Faulting in prospective CO2 storage sites in the UK Southern North Sea

Post-depositional folding of Triassic strata, formed largely by the development of salt domes and pillows in the underlying Zechstein Group, led to the formation of numerous large anticlinal structures at the level of the Triassic aged Bunter Sandstone Formation (BSF). These structural closures, some of which have formed effective traps to natural gas, have been mapped across the UK Southern North Sea (SNS), and are currently of interest as potential prospects for the storage of anthropogenic CO2

Bird Migration Through A Mountain Pass Studied With High Resolution Radar, Ceilometers, And Census

Autumnal migration was studied with high-resolution radar, ceilometer, and daily census in the area of Franconia Notch, a major pass in the northern Appalachian Mountains. Under synoptic conditions favorable for migration, broadfront movements of migrants toward the south passed over the mountains, often above a temperature inversion. Birds at lower elevations appeared to be influenced by local topography. Birds moving southwest were concentrated along the face of the mountain range. Birds appeared to deviate their flights to follow local topography through the pass. Specific migratory behavior was not associated with species or species groups. Under synoptic conditions unfavorable for southward migration, multimodal movements probably associated with local flights were as dense as the southward migrations described above. Avian migrants reacting to local terrain may result in concentrations of migrants over ridge summits or other topographic features

Inserting Migrants into the Global Social Protection Floor

The social protection floor (SPF) is a global initiative led by the International Labour Organization (ILO) to provide social security to vulnerable groups. The SPF neglects the rapidly growing population of international migrants and focusses principally on citizens from lower-income countries. The SPF requires a method to evaluate the social protection gap that exists between citizens and non-citizens in countries that receive migrants in order to improve protections for all. The SPF Advisory Group must collaborate more closely with transit and receiving countries, middle- and high-income countries, and regional organizations to reduce the gaps in social protection between citizens and non-citizens

Libraries and Student Retention

Mick Williams presented the workshop “Libraries and Student Retention” at the June 2015 Association of Christian Librarians Conference. This article of the same name encapsulates key points that were shared during the workshop’s PowerPoint presentation on how academic librarians can actively promote student retention at their own institutions of higher learning

Alternation-Trading Proofs, Linear Programming, and Lower Bounds

A fertile area of recent research has demonstrated concrete polynomial time lower bounds for solving natural hard problems on restricted computational models. Among these problems are Satisfiability, Vertex Cover, Hamilton Path, Mod6-SAT, Majority-of-Majority-SAT, and Tautologies, to name a few. The proofs of these lower bounds follow a certain proof-by-contradiction strategy that we call alternation-trading. An important open problem is to determine how powerful such proofs can possibly be. We propose a methodology for studying these proofs that makes them amenable to both formal analysis and automated theorem proving. We prove that the search for better lower bounds can often be turned into a problem of solving a large series of linear programming instances. Implementing a small-scale theorem prover based on this result, we extract new human-readable time lower bounds for several problems. This framework can also be used to prove concrete limitations on the current techniques.Comment: To appear in STACS 2010, 12 page

Rethinking university assessment

Developments in globalisation and new technologies are making significant impacts in higher education. Universities in a global market are increasingly concerned to reorient their degree programmes to meet the vocational needs of the Knowledge Economy. A growing adoption of technology enhanced learning, through blended and networked learning, has the potential to transform higher education practice – but assessment methods have been slow to change. This paper argues the case for universities to align assessment methods to meet the needs of 21st Century knowledge workers. It identifies skills and dispositions associated with graduate occupations in the Knowledge Economy, informing a new conceptual model for assessment. Radical recommendations are made to faculty staff and university policymakers: instead of centring assessment on the personal, academic achievements of individuals at the end of a degree course, the focus should instead be on the quality of the collective, applied achievements of students operating in project teams

New algorithms and lower bounds for circuits with linear threshold gates

Let $ACC \circ THR$ be the class of constant-depth circuits comprised of AND, OR, and MOD$m$ gates (for some constant $m > 1$), with a bottom layer of gates computing arbitrary linear threshold functions. This class of circuits can be seen as a "midpoint" between $ACC$ (where we know nontrivial lower bounds) and depth-two linear threshold circuits (where nontrivial lower bounds remain open). We give an algorithm for evaluating an arbitrary symmetric function of $2^{n^{o(1)}}$ $ACC \circ THR$ circuits of size $2^{n^{o(1)}}$, on all possible inputs, in $2^n \cdot poly(n)$ time. Several consequences are derived: $\bullet$ The number of satisfying assignments to an $ACC \circ THR$ circuit of subexponential size can be computed in $2^{n-n^{\varepsilon}}$ time (where $\varepsilon > 0$ depends on the depth and modulus of the circuit). $\bullet$ $NEXP$ does not have quasi-polynomial size $ACC \circ THR$ circuits, nor does $NEXP$ have quasi-polynomial size $ACC \circ SYM$ circuits. Nontrivial size lower bounds were not known even for $AND \circ OR \circ THR$ circuits. $\bullet$ Every 0-1 integer linear program with $n$ Boolean variables and $s$ linear constraints is solvable in $2^{n-\Omega(n/((\log M)(\log s)^{5}))}\cdot poly(s,n,M)$ time with high probability, where $M$ upper bounds the bit complexity of the coefficients. (For example, 0-1 integer programs with weights in $[-2^{poly(n)},2^{poly(n)}]$ and $poly(n)$ constraints can be solved in $2^{n-\Omega(n/\log^6 n)}$ time.) We also present an algorithm for evaluating depth-two linear threshold circuits (a.k.a., $THR \circ THR$) with exponential weights and $2^{n/24}$ size on all $2^n$ input assignments, running in $2^n \cdot poly(n)$ time. This is evidence that non-uniform lower bounds for $THR \circ THR$ are within reach