Definition - Rolling circle replication is a process of unidirectional nucleic acid replication.
* can rapidly synthesize multiple copies of circular molecules of DNA or RNA, such as plasmids.
* Eucaryotic also replicate.
* widely used in molecular biology & biomedical
nanotechnology, especially in the field of
biosensing (as a method of signal Amplification).
Steps:
Circular ds DNA will be “nicked”
3` end is elongated →Leading strand
5` end displaced → Lagging strand
made up of double stranded by OKAZAKI fragments.
4) Replication of both “ unnicked” and displaced ss DNA
5) Displaced DNA circulates and synthesis its own complementary strand.
Initation-- phosphate ends, by the action of:
a) Helicase
b) Topoisomerases
c) Single stranded binding proteins(SSBPs)
Elongation-OH group of broken strand, using the unbroken strand as a template. The polymerase will start to move in a circle for elongation, due to which it is named as Rolling Circle Model.
end will be displaced and will grow out like a waving thread.
Termination-* At the point of termination, the linear DNA molecule is cleaved from the circle resulting in a double stranded circular DNA molecule and a single- stranded linear DNA molecule.
* The linear single stranded molecule is circularized by the action of ligase and then replication to double stranded circular plasmid molecule.
Example- Conjugation of F+ and F- bacteria
Diagrammatic representation of Rolling circle
some Examples-Viral DNA
* Human herpes virus
* Human papilloma virus
* Geminivirus
Viral RNA
* pospiviridiae
* Avsunviridiae
Reference:- https://en. m. wikipedia.org
what- when- how.com
https//www.sciencedirect.com
www.slideshare.com
Genetics-notes.wikispace.com
you tube
Prescott 5th edition page.no: 236, 237
Brock biology of microorganism , page.no: 253,616
Definition - Rolling circle replication is a process of unidirectional nucleic acid replication.
* can rapidly synthesize multiple copies of circular molecules of DNA or RNA, such as plasmids.
* Eucaryotic also replicate.
* widely used in molecular biology & biomedical
nanotechnology, especially in the field of
biosensing (as a method of signal Amplification).
Steps:
Circular ds DNA will be “nicked”
3` end is elongated →Leading strand
5` end displaced → Lagging strand
made up of double stranded by OKAZAKI fragments.
4) Replication of both “ unnicked” and displaced ss DNA
5) Displaced DNA circulates and synthesis its own complementary strand.
Initation-- phosphate ends, by the action of:
a) Helicase
b) Topoisomerases
c) Single stranded binding proteins(SSBPs)
Elongation-OH group of broken strand, using the unbroken strand as a template. The polymerase will start to move in a circle for elongation, due to which it is named as Rolling Circle Model.
end will be displaced and will grow out like a waving thread.
Termination-* At the point of termination, the linear DNA molecule is cleaved from the circle resulting in a double stranded circular DNA molecule and a single- stranded linear DNA molecule.
* The linear single stranded molecule is circularized by the action of ligase and then replication to double stranded circular plasmid molecule.
Example- Conjugation of F+ and F- bacteria
Diagrammatic representation of Rolling circle
some Examples-Viral DNA
* Human herpes virus
* Human papilloma virus
* Geminivirus
Viral RNA
* pospiviridiae
* Avsunviridiae
Reference:- https://en. m. wikipedia.org
what- when- how.com
https//www.sciencedirect.com
www.slideshare.com
Genetics-notes.wikispace.com
you tube
Prescott 5th edition page.no: 236, 237
Brock biology of microorganism , page.no: 253,616
DNA REPAIR PPT IN SHORT UNDER 15 PAGESPrihul Group
CONTENT
INTRODUCTION OF DNA REPAIR
WHY DOES DNA REPAIR REQUIRED?
TYPES OF DNA REPAIR
MECHANISM OF DNA REPAIR
APPLICATION OF DNA REPAIR
CONCLUSION
INTRODUCTION
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome.
The DNA repair ability of a cell is vital to the integrity of its genome and thus to the normal functionality of that organism.
A failure to repair DNA produces a mutation.
presented by HAFIZ M WASEEM
university of education LAHORE Pakistan
i am from mailsi vehari and studied in lahore
bsc in science college multan
msc from lahore
DNA repair system lecture that were prepered by Ph.D. students Mohammed Mohsen and Aliaa Hashim at microbiology department / college of medicine / babylon university.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
DNA damage and_repair
1. UNIVERSITY OF RAJASTHAN
SUBMITTED TO:
STANI MEMORIAL PG COLLEGE, JAIPUR
DNA REPAIR
SUBMITTED BY :
DR. RAKHI SHARMA
HOD ZOOLOGY
SUNIDHI
M.SC ZOOLOGY(PRE.)
2017-18
2. INTRODUCTION:
Genetic variations are important for evolution but the survival of the
individual demands genetic stability. Maintaining genetic stability
requires an extremely accurate mechanism for replicating DNA and
mechanism for repairing the many accidental lesions that occur
continually in DNA.
Most such changes are temporary because they are immediately
corrected by a set of processes that are collectively called as DNA
repair.
3. CONTENTS:
• Double helical structure of DNA
• DNA damage
• Sources of DNA damage
• Causes of DNA damage
• Consequence of DNA damage
• DNA repair
• Direct repair
• Excision repair
• Mismatch repair
• Recombinational repair
• References
5. DNA DAMAGE:
DNA damage is the alteration in the chemical structure of DNA,
such as a break in a strand of DNA, a base missing from the
backbone of DNA, a chemically changed base.
Damage to DNA that occurs naturally can result from metabolic or
hydrolytic processes.
6. SOURCES OF DNA DAMAGE:
• Endogenous damage:
It includes damage from within the cell.
It also includes replication errors.
Example: Attack by reactive oxygen species produced from normal metabolic byproducts.
• Exogenous damage:
It includes damage caused by external agents.
Examples: 1.UV, X rays and gamma rays.
2.Plants of comfrey species.
3.Viruses.
7. CAUSES OF DNA DAMAGE:
• UV Rays:
Random photons of ultraviolet light induce aberrant bonding between neighbouring
pyrimidines(thymine and cytosine) bases on the same strand of DNA. This will prevent the
replication.
8. CONTD…
• Alkylating agents:
Methyl and ethyl group added to DNA bases alters the structure of DNA.
• Deamination:
An amino group of cytosine is removed and the base becomes uracil.
An amino group of adenine or guanine is removed and the base becomes hyoxanthine.
10. CONSEQUENCES OF DNA DAMAGE:
• Leads to genome instability.
• Increased cancer risk.
• Accelerated ageing.
• Neurodegenerative diseases.
11. • DNA repair refers to the number of processes by which a cell
identifies and corrects damage to the DNA molecules that encode
its genome.
• Depending on the type of damage inflicted on DNA‘s double
helical structure, a variety of repair strategies have evolved to
restore lost information.
DNA REPAIR :
12. TYPES OF DNA REPAIR MECHANISMS:
1. Direct reversal
2. Excision repair
a) Base excision repair
b)Nucleotide excision repair
3. Mismatch repair
4. Recombinational repair
13. DIRECT REPAIR:
• This system act directly on damaged nucleotides and convert each
one back to its original structure.But only a few damaged
nucleotides can be repaired directly.
• Pyrimidine dimers are repaired by a light-dependent direct system
called photoreactivation.
15. EXCISION REPAIR:
• It involves excision of a segment of the polynucleotide containing a
damage site, followed by resynthesis of the correct nucleotide
sequence by a DNA polymerase.
• Excision → Resynthesis → Ligation.
• Excision repair is of two types:
a)Base excision repair
b) Nucleotide excision repair
16. BASE EXCISION REPAIR:
• BER repairs damage to a single base caused by oxidation, alkylation,
hydrolysis, or deamination.
• The damaged base is removed by a DNA glycosylase, resynthesized
by a DNA polymerase, and a DNA ligase performs the final nick-
sealing step.
18. NUCLEOTIDE EXCISION REPAIR:
• Nucleotide excision repair
recognizes bulky helix-
distorting lesions such as
pyrimidine dimers and 6,4
photoproducts and treats
them.
19. MISMATCH REPAIR:
• Mismatch repair corrects errors of DNA replication and
recombination that results in mispaired but undamaged
nucleotides.
20. RECOMBINATIONAL REPAIR:
• Recombinational repair requires the presence of an identical or
nearly identical squence to be used as a template for repair of the
break in the DNA strand.
• The enzymatic machinery responsible is nearly identical to the
machinery responsible for chromosomal crossover during meiosis.
