Slight Disturbance Research Articles

Multiple-Integrated Biomarker Indexes to Assess the Responses of the Flatfish Achirus lineatus during Exposure to Light Crude Oil Water Accommodated Fraction.

In the present study, we evaluated the biological response of Achirus lineatus to water accommodated fraction (WAF) of light crude oil (American Petroleum Institute gravity 35°) during a sub-chronic bioassay (14 and 28 days) at two different concentrations: 5% v/v (1.20µg∙L- 1 expressed as total polycyclic aromatic hydrocarbons [∑25 PAH]) and 10% v/v (6.61µg∙L- 1 [∑25 PAH]). The responses were evaluated through the biomarker response index (BRI), the integrated biomarker response (IBRv2) and the bioconcentration factor (BCF). The results showed an increase in biological response in relation to WAF concentration and exposure time, which resulted in a slight and moderate disturbance in the basal condition and bioconcentration level of metals (Pb > Ni > V > Cd) in fish tissue. Results in the present study denote that flatfish such as A. lineatus may be negatively influenced by spilled light crude oil.

Биологическая активность горных почв Западного Кавказа после сведения леса

A study of a set of indicators characterizing the ecological state of forest soils in the mountains of the North-Western Caucasus under broad-leaved and mixed forests has been conducted. The aim of the study has been to assess changes in the biological activity of soils of different genesis after deforestation. The objects of the study have been rendzina, gray forest and gray forest-steppe soils of forest and disturbed ecosystems of the Republic of Adugeya at altitudes from 500 to 1635 m above sea level. Logging plots of different ages (from 10 to 40 years old) after deforestation have been considered. The analyzed indicators have included: the content of total and active carbon, the activity of soil enzymes (catalase, invertase, dehydrogenase, urease, phosphatase), the number of bacteria, as well as an integral index of the biological properties of the soil. The correlation of these indicators with hydrothermal conditions, density of soil structure, penetration resistance, medium reaction, hydrolytic acidity, total absorbed bases and other soil parameters has been evaluated. The level of biological activity of soils in logging areas in the low mountains of Adygea depends on the relief and the timing of restoration after deforestation. Even after several decades of restoration of woody vegetation on the slopes of 12–15° there is no complete return of biological activity to the values of Greyic Phaeozem Eutric of the background forest area. 40 years after logging, the integral index of biological properties of gray forest soil is still 17 % lower than in the control plot. The biological activity of post-forest soils can change in three main directions. On steep slopes, with severe disturbance of the soil and vegetation cover due to the operation of heavy machinery, the integral index of the biological properties of soils decreases by 25–40 % or more without a tendency to recovery. At an average level of disturbance in plots with slight slopes, after an initial decrease, the soils are restored to control values. Restorative successions with intensive development of herbaceous flora and the turf process with slight disturbance can lead to an increase in biological activity above the control values in just 2–3 years. Comprehensive biodiognostic studies using an integral index of the biological state of the soil have revealed, in general, increased stability of low-mountain terrain soils (gray forest and forest-steppe) compared to the soils of the middle mountains of Adygea (rendzina soils). The main degradation factor that reduces the biological activity of soils disturbed by logging is erosion.

Riedel shear structures reactivation may induce earthquakes through long-term steam injection: A case study of a heavy oil production field in northwestern China

Conventional heavy oil exploitation methods involve steam stimulation and flooding. An oil field in northwestern China has been producing heavy oil via steam injection for several decades. The production area has been seismically quiet until an increase in seismicity occurred several years ago. An array of 40 seismographs has been deployed between July and October 2021 to monitor seismicity and resolve the possible causes of the recent seismicity. Using an end-to-end machine-learning-based high-precision earthquake location workflow, we analyze a microseismic sequence comprised of 178 events that occurred in the study area. Numerical simulations incorporating Coulomb failure stress suggest that prolonged steam injection can reactivate faults and induce seismic events. Similarly, fluid diffusion through conduits may achieve the same effect. Analysis of the focal mechanism solutions of 21 strike-slip and thrust events with [Formula: see text] in conjunction with the background stress regime ([Formula: see text] azimuth = N15°W) reveal that the stress distribution is compatible with a left-lateral Riedel shear structure (RSS) model. Therefore, we can speculate that steam injection may induce earthquakes by reactivating preexisting RSS fault structures. To conclude, the recent seismic events could have been induced by two possible mechanisms: (1) long-term steam injection may cause the static stress level on the faults beneath the reservoir to build up to critical levels, following which a slight stress disturbance can trigger an earthquake and (2) fluid conduits may transport condensed water to basement faults, weakening the faults through fluid diffusion.

CARACTERIZAÇÃO MINERALÓGICA DOS SEDIMENTOS DO IGARAPÉ DIABINHO (FORMAÇÃO SOLIMÕES) NO ESTADO DO ACRE – PROVENIÊNICA E IMPLICAÇÕS AMBIENTAIS

Igarapé Diabinho, situated in the central region of the state of Acre, is a tributary on the right bank of the Envira river, belonging to the Juruá river basin. Its U-shaped grooved channel is carved in sediments known as the Solimões Formation, of Late Miocene–Pleistocene age. The rocky exposures along Diabinho stream demonstrate a succession of massive silt-clay sediments, covered by other compact sandy silts cemented by carbonates. These sediments are partly overlain by alluvial (fluvial-lacustrine) sediments from the Quaternary, in the region where this stream dominates. For the study, samples collected in three profiles along a ravine on the right bank of Igarapé Diabinho were investigated, in an area used for picnics during the dry season, that is, with slight human disturbance. To assist in identifying the probable source areas of these sediments, and determine their weathering and transport conditions, granulometric analyzes were carried out, investigating the mineralogical composition of the sediments, their heavy minerals, and the mineralogy of the sediments’ clay fraction. The sediments are predominantly silts with little clay, being composed of quartz, feldspars (albite and microcline), clay minerals (smectite, illite, and kaolinite), muscovite, and chlorite. As a result, the sediments were deposited in mild paleoclimatic conditions under weak chemical weathering, indicated by the predominance of unstable minerals, such as amphiboles, feldspars, biotite, epidote, garnet, apatite, and titanite. The dominant presence of aluminosilicates (kyanite, andalusite, sillimanite, garnet, and micas) and epidote indicates that these sediments had as their primary source metamorphosed pelitic rocks. A second assemblage composed of tourmaline, zircon, apatite, titanite, and even ilmenite points to possible contributions from basic and intermediate igneous rocks that are currently observed in Serra do Divisor on the borders of Brazil and Peru. In conclusion, these findings contribute to implications in the paleoenvironmental context by providing insights into the probable source areas of the sediments, determining the weathering and transport conditions, and identifying the mineralogy of the sediments.

Perturbation to Symmetries and Adiabatic Invariants for Generalized Birkhoffian Systems on Time Scales

Time scale is a new and powerful tool for dealing with complex dynamics problems. The main result of this study is the exact invariants and adiabatic invariants of the generalized Birkhoffian system and the constrained Birkhoffian system on time scales. Firstly, we establish the differential equations of motion for the above two systems and give the corresponding Noether symmetries and exact invariants. Then, the perturbation to the Noether symmetries and the adiabatic invariants for the systems mentioned above under the action of slight disturbance are investigated, respectively. Finally, two examples are provided to show the practicality of the findings.

Green mechanochemical activation of solid persulfate to remove PAHs in soil: Performance and mechanism

Due to the high biotoxicity and persistence of polycyclic aromatic hydrocarbons (PAHs), the remediation of PAHs-contaminated soil becomes an intractable problem. Persulfate-based advanced oxidation processes are widely used to degrade PAHs in aquatic environment. However, they are not convenient for used in soil due to the heterogeneity and complexity of soil matrix. In this study, a green and convenient ball milling process is introduced to activate persulfate for the remediation of PAHs-contaminated soil. About 82.5% PAHs were removed with 10% wt. Na2S2O8 (PS) addition and ball-milling for 2 h under 500 r/min. The degradation of PAHs is attributed to the attack of radicals (SO4·- and·OH) generated from the activation of PS by mechanochemistry. Moreover, stable Si-O bonds were disrupted during ball-milling process, and formed free electron on the surface of soil particles. This facilitates the electron transfer from oxidants to contaminants. The particle size, surface element composition, functional group, and thermogravimetric analysis confirmed the slight disturbance of ball-milling-assisted PS process on the physical and chemical properties of soil. Therefore, ball-milling assisted PS approach would be a promising technology for the remediation of PAHs-contaminated soil.

In the fed state, autophagy plays a crucial role in assisting the insect vector Rhodnius prolixus mobilize TAG reserves under forced flight activity.

Autophagy is a cellular degradation pathway mediated by highly conserved autophagy-related genes (Atgs). In our previous work, we showed that inhibiting autophagy under starvation conditions leads to significant physiological changes in the insect vector of Chagas disease Rhodnius prolixus; these changes include triacylglycerol (TAG) retention in the fat body, reduced survival and impaired locomotion and flight capabilities. Herein, because it is known that autophagy can be modulated in response to various stimuli, we further investigated the role of autophagy in the fed state, following blood feeding. Interestingly, the primary indicator for the presence of autophagosomes, the lipidated form of Atg8 (Atg8-II), displayed 20%-50% higher autophagic activation in the first 2weeks after feeding compared to the third week when digestion was complete. Despite the elevated detection of autophagosomes, RNAi-mediated suppression of RpAtg6 and RpAtg8 did not cause substantial changes in TAG or protein levels in the fat body or the flight muscle during blood digestion. We also found that knockdown of RpAtg6 and RpAtg8 led to modest modulations in the gene expression of essential enzymes involved in lipid metabolism and did not significantly stimulate the expression of the chaperones BiP and PDI, which are the main effectors of the unfolded protein response. These findings indicate that impaired autophagy leads to slight disturbances in lipid metabolism and general cell proteostasis. However, the ability of insects to fly during forced flight until exhaustion was reduced by 60% after knockdown of RpAtg6 and RpAtg8. This change was accompanied by TAG and protein increases as well as decreased ATP levels in the fat body and flight muscle, indicating that autophagy during digestion, i.e., under fed conditions, is necessary to sustain high-performance activity.

“Neuropsychiatric manifestation of hyponatremia: a case report”

Introduction “Electrolyte abnormalities are commonly encountered in daily clinical practice, and their diagnosis relies on routine laboratory results. Electrolyte disturbances can affect the brain among many other organs and tissues and must be promptly recognized, as they can lead to serious and potentially life-threatening complications if neglected or not appropriately treated. Neurological manifestations reflect the severity of acute neuronal dysfunction and thus require urgent treatment. Acute and/or severe electrolyte imbalances can manifest with rapidly progressive neurological symptoms, seizures, and psychiatric manifestations. They are more frequently observed in patients with sodium disorders (especially hyponatremia), hypocalcemia, and hypomagnesemia.ObjectivesWere the psychiatric manifestations secondary to hyponatremia or epilepsy? Or is it a comorbidity? What are the risk factors? And what is the appropriate course of action for this type of patient?”MethodsWe present, through a clinical case, the situation of a 64-year-old patient who experienced status epilepticus secondary to hyponatremia, requiring hospitalization in the neurology department. Subsequently, she developed psychiatric manifestations with a marked change in behavior. She began experiencing symptoms of anxiety and depressive mood, headaches, somatic complaints, and social isolation. Her condition gradually worsened, necessitating hospitalization in the psychiatry department 3 years later.ResultsThe patient was placed on Carbamazepine by her neurologist, and since then, she has not experienced epileptic seizures. Her follow-up electrolyte panel initially showed slight disturbances before normalizing. Psychiatric manifestations were concurrent with these somatic symptoms and worsened over time. During her psychiatric hospitalization three years later, after a thorough evaluation, she was prescribed Sertraline ans Risperidone in combination with Carbamazepine, resulting in a significant improvement in her condition.ConclusionsIn summary, this case illustrates the critical impact of electrolyte abnormalities on both neurological and psychiatric health, especially in older patients. Understanding risk factors associated with electrolyte imbalances is crucial for effective diagnosis and management, particularly in the elderly. This underscores the importance of a multidisciplinary approach to address the potential serious consequences of electrolyte disturbances on overall patient well-being.Disclosure of InterestNone Declared

Blood Indices of the Patients with β-Thalassemia Minor Compared to the Patients with β-Thalassemia Minor-Alpha-Thalassemia

Objective: Thalassemia, as one of the most common genetic diseases, is a group of hereditary hemoglobin disorders due to a slight disturbance in the production of alpha and beta globin chains in the structure of hemoglobin occurs. There are still no clear criteria for differentiating thalassemia types based on hematological findings. In the current study, we aimed to evaluate the low-grade beta-thalassemia (β-thalassemia) indices in comparison with β-thalassemia minor with alpha-thalassemia (α-thalassemia).
 Methods and materials: In this descriptive-analytic study, 120 patients were enrolled, including 80 patients with minor β-thalassemia and 40 patients with minor β-thalassemia with α-thalassemia. Of all patients, 5cc blood samples were taken. The red blood cell parameters including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and hemoglobin were determined. The level of MCV> 80 and A2> 3.5 β-thalassemia minor and MCV <80 and A2 <3.5 were considered as elevated thalassemia or iron deficiency anemia.
 Results: The results showed that the mean of hemoglobin, HCT, MCH, MCHC, and MCV in the β-thalassemia group was significantly lower than that of the β-thalassemia with α-thalassemia group (P <0.0001). On the other hand, the level of these indices in the control group was significantly higher than in the two groups of patients (P<0.0001). The results showed that the percentage of hemoglobin A2 in the β-alpha-thalassemia group was 4.5 ± 0.91, significantly higher than the β-thalassemia group. The rate of hemoglobin and MCV was significantly lower in the β-thalassemia group compared to the silent and trait β+αthalassemia group. Also, the rate of hematocrit was significantly lower in the β-thalassemia group compared to the trait, although had no significant difference with the silence group.
 Conclusion: Based on our findings, despite the difference between some hematocrit indices in the patients with β-thalassemia and β-αthalassemia, these indices cannot be used as differential indices.

Biophysical insight into the binding mechanism of 1,3-benzodioxole-based lidocaine tagged ionic liquids with BSA: An in-silico, and spectroscopic studies

The interaction between bio-macromolecules and drugs has attracted significant interest for several decades due to their pharmacokinetics and pharmacological implications. Ionic liquids have a major importance in the development of effective drugs that can majorly target and bind to the proteins present in the body. A slight disturbance in the micro-environment of protein induced by a drug can alter the conformations of proteins to lead them to work differently. The interaction of ionic liquids with proteins present in blood such as HSA (Human Serum Albumin) and BSA (Bovine Serum Albumin) provides useful evidence for synthesizing API-based liquid drug and their delivery. In this study, the interaction of BSA with LPAc & LPOT ILs (LPAc: N-(benzo[d][1,3]dioxol-5-ylmethyl)-2-((2,6-dimethylphenyl)amino)-N,N-diethyl-2-oxoethan-1-aminium acetate and LPOT: N-(benzo[d][1,3]dioxol-5-ylmethyl)-2-((2,6-dimethylphenyl)amino)-N,N-diethyl-2-oxoethan-1-aminiumtrifluoromethane sulfonate) using spectroscopic methods like UV–visible, fluorescence, CD spectroscopy, computational studies (molecular docking, MD simulation studies, and ADMET studies). UV–vis spectra showed a slight rise in absorbance intensity with the addition of ionic liquid. A static quenching of BSA with blue shift was observed according to fluorescence spectra on the addition of ionic liquids (LPAc & LPOT) and conformational alterations of BSA were observed by analyzing CD spectra. LPAc and LPOT showed strong binding with BSA with molecular docking scores of −330.2 and −365.2 kcal/mol respectively. The molecular dynamic simulation and in-silico pharmacological and pharmacokinetics studies support the spectroscopic study and molecular docking results inferring that LPOT ionic liquid showed strong binding interactions with BSA. In-vitro studies against A549 cell lines showed that both LAPc and LPOT ionic liquids had antiproliferative properties and LPOT has better anticancer activity as inferred by IC50 value: 38.83 and may be further useful for drug design as cancer therapeutic.

Oxygen locations and electronic structures of oxygenated coinage-metal clusters

The structure features and stability of MnO (M = Cu, Ag and Au; n = 2–9) clusters are investigated using the genetic algorithm combined with the density functional theory (DFT). It is found that CunO and AgnO are more inclined to 3-dimension compact structures, while the transition of AunO from 2 to 3-dimensions occurs at n = 7, in which O atoms prefer to be located on the vertexes regardless of different sizes and configurations of metal Mn cores. Due to the relativistic effect, the stability of AunO is maximum, while the AgnO are less stable, and that of CunO is in between them. The molecular dynamics simulations show that the structures of M4O can maintain integrity with only slight disturbances of individual atoms at a temperature of 300 K. But only the Au4O is stable at 500K, and the Ag4O and Cu4O have severely structural deformation. In most cases, the density of states of larger-sized MnO can be regarded as the superposition of small clusters, and distributions of the curves are in good agreement on the whole. The molecular orbitals reveal that the HOMO/LUMO orbitals are mainly distributed around the M atoms. The natural population analysis charges show that the charge-transferring direction is from M to O atoms, where the charge of O atoms exhibits odd–even oscillation behaviors, with different intensity peaks at the same n.

Effects of forest regeneration types on phosphorus fractions of soil aggregates in subtropical forest.

Soil aggregates are important for the storage and availability of phosphorus in the soil. However, how forest regeneration types affect phosphorus fractions of soil aggregates remains unclear. In this study, we examined the composition of aggregate particle size, phosphorus fractions, phosphorus sorption capacity index (PSOR), legacy phosphorus index (PLGC) and degree of phosphorus saturation by Mehlich 3 (DPSM3) in bulk soils and soil aggregates of Castanopsis carlesii secondary forest (slight disturbance), C. carlesii human-assisted regeneration forest (moderate disturbance), and Cunninghamia lanceolata plantation (severe disturbance), aiming to explore the impact of forest regeneration types on phosphorus availability and supply potential of bulk soils and soil aggregates. The results showed that forest regeneration types significantly influenced the composition of soil aggregates. The proportion of coarse macroaggregates (>2 mm) in the soil of C. carlesii secondary forest and human-assisted regeneration forest was significantly higher than that in the C. lanceolata plantation, while the proportion of silt and clay fraction (<0.053 mm) showed an opposite trend. The composition of soil aggregates significantly affected the contents of different phosphorus fractions. The contents of soil labile phosphorus fractions (PSOL and PM3) decreased as aggregate particle size decreased. The contents of soil total phosphorus (TP), total organic phosphorus (Po), mode-rately labile phosphorus fractions (PiOH and PoOH), and occluded phosphorus (POCL), as well as PSOR and PLGC, exhibited a trend of decreasing at the beginning and then increasing as particle size decreased. The contents of TP, Po, and PiOH in coarse and silt macroaggregates was significantly higher than that in fine macroaggregates (0.25-2 mm) and microaggregates (0.053-0.25 mm). Forest regeneration types significantly influenced the contents of phosphorus fractions of bulk soils and soil aggregates. The contents of TP, Po, PSOL, and PM3 in the soil of C. carlesii secondary forests was significantly higher than that in C. carlesii human-assisted regeneration forest and C. lanceolata plantation. The contents of PSOL and PM3 in different-sized aggregates of C. carlesii secondary forests were significantly higher than that in the C. lanceolata plantation. Forest regeneration types significantly influenced the composition and supply potential of phosphorus fractions in soil aggregates. The proportions of PSOL, and PM3 to TP in different-sized soil aggregates were significantly lower in C. carlesii human-assisted regeneration forest compared with C. carlesii secondary forest. PSOR and DPSM3 in different-sized soil aggregates were significantly lower in C. lanceolata plantation than that in C. carlesii secondary forest. Overall, our results indicated that natural regeneration is more favorable for maintaining soil phosphorus availability, and that forest regeneration affects soil phosphorus availa-bility and its supply potential by altering the composition of soil aggregates.

Triaxial experimental study of mechanical behavior of non-persistent jointed granite subjected to slight cyclic dynamic disturbances

A slight disturbance can induce fault-slip burst failure in deep rock masses. In this paper, a series of triaxial tests were conducted to investigate the strength, deformation characteristics, and failure behavior of non-persistent jointed granite specimens subjected to slight cyclic loading. A representative stress–strain curve for non-persistent jointed rock was generated and used to study the crack evolution process (initiation → propagation → coalescence). The effects of varying the joint angle and frequency and amplitude of the disturbance were then analyzed. A theoretical (fracture mechanics) model for a non-persistent joint subject to triaxial cyclic loading was also established and used to investigate the combined effects of static confining stress and slight disturbances. Finally, the mechanical mechanism by which a slight dynamic disturbance induces fault-slip burst was discussed. Our results show that the failure mode of a non-persistent jointed rock mass depends more on the joint angle than the amplitude and frequency of the slight disturbance. The disturbance induces the initiation and extension of cracks. It can also induce fracture-slip bursting once the disturbance exceeds a certain threshold. The value of this threshold depends on the initial stress state, joint angle, length, dynamic and static friction coefficients, and fracture toughness of the rock. The study thus enriches our mechanistic understanding of the crucial ingredients involved in the triggering of fault-slip rock bursts in deep rock masses by slight disturbances.

Compliant gait control method based on CVSLIP-FF model for biped robot walking over uneven terrain

Bipedal walking over uneven terrain remains a challenging task due to the environmental complexity and unavoidable landing impact. To realize the stable and robust walking of biped robots, this paper proposes a compliant gait control method, which focuses on walking compliance and conducts research on two levels. In the gait generation level, a Continuous-Variable Spring-Loaded Inverted Pendulum with Finite-sized Foot (CVSLIP-FF) model is provided with the consideration of the ankle joint and compliant spring-loaded leg. Then, a CVSLIP-FF based gait generation pattern with relevant walking strategies is provided to enhance the mobility of biped robots. In the joint control level, an ankle joint admittance control strategy is applied to achieve compliant robot-environment interaction. Experimental results indicate that compared with the traditional SLIP model, the proposed method performs better adaptability to uneven terrain with a 217.77% improvement, and enables biped robots to cope with slight unknown disturbance.

Research on capacity allocation of supercapacitor absorbing transient energy based on non-dominated sorting genetic algorithm II

During the actual operation of the power system, various situations will be encountered. A slight disturbance will generate a relatively large transient energy in the system. Estimating the loss and reducing the transient energy well is a very worthwhile research topic. In this paper, we discussed the charging and discharging capability of supercapacitors, proposed a scheme of using parallel supercapacitors to absorb the transient energy generated after grid faults, established a supercapacitor capacity optimization model based on economy and absorption effect, used the NSGA-II Algorithm to find the size of the optimum supercapacitor capacity, and finally carried out modeling and simulating in MATLAB/SIMULINK to verify the absorption effect of the optimal capacity configuration on transient energy.

First Odonata Survey and Utilization of Odonata Diversity as Bioindicator for Sungai Chiling Habitat Quality

A study was conducted at Sungai Chiling Fish Sanctuary in Selangor in assessing the habitat quality by utilizing the Odonata diversity. Sampling using sweep net was conducted for three days from 0900 hours to 1700 hours through the six river crossings. Results showed 48 individuals from 15 species and 6 families were collected and no significant difference for species richness and abundance across the crossings. The species diversity, evenness and species present there indicate good water quality. However, slight disturbance at the entrance based on the Damselfly and Dragonfly species richness and disturbance-associated species present there.

Prevalence of Exercise Related Amenorrhea in Females

Background: Amenorrhea in physically active women is a significant health concern, often associated with intensive exercise and dietary patterns. Understanding its prevalence and influencing factors is essential for devising effective health interventions and promoting women's health in sports. Objective: The study aimed to explore the prevalence of amenorrhea among women regularly engaged in sports or gym activities and to identify key factors affecting menstrual health in this demographic. Methods: This cross-sectional survey, spanning six months, included 71 female athletes aged 13-37 from two fitness centers in Lahore. The research employed non-probability convenient sampling. Data collection was achieved using the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Female Athlete Screening Tool (FAST). Statistical analyses were conducted using IBM SPSS Statistics 20. Results: The participants' mean age was 28.35 ± 5.02 years, with an average BMI of 27.90 ± 3.6. Among them, 18.3% had a normal BMI, 52.1% were underweight, and 29.6% were obese. LEAF-Q results indicated that 70% of participants experienced moderate menstrual disturbances, while 20% had slight disturbances without a clinical diagnosis of amenorrhea. The overall prevalence of amenorrhea was 1.41%. Influential factors included BMI, education, awareness, and guidance from fitness professionals. Conclusion: Contrary to initial expectations of a higher prevalence, the study discovered a relatively low occurrence of amenorrhea (1.41%) among active women. This underlines the importance of targeted educational and support interventions in fitness settings to manage menstrual health. Future research should further examine the interplay between exercise, diet, and menstrual health to improve care for female athletes.

The impacts of disturbances on mountain ecosystem services: Insights from BEAST and Bayesian network

Disturbances, such as wildfire, insect outbreak, wind throw and building construction, can significantly alter ecological processes and impact the supply of mountain ecosystem services (ESs). The comprehensive impacts of vegetation-related disturbances on ESs are poorly known, as most of existing studies have been focused on the impacts of single disturbance. Using the Eastern Helan Mountain as a case study, the vegetation-related disturbances during 1989–2020 were detected and mapped through the BEAST algorithm. Then two critical regulating ESs of carbon sequestration and sand fixation were quantified using CASA model and RWEQ model, respectively. Bayesian Network (BN) was further applied to explore the impacts of disturbances on ESs and identify the “win-win” solutions of ESs in terms of disturbance. The results suggested that BEAST could effectively identify vegetation-related disturbances at various spatio-temporal scales, which was difficult to be captured by normal land use/cover products. The established BN model could simulate the spatio-temporal pattern of sand fixation and carbon sequestration with an average classification error of 13.36% and 9.83%, respectively. Forest conservation and return pasture to forest policy can reduce disturbance frequency and intensity, and improve these two ESs. Both ES generally decreased with disturbance intensity, but firstly decreased and then increased with disturbance frequency. Thus, slight disturbance is beneficial for these ESs, especially in grassland at medium elevation. The “win-win” solutions of these two ESs can be achieved under frequent disturbances with the lowest intensity. Despite the low impacts of disturbances on ESs than other nodes in the BN, their impacts should also be taken into account into ecosystem management due to their inevitability. This BN-based approach turns out to be a promising decision support tool for mountain ecosystem managers to integrate small-scale disturbances into management and provide key information for post-disturbance recovery.

Microseismic Signal Characteristics of the Coal Failure Process under Weak-Energy and Low-Frequency Disturbance

In deep mining, “critical static stress + slight disturbance” is an important inducing form of coal mine rockburst disasters. In previous studies, the critical static stress has been shown to be consistent with the loading direction of a slight disturbance but cannot reflect all types of rockbursts. In addition, the research that uses microseismic (MS) signals to reflect the overall process and critical stages of coal failure and instability under weak-energy and low-frequency disturbance conditions is immature, and more information, such as the critical state, has not been fully revealed. The aims of this paper are to further elucidate the important role of weak-energy and low-frequency disturbances in the occurrence of rockburst disasters. First, briquette samples were prepared from the Tashan Coal Mine, which is severely affected by rockbursts, and their homogeneity was verified using ultrasonic longitudinal wave velocity. Second, the natural frequency of the coal sample specimens was measured using a testing system. Then, based on the self-developed static pressure loading system, dynamic and static combined loading test system and MS signal monitoring device, the MS signal characteristics during the process of coal body failure and instability were comprehensively analysed. Finally, a comparison was made between weak-energy and low-frequency disturbances and impact disturbances. The results are summarized as follows. (1) The longitudinal wave velocity test results reflect that the briquette samples prepared in the experiment have high homogeneity. The smaller the particle size is, the higher the density and moulding pressure, and the denser the sample. (2) The natural frequency of the briquette samples is between 30.79 Hz and 43.34 Hz, and most of them fluctuate at approximately 35 Hz. (3) During the static loading stage, the occurrence of more than three MS signals of larger magnitude in a continuous cluster is an important criterion for the critical failure of the samples. (4) The weak-energy and low-frequency disturbance actually leads to fatigue damage, and the briquette sample experiences three stages: the near-threshold stage, the high-speed expansion stage and the final fracture stage. The smaller the particle size of the coal sample, the denser the specimen, the stronger the amplitude and energy of the single effective MS signal formed during the destruction process, the longer the time duration of crack expansion from the near-threshold stage to the high-speed expansion stage, and the stronger the ability of the coal sample to resist weak-energy and low-frequency disturbances. This study may contribute to a more comprehensive understanding of the destabilization mechanism of coal bodies and MS signal characteristics under weak-energy and low-frequency disturbances and provide a reference for further research and discussion.

Speed Control of PMSM Based on Fuzzy Active Disturbance Rejection Control under Small Disturbances

Permanent Magnet Synchronous Motors (PMSMs), with their simple design, small size, and high-power factor, are ideally suited for realizing high-power AC drives and are widely used in various industries. In this study, Fuzzy Active Disturbance Rejection Control (Fuzzy-ADRC) is used to control the speed of the PMSM. When a slight external disturbance occurs, this control strategy maintains the suppression characteristics of the self-excited control for the disturbance and enhances its ability to compensate for the disturbance. First, a mathematical model was developed to study the surface mount PMSM. Then, a motor control simulation model was created using PI control, vector control, and other control methods. The verification results indicate that the improved Fuzzy-ADRC system performs well under both internal and external minor disturbances. It exhibits a faster dynamic response and reduced regulation time (0.026 s to 0.017 s) compared to the traditional ADRC system. Furthermore, it shows less overshoot (reduced from 70% to 2.9%) compared to the Sliding Mode Observer (SMO). Taken together, the improved Fuzzy-ADRC system is characterized by small steady-state error, high load capacity, and control accuracy. With the assistance of this control strategy, the system can track speed with high accuracy and possesses stronger anti-interference capability to mitigate load disturbances.