Characterization of the HAYSTAC axion dark matter search cavity using microwave measurement and simulation techniques

Many searches for axion cold dark matter rely on the use of tunable electromagnetic resonators. Current detectors operate at or near microwave frequencies and use cylindrical cavities with cylindrical tuning rods. The cavity performance strongly impacts the signal power of the detector, which is expected to be very small even under optimal conditions. There is strong motivation to characterize these microwave cavities and improve their performance in order to maximize the achievable signal power. We present the results of a study characterizing the HAYSTAC (Haloscope At Yale Sensitive to Axion Cold dark matter) cavity using bead perturbation measurements and detailed 3D electromagnetic simulations. This is the first use of bead perturbation methods to characterize an axion haloscope cavity. In this study, we measured impacts of misalignments on the order of 0.001 in and demonstrated that the same impacts can be predicted using electromagnetic simulations. We also performed a detailed study of mode crossings and hybridization between the TM$_{010}$ mode used in operation and other cavity modes. This mixing limits the tuning range of the cavity that can be used during an axion search. By characterizing each mode crossing in detail, we show that some mode crossings are benign and are potentially still useful for data collection. The level of observed agreement between measurements and simulations demonstrates that finite element modeling can capture non-ideal cavity behavior and the impacts of very small imperfections. 3D electromagnetic simulations and bead perturbation measurements are standard tools in the microwave engineering community, but they have been underutilized in axion cavity design. This work demonstrates their potential to improve understanding of existing cavities and to optimize future designs.Comment: 22 pages, 8 figures The following article has been submitted to Review of Scientific Instruments. v2: added changes made during the review proces

Free microvascular tissue transfer for the reconstruction of midfacial defects in oncological patients

This study reviews our experience with free microvascular tissue transfer for the repair of midfacial defects in surgical oncology. From 2000 to 2008, eight patients with maxillectomy defects were immediately reconstructed using free flaps. Their clinical charts were retrospectively reviewed to record demographic data, ablative and reconstructive procedures, complications and outcome. Free tissue transfer was successful in all patients, giving an overall success rate of 100%. The mean follow-up time was 4 to 101 months (mr: 43.8). Three patients died from the disease giving a patient mortality of 30%, while five patients are alive, free of disease and back to their normal daily activities. The restoration of function and improvement of patients? quality of life was a common feature in all our reconstructions. The development of free tissue transfer has made surgical treatment of oncological patients with maxillectomy defects previously considered inoperable possible, improving at the same time their quality of life

KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea

High energy neutrinos produced in astrophysical processes will allow for a new way of studying the universe. In order to detect the expected flux of high energy neutrinos from specific astrophysical sources, neutrino telescopes of a scale of a km^3 of water will be needed. A Northern Hemisphere detector is being proposed to be sited in a deep area of the Mediterranean Sea. This detector will provide complimentary sky coverage to the IceCube detector being built at the South Pole. The three neutrino telescope projects in the Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design, and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a 3-year Design Study; the status of the Design Study is presented and some technical issues are discussed.Comment: 4 pages, 3 figures, Prepared for the 10th International Conference on Astroparticle and Underground Physics (TAUP 2007), Sendai, Japan, 11-15 Sep 200

Infected lingual osseous choristoma : report of a case and review of the literature

Osseous choristoma is a rare, benign lesion of the oral cavity occurring usually in the tongue. It appears as a tumorous mass of normal bony structure with mature cells in an ectopic position. The case of a 72 years Caucasian male is presented and analyzed along with 52 similar cases reported in the English literature between 1967 and 2007. Lingual choristoma shows a female predilection, whereas the commonest anatomic location is the posterior third of the tongue, occurring at or close to the foramen caecum and the circumvallate papillae. Histologically the lesions show signs of a well-circumscribed mass of vital bone located under the surface oral epithelium. Some lesions represent developmental malformations, whereas others may be reactive lesions after trauma or chronic irritation. Treatment of lingual osseous choristoma consists of simple excision

Novel neoadjuvant immunotherapy regimen safety and survival in head and neck squamous cell cancer

Background Cellular immune suppression is observed in head and neck squamous cell cancer (HNSCC) and contributes to poor prognosis. Restoration of immune homeostasis may require primary cell‐derived cytokines at physiologic doses. An immunotherapy regimen containing a biologic, with multiple‐active cytokine components, and administered with cytoxan, zinc, and indomethacin was developed to modulate cellular immunity. Methods Study methods were designed to determine the safety and efficacy of a 21‐day neoadjuvant immunotherapy regimen in a phase 2 trial that enrolled 27 therapy‐naïve patients with stage II to IVa HNSCC. Methods included safety, clinical and radiologic tumor response, disease‐free survival (DFS), overall survival (OS), and tumor lymphocytic infiltrate (LI) data collection. Results Acute toxicity was minimal. Patients completed neoadjuvant treatment without surgical delay. By independent radiographic review, 83% had stable disease during treatment. OS was 92%, 73%, and 69% at 12, 24, and 36 months, respectively. Histologic analysis suggested correlation between survival and tumor LI. Conclusion Immunotherapy regimen was tolerated. Survival results are encouraging. © 2011 Wiley Periodicals, Inc. Head Neck, 2011Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88112/1/21660_ftp.pd

Novel organic semiconductors for light-emitting diodes

The intriguing properties of organic semiconductors in various optoelectronic applications, ranging from molecular wires for integrated circuits, to organic photovoltaics (OPV), organic transistors (OFET) and organic light-emitting diodes (OLEDs) have motivated the work presented in this thesis. More precisely, this thesis focuses on narrow energy gap materials, suitable for OLEDs emitting in the red and near-infrared (NIR) regions. Conjugated materials emitting at low energies face great challenges to have efficient light emission. This thesis proposes two very interesting and novel strategies to cope with the limiting factors of efficient light-emission from conjugated compounds. // Firstly, a series of porphyrin oligomers is presented. With emission ranging from red to pure NIR, three architectures of these oligomers were studied. Zinc oligomers at various length that allowed for fine tuning of the emission, five hexamers with different coordinating metals at the centre of each unit, allowing for phosphorescence emission, and a pentamer, with single acetylene instead of butadiyne bonds connecting porphyrin units, resulting in a shorter oligomer with an extended pi-conjugation and a bathochromic shift of the emission. Two limitations can be identified for efficient NIR emission, the so-called ``energy-gap law’’ and aggregation quenching. Both limitations are addressed, resulting in unprecedented external quantum efficiencies when the oligomers are used in OLEDs and remarkable devices lifetimes, considering the non-optimised diodes. // Secondly, three diketopyrrolopyrrole-based copolymers are presented and their photophysical properties discussed. These polymers represent a different strategy to prevent aggregation; by engineering covalent bonds, the conjugated core is sheathed within its cyclic sidechains. The strategy is proven highly successful and the three polymers are compared with their unprotected counterparts, where emission is severely quenched. The advantages of the encapsulation are more pronounced when the polymers are incorporated in OLEDs, where the encapsulated ones achieved up to 16 times higher external quantum efficiencies compared to the unprotected ones

IRX-2, a Novel Immunotherapeutic, Enhances Functions of Human Dendritic Cells

Background: In a recent phase II clinical trial for HNSCC patients, IRX-2, a cell-derived biologic, promoted T-cell infiltration into the tumor and prolonged overall survival. Mechanisms responsible for these IRX-2-mediated effects are unknown. We hypothesized that IRX-2 enhanced tumor antigen-(TA)-specific immunity by up-regulating functions of dendritic cells (DC). Methodology/Principal Findings: Monocyte-derived DC obtained from 18 HNSCC patients and 12 healthy donors were matured using IRX-2 or a mix of TNF-α, IL-1β and IL-6 ("conv. mix"). Multicolor flow cytometry was used to study the DC phenotype and antigen processing machinery (APM) component expression. ELISPOT and cytotoxicity assays were used to evaluate tumor-reactive cytotoxic T lymphocytes (CTL). IL-12p70 and IL-10 production by DC was measured by Luminex® and DC migration toward CCL21 was tested in transwell migration assays. IRX-2-matured DC functions were compared with those of conv. mix-matured DC. IRX-2-matured DC expressed higher levels (p<0.05) of CD11c, CD40, CCR7 as well as LMP2, TAP1, TAP2 and tapasin than conv. mix-matured DC. IRX-2-matured DC migrated significantly better towards CCL21, produced more IL-12p70 and had a higher IL12p70/IL-10 ratio than conv. mix-matured DC (p<0.05 for all). IRX-2-matured DC carried a higher density of tumor antigen-derived peptides, and CTL primed with these DC mediated higher cytotoxicity against tumor targets (p<0.05) compared to the conv. mix-matured DC. Conclusion: Excellent ability of IRX-2 to induce ex vivo DC maturation in HNSCC patients explains, in part, its clinical benefits and emphasizes its utility in ex vivo maturation of DC generated for therapy. © 2013 Schilling et al

Results from phase 1 of the HAYSTAC microwave cavity axion experiment

We report on the results from a search for dark matter axions with the HAYSTAC experiment using a microwave cavity detector at frequencies between 5.6-5.8$\, \rm Ghz$. We exclude axion models with two photon coupling $g_{a\gamma\gamma}\,\gtrsim\,2\times10^{-14}\,\rm GeV^{-1}$, a factor of 2.7 above the benchmark KSVZ model over the mass range 23.15$\,<\,$$m_a \,$<$\,$24.0$\,\mu\rm eV$. This doubles the range reported in our previous paper. We achieve a near-quantum-limited sensitivity by operating at a temperature $T<h\nu/2k_B$ and incorporating a Josephson parametric amplifier (JPA), with improvements in the cooling of the cavity further reducing the experiment's system noise temperature to only twice the Standard Quantum Limit at its operational frequency, an order of magnitude better than any other dark matter microwave cavity experiment to date. This result concludes the first phase of the HAYSTAC program utilizing a conventional copper cavity and a single JPA

Available web-based teaching resources for health care professionals on screening for oral cancer

Objectives: To identify websites with adequate information on oral cancer screening for healthcare professionals (HCPs) and to assess both their quality and contents. Study Design: Websites were identified using Google and HON medical professional search engines using the terms “screening for oral cancer”. The first 100 sites retrieved by each engine were analysed using the DISCERN questionnaire (reliability), the V instrument (contents on oral cancer) and further by the Flesch-Kinkaid Reading Grade Level and the Flesch Reading Ease (readability). Results: The overall rating showed minimal shortcomings in the quality of the information in the websites. The coverage and correctness of information on “visual examination” was rated as fair/good, whereas updating of contents resulted very variable (eg: 81% for visual examination and 18.2% for molecular biomarkers). These results permitted to rank the websites housing relevant information for oral cancer. Top ranking websites were affiliated to the Oral Cancer Foundation (USA), WHO Collaborating Centre for oral cancer (UK) whose webpage is entitled “Oral Cancer Education and Research”, and the Clinical Guidelines maintained by the British Columbia Cancer Agency (Canada) and the British Dental Association (UK) respectively. Conclusions: There are web-based, HCP-addressed, resources on screening for oral cancer housing heterogeneous information both in quality and contents. The use of specific evaluation tools permits the selection of reliable websites on this topic with a potential to improve the existing educational gaps among HCPs