323 research outputs found
Light and circadian regulation of clock components aids flexible responses to environmental signals
The circadian clock measures time across a 24h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O.tauri primarily tracked dawn or dusk, whereas in A.thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O.tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O.tauri has adopted the latter strategy, possibly as a consequence of genomic reduction
Conducting Virtual Qualitative Interviews with International Key Informants: Insights from a Research Project
There is an increasing need for cross-cultural qualitative studies in an era of globalization. A focus group of five researchers, who were involved in a large international research project, identified effective strategies and challenges associated with five key domains of qualitative research with key informants: identification, recruitment, preparation, conducting the interview, and follow-up. Content analysis revealed nuanced tactics related to effective strategies and challenges associated with each domain. Examples of effective strategies include interview preparation to understand the specific expertise of the interviewee and allowing the informant to offer additional information beyond the questions asked. Challenges included technical difficulties with virtual platforms and scheduling interviews in multiple time zones. These findings provide practical guidelines for researchers conducting virtual interviews with international key informants
The Brahmaputra tale of tectonics and erosion:early Miocene river capture in the Eastern Himalaya
The Himalayan orogen provides a type example on which a number of models of the causes and consequences of crustal deformation are based and it has been suggested that it is the site of a variety of feedbacks between tectonics and erosion. Within the broader orogen, fluvial drainages partly reflect surface uplift, different climatic zones and a response to crustal deformation. In the eastern Himalaya, the unusual drainage configuration of the Yarlung TsangpoâBrahmaputra River has been interpreted either as antecedent drainage distorted by the IndiaâAsia collision (and as such applied as a passive strain marker of lateral extrusion), latest Neogene tectonically-induced river capture, or glacial damming-induced river diversion events. Here we apply a multi-technique approach to the Neogene paleo-Brahmaputra deposits of the Surma Basin (Bengal Basin, Bangladesh) to test the long-debated occurrence and timing of river capture of the Yarlung Tsangpo by the Brahmaputra River. We provide UâPb detrital zircon and rutile, isotopic (SrâNd and Hf) and petrographic evidence consistent with river capture of the Yarlung Tsangpo by the Brahmaputra River in the Early Miocene. We document influx of CretaceousâPaleogene zircons in Early Miocene sediments of the paleo-Brahmaputra River that we interpret as first influx of material from the Asian plate (Transhimalayan arc) indicative of Yarlung Tsangpo contribution. Prior to capture, the predominantly PrecambrianâPaleozoic zircons indicate that only the Indian plate was drained. Contemporaneous with Transhimalayan influx reflecting the river capture, we record arrival of detrital material affected by Cenozoic metamorphism, as indicated by rutiles and zircons with Cenozoic UâPb ages and an increase in metamorphic grade of detritus as recorded by petrography. We interpret this as due to a progressively increasing contribution from the erosion of the metamorphosed core of the orogen. Whole rock SrâNd isotopic data from the same samples provide further support to this interpretation. River capture may have been caused by a change in relative base level due to uplift of the Tibetan plateau. Assuming such river capture occurred via the Siang River in the Early Miocene, we refute the âtectonic aneurysmâ model of tectonicâerosion coupling between river capture and rapid exhumation of the eastern syntaxis, since a time interval of at least 10 Ma between these two events is now demonstrated. This work is also the first to highlight UâPb dating on detrital rutile as a powerful approach in provenance studies in the Himalaya in combination with zircon UâPb chronology
Studentsâ perspectives of using the hub and spoke model to support and develop learning in practice
The acquisition of competence in learning is dependent on a number of variables. Students need to feel a sense of security in the practice learning area to be able to fully develop the skills required. Hub and Spoke is one model for practice learning that has been integrated in Edinburgh Napier University undergraduate nursing programme since 2011. It relates to enhancing the quality of practice learning by improving the student experience of security and belongingness in the practice environment. Rather than focusing on the benefits of the model, this study explores the characteristics of the Hub and Spoke model that supports students learning, to develop a deep understanding of a person centred approach to care. The study involved nursing students from two different fields of practice and employed a mixed methods approach, using a combination of focus group activity and an adapted questionnaire based upon the principles of Belongingness and the SENSES Framework. These principles were selected to capture the lived experience of the student undertaking these Spoke experiences. Focus group themes emerged as 'Learning for student value', 'Connections' and 'Organisation'
ISBS 2018 AUCKLAND CONFERENCE AUT MILLENNIUM TEACHERS DAY
Dr Sarah Kate Millar is coordinating the New Zealand Biomechanics Teachers Day. Teachers will have the opportunity to work side-by-side with leading biomechanics instructors/researcher from across the world. There will be a focus on creating hands-on experiential learning opportunities to achieve science and physical education outcomes.
Sarah-Kate Millar is a senior lecturer at AUT (AUT) in the area of sports coaching and in particular skill acquisition. Dr. Kim HĂ©bert-Losier is a Senior Lecturer in Applied Biomechanics and Injury Prevention at the University of Waikato. Dr Laura-Anne M Furlong is a Lecturer in Biomechanics, currently based in the School of Sport, Exercise and Health Sciences at Loughborough University, and the National Centre for Sports and Exercise Medicine. Dr Philip Fink is Senior Lecturer in motor control and biomechanics at the School of Sport, Exercise and Nutrition at Massey University. Dr Duane Knudson is a Professor in the Department of Health & Human Performance at Texas State University. Suzie Belcher is currently working with Netball New Zealand as part of their national Injury prevention team, NetballSmart
Light and circadian regulation of clock components aids flexible responses to environmental signals
PublishedJournal ArticleResearch Support, Non-U.S. Gov'tThe circadian clock measures time across a 24 h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O. tauri primarily tracked dawn or dusk, whereas in A. thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O. tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O. tauri has adopted the latter strategy, possibly as a consequence of genomic reduction.This research was supported by EU FP7 collaborative project TiMet (award 245143), BBSRC and EPSRC awards BB/F005237/1, BB/D019621/1 and BB/J009423 (to A.J.M. and others) and EPSRC award EP/I017445/1 (to O.E.A. and others). C.T.'s work was supported by the Human Frontiers Science Program and the Swedish Research Council (award 2010-5219)
A switchable light-input, light-output system modelled and constructed in yeast
<p>Abstract</p> <p>Background</p> <p>Advances in synthetic biology will require spatio-temporal regulation of biological processes in heterologous host cells. We develop a light-switchable, two-hybrid interaction in yeast, based upon the Arabidopsis proteins PHYTOCHROME A and FAR-RED ELONGATED HYPOCOTYL 1-LIKE. Light input to this regulatory module allows dynamic control of a light-emitting LUCIFERASE reporter gene, which we detect by real-time imaging of yeast colonies on solid media.</p> <p>Results</p> <p>The reversible activation of the phytochrome by red light, and its inactivation by far-red light, is retained. We use this quantitative readout to construct a mathematical model that matches the system's behaviour and predicts the molecular targets for future manipulation.</p> <p>Conclusion</p> <p>Our model, methods and materials together constitute a novel system for a eukaryotic host with the potential to convert a dynamic pattern of light input into a predictable gene expression response. This system could be applied for the regulation of genetic networks - both known and synthetic.</p
The initiation and evolution of the River Nile
This work was funded by a NERC Open CASE PhD studentship award NE/I018433/1, the NERC Isotope Geoscience Facilities Steering Committee (IP-1248-0511, IP-1299-0512), and BP Egypt who we also thank for provision of samples and assistance in Egypt. We thank C. Stewart, V. Pashley and N. Roberts at NIGL for valuable laboratory assistance. This paper benefited from careful reviews by D. Chew and an anonymous reviewer.Peer reviewedPublisher PD
The circadian clock gene circuit controls protein and phosphoprotein rhythms in Arabidopsis thaliana
Twenty-four-hour, circadian rhythms control many eukaryotic mRNA levels, whereas the levels of their more stable proteins are not expected to reflect the RNA rhythms, emphasizing the need to test the circadian regulation of protein abundance and modification. Here we present circadian proteomic and phosphoproteomic time series from Arabidopsis thaliana plants under constant light conditions, estimating that just 0.4% of quantified proteins but a much larger proportion of quantified phospho-sites were rhythmic. Approximately half of the rhythmic phospho-sites were most phosphorylated at subjective dawn, a pattern we term the âphospho-dawn.â Members of the SnRK/CDPK family of protein kinases are candidate regulators. A CCA1-overexpressing line that disables the clock gene circuit lacked most circadian protein phosphorylation. However, the few phospho-sites that fluctuated despite CCA1-overexpression still tended to peak in abundance close to subjective dawn, suggesting that the canonical clock mechanism is necessary for most but perhaps not all protein phosphorylation rhythms. To test the potential functional relevance of our datasets, we conducted phosphomimetic experiments using the bifunctional enzyme fructose-6-phosphate-2-kinase/phosphatase (F2KP), as an example. The rhythmic phosphorylation of diverse protein targets is controlled by the clock gene circuit, implicating posttranslational mechanisms in the transmission of circadian timing information in plants
Multiomic Mass Spectrometry Imaging to Advance Future Pathological Understanding of Ocular Disease.
Determining the locations of proteins within the eye thought to be involved in ocular pathogenesis is important to determine how best to target them for therapeutic benefits. However, immunohistochemistry is limited by the availability and specificity of antibodies. Additionally, the perceived role of both essential and non-essential metals within ocular tissue has been at the forefront of age-related macular degeneration (AMD) pathology for decades, yet even key metals such as copper and zinc have yet to have their roles deconvoluted. Here, mass spectrometry imaging (MSI) is employed to identify and spatially characterize both proteomic and metallomic species within ocular tissue to advance the application of a multiomic imaging methodology for the investigation of ocular diseases
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