The document summarizes key concepts and developments in seismic velocity analysis in transversely isotropic (TI) media over several decades, beginning with Thomsen's (1986) seminal work introducing parameters to characterize TI anisotropy. Subsequent work expanded on non-hyperbolic moveout (Tsvankin and Thomsen 1994), dipping reflectors (Tsvankin 1995), and velocity analysis techniques for TI media (Alkhalifah and Tsvankin 1995). Later contributions improved modeling of non-hyperbolic moveout using rational functions (Douma and Calvert 2006) and the generalized moveout approximation (Fomel and Stovas 2010). The document outlines the theoretical underpinnings of seismic analysis in anisot
Modern oil and gas field management is increasingly reliant on detailed and precise 3D reservoir characterisation, and timely areal monitoring. Borehole seismic techniques bridge the gap between remote surface-seismic observations and downhole reservoir evaluation: Borehole seismic data provide intrinsically higher-resolution, higher-fidelity images than surface-seismic data in the vicinity of the wellbore, and unique access to properties of seismic wavefields to enhance surface-seismic imaging. With the advent of new, operationally-efficient very large wireline receiver arrays; fiber-optic recording using Distributed Acoustic Sensing (DAS); the crosswell seismic reflection technique, and advanced seismic imaging algorithms such as Reverse Time Migration, a new wave of borehole seismic technologies is revolutionizing 3D seismic reservoir characterization and on-demand reservoir surveillance. New borehole seismic technologies are providing deeper insights into static reservoir architecture and properties, and into dynamic reservoir performance for conventional water-flood production, EOR, and CO2 sequestration – in deepwater, unconventional, full-field, and low-footprint environments. This lecture will begin by illustrating the wide range of borehole seismic solutions for reservoir characterization and monitoring, using a diverse set of current- and recent case study examples – through which the audience will gain an understanding of the appropriate use of borehole seismic techniques for field development and management. The lecture will then focus on DAS, explaining how the technique works; its capability to deliver conventional borehole seismic solutions (with key advantages over geophones); then describing DAS’s dramatic impact on field monitoring applications and business-critical decisions. New and enhanced borehole seismic techniques – especially with DAS time-lapse monitoring – are ready to deliver critical reservoir management solutions for your fields.
Nick - Benefits of Using Combined Bathymetry and Side Scan Sonar in Shallow W...Codevintec Italiana srl
Codevintec Days 2018 - Trieste
EDGETECH - Nick - Benefits of Using Combined Bathymetry and Side Scan Sonar in Shallow Water Surveys
Codevintec Days 2018 - Trieste
Relazione di Nick Lawrence - Edgetech
Modern oil and gas field management is increasingly reliant on detailed and precise 3D reservoir characterisation, and timely areal monitoring. Borehole seismic techniques bridge the gap between remote surface-seismic observations and downhole reservoir evaluation: Borehole seismic data provide intrinsically higher-resolution, higher-fidelity images than surface-seismic data in the vicinity of the wellbore, and unique access to properties of seismic wavefields to enhance surface-seismic imaging. With the advent of new, operationally-efficient very large wireline receiver arrays; fiber-optic recording using Distributed Acoustic Sensing (DAS); the crosswell seismic reflection technique, and advanced seismic imaging algorithms such as Reverse Time Migration, a new wave of borehole seismic technologies is revolutionizing 3D seismic reservoir characterization and on-demand reservoir surveillance. New borehole seismic technologies are providing deeper insights into static reservoir architecture and properties, and into dynamic reservoir performance for conventional water-flood production, EOR, and CO2 sequestration – in deepwater, unconventional, full-field, and low-footprint environments. This lecture will begin by illustrating the wide range of borehole seismic solutions for reservoir characterization and monitoring, using a diverse set of current- and recent case study examples – through which the audience will gain an understanding of the appropriate use of borehole seismic techniques for field development and management. The lecture will then focus on DAS, explaining how the technique works; its capability to deliver conventional borehole seismic solutions (with key advantages over geophones); then describing DAS’s dramatic impact on field monitoring applications and business-critical decisions. New and enhanced borehole seismic techniques – especially with DAS time-lapse monitoring – are ready to deliver critical reservoir management solutions for your fields.
Nick - Benefits of Using Combined Bathymetry and Side Scan Sonar in Shallow W...Codevintec Italiana srl
Codevintec Days 2018 - Trieste
EDGETECH - Nick - Benefits of Using Combined Bathymetry and Side Scan Sonar in Shallow Water Surveys
Codevintec Days 2018 - Trieste
Relazione di Nick Lawrence - Edgetech
Slide1:
Seismic Sources
HOW TO GENERATE SEISMIC WAVES?
Exploration seismology – mostly artificial sources
à active technique
Natural sources can also be used (e.g. earthquakes) – usually
for tectonic studies (passive seismic exploration)
!
What is a good source?
- economical, efficient, convenient
- safe and environmentally acceptable
- sufficient energy over the suitable frequency range
- repeatable
Slide 2:
Land seismic sources
Explosives: - usually detonated in boreholes or buried
PROS
- sharp, impulsive, high amplitude (mostly P-wave)
- reasonably cheap
CONS
- The signal is not repeatable
- slow (borehole drilling)
- can be destructive
Presentation on REFRACTION PATHS - Single Horizontal Refractor of Seismic Method in Exploration Geophysics course, Department of Geological Sciences, Jahangirnagar University, Dhaka, Bangladesh. The presentation was conducted through ZOOM app during Corona pandemic in 2021.
SBAS-DInSAR processing on the ESA Geohazards Exploitation PlatformEmmanuel Mathot
In the context of space-borne geodetic techniques, Differential Synthetic Aperture Radar Interferometry (DInSAR) has demonstrated its high performance in measuring surface displacements in different conditions and scenarios, both natural and anthropic. In particular, the advanced DInSAR time series processing method referred to as Small BAseline Subset (SBAS), that allows studying both the spatial and temporal variability of the surface displacements, has proven to be particularly suitable in different contexts, as for natural hazards (volcanoes, earthquakes and landslides) and human-induced deformation (subsidence due to aquifer exploitation, mining operations, and building of large infrastructures). Recently, an efficient implementation of this algorithm (referred to as P-SBAS approach) has been fully integrated within the ESA’s Grid Processing on Demand (G-POD) environment, which is part of the [Geohazards Thematic Exploitation Platform (GEP)](https://geohazards-tep.eo.esa.int/#!) of ESA. The GEP is devoted to the exploitation of EO data resources in the context of the Geohazard Supersites & Natural Laboratories as well as on the CEOS Pilots on Seismic Hazards and Volcanoes. The GEP is sourced with elements, data and processing, including P-SBAS, relevant to the geohazards theme. The integration of the P-SBAS algorithm within GEP resulted in a web-based tool freely available to the scientific community. This tool allows users to process, from their own laptops, the European SAR data archives (ERS, ENVISAT and Sentinel-1) for obtaining surface displacement maps and time series in a completely unsupervised way, without caring about data download and processing facility procurements. The workshop is organized in four parts. First, a short overview on the DInSAR processing methods allowing retrieving mean surface deformation maps and displacement time series will be provided, with a specific focus on the SBAS-DInSAR technique. Secondly, the GEP and G-POD environments will be introduced and the P-SBAS web tool will be presented. The third and the fourth parts are dedicated to the advanced features and to case studies and results achieved via the web tool, respectively.
geophysics seismic waves ,its types, particle motion in S P ans surface waves. Travel time graph . critically refracted , direct and reflected wave arrivals. what is critical distance and crossover distance. relation between critical refracted ,direct and reflected waves.Elastic constants like bulk modulus shear , young's modulus and poisson's ratio. Lame's constant.
Ultrasonic guided wave techniques have great potential for structural health monitoring applications. Appropriate mode and frequency selection is the basis for achieving optimised damage monitoring performance.
In this paper, several important guided wave mode attributes are
introduced in addition to the commonly used phase velocity and group velocity dispersion curves while using the general corrosion problem as an example. We first derive a simple and generic wave excitability function based on the theory of normal mode expansion and the reciprocity theorem. A sensitivity dispersion curve is formulated based on the group velocity dispersion curve. Both excitability and sensitivity dispersion curves are verified with finite element simulations. Finally, a
goodness dispersion curve concept is introduced to evaluate the tradeoffs between multiple mode selection objectives based on the wave velocity, excitability and sensitivity.
Slide1:
Seismic Sources
HOW TO GENERATE SEISMIC WAVES?
Exploration seismology – mostly artificial sources
à active technique
Natural sources can also be used (e.g. earthquakes) – usually
for tectonic studies (passive seismic exploration)
!
What is a good source?
- economical, efficient, convenient
- safe and environmentally acceptable
- sufficient energy over the suitable frequency range
- repeatable
Slide 2:
Land seismic sources
Explosives: - usually detonated in boreholes or buried
PROS
- sharp, impulsive, high amplitude (mostly P-wave)
- reasonably cheap
CONS
- The signal is not repeatable
- slow (borehole drilling)
- can be destructive
Presentation on REFRACTION PATHS - Single Horizontal Refractor of Seismic Method in Exploration Geophysics course, Department of Geological Sciences, Jahangirnagar University, Dhaka, Bangladesh. The presentation was conducted through ZOOM app during Corona pandemic in 2021.
SBAS-DInSAR processing on the ESA Geohazards Exploitation PlatformEmmanuel Mathot
In the context of space-borne geodetic techniques, Differential Synthetic Aperture Radar Interferometry (DInSAR) has demonstrated its high performance in measuring surface displacements in different conditions and scenarios, both natural and anthropic. In particular, the advanced DInSAR time series processing method referred to as Small BAseline Subset (SBAS), that allows studying both the spatial and temporal variability of the surface displacements, has proven to be particularly suitable in different contexts, as for natural hazards (volcanoes, earthquakes and landslides) and human-induced deformation (subsidence due to aquifer exploitation, mining operations, and building of large infrastructures). Recently, an efficient implementation of this algorithm (referred to as P-SBAS approach) has been fully integrated within the ESA’s Grid Processing on Demand (G-POD) environment, which is part of the [Geohazards Thematic Exploitation Platform (GEP)](https://geohazards-tep.eo.esa.int/#!) of ESA. The GEP is devoted to the exploitation of EO data resources in the context of the Geohazard Supersites & Natural Laboratories as well as on the CEOS Pilots on Seismic Hazards and Volcanoes. The GEP is sourced with elements, data and processing, including P-SBAS, relevant to the geohazards theme. The integration of the P-SBAS algorithm within GEP resulted in a web-based tool freely available to the scientific community. This tool allows users to process, from their own laptops, the European SAR data archives (ERS, ENVISAT and Sentinel-1) for obtaining surface displacement maps and time series in a completely unsupervised way, without caring about data download and processing facility procurements. The workshop is organized in four parts. First, a short overview on the DInSAR processing methods allowing retrieving mean surface deformation maps and displacement time series will be provided, with a specific focus on the SBAS-DInSAR technique. Secondly, the GEP and G-POD environments will be introduced and the P-SBAS web tool will be presented. The third and the fourth parts are dedicated to the advanced features and to case studies and results achieved via the web tool, respectively.
geophysics seismic waves ,its types, particle motion in S P ans surface waves. Travel time graph . critically refracted , direct and reflected wave arrivals. what is critical distance and crossover distance. relation between critical refracted ,direct and reflected waves.Elastic constants like bulk modulus shear , young's modulus and poisson's ratio. Lame's constant.
Ultrasonic guided wave techniques have great potential for structural health monitoring applications. Appropriate mode and frequency selection is the basis for achieving optimised damage monitoring performance.
In this paper, several important guided wave mode attributes are
introduced in addition to the commonly used phase velocity and group velocity dispersion curves while using the general corrosion problem as an example. We first derive a simple and generic wave excitability function based on the theory of normal mode expansion and the reciprocity theorem. A sensitivity dispersion curve is formulated based on the group velocity dispersion curve. Both excitability and sensitivity dispersion curves are verified with finite element simulations. Finally, a
goodness dispersion curve concept is introduced to evaluate the tradeoffs between multiple mode selection objectives based on the wave velocity, excitability and sensitivity.
Observation of gravitational waves from a binary black hole mergerSérgio Sacani
On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave
Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in
frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0 × 10−21. It matches the waveform
predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the
resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a
false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater
than 5.1σ. The source lies at a luminosity distance of 410þ160
−180 Mpc corresponding to a redshift z ¼ 0.09þ0.03 −0.04 .
In the source frame, the initial black hole masses are 36þ5
−4M⊙ and 29þ4
−4M⊙, and the final black hole mass is
62þ4
−4M⊙, with 3.0þ0.5 −0.5M⊙c2 radiated in gravitational waves. All uncertainties define 90% credible intervals.
These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct
detection of gravitational waves and the first observation of a binary black hole merger
The current study examines the generation and propagation of a Third order solitary water wave along
the channel. Surface displacement and wave profi le prediction challenges are interesting subjects in the
fi eld of marine engineering and many researchers have tried to investigate these parameters. To study the
wave propagation problem, here, fi rstly the meshless Incompressible Smoothed Particle Hydrodynamics
(ISPH) numerical method is described. Secondly,
Linear inversion of absorptive/dispersive wave field measurements: theory and...Arthur Weglein
The use of inverse scattering theory for the inversion of viscoacoustic wave field
measurements, namely for a set of parameters that includes Q, is by its nature very
different from most current approaches for Q estimation. In particular, it involves an
analysis of the angle- and frequency-dependence of amplitudes of viscoacoustic data
events, rather than the measurement of temporal changes in the spectral nature of
events. We consider the linear inversion for these parameters theoretically and with
synthetic tests. The output is expected to be useful in two ways: (1) on its own it
provides an approximate distribution of Q with depth, and (2) higher order terms in
the inverse scattering series as it would be developed for the viscoacoustic case would
take the linear inverse as input.
We will begin, following Innanen (2003) by casting and manipulating the linear
inversion problem to deal with absorption for a problem with arbitrary variation of
wavespeed and Q in depth, given a single shot record as input. Having done this, we
will numerically and analytically develop a simplified instance of the 1D problem. This
simplified case will be instructive in a number of ways, first of all in demonstrating
that this type of direct inversion technique relies on reflectivity, and has no interest in
or ability to analyse propagation effects as a means to estimate Q. Secondly, through
a set of examples of slightly increasing complexity, we will demonstrate how and where
the linear approximation causes more than the usual levels of error. We show how
these errors may be mitigated through use of specific frequencies in the input data,
or, alternatively, through a layer-stripping based, or bootstrap, correction. In either
case the linear results are encouraging, and suggest the viscoacoustic inverse Born
approximation may have value as a standalone inversion procedure.
Evaluation of the Sensitivity of Seismic Inversion Algorithms to Different St...IJERA Editor
Seismic wavelet estimation is an important step in processing and analysis of seismic data. Inversion methods as Narrow-Band and theConstrained Sparse-Spike ones require information about it so that the inversion solution, once it is not a unique problem, may be restricted by comparing the real seismic trace with the synthetic generated by convolution of the estimated reflectivity and wavelet. Besides helping in seismic inversion, a good estimate of the wavelet enables an inverse filter with less uncertainty to be computed in the deconvolution step and while tying well logs, a better correlation between the seismic trace and well log can be achieved. Depending on the use or not of well log information, the methods of wavelet estimation can be divided into two classes: statistical and deterministic. This work aimed to test the sensitivity of acoustic post-stack seismic inversion algorithms to wavelets statistically estimated by two distinct methods
Investigatng MultIfractality of Solar Irradiance Data Through Wavelet Based M...CSCJournals
It has been already revealed that the daily Solar Irradiance Data during the time period from October, 1984 to October, 2003 obtained by Earth Radiation Budget Satellite (ERBS) exhibits an Anti-persistent trend having multi-periodic phenomena. The solar irradiance time series data being a complex non linear signal in this paper we have tried to detect the irregularity and multifractality in the signal using continuous wavelet transform modulus maxima(WTMM) algorithm. Singularity spectrum of the signal has been obtained to measure the degree of multifractality of the Solar Irradiance signal.
Similar to Seismic velocity analysis in Anisotropic media (20)
Here is a new 9-point scheme for finite difference solution of acoustic waves in frequency domain. The algorithm honors both accuracy and computational efficiency.
Our eyes have different responses to the different coloured patterns. Therefore, it is crucial to get a different colour map for kinds of seismic interpretation tasks as well as other fields of science such as astronomical interpretations.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
2. Moveout velocity approximation (Thomsen, 1986)
Nonhyperbolic reflection moveout in anisotropic media (Tsvankin and Thomsen 1994)
Normal moveout from dipping reflectors in anisotropic media (Tsvankin, 1995)
Velocity analysis for transversely isotropic media, (Alkhalifah and Tsvankin, 1995)
Velocity analysis using non-hyperbolic moveouts in transversely isotropic media (Alkhalifah, 1997)
Nonhyperbolic moveout analysis in VTI media using rational interpolation (Douma and Calvert, 2006)
Generalized moveout approximation (GMA) (Fomel and Stovas , 2010)
The modified generalized moveout approximation: a new parameter selection (Stovas and Fomel,
2016)
3. The concept of anisotropy
Physical
properties look
the same in all
directions
Measurements
in any direction
have the same
result
Isotropic
material
Physical
properties are
not the same in
all directions
Measurements
in different
directions have
different results
Anisotropic
material
Transverse isotropy (TI)
Symmetric axis
transversely isotropic with a
Vertical symmetry axis (VTI)
transversely isotropic with a
Horizontal symmetry axis
(HTI)
transversely isotropic with a
Tilted symmetry axis (TTI)
7. 7
He measured the anisotropy from a comparison of the
well-log sonic data and the interval velocity profile obtained
from the surface seismic data and also from a comparison of
the seismic depth and the well-log depth and concluded that
depth anomaly in the North Sea basin is caused by the
velocity anisotropy of shale
By comparing layer thicknesses from
S-wave data with thicknesses from P-wave data. When the S-
wave thicknesses were significantly greater than
the P-wave (i.e., outside the range of expected errors), He
concluded that the layer was anisotropic.
He showed that anisotropy should be taken into account in
amplitude-offset studies involving shales.
They showed that for only one of the transversely isotropic
media considered here-shale-limestone-would v(z) DMO fail
to give an adequate correction within CMP gathers. For the
shale-limestone, fortuitously the constant-velocity DMO
gives a better moveout correction than does the v(z) DMO
8. The standard hyperbolic approximation for reflection moveouts in
layered media is accurate only for relatively short spreads, even if the
layers are isotropic (Taner and Koehler, 1961).
Velocity anisotropy may significantly enhance deviations from
hyperbolic moveout ( Liakhovitsky and Nevsky, 1971; Thomsen,
1986).
Hyperbolicassumption
analysis(anisotropicmedia)
Kery and Helbig
(1956)
Liakhovitsky and
Nevsky (1971)
Levin (1978,
1979, 1989)
Thomsen (1986)
Sheriff and
Seriram (1991)
Long
spread
studies
Radovich and Levin (1982):
TI leads to spread-length-dependent
moveout velocity.
Hake et al. (1984):
Suggested three-term Taylor series
expansion of 𝑡2 − 𝑥2 curves
Berge (1991)
Byun et al. (1989)
Byun and Corrigan (1990).
Tsvankin and Thomsen 1994, Nonhyperbolic reflection moveout in anisotropic media
9. 9
Short-spread reflection moveout
Short-spread
limit
for all three waves the short spread
moveout velocity is generally different
from the true vertical velocity.
Winterstein (1986):
assumed small value of 𝛿 in order to estimate
𝛾.
Banik (1984):
Found significant difference between vertical
P-wave velocities and moveout velocities in
North Sea shales.
SV-wave may be more significantly
distorted by anisotropy than that for P-
wave.
10. 10
Elliptical anisotropy assumption
wavefront is spherical for the SV-wave
and elliptical for P-wave
all moveouts are strictly hyperbolic
(Levin, 1978).
the elliptical anisotropy is a good
assumption for mathematical treatments.
However, the physics of real media says
𝜀 ≠ 𝛿.
Difference between the exact travel-
times and best-fit hyperbola
Tsvankin and Thomsen 1994, Nonhyperbolic reflection moveout in anisotropic media
We can introduce Deviation from
elliptical case (next slides)
11. 11
Intermediate-spread reflection moveout
Difference between the exact
travel-times and best-fit
hyperbola (Intermediate spread)
The Effective moveout velocity
of the best hyperbola normalized
by short spread moveout velocity
Tsvankin and Thomsen 1994, Nonhyperbolic reflection moveout in anisotropic media
12. 12
Intermediate-spread reflection moveout-weak
anisotropy approximation (WAA)
Tsvankin and Thomsen, 1994
Weak anisotropy approximation (Byun
et al, 1989 )
𝑡2
𝑧
𝑉𝛾
2
+
𝑥
2𝑉ℎ
2
𝑥2
𝑧2 +
𝑥
2
2
require knowledge of vertical P-and S-
wave velocities.
Sena
(1991)
The WAA cannot explain some the pronounced deviation of the
SV-wave moveout from hyperbolic for 𝜎 < 0.
13. 13
On limitation of WAA
The second term may be
considered as the correction for
“strong” anisotropy.
WAA coefficients
14. 14
For very small values of
𝛿 𝑎𝑛𝑑 𝜎, WAA breaks down.
since usually 𝜎 > 𝛿, the WAA
is less suitable for the SV-wave
than for the P-wave.
Measure of inaccuracy of the conventional
hyperbolic moveout equation:
16. 16
Long spread reflection moveout
the three-term Taylor series provides
valuable results into peculiarities of non-
hyperbolic moveouts.
the three-term Taylor series loses
accuracy rapidly with increasing offset.
Three-term Taylor series 𝑡 𝑇 and
approximation 𝑡 𝐴 for P-wave moveout
Considering large offset to depth ratio
(large incidence angles)
17. 17
Normal moveout from dipping reflectors in anisotropic media (Tsvankin, 1995)
Coincides with Thomsen’s (1986)
Agrees with Byun (1982) and Uren et al. (1990b)
18. 18
Comparison with Byun, 1984
P-wave moveout velocity calculated by Tsvankin formula
(dotted curve) and from travel-times (solid curve) for the
limestone-sandstone model from Byun (1984) .
P-wave moveout velocity calculated by Byun, 1984
19. 19
How many parameters determine the P-wave DMO signature?
𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑉𝑝0
𝑉𝑠0
, 𝜀 , 𝛿
𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 𝑉𝑝0 , 𝜀 , 𝛿
The effect of 𝑉𝑠0The effect of 𝑉𝑝0
In VTI media the dip dependence of the P-wave NMO velocity is
primarily a function of 𝜀 𝑎𝑛𝑑 𝛿.
20. 20
The weak-anisotropy expression for the P-wave normal-moveout
velocity is sufficiently accurate for common small and moderate
values of 𝜀 and 𝛿.
Dip dependence of the P-wave moveout velocity for Vnmo
media is a function of only two parameters-𝜀 and 𝛿, with the
influence of the S-wave vertical velocity being practically
negligible.
The P-wave DMO signature is controlled, to a significant degree, by
the difference 𝜀 − 𝛿
If 𝜀 − 𝛿 < 0.15 − 0.2 non-hyperbolic moveout does not
seriously distort the P-wave moveout velocity on conventional
length spreads, even for steep reflectors.
This conclusion is the base
of many alternative
approaches.
21. 21
Velocity analysis for transversely isotropic media, Alkhalifah and Tsvankin, 1995.
The main difficulty in extending seismic processing
to anisotropic media is the recovery of anisotropic
velocity fields from surface reflection data.
Analytic and numerical analysis performed by
Tsvankin(1995) shows that dip-dependence of P-
wave NMO velocities is mostly controlled by 𝜀 − 𝛿.
Alkhalifah and Tsvankin (1995) extended the NMO velocity
relation derived by Tsvankin (1995) by including ray
parameter.
they showed that P-wave NMO velocity for dipping
reflectors in homogenous VTI media depends just on
𝑉𝑁𝑀𝑂(0) and new parameter 𝜂.
A 3D plot of NMO velocity
as a function of 𝜀 and 𝛿
22. 22
Velocity analysis for transversely isotropic
media, Alkhalifah and Tsvankin, 1995.
Field data example
Time migrated seismic line (offshore Africa)
Constant velocity stacks
(without accounting anisotropy)
Constant velocity stacks (with
accounting anisotropy)
23. 23
Dellinger et al. 1993, Anelliptic
approximation for TI media.
first anelliptic approximation:
the variation in P-wave phase slowness is described
in terms of three parameters:
𝑣ℎ, 𝑣𝑣 𝑎𝑛𝑑 𝑠ℎ𝑜𝑟𝑡 𝑠𝑝𝑟𝑒𝑎𝑑 𝑉𝑁𝑀𝑂 .
second anelliptic approximation: adds the
vertical moveout velocity as an additional free
parameters.
Sayers, 1995, Anisotropic velocity analysis.
examined the method of Dellinger and showed
that the method is suitable for TI media for small
anellipticity.
he provided new approach based an expansion of
the inverse-squared group velocity in spherical
harmonics.
for TI media with small anisotropy his method
reduces to the method of Byun et.al (1989).
the method does, however, require the use of
borehole measurements such as sonic logs or
VSP measurements to constraints the vertical
velocity.
24. 24
Alkhalifah, 1997, Velocity analysis using non-hyperbolic moveouts in transversely
isotropic media.
the method proposed by Tsvankin (1994) ,Alkhalifah and Tsvankin (1995)
works only when reflectors with at least two distinct dips are present, as long
as one of the dips is not close to 90 degree.
Alkhalifah (1997) used non-hyperbolic moveout in order to estimate 𝜂 and
discussed about the sensitivity of the inversion to errors in the measured
errors.
He also applied semblance analyses over non-hyperbolic trajectories to
estimate both 𝑉𝑁𝑀𝑂 𝑎𝑛𝑑 𝜂.
Tsvankin (1994)
Tsvankin
And Alkhalifah
(1995)
Now the velocity analysis and
inversion requires 2 parameter
searching.
25. 25
Alkhalifah, T., Velocity analysis using non-hyperbolic moveouts in transversely
isotropic media.
Three layer model, the
first layer is isotropic
Percent time error in moveout
(departure from the exact moveout)
Alkhalifah, 1997
Tsvankin and
Thomsen, 1995
Modified Hake
et al. 1984
Some notes:
I. The derived equations reduce to
isotropic case when 𝜂 = 0.
II. the value of 𝜂 𝑒𝑓𝑓 also can be used
to describe the departure from
hyperbolic moveouts caused by
inhomogeneity in isotropic layered
media.
26. 26
Alkhalifah, T., Velocity analysis using non-hyperbolic moveouts in transversely isotropic media.
Degree of non-hyperbolic based on 𝜂 𝑒𝑓𝑓??
Values of 𝜂 𝑒𝑓𝑓 in an isotropic medium with a constant
velocity gradient, as a function of zero-offset time 𝑡0, for three
values of velocity gradient a.
one cannot distinguish between the amount
of non-hyperbolic moveout attributable to
anisotropy and that attributable to
inhomogeneity
medium, with large vertical inhomogeneity,
were strictly isotropic (𝜀 = 0 and 𝛿 = 0 in each
layer), then apprximately 𝜂 𝑒𝑓𝑓 = 0.06.
In the presence of anisotropy resulted in
𝜂 𝑒𝑓𝑓 = 0.19.
27. 27
Velocity analysis for transversely isotropic media, Alkhalifah and Tsvankin, 1995.
Velocity analysis for various offset to depth ratios (based on hyperbolic
moveout)
Velocity analysis panels for various offsets
a) 𝜂 = 0
b) 𝜂 = 0.1
30. 30
Douma and Calvert, 2006, Nonhyperbolic moveout analysis in VTI
media using rational interpolation.
studied the accuracy of the nonhyperbolic moveout equation
of Alkhalifah and Tsvankin (1995).
they used rational interpolation to approximate
nonhyperbolic moveout in a VTI media.
They showed the their approximation has close accuracy to
that method proposed by Fomel (2014).
31. 31
Douma and Calvert, 2006, Nonhyperbolic moveout analysis in VTI
media using rational interpolation.
Semblance scans and moveout-corrected gathers
True model parameters
Estimated model parameters
Conventional
nonhyperbolic
moveout
Rational
interpolation
method
32. 32
Fomel and Stovas , 2010, Generalized moveout approximation (GMA),
GMA:
A Five parameter approximation based on two rays with two
offset (x=0, x=X).
The parameters of original GMA are the travel time,
the second-order travel-time derivative, and the fourth-order
travel-time derivative computed at a zero-offset ray and the
travel time and first-order travel-time derivative computed
from a reference ray.
Calculated based on zero
offset ray
Defined from a reference ray
33. 33
Fomel and Stovas , 2010, Generalized moveout approximation (GMA),
Relative absolute error of different
traveltime approximations as a function
of velocity contrast and offset/depth ratio
for the case of a linear velocity model.
Relative absolute error of different
traveltime approximations as a function
of velocity contrast and offset/depth ratio
for the case of circular reflector.
34. 34
Fomel and Stovas , 2010, Generalized moveout approximation (GMA),
Dots:
Exact moveout from ray tracing in the one-dimensional
anisotropic Marmousi model
solid lines:
different approximations
35. 35
basic theory of anisotropic wave propagation
Influence of anisotropy on point-source radiation
and AVO analysis
Normal-moveout velocity in layered anisotropic
media
Nonhyperbolic reflection moveout
Reflection moveout of mode-converted waves
P-wave time-domain signatures in transversely
isotropic media
Velocity analysis and parameter estimation for VTI
media
P-wave imaging for VTI media
36. 36
Stovas and Fomel, 2016, Modified GMA
Same as GMA, but changes the definition of
parameter A:
defined from the second derivative of travel
time with respect to offset from a reference ray.
The relative error in the
estimation of travel-time curve
The error in the estimation of travel-time
curve versus offset/depth ratio for the
stack of VTI layers.