29 research outputs found
Wolbachia strain wAlbB shows favourable characteristics for dengue control use in Aedes aegypti from Burkina Faso
Get PDFDengue represents an increasing public health burden worldwide. In Africa, underreporting and misdiagnosis often mask its true epidemiology, and dengue is likely to be both more widespread than reported data suggest and increasing in incidence and distribution. Wolbachia-based dengue control is underway in Asia and the Americas but has not to date been deployed in Africa. Due to the genetic heterogeneity of African Aedes aegypti populations and the complexity of the host-symbiont interactions, characterization of key parameters of Wolbachia-carrying mosquitoes is paramount for determining the potential of the system as a control tool for dengue in Africa. The wAlbB Wolbachia strain was stably introduced into an African Ae. aegypti population by introgression, and showed high intracellular density in whole bodies and different mosquito tissues; high intracellular density was also maintained following larval rearing at high temperatures. No effect on the adult lifespan induced by Wolbachia presence was detected. Moreover, the ability of this strain to strongly inhibit DENV-2 dissemination and transmission in the host was also demonstrated in the African background. Our findings suggest the potential of harnessing Wolbachia for dengue control for African populations of Ae. aegypti
High temperature cycles result in maternal transmission and dengue infection differences between Wolbachia strains in Aedes aegypti
Get PDFEnvironmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist, and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity, and dengue inhibition capacity were observed for wMel. In contrast, wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures
Total Internal Reflection Fluorescence Microscopy in Cell Biology
Full text linkPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72779/1/j.1600-0854.2001.21104.x.pd
Painting the Body: Feminist Musings on Visual Autographies
Get PDFIn this paper I look at autographical depictions of the body in the work of Mato Ioannidou, a Greek woman artist, who participated in a wider narrative-based project on visual and textual entanglements between life and art. The paper unfolds in three parts: first, I give an overview of Ioannidou’s artwork, making connections with significant events in her life; then I discuss feminist theorizations of embodiment and visual auto/biography; and finally I draw on insights from Spinozist feminist philosophers to discuss the artist’s portrayal of women’s bodies in three cycles of her work. What I argue is that the body becomes a centerpiece in the attempt to perceive connections between life and art through expressionism rather than representation
Design analysis and circuit topology optimization for programmable magnetic neurostimulator
No full textTranscranial magnetic stimulation (TMS) is a form of non-invasive brain stimulation commonly used to modulate neural activity. Despite three decades of examination, the generation of flexible magnetic pulses is still a challenging technical question. It has been revealed that the characteristics of pulses influence the bio-physiology of neuromodulation. In this study, a second-generation programmable TMS (xTMS) equipment with advanced stimulus shaping is introduced that uses cascaded H-bridge inverters and a phase-shifted pulse-width modulation (PWM). A low-pass RC filter model is used to estimate stimulated neural behavior, which helps to design the magnetic pulse generator, according to neural dynamics. The proposed device can generate highly adjustable magnetic pulses, in terms of waveform, polarity and pattern. We present experimental measurements of different stimuli waveforms, such as monophasic, biphasic and polyphasic shapes with peak coil current and the delivered energy of up to 6 kA and 250 J, respectively. The modular and scalable design idea presented here is a potential solution for generating arbitrary and highly customizable magnetic pulses and transferring repetitive paradigms
Energy conversion within current sheets in the Earth's quasi-parallel magnetosheath
No full textShock waves in collisionless plasmas rely on kinetic processes to convert the primary incident bulk flow energy into thermal energy. That conversion is initiated within a thin transition layer but may continue well into the downstream region. At the Earth's bow shock, the region downstream of shock locations where the interplanetary magnetic field is nearly parallel to the shock normal is highly turbulent. We study the distribution of thin current events in this magnetosheath. Quantification of the energy dissipation rate made by the Magnetospheric Multiscale spacecraft shows that these isolated intense currents are distributed uniformly throughout the magnetosheath and convert a significant fraction (5%–11%) of the energy flux incident at the bow shock
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Coronary artery calcifications in the long-term follow-up of Kawasaki disease
No full textTo determine if detection of coronary artery calcifications in patients with Kawasaki disease may serve as a noninvasive predictor of future coronary artery events.
A prospective, cohort pilot study that included 18 patients with Kawasaki disease >1 year from the acute disease was performed including 9 patients with coronary abnormalities during the acute illness (Group 1) and 9 without coronary abnormalities (Group 2). Patients were classified by echocardiography as having none, resolved, or residual coronary artery abnormalities. Electron beam computed tomography (EBCT) scans were completed using the Agatson coronary calcium scoring system. Intermediate follow-up was performed 2.5 years after EBCT to determine if clinically significant coronary artery events (myocardial infarction or sudden death) had occurred.
Late echocardiographic abnormalities corresponded with the early echocardiographic abnormalities in 5 of 9 patients (
P = .029) in Group 1. The late echocardiographic abnormalities significantly correlated with detection of calcifications by EBCT in 4 of 5 patients (95% CI 28%-99%). One patient with residual coronary abnormalities and coronary artery calcifications with the highest calcium score subsequently had a sudden death. Detection of coronary artery calcifications may be predictive of sudden death (
P = .056). No residual echocardiographic abnormalities, coronary artery calcifications, or coronary artery events occurred in Group 2 patients.
Patients with Kawasaki disease with residual coronary abnormalities show EBCT evidence of coronary artery calcifications. Detection of coronary artery calcifications may be useful for risk stratification in the long-term management of patients with Kawasaki disease
Production of Negative Hydrogen Ions Within the MMS Fast Plasma Investigation Due to Solar Wind Bombardment
No full textThe particle data delivered by the Fast Plasma Investigation instrument aboard National Aeronautics and Space Administration's Magnetospheric Multiscale (MMS) mission allow for exceptionally high-resolution examination of the electron and ion phase space in the near-Earth plasma environment. It is necessary to identify populations which originate from instrumental effects. Using Fast Plasma Investigation's Dual Electron Spectrometers, we isolate a high-energy (approximately kiloelectron volt) beam, present while the spacecraft are in the solar wind, which exhibits an azimuthal drift with period associated with the spacecraft spin. We show that this population is consistent with negative hydrogen ions H generated by a double charge exchange interaction between the incident solar wind H+ ions and the metallic surfaces within the instrument. This interaction is likely to occur at the deflector plates close to the instrument aperture. The H density is shown to be approximately 0.2-0.4% of the solar wind ion density, and the energy of the negative ion population is shown to be 70% of the incident solar wind energy. These negative ions may introduce errors in electron velocity moments on the order of 0.2-0.4% of the solar wind velocity and significantly higher errors in the electron temperature
