ICML2016: Low-rank tensor completion: a Riemannian manifold preconditioning a...Hiroyuki KASAI
The presentation in ICML2016 at New York, USA on June 20, 2016.
We propose a novel Riemannian manifold preconditioning approach for the tensor completion problem with rank constraint. A novel Riemannian metric or inner product is proposed that exploits the least-squares structure of the cost function and takes into account the structured symmetry that exists in Tucker decomposition. The specific metric allows to use the versatile framework of Riemannian optimization on quotient manifolds to develop preconditioned nonlinear conjugate gradient and stochastic gradient descent algorithms for batch and online setups, respectively. Concrete matrix representations of various optimization-related ingredients are listed. Numerical comparisons suggest that our proposed algorithms robustly outperform state-of-the-art algorithms across different synthetic and real-world datasets.
ICML2016: Low-rank tensor completion: a Riemannian manifold preconditioning a...Hiroyuki KASAI
The presentation in ICML2016 at New York, USA on June 20, 2016.
We propose a novel Riemannian manifold preconditioning approach for the tensor completion problem with rank constraint. A novel Riemannian metric or inner product is proposed that exploits the least-squares structure of the cost function and takes into account the structured symmetry that exists in Tucker decomposition. The specific metric allows to use the versatile framework of Riemannian optimization on quotient manifolds to develop preconditioned nonlinear conjugate gradient and stochastic gradient descent algorithms for batch and online setups, respectively. Concrete matrix representations of various optimization-related ingredients are listed. Numerical comparisons suggest that our proposed algorithms robustly outperform state-of-the-art algorithms across different synthetic and real-world datasets.
Application of definite integrals,we will explore some of the many application of definite integral by using it to calculate areas between two curves, volumes, length of curves, and several other application.
Karl Pearson's Correlation, Pearson's Correlation, Pearson's Coefficient, Statistics, Economics, Social Work, Methods of Correlation, Examples, Questions, Direct Method, Indirect Method, Short-cut Method, Types of Correlation, Degree of Correlation Coefficient, Definition of Correlation
ARIMA models provide another approach to time series forecasting. Exponential smoothing and ARIMA models are the two most widely-used approaches to time series forecasting, and provide complementary approaches to the problem. While exponential smoothing models were based on a description of trend and seasonality in the data, ARIMA models aim to describe the autocorrelations in the data.
How to write Powerfully - Effective Scientific and Business WritingAtif Azad
"If you do not write well, you do not think well; if you do not think well, others will do your thinking for you."
This is a comprehensive guide on writing clearly and powerfully for scientific and business audiences. Main features are below:
- put the topic in the subject;
- put the action in the verb;
- avoid clusters of nouns;
- write short sentences;
- use clear pronouns;
- use parallel ideas in parallel forms;
- compare correctly;
- and avoid common writing flaws.
The presentation contains a number of links to bite sized video lectures to further explain the presented concepts.
Sodium metabolism and its clinical applicationsrohini sane
A comprehensive presentation on Sodium Metabolism and its clinical significance for MBBS, BDS, B Pharm & Biotechnology students to facilitate self- study.
Application of definite integrals,we will explore some of the many application of definite integral by using it to calculate areas between two curves, volumes, length of curves, and several other application.
Karl Pearson's Correlation, Pearson's Correlation, Pearson's Coefficient, Statistics, Economics, Social Work, Methods of Correlation, Examples, Questions, Direct Method, Indirect Method, Short-cut Method, Types of Correlation, Degree of Correlation Coefficient, Definition of Correlation
ARIMA models provide another approach to time series forecasting. Exponential smoothing and ARIMA models are the two most widely-used approaches to time series forecasting, and provide complementary approaches to the problem. While exponential smoothing models were based on a description of trend and seasonality in the data, ARIMA models aim to describe the autocorrelations in the data.
How to write Powerfully - Effective Scientific and Business WritingAtif Azad
"If you do not write well, you do not think well; if you do not think well, others will do your thinking for you."
This is a comprehensive guide on writing clearly and powerfully for scientific and business audiences. Main features are below:
- put the topic in the subject;
- put the action in the verb;
- avoid clusters of nouns;
- write short sentences;
- use clear pronouns;
- use parallel ideas in parallel forms;
- compare correctly;
- and avoid common writing flaws.
The presentation contains a number of links to bite sized video lectures to further explain the presented concepts.
Sodium metabolism and its clinical applicationsrohini sane
A comprehensive presentation on Sodium Metabolism and its clinical significance for MBBS, BDS, B Pharm & Biotechnology students to facilitate self- study.
An explanation found in introductory texts proposes that osmosis is a diffusion process in which water diffuses from a higher to a lower water concentration. This explanation is not theoretically sound and does not match the experimental data. This workshop explores common misconceptions about osmosis and the osmosis explanations given by physicists.
Download the PowerPoint slideshow from SlideShare. The notes sections contain explanations and references.
Professor Mridul M. Panditrao, deals with this basic, complicated but very important topic for not only post- graduates but also for under-graduates. Various complicated issues have been discussed in detail, mainly from clinical point of view.
DIURETICS
Diuertics are the drugs used to increase the urine output by excretion of Na+ and water from the kidney.
Primary effect: Reduce absorption of sodium and chlorine ions from the filtrate.
Secondary effect: Increased water loss along with the excretion of sodium and chlorine.
CLASSIFICATION
Based on mechanism of action and site of action
Acting on PCT
a. Carbonic anhydrase inhibitor
Acetazolamide
Dorazolamide
Metazolamide
b. Xanthine derivative
Aminophylline
Theophylline
2. Act on loop of Henlee
a. Osmotic Diuretic
Mannitol
Glycerin
Urea
b. Loop diuretic/ High ceiling
Furosemide
Torsemide
Ethacrynic acid
3. Drug acting on DCT
a. Thaizide diuretic
Chlorthiazide
Hydrochlorthiazide
Hydroflumethazide
Bendroflumethazide
Benzthiazide
Cyclopenthiazide
b. Thiazide like diuretic
Chlorthalidone
Indapamide
Metolazine
4. Drugs acting on collecting duct
a. Aldosterone antagonist
Spironolactone
b. Directly acting
Amiloride
Triamterine
Major application of diuretics ;
Used in congestive heart failure
Essential hypertension
Acute and chronic heart failure
Currently used screening methods are based on effect of drug on water and electrolyte metabolism in rats.
SCREENING METHODS
IN VIVO METHODS :
Diuretic activity in rats [LIPSCHITZ TEST]
Saluretic and diuretic activity in dogs
Saluretic activity in rats
Clearance methods
Stop flow technique
Micro puncture technique in rat.
IN VITRO METHODS :
Carbonic anhydrase inhibition in vitro
Patch clamp technique in kidney cells
Isolated perfused kidney
Perfusion of isolated kidney tubules
1. CARBONIC ANHYDRASE INHIBITION IN-VITRO
PURPOSE AND RATIONALE
Carbonic anhydrase is a Zn containing enzyme.
H2CO3 H20+CO2
Inhibition of CARBONIC anhydrase in PCT causes
● Decreased H+ ion formation
● Decreased Na+/H+ antiport
●Increased Na+and HCO3- in lumen
●increased excretion of Na+HCO3-
●Increased production of alkaline urine
PROCEDURE
The analytical method is based on the catalysis of the conversion of CO2 to H2CO3 by the enzyme , with resulting decrease in pH being monitored colorimetrically.
ASSAY
■ CO2 flow rate is adjusted to 30 to 45 ml/min
■ 400 µl phenol red indicator solution
■ 100µ l enzyme.
■ 200 µl H2O or appropriate drug concentration after 3min of equilibriation.
■ 100 µl carbonate/bicarbonate buffer is added.
■ The following parameters are determined in duplicate samples :
Tu = [uncatalysed time]=time for the colour change to occur in the absence of enzyme.
Te =[Catalysed time]=time for the colour change to occur in presence of enzyme.
Tu – Te = enzyme rate
Ti = enzyme rate in the presence of various concentrations of inhibitor.
EVALUATION
Percentage inhibition of carbonic anhydrase is evaluated
% evaluation =1
Water Analysis through High Performance Liquid Chromotography, Ion Exchange R...Jonathan Damora
The purpose of this paper is to analyze the dissolved ion concentrations of the anions; chloride, sulfate, and nitrate within a natural water sample using High Performance Liquid Chromatography, a specific application of Ion-Exchange Chromatography, as well as explain the mechanisms behind Ion Exchange Chromatography.
August 7, 2012 2103 c02 Sheet number 30 Page number 60 cyan b.docxrock73
August 7, 2012 21:03 c02 Sheet number 30 Page number 60 cyan black
60 Chapter 2. First Order Differential Equations
Solving Eq. (31) for v0, we find the initial velocity required to lift the body to the altitude ξ,
namely,
v0 =
√
2gR
ξ
R + ξ . (32)
The escape velocity ve is then found by letting ξ → ∞. Consequently,
ve =
√
2gR. (33)
The numerical value of ve is approximately 6.9 mi/s, or 11.1 km/s.
The preceding calculation of the escape velocity neglects the effect of air resistance, so the
actual escape velocity (including the effect of air resistance) is somewhat higher. On the other
hand, the effective escape velocity can be significantly reduced if the body is transported a
considerable distance above sea level before being launched. Both gravitational and frictional
forces are thereby reduced;air resistance, in particular,diminishes quite rapidly with increasing
altitude. You should keep in mind also that it may well be impractical to impart too large an
initial velocity instantaneously; space vehicles, for instance, receive their initial acceleration
during a period of a few minutes.
PROBLEMS 1. Consider a tank used in certain hydrodynamic experiments. After one experiment the
tank contains 200 L of a dye solution with a concentration of 1 g/L. To prepare for
the next experiment, the tank is to be rinsed with fresh water flowing in at a rate of
2 L/min, the well-stirred solution flowing out at the same rate. Find the time that will
elapse before the concentration of dye in the tank reaches 1% of its original value.
2. A tank initially contains 120 L of pure water. A mixture containing a concentration of
γ g/L of salt enters the tank at a rate of 2 L/min, and the well-stirred mixture leaves the
tank at the same rate. Find an expression in terms of γ for the amount of salt in the tank
at any time t. Also find the limiting amount of salt in the tank as t → ∞.
3. A tank originally contains 100 gal of fresh water. Then water containing 12 lb of salt per
gallon is poured into the tank at a rate of 2 gal/min, and the mixture is allowed to leave at
the same rate. After 10 min the process is stopped, and fresh water is poured into the tank
at a rate of 2 gal/min, with the mixture again leaving at the same rate. Find the amount of
salt in the tank at the end of an additional 10 min.
4. A tank with a capacity of 500 gal originally contains 200 gal of water with 100 lb of salt
in solution. Water containing 1 lb of salt per gallon is entering at a rate of 3 gal/min, and
the mixture is allowed to flow out of the tank at a rate of 2 gal/min. Find the amount
of salt in the tank at any time prior to the instant when the solution begins to overflow.
Find the concentration (in pounds per gallon) of salt in the tank when it is on the point
of overflowing. Compare this concentration with the theoretical limiting concentration if
the tank had infinite capacity.
5. A tank contains 100 gal of water and 50 oz of salt. Water containing a salt con ...
Pada Transformasi Laplace bag. kedua, sifat-sifat transformasi laplace yang lebih mendalam dan khusus akan dipelajari. Sifat-sifat ini akan banyak digunakan dalam penerapan metode transformasi laplade dalam menyelesaikan masalah nilai awal dengan persamaan diferensial yang yang berkaitan dengan fungsi-fungsi tangga (piecewise function)
Transformasi Laplace adalah transformasi yang sering digunakan untuk menyelesaikan masalah syarat awal. Metode penyelesaian persamaan diferensial biasa menggunakan transformasi laplace terbukti cukup ampuh digunakan untuk menyelesaikan berbagai masalah nilai awal.
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 .
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.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
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.
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.
1. Tuesday, 6th February 2018
MATA KULIAH:
PEMODELAN MATEMATIKA
COMPARTMENTAL
MODEL
Lecture:
Heni Widayani, M.Si
2. Compartmental Diagram
Process
input output
Rate in Rate out
Balance Law
𝑛𝑒𝑡 𝑟𝑎𝑡𝑒
𝑜𝑓 𝑐ℎ𝑎𝑛𝑔𝑒
𝑜𝑓 𝑎 𝑠𝑢𝑏𝑠𝑡𝑎𝑛𝑐𝑒
=
𝑟𝑎𝑡𝑒
𝑖𝑛
−
𝑟𝑎𝑡𝑒
𝑜𝑢𝑡
Example :
1. The decay process of radioactive elements
2. Births and deaths in population
3. Pollution into and our of a lake or river, or the atmosphere
4. Drug asimilation into and removal from the bloodstream
3. Exponential decay and radiometric dating
Essential to the understanding of our history
(find the approximately date)
RADIOACTIVE
MATERIAL
Emitted particles
Asumption :
1. The amount of an element present is large enough so that we are
justified in ignoring random fluctuations.
2. The process is continuous in time
3. There is a fixed rate of decay for an element
4. There is no increase in mass of the body of material.
𝑟𝑎𝑡𝑒 𝑜𝑓 𝑐ℎ𝑎𝑛𝑔𝑒 𝑜𝑓
𝑟𝑎𝑑𝑖𝑜𝑎𝑐𝑡𝑖𝑣𝑒 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙
𝑎𝑡 𝑡𝑖𝑚𝑒 𝑡
= −
𝑟𝑎𝑡𝑒 𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓
𝑟𝑎𝑑𝑖𝑜𝑎𝑐𝑡𝑖𝑣𝑒
𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙
𝑑𝑒𝑐𝑎𝑦𝑒𝑑
4. Formulating the differential equation
Let N(𝑡) be the mass (in gram) of radioactive atoms at time 𝑡 and let ∆𝑡
be a small change in time. The change number of atom is proportional
to the number of atom at the start of the time period.
𝑁 𝑡 + ∆𝑡 = 𝑁 𝑡 − 𝑘𝑁 𝑡 ∆𝑡, 𝑁 𝑡0 = 𝑁0
where 𝑘 is a positive constant of proportionality indicating the rate of
decay per atom in unit time (decay constant).
If ∆𝑡 is small enough (∆𝑡 → 0), then
𝑑𝑁
𝑑𝑡
= −𝑘𝑁, 𝑁 𝑡0 = 𝑁0
Initial value
Problem (IVP)
Use the separation variable technique to solve the equation !
𝑵 𝒕 = 𝑵 𝟎 𝒆−𝒌(𝒕−𝒕 𝟎)
Since 𝑡 − 𝑡0 > 0 then
lim
𝑡→∞
𝑁0 𝑒−𝑘(𝑡−𝑡0) = 0
𝑁(𝑡) is a monoton
decreasing function
5. Substance 𝑯𝒂𝒍𝒇 − 𝒍𝒊𝒇𝒆(𝝉)
Xenon-133 5 days
Barium-140 13 days
Lead-210 22 years
Strontium-90 25 years
Carbon-14 5568 years
Plutonium 23103 years
Uranium-235 0.707x109 years
Uranium-238 4.5 x 109 years
Experimentally measured for the half-life (𝝉)
Half-Life (𝜏) is defined as the time taken for
half of a given quantity of atoms to decay. If
𝑁 𝑡0 = 𝑁0 then
𝑁 𝜏 =
𝑁0
2
Find the value of decay constant (𝒌)
for Carbon-14 !
In General,
𝑘 =
ln 2
𝜏
6. Residence time is defined to be the mean time that an individual
particle is in the compartment.
𝑑𝑁
𝑑𝑡
= −𝑘 𝑁
𝑘−1 is the residence time for a single compartment where 𝑘 is the
constant rate of 𝑁.
𝑵 𝒕 = 𝑵 𝟎 𝒆−𝒌(𝒕−𝒕 𝟎)
The fraction of particles remaining in the compartment at time 𝑡 is
given by 𝑒−𝑘(𝑡−𝑡0).
The quantity 𝐹 𝑡 = 1 − 𝑒−𝑘𝑡
represents the probability an
individual particle has left the compartment by time 𝑡 (cumulative
probability function for the time each particle was in the
compartment)
𝑭 𝒕 = 𝑷𝒓 𝑻 < 𝒕
𝑇 is the random variable representing the time for each period.
Residence time
7. Study Case :Lascaux Cave Paintings
In the Cave of Lascaux in France there are some ancient wall paintings,
believed to be prehistoric. Using a Geiger counter, the current decay rate of C14
in charcoal fragments collected from the cave was measured as approximately
1.69 disintegrations per minutes per gram of carbon. In comparison,for living
tissue in 1950 the measurement was 13.5 disintegration per minute per gram
of carbon. How long ago was the radioactive carbon formed (the Lascaux Cave
painting painted)?
ANSWER :
Let 𝑁(𝑡) be the amout of C14 per gram in the charcoal at time 𝑡. We know that
𝜏 = 5568 years (the half-life of C14), so we get
𝑘 ≈ 0.0001245 per year
Let 𝑡0 = 0 be the current time. Let 𝑇 be the time that the charcoal was formed,
and thus 𝑇 < 0. For 𝑇 < 𝑡 < 𝑡0, the C14 decays follow the function
𝑁 𝑡 = 𝑁0 𝑒−𝑘𝑇
We don’t have the 𝑁(𝑇) or 𝑁0, but we have 𝑁′
𝑇 =
𝑁′(𝑇)
𝑁′(0)
=
𝑁(𝑇)
𝑁0
Thus, we get
𝑇 = −
1
𝑘
ln
𝑁 𝑇
𝑁0
= −16690 years ago
8. Salt dissolved in a tank
tank
salt inflow salt outflow
𝑟𝑎𝑡𝑒 𝑐ℎ𝑎𝑛𝑔𝑒
𝑜𝑓 𝑠𝑎𝑙𝑡 𝑚𝑎𝑠𝑠
𝑖𝑛 𝑡𝑎𝑛𝑘
=
𝑟𝑎𝑡𝑒
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑠𝑎𝑙𝑡
𝑒𝑛𝑡𝑒𝑟𝑠 𝑡𝑎𝑛𝑘
−
𝑟𝑎𝑡𝑒
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑠𝑎𝑙𝑡
𝑙𝑒𝑎𝑣𝑒𝑠 𝑡𝑎𝑛𝑘
𝑑𝑆
𝑑𝑡
= 10𝑐𝑖𝑛 𝑡 −
1
10
𝑆(𝑡), 𝑆 0 = 𝑠0
Balance law
A large tank contains 100 litres of salt water. Initially 𝑠0 kg of salt is
dissolved. Salt water flows into the tank at the rate of 10 litres per
minute, with the concentration 𝑐𝑖𝑛(𝑡) (kg of salt/litre) of this incoming
water-salt mixture varies with time. We assume that the solution in the
tank is thoroughly mixed and that the salt solution flows out at the
same rate at which it flows in: that is, the volume of water-salt mixture
in the tank remain constant.
Use the technique of integrating factors to solve IVP equation above!
𝑆 𝑇 = 𝑠0 𝑒−𝑇/10
+ 10𝑒−𝑇/10
0
𝑇
𝑐𝑖𝑛(𝑠)𝑒 𝑠/10
𝑑𝑡
9. Lake Pollution Models
Mass of
pollutant in
lake
Mass inflow Mass outflow
Polluted river water, pollution
dump into the lake
Water flows from the lake
carrying some polution with it
𝑟𝑎𝑡𝑒 𝑜𝑓 𝑐ℎ𝑎𝑛𝑔𝑒
𝑝𝑜𝑙𝑙𝑢𝑡𝑎𝑛𝑡 𝑚𝑎𝑠𝑠
𝑖𝑛 𝑙𝑎𝑘𝑒
=
𝑟𝑎𝑡𝑒
𝑜𝑓 𝑝𝑜𝑙𝑙𝑢𝑡𝑎𝑛𝑡
𝑒𝑛𝑡𝑒𝑟𝑠 𝑙𝑎𝑘𝑒
−
𝑟𝑎𝑡𝑒
𝑜𝑓 𝑝𝑜𝑙𝑙𝑢𝑡𝑎𝑛𝑡
𝑙𝑒𝑎𝑣𝑒𝑠 𝑙𝑎𝑘𝑒
Assumption :
1. The lake has a constant volume 𝑉
2. The lake water is continuously well mixed so the pollution is uniform
throughout
Let 𝑀(𝑡) is the mass of the pollutant in the lake
Let 𝐶(𝑡) be the concentration of the pollutant in the lake at time 𝑡.
Let 𝐹 be the rate at which water flows out of the lake in m3/day.
Let 𝑐𝑖𝑛 is the concentration g/m3) of the pollutant in the flow entering lake
𝑑𝑀
𝑑𝑡
= 𝐹𝑐𝑖𝑛 − 𝐹
𝑀 𝑡
𝑉
𝑑𝐶
𝑑𝑡
=
𝐹
𝑉
𝑐𝑖𝑛 −
𝐹
𝑉
𝐶, 𝐶 0 = 𝐶0
10. Problem :
How long it will take for the lake’s pollution level to reach 5% of
its initial level, if only fresh water flows into the lake ?
Implement the result for the cases below
a. Consider Lake Eric with 𝑉 = 458 × 109
m3 and 𝐹 = 480 ×
106 m3/day = 1,75 x 1011 m3/year.
b. Consider Lake Ontario with 𝑉=1636 x 109 m3 and 𝐹 = 572 ×
106
m3/day = 2,089 x 1011 m3/year.
a. t0.05 = 7.8 years
b. t0.05 = 23.5 years
Although the flow rate in and out of Lake Ontario is similar to
Lake Erie, it takes significantly longer to clear the pollution from
Lake Ontario due to the larger volume water in Lake Ontario.
11. Drug Assimilation into the blood
The drug dissolves in the gastrointestinal tract (GI-tract) and each
ingredient is diffused into bloodstream.
Drug carried to the locations in which they act and are removed from
the blood by the kidneys and the liver.
GI Tract Blood
Drug intake digestion tissues
𝑟𝑎𝑡𝑒 𝑐ℎ𝑎𝑛𝑔𝑒
𝑜𝑓 𝑑𝑟𝑢𝑔
𝑖𝑛 𝐺𝐼 𝑡𝑟𝑎𝑐𝑡
=
𝑟𝑎𝑡𝑒 𝑜𝑓
𝑑𝑟𝑢𝑔
𝑖𝑛𝑡𝑎𝑘𝑒
-
𝑟𝑎𝑡𝑒 𝑜𝑓
𝑑𝑟𝑢𝑔 𝑙𝑒𝑎𝑣𝑒𝑠
𝐺𝐼 𝑡𝑟𝑎𝑐𝑡
𝑟𝑎𝑡𝑒 𝑐ℎ𝑎𝑛𝑔𝑒
𝑜𝑓 𝑑𝑟𝑢𝑔
𝑖𝑛 𝑏𝑙𝑜𝑜𝑑
=
𝑟𝑎𝑡𝑒 𝑜𝑓
𝑑𝑟𝑢𝑔
𝑒𝑛𝑡𝑒𝑟𝑠 𝑏𝑙𝑜𝑜𝑑
-
𝑟𝑎𝑡𝑒 𝑜𝑓
𝑑𝑟𝑢𝑔
𝑙𝑒𝑎𝑣𝑒𝑠 𝑏𝑙𝑜𝑜𝑑
Let 𝑥(𝑡) be the amount of a drug in the GI-tract at time 𝑡.
Let 𝑦(𝑡) be the amount of a drug in the bloodstream at time 𝑡.
12. A single cold pill
There is no ingestion of the drug except that which occurs initially.
Assumption :
1. The output rate of GI-tract is proportional to the drug concentration,
which is proportional to the amount of drug in the bloodstream
2. In the bloodstream, the initial amount of the drugs is zero. The level
increases as the drug diffuses from the GI-tract an decreases as the
kidneys and liver remove it.
𝑑𝑥
𝑑𝑡
= −𝑘1 𝑥, 𝑥 0 = 𝑥0
𝑑𝑦
𝑑𝑡
= 𝑘1 𝑥 − 𝑘2 𝑦, 𝑦 0 = 0
where 𝑥0 is the amount of a drug in the pill, 𝑘1 and 𝑘2 are positive
contant of proportionality.
The cold pill is made up of a decongestant and an antihistamine, which
are define the value of 𝑘1 and 𝑘2.
Decongestant Antihistamine
𝑘1 1.3860/hr 0.6931/hr
𝑘2 0.1386/hr 0.0231/hr
𝑥 𝑡 = 𝑥0 𝑒−𝑘1 𝑡
𝑦 𝑡 =
𝑘1
𝑘1 − 𝑘2
𝑒−𝑘2 𝑡 − 𝑒−𝑘1 𝑡
13. A course of cold pills
We take a course of pills rather than just one.
There is a continuous flow of drugs into the GI-tract
𝑑𝑥
𝑑𝑡
= 𝐼 − 𝑘1 𝑥, 𝑥 0 = 𝑥0
𝑑𝑦
𝑑𝑡
= 𝑘1 𝑥 − 𝑘2 𝑦, 𝑦 0 = 0
where 𝐼 is a positive constant represnting the rate of ingestion of the
drug (g/hr).
The analytic solution was
𝑥 𝑡 =
𝐼
𝑘1
1 − 𝑒−𝑘1 𝑡
𝑦 𝑡 =
𝐼
𝑘2
1 −
1
𝑘2 − 𝑘1
𝑘2 𝑒−𝑘1 𝑡
− 𝑘1 𝑒−𝑘2 𝑡
* This solution is valid only if 𝑘1 ≠ 𝑘2.
14. Dull, dizzy, or dead?
Australian law prohibits driving of vehicles (including boats and
horse) for those with BAL (blood alcohol level) above 0.05. This the
relates to 50mg/100ml alcohol in the bloodstream.
This restriction is a result of U.S statistics which indicate that a person
with a BAL of 0.15 is 25 times more likely to have a fatal accident than
one with no alcohol. Furthermore, for 41% of Australian men
excessive alcohol leads to confrontational behaviour.
BAL Behavioural effect
5% Lowered alertness, usually good feeling, release of
inhibitors, impaired judgement
Dull and dignified
10% Slowed reaction times and impaired motor function,
less caution
Dangerous and devilish
15% Large consistent increases in reaction time Dizzy
20% Marked depression in sensory and motor capability,
decidedly intoxicated
Disturbing
25% Severe motor disturbance, staggering, sensory
perceptions greatly impaired, smashed
Disgusting and
dishevelled
30% Stuporous but conscious, no comprehension of what’s
going on
Delirious and
disoriented
35% Surgical anaesthesia, minimal level causing death Dead drunk
40% 50 times the minimal level, causing death Dead !
15. • The alcohol intake into the GI-tract is “controlled” by the drinker. The
amount of alcohol subsequently absorbed into the bloodstream
depends on the concentration of alcohol, other liquid and food in the
GI-tract, as well as on the weight and sex of the individual. Alcohol is
removed from the bloodstream at a constant rate by the liver. This is
independent of the body weight, sexm of the individual and
concentration of alcohol in the bloodstream and assumes that the liver
has not been damaged by large doses of alcohol. (Ignoring that a small
percentage leaves through sweat, saliva, breath, and urine. This means
BAL estimate may be slightly above the true value).
• Let 𝐶1(𝑡) be the concentration of alcohol in the GI-tract at time 𝑡.
Let 𝐶2(𝑡) be the concentration of alcohol in the bloodstream at time 𝑡
𝑑𝐶1
𝑑𝑡
= 𝐼 − 𝑘1 𝐶2
𝑑𝐶2
𝑑𝑡
= 𝑘2 𝐶1 −
𝑘3 𝐶3
𝐶2 + 𝑀
• In the case of drinking on an empty stomach, 𝑘1 = 𝑘2
• If drinking occurs together with a meal (or is diluted) then 𝑘1 > 𝑘2