Wpływ spokrewnienia na strukturę przestrzenną i socjalną populacji dzika Sus scrofa w Puszczy Białowieskiej

Fitness benefits of sociality increase individual survival and reproductive success through a complex network of social interactions. Kin selection theory predicts that individuals increase their inclusive fitness through altruistic behaviours directed towards kin. Thus, preferential social interactions with relatives lead to the emergence of kin structures in the social system. Cohesive social groups, female philopatry, and high reproductive output of wild boar creates conditions for cooperation through kin selection and make the species a good biological model for studying kin structures. Yet, the role of kinship in shaping the social structure of wild boar populations is still poorly understood. The main goal of this study, conducted in Białowieża Primeval Forest (BPF) in 2007-2011, was to explore spatial and temporal patterns of social interactions in the wild boar population, and to determine the role of relatedness in shaping the emergent social structure of the species. A combination of behavioural (telemetry) and genetic (microsatellite DNA) data were used to investigate group structure and composition, dispersal patterns, and population structure of wild boar. Network techniques, association analyses, and estimates of lagged association rates were used to determine temporal and spatial structure of the social interactions in the studied population. A total of 141 wild boar were captured, 114 of which belonged to 16 marked groups and the rest were either solitary or belonged to unmarked groups. Telemetry-marked animals (n = 75) included all solitary wild boar and, on average, 66% of the groups’ members. Genetic analyses included all captured animals and samples collected by hunters in the Polish and Belarusian parts of the BPF (n = 411). All individuals were genotyped with a panel of 16 microsatellite loci. The average family group size estimated from the trapping data was 7 individuals. This result was consistent with analyses based on social interactions alone (association rates and network analysis). The vast majority of adult females and young animals were associated in groups, whereas adult males were mostly solitary. Individuals associated in groups were significantly more genetically related to each other than non-associating, solitary individuals. On average, the intra-group level of relatedness corresponded to second-degree relatives. Relatedness within a group was negatively correlated with group size. Members of the family groups showed extensive spatial overlap, whereas animals from different family groups shared little space. Wild boar in the study population formed non-random, preferential associations which were largely stable and long-lasting. The temporal stability of associations was particularly strong among adult females and animals forming family groups. Conversely, adult males formed short-lived associations disintegrating within a few days. High temporal stability of associations observed among animals forming groups implies strong group cohesion. There was a positive correlation between strength of social bond and genetic relatedness but kin-targeted interactions extending beyond spatial proximity of individuals were observed only among females. On the population level, there was a negative relationship between geographic distance and genetic relatedness. Spatial genetic structure was detected at small spatial scale corresponding to few home ranges. Genetic structure was maintained at the same distance in males and females. However, females showed a stronger relationship between genetic and spatial distance at short distances (0-1 km), whereas males showed stronger structuring in the distance class of 1-5 km. Assignment index provided little evidence for sex-biased dispersal, yet indicated a tendency towards greater dispersal in males. Telemetry data on dispersal provided results consistent with genetic data. Sex bias was manifested in dispersal distance, but not dispersal frequency, with females usually settling in the direct vicinity of the maternal home range and males few home ranges away from the natal site. Dispersal occurred at the age of 18-21 months. The social network, derived solely from association data, was spatially structured with well defined and cohesive social units. The units were also genetically distinct, with high intra-group and low inter-group genetic relatedness. Space utilised by the members of a given social unit overlapped extensively while little overlap was observed across social units. The genetic structure in the network can be interpreted as an emergent property of philopatry and spatial segregation of social groups. However, spatial distribution and overlap of individuals could not fully explain the association patterns and network structure. Association and genetic data indicated that active social preferences and targeted interactions played important roles in shaping the social structure of the population. The close match of the social structure revealed in social units and family groups (obtained from trapping data) indicated that they mirror the same level of social organisation. Sociality of wild boar, estimated by three network centrality measures, generally decreased with age of the individuals, and magnitude of age effect was modified by sex. Young wild boars showed the strongest grouping tendency and were the most diversely connected within the networks. The onset of dispersal marked a decrease in sociality, which was manifested stronger in males than in females. These results highlight the role of young wild boar in maintaining cohesion of the social network. Changes in sociality mirrored major transitions in wild boar ontogeny

Certain bivariate distributions and random processes connected with maxima and minima

It is well-known that [S(x)]^n and [F(x)]^n are the survival function and the distribution function of the minimum and the maximum of n independent, identically distributed random variables, where S and F are their common survival and distribution functions, respectively. These two extreme order statistics play important role in countless applications, and are the central and well-studied objects of extreme value theory. In this work we provide stochastic representations for the quantities [S(x)]^alpha and [F(x)]^beta, where alpha> 0 is no longer an integer, and construct a bivariate model with these margins. Our constructions and representations involve maxima and minima with a random number of terms. We also discuss generalizations to random process and further extensions

Long-lasting, kin-directed female interactions in a spatially structured wild boar social network

We thank W. Jędrzejewski for his support and logistical help in trapping wild boar. We are grateful to R. Kozak, A. Waszkiewicz and many students and volunteers for their help with fieldwork as well as to A. N. Bunevich, T. Borowik and local hunters for providing genetic samples. Genetic analyses were performed in the laboratory of the Department of Science for Nature and Environmental Resources, University of Sassari, Italy, with the help of L. Iacolina and D. Biosa. We are grateful to K. O’Mahony who revised English and to A. Widdig, K. Langergraber and one anonymous reviewer for valuable comments on the earlier version of the manuscript.Peer reviewedPublisher PD

The advantages of a spine coil over a torso coil in magnetic resonance imaging examination of the sternoclavicular joints

Purpose: There are two standard methods for an magnetic resonance imaging (MRI) examination of the sternoclavicular joints: with loop coils and the patient in the prone position, or with torso coils with the patient in a supine position. In some centres these joints are examined with the spine coil in a patient laying prone. There are no reports on the advantages of this method. Our hypothesis is that despite different MRI systems, application of a spine coil will improve examination quality. Material and methods: Twenty-one healthy volunteers (10 female, 11 male, mean age 25 years) were randomised into three groups and scanned using three different MRI scanners (1.5T: Siemens Avanto, Philips Ingenia, 3.0T: Philips Achieva). Each volunteer was examined twice: using a standard protocol with a torso coil and with a spine coil, in prone position. The two groups were compared with regard to the intensity of motion artefacts using the χ2 test, and to the signal-to-noise ratio with the Wilcoxon signed-rank test. Results: Application of a spine coil resulted in a significant decrease in the number of motion artefacts in all three planes (axial: p = 0.0004; sagittal: p < 0.0001; coronal: p = 0.0054). Moreover, the signal-to-noise ratio was significantly increased with the application of a spine coil (28.6 ± 8.6 vs. 18.5 ± 7.3, respectively; p = 0.0002). Conclusions: Application of a spine coil with the patient in a prone position is suitable for MRI evaluation of the sternoclavicular joints. It allows a higher signal-to-noise ratio and a lower intensity of motion artefacts to be obtained compared to a torso coil

Chmura obliczeniowa

Cloud computing is an approach to computing that leverages the efficient pooling of on- demand, self-managed virtual infrastructure that is consumed as a service. The launch of this model of data processing requires the appropriate hardware and software infrastructure, which currently are very expensive. Another problem is the law that is not adapted to modern IT solutions. Nevertheless, cloud computing is the fastest growing part of the IT market. This article provides information about benefits and limitations of public and private cloud computing. It focuses on definition of cloud computing, describing proposed solutions for private cloud computing offered by leading software manufacturers and financial and law factors that can decide about successful migration to the cloud

How do genetic relatedness and spatial proximity shape African swine fever infections in wild boar?

The importance of social and spatial structuring of wildlife populations for disease spread, though widely recognized, is still poorly understood in many host-pathogen systems. In particular, system-specific kin relationships among hosts can create contact heterogeneities and differential disease transmission rates. Here, we investigate how distance-dependent infection risk is influenced by genetic relatedness in a novel host-pathogen system: wild boar (Sus scrofa) and African swine fever (ASF).We hypothesized that infection risk would correlate positively with proximity and relatedness to ASF-infected individuals but expected those relationships to weaken with the distance between individuals due to decay in contact rates and genetic similarity.We genotyped 323 wild boar samples (243 ASF-negative and 80 ASF-positive) collected in north-eastern Poland in 2014–2016 and modelled the effects of geographic distance, genetic relatedness and ASF virus transmission mode (direct or carcass-based) on the probability of ASF infection. Infection risk was positively associated with spatial proximity and genetic relatedness to infected individuals with generally stronger effect of distance. In the high-contact zone (0–2 km), infection risk was shaped by the presence of infected individuals rather than by relatedness to them. In the medium-contact zone (2–5 km), infection risk decreased but was still associated with relatedness and paired infections were more frequent among relatives. At farther distances, infection risk further declined with relatedness and proximity to positive individuals, and was 60% lower among un-related individuals in the no-contact zone (33% in10–20 km) compared among relatives in the high-contact zone (93% in 0–2 km). Transmission mode influenced the relationship between proximity or relatedness and infection risk. Our results indicate that the presence of nearby infected individuals is most important for shaping ASF infection rates through carcass-based transmission, while relatedness plays an important role in shaping transmission rates between live animals

Rozwiązanie problemu nadmiernych drgań stropów budynku przemysłowego o konstrukcji stalowej

This paper deals with the problem of vibration that occurs in many industrial buildings. It covers the complete procedure of handling such tasks. Two buildings in a “Lubelski Wegiel S.A.” coal mine were examined in 2003 – 2005. Some years after building vibration of floors appeared (Figs 2-3). It was caused probably by modification in the building structures or improper maintenance of machines. Measurements and numerical simulations (Figs 4-5 and Tab. 1) showed that resonance appeared. It was stated that main elements of the structure were not in danger and vibration concern the floors only. Necessary modifications of the structures were designed (Figs 6-7). Testing measurements after bringing them into effect were conducted (Figs 8-11).W niniejszej pracy zajęto się problemem drgań pojawiających się w wielu budynkach przemysłowych. W latach 2003-2005 sprawdzono dwa budynki w kopalni węgla „Lubelski Węgiel S.A.” Kilka lat później pojawiły się drgania stropów w budynku, które zostały wywołane prawdopodobnie przez mody-fikacje wprowadzone w konstrukcji lub prze nieprawidłowe utrzymanie maszyn. Zarówno pomiary jak i symulacje numeryczne wykazały wystąpienie rezonansu. Stwierdzono, że główne elementy konstrukcji nie były zagrożone, a drgania dotyczyły tylko stropów. Zaprojektowano niezbędne modyfikacje konstrukcji i przeprowadzono testowe pomiary po ich wprowadzeniu