1) The document discusses Newton's laws of motion and provides explanations and formulas for tension in a string when two bodies of unequal mass are connected by a string passing over a pulley.
2) It also discusses concepts like momentum, the law of conservation of momentum, different types of friction, advantages and disadvantages of friction, and methods to reduce friction.
3) Formulas are provided for calculating acceleration, tension, momentum, static and kinetic friction.
A simple ppt yet interactive on the topic work power and energy. With smooth design and looks the ppt is very good for clearing the basics related to this topic, hope it will help you further.
A simple ppt yet interactive on the topic work power and energy. With smooth design and looks the ppt is very good for clearing the basics related to this topic, hope it will help you further.
the relation between force and motion id described in Newtons three laws of motion. These laws are very simple statements and enable us to describe the future (or past) motion of body if we know the forces acting on it.
the relation between force and motion id described in Newtons three laws of motion. These laws are very simple statements and enable us to describe the future (or past) motion of body if we know the forces acting on it.
With this mantra success is sure to come your way. At APEX INSTITUTE we strive our best to realize the Alchemist's dream of turning 'base metal' into 'gold'.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
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 .
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
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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.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
(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.
5. Newton's Laws of Motion
1st Law
Law of Inertia
2nd Law
F = ma
3rd Law
F12 = -F21
6. 1st Law: “A body will remain at rest, or moving at
constant velocity, unless it is acted by an unbalanced
force.”
2nd Law:F = ma.
3rd Law: “For every action there is always an equal and
opposite reaction”
If two bodies exert a force on one another, the forces
are equal in magnitude, but opposite in direction.
F12 = -F21
Newton’s Laws of Motion
15. TENSION IN A STRING
CASE I
a
a
MOTION OF BODIES CONNECTED BY A STRING
When the bodies move vertically
Consider two bodies of unequal masses m1 and
m2 connected by the ends of a string, which
passes over a frictionless pulley as shown in the
diagram.
Net force on Body B: Two forces are acting on B
(i) Weight of A = W₂ = m₂g acting downward
(ii) Tension in string= T acting upward
So, net force F₂ = m₂ a = T - m₂ g (b/c T > W₂)….(ii)
16. CASE I
a
a
• Acceleration: Adding eq. (i) and (ii),
• m₁a + m₂a = m₁g - T + T - m₂g
• m₁a + m₂a = m₁g - m₂g OR
• m₁a + m₂a = (m₁ - m₂) g
• Therefore, a = (m₁ - m₂) g / (m₁ + m₂)
• Tension: Dividing eq. (i) and (ii),
• m₁a / m₂a = (m₁g – T) / (T - m₂g)
• m₁ / m₂ = (m₁g – T) / (T - m₂g)
• By cross multiplying,
• m₁ (T - m₂g) = m₂ (m₁g – T) OR
• m₁T - m₁ m₂ g = m₁ m₂ g - m₂T
• m₁T + m₂T = m₁ m₂ g + m₁ m₂ g
• ( m₁ + m₂)T = 2m₁ m₂ g
• T =2m₁m₂g / (m₁+ m₂)
17. TENSION IN A STRING
CASE 2:
a
a
When one of the bodies moves vertically while the other moves horizontally
Two bodies A & B of masses m1 and m2 are attached to the ends of a string, which passes over
a frictionless pulley as shown in the figure. The body "A" moves vertically downward with
an acceleration equal to "a" and the body "B" moves on a smooth horizontal plane towards the
pulley with the same acceleration.
Situation: Body A= m₁ and Body B= m₂
where m₁ > m₂
Required Data: Acceleration in the string a= ?
Tension in the string T= ?
Net force on Body A: Two forces are acting on A
(i) Weight of A = W₁ = m₁g acting downward
(ii) Tension in string= T acting upward
So, net force F₁ = m₁a = m₁g- T (b/c W₁ > T)………(i)
Net force on Body B:
There are three forces acting on it.
(i) Tension (T) in the string, which acts horizontally
(ii) Weight W2 = m2g acting vertically downward.
(iii) Reaction of the surface (R) on the body which
acts vertically upward. As there is no motion of body "B" in the vertical direction.
Therefore weight and normal reaction cancel each other
18. Thus the net horizontal force acting upon body B is T
T = m2a --------(ii)
Acceleration:
Putting the value of T in equation (i), we get
m1g – m2a = m1a
m1g = m1a + m2a
m1g = a (m1 + m2)
a = m1g / (m1 + m2)
Tension :
Putting the value of "a" in equation (ii), we get
T = m2a --------(ii)
OR T = m2m1g / (m1 + m2)
19. MOMENTUM
Physical quantity that describes the quantity of motion in a body is called
momentum.The momentum of a moving body is defined as
“The product of mass and velocity of a moving body is called linear momentum“
Formula: P = mV
Unit: N.s or kgm/s
20. LAW OF CONSERVATION OF
MOMENTUM
The law of conservation of momentum states that:
"When some bodies constituting an isolated system act upon
one another, the total momentum of the system remains constant."
"Total momentum of an isolated system before and
after collision is constant."
OR
21. FRICTION
“Friction is the force resisting the relative motion of
solid surfaces”
Types of Friction:
1. Static Friction: Static friction is friction between two or
more solid objects that are not moving relative to each
other.
2. Kinetic Friction: Kinetic friction, also known as dynamic
friction or sliding friction, occurs when two objects are
moving relative to each other and rub together (like a sled
on the ground).
Formula: F = µ R = µ W = µ mg
Unit: N
22. ADVANTAGES AND DISADVANTAGES OF
FRICTION
1. The main disadvantage of friction is that it produces heat
in various parts of machines. In this way some useful
energy is wasted as heat energy.
2. 2. Due to friction we have to exert more power in
machines.
3. Friction helps in stopping a vehicle on applying the brakes.
4. It helps in generating heat when we rub our hands together.
5. Asteroids burn in the atmosphere before reaching the earth
due to friction and saves lives on earth.
23. METHODS OF REDUCING FRICTION
1)Friction can be reduced by making the surface
smooth by polishing.
2)Friction can be reduced by applying lubricants
(like oil or grease) to the rubbing surface.
3)Friction can be reduced by using wheels to move
objects.
4)Friction can be reduced by using ball bearing
between the moving parts of machine.