Bulk properties of the van der Waals hard ferromagnet VI3

We present comprehensive measurements of the structural, magnetic, and electronic properties of layered van der Waals ferromagnet VI3 down to low temperatures. Despite belonging to a well-studied family of transition-metal trihalides, this material has received very little attention. We outline, from high-resolution powder x-ray diffraction measurements, a corrected room-temperature crystal structure to that previously proposed and uncover a structural transition at 79 K, also seen in the heat capacity. Magnetization measurements confirm VI3 to be a hard ferromagnet (9.1 kOe coercive field at 2 K) with a high degree of anisotropy, and the pressure dependence of the magnetic properties provide evidence for the two-dimensional nature of the magnetic order. Optical and electrical transport measurements show this material to be an insulator with an optical band gap of 0.67 eV - the previous theoretical predictions of d-band metallicity then lead us to believe VI3 to be a correlated Mott insulator. Our latest band-structure calculations support this picture and show good agreement with the experimental data. We suggest VI3 to host great potential in the thriving field of low-dimensional magnetism and functional materials, together with opportunities to study and make use of low-dimensional Mott physics

Validity of a reported history of chickenpox in targeting varicella vaccination at susceptible adolescents in England

Introduction: In the UK, primary varicella is usually a mild infection in children, but can cause serious illness in susceptible pregnant women and adults. The UK Joint Committee on Vaccination and Immunisation is considering an adolescent varicella vaccination programme. Cost-effectiveness depends upon identifying susceptibles and minimising vaccine wastage, and chickenpox history is one method to screen for eligibility. To inform this approach, we estimated the proportion of adolescents with varicella antibodies by reported chickenpox history. Methods: Recruitment occurred through secondary schools in England from February to September 2012. Parents were asked about their child's history of chickenpox, explicitly setting the context in terms of the implications for vaccination. 247 adolescents, whose parents reported positive (120), negative (77) or uncertain (50) chickenpox history provided oral fluid for varicella zoster virus-specific immunoglobulin-G (VZV-IgG) testing. Results: 109 (90.8% [85.6-96.0%]) adolescents with a positive chickenpox history, 52 (67.5% [57.0-78.1%]) with a negative history and 42 (84.0% [73.7-94.3%]) with an uncertain history had VZV-IgG suggesting prior infection. Combining negative and uncertain histories, 74% had VZV-IgG (best-case). When discounting low total-IgG samples and counting equivocals as positive (worst-case), 84% had VZV-IgG. We also modelled outcomes by varying the negative predictive value (NPV) for the antibody assay, and found 74-87% under the best-case and 84-92% under the worst-case scenario would receive vaccine unnecessarily as NPV falls to 50%. Conclusion: Reported chickenpox history discriminates between varicella immunity and susceptibility in adolescents, but significant vaccine wastage would occur if this approach alone were used to determine vaccine eligibility. A small but important proportion of those with positive chickenpox history would remain susceptible. These data are needed to determine whether reported history, with or without oral fluid testing in those with negative and uncertain history, is sufficiently discriminatory to underpin a cost-effective adolescent varicella vaccination programme. © 2013 The Authors

Transcriptomic Analysis of the Salivary Glands of an Invasive Whitefly

<div><h3>Background</h3><p>Some species of the whitefly <em>Bemisia tabaci</em> complex cause tremendous losses to crops worldwide through feeding directly and virus transmission indirectly. The primary salivary glands of whiteflies are critical for their feeding and virus transmission. However, partly due to their tiny size, research on whitefly salivary glands is limited and our knowledge on these glands is scarce.</p> <h3>Methodology/Principal Findings</h3><p>We sequenced the transcriptome of the primary salivary glands of the Mediterranean species of <em>B. tabaci</em> complex using an effective cDNA amplification method in combination with short read sequencing (Illumina). In a single run, we obtained 13,615 unigenes. The quantity of the unigenes obtained from the salivary glands of the whitefly is at least four folds of the salivary gland genes from other plant-sucking insects. To reveal the functions of the primary glands, sequence similarity search and comparisons with the whole transcriptome of the whitefly were performed. The results demonstrated that the genes related to metabolism and transport were significantly enriched in the primary salivary glands. Furthermore, we found that a number of highly expressed genes in the salivary glands might be involved in secretory protein processing, secretion and virus transmission. To identify potential proteins of whitefly saliva, the translated unigenes were put into secretory protein prediction. Finally, 295 genes were predicted to encode secretory proteins and some of them might play important roles in whitefly feeding.</p> <h3>Conclusions/Significance:</h3><p>The combined method of cDNA amplification, Illumina sequencing and <em>de novo</em> assembly is suitable for transcriptomic analysis of tiny organs in insects. Through analysis of the transcriptome, genomic features of the primary salivary glands were dissected and biologically important proteins, especially secreted proteins, were predicted. Our findings provide substantial sequence information for the primary salivary glands of whiteflies and will be the basis for future studies on whitefly-plant interactions and virus transmission.</p> </div

Protein disulphide isomerase-assisted functionalization of proteinaceous substrates

Protein disulphide isomerase (PDI) is an enzyme that catalyzes thiol-disulphide exchange reactions among a broad spectrum of substrates, including proteins and low-molecular thiols and disulphides. As the first protein-folding catalyst reported, the study of PDI has mainly involved the correct folding of several cysteine-containing proteins. Its application on the functionalization of protein-based materials has not been extensively reported. Herein, we review the applications of PDI on the modification of proteinaceous substrates and discuss its future potential. The mechanism involved in PDI functionalization of fibrous protein substrates is discussed in detail. These approaches allow innovative applications in textile dyeing and finishing, medical textiles, controlled drug delivery systems and hair or skin care products.We thank to FCT 'Fundacao para a Ciencia e Tecnologia' (scholarship SFRH/BD/38363/2007) for providing Margarida Fernandes the grant for PhD studies

The role of teacher behavior management in the development of disruptive behaviors: an intervention study with the good behavior game

Abstract The role of teacher behavior management for children’s disruptive behavior development (hyperactive and oppositional behavior) was investigated using a universal classroom preventive intervention study. Five-hundred seventy children were followed from second to third grade of elementary school. Observations of teacher behavior management and children’s on-task and off-task classroom behavior and peer reports of hyperactive and oppositional behavior were available. Results showed that the reduced use of negative remarks of intervention teachers predicted children’s increase in on-task behavior and decrease in talking-out behavior. These improved children’s classroom behaviors in turn mediated the impact of the intervention on the development of hyperactive and oppositional behavior over the studied period. These results were similar for girls and boys. The results underscore the role of teachers’ classroom management strategies in improving children’s classroom behavior, which, in turn is an important component in the reduction of disruptive behavior development

Short-selling ban and cross-sectoral contagion: Evidence from the UK

The UK?s Financial Services Authority introduced a ban on the short-selling of specified financial-sector stocks in September 2008. The regulator?s stated objectives were to protect market quality, stabilise the market for financial-sector stocks, and prevent cross-sectoral contagion. We analyse the price, market quality and contagion effects following the imposition of the short-selling ban, and its removal in January 2009. We report evidence consistent with a short-lived overpricing (underpricing) effect immediately after the ban was imposed (lifted). There is evidence of deterioration in market quality while the ban was in force. There is evidence of cross-sectoral contagion from the financial sector to the telecommunication sector immediately before the imposition of the ban, but there is no contagion for seven other non-financial sectors. There is no evidence of contagion while the ban was in force. In terms of preventing cross-sectoral contagion, the ban may be seen as a successful governance mechanism in the regulator?s toolbox.Peer reviewe