Localization of bosonic atoms by fermionic impurities in a 3d optical lattice

We observe a localized phase of ultracold bosonic quantum gases in a 3-dimensional optical lattice induced by a small contribution of fermionic atoms acting as impurities in a Fermi-Bose quantum gas mixture. In particular we study the dependence of this transition on the fermionic 40K impurity concentration by a comparison to the corresponding superfluid to Mott insulator transition in a pure bosonic 87Rb gas and find a significant shift in the transition parameter. The observed shift is larger than expected based on a mean-field argument, which is a strong indication that disorder-related effects play a significant role.Comment: 4 pages, 4 figure

Deformation Sequence and Paleofluids in Carbonate Buckle Folds Under Transpression (Pag Anticline, External Dinarides, Croatia)

Contractional deformation structures at the front of transpressional orogens display complex three-dimensional geometries deviating from the interpretative templates commonly applied in thrust belts. Accordingly, detailed constraints on deformation patterns and associated paleofluid circulation are desirable, especially for fracture geometry and permeability predictive purposes. The Pag anticline, which is located in the Dinaric fold and thrust belt, provides an appropriate field site for studying fold- and fault-related deformation structures in a transpressive setting. We performed a multiscale structural analysis together with petrographic and stable isotope characterization of the deformation-related calcite cements. Structural mapping suggests that the Pag anticline is a detachment fold developed mainly by buckling, since large-scale thrust faults are absent. Fold tightening in a transpressive setting produced a complex deformational structure including two sets of N-S right-lateral and E-W left-lateral late-stage strike-slip fault sets trending oblique to the NW-SE fold axis. The pre-folding deformation pattern includes incipient normal faults likely related to the forebulge stage, veins and stylolites coherent with NE-SW layer parallel shortening contraction in a strike-slip regime, and metric to decametric scale conjugate thrusts coherent with layer parallel shortening in a compressive regime. Buckle folding preceded propagation of a series of accommodation structures during fold tightening. Petrographic and isotopic data indicate meteoric alteration of the Cretaceous platform carbonates in the prefolding stage, likely due to forebulge subaerial exposure. Layer parallel shortening and early syn-folding veins involved formational fluids resulting from mixed marine and meteoric fluids during folding at shallow burial conditions. Eventually, meteoric fluid infiltrated again along strike-slip faults, acting as cross-formational conduits in the postfolding stage

An integrated atom-photon junction

Photonic chips that integrate guides, switches, gratings and other components, process vast amounts of information rapidly on a single device. A new branch of this technology becomes possible if the light is coupled to cold atoms in a junction of small enough cross section, so that small numbers of photons interact appreciably with the atoms. Cold atoms are among the most sensitive of metrological tools and their quantum nature also provides a basis for new information processing methods. Here we demonstrate a photonic chip which provides multiple microscopic junctions between atoms and photons. We use the absorption of light at a junction to reveal the presence of one atom on average. Conversely, we use the atoms to probe the intensity and polarisation of the light. Our device paves the way for a new type of chip with interconnected circuits of atoms and photons.Comment: 5 pages, 4 figure. Submitted to Nature Photonic

A single atom detector integrated on an atom chip: fabrication, characterization and application

We describe a robust and reliable fluorescence detector for single atoms that is fully integrated into an atom chip. The detector allows spectrally and spatially selective detection of atoms, reaching a single atom detection efficiency of 66%. It consists of a tapered lensed single-mode fiber for precise delivery of excitation light and a multi-mode fiber to collect the fluorescence. The fibers are mounted in lithographically defined holding structures on the atom chip. Neutral 87Rb atoms propagating freely in a magnetic guide are detected and the noise of their fluorescence emission is analyzed. The variance of the photon distribution allows to determine the number of detected photons / atom and from there the atom detection efficiency. The second order intensity correlation function of the fluorescence shows near-perfect photon anti-bunching and signs of damped Rabi-oscillations. With simple improvements one can boost the detection efficiency to > 95%.Comment: 24 pages, 11 figure

Experiments on a videotape atom chip: fragmentation and transport studies

This paper reports on experiments with ultra-cold rubidium atoms confined in microscopic magnetic traps created using a piece of periodically-magnetized videotape mounted on an atom chip. The roughness of the confining potential is studied with atomic clouds at temperatures of a few microKelvin and at distances between 30 and 80 microns from the videotape-chip surface. The inhomogeneities in the magnetic field created by the magnetized videotape close to the central region of the chip are characterized in this way. In addition, we demonstrate a novel transport mechanism whereby we convey cold atoms confined in arrays of videotape magnetic micro-traps over distances as large as ~ 1 cm parallel to the chip surface. This conveying mechanism enables us to survey the surface of the chip and observe potential-roughness effects across different regions.Comment: 29 pages, 22 figures

Salvage photodynamic therapy for recurrent nasopharyngeal carcinoma

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Is there a role for postoperative radiotherapy following open partial laryngectomy when prognostic factors on the pathological specimen are unfavourable? A survey of head and neck surgical/radiation oncologists

Our aim was to survey the opinions of Italian radiation and ENT oncologists regarding the role of postoperative radiotherapy (PRT) and the appropriate dose to be given to patients with remnant larynx (RL) after open partial laryngectomy (OPL). The radio-oncologists (RO s) of the Italian Radiation-Oncologist Association (AIRO) and the ENTs of the Head-Neck Oncology Society (AIOCC-IHNS) were contacted through a SurveyMonkey online interface questionnaire. There were 148 usable responses. The majority of RO s recommended PRT in the case of positive/close margins (R(+)/Rclose) or in the case of initial involvement of thyroid cartilage (pT3tci). In the same cases, ENTs prefer a "watch and wait" policy (w&w). Both disciplines recommended w&w in the case of negative margins (R(-)). Finally, the majority of RO s recommended irradiating RL with 62-66 Gy in R(+), with 56-66 Gy (61.4%) in Rclose and with 56-60 Gy (34%) in pT3tci. In Conclusion, OPL raises new considerations about PRT

Patients' survival after free flap reconstructive surgery of head and neck squamous cell carcinoma : a retrospective multicentre study

Head and neck squamous cell carcinoma of the (HNSCC) represents approximately 5% of malignant tumours in Italy. HNSCC are commonly treated with surgery or radiotherapy, or a combination of such therapies. The objectives of treatment are maximum cure rate balanced with organ preservation, restoration of form and function, reduction of morbidities and improvement or maintenance of the patient's quality of life. Immediate reconstructive surgery: local, regional or free flaps are now widely advised in the treatment of these patients. Microsurgical transfer requires expertise, is time and resource consuming, and as a whole requires substantial costs. These considerations introduce some concerns about the wide or indiscriminate use of free flap reconstructive surgery. When considering cost-benefit outcomes of such treatment, the main objective is undoubtedly, survival. This data is underreported in the current literature, whereas functional outcomes of free flaps have been largely diffused and accepted. This study collects data from 1178 patients treated with free flap reconstructive surgery following ablation of HNSCC in a group of Italian tertiary hospitals, all members of the Head & Neck Group affiliated with the Italian Society of Microsurgery. According to many authors, free flap surgery for HNSCC seems to be a beneficial option for treatment even in terms of survival