11,769 research outputs found
The General Electric MOD-1 wind turbine generator program
The design, fabrication, installation and checkout of MOD-1, a megawatt class wind turbine generator which generates utility grade electrical power, is described. A MOD-1/MOD-1A tradeoff study is discussed
The mass and dynamical state of Abell 2218
Abell 2218 is one of a handful of clusters in which X-ray and lensing
analyses of the cluster mass are in strong disagreement. It is also a system
for which X-ray data and radio measurements of the Sunyaev-Zel'dovich decrement
have been combined in an attempt to constrain the Hubble constant. However, in
the absence of reliable information on the temperature structure of the
intracluster gas, most analyses have been carried out under the assumption of
isothermality. We combine X-ray data from the ROSAT PSPC and the ASCA GIS
instruments, enabling us to fit non-isothermal models, and investigate the
impact that this has on the X-ray derived mass and the predicted
Sunyaev-Zel'dovich effect.
We find that a strongly non-isothermal model for the intracluster gas, which
implies a central cusp in the cluster mass distribution, is consistent with the
available X-ray data and compatible with the lensing results. At r<1 arcmin,
there is strong evidence to suggest that the cluster departs from a simple
relaxed model. We analyse the dynamics of the galaxies and find that the
central galaxy velocity dispersion is too high to allow a physical solution for
the galaxy orbits. The quality of the radio and X-ray data do not at present
allow very restrictive constraints to be placed on H_0. It is apparent that
earlier analyses have under-estimated the uncertainties involved. However,
values greater than 50 km/s/Mpc are preferred when lensing constraints are
taken into account.Comment: 16 pages, 9 postscript figures, accepted for publication in MNRA
Latino Outreach Programs: Why They Need to Be Different
As Extension reaches out to first- and second-generation Latinos, changes must be made in the design and delivery of programs. These changes often cause concern among existing audiences and some staff who wonder about the need for them and their impact on programs and Extension\u27s future. Part of the challenge of Extension outreach includes bringing concerned participants and staff along to understand the cultural characteristics of diverse community members and how these affect programming. New approaches do not mean the mission of Extension has changed; they mean that Extension is becoming more capable of serving all audiences
Creating a Georgia Southern Spider Collection: Can DNA Barcoding Help?
With over 280 spider (Araneae) species recorded within the State of Georgia, USA, the need for a well-documented natural history collection with a usable voucher system is critical to continually assess spider diversity and their future ecological impact in this region. Spider identification can be daunting for the inexperienced taxonomist; it is time consuming and sometimes requires destructive procedures. Previous works have successfully used an alternative method, DNA barcoding, to correctly identify spider species while preserving their morphology. This study set forth to create the core of a well-documented spider collection within Georgia Southern University’s Institute for Coastal Plain Science and use DNA barcoding as a diagnostic tool. We collected 334 spiders from varying locations within the Coastal Plain and optimized a DNA extraction protocol from spider legs. Cytochrome C Oxidase Subunit I (COI), the gene commonly used in DNA barcoding, and an additional nuclear gene Histone 3 type A (H3A) were amplified and sequenced from a total of 132 and 150 spiders, respectively. The COI dataset identified 16 families, 33 genera, and 36 different species, while H3A identified 15 families, 23 genera, and 15 species. In addition, based on these gene sequences, we generated phylogenetic inferences of the COI and, when possible, of a concatenated datase
Diversifying the Volunteer Base: Latinos and Volunteerism
Latino adults represent a significant source of potential volunteers for Extension. Gaining their involvement, however, has proven to be a challenge. In 1999, the Oregon 4-H program conducted a series of focus groups to increase understanding of the Latino culture as it relates to volunteerism and to identify practices that would encourage Latino adults to volunteer with mainstream organizations such as Extension. Volunteer managers drawn from a cross section of community organizations composed the focus groups. This article shares the findings gained from the focus group process and discusses the implications of those findings for Extension
Distribution and feeding behavior of early life stages of the northern shrimp, Pandalus borealis, in relation to the spring phytoplankton bloom in the western Gulf of Maine
The northern shrimp Pandalus borealis is a commercially important crustacean found in the deep waters of western Gulf of Maine. In order to develop better fisheries management practices, it is essential to understand variability in P. borealis recruitment. Analysis of samples collected along a coastal transect (during 2005 and 2006), indicate cross-shore distribution of early planktonic larval stages is consistent with observed benthic distribution of ovigerous females. Timing of larval occurrence in relation to the spring phytoplankton bloom suggests that a match/mismatch with abundance of phytoplankton and zooplankton prey may be a primary determinant of recruitment success. Among the potential zooplankton prey, Balanus sp. larvae are predominant during the residence time of P. borealis larvae. Laboratory feeding experiments revealed stage III larvae have higher feeding rates on the diatom Thalassiosira nordenskioeldii than stage I. These results support efforts for coupled physical biological models that will allow testing of recruitment hypotheses
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Beyond Critical Period Learning: Striatal FoxP2 Affects the Active Maintenance of Learned Vocalizations in Adulthood.
In humans, mutations in the transcription factor forkhead box P2 (FOXP2) result in language disorders associated with altered striatal structure. Like speech, birdsong is learned through social interactions during maturational critical periods, and it relies on auditory feedback during initial learning and on-going maintenance. Hearing loss causes learned vocalizations to deteriorate in adult humans and songbirds. In the adult songbird brain, most FoxP2-enriched regions (e.g., cortex, thalamus) show a static expression level, but in the striatal song control nucleus, area X, FoxP2 is regulated by singing and social context: when juveniles and adults sing alone, its levels drop, and songs are more variable. When males sing to females, FoxP2 levels remain high, and songs are relatively stable: this "on-line" regulation implicates FoxP2 in ongoing vocal processes, but its role in the auditory-based maintenance of learned vocalization has not been examined. To test this, we overexpressed FoxP2 in both hearing and deafened adult zebra finches and assessed effects on song sung alone versus songs directed to females. In intact birds singing alone, no changes were detected between songs of males expressing FoxP2 or a GFP construct in area X, consistent with the marked stability of mature song in this species. In contrast, songs of males overexpressing FoxP2 became more variable and were less preferable to females, unlike responses to songs of GFP-expressing control males. In deafened birds, song deteriorated more rapidly following FoxP2 overexpression relative to GFP controls. Together, these experiments suggest that behavior-driven FoxP2 expression and auditory feedback interact to precisely maintain learned vocalizations
Measurement of thermal conductance of multilayer and other insulation materials Final report
Thermal conductance measurements of multilayer, aluminumized polymeric films for space suit insulation material
Cable TV\u27s Must Carry Rules: The Most Restrictive Alternative - \u3cem\u3eQuincy Cable TV, Inc. v. FCC\u3c/em\u3e
This note first argues that the court correctly applied the least scrutinizing first amendment test to the facts of the case and concluded its inquiry after the rules failed that test. Second, this note argues that the FCC, while once on the correct regulatory path regarding cable, erred by not studying the potential impact of cable television on a case by case basis as the FCC had decided to do with competing broadcasters in Carroll Broadcasting, Inc. v. FCC. Third, this note concludes that the Quincy case will benefit cable operators financially and will provide proper protection of cable operators\u27 right of free speech
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