156 research outputs found
Antiresonance phase shift in strongly coupled cavity QED
We investigate phase shifts in the strong coupling regime of single-atom
cavity quantum electrodynamics (QED). On the light transmitted through the
system, we observe a phase shift associated with an antiresonance and show that
both its frequency and width depend solely on the atom, despite the strong
coupling to the cavity. This shift is optically controllable and reaches 140
degrees - the largest ever reported for a single emitter. Our result offers a
new technique for the characterization of complex integrated quantum circuits.Comment: 5 pages, 5 figure
Vessels for the future
The European research association Vessels for the Future was launched in November 2014. It has members has 59 members (as of May 2015) in 14 EU Member States. Members represent ship owners, ship yards, ship system suppliers, classification societies, research institutes, university departments and industry associations. Hence Vessels for the Future brings together a leading group of maritime stakeholders with a common interest to ensure that European maritime research has a strong and vibrant future sustaining a competitive maritime industry. This will be achieved through agreeing collaborative research and with the support of public and private financing
Continuous parametric feedback cooling of a single atom in an optical cavity
We demonstrate a new feedback algorithm to cool a single neutral atom trapped
inside a standing-wave optical cavity. The algorithm is based on parametric
modulation of the confining potential at twice the natural oscillation
frequency of the atom, in combination with fast and repetitive atomic position
measurements. The latter serve to continuously adjust the modulation phase to a
value for which parametric excitation of the atomic motion is avoided. Cooling
is limited by the measurement back action which decoheres the atomic motion
after only a few oscillations. Nonetheless, applying this feedback scheme to a
~ 5 kHz oscillation mode increases the average storage time of a single atom in
the cavity by a factor of 60 to more than 2 seconds. In contrast to previous
feedback schemes, our algorithm is also capable of cooling a much faster ~ 500
kHz oscillation mode within just microseconds. This demonstrates that
parametric cooling is a powerful technique that can be applied in all
experiments where optical access is limited.Comment: 7 pages, 5 figure
Arm bone loading index predicts DXA musculoskeletal outcomes in two samples of post-menarcheal girls
Abstract Objective: A site-specific bone loading index was developed to predict post-menarcheal arm bone mass, geometry, areal density and non-bone lean mass using organized activity records. Methods: Two cohorts of post-menarcheal girls (A= 55, B= 48) met analysis inclusion criteria: 1) Whole body and non-dominant radius DXA scans +1.0 to +2.6 years post-menarche; 2) detailed, organized activity records available for 36 months prior to the focal DXA scan; 3) accompanying anthropometric data. DXA non-dominant arm and radius regions of interest (1/3, Ultradistal (UD)) were evaluated. An arm bone loading index (arm totBLI) was developed and refined to describe >50 activities. Separate regression analyses for Cohorts A&B tested explanatory value of arm totBLI for DXA outcomes, accounting for gynecological age, height and whole body non-bone lean mass. Results: In both cohorts, arm totBLI reflecting 3 years of peri-menarcheal activity exposure exhibited strong explanatory value for post-menarcheal radius and arm outcomes (squared semi-partial r =0.07-0.34, p<0.05), except Arm Area. For both cohorts and most outcomes, arm totBLI explained significant variance, even after adjusting for local muscle mass. Conclusions: In two independent cohorts, arm totBLI may consistently indicate osteogenic and sarcogenic properties of represented activities; additional research is necessary for further refinement and validation
Вибір та обґрунтування параметрів технології підтримки стінок стовбура свердловини в осадових породах
Практичне значення роботи полягає в досліджені широкого кола властивостей різних хімічних сполук, покликаних збільшити ступінь стійкості осадових порід в стінках стовбура свердловини; застосування досліджених речовин приведе до істотного підвищення продуктивності бурових робіт, скорочення часу на роботи, пов’язані із ліквідацією ускладнень і аварій в свердловині, або повного виключення останніх, загального зростання ефективності і економічності процесу спорудження свердловин.Мета дипломної роботи: встановлення закономірностей фізико-хімічних процесів, що протікають в стовбурі свердловини, споруджуваної в товщі осадових гірських порід, при циркуляції промивальних рідин і формулюванні на їх основі адекватних технологічних заходів гідравлічної програми промивання свердловини, реалізація якої дозволить надати процесу спорудження свердловин достатньо високу міру продуктивності і економічності
Distribution of Culex coronator in the USA
In 1920, Culex coronator was reported from San Benito, Texas, and later in Arizona, New Mexico, and Oklahoma. In 2005, this species was reported to be spreading across the southeastern USA. Now reported in 14 states, it has been found as far north as northern Oklahoma; Memphis, TN; and Suffolk, VA. The public health significance of Cx. coronator is not firmly established, even though it has been implicated as a potential vector of several arboviral diseases. This study aims to document additional Cx. coronator county-level records, to provide information about its continued expansion across the southern USA, and to provide a short research update into its vector potential. Data acquired through multistate collaborations and author collections resulted in 146 new county records from Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, and Texas. No new county records were presented for Arizona, New Mexico, Tennessee, or Virginia, which had previously reported this species. With these new data, this species has been documented in 386 counties in 14 states of the continental USA.Peer reviewedEntomology and Plant Patholog
Cerebral aneurysm exclusion by CT angiography based on subarachnoid hemorrhage pattern: a retrospective study
<p>Abstract</p> <p>Background</p> <p>To identify patients with spontaneous subarachnoid hemorrhage for whom CT angiography alone can exclude ruptured aneurysms.</p> <p>Methods</p> <p>An observational retrospective review was carried out of all consecutive patients with non-traumatic subarachnoid hemorrhage who underwent both CT angiography and catheter angiography to exclude an aneurysm. CT angiography negative cases (no aneurysm) were classified according to their CT hemorrhage pattern as "aneurismal", "perimesencephalic" or as "no-hemorrhage."</p> <p>Results</p> <p>Two hundred and forty-one patients were included. A CT angiography aneurysm detection sensitivity and specificity of 96.4% and 96.0% were observed. All 35 cases of perimesencephalic or no-hemorrhage out of 78 CT angiography negatives also had negative angiography findings.</p> <p>Conclusions</p> <p>CT angiography is self-reliant to exclude ruptured aneurysms when either a perimesencephalic hemorrhage or no-hemorrhage pattern is identified on the CT within a week of symptom onset.</p
Photon-Atom Coupling with Parabolic Mirrors
Efficient coupling of light to single atomic systems has gained considerable
attention over the past decades. This development is driven by the continuous
growth of quantum technologies. The efficient coupling of light and matter is
an enabling technology for quantum information processing and quantum
communication. And indeed, in recent years much progress has been made in this
direction. But applications aside, the interaction of photons and atoms is a
fundamental physics problem. There are various possibilities for making this
interaction more efficient, among them the apparently 'natural' attempt of
mode-matching the light field to the free-space emission pattern of the atomic
system of interest. Here we will describe the necessary steps of implementing
this mode-matching with the ultimate aim of reaching unit coupling efficiency.
We describe the use of deep parabolic mirrors as the central optical element of
a free-space coupling scheme, covering the preparation of suitable modes of the
field incident onto these mirrors as well as the location of an atom at the
mirror's focus. Furthermore, we establish a robust method for determining the
efficiency of the photon-atom coupling.Comment: Book chapter in compilation "Engineering the Atom-Photon Interaction"
published by Springer in 2015, edited by A. Predojevic and M. W. Mitchell,
ISBN 9783319192307, http://www.springer.com/gp/book/9783319192307. Only
change to version1: now with hyperlinks to arXiv eprints of other book
chapters mentioned in this on
A Novel Mitragynine Analog with Low-Efficacy Mu Opioid Receptor Agonism Displays Antinociception with Attenuated Adverse Effects
Mitragynine and 7-hydroxymitragynine (7OH) are the major alkaloids mediating the biological actions of the psychoactive plant kratom. To investigate the structure-activity relationships of mitragynine/7OH templates, we diversified the aromatic ring of the indole at the C9, C10, and C12 positions and investigated their G-protein and arrestin signaling mediated by mu opioid receptors (MOR). Three synthesized lead C9 analogs replacing the 9-OCH3group with phenyl (4), methyl (5), or 3′-furanyl [6(SC13)] substituents demonstrated partial agonism with a lower efficacy than DAMGO or morphine in heterologous G-protein assays and synaptic physiology. In assays limiting MOR reserve, the G-protein efficacy of all three was comparable to buprenorphine.6(SC13) showed MOR-dependent analgesia with potency similar to morphine without respiratory depression, hyperlocomotion, constipation, or place conditioning in mice. These results suggest the possibility of activating MOR minimally (G-proteinEmax≈ 10%) in cell lines while yet attaining maximal antinociceptionin vivowith reduced opioid liabilities
Rheumatoid arthritis: pathological mechanisms and modern pharmacologic therapies.
Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that primarily affects the lining of the synovial joints and is associated with progressive disability, premature death, and socioeconomic burdens. A better understanding of how the pathological mechanisms drive the deterioration of RA progress in individuals is urgently required in order to develop therapies that will effectively treat patients at each stage of the disease progress. Here we dissect the etiology and pathology at specific stages: (i) triggering, (ii) maturation, (iii) targeting, and (iv) fulminant stage, concomitant with hyperplastic synovium, cartilage damage, bone erosion, and systemic consequences. Modern pharmacologic therapies (including conventional, biological, and novel potential small molecule disease-modifying anti-rheumatic drugs) remain the mainstay of RA treatment and there has been significant progress toward achieving disease remission without joint deformity. Despite this, a significant proportion of RA patients do not effectively respond to the current therapies and thus new drugs are urgently required. This review discusses recent advances of our understanding of RA pathogenesis, disease modifying drugs, and provides perspectives on next generation therapeutics for RA
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