On Resilient Behaviors in Computational Systems and Environments

The present article introduces a reference framework for discussing resilience of computational systems. Rather than a property that may or may not be exhibited by a system, resilience is interpreted here as the emerging result of a dynamic process. Said process represents the dynamic interplay between the behaviors exercised by a system and those of the environment it is set to operate in. As a result of this interpretation, coherent definitions of several aspects of resilience can be derived and proposed, including elasticity, change tolerance, and antifragility. Definitions are also provided for measures of the risk of unresilience as well as for the optimal match of a given resilient design with respect to the current environmental conditions. Finally, a resilience strategy based on our model is exemplified through a simple scenario.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/s40860-015-0002-6 The paper considerably extends the results of two conference papers that are available at http://ow.ly/KWfkj and http://ow.ly/KWfgO. Text and formalism in those papers has been used or adapted in the herewith submitted pape

Maximally multipartite entangled states

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.Comment: 5 pages, 1 figure, final verso

Probability density function characterization of multipartite entanglement

We propose a method to characterize and quantify multipartite entanglement for pure states. The method hinges upon the study of the probability density function of bipartite entanglement and is tested on an ensemble of qubits in a variety of situations. This characterization is also compared to several measures of multipartite entanglement.Comment: 7 pages, 2 figures; published version; title changed; further explanations and comparison with several measures of multipartite entanglement adde

Characterizing and measuring multipartite Entanglement

A method is proposed to characterize and quantify multipartite entanglement in terms of the probability density function of bipartite entanglement over all possible balanced bipartitions of an ensemble of qubits. The method is tested on a class of random pure states.Comment: 7 pages, 5 figures. Submitted to "International Journal of Quantum Information

Multipartite entanglement characterization of a quantum phase transition

A probability density characterization of multipartite entanglement is tested on the one-dimensional quantum Ising model in a transverse field. The average and second moment of the probability distribution are numerically shown to be good indicators of the quantum phase transition. We comment on multipartite entanglement generation at a quantum phase transition.Comment: 10 pages, 6 figures, final versio

PARAMETRICAL ANALYSIS AND DIGITAL FABRICATION OF THIN SHELL STRUCTURES: THE IMPACT OF CONSTRUCTION TECHNIQUE ON THE RESULTING GEOMETRY OF THE GAUSSIAN VAULTS OF ELADIO DIESTE

Abstract. The objective of this article is to analyze the state-of-art regarding the construction process of the Gaussian Vaults of the Uruguayan civil engineer Eladio Dieste and to identify the elements that underlie the relationship between the constructive techniques and procedures within this specific structural typology and its resulting geometry. As complementary objectives, this research aims for the identification of the gaps in the registry of such constructive procedures. The essay focuses on the geometry of the Gaussian Vaults designed and built by Dieste, in a way that these rigid structural surfaces' geometry had their original construction drawings redrawn and analyzed from the perspective of its construction technique by means of the Parametrical Modelling and Digital Fabrication of case studies.</p

Primary Cultures from Human GH-secreting or Clinically Non-functioning Pituitary Adenomas

Pituitary adenomas are among the more frequent intracranial tumors usually treated with both surgical and pharmacological\u2013based on somatostatin and dopamine agonists\u2013approaches. Although mostly benign tumors, the occurrence of invasive behaviors is often detected resulting in poorer prognosis. The use of primary cultures from human pituitary adenomas represented a significant advancement in the knowledge of the mechanisms of their development and in the definition of the determinants of their pharmacological sensitivity. Moreover, recent studies identified also in pituitary adenomas putative tumor stem cells representing, according to the current hypothesis, the real cellular targets to eradicate most malignancies. In this protocol, we describe the procedure to establish primary cultures from human pituitary adenomas, and how to select, in vitro expand, and phenotypically characterize putative pituitary adenoma stem cells

INVESTIGATIONS ON THE DESIGN PROCESS OF ELADIO DIESTE: 3D PARAMETRIC MODELLING OF MODERN LATIN AMERICAN ARCHITECTURAL HERITAGE

Abstract. The Uruguayan Engineer Eladio Dieste underwent a quest for thinness in the field of structural design which rendered his reinforced masonry thin-shell structures at a conspicuous position in Modern Latin American Architectural Heritage, so much so as to have Dieste's work in Latin America and Europe included in an indicative list for UNESCO's cultural heritage sites as of 2010. Nonetheless, the design process that led Dieste to such innovative structural typologies is yet to be fully academically explored. Thus, the objective of this paper is to examine the state-of-art regarding the intricate design process of Eladio Dieste's gaussian vaults and shed some light on the existing gaps within this process by means of the 3D parametric modelling and digital fabrication of selected case studies. The adoption methodological procedures such as 3D parametrical modelling and digital fabrication allows for the establishment of important relationships between the design process and the resulting geometry of Eladio Dieste's designs, as well as furthering registry of Dieste's legacy for conservation purposes.</p

Experimental Evidence and Clinical Implications of Pituitary Adenoma Stem Cells

Pituitary adenomas, accounting for 15% of diagnosed intracranial neoplasms, are usually benign and pharmacologically and surgically treatable; however, the critical location, mass effects and hormone hypersecretion sustain their significant morbidity. Approximately 35% of pituitary tumors show a less benign course since they are highly proliferative and invasive, poorly resectable, and likely recurring. The latest WHO classification of pituitary tumors includes pituitary transcription factor assessment to determine adenohypophysis cell lineages and accurate designation of adenomas, nevertheless little is known about molecular and cellular pathways which contribute to pituitary tumorigenesis. In malignant tumors the identification of cancer stem cells radically changed the concepts of both tumorigenesis and pharmacological approaches. Cancer stem cells are defined as a subset of undifferentiated transformed cells from which the bulk of cancer cells populating a tumor mass is generated. These cells are able to self-renew, promoting tumor progression and recurrence of malignant tumors, also conferring cytotoxic drug resistance. On the other hand, the existence of stem cells within benign tumors is still debated. The presence of adult stem cells in human and murine pituitaries where they sustain the high plasticity of hormone-producing cells, allowed the hypothesis that putative tumor stem cells might exist in pituitary adenomas, reinforcing the concept that the cancer stem cell model could also be applied to pituitary tumorigenesis. In the last few years, the isolation and phenotypic characterization of putative pituitary adenoma stem-like cells was performed using a wide and heterogeneous variety of experimental models and techniques, although the role of these cells in adenoma initiation and progression is still not completely definite. The assessment of possible pituitary adenoma-initiating cell population would be of extreme relevance to better understand pituitary tumor biology and to identify novel potential diagnostic markers and pharmacological targets. In this review, we summarize the most updated studies focused on the definition of pituitary adenoma stem cell phenotype and functional features, highlighting the biological processes and intracellular pathways potentially involved in driving tumor growth, relapse, and therapy resistance