Early exposure to environmental toxin contributes to neuronal vulnerability and axonal pathology in a model of familial ALS

Adult onset amyotrophic lateral sclerosis (ALS) arises due to progressive and irreversible functional deficits to the central nervous system, specifically the loss of motor neurons. Sporadic ALS causality is not well understood, but is almost certainly of multifactorial origin involving a combination of genetic and environmental factors. The discovery of endemic ALS in the native Chamorro population of Guam during the 1950s and the co-occurrence of parkinsonism and dementia in some patients led to searches for an environmental toxins that could be responsible. In the present paper, we report that an environmental neurotoxin enhances mutant superoxide dismutase (SOD)-induced spinal motor neuron death and pathology and induces motor axon abnormalities. These results cumulatively confirm earlier findings that exposure to an environmental toxin is sufficient to produce the disease phenotype and indicate a role for gene-environment interaction in some forms of the disease

Decoherence induced CPT violation and entangled neutral mesons

We discuss two classes of semi-microscopic theoretical models of stochastic space-time foam in quantum gravity and the associated effects on entangled states of neutral mesons, signalling an intrinsic breakdown of CPT invariance. One class of models deals with a specific model of foam, initially constructed in the context of non-critical (Liouville) string theory, but viewed here in the more general context of effective quantum-gravity models. The relevant Hamiltonian perturbation, describing the interaction of the meson with the foam medium, consists of off-diagonal stochastic metric fluctuations, connecting distinct mass eigenstates (or the appropriate generalisation thereof in the case of K-mesons), and it is proportional to the relevant momentum transfer (along the direction of motion of the meson pair). There are two kinds of CPT-violating effects in this case, which can be experimentally disentangled: one (termed ``omega-effect'') is associated with the failure of the indistinguishability between the neutral meson and its antiparticle, and affects certain symmetry properties of the initial state of the two-meson system; the second effect is generated by the time evolution of the system in the medium of the space-time foam, and can result in time-dependent contributions of the $omega-effect type in the time profile of the two meson state. Estimates of both effects are given, which show that, at least in certain models, such effects are not far from the sensitivity of experimental facilities available currently or in the near future. The other class of quantum gravity models involves a medium of gravitational fluctuations which behaves like a ``thermal bath''. In this model both of the above-mentioned intrinsic CPT violation effects are not valid.Comment: 16 pages revtex, no figure

Book review: the sustainable economics of Elinor Ostrom: commons, contestation and craft by Derek Wall

The threat posed by global warming and environmental degradation are the most pressing examples of what has become known over the past several decades as the ‘tragedy of the commons’. In this book, Derek Wall explores the work of the late Nobel Laureate, Elinor Ostrom, on how humans can overcome this problem, and sustain the commons over the long term. Chris Shaw finds that this book is an accessible presentation of Ostrom’s ideas

Book review: climate change and post-political communication: media, emotion and environmental advocacy by Philip Hammond

In this well-written and engaging book, Climate Change and Post-Political Communication: Media, Emotion and Environmental Advocacy, Philip Hammond draws together a range of interesting perspectives on the politics of climate change. However, these ideas are employed in the service of a flawed thesis which risks misrepresenting the scientific evidence and recent political history, warns Christopher Shaw

Quantitative Literacy - Problems that Motivate

In this article, I present a selection of problem types, with examples, that have been used with some success to motivate the topics in a quantitative literacy class so that learners may begin doing mathematics without period of discussion beforehand. In their original use, the setting for these problems is a small class at a large liberal arts college, but I hope that the work described within will still have some value for teachers of high school students, especially in classes where many learners struggle to appreciate mathematics

Book Review: climate change, capitalism and corporations: processes of creative self-destruction by Christopher Wright and Daniel Nyberg

In Climate Change, Capitalism and Corporations: Processes of Creative Self-Destruction, Christopher Wright and Daniel Nyberg seek to show how businesses have constructed narratives surrounding climate change, drawing upon interviews with corporate actors. Christopher Shaw praises the book for outlining how corporations have worked to maintain their interests and promote continued market expansion as conducive to effective climate change policy. However, he questions the utility of their interviews for systemic analysis and the book’s overarching disinclination to challenge the foundational myth of a single definable limit to climate change

Design of experiment for the optimisation of deep reactive ion etching of silicon inserts for micro-fabrication

The following paper describes a design of experiments investigation of the deep reactive of pillar structures on a silicon wafer. The etched wafers would subsequently be used as masters for the fabrication of nickel mould inserts for microinjection moulding. Undercuts occur when the pillar base has a smaller cross-section than the apex of the pillar. They therefore affect tolerances of the subsequent nickel mould, its strength and its de-mouldability from the silicon form. The response measured in these experiments was the degree of undercut of micro-scale (10 μm x 10 μm x 40 μm, 5 μm x 5 μm x 40 μm and 2 μm x 2 μm x 40 μm) The literature suggests that gas pressure, platen power, gas flow rate, phase switching times and mask size can all affect the degree of undercut. After examination of this literature, and of manufacturers guidelines, three parameters were selected for experimental testing: platen power, C 4F 8 gas flow rate during the passivation phase and switching times. Switching times was found to be the only statistically significant parameter for both 10x10 μm and 5x5 μm pillars. The 2x2 μm pillars were not successfully replicated and could therefore not undergo statistical evaluation

International Proscription Against Torture and the United States’ Categorical and Qualified Responses

Although the prohibition against torture is a jus cogens and proscribed by multiple international treaties and United States law, such bans did not prevent the torture of detainees in United States’ custody. For a state truly to protect people from torture, it must rely less on definitions and prohibitions and turn to leadership and policy; proscriptions by themselves cannot stop torture—only leadership and policy can. In the case of detainees held by the United States during the war on terror, presidential leadership created an environment that allowed torture, and it was not curtailed until presidential leadership stopped it

Choosing a dangerous limit for climate change: an investigation into how the decision making process is constructed in public discourses

International climate change policy is predicated on the claim that climate change is a phenomenon with a single, global dangerous limit of two degrees of warming above the pre-industrial average. However, climate science does not provide sufficient empirical evidence to determine such an exact limit. In addition, a single limit incorrectly assumes that social and physical vulnerabilities to climate change are uniformly distributed in space and time. Public commentaries play an important role in shaping public engagement with an abstract concept such as climate change. This research project examines how public discourses construct the dangerous limits to climate change decision making process. My analysis draws on elite theory to argue that the two degree limit is a discourse which constructs climate change as a problem solvable within existing value systems and patterns of social activity. A comparison of primary and secondary data drawn from diverse sources is used to chart the key historical, social and cultural elements present in the construction and reproduction of the two degree dangerous limit discourse. The historical dimension of my analysis shows that public commentaries have ‘black boxed’ the genesis of the two degree dangerous limit idea. I demonstrate how claims of a consensus amongst elite policy and science actors are central to developing a dangerous limit ideology amongst influential public audiences. The two degree discourse elevates the idea of a single dangerous limit to the status of fact, and in so doing marginalises egalitarian and ecological perspectives. I conclude that the two degree limit is a construct which makes possible an international environmental regime safe for the interests of elite actor