Global ETD Search

1	Saproxylic Beetles (Coleoptera) Associated With Aspen Deadwood in Broad-Leaved Boreal Mixedwood Stands Wood, Charlene M Unknown Date No description available. saproxylic coleoptera deadwood beetles aspen Populus snag biodiversity forest collection method decay
2	Ecological and Behavioral Impacts of Snag Density on Cavity-Nesting Birds in the Oak Savanna Johnston, Christine Ninette 04 June 2007 (has links) No description available. Biology, Ecology snag cavity-nesting bird oak savanna behavioral ecology disturbance
3	Golfový výukový program zaměřený na děti a mládež se sluchovou disabilitou v rámci volnočasových aktivit / Golf training program focused on children and youth with hearing disability in the context of leisure activities ČERMÁKOVÁ, Lucie January 2016 (has links) Thesis "Golf training program focused on children and youth with hearing disability in the context of leisure activities " in its theoretical part deals with the theme of hearing disability in terms of etiology, diagnosis and classification, focuses also on communication systems. More attention is devoted to the development, education and specifics of physical activities in children with hearing disability. Finally introduces golf training program called SNAG which is still new in the world and its versatility is ideal for teaching in schools. The research deals with the influence of the interventional motion program focused on golf lessons for children and youth with hearing disability aged 7 to 18 years. The aim of this thesis is to evaluate positive impact of golf training program on physical and psychosocial health within a standardized questionnaire PedsQLTM 4.0. Based on the results which are presented in graphs and tables each with a brief commentary confirms the positive impact of golf training program on physical and psychosocial health of all individuals in the experimental group. After completion of the three-month intervention program there was an overall average improvement of 6 % on physical health and 5.1 % on psychosocial health. The results of the control group were with no significant differences. The main contribution of this thesis is to verificate the positive impact of golf training program on physical and psychosocial health in children and youth with hearing disability in age from 7 to 18 years.
4	Experimental study of an avian cavity-nesting community: nest webs, nesting ecology, and interspecific interactions Blanc, Lori A. 04 September 2007 (has links) Cavity-nesting communities are structured by the creation of and competition for cavities as nest-sites. Viewing these communities as interconnected webs can help identify species interactions that influence community structure. This study examines cavity-nesting bird community interactions within the fire-maintained longleaf pine (Pinus palustris) ecosystem at Eglin Air Force Base, Florida. In chapter 1, I provide a background review of the ecology of my study system. In chapter 2, I use nest webs to depict the flow of cavity-creation and use at Eglin. I identified 2 webs into which most species could be placed. One web contained 6 species associated with pines. The second web contained 5 species associated with hardwoods. Red-cockaded woodpeckers (Picoides borealis) and northern flickers (Colaptes auratus) created most cavities used by other species within this community. In chapter 3, I describe snag densities and nest-site selection of the cavity-nesting bird community at Eglin. Large, mature pine snags were abundant, exceeding other reported densities for southern pine forests. Pine snags were heavily-used, despite the abundance of available red-cockaded woodpecker cavities in living pine. Hardwood snags accounted for 10% of nests found, and were used by 12 of 14 species. Diameters of nest-trees and available snags were below the range of optimal nest-snag diameters reported in other studies, indicating the need for site-specific snag management guidelines. In chapter 4, I combine a study of basic ecological principles with endangered species management to examine interactions within the cavity-nesting bird community at Eglin. I used a nest web to identify a potential indirect interaction between the red-cockaded woodpecker and large secondary cavity-nesters, mediated by the northern flicker. I used structural equation modeling to test a path model of this interaction. By experimentally manipulating cavity availability, I blocked links described in the model, confirming cavity creation and enlargement as mechanisms that influence this indirect relationship. I demonstrated that a red-cockaded woodpecker cavity-management technique could disrupt this indirect relationship by affecting northern flicker behavior, and provided an empirical example of how, in interactive ecological communities, single-species management can have indirect effects on non-target species. / Ph. D. cavity-nester ecosystem engineer snag structural equation modeling red-cockaded woodpecker Colaptes auratus nest web Picoides borealis longleaf pine northern flicker endangered species management indirect interaction keystone species
5	Examination of airborne discrete-return lidar in prediction and identification of unique forest attributes Wing, Brian M. 08 June 2012 (has links) Airborne discrete-return lidar is an active remote sensing technology capable of obtaining accurate, fine-resolution three-dimensional measurements over large areas. Discrete-return lidar data produce three-dimensional object characterizations in the form of point clouds defined by precise x, y and z coordinates. The data also provide intensity values for each point that help quantify the reflectance and surface properties of intersected objects. These data features have proven to be useful for the characterization of many important forest attributes, such as standing tree biomass, height, density, and canopy cover, with new applications for the data currently accelerating. This dissertation explores three new applications for airborne discrete-return lidar data. The first application uses lidar-derived metrics to predict understory vegetation cover, which has been a difficult metric to predict using traditional explanatory variables. A new airborne lidar-derived metric, understory lidar cover density, created by filtering understory lidar points using intensity values, increased the coefficient of variation (R²) from non-lidar understory vegetation cover estimation models from 0.2-0.45 to 0.7-0.8. The method presented in this chapter provides the ability to accurately quantify understory vegetation cover (± 22%) at fine spatial resolutions over entire landscapes within the interior ponderosa pine forest type. In the second application, a new method for quantifying and locating snags using airborne discrete-return lidar is presented. The importance of snags in forest ecosystems and the inherent difficulties associated with their quantification has been well documented. A new semi-automated method using both 2D and 3D local-area lidar point filters focused on individual point spatial location and intensity information is used to identify points associated with snags and eliminate points associated with live trees. The end result is a stem map of individual snags across the landscape with height estimates for each snag. The overall detection rate for snags DBH ≥ 38 cm was 70.6% (standard error: ± 2.7%), with low commission error rates. This information can be used to: analyze the spatial distribution of snags over entire landscapes, provide a better understanding of wildlife snag use dynamics, create accurate snag density estimates, and assess achievement and usefulness of snag stocking standard requirements. In the third application, live above-ground biomass prediction models are created using three separate sets of lidar-derived metrics. Models are then compared using both model selection statistics and cross-validation. The three sets of lidar-derived metrics used in the study were: 1) a 'traditional' set created using the entire plot point cloud, 2) a 'live-tree' set created using a plot point cloud where points associated with dead trees were removed, and 3) a 'vegetation-intensity' set created using a plot point cloud containing points meeting predetermined intensity value criteria. The models using live-tree lidar-derived metrics produced the best results, reducing prediction variability by 4.3% over the traditional set in plots containing filtered dead tree points. The methods developed and presented for all three applications displayed promise in prediction or identification of unique forest attributes, improving our ability to quantify and characterize understory vegetation cover, snags, and live above ground biomass. This information can be used to provide useful information for forest management decisions and improve our understanding of forest ecosystem dynamics. Intensity information was useful for filtering point clouds and identifying lidar points associated with unique forest attributes (e.g., understory components, live and dead trees). These intensity filtering methods provide an enhanced framework for analyzing airborne lidar data in forest ecosystem applications. / Graduation date: 2013 Airborne lidar Understory vegetation Snag detection & quantification Standing tree biomass Intensity Beta regression Weighted regression Log-linear regression Optical radar Forest biomass -- Remote sensing Understory plants -- Remote sensing Snags (Forestry) -- Remote sensing
6	Microstructural Investigations of Low Temperature Joining of Q&P Steels Using Ag Nanoparticles in Combination with Sn and SnAg as Activating Material Hausner, Susann, Wagner, Martin Franz-Xaver, Wagner, Guntram 14 February 2019 (has links) Quenching and partitioning (Q&P) steels show a good balance between strength and ductility due to a special heat treatment that allows to adjust a microstructure of martensite with a fraction of stabilized retained austenite. The final heat treatment step is performed at low temperatures. Therefore, joining of Q&P steels is a big challenge. On the one hand, a low joining temperature is necessary in order not to influence the adjusted microstructure; on the other hand, high joint strengths are required. In this study, joining of Q&P steels with Ag nanoparticles is investigated. Due to the nano-effect, high-strength and temperature-resistant joints can be produced at low temperatures with nanoparticles, which meets the contradictory requirements for joining of Q&P steels. In addition to the Ag nanoparticles, activating materials (SnAg and Sn) are used at the interface to achieve an improved bonding to the steel substrate. The results show that the activating materials play an important role in the successful formation of joints. Only with the activating materials, can joints be produced. Due to the low joining temperature (max. 237 °C), the microstructure of the Q&P steel is hardly influenced. info:eu-repo/classification/ddc/620 ddc:620
7	Cavity Presence in Snags Created Using Two Techniques in the Huron-Manistee National Forest Nadler, Madison January 2020 (has links) No description available. Biology Forestry Wood Wildlife Management Ecology Environmental Science Wood Sciences Natural Resource Management standing dead trees snags tree topping prescribed burning controlled burning tree cavities forest management forest ecology animal habitats Huron-Manistee National Forest Michigan red pine plantations snag decay
8	Mecanismes de regulació en l'activitat biològica del factor de transcripció Snail Domínguez Solà, David 03 April 2003 (has links) Els factors de transcripció de la família Snail són fonamentals en la "transició epiteli-mesènquima", procés morfogènic essencial en el desenvolupament embrionari i en els fenòmens metastàsics tumorals.En els mamífers l'activitat d'Snail és modulada per dos mecanismes. (i) En el promotor humà es troben regions definides de resposta a factors repressors, predominants en les cèl·lules epitelials, i elements diferenciats de resposta a inductors de la "transició epiteli-mesènquima". (ii) L'activitat d'Snail és condicionada també per la seva localització subcel·lular, modulada per mecanismes no transcripcionals: la fosforilació d'Snail determina si és o no exclós del nucli. Al citosol no pot actuar com a repressor transcripcional però pot interaccionar amb la xarxa microtubular, que estabilitza i en condiciona el dinamisme. Això coincideix amb l'activació de la GTPasa RhoA i la reorientació dels filaments de vimentina, fets associats a l'adquisició de capacitat migratòria. L'efecte com a repressor transcripcional i la modulació del dinamisme microtubular són possiblement esdeveniments coordinats necessaris per al rol biològic d'Snail en mamífers. / Snail family of transcription factors is fundamental to the "epithelial-mesenchymal transition", morphogenic process essential to embryonic development and metastatic phenomena in tumors.Snail's activity is modulated in two ways in mammals. (i) The human promoter harbors definite regions that respond to repressor factors, which prevail in epithelial cells; and differentiated elements that respond to known inducers of the "epithelial-mesenchymal transition". (ii) Snail's activity is also conditioned by its subcellular localization, mechanism not dependent on its transcriptional control: Snail phosphorylation determines whether Snail is excluded or not from the nucleus. When in the cytosol, Snail is unable to act as a transcriptional repressor, but however binds to the microtubular meshwork, which becomes stabilized and whose dynamism is conditioned as a result. This fact coincides with the activation of the RhoA GTPase and reorientation of vimentin filaments, both phenomena being related to the acquisition of cell motility. The transcriptional repressor and the microtubule dynamics effects are probably two coordinated events necessary to Snail's biological role in mammals. Polimerització in vitro PKCzeta PKC atípica (Protein Kinase C) P65 Promotor Nocodazol NF-kB/Dorsal (Nuclear Factor Kappa-B) NES (seqüència d'export nuclear) Microtúbuls detirosinats Microtúbuls Metàstasi Invasió Adenocarcinoma ARNm Beta-catenina Centrosoma CLIP-170 Cancer Cresta neural CRM1 (Chromosome Region Maintenance 1) Despolimerització microtúbuls Dit de Zenc atípic Dit de Zenc Domini ric en Serines Ebox E-cadherina Espais intercromatínics Estabilització microtúbuls Export nuclear Filaments intermediaris Fosforilació Gastrulació GFP (Green Fluorescent Protein) Heterocarions ILK (Integrin Linked Kinase) Promotor Reconstrucció fronts invasius Regulació Retrogen RhoA GTPasa SC35 Slug SNAG (domini) SNAI1L Snail Speckles nuclears Time-lapse Èster de forbol Transició Epiteli-Mesènquima Transcripció / Transcripcional U2AF65 Vimentina 57

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