Scale is a widely used notion in medical image analysis that evolved in the form of scale-space theory where the key idea is to represent and analyze an image at various resolutions. Recently, a notion of local morphometric scale referred to as "tensor scale" was introduced using an ellipsoidal model that yields a unified representation of structure size, orientation and anisotropy. In the previous work, tensor scale was described using a 2-D algorithmic approach and a precise analytic definition was missing. Also, with previous framework, 3-D application is not practical due to computational complexity. The overall aim of the Ph.D. research is to establish an analytic definition of tensor scale in n-dimensional (n-D) images, to develop an efficient computational solution for 2- and 3-D images and to investigate its role in various medical imaging applications including image interpolation, filtering, and segmentation. Firstly, an analytic definition of tensor scale for n-D images consisting of objects formed by pseudo-Riemannian partitioning manifolds has been formulated. Tensor scale captures contextual structural information which is useful in local structure-adaptive anisotropic parameter control and local structure description for object/image matching. Therefore, it is helpful in a wide range of medical imaging algorithms and applications. Secondly, an efficient computational solution of tensor scale for 2- and 3-D images has been developed. The algorithm has combined Euclidean distance transform and several novel differential geometric approaches. The accuracy of the algorithm has been verified on both geometric phantoms and real images compared to the theoretical results generated using brute-force method. Also, a matrix representation has been derived facilitating several operations including tensor field smoothing to capture larger contextual knowledge. Thirdly, an inter-slice interpolation algorithm using 2-D tensor scale information of adjacent slices has been developed to determine the interpolation line at each image location in a gray level image. Experimental results have established the superiority of the tensor scale based interpolation method as compared to existing interpolation algorithms. Fourthly, an anisotropic diffusion filtering algorithm based on tensor scale has been developed. The method made use of tensor scale to design the conductance function for diffusion process so that along structure diffusion is encouraged and boundary sharpness is preserved. The performance has been tested on phantoms and medical images at various noise levels and the results were quantitatively compared with conventional gradient and structure tensor based algorithms. The experimental results formed are quite encouraging. Also, a tensor scale based n-linear interpolation method has been developed where the weights of neighbors were locally tuned based on local structure size and orientation. The method has been applied on several phantom and real images and the performance has been evaluated in comparison with standard linear interpolation and windowed Sinc interpolation methods. Experimental results have shown that the method helps to generate more precise structure boundaries without causing ringing artifacts. Finally, a new anisotropic constrained region growing method locally controlled by tensor scale has been developed for vessel segmentation that encourages axial region growing while arresting cross-structure leaking. The method has been successfully applied on several non-contrast pulmonary CT images. The accuracy of the new method has been evaluated using manually selection and the results found are very promising.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13372号 / 論医博第2209号 / 新制||医||1047(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 花川 隆, 教授 髙橋 良輔, 教授 小柳 義夫 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23102号 / 医博第4729号 / 新制||医||1050(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 花川 隆, 教授 髙橋 良輔, 教授 伊佐 正 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

<p>Pored rodova evropskih orhideja koji se odlikuju velikim stepenom diverzifikacije, kao i značajnim brojem novoopisanih vrsta, kao &scaron;to su <em>Ophrys </em>ili<em> Epipactis,</em> rod<em> Anacamptis </em>je ostao poprilično zapostavljen u orhidolo&scaron;kim istraživanjima. Na predstavnicima ovog roda uglavnom su vr&scaron;ena molekularna istraživanja, u kojima je bio uključen i veći broj drugih rodova.Takođe, urađene su i opsežne studije, ali samo na pojedinim vrstama. Morfolo&scaron;ka istraživanja su bila veoma retka i uz par uzuzetaka, ograničena na geografski mala područja i na jednu ili nekoliko morfolo&scaron;ki sličnih vrsta. Analiza morfolo&scaron;ke varijabilnosti ovolikog broja taksona roda<em> Anacamptis</em> na geografski relativno velikom području kakvo je Balkansko poluostrvo, kao i deo Panonske nizije koji se oslanja na njega, do&nbsp; sada nije bilo sprovedeno. Morfolo&scaron;kim analizama bili su podvrgnuti gotovo svi predstavnici ovog roda u rangu vrste i podvrste, a koji se javljaju na području kopnenog dela Balkanskog poluostrva, kao i južnog oboda Panonske nizije. Sprovedene su jednostrane i uporedne morfolo&scaron;ke analize sa detaljnomobradom podataka metodama bazične, univarijantne i multivarijantne statistike. Do sada najvećim istraživanjem taksona roda<em> Anacamptis</em>, po broju obrađenih jedinki i području na kom je sprovedeno, bila je obuhvaćena 2001 jedinka iz 185&nbsp; populacija. Analizirane su prirodne populacije, ali i materijal iz Herbarijuma BUNS. Ukupno je definisano 69 morfolo&scaron;kih karaktera, kvantitativnih i kvalitativnih, a među njima su traženi oni koji imaju potencijalno diferencijalni karakter između opisanih vrsta i infraspecijskih taksona. Analize su obuhvatile i interpopulacionu morfolo&scaron;ku varijabilnost u okviru svakog taksona, a u cilju uočavanja postojanja određenih geografskih obrazaca njenih promena. Morfolo&scaron;ki karakteri koji su se u sprovedenim analizama pokazali kao taksonomski informativni, iskori&scaron;ćeni su za formiranje dihotomog ključa za determinaciju taksona roda <em>Anacamptis</em> prisutnih na istraživanom području. Analizama je utvrđen veliki broj karaktera koji su statistički značajno različiti između analiziranih populacija, podvrsta i vrsta. Većina karaktera je pokazala umerenu ili nisku varijabilnost, a u retkim slučajevima i povećanu. Karakteri cveta međusobno su statistički značajno korelisani,većina slabo do umereno, dok su oni na listićima kacige, kao i između labeluma i drugih delova cveta jako do izrazito jako povezani. Jedini takson koji nije pokazao nikakvu infraspecijsku diferencijaciju, a koji se odlikuje velikom unutari interpopulacionom varijabilno&scaron;ću je<em> A. pyramidalis</em>. Iz istog razloga je pokazano kao neosnovano izdvajanje jedinki iz različitih delova njegovog areala u do sada opisane infraspecijske oblike. Potvrđena je niska morfolo&scaron;ka varijabilnost uskorasprostranjene vrste <em>A. boryi.</em> Kod svih preostalih istraživanih taksona utvrđeno je postojanje određenih obrazaca geografske interpopulacione varijabilnosti i infraspecijske struktuiranosti.Populacije <em>A. laxiflora</em> subsp. <em>laxiflora </em>mogu se podeliti na jadranske i kontinentalne, pri čemu najzapadnije pokazuju i najmanje vrednosti analiziranih karaktera. <em>A. coriophora </em>subsp.<em> fragrans </em>se pokazala kao manje varijabilnom od tipske podvrste, ali je u okviru nje kao zaseban takson izdvojen var. <em>hermae </em>kao fenolo&scaron;ki, ekolo&scaron;ki i morfolo&scaron;ki odvojen u odnosu na ostaleispitivane populacije. Tipska podvrsta pokazuje obrazac variranja ukupne morfolo&scaron;ke varijabilnosti u pravcu zapad-istok. Kao karakteri koji su najznačajniji za diferencijaciju podvrsta vrste<em> A. palustris</em> izdvojeni su dužina i &scaron;irina brakteje, stepen diferenciranosti labeluma na režnjeve, kao i dubina sinusa koja ih razdvaja. Populacije<em> A. palustris</em> subsp. <em>elegans</em> moguće je podeliti na tri geografski i morfolo&scaron;ki definisane grupe &ndash; istočnobalkansku, zapadnobalkansku i periferne populacije sa severa Srbije i iz Slovenije. Kao diferencijalni karakteri između taksona sekcije <em>Laxiflorae</em> pokazali su se odnos između dužine plodnika i brakteje, kao i dužina srednjeg režnja labeluma. Vrsta<em> A. morio </em>je po prvi put jasno morfolo&scaron;ki i arealno podeljena na dve podvrste na istraživanom području. Podvrste pokazuju velika preklapanja vrednosti morfolo&scaron;kih karaktera, ali se obe odlikuju specifičnim karakteristikama cveta, pre svega labeluma na osnovu kojih ih je moguće razlikovati. Definisani su areali podvrsta<em> A.morio </em>na istraživanom području &ndash; tipska podvrsta je prevashodno severnija i zapadnija, dok je subsp.<em> caucasica </em>južnija i istočnija. Prvu odlikuju krupniji cvetovi, bubrežastih labeluma sa srednjim režnjem koji ne prevazilazi značajno dužinu bočnih, dok je druga sa sitnijim cvetovima i snažno isturenim srednjim režnjem. Obe podvrste mogu se podeliti na grupe populacija sa jasno definisanim geografskim raspostranjenjem. Vrsta <em>A. papilionacea </em>je po prvi put morfolo&scaron;ki istaživana na većem broju primeraka, a ne prostim poređenjem pojedinačnih primeraka iz različitih delova areala. Pokazana je morfolo&scaron;ka diferenciranost na dve podvrste &ndash; tipsku i subsp. aegaea, koje se jasno morfolo&scaron;ki razlikuju i zauzimaju različite delove areala vrste. U okviru subsp. <em>papilionacea</em> registrovan je klinalni raspored morfolo&scaron;ke varijabilnosti u pravcu sever-jug. Registrovana su i tri hibrida, nova za područje pojedinih zemalja &ndash; A. <em>&times; gennarii</em> (Severna Makedonija),A. <em>&times; parvifolia</em> (Crna Gora) i A. &times; <em>timbali</em> (Srbija). Hibridi pokazuju generalnu morfolo&scaron;ku intermedijarnost u odnosu na roditelje, ali se odlikuju i novim stanjima karaktera, nezabeleženim kod roditeljskih taksona. Slični obrasci morfolo&scaron;ke varijabilnosti, kako na interpopulacionom nivou pojedinih vrsta, ali iizmeđu podvrsta svake istraživane vrste, pokazuju jasnu vezu između istraživanih taksona i jo&scaron; jednom opravdavaju njihovo zajedničko grupisanje u rod<em> Anacamptis.</em></p> / <p>Unlike the highly diversified and species-rich genera of European orchids, such as<em> Ophrys </em>or <em>Epipac</em>tis, the genus <em>Anacamptis </em>has remained quite neglected in orchidological research. Representatives of this genus, together with many others genera, were investigated mainly by molecular methods. Also, extensive studies have been done, but only on specific species. Morphological studies were very rare, and with a few exceptions, limited to geographically small areas and one or more morphologically similar species. Analysis of the morphological variability of so many taxa of the genus <em>Anacamptis</em>, in a is, in a geographically relatively large area such as the Balkan Peninsula, as geographically relatively large area such as the Balkan Peninsula, as well as the southern part of the Pannonian Plain, has not been conducted so far. Morphological analyses were<br />performed on almost all representatives of this genus,in the species and subspecies rank , occurring in the Balkan Peninsula mainland, as well as in the southern perimeter of the Pannonian Plain. Comparativemorphological analyses were conducted using the methods of basic, univariate and multivariate statistics.So far, the largest study of the genus&nbsp; nacamptis, by the number of processed individuals and the area in which it was conducted, included 2001 individuals from 185 populations. Natural populations and&nbsp; material from the BUNS Herbarium were analyzed. A total of 69 morphological characters, quantitative and&nbsp; qualitative, were defined, and those that have a potentially differential character among analyzed species and infraspecific taxa were selected. The analyzes also included interpopulation morphological variability within each taxon, to identify the existence of specific geographic patterns of its changes. The morphological characters that proved to be taxonomically informative, were used to form the dichotomous key for the determination of the genus Anacamptis members, presented in the study area. The analyzes identified a large number of characters that were statistically significantly different between the analyzed populations, subspecies, and species. Most of the characters showed moderate or low variability, and in rare cases increased variability. Flower&rsquo;s characters were statistically significantly correlated with each other, most of them weakly to moderately, while those of the sepals and petals, as well as between the&nbsp; labellum and other parts of the flower, were very strongly correlated. The only taxon that has not shown any infraspecific differentiation (except <em>A. boryi</em>), and which is characterized by high intra- and interpopulation variability, is A. pyramidalis. For the same reason, it has been shown as unjustified to separate individuals from different parts of species range into infraspecific forms. The low morphological variability of the narrowly distributed A. boryi was confirmed. In all other taxa studied, the existence of certain patterns of geographical interpopulation variability and infraspecific structuring was detected. <em>A. laxiflora</em> subsp. <em>laxiflora</em> populations can be divided into two groups &ndash; Adriatic and Continental, with the lowest characters values measured among the westernmost populations. <em>A. coriophora s</em>ubsp. <em>fragrans</em> proved to be less variable than the type subspecies, but within it, a new variety (var. hermae) as phenological, ecological and morphologically distinct from other studied populations was described. The typesubspecies has a transition of morphological variability in a west-east direction. The characters that are the most important for differentiation of A. palustris subspecies are the&nbsp; bract length and width, the degree of labellum differentiation into lobes, and the depth of the sinuses that separate them. Populations of A. palustris subsp. elegan<em>s </em>can be divided into three geographically and morphologically defined groups &ndash; Eastern Balkan, Western Balkan and peripheral populations from the North Serbia and Slovenia. Differential characters&nbsp; among the Laxiflorae section taxa are ration between the ovary length and bract length, as well as the labellum middle lobe length. For the first time, species <em>A. morio </em>is morphologically and geographically divided into two subspecies, in the&nbsp; study area. Analyzed subspecies have great overlapping values for many morphological characters, but both are characterized by specific flower&rsquo;s characteristics, above all labellum shape. On this basis, it is possible to distinguish them. Areals of <em>A</em>. <em>morio </em>subspecies were defined &ndash; the type subspecies is predominantly northern and western,while subsp. caucasica is southern and eastern. The first is characterized by larger flowers, renal shape labellum with a median lobe that does not exceed significantly the length of the lateral ones, while the second subspecies has smaller flowers and strongly projecting the median lobe. Both subspecies can be divided into groups of populations that have clearly defined geographical distribution. For the first time, A. papilionacea was morphologically investigated on a larger number of specimens, unlike previous&nbsp;&nbsp; researches in which individual specimens from different parts of the range were simply compared. Morphological differentiation into two subspecies was shown &ndash; type and subsp. aegaea. They are morphologically distinct and occupy different parts of the species range. Within the subsp. papilionacea a clinal distribution of morphological variability in the north-south direction was recorded. Three taxa of hybrid origin, new for the area of North Macedonia (A.<em> &times; gennari</em>i), Montenegro (A. <em>&times; parvifolia</em>) and Serbia (A. &times; t<em>imbali</em>) were registered. Hybrids exhibit a general morphological intermediacy between parents but are also distinguished by new character states that were not observed in<br />parental taxa. Similar patterns of morphological variability, both at the interpopulation level ofindividual species and between the subspecies of each species studied, show a clear relationship between the studied taxa and once again justify their grouping into the genus <em>Anacamptis.</em></p>

This thesis deals with the ontogeny of trilobites and agnostids from the Cambrian of the Skryje-Týřovice and Příbram-Jince basins (Barrandian area, Bohemian Massif). Thesis is presented as a compilation of four papers that were published in scientific peer-reviewed journals. The introduction of the thesis serves as a general overview of the trilobite post- embryonic development and connects all published papers together. All four papers presented here are focussed on modern description of the post-embryonic development of Sao hirsuta, Ptychopariida sp. A, Ptychopariida sp. B, Ptychopariida sp. C, Ellipsocephalus hoffi, Ellipsocephalus polytomus, Hydrocephalus carens and Ecca- paradoxides pusillus. In addition, a discussion about the life-history strategies of early developmental trilobite stages is presented. It has been suggested that Sao hirsuta and Ptychopariida sp. A had benthic protaspides and that the early ontogenetic stages of Ptychopariida sp. B, Eccaparadoxides pusillus and Hydrocephalus carens were likely lecithortophic. Consequently, it has been documented that species with benthic protaspides show a strongly restricted geographic distribution and that lecithotrophic taxa seem to be associated with higher latitude areas. The developmental patterns of Ellipsocephalus hoffi and...

A spinal cord injury (SCI) is a damage to the spinal cord that causes permanent or temporary changes in motor and sensory functions. In humans, the traumatic impact to spinal cord is mostly directed from the ventral part of the spinal column, even though SCI models are principally directed from the dorsal part of the spinal column due to easier surgery. The aim of the work described in this thesis was to develop clinically more relevant, easily reproducible and relatively inexpensive model of the ventral spinal cord lesion in rats which replicates SCI in humans as closely as possible by its pathology, completeness, level and regeneration. For the surgery we used a modification of a balloon- compression technique. The balloon of the 2F embolectomy Fogarty's catheter was placed to the anterior epidural space via laminectomy at the level of T10 and when the final position of the catheter was achieved at the spinal level T8 in front of the anterior median fissure, a balloon was rapidly inflated with 10 μl or 15 μl of water for 5 minutes. Other two groups - laminectomy only and ventral placement of the catheter without inflation were used as controls. The motor functions were evaluated by the BBB test and ladder walking test. In BBB test we observed significantly impaired motor functions in the 15 μl...

Die Forschungsergebnisse der letzten Jahre beweisen, dass die Informationsverarbeitung im ZNS auf eine ausgewogene Interaktion zwischen den Neuronen und den Astrozyten im Sinne eines funktionellen Netzwerkes angewiesen ist. Allerdings liegen nur unzureichende Erkenntnisse über den strukturellen Charakter dieser symbiotischen Beziehung vor. Zu den grundlegenden Aufgaben der Astrozyten gehört die Modulation der synaptischen Aktivität von Neuronen, Aufrechterhaltung der extrazellulären Homoöstase, Ausbildung der Blut-Hirn-Schranke, Pufferung der lokalen Kaliumkonzentration und die Synthese von Zytokinen, Wachstumsfaktoren sowie Neurotransmittern. Ein Hauptbestandteil des Zytoskelettes der Astrozyten stellen die Intermediärfilamente (z.B. GFAP, Vimentin) dar. Funktionell dienen sie dem Aufbau von Zell-Zell- Kontakten, der Stabilisierung des Zytoskelettes und der Verankerung der Zellorganellen im Zytoplasma. Charakteristisch für den strukturellen Aufbau der Astrozyten ist das GFAP, welches hauptsächlich in den Zellfortsätzen lokalisiert ist. Aktuelle Forschungen legen nahe, dass es sowohl unter physiologischen Alterungsprozessen als auch im Rahmen von pathologischen Vorgängen im ZNS (beispielsweise chronischer Alkoholabusus, Alexanderkrankheit, Ischämien und Epilepsie) zu einem prozentualen Anstieg der GFAP-Expression kommt, wobei der Einfluss dieser erhöhten GFAP-Synthese auf die Funktionsfähigkeit der Astrozyten noch nicht umfassend geklärt werden konnte. Im Zentrum dieser Dissertation steht deshalb die Fragestellung, haben Alter und Intermediärfilamente (GFAP, Vimentin) Einfluss auf Morphologie und Zellzahl der Astrozyten im Hippokampus einer Maus? Initial erfolgte die Volumenbestimmung der Astrozytendomänen mittels LSM- Aufnahmen im Reflexionsmodus sowie Vermessung nach Bearbeitung der Präparate mit der Silber Imprägnationstechnik. Die Domäne eines Astrozyten stellt das von einem Astrozyten mit Soma und allen Fortsätzen okkupierte Volumen dar. Nach der Auswahl von S100ß als immunhistochemischen Astrozytenmarker wurde die Zellzählung in entsprechenden Hippokampusarealen durchgeführt. Aus den ermittelten Daten wurde rechnerisch der Überlappungsgrad der hippokampalen Astrozytendomänen bestimmt. Von entscheidendem Interesse war dabei die Möglichkeit einer Überschneidung benachbarter Astrozytendomänen. Aus den Messungen resultiert ein ca 1,6 fach grösseres Volumen der Wildtyp-Tiere im Vergleich zu den Doppel-knock-out-Mäusen. Im Gegensatz dazu zeigten die Ergebnisse der Zellzählung sowohl in der Kontrollgruppe als auch in der Gruppe der Versuchstiere eine vergleichbare Astrozytenanzahl pro mm3. Entsprechend lag der Überlappungsfaktor bei den Doppel-Knock-out-Tieren (0,49) unter dem der Wildtyp-Tiere (0,7). Die abschließende Auswertung erbrachte in allen Untersuchungsgruppen einen Überlappungsfaktor < 1. Ausgehend von der essentiellen Bedeutung der Astrozyten für die Funktionsfähigkeit der Nervenzellen käme es z.B. im Rahmen pathologischer Prozesse, welche mit Gliazellschäden einhergehen, bei einem Überlappungsfaktor < 1 zu erheblichen Engpässen in der neuronalen Versorgung, sowie in der Kompensation äußerer Einflüsse. Die Wahrscheinlichkeit irreversibler Schädigung der Nervenzellen steigt.

An Algerian Phacopid fauna, described by Lemaître in 1952, is reexamined here. Species arereevaluated in order to be in agreement with modern taxonomy. To characterize the size and shape of our specimens, as well as inter- and intraspecific variations, a morphometric analysis was performed. Only holaspids were analyzed. Results of our analysis show that genera can be be well differentiated thanks to quantitative methods. However, at a specific level, only Austerops lemaitrii nov. sp. is well- defined. Other species can be defined, however, thanks to quantitative methods. Shape variations during growth were also defined in order to understand the evolution of our specimens. Three species show a correlation between shape and size variations for cephala, and two species for the pygidia, which show an ontogenic control of the shape. A covariate analysis was made between the shape of the cephala and the shape of the pygidia, and all of the specimens analyzed show a covariance betweencephalic and pygidial shape. / Trilobiter utgjorde en viktig del av faunun under paleozoikum. I denna artikel studeras ochomprövas en trilobitpopulation från Algeriets devon. För att bättre förstå populationstillväxt och evolution görs analyser av storlek (biometrisk analys) och form (morfometrisk analys). Resultaten visar att de olika släktena är väldefinierade och att tillväxten av somliga arter påverkar formen.Analysen visar också på en samvariation mellan cephalons och pygidiums form.

Le climat primitif martien fascine la recherche martienne. Identifier avec le plus de précision possible les conditions primitives martiennes permettrait de contraindre les différents états de l’eau au cours de l’histoire martienne. Aujourd’hui deux hypothèses font débat, la première est celle d’un climat chaud et humide régnant à la surface de Mars à la fin du Noachien/début Héspérien. La deuxième, à l’inverse, semble indiquer que le climat aurait été froid et englacé sur les plus hautes altitudes martiennes. Néanmoins, cette deuxième hypothèse est souvent contestée, car contrairement à la présence de marqueur d’eau liquide à la surface de Mars, aucune morphologie de surface attestant d’un climat froid n’avait été identifiée. Au cours de cette thèse, nous avons étudié de manière morphométrique les structures et morphologies à la surface de Terra Sabaea, qui constitue 1% de la superficie totale de la planète. Ces structures constituent des héritages morphologiques des activités climatiques passées. Afin de caractériser au mieux l’origine érosive de ces structures, nous avons créé une nouvelle méthode d’analyse morphométrique à partir de différentes méthodes terrestres et martiennes. Cette nouvelle méthode permet d’extraire plus de 20 données exploitables par vallée. Il a donc été question de mesurer un maximum de vallée afin d’établir une base de données que nous avons comparée avec des bases de données de morphologies terrestres et martiennes. Grâce à cette analyse, il a été possible de mettre en évidence, la présence d’un paysage glaciaire dans la région de Terra Sabaea. Ce paysage est composé de (1) vallées glaciaires liées avec (2) des cirques glaciaires. La source de cette glace semble être (3) des calottes de plateaux locales à des altitudes > 3500 m. Nous avons donc démontré pour la première fois la présence de morphologies glaciaires attestant d’un climat froid il y a 3.6 Ga. Néanmoins, la présence de telles morphologies n’indique pas que l’ensemble de Terra Sabaea était englacé. L’analyse morphométrique a démontré la présence de morphologie fluviatile géographiquement proche des morphologies glaciaires et souvent à la même altitude, entre 1500 et 3500 m. Cette observation nous a permis de mettre en évidence (4) que la pente était un facteur qui influençait sur l’état de l’eau. En effet, pour une même altitude, les morphologies fluviatiles sont situées sur les pentes douces (< 3°) alors que les morphologies glaciaires sont situées sur les remparts internes des cratères d’impacts présentant une forte pente (> 10°). Cependant (5) l’altitude semble également être un facteur déterminant puisque l’on ne retrouve pas de morphologie glaciaire à des altitudes < 1500 m. L’analyse des terrains de Terra Sabaea a également mis en évidence (6) qu’il existait un lien génétique entre les morphologies glaciaires de hautes altitudes et les vallées fluviatiles plus bas. En effet, il est possible de suivre une vallée qui prend sa source sur les hauts plateaux englacés en amont, jusqu’en aval où elle rejoint des morphologies témoignant d’une activité fluviatile. Cette continuité dans les morphologies glaciaires et fluviatiles permet (7) de mieux définir l’origine des vallées ramifiées, et notamment l’origine de Naktong vallis, et il semblerait que la fonte des glaces a joué un rôle dans leurs formations. De plus, cette continuité morphologique permet de supposer qu’il existait (8) un cycle de l’eau similaire à la Terre dans la région de Terra Sabaea il y a 3.6 Ga. / The primitive Martian climate fascinates Martian research. Identifying Martian primitive conditions as accurately as possible would make it possible to constrain the different states of water during Martian history. Today two hypotheses are debated, the first is that of a hot and humid climate prevailing on the surface of Mars at the end of the Noachian / early Hesperian. The second, on the contrary, seems to indicate that the climate was cold and glacial on the highest Martian altitudes. Nevertheless, this second hypothesis is often disputed, because unlike the presence of liquid water marker on the surface of Mars, no surface morphology attesting to a cold climate had been identified. In this thesis, we studied morphometrically structures and morphologies on the surface of Terra Sabaea, which constitutes 1% of the total surface of the planet. These structures constitute morphological legacies of past climatic activities. In order to better characterize the erosive origin of these structures, we have created a new method of morphometric analysis from different terrestrial and Martian methods. This new method makes it possible to extract more than 20 exploitable data per valley. It was therefore a question of measuring a valley maximum in order to establish a database that we compared with databases of terrestrial and Martian morphologies. Thanks to this analysis, it has been possible to highlight the presence of an ice landscape in the Terra Sabaea region. This landscape is composed of (1) glacial valleys linked or not with (2) glacial cirques. The source of this ice appears to be (3) local plateau caps at altitudes> 3500 m. We thus demonstrated for the first time the presence of glacial morphologies attesting to a cold climate there are 3.6 Ga. Nevertheless, the presence of such morphologies does not indicate that the whole of Terra Sabaea was glaciated. Morphometric analysis has demonstrated the presence of fluvial morphology geographically close to glacial morphologies and often at the same altitude, between 1500 and 3500 m. This observation allowed us to highlight (4) that the slope was a factor influencing the state of the water. Indeed, for the same altitude, fluvial morphologies are located on gentle slopes (<3 °) while glacial morphologies are located on the inner walls of impact craters with a steep slope (> 10 °). However (5) altitude also seems to be a determining factor since we do not find glacial morphology at altitudes <1500 m. Terra Sabaea land analysis also revealed (6) that there is a genetic link between high altitude glacial morphologies and lower river valleys. Indeed, it is possible to follow a valley that has its source on the highlands glaciers upstream, downstream where it joins morphologies testifying to a fluviatile activity. This continuity in glacial and fluvial morphologies makes it possible (7) to better define the origin of branched valleys, and in particular the origin of Naktong vallis, and it seems that melting ice has played a role in their formations. Moreover, this morphological continuity makes it possible to suppose that there existed (8) a cycle of water similar to the Earth in the region of Terra Sabaea there is 3.6 Ga.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20803号 / 医博第4303号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 平井 豊博, 教授 今中 雄一, 教授 伊達 洋至 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM