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Highly frustrated antiferromagnets composed of magnetic rare-earth moments are currently attracting much experimental and theoretical interest. Rare-earth ions generally have small exchange interactions and large magnetic moments. This makes it necessary to understand in detail the role of long-range magnetic dipole-dipole interactions in these systems, in particular, in the context of spin-spin correlations that develop in the paramagnetic phase, but are often unable to condense into a conventional long-range magnetic-ordered phase. This scenario is most dramatically emphasized in the frustrated pyrochlore antiferromagnet material Tb2Ti2O7, which does not order down to 50 mK despite an antiferromagnetic Curie-Weiss temperature TCW∼-20 K. In this paper we report results from mean-field theory calculations of the paramagnetic elastic neutron scattering in highly frustrated magnetic systems with long-range dipole-dipole interactions, focusing on the Tb2Ti2O7 system. Modeling Tb 2Ti2O7 as an antiferromagnetic 〈111〉 Ising pyrochlore, we find that the mean-field paramagnetic scattering is inconsistent with the experimentally observed results. Through simple symmetry arguments we demonstrate that the observed paramagnetic correlations in Tb 2Ti2O7 are precluded from being generated by any spin Hamiltonian that considers only Ising spins, but are qualitatively consistent with Heisenberg-like moments. Explicit calculations of the paramagnetic scattering pattern for both 〈111〉 Ising and Heisenberg models, which include finite single-ion anisotropy, support these claims. We offer suggestions for reconciling the need to restore spin isotropy with the Ising-like structure suggested by the single-ion properties of Tb3+.

Dy2Ti2O7 has been advanced as an ideal spin ice material. We present a neutron scattering investigation of a single-crystal sample of 162Dy2Ti2O 7. The scattering intensity has been mapped in zero applied field in the h,h,l and h,k,0 planes of reciprocal space at temperatures between 0.05 and 20 K. The measured diffuse scattering has been compared with that predicted by the dipolar spin ice model. The comparison is good, except at the Brillouin-zone boundaries where extra scattering appears in the experimental data. It is concluded that the dipolar spin ice model provides a successful basis for understanding Dy2Ti2O7, but that there are issues which remain to be clarified.

Until the nineteen hundreds, people with disabilities did not receive formal educational services in Kenya. This paper discusses available educational services for individuals with visual impairments in terms of their forms, materials provided, and educational placements. Areas of most progress are discussed along with obstacles that stand in the way of efficient services for this population. This paper contributes to the rather scarce literature on educational services for students with disabilities in developing countries.

This study investigates audit effectiveness (or the lack thereof) of audit opinions issued by auditors preceding company bankruptcies. Data from all 26 bankrupt UK financial institutions were used to determine if auditor appropriately issued opinions other than unqualified, as signs of non-going concern determine any differences in audit-opinion effectiveness between international and domestic audit firms. Results show that unqualified opinions issued was significantly higher than other opinions prior to bankruptcy. While international audit firms were less likely to issue unqualified opinions than their domestic counterparts no firm issued adverse or disclaimer of opinions in any given year, despite serious warning signals from return on assets (ROA), return on equity (ROE) and current ratios. © 2004 Inderscience Enterprises Ltd.

Jaltomata andersonii (Solanaceae), here named, is distributed on the western slope of the Andes, in the Departments of Ancash and Lima, Peru, from 2300 to 3400 m of elevation. This species differs from others of the genus by having an unarticulated axis connecting the flower to the plant where all others have both a peduncle and a pedicel. The following combination of features also characterize this species: the hairs of leaves and axes are gland-tipped; the petiole is no longer than 1 cm; the flowers are solitary; the corolla is broadly crateriform-rotate, purple, and up to 3.7 cm in diameter; and the filaments are extremely villous at their bases.

Two experiments (N = 147 and N = 90) explored the use of multiple independent lineups to identify a target seen live. In Experiment 1, simultaneous face, body, and sequential voice lineups were used. In Experiment 2, sequential face, body, voice, and clothing lineups were used. Both studies demonstrated that multiple identifications (by the same witness) from independent lineups of different features are highly diagnostic of suspect guilt (G. L. Wells & R. C. L. Lindsay, 1980). The number of suspect and foil selections from multiple independent lineups provides a powerful method of calibrating the accuracy of eyewitness identification. Implications for use of current methods are discussed.

In this paper the strategy for the eliminative reduction of the alethic modalities suggested by John Venn is outlined and it is shown to anticipate certain related contemporary empiricistic and nominalistic projects. Venn attempted to reduce the alethic modalities to probabilities, and thus suggested a promising solution to the nagging issue of the inclusion of modal statements in empiricistic philosophical systems. However, despite the promise that this suggestion held for laying the ‘ghost of modality’ to rest, this general approach, tempered modal eliminativism, is shown to be inadequate for that task. © 2004 Taylor & Francis Group, LLC.

Until recently, the rhynchonelliform (articulated) brachiopod fauna from the Brazilian continental shelf (western South Atlantic) was represented only by the endemic species Bouchardia rosea (Mawe), reported from coastal waters of the states of São Paulo and Rio de Janeiro. The present study, based on samples from coastal (<30m), shelf, and continental slope waters (99-485 m), documents the South Atlantic brachiopod fauna and shows that this fauna is more widespread, diverse, and cosmopolitan than previously thought. Based on a total of 16,177 specimens, the following brachiopods have been identified: Bouchardia rosea (Family Bouchardiidae), Platidia anomioides (Family Platidiidae), Argyrotheca cf. cuneata (Family Megathyrididae), and Terebratulina sp. (Family Cancellothyrididae). In coastal settings, the fauna is overwhelmingly dominated by Bouchardia rosea. Rare juvenile (<2 mm) specimens of Argyrotheca cf. cuneata were also found at two shallow-water sites. In shelf settings (100-200 m), the fauna is more diverse and includes Bouchardia rosea, Terebratulina sp., Argyrotheca cf. cuneata, and Platidia anomioides. Notably, Bouchardia rosea was found in waters as deep as 485 m, extending the known bathymetric range of this genus. Also, the record of this brachiopod in waters of the state of Paraná is the southernmost known occurrence of this species. The genera Platidia and Terebratulina are documented here for the first time for the western South Atlantic. The Brazilian brachiopod fauna shares similarities with those from the Atlantic and Indian shelves of southern Africa, and from the Antarctic, Caribbean and Mediterranean waters. The present-day brachiopods of the western South Atlantic are much more cosmopolitan than previously thought and their Cenozoic palaeobiogeographic history has to be reconsidered from that perspective. © The Paleontological Association.

The current study examined the number and content of possible selves in the lives of adult women over the course of a five-month interval. Based on previous empirical studies of possible selves, a variety of hypotheses were proposed that addressed cohort differences in possible selves, continuity and change in possible selves, and predicting changes in possible selves over time with ego-identity. The results indicated mixed support for the hypotheses, but basically replicated previous research findings on possible selves. The findings are discussed in terms of how they extend both descriptive and predictive knowledge of possible selves. © 2006 by Nova Science Publishers, Inc. All rights reserved.

We documented active nests of the Northern Goshawk (Accipiter gentilis) at 16 different areas in Connecticut from 1997-1999. A total of 176 prey individuals were identified from remains found under goshawk nests and prey-plucking posts. Birds represented the dominant component of diets (70.5%) with a lower contribution from mammals (29.5%). Overall, Connecticut goshawk diets were dominated by sciurids and Ruffed Grouse (Bonasa umbellus). Productivity calculated from 15 known nesting attempts totaled 32 young for an average of 2.13 young per nesting attempt (range 1-4 young). Goshawks nested in large tracts of mature forests with high levels of canopy cover (82%). The nest site topography was consistent with previous studies finding that goshawks avoid southern slopes. Tree densities in the larger size classes and basal area were characteristic for mature forest. Goshawks constructed their nests in large diameter trees, which averaged 41.7 cm in diameter at breast height. Patch size of contiguous forests surrounding goshawk nests revealed a very high mean of 324.5 ha, thus suggesting that large forest patch size may be important for nesting by this forest interior species. Analysis of 202 ha circles centered on each nest revealed that total forest cover averaged 156.1 ha, which was comprised of 65.2 ha for conifer forest, 75.6 ha for deciduous forest, and 17.4 ha for mixed forest. Overall, the post-fledgling family areas for these nests were dominated by forest cover (>75%). Our results suggest that goshawks usually prefer isolation and little human disturbance at the nest site, but some exceptions were noted. Given the highly fragmented and urbanized landscape of Connecticut, we suggest that goshawk management should focus on providing large tracts of mature forest at least 300 ha in extent.

Evidence suggests that the Northern Goshawk (Accipiter gentilis) was once extirpated in the New York-New Jersey Highlands, but has recolonized the Highlands in the 1960s and 1970s following a dramatic reforestation in the 20th century. The reforestation produced large tracts of contiguous mature forest, which appear to be a primary habitat requirement of this species. Most goshawk nests in the Highlands were found deep in remote forest areas where nest sites are typically distant from human habitation and paved roads. Nest trees were almost always built in co-dominant or dominant trees of the stand, but were seldom built in the largest tree of the nesting stand. Canopy cover is very high (90%) and shrub cover is often reduced or nearly devoid (28.3%) at goshawk nest sites. Ruffed Grouse (Bonasa umbellus) appears to be the most common prey, but other predominant bird species in diets of Highlands goshawks included the Blue Jay (Cyanocitta cristata), Mourning Dove (Zenaida macroura), Rock Dove (Columba livia), and blackbirds. Sciurids, including eastern chipmunks (Tamias striatus), red squirrel (Tamiasciurus hudsonicus), and gray squirrel (Sciurus carolinensis) were also important components of goshawk diets from the Northeast. Highlands goshawks had a mean prey weight of 365.8 g, with bird prey averaging 332.3 g and mammal prey averaging 442.9 g. In the Highlands, productivity calculated from 36 nesting attempts averaged 1.4 young per nest, lower than found in two Connecticut studies (1.75 and 2.13). Although the goshawk is generally considered to be a permanent resident, dozens of northeastern hawk migration observation stations reveal a small, but distinct, fall migration during non-invasion years. Breeding bird atlas data confirm that the goshawk is rare in New Jersey, moderately rare in Pennsylvania (mostly northern), and numerous in New York. Various factors impacting Highlands goshawks are discussed including interspecific competition, lack of reserves, timber harvesting, tree diseases, and human disturbance factors.

This book describes the WTO from its post-WWII beginnings in the General Agreement on Tariffs and Trade through a series of negotiated enhancements of these agreements. It describes the WTO's origins, structure, and growing pains as it has had to face challenges from within and without. © Kevin Buterbaugh, 2007. All rights reserved.

For the TREC 2007 conference, the CRM114 team considered three non-Bayesian methods of spam filtration in the CRM114 framework - an SVM based on the "hyperspace" feature==document paradigm, a bit-entropy matcher, and substring compression based on LZ77. As a calibration yardstick, we used the well-tested and widely used CRM114 OSB markov random field system (basically unchanged since 2003). The results show that the SVM has a spam-filtering accuracy of about a factor of two to three better accuracy than the OSB system, that substring compression is somewhat more accurate than OSB, and that bit entropy is somewhat less accurate for the TREC 2007 test sets.

The electrical properties of the mismatched interface between InP and GaP have been investigatedted. High resolution transmission electron microscopy (HRTEM) image shows the presence of strain relieving, 90° misfit dislocations at the InP/GaP interface. Electrochemical capacitance voltage (ECV) profiling indicates the presence of a high-density sheet of carriers at the interface. AFM image shows a pretty good InP epitaxial layer with surface roughness of 2.48 nm has been obtained. A model based on Fermi-level pinning in InP at the interface by misfit dislocations is proposed to account for the observed electrical behavior.

Discussions of diagnostic tools that gauge students' conceptual understanding permeate the literature. Many instructors report their class' normalized gain to characterize the change in scores from pre-test to post-test. We describe a new procedure for characterizing these changes. This procedure, which we call the normalized change, c, involves the ratio of the gain to the maximum possible gain or the loss to the maximum possible loss. We also advocate reporting the average of a class' normalized changes and utilizing a particular statistical and graphical approach for comparing average c values. © 2007 American Association of Physics Teachers.