2,630 research outputs found

    The political economy of opencast mining in Scotland and the north east of England

    Get PDF
    This is an interdisciplinary, descriptive, empirical study and analysis of the use of opencast mining in a complex process of commercialisation of the coal industry, its impact upon the environment and communities. Much of the initial research was undertaken during a series of public inquiries into opencast mining which provided the wealth of material contained in the thesis. The thesis advanced here is that the State has regulated the supply of coal through positive discrimination for opencast coal in the operation of the planning system and by arbitrary financial regulation of British Coal operations. The argument presented is that despite contrasting approaches and political processes in Scotland and North East England, opencast coal production has been used as a common facilitator towards the commercialisation of the coal industry. Descriptive analysis is given of the changing strategic use of opencast mining across the decades, from its early commercial development and the policy of dual control to its intensive application to assist the coal industry meet government financial and operational directives. The expansion of opencast mining can be attributed to changes in the political economy of the 1970's, the application of the private sector ethos of input-output ratios and management control, the unprecedented (mis)use of secondary planning legislation and the continued use of narrow accountancy procedures. Despite the denials of British Coal, in the North East of England opencast coal output has supplanted deep mined capacity and has been maximised to the limits of the Power Generators* specifications for burning coal to maximise profit and provide a "bank' of assets to attract private investment. The strategy in Scotland shows opencast mining holding the markets during radical reconstruction of the industry, hibernating' investment to make the industry attractive for the private sector. Both strategies have been set within a general "sweetening' operation of the coal industry. The work assesses the changing policy process of environmental planning, planning law and the public inquiry process in relation to opencast coalmining. Two major attitude surveys in Scotland and North East England cover the social context of environmental planning policy, each confirm the marginalisation of the public to decisions made in opencast development. Certain themes define the scope of the thesis: The Stateā€™s approach to energy policy and planning policy. British Coal's economic "management' of coal production, as well as the attitudes of the public, public planning officials, British Coal and the National Union of Mineworkers in Scotland and North East England. Scrutiny of the market for coal and British Coal's claims for the need for opencast coal are given full coverage in light of the effects from the expansion of opencast mining on employment, the environment and people. Overall the thesis challenges accepted thinking on economic and planning policy aspects and technical requirements of opencast coal production in relation to deep mined coal

    Synchronization and Control in Intrinsic and Designed Computation: An Information-Theoretic Analysis of Competing Models of Stochastic Computation

    Full text link
    We adapt tools from information theory to analyze how an observer comes to synchronize with the hidden states of a finitary, stationary stochastic process. We show that synchronization is determined by both the process's internal organization and by an observer's model of it. We analyze these components using the convergence of state-block and block-state entropies, comparing them to the previously known convergence properties of the Shannon block entropy. Along the way, we introduce a hierarchy of information quantifiers as derivatives and integrals of these entropies, which parallels a similar hierarchy introduced for block entropy. We also draw out the duality between synchronization properties and a process's controllability. The tools lead to a new classification of a process's alternative representations in terms of minimality, synchronizability, and unifilarity.Comment: 25 pages, 13 figures, 1 tabl

    Diffusion due to the Beam-Beam Interaction and Fluctuating Fields in Hadron Colliders

    Full text link
    Random fluctuations in the tune, beam offsets and beam size in the presence of the beam-beam interaction are shown to lead to significant particle diffusion and emittance growth in hadron colliders. We find that far from resonances high frequency noise causes the most diffusion while near resonances low frequency noise is responsible for the large emittance growth observed. Comparison of different fluctuations shows that offset fluctuations between the beams causes the largest diffusion for particles in the beam core.Comment: 5 pages, 3 postscript figure

    Maximum likelihood estimation of reviewers' acumen in central review setting: categorical data

    Get PDF
    Successfully evaluating pathologists' acumen could be very useful in improving the concordance of their calls on histopathologic variables. We are proposing a new method to estimate the reviewers' acumen based on their histopathologic calls. The previously proposed method includes redundant parameters that are not identifiable and results are incorrect. The new method is more parsimonious and through extensive simulation studies, we show that the new method relies less on the initial values and converges to the true parameters. The result of the anesthetist data set by the new method is more convincing

    Charge-coupled devices with fast timing for astrophysics and space physics research

    Get PDF
    A charge coupled device is under development with fast timing capability (15 millisecond full frame readout, 30 microsecond resolution for measuring the time of individual pixel hits). The fast timing CCD will be used in conjunction with a CsI microfiber array or segmented scintillator matrix detector to detect x rays and gamma rays with submillimeter position resolution. The initial application will be in conjunction with a coded aperture hard x ray/gamma ray astronomy instrument. We describe the concept and the readout architecture of the device

    Many Roads to Synchrony: Natural Time Scales and Their Algorithms

    Full text link
    We consider two important time scales---the Markov and cryptic orders---that monitor how an observer synchronizes to a finitary stochastic process. We show how to compute these orders exactly and that they are most efficiently calculated from the epsilon-machine, a process's minimal unifilar model. Surprisingly, though the Markov order is a basic concept from stochastic process theory, it is not a probabilistic property of a process. Rather, it is a topological property and, moreover, it is not computable from any finite-state model other than the epsilon-machine. Via an exhaustive survey, we close by demonstrating that infinite Markov and infinite cryptic orders are a dominant feature in the space of finite-memory processes. We draw out the roles played in statistical mechanical spin systems by these two complementary length scales.Comment: 17 pages, 16 figures: http://cse.ucdavis.edu/~cmg/compmech/pubs/kro.htm. Santa Fe Institute Working Paper 10-11-02

    Metabolism of profenofos to 4-bromo-2-chlorophenol, a specific and sensitive exposure biomarker.

    Get PDF
    Profenofos is a direct acting phosphorothioate organophosphorus (OP) pesticide capable of inhibiting Ī²-esterases such as acetylcholinesterase, butyrylcholinesterase, and carboxylesterase. Profenofos is known to be detoxified to the biologically inactive metabolite, 4-bromo-2-chlorophenol (BCP); however, limited data are available regarding the use of urinary BCP as an exposure biomarker in humans. A pilot study conducted in Egyptian agriculture workers, demonstrated that urinary BCP levels prior to application (3.3-30.0 Ī¼g/g creatinine) were elevated to 34.5-3,566 Ī¼g/g creatinine during the time workers were applying profenofos to cotton fields. Subsequently, the in vitro enzymatic formation of BCP was examined using pooled human liver microsomes and recombinant human cytochrome P-450s (CYPs) incubated with profenofos. Of the nine human CYPs studied, only CYPs 3A4, 2B6, and 2C19 were able to metabolize profenofos to BCP. Kinetic studies indicated that CYP 2C19 has the lowest Km, 0.516 Ī¼M followed by 2B6 (Km=1.02 Ī¼M) and 3A4 (Km=18.9Ī¼M). The Vmax for BCP formation was 47.9, 25.1, and 19.2 nmol/min/nmol CYP for CYP2B6, 2C19, and 3A4, respectively. Intrinsic clearance (Vmax/Km) values of 48.8, 46.9, and 1.02 ml/min/nmol CYP 2C19, 2B6, and 3A4, respectively, indicate that CYP2C19 and CYP2B6 are primarily responsible for the detoxification of profenofos. These findings support the use of urinary BCP as a biomarker of exposure to profenofos in humans and suggest polymorphisms in CYP 2C19 and CYP 2B6 as potential biomarkers of susceptibility

    Balloon-borne coded aperture telescope for arc-minute angular resolution at hard x-ray energies

    Get PDF
    We are working on the development of a new balloon-borne telescope, MARGIE (minute-of-arc resolution gamma ray imaging experiment). It will be a coded aperture telescope designed to image hard x-rays (in various configurations) over the 20 - 600 keV range with an angular resolution approaching one arc minute. MARGIE will use one (or both) of two different detection plane technologies, each of which is capable of providing event locations with sub-mm accuracies. One such technology involves the use of cadmium zinc telluride (CZT) strip detectors. We have successfully completed a series of laboratory measurements using a prototype CZT detector with 375 micron pitch. Spatial location accuracies of better than 375 microns have been demonstrated. A second type of detection plane would be based on CsI microfiber arrays coupled to a large area silicon CCD readout array. This approach would provide spatial resolutions comparable to that of the CZT prototype. In one possible configuration, the coded mask would be 0.5 mm thick tungsten, with 0.5 mm pixels at a distance of 1.5 m from the central detector giving an angular resolution of 1 arc-minute and a fully coded field of view of 12 degrees. We review the capabilities of the MARGIE telescope and report on the status of our development efforts and our plans for a first balloon flight

    Prognostic value and functional consequences of cell cycle inhibitor p27Kip1 loss in medulloblastoma

    Get PDF
    BACKGROUND: The cyclin-dependent kinase inhibitor p27(Kip1) functions during normal cerebellar development and has demonstrated tumor suppressor functions in mouse models of medulloblastoma. Because P27 loss is associated with increased proliferation, we assessed whether P27 absence in surgical medulloblastoma specimens correlated with response to therapy in pediatric patients enrolled in two large studies. Additionally, we examined the functional consequence of p27(Kip1) loss in the SmoA1 medulloblastoma model to distinguish whether p27(Kip1) reduces tumor initiation or slows tumor progression. FINDINGS: Analysis of 87 well-characterized patient samples identified a threshold of P27 staining at which significant P27 loss correlated with poor patient outcome. The same criteria, applied to a second test set of tissues from 141 patients showed no difference in survival between patients with minimal P27 staining and others, suggesting that P27 levels alone are not a sufficient prognostic indicator for identifying standard-risk patients that may fail standard therapy. These findings were in contrast to prior experiments completed using a mouse medulloblastoma model. Analysis of cerebellar tumor incidence in compound mutant mice carrying the activated Smoothened (SmoA1) allele that were heterozygous or nullizygous for p27(Kip1) revealed that p27(Kip1) loss did not alter the frequency of tumor initiation. Tumors haploinsufficient or nullizygous for p27(Kip1) were, however, more invasive and displayed a higher proliferative index, suggesting p27(Kip1) loss may contribute to SmoA1 medulloblastoma progression. CONCLUSIONS: These studies revealed P27 loss affects medulloblastoma progression rather than initiation and that this putative biomarker should not be used for stratifying children with medulloblastoma to risk-based therapeutic regimens

    Type Ibc supernovae in disturbed galaxies: evidence for a top-heavy IMF

    Full text link
    We compare the radial locations of 178 core-collapse supernovae to the R-band and H alpha light distributions of their host galaxies. When the galaxies are split into `disturbed' and `undisturbed' categories, a striking difference emerges. The disturbed galaxies have a central excess of core-collapse supernovae, and this excess is almost completely dominated by supernovae of types Ib, Ic and Ib/c, whereas type II supernovae dominate in all other environments. The difference cannot easily be explained by metallicity or extinction effects, and thus we propose that this is direct evidence for a stellar initial mass function that is strongly weighted towards high mass stars, specifically in the central regions of disturbed galaxies.Comment: 22 pages, 5 figures, accepted for publication in Ap
    • ā€¦
    corecore