The document discusses three theories of ancient land bridges that were proposed to explain similarities between species on different continents:
1) The Atlantic Land Bridge between Africa and South America was thought to explain shared species like monkeys and ostriches, but zoological evidence shows the species are unrelated and the land bridge is unlikely.
2) Lemuria was proposed to explain lemurs in Madagascar and lorises in India, but lemurs and lorises are unrelated and fossil evidence shows their ancestors lived elsewhere.
3) The Antarctica Land Bridge between Australia and South America was suggested for marsupials and frogs, but there is no fossil or living evidence of these species in intervening areas, so this land
Ecades and ecotype - Ecades •introduction •Definition •Explanation •types of ecades , Ecotype, • introduction, •Definition ,•Ecotype VS. species ,•How did ecotype appear ,•From ecotype to species, •Example
The naming of taxonomic groups of plants is determined by nomenclatural types.This PPT explores the basic principles of ICBN with species emphasis on the nomenclatural types used in plant taxonomy intended for UG & PG students of Botany.
To determine the variation and the limitation between species, many concepts have been proposed.
When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa.
Plant kingdom as other living kingdoms has a hierarchy structure ends mostly with species rank.
Species are one of the basic units to compare in almost all fields of biology.
A species is defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction.
Definition of a species as a group of interbreeding individuals cannot be easily applied to organisms that reproduce only or mainly asexually.
If two lineages of oak look quite different, but occasionally form hybrids with each other, should we count them as different species?
Idea of a species is something that we humans invented for our own convenience.
‘‘No matter what variations occur in the individuals or the species, if they spring from the seed of one and the same plant, they are accidental variations and not such as distinguish a species permanently; one species never springs from the seed of another nor vice versa” - JOHN RAY.
Used a sexual system ‘‘natural system” for defining species - LINNAEUS.
‘‘A species is a collection of all the individuals which resemble each other more than they resemble anything else, which can by natural fecundation produce fertile individuals, and which reproduce themselves by generation, in such a manner that we may from analogy suppose them all to have sprung from one single individual” - DE CANDOLLE.
Ecades and ecotype - Ecades •introduction •Definition •Explanation •types of ecades , Ecotype, • introduction, •Definition ,•Ecotype VS. species ,•How did ecotype appear ,•From ecotype to species, •Example
The naming of taxonomic groups of plants is determined by nomenclatural types.This PPT explores the basic principles of ICBN with species emphasis on the nomenclatural types used in plant taxonomy intended for UG & PG students of Botany.
To determine the variation and the limitation between species, many concepts have been proposed.
When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa.
Plant kingdom as other living kingdoms has a hierarchy structure ends mostly with species rank.
Species are one of the basic units to compare in almost all fields of biology.
A species is defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction.
Definition of a species as a group of interbreeding individuals cannot be easily applied to organisms that reproduce only or mainly asexually.
If two lineages of oak look quite different, but occasionally form hybrids with each other, should we count them as different species?
Idea of a species is something that we humans invented for our own convenience.
‘‘No matter what variations occur in the individuals or the species, if they spring from the seed of one and the same plant, they are accidental variations and not such as distinguish a species permanently; one species never springs from the seed of another nor vice versa” - JOHN RAY.
Used a sexual system ‘‘natural system” for defining species - LINNAEUS.
‘‘A species is a collection of all the individuals which resemble each other more than they resemble anything else, which can by natural fecundation produce fertile individuals, and which reproduce themselves by generation, in such a manner that we may from analogy suppose them all to have sprung from one single individual” - DE CANDOLLE.
Phytogeography is concerned with all aspects of plant distribution, from the controls on the distribution of individual species ranges to the factors that govern the composition of entire communities and floras.
This pdf contains information about the various methods of documentation in plant taxonomy. It includes, floras, manuals, monographs, dictionaries, glosaries, indexes, icones, etc.
CONTINENTAL DRIFT THEORY AND DISCONTINUOUS DISTRIBUTION.pptxrimshaijaz6
theory of continental drift
The theory of continental drift was proposed by German scientist Alfred Wegener in the early 20th century. The theory suggests that the continents were once part of a supercontinent called Pangea, which broke apart and drifted to their current locations. The Earth's crust is split up into seven large plates and a few smaller ones, all of which can slowly move around on the Earth’s surface.
discontinuous distribution a distribution in which populations of related organisms are found in widely separated parts of the world, e.g. lung flukes in Australia, Africa and South America. Such a distribution is thought to indicate the great age of the group, with intermediate populations having become extinct.
Phytogeography is concerned with all aspects of plant distribution, from the controls on the distribution of individual species ranges to the factors that govern the composition of entire communities and floras.
This pdf contains information about the various methods of documentation in plant taxonomy. It includes, floras, manuals, monographs, dictionaries, glosaries, indexes, icones, etc.
CONTINENTAL DRIFT THEORY AND DISCONTINUOUS DISTRIBUTION.pptxrimshaijaz6
theory of continental drift
The theory of continental drift was proposed by German scientist Alfred Wegener in the early 20th century. The theory suggests that the continents were once part of a supercontinent called Pangea, which broke apart and drifted to their current locations. The Earth's crust is split up into seven large plates and a few smaller ones, all of which can slowly move around on the Earth’s surface.
discontinuous distribution a distribution in which populations of related organisms are found in widely separated parts of the world, e.g. lung flukes in Australia, Africa and South America. Such a distribution is thought to indicate the great age of the group, with intermediate populations having become extinct.
Palaeogeography or paleogeography is the study of historical geography, generally physical landscapes (visible features of an area of land). This is a brief overview of four famous paleogeographic theories: the permanence of continents, land bridges, continental drift, and plate tectonics.
9 Beautiful and Rare Species Found Only in AustraliaThe Aussie Way
The climate and huge terrain of Australia are as distinctive as the animals that inhabit it. And despite Australia’s abundance of lethal and dangerous creatures, you shouldn’t worry about them because everything has been done to ensure that everyone is safe.
Climate change and the effects of land clearing, which are tragically affecting life in Australia.
You can help maintain the natural ecosystem not just in Australia but all over the world by identifying tiny methods to reduce climate change and global warming.
Visit: https://theaussieway.com.au/9-beautiful-and-rare-species-found-only-in-australia/
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.
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.
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 .
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
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.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
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.
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.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
2. “This theory demands the presence of bridges of continental
size spreading under deep water, serving as means of
communication from one continent to the other”
2
These land bridges were present in Cenozoic era leaving behind no trace of
their existence.
They were supposed to have sunk beneath the oceans leaving no trace of
their existence.
They are restricted to regions where the seas were shallow.
3. Land bridges
Atlantic Land Bridge
Africa and South
America
Lemuria Land Bridge
Madagascar and India
Antarctica Land Bridge
Australia and South
America
4. Between Africa and South
America
Atlantic Land
Bridge
4 Monkeys
Porcupines
Ostriches
Pipid toads Side-necked turtles
Lungfishes
6. 6
Hypothesis rejected
Zoological evidence indicates that such land bridge is
unlikely to have existed.
In South America Edentates is endemic order of
mammals which includes armadillos, sloths and this
order is not present in Africa.
Monkeys, porcupines and ostriches of Africa and South
America are no longer closely related to each other and
belong to different families.
Hypothesis rejected
7. Between Madagascar and
India
Lemuria Land
Bridge
It was named 'Lemuria' because it was designed to explain the distribution
of lemurs.
Lemurs
•These are arboreal, nocturnal primates. The
representatives of lemurs are present in the oriental
Madagascar.
Lorises
•Lorises are lemur like animals present in the oriental
and Indian regions.
10. The lemurs were thought to have evolved on Lemuria
towards the end of Mesozoic and spread to Africa and
the Oriental region where they are represented today
by Lorises.
The original lemurs were left on Madagascar and
Comoro Island when rest of the Lemuria sank below
the sea in the Cenozoic period.
11. 11
Hypothesis rejected
Hypothesis rejected
Hypothesis rejected
Firstly, the recent studies have shown that although both lemurs and
lorises have evolved from the same early primate stock, they are
otherwise not related to each other.
Secondly, a number of fossils of this early primate stock or the so
called ancestors of lemurs and lorises have been found in Palacocene
and Eocene rocks in north (i.e. in Europe and North America).
Many zoologists suggest that Madagascar has been separated from the
rest of the world during the Cenozoic era due to some drastic climatic
and environmental conditions
So Lemuria land bridge is unlikely to have existed
14. 14
Hypothesis ejected
Hypothesis rejected
Hypothesis rejected
Flightless birds of S. America (Rhea) and the Emus Australia are not
closely related to one another and are classified in separate as such their
distribution need not be discussed in this context.
Lungfishes and side-necked turtles were widespread in all continents
during Cretaceous period and their discontinuous distribution is therefore
better accounted for by the extinction in the north of formerly worldwide
groups.
As for marsupials and the hybrid tree frogs are concerned, it may be
interesting to note that there are no fossil records nor living marsupials
and tree frogs in the Oriental region.
