Superconducting Nanowire Spiking Element for Neural Networks.

As the limits of traditional von Neumann computing come into view, the brain's ability to communicate vast quantities of information using low-power spikes has become an increasing source of inspiration for alternative architectures. Key to the success of these largescale neural networks is a power-efficient spiking element that is scalable and easily interfaced with traditional control electronics. In this work, we present a spiking element fabricated from superconducting nanowires that has pulse energies on the order of ∼10 aJ. We demonstrate that the device reproduces essential characteristics of biological neurons, such as a refractory period and a firing threshold. Through simulations using experimentally measured device parameters, we show how nanowire-based networks may be used for inference in image recognition and that the probabilistic nature of nanowire switching may be exploited for modeling biological processes and for applications that rely on stochasticity.

Focusing on fidelity: narrative review and recommendations for improving intervention fidelity within trials of health behaviour change interventions.

Background: Interventions to change behaviour have substantial potential to impact positively on individual and overall public health. Despite an increasing focus on health behaviour change intervention research, interventions do not always have the desired effect on outcomes, while others have diluted effects once implemented into real-life settings. There is little investment into understanding how or why such interventions work or do not work. Methodological inadequacies of trials of behavioural interventions have been previously suggested as a barrier to the quality and advancement of behavioural research, with intervention fidelity acknowledged as a key area for improvement. However, there is much ambiguity regarding the terminology and conceptualisation of intervention fidelity and a lack of practical guidance regarding how to address it sufficiently, particularly within trials of complex behavioural interventions. Objectives: This article outlines specific issues concerning intervention fidelity within trials of health behaviour change interventions and suggests practical considerations and specific recommendations for researchers, with examples from the literature presented. Conclusions: Recommendations pertain to (1) clarifying how fidelity is defined and conceptualised, (2) considering fidelity beyond intervention delivery, (3) considering strategies to both enhance and assess fidelity, (4) making use of existing frameworks and guidance, (5) considering the quality and comprehensiveness of fidelity assessment strategies, (6) considering the balance between fidelity and adaptation and (7) reporting the use of fidelity enhancement and assessment strategies and their results. Suggestions for future research to improve our understanding of, and ability to, address fidelity in behaviour change interventions are also provided.

Bridging the Gap Between Nanowires and Josephson Junctions: A Superconducting Device Based on Controlled Fluxon Transfer.

The basis for superconducting electronics can broadly be divided between two technologies: the Josephson junction and the superconducting nanowire. While the Josephson junction (JJ) remains the dominant technology due to its high speed and low power dissipation, recently proposed nanowire devices offer improvements such as gain, high fanout, and compatibility with CMOS circuits. Despite these benefits, nanowire-based electronics have largely been limited to binary operations, with devices switching between the superconducting state and a high-impedance resistive state dominated by uncontrolled hotspot dynamics. Unlike the JJ, they cannot increment an output through successive switching and their operation speeds are limited by their slow thermal-reset times. Thus, there is a need for an intermediate device with the interfacing capabilities of a nanowire but a faster, moderated response allowing for modulation of the output. We present a nanowire device based on controlled fluxon transport. We show that the device is capable of responding proportionally to the strength of its input, unlike other nanowire technologies. The device can be operated to produce a multilevel output with distinguishable states, the number of which can be tuned by circuit parameters. Agreement between experimental results and electrothermal circuit simulations demonstrates that the device is classical and may be readily engineered for applications including use as a multilevel memory.

Parental experiences and perceptions of infant complementary feeding: a qualitative evidence synthesis.

BACKGROUND: Interventions to prevent childhood obesity increasingly focus on infant feeding, but demonstrate inconsistent effects. A comprehensive qualitative evidence synthesis is essential to better understand feeding behaviours and inform intervention development. The aim of this study is to synthesize evidence on perceptions and experiences of infant feeding and complementary feeding recommendations. METHODS: Databases CINAHL, EMBASE, MEDLINE, PsycINFO, Academic Search Complete, SocIndex and Maternity and Infant Care were searched from inception to May 2017. Eligible studies examined parents' experiences of complementary feeding of children (<2 years). Data were synthesized using thematic synthesis. RESULTS: Twenty-five studies met inclusion criteria for review. Four key themes emerged. 'Guidelines and advice' highlights variety and inconsistencies between sources of complementary feeding information. 'Stage of weaning' describes infant feeding as a process involving different stages. 'Knowing and trying' outlines parents' engagement in feeding approaches based on instinct, prior experience or trial and error. 'Daily life' highlights problematic cost and time constraints for parents. DISCUSSION: Parents predominantly understand and want to engage in healthy feeding processes. Consideration of infant feeding as a process that changes over time is necessary to support parents. Provision of clear, consistent information and guidance from trusted sources on when, what and how to feed is also essential.

Recent advances in the molecular pathogenesis of Ewing's sarcoma.

Tumor development is a complex process resulting from interplay between mutations in oncogenes and tumor suppressors, host susceptibility factors, and cellular context. Great advances have been made by studying rare tumors with unique clinical, genetic, or molecular features. Ewing's sarcoma serves as an excellent paradigm for understanding tumorigenesis because it exhibits some very useful and important characteristics. For example, nearly all cases of Ewing's sarcoma contain the (11;22)(q24;q12) chromosomal translocation that encodes the EWS/FLI oncoprotein. Besides the t(11;22), however, many cases have otherwise simple karyotypes with no other demonstrable abnormalities. Furthermore, it seems that an underlying genetic susceptibility to Ewing's sarcoma, if it exists, must be rare. These two features suggest that EWS/FLI is the primary mutation that drives the development of this tumor. Finally, Ewing's sarcoma is an aggressive tumor that requires aggressive treatment. Thus, improved understanding of the pathogenesis of this tumor will not only be of academic interest, but may also lead to new therapeutic approaches for individuals afflicted with this disease. The purpose of this review is to highlight recent advances in understanding the molecular pathogenesis of Ewing's sarcoma, while considering the questions surrounding this disease that still remain and how this knowledge may be applied to developing new treatments for patients with this highly aggressive disease.

Plantar heel pain.

Plantar fasciitis is a common problem without known etiology. It responds well to multiple conservative modalities and no particular modality has been demonstrated to be clearly superior in the treatment of this condition. Over 90% of patients will be cured by non-operative treatment but this may require 6 to 12 months of treatment and encouragement by the physician. Extracorporeal shock wave therapy is a noninvasive treatment with a success rate comparable to surgery and a low complication rate. Surgery can be done endoscopically or open with similar long-term outcomes. Patients appear to recover from endoscopic treatment 4 to 5 weeks earlier than the open group. If there is a suggestion of FBLPN entrapment, then patients should have an open release.

Effect of nabumetone on hemostasis during arthroscopic knee surgery.

The known effects of commonly used nonsteroidal anti-inflammatory drugs (NSAIDs) on hemostatic parameters have led to concern over their use in the perioperative period. Nabumetone, unlike other NSAIDs, has little effect on collagen-induced platelet aggregation. To evaluate the effect of nabumetone 2000 mg daily on other hemostatic parameters (e.g., bleeding time, prothrombin time, and partial thromboplastin time) in the clinical setting, this double-masked study was conducted in patients with osteoarthritis undergoing arthroscopic knee surgery. After a 1-week placebo washout period, 58 patients were randomized to receive nabumetone and 53 were randomized to receive placebo. They were assessed before surgery (after 1 to 2 weeks of treatment) and again after surgery (after an additional 3 weeks of treatment). The study was designed to have 90% power to show equivalence in bleeding time to within 1.5 minutes, a difference assumed to be of no clinical importance. No meaningful differences were observed between the groups in any of the measured hemostatic parameters. Before surgery, the bleeding time increased by only 0.3 minutes with nabumetone and decreased by 0.2 minutes with placebo. The mean (+/- SD) difference between the groups in change from baseline was 0.5 +/- 0.3 minutes. After surgery, the changes were 0.1 minutes and 0.0 minutes, respectively, and the difference between groups was 0.2 +/- 0.3 minutes. These differences were neither statistically nor clinically significant, and maximum individual increases were similar in each group. Furthermore, there were no reports of abnormal bleeding in the operative knees. The results of this study show that nabumetone had little or no effect on hemostasis and suggest that this drug can be used safely in the perioperative period.

Fibular-Achilles tenodesis for paralytic ankle valgus.

Children with myelomeningocele often develop progressive valgus deformity of the ankle that may be concomitant with, or mistaken for, paralytic hindfoot valgus. The same deformity is encountered in children who sustain lower motor neuron deficits. It is imperative to obtain an anteroposterior weight-bearing radiograph of the ankles to differentiate and document the degree of ankle valgus. To address the ankle deformity, we employed the fibular-Achilles tenodesis described by Westin. We are reporting our experience with 18 patients (32 ankles) who underwent this procedure. We noted improvement in relative fibular length and reduced talar tilt in 26 ankles (81.2%). In addition, there was some improvement in the orientation of the hindfoot; rotational deformity was unaffected.