2,576 research outputs found
Genome transcription/translation of segmented, negative-strand RNA viruses
The requirements for alignment of capped RNA leader sequences along the viral genome during influenza transcription initiation (“cap-snatching”) have long been an enigma. Previous work on Tomato spotted wilt virus (TSWV) transcription initiation has revealed that this virus displays a preference for leaders with increasing base complementarity to the 3'-ultimate residues of the viral RNA template. Assuming that cap-snatching is a highly conserved mechanism, it is tempting to speculate that the findings for TSWV apply to all segmented negative RNA viruses. The research in this thesis aimed to analyze whether similar cap donor requirements applied for Influenza A virus transcription initiation as compared to what has been found for TSWV. Indeed, in vitro studies demonstrated that influenza transcriptase prefers multiple base-pairing capped leaders. Additionally, the occurrence of “prime-and-realign” during influenza transcription initiation was observed, as well as internal priming at the 3'-penultimate viral residue. The in vitro findings were confirmed by similar studies performed during influenza infection of cell cultures. Whereas transcription initiation of TSWV has been relatively well studied, transcription termination has not. It is postulated that transcription termination/translation is triggered by the formation of a hairpin structure. In cell experiments support a role of the TSWV hairpin structure in translation.</p
Two- versus three-dimensional connectivity testing of first-order queries to semi-algebraic sets
This paper addresses the question whether one can determine the connectivity
of a semi-algebraic set in three dimensions by testing the connectivity of a
finite number of two-dimensional ``samples'' of the set, where these samples
are defined by first-order queries. The question is answered negatively for two
classes of first-order queries: cartesian-product-free, and positive one-pass.Comment: corrected minor confusion in Proof of Theorem
Charge Transport Properties of a Metal-free Phthalocyanine Discotic Liquid Crystal
Discotic liquid crystals can self-align to form one-dimensional
semiconducting wires, many tens of microns long. In this letter, we describe
the preparation of semiconducting films where the stacking direction of the
disc-like molecules is perpendicular to the substrate surface. We present
measurements of the charge carrier mobility, applying temperature-dependent
time-of-flight transient photoconductivity, space-charge limited current
measurements, and field-effect mobility measurements. We provide experimental
verification of the highly anisotropic nature of semiconducting films of
discotic liquid crystals, with charge carrier mobilities of up to
2.8x10cm/Vs. These properties make discotics an interesting choice
for applications such as organic photovoltaics.Comment: 5 pages, 5 figure
The Senior Housing Shuffle:Connecting Public Policy To Universal Design, Sustainability, Health Management, And Aging In Place
Having faced the turbulent waters of uncertainty connected with the underfunding of human service and health management programs before, Judy Jones, in this two part case study, is excited to learn of a major historical restoration in Uptown — a neighborhood of rich historical heritage and architecture which, over the decades, had fallen into disrepair and instability. Old Emory School was to be restored for use as a new senior housing facility by Preservation Incorporated. She knew that realities often fail to measure up to expectations in housing accessibility, affordability, safety, and health care management for the residents, and this was the situation she faced once more. Common managerial and housing related problems are encountered and Judy reflects on the advantages of a built environment that uses universal design principles and wonders why real estate and commercial developers, architects, and urban planners are not more sensitive to these orientations. Based on experience, common housing shortcomings are identified and their relationship to aging in place, sustainability, and selected titles of the Americans with Disability Act, 1990 (ADA, 1990), are explored
Dissimilar response of plant and soil biota communities to long-term nutrient adition in grasslands
The long-term effect of fertilizers on plant diversity and productivity is well known, but long-term effects on soil biota communities have received relatively little attention. Here, we used an exceptional long-lasting (>40 years) grassland fertilization experiment to investigate the long-term effect of Ca, N, PK, and NPK addition on the productivity and diversity of both vegetation and soil biota. Whereas plant diversity increased by liming and decreased by N and NPK, the diversity of nematodes, collembolans, mites, and enchytraeids increased by N, PK, or NPK. Fertilization with NPK and PK increased plant biomass and biomass of enchytraeids and collembolans. Biomass of nematodes and earthworms increased by liming. Our results suggest that soil diversity might be driven by plant productivity rather than by plant diversity. This may imply that the selection of measures for restoring or conserving plant diversity may decrease soil biota diversity. This needs to be tested in future experiment
Eupsychian Management: Organizational Change, Behavior, Motivation, And Trust
In Part 1 of this real-life incident, Professor Carson is teaching the customary material associated with the multiple theories of leadership, motivation, and organizational behavior. He deviates slightly from the way he normally presents these standard concepts and theories and divulges the concept of Eupsychian Management — a culture in which self-actualizing people behave in ways where trust begets trust and work is viewed as natural as play or rest. The class is given the following website www.interpolis.nl which demonstrates how the built environment of Interpolis relates to its organizational culture and behavior. In Part 2, the content of a personal interview that he conducted in Tilburg, The Netherlands — the home of Interpolis is elaborated. A new organizational culture based on “trust” — both of employees and customers is revealed. The end performance results and the productivity metrics are unbelievably high. The reader is challenged to address the content of seven penetrating questions and instructions which are part of the learning module; then, is asked to complete the case log and administrative journal entry
Large electronic bandwidth in solution-processable pyrene crystals: The role of close-packed crystal structure
We examine the interdependence of structural and electronic properties of two
substituted pyrene crystals by means of combined spectroscopic probes and
density-functional theory calculations. One derivative features n-hexyl side
groups, while the other one contains branched silanyl groups. Both derivatives
form triclinic crystal structures when grown from solution, but the electronic
dispersion behavior is significantly different due to differences in
- overlap along the crystal axis. Both systems display dispersion
of 0.40-0.45 eV in the valence band, suggesting a high intrinsic hole mobility.
However, the dispersion is primarily along the a-axis in the
silanyl-substituted derivative, but less aligned with this crystal axis in the
hexyl-substituted material. This is a direct consequence of the diferences in
co-facial electron overlap revealed by the crystallographic studies. We
find that photophysical defects, ascribed to excimer-like states, point to the
importance of localized trap states. Substituted pyrenes are useful model
systems to unravel the interplay of crystal structure and electronic properties
in organic semiconductors.Comment: 25 pages, 8 figure
"Grass" By Any Other Name - Xeriscaping And Sustainability
With water conservation and use policy considered to be among the greatest challenges facing contemporary society, this case takes on the enduring issues associated with water and how it impacts urban planning, land use, water conservation, economic development, and sustainability. Conflicted on the uses of natural and artificial turf, Jerard Leon, director of Blue Havens Planning Commission recommends that Joseph Teaberry, landscape architect, contact a premier program on xeriscape in the United States the Southern Nevada Water Authority (SNWA). Teaberry prepares for an in-depth, structured interview with Doug Bennett, conservation manager of SNWA. He reviews the relevant academic and professional literature on the hydrologic cycle, and the economics and geological concerns that affect water use policy, including the meaning of Water quality, Watershed, and the sundry metrics used to assess water quality under the Clean Water Act, 1972. As the structured interview reveals, Teaberry learns about the history of water policy in the Colorado Basin, the multiple uses and costs associated with water consumption in the SNWA, and the conservation practices and water policy pricing policies and how they impact water utilization. In the final analysis, Teaberry discusses the various strategic management practices employed by SNWA and their attendant efficacies, successes/failures pertaining to water policy education, pricing, inducement, enforcement, and the future water policy concerns. The case has several take-away points associated with xeriscape policy, followed by six poignant questions that stimulate broad discussion on the general areas of water resource policy
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