This presentation is about the transcription machinery that is required for the transcription in eukaryotes. The comparison between the transcription factors involved in prokaryotes and eukaryotes. The initiation of transcription and how it helps in producing a mRNA.
This presentation is about the transcription machinery that is required for the transcription in eukaryotes. The comparison between the transcription factors involved in prokaryotes and eukaryotes. The initiation of transcription and how it helps in producing a mRNA.
Principles of inheritance & Variation-IVChethan Kumar
The topic of discussion here is about Mutation & different types of mutation in organism, their effects & Mutational theory of evolution. Further the changes in the Number of chromosomes due to mutation and its effects & Mendelian disorders & their patterns of inheritance including the numerical abberations in chromosomes & the disorders associated with it.
A chromosomal disorder, anomaly, aberration, or mutation is a missing, extra, or irregular portion of chromosomal DNA. It can be from a typical number of chromosomes or a structural abnormality in one or more chromosomes. Chromosome mutation was formerly used in a strict sense to mean a change in a chromosomal segment, involving more than one gene. The term "karyotype" refers to the full set of chromosomes from an individual.
A chromosome abnormality, disorder, anomaly, aberration, or mutation is a missing, extra, or irregular portion of chromosomal DNA. It can be from an atypical number of chromosomes or a structural abnormality in one or more chromosomes
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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...!
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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 .
2. FRAME SHIFT MUTATIONS
> A frame shift mutations also called a framing error or reading frame shift.
>It is a genetic mutations caused by the addition or deletion of nitrogenous base
in DNA or MRNA are known as frame shift mutations.
>Because these shifts the reading frame of codons from the site of change
onward on deletion may be neutralized by one addition or vice versa.
3. TYPES OF FRAME SHIFT MUTATIONS
There are two types of frame shift mutations
1.Deletions mutations:- These mutations are caused due to the loss or deletion of
one or more nucleotides.
2.Insertion mutations: These mutations are caused by the addition of one or more
extra nucleotides in a DNA molecule at one or more places.
4. MECHANISM OF ORIGIN OF FRAME SHIFT
MUTATIONS
>Acridine dyes have been found to cause deletion or insertion of a single base
pair.Acridines like 5-aminoacridine and proflavin become intecalated between two
adjacent purinces and increase the distance between them from 3.4A to 6.8A.At
the time of DNA replication,either a nitrogenous base pair is introduced in the gap
or a nitrogenous base pair is lost.
>Frame shift mutations caused by the deletions are also introduced by the
removal of ethylated bases.
5. MUTATIONS DUE TO CHROMOSOME
ABERRATION
>The occasional breaks in the chromosomes and fusion of the broken ends
causes many changes in the chromosomes called chromosomal aberrations.
>Likewise chromosomal aberrrations are also the kinds of mutations produced as
a result of segmental change in the chromosome.
>These were observed of C.B Bridges and A.H Sturtevant in Drosophila as early as
1923.The Breaks may occur either in single chromosome,in a pair or in non-
homologous chromosomes.
6. >The structural changes in the chromosomes are of various types these changes
may involve either the loss of broken fragments of chromosome or addition of
same fragment.
>In more complicated changes segments get exchanged between two different
chromosomes being termed as translocatons.Thus,in brief stuctural changes may
be of following types:
1.Translocations.
2.Deletions.
3.Duplications(repeats).
4.Inversions
7. 1.Translocations:- Translocations is the transfer of a portion of one chromosome to
a non-homologous chromosome.At present,a variety of translocations are
recognized which fall among the following three categories.
(i)Simple translocation:-These involve a single break in the chromosomes and the
transfer of broken piece of this chromosome to the end of another.since the terms of
unbroken chromosomes are nonsticky,such terminals chromosome attachment are
rarely,if ever found
8. (ii)Shift:- These involve three breaks and the transfer of a two break section of one
chromosome within the break produced in a nonhomologous chromosomes.Shift
are more common than simple translocations.
9. (iii)Reciprocal translocation or inter changes:- These are produced by single breaks
in two homologous chromosoe an exchange of chromosome section between
them,these are the most frequent and best studied translocation.
10. 2.Deletion
>Deletion is the loss of a chromosomal segment from any chromosome.Depending
upon the length of the lost chromosomal segment,the loss of genes involved may very
from sigle genes to block containing several gennes.
>The loss of chromosomal segment occurs when a portion of chromosome gets
detached due to certain reasons and the lost segment does not survive because it
lacks the centromere.
>The portion of the chromosome carrying the centromere fucntion as a genetically
defficient chromosome.
11. TYPES OF DELETIONS
1.Terminal deletions:- To the loss of segment from one or the other end of
chromosomes.The terminal acentric part of the chromosome is unable to survive and
causes terminal deletion.The terminal deletion is,caused by a single breks in a
chromosome.
2.Intercalary or Intestitial deletion: It denotes the loss of an intercalary segment of the
chromosomes with the reunion of terminal segments.The intercalary deletion is
characterised by two point breaks and the reunion of terminal parts.
12. 3.Duplication
>Sometimes a segment or a part of the chromosomes becomes repeated in the same
chromosomes.These additional duplicated segments are called duplications.
>They arise as a result of unequal crossing over between chromosomal segments.
>In Drosophila mutant bar eyes which are narrow and constricted are due to small
duplicated genes.
>It was observed that each additional duplicate segments made the eye smaller and
smaller.Sometimes duplications when act in opposite direction serve as supressors.
13. 4.Inversion
>Inversion is a kind of chromosomes aberration in which a chromosomal segment
exist in reverse relationship to the rest of its chromosomes.
>Inversions are beleived to arise by breakages at the point of intersection of a
chromosome loop and reunion with new partners.
>Any organism may be homozygous or heterozygous for an inversion.During
meiosis,inversion heterozygotes synapse by forming a looped configuration.
>In salivary gland chromosomes and other favourable material,an material,an inversion
loop makes it possible to determine with precision the extent of the aberration.
14. Types of Inversion
1.Paracentric inversion:- A single crossing over or an odd number of crossovers in the
inverted region will result into the formation of a dicentric chromosome(having two
centromeres) and an acentric chromosome(with no centromere).Of remaining two
chromatids one will be normal and the other will carry the inverison.
2.Pericentric inversion:- In a pericentric inversion(where centromere is present within
the inverted segment),although at pachytene,the configuration observed is similar to to
those describedabove for paracentric inversion,the products of crossing over the
configuraions at subsequent stages of meiosis differ,In the case,two of four
chromatids resulting after meiosis will have deficiencies and
duplications.However,unlike paracentric inversion,no dicentric bridge or acentric
fragment will be observed.
