Kastra: Architecture and Culture in the Aegean Archipelago

Final version of Kastra: Architecture and Culture in the Aegean Archipelago, published Summer 2018. “Kastra: Architecture and Culture in the Aegean Archipelago,” is a sequel to “The Aegean Crucible: Tracing Vernacular Architecture in Post-Byzantine Centuries,” published in 2004. “The Aegean Crucible” focused on the vernacular architecture of the Aegean archipelago, while “Kastra” focuses on the collective fortification, a building type vital to survival in the region, during the thirteenth-to- eighteenth-century period. “Kastra” was also written on the conviction that what we identify today as the vernacular architecture of the Aegean islands emerged from the building of Kastra, the medieval collective fortifications of the Aegean archipelago. “Kastra” is a book about architecture and culture, written by an architect and addressed to the general public rather than to specialists. Observations and “notes” in the form of color slides taken during repeated visits to the region form the basic skeleton of the book, which is also enriched by the helicopter-based photographs of Nikos Daniilidis. Includes bibliographical references, index and gazeteer. Contents: Doges, Knights, Pashas and Pirates. The Aegean Archipelago. The Vernacular Response: Collective Fortifications. The Formal response: Detached Fortification Walls. The Hybrid Response: Sharing Lessons. Constantine (Dinos) E. Michaelides, FAIA, is emeritus dean and professor of the School of Architecture at Washington University in St. Louis. Born in Athens, he received an architecture diploma from the National Technical University in 1952 and earned an M.Arch. from Harvard University, Graduate School of Design in 1957.https://openscholarship.wustl.edu/books/1041/thumbnail.jp

Ordering of small particles in one-dimensional coherent structures by time-periodic flows

Small particles transported by a fluid medium do not necessarily have to follow the flow. We show that for a wide class of time-periodic incompressible flows inertial particles have a tendency to spontaneously align in one-dimensional dynamic coherent structures. This effect may take place for particles so small that often they would be expected to behave as passive tracers and be used in PIV measurement technique. We link the particle tendency to form one-dimensional structures to the nonlinear phenomenon of phase locking. We propose that this general mechanism is, in particular, responsible for the enigmatic formation of the `particle accumulation structures' discovered experimentally in thermocapillary flows more than a decade ago and unexplained until now

Can aerosols be trapped in open flows?

The fate of aerosols in open flows is relevant in a variety of physical contexts. Previous results are consistent with the assumption that such finite-size particles always escape in open chaotic advection. Here we show that a different behavior is possible. We analyze the dynamics of aerosols both in the absence and presence of gravitational effects, and both when the dynamics of the fluid particles is hyperbolic and nonhyperbolic. Permanent trapping of aerosols much heavier than the advecting fluid is shown to occur in all these cases. This phenomenon is determined by the occurrence of multiple vortices in the flow and is predicted to happen for realistic particle-fluid density ratios.Comment: Animation available at http://www.pks.mpg.de/~rdvilela/leapfrogging.htm

Semantic annotation in ubiquitous healthcare skills-based learning environments

This paper describes initial work on developing a semantic annotation system for the augmentation of skills-based learning for Healthcare. Scenario driven skills-based learning takes place in an augmented hospital ward simulation involving a patient simulator known as SimMan. The semantic annotation software enables real-time annotations of these simulations for debriefing of the students, student self study and better analysis of the learning approaches of mentors. A description of the developed system is provided with initial findings and future directions for the work.<br/

Benchmarking the performance of Density Functional Theory and Point Charge Force Fields in their Description of sI Methane Hydrate against Diffusion Monte Carlo

High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation functionals and all-atom point charge force fields is evaluated. Our results show that none of the exchange-correlation functionals tested are sufficient to describe both the energetics and the structure of methane hydrate accurately, whilst the point charge force fields perform badly in their description of the cohesive energy but fair well for the dissociation energetics. By comparing to ice Ih, we show that a good prediction of the volume and cohesive energies for the hydrate relies primarily on an accurate description of the hydrogen bonded water framework, but that to correctly predict stability of the hydrate with respect to dissociation to ice Ih and methane gas, accuracy in the water-methane interaction is also required. Our results highlight the difficulty that density functional theory faces in describing both the hydrogen bonded water framework and the dispersion bound methane.Comment: 8 pages, 4 figures, 1 table. Minor typos corrected and clarification added in Method

A machine learning potential for hexagonal boron nitride applied to thermally and mechanically induced rippling

We introduce an interatomic potential for hexagonal boron nitride (hBN) based on the Gaussian approximation potential (GAP) machine learning methodology. The potential is based on a training set of configurations collected from density functional theory (DFT) simulations and is capable of treating bulk and multilayer hBN as well as nanotubes of arbitrary chirality. The developed force field faithfully reproduces the potential energy surface predicted by DFT while improving the efficiency by several orders of magnitude. We test our potential by comparing formation energies, geometrical properties, phonon dispersion spectra, and mechanical properties with respect to benchmark DFT calculations and experiments. In addition, we use our model and a recently developed graphene-GAP to analyze and compare thermally and mechanically induced rippling in large scale two-dimensional (2D) hBN and graphene. Both materials show almost identical scaling behavior with an exponent of η ≈ 0.85 for the height fluctuations agreeing well with the theory of flexible membranes. On the basis of its lower resistance to bending, however, hBN experiences slightly larger out-of-plane deviations both at zero and finite applied external strain. Upon compression, a phase transition from incoherent ripple motion to soliton-ripples is observed for both materials. Our potential is freely available online at [http://www.libatoms.org]

Unilateral congenital non-syndromic retinal vessel dilation and tortuosity

Purpose: To present a case of atypical unilateral developmental retinal vascular anomaly. Observations: A 10-year-old girl presented to her paediatrician after an absent red reflex was noted in a photograph. She had right anisometropic amblyopia and right iris heterochromia, but was otherwise healthy, with no visual complaints. Fundus examination revealed abnormal right retinal vasculature in keeping with an arteriovenous malformation (AVM). OCTA performed at age 16, showed large aberrant veins in the right eye, whereas OCTA B-Scans showed that the same eye had significantly higher retinal blood perfusion than the unaffected eye. Conclusions and Importance: OCTA is a valuable, non-invasive emerging method of evaluating patients with AVMs, with this patient having a unique unilateral presentation of a developmental anomaly, without evidence of progression or other vessel malformation. OCTA allowed assessment of flow between the affected and non-affected eye, quantifying the greater blood perfusion in the affected eye due to the AVM

Joubert syndrome diagnosed renally late

Joubert syndrome is a genetically heterogeneous multisystem disorder typically diagnosed in childhood. Nephronophthisis is the most common renal pathology in Joubert syndrome, and renal failure usually occurs in childhood or in young adults. We report a 61-year-old female diagnosed with AHI1-related oculorenal Joubert syndrome, who presented initially with decline in renal function in her 50s. Our report describes exceptionally late presentation of renal disease in Joubert syndrome and highlights the importance of continued renal function monitoring in older adults with Joubert syndrome