scholarly journals Decoding the gene co-expression network underlying the ability of Gevuina avellana Mol. to live in diverse light conditions

2017 ◽  
Author(s):  
E Ostria-Gallardo ◽  
A Ranjan ◽  
Y Ichihashi ◽  
LJ Corcuera ◽  
NR Sinha
Keyword(s):  
Carbon Assimilation ◽  
Photosynthetic Performance ◽  
Light Energy ◽  
Photosynthetic Parameters ◽  
List Type ◽  
Light Conditions ◽  
Photochemical Process ◽  
Gevuina Avellana ◽  
Wide Range ◽  
Photosynthetic Responses

SummaryGevuina avellana Mol. (Proteaceae) is a typical tree from the South American temperate rainforest. Although this species mostly regenerates in shaded understories, it exhibits an exceptional ecological breadth, being able to live under a wide range of light conditions. Here we studied the genetic basis regulating physiological acclimation of the photosynthetic responses of G. avellana under contrasting light conditions.We analyzed carbon assimilation and light energy used for photochemical process in plants acclimated to contrasting light conditions. Also, we used a transcriptional profile of leaf primordia from G. avellana saplings growing under different light environments to identify the gene co-expression network underpinning photosynthetic performance and light-related processes.The photosynthetic parameters revealed optimal performance regardless of light conditions. Strikingly, the mechanism involved in dissipation of excess light energy showed no significant differences between high and low-light acclimated plants. The gene co-expression network defined a community structure consistent with the photochemical responses, including genes involved mainly in assembly and functioning of photosystems, photoprotection, and retrograde signaling.Our ecophysiological genomics approach provides an understanding of the molecular regulatory mechanisms that allows this tree to have an optimal balance between photochemical, photoprotective and antioxidant performance in the diverse light habitats it encounters in nature.

Photosynthetic potential of sun and shade Viola species

1984 ◽  
Vol 62 (6) ◽  
pp. 1273-1278 ◽  
Author(s):  
William F. Curtis
Keyword(s):  
Dark Respiration ◽  
Photosynthetic Performance ◽  
Light Conditions ◽  
Low Light ◽  
Light Regimes ◽  
Photosynthetic Plasticity ◽  
Photosynthetic Potential ◽  
Photosynthetic Responses ◽  
Sun And Shade ◽  
Meadow Species

The photosynthetic responses of a forest floor violet (Viola blanda) and a related meadow species (Viola flmbriatula) grown under controlled conditions were measured to test the prediction that these two species were photosynthetically shade and sun adapted, respectively. Based on their low photosynthetic and dark respiration rates, and low light saturation and compensation points, both violets can be classified as shade-tolerant. The forest species was photosynthetically and morphologically inflexible when grown under high light conditions, which led to chlorosis and greatly decreased photosynthetic performance. Conversely, the meadow species was both photosynthetically and morphologically flexible; its photosynthetic performance allowed it to grow well under both high and low light regimes. As a consequence, morphological flexibility may play a greater role than physiological (i.e., photosynthetic) plasticity in regulating the distribution of these two violets under field conditions.

scholarly journals Gas exchange in young Hevea brasiliensis (Willd. Ex A. Juss.) Müll. Arg. (Euphorbiaceae) plants in Antioquia (Colombia)

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Oscar De Jesús Cordoba Gaona ◽  
Danilo Augusto Monsalve-García ◽  
Juan David Hernández-Arredondo ◽  
Juan José Guerra-Hincapié ◽  
Juan Pablo Gil-Restrepo ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Performance Studies ◽  
Hevea Brasiliensis ◽  
Area Under The Curve ◽  
Photosynthetic Performance ◽  
Light Energy ◽  
Carbon Accumulation ◽  
Photosynthetic Parameters ◽  
Energy Investment ◽  
Net Assimilation

The aim of this study was to determine the behavior of the rubber plant Hevea brasiliensis regarding its photosynthetic performance in the rubber producer regions in Nordeste and Bajo Cauca, in the department of Antioquia, Colombia, as a baseline for future clonal performance studies among environments. Gas exchange was recorded using a portable infrared gas analyzer, and for the photosynthetic parameters for seven genotypes (clones) a medium value was calculated and was later used to estimate the area under the curve. The maximum photosynthetic value was reached at 8:00 hours in San Roque (10.97 µmol [CO2] m-2s-1) and at 9:00 hours in Caucasia (7.84 µmol [CO2] m-2s-1). Maximum transpiration was 3.55 mmol [H2O] m-2s-1 in San Roque and 5.16 mmol [H2O] m-2s-1 in Caucasia, while the maximum stomatal conductance was 0.18 mol [CO2] m-2s-1 and 0.16 mol [CO2] m-2s-1 in San Roque and Caucasia, respectively. The rubber plants in Caucasia had a higher accumulated net assimilation rate (271,934 µmol [CO2] m-2day-1) than what was found in San Roque (226,287 µmol [CO2] m-2day-1), showing a difference of 45.647,52 µmol [CO2] m-2day-1. The highest carbon accumulation with the lowest light energy investment (697,638 µmol [CO2] µmol [photon]-1day1) was found in San Roque. Therefore, regarding gas exchange and the use of light energy Hevea brasiliensis showed greater environmental adaptation in San Roque.

scholarly journals Recent advances in understanding photosynthesis

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2890 ◽  
Author(s):  
Ulf-Ingo Flügge ◽  
Peter Westhoff ◽  
Dario Leister
Keyword(s):  
Canopy Structure ◽  
Carbon Assimilation ◽  
Energy Conversion Efficiency ◽  
Photosynthetic Performance ◽  
Light Energy ◽  
World Population ◽  
Light Energy Conversion ◽  
Life On Earth ◽  
Source Sink ◽  
Made In

Photosynthesis is central to all life on earth, providing not only oxygen but also organic compounds that are synthesized from atmospheric CO2and water using light energy as the driving force. The still-increasing world population poses a serious challenge to further enhance biomass production of crop plants. Crop yield is determined by various parameters,inter aliaby the light energy conversion efficiency of the photosynthetic machinery. Photosynthesis can be looked at from different perspectives: (i) light reactions and carbon assimilation, (ii) leaves and canopy structure, and (ii) source-sink relationships. In this review, we discuss opportunities and prospects to increase photosynthetic performance at the different layers, taking into account the recent progress made in the respective fields.

Coupling mixing and photophysiological response of Antarctic plankton: a Lagrangian approach

2004 ◽  
Vol 16 (2) ◽  
pp. 133-142 ◽  
Author(s):  
DANIELA CIANELLI ◽  
MAURIZIO RIBERA D'ALCALÀ ◽  
VINCENZO SAGGIOMO ◽  
ENRICO ZAMBIANCHI
Keyword(s):  
Ross Sea ◽  
Photosynthetic Performance ◽  
Strong Mixing ◽  
Vertical Position ◽  
Photosynthetic Parameters ◽  
Wide Range ◽  
The Individual ◽  
The Antarctic

An individual-based model is presented which describes the spatial and temporal evolution of phytoplankton growth in terms of a Lagrangian ensemble of cells affected by various physical and biological forcing factors. The motion of cells develops according to a turbulent velocity field which simulates the Antarctic mixed layer during the summer. The cell growth is a function of the irradiance regime, nutrient availability and the vertical position of the individual with respect to the other cells (in order to evaluate the self-shading effect). The values of photosynthetic parameters used to simulate the photophysiological response of the organisms are derived from measurements collected in the Ross Sea. In contrast to previous individual-based descriptions, all the physical and biological processes involved are explicitly reproduced in their dynamical features. Coupling different mixing levels with photoacclimation strategies leads to a wide range of photophysiological responses which underline the role of individual physiological histories in determining the growth of the population as a whole. Simulated photosynthetic parameters, chlorophyll a concentrations and integrated primary production correspond closely to in situ data and confirm that photoacclimation to low irradiance and strong mixing regimes may be considered as crucial factors in the photosynthetic performance of Antarctic phytoplankton.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Triply-periodic nanostructures in surfactant, block copolymer, and biomembrane systems, and simulation of TEMs

1993 ◽  
Vol 51 ◽  
pp. 884-885
Author(s):  
David M. Anderson ◽  
Tomas Landh
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Cubic Phase ◽  
List Type ◽  
Interpenetrating Networks ◽  
Triply Periodic ◽  
Wide Range ◽  
Bicontinuous Cubic ◽  
Phase Liquid ◽  
Dividing Surface

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.

scholarly journals 332 The diagnostic role of shunt series radiographs (SSR) in children presenting to the children’s emergency department (CED) with suspected ventriculoperitoneal (VP) shunt failure

2020 ◽  
Vol 37 (12) ◽  
pp. 852.3-853
Author(s):  
Angharad Griffiths ◽  
Ikechukwu Okafor ◽  
Thomas Beattie
Keyword(s):  
Clinical Outcome ◽  
Sensitivity And Specificity ◽  
Clinical Information ◽  
Flow Diagram ◽  
List Type ◽  
Shunt Failure ◽  
Vp Shunt ◽  
Wide Range ◽  
Diagnostic Role

Aims/Objectives/BackgroundVP shunts are used to drain CSF from the cranial vault because of a wide range of pathologies and, like any piece of hardware, can fail. Traditionally investigations include SSR and CT. This project examines the role of SSR in evaluating children with suspected VP shunt failure.Primary outcome: Sensitivity and specificity of SSR in children presenting to the CED with concern for shunt failure.Methods/DesignConducted in a single centre, tertiary CED of the national Irish Neurosurgical(NS) referral centre (ED attendance:>50,000 patients/year). 100 sequential SSR requested by the CED were reviewed. Clinical information was extracted from electronic requests. Shunt failure was defined by the need for NS intervention(Revision).Abstract 332 Figure 1Abstract 332 Figure 2Results/ConclusionsSensitivity and specificity is presented in figure 1 (two by two table).100 radiographs performed in 84 children.22% shunts revised (see flow diagram).7 SSR’s were abnormal.85% (n=6) shunts revised. [5 following abnormal CT].Of the normal SSR’s; 16 had abnormal CT and revised.85/100 received CT.64 of 85 CT’s (75%) were normal.□6 of the 64 had focal shunt concern.SSR’s shouldn’t be used in isolation. NPV&PPV, Sensitivity&Specificity is low.SSR’s are beneficial where there’s concern over focal shunt problems (injury/pain/swelling) or following abnormal CT.VP shunt failure is not well investigated with SSR alone.SSR’s could be omitted where there is no focal shunt concern/after normal CT (without impacting clinical outcome) reducing radiation exposure and reduce impact on CED’s.59 SSR’s could have been avoided without adverse clinical outcome.

scholarly journals Using Satellite Data for CBRN (Chemical, Biological, Radiological, and Nuclear) Threat Detection, Monitoring, and Modelling

2021 ◽  
Author(s):  
Gary Sutlieff ◽  
Lucy Berthoud ◽  
Mark Stinchcombe
Keyword(s):  
Satellite Data ◽  
Meteorological Data ◽  
Atmospheric Composition ◽  
Chemical Detection ◽  
List Type ◽  
Data Types ◽  
Wide Range ◽  
Future Technologies ◽  
The Impact ◽  
Near Future

Abstract CBRN (Chemical, Biological, Radiological, and Nuclear) threats are becoming more prevalent, as more entities gain access to modern weapons and industrial technologies and chemicals. This has produced a need for improvements to modelling, detection, and monitoring of these events. While there are currently no dedicated satellites for CBRN purposes, there are a wide range of possibilities for satellite data to contribute to this field, from atmospheric composition and chemical detection to cloud cover, land mapping, and surface property measurements. This study looks at currently available satellite data, including meteorological data such as wind and cloud profiles, surface properties like temperature and humidity, chemical detection, and sounding. Results of this survey revealed several gaps in the available data, particularly concerning biological and radiological detection. The results also suggest that publicly available satellite data largely does not meet the requirements of spatial resolution, coverage, and latency that CBRN detection requires, outside of providing terrain use and building height data for constructing models. Lastly, the study evaluates upcoming instruments, platforms, and satellite technologies to gauge the impact these developments will have in the near future. Improvements in spatial and temporal resolution as well as latency are already becoming possible, and new instruments will fill in the gaps in detection by imaging a wider range of chemicals and other agents and by collecting new data types. This study shows that with developments coming within the next decade, satellites should begin to provide valuable augmentations to CBRN event detection and monitoring. Article Highlights There is a wide range of existing satellite data in fields that are of interest to CBRN detection and monitoring. The data is mostly of insufficient quality (resolution or latency) for the demanding requirements of CBRN modelling for incident control. Future technologies and platforms will improve resolution and latency, making satellite data more viable in the CBRN management field

Therapy discontinuation in a primary care psychological service: why patients drop out

2020 ◽  
Vol 13 ◽  
Author(s):  
Aisan Ghaemian ◽  
Mahdi Ghomi ◽  
Miles Wrightman ◽  
Colm Ellis-Nee
Keyword(s):  
Drop Out ◽  
Treatment Withdrawal ◽  
List Type ◽  
Structured Interviews ◽  
Group Settings ◽  
Psychological Therapies ◽  
Psychological Service ◽  
Wide Range ◽  
Key Factor ◽  
Therapy Services

Abstract The present study aimed to explore patients’ experience with an Improving Access to Psychological Therapies (IAPT) service, and to investigate the reasons for discontinuing their treatment. A qualitative approach was adopted using thematic analysis of semi-structured interviews carried out with 818 patients attending for treatment in Talking Change from November 2015 to January 2019, retrospectively. The five main themes that emerged from the study were: ‘Felt better’, ‘Issues with group settings’, ‘Therapeutic alliance breakdown’, ‘Miscommunication’ and ‘Impracticalities’. The qualitative study uncovered a wide range of reasons for people who had dropped out from their treatment. The findings mainly emphasised general dissatisfaction and inconvenient appointments. However, improvement in symptoms of depression and anxiety was also identified as a key factor among patients who discontinued their treatment. This recovery is known as ‘progress withdrawal’ in which patients withdraw from treatment early due to good therapeutic progress. We present clinical and procedural implications arising from these themes. Key learning aims (1) To explore what can cause discontinuation of therapy. (2) To obtain the experience of people who have received treatment and dropped out from Talking Change Psychological Therapy services. (3) To explore whether people recovered as part of the treatment withdrawal and what may have helped towards that recovery.

scholarly journals Does the punishment fit the crime? Consequences and diagnosis of misspecified detection functions in Bayesian spatial capture-recapture modelling

2021 ◽  
Author(s):  
Soumen Dey ◽  
Richard Bischof ◽  
Pierre P. A. Dupont ◽  
Cyril Milleret
Keyword(s):  
Home Range ◽  
Space Use ◽  
Relative Bias ◽  
Diagnostic Tools ◽  
List Type ◽  
Detection Function ◽  
Density Estimates ◽  
Use Patterns ◽  
Wide Range ◽  
Capture Recapture

AbstractSpatial capture-recapture (SCR) is now used widely to estimate wildlife densities. At the core of SCR models lies the detection function, linking individual detection probability to the distance from its latent activity center. The most common function (half-normal) assumes a bivariate normal space use and consequently detection pattern. This is likely an oversimplification and misrepresentation of real-life animal space use patterns, but studies have reported that density estimates are relatively robust to misspecified detection functions. However, information about consequences of such misspecification on space use parameters (e.g. home range area), as well as diagnostic tools to reveal it are lacking.We simulated SCR data under six different detection functions, including the half-normal, to represent a wide range of space use patterns. We then fit three different SCR models, with the three simplest detection functions (half-normal, exponential and half-normal plateau) to each simulated data set. We evaluated the consequences of misspecification in terms of bias, precision and coverage probability of density and home range area estimates. We also calculated Bayesian p-values with respect to different discrepancy metrics to assess whether these can help identify misspecifications of the detection function.We corroborate previous findings that density estimates are robust to misspecifications of the detection function. However, estimates of home range area are prone to bias when the detection function is misspecified. When fitted with the half-normal model, average relative bias of 95% kernel home range area estimates ranged between −25% and 26% depending on the misspecification. In contrast, the half-normal plateau model (an extension of the half-normal) returned average relative bias that ranged between −26% and −4%. Additionally, we found useful heuristic patterns in Bayesian p-values to diagnose the misspecification in detection function.Our analytical framework and diagnostic tools may help users select a detection function when analyzing empirical data, especially when space use parameters (such as home range area) are of interest. We urge development of additional custom goodness of fit diagnostics for Bayesian SCR models to help practitioners identify a wider range of model misspecifications.

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