4,920 research outputs found
The Functions of the Multiproduct and Rapidly Evolving \u3cem\u3edec-1\u3c/em\u3e Eggshell Gene Are Conserved Between Evolutionarily Distant Species of Drosophila
The Drosophila dec-1 gene encodes multiple proteins that are required for female fertility and proper eggshell morphogenesis. Genetic and immunolocalization data suggest that the different DEC-1 proteins are functionally distinct. To identify regions within the proteins with potential biological significance, we cloned and sequenced the D. yakuba and D. virilis dec-1 homologs. Interspecies comparisons of the predicted translation products revealed rapidly evolving sequences punctuated by blocks of conserved amino acids. Despite extensive amino acid variability, the proteins produced by the different dec-1 homologs were functionally interchangeable. The introduction of transgenes containing either the D. yakuba or the D. virilis dec-1 open reading frames into a D. melanogaster DEC-1 protein null mutant was sufficient to restore female fertility and wild-type eggshell morphology. Normal expression and extracellular processing of the DEC-1 proteins was correlated with the phenotypic rescue. The nature of the conserved features highlighted by the evolutionary comparison and the molecular resemblance of some of these features to those found in other extracellular proteins suggests functional correlates for some of the multiple DEC-1 derivatives
Forest succession in the southern limits of Early Wisconsin glaciation as indicated by a pollen spectrum from Bacon\u27s swamp, Marion county, Indiana
In the past few years, the Botany Department of Buter University has conducted an extensive study of Indiana peat bogs. Such a study will throw much light upon the history of Indiana vegetation. This paper is a portion of the greater survey and describes results from the southernmost bog studied. The name Bacon\u27s Swamp has its origin by common usage of natives of the region. The area is a typical glacial peat bog of the kettle hole type, and is in no sense a swamp
Neuronal Control of Swimming Behavior: Comparison of Vertebrate and Invertebrate Model Systems
Swimming movements in the leech and lamprey are highly analogous, and lack homology. Thus, similarities in mechanisms must arise from convergent evolution rather than from common ancestry. Despite over 40 years of parallel investigations into this annelid and primitive vertebrate, a close comparison of the approaches and results of this research is lacking. The present review evaluates the neural mechanisms underlying swimming in these two animals and describes the many similarities that provide intriguing examples of convergent evolution. Specifically, we discuss swim initiation, maintenance and termination, isolated nervous system preparations, neural-circuitry, central oscillators, intersegmental coupling, phase lags, cycle periods and sensory feedback. Comparative studies between species highlight mechanisms that optimize behavior and allow us a broader understanding of nervous system function
Infusing Free, Hands-On, Interactive Information Technology Into The MIS Curriculum
This paper provides practical suggestions for incorporating free, hands-on interactive information technology (IT) into a business Management Information Systems (MIS) course. This paper focuses on interactive multimedia technologies (such as programs, audio, video, animation, etc.) that can be accessed and used for free (subject to any software license terms). This paper provides specific details about where to access the technology, how it fits into the curriculum and any issues related to installing or using the technology
MODELING FARM AND OFF-FARM ECONOMIC LINKAGES TO ANALYZE THE IMPACTS OF AN AREA-WIDE INSECT MANAGEMENT PROGRAM ON A REGIONAL ECONOMY
This study evaluated the impacts of the boll weevil eradication program at the farm level and on the west Tennessee region. Budgets, an acreage response model, and an input-output model were used to evaluate direct and indirect program impacts. The program generates small but positive economic benefits for the region.Crop Production/Industries,
Bicuspid aortic valve disease
The prevalence of bicuspid aortic valve (BAV) disease is 0.5 - 2% of the population with a 3:1 male predominance. The genetic basis remains unknown although 9% of families have more than one affected individual. Life expectancy in patients with BAV is similar to the general population with a 10-year survival of over 95%. Adverse outcomes are most often due to aortic stenosis late in life, aortic regurgitation in young adulthood or endocarditis in a small number of patients. The BAV syndrome is also associated with an aortopathy characterised by aortic dilation and an increased risk of aortic dissection. Clinical management of patients with a BAV focuses on periodic evaluation of valve function and aortic size, patient education about the expected disease course, prevention of endocarditis and optimal timing of aortic valve replacement for stenosis and/or regurgitation; with concurrent root replacement if aortic dilation (>4.5cm diameter) is present. In addition, aortic root replacement is recommended if aortic diameter exceeds 5.5cm, even if aortic valve function remains normal
James Otto Ricketts to James Ricketts, June 24, 1806
James Otto Ricketts wrote from Bromley, London to James Ricketts, his father, addressed to John Jackson, Esq. near Hammersmith, London. He wrote that the end of the term was coming up and outlined what he had studied. He said that after the term he planned to travel to Hammersmith and wanted to meet his friends and father there. He mentioned Mr. and Mrs. Dean sent their best wishes to their family and the Jacksons.https://digitalcommons.kean.edu/lhc_1800s/1063/thumbnail.jp
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