Observation of a Group of Dark Rogue Waves in a Telecommunication Optical Fiber

Over the past decade, the rogue wave debate has stimulated the comparison of predictions and observations among different branches of wave physics, particularly between hydrodynamics and optics, in situations where analogous dynamical behaviors can be identified, thanks to the use of common universal models. Although the scalar nonlinear Schroedinger equation (NLSE) has constantly played a central role for rogue wave investigations, moving beyond the standard NLSE model is relevant and needful for describing more general classes of physical systems and applications. In this direction, the coupled NLSEs are known to play a pivotal role for the understanding of the complex wave dynamics in hydrodynamics and optics. Benefiting from the advanced technology of high-speed telecommunication-grade components, and relying on a careful design of the nonlinear propagation of orthogonally-polarized optical pump waves in a randomly birefringent telecom fiber, this work explores, both theoretically and experimentally, the rogue wave dynamics governed by such coupled NLSEs. We report, for the first time, the evidence of a group of three dark rogue waves, the so-called dark three-sister rogue waves, where experiments, numerics, and analytics show a very good consistency

Handmade clay bricks: chemical, physical and mechanical properties

The clay brick masonry that is much used in historical structures often is in a rather poor state of conservation. In order to intervene correctly in these buildings, it is convenient to characterize the old material. For this purpose, a large sample of clay brick specimens from the 12th to 19th century were collected from six Portuguese monasteries, and were characterized chemically, physically and mechanically. A large variability of the properties was found. Additionally, a sample of handmade new bricks, which are commonly used as replacing material, was also analysed. The results were compared to the old bricks and could be possibly adequate as substitution bricks. Still, significant differences were found in chemical composition, and in water absorption and porosity, which are much lower in modern handmade bricks. With respect to mechanical properties, the range of values found in old bricks was rather high and the degree of deterioration exhibited a large scatter, meaning that a conclusion is hardly possible.The authors gratefully acknowledge the Instituto de Gestao do Patrimonio Arquitectonico e Arqueologico (IGESPAR) for providing the old clay bricks used in the present work. The first author acknowledges the partial funding of this work by the FCT through the following scholarships POCTI SFRH/BD/6409/2001 and POCTI SFRH/BPD/26706/2005

Polarization modulation instability in a Manakov fiber system

The Manakov model is the simplest multicomponent model of nonlinear wave theory: It describes elementary stable soliton propagation and multisoliton solutions, and it applies to nonlinear optics, hydrodynamics, and Bose-Einstein condensates. It is also of fundamental interest as an asymptotic model in the context of the widely used wavelength-division-multiplexed optical fiber transmission systems. However, although its physical relevance was confirmed by the experimental observation of Manakov (vector) solitons in a planar waveguide in 1996, there have in fact been no quantitative experiments confirming its validity for nonlinear dynamics other than soliton formation. Here, we report experiments in optical fiber that provide evidence of passband and baseband polarization modulation instabilities in a defocusing Manakov system. In the spontaneous regime, we also reveal a unique saturation effect as the pump power increases. We anticipate that such observations may impact the application of this minimal model to describe and understand more complicated phenomena in nature, such as the formation of extreme waves in multicomponent systems

Spatial beam self-cleaning in second-harmonic generation

We experimentally demonstrate the spatial self-cleaning of a highly multimode optical beam, in the process of second-harmonic generation in a quadratic nonlinear potassium titanyl phosphate crystal. As the beam energy grows larger, the output beam from the crystal evolves from a highly speckled intensity pattern into a single, bell-shaped spot, sitting on a low energy background. We demonstrate that quadratic beam cleanup is accompanied by significant self-focusing of the fundamental beam, for both positive and negative signs of the linear phase mismatch close to the phase-matching condition

Late histological findings in symptomatic COVID-19 patients: A case report

RATIONALE: Although there have been several studies describing clinical and radiographic features about the novel coronavirus (COVID-19) infection, there is a lack of pathologic data conducted on biopsies or autopsies. PATIENT CONCERNS: A 56-year-old and a 70-year-old men with fever, cough, and respiratory fatigue were admitted to the intensive care unit and intubated for respiratory distress. DIAGNOSIS: The nasopharyngeal swab was positive for COVID-19 and the chest Computed Tomography (CT) scan showed the presence of peripheral and bilateral ground-glass opacities. INTERVENTIONS: Both patients developed pneumothoraces after intubation and was managed with chest tube. Due to persistent air leak, thoracoscopies with blebs resection and pleurectomies were performed on 23rd and 16th days from symptoms onset. OUTCOMES: The procedures were successful with no evidence of postoperative air-leak, with respiratory improvement. Pathological specimens were analyzed with evidence of diffuse alveolar septum disruption, interstitium thickness, and infiltration of inflammatory cells with diffuse endothelial dysfunction and hemorrhagic thrombosis. LESSONS: Despite well-known pulmonary damages induced by the COVID-19, the late-phase histological changes include diffused peripheral vessels endothelial hyperplasia, in toto muscular wall thickening, and intravascular hemorrhagic thrombosis

Spatial beam reshaping and spectral broadening in quadratic crystals

Nonlinear optics in crystals with quadratic susceptibility has been largely explored along the last decades, with a particular emphasis on spatial solitons. When in the initial part of the propagation, the nonlinear length is much shorter than the diffraction length, rather than solitons, in these crystals it is possible to observe strong beam reshaping and spectral broadening. This mechanism of nonlinear beam evolution can be induced by combining high laser energies and large input diameters, so to reduce the contribution of diffraction in the initial steps of the propagation

Avaliação de formulações de iscas tóxicas para a supressão populacional de Ceratitis capitata (Wied., 1824) (Diptera: Tephritidae) em uva fina de mesa.

A mosca-do-mediterrâneo Ceratitis capitata é a principal praga da cultura da videira na região do Submédio São Francisco. Nesse estudo de caso, foi avaliado o efeito de formulações de iscas tóxicas de pronto uso (Gelsura® e Success* 0.02CB®) e do atrativo Anamed® associado ao inseticida espinosade (Tracer®) na supressão populacional de C. capitata em uva fina de mesa da cultivar Sugar Crisp® em Lagoa Grande, BA

NFKB1 regulates human NK cell maturation and effector functions

12siopenopenLougaris, Vassilios; Patrizi, Ornella; Baronio, Manuela; Tabellini, Giovanna; Tampella, Giacomo; Damiati, Eufemia; Frede, Natalie; van der Meer, Jos W.M.; Fliegauf, Manfred; Grimbacher, Bodo; Parolini, Silvia; Plebani, AlessandroLougaris, Vassilios; Patrizi, Ornella; Baronio, Manuela; Tabellini, Giovanna; Tampella, Giacomo; Damiati, Eufemia; Frede, Natalie; van der Meer, Jos W. M.; Fliegauf, Manfred; Grimbacher, Bodo; Parolini, Silvia; Plebani, Alessandr