The document discusses the major mass extinction events that have occurred throughout Earth's history. It defines mass extinction as an event where a large portion of biodiversity is lost. It then describes the five largest mass extinction events by time period, effects on species, and potential causes. Currently, the document states that humans are causing a sixth mass extinction by overhunting species, spreading invasive species and disease, polluting the environment, and contributing to climate change.
The extinction of a large number of species within a relatively short period of geological time thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt
In this Presentation, I tried to give an overview of Five Mass Extinctions happened till now.
8.wild life and impacts of climate change on wildlifeMr.Allah Dad Khan
A series of Presentation ByMr Allah Dad Khan Special Consultant NRM , Former DG Agriculture Extension KPK Province , Visiting Professor the University of Agriculture Peshawar Pakistan allahdad52@gmail.com
28.wild l ife as affected by climate change A series of Presentation ByMr All...Mr.Allah Dad Khan
A series of Presentation ByMr Allah Dad Khan Special Consultant NRM , Former DG Agriculture Extension KPK Province , Visiting Professor the University of Agriculture Peshawar Pakistan allahdad52@gmail.com
Sixth Mass Extinction Are Alive Or Dead?.pptxSherdySalem
Are we dead or alive? Can we survive or no? Not or yes? Is the dnd near?
Are we going to die? Yes of course. Extinction is coming . Humans are dying. We need to be safe. We need to stop. We are pollutants
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.
The extinction of a large number of species within a relatively short period of geological time thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt
In this Presentation, I tried to give an overview of Five Mass Extinctions happened till now.
8.wild life and impacts of climate change on wildlifeMr.Allah Dad Khan
A series of Presentation ByMr Allah Dad Khan Special Consultant NRM , Former DG Agriculture Extension KPK Province , Visiting Professor the University of Agriculture Peshawar Pakistan allahdad52@gmail.com
28.wild l ife as affected by climate change A series of Presentation ByMr All...Mr.Allah Dad Khan
A series of Presentation ByMr Allah Dad Khan Special Consultant NRM , Former DG Agriculture Extension KPK Province , Visiting Professor the University of Agriculture Peshawar Pakistan allahdad52@gmail.com
Sixth Mass Extinction Are Alive Or Dead?.pptxSherdySalem
Are we dead or alive? Can we survive or no? Not or yes? Is the dnd near?
Are we going to die? Yes of course. Extinction is coming . Humans are dying. We need to be safe. We need to stop. We are pollutants
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.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
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.
(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.
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.
2. DEFINATION- An event in which a considerable
portion of the world’s biodiversity is lost.
Not only the evolution of life on Earth, but also about
the effects of extreme changes in our planet's
atmosphere, and how life finds ways to rebound.
Rate of extinction ∝
1
Rate of Speciation
4. The Ordovician
- Silurian
Extinction
This consists of two consecutive mass extinctions.
When combined together ,O-S is widely considered to
be the second most catastrophic event in history.
TIME PERIOD- About 450–440 million years ago.
EFFECTS- 60% to 70% of all species were vanquished.
This included 85% of marine species that died.
CAUSES- Massive glaciation and sea-level drop.
5. The Late
Devonian
Extinction
The Late Devonian Extinction was less severe than the
other mass extinctions
TIME PERIOD- It occurred 375–360 million years ago at
the end of the Devonian Period.
EFFECTS- At least 70% of all species went extinct. This
mass extinction lasted for over 20 million years.
CAUSES- Though opinions vary, the biggest evidence is
attributed to global anoxia. The oxygen shortage was
possibly triggered by global cooling or oceanic volcanism.
6. The Permian -
Triassic
Extinction
The Permian-Triassic Extinction was such a devastating
event that it had the nickname the “Great Dying” because
of its significance.
TIME PERIOD- The Permian-Triassic Extinction happened
252 million years ago.
EFFECTS- Earth’s largest extinction event in history killed
96% of all marine species and about 70% of land species. It
took 30 million years for vertebrates to fully recover. Highly
successful marine arthropod and trilobite also went extinct.
CAUSES- Severe volcanic activity, environmental change and
long-term methane release.
7. The Triassic -
Jurassic
Extinction
TIME PERIOD- Occurred 201.3 Million years ago.
EFFECTS- 70-75% of terrestrial and marine species go
extinct. Although the effects were less disastrous, but
most amphibians were eliminated. In the end of it,
dinosaurs were left with little terrestrial competition.
CAUSES- Volcanoes and giant flood basalts. From the
sudden release of carbon dioxide, climate change
amplified the greenhouse effect.
8. The
Cretaceous-
Tertiary
Extinction
TIME PERIOD- About 66 million years ago.
EFFECTS- 75% of species became extinct. Rates of
extinction broadly swept the land, sea and air. In the
oceans, ammonites disappeared. Known for killing
dinosaurs. Eventually, mammals emerged as
dominant large land animals.
CAUSES- An asteroid impact which left an impact
called the Chicxulub Crater, Volcanism, etc.
9. Sixth Mass
Extinction
We are at present in the middle of the sixth mass extinction,
and humans are the causative. They have already killed
most of the animal species for their own recreational
activities and benefits.
The invasive species were transported from one part of the
world to other part that eliminated the native species
resided in that part. Immigration and emigration of humans
and animals have spread several diseases in different parts
of the world where they were absent.
Biomagnification harmed marine life to a greater extent.
The natural available resources are depleting because of the
growing population. The heavy pollution led to an increase
in the temperatures and water levels in oceans that would
have several catastrophic effects in the coming future.
10.
11. CONCLUSION
In effect, a mass extinction cleans the slate, creating new evolutionary niches which
promote a wide range of species, increasing biodiversity, competition.
In some cases increasing complexity in organisms. We are an example of the aftermath of
mass extinctions.
The rate of change is important because animals can only adapt over long periods of time.
If a change happens too quickly, many animals will go extinct because they are not able to
adapt in time.
We are already seeing major groups of animals suffering, such as amphibians and coral
reefs, both of which rely on specific amounts of water and temperatures to survive.
