General Disturbance Research Articles

Adaptive finite-time pinned and regulation synchronization of disturbed complex networks

This paper investigates robust adaptive pinning control strategies and coupling regulation algorithms to deal with the finite-time synchronization problem of nonlinear complex networks in the presence of general disturbances. First, the concept of finite-time synchronized stability is employed in the sense of finite-time stability. To eliminate the negative impacts of disturbances and nonlinear dynamics, adaptive technique is developed so that the state-dependent rate and constant bounds of disturbances and nonlinear dynamics can be suitably estimated on line. Then, combining the adaptive estimations and Lyapunov functions, pinning control strategies for pinned nodes and two kinds of coupling regulation algorithms for un-pinned nodes are developed to achieve the finite-time bounded synchronization results of the complex dynamical network. Finally, simulation results are carried out to demonstrate the proposed control and regulation methods and their effectiveness.

Effects of a realistic pesticide spraying sequence for apple crop on stream communities in mesocosms: negligible or notable?

BackgroundSeveral large-scale studies revealed impacts and risks for aquatic communities of small rural lakes and streams due to pesticides in agricultural landscapes. It appears that pesticide risk assessment based on single products does not offer sufficient protection for non-target organisms, which are exposed repeatedly to pesticide mixtures in the environment. Therefore, a comprehensive stream mesocosm study was conducted in order to investigate the potential effects of a realistic spraying sequence for conventional orchard farmed apples on a stream community using pesticides at their regulatory acceptable concentrations (RACs). Eight 74-m-long stream mesocosms were established with water, sand, sediment, macrophytes, plankton and benthic macroinvertebrates. In total, nine fungicidal, four herbicidal and four insecticidal pesticides were applied in four of the eight stream mesocosms on 19 spraying event days in the period from April to July while the remaining four stream mesocosms served as controls. The community composition, the abundance of benthos, periphyton and macrophytes, the emergence of insects, physico-chemical water parameters, and drift measurements of aquatic invertebrates were measured.ResultsThe pesticide spraying sequence induced significant effects on invertebrates, periphyton, and macrophytes as well as on the water ion composition especially in the second half of the experiment. It was not possible to relate the observed effects on the community to specific pesticides applied at certain time points and their associated toxic pressure using the toxic unit approach. The most striking result was the statistically significant increase in variation of population response parameters of some taxa in the treated mesocosms compared to the controls. This inter-individual variation can be seen as a general disturbance measure for the ecosystem.ConclusionsThe pesticide spraying sequence simulated by using RAC values had notable effects on the aquatic stream community in the conducted mesocosm study. The results indicate that the current risk assessment for pesticides may not ensure a sufficient level of protection to the field communities facing multiple pesticide entries due to spraying sequences and other combined stress. Hence, there is still room for improvement regarding the prospective risk assessment of pesticides to further reduce negative effects on the environment.

Impacts of fire on soil respiration and its components: A global meta-analysis

As a general disturbance in terrestrial ecosystems, fire can have far-reaching consequences on the carbon (C) cycle. Although soil respiration (SR) is important in regulating atmospheric CO2 concentrations, a general pattern of the response of SR to fire in terrestrial ecosystems remains unclear. In this study, a meta-analysis of 91 studies on fires across 116 global sites was conducted to investigate the effects of fire on SR and its components. The results revealed that the responses of SR and heterotrophic respiration (HR) to fire were dependent on fire severity (low-, moderate-, and high-severity) and types (wildfire and prescribed fire). Specifically, the high- and low-severity fires reduced SR and HR, whereas moderate-severity fires had negligible effects on these parameters. On average, wildfires significantly decreased SR and HR by 13.9% and 18.6%, respectively, across all ecosystems, while prescribed fire reduced SR by 8.4% but did not change HR. In addition, the responses of SR and HR varied with the ecosystem types. Fire decreased SR in all three types of forests (boreal forests: -14.8%, temperate forests: -13.8%, and tropical forests: -28.9%), whereas decreased HR only in boreal and temperate forests (-23.8% and 20.7%, respectively) but not in tropical forests. Moreover, SR decreased directly followed by an increase, whereas HR declined with time after low- and high-severity fires. At a global scale, the responses of SR and HR to fire largely resulted from the changes in soil organic C, dissolved C, microbial biomass C, and belowground biomass, as indicated by the correlation analysis. In addition, the response of SR to fire was negatively affected by the mean annual precipitation in the forests. Overall, our study revealed the mechanisms driving the effects of fire and provided a framework for understanding soil C emissions under intensified fire regimes.

0641 Difficulty Maintaining Sleep and Sleep Quality mediate the Relationship between Sleep Disturbances and Depression

Abstract Introduction Prior epidemiological research has established the relationship between sleep disturbances and depression. Sleep disturbances are also common prodromal features of and comorbid with depression. However, limitations exist across past studies, including the frequent focus on “sleep disturbances” over well-defined facets of sleep, inattention to mediators, and a lack of focus on special populations. As such, there is a need to delineate the relationship between sleep disturbances and depression across specific facets of sleep, particularly in special populations. The current study examined multiple sleep facets as mediators of the relationship between general sleep disturbances and depression severity in college student athletes. Methods Student athletes (N = 993) from the Pacific Athlete Conference-12 completed the Athlete Sleep Screening Questionnaire-Sleep Difficulty Subscale (ASSQ-SDS) and Patient Health Questionnaire-9 (PHQ-9). Parallel multiple mediator models were conducted to examine whether the relationship between sleep disturbances and depression severity was mediated by sleep duration, sleep quality, sleep onset latency, and difficulty maintaining sleep. Results Using bootstrapping with 5,000 resamples, the indirect effect of sleep disturbances on depression severity was significantly different from zero through sleep quality (indirect effect = .17, SE = .07, 95% CI [.04, .31]) and difficulty maintaining sleep (indirect effect = .12, SE = .03, 95% CI [.06, .19]). Sleep disturbances were associated with sleep quality (b = .29, SE = .01, p < .001) and difficulty maintaining sleep (b = .16, SE = .01, p < .001). Sleep quality (b = .59, SE = .16, p < .001) and difficulty maintaining sleep (b = .78, SE = .17, p < .001) were associated with depression severity. No other mediators reached statistical significance. Conclusion Results demonstrate that perceived sleep quality and difficulty maintaining sleep mediate the relationship between general sleep disturbances and depression severity in college student athletes. Findings suggest that sleep quality and difficulty maintaining sleep may be more impactful on depression than other facets of sleep and may be clinically useful targets of intervention for depression. Support (if any)

Extended dynamics observer for linear systems with disturbance

This paper aims at designing observer for single-input-single-output (SISO) linear finite-dimensional systems corrupted by general disturbances. A new observer, referred to as extended dynamics observer (EDO), is proposed to estimate both state and disturbance simultaneously. The only assumption for the observer design is that the plant with unknown disturbance is observable. The disturbance is treated by combination of high-gain and internal model contained in the extended dynamics. The main advantage of the developed method lies in the maximum utilization of the prior information of the disturbance. The more accurate the prior disturbance dynamics we have, the better performance the observer would be. The well-posedness of EDO is established and the theoretical results are validated by numerical simulations.

Relationships between postpartum depression, sleep, and infant feeding in the early postpartum: An exploratory analysis.

The study objectives were to determine the relationships between postpartum depression and maternal and infant sleep parameters and to examine the impact of infant feeding method on infant and maternal sleep and postpartum depression symptomatology. Participants were 61 new mothers aged 18 to 45 years old, and their full-term, normal birth-weight, singleton infants. Participants were recruited from a large teaching hospital in northeast England. Data collection took place in participants' homes. The study used a prospective longitudinal design, with data collected at six, 12 and 18 weeks postpartum. We collected data on total sleep time, longest sleep period, wake after sleep onset, and night waking for mothers and infants objectively from actigraphic records and subjectively from maternal sleep logs. Participants reported on sleep disturbances using the General Sleep Disturbances Scale, on maternal sleepiness, and on depression symptomatology using the Edinburgh Postnatal Depression Scale. Scores on the Edinburgh Postnatal Depression Scale and General Sleep Disturbances Scale were consistently correlated with each other (6 weeks r = 0.452, p < 0.01; 12 weeks r = 0.317, p < 0.05; 18 weeks r = 0.493, p < 0.01), and did not correlate with objective measures or subjective reports of maternal or infant sleep. Edinburgh Postnatal Depression Scale scores at six, 12 and 18 weeks were predicted by General Sleep Disturbances Scale, prior Edinburgh Postnatal Depression Scale score, or both, but not by sleep parameters. With regard to infant feeding method, EPDS score was not higher among exclusively breastfeeding than among exclusively formula-feeding participants at any time point (6 weeks t = 0.306, p = 0.762; 12 weeks t = 0.343, p = 0.733; 18 weeks t = 0.426; p = 0.673). Different pathways emerged to predict Edinburgh Postnatal Depression Scale score for exclusively breastfeeding and exclusively formula-feeding women. Postpartum depression may be associated with disturbed sleep due to negative perception of sleep among depressed women, rather than disrupted sleep causing postpartum depression. With regard to infant feeding method, exclusively breastfeeding women are not more likely to suffer from postpartum depression, and different pathways may predict development of postpartum depression symptoms in exclusively breastfeeding and exclusively formula feeding women.

Anti-disturbance control for a nonlinear flexible beam with velocity disturbance at the boundary

This paper deals with the output feedback stabilization for a nonlinear flexible beam system with a general disturbance at the boundary. An extended state observer is designed to reject the uncertain disturbance estimated by a relatively independent estimator in the feedback loop via the active disturbance rejection control approach. The existence and uniqueness of the solution to the closed-loop beam system are investigated by means of the Galerkin approximation. The asymptotic stability of the closed-loop beam system is shown by utilizing the energy perturbation method. To demonstrate the control performance, numerical simulations are provided by the finite element method.

Specific Habitat Elements (Refuges and Leaf Litter) Are Better Predictors of Sceloporus Lizards in Central Mexico Than General Human Disturbance

Human land transformation alters features of the landscape that may favor or eliminate biodiversity. Understanding habitat use among species in human-affected ecosystems can inform the management of habitats and conservation of species. The Trans-Mexican Volcanic Belt in central Mexico is a biological hot spot for lizard species diversity that is under considerable anthropogenic pressures including grazing, agriculture, urbanization, and climate change. Here, we used species-occupancy modeling to (1) identify habitat characteristics that are essential to predicting the presence of Sceloporus torquatus and S. grammicus lizards, (2) determine if disturbance predicts species occupancy, and (3) determine which features, if any, predict our ability to detect each species in the wild. We found that S. torquatus lizards were more likely to be present in areas with large boulders and abundant refuges, whereas S. grammicus lizards were more common in forests with leaf litter. Human disturbance and urban disruption did not predict the occupancy of either species, with lizards making use of artificial as well as natural refuges in human settlements as well as protected areas. Although we found only weak evidence that habitat and climate predicted detection probabilities, Sceloporus lizards (particularly S. grammicus) were somewhat more easily detected in high humidity, perhaps because of generally higher activity levels. Our results emphasize the importance of understanding the detailed physical characteristics that allow each species to persist, even in disturbed habitats. This can better inform conservation efforts so that resources are allocated to ensure that these characteristics, like rocks and trees, are readily available in both pristine and human-modified areas.

Clinical Treatments of Various Diseases with The Root of Astragalus Membranaceus

Astragalus L., is one of the largest genuses of flowering plants in the Leguminosae family. As annual or perennial herbs, sub shrubs, or shrubs, the plants of Astragalus L. are widely distributed throughout the temperate and arid regions. So far, the genus has been estimated to contain 2000–3000 species and more than 250 taxonomic sections in the world. Astragalus can significantly improve motor and memory impairment following D-galactose induced senescence in mice, which suggests anti-aging effects and possibly a delay in senility of middle-aged mice. The root of A. membranceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao (Radix Astragali) is a precious medicine in TCM, which has the properties of intensifying phagocytosis of reticuloendothelial systems, stimulating pituitary-adrenal cortical activity, and restoring depleted red blood cell formation in bone marrow. Clinically, it is used to treat chronic phlegmatic disorders and general gastrointestinal disturbances including stomach ulcers and diarrhea. It has been used in traditional Chinese medicine (TCM) in the treatment of various renal diseases for over 2000 years and was recorded in Shen Nong’s Materia Medica, which was written in the Han dynasty. Also, it is famed for its antimicrobial, antiperspirant, anti-inflammatory, diuretic and tonic effects. Some plants in the Astragalus genus are well known for their pharmacological properties, particularly hepatoprotective, immunostimulant, and antiviral activities. While, the most common use of this genus is as forage for livestock and wild animals, some plants in this genus have been recognized as being used in foods, medicines, cosmetics, as substitutes for tea or coffee, or as sources of vegetable gums. Saponins, flavonoids, and polysaccharides are believed to be the principle active constituents of Astragalus. This herb possesses tonic, hepatoprotective, diuretic, and expectorant properties and has been shown to exhibit immunomodulating, antihyperglycemic, and antiviral activities, among others. Traditionally, it was used to treat weakness, wounds, anemia, fever, multiple allergies, chronic fatigue, and loss of appetite, uterine bleeding, and uterine prolapse. The plants have also been used for treatment of diabetes, nephritis, leukemia, stomach ulcers, hypertension and chronic bronchitis.

Study of the Effects of Melatonin on Sleep Disorders in Pulmonary Sarcoidosis Patients.

The symptoms of pulmonary sarcoidosis may lead to fatigue, excessive daytime sleepiness, poor sleep quality, and a decrease in quality of life in these patients. This study was designed to evaluate the effects of oral melatonin on sleep disorders of patients with pulmonary sarcoidosis. A randomized, single-blinded clinical trial was conducted on patients with pulmonary sarcoidosis. Eligible patients were randomly allocated into melatonin and control groups. Patients in the melatonin group were given 3 mg melatonin one hour before bedtime for three months. Sleep quality, daytime sleepiness, fatigue status, and quality of life were assessed applying General Sleep Disturbance Scale (GSDS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Assessment Scale (FAS), and the Patient-Reported Outcomes Measurement Information System (PROMIS), respectively, as well as the 12-item Short Form Survey (SF-12) scores at the baseline and three months after treatment. There was a significant change in the GSDS (P < 0.001), PSQI (P < 0.001), ESS (P = 0.002), and FAS (P < 0.001) scores, which were decreased, compared to those of the control group. After intervention¸ global physical health and global mental health raw scores were improved comparing to the control group (P = 0.006, P = 0.02, respectively). The 12-item Short Form Survey evaluation showed that there was a significant difference between the melatonin (3.38 ± 4.61) and control (0.55 ± 7.25) groups in PCS-12 score after three months of therapy (P = 0.02). Our findings showed that supplemental melatonin could significantly improve sleep problems, quality of life, and excessive daytime sleepiness in sarcoidosis patients.

Associations between sleep, reading, and mathematics in Taiwanese children.

Some research shows a link between sleep behaviours and school achievement in English-speaking children and adolescents. The current study aimed to examine the relationship between children's sleep behaviours and aspects of their school achievement in Mandarin-speaking children who are living in Taiwan. The present study reports on 69 second-grade children (age range=6.84-8.4 years) recruited in Taipei City, Taiwan. Children's sleep behaviours were assessed through two standardized parent self-report questionnaires: the Children's Sleep Habits Questionnaire (CSHQ) and the Sleep Disturbance Scale for Children (SDSC). Children undertook three standardized tests of word reading, reading comprehension and math. Key findings include: (i) sleep disturbances are more prevalent when using the CSHQ scale than the SDSC scale, (ii) around half of second graders struggle with general sleep disturbances as observed by the CSHQ scale, (iii) children who go to bed before 22:00 and have at least 9-h sleep tend to exhibit fewer sleep disturbances, (iv) parasomnias as measured by the CSHQ are negatively correlated with reading comprehension after controlling age and nonverbal IQ, and (v) the amount of sleep (naps) during daytime is negatively correlated with Chinese character recognition, reading comprehension and math after controlling age and nonverbal IQ. There is growing awareness of the value of research that spans culturally and linguistically diverse populations. Our study contributes to ongoing discussions about the relationship between sleep, and skills in reading and math in school-aged children in Taiwan.

Illness intrusiveness: A key part of the cognition-mood link in multiple sclerosis.

The current study attempted to expand the literature on cognition and mood in MS by determining if illness intrusiveness may potentially serve as an intermediary factor in the well-established cognition-mood relationship in people with MS. This study employed a retrospective cross-sectional design to answer this question. Baseline neuropsychological test data and mood questionnaires from 199 participants with clinically definite MS were used in this study. The sample was middle-aged (M = 48.4, SD = 11.8), highly educated (M = 14.6, SD = 2.2), majority female (76.9%) and majority White (74.5%). Assumptions for parametric statistics and ordinary least squares regression were met. Conditional process models evaluated whether illness intrusiveness mediated the relationship between cognitive functioning and psychiatric symptoms. In total, 33.2% of the sample met criteria for clinically significant anxiety, 41.7% met criteria for depression, and 27.8% of the sample met criteria for processing speed impairment, consistent with other MS samples. Illness intrusiveness was found to mediate the relationship between processing speed and depression, ab = -.07, 95% CI [-.15, -.002], processing speed and anxiety, ab = -.06, 95% CI [-.12, -.02], and processing speed and more general mood disturbance, ab = -.08, 95% CI [-.13, -.0005]. Illness intrusiveness was found to be a potential important intermediary mechanism by which the primary cognitive impairment in MS, processing speed, impacts mood in this disease population. Conclusions, treatment implications, and directions for future research in light of these findings were discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Event-Triggered and Self-Triggered L∞ Control for Markov Jump Stochastic Nonlinear Systems Under DoS Attacks.

This article investigates event-triggered and self-triggered L∞ control problems for the Markov jump stochastic nonlinear systems subject to denial-of-service (DoS) attacks. When attacks prevent system devices from obtaining valid information over networks, a new switched model with unstable subsystems is constructed to characterize the effect of DoS attacks. On the basis of the switched model, a multiple Lyapunov function method is utilized and a set of sufficient conditions incorporating the event-triggering scheme (ETS) and restriction of DoS attacks are provided to preserve L∞ performance. In particular, considering that ETS based on mathematical expectation is difficult to be implemented on a practical platform, a self-triggering scheme (STS) without mathematical expectation is presented. Meanwhile, to avoid the Zeno behavior resulted from general exogenous disturbance, a positive lower bound is fixed in STS in advance. In addition, the exponent parameters are designed in STS to reduce triggering frequency. Based on the STS, the mean-square asymptotical stability and almost sure exponential stability are both discussed when the system is in the absence of exogenous disturbance. Finally, two examples are given to substantiate the effectiveness of the proposed method.

Reliability and validity of the Turkish version of general sleep disturbance scale (GSDS-T) in stroke.

Stroke is a life-threatening condition with many complications. Sleep disturbances is one of them. Sleep disturbances effect quality of life, recovery and rehabilitation process. It is crucial to reveal sleep disturbances objectively in stroke patients. The aim of the study is to determine reliability and validity of the Turkish version of General Sleep Disturbance Scale (GSDS-T) in stroke patients. After translation and culture validation of the scale was done, Pittsburgh Sleep Quality Index (PSQI) and the Turkish version of the GSDS was applied at admission and at 24h to the 58 patients with stroke. Cronbach alpha coefficient of total score was found as 0.850 and test re-test reliability-related Cronbach alpha coefficient was 0.785. GSDS-T is a reliable and valid tool to assess sleep disturbance in stroke patients.

The Effect Of Dysmenorrhea On Mood Changes In 2020 Yarsi University Faculty Of Medicine Students And According To Islamic Perspective

Background: Dysmenorrhea is defined as painful uterine cramps occurring during menstruation and is one of the most common causes of abdominal pain and menstrual disorders. Not all women who experience menstruation feel comfortable; this is caused by general disturbances such as mood swings, joint pain, and abdominal pain, which is called dysmenorrhea. Women with dysmenorrhea need knowledge about the effects of dysmenorrhea on mood changes. The effect of dysmenorrhea on mood in 2020 YARSI University Faculty of Medicine student is unknown.Methods: This type of research is descriptive-analytic with a cross-sectional study approach. The sample in the study consisted of students from the Faculty of Medicine at YARSI University, class of 2020, with 120 respondents. Data was collected by filling out a questionnaire to measure pain and mood changes, namely Numeric Rating Scale (NRS) and Four Dimensions Mood Scale (FDMS). The analysis was carried out univariately on each variable and bivariate to see the relationship between variables. Results: The results showed that YARSI University Faculty of Medicine students who experienced mild, moderate, and severe dysmenorrhea with negative mood changes, respectively, were 5 people (10.4%), 5 people (10.6%), and 14 people (56%). Mild, moderate, and severe dysmenorrhea with relaxation mood swings affected 10 people (20.8%), 31 people (66%), and 6 people (24%). Mild, moderate, and severe dysmenorrhea with positive mood changes, respectively, affected 33 people (68.8%), 1 person (23.4%), and 5 people (20%). The results of the Chi-Square analysis showed a relationship between the incidence of dysmenorrhea and mood swings.Conclusion: There is a relationship between the incidence of dysmenorrhea and mood swings in 2020 YARSI University Faculty of Medicine students.

Visual testing: the influence of selected human factors on probability of detection

To ensure the reliable assessment of components by visual inspection, current standards overemphasise the focus on illuminance as being the only factor of influence. Human factors or an adaptation of viewing conditions to different inspection tasks are not sufficiently considered. In previous investigations, a significant influence of illuminance, testing forged parts with highly reflective surfaces at three different illuminance levels (200 lx, 350 lx and 500 lx), could not be proven. Instead, a more complex system of different influencing factors was indicated. In this work, groups with different human characteristics were compared to investigate the correlations in indication detectability during visual inspection. A questionnaire was used to record various subjectively perceived factors (dissatisfaction, general and lighting scenariospecific disturbance) in the detection of crack-like indications, under three different lighting scenarios. From the factors studied, age, general and specific experience of the participants were found to be the most relevant. General experience in the field of visual inspection, measured in years and frequency of inspections performed in practice, was shown not to have a decisive influence. On the other hand, the influence of specific experience with the test specimen, or comparable components, and the age of the participants seem to have an influence. With increasing age, the probability of detection seems to decrease, while it seems to increase with rising component-specific experience. In the interplay of the factors investigated, specific experience can be influenced most effectively and could thus be increased by intensified and specific practical training. This could have a positive effect on the reliability of visual inspection.

Learning with Errors Public Key Cryptosystem with Its Security

The main purpose of this paper is to introduce the LWE public key cryptosystem with its security. In the first section, we introduce the LWE public key cryptosystem by Regev with its applications and some previous research results. Then we prove the security of LWE public key cryptosystem by Regev in detail. For not only independent identical Gaussian disturbances but also any general independent identical disturbances, we give a more accurate estimation probability of decryption error of general LWE cryptosystem. This guarantees high security and widespread applications of the LWE public key cryptosystem.

Core body temperature responses during competitive sporting events: A narrative review.

Due to the lack of research in real-world sports competitions, the International Olympic Committee, in 2012, called for data characterising athletes' sport and event-specific thermal profiles. Studies clearly demonstrate that elite athletes often attain a core body temperature (Tc) ≥ 40°C without heat-related medical issues during competition. However, practitioners, researchers and ethical review boards continue to cite a Tc ≥ 40°C (and lower) as a threshold where athlete health is impacted (an assumption from laboratory studies). Therefore, this narrative review aims to: (i) summarise and review published data on Tc responses during competitive sport and identify key considerations for practitioners; (ii) establish the incidence of athletes experiencing a Tc ≥ 40°C in competitive sport alongside the incidence of heat illness/heat stroke (EHI/EHS) symptoms; and (iii) discuss the evolution of Tc measurement during competition. The Tc response is primarily based on the physical demands of the sport, environmental conditions, competitive level, and athlete disability. In the reviewed research, 11.9% of athletes presented a Tc ≥ 40°C, with only 2.8% of these experiencing EHI/EHS symptoms, whilst a high Tc ≥ 40°C (n = 172; Tc range 40-41.5°C) occurred across a range of sports and environmental conditions (including some temperate environments). Endurance athletes experienced a Tc ≥ 40°C more than intermittent athletes, but EHI/EHS was similar. This review demonstrates that a Tc ≥ 40°C is not a consistently meaningful risk factor of EHI/EHS symptomology in this sample; therefore, Tc monitoring alongside secondary measures (i.e. general cognitive disturbance and gait disruption) should be incorporated to reduce heat-related injuries during competition.

Stochastic bifurcation and Break-out of dynamic balance of predator-prey system with Markov switching

This paper investigates Markov-switching-induced stochastic P-bifurcation and the dynamical balance in a predator-prey system. Based on the limit averaging, a probability-weighted system is established to approximate the original stochastic switching ecosystem, then the stationary distribution and first-passage problems are theoretically addressed. Stochastic bifurcations are discussed through a qualitative change of the stationary probability density, which indicates that the transition rate matrix of Markov switching can be treated as a bifurcation parameter. They also imply that the stationary distribution is more sensitive to the transition rate λ12. Besides, by the first-passage theory, the dynamic balance is explored to elucidate the mechanisms underlying species coexistence. Astonishingly, the Markov switching may maintain or even improve the dynamic stability of species coexistence. Biologically, apart from human destruction, the species are even more robust and capable of adapting to general environmental disturbances. The utility and the accuracy of the theoretical analysis are demonstrated by direct numerical simulations.

LifeStyle and Exercise Relation to Neck and Back Pain in Saudi Arabia.

Personal anguish, incapacity, and a decline in work and life quality are all associated with neck and low back pain, making it a significant socioeconomic burden for individuals and society. It iswell knownthat engaging in regular physical exercise has considerable health benefits. The purpose of this research was to investigate the factors contributing to the high rates of musculoskeletal pain experienced by the Saudi Arabian population. This population-based, cross-sectional study was done in Saudi Arabia with 2,717 participants aged 18 to 60. A questionnaire was provided online to assess neck, shoulder, and lower back discomfort, time spent in general or aerobic physical activity, time spent sitting, sleep problems, general health, work satisfaction, and nutrition. Using logistic regression, weobserved potential risk factors for musculoskeletal pain. The prevalence of neck pain, shoulder pain, and lower back pain (LBP) were found to be 48.1%, 47.6%, and 63.8%, respectively. It was found that being a female (OR=1.78 [1.41-2.25], p<0.001), married (OR=1.58 [1.34-1.86], p<0.001), and having poor general health status (OR=3.78 [2.2-6.49], p<0.001), sleep disturbances (OR=2.46 [2.04-2.97], p<0.001) and poor job satisfaction (OR=1.29 [1.05-1.60], p=0.016) were independently associated with the prevalence of musculoskeletal pain. The diet of the individuals did not significantly influence the prevalence of MSPs. Good general health, good sleep, and good job satisfaction were associated with a reduced risk of experiencing neck or shoulder pain, but there was no association between physical activity and MSPs Longitudinal studies are required to acquire a better understanding of the relationship between MSP, aerobic activity, sleep, and diet.