14,867 research outputs found
Opthalmic Teaching Problems: The Ayes Have It
The problems associated with the teaching of ophthalmology to medical students in today\u27s university setting are by no means unique to ophthalmology. However, these problems are more severe in small departments such as ophthalmology and are more disruptive to the teaching process than similar problems in larger departments. The purpose of this paper is to identify some of the more important teaching problems and propose solutions to them
Buckling of a growing tissue and the emergence of two-dimensional patterns
The process of biological growth and the associated generation of residual stress has previously been considered as a driving mechanism for tissue buckling and pattern selection in numerous areas of biology. Here, we develop a two-dimensional thin plate theory to simulate the growth of cultured intestinal epithelial cells on a deformable substrate, with the goal of elucidating how a tissue engineer might best recreate the regular array of invaginations (crypts of Lieberkühn) found in the wall of the mammalian intestine. We extend the standard von Kármán equations to incorporate inhomogeneity in the plate’s mechanical properties and surface stresses applied to the substrate by cell proliferation. We determine numerically the configurations of a homogeneous plate under uniform cell growth, and show how tethering to an underlying elastic foundation can be used to promote higher-order buckled configurations. We then examine the independent effects of localised softening of the substrate and spatial patterning of cellular growth, demonstrating that (within a two-dimensional framework, and contrary to the predictions of one-dimensional models) growth patterning constitutes a more viable mechanism for control of crypt distribution than does material inhomogeneity
Method and apparatus for making a heat insulating and ablative structure Patent
Method and apparatus for fabrication of heat insulating and ablative reentry structur
Summary Jurisdiction in Bankruptcy: Katchen v. Landy and Questions Left Unanswered
This article deals with a complex and conceptually difficult phase of bankruptcy law. It is not written for the beginner, for it does not contain all the background material necessary to effectuate a full understanding of the area. But it is extremely objective, and it exhaustively treats the relevant appellate court decisions. For the informed reader, therefore, it is both thought-provoking and an invaluable research tool
Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations.
PublishedJournal ArticleHumans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species.Environment AgencyWest Country Rivers TrustUniversity of Exete
A Comparison Between Administrative Leadership in Higher Education and Change-Oriented Leadership in Banks
Organizational environments continually change. Organizations that do not meet the demands for change do not survive. The required changes differ for banks versus universities, suggesting that leaders in each type of organization need to use unique styles to adapt to their unique environments. The purpose of this quantitative research study was to test a contingency theory of leadership that leaders of banks are change-oriented, whereas leaders of higher educational institutions are administrative in their style. The research questions dealt with differences in the uncertainty of internal operations and the external environment of banks versus universities, and the leadership style most appropriate for each type of organization. The research method was a cross-sectional, correlational, field study, with data collected by means of a tested, reliable, and valid standardized survey instrument. From the target population of 2,400 potential participants from three banks and three universities, 203 respondents completed an online survey. A series of t-tests confirmed most of the alternative hypotheses. Banks encountered a higher level of internal and external uncertainty and adopted more change-oriented leadership styles than universities. However, a hypothesis test failed to confirm the claim that administrative leadership style is more effective for universities. Findings of the study offer insights to university leaders about the importance of change-oriented leadership styles, which have the potential to engage staff more directly in the strategic changes required for organizational survival and success, thereby bringing about a higher level of individual, organizational, and social change
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