Analysis of own experience of studying at the university

Проведено критичний аналіз власного досвіду навчання за п’ять курсів  та зроблено пропозиції щодо покращення навчального процесу. Critical analysis of own experience of studying for five courses was conducted and suggestions for improvement of the educational process were made

Estimation of NO2_{2} emission strengths over Riyadh and Madrid from space from a combination of wind-assigned anomalies and a machine learning technique

Nitrogen dioxide (NO$_{2}$) air pollution provides valuable information for quantifying NOx (NOx = NO +NO$_{2}$) emissions and exposures. This study presents a comprehensive method to estimate average tropospheric NO$_{2}$emission strengths derived from 4-year (May 2018–June 2022) TROPOspheric Monitoring Instrument (TROPOMI) observations by combining a wind-assigned anomaly approach and a machine learning (ML) method, the so-called gradient descent algorithm. This combined approach is firstly applied to the Saudi Arabian capital city of Riyadh, as a test site, and yields a total emission rate of 1.09×1026 molec. s−1. The ML-trained anomalies fit very well with the wind-assigned anomalies, with an R2 value of 1.0 and a slope of 0.99. Hotspots of NO2 emissions are apparent at several sites: over a cement plant and power plants as well as over areas along highways. Using the same approach, an emission rate of 1.99×1025 molec. s−1 is estimated in the Madrid metropolitan area, Spain. Both the estimate and spatial pattern are comparable with the Copernicus Atmosphere Monitoring Service (CAMS) inventory. Weekly variations in NO$_{2}$emission are highly related to anthropogenic activities, such as the transport sector. The NO$_{2}$emissions were reduced by 16 % at weekends in Riyadh, and high reductions were found near the city center and in areas along the highway. An average weekend reduction estimate of 28 % was found in Madrid. The regions with dominant sources are located in the east of Madrid, where residential areas and the Madrid-Barajas airport are located. Additionally, due to the COVID-19 lockdowns, the NO$_{2}$emissions decreased by 21 % in March–June 2020 in Riyadh compared with the same period in 2019. A much higher reduction (62 %) is estimated for Madrid, where a very strict lockdown policy was implemented. The high emission strengths during lockdown only persist in the residential areas, and they cover smaller areas on weekdays compared with weekends. The spatial patterns of NO$_{2}$emission strengths during lockdown are similar to those observed at weekends in both cities. Although our analysis is limited to two cities as test examples, the method has proven to provide reliable and consistent results. It is expected to be suitable for other trace gases and other target regions. However, it might become challenging in some areas with complicated emission sources and topography, and specific NO$_{2}$decay times in different regions and seasons should be taken into account. These impacting factors should be considered in the future model to further reduce the uncertainty budget

Estimation of NO2 emission strengths over Riyadh and Madrid from space from a combination of wind-assigned anomalies and machine learning technique

Nitrogen dioxide (NO2) air pollution provides valuable information for quantifying NOx emissions and exposures. This study presents a comprehensive method to estimate average tropospheric NO2 emission strengths derived from three-year (April 2018 – March 2021) TROPOMI observations by combining a wind-assigned anomaly approach and a Machine Learning (ML) method, the so-called Gradient Descent. This combined approach is firstly applied to the Saudi Arabian capital city Riyadh, as a test site, and yields a total emission rate of 1.04×1026 molec./s. The ML-trained anomalies fit very well with the wind-assigned anomalies with an R2 value of 1.0 and a slope of 0.99. Hotspots of NO2 emissions are apparent at several sites where the cement plant and power plants are located and over areas along the highways. Using the same approach, an emission rate of 1.80×1025 molec./s is estimated in the Madrid metropolitan area, Spain. Both the estimate and spatial pattern are comparable to the CAMS inventory.We also acknowledge the project of Joint R&D and Talents Program funded by the Qingdao Sino-German Institute of Intelligent Technologies (kh0100020213319) and the project of Transnational Interoperability Rules and Solution Patterns in Collaborative Production Networks based on IDS and GAIA-X funded by Ministry of Science and Technology, PRC (SQ2021YFE010470)

Estimation of NO2 emission strengths over Riyadh and Madrid from space from a combination of wind-assigned anomalies and a machine learning technique

Nitrogen dioxide (NO2) air pollution provides valuable information for quantifying NOx (NOx = NO + NO2) emissions and exposures. This study presents a comprehensive method to estimate average tropospheric NO2 emission strengths derived from 4-year (May 2018–June 2022) TROPOspheric Monitoring Instrument (TROPOMI) observations by combining a wind-assigned anomaly approach and a machine learning (ML) method, the so-called gradient descent algorithm. This combined approach is firstly applied to the Saudi Arabian capital city of Riyadh, as a test site, and yields a total emission rate of 1.09×1026 molec. s−1. The ML-trained anomalies fit very well with the wind-assigned anomalies, with an R2 value of 1.0 and a slope of 0.99. Hotspots of NO2 emissions are apparent at several sites: over a cement plant and power plants as well as over areas along highways. Using the same approach, an emission rate of 1.99×1025 molec. s−1 is estimated in the Madrid metropolitan area, Spain. Both the estimate and spatial pattern are comparable with the Copernicus Atmosphere Monitoring Service (CAMS) inventory.We wish to acknowledge the Joint R&D and Talents Program project, funded by the Qingdao Sino-German Institute of Intelligent Technologies (grant no. kh0100020213319); the Deutsche Forschungsgemeinschaft; and the Open Access Publishing Fund of the Karlsruhe Institute of Technology for their support

Iron induces two distinct Ca²⁺ signalling cascades in astrocytes.

From Europe PMC via Jisc Publications RouterHistory: ppub 2021-05-01, epub 2021-05-05Publication status: PublishedFunder: National Natural Science Foundation of China (National Science Foundation of China); Grant(s): 81871852Iron is the fundamental element for numerous physiological functions. Plasmalemmal divalent metal ion transporter 1 (DMT1) is responsible for cellular uptake of ferrous (Fe2+), whereas transferrin receptors (TFR) carry transferrin (TF)-bound ferric (Fe3+). In this study we performed detailed analysis of the action of Fe ions on cytoplasmic free calcium ion concentration ([Ca2+]i) in astrocytes. Administration of Fe2+ or Fe3+ in μM concentrations evoked [Ca2+]i in astrocytes in vitro and in vivo. Iron ions trigger increase in [Ca2+]i through two distinct molecular cascades. Uptake of Fe2+ by DMT1 inhibits astroglial Na+-K+-ATPase, which leads to elevation in cytoplasmic Na+ concentration, thus reversing Na+/Ca2+ exchanger and thereby generating Ca2+ influx. Uptake of Fe3+ by TF-TFR stimulates phospholipase C to produce inositol 1,4,5-trisphosphate (InsP3), thus triggering InsP3 receptor-mediated Ca2+ release from endoplasmic reticulum. In summary, these findings reveal the mechanisms of iron-induced astrocytic signalling operational in conditions of iron overload

Polymorphisms of Glutathione S-transferases Omega-1 among ethnic populations in China

<p>Abstract</p> <p>Background</p> <p>Glutathione S-transferases (GSTs) is a genetic factor for many diseases and exhibits great diversities among various populations. We assessed association of the genotypes of Glutathione S-transferases Omega-1 (GSTO1) A140D with ethnicity in China.</p> <p>Results</p> <p>Peripheral blood samples were obtained from 1314 individuals from 14 ethnic groups. Polymorphisms of GSTO1 A140D were measured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Logistic regression was employed to adjustment for regional factor. The frequency of GSTO1 140A allele was 15.49% in the total 14 ethnic populations. Compared to Han ethnic group, two ethnic populations were more likely to have AA or CA genotype [odds ratio (OR): 1.77, 95% confidence interval (95% CI): 1.05–2.98 for Uygur and OR: 1.78, 95% CI: 1.18–2.69 for Hui]. However, there were no statistically significant differences across 14 ethnic groups when region factor was adjusted. In Han ethnicity, region was significantly associated with AA or CA genotype. Han individuals who resided in North-west of China were more likely to have these genotypes than those in South of China (OR: 1.63, 95% CI: 1.21–2.20).</p> <p>Conclusion</p> <p>The prevalence of the GSTO1 140A varied significantly among different regional populations in China, which showed that geography played a more important role in the population differentiation for this allele than the ethnicity/race.</p

Failure to experimentally infect 10 days-old piglets with a cell culture-propagated infectious stock of a classical genotype 1a porcine epidemic diarrhea virus

Introduction: Porcine epidemic diarrhea virus (PEDV) causes enteric disease in pigs of all ages. PEDV can be grouped into G1 (classical strains) and G2 (variant strains) based on sequence differences in the spike gene. Although several pathogenesis studies using contemporary strains of PEDV have been conducted to date, there is limited information on the pathogenesis of historical PEDV strains in contemporary pigs. This study aimed to investigate the clinical disease course of 10 days-old pigs infected with a classical European G1a PEDV strain from the 1980s which was last passaged in pigs in 1994. Methods: Sequencing results confirmed that the virus inoculum was a PEDV strain closely related to the prototype CV777 strain. The PEDV stock was serially passaged three times in Vero cells, and the P3 infectious virus stock was used to inoculate the pigs. A total of 40 pigs were inoculated using the oral route. Results: Pigs showed no enteric disease signs, and PEDV shedding was not detected for 44 days post-inoculation (dpi). At necropsy at 3 (5 pigs) or 7 dpi (5 pigs), no lesions were observed in intestinal sections, which were negative for PEDV antigen by immunohistochemistry. In addition, no IgG or IgA PEDV-specific antibodies in serum or fecal samples for 35 dpi further indicates a lack of infection. Titration of the leftover thawed and refrozen PEDV virus stock inoculum showed that the virus stock retained its infectivity in Vero cell culture and the porcine small intestine enterocytes cell line IPEC-J2. Discussion: The reasons for the loss of infectivity in pigs are unknown. In conclusion, we showed that a classical G1a PEDV strain successfully propagated in cell cultures could not orally infect 40 piglets

B7-H4 gene polymorphisms are associated with sporadic breast cancer in a Chinese Han population

© 2009 Zhang et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Association of CD40 Gene Polymorphisms with Sporadic Breast Cancer in Chinese Han Women of Northeast China

BACKGROUND: Breast cancer is a polygenetic disorder with a complex inheritance pattern. Single nucleotide polymorphisms (SNPs), the most common genetic variations, influence not only phenotypic traits, but also interindividual predisposition to disease, treatment outcomes with drugs and disease prognosis. The co-stimulatory molecule CD40 plays a prominent role in immune regulation and homeostasis. Accumulating evidence suggests that CD40 contributes to the pathogenesis of cancer. Here, we set out to test the association between polymorphisms in the CD40 gene and breast carcinogenesis and tumor pathology. METHODOLOGY AND PRINCIPAL FINDINGS: Four SNPs (rs1800686, rs1883832, rs4810485 and rs3765459) were genotyped by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method in a case-control study including 591 breast cancer patients and 600 age-matched healthy controls. Differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed by the Chi-square test for trends. Our preliminary data showed a statistically significant association between the four CD40 gene SNPs and sporadic breast cancer risk (additive P = 0.0223, 0.0012, 0.0013 and 0.0279, respectively). A strong association was also found using the dominant, recessive and homozygote comparison genetic models. In the clinical features analysis, significant associations were observed between CD40 SNPs and lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2), estrogen receptor (ER), progesterone receptor (PR) and tumor protein 53 (P53) statuses. In addition, our haplotype analysis indicated that the haplotype C(rs1883832)G(rs4810485), which was located within the only linkage disequilibrium (LD) block identified, was a protective haplotype for breast cancer, whereas T(rs1883832)T(rs4810485) increased the risk in the studied population, even after correcting the P value for multiple testing (P = 0.0337 and 0.0430, respectively). CONCLUSIONS AND SIGNIFICANCE: Our findings primarily show that CD40 gene polymorphisms contribute to sporadic breast cancer risk and have a significant association with clinicopathological features among Chinese Han women from the Heilongjiang Province