Food reward sensitivity predicts overconsumption of high-fat snack food

Overconsumption of snack foods has been linked to rising rates of obesity, with our ‘obesogenic’ environment and its abundance of palatable, high-calorie foods and associated cues especially implicated. However, it is clear that some individuals are particularly susceptible to overconsumption and weight gain. It was hypothesised that individuals sensitive to the rewarding properties of palatable foods, and associated stimuli, would show elevated consumption. Snack food intake was measured in 50 adults (mean age 34.5 years, BMI 23.9 kg/m2, 56% female) in a repeated measures design, both with and without a ‘food cue’. Trait (BIS/BAS scales), behavioural (computerised CARROT) and food reward were assessed. Sensitivity to food reward, but not generalised reward, was positively associated with snack food intake. This relationship was not affected by the presence of a food cue. Findings are discussed in the context of implications for weight management.

Thinking Pedagogically

Despite the dominancy of medical explanations for difficult child behavior, the shifting sands that lie beneath the ADHD construct provide an unstable foundation for educational practice. It can be somewhat liberating to remember that “attention deficit hyperactivity disorder” is a label (one of many, including minimal brain damage and hyperkinetic reaction of childhood) that the medical domain has coined to both group and describe certain challenging behaviors exhibited by children and young people (see Smith, Chapter 2). The label is but one conceptualization of what these behaviors mean and, despite the existence of powerful lobby groups, it may not be the best way forward. In what follows, I present an alternative typology to the medical conceptualization by describing some common issues that bring this group of children to attention. In an effort to introduce educationally useful responses to students who are difficult to teach, I will then outline what classroom teachers need to recognize in order to work with these students and realize their potential. To assist teachers in thinking pedagogically, these observations are coupled with well-known and relevant qualities of good teaching to remind teachers of what they already know and to reacquaint them with the power of that knowledge.

Much confusion about inclusion in Australia's largest education system

Over the last three decades, growing international recognition of the right of students with a disability to attend their local school has prompted change in the formation of education policies, schooling structures and pedagogical practice. Inclusion, as the movement has become known, has since been taken up and developed to different degrees in different regions and to differing degrees of success. Yet, despite sincere attempts to better include students with physical, sensory and intellectual disabilities, new and different forms of exclusion have arisen since the late 1990s; particularly for students with social, emotional and/or behavioural difficulties. In this lecture, Dr Linda Graham reports on findings from a three year ARC Discovery project to consider the impact of inclusion on the New South Wales government schooling sector, Australia’s largest education system.

Efficient selective identity-based encryption without random oracles

We construct two efficient Identity-Based Encryption (IBE) systems that admit selective-identity security reductions without random oracles in groups equipped with a bilinear map. Selective-identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to the identity that it intends to attack, whereas in an adaptive-identity attack the adversary is allowed to choose this identity adaptively. Our first system—BB1—is based on the well studied decisional bilinear Diffie–Hellman assumption, and extends naturally to systems with hierarchical identities, or HIBE. Our second system—BB2—is based on a stronger assumption which we call the Bilinear Diffie–Hellman Inversion assumption and provides another approach to building IBE systems. Our first system, BB1, is very versatile and well suited for practical applications: the basic hierarchical construction can be efficiently secured against chosen-ciphertext attacks, and further extended to support efficient non-interactive threshold decryption, among others, all without using random oracles. Both systems, BB1 and BB2, can be modified generically to provide “full” IBE security (i.e., against adaptive-identity attacks), either using random oracles, or in the standard model at the expense of a non-polynomial but easy-to-compensate security reduction.

Kamouflage : loss-resistant password management

We introduce Kamouflage: a new architecture for building theft-resistant password managers. An attacker who steals a laptop or cell phone with a Kamouflage-based password manager is forced to carry out a considerable amount of online work before obtaining any user credentials. We implemented our proposal as a replacement for the built-in Firefox password manager, and provide performance measurements and the results from experiments with large real-world password sets to evaluate the feasibility and effectiveness of our approach. Kamouflage is well suited to become a standard architecture for password managers on mobile devices.

Lattice basis delegation in fixed dimension and shorter-ciphertext hierarchical IBE

We present a technique for delegating a short lattice basis that has the advantage of keeping the lattice dimension unchanged upon delegation. Building on this result, we construct two new hierarchical identity-based encryption (HIBE) schemes, with and without random oracles. The resulting systems are very different from earlier lattice-based HIBEs and in some cases result in shorter ciphertexts and private keys. We prove security from classic lattice hardness assumptions.

Efficient lattice (H)IBE in the standard model

We construct an efficient identity based encryption system based on the standard learning with errors (LWE) problem. Our security proof holds in the standard model. The key step in the construction is a family of lattices for which there are two distinct trapdoors for finding short vectors. One trapdoor enables the real system to generate short vectors in all lattices in the family. The other trapdoor enables the simulator to generate short vectors for all lattices in the family except for one. We extend this basic technique to an adaptively-secure IBE and a Hierarchical IBE.

Preventing pollution attacks in multi-source network coding

Network coding is a method for achieving channel capacity in networks. The key idea is to allow network routers to linearly mix packets as they traverse the network so that recipients receive linear combinations of packets. Network coded systems are vulnerable to pollution attacks where a single malicious node floods the network with bad packets and prevents the receiver from decoding correctly. Cryptographic defenses to these problems are based on homomorphic signatures and MACs. These proposals, however, cannot handle mixing of packets from multiple sources, which is needed to achieve the full benefits of network coding. In this paper we address integrity of multi-source mixing. We propose a security model for this setting and provide a generic construction.

Short signature without random oracles and the SDH assumption in bilinear groups

We describe a short signature scheme that is strongly existentially unforgeable under an adaptive chosen message attack in the standard security model. Our construction works in groups equipped with an efficient bilinear map, or, more generally, an algorithm for the Decision Diffie-Hellman problem. The security of our scheme depends on a new intractability assumption we call Strong Diffie-Hellman (SDH), by analogy to the Strong RSA assumption with which it shares many properties. Signature generation in our system is fast and the resulting signatures are as short as DSA signatures for comparable security. We give a tight reduction proving that our scheme is secure in any group in which the SDH assumption holds, without relying on the random oracle model.

"The Stratified Record upon Which We Set Our Feet" : The Spatial Turn and the Multilayering of History, Geography, and Geology

In Thomas Mann’s tetralogy of the 1930s and 1940s, Joseph and His Brothers, the narrator declares history is not only “that which has happened and that which goes on happening in time,” but it is also “the stratified record upon which we set our feet, the ground beneath us.” By opening up history to its spatial, geographical, and geological dimensions Mann both predicts and encapsulates the twentieth-century’s “spatial turn,” a critical shift that divested geography of its largely passive role as history’s “stage” and brought to the fore intersections between the humanities and the earth sciences. In this paper, I draw out the relationships between history, narrative, geography, and geology revealed by this spatial turn and the questions these pose for thinking about the disciplinary relationship between geography and the humanities. As Mann’s statement exemplifies, the spatial turn itself has often been captured most strikingly in fiction, and I would argue nowhere more so than in Graham Swift’s Waterland (1983) and Anne Michaels’s Fugitive Pieces (1996), both of which present space, place, and landscape as having a palpable influence on history and memory. The geographical/geological line that runs through both Waterland and Fugitive Pieces continues through Tim Robinson’s non-fictional, two-volume “topographical” history Stones of Aran. Robinson’s Stones of Aran—which is not history, not geography, and not literature, and yet is all three—constructs an imaginative geography that renders inseparable geography, geology, history, memory, and the act of writing.