This document provides an introduction to prisms, including their basic structure and types. It discusses the different types of prisms such as regular, irregular, right, oblique and parallelepipeds. It also outlines some common uses of prisms for internal reflection and describes the main parts of a prism as the apex and base. Finally, it provides a brief explanation of how prisms work by refracting light as it passes from one medium to another due to changes in light speed.
These lectures has prepared for postgraduate student (Ophthalmology) according to the curriculum of Bangladesh College of Physician and Surgeons (BCPS) and Bangabondhu Sheikh Mujib Medical University (BSMMU) Bangladesh
Ophthalmic Prisms: Prismatic Effects and DecentrationRabindraAdhikary
Ophthalmic Prisms: Prismatic Effects and Decentration
here we discuss about the ophthalmic prisms, the prismatic effects as caused by the decentration( moving the optical center away from the visual axis)
These lectures has prepared for postgraduate student (Ophthalmology) according to the curriculum of Bangladesh College of Physician and Surgeons (BCPS) and Bangabondhu Sheikh Mujib Medical University (BSMMU) Bangladesh
Ophthalmic Prisms: Prismatic Effects and DecentrationRabindraAdhikary
Ophthalmic Prisms: Prismatic Effects and Decentration
here we discuss about the ophthalmic prisms, the prismatic effects as caused by the decentration( moving the optical center away from the visual axis)
This presentation is mainly focused on progressive addition lenses along with the brief description of single vision reading lenses ,bifocal and trifocals which are the other options available for the management of presbyopia. It also include a short description on the fitting of the PAL. PAL is the most used option worldwide for the management of presbyopia .PAL is also used in the management of progressive myopia and the studies shows it is more effective than the bifocal lenses. PAL are more effective in myopia management when the myopia comes along with the near esophoria and accommodation lag. In this modern century personalised progressive lenses are the most effective in matching the need of the patients.
Astigmatic lens used in ophthalmology and eyeRACHANA KAFLE
different types and classifications of astigmatic lens used
availability of astigmatic lens
uses of astigmatic lens
advantages and disadvantages of astigmatic lens
Optics of Contact lenses by Ankit Varshney. If you understand optics properly you can prescribe contact lenses scientifically. Comparison between spectacles and contact lenses.
This presentation is mainly focused on progressive addition lenses along with the brief description of single vision reading lenses ,bifocal and trifocals which are the other options available for the management of presbyopia. It also include a short description on the fitting of the PAL. PAL is the most used option worldwide for the management of presbyopia .PAL is also used in the management of progressive myopia and the studies shows it is more effective than the bifocal lenses. PAL are more effective in myopia management when the myopia comes along with the near esophoria and accommodation lag. In this modern century personalised progressive lenses are the most effective in matching the need of the patients.
Astigmatic lens used in ophthalmology and eyeRACHANA KAFLE
different types and classifications of astigmatic lens used
availability of astigmatic lens
uses of astigmatic lens
advantages and disadvantages of astigmatic lens
Optics of Contact lenses by Ankit Varshney. If you understand optics properly you can prescribe contact lenses scientifically. Comparison between spectacles and contact lenses.
I have 1.8 Years of experience in devising IT solutions for improved business efficiency and bespoke client-facing services. A great communicator who takes great pride in finding the right solution for difficult problems.
An optical prism is a transparent optical element with flat, polished surfaces that refract light. At least one surface must be angled—elements with two parallel surfaces are not prisms. The traditional geometrical shape of an optical prism is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type. Some types of optical prism are not in fact in the shape of geometric prisms. Prisms can be made from any material that is transparent to the wavelengths for which they are designed. Typical materials include glass, plastic, and fluorite.
It an interesting ppt from with a child can understand the concept of solid shape and different views of a solid shapes from different sides .
thank you
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 .
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.
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.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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.
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.
3. INTRODUCTION
• A prism (from Greek) is a structure whose outer surfaces are triangular and converge to a
single point at the top, making the shape roughly a pyramid in the geometric sense. The base
of a pyramid can be trilateral, quadrilateral, or any polygon shape, meaning that a pyramid
has at least three outer triangular surfaces (at least four faces including the base). The square
pyramid, with square base and four triangular outer surfaces is a common version.
4. TYPES OF PRISM
• Regular Prisms
The bases of the regular prisms are regular polygons.
• Irregular Prisms
The bases of the irregular prisms are irregular polygons.
• Right Prisms
The lateral faces of the right prisms are rectangles or squares.
• Oblique Prisms
The lateral faces of the oblique prisms are rhomboids or rhombi.
5. • Parallelepipeds
The bases of parallelepiped prisms are parallelograms.
• Cuboid
The faces of cuboids are rectangular faces.
• Triangular Prism
The bases are triangles.
• Quadrangular Prism
The bases are quadrilaterals.
• Pentagonal Prism
The bases are pentagons.
• Hexagonal Prism
The bases are hexagon.
6. USES OF PRISM
• Prisms are sometimes used for the internal reflection at the surfaces rather than for
dispersion. If light inside the prism hits one of the surfaces at a sufficiently steep angle, total
internal reflection occurs and all of the light is reflected.
7. PARTS OF
PRISM
• Prism, Mainly consist of two parts
Apex and Base. These are the only
two parts which have perfect angle.
8. HOW DO PRISM
WORKS?• Light changes speed as it moves from one medium to another (for example, from air into the glass of the
prism). This speed change causes the light to be refracted and to enter the new medium at a different angle .
The degree of bending of the light's path depends on the angle that the incident beam of light makes with
the surface, and on the ratio between the refractive indices of the two media . The refractive index of many
materials (such as glass) varies with the wavelength. This causes Rainbow.