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Gierl, Christoph [Verfasser], and Bettina [Akademischer Betreuer] Reichenbacher. "A fresh look on fossil gobioids and gobioid phylogeny / Christoph Gierl ; Betreuer: Bettina Reichenbacher." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1199265845/34.
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Castro, Mario. "Activité prédatrice du Goujon Gobio gobio, Cyprinidae aspects écoéthologiques." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37596529m.
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Castro, Mario. "Activité prédatrice du goujon Gobio gobio (Cyprinidae) : aspects écoéthologiques." Lyon 1, 1986. http://www.theses.fr/1986LYO11718.
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Origine alimentaire des differences de tailles et de croissance individuelles entre les populations de goujons de l'est de la saone et celle du massif central. Le regime alimentaire des goujons a ete etudie en tenant compte non seulement des effectifs des proies consommees mais aussi de leur valeur alimentaire. Les differences du regime reposent aussi sur des caracteristiques du comportement predateur.
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Aboaba-Onadeko, Christie Abiodun. "Biology and biochemical systematics of the West African gobioid fishes with reference to the sleeper gobies (Teleostei: eleotridae) of the Lagos Lagoon, Nigeria." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271835.
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Gut, Carolin [Verfasser], and Bettina [Akademischer Betreuer] Reichenbacher. "Gobioids now and then : Statistical investigation of hard part characters of fossil and extant gobies / Carolin Gut ; Betreuer: Bettina Reichenbacher." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/122878745X/34.
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Taylor, Mark. "Immunoparasitological studies on Ligula intestinalis (Cestoda: Pseudophyllidea) in roach (Rutilus rutilus) and gudgeon (Gobio gobio)." Thesis, Keele University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304479.
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Harrison, I. J. "The implications of small size in Teleost fish, with special reference to the Gobioidei." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381364.
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McKay, Stuart Ian. "Isozyme genetics and the phylogeny of gobioid fishes." Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317878.
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Petitjean, Quentin. "Variabilité de réponse aux stress multiples chez le goujon (Gobio occitaniae)." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30310.
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Dans le milieu naturel, les poissons sont exposés à une multitude de facteurs de stress biotiques et abiotiques, mais leurs interactions sont encore mal connues. La hausse des températures et la contamination par les éléments trace métalliques (ETMs) sont des sources importantes de stress pour les poissons. Les parasites ont également des effets sur la physiologie de leur hôte, mais sont rarement considérés en tant que facteurs de stress. Ces trois facteurs de stress agissent via des voies physiologiques communes (immunité, stress oxydant, métabolisme) et sont donc susceptibles d'interagir de manière complexe (e.g. antagonisme, synergisme). De plus, il existe souvent une grande variabilité des réponses entre échelles biologiques, des molécules aux populations. Notamment, l'historique d'exposition des populations de poisson dans leur milieu naturel pourrait conditionner leur capacité de réponse au stress. La prise en compte de ces deux niveaux de variabilité (i.e. interactions entre stress et entre échelles d'organisation) représente donc un verrou scientifique majeur pour mieux comprendre les effets des stress multiples sur les populations de poissons d'eau douce. Cette thèse vise donc à évaluer les effets combinés de facteurs de stress abiotique (i.e. température, ETMs) et biotique (i.e. challenge immunitaire provoqué par le parasitisme) sur les réponses des poissons d'eau douce via une approche multi-échelles. Afin de remplir ces objectifs, le Goujon (Gobio occitaniae) a été utilisé comme espèce modèle dans le cadre de trois approches méthodologiques : (i) une approche transversale de terrain visant à comparer l'état de santé de population de poissons le long des gradients de stress ; puis, (ii) des expérimentations en conditions contrôlées afin de distinguer les effets des différents facteurs de stress simples dans différentes populations sauvages ; enfin (iii) une expérience de translocation réciproque (i.e. encagement sur le terrain) entre sites contaminés et peu contaminés afin de tester l'adaptation locale des populations. Les résultats montrent que les stress simples ont des effets importants aux échelles biologiques fines et induisent la mise en place de stratégies métaboliques de compensation : les poissons investissent dans les défenses immunitaires et antioxydantes, avec une réduction des réserves énergétiques. De plus, les ajustements comportementaux (i.e. activité de nage, recherche de nourriture) sont particulièrement importants sous stress simples, et permettent d'ajuster l'acquisition d'énergie ce qui limite les effets sur la survie et la croissance. Au contraire, les stress multiples ont peu d'effets aux échelles moléculaires et cellulaires, mais provoquent des réponses complexes à l'échelle individuelle, ce qui se traduit par des effets antagonistes sur le comportement et des effets négatifs sur la survie et la croissance. Ces résultats suggèrent que sous stress multiples, les capacités de réponse des poissons pourraient être dépassées, menant ainsi à une stratégie de conservation, avec des effets délétères sur la fitness. Cependant, les réponses observées étaient fortement variables selon la population considérée. [...]Aquatic ecosystems are increasingly exposed to multiple stressors. Among them, temperature increase and contamination by trace metal elements are major stressors for freshwater fish populations. In addition, parasites and their associated immune challenges can cause a wide range of responses in fish populations, but they are still rarely considered as biotic stressors. These three stressors trigger similar physiological pathways (i.e. immunity, oxidative stress and metabolism). Hence, they are likely to interact strongly but their combined effects (i.e. antagonism and synergism) are still poorly documented, thereby hindering our ability to predict the responses of wild populations to multiple stressors under global changes. In addition, responses to stressors could vary according to the level of organisation considered (i.e molecules, cells, individuals, populations). In particular, different populations could have different sensitivity to stressors depending on their past exposure in the wild. Thus it is essential to incorporate these levels of variability to better understand and predict the effects of multiple stressors in wild fish populations. This PhD project aimed at assessing the effects of a multiple abiotic (i.e. temperature, trace metal contamination) and biotic (i.e. immune challenge) stressors across biological levels of organisation, using the gudgeon fish (Gobio occitaniae) as a model species. First, I used a cross-sectional field study in 16 wild populations to compare fish health along stress gradients. Then, I used experimental approaches under controlled conditions to disentangle the role of each single and multiple stressors across levels of organisation in different fish populations. Finally, I used reciprocal translocation experiments between polluted vs. unpolluted rivers to test for local adaptation in response to multiple stressors. Taken together, results show that single stressors affect mostly the molecular and cellular levels, in accordance with a compensatory strategy. Indeed, costly physiological defences (immunity, anti-oxidant responses) were set up and behavioural adjustments (i.e. changes in activity and foraging) enable fish to increase energy acquisition and respond adequately to single stressors, with limited deleterious effects on survival and growth. On the contrary, multiple stressors affected mostly the individual level, in accordance with a conservation metabolic strategy. Indeed, multiple stressors lead to complex antagonistic effects between stressors (i.e. antagonistic inhibition of behavioural responses), potentially due to the high energy demand incurred, resulting in deleterious effects on survival or growth. This suggests that physiological and behavioural responses might be exceeded under multiple stressors with deleterious consequences on fitness, thereby raising concerns about the effects of multiple global changes on wild populations. [...]
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Whiteman, Elizabeth Anne. "Social interactions in Caribbean cleaning gobies." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251442.
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Aguilar, Nancy Maria. "Comparative physiology of air-breathing gobies /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035402.
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Mastrorillo, Sylvain. "Profils écologiques du vairon (Phoxinus phoxinus L. ), de la loche franche (Barbatula barbatula L. ) et du goujon (Gobio gobio L. ) à l'échelle du microhabitat dans trois rivières pyrénéennes." Toulouse, INPT, 1997. http://www.theses.fr/1997INPT009A.
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Dans le piemont pyreneen, les salmonides cohabitent avec des especes dites accompagnatrices souvent numeriquement dominantes, dans un environnement soumis parfois a des evolutions complexes ou les reponses des populations de salmonides ne sont pas toujours en accord avec les previsions formulees par les modeles. L'etude approfondie des especes accompagnatrices offre une meilleure comprehension du fonctionnement ecologique des zones de piemont. La repartition du vairon, du goujon et de la loche franche a ete etudiee a l'echelle du microhabitat sur plusieurs rivieres du sud-ouest de la france (ariege, nive et gave de pau). Les poissons et les variables du milieu (profondeur, vitesse de courant, nature du substrat, type d'abris) ont ete echantillonnees par la methode de l'echantillonnage ponctuel d'abondance. Nous avons defini les profils ecologiques de ces especes en periode de basses eaux hivernales et estivales. La nature du substrat et la presence d'abris vegetaux jouent un role important dans la microrepartition de ces trois petites especes. Les variations de l'habitat disponible et de l'habitat utilise par le vairon, le goujon et la loche a la suite d'une perturbation physique du milieu (vidange) ont ete etudiees sur plusieurs stations situees en aval de retenues de la riviere ariege. Des changements significatifs de l'habitat disponible ont ete observes sur toutes les stations et ont concerne essentiellement le substrat, avec des depots important de gravier, de sable et de vase suivant les stations. Le vairon est apparu etre l'espece la plus resistante des trois et comme une espece pionniere pour coloniser des habitats nouveaux ou deteriores. Des techniques faisant appel a l'intelligence artificielle (reseaux de neurones) ont ete developpees pour modeliser et predire la presence/absence des trois especes et l'abondance du vairon a l'echelle du microhabitat a partir des variables du milieu. Les performances de prediction de presence/absence obtenues pour chaque espece sont superieures a 75 %. Un modele predictif de l'abondance de vairon est propose dont la performance de prediction atteint 92 %. Notre etude montre ainsi les avantages de l'algorithme de la retropropagation de gradient du reseau de neurones pour une approche stochastique de l'ecologie des poissons.
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Nilsson, Daniel. "Mikrolitografi för rastrerade Gobos." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2861.
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Beacon AB has been producing Gobos for some time. A Gobo is a small round sheet used in projectors almost like a slide. It is used mostly in the commercial and entertainment business. Today these Gobos are created by using a film (also called mask). A digital exposure machine called LIOS has been developed to make it possible to create Gobos using direct exposure. This means a film will no longer be necessary and it will also make the process faster and cheaper.
To be able to use LIOS in the industry a lot of work still has to be done. An image is sent to the display in LIOS. This image comes from a computer connected to LIOS and at the end of the process it will be reproduced on the Gobo. This image can be modified before it is sent to LIOS so that a better result can be achieved in the end. The problem is that once the process is complete the image will be binary, which means halftoning is going to be used. The goal of the research described in this paper is first to test the properties of LIOS, second to create a halftoning method especially designed for those properties.
The resultof this thesis is an AM (Amplitude Modulated) method that uses a modified threshold matrix. Using this method would not give a satisfying result unless some of the distortions could be corrected somehow. This can however be done using a property available for the display in LIOS. The display can handle grayscales but since etching is used later in the process the final result will be a binary image (only black and white). This means that even though the image will be binary in the end, these grayscales can still be used to improve the result. The equipment that was available when this thesis was done was not fully developed why the grayscales are used to correct distortions.
The resulting method will most likely be good enough to produce Gobos with a satisfying quality. The method has never been used before and it introduces a new way of making corrections for halftoning. There are still some practical problems left to solve before LIOS can be used to reliably produce Gobos. Using better equipment can solve several of these problems but not all of them.
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Zhou, Mian. "Gobor-boosting face recognition." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494814.
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In the past decade, automatic face recognition has received much attention by both the commercial and public sectors as an efficient and resilient recognition technique in biometrics. This thesis describes a highly accurate appearance-based algorithm for grey scale front-view face recognition - Gabor-Boosting face recognition by means of computer vision, pattern recognition, image processing, machine learning etc. The strong performance of the Gabor-boosting face recognition algorithm is highlighted by combining three key leading edge techniques - the Gabor wavelet transform, AdaBoost, Support Vector Machine (SVM). The Gabor wavelet transform is used to extract features which describe texture variations of human faces. The Adaboost algorithm is used to select most significant features which represent different individuals. The SVM constructs a classifier with high recognition accuracy. Within the AdaBoost algorithm, a novel weak learner - Potsu is designed. The Potsu weak learner is fast due to the simple perception prototype, and is accurate due to large number of training examples available. More importantly, the Potsu weak learner is the only weak learner which satisfies the requirement of AdaBoost. The Potsu weak learners also demonstrate superior performance over other weak learners, such as FLD. The Gabor-Boosting face recognition algorithm is extended into multi-class classification domain, in which a multi-class weak learner called mPotsu is developed. The experiments show that performance is improved by applying loosely controlled face recognition in the multi-class classification.
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Guo, Zhiqiang. "Séparation de niche entre deux espèces invasives de gobies." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1842/.
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Comprendre la coexistence d'espèces et le maintien de la biodiversité est depuis longtemps un point central en écologie des communautés. La notion de niche, ou théorie des niches, a été largement développée depuis l'explication par Darwin de l'impressionnante diversité de la vie sur Terre. Celle-ci est considérée comme un mécanisme majeur permettant la coexistence d'espèces compétitrice au sein des communautés écologiques. La différenciation en niches spécifiques implique des différences spatiales, trophiques, temporelles et/ou une combinaison de celles-ci. Dans cette étude, la sélection d'habitat, les traits d'histoire de vie, la composition alimentaire et les comportements alimentaires de deux espèces invasives de gobiidés, très abondantes et écologiquement similaires (Rhinogobius cliffordpopei et Rhinogobius giurinus), sont comparées afin de tester si la séparation de niches est un mécanisme qui peut potentiellement permettre leur coexistence stable dans le lac Erhai (un lac superficiel d'eau douce du plateau de Yunnan-Guizhou en Chine). Les résultats montrent qu'il y a séparation des niches de ces deux espèces le long d'un axe d'habitat, d'un axe alimentaire (pour l'habitat littoral et pour les adultes et sub-adultes), et d'un axe temporel (en termes de cycles de ponte). Spécifiquement, R. Giurinus occupe principalement les habitats profonds (PH) alors que R. Cliffordpopei occupe principalement l'habitat littoral (LH). Des analyses corrélatives ont montré que l'abondance de R. Giurinus est positivement associée avec la profondeur de l'eau et les substrats composés de sables limoneux et grossiers, tandis que la distribution de R. Cliffordpopei est corrélée aux fortes densités en macrozooplankton, les fortes abondances en autres espèces de poissons, les fortes concentrations en oxygène dissout et les fortes densités en macrophytes submergées. Concernant le partage en ressources alimentaires, les deux espèces ont montré de clairs changements au niveau de leur diète ontogénique ainsi que dans les patrons de partage des aliments qui sont significativement différents selon le stade de leur histoire de vie et les habitats. Pour les deux espèces, les juvéniles consomment principalement du macrozooplancton (cladocères et copépodes), alors que les sub-adultes et les adultes consomment principalement des larves de Chironomidae et de Tubificidae. En LH, les sub-adultes et adultes des deux espèces présentent des différences significatives dans leur régime alimentaire alors que les juvéniles ont des régimes similaires. Cependant, en PH et SH, nous n'avons trouvé aucune preuve de partage des ressources alimentaires, quelque soit le stade de vie (juvéniles, sub-adultes et adultes). R. Cliffordpopei et R. Giurinus présentent un partage de leur niche temporel. En effet, les deux espèces ont des débuts de période de reproduction ainsi que des pics de reproduction à des moments différents. R. Cliffordpopei se reproduit de Février à Juin avec un pic de ponte entre Mars et Avril alors que l'activité de reproduction de R. Giurinus se fait entre Avril et Août avec un pic de ponte pendant les mois de Mai et Juin. Ces différences ont conduit à un partage temporel des cohortes de taille similaire entre les deux espèces, en particulier pour les larves de petite taille et les juvéniles, qui sont presque exclusivement zooplanctivores et qui exploitent les mêmes ressources alimentaires dans le lac. Cependant, l'activité nycthémérale (activité de locomotion) et le rythme d'alimentation varient légèrement entre les deux espèces, i. E. Les deux espèces présentent deux pics d'activités (6:00 - 10:00 et 18:00 - 22:00) et deux principales périodes d'alimentation (6:00 - 10:00 et 18:00 - 22:00) sur un laps de temps de 24h pour les quatre saisons. De plus, notre étude apporte une compréhension complète de la sélection d'habitat et des traits d'histoire de vie (i. E. Patron de croissance, biologie de la reproduction et dynamique de population) de ces deux espèces invasives de gobies. Ces résultats biologiques sont essentiels pour la mise en place de programmes économiquement et écologiquement efficaces de contrôle pour les deux espèces de ravageurs. De nouveau programmes de gestion sont fortement recommandés en vue de ces résultats. Par conséquent, dans cette étude, plusieurs programmes de restauration spécifiques et innovants sont proposés pour améliorer les stratégies actuelles de gestion dans une perspective de réduction des coûts et une meilleure efficacitéUnderstanding species coexistence and maintenance of biodiversity in nature has long been a central issue in community ecology. The niche or niche-based theory has been developed since Darwin's explanation of an amazing diversity of life on the Earth and considered as a major theory explaining the coexistence among competing species within ecological communities. Niche differentiation basically involves spatial, trophic, temporal and/or a combination of them. In the present study, habitat selections, life-history characteristics, diet compositions and feeding behaviors of two highly abundant and ecologically similar invasive goby species (Rhinogobius cliffordpopei and Rhinogobius giurinus) are compared to test whether niche separation is a potential mechanism allow ing the stable coexistence of them in Lake Erhai (a shallow freshwater lake in the Yunnan-Guizhou Plateau of China). The results demonstrated that these two species showed niche separation along habitat axis, food axis (in littoral habitat for sub-adults and adults), and temporal axis in terms of spawning cycles. Specifically, R. Giurinus mostly occupied profundal habitat (PH) while R. Cliffordpopei mainly used littoral habitat (LH). Correlation analyses revealed that the abundance of R. Giurinus was positively associated with deep water, silt and coarse sand substrata, whereas the distribution of R. Cliffordpopei was positively associated with high densities of macrozooplanktons and high abundances of other fish species, high concentration of dissolved oxygen and high densities of submerged macrophytes. For food resources partitioning, they showed a clear ontogenetic diet shifts and significantly different food partitioning patterns at different life-history stages and habitats. For both species, macrozooplanktons (Cladocera and Copepoda) were the main food for juveniles while sub-adults and adults primarily consumed Chironomidae larvae and Tubificidae. In LH, sub-adults and adults of the two species significantly differed in their diet compositions while juveniles showed similar diets. In PH and SH, however, there was no evidence for food partitioning between species at all the three life-history stages. R. Cliffordpopei and R. Giurinus showed temporal niche partitioning as they exhibited different onsets of spawning and peaks of spawning seasons, and thus different growth and population dynamics, though both of them are short-lived species with a life span of about one year. R. Cliffordpopei spawned from February to June with a spawning peak occurring in March and April. Spawning activity of R. Giurinus occurred from April to August with a peak activity during May and June. These differences resulted in a temporal partitioning for similar-sized cohorts, especially for small-sized larvae and juveniles, which were almost exclusively zooplanktivorous and exploited the same food resources in the lake. Moreover, their different spawning cycles led to different peak seasons for the highest population density of the two species. However, the diel activity (locomotory activity) and feeding rhythm varied slightly between them, i. E. Both species showed two peaks of activity (6:00 - 10:00 and 18:00 - 22:00) and two main feeding periods (6:00 - 10:00 and 18:00 - 22:00) in the four seasons. Moreover, our study provides a full understanding of habitat selection and life-history characteristics (i. E. Growth pattern, reproduction biology and population dynamic) of the two invasive gobies. These findings are crucial biological aspects for an economically and ecologically effective control programs to the two abundant pest species. The further management programs are highly recommended to give a careful consideration of these findings. Therefore, several specific remediation is suggested to improve the current management strategies from the perspective of cost-efficiency
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Yamasaki, Yo. "Species diversification through parallel freshwater adaptation in Rhinogobius gobies." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225433.
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Wilson, Jacqueline A. "Habitat quality, competition, and recruitment processes in two marine gobies." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004180.
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kassak, Mohamad, and Gary Wiklund. "Gobo I Hemmet." Thesis, Högskolan i Jönköping, Tekniska Högskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-15494.
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Lederhouse, Terra M. "Naked gobies (Gobiosoma bosc) as indicators of oyster reef restoration success." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9243.
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Thesis (M.S.) -- University of Maryland, College Park, 2009.Thesis research directed by: Dept. of Biology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Neilson, Matthew. "Evolution, systematics, and phylogeography of Ponto-Caspian gobies (Benthophilinae: Gobiidae: Teleostei)." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1260565938.
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Kielbassa, Janice. "Mathematical modelling of temperature effects on the life-history traits and the population dynamics of bullhead (Cottus gobio)." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10181.
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La température de l'eau joue un rôle majeur dans le cycle de vie des poissons. Dans un contexte de changement climatique global, le réchauffement peut avoir un impact fort sur la croissance, la fécondité et la survie. L'enjeu de cette thèse est la modélisation mathématique de l'influence de la température sur les traits d'histoire de vie d'une population de chabot (Cottus gobio) afin de faire de la prédiction à la fois au niveau individuel et populationnel. Les données expérimentales qui permettront de calibrer les modèles sont issues du bassin de la Drôme (France) et plus particulièrement du sous-bassin du Bez. Dans une première étape, il s'agit de développer un modèle de rétrocalcul qui peut être utilisé pour calculer les longueurs individuelles des chabots aux âges précédents à partir des données mesurées à la capture. Il s'agit, dans un deuxième temps, de développer un modèle de croissance dépendant de la température de l'eau qui sert à prédire la longueur moyenne des chabots à un âge donné. Enfin, il s'agit de passer de l'échelle de l'individu à celle de la population en prenant en compte tous les traits d'histoire de vie et leurs dépendances vis-à-vis de la température. Plus précisément, un modèle matriciel de type Leslie, à la fois dépendant du temps et de la température, structuré en classe d'âges est développé et utilisé pour prédire la dynamique de population sous différents scénario du réchauffement climatiqueWater temperature plays a key role in the life cycle of fish. Therefore, increasing temperatures due to the expected climate change may have a strong impact on growth, fecundity and survival. The goal of this thesis is to model the impact of temperature on the life-history traits of a bullhead population (Cottus gobio) in order to make predictions both at individual and at population level. The models developed here are calibrated on experimental field data from a population living in the Bez River network (Drôme, France). First, a new back-calculation model is derived that can be used to compute individual fish body lengths at earlier ages from capture data. Next, a growth model is proposed that incorporates the water temperature and can be used to predict the mean length at a given age and temperature. Finally, the population is modelled as a whole by linking all life-history traits to temperature. For this purpose, a spatialised time- and temperature-dependent Leslie matrix model structured in age classes was used to predict the population dynamics under different temperature scenarios
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Faria, Cláudia Barreiros Macedo de. "Distribuição vertical e ocupação diferencial do habitat de Lipophrys pholis (blenniidae), Coryphoblennius galerita (blenniidae), Gobius cobitis (gobiidae) e Gobius paganellus (gobiidae), na plataforma rochosa da costa do Estoril." Master's thesis, Instituto Superior de Psicologia Aplicada, 1995. http://hdl.handle.net/10400.12/500.
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Dissertação de mestrado em EtologiaNeste trabalho apresenta-se uma abordagem eto-ecológica das espécies Lipophrys pholis (Blenniidae), Coryphoblennius galerita (Blenniidae), Gobius cobitis (Gobiidae) e Gobius paganellus (Gobiidae) na plataforma rochosa da Costa do Estoril. Analisaram-se concretamente os problemas referentes à caracterização dos habitais preferenciais de cada espécie, ao estudo da distribuição dos indivíduos de cada espécie segundo a sua dimensão, à caracterização dos locais de nidificação, ao estudo do comportamento de selecção do substrato que cada espécie apresenta em aquário, ao estudo dos padrões de organização social e dos comportamentos agonísticos que afectam a competição intraespecífíca e finalmente ao estudo da importância dos comportamentos agonísticos interespecífícos como mecanismo de separação de habitat entre as espécies. Verifícou-se que nas populações estudadas, ocorre uma diferenciação nítida do habitat ocupado pelas espécies de cada família estudada, Gobiidae e Blenniidae, quer no que se refere aos locais de nidificação (pedras/abrigos na rocha), quer ao habitat utilizado pelos juvenis e adultos (canais/poças e abrigos na rocha), que poderá resultar de uma série de constrangimentos morfológicos, comportamentais, alimentares e provavelmente fisiológicos, característicos das espécies de cada família. Constatou-se que em habitais frequentados por mais do que uma espécie, ocorre também uma diferenciação do microhabitat utilizado, quer ao nível dos locais de nidificação, quer ao nível do habitat utilizado pelos juvenis e adultos, o que poderá estar relacionado com a dimensão típica de cada espécie, os diferentes hábitos alimentares e com a capacidade que cada espécie apresenta em tolerar diferentes graus de exposição à turbulência e acção das ondas. Relativamente às duas espécies de biénios estudadas, constatou-se que C.galerita é uma espécie altamente especializada, tanto ao nível alimentar como ao nível do microhabitat, recrutando para as mesmas poças onde permanece mesmo depois de atingir a maturidade sexual, ao contrário de L.pholis que é uma espécie mais generalista, a ambos os níveis considerados, sofrendo uma distribuição diferencial segundo a dimensão dos indivíduos, coexistindo com C.galerita apenas na fase de imaturo (de 3 a 7cm de dimensão). Os dados obtidos em aquário, sugeriram que apesar de em grupos monoespecífícos, a ordem de dominância ser determinada pelo tamanho dos indivíduos, em grupos heteroespecífícos, é o factor espécie a assumir essa função (dentro de certos limites de tamanho), sendo C.galerita a espécie dominante, seguida de L.pholis e por último G. cobitis. Enquanto que G.cobitis apresenta logo à partida uma preferência distinta por substrato de areia, ambas as espécies de biénios (com dimensões entre 3 a 7cm), apresentam preferências semelhantes entre si, por substrato de rocha e abrigos na rocha, o que sugere a existência de competição interespecífica, entre estas duas espécies. Observou-se que L.pholis altera radicalmente as suas preferências, quando em presença de C.galerita, sendo "empurrado" para o substrato de maior exposição (areia), o que poderá sugerir que, na natureza, a competição interespecífica actue ao nível da separação do microhabitat entre estas duas espécies. Ainda do estudo em aquário, verificou-se que cada espécie apresenta um reportório comportamental específicos e bem adaptado ao tipo de microhabitat em que vive, observando-se uma maior semelhança entre as duas espécies de biénios, ao nível dos comportamentos agonísticos estudados. Foi sugerido que a pressão de selecção que estas duas espécies sofreram, no sentido de diminuírem a agressividade nos encontros agonísticos, foi semelhante entre si, e mais acentuada que no caso de G.cobitis. Finalmente, verificou-se que em Portugal todas as espécies estudadas se reproduzem mais cedo e durante mais tempo, que em zonas de maior latitude, o que aliado à ocorrência de um crescimento mais rápido, observado em ambas as espécies de biénios, parece permitir que em Portugal estas espécies atinjam a maturidade sexual mais cedo que em países de maior latitude, maximizando assim o seu potencial reprodutor
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Brown, Joshua Evan. "Genetic Portraits of Introduced Gobies and Mussels: Population Variation Delineates Invasion Pathways." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1261147796.
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Gobien, Simone [Verfasser], and Michael [Akademischer Betreuer] Kirk. "Land Matters. An Impact Evaluation in Developing Countries / Simone Gobien. Betreuer: Michael Kirk." Marburg : Philipps-Universität Marburg, 2015. http://d-nb.info/1074639537/34.
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Naser, Tim, and Stavros Ntouvas. "Gobi : Automatic sand-spreading robot." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296306.
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The purpose of this report was to research through the construction of a prototype the technical challenges associated with creating a robot that distributes sand on patios after snowfall. A robot that could complete this task should be able to know its position in an unknown terrain and traverse it in a predictable manner that allows for the even spread of the sand. In order to achieve stability and predictability of movement, stepper motor driven wheels were chosen as the steering method. The sand-spreading mechanism consists of a DC Motor connected to a 3D-printed disc with rectangular extrusions at its base. The wheels and chassis of the robot were likewise 3D-printed. Lastly, an Arduino MEGA board was the controller of choice.Syftet med denna rapport var att genom konstruktionen aven prototyp undersöka de tekniska utmaningarna för att skapa en robot som distribuerar sand på uteplatser efter snöfall. En robot som kan slutföra denna uppgift bör kunna känna till sin position i en okänd terräng och färdas på den på ett förutsägbart sätt som möjliggör en jämn spridning av sanden. För att uppnå stabilitet och förutsägbarhet för rörelse valdes stegmotordrivna hjul som styrmetod. Sandspridningsmekanismen består av en likströmsmotor ansluten till en 3D-utskriven skiva med rektangulära extruderingar vid basen. Robotens hjul och chassi var också 3D-utskrivna. Slutligen var ett Arduino MEGA-kort den valfriastyrenheten.
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Gosselin, Marie-Pierre. "Aquatic habitat characterization and use in groundwater versus surface runoff influenced streams : brown trout (Salmo trutta) and bullhead (Cottus gobio)." Thesis, Coventry University, 2009. http://curve.coventry.ac.uk/open/items/8d69e5ee-5c54-1d43-2390-e9bea23aad35/1.
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Riverine physical habitats and habitat utilization by fish have often been studied independently. Varying flows modify habitat composition and connectivity within a stream but its influence on habitat use is not well understood. This study examined brown trout (Salmo trutta) and bullhead (Cottus gobio) utilization of physical habitats that vary with flow in terms of size and type, persistence or duration, and frequency of change from one state to another, by comparing groundwater-dominated sites on the River Tern (Shropshire) with surface runoff-dominated lowland, riffle-pool sites on the Dowles Brook (Worcestershire). Mesohabitat surveys carried out at two-month intervals on a groundwater-dominated stream and on a surface runoff-influenced stream showed differences in habitat composition and diversity between the two types of rivers. The temporal variability in mesohabitat composition was also shown to differ between the two flow regime types. In the groundwater-influenced stream, mesohabitat composition hardly varied between flows whereas in the flashy stream it varied to a great extent with discharge. Habitat suitability curves for brown trout and bullhead were constructed to predict the potential location of the fish according to flow. The resulting prediction maps were tested in the field during fish surveys using direct underwater observation (snorkelling). Under the groundwater-influenced flow regime brown trout displayed a constant pattern of mesohabitat use over flows. Mesohabitats with non-varying characteristics over flows and with permanent features such as large woody debris, macrophytes or any feature providing shelter and food were favoured. Biological processes, such as hierarchy, life cycle and life stage appeared to play a key role in determining fish habitat use and to a greater extent than physical processes in these streams. Bullhead observations in the flashy river showed that mesohabitat use varied with flow but that some mesohabitats were always favoured in the stream. Pools and glides were the most commonly used mesohabitat, due to their stability over flows and their role as shelter from harsh hydraulic conditions and as food retention zones. The presence of cobbles was also found to be determinant in bullhead choice of habitat. In this flashy environment, physical processes such as flow and depth and velocity conditions appeared to be a more decisive factor in bullhead strategy of habitat use than biological processes. This research shows that: 1. Though differences in habitat use strategies between the two flow regimes can in part be attributed to differing ecology between the species, flow variability affects fish behaviour. 2. A stable flow regime allows biological processes to be the main driving force in determining fishbehaviour and location. A highly variable environment requires fish to develop behaviour strategies in response to variations in hydraulic conditions, such as depth and velocity, which constitute the key factor in determining fish location.
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Schneeberger, Hans Urs. "Abklärungen zum Gesundheitszustand von Regenbogenforelle (Oncorhynchus mykiss), Bachforelle (Salmo trutta fario) und Groppe (Cottus gobio) im Liechtensteiner-, Werdenberger- und Rheintaler-Binnenkanal /." [S.l.] : [s.n.], 1995. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Kay, Benjamin W. "Does predation/disturbance by benthic-feeding gobies influence the infauna on Heron Island reef flat /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18994.pdf.
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Fowler, Vivienne Frances. "The impacts of chemical discharges on the reproductive biology of the bullhead Cottus gobio and the dipper Cinclus cinclus in the Tamar catchment." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3092.
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It is now well established that a wide range of natural and anthropogenic chemicals present in the aquatic environment have the potential to disrupt the endocrine system of many organisms. In fish, many of these effects appear to be of a feminising nature, including stimulation of vitellogenin production and induction of intersex. In piscivorous birds these so called endocrine disrupting contaminants have been shown to impair reproduction, influencing reproductive behaviour, sex ratio, eggshell thickness and reproductive success. The effects seen in fish have been associated with high levels of oestrogenic activity in the effluent from waste water treatments works (WwTWs), but few studies have focused on the effects of WwTWs effluents on birds. In this thesis, the effects of effluents from WwTWs on fish and birds were investigated in the Tamar catchment, SW England. The work spanned making detailed assessment on the oestrogenic and anti-androgenic activity of 3 WwTWs effluents, using a variety of water sampling techniques and applying both recombinant yeast oestrogen screen (YES) and recombinant yeast androgen screen (anti-YAS) bioassays to quantify the different hormonal activities. A survey was undertaken of the hormonal activities at 13 sites to determine concentrations of contaminants in the surface waters throughout the Tamar catchment, using both recombinant yeast screens and targeted analytical chemistry for specific pollutants (LC/MS-TOF and GCMS). An ELISA was developed to quantify vitellogenin (VTG) in the bullhead (our study fish sentinel) as a biomarker of oestrogen exposure, and evidence of endocrine disruption was investigated in wild populations of the bullhead, Cottus gobio and the dipper, Cinclus cinclus. Macroinvertebrates from upstream and downstream of three WwTW's effluent discharges and from three sampling sites were also sampled as an index of overall water quality in the Tamar catchment, and as an assessment of food availability for the bullheads and dippers. For the studies on the hormonal activities in three WwTWs in the Tamar catchment, samples were collected by both spot and passive sampling; passive samplers (in replicate) were placed in the effluent discharges for a three week period, and collected on days 7, 14 and 21, spot samples were taken simultaneously. Measurement of total oestrogenic and total anti-androgenic activity was conducted using the YES and anti-YAS, respectively. Spot and passive samples were collected from 13 sites within the Tamar catchment (sampling sites were >2 km downstream of effluent discharges). Additionally, liquid chromatography mass spectrometry time-of-flight (LC/MS-TOF) was used to measure the concentration of oestrone (E1), 17β-oestrodiol (E2) and 17α-ethinylestradiol (EE2) in each sample. Gas chromatography mass spectrometry (GCMS) was used to measure the concentration of individual PBDE and PCB congeners in the spot samples only. Levels of oestrogenic and anti-androgenic activity observed in the WwTWs effluent were comparable with those measured in effluents in the UK and in other countries. Surface waters of the Tamar, away from the WwTWs effluent discharges, contained very little oestrogenic activity (<1.1 ng E2 EQs L-1), and anti-androgenic activity was undetectable. Quantification of oestrogenic activity using passive samplers showed an increasing amount of total oestrogenic activity between days 7 and 21 when measured by the both the YES and LC/MS-TOF. Low levels of PBDE congeners 47, 99, 100, 138 and 153 were detected in the spot samples taken from the Tamar catchment, with BDE 47 being the most abundant. In contrast PCBs were undetectable. Neither PBDEs nor PCBs were detected in any of the extracts from the passive samples. No assay was available to measure VTG (one of the most widely used biomarkers of oestrogen exposure in fish) in the bullhead and so an enzyme linked immunosorbant assay (ELISA) was developed for application to studies on wild bullheads in the Tamar catchment. The bullhead vitellogenin (bh-VTG) ELISA was developed successfully, and proved to be sensitive and robust, with a detection range between 10.5 and 300 ng bh-VTG mL-1 (undiluted), comparing favourably with other fish VTG ELISAs. Plasma VTG concentrations measured in male bullheads (collected from the same sites as for the water samples) ranged from below the limit of detection to 990 ng bh-VTG mL-1. Whether these upper levels in the range reflected VTG induction was difficult to conclude. Because of this controlled caged exposures with bullheads and trout were used to assess the relative levels of oestrogenicity in two key WwTWs effluent discharges and to determine the response sensitivity of the bullheads (and trout) to those effluents. These controlled exposures found no responses in plasma VTG in bullheads (ranging between 126 and 934 ng bh-VTG mL-1) suggesting a lack of sensitivity for VTG induction. This was supported by the inability to induce VTG in fish held in the laboratory and treated with steroidal oestrogens. For the effluent exposures on the caged rainbow trout, it was also found that there was no significant induction of VTG, a species normally sensitive to oestrogens. These findings may indicate that the fish were highly stressed due to the river being in spate and the movement of the cages during the controlled exposures. It may also be the case, however, that the use of immature female rainbow trout with a highly variable baseline plasma VTG concentration may prevent any detection of a response. There were no signs of sexual disruption in any of the gonads analysed from either male or female wild bullheads, demonstrating that any hormonal activity present in the catchment away from the WwTWs effluents was not sufficient to induce adverse effects on reproductive development. An interesting feature noted in the male testes of the bullheads was the presence of spermatid masses, which have been recorded in 10 other Cottidae species, but not previously in the bullhead. For the studies on dippers, eggs were collected from the nests of breeding dippers to measure for sperm numbers and morphology from sperm trapped in the perivitelline membrane (PVM), and the yolks were analysed for PBDEs, PCBs and organochlorine pesticides (OCPs) by GCMS, for E1, E2, and EE2 by LC/MS-TOF. Eggs of the dipper were collected from nests at the 13 sampling sites, plus an additional three sites and over three years of field study. The number of sperm trapped in the PVM ranged between three and 188, with a mean of 68.78 ± 8.78 SE. Dipper sperm had not previously been characterised, and was found to be similar to other passerine sperm, in that the head was helical, complemented by a mitochondrial helix or keel, which continued in a spiral around the flagellum. Sperm were classed as ‘abnormal’ if they did not adhere to this typical structure. No assessment of motility could be made in relation to the structural abnormalities seen. Contaminants in the dipper eggs were dominated by BDE 99, an unusual result considering the dippers aquatic lifestyle. PCB 153 was the most common PCB, and p,p’-DDE was the most abundant OCP; all other pesticides tested were below the limit of detection, as were the levels of all three steroid oestrogens. There was inter- and intra-nest variability between contaminant burdens in all eggs as well as the number of sperm trapped in the PVM, but there was no relationship between sperm number and the level of contaminant loadings in the eggs. There were no correlations between contaminants and oestrogenic activity measured in the water samples, and plasma VTG concentrations in bullheads or contaminant loadings in eggs, or indeed sperm number. Analysis of macroinvertebrate assemblages proved that the surface waters of the Tamar catchment were of ‘very good’ quality, even in close proximity to WwTWs effluent discharges.
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Cheney, Karen L. "Interactions between Caribbean cleaning gobies (Elacatinus sp.) and territorial damselfish : costs, benefits and effects of scale." Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399766.
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Maddox, Elizabeth D. "Generic Identification and Patterns of External Pigment in Larval Gobies (Pisces: Gobiidae) from the Belize Barrier Reef." W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539617646.
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Meirelles, Maria Eugênia. "Viabilidade do cultivo do neon gobi, Elacatinus figaro." Florianópolis, SC, 2008. http://repositorio.ufsc.br/xmlui/handle/123456789/91529.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-graduação em AquiculturaMade available in DSpace on 2012-10-23T23:57:47Z (GMT). No. of bitstreams: 1 258942.pdf: 978765 bytes, checksum: 9a6438291eb1dd3b55921573c67930dd (MD5)
Atualmente, existe uma grande demanda por peixes ornamentais marinhos destinados à indústria da aquariofilia. A realidade extrativista e altamente seletiva desta atividade leva a um alto risco de sobre-explotação dos recursos naturais. Uma alternativa para diminuir o extrativismo destes peixes, especialmente os ameaçados de extinção, é o desenvolvimento de tecnologia para a produção desses animais em cativeiro. O presente trabalho tem como objetivo desenvolver tecnologia para a produção massiva do neon gobi, Elacatinus figaro, uma espécie de peixe ornamental marinho nativo ameaçado de extinção. Ao longo de 7 meses foram obtidas 52 desovas e 41 larviculturas do neon. Animais selvagens iniciaram a formação de casais 20 dias após a aclimatação às condições de cativeiro. As desovas iniciaram-se após 12 dias de pareamento, e ocorreram de forma freqüente. A fêmea desova de 140 a 700 ovos num intervalo de 11 dias, em média. O período de incubação dos ovos durou em média 6,8 dias a 25 ºC. As melhores taxas de eclosão dos ovos e sobrevivência das larvas obtidas foram de 99,5% e 30,6%, respectivamente. Como principais resultados, destaca-se a geração de conhecimentos sobre a bioecologia desta espécie de peixe ornamental marinho, bem como o desenvolvimento de tecnologia produtiva para a espécie em questão.
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Uumati, Martha. "Acoustic investigations on bearded goby and jellyfish in the northern Benguela ecosystem." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4469.
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Historically the nutrient rich Benguela ecosystem supported large stocks of commercially important fish which sustained the Namibian fishing sector. Recently, non-exploited species i.e. bearded goby (Sufflogobius bibarbatus) and jellyfish (Chrysaora fulgida and Aequorea forskalea) have become more apparent and are described as key-species in this ecosystem. Empirical evidence for understanding the stock abundance and dynamics of S. bibarbatus and jellyfish are still sparse, as research focus has been mainly on commercially important fish. The abundance of these non-exploited species in relation to the environment and commercial species are also not well understood. Lack of methods to effectively assess jellyfish and S. bibarbatus have furthermore limited our knowledge. Acoustics can cover large water volumes and observe many trophic groups and interactions simultaneously hence currently proposed as the most reliable observation tool available to remotely study multiple species that are overlapping and widely distributed in marine ecosystems. For acoustic assessments using echo sounders, the ability to detect, identify and distinguish targets from each other and the echo ability (target strength: TS) of individual targets is pivotal to convert acoustic data from a calibrated system into significant biological measures. The lack of effective acoustic identification (ID) techniques and knowledge about TS of species may limit the application of acoustics. The swimbladder generally contributes more than 90% to the backscattered energy from fish, which makes knowledge of the swimbladder vital for understanding the acoustic properties of a fish. Prior to this study, the presence or absence of a swimbladder within S. bibarbatus has been uncertain. This thesis is an exploratory study addressing 1) the acoustic identification challenge of species in aggregating in mixed assemblages and 2) the acoustic characteristics of the target species. The latter two are of essence to assess the biomass, distributions and ecological interactions of these non-exploited. The multiple frequency data (18, 38, 70, 120 and 200 kHz) and trawl data used in this study were collected on a survey conducted by the RV G.O.Sars during April 2008 in the northern Benguela. Fifteen validated assumed to be ‘single species' trawl and acoustic datasets were selected and used in the application and developing of ID techniques. Traditional acoustic identification techniques (Sᵥ-differencing and relative frequency response r(f)) were adopted and found ineffective as standalones to discriminate the species under study. The overlaps in the Sᵥ differences of the three species complicated separation. A multivariate statistical approach, Linear Discriminant Analysis (LDA) was applied to predict which of the variables s[subscript(A)], S[subscript(A)], Δs[subscript(A)] and r(f) discriminated the three species groups from each other with a higher accuracy. It was found that by combining backscattering strength S[subscript(A)] and r(f) a correct classification accuracy of up to 95% could be obtained. Limitation is that the LDA technique as any classification method is not applicable in “real time” during surveys. A new technique, here within referred to as the Separator Technique, which incorporates the standard techniques, LDA results, a novel r(f) similarity comparison technique and a threshold s[subscript(A)] response technique was established. The effectiveness of the Separator Technique is in the recognition of similarities and stability in frequency response by simple correlation of the observed frequency response at systematic Sᵥ-threshold levels. Accurate acoustic classification depends on good and valid training datasets and there has so far not been a simple way of acoustically detecting if the selected assumed “pure” datasets is contaminated or not. Only available reliable source are the trawl samples. The r(f) similarity comparison method showed that some of the assumed ‘single species' trawls were mixed and that presence of <1% of strong scatterers could mask a weaker scatterer. By evaluating the threshold s[subscript(A)] frequency response, the proportion of thresholded backscattering could be quantified. A frequency which is more appropriate for the acoustic assessment of the respective species in mixed aggregations could also be identified. Further improvements of the Separator Technique are required in terms of the precise Sᵥ-cut levels. The presence of S. bibarbatus' swimbladder was confirmed from two thawed specimens. From further investigations on 26 dissections of sampled S. bibarbatus, the swimbladder was identified as a physoclist (closed swimbladder) with an extensive gas gland, and its morphology was roughly described as prolate spheroid shaped and with about 5ᴼ negatively tilted compared fish vertebra. This means that the strongest echo from a goby will be found when the fish is at about 5ᴼ head down relative to the horizontal. The in situ TS of 8 cm sized S. bibarbatus and the two jellyfish species: C. fulgida [umbrella diameter: 21.7 cm] and A. forskalea [16 cm] at multiple frequencies (18, 38, 70, 120 and 200 kHz) was estimated. At 38 kHz, the TS was -53 dB for S. bibarbatus, -58 dB for A. forskalea and -66 dB for C. fulgida. The single echo detection (SED) approach which is assumed to be a more accurate method for estimating TS than the previously applied methods for jellyfish. The TS results for S. bibarbatus are of similar magnitude to other published TS values of C. fulgida. This suggests that estimates of jellyfish may be overestimated due to inaccuracies in target identification. This thesis established the acoustic characteristics of jellyfish and S. bibarbatus within the northern Benguela which makes it possible to acoustically assess and monitor jellyfish and/or fish. The identification technique though still in early phases of development, can be applied to enhance quality of training datasets (samples) used in classification. This piece of work can reduce variability in biomass estimates that arises from masking or misclassification of echoes.
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Abdoli, Asghar. "Rôle de la température dans la variabilité des traits d'histoire de vie : le cas du chabot (''Cottus gobio L.'') à l'échelle d'un réseau hydrographique (Bez, France)." Lyon 1, 2005. http://www.theses.fr/2005LYO10050.
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L'augmentation de la température des eaux continentales suite à un réchauffement climatique provoquera probablement des changements de traits d'histoire de vie et de distribution géographique des poissons dulçaquicoles. Dans cette étude, l'hypothèse d'un lien entre les traits d'histoire de vie et les variables environnementales (et plus particulièrement la température) a été testée grâce à des comparaisons inter-sites à l'intérieur d'une population de chabots (Cottus gobio, espèce benthique colonisant préférentiellement des eaux froides) présentant une structuration spatiale marquée. Nos résultats démontrent qu'une augmentation modérée de température (3 degrés, ce qui correspond aux changements thermiques prédits par les scénarii IPCC) sur des populations de chabots spatialement structurées affecteraient fortement leurs traits d'histoire de vie, leur structure en âges et leur densité. Des suivis à long terme sur le terrain ainsi que des études expérimentales complémentaires sont toutefois nécessaires pour confirmer ces conclusions
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Sternberg, Troy. "Nomadic geography : pastoral environments in the Gobi Desert, Mongolia." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:bc3b363d-5d7a-4b4c-896d-4296ba99cf43.
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Pastoralism on the Mongolian steppe encompasses limited physical resources and evolving anthropogenic influences. Little-studied, the Inner Asian region encounters changing climates, evolving land use practices, and socio-economic transition that impact the natural and human geography. This thesis investigates how bio-physical factors and herder action determine the pastoral environment in the Gobi Desert, Mongolia. Research, focusing on drought, degradation and the extreme winter conditions that define pastoralism in Mongolia, examines pastoralists' perception of and interaction with their environment. This approach highlights steppe ecological and social processes within the global dryland debate. Fieldwork in Omnogovi and Ovorhangai Province established that drought is endemic in the region. However, drought events were independent of extreme winter conditions and did not exacerbate their impact. Degradation was not found at water points as vegetation cover decreased with distance from water. While remote sensing showed a decline in vegetation cover over time, it did not establish desertification on the steppe. Changing physical, socio-economic, and political conditions since 1990 continue to impact Mongolian pastoralism. Environmental conditions, particularly water resources and pasture quality, were paramount herder concerns. This research showed that pastoralists are economically motivated, differentiate on multiple dimensions, and value communal land stewardship. On the steppe, traditional mobile livestock practices improve livelihoods and remain an effective management approach. However, the future of pastoralism is uncertain as herders settle, the population ages, and children become educated. Thesis results emphasize the interaction of physical and social environments will define pastoralism's role in the Gobi Desert
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Tate, Julie F. "Feeding Practices of Mothers in the Gobi Desert of Mongolia." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1228.
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The diets of Mongolia infants are deficient in vitamins and minerals and complementary foods are introduced too early. Breastfeeding is the best source of nutrition for infants until 6 months of age. A survey of 50 Mongolian mothers with children under the age of 5 in the town of Sainshand, Dornogobi, was conducted in July 2011. Mongolian infants are among the highest percent of infants in the world who are exclusively breastfed for the first 6 months of their lives, thus providing them with excellent nutrition. However, complementary feedings and supplements are not appropriately used or understood. Therefore, the diets of Mongolian infants are still lacking key nutrients and they are exposed to complementary foods too soon. By obtaining more information on the feeding practices of Mongolian mothers, better education materials and seminars on infant nutrition can be developed, which will improve the overall nutrition and health of the children of Mongolia.
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Wang, Xianjie. "Interactions of ozone and acetic acid with natural Gobi dust." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS412.
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Cette thèse de doctorat porte sur l’étude des interactions de l'ozone et de l'acide acétique avec des poussières minérales naturelles du désert de Gobi en Chine, à température ambiante, pression atmosphérique ainsi que dans des conditions sèches et humides. Les espèces en phase gazeuse et en phase adsorbée sont caractérisées par des techniques post-situ et in-situ. La capture de l’ozone par les poussières de Gobi est étudiée sur une large gamme de concentrations (20 ppb – 10 ppm) afin de clarifier les processus hétérogènes impliquant l'ozone et évaluer leurs implications en chimie atmosphérique et dans les procédés. Les poussières de Gobi présentent des propriétés catalytiques de décomposition de l'ozone avec un coefficient de capture stationnaire variant entre 2.6 10-9 et 6.2 10-8 selon la concentration d’ozone. Les molécules d'eau rivalisent avec l'ozone pour l’accès aux sites de surface, tandis que le traitement thermique à 150 °C peut régénérer de manière significative certains sites de surface après une exposition à l'ozone. Les modes d'interaction physisorptifs et chimisorptifs de l'acide acétique sur les poussières de Gobi sont ensuite étudiés: l’acide acétique s’adsorbe sous forme de monomère et dimère, ainsi que d'acétate bidentate. La quantité ainsi que la répartition des fractions réversibles et irréversibles d'acide acétique absorbées présentent des comportements différents entre conditions sèches et humides. Enfin, l'ozonation de l'acide acétique adsorbé sur les poussières de Gobi est étudiée pour évaluer l'aptitude de ce géo-matériau à être utilisé comme catalyseur d'intérêtThis PhD thesis investigates the interactions of ozone and acetic acid with a natural mineral dust from Gobi Desert in China, under room temperature, atmospheric pressure, dry and wet conditions, using post-situ and in-situ characterization techniques to address gas phase and adsorbed phase species. First, ozone uptake at the surface of Gobi dust is investigated over a large ozone concentration range (20 ppb – 10 ppm) to provide new insights on the heterogeneous processes of ozone with potential interest for both atmospheric chemistry and industrial frameworks. Gobi dust exhibits catalytic properties regarding ozone decomposition with a steady-state uptake coefficient ranging from 2.6 10-9 to 6.2 10-8 depending on ozone concentration. Water molecules compete with ozone for the same surface sites while thermal treatment at 150˚C can significantly regenerate the surface sites after surface exposure to ozone. Second, the physisorptive and chemisorptive interaction modes of acetic acid on Gobi dust have been studied evidencing the formation of molecularly adsorbed acetic acid in monomer and dimer forms as well as bidentate chelating acetate. The amount and the partition of reversibly and irreversibly adsorbed fractions of acetic acid taken up on Gobi dust exhibit contrasted behaviors under dry and 20% RH conditions. Finally, the oxidation of adsorbed acetic acid by ozone at the surface of Gobi dust is investigated to typify the ability of that geo-material to act as a catalyst of interest
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Gobin, Oliver Christian [Verfasser], Klaus [Akademischer Betreuer] Köhler, Harald [Akademischer Betreuer] Klein, and Johannes A. [Akademischer Betreuer] Lercher. "Transport in Nanoporous Solids / Oliver Christian Gobin. Gutachter: Klaus Köhler ; Harald Klein. Betreuer: Johannes A. Lercher." München : Universitätsbibliothek der TU München, 2011. http://d-nb.info/1012187438/34.
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Casadei, Nicola. "Sistemi di Visione Artificiale: sviluppo di un prototipo per il controllo qualità nella produzione di Gobos." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14715/.
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Il controllo della qualità è un passaggio fondamentale del processo produttivo industriale.
Le aziende sono sempre più interessate a migliorare e ottimizzare questa fase, utilizzando anche le più moderne tecnologie.
L'elaborato presenta la progettazione e la realizzazione di un Sistema di Visione Artificiale utilizzato per il controllo qualitativo.
Inizialmente viene descritto il problema da risolvere, illustrando il contesto industriale e i difetti da individuare.
Successivamente, il Sistema viene delineato in ogni sua parte: dai componenti fisici utilizzati agli algoritmi di Visione Artificiale implementati.
Infine sono presentati i risultati ottenuti. Questi sono stati presentati al cliente finale e giudicati efficienti rispetto al problema da risolvere.
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Mück, Isabel Magdalena [Verfasser], and Katja [Akademischer Betreuer] Heubel. "The role of an environmental gradient in driving population divergence in common gobies (Pomatoschistus microps) / Isabel Magdalena Mück ; Betreuer: Katja Heubel." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1198122129/34.
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Mück, Isabel [Verfasser], and Katja [Akademischer Betreuer] Heubel. "The role of an environmental gradient in driving population divergence in common gobies (Pomatoschistus microps) / Isabel Magdalena Mück ; Betreuer: Katja Heubel." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1198122129/34.
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Dotto, Federica. "Analisi del ciclo di vita della coltivazione di Phaeodactylum tricornutum: valutazione di scenari alternativi nell'approvvigionamento di CO2." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14637/.
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In questa tesi, che si inserisce nell’ambito del progetto regionale GoBioM, è stata applicata la metodologia Life Cycle Assessment (LCA) per quantificare gli impatti ambientali associati al processo di coltivazione di una specie microalgale, Phaeodactylum tricornutum, finalizzato alla produzione di composti bioattivi.
Si confrontano due scenari che differiscono per la tipologia di CO2 impiegata per insufflare le colture algali: nel primo viene utilizzata CO2 commerciale, nel secondo CO2 di scarto proveniente da un processo di upgrading del biogas a biometano. Lo scopo è stabilire se la produzione di biomassa algale, sfruttando CO2 di scarto, sia sostenibile e vantaggiosa dal punto di vista ambientale. Per la LCA è stato utilizzato il software GaBi 8.0. Inoltre, è stata condotta un’analisi di sensitività per valutare l’influenza dei seguenti parametri sui risultati finali: produttività algale, quantità di ipoclorito di sodio utilizzato per la sanificazione, percentuale di ricircolo del terreno di coltura e fonte di energia elettrica.
Dai risultati è emerso che le fasi più impattanti sono la coltivazione e la liofilizzazione della biomassa, e i maggiori contributi sono dovuti ai processi di produzione di energia elettrica, solventi di lavaggio e nutrienti per il terreno di coltura. Dall’analisi comparativa si vede che l’utilizzo di CO2 di scarto, in alternativa a quella sintetica, comporta una diminuzione degli impatti del 10-15%. Tale riduzione è dovuta proprio all’utilizzo di un flusso di CO2 biogenica che solitamente viene rilasciato in atmosfera, infatti vengono contemporaneamente evitati il processo di produzione di CO2 sintetica e la sua emissione in atmosfera. L’analisi di sensitività ha evidenziato che con opportuni accorgimenti è possibile ridurre gli impatti connessi a tale sistema produttivo del 60-70%: riduzione del quantitativo di solventi di lavaggio, impostazione di un ricircolo completo e utilizzo di una quota di energia da fonte fotovoltaica.
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Angelicola, Luana. "Ricostruzione cartografica delle localita Nemegt e Khulsan (deserto del Gobi, Omnogovi, Mongolia)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14038/.
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Il bacino del Nemegt (Mongolia) ed in particolare le località Khulsan e Nemegt hanno acquisito una notevole importanza da quando, in seguito alla prima spedizione organizzata dalla Russian Academy of Sciences nel 1946, furono organizzate numerose campagne che hanno documentato la presenza di unità tra le più ricche al mondo in fossili di dinosauro.
Allo stesso tempo, la scarsa disponibilità di dati cartografici dettagliati, ha limitato la nostra conoscenza sulle correlazioni stratigrafiche tra le diverse località e sulla corretta posizione stratigrafica dei siti di scavo.
Le uniche mappe disponibili fino ad oggi sono state disegnate a mano con il metodo della triangolazione utilizzando dei punti di controllo (cairn) costruiti sul terreno con piramidi di pietre.
Nel 2016 è stata organizzata una nuova spedizione per la realizzazione di mappe topografiche ad elevata risoluzione basate su immagini acquisite da drone.
Sono state investigate interamente le località Khulsan e Nemegt e parzialmente anche Altan Uul III e Tsagaan Khushuu.
I cairn utilizzati in passato per la realizzazione delle carte sono stati rimappati con il GPS e tramite l’elaborazione fotogrammetrica delle immagini abbiamo ottenuto il modello digitale del terreno e un’ortofoto per ogni località.
In questa tesi vengono presentate le nuove mappe topografiche delle quattro zone e la cartografia geologica delle località Khulsan e Nemegt realizzata integrando dati di letteratura, fotointerpretazione, analisi spettrale e d’immagine.
Le nuove informazioni topografiche e geologiche portano ad una stima dello spessore dell’intera successione affiorante di 225 m di cui circa 120 m di Fm. Baruungoyot, 25 m di Interfingering e 80 di Fm. Nemegt.
I dati presentati in questo studio costituiscono un sistema informativo completo in cui poter consultare dati topografici, geologici e paleontologici dettagliati così da implementare la nostra comprensione della zona e programmare le future spedizioni.
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Souza, Maria Fernanda da Silva. "Proteases alcalinas e manejo alimentar na larvicultura do neon gobi (Elacatinus figaro)." Florianópolis, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/96367.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em AquiculturaMade available in DSpace on 2012-10-26T11:21:01Z (GMT). No. of bitstreams: 1 310699.pdf: 687228 bytes, checksum: cea9efafb267becf4f9e4d912105b6b7 (MD5)
Endêmico da costa brasileira, o neon gobi (Elacatinus figaro) é um peixe que apresenta interesse para a o mercado ornamental pelo seu pequeno tamanho e fácil adaptação em cativeiro. Devido à captura excessiva, encontra-se inserido na lista de espécies ameaçadas de extinção. Com intuito de incrementar a produção intensiva do neon gobi, e compreender melhor os aspectos nutricionais, o presente estudo buscou compreender o potencial digestório da espécie através da determinação das proteases alcalinas totais. A atividade enzimática foi medida em peixes com 3, 22, 41 e 180 DAE, através da hidrólise da azocaseína. As proteases alcalinas da Artemia e rotífero foram determinadas para avaliar possíveis contribuições de enzima exógenas. Além disso, o protocolo alimentar comumente utilizado na larvicultura da espécie foi modificado, realizando-se um novo protocolo antecipando-se a oferta de Artemia em 6 dias em relação ao protocolo alimentar comumente usado, onde a atividade enzimática, o crescimento e a metamorfose das larvas foram avaliados em ambos os protocolos. A atividade das proteases alcalinas foi estatisticamente semelhante nos três estágios (3,22 e 41 DAE) da espécie, com um aumento evidente apenas na fase adulta (180 DAE). A contribuição de proteases alcalinas exógena no trato digestório do neon gobi foi de 2% do rotífero e 67,9 % da Artemia. A antecipação do fornecimento da Artemia demonstrou incrementar o crescimento e antecipar a metamorfose das larvas, porém a atividade enzimática das proteases alcalinas foi menor nesse protocolo do que o comumente utilizado, demonstrando-se benéfica do ponto de vista produtivo uma vez que alcançou o tamanho comercial mais cedo, e permaneceu menos tempo dependente da alimentação com a Artemia, o que reduz os custos de produção
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Eugênio, Renata Maria De Camargo. "Efeito da triiodotironina (T3) no desenvolvimento larval do neon gobi Elacatinus figaro." reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/156753.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2015.Made available in DSpace on 2015-12-01T03:14:04Z (GMT). No. of bitstreams: 1 336201.pdf: 764790 bytes, checksum: 7bbedae875f3bab7285713ad1b96cd2d (MD5) Previous issue date: 2015
O neon gobi Elacatinus figaro é um peixe endêmico do Brasil com grande importância no mercado da aquariofilia. Um dos gargalos para o seu cultivo é o estágio inicial de desenvolvimento larval caracterizado por elevada mortalidade, tanto na primeira semana após a eclosão como também no período que antecede a metamorfose. O experimento avaliou o efeito do hormônio triiodotironina (T3) na larvicultura do neon gobi em relação a taxa de sobrevivência, ao crescimento e a metamorfose larval. Larvas com 14DAE foram imersas em 3 doses de T3: TC (controle) - 0; T01 - 0,01; T025 - 0,025 e T05 - 0,05 mg/L. Uma réplica adicional de cada tratamento foi realizada para análise histológica dos folículos tireoidianos em larvas com 24DAE. As taxas de sobrevivência em TC, T01, T025 e T05 foram de 24, 54, 36 e 37%, respectivamente, sem diferença estatística entre os tratamentos (P>0,05). Quanto ao crescimento, os maiores comprimentos foram encontrados no TC. Nos T025 e T05, a metamorfose foi antecipada em até 11 dias em relação ao TC e T01. Em larvas do T01, os folículos eram numerosos com a presença de vesículas de reabsorção na periferia dos coloides, indicando aumento da produção de hormônios da tireoide (HTs), associado ao processo de metamorfose larval. Já no T05, foi observada a diminuição dos folículos em número e tamanho, caracterizando o fim da metamorfose. A utilização das doses de 0,025 e 0,05mg/L de T3 antecipou a metamorfose do neon gobi, refletindo na diminuição do tempo de larvicultura dessa espécie.
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Glover, Alicia Marie. "An Internship in Conservation Biology with Craighead Beringia South." Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1283544664.
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Gertzen, Svenja [Verfasser], and Jost [Gutachter] Borcherding. "The ecological niche of invasive gobies at the Lower Rhine in intra- and interspecific competitive and predatory nteractions / Svenja Gertzen ; Gutachter: Jost Borcherding." Köln : Universitäts- und Stadtbibliothek Köln, 2016. http://d-nb.info/1115330543/34.
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Pampoulie, Christophe. "Conséquences d'une arrivée massive d'eau douce sur la communauté de gobies (Téléostéens, Poissons) d'une lagune méditerranéenne : l'exemple de l'étang du Vaccarès (Camargue, France)." Montpellier 2, 1999. http://www.theses.fr/1999MON20148.
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Nous avons etudie l'effet d'une arrivee massive d'eau douce sur une communaute de gobies, constituee de gobius niger, pomatoschistus minutus et p. Microps, d'une lagune saumatre mediterraneenne, l'etang du vaccares. Trois points principaux ont ete abordes : - l'effet de cet evenement sur les parametres du milieu. Nos resultats montrent des modifications de nombreux parametres physico-chimiques dont certaines se sont maintenues durant notre suivi. Nous discutons des effets possibles directs et indirects de ces modifications sur le peuplement de poissons. - l'effet de cet evenement sur la communaute de gobies. Nous montrons la modification de la composition specifique de cette communaute, et discutons des parametres responsables de la disparition de g. Niger, des variations de captures de p. Minutus et de l'augmentation de celles de p. Microps. Les modifications observees dans la structure du peuplement et dans la croissance de p. Microps sont expliquees par un changement de sa strategie de reproduction. - l'effet de cet evenement sur les traits d'histoire de vie des trois especes. Nous montrons que p. Microps investit plus d'energie dans la reproduction apres les inondations, et ce malgre la presence d'un parasite intraclomique dont les effets sur la survie et l'effort reproducteur sont importants. Nous discutons egalement des differences observees dans les reactions de ces trois especes, et tentons de les expliquer par les differences de strategies et par leur tolerance aux variations des parametres environnementaux.
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Aude, Michelet. "No longer 'kings' : learning to be a Mongolian person in the middle Gobi." Thesis, London School of Economics and Political Science (University of London), 2013. http://etheses.lse.ac.uk/766/.
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This doctoral dissertation examines the inter-subjective processes through which young children are shaped and shape others into persons (hün), as they learn to interact through the Mongolian mode of hierarchical relations. Based on twenty months of ethnographic fieldwork in the middle Gobi, the research focuses on the period when children (between two and eight years of age) lose their status as indulged and protected babies and learn to assume the role of older brother/sister (ah/egj) and younger sibling (düü). To investigate how children become competent at interacting through the Mongolian mode of hierarchical relations, the study considers three questions: how do children learn to enact etiquette (yos)? How do children develop relations within and outside of their family (ger bül) and family network (ah düü)? How do children learn to work and to become helpful? The research reveals that Mongolian social hierarchy is structurally produced by, and is the product of, an irreconcilable moral tension. On the one hand, children learn to form relations of interdependence and to actively take part in the production of asymmetrical but mutual obligations. On the other hand, children learn to use etiquette to establish relations at the safe distance of respect, and to develop social and emotional skills to protect themselves from the potential dangers of relatedness. By documenting the processes through which children learn to form relations as ah/egj and düü, this study uncovers the social mechanisms which sustain the re-production of Mongolian social hierarchy and the individual skills necessary to be a socially and morally competent Mongolian person. More generally, the dissertation contributes to the anthropological study of personhood by rethinking ‘the cultural construction of the person’ as an ongoing process of learning.
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Thomas, Carole. "Etude du "bichique" à La Réunion : du recrutement d'une espèce amphidrome à l'éco-socio-système." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066303/document.
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Les enjeux liés à la conservation des gobies amphidromes à La Réunion, sont de nature écologique mais également socio-économique. Les deux espèces concernées, Sicyopterus lagocephalus et Cotylopus acutipinnis contribuent fortement à la diversité faunistique des rivières, en plus d’être la cible d’une pêche traditionnelle à forte valeur économique et patrimoniale. La pêche des « bichiques » fait localement référence aux deux espèces que l’on capture à l’état de post-larve lorsqu’elles entament leur recrutement dans les rivières. Dans un contexte où l’affaiblissement du recrutement larvaire est manifeste, cette thèse s’attache à décrire les enjeux qui gravitent autour de cette ressource, à travers l’étude de la variabilité du recrutement et de ses répercussions sur le socio-écosystème. Les résultats s’appuient sur la collecte de données écologiques et la réalisation d’une enquête auprès des acteurs de la pêche, entre octobre 2014 et février 2016. L’étude de la variabilité spatio-temporelle des traits d’histoire de vie des post-larves au recrutement révèle que les rivières de l’est, pourraient être des « secteurs sources » essentiels au maintien des populations de Gobbidae. L’analyse des entretiens révèle que la pêche depuis qu’elle s’est organisée en filière informelle, a fortement contribué à l’affaiblissement du recrutement et s’enlise désormais dans des conflits pour le partage de l’eau et de la ressource, au détriment de l’environnement et des pratiques traditionnelles. Les services de l’Etat qui ont entamé une démarche de régularisation de l’activité depuis 2012, sont dans un processus de coopération avec les pêcheurs qui se voit menacé par le braconnage. L’analyse croisée des connaissances acquises dans les deux volets de cette thèse, nous a permis de schématiser le socio-écosystème dans lequel s’insère le bichique et de communiquer sur le besoin de gérer les diverses pressions anthropiques à l’échelle des bassins versants, afin de préserver la fourniture durable de services écosystémiques dont dépend l’HommeThe issues related to the conservation of amphidromous gobies in Reunion Island are ecological but also socio-economic. The two species concerned, Sicyopterus lagocephalus and Cotylopus acutipinnis, contribute greatly to the faunistic diversity of the rivers, in addition to being the target of a traditional fishery of high economic and patrimonial value. The "bichic" fishery locally refers to the two species that are caught at the post-larva stage when they start recruiting in the rivers. In a context where the decline in larval recruitment is evident, this thesis attempts to describe the issues surrounding this resource through the study of recruitment variability and its impact on the socio-ecosystem. The results are based on the collection of ecological data and the completion of a survey of fishery stakeholders between October 2014 and February 2016. The study of the spatial and temporal variability of post-larval life history traits at recruitment reveals that the eastern rivers could be "source sectors" essential to the conservation of Gobbidae populations. The analysis of the interviews reveals that the fishery since it was organized in the informal sector has contributed strongly to the weakening of recruitment and is now stuck in conflicts for the sharing of water and resources, to the detriment of the environment and traditional practices. The State services, which have initiated a process to regularize the activity since 2012, are in a process of cooperation with fishermen who are threatened by poaching. The cross-analysis of the knowledge acquired in the two parts of this thesis allowed us to outline the socio-ecosystem in which the bichic is inserted and to communicate the need to manage the various anthropogenic pressures at the watershed scale, in order to preserve the sustainable supply of ecosystem services on which man depends