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Context: Speedball is an increasingly popular racquet sport played in more than 25 countries. Our objective was to describe injury incidence and patterns among Egyptian national-level speedball athletes. Design: Descriptive epidemiological. Methods: We conducted a survey of athletes who were registered with the Egyptian Speedball Federation during the 2018–2019 professional season. The survey inquired about injury types and athlete exposures (AEs). The response rate was 63% (100/160 athletes). Respondent ages ranged from 18 to 41 years. We analyzed demographic characteristics; number, location, and mechanism of injuries; treatment; and speedball participation time lost because of injury. Results: Of 100 respondents, 65 reported having sustained at least one injury during the season for a total of 90 injuries and a rate of 4.7 injuries per 1000 AEs (95% confidence interval, 3.7 to 5.7). More injuries occurred during practice (77%) than during competition (23%). Thirty percent of respondents reported having missed a competition because of injury. The most frequent anatomic locations of injury were the shoulder (50%; 2.4/1000 AEs), elbow (14%; 0.68/1000 AEs), and low back (9%; 0.4/1000 AEs). The most frequently cited causes of injury were increased intensity of training (40%) and lack of warming up (18%). Seventy-seven percent of injured respondents underwent treatment by a health care professional, and 9% of these respondents underwent surgery. Conclusion: The shoulder was the most common anatomic location for injuries in speedball athletes. Our results suggest that attention should be directed toward sport-specific injury prevention and intervention strategies because speedball is a fast-growing sport in several countries.

The transfer of information between two physical locations is an essential component of both classical and quantum computing. In quantum computing the transfer of information must be coherent to preserve quantum states and hence the quantum information. We establish a simple protocol for transferring one- and two-electron encoded logical qubits in quantum dot arrays. The theoretical energetic cost of this protocol is calculated - in particular, the cost of freezing and unfreezing tunnelling between quantum dots. Our results are compared with the energetic cost of shuttling qubits in quantum dot arrays and transferring classical information using classical information buses. Only our protocol can manage constant dissipation for any chain length. This protocol could reduce the cooling requirements and constraints on scalable architectures for quantum dot quantum computers., Comment: 10 pages, 6 figures

The last years have seen a rapid development of applications of quantum computation to quantum field theory. The first algorithms for quantum simulation of scattering have been proposed in the context of scalar and fermionic theories, requiring thousands of logical qubits. These algorithms are not suitable to simulate scattering of incoming bound states, as the initial state preparation relies typically on adiabatically transforming wavepackets of the free theory into wavepackets of the interacting theory. In this paper we present a strategy to excite wavepackets of the interacting theory directly from the vacuum of the interacting theory, allowing for preparation of states of composite particles. This is the first step towards quantum simulation of scattering of bound states. The approach is based on the Haag-Ruelle scattering theory, which provides a way to construct creation and annihilation operators of a theory in a full, nonperturbative framework. We provide a quantum algorithm requiring a number of ancillary qubits that is logarithmic in the size of the wavepackets, and with a success probability depending on the state being prepared. The gate complexity for a single iteration of the circuit is equivalent to that of a time evolution for a fixed time., Comment: 12 pages, 1 figure. Key words: quantum simulation, lattice field theory, scattering, bound states

Misinformation and movements against vaccines put public health at risk. This study investigated vaccine awareness and opinions on the anti-vaccination movement among students at three faculties of Eastern Mediterranean University. Data were collected by questionnaire. Exposure to anti-vaccination propaganda increased proportionally with the size of the cities where participants were born. In total, 88.6% of the participants declared that they planned to vaccinate their children, while those who did not cited various reasons including the belief that vaccines do not work, that vaccines are harmful, and that it is better to be infected naturally. 60.6% of participants reported that they would get vaccinated against SARS-CoV-2 if there was an effective vaccine. Meanwhile, 24.5% of participants were not sure whether would get vaccinated even if it were possible, 11.4% of participants stated that they would not vaccinate their children for a variety of reasons. These results are important, especially in the context of a pandemic, because students will become leaders in education, business, and media, and thus shape the thoughts and opinions of future generations. The anti-vaccination movement is building momentum, and is especially influential in big cities; therefore, it is vital to change our approach to informing students about vaccination.

The initiation of coronary stents is a vast landmark in the practice of interventional cardiology. The vascular injury sustained during the percutaneous coronary intervention (PCI) leads to a complicated inflammatory and repairing process. Therefore, stent restenosis arises. Diabetes mellitus is the highest-risk clinical predictor of ISR. Genetics has an important role in the development of ISR. There is a suggested association between the appearance of stent restenosis and certain genetic polymorphisms. Examples of these single nucleotide polymorphisms are endothelial nitric oxide synthase gene (eNOS), the angiotensin converting enzyme gene (ACE), the angiotensin II type 1 receptor gene (AT1R), TGF-β, and VEGF. CYP2C19 variants can help change the medical strategy to a more individualized therapeutic regimen either by altering the therapeutic dose depending on the genotype or using an alternative drug that does not worsen the patient’s case. However, eNOS polymorphism produces gene expression alteration leading to ISR following stent placement. In addition, the deletion-allele of the ACE genotype increases the risk of ISR; however, the I allele decreases the risk. Moreover, the D/I polymorphism is not an independent factor of ISR in patients administering ACE inhibitors or angiotensin receptor antagonists. Furthermore, studies on large sample sizes are required to decrease the harmful adverse effects of stent restenosis by detecting these allele gene polymorphisms.

Giovannetti, Lloyd, and Maccone [Phys. Rev. Lett. 100, 160501] proposed a quantum random access memory (QRAM) architecture to retrieve arbitrary superpositions of $N$ (quantum) memory cells via $O(\log(N))$ quantum switches and $O(\log(N))$ address qubits. Towards physical QRAM implementations, Chen et al. [PRX Quantum 2, 030319] recently showed that QRAM maps natively onto optically connected quantum networks with $O(\log(N))$ overhead and built-in error detection. However, modeling QRAM on large networks has been stymied by exponentially rising classical compute requirements. Here, we address this bottleneck by: (i) introducing a resource-efficient method for simulating large-scale noisy entanglement, allowing us to evaluate hundreds and even thousands of qubits under various noise channels; and (ii) analyzing Chen et al.'s network-based QRAM as an application at the scale of quantum data centers or near-term quantum internet; and (iii) introducing a modified network-based QRAM architecture to improve quantum fidelity and access rate. We conclude that network-based QRAM could be built with existing or near-term technologies leveraging photonic integrated circuits and atomic or atom-like quantum memories., Comment: Keywords: Quantum RAM, Distributed Quantum Computation, Photonic Quantum Networks. Comments are welcome

We propose, and realise experimentally, Toffoli and Half-Adder circuits suitable for classical computation, using radiofrequency-controlled $^{171}\text{Yb}^+$ ions in a macroscopic linear Paul-trap as qubits. We analyse comprehensively the energy required to operate the logic gates, both theoretically and experimentally. We identify bottlenecks and possible improvements in future platforms for energetically-efficient computation, e.g., trap chips with integrated antennas and cavity QED. Based on our analysis, a novel planar ion trap is expected to be $10^5$ times more efficient. Our experimentally verified energetic model fills a gap in the literature of the energetics of quantum information, and outlines the path for its detailed study, as well as its potential applications to classical computing.

Some of the biggest achievements of the modern era of particle physics, such as the discovery of the Higgs boson, have been made possible by the tremendous effort in building and operating large-scale experiments like the Large Hadron Collider or the Tevatron. In these facilities, the ultimate theory to describe matter at the most fundamental level is constantly probed and verified. These experiments often produce large amounts of data that require storing, processing, and analysis techniques that often push the limits of traditional information processing schemes. Thus, the High-Energy Physics (HEP) field has benefited from advancements in information processing and the development of algorithms and tools for large datasets. More recently, quantum computing applications have been investigated in an effort to understand how the community can benefit from the advantages of quantum information science. In this manuscript, we provide an overview of the state-of-the-art applications of quantum computing to data analysis in HEP, discuss the challenges and opportunities in integrating these novel analysis techniques into a day-to-day analysis workflow, and whether there is potential for a quantum advantage., Comment: 23 pages, initially submitted to Snowmass 2021

We introduce a novel quadratic unconstrained binary optimization (QUBO) formulation for a classical problem in electrical engineering -- the optimal reconfiguration of distribution grids. For a given graph representing the grid infrastructure and known nodal loads, the problem consists in finding the spanning tree that minimizes the total link ohmic losses. A set of constraints is initially defined to impose topologically valid solutions. These constraints are then converted to a QUBO model as penalty terms. The electrical losses terms are finally added to the model as the objective function to minimize. In order to maximize the performance of solution searching with classical solvers, with hybrid quantum-classical solvers and with quantum annealers, our QUBO formulation has the goal of being very efficient in terms of variables usage. A standard 33-node test network is used as an illustrative example of our general formulation. Model metrics for this example are presented and discussed. Finally, the optimal solution for this example was obtained and validated through comparison with the optimal solution from an independent method., Comment: 21 pages, 9 figures. v2: Added new sections on model scaling and validation. Minor editorial changes

Background: Methotrexate (MTX) as an antineoplastic agent inhibits dihydrofolate reductase. The frequency of high dose methotrexate (HDMTX) associated toxicity is variable. In this study we investigate the frequency of myelosuppression following 5 and 9 days of HDMTX infusion and MTX delayed elimination in subsequent MTX cycles in children with Acute lymphoblastic Leukemia (ALL). Methods: This study included 28 children diagnosed with ALLduring the period between May2014to April 2016. Complete blood counts were measured before and after 5 and 9 days of HDMTX infusion and MTX levels at 42hour in 28 children with ALL. The HD-MTX dose is 5 gm/m2 during 102 infusion of HD MTX at consolidation phase of ALL therapy. The MTX levels at 42 h in patients with and without toxicity were compared to evaluate the correlation between MTX levels and myelotoxicity. Results: MTX infusion induced significant reduction in levels of TLC, ANC, RBCs, Hb and significant elevation of PLT count after 5 days of MTX administration. Additionally, after 9 days of MTX infusion, there is significant decrease inTLC, ANC, and RBCs levels. However, no significant difference in the PLT count and Hb level occurred. There is gradual decrease in myelotoxicity after 5 days and increase after 9 days of MTX administration with regard to MTX cycles. There is no statistical difference in MTX level at 42 h between patients with and without myelotoxicity after 5 and 9 days of MTX infusion. MTX delayed elimination observed in MTX cycles 1, 2, 3 and 4 was 42.8% (n=12), 42.8% (n=12), 57.1% (n=16) and 72% (n=13) respectively. Conclusion: Myelotoxicity was decreased after 5 days of MTX administration and increased after 9 days with regard to MTX cycles. There is no correlation between MTX plasma concentration after 42 h and hematologic toxicity. Therefore, we cannot depend on MTX levels at 42 h to anticipate and predict hematologic toxicity. Keywords: HDMTX, ALL, myelosupression, blood count

The scale-free property emerges in various real-world networks and is an essential property which characterizes the dynamics or features of such networks. In this work we investigate the effect of this scale-free property on a quantum information processing task of finding a marked node in the network, known as the quantum spatial search. We analyze the quantum spatial search algorithm using continuous-time quantum walk on the Bollob��s network, and evaluate the time $T$ to localize the quantum walker on the marked node starting from an unbiased initial state. Our main finding is that $T$ is determined by the global structure around the marked node, while some local information of the marked node such as degree does not identify $T$. We discuss this by examining the correlation between $T$ and some centrality measures of the network, and show that the closeness centrality of the marked node is highly correlated with $T$. We also characterize the distribution of $T$ by marking different nodes in the network, which displays a multi-mode lognormal distribution. Especially on the Bollob��s network, $T$ is magnitude of orders shorter depending whether the marked node is adjacent to the largest degree hub node or not. However, as $T$ depends on the property of the marked node, one requires some amount of prior knowledge about such property of the marked node in order to identify the optimal time to measure the quantum walker and achieve fast search. These results indicate that the existence of the hub node in the scale-free network is playing a crucial role on the quantum spatial search., 10 pages, 6 figures

We study the dynamics of a spin-1/2 particle interacting with a multi-spin environment, modelling the corresponding open system dynamics through a collision-based model. The environmental particles are prepared in individual thermal states, and we investigate the effects of a distribution of temperatures across the spin environment on the evolution of the system, particularly how thermalisation in the long-time limit is affected. %We also address the conditions under which the system reaches a stationary state, with particular attention to whether homogenization to the average environmental state occurs. We study the phenomenology of the heat exchange between system and environment and consider the information-to-energy conversion process, induced by the system-environment interaction and embodied by the Landauer principle. Furthermore, by considering an interacting-particles environment, we tune the dynamics of the system from an explicit Markovian evolution up to a strongly non-Markovian one, investigating the connections between non-Markovianity, the establishment of system-environment correlations, and the breakdown of the validity of Landauer principle., Comment: 14 pages, 6 figures. Published version

We propose a quantum thermal machine composed of two nanomechanical resonators (NMR) (two membranes suspended over a trench in a substrate), placed a few $\mu$m from each other. The quantum thermodynamical cycle is powered by the Casimir interaction between the resonators and the working fluid is the polariton resulting from the mixture of the flexural (out-of-plane) vibrations. With the help of piezoelectric cells, we select and sweep the polariton frequency cyclically. We calculate the performance of the proposed quantum thermal machines and show that high efficiencies are achieved thanks to (i) the strong coupling between the resonators and (ii) the large difference between the membrane stiffnesses. Our findings can be of particular importance for applications in nanomechanical technologies where a sensitive control of temperature is needed., Comment: Quantum thermal machines, Casimir effect, mechanical resonators, finite-time thermodynamics

There is great interest in designing photonic devices capable of disorder-resistant transport and information processing. In this work we propose to exploit 3D integrated photonic circuits in order to realize 2D discrete-time quantum walks in a background synthetic gauge field. The gauge fields are generated by introducing the appropriate phase shifts between waveguides. Polarization-independent phase shifts lead to an Abelian or magnetic field, a case we describe in detail. We find that, in the disordered case, the magnetic field enhances transport due to the presence of topologically protected chiral edge states which do not localize. Polarization-dependent phase shifts lead to effective non-Abelian gauge fields, which could be adopted to realize Rashba-like quantum walks with spin-orbit coupling. Our work introduces a flexible platform for the experimental study of multi-particle quantum walks in the presence of synthetic gauge fields, which paves the way towards topologically robust transport of many-body states of photons., Comment: This version contains results for the case of two-particle quantum walks

We propose a protocol for countering the effects of dephasing in quantum state transfer over a noisy spin channel weakly coupled to the sender and receiver qubits. Our protocol, based on performing regular global measurements on the channel, significantly suppresses the nocuous environmental effects and offers much higher fidelities than the traditional no-measurement approach. Our proposal can also operate as a robust two-qubit entangling gate over distant spins. Our scheme counters any source of dephasing, including those for which the well established dynamical decoupling approach fails. Our protocol is probabilistic, given the intrinsic randomness in quantum measurements, but its success probability can be maximized by adequately tuning the rate of the measurements., Comment: 8 pages, 9 figures

The XX model with uniform couplings represents the most natural choice for quantum state transfer through spin chains. Given that it has long been established that single-qubit states cannot be transferred with perfect fidelity in this model, the notion of pretty good state transfer has been recently introduced as a relaxation of the constraints on fidelity. In this paper, we study the transfer of multi-qubit entangled and unentangled states through unmodulated spin chains, and we prove that it is possible to have pretty good state transfer of any multi-particle state. This significantly generalizes the previous results on single-qubit state transfer, and opens way to using uniformly coupled spin chains as quantum channels for the transfer of arbitrary states of any dimension. Our results could be tested with current technology., Version published in New Journal of Physics

Quantum state engineering and quantum computation rely on information erasure procedures that, up to some fidelity, prepare a quantum object in a pure state. Such processes occur within Landauer's framework if they rely on an interaction between the object and a thermal reservoir. Landauer's principle dictates that this must dissipate a minimum quantity of heat, proportional to the entropy reduction that is incurred by the object, to the thermal reservoir. However, this lower bound is only reachable for some specific physical situations, and it is not necessarily achievable for any given reservoir. The main task of our work can be stated as the minimisation of heat dissipation given probabilistic information erasure, i.e., minimising the amount of energy transferred to the thermal reservoir as heat if we require that the probability of preparing the object in a specific pure state $|\varphi_1\rangle$ be no smaller than $p_{\varphi_1}^{\max}-\delta$. Here $p_{\varphi_1}^{\max}$ is the maximum probability of information erasure that is permissible by the physical context, and $\delta\geqslant 0$ the error. To determine the achievable minimal heat dissipation of quantum information erasure within a given physical context, we explicitly optimise over all possible unitary operators that act on the composite system of object and reservoir. Specifically, we characterise the equivalence class of such optimal unitary operators, using tools from majorisation theory, when we are restricted to finite-dimensional Hilbert spaces. Furthermore, we discuss how pure state preparation processes could be achieved with a smaller heat cost than Landauer's limit, by operating outside of Landauer's framework.

Recent years have enjoyed an overwhelming interest in quantum thermodynamics, a field of research aimed at understanding thermodynamic tasks performed in the quantum regime. Further progress, however, seems to be obstructed by the lack of experimental implementations of thermal machines in which quantum effects play a decisive role. In this work, we introduce a blueprint of quantum field machines, which—once experimentally realized—would fill this gap. Even though the concept of the QFM presented here is very general and can be implemented in any many-body quantum system that can be described by a quantum field theory. We provide here a detailed proposal of how to realize a quantum machine in one-dimensional ultracold atomic gases, which consists of a set of modular operations giving rise to a piston. These can then be coupled sequentially to thermal baths, with the innovation that a quantum field takes up the role of the working fluid. In particular, we propose models for compression on the system to use it as a piston, and coupling to a bath that gives rise to a valve controlling heat flow. These models are derived within Bogoliubov theory, which allows us to study the operational primitives numerically in an efficient way. By composing the numerically modeled operational primitives we design complete quantum thermodynamic cycles that are shown to enable cooling and hence giving rise to a quantum field refrigerator. The active cooling achieved in this way can operate in regimes where existing cooling methods become ineffective. We describe the consequences of operating the machine at the quantum level and give an outlook of how this work serves as a road map to explore open questions in quantum information, quantum thermodynamic, and the study of non-Markovian quantum dynamics.