The significant break through in chemistry was made during last two centuries wherein we analysed the subject more minutely, even upto the level of the smallest creative and functional unit of substances i.e. atom, which is involved in all sorts of chemistry any how.
During this span of time atoms could be fragmented into still finer subatomic constituents and existence of nucleus was confirmed. Some of the legendry chemists could manage to peep inside the atom and gave every detail about the atomic world through their atomic models. Bohr gave the detail profile of orbiting electrons and successfully explained the line spectrum of hydrogen. With the unfolding of the structure of atom the chemical science passed from its infancy state i.e. crude, empirical and macroscopic state to scientific, rational, microscopic and mature state of understanding.
Infact, the outlook of every chemistry of a substance is a reflection of ingoing business of extra nuclear electrons. So the idea regarding arrangement of electrons around the nucleus is essential to understand the chemical behaviour on atomic level. This topic will be concluded with the explicit detail about electronic configuration to make the fascinating chemistry lucid and comprehensive.
This paper shows my findings for determining the grating constant of a diffraction grating, the wavelengths of each line of the spectrum of hydrogen, and experimentally calculating the Rydberg constant.
The significant break through in chemistry was made during last two centuries wherein we analysed the subject more minutely, even upto the level of the smallest creative and functional unit of substances i.e. atom, which is involved in all sorts of chemistry any how.
During this span of time atoms could be fragmented into still finer subatomic constituents and existence of nucleus was confirmed. Some of the legendry chemists could manage to peep inside the atom and gave every detail about the atomic world through their atomic models. Bohr gave the detail profile of orbiting electrons and successfully explained the line spectrum of hydrogen. With the unfolding of the structure of atom the chemical science passed from its infancy state i.e. crude, empirical and macroscopic state to scientific, rational, microscopic and mature state of understanding.
Infact, the outlook of every chemistry of a substance is a reflection of ingoing business of extra nuclear electrons. So the idea regarding arrangement of electrons around the nucleus is essential to understand the chemical behaviour on atomic level. This topic will be concluded with the explicit detail about electronic configuration to make the fascinating chemistry lucid and comprehensive.
This paper shows my findings for determining the grating constant of a diffraction grating, the wavelengths of each line of the spectrum of hydrogen, and experimentally calculating the Rydberg constant.
From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays
From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays
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.
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.
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.
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.
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.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
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.
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.
1. Exercises/problems of Chapter 38 and reduced solutions
38.1 The graph in the right shows the stopping potential as a
function of the frequency of the incident light falling on a metal
surface, (a) Find the photoelectric work function for this metal.
(b) What value of Planck's constant does the graph yield? (c)
Why does the graph not extend below the x-axis? (d) If a
different metal were used, what characteristics of the graph
would you expect to be the same and which ones ro be
different?
38.2 The human eye is most sensitive to green light of wavelength 505 urn. Experiments have found that
when people are kept in a dark room until their eyes adapt to the darkness, a single photon of green light
will trigger receptor cells in the rods of the retina. (a) What is the frequency of this photon? (b) How much
energy (in joules and electron volts) does it deliver to the receptor cells? (c) to appreciate what a sma1l
amount of energy this is, calculate how fast a typical bacterium of mass 9.5 X 10- 12 g would move if it
had that much energy?
38.5 An excited nucleus emits a gamma-ray photon with an energy of 2.45 MeV. (a) What is the phoron
frequency? (b) What is the photon wavelength? (c) How does the wavelength compare with a typical
nuclear diameter of 10-14
m?
38.11 (a) A proton is moving at a speed much slower than the speed of light. It has kinetic energy K1 and
momentum Pl. If the momentum of the proton is doubled, so P2 = 2P1 how is its new kinetic energy K2
related to K1? (b) A photon with energy E1 has momentum P1. If another photon has momentum P2 that is
twice P1 how is the energy E2 of the second photon related to E1?
38.15 Use Balmer's formula to calwlate (a) the wavelength, (b) the frequency, and (c) the photon energy
for the H line of the Balmer series for hydrogen.
38.22 (a) What is the angular momentum L of the electron in a Hydrogen atom, with respect to an origin
at the nucleus, when the atom is in its lowest energy level? (b) Repeat part (a) for the ground level of He+
.
Compare to the answer in part (a).
38.23 A hydrogen atom is in a state with energy -1.51 eV. In the Bohr model, what is the angular
momentum of the electron in the atom, with respect to an axis at the nucleus?
38.37 X rays with initial wavelength 0.0665 nm undergo Compton scattering. What is the longest
wavelength found in the scattered x rays? At which scattering angle is this wavelength observed?
38.39 If a photon of wavelength 0.04250 nm strikes a free electron and is scattered at an angle of 35.0°
from its original direction, find (a) the change in the wavelength of this photon; (b) the wavelength of the
scattered light; (c) the change in energy of the photon (is it a loss or a gain?); (d) the energy gained by the
electron.
38.40 A photon scatters in the backward direction ( = 180°) from a free proton that is initially at rest.
What must the wavelength of the incident photon be if it is to undergo a 10.0% change in wavelength as a
result of the scattering?
38.56 A 2.50 W beam of light of wavelength 124 nm falls on a metal surface. You observe that the
maximum kinetic energy of the ejected electrons is 4.16 eV. Assume that each photon in the beam ejects a
photoelectron. (a) What is the work function (in electron volts) of this metal? (b) How many
photoelectrons are ejected each second from this metal? (c) If the power of the light beam, but not its
wavelength, were reduced by half, what would be the answer to part (b)? (d) If the wavelength of the
beam, but not its power, were reduced by half, what would be the answer to part (b)?
2. 38.59 The negative muon has a charge equal to that of an electron but a mass that is 207 times as great.
Consider a hydrogen1ike atom consisting of a proton and a muon. (a) What is the reduced mass of the
atom? (b) What is the ground-level energy (in electron volts)? (c) What is the wavelength of the radiation
emitted in the transition mm the n = 2 level to the n = 1 level?
38.60 An incident x-ray photon is scattered from a free electron that is initially at rest. The photon is
scattered straight back at an angle of 180' mm its initial direction. The wavelength of the scattered photon
is 0.0830 nm. (a) What is the wavelength of the incident photon? (b) What is the magnitode of the
momentum of the electron after the collision? (c) What is the kinetic energy of the electron after the
collision?
38.63 (a) What is the smallest amount of energy in electron volts that must be given to a hydrogen atom
initially in its ground level so that it can emit the If" line in the Balmer series? (b) How many different
possibilities of spectral-line emissions are there for this atom when the electron starts in the n = 3 level
and eventually ends up in the ground level? Calculate the wavelength of the emitted photon in each case.
38.67 The red giant Betelgeuse has a surface temperature of 3000 K and is 600 times the diameter of our
sun. (If our sun were that large, we would be inside it!) Assume that it radiates like an ideal blackbody. (a)
If Betelgeuse were to radiate all of its energy at the peak-intensity wavelength, how many photons per
second would it radiate? (b) Find the ratio of the power radiated by Betelgeuse to the power radiated by
our sun (at 5800K).
38.73 Nuclear fusion reactions at the center of the sun produce gamma-ray photons with energies of order
1 MeV (106
eV). By contrast, what we see emanating from the sun's surface are visible light photons with
wavelengths of order 500 nm. A simple model that explains this difference in wavelength is that a photon
undergoes Compton scattering many times-in fact, about 1626
times, as suggested by models of the solar
interior, as it travels from the center of the sun to its surface. (a) Estimate the increase in wavelength of a
photon in an average Compton scattering event. (b) Find the angle in degrees through which the photon is
scattered in the scattering event described in part (a). (Hint: A useful approximation is cos = 1 - 2
,
which is valid for << 1. Note that is in radians in this expression). (c) It is estimated that a photon
takes about 106
years to travel from the core to the surface of the sun. Find the average distance that light
can travel within the interior of the sun without being scattered (This distance is roughly equivalent to
how far you could see if you were inside the sun and could survive the extreme temperatures there. As
your answer shows, the interior of the sun is very opaque).