Orientational Melting in a Mesoscopic System of Charged Particles.

A mesoscopic system of a few particles can undergo changes of configuration that resemble phase transitions but with a nonuniversal behavior. A notable example is orientational melting, in which localized particles with long-range repulsive interactions forming a two-dimensional crystal become delocalized in common closed trajectories. Here we report the observation of orientational melting occurring in a two-dimensional crystal of up to 15 ions.

Rate of crop-weed hybridization in × is influenced by genetic background, pollen load, and the environment.

The potential for gene flow between cultivated species and their weedy relatives poses agronomic and environmental concerns, particularly when there are opportunities for the transfer of adaptive or agronomic traits such as herbicide resistance into the weedy forms. Grain sorghum () is an important crop capable of interspecific hybridization with its weedy relative johnsongrass (. Previous findings have shown that triploid progenies resulting from  ×  crosses typically collapse with only a few developing into mature seeds, whereas tetraploids often fully develop.

Design of a Littrow-type diode laser with independent control of cavity length and grating rotation.

We present a novel, to the best of our knowledge, extended-cavity diode laser based on a modified Littrow configuration. The coarse wavelength adjustment via the rotation of a diffraction grating is decoupled from the fine tuning of the external cavity modes by positioning a piezo transducer behind the diode laser, making the laser robust against misalignment and hysteresis even with long external cavities. Two laser prototypes with external cavities of different lengths were tested with a 780 nm laser diode, and locked to an atomic reference.

Human Papillomavirus Infections in Cervical Samples From HIV-Positive Women: Evaluation of the Presence of the Nonavalent HPV Genotypes and Genetic Diversity.

Non-nonavalent vaccine (9v) Human papillomavirus (HPV) types have been shown to have high prevalence among HIV-positive women. Here, 1444 cervical samples were tested for HPV DNA positivity. Co-infections of the 9v HPV types with other HPV types were evaluated.

The Use of Both Therapeutic and Prophylactic Vaccines in the Therapy of Papillomavirus Disease.

Human papillomavirus (HPV) is the most common sexually transmitted virus. The high-risk HPV types (i.e.

Alpha, Beta, gamma human PapillomaViruses (HPV) detection with a different sets of primers in oropharyngeal swabs, anal and cervical samples.

Background: Recent studies have shown a 13-fold increase of oropharyngeal cancer in the presence of HPV, while α-HPV detection seems to be rare in oral cavity in comparison to anal or cervical district, many novel β and γ types have been isolated in this anatomical site suggesting a wide tropism range. Currently, there are no guidelines recommending HPV oral cavity screening as a mandatory test, and it remains unknown which HPV types should be included in HPV screening programs. Our goal was to assess HPV prevalence in oropharyngeal, anal, and cervical swabs using different sets of primers,which are able to amplify α, β, γ HPV types.

A compact radiofrequency drive based on interdependent resonant circuits for precise control of ion traps.

Paul traps are widely used to confine electrically charged particles like atomic and molecular ions by using an intense radiofrequency (RF) field, typically obtained by a voltage drop on capacitative electrodes placed in vacuum. We present a RF drive realized on a compact printed circuit board and providing a high-voltage RF signal to a quadrupole Paul trap. The circuit is formed by using four interdependent resonant circuits - each of which is connected to an electrode of a Paul trap - fed by low-noise amplifiers, leading to an output voltage of peak-to-peak amplitude up to 200 V at 3.

A scalable hardware and software control apparatus for experiments with hybrid quantum systems.

Modern experiments with fundamental quantum systems - like ultracold atoms, trapped ions, and single photons - are managed by a control system formed by a number of input/output electronic channels governed by a computer. In hybrid quantum systems, where two or more quantum systems are combined and made to interact, establishing an efficient control system is particularly challenging due to the higher complexity, especially when each single quantum system is characterized by a different time scale. Here we present a new control apparatus specifically designed to efficiently manage hybrid quantum systems.

Oral human Papillomavirus DNA detection in HIV-positive men: prevalence, predictors, and co-occurrence at anal site.

Background: HIV-positive patients carry an increased risk of HPV infection and associated cancers. Therefore, prevalence and patterns of HPV infection at different anatomical sites, as well as theoretical protection of nonavalent vaccine should be investigated. Aim was to describe prevalence and predictors of oral HPV detection in HIV-positive men, with attention to nonavalent vaccine-targeted HPV types.

Strongly Interacting Gas of Two-Electron Fermions at an Orbital Feshbach Resonance.

We report on the experimental observation of a strongly interacting gas of ultracold two-electron fermions with an orbital degree of freedom and magnetically tunable interactions. This realization has been enabled by the demonstration of a novel kind of Feshbach resonance occurring in the scattering of two (173)Yb atoms in different nuclear and electronic states. The strongly interacting regime at resonance is evidenced by the observation of anisotropic hydrodynamic expansion of the two-orbital Fermi gas.

Observation of chiral edge states with neutral fermions in synthetic Hall ribbons.

Chiral edge states are a hallmark of quantum Hall physics. In electronic systems, they appear as a macroscopic consequence of the cyclotron orbits induced by a magnetic field, which are naturally truncated at the physical boundary of the sample. Here we report on the experimental realization of chiral edge states in a ribbon geometry with an ultracold gas of neutral fermions subjected to an artificial gauge field.

Dynamics of HCV genotype 4 resistance-associated variants during virologic escape with pIFN/RBV+daclatasvir: a case study using ultra deep pyrosequencing.

Background: Daclatasvir (DCV) is an approved NS5A inhibitor with potent anti-HCV activity and broad genotype coverage. DCV resistance-associated variants (RAVs) have been described for patients infected with genotype (GT) 1, but increased GT4 prevalence in European countries as a result of immigration has boosted interest in this genotype.

Objectives: Establishment of NS5A variability in treatment-naive patients with HCV genotype 4 infection and a case study of the dynamics of resistance-associated variants in a virologic failure receiving pIFN/RBV+DCV, as assessed by ultra-deep sequencing.

Direct observation of coherent interorbital spin-exchange dynamics.

We report on the first direct observation of fast spin-exchange coherent oscillations between different long-lived electronic orbitals of ultracold 173Yb fermions. We measure, in a model-independent way, the strength of the exchange interaction driving this coherent process. This observation allows us to retrieve important information on the interorbital collisional properties of 173Yb atoms and paves the way to novel quantum simulations of paradigmatic models of two-orbital quantum magnetism.

Evaluation in a clinical setting of the performances of a new rapid confirmatory assay for HIV1/2 serodiagnosis.

Background And Objectives: The performances of the new Geenius rapid confirmatory test (Bio-Rad) were evaluated with emphasis towards identifying acute infection (AHI) and discriminating HIV-1/2 in a clinical setting

Study Design: Serum samples from individuals attending the L. Spallanzani Institute in Rome, Italy, for HIV diagnosis (one year retrospective collection), repeatedly reactive at 4th generation HIV-1/2 screening assays, confirmed with HIV-1 and HIV-2 Western blot (New LAV I and II Bio-Rad), were retested with Geenius.

Results: Of 6,200 samples, 406 resulted repeatedly reactive at screening, including samples from clinically confirmed AHI.

Temporal trend and characteristics of recent HIV-1 infections: application of an algorithm for the identification of recently acquired HIV-1 infections among newly diagnosed individuals over a 10-year period.

Identification of recent infections (RI) may contribute to improve the quality of human immunodeficiency virus (HIV) surveillance, monitoring ongoing transmission and planning and evaluating prevention programs. Our study applied an algorithm combining clinical and serological information to identify RI in individuals newly diagnosed with HIV in Rome, during the years 1999-2008, in order to describe the trend and characteristics of recently infected individuals. RI were documented seroconverters, or people with an HIV avidity index (AI)<0.

Decoherence of a single-ion qubit immersed in a spin-polarized atomic bath.

We report on the immersion of a spin qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the possibility of a precise microscopic description, which allows us to understand dynamics and decoherence from first principles. We observe the spin dynamics of the qubit and measure the decoherence times (T(1) and T(2)), which are determined by the spin-exchange interaction as well as by an unexpectedly strong spin-nonconserving coupling mechanism.

Comparison of the Abbott RealTime High Risk HPV with Genomica HPV Clinical Array for the detection of human papillomavirus DNA.

Human papillomavirus (HPV) has been identified as the major cause of cervical cancer worldwide and HPV DNA testing is recommended in primary cervical cancer screening. Several molecular tests for detection/typing of HPV DNA with different sensitivity and specificity are commercially available. The present study compared the performance of the Abbott RealTime High Risk HPV assay and the Genomica HPV Clinical Array CLART2 in 78 specimens (63 cervical smears and 15 rectal/urethral swabs).

Frequency and multiplicity of human papillomavirus infection in HIV-1 positive women in Italy.

Background: Natural history of HPV infection is altered in HIV positive women, with increased risk of cervical dysplasia. Limited data are available about the influence of HPV genotypes and HPV multiple infections on cervical disease in HIV positive women.

Objectives: We determined HPV genotype prevalence in cervical samples from 553 HIV-infected women attending the gynaecological service at "L.

HIV incidence estimate combining HIV/AIDS surveillance, testing history information and HIV test to identify recent infections in Lazio, Italy.

Background: The application of serological methods in HIV/AIDS routine surveillance systems to identify persons with recently acquired HIV infection has been proposed as a tool which may provide an accurate description of the current transmission patterns of HIV. Using the information about recent infection it is possible to estimate HIV incidence, according to the model proposed by Karon et al. in 2008, that accounts for the effect of testing practices on the number of persons detected as recently infected.

Cold heteronuclear atom-ion collisions.

We study cold heteronuclear atom-ion collisions by immersing a trapped single ion into an ultracold atomic cloud. Using ultracold atoms as reaction targets, our measurement is sensitive to elastic collisions with extremely small energy transfer. The observed energy-dependent elastic atom-ion scattering rate deviates significantly from the prediction of Langevin but is in full agreement with the quantum mechanical cross section.

Genetic variability in E6, E7 and L1 protein of HPV81 from HIV-1 positive women in Italy.

The genetic variability of E6, E7 and L1 of HPV81 from HIV-1 positive women carrying multiple HPV infections was investigated by clonal analysis for E6 and E7. The range of maximal divergence from the prototype was 0.6%-2.

A trapped single ion inside a Bose-Einstein condensate.

Improved control of the motional and internal quantum states of ultracold neutral atoms and ions has opened intriguing possibilities for quantum simulation and quantum computation. Many-body effects have been explored with hundreds of thousands of quantum-degenerate neutral atoms, and coherent light-matter interfaces have been built. Systems of single or a few trapped ions have been used to demonstrate universal quantum computing algorithms and to search for variations of fundamental constants in precision atomic clocks.

Quantum transport through a Tonks-Girardeau gas.

We investigate the propagation of spin impurity atoms through a strongly interacting one-dimensional Bose gas. The initially well localized impurities are accelerated by a constant force, very much analogous to electrons subject to a bias voltage, and propagate as a one-dimensional impurity spin wave packet. We follow the motion of the impurities in situ and characterize the interaction induced dynamics.

Altered chondrocyte differentiation and extracellular matrix homeostasis in a zebrafish model for mucolipidosis II.

Mucolipidosis II (ML-II) is a pediatric disorder caused by defects in the biosynthesis of mannose 6-phosphate, the carbohydrate recognition signal responsible for targeting certain acid hydrolases to lysosomes. The mechanisms underlying the developmental defects of ML-II are largely unknown due in part to the lack of suitable animal models. To overcome these limitations, we developed a model for ML-II in zebrafish by inhibiting the expression of N-acetylglucosamine-1-phosphotransferase, the enzyme that initiates mannose 6-phosphate biosynthesis.