Feasibility model of a high reliability five-year tape transport, volume 2

Analysis of the design features of the modularized tape transport renders a life expectancy in excess of five years. Tests performed on the tape transport were directed toward determining its performance capability. These tests revealed that the tape jitter and skew are in the range achieved by high quality digital tape transports. Guidance of the tape in the lateral sense by the use of the two hybrid crowned rollers proved to be excellent. Tracking was maintained within less than one thousandth inch (approximately 2 micrometers). The guidance capability demonstrated makes possible the achievement of the performance objective of 7.2 x 10 to the 9th power storage capability employing 1500 ft. of one inch wide tape with a packing density of 5,000 bits per inch per track on 80 tracks. Also, the machine showed excellent characteristics operating over a wide range of tape speeds. The basic design concept lends itself to growth and adaptation to a wide range of recorder requirements

Internships: The Nuts And Bolts Of An Effective Program

Braxston Public Engineering and Consulting Group (BPECG) is a nationally known and respected company that is magnate for students who wish to receive a valued internship experience.   Under the able direction of Amy Greene, the work experiences were coordinated during the summer and interns were well paid for their contributions.  The case study chronicles the trials and tribulations faced by a competent, highly energized engineering intern who faces the malaise of an organization that is unprepared to provide a valid learning experience. As the case unfolds, Greene has an Eureka experience and learns from a colleague how interns can and do make vital contributions (ROI’s) to their assigned organizations. Upon reviewing the contributions that interns made in three organizations, she redesigns Braxston’s Internship program, reviews the State University Intern to Work Program that addresses, among many other factors, the internship purpose, supervision, learning objectives,  and intern and employer obligations.  The case includes an Intern Evaluation form and a Memorandum of Understanding (MOU) between the university and the company. Last, the Questions and Instructions provide for focused discussion and analysis and the references enable learners to research the top internship programs in the United States

Children's construction task performance and spatial ability: controlling task complexity and predicting mathematics performance.

This paper presents a methodology to control construction task complexity and examined the relationships between construction performance and spatial and mathematical abilities in children. The study included three groups of children (N = 96); ages 7-8, 10-11, and 13-14 years. Each group constructed seven pre-specified objects. The study replicated and extended previous findings that indicated that the extent of component symmetry and variety, and the number of components for each object and available for selection, significantly predicted construction task difficulty. Results showed that this methodology is a valid and reliable technique for assessing and predicting construction play task difficulty. Furthermore, construction play performance predicted mathematical attainment independently of spatial ability

Plants regenerated from tissue culture contain stable epigenome changes in rice.

Most transgenic crops are produced through tissue culture. The impact of utilizing such methods on the plant epigenome is poorly understood. Here we generated whole-genome, single-nucleotide resolution maps of DNA methylation in several regenerated rice lines. We found that all tested regenerated plants had significant losses of methylation compared to non-regenerated plants. Loss of methylation was largely stable across generations, and certain sites in the genome were particularly susceptible to loss of methylation. Loss of methylation at promoters was associated with deregulated expression of protein-coding genes. Analyses of callus and untransformed plants regenerated from callus indicated that loss of methylation is stochastically induced at the tissue culture step. These changes in methylation may explain a component of somaclonal variation, a phenomenon in which plants derived from tissue culture manifest phenotypic variability. DOI:http://dx.doi.org/10.7554/eLife.00354.001

Drug resistance mutations among antiretroviral-treated female sex workers in Nairobi, Kenya

Antiretroviral drug resistance remains an important and a growing challenge in HIV management as it almost always lead to treatment failure. Sex workers face persistent exposures to the different HIV-1 variants and in turn pose a risk of transmission to the general population and measuring drug resistance in this population may serve as a measure for the risk of transmission of these strains to drug naïve populations. The objective of this study was therefore to determine the pattern and prevalence of HIV-1 drug resistance mutations in a cohort of female sex workers in Nairobi, Kenya. Plasma from 60 female sex workers on antiretroviral treatment for over six months was analyzed by amplification and sequencing of the reverse transcriptase - pol region. Five samples (8.3%) showed antiretroviral resistance-associated mutations. One sample (1.7%) showed mutations conferring resistance only to the NNRTI class, 2 samples (3.3%) showed mutations conferring resistance only to the NRTI class while 2 samples (3.3%) showed mutations conferring resistance to both NRTI and NNRTI classes. Phylogenetic analysis revealed HIV-1 subtype A1 (96.7%) and HIV-1 subtype D (3.3%). The prevalence rate of 8.3% for reverse transcriptase-associated resistance mutations was observed. This is a lower rate than has been reported from studies among antiretroviral (ARV)-treated individuals in the country.Afr J Health Sci. 2013; 26:291-30