226 research outputs found

    Determining whether mate-searching males use directional information from female signals in Umbonia crassicornis

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    Abstract only availableVibrational communication is widespread in insect social and ecological interactions. In fact, it has been estimated that thousands of insect species use vibrational signals as a primary source of communication. During many interactions, such as courtship and predator encounters, it is necessary for individuals to locate the source of the vibrational signal. Although localization of this sort is important, the mechanisms that small insects use to locate the source of the vibrational signal are not known. We are studying mate localization in thornbug treehoppers, Umbonia crassicornis. These are small sap-feeding insects in which mate-searching males produce vibrational signals that are transmitted along the stems and leaves of their host plant during courtship. First, the male produces a vibrational signal that is detected by the female. The female responds with her own vibration, creating a duet which is repeated until the male reaches the female. We hypothesize that the female's vibrational signals provide directional information to searching males. In order to test this hypothesis, we recorded the routes traveled and decisions made by mate-searching males as well as audio of the male-female duets. Our preliminary data suggest that female signals do influence the paths that males take to find females. Our results will guide future research on the actual mechanisms used by treehoppers to determine the direction of a substrate vibration and will continue to provide important insights into insect social behavior, ecology, and evolution.NSF Undergraduate Mentoring in Environmental Biolog

    Determining whether mate-searching males use directional information from female signals in Umbonia crassicornis

    Get PDF
    Abstract only availableVibrational communication is widespread in insect social and ecological interactions. In fact, it has been estimated that thousands of insect species use vibrational signals as a primary source of communication. During many interactions, such as courtship and predator encounters, it is necessary for individuals to locate the source of the vibrational signal. Although localization of this sort is important, the mechanisms that small insects use to locate the source of the vibrational signal are not known. We are studying mate localization in thornbug treehoppers, Umbonia crassicornis (Hemiptera: Membracidae). These are small sap-feeding insects in which mate-searching males produce vibrational signals that are transmitted along the stems and leaves of their host plant during courtship. First, the male produces a vibrational signal that is detected by the female. The female responds with her own vibration, creating a duet which is repeated until the male reaches the female. We hypothesize that the female's vibrational signals provide directional information to searching males. In order to test this hypothesis, we recorded the routes traveled and decisions made by mate-searching males as well as audio of the male-female duets. Our preliminary data suggest that female signals do influence the paths that males take to find females. Our results will guide future research on the actual mechanisms used by treehoppers to determine the direction of a substrate vibration and will continue to provide important insights into insect social behavior, ecology, and evolution.NSF Undergraduate Mentoring in Environmental Biolog

    SN1991bg-like supernovae are associated with old stellar populations

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    SN1991bg-like supernovae are a distinct subclass of thermonuclear supernovae (SNe Ia). Their spectral and photometric peculiarities indicate their progenitors and explosion mechanism differ from `normal' SNe Ia. One method of determining information about supernova progenitors we cannot directly observe is to observe the stellar population adjacent to the apparent supernova explosion site to infer the distribution of stellar population ages and metallicities. We obtain integral field observations and analyse the spectra extracted from regions of projected radius ∼ kpc\sim\,\mathrm{kpc} about the apparent SN explosion site for 11 91bg-like SNe in both early- and late-type galaxies. We utilize full-spectrum spectral fitting to determine the ages and metallicities of the stellar population within the aperture. We find that the majority of the stellar populations that hosted 91bg-like supernovae have little recent star formation. The ages of the stellar populations suggest that that 91bg-like SN progenitors explode after delay times of >6 Gyr>6\,\mathrm{Gyr}, much longer than the typical delay time of normal SNe Ia, which peaks at ∼1 Gyr\sim 1\,\mathrm{Gyr}.Comment: 12 pages, 3 figures, 3 tables, submitted to Publications of the Astronomical Society of Australi

    Non-pharmacological and pharmacological interventions for the reduction or prevention of topographies of behaviours that challenge in people with intellectual disabilities:a systematic review and meta-analysis of randomised controlled trials

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    Background: People with intellectual disability show a high prevalence of behaviours that challenge. Clinical guidelines recommend that such behaviour should first be treated with non-pharmacological interventions, but research suggests off-label pharmaceuticals are commonly used. We aimed to evaluate the efficacy of non-pharmacological and pharmacological interventions for topographies of behaviours that challenge drawn from randomised controlled trials (RCTs). Methods: In this systematic review and meta-analysis, we searched PsycINFO, MEDLINE, Embase, CINAHL, and CENTRAL databases for RCT studies assessing an intervention (pharmacological or non-pharmacological) for behaviours that challenge (self-injury behaviour, aggression, destruction of property, irritability, and a composite overall measure) in participants with intellectual disability. The primary aim was to assess the efficacy of non-pharmacological and pharmacological interventions on behaviours that challenge. Secondary aims were to evaluate how effects varied over time and whether intervention, methodological, and participant characteristics moderate efficacy. We extracted standard mean difference (SMD) effect sizes (Cohen's d) from eligible studies and meta-analysed the data using a series of random effects models and subgroup analyses. This study was registered with PROSPERO 2021, CRD4202124997. Findings: Of 11 912 reports identified, 82 studies were included. 42 (51%) studies assessed non-pharmacological interventions and 40 (49%) assessed pharmacological interventions. Across all studies, 4637 people with intellectual disability aged 1–84 years (mean age 17·2 years) were included. 2873 (68·2%) were male, 1339 (28·9%) were female, and for 425 (9·2%) individuals, data on gender were not available. Data on ethnicity were unavailable. Small intervention effects were found for overall behaviours that challenge at post-intervention (SMD –0·422, 95% CI –0·565 to –0·279), overall behaviours that challenge at follow-up (–0·324, –0·551 to –0·097), self-injury behaviour at post-intervention (–0·238, –0·453 to –0·023), aggression at post-intervention (–0·438, –0·566 to –0·309), and irritability at post-intervention (–0·255, –0·484 to –0·026). No significant differences between non-pharmacological and pharmacological interventions were found for any topography of behaviours that challenge (all p&gt;0·05). Interpretation: A broad range of interventions for behaviours that challenge are efficacious with small effect sizes for people with intellectual disability. These findings highlight the importance of precision in the measurement of behaviours that challenge, and when operationalising intervention components and dosages. Funding: Cerebra.</p

    Conventional CT and PET/CT imaging in the evaluation and management of subsolid pulmonary nodules: an overview of the literature and author recommendations

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    This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

    Filtration-histogram based texture analysis and CALIPER based pattern analysis as quantitative CT techniques in idiopathic pulmonary fibrosis: head-to-head comparison

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    OBJECTIVE: To assess the prognostic performance of two quantitative CT (qCT) techniques in idiopathic pulmonary fibrosis (IPF) compared to established clinical measures of disease severity (GAP index). METHODS: Retrospective analysis of high-resolution CT scans for 59 patients (age 70.5 ± 8.8 years) with two qCT methods. Computer-aided lung informatics for pathology evaluation and ratings based analysis classified the lung parenchyma into six different patterns: normal, ground glass, reticulation, hyperlucent, honeycombing and pulmonary vessels. Filtration histogram-based texture analysis extracted texture features: mean intensity, standard deviation (SD), entropy, mean of positive pixels (MPPs), skewness and kurtosis at different spatial scale filters. Univariate Kaplan-Meier survival analysis assessed the different qCT parameters' performance to predict patient outcome and refine the standard GAP staging system. Multivariate cox regression analysis assessed the independence of the significant univariate predictors of patient outcome. RESULTS: The predominant parenchymal lung pattern was reticulation (16.6% ± 13.9), with pulmonary vessel percentage being the most predictive of worse patient outcome (p = 0.009). Higher SD, entropy and MPP, in addition to lower skewness and kurtosis at fine texture scale (SSF2), were the most significant predictors of worse outcome (p < 0.001). Multivariate cox regression analysis demonstrated that SD (SSF2) was the only independent predictor of survival (p < 0.001). Better patient outcome prediction was achieved after adding total vessel percentage and SD (SSF2) to the GAP staging system (p = 0.006). CONCLUSION: Filtration-histogram texture analysis can be an independent predictor of patient mortality in IPF patients. ADVANCES IN KNOWLEDGE: qCT analysis can help in risk stratifying IPF patients in addition to clinical markers

    Areas of normal pulmonary parenchyma on HRCT exhibit increased FDG PET signal in IPF patients

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    Purpose: Patients with idiopathic pulmonary fibrosis (IPF) show increased PET signal at sites of morphological abnormality on high-resolution computed tomography (HRCT). The purpose of this investigation was to investigate the PET signal at sites of normal-appearing lung on HRCT in IPF. Methods: Consecutive IPF patients (22 men, 3 women) were prospectively recruited. The patients underwent 18F-FDG PET/HRCT. The pulmonary imaging findings in the IPF patients were compared to the findings in a control population. Pulmonary uptake of 18F-FDG (mean SUV) was quantified at sites of morphologically normal parenchyma on HRCT. SUVs were also corrected for tissue fraction (TF). The mean SUV in IPF patients was compared with that in 25 controls (patients with lymphoma in remission or suspected paraneoplastic syndrome with normal PET/CT appearances). Results: The pulmonary SUV (mean ± SD) uncorrected for TF in the controls was 0.48 ± 0.14 and 0.78 ± 0.24 taken from normal lung regions in IPF patients (p < 0.001). The TF-corrected mean SUV in the controls was 2.24 ± 0.29 and 3.24 ± 0.84 in IPF patients (p < 0.001). Conclusion: IPF patients have increased pulmonary uptake of 18F-FDG on PET in areas of lung with a normal morphological appearance on HRCT. This may have implications for determining disease mechanisms and treatment monitoring. © 2013 The Author(s)

    Pulmonary 18F-FDG uptake helps refine current risk stratification in idiopathic pulmonary fibrosis (IPF).

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    PURPOSE: There is a lack of prognostic biomarkers in idiopathic pulmonary fibrosis (IPF) patients. The objective of this study is to investigate the potential of 18F-FDG-PET/ CT to predict mortality in IPF. METHODS: A total of 113 IPF patients (93 males, 20 females, mean age ± SD: 70 ± 9 years) were prospectively recruited for 18F-FDG-PET/CT. The overall maximum pulmonary uptake of 18F-FDG (SUVmax), the minimum pulmonary uptake or background lung activity (SUVmin), and target-to-background (SUVmax/ SUVmin) ratio (TBR) were quantified using routine region-of-interest analysis. Kaplan-Meier analysis was used to identify associations of PET measurements with mortality. We also compared PET associations with IPF mortality with the established GAP (gender age and physiology) scoring system. Cox analysis assessed the independence of the significant PET measurement(s) from GAP score. We investigated synergisms between pulmonary 18F-FDG-PET measurements and GAP score for risk stratification in IPF patients. RESULTS: During a mean follow-up of 29 months, there were 54 deaths. The mean TBR ± SD was 5.6 ± 2.7. Mortality was associated with high pulmonary TBR (p = 0.009), low forced vital capacity (FVC; p = 0.001), low transfer factor (TLCO; p  4.9 was 24 months. Combining PET data with GAP data ("PET modified GAP score") refined the ability to predict mortality. CONCLUSIONS: A high pulmonary TBR is independently associated with increased risk of mortality in IPF patients

    Regulatory Elements within the Prodomain of Falcipain-2, a Cysteine Protease of the Malaria Parasite Plasmodium falciparum

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    Falcipain-2, a papain family cysteine protease of the malaria parasite Plasmodium falciparum, plays a key role in parasite hydrolysis of hemoglobin and is a potential chemotherapeutic target. As with many proteases, falcipain-2 is synthesized as a zymogen, and the prodomain inhibits activity of the mature enzyme. To investigate the mechanism of regulation of falcipain-2 by its prodomain, we expressed constructs encoding different portions of the prodomain and tested their ability to inhibit recombinant mature falcipain-2. We identified a C-terminal segment (Leu155–Asp243) of the prodomain, including two motifs (ERFNIN and GNFD) that are conserved in cathepsin L sub-family papain family proteases, as the mediator of prodomain inhibitory activity. Circular dichroism analysis showed that the prodomain including the C-terminal segment, but not constructs lacking this segment, was rich in secondary structure, suggesting that the segment plays a crucial role in protein folding. The falcipain-2 prodomain also efficiently inhibited other papain family proteases, including cathepsin K, cathepsin L, cathepsin B, and cruzain, but it did not inhibit cathepsin C or tested proteases of other classes. A structural model of pro-falcipain-2 was constructed by homology modeling based on crystallographic structures of mature falcipain-2, procathepsin K, procathepsin L, and procaricain, offering insights into the nature of the interaction between the prodomain and mature domain of falcipain-2 as well as into the broad specificity of inhibitory activity of the falcipain-2 prodomain

    Variability in practices for drinking water vaccination of meat chickens against infectious laryngotracheitis

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    Context: Drinking water vaccination of young meat chickens with Infectious Laryngotracheitis (ILT) vaccine is problematic. Vaccine failure and adverse vaccine reactions are frequently reported. Variations in the technique of applying ILT vaccines by this mass vaccination method need to be understood to contribute to improving the success of vaccination. Aims: This study aimed to examine variations in the techniques of application of Infectious Laryngotracheitis vaccines via drinking water for young meat chickens. Methods: Drinking water vaccination techniques were observed and recorded across 52 broiler flocks during ILT outbreaks in three geographic areas of Australia. Descriptive statistics for all variables were computed and variations between integrator company procedures were statistically compared. Key results: Despite rigorous standard operating procedures, wide variations were observed in time of water deprivation prior to vaccination (3–15 min), time drinking water was stabilised prior to addition of vaccine and the type of stabiliser product used, time to activate the flock following filling of the water lines with vaccine (10–127 min), time for the vaccine to be consumed (36–226 min) and the volume of drinking water per bird used to provide the vaccine (11–48 mL/bird). Conclusions: Variation in vaccination technique can affect the success of drinking water vaccination against ILT in young meat chickens. Implications: Understanding the importance of the variable factors in vaccine application method can improve the success of water vaccination against ILT
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