Design of a middleware for QoS-aware distribution transparent content delivery

Developers of distributed multimedia applications face a diversity of multimedia formats, streaming platforms and streaming protocols. Furthermore, support for end-to-end quality-of-service (QoS) is a crucial factor for the development of future distributed multimedia systems. This paper discusses the architecture, design and implementation of a QoS-aware middleware platform for content delivery. The platform supports the development of distributed multimedia applications and can deliver content with QoS guarantees. QoS support is offered by means of an agent infrastructure for QoS negotiation and enforcement. Properties of content are represented using a generic content representation model described using the OMG Meta Object Facility (MOF) model. A content delivery framework manages stream paths for content delivery despite differences in streaming protocols and content encoding. The integration of the QoS support, content representation and content delivery framework results in a QoS-aware middleware that enables representation transparent and location transparent delivery of content

THINGS+: New norms and metadata for the THINGS database of 1,854 object concepts and 26,107 natural object images

To study visual object processing, the need for well-curated object concepts and images has grown significantly over the past years. To address this we have previously developed THINGS (Hebart et al., 2019), a large-scale database of 1,854 systematically sampled object concepts with 26,107 high-quality naturalistic images of these concepts. With THINGS+ we aim to extend THINGS by adding concept-specific and image-specific norms and metadata. Concept-specific norms were collected for all 1,854 object concepts for the object properties real-world size, manmadeness, preciousness, liveliness, heaviness, naturalness, ability to move, graspability, holdability, ability to be moved, pleasantness, and arousal. Further, we extended high-level categorization to 53 superordinate categories and collected typicality ratings for members of all 53 categories. Image-specific metadata includes measures of nameability and recognizability for objects in all 26,107 images. To this end, we asked participants to provide labels for prominent objects depicted in each of the 26,107 images and measured the alignment with the original object concept. Finally, to present example images in publications without copyright restrictions, we identified one new public domain image per object concept. In this study we demonstrate a high consistency of property (r = 0.92-0.99, M = 0.98, SD = 0.34) and typicality ratings (r = 0.88-0.98; M = 0.96, SD = 0.19), with arousal ratings as the only exception (r = 0.69). Correlations of our data with external norms were moderate to high for object properties (r = 0.44-0.95; M = 0.85, SD = 0.32) and typicality scores (r = 0.72-0.88; M = 0.79, SD = 0.18), again with the lowest validity for arousal (r = 0.30 - 0.52). To summarize, THINGS+ provides a broad, externally-validated extension to existing object norms and an important extension to THINGS as a general resource of object concepts, images, and category memberships. Our norms, metadata, and images provide a detailed selection of stimuli and control variables for a wide range of research interested in object processing and semantic memory

Female age and reproductive stage influence copulation patterns in mountain gorillas’ variable mating system

Variation in mating systems and in individuals’ copulation patterns can have important consequences for the genetic structure of a population and ultimately its evolution. Whilst most gorilla sub-species form single-male, polygynous reproductive groups, mountain gorillas have both single-male and multimale reproductive groups. Considerable research has investigated the mating patterns of males in these multimale groups, but comparatively little is known about females. We investigated the copulation patterns of 71 female mountain gorillas over 13 years. We found that most sexually active, fecundable females in multimale groups had multiple mating partners. Females’ copulation patterns varied based on their reproductive stage, mating most often and with the greatest number of partners when they were pregnant, and least often when they had young dependent offspring. Females copulated throughout pregnancy, with pregnant females copulating more frequently in single-male groups than in multimale groups. Mating also varied with age, with older females mating less often and with fewer partners. Our findings confirm that when females transfer between single-male and multimale groups, they predominantly switch from copulating with one male to copulating with multiple males, and that females are also flexibly adjusting their copulation patterns across their lifetimes. This highlights the considerable variability of the mountain gorillas mating system, particularly from the female perspective, and the importance of accounting for within-species variation in copulation patterns. Significance statement Patterns of mating can vary both between individuals of the same species and within individuals across their lives. These patterns influence the genetic structure of a population. By examining copulation patterns in female mountain gorillas, we demonstrate that whilst females in single-male groups have only one mating partner, females in multi-male groups predominantly have multiple partners across a year. They also alter their copulation patterns across their lifetimes, copulating less often and with fewer partners as they age, and copulating most when pregnant. Our results highlight the flexibility with which female mountain gorillas can adjust their copulation patterns across their lifetimes, as the costs and benefits of copulation shift

Mountain gorillas maintain strong affiliative biases for maternal siblings despite high male reproductive skew and extensive exposure to paternal kin

Evolutionary theories predict that sibling relationships will reflect a complex balance of cooperative and competitive dynamics. In most mammals, dispersal and death patterns mean that sibling relationships occur in a relatively narrow window during development and/or only with same-sex individuals. Besides humans, one notable exception is mountain gorillas, in which non-sex-biased dispersal, relatively stable group composition, and the long reproductive tenures of alpha males mean that animals routinely reside with both maternally and paternally related siblings, of the same and opposite sex, throughout their lives. Using nearly 40,000 hr of behavioral data collected over 14 years on 699 sibling and 1235 non-sibling pairs of wild mountain gorillas, we demonstrate that individuals have strong affiliative preferences for full and maternal siblings over paternal siblings or unrelated animals, consistent with an inability to discriminate paternal kin. Intriguingly, however, aggression data imply the opposite. Aggression rates were statistically indistinguishable among all types of dyads except one: in mixed-sex dyads, non-siblings engaged in substantially more aggression than siblings of any type. This pattern suggests mountain gorillas may be capable of distinguishing paternal kin but nonetheless choose not to affiliate with them over non-kin. We observe a preference for maternal kin in a species with a high reproductive skew (i.e. high relatedness certainty), even though low reproductive skew (i.e. low relatedness certainty) is believed to underlie such biases in other non-human primates. Our results call into question reasons for strong maternal kin biases when paternal kin are identifiable, familiar, and similarly likely to be long-term groupmates, and they may also suggest behavioral mismatches at play during a transitional period in mountain gorilla society

Dissecting the two mechanisms of scramble competition among the Virunga mountain gorillas

Two mechanisms have been proposed to explain why scramble competition can increase the travel requirements of individuals within larger groups. Firstly, individuals in larger groups may be more likely to encounter food sites where other group members have already eaten, leading to greater asynchronous “individual” travel to find fresh sites. Secondly, when food sites are aggregated into patches, larger groups may need to visit more patches to obtain the same amount of food per capita, leading to greater synchronous “group” travel between patches. If the first mechanism can be mitigated by increasing group spread, then we expect the second mechanism to be more sensitive to group size. Here, we examine the individual travel and group travel of the Virunga mountain gorillas, along with potential implications for the two mechanisms of scramble competition. Asynchronous individual travel accounted for 67% of the total travel time, and the remainder arose from group travel. Group spread increased significantly for larger groups, but not enough to prevent an increase in individual travel. Contrary to expectations, group travel decreased with size among most groups, and we found only limited evidence of patch depletion that would cause the second mechanism of scramble competition. Collectively, our results illustrate how the influence of group size can differ for individual travel versus group travel, just as it differs among species for overall travel. Studies that distinguish between the two mechanisms of scramble competition may enhance our understanding of ecological constraints upon group size, including potential differences between frugivores and folivores

Fine-scale genetic structure analyses suggest further male than female dispersal in mountain gorillas

BACKGROUND: Molecular studies in social mammals rarely compare the inferences gained from genetic analyses with field information, especially in the context of dispersal. In this study, we used genetic data to elucidate sex-specific dispersal dynamics in the Virunga Massif mountain gorilla population (Gorilla beringei beringei), a primate species characterized by routine male and female dispersal from stable mixed-sex social groups. Specifically, we conducted spatial genetic structure analyses for each sex and linked our genetically-based observations with some key demographic and behavioural data from this population. RESULTS: To investigate the spatial genetic structure of mountain gorillas, we analysed the genotypes of 193 mature individuals at 11 microsatellite loci by means of isolation-by-distance and spatial autocorrelation analyses. Although not all males and females disperse, female gorillas displayed an isolation-by-distance pattern among groups and a signal of dispersal at short distances from their natal group based on spatial autocorrelation analyses. In contrast, male genotypes were not correlated with spatial distance, thus suggesting a larger mean dispersal distance for males as compared to females. Both within sex and mixed-sex pairs were on average genetically more related within groups than among groups. CONCLUSIONS: Our study provides evidence for an intersexual difference in dispersal distance in the mountain gorilla. Overall, it stresses the importance of investigating spatial genetic structure patterns on a sex-specific basis to better understand the dispersal dynamics of the species under investigation. It is currently poorly understood why some male and female gorillas disperse while others remain in the natal group. Our results on average relatedness within and across groups confirm that groups often contain close relatives. While inbreeding avoidance may play a role in driving female dispersal, we note that more detailed dyadic genetic analyses are needed to shed light on the role of inbreeding avoidance as an ultimate cause of female dispersal in mountain gorillas

An assessment of African lion Panthera leo sociality via social network analysis: prerelease monitoring for an ex situ reintroduction program

The wild population of the African lion Panthera leo continues to decline, requiring alternate conservation programs to be considered. One such program is ex situ reintroduction. Prior to release, long-term monitoring and assessment of behavior is required to determine whether prides and coalitions behave naturally and are sufficiently adapted to a wild environment. Social network analysis (SNA) can be used to provide insight into how the pride as a whole and individuals within it, function. Our study was conducted upon 2 captive-origin prides who are part of an ex situ reintroduction program, and 1 wild pride of African lion. Social interactions were collected at all occurrence for each pride and categorized into greet, social grooming, play, and aggression. Betweenness centrality showed that offspring in each pride were central to the play network, whereas degree indicated that adults received (indegree) the greatest number of overall social interactions, and the adult males of each pride were least likely to initiate (outdegree) any interactions. Through the assessment of individual centrality and degree values, a social keystone adult female was identified for each pride. Social network results indicated that the 2 captive-origin prides had formed cohesive social units and possessed relationships and behaviors comparable with the wild pride for the studied behaviors. This study provided the first SNA comparison between captive-bred origin and a wild pride of lions, providing valuable information on individual and pride sociality, critical for determining the success of prides within an ex situ reintroduction program

Orangutans (Pongo pygmaeus) do not Form Expectations Based on Their Partner’s Outcomes

Several primate species form expectations based on other’s outcomes. These individuals respond negatively when their outcomes differ from their partners’. The function and evolutionary pathway of this behavior are unknown, in part because all of the species which have thus far shown the response have similar life history patterns. In particular, all share traits related to a gregarious lifestyle, intelligence, and cooperativeness. The goal of the current paper was to test whether inequity is a homology among primates or a convergence based on some other characteristic by comparing one species known to show social comparisons, the chimpanzee, to another great ape which differs on several of these life history characteristics. Using a protocol identical to one used previously with chimpanzees, we tested whether orangutans, an intelligent but predominantly solitary species with few opportunities to cooperate, responded similarly. To allow for a strong comparison with chimpanzees (and other species), we used socially housed adults of both sexes, tested with members of their social group. We find that orangutans do not respond negatively to inequity, supporting previous findings and indicating that inequity responses in apes are likely a convergence based on either sociality or cooperative tendency. These results in such closely related species highlight the need for additional comparative studies to better understand the function and evolution of social behaviors

Middleware Platform Management based on Portable Interceptors

Object middleware is an enabling technology for distributed applications that are required to operate in heterogeneous computing and communication environments. Although hiding distribution aspects to application designers proves beneficial, in an operational environment system managers may need detailed information on information flows and the locality of objects in order to track problems or tune the system. Therefore, hooks are required inside the processing core of the middleware to obtain inside-information and to influence the processing of information flows. We present the use of portable interceptors for the management of CORBA as well as COM/DCOM middleware. Management information is structured in a middleware technology independent way, using XML for representation. Our approach shows two aspects of “management transparency”: application designers are not burdened with designing management functionality, and system managers can manage CORBA and (D)COM from a single set of management tools

Dominance rank but not body size influences female reproductive success in mountain gorillas

According to life history theory, natural selection has shaped trade-offs for allocating energy among growth, reproduction and maintenance to maximize individual fitness. In social mammals body size and dominance rank are two key variables believed to influence female reproductive success. However, few studies have examined these variables together, particularly in long-lived species. Previous studies found that female dominance rank correlates with reproductive success in mountain gorillas (Gorilla beringei beringei), which is surprising given they have weak dominance relationships and experience seemingly low levels of feeding competition. It is not currently known whether this relationship is primarily driven by a positive correlation between rank and body size. We used the non-invasive parallel laser method to measure two body size variables (back breadth and body length) of 34 wild adult female mountain gorillas, together with long-term dominance and demography data to investigate the interrelationships among body size, dominance rank and two measures of female reproductive success (inter-birth interval N = 29 and infant mortality N = 64). Using linear mixed models, we found no support for body size to be significantly correlated with dominance rank or female reproductive success. Higher-ranking females had significantly shorter inter-birth intervals than lower-ranking ones, but dominance rank was not significantly correlated with infant mortality. Our results suggest that female dominance rank is primarily determined by factors other than linear body dimensions and that high rank provides benefits even in species with weak dominance relationships and abundant year-round food resources. Future studies should focus on the mechanisms behind heterogeneity in female body size in relation to trade-offs in allocating energy to growth, maintenance and lifetime reproductive success