Quantitative imaging of the collective cell movements shaping an embryo

The recent development of imaging and image processing techniques, such as 4D microscopy and 3D cell tracking, enables analysis through quantification of the movement of large cell populations in vivo. These imaging approaches provide an opportunity to study embryonic morphogenesis during development from the level of cellular processes to the scale of entire organism. Image analysis reveals cell collective behaviors that shape an embryo and offers some surprising insights into the cell-cell interactions involved in concerted movements. We illustrate the power of this approach by studying the early development of Drosophila embryos

Understanding Behavioral Responses of Wildlife to Traffic to Improve Mitigation Planning

Creating and maintaining sustainable transportation systems depends in part on understanding and mitigating ecological impacts. Wildlife crossing structures (WCS) are often used to mitigate impacts on wildlife populations. WCS and existing structures may provide passage for multiple species, depending on their sensitivity to traffic disturbance and perception of the roadway. In a previous project, the research team found that traffic conditions and traffic noise could reduce WCS effectiveness in facilitating passage of diverse and sensitive species. In the current project, they expanded the geographic scope to 26 sites throughout California, including detailed measurements of vehicle noise and lighting impacts on wildlife use of structures. They investigated individual animal behavior as the animals approached structures as a possible mechanism for reducing species diversity due to traffic disturbance. In order to inform future WCS planning, placement and construction, the team studied traffic noise and light impacts on wildlife in the vicinity of the proposed Liberty Canyon wildlife over-crossing (over US 101), the first and largest of its kind in California. They improved a preliminary statistical model of the effects of traffic on WCS use of existing structures. The authors recommend strategies for transportation agencies to use in developing and modifying WCS to improve wildlife passage.View the NCST Project Webpag

History in the hands of the Contemporary Playwright 2000-2015: a feminist critique of normative historiography in British theatre.

Between 2000 and 2015 twelve of the UK’s leading producing theatres premiered twenty three plays by British playwrights where the action was set between 1882-1928. This historical period is significant; in 1882 the Married Women’s Property Act was passed and in 1928 equal enfranchisement for men and women was granted in the United Kingdom, hence, the historical period traces a shift in women’s rights from property ownership to the vote. This thesis investigates narratives within these plays and explores the development of a normative historiography that is drawn on, but predominantly left unquestioned, by playwrights as Britain’s past is reimagined. It is this normative historiography, operating in a theatrical context, which the thesis problematises and interrogates through the lens of contemporary British playwriting. This lens facilitates an exploration of the manner in which the representation of the past mirrors and/or challenges current feminist discourse and considers the cultural implications of the structures and techniques employed to retell women their history through this medium. Scholarship from the fields of academic and popular feminism, theatre studies, history and historiography shape the analytical framework of the thesis. Drawing on literature from these fields, this study conducts historically informed performance analysis that seeks to discover the sociocultural work done by contemporary plays that engage with the past. Archives of thirty British theatres have been surveyed to produce a database of plays that fall within the project boundaries; working with this data, trends and recurring themes have been identified, and subsequently chapters have been shaped to investigate dramaturgical questions in response to the field research. The dramaturgical questions explore: recurring modes of representation in plays that reimagine World War One; the representation of opposition in depictions of historical conflict; the retelling of specific historical narratives in relation to the challenge of staging ideas; and the recurrence of the heteronormative romantic plot. This thesis argues that when the playwright interrogates the normative dramaturgies and tropes they have inherited for historical representation, they assumes the role of historiographer and from this self-reflexive position recurring theatrical conventions for retelling the past are challenged. This perspective shifts attention beyond central patriarchal narratives of the past and facilitates engagement with the multiple avenues of enquiry regarding a historical moment. Engagement with the work of playwrights who foreground a historiographic awareness in their process, further illuminates the dialogue between representations of women in a historical context and contemporary feminist debate.Arts and Humanities Research Counci

Cereal grain, rachis and pulse seed amino acid δ15N values as indicators of plant nitrogen metabolism

AbstractNatural abundance δ15N values of plant tissue amino acids (AAs) reflect the cycling of N into and within plants, providing an opportunity to better understand environmental and anthropogenic effects on plant metabolism. In this study, the AA δ15N values of barley (Hordeum vulgare) and bread wheat (Triticum aestivum) grains and rachis and broad bean (Vicia faba) and pea (Pisum sativum) seeds, grown at the experimental farm stations of Rothamsted, UK and Bad Lauchstädt, Germany, were determined by GC–C–IRMS. It was found that the δ15N values of cereal grain and rachis AAs could be largely attributed to metabolic pathways involved in their biosynthesis and catabolism. The relative 15N-enrichment of phenylalanine can be attributed to its involvement in the phenylpropanoid pathway and glutamate has a δ15N value which is an average of the other AAs due to its central role in AA–N cycling. The relative AA δ15N values of broad bean and pea seeds were very different from one another, providing evidence for differences in the metabolic routing of AAs to the developing seeds in these leguminous plants. This study has shown that AA δ15N values relate to known AA biosynthetic pathways in plants and thus have the potential to aid understanding of how various external factors, such as source of assimilated N, influence metabolic cycling of N within plants

What minimum wage? Why enforcement of EU migrants’ employment rights matters

EU migrants nominally enjoy the same employment rights as Britons. Yet (left to right) Catherine Barnard, Amy Ludlow and Sarah Fraser Butlin of the EU Migrant Worker Project found that they are often ignorant of the minimum wage and the Working Time Directive and do not pursue claims in Employment Tribunals. In this they are sometimes aided and abetted by exploitative employers who are willing to use them to undercut the wages of UK staff. They also found that enforcement of employment rights in the UK is, at best, patchy

Chytrid fungus infection in alpine tree frogs is associated with individual heterozygosity and population isolation but not population-genetic diversity

Chytridiomycosis, a disease caused by the emerging fungus Batrachochytrium dendrobatidis (Bd), has been implicated in the decline of over 500 amphibian species. Population declines could have important genetic consequences, including reduced genetic diversity. We contrasted genetic diversity among both long-Bd-exposed and unexposed populations of the south-east Australian alpine tree frog (Litoria verreauxii alpina) across its range. At the population level, we found no significant differences in genetic diversity between Bd-exposed and unexposed populations. Encouragingly, even Bd-infected remnant populations that are now highly isolated maintain genetic diversity comparable to populations in which Bd is absent. Spatial genetic structure among populations followed an isolation-by-distance pattern, suggesting restricted movement among remnant populations. At the individual level, greater heterozygosity was associated with reduced probability of infection. Loss of genetic diversity in remnant populations that survived chytridiomycosis epidemics does not appear to be a threat to L. v. alpina. We suggest several factors underpinning maintenance of genetic diversity: (1) remnant populations have remained large enough to avoid losses of genetic diversity; (2) many individuals in the population are able to breed once before succumbing to disease; and (3) juveniles in the terrestrial environment have low exposure to Bd, providing an annual ‘reservoir’ of genetic diversity. The association between individual heterozygosity and infection status suggests that, while other work has shown all breeding adults are typically killed by Bd, males with greater heterozygosity may survive longer and obtain fitness benefits through extended breeding opportunities. Our results highlight the critical role of life history in mitigating the impacts of Bd infection for some amphibian species, but we infer that increased isolation as a result of disease-induced population extirpations will enhance population differentiation and thus biogeographic structure

Roundtable Discussion – The Great War and Education

The panelists will discus their experiences in teaching the First World War to students at the secondary and post-sencondary level

Quantitative imaging of collective cell migration during Drosophila gastrulation: multiphoton microscopy and computational analysis

This protocol describes imaging and computational tools to collect and analyze live imaging data of embryonic cell migration. Our five-step protocol requires a few weeks to move through embryo preparation and four-dimensional (4D) live imaging using multiphoton microscopy, to 3D cell tracking using image processing, registration of tracking data and their quantitative analysis using computational tools. It uses commercially available equipment and requires expertise in microscopy and programming that is appropriate for a biology laboratory. Custom-made scripts are provided, as well as sample datasets to permit readers without experimental data to carry out the analysis. The protocol has offered new insights into the genetic control of cell migration during Drosophila gastrulation. With simple modifications, this systematic analysis could be applied to any developing system to define cell positions in accordance with the body plan, to decompose complex 3D movements and to quantify the collective nature of cell migration

Dynamic Analyses of Drosophila Gastrulation Provide Insights into Collective Cell Migration

The concerted movement of cells from different germ layers contributes to morphogenesis during early embryonic development. Using an optimized imaging approach and quantitative methods, we analyzed the trajectories of hundreds of ectodermal cells and internalized mesodermal cells within Drosophila embryos over 2 hours during gastrulation. We found a high level of cellular organization, with mesoderm cell movements correlating with some but not all ectoderm movements. During migration, the mesoderm population underwent two ordered waves of cell division and synchronous cell intercalation, and cells at the leading edge stably maintained position. Fibroblast growth factor (FGF) signaling guides mesodermal cell migration; however, we found some directed dorsal migration in an FGF receptor mutant, which suggests that additional signals are involved. Thus, decomposing complex cellular movements can provide detailed insights into collective cell migration