2,369 research outputs found

    Interactions and scattering of quantum vortices in a polariton fluid

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    Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin-vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull-push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.Comment: 12 pages, 7 figures, Supplementary Material and 5 movies included in arXi

    Radio-guided Surgery for Non-131 I-avid Thyroid Cancer

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63206/1/thy.2006.16.1105.lowlink.pdf_v03.pd

    A Portrait of Cold Gas in Galaxies at 60pc Resolution and a Simple Method to Test Hypotheses That Link Small-Scale ISM Structure to Galaxy-Scale Processes

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    The cloud-scale density, velocity dispersion, and gravitational boundedness of the interstellar medium (ISM) vary within and among galaxies. In turbulent models, these properties play key roles in the ability of gas to form stars. New high fidelity, high resolution surveys offer the prospect to measure these quantities across galaxies. We present a simple approach to make such measurements and to test hypotheses that link small-scale gas structure to star formation and galactic environment. Our calculations capture the key physics of the Larson scaling relations, and we show good correspondence between our approach and a traditional "cloud properties" treatment. However, we argue that our method is preferable in many cases because of its simple, reproducible characterization of all emission. Using, low-J 12CO data from recent surveys, we characterize the molecular ISM at 60pc resolution in the Antennae, the Large Magellanic Cloud, M31, M33, M51, and M74. We report the distributions of surface density, velocity dispersion, and gravitational boundedness at 60pc scales and show galaxy-to-galaxy and intra-galaxy variations in each. The distribution of flux as a function of surface density appears roughly lognormal with a 1sigma width of ~0.3 dex, though the center of this distribution varies from galaxy to galaxy. The 60pc resolution line width and molecular gas surface density correlate well, which is a fundamental behavior expected for virialized or free-falling gas. Varying the measurement scale for the LMC and M31, we show that the molecular ISM has higher surface densities, lower line widths, and more self-gravity at smaller scales.Comment: Accepted for publication in the Astrophysical Journal, 36 pages (24+appendix), 21 figures (12+appendix), until publication high resolution version at http://www.astronomy.ohio-state.edu/~leroy.42/cloudscale.pd

    Conditions of work and dermatitis in workers exposed to chemical risks by cement

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    This research was carried out in order to identify the working conditions in workers exposed to cement in a cement factory in the city of Cartagena. Through different tools it was possible to carry out the diagnosis of the working conditions and to identify the hazards to which the workers of the company are exposed when being in direct contact with the cement; in this way it was possible to know that the dermatitis that were manifesting the workers has its direct relation with this chemical and therefore to be able to establish those measures tending to ensure the complete state of health of the workers. The type of research carried out is descriptive-qualitative, the applied methodology used as a closed questions survey tool, it was obtained as a result that 70% of the respondents did not use personal protection elements when handling cement, so can say that there is a considerable number of people exposed, which increases the likelihood that they may suffer contact dermatitis, through this the different preventive measures for working and health conditions among the employees of the cement company were raised

    PHANGS CO kinematics: disk orientations and rotation curves at 150 pc resolution

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    We present kinematic orientations and high resolution (150 pc) rotation curves for 67 main sequence star-forming galaxies surveyed in CO (2-1) emission by PHANGS-ALMA. Our measurements are based on the application of a new fitting method tailored to CO velocity fields. Our approach identifies an optimal global orientation as a way to reduce the impact of non-axisymmetric (bar and spiral) features and the uneven spatial sampling characteristic of CO emission in the inner regions of nearby galaxies. The method performs especially well when applied to the large number of independent lines-of-sight contained in the PHANGS CO velocity fields mapped at 1'' resolution. The high resolution rotation curves fitted to these data are sensitive probes of mass distribution in the inner regions of these galaxies. We use the inner slope as well as the amplitude of our fitted rotation curves to demonstrate that CO is a reliable global dynamical mass tracer. From the consistency between photometric orientations from the literature and kinematic orientations determined with our method, we infer that the shapes of stellar disks in the mass range of log(M(M)\rm M_{\star}(M_{\odot}))=9.0-10.9 probed by our sample are very close to circular and have uniform thickness.Comment: 19 figures, 36 pages, accepted for publication in ApJ. Table of PHANGS rotation curves available from http://phangs.org/dat

    Unsuspected role of the brain morphogenetic gene Otx1 in hematopoiesis

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    Otx1 belongs to the paired class of homeobox genes and plays a pivotal role in brain development. Here, we show that Otx1 is expressed in hematopoietic pluripotent and erythroid progenitor cells. Moreover, bone marrow cells from mice lacking Otx1 exhibit a cell-autonomous impairment of the erythroid compartment. In agreement with these results, molecular analysis revealed decreased levels of erythroid genes that include the SCL and GATA-1 transcription factors. Accordingly, a gain of function of SCL rescues the erythroid deficiency in Otx1-/- mice. Taken together, our findings indicate a function for Otx1 in the regulation of blood cell production. There is growing evidence suggesting that common cellular and molecular mechanisms orchestrate differentiation in various tissues. Homeobox-containing genes seem to be strong candidate genes to regulate a number of developmental processes, including neurogenesis and hematopoiesis. Members of the Otx family (Otx1, Otx2, Otx3, and Crx) are the vertebrate homologues of the Drosophila head gap gene orthodenticle and encode transcription factors containing a bicoid-like homeodomain. They are temporally and spatially regulated during development and seem to be required for proper head and sense organ patterning. Otx1, Otx2, and Otx3 show partially overlapping, but distinct expression patterns, and Otx2, the first to be activated during development, plays a major role in gastrulation and in the early specification of the anterior neural plate. In contrast, Otx1 shows a later onset and is involved in corticogenesis, sense organ development, and pituitary function. Mice bearing targeted deletion of Otx1 are affected by a permanent epileptic phenotype and show multiple brain abnormalities and morphological defects of the acoustic and visual sense organs. In addition, at the prepubescent stage, they exhibit transient dwarfism and hypogonadism because of low levels of pituitary hormones. In the present study, we have investigated whether Otx1 also plays a role in blood cell production, as several homeobox genes of different families are involved in normal and/or malignant hematopoiesis

    Dispersion and collapse in stochastic velocity fields on a cylinder

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    The dynamics of fluid particles on cylindrical manifolds is investigated. The velocity field is obtained by generalizing the isotropic Kraichnan ensemble, and is therefore Gaussian and decorrelated in time. The degree of compressibility is such that when the radius of the cylinder tends to infinity the fluid particles separate in an explosive way. Nevertheless, when the radius is finite the transition probability of the two-particle separation converges to an invariant measure. This behavior is due to the large-scale compressibility generated by the compactification of one dimension of the space

    PHANGS-JWST First Results: A Global and Moderately Resolved View of Mid-Infrared and CO Line Emission from Galaxies at the Start of the JWST Era

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    We explore the relationship between mid-infrared (mid-IR) and CO rotational line emission from massive star-forming galaxies, which is one of the tightest scalings in the local universe. We assemble a large set of unresolved and moderately (1\sim 1 kpc) spatially resolved measurements of CO (1-0) and CO (2-1) intensity, ICOI_{\rm CO}, and mid-IR intensity, IMIRI_{\rm MIR}, at 8, 12, 22, and 24μ\mum. The ICOI_{\rm CO} vs. IMIRI_{\rm MIR} relationship is reasonably described by a power law with slopes 0.71.20.7{-}1.2 and normalization ICO1I_{\rm CO} \sim 1 K km s1^{-1} at IMIR1I_{\rm MIR} \sim 1 MJy sr1^{-1}. Both the slopes and intercepts vary systematically with choice of line and band. The comparison between the relations measured for CO~(1-0) and CO (2-1) allow us to infer that R21IMIR0.2R_{21} \propto I_{\rm MIR}^{0.2}, in good agreement with other work. The 8μ8\mum and 12μ12\mum bands, with strong PAH features, show steeper CO vs. mid-IR slopes than the 22μ22\mum and 24μ24\mum, consistent with PAH emission arising not just from CO-bright gas but also from atomic or CO-dark gas. The CO-to-mid-IR ratio correlates with global galaxy stellar mass (MM_\star) and anti-correlates with SFR/MM_\star. At 1\sim 1 kpc resolution, the first four PHANGS-JWST targets show CO to mid-IR relationships that are quantitatively similar to our larger literature sample, including showing the steep CO-to-mid-IR slopes for the JWST PAH-tracing bands, although we caution that these initial data have a small sample size and span a limited range of intensities.Comment: 29 pages, 13 figures, key quantitative results in Table 3, Accepted as part of a PHANGS-JWST Focus Issue to appear in Ap

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical management of pulmonary inflammatory pseudotumors: A single center experience

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    <p>Abstract</p> <p>Background</p> <p>The pulmonary inflammatory pseudotumor (PIP) is a rare disease. It is still debated whether it represents an inflammatory lesion characterized by uncontrolled cell growth or a true neoplasm. PIP is characterized by a cellular polymorphism.</p> <p>Methods</p> <p>We retrospectively analyzed 8 patients with PIP treated by surgery between 2001 and 2009. Preoperative thoracic computed tomography (CT) scan was performed in all cases. All patients underwent preoperative bronchoscopy with washing and brushing and/or transbronchial biopsy and preoperative cytology examination</p> <p>Results</p> <p>There were 5 men and 3 women, aged between 38 and 69 years (mean of 58 years). 3 patients (37%) were asymptomatic. The others had symptoms characterized by chest pain, shortness of breath and persistent cough or hemoptysis. 5 patients had neutrophilic leucocytosis. CT scan demonstrated solitary nodules (maximum diameter <3 cm) in 5 patients (62%) and lung masses (maximum diameter >3 cm) in 3 patients (37%). In 2 patients there were signs of pleural infiltration. Distant lesions were excluded in all cases. A preoperative histology examination failed to reach a definitive diagnosis in all patients. At surgery, we performed two lobectomies, one segmentectomy and five wedge resections, these being performed with videothoracoscopy (VATS), except for one patient where open surgery was used. Complete tumor resection was obtained in all patients. According to the Matsubara classification, there were 2 cases of organizing pneumonia, 5 cases of fibrous histiocytoma and one case of lymphoplasmacytoma. All patients were discharged alive from hospital between 4 and 7 days after surgery. At follow-up CT scan performed annually (range 11 to 112 months) (mean 58 months), there were no residual lesions, neither local nor distant recurrences.</p> <p>Conclusions</p> <p>PIP is a rare disease. Many synonyms have been used for this disease, usually in relation to the most represented cell type. The true incidence is unclear. Preoperative diagnosis is difficult to reach, despite performing a bronchoscopy or a transparietal needle aspiration. Different classifications have been proposed for PIP. Either medical, radiation or surgical therapy has been used for PIP. Whenever possible, surgery should be considered the standard treatment. Complete surgical resection is advocated to prevent recurrence.</p
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