Search for Active-Sterile Antineutrino Mixing Using Neutral-Current Interactions with the NOvA Experiment.

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10^{20} protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ν[over ¯]_{µ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05 eV^{2}≤Δm_{41}^{2}≤0.5 eV^{2}, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3+1 confidence limits set using long-baseline accelerator antineutrinos.

Increase in polysialyltransferase gene expression following LTP in adult rat dentate gyrus.

Neural cell adhesion molecule (NCAM) is frequently associated with polysialic acid (PSA), and its function is highly dependent on this polysialylation. PSA-NCAM plays an important role in synaptic plasticity in the hippocampus. STX and PST are the enzymes responsible for NCAM polysialylation. We investigated whether unilateral long-term potentiation (LTP) induction in vivo, in adult rat dentate gyrus (DG), triggered NCAM polysialylation by STX and PST produced in the hippocampus. We found that levels of STX and PST mRNA increased strongly since the early stage of hippocampal LTP and remained high during the maintenance of DG-LTP for 4 h. This rapid increase in polysialyltransferase gene expression occurred in both the hippocampi, probably resulting from bilateral LTP induction by strong unilateral HFS. Thus, LTP triggers interhemispheric molecular changes in the hippocampal network. This study is the first to describe the effects of LTP induction and maintenance on polysialyl-transferases in vivo. Our findings suggest that hippocampal synaptic remodeling requires NCAM polysialylation.

Dentists of tomorrow 2020: An analysis of the results of the 2020 ADEA Survey of U.S. Dental School Seniors.

PURPOSE/OBJECTIVES: This study examines the journey of U.S. dental schools' predoctoral senior class of 2020, from the influences on and their motivations to pursue careers in dentistry, aspects of their dental school experiences, to plans upon graduation and the investment in their careers. METHODS: The study is an analysis of the results of the ADEA Survey of Dental School Seniors, 2020 Graduating Class. Each year, ADEA surveys senior predoctoral students from the accredited U.S. dental schools. Whenever feasible, the answers of the survey respondents from the 2020 class were compared with their 2015 counterparts. RESULTS: The analysis revealed that 46% of the 2020 respondents decided to become a dentist before going to undergraduate college, more than the proportion of those deciding while in college (42%). When it comes to preparedness to practice dentistry, the responses indicated a high level of readiness to go into the profession. Seventy-seven percent of survey participants reported the COVID-19 pandemic did not affect their plans after graduation. Between 2015 and 2020, the share of survey respondents who planned to go into advanced dental education immediately after graduation increased from 35% to 40%. Almost a third of the 2020 respondents who planned to go into private practice immediately upon graduation intended to join a Dental Service Organization (DSO). Grants and scholarships represented a higher share of the average funding for dental education for the 2020 respondents than five years ago. The share of respondents expecting to graduate without any loans to finance their dental degrees and predental education (educational debt) increased significantly, from 12% in 2015 to 17% in 2020. CONCLUSION(S): This research shows that during these uncertain times, U.S. dental schools continued their mission to train and graduate oral health professionals fully prepared to go into the profession.

[Vertebroplasty: 10 years clinical and radiological follow-up]. / Vertébroplastie: évaluation clinique et radiologique à plus de dix ans.

OBJECTIVES: Ten years follow-up of the first patients treated with percutaneous vertebroplasty. PATIENT AND METHODS: Eighteen patients were retrospectively reviewed having undergone vertebroplasty in our centre between 1989 and 1998. Eight were treated for angioma, eight for osteoporotic compression and two followed for myeloma. They all underwent clinical and radiological evaluation in 2007 (standard X-rays, CT scan and MRI). These examinations were compared to prior baseline pre- and post-therapeutic images. RESULTS: Radiological characteristic of cement remained unchanged in the long term and there was no modification of anatomical structures in contact with it. Even if the distribution of cement was asymmetrical there was no fracture of the treated vertebras at distance. Degenerative changes of discs facing the vertebroplasty were not more pronounced than for distant discs. We found no significant signal or density anomaly of disc in contact direct with cement. 38.8 % of the patients presented new fractures (n=30). Seventy percent of the fractures were multiple and contiguous. In the long term, all patients reported improvement of pain after the procedure. CONCLUSION: In our series, we found a good stability of treatment over time. This study shows the long-term safety of percutaneous acrylic vertebroplasty, in particular harmlessness of cement for bone and discs in contact.

Masking technique for coating thickness control on large and strongly curved aspherical optics.

We discuss a method to control the coating thickness deposited onto large and strongly curved optics by ion beam sputtering. The technique uses an original design of the mask used to screen part of the sputtered materials. A first multielement mask is calculated from the measured two-dimensional coating thickness distribution. Then, by means of an iterative process, the final mask is designed. By using such a technique, it has been possible to deposit layers of tantalum pentoxide having a high thickness gradient onto a curved substrate 500 mm in diameter. Residual errors in the coating thickness profile are below 0.7%.

[Bithalamic infarct: is there an evocative aspect? Radioclinical study]. / Accident vasculaire ischémique bithalamique: existe-t-il un tableau évocateur ? Etude radioclinique.

INTRODUCTION: Bithalamic paramedian infarcts are uncommon. This stroke results in a complex clinical syndrome. CASE REPORT: We report four cases of bithalamic paramedian infarcts with a presumed mechanism of occlusion of a single thalamic paramedian artery. DISCUSSION: This normal anatomic variant corresponds to an asymmetrical common trunk for the two thalamosubthalamic paramedian arteries arising from a P1 segment (type IIb in the G. Percheron classification dating from 1977). A literature analysis (from 1985 to 2006) allowed us to identify the most widely reported clinical signs. Four main clinical findings are described: vertical gaze palsy (65%), memory impairment (58%), confusion (53%) and coma (42%). We also found these symptoms in our patients but rarely associated; however, all four patients had exhibited episodes of drowsiness. In this article, we discuss the anatomy-function correlation responsible for such clinical variability. CONCLUSION: Clinicians should be aware of this diagnosis to better understand the imaging results which provide confirmation. Although the literature describes frequently severe consciousness disorders such as coma, this diagnosis must also be considered in patients presenting a simple fluctuation of consciousness, e.g. hypersomnia.

[Arterial spin labeling: state of the art]. / Etat de l'art sur le Marquage de Spin Artériel ou ASL.

UNLABELLED: Arterial spin labeling (ASL) perfusion MR imaging is a technique by which water from circulating arterial blood is magnetically labeled and acts as a diffusible tracer allowing non-invasive measurement of cerebral blood flow. In this paper, the technique and current applications in neuroimaging will be reviewed. CURRENT STATUS: First, the technical principles of ASL will be reviewed and both available techniques (continuous and pulsed ASL) explained. A review of the literature will demonstrate advances with the techniques of ASL and its clinical impact. Clinical research involves normal volunteers and patients with ischemic and tumoral pathologies. CONCLUSION: Recent technical advances have improved the sensitivity of ASL perfusion MR imaging. The routine clinical use of ASL at 3.0 Tesla should increase over the next few years.

Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications.

Because of its ideal band gap, high density and high electron mobility-lifetime product, cadmium zinc telluride (CdZnTe or CZT) is currently the best room-temperature compound-semiconductor X- and gamma-ray detector material. However, because of its innate poor thermo-physical properties and above unity segregation coefficient for Zn, the wide spread deployment of this material in large-volume CZT detectors is still limited by the high production cost. The underlying reason for the low yield of high-quality material is that CZT suffers from three major detrimental defects: compositional inhomogeneity, high concentrations of dislocation walls/sub-grain boundary networks and high concentrations of Te inclusions/precipitates. To mitigate all these disadvantages, we report for the first time the effects of the addition of selenium to the CZT matrix. The addition of Se was found to be very effective in arresting the formation of sub-grain boundaries and its networks, significantly reducing Zn segregation, improving compositional homogeneity and resulting in much lower concentrations of Te inclusions/precipitates. Growth of the new quaternary crystal Cd1-xZnxTe1-ySey (CZTS) by the Traveling Heater Method (THM) is reported in this paper. We have demonstrated the production of much higher yield according to its compositional homogeneity, with substantially lower sub-grain boundaries and their network, and a lower concentration of Te inclusions/precipitates.

Efficient and tolerant resonant grating coupler for multimode optical interconnections.

More than 60% overall coupling efficiency is achieved in the demonstrator of an optical interconnect comprising an input grating coupler, a multimode slab waveguide section and an output grating coupler. The grating coupling strength is enhanced by means of a leaky mode resonance. The efficiency of the resonant grating coupler compares favourably with the performancs reported on mirror inserts.

Morphological and functional imaging of neck paragangliomas.

OBJECTIVE: To review the optimal techniques for localization and characterization of neck paragangliomas (PGL). MATERIAL AND METHODS: Systematic review of the literature from the PubMed/Medline database. RESULTS: Neck PGL are hypervascular tumours essentially arising from paraganglionic tissue situated at the carotid bifurcation (carotid body) and along the vagus nerve. Morphological and functional imaging are indicated to confirm the diagnosis, identify multifocal disease and for local and regional staging. MR angiography is the noninvasive technique of choice. CT scan and especially CT angiography are excellent alternatives for diagnosis and staging. Conventional arteriography remains useful preoperatively for embolization and occlusion tests. Functional imaging allows localization and characterization of PGLs. Somatostatin receptor scintigraphy (SRS) was the reference imaging technique for staging of sporadic PGLs. The indications for PET imaging have been extended over recent years in parallel with the development of new tracers such as [18F]-FDOPA PET or 68Gallium-labelled DOTA peptides. 68Gallium-labelled DOTA peptides has become the first-line imaging modality in the evaluation of cervical PGLs, regardless of the genetic background. CONCLUSION: Morphological and functional imaging is essential for the staging of neck PGL.