The document discusses the relational algebra and its fundamental operations. It describes relational algebra as the basic set of operations for the relational model that enable users to specify basic retrieval requests. The fundamental operations include unary operations like select and project, and binary operations like union, intersection, set difference, cartesian product, join, and outer join. Each operation is explained along with examples of how it is denoted and used.
This presentation educates you about the basic operations of python with the operators example. operations are Arithmetic Operators, Comparison (Relational) Operators, Assignment Operators, Logical Operators, Bitwise Operators, Membership Operators, Identity Operators.
For more topics stay tuned with Learnbay.
This presentation educates you about the basic operations of python with the operators example. operations are Arithmetic Operators, Comparison (Relational) Operators, Assignment Operators, Logical Operators, Bitwise Operators, Membership Operators, Identity Operators.
For more topics stay tuned with Learnbay.
This presentation educates you about R - Operators, Types of Operators, Arithmetic Operators, Logical Operators, Relational Operators, Assignment Operators and Miscellaneous Operators.
For more topics stay tuned with Learnbay
It deals with various functional forms in regression along with the derivation and interpretation of the slope and elasticity values of each of the models. The frequently used models of log-lin, lin-log and log-log models are also adequately elaborated. The link of the MS powerpoint used in this video is also given separately as a pinned comment.
This presentation educates you about R - Operators, Types of Operators, Arithmetic Operators, Logical Operators, Relational Operators, Assignment Operators and Miscellaneous Operators.
For more topics stay tuned with Learnbay
It deals with various functional forms in regression along with the derivation and interpretation of the slope and elasticity values of each of the models. The frequently used models of log-lin, lin-log and log-log models are also adequately elaborated. The link of the MS powerpoint used in this video is also given separately as a pinned comment.
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.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
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 .
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.
(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.
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.
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.
2. The Relational Algebra:
Relational algebra is the basic set of operations for the
relational model
These operations enable a user to specify basic retrieval
requests (or queries)
The result of an operation is a new relation, which may
have been formed from one or more input relations
3. The fundamental operations in the
relational algebra:
Unary operations: are called unary operations, because they operate on
one relation.
▫Select.
▫Project.
Binary operations: operate on pairs of relations and are, therefore, called
binary operations.
▫Union.
▫Intersection
▫set difference.
▫Cartesian product.
4. 1- The Select Operation
The select operation selects tuples that satisfy a given
predicate.
We use the lowercase Greek letter sigma (Ϭ) to denote
selection
In general, the SELECT operation is denoted by
σ<selection condition>(R)
5. To select tuples of the instructor relation where the instructor is in the “Physics”
department, we write:
Ϭ dept_name =“Physics” (instructor )
•The Result will be
9. 3- The Union Operation
For a union operation r ∪ s to be valid, these two conditions must be
hold:
The relations r and s must have the same number of attributes.
The domains of the ith attribute of r and the ith attribute of s must be
the same, for all i.
10.
11.
12.
13.
14. 4- The Intersection:
Intersection is denoted by ∩
The result of this operation, denoted by R ∩ S, is a
relation that includes all tuples that are in both R and S.
The attribute names in the result will be the same as the
attribute names in R
The two operand relations R and S must be “type
compatible”
15. 5- The Set-Difference Operation
The set-difference operation, denoted by (−)
allows us to find tuples that are in one relation but are
not in another.
The expression r − s produces a relation containing those
tuples in r but not in s.
16.
17. 6- The Cartesian-Product Operation
denoted by a cross (×).
allows us to combine information from any two relations.
We write the Cartesian product of relations r1 and r2 as r1
× r2.
25. Binary Relational Operations: Outer JOIN
Operation
The outer-join operation is an extension of the join
operation to deal with missing information.
Some tuples in either or both of the relations being joined
may be lost.
The outer join operation works in a manner similar to the
natural join operation but preserves those tuples that
would be lost in an join.
This is done by creating tuples in the result containing null
values.
26. Binary Relational Operations: Outer JOIN
Operation
There are three forms of the operation:
1. left outer join, denoted ⟕: takes all tuples in the left relation that did not match with any
tuple in the right relation, pads the tuples with null values for all other attributes from the right
relation, and adds them to the result of the natural join.
2. right outer join, denoted ⟖: is symmetric with the left outer join: It pads tuples from the right
relation that did not match any from the left relation with nulls and adds them to the result of
the natural join.
3. Full outer join ⟗: does both the left and right outer join operations, padding tuples from the
left relation that did not match any from the right relation, as well as tuples from the right
relation that did not match any from the left relation, and adding them to the result of the join.
