Proportion Of Components Research Articles

Volume of hepatoid component and intratumor M2 macrophages predict prognosis in patients with hepatoid adenocarcinoma of the stomach.

Hepatoid adenocarcinoma of the stomach (HAS), a subtype of gastric cancer (GC), includes multiple tumor components, such as enteroblastic and tubular adenocarcinoma components. However, which component mostly contributes to the aggressive behavior of HAS remains unclear. Moreover, the role of tumor-associated macrophages (TAMs) has not been explored in HAS. This study evaluated the clinical significance of the proportion of the hepatoid component within the tumor, CD163 + macrophages, and macrophage colony-stimulating factor-1 (CSF-1) in HAS. In total, 56 cases of primary HAS were analyzed. In each case, hepatoid (HC), enteroblastic (EC), and tubular (TC) components were identified, and the ratio of HC to the entire tumor (hepatoid component ratio, HCR) was assessed to examine the correlation between HCR and clinicopathological features. Immunohistochemical staining for CD163 and CSF-1 was performed, and differences in immunohistochemical results among the three tumor components were analyzed. In each tumor component, the prognostic impact of CD163 and CSF-1 was examined. A high HCR was associated with worse overall survival (OS). CD163 + TAMs and CSF-1 immunoreactivity score in HC were significantly higher than those in the other components. High infiltration of CD163 + TAMs and a high CSF-1 immunoreactivity score in HC were associated with an aggressive course and worse OS. Multivariate analysis revealed the proportion of HC in HAS as an independent prognostic factor (HR = 3.176, p = 0.006). The HCR and CD163 + TAMs may be useful prognostic predictors, and TAMs may be novel therapeutic targets of HAS.

The ad 79 Vesuvius eruption revisited: the pyroclastic density currents

Seventeen pyroclastic density currents (PDCs) were produced before, during and after the Plinian phase of the ad 79 eruption of Vesuvius. Their deposits were correlated using the proportions of components, together with the recognition of distinctive intercalated regionally traceable fall marker layers, revealing sectoral and distance-dependent variations. During an extensive field analysis, 27 lithostratigraphic units were detected and mapped and the lateral and vertical variations of 15 lithofacies were documented, described and interpreted. The total volume of PDC units is 1.25 km 3 . We consider that the early PDCs were generated by partial collapses from the sustained Plinian eruption column, whereas the subsequent post-Plinian PDCs were generated by more sustained pyroclastic fountaining. New facies mapping revealed lateral migration and extended travel distances for some of the currents. Most of the lobed PDCs remained relatively uniform, whereas the radial PDCs exhibited fluctuating waxing and waning pulses and changed gradationally down-current. Re-evaluation of the timing of caldera collapse and the transition from a magmatic to a phreatomagmatic eruption style suggests that substrate fracturing during incremental caldera subsidence may have allowed the gradual ingress of groundwater into the erupting magma. These results provide a new chronology of the eruption, revealing that the post-Plinian collapse phase lasted c. 12 h.

Effect of Artificial Humic Acids Derived from Municipal Sludge on Plant Growth, Soil Fertility, and Dissolved Organic Matter

Due to its high nutrient utilization efficiency, liquid organic fertilizer has become a research hotspot in the field of agricultural planting. Artificial humic acids, which are near-nature products, can be deemed as a green liquid organic fertilizer, but few studies have been reported, which has limited their further application. In this study, artificial humic acids were derived from municipal sludge, and their effect on rice growth, soil fertility, and dissolved organic matter was investigated using multi-chamber root box experiments. The shoot and root biomass of rice can be significantly enhanced by artificial humic acids, and the heavy metal concentration in rice was within safe limits. Artificial humic acids can limit the decrease in soil pH, especially in the far-rhizosphere zone, and improve the distribution of nutrients in the rhizosphere, near-rhizosphere, and far-rhizosphere zones. The use of artificial humic acids led to a significant decrease in soil electrical conductivity. The dissolved organic carbon content in the root zone was significantly increased, and the fluorescence intensity of dissolved organic matter in the rhizosphere was significantly increased. The proportion of specific components of dissolved organic matter was just slightly changed in the rhizosphere and near-rhizosphere zones. Artificial humic acids promoted the humification of dissolved organic matter in the near-rhizosphere and far-rhizosphere zones. The findings indicate that the environmental impact of artificial humic acids is significantly different from conventional chemical fertilizers, and they show huge potential in the agriculture field.

Comparison of Judgment Document Information Between China and Russia Based on Corpus

The study of legal comparisons has become particularly important as the number of foreign-related legal disputes has increased dramatically with the growing number of cross-border trade. This study discovers the differences and similarities between Chinese and Russian judgment documents and provides a linguistic basis for the academic theoretical researches and the call for linguists to enter the courtrooms by establishing a corpus of Chinese and Russian judgement documents, quantifying and analysing the Chinese and Russian judgement documents based on the Legal Discourse Information Theory. It can be found that the macro-structure of civil ruling documents is clearer but does not provide more micro-information. By adding language elements, it can be seen that there are more information points and information components in Russian criminal judgment documents. The information points in Chinese civil judgment documents are more concentrated than in Russian civil judgment documents, while they are more similar in terms of the proportion and type of information components.

Evaluation of lipid profiles in selected fresh and dry-cured game meats

This study examined and compared the fatty acid (FA) composition and fat quality indices of four types of wild game meat (deer, roe deer, mouflon, and wild boar) from Croatia, and two types of dry-cured game meat products (deer and wild boar) available on the market, in relation to their impact on consumer health. FAs were analysed by gas chromatography coupled with a flame ionization detector, and fat quality indices were calculated based on the determined FAs. Wild boar meat clearly differs from other game meat (ruminants), due to its higher fat content and higher proportion of monounsaturated fatty acids (MUFA) compared to saturated fatty acids (SFA). Palmitic and stearic acids made up the greatest proportion of the SFA component, with stearic acid most represented in mouflon and roe deer meat, and palmitic acid predominating in wild boar and deer meat. Oleic acid was the largest component of MUFAs, with wild boar meat having the significantly highest and deer meat the lowest values. Linoleic acid and α-linolenic acid made up the largest proportion of polyunsaturated fatty acids (PUFAs), with the highest proportion of α-linolenic omega-3 acid found in deer meat. The determined PUFA/SFA ratio was lower, while the thrombogenic index was above the recommended values. Wild boar meat, along with roe deer and mouflon meat, was compliant with the recommendations concerning hypo- to hypercholesterolemic fatty acids and atherogenic indices, while deer meat and roe deer meat were compliant only for the n-6/n-3 ratio. According to health recommendations, roe deer meat showed the most favourable values for most fat quality indices, while deer meat showed the least favourable values. When comparing fresh meat and dry-cured products from the same species, no significant differences were observed.

Increased Proportion of the Squamous Cell Carcinoma Components Is Associated with Aggressive Behavior and a Worse Prognosis in Resected Pancreatic Adenosquamous Carcinoma.

Pancreatic adenosquamous carcinoma (PASC) is a subtype of pancreatic cancer with a poorer prognosis than pancreatic ductal carcinoma (PDAC). The pathogenesis of this histological subtype has not been fully explained due to its rarity. Of the 245 patients who underwent pancreatic resection for pancreatic cancer, six (2.3%) were diagnosed with PASC. They were retrospectively allocated to Group A (≥ 50% adenocarcinoma components) or Group S (≥ 50% squamous cell carcinoma components). The six patients with PASC were all males between the ages of 63 and 77years, with tumors of 12 to 52mm in diameter. Tumors were located in the pancreatic head (n = 2) and the pancreatic tail (n = 4). Relative to Group A, all three patients in Group S had larger tumors diameters, ≥ 40mm with invasion to other organs. Cancer-specific survival of Group S was worse than that of the PDAC group (median survival, 1.5years vs. 4.1years). All patients in Group A were alive at the end of follow-up. Recurrence-free survival of Group S was inferior to that of the PDAC group (median survival, 0.2years vs. 1.8years; Group A, not defined). Immunohistochemistry revealed the MIB-1 positivity rate in squamous cell carcinoma regions was 1.8 times higher than that in adenocarcinoma regions in the same specimens. In PASC patients, an increased proportion of squamous cell carcinoma components was associated with aggressive behavior and a worse prognosis. This was due to the high MIB-1 positivity rate of squamous cell carcinoma components.

High water use efficiency due to maintenance of photosynthetic capacity in sorghum under water stress.

Environmental change requires more crop production per water use to meet the rising global food demands. However, improving crop intrinsic water use efficiency (iWUE) usually comes at the expense of carbon assimilation. Sorghum is a key crop in many vulnerable agricultural systems with higher tolerance to water stress (WS) than most widely planted crops. To investigate physiological controls on iWUE and its inheritance in sorghum we screened 89 genotypes selected based on inherited haplotypes from an elite or five exotics lines, containing a mix of geographical origins and dry vs. milder climates, which included different aquaporin (AQP) alleles. We found significant variation among key highly heritable gas exchange and hydraulic traits, with some being significantly affected by variation in haplotypes among parental lines. Plants with a higher proportion of the non-stomatal component of iWUE still maintained iWUE under WS by maintaining photosynthetic capacity, independently of reduction in leaf hydraulic conductance. Haplotypes associated with two AQPs (SbPIP1.1 and SbTIP3.2) influenced iWUE and related traits. These findings expand the range of traits that bridge the trade-off between iWUE and productivity in C4 crops, and provide possible genetic regions that can be targeted for breeding.

Clinicopathological characteristics and prognosis of combined hepatocellular cholangiocarcinoma

There is limited research on the clinicopathological characteristics of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) currently. The aim of this study is to summerize the clinicopathological factors and prognosis of cHCC-CCA, which could help us understand this disease. 72 cases of cHCC-CCA from West China Hospital of Sichuan University were collected. Tissue components were reviewed by pathologists. Immunohistochemistry was used to detect the status of mismatch repair (MMR) and human epidermal growth factor receptor 2 (HER2) in cHCC-CCA, as well as the quantity and distribution of CD3+ T cells and CD8+ T cells. Fluorescence in situ hybridization was used to detect fibroblast growth factor receptor 2 (FGFR2) gene alteration. COX univariate and multivariate analyses were used to evaluate risk factors, and survival curves were plotted. 49 cases were classified as classic type cHCC-CCA and 23 cases as intermediate cell carcinoma. The cut-off value for diagnosing classic type was determined to be ≥ 30% for the cholangiocarcinoma component based on prognostic calculations. All tumors were MMR proficient. The rate of strong HER2 protein expression (3+) was 8.3%, and the frequency of FGFR2 gene alteration was 26.4%. CD3+ T cells and CD8+ T cells were mainly distributed at the tumor margin, and were protective factors for patients with cHCC-CCA. The overall survival of the 72 patients was 18.9 months, with a median survival of 12 months. Tumor size, TNM stage, and serum AFP level were prognostic factors for cHCC-CCA. The proportion of cholangiocarcinoma component reaching the threshold of 30%, may provide a reference for future pathology diagnosis. FGFR2 gene alteration was 26.4%, providing a clue for anti-FGFR2 therapy. However, more data is needed for further verification.

Assessment of angular distribution of sound scattering in enclosures

This study proposes an approach for quantitatively assessing sound scattering degrees caused by objects within enclosures. It categorizes the high-frequency sound fields in rooms into two distinct components: (1) specular reflections arising from boundary surfaces, and (2) non-specular scattering contributed by objects (interiors). To achieve this, sound fields sampled on a sphere for two scenarios, with and without interiors, were decomposed into plane waves. The coherence between the impulse responses of these plane waves for these two scenarios is analyzed to obtain the proportion of specular and non-specular components within the room containing interiors. Derived from these coherence curves, the Equivalent Scattering Coefficients (ESCs) quantify the degree of scattering distributed across various directions, reflecting the interaction of sound waves with these interior elements. The extracted ESCs facilitate to quantification of the proportion of specular and non-specular components, which can be efficiently modeled separately and combined in a hybrid acoustic model, offering significant potential for sound field reconstruction.

Consecutive annual mowing reduces soil respiration and increases the proportion of autotrophic component in a meadow steppe

BcakgroundSoil respiration (Rs), as the second largest CO2 emissions of terrestrial ecosystems, is sensitive to disturbance and consequent environmental changes. Mowing is strategically implemented as an management approach and has the potential to influence carbon cycling in meadow steppes. However, it remains unclear how and why Rs and its heterotrophic (Rh) and autotrophic (Ra) components respond to consecutive mowing and associated ecological consequences. Here, we conducted a field mowing experiment in a meadow steppe in 2018 and monitored Rs, Rh, and Ra from 2019 to 2022.ResultsWe observed a significant reduction in Rs by 4.8% across four years, primarily attributed to a decrease in Rh. This decline in Rs intensified over time, indicating an accumulative effect of mowing. In addition, mowing induced an generally increasing Ra/Rs ratio over the experimental years with a simultaneous increase in the ratio of belowground to aboveground biomass (BGB/AGB). Furthermore, structural equation modeling results revealed that the decline in Rs was largely ascribed to reduced microbial biomass carbon (MBC) under mowing, while the increased Ra/Rs was primarily explained by the enhanced BGB/AGB. Partial regression analysis suggested that the biotic factor of microbial biomass dominated changes in soil respiration induced by mowing rather than abiotic soil temperature.ConclusionsOur findings showed that consecutive mowing decreased Rs and raised Ra/Rs in meadow steppe by decreasing plant biomass and altering the proportion of biomass allocation. This observed decline in Rs would help to reduce CO2 concentration in atmosphere as well as alleviate global warming. However, considering the concurrent lower microbial biomass, the potential positive impacts of mowing on climate and ecosystem function should be reevaluated in future grassland management practices.

Synergistic effects of boron and cadmium on the metal enrichment and cell wall immobilization capacity of Cosmosbipinnatus

Cadmium (Cd), as a heavy metal pollutant, can seriously affect plant growth and development. Boron (B), as an indispensable nutrient element, plays an important role in plant growth and cell wall (CW) synthesis. However, the physiological effects of B and Cd on plant growth and the mechanism of Cd chelation by the CW remain unclear. Here, we investigate the effect of exogenous B on Cd accumulation in CW components of Cosmos bipinnatus roots and its mechanism of Cd mitigation. Under B deficiency and single Cd (30 μM) treatments, the growth of C. bipinnatus was significantly inhibited, but the addition of exogenous B significantly increased plant biomass, which increased the Cd content in the underground parts of C. bipinnatus by 20.18% and reduced the Cd translocation factor by 22.22%. Meanwhile, application of exogenous B affected the subcellular Cd content across various Cd forms and alleviated Cd-induced oxidative stress in C. bipinnatus. Additionally, exogenous B and Cd and their mixtures affected the functional groups of the root CW, the proportion of polysaccharide components, the Cd content of polysaccharides, and the polysaccharide uronic acid content of C. bipinnatus. However, B application increased 3-deoxy-oct-2-ulosonic acid content, pectin esterase activity, low esterified pectin content, and its Cd content by 149.52%, 55.69%, 206.38%, and 150.02%, respectively, compared to Cd treatment alone. Thus, our study showed that B mitigates the toxicity of Cd to plants, revealing the effect of B on the physiological aspects of Cd tolerance in plants.

Preoperative markers for identifying CT ≤2 cm solid nodules of lung adenocarcinoma based on image deep learning.

The solid pattern is a highly malignant subtype of lung adenocarcinoma. In the current era of transitioning from lobectomy to sublobar resection for the surgical treatment of small lung cancers, preoperative identification of this subtype is highly important for patient surgical approach selection and long-term prognosis. A total of 1489 patients with clinical stage IA1-2 primary lung adenocarcinoma were enrolled. Based on patient clinical characteristics and lung imaging features obtained via deep learning, highly correlated diagnostic factors were identified through LASSO regression and decision tree analysis. Subsequently, a logistic model and nomogram were constructed. A restricted cubic spline (RCS) was used to calculate the optimal inflection point of quantitative data and the differences between the groups. The three-dimensional proportion of solid component (PSC), sex, and smoking status was identified as being highly correlated diagnostic factors for solid predominant adenocarcinoma. The logistic model had good prediction efficiency, and the area under the ROC curve was 0.85. Decision curve analysis demonstrated that the application of diagnostic factors can improve patient outcomes. RCS analysis indicated that the proportion of solid adenocarcinomas increased by 4.6 times when the PSC was ≥72%. A PSC of 72% is a good cutoff point. The preoperative diagnosis of solid-pattern adenocarcinoma can be confirmed by typical imaging features and clinical characteristics, assisting the thoracic surgeon in developing a more precise surgical plan.

Ti- and Ba-rich phlogopitic micas in alkaline basic and upper mantle igneous rocks; stoichiometry, stability, and Fe valence estimation reassessed and rationalised

Ti- and Ba-rich tri-octahedral micas occur in fractionated basic igneous rocks, metasomatized mantle peridotites, metamorphosed pelites/carbonates, and hydrothermally altered mineral deposits. Electron microprobe analyses (EMP), with all iron reported as FeO, were widely used in the 1970/80s to interpret Ti and Ba substitution mechanisms, based on 22 O2– unit cell calculations, implying that cation vacancies occur in octahedral and/or intersheet sites. In 1996 EMP with chemical and physical analyses for ferric and total Fe, H2O, (OH), and element-specific Fe X-ray Absorption Spectroscopy (both K and L-edges) established valence states for Fe and Ti and cation site occupancies, that ∼50 % O replaces (OH) molecules, and that 24 anion cell formulae show the absence of cation vacancies. Cell formula calculation protocol for phlogopitic micas is refined here and results tested against the stoichiometric formula for vacancy-free phlogopite, XIIK2VIMg6IV[Si6Al2]O20(OH)4. Hypothetical sheet silicate compositions, calculated with fixed contents of vacancies linked to particular mixed-valence element substitutions, confirm that reliable unit cell formulae for natural mica solids require that each stoichiometric vacancy must be accounted for. If reliable estimates for ‘excess O’ (denoted WO2−) are assigned to EMP analyses, the proportion of the oxy-mica component in a mica solid solution can be defined. This approach is tested using published analyses for Ti- and Ba-rich biotites from fractionated basic and ultramafic volcanic igneous rocks (oxymica range 2.5–45 %; TiO2 up to 14 %; BaO up to 23 %), upper mantle peridotites (equivalent values 7–18 %; 6 %; 0.7 %), and metasomatised upper mantle (2–37 %; 9 %; 23 %). Enrichments of Ti and Ba in micas are clearly linked to the extra oxygen charge required to neutralise the more highly charged Ba2+ and Ti4+ replacing K+ and Mg2+.Substitution mechanisms involving Ba, Ti, and Fe3+ in ideal phlogopite involve coupled inter-site / inter-valence interactions so both site-ordering and valence-balance between the different cation sites must be accounted for. The cation exchange 2XIIK+ + 4VI(Mg2+ + Fe2+) + 4IVSi4+ ↔ XIIBa2+ + 3VITi4+ + 4(Altotal + Fe3+ + Crtotal)3+ is used here so that valence and site order can be considered together. Compositional variations show well-defined trends towards high-oxymica content and vacancy-free Ti and Ba mica end-members, rather than to oxy-free end-members with essential vacancies. Average compositions for different source rock micas are used to assess compositional trends; molecular WO2− values are refined by relating initial estimates directly to the wt.% TiO2 contents; and refined WO2− and stoichiometrically calculated Fe3+/Fetotal ratios ranging ∼0.1–0.5) are correlated with possible primary magmatic values.

Transformation of Biochar from Plant Biomass in Gray Forest Soil: Evaluation by Isotopic Labeling Method

Pyrolysis is considered to be one of promising methods for processing agricultural waste and for producing fertilizers. The efficiency of the resulting biochar as a fertilizer has been proven, but the preferential way of decomposition of organic substances in it—biotic or abiotic—is still open to argument. The ways of transformation of biochar obtained from corn (a plant of the C4 type of photosynthesis with an increased 13C content) were assessed in this work, using the solid-phase CP/MAS 13C NMR spectroscopy. Biochar was placed into the top layer of a monolith of gray forest soil, and the precipitation regime characteristic of Central Russia was simulated for 90 days. The peak at 129 ppm typical for aromatic compounds increased during the experiment in the obtained NMR spectra of soil samples with biochar in the upper soil layer, but not in other layers. This testifies that biochar particles do not migrate down the soil profile during one season. The intensity of cumulative microbial respiration in the presence of biochar increases from 85.0 g CO2 kg–1 in the control sample to 201.4 g CO2 kg–1 in the sample with biochar (the topsoil). According to the NMR spectra of the salt formed during mineralization of carbon dioxide released from the soil, it contains labeled carbon: there is a peak at 169 ppm characteristic of carbonates. The cumulative volume of CO2 released from the soil with biochar is 1.9 times greater as compared to the control soil. The addition of microorganisms-decomposers caused an additional increase in the CO2 volume: 2.4 times relative to the control, which indicates the role of microorganisms in the destruction of soil organic matter and of biochar. However, based on the stability of the total carbon content in the soil, it can be concluded that only a small proportion of biochar components is susceptible to biotic decomposition.

Geochemical and mineralogical assessment of environmentally sensitive elements in Neyveli lignite deposits, Cauvery Basin, India.

This research work presents an examination of the concentrations and modes of occurrence of environmentally sensitive elements within lignite deposits, located in Neyveli, within the Cauvery Basin of India. Coal is one of the most complex geologically formed materials, consisting of organic and inorganic matter. The inorganic mineral matter including thecrystalline minerals, non-crystalline mineraloids, and elements with non-mineral associations. These lignite samples underwent complete analysis encompassing macroscopic, microscopic and geochemical assessments. The analysis reveals that the total mineral matter (MM) content, comprising significant proportions of sulphides, carbonate and argillaceous components. Geochemical characterization further elucidates the lignite's properties, with proximate analysis yielding values such as ash, volatile matter and fixed carbon and the Ultimate components analysis reveals the carbon, hydrogen, nitrogen, sulphur and oxygen. Inorganic mineral matters play a significant role in coal utilization, and also such modes of occurrence of elements provide useful geochemical information on coal formation and coal-bearing basin evolution. In this paper, we assess the associations of elements and minerals, as well as the associations of selected elements including environmentally-sensitive (e.g., S, As, U, and Hg), and some major elements (e.g., Ca, Mg, Fe, Al, and Ti) that have largely occurred in non-mineral forms in these low-rank coals. And also, comparative analysis is conducted between the concentrations of elements within the lignite samples and the values reported for World Clarke Brown Coals (WCBC). Particularly, some of these elements exhibit significantly high environmental sensitivity, demanding careful consideration in lignite extraction and utilization practices.

Research of the processes of ignition and combustion of mixed fuels based on coal and wood under different conditions of thermal influence

The ignition processes of mixed fuels formed on the basis of grade 3B coal from the Maikuben deposit and finely dispersed sawmill and woodworking waste have been studied. An analysis of the processes of ignition and combustion of fuel mixtures with different organization of combustion processes was performed. It has been established that the concentration of the wood component has a significant impact on the processes of the onset of oxidation and combustion of mixed fuels. When the proportion of wood component in the mixture increases to 50%, the ignition delay time decreases by an average of 18% in all cases of the studies performed.

Moisture damage mechanism of asphalt mixtures containing reclaimed asphalt pavement binder: A novel molecular dynamics study

Reclaimed asphalt pavement (RAP) stands at the forefront of sustainable practices in road construction and rehabilitation. However, concerns regarding the moisture susceptibility of aged RAP binder have arisen due to its potential hazard to pavement durability. So far, the underlying mechanisms of how moisture infiltrates into the mixture and results in binder stripping remain controversial and scarcely investigated. To address this challenge, a novel molecular dynamics (MD) simulation method has been developed to explore the nanoscale stripping mechanisms, considering the effects of asphalt oxidative aging and rejuvenation. The results indicate that hydrogen bonding interactions between water and the aggregate surface reduce the contact distance compared to the distance between asphalt and aggregate. Under pore water pressure, moisture diffuses into the interface, occupying the van der Waals adhesion sites of asphalt molecules and consequently causing detachment. Asphalt oxidative aging, on one hand, increases the oxygen concentration and hydrophilicity, thereby increasing moisture susceptibility from the energy perspective. On the other hand, it increases the intermolecular friction between aged asphalt molecules, leading to reduced flexibility and age hardening, consequently triggering asphalt premature detachment and diminishing its coating quality on the aggregate surface. Rejuvenators can restore the moisture sensitivity of severely aged asphalt, with a mechanism involving two aspects: firstly, reducing the agglomeration and proportion of polar components in asphalt, thereby weakening its hydrophilicity; secondly, lubricating aged asphalt molecules to restore their flexibility and surface coating properties. Findings from this study contribute to revealing the moisture-induced damage mechanism when recycling RAP binder.

Three-dimensional transient modeling and simulation of high-current multi-component vacuum arc under transverse magnetic field

This paper established a three-dimensional transient MHD model of a high-current multi-component vacuum arc under a transverse magnetic field (TMF) to simulate the dynamic characteristics of plasma parameters in the uniform motion mode of a contracted arc under lower TMF. The model considered the ionization–recombination process among the multi-components and used the P1 model to calculate the thermal radiation losses. The simulation results show that the ion number density of The TMF arc is on the order 1024 m−3, and when the plasma temperature reaches 4.3 eV, the effects of thermal radiation cannot be ignored. The majority of the plasma from the cathode and anode undergo acceleration and then deceleration before finally intersecting at the center of the arc, creating an extreme value of the density and the pressure, where a large amount of kinetic energy is converted into internal energy. The arc will be bent and deflected under the action of the ampere force, and the deflection of Cu3+ is especially obvious. The TMF affects the collision strength of the jet in the intersection area and, thus, affects the ion density, in which the change of Cu2+ is dominant. The ionization–recombination process of ions is mainly determined by the electron temperature, which is affected by the arc current. As the current decreases, Cu1+ increases and Cu2+ and Cu3+ decrease, and the change in ionization rate is the main reason for the change in the proportion of each ionic component; the heat flux density to the anode and cathode is on the order of 1010 W/m2, which heats the front of the arc and ensures the stable movement of the arc. Meanwhile, due to the high ion number density, the ion heat flux accounts for the main part of the heat flux, and the anode exhibits a higher proportion of ion heat flux.

Divergent response of Chernozem organic matter towards short-term water stress in Poa pratensis L. rhizosphere and bulk soil in pot experiments: A spectroscopic study

Understanding and controlling rhizospheric processes under abiotic stress is one of the key challenges in addressing food security amid the climate crisis. In this work, the impact of short-term drought and overwatering on soil organic matter (SOM) of Haplic Chernozem in the rhizosphere of Poa pratensis L. and in bulk soil was investigated. The vegetation experiment was conducted in a climatic chamber at soil moisture levels of 35, 80, and 200 % of the field capacity. UV-Vis and spectrofluorometry were used to describe the water-extractable organic matter (WEOM) characteristics and fluorofores signature, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to describe functional group composition of SOM. Composition and properties of SOM and WEOM of Chernozem significantly change after exposure to short-term water stress. Drought does not affect the composition of rhizosphere SOM except increasing the proportion of polysaccharides, but leads to the decrease in aromaticity and increase in molecular weight of humic-like components of rhizosphere WEOM. These findings reflect Poa adaptation to water deficiency and microbial activity suppression which results in accumulation of SOM intermediate decomposition products. On the contrary, bulk WEOM wasn't affected by drought but SOM became enriched with aromatic and oxidised components. Overwatering leads to equalisation of bulk and rhizospheric SOM composition due to a decrease in the proportion of aromatic and carboxylic components of bulk SOM and the accumulation of microbial products in both bulk and rhizospheric SOM. In general, rhizospheric WEOM undergoes relatively significant changes relative to the optimum water regime under moisture deficit, and bulk WEOM — under overwatering. The findings illustrate the involvement of the both WEOM and SOM in maintaining resilience of the soil-plant system as well as the difference in watering conditions impact on SOM in rhizosphere and bulk soil. SOM spectral data can be used for assessing the state of soil systems, such as changes in microbial activity and adaptation of the soil-plant system to abiotic stress. Our findings also illustrate the differences in the organic matter transformation of the Poa pratensis rhizosphere and the bulk Chernozem depending on environmental factors.

Allometric equations for biomass and carbon pool estimation in short rotation Pinus radiata stands of the Western Cape, South Africa

AbstractThe quantification of tree growth and carbon storage over time is an important task for sustainable forest management and carbon sequestration projects. For the South African short-rotation Pinus radiata (D. Don) forests, this knowledge is lacking. We developed allometric equations and compared the estimated weights to previously published biomass studies and we used Dirichlet Regression (DR) modelling to ensure additivity of the component proportions. The biomass components and their contribution to carbon storage depend strongly on forest structure and mean tree size but also on-site conditions and tree architecture. Our first two hypotheses were that the (1) best model for stemwood (SW), bark and total mass will include the combined variable DBH2H and (2) that the DR will yield statistically similar estimates for all components when compared to the best models. Our third hypothesis was that allometric equations developed for sites with high resource availability (e.g. wet, fertile sites) will yield biased estimates when extrapolated to sites with lower levels of resource availability (drier and/or infertile sites). The results indicated that DBH2H was the best variable to describe SW, bark and total mass and the DR yield similar estimates for all component proportions when compared to the best models. There were strong similarities in the SW and total mass of independent test sites in comparison to the SW and total mass of this study but greater variability in the bark, needle and branch mass. This can be associated to site and seasonal differences as well as variability in tree architecture brought about by different silvicultural operations on individual sites. Previously developed equations by other authors for sites with high resource availability overpredicted the SW and total mass of the models developed in this study. Our set of additive component equations performed well even when applied to sites of similar productivity over a climate gradient. The presented new equations bridge the gap in knowledge where allometric equations for short rotation Radiata pine stands are lacking.