4,450 research outputs found
All-optical conditional logic with a nonlinear photonic crystal nanocavity
We demonstrate tunable frequency-converted light mediated by a chi-(2)
nonlinear photonic crystal nanocavity. The wavelength-scale InP-based cavity
supports two closely-spaced localized modes near 1550 nm which are resonantly
excited by a 130 fs laser pulse. The cavity is simultaneously irradiated with a
non-resonant probe beam, giving rise to rich second-order scattering spectra
reflecting nonlinear mixing of the different resonant and non-resonant
components. In particular, we highlight the radiation at the sum frequencies of
the probe beam and the respective cavity modes. This would be a useful,
minimally-invasive monitor of the joint occupancy state of multiple cavities in
an integrated optical circuit.Comment: 4 pages, 4 figure
Viability and tissue quality of cartilage flaps from patients with femoroacetabular hip impingement: A matched-control comparison
Background: Chondrolabral damage is commonly observed in patients with cam-type femoroacetabular impingement (FAI). Chondral flap reattachment has recently been proposed as a possible preservation technique. Purpose/Hypothesis: The purpose of this study was to determine the viability and tissue quality of chondral flaps from patients with FAI at the time of arthroscopy. It was hypothesized that chondral flaps from patients with cam lesions of the hip would exhibit less viability and greater tissue degeneration than would those of a matched control group. Study Design: Cohort study; Level of evidence, 2. Methods: Patients with cam-type FAI who were treated with hip arthroscopy between 2014 and 2016 were asked to participate in this study. The cartilage lesions were localized and classified intraoperatively according to Beck classification. A chondral flap (study group) and a cartilage sample (control group) were obtained from each patient for histologic evaluation. Cellular viability and tissue quality were examined and compared in both groups. Cellular viability was determined with live/dead staining, and tissue quality was evaluated using safranin O/fast green, hematoxylin and eosin (H&E) staining, and immunohistochemistry for collagen II. Osteoarthritis Research Society International (OARSI) grading was used for quality assessment, and Image J software was used to calculate the percentage of tissue viability and Col II stain. Results: A total of 10 male patients with a mean age of 38.4 years (range, 30-55 years) were enrolled. All chondral flaps were classified as Beck grade 4. The mean cellular viability of the chondral flaps was reduced (54.6% ± 25.6%), and they were found to be degenerated (OARSI grade, 4 ± 1.27). Control samples also had reduced viability (38.8% ± 30.3%) and were degenerative (OARSI grade, 3.5 ± 1.38). There was no statistically significant intergroup difference for viability ( P = .203) or OARSI grade ( P = .645), nor was there an intragroup correlation between viability and OARSI grade ( P > .05). A significant negative correlation ( r = −0.9, P = .035) was found between OARSI grade and collagen II percentage scale in 5 selected samples. Conclusion: Despite appearing normal macroscopically, the chondral flaps from patients with cam-type FAI displayed loss of viability and tissue degeneration. In addition, control samples obtained away from the injury area also displayed cartilage damage and degeneration. Careful consideration should be taken when attempting to reattach the chondral flap. </jats:sec
Star Formation Under the Outflow: The Discovery of a Non-Thermal Jet from OMC-2 FIR 3 and its Relationship to the Deeply Embedded FIR 4 Protostar
We carried out multiwavelength (0.7-5 cm), multiepoch (1994-2015) Very Large
Array (VLA) observations toward the region enclosing the bright far-IR sources
FIR 3 (HOPS 370) and FIR 4 (HOPS 108) in OMC-2. We report the detection of 10
radio sources, seven of them identified as young stellar objects. We image a
well-collimated radio jet with a thermal free-free core (VLA 11) associated
with the Class I intermediate-mass protostar HOPS 370. The jet presents several
knots (VLA 12N, 12C, 12S) of non-thermal radio emission (likely synchrotron
from shock-accelerated relativistic electrons) at distances of ~7,500-12,500 au
from the protostar, in a region where other shock tracers have been previously
identified. These knots are moving away from the HOPS 370 protostar at ~ 100
km/s. The Class 0 protostar HOPS 108, which itself is detected as an
independent, kinematically decoupled radio source, falls in the path of these
non-thermal radio knots. These results favor the previously proposed scenario
where the formation of HOPS 108 has been triggered by the impact of the HOPS
370 outflow with a dense clump. However, HOPS 108 presents a large proper
motion velocity of ~ 30 km/s, similar to that of other runaway stars in Orion,
whose origin would be puzzling within this scenario. Alternatively, an apparent
proper motion could result because of changes in the position of the centroid
of the source due to blending with nearby extended emission, variations in the
source shape, and /or opacity effects.Comment: 16 pages, 4 figures, accepted for publication in The Astrophysical
Journa
Extended Warm Gas in the ULIRG Mrk273: Galactic Outflows and Tidal Debris
We present new HST ACS medium- and narrow-band images and long-slit, optical
(4000 - 7200A) spectra obtained using the Isaac Newton Telescope (INT) on La
Palma, of the merging system Mrk273. The HST observations sample the
[OIII]4959,5007 emission from the galaxy and the nearby continuum. The images
show that the morphologies of the extended continuum and the ionised gas
emission from the galaxy are decoupled, extending almost perpendicular to each
other. In particular, we detect for the first time a spectacular structure of
ionised gas in the form of filaments extending ~23 kpc to the east of the
nuclear region. The quiescent ionised gas kinematics at these locations
suggests that these filaments are tidal debris left over from a secondary
merger event that are illuminated by an AGN in the nuclear regions. The images
also reveal a complex morphology in the nuclear region of the galaxy for both
the continuum and the [OIII] emission. Kinematic disturbance, in the form of
broad (FWHM > 500 km s-1) and/or strongly shifted (abs(\DeltaV) >150 km s-1)
emission line components, is found at almost all locations within a radius of
~4 kpc to the east and west of the northern nucleus. We fit the profiles of all
the emission lines of different ionisation with a kinematic model using up to 3
Gaussian components. From these fits we derive diagnostic line ratios that are
used to investigate the ionisation mechanisms at the different locations in the
galaxy. We show that, in general, the line ratios are consistent with
photoionization by an AGN as the main ionisation mechanism. Finally, the
highest surface brightness [OIII] emission is found in a compact region that is
coincident with the so-called SE nuclear component. The compactness, kinematics
and emission line ratios of this component suggest that it is a separate
nucleus with its own AGN.Comment: Accepted for Publication in A&
Lifetime Bipolar Disorder comorbidity and related clinical characteristics in patients with primary Obsessive Compulsive Disorder: a report from the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS)
IntroductionBipolar disorder (BD) and obsessive compulsive disorder (OCD) are prevalent, comorbid, and disabling conditions, often characterized by early onset and chronic course. When comorbid, OCD and BD can determine a more pernicious course of illness, posing therapeutic challenges for clinicians. Available reports on prevalence and clinical characteristics of comorbidity between BD and OCD showed mixed results, likely depending on the primary diagnosis of analyzed samples.MethodsWe assessed prevalence and clinical characteristics of BD comorbidity in a large international sample of patients with primary OCD (n = 401), through the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS) snapshot database, by comparing OCD subjects with vs without BD comorbidity.ResultsAmong primary OCD patients, 6.2% showed comorbidity with BD. OCD patients with vs without BD comorbidity more frequently had a previous hospitalization (p < 0.001) and current augmentation therapies (p < 0.001). They also showed greater severity of OCD (p < 0.001), as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS).ConclusionThese findings from a large international sample indicate that approximately 1 out of 16 patients with primary OCD may additionally have BD comorbidity along with other specific clinical characteristics, including more frequent previous hospitalizations, more complex therapeutic regimens, and a greater severity of OCD. Prospective international studies are needed to confirm our findings.Peer reviewe
Universal quantum gates based on both geometric and dynamic phases in quantum dots
A large-scalable quantum computer model, whose qubits are represented by the
subspace subtended by the ground state and the single exciton state on
semiconductor quantum dots, is proposed. A universal set of quantum gates in
this system may be achieved by a mixed approach, composed of dynamic evolution
and nonadibatic geometric phase.Comment: 4 pages, to appear in Chin. Phys. Let
Non-Critical String Duals of N=1 Quiver Theories
We construct N=1 non-critical strings in four dimensions dual to strongly
coupled N=1 quiver gauge theories in the Coulomb phase, generalizing the string
duals of Argyres-Douglas points in N=2 gauge theories. They are the first
examples of superstrings vacua with an exact worldsheet description dual to
chiral N=1 theories. We identify the dual of the non-critical superstring using
a brane setup describing the field theory in the classical limit. We analyze
the spectrum of chiral operators in the strongly coupled regime and show how
worldsheet instanton effects give non-perturbative information about the gauge
theory. We also consider aspects of D-branes relevant for the holographic
duality.Comment: JHEP style; 40 pages, 3 figures; v2: minor corrections, refs added,
version to appear in JHE
Revision of the EU Green Public Procurement Criteria for Food and Catering Services
This report forms the basis to revise the existing EU Green Public Procurement (GPP) criteria for Food and Catering services. This will assist in the reduction of negative impacts of the, public procurement of these services, on the environment, human health and natural resources. The revision of EU GPP requires in-depth information about the technical and environmental performance of the service group as well as about the current procurement processes. The scientific body of evidence gathered will be cross-checked with sector experienced stakeholders, to develop consensus on how the criteria should be revised to deliver optimum environmental improvements.
This Report which will be the basis for producing the draft EU GPP criteria proposals that will be discussed in the Ad Hoc Working Group (AHWG) meetings.
Chapter 1 focuses on the definition for and scoping of Food and Catering Services to overview of the different scope and definitions and to narrow down the services in order to obtain a homogenous scope.
Chapter 2, market analysis, presents the market overview and the market structure by focusing on the contract catering market.
The environmental analysis (Chapter 3) provides a detail analysis of the main environmental hotspots for the food product categories by reviewing a number of LCA studies. Other non-LCA aspects including ethical and health consideration are also summarised. The technical analysis focus on the current schemes and labels identified as important for the revision of the current EU GPP criteria.
Chapter 4 provide improvement options, based on the best sector practices and national cases studies which could assist the revision of the EU GPP, and reduce the sectors environmental impacts, by drawing on findings from the market and technical analysis.JRC.B.5-Circular Economy and Industrial Leadershi
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