The effects of surface structure mutations in <i>Arabidopsis thaliana</i> on the polarization of reflections from virus-infected leaves

<div><p>The way in which light is polarized when reflected from leaves can be affected by infection with plant viruses. This has the potential to influence viral transmission by insect vectors due to altered visual attractiveness of infected plants. The optical and topological properties of cuticular waxes and trichomes are important determinants of how light is polarized upon reflection. Changes in expression of genes involved in the formation of surface structures have also been reported following viral infection. This paper investigates the role of altered surface structures in virus-induced changes to polarization reflection from leaves. The percentage polarization of reflections from <i>Arabidopsis thaliana cer5</i>, <i>cer6</i> and <i>cer8</i> wax synthesis mutants, and the <i>gl1</i> leaf hair mutant, was compared to those from wild-type (WT) leaves. The <i>cer5</i> mutant leaves were less polarizing than WT on the adaxial and abaxial surfaces; <i>gl1</i> leaves were more polarizing than WT on the adaxial surfaces. The <i>cer6</i> and <i>cer8</i> mutations did not significantly affect polarization reflection. The impacts of <i>Turnip vein clearing virus</i> (TVCV) infection on the polarization of reflected light were significantly affected by <i>cer5</i> mutation, with the reflections from <i>cer5</i> mutants being higher than those from WT leaves, suggesting that changes in <i>CER5</i> expression following infection could influence the polarization of the reflections. There was, however, no significant effect of the <i>gl1</i> mutation on polarization following TVCV infection. The <i>cer5</i> and <i>gl1</i> mutations did not affect the changes in polarization following <i>Cucumber mosaic virus</i> (CMV) infection. The accumulation of TVCV and CMV did not differ significantly between mutant and WT leaves, suggesting that altered expression of surface structure genes does not significantly affect viral titres, raising the possibility that if such regulatory changes have any adaptive value it may possibly be through impacts on viral transmission.</p></div

Genomic Analysis of Companion Rabbit Staphylococcus aureus.

In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections.This project was supported by internal funding from the School of Biological, Biomedical and Environmental Sciences, University of Hull (GKP), a Medical Research Council (MRC) Partnership Grant (G1001787/1) (MAH and JP), and the Wellcome Trust, Grant number 098051 (JP).This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.015145

Ionization and Ionization-Excitation of Helium to the n=1-4 States of He⁺ by Electron Impact

We present experimental and theoretical results for the electron-impact-induced ionization of ground-state helium atoms. Using a high-sensitivity toroidal electron spectrometer, we measured cross-section ratios for transitions leading to the first three excited states of the residual helium ion relative to the transition leaving the ion in the ground state. Measurements were performed for both symmetric- and asymmetric-energy-sharing kinematics. By presenting results as a ratio, a direct comparison can be made between theoretical and experimental predictions without recourse to normalization. The experimental data are compared to theoretical predictions employing various first-order models and a second-order hybrid distorted-wave + convergent R matrix with pseudostates (close-coupling) approach. All the first-order models fail in predicting even the approximate size of the cross-section ratios. The second-order calculations are found to describe the experimental data for asymmetric-energy-sharing with reasonable fidelity, although significant disparities are evident for the symmetric-energy-sharing cases. These comparisons demonstrate the need for further theoretical developments, in which all four charged particles are treated on an equal footing

Early and Highly Suppressive ART are Main Factors Associated with Low Viral Reservoir in European Perinatally HIV Infected Children

Abstract BACKGROUND: Future strategies aiming to achieve HIV-1 remission are likely to target individuals with small reservoir size. SETTING: We retrospectively investigated factors associated with HIV-1 DNA levels in European, perinatally HIV-infected children starting ART <6 months of age. METHODS: Total HIV-1 DNA was measured from 51 long-term suppressed children 6.3 years (median) after initial viral suppression. Factors associated with log10 total HIV-1 DNA were analyzed using linear regression. RESULTS: At ART initiation, children were aged median [IQR] 2.3 [1.2,4.1] months, CD4% 37 [24,45] %, CD8% 28 [18,36] %, log10 plasma viral load (VL) 5.4 [4.4,5.9] copies/ml. Time to viral suppression was 7.98 [4.6,19.3] months. Following suppression, 13 (25%) children had suboptimal response [ 652 consecutive VL50-400 followed by VL<50] and/or experienced periods of virological failure [ 652 consecutive VL 65400 followed by VL<50]. Median total HIV-1 DNA was 43 [6,195] copies/10 PBMC.Younger age at therapy initiation was associated with lower total HIV-1 DNA (adjusted coefficient [AC] 0.12 per month older, p=0.0091), with a month increase in age at ART start being associated with a 13% increase in HIV DNA. Similarly, a higher proportion of time spent virally suppressed (AC 0.10 per 10% higher, p=0.0022) and absence of viral failure/suboptimal response (AC 0.34 for those with fail/ suboptimal response, p=0.0483) were associated with lower total HIV-1 DNA. CONCLUSION: Early ART initiation and a higher proportion of time suppressed are linked with lower total HIV-1 DNA. Early ART start and improving adherence in perinatally HIV-1 infected children minimize the size of viral reservoir.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal

Cancer risk management strategies and perceptions of unaffected women 5 years after predictive genetic testing for BRCA1/2 mutations

In a French national cohort of unaffected females carriers/non-carriers of a BRCA1/2 mutation, long-term preventive strategies and breast/ovarian cancer risk perceptions were followed up to 5 years after test result disclosure, using self-administered questionnaires. Response rate was 74%. Carriers (N=101) were younger (average age±SD=37±10) than non-carriers (N=145; 42±12). There were four management strategies that comprised 88% of the decisions made by the unaffected carriers: 50% opted for breast surveillance alone, based on either magnetic resonance imaging (MRI) and other imaging (31%) or mammography alone (19%); 38% opted for either risk reducing salpingo-oophorectomy (RRSO) and breast surveillance, based on MRI and other imaging (28%) or mammography alone (10%). The other three strategies were: risk reducing mastectomy (RRM) and RRSO (5%), RRM alone (2%) and neither RRM/RRSO nor surveillance (6%). The results obtained for various age groups are presented here. Non-carriers often opted for screening despite their low cancer risk. Result disclosure increased carriers' short-term high breast/ovarian cancer risk perceptions (P⩽0.02) and decreased non-carriers' short- and long-term perceptions (P<0.001). During follow-up, high breast cancer risk perceptions increased with time among those who had no RRM and decreased in the opposite case; high ovarian cancer risk perceptions increased further with time among those who had no RRSO and decreased in the opposite case; RRSO did not affect breast cancer risk perceptions. Informed decision-making involves letting women know whether opting for RRSO and breast MRI surveillance is as effective in terms of survival as RRM and RRSO