Classical trajectories in quantum transport at the band center of bipartite lattices with or without vacancies

Here we report on several anomalies in quantum transport at the band center of a bipartite lattice with vacancies that are surely due to its chiral symmetry, namely: no weak localization effect shows up, and, when leads have a single channel the transmission is either one or zero. We propose that these are a consequence of both the chiral symmetry and the large number of states at the band center. The probability amplitude associated to the eigenstate that gives unit transmission ressembles a classical trajectory both with or without vacancies. The large number of states allows to build up trajectories that elude the blocking vacancies explaining the absence of weak localization.Comment: 5 pages, 5 figure

Frequency response of Valencia oranges to selective harvesting by vibration

Citrus mechanical harvesting has been investigated since the 1960’s. Even though mechanical harvesting could significantly lower production costs, the implementation by the private sector has been slow. The current harvesting technologies detach the fruits with trunk, canopy or branch vibration. For late-season sweet orange varieties which simultaneously bear mature fruit, immature fruitlets and flowers shaker harvesting decreases the subsequent year’s yield. This study, investigated the frequency response of mature fruits and immature fruitlets to determine the optimum frequency range for an efficient and selective harvest. Laboratory vibration transmission tests were conducted with 14 branches bearing 76 mature fruits and 151 immature ‘Valencia’ fruitlets. The fruit and branch response to the forced vibration was measured by several sets of five triaxial accelerometers with a dynamic signal analyser. Three frequency ranges with the highest vibration transmission values were identified for mechanical harvesting lower than 10 Hz. The first frequency range (1.5-2.5 Hz) corresponded best with the most efficient vibration transmission, involving more than 90% of fruit. The second frequency range (4.5-5 Hz) successfully discriminated between mature fruit and immature fruitlets. In this frequency range, 53.4% of mature fruit amplified the acceleration a mean value of 2.2 times, while only 7.3% of immature fruitlets amplified the acceleration with a mean value of 4.4 times. The lowest third frequency range had a vibration transmission value of 7-8 Hz. The frequency response of mature citrus fruits, and their markedly higher fruit mass, were significant factors in efficient selective mechanical harvesting

Mobilising men: ally identities and collective action in Japan and the Philippines

Men have an important role as allies in reducing discrimination against women. Following the Social Identity Model of Collective Action (SIMCA), we examined whether men's identification with women would predict their allied collective action, alongside moral convictions, efficacy, and anger. We also examined whether identification with their own ingroup would decrease their willingness to improve women's situation. We tested the SIMCA, extended to consider ingroup identification among men, in Japan (N = 103) and the Philippines (N = 131). Consistent with the SIMCA, moral convictions and group efficacy predicted men's willingness to engage in collective action to fight discrimination against women. However, anger was not significant, and identification with the advantaged and disadvantaged groups played different roles in the two countries. We discuss the possible role of norms and legitimacy in society in explaining the pattern of results

The (p,q) String Tension in a Warped Deformed Conifold

We find the tension spectrum of the bound states of p fundamental strings and q D-strings at the bottom of a warped deformed conifold. We show that it can be obtained from a D3-brane wrapping a 2-cycle that is stabilized by both electric and magnetic fluxes. Because the F-strings are Z_M-charged with non-zero binding energy, binding can take place even if (p,q) are not coprime. Implications for cosmic strings are briefly discussed.Comment: 17 pages, 1 figur

Theory of asymmetric non-additive binary hard-sphere mixtures

We show that the formal procedure of integrating out the degrees of freedom of the small spheres in a binary hard-sphere mixture works equally well for non-additive as it does for additive mixtures. For highly asymmetric mixtures (small size ratios) the resulting effective Hamiltonian of the one-component fluid of big spheres, which consists of an infinite number of many-body interactions, should be accurately approximated by truncating after the term describing the effective pair interaction. Using a density functional treatment developed originally for additive hard-sphere mixtures we determine the zero, one, and two-body contribution to the effective Hamiltonian. We demonstrate that even small degrees of positive or negative non-additivity have significant effect on the shape of the depletion potential. The second virial coefficient $B_2$, corresponding to the effective pair interaction between two big spheres, is found to be a sensitive measure of the effects of non-additivity. The variation of $B_2$ with the density of the small spheres shows significantly different behavior for additive, slightly positive and slightly negative non-additive mixtures. We discuss the possible repercussions of these results for the phase behavior of binary hard-sphere mixtures and suggest that measurements of $B_2$ might provide a means of determining the degree of non-additivity in real colloidal mixtures

Macromolecular theory of solvation and structure in mixtures of colloids and polymers

The structural and thermodynamic properties of mixtures of colloidal spheres and non-adsorbing polymer chains are studied within a novel general two-component macromolecular liquid state approach applicable for all size asymmetry ratios. The dilute limits, when one of the components is at infinite dilution but the other concentrated, are presented and compared to field theory and models which replace polymer coils with spheres. Whereas the derived analytical results compare well, qualitatively and quantitatively, with mean-field scaling laws where available, important differences from ``effective sphere'' approaches are found for large polymer sizes or semi-dilute concentrations.Comment: 23 pages, 10 figure

The AMMA mulid network for aerosol characterization in West Africa

Three ground based portable low power consumption microlidars (MULID) have been built and deployed at three remote sites in Banizoumbou (Niger), Cinzana (Mali) and M'Bour (Senegal) in the framework of the African Monsoon Multidisciplinary Analyses (AMMA) project for the characterization of aerosols optical properties. A description of the instrument and a discussion of the data inversion method, including a careful analysis of measurement uncertainties (systematic and statistical errors) are presented. Some case studies of typical lidar profiles observed over the Banizoumbou site during 2006 are shown and discussed with respect to the AERONET 7-day back-trajectories and the biomass burning emissions from the Combustion Emission database for the AMMA campaign

Clinical presentation and outcome of invasive mould disease in paediatric patients with acute lymphoblastic leukaemia

Background: Childhood acute lymphoblastic leukaemia (ALL) cure rates have improved, but invasive mould disease (IMD) remains a life-threatening complication. Here, we evaluate the epidemiology, clinical presentation, treatment and outcome of IMD in paediatric patients with ALL. Methods: Patients (1–18 years) treated according to the Dutch Childhood Oncology Group (DCOG) ALL-11 protocol from 2012–2021 were analysed for probable and proven IMD. Data was extracted from the Dutch national registry and the electronic health care system. Results: Among 643 patients with ALL, 47 (7.3%) were diagnosed with a probable (n = 29) or proven (n = 18) IMD. Aspergillosis was diagnosed in 42 (89%) patients. Forty-one episodes (87%) occurred during the induction (n = 20) and first consolidation (n = 21) course. The median age at ALL diagnosis was 5 years [IQR 3–10] in the overall group versus 14 years [IQR 7–16] in the IMD group. Two-third of the patients did not receive mould-active prophylaxis. The most prevalent clinical symptoms at presentation were persistent fever and respiratory symptoms. The lungs were the most common site of infection with involvement in 44 (94%) patients, followed by the CNS in 16 (34%) patients. The 6-week and 12-week mortality rate after IMD diagnosis was 10.6% and 14.9%, respectively. Discussion and conclusion: In our paediatric cohort a notable incidence of probable and proven IMD was observed during the early stages of treatment. Remarkable is the high frequency of CNS involvement. These findings highlight the importance of effective prophylactic strategies and warrant early brain imaging

Gaussian Tunneling Model of c-Axis Twist Josephson Junctions

We calculate the critical current density $J^J_c$ for c-axis Josephson tunneling between identical high temperature superconductors twisted an angle $\phi_0$ about the c-axis. We model the tunneling matrix element squared as a Gaussian in the change of wavevector q parallel to the junction, $<|t({\bf q})|^2>\propto\exp(-{\bf q}^2a^2/2\pi^2\sigma^2)$. The $J^J_c(\phi_0)/J^J_c(0)$ obtained for the s- and extended-s-wave order parameters (OP's) are consistent with the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ data of Li {\it et al.}, but only for strongly incoherent tunneling, $\sigma^2\ge0.25$. A $d_{x^2-y^2}$-wave OP is always inconsistent with the data. In addition, we show that the apparent conventional sum rule violation observed by Basov et al. might be understandable in terms of incoherent c-axis tunneling, provided that the OP is not $d_{x^2-y^2}$-wave.Comment: 6 pages, 6 figure