Academic literature on the topic 'Biological disturbances'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Biological disturbances.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Biological disturbances"
1
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.
Full textAbstract:
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.
2
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.
Full textAbstract:
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.
3
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.
Full textAbstract:
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.
4
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.
Full textAbstract:
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.
5
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.
Full textAbstract:
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.
6
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.
Full text
7
Stout, Benjamin B. "Old Disturbances." BioScience 40, no. 8 (September 1990): 556. http://dx.doi.org/10.2307/1311291.
Full text
8
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.
Full textAbstract:
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).
9
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.
Full textAbstract:
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.
10
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.
Full textAbstract:
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.
Dissertations / Theses on the topic "Biological disturbances"
1
Mosisch, Thorsten. "The Effects of Biological and Physical Disturbance on Rainforest Stream Algal Communities." Thesis, Griffith University, 1995. http://hdl.handle.net/10072/366305.
Full textAbstract:
In this study, the effects of biological and physical disturbance on algal assemblages on cobbles in rainforest streams were investigated. Study sites in two rainforest streams, Stony Creek and Booloumba Creek, located in south- east Queensland, were used for both a regular sampling program and an extensive experimental schedule. Previous research has shown that physical disturbance due to spates and, in the absence of high discharge events, biological disturbance due to invertebrate grazing exert significant structuring and controlling forces on periphyton assemblages in streams. The principal objectives in this study were to deternine the relative importance of physical disturbance in the form of spates and desiccation, to outline the significance of biological effects, in particular as a result of grazing pressure, and to describe algal succession on substrates cleared after disturbance events. Periphyton chlorophyll a, biomass values and grazer numbers were monitored over a period of two years in relation to rainfall and stream discharge (to pinpoint the incidence of spates). Periphyton assemblages were composed mainly of diatoms (Cocconeis and Navicula being the dominant genera). Physical disturbance by spates was clearly an important factor structuring stream algal assemblages. Periphyton chlorophyll a and biomass values were reduced following a high discharge event, but then recovered relatively fast in the absence of any other disturbance. Furthermore, chlorophyll a values were correlated with grazer numbers. Differences were observed in the epilithon of Stony Creek and Booloumba Creek: while cobbles in the former supported more chlorophyll a containing material of algal origin and less non-algal biomass, the reverse was true for latter stream. This was most probably due to the physical characteristics of the two stream channels, primarily their slope, which was considerably steeper in Stony Creek, thus requiring less depth to facilitate a major disturbance event. This means that the physical characteristics of streams are most important determining factors regarding the effects of high discharge events, with the disturbance regime playing a significant role in the composition of the stream benthos. However, some major changes in chlorophyll a and biomass occurred in the absence of big disturbances. Periphyton on cobbles collected in the streams was subjected to various time periods out of the water to determine the effects of desiccation. Diatom assemblages on cobbles were not resistant to desiccation and did not recover following re-immersion in the streams. Thus, periods of low flow are capable of reducing periphyton assemblages, however, this type of disturbance would take place over a longer period compared to spates. A colonization experiment where polyethylene foils were introduced into the streams was used to monitor algal succession on bare substrates. Diatoms were the only algae which colonized experimental foils, exhibiting distinct successional patterns in both streams. A series of grazer manipulation experiments were employed to test for any effects of grazing; this involved the inclusion / exclusion of caddisfly larvae from cobbles enclosed in screened perspex cylinders. Signficantly, the effects of grazing invertebrates resulted in an increase in chlorophyll a and biomass values, contrary to expectations and the majority of past studies. This could mean that grazers at a certain density may actually stimulate algal growth and there exists a fine balance between when grazer numbers enhance periphyton productivity or periphyton is overgrazed. Overall, results obtained indicated that variations in stream algal assemblages were a consequence of the combined effects of spates, low flows and, to a lesser extent, grazing.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Graduate School of Environmental Science and Engineering
Science, Environment, Engineering and Technology
Full Text
2
Larsson, Josefine. "Genetic Aspects of Environmental Disturbances in Marine Ecosystems : Studies of the Blue Mussel in the Baltic Sea." Doctoral thesis, Södertörns högskola, Miljövetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-33697.
Full textAbstract:
Anthropogenic environmental changes can serve as drivers for evolutionary responses in wild populations. To predict the long-term impact of anthropogenic changes on populations, it is crucial to understand the genetic effects caused by these disturbances. The Baltic Sea is considered to be one of the world’s most contaminated seas, and the increase of anthropogenic chemical pollution is a major threat to its ecosystems. This thesis assesses the impact of harbors and sewage treatment plants on physiological traits and genetic structure of resident populations of blue mussels at replicated sites in the Baltic Sea. The initial evaluation of the overall genetic pattern in blue mussel populations in the Swedish West Coast, the Baltic Proper and the Bothnian Sea found genetic differentiation between the three water basins and a low genetic differentiation within each basin, especially within the Baltic Proper. Despite the low genetic differentiation among blue mussels within the Baltic Proper, a parallel genetic differentiation associated with sewage treatment plant effluents was found in this basin. This included genomic regions with a high degree of differentiation between reference sites and sites affected by sewage plants effluent. This genetic differentiation is suggested to be due to post-dispersal selection acting in each generation. In contrast, no parallel genetic differentiation was associated with harbors. We identified five genomic regions in blue mussels, showing strong signs of selection, shared among three out of four replicated reference sites and sites affected by sewage effluents in the Baltic Proper i.e. Askö, Tvärminne and Karlskrona. An initial characterization of these genomic regions revealed functions related to immune and endocrine responses, oxidative stress and shell formation. Our results indicate that selection caused by sewage effluents involves multiple loci. The same genomic regions are found across different locations in the Baltic Proper but there are also unique genomic regions at each location. No genotoxic or histopathological effects were found among blue mussels from sewage effluent-affected areas but a higher frequency of histological abnormalities in the digestive gland were observed in mussels from harbors.Evolutionära anpassningar till miljöstörningar i marina ekosystem: genetisk ekotoxikologi i Östersjön
3
Corriveau, Brit Madelaine. "The effects of natural and anthropogenic disturbances on the structure and composition of early-successional plant communities in the Interior Cedar-Hemlock (ICH) zone of southern British Columbia." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2285.
Full textAbstract:
Wildfire is the primary natural disturbance in Interior Cedar-Hemlock (ICH) forests, and since the mid-20th century, forest harvesting (clearcutting, in this case) has become the primary anthropogenic disturbance type. Forest management in British Columbia is currently governed by a paradigm that maintains that biological diversity can be preserved by utilizing forest harvesting regimes that closely mimic "natural" disturbance regimes, but a question remains as to how closely these regimes mimic wildfire disturbances. More specifically, how do clearcutting and wildfires compare in their effects on the structure and composition of early-successional ICH plant communities? This study compares vegetation structure, composition, relative abundance and diversity among 39 sites that experienced either a stand-replacing fire or a clearcut within the last 40 years. Sites of different ages and disturbance types were located within the wet cool ICHwkl and very-wet cool ICHvk I biogeoclimatic variants near Revelstoke, B.C. For each site, overstory structural characteristics (tree and snag diameters, basal area and density), overstory composition, and surface fuels (volume of coarse woody debris (CWD)) were assessed. Understory vegetation percent cover, species richness, composition and diversity were also determined. Linear regression analysis was used to examine differences in each of these variables between disturbance types, over time. The trends in structural legacies (especially snag and CWD dynamics) varied greatly between wildfire and clearcut sites. Compared to burned sites, clearcut sites exhibited patterns of accelerated succession in several characteristics (overstory tree regeneration, vegetation cover and understory species richness) due to planting treatments and pre-disturbance relicts. Understory species composition also varied between disturbances, with clearcut sites containing more shade-tolerant survivors initially. Both disturbance types had similar levels of floristic diversity during early succession. These results suggest that clearcut harvesting may not emulate stand-replacing fires in terms of impact on early ICH plant succession in any aspect but diversity. However, it is unclear if these early-successional differences will continue through time. There is a need for further research in this ecosystem, as well as any other ecosystems where emulation silviculture is applied, in order to confirm that silvicultural effects mimic those of natural disturbance regimes.
4
Kisaka, Lily. "Modelling payment systems for environmental services in the Mt Elgon ecosystem of Kenya." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1013123.
Full textAbstract:
Unsustainable patterns of consumption by humankind have increased the rate of change in the natural ecosystems and consequently the levels of stress experienced within the environment. Access to sufficient good quality water is essential and a requirement to meet a number of the Millennium Development Goals (MDGs). However, poor land management and untenable agricultural practices have become the main drivers of the declining watershed services. Upstream farmers often have little or no incentives to take these impacts into account in their decision-making process. Therefore, without investment in ensuring proper land management, the trend in watersheds degradation will continue. Payment for Environmental Services (PES) has emerged as an incentive–based tool that is expected to motivate farmers to improve their agricultural practices. PES is set up to facilitate the process whereby the beneficiaries of environmental services pay compensation to providers of environmental services for conserving the ecosystem. This tool has received increasing attention as a means of creating incentive measures for managing the ecosystem, addressing livelihood issues for the rural poor, and providing sustainable financing for protected areas. The Government of Kenya, as part of its efforts to improve water resource management, is considering use of economic incentive. However, there is insufficient information to guide policy making in that direction. Little is known about the farmers’ preferences for management schemes that will affect land use patterns, their willingness to accept compensation and the willingness of potential buyers to pay for the services. This study evaluates the willingness to accept and the willingness to pay for environmental services with a view to assessing the viability of a PES scheme for the Kuywa Watershed in particular, as well as the Mt. Elgon Ecosystem and other areas with similar conditions. The objectives of the study are threefold (i) to examine respondents preferences for management options for the provision of environmental services in the watershed of River Kuywa of Mt. Elgon Ecosystem; (ii) to evaluate households’ willingness to pay (WTP) and willingness to accept (WTA) payment for improved environmental services from the River Kuywa watershed; and (iii) to propose viable PES approaches for the management of the natural resource of the Kuywa watershed and the Mt. Elgon ecosystem in general. Using six land management attributes relevant to the local situation, the study applied the conjoint method to evaluate farmers’ preferences for management options for the provision of environmental service and assess farmers’ willingness to pay and willingness to accept payment for environmental services. To enable assessment of viability, an analysis was done of the institutional and legal framework within which the PES scheme would operate. Data were collected using literature review and document analysis, questionnaires, focus group discussions and key informant interviews. Results indicate that poor water quality was the most acute problem, followed by deforestation. Results from the conjoint models show that the length of commitment period and land size that is 40% or more of the total land holding influence the farmers’ rating of the management scenarios. The study found that a management contract that requires use of 20% of land holding for a period of 5 years, combined with a cash incentive, harvesting partially permitted, administered by a local NGO and requiring contribution of free labour for two days had the highest likelihood of being selected. The conjoint valuation exercise also came up with a WTA by farmers upstream of KSh. 7,080/= per year. The corresponding value downstream was KSh. 43/= per month over and above their regular water bill. In terms of the institutional and regulatory framework, Kenya has a wide range of policies, laws and regulation on water and other natural resources which provide an enabling environment for PES. With the decentralized institutional setup implemented in both the water sector and the agricultural sector, the institutional setting also provides an enabling environment for PES. With a positive WTA and WTP coupled with an enabling legal and institutional environment, the study concludes that PES is a viable environmental management tool for the Kuywa water shed and similar watersheds.
5
Pellecchia, Antonella. "Experimental analysis of the effects of extreme events of mechanical disturbance on rocky shore algal and invertebrate assemblages in the Bagnoli-Coroglio post-industrial area and in reference sites in the Gulf of Naples." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17977/.
Full textAbstract:
Among the various natural and anthropogenic threats to coastal systems, industrial activities and their heritage of local contamination play a key role, especially where new disturbances are superimposed to extant degraded conditions. This may affect the functioning of assemblages, including their ability to recover, in unpredictable ways. Organisms subject to chronic contamination may respond better to a present discrete disturbance compared to organisms from reference areas not affected by the same contamination due to their adaptation to harsh conditions. By contrast, the same organisms may be more sensitive to the new disturbance if chronic contamination kept them close to their tolerance limit. This study tested such alternatives by comparing the patterns of recovery from the experimental removal of all erect organisms of lowshore benthic assemblages between the post-industrial site of Bagnoli-Coroglio (Gulf of Naples) and reference sites located outside it. Recovery was assessed over six months. Response variables included mean values and temporal trajectories of assemblage structure, richness of taxa and abundance of conspicuous taxa. The examined assemblages showed great recovery ability that was comparable between the post-industrial site and reference sites. Discussed potential explanations include: (i) intertidal organisms would quickly recover irrespective of background contamination as an adaptation to the naturally harsh and variable environmental conditions of their living habitat; (ii) reference sites would be subject to environmental stress comparable to that of Bagnoli-Coroglio being located in the highly urbanized Gulf of Naples; (iii) large variability between- and withinsites may have masked any impacts of experimental disturbance and their differences between the post-industrial site and the reference sites; (iv) historical contamination would be limited to subtidal sediments, without propagating to adjacent rocky habitats.
6
Lewis, Jenny. "Body perception disturbance in complex regional pain syndrome." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/65409/.
Full textAbstract:
Complex regional pain syndrome (CRPS) is a painful, debilitating condition that is poorly understood. The syndrome is characterised by pain, motor disturbances and abnormalities in trophic, sudomotor, vascular temperature and sensation. The underlying mechanisms are unknown. Clinical observations have identified a novel phenomenon whereby patients pay little attention to, and fail to care for, their painful affected limb. The literature describes this phenomenon in terms of neglect-like symptoms similar to neurological neglect as described in stroke literature. However, this does not seem to fully fit with or explain the nature of clinical observations. Therefore the aim of the qualitative first study was to more fully describe the phenomenon through an investigation of the patient experience and words used to describe those experiences. Six themes emerged from the data and were as follows: hostile feelings; spectrum of disassociation; disparity between what is apparent and what is felt; distorted mental image of affected parts; awareness of limb position and conscious attention. From these findings a theory emerged which serves to further our understanding of body perception disturbance in CRPS. Based on these findings, the second study aimed to quantify a feature of body perception disturbance by measuring limb position accuracy of those with CRPS compared to Healthy Controls (HC) and those with Rheumatological Pain (RP). The CRPS group were significantly less accurate in positioning of both the affected and unaffected upper limbs (median=9°, Interquartile rang e (IQR), 5.7°-13.3°) compared to both HC (6.5°, IQR, 4°-10.7°) and RP groups (7.7°, IQR, 5 °-11.7°). In the CRPS group position accuracy of the affected limb significantly improved with vision (8.3° in view, 10.7° not in view). Pain intensity was significantly greater in the CRPS (6.5, IQR, 5.4-7.7) than the RP group (4.6, IQR, 3.6-5.7). Based on the findings of this research programme, a definition of body perception disturbance in CRPS is presented. Furthermore, a disrupted body schema model is proposed as an explanation of the central mechanisms responsible for body perception disturbance in CRPS.
7
Leitner, Zachary Robert. "Soil Biological Temporal Variability as Functions of Physiochemical States and Soil Disturbance." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/31620.
Full textAbstract:
Within our ecosystems, soil biota control an array of functions, such as nutrient cycling and decomposition, and have been pursued as a soil quality indicator. Though microbial communities are known to be a reflection of their environment, small scales dynamics within an agricultural system have been overlooked for many years leading to gaps when inferring on relative microbial values. To further asses our current microbial knowledge, two experiments analyzing microbial phospholipid fatty acid (PLFA) structures and enzyme activities sought out to determine temporal fluctuations, cycles, and driving force behind simulated daily microbial parameter outputs. Across both studies, temporal effects, cyclical structures, and common driving forces were recorded, but further validation and characterization is needed to solidify the temporal dynamics of the microbial community. Overall, this information serves as a valuable step towards determining the most viable tillage systems based on environmental conditions, and physical proof of small scale microbial fluctuations.
8
McCloskey, Shane P. J. "Western hemlock looper : a biological agent of disturbance in coastal forests of British Columbia." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31425.
Full textAbstract:
My dissertation examines western hemlock looper (Lambdina fiscellaria lugubrosa Hulst) as an agent of disturbance in coastal forests of British Columbia. Western hemlock looper populations along coastal British Columbia have undergone seven episodes of outbreak from 1911 to 2004, leading to visible defoliation of western hemlock (Tsuga heterophylla (Raf) Sarg.)-dominated forests. My research investigates the causal factors that influence the timing of outbreaks, the impacts the resultant defoliation has on forest structure and composition, and the spatio-temporal dimensions of this biological disturbance agent. In order to identify the specific antecedent climate conditions that contributed to western hemlock looper outbreaks between 1911 and 2003, I analyzed local meteorological records to develop a moisture stress index of combined temperature and precipitation data. This index included periods of warm, dry climate between 1895 and 2004, and I hypothesized that these warm, dry conditions would improve the survival of western hemlock looper larvae and facilitate population increases. Indeed, a high moisture stress index in June was associated with the onset of visible defoliation by western hemlock looper populations later that year. Furthermore, a high moisture stress index over the entire growing season (May to September) was associated with conditions two years before visible defoliation events, thereby providing a trigger for populations to increase to outbreak levels in subsequent years. Given predicted warmer and drier climatic conditions during the growing season in coastal British Columbia, I anticipate that the frequency of western hemlock looper outbreaks will increase in future. To quantify the impacts of defoliation on the structure and composition of the coastal forests, I compared the effects of three different levels of disturbance severity on stands with comparable tree composition, density, age and stand structure within the Coquitlam River watershed during a western hemlock looper outbreak from 2000-2003. I hypothesized that defoliation from western hemlock looper would slow the growth of canopy western hemlocks at sites with low levels of defoliation and lead to the death of canopy western hemlocks at sites with more severe defoliation. I found that the degree of canopy openness increased with disturbance severity and resulted in an increase in understory vascular plant diversity, I suggest that these alterations to forest structure and composition will lead to an increase in the number of possible future successional pathways and increase forest heterogeneity at the landscape level. In a second study of disturbance effects, I analyzed the temporal pattern of tree death and the resulting rates of mortality after the 2000-2003 western hemlock looper outbreak. I hypothesized that mortality of trees in defoliated areas would be influenced by tree diameter, with smaller trees more susceptible to defoliation and dying at a greater rate than larger trees. Using repeated census data, I was able to show species-specific responses in mortality following western hemlock looper outbreaks. Western hemlock had high levels of mortality across all diameter classes, while mortality of western redcedar and amabilis fir was confined to smaller trees. To determine if the frequency of western hemlock looper outbreaks changed over the past two centuries, I employed dendroentomological methods to reconstruct outbreaks that occurred on Coquitlam Island, a 75 ha island where three outbreaks had been documented during the 20th century. I used differential rates of tree-ring growth between 'host' western hemlock and 'non-host' western redcedar to detect periods of radial growth suppression associated with western hemlock looper outbreaks using the program OUTBREAK. I used known periods of western hemlock looper outbreaks in the 20th century to calibrate and verify the reconstruction techniques. I successfully reconstructed four outbreaks over a 135-year period between 1775 and 1910. The dendroentomological method was successful at identifying low, moderate and high severity outbreaks, whereas the written record identified only periods of visible defoliation from high severity outbreaks. Based on the reconstructed outbreaks, I have determined that the frequency of defoliations has not changed significantly over the past 200 years.Arts, Faculty of
Geography, Department of
Graduate
9
Villasenor, Jose Fernando. "HABITAT USE AND THE EFFECTS OF DISTURBANCE ON WINTERING BIRDS USING RIPARIAN HABITATS IN SONORA, MEXICO." The University of Montana, 2007. http://etd.lib.umt.edu/theses/available/etd-03282007-165836/.
Full textAbstract:
Riparian systems are important for breeding bird communities and are highly used as migratory corridors; however, their importance for wintering birds has not been assessed systematically. In order to assess the value of riparian areas for birds wintering in Sonora, data from 1,816 standard point counts were collected from 87 locations during January and February 2004-2006. A total of 253 species were detected across 14 vegetation types, including nine categories of riparian vegetation. The mean number of species and individuals detected per count was significantly higher in riparian vegetation than in non-riparian vegetation for migratory species, but not for residents. Riparian bird communities are different from those in non-riparian habitats, and contribute 22% of the regional avifauna's species.Anthropogenic disturbance has imposed significant changes in riparian habitats, and is known to have negative effects on biological communities. To assess the effects of human induced disturbance on wintering bird communities, I recorded community composition, relative abundance of species, and three indicators of bird condition in relatively undisturbed and highly disturbed sites at three river systems in Sonora. There is, in general, little effect of disturbance on the composition of wintering communities, with less than 20% of the most common species having significant differences in their abundances between relatively undisturbed and highly disturbed sites. Condition indicators were similar in the two disturbance levels, but the mean heterophil/lymphocyte ratio in the blood of sampled birds showed increased levels of physiological stress in disturbed sites. A more experimental approach is needed to determine the specific cause of the stress expression in leucocytes.
Modification of natural flooding regimes has modified riparian areas, as has been the case in the Colorado River Delta. I present a summary of the changes experienced by riparian systems and some of the measures implemented for riparian restoration in the southwestern United States, and then I compare the scenario with that in central Sonora, where some of the same stressors exist on riparian systems, but where traditional management practices have also mitigated some of the negative consequences of flow control along mid-sized river systems.
10
De, Blocq Van Scheltinga Andrew. "Disturbance effects of boat-based tourism on waterbirds at the Ramsar-designated De Hoop Vlei, Western Cape, South Africa." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25186.
Full textAbstract:
Recreation and ecotourism activities are growing in demand worldwide, especially in biodiversity hotspots. Protected area managers may seek to introduce novel activities in order to generate revenue. However, disturbance effects brought about through encounters between humans and wildlife can have negative consequences, which conflict with conservation goals. De Hoop Vlei is a large coastal lake within the De Hoop Nature Reserve. It is a Ramsar site as well as a key feature of a BirdLife Important Bird Area (IBA). Proposals for motorized boat tours and kayak tours on the vlei have been made, for which this study provides an impact assessment. Repeated counts were performed in order to characterize the waterbirds present during the high water level conditions required for boating. Birds were concentrated in areas with aquatic vegetation and shallow water, mainly along the vlei's western shoreline and southern and northern ends. Two routes were designed for boat tours that would minimize disturbance by avoiding these areas as well as breeding sites. Count data were also used to revise the Ramsar and IBA assessments, which underestimated the site's conservation value. Boat tours were monitored to estimate the number of birds disturbed, and to measure agitation distances (ADs) and flight initiation distances (FIDs) in response to the boat as well as a kayak. Post-disturbance recovery was investigated, as was the likelihood of habituation using a space-for-time substitution at a site with regular boat traffic. Boat tours did not typically disturb more than 10% of birds present at the vlei, and largely avoided disturbing species of conservation concern. Responses to the kayak were more severe than to the boat, which is most likely due to the similar speeds of the two boats are similar and the kayak is more easily perceived as a threat due to its shape and stealth, the presence of a paddler, and the consistent paddling motion. Post-disturbance recovery of species was slow and incomplete after an hour, meaning that there are likely costs for foraging opportunities and breeding if important areas are disturbed. Most species did allow a closer approach at the site with regular boating, but AD did not differ between them for most species. From these results it would be dangerous to assume that habituation will mitigate against disturbance impacts. Recommendations made included that kayak tours should not be permitted. Boat tours, with correct management, can be conducted in a manner that will not be too disruptive to birds. This study is the first to document such a large difference in responses of birds to two differing boat types, and is a rare example of disturbance of birds being studied in an African context.
Books on the topic "Biological disturbances"
1
Menstrual disorders and menopause: Biological, psychological, and cultural research. New York: Praeger, 1985.
Find full text
2
Secades, Cristina. Earth observation for biodiversity monitoring: A review of current approaches and future opportunities for tracking progress towards the Aichi biodiversity targets. Montréal, Québec: Secretariat of the Convention on Biological Diversity, 2014.
Find full text
3
Veste, Maik, Vincent John Martin Noah Linus Felde, Steven D. Warren, and Nicole Pietrasiak, eds. Ecological Development and Functioning of Biological Soil Crusts After Natural and Human Disturbances. Frontiers Media SA, 2021. http://dx.doi.org/10.3389/978-2-88971-255-7.
Full text
4
The aliens among us: How invasive species are transforming the planet--and ourselves. Yale University Press, 2017.
Find full text
6
Beever, Erik A., Suzanne Prange, and Dominick A. DellaSala, eds. Disturbance Ecology and Biological Diversity. CRC Press, 2019. http://dx.doi.org/10.1201/9780429095146.
Full text
7
Beever, Erik A., Dominick A. DellaSala, and Suzanne Prange. Disturbance Ecology and Biological Diversity. Taylor & Francis Group, 2019.
Find full text
8
Jacobsen, Dean, and Olivier Dangles. A growing human footprint in the highlands. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198736868.003.0009.
Full textAbstract:
Chapter 9 reviews the threats imposed by human activities to aquatic life at high altitude. High altitude regions of the inter-tropical belt are generally much more densely populated than their temperate counterparts. Therefore, they are directly affected by a number of human-related disturbances such as land use changes, water contamination, use and diversion, and the introduction of invasive species. The chapter details several unique environmental conditions of high altitude environments that make their aquatic biota particularly at risk in the face of anthropogenic disturbances. Among others, glaciers concentrate pollutants, low oxygen concentrations affect the response of aquatic fauna to stress, ultraviolet B modifies the bioavailability of contaminants, high primary productivity of grasslands encourages cattle ranching and fuels fires over large scales, and isolated watersheds favour species extinction following biological invasions.
9
Beever, Erik A., Dominick A. DellaSala, and Inger Suzanne Prange. Disturbance Ecology and Biological Diversity: Context, Nature, and Scale. Taylor & Francis Group, 2019.
Find full text
10
Beever, Erik A., Dominick A. DellaSala, and Inger Suzanne Prange. Disturbance Ecology and Biological Diversity: Context, Nature, and Scale. Taylor & Francis Group, 2019.
Find full textBook chapters on the topic "Biological disturbances"
1
Hellawell, J. M. "Effects of Physical Disturbances." In Biological Indicators of Freshwater Pollution and Environmental Management, 99–154. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4315-5_5.
Full text
2
Banki, Csaba M., Mihály Arató, and Zsuza Papp. "Metabolic Disturbances in Psychiatric Disorder: The Question of Diagnostic Specificity." In Biological Psychiatry, Higher Nervous Activity, 187–92. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4684-8329-1_25.
Full text
3
Bruinvels, Jacques, and Lolke Pepplinkhuizen. "Disturbances in Serine-Glycine Metabolism in Relation to Acute Psychoses with Psychedelic Symptoms." In Biological Psychiatry, Higher Nervous Activity, 193–95. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4684-8329-1_26.
Full text
4
van Praag, H. M., R. S. Kahn, G. M. Asnis, S. Wetzler, S. L. Brown, A. Bleich, and M. L. Korn. "Beyond Nosology in Biological Psychiatry. 5-HT Disturbances in Mood, Aggression and Anxiety Disorders." In New Concepts in Depression, 96–119. London: Macmillan Education UK, 1988. http://dx.doi.org/10.1007/978-1-349-09506-3_8.
Full text
5
Cleare, A. J. "Regulatory Disturbance of Energy." In Everyday Biological Stress Mechanisms, 17–34. Basel: KARGER, 2001. http://dx.doi.org/10.1159/000059273.
Full text
6
de Bakker, E., M. C. E. van Leeuwen, O. W. M. Meijer, and F. B. Niessen. "Additional Invasive Techniques in Scar Management." In Textbook on Scar Management, 343–49. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44766-3_40.
Full textAbstract:
AbstractRadiation therapy is a last resort option for recurring and therapy-resistant keloid scars. It represents a significant burden to the patient and both financially and logistically to the healthcare system. Radiation therapy yields excellent results, both functionally and aesthetically and in low recurrence rates. An efficacious treatment protocol consists of excision of the entire keloid, followed by rapid administration of the first radiation dose. The most commonly used techniques are external radiation, low-dose-rate brachytherapy, and high-dose-rate brachytherapy. Brachytherapy is associated with fewer side effects and a lower recurrence rate in comparison with external radiation. The use of high-dose-rate brachytherapy is more convenient because it allows an outpatient setting and prevents unnecessary radiation damage to the surrounding tissue. Although more research is needed, a biological effective dose (BED) of 20–30 Gy, for example, 2 × 6 Gy, seems sufficient for most cases. The most commonly seen complications are erythema, temporary and permanent pigmentation disturbances, and telangiectasia. Although it is necessary to mention the risk of inducing secondary malignancy in the treated area, only a few cases have been described, out of which none were caused by brachytherapy.
7
Graziottin, Alessandra, Elisa Maseroli, and Linda Vignozzi. "Female Sexual Dysfunctions: A Clinical Perspective on HSDD, FAD, PGAD, and FOD." In Practical Clinical Andrology, 89–112. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-11701-5_8.
Full textAbstract:
AbstractThe multidimensionality and interpersonal dimension of human sexuality make the study of female sexual dysfunction (FSD) a challenge. The aspiration to pursue a patient-centered, holistic approach collides with the need to establish commonly accepted diagnostic criteria for different disturbances in sexual functioning, involving one or multiple phases of the sexual response cycle and pain associated with sexual activity. According to recently proposed classifications, which are continuously evolving, the most relevant FSDs include hypoactive sexual desire disorder, female arousal disorder, persistent genital arousal disorder, and female orgasm disorder. The present chapter aims to provide a clinical perspective on these disorders by reviewing the most recent evidence on the pathophysiology, definitions, prevalence, leading etiologies, diagnostic tools, and key therapeutic approaches. Sexual pain-related conditions will be reviewed in another chapter.It is evident that a gender bias still exists, with prominent biological etiologies of FSDs being neglected and understudied at the expense of psychodynamic and relational determinants. Moreover, classifications should serve to advocate the advancement of our knowledge of female sexual functioning. This process goes through the practical translation of the updated nosology in a language that is intelligible to primary healthcare providers all over the world, and ultimately, to women.
8
Belnap, J., and D. Eldridge. "Disturbance and Recovery of Biological Soil Crusts." In Ecological Studies, 363–83. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-56475-8_27.
Full text
9
Ottosson, Jan-Otto, and Kurt Widepalm. "Memory Disturbance After Ect in Low-Pressure Narcosis." In Biological Psychiatry, Higher Nervous Activity, 583–88. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4684-8329-1_86.
Full text
10
Burn, John. "Disturbance of Morphological Laterality in Humans." In Ciba Foundation Symposium 162 - Biological Asymmetry and Handedness, 282–99. Chichester, UK: John Wiley & Sons, Ltd., 2007. http://dx.doi.org/10.1002/9780470514160.ch16.
Full textConference papers on the topic "Biological disturbances"
1
Moshkovsky, A. N., Galina P. Petrova, N. N. Sysoev, and A. P. Ryazin. "Study of shock propagation: acoustic disturbances induced by laser radiation in model biological systems." In ALT '96 International Symposium: Laser Methods for Biomedical Applications, edited by Alexander M. Prokhorov, Costas Fotakis, and Vladimir Pustovoy. SPIE, 1996. http://dx.doi.org/10.1117/12.257380.
Full text
2
Lengua, Ismael, Guillermo Peris-Fajarnés, Beatriz Defez García, Juan José Vila Carbo, and María Moncho Santonja. "Capture and analysis of autofluorescence in biological tissues for identification and demarcation of lesions." In INNODOCT 2018. València: Editorial Universitat Politècnica de València, 2018. http://dx.doi.org/10.4995/inn2018.2018.8914.
Full textAbstract:
In certain cell types substances called Chromophores are found. These substances are responsible of a particular way to the incidence of a specific light. Specifically, chromophores are responsible for the autofluorescence of certain cells. This work shows how the use of lighting techniques and image filtering take advantage of these properties in order to distinguish, even in tissues formed by the same cells, disturbances that are not perceptible under standard lighting conditions.In the paper, we explain how these techniques could improve certain surgical procedures, allowing the surgeon to have more complete and detailed information during the intervention itself.
3
Prokopov, I. I., P. M. Shonazarov, S. N. Darovskikh, and N. N. Gudaev. "Hardware and software tools for modeling solar microwave radiation and natural magnetospheric disturbances." In III All-Russian Scientific Conference with International Participation "Science, technology, society: Environmental engineering for sustainable development of territories". Krasnoyarsk Science and Technology City Hall, 2022. http://dx.doi.org/10.47813/nto.3.2022.6.242-249.
Full textAbstract:
The relevance of the study of the evolutionary mechanisms of the interaction of objects of animate and inanimate nature with various types of radiation and fields, the source of which is the Sun, is substantiated. Conducting such studies is currently difficult due to the growing level of electromagnetic pollution of the environment. This does not allow carrying out experimental studies using real natural radiations and fields. They are possible only with the use of specialized hardware and software devices for their simulation. The presented materials of the article reflected the description of the original hardware and software tools for modeling the microwave radiation of the Sun and natural magnetospheric disturbances. When developing these devices, modern ideas about the frequency-time structure of radiation and fields of natural origin were used. The already existing positive experience of using the device for simulating solar microwave radiation in assessing the interaction of radiation generated by it with biological objects was also noted. First of all, it is associated with a decrease in the resistance properties of microorganisms, disaggregation of erythrocytes, etc. Such results, according to the authors, are associated with excitation in biological structures under the influence of natural radiation of elastic vibrations. They are also possible in the study of abiogenic materials. The features of their excitation when using natural radiations and fields are determined. The results of research using the developed hardware and software tools can be used as the basis for the creation of new technologies for reducing the influence of the technogenic factor on the life process of organisms. They will also find application in the development of methods for the synthesis of new abiogenic structures.
4
Kemper, Björn, Alvaro Barroso, Steffi Ketelhut, Lena Kastl, Jürgen Schnekenburger, and Peter Heiduschka. "Hyperspectral digital holographic microscopy approach for reduction of coherence induced disturbances in quantitative phase imaging of biological specimens." In SPECKLE 2018: VII International Conference on Speckle Metrology, edited by Michal Józwik, Leszek R. Jaroszewicz, and Malgorzata Kujawińska. SPIE, 2018. http://dx.doi.org/10.1117/12.2319179.
Full text
5
"Hepatoprotective Effect of Typhonium flagelliforme against Thioacetamide Induced Liver Cirrhosis in Rats." In 4th International Conference on Biological & Health Sciences (CIC-BIOHS’2022). Cihan University, 2022. http://dx.doi.org/10.24086/biohs2022/paper.643.
Full textAbstract:
Typhonium flagelliforme (T. flagelliforme) was utilized in outdated medication for handling numerous syndromes. This study aimed to investigate hepatoprotection effects of T. flagelliforme against thioacetamide (TAA) hepatotoxicity in rodents.Thirty rodents arbitrarily separated five clusters. Collection 1 was intraperitoneally injected distilled water thrice /week and fed (p.o) daily with 10% Tween 20 to eight weeks. Collection 2-5 i.p. injected with 200 mg/kg TAA three times thrice per week for 8 weeks and fed 10% Tween 20, 50 mg/kg silymarin, 250 and 500 mg/kg of T. flagelliforme extract daily for 8 weeks, respectively.Hepatotoxic assembly showed suggestively rise hepatic biochemistry markers together with a considerable lessening of proteins and albumin compared to normal assemblage. The hepatotoxic group displayed decreased catalase and superoxide dismutase activities and increase lipid peroxidation. Macroscopy of hepatotoxic liver exhibited irregular, rough surface with micro and macro nodules, and histopathology-stained Hematoxylin and Eosin, and Masson’s Trichome exhibited inflammation infiltration of lymphocytes, focal necrosis, fibrosis, and bile duct propagation.T. flagelliforme fed clusters have expressively reduced TAA toxicity in gross and histology as designated by fewer disturbances of hepatic tissue, slight fibrosis, and low-grade cells infiltration. Thus, our results showed that the hepatoprotective effect of this plant might be due to reduce toxicity, inhibition of hepatocytes proliferation, decrease enzyme markers, increase protein and albumin, increased endogenous enzymes, and reduced lipid peroxidation level.
6
Zhang, Muheng, and Yongsheng Lian. "Numerical Investigation of the Coulter Principle in a Microfluidic Device." In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16011.
Full textAbstract:
Coulter counters are analytical microfluidic instrument used to measure the size and concentration of biological cells or colloid particles suspended in electrolyte. The underlying working mechanism of Coulter counters is the Coulter principle which relies on the fact that when low-conductive cells pass through an electric field these cells cause disturbances in the measurement (current or voltage). Useful information about these cells can be obtained by analyzing these disturbances if an accurate correlation between the measured disturbances and cell characteristics. In this paper we use computational fluid dynamics method to investigate this correlation. The flow field is described by solving the Navier-Stokes equations, the electric field is represented by a Laplace’s equation in which the conductivity is calculated from the Navier-Stokes equations, and the cell motion is calculated by solving the equations of motion. The accuracy of the code is validated by comparing with analytical solutions. The study is based on a coplanar Coulter counter with three inlets that consist of two sheath flow inlet and one conductive flow inlet. The effects of diffusivity, cell size, sheath flow rate, and cell geometry are discussed in details. The impacts of electrode size, gap between electrodes and electrode location on the measured distribution are also studied.
7
Bacle, A., B. Hue, C. Lebert, B. Troussier, P. Le Corre, and V. Gicquel. "NP-001 Patients with multiple sclerosis treated with high doses of biotin: prevention of significant biological examination disturbances by hospital pharmacists." In 24th EAHP Congress, 27th–29th March 2019, Barcelona, Spain. British Medical Journal Publishing Group, 2019. http://dx.doi.org/10.1136/ejhpharm-2019-eahpconf.626.
Full text
8
Rosado, Magda, Lucinda Carvalho, and André Coelho. "Evaluation of the association between drug use and sleep quality in shift workers vs daytime workers." In II INTERNATIONAL SEVEN MULTIDISCIPLINARY CONGRESS. Seven Congress, 2023. http://dx.doi.org/10.56238/homeinternationalanais-090.
Full textAbstract:
Abstract Sleep is a physiological process and a fundamental biological function for human survival1. Disturbances in its quality can trigger significant changes in the quality of life of the individual2 . The quality of sleep can be influenced by several factors, such as: previous medical conditions, the consumption of medications and/or stimulant substances, working hours, among others3. The use of medication to alleviate sleep disorders caused by working hours is common; however, if abused and unsupervised, it can trigger new pathological conditions4. On the other hand, when prescribing medications for several pathologies, it is common to neglect their adverse effects on sleep
9
Corbett, Scott C., Neil Verma, Parnian Boloori Zadeh, Ahmet U. Coskun, and Hamid N.-Hashemi. "Characterization of a Novel Polymeric Trileaflet Heart Valve Prosthesis." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-203817.
Full textAbstract:
While heart valve prostheses have been used successfully since 1960, 10-year survival rates still range from 37–58% [1]. The underlying problem with bioprostheses is a limited life from structural changes such as calcification and leaflet wear, leading to valve failure [2]. Biological tissue fixation and methods used to mount the tissue to a supporting stent can be blamed for this shortcoming. The underlying problem with mechanical heart valves is the presence of a centrally located leaflet, or occluder. It propagates high velocity jets, turbulence and areas of stagnation: the disturbances which necessitate anticoagulation [3]. A polyurethane valve has the potential to improve upon the shortcomings of existing valves and ultimately improve patient survival.
10
Chatterjee, Abheek, and Astrid Layton. "Bio-Inspired Human Network Design: A Multi-Currency Robustness Metric Inspired by Ecological Network Analysis." In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-98235.
Full textAbstract:
Abstract The Ecological Network Analysis (ENA) metric ecological robustness quantifies the unique balance that biological food webs have between their pathway efficiency and redundancy, enabling them to maximize their robustness to system disturbances. This robustness is a potentially desirable quality for human systems to mimic. Modeling the interactions between actors in human networks as predator-prey type exchanges (of a medium or currency rather than caloric exchanges) enables an ENA analysis. ENA has been shown to be a useful tool in improving the design of human networks because it allows the characteristics of biological networks to be mimicked. The application of these metrics is, however, limited to networks with only one flow type. Human networks are composed of many different types of flow interactions and thus a biologically-inspired indicator of total system robustness must take into account all of these interactions. This work further develops the traditional ENA ecological robustness metric to accommodate various flows between actors in multi-currency human networks. Two novel methods for quantifying multi-currency flow network robustness are introduced. The mathematical formulation for these new metrics is presented. The water network for the Kalundborg Eco-Industrial Park (EIP) is used as a case study to determine the benefits of the proposed robustness metrics. The results obtained using the single-currency robustness and the two multi-currency robustness metrics are compared using the case study. Based on the analysis of the results obtained at the system level, as well as at the sub-levels, both multi-currency metrics showed the ability to predict systems characteristics for the multi-currency Kalundborg EIP. While both of these are promising, more research regarding these metrics is needed in order to develop an elegant and comprehensive total system robustness metric.
Reports on the topic "Biological disturbances"
1
Smith, John G., and Arthus J. Stewart. SERDP SEED Project (CS-1161) Final Report: Feasibility Study: Lab-on-a-chip and In Situ Bioassay Techniques for Rapid Resolution of Ion Signatures for Disturbances of Biological Significance in Streams. Fort Belvoir, VA: Defense Technical Information Center, December 2000. http://dx.doi.org/10.21236/ada385396.
Full text
2
Jones, Robert, Molly Creagar, Michael Musty, Randall Reynolds, Scott Slone, and Robyn Barbato. A 𝘬-means analysis of the voltage response of a soil-based microbial fuel cell to an injected military-relevant compound (urea). Engineer Research and Development Center (U.S.), November 2022. http://dx.doi.org/10.21079/11681/45940.
Full textAbstract:
Biotechnology offers new ways to use biological processes as environmental sensors. For example, in soil microbial fuel cells (MFCs), soil electro-genic microorganisms are recruited to electrodes embedded in soil and produce electricity (measured by voltage) through the breakdown of substrate. Because the voltage produced by the electrogenic microbes is a function of their environment, we hypothesize that the voltage may change in a characteristic manner given environmental disturbances, such as the contamination by exogenous material, in a way that can be modelled and serve as a diagnostic. In this study, we aimed to statistically analyze voltage from soil MFCs injected with urea as a proxy for gross contamination. Specifically, we used 𝘬-means clustering to discern between voltage output before and after the injection of urea. Our results showed that the 𝘬-means algorithm recognized 4–6 distinctive voltage regions, defining unique periods of the MFC voltage that clearly identify pre- and postinjection and other phases of the MFC lifecycle. This demonstrates that 𝘬-means can identify voltage patterns temporally, which could be further improve the sensing capabilities of MFCs by identifying specific regions of dissimilarity in voltage, indicating changes in the environment.
3
Costa, Daniel P. Development of the PCAD Model to Assess Biological Significance of Acoustic Disturbance. Fort Belvoir, VA: Defense Technical Information Center, September 2013. http://dx.doi.org/10.21236/ada602516.
Full text
4
Costa, Daniel P. Development of the PCAD Model to Assess Biological Significance of Acoustic Disturbance. Fort Belvoir, VA: Defense Technical Information Center, September 2014. http://dx.doi.org/10.21236/ada617696.
Full text
5
Williams, Terrie M. High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences. Fort Belvoir, VA: Defense Technical Information Center, September 2013. http://dx.doi.org/10.21236/ada602529.
Full text
6
Bingham, Sonia, and Craig Young. Sentinel wetlands in Cuyahoga Valley National Park: I. Ecological characterization and management insights, 2008–2018. Edited by Tani Hubbard. National Park Service, February 2023. http://dx.doi.org/10.36967/2296885.
Full textAbstract:
Sentinel wetlands at Cuyahoga Valley National Park (NP) comprise a set of twenty important management areas and reference sites. These wetlands are monitored more closely than other wetlands in the wetlands monitoring program and are the focus of the volunteer monitoring program for water levels. We used the Ohio Rapid Assessment Method (ORAM) to evaluate habitat in the sentinel wetlands. A total of 37 long-term sample plots have been established within these wetlands to monitor biological condition over time using vegetation as an indicator. Vegetation is intensively surveyed using the Vegetation Index of Biotic Integrity (VIBI), where all plant species within the plot are identified to the lowest taxonomic level possible (genus or species). Sample plots were surveyed twice from 2008 to 2018 and the vegetation data were evaluated using five metrics: VIBI, Floristic Quality Assessment Index (FQAI), percent sensitive plant species, percent invasive graminoids, and species richness. These metrics are discussed for each location. This report also highlights relevant land use histories, common native plant species, and invasive species of concern at each wetland. This is the first report in a two-part series, designed to summarize the results from intensive vegetation surveys completed at sentinel wetlands in 2008–2018. Boston Mills, Virginia Kendall Lake, Stumpy Basin, Columbia, and Beaver Marsh are all in excellent condition at one or more plots. They have unique habitats with some specialized plant species. Fawn Pond is in good condition at most plots and scores very high in comparison to other wetlands within the riverine mainstem hydrogeomorphic class. Metric scores across mitigation wetlands were low. Two of the three wetlands (Brookside and Rockside) are not meeting the benchmarks originally established by the United States Army Corps of Engineers and Ohio Environmental Protection Agency. Krejci is still a young mitigation site and success will be determined over time. Park-supported invasive species control efforts will be crucial for long-term success of these sites and future mitigation/restoration projects. The wetlands monitored because of proposed ecological restoration projects (Pleasant Valley, Stanford, and Fawn Pond) have extensive invasive plant communities. These restoration sites should be re-evaluated for their feasibility and potential success and given an order of prioritization relative to the newer list of restoration sites. Cuyahoga Valley NP has added many new areas to their list of potential wetland restoration sites after these areas were selected, and there may be better opportunities available based on restoration objectives. Restoration goals should be based on the park's desired future conditions, and mitigation goals of outside partners may not always be in line with those. The multiple VIBI plots dispersed throughout the large wetlands at Cuyahoga Valley NP detected and illuminated spatial patterns in condition. Many individual wetlands had a wide range of VIBI scores within their boundaries, sometimes reflecting localized disturbances, past modifications, and management actions. Most often, these large fluctuations in condition were linked to local invasive plant infestations. These infestations appear to be the most obvious and widespread threat to wetland ecosystems within the park, but also the most controllable threat. Some sensitive species are still present in some of the lowest scoring plots, which indicates that invasive plant species control efforts may pay off immediately with a resurgence of native communities. Invasive plant control at rare habitat sites would have large payoffs over time by protecting some of the park's most unique wetlands. Reference wetlands would also be good demonstration sites for park managers to try to maintain exemplary conditions through active management. Through this work, park managers can evaluate the feasibility, effectiveness, and scalability of management practices required to maintain wetland condition.
7
Muxo, Robert, Kevin Whelan, Raul Urgelles, Joaquin Alonso, Judd Patterson, and Andrea Atkinson. Biscayne National Park colonial nesting birds monitoring protocol—Version 1.1. National Park Service, January 2022. http://dx.doi.org/10.36967/nrr-2290141.
Full textAbstract:
Breeding colonies of wading birds (orders Ciconiiformes, Pelecaniformes) and seabirds (orders Suliformes, Pelecaniformes) serve as important indicators of aquatic ecosystem health, as they respond to changes in food abundance and quality, contaminants, invasive species, and disturbance. The Comprehensive Everglades Restoration Plan, Restoration Coordination & Verification program (CERP-RECOVER) has identified wading-bird colonies as an important ecosystem restoration indicator. The National Park Service South Florida/Caribbean Inventory & Monitoring Network (SFCN) ranked colonial nesting birds eighth out of 44 vital signs of park natural resource conditions for ecological significance and feasibility. However, while large-scale monitoring efforts are occurring in the rest of the Greater Everglades Ecosystem, only minimal historic data collection and no extensive ongoing monitoring of wading bird and seabird nesting have occurred in Biscayne National Park. Consequently, due to their high importance as biological indicators and because they are a gap occurring in regional monitoring efforts, the network has initiated a monitoring program of colonial nesting birds in Biscayne National Park. This protocol provides the rationale, approach, and detailed Standard Operating Procedures for annual colonial bird monitoring within and close to Biscayne National Park and conforms to the Oakley et al. (2003) guidelines for National Park Service long-term monitoring protocols. The specific objectives of this monitoring program are to determine status and long-term trends in: Numbers and locations of active colonies of colonial nesting birds with a special focus on Double-crested Cormorants, Great Egrets, Great White Herons, Great Blue Herons, White Ibises, and Roseate Spoonbills. Annual peak active nest counts of colonial nesting birds in Biscayne National Park with a special focus on the species mentioned above. An annual nesting index (i.e., sum of monthly nest counts) with a special focus on the species mentioned above. Timing of peak nest counts for the focal species.
8
Weissinger, Rebecca. Evaluation of hanging-garden endemic-plant monitoring at Southeast Utah Group national parks, 2013–2020. Edited by Alice Wondrak Biel. National Park Service, October 2022. http://dx.doi.org/10.36967/2294868.
Full textAbstract:
Hanging gardens are the most common type of spring at Arches National Park (NP) and Natural Bridges National Monument (NM). They are also present at Canyonlands National Park, but hanging gardens are rare off the Colorado Plateau. Their cliffside setting provides stable access to water without flood disturbance. This combination provides unique habitat that is rich in endemic plant species. The diffuse, seeping emergence of water makes measuring springflow impossible at most sites. Park managers have an interest in monitoring hanging gardens—especially as the climate warms and aridity and water demand both increase. The Northern Colorado Plateau Net-work (NCPN) proposed methods for monitoring seven perennial endemic-plant species at hanging gardens as indicators of spring health and proxies for water availability. Because hanging gardens occur on bedrock outcrops, systematic or random sampling was not possible due to safety concerns and potential resource damage on steep, wet slopes. Examining eight years (2013–2020) of data, this report evaluates the suitability of endemic-plant count data at hanging gardens as a monitoring indicator. It also provides our first evaluation of status and trends at NCPN hanging gardens. The seven species included in monitoring were Rydberg’s thistle (Cirsium rydbergii), Kachina daisy (Erigeron kachinensis), alcove death camas (Zigadenus vaginatus), alcove bog orchid (Habenaria zothecina), cave primrose (Primula specuicola), alcove columbine (Aquilegia micrantha), and Eastwood’s monkeyflower (Mimulus eastwoodiae). Six of the seven species were found at each park. Up to 500 individuals of each species were counted at 42 hanging gardens in Arches NP, 14 hanging gardens in Natural Bridges NM, and 3 hanging gardens in Canyonlands NP. Larger populations were divided into count classes of 501–1,000, 1,001–10,000, and more than 10,000 individuals. Counts from two independent observers and from back-to-back years of sampling were compared for repeatability. Repeatability in count classes was less than 50% for Kachina daisy and Eastwood’s monkeyflower, which both propagate vegetatively via ramets and/or stolons. Repeatability was greater than 90% for only one species, Rydberg’s thistle. The remaining species were categorized in different classes between 15–40% of the time. Independent-observer comparisons were only available for 6.6% of the dataset, but these observations suggested that (1) observer bias was present and (2) the observer with more experience working in hanging gardens generally had higher counts than the observer with less experience in this system. Although repeatability was variable, it was within the range reported by other studies for most species. The NCPN, in discussion with park staff, has elected to make some modifications to the protocol but will continue using endemic plant counts as an indicator of hanging-garden health to maintain a biological variable as a complement to our physical-response data. This is due to their high value to park biodiversity and the difficulty of developing a more robust approach to monitoring in these sites. Endemic-plant monitoring will continue for the five species with the highest repeatability during pilot monitoring and will focus on detecting changes in smaller populations. Most hanging gardens have more than one endemic species present, so several populations can be tracked at each site. Our period of record is relatively brief, and the distribution of endemic-plant populations in different count classes at these sites has not yet shown any statistical trends over time. Be-cause of the large count classes, our methods are more sensitive to showing change in smaller populations (fewer than 500 individuals). Small populations are also of greatest concern to park managers because of their vulnerability to declines or extirpation due to drought. Over-all, more sites had endemic-plant populations of fewer than 100 individuals at the end...