Effects Of Altitudes Research Articles

Comparison and Optimal Method of Detecting the Number of Maize Seedlings Based on Deep Learning

Effective agricultural management in maize production operations starts with the early quantification of seedlings. Accurately determining plant presence allows growers to optimize planting density, allocate resources, and detect potential growth issues early on. This study provides a comprehensive analysis of the performance of various object detection models in maize production, with a focus on the effects of planting density, growth stages, and flight altitudes. The findings of this study demonstrate that one-stage models, particularly YOLOv8n and YOLOv5n, demonstrated superior performance with AP50 scores of 0.976 and 0.951, respectively, outperforming two-stage models in terms of resource efficiency and seedling quantification accuracy. YOLOv8n, along with Deformable DETR, Faster R-CNN, and YOLOv3-tiny, were identified for further examination based on their performance metrics and architectural features. The study also highlights the significant impact of plant density and growth stage on detection accuracy. Increased planting density and advanced growth stages (particularly V6) were associated with decreased model accuracy due to increased leaf overlap and image complexity. The V2–V3 growth stages were identified as the optimal periods for detection. Additionally, flight altitude negatively affected image resolution and detection accuracy, with higher altitudes leading to poorer performance. In field applications, YOLOv8n proved highly effective, maintaining robust performance across different agricultural settings and consistently achieving rRMSEs below 1.64% in high-yield fields. The model also demonstrated high reliability, with Recall, Precision, and F1 scores exceeding 99.00%, affirming its suitability for practical agricultural use. These findings suggest that UAV-based image collection systems employing models like YOLOv8n can significantly enhance the accuracy and efficiency of seedling detection in maize production. The research elucidates the critical factors that impact the accuracy of deep learning detection models in the context of corn seedling detection and selects a model suited for this specific task in practical agricultural production. These findings offer valuable insights into the application of object detection technology and lay a foundation for the future development of precision agriculture, particularly in optimizing deep learning models for varying environmental conditions that affect corn seedling detection.

Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction

In high-altitude nuclear detonations, the proportion of pulsed X-ray energy can exceed 70%, making it a specific monitoring signal for such events. These pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric transmission. To quantitatively analyze the effects of different satellite detection altitudes, burst heights, and transmission angles on the physical processes of X-ray transport and energy fluence, we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction. The proposed method is an improvement over the traditional analytical method that only computes direct-transmission X-rays. The traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo method. Our improved method reduces this error to within 10% under the same conditions, even reaching 1% in certain scenarios. Moreover, its computation time is 48,000 times faster than that of the Monte Carlo method. These results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors, inverting nuclear detonation source terms, and assessing ionospheric effects.

The HIF-1α/EGF/EGFR Signaling Pathway Facilitates the Proliferation of Yak Alveolar Type II Epithelial Cells in Hypoxic Conditions.

The yak is a unique creature that thrives in low-oxygen environments, showcasing its adaptability to high-altitude settings with limited oxygen availability due to its unique respiratory system. However, the impact of hypoxia on alveolar type II (AT2) epithelial cell proliferation in yaks remains unexplored. In this study, we investigated the effects of different altitudes on 6-month-old yaks and found an increase in alveolar septa thickness and AT2 cell count in a high-altitude environment characterized by hypoxia. This was accompanied by elevated levels of hypoxia-inducible factor-1α (HIF-1α) and epidermal growth factor receptor (EGFR) expression. Additionally, we observed a significant rise in Ki67-positive cells and apoptotic lung epithelial cells among yaks inhabiting higher altitudes. Our in vitro experiments demonstrated that exposure to hypoxia activated HIF-1α, EGF, and EGFR expression leading to increased proliferation rates among yak AT2 cells. Under normal oxygen conditions, activation of HIF-1α enhanced EGF/EGFR expressions which subsequently stimulated AT2 cell proliferation. Furthermore, activation of EGFR expression under normoxic conditions further promoted AT2 cell proliferation while simultaneously suppressing apoptosis. Conversely, inhibition of EGFR expression under hypoxic conditions had contrasting effects. In summary, hypoxia triggers the proliferation of yak AT2 cells via activation facilitated by the HIF-1α/EGF/EGFR signaling cascade.

Effects of Different Altitudes on Castanopsis hystrix, the Top Community-Building Species in Southern Subtropical China: Rhizospheric Soil Chemical Properties and Soil Microbiota

Castanopsis hystrix, a dominant canopy species in the subtropical forests of south China, is renowned for its high natural regeneration ability. Therefore, this paper took C. hystrix as the subject of study. Examining the variations in microbial diversity and community composition within the soil rhizosphere of C. hystrix across different elevation gradients, we explored how this community-forming species impacts soil microbial diversity and community structure and how soil microorganisms respond to changes in soil physicochemical properties due to altitude gradients. The results show: (1) soil samples from five altitudes established 1078 fungal OTU and 5595 bacterial OTUs. (2) Basidiomycota and ascomycota are dominant fungal groups in the soil, with Acidobacteria being the predominant bacteria for C. hystrix. (3) As altitude increases, fungal communities’ richness and diversity index peaks at 849 m; for bacterial communities, the richness index peaks at 387 m and the diversity index at 670 m. (4) Total phosphorus (TP), nitrate nitrogen (NO3−-N), hydrolyzed nitrogen (HN), total nitrogen (TN), and organic matter (SOM) are significant environmental factors affecting fungal community structure. At the same time, available potassium (AK) significantly influences the composition of bacterial communities. The study underscores the intricate relationship between altitude, soil properties, and microbial diversity, offering insights into how C. hystrix contributes to ecosystem resilience. Recommendations include enhancing phosphorus supplementation and controlling nitrogen deposition to maintain forest ecological integrity, additionally, the supply of potassium in the soil should also be a key consideration. Further research is necessary to understand the broader implications for biodiversity conservation and adaptive management strategies in the face of climate change.

A matching method for Twin-VGT systems under varying expansion ratios at high altitudes

In this study, we established a matching method for a twin variable geometry turbocharging (Twin-VGT) system under varying expansion ratios at high altitudes. In addition, we developed an equivalent thermodynamic model of a two-stage variable turbine with the effective flow areas of turbines obtained under velocity constraints for altitudes ranging from 0 to 5500 m. The effects of altitudes on the matching efficacy of a two-stage compressor under different operating conditions were evaluated. Additionally, an optimal distribution of the total boost pressure was determined to minimize the output power of the two-stage compressor during non-isothermal compression at various altitudes. Furthermore, the interplay between exhaust available energy (EAE), total expansion ratio (TER), exhaust temperature, and turbine power was investigated. Lastly, the peak efficiency of the turbocharging system was evaluated by analyzing the distribution of the TER and total enthalpy drop, aimed at optimizing EAE at different altitudes.

Changes provoked by altitudes and cooking methods in physicochemical properties, volatile profile, and sensory characteristics of yak meat

The present study aimed to shed light on the effects of altitudes and three cooking methods (boiling, steaming, and roasting) on the physicochemical quality, volatile profile, and sensorial characteristics of yak meat. Composite meat samples were prepared to represent each cooking method and altitude level from the longissimus thoracis et lumborum (LTL) muscle of nine yaks. The techniques employed were gas chromatography-mass spectrometry (GC–MS) and electronic nose (E-nose) along with chemometrics analysis to study the changes occurring in yak volatile profile, and TBARS measurement in lipid oxidation during cooking. Among the cooking methods, boiling and steaming exhibited higher protein and fat content while lower volatile compound contents. Additionally, roasted yak meat received the highest sensory scores, along with decreased L*-values, while elevated a*- and b*-values, and tenderness. A total of 138 volatile compounds were detected, and among them, 36 odorants were identified as odor-active compounds in cooked yak meat. It is evidenced that low-altitude yak presented more complex and richer flavor profiles than high-altitude ones. Moreover, yak meat from low- and high-altitude was classified into two groups by an electronic nose (E-nose) owing to distinct flavor characteristics. Overall, roasted yak meat originating from low altitudes tends to be more popular from a sensory perspective.

Effects of altitudes on secondary metabolite contents of Origanum majorana L.

Altitude is an important ecological factor that significantly affects essential oil content, yield and composition. In this study, conducted to examine the effects of altitude on essential oil content and composition of O. majorana, plant samples were collected from the southern region of Türkiye at the beginning of flowering period from seven different altitudes (766 m, 890 m, 968 m, 1079 m, 1180 m, 1261 m and 1387 m) at 100 m intervals. The highest percentage of essential oil (6.50%) obtained by hydro-distillation was determined at 766 m altitudes. The GC–MS analyses revealed that low altitude affected some essential oil components positively. The linalool ratio, which is the major component of the essential oil of O. majorana species, was the highest at 766 m (79.84%) altitudes. Borneol, linalool oxide, trans-linalool oxide, caryophyllene, a-humulene, germacrene-D and bicyclogermacrene components yielded high values at 890 m altitudes. Thymol and α-terpineol, which have an important place in the essential oil composition, increased at 1180 m altitudes; a-terpinene, cis-sabinene hydrate, terpinene-4-ol and carvacrol increased at 1387 m altitudes.

Analytical Investigation of Surface Temperatures for Different Sized CubeSats at Varying Low Earth Orbits

Abstract Thermal management is a challenging engineering problem for CubeSats due to the limited available volumes restricting the thermal control applications. Therefore, performing thermal modeling and analyses of these small satellites is very crucial for applying proper thermal control measures to maintain safe operating conditions in space. Despite the growing interest in this field, there are still a limited number of studies investigating the thermal behavior of CubeSats. In this paper, surface temperature profiles of 1U, 2U, 3U, 5U, 6U, and 12U sized CubeSats are simulated for varying low earth orbits. The effects of altitudes changing from 400 km to 2000 km and the beta angles changing from 0 to 75 deg are analytically investigated. Not only the coatings with different absorptance and emissivity values but also different amounts of internal heat dissipations are examined to reveal their impact on the thermal balance of satellites. Results demonstrate surface temperatures are highly dependent on those variables. The amount of heat absorbed by satellite panels is affected by the different sizes of CubeSats, different coating properties of panels, and different orbital configurations. The outcomes of this research may be beneficial especially in the early design phase for designing small satellites and selecting proper orbital configurations.

Effects of different altitudes on the structure and properties of potato starch.

The main element influencing the quality of potato starch is the environment. To investigate the effects of different altitude cultivation locations on the molecular structure and physicochemical properties of starch, two potato varieties, Jiusen No.1 B1 and Qingshu No.9 B2, were planted in three different altitude zones: A1 at low altitude (Chongzhou 450m), A2 at middle altitude (Xichang 2800m), and A3 at high altitude (Litang 3650m). The results showed that the average volume, number, surface area diameter, average branched polymerization degree, crystallinity, and gelatinization temperature of two potato granules in high altitude areas were significantly lower than those in middle and low altitude areas were, and the gelatinization performance of potato starch was affected according to the correlation of starch structure characteristics. Potato starch with more short-branched chains and less long branched chains resulted in a lower gelatinization temperature in high altitude areas. The results showed that Jiusen No. 1 and Qingshu No. 9 were mainly affected by accumulated radiation and accumulated rainfall in Litang, a high altitude area, and by effective accumulated temperature in Xichang, a middle altitude area. This study quantified the influence of meteorological factors on the main starch quality of potato tubers. The results can be used as a theoretical basis for the scientific planting of high-quality potatoes.

Effects of Different Altitudes on Coffea arabica Rhizospheric Soil Chemical Properties and Soil Microbiota

Coffee is one of the most valuable agricultural commodities worldwide, second only to oil in terms of international trade. Coffea arabica L. is a widely cultivated and economically important crop that is responsible for about 90% of the global production of coffee. In this study, we selected five C. arabica cultivation sites at different altitudes to clarify the effects of altitude on rhizospheric soil physical–chemical characteristics and microbial communities. The samples collected at low altitudes were more nutrient-deficient and acidic than the soil samples collected at medium–high altitudes. The Proteobacteria-to-Acidobacteria ratio increased from lower altitudes to medium–high altitudes. Additionally, although Ascomycota was the dominant fungal phylum, it was unaffected by the altitude. Furthermore, the alpha richness and diversity of the bacterial and fungal communities were higher at medium–high altitudes than at low altitudes. Moreover, the redundancy analysis indicated that microbial phyla were closely associated with pH. These findings suggest that C. arabica should be cultivated at medium–high altitudes, which is conducive to sustainable management and the production of high-quality C. arabica beans.

Effect of altitude differences on seed germination and seedling growth in Rhododendron luteum Sweet

The aim of this study is to encourage the use of Rhododendron luteum Sweet, distributed in high altitudes in its natural habitat, in planting designs and landscape architecture and to cultivate these plants by seed propagation. In this context, the effects of different altitudes on R. luteum germination and post-germination seedling growth were investigated. The germination success of R. luteum seeds collected at 3 different altitudes, 1,586 m, 1,760 m and 2,100 m a.s.l., was investigated under greenhouse conditions at a temperature of 25 ± 2 °C and humidity of 70 ± 2% and in soil, peat, soil + peat (5:5), peat + sand (7:3), soil + sand (7:3) and soil + peat + sand (4:4:2) propagation media. The post-germination seedling height, root length, and the number of leaves of the seedlings were determined. Different altitudes had significant effects (P < 0.05) on height, root length, and the number of leaves of the seedlings. The highest germination percentage was 76.69% with the seeds collected from 2,100 m. Furthermore, seedlings that grew from these seeds possessed the best seedling growth with a greater height, longer roots, and a greater number of leaves. Keywords: landscape architecture, Rhododendron luteum, seed propagation, variation

Effects of altitudes on non-structural carbohydrate allocation in different dominate trees in Qilian Mountains, China

Effects of altitudes on non-structural carbohydrate allocation in different dominate trees in Qilian Mountains, China

Effects of altitudes and aspects on wood features of oriental beech in Mt. Uludag (Turkey)

Effects of altitudes and aspects on wood features of oriental beech in Mt. Uludag (Turkey)

Changes of various quality characteristics and aroma compounds of astragalus honey obtained from different altitudes of Adana‐Turkey

In this study, the effects of different altitudes on the physicochemical properties and aroma compounds of astragalus honey were investigated. As the altitude increased, the moisture content of honey samples decreased. Similarly, as the altitude increased, the acidity and the diastase activity of samples increased. Aroma compounds were identified and quantified using the GC-MS-FID. It was determined that with the increasing altitude, the total amount of the alcohol compounds decreased, and the total amount of the lactone compounds and the norisoprenoid compounds increased with the decreasing altitude. Moreover, 11 different aroma compounds with an odor activity value above one were detected. From these compounds, Limonene, (E)-Linalool oxide, (Z)-Linalool oxide, and acetic acid were determined as the powerful odor active compounds in all of the honey samples. The first data on the change of aroma compounds in honey with the effect of altitude were obtained through this study. Novelty Impact Statement Honey, in which many different plant sources are used in the production by honey bees, is an important food item worldwide with its economic and nutritive value. Aroma compounds play an important role in the quality of honey, which is named according to the plant origin from which it is obtained. Through this study, it has been tried to reveal the relationship between the sensorial quality of honey and climate change depending on changing altitude. Hence, in a climate change scenario, the results obtained from this study can help us know what climatic conditions are best for producing high-quality astragalus honey.

Prevalence of and factors affecting otitis media with effusion in children in the region from Balkans to Caspian basin; A multicentric cross-sectional study

ObjectiveThe aim of our study was to contribute to the literature about the prevalence of OME by conducting a research in a wide geography examining most of the associating factors together with a questionnaire. Additionally, possible effects of altitudes and latitudes, concordance between the otoscopic examination findings and tympanometric and acoustic reflex test results were evaluated in 4-7 years old children in the same season in different countries. MethodsIn the randomly sampled schools from different regions of different cities where people of different scoioecomonic statuses live, 4-7 year-old children were included in the study. The results of the questionnaire covering the potential factors in OME etiology were evaluated together with the results of the otoscopic examination and tympanometry findings, and also the acoustic reflex findings to direct the interpretation in cases of low amplitude - blunted peak tympanograms which can be interpreted as a "Type B" or “Type As”. All the results were gathered in the same season. ResultsTen centers from nine countries participated in the study. A total of 4768 children were evaluated. The frequency of OME diagnosed by otosopic examination was 22.48% (n=1072) and the diagnosis rate when otoscopic examination plus type B tympanometry were taken into account was found as 11.3% (n=539) in general population. Factors increasing the prevalence of OME were found as; mother's educational level (p=0.02), child’s age (p=0.006), history of upper respiratory tract infection (p=0.001), smoking father (p=0.01), mother being a housewife or laborer (p=0.01), history of allergy (p=0.001), asthma (p=0.04), or allergy symptoms (p=0.02). No direct relationship was found between altitudes or latitudes and prevalence of OME. ConclusionThe important affecting factors found after analyzing all of the potential risk factors in the same model are secondhand smoke exposure, low level of mother’s education, mother’s occupation, positive history of URTI, and age of the child being less than 7. By paying attention to the factors that increase the prevalence of OME, putting particular emphasis on the preventable ones such as smoking, education, and fighting with allergies could decrease the prevalence of this public health issue.

Integrating Ergonomics Into Safety Management: A Conceptual Risk Assessment Model for Tower Controllers at Multiple Altitudes

Plateau and high plateau airports aggravate tower controllers' vulnerability, facing high safety risks, yet the risk evaluation paradigm to manage safety at multiple altitudes still lacks. The study aimed to investigate the effects of altitudes on controllers' mental workload and fatigue to assess the safety risk and introduced voices, mental workload, and fatigue, into a conceptual risk assessment model. Controllers from the Civil Aviation Administration of China (CAAC) conducted the experimental tasks, reporting mental workload and perception fatigue across three altitudes: 0 m, 2243 m, and 3569.7 m. With experimental data: this research (1) quantitatively compared the voice feature differences with feature engineering, and an image quality measure, (2) explored the effects of altitude, sleep, and fatigue, (3) tested the effects of altitude and task complexity on mental workload, and (4) evaluated the airport safety risks under ergonomic factors. Notably, the study revealed that Log-Mel spectrograms outperformed Mel Frequency Cepstral Coefficients (MFCC) in severe fatigue detection. Altitude and task complexity had significant main effects on the mental workload, but altitude had no significant moderator effects on the relationship between sleep and fatigue. The simulation results show that under the low task complexity, the operation risk is low over three airport elevations (with the human error rate <; 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ), whereas under the high task complexity, the operation risk increased with altitudes (from 1.73×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> to 1.02×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ). Together, these results suggest that ergonomic factors influenced airport safety risk at multiple altitudes and promising real-time fatigue detection with voice features at different altitudes.

Analyzing the effects of altitudes on the metabolic diversity and forskolin content in Coleus forskohlii roots by HPTLC and HPLC

Coleus forskohlii is an important medicinal plant native to India. It grows wild across a wide range of altitudes in the Indian Himalayan region and contains some important phytochemicals that possess remarkable medicinal properties. This plant is the only known source of a medicinally important terpenoid, forskolin, found in its roots. This study was conducted looking at its availability over a wide altitudinal range and medicinal importance. Samples of the five C. forskohlii populations were collected from five altitudes of Uttarakhand, India. HPTLC and HPLC were employed for metabolic diversity analysis. Secondary metabolites were extracted using the Soxhlet extraction, followed by HPTLC fingerprinting and HPLC. Significant differences observed in the HPTLC chromatograms across altitudes. Maximum bands were observed in the HPTLC chromatogram of Gopeshwar population (1488 m a.s.l.). HPLC revealed differences in forskolin quantity among studied populations with the Pipalkoti population (1339 m a.s.l.) showing highest forskolin accumulation. Thus, the present study confirms that altitude and changing environment can affect the nature and quantity of secondary metabolites in C. forskohlii and might be contributory factors for intraspecific metabolic diversity. The Pipalkoti and Gopeshwar populations were found suitable for forskolin and other metabolite production; further, these two populations can be propagated for commercial use.

DIA proteomics reveals hypotensive and immune-enhancing constituents in buffalo whey from different altitudes

The selection of raw milk with high levels of functional components that have health-promoting activities is very important for the exploitation and production of functional milk, but the differences in the functional components of whey from buffalo raised at different altitudes have not been thoroughly investigated. Here, we detected the effects of altitudes on the functional components in whey from dairy buffalo farms situated at low altitude (LA), medium altitude (MA), and high altitude (HA) sites with data-independent acquisition proteomic approaches. In 33 samples, 9331 peptides corresponding to 1008 high-confidence proteins were detected. HA-whey had a lower level of angiotensinogen than that of the LA- and MA-whey, and conversely contained higher levels of immune-enhancing components than for the latter two groups. Differential proteins were involved in vascular smooth muscle contraction, complement and coagulation cascades, and the secretion, production and regulation pathways in immune components. LA-whey showed higher levels of lymphocyte antigen and selenoprotein F than that of the HA-whey. Owing to the biological functions of their most abundant components, HA- and LA-whey are suitable for the processing of functional milk for lowering blood pressure, and the production of immune milk, respectively.

Analysis on Aerodynamic Performance of Single-skinned Parawing in the Hypersonic Rarefied flow

In consideration of the serious aerodynamic heating and overload in the return process of the space vehicles, a single-skinned parawing suitable for the whole return process is proposed, which uses lift deceleration to realize flexible reentry. A three-dimensional steady numerical simulation of the single-skinned parawing with different leading edge sweep angles was conducted by using the direct simulation Monte Carlo method, and the effects of different Mach numbers and altitudes on the aerodynamic performance of the parawing were studied in the hypersonic rarefied atmosphere. The results show that with the increase of the leading edge sweep angle, the aerodynamic performance of the parawing decreases obviously, but the ability of stall resistant is improved. The lift-drag ratio decreases monotonously with the increase of Mach number and altitude. The effect of Mach number on lift-drag ratio is not obvious, but the effect of altitude is more obvious. The maximum lift-drag ratio of parawing is 0.45 at 90 km, but only about 0.1 at 110 km. The peak heat flux always appears near the head, which will decreases obviously by decreasing the flight speed or increasing the flight altitude.

Respon Pertumbuhan, Produksi dan Kualitas Daun Duduk (Desmodium triquetrum (L.) D.C.) Terhadap Ketinggian Tempat Budidaya

Daun duduk (Desmodium triquetrum (L.) DC.) is a medicinal plant containing flavonoid compounds, saponins, polyphenols, and trigonelline. These plants are spread throughout Indonesia especially on Java, Madura, and Sumatra from lowland areas to highlands at an altitude of 5-1,500 m above sea level. Daun duduk has not been widely cultivated. The aim of this study was to determine effects of altitudes to growth, productivity, and quality of daun duduk. The research was carried out in the experimental garden of Medicinal Plant and Traditional Medicine Research and Development Center in January - September 2016. The experiment used a Randomized Block Design in four locations that has different altitudes such as 200, 450 and 1,200 m asl. The results showed that the altitude of location significantly affected the growth, production, and flavonoid contents of daun duduk. The optimal plant height (179.90 cm) was obtained from location at an altitude of 1,200 m above sea level. The highest number and dry weight of leaves were produced in location at an altitude of 200 m asl. While the levels of water soluble extract was 19.7337%, soluble extract levels of ethanol was 18.2837%, and total flavonoid content was 0.249% were obtained at 450 m asl.&#x0D;