Taming a non-convex landscape with dynamical long-range order: memcomputing Ising benchmarks

Recent work on quantum annealing has emphasized the role of collective behavior in solving optimization problems. By enabling transitions of clusters of variables, such solvers are able to navigate their state space and locate solutions more efficiently despite having only local connections between elements. However, collective behavior is not exclusive to quantum annealers, and classical solvers that display collective dynamics should also possess an advantage in navigating a non-convex landscape. Here, we give evidence that a benchmark derived from quantum annealing studies is solvable in polynomial time using digital memcomputing machines, which utilize a collection of dynamical components with memory to represent the structure of the underlying optimization problem. To illustrate the role of memory and clarify the structure of these solvers we propose a simple model of these machines that demonstrates the emergence of long-range order. This model, when applied to finding the ground state of the Ising frustrated-loop benchmarks, undergoes a transient phase of avalanches which can span the entire lattice and demonstrates a connection between long-range behavior and their probability of success. These results establish the advantages of computational approaches based on collective dynamics of continuous dynamical systems

CT-based tumour response criteria compared after combined treatment for liver metastases of colorectal cancer

open6noPurpose: The aim of this analysis is to compare different tumour response criteria (TRC) after chemotherapy combined with bevacizumab in liver metastases from colorectal cancer (mCRC) to ascertain the best early prognostic indicator of response. Methods and Materials: 103 target liver metastases from 65 mCRC patients treated with chemoterapy plus bevacizumab were examined at the Istituto Oncologico Veneto IOV-IRCSS (March 2008-January 2013). All patients had baseline CT and at least one follow-up scan. Tumour response was retrospectively analyzed by two radiologists using RECIST1.1, modified Choi, and Chun morphologic criteria. Tumour response, classified as good (complete or partial response) or poor (stable or progressive disease), was compared with progression-free survival (PFS) at first follow-up (t1) and time of best response. Interobserver agreement and concordance between TRC were measured. Results: At t1, 32.31% showed a good response according to RECIST1.1 (median PFS 11.1), 84.62% according to Choi (median PFS 10.8). These percentages rose to 49.23% (median PFS 12.1) and 87.69% (median PFS 10.8), respectively, at the time of best response. According to Chun, 67.69% showed a good response at the time of best response (median PFS 10.8). The Choi criteria detected a higher proportion of good responders at t1, showing a better correlation with PFS; all methods correlated with PFS at the time of best response. Conclusion: The Choi criteria proved more consistent in the early detection of response in mCRC treated with chemotherapy plus bevacizumab, underscoring the importance of using these criteria in the early assessment of response to combined treatment.openopenVarotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, F.Varotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, Fabi

The Impact of Exogenous Shocks on Business Models and Business Relationships: An Empirical Analysis of the Italian Music Industry

Purpose: Scholars have been increasingly interested in understanding business models. However, little attention has been paid to how business models change in reaction to exogenous circumstances and how business relationships alter be-cause of business model changes. This paper investigates how the business model paradigm of the Italian music industry altered in response to two major exogenous influences that impacted the sector: the digital revolution and the COVID-19 pandemic. Design/methodology/approach: As the purpose of this study is to investigate phenomena in a real-world setting, qualitative research methodology has been selected as the most appropriate one. It was decided to conduct sixteen semi-structured interviews with professionals active in the Italian music business, selected through a combination of snowball and convenience sampling. Findings: The empirical findings indicate that the digital revolution and COVID-19 pushed Italian music companies to revise their business models by either reducing or adding the number of linkages to the existing ones. This was done in order for the companies to remain competitive in an environment that is constantly changing and to outcompete rivals. Originality/value: Few studies have evaluated how business relationships alter in response to the many business models emerging in the music industry due to external causes. This research is one of the first to examine music companies’ reactions to exogenous events such as crises or disruptive advances that affect the competitive landscap

Editorial: From Meaning of Working to Meaningful Lives: The Challenges of Expanding Decent Work

This Research Topic explores issues that are central to the continued relevance of organizational and vocational psychology, and equally central to the well-being of individuals and communities. The cohering theme of this publication revolves around the question of how people can establish meaningful lives and meaningful work experiences in light of the many challenges that are reducing access to decent work. Another essential contextual factor that is explored in this volume is the Decent Work Agenda (International Labour Organization, 2008), which represents an initiative by the International Labour Organization. In this book, we hope to enrich the Decent Work Agenda by infusing the knowledge and perspectives of psychology into contemporary discourses about work, and well-being. Another inspiration for this project emerged from the UNESCO Chair in Lifelong guidance and counseling, recently established in Poland in 2013 under the leadership of Jean Guichard, which has focused on advancing research and policy advocacy about decent work. This new era calls for an innovative perspective in constructing decent work and decent lives: the passage from the paradigm of motivation to the paradigm of meaning, where the sustainability of the decent life project is anchored to a meaningful construction. During this period when work is changing so rapidly, leaving people yearning for a sense of connection and meaning, it’s fundamental to create a framework for an explicitly psychological analysis of decent work

MemComputing Integer Linear Programming

Integer linear programming (ILP) encompasses a very important class of optimization problems that are of great interest to both academia and industry. Several algorithms are available that attempt to explore the solution space of this class efficiently, while requiring a reasonable compute time. However, although these algorithms have reached various degrees of success over the years, they still face considerable challenges when confronted with particularly hard problem instances, such as those of the MIPLIB 2010 library. In this work we propose a radically different non-algorithmic approach to ILP based on a novel physics-inspired computing paradigm: Memcomputing. This paradigm is based on digital (hence scalable) machines represented by appropriate electrical circuits with memory. These machines can be either built in hardware or, as we do here, their equations of motion can be efficiently simulated on our traditional computers. We first describe a new circuit architecture of memcomputing machines specifically designed to solve for the linear inequalities representing a general ILP problem. We call these self-organizing algebraic circuits, since they self-organize dynamically to satisfy the correct (algebraic) linear inequalities. We then show simulations of these machines using MATLAB running on a single core of a Xeon processor for several ILP benchmark problems taken from the MIPLIB 2010 library, and compare our results against a renowned commercial solver. We show that our approach is very efficient when dealing with these hard problems. In particular, we find within minutes feasible solutions for one of these hard problems (f2000 from MIPLIB 2010) whose feasibility, to the best of our knowledge, has remained unknown for the past eight years