scholarly journals The Effects of Host Age, Host Nuclear Background and Temperature on Phenotypic Effects of the Virulent Wolbachia Strain popcorn in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 164 (3) ◽  
pp. 1027-1034
Author(s):  
K Tracy Reynolds ◽  
Linda J Thomson ◽  
Ary A Hoffmann

Abstract Because of their obligate endosymbiotic nature, Wolbachia strains by necessity are defined by their phenotypic effects upon their host. Nevertheless, studies on the influence of host background and environmental conditions upon the manifestation of Wolbachia effects are relatively uncommon. Here we examine the behavior of the overreplicating Wolbachia strain popcorn in four different Drosophila melanogaster backgrounds at two temperatures. Unlike other strains of Wolbachia in Drosophila, popcorn has a major fitness impact upon its hosts. The rapid proliferation of popcorn causes cells to rupture, resulting in the premature death of adult hosts. Apart from this effect, we found that popcorn delayed development time, and host background influenced both this trait and the rate of mortality associated with infection. Temperature influenced the impact of popcorn upon host mortality, with no reduction in life span occurring in flies reared at 19°. No effect upon fecundity was found. Contrary to earlier reports, popcorn induced high levels of incompatibility when young males were used in tests, and CI levels declined rapidly with male age. The population dynamics of popcorn-type infections will therefore depend on environmental temperature, host background, and the age structure of the population.


BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e042140
Author(s):  
Vanessa J Apea ◽  
Yize I Wan ◽  
Rageshri Dhairyawan ◽  
Zudin A Puthucheary ◽  
Rupert M Pearse ◽  
...  

ObjectiveTo describe outcomes within different ethnic groups of a cohort of hospitalised patients with confirmed COVID-19 infection. To quantify and describe the impact of a number of prognostic factors, including frailty and inflammatory markers.SettingFive acute National Health Service Hospitals in east London.DesignProspectively defined observational study using registry data.Participants1737 patients aged 16 years or over admitted to hospital with confirmed COVID-19 infection between 1 January and 13 May 2020.Main outcome measuresThe primary outcome was 30-day mortality from time of first hospital admission with COVID-19 diagnosis during or prior to admission. Secondary outcomes were 90-day mortality, intensive care unit (ICU) admission, ICU and hospital length of stay and type and duration of organ support. Multivariable survival analyses were adjusted for potential confounders.Results1737 were included in our analysis of whom 511 had died by day 30 (29%). 538 (31%) were from Asian, 340 (20%) black and 707 (40%) white backgrounds. Compared with white patients, those from minority ethnic backgrounds were younger, with differing comorbidity profiles and less frailty. Asian and black patients were more likely to be admitted to ICU and to receive invasive ventilation (OR 1.54, (95% CI 1.06 to 2.23); p=0.023 and OR 1.80 (95% CI 1.20 to 2.71); p=0.005, respectively). After adjustment for age and sex, patients from Asian (HR 1.49 (95% CI 1.19 to 1.86); p<0.001) and black (HR 1.30 (95% CI 1.02 to 1.65); p=0.036) backgrounds were more likely to die. These findings persisted across a range of risk factor-adjusted analyses accounting for major comorbidities, obesity, smoking, frailty and ABO blood group.ConclusionsPatients from Asian and black backgrounds had higher mortality from COVID-19 infection despite controlling for all previously identified confounders and frailty. Higher rates of invasive ventilation indicate greater acute disease severity. Our analyses suggest that patients of Asian and black backgrounds suffered disproportionate rates of premature death from COVID-19.



2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sidra Perveen ◽  
Shalu Kumari ◽  
Himali Raj ◽  
Shahla Yasmin

Abstract Background Fluoride may induce oxidative stress and apoptosis. It may also lead to neurobehavioural defects including neuromuscular damage. The present study aimed to explore the effects of sub lethal concentrations of sodium fluoride (NaF) on the lifespan and climbing ability of Drosophila melanogaster. In total, 0.6 mg/L and 0.8 mg/L of NaF were selected as sublethal concentrations of NaF for the study. Lifespan was measured and climbing activity assay was performed. Results The study showed significant decrease in lifespan of flies treated with fluoride. With increasing age, significant reduction in climbing activity was observed in flies treated with sodium fluoride as compared to normal (control) flies. Flies treated with tulsi (Ocimum sanctum) and NaF showed increase in lifespan and climbing activity as compared to those treated with NaF only. Lipid peroxidation assay showed significant increase in malondialdehyde (MDA) values in the flies treated with NaF as compared to control. The MDA values decreased significantly in flies treated with tulsi mixed with NaF. Conclusions The results indicate that exposure to sub lethal concentration of NaF may cause oxidative stress and affect the lifespan and climbing activity of D. melanogaster. Tulsi extract may help in reducing the impact of oxidative stress and toxicity caused by NaF.





2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yann Combret ◽  
Guillaume Prieur ◽  
Roger Hilfiker ◽  
Francis-Edouard Gravier ◽  
Pauline Smondack ◽  
...  

Abstract Background Little interest has been paid to expiratory muscle strength, and the impact of expiratory muscle weakness on critical outcomes is not known. Very few studies assessed the relationship between maximal expiratory pressure (MEP) and critical outcomes. The aim of this study was to investigate the relationship between MEP and critical outcomes. Methods This work was a secondary analysis of a prospective, observational study of adult patients who required mechanical ventilation for ≥ 24 h in an 18-bed ICU. MEP was assessed before extubation after a successful, spontaneous breathing trial. The relationships between MEP and extubation failure, and short-term (30 days) mortality, were investigated. Univariate logistic regressions were computed to investigate the relationship between MEP values and critical outcomes. Two multivariate analyses, with and without maximal inspiratory pressure (MIP), both adjusted using principal component analysis, were undertaken. Unadjusted and adjusted ROC curves were computed to compare the respective ability of MEP, MIP and the combination of both measures to discriminate patients with and without extubation failure or premature death. Results One hundred and twenty-four patients were included. Median age was 66 years (IQR 18) and median mechanical ventilation duration was 7 days (IQR 6). Extubation failure rate was 15% (18/124 patients) and the rate for 30-day mortality was 11% (14/124 patient). Higher MEP values were significantly associated with a lower risk of extubation failure in the univariate analysis [OR 0.96 95% CI (0.93–0.98)], but not with short-term mortality. MEP was independently linked with extubation failure when MIP was not included in the multivariate model, but not when it was included, despite limited collinearity between these variables. This study was not able to differentiate the respective abilities of MEP, MIP, and their combination to discriminate patients with extubation failure or premature death (adjusted AUC for the combination of MEP and MIP: 0.825 and 0.650 for extubation failure and premature death, respectively). Conclusions MEP is related to extubation failure. But, the results did not support its use as a substitute for MIP, since the relationship between MEP and critical outcomes was no longer significant when MIP was included. The use of MIP and MEP measurements combined did not reach higher discriminative capacities for critical outcomes that MEP or MIP alone. Trial Registration This study was retrospectively registered at https://clinicaltrials.gov/ct2/show/NCT02363231?cond=NCT02363231&draw=2&rank=1 (NCT02363231) in 13 February 2015



2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 411-411
Author(s):  
Michelle Zechner ◽  
Ellen Anderson ◽  
Kenneth Gill

Abstract People with serious mental illness (SMI) are more likely to experience chronic health conditions at younger ages, which increases the risk of premature death. Co-morbid health conditions and risk for premature death are well-studied in the population, however less is understood about the impact of aging and SMI on functional ability. Research suggests that the population walk less and may have lower fitness levels than other populations (Gill et al., 2016). Specific data exploring functional age of people with SMI is sparse. The authors compared published standardized geriatric functional fitness values for people over 65 to baseline values of a community sample of people living with SMI who participated in a community health promotion intervention. The average age of the sample was 50 (SD=11). Three physical functioning measures were used in the comparison to measure physical functioning; the Sit to Stand Test, 6 Minute Walk, and Single Legged Stance. Results indicated significant differences in mean physical functioning values between the sample and standardized geriatric values. The sample performed at levels 20-30 years older than their chronological age. This finding suggests that mental health and aging services may need to adjust interventions, services and methods to improve physical functioning in middle-aged and older adults living with SMI. Premature functional decline impacts community living skills, independent living, housing choice, vocational options, and may impede personal goal attainment. Recommendations for interventions will be offered, as will suggestions for policies targeting services that cross aging and mental health silos.



2018 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Pieter A. Arnold ◽  
Samantha C. Levin ◽  
Aleksej L. Stevanovic ◽  
Karyn N. Johnson


2018 ◽  
Vol 63 (2) ◽  
pp. e01896-18 ◽  
Author(s):  
Sebastian Wurster ◽  
Russell E. Lewis ◽  
Nathaniel D. Albert ◽  
Dimitrios P. Kontoyiannis

ABSTRACT Breakthrough mucormycosis in patients receiving isavuconazole prophylaxis or therapy has been reported. We compared the impact of isavuconazole and voriconazole exposure on the virulence of clinical isolates of Aspergillus fumigatus and different Mucorales species in a Drosophila melanogaster infection model. In contrast to A. fumigatus, a hypervirulent phenotype was found in all tested Mucorales upon preexposure to either voriconazole or isavuconazole. These findings may contribute to the explanation of breakthrough mucormycosis in isavuconazole-treated patients.



2009 ◽  
Vol 11 (12) ◽  
pp. 791-798 ◽  
Author(s):  
Katie McLellan ◽  
Jerrold S. Petrofsky ◽  
Grenith Zimmerman ◽  
Everett Lohman ◽  
Michelle Prowse ◽  
...  


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4155 ◽  
Author(s):  
Pedro Cumino ◽  
Wellington Lobato Junior ◽  
Thais Tavares ◽  
Hugo Santos ◽  
Denis Rosário ◽  
...  

Collaboration between multiple Unmanned Aerial Vehicles (UAVs) to set up a Flying Ad Hoc Network (FANET) is a growing trend since future applications claim for more autonomous and rapid deployable systems. The user experience on watching videos transmitted over FANETs should always be satisfactory even under influence of topology changes caused by the energy consumption of UAVs. In addition, the FANET must keep the UAVs cooperating as much as possible during a mission. However, one of the main challenges in FANET is how to mitigate the impact of limited energy resources of UAVs on the FANET operation in order to monitor the environment for a long period of time. In this sense, UAV replacement is required in order to avoid the premature death of nodes, network disconnections, route failures, void areas, and low-quality video transmissions. In addition, decision-making must take into account energy consumption associated with UAV movements, since they are generally quite energy-intensive. This article proposes a cooperative UAV scheme for enhancing video transmission and global energy efficiency called VOEI. The main goal of VOEI is to maintain the video with QoE support while supporting the nodes with a good connectivity quality level and flying for a long period of time. Based on an Software Defined Network (SDN) paradigm, the VOEI assumes the existence of a centrailized controller node to compute reliable and energy-efficiency routes, as well as detects the appropriate moment for UAV replacement by considering global FANET context information to provide energy-efficiency operations. Based on simulation results, we conclude that VOEI can effectively mitigate the energy challenges of FANET, since it provides energy-efficiency operations, avoiding network death, route failure, and void area, as well as network partitioning compared to state-of-the-art algorithm. In addition, VOEI delivers videos with suitable Quality of Experience (QoE) to end-users at any time, which is not achieved by the state-of-the-art algorithm.



2017 ◽  
Vol 38 (5) ◽  
pp. 3095 ◽  
Author(s):  
Ana Maria Groehs Goldberg ◽  
Marisa Cardoso ◽  
Mari Lourdes Bernardi ◽  
Ivo Wentz ◽  
Fernando Pandolfo Bortolozzo

The aim of this study was to verify the influence of the degree of bacterial contamination of boar ejaculate and semen extender on the quality of semen doses. The experiment was conducted in four boar studs, from which raw semen and two semen doses from each ejaculate were collected to evaluate the number of colony-forming units (CFU), pH, sperm morphology and motility. Extender samples were also evaluated for CFU. Ejaculates that had higher levels of contamination ( > 220 CFU mL-1) resulted in semen doses with a greater degree of bacterial contamination but with no reduction in motility or alteration in pH. When the semen doses were classified according to the degree of contamination of the extender, a decrease in motility was observed after 108 and 168 h of storage (P < 0.05) in the group whose extender had ? 14,000 CFU mL-1 versus the group whose extender had ? 330 CFU mL-1. The pH remained stable during 168 h of storage in semen doses with extender that had lower contamination levels, but decreased from 7.2 to 6.0 between 24 and 168 h of storage (P < 0.05) in the group with extender that had higher levels of contamination. A higher number of abnormal acrosomes (P < 0.05) were observed after 168 h of storage in the semen doses whose extender was highly contaminated. The production of semen doses with low bacterial contamination and high sperm cell viability will only be possible with a strict hygienic control in semen processing, primarily with respect to the extender, combined with minimal contamination during collection.



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