192 research outputs found
Nonlinear Site Response During the 7 September 1999 Athens, Greece, Earthquake (M\u3csub\u3eW\u3c/sub\u3e 5.6)
The largest available strong-motion recording (PGA=0.35g), least affected by topography, structural response and/or soil-structure interaction, is investigated for possible nonlinear site response during the M, 5.9 Athens earthquake of 7 September 1999. Smoothed horizontal-to-vertical spectral ratios (HVSR) are calculated in subsequent overlapping 3.5-s windows, thus covering a wide range of excitation levels. Mean HVSR curves are computed for a so-called âweak-â and âstrong-â motion range (mean horizontal ground acceleration in window, MGA\u3c=10.2 cm/s/s and \u3e=20.5 cm/s/s). The two curves have similar shape, with the âstrongâ curve visibly shifted toward lower frequencies relative to the âweakâ one; the dominant site resonance occurs at 4.0 Hz (0.25 s) and 4.7 Hz (0.21 s), respectively. Linear correlation analysis shows that the resonance frequency, f0, and MGA are significantly correlated (t=-0.661). We attribute this behaviour to the degradation of the sediment shear modulus (nonlinearity). Our results, combined with indications that sediment sites in the near-fault area were exposed to ground shaking well above PGA=0.35 g during the earthquake of 7 September 1999, imply that these sites exhibited considerable nonlinear response
Climate change adaptation for seaports by Climate Change Risk Indicators (CCRI)
The study is to provide a Climate Change Risk Indicators (CCRI) framework for climate adaptation for seaports, to link research to policy-making process on such a demanding topic. This paper first provides a literature review with international bodies and technical bodies on climate change adaptation for seaports. Second, a Fuzzy Evidential Reasoning (FER) model is employed to evaluate the climate risks in seaports. Third, six seaports in United Kingdom (UK) are selected for examples to demonstrate the use of CCRI. Finally, a comparative analysis of Yangtze River Delta and the United Kingdom (UK) in climates and seaport industries is done to visualize the possibilities in implementing the frameworks
Review on Seaport and Airport Adaptation to Climate Change: A Case on Sea Level Rise and Flooding
Seaports and airports are the critical nodes of international supply chains and thus stand on the edge of social and economic disasters. They are often affected by extreme and rough weather. Comparing all climate threats, sea level rise (SLR) and storming and flooding currently present, according to the relevant literature, the most severe impact in ports and airports. This paper aims to provide a comprehensive review of seaport and airport adaptation to climate change with a focus on SLR and flooding. We have summarized all related research papers and divided them into different types and described the trend of studies. After that, the study involves a comparison to analyze the synergy between previous studies in seaports and airports and provides insights for further studies to emphasize the needs and opportunities for the collaborative work that can complement the adaptation planning of and ensure the resilience of seaports and airports
Prioritizing Vehicle Cleanliness (PVC) using Key Green Performance Indicators (KGPI)
Climate catastrophes (e.g. hurricane, flooding and heat waves) are generating increasing impact on port operations and hence configuration of shipping networks. This paper formulates the routing problem to optimise the resilience of shipping networks, by taking into account the disruptions due to climate risks to port operations. It first describes a literature review with the emphasis on environmental sustainability, port disruptions due to climate extremes and routing optimisation in shipping operations. Second, a centrality assessment of port cities by a novel multi-centrality-based indicator is implemented. Third, a climate resilience model is developed by incorporating the port disruption days by climate risks into shipping route optimisation. Its main contribution is constructing a novel methodology to connect climate risk indices, centrality assessment, and shipping routing to observe the changes of global shipping network by climate change impacts
Pattern recognition receptor-mediated cytokine response in infants across 4 continentsâ
Background
Susceptibility to infection as well as response to vaccination varies among populations. To date, the underlying mechanisms responsible for these clinical observations have not been fully delineated. Because innate immunity instructs adaptive immunity, we hypothesized that differences between populations in innate immune responses may represent a mechanistic link to variation in susceptibility to infection or response to vaccination.
Objective
Determine whether differences in innate immune responses exist among infants from different continents of the world.
Methods
We determined the innate cytokine response following pattern recognition receptor (PRR) stimulation of whole blood from 2-year-old infants across 4 continents (Africa, North America, South America, and Europe).
Results
We found that despite the many possible genetic and environmental exposure differences in infants across 4 continents, innate cytokine responses were similar for infants from North America, South America, and Europe. However, cells from South African infants secreted significantly lower levels of cytokines than did cells from infants from the 3 other sites, and did so following stimulation of extracellular and endosomal but not cytosolic PRRs.
Conclusions
Substantial differences in innate cytokine responses to PRR stimulation exist among different populations of infants that could not have been predicted. Delineating the underlying mechanism(s) for these differences will not only aid in improving vaccine-mediated protection but possibly also provide clues for the susceptibility to infection in different regions of the world
So happy for your loss: Consumer schadenfreude increases choice satisfaction
Consumers often feel schadenfreude, an emotion reflecting an experience of pleasure over misfortunes of another. Schadenfreude has found wide use in advertising, but its actual consequences for consumers have not been thoroughly documented. The present research investigates the effect of schadenfreude on consumers' satisfaction with choices they have made. Building on the feelingsâasâinformation theory, the authors posit that consumers take their positive feelings of schadenfreude over another's unrelated bad purchase as positive information about their own choices, and through such misattribution become more satisfied with their own choices. Three experiments show that feeling schadenfreude over another consumer's bad purchase makes consumers more satisfied with their own choices (Study 1), regardless of whether the other's bad purchase is in the same or in a different product category as one's own choice (Study 2), but only so long as consumers are not aware that they are engaging in misattribution (Study 3). The present research contributes to the literature on schadenfreude and feelingsâasâinformation theory. Its findings may be used by marketers aiming to exert an unconscious influence on consumer satisfaction
Empirical evaluation of microtremor H/V spectral ratio
The objective of this work is to perform a purely empirical assessment of the actual capabilities of the horizontal-to-vertical (H/V) spectral ratio technique to provide reliable and relevant information concerning site conditions and/or site amplification. This objective has been tackled through the homogeneous (re)processing of a large volume of earthquakes and ambient noise data recorded by different research teams in more than 200 sites located mainly in Europe, but also in the Caribbean and in Tehran. The original recordings were first gathered in a specific database with information on both the sites and recorded events. Then, for all sites close to an instrumented reference, average site-to-reference spectral ratios (âspectral ratio methodâ (SSR)) were derived in a homogeneous way (window selection, smoothing, signal-to-noise ratio threshold, averaging), as well as H/V ratios (âHVSREâRFâ) on earthquake recordings. H/V ratios were also obtained from noise recordings at each site (either specific measurements, or extracted from pre- or post-event noise windows). The spectral curves resulting from these three techniques were estimated reliable for a subset of 104 sites, and were thus compared in terms of fundamental frequency, amplitude and amplification bandwidth, exhibiting agreements and disagreements, for which interpretations are looked for in relation with characteristics of site conditions. The first important result consists in the very good agreement between fundamental frequencies obtained with either technique, observed for 81% of the analyzed sites. A significant part of the disagreements correspond to thick, low frequency, continental sites where natural noise level is often very low and H/V noise ratios do not exhibit any clear peak. The second important result is the absence of correlation between H/V peak amplitude and the actual site amplification measured on site-to-reference spectral ratios. There are, however, two statistically significant results about the amplitude of the H/V curve: the peak amplitude may be considered as a lower bound estimate of the actual amplification indicated by SSR (it is smaller for 79% of the 104 investigated sites), and, from another point of view, the difference in amplitude exhibits a questioning correlation with the geometrical characteristics of the sediment/basement interface: large SSR/HV differences might thus help to detect the existence of significant 2D or 3D effects.Published75-1084.1. Metodologie sismologiche per l'ingegneria sismicaJCR Journalreserve
Impact analysis of climate change on rail systems for adaptation planning: A UK case
Climate change poses critical challenges for rail infrastructure and operations. However, the systematic analysis of climate risks and the associated costs of tackling them, particularly from a quantitative perspective, is still at an embryonic phase due to the kaleidoscopic nature of climate change impacts and lack of precise climatic data. To cope with such challenges, an advanced Fuzzy Bayesian Reasoning (FBR) model is applied in this paper to understand climate threats of the railway system. This model ranks climate risks under high uncertainty in data and comprehensively evaluates these risks by taking account of infrastructure resilience and specific aspects of severity of consequence. Through conducting a nationwide survey on the British railway system, it dissects the status quo of primary climate risks. The survey implies that the top potential climate threats are heavy precipitation and floods. The primary risks caused by the climate threats are bridges collapsing and bridge foundation damage due to flooding and landslips. The findings can aid transport planners to prioritise climate risks and develop rational adaptation measures and strategies
Genetic information transfer promotes cooperation in bacteria
Many bacterial species are social, producing costly secreted âpublic goodâ molecules that enhance the growth of neighboring cells. The genes coding for these cooperative traits are often propagated via mobile genetic elements and can be virulence factors from a biomedical perspective. Here, we present an experimental framework that links genetic information exchange and the selection of cooperative traits. Using simulations and experiments based on a synthetic bacterial system to control public good secretion and plasmid conjugation, we demonstrate that horizontal gene transfer can favor cooperation. In a well-mixed environment, horizontal transfer brings a direct infectious advantage to any gene, regardless of its cooperation properties. However, in a structured population transfer selects specifically for cooperation by increasing the assortment among cooperative alleles. Conjugation allows cooperative alleles to overcome rarity thresholds and invade bacterial populations structured purely by stochastic dilution effects. Our results provide an explanation for the prevalence of cooperative genes on mobile elements, and suggest a previously unidentified benefit of horizontal gene transfer for bacteria
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