The role of ultrafast processes in human vision
This minireview discusses the process of vision which begins with the absorption of a photon of light by rhodopsin in rod cells. Rhodopsin consists of the protein opsin bound to the light-sensitive molecule retinal. Upon photon absorption, the retinal undergoes an ultrafast cis-trans isomerization within 200 femtoseconds, initiating a chain of reactions that converts rhodopsin to various intermediates and ultimately triggers an electrical signal to the brain. This initial isomerization is one of the fastest biological reactions known and occurs with high efficiency due to the protein environment of rhodopsin. Advances in ultrafast spectroscopy have provided insights into the mechanisms and
a substance can absorb any visible light or external radiation and then again emit it. this called fluorescence and the process of reduction in fluorescence intensity is called quenching. this presentation is all about quenching of fluorescence.
Fluorescence spectroscopy is based on the principle of fluorescence emission that occurs when a molecule absorbs light and is excited to a higher electronic state. The excited molecule then relaxes to the ground state via vibrational relaxation and emission of a photon. The emitted light has a longer wavelength than the absorbed light due to energy losses in vibrational relaxation, following Stokes' rule. Fluorescence spectroscopy can provide information about molecular structure and interactions through analysis of fluorescence emission spectra.
The document provides an overview of fluorescence, including:
- Definitions of key fluorescence concepts like excitation, emission spectra, and quantum yield
- How molecular structure influences fluorescence properties
- Common fluorescent probes and their applications in tagging molecules and sensing analytes
- Techniques for detection and measurement of fluorescence, including microscopy and filtering of excitation and emission wavelengths
- Factors that influence fluorescence intensity and limit sensitivity, such as photobleaching
This document discusses fluorescence spectroscopy. It begins by defining fluorescence as the emission of light by a substance when an electron returns to the ground state from an excited state. Factors that affect fluorescence include temperature, viscosity, oxygen concentration, pH, and molecular structure. Applications of fluorescence in pharmacy include determining inorganic substances, in nuclear research, as fluorescent indicators, in organic analysis, in liquid chromatography, and for determining vitamins B1 and B2. Instrumentation for fluorescence spectroscopy includes various light sources, filters, sample cells, and detectors such as photomultiplier tubes.
This document discusses factors that affect fluorescence intensity. It explains that fluorescence intensity is directly proportional to the rigidity of a structure and inversely proportional to temperature. Other factors that can decrease fluorescence intensity include oxygen, which can oxidize fluorescent substances, as well as electron withdrawing substituent groups. Fluorescence intensity is directly proportional to concentration at low concentrations but does not obey linearity at high concentrations. The presence of other non-fluorescent solutes can also impact intensity through inner filter effects. In conclusion, several physicochemical factors influence fluorescence intensity measurements.
1. Fluorescence is the emission of light from a substance that has absorbed light or other electromagnetic radiation. It occurs in certain biological molecules like fireflies, corals, and genetically engineered fish.
2. Fluorescence results from electrons absorbing energy and getting excited to higher energy molecular orbitals, then dropping down and emitting photons of lower energy. The Jablonski diagram illustrates this process.
3. Many factors influence fluorescence, including molecular structure, temperature, solvent, pH, and structural rigidity. Fluorescent dyes like FITC and cyanine dyes are used in applications like labeling and fluorescence resonance energy transfer.
Fluorescent dyes are molecules that absorb light at one wavelength and emit it at a longer wavelength. They are useful for labeling and studying biomolecules. Some common fluorescent dyes include fluorescein, rhodamine, and GFP. Fluorescent dyes have many applications, such as cancer research where they allow over 1500 protein spots to be detected from microdissected tissue, physiological sensing inside deep tissue, monitoring acidified organelles during autophagy, and assessing contamination during drilling operations. The Jablonski diagram illustrates the excited states involved in the fluorescent process.
a substance can absorb any visible light or external radiation and then again emit it. this called fluorescence and the process of reduction in fluorescence intensity is called quenching. this presentation is all about quenching of fluorescence.
Fluorescence spectroscopy is based on the principle of fluorescence emission that occurs when a molecule absorbs light and is excited to a higher electronic state. The excited molecule then relaxes to the ground state via vibrational relaxation and emission of a photon. The emitted light has a longer wavelength than the absorbed light due to energy losses in vibrational relaxation, following Stokes' rule. Fluorescence spectroscopy can provide information about molecular structure and interactions through analysis of fluorescence emission spectra.
The document provides an overview of fluorescence, including:
- Definitions of key fluorescence concepts like excitation, emission spectra, and quantum yield
- How molecular structure influences fluorescence properties
- Common fluorescent probes and their applications in tagging molecules and sensing analytes
- Techniques for detection and measurement of fluorescence, including microscopy and filtering of excitation and emission wavelengths
- Factors that influence fluorescence intensity and limit sensitivity, such as photobleaching
This document discusses fluorescence spectroscopy. It begins by defining fluorescence as the emission of light by a substance when an electron returns to the ground state from an excited state. Factors that affect fluorescence include temperature, viscosity, oxygen concentration, pH, and molecular structure. Applications of fluorescence in pharmacy include determining inorganic substances, in nuclear research, as fluorescent indicators, in organic analysis, in liquid chromatography, and for determining vitamins B1 and B2. Instrumentation for fluorescence spectroscopy includes various light sources, filters, sample cells, and detectors such as photomultiplier tubes.
This document discusses factors that affect fluorescence intensity. It explains that fluorescence intensity is directly proportional to the rigidity of a structure and inversely proportional to temperature. Other factors that can decrease fluorescence intensity include oxygen, which can oxidize fluorescent substances, as well as electron withdrawing substituent groups. Fluorescence intensity is directly proportional to concentration at low concentrations but does not obey linearity at high concentrations. The presence of other non-fluorescent solutes can also impact intensity through inner filter effects. In conclusion, several physicochemical factors influence fluorescence intensity measurements.
1. Fluorescence is the emission of light from a substance that has absorbed light or other electromagnetic radiation. It occurs in certain biological molecules like fireflies, corals, and genetically engineered fish.
2. Fluorescence results from electrons absorbing energy and getting excited to higher energy molecular orbitals, then dropping down and emitting photons of lower energy. The Jablonski diagram illustrates this process.
3. Many factors influence fluorescence, including molecular structure, temperature, solvent, pH, and structural rigidity. Fluorescent dyes like FITC and cyanine dyes are used in applications like labeling and fluorescence resonance energy transfer.
Fluorescent dyes are molecules that absorb light at one wavelength and emit it at a longer wavelength. They are useful for labeling and studying biomolecules. Some common fluorescent dyes include fluorescein, rhodamine, and GFP. Fluorescent dyes have many applications, such as cancer research where they allow over 1500 protein spots to be detected from microdissected tissue, physiological sensing inside deep tissue, monitoring acidified organelles during autophagy, and assessing contamination during drilling operations. The Jablonski diagram illustrates the excited states involved in the fluorescent process.
This document provides an overview of fluorometry, including basic concepts, instrumentation, and applications. It discusses how fluorescence occurs when a molecule absorbs light at one wavelength and reemits light at a longer wavelength. Factors that affect fluorescence such as temperature, pH, and dissolved oxygen are also covered. The relationship between fluorescence intensity and concentration is explained. Additionally, the document defines fluorescence polarization and describes various types of quenching including self-quenching, chemical quenching, and collisional quenching.
This document discusses key concepts in photosynthesis including absorption spectra of chlorophyll, action spectra, energy transfer during photosynthesis via resonance transfer to antenna complexes located in chloroplasts or plasma membranes, the z-scheme of electron transfer between four protein complexes in the thylakoid membrane, carbon reactions, differences in C3 and C4 plant leaf anatomy, and the C4 carbon fixation cycle.
intoduction to lumiscence
introduction and principle of chemilumiscence
different types of lumiscence
detail of the electrochemilumiscence, working, principle, instrumentation, measurin.
application in medical field
difference between chemilumiscence and elecrochemiluminescence
This document contains lecture notes for a Physical Chemistry VIII course taught by Dr. Fateh Eltaboni at the University of Benghazi. The notes cover topics in photochemistry including characteristics of light, absorption of light, the Beer-Lambert law, photochemical reactions versus thermochemical reactions, quantum yield, and calculations related to photochemistry. Dr. Eltaboni provides examples and illustrations to explain key concepts in photochemistry.
1. Photochemistry involves using light as a chemical reagent to promote molecules to electronically excited states or as a chemical product when excited states return to the ground state.
2. Fluorescence occurs when a molecule in an excited singlet state returns to the ground state and emits light. It is a spin-allowed process that results in emission at a longer wavelength than the absorbed light.
3. The excitation and fluorescence emission spectra of a compound are often approximately mirror images of each other, though there are exceptions when the excited and ground states differ in geometry.
The document discusses how solvents and chromophores affect UV-visible spectroscopy. It states that the solvent exerts influence on the absorption spectrum, with the same drug showing different absorption maxima in different solvents. Common solvents used are water, methanol, ethanol, ether, and cyclohexane. The solvent should not absorb in the region studied and have minimum interaction with solute. Chromophores like conjugated systems, carbonyls, and metal complexes determine absorption. Factors like conjugation, auxochromes, and solvent polarity can shift absorption maxima.
In molecular spectroscopy, a Jablonski diagram is a diagram that illustrates the electronic states of a molecule and the transitions between them. The states are arranged vertically by energy and grouped horizontally by spin multiplicity.
This document discusses factors that affect fluorimetry and quenching. It lists several factors that can influence fluorescence, including the nature of molecules, substituents, concentration, adsorption, light, oxygen, pH, temperature, and viscosity. It also describes different types of quenching such as self-quenching, chemical quenching, static quenching, and collisional quenching. Chemical quenching can occur due to changes in pH, presence of oxygen, or heavy metals. Static quenching involves complex formation between the fluorophore and quencher. Collisional quenching occurs through interactions between an excited fluorophore and quencher molecule.
1. Fluorescence anisotropy measures the polarization of emitted light from fluorophores and can be used to study molecular interactions and rotational motions.
2. When fluorophores are excited with polarized light, their subsequent emission is depolarized by rotational diffusion. Larger molecules rotate more slowly, preserving more polarization.
3. Fluorescence anisotropy can be used to measure binding constants and kinetics by detecting changes in rotational diffusion upon molecular interactions like antibody-antigen binding. This provides information about molecular size, shape, and microenvironment.
This document discusses factors that affect fluorescence and phosphorescence. It defines fluorescence and phosphorescence as types of molecular luminescence that are excited by photon absorption. The main difference is that fluorescence involves no change in electron spin, while phosphorescence does involve a change. Several factors can influence emission, including molecular structure and rigidity, temperature, solvent properties, pH, dissolved oxygen, concentration, and the presence of heavy atoms. More rigid and planar structures favor fluorescence and phosphorescence. Higher temperatures, viscosities, and oxygen levels decrease emission, while appropriate solvent polarity and pH can increase it.
This document discusses luminescence spectroscopy techniques such as fluorescence and phosphorescence. It explains that molecules absorb energy which is then emitted at a higher wavelength, and that emission is proportional to concentration. It also describes the energy level diagram and competing processes that occur after absorption, such as internal conversion, intersystem crossing, vibrational relaxation, and fluorescence or phosphorescence emission. Factors that affect fluorescence such as conjugation, substituents, and structural rigidity are also summarized.
Photoluminescent properties of fullerene derivativeszenziyan
The document discusses photoluminescence properties of fullerene derivatives. It explains that fullerenes and their derivatives show strong absorption around 3.7 eV but weak luminescence at room temperature due to a forbidden electronic transition. However, their photoluminescence increases at low temperatures due to reduced thermal quenching. The document also describes how fullerenes can act as energy transfer acceptors or donors in composite materials, and provides examples of photoluminescent fullerene-doped polymers and inorganic materials.
This document discusses chemiluminescence reactions that emit light. It defines chemiluminescence as a light-emitting chemical reaction and distinguishes it from other types of luminescence. Examples of gas-phase and liquid-phase chemiluminescent reactions are provided, such as the reaction of nitric oxide with ozone that produces excited nitrogen dioxide and emits light. The document also explores the chemiluminescent reaction involved in glowsticks and the firefly luciferase reaction.
Ultraviolet and visible spectroscopy is a technique that uses light in the UV-visible spectral region. It can be used to analyze organic molecules and determine their structure. Key concepts covered include electronic transitions, the Beer-Lambert law, and how solvents and conjugation affect UV-Vis spectra. UV-Vis spectroscopy can distinguish between isomers and functional groups, quantify substances, and identify unknown compounds.
This document summarizes key concepts in plasma chemistry from Chapter 2 of the reference book, including:
1) Elementary plasma reactions are determined by micro-kinetic characteristics like cross-sections and reaction probabilities, as well as kinetic distribution functions.
2) Collisions can be elastic, inelastic, or superelastic depending on whether the total kinetic energy and internal energies change during the collision.
3) Ionization processes include direct electron impact ionization, stepwise ionization, ion-molecule collisions, photoionization, and surface ionization.
4) The Thomson formula describes direct electron impact ionization cross-sections at high energies, while the Frank-Condon principle applies to ionization
This document discusses instrumentation methods of fluorimetry. It describes the key components of a fluorimeter including light sources like mercury vapor lamps and xenon arc lamps, filters and monochromators to select wavelengths of light, sample cells to hold liquid samples, and detectors like photomultiplier tubes and photovoltaic cells. Common types of fluorimeters are single beam, double beam, and spectrofluorimeters. Applications include determination of inorganic substances, proteins, and drugs.
Chemiluminescence is the production of light from a chemical reaction. Two chemicals react to form an excited intermediate state that releases energy in the form of photons as it returns to a stable ground state. This light emission occurs without much heat release. Chemiluminescent reactions can be grouped into chemical reactions using synthetic compounds, bioluminescent reactions from living organisms like fireflies, and electrochemiluminescent reactions involving electrical current. Forensic scientists use the chemiluminescent reaction of luminol to detect traces of blood at crime scenes by spraying a mixture that causes a blue glow in the presence of iron from hemoglobin.
Fluorescence(Forster) Resonance Energy Transfersavvysahana
This document discusses using fluorescence resonance energy transfer (FRET) to study the assembly and rearrangements of SNARE proteins during exocytosis at neural synapses. It describes two schemes using FRET to label specific SNARE proteins with donor and acceptor fluorophores. Scheme 1 uses Cerulean and Citrine labels on VAMP and SNAP-25 to detect resting SNARE complexes and their dispersion after vesicle fusion. Scheme 2 uses Cerulean on Syntaxin and Citrine on VAMP to monitor the trans-cis conformational change in SNAREs. The study finds FRET signals indicating the dynamic rearrangement of pre-assembled SNARE complexes during different stages of the SNARE cycle.
Flurimetry type of flurescence & quenchingsimisheeja
This document discusses types of fluorescence and quenching. There are three main types of fluorescence based on the excitation source: chemiluminescence, electrochemiluminescence, and photoluminescence. Quenching decreases fluorescence intensity and occurs via four main mechanisms: self-quenching, chemical quenching, static quenching, and collisional quenching. Factors like concentration, pH, presence of oxygen, halides, heavy metals, and temperature can also influence fluorescence by inducing quenching effects.
El documento resume el proceso de admisión de alumnos en el IES Marqués de Lozoya para el curso 2011-2012, incluyendo las fechas clave para la reserva de plaza, cambio de centro y matrícula. También describe los recursos del instituto como la sección bilingüe de inglés, las nuevas tecnologías, los laboratorios y la biblioteca. Finalmente, destaca los objetivos de promover la convivencia, el rendimiento escolar y la atención a la diversidad.
We endeavors for study and product development to be constant by drastic investment for fast generalization of LED, and reduces the cost that is an issue largest of a LED generalization, and will supply it to customers with reasonable prices.
This document provides an overview of fluorometry, including basic concepts, instrumentation, and applications. It discusses how fluorescence occurs when a molecule absorbs light at one wavelength and reemits light at a longer wavelength. Factors that affect fluorescence such as temperature, pH, and dissolved oxygen are also covered. The relationship between fluorescence intensity and concentration is explained. Additionally, the document defines fluorescence polarization and describes various types of quenching including self-quenching, chemical quenching, and collisional quenching.
This document discusses key concepts in photosynthesis including absorption spectra of chlorophyll, action spectra, energy transfer during photosynthesis via resonance transfer to antenna complexes located in chloroplasts or plasma membranes, the z-scheme of electron transfer between four protein complexes in the thylakoid membrane, carbon reactions, differences in C3 and C4 plant leaf anatomy, and the C4 carbon fixation cycle.
intoduction to lumiscence
introduction and principle of chemilumiscence
different types of lumiscence
detail of the electrochemilumiscence, working, principle, instrumentation, measurin.
application in medical field
difference between chemilumiscence and elecrochemiluminescence
This document contains lecture notes for a Physical Chemistry VIII course taught by Dr. Fateh Eltaboni at the University of Benghazi. The notes cover topics in photochemistry including characteristics of light, absorption of light, the Beer-Lambert law, photochemical reactions versus thermochemical reactions, quantum yield, and calculations related to photochemistry. Dr. Eltaboni provides examples and illustrations to explain key concepts in photochemistry.
1. Photochemistry involves using light as a chemical reagent to promote molecules to electronically excited states or as a chemical product when excited states return to the ground state.
2. Fluorescence occurs when a molecule in an excited singlet state returns to the ground state and emits light. It is a spin-allowed process that results in emission at a longer wavelength than the absorbed light.
3. The excitation and fluorescence emission spectra of a compound are often approximately mirror images of each other, though there are exceptions when the excited and ground states differ in geometry.
The document discusses how solvents and chromophores affect UV-visible spectroscopy. It states that the solvent exerts influence on the absorption spectrum, with the same drug showing different absorption maxima in different solvents. Common solvents used are water, methanol, ethanol, ether, and cyclohexane. The solvent should not absorb in the region studied and have minimum interaction with solute. Chromophores like conjugated systems, carbonyls, and metal complexes determine absorption. Factors like conjugation, auxochromes, and solvent polarity can shift absorption maxima.
In molecular spectroscopy, a Jablonski diagram is a diagram that illustrates the electronic states of a molecule and the transitions between them. The states are arranged vertically by energy and grouped horizontally by spin multiplicity.
This document discusses factors that affect fluorimetry and quenching. It lists several factors that can influence fluorescence, including the nature of molecules, substituents, concentration, adsorption, light, oxygen, pH, temperature, and viscosity. It also describes different types of quenching such as self-quenching, chemical quenching, static quenching, and collisional quenching. Chemical quenching can occur due to changes in pH, presence of oxygen, or heavy metals. Static quenching involves complex formation between the fluorophore and quencher. Collisional quenching occurs through interactions between an excited fluorophore and quencher molecule.
1. Fluorescence anisotropy measures the polarization of emitted light from fluorophores and can be used to study molecular interactions and rotational motions.
2. When fluorophores are excited with polarized light, their subsequent emission is depolarized by rotational diffusion. Larger molecules rotate more slowly, preserving more polarization.
3. Fluorescence anisotropy can be used to measure binding constants and kinetics by detecting changes in rotational diffusion upon molecular interactions like antibody-antigen binding. This provides information about molecular size, shape, and microenvironment.
This document discusses factors that affect fluorescence and phosphorescence. It defines fluorescence and phosphorescence as types of molecular luminescence that are excited by photon absorption. The main difference is that fluorescence involves no change in electron spin, while phosphorescence does involve a change. Several factors can influence emission, including molecular structure and rigidity, temperature, solvent properties, pH, dissolved oxygen, concentration, and the presence of heavy atoms. More rigid and planar structures favor fluorescence and phosphorescence. Higher temperatures, viscosities, and oxygen levels decrease emission, while appropriate solvent polarity and pH can increase it.
This document discusses luminescence spectroscopy techniques such as fluorescence and phosphorescence. It explains that molecules absorb energy which is then emitted at a higher wavelength, and that emission is proportional to concentration. It also describes the energy level diagram and competing processes that occur after absorption, such as internal conversion, intersystem crossing, vibrational relaxation, and fluorescence or phosphorescence emission. Factors that affect fluorescence such as conjugation, substituents, and structural rigidity are also summarized.
Photoluminescent properties of fullerene derivativeszenziyan
The document discusses photoluminescence properties of fullerene derivatives. It explains that fullerenes and their derivatives show strong absorption around 3.7 eV but weak luminescence at room temperature due to a forbidden electronic transition. However, their photoluminescence increases at low temperatures due to reduced thermal quenching. The document also describes how fullerenes can act as energy transfer acceptors or donors in composite materials, and provides examples of photoluminescent fullerene-doped polymers and inorganic materials.
This document discusses chemiluminescence reactions that emit light. It defines chemiluminescence as a light-emitting chemical reaction and distinguishes it from other types of luminescence. Examples of gas-phase and liquid-phase chemiluminescent reactions are provided, such as the reaction of nitric oxide with ozone that produces excited nitrogen dioxide and emits light. The document also explores the chemiluminescent reaction involved in glowsticks and the firefly luciferase reaction.
Ultraviolet and visible spectroscopy is a technique that uses light in the UV-visible spectral region. It can be used to analyze organic molecules and determine their structure. Key concepts covered include electronic transitions, the Beer-Lambert law, and how solvents and conjugation affect UV-Vis spectra. UV-Vis spectroscopy can distinguish between isomers and functional groups, quantify substances, and identify unknown compounds.
This document summarizes key concepts in plasma chemistry from Chapter 2 of the reference book, including:
1) Elementary plasma reactions are determined by micro-kinetic characteristics like cross-sections and reaction probabilities, as well as kinetic distribution functions.
2) Collisions can be elastic, inelastic, or superelastic depending on whether the total kinetic energy and internal energies change during the collision.
3) Ionization processes include direct electron impact ionization, stepwise ionization, ion-molecule collisions, photoionization, and surface ionization.
4) The Thomson formula describes direct electron impact ionization cross-sections at high energies, while the Frank-Condon principle applies to ionization
This document discusses instrumentation methods of fluorimetry. It describes the key components of a fluorimeter including light sources like mercury vapor lamps and xenon arc lamps, filters and monochromators to select wavelengths of light, sample cells to hold liquid samples, and detectors like photomultiplier tubes and photovoltaic cells. Common types of fluorimeters are single beam, double beam, and spectrofluorimeters. Applications include determination of inorganic substances, proteins, and drugs.
Chemiluminescence is the production of light from a chemical reaction. Two chemicals react to form an excited intermediate state that releases energy in the form of photons as it returns to a stable ground state. This light emission occurs without much heat release. Chemiluminescent reactions can be grouped into chemical reactions using synthetic compounds, bioluminescent reactions from living organisms like fireflies, and electrochemiluminescent reactions involving electrical current. Forensic scientists use the chemiluminescent reaction of luminol to detect traces of blood at crime scenes by spraying a mixture that causes a blue glow in the presence of iron from hemoglobin.
Fluorescence(Forster) Resonance Energy Transfersavvysahana
This document discusses using fluorescence resonance energy transfer (FRET) to study the assembly and rearrangements of SNARE proteins during exocytosis at neural synapses. It describes two schemes using FRET to label specific SNARE proteins with donor and acceptor fluorophores. Scheme 1 uses Cerulean and Citrine labels on VAMP and SNAP-25 to detect resting SNARE complexes and their dispersion after vesicle fusion. Scheme 2 uses Cerulean on Syntaxin and Citrine on VAMP to monitor the trans-cis conformational change in SNAREs. The study finds FRET signals indicating the dynamic rearrangement of pre-assembled SNARE complexes during different stages of the SNARE cycle.
Flurimetry type of flurescence & quenchingsimisheeja
This document discusses types of fluorescence and quenching. There are three main types of fluorescence based on the excitation source: chemiluminescence, electrochemiluminescence, and photoluminescence. Quenching decreases fluorescence intensity and occurs via four main mechanisms: self-quenching, chemical quenching, static quenching, and collisional quenching. Factors like concentration, pH, presence of oxygen, halides, heavy metals, and temperature can also influence fluorescence by inducing quenching effects.
El documento resume el proceso de admisión de alumnos en el IES Marqués de Lozoya para el curso 2011-2012, incluyendo las fechas clave para la reserva de plaza, cambio de centro y matrícula. También describe los recursos del instituto como la sección bilingüe de inglés, las nuevas tecnologías, los laboratorios y la biblioteca. Finalmente, destaca los objetivos de promover la convivencia, el rendimiento escolar y la atención a la diversidad.
We endeavors for study and product development to be constant by drastic investment for fast generalization of LED, and reduces the cost that is an issue largest of a LED generalization, and will supply it to customers with reasonable prices.
RIWC_PARA_A047 Autonomy from choice in community care. Creative rehabilitatio...Marco Muscroft
This document discusses supporting autonomy and aspirational thinking in young people with life-shortening conditions. It introduces CHAS, a hospice provider in Scotland serving babies, children, and young people up to age 21. The document explores the concepts of autonomy, free will, and aspirational thinking. It examines the unique needs of young people with life-shortening conditions and how case studies have brought about increased confidence. Future recommendations include evaluating programs, nurturing creativity, supporting dreams and planning, improving choice and inclusion, and fostering specialist resources and joint working.
RIWC_PARA_A109 Home living for SCI people in CanadaMarco Muscroft
This study explored perceptions of well-being at home among families that include a person with a disability. Semi-structured interviews were conducted separately with 31 people with spinal cord injuries and their family members. The kitchen was commonly identified as promoting well-being by allowing activities with others and independence with tasks. Other favorable spaces enabled skills development, learning, and privacy. Unfavorable spaces limited skills, tasks, and caused inconvenience. Both groups identified similar factors as influencing well-being, but experienced disabilities differently. The findings suggest home design should consider flexibility, accessibility, and central roles of tasks and social participation for well-being.
This document provides contact information for a graphic designer named MD DIN ISLAM, including Skype, Facebook, Twitter, and LinkedIn accounts as well as a Fiverr profile. It also notes that the designer is available for hire for graphic design projects and provides a link to their Fiverr page.
RIWC_PARA_A046 Autonomy with Life Limiting ConditionsMarco Muscroft
This study explored consumers' perspectives on self-determination, vocational rehabilitation engagement, and recovery. Through qualitative interviews, participants described how self-determination influenced their motivation and ability to engage with vocational rehabilitation services and progress in their recovery. Key findings included that developing trust and an individualized approach in the counselor relationship supported engagement. Having intrinsic motivation, social support, and a view of recovery as an ongoing process also helped drive vocational rehabilitation and recovery. The study provides insights to help improve services and support consumers' self-determination.
Este documento presenta la Ordenanza Municipal de Circulación de un municipio. Establece normas sobre el tráfico rodado, peatonal y de estacionamiento en vías públicas, incluyendo límites de velocidad, sentidos de circulación, prioridad de paso, zonas peatonales, carga y descarga, paradas de transporte público, y accesibilidad para personas con discapacidad. La ordenanza contiene 80 artículos organizados en 19 secciones que regulan todos los aspectos de la circulación vial en el municipio.
“NEM is more than just a cryptocurrency or a new altcoin; it is an entire platform built on revolutionary blockchain technology, reimagining from scratch the ideal blockchain. NEM does not only allow for standard peer-to-peer value transfer transactions, but instead does much more – store data, make transactions, prove identity, timestamp documents, and create arbitrary digital assets. Using secure cryptography, it can be used for a wide variety of applications across many industries, including the financial industry, government, logistics, and the medical industry. The NEM platform is a highly available system that any business, government, and/or an individual can make use of to shorten the design lifecycle and reduce their cost of operation.”
Lon Wong, Dragonfly Fintech CEO
Este documento presenta el reglamento interno del Consejo Local de Bienestar Social. Establece que el Consejo es un órgano consultivo del ayuntamiento encargado de promover la participación ciudadana en políticas de bienestar social. Describe su composición, que incluye representantes políticos, asociaciones ciudadanas y vecinos electos por sorteo. También define sus funciones, como asesorar al ayuntamiento sobre programas de bienestar social y promover la implicación de la ciudadanía en este ámbito.
Photochemistry is the branch of chemistry concerned with chemical reactions caused by light absorption. Photochemical reactions proceed differently than thermal reactions and can form thermodynamically disfavored products or overcome large activation barriers. When a molecule absorbs light, it is elevated to an excited state. The Grotthuss–Draper law states that light must be absorbed for a photochemical reaction to occur. Absorbed light can excite a molecule to different singlet or triplet states, which can then relax through radiationless or radiative processes like fluorescence or phosphorescence. Experimental factors like light sources, reactors, solvents, and wavelength selection influence photochemical reactions.
Photochemistry is the branch of chemistry concerned with chemical reactions caused by light absorption. Photochemical reactions proceed differently than thermal reactions and can form thermodynamically disfavored products or overcome large activation barriers. When a molecule absorbs light, it is elevated to an excited state. The Grotthuss–Draper law states that light must be absorbed for a photochemical reaction to occur. Absorbed light can excite a molecule to different singlet or triplet states, which can then relax through radiationless or radiative processes like fluorescence or phosphorescence. Experimental factors like light sources, reactors, solvents, and wavelength selection influence photochemical reactions.
The document discusses luminescence and phosphorescence spectroscopy. It defines luminescence as light emission from a substance when an electron returns to the ground state from an excited state. Phosphorescence is luminescence from a triplet excited state with a longer lifetime than fluorescence which occurs from a singlet state. The document describes various types of luminescence and provides details on instrumentation, sample preparation, and applications of phosphorescence spectroscopy in different fields such as pharmaceutical, clinical, environmental, and forensic analyses.
Photochemistry is the branch of chemistry concerned with chemical reactions caused by light. It involves the absorption, excitation, and emission of photons by molecules. Important examples include photosynthesis, vitamin D formation, and bioluminescence. Photochemical reactions require light absorption by a reactant and proceed through an excited state intermediate before products form.
This document provides an overview of spectrofluorimetry. It begins with an introduction that defines fluorescence and phosphorescence as types of photoluminescence that occur when electrons return to the ground state from an excited state. It then discusses the principle, theory, instrumentation, factors affecting fluorescence, and applications of spectrofluorimetry. The instrumentation section describes the main components, including a light source, excitation and emission monochromators, sample holder, detector, and readout device. Common factors that can affect fluorescence intensity are concentration, incident light intensity, quantum yield, absorption, pH, oxygen, temperature, viscosity, and scatter. Applications include chemical modification of compounds, identification of compounds based on excitation and emission spectra, and assays of vitamins
this presentation describes light phase of photosynthesis. it explains Evidences for two phases, Photosynthetic unit & Harvesting of light energy, Emerson effect &two photosystem, Hill reaction & Photolysis /photo-oxidation of water, Redox potential & mechanism of light reaction, Cyclic photophosphorylation, Non- cyclic photophosphorylation .
The document discusses photosynthesis and how it harvests sunlight using pigments like chlorophyll. It describes how:
1) Photosynthesis uses energy from sunlight to convert carbon dioxide and water into oxygen and carbohydrates like glucose, providing energy for plants and all life.
2) Light is absorbed by photosynthetic pigments in the chloroplast and its energy is transferred to the reaction center where the chemical reactions of photosynthesis take place.
3) Experiments by Emerson and Arnold showed that many chlorophyll molecules work together as a photosynthetic unit, with around 250-300 chlorophyll molecules transferring energy to each reaction center.
This document discusses fluorescence and phosphorescence techniques for chemical analysis. It defines fluorescence as emission of light that occurs immediately when excited by light, while phosphorescence involves continuous light emission even after excitation stops. Factors that determine whether a molecule is fluorescent include its quantum yield, structure, temperature, solvent, concentration, and pH. Instrumentation for fluorimetry includes light sources, filters, monochromators, and photomultiplier tubes. Applications include determination of inorganic and organic species. Fluorimetry offers higher sensitivity, specificity, and precision compared to absorption spectroscopy.
This document discusses phosphorescence spectroscopy and provides information about molecular luminescence, including fluorescence and phosphorescence. It describes the basic principles, including how molecules are excited to higher energy states and then emit light as they relax to lower energy states. Singlet and triplet states are defined, along with electronic and vibrational energy levels. Electron transitions like internal conversion, intersystem crossing, and vibrational relaxation are explained. Instrumentation for measuring phosphorescence is also summarized, including components like light sources, monochromators, sample cells, and detectors. Some applications of phosphorescence are mentioned, such as in television screens, pigments, and glow-in-the-dark toys.
Infrared spectroscopy is a technique that uses infrared light to analyze chemical bonding and structure. It works by measuring the frequencies at which molecules vibrate and absorb infrared radiation. Modern infrared instruments use a Fourier transform method with an interferometer to produce an infrared spectrum that acts as a molecular "fingerprint". Infrared spectroscopy is useful for identifying unknown materials, determining molecular structure of organic and inorganic compounds, and studying molecular interactions.
The document summarizes photosynthesis, including:
1) Photosynthesis uses light energy, water, carbon dioxide to produce glucose and oxygen through two phases - the light reactions and dark reactions.
2) The light reactions use light to produce ATP and NADPH using chlorophyll and a series of electron carriers in the thylakoid membranes.
3) The dark reactions use ATP and NADPH to fix carbon from carbon dioxide into glucose through the Calvin cycle in the chloroplast stroma.
This document discusses fluorometry and its application in analyzing cephalosporin antibiotics. It begins with defining types of luminescence including fluorescence and providing an overview of the principles of fluorometry. It then discusses structural factors that affect fluorescence and advantages of fluorometry such as high sensitivity. The document provides examples of using fluorometry to analyze specific cephalosporins like cefoxitin and cefuroxime. It also briefly discusses other methods for analyzing cephalosporins and concludes by stating fluorometry is well suited for trace analysis of pharmaceutical compounds.
The document discusses various devices used for biomolecular and cellular research, focusing on those based on interactions with electromagnetic radiation. It describes spectrophotometers that use absorption, emission, or fluorescence of light to measure biomolecule concentrations or study structure. Specific devices covered include UV/visible absorption spectrophotometers, infrared spectrophotometers, Raman spectrometers, and circular dichroism instruments. These tools allow analyzing properties like protein secondary structure, drug interactions at the molecular level, and transport processes.
Chloroplasts are organelles found in plant cells and other eukaryotic cells that are the site of photosynthesis. They contain chlorophyll and have a double membrane structure, with stacks of internal membranes called thylakoids that are the site of the light-dependent reactions of photosynthesis. During photosynthesis, chloroplasts capture energy from sunlight and use it to convert carbon dioxide and water into oxygen and energy-rich molecules like glucose through a two-stage process of light-dependent and light-independent reactions.
This document provides an overview of UV-visible spectroscopy. It discusses the history and development of UV-visible spectrometers. It explains that UV-visible spectroscopy involves measuring the absorption of UV or visible light by a sample. This can provide information about molecular structure through electronic transitions. The document also outlines the Beer-Lambert law and how it relates absorbance to concentration. It describes instrumentation components and electronic transitions involved. Applications like detection of impurities and structure elucidation are also mentioned.
1) The absorption of light by organic compounds involves the promotion of electrons from ground state to excited state molecular orbitals. Sigma electrons undergo σ-σ* transitions at shorter wavelengths while pi and non-bonding electrons undergo π-π* and n-π* transitions at longer wavelengths.
2) Chromophores are functional groups responsible for electronic transitions, imparting color. Auxochromes enhance absorption by chromophores through resonance. Conjugation and pH can shift absorption to longer wavelengths while dilution, solvents, and temperature can affect absorption spectra.
3) Spectrophotometry is widely used for quantitative analysis due to its sensitivity, selectivity, accuracy and ease. Both absorbing and non-absorbing
IR spectroscopy provides a spectrum that contains absorption bands that can determine the structure of organic compounds. It works by detecting the frequencies at which molecules vibrate and absorb infrared radiation. The most useful infrared region for analyzing organic compounds has wavelengths from 4000 to 400 cm-1. When infrared radiation is absorbed by a molecule, it causes bonds to stretch or bend based on their vibrational modes. For a vibration to be detected in the infrared spectrum, it must cause a change in the dipole moment of the molecule.
Spectrofluorimetry is a technique that measures fluorescence emitted from molecules. It involves exciting molecules with UV or visible light which causes electrons to transition to an excited state. The molecule then relaxes and emits light of a longer wavelength. Factors like concentration, quantum yield, path length, pH, temperature and presence of quenchers affect the intensity of fluorescence. Spectrofluorimeters are used to collect excitation and emission spectra of molecules to identify them.
The document summarizes the four main types of interactions that can occur between laser radiation and biological tissues: photochemical, photothermal, photoablative, and photomechanical. It provides details on the laser parameters and intensities required for each interaction and describes the resulting biological effects, such as chemical changes, heating, ablation of material, and cavitation. Photochemical interactions occur at low intensities and involve chemical reactions. Photothermal interactions produce heating effects. Photoablation removes layers of material at very high intensities. Photomechanical interactions generate shock waves and cavitation bubbles through plasma formation.
Plants have developed various protective mechanisms to cope with photoinhibition caused by excess light stress. These include dissipating excess energy through state transitions, the xanthophyll cycle, and cyclic electron flow. Damaged D1 proteins in PSII are rapidly replaced. The water-water cycle and photorespiration help reduce reactive oxygen species buildup. Together these mechanisms help prevent damage to the photosynthetic electron transport system during periods of high light stress.
Similar to The Role of Ultrafast Processes in Human Vision (20)
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.