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1.
Air Med J ; 43(2): 163-167, 2024.
Article in English | MEDLINE | ID: mdl-38490781

ABSTRACT

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. Their distinct skills and experiences effectively position them to improve patient outcomes, enhance team performance, and contribute to health care's financial sustainability. This article discusses the role of NPs in critical care transport, providing insight into their current uses, and recommendations for optimal use.


Subject(s)
Nurse Practitioners , Humans , Critical Care , Leadership , Clinical Competence
2.
J Prim Health Care ; 15(3): 199-205, 2023 09.
Article in English | MEDLINE | ID: mdl-37756231

ABSTRACT

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. Adult patients (18 years or older) with CP (duration greater than 3 months) who were referred to SPMS from the calendar year 2015-2021 were included (N = 84 829). Results Patients who reported severe anxiety, stress, pain, pain interference, pain catastrophising and severely impaired pain self-efficacy were more likely to seek help from a GP. Patients with longer pain duration had a lower rate of GP visits. The rate of GP visits was 1.22 (IRR = 1.22, 95% CI: 1.19, 1.26) times higher in patients with severe pain severity, compared to patients with mild pain severity. Patients who used opioids were more likely to visit a GP (IRR = 1.32, 95% CI: 1.30, 1.34) than those who were not using opioids. Discussions More than half of the adult CP patients had greater than three GP visits in the 3 months before referral. This study would indicate that some patients may attend their GP to seek an opioid prescription. Given the rising use of opioids nationally, future study is required on opioid users' GP visitation practices. Additionally, the inverse association between pain duration and the rate of GP visits warrants further exploration.


Subject(s)
Chronic Pain , General Practitioners , Adult , Humans , Chronic Pain/therapy , Analgesics, Opioid , Australia , Prescriptions
3.
Front Plant Sci ; 14: 1166226, 2023.
Article in English | MEDLINE | ID: mdl-37265639

ABSTRACT

Introduction: Unlike monocots and dicots, many conifers, particularly Pinaceae, 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, nc, varies substantially within species, both in clonal cultures and in seed embryos. nc variability reflects embryo size variability, with larger diameter embryos having higher nc. Correcting for growth during embryo development, we extract values for the whorl radius at each nc. This radius, corresponding to the spatial pattern of cotyledon differentiation factors, varies over three-fold for the naturally observed range of nc. The current work focuses on factors in the patterning mechanism that could produce such a broad variability in whorl radius. Molecularly, work in Arabidopsis has shown that the initiation zone for leaf primordia occurs at a minimum between inhibitor zones of HD-ZIP III at the shoot apical meristem (SAM) tip and KANADI (KAN) encircling this farther from the tip. PIN1-auxin dynamics within this uninhibited ring form auxin maxima, specifying primordia initiation sites. A similar mechanism is indicated in conifer embryos by effects on cotyledon formation with overexpression of HD-ZIP III inhibitors and by interference with PIN1-auxin patterning. Methods: We develop a mathematical model for HD-ZIP III/KAN spatial localization and use this to characterize the molecular regulation that could generate (a) the three-fold whorl radius variation (and associated nc variability) observed in conifer cotyledon development, and (b) the HD-ZIP III and KAN shifts induced experimentally in conifer embryos and in Arabidopsis. Results: This quantitative framework indicates the sensitivity of mechanism components for positioning lateral organs closer to or farther from the tip. Positional shifting is most readily driven by changes to the extent of upstream (meristematic) patterning and changes in HD-ZIP III/KAN mutual inhibition, and less efficiently driven by changes in upstream dosage or the activation of HD-ZIP III. Sharper expression boundaries can also be more resistant to shifting than shallower expression boundaries. Discussion: The strong variability seen in conifer nc (commonly from 2 to 10) may reflect a freer variation in regulatory interactions, whereas monocot (nc = 1) and dicot (nc = 2) development may require tighter control of such variation. These results provide direction for future quantitative experiments on the positional control of lateral organ initiation, and consequently on plant phyllotaxy and architecture.

4.
Front Pain Res (Lausanne) ; 4: 1153001, 2023.
Article in English | MEDLINE | ID: mdl-37139341

ABSTRACT

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.

5.
PLoS One ; 16(8): e0244701, 2021.
Article in English | MEDLINE | ID: mdl-34411119

ABSTRACT

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. Confocal microscope images of whole early embryos, stained for bcd mRNA or the Staufen (Stau) protein involved in its transport, were processed to extract quantitative AP intensity profiles at two depths (apical-under the embryo surface but above the nuclear layer; and basal-below the nuclei). Each profile was quantified by a two- (or three-) exponential equation. The parameters of these equations were used to analyze the early developmental dynamics of bcd. Analysis of 1D profiles was compared with 2D intensity surfaces from the same images. This approach reveals strong early changes in bcd and Stau, which appear to be coordinated. We can unambiguously discriminate three stages in early development using the exponential parameters: pre-blastoderm (1-9 cleavage cycle, cc), syncytial blastoderm (10-13 cc) and cellularization (from 14A cc). Key features which differ in this period are how fast the first exponential (anterior component) of the apical profile drops with distance and whether it is higher or lower than the basal first exponential. We can further discriminate early and late embryos within the pre-blastoderm stage, depending on how quickly the anterior exponential drops. This relates to the posterior-wards spread of bcd in the first hour of development. Both bcd and Stau show several redistributions in the head cytoplasm, quite probably related to nuclear activity: first shifting inwards towards the core plasm, forming either protrusions (early pre-blastoderm) or round aggregations (early nuclear cleavage cycles, cc, 13 and 14), then moving to the embryo surface and spreading posteriorly. These movements are seen both with the 2D surface study and the 1D profile analysis. The continued spreading of bcd can be tracked from the time of nuclear layer formation (later pre-blastoderm) to the later syncytial blastoderm stages by the progressive loss of steepness of the apical anterior exponential (for both bcd and Stau). Finally, at the beginning of cc14 (cellularization stage) we see a distinctive flip from the basal anterior gradient being higher to the apical gradient being higher (for both bcd and Stau). Quantitative analysis reveals substantial (and correlated) bcd and Stau redistributions during early development, supporting that the distribution and dynamics of bcd mRNA are key factors in the formation and maintenance of the Bcd protein morphogenetic gradient. This analysis reveals the complex and dynamic nature of bcd redistribution, particularly in the head cytoplasm. These resemble observations in oogenesis; their role and significance have yet to be clarified. The observed co-localization during redistribution of bcd and Stau may indicate the involvement of active transport.


Subject(s)
Drosophila/genetics , Animals , Body Patterning/genetics , Cell Nucleus/genetics , Cytoplasm/genetics , Drosophila Proteins/genetics , Embryo, Nonmammalian/physiology , Embryonic Development/genetics , Homeodomain Proteins/genetics , Morphogenesis/genetics , RNA, Messenger/genetics , RNA-Binding Proteins/genetics
6.
J Comput Biol ; 25(11): 1220-1230, 2018 11.
Article in English | MEDLINE | ID: mdl-30117746

ABSTRACT

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. New, more accurate techniques for visualizing bcd mRNA need to be combined with quantitative signal extraction techniques to reconstruct the bcd mRNA distribution. Here, we present a robust technique for quantifying gradients with a two-exponential model. This approach (1) has natural, biologically relevant parameters and (2) is invariant to linear transformations of the data arising due to variation in experimental conditions (e.g., microscope settings, nonspecific background signal). This allows us to quantify bcd mRNA gradient variability from embryo to embryo (important for studying the robustness of developmental regulatory networks); sort out atypical gradients; and classify embryos to developmental stage by quantitative gradient parameters.


Subject(s)
Drosophila Proteins/genetics , Drosophila melanogaster/genetics , Embryo, Nonmammalian/metabolism , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Models, Theoretical , RNA, Messenger/genetics , Trans-Activators/genetics , Animals , Drosophila melanogaster/embryology , Embryo, Nonmammalian/cytology , Morphogenesis , RNA, Messenger/metabolism
7.
Ann Bot ; 121(3): 525-534, 2018 03 05.
Article in English | MEDLINE | ID: mdl-29309524

ABSTRACT

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. Polar transport of the hormone auxin affects outgrowth of distinct cotyledons, but not the radial aspect of the whorl or the within-whorl spacing between cotyledons. A quantitative model of plant growth regulator patterning is needed to understand the dynamics of this complex morphogenetic process. Methods: A two-stage reaction-diffusion model is developed for the spatial patterning of growth regulators on the embryo surface, with a radial pattern (P1) constraining the shorter-wavelength cotyledon pattern (P2) to a whorl. These patterns drive three-dimensional (3-D) morphogenesis by catalysing local surface growth. Key Results: Growth driven by P2 generates single whorls across the experimentally observed range of two to 11 cotyledons, as well as the circularly symmetric response to auxin transport interference. These computations are the first corroboration of earlier theoretical proposals for hierarchical control of whorl formation. The model generates the linear relationship between cotyledon number and embryo diameter observed experimentally. This accounts for normal integer cotyledon number selection, as well as the less common cotyledon fusings and splittings observed experimentally. Flattening of the embryo during development may affect the upward outgrowth angle of the cotyledons. Conclusions: Cotyledon morphogenesis is more complex geometrically in conifers than in angiosperms, involving 2-D patterning which deforms a surface in three dimensions. This work develops a quantitative framework for understanding the growth and patterning dynamics involved in conifer cotyledon development, and applies more generally to the morphogenesis of whorls with many primordia.


Subject(s)
Cotyledon/growth & development , Pinaceae/growth & development , Cotyledon/anatomy & histology , Imaging, Three-Dimensional , Models, Biological , Pinaceae/anatomy & histology , Seeds/anatomy & histology , Seeds/growth & development
8.
PLoS One ; 12(4): e0176228, 2017.
Article in English | MEDLINE | ID: mdl-28437444

ABSTRACT

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. We developed a stochastic model of the spatial and temporal expression of eve stripe 2 (binding by transcriptional activators (Bicoid and Hunchback proteins) and repressors (Giant and Krüppel proteins), transcriptional initiation and termination; with all rate parameters constrained by features of the experimental data) in order to analyze the noisy experimental time series and test hypotheses for how eve transcription is regulated. These include whether eve transcription is simply OFF or ON, with a single ON rate, or whether it proceeds by a more complex mechanism, with multiple ON rates. We find that both mechanisms can produce long (multi-minute) RNA bursts, but that the short-time (minute-to-minute) statistics of the data is indicative of eve being transcribed with at least two distinct ON rates, consistent with data on the joint activation of eve by Bicoid and Hunchback. We also predict distinct statistical signatures for cases in which eve is repressed (e.g. along the edges of the stripe) vs. cases in which activation is reduced (e.g. by mutagenesis of transcription factor binding sites). Fundamental developmental processes such as gene transcription are intrinsically noisy; our approach presents a new way to quantify and analyze time series data during developmental patterning in order to understand regulatory mechanisms and how they propagate noise and impact embryonic robustness.


Subject(s)
Drosophila Proteins/genetics , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Transcription Factors/genetics , Transcription, Genetic , Animals , Drosophila/genetics , Genes, Insect
9.
J Bioinform Comput Biol ; 14(2): 1641005, 2016 04.
Article in English | MEDLINE | ID: mdl-27122317

ABSTRACT

Gene network simulations are increasingly used to quantify mutual gene regulation in biological tissues. These are generally based on linear interactions between single-entity regulatory and target genes. Biological genes, by contrast, commonly have multiple, partially independent, cis-regulatory modules (CRMs) for regulator binding, and can produce variant transcription and translation products. We present a modeling framework to address some of the gene regulatory dynamics implied by this biological complexity. Spatial patterning of the hunchback (hb) gene in Drosophila development involves control by three CRMs producing two distinct mRNA transcripts. We use this example to develop a differential equations model for transcription which takes into account the cis-regulatory architecture of the gene. Potential regulatory interactions are screened by a genetic algorithms (GAs) approach and compared to biological expression data.


Subject(s)
DNA-Binding Proteins/genetics , Drosophila Proteins/genetics , Drosophila/genetics , Gene Expression Regulation, Developmental , Models, Genetic , Transcription Factors/genetics , Animals , Drosophila/embryology , Embryo, Nonmammalian , Promoter Regions, Genetic
10.
Biomed Res Int ; 2015: 986436, 2015.
Article in English | MEDLINE | ID: mdl-26495320

ABSTRACT

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). In addition, the cells or nuclei being imaged are irregularly arranged in 3D space. This makes the processing, extraction, and study of expression signals and intrinsic biological noise a serious challenge for 3D data, requiring new computational approaches. Here, we present a new approach for studying gene expression in nuclei located in a thick layer around a spherical surface. The method includes depth equalization on the sphere, flattening, interpolation to a regular grid, pattern extraction by Shaped 3D singular spectrum analysis (SSA), and interpolation back to original nuclear positions. The approach is demonstrated on several examples of gene expression in the zebrafish egg (a model system in vertebrate development). The method is tested on several different data geometries (e.g., nuclear positions) and different forms of gene expression patterns. Fully 3D datasets for developmental gene expression are becoming increasingly available; we discuss the prospects of applying 3D-SSA to data processing and analysis in this growing field.


Subject(s)
Embryo, Mammalian/metabolism , Gene Expression Profiling/methods , Gene Expression Regulation, Developmental/physiology , Microscopy, Fluorescence/methods , Zebrafish/embryology , Zebrafish/metabolism , Animals , Embryo, Mammalian/embryology , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Fluorescence/methods
11.
Psychiatr Danub ; 27 Suppl 1: S136-42, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26417749

ABSTRACT

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. Above and beyond its utility in pedagogy, film also has the power to heal and the term cinematherapy has been coined to reflect this. Indeed, there are case studies of people with first-hand experience of psychopathology who report that watching films with a mental illness theme has contributed to their recovery. We provide a first person narrative from an individual with schizophrenia in which he expounds on the concepts of cinematherpy and metaphorical imagery in films which theme on psychosis.


Subject(s)
Education, Medical, Undergraduate/methods , Mental Disorders/psychology , Mental Disorders/therapy , Motion Pictures , Psychiatry/education , Psychotherapy/education , Adult , Curriculum , Humans , Male , Psychopathology/education , Schizophrenia, Paranoid/psychology , Schizophrenia, Paranoid/therapy , Self Care/psychology
12.
Biomed Res Int ; 2015: 689745, 2015.
Article in English | MEDLINE | ID: mdl-25945341

ABSTRACT

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. These extensions, circular and shaped 2D-SSA, are applied to gene expression in the nuclear layer just under the surface of the Drosophila (fruit fly) embryo. We consider the commonly used cylindrical projection of the ellipsoidal Drosophila embryo. We demonstrate how circular and shaped versions of 2D-SSA help to decompose expression data into identifiable components (such as trend and noise), as well as separating signals from different genes. Detection and improvement of under- and overcorrection in multichannel imaging is addressed, as well as the extraction and analysis of 3D features in 3D gene expression patterns.


Subject(s)
Drosophila Proteins/biosynthesis , Drosophila melanogaster/genetics , Embryonic Development/genetics , Gene Expression Regulation, Developmental , Animals , Drosophila melanogaster/growth & development , Embryo, Nonmammalian , Gene Expression Profiling , Imaging, Three-Dimensional , Spectrum Analysis
13.
Inf Sci (N Y) ; 306: 88-110, 2015 Jun 10.
Article in English | MEDLINE | ID: mdl-25767296

ABSTRACT

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. We believe that a vital direction in this field must be algorithms that model the activity of "genomic parasites", such as transposons, in biological evolution. Many evolutionary biologists posit that it is the co-evolution of populations with their genomic parasites that permits the high efficiency of evolutionary searches found in the living world. This publication is our first step in the direction of developing a minimal assortment of algorithms that simulate the role of genomic parasites. Specifically, we started in the domain of genetic algorithms (GA) and selected the Artificial Ant Problem as a test case. This navigation problem is widely known as a classical benchmark test and possesses a large body of literature. We add new objects to the standard toolkit of GA - artificial transposons and a collection of operators that operate on them. We define these artificial transposons as a fragment of an ant's code with properties that cause it to stand apart from the rest. The minimal set of operators for transposons is a transposon mutation operator, and a transposon reproduction operator that causes a transposon to multiply within the population of hosts. An analysis of the population dynamics of transposons within the course of ant evolution showed that transposons are involved in the processes of propagation and selection of blocks of ant navigation programs. During this time, the speed of evolutionary search increases significantly. We concluded that artificial transposons, analogous to real transposons, are truly capable of acting as intelligent mutators that adapt in response to an evolutionary problem in the course of co-evolution with their hosts.

14.
PLoS One ; 10(3): e0118450, 2015.
Article in English | MEDLINE | ID: mdl-25793381

ABSTRACT

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. As a transcriptional regulator for a number of downstream genes, the spatial precision of hb expression can have significant effects in the development of the body plan. To investigate the factors contributing to hb precision, we used fine spatial and temporal resolution data to develop a quantitative model for the regulation of hb expression in the mid-embryo. In particular, modelling hb pattern refinement in mid nuclear cleavage cycle 14 (NC14) reveals some of the regulatory contributions of simultaneously-expressed gap genes. Matching the model to recent data from wild-type (WT) embryos and mutants of the gap gene Krüppel (Kr) indicates that a mid-embryo Hb concentration peak important in thoracic development (at parasegment 4, PS4) is regulated in a dual manner by Kr, with low Kr concentration activating hb and high Kr concentration repressing hb. The processes of gene expression (transcription, translation, transport) are intrinsically random. We used stochastic simulations to characterize the noise generated in hb expression. We find that Kr regulation can limit the positional variability of the Hb mid-embryo border. This has been recently corroborated in experimental comparisons of WT and Kr- mutant embryos. Further, Kr regulation can decrease uncertainty in mid-embryo hb expression (i.e. contribute to a smooth Hb boundary) and decrease between-copy transcriptional variability within nuclei. Since many tissue boundaries are first established by interactions between neighbouring gene expression domains, these properties of Hb-Kr dynamics to diminish the effects of intrinsic expression noise may represent a general mechanism contributing to robustness in early development.


Subject(s)
Body Patterning , DNA-Binding Proteins/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Embryo, Nonmammalian/metabolism , Kruppel-Like Transcription Factors/metabolism , Transcription Factors/metabolism , Animals , Cell Nucleus/metabolism , Models, Biological , Protein Binding , Stochastic Processes , Transcription, Genetic
16.
J Bioinform Comput Biol ; 12(2): 1441009, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24712536

ABSTRACT

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. Both how modularity evolved and what function it serves are open questions. We present a computational model for the cis-regulation of the hunchback (hb) gene in the fruit fly (Drosophila). We simulate evolution (using an evolutionary computation approach from computer science) to find the optimal cis-regulatory arrangements for fitting experimental hb expression patterns. We find that the cis-regulatory region tends to readily evolve modularity. These cis-regulatory modules (CRMs) do not tend to control single spatial domains, but show a multi-CRM/multi-domain correspondence. We find that the CRM-domain correspondence seen in Drosophila evolves with a high probability in our model, supporting the biological relevance of the approach. The partial redundancy resulting from multi-CRM control may confer some biological robustness against corruption of regulatory sequences. The technique developed on hb could readily be applied to other multi-CRM developmental genes.


Subject(s)
DNA-Binding Proteins/genetics , Drosophila Proteins/genetics , Drosophila/growth & development , Drosophila/genetics , Gene Expression Regulation, Developmental/genetics , Regulatory Elements, Transcriptional/genetics , Regulatory Sequences, Nucleic Acid/genetics , Transcription Factors/genetics , Animals , Base Sequence , Evolution, Molecular , Molecular Sequence Data
17.
Article in English | MEDLINE | ID: mdl-24319503

ABSTRACT

A central question in evolutionary biology concerns the transition between discrete numbers of units (e.g. vertebrate digits, arthropod segments). How do particular numbers of units, robust and characteristic for one species, evolve into another number for another species? Intermediate phases with a diversity of forms have long been theorized, but these leave little fossil or genomic data. We use evolutionary computations (EC) of a gene regulatory network (GRN) model to investigate how embryonic development is altered to create new forms. The trajectories are epochal and non-smooth, in accord with both the observed stability of species and the evolvability between forms.

18.
Bull Math Biol ; 75(12): 2346-71, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24072659

ABSTRACT

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. Parameters for the Brusselator in spherical cap domains can be chosen to give supercritical pitchfork bifurcations of patterned solutions of the nonlinear reaction-diffusion system that correspond to the cotyledon patterns that appear on the flattening tips of conifer embryos.


Subject(s)
Models, Biological , Plant Development , Body Patterning , Computational Biology , Mathematical Concepts , Plants/embryology
19.
Methods ; 62(1): 39-55, 2013 Jul 15.
Article in English | MEDLINE | ID: mdl-23726941

ABSTRACT

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. Such work can generally be termed evolution in silico. Complementary to these biologically-focused approaches, a now well-established field of computer science is Evolutionary Computations (ECs), in which highly efficient optimization techniques are inspired from evolutionary principles. In surveying biological simulation approaches, we discuss the considerations that must be taken with respect to: (a) the precision and completeness of the data (e.g. are the simulations for very close matches to anatomical data, or are they for more general exploration of evolutionary principles); (b) the level of detail to model (we proceed from 'coarse-grained' evolution of simple gene-gene interactions to 'fine-grained' evolution at the DNA sequence level); (c) to what degree is it important to include the genome's cellular context; and (d) the efficiency of computation. With respect to the latter, we argue that developments in computer science EC offer the means to perform more complete simulation searches, and will lead to more comprehensive biological predictions.


Subject(s)
Drosophila Proteins/genetics , Drosophila melanogaster/genetics , Evolution, Molecular , Gene Regulatory Networks , Genes, Insect , Models, Genetic , Algorithms , Animals , Body Patterning/genetics , Computer Simulation , Drosophila Proteins/metabolism , Drosophila melanogaster/growth & development , Drosophila melanogaster/metabolism , Embryo, Nonmammalian , Epistasis, Genetic , Gene Expression Regulation, Developmental
20.
Am J Cardiol ; 112(3): 430-5, 2013 Aug 01.
Article in English | MEDLINE | ID: mdl-23668639

ABSTRACT

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. Transfers were accomplished by the institutional critical care transfer system using ground ambulance (n = 47), helicopter (n = 196), or fixed-wing jet (n = 20) from referring centers directly to the coronary care unit, bypassing the emergency department. The transfer mortality rate was 0%, and the in-hospital mortality rate was 9% (n = 23). Initial systolic blood pressure and heart rate at the time of arrival of the transfer team to the referring hospital were compared with those on arrival to the coronary care unit. The median transfer distance was 66 km (interquartile range 24 to 119), and the median transfer time was 87 minutes (interquartile range 67 to 114). The transfer team achieved significant reductions in systolic blood pressure (from 142 ± 29 to 132 ± 23 mm Hg) (mean difference in systolic blood pressure 10 mm Hg, 95% confidence interval 7 to 14, p <0.0001) and heart rate (from 78 ± 16 to 75 ± 16 beats/min) (mean difference in heart rate 3 beats/min, 95% confidence interval 1 to 4, p <0.0001). In conclusion, these results indicate that patients with AAS can be safely transferred to specialized centers for definitive treatment, and a well-trained critical care transfer team can actively continue to optimize medical management during transit.


Subject(s)
Aortic Diseases/physiopathology , Aortic Diseases/surgery , Emergency Medical Services , Patient Safety , Patient Transfer , Acute Disease , Aged , Aortic Diseases/mortality , Blood Pressure/physiology , Comorbidity , Coronary Care Units , Critical Care , Female , Heart Rate/physiology , Hospital Mortality , Humans , Male , Middle Aged , Syndrome
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