Implantation and placentation , and overviewPranjal Gupta
Implantation and formation of placenta is an essential developmental process during human embryogenesis as it marks the connection between maternal and fetal blood, a condition specific to mammals more precisely eutherians. It works as a passage of required nutrients to the growing embryo and collection of its waste. It also discusses various types of placenta that are seen in mammals.
Implantation and placentation , and overviewPranjal Gupta
Implantation and formation of placenta is an essential developmental process during human embryogenesis as it marks the connection between maternal and fetal blood, a condition specific to mammals more precisely eutherians. It works as a passage of required nutrients to the growing embryo and collection of its waste. It also discusses various types of placenta that are seen in mammals.
Steps of fertilization, where transport of gametes(oocyte and spermatozoon) , illustrated with images.
Differences in characteristics of egg and sperm of fertilization are tabulated.
Capacitation and acrosomal reaction are shown with diagrams to understand.
Barriers protecting female gamete shown with images.
Flowchart has been drawn to show the phases of fertilization and response of egg after entry of the sperm with explanation.
The result of fertilization is highlighted .
Ends
The tiny fertilized egg sitting in the oviduct now has to
perform a heroic task. It must somehow communicate its
presence to the mother and convert the whole of her physiology
and anatomy from a cyclic reproductive state to a
pregnant one.
Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development. .The process of fertilization involves a sperm fusing with an ovum. The stages of fertilization can be divided into four processes: 1) sperm preparation, 2) sperm-egg recognition and binding, 3) sperm-egg fusion and 4) fusion of sperm and egg pronuclei and activation of the zygote.
In testis, the immature male germ cell (spermatogonia ) produce sperms by spermatogenesis
The spermatogonia ( sing. Spermatogonium ) present on the inside of seminiferous tubules multiply by mitotic division and increase in numbers
Each spermatogonium is diploid and contains 46 chromosomes
Some of the spermatogonia called primary spermatocytes periodically undergo meiosis.A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal, haploid cells called secondary spermatocyte, which have only 23 chromosomes
The secondary spermatocyte undergo the second meiotic division to produce four equal, haploid spermatids
presentation on oogenesis of fertilisation process full details about it u will never find it anywhere else have full details about the ovum formation polar bodies and everything . so explore here
1. Spermatogenesis (Spermatocytogenesis, Spermiogenesis, Spermiation, Shape and function of cells inside the Testis, Semen and sperm structure, Sperm journey after synthesis to outside)
Steps of fertilization, where transport of gametes(oocyte and spermatozoon) , illustrated with images.
Differences in characteristics of egg and sperm of fertilization are tabulated.
Capacitation and acrosomal reaction are shown with diagrams to understand.
Barriers protecting female gamete shown with images.
Flowchart has been drawn to show the phases of fertilization and response of egg after entry of the sperm with explanation.
The result of fertilization is highlighted .
Ends
The tiny fertilized egg sitting in the oviduct now has to
perform a heroic task. It must somehow communicate its
presence to the mother and convert the whole of her physiology
and anatomy from a cyclic reproductive state to a
pregnant one.
Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development. .The process of fertilization involves a sperm fusing with an ovum. The stages of fertilization can be divided into four processes: 1) sperm preparation, 2) sperm-egg recognition and binding, 3) sperm-egg fusion and 4) fusion of sperm and egg pronuclei and activation of the zygote.
In testis, the immature male germ cell (spermatogonia ) produce sperms by spermatogenesis
The spermatogonia ( sing. Spermatogonium ) present on the inside of seminiferous tubules multiply by mitotic division and increase in numbers
Each spermatogonium is diploid and contains 46 chromosomes
Some of the spermatogonia called primary spermatocytes periodically undergo meiosis.A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal, haploid cells called secondary spermatocyte, which have only 23 chromosomes
The secondary spermatocyte undergo the second meiotic division to produce four equal, haploid spermatids
presentation on oogenesis of fertilisation process full details about it u will never find it anywhere else have full details about the ovum formation polar bodies and everything . so explore here
1. Spermatogenesis (Spermatocytogenesis, Spermiogenesis, Spermiation, Shape and function of cells inside the Testis, Semen and sperm structure, Sperm journey after synthesis to outside)
Here provided contents for learning that what are the male and female gametes. How to they form? And described how to both gametes fused (fertilization)on the molecular basis.
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.
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.
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 .
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.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
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.
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/
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.
2. Fertilization is the fusion of haploid gametes,
egg and sperm, to form the diploid zygote.
fertilization process which occurs naturally
within the body or through reproductive
technologies outside the body, the overall
product in both cases is a diploid zygote
It also activates the egg, triggers the beginning
of embryonic development.
3.
4. Encounter of SPERMATOZOA and OVA.
CAPACITATIONand CONTACT.
ACROSOME reaction and PENETRATION.
FUSIONof the SPERM with EGG.
ACTIVATIONof OVUM.
5.
6. During the fertilization phase, millions of sperms
travel from vagina to the uterus and into the
fallopian tube.
CHEMOTAXIS – A chemical substance is found in
the cortex of egg.
In general interaction is through special devices or
particular forms of behavior.
The primary need is a fluid medium for the act of
fertilization and delivery of sperm to the egg.
2 types of FERTILIZATION.
7. EXTERNAL FERTILISATION.
• Occurs outside of the body of the female
• Increased number of eggs produced to insure the
survival of the species
Eg : Fish and Amphibians.
INTERNAL FERTILIZATION.
• Occurs inside the body of the female.
• Fewer number of egg are produced.
• Increased parental care insure species survival
Eg : mammals, reptiles, birds.
8. Several thousand sperms
reach the egg and
one will fertilize it.
When the sperm fuses
with the egg it initiates
a series of chemical
changes that prevent
anyother sperm from entering.
9. Sperm undergoes capaciation (further
maturation) within the female reproductive
tract
Occurs in the female’s vagina.
Vaginal secretions cause a molecular change
in the sperm plasma lemma (removal of
decapacitating factor – semen proteins ,
results in increased membrane fluidity).
Takes 4-5 hours in humans.
10.
11. When the acrosome reaction occurs, a number of
photolytic enzymes are exposed or released.
One or more of these enzymes is responsible for
digesting the hole through the zona pellucida
through which the sperm enters the perivitelline
space.
12.
13. The male nucleus enters the egg cytoplasm and becomes
the male pronucleus.
As a result of the sperm fusing with the egg plasma
lemma, the oocyte nucleus, which is at metaphase of the
second meiotic division, completes that division giving
rise to another polar body.
Following the second meiotic division, what is now the
nucleus of the ovum becomes the female pronucleus.
The haploid male and female pronuclei move toward one
another, meet, and fuse to form the diploid nucleus of the
zygote.
The zygote will now proceed to undergo cleavage.
14. A series of morphological, physiological and
molecular changes that occur in the egg in response
to fusion of the sperm with the egg.
15. As early as 12 hours after fertilization you can see the two
bundles of genetic material (two pronuclei), one from each
parent. By 18-20 hours after fertilization, these pronuclei
fuse, and what starts out as two cells becomes one (called a
zygote)