The Effect of Kelvin Effect on the Equilibrium Effective Radii and Hygroscopic Growth of Atmospheric Aerosols

In this paper we extracted microphysical properties of six types of atmospheric aerosols from Optical Properties of Aerosols and Clouds (OPAC) and numerically analyzed the analytical expressions for the changes in the equilibrium relative humidity (RH), effective radius, effective hygroscopic growth, the magnitudes and fractional changes in the effective radii  and the effective hygroscopic growth on the effects of surface tension (the Kelvin effect) on ambient atmospheric aerosols. The expressions were applied to two - one parameter models. We discovered from the analysis of the data extracted that, to the lowest order error, the change in the equilibrium RH, effective radii and effective hygroscopic growth depend on the compositions of the aerosols. From the two models used, we also discovered that the fractional changes in the ambient RH, effective radii and effective hygrosocopic growth, also depend on the aerosols compositions. Finally, we discovered that the magnitude of the Kelvin effect and its consequences on the atmospheric aerosols depend on the hygroscopicity of the aerosols. Keywords: Kelvin effect, effective radius, effective hygroscopic growth, atmospheric aerosols, ambient Relative Humidity

Photometric IGM tomography with Subaru/HSC: the large-scale structure of Lyα emitters and IGM transmission in the COSMOS field at z ∼ 5

We present a novel technique called “photometric IGM tomography” to map the intergalactic medium (IGM) at z ≃ 4.9 in the COSMOS field. It utilizes deep narrow-band (NB) imaging to photometrically detect faint Lyα forest transmission in background galaxies across the Subaru/Hyper-Suprime Cam (HSC)’s 1.8sq.deg field of view and locate Lyα emitters (LAEs) in the same cosmic volume. Using ultra-deep HSC images and Bayesian spectral energy distribution fitting, we measure the Lyα forest transmission at z ≃ 4.9 along a large number (140) of background galaxies selected from the DEIMOS10k spectroscopic catalogue at 4.98 < z < 5.89 and the SILVERRUSH LAEs at z ≃ 5.7. We photometrically measure the mean Lyα forest transmission and achieve a result consistent with previous measurements based on quasar spectra. We also measure the angular LAE-Lyα forest cross-correlation and Lyα forest auto-correlation functions and place an observational constraint on the large-scale fluctuations of the IGM around LAEs at z ≃ 4.9. Finally, we present the reconstructed 2D tomographic map of the IGM, co-spatial with the large-scale structure of LAEs, at a transverse resolution of 11h−1cMpc across 140h−1cMpc in the COSMOS field at z ≃ 4.9. We discuss the observational requirements and the potential applications of this new technique for understanding the sources of reionization, quasar radiative history, and galaxy-IGM correlations across z ∼ 3 − 6. Our results represent the first proof-of-concept of photometric IGM tomography, offering a new route to examining early galaxy evolution in the context of the large-scale cosmic web from the epoch of reionization to cosmic noon

Alarming rates of virological failure and HIV-1 drug resistance amongst adolescents living with perinatal HIV in both urban and rural settings: evidence from the EDCTP READY-study in Cameroon

Objectives: Adolescents living with perinatal HIV infection (ALPHI) experience persistently high mortality rates, particularly in resource-limited settings. It is therefore clinically important for us to understand the therapeutic response, acquired HIV drug resistance (HIVDR) and associated factors among ALPHI, according to geographical location. Methods: A study was conducted among consenting ALPHI in two urban and two rural health facilities in the Centre Region of Cameroon. World Health Organization (WHO) clinical staging, self-reported adherence, HIVDR early warning indicators (EWIs), immunological status (CD4 count) and plasma viral load (VL) were assessed. For those experiencing virological failure (VF, VL&nbsp;≥&nbsp;1000 copies/mL), HIVDR testing was performed and interpreted using the Stanford HIV Drug Resistance Database v.8.9-1. Results: Of the 270 participants, most were on nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (61.7% urban vs. 82.2% rural), and about one-third were poorly adherent (30.1% vs. 35.1%). Clinical failure rates (WHO-stage III/IV) in both settings were&nbsp;&lt;&nbsp;15%. In urban settings, the immunological failure (IF) rate (CD4 &nbsp;&lt;&nbsp;250 cells/μL) was 15.8%, statistically associated with late adolescence, female gender and poor adherence. The VF rate was 34.2%, statistically associated with poor adherence and NNRTI-based antiretroviral therapy. In the rural context, the IF rate was 26.9% and the VF rate was 52.7%, both statistically associated with advanced clinical stages. HIVDR rate was over 90% in both settings. EWIs were delayed drug pick-up, drug stock-outs and suboptimal viral suppression. Conclusions: Poor adherence, late adolescent age, female gender and advanced clinical staging worsen IF. The VF rate is high and consistent with the presence of HIVDR in both settings, driven by poor adherence, NNRTI-based regimen and advanced clinical staging

Treating the placenta to prevent adverse effects of gestational hypoxia on fetal brain development.

Some neuropsychiatric disease, including schizophrenia, may originate during prenatal development, following periods of gestational hypoxia and placental oxidative stress. Here we investigated if gestational hypoxia promotes damaging secretions from the placenta that affect fetal development and whether a mitochondria-targeted antioxidant MitoQ might prevent this. Gestational hypoxia caused low birth-weight and changes in young adult offspring brain, mimicking those in human neuropsychiatric disease. Exposure of cultured neurons to fetal plasma or to secretions from the placenta or from model trophoblast barriers that had been exposed to altered oxygenation caused similar morphological changes. The secretions and plasma contained altered microRNAs whose targets were linked with changes in gene expression in the fetal brain and with human schizophrenia loci. Molecular and morphological changes in vivo and in vitro were prevented by a single dose of MitoQ bound to nanoparticles, which were shown to localise and prevent oxidative stress in the placenta but not in the fetus. We suggest the possibility of developing preventative treatments that target the placenta and not the fetus to reduce risk of psychiatric disease in later life