Automated leaf physiognomic character identification from digital images

Paleobiology ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 528-553 ◽  
Author(s):  
Norman MacLeod ◽  
David Steart
Keyword(s):  
Strong Support ◽  
Identification Accuracy ◽  
Character State ◽  
Local Climate ◽  
Leaf Analysis ◽  
State Identification ◽  
Aspect Ratios ◽  
Point Of Use ◽  
Leaf Character ◽  
Length Width

AbstractResearch into the relationship between leaf form and climate over the last century has revealed that, in many species, the sizes and shapes of leaf characters exhibit highly structured and predictable patterns of variation in response to the local climate. Several procedures have been developed that quantify covariation between the relative abundance of plant character states and the states of climate variables as a means of estimating paleoclimate parameters. One of the most widely used of these is the Climate Leaf Analysis Multivariate Program (CLAMP). The consistency, accuracy and reliability with which leaf characters can be identified and assigned to CLAMP character-state categories is critical to the accuracy of all CLAMP analyses. Here we report results of a series of performance tests for an image-based, fully automated at the point of use, leaf character scoring system that can be used to generate CLAMP leaf character state data for: leaf bases (acute, cordate and round), leaf apices (acute, attenuate), leaf shapes (ovate, elliptical and obovate), leaf lobing (unlobed, lobed), and leaf aspect ratios (length/width). This image-based system returned jackknifed identification accuracy ratios of between 87% and 100%. These results demonstrate that automated image-based identification systems have the potential to improve paleoenvironmental inferences via the provision of accurate, consistent and rapid CLAMP leaf-character identifications. More generally, our results provide strong support for the feasibility of using fully automated, image-based morphometric procedures to address the general problem of morphological character-state identification.

scholarly journals Learning the ““Special Note””: Evidence for a Critical Period for Absolute Pitch Acquisition

2003 ◽  
Vol 21 (1) ◽  
pp. 119-127 ◽  
Author(s):  
FRANK A. RUSSO ◽  
DEBORAH L. WINDELL ◽  
LOLA L. CUDDY
Keyword(s):  
Critical Period ◽  
Strong Support ◽  
Absolute Pitch ◽  
Identification Accuracy ◽  
Single Tone ◽  
The Third

Children (3––6 years old) and adults were trained for 6 weeks to identify a single tone, C5. Test sessions, held at the end of each week, had participants identify C5 within a set of seven alternative tones. By the third week of training, identification accuracy of children 5––6 years old surpassed the accuracies of children 3––4 years old and adults. Combined with an analysis of perceptual strategies, the data provide strong support for a critical period for absolute pitch acquisition. Received July 12, 2003, accepted August 1,2003

scholarly journals Why are SNAREpins rod-shaped?

2021 ◽  
Author(s):  
Jin Zeng ◽  
Zachary McDargh ◽  
Dong An ◽  
Ben O'Shaughnessy
Keyword(s):  
Membrane Fusion ◽  
Strong Support ◽  
Force Production ◽  
Snare Proteins ◽  
Coarse Grained ◽  
Aspect Ratios ◽  
Extended Contact ◽  
Fusion Site ◽  
Simple Body ◽  
Core Components

SNARE proteins are the core components of the cellular machineries that fuse membranes for neurotransmitter or hormone release and other fundamental processes. Fusion is accomplished when SNARE proteins hosted by apposing membranes form SNARE complexes called SNAREpins, but the mechanism of fusion remains unclear. Computational simulations of SNARE-mediated membrane fusion are challenging due to the millisecond timescales of physiological membrane fusion. Here we used ultra-coarse-grained (UCG) simulations to investigate the minimal requirements for a molecular intracellular fusogen, and to elucidate the mechanisms of SNARE-mediated fusion. We find fusion by simple body forces that push vesicles together is highly inefficient. Inter-vesicle fusogens with different aspect ratios can fuse vesicles only if they are rodlike, of sufficient length to clear the fusogens from the fusion site by entropic forces. Simulations with rod-shaped SNAREpin-like fusogens fused 50-nm vesicles on ms timescales, driven by entropic forces along a reproducible fusion pathway. SNARE-SNARE and SNARE-membrane entropic forces cleared the fusion site and pressed the vesicles into an extended contact zone (ECZ), drove stalk nucleation at the high curvature ECZ boundary, and expanded the stalk into a long-lived hemifusion diaphragm in which a simple pore completed fusion. Our results provide strong support for the entropic hypothesis of SNARE-mediated membrane fusion, and implicate the rodlike structure of the SNAREpin complex as a necessity for entropic force production and fusion.

Phylogenetic considerations below the sectional level in Carex

1990 ◽  
Vol 68 (7) ◽  
pp. 1433-1440 ◽  
Author(s):  
William J. Crins
Keyword(s):  
Phylogenetic Relationship ◽  
Chromosome Evolution ◽  
Phylogenetic Reconstruction ◽  
Strong Support ◽  
Character State ◽  
Data Sets ◽  
Compatibility Analysis ◽  
External Data ◽  
Character Compatibility

Few estimates of phylogenetic relationship below the sectional level have been proposed within the genus Carex (Cyperaceae). The reasons for this include (1) poorly circumscribed sections (paraphyletic and polyphyletic), (2) uncertain relationships among sections, and (3) difficulty in objectively assessing character state polarities. The operational difficulties posed by points 2 and 3 can be overcome through the use of character compatibility analysis, if it can be demonstrated that the section under study is monophyletic (point 1). This technique enables the investigator to generate hypotheses of relationship while minimizing the number of prior assumptions. Hypotheses of phylogenetic relationship are presented for the taxa within Carex sections Phyllostachyae, Limosae, and Ceratocystis. The topologies of these unrooted networks are assessed using external data sets (chromosome numbers, etc.) that serve as tests of the hypotheses, and may allow for a posteriori determination of character state polarities. In sections Ceratocystis and Limosae, these analyses provide strong support for the notion that chromosome evolution in Carex proceeds in a linear stepwise fashion. The results for section Phyllostachyae contradict this notion. Synthesis of all available data, coupled with phylogenetic reconstruction, will enable caricologists to provide more convincing arguments about the nature, direction, and factors influencing character state change.

scholarly journals Constructal Optimization of Rectangular Microchannel Heat Sink with Porous Medium for Entropy Generation Minimization

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1528
Author(s):  
Wenlong Li ◽  
Zhihui Xie ◽  
Kun Xi ◽  
Shaojun Xia ◽  
Yanlin Ge
Keyword(s):  
Heat Flux ◽  
Aspect Ratio ◽  
Entropy Generation ◽  
Heat Sink ◽  
Width Ratio ◽  
Microchannel Heat Sink ◽  
Rectangular Microchannel ◽  
Entropy Generation Minimization ◽  
Aspect Ratios ◽  
Length Width

A model of rectangular microchannel heat sink (MCHS) with porous medium (PM) is developed. Aspect ratio of heat sink (HS) cell and length-width ratio of HS are optimized by numerical simulation method for entropy generation minimization (EGM) according to constructal theory. The effects of inlet Reynolds number (Re) of coolant, heat flux on bottom, porosity and volume proportion of PM on dimensionless entropy generation rate (DEGR) are analyzed. From the results, there are optimal aspect ratios to minimize DEGR. Given the initial condition, DEGR is 33.10% lower than its initial value after the aspect ratio is optimized. With the increase of Re, the optimal aspect ratio declines, and the minimum DEGR drops as well. DEGR gets larger and the optimal aspect ratio remains constant with the increasing of heat flux on bottom. For the different volume proportion of PM, the optimal aspect ratios are diverse, but the minimum DEGR almost stays unchanged. The twice minimized DEGR, which results from aspect ratio and length-width ratio optimized simultaneously, is 10.70% lower than the once minimized DEGR. For a rectangular bottom, a lower DEGR can be reached by choosing the proper direction of fluid flow.

Nonlinear Dynamic Analysis of Micro Cantilever Beam Under Electrostatic Loading

2012 ◽  
Vol 28 (1) ◽  
pp. 63-70 ◽  
Author(s):  
C.-C. Liu ◽  
S.-C. Yang ◽  
C.-K. Chen
Keyword(s):  
Cantilever Beam ◽  
Nonlinear Dynamic Analysis ◽  
Nonlinear Behavior ◽  
Computationally Efficient ◽  
Hybrid Scheme ◽  
Electrostatically Actuated ◽  
Aspect Ratios ◽  
Beam System ◽  
Length Width ◽  
Micro Cantilever

ABSTRACTA hybrid differential transformation / finite difference scheme is used to analyze the complex nonlinear behavior of an electrostatically-actuated micro cantilever beam which high aspect ratios (length/width). The validity of the proposed method is confirmed by comparing the numerical results obtained for the tip displacement and pull-in voltage of the cantilever beam with the analytical and experimental results presented in the literature. The hybrid scheme is then applied to analyze both the steady-state and the dynamic deflection behavior of the cantilever beam as a function of the applied voltage. Overall, the results confirm that the hybrid method provides an accurate and computationally-efficient means of analyzing the complex nonlinear behavior of both the current micro cantilever beam system and other micro-scale electrostatically-actuated structures.

Supersonic jet control with shifted tabs

2016 ◽  
Vol 232 (3) ◽  
pp. 433-447 ◽  
Author(s):  
K Maruthupandiyan ◽  
E Rathakrishnan
Keyword(s):  
Pressure Gradient ◽  
Nozzle Exit ◽  
Supersonic Jet ◽  
Pressure Oscillation ◽  
Adverse Pressure Gradient ◽  
Mixing Enhancement ◽  
Aspect Ratios ◽  
Core Length ◽  
Expansion Level ◽  
Length Width

Mixing characteristics of a Mach 2 jet controlled by shifted tabs have been studied at different levels of expansion at the nozzle exit. Two identical rectangular flat tabs of aspect ratios (length/width) 3, 4, 5 and 6, offering 2.5% blockage each, located diametrically opposite, found that the mixing promotion caused by the shifted tab increases with increase of adverse pressure gradient (that is, below NPR 5). On the contrary, the mixing enhancement caused by tab placed at the nozzle exit decreases with increase of adverse pressure gradient. At higher NPRs from 5 to 8 for shifted tab configuration, the amplitude of centerline pitot pressure oscillation is considerably smaller than the uncontrolled jet. At lower NPRs, corresponding to expansion level pe /pa, from 0.383 to 0.511, shifted tab is found to be a better mixing promoter than the tab at the nozzle exit. But for expansion levels from 0.511 to 1.022, mixing promoted by tab at nozzle exit is better than the shifted tabs. Shifted tab at 0.5D results in about 55% reduction in core length, at NPR 3, and the corresponding core length reduction by tabs at 0.25D, 0.5D, and 0D is 25.93%, 22.2%, and 14.81%, respectively.

Autonomous propulsion of nanorods trapped in an acoustic field

2017 ◽  
Vol 825 ◽  
pp. 29-48 ◽  
Author(s):  
Jesse F. Collis ◽  
Debadi Chakraborty ◽  
John E. Sader
Keyword(s):  
Density Distribution ◽  
Stokes Equations ◽  
A Priori ◽  
Model Systems ◽  
Small Scale ◽  
Mathematical Framework ◽  
Dimensionless Frequency ◽  
Physical Mechanisms ◽  
Aspect Ratios ◽  
Length Width

Acoustic fields in a liquid medium can trap and suspend small particles at their pressure nodes. Recent measurements demonstrate that nanorods immersed in these fields generate autonomous propulsion, with their direction and speed controlled by both the particle’s shape and density distribution. Specifically, slender nanorods with an asymmetric density distribution about their geometric centre are observed to move steadily with their low density end leading the motion; particle geometry exerts an equally significant and potentially opposing effect. In this article, we investigate the physical mechanisms underlying this combined density/shape induced phenomenon by developing a simple yet rigorous mathematical framework for axisymmetric particles. This only requires solution of the (linear) unsteady Stokes equations, which can be performed numerically or analytically. The theory holds for all particle shapes, particle aspect ratios (length/width) and acoustic frequencies. It is applied to slender dumbbell-shaped particles and asymmetric nanorods – these provide model systems to investigate the competing effects governing propulsion. This shows that geometric and density asymmetries in the particle generate axial jets that can produce motion in either direction, depending on the relative strengths of these asymmetries and the acoustic Reynolds number (dimensionless frequency). Strikingly, the propulsion direction is found to reverse with increasing frequency, an effect that is yet to be reported experimentally. The general theory and mechanism described here enable the a priori design and fabrication of nano-motors in fluid for transport of small-scale payloads and robotic applications.

Fabrication and Strength-Based Design of a Meso Forceps

2009 ◽  
Author(s):  
M. E. Aguirre ◽  
G. Hayes ◽  
C. Yuangyai ◽  
M. Frecker ◽  
J. Adair ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Research Effort ◽  
Optimization Method ◽  
Surgical Instruments ◽  
Full Density ◽  
Stress Constraint ◽  
Material Strength ◽  
Aspect Ratios ◽  
Length Width ◽  
Dimensional Parameters

A novel fabrication process and design optimization method for a mesoscale forceps is presented. This work is part of a larger research effort to design and fabricate nanoparticulate enabled surgical instruments using an iterative fabrication-design technique. The current paper focuses on the fabrication of thick (∼hundreds of microns) two dimensional parts with large aspect ratios (length/width > 20). The paper also describes an optimization method that accounts for manufacturing requirements and material strength. The process begins with the fabrication of an array of molds on refractory substrates using a modified UV lithography technique. In parallel, engineered ceramic nanocolloidal slurries are prepared for gel-casting into the molds. Mold infiltration takes place via a squeegee technique adapted from screen printing with excess slurry removed using an ethanol bath. Finally, the photoresist molds are removed via pyrolysis, and ceramic parts sintered to full density. Employing this manufacturing technique for the compliant micro forceps design is advantageous because a large number of parts can be produced with large aspect ratios, sharp edges (∼ 1 μm), and a resolution of 2 μm. An optimization algorithm, using ANSYS optimization module, is formulated to determine the effect of dimensional parameters and material strength on the optimal design and predicted performance of the compliant meso forceps. Three ultimate strength values are separately implemented as a stress constraint in our optimization problem. Results conclude that our manufacturing process is capable of producing meso scale forceps considering the anticipated ultimate strength at this scale.

scholarly journals Learning the Special Note: Evidence for a critical period for absolute pitch acquisition

2021 ◽  
Author(s):  
Frank A Russo ◽  
Deborah L Windell ◽  
Lola L Cuddy
Keyword(s):  
Critical Period ◽  
Strong Support ◽  
Absolute Pitch ◽  
Identification Accuracy ◽  
Single Tone ◽  
The Third

Children (3–6 years old) and adults were trained for 6 weeks to identify a single tone, C5. Test sessions, held at the end of each week, had participants identify C5 within a set of seven alternative tones. By the third week of training, identification accuracy of children 5–6 years old surpassed the accuracies of children 3–4 years old and adults. Combined with an analysis of perceptual strategies, the data provide strong support for a critical period for absolute pitch acquisition.

scholarly journals VARIASI KARAKTER MORFOLOGIS LIMA JENIS SAGU (Metroxylon sp) DI PULAU SAPARUA

2015 ◽  
Vol 1 (2) ◽  
pp. 105-111
Author(s):  
Lepinus Sahetapy ◽  
Ritha L Karuwal
Keyword(s):  
Food Industry ◽  
Morphological Character ◽  
Morphological Characters ◽  
Raw Material ◽  
Measuring Instrument ◽  
Quantitative Parameter ◽  
Leaf Character ◽  
Length Width ◽  
Food Commodities ◽  
Generative Organs

Background: Sago (Metroxylon sp) is one of food commodities that contains many carbohydrates, so it serves as a staple food for some regions in Indonesia such as Maluku, Papua and Sulawesi. Sago can also be used as raw material for food industry such as bagea, sago pearl, pastry, wet cake, noodle, biscuit, cracker and vermicelli. Various uses of sago cause attention in terms of development and conservation. Saparua Island is one of the areas in the Maluku archipelago with sago potential that is wide enough. There are 5 types of sago in the area such as sago tuni, sagu molat, sago eataru, sagu ihur, and sago thorn rattan.Methods: This research took place in February-March 2014 by conducting exploration on location and samples selected by proposive sampling. For each quantitative parameter such as height, length, width, using a measuring instrument of ruler, roll meter while qualitative parameters such as shape, color can be observed visually.Results: Exploration was conducted on February-March 2014 with morphological character parameters on vegetative and generative organs of 70 characters. The results of the study showed a varied morphological appearance in each variety. Visually, variations of morphological characters in the vegetative organ seen in the trunk character are height, surface, circumference, color. Leaf character has variation in leaf sponge, leaf bone flexibility, midst of base of midrib, midrib, midrib, midrib, midlet, child length, upper surface. Morphological characters in generative organs appear to vary in flower, ie, the length and width of the stem, the diameter of the flower. Variations in fruits such as shape, amount, and color while on the seeds are the color and weight.Conclusion: There are variations of morphological characters in the five varieties of sago on Saparua Island in shape, size, and color, appearance of each organ either on stems, leaves, flowers, fruits and seeds.

Sign in / Sign up

Export Citation Format

Share Document