37 research outputs found

    First report of a leopard (Panthera pardus)-bonobo (Pan paniscus) encounter at the LuiKotale study site, Democratic Republic of the Congo

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    Predation is a major cause of mortality in non-human primates, and considered a selective force in the evolution of primate societies. Although larger body size is considered as protection against predation, evidence for predation on great apes by carnivores comes from chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla), and orangutans (Pongo spp.). Here, we describe the first encounter between wild bonobos (Pan paniscus) and a leopard (Panthera pardus). A single leopard was confronted by a group of habituated bonobos for three hours. Two adult males and one adolescent female bonobo actively harassed the leopard, which remained still for most of the encounter and reacted only to close approaches by bonobos. While no predation was observed, their behaviours confirm that bonobos perceive leopards as potential predators. Our report adds novel information to descriptions from other African ape species, and sheds light on the behavioural repertoire of bonobos’ anti-predation strategies. For future investigations, we suggest tagging leopards to remotely monitor their movements and allow assessment of encounter rates as one of several factors influencing predation pressure

    Bumble Bees (Bombus spp) along a Gradient of Increasing Urbanization

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    BACKGROUND: Bumble bees and other wild bees are important pollinators of wild flowers and several cultivated crop plants, and have declined in diversity and abundance during the last decades. The main cause of the decline is believed to be habitat destruction and fragmentation associated with urbanization and agricultural intensification. Urbanization is a process that involves dramatic and persistent changes of the landscape, increasing the amount of built-up areas while decreasing the amount of green areas. However, urban green areas can also provide suitable alternative habitats for wild bees. METHODOLOGY/PRINCIPAL FINDINGS: We studied bumble bees in allotment gardens, i.e. intensively managed flower rich green areas, along a gradient of urbanization from the inner city of Stockholm towards more rural (periurban) areas. Keeping habitat quality similar along the urbanization gradient allowed us to separate the effect of landscape change (e.g. proportion impervious surface) from variation in habitat quality. Bumble bee diversity (after rarefaction to 25 individuals) decreased with increasing urbanization, from around eight species on sites in more rural areas to between five and six species in urban allotment gardens. Bumble bee abundance and species composition were most affected by qualities related to the management of the allotment areas, such as local flower abundance. The variability in bumble bee visits between allotment gardens was higher in an urban than in a periurban context, particularly among small and long-tongued bumble bee species. CONCLUSIONS/SIGNIFICANCE: Our results suggest that allotment gardens and other urban green areas can serve as important alternatives to natural habitats for many bumble bee species, but that the surrounding urban landscape influences how many species that will be present. The higher variability in abundance of certain species in the most urban areas may indicate a weaker reliability of the ecosystem service pollination in areas strongly influenced by human activity

    Exclusion of a major role for the PTEN tumour-suppressor gene in breast carcinomas

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    PTEN is a novel tumour-suppressor gene located on chromosomal band 10q23.3. This region displays frequent loss of heterozygosity (LOH) in a variety of human neoplasms including breast carcinomas. The detection of PTEN mutations in Cowden disease and in breast carcinoma cell lines suggests that PTEN may be involved in mammary carcinogenesis. We here report a mutational analysis of tumour specimens from 103 primary breast carcinomas and constitutive DNA from 25 breast cancer families. The entire coding region of PTEN was screened by single-strand conformation polymorphism (SSCP) analysis and direct sequencing using intron-based primers. No germline mutations could be identified in the breast cancer families and only one sporadic carcinoma carried a PTEN mutation at one allele. In addition, all sporadic tumours were analysed for homozygous deletions by differential polymerase chain reaction (PCR) and for allelic loss using the microsatellite markers D10S215, D10S564 and D10S573. No homozygous deletions were detected and only 10 out of 94 informative tumours showed allelic loss in the PTEN region. These results suggest that PTEN does not play a major role in breast cancer formation. 1999 Cancer Research Campaig

    Performance studies of the CMS strip tracker before installation

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    Letteratura e mezzi di trasporto

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    Il progetto si propone di organizzare un convegno e un percorso didattico multimediale finalizzato a un master professionalizzante per gli studenti che attivi risorse scientifiche internazionali e istituzioni culturali nazionali sul tema letteratura e mezzi di trasporto

    Hemostatically Active Proteinase Produced by <i>Aspergillus ochraceus</i>: Key Specific Properties and Effect on Target Proteins

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    The effect of A. ochraceus proteinase on the proteins of the human hemostasis system, fibrin, fibrinogen, plasminogen, protein C, and factor X, was studied. These proteins are key targets for proteolytic enzymes in therapy and diagnosis of thromboembolic complications. It was shown that A. ochraceus proteinase efficiently cleaves fibrin and fibrinogen, but does not act precisely, since it cuts all three subunits of these proteins. The proteinase did not have an activating effect on the plasminogen, a precursor of plasminogen and plasmin. The proteinase of A. ochraceus was shown to be the first fungal proteinase with proven activating activity towards the human hemostasis system factors protein C and factor X. For protein C activation, A. ochraceus proteinase requires Ca2+ ions. The enzyme was found to be sensitive to thrombin inhibitors, but not to plasmin inhibitors. A proteolytic action profile of the scope of this proteinase as a proteinase with activating protein C, factor X, and plasmin-like activity was proposed

    Effect of Proteinase from Aspergillus fumigatus on Blood Plasma Proteins

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    Abstract: Extracellular proteinase of the opportunistic Aspergillus fumigatus D-1 strain (molecular weight ~33 kDa, pI 4.6) was isolated. It was shown that proteinase hydrolyzes casein, fibrin, fibrinogen, albumin, and hemoglobin to varying degrees. However, proteolytic activity with respect to globular proteins of blood plasma was comparable to fibrinolytic activity. Proteinase did not coagulate human fibrinogen and bovine fibrinogen; it also did not coagulate human and rabbit blood plasma without dilution and when diluted twice. The plasminogen-activating activity of A. fumigatus D-1 extracellular proteinase was found, which may indicate its ability to indirect fibrinolysis

    Action of extracellular proteases of aspergillus flavus and aspergillus ochraceus micromycetes on plasma hemostasis proteins

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    In this study, we investigated the properties of proteolytic enzymes of two species of Aspergillus, Aspergillus flavus 1 (with a high degree of pathogenicity) and Aspergillus ochraceus L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both Aspergillus fully hydrolyzed thrombi in 120–180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin

    Cell-Mediated Immune Ontogeny Is Affected by Sex but Not Environmental Context in a Long-Lived Primate Species

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    Ecoimmunology conceptualizes the role of immunity in shaping life history in a natural context. Within ecoimmunology, macroimmunology is a framework that explains the effects of habitat and spatial differences on variation in immune phenotypes across populations. Within these frameworks, immune ontogeny—the development of the immune system across an individual life span—has received little attention. Here, we investigated how immune ontogeny from birth until adulthood is affected by age, sex, and developmental environment in a long-lived primate species, the bonobo. We found a progressive, significant decline of urinary neopterin levels, a marker for the cell-mediated immune response, from birth until 5 years of age in both sexes. The overall pattern of age-related neopterin changes was sex-specific, with males having higher urinary neopterin levels than females in the first 3 years of life, and females having higher levels than males between 6 and 8 years. Environmental condition (zoo-housed vs. wild) did not influence neopterin levels, nor did age-related changes in neopterin levels differ between environments. Our data suggest that the post-natal development of cell-mediated immune ontogeny is sex-specific but does not show plasticity in response to environmental conditions in this long-lived primate species. This indicates that cell-mediated immune ontogeny in the bonobo follows a stereotypic and maybe a genetically determined pattern that is not affected by environmental differences in pathogen exposure and energy availability, but that sex is an important, yet often overlooked factor shaping patterns of immune ontogeny. Investigating the causes and consequences of variation in immunity throughout life is critical for our understanding of life-history evolution and strategies, mechanisms of sexual selection, and population dynamics with respect to pathogen susceptibility. A general description of sex-specific immune ontogeny as done here is a crucial step in this direction, particularly when it is considered in the context of a species’ ecology and evolutionary history.publishe
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