278 research outputs found
Using air quality monitoring to reduce second-hand smoke exposure in homes : the AFRESH feasibility study
ACKNOWLEDGEMENTS This research was supported by a grant from the Medical Research Councilâs Public Health Intervention Development scheme. The research team would like to thank Christine Foster and the staff and volunteers of Healthy Valleys, Lanarkshire, for their support in carrying out this work, and Beverley Scheepers and Joanne Buchan of ASH Scotland for their assistance in developing training material. FUNDING Medical Research Council PHIND Grant MR/M026159/1.Peer reviewedPublisher PD
The nest as fortress: defensive behavior of Polybia emaciata, a mud-nesting eusocial wasp
The swarm-founding wasp Polybia emaciata is unusual among eusocial Vespidae because it uses mud, rather than wood pulp, as its primary nest construction material. Polybia emaciata nests are more durable than similarly sized paper nests. We tested the hypothesis that the defensive behavior of this wasp may have been modified to take advantage of their strong nests in defense against vertebrate attacks. We simulated vertebrate disturbances by tapping on, and breathing in, P. emaciata nests and similarly sized P. occidentalis paper nests in the same location at the same time. Polybia emaciata responses to disturbance were qualitatively different from those of P. occidentalis. The latter exit the nest and attack, while P. emaciata workers typically fled or entered the nest, attacking only after repeated and extended disturbances. We conclude that durable nest material may permit predator avoidance behavior in P. emaciata. We compare the defensive responses of P. emaciata workers with those of other swarm-founding Vespidae, and discuss several selective forces that could cause the evolution of species variation in nest defense behavior
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Specializations of birds that attend army ant raids: an ecological approach to cognitive and behavioral studies.
Tropical birds forage at army ant raids on several continents. Obligate foraging at army ant raids evolved several times in the Neotropical true antbird family (Thamnophilidae), and recent evidence suggests a diversity of bird species from other families specialize to varying degrees on army ant exploitation. Army ant raids offer access to high prey densities, but the ant colonies are mobile and widely spaced. Successful army ant exploitation requires solving a complex foraging problem because army ant raids are unpredictable in space and time. Birds can counteract the challenges posed by the ants by using strategies that raise their chances of detecting army ant raids, and birds can use additional strategies to track army ant colonies they have located. Some features of army ant biology, such as their conspicuous swarms and columns, above-ground activity, and regular cycles of behavior, provide opportunities for birds to increase their effectiveness at exploiting raids. Changes in sensory, cognitive and behavioral systems may all contribute to specialized army ant exploitation in a bird population. The combination of specializations that are employed may vary independently among bird species and populations. The degree of army ant exploitation by birds varies geographically with latitude and elevation, and with historical patterns such as centers of distribution of obligate thamnophilid antbirds. We predict the set of specializations a given bird population exhibits will depend on local ecology, as well as phylogenetic history. Comparative approaches that focus on these patterns may indicate ecological and evolutionary factors that have shaped the costs and benefits of this foraging strategy. The development of army ant exploitation in individual birds is poorly understood, and individual expression of these specializations may depend on a combination of genetic adaptation with cognitive plasticity, possibly including social and experiential learning. Future studies that measure developmental changes and quantify individual differences in army ant exploitation are needed to establish the mechanisms underlying this behavior.This work was supported by National Science Foundation grant IOS-1209072 and Drexel University funds (to S.OâD.); the Gates Cambridge Scholarship and Murray Edwards College Overseas Bursary (to C.L.); and the University of Cambridge, Clare College and BBSRC (to N.S.C.).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.beproc.2012.09.00
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Interactions between pyroclastic density currents : insights from analog experiments
During some explosive volcanic eruptions, multiple pyroclastic density currents have been produced within a short time span of each other and flowed through the same area. This creates the potential for the currents to interact, specifically in a way where a leading current is produced, and then a similar trailing current is produced a short time later and possibly flows into the leading current. The leading current, having changed the ambient surroundings from normal air, may then have an effect on the dynamics and behavior of the trailing current. To examine this effect, we designed scaled experiments to produce an analogue leading current and a trailing current that flows into it. The experiments took place in both an air medium and a water medium. The results of the experiments showed that the behavior of the trailing current may change as a result of interacting with the leading current. After certain intervals of time between currents, the trailing current had a longer final runout distance compared to the leading current it flowed through. This is caused by the presence of a plume created by the leading current when it reverses buoyancy. At intermediate heights above the bed, after moderate amounts of time between currents, the leading plume is less dense than the newly created trailing plume, and the trailing current cannot rise, and the momentum stays in the body of the trailing current. This accelerates the trailing current, which decreases sedimentation rate, and allows the current to runout to a greater distance before lifting off. At low heights and great heights above the bed, the leading plume is denser than the trailing plume, and the trailing plume can then rise without impediment. In natural pyroclastic density currents, the magnitude by which the leading current affects the trailing current depends on the rise time of the leading plume.Geological Science
Characterising the Exposure of Prison Staff to Second-Hand Tobacco Smoke
Acknowledgements This project was funded by the National Institute for Health Research Public Health Research Programme (project number 15/55/44). We are grateful to all the staff at the Scottish Prison Service and in HMP Kilmarnock and HMP Addiewell who assisted with this study. We are also extremely grateful to David Walker, Ruaraidh Dobson and Mrs Flora Buthlay for their help with data collection and retrieval of instruments from prisons, and to Dr Steve Turner for helpful comments on an earlier draft. KH, HS, GL, ED gratefully acknowledge core funding from UK MRC and Chief Scientist Office (MC_UU_12017/12; SPHSU12; MC/PC/13027 partnership grant) for their work within prison settings. We acknowledge the contribution of our co-investigators in the TIPs research team to the overall design of the TIPs study (Professor Linda Bauld, Dr Kathleen Boyd, Dr Philip Conaglen, Dr Peter Craig, Douglas Eadie, Professor Alastair Leyland, Professor Jill Pell).Peer reviewedPublisher PD
Protecting children from second-hand tobacco smoke: evidence of major progress but a final push is needed in the UK
First paragraph: We welcome the findings of Tattan-Birch and Jarvis1 in demonstrating a 90% reduction in objective measures of exposure to second-hand tobacco smoke [SHS] among children in England between 1998 and 2018. Their important study uses Health Survey of England [HSE] data on salivary cotinine, as a marker of nicotine intake and SHS exposure, to show that geometric mean values of cotinine reduced from 0.50 to 0.05 ng/ml. Their results additionally show that by 2018 over 93% of children in England were classified as living in a smoke-free home environment. Policymakers in Scotland have achieved similar improvements with a 2014 world-leading target to reduce the proportion of children exposed to SHS at home to under 6% by 2020.2 The change in social norms relating to smoking around children has been significant and well documented3 over the past two decades and, coupled to reductions in adult smoking prevalence, now mean that the majority of children in England have no detectable cotinine in their saliva
Development Of A Smoke-free Homes Intervention For Parents: An Intervention Mapping Approach
Exposure to second-hand smoke (SHS) is associated with various ill-health outcomes for children and adults. Barriers to creating a smoke-free home (SFH) are well-documented. Feasible and effective interventions to create smoke-free homes for disadvantaged households are lacking. Interventions that include providing parents with objective information about the impact of smoking on air quality in their home may be particularly effective. This study describes the development of a novel, theory- and evidence-based smoke-free homes intervention using objectively-assessed air quality feedback. The intervention was developed using the six-step Intervention Mapping (IM) protocol. Findings from literature reviews, focus groups with parents, interviews with health/care professionals, and expert panel discussions shaped intervention content and materials. Findings highlighted the importance of parents receiving personalised information on second-hand smoke levels in their home. Professionals considered the use of non-judgemental language essential in developed materials. Previous literature highlighted the need to address home smoking behaviour at a household rather than individual level. The AFRESH intervention is modular and designed to be delivered face-to-face by healthcare professionals. It includes up to five meetings with parents, two sets of five daysâ air quality monitoring and personalised feedback, and the option to involve other household members in creating a smoke-free home using educational, motivational, and goal setting techniques. Further research is needed to evaluate the acceptability and effectiveness of the AFRESH intervention and which specific groups of parents this intervention will most likely benefit. IM was a useful framework for developing this complex intervention. This paper does not present evaluation findings
First evidence of cryptotephra in palaeoenvironmental records associated with Norse occupation sites in Greenland
The Norse/Viking occupation of Greenland is part of a dispersal of communities across the North Atlantic coincident with the supposed Medieval Warm Period of the late 1st millennium AD. The abandonment of the Greenland settlements has been linked to climatic deterioration in the Little Ice Age as well as other possible explanations. There are significant dating uncertainties over the time of European abandonment of Greenland and the potential influence of climatic deterioration. Dating issues largely revolve around radiocarbon chronologies for Norse settlements and associated mire sequences close to settlement sites. Here we show the potential for moving this situation forward by a combination of palynological, radiocarbon and cryptotephra analyses of environmental records close to three âiconicâ Norse sites in the former Eastern Settlement of Greenland â Herjolfsnes, Hvalsey and GarĂ°ar (the modern Igaliku). While much work remains to be undertaken, our results show that palynological evidence can provide a useful marker for both the onset and end of Norse occupation in the region, while the radiocarbon chronologies for these sequences remain difficult. Significantly, we here demonstrate the potential for cryptotephra to become a useful tool in resolving the chronology of Norse occupation, when coupled with palynology. For the first time, we show that cryptotephra are present within palaeoenvironmental sequences located within or close to Norse settlement ruin-groups, with tephra horizons detected at all three sites. While shard concentrations were small at Herjolfsnes, concentrations sufficient for geochemical analyses were detected at Igaliku and Hvalsey. WDS-EPMA analyses of these tephra indicate that, unlike the predominantly Icelandic tephra sources reported in the Greenland ice core records, the tephra associated with the Norse sites correlate more closely with volcanic centres in the Aleutians and Cascades. Recent investigations of cryptotephra dispersal from North American centres, along with our new findings, point to the potential for cryptotephra to facilitate hypothesis testing, providing a key chronological tool for refining the timing of Norse activities in Greenland (e.g. abandonment) and of environmental contexts and drivers (e.g. climate forcing)
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