Directional Correlation Research Articles

Analysis of the fluorescence spectral characteristics of dissolved organic matter in a black soil with different straw return amounts

Straw return improves soil carbon pool and dissolved organic matter (DOM) characteristics in black soil. Optimal straw return rate is the key to promoting straw return practices in farmland in Northeast China. The experiment was conducted at the Science and Technology Park of China Grain Storage and Northern Corporation in NenJiang, Heilongjiang Province, straw return at 0 kg hm−2, 3000 kg hm−2, 4500 kg hm−2, and 9000 kg hm−2. In the seventh year of the experiment, we used three-dimensional excitation-emission matrices combined with Parallel Factor analysis to characterize the fluorescence characteristics of DOM of black soils. The results showed substantial improvement in soil physical characteristics and soil organic matter (SOM) following straw return, SOM content rises in proportion to the amount of straw returned, and a significant positive correlation coefficient between water-holding capacity (WHC) (p < 0.001, r = 0.82) and dissolved organic matter (DOC) (p < 0.01, r = 0.77). Moreover, straw return significantly increased the richness of three fluorescent components, namely fulvic acid (UV and visible fulvic acids), humic-like acid, and protein-like (short and long-wavelength tryptophan). The fluorescence intensities of these components were lower in straw treatments than in no straw return. The fluorescence intensities of fulvic and humic acids showed decreasing and increasing trends, respectively, with increasing straw return amount. The fluorescence spectroscopy data of DOC demonstrated the key role of high straw return amounts in enhancing substantially the metabolic activity of soil microorganisms. Overall, straw-returning practices improve soil fertility and can be beneficial for black soil farmlands, with the optimal return rate observed at 4500 kg hm−2.

Phase angle as a marker of muscle quality: A systematic review and meta-analysis

Background & aimsPhase angle (PhA) is a biomarker derived from raw bioelectrical impedance analysis (BIA) values: resistance (R) and reactance (Xc). PhA reflects cellular membrane integrity and, as a result, has been considered a marker of fluid distribution, making it a potential prognostic indicator. A growing body of research demonstrates independent associations between PhA and muscle strength, mass, and composition. In this context, PhA has the extra potential to serve as a marker of muscle quality. However, the evidence supporting its use for this purpose is not well established. This study aimed to investigate the relationship between PhA and markers of muscle quality. MethodsThis systematic review and meta-analysis (Internal Prospective Register of Systematic Reviews – PROSPERO on a registration code: CRD42024507853) focused on observational studies assessing the relationship between PhA and markers of both concepts of muscle quality: the muscle quality index (MQI: strength by a unit of mass) and the muscle composition (i.e., skeletal muscle radiodensity [SMD], muscle echogenicity, muscle fat fraction, inter- and intramuscular adiposity). Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2), while the certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Meta-analyses with a random-effects model were conducted. ResultsSeventeen studies were included in this systematic review, encompassing 2,710 participants. Meta-analyses demonstrated that PhA had a moderate positive correlation coefficient with SMD (4 studies, 924 participants; r = 0.54, 95% confidence interval (CI) 0.38 to 0.69, heterogeneity (I2) = 92%) and good accuracy (85%) for classifying low SMD (2 studies, 390 participants; Area Under the Curve – AUC pooled 0.85, 95% CI 0.78 to 0.92, I2 = 0%). PhA was inversely-moderately correlated with muscle echogenicity (8 studies, 1,401 participants; r = - 0.42, 95% CI - 0.57 to - 0.24, I2 = 82%) and positively-weakly correlated with MQI (2 studies, 191 participants; r = 0.36, 95% CI 0.21 to 0.49, I2 = 17%). All studies had a higher risk of bias. The certainty of evidence ranged from low to very low. ConclusionDespite technical challenges, this study demonstrates the potential of PhA as a surrogate marker for muscle quality, particularly expressing muscle composition (SMD). Future studies should utilize BIA with standardized protocols to potentially establish specific cutoff values for PhA, thereby enhancing its diagnostic accuracy and clinical applicability. These studies could additionally explore the mechanisms underlying the associations between PhA and muscle quality aspects. In cases where technical factors are not easily controlled, the use of standardized PhA (SPhA), which converts PhA into Z-scores, could be beneficial. Although this warrants investigation, this approach (SPhA) has the potential to account for variables such as age, sex, device differences, and health status.

Modulating the tumor microenvironment in a mouse model of colon cancer using a combination of HIF-1α inhibitors and Toll-Like Receptor 7 agonists.

The immunosuppressive tumor microenvironment (TME) plays a pivotal role in the response to various anticancer therapies, such as immune and chemotherapeutic agents. In this study, the synergistic effects of gene-targeting HIF-1α siRNA combined with Toll-Like Receptor 7 agonist on TME remodeling were investigated in a mouse model of colorectal cancer (CRC). A HIF-1α-specific siRNA duplex was formulated based on the ionic gelation of tripolyphosphate (TPP) with cationic chitosan (CH) as a nanoplex and evaluated in terms of size, charge, polydispersity index and gel retardation assay. MTT assay was conducted to assess the cytotoxicity of the specific siRNA duplex against CT26 cells. Hypoxic condition was generated to evaluate the gene and protein expression levels of HIF-1α, respectively. CT26 mouse model was established to assess the synergistic effect of silencing HIF-1α combined with oxaliplatin (OXA) and imiquimod (IMQ) on tumor growth. The mean diameter of the CH/siRNA nanoparticles was 243 ± 6 nm, as confirmed with Micrograph scanning electron microscope. There were no significant differences observed between the CT26 cells treated with nanoparticles alone and the untreated cells, indicating that these nanoparticles are safe and physiologically biocompatible (p ≥ 0.05). Triple combination therapy involving HIF-1α siRNA, OXA, and IMQ significantly retarded tumor growth and led to elevated levels of cytokines linked to cellular immunity (INF-γ and IL-12) compared with those in the other groups (P < 0.05). The positive correlation coefficient (r = 0.68) between tumor size and HIF-1α expression levels was statistically significant (P = 0.003). Compared with those in the control group, the expression levels of the anti-inflammatory cytokines IL-10 and IL-4 significantly decreased (P < 0.05). In conclusion, our findings suggest that inhibiting HIF-1α could serve as a rational strategy to enhance the antitumor response in the TME.

Factors of individual differences between the speeds of the hand and ball during baseball pitching: Assessment of middle finger function based on the hierarchical linear model

ABSTRACT This study aimed to reveal individual differences between the speeds of the hand and ball and clarify the factors affecting those differences. Motion data from 20 highly skilled baseball pitchers, captured using a 16-camera motion analysis system with a sampling frequency of 1,000 hz, were used for correlation and hierarchical linear model analyses. For the hierarchical linear models, the speed of the metacarpophalangeal joint was the independent variable in the 1st level. The independent variables chosen in the 2nd level were the variables regarding the finger length, mean peak angular velocities, and mean peak accelerations of the middle finger joint. Intra-subject correlation analysis showed high positive correlation coefficients between the metacarpophalangeal joint and ball speeds, ranging from 0.803 to 0.992. The difference between the hand and ball speeds ranged from 8.4 m∙s−1 to 12.0 m∙s−1. The hierarchical linear model analyses indicated that the individual differences between the speeds of the hand and ball were partly accounted for by the mean peak accelerations of the proximal and distal interphalangeal joints, suggesting that the force exerted by proximal interphalangeal joint flexion plays an important role in ball speed increment.

Critical factors influencing electron and phonon thermal conductivity in metallic materials using first-principles calculations

Understanding the thermal transport of various metals is crucial for many energy-transfer applications. However, due to the complex transport mechanisms varying among different metals, current research on metallic thermal transport has been focusing on case studies of specific types of metallic materials. A general understanding of the transport mechanisms across a broad spectrum of metallic materials is still lacking. In this work, we perform first-principles calculations to determine the thermal conductivity of 40 representative metallic materials, within a range of 8-456 W mK-1. Our predicted values of electrical and thermal conductivity are in good agreement with available experimental results. Based on the data of separated electron and phonon thermal conductivity, we employ a statistical approach to examine nine factors derived from previous understandings and identify the critical factors determining these properties. For electrons, although a high electron density of states around the Fermi level implies more conductive electrons, we find it counterintuitively correlates with low electron thermal conductivity. This is attributed to the enlarged electron-phonon scattering channels induced by substantial electrons around the Fermi level. Regarding phonons, we demonstrate that among all the studied factors, Debye temperature plays the most significant role in determining the phonon thermal conductivity, despite the phonon-electron scattering being non-negligible in some transition metals. Correlation analysis suggests that Debye temperature has the highest positive correlation coefficient with phonon thermal conductivity, as it corresponds to a large phonon group velocity. Additionally, Young's modulus is found to be closely correlated with high phonon thermal conductivity and contribution. Our findings of simple factors that closely correlate with the electron and phonon thermal conductivity provide a general understanding of various metallic materials. They may facilitate the discovery of novel materials with extremely high or low thermal conductivity, or be used as descriptors in machine learning to accurately predict the thermal conductivity of metals in the future.

LC-MS/MS-based metabolic profiling: unraveling the impact of varying degrees of curing on metabolite transformations in tobacco.

The curing process regulates metabolite transformations of leaves and significantly influences the formation of tobacco quality. This study investigated the major physicochemical compositions and metabolic profiles under normal curing (NC), excessive curing (EC), and insufficient curing (IC) treatments. The results indicated that the contents of nicotine, nitrogen, potassium, and chlorine remained stable among treatments, while the sugar content in EC was significantly lower than in IC. LC-MS/MS identified 845 metabolites, with flavonoids as the most abundant class. Comparative analyses identified a series of differentially expressed metabolites (DEMs) among fresh leaf, NC, EC, and IC leaves at the end of 42°C, 54°C, and 68°C, respectively. At the end of 68°C, 256 up-regulated and 241 down-regulated common DEMs across treatments were isolated in comparison to fresh leaf, underscoring the consistency of metabolic changes during curing. Notably, nonivamide varied markedly across treatments, suggesting its potential as a key curing indicator. NC_68°C displayed 11 up-regulated and 17 down-regulated unique DEMs, differing from EC_68°C and IC_68°C, suggesting their potential availability in evaluating tobacco leaf quality. KEGG pathway analysis revealed temporal shifts in metabolic pathways, particularly those involved in secondary metabolite biosynthesis (such as flavonoids, flavones, flavonols) and amino acid metabolism, during the transition from yellowing to color-fixing. Correlation analysis isolated the top 25 DEMs correlated with curing degree and stage, which might play pivotal roles in the curing process and could serve as potential biomarkers for assessing curing degree and stage. Specifically, D-(+)-cellobiose displayed the strongest negative correlation with curing degree, while 5,7-dihydroxychromone exhibited the highest positive correlation coefficient. Furthermore, curcurbitacin IIa showed the highest positive correlation with curing stage, followed by hesperetin and 8-shogaol. Additionally, random forest analysis emphasized morellic acid as a core molecular metabolite across curing degrees, suggesting its potential as a biomarker. Debiased sparse partial correlation (DSPC) network analysis further pinpointed hispidulin as a key metabolite, underscoring its significance in elucidating flavonoid metabolism during the curing process. Collectively, this study enhances the understanding of metabolite transformations underlying tobacco curing processes and provides a valuable reference for optimizing curing strategies to achieve desired outcomes.

Real-time Actuator Fault Detection and Isolation for Quadrotor UAV via Directional Residuals

Abstract Fault diagnosis is critical for the safe and reliable operation of quadrotor unmanned aerial vehicles (UAVs), so that timely remedial measures can be taken to reduce its negative impact. This paper presents a real-time actuator fault detection and isolation (FDI) method for quadrotor UAV flight process. First, a linear parameter-varying (LPV) model is established to describe quadrotor UAV dynamics, which considers measurement noise and external disturbance. Then, an FDI strategy is developed based on directional residuals, in which only one observer-based residual generator is required and Η_/L∞ indices are incorporated to balance fault sensitivity and disturbance robustness. A threshold is derived from the L∞ performance condition, and actuator fault is detected through residual evaluation. Furthermore, by introducing fault feature vectors associated with the system model, the faulty actuator is isolated promptly by analyzing directional correlations between generated residuals and the defined fault feature vectors. Finally, based on a quadrotor UAV platform, the effectiveness and superiority of the proposed FDI method are verified through online trajectory tracking processes.

Economic Effects of Fertilizer Subsidy on Major Crops Productivity in Pakistan

Based on time series data set (1990-2022) this study was conducted to estimate the economic effects of fertilizer subsidies on major crops productivity in Pakistan. Majority (90%) of the farmers having small land holding size are not in a position to apply inputs like fertilizer which incurred 15-20% of total cost of production. Three types of analysis were employed i.e., Trend analysis, Correlation analysis and Regression analysis. The trends in growth rate of fertilizer use along with trends in growth rate of respective crop yield have been sketched with different trends. The correlation analysis between fertilizer subsidy and yield (kg ha-1) of major crops i.e. wheat, rice, sugarcane, cotton and maize has been calculated with positive correlation coefficient values as 0.459, 0.468, 0.351, 0.224 and 0.551 respectively. The simple linear regression analysis depicted that a rupee of one billion PKR subsidies is significantly increased the crop fertilizer usage (000 tons nutrients) of wheat (37.10), rice (14.97), sugarcane (13.60) and cotton (40.12) as well as increased the crop yield (mound acre-1) of wheat (0.26), rice (2.04), sugarcane (32.93), maize (62.17) and cotton (0.19) respectively which indicated that the yield of the crops is also positively affected by fertilizer use and fertilizer subsidy. The elasticity of yield with respect to fertilizer subsidy also confirmed the regression analysis results. Although yield is inelastic to subsidies; however, one % increase in fertilizer subsidy resulted in 0.043, 0.061, 0.044, 0.022 and 0.207 (%) increased in yield of wheat, rice, sugarcane, cotton and maize respectively. Based on positive values of coefficients, it is concluded that the fertilizer subsidies should be distributed more efficiently to enhance the productivity of crops.

Identification of Key Enzymes and Genes Modulating L-Ascorbic Acid Metabolism During Fruit Development of Lycium chinense by Integrating Metabolome, Transcriptome, and Physiological Analysis.

Lycium chinense is acknowledged for its substantial nutritional benefits, particularly attributed to the high levels of ascorbic acid (AsA) found in its fruits. The "Mengqi No.1" variety of L. chinense, which is cultivated in Qinghai, is known for its high yield and exceptional quality. We utilized the "Mengqi No.1" variety as experimental materials and combined metabolomic, transcriptomic, and physiological analyses to investigate the metabolites, genes, and enzymes related to AsA metabolism in L. chinense fruits. The results revealed nine differential metabolites associated with AsA metabolism in L. chinense fruits across three stages, including 1D-Myo-Inositol-1,4-Bisphosphate, D-Fructose, L-(+)-Arabinose, I-Inositol, L-Arabinitol, D-Galactose-1-P, lactose, α-D-Glucose, and D-Glucose-6-P. Notably, the contents of D-Glucose-6-P, D-Galactose-1-P, and D-Fructose were increased as the fruit developed. Additionally, fresh weight, longitudinal length, and radial width were increased, while the contents of AsA and DHA were decreased. GalDH and DHAR are critical enzymes for the accumulation of AsA and DHA, exhibiting positive correlation coefficient. Furthermore, PMM1, PMM5, GME2, and GME3 were identified as key regulatory genes in the L-Galactose pathway of AsA synthesis, influencing D-Galactose-1-P, D-Glucose-6-P, α-D-Glucose, and D-Fructose. DHAR1 and DHAR2 are considered key positive regulator genes of AsA and DHA in the AsA-GSH cycle. However, the majority of genes (nine) act as negative regulators of AsA and DHA. These findings provide a foundation for the understanding of the regulatory mechanism of AsA metabolism in L. chinense fruits and offer insights into the utilization of AsA from L. chinense.

Effects of Household Revenue Level Due to Rural Electrification on Growth of Small and Medium Enterprises (SMEs) in Coastal Region, Kenya

Rural electrification is a very important process to provide access to modern energy, especially to the poor people in developing countries like Kenya. Rural electrification programs in Kenya focus on providing development assistance through the supply of electricity services to stimulate economic productivity and enhance the quality of life in rural areas. These projects do not start with an assessment of the needs of the people that they are meant to serve. The rural electricity evaluation programs at present are confined to measuring only quantifiable variables, such as the number of households electrified. Moreover, the impact of electrification on rural SME operations is also seldom evaluated. The objective of this research study was to establish the effects of household revenue levels due to rural electrification on the growth of small and medium enterprises in the coastal region of Kenya. The study area was the Coast region. This study adopted an exploratory research design. The target population for this study comprised 172,556 small and medium enterprises (SMEs) registered in the coastal region by 2023. The study adopted multi-stage sampling, systematic and simple random sampling techniques due to the large target population involved. A total of 381 responses were received out of a target population of 399 respondents. This represented a 95.5% response rate from these study results. The majority of the respondents agreed that there was an extent of revenue level growth of small and medium enterprises (SMEs) in Kenya, and the majority of the respondents agreed that there was an extent of revenue level growth of small and medium enterprises (SMEs) in the coastal region, Kenya. The results show a strong positive correlation coefficient of 0.944, which is statistically significant (p&lt;0.05), showing that there is a significant effect of the revenue level of the household due to electrification on the growth of small and medium enterprises in the coastal region of Kenya. Further, the overall revenue level is positively affecting the growth of small and medium enterprises in the coastal region of Kenya. The study recommends that SMEs emphasize the use of machines as it enhances income due to improved quality products and services.

Household Skill Utilization, Rural-Electrification and Growth of Small and Medium Enterprises (SMEs)

According to the Government of Kenya (2004), the Micro and Small Enterprises (MSEs) sector generated over 90% (or roughly 500,000) of all new jobs created outside of agriculture in 2003, accounting for 30% of the country's GDP. The majority of Kenyans still live in rural areas, which also serve as the centre for micro and small businesses. In order to take advantage of this chance, Kenya has created a national policy through rural electrification programmes that aims to strengthen the capacities of micro and small businesses (Abdullah &amp; Markandyab, 2012). The objective of this research study was to establish the effects of household skills utilization due to rural electrification on the growth of small and medium enterprises in the coastal region of Kenya. The study area was the coastal region. This study adopted an exploratory research design. The target population for this study was small and medium enterprises (SMEs) registered in Kenya. Multi-stage sampling, systematic and simple random sampling techniques were applied, and the 95.5% response rate was 95.5%. This study found that there was an extent of revenue level on growth of small and medium enterprises (SMEs) in the coastal region of Kenya. Further, the study found that there is a strong positive correlation coefficient of 90.4% (0.904), which is statistically significant (p&lt;0.05), meaning that for every one unit of household skills utilization applied on SME's economic environment, there is a significant effect of household skills utilization due to electrification on the growth of small and medium enterprises in coastal region of Kenya. This also implies that household skills utilization is positively affecting the growth of small and medium enterprises in the coastal region of Kenya. The study recommends that SME stakeholders institute their economic operationalization more on household skill utilization since knowledge and skills acquired through electronic media are necessary for business record keeping.

Analysis on Family Business and Succession Planning in Hotel and Hospitality Sector in Uganda: A Case of White Horse Inn Kabale

Purpose: The study was set to examine the relationship between family business and succession planning in hotel and hospitality sector in Uganda, focusing on White Horse Inn Kabale as a case study. The study explored the strategies employed by leaders in family businesses for effective succession planning. Materials and Methods: The study used a mixed research design with quantitative and qualitative approaches to obtain in-depth information about family business and succession planning strategies in Uganda. Out of 150, a sample size of 108 (including 93 quantitative and 15 qualitative) was selected from different staff of White Horse Inn Kabale as the established family enterprise selected for the study (Krejcie &amp; Morgan, 1970). The tools used for data collection were questionnaires, an interview guide, and documentary checklist. Data was collected from the managerial and non-managerial staff of the White Horse Inn Kabale. Findings: The Pearson correlation coefficient r=.618, P&lt;0.05 indicates that there is a positive significant correlation coefficient between family business and succession planning. The model summary findings presents that Family Business, β=.618, t=7.666, p&lt;.005. This meant that a unit change in family business would lead to an increase in succession planning in White Horse Inn Kabale. The study findings reveals that the relationship between Family Business and Succession Planning was statistically significant, F=58.775, P&lt;0.05. This means that succession planning in a family business is a crucial process that ensures the long-term sustainability and success of the company. The results from regression model summary explain that family business caused a variation of 38.2% in succession planning. This indicates that succession planning in a family business is a crucial process that ensures the long-term sustainability and success. This therefore means that other factors not studied in this research contribute 61.8% of the succession planning. Implications to Theory, Practice and Policy: The study recommends that family business should formally document succession plans as an integral component of the business strategy, irrespective of the intentions regarding succession. Furthermore, fostering open and adaptable communication that promotes participatory decision-making is strongly recommended. A clear process for identifying essential competencies, along with a competency catalog, should be established to provide a solid foundation for business owners to evaluate potential successors, pinpoint competency deficiencies, and devise suitable plans for their development.

Research on Quantifying and Evaluating Tennis Match Momentum Based on Comprehensive Analytical Methods

Momentum is crucial in tennis matches, influencing player performance and match outcomes. However, quantifying and evaluating momentum has long been a challenge in sports science research. This study aims to quantify momentum in tennis matches by establishing a hierarchical analysis-based model for momentum flow. The model analyzes factors affecting momentum through five criteria: Service Level, Catch Level, Competition Result, Finishing Ability, and Winning Streak, with respective weights of approximately (0.1, 0.1, 0.2, 0.4, 0.2). Subsequently, the study assigns scores to these criteria based on different actions within a match. By multiplying the weights and scores, the momentum of each player is quantified, and the ratio of the two players' momentum provides a measure of momentum flow during the match. To assess the impact of momentum on match outcomes, the study employs k-means++ clustering analysis, violin plot analysis, and point-biserial correlation analysis. The point-biserial correlation analysis reveals a positive correlation coefficient of 0.66 between a player's momentum and their victory. Similar results are derived from the violin plot and clustering analysis. Therefore, it can be concluded that there is a significant association between the direction of momentum flow and a player's success in a match.

Assessment of Changes in Sensory Characteristics of Strawberries during 5-Day Storage through Correlation between Human Senses and Electronic Senses.

In the last decade, significant efforts have been made to predict sensory characteristics using electronic senses, such as the electronic nose (e-nose) and the electronic tongue (e-tongue), and discuss their relationship to the eating quality evaluated by human panels. This study was conducted (1) to characterize the aroma and taste profiles of strawberries over a 5-day storage period (4 °C) using both electronic senses and human panels and (2) to correlate the electronic sense data with human panel data. A total of 10 sensory attributes of strawberries, including 7 aroma and 3 taste attributes, were analyzed by a descriptive sensory panel (n = 16) over the five days. Although the human panel did not find significant differences in the intensities of the strawberry attributes over the five days, the intensity ratings showed an increasing or decreasing trend over the storage period. However, the e-nose and the e-tongue discriminated each of the storage days of the strawberry samples. Furthermore, the partial least square regression coefficients of determination (R2) indicated that the e-nose and the e-tongue were highly predictive in their evaluation of the intensities of all the descriptive sensory attributes. Lastly, the concentrations of furaneol, one of the key volatiles imparting a distinct ripe strawberry aroma, were determined using an e-nose to correlate with the intensities of aroma attributes evaluated by the panel. A significant positive Pearson's correlation coefficient was found with the intensities of overripe aroma. The findings indicate the potential of electronic senses to determine sensory characteristics and their excellent capability to predict the eating quality of strawberries.

The Effect of Menstrual Hygiene Management on Girl Child School Attendance at St Marys Girls Vocational School in Kamukuzi Division, Mbarara City

This study assessed the effects of menstrual hygiene management on school attendance among female adolescent students at St. Mary's Girls Vocational School in Kamukuzi Division, Mbarara City. The researchers employed systematic random sampling to select 45 respondents from Form One and Form Two, as these students were expected to have experienced their menstrual periods. The majority of the respondents were aged 13-14 years. While some girls used handkerchief cloths or hand towels as menstrual management materials, most of them used sanitary pads and disposed of them in the toilets. The researchers conducted a Pearson correlation coefficient analysis in SPSS to examine the relationship between menstrual hygiene management and school attendance. The analysis revealed a weak positive correlation coefficient of 0.210, indicating a weak relationship between menstrual hygiene management and school attendance. However, the p-value of 0.167 suggested that the results were not statistically significant. The study concluded that there is an impact of menstrual hygiene management on school absenteeism, as girls who experienced longer periods tended to miss more school days. However, the weak relationship and lack of statistical significance indicate that other factors may also contribute to school attendance among adolescent girls, and menstrual hygiene management alone may not be the sole determinant. This study provides valuable insights into the challenges faced by adolescent girls in managing menstruation and its potential impact on their school attendance. It highlights the need for comprehensive menstrual hygiene management education and support programs in schools to ensure that girls have access to appropriate materials and facilities. By addressing these challenges, schools can create a supportive environment that promotes regular attendance and educational opportunities for all female students, even during menstruation

The characteristics of V, Sc, Cr and Ni within the Cambrian terrigenous-carbonate deposits found in the Syuldyukar kimberlite field (Western Yakutia)

The investigation of the Syuldyukar kimberlite field, located within the Yakut diamond-bearing province, involved approximately 4,000 X-ray fluorescence (XFA) analyses and 150 inductively coupled plasma atomic emission spectroscopy (ICP AES) analyses on the host sedimentary rocks of the Upper Cambrian Holomolokha formation in proximity to the kimberlite bodies. The results indicated a disruption in the correlation ratios when compared to background concentrations, while subclark levels of vanadium (V), scandium (Sc), chromium (Cr), nickel (Ni), and other elements remained consistent. The elements were divided into three categories: typomorphic elements for kimberlites (Cr, Ni, Co), elements associated with carbonatites (barium (Ba), strontium (Sr), neodymium (Nd), zirconium (Zr)), and elements characteristic of basalts (V, Sc, zinc (Zn)). High positive correlation coefficients were established for the specified elements in the background concentrations. However, ICP analyses indicated significant decreases in the correlation between elements from different groups in the near-kimberlite space at the Syuldyukar site. X-ray diffraction (XRD) studies showed that in the compression areas, the correlation ratios of various elements were inconsistent when compared to the stretching areas. The analysis of the XRF and ICP data reveled that the average elemental concentrations in the background and near-tube space were nearly identical, except for some unusual hurricane values, with variations showing only slight changes. The positive correlation of several elements likely reflects background geological processes, including sedimentation in a marine basin and subsequent transformations such as hypergenesis, diagenesis, and catagenesis. The significant decrease in correlation coefficients, even with background concentrations remaining stable, is likely due to the redistribution of elements in the fluid resulting from phreatomagmatic explosions linked to the intrusion of kimberlites. Aqueous chloride fluids were observed to most actively redistribute elements in areas experiencing local tectonic compression. The identified changes in the correlation ratios of background elemental concentrations in sedimentary rocks containing kimberlite could act as a new indicator for locating hidden diamond-bearing kimberlites.

Predicting plateau atmospheric ozone concentrations by a machine learning approach: A case study of a typical city on the southwestern plateau of China

Atmospheric ozone (O3) has been placed on the priority control pollutant list in China's 14th Five-Year Plan. Due to their unique meteorological conditions, plateau regions contain high concentrations of atmospheric O3. However, traditional experimental methods for determining O3 concentrations using automatic monitoring stations cannot predict O3 trends. In this study, two machine learning models (a nonlinear auto-regressive model with external inputs (NARX) and a temporal convolution network (TCN)) were developed to predict O3 concentrations in a plateau area in the Kunming region by considering the effects of meteorological parameters, air quality parameters, and volatile organic compounds (VOCs). The plateau O3 prediction accuracy of the machine learning models was found to be much higher than those of numerical models that served as a comparison. The O3 values predicted by the machine learning models closely matched the actual monitoring data. The temporal distribution of plateau O3 displayed a high all-day peak from February to May. A correlation analysis between O3 concentrations and feature parameters demonstrated that humidity is the feature with the highest absolute correlation (−0.72), and was negatively correlated with O3 concentrations during all test periods. VOCs and temperatures were also found to have high positive correlation coefficients with O3 during periods of significant O3 pollution. After negating the effects of meteorological parameters, the predicted O3 concentrations decreased significantly, whereas they increased in the absence of NOx. Although individual VOCs were found to greatly affect the O3 concentration, the total VOC (TVOC) concentration had a relatively small effect. The proposed machine learning model was demonstrated to predict plateau O3 concentrations and distinguish how different features affect O3 variations.

Caprock Safety Evaluation Method in CCUS Based on Latin Hypercube Sampling: A case study of a block reservoir

Abstract CO2 geological sequestration is one of the essential means to achieve carbon neutrality goals. However, substantial CO2 sequestration in formations can lead to leakage issues, primarily through the caprock, involving caprock rupture, leakage along caprock fractures/faults, and capillary leakage. Therefore, establishing a method to assess the safety of the caprock during CO2 storage processes is crucial. Firstly, a numerical simulation model is constructed based on parameters from the target block to study the influences of reservoir property, development parameters, and caprock parameters on CO2 flooding, gas injection, and CO2 storage. Latin hypercube sampling is employed for scheme design and subsequent result analysis, applying Spearman’s method to analyze the controlling factors in each CO2 storage. Secondly, using continuous gas flooding as an example, the migration pattern of CO2 in the formation is investigated, and the influence of the formation pressure distribution on caprock safety is analyzed. Finally, considering the comprehensive impact of different parameters on caprock safety, a fuzzy comprehensive evaluation of caprock safety in the target block is conducted. The study indicates that caprock permeability is the most critical factor affecting safety operation across all storage stages, with respective highest positive correlation coefficients of 0.413, 0.356, and 0.221 in different stages. The migration of CO2 in the formation is primarily influenced by the distribution of injection wells and gas migration channels. The established quantitative evaluation standard for caprock safety in the target block calculates a suitability degree of 3.43, suggesting a relatively secure caprock in the block suitable for achieving long-term stable CO2 storage. This research provides theoretical support for the safety analysis of caprock in different stages of CO2 flooding and storage, offering a scientific basis for the safety operation of CCUS schemes.

Bivariate iterated Farlie–Gumbel–Morgenstern stress–strength reliability model for Rayleigh margins: Properties and estimation

In this paper, we propose bivariate iterated Farlie–Gumbel–Morgenstern (FGM) due to [Huang and Kotz (1984). Correlation structure in iterated Farlie-Gumbel-Morgenstern distributions. Biometrika 71(3), 633–636. https://doi.org/10.2307/2336577] with Rayleigh marginals. The dependence stress–strength reliability function is derived with its important reliability characteristics. Estimates of dependence reliability parameters are obtained. We analyse the effects of dependence parameters on the reliability function. We found that the upper bound of the positive correlation coefficient is attaining to 0.41 under a single iteration with Rayleigh marginals. A comprehensive comparison between classical FGM with iterated FGM copulas is graphically examined to assess the over or under estimation of reliability with respect to α and β. We propose a two-phase estimation procedure for estimating the reliability parameters. A Monte-Carlo simulation study is conducted to assess the finite sample behaviour of the proposed reliability estimators. Finally, the proposed estimators are examined and validated with real data sets.

Effect of unconventional waters irrigation on some morphological and physiological parameters of barley

A test on a variety of barley “Fouara” was carried out to verify the effects of treated wastewater on some physio-morphological parameters of this plant. Two different types of irrigation were chosen, one using treated wastewater from the Ain Beida wastewater treatment plant, and the other, ordinary water serving as a control. The physicochemical results of the treated wastewater showed, in particular, the EC, NH4, NO3 and the DCO/DB05 ratio do not exceed the admissible standards when they reach their maximum values The physio-morphological parameters of barley respond positively to the use of this water; represented by the two averages of the 'sugar' parameter which shows a clear difference depending on the water category (T and S) or the control individuals express an average (0.055) significantly lower than that of the S individuals (0.847). We note that significant values of the positive correlation coefficient of r=0.812 between the two parameters TRE and SF, therefore there is an association between these two factors. But negative for the TRE and PSF (r = -0.722). This means that the values of the two parameters do not evolve in the same direction. The factors 'sugar' and 'chlorophyll b' present the best correlation, they better represent the six individuals and the proline contents are higher in the treated plants.