440 research outputs found
The case of 'A Rhino Horn': case report and proposal for modification to the Hetsroni and Kelly classification.
Subspine impingement syndrome by definition involves a prominent antero-inferior iliac spine (AIIS) which can lead to impingement on the femoral neck thereby causing symptoms. We present the case of a 22-year-old semi-professional athlete who presented with a Type III AIIS morphology leading to subspine impingement syndrome and was managed via a mini open anterior approach. Radiological examination revealed a fairly prominent left AIIS resembling the 'horn of a rhino' extending to the trochanteric region anteriorly. A mini-anterior surgical approach was utilized for the resection of the 'rhino horn' and the rectus femoris was reattached. The patient remained asymptomatic at the one-year follow-up and had resumed weightlifting. Following this case, we propose a new classification of the type III AIIS morphology in view of the clinical presentation. The AIIS type III-Standard represents an extension from the acetabular rim to less than 1âcm (type III-S) and type III-Large, with an extension from the acetabular rim beyond 1âcm (type III-L). The type III-L will further be divided into two groups based on its relation to the ilium, type III-Lr ('rib shape') and type III-Lrh ('rhino horn')
Quality assessment of vascular access procedures for hemodialysis: A position paper of the Vascular Access Society based on the analysis of existing guidelines
Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon's experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon's specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs
Acidification and solar drying of manure-based digestate to produce improved fertilizing products
The increase in energy and fertilizer consumption makes it necessary to develop sustainable alternatives for agriculture. Anaerobic digestion and digestates appeared to be suitable options. However, untreated digestates still have high water content and can increase greenhouse gas emissions during storage and land application. In this study, manure-derived digestate and solid fraction of digestate after separation were treated with a novel solar drying technology to reduce their water content, combined with acidification to reduce the gaseous emissions. The acidified digestate and acidified solid fraction of digestate recovered more nitrogen and ammonia nitrogen than their respective non-acidified products (1.5â1.3 times for TN; 14 times for TAN). Ammonia and methane emissions were reduced up to 94% and 72% respectively, compared to the non-acidified ones, while N2O increased more than 3 times. Dried digestate and dried acidified digestate can be labeled as NPK organic fertilizer regarding the European regulation, and the dried solid fraction and the improved dried acidified solid fraction can be labeled as N or P organic fertilizer. Moreover, plant tests showed that N concentrations in fresh lettuce leaves were within the EU limit with all products in all the cases. However, zinc concentration appeared to be a limitation in some of the products as their concentration exceeded the European legal limits.This work was funded by the European Union under the Circular Agronomics project (H2020 research and innovation project NÂș.773649) and Nutry2Cycle project (H2020 research and innovation project NÂș.773682). IRTA thanks the support of the CERCA Program and the Consolidated Research Group TERRA (ref.2017SGR1292), both from the Generalitat de Catalunya. L. Morey thanks the financial support of AGAUR, of the Generalitat de Catalunya (grant reference number 2019FI_B00694). We would like to thank the help of Celia Segura Godoy and Pau Berenguer i Planas during the sampling campaigns.Peer ReviewedPostprint (published version
Acidification and solar drying of manure-based digestate to produce improved fertilizing products
The increase in energy and fertilizer consumption makes it necessary to develop sustainable alternatives for
agriculture. Anaerobic digestion and digestates appeared to be suitable options. However, untreated digestates
still have high water content and can increase greenhouse gas emissions during storage and land application. In
this study, manure-derived digestate and solid fraction of digestate after separation were treated with a novel
solar drying technology to reduce their water content, combined with acidification to reduce the gaseous
emissions. The acidified digestate and acidified solid fraction of digestate recovered more nitrogen and ammonia
nitrogen than their respective non-acidified products (1.5â1.3 times for TN; 14 times for TAN). Ammonia and
methane emissions were reduced up to 94% and 72% respectively, compared to the non-acidified ones, while
N2O increased more than 3 times. Dried digestate and dried acidified digestate can be labeled as NPK organic
fertilizer regarding the European regulation, and the dried solid fraction and the improved dried acidified solid
fraction can be labeled as N or P organic fertilizer. Moreover, plant tests showed that N concentrations in fresh
lettuce leaves were within the EU limit with all products in all the cases. However, zinc concentration appeared
to be a limitation in some of the products as their concentration exceeded the European legal limitsinfo:eu-repo/semantics/publishedVersio
Identifying Exoplanets with Deep Learning. V. Improved Light Curve Classification for TESS Full Frame Image Observations
The TESS mission produces a large amount of time series data, only a small
fraction of which contain detectable exoplanetary transit signals. Deep
learning techniques such as neural networks have proved effective at
differentiating promising astrophysical eclipsing candidates from other
phenomena such as stellar variability and systematic instrumental effects in an
efficient, unbiased and sustainable manner. This paper presents a high quality
dataset containing light curves from the Primary Mission and 1st Extended
Mission full frame images and periodic signals detected via Box Least Squares
(Kov\'acs et al. 2002; Hartman 2012). The dataset was curated using a thorough
manual review process then used to train a neural network called
Astronet-Triage-v2. On our test set, for transiting/eclipsing events we achieve
a 99.6% recall (true positives over all data with positive labels) at a
precision of 75.7% (true positives over all predicted positives). Since 90% of
our training data is from the Primary Mission, we also test our ability to
generalize on held-out 1st Extended Mission data. Here, we find an area under
the precision-recall curve of 0.965, a 4% improvement over Astronet-Triage (Yu
et al. 2019). On the TESS Object of Interest (TOI) Catalog through April 2022,
a shortlist of planets and planet candidates, Astronet-Triage-v2 is able to
recover 3577 out of 4140 TOIs, while Astronet-Triage only recovers 3349 targets
at an equal level of precision. In other words, upgrading to Astronet-Triage-v2
helps save at least 200 planet candidates from being lost. The new model is
currently used for planet candidate triage in the Quick-Look Pipeline (Huang et
al. 2020a,b; Kunimoto et al. 2021).Comment: accepted for publication in AJ. code can be found at:
https://github.com/mdanatg/Astronet-Triage and data can be found at:
https://zenodo.org/record/741157
Generation of a wave packet tailored to efficient free space excitation of a single atom
We demonstrate the generation of an optical dipole wave suitable for the
process of efficiently coupling single quanta of light and matter in free
space. We employ a parabolic mirror for the conversion of a transverse beam
mode to a focused dipole wave and show the required spatial and temporal
shaping of the mode incident onto the mirror. The results include a proof of
principle correction of the parabolic mirror's aberrations. For the application
of exciting an atom with a single photon pulse we demonstrate the creation of a
suitable temporal pulse envelope. We infer coupling strengths of 89% and
success probabilities of up to 87% for the application of exciting a single
atom for the current experimental parameters.Comment: to be published in Europ. Phys. J.
Heralded single photon absorption by a single atom
The emission and absorption of single photons by single atomic particles is a
fundamental limit of matter-light interaction, manifesting its quantum
mechanical nature. At the same time, as a controlled process it is a key
enabling tool for quantum technologies, such as quantum optical information
technology [1, 2] and quantum metrology [3, 4, 5, 6]. Controlling both emission
and absorption will allow implementing quantum networking scenarios [1, 7, 8,
9], where photonic communication of quantum information is interfaced with its
local processing in atoms. In studies of single-photon emission, recent
progress includes control of the shape, bandwidth, frequency, and polarization
of single-photon sources [10, 11, 12, 13, 14, 15, 16, 17], and the
demonstration of atom-photon entanglement [18, 19, 20]. Controlled absorption
of a single photon by a single atom is much less investigated; proposals exist
but only very preliminary steps have been taken experimentally such as
detecting the attenuation and phase shift of a weak laser beam by a single atom
[21, 22], and designing an optical system that covers a large fraction of the
full solid angle [23, 24, 25]. Here we report the interaction of single
heralded photons with a single trapped atom. We find strong correlations of the
detection of a heralding photon with a change in the quantum state of the atom
marking absorption of the quantum-correlated heralded photon. In coupling a
single absorber with a quantum light source, our experiment demonstrates
previously unexplored matter-light interaction, while opening up new avenues
towards photon-atom entanglement conversion in quantum technology.Comment: 10 pages, 4 figure
An SU(N) Mott insulator of an atomic Fermi gas realized by large-spin Pomeranchuk cooling
The Hubbard model, containing only the minimum ingredients of nearest
neighbor hopping and on-site interaction for correlated electrons, has
succeeded in accounting for diverse phenomena observed in solid-state
materials. One of the interesting extensions is to enlarge its spin symmetry to
SU(N>2), which is closely related to systems with orbital degeneracy. Here we
report a successful formation of the SU(6) symmetric Mott insulator state with
an atomic Fermi gas of ytterbium (173Yb) in a three-dimensional optical
lattice. Besides the suppression of compressibility and the existence of charge
excitation gap which characterize a Mott insulating phase, we reveal an
important difference between the cases of SU(6) and SU(2) in the achievable
temperature as the consequence of different entropy carried by an isolated
spin. This is analogous to Pomeranchuk cooling in solid 3He and will be helpful
for investigating exotic quantum phases of SU(N) Hubbard system at extremely
low temperatures.Comment: 20 pages, 6 figures, to appear in Nature Physic
Quantum Computing and Quantum Simulation with Group-II Atoms
Recent experimental progress in controlling neutral group-II atoms for
optical clocks, and in the production of degenerate gases with group-II atoms
has given rise to novel opportunities to address challenges in quantum
computing and quantum simulation. In these systems, it is possible to encode
qubits in nuclear spin states, which are decoupled from the electronic state in
the S ground state and the long-lived P metastable state on the
clock transition. This leads to quantum computing scenarios where qubits are
stored in long lived nuclear spin states, while electronic states can be
accessed independently, for cooling of the atoms, as well as manipulation and
readout of the qubits. The high nuclear spin in some fermionic isotopes also
offers opportunities for the encoding of multiple qubits on a single atom, as
well as providing an opportunity for studying many-body physics in systems with
a high spin symmetry. Here we review recent experimental and theoretical
progress in these areas, and summarise the advantages and challenges for
quantum computing and quantum simulation with group-II atoms.Comment: 11 pages, 7 figures, review for special issue of "Quantum Information
Processing" on "Quantum Information with Neutral Particles
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