Belief propagation algorithm for computing correlation functions in finite-temperature quantum many-body systems on loopy graphs

Belief propagation -- a powerful heuristic method to solve inference problems involving a large number of random variables -- was recently generalized to quantum theory. Like its classical counterpart, this algorithm is exact on trees when the appropriate independence conditions are met and is expected to provide reliable approximations when operated on loopy graphs. In this paper, we benchmark the performances of loopy quantum belief propagation (QBP) in the context of finite-tempereture quantum many-body physics. Our results indicate that QBP provides reliable estimates of the high-temperature correlation function when the typical loop size in the graph is large. As such, it is suitable e.g. for the study of quantum spin glasses on Bethe lattices and the decoding of sparse quantum error correction codes.Comment: 5 pages, 4 figure

The war in Ukraine: Why knowing the country of origin of tech components is vital

The war in Ukraine has highlighted the significance of knowing the Country of Origin (COO) of technology product components. A single Iranian drone was found to contain parts made by more than a dozen US and western companies, and digital products can contain hardware components, software elements, and embedded systems and data from a range of countries and computing environments. How can this conundrum best be addressed to support national security? How can the end-consumer be better informed about the origin of digital products he/she is buying? And what are the implications for sustainability and the recyclability of these products

Cybersecurity and Country of Origin: Towards a New Framework for Assessing Digital Product Domesticity

Recent events concerning the Kaspersky anti-virus software in the UK and the Android operating system in the US have highlighted the significance of the domesticity of digital products for national cybersecurity, and the importance of establishing the origin of digital products has been further brought into focus by the war in Ukraine and China’s military activities around Taiwan. Digital products can contain hardware components, software elements, embedded systems, and data, and determining the country of origin (COO) in these circumstances is problematic. The aim of this research, and its main contribution, is to provide an operational framework for the application of the COO concept to address this problem. Using an inductive research methodology based on semi-structured interviews and an online survey, a 19-parameter framework for assessing the COO of digital products is developed and then applied to the case example of a mobile phone import in Turkey. This article concludes that new processes and policies are urgently required to enhance the cyber and information security for digital products, aid domestic digital technology production, and support the transition to recyclable technologies. Such developments are of significance not only for western nations concerned with data and security issues, but also for developing world countries trying to develop their own domestic digital product manufacturing capabilities. This is also of relevance to the computer end-user, who would benefit from greater clarity on the origin of digital products ahead of a purchase decision

The impacts of ridesourcing services on the taxi market: Empirical evidence from England and Wales

Ridesourcing services have emerged as a major competitor and potential substitute for traditional taxi services. However, research investigating the effects of ridesourcing on the taxi market remains limited, with a focus on specific geographies. This empirical study aims to fill this research gap by examining the impacts of ridesourcing on the taxi market in England and Wales. Using biennial Taxi and Private Hire Vehicle (PHV) Statistics data from the Department for Transport spanning 2005 to 2019, we investigate the impacts of ridesourcing on the number of Hackney Carriages (HCs) and PHVs, as well as the employment patterns in the taxi sector. Our findings indicate a gradual decline in the number of HCs following the introduction of ridesourcing. In contrast, the number of PHVs, which are restricted to pre-bookings, gradually increased. However, we observed no statistically significant change in the number of taxi drivers on average. Notably, our analysis reveals heterogeneous effects across different areas, including rural, urban, and metropolitan districts. Furthermore, we explore the role of regulatory environments in the evolution of ridesourcing and traditional taxi services. Our study highlights that regulation change allowing PHVs to operate across borders may lead to a dramatic increase in the number of PHVs and taxi drivers in specific local authorities. Our research has important implications for policymakers and transportation authorities, particularly in terms of maintaining a competitive taxi market. Furthermore, our findings can inform authorities when planning environmentally sustainable mobility services through the implementation of appropriate regulatory frameworks

The effects of ridesourcing services on vehicle ownership: The case of Great Britain

Understanding the impacts of ridesourcing on various transport externalities is an active research area. However, research on relatively long-term impacts such as vehicle ownership is limited and mostly focused on certain geographies. This is the first study that empirically examines the impacts of ridesourcing on vehicle ownership in Great Britain. We used vehicle licensing data for local authority districts from 2001 to 2019. We exploit the heterogeneity in entry dates of ridesourcing and employ the difference-in-differences method. We found that the impacts of the ridesourcing on vehicle numbers are heterogeneous across Great Britain. While the changes in vehicle numbers attributable to ridesourcing availability are not statistically significant in metropolitan districts and urban areas, we find 2.2% and 1.1% reductions in London and rural areas respectively. Our results contribute to future research on the broader impacts of ridesourcing and can inform research and policy efforts in this area, notably regarding decarbonisation

The Mechanism of Regulated Release of Lasso/Teneurin-2

Teneurins are large cell-surface receptors involved in axon guidance. Teneurin-2 (also known as latrophilin-1-associated synaptic surface organizer (Lasso)) interacts across the synaptic cleft with presynaptic latrophilin-1, an adhesion G-protein-coupled receptor that participates in regulating neurotransmitter release. Lasso-latrophilin-1 interaction mediates synapse formation and calcium signaling, highlighting the important role of this trans-synaptic receptor pair. However, Lasso is thought to be proteolytically cleaved within its ectodomain and released into the medium, making it unclear whether it acts as a proper cell-surface receptor or a soluble protein. We demonstrate here that during its intracellular processing Lasso is constitutively cleaved at a furin site within its ectodomain. The cleaved fragment, which encompasses almost the entire ectodomain of Lasso, is potentially soluble; however, it remains anchored on the cell surface via its non-covalent interaction with the transmembrane fragment of Lasso. Lasso is also constitutively cleaved within the intracellular domain (ICD). Finally, Lasso can be further proteolytically cleaved within the transmembrane domain. The third cleavage is regulated and releases the entire ectodomain of Lasso into the medium. The released ectodomain of Lasso retains its functional properties and binds latrophilin-1 expressed on other cells; this binding stimulates intracellular Ca2+ signaling in the target cells. Thus, Lasso not only serves as a bona fide cell-surface receptor, but also as a partially released target-derived signaling factor

Threshold Implementations of all 3x3 and 4x4 S-boxes

Side-channel attacks have proven many hardware implementations of cryptographic algorithms to be vulnerable. A recently proposed masking method, based on secret sharing and multi-party computation methods, introduces a set of sufficient requirements for implementations to be provably resistant against first-order DPA with minimal assumptions on the hardware. The original paper doesn\u27t describe how to construct the Boolean functions that are to be used in the implementation. In this paper, we derive the functions for all invertible $3 \times 3$, $4 \times 4$ S-boxes and the $6 \times 4$ DES S-boxes. Our methods and observations can also be used to accelerate the search for sharings of larger (e.g. $8 \times 8$) S-boxes. Finally, we investigate the cost of such protection

Association between frontal sinus development and persistent metopic suture

Background: Frontal sinuses are 2 irregular cavities, placed between 2 lamina of frontal bone. Expansion continues during childhood and reaches full size after puberty. Persistent metopic suture is one of the factors that are related to abnormal frontal sinus development. In this study, we want to discuss about the coexistence of persistent metopic suture and abnormal frontal sinus development using radiological techniques.Materials and methods: In this retrospectively planned study, images of 631 patients were examined, 217 (34.4%) of them were men and 414 (65.6%) of them were women. Brain computed tomography and magnetic resonance images were retrieved from the electronic archive for analysis.Results: In this study, frontal sinus development is categorised as right side atrophy, left side atrophy, bilateral atrophy and bilaterally developed sinuses. The presence of metopic suture was accepted as persistent metopic suture. Frontal sinus atrophy was found in 22.7% and persistent metopic sutures were found in 9.7% of overall.Conclusions: In this study, no significant results were detected that were relatedto the frontal sinus agenesis or dismorphism associated with persistent metopicsuture. We conclude that, although publications propounding metopism thatleads to abnormal frontal sinus development are present in the literature, noreasonable explanation has been mentioned in these articles; and we believe thatthese findings are all incidental.

Quantification of Spatial Parameters in 3D Cellular Constructs Using Graph Theory

Multispectral three-dimensional (3D) imaging provides spatial information for biological structures that cannot be measured by traditional methods. This work presents a method of tracking 3D biological structures to quantify changes over time using graph theory. Cell-graphs were generated based on the pairwise distances, in 3D-Euclidean space, between nuclei during collagen I gel compaction. From these graphs quantitative features are extracted that measure both the global topography and the frequently occurring local structures of the “tissue constructs.” The feature trends can be controlled by manipulating compaction through cell density and are significant when compared to random graphs. This work presents a novel methodology to track a simple 3D biological event and quantitatively analyze the underlying structural change. Further application of this method will allow for the study of complex biological problems that require the quantification of temporal-spatial information in 3D and establish a new paradigm in understanding structure-function relationships