Deterministic ratchet from stationary light fields

Ratchets are dynamic systems where particle transport is induced by zero-average forces due to the interplay between nonlinearity and asymmetry. Generally, they rely on the effect of a strong external driving. We show that stationary optical lattices can be designed to generate particle flow in one direction while requiring neither noise nor driving. Such optical fields must be arranged to yield a combination of conservative (dipole) and nonconservative (radiation pressure) forces. Under strong friction all paths converge to a discrete set of limit periodic trajectories flowing in the same direction.Comment: 6 pages, 4 figure

Hybrid layers of etch-and-rinse versus self-etching adhesive systems

Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rinse self-priming adhesives exhibited thicker hybrid layers than those found in self-etching adhesive systems. The all-in-one adhesive showed droplet formation between the adhesive and the resin composite. The resin tags formed with the etch-and-rinse adhesives were much longer than those found with the self-etching adhesives. Lateral branch formation was observed in etch-and-rinse adhesives and in one of the self-etch adhesives Clearfil SE Bond (SEB). Conclusion: The formed hybrid layer obtained with the two-step selfetching adhesives and the etch-and-rinse systems were continuous and uniform in thickness. Droplets within the all-in-one adhesive layer may occur as a result of water absorption from dentin through osmosis, and may interfere with proper resin polymerization. Resin tags obtained with SEB and the etch-and-rinse adhesive systems showed lateral branches, which is a sign of proper resin infiltration

Strong magnetic response of submicron Silicon particles in the infrared

High-permittivity dielectric particles with resonant magnetic properties are being explored as constitutive elements of new metamaterials and devices in the microwave regime. Magnetic properties of low-loss dielectric nanoparticles in the visible or infrared are not expected due to intrinsic low refractive index of optical materials in these regimes. Here we analyze the dipolar electric and magnetic response of loss-less dielectric spheres made of moderate permittivity materials. For low material refractive index there are no sharp resonances due to strong overlapping between different multipole contributions. However, we find that Silicon particles with refractive index 3.5 and radius approx. 200nm present a dipolar and strong magnetic resonant response in telecom and near-infrared frequencies, (i.e. at wavelengths approx. 1.2-2 micrometer). Moreover, the light scattered by these Si particles can be perfectly described by dipolar electric and magnetic fields, quadrupolar and higher order contributions being negligible.Comment: 10 pages, 5 figure

Medicaments: quin, quan, com...Projecte d’Aprenentatge i Servei per a secundària. Guia didàctica

Il·lustracions originals de Roser Bosch Mestres.La unitat didàctica que hem realitzat té com objectiu principal dissenyar un projecte d’Aprenentatge i Servei (APS) centrat en el bon ús dels medicaments. El projecte es caracteritza per ser una proposta educativa adreçada a joves d’ESO o de 1r curs de Batxillerat que combina activitats d’aprenentatge amb activitats de servei a la comunitat. Pensem que és un enfocament metodològic que ajuda a desenvolupar i a assolir determinades competències bàsiques, a la vegada que motiva l’alumnat, ja que es presenta un ensenyament contextualitzat i significatiu per a la comunitat. Els projectes d’APS responen a una necessitat concreta i rellevant de l’entorn social i, sempre que es pugui, ha d’implicar un acord de col·laboració entre diferents agents o institucions socials que possibilitin aquesta reciprocitat de beneficis d’aprenentatge i de servei. En aquest cas hem treballat com “partners” amb el Col·legi de farmacèutics, amb les farmàcies del barri i amb el SIGRE (responsable del reciclatge dels medicaments)

Prosthetic rehabilitation of an edentulous cleft palate using a denture with a palatal obturator: a clinical report

A cleft palate is a genetic disorder that occurs when an oro-nasal communication is present between the palate and the base of the nose. During pregnancy, the maxillary is not completely merged, and the defect is only seen at birth. Possible causes are hormonal imbalances, nutritional deficiencies, infections, radiation during pregnancy, alcohol or cigarette consumption, the ingestion of other teratogenic substances by the mother, and heredity. The resulting defect requires corrective surgery. In the case of a cleft palate, surgery is postponed until after the first year of life to avoid disturbing the normal development of speech and the risk of aspiration of food, which causes infections such as otitis and pneumonia. Ear infections can harm the development of speech in cases where surgery is not possible or the defect has reappeared. This article describes the prosthetic rehabilitation of a edentulous patient: a woman of 53 years old with a cleft palate who was treated surgically. In a clinical examination, a residual palatal defect was identified. The prosthetic rehabilitation involved the emplacement of a complete adapted prosthesis, using a palatal obturator, with a view to sealing the defect and allowing the patient to acquire better speech quality, and improve her nutrition and well-being

Nucleon-Nucleon Interaction: A Typical/Concise Review

Nearly a recent century of work is divided to Nucleon-Nucleon (NN) interaction issue. We review some overall perspectives of NN interaction with a brief discussion about deuteron, general structure and symmetries of NN Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN interaction models, as frameworks to build NN potentials, are reviewed concisely. We try to include and study almost all well-known potentials in a similar way, discuss more on various commonly used plain forms for two-nucleon interaction with an emphasis on the phenomenological and meson-exchange potentials as well as the constituent-quark potentials and new ones based on chiral effective field theory and working in coordinate-space mostly. The potentials are constructed in a way that fit NN scattering data, phase shifts, and are also compared in this way usually. An extra goal of this study is to start comparing various potentials forms in a unified manner. So, we also comment on the advantages and disadvantages of the models and potentials partly with reference to some relevant works and probable future studies.Comment: 85 pages, 5 figures, than the previous v3 edition, minor changes, and typos fixe

Combined effects of time spent in physical activity, sedentary behaviors and sleep on obesity and cardio-metabolic health markers: a novel compositional data analysis approach

<div><p>The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity.</p></div

A composite Bayesian hierarchical model of compositional data with zeros

We present an effective approach for modelling compositional data with large concentrations of zeros and several levels of variation, applied to a database of elemental compositions of forensic glass of various use types. The procedure consists of the following: (i) partitioning the data set in subsets characterised by the same pattern of presence/absence of chemical elements and (ii) fitting a Bayesian hierarchical model to the transformed compositions in each data subset. We derive expressions for the posterior predictive probability that newly observed fragments of glass are of a certain use type and for computing the evidential value of glass fragments relating to two competing propositions about their source. The model is assessed using cross-validation, and it performs well in both the classification and evidence evaluation tasks

Power laws of natural swarms are fingerprints of an extended critical region

Collective biological systems display power laws for macroscopic quantities and are fertile probing grounds for statistical physics. Besides power laws, natural insect swarms present strong scale-free correlations, suggesting closeness to phase transitions. Swarms exhibit $imperfect$ dynamic scaling: their dynamical correlation functions collapse into single curves when written as functions of the scaled time $t\xi^{-z}$ ($\xi$: correlation length, $z$: dynamic exponent), but only for short times. Triggered by markers, natural swarms are not invariant under space translations. Measured static and dynamic critical exponents differ from those of equilibrium and many nonequilibrium phase transitions. Here, we show that the recently discovered scale-free-chaos phase transition of the harmonically confined Vicsek model has a novel extended critical region for finitely many insects. Unlike results of other theoretical approaches, our numerical simulations of the critical region reproduce the previously described features of natural swarms and yield static and dynamic critical exponents that agree with observations.Comment: 6 pages, 4 figures in the main text, 5 pages, 8 figures in supplementary materia