Albion College

About: Albion College is a education organization based out in Albion, Michigan, United States. It is known for research contribution in the topics: Population & Higher education. The organization has 485 authors who have published 754 publications receiving 20907 citations.

Versatile transcription control based on reversible dCas9 binding

Abstract: The ability to control transcription in a time-dependent manner in vitro promises numerous applications in molecular biology and nanotechnology. Here we demonstrate an approach that enables precise, independent control over the production of multiple RNA transcripts in vitro using single guide RNA (sgRNA)-directed transcription blockades by catalytically dead Streptococcus pyogenes CRISPR-Cas9 enzyme (dCas9). We show that when bound to a DNA template, the dCas9:sgRNA complex forms a robust blockade to transcription by RNA polymerases (RNAPs) from bacteriophages SP6, T3, and T7 (>99.5% efficiency), and a partial blockade to transcription by Escherichia coli RNAP (∼70% efficiency). We find that all three bacteriophage RNAPs dissociate from the DNA template upon encountering the dCas9 blockade, while E. coli RNAP stays bound for at least the 90-min duration of our experiments. The blockade maintains >95% efficiency when four mismatches are introduced into the 5' end of the sgRNA target sequence. Notably, when using such a mismatched blockade, production of specific RNA species can be activated on demand by addition of a double-stranded competitor DNA perfectly matching the sgRNA. This strategy enables the independent production of multiple RNA species in a temporally controlled fashion from the same DNA template, demonstrating a new approach for transcription control.

Induction of Cellular Growth by the Axon Guidance Regulators Netrin A and Semaphorin-1a

Abstract: Although neurite outgrowth has been linked to axon guidance regulators, the effects of guidance molecules on cellular growth are not well understood. Use of the Drosophila wing imaginal disc, an epithelial tissue and a well-characterized system for analysis of cellular growth regulation, permits analysis of the impacts of guidance molecules on cellular growth in a setting in which axon guidance is not a confounding factor. In this investigation, the impacts of Netrin A (NetA) and Semaphorin-1a (Sema1a) signaling on cellular growth are examined during wing development. Levels of these genes were modulated in somatic clones in the developing wing disc, and clone areas, as well as individual sizes of clonal cells were assessed. NetA and Sema1a signaling were found to induce cellular growth in these assays. Furthermore, immunohistochemical analyses indicated that NetA and Sema1a signaling induce expression of several growth regulators, including myc, cycD, cdk4, PCNA, and MapK in the wing disc. These data illustrate that NetA and Sema1a can specifically promote growth through induction of key cellular growth regulators. The abilities of NetA and Sema1a to regulate cellular growth are likely critical to their functions in both nervous system development and oncogenesis.

Rotating Dual-Wire Beam Profile Monitor Optimized for Use in Merged-Beams Experiments

Abstract: A rotating dual-wire beam profile monitor based upon a National Electrostatics Corporation Model BPM80 beam profile monitor is described. The device can measure beam profiles in two perpendicular directions (horizontal and vertical) in each of two pseudoplanes that are situated along the beam axis and are separated by a distance of 5.4 cm. The output signal from the device is analyzed in real time to yield horizontal and vertical beam profiles and to calculate the divergence of a particle beam that traverses the device. This set-up is well-suited for merged-beams experiments where one beam is tuned to saved profiles from a second beam in order to minimize the merge angle and beam divergences while maximizing the beam–beam overlaps.

In Their Own Words: Consequences 0f Child Labor in Urban Nigeria

Abstract: This paper utilizes a 2002 datasets gathered through interviews with 1,535 children (aged 8-14 years) and their parents in urban Nigeria to examine the dangers and hazards reported by children who work in the urban economy. Findings indicate that slightly over half of interviewed child laborers are female; they begin work as early as age 7; and work for an average of 4 hours a day in order to contribute financially to the sustenance of the family; and to acquire training needed in future occupations. The children come mostly from large households of about 6 persons, where many of their parents have low levels of education, income, and occupational statuses. Furthermore, because the sample is urban based, children come mostly from nuclear and monogamous households. A significant percentage of working children are involved in motor accidents, face attempted kidnapping, rape, and sexual molestation. Many are also invited by gangsters to participate in robbery and anti-social activities. Others suffer from physical exhaustion and pains due to frequent long walks. These health problems have detrimental effects on children's school attendance, punctuality, school performance, and leisure time. This study has policy implications for regulating child labor in Nigeria.

Ion–atom merged-beams measurements

Abstract: The ion–atom merged-beams apparatus at Oak Ridge National Laboratory measures benchmark total charge-transfer cross sections for a variety of multicharged ions with atomic H from keV/u down to meV/u center-of-mass collision energies. The apparatus has recently been upgraded and moved to the new high voltage platform where a permanent magnet ECR ion source provides intense high-velocity ion beams. Upgrades to the merged-beams apparatus include more accurate beam profiles and a shortened merge path to increase the angular acceptance of the apparatus. An observed factor of four decrease in the angular divergence of the ion beam translates into access to lower collision energies with higher resolution. The higher velocity ion beams will enable charge transfer measurements with heavier ions, and measurements with both H and D at eV/u energies and below to directly observe the isotope effect.