3,939 research outputs found
Uniform Statistical Information Questionnaire: 1975, A Supplementary Report
https://egrove.olemiss.edu/aicpa_exam/1224/thumbnail.jp
Uniform Statistical Information Questionnaire : 1980, A Supplementary Report
https://egrove.olemiss.edu/aicpa_exam/1222/thumbnail.jp
MU2 and HP1a Regulate the Recognition of Double Strand Breaks in Drosophila melanogaster
Chromatin structure regulates the dynamics of the recognition and repair of DNA double strand breaks; open chromatin enhances the recruitment of DNA damage response factors, while compact chromatin is refractory to the assembly of radiation-induced repair foci. MU2, an orthologue of human MDC1, a scaffold for ionizing radiation-induced repair foci, is a widely distributed chromosomal protein in Drosophila melanogaster that moves to DNA repair foci after irradiation. Here we show using yeast 2 hybrid screens and co-immunoprecipitation that MU2 binds the chromoshadow domain of the heterochromatin protein HP1 in untreated cells. We asked what role HP1 plays in the formation of repair foci and cell cycle control in response to DNA damage. After irradiation repair foci form in heterochromatin but are shunted to the edge of heterochromatic regions an HP1-dependent manner, suggesting compartmentalized repair. Hydroxyurea-induced repair foci that form at collapsed replication forks, however, remain in the heterochromatic compartment. HP1a depletion in irradiated imaginal disc cells increases apoptosis and disrupts G2/M arrest. Further, cells irradiated in mitosis produced more and brighter repair foci than to cells irradiated during interphase. Thus, the interplay between MU2 and HP1a is dynamic and may be different in euchromatin and heterochromatin during DNA break recognition and repair
An experimental and theoretical study of transient negative ions in Mg, Zn, Cd and Hg
A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states
A positron trap and beam apparatus for atomic and molecular scattering experiments
An instrument has been designed and constructed to provide new insights into fundamental, low energy positron scattering processes. The design is based on the Surko trap system and produces a pulsed positron beam with an energy resolution of as good as 54 meV. The design and operation of the apparatus is explained, while the first experimental results from this apparatus have been demonstrated in recent publications.The authors would
like to acknowledge the Australian Research Council for
funding support, through the Centre of Excellence program,
as well as the LIEF and Discovery funding programs
Ovogénesis y formación de la puesta de los peces invasores Pterois miles y Pterois volitans
The Indo-Pacific lionfish, Pterois miles and P. volitans, have recently invaded the U.S. east coast and the Caribbean and pose a significant threat to native reef fish communities. Few studies have documented reproduction in pteroines from the Indo-Pacific. This study provides a description of oogenesis and spawn formation in P. miles and P. volitans collected from offshore waters of North Carolina, U.S.A and the Bahamas. Using histological and laboratory observations, we found no differences in reproductive biology between P. miles and P. volitans. These lionfish spawn buoyant eggs that are encased in a hollow mass of mucus produced by specialized secretory cells of the ovarian wall complex. Oocytes develop on highly vascularized peduncles with all oocyte stages present in the ovary of spawning females and the most mature oocytes placed terminally, near the ovarian lumen. Given these ovarian characteristics, these lionfish are asynchronous, indeterminate batch spawners and are thus capable of sustained reproduction throughout the year when conditions are suitable. This mode of reproduction could have contributed to the recent and rapid establishment of these lionfish in the northwestern Atlantic and Caribbean.Los peces Indo-PacÃficos, Pterois miles y P. volitans, han invadido recientemente la costa este de los Estados Unidos y el Caribe y representan una significativa amenaza a las comunidades nativas de peces coralinos. Unos pocos estudios han documentado la reproducción en peces de la subfamilia Pteroinae del Indo-PacÃfico. Este estudio presenta la descripción de la ovogénesis y la formación de puesta en P. miles y P. volitans recolectados desde aguas a mar abierto de Carolina del Norte, U.S.A, y las Bahamas. Mediante el uso de observaciones histológicas y de laboratorio, encontramos que no habÃa diferencias en la biologÃa reproductiva entre P. miles y P. volitans. Estas especies desovan huevos flotantes que están encerrados en una masa hueca de moco producida por células secretoras especializadas del complejo de la pared del ovario. Los ovocitos se desarrollan en pedúnculos altamente especializados, estando todos los estadios de los ovocitos presentes en el ovario de las hembras en puesta, y los ovocitos más maduros se localizan en la zona terminal, cerca del lumen del ovario. Dadas estas caracterÃsticas del ovario, estas especies son asincrónicas, ponedores secuenciales indeterminados y son, por tanto, capaces de tener una reproducción sostenida a lo largo del año cuando las condiciones son adecuadas. Este modo de reproducción podrÃa haber contribuido al rápido reciente establecimiento de estas especies en el noroeste del Atlántico y Caribe
A Multicenter Study Of Students Sensitivity To Screen-Update Delay
In a climate of shrinking educational budgets, online learning courses offer many advantages; however there are several possible problems associated with electronic learning. There may be problems associated with learning style preferences, student apathy, instructional support, accessibility, and problems with technology. This paper examines a technological problem associated with the effects of screen-update-delay and student enjoyment, student self-reported comprehension, and student objective comprehension. In particular, this paper attempts to identify the point at which longer screen updates will be detrimental to the students enjoyment and/or have a significant negative impact on the students self-reported comprehension and retention of material
Recent Decisions
Comments on recent decisions by Robert E. Sullivan, James H. Graham, John E. Savord, Edward A. Mahoney, Jr., and Ronald P. Rejent
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