8,167 research outputs found

    The Trichoptera of Panama XIV. New species of microcaddisflies (Trichoptera: Hydroptilidae) from Omar Torrijos Herrera National Park

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    Abstract. In 2017, a new project was begun to assess the biodiversity of national parks and forest reserves in the Republic of Panama. Designated “Proyecto Sistema de Producción Sostenible Conservación de la Biodiversidad (PSPSCB)”, this project is managed by Panama’s Ministerio de Ambiente. The first park sampled in 2017 was Omar Torrijos Herrera National Park (OTHNP). Trichoptera (Insecta) were collected at four locations using both Malaise traps and UV light traps. The rugged terrain and lack of access in this remote park limited the sampled area. Sampling included streams in both the Caribbean and Pacific drainages. Seven new species of microcaddis­flies (Hydroptilidae: Alistotrichia coclensis Armitage and Harris, Cerasmatrichia akanthos Armitage and Harris, Metrichia corazones Armitage and Harris, Neotrichia espinosa Armitage and Harris, Neotrichia michaeli Armit­age and Harris, Neotrichia pierpointorum Armitage and Harris, and Neotrichia yayas Armitage and Harris) and one new country record, Metrichia macrophallata Flint, were identified from this preliminary survey and are re­ported herein. Other recently described species are reported here for the first time outside of their type localities. Based on other areas more extensively sampled compared to this modest survey, many more new species and new country records await discovery in OTHNP as are reported herein. There are now 439 species distributed among 15 families and 55 genera known from Panama. Resumen. En 2017, se inició un nuevo proyecto para evaluar la biodiversidad de parques nacionales y reservas forestales en la República de Panamá. Designado “Proyecto Sistema de Producción Sostenible Conservación de la Biodiversidad (PSPSCB)”, este proyecto es administrado por el Ministerio de Ambiente de Panamá. El primer parque muestreado en 2017 fue el Parque Nacional Omar Torrijos Herrera (OTHNP). Se recogieron Trichoptera en cuatro ubicaciones utilizando trampas Malaise y trampas de luz UV. El terreno accidentado y la falta de acceso en este parque remoto limitaron el área muestreada. El muestreo incluyó corrientes en los drenajes del Caribe y del Pacífico. Siete nuevas especies de micro-Trichoptera (Hydroptilidae: Alistotrichia coclensis Armitage and Harris, Cerasmatrichia akanthos Armitage and Harris, Metrichia corazones Armitage and Harris, Neotrichia es­pinosa Armitage and Harris, Neotrichia michaeli Armitage and Harris, Neotrichia pierpointorum Armitage and Harris, and Neotrichia yayas Armitage and Harris) y un nuevo registro de país, Metrichia macrophallata Flint, se identificaron a partir de esta encuesta preliminar y se informan aquí. Otras especies recientemente descritas se registran aquí por primera vez fuera de sus localidades tipo. Con base en otras áreas más extensamente mues­treadas, en comparación con esta modesta investigación, muchas más especies nuevas y nuevos registros para el país esperan ser descubiertos en el OTHNP como se informa aquí. Ahora en Panamá, hay 439 especies conocidas de Trichoptera distribuidas entre 15 familias y 55 géneros

    How useful are the stages of change for targeting interventions? randomized test of a brief intervention to reduce smoking

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    Objectives. To see whether the stages of change are useful for targeting a brief intervention to reduce smoking based on implementation intentions. A second objective was to rule out demand characteristics as an alternative explanation for the findings of intervention studies based on the transtheoretical model and implementation intentions. Design. Participants (N = 350) were randomized to a passive control condition (questionnaire only), active control condition (questionnaire-plus-instruction to plan to quit) or experimental condition (questionnaire, plan to quit, form an implementation intention). Their behavior and psychosocial orientation to quit were measured at baseline and 2-month follow-up. Main Outcome Measures. Theory of planned behavior variables, nicotine dependence and quitting. Results. Significantly more people quit smoking in the experimental condition than in the control conditions, and the planning instructions changed intention to quit and perceived control over quitting, but not behavior. Stage of change moderated these effects such that implementation intentions worked best for individuals who were in the preparation stage at baseline. Conclusion. Harnessing both motivational and volitional processes seems to enhance the effectiveness of smoking cessation programs, although further work is required to clarify inconsistencies in the literature using the stages of change.</p

    Accretion Disc Evolution in Single and Binary T Tauri Stars

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    We present theoretical models for the evolution of T Tauri stars surrounded by circumstellar discs. The models include the effects of pre-main-sequence stellar and time dependent disc evolution, and incorporate the effects of stellar magnetic fields acting on the inner disc. For single stars, consistency with observations in Taurus-Auriga demands that disc dispersal occurs rapidly, on much less than the viscous timescale of the disc, at roughly the epoch when heating by stellar radiation first dominates over internal viscous dissipation. Applying the models to close binaries, we find that because the initial conditions for discs in binaries are uncertain, studies of extreme mass ratio systems are required to provide a stringent test of theoretical disc evolution models. We also note that no correlation of the infra-red colours of T Tauri stars with their rotation rate is observed, in apparent contradiction to the predictions of simple magnetospheric accretion models.Comment: 11 pages, MNRAS in pres

    Single-Cell Enumeration of an Uncultivated TM7 Subgroup in the

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    Specific oligonucleotide hybridization conditions were established for single-cell enumeration of uncultivated TM7 and IO25 bacteria by using clones expressing heterologous 16S rRNA. In situ analysis of human subgingival crevice specimens revealed that a greater proportion of samples from sites of chronic periodontitis than from healthy sites contained TM7 subgroup IO25. In addition, IO25 bacterial cells from periodontitis site samples were more abundant and fourfold longer than IO25 cells from healthy site samples

    Conservation of the hazel dormouse on the edge of the species’ range

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    Species declines are both widespread and worsening, and climate change is predicted to become one of the biggest drivers. Populations living at the edge of species’ distributional ranges are projected to be particularly vulnerable under future climate change scenarios. Life history strategies, such as dormancy, will play a role in how variation in species resilience and persistence, especially in non-typical habitats at the peripheries of their range, becomes manifest. Energy conservation strategies, such as dormancy, might gain particular significance in the context of a changing climate, potentially affording individuals of some species a competitive advantage. Understanding the energetic and ecological requirements of species, particularly those at the range margins, is likely to become more useful for effective conservation. In this thesis, I have investigated the patterns, drivers, and consequences of daily torpor use in populations of hazel dormice Muscardinus avellanarius in Britain. I have then assessed how this behaviour might change in response to climate change, and what the implications are for dormouse populations. I evaluate new tools for effective conservation of dormice in marginal landscapes by testing species distribution models at different resolutions. I then explore dormouse ecological requirements in these landscapes through dietary analysis. My study reveals that rates of daily torpor are influenced by factors such as the presence of ancient woodland, connectivity of broadleaf habitat, geographic location, and climate. I reveal relationships between torpor, dormouse abundance, and breeding events, directly impacting population dynamics. I then predict the future frequencies of daily torpor in Britain. Projections suggest a reduction in torpor use as local climatic conditions change, potentially leading to increased fecundity among dormouse populations in England and Wales. However, under worst-case climate scenarios, elevated torpor rates are expected in certain years, posing a risk to small populations, especially those at the distributional edge. Conservation strategies should focus on preventing declines at range margins, fostering resilience, and averting range constriction. At a landscape scale, I examined the accuracy of predicting dormouse distribution in non-typical habitats, particularly conifer plantations at the edge of their range in North Wales. Regional and national species distribution models could not accurately predict dormouse presence in non-typical habitat, highlighting the need for increased knowledge of dormouse subsistence in conifer plantation. At a finer-scale, I investigate the persistence of dormouse populations in conifer plantations at the edge of their range. I conducted stable isotope analysis to compare diets between non-typical and optimal habitats. Results indicate varying niche breadths among dormouse populations, with the ability to subsist on a restricted diet in coniferous habitats. The study highlights site-specific food sources, including invertebrates, and underscores the importance of plant diversity and high invertebrate numbers in conservation management. Finally, I collated the findings of this thesis and discuss them within the context of edge of range populations and future threats from climate change. My work aids understanding of hazel dormice energy budgets, habitat requirements, and diets, offering diverse conservation recommendations, particularly in the face of ongoing climate change

    Quasi-Langmuir-Blodgett Thin Film Deposition of Carbon Nanotubes

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    The handling and manipulation of carbon nanotubes continues to be a challenge to those interested in the application potential of these promising materials. To this end, we have developed a method to deposit pure nanotube films over large flat areas on substrates of arbitrary composition. The method bears some resemblance to the Langmuir-Blodgett deposition method used to lay down thin organic layers. We show that this redeposition technique causes no major changes in the films' microstructure and that they retain the electronic properties of as-deposited film laid down on an alumina membrane.Comment: 3 pages, 3 figures, submitted Journal of Applied Physic

    MHD simulations of the collapsar model for GRBs

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    We present results from axisymmetric, time-dependent magnetohydrodynamic (MHD) simulations of the collapsar model for gamma-ray bursts. Our main conclusion is that, within the collapsar model, MHD effects alone are able to launch, accelerate and sustain a strong polar outflow. We also find that the outflow is Poynting flux-dominated, and note that this provides favorable initial conditions for the subsequent production of a baryon-poor fireball.Comment: 4 pages, to appear in proceedings of "2003 GRB Conference" (Santa Fe, NM, September 8-12, 2003), needs aipprocs LaTeX class, movies are available at http://rocinante.colorado.edu/~proga
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