2,760 research outputs found

    Demonstration of Sex Pheromones in \u3ci\u3eMolanna Uniophila\u3c/i\u3e (Trichoptera: Molannidae), \u3ci\u3ePlatycentropus Radiatus, Pycnopsyche Indiana, and P. Subfasciata\u3c/i\u3e (Trichoptera: Limnephilidae), With an Assessment of Interspecific Attraction Between Four Sympatric \u3ci\u3ePycnopsyche\u3c/i\u3e Species

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    Evidence for sex pheromones in the caddisflies Molanna uniophila Vorhies, Platycentropus radiatus (Say), Pycnopsyche indiana (Ross), and P. subfasciata (Say) is presented here for the first time based on field studies conducted in southern Michigan. For all species, numbers of males caught in pheromone traps baited with conspecific female extracts were higher than those caught in traps with male extracts, or those without extract. Four sympatric species of Pycnopsyche: P. guttifer (Walker), P. indiana, P. lepida (Hagen), and P. subfasciata exhibited no interspecific pheromonal attraction despite a common mating season and, in the case of P. indiana and P. lepida, very similar genitalic morphology. Our results suggest the importance of pheromones in maintaining reproductive isolation between closely related species. Likewise, pheromone biology can help delineate morphologically cryptic species

    A Model for Federal Public Land Surface Rights' Management

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    The U.S. Forest Service and U.S. Bureau of Land Management control larges tracts of Federal public lands mainly in the western United States. Management goals for lands controlled by these agencies are described as "multiple-use." Some of the lands are forested, mountainous, contain wildlife or possess other scenic and recreational attributes and warrant the federal multiple-use designation; however, a significant portion of the land, especially that under BLM control, contains little scenic, recreation or wildlife value, thus offering very little multiple-use potential and non-pecuniary value. Much of the land not warranting multiple-use potential has never been titled to anyone except the Federal Government (never sold nor homesteaded). Inherent in the management of all Federal lands is a defacto fiduciary responsibility to prudently and efficiently manage these assets. We develop a framework that measures present values of both quantitative and qualitative economic benefits and costs of Federal public lands to assist managers and policy makers in determining future management policy. By applying this framework, Federal public land policymakers may be aided in fulfilling their fiduciary responsibilities.

    Valuation of Property Surrounding a Resort Community

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    This article uses hedonic modeling for valuation of real estate located near Jackson, Wyoming and agricultural property throughout the remainder of Wyoming. The attributes of the hedonic model used to value resort properties are compared with attributes of the model used to value agricultural properties. It is observed that attributes affecting the value of resort property are significantly different from attributes affecting the value of agricultural property. Resort properties, even though classified as agricultural, derive their values from scenic amenities, existence of streams, vegetation and relative location. Alternatively, agricultural lands throughout the remainder of Wyoming derive value from a combination of productive and nonproductive attributes.

    Additional Evidence on the Homogeneity of the Value of Government Grazing Leases and Changing Attributes for Ranch Values

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    Using Wyoming ranch sales from 1979-1983 and 1989-1993, this study investigates how ranch value determining attributes may have changed over this period. The 1979-1983 period is one of political stability and rising prices. In constrast, the 1989-1993 period is one of political uncertainty but stable prices. It is found, during 1989-1993, ranch prices were based more on productivity; whereas, during the earlier period, prices were based more on speculative potential. Also, it is found that government grazing leases were valued differently between time periods, ecological regions, and types of leases. This suggests that the current single-price grazing fee commonly used misprices many leases. Because of the heterogeneity in the value of grazing leases, we recommend a variable-fee form of pricing be adopted.

    The pioneer projects: Economical exploration of the solar system

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    The interplanetary Pioneer missions are reviewed in terms of management implications and cost control. The responsibilities, organizational structure, and management practices of the Pioneer Projects are presented. The lines of authority and areas of responsibility of the principal organizational elements supporting the Pioneer missions are identified, and the methods employed for maintaining effective and timely interactions among these elements are indicated. The technical and administrative functions of the various organizational elements of the Pioneer Project Office at Ames Research Center are described in terms of their management responsibilities and interactions with other elements of the Project Office and with external organizations having Pioneer Project responsibilities. The management and control of activities prior to and during the hardware procurement phase are described to indicate the basis for obtaining visibility of the technical progress, utilization of resources, and cost performance of the contractors and other institutions supporting the Pioneer projects

    An Operational Performance and Safety Comparison of Roundabouts vs. Traditional Intersections

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    As the modern roundabout becomes a more popular intersection alternative in the United States, the ability of the roundabout to effectively manage traffic and to do so safely is on the forefront of engineering concerns. Despite decades of international success and credibility, regions throughout the U.S. have been hesitant to implement roundabouts in place of more traditional intersections. This case study of a series of intersections in Dublin, OH assesses the operational performance of roundabouts as it compares to that of their stop-controlled and signalized counterparts and analyzes historical crash data to evaluate the safety of the various intersection types. Operationally, roundabouts proved to operate better than their alternatives up to a certain capacity. While the roundabouts did not show significantly fewer crashes than other intersections, injury rates for crashes were lower at roundabouts. With further data regarding traffic volumes, this research can help U.S. engineers understand the operational and safety benefits of modern roundabouts

    Investigations on the occurrence of infections with hepatitis E virus and related viruses in zoo animals

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    Introduction Hepatitis E is a worldwide distributed disease, which is caused by the hepatitis E virus (HEV). In addition to humans, domestic pigs, wild boars, rabbits and dromedaries can be subclinically infected as reservoir animals with the zoonotic HEV genotypes 3, 4 and 7. In addition, HEV and HEV-like viruses have been described sporadically in other mammals, as well as in birds and fish, although their distinct role as reservoirs or carriers of the virus is still unclear. Aims The aim of the study was therefore to analyse in more detail the importance of different mammalian species, which do not belong to the known HEV reservoirs, for the epidemiology of HEV infections, thus enabling a better assessment of the risk of virus transmission by these animal species. Material and Methods Fourteen non-human primate species and 66 other mammal species, as well as Norway rats (Rattus norvegicus) and feeder rats (Rattus norvegicus forma domestica) from German zoos were selected for the investigations. In total 259 individual non-human primate sera and 244 individual mammalian sera of clinically healthy zoo animals were analysed for the presence of HEV-specific antibodies (ab) using a species-independent double-antigen sandwich ELISA. The non-human primate sera were additionally examined using a commercial human ELISA. Real-time reverse-transcription (RT)-PCR, nested broad-spectrum RT-PCR and a rat HEV-specific RT-PCR were used to detect the HEV genome in sera of mammals and rat liver samples. A commercial and an in-house method were used for the DNA sequencing. Results HEV-specific ab were detected in 3.9% (10/259) of the non-human primate sera (4 species) and 11.5% (28/244) of the mammalian sera (16 species). The highest detection rates were recorded with 33.3% (9/27) in porcines and with 27.0% (10/37) in carnivores. HEV-RNA was detected in a clinically healthy female Syrian brown bear (Ursus arctos syriacus) and in 8 of the investigated Norway rats. Sequence analysis identified the virus as rat HEV; the viruses from the bear and the free-ranging rats from the same zoo showed a high nucleotide sequence identity (94.6%–97.8%). Because of the small number of samples due to the small populations within the individual zoos, further statistical evaluations were not carried out. Conclusions The results show that non-human primates in zoos may be infected with HEV or HEV-like viruses; however, the low ab detection rates together with the negative genome detection argue against a high risk of virus transmission to humans. The study in other zoo-housed mammalian species was able to significantly increase the number of animal species with indications of HEV infections. In most animal species, only rare evidence and low detection rates were available, which can best be explained by “spillover-infections”. In addition to the expected high detection rate in porcine species, the high percentage of HEV antibody-positive carnivores is remarkable. Their role as possible HEV reservoir animals should therefore be clarified in further investigations. The detection of rat HEV in the serum of the bear and its high nucleotide sequence identity with the HEVs of the pest rodents provides first evidence of transmission of this virus species between rodents and carnivores.:List of content List of figures List of tables List of abbreviations 1 General introduction 1.1 Discovery of HEV 1.2 Taxonomy 1.3 Morphology 1.4 Genomic organisation 1.5 Viral replication 1.6 Hepatitis E in humans 1.7 Tools for HEV diagnosis 1.8 Therapy 1.9 Animal infections with HEV and HEV-like viruses 1.10 Experimental infections of animals 1.11 Geographical distribution 1.12 Transmission pathways 1.13 Epidemiology 1.14 Prevention 2 Aims of the study 3 Publications 3.1 Publication I 3.1.1 Summary of Publication I 3.1.2 Key messages of Publication I 3.1.3 Own contribution to Publication I 3.2 Publication II 3.2.1 Summary of Publication II 3.2.2 Key messages of Publication II 3.2.3 Own contribution to Publication II 3.3 Publication III 3.3.1 Summary of Publication III 3.3.2 Key messages of Publication III 3.3.3 Own contribution to Publication III 4 General discussion 4.1 HEV infections in various animal species 4.2 Prevalence of natural HEV infections in non-human primates 4.3 Prevalence of natural HEV infections in other zoo-housed mammals 4.4 Transmission pathways of HEV in a zoo-setting 4.5 Risk of virus transmission from zoo animals to humans 5 Conclusion and perspectives 6 Summary 7 Zusammenfassung 8 References List of animals investigated in the study List of publications AcknowledgementsEinleitung Hepatitis E ist eine durch das Hepatitis E-Virus (HEV) verursachte, weltweit verbreitete Erkrankung. Neben dem Menschen können Hausschwein, Wildschwein, Kaninchen und Dromedar als Reservoirtiere subklinisch mit den zoonotischen HEV-Genotypen 3, 4 und 7 infiziert werden. DarĂŒber hinaus wurden HEV und HEV-Ă€hnliche Viren vereinzelt bei weiteren SĂ€ugetieren, sowie Vögeln und Fischen beschrieben, wobei deren genaue Rolle als Reservoir oder ÜbertrĂ€ger des Virus bislang unklar ist. Ziele Ziel der Arbeit war es deshalb, die Bedeutung verschiedener SĂ€ugetierarten, die nicht zu den bekannten HEV-Reservoiren gehören, fĂŒr die Epidemiologie der HEV-Infektionen besser zu erfassen und dadurch das Risiko einer VirusĂŒbertragung durch diese Tierarten besser abzuschĂ€tzen. Material und Methoden Vierzehn Affenarten und 66 weitere SĂ€ugetierarten, sowie Wanderratten (Rattus norvegicus) und Futterratten (Rattus norvegicus forma domestica) aus deutschen Zoos wurden fĂŒr die Untersuchungen ausgewĂ€hlt. Insgesamt wurden 259 individuelle Affenseren und 244 individuelle SĂ€ugerseren klinisch gesunder Zootiere mittels eines Spezies-unabhĂ€ngigen Doppel-Antigen-Sandwich-ELISAs auf das Vorhandensein von HEV-spezifischen Antikörpern (AK) untersucht. Die Affenseren wurden zusĂ€tzlich mittels eines kommerziellen humanen ELISAs untersucht. Real-time reverse-transcription (RT)-PCR, nested broad-spectrum RT-PCR sowie eine Ratten-HEV-spezifische RT-PCR wurden fĂŒr den HEV-Genomnachweis in Seren der SĂ€uger und in Ratten-Lebern verwendet. FĂŒr die DNA-Sequenzierungen wurden eine kommerzielle und eine In-house-Methode verwendet. Ergebnisse In 3,9% (10/259) der Affenseren (4 Arten) und 11,5% (28/244) der SĂ€ugerseren (16 Arten) wurden HEV-spezifische AK nachgewiesen. Die höchsten Nachweisraten wurden mit 33,3% (9/27) in Schweineartigen und 27,0% (10/37) in Fleischfressern ermittelt. HEV-RNA wurde in einer klinisch gesunden Syrischen BraunbĂ€rin (Ursus arctos syriacus), sowie in 8 der untersuchten Wanderratten nachgewiesen. Die Sequenzanalyse identifizierte das Virus als Ratten-HEV; die Viren aus der BĂ€rin und aus den wildlebenden Ratten desselben Zoos zeigten eine hohe Nukleotidsequenz-IdentitĂ€t (94,6%–97,8%). Weitergehende statistische Auswertungen wurden wegen der geringen Probenzahlen aufgrund der kleinen Populationen innerhalb der einzelnen Zoos nicht durchgefĂŒhrt. Schlussfolgerungen Die Ergebnisse zeigen, dass Affen in Zoos mit HEV oder HEV-Ă€hnlichen Viren infiziert sein können, jedoch sprechen die geringen AK-Nachweisraten zusammen mit den negativen Genomnachweisen gegen ein hohes Übertragungsrisiko auf den Menschen. Die Studie an anderen SĂ€ugetierarten in Zoos konnte die Zahl der Tierarten mit Hinweisen auf HEV-Infektionen deutlich erhöhen. Bei den meisten Tierarten lagen nur seltene Nachweise und niedrige Detektionsraten vor, die am besten durch „Spillover-Infektionen“ erklĂ€rt werden können. Neben der erwarteten hohen Nachweisrate bei Schweineartigen ist der hohe Prozentsatz an HEV AK-positiven Fleischfressern bemerkenswert, weshalb deren Rolle als mögliche HEV-Reservoirtiere in weiteren Untersuchungen geklĂ€rt werden sollte. Der Ratten-HEV-Nachweis im Serum der BĂ€rin, sowie dessen hohe Nukleotidsequenz-IdentitĂ€t zu den HEVs der Schadnager geben erstmals Hinweise auf eine Übertragung dieser Virusart zwischen Nagern und Fleischfressern.:List of content List of figures List of tables List of abbreviations 1 General introduction 1.1 Discovery of HEV 1.2 Taxonomy 1.3 Morphology 1.4 Genomic organisation 1.5 Viral replication 1.6 Hepatitis E in humans 1.7 Tools for HEV diagnosis 1.8 Therapy 1.9 Animal infections with HEV and HEV-like viruses 1.10 Experimental infections of animals 1.11 Geographical distribution 1.12 Transmission pathways 1.13 Epidemiology 1.14 Prevention 2 Aims of the study 3 Publications 3.1 Publication I 3.1.1 Summary of Publication I 3.1.2 Key messages of Publication I 3.1.3 Own contribution to Publication I 3.2 Publication II 3.2.1 Summary of Publication II 3.2.2 Key messages of Publication II 3.2.3 Own contribution to Publication II 3.3 Publication III 3.3.1 Summary of Publication III 3.3.2 Key messages of Publication III 3.3.3 Own contribution to Publication III 4 General discussion 4.1 HEV infections in various animal species 4.2 Prevalence of natural HEV infections in non-human primates 4.3 Prevalence of natural HEV infections in other zoo-housed mammals 4.4 Transmission pathways of HEV in a zoo-setting 4.5 Risk of virus transmission from zoo animals to humans 5 Conclusion and perspectives 6 Summary 7 Zusammenfassung 8 References List of animals investigated in the study List of publications Acknowledgement

    Happy cake meltdown

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    This group of work addresses the complexities that come as a result of stimulation overload. The breakdown of singular focus triggers the demand that everything in your reality be considered simultaneously. The result is a Happy Cake Meltdown, a visual and auditory coping mechanism with no beginning, no middle and no end. It’s about fragmentation and choosing flexibility over specialization. It’s about everything
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