Publications by authors named "David Holloway"

Polar auxin transport (PAT) is a known component controlling leaf complexity and venation patterns in some model plant species. Evidence indicates that PAT generates auxin converge points (CPs) that in turn lead to local leaf formation and internally into major vein formation. However, the role of PAT in more diverse leaf arrangements and vein patterns is largely unknown.

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Recent computational modeling of early fruit fly () development has characterized the degree to which gene regulation networks can be robust to natural variability. In the first few hours of development, broad spatial gradients of maternally derived transcription factors activate embryonic gap genes. These gap patterns determine the subsequent segmented insect body plan through pair-rule gene expression.

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The inclusion of nurse practitioners (NPs) in critical care transport teams has the potential to enhance patient care and improve team operations. NPs can manage complex clinical situations during transport and excel in various roles such as leadership, education, mentoring, research, quality improvement, and clinical expertise. As we navigate the evolving landscape of critical care transport, it is crucial to explore the potential benefits offered by NPs.

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Introduction Patients with chronic pain (CP) are frequent users of general practitioners (GPs). Aim This study aimed to assess factors associated with the rate of GP visits related to pain in patients with CP. Methods This study used data collected by adult specialist pain management services (SPMS) that participated in the electronic Persistent Pain Outcomes Collaboration (ePPOC) in Australia.

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Introduction: Unlike monocots and dicots, many conifers, particularly , form three or more cotyledons. These are arranged in a whorl, or ring, at a particular distance from the embryo tip, with cotyledons evenly spaced within the ring. The number of cotyledons, , varies substantially within species, both in clonal cultures and in seed embryos.

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Since the establishment of the electronic Persistent Pain Outcomes Collaboration (ePPOC) in 2013, ongoing improvements in benchmarking and quality improvement activities have provided the opportunity for ePPOC to grow to support more than one hundred adult and pediatric services delivering care to Individuals living with persistent pain throughout Australia and New Zealand. These improvements straddle multiple domains, including benchmarking and indicators reports, internal and external research collaboration and the integration of quality improvement initiatives with pain services. This paper outlines improvements undertaken and lessons learned in relation to the growth and maintenance of a comprehensive outcomes registry and its articulation with pain services and the wider pain sector.

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The Bicoid (Bcd) protein is a primary determinant of early anterior-posterior (AP) axis specification in Drosophila embryogenesis. This morphogen is spatially distributed in an anterior-high gradient, and affects particular AP cell fates in a concentration-dependent manner. The early distribution and dynamics of the bicoid (bcd) mRNA, the source for the Bcd protein gradient, is not well understood, leaving a number of open questions for how Bcd positional information develops and is regulated.

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Spatial pattern formation of the primary anterior-posterior morphogenetic gradient of the transcription factor Bicoid (Bcd) has been studied experimentally and computationally for many years. Bcd specifies positional information for the downstream segmentation genes, affecting the fly body plan. More recently, a number of researchers have focused on the patterning dynamics of the underlying bcd messenger RNA (mRNA) gradient, which is translated into Bcd protein.

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Background And Aims: Conifer embryos, unlike those of monocots or dicots, have variable numbers of cotyledons, even within the same species. Cotyledons form in a single whorl on a dome-shaped embryo. The closely spaced cotyledons are not found outside this ring, indicating a radial control on where they can form.

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Anterior-posterior (AP) body segmentation of the fruit fly (Drosophila) is first seen in the 7-stripe spatial expression patterns of the pair-rule genes, which regulate downstream genes determining specific segment identities. Regulation of pair-rule expression has been extensively studied for the even-skipped (eve) gene. Recent live imaging, of a reporter for the 2nd eve stripe, has demonstrated the stochastic nature of this process, with 'bursts' in the number of RNA transcripts being made over time.

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Article Synopsis
  • Gene network simulations often focus on linear interactions between single genes, but real biological genes have more complex regulatory structures with multiple cis-regulatory modules (CRMs).
  • The hunchback (hb) gene in Drosophila development is a specific example that utilizes three CRMs to generate two different mRNA transcripts.
  • A modeling framework using differential equations is proposed to capture these regulatory dynamics, incorporating a genetic algorithms approach to screen potential interactions and validate them against biological expression data.
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Recent progress in microscopy technologies, biological markers, and automated processing methods is making possible the development of gene expression atlases at cellular-level resolution over whole embryos. Raw data on gene expression is usually very noisy. This noise comes from both experimental (technical/methodological) and true biological sources (from stochastic biochemical processes).

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Film possesses an extraordinary power and offers an unrivalled medium for entertainment and escapism. There are many films that revolve around a mental illness theme and the medical specialty that most commonly features in motion picture is psychiatry. Over the last few decades films have become increasingly used as an educational tool in the teaching of psychiatry topics such as mental state examination to undergraduate students.

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In recent years, with the development of automated microscopy technologies, the volume and complexity of image data on gene expression have increased tremendously. The only way to analyze quantitatively and comprehensively such biological data is by developing and applying new sophisticated mathematical approaches. Here, we present extensions of 2D singular spectrum analysis (2D-SSA) for application to 2D and 3D datasets of embryo images.

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In early development, genes are expressed in spatial patterns which later define cellular identities and tissue locations. The mechanisms of such pattern formation have been studied extensively in early Drosophila (fruit fly) embryos. The gap gene hunchback (hb) is one of the earliest genes to be expressed in anterior-posterior (AP) body segmentation.

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Modern evolutionary computation utilizes heuristic optimizations based upon concepts borrowed from the Darwinian theory of natural selection. Their demonstrated efficacy has reawakened an interest in other aspects of contemporary biology as an inspiration for new algorithms. However, amongst the many excellent candidates for study, contemporary models of biological macroevolution attract special attention.

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Biological development depends on the coordinated expression of genes in time and space. Developmental genes have extensive cis-regulatory regions which control their expression. These regions are organized in a modular manner, with different modules controlling expression at different times and locations.

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Study Objective: Acute aortic syndrome (AAS) is a medical emergency that requires prompt diagnosis and treatment at specialized centers. We sought to determine the frequency and etiology of false positive activation of a regional AAS network in a patient population emergently transferred for suspected AAS.

Methods: We evaluated 150 consecutive patients transferred from community emergency departments directly to our Cardiac Intensive Care Unit (CICU) with a diagnosis of suspected AAS between March, 2010 and August, 2011.

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Article Synopsis
  • A key focus in evolutionary biology is understanding how species transition from having a specific number of units (like limbs or body segments) to a different number.
  • Researchers explore the diversity of forms through evolutionary computations on a gene regulatory network model, examining how changes in embryonic development result in new forms.
  • Their findings show that these evolutionary changes are gradual and stable, aligning with observed patterns in species stability and adaptability.
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We study a chemical reaction-diffusion model (the Brusselator) for pattern formation on developing plant tips. A family of spherical cap domains is used to represent tip flattening during development. Applied to conifer embryos, we model the chemical prepatterning underlying cotyledon ("seed leaf") formation, and demonstrate the dependence of patterns on tip flatness, radius, and precursor concentrations.

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This paper surveys modeling approaches for studying the evolution of gene regulatory networks (GRNs). Modeling of the design or 'wiring' of GRNs has become increasingly common in developmental and medical biology, as a means of quantifying gene-gene interactions, the response to perturbations, and the overall dynamic motifs of networks. Drawing from developments in GRN 'design' modeling, a number of groups are now using simulations to study how GRNs evolve, both for comparative genomics and to uncover general principles of evolutionary processes.

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Patients with acute aortic syndrome (AAS) often require emergent transfer for definitive therapy. The aim of this study was to evaluate the safety of transfer and the ability to optimize hemodynamics in subjects with AAS transported by an aortic network. A total of 263 consecutive patients with suspected AAS transferred to a coronary care unit from March 2010 to June 2012 were included.

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Gene recruitment or cooption occurs when a gene, which may be part of an existing gene regulatory network (GRN), comes under the control of a new regulatory system. Such re-arrangement of pre-existing networks is likely more common for increasing genomic complexity than the creation of new genes. Using evolutionary computations (EC), we investigate how cooption affects the evolvability, outgrowth and robustness of GRNs.

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In the early 19th century, Lombroso introduced the concept of hereditary taint to describe the coexistence of 'madness' and creativity. In a recent investigation, Rust et al reported a study designed to test the traditionally assumed relationship between creativity and schizophrenia. They uncovered an association between creative originality and the positive cognitive aspects of schizotypal thinking.

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