Quantum Interference in Single Molecule Electronic Systems

We present a general analytical formula and an ab initio study of quantum interference in multi-branch molecules. Ab initio calculations are used to investigate quantum interference in a benzene-1,2-dithiolate (BDT) molecule sandwiched between gold electrodes and through oligoynes of various lengths. We show that when a point charge is located in the plane of a BDT molecule and its position varied, the electrical conductance exhibits a clear interference effect, whereas when the charge approaches a BDT molecule along a line normal to the plane of the molecule and passing through the centre of the phenyl ring, interference effects are negligible. In the case of olygoynes, quantum interference leads to the appearance of a critical energy $E_c$, at which the electron transmission coefficient $T(E)$ of chains with even or odd numbers of atoms is independent of length. To illustrate the underlying physics, we derive a general analytical formula for electron transport through multi-branch structures and demonstrate the versatility of the formula by comparing it with the above ab-initio simulations. We also employ the analytical formula to investigate the current inside the molecule and demonstrate that large counter currents can occur within a ring-like molecule such as BDT, when the point charge is located in the plane of the molecule. The formula can be used to describe quantum interference and Fano resonances in structures with branches containing arbitrary elastic scattering regions connected to nodal sites.Comment: 12 pages, 11 figure

Fractal space-times under the microscope: A Renormalization Group view on Monte Carlo data

The emergence of fractal features in the microscopic structure of space-time is a common theme in many approaches to quantum gravity. In this work we carry out a detailed renormalization group study of the spectral dimension $d_s$ and walk dimension $d_w$ associated with the effective space-times of asymptotically safe Quantum Einstein Gravity (QEG). We discover three scaling regimes where these generalized dimensions are approximately constant for an extended range of length scales: a classical regime where $d_s = d, d_w = 2$, a semi-classical regime where $d_s = 2d/(2+d), d_w = 2+d$, and the UV-fixed point regime where $d_s = d/2, d_w = 4$. On the length scales covered by three-dimensional Monte Carlo simulations, the resulting spectral dimension is shown to be in very good agreement with the data. This comparison also provides a natural explanation for the apparent puzzle between the short distance behavior of the spectral dimension reported from Causal Dynamical Triangulations (CDT), Euclidean Dynamical Triangulations (EDT), and Asymptotic Safety.Comment: 26 pages, 6 figure

Serve profile of male and female professional tennis players at the 2015 Roland Garros Grand Slam tournament

The aim of this study was to compare the serve statistics profile of male and female high-level tennis players. In all, 111 tennis singles matches of the Roland Garros 2015 tennis tournament were collected and 10 variables related to first and second serve were analyzed according to service box (deuce and advantage sides) and landing location (wide, body and T-areas). The results show: (a) men served faster than women; (b) men served a higher percentage of serves at T-area on deuce side (35.0 vs 27.7%) and at the wide zone on advantage side (44.1 vs 36.7%) with first serves, while women hit more to the body on both sides; (c) men won a higher percentage of points with their first serve compared to women at any zone on both sides, except for the T-area on deuce side; (d) with their second serve, men placed a greater percentage of serves in the T-area on deuce side (28.0 vs 21.8%) and wide on the advantage side, whereas women directed more to the body on the advantage side (41.4 vs 33.5%); (e) men won a higher percentage of points with their second serve when they placed it to the body zone on deuce side (54.1 vs 47.1%) and at the T-area on the advantage side (64.4% vs 44.1%). Our conclusions are that with respect to gender, players showed differing serve patterns. Men served faster, with higher success and placed their serves more frequently to the external areas of the service boxes, while women directed a higher percentage of serves to the body of their opponent

Implications of Halo Inside-out Growth on the X-Ray Properties of Nearby Galaxy Systems within the Preheating Scenario

We present an entirely analytic model for a preheated, polytropic intergalactic medium in hydrostatic equilibrium within a NFW dark halo potential in which the evolution of the halo structure between major merger events proceeds inside-out by accretion. This model is used to explain, within a standard $\Lambda$CDM cosmogony, the observed X-ray properties of nearby relaxed, non-cooling flow groups and clusters of galaxies. We find that our preferred solution to the equilibrium equations produces scaling relations in excellent agreement with observations, while simultaneously accounting for the typical structural characteristics of the distribution of the diffuse baryons. In the class of preheating models, ours stands out because it offers a unified description of the intrahalo medium for galaxy systems with total masses above \sm 2\times 10^{13}\msun, does not produce baryonic configurations with large isentropic cores, and reproduces faithfully the observed behavior of the gas entropy at large radii. All this is achieved with a moderate level of energy injection of about half a keV, which can be easily accommodated within the limits of the total energy released by the most commonly invoked feedback mechanisms, as well as with a polytropic index of 1.2, consistent with both many observational determinations and predictions from high-resolution gas-dynamical simulations of non-cooling flow clusters. More interestingly, our scheme offers a physical motivation for the adoption of this specific value of the polytropic index, as it is the one that best ensures the conservation after halo virialization of the balance between the total specific energies of the gas and dark matter components for the full range of masses investigated.Comment: 18 pages, 11 figures, accepted for publication in the Astrophysical Journa

Statistical Differences in Set Analysis in Badminton at the RIO 2016 Olympic Games

The aim of the present study was to determine statistical differences in a set of badminton competition matches in five different modalities with regard to competition level (Group Phase vs. Eliminatory Phase). Data from 453 sets (125 in men's singles; 108 sets in women's singles; 77 sets in men's doubles; 73 in women's doubles and 70 in mixed doubles) from the RIO 2016 Olympics Games were recorded and classified in two groups of variables to analyze variables related to match (5) and set (15). A descriptive analysis and univariate test (Mann-Whitney U) for non-parametric data were conducted. The results show in men's and women's singles all the variables related to match were higher in the Elimination Phase than in the Group Phase (p < 0.01). In Sets 1 and 3, the longest set duration, rally and average rally were found in the Elimination Phase than Group Stage (p < 0.05). In women's singles, these differences were also recorded in Set 2. For doubles, the results are more stable among groups. Men's doubles had a longer duration of the match and set (sets 1 and set 2) (p < 0.01), and also scored highest for average rally strokes (sets 1 3) < 0.05) and shuttles used in the Elimination Phase vs. the Group Phase along the match (p < 0.01). In women's doubles, more shuttles were used in a match in the Elimination than in the Group Phase. Moreover, the same results are established for Set 2, including for average rally. Mixed doubles saw no match going to three sets. However, the greatest differences showed a longer rally and average rally being registered in the Elimination than in the Group Phase. In conclusion, the timing factors of the badminton singles and doubles games were different in the Elimination and Group Phases. This information may help players and coaches prepare and administer different types of workouts or, more specifically, competition schedules adapted to the characteristics of modern badminton

Myxobolus sp. and Henneguya sp. (Cnidaria: Myxobolidae) natural co-infection in the kidney of Piaractus mesopotamicus(Characiformes: Serrasalmidae)

This study evaluated the myxozoan infection and histopathology of the kidney of freshwater fish Piaractus mesopotamicus from intensive fish farming in Brazil. A total of 55 fish were examined for myxozoan infection. Infected organs were processed by usual histology and stained with hematoxylin-eosin (H&E) and Ziehl-Neelsen (ZN). From the total of 55 fish analyzed, 47 (85.45%) presented myxospores, being 9.09% (5/55) only with Myxobolus sp., 5.45% (3/55) only with Henneguya sp., and 70.91% (39/55) presenting both parasites. The presence of myxospores was associated with histological alterations in both stromal and renal parenchyma. Myxospores were found mostly in the peritubular interstitial tissue and in low intensity in the glomerulus which caused nuclear hypertrophy and loss of Bowman space. An increase in the glomerular tuft and a reduction in the lumen of the collector tubules were also observed, besides the high number of melanomacrophage cells in the glomerulus. This study reports for the first time detection of myxozoan mixed infection in one organ of pacu and discuss the possible transportation of myxospores in the circulating blood

Asymptotic Safety, Emergence and Minimal Length

There seems to be a common prejudice that asymptotic safety is either incompatible with, or at best unrelated to, the other topics in the title. This is not the case. In fact, we show that 1) the existence of a fixed point with suitable properties is a promising way of deriving emergent properties of gravity, and 2) there is a sense in which asymptotic safety implies a minimal length. In so doing we also discuss possible signatures of asymptotic safety in scattering experiments.Comment: LaTEX, 20 pages, 2 figures; v.2: minor changes, reflecting published versio

Renormalization group equation and scaling solutions for f(R) gravity in exponential parametrization

We employ the exponential parametrization of the metric and a \u201cphysical\u201d gauge fixing procedure to write a functional flow equation for the gravitational effective average action in an f(R) truncation. The background metric is a four-sphere and the coarse-graining procedure contains three free parameters. We look for scaling solutions, i.e. non-Gaussian fixed points for the function f. For a discrete set of values of the parameters, we find simple global solutions of quadratic polynomial form. For other values, global solutions can be found numerically. Such solutions can be extended in certain regions of parameter space and have two relevant directions. We discuss the merits and the shortcomings of this procedure. \ua9 2016, The Author(s)