Capturing the Edge of Chaos as a Spectral Submanifold in Pipe Flows

An extended turbulent state can coexist with the stable laminar state in pipe flows. We focus here on short pipes with additional discrete symmetries imposed. In this case, the boundary between the coexisting basins of attraction, often called the edge of chaos, is the stable manifold of an edge state, which is a lower-branch traveling wave solution. We show that a low-dimensional submanifold of the edge of chaos can be constructed from velocity data using the recently developed theory of spectral submanifolds (SSMs). These manifolds are the unique smoothest nonlinear continuations of nonresonant spectral subspaces of the linearized system at stationary states. Using very low dimensional SSM-based reduced-order models, we predict transitions to turbulence or laminarization for velocity fields near the edge of chaos.Comment: Accepted for publication in the Journal of Fluid Mechanic

Nonlinear Model Reduction to Fractional and Mixed-Mode Spectral Submanifolds

A primary spectral submanifold (SSM) is the unique smoothest nonlinear continuation of a nonresonant spectral subspace $E$ of a dynamical system linearized at a fixed point. Passing from the full nonlinear dynamics to the flow on an attracting primary SSM provides a mathematically precise reduction of the full system dynamics to a very low-dimensional, smooth model in polynomial form. A limitation of this model reduction approach has been, however, that the spectral subspace yielding the SSM must be spanned by eigenvectors of the same stability type. A further limitation has been that in some problems, the nonlinear behavior of interest may be far away from the smoothest nonlinear continuation of the invariant subspace $E$. Here we remove both of these limitations by constructing a significantly extended class of SSMs that also contains invariant manifolds with mixed internal stability types and of lower smoothness class arising from fractional powers in their parametrization. We show on examples how fractional and mixed-mode SSMs extend the power of data-driven SSM reduction to transitions in shear flows, dynamic buckling of beams and periodically forced nonlinear oscillatory systems. More generally, our results reveal the general function library that should be used beyond integer-powered polynomials in fitting nonlinear reduced-order models to data.Comment: To appear in Chao

When the Earth goes white: the Snowball Earth attractor

Using an intermediate complexity climate model we investigate the so-called snowball Earth transition. For certain values (including its current value) of the solar constant, the climate system allows two different stable states: one of them is the snowball Earth, covered by ice and snow, and the other one is today's climate

The Impact of Organizational Culture on the Opportunities and Threats in Digital Transformation

Purpose: The aim of the research is to show how the individual elements of the organizational culture - learning organization - affect the opportunities and threats related to the introduction of Industry 4.0. Study design/methodology/approach: A structured questionnaire was used to survey Hungarian companies. The online questionnaire with closed and measurable scale questions were created and distributed. Questions covered following: perceived and detected threats that may hinder organizations in the digital transition process, the benefits that businesses see as an opportunity in the digital transformation, by examining the most important variables of learning organizations and the opportunities and dangers of digital transformation. As a result, survey received a positive feedback with 639 fully completing the questionnaire. Measurement was performed using IBM SPSS Statistics (Version 22.) In the first stage of the research, an Opportunities and a Threats factor were created using principal component analysis. As a result, instead of seven and twelve variables, one can be used to examine additional relationships. In the next stage of the research, we examined how each element of the organizational culture (Organizational Culture - Learning Organization) affects the factors we created, what percentage they contribute to the formation of each factor. The measurement was performed by linear regression analysis. Findings: A comparison of two queries was performed, the results of which are summarized below. (A) How do certain elements of the organizational culture affect companies’ the Industry 4.0 Opportunities? (B) How do certain elements of the organizational culture affect companies’ Industry 4.0 Threats? In „A” case, the organizational culture factors explain 15.1% (R Square = .151) of the companies' Opportunity Factor. After the 5th modeling of the program, there are 5 Organizational Culture variables that significantly contribute to the Opportunities of companies. In „B” case, the Organizational Culture factors explain only 5.6% (R Square = .056) of the companies’ Threats Factor. Following the 7th modeling of the program, there are 3 Organizational Culture variables that contribute significantly to the Threats of companies, Originality/value: The five Organizational Culture variables that significantly contribute to the Opportunities of companies are: The organization proactively anticipates change, The organization is looking for innovative, new solutions, not limited by the habit, The organization also focuses on long-term impacts when making decisions, In the operation and development of the organization, the effects of the changes on other organizational units are taken into account and, The aim is to jointly develop the learning and development skills of the members of the organization, group learning. The three Organizational Culture variables that contribute significantly to the Threats of companies are: The organization is open to environmental change, The aim is to jointly develop the learning and development skills of the members of the organization, Employees can act to achieve their personal vision, ie. free self-realization

Localized Amyloidosis of the Upper Aerodigestive Tract : Complex Analysis of the Cellular Infiltrate and the Amyloid Mass

The aim of this study was to analyse the composition of amyloid mass and the plasmacytic infiltrate of localized amyloidosis of the upper aerodigestive tract.Biopsy materials were studied by light microscopy, immunohistochemistry (IHC), and mRNA in situ hybridization (mRNA-ISH). The amyloid mass was also analysed with high-performance liquid chromatography mass spectrometry- (HPLC-MS-) based proteomics.Nodular and diffuse forms of amyloid deposition were detected. IHC analysis revealed λ-light chain (LC) in two cases, κ-LC in one case. The remaining two were positive with both. Proteins, well known from other amyloidoses like amyloid A (AA), prealbumin/transthyretin (PA), apolipoprotein A-I (ApoAI), and amyloid P component (APC), and also keratin were found with variable intensities in the cases. HPLC-MS revealed dozens of proteins with both LCs in all the lesions but sometimes with surprisingly small intensities. mRNA-ISH analysis revealed identical λ and κ dominance and only one normal κ/λ cell ratio.Cellular infiltrate and protein components in the amyloid showed congruent results in all but one case. The only exception with normal cell ratio and λ-dominant amyloid could be originated from the different protein-secreting activity of plasma cell clones. HPLC-MS analysis explored both LCs in all the amyloid in variable amount, but other proteins with much higher intensities like keratins, apolipoprotein A-IV (ApoAIV), were also detected. Proteins like AA, PA, ApoAI, and APC, previously known about amyloid-forming capability, also appeared. This indicates that localized amyloid in the upper aerodigestive tract is not a homogenous immunoglobulin mass but a mixture of proteins. The sometimes very low light chain intensities might also suggest that not all the localized amyloidosis cases of the upper aerodigestive tract are of convincingly AL type, and the analysis of the cellular infiltrate might indicate that not all are monoclonal

Rosszindulatúan elfajult nyaki branchiogen cysts

A nyaki branchiogen cysta az egyik leggyakoribb nyaki fejlődési rendellenesség. Ismert a malignus elfajulása, melynek diagnosztizálására, az ismeretlen lokalizációjú primer laphámcarcinoma nyaki áttététől való elkülönítésére szigorú kritériumrendszerek léteznek. Ugyanakkor a szakirodalomban a diagnózis létjogosultsága a mai napig vita tárgyát képezi. Közleményünkben egy 69 éves nőbeteg esetét ismertetjük, aki bal oldali, állkapocs alatti duzzanat miatt jelentkezett Klinikánkon. Hosszas kivizsgálást követően felmerült ismeretlen primer tumor nyaki áttétének gyanúja, mely miatt pánendoszkópiát és módosított radikális nyaki dissectiót végeztünk. Végül a szövettani feldolgozást köve- tően lateralis nyaki cysta talaján kialakult laphámcarcinoma igazolódott. A műtétet követően a beteg adjuváns kemo- terápiában és sugárkezelésben részesült. Az eset kapcsán ismertetjük a diagnózis felállításának nehézségeit, differenciáldiagnosztikai problémáit és a kapcsolódó nemzetközi irodalmat

Wegener-granulomatosis talaján kialakult krónikus gennyes középfülgyulladás komplex kezelése = Modern management of otologic consequences of Wegener’s granulomatosis – a case report and review of the literature

Absztrakt: A Wegener-granulomatosis – újabb nevén polyangitis granulomatosis – súlyos, antineutrofil citoplazmatikus antitest asszociálta, kis ereket érintő vasculitis, melyet a légúti traktus és a renalis rendszer nekrotizáló, granulomatosus gyulladása jellemez. A fülészeti manifesztációk a kórkép korai fázisában fordulhatnak elő, melyek közül a leggyakrabban savós középfülgyulladás, maszkolt otomastoiditis, esetenként sensorineuralis halláscsökkenés jelentkezhet. A diagnózis felállítása a klinikai képen, az immunszerológiai, valamint a hisztopatológiai vizsgálatokon alapszik. A kombinált immunszuppresszív terápia mellett a lokális manifesztációk szanálása szükséges. A terápiarezisztens, Wegener-granulomatosis talaján kialakult elhúzódó középfülgyulladás gyakran komoly kihívás elé állítja a fül-orr-gégészt. Ilyen esetekben a felkészült fülsebész kezében stabil megoldást jelent a subtotalis petrosectomia, amellyel zárt, reakciómentes középfül kerül kialakításra, s abban szimultán vagy halasztottan végezhető hallásrehabilitáció modern, implantálható hallásjavító készülékekkel. A jelen közleményben a szerzők áttekintik a vonatkozó irodalmat és egy esetbemutatáson keresztül ismertetik a Wegener-granulomatosis fülészeti megjelenésének komplex ellátását a modern szakmai szemlélet jegyében. Orv Hetil. 2019; 160(4): 151–157. | Abstract: Wegener’s granulomatosis – or, in other words, granulomatosis with polyangiitis – is an anti-neutrophil cytoplasmic antibody associated granuloma forming vasculitis, mainly affecting the respiratory tract and the renal system. Otologic manifestations of Wegener’s disease can be otitis media with effusion or chronic silent mastoiditis with conductive hearing loss, but sensorineural hearing loss can also evolve. The diagnosis is based on the clinical appearance as well as the immunoserological and histopathological results. It is of paramount importance to begin a combined immunosuppressive treatment immediately, besides eradicating the otologic manifestations. The intractable cases of chronic otitis media due to Wegener’s granulomatosis are challenging any ear surgeons. Subtotal petrosectomy has proved to be an effective solution in such cases to create a dry ear and to provide a safe surgical field for hearing restoration. The authors reviewed the literature and report a case history to present the modern management of Wegener’s granulomatosis with otologic manifestation. Orv Hetil. 2019; 160(4): 151–157

PACAP and PAC1 Receptor Expression in Human Insulinomas

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread occurrence and diverse functions. PACAP binds to specific PAC1 and non-specific VPAC1/2 receptors. PACAP is considered as a growth factor, as it plays important roles during development and participates in reparative processes. Highest concentrations are found in the nervous system and endocrine glands, where several functions are known, including actions in tissue growth, differentiation and tumour development. Therefore, we have investigated expression of PACAP and its receptors in different tumours, including those of endocrine glands. We showed earlier that PACAP and PAC1 receptor staining intensity decreased in pancreatic ductal adenocarcinoma. In the present study we aimed to investigate alterations of PACAP and PAC1 receptor in human insulinoma and compared the immunostaining pattern with samples from chronic pancreatitis patients. We collected perioperative and histological data of patients who underwent operation because of insulinoma or chronic pancreatitis over a five-year-long period. Histology showed chronic pancreatitis with severe scar formation in pancreatitis patients, while tumour samples evidenced Grade 1 or 2 insulinoma. PACAP and PAC1 receptor expression was studied using immunohistochemistry. Staining intensity was very strong in the Langerhans islets of normal tissue and discernible staining was also observed in the exocrine pancreas. Immunostaining intensity for both PACAP and PAC1 receptor was markedly weaker in insulinoma samples, and disappeared from chronic pancreatitis samples except for intact islets. These findings show that PAC1 receptor/PACAP signalling is altered in insulinoma and this suggests a possible involvement of this system in tumour growth or differentiation

Combined two-photon imaging, electrophysiological, and anatomical investigation of the human neocortex in vitro

Spontaneous synchronous population activity (SPA) can be detected by electrophysiological methods in cortical slices of epileptic patients, maintained in a physiological medium in vitro. In order to gain additional spatial information about the network mechanisms involved in the SPA generation, we combined electrophysiological studies with two-photon imaging. Neocortical slices prepared from postoperative tissue of epileptic and tumor patients were maintained in a dual perfusion chamber in a physiological incubation medium. SPA was recorded with a 24-channel extracellular linear microelectrode covering all neocortical layers. After identifying the electrophysiologically active regions of the slice, bolus loading of neuronal and glial markers was applied on the tissue. SPA-related [Formula: see text] transients were detected in a large population of neighboring neurons with two-photon microscopy, simultaneous with extracellular SPA and intracellular whole-cell patch-clamp recordings. The intracellularly recorded cells were filled for subsequent anatomy. The cells were reconstructed in three dimensions and examined with light- and transmission electron microscopy. Combining high spatial resolution two-photon [Formula: see text] imaging techniques and high temporal resolution extra- and intracellular electrophysiology with cellular anatomy may permit a deeper understanding of the structural and functional properties of the human neocortex