scholarly journals Longitudinal monitoring of individual infection progression in Drosophila melanogaster

2021 ◽  
Author(s):  
Bryan A. Ramirez-Corona ◽  
Anna C. Love ◽  
Srikiran Chandrasekaran ◽  
Jennifer A. Prescher ◽  
Zeba Wunderlich
Keyword(s):  
Drosophila Melanogaster ◽  
Time Scale ◽  
Photon Flux ◽  
High Temporal Resolution ◽  
Non Invasive ◽  
Pathogen Load ◽  
The Hours ◽  
Imaging Strategy ◽  
Over Time ◽  
Stochastic Responses

The innate immune system is critical for host survival of infection. Infection models in organisms like Drosophila melanogaster are key for understanding evolution and dynamics of innate immunity. However, current toolsets for fly infection studies are limited in their ability to resolve changes in pathogen load on the hours time-scale, along with stochastic responses to infection in individuals. Here we report a novel bioluminescent imaging strategy enabling non-invasive characterization of pathogen load over time. We demonstrate that photon flux from autobioluminescent reporter bacteria can be used to estimate pathogen count. Escherichia coli expressing the ilux operon were imaged in whole, living flies at relevant concentrations for immune study. Because animal sacrifice was not necessary to estimate pathogen load, stochastic responses to infection were characterized in individuals for the first time. The high temporal resolution of bioluminescence imaging also enabled visualization of the fine dynamics of microbial clearance on the hours time-scale. Overall, this non-invasive imaging strategy provides a simple and scalable platform to observe changes in pathogen load in vivo over time.

scholarly journals Kinetic sculpting of the seven stripes of the Drosophila even-skipped gene

2018 ◽  
Author(s):  
Augusto Berrocal ◽  
Nicholas Lammers ◽  
Hernan G. Garcia ◽  
Michael B. Eisen
Keyword(s):  
Drosophila Melanogaster ◽  
Pattern Formation ◽  
Transcriptional Activity ◽  
High Temporal Resolution ◽  
Burst Frequency ◽  
Computational Framework ◽  
Developmental Patterns ◽  
Transcriptional Dynamics ◽  
Transcriptional Bursting ◽  
Over Time

AbstractWe used live imaging to visualize the transcriptional dynamics of the Drosophila melanogaster even-skipped gene at single-cell and high temporal resolution as its seven stripe expression pattern forms, and developed tools to characterize and visualize how transcriptional bursting varies over time and space. We find that despite being created by the independent activity of five enhancers, even-skipped stripes are sculpted by the same kinetic phenomena: a coupled increase of burst frequency and amplitude. By tracking the position and activity of individual nuclei, we show that stripe movement is driven by the exchange of bursting nuclei from the posterior to anterior stripe flanks. Our work provides a conceptual, theoretical and computational framework for dissecting pattern formation in space and time, and reveals how the coordinated transcriptional activity of individual nuclei shape complex developmental patterns.

scholarly journals Kinetic sculpting of the seven stripes of the Drosophila even-skipped gene

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Augusto Berrocal ◽  
Nicholas C Lammers ◽  
Hernan G Garcia ◽  
Michael B Eisen
Keyword(s):  
Drosophila Melanogaster ◽  
Pattern Formation ◽  
Transcriptional Activity ◽  
High Temporal Resolution ◽  
Burst Frequency ◽  
Computational Framework ◽  
Developmental Patterns ◽  
Transcriptional Dynamics ◽  
Transcriptional Bursting ◽  
Over Time

We used live imaging to visualize the transcriptional dynamics of the Drosophila melanogaster even-skipped gene at single-cell and high temporal resolution as its seven stripe expression pattern forms, and developed tools to characterize and visualize how transcriptional bursting varies over time and space. We find that despite being created by the independent activity of five enhancers, even-skipped stripes are sculpted by the same kinetic phenomena: a coupled increase of burst frequency and amplitude. By tracking the position and activity of individual nuclei, we show that stripe movement is driven by the exchange of bursting nuclei from the posterior to anterior stripe flanks. Our work provides a conceptual, theoretical and computational framework for dissecting pattern formation in space and time, and reveals how the coordinated transcriptional activity of individual nuclei shape complex developmental patterns.

scholarly journals Prevalence and Photobiology of Photosynthetic Dinoflagellate Endosymbionts in the Nudibranch Berghia stephanieae

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2200
Author(s):  
Ruben X. G. Silva ◽  
Paulo Cartaxana ◽  
Ricardo Calado
Keyword(s):  
Food Deprivation ◽  
Photosynthetic Efficiency ◽  
Rapid Decrease ◽  
Complete Loss ◽  
Symbiotic Association ◽  
Non Invasive ◽  
Sea Slugs ◽  
Non Destructive ◽  
Over Time

Berghia stephanieae is a stenophagous sea slug that preys upon glass anemones, such as Exaiptasia diaphana. Glass anemones host photosynthetic dinoflagellate endosymbionts that sea slugs ingest when consuming E. diaphana. However, the prevalence of these photosynthetic dinoflagellate endosymbionts in sea slugs appears to be short-lived, particularly if B.stephanieae is deprived of prey that host these microalgae (e.g., during bleaching events impacting glass anemones). In the present study, we investigated this scenario, along with food deprivation, and validated the use of a non-invasive and non-destructive approach employing chlorophyll fluorescence as a proxy to monitor the persistence of the association between sea slugs and endosymbiotic photosynthetic dinoflagellates acquired through the consumption of glass anemones. Berghia stephanieae deprived of a trophic source hosting photosynthetic dinoflagellate endosymbionts (e.g., through food deprivation or by feeding on bleached E. diaphana) showed a rapid decrease in minimum fluorescence (Fo) and photosynthetic efficiency (Fv/Fm) when compared to sea slugs fed with symbiotic anemones. A complete loss of endosymbionts was observed within 8 days, confirming that no true symbiotic association was established. The present work opens a new window of opportunity to rapidly monitor in vivo and over time the prevalence of associations between sea slugs and photosynthetic dinoflagellate endosymbionts, particularly during bleaching events that prevent sea slugs from incorporating new microalgae through trophic interactions.

scholarly journals A potential new fabric evaluation approach by capturing brain perception under fabric contact pressure

2018 ◽  
Vol 89 (16) ◽  
pp. 3312-3325 ◽  
Author(s):  
Jie Yuan ◽  
Weidong Yu ◽  
Kemin Chen ◽  
Zhongwei Zhang ◽  
Yi Li ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Inhibitory Effect ◽  
High Temporal Resolution ◽  
Non Invasive ◽  
Evaluation Approach ◽  
Postcentral Gyrus ◽  
Comfort Perception ◽  
Peak Points ◽  
The Difference ◽  
Fabric Comfort

The problem of the transmission mechanism of textile perception and the barrier to express textile cognition directly are the two major issues in the field of textile evaluation. In this study, an advanced biomedical imaging technology, functional magnetic resonance imaging, which is non-invasive and has a high temporal resolution and spatial resolution, was utilized to describe the features of brain perception in the brain mask areas under increased fabric contact pressures, and thus it was attempted to provide a new approach to express fabric comfort perception. As a result, we found that when fabric contact pressure increased from 0.5 to 1.5 kPa, both maximum activation intensity T Z and activation proportion K of the peak points were transferred from the postcentral gyrus in the SI to the amygdala, and were negative activations. Therefore, we drew the conclusion that both a lower and a higher fabric contact pressure (about 1 kPa of proper comfort fabric pressure) would produce a brain signal inhibitory effect on the SI and amygdala. The difference was the fact that the inhibition role on the SI was more obvious under a lower pressure, while the inhibition role on the amygdala was more remarkable under a higher pressure, which meant that the SI, particularly the postcentral gyrus in the SI, was likely to play a significant role in surface tactile perception of fabrics, while the amygdala might be related to the fabric oppressing sensation.

scholarly journals ACL Graft Signal Characteristics Measured by Quantitative MRI Are Significantly Correlated with Patient Reported Outcomes Two-Years after Hamstring Autograft ACL Reconstruction

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0035
Author(s):  
Drew A. Lansdown ◽  
Weiyuan Xiao ◽  
Alan L. Zhang ◽  
Christina R. Allen ◽  
Brian T. Feeley ◽  
...  
Keyword(s):  
Acl Reconstruction ◽  
Quantitative Imaging ◽  
Relaxation Times ◽  
Tendon Graft ◽  
Hamstring Autograft ◽  
Acl Graft ◽  
Non Invasive ◽  
Patient Reported ◽  
Proteoglycan Content ◽  
Over Time

Objectives: Following surgical reconstruction of the anterior cruciate ligament (ACL), the tendon graft undergoes a remodeling process of ligamentization. Collagen within the ACL graft becomes organized along the long-axis of the ligament and the proteoglycan content increases. Quantitative imaging sequences, specifically T2 and T1rho, allow for a non-invasive assessment of collagen orientation and proteoglycan content, respectively. The purpose of this study was to investigate the longitudinal progression of T2 and T1rho relaxation times of the graft after ACL reconstruction and the relationship between these quantitative imaging markers and patient-reported outcome measures. We hypothesized that T2 and T1rho would decrease significantly over time, reflecting improved collagen organization and ncreased proteoglycan content, and that T2 and T1rho relaxation times would be inversely correlated with Knee Osteoarthritis Outcome Scores (KOOS). Methods: Thirty-two patients (mean age 29.4±8.2 years, 12 females) were followed prospectively after arthroscopic ACL reconstruction with hamstring autograft. Patients provided informed consent and all procedures were IRB-approved. Exclusion criteria included allograft reconstruction, other ligamentous injury, meniscal tear requiring repair, prior knee surgery, or history of arthritis. Post-operative MR imaging was obtained for 31 patients at 6 months, 30 patients at 12 months, 26 patients at 24 months, and 23 patients at 36 months after surgery. T2 and T1rho relaxation times were simultaneously acquired with a combined 3D sagittal sequence using a 3 T MR system (GE Healthcare) with a 1Tx/8Rx knee coil. The intra-articular ACL graft was identified on a fat-suppressed sagittal high-resolution 3D fast spin echo images and manually segmented. The T2 and T1rho relaxation times for the graft were recorded. Patients completed the KOOS at each imaging time point. Repeated measures analysis of variance (ANOVA) tests with Tukey corrections were used to compare T2 and T1rho relaxation times between time points. The relationship between KOOS and T2 and T1rho values at 2 years post-operative was investigated with Spearman’s rank correlation. Significance was defined as p<0.05. Results: The T2 relaxation times of the ACL graft were significantly higher at 6 months relative to 12 months (p<0.001), 24 months (p<0.001,) and 36 months (p<0.001) after ACL reconstruction, as well as significantly higher at 12 months relative to 36 months (p<0.001) (Figure 1A). The T1rho relaxation times of the ACL graft were significantly higher at 6 months relative to 12 months (p<0.001), 24 months (p<0.001), and 36 months (p<0.001) (Figure 1B). The two-year T2 relaxation times and T1rho relaxation times were significantly correlated with the KOOS Sports, Pain, Symptoms, and Activities of Daily Living sub-scores. Conclusion: We observed significant changes in the tendon graft over time following ACL reconstruction with hamstring autograft, reflecting a higher concentration of proteoglycan and more longitudinally-organized collagen structure over time. Improved collagen organization (lower T2 values) and increased proteoglycan content (lower T1rho values) were correlated with better outcomes based on KOOS scores. Quantitative T2 and T1rho relaxation times of ACL graft may offer a non-invasive method for monitoring graft maturation that correlates with patient-reported knee function after ACL reconstruction. [Figure: see text][Table: see text]

Intrasample variation and the effect of storage delay on faecal metabolite concentrations in the southern hairy-nosed wombat (Lasiorhinus latifrons)

2012 ◽  
Vol 34 (2) ◽  
pp. 217 ◽  
Author(s):  
Kristin A. Descovich ◽  
Allan T. Lisle ◽  
Stephen Johnston ◽  
Tamara Keeley ◽  
Clive J. C. Phillips
Keyword(s):  
Wild Animal ◽  
Initial Increase ◽  
Sample Storage ◽  
Metabolite Analysis ◽  
Adrenal Hormone ◽  
Non Invasive ◽  
Animal Populations ◽  
Metabolite Concentrations ◽  
Hormonal Fluctuations ◽  
Over Time

Faecal hormone metabolite analysis offers a non-invasive alternative to blood sampling that is particularly relevant to wild animal populations. It has been used for reproductive and adrenal hormone monitoring in captive wombats, but no information exists on its accuracy when sample storage is delayed or on whether variation exists within samples. This study aimed to quantify the effect of storage delay and intrasample variation on faecal metabolite concentrations of testosterone, progesterone and corticosterone in southern hairy-nosed wombats. For all metabolites, intrasample variance was 15% or less of total variance. Delays in storage significantly changed metabolite concentrations, with progesterone showing a progressive decrease over time (0–72 h: t24 = 2.14, P = 0.05), testosterone showing a significant increase after 6-h delay (0–6 h: t21 = 2.83, P = 0.01), and corticosterone showing an initial increase (0–6 h: t48 = 3.60, P = 0.001), followed by a reduction to original concentrations by 72 h (0–72 h: t48 = 0.91, P = 0.38). Although changes caused by storage delays may not obscure large hormonal fluctuations, this study outlines the importance of immediate storage and consistent sampling to allow the most accurate results to be obtained.

scholarly journals Patterns of Non-Invasive Ventilation in Amyotrophic Lateral Sclerosis

2018 ◽  
Vol 45 (4) ◽  
pp. 445-450
Author(s):  
Nevena Markovic ◽  
Marcus Povitz ◽  
Joanne Smith ◽  
David Leasa ◽  
Christen Shoesmith ◽  
...  
Keyword(s):  
Decision Making ◽  
Amyotrophic Lateral Sclerosis ◽  
End Of Life ◽  
Invasive Ventilation ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
End Of Life Decision ◽  
Life Decision ◽  
Lateral Sclerosis ◽  
Over Time

AbstractBackground: Non-invasive ventilation (NIV) improves quality of life and survival in patients with amyotrophic lateral sclerosis (ALS) and respiratory symptoms. Little is known about the patterns of NIV use over time and the impact of NIV on end-of-life decision-making in ALS. Objective: This study assessed the pattern of NIV use over the course of the disease and the timing of end-of-life discussions in people living with ALS. Method: A retrospective single-center cohort study was performed at London Health Sciences Centre. Daily NIV duration of use was evaluated at 3-month intervals. The timing of diagnosis, NIV initiation, discussions relating to do-not-attempt-resuscitation (DNAR) and death were examined. Results: In total, 48 patients were included in the analysis. Duration of NIV use increased over time, and tolerance to NIV was observed to be better than expected in patients with bulbar-onset ALS. There was a high degree of variability in the timing of end-of-life discussions in patients with ALS (356±451 days from diagnosis). In this cohort, there was a strong association between the timing of discussions regarding code status and establishment of a DNAR order (r2=0.93). Conclusion: This retrospective cohort study suggests that the use of NIV in ALS increases over time and that there remains a great deal of variability in the timing of end-of-life discussions in people living with ALS. Future prospective studies exploring the use NIV over the disease trajectory and how NIV affects end-of-life decision-making in people with ALS are needed.

scholarly journals How long do anti-predator interventions remain effective? Patterns, thresholds and uncertainty

2019 ◽  
Vol 6 (9) ◽  
pp. 190826 ◽  
Author(s):  
Igor Khorozyan ◽  
Matthias Waltert
Keyword(s):  
Systematic Review ◽  
Temporal Trend ◽  
Supplemental Feeding ◽  
Temporal Dimension ◽  
Trend Line ◽  
Know How ◽  
Non Invasive ◽  
Effective Interventions ◽  
Mammalian Predators ◽  
Over Time

Human–predator conflicts are globally widespread, and effective interventions are essential to protect human assets from predator attacks. As effectiveness also has a temporal dimension, it is of importance to know how long interventions remain most effective and to determine time thresholds at which effectiveness begins to decrease. To address this, we conducted a systematic review of the temporal changes in the effectiveness of non-invasive interventions against terrestrial mammalian predators, defining a temporal trend line of effectiveness for each published case. We found only 26 cases from 14 publications, mainly referring to electric fences ( n = 7 cases) and deterrents ( n = 7 cases). We found electric fences and calving control to remain highly effective for the longest time, reducing damage by 100% for periods between three months and 3 years. The effectiveness of acoustical and light deterrents as well as guarding animals eroded quite fast after one to five months. Supplemental feeding was found to be counter-productive by increasing damage over time instead of reducing it. We stress that it is vital to make monitoring a routine requirement for all intervention applications and suggest to standardize periods of time over which monitoring can produce meaningful and affordable information.

scholarly journals Trends in the Use and Outcomes of Mechanical Ventilation among Patients Hospitalized with Acute Exacerbations of COPD in Spain, 2001 to 2015

2019 ◽  
Vol 8 (10) ◽  
pp. 1621 ◽  
Author(s):  
de Miguel-Diez ◽  
Jiménez-García ◽  
Hernández-Barrera ◽  
Puente-Maestu ◽  
Girón-Matute ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Invasive Mechanical Ventilation ◽  
Ventilatory Support ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Acute Exacerbations ◽  
Discharge Database ◽  
Over Time

(1) Background: We examine trends (2001–2015) in the use of non-invasive ventilation (NIV) and invasive mechanical ventilation (IMV) among patients hospitalized for acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). (2) Methods: Observational retrospective epidemiological study, using the Spanish National Hospital Discharge Database. (3) Results: We included 1,431,935 hospitalizations (aged ≥40 years) with an AE-COPD. NIV use increased significantly, from 1.82% in 2001–2003 to 8.52% in 2013–2015, while IMV utilization decreased significantly, from 1.39% in 2001–2003 to 0.67% in 2013–2015. The use of NIV + invasive mechanical ventilation (IMV) rose significantly over time (from 0.17% to 0.42%). Despite the worsening of clinical profile of patients, length of stay decreased significantly over time in all types of ventilation. Patients who received only IMV had the highest in-hospital mortality (IHM) (32.63%). IHM decreased significantly in patients with NIV + IMV, but it remained stable in those receiving isolated NIV and isolated IMV. Factors associated with use of any type of ventilatory support included female sex, lower age, and higher comorbidity. (4) Conclusions: We found an increase in NIV use and a decline in IMV utilization to treat AE-COPD among hospitalized patients. The IHM decreased significantly over time in patients who received NIV + IMV, but it remained stable in patients who received NIV or IMV in isolation

Decisions and the Uncertainty of Behaviour

Behaviour ◽  
1973 ◽  
Vol 45 (1-2) ◽  
pp. 83-103 ◽  
Author(s):  
◽  
Marian Dawkins
Keyword(s):  
Time Scale ◽  
The Other ◽  
Drinking Behaviour ◽  
Temporal Patterning ◽  
Domestic Chicks ◽  
Decision Structure ◽  
Videotape Analysis ◽  
Behavioural Sequence ◽  
Different Parts ◽  
Over Time

AbstractBehaviour can be described in terms of its changing uncertainty or decision structure over time. Such a description is economical, maximally informative and may well be of importance neurophysiologically. We try to show that the methods which are normally used to detect temporal patterning between already recognized behavioural acts can also be used on a finer time scale to detect moment to moment patterns of posture within those acts. From such analyses, it is possible to calculate the 'decisioniness' or 'uncertainty' of different parts of the behavioural sequence. We illustrate this by an attempt to describe the decision structure of the drinking behaviour of domestic chicks, using frame by frame videotape analysis. For example, it appears that the first downstroke phase of each drink is more uncertain as to outcome than the other phases, suggesting that 'decisions' are taken during the downstroke. We end with an attempt to plot a continuous graph of behaviour uncertainty against time sampled at 50 msec intervals.

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