2,545 research outputs found

    Assessing and mitigating impacts of motorboat noise on nesting damselfish

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    This is the final version. Available on open access from Elsevier via the DOI in this recordMotorboats are a pervasive, growing source of anthropogenic noise in marine environments, with known impacts on fish physiology and behaviour. However, empirical evidence for the disruption of parental care remains scarce and stems predominantly from playback studies. Additionally, there is a paucity of experimental studies examining noise-mitigation strategies. We conducted two field experiments to investigate the effects of noise from real motorboats on the parental-care behaviours of a common coral-reef fish, the Ambon damselfish Pomacentrus amboinensis, which exhibits male-only egg care. When exposed to motorboat noise, we found that males exhibited vigilance behaviour 34% more often and spent 17% more time remaining vigilant, compared to an ambient-sound control. We then investigated nest defence in the presence of an introduced conspecific male intruder, incorporating a third noise treatment of altered motorboat-driving practice that was designed to mitigate noise exposure via speed and distance limitations. The males spent 22% less time interacting with the intruder and 154% more time sheltering during normal motorboat exposure compared to the ambient-sound control, with nest-defence levels in the mitigation treatment equivalent to those in ambient conditions. Our results reveal detrimental impacts of real motorboat noise on some aspects of parental care in fish, and successfully demonstrate the positive effects of an affordable, easily implemented mitigation strategy. We strongly advocate the integration of mitigation strategies into future experiments in this field, and the application of evidence-based policy in our increasingly noisy world.Natural Environment Research Council (NERC)Australian Research Council (ARC)University of ExeterSwiss National Science Foundatio

    Association of polymorphisms in genes of factors involved in regulation of splicing of cystic fibrosis transmembrane conductance regulator mRNA with acute respiratory distress syndrome in children with pneumonia

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    Abstract Background Previous work has demonstrated a strong association between lung injury in African American children with pneumonia and a polymorphic (TG)mTn region in cystic fibrosis transmembrane conductance (CFTR) involved in the generation of a nonfunctional CFTR protein lacking exon 9. A number of splicing factors that regulate the inclusion/exclusion of exon 9 have been identified. The objective of this study was to determine whether genetic variants in these splicing factors were associated with acute respiratory distress syndrome (ARDS) in children with pneumonia. Methods This is a prospective cohort genetic association study of lung injury in African American and non-Hispanic Caucasian children with community-acquired pneumonia evaluated in the emergency department or admitted to the hospital. Linkage-disequilibrium-tag single nucleotide polymorphisms (LD-tag SNPs) in genes of the following splicing factors (followed by gene name) involved in exon 9 skipping PTB1 (PTBP1), SRp40 (SFRS1), SR2/ASF (SFRS5), TDP-43 (TARDBP), TIA-1 (TIA1), and U2AF65 (U2AF2) were genotyped. SNPs in the gene of the splicing factor CELF2 (CELF2) were selected by conservation score. Multivariable analysis was used to examine association between genotypes and ARDS. Results The African American cohort (n = 474) had 29 children with ARDS and the non-Hispanic Caucasian cohort (n = 304) had 32 children with ARDS. In the African American group multivariable analysis indicated that three variants in CELF2, rs7068124 (p = 0.004), rs3814634 (p = 0.032) and rs10905928 (p = 0.044), and two in TIA1, rs2592178 (p = 0.005) and rs13402990 (p = 0.018) were independently associated with ARDS. In the non-Hispanic Caucasian group, a single variant in CELF2, rs2277212 (p = 0.014), was associated with increased risk of developing ARDS. Conclusions The data indicate that SNPs in CELF2 may be associated with the risk of developing ARDS in both African American and non-Hispanic Caucasian children with pneumonia and suggest that the potential role of the splicing factor CELF2 in ARDS should be explored further.http://deepblue.lib.umich.edu/bitstream/2027.42/134745/1/13054_2016_Article_1454.pd

    Low-pathogenicity Mycoplasma spp. alter human monocyte and macrophage function and are highly prevalent among patients with ventilator-acquired pneumonia.

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    BACKGROUND: Ventilator-acquired pneumonia (VAP) remains a significant problem within intensive care units (ICUs). There is a growing recognition of the impact of critical-illness-induced immunoparesis on the pathogenesis of VAP, but the mechanisms remain incompletely understood. We hypothesised that, because of limitations in their routine detection, Mycoplasmataceae are more prevalent among patients with VAP than previously recognised, and that these organisms potentially impair immune cell function. METHODS AND SETTING: 159 patients were recruited from 12 UK ICUs. All patients had suspected VAP and underwent bronchoscopy and bronchoalveolar lavage (BAL). VAP was defined as growth of organisms at >10(4) colony forming units per ml of BAL fluid on conventional culture. Samples were tested for Mycoplasmataceae (Mycoplasma and Ureaplasma spp.) by PCR, and positive samples underwent sequencing for speciation. 36 healthy donors underwent BAL for comparison. Additionally, healthy donor monocytes and macrophages were exposed to Mycoplasma salivarium and their ability to respond to lipopolysaccharide and undertake phagocytosis was assessed. RESULTS: Mycoplasmataceae were found in 49% (95% CI 33% to 65%) of patients with VAP, compared with 14% (95% CI 9% to 25%) of patients without VAP. Patients with sterile BAL fluid had a similar prevalence to healthy donor BAL fluid (10% (95% CI 4% to 20%) vs 8% (95% CI 2% to 22%)). The most common organism identified was M. salivarium. Blood monocytes from healthy volunteers incubated with M. salivarium displayed an impaired TNF-α response to lipopolysaccharide (p=0.0003), as did monocyte-derived macrophages (MDMs) (p=0.024). MDM exposed to M. salivarium demonstrated impaired phagocytosis (p=0.005). DISCUSSION AND CONCLUSIONS: This study demonstrates a high prevalence of Mycoplasmataceae among patients with VAP, with a markedly lower prevalence among patients with suspected VAP in whom subsequent cultures refuted the diagnosis. The most common organism found, M. salivarium, is able to alter the functions of key immune cells. Mycoplasmataceae may contribute to VAP pathogenesis.This study was funded by the Hospital Infection Society, Wellcome Trust/Department of Health Health Innovation Challenge Fund (HICF)(0510/078) and Sir Jules Thorn Charitable Trust (03/JTA).This is the final version of the article. It first appeared from BMJ Publishing Group via http://dx.doi.org/10.1136/thoraxjnl-2015-20805

    Cardiovascular Magnetic Resonance Imaging-Based Computational Fluid Dynamics/Fluid-Structure Interaction Pilot Study to Detect Early Vascular Changes in Pediatric Patients with Type 1 Diabetes

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    We hypothesized that pediatric patients with type 1 diabetes have cardiac magnetic resonance (CMR) detectable differences in thoracic aortic wall properties and hemodynamics leading to significant local differences in indices of wall shear stress, when compared with age-matched control subjects without diabetes. Pediatric patients with type 1 diabetes were recruited from Children’s Hospital of Wisconsin and compared with controls. All underwent morning CMR scanning, 4-limb blood pressure, brachial artery reactivity testing, and venipuncture. Patient-specific computational fluid dynamics modeling with fluid–structure interaction, based on CMR data, determined regional time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). Twenty type 1 diabetic subjects, median age 15.8 years (11.6–18.4) and 8 controls 15.4 years (10.3–18.2) were similar except for higher glucose, hemoglobin A1c, and triglycerides for type 1 diabetic subjects. Lower flow-mediated dilation was seen for those with type 1 diabetes (6.5) versus controls (7.8), p = 0.036. For type 1 diabetic subjects, the aorta had more regions with high TAWSS when compared to controls. OSI maps appeared similar. Flow-mediated dilation positively correlated with age at diabetes diagnosis (r = 0.468, p = 0.038) and hemoglobin A1c (r = 0.472, p = 0.036), but did not correlate with aortic distensibility, TAWSS, or OSI. TAWSS did not correlate with any clinical parameter for either group. CMR shows regional differences in aortic wall properties for young diabetic patients. Some local differences in wall shear stress indices were also observed, but a longitudinal study is now warranted

    Exponential Random Graph Modeling for Complex Brain Networks

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    Exponential random graph models (ERGMs), also known as p* models, have been utilized extensively in the social science literature to study complex networks and how their global structure depends on underlying structural components. However, the literature on their use in biological networks (especially brain networks) has remained sparse. Descriptive models based on a specific feature of the graph (clustering coefficient, degree distribution, etc.) have dominated connectivity research in neuroscience. Corresponding generative models have been developed to reproduce one of these features. However, the complexity inherent in whole-brain network data necessitates the development and use of tools that allow the systematic exploration of several features simultaneously and how they interact to form the global network architecture. ERGMs provide a statistically principled approach to the assessment of how a set of interacting local brain network features gives rise to the global structure. We illustrate the utility of ERGMs for modeling, analyzing, and simulating complex whole-brain networks with network data from normal subjects. We also provide a foundation for the selection of important local features through the implementation and assessment of three selection approaches: a traditional p-value based backward selection approach, an information criterion approach (AIC), and a graphical goodness of fit (GOF) approach. The graphical GOF approach serves as the best method given the scientific interest in being able to capture and reproduce the structure of fitted brain networks

    Non-flat universe and interacting dark energy model

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    For non-flat universe of k≠0k\not=0, we investigate a model of the interacting holographic dark energy with cold dark matter (CDM). There exists a mixture of two components arisen from decaying of the holographic dark energy into CDM. In this case we use the effective equations of state (ωΛeff,ωmeff\omega^{\rm eff}_{\rm \Lambda}, \omega^{\rm eff}_{\rm m}) instead of the native equations of state (ωΛ,ωm)\omega_{\rm \Lambda},\omega_{\rm m}). Consequently, we show that interacting holographic energy models in non-flat universe cannot accommodate a transition from the dark energy to the phantom regime.Comment: 12 pages, 4 figures, version to appear in PL

    The MIF antagonist ISO-1 attenuates corticosteroid-insensitive inflammation and airways hyperresponsiveness in an ozone-induced model of COPD

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    Copyright © 2016 Russell et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine associated with acute and chronic inflammatory disorders and corticosteroid insensitivity. Its expression in the airways of patients with chronic obstructive pulmonary disease (COPD), a relatively steroid insensitive inflammatory disease is unclear, however. Methods. Sputum, bronchoalveolar lavage (BAL) macrophages and serum were obtained from nonsmokers, smokers and COPD patients. To mimic oxidative stress-induced COPD, mice were exposed to ozone for six-weeks and treated with ISO-1, a MIF inhibitor, and/or dexamethasone before each exposure. BAL fluid and lung tissue were collected after the final exposure. Airway hyperresponsiveness (AHR) and lung function were measured using whole body plethysmography. HIF-1α binding to the Mif promoter was determined by Chromatin Immunoprecipitation assays. Results. MIF levels in sputum and BAL macrophages from COPD patients were higher than those from non-smokers, with healthy smokers having intermediate levels. MIF expression correlated with that of HIF-1α in all patients groups and in ozone-exposed mice. BAL cell counts, cytokine mRNA and protein expression in lungs and BAL, including MIF, were elevated in ozone-exposed mice and had increased AHR. Dexamethasone had no effect on these parameters in the mouse but ISO-1 attenuated cell recruitment, cytokine release and AHR. Conclusion MIF and HIF-1α levels are elevated in COPD BAL macrophages and inhibition of MIF function blocks corticosteroid-insensitive lung inflammation and AHR. Inhibition of MIF may provide a novel anti-inflammatory approach in COPD

    Extraocular, rod-like photoreceptors in a flatworm express xenopsin photopigment

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    Animals detect light using opsin photopigments. Xenopsin, a recently classified subtype of opsin, challenges our views on opsin and photoreceptor evolution. Originally thought to belong to the Gαi-coupled ciliary opsins, xenopsins are now understood to have diverged from ciliary opsins in pre-bilaterian times, but little is known about the cells that deploy these proteins, or if they form a photopigment and drive phototransduction. We characterized xenopsin in a flatworm, Maritigrella crozieri, and found it expressed in ciliary cells of eyes in the larva, and in extraocular cells around the brain in the adult. These extraocular cells house hundreds of cilia in an intra-cellular vacuole (phaosome). Functional assays in human cells show Maritigrella xenopsin drives phototransduction primarily by coupling to Gαi. These findings highlight similarities between xenopsin and c-opsin and reveal a novel type of opsin-expressing cell that, like jawed vertebrate rods, encloses the ciliary membrane within their own plasma membrane

    Optical forces through guided light deflections

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    Optical trapping and manipulation typically relies on shaping focused light to control the optical force, usually on spherical objects. However, one can also shape the object to control the light deflection arising from the light-matter interaction and, hence, achieve desired optomechanical effects. In this work we look into the object shaping aspect and its potential for controlled optical manipulation. Using a simple bent waveguide as example, our numerical simulations show that the guided deflection of light efficiently converts incident light momentum into optical force with one order-of-magnitude improvement in the efficiency factor relative to a microbead, which is comparable to the improvement expected from orthogonal deflection with a perfect mirror. This improvement is illustrated in proof-of-principle experiments demonstrating the optical manipulation of two-photon polymerized waveguides. Results show that the force on the waveguide exceeds the combined forces on spherical trapping handles. Furthermore, it shows that static illumination can exert a constant force on a moving structure, unlike the position-dependent forces from harmonic potentials in conventional trapping. © 2013 Optical Society of America
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