357 research outputs found

    Computer simulation of the heavy-duty turbo-compounded diesel cycle for studies of engine efficiency and performance

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    Reductions in heat loss at appropriate points in the diesel engine which result in substantially increased exhaust enthalpy were shown. The concepts for this increased enthalpy are the turbocharged, turbocompounded diesel engine cycle. A computer simulation of the heavy duty turbocharged turbo-compounded diesel engine system was undertaken. This allows the definition of the tradeoffs which are associated with the introduction of ceramic materials in various parts of the total engine system, and the study of system optimization. The basic assumptions and the mathematical relationships used in the simulation of the model engine are described

    The Business of Law: Evolution of the Legal Services Market

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    The legal services market is changing. This change has been driven by various factors through the years: expansion of in-house legal departments, globalization (through mergers and outsourcing), technological advances, and the rise of alternative legal service providers. This paper explores these factors in isolation—i.e., discussing each factor separately and distinctly from other factors. Then, this paper seeks to understand these factors together, as products of a legal services market that is evolving from the growth stage into the mature stage. Part I summarizes the early history of law firms, including the rise of the Cravath System through the Golden Era of the 1960s. Part II examines several factors affecting the legal services market, specifically: expansion of in-house legal departments, globalization (through mergers and outsourcing), technological advances, and the rise of alternative legal service providers. Finally, Part III discusses how these factors can also be understood together, as products of a maturing legal services market

    Seasonal changes in patterns of gene expression in avian song control brain regions.

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Photoperiod and hormonal cues drive dramatic seasonal changes in structure and function of the avian song control system. Little is known, however, about the patterns of gene expression associated with seasonal changes. Here we address this issue by altering the hormonal and photoperiodic conditions in seasonally-breeding Gambel's white-crowned sparrows and extracting RNA from the telencephalic song control nuclei HVC and RA across multiple time points that capture different stages of growth and regression. We chose HVC and RA because while both nuclei change in volume across seasons, the cellular mechanisms underlying these changes differ. We thus hypothesized that different genes would be expressed between HVC and RA. We tested this by using the extracted RNA to perform a cDNA microarray hybridization developed by the SoNG initiative. We then validated these results using qRT-PCR. We found that 363 genes varied by more than 1.5 fold (>log(2) 0.585) in expression in HVC and/or RA. Supporting our hypothesis, only 59 of these 363 genes were found to vary in both nuclei, while 132 gene expression changes were HVC specific and 172 were RA specific. We then assigned many of these genes to functional categories relevant to the different mechanisms underlying seasonal change in HVC and RA, including neurogenesis, apoptosis, cell growth, dendrite arborization and axonal growth, angiogenesis, endocrinology, growth factors, and electrophysiology. This revealed categorical differences in the kinds of genes regulated in HVC and RA. These results show that different molecular programs underlie seasonal changes in HVC and RA, and that gene expression is time specific across different reproductive conditions. Our results provide insights into the complex molecular pathways that underlie adult neural plasticity

    A new marker based on the avian spindlin gene that is able to sex most birds, including species problematic to sex with CHD markers

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    We have developed a new marker (Z43B) that can be successfully used to identify the sex of most birds (69%), including species difficult or impossible to sex with other markers. We utilized the zebra finch Taeniopygia guttata EST microsatellite sequence (CK309496) which displays sequence homology to the 5′ untranslated region (UTR) of the avian spindlin gene. This gene is known to be present on the Z and W chromosomes. To maximize cross-species utility, the primer set was designed from a consensus sequence created from homologs of CK309496 that were isolated from multiple distantly related species. Both the forward and reverse primer sequences were 100% identical to 14 avian species, including the Z chromosome of eight species and the chicken Gallus gallus W chromosome, as well as the saltwater crocodile Crocodylus porosus. The Z43B primer set was assessed by genotyping individuals of known sex belonging to 61 non-ratite species and a single ratite. The Z and W amplicons differed in size making it possible to distinguish between males (ZZ) and females (ZW) for the majority (69%) of non-ratite species tested, comprising 10 orders of birds. We predict that this marker will be useful for obtaining sex-typing data for ca 6,869 species of birds (69% of non-ratites but not galliforms). A wide range of species could be sex-typed including passerines, shorebirds, eagles, falcons, bee-eaters, cranes, shags, parrots, penguins, ducks, and a ratite species, the brown kiwi, Apteryx australis. Those species sexed include species impossible or problematic to sex-type with other markers (magpie, albatross, petrel, eagle, falcon, crane, and penguin species)

    The Songbird Neurogenomics (SoNG) Initiative: Community-based tools and strategies for study of brain gene function and evolution

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    BACKGROUND: Songbirds hold great promise for biomedical, environmental and evolutionary research. A complete draft sequence of the zebra finch genome is imminent, yet a need remains for application of genomic resources within a research community traditionally focused on ethology and neurobiological methods. In response, we developed a core set of genomic tools and a novel collaborative strategy to probe gene expression in diverse songbird species and natural contexts. RESULTS: We end-sequenced cDNAs from zebra finch brain and incorporated additional sequences from community sources into a database of 86,784 high quality reads. These assembled into 31,658 non-redundant contigs and singletons, which we annotated via BLAST search of chicken and human databases. The results are publicly available in the ESTIMA:Songbird database. We produced a spotted cDNA microarray with 20,160 addresses representing 17,214 non-redundant products of an estimated 11,500–15,000 genes, validating it by analysis of immediate-early gene (zenk) gene activation following song exposure and by demonstrating effective cross hybridization to genomic DNAs of other songbird species in the Passerida Parvorder. Our assembly was also used in the design of the "Lund-zfa" Affymetrix array representing ~22,000 non-redundant sequences. When the two arrays were hybridized to cDNAs from the same set of male and female zebra finch brain samples, both arrays detected a common set of regulated transcripts with a Pearson correlation coefficient of 0.895. To stimulate use of these resources by the songbird research community and to maintain consistent technical standards, we devised a "Community Collaboration" mechanism whereby individual birdsong researchers develop experiments and provide tissues, but a single individual in the community is responsible for all RNA extractions, labelling and microarray hybridizations. CONCLUSION: Immediately, these results set the foundation for a coordinated set of 25 planned experiments by 16 research groups probing fundamental links between genome, brain, evolution and behavior in songbirds. Energetic application of genomic resources to research using songbirds should help illuminate how complex neural and behavioral traits emerge and evolve

    Flumes and weirs

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    Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Long-throated flumes and broad-crested weirs provide a practical, low-cost, flexible means of measuring open-channel flows in new and existing irrigation systems and have distinct advantages over other flume and weir devices. Application of these flumes and weirs has been greatly facilitated by the 1999 release of the WinFlume software used to design and calibrate these structures, and the recent publication of Water Measurement with Flumes and Weirs, a text providing comprehensive information on design, calibration, construction, and operation issues. The primary advantages of these flumes and weirs are that they can be custom-designed to satisfy unique operational and site requirements, and they can be computer calibrated without the need for laboratory testing. In addition, these devices are easily and economically constructed, and a number of commercially built, pre-calibrated devices are available. This paper and accompanying poster describe the use of the WinFlume software and present examples to illustrate application to a range of situations, including various flow rates, channel types, and construction techniques

    A comparison of functional outcomes in patients undergoing revision arthroscopic repair of massive rotator cuff tears with and without arthroscopic suprascapular nerve release

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    PURPOSE: This study was designed to compare functional outcomes in patients undergoing revision repair of massive rotator cuff tears (retracted medial to the glenoid) with Goutallier Grade 4 atrophy and concomitant release of the suprascapular nerve to a similar group of patients with Grade 3 atrophy undergoing revision rotator cuff repair (RTCR) without nerve release. We hypothesized that patients undergoing nerve release would have more favorable functional outcomes as measured by the Modified University of California at Los Angeles shoulder rating scale (UCLA). PATIENTS AND METHODS: Twenty-two patients underwent revision repair of massive rotator cuff tears with release of the suprascapular nerve at the suprascapular notch. We compared total preoperative, postoperative, and change in UCLA score in these patients to a similar group of 22 patients undergoing revision RTCR without suprascapular nerve release. Additionally, UCLA subscores between the two groups were compared preoperatively and at final follow-up. RESULTS: The average preoperative UCLA score in the nerve-release group was 7.91, and final follow-up average was 27.86; average 3.05 grades of strength were recovered. In the comparison group, average preoperative UCLA score was 11.77, and final follow-up average was 29.09; average 1.32 grades of strength were recovered. The average preoperative UCLA score was significantly worse in the nerve-release group (P=0.007). The average postoperative UCLA score was not significantly different (P=0.590) between the groups, indicating a better improvement in the nerve-release group with significantly greater improvement in active forward flexion, strength, and pain relief. CONCLUSION: Patients who underwent concomitant release of the suprascapular nerve during revision RTCR had greater overall improvement as noted in pain relief, active forward flexion, and strength, than a comparable group without nerve release

    Sexual differentiation of the zebra finch song system: potential roles for sex chromosome genes

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    Abstract Background Recent evidence suggests that some sex differences in brain and behavior might result from direct genetic effects, and not solely the result of the organizational effects of steroid hormones. The present study examined the potential role for sex-biased gene expression during development of sexually dimorphic singing behavior and associated song nuclei in juvenile zebra finches. Results A microarray screen revealed more than 2400 putative genes (with a false discovery rate less than 0.05) exhibiting sex differences in the telencephalon of developing zebra finches. Increased expression in males was confirmed in 12 of 20 by qPCR using cDNA from the whole telencephalon; all of these appeared to be located on the Z sex chromosome. Six of the genes also showed increased expression in one or more of the song control nuclei of males at post-hatching day 25. Although the function of half of the genes is presently unknown, we have identified three as: 17-beta-hydroxysteroid dehydrogenase type IV, methylcrotonyl-CoA carboxylase, and sorting nexin 2. Conclusion The data suggest potential influences of these genes in song learning and/or masculinization of song system morphology, both of which are occurring at this developmental stage

    Polarization of the Effects of Autoimmune and Neurodegenerative Risk Alleles in Leukocytes

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    To extend our understanding of the genetic basis of human immune function and dysfunction, we performed an expression quantitative trait locus (eQTL) study of purified CD4[superscript +] T cells and monocytes, representing adaptive and innate immunity, in a multi-ethnic cohort of 461 healthy individuals. Context-specific cis- and trans-eQTLs were identified, and cross-population mapping allowed, in some cases, putative functional assignment of candidate causal regulatory variants for disease-associated loci. We note an over-representation of T cell–specific eQTLs among susceptibility alleles for autoimmune diseases and of monocyte-specific eQTLs among Alzheimer’s and Parkinson’s disease variants. This polarization implicates specific immune cell types in these diseases and points to the need to identify the cell-autonomous effects of disease susceptibility variants

    Complete Genome Sequence of Borrelia miyamotoi Strain MN18-0001, an Am-East-2 Strain Type Isolate Derived From an Ixodes scapularis Tick (Minnesota)

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    We report the genomic sequence of the hard tick relapsing fever spirochete Borrelia miyamotoi strain MN18-0001. B. miyamotoi causes human illness and is geographically widespread in Ixodes spp. (Acari: Ixodidae) ticks. This is a chromosome- and plasmid-resolved genome assembly of an Am-East-2 strain type isolate from the midwestern United States
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