scholarly journals Seeing the green cucumber: Reflections on variation theory and teaching plant identification

2021 ◽  
Author(s):  
Dawn Sanders ◽  
Bente Eriksen ◽  
Catherine MacHale Gunnarsson ◽  
Jonas Emanuelsson
Keyword(s):  
Variation Theory ◽  
Plant Identification

ERRORS ASSOCIATED WITH HERBAGE DISSECTION ANALYSES 2. Problems of species identification

1976 ◽  
pp. 213-225
Author(s):  
I.M. Ritchie ◽  
C.C. Boswell ◽  
A.M. Badland
Keyword(s):  
New Zealand ◽  
Dry Weight ◽  
Analytical Tool ◽  
Species Level ◽  
Weight Basis ◽  
Plant Identification ◽  
Leaf Fragment ◽  
Research Division ◽  
Or Groups ◽  
Botanical Analysis

HERBACE DISSECTION is the process in which samples of herbage cut from trials are separated by hand into component species. Heavy reliance is placed on herbage dissection as an analytical tool ,in New Zealand, and in the four botanical analysis laboratories in the Research Division of the Ministry of Agriculture and Fisheries about 20 000 samples are analysed each year. In the laboratory a representative subsample is taken by a rigorous quartering procedure until approximately 400 pieces of herbage remain. Each leaf fragment is then identified to species level or groups of these as appropriate. The fractions are then dried and the composition calculated on a percentage dry weight basis. The accuracy of the analyses of these laboratories has been monitored by a system of interchanging herbage dissection samples between them. From this, the need to separate subsampling errors from problems of plant identification was, appreciated and some of this work is described here.

Rosen-Chambers Variation Theory of Linearly-Damped Classic and Quantum Oscillator

2014 ◽  
Vol 4 (1) ◽  
pp. 404-426
Author(s):  
Vincze Gy. Szasz A.
Keyword(s):  
Harmonic Oscillator ◽  
Classical Mechanics ◽  
Universal Time ◽  
Variation Theory ◽  
Quantum Oscillator ◽  
Variation Principle ◽  
Poisson Brackets ◽  
Mathematical Meaning ◽  
Damped Harmonic Oscillator ◽  
Damped Oscillator

Phenomena of damped harmonic oscillator is important in the description of the elementary dissipative processes of linear responses in our physical world. Its classical description is clear and understood, however it is not so in the quantum physics, where it also has a basic role. Starting from the Rosen-Chambers restricted variation principle a Hamilton like variation approach to the damped harmonic oscillator will be given. The usual formalisms of classical mechanics, as Lagrangian, Hamiltonian, Poisson brackets, will be covered too. We shall introduce two Poisson brackets. The first one has only mathematical meaning and for the second, the so-called constitutive Poisson brackets, a physical interpretation will be presented. We shall show that only the fundamental constitutive Poisson brackets are not invariant throughout the motion of the damped oscillator, but these show a kind of universal time dependence in the universal time scale of the damped oscillator. The quantum mechanical Poisson brackets and commutation relations belonging to these fundamental time dependent classical brackets will be described. Our objective in this work is giving clearer view to the challenge of the dissipative quantum oscillator.

Author response for "How citizen scientists contribute to monitor protected areas thanks to automatic plant identification tools"

2020 ◽  
Author(s):  
Pierre Bonnet ◽  
Alexis Joly ◽  
Jean‐Michel Faton ◽  
Susan Brown ◽  
David Kimiti ◽  
...  
Keyword(s):  
Protected Areas ◽  
Author Response ◽  
Plant Identification

Author response for "How citizen scientists contribute to monitor protected areas thanks to automatic plant identification tools"

2020 ◽  
Author(s):  
Pierre Bonnet ◽  
Alexis Joly ◽  
Jean‐Michel Faton ◽  
Susan Brown ◽  
David Kimiti ◽  
...  
Keyword(s):  
Protected Areas ◽  
Author Response ◽  
Plant Identification

Does high-variation training facilitate transfer of training in paediatric transthoracic echocardiography?

2020 ◽  
pp. 1-7
Author(s):  
Colin J. McMahon ◽  
Sarah Gallagher ◽  
Adam James ◽  
Aoife Deery ◽  
Mark Rhodes ◽  
...  
Keyword(s):  
Transfer Of Training ◽  
Assessment Tool ◽  
Qualitative Interviews ◽  
Training Group ◽  
Variation Theory ◽  
Cardiac Lesion ◽  
Cumulative Score ◽  
Hands On ◽  
Performance Report ◽  
Technical Proficiency

Abstract Background: Factors that facilitate transfer of training in paediatric echocardiography remain poorly understood. This study assessed whether high-variation training facilitated successful transfer in paediatric echocardiography. Methods: A mixed-methods study of transfer of technical and interpretive skill application amongst postgraduate trainees. Trainees were randomised to a low or high-variation training group. After a period of 8 weeks intensive echocardiography training, we video-recorded how trainees completed an echocardiogram in a complex cardiac lesion not previously encountered. Blinded quantitative analysis and scoring of trainee performance (echocardiogram performance, report, and technical proficiency) were performed using a validated assessment tool by a blinded cardiologist and senior cardiac physiologist. Qualitative interviews of the trainees were recorded to ascertain trainee experiences during the training and transfer process. Results: Sixteen trainees were enrolled in the study. For the cumulative score for all three components tested (echocardiogram performance, report, and technical proficiency), χ2 = 8.223, p = .016, which showed the high-variation group outperformed the low-variation group. Two common themes which assisted in the transfer emerged from interviews are as follows: (1) use of strategies described in variation theory to describe abnormal hearts, (2) the use of formative live feedback from trainers during hands-on training. Conclusion: Training strategies exposing trainees to high-variation training may aid transfer of paediatric echocardiography skills.

scholarly journals Designing Tasks for a Dynamic Online Environment: Applying Research into Students’ Difficulties with Linear Equations

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 557
Author(s):  
Morten Elkjær ◽  
Uffe Thomas Jankvist
Keyword(s):  
Design Theory ◽  
Teaching And Learning ◽  
Linear Equations ◽  
Task Design ◽  
Tree Structure ◽  
Learning Trajectory ◽  
Variation Theory ◽  
Online Environment ◽  
School Students ◽  
Personalised Learning

Despite almost half a century of research into students’ difficulties with solving linear equations, these difficulties persist in everyday mathematics classes around the world. Furthermore, the difficulties reported decades ago are the same ones that persist today. With the immense number of dynamic online environments for mathematics teaching and learning that are emerging today, we are presented with a perhaps unique opportunity to do something about this. This study sets out to apply the research on lower secondary school students’ difficulties with equation solving, in order to eventually inform students’ personalised learning through a specific task design in a particular dynamic online environment (matematikfessor.dk). In doing so, task design theory is applied, particularly variation theory. The final design we present consists of eleven general equation types—ten types of arithmetical equations and one type of algebraic equation—and a broad range of variations of these, embedded in a potential learning-trajectory-tree structure. Besides establishing this tree structure, the main theoretical contribution of the study and the task design we present is the detailed treatment of the category of arithmetical equations, which also involves a new distinction between simplified and non-simplified arithmetical equations.

Population Subdivision and Molecular Sequence Variation: Theory and Analysis of Drosophila ananassae Data

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1385-1395
Author(s):  
Claus Vogl ◽  
Aparup Das ◽  
Mark Beaumont ◽  
Sujata Mohanty ◽  
Wolfgang Stephan
Keyword(s):  
Sequence Data ◽  
Isolation By Distance ◽  
Allele Frequencies ◽  
Drosophila Ananassae ◽  
Population Subdivision ◽  
Variation Theory ◽  
Peripheral Populations ◽  
Molecular Variation ◽  
Data Set ◽  
Evolutionary Forces

Abstract Population subdivision complicates analysis of molecular variation. Even if neutrality is assumed, three evolutionary forces need to be considered: migration, mutation, and drift. Simplification can be achieved by assuming that the process of migration among and drift within subpopulations is occurring fast compared to mutation and drift in the entire population. This allows a two-step approach in the analysis: (i) analysis of population subdivision and (ii) analysis of molecular variation in the migrant pool. We model population subdivision using an infinite island model, where we allow the migration/drift parameter 0398; to vary among populations. Thus, central and peripheral populations can be differentiated. For inference of 0398;, we use a coalescence approach, implemented via a Markov chain Monte Carlo (MCMC) integration method that allows estimation of allele frequencies in the migrant pool. The second step of this approach (analysis of molecular variation in the migrant pool) uses the estimated allele frequencies in the migrant pool for the study of molecular variation. We apply this method to a Drosophila ananassae sequence data set. We find little indication of isolation by distance, but large differences in the migration parameter among populations. The population as a whole seems to be expanding. A population from Bogor (Java, Indonesia) shows the highest variation and seems closest to the species center.

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