Covert Channels in SIP for VoIP signalling

In this paper, we evaluate available steganographic techniques for SIP (Session Initiation Protocol) that can be used for creating covert channels during signaling phase of VoIP (Voice over IP) call. Apart from characterizing existing steganographic methods we provide new insights by introducing new techniques. We also estimate amount of data that can be transferred in signalling messages for typical IP telephony call.Comment: 8 pages, 4 figure

NICE – impact on glaucoma case detection

Aim:  To investigate the impact of publication of the National Institute of Clinical Excellence (NICE) guidelines (‘Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension’) in April 2009, on the referrals for suspect glaucoma to Moorfields Community Eye Clinic (MCEC) at Ealing Hospital. / Methods:  The clinical data from all optometrist initiated referrals for suspect glaucoma and ocular hypertension were scrutinised by a Consultant Ophthalmologist for a 2 month period, 6 months after the publication of the NICE guidance. Each was then categorised into the following groups: glaucoma positive; glaucoma suspect; glaucoma negative; ocular hypertension (OHT) requiring further follow up in clinic; ocular hypertension to be followed up by community optometrist; other. The positive predictive value (PPV) was then calculated and a historical comparison made with previous studies. / Results:  A total of 110 new referrals were assessed during the collection period, which reflects a marked increase in numbers attending. However, there was no increase in absolute numbers of glaucoma and glaucoma suspects identified. The absolute numbers of ocular hypertensive patients rose. The PPV fell to 0.25, which is lower than found in previous studies. / Conclusions:  The rising number of new referrals and the unchanged absolute numbers of glaucoma and glaucoma suspects identified following publication of the NICE guidance, in addition to a lower PPV, makes us question what advantage in improved case detection this represents. Furthermore, is this a cost effective strategy? We believe the next step is to introduce a repeat review, with carefully considered clinical governance of any new scheme

A qualitative study of the contribution of pharmacists to heart failure management in Scotland

Study objectives: (1) To identify the medication management needs of chronic heart failure (CHF) patients and their caregivers; (2) To examine the perceived support for medication management available to these people from health professionals; (3) To identify the actual and potential perceived contribution of pharmacists to medication management. Setting: A mixed urban/ rural region in the west of Scotland. Design: Semi-structured qualitative research interviews. Participants: A total of 50 people with CHF (NYHA Class II and III) due to left ventricular systolic dysfunction (33 males; mean age 67 years, 17 females; mean age 68 years) and 30 nominated caregivers recruited from the outpatient departments of two hospitals in the West of Scotland. Sampling was purposive to include patients from a range of CHF severity, ages and sexes. Main results: Managing medications was a responsibility shared by both the patients with CHF and caregivers. Treatment regimens were reported to be difficult to comply with. Health professionals were seen to provide little support for medication management. Pharmacists were viewed as being a good and accessible source of practical assistance who were also knowledgeable about the individual’s heart health history. Participants reported valuing advice from pharmacists about the side effects of medications and for their assistance in reducing the complex logistics of medication management and in having medications delivered. Conclusions: Patients with CHF and caregivers voiced a willingness to try to manage their medication regimen accurately but had a limited capacity to do so. Pharmacists were viewed as providing valuable support to patients with CHF and their caregivers, in terms of medication management. The extended role of pharmacists in medication management of CHF should be encouraged

Journey into the user experience: creating a library website that's not for librarians

Auckland University of Technology Library started work on a major redevelopment of its website in 2012. The problem was that the website content, as is the case for many library websites, had been written by librarians with almost no user input. The challenge was to redesign the website, rethinking our entire focus and placing the user at the centre of the process. This is the story of a journey of transformational change based on our user-centric approach. We believe we have achieved what we set out to do and created a website that’s built not for librarians but for users

Transparency Enhancing Technologies to Make Security Protocols Work for Humans

As computer systems are increasingly relied on to make decisions that will have significant consequences, it has also become important to provide not only standard security guarantees for the computer system but also ways of explaining the output of the system in case of possible errors and disputes. This translates to new security requirements in terms of human needs rather than technical properties. For some context, we look at prior disputes regarding banking security and the ongoing litigation concerning the Post Office’s Horizon system, discussing the difficulty in achieving meaningful transparency and how to better evaluate available evidence

Dovetail: Stronger Anonymity in Next-Generation Internet Routing

Current low-latency anonymity systems use complex overlay networks to conceal a user's IP address, introducing significant latency and network efficiency penalties compared to normal Internet usage. Rather than obfuscating network identity through higher level protocols, we propose a more direct solution: a routing protocol that allows communication without exposing network identity, providing a strong foundation for Internet privacy, while allowing identity to be defined in those higher level protocols where it adds value. Given current research initiatives advocating "clean slate" Internet designs, an opportunity exists to design an internetwork layer routing protocol that decouples identity from network location and thereby simplifies the anonymity problem. Recently, Hsiao et al. proposed such a protocol (LAP), but it does not protect the user against a local eavesdropper or an untrusted ISP, which will not be acceptable for many users. Thus, we propose Dovetail, a next-generation Internet routing protocol that provides anonymity against an active attacker located at any single point within the network, including the user's ISP. A major design challenge is to provide this protection without including an application-layer proxy in data transmission. We address this challenge in path construction by using a matchmaker node (an end host) to overlap two path segments at a dovetail node (a router). The dovetail then trims away part of the path so that data transmission bypasses the matchmaker. Additional design features include the choice of many different paths through the network and the joining of path segments without requiring a trusted third party. We develop a systematic mechanism to measure the topological anonymity of our designs, and we demonstrate the privacy and efficiency of our proposal by simulation, using a model of the complete Internet at the AS-level

Understanding the production of dual BEC with sympathetic cooling

We show, both experimentally and theoretically, that sympathetic cooling of $^{87}$Rb atoms in the $|F=2,m_F=2>$ state by evaporatively cooled atoms in the $|F=1,m_F=-1>$ state can be precisely controlled to produce dual or single condensate in either state. We also study the thermalization rate between two species. Our model renders a quantitative account of the observed role of the overlap between the two clouds and points out that sympathetic cooling becomes inefficient when the masses are very different. Our calculation also yields an analytical expression of the thermalization rate for a single species.Comment: 3 figure