476 research outputs found

    Context dependent species interaction outcomes in ant-plant protection mutualisms

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    We often study the outcomes of species interactions, whether they be predation, competition, or mutualism, at one site in a single year. However, we increasingly recognize that species interaction outcomes are not static, but context dependent by varying along many ecological axes. Here, I asked to what extent and along what axes are ant-plant protection interactions, in which plants provide rewards for ants that in turn defend plants from herbivores, context dependent. First, a meta-analytic summary of published studies on ant-plant protection interactions revealed that interaction outcomes are on average mutualistic, and context dependency occurred due to plant reward type (domatia vs food bodies vs extrafloral nectaries), ant species richness, and latitude. Second, in a case study in the Sonoran Desert, extrafloral nectar production caused context dependent mutualistic and antagonistic ant-plant interactions, despite largely commensalistic interaction outcomes. These results suggest some ecological axes resulting in context dependency in mutualisms

    Callers’ attitudes and experiences of UK breastfeeding helpline support

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    Background: Breastfeeding peer support, is considered to be a key intervention for increasing breastfeeding duration rates. Whilst a number of national organisations provide telephone based breastfeeding peer support, to date there have been no published evaluations into callers’ experiences and attitudes of this support. In this study we report on the descriptive and qualitative insights provided by 908 callers as part of an evaluation of UK-based breastfeeding helpline(s). Methods: A structured telephone interview, incorporating Likert scale responses and open-ended questions was undertaken with 908 callers over May to August, 2011 to explore callers’ experiences of the help and support received via the breastfeeding helpline(s). Results: Overall satisfaction with the helpline was high, with the vast majority of callers’ recalling positive experiences of the help and support received. Thematic analysis was undertaken on all qualitative and descriptive data recorded during the evaluation, contextualised within the main areas addressed within the interview schedule in terms of ‘contact with the helplines’; ‘experiences of the helpline service’, ‘perceived effectiveness of support provision’ and ‘impact on caller wellbeing’. Conclusion: Callers valued the opportunity for accessible, targeted, non-judgmental and convenient support. Whilst the telephone support did not necessarily influence women’s breastfeeding decisions, the support they received left them feeling reassured, confident and more determined to continue breastfeeding. We recommend extending the helpline service to ensure support can be accessed when needed, and ongoing training and support for volunteers. Further advertising and promotion of the service within wider demographic groups is warranted

    Ultrafast optical generation of coherent phonons in CdTe1-xSex quantum dots

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    We report on the impulsive generation of coherent optical phonons in CdTe0.68Se0.32 nanocrystallites embedded in a glass matrix. Pump probe experiments using femtosecond laser pulses were performed by tuning the laser central energy to resonate with the absorption edge of the nanocrystals. We identify two longitudinal optical phonons, one longitudinal acoustic phonon and a fourth mode of a mixed longitudinal-transverse nature. The amplitude of the optical phonons as a function of the laser central energy exhibits a resonance that is well described by a model based on impulsive stimulated Raman scattering. The phases of the coherent phonons reveal coupling between different modes. At low power density excitations, the frequency of the optical coherent phonons deviates from values obtained from spontaneous Raman scattering. This behavior is ascribed to the presence of electronic impurity states which modify the nanocrystal dielectric function and, thereby, the frequency of the infrared-active phonons

    Report of the Lancet Commission on the Value of Death: bringing death back into life

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    The story of dying in the 21st century is a story of paradox. While many people are overtreated in hospitals with families and communities relegated to the margins, still more remain undertreated, dying of preventable conditions and without access to basic pain relief. The unbalanced and contradictory picture of death and dying is the basis for this Commission

    New Non-Intravenous Routes for Benzodiazepines in Epilepsy: A Clinician Perspective.

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    Benzodiazepines represent the first-line treatment for the acute management of epileptic seizures and status epilepticus. The emergency use of benzodiazepines must be timely, and because most seizures occur outside of the hospital environment, there is a significant need for delivery methods that are easy for nonclinical caregivers to use and administer quickly and safely. In addition, the ideal route of administration should be reliable in terms of absorption. Rectal diazepam is the only licensed formulation in the USA, whereas rectal diazepam and buccal midazolam are currently licensed in the EU. However, the sometimes unpredictable absorption with rectal and buccal administration means they are not ideal routes. Several alternative routes are currently being explored. This is a narrative review of data about delivery methods for benzodiazepines alternative to the intravenous and oral routes for the acute treatment of seizures. Unconventional delivery options such as direct delivery to the central nervous system or inhalers are reported. Data show that intranasal diazepam or midazolam and the intramuscular auto-injector for midazolam are as effective as rectal or intravenous diazepam. Head-to-head comparisons with buccal midazolam are urgently needed. In addition, the majority of trials focused on children and adolescents, and further trials in adults are warranted

    Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

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    The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
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