3,141 research outputs found
Instantiated Recoupling in Principals\u27 Enactment of Teacher Evaluations: Emotion Work and New Forms of Ceremonial Conformity in Educational Institutions
As accountability policies have proliferated and evolved in a number of organizational fields, recent scholarship in organizational sociology has paid close attention to the ways that accountability has forced tight coupling in a variety of organizations. Fewer recent studies examine efforts at ceremonial conformity that organizations may use to buffer internal practices from institutional pressures, or how organizations and their actors might attempt to engage in ceremonial conformity under newer accountability regimes. In this article, we examine how school principals enact state-mandated teacher evaluation policies with their teachers. To manage teachers\u27 stress caused by the evaluations, we find that principals often allow, and at times enable, teachers to put on a “dog and pony show” during formal evaluations, a performance that aligns with district instructional policies but deviates from their common everyday practices. We argue that this is a novel form of ceremonial conformity that we call instantiated recoupling
Electronic Commerce Strategy in the UK Electricty Industry: The Case of Electric Co and Dataflow Software
This paper analyses the strategic business and IT response of Electric Co, a large electricity company, to deregulation and increased competition in the UK electricity industry. In common with deregulation in other markets such as North America and Australia, the UK regulator has specified strict regulations on how power generators, distribution and supply companies should interact with each other, and with business and consumer customers. In order to compete effectively Electric Co has implemented a novel dataflow solution that enables it to connect diverse internal systems to the external marketplace. An overview of changes in the market is related to the business and IT strategies of Electric Co. The link between the high-level business strategy and the actual use of IT architecture and systems is the design and management of the business processes that dictate how information is shared throughout the supply chain. The implementation of the regulator’s business process framework has been achieved through a novel use of a business process management solution. The major benefits are shown to be increased business flexibility. An outline of the broader implications of the research is given, in particular how developments in technical standards and business process management are related to communication theory and electronic markets
The Fading Radio Emission from SN 1961V: Evidence for a Type II Peculiar Supernova?
Using the Very Large Array (VLA), we have detected radio emission from the
site of SN 1961V in the Sc galaxy NGC 1058. With a peak flux density of 0.063
+/- 0.008 mJy/beam at 6 cm and 0.147 +/- 0.026 mJy/beam at 18 cm, the source is
non-thermal, with a spectral index of -0.79 +/- 0.23. Within errors, this
spectral index is the same value reported for previous VLA observations taken
in 1984 and 1986. The radio emission at both wavelengths has decayed since the
mid 1980's observations with power-law indices of beta(20cm) = -0.69 +/- 0.23
and beta(6cm) = -1.75 +/- 0.16. We discuss the radio properties of this source
and compare them with those of Type II radio supernovae and luminous blue
variables.Comment: 19 pages, 3 figures; To appear in the Astronomical Journa
Niches for Species, a multi-species model to guide woodland management: An example based on Scotland's native woodlands
Designating and managing areas with the aim of protecting biodiversity requires information on species distributions and habitat associations, but a lack of reliable occurrence records for rare and threatened species precludes robust empirical modelling. Managers of Scotland’s native woodlands are obliged to consider 208 protected species, which each have their own, narrow niche requirements. To support decision-making, we developed Niches for Species (N4S), a model that uses expert knowledge to predict the potential occurrence of 179 woodland protected species representing a range of taxa: mammals, birds, invertebrates, fungi, bryophytes, lichens and vascular plants. Few existing knowledge-based models have attempted to include so many species. We collated knowledge to define each species’ suitable habitat according to a hierarchical habitat classification: woodland type, stand structure and microhabitat. Various spatial environmental datasets were used singly or in combination to classify and map Scotland’s native woodlands accordingly, thus allowing predictive mapping of each species’ potential niche. We illustrate how the outputs can inform individual species management, or can be summarised across species and regions to provide an indicator of woodland biodiversity potential for landscape scale decisions. We tested the model for ten species using available occurrence records. Although concordance between predicted and observed distributions was indicated for nine of these species, this relationship was statistically significant in only five cases. We discuss the difficulties in reliably testing predictions when the records available for rare species are typically low in number, patchy and biased, and suggest future model improvements. Finally, we demonstrate how using N4S to synthesise complex, multi-species information into an easily digestible format can help policy makers and practitioners consider large numbers of species and their conservation needs
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Sex-independent senescence in a cooperatively breeding mammal.
Researchers studying mammals have frequently interpreted earlier or faster rates of ageing in males as resulting from polygyny and the associated higher costs of reproductive competition. Yet, few studies conducted on wild populations have compared sex-specific senescence trajectories outside of polygynous species, making it difficult to make generalized inferences on the role of reproductive competition in driving senescence, particularly when other differences between males and females might also contribute to sex-specific changes in performance across lifespan. Here, we examine age-related variation in body mass, reproductive output and survival in dominant male and female meerkats, Suricata suricatta. Meerkats are socially monogamous cooperative breeders where a single dominant pair virtually monopolizes reproduction in each group and subordinate group members help to rear offspring produced by breeders. In contrast to many polygynous societies, we find that neither the onset nor the rate of senescence in body mass or reproductive output shows clear differences between males and females. Both sexes also display similar patterns of age-related survival across lifespan, but unlike most wild vertebrates, survival senescence (increases in annual mortality with rising age) was absent in dominants of both sexes, and as a result, the fitness costs of senescence were entirely attributable to declines in reproductive output from mid- to late-life. We suggest that the potential for intrasexual competition to increase rates of senescence in females-who are hormonally masculinized and frequently aggressive-is offset by their ability to maintain longer tenures of dominance than males, and that these processes when combined lead to similar patterns of senescence in both sexes. Our results stress the need to consider the form and intensity of sexual competition as well as other sex-specific features of life history when investigating the operation of senescence in wild populations
Pronghorn Habitat Suitability in the Texas Panhandle
Habitat quality is an important factor that can greatly affect wildlife populations. Pronghorn (Antilocapra americana) habitat in the Texas Panhandle, USA has been lost through growth of human settlements and agricultural lands. We determined the most pertinent environmental variables affecting habitat selection using multiple methods, including a search of peer-reviewed literature, expert opinion ranking, and habitat suitability modeling. We determined quality and extent of pronghorn habitat in the Texas Panhandle using the MAXENT modeling environment to build a presence-only habitat suitability model based on global positioning system (GPS) locations collected via aerial surveys. Our habitat suitability model indicated that woodlands, agricultural land, and summer precipitation had the greatest contributions to the overall model. Areas with greatest habitat suitability are associated with high pronghorn population densities, particularly in the northwestern corner of the Panhandle. This probabilistic model may serve as a useful tool for pronghorn conservation primarily because it provides insight into what factors are most predictive of their presence, which areas are most suitable for pronghorn, and as a simple, replicable process to identify and evaluate pronghorn habitat
The Nature of SN 1961V
The nature of SN 1961V has been uncertain. Its peculiar optical light curve
and slow expansion velocity are similar to those of super-outbursts of luminous
blue variables (LBVs), but its nonthermal radio spectral index and declining
radio luminosity are consistent with decades-old supernovae (SNe). We have
obtained Hubble Space Telescope STIS images and spectra of the stars in the
vicinity of SN 1961V, and find Object 7 identified by Filippenko et al. to be
the closest to the optical and radio positions of SN 1961V. Object 7 is the
only point source detected in our STIS spectra and only its H-alpha emission is
detected; it cannot be the SN or its remnant because of the absence of
forbidden lines. While the H-alpha line profile of Object 7 is remarkably
similar to that of eta Car, the blue color (similar to an A2Ib supergiant) and
lack of appreciable variability are unlike known post-outburst LBVs. We have
also obtained Very Long Baseline Array (VLBA) observations of SN 1961V at 18
cm. The non-detection of SN 1961V places a lower limit on the size of the
radio-emitting region, 7.6 mas or 0.34 pc, which implies an average expansion
velocity in excess of 4,400 km/s, much higher than the optical expansion
velocity measured in 1961. We conclude the following: (1) A SN occurred in the
vicinity of SN 1961V a few decades ago. (2) If the SN 1961V light maximum
originates from a giant eruption of a massive star, Object 7 is the most
probable candidate for the survivor, but its blue color and lack of significant
variability are different from a post-outburst eta Car. (3) The radio SN and
Object 7 could be physically associated with each other through a binary
system. (4) Object 7 needs to be monitored to determine its nature and
relationship to SN 1961V.Comment: 16 pages, 3 figures, accepted by the Astronomical Journal for the
2004 May issu
Ultracompact dwarfs in the Perseus Cluster:UCD formation via tidal stripping
We present the results of a Keck/DEIMOS survey of Ultra Compact Dwarfs (UCDs)
in the Perseus Cluster core. We confirm cluster membership for 14 UCDs, with
radial velocities ~5300 km s. Two of these confirmed Perseus UCDs have
extremely blue colours ( mag), reside in star forming filaments
surrounding NGC 1275, and have likely formed as massive star clusters in the
last ~100 Myr. We also measure a central velocity dispersion of a third, UCD13
( km s), the most extended UCD in our sample. We
determine it to have radius pc, a dynamical mass of ( M, and a metallicity [Z/H] dex. UCD13 and the cluster's central galaxy, NGC 1275,
have a projected separation of 30 kpc and a radial velocity difference of ~20
km s. Based on its size, red colour, internal velocity dispersion,
dynamical mass, metallicity and proximity to NGC 1275, we argue that UCD13 is
likely the remnant nucleus of a tidally stripped dE, with this progenitor dE
having mag and mass M.Comment: 9 pages, 5 figures, accepted for publication in MNRA
A practical scheme for quantum computation with any two-qubit entangling gate
Which gates are universal for quantum computation? Although it is well known
that certain gates on two-level quantum systems (qubits), such as the
controlled-not (CNOT), are universal when assisted by arbitrary one-qubit
gates, it has only recently become clear precisely what class of two-qubit
gates is universal in this sense. Here we present an elementary proof that any
entangling two-qubit gate is universal for quantum computation, when assisted
by one-qubit gates. A proof of this important result for systems of arbitrary
finite dimension has been provided by J. L. and R. Brylinski
[arXiv:quant-ph/0108062, 2001]; however, their proof relies upon a long
argument using advanced mathematics. In contrast, our proof provides a simple
constructive procedure which is close to optimal and experimentally practical
[C. M. Dawson and A. Gilchrist, online implementation of the procedure
described herein (2002), http://www.physics.uq.edu.au/gqc/].Comment: 3 pages, online implementation of procedure described can be found at
http://www.physics.uq.edu.au/gqc
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