20 research outputs found

    Talking to the Overlooked: A Nationwide Telephone Survey with Four Groups Under-represented in Privacy and Security Studies

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    Online surveys - a primary research tool in the field of usable security and privacy research - frequently rely on web-panel platforms. However, these platforms tend not to generalize well to specific user groups. Our study addresses this research gap by studying security and privacy perceptions of four under-represented groups. We conducted telephone interviews with n = 1003 participants in Germany: (I) teenagers aged 14-17, (II) older adults 70+, (III) people with low formal education, and (IV) people with migration background. We found these groups to be under-represented in our online comparison survey. We further identified target group-specific perceptions for each group compared to the general population, e.g., regarding their experiences with cybercrime, and provide detailed insight into the privacy and security knowledge and behavior of each group. Our findings underscore the effectiveness of telephone interviews and lay the foundation for further research on these groups

    Targeting class I histone deacetylase 2 in MYC amplified group 3 medulloblastoma

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    Introduction: Medulloblastoma (MB) is the most frequent malignant brain tumor in children. Four subgroups with distinct genetic, epigenetic and clinical characteristics have been identified. Survival remains particularly poor in patients with Group 3 tumors harbouring a MYC amplification. We herein explore the molecular mechanisms and translational implications of class I histone deacetylase (HDAC) inhibition in MYC driven MBs. Material and Methods: Expression of HDACs in primary MB subgroups was compared to normal brain tissue. A panel of MB cell lines, including Group 3 MYC amplified cell lines, were used as model systems. Cells were treated with HDAC inhibitors (HDACi) selectively targeting class I or IIa HDACs. Depletion of HDAC2 was performed. Intracellular HDAC activity, cellular viability, metabolic activity, caspase activity, cell cycle progression, RNA and protein expression were analyzed. Results: HDAC2 was found to be overexpressed in MB subgroups with poor prognosis (SHH, Group 3 and Group 4) compared to normal brain and the WNT subgroup. Inhibition of the enzymatic activity of the class I HDACs reduced metabolic activity, cell number, and viability in contrast to inhibition of class IIa HDACs. Increased sensitivity to HDACi was specifically observed in MYC amplified cells. Depletion of HDAC2 increased H4 acetylation and induced cell death. Simulation of clinical pharmacokinetics showed time-dependent on target activity that correlated with binding kinetics of HDACi compounds. Conclusions: We conclude that HDAC2 is a valid drug target in patients with MYC amplified MB. HDACi should cover HDAC2 in their inhibitory profile and timing and dosing regimen in clinical trials should take binding kinetics of compounds into consideration

    Phase I/II intra-patient dose escalation study of vorinostat in children with relapsed solid tumor, lymphoma, or leukemia

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    Background: Until today, adult and pediatric clinical trials investigating single-agent or combinatorial HDAC inhibitors including vorinostat in solid tumors have largely failed to demonstrate efficacy. These results may in part be explained by data from preclinical models showing significant activity only at higher concentrations compared to those achieved with current dosing regimens. In the current pediatric trial, we applied an intra-patient dose escalation design. The purpose of this trial was to determine a safe dose recommendation (SDR) of single-agent vorinostat for intra-patient dose escalation, pharmacokinetic analyses (PK), and activity evaluation in children (3-18 years) with relapsed or therapy-refractory malignancies. Results: A phase I intra-patient dose (de)escalation was performed until individual maximum tolerated dose (MTD). The starting dose was 180 mg/m(2)/day with weekly dose escalations of 50 mg/m(2) until DLT/maximum dose. After MTD determination, patients seamlessly continued in phase II with disease assessments every 3 months. PK and plasma cytokine profiles were determined. Fifty of 52 patients received treatment. n = 27/50 (54%) completed the intra-patient (de)escalation and entered phase II. An SDR of 130 mg/m(2)/day was determined (maximum, 580 mg/m(2)/day). n = 46/50 (92%) patients experienced treatment-related AEs which were mostly reversible and included thrombocytopenia, fatigue, nausea, diarrhea, anemia, and vomiting. n = 6/50 (12%) had treatment-related SAEs. No treatment-related deaths occurred. Higher dose levels resulted in higher C-max. Five patients achieved prolonged disease control (> 12 months) and showed a higher C-max (> 270 ng/mL) and MTDs. Best overall response (combining PR and SD, no CR observed) rate in phase II was 6/27 (22%) with a median PFS and OS of 5.3 and 22.4 months. Low levels of baseline cytokine expression were significantly correlated with favorable outcome. Conclusion: An SDR of 130 mg/m(2)/day for individual dose escalation was determined. Higher drug exposure was associated with responses and long-term disease stabilization with manageable toxicity. Patients with low expression of plasma cytokine levels at baseline were able to tolerate higher doses of vorinostat and benefited from treatment. Baseline cytokine profile is a promising potential predictive biomarker

    Caring Not Scaring - An Evaluation of a Workshop to Train Apprentices as Security Champions

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    Security champions are regular employees who have deeper knowledge in information security and a direct connection with the security team. Through this connection, they can facilitate the diffusion of security knowledge to employees and back to the security team. We worked with a German organization with more than 20,000 employees that decided to create such a program, starting with a three day in-person workshop with n = 17 young apprentices to train them to become security champions. Internal and external speakers were invited, to pass on their security knowledge to the apprentices. We contributed to the workshop program with Serious LEGO, security mythbusting exercises, and Q&amp;A sessions. However, our main goal was to evaluate the workshops' impact on the participants. We gathered data through interviews, surveys and observation before, during and after the workshop. We found that the workshop did indeed influence the security behavior of young employees. However, the external security experts presented outdated or incorrect security knowledge, and recommended secure behaviours that contradicted company security policies. We identified incentives and motivations that participants brought to the role. In addition to tailoring security training content appropriately, we identify preparatory steps, and support that organizations need to put in place to support security champions who take on the role.</p

    Characterization of the Fatigue Behaviour of Low Carbon Steels by Means of Temperature and Micromagnetic Measurements

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    Investigations on low carbon (non- and low-alloy) steels were conducted in form of load increase tests (LIT) and constant amplitude tests (CAT) to find the correlation among material behaviour, mechanical load, and the type of NDT method. With the help of preprogrammed load-free sequences, the thermal impact on magnetic Barkhausen noise (MBN) measurement can be avoided, so that the cyclic deformation properties of material responses can be interpreted more precisely. The results indicate differences between the change in temperature and the MBN-derived variable during LITs and CATs regarding the demonstration of the incubation stage and the cyclic hardening behaviour

    Prognostic relevance of miRNA-155 methylation in anaplastic glioma

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    The outcome of patients with anaplastic gliomas varies considerably depending on single molecular markers, such as mutations of the isocitrate dehydrogenase (IDH) genes, as well as molecular classifications based on epigenetic or genetic profiles. Remarkably, 98% of the RNA within a cell is not translated into proteins. Of those, especially microRNAs (miRNAs) have been shown not only to have a major influence on physiologic processes but also to be deregulated and prognostic in malignancies. To find novel survival markers and treatment options we performed unbiased DNA methylation screens that revealed 12 putative miRNA promoter regions with differential DNA methylation in anaplastic gliomas. Methylation of these candidate regions was validated in different independent patient cohorts revealing a set of miRNA promoter regions with prognostic relevance across data sets. Of those, miR-155 promoter methylation and miR-155 expression were negatively correlated and especially the methylation showed superior correlation with patient survival compared to established biomarkers. Functional examinations in malignant glioma cells further cemented the relevance of miR-155 for tumor cell viability with transient and stable modifications indicating an onco-miRNA activity. MiR-155 also conferred resistance towards alkylating temozolomide and radiotherapy as consequence of nuclear factor (NF)kappa B activation. Preconditioning glioma cells with an NF kappa B inhibitor reduced therapy resistance of miR-155 overexpressing cells. These cells resembled tumors with a low methylation of the miR-155 promoter and thus mir-155 or NF kappa B inhibition may provide treatment options with a special focus on patients with IDH wild type tumors
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