Precision measurement of gravity with cold atoms in an optical lattice and comparison with a classical gravimeter

We report on a high precision measurement of gravitational acceleration using ultracold strontium atoms trapped in a vertical optical lattice. Using amplitude modulation of the lattice intensity, an uncertainty $\Delta g /g \approx 10^{-7}$ was reached by measuring at the 5$^{th}$ harmonic of the Bloch oscillation frequency. After a careful analysis of systematic effects, the value obtained with this microscopic quantum system is consistent with the one we measured with a classical absolute gravimeter at the same location. This result is of relevance for the recent interpretation of related experiments as tests of gravitational redshift and opens the way to new tests of gravity at micrometer scale.Comment: 4 pages, 4 figure

A simple abstraction of arrays and maps by program translation

We present an approach for the static analysis of programs handling arrays, with a Galois connection between the semantics of the array program and semantics of purely scalar operations. The simplest way to implement it is by automatic, syntactic transformation of the array program into a scalar program followed analysis of the scalar program with any static analysis technique (abstract interpretation, acceleration, predicate abstraction,.. .). The scalars invariants thus obtained are translated back onto the original program as universally quantified array invariants. We illustrate our approach on a variety of examples, leading to the " Dutch flag " algorithm

Fine structure and functional morphology of the mouthparts of a male Veigaia sp (Gamasida: Veigaiidae) with remarks on the spermatodactyl and related sensory structures

Mites of the genus Veigaia are common gamasid inhabitants of forest litter. They engage in the peculiar reproductive strategy of podospermy which, along with other morphological and behavioral adaptations, involves modification of the chelicerae of the relatively rare males into gonopods. Each movable digit is provided with an appendage (spermatodactyl) that is involved in sperm transfer. We describe the gross anatomy, fine structure, and functional morphology of the mouthparts of a male Veigaia species and give ultrastructural details for the corniculi, laciniae, preoral cavity, labrum, pharynx, and movable and fixed digits. The fine structure of the spermatodactyl is illustrated here for the first time in detail. A semischematic reconstruction of the gnathosoma and spermatodactyl is provided. The spermatodactyl is totally fused with the movable digit and a sperm transfer duct runs along its entire length. This duct starts at the adaxial base of the movable digit, continues inside the digit into the tube of the spermatodactyl, and finally opens at the distal abaxial surface of the spermatodactyl. Several sensory structures associated with the spermatodactyl probably provide the male with mechanical and chemical clues

On the structure of phase transition maps for three or more coexisting phases

This paper is partly based on a lecture delivered by the author at the ERC workshop "Geometric Partial Differential Equations" held in Pisa in September 2012. What is presented here is an expanded version of that lecture.Comment: 23 pages, 6 figure

A fast and easy approach to the simulation of binary mixtures sorption kinetics

Diffusivity of a component in a binary mixture is affected by the presence of a second component. The knowledge of the influence on each other component diffusivity is very useful for the prediction of sorption kinetics of binary mixtures. In this work kinetic studies of Cr(VI) and Cu(II) binary mixtures sorption onto exhausted coffee encapsulated in calcium alginate beads were carried out in both bench and pilot scale experiments. The spectroscopic analysis evidenced the complexity of the process since different mechanisms such as adsorption, redox reaction and ion exchange are involved. Experimental data were fitted to the Linear Adsorption Model (LAM). An empirical quadratic model was developed to estimate LAM parameters (De) and α = Cf/(Ci − Cf) as a function of the initial concentration of metals in the mixture. The empirical model developed enables to estimate the LAM parameters (De and α) of metal ions binary mixtures provided that the initial concentration of the metal ions is included in the range of concentrations studied. The estimated parameters introduced in LAM equation allow simulating the corresponding binary mixtures sorption kinetics. This study constitutes a fast and easy approach to the modelling of sorption kinetics of complex systems in which different processes take place simultaneously

The influence of implant position and of prosthetic characteristics on the occurrence of peri-implantitis: a retrospective study on periapical radiographs.

OBJECTIVE: The present retrospective study aimed to investigate the influence of malposition on the occurrence of peri-implantitis. MATERIALS AND METHODS: The study included clinical records of systemically healthy patients with single and partial implant-supported rehabilitations and at least 1-year post-loading follow-up. The parameters collected included implant-related factors, patient-related factors, site-related factors, and prosthesis-related factors. The radiographic measurements were taken by using a dedicated software and the diagnosis of peri-implantitis was made based on all the available clinical and radiographic data. Descriptive statistics were provided for all variables. Following an exploratory approach, an implant-level analysis of factors influencing the occurrence of peri-implantitis was done through a multilevel multivariate logistic regression (mixed). RESULTS: A total of 180 implants belonging to 90 subjects were randomly selected. Malposition showed no statistically significant association with the occurrence of peri-implantitis. According to the multi-level analysis, the parameters that were significantly associated with peri-implantitis included presence / history of periodontitis (OR = 5.945, 95% CI: 1.093 - 32.334, P = 0.039) and presence of an emergence profile angle ≥ 45° (OR = 9.094, 95% CI: 2.017 - 40.995, P = 0.005). CONCLUSIONS: Implant malposition, as defined following Buser's criteria (2004), did not influence the occurrence of peri-implantitis in the selected cohort. Conversely, history of periodontitis and presence of a prosthetic emergence profile with an angle ≥ 45° were correlated to an increased risk of peri-implantitis

FORCE- AND POWER-TIME RELATIONSHIP,EMG RESPONSES IN CONCENTRIG AND ISOMETRIC CONDITIONS,EFFECTS OF TRAINING AND INDIVIDUAL CRARACTERISTICS

Introduction The relationship between EHG (temporal pattern, IEMG, power spectra ) and the biomechanical parameter in isometric and dynamic muscle tension represents an essential method in the analysis of the specificity of training effects and of the individual characteristics in motor control modelling and in practical motor learning. METHODS Force-time, power-time relationships under concentric and isometric conditions (MVC) with and without preloading were determined. For EHG purpose, surface electrodes (O= 5 mm; interelectrode distance 40 mm) were placed over the belly of each muscle (Tric.br.;Bic.br.; Delt.an.; Pect.ma.). Bipolar myoelectrical potentials were recorded with the passive electrode placed between the two actives: signals were preamplified and band-pass filtered (CMRRT 70 db, BP= 10 Hz- 1 KHz: Zin=1,5 MR. gain= 1000). EMG signals and the force were digitized on-line with a sampling frequency of 1000 Hz. For time structure analysis EMG signals were full-wave rectified and bandpass filtered (20-70 Hz) to obtain envelop curve patterns of each muscle. Power spectra analysis (median frequency MF) were performed using 1024 and pl2 data points. 3 groups (n=4) of sport students were involved in the investigation. Subjects performed a 8 week training period under different loading conditions. RESULTS # In the concentric tasks subjects show individual strategies in the muscular coordination patterns dependent on the load intensity. # Differences in the muscular interactivity pattern are not necessarily matching similar variation in the mechanical output. # For increasing loads there is a linear relationship between muscular activation level and mechanical power output. # In the power spectra, trends are consistent but also discontinuous. Median frequency could possibly indicate that some subjects have resources in motor units recruitment . # Other considerations are discussed referring to the muscular activation and the isometric MVC under preloading conditions