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Climate scenarios produce climate change-related information and data at a geographical scale generally not useful for coastal planners to study impacts locally. To provide a suitable characterization of climate-related hazards in the North Adriatic Sea coast, a model chain, with progressively higher resolution was developed and implemented. It includes Global and Regional Circulation Models representing atmospheric and oceanic dynamics for the global and sub-continental domains, and hydrodynamic/wave models useful to analyze physical impacts of sea-level rise and coastal erosion at a sub-national/local scale. The model chain, integrating multiple types of numerical models running at different spatial scales, provides information about spatial and temporal patterns of relevant hazard metrics (e.g., sea temperature, atmospheric pressure, wave height), usable to represent climate-induced events causing potential environmental or socio-economic damages. Furthermore, it allows the discussion of some methodological problems concerning the application of climate scenarios and their dynamical downscaling to the assessment of the impacts in coastal zones. Based on a balanced across all energy sources emission scenario, the multi-model chain applied in the North Adriatic Sea allowed to assess the change in frequency of exceedance of wave height and bottom stress critical thresholds for sediment motion in the future scenario (2070&ndash, 2100) compared to the reference period 1960 to 1990. As discussed in the paper, such projections can be used to develop coastal erosion hazard scenarios, which can then be applied to risk assessment studies, providing valuable information to mainstream climate change adaptation in coastal zone management.

Esta dissertação pretendeu interpretar as representações fotográficas da área que hoje é compreendida como Chapada Diamantina, localizada no estado da Bahia. Para tanto, está sugerida a necessidade de considerar os limites objetivos da paisagem como categoria de análise do processo social do qual resulta e, consequentemente, de sua representação em fotografias. Na interpretação aqui empreendida, a paisagem e a fotografia que fazem aparecer tal processo, ao mesmo tempo escondem aquilo que lhe é substancial enquanto forma social. Característica própria da sociabilidade mediada pela mercadoria. Por isso, durante o processo de estudo, por um lado buscou-se montar um panorama interpretativo lógico e histórico da área estudada e dos nexos que estabelece enquanto particularidade com a totalidade da reprodução social capitalista em escala nacional e global. Em paralelo correlato, buscou-se estabelecer um quadro das relações que possibilitaram a produção de cada um dos grupos de imagens selecionados para a realização dessa pesquisa. A análise crítica desses processos é a intenção dessa dissertação. This dissertation intended to interpret the photographic representations of the area that today is understood as Chapada Diamantina, located in the state of Bahia. Therefore, it is suggested the need to consider the objective limits of the landscape as a category of analysis of the social process from which it results and, consequently, of its representation in photographs. In the interpretation made here, the landscape and the photograph that make this process appear, at the same time hide what is substantial as a social form. Characteristic of sociability mediated by the commodity. For this reason, during the study process, on the one hand we sought to create a logical and historical interpretive panorama of the area studied and the nexus that establishes as a particularity with the totality of capitalist social reproduction on a national and global scale. In parallel correlate, it was tried to establish a framework of the relations that enabled the production of each of the groups of images selected for the accomplishment of this research. The critical analysis of these processes is the intention of this dissertation.

Surfactant layers with viscoelastic properties floating on the water surface damp short gravity-capillary waves. Inspired by the known virtue of fish oil to still angry seas, a laboratory study has been made on wind wave generation and on the interaction between wind-waves, paddle-waves and airflow in a tank containing a thin fish oil film uniformly spread on the water surface. According to the Marangoni resonance-type damping mechanism, for oily surfaces the energy dissipation process is quite selective in wavenumbers, but its effects are not, since it spreads (although to a lesser extent) towards longer and shorter waves via nonlinear interactions and modification of the airflow profile. With a thin layer of oil on the surface, it is rather peculiar that in the wind-only condition (no paddle waves) the wave field does not grow from the rest condition. This equilibrium was altered by paddle (longer) waves, the generation and evolution of short waves (in clean water and with oil) being modified by their interaction with the orbital velocity of the longer waves and their effect on the airflow. Paddle waves did grow under the action of wind, how much being similar in clean and oily water conditions, a fact we ascribe to the similar distortion of the wind profile in the two cases. We have also found that wind-supported stress on the oily water surface was able to generate a surface current, whose magnitude turns out to be comparable to the one in clean water. Our results expand previous investigations on the same topic. We stress the benefit of experiments with surfactants to explore in detail the physics at, and the exchanges across, the wavy and no-wavy air-water interface.

This study aims at characterizing the distinctive features of a spatio-temporal random, moving, nonlinear wave 19 surface. We analyze wind-generated 3-D wave fields observed during the passage of an atmospheric front, which 20 led to a wide directional spreading of wave energy. Data were acquired from the Ocean Research Station 21 Socheongcho-ORS (Yellow Sea) with a stereo wave imaging system. They include 2-D + time measurements of the 22 sea surface elevation with high spatial and temporal resolution over a swath larger than any previous similar 23 deployment. We examine the shape and the nonlinear properties of the 3-D wavenumber/frequency wave spectrum, 24 and the characteristic spatial, temporal and spatio-temporal length scales of the wave field. We then focus on 25 analyzing the probability of occurrence and the spatio-temporal size of the rogue waves we identified in the data. In 26 particular, we provide for the first time an empirical estimate of the extent of the horizontal sea surface spanned by 27 rogue waves. We also propose and assess a novel strategy to determine from the 3-D wave spectrum the vertical 28 current profile, to be then used to map the spectrum on intrinsic frequencies &nbsp

Global Navigation Satellite Systems (GNSS) and modern motion-sensor packages allow the measurement of ocean surface waves with low-cost drifters. Drifting along or across current gradients provides unique measurements of wave-current interactions. In this study, we investigate the response of several combinations of GNSS receiver, motion-sensor package and hull design in order to define a prototype surface kinematic buoy (SKIB) that is particularly optimized for measuring wave-current interactions, including relatively short wave components (relative frequency around 1 Hz) that are important for air-sea interactions and remote sensing applications. The comparison with existing Datawell Directional Waverider and SWIFT buoys, as well as stereo-video imagery demonstrates the accuracy of SKIB. The use of low-cost accelerometers and a spherical ribbed and skirted hull design provide acceptable heave spectra, while velocity estimates from GNSS receivers yield a mean direction and directional spread. Using a low-power acquisition board allows autonomous deployments over several months with data transmitted by satellite. The capability to measure current-induced wave variations is illustrated with data acquired in a macro-tidal coastal environment.

The energy level and its directional distribution are key observations for understanding the energy balance in the wind-wave spectrum between wind-wave generation, nonlinear interactions, and dissipation. Here, properties of gravity waves are investigated from a fixed platform in the Black Sea, equipped with a stereo video system that resolves waves with frequency f up to 1.4 Hz and wavelengths from 0.6 to 11 m. One representative record is analyzed, corresponding to young wind waves with a peak frequency fp = 0.33 Hz and a wind speed of 13 m s−1. These measurements allow for a separation of the linear waves from the bound second-order harmonics. These harmonics are negligible for frequencies f up to 3 times fp but account for most of the energy at higher frequencies. The full spectrum is well described by a combination of linear components and the second-order spectrum. In the range 2fp to 4fp, the full frequency spectrum decays like f−5, which means a steeper decay of the linear spectrum. The directional spectrum exhibits a very pronounced bimodal distribution, with two peaks on either side of the wind direction, separated by 150° at 4fp. This large separation is associated with a significant amount of energy traveling in opposite directions and thus sources of underwater acoustic and seismic noise. The magnitude of these sources can be quantified by the overlap integral I(f), which is found to increase sharply from less than 0.01 at f = 2fp to 0.11 at f = 4fp and possibly up to 0.2 at f = 5fp, close to the 0.5π value proposed in previous studies.

Wave observations and modeling have recently demonstrated that wave extremes of short-crested seas are poorly predicted by statistics of time records. Indeed, the highest waves pertain to wave groups at focusing that have space–time dynamics. Therefore, the statistical prediction of extremes of short-crested sea states should rely on the multidimensional random wave fields’ assumption. To adapt wave extreme statistics to the space–time domain, theoretical models using parameters of the directional wave spectrum have been recently developed. In this paper, the influence of metocean forcings (wind conditions, ambient current, and bottom depth) on these parameters and hence on wave extremes is studied with a twofold strategy. First, parametric spectral formulations [Pierson–Moskowitz and Joint North Sea Wave Project (JONSWAP) frequency spectra with cos2 directional distribution function] are considered to represent the dependence of wave extremes upon wind speed, fetch, and space domain size. Afterward, arbitrary conditions are simulated by using the SWAN numerical model adapted to store the spectral parameters, and the effects on extremes of current- and depth-induced shoaling are investigated. Preliminarily, the space–time extremes prediction model adopted is assessed by means of numerical simulations of Gaussian random seas. Compared to the significant wave height of the sea state and for a given space domain size, results show that space–time extremes are enhanced by opposite currents, whereas they are weakened by increasing wind conditions (wind speed and fetch) and by depth-induced shoaling. In this respect, the remarkable contribution to wave extremes of the size of the space domain is substantiated.

Global navigation satellite systems (GNSSs) and modern motion-sensor packages allow the measurement of ocean surface waves with low-cost drifters. Drifting along or across current gradients provides unique measurements of wave–current interactions. In this study, we investigate the response of several combinations of GNSS receiver, motion-sensor package and hull design in order to define a prototype “surface kinematics buoy” (SKIB) that is particularly optimized for measuring wave–current interactions, including relatively short wave components that are important for air–sea interactions and remote-sensing applications. The comparison with existing Datawell Directional Waverider and Surface Wave Instrument Float with Tracking (SWIFT) buoys, as well as stereo-video imagery, demonstrates the performance of SKIB. The use of low-cost accelerometers and a spherical ribbed and skirted hull design provides acceptable heave spectra E(f) from 0.09 to 1 Hz with an acceleration noise level (2πf)4E(f) close to 0.023 m2 s−3. Velocity estimates from GNSS receivers yield a mean direction and directional spread. Using a low-power acquisition board allows autonomous deployments over several months with data transmitted by satellite. The capability to measure current-induced wave variations is illustrated with data acquired in a macro-tidal coastal environment.

We propose a satellite mission that uses a near-nadir Ka-band Doppler radar to measure surface currents, ice drift and ocean waves at spatial scales of 40 km and more, with snapshots at least every day for latitudes 75 to 82°, and every few days for other latitudes. The use of incidence angles of 6 and 12° allows for measurement of the directional wave spectrum, which yields accurate corrections of the wave-induced bias in the current measurements. The instrument's design, an algorithm for current vector retrieval and the expected mission performance are presented here. The instrument proposed can reveal features of tropical ocean and marginal ice zone (MIZ) dynamics that are inaccessible to other measurement systems, and providing global monitoring of the ocean mesoscale that surpasses the capability of today's nadir altimeters. Measuring ocean wave properties has many applications, including examining wave–current interactions, air–sea fluxes, the transport and convergence of marine plastic debris and assessment of marine and coastal hazards.

Gli autori, coordinati dalla prof.ssa Marinella Pigozzi, analizzano la figura del bolognese Francesco Cavazzoni, pittore e scrittore devoto. Attraverso l’esame di alcuni dipinti, collocano la sua produzione nel contesto culturale coevo e sottolineano la modernità di alcuni suoi soggetti., Figure. Rivista della Scuola di Specializzazione in Beni Storico-Artistici dell'Università di Bologna, Vol 3 (2017)

We propose a new satellite mission that uses a near-nadir Ka-band Doppler radar to measure surface currents, ice drift and ocean waves at spatial scales of 40 km and more, with snapshots at least every day for latitudes 75 to 82, and every few days otherwise. The use of incidence angles at 6 and 12 degrees allows a measurement of the directional wave spectrum which yields accurate corrections of the wave-induced bias in the current measurements. The instrument principle, algorithm for current velocity and mission performance are presented here. The proposed instrument can reveal features on tropical ocean and marginal ice zone dynamics that are inaccessible to other measurement systems, as well as a global monitoring of the ocean mesoscale that surpasses the capability of today’s nadir altimeters. Measuring ocean wave properties facilitates many applications, from wave-current interactions and air-sea fluxes to the transport and convergence of marine plastic debris and assessment of marine and coastal hazards.

Introduction En 2010, l’EUCAST a change les recommendations pour l’interpretation de l’antibiogramme des enterobacteries productrices de beta-lactamase a spectre etendu (E-BLSE), autorisant la prescription d’une cephalosporine de 3e generation ou de l’association d’une betalactamine et d’un inhibiteur de betalactamase comme alternatives aux carbapenemes (AC). L’objectif de cette etude est d’evaluer la frequence et les facteurs associes a la prescription en reanimation d’une AC pour le traitement des bacteriemies a E-BLSE. Materiels et methodes Etude retrospective des patients traites pour une bacteriemie a E-BLSE entre 2011 et 2017 au sein de 5 services de reanimation. Une analyse descriptive et comparative des patients traites par une AC ou par carbapeneme a ete realisee. Resultats Au total 148 patients ont ete inclus. Ils etaient majoritairement des hommes (73 %) avec un âge median de 64 ans. Au diagnostic de la bacteriemie, le score SOFA median etait de 6, le score de Pitt median de 3, et 85 patients (57 %) presentaient un etat de choc. Les isolats d’E-BLSE etaient sensibles a au moins une AC dans 51 % des cas. Un traitement empirique etait debute chez 144 patients, avec une AC chez 53 patients (37 %). Une bitherapie avec un aminoside etait prescrite chez 74 patients (51 %). La proportion de traitement initial approprie etait de 87 % (100 % avec un traitement par un carbapeneme vs 75 % avec une alternative, p Apres l’obtention des resultats de l’antibiogramme, un traitement documente etait prescrit chez 140 patients, par une AC chez 43 patients (31 %). Dix patients traites initialement par un carbapeneme ont recu un traitement definitif par une AC. Les facteurs associes a la prescription d’une AC apres documentation etaient une infection par une E-BLSE sensible a au moins une alternative (84 % vs 41 %, p Conclusion Le traitement par une alternative aux carbapenemes en probabiliste puis de maniere orientee en reanimation represente un tiers des patients. Il ne semble pas que cette strategie entraine un taux de mortalite plus eleve. Ce travail souligne que les reanimateurs sont sensibles a la politique d’epargne des carbapenemes. La publication recente de l’etude MERINO aura probablement un impact sur leur pratique.