Behavioral and cellular protection of rat dopaminergic neurons by an adenoviral vector encoding glial cell line-derived neurotrophic factor

Consanguineous marriages are strongly preferred in much of West and South Asia. This paper examines the prevalence and sociodemographic correlates of consanguineous unions in Pakistan using local and national data. Information from 1011 ever-married women living in four multi-ethnic and multi-lingual squatter settlements of Karachi, the main commercial centre of the country, are compared with data from the national 1990/91 Pakistan Demographic and Health Survey (PDHS), based on information provided by 6611 women. Both sets of results indicate that approximately 60% of marriages were consanguineous, over 80% of which were between first cousins. The mean coefficients of inbreeding (F) in the present generation were 0.0316 and 0.0331 for the Karachi and PDHS data respectively. In both surveys the prevalence of consanguineous unions appeared to be unchanged over the past three to four decades. Consanguineous unions were more common among women who were illiterate or had only primary level education, were first or second generation migrants from rural areas of Pakistan or, in the PDHS, lived in rural areas, and whose parents were also consanguineously married.     

Cascade of Peritectic Reactions in the B-Fe-U System

The solidification paths for UFeB₄, UFe₃B₂ and UFe₄B, ternary compounds, situated along the U:(Fe,B) = 1:5 line in the B-Fe-U phase diagram, are proposed based on x-ray powder diffraction measurements, differential thermal analysis, heating curves and scanning electron microscopy observations complemented with energy and wavelength dispersive x-ray spectroscopies. The compounds melt incongruently and are formed by peritectic reactions. The present work demonstrates the existence of a cascade of peritectic reactions along the U:(Fe,B) = 1:5 composition line, establishes peritectic temperatures and proposes an isopleth diagram along this line.     

Quantitative submonolayer spatial mapping of Arg-Gly-Asp-containing peptide organomercaptan gradients on gold with matrix-assisted laser desorption/ionization mass spectrometry

Peptides containing the tripeptide sequence Arg-Gly-Asp (RGD) have the ability to bind to members of the integrin superfamily of cell-surface receptors and direct cellular adhesion and haptotaxis. The goal of this work is the development of a rapid and effective method for the quantitative submonolayer spatial composition mapping of surfaces displaying molecular assemblies of RGD-containing organomercaptan peptides on a Au surface using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS). Quantitation of the RGD peptide is achieved by determining the peak intensity of the protonated molecular ion, (M + H)+, relative to the (M + H)+ peak for an internal standard, which is similar chemically but with glutamic acid (E) substituted for aspartic acid (D). Using optimized sample preparation procedures, a bilinear calibration was obtained between the quantitative peak intensity ratio and the mole fraction of the RGD-containing peptide. Quantitative compositions were determined with relative standard deviations of <10%, even in the presence of 10x spot-to-spot variations in the absolute signal intensities, by using this internal standard approach. This MALDI-MS quantitative analysis method was employed to probe variable-width two-component counterpropagating electrochemically generated gradients of the two peptides, prepared by coupling in-plane electrochemical potential gradients with the electrosorption reactions of organothiols to vary the composition laterally. The measured lateral composition profiles match the quasi-linear potential gradient model and yield profiles that overlap to a high degree of fidelity in potential space. Thus, MALDI-MS spatial composition mapping should become a powerful tool for the preparation of designed surfaces facilitating the study of cellular adhesion and motility and cell-cell interactions.     

Microfluidic separation and gateable fraction collection for mass-limited samples

Integrating multiple analytical processes into microfluidic devices is an important research area required for a variety of microchip-based analyses. A microfluidic system is described that achieves preparative separations by intelligent fraction collection of attomole quantities of sample. The device consists of a main microfluidic channel used to perform electrophoresis, which is interconnected at 90 degrees to two vertically displaced channels via a nanocapillary array membrane. The membrane interconnect contains nanometer-diameter pores that provide fluidic communication between the channels. Sample injection and analyte collection are controlled by application of an electrical bias between the microfluidic channels across the nanocapillary array. After the separation, the automated transfer of the FITC-labeled Arg, Gln, and Gly bands occurs; a fluorescence detector located at the separation/collection channel interconnect is used to generate a triggering signal that initiates suitable voltages to allow near-quantitative transfer of analyte from the separation channel to the second fluidic layer. The ability to achieve such sample manipulations from mass-limited samples enables a variety of postseparation processing events.     

An electrochemical and magnetic approach for /H2SO4/HNO3/chitosan functionalized multi-wall carbon nanotubes stable solutions

Journal of Materials Science: Materials in Electronics - The aim of the research was to evaluate the effects of sulfonitric and CS (CS) treatment in multilayer carbon nanotubes (MWCNT) on their...     

Big government projects: which are successful and why?

From time to time, the U.S. government has initiated a particularly large, ambitious program, not as part of the normal R&D process, which tries to anticipate future needs, but in direct response to an immediate known national need. Such programs began with the identification of a compelling goal, then created and applied knowledge and expertise for the purpose of achieving it. In some cases, this approach led to remarkably successful accomplishments for the United States and at the same time gave a very large impetus to both the application and development of technology. There are two apparent reasons for the technological benefit. First, the suitability of the related research and development was guaranteed by its direct association with the goal, so the problem of agreeing on allocation criteria was avoided. And second, having the stated goal constantly in view made it safer to make larger investments, perform bolder research and development activities, and generally surpass in scope and speed the accomplishments that would have resulted from incremental, ad hoc activities. It is natural to ask what factors made these programs successful. One characteristic of these successful U.S. programs is that they call on the utmost creative capability of the nation to accomplish a task of great importance to the country. The author considers the history of these programs, the manner in which they were accomplished, how each one was conceived, how it was conducted, and how it advanced the state of society through technology     

Optimal Equalization of Distortions due to Group Delay Ripples of Chirped Fiber Bragg Gratings (CFBG)

We present a closed solution for an optimal equalizer which compensates for signal distortions caused by group delay ripples in chirped fiber Bragg gratings (CFBG) employed for dispersion compensation in optical communication systems. The theory is verified with the help of group delay measurement results of a dispersion compensating CFBG and the improvements achieved by the equalizer are presented on the basis of simulation results.     

Stochastic modeling for characterisation of biofilm development with discrete detachment events (sloughing).

The monitoring of biofilm development at a small-scale is often observed to be a stochastic process. This raises important issues concerning the reproducibility of biofilm growth monitoring experiments. By realising that there are limits to the latter, a model of biofilm accumulation curves that takes into account the dynamics of seemingly random fluctuations resulting from sloughing events is proposed. The model is derived from a stochastic differential equation (SDE) based on the logistic equation, adding a stochastic term for the sloughing events and measurement noise. Experimental light absorbance data that correlate with biofilm biomass obtained from the development of phototrophic biofilms are analysed to illustrate the use of SDE modeling.     

The Responsive Workbench: a virtual work environment

In this virtual environment, customized scientific visualization tools offer specialists new ways to work cooperatively, which opens the door to more comprehensive analysis and, perhaps, reduced costs. Implementing the Responsive Workbench required close attention to several important elements: its components, a typical setup, the user interface, feedback speed and real-time rendering