• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 5
  • 5
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 70
  • 24
  • 23
  • 23
  • 8
  • 8
  • 7
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Caracterização molecular de bornavírus, poliomavírus e circovírus em aves de cativeiro, vida livre e criação comercial / Molecular characterization of bornavirus, polyomavirus e circovirus in captive, wild-caught and commercial breeders birds

Natalia Philadelpho Azevedo 14 September 2017 (has links)
As doenças virais são de extrema importância para a saúde das aves. Os vírus podem se espalhar através de fezes, secreções respiratórias ou exfoliação epitelial de penas e pele, dificultando ainda mais esse controle. A utilização do PCR permite detecção de pequenas concentrações do vírus além da possibilidade de diagnosticar a patologia antes de iniciar alterações histológicas. O bornavírus aviário é responsável pela doença da dilatação pró-ventricular (PDD) em psitacídeos e outras aves, uma doença neurológica letal, que foi descoberta no início da década de oitenta na Europa e América do Norte. A detecção do vírus em passeriformes e outras famílias já ocorreu em alguns países. A ocorrência de poliomavírus em outras espécies diferentes dos psitaciformes não é estudada no Brasil, logo não se sabe se há ocorrência da doença nem em aves de cativeiro como em aves de vida livre. O presente trabalho teve como objetivo a padronização das técnicas de PCR e RT-PCR e o estudo epidemiológico dos três tipos virais descritos acima em aves de cativeiro no Brasil. Foram coletadas amostras de passeriformes de vida livre e passeriformes de cativeiro (n=327), galiformes de criação extensiva e comercial (n=90). Nenhuma amostra foi positiva para circovírus e nenhuma amostras de galiformes foi positiva para os vírus testados. A caracterização das amostras biológicas obtidas de psitacídeos resultou na descoberta de um novo genótipo, denominado PaBv-8, atualmente descrito apenas no Brasil. Das amostras de passeriformes testadas, foram encontradas 3 amostras positivas para bornavírus de canário (CnBv-1) e uma para poliomavírus. Esta é a primeira descrição de bornavírus em canário no Brasil. Duas das três amostras positivas para CnBv-1 pertenciam a canários de cativeiro que apresentavam sinais clínicos compatíveis com a doença, enquanto a terceira amostra pertencia a um pula-pula de vida livre, aparentemente assintomático. A ave positiva para poliomavírus apresentou crescimento excessivo do bico, sinal clínico compatível com lesão hepática, que pode ser causada pela infecção viral. A descrição de um novo genótipo assim como a identificação do vírus e da doença em passeriformes indica uma necessidade de reforçar os estudos sobre o assunto no país, assim como rever a legislação a fim de prevenir a disseminação de patógenos. / Viral diseases are of extreme importance for the health of birds. Viruses can spread through feces, respiratory secretions or epithelial exfoliation of feathers and skin, making it even more difficult to control. The use of PCR allows the detection of small concentrations of the vírus, giving the possibility of diagnosing the pathology before initiating histological alterations. The avian bornavirus is responsible for pro-ventricular dilation (PDD) disease in psittacines and other birds, a lethal neurological disease that was discovered in the early 1980s in Europe and North America. Virus detection in passerines and other families has already occurred in some countries. The occurrence of polyomaviruses in species other than psitaciformes was never studied in Brazil. Ut is not known whether the disease occurs in poultry or in free-living birds as well. The present study aimed to standardize the PCR and RT-PCR techniques and the epidemiological study of the three viral types described above in captive birds in Brazil. We collected samples from wild-caught and captive passeriformes (n = 327), galiformes from breeding facilities (n = 90) and captive psitacines (n=10). No samples were positive for circovírus. None of the galiformes samples were positive for any of the virus tested. The characterization of the biological samples obtained from psittacines resulted in the discovery of a new genotype, called PaBv-8, currently described only in Brazil. Passeriformes samples resulted in 3 positive samples for bornavírus, that were further analyzed as canarian bornaviruses 1 (CnBv-1) and one bird was positive for poliomavirus. This is the first description of bornavirus in canary in Brazil. Two out of the three CnBv-1-positive samples belonged to captive canaries showing clinical signs compatible with the disease, whereas the third sample belonged to an apparently asymptomatic free-living pula. The positive bird for polyomavirus presented excessive growth of the beak, clinical sign compatible with hepatic damage, that can be caused by the viral infection. The description of a new genotype as well as the identification of the virus and the disease in passeriformes indicates a need to reinforce the studies on the subject in the country, as well as to review the legislation to prevent the spread of pathogens.
22

GIS based models for optimisation of marine cage aquaculture in Tenerife, Canary Islands

Perez Martinez, Oscar January 2002 (has links)
This study focused on the optimisation of offshore marine fish-cage farming in Tenerife, Canary Islands. The main objective was to select the most suitable sites for offshore cage culture. This is a key factor in any aquaculture operation, affecting both success and sustainability. Moreover, it can solve conflicts between different coastal activities, making a rational use of the coastal space. Site selection was achieved by using Geographical Information Systems (GIS) based models and related technology, such as satellite images and Global Positioning System (GPS), to support the decision-making process. Three different cage systems were selected and proposed for different areas around Tenerife. Finally, a particulate waste distribution model (uneaten feed and faeces) was developed, also using GIS, for future prediction of the dispersive nature of selected sites. This can reduce the number of sites previously identified as most suitable, by predicting possible environmental impacts on the benthos if aquaculture was to be developed on a specific site. The framework for spatial multi-criteria decision analysis used in this study began with a recognition and definition of the decision problem. Subsequently, 31 production functions (factors and constraints) were identified, defined and subdivided into 8 sub-models. These sub-models were then integrated into a GIS database in the form of thematic layers and later scored for standardization. At this stage, the database was verified by field sampling to establish the quality of data used. The decision maker's preferences were incorporated into the decision model by assigning weights of relative importance to the evaluation under consideration. These, together with the thematic layers, were integrated by using Multi-criteria Evaluation (MCE) and simple overlays to provide an overall assessment of possible alternatives. Finally, sensitivity analysis was performed to determine the model robustness. The integration, manipulations and presentation of the results by means of GIS-based models in this sequential and logical flow of steps proved to be very effective for helping the decision-making process of site selection in study. On the whole, this study revealed the usefulness of GIS as an aquaculture planning and management tool. Cage systems that can withstand harsh environments were found to be suitable for use over a broader area of Tenerife's coastline. Thus, the more robust self-tensioned cage (SeaStation®) could be used over a greater area than the weaker gravity cages (Corelsa®). From the 228 km2 of available area for siting cages in the coastal regions with depth of 50 m, the suitable area (sum of scores 6, 7 and 8) for siting SeaStation® cages was 61 km2, while the suitable area for SeaStation® and Corelsa® cages was 49 and 37 km2 respectively. Most of the variation between these three cage systems was found among the intermediate suitability scores. It was concluded that the biggest differences in suitable area among cage systems are between Corelsa® and SeaStation® systems, followed by differences between Corelsa® and OceanSpar® cages, and OceanSpar® and SeaStation® respectively. This variability was mostly located on the N and NNW of the island, where waves, both long and short-term, are higher.
23

Analysis and simulation of systems for delivery of fuel straw to district heating plants /

Nilsson, Daniel. January 1999 (has links)
Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 1999. / Includes bibliographical references.
24

Les prisonniers de guerre au temps du Ier empire. La déportation aux Baléares et aux Canaries (les archipels enchanteurs et farouches) des soldats de Baylen et des marins de Trafalgar (1809-1814)

Geisendorf-Des Gouttes, Théophile. January 1900 (has links)
Thèse--Neuchâtel. / "Sources manuscrites et bibliographie": p. [599]-614.
25

Network dynamics in the neural control of birdsong

Markowitz, Jeffrey Evan 22 January 2016 (has links)
Sequences of stereotyped actions are central to the everyday lives of humans and animals, from the kingfisher's dive to the performance of a piano concerto. Lashley asked how neural circuits managed this feat nearly 6 decades ago, and to this day it remains a fundamental question in neuroscience. Toward answering this question, vocal performance in the songbird was used as a model to study the performance of learned, stereotyped motor sequences. The first component of this work considers the song motor cortical zone HVC in the zebra finch, an area that sends precise timing signals to both the descending motor pathway, responsible for stereotyped vocal performance in the adult, and the basal ganglia, which is responsible for both motor variability and song learning. Despite intense interest in HVC, previous research has exclusively focused on describing the activity of small numbers of neurons recorded serially as the bird sings. To better understand HVC network dynamics, both single units and local field potentials were sampled across multiple electrodes simultaneously in awake behaving zebra finches. The local field potential and spiking data reveal a stereotyped spatio-temporal pattern of inhibition operating on a 30 ms time-scale that coordinates the neural sequences in principal cells underlying song. The second component addresses the resilience of the song circuit through cutting the motor cortical zone HVC in half along one axis. Despite this large-scale perturbation, the finch quickly recovers and sings a near-perfect song within a single day. These first two studies suggest that HVC is functionally organized to robustly generate neural dynamics that enable vocal performance. The final component concerns a statistical study of the complex, flexible songs of the domesticated canary. This study revealed that canary song is characterized by specific long-range correlations up to 7 seconds long-a time-scale more typical of human music than animal vocalizations. Thus, the neural sequences underlying birdsong must be capable of generating more structure and complexity than previously thought.
26

Řadič postupného nasazení software nad platformou Kubernetes / Kubernetes Canary Deployment Controller

Malina, Peter January 2019 (has links)
Potreba dodania hodnoty uživatelom každodočne rastie na kompetitívnom trhu IT. Agilita a DevOps sa stávajú kritickými aspektami pre vývoj software, vyhľadávajúci nástroje ktoré podporujú agilnú kultúru. Softwarové projekty v agilnej kultúre majú častú tendenciu zaoberať sa stratégiami nasadenia ktoré redukujú risk nasadenia nových zmien do existujúceho systému. A však, prostredia určené pre vývoj a testovanie sa takmer vždy odlišujú od produkčných. Využitie primeranej stratégie nasadenie ako canary zlepšuje celkovú stabilitu systému testovaním nových zmien na malej vzorke produkčnej prevádzky. Bolo vykonaných niekoľko experimentov pre dôkaz, že stratégia canary môže pozitívne ovplyvniť stabilitu nasadení a redukovať risk ktorý prinášajú nové zmeny.
27

CEMENT COMPOSITION EFFECTS ON ENAMEL DEMINERALIZATION ADJACENT TO ORTHODONTIC BRACKETS: AN IN VITRO STUDY USING THE CANARY SYSTEM

Dorfman, Jake January 2017 (has links)
Incipient caries lesions or white spot lesions are one of the most common clinical problems resulting from orthodontic treatment with fixed appliances. Literature has shown that infrared photothermal radiometry and modulated luminescence (PTR-LUM), used by The Canary System for caries detection, is capable of monitoring artificially created carious lesions and their evolution during demineralization. Recently, a water-based calcium aluminate glass ionomer luting cement, Ceramir, has shown bioactive surface apatite formation that may influence local remineralization. This in vitro study’s objective was to evaluate effects of bioactive cement on enamel demineralization around orthodontic brackets compared to composite resin cement. A sample of 32 caries-free extracted human teeth was collected under an IRB-exempt protocol. Orthodontic brackets were cemented to each tooth with either Transbond XT or Ceramir. A 3x3 mm window adjacent to the bracket was created with acid-resistant varnish f / Oral Biology
28

The early lives of the Islanders: Stable isotope analysis of incremental dentine collagen from the prehispanic period of the Canary Islands

Elías Sánchez-Cañadillas, Julia Beaumont, Jonathan Santana-Cabrera, Marise Gorton, Matilde Arna,, Sánchez-Cañadillas, E., Beaumont, Julia, Santana-Cabrera, J., Gorton, M., Arna, M. 19 July 2023 (has links)
Yes / Objectives: This study presents isotopic information for incremental dentine collagen and bone bulk collagen from individuals from the Canary Islands (Tenerife and Gran Canaria) to explore dietary differences during childhood life. Materials and Methods: Eight individuals have been studied, which comprises 122 δ15N and δ13C incremental dentine measurements and eight bulk bone collagen analyses. A baseline of potentially consumed food sources has been developed for comparative purposes. A FRUITS model of probable contributions of each food source towards the diet of each individual has been developed. All samples but one belongs to the later period of indigenous occupation of the archipelago. Results: The dentine collagen data are presented in correlated δ13C and δ15N plots per individual, showing the isotopic changes throughout time. δ15N values for each individual tend to be variable whereas δ13C data are generally more stable with a range of +9.1 to +14‰ for δ15N and –17.4 to –20.8‰ for δ13C. Conclusion: The isotopic analysis allows for the reconstruction of 8 dietary profiles, which allow us to estimate the different dietary protein sources. The FRUITS model shows different percentages of the primary food sources for each individual. Where both δ13C and δ15N are elevated, this could be indicative of a higher marine contribution to the diet. There appear to be two main dietary profiles identifiable in the dataset and these may be related to changes in status or place of residence. Short-term variations in δ13C and δ15N and opposing co-variance of isotopic values can be indicative of nutritional stress, although metabolic changes during growth are also considered. / PhD grant from Universidad de La Laguna—Fundación La Caixa (“Contratos Predoctorales para la formación de doctores ULL-2015”), MINECO (Ministerio de Economía y Competitividad) project “Guanches y europeos en Las Cañadas del Teide, Ocupación, Producción y Comunicación” (HAR2015-68323-P), “Erasmus+ Scholarship” given by the University of La Laguna, ERC Starting Grant project IsoCAN (grant 851733, European Comission) and the projects RTI2018-101923-J-I00 and RYC2019-028346 (Ministerio de Ciencia e Innovación)
29

Negotiating Heritage: Heritage Organizations amongst the Isleños of St. Bernard Parish, Louisiana and the Use of Heritage Identity to Overcome the Isleño/Tornero Distinction

West, Jonathan Joseph 15 May 2009 (has links)
The Isleños of St. Bernard Parish, Louisiana trace their ancestry to eighteenth century settlers from the Canary Islands. Currently, St. Bernard Parish is home to two separate Canarian heritage organizations: Los Isleños Heritage and Cultural Society and the Canary Islands Descendents Association. This thesis examines how the Isleños are currently renegotiating their cultural identity through the use of heritage via the structure of heritage organizations. I argue that under mounting economic, environmental, and political pressure, people of Canarian descent in St. Bernard Parish have begun to adjust Isleño cultural identity in order to make it more widely inclusive. This is a creative means by which the Isleños attempt to maneuver around the increasingly rapid pace of change and deal with threats to the survival of their culture.
30

Genetic Diversity of the Endemic Canary Island Pine Tree, Pinus canariensis

Navascués, Miguel 06 February 2005 (has links) (PDF)
The Canary Island pine, Pinus canariensis, is an endemic tree that forms one of the main forest ecosystems within the archipelago, and whose distribution has been reduced in the last five centuries by clear cutting for the extraction of timber and tar. It was in the XXth century that exploitation declined and reforestation programs were brought forward for the restoration of an ecosystem that harbours a number of endangered endemic species of plants and animals. In addition to reforestation efforts, an understanding of population genetic processes is also necessary for the successful conservation management of the Canarian pine forest, particularly in light of gathering evidence for local adaptation.<br /><br />In this thesis historical and contemporary gene flow within P. canariensis was studied with nuclear and chloroplast microsatellite markers. High immigration rates (0.68–0.75) were estimated as expected for an outcrossing windpollinated tree. Nevertheless, significant population differentiation (theta = 0.019, RST = 0.044) was detectable for sites separated by only a few kilometres. Within the context of reforestation programs the high levels of gene flow detected would appear to have a positive effect on reforested stands by facilitating the immigration of local alleles from natural stands into potentially genetically depauperate first generation gene pools of reforested stands.<br /><br />Historical population growth was revealed with chloroplast microsatellites for most populations of P. canariensis. Population expansions for the pine parasite weevil Brachyderes rugatus were also detected, broadly coinciding with the population expansions within the Canary Island pine forests. Given the estimated times of expansion, these population demographic increases would seem likely related to the process of colonisation of newly emerged islands or local patches after volcanic disturbance. Detection and dating of these expansions from chloroplast microsatellites was, to some degree, negatively affected by homoplasy (i.e. parallel and back mutations).<br /><br />Coalescent simulations of the evolution of chloroplast microsatellites were applied to study the effects of homoplasy in the statistical analysis of population structuring. Measures of genetic diversity based on number of haplotypes and genetic distances were differently affected. Genetic distances were underestimated but were proportional to the actual value. These effects help to explain the lower performance of statistical analyses for the detection and dating of population expansions. Further research on the effects of homoplasy in the analysis of population differentiation using chloroplast microsatellites is essential.

Page generated in 0.0549 seconds