117 research outputs found
Surpeuplement, fécondité, mortalité et agressivité dans une population captive de Papio papio
A social group of 60 western baboons Papio papio, established since 1939, was studied during a 20 month period (actual observa tion time : 450 hours) in the Parc Zoologique du Bois de Vincennes, Paris. The « home range » of the captive troop was 535 m2 and the population density reached 11 monkeys per 100 m2, i.e. 10,000 to 100,000 times higher than that of other savana baboons within their yearly home range in the wild. The ratio Males : Females within the group (infants excluded) was 1 : 2.1. Among adults alone, females were much more nume rous, ranging from 1 : 12.5 to 1 : 22. Yet, there were more male than female infants at birth, 1 : 0.30. The birth rate for adult female baboons was high. The average reproductive rate was of one infant per female every 382 days in 1970, and of one infant per female every 465 days in 1971. The crude death rate was 31 deaths in a total of 39,100 mon- key-days, or 7.93 X 10"4 deaths per monkey-day. Most deaths (20 out of 31) occurred at birth and during the first year of life. The number of agonistic interactions occurring among adults and subadults with sufficient intensity to provoke barking and roaring by males or screaming, screeching and squealing by females was counted, and divided by the total number of hours of observation : 1 agonistic interaction occured every 7.3 minutes. Serious fights involving biting were rare (9 % of the cases). Comparisons are made with various natural populations of savana baboons. Contrary to the situation in most rodent popula tions studied to date, prolonged crowding in baboons does not appear to decrease fertility. The increase of agonistic behaviour is moderate and the death rate remains much the same than in a wild population
Application du microscope électronique à balayage (MEB) à la paléontologie et à la sédimentologie
The intestinal expulsion of the roundworm Ascaris suum is associated with eosinophils, intra-epithelial T cells and decreased intestinal transit time
Ascaris lumbricoides remains the most common endoparasite in humans, yet there is still very little information available about the immunological principles of protection, especially those directed against larval stages. Due to the natural host-parasite relationship, pigs infected with A. suum make an excellent model to study the mechanisms of protection against this nematode. In pigs, a self-cure reaction eliminates most larvae from the small intestine between 14 and 21 days post infection. In this study, we investigated the mucosal immune response leading to the expulsion of A. suum and the contribution of the hepato-tracheal migration. Self-cure was independent of previous passage through the liver or lungs, as infection with lung stage larvae did not impair self-cure. When animals were infected with 14-day-old intestinal larvae, the larvae were being driven distally in the small intestine around 7 days post infection but by 18 days post infection they re-inhabited the proximal part of the small intestine, indicating that more developed larvae can counter the expulsion mechanism. Self-cure was consistently associated with eosinophilia and intra-epithelial T cells in the jejunum. Furthermore, we identified increased gut movement as a possible mechanism of self-cure as the small intestinal transit time was markedly decreased at the time of expulsion of the worms. Taken together, these results shed new light on the mechanisms of self-cure that occur during A. suum infections
Deep Neural Network Attribution Methods for Leakage Analysis and Symmetric Key Recovery
Deep Neural Networks (DNNs) have recently received significant attention
in the side-channel community due to their state-of-the-art
performance in security testing of embedded systems. However,
research on the subject mostly focused on techniques to improve the
attack efficiency in terms of the number of traces required to extract secret
parameters. What has not been investigated in detail is a constructive
approach of DNNs as a tool to evaluate and improve the effectiveness
of countermeasures against side-channel attacks. In this work, we try to
close this gap by applying attribution methods that aim for interpreting
DNN decisions, in order to identify leaking operations in cryptographic
implementations. In particular, we investigate three different approaches
that have been proposed for feature visualization in image classification
tasks and compare them regarding their suitability to reveal Points of
Interests (POIs) in side-channel traces. We show by experiments with
three separate data sets that Layer-wise Relevance Propagation (LRP)
proposed by Bach et al. provides the best result in most cases. Finally, we
demonstrate that attribution can also serve as a powerful side-channel
distinguisher in DNN-based attack setups
Mesozoic biostratigraphic, paleoenvironmental, and paleobiogeographic synthesis, equatorial Atlantic
Cretaceous sediments from Ocean Drilling Program Leg 159 on the Côte d’Ivoire-Ghana Marginal Ridge (CIGMR), eastern equatorial Atlantic, are characterized by distinct stratigraphic changes in sedimentary facies associated with changes in the composition of the clayey and organic fractions, as well as of the calcareous nannofossil, radiolarian, foraminiferal, and palynomorph assemblages. In the absence of reliable magnetostratigraphic information, an integrated biostratigraphy provides the only means used to calibrate the geologic history of the Leg 159 area.
The existence of marine depositional environments as early as the late Aptian to early Albian close to the Leg 159 drill sites puts constraints on the timing of the opening of the equatorial Atlantic gateway. Marine sedimentation on the ridge suggests that the West African and South American cratons were largely detached at this segment of the margin by the middle to late Albian. During the Cenomanian to Coniacian the ridge appears to have remained in an elevated position with concurrent low deposition or condensation (Site 959), high carbonate debris accumulation (Site 960), and even erosion (Site 962). Total organic Carbon measurements and microfaunal data lead us to suggest that, following the early opening of the seaway during the Albian, circulation remained restricted in the fragmented sub-basins of the CIGMR. It probably was not until the Santonian that a deep-water connection and circulation system became established between the Central and the South Atlantic. The sedimentary and faunal record at Site 959 show that a rapid subsidence occurred during the Santonian, with sub-calcite compensation depth conditions maintained until and beyond the Cretaceous/Tertiary boundary
Clinical significance of Akt and HER2/neu overexpression in African-American and Latina women with breast cancer
The dinoflagellate cyst genera <i>Achomosphaera</i> Evitt 1963 and <i>Spiniferites</i> Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al. 1973) Londeix et al. 2009, Spiniferites rubinus (Rossignol 1962 ex Rossignol 1964) Sarjeant 1970, and Thalassiphora balcanica Baltes & 1971. This summary forms the basis for a set of papers that follows, where points raised during the workshops are explored in greater detail
The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
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