In eubacteria, the biosynthesis of queuine, a modified base found in the wobble position (#34) of tRNAs coding for Tyr, His, Asp, and Asn, occurs via a multistep pathway. One of the key enzymes in this pathway, tRNA-guanine transglycosylase (TGT), exchanges the genetically encoded guanine at position 34 with a queuine precursor, preQ1. Previous studies have identified a minimal positive RNA rec...

In an attempt to minimise the negative economic impacts of COVID-19 on vulnerable households South African government allocated R50 billion in additional social assistance spending. The cash transfer package included a temporary increase existing grants and introduced new “Covid grant.” We assess chosen compare it with initial proposal Child Support Grant (CSG). Coverage, cost welfare effects a...

Stopping power ratios sw,air for electron beams produced by the NOVAC7® IORT accelerator were calculated at different depths in water by the SPRRZnrc Monte Carlo code. As input for the SPRRZnrc code a phase-space data file obtained for any beam by the BEAMnrc code was used. The calculated stopping power ratios were compared with those recommended by the IAEA dosimetry protocols TRS-381 and TRS-...

The aim of this study was to assess the suitability of the Im'RT MatriXX 2D ion chamber array for performing verification measurements on the Varian Eclipse electron Monte Carlo (eMC) algorithm for a range of clinical energies (6, 12, and 20 MeV) on a Varian 2100iX linear accelerator. Firstly, the suitability of the MatriXX for measuring percentage depth doses (PDD) in water was assessed, inclu...

The aim of this work was to model the characteristics of a clinical proton spot scanning beam using Monte Carlo simulations with the code MCNP6. The proton beam was defined using parameters obtained from beam commissioning at the Skandion Clinic, Uppsala, Sweden. Simulations were evaluated against measurements for proton energies between 60 and 226 MeV with regard to range in water, lateral spo...

The specific design of the mobile dedicated intraoperative radiotherapy (IORT) accelerators and different electron beam collimation system can change the dosimetric characteristics of electron beam with respect to the conventional accelerators. The aim of this study is to measure and compare the dosimetric characteristics of electron beam produced by intraoperative and conventional radiotherapy...

Reef life: The Great Barrier Reef is widely known as one of the great wonders of the natural world, but it is exposed to a wide range of threats both from ocean warming and from land-use changes in Queensland. (Photo: LCDR Eric Johnson, NOAA Corps.) The Great Barrier Reef spans a length greater than Italy and thus counts as the largest structure created by living beings. It is a World Heritage ...

This paper evaluates the effect of alcohol access on drug-related crime using detailed information on county and state level changes in access laws in Texas between 1978 and 1996. After controlling for both county and year fixed effects, we find evidence that allowing local alcohol access decreases crimes associated with illicit drugs. We also find that prohibiting the sale of beer to persons u...