3,044 research outputs found
Towards a query language for annotation graphs
The multidimensional, heterogeneous, and temporal nature of speech databases
raises interesting challenges for representation and query. Recently,
annotation graphs have been proposed as a general-purpose representational
framework for speech databases. Typical queries on annotation graphs require
path expressions similar to those used in semistructured query languages.
However, the underlying model is rather different from the customary graph
models for semistructured data: the graph is acyclic and unrooted, and both
temporal and inclusion relationships are important. We develop a query language
and describe optimization techniques for an underlying relational
representation.Comment: 8 pages, 10 figure
Management education and the ethical mindset: Responsibility to whom and for what?
Paper presented at the European Business Ethics Network (UK) Conference, Ethics in Crisis: a call for alternatives, April 7-9, 2010 at Queen Mary, University of London. Final version published by Springer in Journal of Business Ethics. Original title: Management education and the ethical mindset:
Responsibility to whom and for what? Available online at http://www.springer.com/This paper offers an analysis of leadership responsibility associated with differing models of the firm. Following a critique of the classical economic and conventional stakeholder theories of the firm, we proposes an interactive stakeholder theory that better facilitates the kind of ethical responsibility demanded by twenty-first century challenges. Our analysis also leads us to conclude that leadership education and development is in need of urgent reform. The first part of the paper focuses on what it means to lead responsibly, and argues that leading is essentially the practice of responsibility. The second part of the paper challenges standard assumptions about the ‘business of business’, while the third section examines in more depth how leadership education might be configured as a preparation for the enactment of responsible leadership. KEYWORDS: responsible leadership, ethics, leadership education, mindsets, stakeholder theor
Alpha-fetoprotein detection of hepatocellular carcinoma leads to a standardized analysis of dynamic AFP to improve screening based detection
Detection of hepatocellular carcinoma (HCC) through screening can improve outcomes. However, HCC surveillance remains costly, cumbersome and suboptimal. We tested whether and how serum Alpha-Fetoprotein (AFP) should be used in HCC surveillance. Record linkage, dedicated pathways for management and AFP data-storage identified i) consecutive highly characterised cases of HCC diagnosed in 2009–14 and ii) a cohort of ongoing HCC-free patients undergoing regular HCC surveillance from 2009. These two well-defined Scottish patient cohorts enabled us to test the utility of AFP surveillance. Of 304 cases of HCC diagnosed over 6 years, 42% (129) were identified by a dedicated HCC surveillance programme. Of these 129, 47% (61) had a detectable lesion first identified by screening ultrasound (US) but 38% (49) were prompted by elevated AFP. Despite pre-HCC diagnosis AFP >20kU/L being associated with poor outcome, ‘AFP-detected’ tumours were offered potentially curative management as frequently as ‘US-detected’ HCCs; and had comparable survival. Linearity of serial log10-transformed AFPs in HCC cases and in the screening ‘HCC-free’ cohort (n = 1509) provided indicators of high-risk AFP behaviour in HCC cases. An algorithm was devised in static mode, then tested dynamically. A case/control series in hepatitis C related disease demonstrated highly significant detection (p<1.72*10−5) of patients at high risk of developing HCC. These data support the use of AFP in HCC surveillance. We show proof-of-principle that an automated and further refine-able algorithmic interpretation of AFP can identify patients at higher risk of HCC. This approach could provide a cost-effective, user-friendly and much needed addition to US surveillance
The impact of broadband in schools: summary report
Summary of the report, which reviews evidence for the impact of broadband in English schools, exploring; variations in provision in level of broadband connectivity. Links between the level of broadband activity and nationally accessible performance data; aspects of broadband connectivity and the school environment that contribute to better outcomes for pupils and teachers; academic and motivational benefits associated with educational uses of this technology
Neotectonic modeling of the Ibero-Maghrebian region
15 páginas, 12 figuras.Thin-shell finite element techniques have been applied to model the neotectonics of the Ibero-Maghrebian region, in the westernmost Mediterranean. This region is characterized by a complex seismotectonic pattern and moderate seismic activity associated with the convergence between Africa and Eurasia. We compare two end-member models using different fault networks. Model predictions, including anelastic strain rates, vertically integrated stresses and velocity fields, are compared to the seismicity map and to data on directions of maximum horizontal compression. Best results are obtained assuming a low fault friction coefficient (0.05) and when the Betics and Rif are modeled as parts of the same arc-shaped chain. The highest predicted fault slip rates are in the Tell mountains. Farther to the west, fault slip is more homogeneously distributed over the Betic-Rif chain, Gulf of Cadiz, and Alboran Sea, indicating a diffuse geometry of the plate boundary in this area. The areas of highest predicted strain rates coincide with the most seismically active regions, located in northern Algeria and northeastern Morocco. Our best model also reproduces a major change of the stress regime, from thrusting in the east (Tell mountains) to predominantly strike-slip and normal faulting in the west (Betic-Rif chain and Alboran Sea). The Alboran basin is shown to be undergoing significant internal transpression and therefore cannot be considered as a rigid microplate. The western part of the Alboran Sea and surrounding areas are being extruded to the WNW with respect to Iberia.Spanish research programs Ramón y Cajal,
BTE2002-02462, REN2000-0777-C02-01/RIES, DGESIC PB97-1267-C03-01, and a grant from the Foundation Jaime del Amo (University
Complutense of Madrid) have partially supported this work.Peer reviewe
Networks Underpinning Symbiosis Revealed Through Cross-Species eQTL Mapping.
Organisms engage in extensive cross-species molecular dialog, yet the underlying molecular actors are known for only a few interactions. Many techniques have been designed to uncover genes involved in signaling between organisms. Typically, these focus on only one of the partners. We developed an expression quantitative trait locus (eQTL) mapping-based approach to identify cause-and-effect relationships between genes from two partners engaged in an interspecific interaction. We demonstrated the approach by assaying expression of 98 isogenic plants (Medicago truncatula), each inoculated with a genetically distinct line of the diploid parasitic nematode Meloidogyne hapla With this design, systematic differences in gene expression across host plants could be mapped to genetic polymorphisms of their infecting parasites. The effects of parasite genotypes on plant gene expression were often substantial, with up to 90-fold (P = 3.2 × 10-52) changes in expression levels caused by individual parasite loci. Mapped loci included a number of pleiotropic sites, including one 87-kb parasite locus that modulated expression of >60 host genes. The 213 host genes identified were substantially enriched for transcription factors. We distilled higher-order connections between polymorphisms and genes from both species via network inference. To replicate our results and test whether effects were conserved across a broader host range, we performed a confirmatory experiment using M. hapla-infected tomato. This revealed that homologous genes were similarly affected. Finally, to validate the broader utility of cross-species eQTL mapping, we applied the strategy to data from a Salmonella infection study, successfully identifying polymorphisms in the human genome affecting bacterial expression
Searching for the Kuhnian moment : the Black-Scholes-Merton formula and the evolution of modern finance theory
The Black-Scholes-Merton formula has been put to widespread use by options traders because it provides a means of calculating the theoretically 'correct' price of stock options. Traders can therefore see whether the market price of stock options undervalues or overvalues them compared with their hypothetical Black-Scholes-Merton price, before choosing to buy or sell options accordingly. As a consequence of this close relationship between options pricing theory and options pricing practice, a strong performativity loop was activated, whereby market prices quickly converged on the hypothetical Black-Scholes-Merton prices following the dissemination of the formula. The theory has therefore had significant real-world effects, but how should we characterize the initial instinct to derive the theory from a philosophy of science perspective? The two books under review suggest that a Kuhnian reading of the advancement of scientific knowledge might well be the most appropriate. But, on closer inspection, it becomes clear that the publication of the Black-Scholes-Merton formula should not be seen as a Kuhnian moment with paradigm-shaping attributes. It is shown that, at most, the formula acts as an important exemplar which, via its use in the training of options pricing theorists and options pricing practitioners, reinforces the entrenchment of finance theory within the orthodox economics worldview
Correlation between Compact Radio Quasars and Ultra-High Energy Cosmic Rays
Some proposals to account for the highest energy cosmic rays predict that
they should point to their sources. We study the five highest energy events
(E>10^20 eV) and find they are all aligned with compact, radio-loud quasars.
The probability that these alignments are coincidental is 0.005, given the
accuracy of the position measurements and the rarity of such sources. The
source quasars have redshifts between 0.3 and 2.2. If the correlation pointed
out here is confirmed by further data, the primary must be a new hadron or one
produced by a novel mechanism.Comment: 8 pages, 3 tables, revtex. with some versions of latex it's necessary
to break out the tables and latex them separately using article.sty rather
than revtex.st
Ultra-High Energy Cosmic Ray Propagation in the Local Supercluster
We present detailed numerical simulations and analytical approximations of
the propagation of nucleons above 10**(19) eV in the Local Supercluster,
assuming that the ambient magnetic field is turbulent, and its strength 0.01 <
B_rms < 1 micro-Gauss. In such strong magnetic fields, protons in the low
energy part of the spectrum, 10**(19) eV < E < E_C diffuse, while the higher
energy particles, with E > E_C propagate along nearly straight lines. The
magnitude of the transition energy E_C depends mainly on the strength of the
magnetic field, the coherence length, and the distance to the source; for
B_rms=0.1 micro-Gauss, a largest eddy of length 10 Mpc, and a distance to the
source of 10 Mpc, E_C=100 EeV. Our numerical treatment substantially improves
on previous analytical approximations, as it allows to treat carefully the
transition between the two propagation regimes, as well as the effects due to
inhomogeneities expected on scales of a few Mpc. We show that a turbulent
magnetic field B_rms=0.1 micro-Gauss, close to equipartition, would allow to
reproduce exactly the observed spectrum of ultra high energy cosmic rays, up to
the highest energy observed, for a distance to the source below 10 Mpc, for the
geometry of the Local Supercluster, i.e. a sheet of thickness 10 Mpc.
Diffusion, in this case, allows to reproduce the high flux beyond the Greisen
Zatsepin Kuzmin cut-off, with a soft injection spectrum proportional to
E**(-2.4). Moreover, the large deflection angles at the highest energies
observed, typically 10 degrees for the above values, would explain why no
close-by astrophysical counterpart could be associated with these events.Comment: 17 latex pages (tightened format), 9 updated postscript figures, uses
revtex.sty and epsf.sty, extended discussion of numerical results, to appear
in Astroparticle Physic
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