2,900 research outputs found
Branching Out to Meet the Needs of Our Students: A Model for Oral Communication Assessment and Curriculum Programs
Two of the multiple primary tasks facing post-secondary institutions across the country are revisiting and revitalizing general education or core programs and developing appropriate techniques for assessing the value of these programs. Following years of development and refinement, Western Carolina University has created an oral communication general education program that not only meets the needs of individual students, but also encouraged consistency across the curriculum emphasizing and assessing the skills learned in the basic course. We have answered the call for revisitation and reform regarding the best pedagogical and epistemological strategies for developing competent communicators, and our results have been positive. This article presents the development and implementation of this program
An investigation into the feasibility of myoglobin-based single-electron transistors
Myoglobin single-electron transistors were investigated using nanometer- gap
platinum electrodes fabricated by electromigration at cryogenic temperatures.
Apomyoglobin (myoglobin without heme group) was used as a reference. The
results suggest single electron transport is mediated by resonant tunneling
with the electronic and vibrational levels of the heme group in a single
protein. They also represent a proof-of-principle that proteins with redox
centers across nanometer-gap electrodes can be utilized to fabricate
single-electron transistors. The protein orientation and conformation may
significantly affect the conductance of these devices. Future improvements in
device reproducibility and yield will require control of these factors
Human Immunodeficiency Virus and Hepatitis C Virus Co-infection in Cameroon: Investigation of the Genetic Diversity and Virulent Circulating Strains
Background: RNA virus infections represent a significant cause of illness and death in vertebrates. Specifically in humans, RNA viruses are responsible for a wide range of acute, chronic, emerging and re-emerging infections. HIV and HCV rank as some of the most severe RNA viruse infections facing Africa. Methods: To determine genotypes and subtypes of HIV and HCV among co-infected patients in Cameroon, viral RNA was isolated from HIV/HCV co-infected individuals, in Douala, Cameroon. A total of 36 HIV/HCV co-infected isolates (22 from volunteer blood donors and 14 from people living with HIV/AIDS not yet on antiretroviral treatment) were analyzed using molecular biology techniques that involved RT-PCR, gene/TOPO cloning, DNA sequencing, and bioinformatics tools for sequence management and analysis. Epidemiological data were examined as well.Results: Results show that HIV strains isolated belong to the circulating recombinant forms CRF02_AG, whereas HCV isolates from Cameroon belong to genotypes 1, 2, and 4. The corresponding HCV subtypes investigated were 1a, 1b, 1c, 2a, 2c, 2k, and 4a. Subtypes 1a and 1b, most frequently found in developed countries, also circulate in Cameroon. Epidemiologic data show that HIV/HCV co-infected patients are older than HIVmono-infected patients.Conclusions: These results indicate that HIV/HCV co-infection represent a significant threat in Cameroon. There is evidence of genetic diversity of HIV and HCV; virulent hepatitis C virus subtypes 1a and 1b circulate in Cameroon. An epidemiological and molecular database on HIV and HCV is necessary for the development of further intervention in Cameroon as an imperative for monitoring disease progression.Key words: HIV; HCV; Co-infection ; Genotypes ; Virulent
On Spacetimes with Constant Scalar Invariants
We study Lorentzian spacetimes for which all scalar invariants constructed
from the Riemann tensor and its covariant derivatives are constant (
spacetimes). We obtain a number of general results in arbitrary dimensions. We
study and construct warped product spacetimes and higher-dimensional
Kundt spacetimes. We show how these spacetimes can be constructed from
locally homogeneous spaces and spacetimes. The results suggest a number
of conjectures. In particular, it is plausible that for spacetimes that
are not locally homogeneous the Weyl type is , , or , with any
boost weight zero components being constant. We then consider the
four-dimensional spacetimes in more detail. We show that there are severe
constraints on these spacetimes, and we argue that it is plausible that they
are either locally homogeneous or that the spacetime necessarily belongs to the
Kundt class of spacetimes, all of which are constructed. The
four-dimensional results lend support to the conjectures in higher dimensions.Comment: 25 pages, 1 figure, v2: minor changes throughou
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