Experimental measurement-device-independent quantum digital signatures

The development of quantum networks will be paramount towards practical and secure telecommunications. These networks will need to sign and distribute information between many parties with information-Theoretic security, requiring both quantum digital signatures (QDS) and quantum key distribution (QKD). Here, we introduce and experimentally realise a quantum network architecture, where the nodes are fully connected using a minimum amount of physical links. The central node of the network can act either as a totally untrusted relay, connecting the end users via the recently introduced measurement-device-independent (MDI)-QKD, or as a trusted recipient directly communicating with the end users via QKD. Using this network, we perform a proof-of-principle demonstration of QDS mediated by MDI-QKD. For that, we devised an efficient protocol to distil multiple signatures from the same block of data, thus reducing the statistical fluctuations in the sample and greatly enhancing the final QDS rate in the finite-size scenario

High-rate quantum cryptography in untrusted networks

We extend the field of continuous-variable quantum cryptography to a network formulation where two honest parties connect to an untrusted relay by insecure quantum links. To generate secret correlations, they transmit coherent states to the relay where a continuous-variable Bell detection is performed and the outcome broadcast. Even though the detection could be fully corrupted and the links subject to optimal coherent attacks, the honest parties can still extract a secret key, achieving high rates when the relay is proximal to one party, as typical in public networks with access points or proxy servers. Our theory is confirmed by an experiment generating key-rates which are orders of magnitude higher than those achievable with discrete-variable protocols. Thus, using the cheapest possible quantum resources, we experimentally show the possibility of high-rate quantum key distribution in network topologies where direct links are missing between end-users and intermediate relays cannot be trusted.Comment: Theory and Experiment. Main article (6 pages) plus Supplementary Information (additional 13 pages

The relationship between young people, social media use and alcohol use: A prospective cohort study

Background and aims Social media use is now a significant part of modern daily life. Little is known about how social media impacts young peoples’ drinking behaviours and drinking-related consequences. This cohort study aims to explore the prospective relationship between social media use and future drinking. Methods 1473 alcohol naïve young people, who at Wave 5 (aged 12–13 years) reported no lifetime alcohol use, were included (social media use, peer alcohol use, and covariates were also reported at Wave 5). At Wave 8 (aged 17–18 years), participants reported alcohol use outcomes, including age of drinking initiation, past month and past week risky consumption (>10 drinks/week), and problem drinking (alcohol-related troubles, injuries, and fights). Results After controlling for factors known to be associated with alcohol use in young people and applying a conservative significance level (α =.01), results revealed that children who engaged in almost daily social media use at ages 12–13 later reported a younger age of drinking onset (β = −0.56, 95 % CI = −0.74, −0.39, p <.001) and greater problem drinking (β = 0.48, 95 % CI = 0.13, 0.83, p =.008) at ages 17–18, compared to those who never used social media at ages 12–13. Early social media use was not associated with odds of subsequent past-month alcohol use or risky alcohol consumption. Conclusion Young peoples’ social media use was associated with future drinking behaviours, prompting the need for preventative measures to acknowledge the salient impacts of social media.Full Tex

Prevalence and correlates of cannabis use for medicinal reasons – An Australian cross-sectional study

Objective It is important to know the prevalence and source of medicinal cannabis use in the population because non-prescribed medicinal use of cannabis products places individuals at higher risk of harms. We estimated the prevalence and correlates of the use of cannabis for medicinal purposes in Australia, three years after Australians were given legal access. Design Cross-sectional. Setting The 2019 Australian National Drug Strategy Household Survey. Participants Participants were 22,015 Australians aged 14 or above. Outcome measure Self-reported cannabis use in the last 12 months for medicinal purposes only, both medicinal/recreational reasons, or recreationally only. Those who reported medicinal use were asked if it had been prescribed by a doctor. Prevalence estimates were weighted to the population and multinomial logistic regression examined the correlates. Results The prevalence of any medicinal cannabis use in the past year was 2.6%. Only 0.8% of the sample reported using cannabis solely for medicinal reasons, 95.9% of whom did not have a prescription. A self-reported diagnosis of cancer was associated with medicinal use only. Self-reported chronic pain was associated with both medicinal only and medicinal/recreational use. Medicinal cannabis use was associated with opioids use. Conclusions In 2019, the prevalence of cannabis use solely for medicinal reasons remains under 1%, was more common among people with specific medical conditions, but most individuals do not have a prescription. The prevalence of self-reported medicinal cannabis use in Australia is low and there is limited use of the legal pathway for medicinal cannabis.Full Tex

Association of dietary patterns and food groups intake with multimorbidity: A prospective cohort study

Background Although diet has been extensively studied in relation to individual chronic conditions, studies linking diet with multiple chronic conditions (multimorbidity) remained scarce. We aimed to undertake a comprehensive analysis evaluating associations of overall dietary patterns and specific food groups with long-term risk of multimorbidity. Methods The study included 348,290 participants from UK Biobank who completed eligible food frequency questionnaires (FFQ) and were not diagnosed with any of the 38 chronic or mental health conditions of interest at baseline (2006–2010). Dietary patterns were identified using exploratory factor analysis. Cox regression models were used to estimate corresponding hazard ratios (HRs) and 95% confidence intervals (CIs). Results The median follow-up was 8.01 years, and 50,837 (14.60%) participants developed multimorbidity. Among the three identified dietary patterns, the Western Pattern was associated with an increased risk of multimorbidity (HRQ5 vs Q1 = 1.06, 95% CI: 1.03–1.09), while inverse associations were observed for moderate adherence to the White Meat Pattern (HRQ3 vs Q1 = 0.97, 95% CI: 0.94–0.99) and highest adherence to the Prudent Pattern (HRQ5 vs Q1 = 0.92, 95% CI: 0.90–0.95). For specific food groups, more frequent intakes of processed meat and poultry were associated with higher risks of multimorbidity, whereas higher intake frequency of fish and more intakes of fruits and cereal were associated with decreased risks. Conclusion Dietary patterns and specific food groups are associated with the risk of multimorbidity. These findings suggest the importance of considering dietary interventions in the prevention and management of multimorbidity

A systematic review and meta-analysis of the relationship between youth drinking, self-posting of alcohol use and other social media engagement (2012–21)

Background and aim: Social networking sites (SNS) are interactive internet-based social platforms that facilitate information sharing. A growing body of literature on exposure to, and self-posting of, alcohol-related content on SNS has examined the relationship between SNS use and alcohol consumption in young people. This study aims to synthesise the literature exploring the relationship between exposure (i.e. viewing or listening of alcohol-related media) and self-posting (i.e. uploading images or text of alcohol content) of alcohol-related media on SNS on alcohol consumption. Methods: A pre-registered systematic review was conducted in June 2022 within PubMed, Scopus, PsycINFO and Web of Science. Original prospective and cross-sectional studies assessing youth and young adults (≤ 24 years of age) that measured exposure to alcohol-related media or posting of alcohol-related content on SNS and self-reported alcohol consumption outcomes were included. Meta-analyses were conducted on comparable methodologies. Results: Thirty studies were included (n = 19,386). Meta-analyses of cross-sectional studies showed both greater exposure (five studies; pooled β = 0.34, 95% confidence interval [CI] = 0.23, 0.44, i2 = 27.7%) and self-posting of alcohol-related content (six studies; pooled β = 0.57, 95%CI = 0.25,0.88, i2 = 97.8%) was associated with greater alcohol consumption. Meta-analyses of three prospective studies also identified that greater exposure predicted greater future alcohol consumption (three studies; pooled β = 0.13, 95%CI = 0.11,0.15, i2 = 0.0%). Narrative analyses of studies that could not be meta-analysed due to incompatible methodologies were also conducted. Most studies (all four prospective, one of two cross-sectional) identified positive associations between exposure to alcohol-related content and greater average consumption. Most studies (three of four prospective, four of six cross-sectional) reported a positive association between of alcohol-related self-posting and greater average alcohol consumption. Conclusions: Both exposure to, and self-posting of, alcohol-related content on social networking sites are positively associated with current average consumption, problem drinking, and drinking frequency.No Full Tex