Max flow vitality in general and stst-planar graphs

The \emph{vitality} of an arc/node of a graph with respect to the maximum flow between two fixed nodes $s$ and $t$ is defined as the reduction of the maximum flow caused by the removal of that arc/node. In this paper we address the issue of determining the vitality of arcs and/or nodes for the maximum flow problem. We show how to compute the vitality of all arcs in a general undirected graph by solving only $2(n-1)$ max flow instances and, In $st$-planar graphs (directed or undirected) we show how to compute the vitality of all arcs and all nodes in $O(n)$ worst-case time. Moreover, after determining the vitality of arcs and/or nodes, and given a planar embedding of the graph, we can determine the vitality of a `contiguous' set of arcs/nodes in time proportional to the size of the set.Comment: 12 pages, 3 figure

Matter around Kerr black holes in scalar-tensor theories: scalarization and superradiant instability

In electrovacuum stationary, asymptotically flat black holes in scalar-tensor theories of gravity are described by the Kerr-Newman family of solutions, just as in general relativity. We show that there exist two mechanisms which can render Kerr black holes unstable when matter is present in the vicinity of the black hole, as this induces an effective mass for the scalar. The first mechanism is a tachyonic instability that appears when the effective mass squared is negative, triggering the development of scalar hair --- a black hole version of "spontaneous scalarization". The second instability is associated with superradiance and is present when the effective mass squared is positive and when the black hole spin exceeds a certain threshold. The second mechanism is also responsible for a resonant effect in the superradiant scattering of scalar waves, with amplification factors as large as 10^5 or more.Comment: 11 pages, 3 figures. v2: published versio

Black holes with surrounding matter in scalar-tensor theories

We uncover two mechanisms that can render Kerr black holes unstable in scalar-tensor gravity, both associated to the presence of matter in the vicinity of the black hole and the fact that this introduces an effective mass for the scalar. Our results highlight the importance of understanding the structure of spacetime in realistic, astrophysical black holes in scalar-tensor theories.Comment: 5 pages. Published version. arXiv admin note: substantial text overlap with arXiv:1305.693

Fuel on the Invention Funnel: Technology Licensing-in, Antecedents and Invention

In this paper, we examine the impact of technology licensing-in on firm invention performance. Studying a sample of 266 licensees and matched non-licensees using a two-part model specification, we find that licensees are more likely to introduce inventions than their non-licensee counterparts. This holds both if we consider invention in general, and invention in the licensed technological class only. We also show that familiarity with the licensed technology and technological specialization drives licensees to pursue a narrow invention strategy primarily focusing on the technological class specified in the license agreement.Licensing-in, Invention, Dynamic Capabilities, Learning Opportunities, Technological familiarity, Technological specialization

Secondary hypertension as a cause of treatment resistance

In secondary hypertension, elevated blood pressure is caused by a known and/or potentially treatable underlying disease.Although the prevalence of secondary hypertension depends on the patient population and the thoroughness of applied diagnostic approaches, arterial hypertension is classified in 90 to 95% as primary in nature. In young patients, individuals without a family history of hypertension, late onset of hypertension or worsening of a previous well-controlled hypertension as well as in patients who have a difficult to treat hypertension, the prevalence of secondary hypertension is significantly higher.Because the identification and the specific therapy of secondary hypertension may result in normalisation or improvement of elevated blood pressure in many cases, a targeted diagnostics is of great importance

Breast cancer or metastasis? An unusual case of metastatic malignant pleural mesothelioma to the breast

Background: Metastases to the breast from extramammary malignancies are very rare, and ruling out the diagnosis of primary breast tumor is important in order to decide on clinical management and predict prognosis. Case presentation: Clinical examination revealed in a 49-year-old hairdresser a 3-cm hard lump adherent to the underlying layers in the right breast. Trucut biopsy was performed. Histology showed a solid proliferation of medium-sized neoplastic polygonal cells. Immunohistochemical analysis showed tumor cells diffusely positive for cytokeratin 8/18 and calretinin and focally positive for cytokeratin 5/6 and Wilms’ tumor 1, e-cadherin, and human bone marrow endothelial-1. Estrogen receptors and progesterone receptors were negative. The final diagnosis was metastatic epithelioid malignant pleural mesothelioma. Conclusions: Immunohistochemistry is an important tool for a conclusive diagnosis of malignant pleural mesothelioma. Owing to the degree of histological and immunohistochemical overlap, a high level of clinical suspicion is essential in order to avoid unnecessary mutilating surgery

Can Silent Brain Lesions Be a Target to Guide Anticoagulation Treatment in Patients With Low-Risk Atrial Fibrillation to Reduce Cognitive Impairment?

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Una finestra sulla vita nel buio. Didattica e divulgazione allo Speleovivarium

Il museo “Speleovivarium” raccoglie e custodisce testimonianze vive del sottosuolo carsico con finalità divulgative, didattiche, di studio e di ricerca, in particolare sul comportamento degli straordinari esseri che popolano le tenebre. Esso si trova in una galleria dalle condizioni climatiche ed ambientali simili ad una cavità carsica; è stato ideato da Erwin Pichl e creato nell’ambito della Società Adriatica di Speleologia nel 1990, con l’obiettivo di promuovere e divulgare le conoscenze del mondo sotterraneo, per il più ampio rispetto della natura dei sottosuoli carsici e non.The “Speleovivarium” museum collects and preserves living witnesses of the Karst underground, for diffusion, teaching, study and research purposes, particularly focusing on the behaviour of the extraordinary creatures that live in the darkness. The museum is located in a cave resembling the climatic and environment conditions of a Karst cavity; it was designed by Erwin Pichl and created by the Adriatic Speleological Society in 1990, with the aim of promoting and sharing knowledge of the subterranean world and develop greater respect for underground nature in the Karst and non-Karst areas