Security Scenario Generator (SecGen): A Framework for Generating Randomly Vulnerable Rich-scenario VMs for Learning Computer Security and Hosting CTF Events

Computer security students benefit from hands-on experience applying security tools and techniques to attack and defend vulnerable systems. Virtual machines (VMs) provide an effective way of sharing targets for hacking. However, developing these hacking challenges is time consuming, and once created, essentially static. That is, once the challenge has been "solved" there is no remaining challenge for the student, and if the challenge is created for a competition or assessment, the challenge cannot be reused without risking plagiarism, and collusion. Security Scenario Generator (SecGen) can build complex VMs based on randomised scenarios, with a number of diverse use-cases, including: building networks of VMs with randomised services and in-thewild vulnerabilities and with themed content, which can form the basis of penetration testing activities; VMs for educational lab use; and VMs with randomised CTF challenges. SecGen has a modular architecture which can dynamically generate challenges by nesting modules, and a hints generation system, which is designed to provide scaffolding for novice security students to make progress on complex challenges. SecGen has been used for teaching at universities, and hosting a recent UK-wide CTF event

Hydrologic Terrain Processing Using Parallel Computing

Abstract: Topography in the form of Digital Elevation Models (DEMs), is widely used to derive information for the modeling of hydrologic processes. Hydrologic terrain analysis augments the information content of digital elevation data by removing spurious pits, deriving a structured flow field, and calculating surfaces of hydrologic information derived from the flow field. The increasing availability of large terrain datasets with very small ground sample distance (GSD) poses a challenge for existing algorithms that process terrain data to extract this hydrologic information. This paper will describe a parallel algorithm that has been developed to enhance hydrologic terrain pre-processing so that larger datasets can be more efficiently computed. This paper describes a Message Passing Interface (MPI) parallel implementation for Pit Removal. This key functionality is used within the Terrain Analysis Using Digital Elevation Models (TauDEM) package to remove spurious elevation depressions that are an artifact of the raster representation of the terrain. The parallel algorithm works by decomposing the domain into stripes or tiles where each tile is processed by a separate processor. This method also reduces the memory requirements of each processor so that larger size grids can be processed. The parallel pit removal algorithm is adapted from the method of Planchon and Darboux that starts from a large elevation then iteratively scans the grid, lowering each grid cell to the maximum of the original elevation or the lowest neighbor. The MPI implementation reconcile

Hackerbot: Attacker Chatbots for Randomised and Interactive Security Labs, Using SecGen and oVirt

Capture the flag (CTF) has been applied with success in cybersecurity education, and works particularly well when learning offensive techniques. However, defensive security and incident response do not always naturally fit the existing approaches to CTF. We present Hackerbot, a unique approach for teaching computer security: students interact with a malicious attacker chatbot, who challenges them to complete a variety of security tasks, including defensive and investigatory challenges. Challenges are randomised using SecGen, and deployed onto an oVirt infrastructure. Evaluation data included system performance, mixed methods questionnaires (including the Instructional Materials Motivation Survey (IMMS) and the System Usability Scale (SUS)), and group interviews/focus groups. Results were encouraging, finding the approach convenient, engaging, fun, and interactive; while significantly decreasing the manual marking workload for staff. The cloud infrastructure deployment using SecGen/oVirt was a success, generating VMs with randomised challenges, and enabling students to work from home

Cost-effectiveness of problem-solving treatment in comparison with usual care for primary care patients with menthal health problems: a randomized trial

BACKGROUND: Mental health problems are common and are associated with increased disability and health care costs. Problem-Solving Treatment (PST) delivered to these patients by nurses in primary care might be efficient. The aim of this study was to evaluate the cost-effectiveness of PST by mental health nurses compared with usual care (UC) by the general practitioner for primary care patients with mental health problems. METHODS: An economic evaluation from a societal perspective was performed alongside a randomized clinical trial. Patients with a positive General Health Questionnaire score (score ≥ 4) and who visited their general practitioner at least three times during the past 6 months were eligible. Outcome measures were improvement on the Hospital Anxiety and Depression Scale and QALYs based on the EQ-5D. Resource use was measured using a validated questionnaire. Missing cost and effect data were imputed using multiple imputation techniques. Bootstrapping was used to analyze costs and cost-effectiveness of PST compared with UC. RESULTS: There were no statistically significant differences in clinical outcomes at 9 months. Mean total costs were €4795 in the PST group and €6857 in the UC group. Costs were not statistically significantly different between the two groups (95% CI -4698;359). The cost-effectiveness analysis showed that PST was cost-effective in comparison with UC. Sensitivity analyses confirmed these findings. CONCLUSIONS: PST delivered by nurses seems cost-effective in comparison with UC. However, these results should be interpreted with caution, since the difference in total costs was mainly caused by 3 outliers with extremely high indirect costs in the UC group. TRIAL REGISTRATION: Nederlands Trial Register ISRCTN5102101

Gender specific effects of the calcium channel TRPV4 on osteoporotic fracture risk and osteoblast-osteoclast coupling

TRPV4 is a member of the transient receptor potential (TRP) superfamily and responds to an array of stimuli, including osmolarity, pH and pressure. Recent findings showing that TRPV4 deficiency leads to reduced sensing of mechanical stimuli led us to explore the role of TRPV4 in bone. TRPV4 mRNA was abundantly expressed in both osteoblasts and osteoclasts as assessed by qPCR. Femoral cortical and trabecular bone mass as assessed by microcomputed tomography was higher in male TRPV4 knockout mice compared to wild type mice. Despite thicker bone structures, cortical porosity was increased in the male TRPV4 knockout mice leading to reduced bone strength as assessed by 3-point bending. Osteoclast and osteoblast differentiation and function was studied, using bone marrow cultures from wildtype and TRPV4 knockout mice. Osteoclast numbers as well as the formation of resorption pits were significantly reduced in cultures of TRPV4 knockout mice compared to wildtype littermates. In contrast, osteoblast differentiation and matrix mineralization was significantly increased in TRPV4 knockout bone marrow cultures. None of these parameters were significantly different in bones and bone marrow cultures of female knock out mice. These data implicate a gender-specific osteoblast–osteoclast uncoupling and support the observed increase in bone mass in male TRPV4 deficient mice. To assess the possible impact of TRPV4 on osteoporotic outcome in humans, we extracted data from the genome-wide association study within the Rotterdam Study. Two single nucleotide polymorphisms (SNPs) in the TRPV4 gene showed strong associations with osteoporotic fracture risk fragility fracture risk and hip fracture risk in men, but not in women. This was not affected after adjusting for height, weight, age and bone mineral density (BMD). In conclusion, TRPV4 plays an important role in male but not female bone biology. Apparently, the increased periosteal bone apposition fails to overcome the increased cortical porosity, leading to reduced bone strength in TRPV4 deficient male mice. In line with the gender-specific findings in mice, variations in the TRPV4 gene are predicting fracture risk in men but not in women

Distress and quality of life after autologous stem cell transplantation: a randomized clinical trial to evaluate the outcome of a web-based stepped care intervention

Background Psychological distress (i.e. depression and anxiety) is a strong predictor of functional status and other aspects of quality of life in autologous stem cell transplantation following high-dose chemotherapy. Treatment of psychological distress is hypothesized to result in improvement of functional status and other aspects of quality of life. The aim is to evaluate the outcome of stepped care for psychological distress on functional status and other aspects of quality of life in patients with hematological malignancy treated with autologous stem cell transplantation. Methods/Design The study is designed as a randomized clinical trial with 2 treatment arms: a stepped care intervention program versus care as usual. Patients are randomized immediately pre transplant. Stepped care and care as usual are initiated after a 6 weeks buffer period. Outcome is evaluated at 13, 30, and 42 weeks post transplant. In the experimental group, the first step includes an Internet-based self-help program. If psychological distress persists after the self-help intervention, the second step of the program is executed, i.e. a diagnostic evaluation and a standardized interview, yielding a problem analysis. Based on this information, a contract is made with the patient and treatment is provided consisting of individual face-to-face counseling, medication, or referral to other services. Care as usual comprises an interview with the patient, on ad hoc basis; emotional support and advice, on ad hoc basis; if urgent problems emerge, the patient is referred to other services. Primary outcome variables are psychological distress and functional status. Data are analyzed according to the intention to treat-principle. Discussion This study has several innovative characteristics. First, the outcome of the intervention for psychological distress in patients with hematological malignancy treated with autologous stem cell transplantation is evaluated in a randomized controlled study. Second, the impact of the intervention on functional status is evaluated: it is hypothesized that reduction of psychological distress results in improved functional status. Furthermore, the intervention concerns an Internet-based treatment in the first step. Finally, the intervention is characterized by an emphasis on self-management, efficiency, and a multi-disciplinary approach with nurses taking up a central role