The state of the respiratory system of students in conditions of high-altitude hypoxia

The article presents the results of studies on the influence of mountain hypoxia on the state of the students’ respiratory system. When exposed to oxygen deficiency, only the respiratory capacity of the lungs undergoes significant changes. For instance, the RC level in female students under the influence of hypoxia gradually increased in conditions of medium altitude, reaching the maximum value of 0.64 liters (P ˂ 0.05), and on the plain - 0.44 liters. The RC value in young men reached the highest value of 0.74 liters in mid-altitude conditions, and on the plains, it constitutes 0.56 liters. The highest respiration rate for young men of 18.2 movements per minute was noted at an altitude of 600 meters, and the lowest - 17.4 at an altitude of 170 m. The maximum level of respiratory capacity while inhaling in girls is 1.24 liters, detected at an altitude of 600 meters, and the minimum level of 1.18 liters is noted at 170 m. The value of respiratory capacity while exhaling among young men living in the Sharoi region increased to 2.32 liters, and for those from Grozny - 2.24 liters. The highest VC level in girls - 3.87 liters - was found in the middle mountains, and on the plains, it was 3.58 liters. The VC value in young men, gradually increasing, reaches the highest value under the conditions of the Sharoi region - 4.57 liters, and in Grozny it was 4.28.

An Assessment of Urban Expansion Impacts on Land Transformation of Rajpur-Sonarpur Municipality

Urban expansion, population pressure, and increasing industrialization are influenced the world's natural environment, increased climate change, and global warming. Land use and land cover (LULC) changes are occurring due to anthropogenic activities and the results are land transformation, thermal variation, heat stress, and massive vegetation loss, which is increased oxygen deficiency and air pollution. Remote sensing-based Landsat TM and OLI/TIRS data were used to identify the land transformation and the effect of urbanization in Rajpur-Sonarpur Municipality in the years 2000 and 2020. The Built-up land was increased due to anthropogenic activities and around 12.16% area has been increased. Similarly, the agricultural land has been increased by 2.10 km2 area and vegetation area has been decreased around 6.52 km2 in the study area. The vegetation degradation areas were located in the South, South-west, and central parts of this study area. Correspondingly, North, North-west and central parts have a noticeable amount of built-up area developed. During twenty years, 6.97°C temperature was increased due to urban expansion, population pressure, transportation accessibility, and other urban amenities. The overall accuracies of classification maps were 96.25% and 91.64 % and the kappa coefficients were 0.95 and 0.89 respectively.

The Participation of the Organism Adaptation Mechanisms to the Lack of Oxygen According to the Assessment of the Fethemoglobin Content in the Peripheral Blood of Patients with Community-acquired Pneumonia

Introduction. Сommunity-acquired pneumonia (COP) is a global socio-medical problem. At emergence of pneumonia by any genesis, hypoxia develops. Oxygen homeostasis of the body is provided by the coordinated interaction of external respiration, circulatory system and oxygen-transport system of the blood. Hypoxia, due to the malfunction of the external respiratory system, causes the formation of compensatory changes, in the implementation of which involved components of the oxygen transport system. Molecular genetic mechanisms play an important role in the body's adaptation to oxygen deficiency. Fetal hemoglobin (FetHb), having an increased affinity for oxygen, makes a significant contribution to the body's adaptation to new conditions with altered gaseous environment in the presence of pathological processes occurring with hypoxia. In this regard, it is interest to determine FetHb in adults with COP to study its effect on the diagnosis, prognosis and outcome of the disease. The aim of the study. To determinate the participation of the organism adaptation mechanisms to the lack of oxygen according to the assessment of the content of fetal hemoglobin in the peripheral blood of patients with community-acquired pneumonia. Materials and methods. We examined 34 adult patients (18 women and 16 men) with COP, aged 18 to 80 years, who were in the therapeutic department of the City Clinical Hospital № 25 in Kharkiv. The control group was formed of 20 healthy individuals. Spirography was performed on the diagnostic complex "Valenta"; hematological examinations – on the analyzer "ADVIA 60"; measurement of pO2 and pCO2, oxygen saturation, content of fetal hemoglobin – on the device "RAPIDLAB865". Results. In patients with community-acquired pneumonia, there was a decrease of the ventilatory function of external respiration, which is confirmed by a marked decrease in partial oxygen pressure. Oxygen saturation of blood was reduced in the group of patients with COP, but the difference was not statistically significant 94.8 ± 1.0 %. This indicates the presence of compensatory mechanisms aimed at maintaining adequate blood oxygen saturation. Significant increase in pH (from 7.40 to 7.53) and decrease in standard bicarbonate (from 1.27 to 0.68 mmol/l) resulting from violation of the gas composition of the blood can be regarded as a manifestation of partially compensated respiratory alkalosis. In patients with COP, there was a reduction in the total time of hemolysis, a shift of the maximum erythrogram to the left and an increase in the maximum itself, indicating a sharp decline in erythrocyte resistance. The proportion of erythrocytes with reduced resistance was twice as large as similar forms in the control group and the number of highly resistant cells in patients with COP sharply decreased. Obviously, oxygen starvation-mediated stress erythropoiesis is accompanied by the entry into the circulation of functionally defective erythrocytes. They are subject to accelerated elimination from the vascular bed, which causes a decrease in the quantitative indicators of red blood (erythrocyte content, hemoglobin) while maintaining corpuscular parameters (Mean Corpuscular Volume, Mean Cell Hemoglobin Concentration). At the same time, the analysis of individual hemoglobin fractions revealed an increase in the proportion of fetal hemoglobin (from 2.90 ± 0.31 % in the group of healthy individuals to 5.43 ± 1.05 % in patients with COP) (p less than 0.05). Conclusions. Changes in the parameters of acid hemolysis, fetal hemoglobin in the peripheral blood of patients with community-acquired pneumonia with impaired pulmonary ventilation function indicate their participation in the mechanisms of adaptation to oxygen deficiency and they have informative potential. Elevated fetal hemoglobin in peripheral blood in these patients can be used as an indicator of hypoxia, accompanied by impaired oxygen delivery to tissues, which should be used as an additional criterion for diagnosing tissue hypoxia and justify the timely appointment of antihypoxia drugs. Keywords: hypoxia, community-acquired pneumonia, red blood cells, fetal hemoglobin.

New In-Flame Flammability Testing Method Applied to Monitor Seasonal Changes in Live Fuel

Improving the accuracy of fire behavior prediction requires better understanding of live fuel, the dominant component of tree crowns, which dictates the consumption and energy release of the crown fire flame-front. Live fuel flammability is not well represented by existing evaluation methods. High-flammability live fuel, e.g., in conifers, may maintain or increase the energy release of the advancing crown fire flame-front, while low-flammability live fuel, e.g., in boreal deciduous stands, may reduce or eventually suppress flame-front energy release. To better characterize these fuel–flame-front interactions, we propose a method for quantifying flammability as the fuel’s net effect on (contribution to) the frontal flame energy release, in which the frontal flame is simulated using a methane diffusion flame. The fuel’s energy release contribution to the methane flame was measured using oxygen consumption calorimetry as the difference in energy release between the methane flame interacting with live fuel and the methane flame alone. In-flame testing resulted in fuel ignition and consumption comparable to those in wildfires. The energy release contribution of live fuel was significantly lower than its energy content measured using standard methods, suggesting better sensitivity of the proposed metric to water content- and oxygen deficiency-associated energy release reductions within the combustion zone.

Transient Focal Cerebral Ischemia Leads to miRNA Alterations in Different Brain Regions, Blood Serum, Liver, and Spleen

Ischemic stroke is characterized by an occlusion of a cerebral blood vessel resulting in neuronal cell death due to nutritional and oxygen deficiency. Additionally, post-ischemic cell death is augmented after reperfusion. These events are paralleled by dysregulated miRNA expression profiles in the peri-infarct area. Understanding the underlying molecular mechanism in the peri-infarct region is crucial for developing promising therapeutics. Utilizing a tMCAo (transient Middle Cerebral Artery occlusion) model in rats, we studied the expression levels of the miRNAs (miR) 223-3p, 155-5p, 3473, and 448-5p in the cortex, amygdala, thalamus, and hippocampus of both the ipsi- and contralateral hemispheres. Additionally, the levels in the blood serum, spleen, and liver and the expression of their target genes, namely, Nlrp3, Socs1, Socs3, and Vegfa, were assessed. We observed an increase in all miRNAs on the ipsilateral side of the cerebral cortex in a time-dependent manner and increased miRNAs levels (miR-223-3p, miR-3473, and miR-448-5p) in the contralateral hemisphere after 72 h. Besides the cerebral cortex, the amygdala presented increased expression levels, whereas the thalamus and hippocampus showed no alterations. Different levels of the investigated miRNAs were detected in blood serum, liver, and spleen. The gene targets were altered not only in the peri-infarct area of the cortex but selectively increased in the investigated non-affected brain regions along with the spleen and liver during the reperfusion time up to 72 h. Our results suggest a supra-regional influence of miRNAs following ischemic stroke, which should be studied to further identify whether miRNAs are transported or locally upregulated.

Influence of manure application method on gray forest soil fertility, crop yield and quality

The article presents the results of field experiments on deepening the arable horizon of gray forest medium loamy soil to increase its fertility through applying organic fertilizer under PY-3-35 layer plow to a depth of 2527 cm. Low mineralization of organic fertilizer during layer cultivation under oxygen deficiency conditions contributed to accumulation of humus in soil by 6.6 t/ha more than during conventional plowing, and by 7.5 t/ha - than during disking. It also improved water-physical and biological properties of soil: number of water-resistant aggregates increased by 4.6 and 5.3 %, soil density lowered by 0.03 and 0.04 g/cm3, number of earthworms increased by 3...6 individuals, expanded reproduction of fertility was provided, productivity of arable land increased by 7.0 and 6.7 % and crop quality increased compared to conventional plowing and disking, respectively. Deep manure incorporation extended life of organic fertilizer up to 5 years, while after conventional plowing and disking this process lasted only 2...3 years. It is not economically and environmentally beneficial, since frequent application requires a lot of fuel, and a large amount of harmful chemical compounds contained in combustion products is dumped into the environment.

Metabolic Changes in Seed Embryos of Hypoxia-Tolerant Rice and Hypoxia-Sensitive Barley at the Onset of Germination

Rice (Oryza sativa L.) and barley (Hordeum vulgare L.) are the cereal species differing in tolerance to oxygen deficiency. To understand metabolic differences determining the sensitivity to low oxygen, we germinated rice and barley seeds and studied changes in the levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), activities of the enzymes involved in their scavenging, and measured cell damage parameters. The results show that alcohol dehydrogenase activity was higher in rice than in barley embryos providing efficient anaerobic fermentation. Nitric oxide (NO) levels were also higher in rice embryos indicating higher NO turnover. Both fermentation and NO turnover can explain higher ATP/ADP ratio values in rice embryos as compared to barley. Rice embryos were characterized by higher activity of S-nitrosoglutathione reductase than in barley and a higher level of free thiols in proteins. The activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase) in imbibed embryos were higher in rice than in barley, which corresponded to the reduced levels of ROS, malonic dialdehyde and electrolyte leakage. The observed differences in metabolic changes in embryos of the two cereal species differing in tolerance to hypoxia can partly explain the adaptation of rice to low oxygen environments.