bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bacteria and the evolution of honest signals. The case of ornamental throat feathers in spotless starlings
Authors: Ruiz‐Rodríguez Magdalena , Tomás Gustavo , Martín‐Gálvez David , Ruiz‐Castellano Cristina , Soler Juan José 
Published: November 2014

Summary

Mechanisms guaranteeing reliability of messages are essential in understanding the underlying information and evolution of signals. Micro‐organisms may degrade signalling traits and therefore influence the transmitted information and evolution of these characters. The role of micro‐organisms in animal signalling has, however, rarely been investigated.

Here, we explore a possible role for feather‐degrading bacteria driving the design of ornamental throat feathers in male spotless starlings (Sturnus unicolor). We estimated length, bacterial load, degradation status and susceptibility to degradation by keratinolytic bacteria in those feathers, compared with non‐ornamental adjacent feathers in males, as well as to throat feathers in females. In addition, the volume of the uropygial gland and its secretion was measured and the secretion extracted. We also experimentally evaluated the capacity of each secretion to inhibit growth of a keratinolytic bacterium.

The apical part of male ornamental throat feathers harboured more bacteria and degraded more quickly than the basal part; these patterns were not detected in female throat feathers or in non‐ornamental male feathers. Moreover, degradation status of male and female throat feathers did not differ, but was positively associated with feather bacterial density. Finally, the size of the uropygial gland in both males and females predicted volume and the inhibitory capacity of secretion against feather‐degrading bacteria. Only in males was uropygial gland size negatively associated with the level of feather degradation.

All results indicate differential susceptibility of different parts of throat feathers to keratinolytic bacterial attack, which supports the possibility that throat feathers in starlings reflect individual ability to combat feather‐degrading bacteria honestly. This is further supported by the relationship detected between antimicrobial properties of uropygial secretion and the level of feather degradation.

Our results suggest that selection pressures exerted by feather‐degrading bacteria on hosts may promote evolution of particular morphologies of secondary sexual traits with different susceptibility to bacterial degradation that reliably inform of their bacterial load. Those results will help to understand the evolution of ornamental signals.
Different foraging preferences of hummingbirds on artificial and natural flowers reveal mechanisms structuring plant–pollinator interactions
Authors: Maglianesi María A. , Böhning‐Gaese Katrin , Schleuning Matthias 
Published: November 2014

Summary

In plant–pollinator networks, the floral morphology of food plants is an important determinant of the interaction niche of pollinators. Studies on foraging preferences of pollinators combining experimental and observational approaches may help to understand the mechanisms behind patterns of interactions and niche partitioning within pollinator communities.

In this study, we tested whether morphological floral traits were associated with foraging preferences of hummingbirds for artificial and natural flower types in Costa Rica. We performed field experiments with artificial feeders, differing in length and curvature of flower types, to quantify the hummingbirds’ interaction niche under unlimited nectar resources. To quantify the interaction niche under real‐world conditions of limited nectar resources, we measured foraging preferences of hummingbirds for a total of 34 plant species.

Artificial feeders were visited by Eupherusa nigriventris and Phaethornis guy in the pre‐montane forest, and Lampornis calolaemus in the lower montane forest. Under experimental conditions, all three hummingbird species overlapped their interaction niches and showed a preference for the short artificial flower type over the long‐straight and the long‐curved flower types. Under natural conditions, the two co‐occurring hummingbird species preferred to feed on plant species with floral traits corresponding to their bill morphology. The short‐billed hummingbird E. nigriventris preferred to feed on short and straight flowers, whereas the long‐ and curved‐billed P. guy preferred long and curved natural flowers. The medium‐size billed species L. calolaemus preferred to feed on flowers of medium length and did not show preferences for plant species with specific corolla curvature.

Our results show that floral morphological traits constrain access by short‐billed hummingbird species to nectar resources. Morphological constraints, therefore, represent one important mechanism structuring trophic networks. In addition, other factors, such as competition and differences in resource quantity or quality, define the interaction niches of consumer species in real‐world communities, enforcing patterns of niche segregation between co‐occurring consumer species. This suggests that experimental studies are needed to disentangle effects of morphological constraints from those of competition for resources in plant–pollinator interactions and other types of trophic interactions.
A novel concept for continuous peripheral nerve blocks. Presentation of a new ultrasound‐guided device
Authors: ROTHE C. , STEEN‐HANSEN C. , MADSEN M. H. , LANGE K. H. W. 
Published: November 2014

BackgroundExisting techniques for placing and maintaining the position of peripheral nerve catheters are associated with variable success rates and frequent secondary failures. These factors may affect the clinical efficacy and usefulness of peripheral nerve catheters.MethodsWe developed a new concept and prototype for ultrasound‐guided in‐plane positioning and readjustment of peripheral nerve catheters (patent pending). The integrated catheter–needle prototype comprises three parts: a curved needle, a catheter with clear echogenic markings attached to the needle tail and a detachable hub allowing injection of local anesthetic while advancing the needle in the tissue. The system works like a suture and is introduced through the skin, passes in close relation to the nerve and exits through the skin. This allows in‐plane ultrasound guidance throughout the procedure both during initial positioning as well as during later in‐plane readjustment of the catheter. We tested the system in the popliteal region of two fresh cadavers in a preliminary proof of concept study.ResultsBoth initial placement and secondary readjustment were precise, judged by the catheter orifices placed close to the sciatic nerve in the popliteal fossa. Circumferential spread of 3‐ml isotonic saline around the sciatic nerve was observed on ultrasound images in both conditions.ConclusionPreliminary proof of concept of this novel method demonstrates that precise in‐plane ultrasound‐guided initial placement and secondary in‐plane readjustment is possible in fresh cadavers. Future studies should address the clinical efficacy and usefulness of this novel concept.
Mitochondrial effectors of cellular senescence: beyond the free radical theory of aging
Authors: Ziegler Dorian V. , Wiley Christopher D. , Velarde Michael C. 
Published: November 2014

SummaryCellular senescence is a process that results from a variety of stresses, leading to a state of irreversible growth arrest. Senescent cells accumulate during aging and have been implicated in promoting a variety of age‐related diseases. Mitochondrial stress is an effective inducer of cellular senescence, but the mechanisms by which mitochondria regulate permanent cell growth arrest are largely unexplored. Here, we review some of the mitochondrial signaling pathways that participate in establishing cellular senescence. We discuss the role of mitochondrial reactive oxygen species (ROS), mitochondrial dynamics (fission and fusion), the electron transport chain (ETC), bioenergetic balance, redox state, metabolic signature, and calcium homeostasis in controlling cellular growth arrest. We emphasize that multiple mitochondrial signaling pathways, besides mitochondrial ROS, can induce cellular senescence. Together, these pathways provide a broader perspective for studying the contribution of mitochondrial stress to aging, linking mitochondrial dysfunction and aging through the process of cellular senescence.
Teaching intensive interaction to paid carers: using the ‘communities of practice’ model to inform training
Authors: Rayner Kelly , Bradley Samantha , Johnson Gemma , Mrozik Jennifer H. , Appiah Afua , Nagra Maninder K. 
Published: November 2014

Accessible summary

This research project is about Intensive Interaction. Intensive Interaction is a way of communicating with people who have severe and profound learning disabilities and can be used with people who do not communicate with words.

We asked three paid carers that trained in Intensive Interaction about their experience and how training had changed their work with people with learning disabilities.

This research project matters to people with learning disabilities because it tries to find out the best way to train people to do this work. This could help make services better for everyone.

SummaryThe engagement of people with learning disabilities in social communication is crucial to the development of relationships with others, a sense of social inclusion and self‐worth. Intensive Interaction is an approach that can help carers develop their skills to engage people with severe and profound learning disabilities in personally relevant communication. Carers learn techniques by attending workshops offered by health and social care professionals, and this study seeks to explore the impact of one such training programme. This study used interpretative phenomenological analysis to explore the lived experience of Intensive Interaction training and practice of three paid carers who worked with people with learning disabilities. Three superordinate themes emerged from the analysis: ‘Investment’, ‘Outcomes’ and ‘Challenges’. Results suggest that participants had an overwhelmingly positive experience in learning and using Intensive Interaction and that coaching, supervision and support were vital. The clinical and practical implications for this are discussed.
Clinically used selective oestrogen receptor modulators increase LDL receptor activity in primary human lymphocytes
Authors: Cerrato F , Fernández‐Suárez M E , Alonso R , Alonso M , Vázquez C , Pastor O , Mata P , Lasunción M A , Gómez‐Coronado D 
Published: November 2014

Background and PurposeTreatment with selective oestrogen receptor modulators (SERMs) reduces low‐density lipoprotein (LDL) cholesterol levels. We assessed the effect of tamoxifen, raloxifene and toremifene and their combinations with lovastatin on LDL receptor activity in lymphocytes from normolipidaemic and familial hypercholesterolaemic (FH) subjects, and human HepG2 hepatocytes and MOLT‐4 lymphoblasts.Experimental ApproachLymphocytes were isolated from peripheral blood, treated with different compounds, and 1,1′‐dioctadecyl‐3,3,3,3′‐tetramethylindocarbocyanine perchlorate (DiI)‐labelled LDL uptake was analysed by flow cytometry.Key ResultsTamoxifen, toremifene and raloxifene, in this order, stimulated DiI‐LDL uptake by lymphocytes by inhibiting LDL‐derived cholesterol trafficking and subsequent down‐regulation of LDL receptor expression. Differently to what occurred in HepG2 and MOLT‐4 cells, only tamoxifen consistently displayed a potentiating effect with lovastatin in primary lymphocytes. The SERM‐mediated increase in LDL receptor activity was not altered by the anti‐oestrogen ICI 182 780 nor was it reproduced by 17β‐oestradiol. However, the tamoxifen‐active metabolite endoxifen was equally effective as tamoxifen. The SERMs produced similar effects on LDL receptor activity in heterozygous FH lymphocytes as in normal lymphocytes, although none of them had a potentiating effect with lovastatin in heterozygous FH lymphocytes. The SERMs had no effect in homozygous FH lymphocytes.Conclusions and ImplicationsClinically used SERMs up‐regulate LDL receptors in primary human lymphocytes. There is a mild enhancement between SERMs and lovastatin of lymphocyte LDLR activity, the potentiation being greater in HepG2 and MOLT‐4 cells. The effect of SERMs is independent of oestrogen receptors but is preserved in the tamoxifen‐active metabolite endoxifen. This mechanism may contribute to the cholesterol‐lowering action of SERMs.
Airway responses towards allergens – from the airway epithelium to T cells
Authors: Papazian D. , Hansen S. , Würtzen P. A. 
Published: November 2014

SummaryThe prevalence of allergic diseases such as allergic rhinitis is increasing, affecting up to 30% of the human population worldwide. Allergic sensitization arises from complex interactions between environmental exposures and genetic susceptibility, resulting in inflammatory T helper 2 (Th2) cell‐derived immune responses towards environmental allergens. Emerging evidence now suggests that an epithelial dysfunction, coupled with inherent properties of environmental allergens, can be responsible for the inflammatory responses towards allergens. Several epithelial‐derived cytokines, such as thymic stromal lymphopoietin (TSLP), IL‐25 and IL‐33, influence tissue‐resident dendritic cells (DCs) as well as Th2 effector cells. Exposure to environmental allergens does not elicit Th2 inflammatory responses or any clinical symptoms in nonatopic individuals, and recent findings suggest that a nondamaged, healthy epithelium lowers the DCs' ability to induce inflammatory T‐cell responses towards allergens. The purpose of this review was to summarize the current knowledge on which signals from the airway epithelium, from first contact with inhaled allergens all the way to the ensuing Th2‐cell responses, influence the pathology of allergic diseases.
Integrating invasion and disease in the risk assessment of live bird trade
Authors: Springborn Michael R. , Keller Reuben P. , Elwood Sarah , Romagosa Christina M. , Zambrana‐Torrelio Carlos , Daszak Peter 
Published: November 2014

AbstractAimInternational trade in plants and animals generates significant economic benefits. It also leads to substantial unintended impacts when introduced species become invasive, causing environmental disturbance or transmitting diseases that affect people, livestock, other wildlife or the environment. Policy responses are usually only implemented after these species become established and damages are already incurred. International agreements to control trade are likewise usually based on selection of species with known impacts. We aim to further develop quantitative invasive species risk assessment for bird imports and extend the tool to explicitly address disease threats.LocationUnited States of America.MethodsWe use a two‐step approach for rapid risk assessment based on the expected biological risks due to both the environmental and health impact of a potentially invasive wildlife species in trade. We assess establishment probability based on a model informed by historical observations and then construct a model of emerging infectious disease threat based on economic and ecological characteristics of the exporting country.ResultsWe illustrate how our rapid assessment tool can be used to identify high‐priority species for regulation based on a combination of the threat they pose for becoming established and vectoring emerging infectious diseases.Main conclusionsOur approach can be executed for a species in a matter of days and is nested in an economic decision‐making framework for determining whether the biological risk is justified by trade benefits.
Glucose‐lowering with exogenous insulin monotherapy in type 2 diabetes: dose association with all‐cause mortality, cardiovascular events and cancer
Authors: Holden S. E. , Jenkins‐Jones S. , Morgan C. Ll. , Schernthaner G. , Currie C. J. 
Published: November 2014

AimsTo evaluate the association between insulin exposure and all‐cause mortality, incident major adverse cardiovascular events (MACE) and incident cancer in people with type 2 diabetes treated with insulin monotherapy.MethodsFor this retrospective study, people with type 2 diabetes who progressed to insulin monotherapy from the year 2000 were identified from the UK Clinical Practice Research Datalink. The risks of progression to serious adverse outcomes were compared using Cox proportional hazards models. In the main analysis, insulin exposure was introduced into the model as prescribed international units per kilogram per day, as a cumulative, continuous, annually updated, time‐dependent covariable.ResultsA total of 6484 subjects with type 2 diabetes who progressed to treatment with insulin monotherapy from the year 2000 onwards were followed for a mean of 3.3 years. The event numbers were as follows: deaths, n = 1110; incident MACE, n = 342; incident cancers, n = 382. Unadjusted event rates were 61.3 deaths per 1000 person‐years, 26.4 incident MACE per 1000 person‐years and 24.6 incident cancers per 1000 person‐years. The adjusted hazard ratios in relation to 1‐unit increases in insulin dose were 1.54 [95% confidence interval (CI) 1.32–1.78] for all‐cause mortality, 1.37 (95% CI 1.05–1.81) for MACE and 1.35 (95% CI 1.04–1.75) for cancer.ConclusionsThere was an association between increasing exogenous insulin dose and increased risk of all‐cause mortality, MACE and cancer in people with type 2 diabetes. The limitations of observational studies mean that this should be further investigated using an interventional study design.
Invader immunology: invasion history alters immune system function in cane toads (Rhinella marina) in tropical Australia
Authors: Brown Gregory P. , Phillips Benjamin L. , Dubey Sylvain , Shine Richard 
Published: November 2014

AbstractBecause an individual's investment into the immune system may modify its dispersal rate, immune function may evolve rapidly in an invader. We collected cane toads (Rhinella marina) from sites spanning their 75‐year invasion history in Australia, bred them, and raised their progeny in standard conditions. Evolved shifts in immune function should manifest as differences in immune responses among the progeny of parents collected in different locations. Parental location did not affect the offspring's cell‐mediated immune response or stress response, but blood from the offspring of invasion‐front toads had more neutrophils, and was more effective at phagocytosis and killing bacteria. These latter measures of immune function are negatively correlated with rate of dispersal in free‐ranging toads. Our results suggest that the invasion of tropical Australia by cane toads has resulted in rapid genetically based compensatory shifts in the aspects of immune responses that are most compromised by the rigours of long‐distance dispersal.
A link between host dispersal and parasite diversity in two sympatric cichlids of Lake Tanganyika
Authors: Grégoir Arnout F. , Hablützel Pascal I. , Vanhove Maarten P. M. , Pariselle Antoine , Bamps Jolien , Volckaert Filip A. M. , Raeymaekers Joost A. M. 
Published: November 2014

SummaryA major goal in ecology is to unravel how species assemblages emerge and how they are structured across the landscape. Host–parasite systems are particularly interesting in this context, as limited host dispersal may promote the differentiation of parasite communities.We examined whether the patterns of species diversity inCichlidogyrus, a genus of monogenean parasitic flatworms with a direct life cycle, are consistent with the hypothesis that parasite diversity is driven by host dispersal. This was carried out by comparing two sympatric cichlid hosts (Tropheus mooriiandSimochromis diagramma) with contrasting dispersal abilities. Genetic connectivity among host populations along the Zambian shoreline of Lake Tanganyika was estimated using microsatellite genotyping.Cichlidogyrusparasites were isolated and identified morphologically to the species level.Simochromis diagramma, a host with a high dispersal capacity, was infected by a low number ofCichlidogyrusspecies, and the parasite assemblages were similar among host populations. In contrast,T. moorii, a host with a low dispersal capacity, was infected by a large number ofCichlidogyrusspecies, and the parasite assemblages differed strongly among host populations. These outcomes were thus as expected from the hypothesis.Because of the strong host specificity of theseCichlidogyrusspecies, a lack of connectivity among host populations might facilitate allopatric speciation of the parasite.
Factors affecting direction and strength of patient preferences for treatment of molar teeth with nonvital pulps
Authors: Vernazza C. R. , Steele J. G. , Whitworth J. M. , Wildman J. R. , Donaldson C. 
Published: November 2014

AbstractAimTo elicit the factors affecting willingness to pay (WTP) values for the preferred options of participants for dealing with a molar tooth with a nonvital pulp, a common but difficult problem.MethodologyA total of 503 patients were recruited from dental practices in the North East of England and interviewed. Their preferred treatment option for a molar tooth with a nonvital pulp (endodontics, extraction and various prosthetic restorative options) and WTP for this preferred option were elicited. Factors affecting preferred option and WTP were analysed using econometric modelling.ResultsOverall, 53% of the sample wished to save the tooth with a mean WTP of £373. The variance in WTP was high. Of those opting for extraction, the majority chose to leave a gap or have an implant. The preferred option was influenced by previous treatment experience. WTP was only influenced by having a low income.ConclusionsThe high level of variance in WTP and its relatively unpredictable nature pose difficult questions for policy makers trying to ensure the delivery of an equitable service. For dentists, it is important not to make assumptions about patient preference and strength of preference when making decisions. Ideally, WTP values should be considered alongside effectiveness data, and those on costs, in policy making.
Assessment of high‐resolution satellite rainfall estimation products in a streamflow model for flood prediction in the Bagmati basin, Nepal
Authors: Bajracharya S.R. , Shrestha M.S. , Shrestha A.B. 
Published: November 2014

AbstractThe use of appropriate hydrological models with real‐time satellite rainfall estimates can help mitigate flood damage, provide support to contingency planning, and provide warning to people threatened by floods. In this study, the simulated streamflow from the Geospatial Stream Flow Model (GeoSFM) using NOAA Climate Prediction Centre Rainfall Estimates Version 2.0 (RFE) data was compared with observed streamflow in the Bagmati basin. The model showed poor performance when forced with 2002 monsoon RFE. However, the simulated streamflow showed a significant improvement when using improved RFE by incorporating local rain gauge data into the rainfall estimate. Simulated streamflow was much closer to the observed discharge, with a Nash–Sutcliffe efficiency coefficient of 0.91, flow ratio of 1.1, and coefficient of determination of 0.92. Thus, improved RFE can be considered for use in flood prediction. A flood hazard map prepared using the extreme rainfall event showed an inundation area of 315 km2, 8.4% of the basin.