David Summers' Real Spaces: World Art History and the Rise of Western Modernism remains one the most ambitious and compelling attempts to develop a new analytic framework for art-historical analysis ...across geographic and temporal boundaries. Despite this accomplishment, since its publication nearly 15 years ago the book has continued to face the criticism of being a problematically Western project. But what are the philosophical ideas on which Real Spaces is based? And how is it that these general ideas are troublingly Western, rather than being more generally human or cross-cultural? A prominent reading by James Elkins of Real Spaces has positioned its claims in relation to the philosophical project of Martin Heidegger, as Summers' terminology does have Heideggerean overtones. Building on Elkins' reading, in this essay I argue that Summers' book is more accurately understood as a form of neo-Pragmatism. To substantiate this claim, I emphasize some known parallels between Heidegger's project and that of Pragmatism in general as well as a variety of similarities between Real Spaces and the vocabularies of Richard Rorty and Charles Sanders Peirce that Summers himself has noted. While such an argument may merely seem to replace one Western philosophical understanding of Real Spaces for another, doing so also allows the book to be understood in relation to some of neo-Pragmatism's most compelling moral or ethical claims and thereby to more adequately answer the criticism that Summers' alternative art history is just another precariously Western project.
Purpose
Purpose - Virtual environments (VEs) that represent real spaces (RSs) give people who are blind the opportunity to build a cognitive map in advance that they will be able to use when arriving ...at the RS.
Design/methodology/approach
In this research study Nintendo Wii based technology was used for exploring VEs via the Wiici application. The Wiimote allows the user to interact with VEs by simulating walking and scanning the space.
Findings
By getting haptic and auditory feedback the user learned to explore new spaces. We examined the participants' abilities to explore new simple and complex places, construct a cognitive map, and perform orientation tasks in the RS.
Originality/value
To our knowledge, this finding presents the first virtual environment for people who are blind that allow the participants to scan the environment and by this to construct map model spatial representations.
This article is a continuation of a paper of the first author V. Ferenczi, Uniqueness of complex structure and real hereditarily indecomposable Banach spaces, Adv. Math. 213 (1) (2007) 462–488 about ...complex structures on real Banach spaces. We define a notion of even infinite-dimensional real Banach space, and prove that there exist even spaces, including HI or unconditional examples from V. Ferenczi, Uniqueness of complex structure and real hereditarily indecomposable Banach spaces, Adv. Math. 213 (1) (2007) 462–488 and
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examples due to Plebanek G. Plebanek, A construction of a Banach space
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with few operators, Topology Appl. 143 (2004) 217–239. We extend results of V. Ferenczi, Uniqueness of complex structure and real hereditarily indecomposable Banach spaces, Adv. Math. 213 (1) (2007) 462–488 relating the set of complex structures up to isomorphism on a real space to a group associated to inessential operators on that space, and give characterizations of even spaces in terms of this group. We also generalize results of V. Ferenczi, Uniqueness of complex structure and real hereditarily indecomposable Banach spaces, Adv. Math. 213 (1) (2007) 462–488 about totally incomparable complex structures to essentially incomparable complex structures, while showing that the complex version of a space defined by S. Argyros and A. Manoussakis S. Argyros, A. Manoussakis, An indecomposable and unconditionally saturated Banach space, Studia Math. 159 (1) (2003) 1–32 provides examples of essentially incomparable complex structures which are not totally incomparable.
The commonly used validation metrics for the local agreement of a structure model with the observed electron density, namely the real‐space R (RSR) and the real‐space correlation coefficient (RSCC), ...are reviewed. It is argued that the primary goal of all validation techniques is to verify the accuracy of the model, since precision is an inherent property of the crystal and the data. It is demonstrated that the principal weakness of both of the above metrics is their inability to distinguish the accuracy of the model from its precision. Furthermore, neither of these metrics in their usual implementation indicate the statistical significance of the result. The statistical properties of electron‐density maps are reviewed and an improved alternative likelihood‐based metric is suggested. This leads naturally to a χ2 significance test of the difference density using the real‐space difference density Z score (RSZD). This is a metric purely of the local model accuracy, as required for effective model validation and structure optimization by practising crystallographers prior to submission of a structure model to the PDB. A new real‐space observed density Z score (RSZO) is also proposed; this is a metric purely of the model precision, as a substitute for other precision metrics such as the B factor.
This article describes the implementation of real‐space refinement in the phenix.real_space_refine program from the PHENIX suite. The use of a simplified refinement target function enables very fast ...calculation, which in turn makes it possible to identify optimal data‐restraint weights as part of routine refinements with little runtime cost. Refinement of atomic models against low‐resolution data benefits from the inclusion of as much additional information as is available. In addition to standard restraints on covalent geometry, phenix.real_space_refine makes use of extra information such as secondary‐structure and rotamer‐specific restraints, as well as restraints or constraints on internal molecular symmetry. The re‐refinement of 385 cryo‐EM‐derived models available in the Protein Data Bank at resolutions of 6 Å or better shows significant improvement of the models and of the fit of these models to the target maps.
A description is provided of the implementation of real‐space refinement in the phenix.real_space_refine program from the PHENIX suite and its application to the re‐refinement of cryo‐EM‐derived models.
Real space in cryo‐EM: the future is local Palmer, Colin M.; Aylett, Christopher H. S.
Acta crystallographica. Section D, Structural biology,
February 2022, Letnik:
78, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Cryo‐EM images have extremely low signal‐to‐noise levels because biological macromolecules are highly radiation‐sensitive, requiring low‐dose imaging, and because the molecules are poor in contrast. ...Confident recovery of the signal requires the averaging of many images, the iterative optimization of parameters and the introduction of much prior information. Poor parameter estimates, overfitting and variations in signal strength and resolution across the resulting reconstructions remain frequent issues. Because biological samples are real‐space phenomena, exhibiting local variations, real‐space measures can be both more reliable and more appropriate than Fourier‐space measures. Real‐space measures can be calculated separately over each differing region of an image or volume. Real‐space filters can be applied according to the local need. Powerful prior information, not available in Fourier space, can be introduced in real space. Priors can be applied in real space in ways that Fourier space precludes. The treatment of biological phenomena remains highly dependent on spatial frequency, however, which would normally be handled in Fourier space. We believe that measures and filters based around real‐space operations on extracted frequency bands, i.e. a series of band‐pass filtered real‐space volumes, and over real‐space densities of striding (sequentially increasing or decreasing) resolution through Fourier space are the best way to address this and will perform better than global Fourier‐space‐based approaches. Future developments in image processing within the field are generally expected to be based on a mixture of both rationally designed and deep‐learning approaches, and to incorporate novel prior information from developments such as AlphaFold. Regardless of approach, it is clear that `locality', through real‐space measures, filters and processing, will become central to image processing.
A perspective is provided on the future development of real‐space methods in cryo‐EM.
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