Journal articles: 'Biological disturbances'

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Tooker, John F., Matthew E. O'Neal, and Cesar Rodriguez-Saona. "Balancing Disturbance and Conservation in Agroecosystems to Improve Biological Control." Annual Review of Entomology 65, no. 1 (January 7, 2020): 81–100. http://dx.doi.org/10.1146/annurev-ento-011019-025143.

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Disturbances associated with agricultural intensification reduce our ability to achieve sustainable crop production. These disturbances stem from crop-management tactics and can leave crop fields more vulnerable to insect outbreaks, in part because natural-enemy communities often tend to be more susceptible to disturbance than herbivorous pests. Recent research has explored practices that conserve natural-enemy communities and reduce pest outbreaks, revealing that different components of agroecosystems can influence natural-enemy populations. In this review, we consider a range of disturbances that influence pest control provided by natural enemies and how conservation practices can mitigate or counteract disturbance. We use four case studies to illustrate how conservation and disturbance mitigation increase the potential for biological control and provide co-benefits for the broader agroecosystem. To facilitate the adoption of conservation practices that improve top-down control across significant areas of the landscape, these practices will need to provide multifunctional benefits, but should be implemented with natural enemies explicitly in mind.

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Poluektov, M. G., and P. M. Khadzhaeva. "Biological rhythm disturbances in depression." Medical alphabet 2, no. 19 (November 26, 2019): 5–10. http://dx.doi.org/10.33667/2078-5631-2019-2-19(394)-5-10.

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Depression belongs to the diseases with pronounced medical and social consequences, which include disability, reduced social functioning and suicides. There is the evidence that the depressive manifestations are closely related to disorders of circadian periodism and the function of the suprachiasmatic nuclei of the hypothalamus, the leading driver of biological rhythms. Authors reviewed the possibility to apply the concept of biological rhythms to the development and clinical features of depressive disorder. The potential effects of chronobiotic drugs like melatonin agonists is discussed.

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Burton, Philip J., Anke Jentsch, and Lawrence R. Walker. "The Ecology of Disturbance Interactions." BioScience 70, no. 10 (September 16, 2020): 854–70. http://dx.doi.org/10.1093/biosci/biaa088.

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Abstract Global change has been accompanied by recent increases in the frequency and intensity of various ecological disturbances (e.g., fires, floods, cyclones), both natural and anthropogenic in origin. Because these disturbances often interact, their cumulative and synergistic effects can result in unforeseen consequences, such as insect outbreaks, crop failure, and progressive ecosystem degradation. We consider the roles of biological legacies, thresholds, and lag effects responsible for the distinctive impacts of interacting disturbances. We propose a hierarchical classification that distinguishes the patterns and implications associated with random co-occurrences, individual links, and multiple links among disturbances that cascade in chains or networks. Disturbance-promoting interactions apparently prevail over disturbance-inhibiting ones. Complex and exogenous disturbance cascades are less predictable than simple and endogenous links because of their dependency on adjacent or synchronous events. These distinctions help define regional disturbance regimes and can have implications for natural selection, risk assessment, and options for management intervention.

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De Grandpré, Louis, Kaysandra Waldron, Mathieu Bouchard, Sylvie Gauthier, Marilou Beaudet, Jean-Claude Ruel, Christian Hébert, and Daniel Kneeshaw. "Incorporating Insect and Wind Disturbances in a Natural Disturbance-Based Management Framework for the Boreal Forest." Forests 9, no. 8 (August 2, 2018): 471. http://dx.doi.org/10.3390/f9080471.

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Natural disturbances are fundamental to forest ecosystem dynamics and have been used for two decades to improve forest management, notably in the boreal forest. Initially based on fire regimes, there is now a need to extend the concept to include other types of disturbances as they can greatly contribute to forest dynamics in some regions of the boreal zone. Here we review the main descriptors—that is, the severity, specificity, spatial and temporal descriptors and legacies, of windthrow and spruce bud worm outbreak disturbance regimes in boreal forests—in order to facilitate incorporating them into a natural disturbance-based forest management framework. We also describe the biological legacies that are generated by these disturbances. Temporal and spatial descriptors characterising both disturbance types are generally variable in time and space. This makes them difficult to reproduce in an ecosystem management framework. However, severity and specificity descriptors may provide a template upon which policies for maintaining post harvesting and salvage logging biological legacies can be based. In a context in which management mainly targets mature and old-growth stages, integrating insect and wind disturbances in a management framework is an important goal, as these disturbances contribute to creating heterogeneity in mature and old-growth forest characteristics.

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Dornelas, Maria. "Disturbance and change in biodiversity." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1558 (November 27, 2010): 3719–27. http://dx.doi.org/10.1098/rstb.2010.0295.

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Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numerous composite disturbances can be defined including any combination of these three types of ecological effects. The consequences of D , B and K disturbances, as well as of composite DBK disturbances are examined by comparing metrics before and after a disturbance, in disturbed and undisturbed communities. I use simulations of neutral communities and examine species richness, total abundance and species abundance distributions. The patterns of change in biodiversity metrics are consistent among different types of disturbance. K disturbance has the most severe effects, followed by D disturbance, and B disturbance has nearly negligible effects. Consequences of composite DBK disturbances are more complex than any of the three types of disturbance, with unimodal relationships along a disturbance gradient arising when D, B and K are negatively correlated. Importantly, regardless of disturbance type, community isolation enhances the negative consequences and hinders the positive effects of disturbances.

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Wirz-Justice, Anna. "Biological rhythm disturbances in mood disorders." International Clinical Psychopharmacology 21, Supplement 1 (February 2006): S11—S15. http://dx.doi.org/10.1097/01.yic.0000195660.37267.cf.

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Stout, Benjamin B. "Old Disturbances." BioScience 40, no. 8 (September 1990): 556. http://dx.doi.org/10.2307/1311291.

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Antsyborov, Andrey Viktorovich, Anna Valerievna Kalinchuk, and Irina Vladimirovna Dubatova. "Sleep and Depression: What We Know and What to Learn?" Interactive science, no. 7 (53) (October 20, 2020): 33–49. http://dx.doi.org/10.21661/r-551927.

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Presently, a lot of data indicate that the disturbance of mechanisms underlying the regulation of sleep-waking cycle coincides with the mechanisms underlying the development of depression. The disturbance of circadian rhythms is one of the core factors in the genesis of the most affective disorders including depression, which indicates the role of the internal biological clock in the pathophysiology of affective disorders. The episodes of depression, mania or hypomania may result from the disturbances in endogenous biological timing. In this review, we have summarized the literature data obtained in animal models or in the patients with affective pathology, in which the connection between the function of sleep and depression was demonstrated. Specifically, we highlight the mechanisms underlying sleep dysfunction during depression (imbalance of circadian rhythms, melatonin metabolism and mechanisms of neuroinflammatory dysregulation) and provide an evidence for the link between sleep function and depression (sleep disturbances during depressive episodes, the effects of pharmacotherapy, chronotherapy, the effect of sleep deprivation, comorbidity of obstructive sleep apnea and depression).

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Jacquet, Claire, and Florian Altermatt. "The ghost of disturbance past: long-term effects of pulse disturbances on community biomass and composition." Proceedings of the Royal Society B: Biological Sciences 287, no. 1930 (July 8, 2020): 20200678. http://dx.doi.org/10.1098/rspb.2020.0678.

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Current global change is associated with an increase in disturbance frequency and intensity, with the potential to trigger population collapses and to cause permanent transitions to new ecosystem states. However, our understanding of ecosystem responses to disturbances is still incomplete. Specifically, there is a mismatch between the diversity of disturbance regimes experienced by ecosystems and the one-dimensional description of disturbances used in most studies on ecological stability. To fill this gap, we conducted a full factorial experiment on microbial communities, where we varied the frequency and intensity of disturbances affecting species mortality, resulting in 20 different disturbance regimes. We explored the direct and long-term effects of these disturbance regimes on community biomass. While most communities were able to recover biomass and composition states similar to undisturbed controls after a halt of the disturbances, we identified some disturbance thresholds that had long-lasting legacies on communities. Using a model based on logistic growth, we identified qualitatively the sets of disturbance frequency and intensity that had equivalent long-term negative impacts on experimental communities. Our results show that an increase in disturbance intensity is a bigger threat for biodiversity and biomass recovery than the occurrence of more frequent but less intense disturbances.

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Lozon, J. D., and H. J. MacIsaac. "Biological invasions: are they dependent on disturbance?" Environmental Reviews 5, no. 2 (June 2, 1997): 131–44. http://dx.doi.org/10.1139/a97-007.

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We utilize literature surveys to examine the relationship between establishment of exotic species and human or natural disturbances of ecosystems. Of the 133 papers published in 10 ecological journals between 1993 and 1995, 63 reported on field studies involving 299 and 103 successful, nonredundant plant and animal introductions, respectively. Invasions of terrestrial ecosystems dominated (>>97%) the surveyed literature. Disturbance was associated with establishment of exotic species in 56% of these studies, though its importance differed among papers describing plants (68%) and animals (28%). Plants species (86%) were significantly more dependent on disturbance for establishment than were animals (12%). However, animals and plants that were dependent on disturbance for establishment were almost equally dependent (58 versus 68%) on it for range expansion. In a second survey, 402 plant and 103 animal taxa were identified that explicitly linked establishment of exotic species to disturbance. Human activities were attributed with establishment of species in 97 and 57% of these cases, respectively. Common mechanisms associated with establishment of exotic animals included ballast water discharge, intentional releases, and residential development. Establishment of exotic plants was associated with animal activities (e.g., grazing, seed introduction), soil disturbance, forestry, fire, agriculture, and human activities. In contrast to invasions theory, our survey indicates that the association between establishment and spread of exotic species and disturbance ought not be assumed a priori. Some animals repeatedly invade new habitats once geographic barriers are circumvented, indicating that communities may be more receptive to exotic species than previously acknowledged. By contrast, introduced plants established most often in disturbed habitats.

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Bond-Lamberty, B., J. Fisk, J. A. Holm, V. Bailey, and C. M. Gough. "Moderate forest disturbance as a stringent test for gap and big-leaf models." Biogeosciences Discussions 11, no. 7 (July 21, 2014): 11217–48. http://dx.doi.org/10.5194/bgd-11-11217-2014.

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Abstract. Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. In particular, it is unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC, a classic big-leaf model, and the ED and ZELIG gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols, and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ED and ZELIG correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes. Biome-BGC net primary production (NPP) was correctly resilient, but for the wrong reasons, while ED and ZELIG exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. As a result we expect that most ecosystem models, developed to simulate processes following stand-replacing disturbances, will not simulate well the gradual and less extensive tree mortality characteristic of moderate disturbances.

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Dawson, Geraldine, David Hessl, and Karin Frey. "Social influences on early developing biological and behavioral systems related to risk for affective disorder." Development and Psychopathology 6, no. 4 (1994): 759–79. http://dx.doi.org/10.1017/s0954579400004776.

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AbstractDramatic changes take place in the neural physiology and emotional behavior of the human infant during the first 2 years of life. Evidence suggests that certain variations in the infant's early social environment, such as disturbances in mother-infant interaction that are associated with maternal depression, influence the development of biological systems related to the expression and regulation of emotion, particularly those systems involved in frontal lobe, autonomic, and adrenocortical functioning. In this essay, we provide an overview of the links between maternal depression and disruptions in early social and emotional development, and we highlight parallels between disturbances in biological systems found in depressed adults and those found in infants of mothers experiencing depression. We then discuss the possibility of sensitive periods for the enduring influences of maternal depression on the emotional development of these children and for increased risk for affective disorder. Finally, we point to directions for further research on the nature of the intergenerational transmission of emotional disturbance.

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Horváth, Szatmár, and Károly Mirnics. "Immune System Disturbances in Schizophrenia." Biological Psychiatry 75, no. 4 (February 2014): 316–23. http://dx.doi.org/10.1016/j.biopsych.2013.06.010.

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Alessi, Norman E., John W. Alessi, Daniel DeVries, and Sue Loomis. "Language disturbances in depressed children." Biological Psychiatry 25, no. 7 (April 1989): A123. http://dx.doi.org/10.1016/0006-3223(89)91734-4.

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Setter, Renee O., Erik C. Franklin, and Camilo Mora. "Co-occurring anthropogenic stressors reduce the timeframe of environmental viability for the world’s coral reefs." PLOS Biology 20, no. 10 (October 11, 2022): e3001821. http://dx.doi.org/10.1371/journal.pbio.3001821.

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Anthropogenic disturbances are posing unprecedented challenges to the persistence of ecosystems worldwide. The speed at which these disturbances reach an ecosystem’s tolerance thresholds will determine the time available for adaptation and conservation. Here, we aim to calculate the year after which a given environmental stressor permanently exceeds the bounds of an ecosystem’s tolerance. Ecosystem thresholds are here defined as limits in a given stressor beyond which ecosystems have showed considerable changes in community assembly and functioning, becoming remnants of what they once were, but not necessarily leading to species extirpation or extinction. Using the world’s coral reefs as a case example, we show that the projected effects of marine heatwaves, ocean acidification, storms, land-based pollution, and local human stressors are being underestimated considerably by looking at disturbances independently. Given the spatial complementarity in which numerous disturbances impact the world’s coral reefs, we show that the timelines of environmental suitability are halved when all disturbances are analyzed simultaneously, as opposed to independently. Under business-as-usual scenarios, the median year after which environmental conditions become unsuitable for the world’s remaining coral reefs was, at worse, 2050 for any one disturbance alone (28 years left); but when analyzed concurrently, this date was shortened to 2035 (13 years left). When analyzed together, disturbances reduced the date of environmental suitability because areas that may remain suitable under one disturbance could become unsuitable by any of several other variables. The significance of co-occurring disturbances at reducing timeframes of environmental suitability was evident even under optimistic scenarios. The best-case scenario, characterized by strong mitigation of greenhouse gas emissions and optimistic human development, resulted in 41% of global coral reefs with unsuitable conditions by 2100 under any one disturbance independently; yet when analyzed in combination up to 64% of the world’s coral reefs could face unsuitable environmental conditions by one disturbance or another. Under the worst-case scenario, nearly all coral reef ecosystems worldwide (approximately 99%) will permanently face unsuitable conditions by 2055 in at least one of the disturbances analyzed. Prior studies have indicated the projected dire effects of climate change on coral reefs by mid-century; by analyzing a multitude of projected disturbances, our study reveals a much more severe prognosis for the world’s coral reefs as they have significantly less time to adapt while highlighting the urgent need to tackle available solutions to human disturbances.

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Yoo, C. K., S. W. Choi, and I. Lee. "Disturbance detection and isolation in the activated sludge process." Water Science and Technology 45, no. 4-5 (February 1, 2002): 217–26. http://dx.doi.org/10.2166/wst.2002.0591.

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This paper proposes a new fault detection and isolation (FDI) method. This method monitors the distribution of process data and detects changes in this distribution, which reflect changes in the corresponding operating condition. A modified dissimilarity index and a FDI technique are defined to quantitatively evaluate the difference between data sets. This technique considers the importance of each transformed variable in the multivariate system. The FDI technique is applied to a benchmark simulation and to data from a real wastewater treatment plant. Simulation results show that it immediately detects disturbances and automatically distinguishes between serious and minor anomalies for various types of fault. The method not only detects the disturbances, but also isolates the scale of the disturbance, facilitating the interpretation of the disturbance source. The proposed monitoring technique is found to be appropriate for analyzing the biological wastewater treatment process, which is characterized by a variety of fault and disturbance sources and non-stationary characteristics.

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Gómez, Izchel, Rodolfo Silva, Debora Lithgow, Janner Rodríguez, Anastazia Teresa Banaszak, and Brigitta van Tussenbroek. "A Review of Disturbances to the Ecosystems of the Mexican Caribbean, Their Causes and Consequences." Journal of Marine Science and Engineering 10, no. 5 (May 9, 2022): 644. http://dx.doi.org/10.3390/jmse10050644.

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In a relatively short timescale (less than 50 years), urbanization has caused many anthropogenic disturbances that have affected ecosystem health and, directly or indirectly, quality of life for the local human population. Global disturbances, such as climate change, can also have a substantial, overarching impact on ecosystems. In this scenario, natural disturbances, previously considered an integral part of ecosystem dynamics, can now cause irreversible change to the state of ecosystems, and at the same time, negatively impact social and economic systems. The objective of this study was to identify ecosystem disturbances at a site of interest to recommend strategies to improve coastal zone management. We chose the Mexican Caribbean as a case study, because its biological and cultural complexity render it an interesting location from a coastal management point of view. The PRISMA framework was used to conduct a systematic literature review to identify the ecosystem disturbances that affect this area, as well as the main causes and consequences of these disturbances. Additionally, we discuss how disturbances and their impacts, as screened through PRISMA, can be incorporated into a coastal zone management framework. Results need to consider the limitations associated with using this technique e.g., the degree of impact from a current disturbance may vary from that reported in an earlier publication. Despite its limitations, we believe that this methodology proves useful for identifying key ecosystem disturbances and their consequences, providing a useful tool for identifying appropriate actions to inform coastal zone management plans.

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Sniders, A., A. Laizans, and T. Komass. "Invariant Control of the Technological Plants to Compensate an Impact of Main Disturbances Preemptively." Latvian Journal of Physics and Technical Sciences 53, no. 3 (June 1, 2016): 34–44. http://dx.doi.org/10.1515/lpts-2016-0019.

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Abstract The paper considers a survey of the research procedures and results due to invariant control method application perspective for operation quality advancement in several technological plants (wastewater biological treatment tanks and water steam production boilers), which operate under influence of organised and random disturbances. A specified subject of research is the simulation model of the multi-link invariant control system for steam pressure stabilisation in a steam boiler by preemptive compensation of steam load and feed water flow impact on output parameter (steam pressure), developed in MATLAB/SIMULINK. Simulation block-diagram of the steam boiler invariant control system, containing closed loop PID control circuit and open loop DPC circuit, has been composed on the basis of the designed mathematical model of the system components, disturbance compensation algorithms, and operational equation of the invariant control system. Comparative response of the steam boiler, operating under influence of fluctuating disturbances, with conventional PID control and using PID-DPC control with disturbance compensation controller DPC, has been investigated. Simulation results of invariant PID – DPC control system show that output parameter of the steam boiler - pressure remains practically constant under fluctuating disturbances due to a high-speed response of DPC controller.

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Schwartz-Mittelmann, A., and N. I. Galil. "Biological mechanisms involved in bioflocculation disturbances caused by phenol." Water Science and Technology 42, no. 1-2 (July 1, 2000): 105–10. http://dx.doi.org/10.2166/wst.2000.0299.

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The research focused on the clarification of the biological mechanisms involved in bioflocculation disturbances caused by the exposure of suspended biomass to phenol shock loading. Contact experiments were performed by exposing activated sludge biomass under non-growth and under growth conditions to various concentrations of phenol. Severe damage to the settling of biosolids could be observed, especially under growth conditions. The following mechanisms were found to be relevant to these disturbances: (1) cellular lysis resulted in the creation of a fraction of small particles (<0.45 μm) which could be considered as mostly cellular debris, due to their sizes and especially to their lack of oxygen uptake; (2) lower hydrophobicity of biosolids surfaces, could be a result of the amphiphatic properties exerted by the phenol molecule, as well as by the cellular components released to the aqueous phase by lysis and by membranal damage; (3) the exposure to phenol caused the unbinding of exocellular biopolymers from biosolids surfaces to the aqueous solution, creating conditions of poor settleability resulting from: (a) bioflocs characterized by low density; (b) dispersion of small biofloc fragments; (c) dispersion of single cells; (4) phenol loading was found able to lower the cellular ATP concentrations and this inhibition of the cellular bioenergetics could also be a factor impairing the boflocculation process.

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Sayagh, Sanae, Leila Benchekroun, Mounya Bouabdellah, Nezha Jaouhar, Farida El Aoufi, Fatiha El Oufir, Meryem Alaoui, Mohammed Adnaoui, and Layachi Chabraoui. "Biological disturbances during the lupus-associated pancreatitis: case report." Annales de biologie clinique 73, no. 4 (July 2015): 485–90. http://dx.doi.org/10.1684/abc.2015.1065.

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Tarakçıoğlu, Mahmut, Direnç Sakarya, Şennur Aksoy, Ayşegül Sakarya, and Umut Aksoy. "BIOLOGICAL RHYTHMS DISTURBANCES IN DRUG-FREE ADULT ADHD PATIENTS." Psychiatry and Behavioral Sciences 9, no. 1 (2019): 1. http://dx.doi.org/10.5455/pbs.20180815041833.

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Zisapel, N. "Sleep and sleep disturbances: biological basis and clinical implications." Cellular and Molecular Life Sciences 64, no. 10 (March 15, 2007): 1174–86. http://dx.doi.org/10.1007/s00018-007-6529-9.

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Strickler, J. Rudi, and Gábor Balázsi. "Planktonic copepods reacting selectively to hydrodynamic disturbances." Philosophical Transactions of the Royal Society B: Biological Sciences 362, no. 1487 (May 2007): 1947–58. http://dx.doi.org/10.1098/rstb.2007.2080.

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In the water column, planktonic copepods encounter small-scale hydrodynamic disturbances generated by fellow zooplankters. Our question is whether or not the copepods can distinguish between hydrodynamic disturbances created by predators, prey, conspecifics and/or mates. We used a Schlieren optical system with a density gradient in the water volume and filmed at 48 frames per second to record the behaviour of copepods during encounters with an artificial hydrodynamic disturbance. We observed the reactions of Cyclops scutifer and Epischura nordenskioldi towards disturbances of different strengths. We also re-examined an earlier report on tandem swimming in C. scutifer while attempting to mate, using novel mathematical tools to analyse possible correlations between the two mates. We conclude that the information within the hydrodynamic disturbances created by swimming zooplankters has enough content for differentiated reactions. We also suggest that the adaptive value of tandem swimming during mating results in offspring capable of executing escape reactions comparable in strength to the disturbances.

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Sadeghassadi, M., C. J. B. Macnab, and D. Westwick. "Design of a generalized predictive controller for a biological wastewater treatment plant." Water Science and Technology 73, no. 8 (January 28, 2016): 1986–2006. http://dx.doi.org/10.2166/wst.2016.050.

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This paper presents a generalized predictive control (GPC) technique to regulate the activated sludge process found in a bioreactor used in wastewater treatment. The control strategy can track dissolved oxygen setpoint changes quickly, adapting to the system uncertainties and disturbances. Tests occur on an Activated Sludge Model No. 1 benchmark of an activated sludge process. A T filter added to the GPC framework results in an effective control strategy in the presence of coloured measurement noise. This work also suggests how a constraint on the measured variable can be added as a penalty term to the GPC framework which leads to improved control of the dissolved oxygen concentration in the presence of dynamic input disturbance.

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Adolf, C., C. Tovar, N. Kühn, H. Behling, J. C. Berrío, G. Dominguez-Vázquez, B. Figueroa-Rangel, et al. "Identifying drivers of forest resilience in long-term records from the Neotropics." Biology Letters 16, no. 4 (April 2020): 20200005. http://dx.doi.org/10.1098/rsbl.2020.0005.

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Here, we use 30 long-term, high-resolution palaeoecological records from Mexico, Central and South America to address two hypotheses regarding possible drivers of resilience in tropical forests as measured in terms of recovery rates from previous disturbances. First, we hypothesize that faster recovery rates are associated with regions of higher biodiversity, as suggested by the insurance hypothesis. And second, that resilience is due to intrinsic abiotic factors that are location specific, thus regions presently displaying resilience in terms of persistence to current climatic disturbances should also show higher recovery rates in the past. To test these hypotheses, we applied a threshold approach to identify past disturbances to forests within each sequence. We then compared the recovery rates to these events with pollen richness before the event. We also compared recovery rates of each site with a measure of present resilience in the region as demonstrated by measuring global vegetation persistence to climatic perturbations using satellite imagery. Preliminary results indeed show a positive relationship between pre-disturbance taxonomic richness and faster recovery rates. However, there is less evidence to support the concept that resilience is intrinsic to a region; patterns of resilience apparent in ecosystems presently are not necessarily conservative through time.

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Subedi, Bodh Raj. "Biophysical disturbances of elephant safaris in the Royal Chitwan National Park, Nepal." Banko Janakari 9, no. 2 (July 2, 2017): 15–19. http://dx.doi.org/10.3126/banko.v9i2.17660.

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The paper explores peoples' perceptions on the biophysical impacts of elephant safaris which is a perfect way to go wildlife viewing, and is very eco-friendly. It surpasses its alternatives, especially noisy Jeep safaris. However, more people are becoming aware of the biophysical impacts of the safaris in the park. They perceived that the safaris cause negative impacts on wildlife and can destroy habitat through soil compaction and erosion, vegetation damage and disturbances. The study also estimated that the current wildlife observation distance from elephant safaris are less than fifteen metres which is too close and may be harmful to wildlife. This study provides interesting comparisons with previous studies on impacts of tourist activities on wildlife from a biological perspective in that the appropriate distances perceived by park staff to view wildlife was the only one to “fit" their findings. The distances perceived by other groups of people as appropriate would in fact, cause unacceptable levels of disturbance. It is concluded that social (human) perception of disturbance by elephant safaris may not accurately reflect the biological severity of their impacts.

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Fenton, Nicole J. "Applied ecology in Canada’s boreal: a holistic view of the mitigation hierarchy and resilience theory." Botany 94, no. 11 (November 2016): 1009–14. http://dx.doi.org/10.1139/cjb-2016-0123.

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Canada’s boreal biome is a mosaic of forests and peatlands. These ecosystems have developed dynamically, periodically affected by disturbance events of significant spatial extent and variable severity, reducing ecosystem biomass. The same ecosystem types typically regenerate from biological legacies. However, concern is growing about the impact of these different anthropogenic disturbances, particularly compound disturbances including climate change, which open the door to shifts to alternate stable states. One strategy promoted to regulate anthropogenic disturbance is the “mitigation hierarchy” for development projects, where impacts on ecosystems are avoided, mitigated, restored, or compensated. This practical approach is not yet integrated into disturbance and resilience theory. Here, I develop an integrated view of the mitigation hierarchy, as well as resilience and disturbance theory, in a boreal context using ecosystem services to measure ecosystem state in a two-step process that first models loss of ecosystem function and then integrates the mitigation hierarchy and resilience theory. The application of this model is discussed in the context of restoration studies after different types of catastrophic anthropogenic disturbance. These studies, some of which are published in this special issue, highlight the important role of bryophytes and understory plants in setting restoration targets and developing criteria and indicators of success.

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Huang, Xuan, Xiaoyu Quan, Xia Wang, Yueli Yun, and Yu Peng. "Is the spider a good biological control agent for Plutella xylostella (Lepidoptera: Plutellidae)?" Zoologia 35 (August 10, 2018): 1–8. http://dx.doi.org/10.3897/zoologia.35.e23481.

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Spiders, as predators of insects and other invertebrates, are an important part of the natural enemies, and they are recognized as an important biological control agent. Plutellaxylostella (Linnaeus, 1758), the diamondback moth (DBM), is a well-known and destructive insect pest of brassicaceous crops worldwide. Here, we analyzed the functional responses of four spiders (Araneae) – Ebrechtellatricuspidata (Fabricius, 1775) (Thomisidae), Pardosalaura (Karsch, 1879) (Lycosidae), Pardosaastrigera (Koch, 1878) (Lycosidae), and Pardosapseudoannulata (Bösenberg & Strand, 1906) (Lycosidae) – on P.xylostella larvae. We also analyzed intraspecific disturbances in the predation reaction and the intensity of scrambling competition of the spiders to P.xylostella larvae. Our results demonstrated that the functional responses of four spiders of different genera were in line with the Holling II model. Two Lycosidae spiders (P.astrigera and P.pseudoannulata) had the potential to control P.xylostella, and female and male spiders that belonged to the same species had different functional responses to P.xylostella. The functional responses of female predation of P.astrigena, P.laura, and P.pseudoannulata was stronger than the males, but male E.tricuspidatus had stronger functional responses to predation than females. We used the Hassell model to describe the intraspecific disturbance experiments of four spiders. There were intraspecific disturbances in the predation reactions of spiders, indicating that the predation ratio of spiders decreased in relation to the increase of its density, and with the increase of spider density, the intensity of scrambling competition of the spider increased.

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Bond-Lamberty, B., J. P. Fisk, J. A. Holm, V. Bailey, G. Bohrer, and C. M. Gough. "Moderate forest disturbance as a stringent test for gap and big-leaf models." Biogeosciences 12, no. 2 (January 27, 2015): 513–26. http://dx.doi.org/10.5194/bg-12-513-2015.

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Abstract. Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. It is thus unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC (BioGeochemical Cycles), a classic big-leaf model, and the ZELIG and ED (Ecosystem Demography) gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ZELIG and ED correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes, in particular gross primary production or net primary production (NPP). Biome-BGC NPP was correctly resilient but for the wrong reasons, and could not match the absolute observational values. ZELIG and ED, in contrast, exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. It is thus an open question whether most ecosystem models will simulate correctly the gradual and less extensive tree mortality characteristic of moderate disturbances.

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Michener, William K., and Richard A. Haeuber. "Flooding: Natural and Managed Disturbances." BioScience 48, no. 9 (September 1998): 677–80. http://dx.doi.org/10.2307/1313330.

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DALE, VIRGINIA H., LINDA A. JOYCE, STEVE MCNULTY, RONALD P. NEILSON, MATTHEW P. AYRES, MICHAEL D. FLANNIGAN, PAUL J. HANSON, et al. "Climate Change and Forest Disturbances." BioScience 51, no. 9 (2001): 723. http://dx.doi.org/10.1641/0006-3568(2001)051[0723:ccafd]2.0.co;2.

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Bisson, Isabelle-Anne, Luke K. Butler, Tim J. Hayden, L. Michael Romero, and Martin C. Wikelski. "No energetic cost of anthropogenic disturbance in a songbird." Proceedings of the Royal Society B: Biological Sciences 276, no. 1658 (December 2, 2008): 961–69. http://dx.doi.org/10.1098/rspb.2008.1277.

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Anthropogenic or natural disturbances can have a significant impact on wild animals. Therefore, understanding when, how and what type of human and natural events disturb animals is a central problem in wildlife conservation. However, it can be difficult to identify which particular environmental stressor affects an individual most. We use heart rate telemetry to quantify the energy expenditure associated with different types of human-mediated and natural disturbances in a breeding passerine, the white-eyed vireo ( Vireo griseus ). We fitted 0.5 g heart rate transmitters to 14 male vireos and continuously recorded heart rate and activity for two days and three nights on a military installation. We calibrated heart rate to energy expenditure for five additional males using an open-flow, push-through respirometry system showing that heart rate predicted 74 per cent of energy expenditure. We conducted standardized disturbance trials in the field to experimentally simulate a natural stressor (predator presence) and two anthropogenic stressors. Although birds initially showed behavioural and heart rate reactions to some disturbances, we could not detect an overall increase in energy expenditure during 1- or 4-hours disturbances. Similarly, overall activity rates were unaltered between control and experimental periods, and birds continued to perform parental duties despite the experimental disturbances. We suggest that vireos quickly determined that disturbances were non-threatening and thus showed no (costly) physiological response. We hypothesize that the lack of a significant response to disturbance in vireos is adaptive and may be representative of animals with fast life histories (e.g. short lifespan, high reproductive output) so as to maximize energy allocation to reproduction. Conversely, we predict that energetic cost of human-mediated disturbances will be significant in slow-living animals.

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Kurz, Werner A., Graham Stinson, and Greg Rampley. "Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?" Philosophical Transactions of the Royal Society B: Biological Sciences 363, no. 1501 (November 20, 2007): 2259–68. http://dx.doi.org/10.1098/rstb.2007.2198.

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To understand how boreal forest carbon (C) dynamics might respond to anticipated climatic changes, we must consider two important processes. First, projected climatic changes are expected to increase the frequency of fire and other natural disturbances that would change the forest age-class structure and reduce forest C stocks at the landscape level. Second, global change may result in increased net primary production (NPP). Could higher NPP offset anticipated C losses resulting from increased disturbances? We used the Carbon Budget Model of the Canadian Forest Sector to simulate rate changes in disturbance, growth and decomposition on a hypothetical boreal forest landscape and to explore the impacts of these changes on landscape-level forest C budgets. We found that significant increases in net ecosystem production (NEP) would be required to balance C losses from increased natural disturbance rates. Moreover, increases in NEP would have to be sustained over several decades and be widespread across the landscape. Increased NEP can only be realized when NPP is enhanced relative to heterotrophic respiration. This study indicates that boreal forest C stocks may decline as a result of climate change because it would be difficult for enhanced growth to offset C losses resulting from anticipated increases in disturbances.

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Wei, Wei, Yanjie Shao, and Min Zuo. "Active Disturbance Rejection Synchronization of Morris-Lecar Neurons." Complexity 2018 (June 5, 2018): 1–10. http://dx.doi.org/10.1155/2018/7656252.

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Synchronization of biological neurons is not only a hot topic, but also a difficult issue in the field of bioelectrical physiology. Numerous reported synchronization algorithms are designed on the basis of neural model, but they have deficiencies like relatively complex and poor robustness and are difficult to be realized. Morris-Lecar neuron is considered, and linear active disturbance rejection control (LADRC) is designed. Only one control input signal is utilized to synchronize membrane potentials of biological neurons. Meanwhile, in order to verify the robustness of synchronization, sinusoidal signal and parameter perturbations are introduced in numerical simulations. LADRC can still achieve satisfactory synchronization. Both theoretical and numerical simulation results show that LADRC is capable of estimating and cancelling disturbances and uncertainties. Neither accurate neural models nor concrete disturbance signal models are indispensable. A more practical and effective thought is provided to address the synchronization between neurons.

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Ferrenberg, Scott, Sasha C. Reed, and Jayne Belnap. "Climate change and physical disturbance cause similar community shifts in biological soil crusts." Proceedings of the National Academy of Sciences 112, no. 39 (September 14, 2015): 12116–21. http://dx.doi.org/10.1073/pnas.1509150112.

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Biological soil crusts (biocrusts)—communities of mosses, lichens, cyanobacteria, and heterotrophs living at the soil surface—are fundamental components of drylands worldwide, and destruction of biocrusts dramatically alters biogeochemical processes, hydrology, surface energy balance, and vegetation cover. Although there has been long-standing concern over impacts of physical disturbances on biocrusts (e.g., trampling by livestock, damage from vehicles), there is increasing concern over the potential for climate change to alter biocrust community structure. Using long-term data from the Colorado Plateau, we examined the effects of 10 y of experimental warming and altered precipitation (in full-factorial design) on biocrust communities and compared the effects of altered climate with those of long-term physical disturbance (>10 y of replicated human trampling). Surprisingly, altered climate and physical disturbance treatments had similar effects on biocrust community structure. Warming, altered precipitation frequency [an increase of small (1.2 mm) summer rainfall events], and physical disturbance from trampling all promoted early successional community states marked by dramatic declines in moss cover and increases in cyanobacteria cover, with more variable effects on lichens. Although the pace of community change varied significantly among treatments, our results suggest that multiple aspects of climate change will affect biocrusts to the same degree as physical disturbance. This is particularly disconcerting in the context of warming, as temperatures for drylands are projected to increase beyond those imposed as treatments in our study.

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Triki, Zegni, and Redouan Bshary. "Fluctuations in coral reef fish densities after environmental disturbances on the northern Great Barrier Reef." PeerJ 7 (April 8, 2019): e6720. http://dx.doi.org/10.7717/peerj.6720.

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Global warming is predicted to increase the frequency and or severity of many disturbances including cyclones, storms, and prolonged heatwaves. The coral reef at Lizard Island, part of the Great Barrier Reef, has been recently exposed to a sequence of severe tropical cyclones (i.e., Ita in 2014 and Nathan in 2015) and a coral bleaching in the year 2016. Reef fishes are an essential part of the coral reef ecosystem, and their abundance is thus a good marker to estimate the magnitude of such disturbances. Here, we examined whether the recent disturbances at Lizard Island had an impact on the coral reef fish communities. To do this, we examined fish survey data collected before and after the disturbances for potential changes in total fish density post-disturbance. Also, by sorting fish species into 11 functional groups based on their trophic level (i.e., diet), we further explored the density changes within each functional group. Our findings showed an overall decline of 68% in fish density post-disturbance, with a significant density decrease in nine of 11 trophic groups. These nine groups were: browsers, corallivores, detritivores, excavator/scrapers, grazers, macro-invertivores, pisci-invertivores, planktivores, and spongivores. The piscivores, on the other hand, were the only “winners,” wherein their density showed an increase post-disturbance. These changes within functional groups might have a further impact on the trophodynamics of the food web. In summary, our findings provide evidence that the fish assemblage on the reefs around Lizard Island was considerably affected by extreme weather events, leading to changes in the functional composition of the reef fish assemblage.

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Temmink, H., B. Petersen, S. Isaacs, and M. Henze. "Recovery of biological phosphorus removal after periods of low organic loading." Water Science and Technology 34, no. 1-2 (July 1, 1996): 1–8. http://dx.doi.org/10.2166/wst.1996.0349.

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Activated sludge plants for enhanced biological phosphorus removal (EBPR) are often disturbed by short periods of low organic loading. Depending on the exact nature of the disturbance this may result in a partial or complete depletion of the internal PHB stores. PHB and phosphate measurements in a pilot-scale EBPR process show that recovery from such disturbances is slow and temporarily results in high phosphate concentrations. The measurements strongly suggest that the main reason for this slow recovery is a dependency of P-uptake on a slowly rising level of PHB. In a number of batch experiments this dependency of P-uptake on PHB was clearly shown. Also, based on the results of these batch experiments, a more detailed analysis was made of the effect of organic loading and aeration time on EBPR recovery. It is concluded that to obtain EBPR recovery, the aeration time should be carefully adjusted to the organic loading, particularly if the organic loading is low.

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Biver, Françoise, Serge Goldman, Véronique Delvenne, André Luxen, Viviane De Maertelaer, Philippe Hubain, Julien Mendlewicz, and Françoise Lotstra. "Frontal and parietal metabolic disturbances in unipolar depression." Biological Psychiatry 36, no. 6 (September 1994): 381–88. http://dx.doi.org/10.1016/0006-3223(94)91213-0.

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van Someren, Eus J. W., Eveline E. O. Hagebeuk, Cees Lijzenga, Philip Scheltens, Sophie E. J. A. de Rooij, Cees Jonker, Anne-Margriet Pot, Majid Mirmiran, and Dick F. Swaab. "Circadian rest—activity rhythm disturbances in alzheimer's disease." Biological Psychiatry 40, no. 4 (August 1996): 259–70. http://dx.doi.org/10.1016/0006-3223(95)00370-3.

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Maia, Tiago V., and Vasco A. Conceição. "Dopaminergic Disturbances in Tourette Syndrome: An Integrative Account." Biological Psychiatry 84, no. 5 (September 2018): 332–44. http://dx.doi.org/10.1016/j.biopsych.2018.02.1172.

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Bungener, Catherine, Celia S. Kosmadakis, Roland Jouvent, and Daniel Widlocher. "Emotional and psychopathological disturbances in HIV-infection." Progress in Neuro-Psychopharmacology and Biological Psychiatry 17, no. 6 (November 1993): 927–37. http://dx.doi.org/10.1016/0278-5846(93)90020-s.

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McEnany, Geoffry. "Part 1: Rhythm & Blues Revisited: Biological Rhythm Disturbances in Depression." Journal of the American Psychiatric Nurses Association 2, no. 1 (February 1996): 15–22. http://dx.doi.org/10.1177/107839039600200105.

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McEnany, Geoffry. "Part II: Rhythm & Blues Revisited: Biological Rhythm Disturbances in Depression." Journal of the American Psychiatric Nurses Association 2, no. 2 (April 1996): 54–57. http://dx.doi.org/10.1177/107839039600200206.

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Flint, R. Warren. "On the use of Biological Controls for Managing Great Lakes Disturbances." Journal of Great Lakes Research 13, no. 1 (January 1987): 93–95. http://dx.doi.org/10.1016/s0380-1330(87)71632-3.

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45

Rees, M., and R. L. Hill. "Large−scale disturbances, biological control and the dynamics of gorse populations." Journal of Applied Ecology 38, no. 2 (April 2001): 364–77. http://dx.doi.org/10.1046/j.1365-2664.2001.00598.x.

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Kireeva, G. S., E. A. Gubareva, M. A. Maydin, A. V. Panchenko, M. L. Tyndyk, E. I. Fedoros, S. S. Kruglov, V. K. Osetnik, and V. N. Anisimov. "REVIEW OF RESEARCH ON THE RELATIONSHIP BETWEEN CIRCADIAN RHYTHMS AND CARCINOGENESIS USING ANIMAL MODELS." Siberian journal of oncology 20, no. 3 (June 29, 2021): 134–43. http://dx.doi.org/10.21294/1814-4861-2021-20-3-134-143.

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Purpose of the study: to review in vivo studies on the relationship and role of various molecular genetic components of the circadian rhythm system in the initiation and development of malignant neoplasms. in contrast to clinical and epidemiological studies, animal models, including transgenic animal models, can model various changes and disturbances in the activity of clock genes and track the results of these changes.Material and Methods. the review includes data from studies carried out over the past 10 years in animal models, studying the mechanisms and effects of disturbances in the system of circadian rhythms related to the formation and development of tumors. the data sources for the review were the Medline, embase and scopus databases.Results. analysis of the literature has shown that interference with the work of the «biological clock» by changing the light cycle, disrupting the expression of clock genes and other manipulations is a factor predisposing to the development of tumors. in tumors of various types, the expression of clock genes is often mismatched, and it is unclear at what stage of their formation this occurs. in addition, the development of tumors disrupts the circadian homeostasis of the body. there are three key areas of research aimed at studying the role of circadian rhythms in tumor development: disturbance of circadian rhythms as a carcinogenic factor, disturbances in the clock gene system in a tumor, disturbances in the clock gene system of the whole organism, provoked by tumor development.Conclusion. the results of studies on animal models demonstrate that the relationship between the disturbance of circadian rhythms and the tumor process is complex since the causal relationship has not yet been studied. in this regard, the prospect of targeted pharmacological correction of circadian rhythms in clinical practice in cancer patients does not seem to be the nearest one.

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Török, Bibiána, János Varga, and Dóra Zelena. "Vasopressin as a Possible Link between Sleep-Disturbances and Memory Problems." International Journal of Molecular Sciences 23, no. 24 (December 7, 2022): 15467. http://dx.doi.org/10.3390/ijms232415467.

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Normal biological rhythms, including sleep, are very important for a healthy life and their disturbance may induce—among other issues—memory impairment, which is a key problem of many psychiatric pathologies. The major brain center of circadian regulation is the suprachiasmatic nucleus, and vasopressin (AVP), which is one of its main neurotransmitters, also plays a key role in memory formation. In this review paper, we aimed to summarize our knowledge on the vasopressinergic connection between sleep and memory with the help of the AVP-deficient Brattleboro rat strain. These animals have EEG disturbances with reduced sleep and impaired memory-boosting theta oscillation and show memory impairment in parallel. Based upon human and animal data measuring AVP levels, haplotypes, and the administration of AVP or its agonist or antagonist via different routes (subcutaneous, intraperitoneal, intracerebroventricular, or intranasal), V1a receptors (especially of hippocampal origin) were implicated in the sleep-memory interaction. All in all, the presented data confirm the possible connective role of AVP between biological rhythms and memory formation, thus, supporting the importance of AVP in several psychopathological conditions.

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Beal-Neves, Mariana, Cleusa Vogel Ely, Marjorie Westerhofer Esteves, Betina Blochtein, Regis Alexandre Lahm, Everton L. L. Quadros, and Pedro Maria Abreu Ferreira. "The Influence of Urbanization and Fire Disturbance on Plant-floral Visitor Mutualistic Networks." Diversity 12, no. 4 (April 3, 2020): 141. http://dx.doi.org/10.3390/d12040141.

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The biodiversity loss resulting from rising levels of human impacts on ecosystems has been extensively discussed over the last years. The expansion of urban areas promotes drastic ecological changes, especially through fragmentation of natural areas. Natural grassland remnants surrounded by an urban matrix are more likely to undergo disturbance events. Since grassland ecosystems are closely related to disturbances such as fire and grazing, grassland plant communities, pollinators, and their interaction networks may be especially sensitive to urban expansion, because it promotes habitat fragmentation and modifies disturbance regimes. This work evaluated the effect of the level of urbanization and recent history of fire disturbance on grassland plants communities and plant-floral visitor mutualistic networks. We sampled plant communities and floral visitors in 12 grassland sites with different levels of urbanization and time since the last fire event. Sites with higher levels of urbanization showed higher values for plant species richness, floral visitor richness, and network asymmetry. All sampled networks were significantly nested (with one exception), asymmetric, and specialized. In addition, all networks presented more modules than expected by chance. The frequency of fire disturbance events increased with the level of urbanization. Since grassland ecosystems depend on disturbances to maintain their structure and diversity, we inferred that the history of fire disturbance was the mechanism behind the relationship between urbanization and our biological descriptors. Our findings highlight the importance of small and isolated grassland remnants as conservation assets within urban areas, and that the disturbance events that such sites are submitted to may in fact be what maintains their diversity on multiple levels.

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Askenasy, J. J. M. "Sleep disturbances in Parkinsonism." Journal of Neural Transmission 110, no. 2 (February 1, 2003): 125–50. http://dx.doi.org/10.1007/s007020300001.

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Whicker, April D., and James K. Detling. "Ecological Consequences of Prairie Dog Disturbances." BioScience 38, no. 11 (December 1988): 778–85. http://dx.doi.org/10.2307/1310787.

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Journal articles on the topic 'Biological disturbances'

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