Sudden Environmental Changes Research Articles

Effect of the sudden change of ambient atmosphere on free radicals in coal body by CO2 fire prevention gas injection

ABSTRACT The coal body’s gas environment transforms during the CO2 fire prevention procedure from an oxygenated ambience to a CO2 gas ambience, which in turn prevents the coal body from continuously oxidizing. To investigate the effect of sudden changes in the gas environment to which the coal body is exposed on the microscopic group reactions, the free radical parameters such as ESR in situ spectra, line widths, g-factors, and free radical concentrations of the coal bodies during the gas atmosphere transition at different temperature moments were measured. The findings are as follows: as the injection temperature point for CO2 rises, the spectral peak height increases, and the paramagnetic center of coal shifts at lower temperature in CO2 atmosphere than in dry air atmosphere. After the abrupt change of gas environment, free radical levels first decrease and subsequently rise. Furthermore, the general development rate of free radicals can be slowed down by injecting CO2 at lower temperatures. Meanwhile, at lower temperatures, the higher the temperature point of the minimum g value is, the smaller the maximum g value is. Changes in a gas atmosphere, sudden decrease in line width of ESR spectra of coal bodies, and the line width finally stabilizes around 0.45. CO2 injection at 70°C has the best inhibitory effect on free radicals.

STUN: forward-time simulation on TUnable fitNess landscapes in recombining populations

Abstract Motivation Understanding the population genetics of complex polygenic traits during adaptation is challenging. Results Here, we implement a forward-in-time population-genetic simulator (STUN) based on Wright-Fisher dynamics. STUN is a flexible and user-friendly software package for simulating the polygenic adaptation of recombining haploid populations using either new mutations or standing genetic variation. STUN assumes that populations adapt to sudden environmental changes by undergoing selection on a new fitness landscape. With pre-implemented fitness landscape models like Rough Mount Fuji, NK, Block, additive, and House-of-Cards, users can explore the effect of different levels of epistasis (ruggedness of the fitness landscape). Custom fitness landscapes and recombination maps can also be defined. STUN empowers both experimentalists and advanced programmers to study the evolution of complex polygenic traits and to dissect the adaptation process. Availability and implementation STUN is implemented in Rust. Its source code is available at https://github.com/banklab/STUN and archived on Zenodo under doi: 10.5281/zenodo.10246377. The repository includes a link to the software’s manual and binary files for Linux, macOS and Windows.

Psychological alienation and its relationship to academic achievement among refugee students in public schools

Introduction. Psychological alienation, characterized by feelings of estrangement and isolation, negatively impacts the academic performance of refugee students in public schools. This sense of alienation, originating from their unique experiences and sudden environmental changes, can impede their educational engagement and adaptation. However, a supportive learning environment can alleviate these effects, enhancing the sense of belonging and facilitating academic success. Therefore, recognizing this relationship between alienation and academic achievement is essential for developing effective educational strategies for refugee students. Aim. This study explores the level of psychological alienation among refugee students in public schools and investigates its relationship with academic achievement. Study participants and methods. The study analyzes data from 160 secondary school students in the Amman Governorate schools for the 2022/2023 academic year utilizing a descriptive analytical approach. A specially prepared psychological alienation scale was used to quantify five dimensions of alienation: self-estrangement, social isolation, aimlessness, non-normative behavior, and rebellion. The results. The study shows that psychological alienation is prevalent among refugee pupils attending public schools, with an average score of 3.68 out of 5, indicative of considerable psychological alienation (184.0%). Mean ratings of 3.76 (18.8%), 3.57 (17%), 3.80 (19%), 3.71 (185.0%), and 3.59 (179.0%) were assigned to the aspects of alienation from oneself, social isolation, the aimless, non-normative, and rebellion, respectively. It was found that there were no significant differences between male and female refugee students' average scores on most dimensions (p-values > 0.05), with some exceptions including Alienation from oneself (M: 7.3, F: 7.1, p=0.23) and Social Isolation (M: 6.8, F: 6.5, p=0.12). Female students scored higher than male students on The Aimless dimension (M: 6.2, F: 6.7, p=0.02), suggesting that they are more aimless. These numbers highlight the widespread psychological alienation among refugee students, highlighting the need for individualised therapies that take into account the nuances of experiences across dimensions, such as those of female students in The Aimless. Conclusions. This study shed light on the pervasiveness of psychological alienation among immigrant kids in public schools, finding no significant differences between the sexes. Although more research is needed to determine the full extent of the relationship between alienation and academic success, this study highlights the critical need for targeted interventions like counselling and mentoring programs to help reduce alienation and improve academic outcomes. Educators, policymakers, and mental health professionals can use these results as a springboard to create holistic educational strategies and support systems tailored to refugee students that will help them flourish emotionally and academically.

Prediction Error Method (PEM)-Based Howling Cancellation in Hearing Aids: Can We Do Better?

This work develops an effective technique acoustic feedback cancellation (AFC) in the digital hearing aid (DHAid) devices. The normalized least mean square (NLMS) algorithm-based AFC method may suffer from a biased convergence. The biased convergence problem is considerably resolved by the prediction error method (PEM)-based AFC (PEM-AFC); however, it may demonstrate a slow convergence. The proposed method’s main structure is based two adaptive filters. The main adaptive AFC filter receives its input from the DHAid receiver signal, while the auxiliary AFC filter is activated by a probe signal. The main idea is to apply a lattice filtering-based pre-processing for decorrelation in the main AFC filter’s update equation. This produces a Newton-like adaptive algorithm with fast convergence. Additionally, the lattice filtering is executed on a sample-by-sample basis, in contrast to the frame-based execution in the traditional PEM-AFC method. As the AFC system converges, the level of the probe signal is decreased to improve the output SNR; however, the low-level input signal slows down auxiliary AFC filter’s convergence. In order to improve the convergence speed, the gradient information from a maximum Versoria-criterion (MVC) is incorporated into the auxiliary AFC filter’s update algorithm. The two adaptive filters’ coefficients are exchanged, to ensure that both adaptive filters converge to a good estimate of the true acoustic feedback path. Simulations show that the proposed method works well for speech/signals and for DHAid devices with different gain settings. Additionally, the proposed method shows robust performance in the event of a sudden change in the acoustic environment.

Academic impact of sudden and unforeseen changes in the learning environment due to the COVID-19 pandemic

Academic impact of sudden and unforeseen changes in the learning environment due to the COVID-19 pandemic

ПРИЧИНИ СТРАТЕГІЧНИХ ЗМІН ТА АДАПТИВНІ МОЖЛИВОСТІ ПРОТИСТОЯННЯ ЇМ В ПРОЦЕСІ РЕАЛІЗАЦІЇ СТРАТЕГІЇ

The article reveals the reasons for strategic changes, which require a quick response to them for the further development of the organization and the search for new adaptive approaches in the process of implementing the organization's strategy. Ways to accelerate strategic changes in the organization are revealed, namely: the introduction of new technologies, which will be used to produce goods with a new price and quality, new market segments where enterprises will be evaluated by the main competitors, new distribution channels and reorientation of the market, where the nature of demand is changing, the use of new regulatory documents (contracts, laws, decisions, etc.) and sudden changes in the external environment, manifested in the price of goods, in the exchange rate etc., or in political cataclysms that can cause changes in the organization's position on the market. The reasons for the delayed response to external changes affecting the development of a strategy for adapting to the changed situation are considered. These include: inattention, i.e. not paying attention in time to a decrease, for example, in sales volumes, a period of delay, when lower levels of management are aware of the presence of serious problems, although in many cases they cannot influence the situation, since the real power lies with top management, cost reduction, which is false, because the problem is not the level of productivity, but the feasibility of production, a forced change when the policy of cost reduction did not justify itself and a sharp turn (specific changes) in investment policy, when the effective actions of the new management team were adopted. The possibilities of resistance to changes are given, namely: reducing the delay in strategic reaction, where strategic management deals with the problems of accelerating the process of "turning" when adapting to new external conditions, effective management information systems for effective monitoring of consumer behavior, use of strategic opportunities oriented to consumers, adaptation of the organization (for example, business reorganization, diversification of production and markets, search for leaders who are capable of active and decisive actions), rapid personnel changes to identify a reserve capable of being a leader in a period of sudden changes and bringing the organization out of crisis.

Cultural Differences in Coping with Changes in the External Environment: A Case of Behavioural Segmentation of Senior Consumers Based on Their Reaction to the COVID-19 Pandemic

A sudden change in the external environment, such as the COVID-19 pandemic meant for the senior customers in CEE, required coping mechanisms to adapt and a significant change in behavioural patterns. The paper presents what were the social and customer behaviour changes among elderly citizens caused by the pandemic and aims to identify regional differences in adapting to these changes. Results from CATI interviews of 5875 participants from Germany, the Czech Republic, and Slovakia, which had been conducted as a part of the international SHARE project bring a deeper understanding of regional differences. Behavioural segmentation done in each of the researched countries shows that the created clusters in each country are different and yet similar in certain aspects. Clusters of “adapters” – seniors with partial behavioural change are found in all three countries, even though they vary in some aspects of behaviour, they have significant commonalities as well. A cluster of “vulnerable” – seniors that had undergone a complete change of behavioural patterns to protect themselves - or a cluster of “resistant” – seniors resisting the change are found only in two of researched countries. Differences in understanding the threat and feeling the need to react in certain ways are found not only between countries but also within cultures. By employing Hofstede´s cultural dimensions score to explain detected differences, the article brings more understanding of how Power Distance, Indulgence, and Individualism could form differences in the usage of coping mechanisms among the elderly. The results bring insight into important aspects of changes in behaviour, which should be understood and mirrored in the business strategies of companies whose actual or potential customers are represented by this population. Implications for Central European audience: The research on behavioural changes among senior consumers due to the Covid-19 pandemic had been done in three countries of CEE – Slovakia, the Czech Republic, and Germany and therefore, the implications are well suitable for the CEE region, yet the generalization to other countries must be done carefully as the results show that created behavioural segments in researched countries indicate cultural differences.Â

Short time extremal response to step stimulus for a single cell E. coli

After application of a step stimulus, in the form of a sudden change in attractant environment, the receptor activity and tumbling bias of an E. coli cell change sharply to reach their extremal values before they gradually relax to their post-stimulus adapted levels in the long time limit. We perform numerical simulations and exact calculations to investigate the short time response of the cell. For both activity and tumbling bias, we exactly derive the condition for extremal response and find good agreement with simulations. We also make experimentally verifiable prediction that there is an optimum size of the step stimulus at which the extremal response is reached in the shortest possible time.

Context-independent expression of spatial code in hippocampus

The hippocampus plays a crucial role in the formation and retrieval of spatial memory across mammals and episodic memory in humans. Episodic and spatial memories can be retrieved irrespective of the subject’s awake behavioral state and independently of its actual spatial context. However, the nature of hippocampal network activity during such out-context retrieval has not been described so far. Theoretically, context-independent spatial memory retrieval suggests a shift of the hippocampal spatial representations from coding the current spatial context to coding the remembered environment. In this study we show in rats that the CA3 neuronal population can switch spontaneously across representations and transiently activate another stored familiar spatial pattern without direct external sensory cuing. This phenomenon qualitatively differs from the well-described sharp wave-related pattern reactivations during immobility. Here, it occurs under the theta oscillatory state during active exploration and reflects the preceding experience of sudden environmental change. The respective out-context coding spikes appeared later in the theta cycle than the in-context ones. Finally, the experience also induced the emergence of population vectors with a co-expression of both codes segregated into different phases of the theta cycle.

Selective effects of a short transient environmental fluctuation on a natural population.

Natural populations experience continuous and often transient changes of environmental conditions. These in turn may result in fluctuating selection pressures leading to variable demographic and evolutionary population responses. Rapid adaptation as short-term response to a sudden environmental change has in several cases been attributed to polygenic traits, but the underlying genomic dynamics and architecture are poorly understood. In this study, we took advantage of a natural experiment in an insect population of the non-biting midge Chironomus riparius by monitoring genome-wide allele frequencies before and after a cold snap event. Whole genome pooled sequencing of time series samples revealed 10 selected haplotypes carrying ancient polymorphisms, partially with signatures of balancing selection. By constantly cold exposing genetically variable individuals in the laboratory, we could demonstrate with whole genome resequencing (i) that among the survivors, the same alleles rose in frequency as in the wild, and (ii) that the identified variants additively predicted fitness (survival time) of its bearers. Finally, by simultaneously sequencing the genome and the transcriptome of cold exposed individuals we could tentatively link some of the selected SNPs to the cis- and trans-regulation of genes and pathways known to be involved in cold response of insects, such as cytochrome P450 and fatty acid metabolism. Altogether, our results shed light on the strength and speed of selection in natural populations and the genomic architecture of its underlying polygenic trait. Population genomic time series data thus appear as promising tool for measuring the selective tracking of fluctuating selection in natural populations.

The effect of changing from campus-based to digital teaching on student attendance: A case study of Norwegian business students

Over the last two years, the Covid-19 pandemic has forced colleges, university colleges, and universities around the world to switch from campus-based to web-based teaching. The current study examines the effect on students' attendance rates from this sudden change in the learning environment. Data from four completions of a single course given to third-year bachelor students in the business administration program at a mid-sized university college in Norway were used to empirically examine how the level- and trend of the attendance rate were affected during the lockdown period. By means of regression analysis, the results show that digital lectures had a significantly higher attendance rate compared with traditional campus-based lectures. No significant difference in the trends of the attendance rate over the semester was found between the two lecture forms.

Bird Diversity in Ayer Hitam Utara Forest Reserve, Johor and Implications on Peat Swamp Forest Management Strategies

Ayer Hitam Utara Forest Reserve (AHUFR) is the largest and last existing peat swamp forest in Johor. Peat swamp forest are known to be very important as it serve as a home to variety of flora and fauna, especially the bird species. Other than that, peat swamp forest also prone to forest fire as it become the major threat in Ayer Hitam Utara Forest Reserve during a hot weather or drought (El Nino events). This problem will cause biodiversity loss and threaten bird’s habitat and behaviour since some birds are extremely susceptible to sudden environmental changes. Therefore, effective management need to be implemented on the peat swamp ecosystem in order to conserve the forest as well as the bird species that inhabit the area. Hence, this study was conducted to provide a preliminary checklist of the bird, while identify the threats faced by AHUFR in order to came out with the best management of peat swamp forest to protect the bird and the wildlife in it. The method used in this study are mist-netting, direct observation with the aid of DSLR camera, video camera, binocular, and spotter scope, sound recording and interview with forest ranger for four days. About 15 species was recorded, five species from direct observation and interview method, three species from sound recording, and two species from mist-netting method. From the data, one vulnerable (VU) and near threatened (NT) species was recorded which are Black Hornbill (Anthracoceros malayanus) (VU) and Fluffy-backed Tit-babbler (Macronus ptilosus) (NT) respectively. Both are native to peat swamp forest. In terms of threat, forest fire was identified as a common problem occurring in AHUFR. The bird diversity in AHUFR can be threatened by the forest fire if there are no action or management taken to by various parties as well as spreading the awareness among the communities according to this issue. Therefore, this study suggested few recommendations of best practices to manage peat swamp forest of AHUFR.

Bifidobacterium animalis Promotes the Growth of Weaning Piglets by Improving Intestinal Development, Enhancing Antioxidant Capacity, and Modulating Gut Microbiota.

Probiotics are widely used to promote performance and improve gut health in weaning piglets. Therefore, the objective of this study was to investigate the effects of dietary supplementation with Bifidobacterium animalis subsp. lactis (B. animalis) JYBR-190 on the growth performance, intestine health, and gut microbiota of weaning piglets. The results showed that the dietary addition of B. animalis significantly improved growth performance and decreased diarrhea incidence. B. animalis increased villus height in the duodenum and elevated goblet cell numbers and amylase activity in the jejunum. Additionally, B. animalis supplementation markedly increased total antioxidant capacity in jejunal mucosa but declined the malondialdehyde content. B. animalis treatment did not affect the mRNA expressions associated with the intestinal barrier and inflammatory cytokine in various intestinal segments. Microbiota analysis indicated that a diet supplemented with B. animalis significantly increased the relative abundances of health-promoting bacteria in the lumen, such as Streptococcus, Erysipelotrichaceae, Coprococcus, and Oscillibacter. There was a trend for B. animalis fed piglets to have a higher relative abundance of B. animalis in ileal digesta. Moreover, B. animalis-treated pigs decreased the abundance of Helicobacter and Escherichia-Shigella in ileal mucosa-associated microbiota. In summary, this study showed that B. animalis supplementation stimulated growth performance, improved gut development, enriched beneficial bacteria abundances, and declined intestinal pathogens populations, while B. animalis had limited effects on the intestinal barrier and immune function. IMPORTANCE In the modern swine industry, weaning is a critical period in the pig's life cycle. Sudden dietary, social, and environmental changes can easily lead to gut microbiota dysbiosis, diarrhea, and a decrease in growth performance. To stabilize intestinal microbiota and promote animal growth, antibiotics were widely applied in swine diets during the past few decades. However, the side effects of antibiotics posed a great threat to public health and food safety. Therefore, it is urgent to find and develop antibiotic alternatives. The growing evidence suggested that probiotics can be preferable alternatives to antibiotics because they can modulate microbiota composition and resist pathogens colonization. In this study, our results indicated that dietary supplementation with Bifidobacterium animalis promoted growth in weaning piglets by improving gut development, increasing beneficial bacteria abundances, and declining pathogens populations.

Lateral septum modulates cortical state to tune responsivity to threat stimuli

Sudden unexpected environmental changes capture attention and, when perceived as potentially dangerous, evoke defensive behavioral states. Perturbations of the lateral septum (LS) can produce extreme hyperdefensiveness even to innocuous stimuli, but how this structure influences stimulus-evoked defensive responses and threat perception remains unclear. Here, we show that Crhr2-expressing neurons in mouse LS exhibit phasic activation upon detection of threatening but not rewarding stimuli. Threat-stimulus-driven activity predicts the probability but not vigor or type of defensive behavior evoked. Although necessary for and sufficient to potentiate stimulus-triggered defensive responses, LSCrhr2 neurons do not promote specific behaviors. Rather, their stimulation elicits negative valence and physiological arousal. Moreover, LSCrhr2 activity tracks brain state fluctuations and drives cortical activation and rapid awakening in the absence of threat. Together, our findings suggest that LS directs bottom-up modulation of cortical function to evoke preparatory defensive internal states and selectively enhance responsivity to threat-related stimuli.

Activation of anthocyanin biosynthesis in high light - what is the initial signal?

Due to their sessile nature, plants cannot escape adverse environmental conditions and evolved mechanisms to cope with sudden environmental changes. The reaction to variations in abiotic factors, also summarized as acclimation response, affects all layers of cellular functions and involves rapid modification of enzymatic activities, the metabolome, proteome and transcriptome on different timescales. One trait of plants acclimating to high light (HL) is the rapid transcriptional activation of the flavonoid biosynthesis (FB) pathway resulting in the accumulation of photoprotective and antioxidative flavonoids, such as flavonols and anthocyanins, in the leaf tissue. Although enormous progress has been made in identifying enzymes and transcriptional regulators of FB by forward and reverse genetic approaches in the past, the signals and signalling pathways permitting the conditional activation of FB in HL are still debated. With this Tansley Insight, we summarize the current knowledge on the proposed signals and downstream factors involved in regulating FB and will discuss their contribution to, particularly, HL-induced accumulation of anthocyanins.

Impact of Work From Home in Information Technology Workers: a self-report study

Background: The COVID-19 pandemic has rendered a large proportion of the workforce unable to commute to work to mitigate the virus's spread. Employees now based at home might like to continue to Work From Home (WFH). These may be fully, or in some capacity, for the foreseeable future, especially in the IT sector. In view of a sudden change in the work environment, we aimed to study the effects of WFH on Information Technology (IT) workers. Methods: Astudy was conducted using a pre-designed questionnaire to compare WFH with routine work and assess its impact on the worker. A total of 876 IT workers consented and participated in the study. They consisted of workers from Bengaluru, Gurugram, and Pune. IT workers who had worked for more than one year in the office and more than six months in WFH during preceding period were eligible for the study. The data was collected via google forms through snowballing technique. Results: The study included 876 Information Technology workers, of which 564 (64%) were males and 312 (36%) were females. About 324 (37%) of the study participants found the work environment suitable for working. A significant lower proportion of stress and productivity outcomes was seen among males as compared to females. About 336 (38%) would prefer working from home even if the pandemic subsides. Conclusion: WFH has had a negative effect on workers' productivity and work-life balance, especially among females who have been hampered with dual responsibilities of work and home care. Hence most females want to return to working in offices.

Polygenic adaptation after a sudden change in environment.

Polygenic adaptation is thought to be ubiquitous, yet remains poorly understood. Here, we model this process analytically, in the plausible setting of a highly polygenic, quantitative trait that experiences a sudden shift in the fitness optimum. We show how the mean phenotype changes over time, depending on the effect sizes of loci that contribute to variance in the trait, and characterize the allele dynamics at these loci. Notably, we describe the two phases of the allele dynamics: The first is a rapid phase, in which directional selection introduces small frequency differences between alleles whose effects are aligned with or opposed to the shift, ultimately leading to small differences in their probability of fixation during a second, longer phase, governed by stabilizing selection. As we discuss, key results should hold in more general settings and have important implications for efforts to identify the genetic basis of adaptation in humans and other species.

Enhancing the Stability of Bacteriophages Using Physical, Chemical, and Nano-Based Approaches: A Review.

Phages are efficient in diagnosing, treating, and preventing various diseases, and as sensing elements in biosensors. Phage display alone has gained attention over the past decade, especially in pharmaceuticals. Bacteriophages have also found importance in research aiming to fight viruses and in the consequent formulation of antiviral agents and vaccines. All these applications require control over the stability of virions. Phages are considered resistant to various harsh conditions. However, stability-determining parameters are usually the only additional factors in phage-related applications. Phages face instability and activity loss when preserved for extended periods. Sudden environmental changes, including exposure to UV light, temperature, pH, and salt concentration, also lead to a phage titer fall. This review describes various formulations that impart stability to phage stocks, mainly focusing on polymer-based stabilization, encapsulation, lyophilization, and nano-assisted solutions.

Online Trajectory Replanning for Sudden Environmental Changes During Automated Parking: A Parallel Stitching Method

Trajectory planning for automated parking has been widely known as more challenging than that for on-road driving due to the nonconvex kinematics, high-dimensional collision-avoidance constraints, and difficulty to determine the global optimum among many local optima. Changes in a dynamic environment easily make a previously planned parking trajectory invalid. Compared with the on-road planners which evade newly emerged obstacles via a nudge or side pass, a parking planner has to replan a completely different trajectory for evasion. A qualified online trajectory replanner should run fast, ensure trajectory continuity, and avoid extra halfway stops. This paper proposes a parallel stitching strategy to fulfill these demands. When the ego vehicle tracks an originally planned parking trajectory online, an evasive trajectory begins to be replanned once a new obstacle is found to block the way. Thereafter, a connective trajectory is planned, the two ends of which are future poses along the original trajectory and the evasive trajectory, respectively. The two ends of the connective trajectory are chosen by greedily evaluating various candidates via parallel computation, which ensures that our replanner runs fast with high solution quality. According to our real-world experiments and simulations, the proposed replanner outperforms the existing ones w.r.t. solution speed and quality. As an interesting feature, our proposed replanner also supports switching to a better homotopy class online.

An Analysis of School-Life Balance in University Students in the Context of Covid-19 Lockdowns

At the beginning of the COVID-19 pandemic, many universities began moving their classes from in-person to online. With the sudden change in the learning environment, students have likely struggled to maintain their school-life balance. Thus, the goal of this study was to investigate whether school-life balance had decreased during COVID-19 lockdowns, and if so, why. Given the limited school life balance research, we also propose an instrument with novel components to measure school-life balance, the School-Life Balance Questionnaire. We found a lower school-life balance was reported during COVID-19 lockdowns and that certain recovery strategies predict school life balance. This study is a preliminary step towards understanding how changes in the learning environment impact school-life balance and what strategies students can use to create an optimal balance between life and school.