Byzantines Can Also Learn from History: Fall of Centered Clipping in Federated Learning

The increasing popularity of the federated learning (FL) framework due to its success in a wide range of collaborative learning tasks also induces certain security concerns. Among many vulnerabilities, the risk of Byzantine attacks is of particular concern, which refers to the possibility of malicious clients participating in the learning process. Hence, a crucial objective in FL is to neutralize the potential impact of Byzantine attacks and to ensure that the final model is trustable. It has been observed that the higher the variance among the clients’ models/updates, the more space there is for Byzantine attacks to be hidden. As a consequence, by utilizing momentum, and thus, reducing the variance, it is possible to weaken the strength of known Byzantine attacks. The centered clipping (CC) framework has further shown that the momentum term from the previous iteration, besides reducing the variance, can be used as a reference point to neutralize Byzantine attacks better. In this work, we first expose vulnerabilities of the CC framework, and introduce a novel attack strategy that can circumvent the defences of CC and other robust aggregators and reduce their test accuracy up to %33 on best-case scenarios in image classification tasks. Then, we propose a new robust and fast defence mechanism that is effective against the proposed and other existing Byzantine attacks.

Issue Information ‐ TOC

Issue Information ‐ TOC

Platelet count and risk of severe illness in hospitalised children with Influenza‐Like illness

Abstract Aim To examine the clinical significance of thrombocytosis (platelets > 500 × 10 9 /L) in admitted children with an influenza‐like illness. Methods We performed a database analysis consisting of patients evaluated at our medical centers with an influenza‐like illness between 2009 and 2013. We included paediatric patients and examined the association between platelet count, respiratory viral infections, and admission outcomes (hospital length of stay and admission to the paediatric intensive care unit) using regression models adjusting for multiple variables. Results A total of 5171 children were included in the study cohort (median age 0.8 years; interquartile range, 0.2–1.8; 58% male). Younger age, and not the type of viral infection, was associated with a high platelet count ( p  < 0.001). Elevated platelet count independently predicted admission outcomes ( p  ≤ 0.05). The presence of thrombocytosis was associated with an increased risk for a prolonged length of stay (odds ratio = 1.2; 95% Confidence interval = 1.1 to 1.4; p  = 0.003) and admission to the paediatric intensive care unit (odds ratio = 1.5; 95% Confidence interval = 1.1 to 2.0; p  = 0.002). Conclusion In children admitted with an influenza‐like illness, a high platelet count is an independent predictor of admission outcomes. Platelet count may be used to improve risk assessment and management decisions in these paediatric patients.

How entrepreneurial practices balance art and business: Insights into creative entrepreneurship in the European film industry

Relying on the literature on tensions and contradictions and the theory of practice, coupled with the literature on creative industries, this study uncovers how creative entrepreneurs balance the tension between art and business and respond to other challenges of creative entrepreneurship. The multiple case studies method is adopted by examining founders, cofounders and main employees of European film production companies. We reveal the perception of creative entrepreneurs towards the relationship between art and business. We explore different organizational and industry‐level challenges experienced by creative entrepreneurs and uncover the organizational practices they adopt to deal with the identified challenges. The research contributes to the phenomenon of creative entrepreneurship by introducing the practice perspective, to the literature on paradox and contradiction by exploring the micro‐foundations of tensions and paradox responses in high‐intensity situations and to practice‐based studies by investigating a domain‐specific practice theory and highlighting the agency of creative entrepreneurs in adapting practices necessary to deal with conflicting demands of creative entrepreneurship.

Activity‐guided purification and identification of endogenous bioactive peptides from barley sprouts ( Hordeum vulgare L.) with diabetes treatment potential

Summary Metabolic‐associated disorders such as blood pressure and type 2 diabetes (T2D) are some of modern society's widespread problems. While there are many beneficial treatments, the quest for “safe” alternatives using natural products ( e.g. , cereals) is of great promise, especially plant‐based peptides containing inherently endogenous bioactivities that can provide multiple health‐promoting effects. Here, we aimed to purify and identify potential endogenous peptides of barley sprouts through an activity‐guided process with a potential T2D therapeutical effect. Barley seeds were germinated, and sprouts were fractionated through ultrafiltration followed by RP‐HPLC. All peptide fractions were examined for various bioactivities (α‐glucosidase/DPP4 inhibition, antiglycation, antioxidant and metal chelation activities). LC‐Q‐TOF‐MS/MS was employed for sequence identification of the fraction with the highest activity level. The data demonstrated that fractions with molecular weights lower than 3 kDa were the only ones with antiglycation activities. The RP‐HPLC of the 3 kDa fraction resulted in 11 fractions, including 4 having significant IC 50 /EC 50 levels. F11 demonstrated the highest potential as T2D treatment, and the sequence identification provided the sequences SQQENELTSLIVESNNRFNNASNT. Natural bioactive peptides from easy to procure and cheap sources are promising molecules for therapeutic applications. Further in vivo and clinical testing are necessary to validate the current findings.

A model for predicting low progesterone levels on the day of embryo transfer in hormonally prepared vitrified‐warmed embryo transfer cycles: A secondary analysis of a prospective cohort study

Aim To develop a model that predicts low progesterone (P) levels on the day of embryo transfer (ET) based on patient and cycle characteristics, including serum estradiol (E 2 ) concentration after vaginal administration of micronized E 2 for endometrial preparation. Methods A prospective cohort of 193 patients scheduled for cryopreserved blastocyst transfer during an artificial endometrial preparation cycle, using micronized E 2 vaginally for first 4 days (4 mg/day), followed by oral administration (6 mg/day). Blood sampling for E 2 was performed prospectively on day‐5 of vaginal administration and analysis was performed retrospectively. On sixth day of P treatment (daily 300 mg of vaginal micronized P tablets), P levels were measured on ET day. Primary outcome measure was serum P levels after vaginal E 2 administration. Results Patients with low P levels on the day of ET (<7.8 ng/mL, 25th percentile) were heavier ( p  < 0.001) and exhibited lower day 5 serum E 2 levels ( p  < 0.001) compared with patients with adequate P levels. Multivariate linear regression analysis revealed that weight ( p  = 0.003) and day 5 E 2 levels ( p  < 0.001) were independently associated with the P levels. The sensitivity, specificity, and positive and negative predictive values (%) were 71.4, 55.6, 35.4, and 85.1 for weight ≥ 65 kg; 71.4, 61.8, 38.9, and 86.4 for day 5 E 2  ≤ 1615 pg/mL; 59.2, 83.3, 54.7, and 85.7 for the combination of these two variables; and 82.9, 62.5, 54.7, and 87.0 for the sequential inclusion of these variables, respectively. Conclusions Low day 5 E 2 levels following vaginal administration and high weight are independently associated with low P levels on the day of ET. Predictive performance is enhanced when these variables are considered sequentially or in combination.

Interface passivation for 31.25%-efficient perovskite/silicon tandem solar cells

Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more solar cells are stacked to improve the harvesting of solar energy. In this work, we devise a tandem device with a perovskite layer conformally coated on a silicon bottom cell featuring micrometric pyramids-the industry standard-to improve its photocurrent. Using an additive in the processing sequence, we regulate the perovskite crystallization process and alleviate recombination losses occurring at the perovskite top surface interfacing the electron-selective contact [buckminsterfullerene (C 60 )]. We demonstrate a device with an active area of 1.17 square centimeters, reaching a certified power conversion efficiency of 31.25%.

AB1467 POTENTIAL TRIGGERS OF FAMILIAL MEDITERRANEAN FEVER ATTACKS

AB1471 PROSPECTIVE FOLLOW-UP OF THE POST-THROMBOTIC SYNDROME DEVELOPMENT RISK IN PATIENTS WITH VASCULAR BEHÇET’S DISEASE