Prevalence of multiple antibiotic resistant bacteria and chromosomal determinants in surface water of Bangladesh

A total of 210 different bacteria were isolated from water samples collected in different surveillance sites in Bangladesh between May and July 2004. Of these, 147 isolates were analyzed and 103 wereidentified by different biochemical tests as well as stereotyped with specific antiserum. Sixty five percent of these isolates were identified as Escherichia coli which were resistant to multiple drugs including tetracycline, nalidixic acid, kanamycin, streptomycin and sulphamethoxazole-trimethoprim. The remaining thirty five percent of the isolates were Vibrio cholerae, Pseudomonas, Aeromonas,Staphylococcus and Klebsiella. Most of the V. cholerae were nalidixic acid, streptomycin and sulphamethoxazole-trimethoprim resistant. Almost 90% of nalidixic acid resistant V. cholera werestereotyped as non O1. The remaining 10% were O1 and O139. All bacteria were used to isolate plasmid DNA to compare plasmid patterns. The plasmid contents of representative drug resistant strains were analyzed by electroporation to determine the location of antibiotic resistant gene whether it was chromosomal or extrachromosomal. The results of these experiments suggested that Bangladeshienvironmental water including rivers, lakes and ponds contained a large number of multiple antibiotic resistant bacteria and almost all antibiotic resistant determinants were located in the chromosome instead of plasmid

Temperature Dependence Quantum State of Electron in One Dimensional Carbon Nano Tubes and The Expression for Temperature Co-efficient of Resistance in Terms of Quantum State

The Field of Carbon nano tube (CNT) is an promising area of research theoretically as well as experimentally [1],[2]. In fact the band structure of CNT determines its conductivity and in carbon nano tubes the structural pattern affects the conductivity type i.e the conductivity of CNT depends upon how graphene sheet is rolled up. So, CNT can be made to behave as conductor as well as semiconductor [2] It is well established that the samples of single wall carbon nano tubes with an arm chair wrapping have been produced and exhibit metallic behavior with an intrinsic resistivity which increases approximately linearly with temperature over a wide temperature range (see for instance ref.[4]. In this paper the quantized value of electric conductivity [1],[2] is used in an attempt to show theoretically that the quantum state of the electron of the carbon nano tube is directly related to temperature of the CNT as resistivity of CNT depends on quantum state and also found to depend on temperature. Finally, an effort has been made to find an approximatenbsp expression for the temperature co-efficient of resistance of the CNT

Non Dependence of Drift Velocity of Electron on Length of Carbon Nanotubes, Dependence on Quantum State and Expression of Current Density

The field of carbon nano tubes (CNT) is an active area of research theoretically as well experimentallynbsp [1,2]. It is established fact that samples of single wall carbon nano tubes containing tubes with an arm chair wrapping have been produced and exhibit metallic behaviour. In this paper, the quantized value of electrical conductivity is used to show theoretically that the drift velocity of electron is independent of the length of CNT and lsquoVdrsquo, drift velocity varies inversely as the quantum state. From which we can express current density of electrons in CNT and can show current density too depends on quantum state. nbs

Determinants of Bangladesh\u27s Export Flows to the USA, 2003 – 2010: an Empirical Review

IndonesianPenelitian ini menganalisis dampak determinan fungsi ekspor Banglades ke Amerika Serikat selama periode nilai tukar mata uang mengambang bebas, khususnya menguji Hipotesis Linder dalam teori perdagangan Internasional tahun 1961. Model tipe gravitasi diestimasi menggunakan data bulanan dari Mei 2003 hingga Mei 2010. Temuan studi ini mendukung Hipotesis Linder. Dari empat variabel, hanya satu variabel yang memiliki koefisien yang sangat nyata. Semua variabel memiliki tanda koefisien yang sama dengan yang dipostulasikan oleh Linder. Temuan studi ini sangat mendukung keabsahan Hipotesis Linder dalam teori perdagangan Internasional. EnglishThis study investigates the impacts of the determinants of Bangladesh export functions on the export flows to the USA during the period of free and floating exchange rate regime in Bangladesh in order to review the Linder hypotheses postulated in the International trade theory in 1961. The gravity-type model was estimated using monthly data for the sample period May 2003 – May 2010. The findings of the study support Linder Hypotheses exactly. Among the coefficient estimates of four variables only one variable is found to be statistically highly significant. And the signs of all variable coefficients are exactly the same as postulated by Linder. Thus, the findings of this study are fully in support of the validation of the Linder\u27s Hypotheses in International trade theory

Highly Permeable Perfluorinated Sulfonic Acid Ionomers for Improved Electrochemical Devices: Insights into Structure-Property Relationships.

Rapid improvements in polymer-electrolyte fuel-cell (PEFC) performance have been driven by the development of commercially available ion-conducting polymers (ionomers) that are employed as membranes and catalyst binders in membrane-electrode assemblies. Commercially available ionomers are based on a perfluorinated chemistry comprised of a polytetrafluoroethylene (PTFE) matrix that imparts low gas permeability and high mechanical strength but introduces significant mass-transport losses in the electrodes. These transport losses currently limit PEFC performance, especially for low Pt loadings. In this study, we present a novel ionomer incorporating a glassy amorphous matrix based on a perfluoro(2-methylene-4-methyl-1,3-dioxolane) (PFMMD) backbone. The novel backbone chemistry induces structural changes in the ionomer, restricting ionomer domain swelling under hydration while disrupting matrix crystallinity. These structural changes slightly reduce proton conductivity while significantly improving gas permeability. The performance implications of this trade-off are assessed, which reveal the potential for substantial performance improvement by incorporation of highly permeable ionomers as the functional catalyst binder. These results underscore the significance of tailoring material chemistry to specific device requirements, where ionomer chemistry should be rationally designed to match the local transport requirements of the device architecture

Comprehensive Approach of Groundwater Resource Evaluation: A Case Study in the Chippewa Creek Watershed in Ohio

Author Institution: Department of Geological Sciences, State University of New York - New Paltz ; Department of Earth Science, University of Northern Iowa ; Department of Geology, University of AkronA groundwater resource evaluation of Chippewa Creek watershed in Wayne and Medina counties, OH, shows continued availability of groundwater for agriculture and domestic uses. Two major hydrogeologic units in this watershed supply groundwater. A 100 to 150 ft (30 to 46 m) thick outwash deposit of sand and gravel, occupying a buried valley underlying Chippewa Creek, forms a highly permeable aquifer for agricultural, municipal, and domestic purposes. In some areas bedrock aquifers, mostly composed of sandstone of Pennsylvanian and Mississippian age, are used for industrial and domestic purposes. Mean transmissivity of the outwash aquifer is 25,000 gpd/ft (310 mVday). The hydraulic conductivity of the aquifer has a mean value of 250 gpd/ft2 (10 m/day). The total calculated volume of annual net recharge is 4.2 x 108 ft3 (1.2 107 m3) and the mean specific capacity of the wells completed in aquifer is 5.0 gpm/ft (1.03 1/sec/m). The groundwater quality is suitable for drinking and agricultural use and contains mostly Ca++, Na+, K+ and HCO3~ ions. Groundwater pollution potential of the study area was evaluated using DRASTIC. Chippewa Creek watershed lies within the Glaciated Central Ground Water Region. Seven mappable units from DRASTIC were defined in the study area based on seven hydrogeologic settings. The units are: 1) 7Aa, glacial till over bedded sedimentary rocks (DRASTIC designation); 2) 7Ad, glacial till over sandstone; 3) 7Af, sand and gravel interbedded in glacial till; 4) 7Ba, outwash; 5) 7D, buried valley; 6) 7Eb, alluvium without overbank deposits; 7) 7Ec, alluvium over bedded sedimentary rocks. The outwash aquifer has a moderate to high pollution potential and the underlying sandstone and shale deposits show relatively low pollution potentials. The alluvium in valleys exhibits moderately high susceptibility to contamination