Specific health beliefs mediate sex differences in food choice

Objective: Although sex differences in dietary habits are well documented, the etiology of those differences is still a focus of research. The present study examines the role of specific health beliefs regarding healthy amounts of food for food choice and its relation to sex, more specifically, the assumption that sex differences in food choices are mediated by differentiating health beliefs. Method: 212 German participants (44.3% female) aged 18–70 answered an online self-report questionnaire on their dietary habits and health beliefs, based on the recommendations of the German Nutrition Society. Results: Most of the anticipated sex differences in food choice and some differences in health beliefs were found. The mediation hypothesis was partly supported, as the relationship between sex and fruit, vegetable, and fish consumption was mediated by the respective health beliefs. However, no mediation effects were found for meat, egg, cereal, and milk product consumption. Conclusion: The support for the mediation hypothesis aligns with previous findings and indicates that health beliefs might be an important pathway to fostering healthier food choices, especially for men. Nonetheless, sex differences in food choice were only partially mediated by sex differences in specific health beliefs, indicating that future studies might benefit from parallel mediation analyses to reveal the impact of other relevant factors influencing sex differences in food choice

Selbstorganisation von Cyclodextrinen und Polymeren zu Polyrotaxanen und deren biomedizinische Anwendungen

In dieser Arbeit ist die Synthese von Cyclodextrin-Polyrotaxanen (CD-PRx) und deren Anwendung in der Gentransfektion sowie als polymere Prodrug beschrieben. Im ersten Teil wurden kationische PRx auf Basis von Ionenen und einem Polyamidin hergestellt und das Komplexierungsvermögen der PRx mit DNA untersucht. Es wurden ca. 120 nm große kationische Polyplexe erhalten. Mittels in vitro Transfektionsstudien wurde gezeigt, dass die Transfektionseffizienzen der PRx vergleichbar mit dem kommerziell erhältlichen Polyethylenimin sind und ein Zusammenhang zwischen der Ladungsdichte des Polykations mit der Transfektionseffizienz besteht. Im nächsten Schritt wurden die kationischen Polyplexe zunächst mit anionischer CD-modifizierter Hyaluronsäure und final mit adamantyliertem Transferrin beschichtet. Diese oberflächenfunktionalisierten Partikel können via rezeptorvermittelter Endocytose verbessert in die Zelle aufgenommen werden. Im zweiten Teil wurde ein anionisches Hydroxypropyl-β-CD-Polyrotaxan auf Basis von biokompatiblem Poly(decamethylen phosphat) hergestellt. Dieses kann als slow release Formulierung für Hydroxypropyl-β-CD (HP-β-CD), einem Wirkstoff zur Solubilisierung des aggregierten Cholesterols in der Niemann-Pick (NPC) Krankheit, eingesetzt werden. Nach Bestimmung der Freisetzungskinetik des HP-β-CD wurde das therapeutische Potential des PRx an NPC-Fibroplasten evaluiert. Die zelluläre Aufnahme und der Abbaus des PRx konnte mit einem fluoreszenzmarkierten PRx nachgewiesen werden.This thesis was focused on the assembly of cyclodextrin-polyrotaxanes (CD-PRx) and their application in gene transfection and for drug delivery. In the first part, cationic PRx based on ionenes and an polyamidine were assembled and the polyplex formation of these PRxs with DNA was evaluated. The resulting 120 nm sized polyplexes showed transfection efficiencies being comparable to polyethyleneimine, a commercially available cationic transfection agent. Furthermore, a relation between the charge density and the transfection efficiency of polycations was established. In the next step, the cationic polyplexes were coated first with anionic CDmodified hyaluronic acid, and afterwards with adamantylated transferrin. This surface modification enables an enhanced uptake of the particles via receptor mediated endocytosis leading to higher transfection efficiencies. The second part of this thesis describes the assembly of an anionic PRx from hydroxypropyl-β-CD (HP-β-CD) and poly(decamethylene phosphate) as an biocompatible and degradable polymer backbone. This PRx serves as a slow release formulation for HP-β-CD, a therapeutically active compound for the treatment of the Niemann Pick disease type C (NPC). After the investigation of the release of HP-β-CD from the PRx, the therapeutic potential of the PRx was evaluated in NPC deficient fibroblast cells. The uptake into and the degradation of the PRx within the cells were followed by using a respective PRx labeled with a fluorescence dye

Evaluating self-reported retrospective average daily fruit, vegetable, and egg intake: Trustworthy-Sometimes!

Retrospective self-reports are commonly used to assess dietary intake. Yet, their use is criticized as it is unclear whether the underlying assumptions for valid self-reports are met: Individuals have to consider the behavior of all days in the retention interval and weigh the behavior of all days equally. This study examines whether these assumptions for retrospective self-reports are met and whether interindividual differences in self-report performance are relevant regarding these assumptions. Ninety-two participants aged 18–61 years participated in seven sequential 24-h recalls and one retrospective 7-day recall concerning their intake of fruit, vegetables, and eggs. A multiple linear regression approach was used to examine the relation between the daily reported dietary intake and the 7-day recall. In the overall sample, the requirements for retrospective self-reports were not tenable. Distinguishing good and poor self-reporters based on a rational criterion showed that the requirements can be taken as given for good self-reporters, whereas poor self-reporters base their retrospective self-reports mostly on recency effects. The underlying requirements for retrospective self-reports appear to be met in two thirds of the sample, supporting the use of retrospective self-reports to capture dietary behavior. Future research should investigate characteristics separating good from poor self-reporters

Towards Detecting Compromised Accounts on Social Networks

Compromising social network accounts has become a profitable course of action for cybercriminals. By hijacking control of a popular media or business account, attackers can distribute their malicious messages or disseminate fake information to a large user base. The impacts of these incidents range from a tarnished reputation to multi-billion dollar monetary losses on financial markets. In our previous work, we demonstrated how we can detect large-scale compromises (i.e., so-called campaigns) of regular online social network users. In this work, we show how we can use similar techniques to identify compromises of individual high-profile accounts. High-profile accounts frequently have one characteristic that makes this detection reliable -- they show consistent behavior over time. We show that our system, were it deployed, would have been able to detect and prevent three real-world attacks against popular companies and news agencies. Furthermore, our system, in contrast to popular media, would not have fallen for a staged compromise instigated by a US restaurant chain for publicity reasons

ReCon: Revealing and Controlling PII Leaks in Mobile Network Traffic

It is well known that apps running on mobile devices extensively track and leak users' personally identifiable information (PII); however, these users have little visibility into PII leaked through the network traffic generated by their devices, and have poor control over how, when and where that traffic is sent and handled by third parties. In this paper, we present the design, implementation, and evaluation of ReCon: a cross-platform system that reveals PII leaks and gives users control over them without requiring any special privileges or custom OSes. ReCon leverages machine learning to reveal potential PII leaks by inspecting network traffic, and provides a visualization tool to empower users with the ability to control these leaks via blocking or substitution of PII. We evaluate ReCon's effectiveness with measurements from controlled experiments using leaks from the 100 most popular iOS, Android, and Windows Phone apps, and via an IRB-approved user study with 92 participants. We show that ReCon is accurate, efficient, and identifies a wider range of PII than previous approaches.Comment: Please use MobiSys version when referencing this work: http://dl.acm.org/citation.cfm?id=2906392. 18 pages, recon.meddle.mob

Is One Epoch All You Need For Multi-Fidelity Hyperparameter Optimization?

Hyperparameter optimization (HPO) is crucial for fine-tuning machine learning models but can be computationally expensive. To reduce costs, Multi-fidelity HPO (MF-HPO) leverages intermediate accuracy levels in the learning process and discards low-performing models early on. We compared various representative MF-HPO methods against a simple baseline on classical benchmark data. The baseline involved discarding all models except the Top-K after training for only one epoch, followed by further training to select the best model. Surprisingly, this baseline achieved similar results to its counterparts, while requiring an order of magnitude less computation. Upon analyzing the learning curves of the benchmark data, we observed a few dominant learning curves, which explained the success of our baseline. This suggests that researchers should (1) always use the suggested baseline in benchmarks and (2) broaden the diversity of MF-HPO benchmarks to include more complex cases.Comment: 5 pages, with extended appendice