Cold- and light-induced changes in the transcriptome of wheat leading to phase transition from vegetative to reproductive growth

Abstract. Background. For plants to flower at the appropriate time, they must be able to perceive and respond to various internal and external cues. Wheat is generally a long-day plant that will go through phase transition from vegetative to floral growth as days are lengthening in spring and early summer. In addition to this response to day-length, wheat cultivars may be classified as either winter or spring varieties depending on whether they require to be exposed to an extended period of cold in order to become competent to flower. Using a growth regime to mimic the conditions that occur during a typical winter in Britain, and a microarray approach to determine changes in gene expression over time, we have surveyed the genes of the major pathways involved in floral transition. We have paid particular attention to wheat orthologues and functional equivalents of genes involved in the phase transition in Arabidopsis. We also surveyed all the MADS-box genes that could be identified as such on the Affymetrix genechip wheat genome array. Results. We observed novel responses of several genes thought to be of major importance in vernalisation-induced phase transition, and identified several MADS-box genes that might play an important role in the onset of flowering. In addition, we saw responses in genes of the Gibberellin pathway that would indicate that this pathway also has some role to play in phase transition. Conclusion. Phase transition in wheat is more complex than previously reported, and there is evidence that day-length has an influence on genes that were once thought to respond exclusively to an extended period of cold

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p<0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p<0·001). Interpretation Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication. Funding DFID-MRC-Wellcome Trust Joint Global Health Trial Development Grant, National Institute of Health Research Global Health Research Unit Grant

Markedly different gene expression in wheat grown with organic or inorganic fertilizer

Nitrogen is the major determinant of crop yield and quality and the precise management of nitrogen fertilizer is an important issue for farmers and environmentalists. Despite this, little is known at the level of gene expression about the response of field crops to different amounts and forms of nitrogen fertilizer. Here we use expressed sequence tag (EST)-based wheat microarrays in combination with the oldest continuously running agricultural experiment in the world to show that gene expression is significantly influenced by the amount and form of nitrogenous fertilizer. In the Broadbalk winter wheat experiment at Rothamsted in the United Kingdom and at three other diverse test sites, we show that specific genes have surprisingly different expression levels in the grain endosperm when nitrogen is supplied either in an organic or an inorganic form. Many of the genes showing differential expression are known to participate in nitrogen metabolism and storage protein synthesis. However, others are of unknown function and therefore represent new leads for future investigation. Our observations show that specific gene expression is diagnostic for use of organic sources of nitrogen fertilizer and may therefore have useful applications in defining the differences between organically and conventionally grown wheat

Genome‐wide association studies of important agronomic traits in Brassica napus: what we have learned and where we are headed

Oilseed rape (Brassica napus L.; B. napus) is one of the main oil crops in China as well as in the world. Genome-wide association studies (GWAS) have revolutionised the field of complex agronomic traits. In B. napus, these include seed yield and yield-related traits, seed oil content, and abiotic and biotic stress-tolerance traits over the past decade in which hundreds of thousands to millions of genetic variants across the genomes of hundreds of individuals have been tested to identify genotype–phenotype associations. In this review, we assess the current status of GWAS in terms of genotypes, phenotypes, statistical models, and candidate genes for these agronomic traits in B. napus. Post-GWAS, the combination of QTL mapping, transcriptomics, and new statistical methods, has allowed us to identify candidate genes associated with specific agronomic traits. In addition, we can use diverse populations, increase the population size, or look for rare variants and structural variations of B. napus by whole-genome sequencing to minimise the ‘missing heritability’ effects. These approaches are essential for uncovering the genetic mechanisms defining or regulating complex agronomic traits and the delivery of molecular marker-assisted breeding in B. napus to breed new varieties that are higher yielding but resilient to our changing climate

A transcriptomics resource for wheat functional genomics

Grain development, germination and plant development under abiotic stresses are areas of biology that are of considerable interest to the cereal community. Within the Investigating Gene Function programme we have produced the resources required to investigate alterations in the transcriptome of hexaploid wheat during these developmental processes. We have single pass sequenced the cDNAs of between 700 and 1300 randomly picked clones from each of 35 cDNA libraries representing highly specific stages of grain and plant development. Annotated sequencing results have been stored in a publicly accessible, online database at http://www.cerealsdb.uk.net. Each of the tissue stages used has also been photographed in detail, resulting in a collection of high-quality micrograph images detailing wheat grain development. These images have been collated and annotated in order to produce a web site focused on wheat development (http://www.wheatbp.net/). We have also produced high-density microarrays of a publicly available wheat unigene set based on the 35 cDNA libraries and have completed a number of microarray experiments which validate their quality

Experimental investigation on the hysteresis behavior of the wire rope isolators

© 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg. Vibration isolation has been widely applied to filter the external excitation energy and impact forces in building structures and equipment. Wire rope isolator (WRI), a kind of isolator for vibration and shock isolation, shows a better performance in attenuating these forces. WRIs are able to deviate these external forces through their mechanical configuration and high-energy dissipative capabilities. The application of WRI demands knowledge of its behavior and the relation between various geometrical properties and input force. The present work investigates the influence of geometrical parameters, such as wire rope diameter, number of coils, and displacement amplitude on the hysteresis behavior of WRI under quasi-static loading in both vertical and horizontal directions. The hysteresis behavior of different WRIs was evaluated using the calculated parameters from hysteresis force-displacement curves: energy loss ratio (ELR), and effective stiffness. The study indicates that the geometric properties significantly influence the effective stiffness than the energy loss ratio. It is observed that, increased displacement amplitude results in decreased ELR and hence damping capabilities. The study also confirms that the wire rope isolator possesses a good ability in damping through its stiffness and high-energy dissipation capability