The moon formed approximately 95 million years after the formation of the solar system from a large collision that tore material away from the molten early Earth. It has a small core and rocky mantle made up of dense rocks rich in oxygen, silicon, magnesium, and iron. The moon has a very thin atmosphere and experiences large temperature variations between its day and night sides. The moon's gravity causes Earth's tides and is slowly increasing the length of an Earth day. Eclipses occur when the moon or Earth block the sun from the other's view. Unlike Earth, the moon does not have seasons due to its minimal axial tilt.
The program was Matt Cass, Physics program coordinator and instructor at Southwestern Community College, who spoke to the club today about the solar eclipse that will occur on August 21, 2017. Our area in WNC will have a total eclipse during this time for a few minutes.
The program was Matt Cass, Physics program coordinator and instructor at Southwestern Community College, who spoke to the club today about the solar eclipse that will occur on August 21, 2017. Our area in WNC will have a total eclipse during this time for a few minutes.
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 .
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.
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 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.
2. HOW DID THE MOON FORM?
HOW DID THE MOON FORM?
●It formed when a huge collision tore a chunk of the primitive molten Earth away,
sending the raw ingredients for the moon into orbit.
● The impact must have occurred about 95 million years after the formation of the
solar system
●New studies in 2015 gave further weight to this theory, based on simulations of
planetary orbits in the early solar system
3. WHAT IS THE MOON
MADE OF?
• Very small core, just 1% to 2% of the
moon's mass and roughly 420 miles (680
km) wide.
•Rocky mantle is about 825 miles (1,330
km) thick and made up of dense rocks rich
in iron and magnesium.
•The crust that includes the lunar surface
averages some 42 miles (70 km) deep.
COMPOSITION
43% oxygen, 20% silicon, 19% magnesium, 10%
iron, 3% calcium, 3% aluminum, 0.42%
chromium, 0.18% titanium and 0.12%
manganese
Traces of water
Hundreds of pits
4. DOES THE MOON HAVE
AN ATMOSPHERE?
• A very thin atmosphere.
• Temperatures vary wildly, daytime temperatures on the sunny
side of the moon reach 273 degrees F (134 Celsius); on the night
side it gets as cold as minus 243 F (minus 153 C).
•Average distance from Earth: 238,855 miles (384,400 km)
•Perigee (closest approach to Earth): 225,700 miles (363,300 km)
•Apogee (farthest distance from Earth): 252,000 miles (405,500
km)
•Orbit circumference: 1,499,618.58 miles (2,413,402 km)
•Mean orbit velocity: 2,287 mph (3,680.5 kph)
5. HOWDOES THE MOON'S ORBIT
EARTHAND CAUSE TIDES?
•The Moon's gravity pulls at the Earth, causing
predictable rises and falls in sea levels known as tides
• High tide occur on the side of the Earth nearest the
moon
•The pull of the moon is also slowing the Earth's
rotation, an effect known as tidal braking, which
increases the length of our day by 2.3 milliseconds
per century.
• Earth's gravity stretched the moon into its oddly
distorted shape early in its lifetime.
6. WHAT IS AN ECLIPSE?
• A lunar eclipse takes place
when Earth is directly
between the sun and the
moon, casting Earth's
shadow onto the moon
• A solar eclipse occurs when
the moon passes between
the sun and the Earth,
casting the moon's shadow
onto Earth.
• The last total solar eclipse
visible from the United
States happened in August
2017; the next one will take
place in April 2024.
7. DOES THE MOON HAVE SEASONS?
The Earth's axis of rotation is tilted about 23.5 degrees in relation to the
ecliptic plane, an imaginary disk through Earth's orbit around the sun. This
means the Northern and Southern hemispheres point somewhat toward or
away from the sun depending on the time of year, varying the amount of
solar radiation they receive and causing the seasons.
But the moon's axis is tilted by only about 1.5 degrees, so the moon doesn't
experience noticeable seasons. This means that some areas are always lit by
sunlight, and other places are perpetually draped in shadow.
