Covid-19 Case Statistics in Europe Show Moderate Negative Correlation with Vaccination Level

Based on the statistics of Covid-19 cases and vaccination level in the last quarter of 2021, a moderate negative correlation was detected between the level of vaccination and current and peak case numbers in a number of European health jurisdictions. Statistically significant correlation was detected after taking into account differences in the local phase of the cases curve, by comparing statistics at the similar phase such as near the top of a local wave rather than current. These results may indicate a certain level of effectiveness of vaccines in preventing Covid-19 spread in the population, though analysis of other factors is still needed for a confident conclusion.

Myocardial Injury Complicated by Systolic Dysfunction in a COVID-19-Positive Dog

A six-year-old Cavalier King Charles spaniel was referred with a two-month history of severe exercise intolerance and syncope. Clinical signs had developed during a local wave of coronavirus disease (COVID-19) two weeks after its family members had manifested symptoms of this viral disease and their positivity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed. Cardiologic assessment documented myocardial injury complicated by systolic dysfunction. An extensive diagnostic work-up allowed us to rule out common causes of myocardial compromise, both infective and not. Accordingly, serological and molecular tests aimed at diagnosing SARS-CoV-2 infection were subsequently performed, especially in light of the dog’s peculiar history. Results of such tests, interpreted in the light of previous findings and current knowledge from human medicine, supported a presumptive diagnosis of COVID-19-associated myocardial injury, a clinical entity hitherto poorly described in this species.

Beaches in McMurdo Sound, Antarctica

<p>Modern beaches in McMurdo Sound can be divided into 3 process regimes. Beaches on Ross Island (eastern McMurdo Sound) are characterised by marine processes with little ice modification. On ice-bound western McMurdo Sound, coastal orientation is of paramount importance. Ice thrust features are prominent on south facing beaches, which are open to the predominant wind direction and receive relatively small waves from the fetch restricted south. A greater degree of marine dominance is exhibited by beaches on north facing coasts where sea ice is blown offshore and the beaches are open to the larger storm waves from the eastern Ross Sea. The single most useful indicator of the relative importance of marine and ice processes on the beaches is the roundness of the beach material. Unlike the modern beaches, raised beach ridges at all sites comprise poorly sorted cobbles in a mixed sand and gravel matrix. These are inferred to be storm ridges. In contrast with the raised beaches, the modern beaches on the western side of the Sound have evidence of ice processes on them. This suggests that the modem beach has not experienced the same magnitude storms that produced the raised beaches. The size and frequency of the ridges is a product of the local wave climate. The number of raised beaches at any site is a useful indicator of the paleo-wave climate. More ridges occur in sheltered south facing locations, because they are more protected from open marine conditions, than on beaches in ice-free or north facing locations. When determining the marine limit of a site the most useful features are, low energy marine bedding features (such as flaser bedding) and boulder pavements. Based on inferred process information at the time of deposition, revised estimates of marine limits in McMurdo Sound and a new marine limit at Cape Barne are presented. Because the nature of the raised beaches has not been fully considered by previous authors sea level curves are inaccurate. The reconstruction of the retreat of the Ross Ice Shelf from marine limits in McMurdo Sound shows a three stage stepwise southward retreat of the Ross Ice Shelf. A breakout from somewhere north of Cape Roberts and south of Cape Ross back to Marble Point (on the western side of the Sound) while remaining north of Cape Bird (on the eastern side of the Sound), occurred sometime around 8,000 years ago. Another breakout cleared ice from Cape Bird to somewhere south of Cape Barne and south of Cape Bernacchi around 5,000 years ago. This differs with other authors work (Hall and Denton, 1999, Kellogg et al., 1996, Stuiver et al., 1981) by suggesting a considerably older date for the Ross Ice Sheet retreating from McMurdo Sound. The data presented here suggests that much of McMurdo Sound was ice free about 1,500 years before earlier estimates at about 6,500 years. The effect of the change in deglaciation timing is to reduce isostatic rebound rates. This suggests that there was less ice in McMurdo Sound during the Last Glacial Maximum.</p>

Beaches in McMurdo Sound, Antarctica

<p>Modern beaches in McMurdo Sound can be divided into 3 process regimes. Beaches on Ross Island (eastern McMurdo Sound) are characterised by marine processes with little ice modification. On ice-bound western McMurdo Sound, coastal orientation is of paramount importance. Ice thrust features are prominent on south facing beaches, which are open to the predominant wind direction and receive relatively small waves from the fetch restricted south. A greater degree of marine dominance is exhibited by beaches on north facing coasts where sea ice is blown offshore and the beaches are open to the larger storm waves from the eastern Ross Sea. The single most useful indicator of the relative importance of marine and ice processes on the beaches is the roundness of the beach material. Unlike the modern beaches, raised beach ridges at all sites comprise poorly sorted cobbles in a mixed sand and gravel matrix. These are inferred to be storm ridges. In contrast with the raised beaches, the modern beaches on the western side of the Sound have evidence of ice processes on them. This suggests that the modem beach has not experienced the same magnitude storms that produced the raised beaches. The size and frequency of the ridges is a product of the local wave climate. The number of raised beaches at any site is a useful indicator of the paleo-wave climate. More ridges occur in sheltered south facing locations, because they are more protected from open marine conditions, than on beaches in ice-free or north facing locations. When determining the marine limit of a site the most useful features are, low energy marine bedding features (such as flaser bedding) and boulder pavements. Based on inferred process information at the time of deposition, revised estimates of marine limits in McMurdo Sound and a new marine limit at Cape Barne are presented. Because the nature of the raised beaches has not been fully considered by previous authors sea level curves are inaccurate. The reconstruction of the retreat of the Ross Ice Shelf from marine limits in McMurdo Sound shows a three stage stepwise southward retreat of the Ross Ice Shelf. A breakout from somewhere north of Cape Roberts and south of Cape Ross back to Marble Point (on the western side of the Sound) while remaining north of Cape Bird (on the eastern side of the Sound), occurred sometime around 8,000 years ago. Another breakout cleared ice from Cape Bird to somewhere south of Cape Barne and south of Cape Bernacchi around 5,000 years ago. This differs with other authors work (Hall and Denton, 1999, Kellogg et al., 1996, Stuiver et al., 1981) by suggesting a considerably older date for the Ross Ice Sheet retreating from McMurdo Sound. The data presented here suggests that much of McMurdo Sound was ice free about 1,500 years before earlier estimates at about 6,500 years. The effect of the change in deglaciation timing is to reduce isostatic rebound rates. This suggests that there was less ice in McMurdo Sound during the Last Glacial Maximum.</p>

Reinterpreting the Bruun Rule in the Context of Equilibrium Shoreline Models

Long-term (>decades) coastal recession due to sea-level rise (SLR) has been estimated using the Bruun Rule for nearly six decades. Equilibrium-based shoreline models have been shown to skillfully predict short-term wave-driven shoreline change on time scales of hours to decades. Both the Bruun Rule and equilibrium shoreline models rely on the equilibrium beach theory, which states that the beach profile shape equilibrates with its local wave and sea-level conditions. Integrating these two models into a unified framework can improve our understanding and predictive skill of future shoreline behavior. However, given that both models account for wave action, but over different time scales, a critical re-examination of the SLR-driven recession process is needed. We present a novel physical interpretation of the beach response to sea-level rise, identifying two main contributing processes: passive flooding and increased wave-driven erosion efficiency. Using this new concept, we analyze the integration of SLR-driven recession into equilibrium shoreline models and, with an idealized test case, show that the physical mechanisms underpinning the Bruun Rule are explicitly described within our integrated model. Finally, we discuss the possible advantages of integrating SLR-driven recession models within equilibrium-based models with dynamic feedbacks and the broader implications for coupling with hybrid shoreline models.

A study on the drag coefficient in wave attenuation by vegetation

Vegetation in wetlands is a large-scale nature-based resource providing a myriad of services for human beings and the environment, such as dissipating incoming wave energy and protecting coastal areas. For understanding wave height attenuation by vegetation, there are two main traditional calibration approaches to the drag effect acting on the vegetation. One of them is based on the rule that wave height decays through the vegetated area by a reciprocal function and another by an exponential function. In both functions, the local wave height reduces with distance from the beginning of the vegetation depending on damping factors. These two damping factors, which are usually obtained from calibration by measured local wave height, are linked to the drag coefficient and measurable parameters, respectively. So the drag coefficient that quantifies the effect of the vegetation can be calculated by different methods, followed by connecting this coefficient to hydraulic parameters to make it predictable. In this study, two relations between these two damping factors and methods to calculate the drag coefficient have been investigated by 99 laboratory experiments. Finally, relations between the drag coefficient and relevant hydraulic parameters were analyzed. The results show that emergent conditions of the vegetation should be considered when studying the drag coefficient; traditional methods which had overlooked this condition cannot perform well when the vegetation was emerged. The new method based on the relation between these two damping factors performed as well as the well-recognized method for emerged and submerged vegetation. Additionally, the Keulegan–Carpenter number can be a suitable hydraulic parameter to predict the drag coefficient and only the experimental setup, especially the densities of the vegetation, can affect the prediction equations.

The local wave phenomenon in the quintic nonlinear Schrödinger equation by numerical methods

The nonlinear Schrodinger hierarchy has a wide range of applications in modeling the propagation of light pulses in optical fibers. In this paper, we focus on the integrable nonlinear Schrodinger (NLS) equation with quintic terms, which play a prominent role when the pulse duration is very short. First, we investigate the spectral signatures of the spatial Lax pair with distinct analytical solutions and their periodized wavetrains by Fourier oscillatory method. Then, we numerically simulate the wave evolution of the quintic NLS equation from different initial conditions through the symmetrical split-step Fourier method. We find many localized high-peak structures whose profiles are very similar to the analytical solutions, and we analyze the formation of rouge waves (RWs) in different cases. These results may be helpful to understand the excitation of nonlinear waves in some nonlinear fields, such as optical fibers, oceanography and so on.

Resonance Y-shaped soliton and interaction solutions in the (2 + 1)-dimensional B-type Kadomtsev–Petviashvili equation

The ([Formula: see text])-dimensional B-type Kadomtsev–Petviashvili (BKP) equation is utilized to depict weakly dispersive waves propagating in the fluid mechanics. According to [Formula: see text]-soliton solutions, resonance Y-shaped soliton and its interaction with other local wave solutions of the ([Formula: see text])-dimensional BKP equation are derived by introducing the constraint conditions. These types of hybrid soliton solutions exhibit the complex interaction phenomenon among resonance Y-shaped solitons, breather waves, line solitary waves and high-order lump waves. The dynamic behaviors of such interaction solutions are analyzed and illustrated.

COMPARATIVE STUDY FOR WAVE SPEED ESTIMATION AT A SINGLE AND TWO MEASUREMENT POINTS

Local wave speed is a prognostic detector that allows the analysis of cardiovascular function. Objectives: This study compared wave speed ([Formula: see text] measurements at single-point and two-point techniques. Material and methods: [Formula: see text] were determined from the cepstral analysis of the blood flow velocities, which identified the arrivals times of reflected waves. The blood velocities waveforms were measured by using phase-contrast magnetic resonance (PCMR) for 20 subjects on young and old healthy subjects. Local wave speed was estimated through the arrivals time of reflections waves ([Formula: see text] and the distance separating the measurement site to reflection area ([Formula: see text] or the distance separating the two measurement sites. Results: Our obtained results were in total agreement with reference values reported in the literature. Moreover, the detected results show that there is a high correlation ([Formula: see text]) between the two methods. Conclusion: The analysis of the wave speed variations with advancing age is also achieved out through different regression models.