YSO jets in the Galactic Plane from UWISH2: I - MHO catalogue for Serpens and Aquila

Jets and outflows from Young Stellar Objects (YSOs) are important signposts of currently ongoing star formation. In order to study these objects we are conducting an unbiased survey along the Galactic Plane in the 1-0S(1) emission line of molecular hydrogen at 2.122mu using the UK Infrared Telescope. In this paper we are focusing on a 33 square degree sized region in Serpens and Aquila (18deg < l < 30deg; -1.5deg < b < +1.5deg). We trace 131 jets and outflows from YSOs, which results in a 15 fold increase in the total number of known Molecular Hydrogen Outflows. Compared to this, the total integrated 1-0S(1) flux of all objects just about doubles, since the known objects occupy the bright end of the flux distribution. Our completeness limit is 3*10^-18Wm^-2 with 70% of the objects having fluxes of less than 10^-17Wm^-2. Generally, the flows are associated with Giant Molecular Cloud complexes and have a scale height of 25-30pc with respect to the Galactic Plane. We are able to assign potential source candidates to about half the objects. Typically, the flows are clustered in groups of 3-5 objects, within a radius of 5pc. These groups are separated on average by about half a degree, and 2/3rd of the entire survey area is devoid of outflows. We find a large range of apparent outflow lengths from 4arcsec to 130arcsec. If we assume a distance of 3kpc, only 10% of all outflows are of parsec scale. There is a 2.6sigma over abundance of flow position angles roughly perpendicular to the Galactic Plane.Comment: 13pages, 1table (Appendix B not included), 6figures, accepted for publication by MNRAS, a version with higher resolution figures can be found at http://astro.kent.ac.uk/~df

xPF: Packet Filtering for Low-Cost Network Monitoring

The ever-increasing complexity in network infrastructures is making critical the demand for network monitoring tools. While the majority of network operators rely on low-cost open-source tools based on commodity hardware and operating systems, the increasing link speeds and complexity of network monitoring applications have revealed inefficiencies in the existing software organization, which may prohibit the use of such tools in high-speed networks. Although several new architectures have been proposed to address these problems, they require significant effort in re-engineering the existing body of applications. We present an alternative approach that addresses the primary sources of inefficiency without significantly altering the software structure. Specifically, we enhance the computational model of the Berkeley packet filter (BPF) to move much of the processing associated with monitoring into the kernel, thereby removing the overhead associated with context switching between kernel and applications. The resulting packet filter, called xPF, allows new tools to be more efficiently implemented and existing tools to be easily optimized for high-speed networks. We present the design and implementation of xPF as well as several example applications that demonstrate the efficiency of our approach

Truth, Probability, and Frameworks

Yeshttp://www.plosmedicine.org/static/editorial#pee

WebDAVA: An Administrator-Free Approach To Web File-Sharing

Collaboration over the Internet depends on the ability of the members of a group to exchange data in a secure yet unobtrusive manner. WebDAVA is a system that allows the users to define their own access-control policies to network resources that they control, enabling secure data sharing within the enterprise. Our design allows users to selectively give fine-grain access to their resources without involving their system administrators. We accomplish this by using authorization credentials that define the users' privileges. Our prototype implements a file-sharing service, where users maintain sensitive-information folders and can allow others to access parts of these. Clients interact with the server over HTTP via a Java applet that transparently handles credential management. This mechanism allows users to share information with users not a priori known to the system, enabling administrator-free management

Design and Implementation of Virtual Private Services

Large scale distributed applications such as electronic commerce and online marketplaces combine network access with multiple storage and computational elements. The distributed responsibility for resource control creates new security and privacy issues, which are exacerbated by the complexity of the operating environment. In order to handle policies at multiple locations, the usual tools available (firewalls and compartmented file storage) get to be used in ways that are clumsy and prone to failure. We propose a new approach, virtual private services. Our approach relies on two functional divisions. First, we split policy specification and policy enforcement, providing local autonomy within the constraints of the global security policy. Second, we create virtual security domains, each with its own security policy. Every domain has an associated set of privileges and permissions restricting it to the resources it needs to use and the services it must perform. Virtual private services ensure security and privacy policies are adhered to through coordinated policy enforcement points. We describe our architecture and a prototype implementation, and present a preliminary performance evaluation confirming that our overhead of policy enforcement using is small

Discrete Choice, Social Interaction, and Policy in Encryption Technology Adoption

We introduce a model for examining the factors that lead to the adoption of new encryption technologies. Building on the work of Brock and Durlauf, the model describes how agents make choices, in the presence of social interaction, between competing technologies given their relative cost, functionality, and usability. We apply the model to examples about the adoption of encryption in communication (email and messaging) and storage technologies (self-encrypting drives) and also consider our model’s predictions for the evolution of technology adoption over time

TAPI: Transactions for Accessing Public Infrastructure

This paper describes TAPI, an offline scheme intended for general Internet-based micropayments. TAPI, which extends and combines concepts from the KeyNote Microchecks and OTPCoins architectures, encodes risk management rules in bank-issued users' credentials which are in turn used to acquire small-valued payment tokens. The scheme has very low transaction overhead and can be tuned to use different risk strategies for different environments and clients

Virtual Private Services: Coordinated Policy Enforcement for Distributed Applications

Large scale distributed applications combine network access with multiple storage and computational elements. The distributed responsibility for resource control creates new security issues, caused by the complexity of the operating environment. In particular, policies at multiple layers and locations force conventional mechanisms such as firewalls and compartmented file storage into roles where they are clumsy and failure-prone. Our approach relies on two functional divisions. First, we split policy specification and policy enforcement, providing local autonomy within the constraints of the global security policy. Second, we create virtual security domains each with its own security policy. Every domain has an associated set of privileges and permissions restricting it to the resources it needs to use and the services it must perform. Virtual private services ensure security and privacy policies are adhered to through coordinated policy enforcement points

Health outcomes during the 2008 financial crisis in Europe: systematic literature review

OBJECTIVE:  To systematically identify, critically appraise, and synthesise empirical studies about the impact of the 2008 financial crisis in Europe on health outcomes. DESIGN:  Systematic literature review. DATA SOURCES:  Structural searches of key databases, healthcare journals, and organisation based websites. REVIEW METHODS:  Empirical studies reporting on the impact of the financial crisis on health outcomes in Europe, published from January 2008 to December 2015, were included. All selected studies were assessed for risk of bias. Owing to the heterogeneity of studies in terms of study design and analysis and the use of overlapping datasets across studies, studies were analysed thematically per outcome, and the evidence was synthesised on different health outcomes without formal meta-analysis. RESULTS:  41 studies met the inclusion criteria, and focused on suicide, mental health, self rated health, mortality, and other health outcomes. Of those studies, 30 (73%) were deemed to be at high risk of bias, nine (22%) at moderate risk of bias, and only two (5%) at low risk of bias, limiting the conclusions that can be drawn. Although there were differences across countries and groups, there was some indication that suicides increased and mental health deteriorated during the crisis. The crisis did not seem to reverse the trend of decreasing overall mortality. Evidence on self rated health and other indicators was mixed. CONCLUSIONS:  Most published studies on the impact of financial crisis on health in Europe had a substantial risk of bias; therefore, results need to be cautiously interpreted. Overall, the financial crisis in Europe seemed to have had heterogeneous effects on health outcomes, with the evidence being most consistent for suicides and mental health. There is a need for better empirical studies, especially those focused on identifying mechanisms that can mitigate the adverse effects of the crisis