388 research outputs found
Decorrelation of User Defined Function Invocations in Queries
Queries containing user-defined functions (UDFs) are widely used, since they allow queries to be written using a mix of imperative language constructs and SQL, thereby increasing the expressive power of SQL; further, they encourage modularity, and make queries easier to understand. However, not much attention has been paid to their optimization, except for simple UDFs without imperative constructs. Queries invoking UDFs with imperative constructs are executed using iterative invocation of the UDFs, leading to poor performance, especially if the UDF contains queries. Such poor execution has been a major deterrent to the wider usage of complex UDFs
Angiosomes of medial cord of brachial plexus
This anatomical study analyzed the neurovascular relationship of the brachial plexus. Ten formalized specimens of brachial plexuses were examined after injection of lead oxide in to the subclavian artery. The vascular, anatomical features of the brachial plexus were documented .The specimens were analyzed by dissection method, subjected for microscopic study. The vascular supply was markedly rich, often with true anastomotic channels found within the nerves. There was much variation in supply, depending on the branching pattern of subclavian artery
Case report on laurence moon biedyl syndrome
Laurence moon Biedyl syndrome is a rare autosomal recessive condition with a wide spectrum of clinical features. The accepted major criteria for diagnosis include retinal dystrophy, obesity, Polydactyly, male hypogonadism, mental retardation and renal dysfunction. We have presented a 36 year old male patient exhibiting characteristic features of Laurence moon Biedyl syndrome and then the literature is reviewed
Multi-State RNA Design with Geometric Multi-Graph Neural Networks
Computational RNA design has broad applications across synthetic biology and
therapeutic development. Fundamental to the diverse biological functions of RNA
is its conformational flexibility, enabling single sequences to adopt a variety
of distinct 3D states. Currently, computational biomolecule design tasks are
often posed as inverse problems, where sequences are designed based on adopting
a single desired structural conformation. In this work, we propose gRNAde, a
geometric RNA design pipeline that operates on sets of 3D RNA backbone
structures to explicitly account for and reflect RNA conformational diversity
in its designs. We demonstrate the utility of gRNAde for improving native
sequence recovery over single-state approaches on a new large-scale 3D RNA
design dataset, especially for multi-state and structurally diverse RNAs. Our
code is available at https://github.com/chaitjo/geometric-rna-desig
Threading light through dynamic complex media
The scattering of light impacts sensing and communication technologies
throughout the electromagnetic spectrum. Overcoming the effects of time-varying
scattering media is particularly challenging. In this article we introduce a
new way to control the propagation of light through dynamic complex media. Our
strategy is based on the observation that many dynamic scattering systems
exhibit a range of decorrelation times -- meaning that over a given timescale,
some parts of the medium may essentially remain static. We experimentally
demonstrate a suite of new techniques to identify and guide light through these
networks of static channels -- threading optical fields around multiple dynamic
pockets hidden at unknown locations inside opaque media. We first show how a
single stable light field propagating through a partially dynamic medium can be
found by optimising the wavefront of the incident field. Next, we demonstrate
how this procedure can be accelerated by 2 orders of magnitude using a
physically realised form of adjoint gradient descent optimisation. Finally, we
describe how the search for stable light modes can be posed as an eigenvalue
problem: we introduce a new optical matrix operator, the time-averaged
transmission matrix, and show how it reveals a basis of
fluctuation-eigenchannels that can be used for stable beam shaping through
time-varying media. These methods rely only on external camera measurements
recording scattered light, require no prior knowledge about the medium, and are
independent of the rate at which dynamic regions move. Our work has potential
future applications to a wide variety of technologies reliant on general wave
phenomena subject to dynamic conditions, from optics to acoustics.Comment: 16 pages, 6 figures. This updated version includes supplementary
informatio
Benchmarking Generated Poses: How Rational is Structure-based Drug Design with Generative Models?
Deep generative models for structure-based drug design (SBDD), where molecule
generation is conditioned on a 3D protein pocket, have received considerable
interest in recent years. These methods offer the promise of higher-quality
molecule generation by explicitly modelling the 3D interaction between a
potential drug and a protein receptor. However, previous work has primarily
focused on the quality of the generated molecules themselves, with limited
evaluation of the 3D molecule \emph{poses} that these methods produce, with
most work simply discarding the generated pose and only reporting a "corrected"
pose after redocking with traditional methods. Little is known about whether
generated molecules satisfy known physical constraints for binding and the
extent to which redocking alters the generated interactions. We introduce
PoseCheck, an extensive analysis of multiple state-of-the-art methods and find
that generated molecules have significantly more physical violations and fewer
key interactions compared to baselines, calling into question the implicit
assumption that providing rich 3D structure information improves molecule
complementarity. We make recommendations for future research tackling
identified failure modes and hope our benchmark can serve as a springboard for
future SBDD generative modelling work to have a real-world impact
Direct and Simultaneous Observation of Ultrafast Electron and Hole Dynamics in Germanium
Understanding excited carrier dynamics in semiconductors is crucial for the
development of photovoltaics and efficient photonic devices. However,
overlapping spectral features in optical/NIR pump-probe spectroscopy often
render assignments of separate electron and hole carrier dynamics ambiguous.
Here, ultrafast electron and hole dynamics in germanium nanocrystalline thin
films are directly and simultaneously observed by attosecond transient
absorption spectroscopy (ATAS) in the extreme ultraviolet at the germanium
M_{4,5}-edge (~30 eV). We decompose the ATAS spectra into contributions of
electronic state blocking and photo-induced band shifts at a carrier density of
8*10^{20}cm^{-3}. Separate electron and hole relaxation times are observed as a
function of hot carrier energies. A first order electron and hole decay of ~1
ps suggests a Shockley-Read-Hall recombination mechanism. The simultaneous
observation of electrons and holes with ATAS paves the way for investigating
few to sub-femtosecond dynamics of both holes and electrons in complex
semiconductor materials and across junctions.Comment: Includes Supplementary Informatio
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