1,268 research outputs found
Seismic Analysis as a Tool in the Design of Two Earth Dams
Two dynamic analysis studies of embankment dams are described. One dam is 43m high on alluvium, the other is 140m high on a rock foundation in a highly seismic area. The main emphasis is on the practical nature of the analytical methods and their value as design tools. The earthquake design features of both projects are described and the closing paragraphs attempt to draw attention to the main points to be considered when running an earthquake analysis of earth dams
A previously undescribed variant of the confluence of sinuses
An 8-year-old female with a history of chronic headaches and uncertain papilloedema was found to have a variant of the posterior intracranial dural venous sinuses on magnetic resonance imaging assessment of the brain. Magnetic resonance venography included in the imaging revealed a circular formation of the confluence of sinuses and absent right-sided transverse sinus. The confluence of sinuses is a highly variable structure; however, to the authors’ knowledge, a circular confluence of sinuses variant has not been reported in the literature
Turnover and activity-dependent transcriptional control of NompC in the Drosophila ear.
Across their lives, biological sensors maintain near-constant functional outputs despite countless exogenous and endogenous perturbations. This sensory homeostasis is the product of multiple dynamic equilibria, the breakdown of which contributes to age-related decline. The mechanisms of homeostatic maintenance, however, are still poorly understood. The ears of vertebrates and insects are characterized by exquisite sensitivities but also by marked functional vulnerabilities. Being under the permanent load of thermal and acoustic noise, auditory transducer channels exemplify the homeostatic challenge. We show that (1) NompC-dependent mechanotransducers in the ear of the fruit fly Drosophila melanogaster undergo continual replacement with estimated turnover times of 9.1Â hr; (2) a de novo synthesis of NompC can restore transducer function in the adult ears of congenitally hearing-impaired flies; (3) key components of the auditory transduction chain, including NompC, are under activity-dependent transcriptional control, likely forming a transducer-operated mechanosensory gain control system that extends beyond hearing organs
Rewriting Logic Semantics of a Plan Execution Language
The Plan Execution Interchange Language (PLEXIL) is a synchronous language
developed by NASA to support autonomous spacecraft operations. In this paper,
we propose a rewriting logic semantics of PLEXIL in Maude, a high-performance
logical engine. The rewriting logic semantics is by itself a formal interpreter
of the language and can be used as a semantic benchmark for the implementation
of PLEXIL executives. The implementation in Maude has the additional benefit of
making available to PLEXIL designers and developers all the formal analysis and
verification tools provided by Maude. The formalization of the PLEXIL semantics
in rewriting logic poses an interesting challenge due to the synchronous nature
of the language and the prioritized rules defining its semantics. To overcome
this difficulty, we propose a general procedure for simulating synchronous set
relations in rewriting logic that is sound and, for deterministic relations,
complete. We also report on two issues at the design level of the original
PLEXIL semantics that were identified with the help of the executable
specification in Maude
Vegetative growth and water use characterization of a maize introgression library
Previous work showed that a maize introgression library (IL) derived from the cross between Gasp\ue9 Flint (an early flowering Canadian landrace) and B73 (the reference maize line) segregated for phenology as well for seminal root architecture (SRA) traits.
In this experiment, the IL was evaluated in the high-throughput phenotyping platform PhenoArch (INRA, Montpellier
The partial skeleton StW 431 from Sterkfontein – Is it time to rethink the Plio-Pleistocene hominin diversity in South Africa?
The discovery of the nearly complete Plio-Pleistocene skeleton StW 573 Australopithecus prometheus from Sterkfontein Member 2, South Africa, has intensified debates as to whether Sterkfontein Member 4 contains a hominin species other than Australopithecus africanus. For example, it has recently been suggested that the partial skeleton StW 431 should be removed from the A. africanus hypodigm and be placed into A. prometheus. Here we re-evaluate this latter proposition, using published information and new comparative data. Although both StW 573 and StW 431 are apparently comparable in their arboreal (i.e., climbing) and bipedal
adaptations, they also show significant morphological differences. Surprisingly, StW 431 cannot be unequivocally aligned with either StW 573 or other hominins from Sterkfontein commonly attributed to A. africanus (nor with Paranthropus robustus and Australopithecus sediba). This finding, together with considerations about the recent dating of Plio-Pleistocene hominin-bearing sites in South Africa and palaeoecological/palaeoclimatic conditions, raises questions whether it is justified to subsume hominins from Taung, Makapansgat and Sterkfontein (and Gladysvale) within a single taxon. Given the wealth of fossil material and analytical techniques now available, we call for a re-evaluation of the taxonomy of South African Plio-Pleistocene hominins. Such an endeavour should however go beyond the current (narrow) focus on establishing an A. africanus-A. prometheus dichotomy.
Macho, Gabriele A.
Fornai, Cinzia
Tardieu, Christine
Hopley, Philip
Haeusler, Martin
Toussaint, Miche
Theory of Cylindrical Tubules and Helical Ribbons of Chiral Lipid Membranes
We present a general theory for the equilibrium structure of cylindrical
tubules and helical ribbons of chiral lipid membranes. This theory is based on
a continuum elastic free energy that permits variations in the direction of
molecular tilt and in the curvature of the membrane. The theory shows that the
formation of tubules and helical ribbons is driven by the chirality of the
membrane. Tubules have a first-order transition from a uniform state to a
helically modulated state, with periodic stripes in the tilt direction and
ripples in the curvature. Helical ribbons can be stable structures, or they can
be unstable intermediate states in the formation of tubules.Comment: 43 pages, including 12 postscript figures, uses REVTeX 3.0 and
epsf.st
SpikeletFCN: Counting Spikelets from Infield Wheat Crop Images Using Fully Convolutional Networks
Currently, crop management through automatic monitoring is growing momentum, but presents various challenges. One key challenge is to quantify yield traits from images captured automatically. Wheat is one of the three major crops in the world with a total demand expected to exceed 850 million tons by 2050. In this paper we attempt estimation of wheat spikelets from high-definition RGB infield images using a fully convolutional model. We propose also the use of transfer learning and segmentation to improve the model. We report cross validated Mean Absolute Error (MAE) and Mean Square Error (MSE) of 53.0, 71.2 respectively on 15 real field images. We produce visualisations which show the good fit of our model to the task. We also concluded that both transfer learning and segmentation lead to a very positive impact for CNN-based models, reducing error by up to 89%, when extracting key traits such as wheat spikelet counts
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