Shape analysis for 3D segmentation of cerebral structures with level sets and fuzzy control

http://www.afrif.asso.fr/archive/rfia2006/index.htmlNous nous proposons de segmenter des structures 3D avec des ensembles de niveau dont l'évolution est guidée par un modèle de forme et gérée par commande oue. Pour cela, plusieurs contours évoluent simultanément en direction de cibles anatomiques dénies au préalable. Un système de décision oue combine l'information a priori fournie par un modèle de forme, utilisé comme atlas, avec la distribution d'intensité de l'image et les positions relatives des contours. Il donne en sortie le terme de direction de l'équation d'évolution de l'ensemble de niveau associé à chaque contour. Cela entraîne une expansion ou une contraction locale des contours, qui convergent nalement vers leurs cibles respectives. Le modèle de forme est construit par analyse en composantes principales. La forme moyenne et les variations obtenues permettent alors de localiser une cible et de déterminer les états ous caractérisant la distance du contour courant à cette cible. Cette méthode est appliquée à la segmentation des noyaux gris du cerveau et évaluée quantitativement sur une base de 18 sujets

Behavioural inventory of the giraffe (<i>Giraffa camelopardalis</i>)

Background Numerous factors like continuous habitat reduction or fragmentation for free-ranging giraffes (Giraffa camelopardalis) as well as e.g. suboptimal housing conditions for animals in captivity might lead to behavioural alterations as part of the overall adaptation process to the changing living conditions. In order to facilitate current and future studies on giraffe behaviour, a comprehensive ethogram was compiled based on existing literature, as well as observations on giraffes in the wild (Hwange National Park, Zimbabwe; Entabeni Game Reserve, South Africa), and in captivity (National Zoological Gardens of South Africa, Pretoria). Findings The resulting ethogram lists 65 different behavioural patterns, which were described and grouped into seven categories: General activities, Abnormal repetitive behaviours, General interactions, Bull-Cow behaviour, Bull-Bull behaviour, Cow-Bull behaviour, Maternal behaviours, and Interactions by calves. The behaviours were further described regarding a presumed purpose, particularly with respect to social interactions and sexual behaviour. Contradictory descriptions from previous studies were considered and discussed in comparison with our own observations. Conclusions This ethogram provides a basis for current and future studies by suggesting a terminology which can be used for harmonizing behavioural observations, thus helping to facilitate comparability of future results. Subsequently, a better understanding of the behavioural ecology of giraffes in the wild as well as in captivity could aid future conservation efforts

Les girafes du Niger, dernières girafes d'Afrique de l'ouest

The giraffes of Niger are the last West African giraffes. This last remaining population, reduced to less than 100 individuals, is found in the Koure area and the northern part of the Dallol Bosso, one hundred kilometres East of Niamey. These giraffes live peacefully with humans and cattle, in a non-protected area, without predators. They are threatened by the clearing of their habitat and by poaching. Over the course of the year 1996, more than 30 % of the individuals disappeared, largely due to the numerous captures ordered by the government of Niger. At the end of 1996, a land use management project based on the giraffes'conservation was implemented in their living area. This project made possible the protection and reconstitution of the giraffe population. The balanced sex-ratio and significant birth-rate gives the present population a very good grounding for expansion provided that adequate protection and valorization policies are maintained. Heightened public awareness of the population in general and the political leaders of Niger in particular, is also an important factor. The expansion of this population will be possible only within the framework of an economic development program based on the conservation and valorization of natural resources, on the one hand, and on the management of these resources by local rural communities on the other hand. This article introduces the history of the giraffes'presence in West Africa and the recent demographic evolution of the population of giraffes in NigerLes girafes du Niger sont les dernières girafes d'Afrique de l'Ouest. Elles constituent une petite population de moins d'une centaine d'individus, située dans la région de Kouré et du Dallol Bosso Nord, à cent kilomètres à l'est de Niamey. Ces girafes vivent en milieu naturel non protégé, côtoyant pacifiquement les paysans et les animaux domestiques, en l'absence de tout prédateur. Elles sont menacées par la dégradation de leur habitat et par le braconnage. Au cours de l'année 1996, plus de 30 % des individus ont disparu, notamment en raison de captures massives par l'armée sur ordre du gouvernement, L'implantation, dans leur zone d'habitat, en 1996, d'un projet de développement axé sur leur conservation, a permis la protection et la reconstitution de la population. Celle-ci présente un sex-ratio équilibré et une natalité importante qui laisse espérer son développement si de bonnes conditions de protection et de valorisation sont réunies, ainsi qu'une sensibilisation de la population nigérienne et des responsables politiques. tJne telle situation ne sera possible que dans la perspective d'un développement économique qui s'appuiera sur la conservation et la valorisation des ressources naturelles d'une part, sur la gestion de ces ressources par les communautés rurales concernées d'autre part. Cet article présente l'historique de la présence des girafes en Afrique de l'Ouest et l'évolution démographique récente de la population de girafes du Niger

The last West African giraffes: insured survival or threatened future ?

The present paper describes the current situation of the giraffes of Niger. While the giraffe population there has increased from an estimated 49 in 1996 to more than 200 today, they remain extremely vulnerable. As a matter of fact, the abandonment of the local development initiative, begun in 1996, had adversely affected the area inhabited by giraffes from both an ecological and social point of view. This is because the rural population has ceased to be involved in the management of the natural resource base, resulting in the abandonment of conservation practices as witnessed by the establishment of some 10 local firewood markets in the region. The presence of these markets, in addition to clearing for cultivation of land, contributes to the large and irreversible destruction of the bush habitat and pasture used by the giraffes in the rainy season. A second consequence of the failure of the local development initiative is an increasing dependence on outside donors that have a presence in the region. This situation seriously compromises sustainable development in the region of Koure and of Dallol Bosso Nord and threatens the survival of the last remaining giraffes in West AfricaCet article décrit la situation actuelle des girafes du Niger. Si la population, estimée à 49 individus en septembre 1996, en compte actuellement plus de 200, elle reste néanmoins extrêmement vulnérable. En effet, l'abandon de la démarche de développement local, initiée en 1996, a entraîné de graves répercussions au niveau de la zone girafes, tant sur le plan écologique que sur le plan social. L'absence d'implication de la population rurale dans la gestion des ressources naturelles de son terroir a eu pour première conséquence son désengagement par rapport à leur conservation, ce qui a notamment favorisé l'implantation dans la région d'une dizaine de marchés de bois. Ces derniers contribuent, avec le défrichement lié aux cultures, à la destruction massive et irréversible de la brousse tigrée, habitat et pâturage de saison des pluies des girafes. Une deuxième conséquence réside dans l'établissement d'une relation de dépendance vis-à-vis des donateurs présents dans la région. Cette situation compromet gravement tant le développement durable de la région de Koure et du Dallol Bosso Nord que la survie des dernières girafes d'Afrique de l'Ouest

Sains Permakanan: Makanan Berfungsi

Kebanyakan pakar farmakologi mengakui bahawa permakanan penting unluk kesihatan dan kesejahteraan. Pada tahun 500 sebelum masihi, hubungan antara farmakologi dengan pemakanan adalah rapat sebagaimana yang dinyatakan oleh Hippocrates, 'Biarkan makanan menjadi ubat anda dan biarkan ubat meniadi makanan anda. Hanya rawatan semulajadi yang memenuhi kritera tersebut.' Orang Yunan kuno membahagikan perubatan kepada tiga kategori, atau diet, farmasi dan perubatan surgeri. Hal ini menunjukkan bahawa adalah makanan sebahagian daripada perubatan yang diamalkan. Dalam sistem perubatan tradisional seperti Ayurveda dan perubatan tradisional Cina, juga tidak ada perbezaan antara makanan dengan ubalan ialtu rnakanan adalah bahagan yang penting untuk mencegah penyakit dan menjaga kesihatan

Learning to Segment Microscopy Images with Lazy Labels

The need for labour intensive pixel-wise annotation is a major limitation of many fully supervised learning methods for segmenting bioimages that can contain numerous object instances with thin separations. In this paper, we introduce a deep convolutional neural network for microscopy image segmentation. Annotation issues are circumvented by letting the network being trainable on coarse labels combined with only a very small number of images with pixel-wise annotations. We call this new labelling strategy `lazy' labels. Image segmentation is stratified into three connected tasks: rough inner region detection, object separation and pixel-wise segmentation. These tasks are learned in an end-to-end multi-task learning framework. The method is demonstrated on two microscopy datasets, where we show that the model gives accurate segmentation results even if exact boundary labels are missing for a majority of annotated data. It brings more flexibility and efficiency for training deep neural networks that are data hungry and is applicable to biomedical images with poor contrast at the object boundaries or with diverse textures and repeated patterns

Assessing tumour vascularity with 3D contrast-enhanced ultrasound: A new semi-automated segmentation framework

International audience3D contrast-enhanced ultrasound (CEUS) is a powerful imaging technique for tumour vascularity assessment, which is critical for radio-frequency ablation (RFA) planning or for the assessment of response to antiangiogenic therapies. In this paper, we propose a novel semi-automated method for the quantification of tumour vascularity in 3D CEUS data. We apply a two-step framework combining an interactive segmentation of the tumour necrosis followed by an automatic detection of the vascularity based on implicit representations. Experimental results on 3D CEUS images of renal cell carcinomas (RCC) show that our method is promising in terms of speed and quality. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

Extensive population genetic structure in the giraffe

<p>Abstract</p> <p>Background</p> <p>A central question in the evolutionary diversification of large, widespread, mobile mammals is how substantial differentiation can arise, particularly in the absence of topographic or habitat barriers to dispersal. All extant giraffes (<it>Giraffa camelopardalis</it>) are currently considered to represent a single species classified into multiple subspecies. However, geographic variation in traits such as pelage pattern is clearly evident across the range in sub-Saharan Africa and abrupt transition zones between different pelage types are typically not associated with extrinsic barriers to gene flow, suggesting reproductive isolation.</p> <p>Results</p> <p>By analyzing mitochondrial DNA sequences and nuclear microsatellite loci, we show that there are at least six genealogically distinct lineages of giraffe in Africa, with little evidence of interbreeding between them. Some of these lineages appear to be maintained in the absence of contemporary barriers to gene flow, possibly by differences in reproductive timing or pelage-based assortative mating, suggesting that populations usually recognized as subspecies have a long history of reproductive isolation. Further, five of the six putative lineages also contain genetically discrete populations, yielding at least 11 genetically distinct populations.</p> <p>Conclusion</p> <p>Such extreme genetic subdivision within a large vertebrate with high dispersal capabilities is unprecedented and exceeds that of any other large African mammal. Our results have significant implications for giraffe conservation, and imply separate <it>in situ </it>and <it>ex situ </it>management, not only of pelage morphs, but also of local populations.</p

The mammals of Angola

Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio