Deterministic Factors Research Articles

Impact of ulcerative colitis therapy on the bacterial profile of the intestinal microbiota

Inflammatory bowel diseases represent a heterogeneous group of chronic diseases occurring as a result of disruption of interaction processes between the mucosal immune system and the colon commensal ecosystem. The key role of the intestinal microbiota in the pathogenesis of ulcerative colitis, as well as its definition as a deterministic factor influencing the status of immune activation and the severity of the disease, is confirmed in many studies. Accumulating evidence suggests that non-antibacterial drugs are able to modulate the composition of the intestinal microbiota, which in turn may determine the effectiveness of pharmacological therapy and the clinical outcome. The article presents a review of literature on the impact of drugs used in the treatment of ulcerative colitis on the bacterial community of the colon.

Forage lignocellulose is an important factor in driving the seasonal dynamics of rumen anaerobic fungi in grazing yak and cattle.

Anaerobic fungi (AF) inhabit the gastrointestinal tract of ruminants and play an important role in the degradation of fiber feed. However, limited knowledge is available on seasonal dynamics and inter-species differences in rumen AF community in yak and cattle under natural grazing systems. Using the random forests model, the null model, and structural equation model, we investigated the seasonal dynamics and key driving factors of fiber-associated rumen AF in grazing yak and cattle throughout the year on the Qinghai-Tibet Plateau (QTP). We found that the richness and diversity of rumen AF of grazing yak and cattle in cold season were significantly higher than those in warm season (P < 0.05). We identified 12 rumen AF genera, among which , Cyllamyces, and Orpinomyces were predominant in the rumen of both grazing yak and cattle. LEfSe and random forest analysis showed that Feramyces, Tahromyces, and Buwchfawromyces were important seasonal indicator of rumen AF in grazing yak (P < 0.05), and Caecomyces, Cyllamyces, and Piromyces in grazing cattle (P < 0.05). Null model analysis revealed that the dynamic changes of rumen AF community structure were mainly affected by deterministic factors. Notably, mantel test and structural equation model revealed that forage physical-chemical properties, including dry matter (DM), neutral detergent fiber (NDF), and hemicellulose contents (HC) were the key factors driving the seasonal variations of the rumen AF community (P < 0.05). The results revealed that forage lignocellulose was probably an important factor affecting the seasonal dynamics and inter-species differences of the rumen AF community under natural grazing conditions. IMPORTANCE The seasonal dynamics of rumen anaerobic fungi in nature grazing yak and cattle were determined during cold and warm seasons based on pasture nutritional quality and environmental data sets. The main driving factors of anaerobic fungi in yak and cattle rumen were explored by combining random forest and structural equation models. In addition, the dynamic differences in the composition of the anaerobic fungi community in the yak and cattle in different seasons were characterized. It was found that some rumen anaerobic fungi have contributed to high fiber degradation rate in yak. These novel findings improve our understanding of the association of environmental and dietary seasonal variations with anaerobic fungal community, facilitating yak adaptation to high altitude.

Disentangling the roles of chance, abiotic factors and biotic interactions among epiphytic bryophyte communities in a tropical rainforest (Yunnan, China).

Epiphytes offer an appealing framework to disentangle the contributions of chance, biotic and abiotic drivers of species distributions. In the context of the stress-gradient theory, we test the hypotheses that (i) deterministic (i.e., non-random) factors play an increasing role in communities from young to old trees, (ii) negative biotic interactions increase on older trees and towards the tree base, and (iii) positive interactions show the reverse pattern. Bryophyte species distributions and abiotic conditions were recorded on a 1.1 ha tropical rainforest canopy crane site. We analysed co-occurrence patterns in a niche modelling framework to disentangle the roles of chance, abiotic factors and putative biotic interactions among species pairs. 76% of species pairs resulted from chance. Abiotic factors explained 78% of non-randomly associated species pairs, and co-occurrences prevailed over non-coincidences in the remaining species pairs. Positive and negative interactions mostly involved species pairs from the same versus different communities (mosses versus liverworts) and life forms, respectively. There was an increase in randomly associated pairs from large to small trees. No increase in negative interactions from young to old trees or from the canopy to the base was observed. Our results suggest that epiphytic bryophyte community composition is primarily driven by environmental filtering, whose importance increases with niche complexity and diversity. Biotic interactions play a secondary role, with a very marginal contribution of competitive exclusion. Biotic interactions vary among communities (mosses versus liverworts) and life forms, facilitation prevailing among species from the same community and life form, and competition among species from different communities and life forms.

Comparison of the Efficiency of Overcoming the Crisis of Russian and Foreign Oil and Gas Companies

The purpose of the study was to evaluate the performance of large domestic and foreign oil and gas companies based on a factor analysis of the return on equity in the context of financial and economic crises. The relevance of the topic is due, on the one hand, to the leading role of the oil and gas industry in the Russian economy, and, on the other hand, to the need develop modern tools for the assessment and prediction of the performance of companies and comparison of the results of economic activity with those of foreign competitors. The object of the study was the financial performance of the largest domestic and foreign vertically integrated oil and gas companies. The subject of the study is the methods of deterministic factor analysis for assessing indicators in the oil and gas sector. The paper analyzes the main empirical indicators that reflect the degree of efficiency, justifies the choice of the profitability indicator of own assets as the main indicator for research in the oil and gas industry, analyzes approaches to assessing the contribution of various factors to the final efficiency. Methods of classification, decomposition, statistical, comparative and factor analysis were used. A five-factor DuPont decomposition of the return on equity was carried out, and the key factors affecting the efficiency of companies were identified: tax burden coefficient, percentage burden coefficient, return on sales, asset turnover ratio, financial leverage ratio. Using the LMDI‑1 model, the impact of changes in economic factors on changes in the efficiency of companies in 2013–2017 and 2018–2021 was assessed. It was concluded that domestic companies, on average, slightly outperformed foreign ones in terms of the considered efficiency indicator and coped better with the consequences of financial and economic crises in the periods under review. At the same time, domestic companies have a higher value of the tax burden coefficient with lower values of assets turnover and financial leverage.

Undrained stability of braced excavations in clay considering the nonstationary random field of undrained shear strength

The basal heave stability of supported excavations is an essential problem in geotechnical engineering. This paper considers the probabilistic analysis of basal heave stability of supported excavations with spatially random soils by employing the random adaptive finite element limit analysis and Monte Carlo simulations to simulate all possible outcomes under parametric uncertainty. The effect of soil strength variability is investigated for various parameters, including the width and depth of the excavation ratio, strength gradient factor, and vertical correlation length. Probabilistic basal stability results have also been employed to determine the probability of design failure for a practical range of deterministic factors of safety. Considering probabilistic failure analysis, the more complete failure patterns caused by the various vertical correlation length would decrease the probability of design failure. There are different tendencies between the probability of design failure at the same safety factor with various vertical correlation lengths. These results can be of great interest to engineering practitioners in the design process of excavation problems.

Exploring the correlation between HER2 alterations and 18F-FDG PET/CT metabolic parameters and their prognostic value in EGFR-negative non-small-cell lung cancer patients.

Our study intended to explore the correlation between HER2 alterations and 18F-FDG PET/CT metabolic parameters and their prognostic value in EGFR-negative non-small-cell lung cancer (NSCLC) patients detected by next-generation sequencing (NGS). NGS assay was performed in 1737 NSCLC patients, a total of 88 HER2 alterations and 176 negative HER2 with EGFR-negative patients were randomly selected for this study. When the HER2 status with EGFR-negative group was analyzed, multivariate analysis showed that smoking status, primary tumor SUVmax (pSUVmax) < 13.03 and stage were the independent deterministic factors of HER2 alterations. Multivariate cox regression analysis revealed that HER2 status, age, smoking status and stage were independent risk factors for overall survival (OS) in EGFR-negative NSCLC patients with different HER2 status. When the HER2 alterations group was separately analyzed, multivariate analysis demonstrated that low pSUVmax < 15.32 and histology were the independent deterministic factors of HER2 mutation. Multivariate cox regression analysis revealed that pSUVmax, smoking status, nodal involvement and treatment methods were independent risk factors for OS in EGFR-negative NSCLC patients with HER2 alterations. The study revealed that low pSUVmax was associated with HER2 alterations in EGFR-negative NSCLC patients, moreover HER2 mutation and HER2 amplification exhibited distinct 18F-FDG metabolic and clinical characteristics. Furthermore, it explored the prognostic value of HER2 alterations and 18F-FDG PET/CT metabolic parameters of pSUVmax in EGFR-negative NSCLC patients.

Efficiency and Reliability Assessment-Based Selection of the Optimal Common Bus in Hub-Stations

This paper is an attempt to present a simple yet innovative planning method for determining the type of common bus in a hub station (HS), devised on efficiency and reliability grounds. The efficiency is evaluated by modeling the efficiency curves of the converters under part-load and full-load conditions, hence enabling a realistic estimate of the efficiency. Reliability evaluation is executed by modeling the failure and repair rate distributions of the HS components. The optimal common bus type selection is based on both the efficiency and reliability metrics of the HS. The deterministic factor in the type of common bus selection is proved to be the number of components in the HS. The results indicate that DC and AC systems have comparable efficiencies with a meagre difference of 1.26%. The failure rate of AC common bus architecture is 22% greater than DC common bus architecture resulting in a 1.788 times reliability advantage of the DC system. Moreover, the greater number of components in the case of a AC common bus adds to the economic advantage of DC with a lower number of components leading DC to be an optimal design.

Anthropogenic original DOM is a critical factor affecting LNA bacterial community assembly

We investigated the geographical and environmental distance–decay relationships for both of the two bacteria in the Haihe River, Tianjin, China. HNA bacteria exhibited a stronger geographical variation-dependent pattern while LNA bacteria exhibited a stronger environmental variation-dependent pattern. Variance partition analysis (VPA), Mantel test, and partial mantel test validated the discrepant impacts of geographical distance and environmental factors on their two communities. The heterogeneous selection dominated community assembly of LNA bacteria demonstrates their greater sensitivity to environmental conditions. As the deterministic environmental factor, anthropogenic original dissolved organic matter (DOM) functions exclusively on LNA bacteria, and it is the critical factor leading to the discrepant biogeographical patterns of LNA and HNA bacteria. LNA bacteria interact with HNA bacteria and mediate the DOM driving total bacteria assembly. The LNA keystone taxa, Pseudomonas, Rheinheimera, Candidatus Aquiluna, and hgcl clade are capable to compete with HNA bacteria for anthropogenic original DOM, and are potential indicators of anthropogenic pollution. Our research reveals the non-negligible effect of the LNA bacteria in regulating the ecological response of total bacteria.

Deterministic processes have limited impacts on foliar fungal endophyte communities along a savanna-forest successional gradient

Patterns and drivers of succession provide insight into the mechanisms that govern community assembly, but remain poorly understood for microbial communities. We assess whether successional trends of trees are mirrored by foliar endophyte communities of three tree species across a deterministic woody successional gradient. Additionally, we test the relative contribution of abiotic predictors, biotic factors, and spatial distance between sites in predicting composition and richness of endophyte communities. Unlike the tree community, endophyte communities showed no consistent evidence of deterministic succession. Host identity was the most important factor structuring endophyte community composition; within hosts, spatial distance from the indigenous forest and between samples was important, while environmental predictors had small and inconsistent effects. Much variation in endophyte composition remained unexplained. In contrast, endophyte richness was well-explained by predictor variables. Host identity was most important in predicting endophyte richness, while the effect of other predictors on richness differed between host species. We conclude that deterministic succession in trees did not result in deterministic succession in endophyte communities; instead community assembly was most strongly influenced by host identity; while within hosts, neutral processes may be more important for endophyte assembly than deterministic factors.

C. C. Li and Quasi-Random Mating.

A simple model by which Hardy-Weinberg proportions are attained in a single generation while maintaining gene frequencies is stated and illustrated. The title 'Quasi-random mating' is proposed. Confusion about the Hardy-Weinberg principle can be avoided only if there is clear separation between the basic deterministic model and factors influencing a population's structure. Eighty years passed before C. C. Li coined the term 'pseudo-random mating'. The lesson taught by Li has not been taken on board.

Sample canonical correlation coefficients of high-dimensional random vectors with finite rank correlations

Consider two random vectors x˜=Az+C11∕2x∈Rp and y˜=Bz+C21∕2y∈Rq, where x∈Rp, y∈Rq and z∈Rr are independent random vectors with i.i.d. entries of zero mean and unit variance, C1 and C2 are p×p and q×q deterministic population covariance matrices, and A and B are p×r and q×r deterministic factor loading matrices. With n independent observations of x˜ and y˜, we study the sample canonical correlations between them. Under the sharp fourth moment condition on the entries of x, y and z, we prove the BBP transition for the sample canonical correlation coefficients (CCCs). More precisely, if a population CCC is below a threshold, then the corresponding sample CCC converges to the right edge of the bulk eigenvalue spectrum of the sample canonical correlation matrix and satisfies the famous Tracy-Widom law; if a population CCC is above the threshold, then the corresponding sample CCC converges to an outlier that is detached from the bulk eigenvalue spectrum. We prove our results in full generality, in the sense that they also hold for near-degenerate population CCCs and population CCCs that are close to the threshold.

Spatial distribution and assembly processes of bacterial communities in northern Florida freshwater springs

Freshwater microorganisms are an essential component of the global biogeochemical cycle and a significant contributory factor in water quality. Unraveling the mechanisms controlling microbial community spatial distribution is crucial for the assessment of water quality and health of aquatic ecosystems. This research provided a comprehensive analysis of microbial communities in Florida freshwater springs. The 16S rRNA gene sequencing and bioinformatics analyses revealed the bacterial compositional heterogeneity as well as numerous unique ASVs and biomarkers in different springs. Statistical analysis showed both geographic distance and environmental variables contributed to regional bacterial community variation, while nitrate was the dominant environmental stressor that shaped the bacterial communities. The phylogenetic bin-based null model characterized both deterministic and stochastic factors contributing to community assembly in Florida springs, with the majority of bins dominated by ecological drift. Mapping of predicted pathways to the MetaCyc database revealed the inconsistency between microbial taxonomic and functional profiles, implying the functional redundancy pattern. Collectively, our work sheds insights into the microbial spatial distribution, community assembly, and function traits in one of the world's most productive aquifers. Therefore, this work provides a unique view of the health of Florida's artesian springs and offers new perspectives for freshwater quality assessment and sustainable management.

Stability Analysis of Partially Saturated Soil Slope by Random Limit Equilibrium Method

Disregarding soil suction in computing the shear strength of unsaturated soils is widely used practice above the water table where the pore pressure is negative. Stability analysis was conducted using Rocscience Slide 2 software to evaluate matric suction contribution to the shear strength of the unsaturated soil in a slope in Hong Kong. The stability analysis resulted in a critical deterministic factor of safety for fully saturated soil and 1.2 when the matric suction is considered. Uncertainty in shear strength properties is considered by conducting multi scenarios probabilistic analysis. Lognormal distribution was assigned to the soil properties. The distribution was sampled 1000 times using Latin Hypercube method. A new sample was used to determine the safety factor in each simulation. Probability of failure (PF), mean safety factor (FSmean) and reliability index (RI) were determined in each scenario. It was shown that the most realistic results are obtained when cross correlation factors and correlation length (θ) are involved in the scenario. The study indicates that PF and RI are sensitive to a change in the correlation length less than 25 and less significant change beyond 25 m. The FSmean did not show noticeable fluctuation with the variation of correlation lengths.

Quantum and Component Analysis of P3a and P3b from Auditory Single Trial ERPs Differentiates Borderline Personality Disorder from Schizophrenia

Traditional approaches to EEG modelling use the methods of classical physics to reconstruct scalp potentials in terms of explicit physical models of cortical neuron ensembles. The principal difficulty with such approaches is that the multiplicity of cellular processes, with an intricate array of deterministic and random influencing factors, prevents the creation of consistent biophysical parameter sets. An original, empirically testable solution has been achieved in our previous studies by a radical departure from the deterministic equations of classical physics to the probabilistic reasoning of quantum mechanics. This crucial step relocates the models of elementary bioelectric sources of EEG signals from the cellular to the molecular level where ions are considered as elementary sources of electricity. The rationale is that, despite dramatic differences in cellular machineries, statistical factors governed by the rules of the central limit theorem produce the EEG waveform as a statistical aggregate of the synchronized activity of multiple microscale sources. Based on these innovations, we introduce a method of comprehensive computerized analysis of event related potentials directly from single trial recordings. This method provides a universal model of single trial ERP components in both frequency and time domains. For the first time, this tool provides effective quantification of all significant cognitive components in single trial ERPs and represents a viable alternative to the traditional method of averaging. We demonstrate the clinical significance of the additional information provided by the new method, using ERP data from patients with borderline personality disorder and schizophrenia. Referring to the P300 as an important objective marker of psychiatric disorders, we show that the new method reliably identifies P3a and P3b as the major components of the P3. The diagnostic significance of differentiating the P3a and P3b components of P3 is that it provides an objective electrophysiological measure that distinguishes borderline personality disorder from schizophrenia.

Regional economic growth and unemployment in the European Union – a spatio-temporal analysis at the NUTS-2 level (2013–2019)

The study aims to verify the relationship between the unemployment rate and economic growth in European Union (EU) regions. As the most important macroeconomic relationship, the significance of the dependence between the labour market situation and the output growth is widely known and considered. Analysis in this research was conducted using data for 229 EU regions on the NUTS-2 level in the years 2013–2019. In order to verify the relationship between the unemployment rate and the output growth, the spatio-temporal models for pooled time series and cross-sectional data (TSCS) were estimated. The Fitted Trend and Elasticity Method of verifying Okun’s law was used in the analysis, wherein the deterministic trend factor was enriched with the spatial element. Educational attainment as the additional explanatory variable was included in the models. The neighbourhood between regions was quantified based on two criteria: (1) common border criterion – related to the possibility of population migrations, and (2) similarity of the unemployment rate criterion – related to the imitation effect in the issue of introduced rules and regulations on the labour market by regional governments. One of the hypotheses verified in the investigation is the superiority of the economic neighbourhood over the geographical neighbourhood.

A dual-clustering algorithm for a robust medical grid partition problem considering patient referral

The medical grid including hospitals at all levels is a new hierarchical diagnosis and treatment system. It is assumed to provide health services for residents in a certain area, allowing free referral of patients, so as to effectively utilize medical resources. Therefore, from the perspective of the government, the key issue is how to divide the medical grid in a robust and balanced manner. In this paper, various deterministic factors, such as hospital level, location and department, as well as uncertain factors, including patient distribution or population density, are considered in decision-making. To solve this problem, a dual-clustering algorithm based on K-means and K-medoids (DCKK) is developed with local search methods to minimize the average patient waiting and travelling time. The experimental results show that DCKK algorithm can generate better and more robust grid partition solutions than the existing mainstream algorithms in different scenarios. In addition, the rules between the number of medical grids and the number of patients, as well as the hospital sharing between medical grids, are also studied. Finally, a real medical grid partition case of Ji'nan, China, with forty hospitals in four urban areas, is studied, and five medical grids are recommended.

Optical Properties of Boundary Layer Aerosols From High Spectral Resolution Lidar Measurements in a Polluted Urban Environment (Seoul, Korea)

AbstractContinuous measurements of aerosol extinction coefficient (σext) from the High Spectral Resolution Lidar (HSRL) in Seoul from 2016 to 2018 were used to investigate the diurnal variation of the aerosol optical depth (AOD). Nighttime AOD displayed a larger mean and standard deviation (0.45 ± 0.47) than daytime (0.40 ± 0.29). Hygroscopic growth of aerosols under humid conditions was a key factor in the relative enhancement of nighttime AOD. Taking advantage of the HSRL's vertically resolved measurements, the contribution of aerosols within the boundary layer (BL) and free troposphere (FT) to AOD and its temporal variation were investigated. Unlike the diurnal AOD variation, AOD within the BL (AODBL) showed similar diurnal variations with the mixing layer height (MLH), displaying lower nighttime values with a peak around 14–15 local standard time. However, the low correlation between MLH and AODBL (R2 = 0.06) implied that MLH was not the sole deterministic factor of AODBL. A larger AOD of FT aerosols (AODFT) was observed during spring due to frequent elevated dust layers. Using mean σext within the BL and surface PM10 concentrations, the mass extinction efficiency (MEE) of aerosols in Seoul was estimated. The PM10 MEE showed a mean of 5.40 g m−2 and displayed significant variability by PM2.5 to PM10 ratio, season, and ambient relative humidity. The uncertainty of estimated surface PM10 concentrations was minimized when the seasonality and humidity factor in MEE were taken into account (the normalized mean bias decreased from 10.6%, using a single MEE value, to 6.2%).

Coexistence of insect species in a phloem feeding guild: Deterministic and stochastic processes

Abstract1. Niche theory, neutral theory, and more recently the unifying theory of biodiversity offer alternative views of the structure (or not) of ecological communities. The relative importance of these theories has not been so thoroughly used to explain community assembly processes in phytophagous insects.2. We studied the mechanisms of community assembly in pine trees phloem feeders, exploring the relative contributions of deterministic and stochastic processes.3. Temporal and spatial partitioning of wood borers and bark beetles belonging to the pine phloem feeding gild, was assessed through flight traps and pine bolts extracted from felled live Pinus pinaster trees presenting evidence of decline/wilting.4. We found that deterministic factors explained most cases of coexistence between species, with partitioning in space and time reducing asymmetric competition for resources and intraguild predation, mediated by differences in size. However, in the case of very closely related species with minimum differences in size—in this case three species of Arhopalus—they occupied the same niche in space and time, suggesting that stochastic processes are more likely to maintain co‐occurrence.5. The present work indicates that both niche and stochastic processes contribute to the assembly of the phloem feeding community. This could be one more example of accordance with the unifying theory of biodiversity.

Reliability analysis of pile-reinforced slopes in width-limited failure mode considering three-dimensional spatial variation of soil strength

Stabilization pile is a common measurement for landslide mitigation. In previous literatures, the deterministic safety factor Fs method has been well established for pile-reinforced slope stability analysis, for example by limit analysis. However, the Fs method by itself cannot reflect the inherent uncertainty and spatial variability of mechanical properties of soil. This paper presents a probabilistic analysis procedure for width-constrained pile-reinforced slope where the failure pattern and soil spatial variability are both accounted for under three-dimensional (3D) condition. A modified discretization kinematic analysis-based mechanism is employed as the deterministic model. The spatial variability of cohesion c and friction angle φ is modeled as lognormal random fields by using the Karhunen–Loève expansion. The sparse polynomial chaos expansion (SPCE) is used to construct the meta-model to reduce the computational cost in high dimensional stochastic problems. The failure probability, probability density function (PDF), and other useful reliability results can be provided by performing Monte Carlo simulations of the proposed SPCE meta-model. Finally, the influences of soil spatial variability, slope geometry, and pile parameters on the slope reliability are analyzed. The combination of the modified discretization mechanism and SPCE provides a useful tool for the probabilistic analysis of pile-reinforced earth slopes under 3D condition. The probabilistic simulation results are also helpful for reliability design of pile-reinforced slope in practice.

Free Fall Detection in UAV Missions

This research paper addresses the designing of high speed free fall detection and primary trigger generation problem as a part of an in-flight emergency technology developments for unmanned aerial vehicles. The primary trigger is the very first to be detected and to be generated with high speed and accuracy in designing protection mechanism. This trigger indicates that UAV started falling. Sequences of resulting mechanism such as airbag inflation comes secondly. Speed requirement is a deterministic factor when the flight altitude is low. In this paper a high speed analog module is proposed to achieve the primary trigger and performed relevant validation tests on linear free fall and rotational free fall which covers the majority of free fall patterns. The positive test results verify the design as a primary trigger generation module for linear and rotational free fall detection in low altitude UAV missions or which could be enhanced with additional features to form more complex system of airbag inflation in UAV in-flight emergency technology development.