Lipids are a diverse group of compounds that include fats, oils, waxes, sterols like cholesterol, and phospholipids. They serve important structural and storage roles in cells and transport of fat-soluble vitamins and other compounds. Lipids are classified based on their structure as simple, compound, or derived lipids.
Lipids may be regarded as organic substances which is insoluble in water, soluble in organic solvents (alcohol , ether etc.), Triacylglycerols (formerly triglycerides) are the esters of glycerol with fatty acids.
Lipids may be regarded as organic substances which is insoluble in water, soluble in organic solvents (alcohol , ether etc.), Triacylglycerols (formerly triglycerides) are the esters of glycerol with fatty acids.
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.
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.
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/
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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
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.
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 .
2. Definition,
biological importance and classification.
Fats and fatty acids.
Introduction to compound lipids.
Hydrophobic and hydrophilic groups.
Cholesterol.
Bile salts.
Micelle.
Bimolecular leaflet
3. Any member of a large and diverse group of
oils, fats, and fat like substances that occur in
living organisms and that characteristically
are soluble in organic solvents but only
sparingly soluble in aqueous solvents.
Lipids are not polymers, but mostly small
molecules.
Chief cellular storage form of energy
Role in cellular structure and biochemical
functions
4. Fat-soluble vitamins
Essential fatty acids contained in the fat of natural
foods
Stored in adipose tissue,
◦ thermal insulator in the subcutaneous tissues and around
certain organs
Myelinization : electrical insulators, allowing rapid
propagation of depolarization waves along myelinated
nerves.
Lipoproteins : Combinations of lipid and protein -
important cellular constituents, occurring both in the
cell membrane and mitochondria.
Means of transporting lipids in the blood.
Obesity, diabetes mellitus, atherosclerosis
Role of various polyunsaturated fatty acids in nutrition
and health.
5.
6. The lipids are classified as:
◦ Simple lipid/Homo Lipids
◦ Complex lipid/Compound/Hetero Lipids
◦ Precursor and Derived Lipids
7. Esters of fatty acids with various alcohols.
◦ Fats: Esters of fatty acids with glycerol. Oils are fats
in the liquid state.
◦ Waxes: Esters of fatty acids with higher molecular
weight monohydric alcohols.
8. Simplest form of lipids
Carboxylic acids with HC side chain
Usually contains an even number of carbon atoms
(14C- 20C) – biosynthesis of fatty acid occurs with
sequential addition of 2 carbon atom.
Chain may be saturated (containing no double
bonds) or unsaturated (containing one or more
double bonds)
It occurs mainly in esterified form.
Fats of animal origin are more simple than that of
plant origin.
Palmitic acid and stearic acid – most common
9.
10.
11. Fatty acids may be further subdivided as follows
◦ Monounsaturated (monoethenoid, monoenoic)
acids, containing one double bond.
◦ Polyunsaturated (polyethenoid, polyenoic) acids,
containing two or more double bonds.
◦ Eicosanoids: These compounds, derived from
eicosa- (20-carbon) polyenoic fatty acids, comprise the
prostanoids, leukotrienes (LTs) and lipoxins (LXs).
Prostanoids include prostaglandins (PGs), prostacyclins
(PGIs), and thromboxanes (TXs).
12. The fatty acid cant be synthesized by the body
and therefore has to be supplied in the diet.
Ex: Linoleic Acid, Linolenic Acid
Archidonic acid becomes essential – precursor
linoleic acid is not provided in the diet
Functions of EFA
◦ Membrane structures and functions
◦ Transport of cholesterol
◦ Formation of lipoprotein
◦ Prevention of fatty liver
• Deficiency of EFA: Phrynoderma – toad skin
13. Also known as
triglycerides
Main storage of fatty acids
Esters of the trihydric
alcohol glycerol and fatty
acids
Phosphorylated on sn-3
by glycerol kinase to give
glycerol 3-phosphate and
not glycerol 1-phosphate.
15. It contains groups in addition to an alcohol and afatty
acid.
a. Phospholipids: in addition to fatty acids,
phospholipid contains
◦ an alcohol,
◦ a phosphoric acid residue.
◦ May have nitrogen containing bases and other substituent
Ex: glycerophospholipids the alcohol is glycerol and in
sphingophospholipids the alcohol is sphingosine.
b. Glycolipids (glycosphingolipids): Lipids
containing a fatty acid, sphingosine, and
carbohydrate.
c. Other complex lipids: Lipids such as
sulfolipids and aminolipids. Ex: Lipoproteins
16.
17. Component of cell membrane – both structural
and regulatory functions.
Phospholipid in mitochindria – lecithin, cephalin
and cardiolipin – maintain ETC
Absorption of fat
Transport of lipids
Arachidonic acid – serves as a precursor of
various eicosanoids
Cephalin – Blood clotting
18. also called phosphoglycerides
membrane lipids in which two fatty acids are
attached in ester linkage to the first and second
carbons of glycerol
a highly polar or charged group is attached
through a phosphodiester linkage to the third
carbon
19. Glycerol is prochiral
◦ no asymmetric carbons
◦ But attachment of phosphate at one end converts it into a
chiral compound.
• Various important types of
glycerophopholipids
◦ Phosphatidic acid
◦ Lecithin
◦ Cephalin
◦ Phosphatidylinositol
◦ Phosphatidylserine
◦ Plasmalogens
◦ Cardiolipin
20. Also known as lecithins
Present in phospholipids of the cell membrane.
Choline (part of neurotransmittor) – component
of lecithin
Dipalmitoyl lecithin is a very effective surface
active agent - major constituent of the Surfactant
◦ Absence - premature infants causes respiratorydistress
syndrome
21. Precursor of Second Messengers
Phosphatidylinositol 4,5-bisphosphate -
constituent of cell membrane phospholipids.
upon stimulation by a suitable hormone
agonist
cleaved into diacylglycerol and inositol
trisphosphate
22. Found in large quantities in brain and nerve
tissue.
fatty acid, phosphoric acid, choline, and a
complex amino alcohol, sphingosine
No glycerol is present.
The combination of sphingosine plus fatty
acid is known as ceramide – found in
glycosphingolipids
23.
24.
25. widely distributed in every tissue of the
body,
particularly in nervous tissue such as brain
outer leaflet of the plasma membrane, where
they contribute to cell surface carbohydrates.
Ex: glycosphingolipid :ceramide and one or
more sugars.
◦ Galactosylceramide
◦ Gangliosides
26. Complexes of lipid with protein
Transport vehicle for lipids
Five types
◦ Chylomicron
◦ Very low density lipoprotein (VLDL)
◦ Low density lipoprotein (LDL)
◦ High Density lipoprotein (HDL)
◦ Free fatty acid complexes
27. These include fatty acids, glycerol, steroids,
other alcohols, fatty aldehydes, and ketone
bodies, hydrocarbons, lipid-soluble vitamins,
and hormones.
28. Compound containing cyclic
steroid nucleus
Phenanthrene nucleus – A,B,C
Cyclopentane ring – D
Several steroids in biological
systems
◦ Cholestrol
◦ Bile acids
◦ Vitamin D
◦ Sex Hormone
◦ Adrenocortical hormones
◦ Cardiac glycosides
◦ Alkaloids
29. Best known steroid
Association with
atherosclerosis.
Precursor of a large number
of equally important steroids
◦ bile acids,
◦ adrenocortical hormones,
◦ sex hormones,
◦ D vitamins - Ergosterol
◦ cardiac glycosides
30. Properties
◦ Yellowish crystalline solid
◦ Insoluble in water and soluble in organic solven
Function
◦ Present in nervous tissues – insulating cover
◦ Biochemical function – precursor for many
biochemical substances and component of cell
membrane
31. synthesized from cholesterol in the liver
It keep bile cholesterol in a soluble state as
micelles and promote the digestion of lipids
in the intestine.
Primary bile acids : Cholic acid and
chenodeoxycholic acid
Secondary bile acids : lithocholic acid and
deoxycholic acid.