Project description:Background and aimsThe increased likelihood and severity of storm events has brought into focus the role of coastal ecosystems in provision of shoreline protection by attenuating wave energy. Canopy-forming kelps, including giant kelp (Macrocystis pyrifera), are thought to provide this ecosystem service, but supporting data are extremely limited. Previous in situ examinations relied mostly on comparisons between nominally similar sites with and without kelp. Given that other factors (especially seafloor bathymetry and topographic features) often differ across sites, efforts to isolate the effects of kelp on wave energy propagation confront challenges. In particular, it can be difficult to distinguish wave energy dissipation attributable to kelp from frictional processes at the seabed that often covary with the presence of kelp. Here, we use an ecological transition from no kelp to a full forest, at a single site with static bathymetry, to resolve unambiguously the capacity of giant kelp to damp waves.MethodsWe measured waves within and outside rocky reef habitat, in both the absence and the presence of giant kelp, at Marguerite Reef, Palos Verdes, CA, USA. Nested within a broader kelp restoration project, this site transitioned from a bare state to one supporting a fully formed forest (density of 8 stipes m-2). We quantified, as a function of incident wave conditions, the decline in wave energy flux attributable to the presence of kelp, as waves propagated from outside and into reef habitat.Key resultsThe kelp forest damped wave energy detectably, but to a modest extent. Interactions with the seabed alone reduced wave energy flux, on average, by 12 ± 1.4 % over 180 m of travel. The kelp forest induced an additional 7 ± 1.2 % decrease. Kelp-associated declines in wave energy flux were slightly greater for waves of longer periods and smaller wave heights.ConclusionsMacrocystis pyrifera forests have a limited, albeit measurable, capacity to enhance shoreline protection from nearshore waves. Expectations that giant kelp forests, whether extant or enhanced through restoration, have substantial impacts on wave-induced coastal erosion might require re-evaluation.
Project description:CSF-venous fistulas - initially described in 2014 - are a significant cause of spontaneous intracranial hypotension. Dynamic lateral decubitus digital subtraction and/or CT myelography typically show a hyperdense paraspinal vein. In case of a central drainage toward the internal vertebral venous plexus, it is the "hyperdense basivertebral vein" which should be searched for carefully.
Project description:Mortality associated with cardiogenic shock can reach 80%. Although most often diagnosed clinically, the hemodynamics of cardiogenic shock may manifest on contrast-enhanced computed tomography as dependent layering of contrast within the inferior vena cava (IVC), a finding referred to as the "IVC level sign." Herein we present 2 cases of the IVC level sign. Swift recognition of the IVC level sign and awareness of its dire prognostic implications is essential for achieving the best patient outcomes.
Project description:Scimitar syndrome consists of anomalous pulmonary vein drainage to the inferior vena cava. Its name derives from the image this anomalous pulmonary vein creates on a chest radiograph. We describe a case of normal venous pulmonary vein drainage that also presented the scimitar sign due to an aorto-collateral vessel. A 15-month-old girl presented with mild dyspnoea and fever. Control chest X-ray showed an image of cardiac dextroposition, hypoplastic right lung, and the 'scimitar sign'. Although the transthoracic echocardiogram confirmed the initial suspicion of anomalous pulmonary venous drainage, the computed tomography (CT) scan showed normal right pulmonary veins connected to the left atrium and revealed that an aorto-collateral vessel caused the scimitar sign. Although the patient had several typical alterations of the scimitar syndrome, the pulmonary venous connection was normal, and the scimitar sign was due to an aorto-collateral vessel. It might be difficult to describe venous pulmonary connections on the basis of echocardiography, so an angio CT scan proved to be a valuable tool in this scenario.
Project description:Lipomas are the most prevalent type of benign soft tissue tumors, primarily composed of adipocytes, and typically remain asymptomatic unless they reach a significant size. Although giant lipomas are infrequent, their occurrence on the chest wall, particularly in the interpectoral region, is exceedingly rare. We present a unique case of a 48-year-old man with a massive interpectoral lipoma measuring 19.4 × 12.9 × 9.4 cm, which resulted in venous thoracic outlet syndrome by compressing the subclavian vein. This case highlights the clinical challenges in diagnosing deep-seated chest wall lipomas and underscores the necessity of considering thoracic outlet syndrome as a potential complication, even in the absence of direct neural or arterial compression. The presentation of thoracic outlet syndrome can vary, and a comprehensive evaluation is imperative for accurate diagnosis and management.
Project description:Optical nonlinearities are one of the most fascinating properties of two-dimensional (2D) materials. While tremendous efforts have been made to find and optimize the second-order optical nonlinearity in enormous 2D materials, opportunities to explore higher-order ones are elusive because of the much lower efficiency. Here, we report the giant high odd-order optical nonlinearities in centrosymmetric correlated van der Waals insulator manganese phosphorus triselenide. When illuminated by two near-infrared femtosecond lasers, the sample generates a series of profound four- and six-wave mixing outputs. The near-infrared third-order nonlinear susceptibility reaches near the highest record values of 2D materials. Comparative measurements to other prototypical nonlinear optical materials [lithium niobate, gallium(II) selenide, and tungsten disulfide] reveal its extraordinary wave mixing efficiency. The wave mixing processes are further used for nonlinear optical waveguide with multicolor emission. Our work highlights the promising prospect for future research of the nonlinear light-matter interactions in the correlated 2D system and for potential nonlinear photonic applications.