Magnetic field generation by pointwise zero-helicity three-dimensional steady flow of incompressible electrically conducting fluid

We introduce six families of three-dimensional space-periodic steady solenoidal flows, whose kinetic helicity density is zero at any point. Four families are analytically defined. Flows in four families have zero helicity spectrum. Sample flows from five families are used to demonstrate numerically that neither zero kinetic helicity density, nor zero helicity spectrum prohibit generation of large-scale magnetic field by the two most prominent dynamo mechanisms: the magnetic $\alpha$-effect and negative eddy diffusivity. Our computations also attest that such flows often generate small-scale field for sufficiently small magnetic molecular diffusivity. These findings indicate that kinetic helicity and helicity spectrum are not the quantities controlling the dynamo properties of a flow regardless of whether scale separation is present or not.Comment: 37 pages, 11 figures, 54 reference

Selective deactivation of gibberellins below the shoot apex is critical to flowering but not to stem elongation of Lolium

Gibberellins (GAs) cause dramatic increases in plant height and a genetic block in the synthesis of GA1 explains the dwarfing of Mendel's pea. For flowering, it is GA5 which is important in the long-day (LD) responsive grass, Lolium. As we show here, GA

Development of a brief measure of intimate partner violence experiences: The Composite Abuse Scale (Revised)-Short Form (CAS\u3csub\u3eR\u3c/sub\u3e-SF)

Objectives: Approaches to measuring intimate partner violence (IPV) in populations often privilege physical violence, with poor assessment of other experiences. This has led to underestimating the scope and impact of IPV. The aim of this study was to develop a brief, reliable and valid self-report measure of IPV that adequately captures its complexity. Design: Mixed-methods instrument development and psychometric testing to evolve a brief version of the Composite Abuse Scale (CAS) using secondary data analysis and expert feedback. Setting: Data from 5 Canadian IPV studies; feedback from international IPV experts. Participants: 31 international IPV experts including academic researchers, service providers and policy actors rated CAS items via an online survey. Pooled data from 6278 adult Canadian women were used for scale development. Primary/secondary outcome measures: Scale reliability and validity; robustness of subscales assessing different IPV experiences. Results: A 15-item version of the CAS has been developed (Composite Abuse Scale (Revised)-Short Form, CASR-SF), including 12 items developed from the original CAS and 3 items suggested through expert consultation and the evolving literature. Items cover 3 abuse domains: physical, sexual and psychological, with questions asked to assess lifetime, recent and current exposure, and abuse frequency. Factor loadings for the final 3-factor solution ranged from 0.81 to 0.91 for the 6 psychological abuse items, 0.63 to 0.92 for the 4 physical abuse items, and 0.85 and 0.93 for the 2 sexual abuse items. Moderate correlations were observed between the CASR-SF and measures of depression, post-traumatic stress disorder and coercive control. Internal consistency of the CASR-SF was 0.942. These reliability and validity estimates were comparable to those obtained for the original 30-item CAS. Conclusions: The CASR-SF is brief self-report measure of IPV experiences among women that has demonstrated initial reliability and validity and is suitable for use in population studies or other studies. Additional validation of the 15-item scale with diverse samples is required

Seeing and Overcoming the Complexities of Intersectionality

Background: Intersectionality contests that individuals have multiple characteristics in their identity that cannot be siloed or deemed exclusive to each other. Understanding and utilising an intersectional lens in organisations can increase inclusion of individuals and organisational performance. An educational package known as the IntersectionalityWalk (IW) was developed by the authors, piloted, and evaluated in order to break down the commonly held descriptors of diversity silos that fragments inclusion, and to understand how various identity characteristics compound disadvantage. The paper outlines the need to transition from siloed views of diversity to a more intrinsic view of identity to achieve inclusivity. Methods: The IW was developed and trialled with a series of work-based scenarios and realistic multifaceted personas. Data collection occurred preand post-IW utilising a mixed methods approach. Responses to Likert scale surveys and open-ended questions were captured and analysed via inductive and grounded theory perspectives. Results: An improved awareness and understanding of individual knowledge, reflectivity and positionality relating to intersectionality and intersectional approaches was reported on completion of the IW. Furthermore, responses reported how and why organisations can approach and improve inclusivity via using intersectional approaches. Conclusions: The IW as an educational package has a positive impact and is a key linkage for all employers to build an inclusive culture and to harness the talent of all employees. Further research will occur to measure the implemented change in organisations following the IW

Rht18 semidwarfism in wheat is due to increased GA 2-oxidaseA9 expression and reduced GA content

Semidwarfing genes have improved crop yield by reducing height, improving lodging resistance, and allowing plants to allocate more assimilates to grain growth. In wheat (Triticum aestivum), the Rht18 semidwarfing gene was identified and deployed in durum wheat before it was transferred into bread wheat, where it was shown to have agronomic potential. Rht18, a dominant and gibberellin (GA) responsive mutant, is genetically and functionally distinct from the widely used GA-insensitive semidwarfing genes Rht-B1b and Rht-D1b. In this study, the Rht18 gene was identified by mutagenizing the semidwarf durum cultivar Icaro (Rht18) and generating mutants with a range of tall phenotypes. Isolating and sequencing chromosome 6A of these "overgrowth"mutants showed that they contained independent mutations in the coding region of GA2oxA9. GA2oxA9 is predicted to encode a GA 2-oxidase that metabolizes GA biosynthetic intermediates into inactive products, effectively reducing the amount of bioactive GA (GA1). Functional analysis of the GA2oxA9 protein demonstrated that GA2oxA9 converts the intermediate GA12 to the inactive metabolite GA110. Furthermore, Rht18 showed higher expression of GA2oxA9 and lower GA content compared with its tall parent. These data indicate that the increased expression of GA2oxA9 in Rht18 results in a reduction of both bioactive GA content and plant height. This study describes a height-reducing mechanism that can generate new genetic diversity for semidwarfism in wheat by combining increased expression with mutations of specific amino acid residues in GA2oxA9

Tissue and cell-specific transcriptomes in cotton reveal the subtleties of gene regulation underlying the diversity of plant secondary cell walls

Background Knowledge of plant secondary cell wall (SCW) regulation and deposition is mainly based on the Arabidopsis model of a ‘typical’ lignocellulosic SCW. However, SCWs in other plants can vary from this. The SCW of mature cotton seed fibres is highly cellulosic and lacks lignification whereas xylem SCWs are lignocellulosic. We used cotton as a model to study different SCWs and the expression of the genes involved in their formation via RNA deep sequencing and chemical analysis of stem and seed fibre. Results Transcriptome comparisons from cotton xylem and pith as well as from a developmental series of seed fibres revealed tissue-specific and developmentally regulated expression of several NAC transcription factors some of which are likely to be important as top tier regulators of SCW formation in xylem and/or seed fibre. A so far undescribed hierarchy was identified between the top tier NAC transcription factors SND1-like and NST1/2 in cotton. Key SCW MYB transcription factors, homologs of Arabidopsis MYB46/83, were practically absent in cotton stem xylem. Lack of expression of other lignin-specific MYBs in seed fibre relative to xylem could account for the lack of lignin deposition in seed fibre. Expression of a MYB103 homolog correlated with temporal expression of SCW CesAs and cellulose synthesis in seed fibres. FLAs were highly expressed and may be important structural components of seed fibre SCWs. Finally, we made the unexpected observation that cell walls in the pith of cotton stems contained lignin and had a higher S:G ratio than in xylem, despite that tissue’s lacking many of the gene transcripts normally associated with lignin biosynthesis. Conclusions Our study in cotton confirmed some features of the currently accepted gene regulatory cascade for ‘typical’ plant SCWs, but also revealed substantial differences, especially with key downstream NACs and MYBs. The lignocellulosic SCW of cotton xylem appears to be achieved differently from that in Arabidopsis. Pith cell walls in cotton stems are compositionally very different from that reported for other plant species, including Arabidopsis. The current definition of a ‘typical’ primary or secondary cell wall might not be applicable to all cell types in all plant species.CPM was funded by Cotton Breeding Australia, a joint venture between Cotton Seed Distributors and CSIRO (Project No. CBA19). HB was funded by the CSIRO’s Office of the Chief Executive (OCE) Postdoctoral Fellowship program. YT and JR were funded in part by Stanford University’s Global Climate and Energy Program, and in part by the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science, DE-FC02–07ER6449

Cotton breeding in Australia : meeting the challenges of the 21st century

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) cotton breeding program is the sole breeding effort for cotton in Australia, developing high performing cultivars for the local industry which is worth∼AU$3 billion per annum. The program is supported by Cotton Breeding Australia, a Joint Venture between CSIRO and the program’s commercial partner, Cotton Seed Distributors Ltd. (CSD). While the Australian industry is the focus, CSIRO cultivars have global impact in North America, South America, and Europe. The program is unique compared with many other public and commercial breeding programs because it focuses on diverse and integrated research with commercial outcomes. It represents the full research pipeline, supporting extensive long-term fundamental molecular research; native and genetically modified (GM) trait development; germplasm enhancement focused on yield and fiber quality improvements; integration of third-party GM traits; all culminating in the release of new commercial cultivars. This review presents evidence of past breeding successes and outlines current breeding efforts, in the areas of yield and fiber quality improvement, as well as the development of germplasm that is resistant to pests, diseases and abiotic stressors. The success of the program is based on the development of superior germplasm largely through field phenotyping, together with strong commercial partnerships with CSD and Bayer CropScience. These relationships assist in having a shared focus and ensuring commercial impact is maintained, while also providing access to markets, traits, and technology. The historical successes, current foci and future requirements of the CSIRO cotton breeding program have been used to develop a framework designed to augment our breeding system for the future. This will focus on utilizing emerging technologies from the genome to phenome, as well as a panomics approach with data management and integration to develop, test and incorporate new technologies into a breeding program. In addition to streamlining the breeding pipeline for increased genetic gain, this technology will increase the speed of trait and marker identification for use in genome editing, genomic selection and molecular assisted breeding, ultimately producing novel germplasm that will meet the coming challenges of the 21st Century

Genomewide analysis of the lateral organ boundaries domain gene family in Eucalyptus grandis reveals members that differentially impact secondary growth

Lateral Organ Boundaries Domain (LBD) proteins are plant-specific transcription factors playing crucial roles in growth and development. However, the function of LBD proteins in Eucalyptus grandis remains largely unexplored. In this study, LBD genes in E. grandis were identified and characterized using bioinformatics approaches. Gene expression patterns in various tissues and the transcriptional responses of EgLBDs to exogenous hormones were determined by qRT-PCR. Functions of the selected EgLBDs were studied by ectopically overexpressing in a hybrid poplar (Populus alba 9 Populus glandulosa). Expression levels of genes in the transgenic plants were investigated by RNA-seq. Our results showed that there were forty-six EgLBD members in the E. grandis genome and three EgLBDs displayed xylem- (EgLBD29) or phloem-preferential expression (EgLBD22 and EgLBD37). Confocal microscopy indicated that EgLBD22, EgLBD29 and EgLBD37 were localized to the nucleus. Furthermore, we found that EgLBD22, EgLBD29 and EgLBD37 were responsive to the treatments of indol- 3-acetic acid and gibberellic acid. More importantly, we demonstrated EgLBDs exerted different influences on secondary growth. Namely, 35S::EgLBD37 led to significantly increased secondary xylem, 35S::EgLBD29 led to greatly increased phloem fibre production, and 35S:: EgLBD22 showed no obvious effects. We revealed that key genes related to gibberellin, ethylene and auxin signalling pathway as well as cell expansion were significantly up- or down-regulated in transgenic plants. Our new findings suggest that LBD genes in E. grandis play important roles in secondary growth. This provides new mechanisms to increase wood or fibre production.Figure S1 Conserved domains of EgLBD protein family.Figure S2 The chromosomal localization of the LBD gene family in Eucalyptus grandis.Figure S3 Subcellular localization of EgLBD22, EgLBD29 and EgLBD37 proteins.Figure S4 Gel electrophoresis analysis for the presence of the transgene in EgLBD22-oe, EgLBD29-oe and EgLBD37-oe plants.Figure S5 Validation for the expression of the transgene in EgLBD22-oe, EgLBD29-oe and EgLBD37-oe plants by qRT-PCR.Table S1 All the primers used in this study.Table S2 The coding sequences of LBD genes in Eucalyptus grandis.Table S3 The information of LBD gene family in Eucalyptus grandis.Table S4 Conserved motifs predicted by MEME program in EgLBD proteins.Table S5 Protein-protein interaction prediction for possible functional protein association networks of EgLBD22.Table S6 Protein-protein interaction prediction for possible functional protein association networks of EgLBD29.Table S7 Protein-protein interaction prediction for possible functional protein association networks of EgLBD37.Table S8 The differentially expressed genes between EgLBD22-oe and WT-84k plants.Table S9 The differentially expressed genes between EgLBD29-oe and WT-84k plants.Table S10 The differentially expressed genes between EgLBD37-oe and WT-84k plants.Table S11 The information of eight key differentially expressed genes in EgLBD22-oe, EgLBD29-oe and EgLBD37-oe plants.Basic Research Fund of RIF [RIF2014-01]; Natural Science Foundation of China [31670676]; Mondi and Sappi through the Forest Molecular Genetics Programme; Technology and Human Resources for Industry Programme [UID 80118]; National Research Foundation of South Africa [UID 18312, 71255, 86936]http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1467-7652am2018Forestry and Agricultural Biotechnology Institute (FABI)Genetic

An autoactive NB-LRR gene causes Rht13 dwarfism in wheat

Semidwarfing genes have greatly increased wheat yields globally, yet the widely used gibberellin (GA)-insensitive genes Rht-B1b and Rht-D1b have disadvantages for seedling emergence. Use of the GA-sensitive semidwarfing gene Rht13 avoids this pleiotropic effect. Here, we show that Rht13 encodes a nucleotide-binding site/leucine-rich repeat (NB-LRR) gene. A point mutation in the semidwarf Rht-B13b allele autoactivates the NB-LRR gene and causes a height reduction comparable with Rht-B1b and Rht-D1b in diverse genetic backgrounds. The autoactive Rht-B13b allele leads to transcriptional up-regulation of pathogenesis-related genes including class III peroxidases associated with cell wall remodeling. Rht13 represents a new class of reduced height (Rht) gene, unlike other Rht genes, which encode components of the GA signaling or metabolic pathways. This discovery opens avenues to use autoactive NB-LRR genes as semidwarfing genes in a range of crop species, and to apply Rht13 in wheat breeding programs using a perfect genetic marker