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inspector

PURPOSE

inspector allows one to inspect the pairwise maps produced by the register program, and, if they are not correct, to add correspondence points that will help register them in a second pass.

transform_images

COMMAND LINE OPTIONS

-crop minX maxX minY maxY

-image_list images.lst

-input directory/

-mask directory/

-output directory/

-output_mask directory/

-resize new_width new_height

-rotate float_ccw_rotation_in_degrees

-scale float_factor

-shift float_x float_y

-size new_width new_height-stretch float_factor_x float_factor_y

 

 

 

register

PURPOSE

register takes pairs of images, and finds a non-linear mapping that registers the first image of the pair (the source image) to the second (the target image).  If the images differ substantially in content or have obvious distortions or artifacts, it is recommended that the output maps from register are checked with inspector.  If errors are found, one can use inspector to add correspondence points and rerun register with the -cpts option.

 

TYPICAL USAGE

register -pairs pairs.lst  \
-images images/ \
-masks masks/ \
-output_level 6 \
-depth 6 \
-quality 0.5 \
-output maps/

COMMAND LINE OPTIONS

-affine

When correspondence points are provided, use the best affine transformation derived from these correspondence points as the initial map.

-all_maps

If specified, this option causes all intermediate maps to be written out, not just the one at final resolution.  (mostly for debugging)

-constraining float_weight

This options controls how much deviations from a constraining map are weighted when searching for a registration.  If no constraining_map option is given, this option has no effect.

-constraining_confidence_threshold float_threshold

If this option is given, then only consider map elements in the constraining map that have a confidence value greater than the given threshold.  If no constraining_map option is given, this option has no effect.

-constraining_map directory/

If specified, use a constraining map to restrict the search for a registration.  A constraining map is used as a hint for where the correct solution should lie.    When evaluating a map the search algorithm will check if the distance between points projected using the map being evaluated and points projected using the constraining map.  If their distance is greater than the constraining_threshold, then a penalty term is added onto the evaluation.

-constraining_threshold float_distance_in_pixels

The constraining threshold represents the geometrical uncertainty (expressed in pixel distances in the original images) of the constraining map.  Larger values mean the constraining map is more uncertain, and a 0 value means that any variation from the constraining map will be penalized (not terribly useful).   The default value is 0, so one should include this option if one is using constraining maps.

-correlation_half_width int_distance_in_pixels

This sets the half width of the kernel used for computing localized image correlation.   The localized image correlation is only used for output (in determining the confidences of the map elements), and is not used in actually performing the registration.  Defaults to 31.

-correspondence float_weight

This option controls how much deviations from the correspondence points are weighted when searching for a registration.  If no correspondence points are available for the image pair, this option has no effect.  The default value is 1.

-correspondence_threshold float_distance_in_pixels

If this option is given, then do not penalize maps that project the correspondence points to within this distance of each other.  This is useful when there is some uncertainty in marking up the correspondence points, or even just to compensate for slight mouse movement that happened when the used was clicking the mouse to mark the correspondence points.  The default value is 0.

-cpts directory/

use the correspondence points found in the given directory.  The name of the correspondence points file is generated by appending ".cpts" to the image pair name.  The correspondence points file is usually automatically generated by the inspect program, but can also be manually generated and edited.  The format of the correspondence points file is a list of correspondence point pairs:

 img_x img_y ref_x ref_y

 where img_x iand img_y are the x and y coordinates of a point in the image, and ref_x and ref_y are the coordinates of the corresponding point in the reference image.

-depth int_depth_exponent

sets the ratio between the map resolution and image resolution as the program registers the images.  For example, if this is set to 6, then when computing the 16x16 map, the images at resolution 1024x1024 will be used when computing the correlation (since 16 * 2^6 = 1024).  This same ratio will be used as the map resolution is progressively increased, until the native image resolution is reached. This parameter defaults to 6.

-distortion float_weight

This option controls how much map distortion (i.e., the deviation of each element from a perfect square) is weighted when searching for a registration.  This parameter defaults to 1.  Set it lower to tolerate more distortion, and set it higher to tolerate less distortion.

-images directory/

specifies the directory where the images will be read from.

-initial_map directory/

specifies the directory where the initial maps will be read from.

 -logs directory/

specifies the directory where log files are written to; if this option is omitted, no log files will be written.

-masks directory/

specifies the directory where the masks will be read from.

-min_overlap float_percentage

specifies the minimum percentage overlap between the images.  This avoids the problem of finding a "perfect registration" by overlapping a single corner pixel in one image with another corner pixel in the other image that happens to have the same value.  The default value for this parameter is 20.

-min_res int_resolution_in_pixels

specifies that images should not be reduced to a size smaller than the given number pixels in either x or y.   This is to prevent excessive reduction that would blur out details important for registration.  The default value is 1, which allows for arbitrary reduction.

-output directory/

specifies the output directory where maps are to be written.

-output_correlation directory/

specifies the directory where correlation images should be written to.  The correlation image is white where the correlations are highest and black where they are lowest.  The correlation image is congruent with the first image of the image pair.  If this option is omitted, no correlation images will be output.

-output_level int_level

specifies the level of resolution of the output maps.  This is expressed as the base-2 logarithm of the pixel distance between map points (in both x and y diimensions).  For example, a value of 6 would indicate that the maps should have a grid point every 64 pixels in x and y.  Typical values for this range from 6 to 10.  The default value is 6.

-output_mask directory/

specifies where optional output masks are located.  Note that the output mask is an input to the register program.  If this option is present, the output mask will determine which map elements get filled in by the register program; only those map elements necessary to cover the unmasked pixels will get filled in.  The masks in the output_mask directory should have the same width and height as the first component of the image pair.

-output_pairs outpairs.lst

If this option is present, then the pairs that were actually updated will be written to the specified list file.  Use this in conjunction with the -update option.

-output_pairwise_mask directory/

This option is very similar in function to the -output_mask option.  The difference is that with -output_pairwise_mask , the image pair name is used to construct the name of the output mask file that will be read in, whereas with -output_mask only the name of the first image of the pair is used to construct the name of the output mask file.

-output_sorted_pairs outpairs.lst

If this option is present, then the pairs that were actuall updated will be sorted according to registration score (lowest first) and then written to the specified list.  The registration score is better for those pairs for which the program is more confident of a good match.  Thus, this enables the user to go through suspect pairs first until reaching pairs whose registration is likely correct.  Both this option and the -output_pairs option may be used together.

-output_warped directory/

If this option is present, then the second member of the image pair (the reference image) will be warped to match the first image, and the resultant image will be written to the specified directory as a .pgm file.   The output resolution will match that of the first image.  Note that the apply_map program offers this capability as well, but with many more options.

-pairs pairs.lst

specifies the list of image pairs that are to be registered.  This list consists of lines of the following form:

image0_name [ image0_minX image0_maxX image0_minY image0_maxY ] image1_name [ image1_minX image1_maxX image1_minY image1_maxY ] pair_name

If the optional minX, maxX, minY, and maxY components are specified, they designate a subregion of the image to register.  This is useful for instance when one is matching up the right side of one image with the left side of an overlapping image.  To use the entire image, the minX, maxX, minY, and maxY compoments may be omitted, or they may all be set to -1.  The pair_name is the name given to the image pair.  Often, it will just consist of the individual image names concatenated together, perhaps with an intervening underscore or hyphen.  Occasionally,as when many images are being registered to a single reference image, it would make sense for the pair name to just be the same as the image0_name.

-partial

If this option is specirfied, then ignore pairs for which some of the necessary files (image files or mask files) are missing.  By default, an error will be generated if files are found to be missing, and program execution will terminate.

-quadratic

When correspondence points are provided, use the best quadratic transformation derived from these correspondence points as the initial map.

-quality float_quality

The option specifies how much search is to be performed to look for the best registration.  The number of iterations (and hence run time) correlates roughly linearly with the quality parameter.  Typical values are in the 0.1-10.0 range.  A too small value for this parameter will generate a solution quickly, but its quality will be poor.  On the other hand, choosing too large a value will take a large amount of processing time, with no guarantee of a correct solution.   If the images differ greatly, or are noisy, or contain repeated subimages, or have incorrect initial maps, then the program may generate incorrect results even with a high quality parameter.  The default value is 1.0.

-rigid

When correspondence points are provided, use the best rigid transformation derived from these correspondence points as the initial map.

-start_level int_level

Specifies the starting level of resolution for map generation.  By default, the program will determine this from the resolution of the images to be registered.  However, if there is a lack of low-frequency content in the images, it is possible that starting at too high a level (= low image resolution) will cause the images to be excessively downsized and not contain registerable content.  This option can be used to force the program to start at a specific map level.  For instance, if this is set to 10, then the first maps to be computed will have each map element corresponding to a 1024x1024 pixel subregion in the first image.  The image resolution level where correlation is performed will be -depth (q.v.) levels below this, so if the depth is 6, then the images will be downsampled to level 4, i.e., by a factor of 16 from the originals.

-strict_masking

If this option is specified, then map elements will only be computed for image regions where every pixel is unmasked.  Normally, map elements will be computed for image regions where any pixel is unmasked.

-summary summary_file.out

If this option is given, then write out a summary of each pair's registration scores to the specified file.

-tif

If this option is specified along with the -output_warped option, then warped images will be written out as .tif files; otherwise they will be written as .pgm files.

-translation

When correspondence points are provided, use the best translation transformation (no rotation or scaling) derived from these correspondence points as the initial map.

-trim_map_source_threshold float_percentage

If this option is given, then remove map elements where the percentage of valid source (a.k.a. image0) pixels underneath the map element  is less than the specified percentage.  This can be used to remove map elements around the periphery of an image that have a minimal number of pixels inside them, and thus may not be the most reliably positioned.  This option is only applied after map computations are complete, in contrast to the -strict_masking option which is applied while map computations are being done.

-trim_map_target_threshold float_percentage

If this option is given, then remove map elements where the percentage of valid target (a.k.a image1 or reference) pixels underneath the map element is less than the specified percentage.  This can be used to remove map elements around the periphery of an image that have a minimal number of pixels inside them, and thus may not be the most reliably positioned.

-update

If this option is specified, then only perform the registration for image pairs where the output map is non-existent or older than the input files (images, masks, correspondence points, etc.).  This option is especially useful when correspondence points are being added or modified to correct poor registrations.

-vis

This option causes the program, when used in an X windows environment, to graphically display the map refinement as the algorithm proceeds.  This has a significant impact on performance, so is probably best used for debugging.

 

 

reduce_mask

PURPOSE

reduce_mask scales down an image mask by a integral factor.  A pixel will be valid (i.e., unmasked) in the output mask if and only if all pixels in the correponding region of the input mask were valid.

TYPICAL USAGE

reduce_mask -input in.pbm -factor 2 -output out.pbm

COMMAND LINE OPTIONS

-factor int_reduction_factor

specifies the scaling factor by which the mask will be reduced.  This must be an integer.

-input input.pbm

specifies the input mask to be read in.

-output output.pbm

specifies the output mask that will be written.

 

 

Research Highlights

 

Direct coupling of oligomerization and oligomerization-driven endocytosis of the dopamine transporter to its conformational mechanics and activity

The Bahar (TR&D1) and Sorkin (DBP3) labs published an article in the Journal of Biological Chemistry, selected as one of JBC's "Editors' Picks. Our results demonstrate a direct coupling between conformational dynamics of DAT, functional activity of the transporter and its oligomerization leading to endocytosis. The high specificity of such coupling for DAT makes the TM4-9 hub a new target for pharmacological modulation of DAT activity and subcellular localization. (Read more)

 

 

Differences in the intrinsic spatial dynamics of the chromatin contribute to cell differentiation

Comparison with RNA-seq expression data reveals a strong overlap between highly expressed genes and those distinguished by high mobilities in the present study, in support of the role of the intrinsic spatial dynamics of chromatin as a determinant of cell differentiation. (Read more)

 

 

Nanoscale co-organization and coactivation of AMPAR, NMDAR, and mGluR at excitatory synapses

Work by TR&D2 Investigators and collaborators provide insights into the nanometer scale organization of postsynaptic glutamate receptors using a combination of dual-color superresolution imaging, electrophysiology, and computational modeling. (Read more)

 

 

Parallel Tempering with Lasso for model reduction in systems biology

TR&D3 Investigators and collaborators develop PTLasso, a Bayesian model reduction approach that combines Parallel Tempering with Lasso regularization, to automatically extract minimal subsets of detailed models that are sufficient to explain experimental data. On both synthetic and real biological data, PTLasso is an effective method to isolate distinct parts of a larger signaling model that are sufficient for specific data. (Read more)

 

Image-derived models of cell organization changes during differentiation and drug treatments

Our work on modeling PC12 cells undergoing differentiation into neuron-like morphologies (under C&SP11, completed) has been published in Molecular Biology of the Cell. We have also made the large dataset of 3D images collected in that study available through Dryad. (Read more)

 

Monoamine transporters: structure, intrinsic dynamics and allosteric regulation

T&RD1 investigators Mary Cheng and Ivet Bahar published an invited review article in Nature Structural & Molecular Biology, addressing recent progress in the elucidation of the structural dynamics of MATs and their conformational landscape and transitions, as well as allosteric regulation mechanisms. (Read more)

Trimerization of dopamine transporter triggered by AIM-100 binding

The Bahar (TR&D1) and Sorkin (DBP3) labs explored the trimerization of dopamine transporter (DAT) triggered by a furopyrimidine, AIM-100, using a combination of computational and biochemical methods, and single-molecule live-cell imaging assays. (Read more)

Pre-post synaptic alignment through neuroligin-1 tunes synaptic transmission efficiency

TR&D2 investigators and collaborators describe organizing role of neuroligin-1 to align post-synaptic AMPA Receptors with pre-synaptic release sites into trans-synaptic “nano-columns” to enhance signaling.(Read more)

Inferring the Assembly Network of Influenza Virus

In an article in PLoS Computational Biology, MMBioS TR&D4 members Xiongto Ruan and Bob Murphy collaborated with Seema Lakdawala to address this question of the assembly network of the Influenza virus.(Read more)

PINK1 Interacts with VCP/p97 and Activates PKA to Promote NSFL1C/p47 Phosphorylation and Dendritic Arborization in Neurons

Our findings highlight an important mechanism by which proteins genetically implicated in Parkinson’s disease (PD; PINK1) and frontotemporal dementia (FTD; VCP) interact to support the health and maintenance of neuronal arbors.(Read more)

Improved methods for modeling cell shape

In a recent paper in Bioinformatics, Xiongtao Ruan and Bob Murphy of TR&D4 addressed the question of how best to model cell and nuclear shape.(Read more)

New tool to predict pathogenicity of missense variants based on structural dynamics: RHAPSODY

We demonstrated that the analysis of a protein’s intrinsic dynamics can be successfully used to improve the prediction of the effect of point mutations on a protein functionality. This method employs ANM/GNM tools (Read more)

New method for investigating chromatin structural dynamics.

By adapting the Gaussian Network Model (GNM) protein-modeling framework, we were able to model chromatin dynamics using Hi-C data, which led to the identification of novel cross-correlated distal domains (CCDDs) that were found to also be associated with increased gene co-expression.  (Read more)

 

Structural elements coupling anion conductance and substrate transport identified

We identified an intermediate anion channeling state (iChS) during the global transition from the outward facing (OF) to inward facing state (IFS). Our prediction was tested and validated by experimental study conducted in the Amara lab (NIMH). Critical residues and interactions were analyzed by SCAM, electrophysiology and substrate uptake experiments (Read more)

Integrating MMBioS technologies for multiscale discovery

TR&D teams driven by individual DBPs are naturally joining forces, integrating their tools to respond to the needs of the DBP, and creating integrative frameworks for combining structural and kinetic data and computing technologies at multiple scales.  (Read more)

 

Large scale visualization of rule-based models.

Signaling in living cells is mediated through a complex network of chemical interactions. Current predictive models of signal pathways have hundreds of reaction rules that specify chemical interactions, and a comprehensive model of a stem cell or cancer cell would be expected to have many more. Visualizations of rules and their interactions are needed to navigate, organize, communicate and analyze large signaling models.  (Read more)

Integration of MCellR into MCell/CellBlender

Using spatial biochemical models of SynGAP/PSD95, MMBioS investigators were able to merge the MCellR code-base with the MCell code-base and validate its utility and correctness of this sophisticated technology now easily accessible through the MCell/CellBlender GUI.  (Read more)

 

csp29

Causal relationships of spatial distributions of T cell signaling proteins

The idea is to identify a relationship in which a change in the concentration of one protein in one cell region consistently is associated with a change in the concentration of another protein in the same or a different region. We used the data from our Science Signaling paper reported last year to construct a model for T cells undergoing stimulation by both the T cell receptor and the costimulatory receptor. (Read more...)

T-Cell Receptor Signaling

BioNetGen modeling helps reveal immune system response decision

To attack or to let be is an important decision that our immune systems must make to protect our bodies from foreign invaders or protect bodily tissues from an immune attack. Using modeling and experiments, we have painted a sharper picture of how T cells make these critical decisions.  (Read more)

 

 

distancecell

Tools for determining the spatial relationships between different cell components

An important task for understanding how cells are organized is determining which components have spatial patterns that are related to each other.Read more

 

4d rtd

Pipeline for creation of spatiotemporal maps

Using a combination of diffeomorphic methods and improved cell segmentation, we developed a CellOrganizer pipeline for use in DPB4 to construct models of the 4D distributions of actin and 8 of its regulators during the response of T cells to antigen presentation. Read more

 

Multi-scale Hybrid Methodology

The hybrid methodology, coMD, that we have recently developed [1] has been recently extended to construct the energy landscape near the functional states of LeuT (Fig 1) [2]. This is the first energy landscape constructed for this NSS family member. Read more

 


Insights into the cooperative dynamics of AMPAR

Comparative analysis of AMPAR and NMDAR dynamics reveals striking similarities, opening the way to designing new modulators of allosteric interactions. Read more


Improved Sampling of Cell-Scale Models using the WE Strategy

The WE strategy for orchestrating a large set of parallel simulations has now been extended to spatially resolved cell-scale systems. The WESTPA implementation of WE has been used to control MCell simulations, including models built using a BioNetGen-CellOrganizer pipeline for situating complex biochemistry within spatially realistic cell models. Read more

Mouse visual cortex
Anatomy and Function of an Excitatory Network in the Visual Cortex

MMBioS researcher Greg Hood’s collaboration with Wei-Chung Allen Lee of Harvard University and R. Clay Reid of the Allen Institute for Brain Science concerning the reconstruction of an excitatory nerve-cell network in the mouse brain cortex at a subcellular level using the AlignTK software has been published in Nature. Read more

 

Molecular Mechanism of Dopamine Transport by hDAT

Dopamine transporters (DATs) control neurotransmitter dopamine (DA) homeostasis by reuptake of excess DA, assisted by sodium and chloride ions. The recent resolution of DAT structure (dDAT) from Drosophila permits us for the first time to directly view the sequence of events involved in DA reuptake in human DAT (hDAT). Read more

 

 

 

figure good 170Synaptic Facilitation Revealed

An investigation of several mechanisms of short-term facilitation at the frog neuromuscular junction concludes that the presence of a second class of calcium sensor proteins distinct from synaptotagmin can explain known properties of facilitation. Read more

 

langmead2 200Sparse Graphical Models of Protein:Protein Interactions

DgSpi is a new method for learning and using graphical models that explicitly represent the amino acid basis for interaction specificity and extend earlier classification-oriented approaches to predict ΔG of binding. Read more

 

Picture1 180Advancing Parallel Bio-simulations

A new non-Markovian analysis can eliminate bias in estimates of long-timescale behavior, such as the mean first-passage time for the dissociation of methane molecules in explicit solvent. Read more

 

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