scholarly journals A Statistical Growth Property of Plant Root Architectures

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Sam Sultan ◽  
Joseph Snider ◽  
Adam Conn ◽  
Mao Li ◽  
Christopher N. Topp ◽  
...  
Keyword(s):  
Plant Root ◽  
Transport Systems ◽  
Spatial Density ◽  
Growth Strategies ◽  
Growth Property ◽  
3 Dimensional ◽  
Visual Diversity ◽  
Basic Plant ◽  
Gaussian Density ◽  
Standard Deviations

Numerous types of biological branching networks, with varying shapes and sizes, are used to acquire and distribute resources. Here, we show that plant root and shoot architectures share a fundamental design property. We studied the spatial density function of plant architectures, which specifies the probability of finding a branch at each location in the 3-dimensional volume occupied by the plant. We analyzed 1645 root architectures from four species and discovered that the spatial density functions of all architectures are population-similar. This means that despite their apparent visual diversity, all of the roots studied share the same basic shape, aside from stretching and compression along orthogonal directions. Moreover, the spatial density of all architectures can be described as variations on a single underlying function: a Gaussian density truncated at a boundary of roughly three standard deviations. Thus, the root density of any architecture requires only four parameters to specify: the total mass of the architecture and the standard deviations of the Gaussian in the three x,y,z growth directions. Plant shoot architectures also follow this design form, suggesting that two basic plant transport systems may use similar growth strategies.

scholarly journals A design principle of root length distribution of plants

2019 ◽  
Vol 16 (161) ◽  
pp. 20190556
Author(s):  
Yeonsu Jung ◽  
Keunhwan Park ◽  
Kaare H. Jensen ◽  
Wonjung Kim ◽  
Ho-Young Kim
Keyword(s):  
Water Uptake ◽  
Root Length ◽  
Fluid Transport ◽  
Root Length Density ◽  
Global Climate ◽  
Plant Root ◽  
Length Distribution ◽  
Biological Data ◽  
Transport Systems ◽  
Network Systems

Shaping a plant root into an ideal structure for water capture is increasingly important for sustainable agriculture in the era of global climate change. Although the current genetic engineering of crops favours deep-reaching roots, here we show that nature has apparently adopted a different strategy of shaping roots. We construct a mathematical model for optimal root length distribution by considering that plants seek maximal water uptake at the metabolic expenses of root growth. Our theory finds a logarithmic decrease of root length density with depth to be most beneficial for efficient water uptake, which is supported by biological data as well as our experiments using root-mimicking network systems. Our study provides a tool to gauge the relative performance of root networks in transgenic plants engineered to endure a water deficit. Moreover, we lay a fundamental framework for mechanical understanding and design of water-absorptive growing networks, such as medical and industrial fluid transport systems and soft robots, which grow in porous media including soils and biotissues.

scholarly journals A Systematic Analysis of Errors in Target Localization and Treatment Delivery for Stereotactic Radiosurgery Using 2D/3D Image Registration

2016 ◽  
Vol 16 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Hao Xu ◽  
Stephen Brown ◽  
Indrin J. Chetty ◽  
Ning Wen
Keyword(s):  
Computed Tomography ◽  
Image Registration ◽  
Stereotactic Radiosurgery ◽  
Systematic Errors ◽  
Target Localization ◽  
Two Dimensional ◽  
3 Dimensional ◽  
Dimensional Image ◽  
Significant Difference ◽  
Standard Deviations

Purpose: To determine the localization uncertainties associated with 2-dimensional/3-dimensional image registration in comparison to 3-dimensional/3-dimensional image registration in 6 dimensions on a Varian Edge Linac under various imaging conditions. Methods: The systematic errors in 6 dimensions were assessed by comparing automatic 2-dimensional/3-dimensional (kV/MV vs computed tomography) with 3-dimensional/3-dimensional (cone beam computed tomography vs computed tomography) image registrations under various conditions encountered in clinical applications. The 2-dimensional/3-dimensional image registration uncertainties for 88 patients with different treatment sites including intracranial and extracranial were evaluated by statistically analyzing 2-dimensional/3-dimensional pretreatment verification shifts of 192 fractions in stereotactic radiosurgery and stereotactic body radiotherapy. Results: The systematic errors of 2-dimensional/3-dimensional image registration using kV–kV, MV–kV, and MV–MV image pairs were within 0.3 mm and 0.3° for the translational and rotational directions within a 95% confidence interval. No significant difference ( P > .05) in target localization was observed with various computed tomography slice thicknesses (0.8, 1, 2, and 3 mm). Two-dimensional/3-dimensional registration had the best accuracy when pattern intensity and content filter were used. For intracranial sites, means ± standard deviations of translational errors were −0.20 ± 0.70 mm, 0.04 ± 0.50 mm, and 0.10 ± 0.40 mm for the longitudinal, lateral, and vertical directions, respectively. For extracranial sites, means ± standard deviations of translational errors were −0.04 ± 1.00 mm, 0.2 ± 1.0 mm, and 0.1 ± 1.0 mm for the longitudinal, lateral, and vertical directions, respectively. Two-dimensional/3-dimensional image registration for intracranial and extracranial sites had comparable systematic errors that were approximately 0.2 mm in the translational direction and 0.08° in the rotational direction. Conclusion: The standard 2-dimensional/3-dimensional image registration tool available on the Varian Edge radiosurgery device, a state-of-the-art system, is helpful for robust and accurate target positioning for image-guided stereotactic radiosurgery.

scholarly journals MEKANISME FISIOLOGIS TUMBUHAN HIPERAKUMULATOR LOGAM BERAT = Heavy Metal Hyperaccumulator Plant Physiology Mechanism

2016 ◽  
Vol 14 (2) ◽  
pp. 75 ◽  
Author(s):  
Nuril Hidayanti
Keyword(s):  
Plant Species ◽  
Contaminated Soils ◽  
Plant Root ◽  
Toxic Metal ◽  
Transport Systems ◽  
Metal Hyperaccumulation ◽  
Long Distance ◽  
Hyperaccumulator Plants ◽  
Plant Root System ◽  
Distance Transport

One approach to remediate toxic metal pollutants is phytoextraction using hyperaccumulator plants. These plant species are able to accumulate high concentrations of metal ions without suffering fromyield reduction as a result of metal toxicity. Physiological studies showed that metal hyperaccumulation in particular plant species is regulated by multiple pathways and genes controlling metal uptake,accumulation, and tolerance. Currently, research and development on hyperaccumulator plants are progressing in at least seven focus areas: (1) Improving plant root system for higher penetration capacity and more efficient pollutant extraction from heterogeneous contaminated soils, (2) Altering plant’s rhizosphere for secreting various enzymes to enhance extraction, (3) Improving short distance transport systems for nutrients and toxic elements in roots (4) Enhancing mobility of metalsfrom roots up to shoots. (5) Improving long-distance transport of metals, (6) Maximizing capacity of physical sinks such as subcellular vacuoles and epidermal cells and (7) hypertolerance mechanismsto resist the cytotoxic effects of the accumulated metals. Current trends in phytoremediation research are focus at genetic and molecular level. Research objectives in this area include: understanding bio-pathways involved in contaminant degradation and sequestration, identifying specific genes involved in phytoremediation processes, investigating cell signaling pathways that affect genetic expression of plant enzymes, analyzing and identifying root exudates components and chemical fingerprinting to assess phytoremediation effects at specific sites. Keywords: hyperaccumulator, phytoextraction, phytoremediation, heavy metalsAbstrakSalah satu pendekatan untuk memulihkan polutan logam beracun adalah phytoextraction menggunakan tanaman hiperakumulator . Jenis tanaman ini mampu mengakumulasi konsentrasitinggi ion logam tanpa mengalami penurunan hasil akibat keracunan logam. Studi fisiologis menunjukkan bahwa hyperaccumulator logam dalam spesies tanaman tertentu diatur oleh beberapajalur dan gen mengendalikan serapan, akumulasi , dan toleransi logam. Saat ini, penelitian dan pengembangan tanaman hiperakumulator mengalami kemajuan dalam setidaknya tujuh bidangfokus: (1) Meningkatkan sistem perakaran tanaman untuk kapasitas penetrasi yang lebih tinggi dan ekstraksi polutan lebih efisien dari tanah yang terkontaminasi, (2) Mengubah rizosfir tanaman untukmengekstrak berbagai enzim guna meningkatkan ekstraksi, (3) Meningkatkan sistem transportasi jarak pendek untuk nutrisi dan unsur-unsur beracun dalam akar, (4) Meningkatkan mobilitas logamdari akar hingga pucuk, (5) Meningkatkan transportasi jarak jauh dari logam, (6) Memaksimalkan kapasitas tenggelam fisik seperti vakuola subselular, sel-sel epidermis, dan (7) Mekanisme hypertolerance untuk melawan efek sitotoksik dari logam akumulasi . Saat ini kecenderungan dalam penelitian fitoremediasi adalah fokus pada tingkat genetik dan molekuler. Tujuan penelitian di bidangini meliputi: pemahaman bio - jalur yang terlibat dalam degradasi kontaminan dan penyerapan , mengidentifikasi gen tertentu yang terlibat dalam proses fitoremediasi , menyelidiki jalur sinyal selyang mempengaruhi ekspresi genetik dari enzim tanaman , menganalisis dan mengidentifikasi eksudat akar komponen dan sidik jari kimia untuk menilai fitoremediasi efek pada situs tertentuKata Kunci: hiperakumulator, phytoextraction, fitoremediasi, logam berat

scholarly journals BIM-Based Educational and Facility Management of Large University Venues

2020 ◽  
Vol 10 (22) ◽  
pp. 7976 ◽  
Author(s):  
Rubén Muñoz Pavón ◽  
Antonio A. Arcos Alvarez ◽  
Marcos G. Alberti
Keyword(s):  
Management System ◽  
Building Information Modeling ◽  
Application Programming Interface ◽  
Facility Management ◽  
Information Modeling ◽  
Transport Systems ◽  
3 Dimensional ◽  
Building Information ◽  
Real Time Information ◽  
Future Management

The aim of this paper was to provide a Building Information Modeling (BIM)-based management system for the Civil Engineering School (ETSICCP) at the Universidad Politécnica de Madrid with a long-term development perspective. A Building Information Modeling (BIM) management system for complex infrastructure facilities demands a detailed 3-Dimensional model according to future management requirements. In this study, the infrastructure of the ETSICCP was modeled on various phases and synchronized with not only external educational information but also with facility management (FM) parameters. The methodology followed in this study ranges from the blank paper to a BIM-based detailed FM system oriented to educational scheduling throughout the infrastructure providing real time information synchronized with spreadsheets and a 3-D model. The result of this paper provides multiples future management lines, like COVID-19 BIM-management or synchronization with local public transports’ applications (mainly metro and bus transport systems), through a public accessible Application Programming Interface (API). The significance of this research relies on the generation of an information and management system, based on a BIM model of a university campus. This project was designed for all the agents involved in its operation, students, lecturers, and managers. All these agents have a level of access appropriate to their needs and functions within the institution.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

Reconstruction of Objects from their Projections Using Orthogonal Functions

1973 ◽  
Vol 31 ◽  
pp. 268-269
Author(s):  
Elrnar Zeitler
Keyword(s):  
Unit Area ◽  
Three Dimensional ◽  
One Dimension ◽  
Spatial Density ◽  
Dimensional Representation ◽  
Orthogonal Functions ◽  
Object A ◽  
Plane Normal ◽  
Dimensional Object ◽  
Spatial Density Distribution

Considering any finite three-dimensional object, a “projection” is here defined as a two-dimensional representation of the object's mass per unit area on a plane normal to a given projection axis, here taken as they-axis. Since the object can be seen as being built from parallel, thin slices, the relation between object structure and its projection can be reduced by one dimension. It is assumed that an electron microscope equipped with a tilting stage records the projectionWhere the object has a spatial density distribution p(r,ϕ) within a limiting radius taken to be unity, and the stage is tilted by an angle 9 with respect to the x-axis of the recording plane.

Deviations from Ideal Decagonal Symmetry in Electron Diffraction Patterns of the “Decagonal” Phase in the Al-Co-Cu Alloy System

1991 ◽  
Vol 49 ◽  
pp. 914-915
Author(s):  
Atul S. Ramani ◽  
Earle R. Ryba ◽  
Paul R. Howell
Keyword(s):  
Electron Microscope ◽  
Alloy System ◽  
Nominal Composition ◽  
Dimensional Lattice ◽  
3 Dimensional ◽  
Decagonal Phase ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Lattice Periodicity ◽  
Diffraction Patterns

The “decagonal” phase in the Al-Co-Cu system of nominal composition Al65CO15Cu20 first discovered by He et al. is especially suitable as a topic of investigation since it has been claimed that it is thermodynamically stable and is reported to be periodic in the dimension perpendicular to the plane of quasiperiodic 10-fold symmetry. It can thus be expected that it is an important link between fully periodic and fully quasiperiodic phases. In the present paper, we report important findings of our transmission electron microscope (TEM) study that concern deviations from ideal decagonal symmetry of selected area diffraction patterns (SADPs) obtained from several “decagonal” phase crystals and also observation of a lattice of main reflections on the 10-fold and 2-fold SADPs that implies complete 3-dimensional lattice periodicity and the fundamentally incommensurate nature of the “decagonal” phase. We also present diffraction evidence for a new transition phase that can be classified as being one-dimensionally quasiperiodic if the lattice of main reflections is ignored.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Structure and Interaction of Protamine by Dark Field Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 160-161
Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer
Keyword(s):  
Electron Microscopy ◽  
Dark Field ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
3 Dimensional ◽  
Field Electron ◽  
Proposed Model ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Positively Charged

It has been shown for some time that it is possible to obtain images of small unstained proteins, with a resolution of approximately 5Å using dark field electron microscopy (1,2). Applying this technique, we have observed a uniformity in size and shape of the 2-dimensional images of pure specimens of fish protamines (salmon, herring (clupeine, Y-l) and rainbow trout (Salmo irideus)). On the basis of these images, a model for the 3-dimensional structure of the fish protamines has been proposed (2).The known amino acid sequences of fish protamines show stretches of positively charged arginines, separated by regions of neutral amino acids (3). The proposed model for protamine structure (2) consists of an irregular, right-handed helix with the segments of adjacent arginines forming the loops of the coil.

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