Degree Of Disturbance Research Articles

Moderating Role of Coping Strategies in Relationship between Household Chaos and Mental Health

Background. Household chaos is identified with mental well-being as the level of chaos promptly affecting the mental health of adolescents. A chaotic home situation is portrayed as when there is an elevated degree of disturbances, noise and crowd, instability, and an absence of a schedule that may add to levels of stress in a home environment (Bronfenbrenner & Evans, 2002). Adolescence is said to be a vulnerable period in which an individual is involved in physical and psychosocial changes (WHO, 2004). Coping strategies are the mechanism used by an individual to cope with stressful events (Folkman, 1984). Problem-focused coping strategy with reference to mental health focuses on problem solving. Emotion-focused coping helps to regulate emotions and dysfunctional coping tries to avoid stressful situations (Tolor & Fehon, 1987). The objective of this study was to examine the role of coping strategies in a relationship with household chaos and the mental health of adolescents. Method. The sample was consisted of 200 adolescents (52% girls, 48% boys) between the ages of 10 and 19. The correlational research method was used to assess the relationship among variables. The convenient sampling technique was used to collect the data. Confusion, Hubbub and Order scale (Mathen et al., 1995), Mental Health Inventory (Ware & Veit, 1983), and Brief Cope scale (Carver, 1997) were used to measure the study variables. Results. The correlational analysis revealed a significant negative correlation between household chaos and mental health. Findings showed that household chaos negatively predicted psychological wellbeing and positively predicted psychological distress while, coping strategies was positively linked with mental health. Findings further indicated that coping strategies buffered the relationship between household chaos and mental health. Conclusion. Adolescents with high levels of chaos at home, suffer from mental health problems. In the presence of coping strategies, the effect of household chaos on mental health decreases.

Assessment of the membrane potential of mitochondria in immunocompetent blood cells of children with asthma, depending on controllability of the course of the disease

Aim. To study the functional state of immunocompetent blood cells by assessing the membrane potential of mitochondria (MPM) in bronchial asthma in children, depending on the controllability of the course of the disease.Materials and methods. 167 children suffering from asthma aged from 1 to 17 years were examined, two groups were formed: 1 - controlled course of asthma (n=70), 2 - partially controlled and uncontrolled course of asthma (n=97). The functional and energetic status of immunocompetent blood cells was assessed by flow cytometry with determination of MPM using JC-1 dye.Results. The proportion of cells with reduced MPM in children with asthma in comparison with conditionally healthy children is higher in all pools - lymphocytes (46.1% vs. 34.0%), monocytes (12.0% vs. 9.0%), gran­ulocytes (11.3% vs. 7.0%). A higher percentage of cells with reduced MPM was found in the pools of monocytes (15.4% vs. 8.8%) and granulocytes (13.8% vs. 6.7%) with uncontrolled asthma. “Method for a comprehensive assessment of the energy security of immunocompetent blood cells” has been developed and patented. According to this method, the degrees of energy deficiency are relevant to the control of the course of asthma: in group 1, there is no energy deficit in 12.9% of cases, the first degree of deficiency in 40%, the second in 20%, the third in 27.1%; in the second group - 11,3%, 15,5%, 42,2%, 31,0% accordingly.Conclusion. The use of the developed method for a comprehensive assessment of the energy security of immunocompetent blood cells as an additional method to the approved medical standards, technically performed in a short time and with high accuracy, makes it possible to conduct early preclinical diagnostics of energy-deficient con­ditions of immunocompetent blood cells in asthma; according to the degree of disturbances detected, it is reasonable to determine the choice, the amount of necessary therapy and evaluate the effectiveness of treatment.

Nematodos como bioindicadores para evaluar el estado edáfico de un área de Selva Baja Caducifolia en el estado de Guerrero, México

The Low Deciduous Forest (LDF) provides several ecosystem services; however, it is the type of vegetation with the greatest anthropogenic impact. Sampling was carried out at 7 sites in an LDF area in recovery, located in the Costa Chica region, in the Guerrero State, Mexico. The main objective was to evaluate the degree of soil disturbance from the analysis of the composition and structure of communities of nematodes present in each of the sites. Bacterivorous nematodes considered as opportunistic organisms were the most abundant in all sites, indicating disturbed soils. The average values of the ecological indices (Maturity Index - IM, Enrichment Index - IE, and Structure Index - SI) were low in most of the sites, confirming the results obtained with the trophic groups.

Preclinical studies in support of phase I/II clinical trials to treat GUCY2D-associated Leber congenital amaurosis

Mutations in GUCY2D are associated with severe early-onset retinal dystrophy, Leber congenital amaurosis type 1 (LCA1), a leading cause of blindness in children. Despite a high degree of visual disturbance stemming from photoreceptor dysfunction, patients with LCA1 largely retain normal photoreceptor structure, suggesting that they are good candidates for gene replacement therapy. The purpose of this study was to conduct the preclinical and IND-enabling experiments required to support clinical application of AAV5-hGRK1-GUCY2D in patients harboring biallelic recessive mutations in GUCY2D. Preclinical studies were conducted in mice to evaluate the effect of vector manufacturing platforms and transgene species on the therapeutic response. Dose-ranging studies were conducted in cynomolgus monkeys to establish the minimum dose required for efficient photoreceptor transduction. Good laboratory practice (GLP) studies evaluated systemic biodistribution in rats and toxicology in non-human primates (NHPs). These results expanded our knowledge of dose response for an AAV5-vectored transgene under control of the human rhodopsin kinase (hGRK1) promoter in NHPs with respect to photoreceptor transduction and safety and, in combination with the rat biodistribution and mouse efficacy studies, informed the design of a first-in-human clinical study in patients with LCA1.

Chytrid prevalence and infection intensity in treefrogs from three environments with different degrees of conservation in Mexico

AbstractChytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has been related to rapid population declines and extinction in amphibians around the world. Bd has been associated with a severe decline in amphibian populations in southern Mexico. We compare the prevalence and intensity of Bd infection in two tree frogs in southern Mexico with similar life habits (Plectrohyla matudai and Ptychohyla euthysanota), inquiring if they differ across habitat types with different degrees of disturbance: preserved cloud forest, secondary cloud forest and anthropized riparian vegetation, and across three seasons. We examine the relationship between infection prevalence and intensity with biotic and abiotic variables. Infection prevalence differed between the two species, but not among environments, despite their similar life habits. Among seasons, prevalence decreased significantly at the end of the rainy season. There was no indication of significant changes in infection intensity between species, environments, and seasons. Moreover, the interaction among extrinsic factors (canopy cover, temperature, relative humidity) and factors intrinsic factors (body condition) explains the dynamics of Bd infection in the region. In our sample, we found no disease‐affected individuals, which may indicate that both species are resistant to the effects of the pathogen under field conditions. Finally, our results found no evidence to indicate that open canopies and anthropized habitats of the Sierra Madre de Chiapas are a refuge that prevents high prevalence or infection of Bd in stream breeders' amphibians.Abstract in Spanish is available with online material.

Experimental investigation on strength-weakening effect and fracture behavior of red sandstone under coupled static and dynamic cyclic loadings

Underground rock masses are often exposed to dynamic disturbances due to seismic waves and blasting excavation disturbances, resulting in significant changes in their physical and mechanical properties. To reveal the strength-weakening effect of rock under the coupled stress, the Brazilian disc tests of red sandstone were carried out by coupling pre-static and dynamic disturbing. The impacts of preloading, loading wave amplitude, dynamic disturbance frequency, and cycle number were studied on the weakening of Brazilian disc splitting strength. Furthermore, the fracture behaviors were characterized and discussed from the fracture morphology and fractal dimension. The results show that the loss ratios are positive under dynamic disturbance loading, indicating that the Brazilian splitting strength is weakened. For the same load wave amplitude, the loss of strength and P-wave velocity under 70 % preloading is more than twice that under 55 % preloading. At high preloading, the maximum strength loss and wave velocity losses are 13.7 % and 19.2 %, respectively. Comparing the disturbance degree of the sample with the increase of frequency by 1 Hz, cycle number by one time, and load wave amplitude by 1 % PS, it is concluded that the decline of wave velocity for the rock sample with the increase by 1 % PS in load wave amplitude is the largest, followed by the frequency and cycle. Only micro-cracks appear on the fracture surface under pure static loading. However, when the dynamic load disturbance is applied, the cement wrapped with debris falls off, besides micro-cracks. And with the increase of amplitude, the area of bare debris also progressively intensifies. Meanwhile, the width and number of micro-cracks gradually increased, with the broadest micro-crack reaching 18.2 μm. Preloading, loading wave amplitude, loading frequency, and cycles are positively correlated with fractal dimension D. The higher the D value, the more broken the sample.

Genetic variability of earthworm populations in soils with different perturbation levels

Density and genetic variability of both soil macro- and meso-fauna are disturbed by productive practices. This study aimed to analyze the genetic diversity and genetic structure of populations of the earthworm Aporrectodea caliginosa caliginosa (Briones, 1996) in two sites of the Argentine Pampa under different levels of disturbance: i) grassland, ii) livestock-raising plot, iii) agricultural-livestock raising plots and iv) agricultural plot (the most disturbed). The genetic diversity of the earthworm population was determined based on the allele number, polymorphism percentage and Similarity Index. Allele number and polymorphism percentage were lower in populations from one of the soils under agricultural-livestock practices, but differed significantly only from the values of the other agricultural-livestock raising plot and the livestock-raising plot. Population structure was low although significant. This study shows that allele number and polymorphism are very useful metrics to provide historical and functional information of soils. However, the genetic differences here recorded probably depend on multiple historical and recent causes. The stability of environmental conditions along with the degree of disturbance must be considered to understand their impact on population genetic structure.

Clonal functional traits favor the invasive success of alien plants into native communities.

Functional traits are frequently proposed to determine the invasiveness of alien species. However, few empirical studies have directly manipulated functional traits and tested their importance in the invasion success of alien species into native plant communities, particularly under global change. We manipulated clonal integration (a key clonal functional trait) of four alien clonal plants by severing inter-ramet connections or keeping them intact and simulated their invasion into native plant communities with two levels of species diversity, population density and nutrient availability. High community diversity and density impeded the invasion success of the alien clonal plants. Clonal integration of the alien plants promoted their invasion success, particularly in the low-density communities associated with low species diversity or nutrient addition, which resulted in a negative correlation between the performance of alien plants and native communities, as expected under global change. Thus, clonal integration can favor the invasion success of alien clonal plants into degraded resident communities with a high degree of disturbance and eutrophication. Our findings confirm the role of clonal functional traits in facilitating alien plant invasions into native plant communities and suggest that clonal functional traits should be considered to efficiently restore degraded communities heavily invaded by alien clonal plants.

Daylight ultraviolet B radiation ruptured the cell membrane, promoted nucleotide metabolism and inhibited energy metabolism in the plasma of Pacific oyster

The increasing and intensifying ultraviolet B (UVB) radiation in sunlight is an environmental threat to aquatic ecosystems, potentially affecting the entire life cycle of wild or aquacultural Pacific oyster Crassostrea gigas with photoreception. Due to its complex composition, plasma is an important biological specimen for investigating the degree of disturbance from its steady state caused by the external environment in the open-pipe-type hemolymph of mollusks. We performed a multi-omic analysis of C. gigas plasma exposed to daylight UVB radiation. Hub differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) were identified using the functional classification of Clusters of Orthologous Groups of proteins (COGs) through the protein-protein interaction (PPI)-based maximal clique centrality (MCC) algorithm. Our results summarize three types of UVB influences (disruption of the cell membrane, promotion of nucleotide metabolism, and inhibition of energy metabolism) on C. gigas based on transcriptomic, proteomic, and metabolomic analyses. The associated hub DEGs, DEPs (e.g., nucleoside diphosphate kinase, malate dehydrogenase, and hydroxyacyl-coenzyme A dehydrogenase), and metabolites (e.g., uridine, adenine, deoxyguanosine, guanosine, and xylitol) in the plasma were identified as biomarkers of mollusk response to UVB radiation, and could be used to evaluate the influence of environmental UVB on mollusks in future studies.

Fish Community Structure and Biomass Particle-Size Spectrum in the Upper Reaches of the Jinsha River (China)

To understand the characteristics of the fish community structure and biomass particle-size spectrum in the upper reaches of the Jinsha River, fish and environmental surveys were conducted in 21 segments of the upper reaches of the Jinsha River in September 2019 and June 2020. A total of 4062 fish belonging to 2 orders, 5 families, 18 genera, and 28 species were collected. Among them, Cyprinidae fish were the most abundant (14 species), accounting for 50.00%. The Shannon index and Pielou evenness index values varied from 0.402-1.770 and 0.254-0.680, respectively. The dominant species of fish were Triplophysa stenura, Schizothorax wangchiachii, and Schizopygopsis malacanthus. Redundancy analysis (RDA) was used to analyse the relationship between the fish community and environmental factors. Velocity, altitude, and dissolved oxygen were the main influencing factors of fish community structure differences in the upper reaches of the Jinsha River. The abundance/biomass curves showed that the fish communities in the upper reaches of the Jinsha River were moderately or severely disturbed. The standardized biomass particle-size spectrum of fish showed that the degree of disturbance of fish in tributaries was much lower than that in the main stream. Compared with the historical data, the fish community structure in the Jinsha River has changed significantly, with the number of exotic species increasing, and the individual fish showing miniaturization and younger ages. It is suggested that habitat conservation strategies be adopted in the upper tributaries of the Jinsha River to provide a reference for the restoration of fishery resources and the conservation of fish diversity in the Yangtze River.

Rock Mass Parameters For The Brisbane CBD

Rock mass parameters are presented for the typical range of rock conditions encountered in the Brisbane CBD and surrounding area. Rock mass units are classified based on lithology, weathering, intact rock strength and degree of disturbance. The rock mass parameters are based on the Author’s combined experience from Brisbane infrastructure projects including the M7 Clem Jones Tunnel, Airport Link and Cross River Rail. The parameters may be useful for design and construction of future ground engineering projects in Brisbane.

Using POI and time series Landsat data to identify and rebuilt surface mining, vegetation disturbance and land reclamation process based on Google Earth Engine

The development of coal resources is necessary, but it has a huge negative impact on land, ecology, and the environment. With the increasing awareness of environmental protection and the requirements of related regulations, the design and practice of reclamation projects run through the mining life cycle and continue for a long time after the coal production. High-precision monitoring of mining disturbance and reclamation, quantifying the degree and time of vegetation disturbance and restoration, is of great significance to minimize the environmental effect of mining. Remote sensing, widely used as efficient monitoring tool, but there is not enough research on disturbance and reclamation monitoring taking into account large-scale areas and high temporal and spatial accuracy. Especially when mining sites remain unknown, how to distinguish the disturbance of coal mining and other human activities affecting the surface land cover has become a challenge. Therefore, this paper proposed a method to reconstruct the time series of mining disturbance and reclamation in a large area by using the POI (point of interest) and Landsat time series images using multiple buffer analysis methods. The process includes: (1) Retrieval of POI in the study area based on the public mining list using Python crawler, and buffering 100 km for preliminary extraction of potential mining areas; (2) Using spectral index mask and random forest algorithm to accurately extract the exposed coal on the Google Earth Engine (GEE) platform; (3) Buffering 10 km to identify the occurrence of disturbance and reclamation, using pixel-based temporal trajectory identification of LandTrendr algorithm under GEE. The method successful detect the change points of surface coal mining disturbance and reclamation in eastern Inner Mongolia of China. The results show that: (1) The method can effectively identify the extent of surface coal mining disturbance and reclamation, and the overall extraction accuracy is 81%. (2) Surface coal mining disturbance in eastern Inner Mongolia was concentrated in 2006–2011. By 2020, the total disturbed area is 627.8 km2, with an average annual disturbance of 18.5 km2, and the annual maximum disturbance to the ground reached 64.6 km2 in 2008. With the total reclaimed area being 236.3 km2, the reclamation rate is about 37.6%. This study provides a systematic solution and process for monitoring the disturbance and reclamation of surface coal mining in a large range with little known about the mines’ location. It can effectively identify the mining disturbance and reclamation process which can also be extended to other areas, providing a quantitative assessment of mining disturbance and reclamation, which can support further ecological restoration decision-making.

PERIOPERATIVE METABOLISM OF PATIENTS WITH ESOPHAGEAL HERNIA OF THE DIAPHRAGM

Summary: Premedication – medical and non-medical preparation of the patient for surgery or examination, which will take place with The study of perioperative changes in metabolism in patients undergoing laparoscopic surgical interventions for esophageal hiatal hernia (EHH) is relevant. The aim of the study. To study the perioperative metabolism in patients with EHH and evaluate the possibilities of its correction. Material and methods. The study was prospective, not randomized. 127 patients, aged 31-76 years, who underwent laparoscopic operations in connection with EHH, were studied (m-59, w-68). Preoperative risk ASA II-III. General anesthesia using the inhaled anesthetic sevoflurane and the narcotic analgesic fentanyl in conditions of low-flow artificial lung ventilation. Perioperative intensive care was carried out in accordance with the International Standards of Safe Anesthesiological Practice of the WFSA (World Federation of Societies of Anesthesiologists, 2010). In group I (n=61), a retrospective energy audit was carried out according to protocols for analgesia of medical charts and calculations of indirect calorimetry with determination of current metabolism (CM) and basal metabolism (BM). In group II (n=66), operational monitoring was supplemented with the use of indirect calorimetry with the determination of CM, BM, target metabolism (TM) and the degree of metabolic disturbance (DMD = 100×(TM-CM) / TM) %, and intensive therapy was supplemented additional infusion therapy and glucocorticoids, accordingly to the dynamics of metabolic changes. The results. The initial indicators of metabolism, in both groups, were without disturbance and significantly exceeded the basal level (in group I – by 30.5%, in group II – by 28.8%) and had the following values: in group I – 749±12 cal× min-1×m-2, in group II – 756±13 cal×min-1×m-2. In both groups, at the stage of reverse Trendelenburg position, imposition of pneumoperitoneum and the beginning of the operation, there were significant metabolic disturbances with a decrease to the basal level. In patients of group I, a slow recovery of PM was observed, the value of which at the moment of awakening remained 7.6% lower than the initial one (p<0.05). In patients of group II, against the background of increased infusion therapy and administration of glucocorticoids, PM recovery was more intense, and, at the moment of awakening, its value exceeded the corresponding value of group I by 10.4% (р<0.05). At the same time, CM and SPM were not high and did not differ from the initial values. Patients of group II, compared to group I, woke up faster and were transferred to the ward, and nausea and vomiting were 2.7 times less frequent: 7.35% in group II and 19.7% in group I (p<0, 05). After 6 and 12 hours after waking up, the feeling of pain on the VAS scale in group II was lower than in group I, respectively, by 24.3% and 34.4% (p < 0.05). Conclusions. Perioperative energy monitoring makes it safer to perform laparoscopic surgery in patients with EHH. Additional definition of the target metabolism and the degree of metabolic disturbance allows more effective construction of perioperative intensive therapy

General Modelling Method for the Active Distribution Network with Multiple Types of Renewable Distributed Generations

With a proliferation of diverse types of renewable distributed generation (DG) into the distribution network, an equivalent model of an active distribution network (ADN) is extremely important, since the detailed modeling of the whole ADN is much more complex and time consuming. However, different studies developed different model structures of ADNs, which are difficult to be applied in a power system simulation. At the same time, the DG’s low voltage ride through the (LVRT) control was not considered in the existing ADN model, which may lead to a large modelling error. In this paper, a general equivalent model is developed for the ADN with a significant amount of DGs, based on a two-step modelling method. Step one, motivated by the dynamic similarities between the doubly-fed induction generator (DFIG)-based wind turbines, direct drive permanent magnet synchronous generator (DDPMSG)-based wind turbines, and photovoltaic (PV) generation, a general model structure of a renewable DG is initially developed. Then, an aggregation method for the DG’s nonlinear subsystems of the low voltage ride through (LVRT) control and the converter’s current limits are presented. Step two, the ADN model is represented by a general renewable DG model paralleled with a composite load model, and the model is validated, based on an actual distribution network with different renewable DG penetrations and different disturbance degrees. The simulation results show that our model outperforms others with acceptable errors.

Validation of Relationship between Patients' Descriptions of Pruritus and Patient-burden of Chronic Pruritus using Structural Equation Modelling.

Patients with chronic itch describe their pruritus in a wide variety of ways. However, these subjective descriptions are often not taken into consideration by physicians. This study aimed to validate patients' descriptions of pruritus, and to investigate the relationship between various descriptions of pruritus and the patient burden of chronic pruritus by examining the mediating effects of sleep disturbance and sexual dysfunction on patient's quality of life, as predicted by various descriptions of pruritus. Exploratory and confirmatory factor analyses were performed to identify the factor structure measured by 11 descriptions of pruritus. The study then analysed differences in the degree of sleep disturbance, sexual dysfunction, and quality of life deterioration factors using a structural equation modelling method. Using data from 419 patients with chronic pruritus, 11 descriptions of pruritus were classified into 2 groups: (i) sensory pruritus (i.e. stinging, stabbing, burning, painful, formication, throbbing, and cold) that are linked with descriptions of pruritus patterns; and (ii) affective pruritus (i.e. annoying, unbearable, worrisome, and warm) from patient reports of psychological or emotionaldistress. The study found that affective pruritus decreases patient's quality of life either directly or indirectly through sleep disturbance. In conclusion, clues about a patients' sleep disturbance or poor quality of life can be obtained through their descriptions of pruritus.

Numerical simulation of roadway deformation and failure under different degrees of dynamic disturbance

Deformation and failure of the roadway surrounding rock under dynamic disturbance were explored, which is essential for the control of the surrounding rock. The impact of dynamic disturbance on the deformation and failure of the roadway surrounding rock was studied from a single factor perspective using numerical simulation software. The disturbance intensity, frequency, and time were determined to affect the deformation and plastic zone of the surrounding rock. Firstly, a multi-factor integrated study was achieved using an orthogonal experimental design, and the impact of the three factors on the deformation and plastic zone of the surrounding rock were studied by applying mean value and extreme difference. The results show that the degree of influence of deformation of the roof is time > intensity > frequency in order. The impact of the plastic zone volume is intensity > frequency > time in order. Finally, a multivariate regression model was established using multiple regression analysis. The P = 0 < 0.05 for the regression model is obtained by variance analysis, and the equation regression is significant, which can effectively predict the deformation and failure of the surrounding rock under dynamic disturbance.

Baseflow Persistence and Magnitude in Oil Palm, Logged and Primary Tropical Rainforest Catchments in Malaysian Borneo: Implications for Water Management under Climate Change

While timber harvesting has plateaued, repeat-logging and conversion into plantations (especially oil palm) are still active in the tropics. The associated hydrological impacts especially pertaining to enhanced runoff, flood, and erosion have been well-studied, but little attention has been given to water resource availability in the humid tropics. In the light of the increasing climate extremes, this paper compared baseflow values and baseflow recession constants (K) between headwater catchments of five differing land-uses in Sabah, Malaysian Borneo, namely primary forest (PF), old growth/virgin jungle reserve (VJR), twice-logged forest with 22 years regeneration (LF2), multiple-logged forest with 8 years regeneration (LF3), and oil palm plantation (OP). Hydrological and meteorological sensors and dataloggers were established in each catchment. Daily discharge was used for computing K via four estimation methods. Catchment ranks in terms of decreasing K were VJR (0.97841), LF3 (0.96692), LF2 (0.90347), PF (0.83886), and OP (0.86756). Catchment ranks in terms of decreasing annual baseflow were PF (1877 mm), LF3 (1265 mm), LF2 (812 mm), VJR (753 mm), and OP (367 mm), corresponding to 68%, 55%, 51%, 42%, and 38% of annual streamflow, respectively. Despite the low K, PF had the highest baseflow magnitude. OP had the fastest baseflow recession and lowest baseflow magnitude. Baseflow persistence decreased with increasing degree of disturbance. K showed strong association to catchment stem density instead of basal area. For dynamic catchments in this study, the Kb3 estimator is recommended based on its lowest combination of coefficient of variation (CoV) and root mean squared error (RMSE) of prediction. For wetter catchments with even shorter recession events, the Kb4 estimator may be considered. Regarding climate change, logging and oil palm agriculture should only be conducted after considering water resource availability. Forests (even degraded ones) should be conserved as much as possible in the headwaters for sustainable water resource.

Life in a Contaminated Environment: How Soil Nematodes Can Indicate Long-Term Heavy-Metal Pollution.

We investigated the genera, trophic groups, and functional guilds of soil nematodes at five alluvial meadows along the Litavka River in the Czech Republic to assess their usefulness as indicators of heavy metal pollution in soils. The Litavka River flows around the waste-sedimentation pond of a smelter in the city of Příbram in the Central Bohemian Region. Lead, zinc, and arsenic are the main pollutants in the soils in the vicinity of the smelter. The alluvial meadows closest to the pond and mine waste were the most heavily polluted sites, and contamination decreased downstream along the river with increasing distance from the sources of pollution. The nematode communities were sensitive to pollution, with the most contaminated sites having considerably fewer nematode individuals, fewer genera, and a less diverse and more degraded food web with less nematode biomass. Arsenic, lead, and zinc contents were significantly negatively correlated with the numbers of bacterivores, predators, omnivores, plant parasites, and fungivores, which were significantly less abundant at highly polluted sites. This correlation suggests that nematode groups with higher c-p values, and those with c-p 1 and 2 designations, can be useful indicators of high heavy-metal contamination in areas polluted for a long time. In contrast, the abundance of c-p 3 plant parasitic nematodes was positively correlated with copper, nickel, and zinc contents and with soil-moisture content in the alluvial meadows. Maturity index (MI) and MI2-5 were the most sensitive indices of the degree of disturbance of the soil ecosystem, with enrichment index, structure index, and basal index indicating the altered decomposition channels and diminished structure of the food web.

Effect of disturbance on the progressive failure process of Eastern Himalayan Gneiss

Disturbance induced by stress relief has a significant effect on the laboratory properties of rocks in high in situ stress regions. A better understanding of its mechanism can help evaluate rock properties in regions such as the Tibetan Plateau. In this study, the progressive failure process of gneiss with high disturbance in the eastern Himalayas was explored using triaxial tests, acoustic emission minoring, X-ray computerised tomography (CT), and three-dimensional reconstruction. We established a grading standard to evaluate the impact of disturbances on the mechanical properties of Eastern Himalayas gneiss. With an increase in the degree of disturbance, the compressive strength c and φ decreased. The disturbance exerted a greater influence on the frictional strength than cohesion. In addition, the frictional strength cannot be fully mobilised in gneiss with a high disturbance, which is supported by the unchanged normalised crack initiation stress and the reduction of shear cracks. The internal fracture network reconstructed by CT scanning indicates that the fracture modes of gneiss are determined by the disturbance. With the advancement of disturbance, the main failure mode of gneiss is transformed from shear sliding failure controlled by foliation into splitting failure controlled by microcracks.

Surface temperature characteristics of underwater thermal jet based on thermal skin

In this study, the effect of underwater thermal jet on the thermal skin of water surface were conducted by experiments. The parameters, such as the Reynolds number, underwater depth, disturbance degree of the propeller, and the temperature difference between the thermal jet and ambient water, on the temperature distribution of the water thermal skin were analyzed. The results demonstrate that the infrared signal of the water surface is mainly caused by the destruction of thermal skin structure but not the direct thermal signal generated by the buoyancy of the thermal wake. Moreover, the damage of the thermal skin is closely related to the flow field of the lower water column. As the depth of the underwater jet increases, the greater the temperature difference between the jet and ambient water, the larger is the area of temperature signal generated by the water surface, with a positive correlation between them. When the depth of the hot jet under the action of the thruster is small (d/D<0.36Fr), the structure of cooling water is unstable during its rising due to the inhibition of water surface. This, has a random effect on the infrared signal of the water surface. This study could provide experimental support for revealing the mechanism of infrared characteristics at water surface caused by the buoyancy of underwater thermal jet.