Work distribution functions for hysteresis loops in a single-spin system

We compute the distribution of the work done in driving a single Ising spin with a time-dependent magnetic field. Using Glauber dynamics we perform Monte-Carlo simulations to find the work distributions at different driving rates. We find that in general the work-distributions are broad with a significant probability for processes with negative dissipated work. The special cases of slow and fast driving rates are studied analytically. We verify that various work fluctuation theorems corresponding to equilibrium initial states are satisfied while a steady state version is not.Comment: 9 pages, 15 figure

How long does treated supracondylar humerus fracture in children take to recover elbow range?

Background: Our goal was to address requirement of physiotherapy after treatment of supracondylar humerus fractures in children and evaluate result of casting on elbow without injury using control group of distal forearm fractures.Methods: 57 cases of supracondylar fractures were included in this retrospective study and compared with group of 54 children with distal forearm fractures treated with long arm casting for 28 days. Passive elbow ROM was checked with goniometer on day of cast removal, 2 weeks later, and then every month until the elbow ROM returned to 95% ROM (ROM-95) of uninjured side. No physiotherapy was given.Results: Average time in cast for supracondylar fracture group was 31.8 days and distal forearm fracture group was 32.4 days. The elbow total flexion angle reached a plateau of 139 degrees at 1month after cast removal whereas forearm group required less than 2 weeks. Total rotation ROM required half the time to reach 139 degrees in forearm group. From the paired t test it took more time for pronation to recover than supination in supracondylar fractures. In supracondylar group there was positive correlation between casting period and recovery period of ROM-95 elbow extension (p=0.021) and days of casting (p=0.021) and ROM-95 flexion recovery period. There was no statistically significant impact between casting and recovery period in other directions and recovery of ROM-95 & F-ROM and the subclassification and type of treatment of individual fractures.Conclusions: Lessons learned: thorough assessment of elbow function post cast removal, lack of need of physiotherapy in management protocol and elbow stiffness is related to initial injury and associated treatment not merely immobilisation

Capacity of Asynchronous Random-Access Scheduling in Wireless Networks

Abstract—We study the throughput capacity of wireless networks which employ (asynchronous) random-access scheduling as opposed to deterministic scheduling. The central question we answer is: how should we set the channel-access probability for each link in the network so that the network operates close to its optimal throughput capacity? We design simple and distributed channel-access strategies for random-access networks which are provably competitive with respect to the optimal scheduling strategy, which is deterministic, centralized, and computationally infeasible. We show that the competitiveness of our strategies are nearly the best achievable via random-access scheduling, thus establishing fundamental limits on the performance of randomaccess. A notable outcome of our work is that random access compares well with deterministic scheduling when link transmission durations differ by small factors, and much worse otherwise. The distinguishing aspects of our work include modeling and rigorous analysis of asynchronous communication, asymmetry in link transmission durations, and hidden terminals under arbitrary link-conflict based wireless interference models. I

Printing in a Pandemic: 3D printing solutions for healthcare during COVID-19. A Protocol for a PRISMA systematic review

Introduction: The COVID-19 pandemic had an unprecedented global socioeconomic impact. Responses to pandemics include strategies to accumulate vast stockpiles of vital medical equipment. In such times of desperation, 3D-printing could be a life-saving alternative. / Methods: We undertook a PRISMA systematic review of 3D printing solutions in response to COVID-19 utilising the PICO methodology. The objectives were to identify the uses of 3D printing during the COVID-19 pandemic, determine the extent of preclinical testing, comparison to commercial alternatives, presence of regulatory approvals and replicability regarding the description of the printing parameters and the availability of the print file. / Results: Literature searches of MEDLINE (OVID interface)/ PubMed identified 601 studies. Of these, 10 studies fulfilled the inclusion and exclusion criteria. Reported uses of 3D printing included personal protective equipment (PPE), nasopharyngeal swabs and adjunctive anaesthetic equipment. Few studies undertook formal safety and efficacy testing before clinical use with only one study comparing to the commercial equivalent. Six articles made their model print files available for wider use. / Conclusion: We describe a protocol for a systematic review of 3D-printed healthcare solutions in response to COVID-19. This remains a viable method of producing vital healthcare equipment when supply chains are exhausted. We hope that this will serve as a summary of innovative 3D-printed solutions during the peak of the pandemic and also highlight concerns and omissions regarding safety and efficacy testing that should be addressed urgently in preparation for a subsequent resurgences and future pandemics

Robustness against parametric noise of non ideal holonomic gates

Holonomic gates for quantum computation are commonly considered to be robust against certain kinds of parametric noise, the very motivation of this robustness being the geometric character of the transformation achieved in the adiabatic limit. On the other hand, the effects of decoherence are expected to become more and more relevant when the adiabatic limit is approached. Starting from the system described by Florio et al. [Phys. Rev. A 73, 022327 (2006)], here we discuss the behavior of non ideal holonomic gates at finite operational time, i.e., far before the adiabatic limit is reached. We have considered several models of parametric noise and studied the robustness of finite time gates. The obtained results suggest that the finite time gates present some effects of cancellation of the perturbations introduced by the noise which mimic the geometrical cancellation effect of standard holonomic gates. Nevertheless, a careful analysis of the results leads to the conclusion that these effects are related to a dynamical instead of geometrical feature.Comment: 8 pages, 8 figures, several changes made, accepted for publication on Phys. Rev.

Observations on the ossification centres of Trichopodus trichopterus (Pall.)

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