4,523 research outputs found
Making War: The President and Congress
The main aim of this dissertation was to investigate the difference in neural language patternsrelated to language ability in healthy adults. The focus lies on unraveling the contributions of theright‐hemispheric homologues to Broca’s area in the inferior frontal gyrus (IFG) and Wernicke’s areain the posterior temporal and inferior parietal lobes. The functions of these regions are far from fullyunderstood at present. Two study populations consisting of healthy adults and a small group ofpeople with generalized epilepsy were investigated. Individual performance scores in tests oflanguage ability were correlated with brain activation obtained with functional magnetic resonanceimaging during semantic and word fluency tasks. Performance‐dependent differences were expectedin the left‐hemispheric Broca’s and Wernicke’s area and in their right‐hemispheric counterparts. PAPER I revealed a shift in laterality towards right‐hemispheric IFG and posterior temporal lobeactivation, related to high semantic performance. The whole‐brain analysis results of PAPER IIrevealed numerous candidate regions for language ability modulation. PAPER II also confirmed thefinding of PAPER I, by showing several performance‐dependent regions in the right‐hemispheric IFGand the posterior temporal lobe. In PAPER III, a new study population of healthy adults was tested.Again, the right posterior temporal lobe was related to high semantic performance. A decrease in lefthemisphericIFG activation could be linked to high word fluency ability. In addition, task difficultywas modulated. Increased task complexity showed to correlate positively with bilateral IFGactivation. Lastly, PAPER IV investigated anti‐correlated regions. These regions are commonly knownas the default mode network (DMN) and are normally suppressed during cognitive tasks. It wasfound that people with generalized epilepsy had an inadequate suppression of regions in the DMN,and showed poorer performance in a complex language test. The results point to neural adaptabilityin the IFG and temporal lobe. Decreased left‐lateralization of the IFG and increased rightlateralizationof the posterior temporal lobe are proposed as characteristics of individuals with highlanguage ability
An investigation into the behaviour of air rifle pellets in ballistic gel and their interaction with bone
Although air weapons are considerably lower in power than other firearms, there is increasing concern that serious injuries can result from their misuse. The present study was therefore carried out to improve understanding of the terminal ballistic behaviour of air rifle pellets. Pellets were fired into ballistic gel under a variety of conditions. The pellets penetrated further than anticipated from their low cross-sectional density, and Bloom number was not necessarily a good guide to gel behaviour. Pellet penetration into the gel decreased with increasing gel concentration, and appeared to be linear at higher concentrations. Pointed pellets penetrated up to 50% further than rounded pellets. Power and range affect penetration, but other factors are also important, and power alone is not a simple guide to potential penetration. Test firings were also carried out firing pellets into ballistic gel that contained sections of animal bone. Computed tomography (CT) and visual observation were employed to record the interactions. CT scanning showed potential as a tool for examining pellet damage. The bone appeared to be undamaged, but the pellets were severely deformed on impact. If the pellet strikes the bone at an angle, less energy is absorbed by the impact and the pellet fragments may ricochet and cause further damage in the gel. A tentative model is proposed for estimating the energy absorbed by the impact
Learning Development and Education for Sustainability: what are the links?
Learning Development (LD) is an emerging discipline developing a unique disciplinary identity. In common with many other new fields, it considers its position and relevance to other disciplines and bodies of thought, and in particular, educational development, applied linguistics and the sociology and philosophy of education. This paper considers one such area of debate: the link between Learning Development and Education for
Sustainability (EfS). EfS is an area of pedagogic practice and a field of enquiry of considerable and growing importance in Higher Education (HE) and universities. Its underpinning systemic and epistemic philosophies suggest the need for integration across
all facets of university activity, including LD. In this paper, we argue that there are identifiable links between LD and EfS that extend these philosophies, practices and fields of enquiry, characterised by the following: 1) commonalities surrounding the foci of their
pedagogic practices, 2) shared methodologies for undertaking their practices, and 3) ways in which these methodologies are helping to situate both professions and disciplines within organisational contexts. The
commonalities and possible distinctions between LD and EfS form a starting point for discussion, and raise the possibility that explicit identification of the links may encourage increased collaboration between the respective communities of practice, and the development of new ideas and innovative practice
An ultra-weak sector, the strong CP problem and the pseudo-Goldstone dilaton
In the context of a Coleman-Weinberg mechanism for the Higgs boson mass, we
address the strong CP problem. We show that a DFSZ-like invisible axion model
with a gauge-singlet complex scalar field S, whose couplings to the Standard
Model are naturally ultra-weak, can solve the strong CP problem and
simultaneously generate acceptable electroweak symmetry breaking. The
ultra-weak couplings of the singlet S are associated with underlying
approximate shift symmetries that act as custodial symmetries and maintain
technical naturalness. The model also contains a very light pseudo-Goldstone
dilaton that is consistent with cosmological Polonyi bounds, and the axion can
be the dark matter of the universe. We further outline how a SUSY version of
this model, which may be required in the context of Grand Unification, can
avoid introducing a hierarchy problem.Comment: 9 page
Ultra-weak sector, Higgs boson mass, and the dilaton
The Higgs boson mass may arise from a portal coupling to a singlet field
which has a very large VEV . This requires a
sector of "ultra-weak" couplings , where . Ultra-weak couplings are technically naturally small
due to a custodial shift symmetry of in the
limit. The singlet field has properties similar to a pseudo-dilaton.
We engineer explicit breaking of scale invariance in the ultra-weak sector via
a Coleman-Weinberg potential, which requires hierarchies amongst the ultra-weak
couplings.Comment: 6 page
What Happened to the Soviet Superpower’s Nuclear Arsenal? Clues for the Nuclear Security Summit
Twenty years ago Russia and fourteen other newly-independent states emerged from the ruins of the Soviet empire, many as nations for the first time in history. As is typical in the aftermath of the collapse of an empire, this was followed by a period of chaos, confusion, and corruption. As the saying went at the time, “everything is for sale.” At that same moment, as the Soviet state imploded, 35,000 nuclear weapons remained at thousands of sites across a vast Eurasian landmass that stretched across eleven time zones. Today, fourteen of the fifteen successor states to the Soviet Union are nuclear weapons-free. When the U.S.S.R. disappeared, 3,200 strategic nuclear warheads remained in Ukraine, Kazakhstan, and Belarus, most of them atop intercontinental ballistic missiles (ICBMs) that stood on alert, ready to be fired at targets in the U.S. Today, every one of the nuclear weapons in Ukraine, Kazakhstan, and Belarus has been deactivated and returned to Russia, where they were dismantled and the nuclear material in the warheads blended down to produce fuel for civilian reactors. Strategic nuclear weapons are nuclear warheads aimed at an adversary’s nuclear weapons, cities and military infrastructure. Typically, they are large in yield and heavy. Of greater interest to terrorists, however, were the former U.S.S.R’s 22,000 tactical nuclear weapons with smaller yields and shorter ranges. These were designed primarily for battlefield use, with some small enough to fit into a duffel bag. Today, all of these have also been returned to Russia, leaving zero nuclear weapons in any other state of the former Soviet Union. Former Czech president Vaclav Havel observed about the rush of events in the 1990s: “things have changed so fast we have not yet taken time to be astonished.” Perhaps the most astonishing fact about the past twenty years is something that did not happen. Despite the risk realistically estimated by former Secretary of Defense Dick Cheney in 3 What Happened to the Soviet Superpower's Nuclear Arsenal? Clues for the Nuclear Security Summit December 1991, two decades have passed without the discovery of a single nuclear weapon outside Russia. This paper will address the question: how did this happen? Looking ahead, it will consider what clues we can extract from the success in denuclearizing fourteen post-Soviet states that can inform our non-proliferation and nuclear security efforts in the future. These clues may inform leaders of the U.S., Russia, and other responsible nations attending the Seoul Nuclear Security Summit on March 26-27, 2012. The paper will conclude with specific recommendations, some exceedingly ambitious that world leaders could follow to build on the Seoul summit’s achievements against nuclear terrorism in the period before the next summit in 2014. One of these would be to establish a Global Alliance Against Nuclear Terrorism
What Does it Take to Make Discovery a Success?: A Survey of Discovery Tool Adoption, Instruction, and Evaluation Among Academic Libraries
Discovery tools have been widely adopted by academic libraries, yet little information exists that connects common practices regarding discovery tool implementation, maintenance, assessment, and staffing with conventions for research and instruction. The authors surveyed heads of reference and instruction departments in research and land-grant university libraries. The survey results revealed common practices with discovery tools among academic libraries. This study also draws connections between operational, instructional, and assessment practices and perceptions that participants have of the success of their discovery tool. Participants who indicated successful implementation of their discovery tool hailed from institutions that made significant commitments to the operations, maintenance, and acceptance of their discovery tool. Participants who indicated an unsuccessful implementation, or who were unsure about the success of their implementation, did not make lasting commitments to the technical maintenance, operations, and acceptance of their discovery tool
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