Replication study: a cross-country field observation study of real world PIN usage at ATMs and in various electronic payment scenarios:towards understanding why people do, or do not, shield PIN entry

In this paper, we describe the study we carried out to replicate and extend the field observation study of real world ATM use carried out by De Luca et al., published at the SOUPS conference in 2010. Replicating De Luca et al.'s study, we observed PIN shielding rates at ATMs in Germany. We then extended their research by conducting a similar field observation study in Sweden and the United Kingdom. Moreover, in addition to observing ATM users (withdrawing), we also observed electronic payment scenarios requiring PIN entry. Altogether, we gathered data related to 930 observations. Similar to De Luca et al., we conducted follow-up interviews, the better to interpret our findings. We were able to confirm De Luca et al.'s findings with respect to low PIN shielding incidence during ATM cash withdrawals, with no significant differences between shielding rates across the three countries. PIN shielding incidence during electronic payment scenarios was significantly lower than incidence during ATM withdrawal scenarios in both the United Kingdom and Sweden. Shielding levels in Germany were similar during both withdrawal and payment scenarios. We conclude the paper by suggesting a number of explanations for the differences in shielding that our study revealed

Unstructured Randomness, Small Gaps and Localization

We study the Hamiltonian associated with the quantum adiabatic algorithm with a random cost function. Because the cost function lacks structure we can prove results about the ground state. We find the ground state energy as the number of bits goes to infinity, show that the minimum gap goes to zero exponentially quickly, and we see a localization transition. We prove that there are no levels approaching the ground state near the end of the evolution. We do not know which features of this model are shared by a quantum adiabatic algorithm applied to random instances of satisfiability since despite being random they do have bit structure

ZETA - Zero-Trust Authentication: Relying on Innate Human Ability, not Technology

Reliable authentication requires the devices and channels involved in the process to be trustworthy; otherwise authentication secrets can easily be compromised. Given the unceasing efforts of attackers worldwide such trustworthiness is increasingly not a given. A variety of technical solutions, such as utilising multiple devices/channels and verification protocols, has the potential to mitigate the threat of untrusted communications to a certain extent. Yet such technical solutions make two assumptions: (1) users have access to multiple devices and (2) attackers will not resort to hacking the human, using social engineering techniques. In this paper, we propose and explore the potential of using human-based computation instead of solely technical solutions to mitigate the threat of untrusted devices and channels. ZeTA (Zero Trust Authentication on untrusted channels) has the potential to allow people to authenticate despite compromised channels or communications and easily observed usage. Our contributions are threefold: (1) We propose the ZeTA protocol with a formal definition and security analysis that utilises semantics and human-based computation to ameliorate the problem of untrusted devices and channels. (2) We outline a security analysis to assess the envisaged performance of the proposed authentication protocol. (3) We report on a usability study that explores the viability of relying on human computation in this context

Zielgruppengerechte Bibliotheksangebote für Schülerinnen und Schüler in der Stadtbibliothek Heilbronn

In Öffentlichen Bibliotheken sind Nutzerbefragungen ein wichtiges Instrument zur Eva-luation des bestehenden Angebots. Neue, spezifische Erkenntnisse über die befragte Zielgruppe können gewonnen werden. Zu diesem Zweck sowie zur Weiterentwicklung ihres schülerspezifischen Angebots führte die Stadtbibliothek Heilbronn im Sommer 2005 eine dreiwöchige Benutzerumfrage mittels standardisiertem Fragebogen bei SchülerInnen im Alter von 13 bis 19 Jahren durch. Anlass war der Ausbau des Ange-bots an Lernhilfen sowie die verstärkte Kooperation zwischen Schule und Bibliothek. Diese Arbeit erläutert mit Hilfe von PISA und Shell Jugendstudie den aktuellen Stand der Bildungssituation in Deutschland. Außerdem bewertet sie die Relevanz von digita-len Diensten für SchülerInnen. Beispiele aus der Praxis im In- und Ausland liefern wertvolle Anregungen und Handlungsimpulse für die Zusammenarbeit zwischen Schu-le und Bibliothek. Nach den methodischen Vorüberlegungen wird die Planung sowie die Durchführung der Umfrage dargestellt. Die Resultate der Auswertung zeigen mögli-che Konsequenzen für eine zielgruppenspezifische Bibliotheksarbeit für SchülerInnen und Jugendliche auf

Accuracy of a magnetic resonance imaging‐based 3D printed stereotactic brain biopsy device in dogs

Background: Brain biopsy of intracranial lesions is often necessary to determine specific therapy. The cost of the currently used stereotactic rigid frame and optical tracking systems for brain biopsy in dogs is often prohibitive or accuracy is not sufficient for all types of lesion. Objectives: To evaluate the application accuracy of an inexpensive magnetic resonance imaging‐based personalized, 3D printed brain biopsy device. Animals: Twenty‐two dog heads from cadavers were separated into 2 groups according to body weight (20 kg). Methods: Experimental study. Two target points in each cadaver head were used (target point 1: caudate nucleus, target point 2: piriform lobe). Comparison between groups was performed using the independent Student's t test or the nonparametric Mann‐Whitney U Test. Results: The total median target point deviation was 0.83 mm (range 0.09‐2.76 mm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57 mm (range: 0.09‐1.25 mm) and 0.85 mm (range: 0.14‐2.76 mm), respectively. Conclusion and Clinical Importance: This magnetic resonance imaging‐based 3D printed stereotactic brain biopsy device achieved an application accuracy that was better than the accuracy of most brain biopsy systems that are currently used in veterinary medicine. The device can be applied to every size and shape of skull and allows precise positioning of brain biopsy needles in dogs

Graph complexity analysis identifies an ETV5 tumor-specific network in human and murine low-grade glioma

Conventional differential expression analyses have been successfully employed to identify genes whose levels change across experimental conditions. One limitation of this approach is the inability to discover central regulators that control gene expression networks. In addition, while methods for identifying central nodes in a network are widely implemented, the bioinformatics validation process and the theoretical error estimates that reflect the uncertainty in each step of the analysis are rarely considered. Using the betweenness centrality measure, we identified Etv5 as a potential tissue-level regulator in murine neurofibromatosis type 1 (Nf1) low-grade brain tumors (optic gliomas). As such, the expression of Etv5 and Etv5 target genes were increased in multiple independently-generated mouse optic glioma models relative to non-neoplastic (normal healthy) optic nerves, as well as in the cognate human tumors (pilocytic astrocytoma) relative to normal human brain. Importantly, differential Etv5 and Etv5 network expression was not directly the result of Nf1 gene dysfunction in specific cell types, but rather reflects a property of the tumor as an aggregate tissue. Moreover, this differential Etv5 expression was independently validated at the RNA and protein levels. Taken together, the combined use of network analysis, differential RNA expression findings, and experimental validation highlights the potential of the computational network approach to provide new insights into tumor biology

Whole tumor RNA-sequencing and deconvolution reveal a clinically-prognostic PTEN/PI3K-regulated glioma transcriptional signature

The concept that solid tumors are maintained by a productive interplay between neoplastic and non-neoplastic elements has gained traction with the demonstration that stromal fibroblasts and immune system cells dictate cancer development and progression. While less studied, brain tumor (glioma) biology is likewise influenced by non-neoplastic immune system cells (macrophages and microglia) which interact with neoplastic glioma cells to create a unique physiological state (glioma ecosystem) distinct from that found in the normal tissue. To explore this neoplastic ground state, we leveraged several preclinical mouse models of neurofibromatosis type 1 (NF1) optic glioma, a low-grade astrocytoma whose formation and maintenance requires productive interactions between non-neoplastic and neoplastic cells, and employed whole tumor RNA-sequencing and mathematical deconvolution strategies to characterize this low-grade glioma ecosystem as an aggregate of cellular and acellular elements. Using this approach, we demonstrate that optic gliomas generated by altering the germlin