5,041 research outputs found

    Potential for repurposing the personal care product preservatives bronopol and bronidox as broad-spectrum antibiofilm agents for topical application

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    Objectives: Bacterial biofilms represent a major impediment to healing in chronic wounds and are largely refractory to the antibacterial agents currently used in wound management. From a repurposing screen of compounds considered safe for topical application in humans, we report the identification of the personal care product preservatives bronopol and bronidox as broad-spectrum antibiofilm agents and potential candidates for reducing biofilm burden in chronic wounds. Methods: Antibiofilm activity was assessed by viable counting against single-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa in the Calgary Biofilm Device, and against mixed-species biofilms of the two organisms growing on nitrocellulose discs. Results: Bronopol and bronidox exhibited broad-spectrum antibiofilm activity that encompassed the two major wound pathogens, S. aureus and P. aeruginosa. When impregnated into gauze dressings at their existing maximum authorized concentrations for safe use and placed onto an established mixed-species biofilm, bronopol and bronidox completely eradicated P. aeruginosa and achieved an ∼5 log10 reduction in the S. aureus population. The antibiofilm action of bronopol and bronidox was attributed to their ability to kill slow- or non-growing bacteria found in biofilms, and both compounds exhibited synergistic antibiofilm effects in combination with established wound-treatment agents. Conclusions: Bronopol and bronidox kill bacteria regardless of growth state, a property that endows them with broad-spectrum antibiofilm activity. As this effect is observed at concentrations authorized for use on human skin, these compounds represent promising candidates for the treatment of chronic wounds

    Testing social learning of anti-predator responses in juvenile jackdaws: the importance of accounting for levels of agitation

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Social learning is often assumed to help young animals respond appropriately to potential threats in the environment. We brought wild, juvenile jackdaws briefly into captivity to test whether short exposures to conspecific vocalizations are sufficient to promote anti-predator learning. Individuals were presented with one of two models-a stuffed fox representing a genuine threat, or a toy elephant simulating a novel predator. Following an initial baseline presentation, juveniles were trained by pairing models with either adult mobbing calls, indicating danger, or contact calls suggesting no danger. In a final test phase with no playbacks, birds appeared to have habituated to the elephant, regardless of training, but responses to the fox remained high throughout, suggesting juveniles already recognized it as a predator before the experiment began. Training with mobbing calls did seem to generate elevated escape responses, but this was likely to be a carry-over effect of the playback in the previous trial. Overall, we found little evidence for social learning. Instead, individuals' responses were mainly driven by their level of agitation immediately preceding each presentation. These results highlight the importance of accounting for agitation in studies of anti-predator learning, and whenever animals are held in captivity for short periods.G.E.M. and A.T. were supported by a BBSRC David Phillips Fellowship to A.T. (BB/H021817/1 and BB/H021817/2). V.E.L. was supported by a Natural Environment Research Council Studentship

    Testing relationship recognition in wild jackdaws (Corvus monedula)

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    This is the author accepted manuscriptAccording to the social intelligence hypothesis, understanding the challenges faced by social animals is key to understanding the evolution of cognition. In structured social groups, recognising the relationships of others is often important for predicting the outcomes of interactions. Third-party relationship recognition has been widely investigated in primates, but studies of other species are limited. Furthermore, few studies test for third-party relationship recognition in the wild, where cognitive abilities are deployed in response to natural socio-ecological pressures. Here, we used playback experiments to investigate whether wild jackdaws (Corvus monedula) track changes in their own relationships and the relationships of others. Females were presented with ‘infidelity simulations’: playbacks of their male partner copulating with a neighbouring female, and their male neighbour copulating with another female, against a congruent control. Our results showed substantial inter-individual variation in responses, but females did not respond more strongly to infidelity playbacks, indicating that jackdaws may not attend and/or respond to relationship information in this experimental context. Our results highlight the need for further study of relationship recognition and other cognitive traits that facilitate group-living in the wild, particularly in non-primates and in a wider range of social systems.BBSRC David Phillips Fellowshi

    Social learning about dangerous people by wild jackdaws

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    This is the final version. Available on open access from the Royal Society via the DOI in this recordData accessibility Data and R scripts associated with this work are available via Figshare (doi:10.6084/m9.figshare.7828781)For animals that live alongside humans, people can present both an opportunity and a threat. Previous studies have shown that several species can learn to discriminate between individual people and assess risk based on prior experience. To avoid potentially costly encounters, it may also pay individuals to learn about dangerous people based on information from others. Social learning about anthropogenic threats is likely to be beneficial in habitats dominated by human activity, but experimental evidence is limited. Here, we tested whether wild jackdaws (Corvus monedula) use social learning to recognize dangerous people. Using a within-subjects design, we presented breeding jackdaws with an unfamiliar person near their nest, combined with conspecific alarm calls. Subjects that heard alarm calls showed a heightened fear response in subsequent encounters with the person compared to a control group, reducing their latency to return to the nest. This study provides important evidence that animals use social learning to assess the level of risk posed by individual humans.Natural Environment Research Council (NERC)La Région Auvergne-Rhône-AlpesBiotechnology and Biological Sciences Research Council (BBSRC

    Young children's cognitive achievement: home learning environment, language and ethnic background

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    For decades, research has shown differences in cognitive assessment scores between White and minority ethnic group(s) learners as well as differences across different minority ethnic groups. More recent data have indicated that the home learning environment and languages spoken can impact cognitive assessment and other corollary outcomes. This study uses the Millennium Cohort Study to jointly assess how minority ethnic group, home learning environment and home languages predict child cognitive assessment scores. Regression analyses were conducted using two assessment measures. The following is hypothesised: (1) cognitive achievement scores vary by minority ethnic group, (2) more home learning environment in early childhood leads to higher cognitive development scores and (3) English only in the home yields the highest cognitive scores while no English in the home yields the lowest. Findings reveal that there are differences in cognitive scores along ethnic group categories although there are also some unexpected findings. Home learning environment does not play as large a role as was predicted in raising the assessment scores overall for learners while speaking English in the home does, irrespective of ethnic background

    Survey of H-alpha emission from thirty nearby dwarf galaxies

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    Measurements of the H-alpha flux from 30 neighboring dwarf galaxies are presented. After correction for absorption, these fluxes are used to estimate the star formation rate (SFR). The SFR for 18 of the galaxies according to the H-alpha emission are compared with estimates of the SFR from FUV magnitudes obtained with the GALEX telescope. These are in good agreement over the range log[SFR] = [-3,0]M sun/yr.Comment: 18 pages, 10 figures, 3 table

    Software for full-color 3D reconstruction of the biological tissues internal structure

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    A software for processing sets of full-color images of biological tissue histological sections is developed. We used histological sections obtained by the method of high-precision layer-by-layer grinding of frozen biological tissues. The software allows restoring the image of the tissue for an arbitrary cross-section of the tissue sample. Thus, our method is designed to create a full-color 3D reconstruction of the biological tissue structure. The resolution of 3D reconstruction is determined by the quality of the initial histological sections. The newly developed technology available to us provides a resolution of up to 5 - 10 {\mu}m in three dimensions.Comment: 11 pages, 8 figure

    Environmental influences on familial discordance of phenotype in people with homocystinuria: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Non-heritable factors may have an influence on the clinical expression of monogenic inherited metabolic diseases.</p> <p>Case presentation</p> <p>This is a case report of a man whose mother had been diagnosed late in childhood with pyridoxine responsive homocystinuria with lens dislocation and neurodevelopmental delay. These severe complications were not observed in her son who was pyridoxine unresponsive but who had been treated appropriately since early infancy.</p> <p>Conclusion</p> <p>The phenotype of people with homocystinuria can be discordant within a family, with variability in metabolic and clinical expression depending upon both the genotype and therapeutic interventions. Offspring of people with homocystinuria should be screened in early infancy and, if positive, treated appropriately whether they have pyridoxine responsive or unresponsive disease.</p

    The role of animal cognition in human-wildlife interactions

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    This is the final version. Available on open access from Frontiers Media via the DOI in this record. Humans have a profound effect on the planet’s ecosystems, and unprecedented rates of human population growth and urbanization have brought wild animals into increasing contact with people. For many species, appropriate responses toward humans are likely to be critical to survival and reproductive success. Although numerous studies have investigated the impacts of human activity on biodiversity and species distributions, relatively few have examined the effects of humans on the behavioral responses of animals during human-wildlife encounters, and the cognitive processes underpinning those responses. Furthermore, while humans often present a significant threat to animals, the presence or behavior of people may be also associated with benefits, such as food rewards. In scenarios where humans vary in their behavior, wild animals would be expected to benefit from the ability to discriminate between dangerous, neutral and rewarding people. Additionally, individual differences in cognitive and behavioral phenotypes and past experiences with humans may affect animals’ ability to exploit human-dominated environments and respond appropriately to human cues. In this review, we examine the cues that wild animals use to modulate their behavioral responses toward humans, such as human facial features and gaze direction. We discuss when wild animals are expected to attend to certain cues, how information is used, and the cognitive mechanisms involved. We consider how the cognitive abilities of wild animals are likely to be under selection by humans and therefore influence population and community composition. We conclude by highlighting the need for long-term studies on free-living, wild animals to fully understand the causes and ecological consequences of variation in responses to human cues. The effects of humans on wildlife behavior are likely to be substantial, and a detailed understanding of these effects is key to implementing effective conservation strategies and managing human-wildlife conflict.Biotechnology & Biological Sciences Research Council (BBSRC

    Entanglement in nuclear quadrupole resonance

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    Entangled quantum states are an important element of quantum information techniques. We determine the requirements for states of quadrupolar nuclei with spins >1/2 to be entangled. It was shown that entanglement is achieved at low temperature by applying a magnetic field to a quadrupolar nuclei possess quadrupole moments, which interacts with the electricfield gradient produced by the charge distribution in their surroundings.Comment: 9 pages, 5 figure
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