calculations of surface relaxations, energetics, and bonding properties for CaTiO3 (001) and (011) surfaces using a hybrid B3PW description of exchange and correlation. We consider both CaO and TiO2 terminations of the non-polar (001) surface, and Ca, TiO and O terminations of the polar (011) surface. On the (001) surfaces, we find that all upper-layer atoms relax inwards on the CaO-terminated surface, while outward relaxations of all atoms in the second layer are found for both terminations. For the TiO2-terminated (001) surface, the largest relaxations are on the second-layer atoms. The surface rumpling is much larger for the CaO-terminated than for the TiO2-terminated (001) surface, but their surface energies are quite similar at 0.94eV and 1.13eV respectively. In contrast, different terminations of the (011) CaTiO3 surface lead to very different surface energies of 1.86eV, 1.91eV, and 3.13eV for the O-terminated, Ca-terminated, and TiO-terminated (011) surface respectively. Our results for surface energies contrast sharply with those of Zhang et al. [Phys. Rev. B 76, 115426 (2007)], where the authors found a rather different pattern of surface energies. We predict a considerable increase of the Ti-O chemical bond covalency near the (011) surface as compared both to the bulk and to the (001) surface., Comment: 11 pages
- Published
- 2008
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36. Ab initio calculations of BaTiO3 and PbTiO3 (001) and (011) surface structure
- Author
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Eglitis, R. I. and Vanderbilt, David
- Subjects
Condensed Matter - Materials Science - Abstract
We present and discuss the results of calculations of surface relaxations and rumplings for the (001) and (011) surfaces of BaTiO3 and PbTiO3, using a hybrid B3PW description of exchange and correlation. On the (001) surfaces, we consider both AO (A = Ba or Pb) and TiO2 terminations. In the former case, the surface AO layer is found to relax inward for both materials, while outward relaxations of all atoms in the second layer are found at both kinds of (001) terminations and for both materials. The surface relaxation energies of BaO and TiO2 terminations on BaTiO3 (001) are found to be comparable, as are those of PbO and TiO2 on PbTiO3 (001), although in both cases the relaxation energy is slightly larger for the TiO2 termination. As for the (011) surfaces, we consider three types of surfaces, terminating on a TiO layer, a Ba or Pb layer, or an O layer. Here, the relaxation energies are much larger for the TiO-terminated than for the Ba or Pb-terminated surfaces. The relaxed surface energy for the O-terminated surface is about the same as the corresponding average of the TiO and Pb-terminated surfaces on PbTiO3, but much less than the average of the TiO and Ba-terminated surfaces on BaTiO3. We predict a considerable increase of the Ti-O chemical bond covalency near the BaTiO3 and PbTiO3 (011) surface as compared to both the bulk and the (001) surface., Comment: 9 pages. Accepted for publication in Physical Review B
- Published
- 2007
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37. Ab Initio Computations of O and AO as well as ReO2, WO2 and BO2-Terminated ReO3, WO3, BaTiO3, SrTiO3 and BaZrO3 (001) Surfaces
- Author
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Roberts I. Eglitis, Juris Purans, Anatoli I. Popov, Dmitry Bocharov, Anastasiia Chekhovska, and Ran Jia
- Subjects
ab initio methods ,(001) surfaces ,ReO3 ,WO3 ,BaTiO3 ,SrTiO3 ,Mathematics ,QA1-939 - Abstract
We present and discuss the results of surface relaxation and rumpling computations for ReO3, WO3, SrTiO3, BaTiO3 and BaZrO3 (001) surfaces employing a hybrid B3LYP or B3PW description of exchange and correlation. In particular, we perform the first B3LYP computations for O-terminated ReO3 and WO3 (001) surfaces. In most cases, according to our B3LYP or B3PW computations for both surface terminations BO2- and O, AO-terminated ReO3, WO3, BaTiO3, SrTiO3 and BaZrO3 (001) surface upper layer atoms shift downwards, towards the bulk, the second layer atoms shift upwards and the third layer atoms, again, shift downwards. Our ab initio computes that ReO3, WO3, BaTiO3, SrTiO3 and BaZrO3 (001) surface Γ-Γ bandgaps are always smaller than their respective bulk Γ-Γ bandgaps. Our first principles compute that B-O atom chemical bond populations in the BaTiO3, SrTiO3 and BaZrO3 perovskite bulk are always smaller than near their BO2-terminated (001) surfaces. Just opposite, the Re-O and W-O chemical bond populations in the ReO3 (0.212e) and WO3 (0.142e) bulk are slightly larger than near the ReO2 and WO2-terminated ReO3 as well as WO3 (001) surfaces (0.170e and 0.108e, respectively).
- Published
- 2022
- Full Text
- View/download PDF
38. Theory of bound polarons in oxide compounds
- Author
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Devreese, J. T., Fomin, V. M., Pokatilov, E. P., Kotomin, E. A., Eglitis, R., and Zhukovskii, Yu. F.
- Subjects
Condensed Matter - Strongly Correlated Electrons ,Condensed Matter - Statistical Mechanics - Abstract
We present a multilateral theoretical study of bound polarons in oxide compounds MgO and \alpha-Al_2O_3 (corundum). A continuum theory at arbitrary electron-phonon coupling is used for calculation of the energies of thermal dissociation, photoionization (optically induced release of an electron (hole) from the ground self-consistent state), as well as optical absorption to the non-relaxed excited states. Unlike the case of free strong-coupling polarons, where the ratio \kappa of the photoionization energy to the thermal dissociation energy was shown to be always equal to 3, here this ratio depends on the Froehlich coupling constant \alpha and the screened Coulomb interaction strength \beta. Reasonable variation of these two parameters has demonstrated that the magnitude of \kappa remains usually in the narrow interval from 1 to 2.5. This is in agreement with atomistic calculations and experimental data for hole O^- polarons bound to the cation vacancy in MgO. The thermal dissociation energy for the ground self-consistent state and the energy of the optically induced charge transfer process (hops of a hole between O^{2-} ions) have been calculated using the quantum-chemical method INDO. Results obtained within the two approaches for hole O$^-$ polarons bound by the cation vacancies (V^-) in MgO and by the Mg^{2+} impurity (V_{Mg}) in corundum are compared to experimental data and to each other. We discuss a surprising closeness of the results obtained on the basis of independent models and their agreement with experiment., Comment: 13 pages, 2 figures, 2 tables, E-mail addresses: devreese@uia.ua.ac.be, fomin@uia.ua.ac.be
- Published
- 2001
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39. Effects of Electron Correlation inside Disordered Crystals
- Author
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Sergei P. Kruchinin, Roberts I. Eglitis, Vitaliy P. Babak, Iryna G. Vyshyvana, and Stanislav P. Repetsky
- Subjects
new theory ,electron correlation ,electron spectrum ,Hamiltonian of electrons ,thermodynamic potential ,Crystallography ,QD901-999 - Abstract
We propose a novel approach for characterising the electron spectrum of disordered crystals constructed from a Hamiltonian of electrons as well as phonons and a diagram approach for Green’s function. The system’s electronic states were modelled by means of the multi-band, tight-binding approach. The system’s Hamiltonian is described based on the electron wave functions at the field of the atom nucleus. Our novel approach incorporates the long-range Coulomb interplay of electrons located in different lattice positions. Explicit interpretations of Green’s functions are derived using a diagram method. Equations are obtained for the vertex components for the mass operators of the electron–electron as well aselectron–phonon interplays. A system of equations for the spectrum of elementary excitations in the crystal is obtained, in which the vertex components for the mass operators of electron–electron as well as electron–phonon interplays are renormalised. Thismakes it possible to perform numerical computationsfor the system’s energy spectrum with a predetermined accuracy. In contrast to other approaches in which electron correlations are only taken into account in the limiting cases of an infinitely large and infinitesimal electron density, in this method, electron correlations are described in the general case of an arbitrary density. We obtained the cluster expansion of the density of states (DOS) of the disordered systems. We demonstrate that the addition of the electron-scattering mechanismsto the clusters is decreasing. This happens due to a growing number of positions in the cluster, which hang ontothe small parameter. The computing exactness is fixed by a small parameter for cluster expansion of Green’s functions of electrons as well as phonons.
- Published
- 2022
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- View/download PDF
40. Clinicopathological Significance of Exosomal Proteins CD9 and CD63 and DNA Mismatch Repair Proteins in Prostate Adenocarcinoma and Benign Hyperplasia
- Author
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Kristofs Folkmanis, Elizabete Junk, Evelina Merdane, Inese Folkmane, Valdis Folkmanis, Igors Ivanovs, Janis Eglitis, Maris Jakubovskis, Sven Laabs, Sergejs Isajevs, and Vilnis Lietuvietis
- Subjects
exosomal biomarkers ,DNA mismatch repair proteins ,prostate acinar adenocarcinoma ,benign prostate hyperplasia ,Medicine (General) ,R5-920 - Abstract
Introduction. Recently, it has been shown that exosomal biomarkers and DNA mismatch repair proteins (MMR) could play an important role in cancer risk stratification and prognosis assessment. The gold standard for prostate carcinoma (PCa) diagnosis is biopsy and histopathological examination. Thus, the complex evaluation of exosomal and MMR proteins could be beneficial for prostate cancer risk stratification and diagnostics. The aim of the current study was to evaluate and compare the expression of exosomal proteins CD9 and CD63 and MMR proteins in the tissue of patients with prostate benign hyperplasia (BPH) and PCa. Methods. The study was retrospective. Altogether, 92 patients with PCa and 20 patients with BPH (control group) were enrolled in the study. Exosomal and MMR protein expression was analyzed by immunohistochemistry (IHC). The follow-up for each PCa patient in our study lasted till disease progression and/or a maximum of 5 years. Results. Low-grade PCa was observed in 56 patients and high-grade PCa in 36 patients. CD63 expression was significantly higher in patients with high-grade PCa compared to those with low-grade PCa. CD9 expression was significantly downregulated in PCa patients compared to the control group. MMR protein expression deficiency was observed in 10 PCa patients. MMR proteins were maintained in all cases of BPH. The study found a negative correlation between MMR protein loss and PCa ISUP grade groups. Progression-free survival (PFS) in patients with MMR deficiency was significantly shorter than in patients with maintained MMR expression. Conclusions. CD9 protein expression was downregulated in PCa, compared to BPH, while CD63 protein expression was upregulated in high-grade PCa but downregulated in low-grade PCa. CD63 protein upregulation, CD9 downregulation, and loss of MMR protein characterized the shorter PFS of high-grade PCa patients. CD9, CD63, and MMR could be the routine immunohistochemical biomarkers for the diagnosis and risk stratification of PCa.
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- 2022
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41. First-principles and semi-empirical calculations for bound hole polarons in KNbO3
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Kotomin, E. A., Eglitis, R. I., Postnikov, A. V., Borstel, G., and Christensen, N. E.
- Subjects
Condensed Matter - Materials Science - Abstract
The ab initio linear muffin-tin-orbital (LMTO) formalism and the semi-empirical method of the Intermediate Neglect of the Differential Overlap (INDO) based on the Hartree-Fock formalism are combined for the study of the hole polarons (a hole trapped nearby the cation vacancy) in a cubic phase of KNbO3 perovskite crystals. The 40-atom and 320-atom supercells were used, respectively. We predict existence of both, one-site and two-site (molecular) polarons with close optical absorption energies (0.9 eV and 0.95 eV). The relevant experimental data are discussed., Comment: 4 pages with 4 embedded postscript figures; to be published in Phys. Rev. B
- Published
- 1999
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42. DISTRIBUTION OF CARBON STARS IN THE GALAXY
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I. Eglitis and A. Sokolova
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circumstellar mater ,near infrared ,carbon stars ,absolute magnitude ,distance ,Astronomy ,QB1-991 - Abstract
A search for new faint carbon (C) stars in the Polar region δ > 55o has been accomplished by obtaining objective prism spectra in the near infrared 550 -- 900 nm on images of CCD camera of Baldone Schmidt telescope of Astrophysical observatory. The positions of stars having color indices (J – K) > 1.3 mag in Two Micron All Sky Infrared Survey (2MASS) were selected to pick out suspicious carbon stars. Our survey is limited in brightness by J < 10 mag. 24 new carbon stars were found and their characteristics obtained. The correlative relation between Teff and spectral gradient [757 – 685] was confirmed. Such characteristics as Teff, distance from the Sun, absolute Mk were obtained for newly discovered carbon stars.
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- 2018
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43. ASTEROIDS EXPLORATION WITH BALDONE SCHMIDT TELE-SCOPE
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I. Eglitis
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астероїди ,камера шмідта ,архів фотоплатівок ,Astronomy ,QB1-991 - Abstract
CCD observations of asteroids were ob-tained in 2008 with the Baldone Schmidt telescope (aper-ture/diameter/focal length = 80/120/240 cm) at the Bal-done Astrophysical observatory (code 069) of the Institute of Astronomy of the University of Latvia. The methodology of monitoring of asteroids and orbit calculations are described. In the Minor Planet Circulars and the Minor Planet Electronic Circulars 5434 astrometric positions of 1488 asteroids were published. Among them, 76 asteroids of different type were newly discovered at Baldone Observatory. Twelve asteroids were named. Baldone Schmidt telescope optical system was im-proved by inserting an additional optical system in the telescope, forming a flat telescope focal surface that coin-cides with the surface of the flat beam receiver. Two large (4096 x 4096 pixels) CCD cameras are now installed on the plate holder of the telescope. They cover two square degrees of the sky. The digitizing of the Baldone Schmidt archive began in 2012. The processing results of 152 plates obtained in U, B, V, R bands in 1967-1996 were used to search for imag-es of small bodies of the Solar system. Images were pro-cessed using advanced complex LINUX / MIDAS / RO-MAPHOT programs updated in the Main Observatory of National Academy of Sciences of Ukraine. 57 asteroids and 2 comets (31P/Schwassmann-Wachmann 2, C/1969 T1 (Tago-Sato-Kosaka)) were identified on these plates. Overall 87 positions of asteroids of different types and 2 positions of comets were measured. These objects cover magnitude range from 9.8 to 17.1.
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- 2018
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44. Systematic trends in (001) surface ab initio calculations of ABO3 perovskites
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R.I. Eglitis and A.I. Popov
- Subjects
Chemistry ,QD1-999 - Abstract
By means of the hybrid exchange–correlation functionals, as it is implemented in the CRYSTAL computer code, ab initio calculations for main ABO3 perovskite (001) surfaces, namely SrTiO3, BaTiO3, PbTiO3, CaTiO3, SrZrO3, BaZrO3, PbZrO3 and CaZrO3, were performed. For ABO3 perovskite (001) surfaces, with a few exceptions, all atoms of the upper surface layer relax inward, all atoms of the second surface layer relax outward, and all third layer atoms, again, inward. The relaxation of (001) surface metal atoms for ABO3 perovskite upper two surface layers for both AO and BO2-terminations, in most cases, are considerably larger than that of oxygen atoms, what leads to a considerable rumpling of the outermost plane. The ABO3 perovskite (001) surface energies always are smaller than the (011) and especially (111) surface energies. The ABO3 perovskite AO and BO2-terminated (001) surface band gaps always are reduced with respect to the bulk values. The B–O chemical bond population in ABO3 perovskite bulk always are smaller than near the (001) and especially (011) surfaces. Keywords: Ab initio calculations, B3PW, B3LYP, ABO3 perovskites, (001) surfaces
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- 2018
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45. ASTEROID SEARCH RESULTS FOR DIGITIZED ASTROPLATES OF 1.2m TELESCOPE IN BALDONE
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I. Eglitis, O. Yizhakevych, S. Shatokhina, Yu. Protsyuk, and V. Andruk
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Astronomy ,QB1-991 - Abstract
The work on the mass search for asteroids on astroplate images and the determination of their coordi- nates was begun in 2016. The basis for current search was the processing results of digitized photographic plates and films obtained at the observatory in Baldone in 1967-1993. Observations with a single exposure in different spectral bands were carried out using the 1.2m Schmidt telescope in Baldone. We used all observations in the U Johnson's spec- tral band (on plates) and significant part of them in V band (on films). Photometric band U was realized by combining emulsion ORWO Zu1 (Zu2 or Zu21 or Kodak 103aO or IIaO) with UG1 filter. For films with A600 emulsion and filter ZS17 a photometric band V was implemented. Based on the results of digital processing about 300 U- plates and more than 1460 V-films, a preliminary catalog of 1700 asteroid positions was compiled. Among the ob- jects in this catalog are asteroids of particular interest. These include the distant objects (136108) Haumea and (136472) Makemake and some Main belt asteroids, the positions of which were fixed on the plates many years before their own discoveries. All observed positions of asteroids were compared with ephemeris DE431. An analysis of the convergence of the observed positions with their theoretical data for different spectral bands showed that the observations on V-films are better consistent with theory. However, the internal accuracy of determining coordi- nates from U-plates, on the contrary, is higher than from V-films. This discrepancy is especially noticeable for right ascension, when the root-mean-square errors on V-films can reach values exceeding 1.8 arc seconds. These signifi- cant errors are a consequence of the curvature unevenness of the film surface during scanning
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- 2019
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46. NEW ASTROMETRIC REDUCTION OF THE SUPERCOSMOS PLATE ARCHIVE: FIRST RESULTS
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V. S. Akhmetov, V. M. Andruk, Yu. I. Protsyuk, H. Relke, and I. Eglitis
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Astronomy ,QB1-991 - Abstract
The arrivals of the new more accuracy reference catalogues and also development of new meth- ods and approaches for reduction astrometric data give the new life for photographic plates archives. Gaia DR2 is not only a giant step in the astrometric accuracy allowing to measure new objects also provides plates archives ob- served in the past with modern accuracy. In this work we present the first results of astrometric reduction in the sys- tem of Gaia DR2 for some photographic plates that were obtained by UK Schmidt telescope (UKST) and digitized by the SuperCOSMOS scanning machine. The UKST is a classical Schmidt with the following parameters: mirror diameter 1.83m; focal length 3.07m; photographic plate size 356mm square, covering 6.4 x 6.4 degrees of sky; plate scale 67.12 arcsec/mm. To date the UKST has taken over 17,000 plates, the plates are stored in the Plate Li- brary at the Royal Observatory, Edinburgh. The photo- graphic plates are digitized to 15 bits (32768 grey levels) with a resolution of 10 microns (0.67 arcsec)/pixel). Each digitized Schmidt plate has size 32256x32256 pixels and produces about 2 Gbyte pixel data .. We are making new reduction of photographic plates that allowing to provide valuable data for future researches in astrometry as well as in astrophysics. The obtained astrometric and photometric data from photographic plates were compared with same one from modern catalogues.
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- 2019
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47. Computer simulations of defects in perovskite KNbO3 crystals
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Eglitis, R. I., Kotomin, E. A., Postnikov, A. V., Christensen, N. E., Korotin, M. A., and Borstel, G.
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Condensed Matter - Materials Science - Abstract
An ab initio LMTO approach and semi-empirical quantum chemical INDO method have been used for supercell calculations of basic point defects - F-type centers and hole polarons bound to cation vacancy - in partly covalent perovskite KNbO3. We predict the existence of both one-site and two-site (molecular) polarons with close absorption energies (~ 1 eV). The relevant experimental data are discussed and interpreted., Comment: 7 pages with 1 embedded postscript figure; submitted to the proceedings of the 2nd Asian Meeting on Ferroelectrics
- Published
- 1998
48. First-principles and semiempirical Hartree-Fock calculations for F centers in KNbO3 and Li impurities in KTaO3
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Eglitis, R. I., Kotomin, E. A., Postnikov, A. V., Christensen, N. E., and Borstel, G.
- Subjects
Condensed Matter - Materials Science - Abstract
The LMTO method based on the density-functional theory and the semi-empirical INDO method based on the Hartree--Fock formalism are used for the supercell study of the F centers in cubic and orthorhombic ferroelectric KNbO3 crystals. Two electrons are found to be considerably delocalized even in the ground state of the defect. The absorption energies were calculated by means of the INDO method using the Delta-SCF scheme after a relaxation of atoms surrounding the F center. As an example of another type of point defect in perovskite, an isolated Li impurity in KTaO3 as well as interacting Li pairs are considered in the supercell approach, using the supercells of up to 270 atoms. The off-center Li displacement, reorientational energy barriers and the lattice relaxation around impurities are calculated. The results are compared with those obtained earlier within the shell model, revealing the relaxation pattern somehow different from the shell model estimations., Comment: 10 pages, 4 figures, uses aipproc.sty. Presented at the Fifth Williamsburg Workshop on First-Principles Calculations for Ferroelectrics
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- 1998
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49. First-principles and semiempirical calculations for F centers in KNbO3
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Eglitis, R. I., Christensen, N. E., Kotomin, E. A., Postnikov, A. V., and Borstel, G.
- Subjects
Condensed Matter - Materials Science - Abstract
The linear muffin-tin-orbital method combined with density functional theory (local approximation) and the semiempirical method of the intermediate neglect of the differential overlap (INDO) based on the Hartree-Fock formalism are used for the study of the $F$ centers (O vacancy with two electrons) in cubic and orthorhombic ferroelectric KNbO$_3$ crystals. Calculations for 39-atom supercells show that the two electrons are considerably delocalized even in the ground state of the defect. Their wave functions extend over the two Nb atoms closest to the O vacancy and over other nearby atoms. Thus, the $F$ center in KNbO$_3$ resembles electron defects in the partially-covalent SiO$_2$ crystal (the so-called $E^{\prime}_1$ center) rather than usual $F$ centers in ionic crystals like MgO and alkali halides. This covalency is confirmed by the analysis of the electronic density distribution. Absorption energies were calculated by means of the INDO method using the $\Delta$ self-consistent-field scheme after a relaxation of atoms surrounding the $F$ center. For the orthorhombic phase three absorption bands are calculated to lie at 2.72 eV, 3.04 eV, and 3.11 eV. The first one is close to that observed under electron irradiation. For the cubic phase, stable at high temperatures, above 708 K, only the two bands, at 2.73 eV and 2.97 eV, are expected., Comment: 7 pages, including 4 postscript figures; with minor changes, as will appear in Phys. Rev. B
- Published
- 1997
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50. Semiempirical Hartree-Fock calculations for pure and Li-doped KTaO3
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Eglitis, R. I., Postnikov, A. V., and Borstel, G.
- Subjects
Condensed Matter - Materials Science - Abstract
In extension of our previous study of KNbO_3 by the semiempirical Hartree-Fock method we present parameterization and total-energy results for non-ferroelectric KTaO_3 as a pure crystal (concentrating on the frozen phonon calculations) and that with Li impurities. The magnitudes of off-center Li displacements and the relaxation energies related to re-orientation of Li are calculated and compared with experimental estimates and earlier calculation results. The spatial extent of lattice relaxation around Li impurities and contributions from different neighbors to the relaxation energy are discussed., Comment: 7 pages, 3 postscript figures embedded using epsf macro to be published in Phys.Rev.B
- Published
- 1997
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