Land use effects on heavy metal pollution of river sediments in Guilan, southwest of the Caspian sea

Studies have showed the River Siahroud is the main contributor to the present pollution of Anzali Wetland in Guilan. Therefore, this study was initiated to evaluate the spatial distribution of metals pollution on the River Siahroud sediments in Guilan. Surfacial river sediment samples along this river were taken during five consecutive seasons at eight sampling stations and analyzed for availability of Fe, Mn, Pb, Zn, Cu, Cr, Cd metals. Canonical correlation demonstrated that the total organic carbon (TOC) was of great importance in co-precipitation of Zn while Cu and Pb were mainly related to hydrous iron oxides. Also, in the interest of pollutant finger printing, factor analysis showed that extractable Zn, Cu, Fe, Cd and Mn were attributed to the present agricultural fields while industrial site of Rasht City was the major contributing factor for the extended levels of Cr in the study area. Moreover, Pb level was mainly relevant to urban land use in Rasht. Cluster analysis demonstrated that there was a rising metal pollution level in the River Siahroud from upstream to downstream suggesting that Anzali Wetland pollution could be highly related to loading of heavy metals by the River Siahroud sediment

Dynamics of entanglement of bosonic modes on symmetric graphs

We investigate the dynamics of an initially disentangled Gaussian state on a general finite symmetric graph. As concrete examples we obtain properties of this dynamics on mean field graphs of arbitrary sizes. In the same way that chains can be used for transmitting entanglement by their natural dynamics, these graphs can be used to store entanglement. We also consider two kinds of regular polyhedron which show interesting features of entanglement sharing.Comment: 14 pages, 11 figures, Accepted for publication in Physics Letters

Concurrence in Disordered Systems

Quantum systems exist at finite temperatures and are likely to be disordered to some level. Since applications of quantum information often rely on entanglement, we require methods which allow entanglement measures to be calculated in the presence of disorder at non-zero temperatures. We demonstrate how the disorder averaged concurrence can be calculated using thermal many-body perturbation theory. Our technique can also be applied to other entanglement measures. To illustrate, we find the disorder averaged concurrence of an XX spin chain. We find that concurrence can be increased by disorder in some parameter regimes.Comment: 14 pages, 5 figure

The frequency of transforming growth factor-TGF-B gene polymorphisms in a normal southern Iranian population

Several single nucleotide polymorphisms (SNPs) of the transforming growth factor-β1 gene (TGFB1) have been reported. Determination of TGFB1 SNPs allele frequencies in different ethnic groups is useful for both population genetic analyses and association studies with immunological diseases. In this study, five SNPs of TGFB1 were determined in 325 individuals from a normal southern Iranian population using polymerase chain reaction-restriction fragment length polymorphism method. This population was in Hardy-Weinberg equilibrium for these SNPs. Of the 12 constructed haplotypes, GTCGC and GCTGC were the most frequent in the normal southern Iranian population. Comparison of genotype and allele frequencies of TGFB SNPs between Iranian and other populations (meta-analysis) showed significant differences, and in this case the southern Iranian population seems genetically similar to Caucasoid populations. However, neighbour-joining tree using Nei's genetic distances based on TGF-β1 allele frequencies showed that southern Iranians are genetically far from people from the USA, Germany, UK, Denmark and the Czech Republic. In conclusion, this is the first report of the distribution of TGFB1 SNPs in an Iranian population and the results of this investigation may provide useful information for both population genetic and disease studies. © 2008 The Authors

A general algorithm for manipulating non-linear and linear entanglement witnesses by using exact convex optimization

A generic algorithm is developed to reduce the problem of obtaining linear and nonlinear entanglement witnesses of a given quantum system, to convex optimization problem. This approach is completely general and can be applied for the entanglement detection of any N-partite quantum system. For this purpose, a map from convex space of separable density matrices to a convex region called feasible region is defined, where by using exact convex optimization method, the linear entanglement witnesses can be obtained from polygonal shape feasible regions, while for curved shape feasible regions, envelope of the family of linear entanglement witnesses can be considered as nonlinear entanglement witnesses. This method proposes a new methodological framework within which most of previous EWs can be studied. To conclude and in order to demonstrate the capability of the proposed approach, besides providing some nonlinear witnesses for entanglement detection of density matrices in unextendible product bases, W-states, and GHZ with W-states, some further examples of three qubits systems and their classification and entanglement detection are included. Also it is explained how one can manipulate most of the non-decomposable linear and nonlinear three qubits entanglement witnesses appearing in some of the papers published by us and other authors, by the method proposed in this paper. Keywords: non-linear and linear entanglement witnesses, convex optimization. PACS number(s): 03.67.Mn, 03.65.UdComment: 37 page

On handling urban informality in southern Africa

In this article I reconsider the handling of urban informality by urban planning and management systems in southern Africa. I argue that authorities have a fetish about formality and that this is fuelled by an obsession with urban modernity. I stress that the desired city, largely inspired by Western notions of modernity, has not been and cannot be realized. Using illustrative cases of top–down interventions, I highlight and interrogate three strategies that authorities have deployed to handle informality in an effort to create or defend the modern city. I suggest that the fetish is built upon a desire for an urban modernity based on a concept of formal order that the authorities believe cannot coexist with the “disorder” and spatial “unruliness” of informality. I question the authorities' conviction that informality is an abomination that needs to be “converted”, dislocated or annihilated. I conclude that the very configuration of urban governance and socio-economic systems in the region, like the rest of sub-Saharan Africa, renders informality inevitable and its eradication impossible

Quantitative Imaging of Regional Aerosol Deposition, Lung Ventilation and Morphology by Synchrotron Radiation CT

To understand the determinants of inhaled aerosol particle distribution and targeting in the lung, knowledge of regional deposition, lung morphology and regional ventilation, is crucial. No single imaging modality allows the acquisition of all such data together. Here we assessed the feasibility of dual-energy synchrotron radiation imaging to this end in anesthetized rabbits; both in normal lung (n = 6) and following methacholine (MCH)-induced bronchoconstriction (n = 6), a model of asthma. We used K-edge subtraction CT (KES) imaging to quantitatively map the regional deposition of iodine-containing aerosol particles. Morphological and regional ventilation images were obtained, followed by quantitative regional iodine deposition maps, after 5 and 10 minutes of aerosol administration. Iodine deposition was markedly inhomogeneous both in normal lung and after induced bronchoconstrition. Deposition was significantly reduced in the MCH group at both time points, with a strong dependency on inspiratory flow in both conditions (R-2 = 0.71; p <0.0001). We demonstrate for the first time, the feasibility of KES CT for quantitative imaging of lung deposition of aerosol particles, regional ventilation and morphology. Since these are among the main factors determining lung aerosol deposition, we expect this imaging approach to bring new contributions to the understanding of lung aerosol delivery, targeting, and ultimately biological efficacy.Peer reviewe

Naked-eye detection of morphine by Au@Ag nanoparticles-based colorimetric chemosensors

In this study, we report a novel and facile colorimetric assay based on silver citrate-coated Au@Ag nanoparticles (Au@AgNPs) as a chemosensor for the naked-eye detection of morphine (MOR). The developed optical sensing approach relied on the aggregation of Au@Ag NPs upon exposure to morphine, which led to an evident color variation from light-yellow to brown. Au@Ag NPs have been prepared by two different protocols, using high- and low-power ultrasonic irradiation. The sonochemical method was essential for the sensing properties of the resulting nanoparticles. This facile sensing method has several advantages including excellent stability, selectivity, prompt detection, and cost-effectiveness

Voltage-controlled Hubbard spin transistor

Transistors are key elements for enabling computational hardware in both classical and quantum domains. Here we propose a voltage-gated spin transistor using itinerant electrons in the Hubbard model which acts at the level of single electron spins. Going beyond classical spintronics, it enables the controlling of the flow of quantum information between distant spin qubits. The transistor has two modes of operation, open and closed, which are realized by two different charge configurations in the gate of the transistor. In the closed mode, the spin information between source and drain is blocked while in the open mode we have free spin information exchange. The switching between the modes takes place within a fraction of the operation time which allows for several subsequent operations within the coherence time of the transistor. The system shows good resilience against several imperfections and opens up a practical application for quantum dot arrays

Effects of diabetes mellitus on health-related quality of life at a tertiary hospital in South Africa: A cross-sectional study

Background. Diabetes mellitus (DM) is a chronic metabolic disease that potentially causes debilitating and life-threatening complications, demands a lifestyle change, and has important implications with regard to wellbeing and health-related quality of life (HRQOL).Objectives. To: (i) determine the HRQOL of a sample of patients with type 2 diabetes; (ii) describe the demographics (age, gender, and smoking and alcohol use) of the population studied; (iii) document the following parameters, which are important in determining the control and severity of type 2 diabetes: (a) glycosylated haemoglobin (HbA1c), (b) total amount of insulin required per day (if on insulin therapy), (c) body mass index (BMI), and (d) exercise compliance; (iv) determine whether there was an association between any or all of the above parameters and the HRQOL of these patients; and (v) determine whether coexisting diseases (hypertension (HT) and dyslipidaemia) were present, and compare HRQOL between diabetic patients with and without these diseases.Methods. This was a cross-sectional and descriptive study of 200 patients attending the diabetes clinic at Helen Joseph Hospital, Johannesburg, South Africa. HRQOL assessments were made using the Diabetes 39 (D-39) questionnaire, which patients filled in once consent had been obtained and if they fulfilled the inclusion criteria. Patients’ questionnaire forms were then analysed with regard to their demographics (age and gender), exercise regimen, smoking and alcohol history, employment status, living arrangements, age of diagnosis of DM, and concurrent use of antihypertensive and cholesterol-lowering drugs. The patients’ files were analysed and various clinical parameters were noted (HbA1c, lipogram, BMI, number of insulin units used per day, and whether any antihypertensive and/or lipidlowering drugs were used).Results. There was an association between HRQOL and HbA1c, and between HRQOL and HT and dyslipidaemia.Conclusions. No association was found between HRQOL and other clinical parameters, namely number of insulin units used per day, exercise, BMI, lipogram and the use of oral hypoglycaemic agents. Demographic parameters (age, gender, age at diagnosis, employment status and living arrangements) were also shown to have no impact on HRQOL. We found no association between HRQOL in patients who consumed alcohol and smoked cigarettes and in those who did not