888 resultados para Statherian and Calymmian extension events
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TORT, A. B. L. ; SCHEFFER-TEIXEIRA, R ; Souza, B.C. ; DRAGUHN, A. ; BRANKACK, J. . Theta-associated high-frequency oscillations (110-160 Hz) in the hippocampus and neocortex. Progress in Neurobiology , v. 100, p. 1-14, 2013.
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Une caractéristique intéressante de la protéine Bcl-xL est la présence d'un domaine en boucle non-structurée entre les hélices α1 and α2 de la protéine. Ce domaine protéique n'est pas essentiel pour sa fonction anti-apoptotique et absent chez CED-9, la protéine orthologue chez Caenorhabditis elegans. A l'intérieur de ce domaine, Bcl-xL subit une phosphorylation et déphosphorylation dynamique sur les résidus Ser49 et Ser62 en phase G2 du cycle cellulaire et lors de la mitose. Lorsque ces résidus sont mutés et les protéines exprimées dans des cellules cancéreuses, les cellules démontrent plusieurs défauts mitotiques liés à l'instabilité chromosomique. Pour analyser les effets de Bcl-xL Ser49 et Ser62 dans les cellules normales, les présentes études ont été réalisées dans des cellules diploïdes humaines normales, et in vivo chez Caenorhabditis elegans. Dans une première étude, nous avons utilisé la lignée cellulaire de cellules fibroblastiques diploïdes humaines normales BJ, exprimant Bcl-xL (type sauvage), (S49A), (S49D), (S62A), (S62D) et les double (S49/62A) et (S49/62D) mutants. Les cellules exprimant les mutants de phosphorylation ont montré des cinétiques de doublement de la population cellulaire réduites. Ces effets sur la cinétique de doublement de la population cellulaire corrèle avec l'apparition de la sénescence cellulaire, sans impact sur les taux de mort cellulaire. Ces cellules sénescentes affichent des phénotypes typiques de sénescence associés notamment à haut niveau de l'activité β-galactosidase associée à la sénescence, la sécrétion d' interleukine-6, l'activation de p53 et de p21WAF1/ Cip1, un inhibiteur des complexes kinase cycline-dépendant, ainsi que la formation de foyers de chromatine nucléaire associés à γH2A.X. Les analyses de fluorescence par hybridation in situ et des caryotypes par coloration au Giemsa ont révélé que l'expression des mutants de phosphorylation de Bcl-xL provoquent de l'instabilité chromosomique et l'aneuploïdie. Ces résultats suggèrent que les cycles de phosphorylation et déphosphorylation dynamiques de Bcl-xL Ser49 et Ser62 sont importants dans le maintien de l'intégrité des chromosomes lors de la mitose dans les cellules normales. Dans une deuxième étude, nous avons entrepris des expériences chez Caenorhabditis elegans pour comprendre l'importance des résidus Ser49 et Ser62 de Bcl-xL in vivo. Les vers transgéniques portant les mutations de Bcl-xL (S49A, S62A, S49D, S62D et S49/62A) ont été générés et leurs effets ont été analysés sur les cellules germinales des jeunes vers adultes. Les vers portant les mutations de Bcl-xL ont montré une diminution de ponte et d'éclosion des oeufs, des variations de la longueur de leurs régions mitotiques et des zones de transition, des anomalies chromosomiques à leur stade de diplotène, et une augmentation de l'apoptose des cellules germinales. Certaines de ces souches transgéniques, en particulier les variants Ser/Ala, ont également montré des variations de durée de vie par rapport aux vers témoins. Ces observations in vivo ont confirmé l'importance de Ser49 et Ser62 à l'intérieur du domaine à boucle de Bcl-xL pour le maintien de la stabilité chromosomique. Ces études auront une incidence sur les futures stratégies visant à développer et à identifier des composés qui pourraient cibler non seulement le domaine anti-apoptotique de la protéine Bcl-xL, mais aussi son domaine mitotique pour la thérapie du cancer.
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In the recent years, vibration-based structural damage identification has been subject of significant research in structural engineering. The basic idea of vibration-based methods is that damage induces mechanical properties changes that cause anomalies in the dynamic response of the structure, which measures allow to localize damage and its extension. Vibration measured data, such as frequencies and mode shapes, can be used in the Finite Element Model Updating in order to adjust structural parameters sensible at damage (e.g. Young’s Modulus). The novel aspect of this thesis is the introduction into the objective function of accurate measures of strains mode shapes, evaluated through FBG sensors. After a review of the relevant literature, the case of study, i.e. an irregular prestressed concrete beam destined for roofing of industrial structures, will be presented. The mathematical model was built through FE models, studying static and dynamic behaviour of the element. Another analytical model was developed, based on the ‘Ritz method’, in order to investigate the possible interaction between the RC beam and the steel supporting table used for testing. Experimental data, recorded through the contemporary use of different measurement techniques (optical fibers, accelerometers, LVDTs) were compared whit theoretical data, allowing to detect the best model, for which have been outlined the settings for the updating procedure.
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This paper presents a discrete formalism for temporal reasoning about actions and change, which enjoys an explicit representation of time and action/event occurrences. The formalism allows the expression of truth values for given fluents over various times including nondecomposable points/moments and decomposable intervals. Two major problems which beset most existing interval-based theories of action and change, i.e., the so-called dividing instant problem and the intermingling problem, are absent from this new formalism. The dividing instant problem is overcome by excluding the concepts of ending points of intervals, and the intermingling problem is bypassed by means of characterising the fundamental time structure as a well-ordered discrete set of non-decomposable times (points and moments), from which decomposable intervals are constructed. A comprehensive characterisation about the relationship between the negation of fluents and the negation of involved sentences is formally provided. The formalism provides a flexible expression of temporal relationships between effects and their causal events, including delayed effects of events which remains a problematic question in most existing theories about action and change.
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The Short Term Assessment of Risk and Treatability is a structured judgement tool used to inform risk estimation for multiple adverse outcomes. In research, risk estimates outperform the tool's strength and vulnerability scales for violence prediction. Little is known about what its’component parts contribute to the assignment of risk estimates and how those estimates fare in prediction of non-violent adverse outcomes compared with the structured components. START assessment and outcomes data from a secure mental health service (N=84) was collected. Binomial and multinomial regression analyses determined the contribution of selected elements of the START structured domain and recent adverse risk events to risk estimates and outcomes prediction for violence, self-harm/suicidality, victimisation, and self-neglect. START vulnerabilities and lifetime history of violence, predicted the violence risk estimate; self-harm and victimisation estimates were predicted only by corresponding recent adverse events. Recent adverse events uniquely predicted all corresponding outcomes, with the exception of self-neglect which was predicted by the strength scale. Only for victimisation did the risk estimate outperform prediction based on the START components and recent adverse events. In the absence of recent corresponding risk behaviour, restrictions imposed on the basis of START-informed risk estimates could be unwarranted and may be unethical.
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The study of Victorian crime and punishment is a rich area of research that has attracted the interest not only of literary scholars but also of social historians, legal historians, and criminologists. Related scholarship therefore often situates itself at the intersection of traditional disciplinary boundaries, facilitating interdisciplinary conversation. Crime and punishment was a pressing issue for the Victorians and provoked a wealth of responses from contemporaneous commentators in literature, culture, and science. As a new phase of industrialization brought immense wealth for some and abject poverty for others, Victorian urban centers in particular were afflicted by crime. Without an effective system of social welfare in place, social inequality and deprivation drove women, men, and children into petty crime and more serious offenses, resulting in severe punishment ranging from incarceration via penal transportation to hanging. Public executions, not abolished until 1868, attracted huge crowds of spectators, including authors such as Charles Dickens and William Thackeray, who wrote about these experiences. A forerunner of the popular press, street literature conveyed and illustrated these events for a broad audience. Execution broadsides of famous cases, printing the alleged last lamentations of convicts on the scaffold in verse, are estimated to have sold by the million. As the legal system was undergoing reform (comprising changes in legal evidence procedure, divorce law, women’s property rights, and punishment for sexual offenses, for example), sensational trials caused furor and stimulated commentary in literature and the media. Crime and punishment was discussed in a range of literary and popular genres, poetry, and reformist writing. The “Newgate School” of fiction was accused of glamorizing crime, and the popular penny dreadfuls were feared to corrupt public morals. Sensational fiction in the 1860s, which often drew on real-life criminal cases and newspaper reports, depicted the supposedly respectable middle-class family home as a center of transgression. Similarly, detective fiction typically focused on crime in the world of the middle classes. For the student new to the subject of crime and punishment, this area’s interdisciplinary nature can pose an initial challenge.
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Institutions are widely regarded as important, even ultimate drivers of economic growth and performance. A recent mainstream of institutional economics has concentrated on the effect of persisting, often imprecisely measured institutions and on cataclysmic events as agents of noteworthy institutional change. As a consequence, institutional change without large-scale shocks has received little attention. In this dissertation I apply a complementary, quantitative-descriptive approach that relies on measures of actually enforced institutions to study institutional persistence and change over a long time period that is undisturbed by the typically studied cataclysmic events. By placing institutional change into the center of attention one can recognize different speeds of institutional innovation and the continuous coexistence of institutional persistence and change. Specifically, I combine text mining procedures, network analysis techniques and statistical approaches to study persistence and change in England’s common law over the Industrial Revolution (1700-1865). Based on the doctrine of precedent - a peculiarity of common law systems - I construct and analyze the apparently first citation network that reflects lawmaking in England. Most strikingly, I find large-scale change in the making of English common law around the turn of the 19th century - a period free from the typically studied cataclysmic events. Within a few decades a legal innovation process with low depreciation rates (1 to 2 percent) and strong past-persistence transitioned to a present-focused innovation process with significantly higher depreciation rates (4 to 6 percent) and weak past-persistence. Comparison with U.S. Supreme Court data reveals a similar U.S. transition towards the end of the 19th century. The English and U.S. transitions appear to have unfolded in a very specific manner: a new body of law arose during the transitions and developed in a self-referential manner while the existing body of law lost influence, but remained prominent. Additional findings suggest that Parliament doubled its influence on the making of case law within the first decades after the Glorious Revolution and that England’s legal rules manifested a high degree of long-term persistence. The latter allows for the possibility that the often-noted persistence of institutional outcomes derives from the actual persistence of institutions.
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Abstract We present ideas about creating a next generation Intrusion Detection System (IDS) based on the latest immunological theories. The central challenge with computer security is determining the difference between normal and potentially harmful activity. For half a century, developers have protected their systems by coding rules that identify and block specific events. However, the nature of current and future threats in conjunction with ever larger IT systems urgently requires the development of automated and adaptive defensive tools. A promising solution is emerging in the form of Artificial Immune Systems (AIS): The Human Immune System (HIS) can detect and defend against harmful and previously unseen invaders, so can we not build a similar Intrusion Detection System (IDS) for our computers? Presumably, those systems would then have the same beneficial properties as HIS like error tolerance, adaptation and self-monitoring. Current AIS have been successful on test systems, but the algorithms rely on self-nonself discrimination, as stipulated in classical immunology. However, immunologist are increasingly finding fault with traditional self-nonself thinking and a new 'Danger Theory' (DT) is emerging. This new theory suggests that the immune system reacts to threats based on the correlation of various (danger) signals and it provides a method of 'grounding' the immune response, i.e. linking it directly to the attacker. Little is currently understood of the precise nature and correlation of these signals and the theory is a topic of hot debate. It is the aim of this research to investigate this correlation and to translate the DT into the realms of computer security, thereby creating AIS that are no longer limited by self-nonself discrimination. It should be noted that we do not intend to defend this controversial theory per se, although as a deliverable this project will add to the body of knowledge in this area. Rather we are interested in its merits for scaling up AIS applications by overcoming self-nonself discrimination problems.
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TORT, A. B. L. ; SCHEFFER-TEIXEIRA, R ; Souza, B.C. ; DRAGUHN, A. ; BRANKACK, J. . Theta-associated high-frequency oscillations (110-160 Hz) in the hippocampus and neocortex. Progress in Neurobiology , v. 100, p. 1-14, 2013.
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Rapid climatic changes are taking place in Arctic, subarctic and cold temperate regions, where predictions point to an increase in freeze-thaw events, changes in precipitation, evaporation and salinity patterns. Climate change may therefore result in large impacts in ecosystem functioning and dynamics, especially in the presence of contaminants due to intense anthropogenic activities. Even though multiple stress approaches have received increasing interest in the last decades, the number of such studies is limited. In particular, knowledge on the effect of freezethaw events and salinity fluctuations on ecotoxicology of soil invertebrates is lacking, especially important when considering supralittoral species. Therefore, the aim of this thesis was to investigate the effects of low temperature and salinity fluctuations, singly and in combination with contaminants, in the freeze-tolerant and euryhaline enchytraeid Enchytraeus albidus. The assessment of population level endpoints (survival and reproduction), along with physiological and biochemical parameters such as levels of cryoprotectants, ice/water content, oxidative stress biomarkers, cellular energy allocation, and tissue concentration of chemicals (when applied), provided new and valuable knowledge on the effects of selected physical and chemical stressors in E. albidus, and allowed the understanding of adjustments in the primary response mechanisms that enable worms to maintain homeostasis and survival in harsh environments such as polar and temperate-cold regions. The presence of moderate levels of salinity significantly increased freeze-tolerance (mainly evaluated as survival, cryoprotection and ice fraction) and reproduction of E. albidus. Moreover, it contributed to the readjustments of cryoprotectant levels, restoration of antioxidant levels and changed singnificantly the effect and uptake of chemicals (copper cadmium, carbendazim and 4-nonylphenol). Temperature fluctuations (simulated as daily freeze-thaw cycles, between -2ºC and -4ºC) caused substancial negative effect on survival of worms previsouly exposed to non-lethal concentrations of 4-nonylphenol, as compared with constant freezing (-4ºC) and control temperature (2ºC). The decrease in cryoprotectants, increase in energy consumption and the highest concentration of 4-nonylphenol in the tissues have highlighted the high energy requirements and level of toxicity experienced by worms exposed to the combined effect of contaminants and freezing-thawing events. The findings reported on this thesis demonstrate that natural (physical) and chemical stressors, singly or in combination, may alter the dynamics of E. albidus, affecting not only their survival and reproduction (and consequent presence/distribution) but also their physiological and biochemical adaptations. These alterations may lead to severe consequences for the functioning of the ecosystems along the Arctic, subarctic and cold temperate regions, where they play an important role for decomposition of dead organic matter. This thesis provides a scientific basis for improving the setting of safety factors for natural soil ecosystems, and to underline the integration of similar investigations in ecotoxicology, and eventually in risk assessment of contaminants.
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There are many ways in which research messages and findings can be extended to the expansive cotton community. As everyone learns differently it is crucial that information is delivered in a variety of ways to meet the various learning needs of the CottonInfo team’s broad audience. In addition different cotton production areas often require targeted information to address specific challenges. Successful implementation of innovative research outcomes typically relies on a history of cultivated communication between the researcher and the end-user, the grower. The CottonInfo team, supported by a joint venture between Cotton Seed Distributors, Cotton Research Development Corporation, Cotton Australia and other collaborative partners, represents a unique model of extension in Australian agriculture. Industry research is extended via regionally based Regional Development Officers backed by support from Technical Specialists. The 2015 Cotton Irrigation Technology Tour is one example of a successful CottonInfo capacity building activity. This tour took seven CRDC funded irrigation-specific researchers to Emerald, Moree and Nevertire to showcase their research and technologies. These events provided irrigators and consultants with the opportunity to hear first-hand from researchers about their technologies and how they could be applied onfarm. This tour was an example of how the CottonInfo team can connect growers and researchers, not only to provide an avenue for growers to learn about the latest irrigation research, but for researchers to receive feedback about their current and future irrigation research.
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The aim of this study was to compute a swimming performance confirmatory model based on biomechanical parameters. The sample included 100 young swimmers (overall: 12.3 ± 0.74 years; 49 boys: 12.5 ± 0.76 years; 51 girls: 12.2 ± 0.71 years; both genders in Tanner stages 1-2 by self-report) participating on a regular basis in regional and national-level events. The 100 m freestyle event was chosen as the performance indicator. Anthropometric (arm span), strength (throwing velocity), power output (power to overcome drag), kinematic (swimming velocity) and efficiency (propelling efficiency) parameters were measured and included in the model. The path-flow analysis procedure was used to design and compute the model. The anthropometric parameter (arm span) was excluded in the final model, increasing its goodness-of-fit. The final model included the throw velocity, power output, swimming velocity and propelling efficiency. All links were significant between the parameters included, but the throw velocity-power output. The final model was explained by 69% presenting a reasonable adjustment (model's goodness-of-fit; x(2)/df = 3.89). This model shows that strength and power output parameters do play a mediator and meaningful role in the young swimmers' performance.
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Understanding the natural evolution of a river–delta–sea system is important to develop a strong scientific basis for efficient integrated management plans. The distribution of sediment fluxes is linked with the natural connection between sediment source areas situated in uplifting mountain chains and deposition in plains, deltas and, ultimately, in the capturing oceans and seas. The Danube River–western Black Sea is one of the most active European systems in terms of sediment re-distribution that poses significant societal challenges. We aim to derive the tectonic and sedimentological background of human-induced changes in this system and discuss their interplay. This is obtained by analysing the tectonic and associated vertical movements, the evolution of relevant basins and the key events affecting sediment routing and deposition. The analysis of the main source and sink areas is focused in particular on the Miocene evolution of the Carpatho-Balkanides, Dinarides and their sedimentary basins including the western Black Sea. The vertical movements of mountains chains created the main moments of basin connectivity observed in the Danube system. Their timing and effects are observed in sediments deposited in the vicinity of gateways, such as the transition between the Pannonian/Transylvanian and Dacian basins and between the Dacian Basin and western Black Sea. The results demonstrate the importance of understanding threshold conditions driving rapid basins connectivity changes superposed over the longer time scale of tectonic-induced vertical movements associated with background erosion and sedimentation. The spatial and temporal scale of such processes is contrastingly different and challenging. The long-term patterns interact with recent or anthropogenic induced modifications in the natural system and may result in rapid changes at threshold conditions that can be quantified and predicted. Their understanding is critical because of frequent occurrence during orogenic evolution, as commonly observed in the Mediterranean area and discussed elsewhere.
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Cranial cruciate ligament (CCL) deficiency is the leading cause of lameness affecting the stifle joints of large breed dogs, especially Labrador Retrievers. Although CCL disease has been studied extensively, its exact pathogenesis and the primary cause leading to CCL rupture remain controversial. However, weakening secondary to repetitive microtrauma is currently believed to cause the majority of CCL instabilities diagnosed in dogs. Techniques of gait analysis have become the most productive tools to investigate normal and pathological gait in human and veterinary subjects. The inverse dynamics analysis approach models the limb as a series of connected linkages and integrates morphometric data to yield information about the net joint moment, patterns of muscle power and joint reaction forces. The results of these studies have greatly advanced our understanding of the pathogenesis of joint diseases in humans. A muscular imbalance between the hamstring and quadriceps muscles has been suggested as a cause for anterior cruciate ligament rupture in female athletes. Based on these findings, neuromuscular training programs leading to a relative risk reduction of up to 80% has been designed. In spite of the cost and morbidity associated with CCL disease and its management, very few studies have focused on the inverse dynamics gait analysis of this condition in dogs. The general goals of this research were (1) to further define gait mechanism in Labrador Retrievers with and without CCL-deficiency, (2) to identify individual dogs that are susceptible to CCL disease, and (3) to characterize their gait. The mass, location of the center of mass (COM), and mass moment of inertia of hind limb segments were calculated using a noninvasive method based on computerized tomography of normal and CCL-deficient Labrador Retrievers. Regression models were developed to determine predictive equations to estimate body segment parameters on the basis of simple morphometric measurements, providing a basis for nonterminal studies of inverse dynamics of the hind limbs in Labrador Retrievers. Kinematic, ground reaction forces (GRF) and morphometric data were combined in an inverse dynamics approach to compute hock, stifle and hip net moments, powers and joint reaction forces (JRF) while trotting in normal, CCL-deficient or sound contralateral limbs. Reductions in joint moment, power, and loads observed in CCL-deficient limbs were interpreted as modifications adopted to reduce or avoid painful mobilization of the injured stifle joint. Lameness resulting from CCL disease affected predominantly reaction forces during the braking phase and the extension during push-off. Kinetics also identified a greater joint moment and power of the contralateral limbs compared with normal, particularly of the stifle extensor muscles group, which may correlate with the lameness observed, but also with the predisposition of contralateral limbs to CCL deficiency in dogs. For the first time, surface EMG patterns of major hind limb muscles during trotting gait of healthy Labrador Retrievers were characterized and compared with kinetic and kinematic data of the stifle joint. The use of surface EMG highlighted the co-contraction patterns of the muscles around the stifle joint, which were documented during transition periods between flexion and extension of the joint, but also during the flexion observed in the weight bearing phase. Identification of possible differences in EMG activation characteristics between healthy patients and dogs with or predisposed to orthopedic and neurological disease may help understanding the neuromuscular abnormality and gait mechanics of such disorders in the future. Conformation parameters, obtained from femoral and tibial radiographs, hind limb CT images, and dual-energy X-ray absorptiometry, of hind limbs predisposed to CCL deficiency were compared with the conformation parameters from hind limbs at low risk. A combination of tibial plateau angle and femoral anteversion angle measured on radiographs was determined optimal for discriminating predisposed and non-predisposed limbs for CCL disease in Labrador Retrievers using a receiver operating characteristic curve analysis method. In the future, the tibial plateau angle (TPA) and femoral anteversion angle (FAA) may be used to screen dogs suspected of being susceptible to CCL disease. Last, kinematics and kinetics across the hock, stifle and hip joints in Labrador Retrievers presumed to be at low risk based on their radiographic TPA and FAA were compared to gait data from dogs presumed to be predisposed to CCL disease for overground and treadmill trotting gait. For overground trials, extensor moment at the hock and energy generated around the hock and stifle joints were increased in predisposed limbs compared to non predisposed limbs. For treadmill trials, dogs qualified as predisposed to CCL disease held their stifle at a greater degree of flexion, extended their hock less, and generated more energy around the stifle joints while trotting on a treadmill compared with dogs at low risk. This characterization of the gait mechanics of Labrador Retrievers at low risk or predisposed to CCL disease may help developing and monitoring preventive exercise programs to decrease gastrocnemius dominance and strengthened the hamstring muscle group.
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The In Situ Analysis System (ISAS) was developed to produce gridded fields of temperature and salinity that preserve as much as possible the time and space sampling capabilities of the Argo network of profiling floats. Since the first global re-analysis performed in 2009, the system has evolved and a careful delayed mode processing of the 2002-2012 dataset has been carried out using version 6 of ISAS and updating the statistics to produce the ISAS13 analysis. This last version is now implemented as the operational analysis tool at the Coriolis data centre. The robustness of the results with respect to the system evolution is explored through global quantities of climatological interest: the Ocean Heat Content and the Steric Height. Estimates of errors consistent with the methodology are computed. This study shows that building reliable statistics on the fields is fundamental to improve the monthly estimates and to determine the absolute error bars. The new mean fields and variances deduced from the ISAS13 re-analysis and dataset show significant changes relative to the previous ISAS estimates, in particular in the southern ocean, justifying the iterative procedure. During the decade covered by Argo, the intermediate waters appear warmer and saltier in the North Atlantic and fresher in the Southern Ocean than in WOA05 long term mean. At inter-annual scale, the impact of ENSO on the Ocean Heat Content and Steric Height is observed during the 2006-2007 and 2009-2010 events captured by the network.