Tridimensional model structure and patterns of molecular evolution of Pepino mosaic virus TGBp3 protein

<p>Abstract</p> <p>Background</p> <p><it>Pepino mosaic virus </it>(PepMV) is considered one of the most dangerous pathogens infecting tomatoes worldwide. The virus is highly diverse and four distinct genotypes, as well as inter-strain recombinants, have already been described. The isolates display a wide range on symptoms on infected plant species, ranging from mild mosaic to severe necrosis. However, little is known about the mechanisms and pattern of PepMV molecular evolution and about the role of individual proteins in host-pathogen interactions.</p> <p>Methods</p> <p>The nucleotide sequences of the triple gene block 3 (TGB3) from PepMV isolates varying in symptomatology and geographic origin have been analyzed. The modes and patterns of molecular evolution of the TGBp3 protein were investigated by evaluating the selective constraints to which particular amino acid residues have been subjected during the course of diversification. The tridimensional structure of TGBp3 protein has been modeled <it>de novo </it>using the Rosetta algorithm. The correlation between symptoms development and location of specific amino acids residues was analyzed.</p> <p>Results</p> <p>The results have shown that TGBp3 has been evolving mainly under the action of purifying selection operating on several amino acid sites, thus highlighting its functional role during PepMV infection. Interestingly, amino acid 67, which has been previously shown to be a necrosis determinant, was found to be under positive selection.</p> <p>Conclusions</p> <p>Identification of diverse selection events in TGB3p3 will help unraveling its biological functions and is essential to an understanding of the evolutionary constraints exerted on the <it>Potexvirus </it>genome. The estimated tridimensional structure of TGBp3 will serve as a platform for further sequence, structural and function analysis and will stimulate new experimental advances.</p

Physicochemical, textural and viscoelastic properties of palm diacylglycerol bakery shortening during storage

BACKGROUND: Diacylglycerol (DAG), which has health-enhancing properties, is sometimes added to bakery shortening to produce baked products with enhanced physical functionality. Nevertheless, the quantity present is often too little to exert any positive healthful effects. This research aimed to produce bakery shortenings containing significant amounts of palm diacyglycerol (PDG). Physicochemical, textural and viscoelastic properties of the PDG bakery shortenings during 3 months storage were evaluated and compared with those of commercial bakery shortening (CS). RESULTS: PDG bakery shortenings (DS55, DS64 and DS73) had less significant increments in slip melting point (SMP), solid fat content (SFC) and hardness during storage as compared to CS. Unlike CS, melting behaviour and viscoelastic properties of PDG bakery shortenings remained unchanged during storage. As for polymorphic transformation, CS contained only β crystals after 8 weeks of storage. PDG bakery shortenings managed to retard polymorphic transformation for up to 10 weeks of storage in DS55 and 12 weeks of storage in DS64 and DS73. CONCLUSION: PDG bakery shortenings had similar if not better storage stability as compared to CS. This is mainly due to the ability of DAG to retard polymorphic transformation from β′ to β crystals. Thus, incorporation of DAG improved physical functionality of bakery shortening

Why are physical assessment skills not practiced? A systematic review with implications for nursing education.

Background Physical assessment skills are taught in pre-registration nursing programs to equip nurses with the competencies to provide holistic nursing care. However, only a fraction of the skills they acquired during training are routinely performed in clinical practice thus highlighting a disconnect between learning and practicing. Objective To better understand the issues surrounding the teaching and practice of physical assessment skills among nurses as described in the literature. Design A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was used. Review method A search of databases including PubMed, EMBASE, CINAHL and Scopus was conducted from January 1970 to December 2019. Two independent researchers performed the methodological quality assessment using the Joanna Briggs Institute's Critical Appraisal Checklists. Twenty-one papers, including two qualitative studies, 17 quantitative studies and two mixed methods study, were selected in this review. Data were synthesised narratively. Results The review identified six overarching themes: (1) role ambiguity, (2) reliance on technology, (3) collegial support and culture, (4) practice variations across specialties, (5) a lack of confidence and knowledge, and (6) over-teaching using biomedical model. Conclusion This review identified the need to improve the teaching of the physical assessment skills. There is also a need to evaluate the physical assessment content taught within nursing curricula, with emphasis on depth rather than breadth of skills. The ability to interpret physical assessment observations and develop clinical judgement need to be incorporated into the curriculum. To aid in the development of an effective care plan, the physical assessment framework should move away from a biomedical framework to include nursing models such as nursing process and clinical reasoning model. This revised framework can be used in future studies in the development and testing of teaching and evaluation tools for physical assessment skills