Spin g-factor due to electronic interactions in graphene

The gyromagnetic factor is an important physical quantity relating the magnetic-dipole moment of a particle to its spin. The electron spin g-factor in vacuo is one of the best model-based theoretical predictions ever made, showing agreement with the measured value up to ten parts per trillion. However, for electrons in a material the g-factor is modified with respect to its value in vacuo because of environment interactions. Here, we show how interaction effects lead to the spin g-factor correction in graphene by considering the full electromagnetic interaction in the framework of pseudo-QED. We compare our theoretical prediction with experiments performed on graphene deposited on SiO2 and SiC, and we find a very good agreement between them.Comment: Improved version of the manuscript; valley g-factor part has been remove

Patterns of leprosy at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa, and review of current clinical practice

Background. The World Health Organization announced a strategy to eliminate childhood leprosy infections, visible deformities and discriminatory legislation against leprosy patients by 2020. However, challenges in achieving a leprosy-free world and preventing neurological sequelae still exist. HIV infection is a challenge in South Africa (SA). HIV-leprosy co-infection may result in an increase in the frequency of leprosy reactions without affecting the spectrum of leprosy. From 1921 to 1997, the prevalence of leprosy remained <1 patient per 10 000 population. Current SA literature has very scanty information regarding leprosy infections. Objectives. To describe the trend of new leprosy patients at Chris Hani Baragwanath Academic Hospital, Johannesburg, SA, from 1999 to 2015, including demographics, clinical spectrum and treatment outcomes. Methods. A retrospective review of patients’ clinical records was undertaken. Data on demographics, clinical spectrum including the leprosy classification, reactions, neurological involvement, association with HIV infection and treatment outcomes were extracted. Data analysis was performed using descriptive and inferential statistics and a time series analysis. Results. An upward trend from 1999 to 2001 was followed by a decline in the number of new patients. Eighty patients were registered over a period of 17 years, with a male-to-female ratio of 3:1. Thirty-six patients were immigrants, and 5 were children aged <15 years. Multibacillary leprosy was the most common type (n=71 patients). Thirty-six patients had the lepromatous leprosy subtype, 22 were borderline lepromatous, 13 were borderline tuberculoid, 6 were borderline borderline, and 3 had tuberculoid leprosy. Thirty-one patients presented with reactions, type 1 in 9 patients and type 2 in 21 patients, with both types in 1 patient. Grade 2 neurological deformities were diagnosed in 37 patients, of whom 2 were children. Eight patients were found to have HIV-leprosy co-infection. Of 52 patients who completed treatment, 26 were cured and 26 were lost to follow-up. Twenty-one patients defaulted from treatment, while 3 patients relapsed. Conclusions. This study highlights the current status of leprosy in a low-endemic centre with declining numbers of new patients. Multibacillary forms with grade 2 disabilities (G2Ds) are common. The constant emergence of leprosy in our population highlights shortfalls in our control campaigns. Furthermore, a high rate of G2Ds necessitates scrutiny of education directed at early patient detection and follow-up strategies

Fluctuations in network dynamics

Most complex networks serve as conduits for various dynamical processes, ranging from mass transfer by chemical reactions in the cell to packet transfer on the Internet. We collected data on the time dependent activity of five natural and technological networks, finding that for each the coupling of the flux fluctuations with the total flux on individual nodes obeys a unique scaling law. We show that the observed scaling can explain the competition between the system's internal collective dynamics and changes in the external environment, allowing us to predict the relevant scaling exponents.Comment: 4 pages, 4 figures. Published versio

Patterns of leprosy at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa, and review of current clinical practice

Background. The World Health Organization announced a strategy to eliminate childhood leprosy infections, visible deformities and discriminatory legislation against leprosy patients by 2020. However, challenges in achieving a leprosy-free world and preventing neurological sequelae still exist. HIV infection is a challenge in South Africa (SA). HIV-leprosy co-infection may result in an increase in the frequency of leprosy reactions without affecting the spectrum of leprosy. From 1921 to 1997, the prevalence of leprosy remained <1 patient per 10 000 population. Current SA literature has very scanty information regarding leprosy infections.Objectives. To describe the trend of new leprosy patients at Chris Hani Baragwanath Academic Hospital, Johannesburg, SA, from 1999 to 2015, including demographics, clinical spectrum and treatment outcomes.Methods. A retrospective review of patients’ clinical records was undertaken. Data on demographics, clinical spectrum including the leprosy classification, reactions, neurological involvement, association with HIV infection and treatment outcomes were extracted. Data analysis was performed using descriptive and inferential statistics and a time series analysis.Results. An upward trend from 1999 to 2001 was followed by a decline in the number of new patients. Eighty patients were registered over a period of 17 years, with a male-to-female ratio of 3:1. Thirty-six patients were immigrants, and 5 were children aged <15 years. Multibacillary leprosy was the most common type (n=71 patients). Thirty-six patients had the lepromatous leprosy subtype, 22 were borderline lepromatous, 13 were borderline tuberculoid, 6 were borderline borderline, and 3 had tuberculoid leprosy. Thirty-one patients presented with reactions, type 1 in 9 patients and type 2 in 21 patients, with both types in 1 patient. Grade 2 neurological deformities were diagnosed in 37 patients, of whom 2 were children. Eight patients were found to have HIV-leprosy co-infection. Of 52 patients who completed treatment, 26 were cured and 26 were lost to follow-up. Twenty-one patients defaulted from treatment, while 3 patients relapsed.Conclusions. This study highlights the current status of leprosy in a low-endemic centre with declining numbers of new patients. Multibacillary forms with grade 2 disabilities (G2Ds) are common. The constant emergence of leprosy in our population highlights shortfalls in our control campaigns. Furthermore, a high rate of G2Ds necessitates scrutiny of education directed at early patient detection and follow-up strategies

Stochastic Quantization of Topological Field Theory: Generalized Langevin Equation with Memory Kernel

We use the method of stochastic quantization in a topological field theory defined in an Euclidean space, assuming a Langevin equation with a memory kernel. We show that our procedure for the Abelian Chern-Simons theory converges regardless of the nature of the Chern-Simons coefficient

Cytogenetics and cytotaxonomy of Velloziaceae.

Chromosome number and other cytological features are reported from 35 species of Velloziaceae, including several african and brazilian populations. All analyzed species show areticulate interphase nuclei and prophase/prometaphase chromosomes with proximal early condensation. Most heteropycnotic blocks do not seem to correspond to heterochromatin since, at least in Vellozia patens, they do not stain differentially after C-banding procedures. Regarding the chromosome number, three main groups could be identified. The first comprised diploid species of the genera Nanuza, Vellozia and the brazilian species of Xerophyta with 2n=14 or 16; the second comprised tetraploid species with 2n=34, and included all brazilian species of subfam. Barbacenioideae; the third group, of hexaploid species, comprised the African representatives of the genus Xerophyta. A single population of Vellozia, possibly of hybrid origin, had 2n~=32. A basic number of x=8 is proposed for the family. The karyological information supports the hypothesis that the Velloziaceae originated on the South American, rather than on the African continent

The pasta phase within density dependent hadronic models

In the present paper we investigate the onset of the pasta phase with different parametrisations of the density dependent hadronic model and compare the results with one of the usual parametrisation of the non-linear Walecka model. The influence of the scalar-isovector virtual delta meson is shown. At zero temperature two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature only the coexistence phases method is used. npe matter with fixed proton fractions and in beta-equilibrium are studied. We compare our results with restrictions imposed on the the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.Comment: 15 pages, 11 figures and 7 table

Phytase-producing Bacillus sp. inoculation increases phosphorus availability in cattle manure

Organic wastes rich in phosphorus (P) are considered an alternative to decrease the dependence on chemical P fertilization in crops and pastures. Microbial inoculants are being studied as a tool to increase plant P availability in organic wastes. In this study, we explore the effect of inoculation with Bacillus sp. MQH-19 (a native phytase-producing bacterium) on the release of inorganic phosphorus (Pi) in cattle manure with low available P but a high total P content. Bacteria inoculation resulted in a higher release of Pi (8% in NaHCÜ3 and 13% in NaOH-EDTA extracts) compared with that of uninoculated manure (0.7% in NaHCÜ3 and 0.1% in NaOH-EDTA extracts). However, a greater amount of Pi was released in inoculated manure supplemented with phytate (47% in NaHCÜ3 and 117% in NaOH-EDTA extracts) compared with that of uninoculated manure supplemented with phytate (30% in NaHCÜ3 and 15% in NaOH-EDTA extracts). In addition, the use of denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) revealed that the bacterial community structure in manure was affected by inoculation and that the prevalence of Bacillus sp. MQH-19 decreased during incubation (6 days). This study demonstrates that Pi availability in cattle manure can be increased by phytase-producing bacteria inoculation. Phytase-producing bacteria inoculation might represent an attractive strategy to increase P availability in agricultural wastes, which are used as organic fertilizers in crops and pastures

A Simple and Quick Method for the Determination of Pesticides in Environmental Water by HF-LPME-GC/MS

This paper describes a simple and quick method for sampling and also for carrying out the preconcentration of pesticides in environmental water matrices using two-phased hollow fiber liquid phase microextraction (HF-LPME). Factors such as extraction mode, time, solvents, agitation, and salt addition were investigated in order to validate the LPME method. The following conditions were selected: 6 cm of polypropylene hollow fiber, ethyl octanoate as an acceptor phase, and extraction during 30 min under stirring at 200 rpm. The optimized method showed good linearity in the range of 0.14 to 200.00 μg L−1; the determination coefficient (R2) was in the range of 0.9807–0.9990. The LOD ranged from 0.04 μg L−1 to 0.44 μg L−1, and LOQ ranged from 0.14 μg L−1 to 1.69 μg L−1. The recovery ranged from 85.17% to 114.73%. The method was applied to the analyses of pesticides in three environmental water samples (a spring and few streams) collected in a rural area from the state of Minas Gerais, Brazil