104 resultados para volcanic events
Resumo:
Sport Mega-event hosting faces opposition that is manifested with different intensity during the different phases of the event, from its inception as an idea to its delivery and legacy. Some Social Movements Organisations (SMOs) have acted as indefatigable monitors of the Sustainable Development (SD) dimension of sporting events in general and, in some of the most recent sport mega-events, in particular the Olympics, they have served as important advisors and facilitators. Nevertheless, in many cases we see enthusiastic supporters turning to vehemently challenging whatever positives have been associated with hosting the event. In addition, there is opposition to sport Mega-events in their entirety. That type of opposition tends to employ a holistic prism that manages to identify multiple interconnected negative aspects of hosting a sport mega-event and incorporate them into an anti-systemic discourse. It is important to bear in mind that irrespective of many proclamations to the opposite as far as megas are concerned (projects and/or events), a number of studies have demonstrated that citizen participation and democratic accountability in decision-making have been notoriously absent. After all, the idea of citizen participation in the planning of sport mega-event is essentially the public response to a plan conceived by others. There were, of course, some notable cases of democratic consultation at the early stages of bidding to host a sport mega-event but these more democratic approaches resulted in the failure of the bid (for e.g. Toronto 1996). The knowledge of this by the groups that initiated the hosting idea and the bidding process has led to discouraging in depth public consultation that may fit perfectly to the democratic process but not to the tight schedules of associated projects completion. That produces ‘autocracy against which opposition may arise’ (Hiller, 2000, p. 198). It is this democratic deficit that has led to important instances of social contestation and protest mobilizations by citizen groups as well as the more regular corps of social activists. From a perspective borrowed from the sociology of protest and social movements, sport mega-events hosting can operate as an issue that stimulates protest activities by an existing protest milieu and new actors as well as an important mobilizing resource. In fact, some scholars have also argued that the Olympic Games were an important frame for the transnational activism that was marked by anti-globalization protest in Seattle in 1999 (Cottrell & Nelson, 201; Lenskyj, 2008). In addition, it’s important not to lose sight of other acts dissent that take place in relatively close proximity, about a year before the event when most infrastructural and societal changes brought by hosting the event and impact start to become apparent by the host communities, like the rioting of August 2011 in the London Olympic Boroughs and the 2012 riots of June 2013 in Sao Paulo and other Brazilian cities. This paper starts by outlining the SD claims made in the bidding to host the summer Olympic Games by five prospective hosts (Sydney; Athens; Beijing; London and Rio) proceeds towards examining the opposition and challenges that was manifested in relation to these claims. In Particular it provides an assessment of protest-events over the aforementioned different phases of sport mega-events hosting. A different picture emerges for each of the host nation that is partly explained by local, national and global configuration of protest politics. Whereas the post-event legacy of the first two hosts of the Games can be assessed and that way see the validity of claims made by challengers in the other phases, in the other three cases, the implementation of Olympic Games Impact (OGI) studies offers the tool for discussing the post-event phase for Beijing and London and engage in a speculative exercise for the case of Rio. Judging by available findings, the paper concludes that the SD aspiration made in the bid documents are unlikely to be met and social contestation based on the same issues is likely to increase due to the current global economic crisis and BRICS, like China and Brazil, having entered the process of becoming global economic hegemons.
Resumo:
This article examines the difficulties of finding local solutions to the problem of contentious events in contemporary Northern Ireland. In so doing, it offers a sociological perspective on fundamental divisions in Northern Ireland: between classes and between communities. It shows how its chosen case study—parades and associated protests in north Belfast—exemplifies the most fundamental problem that endures in post-Agreement Northern Ireland, namely that political authority is not derived from a common civic culture (as is the norm in Western liberal democracy) but rather that legitimacy is still founded on the basis of the culture of either one or the other community. Haugaard’s reflections on authority and legitimacy are used to explore Northern Ireland’s atypical experience of political conflict vis-`a-vis the Western liberal democratic model. The Bourdieusian concepts of field illusio and doxa help to explain why it is that parading remains such an important political and symbolic touchstone in this society.
Resumo:
In this article, we discuss our experiences of using photography and video while observing contentious parades and protests in Belfast. We show how our use of these methods drew us into a series of unplanned for non-verbal interactions with other event participants who were also freely and abundantly using photographic and filming equipment to capture their own images. This interactive use of photography and video affected us emotionally and influenced what we noticed and what we omitted in our observations. In particular, it forced us to reflect upon and question our role as researchers in the events we observed and in the changing balance of power between researchers and researched.
Resumo:
An extensive micro-tephrostratigraphic survey of three small lakes in the Scottish Inner Hebrides was conducted encompassing the Last Glacial–Interglacial Transition (LGIT). The lakes are highly contrasting in terms of lake area to catchment ratio, the presence or absence of stream inlets draining the catchment, and in the complexity of the catchment drainage network. A suite of distal Icelandic volcanic ashes was consistently detected in all three lakes, with three, namely Penifiler Tephra, Vedde Ash and Ashik Tephra, being common to all the lakes. These ashes were chosen to examine the taphonomic intercomparability of ash location and concentration among the lakes. Findings reveal that the part played by catchment inlets in determining ash concentration and within-basin location applies to microtephra layers as much as it does in studies of macrotephra layer thickness. The position of ash concentration maxima is also shown to vary significantly for different LGIT periods and may be a consequence of lake-level changes, especially during the early Holocene. High-resolution stratigraphic analysis through the Vedde Ash visible macrotephra at Loch Ashik reveals a high degree of complexity in taphonomic behaviour between the different geochemical components, with possible implications for the correct interpretation of the isochron position. The detection of multiple intact ash isochrons and the taphonomic processes responsible for their deposition should prove useful in future tephrostratigraphic surveys, as well as having applications within other palaeolimnological disciplines.
Resumo:
Traditionally, audio-motor timing processes have been understood as motor output from an internal clock, the speed of which is set by heard sound pulses. In contrast, this paper proposes a more ecologically-grounded approach, arguing that audio-motor processes are better characterized as performed actions on the perceived structure of auditory events. This position is explored in the context of auditory sensorimotor synchronization and continuation timing. Empirical research shows that the structure of sounds as auditory events can lead to marked differences in movement timing performance. The nature of these effects is discussed in the context of perceived action-relevance of auditory event structure. It is proposed that different forms of sound invite or support different patterns of sensorimotor timing. Hence, the temporal information in looped auditory signals is more than just the interval durations between onsets: all metronomes are not created equal. The potential implications for auditory guides in motor performance enhancement are also described.
Resumo:
The ~16-ka-long record of explosive eruptions from Shiveluch volcano (Kamchatka, NW Pacific) is refined using geochemical fingerprinting of tephra and radiocarbon ages. Volcanic glass from 77 prominent Holocene tephras and four Late Glacial tephra packages was analyzed by electron microprobe. Eruption ages were estimated using 113 radiocarbon dates for proximal tephra sequence. These radiocarbon dates were combined with 76 dates for regional Kamchatka marker tephra layers into a single Bayesian framework taking into account the stratigraphic ordering within and between the sites. As a result, we report ~1,700 high-quality glass analyses from Late Glacial–Holocene Shiveluch eruptions of known ages. These define the magmatic evolution of the volcano and provide a reference for correlations with distal fall deposits. Shiveluch tephras represent two major types of magmas, which have been feeding the volcano during the Late Glacial–Holocene time: Baidarny basaltic andesites and Young Shiveluch andesites. Baidarny tephras erupted mostly during the Late Glacial time (~16–12.8 ka BP) but persisted into the Holocene as subordinate admixture to the prevailing Young Shiveluch andesitic tephras (~12.7 ka BP–present). Baidarny basaltic andesite tephras have trachyandesite and trachydacite (SiO2 < 71.5 wt%) glasses. The Young Shiveluch andesite tephras have rhyolitic glasses (SiO2 > 71.5 wt%). Strongly calc-alkaline medium-K characteristics of Shiveluch volcanic glasses along with moderate Cl, CaO and low P2O5 contents permit reliable discrimination of Shiveluch tephras from the majority of other large Holocene tephras of Kamchatka. The Young Shiveluch glasses exhibit wave-like variations in SiO2 contents through time that may reflect alternating periods of high and low frequency/volume of magma supply to deep magma reservoirs beneath the volcano. The compositional variability of Shiveluch glass allows geochemical fingerprinting of individual Shiveluch tephra layers which along with age estimates facilitates their use as a dating tool in paleovolcanological, paleoseismological, paleoenvironmental and archeological studies. Electronic tables accompanying this work offer a tool for statistical correlation of unknown tephras with proximal Shiveluch units taking into account sectors of actual tephra dispersal, eruption size and expected age. Several examples illustrate the effectiveness of the new database. The data are used to assign a few previously enigmatic wide-spread tephras to particular Shiveluch eruptions. Our finding of Shiveluch tephras in sediment cores in the Bering Sea at a distance of ~600 km from the source permits re-assessment of the maximum dispersal distances for Shiveluch tephras and provides links between terrestrial and marine paleoenvironmental records.
Resumo:
Background and Purpose-The aim was to investigate prospectively the all-cause mortality risk up to and after coronary heart disease (CHD) and stroke events in European middle-aged men.
Methods-The study population comprised 10 424 men 50 to 59 years of age recruited between 1991 and 1994 in France (N=7855) and Northern Ireland (N=2747) within the Prospective Epidemiological Study of Myocardial Infarction. Incident CHD and stroke events and deaths from all causes were prospectively registered during the 10-year follow-up. In Cox's proportional hazards regression analysis, CHD and stroke events during follow-up were used as time-dependent covariates.
Results-A total of 769 CHD and 132 stroke events were adjudicated, and 569 deaths up to and 66 after CHD or stroke occurred during follow-up. After adjustment for study country and cardiovascular risk factors, the hazard ratios of all-cause mortality were 1.58 (95% confidence interval 1.18-2.12) after CHD and 3.13 (95% confidence interval 1.98-4.92) after stroke.
Conclusions-These findings support continuous efforts to promote both primary and secondary prevention of cardiovascular disease.
Resumo:
Kamchatka is one of the world’s most active volcanic regions and has hosted many explosive eruptions during the Holocene. These eruptions had the potential to disperse tephra over wide areas, forming time-synchronous markers wherever those tephras are found. Recent research in Kamchatka has begun to focus on the geochemical analysis of individual glass shards in order to characterise tephra layers. We have applied this approach to the study of visible tephras from three lakes – one in central and two in northern Kamchatka – with the aim of identifying key tephras and potential issues in the application of distal (>100 km from an active volcano) tephra in volcanically complex regions. In total, 23 tephras from 22 tephra beds have been geochemically analysed, representing products from at least four volcanic systems in Kamchatka. We demonstrate that distal lake sediments in the region can yield reliable tephrostratigraphies, capturing tephra from eruptions that have the greatest potential to disperse volcanic ash beyond the region. We draw attention to issues relating to correlating and distinguishing key marker horizons from the highly active Shiveluch Volcano, namely the need to ensure inter-lab comparability of geochemical data and good chronological control of the proximal and distal tephras. Importantly, we have also extended the known distribution of two key tephra isochrons from the Ksudach volcano. Our work contributes valuable glass geochemical on data several key marker beds that will facilitate future tephra and palaeoenvironmental research within and beyond Kamchatka.
Resumo:
Climate change during the last deglaciation was strongly influenced by the „bipolar seesaw‟, producing antiphase climate responses between the North and South Atlantic. However, mounting evidence demands refinements of this model, with the occurrence of abrupt events in southern low to mid latitudes occurring in-phase with North Atlantic climate. Improved constraints on the north-south phasing and spatial extent of these events are therefore critical to
understanding the mechanisms that propagate abrupt events within the climate system. We present a 19,400 year multi-proxy record of climate change obtained from a rock hyrax midden in southernmost Africa. Arid anomalies in phase with the Younger Dryas and 8.2 ka events are apparent, indicating a clear shift in the influence of the bipolar seesaw, which diminished as the Earth warmed, and was succeeded after ~14.6 ka by the emergence of a dominant interhemispheric atmospheric teleconnection.
Resumo:
OBJECTIVE: To investigate the impact of smoking and smoking cessation on cardiovascular mortality, acute coronary events, and stroke events in people aged 60 and older, and to calculate and report risk advancement periods for cardiovascular mortality in addition to traditional epidemiological relative risk measures.
DESIGN: Individual participant meta-analysis using data from 25 cohorts participating in the CHANCES consortium. Data were harmonised, analysed separately employing Cox proportional hazard regression models, and combined by meta-analysis.
RESULTS: Overall, 503,905 participants aged 60 and older were included in this study, of whom 37,952 died from cardiovascular disease. Random effects meta-analysis of the association of smoking status with cardiovascular mortality yielded a summary hazard ratio of 2.07 (95% CI 1.82 to 2.36) for current smokers and 1.37 (1.25 to 1.49) for former smokers compared with never smokers. Corresponding summary estimates for risk advancement periods were 5.50 years (4.25 to 6.75) for current smokers and 2.16 years (1.38 to 2.39) for former smokers. The excess risk in smokers increased with cigarette consumption in a dose-response manner, and decreased continuously with time since smoking cessation in former smokers. Relative risk estimates for acute coronary events and for stroke events were somewhat lower than for cardiovascular mortality, but patterns were similar.
CONCLUSIONS: Our study corroborates and expands evidence from previous studies in showing that smoking is a strong independent risk factor of cardiovascular events and mortality even at older age, advancing cardiovascular mortality by more than five years, and demonstrating that smoking cessation in these age groups is still beneficial in reducing the excess risk.
Resumo:
The properties of Ellerman bombs (EBs), small-scale brightenings in the Hα line wings, have proved difficult to establish because their size is close to the spatial resolution of even the most advanced telescopes. Here, we aim to infer the size and lifetime of EBs using high-resolution data of an emerging active region collected using the Interferometric BIdimensional Spectrometer (IBIS) and Rapid Oscillations of the Solar Atmosphere (ROSA) instruments as well as the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). We develop an algorithm to track EBs through their evolution, finding that EBs can often be much smaller (around 0.3″) and shorter-lived (less than one minute) than previous estimates. A correlation between G-band magnetic bright points and EBs is also found. Combining SDO/HMI and G-band data gives a good proxy of the polarity for the vertical magnetic field. It is found that EBs often occur both over regions of opposite polarity flux and strong unipolar fields, possibly hinting at magnetic reconnection as a driver of these events.The energetics of EB events is found to follow a power-law distribution in the range of a nanoflare (1022-25 ergs).